|
Zinc Cadmium Sulfide
Zinc cadmium sulfide is a mixture of zinc sulfide (ZnS) and cadmium sulfide (CdS). It is used for its fluorescent properties. Bioaccumulation of this chemical may occur along the food chain, for example in plants and in seafood. Long-term or repeated exposures are expected to have harmful effects on the kidneys, bones, and respiratory tract, resulting in kidney impairment, osteoporosis (bone weakness), and chronic inflammation of the respiratory tract. Use Operation LAC (Large Area Coverage) was a United States Army Chemical Corps operation in 1957 and 1958 which dispersed microscopic zinc cadmium sulfide (ZnCdS) particles over much of the United States. The purpose was to determine the dispersion and geographic range of biological or chemical agents. Zinc cadmium sulfide was used as it could be easily detected. It was also used in an experiment on unwitting civilians in the UK and Canada. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Sulfide
Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparency and translucency, transparent, and it is used as a window for visible light, visible optics and infrared optics. Structure ZnS exists in two main crystalline forms. This dualism is an example of polymorphism (materials science), polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically.. The transition from the sphalerite form to the wurtzite form occurs at around 1020 °C. Applications Luminescent mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadmium Sulfide
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow salt.Egon Wiberg, Arnold Frederick Holleman (2001''Inorganic Chemistry'' Elsevier It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium. As a compound that is easy to isolate and purify, it is the principal source of cadmium for all commercial applications. Its vivid yellow color led to its adoption as a pigment for the yellow paint "cadmium yellow" in the 1800s. Production Cadmium sulfide can be prepared by the precipitation from soluble cadmium(II) salts with sulfide ion. This reaction has been used for gravimetric analysis and qualitative inorganic analysis.The preparative route and the subsequent treatment of the product, affects the polymorphic form that is produced (i.e., c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops. This difference in duration is a result of quantum spin effects. Fluorescence occurs when a photon from incoming radiation is absorbed by a molecule, exciting it to a higher energy level, followed by the emission of light as the molecule returns to a lower energy state. The emitted light may have a longer wavelength and, therefore, a lower photon energy than the absorbed radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioaccumulation
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism. Toxicity induced by metals is associated with bioaccumulation and biomagnification. Storage or uptake of a metal faster than it is metabolized and excreted leads to the accumulation of that metal. The presence of various chemicals and harmful substances in the environment can be analyzed and assessed with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation LAC
Operation LAC (Large Area Coverage) was a United States Army Chemical Corps operation which dispersed microscopic zinc cadmium sulfide (ZnCdS) particles over much of the United States and Canada in order to test dispersal patterns and the geographic range of chemical or biological weapons. Earlier tests There were several tests that occurred prior to the first spraying affiliated with Operation LAC that proved the concept of large-area coverage. Canadian files relating to participation in the tests cite in particular three previous series of tests leading up to those conducted in Operation LAC. * September 1950 – Six simulated attacks were conducted upon the San Francisco Bay Area. It was concluded that it was feasible to attack a seaport city with biological aerosol agents from a ship offshore. * March–April 1952 – Five trials were conducted off the coast of South Carolina and Georgia under Operation Dew. It was concluded that long-range aerosol clouds could obtain hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army
The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United States Constitution (1789).See alsTitle 10, Subtitle B, Chapter 301, Section 3001 It operates under the authority, direction, and control of the United States Secretary of Defense, United States secretary of defense. It is one of the six armed forces and one of the eight uniformed services of the United States. The Army is the most senior branch in order of precedence amongst the armed services. It has its roots in the Continental Army, formed on 14 June 1775 to fight against the British for independence during the American Revolutionary War (1775–1783). After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.Library of CongressJournals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Corps
