Search for dissertations about: "GTD"

Showing result 6 - 9 of 9 swedish dissertations containing the word GTD.

2. 6. Elastic Wave Scattering by Cracks - Interfacial Forces and High Frequency Diffraction

   Author : Gert Persson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic testing; Wiener-Hopf calculations; Geometrical Theory of Diffraction; edge diffracted body waves; PEDGE; two-dimensional diffraction; geometrical elastodynamic waves;

   Abstract : This thesis treats elastic wave scattering by cracks with interfacial forces. The results are of practical interest in ultrasonic testing and includes development of numerical methods used to predict such testing. First the canonical problem of two-dimensional (2-D) diffraction from a semi-infinite crack is solved. READ MORE

4. 7. Thin Layers in Elastic Wave Propagation -Effective Modelling and Diffraction

   Author : Peter Bövik; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Geometrical Theory of Diffraction; elastic wave scattering; shear waves; Wienr-Hopf method; L-TV waves; applications;

   Abstract : In the present thesis, the interest is focussed on the problem of effective modelling of thin interface layers for applications in elastic wave scattering. The layers are considered to be thin compared with wavelengths involved and it is shown that when all effects to lowest order in the layer thickness are included, we get boundary conditions (BCs) which have a number of nice features, including the one of implying that no scattering occurs when the layer has material parameters identical to the ones in the matrix medium. READ MORE

5. 8. Ultrasonic NDT in Defect Detection - Mathematical modelling

   Author : Håkan Wirdelius; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack; null field approach; transducers; optimisation; ultrasonics; elastic waves; nondestructive testing; T matrix method; inverse problem;

   Abstract : This thesis is concerned with the mathematical modelling of the ultrasonic nondestructive testing situation. The first part of the thesis treats a simplified model of an ultrasonic transducer and its implementation into a T-matrix method-based solution to a crack scattering problem. READ MORE

6. 9. Cooperative Reactive Sites in Designed Helix-Loop-Helix Polypeptide Catalysts

   Author : Jonas W. Nilsson; Paolo Scrimin; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Designed polypeptides, which fold into helix-loop-helix motifs and dimerise to four-helix bundles have been used as scaffolds for the introduction of catalytic activity for the hydrolysis of p-nitrophenyl esters. The reactive sites were based on the reactivity of histidine, and two His residues separated by four residues in the sequence was shown to be the minimal reactive site for the efficient hydrolysis of nitrophenyl esters. READ MORE