Sökning: "Three-dimensional"

Visar resultat 6 - 10 av 1393 avhandlingar innehållade ordet Three-dimensional.

1. 6. Three-dimensional Finite Element Computation of Eddy Currents in Synchronous Machines

   Författare :Marguerite Touma Holmberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronous machines; finite element method; eddy currents; three-dimensional;

   Sammanfattning : The thesis deals with the computation of eddy-current losses in the end regions of synchronous machines. Various magnetic and electric vector potential formulations of three-dimensional eddy-current problems are investigated. The equations are discretized by the finite element method with nodal or edge finite elements. LÄS MER

3. 7. Three-Dimensional Computation of Eddy Currents in End regions of Synchronous Generators

   Författare :Marguerite Touma; Sonja Lundmark; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anisotropic; non-linear; conductor; eddy current; formulation; coil; source; saturated; finite element method; turbogenerator; three-dimensional; potential; laminated; steady state; hydrogenerator; winding;

   Sammanfattning : .... LÄS MER

4. 8. Three-dimensional ultrasound studies of normal and abnormal ovaries

   Författare :Ligita Jokubkiene; gynekologisk och prenatal ultraljudsdiagnostik Obstetrisk; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ovary; ovarian follicle; ovarian neoplasms; ultrasonography; three-dimensional imaging; Doppler ultrasound imaging; vascular morphology;

   Sammanfattning : The aims of this work were: 1) to estimate the number of follicles, ovarian volume and power Doppler vascular indices and their changes with age using three-dimensional (3D) transvaginal grey-scale and power Doppler ultrasound in asymptomatic women of fertile age either with natural menstrual cycles or using combined oral contraceptives, and 2) to determine whether tumour vascularity, assessed by 3D power Doppler ultrasound, can help discriminate between benign and malignant ovarian tumours. A group of 303 gynaecologically asymptomatic women, aged 20–39 years with normal menstrual cycles (NMC) and another group of 213 women aged 20–39 years using combined oral contraceptives (COC) were examined using two-dimensional (2D) and 3D transvaginal ultrasound once between cycle day 4 and 8. LÄS MER

5. 9. Three - dimensional ultrasound studies of the cervix in pregnancy

   Författare :Linas Rovas; Malmö Institutionen för kliniska vetenskaper; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; andrology; gynaecology; Obstetrics; Prostaglandin .; Labor induction .; Spontaneous delivery .; Pregnancy .; Cervix uteri .; Blood flow indices .; Doppler ultrasound .; Three-dimensional imaging .; sexuality; reproduction; Obstetrik; sexualitet; reproduktion; gynekologi; andrologi;

   Sammanfattning : The aim of this thesis was to evaluate cervical physiological changes by three-dimensional (3D) ultrasound during pregnancy and to investigate the ability of 3D power Doppler to predict time to spontaneous and induced delivery in prolonged pregnancy. The thesis is based on five studies: reproducibility of cervical measurements by 3D power Doppler ultrasound (study I), reference data representative normal findings of the cervix assessed by 3D ultrasound during pregnancy (studies II, III) and the ability of 3D power Doppler to predict time to spontaneous and induced delivery in prolonged pregnancy. LÄS MER

7. 10. Stability and Receptivity of Three-Dimensional Boundary Layers

   Författare :David Tempelmann; Dan Henningson; Stefan Hein; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; stability; optimal growth; three-dimensional boundary layers; parabolised stability equations; adjoint PSE; crossflow instability; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : The stability and the receptivity of three-dimensional flat plate boundary layers is studied employing parabolised stability equations. These allow for computationally efficient parametric studies. Two different sets of equations are used. LÄS MER