Sökning: "gas velocity"

Visar resultat 1 - 5 av 258 avhandlingar innehållade orden gas velocity.

1. 1. Estimating the Air-Water Gas Transfer Velocity during Low Wind Conditions

   Författare :Sam Fredriksson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air.sea gas exchange; Turbulence; Heat flux; Natural convection; Shear; Direct numerical simulations; Gas transfer velocity; IR; Flux-chambers;

   Sammanfattning : The abundances of atmospheric carbon dioxide, CO2, and methane, CH4, are increasing. These increases affect e.g., the global carbon cycle and the climate both regionally and globally. LÄS MER

3. 2. Gas Exchange over Aquatic Interfaces and its Importance for Greenhouse Gas Emission

   Författare :Jovana Kokic; Sebastian Sobek; Erik Sahlée; Marcus B. Wallin; Anne Ojala; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gas exchange; lake; stream; lake sediment; headwaters; carbon dioxide; methane; greenhouse gas emission; carbon; turbulence; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Sammanfattning : Aquatic ecosystems play a substantial role in global cycling of carbon (C), despite covering only about 4% of the earth surface. They emit large amounts of greenhouse gases (GHG) to the atmosphere, comparable to the amount of C stored annually in terrestrial ecosystems. In addition, C can be buried in lake sediments. LÄS MER

4. 3. On mechanisms controlling air-sea gas exchange

   Författare :Lucía Gutiérrez-Loza; Anna Rutgersson; Erik Sahlée; Marcus B. Wallin; Tom Bell; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air-sea gas exchange; eddy covariance; gas transfer velocity; Baltic Sea; Meteorologi; Meteorology;

   Sammanfattning : Carbon is essential to the Earth’s system functioning, playing a major role in physical and biogeochemical processes in the atmosphere, the terrestrial biosphere, and the oceans. The concentration of carbon-based greenhouse gases in the atmosphere, such as carbon dioxide (CO2) and methane (CH4), has been increasing since the industrial era. LÄS MER

5. 4. Determining the quality of natural gas and biomethane : Development of a correlative method and instrument prototype for measuring gas quality

   Författare :Taras Koturbash; Vladimir G. Kutcherov; Andrew R. Martin; Khaled Loubar; KTH; []
   Nyckelord :Natural gas; biomethane; calorific value; Wobbe Index; ultrasonic measurement; sound attenuation; Energy Technology; Energiteknik;

   Sammanfattning : The composition of natural gas highly depends on its origin: natural gas from various deposits, substitute natural gas that can be produced from fossil fuels or renewable sources. The intermixing of gases from various supply sources during pipeline transportation also leads to more complicated and unpredictable gas composition variations at the consumption site. LÄS MER

7. 5. Charge carrier transport in field-effect transistors with two-dimensional electron gas channels studied using geometrical magnetoresistance effect

   Författare :Isabel Harrysson Rodrigues; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low-field mobility; high-electron-mobility transistor; velocity saturation; quasi-ballistic charge carrier transport; two-dimensional electron gas; charge carrier scattering mechanisms; geometrical magnetoresistance; low noise and high frequency applications; velocity peak; graphene field-effect transistor; charge carrier trans- port;

   Sammanfattning : During the last decades, significant efforts have been made to exploit the excellent and promising electronic properties exhibited by field-effect transistors (FETs) with two-dimensional electron gas (2DEG) channels. The most prominent representatives of this class of devices are high-electron-mobility transistors (HEMTs) and graphene field-effect transistors (GFETs). LÄS MER