Sökning: "resistance coefficient"

Visar resultat 1 - 5 av 99 avhandlingar innehållade orden resistance coefficient.

1. 1. Roller skis' rolling resistance and grip characteristics : influences on physiological and performance measures in cross-country skiers

   Författare :Mats Ainegren; Peter Carlsson; Marko Laaksonen; Mittuniversitetet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adjustable grip; blood lactate; centre of pressure; cycle length; cycle rate; economy; efficiency; friction coefficient; heart rate; normal force; OBLA; oxygen uptake; power; ratcheted wheel; ratings of perceived exertion; roller skis; rolling resistance; tangential force; time to exhaustion;

   Sammanfattning : The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers. LÄS MER

3. 2. Thermoelectric Ba8Ga16Ge30 clathrates for waste heat recovery

   Författare :Daniel Cederkrantz; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; thermal stability; substitution; thermal conductivity; Seebeck coefficient; electrical resistance; Clathrates; Ba8Ga16Ge30; waste heat recovery; semiconductors;

   Sammanfattning : The modern, highly industrialized, society of today requires huge amounts of energy to function. This has resulted in a heavy dependence on the very energy efficient fossil fuels, a source of energy which of course is not infinite and we are slowly approaching the day when oil runs out. LÄS MER

4. 3. Synthesis and Characterization of New Inorganic Thermoelectric Materials

   Författare :Daniel Cederkrantz; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; thermal conductivity.; Ba8Ga16Ge30; Seebeck coefficient; nanoinclusions; Thermoelectricity; waste heat recovery; clathrates; thermal stability; electrical resistance; Mg2Si; substitution; semiconductors;

   Sammanfattning : With thermoelectric materials it is possible to convert a difference in temperature into electrical energy. This can be utilized for a more efficient use of available energy, eg. by converting waste heat from a combustion process. LÄS MER

5. 4. 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

7. 5. Patch loading : resistance of longitudinally stiffened steel girder webs

   Författare :Carlos Graciano; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel Structures; Stålbyggnad;

   Sammanfattning : In most cases, longitudinal stiffeners increase the resistance of steel girder webs subjected to concentrated forces, commonly referred to as patch loading. During the last three decades, a number of experimental investigations have been undertaken in all over the world in this regard. LÄS MER