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  • 301.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Challenges for decision makers when feed in tariffs or net metering schemes change to incentives dependent of a high share of self-consumed electricity2017In: 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC), IEEE conference proceedings, 2017, p. 2025-2030Conference paper (Refereed)
    Abstract [en]

    When there are differences in economic value of self-consumed and exported electricity, profitable PV installations are dependent on accurate predictions of self-consumed electricity. In this study, minute-based data of PV production and electricity use were logged in a single-family house in Sweden. It is shown that when self-consumed electricity is measured, a low time resolution and different electric meter configurations can result in 60% lower registered self-consumed electricity than predicted. When feed-in tariffs or net metering schemes change to incentives dependent on the fraction of self-consumed electricity, the market and electric meter infrastructure must be prepared to avoid market disturbances.

  • 302.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Gävle Energi, Gävle, Sweden.
    Effects of different time resolution when self-consumed and produced excess electricity is predicted in a single family house: case study in cold climate, Sweden2016Conference paper (Refereed)
  • 303.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energy efficiency measures in the built environment - some aspects to consider in Sweden2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The traditional energy system as we know it today will change in the future. There is a worldwide concern about the global warming situation and there are different actions implemented to limit the consequences from, mainly, the use of fossil fuels.

    In this thesis, multi-unit apartment buildings have been simulated according to how the global CO2 emissions change when different energy efficiency measures are implemented. The simulated buildings have also been used to investigate how the calculated energy efficiency of a building according to Swedish building regulations varies depending on which technology for heating is used in the building and if the building has a solar PV installation or solar thermal system. When the energy efficiency of a building is calculated accord-ing to Swedish building regulations, this thesis shows that heat pumps are a favored technology compared to district heating. Another result is that electric-ity use/production within the investigated district heating system is the most important factor to consider when minimizing global CO2 emissions.

    This thesis also investigates how the configuration of electric meters owned by the distribution system operator affects the monitored amount of self-consumed and produced excess electricity. Finally, four local low-voltage distri-bution networks were simulated when a future charging scenario of electric vehicles was implemented.

    If a single-family house installs a solar PV installation, this thesis reveals that the configuration of the electric meter is important for the monitored amount of self-consumed electricity. This thesis also shows that the investigated low-voltage distribution networks can handle future power demand from electric vehicles and a high share of solar PV installations, but rural low-volt-age distribution networks will need to be reinforced or rebuilt to manage the investigated future scenarios.

  • 304.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Evaluation of energy conserving measures in buildings connected to a district heating system: case studies in Gävle, Sweden2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    When different energy conserving measures are implemented for reducing energy use in buildings and the buildings are connected to district heating systems, it is important that an overall system analysis is made which takes into account the effects of total change of energy use due to the energy conserving measures.

    The method applied in this thesis uses hourly production data for the different production units in the district heating system in Gävle, Sweden. The merit order of the different production units is dependent on the electricity spot market price. To calculate the merit order, hourly data for the electricity price is used. The marginal production unit can then be determined for each hour of the investigated year.

    This thesis analyzes five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to installation of an exhaust air heat pump. This thesis also analyzes how the configuration of the electric meter affects the measured amount of self-consumed and produced excess electricity for a single-family house and for two multi-dwelling buildings of different sizes.

    The results show that the use of electricity is the most important objective to consider. The increased use of electricity for operation of the heat pump contributes to an increase of global CO2 emissions and the electricity produced by the solar photovoltaic installation contributes to a decrease of global CO2 emissions.

    The results also show that the configuration of the electric meter is important for the single-family house but negligible for the multi-dwelling buildings. The amount of produced excess electricity is high for all buildings, which means that the economic value of produced excess electricity is important for a profitable installation.

  • 305.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Impacts of different electric vehicle charging strategies on low voltage distribution networks, a case study for SwedenManuscript (preprint) (Other academic)
  • 306.
    Gustafsson, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Pyrolys för värmeproduktion: Biokol den primära biprodukten2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Pyrolys innebär att exempelvis biobränsle hettas upp i syrefattig miljö för att bilda pyrolysgas och kol. Pyrolysgasen kan brännas för att producera värme med låga utsläpp och kolet har en mängd användningsområden; jordförbättringsmedel, fodertillskott, filtermaterial, kolfastläggning, energibärare, ståltillverkning m.m. Om krav på bränsle och användningsområde för kolet uppfylls kan kolet certifieras som biokol. Syftet med den här rapporten är att utreda om pyrolystekniken är ett hållbart, tekniskt och ekonomiskt alternativ till pellets- och flisförbränning för värmeproduktion. Målet är att förmedla pyrolysens tekniska och ekonomiska förutsättningar, såväl positiva som negativa. Rapporten är baserad på en kombination av litteraturstudier, djupintervjuer, besök vid anläggningar och referensgruppsamtal.

     

    Pyrolys har använts i tusentals år för att producera kol. I Amazonas upptäcktes landområden med en sammalagd yta större än Storbritannien i vilka jorden var kolsvart. Denna svarta jord, terra preta, är berikad med kol och har därmed blivit mycket bördigare än omgivande, ursprunglig jord. I Sverige framställdes kol för att tillgodose metallindustrin med bland annat produktionsmaterial och bränsle. Till skillnad från pellets- och flisförbränning kan pyrolystekniken använda en stor mängd olika bränslen så länge de uppfyller krav på energidensitet och fukthalt. Marknaden för biokol växer i bl.a. Tyskland men är ännu liten i Sverige. De leverantörer av pyrolysanläggningar som besökts i denna rapport, Pyreg och Carbon Terra, gör anläggningar med syfte att producera biokol. Pyreg har utvecklat en process med skruvreaktor och integrerad pyrolysgasbrännare för att t.o.m. kunna använda avloppsslam som bränsle. Carbon Terras process är enkel och robust med fokus att producera mycket kol.

     

    Pyrolysteknikens styrkor är flexibiliteten att välja olika typer av bränslen, låga utsläpp, liten negativ miljöpåverkan och kolets olika användningsområden. Ser man till svagheterna är de marknadsrelaterade; outvecklad svensk marknad och okunskap om kolets användningsområden. Dessutom gör pyrolysanläggningarnas statiska effektuttag att de är mindre flexibla än pellets- och flispannor. I en tid då klimatförändringarna letar akuta lösningar medför kolfastläggning och biokol som jordförbättringsmedel stora möjligheter tillsammans med omvandling av pyrolysgas till fordonsbränsle. Dock är den befintliga pellets- och flisförbränningen väletablerad som uppvärmningsteknik, vilket kan utgöra ett hot mot pyrolysteknikens intåg på marknaden. Avsaknaden av regelverk pga. kompetensbrist kan också försvåra för etablering av pyrolysanläggningar.

