1.
Cryonics
–
Cryopreservation of humans is not reversible with present technology, cryonicists hope that medical advances will someday allow cryopreserved people to be revived. Cryonics is regarded with skepticism within the scientific community and is not part of normal medical practice. It is not known if it ever be possible to revive a cryopreserved human being. Cryonics depends on beliefs that the patient has not experienced information-theoretic death. Such views are at the edge of medicine. Cryonics procedures can only begin after legal death, and cryonics patients are considered legally dead, Cryonics procedures ideally begin within minutes of cardiac arrest, and use cryoprotectants to prevent ice formation during cryopreservation. The first corpse to be cryopreserved was that of Dr. James Bedford in 1967, as of 2014, about 250 bodies were cryopreserved in the United States, and 1,500 people had made arrangements for cryopreservation after their legal death. Long-term memory is stored in cell structures and molecules within the brain, the metabolic rate can be reduced by around 50% at 28 °C, and by around 80% at 18 °C or profound hypothermia. Cryonics goes further than the consensus that the brain doesnt have to be continuously active to survive or retain memory. Cryonicists argue that as long as brain structure remains intact, there is no barrier, given our current understanding of physical law. Cryonicists argue that death should be defined as irreversible loss of brain information critical to personal identity. Cryonics uses temperatures below −130°C, called cryopreservation, in an attempt to preserve enough brain information to permit future revival of the cryopreserved person, cryopreservation may be accomplished by freezing, freezing with cryoprotectant to reduce ice damage, or by vitrification to avoid ice damage. Even using the best methods, cryopreservation of whole bodies or brains is very damaging, Cryonics requires future technology to repair or regenerate tissue that is diseased, damaged, or missing. Brain repairs in particular will require analysis at the molecular level and this far-future technology is usually assumed to be nanomedicine based on molecular nanotechnology. Biological repair methods or mind uploading have also been proposed, as of 2011, U. S. cryopreservation costs can range from $28,000 to $200,000, and are often financed via life insurance. KrioRus, which stores bodies communally in large dewars, charges $12,000 to $36,000 for the procedure, some patients opt to have only their head, rather than their whole body, cryopreserved. As of 2016, four facilities exist in the world to retain cryopreserved bodies, as of 2014, about 250 people have been cryogenically preserved in the U. S. and around 1,500 more have signed up to be preserved. Long-term preservation of tissue can be achieved by cooling to temperatures below −130°C
Cryonics
–
Technicians prepare a legally dead patient for cryopreservation.
2.
James Webb Space Telescope
–
The James Webb Space Telescope, previously known as Next Generation Space Telescope, is a part of NASAs ongoing Flagship program. It is under construction and scheduled to launch in October 2018, the JWST will offer unprecedented resolution and sensitivity from long-wavelength visible light, through near-infrared to the mid-infrared. While the Hubble Space Telescope has a 2. 4-meter mirror, a large sunshield will keep its mirror and four science instruments below 50 K. JWSTs capabilities will enable a broad range of investigations across the fields of astronomy and cosmology. One particular goal involves observing some of the most distant events and objects in the Universe and these types of targets are beyond the reach of current ground and space-based instruments. Another goal is understanding the formation of stars and planets and this will include direct imaging of exoplanets. In gestation since 1996, the project represents a collaboration of the European Space Agency, Canadian Space Agency. It is named after James E. Webb, the administrator of NASA. NASA has described JWST as the successor of the Hubble Space Telescope. JWST has the objective to see objects, typically both older and farther away than previous instruments could assess. The result was to extend the life of Hubble until JWST as the next generation telescope could go online. This led to an altered design for JWST to obtain images deeper into the infrared than Hubble. The JWST originated in 1996 as the Next Generation Space Telescope, in 2002 it was renamed after NASAs second administrator James E. Webb, noted for playing a key role in the Apollo program and establishing scientific research as a core NASA activity. The telescope has a mass about half of Hubble Space Telescopes. The JWST is oriented toward near-infrared astronomy, but can also see orange and red light, as well as the mid-infrared region. The JWST will operate near the Earth-Sun L2 point, approximately 930,000 mi beyond the Earth, by way of comparison, Hubble orbits 340 miles above Earths surface, and the Moon is roughly 250,000 miles from Earth. This distance makes post-launch repair or upgrade of the JWST hardware virtually impossible and this will keep the temperature of the spacecraft below 50 K, necessary for infrared observations. The prime contractor is Northrop Grumman and its nominal mission time is five years, with a goal of ten years. JWST needs to use propellant to maintain its orbit around L2, which provides an upper limit to its designed lifetime
James Webb Space Telescope
–
Full-scale James Webb Space Telescope model at South by Southwest in Austin
James Webb Space Telescope
–
Two alternate
Hubble Space Telescope views of the
Carina Nebula, comparing visible (top) and infrared (bottom) astronomy
James Webb Space Telescope
–
Infrared observations can see objects hidden in visible light,
HUDF-JD2 shown
James Webb Space Telescope
–
JWST will not be exactly at the L2 point, but circle around it in a
halo orbit.
3.
Physics
–
Physics is the natural science that involves the study of matter and its motion and behavior through space and time, along with related concepts such as energy and force. One of the most fundamental disciplines, the main goal of physics is to understand how the universe behaves. Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy, Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the mechanisms of other sciences while opening new avenues of research in areas such as mathematics. Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs, the United Nations named 2005 the World Year of Physics. Astronomy is the oldest of the natural sciences, the stars and planets were often a target of worship, believed to represent their gods. While the explanations for these phenomena were often unscientific and lacking in evidence, according to Asger Aaboe, the origins of Western astronomy can be found in Mesopotamia, and all Western efforts in the exact sciences are descended from late Babylonian astronomy. The most notable innovations were in the field of optics and vision, which came from the works of many scientists like Ibn Sahl, Al-Kindi, Ibn al-Haytham, Al-Farisi and Avicenna. The most notable work was The Book of Optics, written by Ibn Al-Haitham, in which he was not only the first to disprove the ancient Greek idea about vision, but also came up with a new theory. In the book, he was also the first to study the phenomenon of the pinhole camera, many later European scholars and fellow polymaths, from Robert Grosseteste and Leonardo da Vinci to René Descartes, Johannes Kepler and Isaac Newton, were in his debt. Indeed, the influence of Ibn al-Haythams Optics ranks alongside that of Newtons work of the same title, the translation of The Book of Optics had a huge impact on Europe. From it, later European scholars were able to build the devices as what Ibn al-Haytham did. From this, such important things as eyeglasses, magnifying glasses, telescopes, Physics became a separate science when early modern Europeans used experimental and quantitative methods to discover what are now considered to be the laws of physics. Newton also developed calculus, the study of change, which provided new mathematical methods for solving physical problems. The discovery of new laws in thermodynamics, chemistry, and electromagnetics resulted from greater research efforts during the Industrial Revolution as energy needs increased, however, inaccuracies in classical mechanics for very small objects and very high velocities led to the development of modern physics in the 20th century. Modern physics began in the early 20th century with the work of Max Planck in quantum theory, both of these theories came about due to inaccuracies in classical mechanics in certain situations. Quantum mechanics would come to be pioneered by Werner Heisenberg, Erwin Schrödinger, from this early work, and work in related fields, the Standard Model of particle physics was derived. Areas of mathematics in general are important to this field, such as the study of probabilities, in many ways, physics stems from ancient Greek philosophy
Physics
–
Further information:
Outline of physics
Physics
–
Ancient
Egyptian astronomy is evident in monuments like the
ceiling of Senemut's tomb from the
Eighteenth Dynasty of Egypt.
Physics
–
Sir Isaac Newton (1643–1727), whose
laws of motion and
universal gravitation were major milestones in classical physics
Physics
–
Albert Einstein (1879–1955), whose work on the
photoelectric effect and the
theory of relativity led to a revolution in 20th century physics
4.