The Chemical Corps is the branch of the United States Army tasked with defending against and using chemical, biological, radiological, and nuclear ( CBRN) weapons. The Chemical Warfare Service was established on 28 June 1918, combining activities that until then had been dispersed among five separate agencies of the United States federal government. It was made a permanent branch of the Regular Army by the National Defense Act of 1920. In 1945, it was redesignated the Chemical Corps. History Origins Discussion of the topic dates back to the American Civil War. A letter to the War Department dated 5 April 1862 from New York City resident John Doughty proposed the use of chlorine shells to drive the Confederate Army from its positions. Doughty included a detailed drawing of the shell with his letter. It is unknown how the military reacted to Doughty's proposal but the letter was unnoticed in a pile of old official documents until modern times. Another American, Forrest Shephe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonard A
Leonard or ''Leo'' is a common English masculine given name and a surname. The given name and surname originate from the Old High German '' Leonhard'' containing the prefix ''levon'' ("lion") from the Greek Λέων ("lion") through the Latin '' Leo,'' and the suffix ''hardu'' ("brave" or "hardy"). The name has come to mean "lion strength", "lion-strong", or "lion-hearted". Leonard was the name of a Saint in the Middle Ages period, known as the patron saint of prisoners. Leonard is also an Irish origin surname, from the Gaelic ''O'Leannain'' also found as O'Leonard, but often was anglicised to just Leonard, consisting of the prefix ''O'' ("descendant of") and the suffix ''Leannan'' ("lover"). The oldest public records of the surname appear in 1272 in Huntingdonshire, England, and in 1479 in Ulm, Germany. Variations The name has variants in other languages: * Anard/Nardu/Lewnardu/Leunardu (Maltese) * Leen, Leendert, Lenard (Dutch) * Lehnertz, Lehnert (Luxembourgish) * Len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Dew
Operation Dew refers to two separate field trials conducted by the United States in the 1950s. The tests were designed to study the behavior of aerosol-released biological agents. General description Operation Dew took place from 1951 to 1952 off the southeast coast of the United States, including near Georgia, and North and South Carolina. Operation Dew consisted of two sets of trials, Dew I and Dew II. The tests involved the release of 250 pounds (110 kg) of fluorescent particles from a minesweeper off the coast. Operation Dew I was described in a U.S. Army report known as "Dugway Special Report 162", dated August 1, 1952. The purpose of Operation Dew was to study the behavior of aerosol-released biological agents.Croddy, Eric, et al. ''Chemical and Biological Warfare: A Comprehensive Survey for the Concerned Citizen'',Google Books, Springer, 2002, p. 231, (). Dew I Operation Dew I consisted of five separate trials from March 26, 1952, until April 21, 1952, that were design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project SHAD
Project SHAD, an acronym for Shipboard Hazard and Defense, was part of a larger effort called Project 112, which was conducted during the 1960s. Project SHAD encompassed tests designed to identify U.S. warships' vulnerabilities to attacks with chemical agents or biological warfare agents and to develop procedures to respond to such attacks while maintaining a war-fighting capability. History Project SHAD was part of a larger effort by the Department of Defense called Project 112. Project 112 was a chemical and biological weapons research, development, and testing project conducted by the United States Department of Defense and CIA handled by the Deseret Test Center and United States Army Chemical Materials Agency from 1962 to 1973. The project started under John F. Kennedy's administration, and was authorized by his Secretary of Defense Robert McNamara, as part of a total review of the US military. The name of the project refers to its number in the 150 review process. Mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unethical Human Experimentation In The United States
Numerous experiments which were performed on human test subjects in the United States in the past are now considered to have been unethical, because they were performed without the knowledge or informed consent of the test subjects. Such tests have been performed throughout American history, but have become significantly less frequent with the advent and adoption of various safeguarding efforts. Despite these safeguards, unethical experimentation involving human subjects is still occasionally uncovered. Past examples of unethical experiments include the exposure of humans to chemical and biological weapons (including infections with deadly or debilitating diseases), human radiation experiments, injections of toxic and radioactive chemicals, surgical experiments, interrogation and torture experiments, tests which involve mind-altering substances, and a wide variety of other experiments. Many of these tests are performed on children, the sick, and mentally disabled individuals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
