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1658 Uppsatser om Renewable energy - Sida 60 av 111
Optisk karakterisering av tunna SiO2/NiO-filmer syntetiserade med en sol-gelmetod
In an attempt to develop a more cost-efficient material for solar energy applications, nano-particles of nickel oxide composite in a silikatmatris manufactured with solar gelmethod and studied structurally by electron microscopy. Furthermore, the thin film optical properties characterized by Variable. Angel Spectroscopic Ellipsometry. Sol gelfilms suitability as a selective absorber surface is also analyzed by optical modeling..
Miljö- och samhällsekonomisk analys av behandling av biologiskt avfall
Biogas is a renewable fuel that can be extracted from anaerobic digestion of many differentsubstrates, for example biological household waste. An alternative handling of the waste is tomix it with other wastes and incinerate it in a combined heat and power (CHP) plant. Thisstudy uses life cycle assessment to investigate which type of waste handling that is betterfrom an environmental point of view, anaerobic digestion with biogas production orincineration. The results are based on a case study of a biogas production plant owned by thecompany Ragn-Sells in Vänersborg. The alternative is incineration at a CHP plant inGothenburg.
Miljöbyggnad i ombyggnadsprocessen : Miljöcertifiering av Jakobsbergsskolan i Kristinehamn
Climate change is an increasingly widely known concept. In the EU the construction sector is responsible for more than a third of the carbon dioxide emissions and 40 % of the total energy use. In Sweden, measures have been taken to prevent this climate change. By 16 targets, three of which can be linked to the construction sector, Sweden will reduce the negative trend. None of the three goals with relation to the construction sector will however be achieved before 2020.
Environmental impact assessment of energy recovery from food waste in Singapore : comparing biogas production to incineration
As a small and land scarce country, effective waste management is ofoutmost importance in Singapore. In this study the production of biogasthrough anaerobic digestion from the organic fraction of municipal solidwaste (OFMSW) was compared to incineration of the waste. At the momentalmost all of the OFMSW in Singapore is incinerated. Three differentscenarios were compared to the reference scenario (incineration): one with alarge scale biogas plant that can treat half of all OFMSW in Singapore, onewith a medium scale biogas plant about 15 times smaller than the large oneand one with a small scale biogas plant that can treat waste from e.g. ashopping center or a food center.By using life cycle assessment (LCA) the different scenarios were comparedin terms of global warming potential (GWP), acidification, eutrophication,energy use and land use.
Värmeöverföring i bergvärmesystem : En numerisk analys av den ringformade koaxiala borrhålsvärmeväxlaren
The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat exchangers. For this reason, the annular coaxial borehole heat exchanger (CBHE) has been analyzed. This type of heat exchanger is interesting in terms of both thermal and hydrodynamic performance. A model has been set up in the program Comsol Multiphysics in order to investigate the heat transfer characteristics along the borehole.
Designerrollen i en webbdesignprocess
This study investigates if, and in that case, how design theory is applied in practice in the web development field. Prior research has focused on methods used in the web development field. We wanted to study the designers role in a web design process by comparing existing designer roles with design theory literature. We did qualitative interviews with two practitioners at two different communication agencies in northern Sweden. Based on our qualitative data and literature review we have concluded that a designer has to devote a lot of energy on requirements engineering in order to develop a clear understanding of the design situation..
Sammankoppling av fjärrvärmenäten i Nyköping och Oxelösund : miljö- och systemkonsekvenser
District heating covers most of the residential areas and industries in the twoneighbouring Swedish municipalities Nyköping and Oxelösund. In Nyköping,Vattenfall AB Värme produces heat in a bio-fuelled CHP plant. In Oxelösund,waste heat and use of waste gases from the steel production at SSABOxelösund is the basis in the district heating system.This report examines the environmental consequences of a connection betweenthe two district heating systems. A broad system approach is used and the focusis on environmental effects in the system.A system analysis has been performed on the result of simulations of differentheat and electricity production alternatives. The alternatives simulated wereone where Vattenfall Nyköping covers the base load in the joint district heatingsystem and two where the power plant at SSAB Oxelösund supplies the heatbase load.The conclusion in this report is that the consequences of connecting the twodistrict heating systems can be both positive and negative, depending onsystem boundaries and on the environmental focus.