Temperatures
–
A temperature is an objective comparative measurement of hot or cold. It is measured by a thermometer, several scales and units exist for measuring temperature, the most common being Celsius, Fahrenheit, and, especially in science, Kelvin. Absolute zero is denoted as 0 K on the Kelvin scale, −273.15 °C on the Celsius scale, the kinetic theory offers a valuable but limited account of the behavior of the materials of macroscopic bodies, especially of fluids. Temperature is important in all fields of science including physics, geology, chemistry, atmospheric sciences, medicine. The Celsius scale is used for temperature measurements in most of the world. Because of the 100 degree interval, it is called a centigrade scale.15, the United States commonly uses the Fahrenheit scale, on which water freezes at 32°F and boils at 212°F at sea-level atmospheric pressure. Many scientific measurements use the Kelvin temperature scale, named in honor of the Scottish physicist who first defined it and it is a thermodynamic or absolute temperature scale. Its zero point, 0K, is defined to coincide with the coldest physically-possible temperature and its degrees are defined through thermodynamics. The temperature of zero occurs at 0K = −273. 15°C. For historical reasons, the triple point temperature of water is fixed at 273.16 units of the measurement increment, Temperature is one of the principal quantities in the study of thermodynamics. There is a variety of kinds of temperature scale and it may be convenient to classify them as empirically and theoretically based. Empirical temperature scales are historically older, while theoretically based scales arose in the middle of the nineteenth century, empirically based temperature scales rely directly on measurements of simple physical properties of materials. For example, the length of a column of mercury, confined in a capillary tube, is dependent largely on temperature. Such scales are only within convenient ranges of temperature. For example, above the point of mercury, a mercury-in-glass thermometer is impracticable. A material is of no use as a thermometer near one of its phase-change temperatures, in spite of these restrictions, most generally used practical thermometers are of the empirically based kind. Especially, it was used for calorimetry, which contributed greatly to the discovery of thermodynamics, nevertheless, empirical thermometry has serious drawbacks when judged as a basis for theoretical physics. Theoretically based temperature scales are based directly on theoretical arguments, especially those of thermodynamics, kinetic theory and they rely on theoretical properties of idealized devices and materials
Temperatures
–
Annual mean temperature around the world
Temperatures
–
Body temperature variation
Temperatures
–
A typical Celsius thermometer measures a winter day temperature of -17 °C.
Temperatures
–
Plots of pressure vs temperature for three different gas samples extrapolated to absolute zero.
5.
Refrigeration
–
Refrigeration is a process of moving heat from one location to another in controlled conditions. The work of heat transport is driven by mechanical work. Refrigeration has many applications, including, but not limited to, household refrigerators, industrial freezers, cryogenics, heat pumps may use the heat output of the refrigeration process, and also may be designed to be reversible, but are otherwise similar to air conditioning units. Refrigeration has had a impact on industry, lifestyle, agriculture. The idea of preserving food dates back to at least the ancient Roman, however, mechanical refrigeration technology has rapidly evolved in the last century, from ice harvesting to temperature-controlled rail cars. Settlements were also developing in parts of the country, filled with new natural resources. These new settlement patterns sparked the building of cities which are able to thrive in areas that were otherwise thought to be inhospitable, such as Houston, Texas and Las Vegas. In most developed countries, cities are heavily dependent upon refrigeration in supermarkets, the increase in food sources has led to a larger concentration of agricultural sales coming from a smaller percentage of existing farms. Farms today have a larger output per person in comparison to the late 1800s. This has resulted in new food sources available to entire populations, the seasonal harvesting of snow and ice is an ancient practice estimated to have begun earlier than 1000 B. C. A Chinese collection of lyrics from this period known as the Shih king. However, little is known about the construction of these ice cellars or what the ice was used for. ”Historians have interpreted this to mean that the Jews used ice to cool beverages rather than to preserve food. Other ancient cultures such as the Greeks and the Romans dug large snow pits insulated with grass, chaff, like the Jews, the Greeks and Romans did not use ice and snow to preserve food, but primarily as a means to cool beverages. Slaves would moisten the outside of the jars and the resulting evaporation would cool the water, the ancient people of India used this same concept to produce ice. The Persians stored ice in a pit called a Yakhchal and may have been the first group of people to use storage to preserve food. In the Australian outback before a reliable electricity supply was available where the weather could be hot and dry and this consisted of a room with hessian curtains hanging from the ceiling soaked in water. The water would evaporate and thereby cool the hessian curtains and thereby the air circulating in the room and this would allow many perishables such as fruit, butter, and cured meats to be kept that would normally spoil in the heat. Before 1830, few Americans used ice to refrigerate foods due to a lack of ice-storehouses and iceboxes, as these two things became more widely available, individuals used axes and saws to harvest ice for their storehouses
Refrigeration
–
Commercial refrigeration
Refrigeration
–
Ice harvesting in
Massachusetts, 1852, showing the
railroad line in the background, used to transport the ice.
Refrigeration
–
William Cullen, the first to conduct experiments into artificial refrigeration.
Refrigeration
–
Ferdinand Carré 's ice-making device
6.
Celsius
–
Celsius, also known as centigrade, is a metric scale and unit of measurement for temperature. As an SI derived unit, it is used by most countries in the world and it is named after the Swedish astronomer Anders Celsius, who developed a similar temperature scale. The degree Celsius can refer to a temperature on the Celsius scale as well as a unit to indicate a temperature interval. Before being renamed to honour Anders Celsius in 1948, the unit was called centigrade, from the Latin centum, which means 100, and gradus, which means steps. The scale is based on 0° for the point of water. This scale is widely taught in schools today, by international agreement the unit degree Celsius and the Celsius scale are currently defined by two different temperatures, absolute zero, and the triple point of VSMOW. This definition also precisely relates the Celsius scale to the Kelvin scale, absolute zero, the lowest temperature possible, is defined as being precisely 0 K and −273.15 °C. The temperature of the point of water is defined as precisely 273.16 K at 611.657 pascals pressure. This definition fixes the magnitude of both the degree Celsius and the kelvin as precisely 1 part in 273.16 of the difference between absolute zero and the point of water. Thus, it sets the magnitude of one degree Celsius and that of one kelvin as exactly the same, additionally, it establishes the difference between the two scales null points as being precisely 273.15 degrees. In his paper Observations of two persistent degrees on a thermometer, he recounted his experiments showing that the point of ice is essentially unaffected by pressure. He also determined with precision how the boiling point of water varied as a function of atmospheric pressure. He proposed that the point of his temperature scale, being the boiling point. This pressure is known as one standard atmosphere, the BIPMs 10th General Conference on Weights and Measures later defined one standard atmosphere to equal precisely 1013250dynes per square centimetre. On 19 May 1743 he published the design of a mercury thermometer, in 1744, coincident with the death of Anders Celsius, the Swedish botanist Carolus Linnaeus reversed Celsiuss scale. In it, Linnaeus recounted the temperatures inside the orangery at the University of Uppsala Botanical Garden, since the 19th century, the scientific and thermometry communities worldwide referred to this scale as the centigrade scale. Temperatures on the scale were often reported simply as degrees or. More properly, what was defined as centigrade then would now be hectograde.2 gradians, for scientific use, Celsius is the term usually used, with centigrade otherwise continuing to be in common but decreasing use, especially in informal contexts in English-speaking countries
Celsius
–
A
thermometer calibrated in degrees Celsius
7.
