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370 Uppsatser om Voltage drop - Sida 18 av 25

Undersökning av exponeringsindex för bildplattesystem inför optimeringsarbete

The county hospital of Dalarna has for the last couple of years carried through a process of digitalization. The result is that within the county it exists image plate systems from two different manufacturers. In an attempt to create a tool for dose optimization and dose surveillance the county of Dalarna would like to investigate if the exposure index from Agfa and Fuji is suitable as a dose indicator. An investigation of the exposure index, S, from Fuji has already been done. This thesis has been continuing the investigation by evaluating the stability of the exposure index, lgM, from Agfa.

Spelutveckling och lansering av applikation till Android

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.

Utredning av variablerna som påverkar storleken på brytspänningen i lindningskopplare

Brytspänningen är den spänning som uppkommer när överkopplingsmotståndet i lindningskopplaren lämnar sitt föregående läge vid omkoppling. Storleken på brytspänningen i lindningskopplaren beror på hur stor läckinduktansen är. Är den inte känd så kan brytspänningen istället beräknas med hjälp av FEM-programmet ACE (internt ABB-program) i samband med Mathcad. I ACE beräknas först reaktanserna i p.u-enheter mellan lindningarna och hur stora de är beror på lindningslayouten. Det är tidskrävande att använda ACE och Mathcad och uppgiften är att utreda de parametrar som påverkar storleken på brytspänningen samt att ta fram en förenklad beräkning av densamma.Genom simulering i ACE av en mängd olika lindningslayouter visar det sig snart att det är alltför många parametrar som påverkar reaktanserna.

Konstruktion av datainsamlingskort för mätsystemet COMET

During test flights SAAB uses the data acquisition system COMET 16. The part of the system that receives the signals from the sensors and converts them is called KSM 15. The purpose of this thesis is to develop a data acquisition module on stacked PC/104 modules with a lower production cost. Our work has been divided into one part about analog signal conditioning and a second part with digital filtering and memory management of the sampled data. The analog part, designed of regular components like instrument amplifiers, voltage references, operational amplifiers and multiplexers, adjusts the sensors signal levels for the ADC?s that converts the signals.

Dokumentation av en experimentell biogasanläggning

This thesis is   focused on identifying and documenting all   electrical equipment, such as devices, power lines / cables, and connectors in the facility and also on presenting a brief   technical description and information of the systems around the reactors.   Furthermore there will be a brief description of LabVIEW - which is a   graphical programming language- and which devices / elements   are programmed. For further notification, I am not   responsible for the programming of the devices in LabVIEW   which I have only used as a tool in my work. The plant   for production of biogas consists of four reactors   of which the third reactor (Lakbädden)   is connected to another reactor (UASB)   where they cooperate with each other.   The reactors are used for producing   biogas in the form of methane gas.The reactors I and II are   connected to, various electrical devices as, flow meters, temperature   sensors, frequency converter and   more.

Experimentell konstruktion av pickupsystem anpassat för trummor med hjälp av MATLAB

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.

Bloggar som kommunikation : inom förskolan, skolan och fritidshem

Parents today can be very stressed at the drop off and pick up of their children, this leads to that they sometimes miss important information that is pinned to the walls for example. Papers has the ability to disappear, a blog collects all in one place. Today, almost everything is digitized.This study has examined what a blog is and how schools and preschools can use it. The blog is used as a communication site for the preschools and school. This exam graduate work is made of three blog analysis, the analysis is made to see if the blogs can help the preschool and school to communicate wiht the parents.The theory I have decided to use in this study is the sociocultural theory.

Analys av mellanspänningsnätet i centrala delar av Västerås stad

The dependency of continuous electricity supply is high in the Swedish society today, at the same time no one is willing to pay for a too costly or over dimensioned power distribution system. The owners of the distribution systems are the ones responsible for this balance act of maintaining a high quality of electricity delivery to customers at a reasonable cost.In this master thesis a limited part of the primary distribution system (10 kV), owned by Mälarenergi Elnät AB and located in the city centre of Västerås, was chosen for a deeper analysis of its reliability. Its ability to handle outages of system components (N-1 and N-2 contingency analysis) was investigated to find out potential weak spots and parts of the grid that showed signs of being overdimensioned.The results of the performed simulations showed that in 74 % of the studied N-1 contingencies cases, consisting of outages of a bus bar in a distribution substation, the system could handle this without causing outages in other parts of the grid. For the N-2 contingencies 61 % passed the test. It was also found that one of the two included high voltage substations could alone supply the investigated part of the grid.

