Sök:

Sökresultat:

4465 Uppsatser om Specific energy consumption - Sida 55 av 298

Undervattensvågbrytare - En modellstudie

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Tillförlitlighet hos trafikolycksklassificering

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

IT-utrustnings miljöeffektivitet : - En undersökning av Grön IT på Umeå Energi

The environmental issues have during the last decenniums gained an increased role in both the political arena and in the market economy. The society is therefore more knowledgeable about the environment and our impact on it. Through this enlightened state, stakeholders tend to put pressure on the organizations of today. They, more or less willingly, incorporate this responsibility to be a part of their business. Entrepreneurs in the environmental area have seen this rising market as an opportunity to gain market shares and other positive outcomes.

Tillsats av biokol till en svensk sandjord : effekter på lustgasavgång, kväveretention och andel vattenfyllda porer

In a column experiment the effect of three different biochars on nitrous gas emissions, nitrogenretention and water filled pore space (WFPS) were studied in a Swedish sandy soil, classified as aCryopsamment. Ammonium retention was positively correlated, while KCl-extractable ammoniumwas negatively correlated, with the specific area of the biochars. The question was raised whether thenegative correlation between extractable ammonium and biochar specific area reflects the amount ofammonium present in the soil or its extractability from the biochar, and whether methods forextracting soil mineral nitrogen, like KCl-extractions, have to be modified for application on biocharamended soils. There was a tendency of increased nitrate retention and KCl-extractable nitrate withbiochar and KCl-extractable nitrate was positively correlated with the specific area of the biochar. pHwas higher for all biochars compared with control, although the differences were not significant, andWFPS was lowered by biochar addition, significantly in one case.

Studier av koppar i mjölk : en prooxidant med negativa effekter på mjölkkvaliteten

The taste of the dairy product is probably the main factor determining consumer?s dairy products choice. Consequently it is of great importance that the product tastes good and as expected every time. Off-flavors in milk can be caused by for example oxidation of the milk fat. Since copper is a prooxidant, a high copper content in the milk can cause oxidation.

Upptäcka matematik utomhus : Vilket förhållningssätt till matematik utomhus har förskollärare som inspireras av olika pedagogiska inriktningar och hur beskriver förskollärarna att de arbetar med matematik utomhus?

This project investigated the current market regarding wireless net and the communication between the tools used for diagnostics/maintenance and an embedded system. Based on documentation obtained through interviews a demo system was created based on Bluetooth Low Energy (BLE) communication between an embedded system and an Android device.This report intends to describe the tools and methods used in the design of the demo system and the result of an analysis of the BLE communication.Bluetooth Low Energy is an exciting protocol with wide applicability within the industrial field. This project investigated the communicational possibilities between a Smartphone and a Raspberry Pi and based on the results that emerged the conclusion can be drawn that BLE is a protocol with many beneficial applications within industrial IT..

Energiförbrukning vid havspaddling

Syfte med denna studie var att undersöka energiförbrukningen vid havspaddling. Energiförbrukningen undersöktes i vila och vid två olika hastigheter (4 och 7 km/h), först med en olastad och sedan med en lastad kajak (20 kg). Dessutom undersöktes hur det passiva motståndet förändrades vid successivt ökad hastigheten. Studien genomfördes i en försöksgrupp med jämn könsfördelning och med varierande ålder och paddlingserfarenhet.I studiens första del uppmättes försökspersonernas hjärtfrekvens i förhållande till syrgasupptag och koldioxidproduktion vid en successivt ökad belastning i en kajakergometer. För varje försöksperson kunde sedan en korrelationskurva beräknas mellan hjärtfrekvens och syrgasupptag.

Utvärdering av olika sätt att hantera avloppsslam i Värmdö

Important issues for the local authorities are what to do with the sludge produced insewagetreatment plants. The tax for landfill leads to higher costs with 250 SEK/ton. On the 31December 2004 it will be forbidden to landfill sludge.In Sweden the yearly production of sludge is 240 000 tons, counted as DS. The phosphorouscontent is 3 % in sludge. The total yearly production of sludge gives 6000 tons of phosphorous.