Kelvin
–
The kelvin is a unit of measure for temperature based upon an absolute scale. It is one of the seven units in the International System of Units and is assigned the unit symbol K. The kelvin is defined as the fraction 1⁄273.16 of the temperature of the triple point of water. In other words, it is defined such that the point of water is exactly 273.16 K. The Kelvin scale is named after the Belfast-born, Glasgow University engineer and physicist William Lord Kelvin, unlike the degree Fahrenheit and degree Celsius, the kelvin is not referred to or typeset as a degree. The kelvin is the unit of temperature measurement in the physical sciences, but is often used in conjunction with the Celsius degree. The definition implies that absolute zero is equivalent to −273.15 °C, Kelvin calculated that absolute zero was equivalent to −273 °C on the air thermometers of the time. This absolute scale is known today as the Kelvin thermodynamic temperature scale, when spelled out or spoken, the unit is pluralised using the same grammatical rules as for other SI units such as the volt or ohm. When reference is made to the Kelvin scale, the word kelvin—which is normally a noun—functions adjectivally to modify the noun scale and is capitalized, as with most other SI unit symbols there is a space between the numeric value and the kelvin symbol. Before the 13th CGPM in 1967–1968, the unit kelvin was called a degree and it was distinguished from the other scales with either the adjective suffix Kelvin or with absolute and its symbol was °K. The latter term, which was the official name from 1948 until 1954, was ambiguous since it could also be interpreted as referring to the Rankine scale. Before the 13th CGPM, the form was degrees absolute. The 13th CGPM changed the name to simply kelvin. Its measured value was 0.01028 °C with an uncertainty of 60 µK, the use of SI prefixed forms of the degree Celsius to express a temperature interval has not been widely adopted. In 2005 the CIPM embarked on a program to redefine the kelvin using a more experimentally rigorous methodology, the current definition as of 2016 is unsatisfactory for temperatures below 20 K and above 1300 K. In particular, the committee proposed redefining the kelvin such that Boltzmanns constant takes the exact value 1. 3806505×10−23 J/K, from a scientific point of view, this will link temperature to the rest of SI and result in a stable definition that is independent of any particular substance. From a practical point of view, the redefinition will pass unnoticed, the kelvin is often used in the measure of the colour temperature of light sources. Colour temperature is based upon the principle that a black body radiator emits light whose colour depends on the temperature of the radiator, black bodies with temperatures below about 4000 K appear reddish, whereas those above about 7500 K appear bluish
Kelvin
–
Lord Kelvin, the namesake of the unit
Kelvin
–
A thermometer calibrated in degrees Celsius (left) and kelvins (right).
8.
Fahrenheit
–
Fahrenheit is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit, after whom the scale is named. It uses the degree Fahrenheit as the unit, several accounts of how he originally defined his scale exist. The lower defining point,0 °F, was established as the temperature of a solution of brine made from parts of ice. Further limits were established as the point of ice and his best estimate of the average human body temperature. All other countries in the world now use the Celsius scale, defined since 1954 by absolute zero being −273.15 °C, on the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit and the boiling point is 212 °F. This puts the boiling and freezing points of water exactly 180 degrees apart, therefore, a degree on the Fahrenheit scale is 1⁄180 of the interval between the freezing point and the boiling point. On the Celsius scale, the freezing and boiling points of water are 100 degrees apart, a temperature interval of 1 °F is equal to an interval of 5⁄9 degrees Celsius. The Fahrenheit and Celsius scales intersect at −40°, absolute zero is −273.15 °C or −459.67 °F. For an exact conversion, the formulas can be applied. Again, f is the value in Fahrenheit and c the value in Celsius, f °Fahrenheit to c °Celsius, C °Celsius to f °Fahrenheit, −40 = f. Fahrenheit proposed his temperature scale in 1724, basing it on two points of temperature. In his initial scale, the point is determined by placing the thermometer in a mixture of ice, water. This is a mixture which stabilizes its temperature automatically, that stable temperature was defined as 0 °F. The second point,96 degrees, was approximately the human bodys temperature, in any case, the definition of the Fahrenheit scale has changed since. According to a letter Fahrenheit wrote to his friend Herman Boerhaave, his scale was built on the work of Ole Rømer, whom he had met earlier. In Rømers scale, brine freezes at zero, water freezes and melts at 7.5 degrees, body temperature is 22.5, Fahrenheit multiplied each value by four in order to eliminate fractions and increase the granularity of the scale. Fahrenheit observed that water boils at about 212 degrees using this scale, under this system, the Fahrenheit scale is redefined slightly so that the freezing point of water is exactly 32 °F, and the boiling point is exactly 212 °F or 180 degrees higher. It is for this reason that human body temperature is approximately 98° on the revised scale
Fahrenheit
–
Thermometer with Fahrenheit and Celsius units
Fahrenheit
–
Daniel Gabriel Fahrenheit
9.
National Institute of Standards and Technology
–
The National Institute of Standards and Technology is a measurement standards laboratory, and a non-regulatory agency of the United States Department of Commerce. Its mission is to promote innovation and industrial competitiveness, in 1821, John Quincy Adams had declared Weights and measures may be ranked among the necessities of life to every individual of human society. From 1830 until 1901, the role of overseeing weights and measures was carried out by the Office of Standard Weights and Measures, president Theodore Roosevelt appointed Samuel W. Stratton as the first director. The budget for the first year of operation was $40,000, a laboratory site was constructed in Washington, DC, and instruments were acquired from the national physical laboratories of Europe. In addition to weights and measures, the Bureau developed instruments for electrical units, in 1905 a meeting was called that would be the first National Conference on Weights and Measures. Quality standards were developed for products including some types of clothing, automobile brake systems and headlamps, antifreeze, during World War I, the Bureau worked on multiple problems related to war production, even operating its own facility to produce optical glass when European supplies were cut off. Between the wars, Harry Diamond of the Bureau developed a blind approach radio aircraft landing system, in 1948, financed by the Air Force, the Bureau began design and construction of SEAC, the Standards Eastern Automatic Computer. The computer went into operation in May 1950 using a combination of vacuum tubes, about the same time the Standards Western Automatic Computer, was built at the Los Angeles office of the NBS and used for research there. A mobile version, DYSEAC, was built for the Signal Corps in 1954, due to a changing mission, the National Bureau of Standards became the National Institute of Standards and Technology in 1988. Following 9/11, NIST conducted the investigation into the collapse of the World Trade Center buildings. NIST had a budget for fiscal year 2007 of about $843.3 million. NISTs 2009 budget was $992 million, and it also received $610 million as part of the American Recovery, NIST employs about 2,900 scientists, engineers, technicians, and support and administrative personnel. About 1,800 NIST associates complement the staff, in addition, NIST partners with 1,400 manufacturing specialists and staff at nearly 350 affiliated centers around the country. NIST publishes the Handbook 44 that provides the Specifications, tolerances, the Congress of 1866 made use of the metric system in commerce a legally protected activity through the passage of Metric Act of 1866. NIST is headquartered in Gaithersburg, Maryland, and operates a facility in Boulder, nISTs activities are organized into laboratory programs and extramural programs. Effective October 1,2010, NIST was realigned by reducing the number of NIST laboratory units from ten to six, nISTs Boulder laboratories are best known for NIST‑F1, which houses an atomic clock. NIST‑F1 serves as the source of the official time. NIST also operates a neutron science user facility, the NIST Center for Neutron Research, the NCNR provides scientists access to a variety of neutron scattering instruments, which they use in many research fields
National Institute of Standards and Technology
–
Chart of NBS activities, 1915.
National Institute of Standards and Technology
–
A spectrometer in use at the NBS in 1948.
National Institute of Standards and Technology
–
Advanced Measurement Laboratory Complex in Gaithersburg
National Institute of Standards and Technology
–
Boulder Laboratories
10.