     

    Slutsatsen i denna rapport är att pyrolystekniken är ett bra alternativ till konventionell pellets- och flisförbränning om man kan hantera att värmeproduktinen är statisk och att man beaktar kolets värde. Värmeproduktion från pyrolysgas ger lägre utsläpp av bland annat CO, NOx och stoftpartiklar än pellets- och flisförbränning och om kolet används för kolfastläggning är möjligheten till globala klimateffekter betydande. Det som starkast påverkar den ekonomiska kalkylen är kostnaden för bränslet och intäkten på kolet. För att gardera sig mot den outvecklade biokolmarkanden i Sverige har kalkylerna i denna rapport baserats på försäljning av biokol som jordförbättringsmedel, vilket ger låga intäkter jämfört med andra användningsområden. Styrkan i att valet av bränsle är flexibelt gör det möjligt att ha en bränslekostnad på noll om materialet annars ses som avfall. Marknaden för kol i Sverige är outvecklad vilket kräver ett aktivt arbete från de som ger sig in branschen, men om utvecklingen följer den i Tyskland ser de ekonomiska förutsättningarna starka ut.

  • 307.
    Gustafsson, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Gävle Energi AB, Gävle, Sweden.
    Karlsson, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Rönnelid, Mats
    Högskolan Dalarna.
    How the electric meter configuration affect the monitored amount of self-consumed and produced excess electricity from PV systems: case study in Sweden2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 138, p. 60-68Article in journal (Refereed)
    Abstract [en]

    This study evaluates how the principal function of bi-directional electric meters affects the monitored amount of self-consumed and produced excess electricity for dwelling buildings connected to the grid by three phases. The electric meters momentarily record the sum of the phases or the phases individually and then summarize the recorded values to a suitable time period and is then collected by the grid owner. In Sweden, both electric meter configurations fulfill laws and regulations.

    The meter configuration affects the monitored distribution of self-consumed and produced excess electricity significantly for the investigated single-family house but is negligible for the investigated multi-dwelling buildings. The monitored self-consumed electricity produced by the PV installation for the single-family house varies between 24% and 55% depending on the configuration and how the inverter is installed for the investigated year. The difference in economic value for the produced electricity varies between 79.3 to 142 Euros.

    Due to the electric meter configuration, the profitability of PV systems will be different for identical single-family houses with identical conditions. This should be corrected for a well-functioning market. It is also important to decide how the configuration should be designed to ensure that different incentives and enablers results in desired effects.

  • 308.
    Gustafsson, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Gävle Energi AB, Gävle, Sweden .
    Rönnelid, Mats
    Energy Technology, Högskolan Dalarna, Falun, Sweden.
    Trygg, Louise
    Linköpings universitet.
    Karlsson, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    CO2 emission evaluation of energy conserving measures in buildings connected to a district heating system: case study of a multi-dwelling building in Sweden2016In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 111, p. 341-350Article in journal (Refereed)
    Abstract [en]

    When taking action to fulfill the directives from the European Union, energy conserving measures will be implemented in the building sector. If buildings are connected to district heating systems, a reduced heat demand will influence the electricity production if the reduced heat demand is covered by combined heat and power plants.

    This study analyze five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system in Gävle, Sweden. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to an installation of an exhaust air heat pump.

    The different energy conserving measures affect the district heating system in different ways. The results show that installing an exhaust air heat pump affects the use/production of electricity in the district heating system most and electricity conserving measures result in reduced use of electricity in the building, reduced use of electricity for production of heat in the district heating system and an increase of electricity production.

    The conclusion is that electricity use in the building is the most important factor to consider when energy conserving measures are introduced in buildings within the district heating system in Gävle.

  • 309.
    Gustafsson, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Thygesen, Richard
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Karlsson, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Ödlund, Louise
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Rev-Changes in Primary Energy Use and CO2 Emissions: An Impact Assessment for a Building with Focus on the Swedish Proposal for Nearly Zero Energy Buildings2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 7, article id 978Article in journal (Refereed)
    Abstract [en]

    In the European Union's Energy Performance of Buildings Directive, the energy efficiency goal for buildings is set in terms of primary energy use. In the proposal from the National Board of Housing, Building, and Planning, for nearly zero energy buildings in Sweden, the use of primary energy is expressed as a primary energy number calculated with given primary energy factors. In this article, a multi-dwelling building is simulated and the difference in the primary energy number is investigated when the building uses heat from district heating systems or from heat pumps, alone or combined with solar thermal or solar photovoltaic systems. It is also investigated how the global CO2 emissions are influenced by the different energy system combinations and with different fuels used. It is concluded that the calculated primary energy number is lower for heat pump systems, but the global CO2 emissions are lowest when district heating uses mostly biofuels and is combined with solar PV systems. The difference is up to 140 tonnes/year. If the aim with the Swedish building code is to decrease the global CO2 emissions then the ratio between the primary energy factors for electricity and heat should be larger than three and considerably higher than today.

  • 310.
    Gustavsson, Sofia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering. University of Gävle, Faculty of Engineering and Sustainable Development.
    Svärdsjöstugan och Corvus corones plats: Utveckling i centrum2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 311.
    Guven, Huseyin
    et al.
    Istanbul Technical University, Civil Engineering Faculty, Environmental Engineering Department, Ayazaga Campus, Maslak, Istanbul, Turkey.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Wang, Zhao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Ozturk, Izzet
    Istanbul Technical University, Civil Engineering Faculty, Environmental Engineering Department, Ayazaga Campus, Maslak, Istanbul, Turkey.
    Life cycle assessment of upgrading options of a preliminary wastewater treatment plant including food waste addition2018In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 145, p. 518-530, article id S0043-1354(18)30691-2Article in journal (Refereed)
    Abstract [en]

    Life cycle assessment (LCA) is a beneficial tool to evaluate the performance of wastewater treatment plants (WWTPs) and to compare different upgrading options. The main objective of this study is to investigate the environmental impact of upgrading options of a preliminary WWTP in Istanbul, Turkey. The preliminary plant currently consists of mechanical treatment units and various upgrading options including primary treatment and high-rate activated sludge system (HRAS) process as well as the addition of food waste to wastewater were compared. Results showed that the baseline scenario (S0) had worse performance than all future scenarios (S1-3) except for climate change. The scenario of adding food waste to wastewater (S3) has the best performance in climate change, terrestrial acidification, terrestrial ecotoxicity and fossil depletion. Increased addition of food waste was also tested in the sensitivity analysis, and major improvements were obtained especially in climate change and terrestrial ecotoxicity.

