1.
Vapor
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A vapor is different from an aerosol. An aerosol is a suspension of particles of liquid, solid. For example, water has a temperature of 647 K. In the atmosphere at ordinary temperatures, therefore, gaseous water will condense into a liquid if its pressure is increased sufficiently. A vapor may co-exist with a liquid, when this is true, the two phases will be in equilibrium, and the gas-partial pressure will be equal to the equilibrium vapor pressure of the liquid. Vapor refers to a gas phase at a temperature where the substance can also exist in the liquid or solid state. If the vapor is in contact with a liquid or solid phase, the term gas refers to a compressible fluid phase. Fixed gases are gases for which no liquid or solid can form at the temperature of the gas, a liquid or solid does not have to boil to release a vapor. Vapor is responsible for the processes of cloud formation and condensation. It is commonly employed to carry out the processes of distillation. The constituent molecules of a vapor possess vibrational, rotational, and these motions are considered in the kinetic theory of gases. The vapor pressure is the pressure from a liquid or a solid at a specific temperature. The equilibrium vapor pressure of a liquid or solid is not affected by the amount of contact with the liquid or solid interface, the normal boiling point of a liquid is the temperature at which the vapor pressure is equal to normal atmospheric pressure. For two-phase systems, the pressure of the individual phases are equal. The total vapor pressure is the sum of the component partial pressures, perfumes contain chemicals that vaporize at different temperatures and at different rate in scent accords known as notes. Atmospheric water vapor is found near the surface, and may condense into small liquid droplets and form meteorological phenomena such as fog, mist. Mercury-vapor lamps and sodium vapor lamps produce light from atoms in excited states, flammable liquids do not burn when ignited. It is the cloud above the liquid that will burn if the vapors concentration is between the lower flammable limit and upper flammable limit of the flammable liquid
2.
Liquid
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A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure. As such, it is one of the four states of matter. A liquid is made up of tiny vibrating particles of matter, such as atoms, water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container, most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, a distinctive property of the liquid state is surface tension, leading to wetting phenomena. The density of a liquid is usually close to that of a solid, therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is in form as interstellar clouds or in plasma form within stars. Liquid is one of the four states of matter, with the others being solid, gas. Unlike a solid, the molecules in a liquid have a greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, a liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, if liquid is placed in a bag, it can be squeezed into any shape. These properties make a suitable for applications such as hydraulics. Liquid particles are bound firmly but not rigidly and they are able to move around one another freely, resulting in a limited degree of particle mobility. As the temperature increases, the vibrations of the molecules causes distances between the molecules to increase. When a liquid reaches its point, the cohesive forces that bind the molecules closely together break. If the temperature is decreased, the distances between the molecules become smaller, only two elements are liquid at standard conditions for temperature and pressure, mercury and bromine. Four more elements have melting points slightly above room temperature, francium, caesium, gallium and rubidium, metal alloys that are liquid at room temperature include NaK, a sodium-potassium metal alloy, galinstan, a fusible alloy liquid, and some amalgams
3.
Water vapor
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Water vapor, water vapour or aqueous vapor, is the gaseous phase of water. It is one state of water within the hydrosphere, water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible, under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is lighter than air and triggers convection currents that can lead to clouds, use of water vapor, as steam, has been important to humans for cooking and as a major component in energy production and transport systems since the industrial revolution. Likewise the detection of water vapor would indicate a similar distribution in other planetary systems. Water vapor is significant in that it can be evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects. Whenever a water molecule leaves a surface and diffuses into a surrounding gas, each individual water molecule which transitions between a more associated and a less associated state does so through the absorption or release of kinetic energy. The aggregate measurement of kinetic energy transfer is defined as thermal energy. Liquid water that becomes water vapor takes a parcel of heat with it, the amount of water vapor in the air determines how fast each molecule will return to the surface. When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water, in the US, the National Weather Service measures the actual rate of evaporation from a standardized pan open water surface outdoors, at various locations nationwide. Others do likewise around the world, the US data is collected and compiled into an annual evaporation map. The measurements range from under 30 to over 120 inches per year, formulas can be used for calculating the rate of evaporation from a water surface such as a swimming pool. In some countries, the evaporation rate far exceeds the precipitation rate, evaporative cooling is restricted by atmospheric conditions. Humidity is the amount of vapor in the air. The vapor content of air is measured with devices known as hygrometers, the measurements are usually expressed as specific humidity or percent relative humidity. This condition is referred to as complete saturation. Humidity ranges from 0 gram per cubic metre in dry air to 30 grams per cubic metre when the vapor is saturated at 30 °C, another form of evaporation is sublimation, by which water molecules become gaseous directly, leaving the surface of ice without first becoming liquid water. Sublimation accounts for the slow disappearance of ice and snow at temperatures too low to cause melting
4.
