mdh.sePublications
Change search
Refine search result
123 1 - 50 of 109
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Axelsson, Christer
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    HACCP-Implementering och tillsyn2008Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     

    The food-safety legislation in Sweden were changed and updated in 1996, much because of demands from the European Union for a common legislation regarding the food-safety issues in the EU. This report discusses how the Swedish authorities are dealing with the new legislation in Sweden. Further on the report presents how the food safety officers in the municipalities in Sweden are implementing this new legislation in their daily work, especially the requirements regarding the HACCP, Hazard Analysis Control and Checkpoints. The report shows that the implementation is quite slow and that many foodsafety-officers don’t implement the legislation in the same way all over the country. In some parts of Sweden the officers demands a complete Hazard-analysisplan with Critical checkpoints while in other parts of Sweden the are not the same demands. The reason to why this is possible may be the educational differences between the food safety officers in Sweden. In some municipalities the officers are well educated about the new legislation including HACCP while other municipalities don’t afford or take the time to educate their officers. The report also shows that the knowledge of the new legislation is poor among the people who work in the food-section.

     

  • 2.
    Bakhteyari, Karim
    Mälardalen University, Department of Public Technology.
    Public Private Partnerships: As a public infrastructure optimizer2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    A public private partnership is an alternative to procurement of the facility by the public sector, using funding from tax revenues or public borrowing. In a typical public sector procurement, the public authority sets out the specifications and design of the facility, calls for bids on the basis if this detailed design, and pays for construction of the facility by a private sector contractor. The public authority has to fund the full cost of construction, including cost overruns. Operation and maintenance of the facility are handled by the public authority and the contractor takes no responsibility for the long term performance of the facility after the construction warranty period has expired. In a public private partnership, on the other hand, the authority specifies its requirements in terms of outputs, which set out the public services which the facility is intended to provide, but which do not specify how these are to be provided. It is then left to the private sector to design, finance, build and operate the facility to meet the longterm output specifications. The project company receives payments over the life of the PPP contract, which are supposed to repay the financing costs and give a return to investors. The payments are subject to deductions for failure to meet output specifications, and there is no extra allowance for cost overruns which happen during construction or in operation of the facility.

  • 3.
    Campillo, Javier
    et al.
    Mälardalen University, Department of Public Technology. Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Foster, Stephen
    Mälardalen University, Department of Public Technology. Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Global Solar Photovoltaic Industry Analysis with Focus on the Chinese Market2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 4.
    Carlsson, Annika
    et al.
    Mälardalen University, Department of Social Sciences.
    Chogrish, Katrin
    Department of Public Technology.
    Hedersrelaterat våld: En textanalys av verklighetsbaserade berättelser om våld i hederns namn2007Student thesis
  • 5.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology. IST.
    Jones, Andrew
    International Paper, USA.
    Presentation of a dry black liquor gasification process with direct causticization2006In: TAPPI Journal, Vol. 5, no 3, p. 4-8Article in journal (Refereed)
    Abstract [en]

    In a new black liquor gasification process, black liquor is injected into a circulating fluidized bed, with sodium titanate (Na 2O· (TiO 23) as the fluidizing medium.The organics are gasified mainly by steam reforming because the temperature is relatively low (below 870°C) and the water content of the black liquor is relatively high (>20% water).The black liquor inorganics consist mainly of sodium carbonate and sodium sulfate. In the reactor, sodium carbonate is converted into Na 2O·TiO 2, which is removed from the bed and dissolved in water to give 4 NaOH + Na 2O·(TiO 2)3. After dewatering, this material is reinjected into the fluidized bed.The sulfate is reduced to Na 2S, and most of the sulfur is evaporated as H 2S after Na 2S reacts with CO 2 + H 2O. In a scrubber, the H 2S is selectively absorbed without CO 2. The direct causticization makes the lime kiln unnecessary. The gas is reheated after dust is removed and then combusted in a gas turbine/steam turbine cycle, to produce 2-3 times more electricity than produced in steam cycles with conventional recovery boilers.

  • 6.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Thorin, Eva
    Mälardalen University, Department of Public Technology.
    Yan, Jinyue
    Mälardalen University, Department of Public Technology.
    Alternative Pathways to a fossil-fuel free energy system in the Mälardalen region of Sweden2006In: Proceedings of the Second International Green Energy Conference, 2006, 2006, p. 822-830Conference paper (Other academic)
    Abstract [en]

    This paper presents a study on alternative pathways to a fossil-fuel free regional energy system in the Mälardalen region of Sweden with a population of 3 million inhabitants. We describe and address how the region can be made independent of fossil fuels by integration of resource management, technology advances, and behavior change in energy use. First we investigate the consumption pattern of the inhabitants. Then we study what resources are available, and how these can be used to fulfill the different demands. If we just use the resources in a pattern of business as usual today without changing the behavior, the balance between demands and resources is difficult to reach. By combining a slightly different behavior and a change of crops it could be possible to fulfill the needs. Some advanced technological solutions have also been proposed. For example, dedicated biomass energy plants such as fodder sugar beats can be used for ethanol production. Also Salix, straw, hemp and some cereals can be used and the residues can be gasified to produce dimethylether (DME), which is good as a replacement for diesel fuel. Still the fuel demand for transport is high, and the vehicle weight could be further reduced. For example, by going back to the car size we had only ten years ago the weight would be 25-30 % less, and fuel consumption would be at least 15 % lower. With diesel engines instead of Otto-engines the fuel consumption could be reduced by 35 %, and with hybrid technology additional 20% fuel reduction could be gained. Improved public transportation will also give a positive effect especially for those commuting between the larger cities and between the cities and the suburbs. The results of our calculations show that it would be possible to accomplish a fossil-free energy system in the Mälardalen region. The results of this study are important since it shows that an energy balance without fossil fuels could be possible for an area with a population in the order of 3 million people, which would also be valuable in studies of other areas in the world.

