Scrape wikipedia-science: 9793 new, 3573 updated, 13726 total (kb-cron)
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data/en.wikipedia.org/wiki/CNS_(chemical_weapon)-0.md
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data/en.wikipedia.org/wiki/CNS_(chemical_weapon)-0.md
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title: "CNS (chemical weapon)"
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source: "https://en.wikipedia.org/wiki/CNS_(chemical_weapon)"
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category: "reference"
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tags: "science, encyclopedia"
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CNS is a mixture of chloroacetophenone, chloropicrin and chloroform that is used as a chemical warfare agent. CNS has the lachrymatory effects of chloroacetophenone and choking effects of chloropicrin. It has a flypaper-like odor.
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CNS was used as a riot control agent, but it is no longer used.
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== References ==
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---
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title: "Carbon dioxide transmission rate"
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source: "https://en.wikipedia.org/wiki/Carbon_dioxide_transmission_rate"
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category: "reference"
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tags: "science, encyclopedia"
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date_saved: "2026-05-05T11:26:44.301378+00:00"
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Carbon dioxide transmission rate (COTR) is the measurement of the amount of carbon dioxide gas that passes through a substance over a given period. It is mostly carried out on non-porous materials, where the mode of transport is diffusion, but there are a growing number of applications where the transmission rate also depends on flow through apertures of some description.
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== See also ==
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Moisture vapor transmission rate
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Permeation
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Oxygen transmission rate
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Packaging
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== Further reading ==
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Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6
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Massey, L. K., "Permeability Properties of Plastics and Elastomers", 2003, Andrew Publishing, ISBN 978-1-884207-97-6
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=== Standards ===
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ASTM D1434 - Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting
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ASTM F1115 - Standard Test Method for Determining the Carbon Dioxide Loss of Beverage Containers
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ASTM F2476 - Test Method for the Determination of Carbon Dioxide Gas Transmission Rate (Co 2TR) Through Barrier Materials Using An Infrared Detector
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data/en.wikipedia.org/wiki/Carbonaceous-0.md
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data/en.wikipedia.org/wiki/Carbonaceous-0.md
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title: "Carbonaceous"
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source: "https://en.wikipedia.org/wiki/Carbonaceous"
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category: "reference"
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tags: "science, encyclopedia"
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date_saved: "2026-05-05T11:26:45.486671+00:00"
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Carbonaceous refers to something relating to, containing, or composed of carbon. It is a descriptor used for the attribute of any substance rich in carbon. Particularly, carbonaceous hydrocarbons are very unsaturated, high-molecular-weight hydrocarbons, having an elevated carbon:hydrogen ratio. The carbonaceous chondrites are meteorites that are rich in carbon.
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The word "carbonaceous" was first used in 1791.
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In geology, metamorphism of a carbonaceous geological material is expressed as a graphitisation process, referring to the graphite generated. Graphitisation may be accelerated or retarded in dependence on various metamorphic or lithological factors involved.
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== See also ==
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Carbonaceous chondrite
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Carbonaceous film
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Carbonaceous soil
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C-type (carbonaceous) asteroid
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Spheroidal carbonaceous particles (SCPs)
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== References ==
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data/en.wikipedia.org/wiki/Cell_casting-0.md
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data/en.wikipedia.org/wiki/Cell_casting-0.md
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title: "Cell casting"
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source: "https://en.wikipedia.org/wiki/Cell_casting"
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category: "reference"
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Cell casting is a method used for creating poly(methyl methacrylate) (PMMA) sheets. Liquid monomer is poured between two flat sheets of toughened glass sealed with a rubber gasket and heated for polymerization. Because the glass sheets may contain surface scratches or sag during the process, this traditional method has some disadvantages: among other problems, the PMMA sheets may contain variations in thickness and surface defects. For many applications it has since been replaced by other methods for making PMMA such as extrusion, which gives uniform surface features. However, for applications where strength is critical cell casting techniques are still employed in conjunction with stretching, which produces a stronger overall material.
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"Cell Casting - A process in which a casting liquid is poured between two plates, usually glass, that have a gasket between them to form a cell to contain the casting liquid; then the resin solidifies, usually through polymerization or crosslinking." - A. Brent Strong
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== References ==
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data/en.wikipedia.org/wiki/Chameleon_(molecular)-0.md
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data/en.wikipedia.org/wiki/Chameleon_(molecular)-0.md
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title: "Chameleon (molecular)"
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source: "https://en.wikipedia.org/wiki/Chameleon_(molecular)"
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category: "reference"
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In the field of molecular science, a chameleon molecule refers to a compound, often large and flexible, capable of dynamically altering its conformation and surface properties in response to changing environments. This unique ability, known as chameleonicity, allows such molecules to present polar surfaces in water to enhance solubility or to fold and hide these polar groups to become more cell membrane permeable in nonpolar settings. Chameleon molecules are especially significant in medicinal chemistry, where they enable the design of drugs that overcome traditional limitations in absorption and bioavailability by adapting their shape and polarity to traverse diverse biological barriers.
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Examples of molecules that display chameleonicity include cyclic peptides such as cyclosporine and PROTACs such as bavdegalutamide and vepdegestrant.
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== References ==
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data/en.wikipedia.org/wiki/Chapman_rearrangement-0.md
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data/en.wikipedia.org/wiki/Chapman_rearrangement-0.md
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---
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title: "Chapman rearrangement"
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source: "https://en.wikipedia.org/wiki/Chapman_rearrangement"
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category: "reference"
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The Chapman rearrangement is the thermal conversion of aryl N-arylbenzimidates to the corresponding amides, via intramolecular migration of an aryl group from oxygen to nitrogen. It is named after Arthur William Chapman, who first described it, and is conceptually similar to the Newman–Kwart rearrangement.
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== References ==
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data/en.wikipedia.org/wiki/Chemical_conditioning-0.md
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data/en.wikipedia.org/wiki/Chemical_conditioning-0.md
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---
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title: "Chemical conditioning"
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source: "https://en.wikipedia.org/wiki/Chemical_conditioning"
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category: "reference"
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date_saved: "2026-05-05T11:26:50.207369+00:00"
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In chemistry, conditioning is a process in which chemical reaction factors are stabilized or enhanced. Examples include increasing the quality of a material by using another material (a conditioner) or improving the ability of solids to capture and physically or chemically treat water. There are three main conditioning systems: heat, inorganic compounds and organic polymers.
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== References ==
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data/en.wikipedia.org/wiki/Chemical_intermediate-0.md
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data/en.wikipedia.org/wiki/Chemical_intermediate-0.md
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---
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title: "Chemical intermediate"
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source: "https://en.wikipedia.org/wiki/Chemical_intermediate"
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category: "reference"
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In the chemical industry, a chemical intermediate (collectively "intermediate chemicals") is the (stable) product of a chemical reaction process, valued as a reagent for subsequent industrial chemical processes, as distinguished from a product valuable to the end consumer. For example, ethanol has application as a solvent, a fuel, and in artificial liquors; but when it is sold to manufacture ethyl esters, it is a chemical intermediate.
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Some chemicals derive value entirely from their role as chemical intermediates. Cumene is made from benzene and propylene and used to make acetone and phenol in the cumene process. The cumene itself is of relatively little value in and of itself, and is typically only bought and sold by chemical companies. Likewise the United Nations Economic Commission for Europe has summarized adiponitrile as "an intermediate compound in the manufacture of Nylon". Chloroform and carbon tetrachloride have historical uses as (respectively) an anesthetic and a solvent, but now are primarily chemical intermediates for fluorocarbon production. Pure chemical intermediates constitute the majority of chemical products by type; in 1936, Williams Haynes estimated that they constituted 70% of all chemicals manufactured in the United States.
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== References ==
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data/en.wikipedia.org/wiki/Chemical_metallurgy-0.md
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data/en.wikipedia.org/wiki/Chemical_metallurgy-0.md
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---
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title: "Chemical metallurgy"
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source: "https://en.wikipedia.org/wiki/Chemical_metallurgy"
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category: "reference"
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Chemical metallurgy is the science of obtaining metals from their concentrates, semi products, recycled bodies and solutions, and of considering reactions of metals with an approach of disciplines belonging to chemistry. As such, it involves reactivity of metals and it is especially concerned with the reduction and oxidation, and the chemical performance of metals.
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Subjects of study in chemical metallurgy include the extraction of metals, thermodynamics, electrochemistry, and chemical degradation (corrosion).
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== See also ==
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Metallurgy
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Physical metallurgy
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Extractive metallurgy
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== References ==
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data/en.wikipedia.org/wiki/Chlorine_bomb-0.md
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data/en.wikipedia.org/wiki/Chlorine_bomb-0.md
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title: "Chlorine bomb"
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source: "https://en.wikipedia.org/wiki/Chlorine_bomb"
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category: "reference"
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date_saved: "2026-05-05T11:26:53.787495+00:00"
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A chlorine bomb is a small explosive device which uses the pressure of chemically produced chlorine gas or other chlorine-containing gases such as hydrogen chloride to produce an explosion. It is made with an airtight container part-filled with different types of chlorine tablet and other reagents. The reaction produces an expansive increase in pressure, eventually rupturing the container. Usually, such a device is not made on a large scale, often being manufactured from common household objects.
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Such a device is a more toxic and acidic alternative to a dry ice bomb, but likewise typically made by young people for amusement and recreational use rather than with any intent to harm. However, exposure to chlorinous gases and the reactive substances involved can cause respiratory problems from inhalation and also cause injury to other mucous membranes, similar to tear gas. Most injuries relating to these devices involve bruised hands, blinding and other eye injuries.
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Contrary to the belief of chemical laymen and some public security experts, chlorine is not generated by the reaction of hydrochloric acid with ammonia, but instead ammonium chloride is produced. Also chlorine is not formed by the reaction of chlorine bleach with ammonia. The reaction of bleach with ammonia forms monochloramine, nitrogen trichloride, and a number of other toxic and explosive products depending on the circumstances of the chemical reaction, but not pure chlorine.
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== See also ==
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Dry ice bomb
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Pipe bomb
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== References ==
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data/en.wikipedia.org/wiki/Chromic_acid_cell-0.md
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data/en.wikipedia.org/wiki/Chromic_acid_cell-0.md
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---
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title: "Chromic acid cell"
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source: "https://en.wikipedia.org/wiki/Chromic_acid_cell"
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category: "reference"
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date_saved: "2026-05-05T11:26:55.016935+00:00"
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---
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The chromic acid cell is a type of primary cell which uses chromic acid as a depolarizer. The chromic acid is usually made by acidifying (with sulfuric acid) a solution of potassium dichromate. The old name for potassium dichromate is potassium bichromate and the cell is often called a bichromate cell. This type of cell is now only of historical interest.
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== History ==
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== Construction ==
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The main elements of the cell are:
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Anode, zinc
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Electrolyte, dilute sulfuric acid
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Depolarizer, chromic acid
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Cathode, carbon
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The cell is made in two forms - the single-fluid type, attributed to Poggendorff and the two-fluid type, attributed to Fuller. In both cases, cell voltage is about 2 volts.
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=== Poggendorff cell ===
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The cell is set up in a long-necked glass bottle with a zinc plate located between two carbon plates. The electrolyte and depolarizer are then mixed. The mixture would dissolve the zinc plate even when the cell is not in use, so there is a mechanism for lifting the zinc plate out of the liquid and storing it in the neck of the bottle.
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=== Fuller cell ===
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The cell is set up in a glass, or glazed earthenware, pot. This contained the chromic acid solution, the carbon plate and a porous pot. Inside the porous pot is dilute sulfuric acid, the zinc rod, and a small quantity of mercury. The mercury formed an amalgam with the zinc and this reduced "local action", i.e. unwanted dissolution of the zinc when the cell is not in use.
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== See also ==
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List of battery types
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== References ==
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== External links ==
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Website: Telegraph batteries
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data/en.wikipedia.org/wiki/Coil_(chemistry)-0.md
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data/en.wikipedia.org/wiki/Coil_(chemistry)-0.md
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title: "Coil (chemistry)"
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source: "https://en.wikipedia.org/wiki/Coil_(chemistry)"
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category: "reference"
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A coil, in chemistry, is a tube, frequently in spiral form, used commonly to cool steam originating from a distillation and thus to condense it in liquid form. Usually it is of copper or another material that conducts heat easily. However copper is mostly used as a material, when a higher hardness is required it is combined with other elements to make an alloy such as brass or bronze.
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Coils are often used in chemical processes in batch reaction or mixing tank as internal source of heat transfer.
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== References ==
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data/en.wikipedia.org/wiki/Cold_water_extraction-0.md
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data/en.wikipedia.org/wiki/Cold_water_extraction-0.md
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---
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title: "Cold water extraction"
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source: "https://en.wikipedia.org/wiki/Cold_water_extraction"
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category: "reference"
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---
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Cold water extraction (also called CWE) is the process whereby a substance is extracted from a mixture via cold water. It is a type of fractional crystallization.
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The process generally involves taking a mixture of substances, dissolving them in warm water, and then rapidly cooling the mixture. The insoluble compounds precipitate out of the water, while the soluble ones stay dissolved. The solution can then be separated by filtration or decantation. This process works by exploiting the differences in solubility of different substances in a low temperature mixture.
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Opiates are much more soluble in cold water than acetaminophen. It is used to separate out opiate drugs that have been mixed with common non-opiate analgesics. When cold water extraction is used with codeine/paracetamol, hydrocodone/paracetamol and oxycodone/paracetamol medications, it is not effective at removing all of the paracetamol.
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== Items needed ==
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The cold water extraction process is fairly simple not only due to the simplicity of the method but also because the items needed are minimal and can all be found in a common household. The items used in the process are usually 2 drinking glasses (or any other container), a screen (used to filter) and an item capable of crushing the tablets (mortar and pestle for example). The recommended screen to use is a simple coffee filter due to its high effectiveness when compared to other screens such as a piece of cloth or folded napkin.
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== Legality ==
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Extraction of controlled substances from over-the-counter or prescription drug formulations may be illegal in some countries.
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== See also ==
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Codeine
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Hydrocodone
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Paracetamol
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Paracetamol toxicity
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== References ==
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---
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title: "Colloid-facilitated transport"
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source: "https://en.wikipedia.org/wiki/Colloid-facilitated_transport"
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---
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Colloid-facilitated transport designates a transport process by which colloidal particles serve as transport vector
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of diverse contaminants in the surface water (sea water, lakes, rivers, fresh water bodies) and in underground water circulating in fissured rocks
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(limestone, sandstone, granite, ...). The transport of colloidal particles in surface soils and in the ground can also occur, depending on the soil structure, soil compaction, and the particles size, but the importance of colloidal transport was only given sufficient attention during the 1980 years.
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Radionuclides, heavy metals, and organic pollutants, easily sorb onto colloids suspended in water and that can easily act as contaminant carrier.