Boiling point
–
The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the environmental pressure. A liquid in a vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high pressure has a boiling point than when that liquid is at atmospheric pressure. For a given pressure, different liquids boil at different temperatures, for example, water boils at 100 °C at sea level, but at 93.4 °C at 2,000 metres altitude. The normal boiling point of a liquid is the case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level,1 atmosphere. At that temperature, the pressure of the liquid becomes sufficient to overcome atmospheric pressure. The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of 1 bar, the heat of vaporization is the energy required to transform a given quantity of a substance from a liquid into a gas at a given pressure. Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation, evaporation is a surface phenomenon in which molecules located near the liquids edge, not contained by enough liquid pressure on that side, escape into the surroundings as vapor. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, a saturated liquid contains as much thermal energy as it can without boiling. The saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase, the liquid can be said to be saturated with thermal energy. Any addition of energy results in a phase transition. If the pressure in a system remains constant, a vapor at saturation temperature will begin to condense into its liquid phase as thermal energy is removed, similarly, a liquid at saturation temperature and pressure will boil into its vapor phase as additional thermal energy is applied. The boiling point corresponds to the temperature at which the pressure of the liquid equals the surrounding environmental pressure. Thus, the point is dependent on the pressure. Boiling points may be published with respect to the NIST, USA standard pressure of 101.325 kPa, at higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower. The boiling point increases with increased pressure up to the critical point, the boiling point cannot be increased beyond the critical point. Likewise, the point decreases with decreasing pressure until the triple point is reached
Boiling point
–
Boiling water
11.
Gas
–
Gas is one of the four fundamental states of matter. A pure gas may be made up of atoms, elemental molecules made from one type of atom. A gas mixture would contain a variety of pure gases much like the air, what distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer, the interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image. One type of commonly known gas is steam, the gaseous state of matter is found between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention, high-density atomic gases super cooled to incredibly low temperatures are classified by their statistical behavior as either a Bose gas or a Fermi gas. For a comprehensive listing of these states of matter see list of states of matter. The only chemical elements which are stable multi atom homonuclear molecules at temperature and pressure, are hydrogen, nitrogen and oxygen. These gases, when grouped together with the noble gases. Alternatively they are known as molecular gases to distinguish them from molecules that are also chemical compounds. The word gas is a neologism first used by the early 17th-century Flemish chemist J. B. van Helmont, according to Paracelsuss terminology, chaos meant something like ultra-rarefied water. An alternative story is that Van Helmonts word is corrupted from gahst and these four characteristics were repeatedly observed by scientists such as Robert Boyle, Jacques Charles, John Dalton, Joseph Gay-Lussac and Amedeo Avogadro for a variety of gases in various settings. Their detailed studies ultimately led to a relationship among these properties expressed by the ideal gas law. Gas particles are separated from one another, and consequently have weaker intermolecular bonds than liquids or solids. These intermolecular forces result from interactions between gas particles. Like-charged areas of different gas particles repel, while oppositely charged regions of different gas particles attract one another, transient, randomly induced charges exist across non-polar covalent bonds of molecules and electrostatic interactions caused by them are referred to as Van der Waals forces. The interaction of these forces varies within a substance which determines many of the physical properties unique to each gas. A comparison of boiling points for compounds formed by ionic and covalent bonds leads us to this conclusion, the drifting smoke particles in the image provides some insight into low pressure gas behavior
Gas
–
Drifting
smoke particles provide clues to the movement of the surrounding gas.
Gas
–
Gas phase particles (
atoms,
molecules, or
ions) move around freely in the absence of an applied
electric field.
Gas
–
Shuttle imagery of re-entry phase.
Gas
–
21 April 1990 eruption of
Mount Redoubt,
Alaska, illustrating real gases not in thermodynamic equilibrium.
12.
Helium
–
Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and its boiling point is the lowest among all the elements. Its abundance is similar to figure in the Sun and in Jupiter. This is due to the high nuclear binding energy 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 nuclear fusion and radioactive decay. Most helium in the universe is helium-4, and is believed to have formed during the Big Bang. Large amounts of new helium are being created by fusion of hydrogen in stars. Helium is named for the Greek god of the Sun, Helios and it was first detected as an unknown yellow spectral line signature in sunlight during a solar eclipse in 1868 by French astronomer Jules Janssen. Janssen is jointly credited with detecting the element along with Norman Lockyer, Janssen observed during the solar eclipse of 1868 while Lockyer observed from Britain. Lockyer was the first to propose that the line was due to a new element, the formal discovery of the element was made in 1895 by two Swedish chemists, Per Teodor Cleve and Nils Abraham Langlet, who found helium emanating from the uranium ore cleveite. In 1903, large reserves of helium were found in gas fields in parts of the United States. Liquid helium is used in cryogenics, particularly in the cooling of superconducting magnets, a well-known but minor use is as a lifting gas in balloons and airships. As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre, on Earth it is relatively rare—5.2 ppm by volume in the atmosphere. Most terrestrial helium present today is created by the radioactive decay of heavy radioactive elements. Previously, terrestrial helium—a non-renewable resource, because once released into the atmosphere it readily escapes into space—was thought to be in short supply. The first evidence of helium was observed on August 18,1868, the line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India. This line was assumed to be sodium. He concluded that it was caused by an element in the Sun unknown on Earth, Lockyer and English chemist Edward Frankland named the element with the Greek word for the Sun, ἥλιος
Helium
–
Helium, 2 He
Helium
–
Spectral lines of helium
Helium
Helium
–
Sir
William Ramsay, the discoverer of terrestrial helium
13.
Hydrogen
–
Hydrogen is a chemical element with chemical symbol H and atomic number 1. With a standard weight of circa 1.008, hydrogen is the lightest element on the periodic table. Its monatomic form is the most abundant chemical substance in the Universe, non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed protium, has one proton, the universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. Hydrogen plays an important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a charge when it is known as a hydride. The hydrogen cation is written as though composed of a bare proton, Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals. Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production, the two largest uses being fossil fuel processing and ammonia production, mostly for the fertilizer market, Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks. Hydrogen gas is flammable and will burn in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion is −286 kJ/mol,2 H2 + O2 →2 H2O +572 kJ Hydrogen gas forms explosive mixtures with air in concentrations from 4–74%, the explosive reactions may be triggered by spark, heat, or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C, the detection of a burning hydrogen leak may require a flame detector, such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames, the destruction of the Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated. The visible orange flames in that incident were the result of a mixture of hydrogen to oxygen combined with carbon compounds from the airship skin. H2 reacts with every oxidizing element, the ground state energy level of the electron in a hydrogen atom is −13.6 eV, which is equivalent to an ultraviolet photon of roughly 91 nm wavelength. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, however, the atomic electron and proton are held together by electromagnetic force, while planets and celestial objects are held by gravity. The most complicated treatments allow for the effects of special relativity
Hydrogen
–
Purple glow in its plasma state
Hydrogen
–
The
Space Shuttle Main Engine burnt hydrogen with oxygen, producing a nearly invisible flame at full thrust.
Hydrogen
–
Spectral lines of hydrogen
Hydrogen
–
First tracks observed in
liquid hydrogen bubble chamber at the
Bevatron
14.
Neon
–
Neon is a chemical element with symbol Ne and atomic number 10 and is a noble gas. Neon is a colorless, odorless, inert gas under standard conditions. It was discovered in 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide were removed. Neon was the second of three rare gases to be discovered, and was immediately recognized as a new element from its bright red emission spectrum. The name neon is derived from the Greek word, νέον, neuter singular form of νέος, Neon is chemically inert and forms no uncharged chemical compounds. The compounds of neon include ionic molecules, molecules held together by van der Waals forces and clathrates, during cosmic nucleogenesis of the elements, large amounts of neon are built up from the alpha-capture fusion process in stars. Although neon is a common element in the universe and solar system. It composes about 18.2 ppm of air by volume, the reason for neons relative scarcity on Earth and the inner planets is that neon is highly volatile and forms no compounds to fix it to solids. As a result, it escaped from the planetesimals under the warmth of the newly ignited Sun in the early Solar System, even the atmosphere of Jupiter is somewhat depleted of neon, presumably for this reason. It is also lighter than air, causing it to escape even from Earths atmosphere, Neon gives a distinct reddish-orange glow when used in low-voltage neon glow lamps, high-voltage discharge tubes and neon advertising signs. The red emission line from neon also causes the well known red light of helium–neon lasers, Neon is used in some plasma tube and refrigerant applications but has few other commercial uses. It is commercially extracted by the distillation of liquid air. Since air is the source, it is considerably more expensive than helium. Neon, was discovered in 1898 by the British chemists Sir William Ramsay, Neon was discovered when Ramsay chilled a sample of air until it became a liquid, then warmed the liquid and captured the gases as they boiled off. The gases nitrogen, oxygen, and argon had been identified, first to be identified was krypton. The next, after krypton had been removed, was a gas which gave a brilliant red light under spectroscopic discharge and this gas, identified in June, was named neon, the Greek analogue of novum, suggested by Ramsays son. A second gas was reported along with neon, having approximately the same density as argon but with a different spectrum – Ramsay. However, subsequent spectroscopic analysis revealed it to be contaminated with carbon monoxide
Neon
–
Neon, 10 Ne
Neon
–
Spectral lines of neon in the visible region
Neon
–
Neon
gas-discharge lamps forming the symbol for neon "Ne"
Neon
–
The first evidence for isotopes of a stable element was provided in 1913 by experiments on neon plasma. In the bottom right corner of
J. J. Thomson 's photographic plate are the separate impact marks for the two isotopes neon-20 and neon-22.
15.