  • 7.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Dhak, Janice
    Mälardalen University, Department of Public Technology.
    Experiences of on-line and off-line simulation in Pulp and Paper industry2004In: Proceedings of the PTS-symposium, 2004Conference paper (Other (popular science, discussion, etc.))
  • 8.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Ekwall, Håkan
    ABB Industry, Västerås, Sweden.
    Dynamic simulators for process control and optimization as well as for operator training in pulp and paper industry2002In: Proceedings of the 43rd Conference on Simulation and Modelling: SIMS 2002, 2002Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    By using a dynamic physical model, that is adapted to real process data, robust mathematical process models can be created. By doing this it is possible to build in process know how from many different sources, and also to include factors, that are not easy to measure. From the dynamic model a training simulator can be made. From the dynamic model it may also be possible to do a model reduction to get an MPC, a Model Predictive Control. Data reconciliation is needed, to keep control of the measurements of all kind. A decision support system keeps control over the process status, to support operators. The production is also optimized at several levels. These functions may also be achieved by using principally the same mathematical models and algorithms.

  • 9.
    Danielsson, Erik
    et al.
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Robertsson, Hans
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Examensarbete: Prefabricerad produktion med betongelement: En kostnadsutvärdering mellan prefabricerad och platsbyggd produktion2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 10.
    Dotzauer, Erik
    Mälardalen University, Department of Public Technology.
    Produktionsplanering av el och värme - Matematiska modeller och metoder2002Report (Other (popular science, discussion, etc.))
  • 11.
    Eriksson, Olle
    Mälardalen University, Department of Public Technology.
    Tre stora industriella investeringar2002Doctoral thesis, monograph (Other scientific)
  • 12.
    Fagerberg, Nils
    Mälardalen University, Department of Public Technology.
    Är den svenska valutan anpassad för en långsiktigt hållbar utveckling?: – vilka brister finns och hur kan de åtgärdas?2005Student paper other, 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Money by definition is always a subjective human creation. Because of this it is unavoidablethat the physical and mental structure of a specific money system will have an effect on thesociety where it is circulating. With this fact as a starting point, the thesis is analysing whetherthe Swedish national currency, the crown, is consistent with a sustainable development. Theaim of the analysis is to: (a) identify the major shortcomings of the infrastructure of the crownin relation to its ability to support a sustainable development, (b) evaluate what possiblesolutions there are at hand to adjust for the shortcomings. The method used is purely based ontheoretical analysis, with emphasis on abstraction and causal simplicity.In a modern society, money is not only circulating as coins and bills, but also as digital assetstransferred directly between bank accounts. In the case of the Swedish crown, about 8 % ofthe money exists as coins and bills, while about 92 % of the money is digital. The coins andbills are created by the Swedish central bank, while the digital money is created by privatebanks and credit institutions. This privately created money exists with debt as a precondition.Someone has to make a loan, and thus create a debt, before the money can exist. On a societylevel these individual debts add up to a total debt which is growing faster than the amount ofmoney available to repay the debt, since the banking institutions are also charging interest ontop of each loan. The outcome is a situation where the debt becomes more and moreimpossible to repay and therefore it also creates a chronical shortage of money in society.This shortage causes several negative effects in society as a whole and on development ingeneral, leading to the conclusion that the Swedish crown is not consistent with an ecologicaland social sustainable development.The main problems could be solved by removing the right of private organisations to issuemoney and place this in the hands of a democratic public authority. New money should be putinto circulation without creation of new debt. The profits from issuing then become publicinstead of private, and the amount of money in circulation can be adjusted according to need.

  • 13.
    Fiedler, Frank
    Mälardalen University, Department of Public Technology.
    Combined solar and pellet heating systems: Study of energy use and CO-emissions2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    In this study 4 solar and pellet heating systems have been studied with the help of annual dynamic simulations. Two of the systems comprised a pellet stove and two systems were solar combisystems; one with a store integrated pellet burner, the other with a separate pellet boiler.

    The aim was to evaluate their thermal performance and their CO-emissions. The systems have been modelled based on lab measurements of the single system components. The used models allow a detailed study of the dynamic behaviour of the systems.

    The stove systems have the least primary energy consumption provided the auxiliary electricity is taken into account with a conversion factor of 100%. If the auxiliary electricity is taken into account with a conversion of 40% and/or the systems are placed in the heated area the combisystems need less or a similar amount of primary energy.

