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Radio Frequency Systems for NMR Imaging: Coil Development and Studies of Non-Thermal Biological Effects

This thesis concerns both design and optimization of NMR imaging systems and studies on non-thermal biological effects of electromagnetic fields. These two research fields are linked together by the fact that humans are subject to static and pulsed magnetic fields as well as to magnetic radio frequency fields (RF) during an NMR imaging investigation. This work bridges the gap between technology, p

Development of Laser-Induced Fluorescence for Precombustion Diagnostics in Spark-Ignition Engines

Motivated by a desire to understand and optimize combustion in spark-ignition (SI) engines, laser techniques have been developed for measurement of fuel and residual gas, respectively, in the precombustion mixture of an operating SI engine. The primary objective was to obtain two-dimensional, quantitative data in the vicinity of the spark gap at the time of ignition. A laser-induced fluorescence

Limitations on Control System Performance

Many different factors such as process dynamics, disturbances, process uncertainties and actuator saturation have to be considered when designing a control system. It is important to be aware of factors that limits the achievable performance. In this paper we attempt to formulate some problems that capture the essence of the design problem in a simple way. Results of this type are a complement to

Comparison of dose calculation algorithms in slab phantoms with cortical bone equivalent heterogeneities

To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect tr

The European Respiratory Society study on chronic obstructive pulmonary disease (EUROSCOP): recruitment methods and strategies

The European Respiratory Society's study on chronic obstructive pulmonary disease (EUROSCOP) is a multicentre study performed initially in 12 countries to assess the effect of 3 years' treatment with inhaled corticosteroids on lung function decline in smokers with chronic obstructive pulmonary disease (COPD). It aimed at recruiting 50 subjects in 50 European centres. This study discusses the most

Participant observation in logistics research: Experiences from an RFID implementation study

Purpose – The purpose is to describe the advantages, challenges and uncertainties of collecting and analyzing data using participant observation in logistics research. Design/methodology/approach – Experiences from a participant observation study of an interorganizational RFID implementation in an international environment are presented and reflected on. The RFID implementation included complex in

Structure of wobbling excitations in Lu-163

Using a many-particles plus rotor model, wobbling excitations built on top of a triaxial superdeformed band in Lu-163 are investigated. By extracting all parameters for the rotor from a mean field calculation a good correspondence with calculations based on the random-phase approximation is achieved.

Cost/benefit aspects on thromboprophylaxis

Several studies have shown thromboprophylaxis of any kind to be more cost-effective than no prophylaxis or general diagnostic surveillance and selective treatment. Little has been written on low molecular weight heparins from the cost-effectiveness point of view. This preliminary study shows low molecular weight heparin to be more cost-effective than standard low-dose heparin in most situations of

On the experimental validation of a non-linear shaft damping model

This paper presents an experimental validation of a proposed non-linear damping model for shaft torsional vibration studies, compared to the linear viscous damping model. Nine different shaft configurations were used. The deflection of each shaft exhibiting free vibration was measured for a period of one minute and the signal component at the natural frequency of torsion was found. The experiments

Sulfonylurea-Mediated Stimulation of Insulin Exocytosis via an ATP-Sensitive K(+) Channel--Independent Action.

Several reports indicate that hypoglycemic sulfonylureas augment Ca(2+)-dependent insulin secretion via mechanisms other than inhibition of the ATP-sensitive K(+) channel. The effect involves a 65-kd protein in the granule membrane and culminates in intragranular acidification. Lowering of granule pH is necessary for the insulin granule to gain release competence. Proton pumping into the granule i

Two chromones from Peperomia vulcanica

Two chromones: 5-hydroxy-2-(14'-(E)-nonadecenyl) chromone (1) and 5-hydroxy-2-[12'-(3",4"-methylenedioxyphenyl)dodecanyl] chromone (2), together with six known compounds have been isolated from Peperomia vulcanica Baker & C. H. Wright (Piperaceae). Their structures were determined by spectroscopic analysis including 2D NMR techniques.