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Various types of colloids are recognised: inorganic colloids (clay particles, silicates, iron oxy-hydroxides, ...), organic colloids (humic and fulvic substances). When heavy metals or radionuclides form their own pure colloids, the term "Eigencolloid" is used to designate pure phases, e.g., Tc(OH)4, Th(OH)4, U(OH)4, Am(OH)3. Colloids have been suspected for the long range transport of plutonium on the Nevada Nuclear Test Site. They have been the subject of detailed studies for many years. However, the mobility of inorganic colloids is very low in compacted bentonites and in deep clay formations
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because of the process of ultrafiltration occurring in dense clay membrane.
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The question is less clear for small organic colloids often mixed in porewater with truly dissolved organic molecules.
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== See also ==
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== References ==
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== External links ==
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Colloidal transport in porous media
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BELBar European project on the role of clay colloids in the transport of radionuclides for the deep geological disposal of radioactive waste
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=== Software programs for modeling colloid-facilitated transport ===
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The Geochemist's Workbench
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Hydrus
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data/en.wikipedia.org/wiki/Colloid_vibration_current-0.md
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---
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title: "Colloid vibration current"
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source: "https://en.wikipedia.org/wiki/Colloid_vibration_current"
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category: "reference"
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date_saved: "2026-05-05T11:26:59.724434+00:00"
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---
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Colloid vibration current is an electroacoustic phenomenon that arises when ultrasound propagates through a fluid that contains ions and either solid particles or emulsion droplets.
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The pressure gradient in an ultrasonic wave moves particles relative to the fluid. This motion disturbs the double layer that exists at the particle-fluid interface. The picture illustrates the mechanism of this distortion. Practically all particles in fluids carry a surface charge. This surface charge is screened with an equally charged diffuse layer; this structure is called the double layer. Ions of the diffuse layer are located in the fluid and can move with the fluid. Fluid motion relative to the particle drags these diffuse ions in the direction of one or the other of the particle's poles. The picture shows ions dragged towards the left hand pole. As a result of this drag, there is an excess of negative ions in the vicinity of the left hand pole and an excess of positive surface charge at the right hand pole. As a result of this charge excess, particles gain a dipole moment. These dipole moments generate an electric field that in turn generates measurable electric current. This phenomenon is widely used for measuring zeta potential in concentrated colloids.
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== See also ==
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Electric sonic amplitude
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Electroacoustic phenomena
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Interface and colloid science
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Zeta potential
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== References ==
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||||
31
data/en.wikipedia.org/wiki/Colour_retention_agent-0.md
Normal file
31
data/en.wikipedia.org/wiki/Colour_retention_agent-0.md
Normal file
@ -0,0 +1,31 @@
|
||||
---
|
||||
title: "Colour retention agent"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Colour_retention_agent"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:02.147865+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Colour retention agents are food additives that are added to food to prevent the colour from changing. Many of them work by absorbing or binding to oxygen before it can damage food (antioxidants). For example, ascorbic acid (vitamin C) is often added to brightly coloured fruits such as peaches during canning.
|
||||
|
||||
|
||||
== List of colour retention agent ==
|
||||
|
||||
|
||||
== See also ==
|
||||
Artificial sweetener
|
||||
Acidity regulator
|
||||
Codex Alimentarius
|
||||
E number
|
||||
Food colouring
|
||||
Food safety
|
||||
List of antioxidants in food
|
||||
List of food additives
|
||||
List of food additives, Codex Alimentarius
|
||||
List of fruits
|
||||
List of vegetables
|
||||
|
||||
|
||||
== References ==
|
||||
25
data/en.wikipedia.org/wiki/Compatibility_(chemical)-0.md
Normal file
25
data/en.wikipedia.org/wiki/Compatibility_(chemical)-0.md
Normal file
@ -0,0 +1,25 @@
|
||||
---
|
||||
title: "Compatibility (chemical)"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Compatibility_(chemical)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:03.362255+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Chemical compatibility is a rough measure of how stable a substance is when mixed with another substance. If two substances can mix together and not undergo a chemical reaction, they are considered compatible. Incompatible chemicals react with each other, and can cause corrosion, mechanical weakening, evolution of gas, fire, or other undesirable interactions.
|
||||
Chemical compatibility is important when choosing materials for chemical storage or reactions, so that the vessel and other apparatus will not be damaged by its contents. For purposes of chemical storage, chemicals that are incompatible should not be stored together, so that any leak will not cause an even more dangerous situation from chemical reactions. In addition, chemical compatibility refers to the container material being acceptable to store the chemical or for a tool or object that comes in contact with a chemical to not degrade. For example, when stirring a chemical, the stirrer must be stable in the chemical that is being stirred.
|
||||
Many companies publish chemical resistance charts. and databases to help chemical users use appropriate materials for handling chemicals. Such charts are particularly important for polymers as they are often not compatible with common chemical reagents; this may even depend on how the polymers have been processed. For example, 3-D printing polymer tools used for chemical experiments must be chosen to ensure chemical compatibility with care.
|
||||
Chemical compatibility is also important when choosing among different chemicals that have similar purposes. For example, bleach and ammonia, both commonly used as cleaners, can undergo a dangerous chemical reaction when combined with each other, producing poisonous fumes. Even though each of them has a similar use, care must be taken not to allow these chemicals to mix.
|
||||
|
||||
|
||||
== See also ==
|
||||
chemically inert
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Chemical compatibility database
|
||||
@ -0,0 +1,19 @@
|
||||
---
|
||||
title: "Concise International Chemical Assessment Document"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Concise_International_Chemical_Assessment_Document"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:04.492864+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Concise International Chemical Assessment Documents (CICADs) are published by the World Health Organization within the framework of the International Programme on Chemical Safety (IPCS). They describe the toxicological properties of chemical compounds.
|
||||
CICADs are prepared in draft form by one or two experts from national bodies such as the US Centers for Disease Control and Prevention, and then peer reviewed by an international group of experts. They do not constitute the official policy of any of the bodies which contribute to their publication.
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
"IPCS INCHEM - Concise International Chemical Assessment Documents (CICADs)". Archived from the original on 2005-12-31. Retrieved 2006-01-08. Official site
|
||||
20
data/en.wikipedia.org/wiki/Condosity-0.md
Normal file
20
data/en.wikipedia.org/wiki/Condosity-0.md
Normal file
@ -0,0 +1,20 @@
|
||||
---
|
||||
title: "Condosity"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Condosity"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:05.691893+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Condosity is a comparative measurement of electrical conductivity of a solution.
|
||||
The condosity of any given solution is defined as the molar concentration of a sodium chloride (NaCl) solution that has the same specific electrical conductance as the solution under test.
|
||||
By way of example, for a 2 Molar potassium chloride (KCl) solution, the condosity would be expected to be somewhat greater than 2.0. This is because potassium is a better conductor than sodium.
|
||||
|
||||
|
||||
== Applications ==
|
||||
The measurement is sometimes used in biological systems to provide an assessment of the properties of bodily or cellular liquids, or the properties of solutes in the physical environment. When measuring the properties of bodily fluids such as urine, condosity is expressed in units of millimoles per litre (mM/L).
|
||||
|
||||
|
||||
== References ==
|
||||
34
data/en.wikipedia.org/wiki/Controlled_lab_reactor-0.md
Normal file
34
data/en.wikipedia.org/wiki/Controlled_lab_reactor-0.md
Normal file
@ -0,0 +1,34 @@
|
||||
---
|
||||
title: "Controlled lab reactor"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Controlled_lab_reactor"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:06.900023+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, a Controlled Lab Reactor or CLR is any reaction system where there is an element of automated control. Generally these devices refers to a jacketed glass vessel where a circulating chiller unit pumps a thermal control fluid through the jacket to accurately control the temperature of the vessel contents. Additional to this, it is common to have a series of sensors (temperature, pH, pressure) measuring and recording parameters about the reactor contents. It is additionally possible to control pumps to act on the reactor.
|
||||
|
||||
|
||||
== Historical background ==
|
||||
The first controlled lab reactors were derived from the control systems used in chemical plants. These were generally dedicated to specific tasks as reprogramming was difficult. These first systems were often home built and used hardware that was adapted rather than designed for the task
|
||||
|
||||
|
||||
== Current systems ==
|
||||
Modern CLR systems take a wide range of forms with the ability to work on a range of different volume reactors (and indeed reactor styles). Data is usually transmitted back to a PC to be recorded (and indeed complex recipe based control is usually performed here too) though other systems may use off-line data logging.
|
||||
|
||||
|
||||
== Embedded sensors ==
|
||||
In the most sophisticated systems that exist, analytical instruments such as raman spectrometers and FTIR probes can also be integrated with the reactor. These more sophisticated systems also allow the closed loop control of the reactor as a result of taking readings from the sensors and analytical instruments concerned.
|
||||
|
||||
|
||||
== Reaction calorimeters ==
|
||||
Most reaction calorimeters can be used as controlled lab reactors (indeed some calorimeters are based on CLR's).
|
||||
|
||||
|
||||
== See also ==
|
||||
Reaction Calorimeter
|
||||
|
||||
|
||||
== References ==
|
||||
113
data/en.wikipedia.org/wiki/Cooling_capacity-0.md
Normal file
113
data/en.wikipedia.org/wiki/Cooling_capacity-0.md
Normal file
@ -0,0 +1,113 @@
|
||||
---
|
||||
title: "Cooling capacity"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Cooling_capacity"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:08.074833+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Cooling capacity is the measure of a cooling system's ability to remove heat. It is equivalent to the heat supplied to the evaporator/boiler part of the refrigeration cycle and may be called the "rate of refrigeration" or "refrigeration capacity". As the target temperature of the refrigerator approaches ambient temperature, without exceeding it, the refrigeration capacity increases thus increasing the refrigerator's COP. The SI unit is watt (W). Another unit common in non-metric regions or sectors is the ton of refrigeration, which describes the amount of water at freezing temperature that can be frozen in 24 hours, equivalent to 3.5 kW or 12,000 BTU/h.
|
||||
|
||||
|
||||
== Formula ==
|
||||
The basic SI units equation for deriving cooling capacity is of the form:
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Q
|
||||
˙
|
||||
|
||||
|
||||
|
||||
=
|
||||
|
||||
|
||||
|
||||
m
|
||||
˙
|
||||
|
||||
|
||||
|
||||
|
||||
C
|
||||
|
||||
p
|
||||
|
||||
|
||||
Δ
|
||||
T
|
||||
|
||||
|
||||
{\displaystyle {\dot {Q}}={\dot {m}}C_{p}\Delta T}
|
||||
|
||||
|
||||
Where
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Q
|
||||
˙
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\dot {Q}}}
|
||||
|
||||
is the cooling capacity [kW]
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
m
|
||||
˙
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\dot {m}}}
|
||||
|
||||
is the mass rate [kg/s]
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
C
|
||||
|
||||
p
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle C_{p}}
|
||||
|
||||
is the specific heat capacity [kJ/kg K]
|
||||
|
||||
|
||||
|
||||
|
||||
Δ
|
||||
T
|
||||
|
||||
|
||||
{\displaystyle \Delta T}
|
||||
|
||||
is the temperature change [K]
|
||||
|
||||
|
||||
== References ==
|
||||
18
data/en.wikipedia.org/wiki/Craig_tube-0.md
Normal file
18
data/en.wikipedia.org/wiki/Craig_tube-0.md
Normal file
@ -0,0 +1,18 @@
|
||||
---
|
||||
title: "Craig tube"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Craig_tube"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:09.236277+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Craig tube is an item of apparatus used in small-scale (up to about 100 mg) preparative and analytical chemistry, particularly for recrystallisation. It was invented by Lyman C. Craig and Otto W. Post.
|
||||
A Craig tube consists of two parts. The first is a stout-walled test tube with a working volume of about 1-5 ml (say, 7-8 cm in length and 1-1.5 cm in diameter). There is a constriction towards the open end of the tube. The second is a loosely-fitting generally-cylindrical stopper, possibly with a teardrop-shaped head, of glass or of another inert material such as PTFE, which seats on the constriction.
|
||||
Recrystallisation is carried out in the usual manner, by dissolving the solid to be purified in a solvent and causing crystals of the solid to form. The stopper can be used to protect the solution from atmospheric contamination. The crystals are separated from the mother liquor by placing the tube and stopper – inverted – in a centrifuge tube, followed by centrifugation. The stopper allows the mother liquor to pass into the centrifuge tube but retains the crystals, which can subsequently be recrystallised again or collected.
|
||||
The apparatus has the advantages that the crystallised product is relatively dry, is free from contamination by fibres from filter paper, and can be recovered more efficiently than from a sinter funnel.
|
||||
Craig tubes can be made by competent glassblowers, and are also available commercially.
|
||||
|
||||
|
||||
== References ==
|
||||
24
data/en.wikipedia.org/wiki/Cresolene-0.md
Normal file
24
data/en.wikipedia.org/wiki/Cresolene-0.md
Normal file
@ -0,0 +1,24 @@
|
||||
---
|
||||
title: "Cresolene"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Cresolene"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:10.461543+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Cresolene is a dark liquid with a pungent smell made from coal tar used in the 19th and early 20th century as a disinfectant and to treat various ailments such as colds and measles. Most well known of all cresolene products was the Vapo-Cresolene lamp, used to heat the substance so that the fumes could be inhaled; these were produced between 1879 and 1957.
|
||||
|
||||
|
||||
== See also ==
|
||||
Cresol
|
||||
Resin
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Self Disinfecting Surface Coating
|
||||
Cresolene Advert From The Good Old Days
|
||||
24
data/en.wikipedia.org/wiki/DGH-0.md
Normal file
24
data/en.wikipedia.org/wiki/DGH-0.md
Normal file
@ -0,0 +1,24 @@
|
||||
---
|
||||
title: "DGH"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/DGH"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:17.667182+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Degrees of general hardness (dGH or °GH) is a unit of water hardness, specifically of general hardness. General hardness is a measure of the concentration of divalent metal ions such as calcium (Ca2+) and magnesium (Mg2+) per volume of water. Specifically, 1 dGH is defined as 10 milligrams (mg) of calcium oxide (CaO) per litre of water. Since CaO has a molar mass of 56.08 g/mol, 1 dGH is equivalent to 0.17832 mmol per litre of elemental calcium and/or magnesium ions.
|
||||
In water testing hardness is often measured in parts per million (ppm), where one part per million is defined as one milligram of calcium carbonate (CaCO3) per litre of water. Consequently, 1 dGH corresponds to 10 ppm CaO but 17.848 ppm CaCO3 which has a molar mass of 100.09 g/mol.
|
||||
|
||||
|
||||
== See also ==
|
||||
|
||||
Carbonate hardness
|
||||
Hard water
|
||||
dKH
|
||||
|
||||
|
||||
== References ==
|
||||
Frank, Larry (1997-12-16). "Water Hardness". The Krib. Archived from the original on 2018-10-24. Retrieved 2011-11-04.
|
||||
Krüger, Bernd (2022). "Wasserhärte [de] / Dureté de l'eau [fr]" [Hardness of water]. Cactus2000 (in German, English, and French). Archived from the original on 2021-02-22. Retrieved 2009-01-23.
