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Alibaba Group Holding Limited, branded as Alibaba, is a Chinese multinational technology company specializing in e-commerce, retail, Internet, and technology. Founded on 28 June 1999 [1] in Hangzhou, Zhejiang, the company provides consumer-to-consumer (C2C), business-to-consumer (B2C), and business-to-business (B2B) sales services via Chinese ...
What links here Related changes Upload file Special pages Permanent link Page information Cite this page Get shortened URL Download QR code The S&P 500 is a stock market index maintained by S&P Dow Jones Indices.It comprises 503 common stocks which are issued by 500 large-cap companies traded on American stock exchanges (including the 30 companies that compose the Dow Jones Industrial Average).
Potassium is a chemical element; it has symbol K (from Neo-Latin kalium) and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife.[8] Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of ...
- silvery white, faint bluish-purple hue when exposed to air
- group 1: hydrogen and alkali metals
- 19
- Composition
- Formation
- Discovery
- Other Deposits
- Commercial Form
- Usage
- Specific Varieties
- Microbial Degradation
- Climatologic Importance
- Safety Considerations
Each deposit of diatomaceous earth is different, with varying blends of pure diatomaceous earth combined with other natural clays and minerals. The diatoms in each deposit contain different amounts of silica, depending on the sedimentation conditions, on the presence of other sediments (clay, sand, volcanic ashes), and on the age of the deposit (di...
Diatomite forms by the accumulation of the amorphous silica (opal, SiO2·nH2O) remains of dead diatoms (microscopic single-celled algae) in lake sediment or marine sediments. The fossil remains consist of a pair of symmetrical shells or frustules. Marine diatomites are found in association with a wide variety of other rock types but lacustrine diato...
In 1836 or 1837, German peasant Peter Kasten discovered diatomaceous earth (German: Kieselgur) when sinking a well on the northern slopes of the Haußelberg hill, on Lüneburg Heath in North Germany. The extraction site on Lüneburg Heath was 1863–1994 Neuohe, while the storage sites were: The deposits are up to 28 meters (92 ft) thick and are all of ...
In Poland diatomaceous earth deposits are found in Jawornik, and are composed mostly of diatomaceous skeletons (frustules). In Germany, diatomaceous earth was also extracted at Altenschlirf on the Vogelsberg (Upper Hesse) and at Klieken (Saxony-Anhalt). There is a layer of diatomaceous earth more than 6 meters (20 ft) thick in the nature reserve of...
Diatomaceous earth is available commercially in several formats: 1. granulateddiatomaceous earth is a raw material simply crushed for convenient packaging 2. milled or micronizeddiatomaceous earth is especially fine (10 μm to 50 μm) and used for insecticides. 3. calcineddiatomaceous earth is heat-treated and activated for filters.
Explosives
In 1866, Alfred Nobel discovered that nitroglycerin could be made much more stable if absorbed in diatomite (kieselguhr). This allowed a much safer transport and handling than pure nitroglycerin under the liquid form. Nobel patented this mixture as dynamitein 1867; the mixture is also called guhr dynamite by reference to the German term kieselguhr.
Filtration
The Celle engineer, Wilhelm Berkefeld, recognized the ability of the diatomaceous earth to filter and developed tubular filters (known as filter candles) fired from diatomaceous earth. During the cholera epidemic in Hamburg in 1892, these Berkefeld filters were used successfully.One form of diatomaceous earth is used as a filter medium, especially for swimming pools. It has a high porosity because it is composed of microscopically small, hollow particles. Diatomaceous earth (sometimes referre...
Abrasive
The oldest use of diatomite is as a very mild abrasive and has been used in toothpaste, metal polishes, and some facial scrubs.
Tripolite is the variety found in Tripoli, Libya.Bann clay is the variety found in the Lower Bannvalley in Northern Ireland.Moler (mo-clay) is the variety found in northwestern Denmark, especially on the islands of Fur and Mors.Freshwater-derived food grade diatomaceous earth is the type used in United States agriculture for grain storage, as feed supplement, and as an insecticide. It is produced uncalcinated, has a very...Certain species of bacteria in oceans and lakes can accelerate the rate of dissolution of silica in dead and living diatoms by using hydrolyticenzymes to break down the organic algal material.
The Earth's climate is affected by dust in the atmosphere, so locating major sources of atmospheric dust is important for climatology. Recent research indicates that surface deposits of diatomaceous earth play an important role. Research shows that significant dust comes from the Bodélé Depression in Chad, where storms push diatomite gravel over du...
Inhalation of crystalline silica is harmful to the lungs, causing silicosis. Amorphous silica is considered to have low toxicity, but prolonged inhalation causes changes to the lungs. Diatomaceous earth is mostly amorphous silica but contains some crystalline silica, especially in the saltwater forms. In a 1978 study of workers, those exposed to na...
Warren Edward Buffett (/ˈbʌfɪt/ BUF-it; born August 30, 1930)[2] is an American businessman, investor, and philanthropist who currently serves as the co-founder, chairman and CEO of Berkshire Hathaway. As a result of his investment success, Buffett is one of the best-known investors in the world. As of April 2024, he had a net worth of $139 ...
Following the scientific revelations of the mid-20th century, tobacco was condemned as a health hazard, and eventually became recognized as a cause of cancer, as well as other respiratory and circulatory diseases. In the United States, this led to the adoption of the 1998 Tobacco Master Settlement Agreement, which settled the many lawsuits by the U.S. states in exchange for a combination of ...
High-performance liquid chromatography ( HPLC ), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify specific components in mixtures.
