Sökning: "Cyclic losses"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden Cyclic losses.

1. 1. Energy Efficiency Improvements in Household Refrigeration Cooling Systems

   Författare :Erik Björk; Björn Palm; Claudio Melo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Household refrigerator; Domestic refrigerator; Free convection; Plate evaporator; Heat transfer; Flow boiling; Isobutane; R600a; Pressure drop; Two-phase; Cooling system; Charge inventory; Cyclic losses; Thermography;

   Sammanfattning : This thesis is based on eight articles all related to the characteristics of the cooling system and plate evaporator of a household refrigerator. Through these articles, knowledge is provided that can be used to increase the operational efficiency in household refrigeration. LÄS MER

3. 2. Diluted Operation of a Heavy-Duty Natural Gas Engine - Aiming at Improved Effciency, Emission and Maximum Load

   Författare :Mehrzad Kaiadi; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; Natural gas engine; Dilution limit; VGT; Cyclic variation; Closed-loop control; Heavy-duty;

   Sammanfattning : Most heavy-duty engines are diesel operated. Severe emission regulations, high fuel prices, high technology costs (e.g. catalysts, fuel injection systems) and unsustainably in supplying fuel are enough reasons to convenience engine developers to explore alternative technologies or fuels. LÄS MER

4. 3. Stepping into Catalysis : Kinetic and Mechanistic Investigations of Photo- and Electrocatalytic Hydrogen Production with Natural and Synthetic Molecular Catalysts

   Författare :Daniel Streich; Leif Hammarström; Reiner Lomoth; Clifford Kubiak; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Artificial photosynthesis; photocatalysis; electrocatalysis; hydrogen production; proton reduction; hydrogenase; iron complex; active site model; catalytic mechanism; transient absorption; spectroscopy; electrochemistry; cyclic voltammetry; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Sammanfattning : In light of its rapidly growing energy demand, human society has an urgent need to become much more strongly reliant on renewable and sustainable energy carriers. Molecular hydrogen made from water with solar energy could provide an ideal case. LÄS MER

5. 4. Charge transport in nanostructured metal oxide thin film electrodes

   Författare :Anita Solbrand; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : Nanostructured metal oxide electrodes are of great interest due to its wide field of potential applications, e.g. solar cells and batteries. The electron transport in nano-structured TiO2 and ZnO thin film electrodes was studied with time-resolved photo-currents and steady-state measurements. LÄS MER

7. 5. Ultrasound Communication through Thin Plates: Understanding the Channel

   Författare :Asra Ashraf; Jaap van de Beek; Johan E. Carlson; Magnus Sandell; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

   Sammanfattning : Ultrasound, composed of sound waves with frequencies above the human audible range, has become widely used in various technological fields for digital communications. In the past, acoustic and ultrasonic waves were employed in military and commercial un-derwater wireless communication systems due to their superior performance compared to electromagnetic waves. LÄS MER