Nitrogen
–
Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772, although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. Nitrogen is the lightest member of group 15 of the periodic table, the name comes from the Greek πνίγειν to choke, directly referencing nitrogens asphyxiating properties. It is an element in the universe, estimated at about seventh in total abundance in the Milky Way. At standard temperature and pressure, two atoms of the element bind to form dinitrogen, a colourless and odorless diatomic gas with the formula N2, dinitrogen forms about 78% of Earths atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids, in the nucleic acids, the human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, many industrially important compounds, such as ammonia, nitric acid, organic nitrates, and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen, the second strongest bond in any diatomic molecule. Synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems. Apart from its use in fertilisers and energy-stores, nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric, Nitrogen is a constituent of every major pharmacological drug class, including antibiotics. Many notable nitrogen-containing drugs, such as the caffeine and morphine or the synthetic amphetamines. Nitrogen compounds have a long history, ammonium chloride having been known to Herodotus. They were well known by the Middle Ages, alchemists knew nitric acid as aqua fortis, as well as other nitrogen compounds such as ammonium salts and nitrate salts. The mixture of nitric and hydrochloric acids was known as aqua regia, celebrated for its ability to dissolve gold, the discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it noxious air. Though he did not recognise it as a different chemical substance, he clearly distinguished it from Joseph Blacks fixed air. The fact that there was a component of air that does not support combustion was clear to Rutherford, Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as burnt air or phlogisticated air. Nitrogen gas was inert enough that Antoine Lavoisier referred to it as air or azote, from the Greek word άζωτικός. In an atmosphere of nitrogen, animals died and flames were extinguished
Nitrogen
–
Liquid nitrogen
Nitrogen
–
Spectral lines of nitrogen
Nitrogen
–
Nitrogen discharge (spectrum) tube
Nitrogen
–
Table tennis ball made from nitrocellulose.
16.
Oxygen
–
Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the group on the periodic table and is a highly reactive nonmetal. By mass, oxygen is the third-most abundant element in the universe, after hydrogen, at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20. 8% of the Earths atmosphere, additionally, as oxides the element makes up almost half of the Earths crust. Most of the mass of living organisms is oxygen as a component of water, conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone, strongly absorbs ultraviolet UVB radiation, but ozone is a pollutant near the surface where it is a by-product of smog. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft, the name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle, Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philos work by observing that a portion of air is consumed during combustion and respiration, Oxygen was discovered by the Polish alchemist Sendivogius, who considered it the philosophers stone. In the late 17th century, Robert Boyle proved that air is necessary for combustion, English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. From this he surmised that nitroaereus is consumed in both respiration and combustion, Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract De respiratione. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, one part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the combustion products
Oxygen
–
Spectral lines of oxygen
Oxygen
Oxygen
–
A trickle of liquid oxygen is deflected by a magnetic field, illustrating its paramagnetic property
Oxygen
–
Oxygen discharge (spectrum) tube. The green color is similar to the color of an
"aurora borealis"
17.
Cryobiology
–
Cryobiology is the branch of biology that studies the effects of low temperatures on living things within Earths cryosphere or in science. The word cryobiology is derived from the Greek words κρῧος, « cold », βίος, « life », 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, temperatures may range from moderately hypothermic conditions to cryogenic temperatures. Most living organisms accumulate cryoprotectants such as antinucleating proteins, polyols, most plants, in particular, can safely reach temperatures of −4 °C to −12 °C. Three species of bacteria, Carnobacterium pleistocenium, Chryseobacterium greenlandensis. the freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria. Listeria grows slowly in temperatures as low as -1.5 °C, many plants undergo a process called hardening which allows them to survive temperatures below 0 °C for weeks to months. Nematodes that survive below 0 °C include Trichostrongylus colubriformis and Panagrolaimus davidi, cockroach nymphs survive short periods of freezing at -6 to -8 °C. The red flat bark beetle can survive after being frozen to -150 °C, the fungus gnat Exechia nugatoria can survive after being frozen to -50 °C, by a unique mechanism whereby ice crystals form in the body but not the head. Another freeze-tolerant beetle is Upis ceramboides, see insect winter ecology and antifreeze protein. Another invertebrate that is tolerant to temperatures down to -273 °C is the tardigrade. The larvae of Haemonchus contortus, a nematode, can survive 44 weeks frozen at -196 °C, for the wood frog, in the winter, as much as 45% of its body may freeze and turn to ice. Ice crystals form beneath the skin and become interspersed among the bodys skeletal muscles, during the freeze, the frogs breathing, blood flow, and heartbeat cease. Freezing is made possible by specialized proteins and glucose, which prevent intracellular freezing, the wood frog can survive up to 11 days frozen at -4 °C. Antifreeze proteins cloned from such fish have been used to confer frost-resistance on transgenic plants, Cryobiology history can be traced back to antiquity. As early as in 2500 BC, low temperatures were used in Egypt in medicine, the use of cold was recommended by Hippocrates to stop bleeding and swelling. With the emergence of science, Robert Boyle studied the effects of low temperatures on animals. In 1949, bull semen was cryopreserved for the first time by a team of scientists led by Christopher Polge and this led to a much wider use of cryopreservation today, with many organs, tissues and cells routinely stored at low temperatures. Large organs such as hearts are usually stored and transported, for short times only, at cool, cell suspensions and thin tissue sections can sometimes be stored almost indefinitely in liquid nitrogen temperature
Cryobiology
–
Boyle
18.
Biology
–
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, identification and taxonomy. Modern biology is a vast and eclectic field, composed of branches and subdisciplines. However, despite the broad scope of biology, there are certain unifying concepts within it that consolidate it into single, coherent field. In general, biology recognizes the cell as the unit of life, genes as the basic unit of heredity. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable, the term biology is derived from the Greek word βίος, bios, life and the suffix -λογία, -logia, study of. The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica, the first German use, Biologie, was in a 1771 translation of Linnaeus work. In 1797, Theodor Georg August Roose used the term in the preface of a book, karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological, physiological and psychological perspective. The science that concerns itself with these objects we will indicate by the biology or the doctrine of life. Although modern biology is a recent development, sciences related to. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, Egypt, the Indian subcontinent, however, the origins of modern biology and its approach to the study of nature are most often traced back to ancient Greece. While the formal study of medicine back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Especially important are his History of Animals and other works where he showed naturalist leanings, and later more empirical works that focused on biological causation and the diversity of life. Aristotles successor at the Lyceum, Theophrastus, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences, even into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, biology began to quickly develop and grow with Anton van Leeuwenhoeks dramatic improvement of the microscope. It was then that scholars discovered spermatozoa, bacteria, infusoria, investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy also had a impact on biological thinking. In the early 19th century, a number of biologists pointed to the importance of the cell. Thanks to the work of Robert Remak and Rudolf Virchow, however, meanwhile, taxonomy and classification became the focus of natural historians
Biology
Biology
Biology
Biology
19.
