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739 Uppsatser om Organic rankine cycle - Sida 12 av 50

Livscykelanalys för koldioxidutsläpp från flerbostadshus

Today, about 15 to 20 percent of Sweden?s total emission of carbon dioxide can be traced to the household sector. By examining apartment blocks in a life cycle perspective, the origin of the carbon dioxide emission has been charted and analyzed. This information has been used to create a computational model that calculates the total emission of carbon dioxide from a specific apartment block. The results from the analyzed apartment blocks indicate that both the use of energy and the emission of carbon dioxide have been reduced since the 1960s. Through the examination of building materials, it is possible to lower the emission of carbon dioxide that origins from the construction phase of an apartment block.

Löslighet och metylering av kvicksilver i en förorenad sjö (Ala-Lombolo) i Kiruna kommun :

Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) is a biotic process that is proposed to be conducted primarily by sulphate reducing bacteria (SRB). The formation of MeHg is of great interest because it is the mercury species that biomagnifies to the greatest extent in the aquatic food webs; about 90 % of all Hg in fish is MeHg. Our understanding of factors involved in the production of MeHg is very important for making a reliable risk assessment. The purposes of this study were to investigate the different factors that control the solubility of Hg and the production of MeHg in a contaminated lake sediment. The lake Ala-Lombolo, Kiruna municipality, is well-known to be contaminated by mercury from different sources. Sediment cores were sampled at three different locations (N, SW and SE) in the lake and divided in three different layers; 0-5, 5-10 and 10-15 cm.

Klövhälsa registrerad vid rutinmässig verkning i lösdrift eller uppbundna system med ekologisk eller konventionell mjölkproduktion :

KRAV-certified organic dairy herds generally have a lower milk yield than conventional dairy herds. A high-level of milk yield requires a feeding regime with high amounts of concentrates, a factor known to contribute to the development of claw lesions (Bergsten, C. 2003). The aim of this study was to compare claw health between organic and conventional dairy herds in free and tie stall systems. The number of herds from different domestic animal health associations was chosen in proportion to the association´s total portion of Swedish dairy producing herds of each type, respectively.

Miljöutredning på Care of Haus : För och nackdelar med ISO 14001

Today many companies and municipalities requires that their suppliers should have an environmental management system to work by. This might be one of the reasons to the increasing number of companies that today are implementing environmental management systems. Care of Haus is one of the companies that thinks that the benefits are bigger than the disadvantages, when it comes to environmental management systems, therefore they have made the choice to work with ISO 14001.The ISO 14001 standard is deified on the PDCA- cycle. PDCA stands for Plan, do check and act. Care of Haus choose to work with the ISO 14001 standard since it is a well-known standard for the companies that?s Care of Haus collaborates with and it is also well-known within their clienteleWithin this report an environmental investigation has been made.

Är kolrika jordar en källa till fosforläckage? : en sammanställning av data från 130 åkerjordar

Phosphorus (P) is an essential nutrient but a surplus could lead to eutrophication. Furthermore, the minerals used to produce the mineral phosphate is a non renewable resource. There are in other words several reasons to reduce the leakage of P and the agriculture is one important area to attend. The aim of this work has been to investigate if carbon-rich arable soils content contain more P than arable soils with low carbon content. Moreover it has been calculated if the carbon-rich soils could pose a risk of P leakage by comparing their delivery of P with the plant uptake. The work has consisted of compiling the results from former gathered and analysed soil samples of 130 Swedish arable soils. The fractions of P considered are water soluble P (Pw), ammonium lactate-extractable P (P-AL), hydrochloric acid-soluble P (P-HCl), organic ammonium lactate-extractable P (Porg-AL) and inorganic ammonium lactate-extractable P (Porg-HCl).

Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam

Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as a complexing agent for heavy metals and in this way increase their mobility.

Outnyttjade resurser inom park- och naturvård

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.

Dynamisk investeringsstrategi på den svenska aktiemarknaden

The purpose of this paper is to investigate if a dynamic investment strategy on the Swedish asset market can accomplish better returns then a static investment strategy. The dynamic investment strategy is created by incorporating business cycle predictors and firm-level variables to predict future stock returns. The predictive regression is calculated wih 60 months of observation (1999 01-2005 12) and is then used to estimate future returns for 23 months in the period 2004 01 -2005 11. The structure of the regression, with linear functions of ? and ?, goes back to Shanken (1990) and Avramov and Chordia (2005) has had success with the variables chosen.

