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629 Uppsatser om Voltage measuring - Sida 15 av 42

Partiell Urladdning- Mätmetoder och detektering med fokus på HVDC- kablar

Detta arbete behandlar mätmetoder för detektering av partiella urladdningar (kallad PD från engelska benämningen Partial Disharge) i HVAC- och HVDC- högspänningskablar. HVAC står för ?High Voltage Alternative Current? och HVDC står för ?High Voltage Direct Current?. När en viss hög spänningsnivå överskrids i kabeln uppstår olika typer av partiella urladdningar och dessa skadar kabelns isoleringsmaterial. PD- intensiteten ökar med tiden och om de tillåts fortlöpa under en längre tid kan de med tiden helt bryta ned isoleringsmaterialet vilket leder till ett fel.

Utveckling av metoder att mäta centrering av skruvhål i skär

There have been, in some rare cases, difficulties with clamping of inserts with U-holesin their tool holder. According to the complaints, the inserts could not be properlyclamped or could fracture when clamped. A study has shown that variations inclamping behaviour are mainly depending by the position of the screw hole in the toolholder and the centering of the screw hole in the insert.The focus of this project has been the centering of screw hole in insert. It has beenshown that the screw holes are not always enough centered in the insert. Theproblem may occur after a certain step in the production, i.e.

AESED och FQ SJÄLVSKATTNING FÖR ANHÖRIGA TILL UNGDOMAR MED ÄTSTÖRNING

Syftet med föreliggande studie var att bidra till utvecklandet av självskattningsskalor för föräldrar till barn med ätstörningar. Skalor som ska kunna användas diagnostiskt men också vid utvärdering av behandling. Två instrument utprovades; AESED som mäter i vilken grad föräldrar anpassar sig till ätstörningssymtomen och hur påverkan på familjesystemet ser ut med utgångspunkt i Schmidt och Treasures modell om vidmakthållande av symtom, samt FQ som mäter expressed emotion. Detta kompletterades med HAD som mäter ångest och depression. Studien genomfördes vid SCÄ ? Stockholms Centrum för Ätstörningar och data jämfördes med motsvarande material från Västerbotten.

SERVQUAL : ett lämpligt mätinstrument av upplevd tjänstekvalitet inom reseindustrin?

The travel agencies exist on a market that is distinguished by increasing competition. A majority of the travel agencies offer different services that all satisfie the same customer need. However,one major difference in the market aspect is the service quality, this making it an important mean of competition. There are several acknowledged methods of measurement when it comes to service quality and it is important to use an instrument that takes into consideration the fact that charter tours is a complex merger of several services. The purpose of this essay is to establish if the SERVQUAL method is a suitable instrument for measuring service quality in the travelindustry.

Undersökning av energibesparande metoder för multiplikator

In this thesis a number of energy saving methods for a multiplier on algorithmic level are investigated. For the investigation a multiplier is constructed in VHDL, after which the circuit's performance is investigated. A number of techniques for reduced power consumption are introduced in the circuit and are then evaluated. The conclusions are that all investigated methods, pipelining, interleaving and voltage scaling, should be maximally made use of in order to minimize the power consumption..

Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik

Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.

Implementering av Constant Fraction Detection vid avståndsmätning

This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.

Utveckling av en ytmonterad fördelningsmätare som underlag för individuell debitering av vattenförbrukning i fastigheter

The master thesis, conducted at Metrima AB, concerns the development of a non-intrusivedistribution meter as a basis for individual tap water billing in apartments.The project is conducted in response to the market interest in individual tap water billing inapartments as an answer to environmental concerns regarding water consumption. Due to thehigh installation cost of traditional water meters, a new method of determining waterconsumption, without having to cut water pipes, is proposed.The proposed method distributes the total water consumption for an apartment complex toindividual apartments according to distribution meters, measuring water run-time, in eachapartment. The water run-time is estimated by measuring the water pipe?s outward vibrationsand temperature changes.A test environment was established and a prototype built, using a tilt- and vibration sensor forvibration sensing and a precision temperature sensor to measure temperature changes. As bothsensors work well in the test environment, further testing was done in 3 apartments for aduration of 5 days.

Utveckling av styrsystem för EMC-kammare

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Övertänjd urinblåsa- redan före operation? En observationsstudie

Introduction: Urinary retention is a common postoperative complication associated with bladder distension. Permanent damage to the bladder affects the patient?s quality of life and may lead to a lifelong inability to empty the bladder and needs of self-catheterization with the risk of urinary tract infection. Bladder distension was classified as the fourth largest health care related injury in Sweden in 2013. Bladder distension may occur before the operation starts and is more common among orthopedic patients.

Analys och förbättring av en mätenhet för laddning av elfordon

Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

En jämförande studie mellan kreatininkoncentration i serum och GFR mätt med scintigrafi hos hund med misstänkt kronisk njursjukdom

Both serum creatinine and measuring GFR can be used to evaluate renal function in dogs suspected to have chronic kidney disease (CKD). Although high creatinine levels usually indicate renal disease, normal creatinine levels can be present in dogs with decreased renal filtration. Measuring GFR is generally believed to be the most accurate way of detecting decreased renal filtration and scintigraphy GFR using 99mTc-DTPA has been found to correlate well with the ?gold standard? inulin clearance method.When measuring GFR by scintigraphy, 99mTc-DTPA is injected intravenously and radioactive decay of technetium gives rise to gamma radiation, which is registered by a gamma camera. Pictures and curves of radioactivity in the kidneys are generated by means of a computer program.

Design och konstruktion av mätuppställning för induktiv mätning av magnetisk spinndynamik

Development in spin dynamic occurs in the whole world because of therising demands on fast electronic storage for example hard drivesand RAM (Random Access Memory). Measuring the spin resonance of amaterial gives you the insight of the theoretical speed for amagnetic memory. This means the maximum storage speed is below thefirst resonance. All magnetic materials have different propertiesthat will inflict the resonance frequency which brings that theconstructors of memories need to know which magnetic material theywill use to obtain best results. In the market for normal users themaximum storage speed in a RAM memory is 1.6 GHz.

Evaluation of Different Extraction- and Analysis Methods for Calprotectin in Feces

Background Calprotectin is a protein expressed in the cytoplasm inside the neutrophile granulocytes. During inflammatory bowel disease (IBD), the neutrophile granulocytes are involved in a complex interaction at the inflammatory area where they die and release their content into the intestinal lumen. Therefore, calprotectin in stool is a suitable marker for diagnosis and measurement of the disease-activity in patients with IBD. The most commonly used method to detect calprotectin in stool is ELISA, but the process of manual preparation of stool samples is time-consuming.Aim The objective of the study was to evaluate an extraction method that could replace manual preparation of fecal samples and to compare different methods for measuring Calprotectin in stool using two ELISA-methods from two manufacturers and one rapidtest.Methods For extraction of calprotectin from stool samples we used sample collector tubes from Epitope Diagnostics and fecal preparation kits from Roche. Two different ELISA-kits for measuring calprotectin concentration in stool were compared.

Specificering av produktionstransformatorer : Rekommenderade avsteg från IEC 60076 för att vid upphandling beskriva en robust enhet

As break downs of production transformers are costly and often result in long outages it is essential for reliability of operation that the transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.

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