Cloud chamber
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The cloud chamber, also known as the Wilson chamber, is a particle detector used for detecting ionizing radiation. In its most basic form, a chamber is a sealed environment containing a supersaturated vapor of water or alcohol. When a charged particle interacts with the mixture, the fluid is ionized, the resulting ions act as condensation nuclei, around which a mist will form. The high energies of alpha and beta particles mean that a trail is left, Cloud chambers played a prominent role in the experimental particle physics from the 1920s to the 1950s, until the advent of the bubble chamber. In particular, the discoveries of the positron in 1932, the muon in 1936, Anderson detected the positron and muon in cosmic rays. Charles Thomson Rees Wilson, a Scottish physicist, is credited with inventing the cloud chamber, inspired by sightings of the Brocken spectre while working on the summit of Ben Nevis in 1894, he began to develop expansion chambers for studying cloud formation and optical phenomena in moist air. Very rapidly he discovered that ions could act as centers for water droplet formation in such chambers and he pursued the application of this discovery and perfected the first cloud chamber in 1911. When an ionizing particle passes through the chamber, water condenses on the resulting ions. Wilson, along with Arthur Compton, received the Nobel Prize in Physics in 1927 for his work on the cloud chamber and this kind of chamber is also called a Pulsed Chamber because the conditions for operation are not continuously maintained. Further developments were made by Patrick Blackett who utilised a stiff spring to expand and compress the chamber very rapidly, a cine film was used to record the images. The diffusion cloud chamber was developed in 1936 by Alexander Langsdorf, instead of water vapor, alcohol is used because of its lower freezing point. Cloud chambers cooled by dry ice are a demonstration and hobbyist device. There are also water-cooled diffusion cloud chambers, using ethylene glycol, a simple cloud chamber consists of the sealed environment, radioactive source, dry ice or a cold plate and some kind of alcohol source. The alcohol falls as it cools down and the cold condenser provides a steep temperature gradient, the result is a supersaturated environment. The alcohol vapor condenses around ion trails left behind by the travelling ionizing particles, the result is cloud formation, seen in the cloud chamber by the presence of droplets falling down to the condenser. As particles pass through they leave ionization trails and because the vapor is supersaturated it condenses onto these trails. Since the tracks are emitted radially out from the source, their point of origin can easily be determined, just above the cold condenser plate there is an area of the chamber which is sensitive to radioactive tracks. At this height, most of the alcohol has not condensed and this means that the ion trail left by the radioactive particles provides an optimal trigger for condensation and cloud formation
5.
Supersaturation
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Supersaturation is a state of a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances. It can also refer to a vapor of a compound that has a higher pressure than the pressure of that compound. Special conditions need to be met in order to generate a supersaturated solution, one of the easiest ways to do this relies on the temperature dependence of solubility. As a general rule, the heat is added to a system. Therefore, at high temperatures, more solute can be dissolved than at room temperature, the precipitation or crystallization of the solute takes longer than the actual cooling time because the molecules need to meet up and form the precipitate without being knocked apart by water. Thus, the larger the molecule, the longer it will take to crystallize due to the principles of Brownian motion, the condition of supersaturation does not necessarily have to be reached through the manipulation of heat. The ideal gas law suggests that pressure and volume can also be changed to force a system into a supersaturated state, if the volume of solvent is decreased, the concentration of the solute can be above the saturation point and thus create a supersaturated solution. The decrease in volume is most commonly generated through evaporation, similarly, an increase in pressure can drive a solution to a supersaturated state. All three of these rely on the fact that the conditions of the solution can be changed quicker than the solute can precipitate or crystallize out. Supersaturated solutions will also undergo crystallization under specific conditions, in a normal solution, once the maximum amount of solute is dissolved, adding more solute would either cause the dissolved solute to precipitate out and/or for the solute to not dissolve at all. Similarly, there are cases wherein solubility of a solution is decreased by manipulating temperature, pressure, or volume. In these cases, the solute will simply precipitate out and this is due to the fact that a supersaturated solution is in a higher energy state than a saturated solution. Crystallization will occur to allow the solution to reach an energy state. The activation energy comes in the form of a crystal being added to the liquid solution. This nuclei can be added from another source, which is known as seeding, or can spontaneously form within the solution due partly to ion. This process is known as primary nucleation and it is necessary for the nuclei to be identical to the solute that is crystallizing. This will allow for the ions to build up on the nuclei. There are a multitude of factors that affect the rate and order of magnitude with which crystallization proceeds as well as the difference in formation of crystallites
6.
