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Cryogenics
In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th IIR International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of “cryogenics” and “cryogenic” by accepting a threshold of 120 K (or –153 °C) to distinguish these terms from the conventional refrigeration. This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below 120K while the Freon refrigerants, hydrocarbons, and other common refrigerants have boiling points above 120K. The U.S. National Institute of Standards and Technology considers the field of cryogenics as that involving temperatures below -153 Celsius (120K; -243.4 Fahrenheit) Discovery of superconducting materials with critical temperatures significantly above the boiling point of nitrogen has provided new interest in reliable, low cost method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Zero
Absolute zero is the lowest limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as zero kelvin. The fundamental particles of nature have minimum vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as −273.15 degrees on the Celsius scale (International System of Units), Note: The triple point of water is 0.01 °C, not 0 °C; thus 0 K is −2890.15 °C, not −273.16 °C. which equals −459.67 degrees on the Fahrenheit scale ( United States customary units or Imperial units). The corresponding Kelvin and Rankine temperature scales set their zero points at absolute zero by definition. It is commonly thought of as the lowest temperature possible, but it is not the lowest ''enthalpy'' state poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. It is the second lightest and second most abundant element in the observable universe (hydrogen is the lightest and most abundant). It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and in Jupiter, due to the very high nuclear binding energy (per nucleon) of helium-4, with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, the vast majority of which was formed during t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superconducting
Superconductivity is a set of physical properties observed in certain materials where Electrical resistance and conductance, electrical resistance vanishes and magnetic field, magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic electrical conductor, conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic Phase transition, critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source. The superconductivity phenomenon was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. Like ferromagnetism and atomic spectral lines, superconductivity is a phenomenon which can only be explained by quantum mechanics. It is characterized by the Meissner effect, the complete ejection of magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryobiology
Cryobiology is the branch of biology that studies the effects of low temperatures on living things within Earth's cryosphere or in science. The word cryobiology is derived from the Greek words κρῧος ryos "cold", βίος ios "life", and λόγος ogos "word". In practice, cryobiology is the study of biological material or systems at temperatures below normal. Materials or systems studied may include proteins, cells, tissues, organs, or whole organisms. Temperatures may range from moderately hypothermic conditions to cryogenic temperatures. Areas of study At least six major areas of cryobiology can be identified: 1) study of cold-adaptation of microorganisms, plants ( cold hardiness), and animals, both invertebrates and vertebrates (including hibernation), 2) cryopreservation of cells, tissues, gametes, and embryos of animal and human origin for (medical) purposes of long-term storage by cooling to temperatures below the freezing point of water. This usually requires the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryopreservation
Cryo-preservation or cryo-conservation is a process where Organism, organisms, organelles, cell (biology), cells, Biological tissue, tissues, extracellular matrix, Organ (anatomy), organs, or any other biological constructs susceptible to damage caused by unregulated chemical kinetics are preserved by cooling to very low temperatures (typically using solid carbon dioxide or using liquid nitrogen). At low enough temperatures, any Enzyme, enzymatic or chemical activity which might cause damage to the biological material in question is effectively stopped. Cryopreservation methods seek to reach low temperatures without causing additional damage caused by the formation of ice crystals during freezing. Traditional cryopreservation has relied on coating the material to be frozen with a class of molecules termed cryoprotectants. New methods are being investigated due to the inherent toxicity of many cryoprotectants. Cryoconservation of animal genetic resources is done with the intentio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infobase Publishing
Infobase Publishing is an American publisher of reference book titles and textbooks geared towards the North American library, secondary school, and university-level curriculum markets. Infobase operates a number of prominent imprints, including Facts On File, Films for the Humanities & Sciences, Cambridge Educational, Chelsea House (which also serves as the imprint for the special collection series, "Bloom's Literary Criticism" under the direction of literary critic Harold Bloom), and Ferguson Publishing. History The private equity firm Veronis Suhler Stevenson bought Facts on File and Chelsea House in 2005. Infobase bought Films for the Humanities & Sciences in 2007 and the ''World Almanac'' in 2009. In 2017, Infobase acquired The Mailbox lesson plans and ''Learning'' magazine. Veronis Suhler Stevenson sold Infobase to another private equity firm, Centre Lane Partners, in 2018. As well as nonfiction works in print, Infobase and its imprints publish a selection of works in di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rankine Scale
The Rankine scale () is an absolute scale of thermodynamic temperature named after the University of Glasgow engineer and physicist Macquorn Rankine, who proposed it in 1859. History Similar to the Kelvin scale, which was first proposed in 1848, zero on the Rankine scale is absolute zero, but a temperature difference of one Rankine degree (°R or °Ra) is defined as equal to one Fahrenheit degree, rather than the Celsius degree used on the Kelvin scale. In converting from kelvin to degrees Rankine, 1 °R = K or 1 K = 1.8 °R. A temperature of 0 K (−273.15 °C; −459.67 °F) is equal to 0 °R.B.8 Factors for Units Listed Alphabetically from Usage The Rankine scale is still used in engineering systems where hea ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celsius Scale
The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The degree Celsius (symbol: °C) can refer to a specific temperature on the Celsius scale or a unit to indicate a difference or range between two temperatures. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale in 1742. Before being renamed in 1948 to honour Anders Celsius, the unit was called ''centigrade'', from the Latin ''centum'', which means 100, and ''gradus'', which means steps. Most major countries use this scale; the other major scale, Fahrenheit, is still used in the United States, some island territories, and Liberia. The Kelvin scale is of use in the sciences, with representing absolute zero. Since 1743 the Celsius scale has been based on 0 °C for the freezing poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Don Rittner
Don Rittner is an American historian, archeologist, anthropologist, environmental activist, educator, author and film maker living in the Capital District, Schenectady County, New York. He is the former Schenectady County Historian, responsible for providing guidance and support to municipal historians and serving as a conduit between the State Historian in Albany and the local historians in their counties. He is also the former Schenectady City Historian and was the Albany City Archeologist (1973–79). He is the author of more than 50+ books on history, natural history, computers, and other subjects, and has been collected by libraries worldwide. Biography He attended the University of Albany where as a student he continued the earlier work of William B. Efner, a predecessor as County Historian.Don Rittner biography, Schenectady County In 1973 he became the archeologist for the city of Albany. He excavated old Colonial tavern sites and roads, and located the old King's Highway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state of New York. Located near the southern tip of New York State, Manhattan is based in the Eastern Time Zone and constitutes both the geographical and demographic center of the Northeast megalopolis and the urban core of the New York metropolitan area, the largest metropolitan area in the world by urban landmass. Over 58 million people live within 250 miles of Manhattan, which serves as New York City’s economic and administrative center, cultural identifier, and the city’s historical birthplace. Manhattan has been described as the cultural, financial, media, and entertainment capital of the world, is considered a safe haven for global real estate investors, and hosts the United Nations headquarters. New York City is the headquarters of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
