The requirements for wastewater treatment plants (WWTP) are gradually increasing, partly because of higher incoming loads, which in turn require a more efficient treatment process. In parallel with environmental and economic goals there are also desires to lower energy consumption without compromising the wastewater treatment. Furthermore, there is a demand on WWTP´s to alter eutrophication in aquatic systems through better nitrogen and phosphorus removal. An increasing number of WWTP´s have acquired biological nitrogen and phos-phorus removal. A by-product of this type of biological treatment is the formation of nitrous oxide, which is a potent greenhouse gas.

Denna rapport handlar om optisk koherenstomografi, Optical Coherence Tomography (OCT), en relativt ny teknik som blivit allt mer attraktiv på sjukhusens ögonkliniker. En OCT-apparat används bland annat för diagnosticering av ögonsjukdomar lokaliserade i gula fläcken och runt optiska disken. I maj 2007 köpte Ögonkliniken på Blekingesjukhuset in en 3D OCT-1000 av märket Topcon. Hos denna OCT-apparat finns en mätfunktion, Caliper, som mäter näthinnetjocklek. Studien i denna rapport syftade till att ta reda på vad Caliper mäter, hur den mäter och om den går att lita på. En OCT-undersökning utfördes på tio testpersoner.

The debate on the future of Nuclear power in Sweden has increased with the discussion on global warming. The uncertainty of fossil fuel- and carbonprices the latest years has aroused considerable interest in Nuclear from power companies, industry and politicians. Nuclear power plants have negligible CO2 emissions and are not directly affected by increased price of emission rights and fossil fuels. The future power production needs to reduce its emissions of greenhouse gases to become sustainable. The purpose of this study is to examine the value for power producers to have the option to invest in Nuclear power and how a Nuclear power venture would affect future electricity prices. The study uses two methods, a traditional cash flow model and real option analysis, to estimate the value of Nuclear power.

Denna rapport behandlar utveckling av en tvåhjulig balanserande robot. En PID-regulator är implementerad i en mikrokontroller, som även AD-omvandlar en sensorsignal, samt styr motorer via H-bryggor med pulsbreddsmodulering. I rapporten förklaras framtagning av diskret PID-regulator, processorkort, motorkort, val av komponenter och sensor för att mäta robotens vinkel mot ett vertikalplan.Roboten kan balansera stillastående, men behöver kompletteras ytterligare med hjulåterkoppling för att kunna balansera medan den kör. Roboten balanserar med mätdata från en mekanisk golvavkännare (potentiometer). Andra sorters sensorer diskuteras också, t ex accelerometer, gyro och optisk sensor..

This thesis was carried out to give some background information to a report of SLU (Swedish University of Agricultural Sciences) for the Swedish National Rail Administration (Banverket). The requested information was to provide basic data for an environmental impact assessment of the construction of the tunnel through Hallandsås. The aim with the thesis work was to discuss and quantify the leaching of nitrate and the emission of nitrous oxide from the soil at the groundwater level established through the tunnel project. The nitrogen related processes that could be affected were described and discussed. The different areas where a decreased groundwater level can cause changes in the nitrogen processes are the wet and moist areas.

This bachelor thesis has the purpose to visualize and document the air movementsprovided by different ventilation principles in an operating theatre. The visualizationwill be made as simple as possible in a physical model. The model and thedocumentation should be able to use in educational purposes.The study is based on the two most common systems for airflow, currently used inoperating theatres. The first principle is displacement ventilation in which the air issupplied at low velocity along the floor. The second principle is vertical parallel laminarairflow in which the air is compressed like a piston from ceiling to the floor.A review of literature resulted in the choice of size, design, and scale factor for themodel, as well as choices of ventilation principles and airflows.

This report analyzes disposable packaging and returnable packaging with the methods life cycle analysis and life cycle costs analysis. These two different packaging are analyzed through the company Clas Ohlson?s packaging-flow. To get a picture of how the flow works, a visit at the company and email contact have been done with Clas Ohlson to get relevant informationToday Clas Ohlson has a big flow of articles to the stores without larger variations in the demand, with the exception of autumn, which is when customers start shopping for Christmas. Clas Ohlson?s articles are placed on a pallet and are wrapped into plastic-film for protection and to make sure that nothing will be stolen.

Energy is an important issue in the current world which significantly affects sustainability and development. Energy generation and use are major sources of CO2 emissions which is one of the most important driving factors in global climate changes. The amount of energy used in house hold section can lead to estimation of the amount of CO2 emitted within this section which subsequently would be a ground to better management and maintaining a sustainable society. This study which is a bachelor?s project in sustainable energy, deals with estimation of CO2 emission from different types of residential houses in Sweden. An extensive literature review on energy use in Sweden by different residential sectors has been conducted.