  • 312.
    Hadin, Åsa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Anaerobic digestion of horse manure: renewable energy and plant nutrients in a systems perspective2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In horse keeping horse manure is produced, which can be utilized as a fertilizer or considered a waste. Horse manure constitutes a resource in terms of both plant nutrients and energy. In addition energy policies and objectives aim at replacing fossil fuels with renewable energy sources. The interest to improve resource recovery of horse manure increases due various incentives for renewable vehicle fuels, legal requirements on management of manure, and environmental impact from current horse manure management.

    This thesis aims at describing horse manure management in a life cycle perspective. This is made by (1) identifying factors in horse keeping affect­ing the possibility to use horse manure as a biogas feedstock and to recycle plant nutrients, (2) analysing factors in anaerobic digestion with influence on methane potential and biofertilizer nutrient content and (3) comparing the environmental impact from different horse manure treatment methods. Literature reviews, systematic combining, and simulations have been used as research methods.

    The results show that horse keeping activities such as feeding, indoor keeping, outdoor keeping and manure storage affect the amount and charac­teristics of horse manure and thereby also the possibilities for anaerobic digestion horse manure. Transport affects the collected amount and spread­ing affects loss of nutrients and nutrient recycling. Simulation results in­dicate the highest methane yield and energy balance from paper bedding, while straw and peat gave a higher nutrient content of the biofertilizer. The highest methane yield was achieved with a low rate of bedding, which in the cases of woodchips and paper is also preferable for plant nutrient recycling. Still, results indicate the best energy balance from anaerobic digestion with a high ratio of bedding. The environmental impact assessment indicates a reduction in global warming potential for anaerobic digestion compared to incineration or composting.

  • 313.
    Hadin, Åsa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    From waste problem to renewable energy resource: exploring horse manure as feedstock for anaerobic digestion2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A sustainable energy system requires, according to energy policies, reduced emissions of greenhouse gases, increased ratio of renewable sources of energy and more efficient use of energy. Horse manure could be regarded as waste, but also as a resource for renewable energy and plant nutrients. This thesis explores the potential of horse manure as a renewable energy source, and its possibilities to support and contribute to energy and environmental objectives. To do this, data was collected from literature, simulations, study visits and interviews.

    A number of horse keeping activities were identified in the assessment of horse manure as a feedstock for energy and as a plant resource: feeding, indoor housing, outdoor keeping, manure storage, fertilizing and transport, all with effect on amount and content of horse manure. Results indicated that choice and amount of bedding are important for both energy performance and plant nutrient content in the biofertilizer. Operational conditions such as long hydraulic retention time and high temperature had less impact for horse manure as a biogas feedstock. Anaerobic digestion resulted in the lowest global warming potential compared to incineration and composting, while large-scale incineration reduced primary energy demand, acidification potential and eutrophication potential. In a subsequent simulation, anaerobic digestion had lower potential environmental impact than unmanaged composting, regarding all chosen environmental impact categories in the study. Experiences from energy companies suggest that horse manure can be used in small quantities in co-incineration, with suitable incineration technology, but odor was mentioned as a problem. Farm-scale incineration required continuous maintenance and monitoring and mixing with pellets. As a feedstock for anaerobic digestion horse manure was regarded as suitable for plug-flow processes while stirred processes experienced more technical problems leading to increased cost for plants. With adaption of horse manure to the energy recovery technology to be used, and adaption at energy conversion plants to homogenous materials, this not yet fully utilized bioenergy resource has potential to contribute with renewable energy to the energy system, and thereby also reduce environmental impact from horse manure treatment

  • 314.
    Hadin, Åsa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Horse manure as feedstock for anaerobic digestion2016In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 65, p. 506-518Article in journal (Refereed)
    Abstract [en]

    Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible.

  • 315.
    Hadin, Åsa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Hillman, Karl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    A review of potential critical factors in horse keeping for anaerobic digestion of horse manure2016In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 65, p. 432-442Article, review/survey (Refereed)
    Abstract [en]

    Keeping horses causes environmental impacts through the whole chain from feed production to manure. According to national statistics, the number of horses in Sweden is currently 360,000 and is continuing to increase. This result in increasing amounts of horse manure that has to be managed and treated, which is currently done using practices that cause local, regional, and global environmental impacts. However, horse manure and its content of nutrients and organic material could be a useful fertiliser for arable land and a substrate for renewable energy production as biogas. The aim of the paper is to identify and describe potentially critical factors in horse keeping determining the amount (total mass) and characteristics (nutrient content and biodegradability) of horse manure, and thus the potential for anaerobic digestion. A systematic combining approach is used as a structural framework for reviewed relevant literature. All factors identified are expressed as discrete choices available to the horse keeper. In all, 12 different factors were identified: type and amount of feed, type and amount of bedding, mucking out regime, residence time outdoors, storage type and residence time of manure in storage, spreading and soil conditions, and transport distance and type of vehicle fuel used. Managing horses in terms of these factors is of vital importance in reducing the direct environmental impacts from horse keeping and in making horse manure attractive as a substrate for anaerobic digestion. The results are also relevant to environmental systems analysis, where numerical calculations are employed and different biogas system set-ups are compared to current and other treatments. In such assessments, the relevance and importance of the critical factors identified here and corresponding conditions can be examined and the most promising system set-up can be devised.

  • 316.
    Hadin, Åsa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Jonsson, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Energi och växtnäring från hästgödsel: Förbehandling, rötning och biogödselavsättning2015Report (Other academic)
    Abstract [en]

    The number of horses in society is increasing and today, according to Swedish Board of Agriculture, there are approximately 360,000 horses in Sweden, where three-quarters are found in urban or near-urban environments. All these horses will, according to calcula­tions, give rise to a total amount of manure of up to 1.4 million tons per year. If this manure is digested efficiently, this corresponds to an annual biogas production of 641 GWh, which is almost half of all biogas produced in Sweden in 2010. Although there are some practical limitations on how much of the potential that can be exploited, there is nevertheless a significant potential for increased use of renewable energy. By collecting manure and digesting it, three environmental benefits can be achieved:

    1. Emissions from conventional management where the manure is piled and stored, or spontaneously composted, are avoided
    2. Anaerobic digestion of manure produces biogas that can be used to generate elec­tricity and heat and, after upgrading (purification and pressure increase), as vehicle fuel; thereby fossil fuel emissions are reduced
    3. The resulting digestate can be used in agriculture, thereby replacing chemical ferti­lizer which provides additional environmental benefits

    Despite all these possibilities there are some obstacles and gaps in knowledge. This report is a systematic review of the state of knowledge about horse manure management, pre­treatment methods, digestion methods of horse manure, as well as aspects of the prolifer­ation of bio-fertilizer from horse manure. This part is mainly qualitative descriptions while subsequent reports present indicative calculations of the environmental benefits of different ways to design the management.

