Sök:

Sökresultat:

1087 Uppsatser om Laboratory tests - Sida 24 av 73

Undersökning av energiförbrukning och konceptutveckling av mer energisnåla frukostmaskiner

This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.

Cross-sectional study of bovine anaplamosis in South-western Uganda : the impact of wildlife-livestock interface

The tick-borne disease bovine anaplasmosis is primarily caused by Anaplasma marginale. A variety of wild animals act as reservoirs for A. marginale, but the understanding of their role in the epidemiology of A. marginale is yet poor. This cross-sectional study was conducted to establish if proximity of wildlife affect the prevalence of bovine anaplasmosis in cattle.

BIODIVERSITETS P?VERKAN P? M?NGDEN ORGANISKT MATERIAL I ALSUMPSKOG: En fallstudie i fyra alsumpskogar p? svenska v?stkusten

Globally, coastal ecosystems like mangrove forests, sea grass meadows and salt marshes are well known for their ability to capture and store atmospheric carbon effectively. In Sweden, there is still limited knowledge about local coastal ecosystems with similar functions, with alder swamp forests being an interesting example. Therefore, this study aimed to increase knowledge of the factors that can contribute to the potential carbon sequestering ability of alder swamps. Vegetation data and sediment samples were collected from a total of 37 sampling plots across four alder swamps in Bohusl?n on the Swedish west coast.

Halvledare för höga strömmar i fordon

Mechanical relays are more and more being replaced with semiconductortechnology. In this thesis it is investigated if and how the larger loads couldbe controlled by transistors. The main part of this work aims to create andverify a solution that can control the starter motor, as well as protect it incase of any failure. The different malfunctions that the solution protectsagainst is high current, too high peak current, low current, maximum cranktime and minimum cool off time. The timers also protect indirectly againstoverheating of the starter engine.The transistors used are BTS555, from Infineon.

Statushantering i Virtual Map med ledningssamordning i BIM

For many years, the construction industry in Sweden has not developed much of an integral approach for design across disciplines. The sector?s impact on society, economics and environment is huge. To make the interactions within the construction industry more efficient, a relatively new concept called BIM (Building Information Modeling) has been introduced. The idea with BIM is that the different actors of the construction industry will work through intelligent CAD software, with common file formats and more cooperation between different actors during the various steps of the building and construction process.The technical consultancy company WSP Sweden is working actively to implement BIM within the frame of its activities.

Kommunikationshjälpmedel Sound and Display Communicator

During the last year in the Innovation Engineering Program, at Halmstad University, a degree project was performed that was carried out during Fall semester in 2006 and Spring semester 2007. The project was performed by two students in corporation with LIC Audio AB, a company in Stockholm. The degree project was meant to result in a communication aid for people with a cognitive handicap. The project focused on people suffering from dementia because of the expressed need within this group. This aid should first and foremost help in a conversation between a person with dementia and another person, like a relative or nursing home staff.

Utveckling av arbetsmetod för DFA

Scania is among the leading companies in the heavy vehicle industry. Scania also assemble engines for their trucks and buses, as well as to external marine and industrial applications. Wrongly assembled parts leads to quality problems, which makes it important to secure that the assembly is correct. To do this Design For Assembly (DFA) is used to describe how parts should become easier to assemble. Scania?s production unit for engine assembly has had a working method for DFA in the shape of a checklist, which is not used.

Effektivt nyttjande av högeffektslysdioder i mobil belysning

The purpose of this master thesis has been to find different solutions to the design of a headlamp with a cluster of three or possibly four high power LEDs (Light Emitting Diodes). During the work, two different problems have been considered; how to design a lens in order to shape the light beam in a desirable way, and how to design a cooling system which will lower the temperature of the LEDs as efficiently as possible, still taking into account the geometry set by the optical solution as well as other given geometries. The results presented in this thesis are partly the outcome of a literature study, but derive mainly from a number of tests and measurements made on two test rigs and one concept prototype..

Browser Wars : Kampen om webbläsarmarknaden

The first browser war took place during the second half the 1990s, and Internet Explorer cameout as the winner over Netscape Navigator. Today a new browser war is being fought withmany competitors and the future is uncertain. The purpose of the thesis is to find out how theweb browser market has developed since the start of the previous conflict, and we ask ourselveshow it will continue to develop in the future. This is accomplished with, among otherthings, interviews, tests and already existing statistics. The thesis' conclusions shows that theweb browser market has developed in a positive way from several perspectives, both for theusers as well as for the web developers.