    Modulating combustion power reduces the number of starts and stops and for most pellet units this reduces the total CO emissions. The obtained annual CO emissions are higher than the values obtained from the standard test methods. It was shown that the average emissions under realistic annual conditions were greater than the limit values of two Eco-labels.

    The system performance can be significantly improved by a proper control of the pellet heater and by sizing the pellet heater according to the size of the peak space heating demand.

    Based on these findings from the simulations two prototypes of a combined solar and pellet heating system has been designed, built and tested; one for the lab and one that has been installed in a demonstration house. The system is very compact and is suitable for detached houses with no heating room or little space for a heating room.

  • 14.
    Fiedler, Frank
    et al.
    Mälardalen University, Department of Public Technology. Dalarna University College, Sweden.
    Bales, C
    Dalarna University College, Sweden.
    Persson, T
    Dalarna University College, Sweden.
    Optimisation method for solar heating systems in combination with pellet boilers/stove2007In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 4, no 3, p. 325-337Article in journal (Refereed)
    Abstract [en]

    n this study, an optimisation method for the design of combined solar and pellet heating systems is presented and evaluated. The paper describes the steps of the method by applying it to an example system. The objective of the optimisation was to find the design parameters that give the lowest auxiliary energy (pellet fuel + auxiliary electricity) and carbon monoxide (CO) emissions for a system with a typical load: a single family house in Sweden. Weighting factors have been used for the auxiliary energy use and CO emissions to give a combined objective function. Different weighting factors were tested. The results show that extreme weighting factors lead to their own minima. However, it was possible to find factors that ensure low values for both auxiliary energy and CO emissions, and suitable weighting factors are suggested.

  • 15.
    Fiedler, Frank
    et al.
    Mälardalen University, Department of Public Technology.
    Bales, C
    Persson, T
    Nordlander, S
    Comparison of carbon monoxide emissions and electricity consumption of modulating and non-modulating pellet heating systems2007In: International Journal of Energy Research, ISSN 0363-907X, Vol. 31, no 10, p. 915-930Article in journal (Refereed)
    Abstract [en]

    Emission and electricity consumption are important aspects of a pellet heating system. Low noxious emissions, particularly carbon monoxide, are a measure of a well-performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner, poor adjustment of the combustion air and insufficient maintenance. The carbon monoxide output, the thermal performance and the electricityconsumption for modulating and non-modulating operation mode have been investigated by simulations of four stoves/boilers as part of combined solar and pellet heating systems. The systems have been modelled with the simulation programme TRNSYS and simulated with the boundary conditions for space heating demand, hot water load and climate data as used in earlier research projects. The results from the simulations show that operating the pellet units with modulating combustion power reduces the number of starts and stops but does not necessarily reduce the carbonmonoxide output. Whether the carbon monoxide output can be reduced or not depends very strongly on the reduction of starts and stops and how much the carbon monoxide emissions increase with decreased combustion power, which are in turn dependent on the particular settings of eachpellet burner and how the heat is transferred to the building. However, for most systems the modulating operation mode has a positive impact oncarbon monoxide emissions. Considering the total auxiliary energy demand, including the electricity demand of the pellet units, the modulatingcombustion control is advantageous for systems 1 and 4 for the used boundary conditions. The study also shows that an appropriate sizing of the stove or boiler has a huge potential for energy saving and carbon monoxide emission reduction.

  • 16.
    Fiedler, Frank
    et al.
    Mälardalen University, Department of Public Technology.
    Nordlander, S
    Persson, T
    Bales, C
    Heat losses and thermal performance of combined solar and pellet heating systems2004In: Proceedings of EuroSun 2004 Conference, Freiburg, Germany, June 20-23 2004, 2004Conference paper (Other academic)
  • 17.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Constructed Filters and Detention Ponds for Metal Reduction in Storm Water2003Doctoral thesis, comprehensive summary (Other academic)
  • 18.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Constructed Filters for Metal Reduction in Storm Water2002In: Vatten, ISSN 0042-2886, no 3, p. 185-191Article in journal (Refereed)
    Abstract [en]

    Increased demand for storm water treatment has created development in filtration technologies for storm water. Manufacturers are using different filtration facilities and different filter materials. Therefore there is a need - from manufacturers, universities and government organisations - to put together current knowledge and to clarify important aspects concerning constructed filter systems. The first part of this paper reviews filtration facilities for storm water, filter substrates that have been tested for heavy metal reduction, and processes for contaminant transport through filter substrates. The second part of the paper presents an investigation of pine bark, used as a substrate in gully-pot filters for metal reduction in storm water.

  • 19.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Evaluation of the accumulation of sediment and heavy metals in a storm-water detention pond2002In: Water Science and Technology, ISSN 0273-1223, Vol. 45, no 7, p. 105-112Article in journal (Refereed)
    Abstract [en]

    Accumulation of sediments and water quality were investigated in a wet storm-water detention pond in central Sweden. The drainage area surrounding the pond was covered by a section of highway and secondary roads. Sediment samples were collected from the pond and heavy-metal concentrations analysed subsequently in the laboratory. The depth of accumulated sediments was measured at several points around the pond. The investigation showed that during the 18 months that had passed since the pond was constructed, a 5-8 cm layer of sediments had accumulated near the inlet, and a 1.5 cm layer near the outlet of the pond. Storm water passing through the detention pond showed an average reduction rate of 26-84% for total metal content, 67% for total N, 78% for total P and 92% for COD.

