Titration is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte. A reagent, termed the titrant or titrator, is prepared as a standard solution of known concentration and volume. The titrant reacts with a solution of analyte to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the titration volume.
Schoorl is a village in the Dutch province of North Holland. It is a part of the municipality of Bergen, and lies about 8 km northwest of Alkmaar. Until 2001, Schoorl was also a municipality of its own.
A millionaire is an individual whose net worth or wealth is equal to or exceeds one million units of currency. Depending on the currency, a certain level of prestige is associated with being a millionaire. Many national currencies have, or have had at various times, a low unit value, in many cases due to past inflation. It is obviously much easier and less significant to be a millionaire in those currencies, thus a millionaire in Hong Kong or Taiwan, for example, may be merely averagely wealthy, or perhaps less wealthy than average. A millionaire in Zimbabwe in 2007 could have been extremely poor. Because of this, the term 'millionaire' generally refers to those whose assets total at least one million units of a high-value currency, such as the United States dollar, euro, or pound sterling.
In astronomy, astrophysics and geophysics, a mass concentration is a region of a planet's or moon's crust that contains a large positive gravity anomaly. In general, the word "mascon" can be used as a noun to refer to an excess distribution of mass on or beneath the surface of an astronomical body, such as is found around Hawaii on Earth. However, this term is most often used to describe a geologic structure that has a positive gravitational anomaly associated with a feature that might otherwise have been expected to have a negative anomaly, such as the "mascon basins" on the Moon.
A contour line of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function parallel to the -plane. More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value.
Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs. The effects can include those manifested within animals, microorganisms, or combinations of organisms.
In topography, prominence measures the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit within it. It is a measure of the independence of a summit. The key col ("saddle") around the peak is a unique point on this contour line and the parent peak is some higher mountain, selected according to various criteria.
Cyclohexanol is the organic compound with the formula HOCH(CH2)5. The molecule is related to cyclohexane by replacement of one hydrogen atom by a hydroxyl group. This compound exists as a deliquescent colorless solid with a camphor-like odor, which, when very pure, melts near room temperature. Millions of tonnes are produced annually, mainly as a precursor to nylon.
In chemical kinetics, the overall rate of a reaction is often approximately determined by the slowest step, known as the rate-determining step or rate-limiting step. For a given reaction mechanism, the prediction of the corresponding rate equation is often simplified by using this approximation of the rate-determining step.
An air quality index (AQI) is an indicator developed by government agencies to communicate to the public how polluted the air currently is or how polluted it is forecast to become. As air pollution levels rise, so does the AQI, along with the associated public health risk. Children, the elderly and individuals with respiratory or cardiovascular problems are typically the first groups affected by poor air quality. When the AQI is high, governmental bodies generally encourage people to reduce physical activity outdoors, or even avoid going out altogether. When wildfires result in a high AQI, the use of masks such as N95 respirators outdoors and air purifiers incorporating HEPA filters indoors are also encouraged.
In economics, market concentration is a function of the number of firms and their respective shares of the total production in a market. Market concentration is the portion of a given market's market share that is held by a small number of businesses. To ascertain whether an industry is competitive or not, it is employed in antitrust law and economic regulation. When market concentration is high, it indicates that a few firms dominate the market and oligopoly or monopolistic competition is likely to exist. In most cases, high market concentration produces undesirable consequences such as reduced competition and higher prices.
Botanical prospecting for uranium is a method of finding uranium deposits either by observation of plant life growing on the surface, or by geochemical analysis of plant material.
The insulin index of food represents how much it elevates the concentration of insulin in the blood during the two-hour period after the food is ingested. The index is similar to the glycemic index (GI) and glycemic load (GL), but rather than relying on blood glucose levels, the Insulin Index is based upon blood insulin levels. The Insulin Index represents a comparison of food portions with equal overall caloric content, while GI represents a comparison of portions with equal digestible carbohydrate content and the GL represents portions of a typical serving size for various foods. The Insulin Index can be more useful than either the glycemic index or the glycemic load because certain foods cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load.
Fractography is the study of the fracture surfaces of materials. Fractographic methods are routinely used to determine the cause of failure in engineering structures, especially in product failure and the practice of forensic engineering or failure analysis. In material science research, fractography is used to develop and evaluate theoretical models of crack growth behavior.
In meteorology, station models are symbolic illustrations showing the weather occurring at a given reporting station. Meteorologists created the station model to fit a number of weather elements into a small space on weather maps. This allows map users to analyze patterns in atmospheric pressure, temperature, wind speed and direction, cloud cover, precipitation, and other parameters. The most common station plots depict surface weather observations although upper air plots at various mandatory levels are also frequently depicted.
The Lovibond comparator is an example of a colorimeter made in Britain by The Tintometer Ltd. It was invented in the 19th century by Joseph Williams Lovibond and updated versions are still available.
Ski orienteering (SkiO) is a cross-country skiing endurance winter racing sport and one of the four orienteering disciplines recognized by the IOF. A successful ski orienteer combines high physical endurance, strength and excellent technical skiing skills with the ability to navigate and make the best route choices while skiing at a high speed.
Hexachlorocyclopentadiene (HCCPD), also known as C-56, Graphlox, and HRS 1655, is an organochlorine compound with the formula C5Cl6. It is a precursor to pesticides, flame retardants, and dyes. It is a colourless liquid, although commercial samples appear lemon-yellow liquid sometimes with a bluish vapour. Many of its derivatives proved to be highly controversial, as studies showed them to be persistent organic pollutants. An estimated 270,000 tons were produced until 1976, and smaller amounts continue to be produced today. Two prominent manufacturers are Velsicol Chemical Corporation in the US and by Jiangsu Anpon Electrochemicals Co. in China.
Post-mortem chemistry, also called necrochemistry or death chemistry, is a subdiscipline of chemistry in which the chemical structures, reactions, processes and parameters of a dead organism is investigated. Post-mortem chemistry plays a significant role in forensic pathology. Biochemical analyses of vitreous humor, cerebrospinal fluid, blood and urine is important in determining the cause of death or in elucidating forensic cases.
