Popular Abstract in Swedish Denna studie är ämnad åt att undersöka joniseringsprocessen i gaser, både teoretiskt och experimentellt. Arbetet är speciellt riktat mot att utöka förståelsen för detta fenomen i förbränningsrummet av en förbränningsmotor. Den intensiva joniseringsprocessen som uppstår till följd av den antändande gnistan har studerats såväl som den svagare joniseringsprocessen som är rThe processes that govern the formation, existence and consumption of ions in gases have been studied both experimentally and theoretically. The aim of the work is targeted at increasing the understanding of these phenomena in the working gases inside an engine. Both the cause and the application of ionized gases inside the cylinder of a spark ignited (SI) engine has been studied. The spark disch

The contribution of this paper is a time-frequency domain speech presence detection method that classifies power bins in the time-frequency domain as containing speech or not. An initial decision rule is based on ratios between optimally time-smoothed signal-plus-noise periodograms and weighted noise periodogram estimates, obtained from minimum statistics as proposed by Martin [1]. The initial dec

Background Ligands of peroxisome proliferator-activated receptor alpha (PPAR-alpha) have been shown to reduce ischaemia/reperfusion injury. The mechanisms behind this effect are not well known. We hypothesized that activation of PPAR-alpha exerts cardioprotection via a mechanism related to nitric oxide (NO) and endothelin-1 (ET-1). Methods Five groups of anaesthetized open-chest Sprague-Dawley rat

An increased prevalence of asthma in cross-country skiers has been reported previously. This study was conducted in order to evaluate the prevalence of asthma among young, elite cross-country skiers in Trondelag, Norway and Jamtland, Sweden. These two regions in central Scandinavia have different climates during the winter season, with a coastal type in Trondelag while Jamtland is characterized by

An intramolecular NEMO potential is presented for the N-formylglycinamide molecule together with an intermolecular potential for the N-formylglycinamide-water system. The intramolecular N-formylglycinamide potential can be used as a building block for the backbone of polypeptides and proteins. Two intramolecular minima have been obtained. One, denoted as C5, is stabilized by a hydrogen bonded five

Alphavirus glycoproteins have broad host ranges. Human immunodeficiency virus type 1 (HIV-1) vectors pseudotyped with their glycoproteins could extend the range of tissues that can be transduced in both humans and animal models. Here, we established stable producer cell lines for HIV vectors pseudotyped with alphavirus Ross River virus (RRV) and Semliki Forest virus (SFV) glycoproteins E2E1. RRV E

The main concern of this thesis is to experimentally investigate the turbulent flow and heat transfer in a ribbed channel. Such flows are encountered in many engineering applications, e.g., gas turbine cooling. In order to highlight the physical mechanism of flow separation, only one wall of the channel is fitted with periodic ribs. The inter-rib spacing is set such that the reattachment is allowe

Objective: Interstitial laser coagulation (ILC) of the prostate is a minimally invasive method for treating symptomatic benign prostatic enlargement (BPE). We performed a prospective randomized study to compare the clinical outcomes of ILC and transurethral resection of the prostate (TURP). Material and Methods: Between December 1997 and February 2000, 38 patients with moderate-to-severe symptomat

The exclusive H-2 (He-3, t)2p reaction has been studied at 2 GeV for energy transfers up to 500 MeV and triton angles up to 3.4degrees. The protons were measured in the large acceptance magnetic detector DIOGENE, in coincidence with the forward tritons detected in a dedicated magnetic arm. The energy transfer spectra extend well above the pion threshold. However, in the region of Delta excitation,

A rapid and sensitive assay was developed for the detection of amphetamine in plasma and urine. The method relies on the principle of competitive ELISA (enzyme-linked immunosorbent assay). A flow microchip with a total volume of 7 µL was used for the development of a chemiluminescent ELISA technique. Solutions, samples, and the chemiluminescence substrate were injected by a flow system, and a phot

OBJECTIVE - To study cross-sectional associations of dietary fiber intake with insulin resistance, insulin secretion, and glucose tolerance in a population at high risk for type 2 diabetes. RESEARCH DESIGN AND METHODS - The subjects consisted of 248 male and 304 female adult nondiabetic relatives of patients with type 2 diabetes. Dietary intake was measured by means of two 3-day food records. Asso

Calcareous soils are frequently characterized by the low bioavailability of plant nutrients. Consequently, many vascular plant species are unable to successfully colonize calcareous sites and the floristic composition of calcareous and acid silicate soils has been shown to differ markedly. The root exudation of oxalate and citrate has been suggested to play a pivotal role in same nutrient acquisit

Objective: This paper analyzes some of the problems with error counting as well as the difficulty of proposing viable alternatives. Background: Counting and tabulating negatives (e.g., errors) are currently popular ways to measure and help improve safety in a variety of domains. They uphold an illusion of rationality and control but may offer neither real insight nor productive routes for improvin

Modelling the temperature dynamics of a district heating system is typically validated for a single pipe or a system with limited information about dynamic consumer behaviour. In the present work, time dependent consumer data from the Naestved district heating system was used to investigate the ability of modelling tools to represent the temperature profile distortion throughout an entire heating

The possibility of using carriers made of recycled glass in anaerobic packed bed reactors has been studied in laboratory-scale experiments. Two types of carrier were studied: a porous bead of glass foam and an open ring of a smoother, sintered glass. The performance of processes with these carriers was compared with a conventional upflow anaerobic sludge blanket (UASB) process. The treatment of wa