<p>Spacecraft on interplanetary missions or advanced satellites orbiting the Earth all require propulsion systems to complete their missions. Introducing microelectromechanical systems technology to the space industry will not only reduce size and weight of the propulsion system, but can also increase the performance of the mission.</p><p>Fluid handling systems are used in chemical and electric propulsion. Some components incorporated in a fluidic handling system are presented and evaluated in this work.</p><p>Microsystems are very sensitive to contamination. Reliable, robust, and easily integrated filters were modeled, manufactured, and experimentally verified.</p><p>A fluid connector, designed to withstand large temperature variations and aggressive propellants was manufactured and characterized. Similar designs was also be used as a thermally activated minute valve.</p><p>The feasibility of a cold gas system for precise attitude control has been demonstrated. Steps towards improving the performance (from specific im-pulse 45 s) have been taken, by the integration of suspended heater elements.</p><p>For electric propulsion, two thermally regulated flow restrictors have been characterized. These devices can fine-tune the propellant flow to e.g. an ion engine.</p><p>A single-use valve using a soldered seal has also been successfully dem-onstrated within a pressure range of 5 to 100 bar.</p><p>The microsystem-based propulsion systems of tomorrow’s spacecraft need to be demonstrated in space, in order to gain necessary credibility. </p>

<p>Since the 1950s, oil has been the dominant source of energy in the world. The cheap supply of oil has been the engine for economic growth in the western world. Since future oil demand is expected to increase, the question to what extent future production will be available is important. </p><p>The belief in a soon peak production of oil is fueled by increasing oil prices. However, the reliability of the oil price as a single parameter can be questioned, as earlier times of high prices have occurred without having anything to do with a lack of oil. Instead, giant oil fields, the largest oil fields in the world, can be used as a parameter.</p><p>A giant oil field contains at least 500 million barrels of recoverable oil. Only 507, or 1 % of the total number of fields, are giants. Their contribution is striking: over 60 % of the 2005 production and about 65 % of the global ultimate recoverable reserve (URR). </p><p>However, giant fields are something of the past since a majority of the largest giant fields are over 50 years old and the discovery trend of less giant fields with smaller volumes is clear. A large number of the largest giant fields are found in the countries surrounding the Persian Gulf. </p><p>The domination of giant fields in global oil production confirms a concept where they govern future production. A model, based on past annual production and URR, has been developed to forecast future production from giant fields. The results, in combination with forecasts on new field developments, heavy oil and oil sand, are used to predict future oil production.</p><p>In all scenarios, peak oil occurs at about the same time as the giant fields peak. The worst-case scenario sees a peak in 2008 and the best-case scenario, following a 1.4 % demand growth, peaks in 2018.</p>

<p>The work in this thesis has demonstrated the advantages and limitations of using MS based technologies in protein and peptide structural studies. </p><p>Tandem MS, specifically electron capture dissociation (ECD) have shown the ability to provide structural insights in molecules containing the slightest of all modifications (D-AA substitution). Additionally, it can be concluded that charge localization in molecular ions is best identified with ECD and to a lesser degree using CAD. </p><p>Fragment ion abundances are a quantifiable tool providing chiral recognition (R_Chiral). An analytical model demonstrating the detection and quantification of D-AAs within proteins and peptides has been achieved. ECD has demonstrated the ability to quantify stereoisomeric mixtures to as little as 1%. Chirality elucidation on a nano LC-MS/MS time scale has been shown. </p><p>The structures of various stereoisomers of the mini protein Trp Cage were explored, each providing unique ECD fragment ion abundances suggestive of gas phase structural differences. The uniqueness of these abundances combined with MDS data have been used in proposing a new mechanism in c and z fragment ion formation in ECD. This mechanism suggests initial electron capture on a backbone amide involved in (neutral) hydrogen bonding.</p><p>The wealth of solution phase (circular dichroism), transitition phase (charge state distribution, CSD) and gas phase (ECD) data for Trp Cage suggest that at low charge states (2+) the molecule has a high degree of structural similarity in solution- and gas- phases. Furthermore, quantitative information from CSD studies is garnered when using a “native” deuteriated form as part of the stereoisomeric mixture. It has also been shown that the stability of the reduced species after electron capture is indicative of the recombination energy release, which in turn is linked to the coulombic repulsion- a structural constraint that can be used for approximation of the inter-charge distance for various stereoisomers.</p>

