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The aim of this work was to investigate the dosimetric effects of removing the flattening filter from conventional C-arm medical linear accelerators. In conventional linear accelerators used for radiotherapy, a flattening filter is positioned in the beam line to provide a uniform lateral dose profile at a specified depth in water. However, for some radiotherapy treatments, a uniform lateral dose p
How are access to asylum and other forms of extraterritorial protection regulated in the European Union? Is the EU acquis in these areas in conformity with international law? What tools does international law offer to solve conflicts between them? And, finally, is law capable of bridging the foundational oppositions embedded in migration and asylum issues? This work combines the potential of legal
The current form-giving activity in industrial design is characterized by explorations that depend on the individual capability to mentally manipulate a solution space from which to select and express the intended result. Industrial designers frequently rely on artistic experimentation, aesthetic inspiration, or design briefs. These points of departure often result in satisfactory results, but the
In the last two decades, phase-contrast magnetic resonance imaging (PC-MRI) has evolved from two-dimensional velocity and flow measurements to volumetric, time-resolved depictions of velocity fields (4D PC). The acquisition of time-resolved velocity fields allows flow visualisations that might provide better understanding of the dynamics of the cardiac system. Because 4D PC is increasingly being u
In the normal functioning organism, there is a balance between cell proliferation, cell differentiation, and cell death. An imbalance in these processes results in different diseases. This thesis concerns the imbalance where there is too little cell death and cell differentiation with increased cell proliferation. The result is uncontrolled cell proliferation resulting in the development of cancer
This dissertation discusses the personal implications of the early consequences of rheumatoid arthritis, how they effect the person's working life and how they are dealt with. In this qualitative study thematized interviews are used. Twenty-three persons, recently diagnosed with rheumatoid arthritis, were interviewed twice, two years apart. The study is influenced by an interactionist perspective
The role of stochasticity throughout many biophysical systems is of great importance. From evolution to foraging, from the spreading of viruses to cell fate, all hinge in one way or another on inherent stochasticity. The aim of this thesis is to explore the tools often used to quantify randomness in nature, and employ these tools on a selected range of biophysical systems (Papers I-IV). In these p
Helicobacter pylori is a human pathogen strongly associated with chronic type B gastritis, peptic ulcer disease, gastric cancer and MALT lymphoma. Our aims were to establish a mouse model of H. pylori infection, to study pathogenesis of gastritis and gastric cancer and to investigate new treatment strategies in this model. Both spiral and coccoid forms of H. pylori strains 17874, 25 and 553/93 cau
Tortuguero National Park in Costa Rica hosts nesting by four species of highly migratory and endangered sea turtles (green, hawksbill, leatherback and loggerhead turtles). Sea turtle research at Tortuguero has been continuous since Dr. Archie Carr began studies in the 1950?s. This dissertation aims to clarify the Tortuguero sea turtles? post-nesting migrations, nesting trends and survival threats.
This book attempts to answer the question of how it is possible that Christianity in the beginning of the second century C.E. had developed into a non-Jewish, Gentile religion. Since Christianity was originally one of many Jewish factions within the diversified Judaism of the period, and one that even primarily seems to have directed its attention to the people of Israel, the problem of its separa
The crystalline properties of starch constitutes a puzzling area of research. Our understanding of the crystalline structure of amylopectin, that is the crystalline component in starch, is based on the observations from investigations on modified amylose. The first part of this thesis includes a discussion of the unit cells (the smallest crystalline units) suggested in the literature. The differen
A continuing use of fossil fuels will accelerate global warning and result in severe consequences for the environment and thereby also us. Development of alternative, sustainable and environmentally friendly energy sources is therefore crucial. One approach is to create an artificial photosynthetic system that converts sunshine into fuel (e.g. hydrogen gas) by splitting water molecules. However, i
The modification of drugs into pro-drugs is an attractive concept allowing you to tweak the chemical and physical properties of a drug without changing the original structure of the active compound. In principle, any compound possessing a preferred biological activity can be transformed into a pro-drug. Many natural products harbor qualities that are potentially interesting as drugs but difficult
This thesis focuses on the electromagnetic design of a synchronous machine suited for a belt-driven alternator and starter (BAS) in a micro hybridisation of a mid-size passenger car. The BAS needs to provide a high cranking torque to start the combustion engine, especially in a cool condition where the requirements are highest. Besides the high cranking torque it is desirable to have high power pe
The aromatic isocyanates, toluene diisocyanate (TDI) and methylenediphenyl diisocyanate (MDI), are used in the production of polyurethane (PUR) foams, paints, elastomers and glues. The use of isocyanates is increasing, and exposure to isocyanates is the most common cause of occupational asthma. Biomarkers of TDI and MDI were determined as the corresponding amines, toluenediamine (TDA) and methyle
A measurement of the reactions 16O(γ,p)15N and 18O(γ,p)17N have been made with tagged photons in the energy range Eγ ≈ 50 – 70 MeV. The protons have been detected in ΔE-E telescopes with silicon strip detectors as ΔE detectors and HPGe crystals as E detectors. Two telescopes have been used with an average angle towards the photon beam of 70 and 110 degrees. The silicon strip detectors have been us
Gel dosimetry was used together with magnetic resonance imaging (MRI) to measure three-dimensional absorbed dose distributions in radiation therapy. Two different dosimeters were studied: ferrous- and monomer gel, based on the principles of radiation-induced oxidation and polymerisation, respectively. Single clinical electron and photon beams were evaluated and gel dose distributions were mainly w
In this study, the fundamental mass and heat transfer properties of the membrane separation process called pervaporation were investigated. The suitability of pervaporation for aroma compound recovery was especially evaluated. The mass transfer in pervaporation is affected by an external mass transfer resistance in the liquid feed boundary layer, i.e. the concentration polarization phenomenon. Th
Firms compete with each other to earn the highest profit. A wide range of issues needs to be considered in order to do so – decisions about products, markets, customers and, not to forget, organisation have to be made. Concerning organisation, a business firm can choose to make a particular thing (a good or service) by itself or to buy it from someone else. The decision determines the way in which