Definition av stötdämpares fyllnadsgrad

Shock absorber units play a key role in establishing the driving dynamics and performance of automobiles. Öhlins Racing has manufactured high-tech automotive shock absorbers for over 30 years. Öhlins Racing?s advanced technology has contributed to over 200 world championships in automobile racing. Öhlin?s manufacturing process has long utilized automated fluid filling equipment during the final shock absorber unit assembly stage. The filling process consists of vacuum pumping the shock absorber unit and subsequent transfer of fluid. Vacuum pumping is necessary to remove residual air from the shock absorber unit prior to initiating the liquid filling stage. The presence of undesirable gases drastically compromises the performance of a shock absorber. The filling degree, defined as the final ratio of air to oil, is determined by the specific filling protocol as well as the specific equipment utilized.The current investigation aims to develop a viable technique to accurately determine residual air content in shock absorber units. If the filling degree can be appropriately quantified for a specific manufacturing process, then the air/oil ratio may be quantitatively related to shock absorber performance. The utilized measurement method must be completely integrated into the manufacturing process to guarantee shock absorber performance specifications according to the manufacturer?s standards. By utilizing the measurement method developed in this work, the manufacturing process, manufacturing equipment and product specifications can all be tailored to provide improved filling conditions.The developed measurement method provides accurate quantification of the filling degree under a wide range of processing conditions. The method establishes the relative quantity of air in the shock absorber unit by performing in-situ compressibility tests. The fill ratio can be controlled and varied by manipulating the vacuum pressure exerted during the filling process. Performance tests, however, indicate no correlation between filling degree and unit performance..

Design och konstruktion av laborationsutrustning till en kraftelektronikkurs

The purpose of this degree project was to build laboratory equipment for a new course in power electronics that starts this autumn 2010 at Uppsala University. The equipment is intended for student labs and it covers the most important areas of the course including rectifying, buck-/boost-converters and PWM-modulation. It is built as one sealed unit where all the electronics are built-in but visible and it has a connection board where students safely can connect the different circuits. The project has advanced from theoretical studies of circuit design, choosing of components and simulations to drawing the printed circuit board (PCB), soldering, case building, final testing and troubleshooting - basically most steps from an early idea to a final product. Measurements on the final product gave about the same results as the earlier simulations of the circuits and the result is overall satisfying..

MEASUREMENT OF C-REACTIVE PROTEIN IN CANINE SERUM ON KONELABAUTOANALYZER 20

An inflammatory reaction is induced after release of proinflammatory mediators such asinterleukin 1 and 6 and tumour necrosis factor ?. These mediators stimulate the liver tosuppress the syntheses of albumin and endure the syntheses of acute phase protein forinstance C-reactive protein. The aim of this paper was to perform a method validation on animmune turbidimetric assay to quantify C-reactive protein in canine serum at the laboratory atSkara Animals Hospital, Skara, Sweden. The validation involved evaluation of the assaylinearity, precision, stability and recovery.The method was proved to be linear for both TruLab control and Medinor control.

En statistisk undersökning av transkriptionsnoggrannheten i kodande DNA-sekvenser i E.coli-bakterien

Bacteria are exposed to evolutionary pressure to an extent unlike other organisms. This leads to a high degree of adaptation to its surrounding. This thesis investigates the degree of adaptation towards higher accuracy in the transcription of DNA to RNA in coding sequences in the DNA of the E. coli bacteria. Two coding sequences with different nucleotide contents were investigated.

Aktieåterköp och undervärdering: : En empirisk studie av signalling-teorin

This paper tests the information signalling hypothesis on a sample of firms making open market stock repurchases. Using an earnings-based valuation model, we find that a majority of repurchasing firms are undervalued relative to their economic value. This result is consistent with previous academic studies, which claim that undervaluation is the prevalent factor explaining the observed abnormal return following the announcement of a repurchase program. We do not, however, find any evidence that the repurchase is consciously made by management to provide the market with new information. .

Utvärdering av en snabbtest för diagnostisering av hypokalcemi hos nötkreatur :

Clinical signs of hypocalcaemia in dairy cows are easily recognized, and a rapid response to treatment generally confirms the diagnosis in the field. However, clinical signs of other disorders in cows, such as toxemia, calving paralysis, or muscoskeletal injury, may mimic those associated with hypocalcaemia. Therefore, making a diagnosis of hypocalcaemia on the basis of clinical signs alone may be difficult. In ambulatory veterinary practices, cow-side tests are useful to make the diagnosis and prognosis easier. Kruuse?s Kalcium Test is a cow-side test based on the principle that calcium ions are necessary for coagulation of blood, and that chelation with EDTA prevent coagulation.

<- Föregående sida 24 Nästa sida ->