Sökning: "thermal resistance"

Visar resultat 1 - 5 av 361 avhandlingar innehållade orden thermal resistance.

1. 1. Characterization and Compensation of Thermal Effects in GaN HEMT Technologies

   Författare :Johan Bremer; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal coupling; thermal effects; thermal resistance; AlGaN GaN; temperature compensation.; electrothermal; characterization;

   Sammanfattning : Further advancements with GaN based technologies relies on the ability to handle the heat flux, which consequently arises from the high power density. Advanced cooling techniques and thermal optimization of the technology are therefore prioritized research areas. LÄS MER

3. 2. Advances in Thermal Insulation : Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

   Författare :Thomas Thorsell; Folke Björk; Mark Bomberg; Targo Kalamees; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vacuum insulation panels; VIP; serpentine edge; thermal bridge; composite film; gas diffusion; defect dominated; holistic approach; building enclosure; integrated testing and modeling; energy equivalent; field performance; air flow; thermal insulation efficiency;

   Sammanfattning : We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. LÄS MER

4. 3. Cellulose-fiber-based thermal insulation materials with fungal resistance, improved water resistance and reaction-to-fire properties

   Författare :Chao Zheng; Monica Ek; Dongfang Li; Lars Wågberg; Folke Björk; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biorefinery; birch bark; cellulose; reaction-to-fire properties; fungal resistance; thermal insulation; water resistance; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Thermal insulation materials made from natural fibrous materials, such as cellulose fibers, have advantages over others from a sustainability point of view. However, cellulosic materials are generally prone to mold and absorb moisture, and these have negative effects on the insulation properties, the durability of insulation materials, and interior air quality. LÄS MER

5. 4. Thermal response test : in situ measurements of thermal properties in hard rock

   Författare :Signhild Gehlin; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vattenteknik; Water Resources Engineering;

   Sammanfattning : In-situ determination of thermal properties in bedrock is important for the sizing of larger BTES systems. In-situ values of thermal conductivity may reduce required borehole length up to 30%. This thesis treats a new mobile thermal response test equipment (TED), developed in Luleå, Sweden, 1995-98. LÄS MER

7. 5. Investigation of Thermal Performance of Cylindrical Heatpipes Operated with Nanofluids

   Författare :Morteza Ghanbarpourgeravi; Rahmatollah Khodabandeh; Björn Palm; Oronzio Manca; KTH; []
   Nyckelord :Nanofluid; heat pipe; thermal resistance; heat transfer coefficient; evaporator; condenser; wick; porous layer; heat flux; inclination angle; thermal conductivity; viscosity; Energiteknik; Energy Technology;

   Sammanfattning : Nanofluids as an innovative class of heat transfer fluids created by dispersing nanometre-sizedmetallic or non-metallic particles in conventional heat transfer fluids displayed the potential toimprove the thermophysical properties of the heat transfer fluids. The main purpose of this study is toinvestigate the influence of the use of nanofluids on two-phase heat transfer, particularly on thethermal performance of the heat pipes. LÄS MER