|
||||
25
data/en.wikipedia.org/wiki/DKH-0.md
Normal file
25
data/en.wikipedia.org/wiki/DKH-0.md
Normal file
@ -0,0 +1,25 @@
|
||||
---
|
||||
title: "DKH"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/DKH"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:20.091864+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Degrees of German carbonate hardness (°dKH or °KH; the dKH is from the German deutsche Karbonathärte) is a unit of water hardness, specifically for temporary or carbonate hardness. Carbonate hardness is a measure of the concentration of carbonates such as calcium carbonate (CaCO3) and magnesium carbonate (MgCO3) per volume of water. As a unit 1 dKH is the same as 1 °dH which is equal to approximately 0.1786 mmol/L or 10.02 milligrams (mg) of calcium oxide per litre of water, i.e. 17.86 ppm.
|
||||
The measurements of total hardness (German Gesamthärte (GH)) and carbonate hardness (German Karbonathärte (KH)) are sometimes stated with units dKH and dGH to differentiate them from one another, although in both cases the unit they are measured in is German degrees (°dH).
|
||||
|
||||
|
||||
== See also ==
|
||||
|
||||
Carbonate hardness
|
||||
Hard water
|
||||
dGH
|
||||
|
||||
|
||||
== External links ==
|
||||
Water Hardness definitions
|
||||
Convertor for Hardness of water
|
||||
What is Temporary Hardness
|
||||
21
data/en.wikipedia.org/wiki/Dalapon-sodium-0.md
Normal file
21
data/en.wikipedia.org/wiki/Dalapon-sodium-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "Dalapon-sodium"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dalapon-sodium"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:11.766774+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Dalapon-sodium is the sodium salt of dalapon, a selective herbicide, used in Australia. Sometimes it is also simply called "dalapon" or "dalapon (present as the sodium salt)", see dalapon for information on dalapon generally.
|
||||
Dalapon-sodium is an organochloride, the conjugate base of 2,2-dichloropropanoic acid, and usually supplied as a water-soluble powder. Concentrated solutions hydrolyze over time.
|
||||
Dalapon-sodium's mode of action is unknown, which puts it in Group Z / Group 0 under the HRAC classification.
|
||||
In soil, it has a half life tested at 30 days.
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Dalapon-sodium in the Pesticide Properties DataBase (PPDB)
|
||||
99
data/en.wikipedia.org/wiki/Dasymeter-0.md
Normal file
99
data/en.wikipedia.org/wiki/Dasymeter-0.md
Normal file
@ -0,0 +1,99 @@
|
||||
---
|
||||
title: "Dasymeter"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dasymeter"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:12.941546+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A dasymeter is a device that acts as a densimeter used to measure the density of gases. It consists of a thin sphere made of glass, ideally with an average density close to that of the gas to be investigated. This sphere is immersed in the gas and weighed. The dasymeter was initially intended to be a device to demonstrate the buoyant effect of gases like air.
|
||||
|
||||
|
||||
== Principle ==
|
||||
|
||||
The Principle of Archimedes permits to derive a formula which does not rely on any volumetric information: a sample, the big sphere in the adjacent images, of known mass-density is weighed in vacuum and then immersed into the gas and weighed again.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
density of sphere
|
||||
density of gas
|
||||
|
||||
|
||||
=
|
||||
|
||||
|
||||
weight of sphere
|
||||
|
||||
|
||||
weight of sphere
|
||||
|
||||
−
|
||||
|
||||
weight of immersed sphere
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\frac {\text{density of sphere}}{\text{density of gas}}}={\frac {\text{weight of sphere}}{{\text{weight of sphere}}-{\text{weight of immersed sphere}}}}\,}
|
||||
|
||||
|
||||
(The above formula was taken from the article buoyancy and still has to be solved for the density of the gas.)
|
||||
From the known mass density of the sample (sphere) and its two weight-values, the mass-density of the gas can be calculated as:
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
density of gas
|
||||
|
||||
=
|
||||
|
||||
|
||||
|
||||
|
||||
weight of sphere
|
||||
|
||||
−
|
||||
|
||||
weight of immersed sphere
|
||||
|
||||
|
||||
weight of sphere
|
||||
|
||||
|
||||
×
|
||||
|
||||
density of sphere
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\text{density of gas}}={\frac {{\text{weight of sphere}}-{\text{weight of immersed sphere}}}{\text{weight of sphere}}}\times {\text{density of sphere}}}
|
||||
|
||||
|
||||
|
||||
== History ==
|
||||
The dasymeter was invented in 1650 by Otto von Guericke.
|
||||
Archimedes used a pair of scales which he immersed into water to demonstrate the buoyant effect of water. A dasymeter can be seen as a variant of that pair of scales, only immersed into gas rather than liquid.
|
||||
|
||||
|
||||
== See also ==
|
||||
|
||||
Calculation of buoyancy flows and flows inside buildings
|
||||
Hydrostatic weighing
|
||||
Laboratory glassware
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
|
||||
Volume Conversion
|
||||
39
data/en.wikipedia.org/wiki/Delay_composition-0.md
Normal file
39
data/en.wikipedia.org/wiki/Delay_composition-0.md
Normal file
@ -0,0 +1,39 @@
|
||||
---
|
||||
title: "Delay composition"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Delay_composition"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:14.089348+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Delay composition, also called delay charge or delay train, is a pyrotechnic composition, a sort of pyrotechnic initiator, a mixture of oxidizer and fuel that burns in a slow, constant rate that should not be significantly dependent on temperature and pressure. Delay compositions are used to introduce a delay into the firing train, e.g. to properly sequence firing of fireworks, to delay firing of ejection charges in e.g. model rockets, or to introduce a few seconds of time between triggering a hand grenade and its explosion. Typical delay times range between several milliseconds and several seconds.
|
||||
A popular delay charge is a tube of pressed black powder. The mechanical assembly prevents the outright detonation of the charge.
|
||||
While delay compositions are principally similar to other fuel-oxidizer compositions, larger grain sizes and less aggressively reacting chemicals are used. Many of the compositions generate little or no gas during burning. Typical materials used are:
|
||||
|
||||
Fuels: silicon, boron, manganese, tungsten, antimony, antimony trisulfide, zirconium, zirconium–nickel alloy, zinc, magnesium, etc.
|
||||
Oxidizers: lead dioxide, iron oxides, barium chromate, lead chromate, tin(IV) oxide, bismuth(III) oxide, barium sulfate (for high-temperature compositions), potassium perchlorate (usually used in small amount together with other oxidizers), etc.
|
||||
Additives to cool down the flame and slow down the reaction can be employed; inert materials or coolants like titanium dioxide, ground glass, chalk, sodium bicarbonate, etc. are common.
|
||||
The burn rates are dependent on: [1]
|
||||
|
||||
nature of fuel - fuels that release more heat burn faster
|
||||
nature of oxidizer - oxidizers that require less heat to decompose burn faster
|
||||
the composition ratio - stoichiometric mixtures burn the fastest, also slight excess of metallic fuel also increases burn rate, probably due to heat transfer
|
||||
particle sizes - smaller particles burn faster, but too small particles may lead to incomplete or interrupted burn due to too narrow heating zone
|
||||
mechanical assembly and housing - charge diameter and thermal conductivity of housing influence lateral heat losses
|
||||
ambient temperature - ideally this dependence is very low but extremely low or extremely high temperatures may have influence
|
||||
Examples of some compositions are: [2]
|
||||
|
||||
black powder with addition of inert material, e.g. chalk or sodium bicarbonate
|
||||
lead(II) oxide with silicon, burning at 1.5–2 cm/s
|
||||
red lead with silicon, burning at intermediate rate
|
||||
lead(IV) oxide with silicon, burning at 5–6 cm/s
|
||||
potassium permanganate with antimony, very slow
|
||||
Manganese Delay Composition: manganese with lead chromate and barium chromate (lead chromate is the principal oxidizer, barium chromate acts as burning rate modifier, the more of it the slower the reaction) [3] Archived 2008-06-02 at the Wayback Machine
|
||||
Tungsten Delay Composition: tungsten with barium chromate and potassium perchlorate [4]
|
||||
Zirconium Nickel Alloy Delay Composition: zirconium-nickel alloy with barium chromate and potassium perchlorate.
|
||||
boron with barium chromate [5]
|
||||
|
||||
|
||||
== References ==
|
||||
22
data/en.wikipedia.org/wiki/Dextran_sulphate_sodium-0.md
Normal file
22
data/en.wikipedia.org/wiki/Dextran_sulphate_sodium-0.md
Normal file
@ -0,0 +1,22 @@
|
||||
---
|
||||
title: "Dextran sulphate sodium"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dextran_sulphate_sodium"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:15.304851+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Dextran sulphate sodium (DSS), or dextran sodium sulphate (or any of the former with "sulfate") is a synthetic sulphated polysaccharide with anticoagulant activity used in immunological research to induce colitis. Dextran polymer molecules with a molecular weight of 36–50 kDa are frequently used to this end.
|
||||
|
||||
|
||||
== DSS-induced colitis ==
|
||||
DSS-induced colitis is the most widely used mouse model of colitis, such as is seen in inflammatory bowel disease (IBD). Acute colitis can be achieved within 7-10 days, while chronic colitis can be induced by 3-5 cycles of the former with 1-2 weeks in between each cycle.
|
||||
|
||||
|
||||
=== Mechanism ===
|
||||
DSS is thought to induce colitis by causing injury to the colonic epithelium. The sulphate groups make the dextran molecules highly negatively charged and induce erosions in the epithelium, eventually compromising its integrity and increasing its permeability, while DSS's anticoagulant action promotes intestinal bleeding.
|
||||
|
||||
|
||||
== References ==
|
||||
33
data/en.wikipedia.org/wiki/Dextrose_equivalent-0.md
Normal file
33
data/en.wikipedia.org/wiki/Dextrose_equivalent-0.md
Normal file
@ -0,0 +1,33 @@
|
||||
---
|
||||
title: "Dextrose equivalent"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dextrose_equivalent"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:16.495469+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Dextrose equivalent (DE) is a measure of the amount of reducing sugars present in a sugar product, expressed as a percentage on a dry basis relative to dextrose. The dextrose equivalent gives an indication of the average degree of polymerisation (DP) for starch sugars. As a rule of thumb, DE × DP = 120.
|
||||
In all glucose polymers, from the native starch to glucose syrup, the molecular chain ends with a reducing sugar, containing a free aldehyde in its linear form. As the starch is hydrolysed, the molecules become shorter and more reducing sugars are present. Therefore, the dextrose equivalent describes the degree of conversion of starch to dextrose. The standard method of determining the dextrose equivalent is the Lane-Eynon titration, based on the reduction of copper(II) sulfate in an alkaline tartrate solution, an application of Fehling's test.
|
||||
Examples:
|
||||
|
||||
A maltodextrin with a DE of 10 would have 10% of the reducing power of dextrose which has a DE of 100.
|
||||
Maltose, a disaccharide made of two glucose (dextrose) molecules, has a DE of 52, correcting for the water loss in molecular weight when the two molecules are combined. Glucose (dextrose) has a molecular mass of 180, while water has a molecular mass of 18. For each 2 glucose monomers binding, a water molecule is removed.
|
||||
Therefore, the molecular mass of a glucose polymer can be calculated by using the formula (180*n - 18*(n-1)) with n the DP (degree of polymerisation) of the glucose polymer. The DE can be calculated as 100*(180 / Molecular mass( glucose polymer)). In this example the DE is calculated as 100*(180/(180*2-18*1)) = 52.
|
||||
|
||||
Sucrose actually has a DE of zero even though it is a disaccharide, because both reducing groups of the monosaccharides that make it are connected, so there are no remaining reducing groups.
|
||||
Because different reducing sugars (e.g. fructose and glucose) have different sweetness, it is incorrect to assume that there is any direct relationship between dextrose equivalent and sweetness.
|
||||
|
||||
|
||||
== Uses ==
|
||||
Dextrose equivalent is used to understand how different sugar products will affect:
|
||||
|
||||
Crystallization prevention (higher starch content reduces ability of sugars to crystallize, therefore improving shelf stability)
|
||||
Viscosity (higher starch content sugars are more viscous)
|
||||
Water activity (small monosaccharides tend to be more hygroscopic)
|
||||
Sweetness (starches are less sweet)
|
||||
Caramelization (through the maillard reaction)
|
||||
|
||||
|
||||
== References ==
|
||||
20
data/en.wikipedia.org/wiki/Dianion-0.md
Normal file
20
data/en.wikipedia.org/wiki/Dianion-0.md
Normal file
@ -0,0 +1,20 @@
|
||||
---
|
||||
title: "Dianion"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dianion"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:18.894721+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A dianion is an anion with a net charge of −2. While there exist many stable molecular dianions, such as BeF42− and MgF42−, thus far no stable atomic dianion has been found: Electron shielding and other quantum mechanical effects tend to make the addition of another electron to an atomic anion unstable.
|
||||
The most heavily studied atomic dianion is H2−, usually as a short-lived resonance between an electron and a hydrogen ion. In 1976, its half-life was experimentally measured to be 23 ± 4 nanoseconds.
|
||||
In the field of physiology, molecular dianions play an important roles, such as the monohydrogen phosphate ([HPO4]2−), present at a concentration of around 1 mM in the blood and in cells, where it plays a role in pH buffering.
|
||||
|
||||
|
||||
== See also ==
|
||||
Dication
|
||||
|
||||
|
||||
== References ==
|
||||
@ -0,0 +1,26 @@
|
||||
---
|
||||
title: "Dunathan stereoelectronic hypothesis"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dunathan_stereoelectronic_hypothesis"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:22.529847+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Dunathan stereoelectronic hypothesis is a concept in chemistry to explain the stereospecific cleavage of bonds using pyridoxal phosphate. This occurs because stereoelectronic effects controls the actions of the enzyme.
|
||||
|
||||
|
||||
== History ==
|
||||
Before the correlation between fold type and reaction correlation of proteins were understood, Harmon C. Dunathan, a chemist at Haverford College proposed that the bond that is cleaved using pyridoxal is perpendicular to the system. Though an important concept in bioorganic chemistry, it is now known that enzyme conformations play a critical role in the final chemical reaction.
|
||||
|
||||
|
||||
== Mode of action ==
|
||||
The transition state is stabilized by the extended pi bond network (formation of anion). Furthermore hyperconjugation caused by the extended network draws electrons from the bond to be cleaved, thus weakening the chemical bond and making it labile The sigma bond that is parallel to the pi bond network will break. The bond that has the highest chance of being cleaved is one with the largest HOMO-LUMO overlap. This effect might be effected by electrostatic effects within the enzyme.
|
||||
|
||||
|
||||
== Applications ==
|
||||
This was seen in transferase and future interests lie in decarboxylation in various catalytic cycles.