<p>Metal forming is widely used in the industry to produce cans, tubes, car chassis, rods, wires etc. Forming certain materials such as stainless steel, aluminium and titanium, is often difficult, and problems associated with transfer of work material to the tool material are frequent. Transferred material may scratch and deform the following manufactured pieces, a phenomenon named galling. Lubricants can, to some degree, solve these problems. However, many forming oils are hazardous to the environment, and therefore it is highly desirable to replace them or get rid of them.</p><p>This thesis investigates the nature of the galling phenomenon and tries to explain under which conditions such problems arise. Dry sliding tests have been performed in a dedicated load-scanner equipment. Difficult work materials have been tested against tool materials under various conditions and the samples have then been studied by advanced analytical techniques, such as ESCA and TEM, to study the detailed tribological mechanisms occurring in the contact between work and tool material.</p><p>The general assumption is that material transfer only occurs when there is metal to metal contact. In this work it has been found that, for stainless steel, the oxide plays a very important role for the sticky behaviour of stainless steel, and that metal to metal contact is not a necessary condition for galling.</p><p>Several PVD-coated tool materials have been tested and it was found that vanadium nitride coatings can be tuned regarding their chemical composition, to be more galling resistant than conventional coatings.</p><p>The surface roughness of the tool material is very strongly coupled to the tools ability to resist galling. The smoother the tool surface, the less risk of material transfer and galling.</p><p>Some work materials, like aluminium and titanium, transfer to even the smoothest tool materials. A proposed explanation for this is that their oxides are much harder than the bulk material and the tool material matrix. When deforming the work material, the oxide will fracture into small hard scales, which can indent the tool material. Indented hard scales will then contribute to material transfer of more work material to the tool.</p>

Production and consumption of electricity have grown enormously during the last century. No mater what the primary source of energy is, almost all generation of electricity comes from conversion of a rotational movement in a generator. The aim of this thesis is to see how high voltage technology influence production and storage of electricity. Power flow in the generators used to convert mechanical movement to electric energy is analyzed using Poynting‘s vector. The impact of new generator technology for efficient extraction of hydroelectric power is shown. Simulation of a large permanent magnet turbo generator is presented. A flywheel storage system for electric vehicles utilizing high voltage technology is also presented. In pulsed power applications, a cheap method for intermediate storage of energy during milliseconds, which enables an inductive primary storage is presented and experimentally tested.

The impact of window area on the energy balance of a building was investigated by simulations in DEROB-LTH. The glazed area was varied in three types of buildings with different types of glazing and for several climates. One low energy house was compared to a less insulated house but identical in size and layout. Three different types of glazing were used; uncoated double glazing, double glazing with one low-e coated pane and triple glazing with two low-e coated panes. Climates with variations in solar radiation, mean temperature, altitude and latitude were chosen. The results show that if energy efficient window alternatives are chosen the flexibility of choosing the glazed area and orientation is higher. Choosing a larger area facing south resulted in a higher heating demand for uncoated double glazing in the standard house. An increased area also resulted in an increased peak load for heating for all the simulated cases. Choosing the energy efficient glazing type gave a decrease in heating demand for increased south facing glazed area in the standard house. In the low energy house the difference in heating demand between different areas was smaller than for the standard house. An office module with two types of switchable glazing and one solar control glazing unit was used in three different climates; Stockholm, Brussels and Rome. Larger window areas increase the cooling demand but if glazing types with lower solar transmittance are used, the difference in cooling demand between different window areas decreases. An extremely large window area, however, increases the peak load both for cooling and for heating and should therefore be avoided. Energy can be saved by using switchable windows instead of solar control or in particular standard glazing.

Since the 1950s, oil has been the dominant source of energy in the world. The cheap supply of oil has been the engine for economic growth in the western world. Since future oil demand is expected to increase, the question to what extent future production will be available is important. The belief in a soon peak production of oil is fueled by increasing oil prices. However, the reliability of the oil price as a single parameter can be questioned, as earlier times of high prices have occurred without having anything to do with a lack of oil. Instead, giant oil fields, the largest oil fields in the world, can be used as a parameter. A giant oil field contains at least 500 million barrels of recoverable oil. Only 507, or 1 % of the total number of fields, are giants. Their contribution is striking: over 60 % of the 2005 production and about 65 % of the global ultimate recoverable reserve (URR). However, giant fields are something of the past since a majority of the largest giant fields are over 50 years old and the discovery trend of less giant fields with smaller volumes is clear. A large number of the largest giant fields are found in the countries surrounding the Persian Gulf. The domination of giant fields in global oil production confirms a concept where they govern future production. A model, based on past annual production and URR, has been developed to forecast future production from giant fields. The results, in combination with forecasts on new field developments, heavy oil and oil sand, are used to predict future oil production. In all scenarios, peak oil occurs at about the same time as the giant fields peak. The worst-case scenario sees a peak in 2008 and the best-case scenario, following a 1.4 % demand growth, peaks in 2018.

