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Explosive Boiling
In physical chemistry, explosive boiling or phase explosion is a process in which a Superheating, superheated Metastability, metastable liquid undergoes an explosive liquid–vapor phase transition into a stable two-phase state because of a massive Nucleation#Homogeneous nucleation, homogeneous nucleation of vapor bubbles. This concept was pioneered by M. M. Martynyuk in 1976 and then later advanced by Fucke and Seydel. Mechanism Explosive boiling can be best described by a pressure–temperature (''p''–''T'') phase diagram. The figure on right shows a typical ''p''–''T'' phase diagram of a substance. The binodal line or the coexistence curve is a thermodynamic state where at that specific temperature and pressure, liquid and vapor can coexist. The spinodal line on right is the boundary of absolute instability of a solution to decomposition into multiple phases. A typical heating process is shown in red. If the heating process is relatively slow, the liquid has enough time to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Chemistry
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibria. Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a supra-molecular science, as the majority of the principles on which it was founded relate to the bulk rather than the molecular or atomic structure alone (for example, chemical equilibrium and colloids). Some of the relationships that physical chemistry strives to resolve include the effects of: # Intermolecular forces that act upon the physical properties of materials ( plasticity, tensile strength, surface tension in liquids). # Reaction kinetics on the rate of a reaction. # The identity of ions and the electrical conductivity of materials. # Surface science and electrochemistry of cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, San Diego
The University of California, San Diego (UC San Diego or colloquially, UCSD) is a public university, public Land-grant university, land-grant research university in San Diego, California. Established in 1960 near the pre-existing Scripps Institution of Oceanography, UC San Diego is the southernmost of the ten campuses of the University of California, and offers over 200 undergraduate and graduate degree programs, enrolling 33,096 undergraduate and 9,872 graduate students. The university occupies near the coast of the Pacific Ocean, with the main campus resting on approximately . UC San Diego is ranked among the best universities in the world by major college and university rankings. UC San Diego consists of twelve undergraduate, graduate and professional schools as well as seven undergraduate residential colleges. It received over 140,000 applications for undergraduate admissions in Fall 2021, making it the second most applied-to university in the United States. UC San Diego H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Phase Transition
Rapid phase transition or RPT is a phenomenon realized in liquefied natural gas (LNG) incidents in which LNG vaporizes violently upon coming in contact with water causing what is known as a ''physical explosion'' or ''cold explosion''. During such explosions there is no combustion but rather a huge amount of energy is transferred in the form of heat from the room-temperature water to the LNG at a temperature difference of about . LNG Properties Liquefied natural gas or LNG is a natural gas that gets liquefied at atmospheric pressure and −161.5 °C. It is odorless, tasteless, colorless, and not poisonous but causes asphyxia. It can cause frostbite due to its cryogenic temperature. If this extremely cold LNG is mixed with water(e.g. sea water Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Liquid Expanding Vapor Explosion
A boiling liquid expanding vapor explosion (BLEVE, ) is an explosion caused by the rupture of a vessel containing a pressurized liquid that has reached temperature above its boiling point. Because the boiling point of a liquid rises with pressure, the contents of the pressurized vessel can remain liquid as long as the vessel is intact. If the vessel's integrity is compromised, the loss of pressure and dropping boiling point can cause the liquid to rapidly convert to a gas and expand rapidly. If the gas is combustible, as is the case with hydrocarbons and alcohols, further damage can be caused by the ensuing fire. Mechanism There are three key elements causing a BLEVE: # A substance in liquid form at a temperature above its normal atmospheric pressure boiling point. # A containment vessel maintains the pressure that keeps the substance in liquid form. # A sudden loss of containment that rapidly drops the pressure. Typically, a BLEVE starts with a container of liqui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Ablation
Laser ablation or photoablation (also called laser blasting) is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates. At high laser flux, the material is typically converted to a plasma. Usually, laser ablation refers to removing material with a pulsed laser, but it is possible to ablate material with a continuous wave laser beam if the laser intensity is high enough. While relatively long laser pulses (e.g. nanosecond pulses) can heat and thermally alter or damage the processed material, ultrashort laser pulses (e.g. femtoseconds) cause only minimal material damage during processing due to the ultrashort light-matter interaction and are therefore also suitable for micromaterial processing. Excimer lasers of deep ultra-violet light are mainly used in photoablation; the wavelength of laser used in photoablation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleation
