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Humidity And Hygrometry
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 8 g of water per cubic metre of air at , and 28 g of water per cubic metre of air at Three primary measurements of humidity are widely employed: absolute, relative, and specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RH Wiki
RH, Rh, rH, or rh may refer to: Companies * Red Hat, an American software company * Republic Express Airlines (IATA designator), a cargo airline in Indonesia * RH (company), an American furniture chain formerly known as Restoration Hardware Science and technology * Relative humidity, the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature * Releasing hormone * Reproductive health * Rh blood group system (''Rhesus factor''), a classification to describe blood types in humans * Rhodium, symbol Rh, a chemical element * RH, the Rydberg constant for hydrogen * Riemann hypothesis, an important unsolved problem in mathematics * Adobe RoboHelp, an Adobe software Places * RH postcode area, in the UK * , an official name of Croatia in Croatian * Other uses * Rh (digraph) * The Right Honourable ''The Right Honourable'' (abbreviation: The Rt Hon. or variations) is an honorific Style (form of address), style traditionally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deposition (phase Transition)
Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation. Applications Examples One example of deposition is the process by which, in sub-freezing air, water vapour changes directly to ice without first becoming a liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th .... This is how frost and hoar frost form on the ground or other surfaces, including leaves. For deposition to occur, thermal energy must be removed from a gas. When the air becomes cold enough, water vapour in the air surrounding a leaf loses enough thermal energy to change into a solid. Even though the air tempera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVAC
Heating, ventilation, and air conditioning (HVAC ) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers). HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels, and senior living facilities; medium to large industrial and office buildings such as skyscrapers and hospitals; vehicles such as cars, trains, airplanes, ships and submarines; and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixing Ratio
In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio (see concentration) or mass ratio (see stoichiometry). In atmospheric chemistry and meteorology Mole ratio In atmospheric chemistry, mixing ratio usually refers to the mole ratio ''ri'', which is defined as the amount of a constituent ''ni'' divided by the total amount of all ''other'' constituents in a mixture: :r_i = \frac The mole ratio is also called amount ratio. If ''ni'' is much smaller than ''n''tot (which is the case for atmospheric trace constituents), the mole ratio is almost identical to the mole fraction. Mass ratio In meteorology, mixing ratio usually refers to the mass ratio of water \zeta, which is defined as the mass of water m_\mathrm divided by the mass of dry air (m_\mathrm-m_\mathrm) in a given air parcel: :\zeta = \frac The unit is typically given in \mathrm\,\mathrm^. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 8 g of water per cubic metre of air at , and 28 g of water per cubic metre of air at Three primary measurements of humidity are widely employed: abso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Temperature
Apparent temperature, also known as "feels like", is the temperature equivalent perceived by humans, caused by the combined effects of air temperature, relative humidity and wind speed. The measure is most commonly applied to the perceived outdoor temperature. Apparent temperature was invented by Robert G. Steadman who published a paper about it in 1984. It also applies, however, to indoor temperatures, especially saunas, and when houses and workplaces are not sufficiently heated or cooled. * The heat index and humidex measure the effect of humidity on the perception of temperatures above . In humid conditions, the air feels much hotter, because less perspiration evaporates from the skin. * The wind chill factor measures the effect of wind speed on cooling of the human body below . As airflow increases over the skin, more heat will be removed. Standard models and conditions are used. * The wet-bulb globe temperature (WBGT) combines the Effect of radiation on perceived temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Forecasting
Weather forecasting or weather prediction is the application of science and technology forecasting, to predict the conditions of the Earth's atmosphere, atmosphere for a given location and time. People have attempted to predict the weather informally for thousands of years and formally since the 19th century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere, land, and ocean and using meteorology to project how the atmosphere will change at a given place. Once calculated manually based mainly upon changes in atmospheric pressure, barometric pressure, current weather conditions, and sky conditions or cloud cover, weather forecasting now relies on numerical weather prediction, computer-based models that take many atmospheric factors into account. Human input is still required to pick the best possible model to base the forecast upon, which involves pattern recognition skills, teleconnections, knowledge of model performance, and kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indicator (statistics)
In statistics and research design, an indicator is an observed value of a variable, or in other words "a sign of a presence or absence of the concept being studied". Just like each color indicates in a traffic lights the change in the movement. For example, if a variable is religiosity, and a unit of analysis is an individual, then that one of potentially more numerous indicators of that individual's religiosity would be whether they attend religious services; others - how often, or whether they donate money to religious organizations. Numerous indicators can be aggregated into an index. The complexity of biological systems makes evaluating them a challenge. Bioindicators, such as indicator bacteria, are ecological indicators, sometimes requiring further consideration of environmental indicators. In public health study, one relies on health indicators. In a given locality, community indicators inform planners, while the design quality indicator can be the basis of buildi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturation Vapor Pressure
Vapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indication of a liquid's thermodynamic tendency to evaporate. It relates to the balance of particles escaping from the liquid (or solid) in equilibrium with those in a coexisting vapor phase. A substance with a high vapor pressure at normal temperatures is often referred to as '' volatile''. The pressure exhibited by vapor present above a liquid surface is known as vapor pressure. As the temperature of a liquid increases, the attractive interactions between liquid molecules become less significant in comparison to the entropy of those molecules in the gas phase, increasing the vapor pressure. Thus, liquids with strong intermolecular interactions are likely to have smaller vapor pressures, with the reverse true for weaker interactions. The vapor p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
