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532 Uppsatser om Temperature thresholds - Sida 29 av 36

Grazing behavior of Ankole and Boran cattle in an improved herding production system

To be able to provide the growing human population with food, the productivity of the animals as well as land use needs to be improved and intensified. Hence, understanding the behavior of animals is crucial both for animal welfare and productivity as well as the management of the cattle. There are many factors affecting the grazing behavior of cattle in tropical conditions, such as human-animal interactions, herd management, breed, season and temperature. The purpose of this study was to investigate the grazing behavior of two tropical cattle breeds, Ankole and Boran cattle. Kenyan Boran belongs to a zebu type of cattle and is preferred to many other breeds due to the higher productive and reproductive capacity and adaptability to tropical conditions.

Laborationsmätning av vindtäthetens betydelse för en väggs U-värde

To fulfill the climate target that EU and the Swedish government have decided to apply, it becomes increasingly important that the energy efficiency of existing buildings and making new buildings energy efficient as possible. Of Sweden?s total energy consumption in 2011 was 40% used by residential and service. Of the 40% of the energy consumption was 60% used for heating and domestic hot water. A report from year 2012 shows that one reason why the heating volume is so great could be due to underestimating on the energy consumption for the heating in the planning of the building.

Menstruationscykelns och p-pillers påverkan på den fysiska prestationsförmågan

Effects of Menstrual Cycle and Oral Contraceptives on Sport Performance During the menstrual cycle, there is a variation of the female steriod hormones estrogen and progestogen. These hormones has mainly reproduktive functions, but do also affect other physiological systems, which may have an influence on athletic performance. The use of oral contraceptives among female athletes matches the use among the general population. There is a concern among female athletes and there coaches weather oral contraceptives can affect the performance. The purpose of this litterature review is to determine the effect of the menstrual cycle and the use of oral contraceptives on athletic performance.

Förändring av grönområden i Västerås tätort det senaste seklet : Konsekvenser av att grönområden förändras

This thesis was done after a request from the county?s administrative board of Västmanland to provide the board with a better understanding of how green areas have changed within Västerås municipality over time.The purpose and goal of this study was thus to measure and analyze how much of the green areas within Västerås municipality that have disappeared during the past one hundred years as well as to provide a review of previous studies regarding the importance of green areas for humans as well as the biological diversity.In order to answer these questions I have in this study used a combination of a literature study, cartographic analysis as well as a time series analysis. The computer software used to do the measurements of the green areas was ArcGIS which is a geographical information system.In the cartographic and times series anlaysis measurements and analysis was made of the district map of 1911, the economic map of 1950 and the property map of 2011. The measurements show that the municipality has grown with 46,3 km2 over the last one hundred years. New neighborhoods? have emerged and the municipality has expanded.

CFD simulering av en fyrtakts Otto motorcykel motor

This thesis deals with the numerical 3D simulation of a four stroke, spark-ignited, internalcombustion engine, which is mounted on a high performance motorcycle. The work, carried outin collaboration with Politecnico di Milano and MV Agusta, focuses on the simulation of theintake, compression and expansion stroke, including combustion simulation, using an opensource CFD code.Simulation of internal combustion engines offers a great challenge in the field of CFD research.Moving boundaries of the solution domain, caused by the motion of the piston and valves, leadsto deformation of the computational grid, with decreasing quality of the solution as result. Basedon this, a previously developed mesh motion strategy was employed where a number of meshesare used to cover the whole simulation cycle. Within each mesh interval the internal cell pointsof the mesh are moved to account for the boundary motion of the piston and valves. This strategywas previously applied to simplified geometries as well as real engine geometries.

Nötköttsproduktion i Västerbotten

Beef production in Sweden has traditionally been about rearing of dairy calves to slaughter. With reduced number of dairy cows and accordingly less dairy calves for slaughter, there has been a need for new forms of beef production in Sweden. In Västerbotten there are good conditions for beef production with a high feeding level of roughage due to favourable climate. The aim of this thesis is to, through interviews with ten farmers with beef production in Västerbotten, study what and with how much they feed their animals and link the results to production level. The thesis begins with a literature review where the general feeding standards and feeding recommendations for beef cows and growing cattle are examined.

Metoder för lastprioritering i fjärrvärmecentraler

A problem in the field of district heating is the oil burners needed to provide power when a peak load occurs. One possible way of reducing the needed amount of oil is to reduce the power demand for space heating in the district-heating substations when the need for district heating water exceeds a certain limit. This can be done by use of a locally working controller function.In this Thesis the options concerning load priority are evaluated. To evaluate the potential for using controller functions concerning peak load priority an experiment was brought out in a chosen district-heating substation. The impact on the indoor thermal comfort during a heat reduction was also taken into account.

Optimization of Burner Kiln 7, Cementa Slite

In this report focus is put on the combustion process at a cement plant. Combustion is the heart of the cement making process and absolutely crucial to have under full control and well optimized. The fuel is put into the process through a burner pipe and this burner pipe is modified to reach a more efficient combustion. The primary target is to enable burning of heterogeneous alternative fuels and increase the production level. Other positive effects from this type of optimization is lowered specific fuel consumption and lowered CO2 emissions. A redundant burner is chosen for the project and overall the project steps are the following: 1. Installing a Jet air nozzle ring in a way so it can move both axially and radially due to temperature changes. 2.