    The conclusions are that there are many factors that point to extract energy from horse manure, e.g. there are significant amounts of manure relatively close to urban areas, the straw bedding materials provide a supplement in biogas production, there is plenty of land for spreading digestate, and an improved horse manure management is also a good water protection measure. Drawbacks are that the digestion of horse manure is relatively untested and it is difficult to assess how increased waste management costs affect the horse industry. Another conclusion is the general lack of knowledge of horse manure from an environmental perspective at a level required for reliable environmental assess­ments. Nevertheless we hope to be able to propose system solutions which to a greater extent than previously should prove to work technically and be economically feasible. If these systems are translated into practical reality, environmental gains can be made through reduced environmental impact, reduced eutrophication, increased biodiversity and reduced use of finite resources.

  • 317.
    Hadin, Åsa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Hillman, Karl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Prospects for Increased Energy Recovery from Horse Manure: A Case Study of Management Practices, Environmental Impact and Costs2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 12, article id 1935Article in journal (Refereed)
    Abstract [en]

    A transition to renewable energy sources and a circular economy has increased interest in renewable resources not usually considered as energy sources or plant nutrient resources. Horse manure exemplifies this, as it is sometimes recycled but not often used for energy purposes. The purpose of this study was to explore horse manure management in a Swedish municipality and prospects for energy recovery. The case study includes a survey of horse manure practices, environmental assessment of horse manure treatment in a biogas plant, including associated transport, compared to on-site unmanaged composting, and finally a simplified economic analysis. It was found that horse manure management was characterized by indoor collection of manure most of the year and storage on concrete slabs or in containers, followed by direct application on arable land. Softwood was predominantly used as bedding, and bedding accounted for a relatively small proportion (13%) of the total mix. Anaerobic digestion was indicated to reduce potential environmental impact in comparison to unmanaged composting, mainly due to biogas substituting use of fossil fuels. The relative environmental impact from transport of manure from horse facilities to anaerobic digestion plant was small. Results also indicate a relatively high cost for horse keepers to change from composting on site to anaerobic digestion in a centralized plant.

  • 318.
    Hadin, Åsa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Ryrholm, Nils
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Biology.
    Energy recovery from horse manure - exploring energy actors’ experiencesManuscript (preprint) (Other academic)
    Abstract [en]

    European Union and Swedish national energy policy and energy objectives state an increased interest in transition of energy systems to more efficient use of energy, as well as increased use of renewable sources of energy. Horse manure is a potential resource available for renewable energy. Horse manure is sometimes considered a waste problem, resulting in research of possible energy recovery processes, such as combustion and anaerobic digestion. In this study 13 energy actors’ experiences of horse manure were explored by means of interviews and e-mail. Five related to combustion of horse manure and eight related to anaerobic digestion. The aim was to make a compilation of their knowledge and from the results identify how horse manure could be made more attractive as an energy resource. The challenges the actors face are mainly connected with horse manure being a heterogeneous material, primarily due to its bedding content (straw, wood bedding, etc.), and occasionally to other types of added waste. These unpredictable variations in the substrate as well as impurities like sand make it more difficult for plants to have standard procedures for processing horse manure. The view that bedding material needs to be specifically straw pellets and that all impurities should be kept out of the collected horse manure for anaerobic treatment was also expressed. Horse manure as part of co-combustion processes was perceived as a fuel with capacity to contribute to plant economy as it gives revenue from gate fees and could reduce costs for its NOx reducing capacity. Another view was that grate furnaces could possibly be more suitable than fluidized beds as incineration technology. However, problems with odour made two plants end their combustion trials. In farm-scale incineration horse manure required a lot of monitoring and co-combustion with pellets in order to maintain an effective process. When compiling all available information this study has a number of suggestions for how horse manure should be treated already at the production stage in order to be a more versatile resource in energy recovery processes. The recommendation is to keep horse manure dry (transports and incineration), avoid initiation of composting processes (AD and incineration), sort the waste = no added other waste (AD), and depending on intended AD-treatment process, use a specific bedding type. Most of these issues may be solved by supplier’s involvement in the supply chains for resource recovery, i.e. closing natural cycles of plant nutrients and energy recovery.

  • 319.
    Haga, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Eco-label effects in the built environment: does labeling a light source environmentally friendly influence performance and judgement?2018In: SAGE Open, ISSN 2158-2440, E-ISSN 2158-2440, Vol. 8, no 2Article in journal (Refereed)
  • 320.
    Haga, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Morally “loaded” labels influence product perception and social judgement2018In: Article in journal (Other academic)
  • 321.
    Haga, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Psychological consequences of moral labelling in the built environment2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Climate change is strongly linked to human behavior and technologies, and many of the barriers to sustainable behavior are rather psychological than technological. More sustainable technologies and food products have been introduced to combat climate change, most often labeled with morally loaded labels such as “organic” or “environmentally friendly”. The purpose of this thesis was, first, to gain knowledge into the psychological consequences of the introduction of eco-friendly technologies in the built environment, specifically how labeling these products “eco-friendly” influences perception and performance; secondly, to identify underlying psychological mechanisms and limits of this eco-label effect. Study 1 showed that participants generally prefer the taste of consumables labeled eco-friendly compared to conventional labeled alternatives, but the study also found that the label-effect is limited to certain products and certain judgmental dimensions. Results in this study also showed that people believe that eco-labeled products have positive effects on mental abilities. In Study 2 and 3, the focus was to study the effects of eco-labeling in the built environment on performance in cognitively demanding tasks, such as color discrimination and proofreading. At this point, the eco-label effect had been shown across a wide range of products like food, water, and office technologies, and been generalized to a wide range of judgmental dimensions and behaviors (i.e. taste, nutrition health benefits, comfortableness, and mental performance). In Study 4, results showed that eco-labeling can have effects also on behavior that arguably have very little to do with the labeling itself, by showing that social perception of photographed persons can also depend on the labeling of desktop lamps. A consistent finding across the studies was also that individual differences in environmental concern modulated the magnitude of the effect. The magnitude was larger in people with higher concern for the environment.