  • 20.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Filtration of Storm Eater for Metal Reduction using Natural Filter SubstratesManuscript (Other academic)
  • 21.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Metal Sorption to Natural Filter Substrates for Storm Water Treatment - Column Studies2002In: The Science of the Total Environment, ISSN 0048-9697, Vol. 298, no 1-3, p. 17-24Article in journal (Refereed)
    Abstract [en]

    Storm water generated from road runoff contains pollutants such as metals that are either dissolved in storm water or bound to particulates. Using detention ponds for the treatment of storm water from road runoff, where particles can settle, can reduce the level of particulate-bound metals in the water, while small particles and dissolved matter pass through the detention pond. Some of these metals can be removed by filtrating water through specially constructed filter systems. This investigation is a laboratory study where different filter substrates were tested in order to evaluate their efficiency in reducing heavy metals from water. Metal solutions were filtered through columns filled with various substrates consisting of combinations of calcium silicate rock (opoka), zeolite and peat. The metal-removal efficiency was correlated to hydraulic load, and for the metal species the reduction efficiency decreased with increased hydraulic load. Mixtures of opoka and zeolite were found to be superior to the other filter-substrate combinations tested with regard to both hydraulic aspects and removal efficiency. Peat mixed with the calcium silicate rock was not successful due to clogging which stopped the experiment. A manufactured product made from the calcium silicate rock (burned opoka) was found to be less useful because of its calcium oxide (CaO) content. Among the tested filter substrates, mixtures of opoka and zeolite seemed to be the most useful compositions with respect to reduction-efficiency and clogging aspects. The removal capacity of metals varied from 0.6 to 1.8 kg m(-3) depending on the metal and the filter substrate. 

  • 22.
    Färm, Carina
    Mälardalen University, Department of Public Technology.
    Removal of heavy metals in water by pine bark2003In: Vatten, ISSN 0042-2886, no 1Article in journal (Refereed)
    Abstract [sv]

    Metals that are dissolved in storm water can be removed by filtrating water through specially constructed filter systems. Pine bark is an interesting material for this purpose, but it needs further investigations regarding its removal efficiency of metals. This paper presents a laboratory study where pine bark was tested to evaluate its efficiency in reducing heavy metals in water. Metal solutions were prepared and used in batch tests with pine bark. The metal removal efficiency was correlated to different metal concentrations in the solution and different contact times between the pine bark and the metal solution. The results showed that a high metal removal was achieved after a short contact time. The metal removal was low for low metal concentrations (0.1 mg/L) and higher for metal concentrations from 1 to 10 mg/L. The removal capacity was found to be 2.6 g Cu, 1.3 g Zn and 3.8 g Pb per kg pine bark. An investigation of the influence of chloride in the metal solution showed that the metal removal decreased by 15-23 %, depending on the metal, in the presence of chloride. Sorption isotherms of Zn, Cu and Pb on pine are also presented in the paper.

  • 23.
    Färm, Carina
    et al.
    Mälardalen University, Department of Public Technology.
    Waara, Sylvia
    Removal of pollutants from storm water - using a detention pond and constructed filtersIn: Urban Water, ISSN 1462-0758Article in journal (Refereed)
  • 24.
    Gustafsson, Hanna
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Lokalt klimatarbete: En förstudie inför upprättandet av miljöstrategiska mål i Oskarshamns kommun2008Student thesis
    Abstract [en]

     

     

  • 25.
    Gustafsson, Linda
    Mälardalen University, Department of Public Technology.
    Undersökning av ljudnivåer på skolgårdar: - samt hur fasad och fönster dimensioneras med uppmätta värden2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is written on commission by WSP Acoustics. The report studies the outdoor sound levels on school yards in Stockholm. The questions given by the company to be answered was what are the actual sound levels at diffrent school yards with low traffic noise and how can you construct a facade element that reduces the sound level from the outside and meet the indoor requirements. Mesurements for four hours was done at eight schools set north and south of the city centre. The measurement period included one school break and one lunch break. The results of the measurements were that the equivalent and maximum sound level had small variations between the schools with some exceptions.The equivalent sound level was Leq 58-62 dB(A) and this shows a small variation. The school with the highest equivalent sound level of 67 dB was Maria skolan. This high level can be explained by more children on the school yard together at the same time etc. The maximum sound level was 85-89 dB(A), this if the level for Sofia skolan 82 dB was ignored. The level 85-89 dB(A) also shows a small variation. Calculations of the sound reduction index (R'w) for facade elements were also carried out for all the schools. The resulting sound reduction index for the whole facade was 34-41 dB. After assuming a 200 mm thick concrete facade for Sjöstadsskolan another calculation of building elements gives that the window have to reduce R'w 32 dB to meet the indoor requirements. In the future WSP Acoustics will use this report to choose building elements such as windows when building or rebuilding schools. It can also be used if any of the eight schools in this report needs a window changed to improve the acoustics.

