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629 Uppsatser om Voltage measuring - Sida 24 av 42

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.

Säkerhetsanalys av brandbekämpning i kritiska utrymmen på Forsmark 1

In order to maintain a high safety level at a nuclear power plant it is important not only to measure the reliability of the components and systems of the plant, but also to investigate how the plant responds to human actions. One of the most hazardous situations in managing a power plant is fire occurring in critical areas. This study concerns the prospect of the local fire brigade to suppress a fire that has started in one of the most critical rooms for maintaining high reactor safety. The model created gives an indication on the possibilities of succeeding in suppressing a fire. In order to get a more reliable fire fighting the following advice are given:- Let the fire brigade go rounds in the plant together with the personnel, during which recommended fire suppressing methods are determined to avoid long preparation time in an actual situation.- Prepare rooms with two subsystems to make them partly with no voltage.- Give the fire brigade better feedback from actual events on nuclear power plants.- Education and training in suppressing fires in electrical equipment.The probabilistic safety assessment strives to be as realistic as possible.

Sponsring av idrott: en empirisk studie om interaktionen
mellan företag och elitidrott ur ett företagsperspektiv

The purpose of this thesis is to gain a deeper understanding of Swedish companies? use of corporate sponsorships as a tool for communication. The research describes motives and goals of corporate sponsorships, the selecting process and methods used in evaluating its effects. The empirical data has been colleted through interviews with two companies sponsoring athletics at a top level in Sweden. The study shows that the principal objectives and motives companies have with sponsorships are related to brand exposure, image improvement and relationships.

Underkambriska böljeslagsmärkens bildningsmiljö : Ett försök att fastställa fossila ripplars avsättningsmiljö med hjälp av recenta sandbottnar

ABSTRACTThe fauna of the Lower Cambrian is far from fully understood, as is the environment of that epoch. Some of the most crucial moments in the history of evolution takes place during this epoch; the Cambrian explosion and the appearance of ecosystems as we know them. That makes it an important period to investigate. Doing so, the Lower Cambrian offers a lot of problems, one of which is that body fossils are seldom preserved. That has often left us with trace fossils to create an image of the Lower Cambrian life, but also some bedrock features such as ripple marks.The main purpose of this work has been to investigate the possibilities of relating the wave lengths and forms of recent wave-generated ripples to fossil ones, and also to evaluate the methods for that kind of comparison.

PSQS ? Power Supply Quality Simulator

Kitron had wishes to be able to test and measure how disturbance affects their vehicle electronic units before they have been verified by SP Technical Research Institute of Sweden in Borås. This work started with the writing of a demand specification together with Kitron for a product PSQS, Power Supply Quality Simulator, which can generate some test pulses according to a standard for electronic units to Volvos vehicles. A design proposal was developed with the help the demand specification and was verified with the help of simulations. All electric schematics was designed with the guide of the design proposal. The pulses realized in the works of this thesis are those which Kitron experienced that they have a need to test in their own premises and which are possible to generate with the means available.

Skalkonstruktion : Med inriktning mot hållfasthet och dämpning av ljud

The sound part is mainly practical and is dependent on concepts that have been tested through measuring with a sound level meter. The design part is more theoretical and has been verified with CAD models and finite element analysis.With a sound damping hood on the compressor the sound level is reduced with up to four dB. An optimized absorbent for the compressor space gives a reduction with three dB. By using the insulation for the heat water tank as absorbent we can see a sound reduction on the lover octave bands. A reduction like this is elsewhere hard to achieve as at it requires thick absorbents.By changing the today?s insulation to the heat water tank to a form of polystyrene polymer insulation the weight from the heat pump above can be transferred to the stable heat water tank.

Styrkor och svagheter med problembaserat lärande-en metastudie

AbstractProblem-based learning (PBL) was from the beginning developed in medical school, but is today used in education in other programmes as well. Investigations about PBL have been conducted in different disciplines and there is also metastudies. In this paper, a metastudy of 8 bachelor degree papers have been conducted. The questions answered were: which methods were used to investigate PBL in primary, lower secondary and upper secondary school,which advantages were found in working according to the PBL method, which disadvantages were found in working according to the PBL method and did teachers and students views about advantages and disadvantages about PBL as a method differ and if they did, how? The results showed that mostly qualitative methods were used to investigate the PBL as a method, mostly abilities of social qualities and independence were trained in working according to PBL, a disadvantage was that working according to the PBL method was considered more resourse consuming than traditional teaching methods and teachers and students views about PBL did not differ considerably.

Biogasanvändning vid Käppalaförbundets Reningsverk: ? en värdering av miljöeffekter

This thesis calculates and compares the values of improved environmental quality due to future possible investment alternatives in biogas production facilities at Käppalaförbundets Reningsverk (Käppala Sewage Treatment Works) in an attempt to determine which alternative yields the highest such value. Käppala faces three investment alternatives for the usage of biogas. The alternatives are production of vehicle fuel, district heating and thirdly, heat and power production. Estimates of the value of environmental change are calculated for each of the three investment alternatives, and these estimates are then compared. The environmental change in question is the change in discharge levels of carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and particle matter.