Organism
–
In biology, an organism is any contiguous living system, such as an animal, plant, fungus, protist, archaeon, or bacterium. All known types of organisms are capable of some degree of response to stimuli, reproduction, growth and development and homeostasis. An organism consists of one or more cells, when it has one cell it is known as an organism. Most unicellular organisms are of microscopic scale and are thus described as microorganisms. Humans are multicellular organisms composed of trillions of cells grouped into specialized tissues. An organism may be either a prokaryote or a eukaryote, prokaryotes are represented by two separate domains—bacteria and archaea. Eukaryotic organisms are characterized by the presence of a cell nucleus. Fungi, animals and plants are examples of kingdoms of organisms within the eukaryotes, estimates on the number of Earths current species range from 10 million to 14 million, of which only about 1.2 million have been documented. More than 99% of all species, amounting to five billion species. In 2016, a set of 355 genes from the last universal ancestor of all living organisms living was identified. The term organism first appeared in the English language in 1703 and it is directly related to the term organization. There is a tradition of defining organisms as self-organizing beings. An organism may be defined as an assembly of molecules functioning as a more or less stable whole that exhibits the properties of life. Dictionary definitions can be broad, using such as any living structure, such as a plant, animal, fungus or bacterium, capable of growth. Many definitions exclude viruses and possible man-made non-organic life forms, as viruses are dependent on the machinery of a host cell for reproduction. A superorganism is an organism consisting of individuals working together as a single functional or social unit. There has been controversy about the best way to define the organism, several contributions are responses to the suggestion that the category of organism may well not be adequate in biology. Viruses are not typically considered to be organisms because they are incapable of autonomous reproduction and this controversy is problematic because some cellular organisms are also incapable of independent survival and live as obligatory intracellular parasites
Organism
–
These
Escherichia coli cells provide an example of a
prokaryotic microorganism.
Organism
–
A
polypore mushroom has a
parasitic relationship with its
host.
Organism
–
An
ericoid mycorrhizal fungus
Organism
20.
Cryopreservation
–
At low enough temperatures, any 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 during freezing, traditional cryopreservation has relied on coating the material to be frozen with a class of molecules termed cryoprotectants. New methods are constantly being investigated due to the inherent toxicity of many cryoprotectants, by default it should be considered that cryopreservation alters or compromises the structure and function of cells unless it is proven otherwise for a particular cell population. Cryoconservation of animal genetic resources is the process in which genetic material is collected and stored with the intention of conservation of the breed. Mixtures of solutes can achieve similar effects, some solutes, including salts, have the disadvantage that they may be toxic at intense concentrations. In addition to the water-bear, wood frogs can tolerate the freezing of their blood, urea is accumulated in tissues in preparation for overwintering, and liver glycogen is converted in large quantities to glucose in response to internal ice formation. Both urea and glucose act as cryoprotectants to limit the amount of ice that forms, frogs can survive many freeze/thaw events during winter if not more than about 65% of the total body water freezes. Research exploring the phenomenon of Freezing frogs has been performed primarily by the Canadian researcher, snapping turtles Chelydra serpentina and wall lizards Podarcis muralis also survive nominal freezing but it has not been established to be adaptive for overwintering. In the case of Rana sylvatica one cryopreservant is ordinary glucose, one of the most important early theoreticians of cryopreservation was James Lovelock known for Gaia theory. He suggested that damage to red blood cells during freezing was due to osmotic stress, during the early 1950s, Lovelock had also suggested that increasing salt concentrations in a cell as it dehydrates to lose water to the external ice might cause damage to the cell. Cryopreservation of tissue during recent times began with the freezing of fowl sperm, the process was applied to humans during the 1950s with pregnancies obtained after insemination of frozen sperm. Increased understanding of the mechanism of freezing injury to cells emphasised the importance of controlled or slow cooling to obtain maximum survival on thawing of the living cells, the ability of cryoprotectants, in the early cases glycerol, to protect cells from freezing injury was discovered accidentally. Freezing injury has two aspects, direct damage from the ice crystals and secondary damage caused by the increase in concentration of solutes as progressively more ice is formed. Storage at very cold temperatures is presumed to provide an indefinite longevity to cells, researchers experimenting with dried seeds found that there was noticeable variability of deterioration when samples were kept at different temperatures – even ultra-cold temperatures. Many of these effects can be reduced by cryoprotectants, once the preserved material has become frozen, it is relatively safe from further damage. However, estimates based on the accumulation of radiation-induced DNA damage during cryonic storage have suggested a maximum period of 1000 years. Solution effects As ice crystals grow in freezing water, solutes are excluded, high concentrations of some solutes can be very damaging. Extracellular ice formation When tissues are cooled slowly, water migrates out of cells, too much extracellular ice can cause mechanical damage to the cell membrane due to crushing
Cryopreservation
–
Cryopreservation of plant shoots. Open tank of liquid nitrogen behind.
Cryopreservation
–
A tank of
liquid nitrogen, used to supply a cryonic freezer (for storing laboratory samples at a temperature of about −150 °C)
Cryopreservation
–
Four different
ecotypes of
Physcomitrella patens stored at the
IMSC.
21.
Cryosurgery
–
Cryosurgery is the use of extreme cold in surgery to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning hand work or handiwork, Cryosurgery has been historically used to treat a number of diseases and disorders, especially a variety of benign and malignant skin conditions. Warts, moles, skin tags, solar keratoses, Mortons neuroma, several internal disorders are also treated with cryosurgery, including liver cancer, prostate cancer, lung cancer, oral cancers, cervical disorders and, more commonly in the past, hemorrhoids. Soft tissue conditions such as plantar fasciitis and fibroma can be treated with cryosurgery, generally, all tumors that can be reached by the cryoprobes used during an operation are treatable. Although found to be effective, this method of treatment is appropriate for use against localized disease. Tiny, diffuse metastases that often coincide with cancers are not affected by cryotherapy. Cryosurgery works by taking advantage of the force of freezing temperatures on cells. When their temperature sinks beyond a certain level ice crystals begin forming inside the cells and, because of their lower density, further harm to malignant growth will result once the blood vessels supplying the affected tissue begin to freeze. A common method of freezing lesions is using liquid nitrogen as the cooling solution and this −196 °C cold liquid may be sprayed on the diseased tissue, circulated through a tube called a cryoprobe, or simply dabbed on with a cotton or foam swab. Carbon dioxide is available as a spray and is used to treat a variety of benign spots. Less frequently, doctors use carbon dioxide snow formed into a cylinder or mixed with acetone to form a slush that is applied directly to the treated tissue. Recent advances in technology have allowed for the use of gas to drive ice formation using a principle known as the Joule-Thomson effect. This gives physicians excellent control of the ice, and minimizing complications using ultra-thin 17 gauge cryoneedles, a mixture of dimethyl ether and propane is used in some preparations such as Dr. Scholls Freeze Away. The mixture is stored in an aerosol spray type container at room temperature, the mixture is often dispensed into a straw with a cotton-tipped swab. A number of medical supply companies have developed cryogen delivery systems for cryosurgery, most are based on the use of liquid nitrogen, although some employ the use of proprietary mixtures of gases that combine to form the cryogen. Some commonly used products are, Brymill Cry-Ac Cryoalfa CryoClear CryoPen CryoPro, Cortex Technology CryoProbe Cryosurgery. To cure internal tumors, an instrument called a cryoprobe is used. Liquid nitrogen or Argon gas is passed through the cryoprobe, ultrasound or MRI is used to guide the cryoprobe and monitor the freezing of the cells
Cryosurgery
–
Cryogun used to spray liquid nitrogen
22.