  • 322.
    Haga, Andreas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Halin, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Holmgren, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Psychological restoration can depend on stimulus-source attribution: a challenge for the evolutionary account?2016In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 7, article id 1831Article in journal (Refereed)
    Abstract [en]

    Visiting or viewing nature environments can have restorative psychological effects, while exposure to the built environment typically has less positive effects. A classic view is that this difference in restorative potential of nature and built environments depends on differences in the intrinsic characteristics of the stimuli. In addition, an evolutionary account is often assumed whereby restoration is believed to be a hardwired response to nature’s stimulus-features. Here, we propose the novel hypothesis that the restorative effects of a stimulus do not entirely depend on the stimulus-features per se, but also on the meaning that people assign to the stimulus. Participants conducted cognitively demanding tests prior to and after a brief pause. During the pause, the participants were exposed to an ambiguous sound consisting of pink noise with white noise interspersed. Participants in the “nature sound-source condition” were told that the sound originated from a nature scene with a waterfall; participants in the “industrial sound-source condition” were told that the sound originated from an industrial environment with machinery; and participants in the “control condition” were told nothing about the sound origin. Self-reported mental exhaustion showed that participants in the nature sound-source condition were more psychologically restored after the pause than participants in the industrial sound-source condition. One potential interpretation of the results is that restoration from nature experiences depends on learned, positive associations with nature; not only on hardwired responses shaped by evolution.

  • 323.
    Haga, Andreas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Holmgren, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Hansla, André
    Göteborgs universitet.
    An eco-label effect in the built environment: Performance and comfort effects of labeling a light source environmentally friendly2015Conference paper (Refereed)
    Abstract [en]

    People tend to idealize eco-labeled products, but can eco-labeling have consequences for performance To address this question, 48 university students were asked to undertake a color discrimination task adjacent to a desktop lamp that was either labeled “environmentally friendly” or “conventional” (although they were identical). The light of the lamp labeled “environmentally friendly” was rated as more comfortable. Notably, task performance was also better when the lamp was labeled “environmentally friendly”. Individual differences in environmental concern, but not pro-environmental consumer behavior and social desirability indexes, were related to the magnitude of the eco-label effect on performance. Whilst some previous studies have shown similar placebo-like effects of eco-labels on subjective ratings, this is the first study to show an eco-label effect for artifacts in the built environment on performance, and the first study to relate this effect to environmental concern. Psychological mechanisms that may underpin the eco-label effects are discussed.

  • 324.
    Hagberg, Lisa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Onlinebokning med användarupplevelsen i fokus2018Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 325.
    Haghshenas, Samira
    et al.
    School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    Sajadi, Behrang
    School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Multi-Objective Optimization of Impinging Jet Ventilation Systems: Taguchi Based CFD Method2018In: Building Simulation, ISSN 1996-3599, E-ISSN 1996-8744, Vol. 11, no 6, p. 1207-1214Article in journal (Refereed)
    Abstract [en]

    This paper presents a Taguchi method-based approach that can optimize the operating performance of impinging jet ventilation (IJV) systems with limited computational fluid dynamics (CFD) simulation results. The Taguchi optimization calculation finds the best operating design for the weighted overall objective function as a presenter of the multi-objective function problem. The method is used to optimize the operating characteristics of an IJV system considering the factors of supply air temperature, level of the return air vent and percentage of the air exhausted through the ceiling to achieve an overall best performance of thermal comfort, indoor air quality (IAQ) and system energy performance as the objective functions. The study indicates the contribution percentage for each factor in each objective function. The level of the return air vent, the supply air temperature, and the percentage of air exhausted through the ceiling have a contribution of 35.8%, 28.5%, and 35.8% in the objective functions, respectively. Based on the results, the best performance of the IJV system happens when the inlet air temperature is 18 °C, the height of the return air vent is 2 m above the floor, and the percentage of air exhausted through the ceiling is 22.5%.

  • 326.
    Halin, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    A Shield against Distraction from Environmental Noise2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Working in noisy environments can be detrimental to cognitive performance. In order to perform well people have to find a way to attenuate distraction. This thesis aimed to study the balance between distractibility and task demands in the context of office-related tasks as a means by which to better understand how people in the work environment are influenced by environmental noise.

    In Report 1, 2 and 3 higher focal-task difficulty was achieved by manipulating the readability of the text that participants were asked to read (i.e. either displaying the text in hard-to-read font or by masking it with static visual noise). The results of Report 1 and Report 2 showed that background speech impaired performance on proofreading and memory for written stories respectively compared to silence, but only when the focaltask difficulty was low, not when it was high.

    In Report 3 it was shown that background speech, road traffic noise, and aircraft noise impaired performance on text memory compared to silence, but again, only when focal-task difficulty was low.

    In Report 4 it was tested whether higher cognitive load on the focal task would reduce peripheral processing of a to-be-ignored background story. The results of Report 4 showed that participants in the low-load condition recalled more of the information conveyed in the to-be-ignored background story compared to participants in the high-load condition. It was also investigated whether individual differences in working memory capacity (WMC) would influence participants’ memory for written stories (Report 2) and incidental memory of the to-background story (Report 4) differently depending on task demand.

    The results showed that individuals scoring high on the WMC-test were less distracted by background speech in the easy-to-read font condition (Report 2), and recalled less of the information in the to-be-ignored background story in the low-cognitive load condition (Report 4) compared to individuals that scored lower on the WMC-test. These relationships were not found in the hard-to-read font condition in Report 2, or in the high-cognitive load condition in Report 4. Taken together, these results indicate that higher focal-task difficulty can shield against the detrimental effect environmental noise on performance on office-related tasks. Moreover, it shows that higher focal-task difficulty can help individuals with low-WMC to reach a level of performance that is similar to that of high-capacity individuals.

  • 327.
    Halin, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Distracted While Reading? Changing to A Hard-to-read Font Shields against the Effects of Environmental Noise and Speech on Text Memory2016In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 7, article id 1196Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate the distractive effects of background speech, aircraft noise and road traffic noise on text memory and particularly to examine if displaying the texts in a hard-to-read font can shield against the detrimental effects of these types of background sounds. This issue was addressed in an experiment where 56 students read shorter texts about different classes of fictitious creatures (i.e., animals, fishes, birds, and dinosaurs) against a background of the aforementioned background sounds respectively and silence. For half of the participants the texts were displayed in an easy-to-read font (i.e., Times New Roman) and for the other half in a hard-to-read font (i.e., Haettenschweiler). The dependent measure was the proportion correct answers on the multiple-choice tests that followed each sound condition. Participants’ performance in the easy-to-read font condition was significantly impaired by all three background sound conditions compared to silence. In contrast, there were no effects of the three background sound conditions compared to silence in the hard-to-read font condition. These results suggest that an increase in task demand - by displaying the text in a hard-to-read font - shields against various types of distracting background sounds by promoting a more steadfast locus-of-attention and by reducing the processing of background sound. 

