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Malcolm Dole
Malcolm Dole (March 4, 1903 – November 29, 1990) was an American chemist known for the Dole Effect in which he proved that the atomic weight of oxygen in air is greater than that of oxygen in water and for his work on electrospray ionization, polymer chemistry, and electrochemistry. Dole effect The Dole effect is the inequality in the ratio of heavy oxygen isotope 18O to the more abundant 16O in the earth's atmosphere and in seawater. This effect was reported by Dole in 1935. The effect is due to slightly different reaction rates for the two isotopes in respiration in plants and in animals which tends to retain the lighter 16O, which increases the relative concentration of 18O in the atmosphere. Electrospray Electrospray is a process in which a high voltage is applied to a liquid to create an aerosol containing highly charged droplets. Dole in 1968 was the first to use electrospray ionization Electrospray ionization (ESI) is a technique used in mass spectrometry to p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melrose, Massachusetts
Melrose is a city located in the Greater Boston metropolitan area in Middlesex County, Massachusetts, United States. Its population, per the 2020 United States Census, is 29,817. It is a suburb located approximately seven miles north of Boston. It is situated in the center of the triangle created by Interstates 93, 95 and U.S. Route 1. The land that comprises Melrose was first settled in 1628 and was once part of Charlestown and then Malden. It became the Town of Melrose in 1850 and then the City of Melrose in 1900. History Melrose was originally called "Ponde Fielde" for its abundance of ponds and streams or "Mystic Side" because of its location in a valley north of the Mystic River. The area was first explored by Richard and Ralph Sprague in 1628 and became part of Charlestown in 1633 along with a large area of land encompassing most of the surrounding communities. City of Melrose. Retrieved on January 26, 2008 In 1649, the neighborhood of Charlestown known as Malden wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Americans
Americans are the Citizenship of the United States, citizens and United States nationality law, nationals of the United States, United States of America.; ; Although direct citizens and nationals make up the majority of Americans, many Multiple citizenship, dual citizens, expatriates, and green card, permanent residents could also legally claim American nationality. The United States is home to race and ethnicity in the United States, people of many racial and ethnic origins; consequently, culture of the United States, American culture and Law of the United States, law do not equate nationality with Race (human categorization), race or Ethnic group, ethnicity, but with citizenship and an Oath of Allegiance (United States), oath of permanent allegiance. Overview The majority of Americans or their ancestors Immigration to the United States, immigrated to the United States or are descended from people who were Trans Atlantic Slave Trade, brought as Slavery in the United States ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1990 Deaths
Year 199 ( CXCIX) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was sometimes known as year 952 '' Ab urbe condita''. The denomination 199 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Mesopotamia is partitioned into two Roman provinces divided by the Euphrates, Mesopotamia and Osroene. * Emperor Septimius Severus lays siege to the city-state Hatra in Central-Mesopotamia, but fails to capture the city despite breaching the walls. * Two new legions, I Parthica and III Parthica, are formed as a permanent garrison. China * Battle of Yijing: Chinese warlord Yuan Shao defeats Gongsun Zan. Korea * Geodeung succeeds Suro of Geumgwan Gaya, as king of the Korean kingdom of Gaya (traditional date). By topic Religion * Pope Zephyrinus succeeds Pope Victor I, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1903 Births
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipknot. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Chemical Physics
''The Journal of Chemical Physics'' is a scientific journal published by the American Institute of Physics that carries research papers on chemical physics."About the Journal" from the ''Journal of Chemical Physics'' website. Two volumes, each of 24 issues, are published annually. It was established in 1933 when '''' editors refused to publish theoretical works. The editors have been: *2019-present: Tim Lian *2008–2018: *2007–2008: [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be natural or Human impact on the environment, anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of anthropogenic aerosols include particulate air pollutants, mist from the discharge at Hydroelectric dam, hydroelectric dams, Irrigation, irrigation mist, Perfume, perfume from atomizers, smoke, steam from a kettle, Pesticide, sprayed pesticides, and medical treatments for respiratory illnesses. When a person inhales the contents of a vape pen or e-cigarette, they are inhaling an Human impact on the environment, anthropogenic aerosol. The liquid or solid particles in an aerosol have diameters typically less than micrometre, 1 μm (larger particles with a significant settling speed make the mixture a Suspension (chemistry), suspension, but the distinction is not clear-cut) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrospray
The name electrospray is used for an apparatus that employs electricity to disperse a liquid or for the fine aerosol resulting from this process. High voltage is applied to a liquid supplied through an emitter (usually a glass or metallic capillary). Ideally the liquid reaching the emitter tip forms a Taylor cone, which emits a liquid jet through its apex. Varicose waves on the surface of the jet lead to the formation of small and highly charged liquid droplets, which are radially dispersed due to Coulomb repulsion. History In the late 16th century William GilbertGilbert, W. (1628) De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth), London, Peter Short set out to describe the behaviour of magnetic and electrostatic phenomena. He observed that, in the presence of a charged piece of amber, a drop of water deformed into a cone. This effect is clearly related to electrosprays, even though Gilbert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiration (physiology)
In physiology, respiration is the movement of oxygen from the outside environment to the cells within Tissue (biology), tissues, and the transport, removal of carbon dioxide in the opposite direction that's to the environment. The physiological definition of respiration differs from the Cellular respiration, biochemical definition, which refers to a metabolic process by which an organism obtains energy (in the form of ATP and NADPH) by oxidizing nutrients and releasing waste products. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the Diffusion#Diffusion vs. bulk flow diffusion, diffusion and transport of metabolites between the organism and the external environment. Gas exchanges in the lung occurs by ventilation and perfusion. Ventilation refers to the in and out movement of air of the lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Respiration
Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, releasing energy. Respiration is one of the key ways a cell releases chemical energy to fuel cellular activity. The overall reaction occurs in a series of biochemical steps, some of which are redox reactions. Although cellular respiration is technically a combustion reaction, it is an unusual one because of the slow, controlled release of energy from the series of reactions. Nutrients that are commonly used by animal and plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, the solar wind, and cosmic rays to protect organisms from genetic damage. The current comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen-18
Oxygen-18 (, Ω) is a natural, stable isotope of oxygen and one of the environmental isotopes. is an important precursor for the production of fluorodeoxyglucose (FDG) used in positron emission tomography (PET). Generally, in the radiopharmaceutical industry, enriched water () is bombarded with hydrogen ions in either a cyclotron or linear accelerator, creating fluorine-18. This is then synthesized into FDG and injected into a patient. It can also be used to make an extremely heavy version of water when combined with tritium (hydrogen-3): or . This compound has a density almost 30% greater than that of natural water. The accurate measurements of rely on proper procedures of analysis, sample preparation and storage. Paleoclimatology In ice cores, mainly Arctic and Antarctic, the ratio of to (known as δ) can be used to determine the temperature of precipitation through time. Assuming that atmospheric circulation and elevation has not changed significantly over the poles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei. While all isotopes of a given element have almost the same chemical properties, they have different atomic masses and physical properties. The term isotope is formed from the Greek roots isos ( ἴσος "equal") and topos ( τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. It was coined by Scottish doctor and writer Margaret Todd in 1913 in a suggestion to the British chemist Frederick Soddy. The number of protons within the atom's nucleus is called its atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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