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dynamical_Theory_of_Crystal_Lattices"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:57:50.959273+00:00"
|
||||
date_saved: "2026-05-05T11:27:23.835657+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
21
data/en.wikipedia.org/wiki/Dühring's_rule-0.md
Normal file
21
data/en.wikipedia.org/wiki/Dühring's_rule-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "Dühring's rule"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Dühring's_rule"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:21.336881+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Dühring's rule is a scientific rule developed by Eugen Dühring which states that a linear relationship exists between the temperatures at which two solutions exert the same vapour pressure. The rule is often used to compare a pure liquid and a solution at a given concentration.
|
||||
Dühring's plot is a graphical representation of such a relationship, typically with the pure liquid's boiling point along the x-axis and the mixture's boiling point along the y-axis; each line of the graph represents a constant concentration.
|
||||
|
||||
|
||||
== See also ==
|
||||
Solubility
|
||||
Evaporator
|
||||
Raoult's law
|
||||
|
||||
|
||||
== References ==
|
||||
19
data/en.wikipedia.org/wiki/Ebulliometer-0.md
Normal file
19
data/en.wikipedia.org/wiki/Ebulliometer-0.md
Normal file
@ -0,0 +1,19 @@
|
||||
---
|
||||
title: "Ebulliometer"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Ebulliometer"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:25.001691+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In physics, an ebulliometer (from Latin ēbullīre 'to boil') is an instrument designed to accurately measure the boiling point of liquids by measuring the temperature of the vapor–liquid equilibrium either isobarically (at constant pressure) or isothermally (at constant temperature).
|
||||
The primary components in a Świętosławski ebulliometer, which operates isobarically, are the boiler, the Cottrell pumps, the thermowell, and the condenser. Such an ebulliometer can be used for extremely accurate measurements of boiling temperature, molecular weights, mutual solubilities, and solvent purities by using a resistance thermometer (RTD) to measure the near-equilibrium conditions of the thermowell.
|
||||
The ebulliometer is frequently used for measuring the alcohol content of dry wines. See also Sweetness of wine and Oechsle scale.
|
||||
|
||||
|
||||
== References ==
|
||||
"Ebulliometer". Monash Scientific.
|
||||
"Ebulliometer explained". winegrowers. Archived from the original on 2009-09-23. Retrieved 2009-05-07.
|
||||
Sandler, S. I. (1999). Chemical and Engineering Thermodynamics (3rd ed.). New York: J. Wiley and Sons. pp. 504–507. ISBN 0-471-18210-9.
|
||||
14
data/en.wikipedia.org/wiki/Emulsion_test-0.md
Normal file
14
data/en.wikipedia.org/wiki/Emulsion_test-0.md
Normal file
@ -0,0 +1,14 @@
|
||||
---
|
||||
title: "Emulsion test"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Emulsion_test"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:26.187233+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
The emulsion test is a simple method used in educational settings to determine the presence of lipids using wet chemistry. The procedure is for the sample to be suspended in ethanol, allowing lipids present to dissolve (lipids are soluble in alcohols). The liquid (alcohol with dissolved fat) is then decanted into water. Since lipids do not dissolve in water while ethanol does, when the ethanol is diluted, it falls out of the solution to give a cloudy white emulsion. This method is not typically used in research or industry.
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Encyclopedia_of_Analytical_Chemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:57:55.981998+00:00"
|
||||
date_saved: "2026-05-05T11:27:27.457043+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Encyclopedia_of_Reagents_for_Organic_Synthesis"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:57:57.267104+00:00"
|
||||
date_saved: "2026-05-05T11:27:28.721198+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
28
data/en.wikipedia.org/wiki/Epoxy_putty-0.md
Normal file
28
data/en.wikipedia.org/wiki/Epoxy_putty-0.md
Normal file
@ -0,0 +1,28 @@
|
||||
---
|
||||
title: "Epoxy putty"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Epoxy_putty"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:29.911040+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Epoxy putty refers to a group of room-temperature-hardening substances used as space-filling adhesives. Exact compositions vary according to manufacturer and application.
|
||||
Epoxy putty, once hardened, is a thermosetting polymer, so it will retain its shape rather than melting when heated. It was first developed for commercial use in the 1940s.
|
||||
Epoxy putties are stored until used as two components of clay-like consistency. Kneading the two components into each other creates an exothermic chemical reaction that activates the substance for use by catalysing an epoxide polymerisation reaction. Unlike many other types of glues, an epoxy adhesive can fill gaps, and even be moulded into a structural part. Some makers claim in advertising that one can drill and tap their cured products and that they quickly cure "hard as steel" (as measured by Shore rating), though they are much weaker than steel in tensile strength and shear strength.
|
||||
Epoxy putty is commonly used to repair basic damage to the blades of wind turbines. It is also often used by miniature modelers, and sculptors. Modelers use it to join disparate parts into a whole with the joins covered by moulded putty, often shaped into protrusions or textures to match their surroundings. The most common variety of epoxy putty used in modelling has its component clays coloured yellow and blue, respectively, and the mixed, hardened end product is green. This has given rise to the colloquial name green stuff for epoxy putty.
|
||||
|
||||
|
||||
== See also ==
|
||||
Putty
|
||||
Milliput
|
||||
Pratley Putty
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Megastick Epoxy Putty
|
||||
How to Glue Styrofoam to Various Surfaces Archived 2022-11-29 at the Wayback Machine
|
||||
@ -0,0 +1,14 @@
|
||||
---
|
||||
title: "Estimated maximum possible concentration"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Estimated_maximum_possible_concentration"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:31.130163+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Estimated maximum possible concentration (EMPC) is a term used in dioxin concentration determination for a concentration between limit of quantification and limit of detection.
|
||||
|
||||
|
||||
== References ==
|
||||
19
data/en.wikipedia.org/wiki/Ethachlor-0.md
Normal file
19
data/en.wikipedia.org/wiki/Ethachlor-0.md
Normal file
@ -0,0 +1,19 @@
|
||||
---
|
||||
title: "Ethachlor"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Ethachlor"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:32.342604+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Ethachlor is a chloroacetamide herbicide used in China.
|
||||
Ethachlor's HRAC group is Group K (Australia), Group K3 (Global) and Group 15 (numeric).
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Ethachlor on BCPC
|
||||
18
data/en.wikipedia.org/wiki/Fernbach_flask-0.md
Normal file
18
data/en.wikipedia.org/wiki/Fernbach_flask-0.md
Normal file
@ -0,0 +1,18 @@
|
||||
---
|
||||
title: "Fernbach flask"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Fernbach_flask"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:33.597650+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Fernbach flask is a type of flask suited for large volume cell culture where the culture requires a large surface area to volume ratio. Typically, they are baffled on the bottom in order to maximize oxygen transfer to the culture medium when shaken. The flask was named after French biologist Auguste Fernbach (1860-1939). A common volume of Fernbach flasks is 2.8 L, although only less than half would typically be used to allow for the best liquid-to-air surface area for appropriate gas exchange. Fernbach flasks are about 8" in diameter, and 9" high.
|
||||
|
||||
|
||||
== See also ==
|
||||
Erlenmeyer flask
|
||||
|
||||
|
||||
== References ==
|
||||
28
data/en.wikipedia.org/wiki/Film_laboratory-0.md
Normal file
28
data/en.wikipedia.org/wiki/Film_laboratory-0.md
Normal file
@ -0,0 +1,28 @@
|
||||
---
|
||||
title: "Film laboratory"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Film_laboratory"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:34.783853+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A film laboratory is a commercial service enterprise and technical facility for the film industry where specialists develop, print, and conform film material for classical film production and distribution which is based on film material, such as negative and positive, black and white and color, on different film formats: 65-70mm, 35mm, 28mm, 16mm, 9.5mm, 8mm. The film laboratory managers can charge by the footage or by time used while in lab.
|
||||
|
||||
|
||||
== History ==
|
||||
In the early days of motion pictures, films were processed by winding on flat racks and then dipping in tanks of solution. As films became longer, such methods proved to be too cumbersome.
|
||||
|
||||
|
||||
== Processes ==
|
||||
Exposed motion picture film will be processed according to exact chemical prescriptions at measured temperature as well as over measured time.
|
||||
After processing there is an original, the camera or picture original, in most cases a negative. From it a first sample is exposed on a motion-picture film printer. Again after processing there is a positive ready for inspection by the production representatives, usually by projection in the dark just like one sees a movie in a theatre.
|
||||
The film lab thus needs various apparatus from developing equipment and machines, over measuring tools, cutting, editing devices, and printers to different sorts of viewing machinery including classic projectors. Besides there are sensitometers, densitometers, analysers, and array of chemical laboratory items that will help maintaining a level of repeatability of operations. Auxiliary material is also encountered within a film laboratory, for example leader film, plain plastic, to keep a developing machine threaded up.
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== Other Resources ==
|
||||
FIAF List of Photochemical Film Labs From Around the World
|
||||
17
data/en.wikipedia.org/wiki/Fleaker-0.md
Normal file
17
data/en.wikipedia.org/wiki/Fleaker-0.md
Normal file
@ -0,0 +1,17 @@
|
||||
---
|
||||
title: "Fleaker"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Fleaker"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:36.043770+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Fleaker is a brand of container for liquids used in the laboratory. It can be described as a hybrid design, combining features of the Griffin beaker and the Erlenmeyer flask.
|
||||
Like a beaker, the bottom is flat, with the sides meeting the bottom at a 90-degree angle. The sides are vertical for most of the height; near the top, the sides curve in to form a neck with a widely flared rim. The wide rim makes it easier to pour from or filter into; the narrow neck reduces loss of the contents due to splashing and serves as a grip for handling and pouring.
|
||||
Fleaker containers have a plastic lid with a built-in rubber stopper. When on the Fleaker, the lid covers the narrow neck. Fleaker containers work as well as other glassware for liquids and solutions, but are inappropriate for slurries, precipitates, and recrystallizations (since the narrow neck makes it difficult to remove solids completely from a Fleaker).
|
||||
The Fleaker was invented by Roy Eddleman, founder of Spectrum Medical Industries (now Spectrum Laboratories). Fleaker is a registered trademark of Spectrum Laboratories, licensed to Corning.
|
||||
|
||||
|
||||
== References ==
|
||||
16
data/en.wikipedia.org/wiki/Formula_unit-0.md
Normal file
16
data/en.wikipedia.org/wiki/Formula_unit-0.md
Normal file
@ -0,0 +1,16 @@
|
||||
---
|
||||
title: "Formula unit"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Formula_unit"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:37.244251+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, a formula unit is the smallest unit of a non-molecular substance, such as an ionic compound, covalent network solid, or metal. It can also refer to the chemical formula for that unit. Those structures do not consist of discrete molecules, and so for them, the term formula unit is used. In contrast, the terms molecule or molecular formula are applied to molecules. The formula unit is used as an independent entity for stoichiometric calculations. Examples of formula units, include ionic compounds such as NaCl and K2O and covalent networks such as SiO2 and C (as diamond or graphite).
|
||||
In most cases the formula representing a formula unit will also be an empirical formula, such as calcium carbonate (CaCO3) or sodium chloride (NaCl), but it is not always the case. For example, the ionic compounds potassium persulfate (K2S2O8), mercury(I) nitrate Hg2(NO3)2, and sodium peroxide Na2O2, have empirical formulas of KSO4, HgNO3, and NaO, respectively, being presented in the simplest whole number ratios.
|
||||
In mineralogy, as minerals are almost exclusively either ionic or network solids, the formula unit is used. The number of formula units (Z) and the dimensions of the crystallographic axes are used in defining the unit cell.
|
||||
|
||||
|
||||
== References ==
|
||||
45
data/en.wikipedia.org/wiki/Fractionation-0.md
Normal file
45
data/en.wikipedia.org/wiki/Fractionation-0.md
Normal file
@ -0,0 +1,45 @@
|
||||
---
|
||||
title: "Fractionation"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Fractionation"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:38.417263+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Fractionation is a separation process in which a certain quantity of a mixture (of gasses, solids, liquids, enzymes, or isotopes, or a suspension) is divided during a phase transition, into a number of smaller quantities (fractions) in which the composition varies according to a gradient. Fractions are collected based on differences in a specific property of the individual components. A common trait in fractionations is the need to find an optimum between the amount of fractions collected and the desired purity in each fraction. Fractionation makes it possible to isolate more than two components in a mixture in a single run. This property sets it apart from other separation techniques.
|
||||
Fractionation is widely employed in many branches of science and technology. Mixtures of liquids and gasses are separated by fractional distillation by difference in boiling point. Fractionation of components also takes place in column chromatography by a difference in affinity between stationary phase and the mobile phase. In fractional crystallization and fractional freezing, chemical substances are fractionated based on difference in solubility at a given temperature. In cell fractionation, cell components are separated by difference in mass.
|
||||
|
||||
|
||||
== Of natural samples ==
|
||||
|
||||
|
||||
=== Bioassay-guided fractionation ===
|
||||
A typical protocol to isolate a pure chemical agent from natural origin is step-by-step separation of extracted components based on differences in their bioassay-guided fractionation physicochemical properties, and assessing the biological activity, followed by next round of separation and assaying. Typically, such work is initiated after a given crude extract is deemed "active" in a particular in vitro assay.
|
||||
|
||||
|
||||
=== Blood fractionation ===
|
||||
|
||||
The process of blood fractionation involves separation of blood into its main components. Blood fractionation refers generally to the process of separation using a centrifuge (centrifugation), after which three major blood components can be visualized: plasma, buffy coat and erythrocytes (blood cells). These separated components can be analyzed and often further separated.
|
||||
|
||||
|
||||
=== Of food ===
|
||||
Fractionation is also used for culinary purposes, as coconut oil, palm oil, and palm kernel oil are fractionated to produce oils of different viscosities, that may be used for different purposes. These oils typically use fractional crystallization (separation by solubility at temperatures) for the separation process instead of distillation. Mango oil is an oil fraction obtained during the processing of mango butter.
|
||||
Milk can also be fractionated to recover the milk protein concentrate or the milk basic proteins fraction.
|
||||
|
||||
|
||||
== Isotope fractionation ==
|
||||
|
||||
|
||||
== See also ==
|
||||
Copurification
|
||||
List of purification methods in chemistry
|
||||
Transposition cipher#Fractionation
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== Further reading ==
|
||||
Houghton, Peter J.; Raman, Amala (1998). Laboratory Handbook for the Fractionation of Natural Extracts. doi:10.1007/978-1-4615-5809-5. ISBN 978-1-4613-7662-0.
|
||||
21
data/en.wikipedia.org/wiki/Free_element-0.md
Normal file
21
data/en.wikipedia.org/wiki/Free_element-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "Free element"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Free_element"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:39.590554+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, a free element is a chemical element that is not combined with or chemically bonded to other elements. These may either be chemically inert, or may form bonds with atoms of the same element.