  • 26.
    Gustafsson, Roger
    Mälardalen University, Department of Public Technology.
    Miljöledning för underhållsteknik: Vilken miljökompetens behöver underhållspersonal?2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose with this article is to give examples how to remain and in a long run develop a higher interest in maintenance activities and knowledge. First reason is the changed age-distribution with more number of older employees among maintenance personnel staff and second reason is demand for education due the increasing demand in environmental responsibility.

    In spite of there is a lot of knowledge of maintenance in national organizations of interests it will not be used in a sufficient extent in many companies. This knowledge is an important base to use to re-built the missing or loosed skills in companies. The national organization UTEK is involved in European projects to validate knowledge of maintenance. Lost of or bad maintenance activities will always affect on the environment.

    Establish a network between companies is a good way to exchange information in their common business areas. If the existing maintenance department in companies have difficulties to manifest itself, an alternative organization as a personnel co-operative organization can be a solution. That will be lead to better productivity and higher engagement in the personnel. To evaluate the maintenance skills for personnel to a good basic level will in most case lead that they further will search for more information and cause demand for increased efforts of education from educational institutions.

  • 27.
    Hamrin, Åsa
    Mälardalen University, Department of Public Technology.
    Marin undersökning av utvalda havsstränder inom Härnösands kommun: En studie av bottenfauna2008Independent thesis Basic level (degree of Bachelor), 20 points / 30 hpStudent thesis
    Abstract [sv]

    Detta examensarbete skrivs på uppdrag av Härnösand kommun, som vill ha ett underlag för vart kommunen kan exploatera sin mark ytterligare. Härnösands kommun ligger i södra Ångermanland och här utgör Bottenhavet kommungräns åt öster.

    En bottenfaunainventering har utförts på 25 lokaler efter kommunens kust, metoden för inventeringen har varit SS-EN 28565 ”Vattenundersökningar - Utformning och användning av kvantitativ provtagningsutrustning för bottenfauna på grunda hårdbottnar i sötvatten” (ISO 8265:1988). De infångade djuren har artbestämts, räknats och jämförts mot AAB index och Shannons diversitets index. Resultatet har visat att somliga lokaler har både ett högt art- och individantal medan andra lokaler, både har ont om individer och arter. Förklaringar till detta kan delvis bero på att många lokaler har legat väldigt nära utlopp och i dessa prover har både limniska och marina djur funnits. En annan förklaring till detta kan vara att somliga lokaler är väldigt karga medan andra är omgivna av mycket växtlighet och därmed mer näring. De olika indexen har visat väldigt olika värden för miljökvalitén, något som eventuellt kan förklaras att AAB index modifierades för att kunna användas till den valda provtagningsmetoden

  • 28.
    Hyytiä, Nanna
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Fuktsäkert byggande: Sjönära bostäder i Östra Hamnen i Västerås2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    Housing construction very close to the lake Mälaren has become very popular today. One potential problem with these houses is the influence of the sea climate. Unprotected buildings are affected by strong winds and precipitation. So for that reason, it is very important to make an accurate climate investigation and use it for decision-making during the planning of the new settlement.

    It is very important with a good moisture protection regarding pelting rain, that is the combination of wind and rain. This is more important for buildings close to a lake, as this location normally means a higher exposure to wind. The location of the main bodies of the houses has an effect on the wind force between the houses. Some house parts are affected more than other, for instance curtain walls, bays, balconies and so on. These are problematic because of water and moisture that are moving in into joints and cavities in connections.

    Bigger efforts than climate investigations are needed to get rid of the moisture problem.

    The different actors that are involved in the construction project need to cooperate and focus on potential moisture problems during the complete construction process, not only during the production phase. It is also important that the construction workers have the knowledge on how to construct buildings that are moisture safe in practice.

    According to investigations made, it appears that many of the moisture damages in buildings originate from the production phase because of incorrect construction components that are moisture-sensitive. But approximately 50% of the moisture problems derive from the planning process. The reasons are mainly lack of easily available tools, (for instance descriptions of moisture protection), insufficient knowledge, lack of time and lack of interest. These early mistakes results in later problems during the production phase. It is of great importance that the project members have good communication with the building contractors. They need to inform them on how to calculate dry times for different construction components and what type of inspections that shall be performed.

