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2536 Uppsatser om Current measuring - Sida 4 av 170

Utvärdering av förbättrad metod för objektiv kvalitetsbedömning av spermiemotilitet hos hingst :

In this trial we used QualispermTM as an objective method of measuring stallion semen. Samples of semen were analyzed before and after centrifugation. Motility and concentration were statistically analyzed. During the trial all the objective mesaurments were compared to a subjective method. The advantages of QualispermTM compared to older CASA- systems is it´s ability of measuring a greater amount of spermatozoa while it also grades them into different subpopulations. These subpopulations have different qualities that decides their capacity of fertilization. The results showed that this objective method might be used practically. Although, there are still some disadvantages, such as high costs and the necessarity of accurat training of the handler. If it´s possible to prove further relevant results that also are statistically correct, this could prove the usefulness of QualispermTM as an objective measurment method in the daily work at gestuts and stallion stations, thus giving the staff a reliable instrument in assisting the work for an improved horse breeding in Sweden, improving both in quality and economically..

Vakuumbrytare i småskaliga vattenkraftstationer

This master thesis has been performed at Vattenfall Power Consultant in Gothenburg and Trollhättan for Vattenfall Vattenkraft. In this report vacuum circuit breaker in small-scale hydropower stations with the rated power 4 MVA and below has been studied. Models of the stations are modeled and analyzed in PSCAD/EMTDC to study the high voltage transients that are created after current chopping with vacuum circuit breaker. Vacuum circuit breaker may chop the current before it reaches zero value, which means that high voltage transients can be created. The equipment of the stations can be destroyed by high voltage transients.The purpose of this thesis is to examine the use of vacuum circuit breaker in small-scale hydropower stations and the risk for high voltage transients from current chopping.According to the results there is a risk of high voltage transients after current chopping with small synchronous generators in stations with the operating voltages 0.4 kV and 3.6 kV.

Förbättrad resistansmätning för grova aluminiumledare

The goal with this master thesis has been to evaluate and to examine the stationary resistance bridge. The resistance bridge uses a 4-point measuring to determinate the resistance, which is used in the manufacturing of the conductor. It is then used when the resistance is to be decided for coarser aluminium conductors. A conductor has to fulfil certain demands to be able to move forward in the process. One of these demands is the resistance in ohm/km, which has demands that the measure values of the resistance bridge are as true and precise as possible.

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.

Balis trädgårdar

The urbanization of the world is increasing. How it affects bird populations have been well studied during the last decade, and comparisons between urban and non-urban habitats have been carried out. A common method for measuring habitat quality is to calculate the population density. This method is easy to use, but have been criticized during the last couple of years. In this study, data of population densities was compared with data on reproduction success.

Väderstation

We got in contact with Marco AB, who we?ve had contact with before concerning earlier projects, to find out if they were interested in arranging a larger project for our last class (Examensarbete 15hp). They were very positive to this proposition, and soon they offered us a project regarding reconstruction of their current mechanical device that absorbs all the force from the lift itself when it is at a predefined level (sv. sjunkspärr). The current solution does fulfill the requirements that are given, however it is not a solution that gives a high level of satisfactory.

Att studera validerade mätinstrument : för att mäta barns oro inför dagoperation

Background: Anxiety with children before surgery is well known. From the 1950s there are various assessment instruments. Despite that most day surgery units offer preparation for children and parents, there are many children who exhibit a strong anxiety the day of surgery, which can lead to postoperative behavioral changes. Today the nurse estimates the anxiety of a child on personal experience and knowledge, forming the basis for estimation whether the child is in need of sedation or not. The purpose: of this study was to evaluate instruments that the nurse can use in measuring the degree of anxiety of children before fast clinical settings, such as day surgery.

Förbättrad resistansmätning för grova aluminiumledare

The goal with this master thesis has been to evaluate and to examine the stationary resistance bridge. The resistance bridge uses a 4-point measuring to determinate the resistance, which is used in the manufacturing of the conductor. It is then used when the resistance is to be decided for coarser aluminium conductors. A conductor has to fulfil certain demands to be able to move forward in the process. One of these demands is the resistance in ohm/km, which has demands that the measure values of the resistance bridge are as true and precise as possible. The stationary resistance bridge had been examined through various kinds of measurements to be able to see how stable the system is and how to obtain a measure value as optimized as possible.