In thermodynamics, nucleation is the first step in the formation of either a new thermodynamic phase or structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically defined to be the process that determines how long an observer has to wait before the new phase or self-organized structure appears. For example, if a volume of water is cooled (at atmospheric pressure) below 0°C, it will tend to freeze into ice, but volumes of water cooled only a few degrees below 0°C often stay completely free of ice for long periods (supercooling). At these conditions, nucleation of ice is either slow or does not occur at all. However, at lower temperatures nucleation is fast, and ice crystals appear after little or no delay. Nucleation is a common mechanism which generates first-order phase transitions, and it is the start of the process of forming a new thermodynamic phase. In contrast, new phases at continuous phase transitions start to form im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropy
Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory. It has found far-ranging applications in chemistry and physics, in biological systems and their relation to life, in cosmology, economics, sociology, weather science, climate change, and information systems including the transmission of information in telecommunication. The thermodynamic concept was referred to by Scottish scientist and engineer William Rankine in 1850 with the names ''thermodynamic function'' and ''heat-potential''. In 1865, German physicist Rudolf Clausius, one of the leading founders of the field of thermodynamics, defined it as the quotient of an infinitesimal amount ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \rho = \frac where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate – this quantity is more specifically called specific weight. For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Heat Capacity
In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of heat that must be added to one unit of mass of the substance in order to cause an increase of one unit in temperature. The SI unit of specific heat capacity is joule per kelvin per kilogram, J⋅kg−1⋅K−1. For example, the heat required to raise the temperature of of water by is , so the specific heat capacity of water is . Specific heat capacity often varies with temperature, and is different for each state of matter. Liquid water has one of the highest specific heat capacities among common substances, about at 20 °C; but that of ice, just below 0 °C, is only . The specific heat capacities of iron, granite, and hydrogen gas are about 449 J⋅kg−1⋅K−1, 790 J⋅kg−1⋅K−1, and 14300 J⋅kg−1⋅K−1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Point (thermodynamics)
In thermodynamics, a critical point (or critical state) is the end point of a phase equilibrium curve. The most prominent example is the liquid–vapor critical point, the end point of the pressure–temperature curve that designates conditions under which a liquid and its vapor can coexist. At higher temperatures, the gas cannot be liquefied by pressure alone. At the critical point, defined by a ''critical temperature'' ''T''c and a ''critical pressure'' ''p''c, phase boundaries vanish. Other examples include the liquid–liquid critical points in mixtures, and the ferromagnet–paramagnet transition ( Curie temperature) in the absence of an external magnetic field. Liquid–vapor critical point Overview For simplicity and clarity, the generic notion of ''critical point'' is best introduced by discussing a specific example, the vapor–liquid critical point. This was the first critical point to be discovered, and it is still the best known and most studied one. The f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Point
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the surrounding environmental pressure. A liquid in a partial vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at low pressure has a lower boiling point than when that liquid is at atmospheric pressure. Because of this, water boils at under standard pressure at sea level, but at at altitude. For a given pressure, different liquids will boil at different temperatures. The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level, one atmosphere. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmosph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluctuation Of Thermodynamic Properties Near Critical Point , price fluctuation
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Fluctuation may refer to: Physics and mathematics * Statistical fluctuations, in statistics, statistical mechanics, and thermodynamics ** Thermal fluctuations, statistical fluctuations in a thermodynamic variable * Quantum fluctuation, arising from the uncertainty principle ** Primordial fluctuations, density variations in the early universe ** Universal conductance fluctuations, a quantum physics phenomenon encountered in electrical transport experiments in mesoscopic species Finance and economics * Economic conjuncture, a critical combination of events in economics * Volatility (finance) In finance, volatility (usually denoted by ''σ'') is the degree of variation of a trading price series over time, usually measured by the standard deviation of logarithmic returns. Historic volatility measures a time series of past market pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