|
||||
Metals, non-metals, and noble gases can all be found as free elements. Noble gases such as helium and argon are found in the monoatomic state due to the low reactivity of these atoms. Similarly, noble metals such as gold and platinum are also found in the pure state naturally. Non-metals are rarely found as free elements in the solid state — carbon is a notable exception, as it may be found as diamond and graphite. However, they commonly exist as gases, examples of which include molecular oxygen, ozone, and nitrogen, which together make up approximately 99% of the atmosphere. Because of their reactivity, the halogens do not naturally occur in the free elemental state, but they are both widespread and abundant in the form of their halide ions. They are, however, stable in their diatomic forms.
|
||||
|
||||
|
||||
== See also ==
|
||||
Native metal
|
||||
Noble metal
|
||||
Native element mineral
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Fundamentals_of_Biochemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:11.648724+00:00"
|
||||
date_saved: "2026-05-05T11:27:40.859291+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Gel_point_(petroleum)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T10:52:35.109317+00:00"
|
||||
date_saved: "2026-05-05T11:27:42.147986+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
21
data/en.wikipedia.org/wiki/Glowing_pickle_demonstration-0.md
Normal file
21
data/en.wikipedia.org/wiki/Glowing_pickle_demonstration-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "Glowing pickle demonstration"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Glowing_pickle_demonstration"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:43.400849+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Applying electric current across a pickle causes it to glow. A moist pickle contains salt as a result of the pickling process, which allows it to conduct electricity. Ions of sodium and other substances within the pickle emit light as a result of atomic electron transitions, although it is not clear why the luminescence occurs at one end of the pickle.
|
||||
The glowing pickle is used to demonstrate ionic conduction and atomic emission in chemistry classes, and also as a demonstration in lighting classes.
|
||||
The first known fully documented demonstration was in a 1989 report from Digital Equipment Corporation. Although this was published as a full technical note and written up as a scientific paper, the publication date, April Fools' Day of that year, gives some indication as to the light-hearted nature of the document.
|
||||
|
||||
|
||||
== See also ==
|
||||
Lemon battery – Simple battery made with a lemon for educational purposes
|
||||
Food chemistry – Study of chemical processes in food
|
||||
|
||||
|
||||
== References ==
|
||||
14
data/en.wikipedia.org/wiki/Goldberg_drum-0.md
Normal file
14
data/en.wikipedia.org/wiki/Goldberg_drum-0.md
Normal file
@ -0,0 +1,14 @@
|
||||
---
|
||||
title: "Goldberg drum"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Goldberg_drum"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:44.662671+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Goldberg drum is a laboratory equipment used in the studies of aerosols. It was described by Leonard J. Goldberg from the Naval Biological Laboratory, School of Public Health, University of California, Berkeley, in 1958. It is used to contain airborne aerosols and particles.
|
||||
|
||||
|
||||
== References ==
|
||||
17
data/en.wikipedia.org/wiki/Grindometer-0.md
Normal file
17
data/en.wikipedia.org/wiki/Grindometer-0.md
Normal file
@ -0,0 +1,17 @@
|
||||
---
|
||||
title: "Grindometer"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Grindometer"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:45.838051+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A grindometer is a device used to measure the particle size of suspensions, typically inks such as those used in printing, or paints. It consists of a steel block with a channel of varying depth machined into it, starting at a convenient depth for the type of suspension to be measured, and becoming shallower until it ends flush with the block's surface. The depth of the groove is marked off on a graduated scale next to it. The suspension to be tested is poured into the deep end of the groove, and scraped towards the shallow end with a flat metal scraper. At the point where the depth of the groove equals the largest particles in the suspension, irregularities (for example pinholes in an ink sample) will become visible.
|
||||
The advantages of this method are that it uses a small sample and gives a very quick indication of the high end of the particle size distribution, allowing production processes to be followed in real time.
|
||||
The following standards are relevant on conjunction with the use of grindometers: ASTM D 1210, ASTM D 1316, JIS K 5600-2-5, ISO 1524, EN ISO 1524, BS 3900-C6
|
||||
|
||||
|
||||
== References ==
|
||||
Gunter Buxbaum and Gerhard Pfaff (2005). Industrial Inorganic Pigments. Wiley-VCH. p. 44. ISBN 3-527-30363-4.
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Handbook_of_Electrochemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:23.597944+00:00"
|
||||
date_saved: "2026-05-05T11:27:47.062417+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Handbook_of_Porphyrin_Science"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:24.811567+00:00"
|
||||
date_saved: "2026-05-05T11:27:48.284804+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
22
data/en.wikipedia.org/wiki/Heated_bath-0.md
Normal file
22
data/en.wikipedia.org/wiki/Heated_bath-0.md
Normal file
@ -0,0 +1,22 @@
|
||||
---
|
||||
title: "Heated bath"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Heated_bath"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:49.476308+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A heated bath is used in the laboratory to allow a chemical reaction to occur at an elevated temperature. Heated baths are a type of thermal reservoir and equilibrium system that is able to add heat evenly to a system without changing the temperature of the fluid being used. Heated baths are often used as steps in larger experimental systems including both distillation and incubation. Reactions undergone in a heated bath are typically endothermic due to the continuous supply of heat as opposed to an exothermic reaction.
|
||||
In contrast to traditional Bunsen burners, heated baths use liquids to transfer heat to the reaction vessel. This is achieved using a high-boiling point liquid inside a thermally conducting bath (usually made of metal). The influence heat added by heated baths exponentially increases the overall reaction rate of a chemical reaction. Water and silicone oil are the most commonly used fluids. A water bath is used for temperatures up to 100 °C. An oil bath is employed for temperatures above 100 °C.
|
||||
The heated bath is heated on an electric hot plate, or with a Bunsen burner. The reaction vessel (Florence flask, Erlenmeyer flask, or beaker) is immersed in the heated bath. Heated baths are often used to heat flammable substances as a cautionary measure with handling. A thermometer is usually kept in the fluid to monitor the temperature. It is important not to raise the temperature of the used fluid too high as overheating of the reactants can cause unwanted bonds to break alongside risking denaturation in biochemical processes.
|
||||
|
||||
|
||||
== See also ==
|
||||
Bain-marie, a.k.a. double boiler
|
||||
Heat bath
|
||||
Sand bath
|
||||
|
||||
|
||||
== References ==
|
||||
15
data/en.wikipedia.org/wiki/Heatproof_mat-0.md
Normal file
15
data/en.wikipedia.org/wiki/Heatproof_mat-0.md
Normal file
@ -0,0 +1,15 @@
|
||||
---
|
||||
title: "Heatproof mat"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Heatproof_mat"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:50.672193+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A heatproof mat is a piece of apparatus commonly used in tabletop lab experiments that involve moderate temperatures (for example, when a Bunsen burner is being used) to prevent damage to a work surface. They may also be used for domestic equipment, such as hot plates, hair stylers, hair straighteners or other hot objects.
|
||||
Traditionally, such mats were made of asbestos. Fiberglass, calcium silicate or other substitutes are now used because of the toxicity of asbestos fibres.
|
||||
|
||||
|
||||
== References ==
|
||||
42
data/en.wikipedia.org/wiki/Heavy_liquid-0.md
Normal file
42
data/en.wikipedia.org/wiki/Heavy_liquid-0.md
Normal file
@ -0,0 +1,42 @@
|
||||
---
|
||||
title: "Heavy liquid"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Heavy_liquid"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:51.856108+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A heavy liquid is a solution or liquid chemical substance with a high density and a relatively low viscosity. Heavy liquids are often used for determination of density in mineralogy, for density gradient centrifugation and for separating mixtures.
|
||||
|
||||
|
||||
== Uses ==
|
||||
Common applications of heavy liquids include:
|
||||
|
||||
Density gradient centrifugation
|
||||
Separating mixtures and sink/swim analysis
|
||||
Flotation process
|
||||
Determination of density
|
||||
|
||||
|
||||
== Toxicity ==
|
||||
The classical heavy liquids like 1,1,2,2-tetrabromoethane (Muthmanns solution), potassium tetraiodomercurate(II) (Thoulets solution), bromoform or diiodomethane which are used in mineralogy are very toxic. These toxic chemicals are avoided today in consideration of the fact that there are alternative water based, non-toxic heavy liquids like sodium polytungstate solutions. With this relatively new heavy liquid densities up to 3.1 g·cm−3 can be adjusted . Adding parts of pulverulent tungsten carbide increases the density to 4.6 g·cm−3.
|
||||
|
||||
|
||||
== List of common heavy liquids with density > 2.0 g·cm−3 ==
|
||||
|
||||
Mercury is the heaviest liquid at room temperature. But the heaviest liquid irrespective of temperature is liquid osmium (a rare metal) at its melting point (3033°C/5491.4°F), with a density of 22.59 g·cm−3, 1.65 times as heavy as mercury.
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== Literature ==
|
||||
Schnitzer W, Zur Problematik der Schwermineralanalyse am Beispiel triassischer Sedimentgesteine, in International Journal of Earth Sciences, 72/1983, S.67–75, ISSN 1437-3254 (Print) 1437-3262 (Online)
|
||||
Boenigk, Schwermineralanalyse, S.6–15, Stuttgart: Enke, 1983.
|
||||
Ney, Gesteinsaufbereitung im Labor, S.92–113, Stuttgart: Enke, 1986.
|
||||
|
||||
|
||||
== External links ==
|
||||
General information about non-toxic heavy liquids
|
||||
49
data/en.wikipedia.org/wiki/Herbicide_safener-0.md
Normal file
49
data/en.wikipedia.org/wiki/Herbicide_safener-0.md
Normal file
@ -0,0 +1,49 @@
|
||||
---
|
||||
title: "Herbicide safener"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Herbicide_safener"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:53.035417+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Herbicide safeners are organic compounds used to enhance the effectiveness of herbicides, to make them "safer". They minimize the effect of the herbicide on crop plants, thereby improving selectivity between crop plants vs. weed species being targeted by the herbicide. One way that they function is by enhancing the expression of protective enzymes in the crop plant. These protective enzymes might include cytochrome P450.
|
||||
Herbicide safeners can be used to pretreat crop seeds prior to planting, or they can be sprayed on plants as a mixture with the herbicide.
|
||||
|
||||
|
||||
== Inventory ==
|
||||
|
||||
After the discovery of the safener properties of naphthalic anhydride, additional safeners were reported. They are associated with particular crops, such as benoxacor for maize and flurazole for sorghum.
|
||||
Approximately 20 safeners were in use in 2023. The inventory:
|
||||
|
||||
benoxacor
|
||||
BPCMS
|
||||
cloquintocet
|
||||
cyometrinil
|
||||
cyprosulfamide
|
||||
dichlormid
|
||||
dicyclonon
|
||||
dietholate
|
||||
fenchlorazole
|
||||
fenclorim
|
||||
flurazole
|
||||
fluxofenim
|
||||
furilazole
|
||||
isoxadifen
|
||||
jiecaowan
|
||||
jiecaoxi
|
||||
mefenpyr
|
||||
mephenate
|
||||
metcamifen
|
||||
naphthalic anhydride
|
||||
oxabetrinil
|
||||
These safeners have been classified according to structural motifs.
|
||||
|
||||
|
||||
== Further reading ==
|
||||
Review: Davies, Joanna; Caseley, John C. (1999). "Herbicide safeners: A review". Pesticide Science. 55 (11): 1043–1058. doi:10.1002/(SICI)1096-9063(199911)55:11<1043::AID-PS60>3.0.CO;2-L.
|
||||
Early pioneering report: Hoffmann, Otto L. (1953). "Inhibition of Auxin Effects by 2,4,6-Trichlorophenoxyacetic acid". Plant Physiology. 28 (4): 622–628. doi:10.1104/pp.28.4.622. PMC 540425. PMID 16654579.
|
||||
|
||||
|
||||
== References ==
|
||||
15
data/en.wikipedia.org/wiki/Heterofullerene-0.md
Normal file
15
data/en.wikipedia.org/wiki/Heterofullerene-0.md
Normal file
@ -0,0 +1,15 @@
|
||||
---
|
||||
title: "Heterofullerene"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Heterofullerene"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:54.213359+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Heterofullerenes are classes of fullerenes, at least one carbon atom is replaced by another element. Based on spectroscopy, substitutions have been reported with boron (borafullerenes), nitrogen (azafullerenes), oxygen (oxafullerenes), arsenic (arsafullerenes), germanium (germafullerenes), phosphorus (phosphafullerenes), silicon (silafullerenes), iron (ferrafullerenes), copper (cuprafullerenes), nickel (nickelafullerenes), rhodium (rhodafullerenes) and iridium (iridafullerenes).
|
||||
Reports on isolated heterofullerenes are limited to those based on nitrogen and oxygen.
|
||||
|
||||
|
||||
== References ==
|
||||
20
data/en.wikipedia.org/wiki/Heteronuclear_molecule-0.md
Normal file
20
data/en.wikipedia.org/wiki/Heteronuclear_molecule-0.md
Normal file
@ -0,0 +1,20 @@
|
||||
---
|
||||
title: "Heteronuclear molecule"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Heteronuclear_molecule"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:55.445271+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A heteronuclear molecule is a molecule composed of atoms of more than one chemical element. For example, a molecule of water (H2O) is heteronuclear because it has atoms of two different elements, hydrogen (H) and oxygen (O).
|
||||
Similarly, a heteronuclear ion is an ion that contains atoms of more than one chemical element. For example, the carbonate ion (CO2−3) is heteronuclear because it has atoms of carbon (C) and oxygen (O). The lightest heteronuclear ion is the helium hydride ion (HeH+). This is in contrast to a homonuclear ion, which contains all the same kind of atom, such as the dihydrogen cation, or atomic ions that only contain one atom such as the hydrogen anion (H−).