Energieffektiv Linjesjöfart Till Och Från Gotland

The ferry traffic to Gotland is essential for the island?s ability to live and develop. Yearly, it transports 1,6 million passengers, 500 000 personal vehicles and 750 000 lane meters of freight with four Ro-Pax ferries. The traffic is controlled and subsidized by the Swedish government since 1971 in order to guarantee the inhabitants and industry of Gotland a satisfactory transportation service. As a consequence of the past decades increased traffic quality, mainly due to a decrease in crossing times, the traffic?s environmental impact and costs has also increased.The Master Thesis proposes a new energy efficient traffic arrangement that satisfies the users? preferences in the same extent as today.

Forsmark 3 ?Ett Framtida Biobränslekraftverk?

Recent turmoil surrounding nuclear power as an energy source, especially since the accidentat Fukushima, has largely contributed to the debate of whether or not nuclear power should beused as an energy source. This study has examined the economic feasibility of replacingForsmark?s 3rd nuclear reactor with a bio fueled power plant, and find out how this could bedone.The power generation that has to be replaced is equal to 1170 MWe. To replace this, 6 largescaleCFB-boilers, each providing over 200 MWe, were necessary. In addition to this, eachboiler required their respective turbine sets, comprising one high-pressure-, and one lowpressureturbine with intermediate reheating capacities.Based on this, a rankine-cycle was modeled using the software EES, to be able to calculatethe total heat required in the power plant.

Lokala skillnader i konsumtion av påväxtalger och terrestra löv hos en differentierad population av Asellus aquaticus

That ecological and evolutionary processes can take place on the same time scale is a recent insight. Today we also know that they are directly linked to each other. In the lake Tåkern, in year 2000, there was a structural change when phytoplankton declined and submerged vegetation, mainly stoneworts began to spread. This led to evolutionary changes in the aquatic sowbug, Asellus aquaticus which had previously been limited to the reed, most likely feeding on detritus. But then, sowbugs could exploit the new habitat in stoneworts and a new food resource in terms of periphyton.

Skogs- och energibolagens attityd till förnybara drivmedel vid upphandling av transporttjänster i norra Sverige

Sweden's government is dedicated to the goal of having a vehicle fleet that is independent of fossil fuels by 2030. Achieving these goals requires, among other things, new types of fuel that give lower net emissions of carbon dioxide. The present market includes stations offering lowlevel blends of renewable fuels in conventional diesel as well as some stations offering renewable fuels only. The purpose of this study is to survey purchasers? attitudes to the use renewable fuels in roundwood and bioenergy transport in forest- and energy companies. The study was based on qualitative interviews through a combination of face-to-face meetings and telephone interviews with each sample group. The total number of respondents was ten (10), consisting of five (5) from forest companies and five (5) from energy companies. Transport service purchasers were generally positive to renewable fuels and considered these necessary in the future.

Kompensering av reaktiv effekt vid vindkraftverk

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

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.

Är vinkritik nonsens - En explorativ studie av vinkritiker och deras bedömningsprocess i en kluven industri

With increasing wine consumption and a growing assortment at available to Swedish consumers, there is an interest in understanding the decision making process of Swedish wine consumers. In this thesis the expert phenomenon is studied with respect to wine through wine critic reliability: grading objectivity, understanding the process of wine criticism and possible critic influence on consumer behavior. Two studies were performed; a qualitative in-depth session of interviews with industry connoisseurs and a quantitative analysis of 589 online wine reviews. Our results indicate that wine reviews are highly subjective and defy prediction through analysis of external variables. Critics are likely to judge differently based on what information they have at hand, suggesting that expectations affect grading.

<- Föregående sida 55 Nästa sida ->