Halmstad kommun ingår i Hallands län, som utifrån de 16 nationella miljökvalitetsmålen utformat 16 regionala miljökvalitetsmål. Miljökvalitetsmål nummer 15 ?God bebyggd miljö? säger under delmål fem att till år 2010 skulle kommunerna ha utsorterat och behandlat 35 % av matavfallet biologiskt. Idag finns det i kommunerna inget nytt antaget mål angående insamling av matavfall, utan målet från 2010 består. Halmstad kommun sorterar idag ut 6,8 % av matavfallet från verksamheter och har därmed en bit kvar för att uppnå det regionala miljökvalitetsmålet ?God bebyggd miljö?.

The capacity to extract information from vehicles has the potential to be very beneficial. Performing analysis on information about fuel usage, emission values and other driving properties of a vehicle can lead to great economic and environmental benefits.This report contains descriptions of two prominent systems for retrieving information of this nature from a vehicle, On-Board Diagnostics and FMS-Standard, and of an implementation of FMS-Standard.The conclusion drawn after this investigation is that these systems do indeed offer access to the benefits mentioned earlier, although to varying degrees and with differing prioritisation..

För att minska utsläppen av koldioxid har länderna inom den europeiska unionen enats om att införa ett system för handel med utsläppsrätter. Handelssystemet infördes 2005 och skall i sin första period pågå fram till 2007. Genom att systemet är marknadsbaserat så bestäms priset på utsläppsrätter genom utbud och efterfrågan på marknaden. Företag som inte innehar tillräckligt med utsläppsrätter måste således köpa utsläppsrätter av andra företag som säljer utsläppsrätter på marknaden. I en tidigare studie anses miljökrav likt handel med utsläppsrätter vara av strategisk natur för företag.

GE Healthcare operates in Uppsala (Sweden) and develops systems, equipments and medium to purify medical substances. Discussions with the local authority concerning planed far-reaching changes and upgrades of the biological process techniques for sewage management, aroused the question about revising the terms of permit for the activity. Therefore it seemed necessary to evaluate a newly installed biological process technique, which is the background of this thesis. The evaluated biological treatment process was built in 2003 and consists of a biological reactor filled with moving bed carriers with a high surface area for biological growth. At the time of the project the biological wastewater treatment plant consisted of a flow equalization facility and two following parallel biological processes; a biological reactor with moving bed carriers and a tower trickling filter.The aim of this thesis was to survey the function of the biological reactor with respect to the reduction of organic matter.

Methane (CH4) is a greenhouse gas (GHG) that contributes to the global warming. One of the largest sources of methane is livestock, preferably ruminants which alone counted for 30% of the total agricultural anthropogenic methane emissions in the year of 2000. The reason to why ruminants are such large contributors of methane are that the gas is produced in the rumen by enteric formation and leaves the animals by belching, exhaling or by the excreta.Diets high in concentrates can result in a lower emission of methane. Also diets with a high content of starch, such as alfalfa-grass, have a methane-decreasing. It is profitable to reduce enteric methane formation since that form of methane is unavoidably lost.

Hammarby Sjöstad is a new district in Stockholm with high environmental standard. Stockholm Water Company evaluates a local wastewater treatment plant with cutting edge technology. The first step is an experimental treatment plant (Sjöstadsverket) with four parallel lines of treatment, each with a capacity to treat wastewater from 150 persons. Within the membrane technology subproject the possibility of using reverse osmosis (usually called RO) to regain nutrients is examined.Reverse osmosis separates the incoming water in a clean permeate and a concentrate that, as the name indicates, is a more concentrated version of the incoming water. Using this method in wastewater treatment, a solution high in nutrients can be obtained without the use of chemical precipitation agent and with no production of sludge.

Havsmiljöer är idag den slutliga anhalten för den nedskräpning av plast som kommer ifrån avloppsvatten och allmän nedskräpning. Stora mängder plastpartiklar i olika storlekar har upptäckts i haven och även inuti djur som misstagit plasten som föda. Forskning visar att en stor del av plasten är av mikroskopisk storlek, så kallade mikroplaster. Inom denna grupp förekommer textilfibrer som likt andra plaster är svårnedbrytbara i naturen. Det har genom studier påvisats att små textila fiber rinner ut med avloppsvattnet och hamnar i haven.PET är en av de vanligaste plasterna och utifrån denna tillverkas polyesterfiber som är det i särklass mest använda materialet inom textiltillverkning.