This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

Micro-power wind energy convertors have recently increased in popularity. The reasons for this are among other things the increasing cost of electric energy and enviromental concern.In this thesis the connection of these micro-power wind energy convertors to the utility network is discussed. Electric standards for the connection of small production units is presented. Finally some calculations and measurements of electric quality are also presented. The utility network used in the calculations is part of Halmstad Energi och Miljö network..

Cooling down the indoor air can be done in several ways. One way is desiccantcooling which will be used at the Stockholm Arena. This method is used in airhandling units that use temperature changes and moisture fluctuations in the air. Oneof the steps is to add heat during the cooling process in order to reduce the relativehumidity of the exhaust air. The air passes thru an adsorptions rotor which thenabsorbs moisture from the supply air.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

The purpose of this thesis is to examine how investments are justified in the Swedish data center industry, with a focus on cooling equipment. This is achieved through semi-structured interviews with 20 different interviewees. These interviewees represent different facets of the industry and facilitate an understanding of which factors, such as: investment costs, operating costs, reliability, environmental impact and the influence of external and internal actors, come into play and to which degree they impact the investment decision-making process. The results show that primarily low operating cost in the form of low energy consumption is the driving factor when it comes to the procurement of new equipment. A lower environmental impact is a positive side-effect of lower energy consumption.

The purpose of this study was to investigate to what extent  young adults use media to create the image of themselves. The questions we wanted to answer was as follows: what does the media use of young adults look like compared to their attitudes towards media content; what awareness do they have of other young adults attitudes concerning media content; and finally, how do these attitudes affect their own media use?Media consumption is a great part of  the daily lives of young adults living in Sweden: the national  average media consumption is seven hours a day, for 15-24 year olds. This provides a new way for young adults to express their identity - by showing their use of different media content, they can change other's perception of themselves.The method we used in our study was a combination between a quantitative and a qualitative method. We first made a survey in three classes with senior year high school-students, in a Swedish school.

This report is the final step in the Bachelor of Science program in Building Construction Engineering, Department of Engineering Sciences, Uppsala University.The purpose of this study is to highlight the difficulties and possibilities that could involve the introduction of new energy efficient technologies and changing work around this technology. This study focuses on energy use at a construction site or other temporary workplace where so-called portacabins are in place to address the need for temporary facilities.The method for obtaining knowledge on the subject was mainly interviews with site managers working in Svevia AB's various activities. In conjunction with the interviews I visited construction sites and portacabins if it was possible.My most important suggestion to Svevia AB concerns a better organization in order to make poratacabins more efficient on energy and costs. The company should also evaluate and monitor the energy efficient portacabins that are in operation.Expected energy savings of new technology may not materialize if there are gaps in information, education, technical services and technical maintenance. It is very important to utilize the experiences of new technology.

I dagens samhälle blir det allt mer intressant att spara energi, dels med tanke på miljön och dels föratt minska på utgifterna. Denna energi ska sparas på ett sådant sätt att effekten för användarna blirså liten som möjligt.I denna rapport beskrivs hur ett reglersystem kan byggas för att minska energiförbrukningen hosväxthus genom att reglera belysningen på ett effektivt sätt. Systemet är helt automatiskt vilket göratt användarna inte behöver tänka på styrningen av lamporna alls när väl systemet är uppsatt ochkonfigurerat.För att styra lamporna på ett bra sätt mäts det inkommande ljuset med en PAR-sensor. Lampornatänds och släcks därefter beroende på ljusmängden och även på hur varmt, eller kallt, det är iväxthusen.Styrningen av belysningen sker med en mikrokontroller från Microchip, en PIC18F4620 som ärprogrammerad i C18. Kringkomponenter som portexpasioner, klocka och reläer användes också föratt bygga ett bra reglersystem.Resultatet är att det är möjligt att bygga ett reglersystem med begränsad budget som styr lampornapå ett effektivt sätt.

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.