Autumn water sources for understory vegetation and fungi in a boreal forest : an evaluation using stable isotopes

Understory vegetation and fungi are regarded as important ecological drivers of processes like productivity and nutrient cycling in boreal forests. Whilst those processes are linked to soil water content, relatively little is known about the sources of soil water for these forest components. During early autumn in boreal forests, temperature falls and large events of rain are frequent which may influence soil water availability. To better understand the autumn plant-soil-fungi water relationships in this ecosystem, I used stable isotopes techniques in this study to examine the water sources for ericaceous shrubs and fungi in a Scots pine forest following a large, early autumn rain event. I hypothesize that ericaceous shrubs of two functional groups (evergreen vs.

Småskalig elproduktion i Arvika

Arvika Fjärrvärme AB, a district heating company from Arvika, today cover 74 % of their total energy production with biofuel wich runs a 16 MW bioler giving process water at saturated liquid state.In recent years Vaporel AB has introduced a new tecnique that gives an external generation of steam after boilers. The concept is built on an adiabatic pressure drop of the saturated liquid in a so called Flashbox which makes a small part of the liquid to evaporate. The generated steam is lead into a turbine where electricity is in a conventional manner.The purpose with this rapport was to do a basic study for the specific system at Arvika where it?s possible to see the potential production of electricity that follows an installation of a flasbox.The final goal was to introduce an economic analysis of a flashox installation at given conditions.To reach our goals we have created a model in Excel where we used the given conditions at Arvika Fjärrvärme to do our calculations. The model has been tested at three different states, of process water returning to potboiler, to be able to decide the optimal operation for the system at present.The studies have resulted in a pressure of the processwater at 14,5 bar (at) and a pressuredrop to 9,5 bar (at) in the flashbox.

Nedbrytning av propylenglykol i uppsamlingssystem för avisningsvätskor : En studie utförd vid Stockholm Arlanda flygplats

Deicing fluids based on Propylene glycol are used at Stockholm Arlanda airport to remove or prevent ice on aircrafts. The high oxygen demand of propylene glycol can cause oxygen depletion in rivers downstream from the airport if not collected. Mass balance calculations made by Swedavia indicate that the actual amount of gathered propylene glycol is underestimated. Suspicions that propylene glycol is degraded in the stormwatersystem designed to collect deicingfluids, called the B-glycolsystem, have to be investigated in order to establish with certainty that no propylene glycol in other ways leaves the B-glycol system.The purpose of this study was to determine if degradation of propylene glycol is present in the B-glycol system and also to estimate the extent of the degradation. Propylene glycols high biological oxygen demand can cause oxygen depletion in waters downstream from Stockholm Arlanda airport if not collected.

Habitat preference and dispersal of a sandassociated beetle, Apalus bimaculatus

Species that have a high degree of specialization and poor dispersal ability can be more prone to extinction than more generalist species and good dispersers. How these species traits affect the viability of populations is dependent on landscape factors,such as isolation and connectivity. Additionally, interactions between species (e.g. symbiosis), and how these interactions vary spatially and temporally can have a large impact on populations. When the range and habitat areas of a species continuously decrease, management strategies are often needed if the species shall be able to survive.

PlusTak

Today´s roofing of dwelling houses is a very time consuming procedure, which includes a lot of different steps on the construction site. Not only does it cost a lot of money, but often do problems with rot and mold occur in the attics of houses today. The use of prefabricated modules has seen a great breakthrough in the field of construction of dwelling houses; at least when it comes to foundations and walls, where this type of approach makes the construction process way more efficient. What no one previous has succeeded to develop is a corresponding system for roofs that meets the demands of a dwelling house. Accordingly the goal of PlusTak has been to come up with a proper module system for roofing of dwelling houses, where the roofing is completed to meet the demands of the Scandinavian market. During the project a lot of effort has been put into customer contacts and the usability of the product, as well in the manufacturing process as on the construction site. This development has gone hand in hand with several practical tests and tryouts.

Timeliness cost for agricultural sprayers : weed control in cereal crops

Evaluation of machinery costs is necessary for selecting appropriate farm machinery. Timeliness cost due to untimely operations is an important component of machinery costs. Timeliness costs can be high for crop sprayers, since pesticide application must be carried out within a short time interval. This Master thesis investigated the timeliness cost and the probability of a suitable workday for spraying. Timeliness factors were estimated for four different crops (oats, spring wheat, winter wheat and barley) using historical weed trial data.

Hur påverkas dvärghamstrar av att vistas i hamsterbollar?

Lately the popularity to keep different species of dwarf hamsters has increased in Sweden. The requirements of the Swedish legislation to keep hamsters as pets are low which could be a reason for the increasing popularity. Hamsters are in nature generally nocturnal and can travel far distances to find food sources during their active part of the day. Their eyesight is poor, but is compensated by their well-developed hearing and olfaction. ?Run about balls? are made of plastic and the hamster is placed inside it where after the ball is placed on the floor and the hamster can then run protected outside the cage.

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