Sökning: "window opening"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden window opening.

1. 1. Ventilation and window opening in schools, Experiments and Analysis

   Författare :Birgitta Nordquist; Avdelningen för Installations- och klimatiseringslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat exchanger efficiency; duct design; balancing; disturbance; tracer gas measurements; analytical model; window opening; single-sided ventilation; ventilation; schools; sensitivity analysis; Building construction; Byggnadsteknik;

   Sammanfattning : The objective of this thesis is to study the application of ventilation in schools buildings. A number of studies of the application of different forms of ventilation are presented. The main part of the thesis focuses on window opening in a classroom. Analytical models for calculation of the air change caused by window airing are proposed. LÄS MER

3. 2. Opening New Radio Windows and Bending Twisted Beams

   Författare :Erik Nordblad; Thomas B. Leyser; Kristof Stasiewicz; Vladimir Pavlenko; Paul A. Bernhardt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Orbital angular momentum; Hall effect; Nonparaxial beam; Geometrical optics; High frequency radio waves; Ray tracing; Magnetic zenith effect; Ionospheric irregularities; Wave propagation; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

   Sammanfattning : In ground based high frequency (HF) radio pumping experiments, absorption of ordinary (O) mode pump waves energises the ionospheric plasma, producing optical emissions and other effects. Pump-induced or natural kilometre-scale field-aligned density depletions are believed to play a role in self-focussing phenomena such as the magnetic zenith (MZ) effect, i. LÄS MER

4. 3. Three Phase Controlled Fault Interruption Using High Voltage SF6 Circuit Breakers

   Författare :Richard Thomas; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; controlled switching; high voltage; hypothesis testing; circuit breakers; fault interruption; least mean squares regression; power system protection;

   Sammanfattning : A method is presented for implementing controlled fault interruption,using high voltage, SF6 circuit breakers on three phase high voltage powernetworks. The main goal of the method is to synchronize the opening or tripcommands to each phase of a circuit breaker with respect to target currentzero times so that each phase will interrupt with a preselected arcingtime. LÄS MER

5. 4. Exploring bio-based and biodegradable polymers: free-radical polymerization, hydrolysis and applications

   Författare :Maryam Mousa; Eva Malmström; Magnus Jonsson; Anna Larsson Kron; Seema Agarwal; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Bio-based polymers; biodegradation; branched polyesters; thermally expandable microspheres; copolymerization; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Increasing concerns regarding the depletion of fossil-based resources and theaccumulation of plastic waste in the environment have resulted in extensiveresearch aimed at finding more sustainable alternatives to today’s plastics.In this work, bio-based and biodegradable polymers have been synthesizedusing free-radical polymerization in homogeneous and heterogeneoussystems. LÄS MER

7. 5. HCCI Combustion by Retaining Residuals. Development and Analyses of a Method to Reduce Fuel Consumption for Passenger Car Gasoline Engines

   Författare :Lucien Koopmans; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; gasoline; variable valve timing; homogeneous charge compression ignition HCCI ; internal combustion engines; fuel-consumption; engine emissions; controlled auto-ignition CAI ;

   Sammanfattning : The demand for more powerful engines on one hand, and greater fuel-efficiency on the other, requires a revolution in engine combustion technology. Homogeneous charge compression ignition (HCCI) can be a fuel-saving, low emissions approach that seems to be very suitable for large displacement passenger car engines. LÄS MER