Chemical reactionA chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.
Free-radical halogenationIn organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under application of UV light. The reaction is used for the industrial synthesis of chloroform (CHCl3), dichloromethane (CH2Cl2), and hexachlorobutadiene. It proceeds by a free-radical chain mechanism. The chain mechanism is as follows, using the chlorination of methane as a usual example: 1. Initiation: Splitting or homolysis of a chlorine molecule to form two chlorine atoms, initiated by ultraviolet radiation .
Nitrile rubberNitrile rubber, also known as nitrile butadiene rubber, NBR, Buna-N, and acrylonitrile butadiene rubber, is a synthetic rubber derived from acrylonitrile (ACN) and butadiene. Trade names include Perbunan, Nipol, Krynac and Europrene. This rubber is unusual in being resistant to oil, fuel, and other chemicals. NBR is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, grommets, and self-sealing fuel tanks. It is used in the nuclear industry to make protective gloves.
Primary electionPrimary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the country and administrative divisions within the country, voters might consist of the general public in what is called an open primary, or solely the members of a political party in what is called a closed primary.
At-largeAt large (before a noun: at-large) is a description for members of a governing body who are elected or appointed to represent a whole membership or population (notably a city, county, state, province, nation, club or association), rather than a subset. In multi-hierarchical bodies, the term rarely extends to a tier beneath the highest division. A contrast is implied, with certain electoral districts or narrower divisions. It can be given to the associated territory, if any, to denote its undivided nature, in a specific context.
Plasma polymerizationPlasma polymerization (or glow discharge polymerization) uses plasma sources to generate a gas discharge that provides energy to activate or fragment gaseous or liquid monomer, often containing a vinyl group, in order to initiate polymerization. Polymers formed from this technique are generally highly branched and highly cross-linked, and adhere to solid surfaces well. The biggest advantage to this process is that polymers can be directly attached to a desired surface while the chains are growing, which reduces steps necessary for other coating processes such as grafting.
Bisphenol ABisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation reaction of phenol and acetone. Global production in 2022 was estimated to be in the region of 10 million tonnes. BPA's largest single application is as a co-monomer in the production of polycarbonates, which accounts for 65–70% of all BPA production.
United States House of RepresentativesThe United States House of Representatives is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together, they comprise the national bicameral legislature of the United States. The House's composition was established by Article One of the United States Constitution. The House is composed of representatives who, pursuant to the Uniform Congressional District Act, sit in single member congressional districts allocated to each state on the basis of population as measured by the United States census, with each district having one representative, provided that each state is entitled to at least one.
LipophilicityLipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipophilic (translated as "fat-loving" or "fat-liking"), and the axiom that "like dissolves like" generally holds true. Thus lipophilic substances tend to dissolve in other lipophilic substances, but hydrophilic ("water-loving") substances tend to dissolve in water and other hydrophilic substances.
Central nervous system depressionCentral nervous system (CNS) depression is a physiological state that can result in a decreased rate of breathing, decreased heart rate, and loss of consciousness, possibly leading to coma or death. It is the result of inhibited or suppressed brain activity. Depression of the central nervous system is generally caused by the use of depressant drugs such as ethanol, opioids, barbiturates, benzodiazepines, general anesthetics, and anticonvulsants such as pregabalin used to treat epilepsy.