Fast driftställe enligt OECD:s modellavtal i ljuset av elektronisk handel

The purpose of this thesis is to examine whether the concept of permanent establishment, as defined in Article 5 of the OECD Model Tax Convention on Income and Capital, is applicable to electronic commerce and if so whether the current definition is able to appropriately deal with the challenges of electronic commerce.In 2003, the OECD added a new section to the Commentary on the Model Tax Convention on Article 5. The new section is a clarification on the application of the permanent establishment definition in electronic commerce.The current definition of permanent establishment in the Model Tax Convention relies on the physical presence of a foreign corporation as the threshold for source taxation. While the current definition, prima facie, might be applicable on electronic commerce, the highly mobile nature of electronic commerce might affect the current revenue distribution equilibrium between states..

Kan fysisk aktivitet förebygga Alzheimers sjukdom? En litteraturbaserad studie.

Introduction: We are facing an aging population, which means that the incidence of age related diseases, such as Alzheimer's disease, are expected to increase. In the current situation there is no cure for the disease, whereupon it is important to develop preventive strategies. Objective: To examine the association between Alzheimer's disease and physical activity. Method: A systematic literature search was done to identify the current state of knowledge from the year 2006 onwards. The reason for this limitation was that the SBU commissioned a systematic literature review in 2006, where the relationship between physical activity and Alzheimer's disease could not be determined.

Analys av lageregenskaper utifrån mätningar i testrigg

Vertical hydropower units has a rotating mass of up to 1000 tons. For the generator and turbine to work well the rotating system is required to be centered in relation to the surrounding structure. This is achieved by means of radial bearings. The dynamic characteristics of these bearings have a strong impact on the overall rotational dynamics of the total system and thus influence the vibrations in the unit. At Vattenfall Research & Development in Älvkarleby ongoing research is taking place on how the bearing parameters should be represented in the rotor dynamic calculations.

Social hållbarhet och förtätning : en kritisk studie i förtätningens sociala paradoxer

Densification is one of the urban visions for sustainable development - a vision that has become a part of the solution to the unsustainable sake dilemma. With the dense city land will be saved, energy consumption reduced and social cohesion improved. The dense city is considered to be ecologically, economically and socially sustainable. Applying an urban design concept has thus proven to be problematic. Density has been found to be a complex concept which is far more complicated than measuring how much built surface that needs to be covered. It is also not disputed what different degrees of densification mean and whether densification in itself is sustainable.

Utveckling av en metod och en utrustning för mätning av bränslesprayers rörelsemängd

A new type of device for measuring thev m& ?rate of fuel sprays from a diesel fuel injector has been developed and the various steps in the development are described. The device works by deflecting all of the sprays from the injector at the same time by using a bell shaped deflector. A load cell consisting of a machined steel part with strain gauges mounted on it measures the resulting force. The shape of the curvature in the deflector bell shape has been evaluated by photographing the flow in a 2D?version of the curve shape.

MÄTNING AV LJUDIMMISSION FRÅN VINDKRAFT. VIDAREUTVECKLING AV METOD FÖR MÄTNING

The Swedish government have a goal that wind turbines shall produce 30 TWh by the year 2020, compared to about 3,5 TWh produced in Sweden during 2010. To minimize the disturbance that wind turbines create the Swedish Environmental Protection Agency has stated a guideline value that noise from wind turbines at nearby residents shouldn?t exceed 40 dBA, at 8 m/s wind speed. With advanced calculation models, like Nord 2000, the emitted sound from future wind turbines can be calculated at an early stage to optimize the power production without exceeding the 40 dBA. When the turbines have been built there is a need to verify that they really are within the guideline.

Utveckling av drivrutin till Intermec Easycoder 501 XP

We got in contact with Marco AB, who we?ve had contact with before concerning earlier projects, to find out if they were interested in arranging a larger project for our last class (Examensarbete 15hp). They were very positive to this proposition, and soon they offered us a project regarding reconstruction of their current mechanical device that absorbs all the force from the lift itself when it is at a predefined level (sv. sjunkspärr). The current solution does fulfill the requirements that are given, however it is not a solution that gives a high level of satisfactory.

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