Preservation of cells and tissues by freezing at temperatures below 70°C has led to new possibilities for the storage of germ cells for fertility preservation. During the freezing process problems might occur, the greatest being ice crystallization which can cause membrane destruction and thus cell death. To minimize this risk, solutions that reduce the freezing point can be added to reduce crystallization and increase survival rates. These solutions are called cryoprotectants. The best method for freezing is still not known.The aim of this study was to analyze the effect of various parameters on the survival rate of human semen frozen with liquid nitrogen.

AbstractThis degree thesis was made in cooperation with Chematur Engineering in Karlskoga.Many of the environmental issues of today are a result of the motor traffic. Consumption of fossil fuels harms our environmental through formation of carbon dioxide and other greenhouse gases. To get under control with our environmental issues it?s important to find substitutes for oil that are both cheap and environmentally friendly. Ethanol has a long history as a motor fuel and is both enviromentally friendly has a high efficiency.According to the EU commissions directives for motor fuels, 5, 75 % of all the fuels in Sweden should be renewable in 2010.

This thesis is divided into two parts. Part one contains a general description of the flexographic printingtechnique. Part two contains a more detailed investigation in the areas substrate, inktransfer and trends, which are only briefly commented in part one, and conclusions and comments.The major problem concerning substrate is washboard. This phenomena can be limited if one can control and minimize the amount of glue applied in the single- and double facer, use high surface weight on liner, use low surfaceweight on fluting and control the humidity during the conditioning of the corrugated board. Corrugated board with a smooth surface radically increases the quality in print.

A recommendation for stand treatment of lodgepole pine (Pinus contorta) is, in a scientific point of view, lacking when it comes to harvesting for biomass energy. Within the next decades it is expected that 280 000 hectares of lodgepole pine will have reached thinning age on the domains of Svenska Cellulosa Aktiebolaget (SCA). Due to this the interest has grown rapidly for studying the possibilities of harvesting biofuel assortments already in the first thinning. In this study the distribution of the biomass within lodgepole pine trees has been studied and taken into account for estimating the proportions of harvested assortments when using different methods of thinning. The methods studied were conventional biofuel-harvesting (with delimbed branches gathered separately from the round wood) and thinning with cutting of round wood and long tops (incl.

With higher prices for oil and increased focus on fossil fuels impact on the environment the heating sector are searching for alternative fuels. Pellets are a quite new product whose production has risen exponential in recent years. Today there are small-, medium-and large-scale users, where the large-scale consumers are the heating sector. The heating sector is mainly using oil to cover the increased demand during cold periods. The purpose of this study is to analyze the potential of pellets if it would replace thermal power plants oil and coal. The study will also analyze the economic impact a conversion would mean for a heating plant and if the pellet is a reasonable substitute. 2008 statistics from the Swedish district heating association were analyzed and a calculation was performed to determine how many tons of pellets is needed to replace coal and oil.

The purpose of the house which is the basis of this report is to be able present itself on the market as a relatively cheap and at the same time a climate friendly choice. The house is supposed to be able to be built anywhere in Sweden and the rest of Scandinavia in a short period of time. This puts demand on what kind of heating system the house can have, since not all places have the geographic advantage of being able to use geothermal or district heating. Therefore the heating system choices will only include those that are not limited by their geographic location. The house will be built in modules which only require the groundwork to be done before the house can be erected. In this report "System solutions for plus or passive-housing" a comprehensive literature search has been conducted as well as a number of calculations.

This thesis is divided into two parts. Part one contains a general description of the flexographic printingtechnique. Part two contains a more detailed investigation in the areas substrate, inktransfer and trends, which are only briefly commented in part one, and conclusions and comments.The major problem concerning substrate is washboard. This phenomena can be limited if one can control and minimize the amount of glue applied in the single- and double facer, use high surface weight on liner, use low surfaceweight on fluting and control the humidity during the conditioning of the corrugated board. Corrugated board with a smooth surface radically increases the quality in print.

This thesis is divided into two parts. Part one contains a general description of the flexographic printingtechnique. Part two contains a more detailed investigation in the areas substrate, inktransfer and trends, which are only briefly commented in part one, and conclusions and comments.The major problem concerning substrate is washboard. This phenomena can be limited if one can control and minimize the amount of glue applied in the single- and double facer, use high surface weight on liner, use low surfaceweight on fluting and control the humidity during the conditioning of the corrugated board. Corrugated board with a smooth surface radically increases the quality in print.

Pyometra, chronic purulent metritis in metoestrus, is a common disease in intact bitches. About 25% of all bitches in Sweden have contracted the disease before ten years of age. Clinical signs of the disease are varied, and the course may be either slow or acute. The diagnosis is most commonly made by radiographical or ultrasonographical examination of the abdomen in combination with blood biochemical and hematological analyses. The safest and most efficient treatment of pyometra is surgical ovariohysterectomy.There is room for improvement of both diagnostic tools and possible prognostic indicators for pyometra.Mast cells are large leucocytes, with granule that contain inflammatory mediators.

In this study I have compared two systems of handling TMR, self-propelled/ self loading mixers and conventional towed mixers, what has been investigated is the time for filling, mixing and feeding TMR as well as maintenance and fuel consumption. The background of this study is the structural rationalization within the Swedish milk production that has put focus on efficiency and reducing of costs. Forage and labour are the two biggest costs in milk production today. The study has been performed by visiting three farms and with a stopwatch measured the times for filling, mixing and feeding TMR. At the time for the visits, the users have been interviewed regarding maintenance and fuel consumption. They have also had an opportunity to give comments of how they experience the mixers. The result of the study after processing is that the average stock in the study can save 74000 SEK a year by reducing time for filling, mixing and feeding TMR to cows with a self propelled/ self loading mixer . The conclusion I can make of this study is that it?s not the size of the stock that decides whether it?s interesting to invest in a self propelled/ self loading mixer, but the presumptions on the farms, for instance forage logistics and mechanical equipment..

The production of ferrochromium alloys at Vargön Alloys AB contributes to formation of unwanted ferrochromium dust, which contains toxic Cr(VI). The dust is since summer 2005 treated with an iron-sulphate solution to reduce Cr(VI) to the non-toxic Cr(III). A year later the treatment technique was improved and disposal occurs in cells on the landfill. The cells can be up to 300 m3 and the edges can be made out of fro example concrete. Tests are conducted on the treated dust when it is disposed.

Background: Chemotherapy and radiation resistance are major causes of failure in cancer treatment. The response to treatment in cancer cells depends on several mechanisms and pathways such as Janus kinases-signal transducers and activators of transcription JAK/STAT pathway. STAT1 was the first described transcription factor in the STAT family. STAT1 is activated by stimulation of signaling proteins such as type II interferon (IFN- ?) and the activated STAT1 translocates from cytoplasm to nucleus.

The work covered in this report includes a literature study of the diesel dual fuel technology(hereinafter referred to as DDF). The literature study covers earlier work that has been doneregarding the use of compressed natural gas (CNG) and diesel in a DDF system. Moreover a onecylinder research diesel engine was fitted with a CNG fuel system for experimental testing. Theinstallation of the engine and the test cell is described. Results from the tests are presentedcovering emissions, heat release and pressure traces from the DDF-concept.During the literature study it was found that most research was related to heavy duty dieselengines.

Mastitis, inflammation in the udder tissue, caused by S. aureus is a big problem in dairy cattle production. It causes suffering for the cow and curing or replacing the infected cow is costly for the farmer. It is known that beef cattle also suffer from mastitis caused by S. aureus.

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.