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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 Steadman who published a paper about it in 1984. However, it also applies 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 effects of radiation (typically sunlight), humidi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Index
The heat index (HI) is an index that combines air temperature and relative humidity, in shaded areas, to posit a human-perceived equivalent temperature, as how hot it would feel if the humidity were some other value in the shade. The result is also known as the "felt air temperature", "apparent temperature", "real feel" or "feels like". For example, when the temperature is with 70% relative humidity, the heat index is . The humidity where the heat index feels like itself is typically left unstated. The heat index example in this case, 41°C, feels like 41°C only when the humidity is 21%. The human body normally cools itself by perspiration, or sweating. Heat is removed from the body by evaporation of that sweat. However, high relative humidity reduces the evaporation rate. This results in a lower rate of heat removal from the body, hence the sensation of being overheated. This effect is subjective, with different individuals perceiving heat differently for various reasons (such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Chill
Wind chill or windchill (popularly wind chill factor) is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values where the formula is valid. When the apparent temperature is higher than the air temperature, the heat index is used instead. Explanation A surface loses heat through conduction, evaporation, convection, and radiation. The rate of convection depends on both the difference in temperature between the surface and the fluid surrounding it and the velocity of that fluid with respect to the surface. As convection from a warm surface heats the air around it, an insulating boundary layer of warm air forms against the surface. Moving air disrupts this boundary layer, or epiclimate, allowing for cooler air to replace the warm air against the surface. The faster the wind speed, the more readily the surface cools. Alternative approaches Many formulas exist for wind chill beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equivalent Temperature
In atmospheric science, equivalent temperature is the temperature of air in a parcel from which all the water vapor has been extracted by an adiabatic process. Air contains water vapor that has been evaporated into it from liquid sources (lakes, sea, etc...). The energy needed to do that has been taken from the air. Taking a volume of air at temperature and mixing ratio of , drying it by condensation will restore energy to the airmass. This will depend on the latent heat release as: T_e \approx T + \frac r where: * L_v : latent heat of evaporation (2400 kJ/kg at 25°C to 2600 kJ/kg at −40°C) * c_ : specific heat at constant pressure for air (≈ 1004 J/(kg·K)) Tables exist for exact values of the last two coefficients. See also * Wet-bulb temperature * Potential temperature * Atmospheric thermodynamics * Equivalent potential temperature Bibliography * M Robitzsch, ''Aequivalenttemperatur und Aequivalentthemometer'', Meteorologische Zeitschrift, 1928, pp. 313-315. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Index
The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn-producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public. The UV index is designed as an open-ended linear scale, directly proportional to the intensity of UV radiation that causes human skin to sunburn. Using the Fitzpatrick scale, a light-skinned individual would experience sunburn in about 30 minutes at UV index 6, without sunscreen. That same individual would experience sunburn in only 15 minutes if the UV index was at 12. The purpose of the UV index is to help people effectively protect themselves from UV radiation, which has health benefits in moderation but in excess causes sunburn, skin aging, DNA damage, skin cancer, immunosuppression, and eye damage, such as cataracts. The scale was developed by Canadian scientists in 1992, and then adopted and standardized by the UN's Worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trade Secret
Trade secrets are a type of intellectual property that includes formulas, practices, processes, designs, instruments, patterns, or compilations of information that have inherent economic value because they are not generally known or readily ascertainable by others, and which the owner takes reasonable measures to keep secret. Intellectual property law gives the owner of a trade secret the right to restrict others from disclosing it. In some jurisdictions, such secrets are referred to as confidential information. Definition The precise language by which a trade secret is defined varies by jurisdiction, as do the particular types of information that are subject to trade secret protection. Three factors are common to all such definitions: A trade secret is information that * is not generally known to the public; * confers economic benefit on its holder the information is not publicly known; and * where the holder makes reasonable efforts to maintain its secrecy. In internation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AccuWeather
AccuWeather Inc. is an American media company that provides commercial weather forecasting services worldwide. AccuWeather was founded in 1962 by Joel N. Myers, then a Pennsylvania State University graduate student working on a master's degree in meteorology. His first customer was a natural gas, gas company in Pennsylvania. While running his company, Myers also worked as a member of Penn State's meteorology faculty. The company adopted the name "AccuWeather" in 1971. AccuWeather is headquartered in Ferguson Township, Centre County, Pennsylvania, Ferguson Township, just outside of State College, Pennsylvania, State College, Pennsylvania, with offices at 80 Pine Street in Financial_District,_Manhattan, Manhattan's Financial District in addition to Wichita, Kansas, Wichita, Kansas, and Oklahoma City, Oklahoma. Internationally, AccuWeather has offices in Montreal, Tokyo, Beijing, Seoul, and Mumbai. Company profile AccuWeather provides weather forecasts and warnings and additional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Weather Company