Effektiv lagerstyrning genom tillförlitlig prognostisering : Effective inventory control through reliable forecasting
This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.The background of the problem with moisture is that today?s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate.
Landskapsplanering ur ett hållbarhetsperspektiv :
Environmental problems are accelerating with energy consumption and the release of greenhouse gases as the major issues. This affects landscape planning mostly through environmentally hazardous transportation and heating of buildings. In environmental work, the term "Sustainable development" is often used. This term was coined in the Bruntland report in 1987. A number of frameworks have been developed to clarify the term and to remind the user about relevant aspects of sustainability.
Hur bör unga hundar av storvuxna raser utfodras?
The dog is unique in the way that the adult weight can vary 100 folds between the different breeds. Despite this, most of the breeds reach adult size before two years of age. For the large-breed dogs this means a very rapid growth when some of them can have a weight gain of up to 150 times their birth weight. The most rapid growth occurs when the puppies are between three to six months old and that kind of rapid growth during such a short period of time makes these large-breed puppies very sensitive to deficits and excesses of energy, nutrients and minerals. Some examples can be excess of energy, excess or deficit of minerals such as calcium and phosphorus or deficits of protein.
The rapid growth can also make the large-breed puppies predisposed to some diseases affecting the skeletal and joints.
Fireball 2 : Energieffektiv fiber produktion
The development within the textile industry is always ongoing with development of new andbetter textiles, which often mean the use of non-natural materials like polyester. This doesn?t lineup with the work shared around the world against an improved environment, so the idea came touse a form of linen fibers instead of polyester as the reinforcing material together with cotton.The idea was to use flax, linen of low quality, which is seen as a waste product and garbage inthe production of high quality linen and flax seed oil. This flax of low quality needs to beseparated before it can be used in cotton spinning machines. Fireball 2 is just that, a process toseparate flax fibers through the treatment of a technique called electrohydraulic discharge.The thesis works goal is to evaluate the Fireball 2 process ability to separate flax fiber.
Pre-treatment of grain for ethanol production during storage
Ethanol for automotive purposes is an issue much debated and researchers disagree about the benefits of bioethanol. Converting energy-rich crops into ethanol suitable as motor fuel is a complex process and continuous development and improvements of processes and material used are important steps in the work of developing environmental friendly fuels. Grain is usually preserved by drying which consumes a lot of energy. Alternative storage of high-moisture grain in airtight storage systems reduce the energy required to produce bioethanol and studies have also shown that ethanol yields are increased more than 10% in ethanol fermentations of moist grain compared to dry. Airtight storage is often not perfectly airtight so biocontrol agents are necessary in order to preserve the grain.
Fukthalt i GROT - påverkande faktorer :
This study was carried out at the request of the bio energy company Naturbränsle. The company handles annually 750 000 m3 of chips from logging residues from a large area, from Östergötland in the south to Härjedalen in the north. In that area, about 50 bio fuel plants are customers. When Naturbränsle deliver chips from logging residues to their customers, the moisture content varies from 30 % to 60 %. The aim of the study was to sort out the affecting factors on the moisture content in the chips during handling and storage processes.
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..
Beräkning av byggnaders energiprestanda med anledning av energideklarationerna.
Europaparlamentet antog i december 2002 ett direktiv om byggnaders energiprestanda.Direktivet kräver att byggnader skall energideklareras, alltså undersökas och dokumenteras urett energiprestandaperspektiv. Direktivet har hittills resulterat i två svenska delbetänkandensamt ett slutbetänkande. Dessa tre skrifter kommer att ligga till grund för den svenska lagenom energideklarationer. Enligt SOU 2005:67 skall energiprestandan beräknas för samtligasmåhus och nybyggda hus. För flerbostadshus och byggnader med lokaler skallenergiprestandan beräknas då det inte finns några uppgifter på byggnadens energianvändning.Eftersom byggnaders energiprestanda är en central del av energideklarationerna ägnas det enutförlig analys av olika energiflöden ut ur och in i en byggnad.