IdentifierAn identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique class of objects, where the "object" or class may be an idea, physical countable object (or class thereof), or physical noncountable substance (or class thereof). The abbreviation Id often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those.
LigninLignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid.
Chemical industryThe chemical industry comprises the companies that develop and produce industrial, specialty and other chemicals. Central to the modern world economy, it converts raw materials (oil, natural gas, air, water, metals, and minerals) into industrial and consumer products. The plastics industry contains some overlap, as some chemical companies produce plastics as well as chemicals. Various professionals are involved in the chemical industry including chemical engineers, chemists and lab technicians.
HydrolysisHydrolysis (haɪˈdrɒlɪsɪs; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g.
Chemical processIn a scientific sense, a chemical process is a method or means of somehow changing one or more chemicals or chemical compounds. Such a chemical process can occur by itself or be caused by an outside force, and involves a chemical reaction of some sort. In an "engineering" sense, a chemical process is a method intended to be used in manufacturing or on an industrial scale (see Industrial process) to change the composition of chemical(s) or material(s), usually using technology similar or related to that used in chemical plants or the chemical industry.
Thermodynamic temperatureThermodynamic temperature is a quantity defined in thermodynamics as distinct from kinetic theory or statistical mechanics. Historically, thermodynamic temperature was defined by Lord Kelvin in terms of a macroscopic relation between thermodynamic work and heat transfer as defined in thermodynamics, but the kelvin was redefined by international agreement in 2019 in terms of phenomena that are now understood as manifestations of the kinetic energy of free motion of microscopic particles such as atoms, molecules, and electrons.
Substrate (chemistry)In chemistry, the term substrate is highly context-dependent. Broadly speaking, it can refer either to a chemical species being observed in a chemical reaction, or to a surface on which other chemical reactions or microscopy are performed. In the former sense, a reagent is added to the substrate to generate a product through a chemical reaction. The term is used in a similar sense in synthetic and organic chemistry, where the substrate is the chemical of interest that is being modified.
Lignocellulosic biomassLignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Any biomass rich in cellulose, hemicelluloses, and lignin are commonly referred to as lignocellulosic biomass. Each component has a distinct chemical behavior.
Scale of temperatureScale of temperature is a methodology of calibrating the physical quantity temperature in metrology. Empirical scales measure temperature in relation to convenient and stable parameters or reference points, such as the freezing and boiling point of water. Absolute temperature is based on thermodynamic principles: using the lowest possible temperature as the zero point, and selecting a convenient incremental unit. Celsius, Kelvin, and Fahrenheit are common temperature scales.
Unique identifierA unique identifier (UID) is an identifier that is guaranteed to be unique among all identifiers used for those objects and for a specific purpose. The concept was formalized early in the development of computer science and information systems. In general, it was associated with an atomic data type. In relational databases, certain attributes of an entity that serve as unique identifiers are called primary keys. In mathematics, set theory uses the concept of element indices as unique identifiers.