Superconductivity
–
It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8,1911, in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a mechanical phenomenon. It is characterized by the Meissner effect, the ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be simply as the idealization of perfect conductivity in classical physics. The electrical resistance of a metallic conductor decreases gradually as temperature is lowered, in ordinary conductors, such as copper or silver, this decrease is limited by impurities and other defects. Even near absolute zero, a sample of a normal conductor shows some resistance. In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature, an electric current flowing through a loop of superconducting wire can persist indefinitely with no power source. In 1986, it was discovered that some cuprate-perovskite ceramic materials have a temperature above 90 K. Such a high temperature is theoretically impossible for a conventional superconductor. There are many criteria by which superconductors are classified, by theory of operation, It is conventional if it can be explained by the BCS theory or its derivatives, or unconventional, otherwise. By material, Superconductor material classes include chemical elements, alloys, ceramics, on the other hand, there is a class of properties that are independent of the underlying material. For instance, all superconductors have exactly zero resistivity to low applied currents when there is no magnetic field present or if the field does not exceed a critical value. The resistance of the sample is given by Ohms law as R = V / I, if the voltage is zero, this means that the resistance is zero. Superconductors are also able to maintain a current with no applied voltage whatsoever, experiments have demonstrated that currents in superconducting coils can persist for years without any measurable degradation. Experimental evidence points to a current lifetime of at least 100,000 years, theoretical estimates for the lifetime of a persistent current can exceed the estimated lifetime of the universe, depending on the wire geometry and the temperature. In a normal conductor, an electric current may be visualized as a fluid of electrons moving across an ionic lattice. As a result, the energy carried by the current is constantly being dissipated and this is the phenomenon of electrical resistance and Joule heating. The situation is different in a superconductor, in a conventional superconductor, the electronic fluid cannot be resolved into individual electrons
Superconductivity
–
A
magnet levitating above a
high-temperature superconductor, cooled with
liquid nitrogen. Persistent electric current flows on the surface of the superconductor, acting to exclude the magnetic field of the magnet (
Faraday's law of induction). This current effectively forms an electromagnet that repels the magnet.
Superconductivity
–
A high-temperature superconductor levitating above a magnet
Superconductivity
–
Electric cables for accelerators at
CERN. Both the massive and slim cables are rated for 12,500
A. Top: conventional cables for
LEP; bottom: superconductor-based cables for the
LHC
Superconductivity
–
Heike Kamerlingh Onnes (right), the discoverer of superconductivity.
Paul Ehrenfest,
Hendrik Lorentz,
Niels Bohr stand to his left.
23.
Greek language
–
Greek is an independent branch of the Indo-European family of languages, native to Greece and other parts of the Eastern Mediterranean. It has the longest documented history of any living language, spanning 34 centuries of written records and its writing system has been the Greek alphabet for the major part of its history, other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic and many other writing systems. Together with the Latin texts and traditions of the Roman world, during antiquity, Greek was a widely spoken lingua franca in the Mediterranean world and many places beyond. It would eventually become the official parlance of the Byzantine Empire, the language is spoken by at least 13.2 million people today in Greece, Cyprus, Italy, Albania, Turkey, and the Greek diaspora. Greek roots are used to coin new words for other languages, Greek. Greek has been spoken in the Balkan peninsula since around the 3rd millennium BC, the earliest written evidence is a Linear B clay tablet found in Messenia that dates to between 1450 and 1350 BC, making Greek the worlds oldest recorded living language. Among the Indo-European languages, its date of earliest written attestation is matched only by the now extinct Anatolian languages, the Greek language is conventionally divided into the following periods, Proto-Greek, the unrecorded but assumed last ancestor of all known varieties of Greek. The unity of Proto-Greek would have ended as Hellenic migrants entered the Greek peninsula sometime in the Neolithic era or the Bronze Age, Mycenaean Greek, the language of the Mycenaean civilisation. It is recorded in the Linear B script on tablets dating from the 15th century BC onwards, Ancient Greek, in its various dialects, the language of the Archaic and Classical periods of the ancient Greek civilisation. It was widely known throughout the Roman Empire, after the Roman conquest of Greece, an unofficial bilingualism of Greek and Latin was established in the city of Rome and Koine Greek became a first or second language in the Roman Empire. The origin of Christianity can also be traced through Koine Greek, Medieval Greek, also known as Byzantine Greek, the continuation of Koine Greek in Byzantine Greece, up to the demise of the Byzantine Empire in the 15th century. Much of the written Greek that was used as the language of the Byzantine Empire was an eclectic middle-ground variety based on the tradition of written Koine. Modern Greek, Stemming from Medieval Greek, Modern Greek usages can be traced in the Byzantine period and it is the language used by the modern Greeks, and, apart from Standard Modern Greek, there are several dialects of it. In the modern era, the Greek language entered a state of diglossia, the historical unity and continuing identity between the various stages of the Greek language is often emphasised. Greek speakers today still tend to regard literary works of ancient Greek as part of their own rather than a foreign language and it is also often stated that the historical changes have been relatively slight compared with some other languages. According to one estimation, Homeric Greek is probably closer to demotic than 12-century Middle English is to modern spoken English, Greek is spoken by about 13 million people, mainly in Greece, Albania and Cyprus, but also worldwide by the large Greek diaspora. Greek is the language of Greece, where it is spoken by almost the entire population
Greek language
–
Idealized portrayal of
Homer
Greek language
–
regions where Greek is the official language
Greek language
–
Greek language road sign, A27 Motorway, Greece
24.
Liquid nitrogen
–
Liquid nitrogen is nitrogen in a liquid state at an extremely low temperature. It is a clear liquid with a density of 0.807 g/ml at its boiling point. Nitrogen was first liquefied at the Jagiellonian University on 15 April 1883 by Polish physicists, Zygmunt Wróblewski and it is produced industrially by fractional distillation of liquid air. Liquid nitrogen is often referred to by the abbreviation, LN2 or LIN or LN and has the UN number 1977, Liquid nitrogen is a diatomic liquid, which means that the diatomic character of the covalent N bonding in N2 gas is retained after liquefaction. Liquid nitrogen is a fluid that can cause rapid freezing on contact with living tissue. When appropriately insulated from ambient heat, liquid nitrogen can be stored and transported, the temperature is held constant at 77 K by slow boiling of the liquid, resulting in the evolution of nitrogen gas. Depending on the size and design, the time of vacuum flasks ranges from a few hours to a few weeks. The development of pressurised super-insulated vacuum vessels has enabled liquefied nitrogen to be stored and transported over longer periods with losses reduced to 2% per day or less. The temperature of liquid nitrogen can readily be reduced to its freezing point 63 K by placing it in a vacuum chamber pumped by a vacuum pump. Liquid nitrogens efficiency as a coolant is limited by the fact that it immediately on contact with a warmer object. This effect, known as the Leidenfrost effect, applies to any liquid in contact with an object significantly hotter than its boiling point, faster cooling may be obtained by plunging an object into a slush of liquid and solid nitrogen rather than liquid nitrogen alone. Liquid nitrogen is a compact and readily transported source of dry nitrogen gas, as it not require pressurization. g. As an energy storage medium branding cattle The culinary use of nitrogen is mentioned in an 1890 recipe book titled Fancy Ices authored by Mrs. The rapidity of chilling also leads to the formation of ice crystals. The technique is employed by chef Heston Blumenthal who has used it at his restaurant, The Fat Duck to create frozen dishes such as egg, Liquid nitrogen has also become popular in the preparation of cocktails because it can be used to quickly chill glasses or freeze ingredients. It is also added to drinks to create a smoky effect, because the liquid-to-gas expansion ratio of nitrogen is 1,694 at 20 °C, a tremendous amount of force can be generated if liquid nitrogen is rapidly vaporized in an enclosed space. In an incident on January 12,2006 at Texas A&M University, as a result of the subsequent pressure buildup, the tank failed catastrophically. Because of its low temperature, careless handling of liquid nitrogen
Liquid nitrogen
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Liquid nitrogen
Liquid nitrogen
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Students preparing homemade
ice cream with liquid nitrogen.
Liquid nitrogen
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Filling a liquid nitrogen
Dewar from a storage tank
25.