  • 29.
    Jacobson, Henrik
    Mälardalen University, Department of Public Technology.
    Ekologiska risker med handelsjöfarten på Mälaren2006Licentiate thesis, comprehensive summary (Other scientific)
  • 30.
    Jacobson, Henrik
    Mälardalen University, Department of Public Technology.
    Risk modeling; Definitions and methods of risk modeling in relation to shipping in Lake Mälaren2003In: Proceeding from 44th Scandinavian Conference on simulation and modeling, 2003Conference paper (Other (popular scientific, debate etc.))
  • 31.
    Jacobson, Henrik
    et al.
    Mälardalen University, Department of Public Technology.
    Forsberg, Åke
    Mälardalen University, Department of Public Technology.
    Odelström, Tommy
    Mälardalen University, Department of Public Technology.
    Dagvattenkvaliteten i anslutning till Hamnområdet i Västerås2006In: Vatten: Tidskrift för vattenvård, ISSN 0042-2886, Vol. 62, no 2, p. 149-159Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Dagvattenkvaliteten i hamnområden är ofta svår att definiera på grund av att hamnen ofta ligger inom industriområden med flera angränsande verksamheter och aktörer sammankopplade i samma avlopp och dagvattensystemet. Eftersom hamnen ligger närmast recipienten påverkas mätresultatet i hamnens provtagningspunkt av samtliga i avlopps- och dagvattensystemets tillförda föroreningar, vilket utgör svårigheter att få en tydlig bild av enbart hamnverksamhetens miljöpåverkan av vattnet. Bedömningsgrunder för vattenkvalitet i dagvatten och avloppsvatten är svårdefinierbara. De bedömningsgrunder som finns bygger på ett statistiskt material som utgår från olika provtagningar gjord i dag- och avloppsvatten system runt om i Sverige.

    Däremot i naturvatten finns goda underlag till vattenkvalitetsbedömningar i form av gränsvärden och normer vilka är vedertagna i litteraturen.

    I Västerås har hamnbolaget under några års tid haft hela ansvaret för mätning av förorenat vattnet i områdets dagvattensystem. Detta gäller även de föroreningar som inte härstammar från hamnens egen verksamhet, utan även från den omkringliggande. Juridiskt sett strider detta mot de allmänna hänsynsreglerna om att förorenaren betalar som beskrivs i miljöbalken. Kostnaderna har lagts på en enskild aktör för ett helt avlopps och dagvattensystem, där flera aktörer bidrar till miljöbelastningen. Detta har skett med förevändningen att hamnen är enskilt största verksamhet som bidrar med de största utsläppen av föroreningar till vattnet, vilket denna studie visar vara det motsatta förhållandet.

  • 32.
    Jacobson, Henrik
    et al.
    Mälardalen University, Department of Public Technology.
    Forsberg, Åke
    Mälardalen University, Department of Public Technology.
    Odelström, Tommy
    Mälardalen University, Department of Public Technology.
    Karim, Adel
    Mälardalen University, Department of Public Technology.
    Pollutant control in an inland water harbour: -a case study of Västerås harbour2007Conference paper (Refereed)
    Abstract [en]

    Every average sized harbour use a lot of cranes, trucks and other vehicles for loading and reloading incoming and out going ships. These vehicles are usually run by different diesel distillates, which emit pollution to the atmosphere. According to legal permissions based upon both European and national legalisations, the emission factors have to be reported in to the municipal environmental protection authorities. This present study presents methods in calculating gas exhaust emissions from these vehicles which effect the surrounding environment both to the nearby water and to the regional atmosphere. The calculation model is based upon fuel consumption and future possibilities to decrease this consumption and trade out some of the worst polluting distillates to other more ecological fuel systems.

  • 33.
    Javed, F.
    et al.
    School of Science and Engineering, Lahore, Pakistan.
    Arshad, N.
    School of Science and Engineering, Lahore, Pakistan.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Vassileva, Iana
    Mälardalen University, Department of Public Technology.
    Dahlquist, Erik
    Mälardalen University, Department of Public Technology.
    Engineering optimization models at runtime for dynamically adaptive systems2010In: Proceedings of the IEEE International Conference on Engineering of Complex Computer Systems, ICECCS, 2010, p. 253-254Conference paper (Refereed)
    Abstract [en]

    Dynamically adaptive systems (DAS), such as smart grids, cloud computing applications, sensor networks and P2P networks tend to change their structure at runtime. Therefore, design-time modeling for such systems are sometimes not enough for self-management. To this end, we have developed a dynamic mathematical modeling framework for runtime modeling for DAS. In this paper, we describe how our system engineers a linear programming model for self-optimization by using a smart-grid application for power distribution as a case-study. At runtime whenever, an optimization is desired this modeling framework captures the state of the system, converts it into an appropriate linear programming model, plan the changes using mathematical manipulations and apply the changes to the actual system. Our initial simulation results show that this framework is able to capture accurate runtime models of large power systems and is able to adapt itself with the change in the size or structure of the system by constructing a succinct model which is faster and more efficient than a design time model.

  • 34.
    Johansson, Daniel
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Förebyggande Brounderhåll2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    Abstract

    The Swedish Road Administration in the region of Mälardalen has since 2004 worked to in¬crease the efficiency of the maintance of bridges based on limited functional requirements and time demanded action.

    The maintenance of the bridges is contracted in the county of Uppsala since 2004, and Örebro since 2007. The county of Nyköping and Västerås is contracted by the traditional system. The contractor will perform a regular maintenance on all bridges. The bridges are inspected by the contractor at least once every year.

    The contractor registers the result of the inspection in a database called BaTMan. BaTMan is a Bridge and Tunnel Management system and is a strictly web solution were the user logs in via the internet.

    The Swedish Road Administration also inspects the bridges to se that the demands on the bridges are followed.

    My work is to compare these different inspections and to see any development.