Cloud seeding
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The usual intent is to increase precipitation, but hail and fog suppression are also widely practiced in airports. Cloud seeding also occurs due to ice nucleators in nature, most of which are bacterial in origin, the most common chemicals used for cloud seeding include silver iodide, potassium iodide and dry ice. Liquid propane, which expands into a gas, has also been used and this can produce ice crystals at higher temperatures than silver iodide. After promising research, the use of materials, such as table salt, is becoming more popular. When Cloud seeding increases snowfall takes place when temperatures within the clouds are between 19 and −4 °F, introduction of a substance such as silver iodide, which has a crystalline structure similar to that of ice, will induce freezing nucleation. In mid-latitude clouds, the usual seeding strategy has been based on the fact that the vapor pressure is lower over ice than over water. The formation of ice particles in super cooled clouds allows those particles to grow at the expense of liquid droplets, if sufficient growth takes place, the particles become heavy enough to fall as precipitation from clouds that otherwise would produce no precipitation. This process is known as static seeding, Seeding of warm-season or tropical cumulonimbus clouds seeks to exploit the latent heat released by freezing. Cloud seeding chemicals may be dispersed by aircraft or by dispersion devices located on the ground, for release by aircraft, silver iodide flares are ignited and dispersed as an aircraft flies through the inflow of a cloud. When released by devices on the ground, the particles are carried downwind. An electronic mechanism was tested in 2010, when infrared laser pulses were directed to the air above Berlin by researchers from the University of Geneva, the experimenters posited that the pulses would encourage atmospheric sulfur dioxide and nitrogen dioxide to form particles that would then act as seeds. Cloud seeding has never been proven to work. Claims are made that new technology and research has produced results that make cloud seeding a dependable and affordable water supply practice for many regions. But while practiced widely around the world, the effectiveness of cloud seeding is still a matter of academic debate, in 2003 the US National Research Council released a report stating. science is unable to say with assurance which, if any, seeding techniques produce positive effects. In the 55 years following the first cloud-seeding demonstrations, substantial progress has made in understanding the natural processes that account for our daily weather. Yet scientifically acceptable proof for significant seeding effects has not been achieved, referring to 1903,1915,1919,1944, and 1947 weather modification experiments, the Australian Federation of Meteorology discounted rain making. By the 1950s, the CSIRO Division of Radiophysics switched to investigating the physics of clouds and had hoped by 1957 to better understand these processes. By the 1960s, the dreams of making had faded only to be re-ignited post-corporatisation of the Snowy Mountains Scheme in order to achieve above target water
7.
Climate engineering
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Climate engineering is an umbrella term for two types of measures, carbon dioxide removal and solar radiation management. Carbon dioxide removal addresses the cause of change by removing one of the greenhouse gases from the atmosphere. Solar radiation management attempts to offset effects of gases by causing the Earth to absorb less solar radiation. Climate engineering approaches are sometimes viewed as potential options for limiting climate change. There is substantial agreement among scientists that climate engineering cannot substitute for climate change mitigation, some approaches might be used as accompanying measures to sharp cuts in greenhouse gas emissions. Research on costs, benefits, and various types of risks of most climate engineering approaches is at a stage and their understanding needs to improve to judge their adequacy. Almost all research into solar radiation management has consisted of computer modelling or laboratory tests, some carbon dioxide removal practices, such as planting of trees and bio-energy with carbon capture and storage projects, are underway. Their scalability to effectively affect global climate is, however, debated, ocean iron fertilization has been given small-scale research trials, sparking substantial controversy. However, most experts also argue that the risks of such interventions must be seen in the context of risks of climate change. Groups such as ETC Group and some researchers are in favour of a moratorium on out-of-doors testing. With respect to climate, geoengineering is defined by the Royal Society as, the deliberate large-scale intervention in the Earth’s climate system, in order to moderate global warming. The Asilomar International Conference on Climate Intervention Technologies was convened to identify, some authors have argued that any public support for climate engineering may weaken the fragile political consensus to reduce greenhouse gas emissions. Several climate engineering strategies have been proposed, IPCC documents detail several notable proposals. These fall into two categories, solar radiation management and carbon dioxide removal. Here is a list of specific proposals, Solar radiation management techniques would seek to reduce sunlight absorbed. This would be achieved by deflecting sunlight away from the Earth and these methods would not reduce greenhouse gas concentrations in the atmosphere, and thus would not seek to address problems such as the ocean acidification caused by CO2. Furthermore, many proposed SRM methods would be reversible in their direct climatic effects, while greenhouse gas remediation offers a more comprehensive possible solution to climate change, it does not give instantaneous results, for that, solar radiation management is required. Solar radiation management methods may include, Surface-based, for example, using pale-colored roofing materials, attempting to change the oceans brightness, troposphere-based, for example, marine cloud brightening, which would spray fine sea water to whiten clouds and thus increase cloud reflectivity