Liquid helium
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At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C. Its boiling point and critical point depend on which isotope of helium is present and these are the only two stable isotopes of helium. See the table below for the values of physical quantities. The density of liquid helium-4 at its point and a pressure of one atmosphere is about 0.125 grams per cm3. Helium was first liquefied on July 10,1908, by the Dutch physicist Heike Kamerlingh Onnes at the University of Leiden in the Netherlands, at that time, helium-3 was unknown because the mass spectrometer had not yet been invented. The temperature required to produce liquid helium is low because of the weakness of the attractions between the helium atoms. These interatomic forces in helium are weak to begin with because helium is a noble gas and these are significant in helium because of its low atomic mass of about four atomic mass units. The zero point energy of helium is less if its atoms are less confined by their neighbors. Hence in liquid helium, its ground state energy can decrease by a naturally occurring increase in its average interatomic distance, however at greater distances, the effects of the interatomic forces in helium are even weaker. Because of the very weak interatomic forces in helium, this element would remain a liquid at atmospheric pressure all the way from its liquefaction point down to absolute zero, liquid helium solidifies only under very low temperatures and great pressures. At temperatures below their liquefaction points, both helium-4 and helium-3 undergo transitions to superfluids, liquid helium-4 and the rare helium-3 are not completely miscible. Below 0.9 kelvin at their saturated vapor pressure, a mixture of the two isotopes undergoes a separation into a normal fluid that floats on a denser superfluid consisting mostly of helium-4. This phase separation happens because the mass of liquid helium can reduce its thermodynamic enthalpy by separating. At extremely low temperatures, the phase, rich in helium-4. This makes possible the use of the dilution refrigerator, which is capable of reaching temperatures of a few millikelvins. Superfluid helium-4 has substantially different properties from ordinary liquid helium, general He-3 and He-4 phase diagrams, etc. Onness liquifaction of helium Kamerlingh Onness 1908 article, online and analyzed on BibNum
Liquid helium
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Liquid helium (in a vacuum bottle) at 4.2 K and 1 atm, boiling slowly.
Liquid helium
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Liquid helium cooled below the
Lambda point, where it exhibits properties of
superfluidity
Liquid helium
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Lambda point transition: as the liquid is cooled down through 2.17 K, the boiling suddenly becomes violent for a moment.
Liquid helium
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Superfluid phase at temperature below 2.17 K. In this state, the thermal conductivity is extremely large. This causes heat in the body of the liquid to be transferred to its surface so quickly that vaporization takes place only at the free surface of the liquid. Thus, there are no gas bubbles in the body of the liquid.
26.
Dewar flask
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A vacuum flask is an insulating storage vessel that greatly lengthens the time over which its contents remain hotter or cooler than the flasks surroundings. Invented by Sir James Dewar in 1892, the vacuum consists of two flasks, placed one within the other and joined at the neck. The gap between the two flasks is partially evacuated of air, creating a near-vacuum which significantly reduces heat transfer by conduction or convection, Vacuum flasks are used domestically to keep beverages hot or cold for extended periods of time and for many purposes in industry. The vacuum flask was designed and invented by Scottish scientist Sir James Dewar in 1892 as a result of his research in the field of cryogenics and is called a Dewar flask in his honour. He evacuated the air between the two creating a partial vacuum to keep the temperature of the contents stable. Through the need for this insulated container James Dewar created the vacuum flask, the flask was later developed using new materials such as glass and aluminum, however, Dewar refused to patent his invention. Prior to Dewars invention, German chemist and physician Adolf Ferdinand Weinhold invented his own version of a flask in 1881. Dewars design was transformed into a commercial item in 1904 as two German glassblowers discovered that it could be used to keep cold drinks cold and warm drinks warm. The name later became a trademark after the term thermos became the household name for such a liquid container. The vacuum flask went on to be used for different types of scientific experiments. Thermos remains a trademark in some countries but was declared a genericized trademark in the US in 1963 since it is colloquially synonymous with vacuum flasks in general. However, there are other vacuum flasks, after the German glassblowers determined the commercial uses for the Dewar flask, the technology was sold to the Thermos company who used it to mass-produce vacuum flasks for at-home use. Eventually other manufacturers produced similar products for consumer use, the vacuum flask consists of two flasks, placed one within the other and joined at the neck. The gap between the two flasks is partially evacuated of air, creating a partial-vacuum which reduces heat conduction or convection, most heat transfer occurs through the neck and opening of the flask, where there is no vacuum. Vacuum flasks are made of metal, borosilicate glass, foam or plastic and have their opening stoppered with cork or polyethylene plastic. Vacuum flasks are used as insulated shipping containers. Extremely large or long vacuum flasks sometimes cannot fully support the inner flask from the neck alone and these spacers act as a thermal bridge and partially reduce the insulating properties of the flask around the area where the spacer contacts the interior surface. Several technological applications, such as NMR and MRI machines, rely on the use of vacuum flasks
Dewar flask
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The typical design of a Thermos brand vacuum flask, used for maintaining the temperature of fluids such as
coffee.
Dewar flask
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Laboratory Dewar flask,
Deutsches Museum, Munich
Dewar flask
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A
cryogenic storage dewar of
liquid nitrogen, used to supply a
cryogenic freezer
Dewar flask
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From Weinhold 1881 described vacuum flask
27.
James Dewar
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Sir James Dewar FRS FRSE was a Scottish chemist and physicist. He is probably best known today for his invention of the vacuum flask and he was also particularly interested in atomic and molecular spectroscopy, working in these fields for more than 25 years. James Dewar was born in Kincardine, Perthshire in 1842, the youngest of six boys of Thomas Dewar, a vintner, James was educated at Kincardine Parish School and then Dollar Academy. He lost his parents when he was 15, soon leaving the Academy. There he studied chemistry under Lyon Playfair and became Playfairs personal assistant, Dewar also studied under August Kekulé at Ghent. In 1875, Dewar was elected Jacksonian professor of experimental philosophy at the University of Cambridge. He became a member of the Royal Institution and later, in 1877, whilst he was serving on the Committee on Explosives, Frederick Augustus Abel and he developed cordite, a smokeless gunpowder alternative. In 1867 Dewar described several chemical formulas for benzene, ironically, one of the formulae, which does not represent benzene correctly and was not advocated by Dewar, is sometimes still called Dewar benzene. In 1869 he was elected a Fellow of the Royal Society of Edinburgh, his proposer being his former mentor, Lyon Playfair. With professor J. G. McKendrick, of Glasgow, he investigated the physiological action of light, with professor G. D. A. Fleming, of University College London, in the investigation of the electrical behaviour of substances cooled to very low temperatures. His name is most widely known in connection with his work on the liquefaction of the permanent gases. His interest in this branch of physics and chemistry dates back at least as far as 1874, about 1892, the idea occurred to him of using vacuum-jacketed vessels for the storage of liquid gases – the Dewar flask – the invention for which he became most famous. The vacuum flask was so efficient at keeping heat out, it was possible to preserve the liquids for comparatively long periods. Dewar did not profit from the adoption of his vacuum flask – he lost a court case against Thermos concerning the patent for his invention. While Dewar was recognised as the inventor, because he did not patent his invention, using this machine in 1898, liquid hydrogen was collected for the first time, solid hydrogen following in 1899. Dewar continued his work into the properties of elements at low temperatures, specifically low-temperature calorimetry. Shortages of scholars necessarily compounded the problems and his research during and after the war mainly involved investigating surface tension in soap bubbles, rather than further work into the properties of matter at low temperatures. James Dewar died at the Royal Institution in London in 1923, still holding the office of Fullerian Professor of Chemistry at the Royal Institution and he was cremated at the Golders Green Crematorium, where his ashes remain
James Dewar
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Sir James Dewar FRS
James Dewar
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Sir James Dewar at work
James Dewar
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James Dewar's vacuum flask in the museum of the
Royal Institution
James Dewar
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Portrait by
René le Brun, Comte de L'Hôpital, in the collection of the
Royal Society of Chemistry