Utvärdering av lämpliga metoder för vattengenerering

This master thesis has been performed at the department of Machine Design at KTH, The Royal Institute of Technology. The thesis has been a part of a global development project in collaboration with Luleå University of Technology, Lund Faculty of Engineering and Stanford University. Corporate liaison and sponsor has been Immerse Global Inc. The project was also performed on sponsorship from the Product Innovation Engineering Program, PIEp. The thesis is a representation of some of the contributions made by the authors.The lack of clean drinking water is one of the key issues facing the world today.

ALK?RR - K?LLA ELLER S?NKA F?R V?XTHUSGASERNA METAN OCH LUSTGAS? Empirisk studie av v?xthusgasutbyte i kustn?ra alk?rr p? den svenska V?stkusten.

Due to global climate change and the rising levels of greenhouse gases (GHG) in the atmosphere, the interest for seeking solutions for mitigation has increased. While much attention has been directed towards technical solutions such as carbon capture and storage (CCS), biogenic carbon sinks has also garnered significant attention. Previous studies have shown that coastal ecosystems such as seagrass meadows and mangroves have a much greater capacity for storing carbon (C) compared to terrestrial ecosystems. That raises the question if other coastal ecosystems, such as coastal wetland forests, that previously haven?t been considered as blue carbon habitats also contribute to coastal carbon sink capacity.

Analys och beräkning av emissionsfaktorer för växthusgaser

An increased awareness about the global warming has created a demand for more information on how the climate is affected by different activities.This master thesis was initiated by Tricorona, a Swedish company that offers its customers analysis and calculation of their climate impact. Tricorona also supplies climate neutralisation with CERs, in accordance with the Kyoto protocol and controlled by the UN. This work demands updated emission factors for greenhouse gases. An emission factor gives information about the greenhouse gasintensity of a service or a product [kg CO2-eq./ functional unit].The purpose of this thesis is to examine how electricity, district heating, hotels, taxis, food and materials affect the climate and how emission factors for these areas can be calculated.This was done by reviewing and comparing different studies and by interviewing experts. The information was evaluated and recommendations on calculations and emission factors were made.The consumption of energy is the main source of greenhouse gas emissions for district heating, electricity, hotels, taxis and materials.

Skogen i barnlitteraturen : Kan den fungera som en källa till naturvetenskaplig kunskap?

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.

Utomhuspedagogik : Några lärares uppfattningar om utomhuspedagogik och erfarenheter av att undervisa i utomhusmiljö.

Syftet med denna studie var att undersöka lärares uppfattning om utomhuspedagogik och erfarenhet av att undervisa i utomhusmiljö. Respondentundersökningen utgick från de fyra frågeställningarna: Hur uppfattar lärare utomhuspedagogik? Vilka erfarenheter har lärare av att undervisa i utomhusmiljö? Hur uppfattar lärare elevers lärande i utomhusmiljö? Är det ett effektivt lärande som lärarna beskriver utifrån David Kolbs ?The Experiential Learning Cycle??Kvalitativa intervjuer användes som metod och genomfördes på tre olika grundskolor i mellersta Sverige. Den ena skolan har en miljö/naturprofil, de två andra skolorna har inte en miljö/naturprofil. Det insamlade materialet bearbetades med hjälp av en tematisk analys, samt utifrån David Kolbs erfarenhetsbaserade cirkel ? ?The Experiential Learning Cycle?.I studien redovisas lärarnas uppfattningar och erfarenheter, resultatet visar att lärarna uppfattar utomhuspedagogik som ett praktiskt arbetssätt där lärandet blir konkret.

Det ekologiska steget : En studie kring hinder och drivkrafter för lantbrukares val att bedriva ekologisk livsmedelsproduktion i Östergötland

Denna studie syftar till att identifiera vad det är som driver eller hindrar lantbrukare i Östergötland att ställa om sitt lantbruk till ekologisk produktion och huruvida de identifierade påverkningsfaktorerna skiljer sig åt mellan konventionella och ekologiska lantbrukare. Semistrukturerade intervjuer med tre konventionella samt fyra ekologiska lantbrukare genomfördes för att undersöka deras erfarenheter. Respondenternas erfarenheter redovisas i sex identifierade teman; Gårdsspecifika förutsättningar, Ekonomi, Politik, Administration och regelverk, Miljö och hälsa samt Produktionsteknik. En jämförelse mellan de båda grupperna genomförs och det empiriska materialet ställs mot tidigare forskning. Resultatet av studien visar att skillnader mellan ekologiska och konventionella lantbrukares uppfattningar kring hinder och drivkrafter förekommer, men inte inom alla teman.

Sedimentation av lera och fosfor i en anlagd våtmark

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.

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