  • 328.
    Halin, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Higher task difficulty shields against the effects of road traffic noise and air traffic noise on recall for written text2016Conference paper (Refereed)
  • 329.
    Halin, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - applied psychology.
    Holmgren, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - applied psychology.
    Haga, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - applied psychology.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - applied psychology.
    The Effects of Sound on Proofreading: Can Task Engagement Shield from Distraction2013Conference paper (Other academic)
    Abstract [en]

    Performance on various cognitive tasks is impaired by task-irrelevant speech. The objective of this study was to manipulate the detrimental effects of task-irrelevant speech on a proofreading task, by increasing task engagement using an odd font (i.e. Haettenschweiler vs. Times). Texts were proofread in three different sound conditions (i.e. quiet, task-irrelevant speech and spectrally rotated speech). The participants searched for words (i.e. either content or function words) that were either misspelled or exchanged with contextually inappropriate words. Speech impaired detection of exchanged function words, but only when the text was written in Times, not when written in the odd font. Moreover, the participants missed fewer misspelled words in the speech condition, especially in Times, and they read more slowly in this sound condition. Taken together, these results indicate that proofreading behavior changes in the presence of task-irrelevant speech, to a more superficial/structural level of text processing (hence the improvement in detection of misspelled words), in comparison to the deeper/semantic level of text processing in the quiet condition (i.e., better detection of contextually inappropriate words). Greater task engagement (as indexed by the Haettenschweiler font), however, appears to protect the participant from the effect of sound on the ability to detect contextually inappropriate words.

  • 330.
    Halin, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. University of Gävle.
    Marsh, John E.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. School of Psychology, University of Central Lancashire, Preston, UK.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Central load reduces peripheral processing: evidence from incidental memory of background speech2015In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 56, no 6, p. 607-612Article in journal (Refereed)
    Abstract [en]

    Is there a trade-off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n-back task in one of two levels of central/cognitive load (i.e., 1-back or 2-back) in the presence of a to-be-ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n-back task was completed. Memory was poorer in the high central load (2-back) condition in comparison with the low central load (1-back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC)—with a superior ability for attentional engagement—remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing—as indexed by incidental memory of background speech—is constrained when task engagement is high.

  • 331.
    Halin, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Marsh, John
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. University of Central Lanchashire.
    Haga, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Holmgren, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. Linköping University.
    Effects of speech on proofreading: can task-engagement manipulations shield against distraction?2014In: Journal of experimental psychology. Applied, ISSN 1076-898X, E-ISSN 1939-2192, Vol. 20, no 1, p. 69-80Article in journal (Refereed)
    Abstract [en]

    This article reports 2 experiments that examine techniques to shield against the potentially disruptive effects of task-irrelevant background speech on proofreading. The participants searched for errors in texts that were either normal (i.e., written in Times New Roman font) or altered (i.e., presented either in Haettenschweiler font or in Times New Roman but masked by visual noise) in 2 sound conditions: a silent condition and a condition with background speech. Proofreading for semantic/contextual errors was impaired by speech, but only when the text was normal. This effect of speech was completely abolished when the text was written in an altered font (Experiment 1) or when it was masked by visual noise (Experiment 2). There was no functional difference between the 2 ways to alter the text with regard to the way the manipulations influenced the effects of background speech on proofreading. The results indicate that increased task demands, which lead to greater focal-task engagement, may shield against the distracting effects of background speech on proofreading. 

  • 332.
    Halin, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Marsh, John
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. Preston University.
    Hellman, Anna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Hellström, Ida
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. Swedish Institute for Disability Research, Linköping University, Linköping, Sweden .
    A shield against distraction2014In: Journal of Applied Research in Memory and Cognition, ISSN 2211-3681, E-ISSN 2211-369X, Vol. 3, no 1, p. 31-36Article in journal (Refereed)
    Abstract [en]

    In this paper, we apply the basic idea of a trade-off between the level of concentration and distractibility to test whether a manipulation of task difficulty can shield against distraction. Participants read, either in quiet or with a speech noise background, texts that were displayed either in an easy-to-read or a hard-to-read font. Background speech impaired prose recall, but only when the text was displayed in the easy-to-read font. Most importantly, recall was better in the background speech condition for hard-to-read than for easy-to-read texts. Moreover, individual differences in working memory capacity were related to the magnitude of disruption, but only in the easy-to-read condition. Making a task more difficult can sometimes facilitate selective attention in noisy work environments by promoting focal-task engagement. 

  • 333.
    Halin, Niklas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. University of Gävle.
    Marsh, John
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology. Linnaeus Centre HEAD, Swedish Institute for Disability Research, Linköping University, Linköping, Sweden.
    Higher Task Difficulty Shields Against Background Speech2015Conference paper (Refereed)
    Abstract [en]

    Performance on visual-verbal tasks is generally impaired by task-irrelevant background speech, which can have consequences for individuals who works in noisy environments (e.g., schools or offices). This study examined the role increased task difficulty plays in shielding against the effects of background speech. This issue was addressed across 4 experiments whereby the level of task difficulty on visual-verbal tasks was manipulated (e.g., by changing the font of a text to one that is harder to read). Experiments 1 to 3 qualified the general finding: that background speech impairs performance on visual-verbal tasks (proofreading and prose memory), but only when task difficulty was low, not when it was high. Moreover, experiment 4 demonstrates that higher task difficulty on the focal task (n-back) also reduces recall on a surprise memory test on the content of a to-be-ignored background story. These results suggest that an increase in task difficulty, which promotes greater task engagement, can shield against the detrimental effects of background speech and also constrain the processing of complex semantic information present in background speech. 

  • 334.
    Hallberg, Daniel
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Stojanovic, Bojan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Akander, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building engineering.
    Status, needs and possibilities for service life prediction and estimation of district heating distribution networks2012In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 8, no 1, p. 41-54Article, review/survey (Refereed)
    Abstract [en]

    An optimised and proactive maintenance strategy aims to maximise the economical profit, minimise environmental impacts and keep the risk of failure to a low level. Implementation of such strategy in the context of district heating requires efforts and abilities for predicting future performances and estimating service life of district heating components. A literature review on failures (damages and performance reductions) occurring on district heating pipes, reveals that failures in district heating pipes are mainly leaks due to corrosion or mechanical impacts and reduced thermal insulation performance: leaks being the more serious damage type. A feasible service life estimation method for this type of damage is the Factor Method. Since the application of this method within the context of DH pipes has not been found in other publications, this paper focuses on describing the method and discusses the possibilities on how to apply it in two specific cases with respect to leakage: service life estimation of repaired district heating pipe sections (i.e. maintenance of district heating network) and of district heating pipes in new or extended district heating networks. A particular attention is paid on which modifying factors to consider and how to quantify them.

