Sökning: "total pressure"

Visar resultat 26 - 30 av 600 avhandlingar innehållade orden total pressure.

1. 26. Cerebral blood flow and intracranial pulsatility studied with MRI : measurement, physiological and pathophysiological aspects

   Författare :Anders Wåhlin; Anders Eklund; Jan Malm; Richard Birgander; William G Bradley; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Arterial Pulsatility; cerebrospinal fluid; cerebral blood flow; venous flow; intracranial pressure; pulse pressure; dementia; hippocampus; multiple sclerosis; magnetic resonance imaging; radiofysik; radiation physics;

   Sammanfattning : During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. LÄS MER

3. 27. Pulmonary Atelectasis in General Anaesthesia : Clinical Studies on the Counteracting Effects of Positive End-Expiratory Pressure

   Författare :Erland Östberg; Mats Enlund; Lennart Edmark; Sophie Lindgren; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; General anaesthesia; pulmonary atelectasis; positive end-expiratory pressure; oxygen; computed tomography; continuous positive airway pressure; mechanical ventilation; Anestesiologi och intensivvård; Anaesthesiology and Intensive Care;

   Sammanfattning : Partial lung collapse, i.e., pulmonary atelectasis, is common during general anaesthesia. The main causal mechanism is reduced lung volume with airway closure and subsequent gas absorption from preoxygenated alveoli. LÄS MER

4. 28. Variability of blood pressure and heart rate in borderline and mild hypertension : With special reference to spectral analysis

   Författare :Reijo Takalo; Uppsala universitet; []
   Nyckelord :Medical sciences; hypertension; blood pressure; ambulatory monitoring; power spectrum analysis; pulsecontour method; systemic hemodynamics; MEDICIN OCH VÅRD; MEDICINE; MEDICIN; Clinical Physiology; klinisk fysiologi;

   Sammanfattning : The aim of this thesis was to study whether blood pressure (BP) or heart rate (HR) variability in borderline (BHT) and hypertensive (HT) subjects differs from that in normotensive (NT) subjects, and whether indices for BP and HR variability can be used in risk stratification for future hypertension. The study groups consisted of 35 NT, 29 BHT, and 34 HT middle-aged men. LÄS MER

5. 29. The Karma of Products : Exploring the Causality of Environmental Pressure with Causal Loop Diagram and Environmental Footprint

   Författare :Rafael Laurenti; Björn Frostell; Andrius Plepys; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Products; Environmental Pressure; Causal Loop Diagram; Environmental Footprint; Industrial Ecology; Industriell ekologi;

   Sammanfattning : Environmental pressures from consumer products and mechanisms of predetermination were examined in this thesis using causal loop diagram (CLD) and life cycle assessment (LCA) footprinting to respectively illustrate and provide some indicators about these mechanisms. Theoretical arguments and their practical implications were subjected to qualitative and quantitative analysis, using secondary and primary data. LÄS MER

7. 30. Prediction of Cooling Air Flow in Electric Generators

   Författare :Pirooz Moradnia; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Multiple Reference Frame; PIV; Total Pressure Measurements; Electric Generator; Experimental Measurements; 5-hole Pressure Probe Measurements; Flow Prediction; OpenFOAM;

   Sammanfattning : The cooling air flow in hydro power electric generators is investigated experimentally and numerically. A fully predictive numerical approach is presented and validated, in which the inlet and outlet boundaries are eliminated from the computational domain. LÄS MER