Search for dissertations about: "spectral width"

Showing result 1 - 5 of 39 swedish dissertations containing the words spectral width.

2. 1. Wind turbine simulations using spectral elements

   Author : Elektra Kleusberg; Dan Henningson; Philipp Schlatter; Stefan Ivanell; Johan Meyers; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind turbine; wakes; wake interaction; computational fluid dynamics; actuator line method; spectral elements; free-stream turbulence; Engineering Mechanics; Teknisk mekanik;

   Abstract : Understanding the flow around wind turbines is a highly relevant research question due to the increased interest in harvesting energy from renewable sources. This thesis approaches the topic by means of numerical simulations using the actuator line method and the incompressible Navier–Stokes equations in the spectral element code Nek5000. READ MORE

4. 2. Atmospheric Species and Spectral Radiation in Terrestrial Exoplanets : Implications for Astrobiology

   Author : Samuel Konatham; Javier Martin-Torres; María-Paz Zorzano Mier; Akos Kereszturi; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Exoplanets; Atmospheres; Habitability; Human vision; Scotopic vision; Photopic vision; Spectral radaition; Atmosfärsvetenskap; Atmospheric science;

   Abstract : The physical properties of the planets and their parent stars are fundamental in the composition of atmospheres and radiative environments, which fundamentally determine their surface temperature and habitability. The atmospheric composition and radiation play a vital role in the emergence of life. READ MORE

5. 3. Quasi-Single Mode VCSELs for Longer-Reach Optical Interconnects

   Author : Erik Haglund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasi-single mode; oxide aperture; mode filter; vertical-cavity surface-emitting laser; high-speed modulation; mode control; spectral width;

   Abstract : The vertical-cavity surface-emitting laser (VCSEL) is the standard light source in optical interconnects connecting racks in supercomputers and datacenters hosting services such as online data sharing, storage and processing. VCSELs have numerous advantages such as low power consumption, fast direct modulation at low currents, circular output beam for efficient fiber coupling and low-cost fabrication. READ MORE

6. 4. Pulse-Width Modulated RF Transmitters

   Author : Muhammad Fahim Ul Haque; Ted Johansson; Dake Liu; Qamar Ul Wahab; Franz Dielacher; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The market for wireless portable devices has grown signicantly over the recent years.Wireless devices with ever-increased functionality require high rate data transmissionand reduced costs. READ MORE

7. 5. VCSELs for High-Speed, Long-Reach, and Wavelength-Multiplexed Optical Interconnects

   Author : Erik Haglund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; mode filter; high-contrast grating; oxide aperture; high-speed modulation; wavelength control; spectral width; vertical-cavity surface-emitting laser; optical interconnect; quasi-single-mode;

   Abstract : The vertical-cavity surface-emitting laser (VCSEL) is the standard light source in short-reach fiber-optic links in datacenters and supercomputers. These systems use an enormous number of links, making cost and energy efficiency pressing issues. READ MORE