  • 335.
    Hallberg, Daniel
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Tarandi, V.
    On the use of open bim and 4D visualisation in a predictive life cycle management system for construction works2011In: Electronic Journal of Information Technology in Construction, ISSN 1403-6835, Vol. 16, p. 445-466Article in journal (Refereed)
    Abstract [en]

    Construction works are in periodical need of performance upgrade such as maintenance, repair and rehabilitation (MR&R). Facility managers are responsible to fulfil this need during the whole life cycle of the construction works in a manner that maximises the economical profit, minimises the environmental impact and keeps the risk of failure at a low level. A prerequisite for efficient facility management (FM) is long-term planning of MR&R actions. This requires management of a large amount of information, a process that includes gathering, storing, processing and presentation of data. With the development of open Building Information Models (open BIM) and standardisation of Industry Foundation Classes (IFC) new possibilities of efficient management of FM information have emerged. Due to its parametric and object-oriented approach, the open BIM-concept rationalises the information management and makes it more cost effective. This paper discusses how open BIM, with the aid of IFC, and Product Life Cycle Support (PLCS) may facilitate the implementation of a predictive Life cycle Management System (LMS) and by that improve the feasibility for adopting long-term and dynamic maintenance strategy in the FM process. A case study on the use of a commercial BIM-based design tool as information repository and media to present life cycle information within the context of the LMS concept on a hospital building is also presented. The case study shows that the build-up of the information becomes simpler, more clear and efficient compared to a traditional database solution, as it is done with parametric objects. However, the basic BIM can not serve for all LMS functions. There is still need for development of a BIM integrated LMS solution that may support prediction of life cycle performance and maintenance needs. Such a solution needs to be communicative to any open BIM software and thus has to be built upon open standards for exchange of building information, e.g. the IFC standard, and life cycle oriented standards like PLCS. Additional focus is put on 4D simulation and visualisation. Simulation and visualisation of long-term performance of buildings is of crucial importance when improving the feasibility for adopting a long-term and dynamic maintenance strategy in the FM process. © 2011 The authors.

  • 336.
    Hallkvist, Jonas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Förundersökning av möjligheten till modifiering av kylvattenintag: Undersökning av möjligheten till modifierat kylvattenintag vid Forsmarks kärnkraftsanläggning2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Elproduktion är en viktig del i dagens samhälle och hur man producerar elen har blivit en viktig fråga som diskuteras flitigt i Sverige och i omvärlden. I Sverige har elanvändningen och elproduktionen varit i närmaste oförändrad sedan 90-talet. Elanvändningen i Sverige är ca 140 TWh per år och drygt 40 % av detta produceras av kärnkraften. Detta medför att kärnkraften är en viktig del av den Svenska elproduktionen. Kärnkrafts-bolagen som äger kärnkraftverken i Sverige letar alltid efter sätt för att förbättra säkerheten på sina anläggningar samt att genomföra verkningsgradsförbättringar som minskar bränsleanvändningen. Det här arbetet inriktar sig på att öka produktionsförmågan genom att genomföra en verkningsgradsförbättring. Rapporten använder sig av en kvantitativmetod och behandlar vilka förutsättningar samt lösningar det finns till att sänka kylvattentemperaturen vid kärnkraftsanläggningen i Forsmark. Arbetet begränsar sig till att endast ge en överblick för vilka lösningar som finns. Ingen av lösningarna undersökas på djupet med undantag på mammutpumpar. Forsmark kärnkraftsanläggning består utav tre stycken reaktorer och använder tillsammans ca 145 m3/s kylvatten för att kyla ner ångan i turbinkondensatorerna. Att sänka temperaturen på kylvattnet med en grad innebär en verkningsgradsförbättring på 0,444 % vilket är utrett i rapporten. En sådan förbättring innebär att Forsmarks reaktor 3 ökar sin nettoeffekt med 5,25 MW. Att sänka kylvattentemperaturen kan göras på många sätt och i denna rapport ansågs det vara relevant att undersöka lösningar som lyfter upp bottenvatten eller blandar om vattnet ifrån olika nivåer i havet. De lösningarna som undersöktes var mammutpumpar, luftridå en vägg längst ytan, utgrävning av kylvattenkanal, förlängning av existerande kanal, djupvattenintag och strömbildare på botten. Den lösning som ansågs vara den mest attraktiva lösningen var luftridå och det var på grund utav att dess fördelar var många och dess nackdelar inte var alltför stora. De slutsatser som görs i denna rapport kan användas i andra reaktorer runtom i världen som har liknande förutsättningar.

  • 337.
    Hamnqvist, Beatrice
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Industrial design.
    En undersökning av konceptet eventdesign2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka konceptet eventdesign samt hur man tar fram design till olika event. Utefter det hitta och ta fram hållpunkter till kommunikationen av eventdesign för företaget JustGo. Även viss undersökning om hållbarhet kring event. Studien börjar med att brottas med två problem, vad event och eventdesign är samt hur marknadsföringen kan förbättras för företaget JustGo. Men ju mer studien löper vidare kommer det upp förbättringsområden som JustGo kan utveckla för att bli ett bättre företag. Hela studien utgår ifrån företaget JustGo, samt teoretiska tillägg. Därför är designprocessen bunden till detta företag och kan därmed se annorlunda ut på ett annat.

    Metoden som använts i denna studie är fallstudie kring företaget JustGo. Inom fallstudien har fyra olika datakällor använts, deltagande observation, direkt observation, intervju, samt arkivmaterial.

    Resultaten av denna studie har lett till följande: En förståelse kring vad ett event är. Begrepp som eventmanager, eventdesigner och eventdekoratör och skillnaden mellan dessa har diskuterats fram. Där det argumenteras för att JustGo håller på med eventdekoration mer än eventdesign. En designprocess över hur designen till ett event tas fram har sammanställts i en illustration. Eventbranschens förhållningssätt till hållbarutveckling kommer fram och hur man skulle kunna se på det på ett annat sätt. De förbättringsområden som upptäcks under studiens gång diskuteras samt förslag på hur dessa kan utvecklas för att lyfta företaget och få dem att växa. För att sedan hitta punkter som, varför det är viktigt med design i ett event, att ett event ser bra ut, att JustGo kan leverera endast det kunden behöver, att de ser till både helhet och detalj. Dessa punkter skulle JustGo kunna använda vid kommunikation av eventdesign och deras företag.

  • 338.
    Hang, J.
    et al.
    University of Hong Kong.
    Li, Y. G.
    University of Hong Kong.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building science - installation technology.
    Buccoliere, Riccardo
    Universita di Lecce.
    Di Sibatino, Silvana
    University of Salento.
    The influence of building height variability on pollutant dispersion and pedestrian ventilation in idealized high-rise urban areas2012In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 56, p. 346-360Article in journal (Refereed)
    Abstract [en]

    Studies are still required to understand how rural/marine wind remove ground-level pollutants released uniformly in street networks of high-rise urban areas. The link between building height variability and pollutant removal process still remains unclear. Several idealized urban-like neighbourhoods made of 9-row and 18-row small-scale high-rise square arrays (building width B = street width W, building packing density λp = 0.25) were first numerically studied with a parallel approaching wind and neglecting thermal effects. Normalized pollutant transport rates and pedestrian purging flow rate were applied to quantify the contribution of pollutant removal by mean flow and turbulent diffusion and their net purging capacity.

