Sökning: "reflection coefficient"

Visar resultat 16 - 20 av 33 avhandlingar innehållade orden reflection coefficient.

1. 16. Light Scattering Effects in Transparent Wood Biocomposites

   Författare :Hui Chen; Lars Berglund; Ilya Sychugov; Max Yan; Mikael Sjödahl; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transparent wood; cellulose; biocomposite; light transmission; anisotropic scattering; Rayleigh scattering; photon budget; photon diffusion theory; light-transparent wood interaction; Transparent trä; cellulosa; biokomposit; ljustransmission; anisotropisk spridning; Rayleigh-spridning; fotonbudget; fotondiffusionsteori; ljus-transparent trä interaktion; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Transparent wood (TW) shows interesting optical properties and offers a sustainable alternative to petroleum-based polymer glasses. The influence of the TW internal structure (e.g. LÄS MER

3. 17. Methods for Modelling and Characterization of In-Duct Sources

   Författare :Hans Rämmal; Hans Bodén; Mats Åbom; Antonio Torregrosa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Methods to characterize acoustic sources in flow ducts have been investigated. In the first part of this thesis a measurement procedure to characterize an air terminal device using an acoustic one-port source model based on the two microphone technique has been tested and validated. LÄS MER

4. 18. Analytical Aspects of Atmospheric Pressure Ionisation in Mass Spectrometry

   Författare :C. Fredrik Bökman; J. David Pinkston; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Analytisk kemi; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

   Sammanfattning : The actual signal recorded with an analytical instrument is not always a true reflection of the analysed sample. In this thesis a further insight of the atmospheric pressure ionisation processes electrospray (ESI) and atmospheric pressure chemical ionisation (APCI) has been endeavoured, to provide a deeper understanding of and ways to minimize this bias. LÄS MER

5. 19. Shape and material optimization for antenna applications

   Författare :Per Jacobsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; explicit-implicit time stepping; sensitivity analysis; Nitsche s method; total scattering cross section; shape and material optimization; array antennas; finite element method;

   Sammanfattning : In this thesis, a gradient-based method for shape and material optimization fortwo antenna applications is presented: minimization of the active reflectioncoefficient for conformal array antennas; and minimization of the totalscattering cross section for cylindrical scatterers. The sensitivity of theobjective function with respect to changes of the shape and material of the geometry isexpressed in terms of the original field problem and an adjoint field problem. LÄS MER

7. 20. Design and Fabrication of III-V Semiconductor Devices for Millimetre- and Submillimetre Wave Applications

   Författare :Svein M. Nilsen; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Devices (various types of diodes) have been fabricated in several different III-V semiconductors (AlxGa1-xAs, In1-xGaxAs, and InAs). The III- V compound semiconductors lend themselves well to high frequency applications due to the high electron mobility that can be obtained. LÄS MER