Fukthaltsförändringar för skogsbränsle : En jämförelse av torkförloppet i grönrisskotade och brunrisskotade vältor

In 1994 a new Forestry Act was accepted in Sweden. One of the aims of the law is to raise consideration forpreservation of biodiversity. Since the new law got accepted and some time has passed, there now lie someinterest in examining whether the law has been effective towards its purpose. Methods suitable for analysishave been examined during this study. The content of this pilot study is based around five parameters whichcan be used to validate the effects of the new law.

A First Effort to Visualize Knowledge of a Region? A visualization of Öresund & Shenzhen in the perspective of Knowledge Innovation Zone

We have through our theoretical framework been able to create a simplified measuring tool for a KIZ; the S-TKL. We have found that the S-TKL is possible to implement on the Öresund Region but with some flaws. Even though the Öresund Region has implemented the mindset of a KIZ, accurate statistics are in some areas hard to find. We can also through our empirical findings say that it is difficult to use the S-TKL on Shenzhen. The data we have found gives a good indication of both of the regions.

Tredimensionell sensorscanner

This report is a bachelor thesis presented at the department of Computer Science andEngineering at Chalmers University of Technology. The aim for the project is to find a simplemethod to measure and display physical quantities in a three dimensional room.The report describes a method to construct a system for measuring differentphysical quantities via sensors. The system must be built in a modular and expandable way tobe adaptable to different tasks.The system explained in the report consists of two parts;A physical scanner with moveable probes for carrying sensors and a microcontroller forcontrolling the probes and communicating with the next part.An application written in Java for storing the measured values and presenting them in a lucidperspective.It is possible to construct the scanner with different designs and circuitry, with multiplexers andflip-flops, to ensure that an unspecified number of probes can be added to the system and thatthey can be operated simultaneously.The Java application is written in a modular way, using a design pattern that separates eachindividual part of the application. It contains exceptions and interfaces that ensure a safe andexpandable application..

Spänningsfall i 200 V 400 Hz system

Målet med examensarbetet har varit att ta fram teoretiskt underlag och en beräkningsmodell. Detta ska beskriva hur kabeltyp, kabellängd, kabelarea samt effektfaktor påverkar spänningsfallet över ett 400 Hz ledningssystem.Mätningar har utförts på två olika kablar som används i det aktuella systemet. En av kablarna var symm­et­riskt uppbyggd med 7 ledare, där respektive fas bestod av två ledare förskjutna 180° från varandra runt nolledaren. För att åstadkomma 115/200V 400 Hz, användes en 90 kVA frekvensomformare. Belastningen som användes var en resistiv, induktiv samt en kapacitiv belastning.

Ideella organisationer på Twitter : En kvantitativ innehållsanalys av svenska jämställdhetsorganisationers användning av Twitter

Previous research on Twitter use among nonprofit organizations has been centered on the US, thisessay Nonprofits on Twitter: a content analysis of Swedish nonprofits working for gender equalityseeks to expand that research to include nonprofit organizations operating in Sweden. By studying tenSwedish nonprofits all working to achieve gender equality this study can begin filling a gap in theexisting research. Focusing on both what kind of messages the organizations publish, and what kind ofmessages engage the organizations? followers. This is achieved by quantitative content analysis:categorizing messages into the categories Information, Community and Action, and measuring whichof these categories got the most shares, comments and likes.

Numerisk simulering av jordtryck mot rörbro ? Med tillämpning av programmet PLAXIS

This thesis deals with numerical simulation of earth pressure against tubular bridges in the software Plaxis. Plaxis is a FEM (Finite Element Method) software based on numerical calculations for which approximate solutions are developed through an iterative process. The program is specifically designed for soil and rock mechanical tests, such as voltage and deformation calculations in soil.The Royal Institute of Technology conducted in 2005, field tests on tubular bridges of corrugated steel, which was part of Ersa Bayoglu Fleners PhD (Bayoglu Flener, 2009). She studied how two different tubular bridges deformed during installation and filling. Tests and measurements were made during filling.

Energioptimering av industriellt tryckluftssystem

This report is a bachelor thesis presented at the department of Computer Science andEngineering at Chalmers University of Technology. The aim for the project is to find a simplemethod to measure and display physical quantities in a three dimensional room.The report describes a method to construct a system for measuring differentphysical quantities via sensors. The system must be built in a modular and expandable way tobe adaptable to different tasks.The system explained in the report consists of two parts;A physical scanner with moveable probes for carrying sensors and a microcontroller forcontrolling the probes and communicating with the next part.An application written in Java for storing the measured values and presenting them in a lucidperspective.It is possible to construct the scanner with different designs and circuitry, with multiplexers andflip-flops, to ensure that an unspecified number of probes can be added to the system and thatthey can be operated simultaneously.The Java application is written in a modular way, using a design pattern that separates eachindividual part of the application. It contains exceptions and interfaces that ensure a safe andexpandable application..

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