  • 35.
    Johansson Westholm, Lena
    et al.
    Mälardalen University, Department of Public Technology.
    Färm, Carina
    Treating polluted water flows with filter technique2004Report (Other academic)
  • 36.
    Johansson Westholm, Lena
    et al.
    Mälardalen University, Department of Public Technology.
    Veibäck, Frida
    Environmental impacts of landfill covering by use of industrial by-products2003In: Proceedings of Kalmar ECO-TECH'03, 2003Conference paper (Refereed)
  • 37.
    Karimpourian, B.
    et al.
    Mälardalen University, Department of Public Technology.
    Mahmoudi, J.
    Mälardalen University, Department of Public Technology. Outokumpu, Sweden.
    Some important considerations in heatsink design2004In: Proceedings of the 6th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Micro-Electronics and Micro-Systems - EuroSimE 2005, 2004, p. 406-413Conference paper (Refereed)
    Abstract [en]

    This work is the study of heatsinks in theoretical and technical aspects. The objective of this paper is to provide a more clear imagine of heatsinks function and technology for beginners, designers, and researcher in various features. This paper serves as a guide for them to compare novel heatsink technologies. Theoretical correlations and simple equations recommended to calculate the heat transfer rate include Nusselt number, heat transfer coefficient and associated variables for some types of heatsinks to a certain extent are involved. Common terms and phenomenon in the heatsinks are defined.

  • 38.
    Karimpourian, Bijan
    Mälardalen University, Department of Public Technology.
    cfd modelling and experimental study on the fluid flow and heat transfer in copper heat sink design2007Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Abstract

    This thesis is studying the heatsinks new designs for copper heatsinks which utilizes modelling and simulation by CFD, construction of prototypes and experimental works. Challenges and complications in manufacturing of copper heatsinks are expressed and finding the solutions to these hindrances involve in this work. Numerical efforts supported by fluent are made to promote investigation and approaching the goal in which serves the new opportunities for wider application of copper material in heat sinks.

    However the thermal conductivity of copper is about double as aluminium but still aluminium heatsinks are commonly used for heat dissipation in computers.

    Comparing of heat performance of two analogous heatsink of different materials, aluminium and copper, is conducted by numerical analysis in the CFD environment.

    In addition to larger surface area and airflow velocity another solution for enhancement of heat dissipation is suggested.

    Manufacturing solutions of copper heatsinks are proposed which will facilitate fabrication of more high performance copper heatsinks than the current heavy and expensive models.

    Our first copper heat sink model is designed exclusively based on the technical observations and analyses of numerical simulation of two identical copper and aluminium heatsinks by CFD and as well as manufacturability concerns.

    This heat sink is fabricated mechanically and is tested by a number of heat sources and high sensitive devices such as adhesive K type thermocouple, data acquisition 34970A in associated with HP Bench Link program.

    An extent experimental work on aluminium heatsinks, integrated with forced convection, is performed in order to measure their thermal capacities.

    Comparison of the heat performance of a typical aluminium heatsink, which was the best among the all aluminium heat sinks and proposed copper heatsink under identical experimental conditions, is performed.

    Also in some numerical efforts, optimizing and predicting of the thermal characterization of the proposed heatsink with inclined free fins is developed. The model is scaled up in the fluent environment to predict its application in the cooling of larger heat generated electronic devices.

    Impingement air-cooling mode of force-convection is adopted for heat dissipation from high power electronic devices in associated with the proposed inclined fin model.

    Components of airflow velocity in the hollow spaces of the heatsink are discussed. Pressure drop and other thermal variables are analyzed analytical and by CFD code.

    Another mechanical manufactured copper heat sink is investigated. A new design of the base and fins is optimized.

    A three-dimensional finite volume method is developed to determine the performance of the proposed heatsink.

    Thermal and hydraulic characterization of the heat sink under air-forced convection cooling condition is studied. The flow behavior around the fins and some other parts of the heat sink is analyzed by utilizing CFD code.

    The hydraulic parameters including velocity profiles, distribution of static pressure, dynamic pressure, boundary layer and fluid temperature between the fins and in the passageway at the middle of the heat sink are analyzed and presented schematically.

    Furthermore the thermal characteristic of the proposed heatsink is studied by contouring the three dimensional temperature distributions through the fins and temperature of the heat source by CFD code.

  • 39.
    Karlberg, Christian
    Mälardalen University, Department of Public Technology. Mälardalen University, School of Sustainable Development of Society and Technology.
    Energi- och bullerlösningar för fastigheter i tågtrafiken2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 40.
    Karlsson, C
    et al.
    Mälardalen University, Department of Public Technology.
    Dahlquist, Erik
    Mälardalen University, Department of Public Technology.
    Dotzauer, Erik
    Mälardalen University, Department of Public Technology.
    Data Reconciliation and Gross Error Detaction for Flue Gas Train in Heat and Power Plant, USAManuscript (Other academic)
  • 41.
    Karlsson, C
    et al.
    Mälardalen University, Department of Public Technology.
    Dotzauer, Erik
    Gross Error Isolation by Optimisation with Penalty FunctionIn: Computers and Chemical EngineeringArticle in journal (Refereed)
  • 42.
    Karlsson, Christer
    Mälardalen University, Department of Public Technology.
    Tools for Reconciliation of Measurement Data for Processes at Steady-State2004Licentiate thesis, comprehensive summary (Other scientific)
  • 43.
    Karlsson, Christer
    et al.
    Mälardalen University, Department of Public Technology.
    Arriagada, Jaime
    Genrup, Magnus
    Detection and interactive isolation of faults in steam turbines to support maintenance decisions2008In: Simulation (San Diego, Calif.), ISSN 1569-190X, E-ISSN 1878-1462, Vol. 16, no 10, p. 1689-1703Article in journal (Refereed)
    Abstract [en]

