Because of the increasing trends in energy consumption and increased environmental awareness, greater focus has been placed on improvement and development of renewable energy sources. An already proven and accepted method is biogas production from anaerobic digestion at municipal wastewater treatment plants.In the waste water treatment process solid material and dissolved pollutants are separated from the water, forming a sludge. The sludge is separated from the process and stabilized during anaerobic digestion or aerobic aeration. Most often, mesophilic anaerobic digestion is used. Because of degradation by microorganisms, biogas with a high content of methane is formed during the digestion.

This project concentrates on musicians who work in a professional music studio.The task of this project was to design a new headphone system called Foldback system.The advantage of this system is that all involved in a music project could influence their ownlistening during the project. With a couple of adjustments should each and everyone get theirown individual listening from their headphone station.This report shows different methods, theories and results that came along in development ofFoldback system. The project has resulted in a finished product that will be in use atStudiomega..

The author of this report has created a Web-based invoice system and CRM at therequest of the company Webhouse.se. The purpose of the System is to makeeveryday tasks in the company easier. The system also needed to prevent mistakesand errors by managing orders and invoices.The system has been created with the company?s requests in focus. During thedevelopment of the system information security and interaction design have beenimportant aspects that have been taken into consideration.The system has been created using techniques such as PHP and MYSQL.

In order to reduce the price for, and improve the performance of automatic control systems for magnetization of synchronus generators, the possibilities of using a PC based software PLC system, Programmable Logic Controller, has been investigated. The result is a system based on the CoDeSys software PLC with runtime environment from 3S-Software, communicating with external units via Modbus fieldbus. System price is reduced from ?5000 to ?2000 and system processing speed is reduced from 10 ms for a Siemens S7 PLC to 4 ms with the CoDeSys PLC system though unsolved problems with runtime seizure caused by improper settings in the PC BIOS..

In this thesis a transport system is sought after thatif realised in the city of Uppsala could provide bothwell-being to all its inhabitants and sustainability,here jointly refered to as liveability. It is found thatthe car dominated transport system that is inoperation today provides two fundamental values,namely accessibility in both time and space, whichsets it apart from other transport solutions. Thesetwo values are of immense importance for theliveability in our modern world. On the other handthe car dominated system decreases the liveabilityof Uppsala in several different ways. Some of theseproblems, it is argued, could be solved within thecar system, through the adoption of moreenvironmentally friendly cars etc., but otherproblems are inherent in the car system and willremain no matter what changes are made.

Because of increasing demand of power on Malmbanan the capacity of the existing wires which supply the trains must be increased. This increases the stress on the existing poles and for this reason the system for supplying the loads along the railway is to be removed from the poles and be replaced by some other system. This thesis is a study on a two-level low voltage (1 kV and 0.4 kV) electrical system with the aim to investigate if it can be an alternative to the system used today taking into account the voltages, fault currents and costs.In this thesis the following tasks have been performed:? Gathering of data? Description of basic theory? Loadow and fault current calculations of the system with MATLAB? Life Cycle Cost estimate of the system? Analysis and conclusions from the resultsThe results show that the new system can be an alternative to replace today's system. The simulations and calculations show that the voltage drop is at an acceptable level and that the fault currents are large enough to supply a safe disconnection if a fault occurs at the far end of the system..

The management of information is a significant competitiveness in companies. Companies stored and save information every day, and it is very common to save de information in different sources. This makes de management of information complex. To mange, monitor and analyze the information, companies can use a system called Business Intelligence. BI system is an analytical system that extracts and converts data into useful information that helps employees to make informed decisions.

Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report. 1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven? The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.

This paper discuss the possibilities to improve the Swedish political nomination system. It brings up some of the values and norms that can be used to change the existing system. Values as openness, the demand of responsibility and also if there is values from the American spoils system that can be used in the Swedish system. A minor purpose is to discuss the part of the parliament within the nomination process. To investigate this I have some theoretical starting points and a self constructed analysis tool.

Human-computer interaction is central for computer assisted development. The aim was to investigate the user experience of a new (U2) compared to an old (U1) computer system, within a cognitive psychology frame of reference. Six subjects, frequently using the system, participated in the study. It was shown that the new (U2) compared to the old system (U1) enhanced and supported more the users? system related procedures/tasks.

Chemical stabilization of mine waste from Ljusnarsbergsfältet with sewage sludge and calcium carbonate residuesMine 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 dissolvedoxygen 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 complexing agents for heavy metals and in this way increase their mobility.

An automatic control system for calibration of pressure indicators has been constructed. This control system can be used as a complement to the calibration system located at AerotechTelub, division MainPartner, in Linköping. The calibration system used today contains some not wanted pressure changes, which is compensated by hand today. The new system presented in this report automates the calibrating process and simplifies the calibration. Suitable hardware as motor, controls card and so on have been found and software in the form of Visual Basic program has been developed.

The municipality, of Gatukontoret in Local government of Borås has in the long run, a required need to look after the current heating devices (the gas production plant) in sewage treatment plant, called Gässlösa. The practical work of the examination is about, trying to find a better way to take care of the current heat recovery. That may be one way or another, rather easy to implement in the existent construction.Through the work to increase the efficiency of the gas engine, implement of some external cooling system by heating exchange device. That gives an opportunity to heat (primary) the digester, (but even all internal public areas) with its own superfluous heating.The report shows that if the management group may invest 422 704 crown to implement a heat exchanging device, it gives more space to reduce the need to buy expensive external energy. Gatukontoret´s pay off time, for buying machines, is 20 years, with reservation to calculate with 4 percent internal interest, leads to the yearly mount of 31103 crowns.If Gässlösa increases the gas engine time in (effective) duty approximately (correspondingly) 48 hours a month the entire investment will generate a profit in January in year seven after the implementations.

The author of this report has created a Web-based invoice system and CRM at therequest of the company Webhouse.se. The purpose of the System is to makeeveryday tasks in the company easier. The system also needed to prevent mistakesand errors by managing orders and invoices.The system has been created with the company?s requests in focus. During thedevelopment of the system information security and interaction design have beenimportant aspects that have been taken into consideration.The system has been created using techniques such as PHP and MYSQL.

Studien undersöker om återföring av näringsämnen, huvudsakligen makronäringsämnena kväve och fosfor, från humanavlopp i Norrköpings kommun kan komma att ske på ett sätt som är i linje med naturvetenskapliga kretsloppsprinciper.Frågan om återföring av näringsämnen och dess problembild är av stor vikt då dagens flöden leder till både resursslöseri och miljöproblem som övergödning. Anledningen till att näringsämnen inte recirkuleras måste bero på någon form av oförmåga hos aktörerna att ta i tu med problematiken.Studien analyserar olika aktörers perspektiv. Aktörerna beskrivs dels i ett nationellt perspektiv men den huvudsakliga fokuseringen ligger på kommunal nivå. Detta på grund av att kommuners roll inom området innebär att de är ytterst ansvariga för utformningen av avloppssystem. Aktörer som agerar i förhållande till kommunen har därför undersökts närmare genom intervjuer med olika representanter för aktörerna.