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== See also ==
|
||||
Homonuclear molecule
|
||||
Chemical compound
|
||||
35
data/en.wikipedia.org/wiki/Hexanitrogen-0.md
Normal file
35
data/en.wikipedia.org/wiki/Hexanitrogen-0.md
Normal file
@ -0,0 +1,35 @@
|
||||
---
|
||||
title: "Hexanitrogen"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Hexanitrogen"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:56.617296+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Hexanitrogen (diazide, hexaaza-1,2,4,5-tetraene) is an allotrope of nitrogen with the formula N6. The six nitrogen atoms are all covalently bonded in a single molecule: two azide units linked to each other. Its stability and structure were theorized in 2016 and its synthesis was reported in 2025. It is stable at cryogenic temperatures. The higher symmetry analogue, the benzene-like cyclic hexazine, has remained only theoretically hypothesized.
|
||||
Its synthesis has been regarded as highly significant, as higher allotropes of nitrogen have potential application as propellants, explosives or energy storage.
|
||||
|
||||
|
||||
== Synthesis ==
|
||||
It is synthesized by the reaction of silver azide (AgN3) with chlorine or bromine gas under reduced pressure at room temperature via chlorine azide or bromine azide as the intermediate. The product is collected by matrix isolation in solid argon (10 K) or by condensation on a liquid nitrogen cooled surface (77 K).
|
||||
|
||||
|
||||
== Structure ==
|
||||
All six atoms form a single chain, resembling two azide (N3) units linked together.
|
||||
|
||||
Computational analysis predicts that the bond lengths in the molecule vary significantly, indicating a complex electronic distribution, and a trans geometry in the central part of the structure. The terminal double bonds (N1=N2 and N5=N6) are about 1.138 Å. The adjacent double bonds (N2=N3 and N4=N5) are slightly longer, about 1.251 Å, and the central single bond (N3–N4) is the longest, about 1.460 Å. Each azide-like unit is approximately linear, with bond angles of about 172.5° at N2 and N5, and distinctly bent geometry of about 107° at N3 and N4.
|
||||
|
||||
|
||||
== See also ==
|
||||
Dinitrogen
|
||||
Trinitrogen
|
||||
Tetranitrogen
|
||||
Hexazine
|
||||
Octaazacubane
|
||||
Black nitrogen
|
||||
Other allotropes of nitrogen
|
||||
|
||||
|
||||
== References ==
|
||||
21
data/en.wikipedia.org/wiki/High-temperature_oxidation-0.md
Normal file
21
data/en.wikipedia.org/wiki/High-temperature_oxidation-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "High-temperature oxidation"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/High-temperature_oxidation"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:57.843693+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
High-temperature oxidation refers to a scale-forming oxidation process involving a metallic object and atmospheric oxygen that produces corrosion at elevated temperatures.
|
||||
High-temperature oxidation is a kind of High-temperature corrosion. Other kinds of high-temperature corrosion include high-temperature sulfidation and carbonization. High temperature oxidation and other corrosion types are commonly modelled using the Deal-Grove model to account for diffusion and reaction processes.
|
||||
|
||||
|
||||
== Mechanism of oxidation ==
|
||||
High temperature oxidation is generally occurs via the following chemical reaction between oxygen (O2) and a metal M:
|
||||
nM + 1/2kO2 = MnOk
|
||||
According to Wagner's theory of oxidation, oxidation rate is controlled by partial ionic and electronic conductivities of oxides and their dependence on the chemical potential of the metal or oxygen in the oxide.
|
||||
|
||||
|
||||
== References ==
|
||||
24
data/en.wikipedia.org/wiki/Holtfreter's_solution-0.md
Normal file
24
data/en.wikipedia.org/wiki/Holtfreter's_solution-0.md
Normal file
@ -0,0 +1,24 @@
|
||||
---
|
||||
title: "Holtfreter's solution"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Holtfreter's_solution"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:27:59.055556+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Holtfreter's solution (Holtfreter's medium) is a balanced salt solution that was developed by the developmental biologist Johannes Holtfreter for studying amphibian embryos and to reduce bacterial infections. As a specialised aqueous solution, it finds use in aquaria to prevent infections for early stage amphibians, where it is typically mixed with soft tap water. Amphibians such as axolotls prefer a hard water solution.
|
||||
|
||||
|
||||
== Composition ==
|
||||
Molarity of the component salts are as follows:
|
||||
|
||||
|
||||
== Notes ==
|
||||
|
||||
https://www.msu.edu/user/eisthen/lab/methods/animalcare/holtfr.html [link now dead]
|
||||
|
||||
|
||||
== References ==
|
||||
Armstrong, J.B., Duhon, S.T., and Malacinski, G.M. (1989) "Raising the axolotl in captivity". In J. B. Armstrong and G. M. Malacinski (eds.) Developmental Biology of the Axolotl. New York: Oxford University Press, pp. 220–227.
|
||||
16
data/en.wikipedia.org/wiki/Homogeneous_alignment-0.md
Normal file
16
data/en.wikipedia.org/wiki/Homogeneous_alignment-0.md
Normal file
@ -0,0 +1,16 @@
|
||||
---
|
||||
title: "Homogeneous alignment"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Homogeneous_alignment"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:00.232029+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In liquid crystals homogeneous alignment, sometimes called planar alignment, is the state of alignment where molecules align in parallel to a substrate. The opposite method is homeotropic alignment.
|
||||
For planar alignment - polyimides can be used. One of the popular ones is PI-2555.
|
||||
The surface has to be rubbed by paper or by a velvet or similar cloth in order to make the alignment axis parallel to the rubbing. However the exact mechanism of this alignment is not entirely clear.
|
||||
|
||||
|
||||
== References ==
|
||||
26
data/en.wikipedia.org/wiki/Homonuclear_molecule-0.md
Normal file
26
data/en.wikipedia.org/wiki/Homonuclear_molecule-0.md
Normal file
@ -0,0 +1,26 @@
|
||||
---
|
||||
title: "Homonuclear molecule"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Homonuclear_molecule"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:01.464648+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, homonuclear molecules, or elemental molecules, or homonuclear species, are molecules composed of only one element. Homonuclear molecules may consist of various numbers of atoms. The size of the molecule an element can form depends on the element's properties, and some elements form molecules of more than one size. The most familiar homonuclear molecules are diatomic molecules, which consist of two atoms, although not all diatomic molecules are homonuclear. Homonuclear diatomic molecules include hydrogen (H2), oxygen (O2), nitrogen (N2) and all of the halogens. Ozone (O3) is a common triatomic homonuclear molecule. Homonuclear tetratomic molecules include arsenic (As4) and phosphorus (P4).
|
||||
Allotropes are different chemical forms of the same element (not containing any other element). In that sense, allotropes are all homonuclear. Many elements have multiple allotropic forms. In addition to the most common form of gaseous oxygen, O2, and ozone, there are other allotropes of oxygen. Sulfur forms several allotropes containing different numbers of sulfur atoms, including diatomic, triatomic, hexatomic and octatomic (S2, S3, S6, S8) forms, though the first three are rare. The element carbon is known to have a number of homonuclear molecules, including diamond and graphite.
|
||||
Sometimes a cluster of atoms of a single kind of metallic element is considered a single molecule.
|
||||
|
||||
|
||||
== See also ==
|
||||
Heteronuclear molecule
|
||||
Category:Homonuclear diatomic molecules
|
||||
Category:Homonuclear triatomic molecules
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Media related to Homonuclear molecules at Wikimedia Commons
|
||||
19
data/en.wikipedia.org/wiki/Hose_barb-0.md
Normal file
19
data/en.wikipedia.org/wiki/Hose_barb-0.md
Normal file
@ -0,0 +1,19 @@
|
||||
---
|
||||
title: "Hose barb"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Hose_barb"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:02.656552+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Hose barbs are cylindrical pieces or parts for attaching and securing hoses. The barb-like rings on the cylindrical piece allow for an easy push-connection of flexible plastic or rubber tubing that is not easily disconnected. Hose barbs are used in machine perfusion and chemistry laboratory equipment. Hose barb fittings are small curved, bent or T-shaped pipes, hoses or tubes with hose barbs on at least one side used to join two or more pieces of piping (hosing, tubing) together. Hose barbs are commonly used in the agriculture industry to connect anhydrous ammonia (NH3) hoses.
|
||||
|
||||
|
||||
== See also ==
|
||||
Hose coupling
|
||||
Piping and plumbing fitting
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Houben-Weyl_Methods_of_Organic_Chemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:26.052107+00:00"
|
||||
date_saved: "2026-05-05T11:28:03.913363+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
28
data/en.wikipedia.org/wiki/Hydrogen_analyzer-0.md
Normal file
28
data/en.wikipedia.org/wiki/Hydrogen_analyzer-0.md
Normal file
@ -0,0 +1,28 @@
|
||||
---
|
||||
title: "Hydrogen analyzer"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Hydrogen_analyzer"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:05.111544+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A hydrogen analyzer is measurement instrument used to determine the concentration of hydrogen in gases, liquids or solid materials. It is used in industrial processes, energy systems, laboratory analysis and metallurgical applications such as hydrogen determination in steels and alloys.
|
||||
Hydrogen analyzers are widely used in oil and gas, chemical processing, power generation and hydrogen production systems. Measurement performance depends on operating conditions such as pressure, temperature and the composition of the background gas, all of which can influence sensor response and accuracy.
|
||||
A variety of measurement principles are used for hydrogen analysis, including thermal conductivity, electrochemical, catalytic and optical methods. Each technique has specific advantages and limitations depending on factors such as selectivity, measurement range, response time and environmental conditions.
|
||||
In practical applications, hydrogen measurement is often integrated into process control and safety systems. Standards such as ISO 14687 define hydrogen quality requirements for specific uses, including fuel cell applications, while metrology initiatives led by national laboratories support the development of traceable and reliable measurement techniques.
|
||||
|
||||
|
||||
== See also ==
|
||||
Hydrogen embrittlement
|
||||
Hydrogen leak testing
|
||||
Hydrogen sensor
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Hydrogen safety, sensors and monitoring – U.S. Department of Energy
|
||||
Hydrogen and alternative fuels – National Physical Laboratory
|
||||
59
data/en.wikipedia.org/wiki/Hypohalite-0.md
Normal file
59
data/en.wikipedia.org/wiki/Hypohalite-0.md
Normal file
@ -0,0 +1,59 @@
|
||||
---
|
||||
title: "Hypohalite"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Hypohalite"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:06.313124+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Hypohalites are chemical compounds containing the hypohalite ion, with the general formula XO⁻, where X is a halogen element from Group 17 of the periodic table (fluorine, chlorine, bromine, or iodine). Hypohalites are the conjugate bases of hypohalous acids (HOX) and represent the lowest oxidation state (+1) of halogens in their oxoanions.Hypohalites are also encountered in organic chemistry, often as acyl hypohalites (see the Hunsdiecker reaction). Sodium hypohalite is used in the haloform reaction as a test for methyl ketones.
|
||||
|
||||
|
||||
== Structure ==
|
||||
The hypohalite ion consists of a halogen atom covalently bonded to an oxygen atom, carrying an overall negative charge. The halogen is in the +1 oxidation state, and the oxygen is in the usual −2 state. The general formula is:
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
XO
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\textstyle {\ce {XO-}}}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
X
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {X}}}
|
||||
|
||||
is the halogen atom, and
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
O
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {O}}}
|
||||
|
||||
is the oxygen atom
|
||||
The Cl-O bond length in crystalline sodium hypochlorite pentahydrate, NaOCl·5H2O, is 1.686 Å, while in sodium hypobromite pentahydrate, NaOBr·5H2O, the Br–O bond length is 8% longer at 1.820 Å.
|
||||
|
||||
|
||||
== References ==
|
||||
@ -0,0 +1,30 @@
|
||||
---
|
||||
title: "Indian National Chemistry Olympiad"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Indian_National_Chemistry_Olympiad"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:08.773145+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
The Indian National Chemistry Olympiad (INChO for short) is an Olympiad in Chemistry held in India.
|
||||
The theory part of the INChO examination is held in end-January/beginning of February of every year. It is conducted by the Indian Association of Chemistry Teachers. School students (usually of standards 11 and 12) first need to qualify the National Standard Examination in Chemistry (NSEC) held in November of the preceding year. Among the 30,000+ students who sit for the NSEC, only the top 1% are selected for the INChO.
|
||||
About 35 students are selected from the written examination. A total of 30 students are chosen from these to attend the Orientation-Cum-Selection-Camp (OCSC), chemistry, held at HBCSE, Mumbai.
|
||||
Most students qualifying for the INChO are those completing their twelfth standard. However, in some cases, students have been selected for INChO at the end of the eleventh or tenth standard.
|
||||
|
||||
|
||||
== OCSC Chemistry ==
|
||||
The Orientation-Cum-Selection-Camp (OCSC), Chemistry, consists of rigorous training and testing in theory and experiment. The top four performers here are selected to represent India in the International Chemistry Olympiad. Before the INChO, the selected team undergoes rigorous training in theory and experiments in a Pre-Departure Training Camp held in HBCSE.
|
||||
|
||||
|
||||
== See also ==
|
||||
National Standard Examination in Chemistry
|
||||
Junior Science Talent Search Examination
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Information about India at the Science Olympiads
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Inorganic_Syntheses"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:36.777842+00:00"
|
||||
date_saved: "2026-05-05T11:28:10.049444+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
40
data/en.wikipedia.org/wiki/Interface_(matter)-0.md
Normal file
40
data/en.wikipedia.org/wiki/Interface_(matter)-0.md
Normal file
@ -0,0 +1,40 @@
|
||||
---
|
||||
title: "Interface (matter)"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Interface_(matter)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:11.275822+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In the physical sciences, an interface is the boundary between two spatial regions occupied by different matter, or by matter in different physical states. The interface between matter and air, or matter and vacuum, is called a surface, and studied in surface science. In thermal equilibrium, the regions in contact are called phases, and the interface is called a phase boundary. An example for an interface out of equilibrium is the grain boundary in polycrystalline matter.
|
||||
|
||||
|
||||
== Significance ==
|
||||
The importance of the interface depends on the type of system: the bigger the quotient area/volume, the greater the effect the interface will have. Consequently, interfaces are very important in systems with large interface area-to-volume ratios, such as colloids.
|
||||
|
||||
|
||||
== Shape ==
|
||||
Interfaces can be flat or curved. For example, oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat.
|
||||
|
||||
|
||||
== Surface tension ==
|
||||
Surface tension is the physical property which rules interface processes involving liquids. For a liquid film on flat surfaces, the liquid-vapor interface keeps flat to minimize interfacial area and system free energy. For a liquid film on rough surfaces, the surface tension tends to keep the meniscus flat, while the disjoining pressure makes the film conformal to the substrate. The equilibrium meniscus shape is a result of the competition between the capillary pressure and disjoining pressure.
|
||||
|
||||
|
||||
== Impacts and examples ==
|
||||
Interfaces may cause various optical phenomena, such as refraction. Optical lenses serve as an example of a practical application of the interface between glass and air.
|
||||
One topical interface system is the gas-liquid interface between aerosols and other atmospheric molecules.
|
||||
|
||||
|
||||
== See also ==
|
||||
Capillary surface, a surface that represents the boundary between two fluids
|
||||
Disjoining pressure
|
||||
Free surface
|
||||
Interface and colloid science
|
||||
Membrane
|
||||
Surface phenomenon
|
||||
|
||||
|
||||
== References ==
|
||||
@ -0,0 +1,27 @@
|
||||
---
|
||||
title: "Interior radiation control coating"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Interior_radiation_control_coating"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:12.491978+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Interior Radiation Control Coating Systems (IRCCS), sometimes referred to as radiant barrier coatings, are paints designed to provide thermal insulation to buildings.
|
||||
|
||||
|
||||
== Standards ==
|
||||
The American Society for Testing and Materials (ASTM) and the Reflective Insulation Manufacturer's Association (RIMA) have established an industry standard for evaluating paints claiming to have insulating characteristics. The energy conserving property has been defined as thermal emittance (the ability of a surface to release radiant energy that it has absorbed). Those coatings qualified as Interior Radiation Control Coatings must show a thermal emittance of 0.25 or less. This means that an IRCCS will block 75% or more of the radiant heat transfer.