The Weather Company is a weather forecasting and information technology company that owns and operates weather.com and Weather Underground. The Weather Company has been a subsidiary of the Watson & Cloud Platform business unit of IBM since 2016. History and operations The Weather Company started as the Weather Channel in 1980, and launched two years later. In 2012, the company created a broader holding company and replaced the word "Channel" with "Company" to better reflect their growing lineup of digital products. The Weather Company was previously owned by a consortium made up of the Blackstone Group, Bain Capital, and NBCUniversal. That consortium sold the Weather Company's product and technology assets to IBM on January 29, 2016, but retained possession of The Weather Channel cable network until March 2018, when it was sold to Entertainment Studios. As part of the 2016 spin-off, the consortium entered into a long-term licensing agreement with IBM for use of its weather data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forbes
''Forbes'' () is an American business magazine owned by Integrated Whale Media Investments and the Forbes family. Published eight times a year, it features articles on finance, industry, investing, and marketing topics. ''Forbes'' also reports on related subjects such as technology, communications, science, politics, and law. It is based in Jersey City, New Jersey. Competitors in the national business magazine category include ''Fortune'' and ''Bloomberg Businessweek''. ''Forbes'' has an international edition in Asia as well as editions produced under license in 27 countries and regions worldwide. The magazine is well known for its lists and rankings, including of the richest Americans (the Forbes 400), of the America's Wealthiest Celebrities, of the world's top companies (the Forbes Global 2000), Forbes list of the World's Most Powerful People, and The World's Billionaires. The motto of ''Forbes'' magazine is "Change the World". Its chair and editor-in-chief is Steve Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globe Thermometer
__NOTOC__ The concept of mean radiant temperature (MRT) is used to quantify the exchange of radiant heat between a human and their surrounding environment, with a view to understanding the influence of surface temperatures on personal comfort. Mean radiant temperature has been both qualitatively defined and quantitatively evaluated for both indoor and outdoor environments. MRT has been defined as the uniform temperature of an imaginary enclosure in which the radiant heat transfer from the human body is equal to the radiant heat transfer in the actual non-uniform enclosure. MRT is a useful concept as the net exchange of radiant energy between two objects is approximately proportional to the product of their temperature difference multiplied by their emissivity (ability to emit and absorb heat). The MRT is simply the area weighted mean temperature of all the objects surrounding the body. This is meaningful as long as the temperature differences of the objects are small compared to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When blocked by clouds or reflected off other objects, sunlight is diffused. Sources estimate a global average of between 164 watts to 340 watts per square meter over a 24-hour day; this figure is estimated by NASA to be about a quarter of Earth's average total solar irradiance. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a requisite for vitamin D3 synthesis and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing direction eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet-bulb Globe Temperature
The wet-bulb globe temperature (WBGT) is a type of apparent temperature used to estimate the effect of temperature, humidity, wind speed ( wind chill), and visible and infrared radiation (usually sunlight) on humans. It is used by industrial hygienists, athletes, sporting events and the military to determine appropriate exposure levels to high temperatures. It is derived from the following formula: :\mathrm = 0.7T_\mathrm + 0.2T_\mathrm + 0.1T_\mathrm where * ''T''w = Natural wet-bulb temperature (combined with dry-bulb temperature indicates humidity) * ''T''g = Globe thermometer temperature (measured with a globe thermometer, also known as a black globe thermometer) * ''T''d = Dry-bulb temperature (actual air temperature) * Temperatures may be in either Celsius or Fahrenheit Indoors, or when solar radiation is negligible, the following formula is often used: :\mathrm = 0.7T_\mathrm + 0.3T_\mathrm Uses The American Conference of Governmental Industrial Hygienists publishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspiration
Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distributed over much of the body and are responsible for secreting the watery, brackish sweat most often triggered by excessive body temperature. The apocrine sweat glands are restricted to the armpits and a few other areas of the body and produce an odorless, oily, opaque secretion which then gains its characteristic odor from bacterial decomposition. In humans, sweating is primarily a means of thermoregulation, which is achieved by the water-rich secretion of the eccrine glands. Maximum sweat rates of an adult can be up to 2–4 liters per hour or 10–14 liters per day (10–15 g/min·m2), but is less in children prior to puberty. Evaporation of sweat from the skin surface has a cooling effect due to evaporative cooling. Hence, in hot weather ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