    The maintenance of steam turbines is expensive, particularly if dismantling is required. A concept for the provision Of Support for the maintenance engineer in determining steam turbine status in relation to the recommended maintenance interval is presented here. The concept embodies an artificial neural network which is conditioned to recognise patterns known to be related to faults. The faults Simulated are not known to be recognized on-line and the concept is in an early stage of development, An example of a Bayesian network structure containing expert knowledge is proposed to be used, in a dialogue with the operator, to isolate the root causes of a number Of fault types. The aim is to be well informed about the statue of the turbine in order to take earlier and better informed maintenance actions. The detection procedure has been validated in a Simulation environment.

  • 44.
    Karlsson, Christer
    et al.
    Mälardalen University, Department of Public Technology.
    Dahlquist, Erik
    Mälardalen University, Department of Public Technology.
    Process and sensor diagnostics: Data reconciliation for a flue gas channel2003Report (Other academic)
  • 45.
    Kjellgren, Per
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Hejde, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Temperaturdynamik i Västerås fjärrvärmenät2008Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis the dynamics of temperature and flow in the Västerås district heating system is simulated using a model developed in Dymola. The model is dynamic and takes the transit times in the network into consideration. Due to insufficient statistical material, no pressure calculations have been done. Only the dynamics of temperature and mass flow have been simulated.

    The district heating network has been split into 18 nodes, one production unit and the distribution pipes. Due to the lack of good measurements, especially from different places in the network, many simplifications have been made. Data gathered at the production unit have been used to form equations for things happening in the nodes. These simplifications means that the model is not suited for seeing what happens in the DH network and should only be used for seeing what happens at the production unit. However, if more data were to be gathered at more places around the network, the equations could be rewritten thus improving the model substantially.

  • 46.
    Kumm, M
    et al.
    Mälardalen University, Department of Public Technology.
    Nyman, H
    Dahlquist, E
    Lundin, K
    The impact from outside wind on air movments in a telecom tunnel2005Manuscript (preprint) (Other academic)
  • 47.
    Kumm, Mia
    Mälardalen University, Department of Public Technology.
    Smoke control in tunnels: ventilation using mobile fans2005Licentiate thesis, comprehensive summary (Other scientific)
  • 48.
    Kumm, Mia
    et al.
    Mälardalen University, Department of Public Technology.
    Bergqvist, Anders
    Karlstad universitet.
    Tunneltäckning för effektivare brandventilation2005Patent (Other (popular science, discussion, etc.))
  • 49.
    Kumm, Mia
    et al.
    Mälardalen University, Department of Public Technology.
    Ingason, Haukur
    Can combinations of small fans be used for smoke evacuation in tunnels?2004Conference paper (Refereed)
    Abstract [en]

    This paper presents an overview of recent tests performed in the Masthamn and Stadsgard tunnels in Sweden. The aim of the tests was to investigate if combinations of smaller fans could be used for smoke control in tunnels. The systems possibilities and limitations are discussed and improving measures evaluated. The tests show that combinations of ordinary PPV fans can be used in moderate length single track rail tunnels if a tunnel cover to avoid short circuit over the fans is used. In shorter tunnels or with no counteracting wind the fans can be used without the cover.

  • 50.
    Kumm, Mia
    et al.
    Mälardalen University, Department of Public Technology.
    Ingason, Haukur
    Kan mobila fläktar användas för brandgasevakuering i tunnlar?2005In: VVS-tidningen Energi & Miljö, no 5, p. 56-58Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Då behovet att minska transportavstånd och att utnyttja mark till bebyggelse i stadsmiljö hela tiden ökar byggs idag fler och fler tunnlar och överbyggda anläggningar. Tunnlar har också en lång livslängd och används ofta under ett hundratal år. Detta innebär att det idag finns en mängd tunnlar som ännu används, men är byggda efter den standard som var aktuell vid tiden för byggnationen. Fasta ventilationssystem är inte heller en självklarhet i alla nybyggda tunnlar.

    Längre vägtunnlar har oftast fasta ventilationssystem inbyggda eftersom de avgaser som bilarna släpper ut också i normalfallet behöver ventileras bort. Sådana ventilationssystem kan också användas för att styra brandgaserna – brandröken - i händelse av en brand. Spårtunnlar, kortare vägtunnlar och distributionstunnlar för kablar eller rör saknar ofta fasta system för ventilation. Spårtunnlarna ventileras genom kolvverkan när tågen kör igenom tunneln och trycker luften framför sig, medan distributionstunnlarna ofta inte behöver ventileras eftersom människor normalt inte befinner sig i tunneln.

123 1 - 50 of 109
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf