Two types of glassy carbon (GC) powder (i.e., Sigradur K and Sigradur G) have been mixed with mineral oil to obtain glassy carbon paste electrodes (GCPE's). The electrochemical behavior of such electrodes at different percentages of glassy carbon has been evaluated with respect to the electrochemistry of ferricyanide as revealed with cyclic voltammetry and the best paste composition was chosen. GC

Popular Abstract in Swedish I denna avhandling studeras en resonant omvandlare. Detta är en elektrisk krets som amvandlar likspänningar från en nivå till en annan. För att styra detta system, måste man förstå dess egenskaper. Min uppgift har varit att undersöka huruvida systemet innehåller s.k. gränscykler (självsvängningar) respektive chattering (extremt snabba självsvängningar). Vissa av dessa gIn this thesis existence and uniqueness of limit cycles are shown for a resonant converter, by extending Poincaré-Bendixson theory to non-smooth vector fields. We discuss relevant control theory and the role of simulations.

Can a deliberate enhancement of the natural uptake of atmospheric carbon dioxide in forests and agricultural lands contribute to the efforts to mitigation anthropogenic climate change? This is a question that has generated a great deal of debate and controversy since the inception of the multilateral climate negotiations in the early 1990s. This thesis offers an analysis of how this debate has pla

The Extracting Syringe (ESy), a novel membrane-based sample preparation technique directly coupled as an autosampler to gas chromatography, has been employed for the analysis of organochlorine pesticides (OCPs) in raw leachate water. The ESy has also been applied for extraction of OCPs from contaminated soil samples and its performance has been compared to liquid-solid extraction (LSE) and acceler

How can tools help structure tasks to make them cognitively easier to perform? How do artefacts, and our strategies for using them, develop over time in cognitively beneficial ways? These are two of the main questions that are explored in the five papers collected in this thesis. The first paper details an ethnographic study conducted on people cooking in their homes. The study is a first pass ov

The analysis of general charge sampling technique is presented in this thesis. Charge sampling integrates input current instead of tracking input voltage to realize high speed and low voltage sampling. The analysis focuses on the performance of general charge sampling circuits for signal capture. The theoretical analysis here can be applied not only for the weak signal capture, but also for the no

Background: Two heterologous pathways have been used to construct recombinant xylose-fermenting Saccharomyces cerevisiae strains: i) the xylose reductase ( XR) and xylitol dehydrogenase (XDH) pathway and ii) the xylose isomerase (XI) pathway. In the present study, the Pichia stipitis XR-XDH pathway and the Piromyces XI pathway were compared in an isogenic strain background, using a laboratory host

The article discusses the role of language in conceptualising national identity in ethnonationalist Ukrainophone discourse. It especially focuses on attitudes to the Ukrainian-Russian contact variety surzhyk.

Mechanisms controlling microbial degradation of dissolved organic matter (DOM) in aquatic environments are poorly understood, although microbes are crucial to global nutrient cycling. Bacterial cell wall components may be one of the keys in understanding the presence of slowly degrading DOM in nature. We found that dominant components of bacterial cell walls (D-amino acids (D-AA), glucosamine (Glu

Plants of the partially self-incompatible perennial herb Brassica cretica, derived from contralled cross- and self-pollinations within each of seven populations, were raised under uniform conditions and scored for two measures of developmental stability, flower asymmetry (quantified as the difference in length and width between opposite petals) and cotyledon asymmetry (quantified as the difference

The importance of screening programs in reducing the prevalence of genital chlamydial infections is stressed by the fact that the majority of infected persons are more or less asymptomatic. The use of oral contraceptives may mask infections affecting the upper genital tract. This imposes selective screening and rescreening of women with a history of pelvic inflammatory disease. The recent knowledg

Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic beta cell destruction involving auto-reactive T-cells, pro-inflammatory cytokines, reactive oxygen species (ROS) and loss of insulin. Monozygotic twin studies show a 20-60% concordance with T1D indicating there may be an environmental component to the disease. Glutathione (GSH) is the major endogenous antioxidant produced b