Sökning: "humidity"

Visar resultat 6 - 10 av 440 avhandlingar innehållade ordet humidity.

1. 6. Satellite measurements of upper tropospheric water

   Författare :Mattias Ekström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; cloud ice; upper troposphere; microwave; retrieval; the Odin satellite; humidity; limb-sounding;

   Sammanfattning : Water vapour and clouds in the upper troposphere have strong influence on the Earth's climate system. The present uncertainties regarding the distribution and feedback mechanisms of water to a changing climate are today among the greatest limitations for accurate climate predictions. LÄS MER

3. 7. Evaluating Tropical Upper-tropospheric Water in Climate Models Using Satellite Data

   Författare :Marston Sheldon Johnston; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ECHAM6; Humidity; Climate; CAM5; IWC; Clouds; EC-Earth;

   Sammanfattning : Measuring and simulating moist processes in the tropical upper troposphere are difficult tasks. Humidity in this region of the atmosphere is mainly supplied by deep convection and, problems with simulated convection areknown to be a major contributor to uncertainties in climate model projections. LÄS MER

4. 8. Dielectric properties of poly(ethyelene-co-butyl acrylate) filled with Alumina nanoparticles

   Författare :Nadejda Jäverberg; Hans Edin; Eva Mårtensson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanocomposites; poly ethylene-co-butyl acrylate ; EBA; alumina; dielectric permittivity; absorbed water; humidity; temperature; dielectric spectroscopy; partial discharge; electrical treeing; Electrical engineering; Elektroteknik;

   Sammanfattning : In this work dielectric properties of the poly(ethylene-co-butyl acrylate)filled with alumina nanoparticles are evaluated. These nanocomposite materialswere manufactured at the department of Fibre and Polymer Technology,KTH.This study is limited to the properties of general importance for the AC applications. LÄS MER

5. 9. Integration of graphene into MEMS and NEMS for sensing applications

   Författare :Xuge Fan; Frank Niklaus; Peter Steeneken; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Micro-electromechanical systems MEMS ; Nano-electromechanical systems NEMS ; heterogeneous 3D integration; Graphene; single-layer graphene; double-layer graphene; bilayer graphene; chemical vapor deposition CVD ; suspended graphene beams; suspended graphene membranes; doubly clamped; fully clamped; silicon on insulator SOI ; vapor hydrofluoric acid VHF ; Young’s modulus; built-in stress; built-in tension; piezoresistivity; gauge factor; accelerometer; resonators; electromechanical sensing; advanced transducers; humidity; gas sensing; sensitivity; CO2 sensing; graphene grain boundary; line defects; optical microscopy; wire bonding; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis presents a novel approach to integrate chemical vapor deposition (CVD) graphene into silicon micro- and nanoelectromechanical systems (MEMS/NEMS) to fabricate different graphene based MEMS/NEMS structures and explore mechanical properties of graphene as well as their applications such as acceleration sensing, humidity sensing and CO2 sensing. The thesis also presents a novel method of characterization of CVD graphene grain boundary based defects. LÄS MER

7. 10. Evaluating Cathode Catalysts in the Polymer Electrolyte Fuel Cell

   Författare :Henrik Ekström; Göran Lindbergh; Anders Lundblad; Anthony Kucernak; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fuel cell; humidity; model electrodes; Nafion; oxygen reduction; PEMFC; platinum; polymer electrolyte; thin film evaporation; titanium oxide; bränslecell; fuktighet; modellelektroder; Nafion; PEMFC; platina; polymerelektrolyt; syrereduktion; tunnfilmsförångning; titanoxid; Electrochemistry; Elektrokemi;

   Sammanfattning : The polymer electrolyte membrane fuel cell (PEMFC) converts the chemical energy of hydrogen and oxygen (air) into usable electrical energy. At the cathode (the positive electrode), a considerable amount of platinum is generally required to catalyse the sluggish oxygen reduction reaction (ORR). LÄS MER