|
||||
These low "E" coatings were originally developed in 1978 at the Solar Energy Corporation (SOLEC) in Princeton, New Jersey for use in tubular evacuated solar collectors. The developer, Robert Aresty, designed them to be used as low emissivity surfaces
|
||||
on glass to replace vacuum deposited surfaces. While SOLEC was doing collaborative work with the Florida Solar Energy Center (FSEC), Phillip Fairey, research director at FSEC and world-renowned researcher in radiant barriers discovered the availability of these coatings in the SOLEC labs. He immediately grasped that they might be used as a replacement for foil radiant barriers, and proceeded to perform experiments verifying their viability for this use. In 1986 these coatings were applied for the first commercial application in homes built by Centex Corporation.
|
||||
|
||||
|
||||
== Uses ==
|
||||
Uses of IRCCS includes residential and commercial building insulation, as well as industrial and automotive applications.
|
||||
|
||||
|
||||
== References ==
|
||||
ASTM C1321-04 "Standard Practice for Installation and Use of Interior Radiation Control Coating Systems (IRCCS) in Building Construction"
|
||||
RIMA has recently made a survey of coatings that claim to have insulating characteristics. To view this study go to http://www.rima.net, click on "Technical Info - Coatings Study"
|
||||
Triangle Radiant Barrier
|
||||
@ -0,0 +1,38 @@
|
||||
---
|
||||
title: "International Congress of Quantum Chemistry"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/International_Congress_of_Quantum_Chemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:13.686708+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
The International Congress of Quantum Chemistry (ICQC), is an international conference dedicated to the field of quantum chemistry. It is organized by the International Academy of Quantum Molecular Science. The first conference was held from July 4 to 10, 1973 in Menton, France. The first conference marked the "50th anniversary of the discovery of wave mechanics".
|
||||
|
||||
|
||||
== Past meetings ==
|
||||
In chronological order:
|
||||
|
||||
Menton, France July 4–10, 1973
|
||||
New Orleans (1976)
|
||||
Kyoto (1979)
|
||||
Uppsala (1982)
|
||||
Montreal (1985)
|
||||
Jerusalem (1988)
|
||||
Menton (1991)
|
||||
Prague (1994)
|
||||
Atlanta (1997)
|
||||
Menton (2000)
|
||||
Bonn (2003)
|
||||
Kyoto (2006)
|
||||
Helsinki (2009)
|
||||
Boulder (2012)
|
||||
Beijing (2015)
|
||||
Menton June 18–23 (2018)
|
||||
Bratislava (2023)
|
||||
Berkeley, California (2026)
|
||||
Papers from the Congresses have been published by the International Journal of Quantum Chemistry (IJQC).
|
||||
|
||||
|
||||
== References ==
|
||||
20
data/en.wikipedia.org/wiki/Iron_ring_(laboratory)-0.md
Normal file
20
data/en.wikipedia.org/wiki/Iron_ring_(laboratory)-0.md
Normal file
@ -0,0 +1,20 @@
|
||||
---
|
||||
title: "Iron ring (laboratory)"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Iron_ring_(laboratory)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:14.937092+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
An iron ring or ring clamp is an item of laboratory equipment which comprises a conjoined metal ring and radially-extending rod. In some cases, the rod terminates in a screw clamp for attachment to a retort stand or other support; in others, the rod may be attached to a stand by means of a laboratory clamp holder. Iron rings are commonly used in chemistry laboratories for supporting apparatus above the work surface, for example:
|
||||
|
||||
a tapered item such as a filter funnel or separatory funnel.
|
||||
a clay triangle, which itself supports an item such as a crucible.
|
||||
a wire gauze, which itself supports a flat-bottomed beaker or conical flask.
|
||||
a large, and therefore heavy, round-bottom flask.
|
||||
In some cases, a slot is cut in the side of the ring opposite the rod. This is to allow a funnel to be placed upon and removed from the ring from the side rather than from above, a safer procedure.
|
||||
|
||||
|
||||
== References ==
|
||||
14
data/en.wikipedia.org/wiki/LHASA-0.md
Normal file
14
data/en.wikipedia.org/wiki/LHASA-0.md
Normal file
@ -0,0 +1,14 @@
|
||||
---
|
||||
title: "LHASA"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/LHASA"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:16.188406+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
LHASA (Logic and Heuristics Applied to Synthetic Analysis) is a computer program developed in 1971 by the research group of Elias James Corey at the Harvard University Department of Chemistry. The program uses artificial intelligence techniques to discover sequences of reactions which may be used to synthesize a molecule. This program was one of the first to use a graphical interface to input and display chemical structures.
|
||||
|
||||
|
||||
== References ==
|
||||
17
data/en.wikipedia.org/wiki/LIESST-0.md
Normal file
17
data/en.wikipedia.org/wiki/LIESST-0.md
Normal file
@ -0,0 +1,17 @@
|
||||
---
|
||||
title: "LIESST"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/LIESST"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:17.341196+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry and physics, LIESST (Light-Induced Excited Spin-State Trapping) is a method of changing the electronic spin state of a compound by means of irradiation with light.
|
||||
|
||||
Many transition metal complexes with electronic configuration d4-d7 are capable of spin crossover (and d8 when molecular symmetry is lower than Oh). Spin crossover refers to where a transition from the high spin (HS) state to the low spin (LS) state or vice versa occurs. Alternatives to LIESST include using thermal changes and pressure to induce spin crossover. The metal most commonly exhibiting spin crossover is iron, with the first known example, an iron(III) tris(dithiocarbamato) complex, reported by Cambi et al. in 1931.
|
||||
For iron complexes, LIESST involves excitation of the low spin complex with green light to a triplet state. Two successive steps of intersystem crossing result in the high spin complex. Movement from the high spin complex to the low spin complex requires excitation with red light.
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/LNAPL_transmissivity"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T10:52:50.570687+00:00"
|
||||
date_saved: "2026-05-05T11:28:20.983551+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
22
data/en.wikipedia.org/wiki/Limiting_oxygen_index-0.md
Normal file
22
data/en.wikipedia.org/wiki/Limiting_oxygen_index-0.md
Normal file
@ -0,0 +1,22 @@
|
||||
---
|
||||
title: "Limiting oxygen index"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Limiting_oxygen_index"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:18.506981+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
The limiting oxygen index (LOI) is the minimum concentration of oxygen, expressed as a percentage, that will support combustion of a polymer. It is measured by passing a mixture of oxygen and nitrogen over a burning specimen, and reducing the oxygen level until a critical level is reached.
|
||||
LOI values for different plastics are determined by standardized tests, such as the ISO 4589 and ASTM D2863.
|
||||
The LOI value is also dependent on the surrounding temperature of the sample. The percent of oxygen required for combustion reduces as the surrounding temperature is increased.
|
||||
Plastics and cable material is tested for its LOI value at both ambient temperature and elevated temperature to understand its oxygen requirement under actual fire conditions.
|
||||
Materials with an LOI greater than the atmospheric oxygen concentration are called fire retardant materials.
|
||||
|
||||
|
||||
== See also ==
|
||||
Fire-resistance rating
|
||||
|
||||
|
||||
== References ==
|
||||
18
data/en.wikipedia.org/wiki/LiquiGlide-0.md
Normal file
18
data/en.wikipedia.org/wiki/LiquiGlide-0.md
Normal file
@ -0,0 +1,18 @@
|
||||
---
|
||||
title: "LiquiGlide"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/LiquiGlide"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:19.712453+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
LiquiGlide was a platform technology which creates slippery, liquid-impregnated surfaces that was developed at the Varanasi Research Group at Massachusetts Institute of Technology by Prof. Kripa Varanasi and his team of students and post doctorals Dave Smith, Rajeev Dhiman, Adam Paxson, Brian Solomon, and Chris Love. Possible applications include improving the flow rate of condiment bottles to avoid food waste, and preventing clogs in gas and oil tubes. The project came in second place in the Business Plan Contest and won the Audience Choice Award at the 2012 MIT $100K Entrepreneurship Competition. In March 2015, LiquiGlide signed a deal with Elmer's Products, the first company to use the technology. As of January 2017, the company had raised $25M from investors including Roadmap Capital, Structure Capital, Valia Investments, and Struck Capital. As of 2025, the company is no longer operating.
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Official site
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Lovibond_comparator"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T09:43:18.709605+00:00"
|
||||
date_saved: "2026-05-05T11:28:22.240041+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
23
data/en.wikipedia.org/wiki/Magic_number_(chemistry)-0.md
Normal file
23
data/en.wikipedia.org/wiki/Magic_number_(chemistry)-0.md
Normal file
@ -0,0 +1,23 @@
|
||||
---
|
||||
title: "Magic number (chemistry)"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Magic_number_(chemistry)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:23.528258+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
The concept of magic numbers in the field of chemistry refers to a specific property (such as stability) for only certain representatives among a distribution of structures. It was first recognized by inspecting the intensity of mass-spectrometric signals of rare gas cluster ions. Then, the same effect was observed with sodium clusters.
|
||||
|
||||
In case a gas condenses into clusters of atoms, the number of atoms in these clusters that are most likely to form varies between a few and hundreds. However, there are peaks at specific cluster sizes, deviating from a pure statistical distribution. Therefore, it was concluded that clusters of these specific numbers of atoms dominate due to their exceptional stability.
|
||||
One well-known example of such atomic condensation is the set of C60 , C70 and C84 fullerenes, shown in the figure on the right.
|
||||
The concept was also successfully applied to explain the mono-dispersed occurrence of thiolate-protected gold clusters; here the outstanding stability of specific cluster sizes is connected with their respective electronic configuration.
|
||||
The term magic numbers is also used in the field of nuclear physics. In this context, magic numbers refer to a specific number of protons or neutrons that forms complete nucleon shells.
|
||||
|
||||
|
||||
== See also ==
|
||||
Magic number (physics)
|
||||
|
||||
|
||||
== References ==
|
||||
43
data/en.wikipedia.org/wiki/Magnetic_3D_bioprinting-0.md
Normal file
43
data/en.wikipedia.org/wiki/Magnetic_3D_bioprinting-0.md
Normal file
@ -0,0 +1,43 @@
|
||||
---
|
||||
title: "Magnetic 3D bioprinting"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Magnetic_3D_bioprinting"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:24.728220+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Magnetic 3D bioprinting is a process that utilizes biocompatible magnetic nanoparticles to print cells into 3D structures or 3D cell cultures. In this process, cells are tagged with magnetic nanoparticles, thus making them magnetic. Once magnetic, these cells can be rapidly printed into specific 3D patterns using external magnetic forces that mimic tissue structure and function.
|
||||
|
||||
|
||||
== General principle ==
|
||||
Magnetic 3D bioprinting is an alternative to other 3D printing methods such as extrusion, photolithography, and stereolithography. Benefits of the technique include its rapid process (15 minutes – 1 hour), compared to the often days-long processes of others, the capacity for endogenous synthesis of extracellular matrix (ECM) without the need for an artificial protein substrate and fine spatial control, and the capacity for 3D cell culture models to be printed from simple spheroids and rings into more complex organotypic models such as the lung, aortic valve, and white fat.
|
||||
|
||||
|
||||
== Process ==
|
||||
|
||||
|
||||
=== Using magnetic nanoparticles ===
|
||||
The cells first need to be incubated in the presence of magnetic nanoparticles to make them susceptible to manipulation through magnetic fields. The system is a nanoparticle assembly consisting of gold, magnetic iron oxide, and poly-L-lysine which assists in adhesion to the cell membrane via electrostatic interactions. In this system, cells are printed into 3D patterns (rings or dots) using fields generated by permanent magnets. The cells within the printed construct interact with surrounding cells and the ECM to migrate, proliferate, and ultimately shrink the structure, typically within 24 hours.
|
||||
When used as a toxicity assay, this shrinkage varies with drug concentration and is a label-free metric of cell function that can be captured and measured with brightfield imaging. The size of the pattern can be captured using an iPod-based system, which is programmed using an app (Experimental Assistant) to image whole plates of up to 96 structures at intervals as short as one second.
|
||||
|
||||
|
||||
=== Using diamagnetism ===
|
||||
Cells can be assembled without using magnetic nanoparticles by employing diamagnetism. Some materials are more strongly attracted, or susceptible, to magnets than others. Materials with greater magnetic susceptibility will experience stronger attraction to a magnet and move towards it. The more weakly attracted material with lower susceptibility is displaced to lower magnetic field regions that lie away from the magnet. By designing magnetic fields through careful arrangement of magnets, it is possible to use the differences in the magnetic susceptibilities of two materials to concentrate only one within a volume.
|
||||
An example of usage of this technique is when bio-ink was formulated by suspending human breast cancer cells in a cell culture medium that contained the paramagnetic salt, diethylenetriaminepentaacetic acid gadolinium (III) dihydrogen salt hydrate (Gd-DTPA). Like most cells, these breast cancer cells are much more weakly attracted by magnets than Gd-DTPA, which is an FDA-approved MRI contrast agent for use in humans. Therefore, when a magnetic field was applied, the salt hydrate moved towards the magnets, displacing the cells to a predetermined area of minimum magnetic field strength, which seeded the formation of a 3D cell cluster.
|
||||
|
||||
|
||||
== Applications ==
|
||||
Magnetic 3D bioprinting can be used to screen for cardiovascular toxicity, which accounts for 30% of cardiac drug withdrawals. Vascular smooth muscle cells are magnetically printed into 3D rings to mimic blood vessels that can contract and dilate. This system could potentially replace experiments using ex vivo tissue, which are costly and yield little data per experiment. Furthermore, magnetic 3D bioprinting can use human cells to approximate a human in vivo response better than with an animal model. This has been demonstrated by the bioassay which combines the benefits of 3D bioprinting in building tissue-like structures for study with the speed of magnetic printing.
|
||||
|
||||
|
||||
== See also ==
|
||||
Bio-printing
|
||||
Organovo
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== Further reading ==
|
||||
25
data/en.wikipedia.org/wiki/Meker–Fisher_burner-0.md
Normal file
25
data/en.wikipedia.org/wiki/Meker–Fisher_burner-0.md
Normal file
@ -0,0 +1,25 @@
|
||||
---
|
||||
title: "Meker–Fisher burner"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Meker–Fisher_burner"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:25.862798+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Méker burner (sometimes named Méker–Fisher burner for its distributor in USA) is an ambient air laboratory burner that produces multiple open gas flames, used for heating, sterilization and combustion. It is used when laboratory work requires a hotter flame than one attainable using a Bunsen burner, or when a flame of larger diameter is desired, such as when working with inoculation loop needing sterilization or in some glassblowing operations. The burner was introduced by French chemist Georges Méker in an article published in 1905.
|
||||
The Méker burner heating power can be around 3.6 kW using liquefied petroleum gas. Flame temperatures of up to 1,100–1,200 °C (2,000–2,200 °F) are achievable. Compared with a Bunsen burner, the lower part of its tube has more openings with larger total cross-section, admitting more air and facilitating better mixing of air and gaseous fuel. The tube is wider and its top is covered with a plate mesh, which separates the flame into an array of smaller flames with a common external envelope, ensures uniform heating, also preventing flashback to the bottom of the tube which is a risk at high air-to-fuel ratios and limits the maximal rate of air intake in a Bunsen burner. The flame burns almost without noise, unlike the Bunsen or Teclu burners.
|
||||
|
||||
|
||||
== See also ==
|
||||
Bunsen burner
|
||||
Teclu burner
|
||||
|
||||
|
||||
== References ==
|
||||
|
||||
|
||||
== External links ==
|
||||
Media related to Meker-Fisher burners at Wikimedia Commons
|
||||
Video of Meker burner in use.
