There is considerable variation between stallions in semen quality and fertility due to the fact that selection of stallions for breeding is not based on fertility or semen quality but on performance. The increasing use of cooled semen for artificial insemination has resulted in decreasing pregnancy rates. Therefore the equine breeding industry needs new methods for evaluation and development of sperm quality and fertility. This study is a part of such a project and is performed by SLU in cooperation with Flyinge AB. Ten stallions at the Flyinge National Stud were used in the study and three ejaculates were collected from each stallion.

The global climate-change means increasing mean-Temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

The scope of this investigation is to decide how and to what extent the energy consumption of apassive house is affected by the users? knowledge and habits. To achieve this a literary study hasbeen made and as a complement the planning of a passive house was completed.The result of a primary study of the rules and regulations that effect passive houses in Swedenshows that the user?s influence on passive houses is a completely unregulated area. Even thoughthere is no regulation, a need for some general knowledge of the passive house concept has beenexpressed.To further investigate how the users? knowledge and habits affect the energy consumption and ifthere is a difference between different households? energy consumption , three main factors havebeen identified.

Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity. Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.

This thesis has been carried out in cooperation with a company which develops mobile sensor platforms. The sensors measure different types of data such as Temperature, pressure etc.. They will communicate through the internet with a server that stores data in a database. This system will be controlled and monitored through a web page. The project's aim has been to develop this system and to implement a server, a database, a website and a client application that simulates sensor signals.

The Annexin-V/propidium iodide (AV/PI) assay detects early membrane changes in spermatozoa and viability using flow cytometry. It is an objective method that evaluates a much larger number of single spermatozoa compared with the usual estimation of motility, the most commonly used method for routine sperm evaluation. In the present study four ejaculates from four stallions were used in a split-sample design to investigate whether and how the number of intact spermatozoa is affected over time and after incubation at different Temperatures, either those recorded during shipment of stallion semen for AI (9 or 5°C) or room Temperature (20°C). The Annexin-V results did not reflect the motility results that were monitored in parallel. While motility decreased over time, the number of spermatozoa with intact membranes (viable) remained unchanged for at least 21 hours following a short period of initial instability.

For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the Temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.

The world is in a stage of climate crisis where the average Temperature is rising, with consequences such as, melting ice sheets, increasing sea levels, and floods. The climate panel of the UN, IPCC, has stated that this is a reaction of anthropogenic emissions of greenhouse gases. The most important gas is carbon dioxide, which contributes with 80 per cent to the on going climate crisis.The increasing emissions of carbon dioxide are connected to human consumption patterns. This puts pressure on the earth, as humans demand more and more resources. Today the earth needs one and a half year to regenerate the resources humans? demand of it, by the year 2030 we will need two planets in order to cope with this increasing demand of resources.At a global level it is established that richer countries have a stronger consumption pattern than poorer, and thus generate higher levels of carbon dioxide emissions.

Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the Temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.

The interest in tiny wireless applications raises the demand for an integrated reference oscillator with the same performance as the macroscopic quartz crystal reference oscillators. The main challenge of the thesis is to prove that it is possible to build a MEMS based oscillator that approaches the accuracy level of existing quartz crystal oscillators. The MEMS resonator samples which Philips provides are measured and an equivalent electrical model is designed for them. This model is used in the simulations of the Pierce oscillator and the transresistance amplifier oscillator that are evaluated in this thesis. Finally the Pierce oscillator is implemented in the A BCD2 process and manufactured at Philips Semiconductors in Nijmegen, The Netherlands.

The aim of the study was to install a biogas system consisting of three tubular polyethylene biogas digesters at a rural household in Malawi and to evaluate the constructed biogas system with regards to relevant system parameters. The purpose was to evaluate if the technology is a possible solution to reduce deforestation and support Malawi in climate change mitigation and adaptation. The study was carried out in the southern part of Malawi in cooperation with the University of Malawi. Locally available materials were used to construct and install the system. Three different feed materials, cow, goat and a mix of cow and goat manure, were used in order to determine which one was best suited to utilise as a digester substrate. After the installation, measurements of Temperature, pH, biogas production, biogas composition and system functionality were made. The results of the study show that a biogas system with tubular polyethylene biogas digesters can be successfully installed at a rural household and that the most suitable feed material is a mix of cow and goat manure.

Compressed air is an energy source that is widely used in today's trucks and buses.Compressor located next to the engine supplies the pneumatic system with the compressed air and is lubricated with the engine oil. Some of the oil follows the air flow in both liquid and solid phase. The solid phase, namely the carbon particles are created due to the high Temperature in the compression chamber.Oil- and particles carryover softens and destroys the rubber material in the air valves and disturbs the mechanical function of various components in the pneumatic system. In order to reduce oil- and particles carryover is an Air Processing System (APS) set downstream the compressor.No method for establishment of oil- and particles carryover from the compressor exists at the moment. Therefore the filtration efficiency of APS is currently unknown.

A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.

Farmers are required to make sure that cattles basic needs are met, but still every year cases of neglect occur where the farmer has not complied within the animal welfare law and regulations. The aim of this study was to investigate how cattle are affected physically and behaviourally by neglect in the form of underfeeding, starvation and lack of sanitation, which animals are most vulnerable to the impact and what prospects they have to recover. The study was conducted as a literature study and the results show that these types of neglect have a large impact on the cattle welfare. Underfeeding and starvation causes physical changes leading to reduced milk production, reduced muscle mass, impaired immune function, poor reproductive performance and changes in rumen microflora leading to decreased number of microbes and pH change. Physical changes due to the lack of sanitation consist of increased vulnerability to hoof diseases and mastitis, burns, and increased sensitivity to Temperature.

Mechanical ventilation is the most common type ofventilation in newly constructed office buildings. Therehas been an interest to utilize natural ventilationinstead of mechanical ventilation among architects andHVAC consultants in recent years. This is due to thesize of mechanical ventilation systems, which arespace consuming. The mechanical ventilation system isalso complex and requires maintenance. Furthermore,the fan uses a considerable amount of energy.