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Stefan's Equation
In glaciology and civil engineering, Stefan's equation (or Stefan's formula) describes the dependence of ice-cover thickness on the temperature history. It says in particular that the expected ice accretion is proportional to the square root of the number of degree days below freezing. It is named for Slovenian physicist Josef Stefan. See also * Stefan problem References * * Stefan's formulain the ''McGraw-Hill Dictionary of Scientific and Technical Terms'' at Answers.com Answers.com, formerly known as WikiAnswers, is an Internet-based knowledge exchange. The Answers.com domain name was purchased by entrepreneurs Bill Gross and Henrik Jones at idealab in 1996. The domain name was acquired by NetShepard and subs ... (archived) Civil engineering Glaciology Snow or ice weather phenomena {{glaciology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stefan's Formula
In thermodynamics, Stefan's formula says that the specific surface energy at a given interface is determined by the respective enthalpy difference \scriptstyle \Delta H^*. : \sigma = \gamma_0 \left( \frac\right), where ''σ'' is the specific surface energy, ''N''A is the Avogadro constant, \gamma_0 is a steric dimensionless coefficient, and ''V''m is the molar volume In chemistry and related fields, the molar volume, symbol ''V''m, or \tilde V of a substance is the ratio of the volume occupied by a substance to the amount of substance, usually given at a given temperature and pressure. It is equal to the molar .... References {{Reflist Thermodynamic equations Chemical thermodynamics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciology
Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and ecology. The impact of glaciers on people includes the fields of human geography and anthropology. The discoveries of water ice on the Moon, Mars, Europa and Pluto add an extraterrestrial component to the field, which is referred to as "astroglaciology". Overview A glacier is an extended mass of ice formed from snow falling and accumulating over a long period of time; glaciers move very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers. Areas of study within glaciology include glacial history and the reconstruction of past glaciation. A glaciologist is a person who studies glaciers. A glacial geologist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to global Fortune 500 companies. History Civil engineering as a discipline Civil engineering is the application of physical and scientific principles for solving the problems of society, and its history is intricately linked to advances in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degree Days
A degree day is a measure of heating or cooling. Total degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing. Weekly or monthly degree-day figures may also be used within an energy monitoring and targeting scheme to monitor the heating and cooling costs of climate controlled buildings, while annual figures can be used for estimating future costs. A degree day is computed as the integral of a function of time that generally varies with temperature. The function is truncated to upper and lower limits that vary by organism, or to limits that are appropriate for climate control. The function can be estimated or measured by one of the following methods, in each case by reference to a chosen base temperature: * Frequent measurements and continuously integrating the temperature deficit or excess; * Treating each day's temperature profile as a sine wave with amplitude equal to the day's temperature variation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josef Stefan
Josef Stefan ( sl, Jožef Štefan; 24 March 1835 – 7 January 1893) was an ethnic Carinthian Slovene physicist, mathematician, and poet of the Austrian Empire. Life and work Stefan was born in an outskirt village of St. Peter (Slovene: ; today a district of Klagenfurt) in the Austrian Empire (now in Austria) to father Aleš (Aleksander) Stefan, born in 1805, and mother Marija Startinik, born 1815. His parents, both ethnic Slovenes, married when Josef was eleven. The Stefans were a modest family. His father was a milling assistant and his mother served as a maidservant. Stefan's mother died in 1863 and his father in 1872. Josef was their only child. Stefan attended elementary school in Klagenfurt, where he showed his talent. They recommended to him to continue his schooling, so in 1845, he went to . As a thirteen-year-old boy, he experienced the revolutionary year of 1848, which inspired him to be sympathetic toward Slovene literary production. After having graduated top o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stefan Problem
In mathematics and its applications, particularly to phase transitions in matter, a Stefan problem is a particular kind of boundary value problem for a system of partial differential equations (PDE), in which the boundary between the phases can move with time. The classical Stefan problem aims to describe the evolution of the boundary between two phases of a material undergoing a phase change, for example the melting of a solid, such as ice to water. This is accomplished by solving heat equations in both regions, subject to given boundary and initial conditions. At the interface between the phases (in the classical problem) the temperature is set to the phase change temperature. To close the mathematical system a further equation, the Stefan condition, is required. This is an energy balance which defines the position of the moving interface. Note that this evolving boundary is an unknown (hyper-)surface; hence, Stefan problems are examples of free boundary problems. Analogous p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Answers
Answer commonly refers to response to a question. Answer may also refer to: * Answer (law), any reply to a question, counter-statement or defense in a legal procedure Music * Answer, an element of a fugue Albums * ''Answer'' (Angela Aki album), 2009 * ''Answer'' (Supercar album), 2004 * ''Answers'' (album), 1994 * ''The Answers'', an album by Blue October Songs * "Answer" (Tohoshinki song) * "Answer" (Flow song), 2007 *"Answer", by Tyler, the Creator from the album ''Wolf'' *"Answer", by Sarah McLachlan from her 2003 album ''Afterglow'' *"Answer", by Mayu Maeshima, opening song from the 2021 anime ''Full Dive'' Publications * ''Answers'' (periodical), British weekly paper founded in 1888, initially titled ''Answers to Correspondents'' *''Answer'', a very short science-fiction story published in 1954 by Fredric Brown. *''Answers'', an American magazine published by Answers in Genesis * ''The Questionnaire'' (Salomon novel), also published as "The Answers" Groups, organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to global Fortune 500 companies. History Civil engineering as a discipline Civil engineering is the application of physical and scientific principles for solving the problems of society, and its history is intricately linked to advances in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciology
Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and ecology. The impact of glaciers on people includes the fields of human geography and anthropology. The discoveries of water ice on the Moon, Mars, Europa and Pluto add an extraterrestrial component to the field, which is referred to as "astroglaciology". Overview A glacier is an extended mass of ice formed from snow falling and accumulating over a long period of time; glaciers move very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers. Areas of study within glaciology include glacial history and the reconstruction of past glaciation. A glaciologist is a person who studies glaciers. A glacial geologist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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