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Melchett_Medal"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:24:27.418113+00:00"
|
||||
date_saved: "2026-05-05T11:28:27.134267+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Merck_Index"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:58:53.694685+00:00"
|
||||
date_saved: "2026-05-05T11:28:28.397519+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
15
data/en.wikipedia.org/wiki/Merrifield_resin-0.md
Normal file
15
data/en.wikipedia.org/wiki/Merrifield_resin-0.md
Normal file
@ -0,0 +1,15 @@
|
||||
---
|
||||
title: "Merrifield resin"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Merrifield_resin"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:29.595299+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Merrifield resin is a cross-linked polystyrene resin that carries a chloromethyl functional group. Merrifield resin is named after its inventor, Robert Bruce Merrifield (1984 winner of the Nobel Prize in Chemistry) and is used in solid-phase synthesis. The material is typically available as white beads. These beads are allowed to swell in suitable solvents (ethyl acetate, DMF, DMSO), which then allows the reagents to substitute the chloride substituents.
|
||||
Merrifield Resin can be prepared by chloromethylation of polystyrene or by the copolymerization of styrene and 4-vinylbenzyl chloride.
|
||||
|
||||
|
||||
== References ==
|
||||
16
data/en.wikipedia.org/wiki/Mohr_pipette-0.md
Normal file
16
data/en.wikipedia.org/wiki/Mohr_pipette-0.md
Normal file
@ -0,0 +1,16 @@
|
||||
---
|
||||
title: "Mohr pipette"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Mohr_pipette"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:30.815016+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A Mohr pipette, also known as a graduated pipette, is a type of pipette used to measure the volume of the liquid dispensed, although not as accurately as a volumetric pipette. These use a series of marked lines (as on a graduated cylinder) to indicate the different volumes. They come in a variety of sizes, and are used much like a burette, in that the volume is found by calculating the difference of the liquid level before and after.
|
||||
The last graduation mark is some distance from the tip, to avoid errors in measuring the narrower volume of the nozzle.
|
||||
It was invented by Karl Friedrich Mohr, the father of volumetric analysis.
|
||||
|
||||
|
||||
== References ==
|
||||
14
data/en.wikipedia.org/wiki/Mole_map_(chemistry)-0.md
Normal file
14
data/en.wikipedia.org/wiki/Mole_map_(chemistry)-0.md
Normal file
@ -0,0 +1,14 @@
|
||||
---
|
||||
title: "Mole map (chemistry)"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Mole_map_(chemistry)"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:32.048718+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, a mole map is a graphical representation of an algorithm that compares molar mass, number of particles per mole, and factors from balanced equations or other formulae. They are often used in undergraduate-level chemistry courses as a tool to teach the basics of stoichiometry and unit conversion.
|
||||
|
||||
|
||||
== References ==
|
||||
571
data/en.wikipedia.org/wiki/Molecular_autoionization-0.md
Normal file
571
data/en.wikipedia.org/wiki/Molecular_autoionization-0.md
Normal file
@ -0,0 +1,571 @@
|
||||
---
|
||||
title: "Molecular autoionization"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Molecular_autoionization"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:33.291091+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, molecular autoionization (or self-ionization) is a chemical reaction between molecules of the same substance to produce ions. If a pure liquid partially dissociates into ions, it is said to be self-ionizing. In most cases the oxidation number on all atoms in such a reaction remains unchanged. Such autoionization can be protic (H+ transfer), or non-protic.
|
||||
|
||||
|
||||
== Examples ==
|
||||
|
||||
|
||||
=== Protic solvents ===
|
||||
Protic solvents often undergo some autoionization (in this case autoprotolysis):
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
2
|
||||
|
||||
|
||||
H
|
||||
|
||||
2
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
O
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
H
|
||||
|
||||
3
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
O
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
OH
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {2 H2O <=> H3O+ + OH-}}}
|
||||
|
||||
|
||||
The self-ionization of water is particularly well studied, due to its implications for acid-base chemistry of aqueous solutions.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
2
|
||||
|
||||
|
||||
NH
|
||||
|
||||
3
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
NH
|
||||
|
||||
4
|
||||
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
NH
|
||||
|
||||
2
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {2 NH3 <=> NH4+ + NH2-}}}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
2
|
||||
|
||||
|
||||
H
|
||||
|
||||
2
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
SO
|
||||
|
||||
4
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
H
|
||||
|
||||
3
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
SO
|
||||
|
||||
4
|
||||
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
HSO
|
||||
|
||||
4
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {2 H2SO4 <=> H3SO4+ + HSO4-}}}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
3
|
||||
|
||||
HF
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
H
|
||||
|
||||
2
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
F
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
HF
|
||||
|
||||
2
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {3 HF <=> H2F+ + HF2-}}}
|
||||
|
||||
|
||||
Here proton transfer between two HF combines with homoassociation of F− and a third HF to form HF−2
|
||||
|
||||
|
||||
=== Non-protic solvents ===
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
2
|
||||
|
||||
|
||||
PF
|
||||
|
||||
5
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
PF
|
||||
|
||||
6
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
+
|
||||
|
||||
PF
|
||||
|
||||
4
|
||||
|
||||
|
||||
+
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {2 PF5 <=> PF6- + PF4+}}}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
N
|
||||
|
||||
2
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
O
|
||||
|
||||
4
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
NO
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
NO
|
||||
|
||||
3
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {N2O4 <=> NO+ + NO3-}}}
|
||||
|
||||
|
||||
Here the nitrogen oxidation numbers change from (+4 and +4) to (+3 and +5).
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
2
|
||||
|
||||
|
||||
BrF
|
||||
|
||||
3
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
↽
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
⇀
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
BrF
|
||||
|
||||
2
|
||||
|
||||
|
||||
+
|
||||
|
||||
|
||||
+
|
||||
|
||||
BrF
|
||||
|
||||
4
|
||||
|
||||
|
||||
−
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
{\displaystyle {\ce {2 BrF3 <=> BrF2+ + BrF4-}}}
|
||||
|
||||
|
||||
These solvents all possess atoms with odd atomic numbers, either nitrogen or a halogen. Such atoms enable the formation of singly charged, nonradical ions (which must have at least one odd-atomic-number atom), which are the most favorable autoionization products. Protic solvents, mentioned previously, use hydrogen for this role. Autoionization would be much less favorable in solvents such as sulfur dioxide or carbon dioxide, which have only even-atomic-number atoms.
|
||||
|
||||
|
||||
=== Coordination chemistry ===
|
||||
Autoionization is not restricted to neat liquids or solids. Solutions of metal complexes exhibit this property. For example, compounds of the type FeX2(terpyridine) (where X = Cl or Br) are unstable with respect to autoionization forming [Fe(terpyridine)2]2+[FeX4]2−.
|
||||
|
||||
|
||||
== See also ==
|
||||
Ionization
|
||||
Ion association
|
||||
Solvent system definition of acids and bases
|
||||
|
||||
|
||||
== References ==
|
||||
24
data/en.wikipedia.org/wiki/Molecular_entity-0.md
Normal file
24
data/en.wikipedia.org/wiki/Molecular_entity-0.md
Normal file
@ -0,0 +1,24 @@
|
||||
---
|
||||
title: "Molecular entity"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Molecular_entity"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:34.461896+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry and physics, a molecular entity, or chemical entity, is "any constitutionally or isotopically distinct atom, molecule, ion, ion pair, radical, radical ion, complex, conformer, etc., identifiable as a separately distinguishable entity". A molecular entity is any singular entity, irrespective of its nature, used to concisely express any type of chemical particle that can exemplify some process: for example, atoms, molecules, ions, etc. can all undergo a chemical reaction.
|
||||
Chemical species is the macroscopic equivalent of molecular entity and refers to sets or ensembles of molecular entities.
|
||||
According to IUPAC, "The degree of precision necessary to describe a molecular entity depends on the context. For example 'hydrogen molecule' is an adequate definition of a certain molecular entity for some purposes, whereas for others it is necessary to distinguish the electronic state and/or vibrational state and/or nuclear spin, etc. of the hydrogen molecule."
|
||||
|
||||
|
||||
== See also ==
|
||||
Amount of substance - a quantity proportional to the number of entities in a substance
|
||||
Mole (unit) - an aggregate of entities given by the Avogadro number
|
||||
New chemical entity
|
||||
Chemical Entities of Biological Interest
|
||||
Particle
|
||||
|
||||
|
||||
== References ==
|
||||
23
data/en.wikipedia.org/wiki/Molecular_property-0.md
Normal file
23
data/en.wikipedia.org/wiki/Molecular_property-0.md
Normal file
@ -0,0 +1,23 @@
|
||||
---
|
||||
title: "Molecular property"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Molecular_property"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:35.657910+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Molecular properties include the chemical properties, physical properties, and structural properties of molecules, including drugs. Molecular properties typically do not include pharmacological or biological properties of a chemical compound.
|
||||
|
||||
|
||||
== See also ==
|
||||
Biological activity
|
||||
Chemical property
|
||||
Chemical structure
|
||||
Lipinski's rule of five, describing molecular properties of drugs
|
||||
Physical property
|
||||
QSAR, quantitative structure-activity relationship
|
||||
|
||||
|
||||
== References ==
|
||||
16
data/en.wikipedia.org/wiki/Monoxide-0.md
Normal file
16
data/en.wikipedia.org/wiki/Monoxide-0.md
Normal file
@ -0,0 +1,16 @@
|
||||
---
|
||||
title: "Monoxide"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Monoxide"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:36.872859+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
A monoxide is any oxide containing only one atom of oxygen. A well known monoxide is carbon monoxide; see carbon monoxide poisoning.
|
||||
The prefix mono (Greek for "one") is used in chemical nomenclature. In proper nomenclature, the prefix is not always used in compounds with one oxygen atom. Generally, when the oxygen is bonded to a nonmetal, the prefix mono is used. However, when the oxygen atom bonds to a metal, the prefix is dropped. For instance, in the compound K2O, potassium (K) is a metal and therefore its proper name is potassium oxide, rather than potassium monoxide.
|
||||
Among monoxides, carbon monoxide and dihydrogen monoxide (water) are both neutral, germanium(II) oxide is distinctly acidic, and both tin(II) oxide and lead(II) oxide are amphoteric. aluminiumdioxide
|
||||
|
||||
|
||||
== References ==
|
||||
21
data/en.wikipedia.org/wiki/Nital-0.md
Normal file
21
data/en.wikipedia.org/wiki/Nital-0.md
Normal file
@ -0,0 +1,21 @@
|
||||
---
|
||||
title: "Nital"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Nital"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:38.076914+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
Nital is a solution of nitric acid and alcohol commonly used for etching of metals. It is especially suitable for revealing the microstructure of carbon steels. The alcohol can be methanol or ethanol.
|
||||
Mixtures of ethanol and nitric acid are potentially explosive. This commonly occurs by gas evolution, although ethyl nitrate can also be formed. Methanol is not liable to explosion but it is toxic.
|
||||
A solution of ethanol and nitric acid will become explosive if the concentration of nitric acid reaches over 10% (by weight). Solutions above 5% should not be stored in closed containers. Nitric acid will continue to act as an oxidant in dilute and cold conditions.
|
||||
|
||||
|
||||
== In popular culture ==
|
||||
Nital is a critical plot element in the Japanese manga series Dr. Stone, whose story revolves around the mysterious petrification of all mankind. Initially made from nitric acid that they produce from bat guano found in a cave, they then produce nitric acid by using the Ostwald process (using platinum as a catalyst and urine as an ingredient) and highly distilled alcohol with a ratio of 3:7. Nital is dubbed the revival fluid with the unique property of undoing and freeing the petrified people.
|
||||
In The Simpsons S18, E20, a snake knocks over a flask of ethanol and a flask of nitric acid, creating fumes from which their dog saves Bart.
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Nomenclature_of_Organic_Chemistry"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:59:04.740313+00:00"
|
||||
date_saved: "2026-05-05T11:28:39.322094+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
18
data/en.wikipedia.org/wiki/Octatomic_element-0.md
Normal file
18
data/en.wikipedia.org/wiki/Octatomic_element-0.md
Normal file
@ -0,0 +1,18 @@
|
||||
---
|
||||
title: "Octatomic element"
|
||||
chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Octatomic_element"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T11:28:40.538384+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
In chemistry, an octatomic element is an element that, at some standard temperature and pressure, is in a configuration of eight atoms bound together (a homonuclear molecule). The canonical example is sulfur, S8, but red selenium is also an octatomic element stable at room temperature. Octaoxygen is also known, but it is extremely unstable.
|
||||
|
||||
|
||||
== See also ==
|
||||
Diatomic element
|
||||
|
||||
|
||||
== References ==
|
||||
@ -4,7 +4,7 @@ chunk: 1/1
|
||||
source: "https://en.wikipedia.org/wiki/Oil_bath"
|
||||
category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T06:35:45.874781+00:00"
|
||||
date_saved: "2026-05-05T11:28:41.797105+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
||||
14
data/en.wikipedia.org/wiki/Oligonol-0.md
Normal file
14
data/en.wikipedia.org/wiki/Oligonol-0.md
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---
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title: "Oligonol"
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source: "https://en.wikipedia.org/wiki/Oligonol"
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category: "reference"
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tags: "science, encyclopedia"
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date_saved: "2026-05-05T11:28:42.940066+00:00"
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instance: "kb-cron"
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---
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Oligonol is a mixture of low molecular weight polyphenols found in lychee fruit. Oligonol is thought to have antioxidant and anti-influenza virus actions. In addition, preliminary research in animal models suggest it may improve blood flow in organs, maintain muscle, reduce weight, and protect skin from harmful UV rays. Little is known about the long term safety of supplements containing oligonol due to the lack of scientific research.
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== References ==
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@ -4,7 +4,7 @@ chunk: 1/1
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source: "https://en.wikipedia.org/wiki/On_a_New_Organic_Base_in_the_Coca_Leaves"
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category: "reference"
|
||||
tags: "science, encyclopedia"
|
||||
date_saved: "2026-05-05T08:59:10.618342+00:00"
|
||||
date_saved: "2026-05-05T11:28:44.190286+00:00"
|
||||
instance: "kb-cron"
|
||||
---
|
||||
|
||||
|
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