Förvaltningsfastigheter : Den globala finans krisens påverkan på svenska börsnoterade fastighetsbolagens nedskrivningar

Introduction and background: The 1990s crisis and the global financial crisis year 2008 shows the same indications that the property market was affected negative. The Swedish Property companies had a difficult time on the market when the crisis led to decreased property trade and financing problems for the Property companies. The Swedish property companies became less attractive on the market and contributed to a drop in prices on investment property.Purpose: The purpose of this essay is to examine if there is any relation between the Swedish Property companies impairments on their investment property and the global financial crisis year 2008.Method: The essay is based on a quantitative study where we examined Swedish Property companies? annual reports. We answered our questions and our purpose from the empirical data that we collected from the annual reports.Conclusions: The study resulted in that we found a correlation between the Swedish Property companies? impairments on their investment properties and the global financial crisis year 2008.

Uppfyller BIM förväntningarna som arbetsmetod för broprojekt?

The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.

Vart tar fotbollsungdomarna vägen? : En studie om varför 15-16 åringar i Västerbotten väljer att lämna fotbollen

Eriksson, Simon & Ögren, Andreas. (2011). Vart tar fotbollsungdomarna vägen? En studie om varför 15-16 åringar i Västerbotten väljer att lämna fotbollen. (Where do the football youths go? A study of why 15-16 year olds in Västerbotten choose to leave football) Bachelor Essay in Swedish.

Bröd vid död i Kalvshälla : Analys av förhistoriskt organiskt grav- och boplatsmaterial från Barkarby i Järfälla socken, Uppland

This paper deals with prehistoric charred organic material, interpreted as bread, found in graves and in the underlying settlement at Kalvshälla, Järfälla parish in Uppland. The aim was to categorize the organic material morphologically and with the help of Fourier transformed Infrared spectroscopy (FT-IR) to see whether it was bread or not. Material from 13 graves (dated to Late Roman Iron Age until Viking Age) and 3 finds from the settlement have been analysed. Differences were noted both in shape, porosity and structure. Some of the material has been interpreted as cereal based foodstuff instead of bread due to morphological discrepancies.

Utvärdering av regnmätning och droppstorleksfördelning från en distrometer

Nederbördsmätning är viktigt inom många områden och en relativt ny teknik är enoptisk distrometer som med hjälp av laserteknik mäter nederbördspartiklarnasdroppstorlek och fallhastighet. Syftet med detta arbete var att undersöka hur välThies distrometer stämmer överens med nederbördsmätning från ett vippkärl ochmanuella mätningar från institutionen för geovetenskaper vid Uppsala universitet.Institutionen för geovetenskaper överväger att gå över till denna teknik och därmedbehövdes distrometern utvärderas för olika faktorer som kan påverka instrumentet.Vid jämförelse mellan instrumenten visade det sig att distrometern totalt sett samladein mer nederbörd än de andra mätarna. Det är svårt att avgöra vad skillnaden mellaninstrumenten kan bero på men felkällor så som avdunstning och vätning hos vippkärletoch manuella mätningar kan ge mindre nederbörd. En annan orsak kan varafelkalibrering av datan från distrometern. Inga samband hittades för vindhastighet,vindriktning och typ av nederbörd mellan de tre instrumenten.En vidare undersökning gjordes för droppstorleksfördelningen för att ge exempelpå fördelar med en distrometer.

Avbrottsfri Kraft med användning av ultrakondensatorer

The supply of uninterruptible power can be applied to many areas wherecontinuous operation is highly prioritized.The application of uninterruptible power for motor operation is facilitatedusing a frequency converter. Direct current operated frequency converters canbe applied directly to the power reserve which removes the need for additionalpower-converting.Batteries have long constituted the power reserve but advancements inthe development of ultracapacitors have created a viable substitution. Ultra-capacitors have high energy storing capabilities and can be applied to highpower applications.Maxwell is a leading manufacturing company of ultracapacitors and pro-vide different modules with built-in solutions for voltage balancing. Unevenvoltages between series-connected capacitors is a phenomenon caused by vary-ing capacitance. A configuration containing Maxwell?s 56V module is createdand constitutes the power reserve in the simulations.The discharge simulation shows a significant current that could damagethe system.

Idrotter på Kronoparken : En kvalitativ studie om flickors syn på Kronoparkens idrottsutbud

Kronoparken is a multicultural area with more than 100 different nationalities. Since we know that girls with a foreign background participate less in sport than girls with Swedish background do, we think it would be interesting to examine what kind of thoughts and experiences young girls on Kronoparken has about sport.  The purpose of this study is to examine what the girls think about the activities that are offered today. We also want to examine their thoughts about sport and gender issues.Since the aim is to identify the girl?s experiences around current activities and find out what ideas they have to improve this, we think a qualitative method is best suited. We have chosen to do interviews with two focus groups.

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