The work in this thesis has demonstrated the advantages and limitations of using MS based technologies in protein and peptide structural studies. Tandem MS, specifically electron capture dissociation (ECD) have shown the ability to provide structural insights in molecules containing the slightest of all modifications (D-AA substitution). Additionally, it can be concluded that charge localization in molecular ions is best identified with ECD and to a lesser degree using CAD. Fragment ion abundances are a quantifiable tool providing chiral recognition (RChiral). An analytical model demonstrating the detection and quantification of D-AAs within proteins and peptides has been achieved. ECD has demonstrated the ability to quantify stereoisomeric mixtures to as little as 1%. Chirality elucidation on a nano LC-MS/MS time scale has been shown. The structures of various stereoisomers of the mini protein Trp Cage were explored, each providing unique ECD fragment ion abundances suggestive of gas phase structural differences. The uniqueness of these abundances combined with MDS data have been used in proposing a new mechanism in c and z fragment ion formation in ECD. This mechanism suggests initial electron capture on a backbone amide involved in (neutral) hydrogen bonding. The wealth of solution phase (circular dichroism), transitition phase (charge state distribution, CSD) and gas phase (ECD) data for Trp Cage suggest that at low charge states (2+) the molecule has a high degree of structural similarity in solution- and gas- phases. Furthermore, quantitative information from CSD studies is garnered when using a “native” deuteriated form as part of the stereoisomeric mixture. It has also been shown that the stability of the reduced species after electron capture is indicative of the recombination energy release, which in turn is linked to the coulombic repulsion- a structural constraint that can be used for approximation of the inter-charge distance for various stereoisomers.

Metal forming is widely used in the industry to produce cans, tubes, car chassis, rods, wires etc. Forming certain materials such as stainless steel, aluminium and titanium, is often difficult, and problems associated with transfer of work material to the tool material are frequent. Transferred material may scratch and deform the following manufactured pieces, a phenomenon named galling. Lubricants can, to some degree, solve these problems. However, many forming oils are hazardous to the environment, and therefore it is highly desirable to replace them or get rid of them. This thesis investigates the nature of the galling phenomenon and tries to explain under which conditions such problems arise. Dry sliding tests have been performed in a dedicated load-scanner equipment. Difficult work materials have been tested against tool materials under various conditions and the samples have then been studied by advanced analytical techniques, such as ESCA and TEM, to study the detailed tribological mechanisms occurring in the contact between work and tool material. The general assumption is that material transfer only occurs when there is metal to metal contact. In this work it has been found that, for stainless steel, the oxide plays a very important role for the sticky behaviour of stainless steel, and that metal to metal contact is not a necessary condition for galling. Several PVD-coated tool materials have been tested and it was found that vanadium nitride coatings can be tuned regarding their chemical composition, to be more galling resistant than conventional coatings. The surface roughness of the tool material is very strongly coupled to the tools ability to resist galling. The smoother the tool surface, the less risk of material transfer and galling. Some work materials, like aluminium and titanium, transfer to even the smoothest tool materials. A proposed explanation for this is that their oxides are much harder than the bulk material and the tool material matrix. When deforming the work material, the oxide will fracture into small hard scales, which can indent the tool material. Indented hard scales will then contribute to material transfer of more work material to the tool.

At the University Hospital of Umeå, NUS, a new radiation treatment department is being built. The purpose of this master thesis is to evaluate the actual radiation protection outside three out of five treatment rooms in the building, including two Varian and one Siemens accelerator, and to verify that the radiation limits for the staff and the general public, stated by the Swedish Radiation Safety Authority, are obeyed. The evaluation of the radiation protection shielding is made through measurements. The nominal photon beam energies 6 and 15 MV (dose rates up to 500 MU/min) can be used, which means that both photons and neutrons will contribute to the effective dose. For the photon measurements, two different GM counters have been used and for the neutron measurements a Neutron detector with a polyethylene moderator and a 3He recoil proton counter tube was applied. The thesis also includes a literature study of the photon and neutron energy spectra outside the treatment rooms in order to check that the measurement equipments are suitable to use. The measured doses of the radiation shielding are below the radiation limits per week and year but the measurements indicate too high values per hour, i.e. momentary dose rate, at the height of isocenter of the primary walls and at the gap under the door for all three accelerators. The rooms with the Varian accelerators also show too high values per hour at the secondary wall where the door is attached. However, the limiting value per hour is only a recommendation and no extra reinforcement in therefore required. Nevertheless, one should avoid placing a workplace, for example a writing desk, close to the secondary and primary walls.