Search for dissertations about: "Vbg"

Showing result 1 - 5 of 10 swedish dissertations containing the word Vbg.

  2. 1. Thermal properties of volume Bragg gratings and its implications on lasers

    Author : Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Mohamed Bourennane; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Thermal effects; Volume Bragg Gratings; VBG; Lasers;

    Abstract : This thesis contains the results of research on the spectral control of lasers, specifically, the thermal limitations of volume Bragg gratings (VBGs), employed as laser-cavity end mirrors. The investigations consisted of both experiments and numerical simulations. READ MORE

  4. 2. Properties of Volume Bragg Gratings and Nonlinear Crystals for Laser Engineering

    Author : Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Takunori Taira; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; volume Bragg grating; VBG; thermal effects; nonlinear optics; KTiOPO4; quasi-phase matching; photochromic damage; grey-tracking; color centers; blue-light induced infrared absorption; BLIIRA; Physics; Fysik;

    Abstract : This thesis focuses on two topics: thermal limitations of volume Bragg gratings (VBGs) employed as laser-cavity mirrors and formation of color centers in KTiOPO4 and its isomorphs.To explore the mechanisms of the thermal limitations of VBGs in high power lasers, I designed and constructed a diode-pumped, solid‑state laser with a VBG as cavity mirror that had a significantly higher absorption than what is typical. READ MORE

  5. 3. Roux-en-Y gastric bypass - clinical outcome and mechanisms of action

    Author : Malin Werling; Göteborgs universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Roux-en-Y gastric bypass; Obesity; Bariatric surgery; Energy chamber; Gastrointestinal hormones; GLP-1; PYY; Ghrelin; Energy expenditure; Body composition; Vertical Banded Gastroplasty; Indirect calorimetry; Overweight treatment; Weight loss;

    Abstract : Roux-en-Y gastric bypass (gastric bypass) is an effective surgical technique for treating morbid obesity. The objective of this thesis is to increase knowledge of long-term outcomes of gastric bypass surgery and to elucidate some of the associated mechanisms of action. READ MORE

  6. 4. Aspects of surgical treatment of morbid obesity : Clinical studies

    Author : Agneta Westling; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Surgery; obesity surgey; silicone adjustable gastric banding; band erosion; revision to RYGBP; laparoscopic RYGBP; deep venous thrombosis; depp venous insufficiency; Kirurgi; Surgery; Kirurgi; Surgery; kirurgi;

    Abstract : Common methods used for surgical treatment of morbid obesity are silicone adjustable gastric banding (SAGB), vertical banded gastroplasty (VBG) and Roux-en-Y gastric bypass (RYGBP). The role of laparoscopy in complex bariatric procedures such as RYGBP is unclear. READ MORE

  7. 5. Intestinal adaption in response to Roux-en-Y gastric bypass surgery

    Author : Erik Elias; Göteborgs universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; obesity; bariatric surgery; proteomic analysis; intestinal permeability; calcium; bone mineral density; lipid metabolism;

    Abstract : ABSTRACT Background: Obesity is a condition with increasing prevalence that leads to morbidity, decreased quality of life and reduced life expectancy. The only effective evidence-based treatment is bariatric surgery. READ MORE