    Results show that the prediction of isothermal turbulent flows agreed generally well with wind tunnel data. For 9-row arrays with building height variations (standard deviation of 0–57.1%) and the same average canopy height (H0 = 2.33W), pollutant removal mainly depends on mean flows. Larger standard deviations tend to induce better pedestrian ventilation. In comparison to small and large standard deviations, medium values of 14.3–42.9% may experience smaller purging capacity by horizontal mean flows but significantly enhance that by vertical mean flows. For arrays with uniform heights, lowering aspect ratios (H/W = 2.33 and 2.67–1.5) or increasing street lengths (9-row to 18-row) may enhance the contribution of removing pollutants by turbulent diffusions across canopy roofs which may be similarly important as that by mean flows. Although further investigations are still required, this paper clarifies the relationship between building layouts, height variability and removal potential of ground-level pollutants in high-rise urban-like geometries.

  • 339.
    Hang, Jian
    et al.
    University of Hong Kong and Guangzhou University.
    Li, Yuguo
    University of Hong Kong.
    Buccolieri, Riccardo
    University of Salento, Italy.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building science - installation technology.
    Di Sabatino, Silvana
    University of Salento, Italy.
    On the contribution of mean flow and turbulence to city breathability: the case of long streets with tall buildings2012In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 416, p. 362-373Article in journal (Refereed)
    Abstract [en]

    This paper analyses the contribution of mean flow and turbulence to city breathability within urban canopy layers under the hypothesis that winds from rural/marine areas are sources of clean air (inhale effect) and main contributors to local-scale pollutant dilution (exhale effect). Using Computational Fluid Dynamics (CFD) simulations, several idealized long streets flanked by tall buildings are investigated for wind flow parallel to the street axis. Aspect ratios (building height/street width) ranging from 2 to 4 and street lengths ranging from neighborhood scales (~. 1. km in full scale) to city scales (~. 10. km in full scale) are analyzed. To assess the inhale effect, the age of air concept is applied to quantify the time taken by a parcel of rural/marine air to reach a reference location within the urban canopy layer. To simulate the exhale effect, removal of pollutants released from a ground level source is considered. Numerical results agree with wind tunnel observations showing that a bulk portion of rural/marine air enters the streets through windward entries, a smaller part of it leaves through street roofs and the remaining fraction blows through the street aiding pollutant dilution. Substantial differences between neighborhood-scale and city-scale configurations are found. For neighborhood-scale models, pollutant removal by rural/marine air is mainly associated to mean flow along the streets. Breathability improves in streets flanked by taller buildings since in this case more rural/marine air is captured inside canyons leading to stronger wind along the street. For city-scale models, pollutant removal due to turbulent fluctuations across street roofs competes with that due to mean flows along the street. Breathability improves in streets flanked by lower buildings in which less rural/marine air is driven out and pollutant removal by turbulent fluctuations is more effective. Based on these findings, suggestions for ventilation strategies for urban areas with tall buildings are provided.

  • 340.
    Hang, Jian
    et al.
    University of Hong Kong.
    Li, Yuguo
    University of Hong Kong.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building science - installation technology.
    Experimental and numerical studies of flows through and within high-rise building arrays and their link to ventilation strategy2011In: Journal of Wind Engineering and Industrial Aerodynamics, ISSN 0167-6105, E-ISSN 1872-8197, Vol. 99, no 10, p. 1036-1055Article in journal (Refereed)
  • 341.
    Hang, Jian
    et al.
    University of Hong Kong.
    Li, Yuguo
    University of Hong Kong.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building science - installation technology.
    Claesson, Leif
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, BMG Laboratory.
    Wind Conditions and Ventilation in high rise long Street Models2010In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 45, no 6, p. 1353-1365Article in journal (Refereed)
    Abstract [en]

    We regarded high-rise cities as obstacles and channels to wind. We first studied wind conditions and ventilations in idealized high-rise long street models experimentally and numerically with a constant street width (W = 30 mm), variable street heights (H = 2 W, 2.5W, 3W, 4W), variable street lengths (L = 47.4W, 79W. 333W, 667W) and a parallel approaching wind. The flow rates penetrating into windward entries are a little larger than the reference flow rate in the far upstream free flow through the same area with windward entries in all models. The stream-wise velocity decreases along the street as some air leaves upwardly across street roofs. Near the leeward entry, there is a downward flow which brings some air into the street and results in an accelerating process. In the neighborhood scale long streets (L = 47.4W and 79W), wind in taller streets is stronger and the ventilation is better than a lower one. For the city scale long streets (L = 333W and 667W), a constant flow region exists where the vertical velocity is zero and the stream-wise velocity remains constant. In such regions, turbulent fluctuations across the street roof are more important to air exchange than vertical mean flows. In a taller street, the process to establish the constant flow conditions is longer and the normalized balanced horizontal flow rate is smaller than those in a lower street. In the city scale long streets, the turbulence exchange rate can be 5-10 times greater than the mean flow rate. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

  • 342.
    Hang, Jian
    et al.
    Department of Mechanical Engineering, The University of Hong Kong, Hong Kong.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building science - installation technology.
    Li, Yugo
    Department of Mechanical Engineering, The University of Hong Kong, Hong Kong.
    Claesson, Leif
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, BMG Laboratory.
    Flow mechanisms and flow capacity in idealized long-street models2010In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 45, no 4, p. 1042-1053Article in journal (Refereed)
    Abstract [en]

    It is an open question whether a street network of a city has a certain flow capacity characterizing the flow that can pass through the street network. It s our hypothesis that at least the simple street network has a certain flow capacity. With the purpose of exploring this we studied numerically and experimentally the flow capacity in some idealized long-street models continuously lined with buildings and exposed to a parallel approaching wind. The height of all the models is the same (H = 69 mm). Three groups of models were studied: models with the same uniform street width (W = H) but different lengths (L = 21.7H, 43.5H, 72.5H); models with the same length (L = 43.5H) but different uniform width (W = H, 2H, 4H); and models with a change of width at half distance, L/2. In the last of the three cases, the width of the upstream half was always the same (W1 = H), but there was a wider (W2 = 1.25H, 1.5H, 2H) or narrower (W2 = 0.75H, 0.5H) downstream half. We normalized flow rates by a reference flow rate equal to the flow rate through an opening far upstream with the same area as the windward entry. The normalized flow rate through the windward entry was about 1.0 in all cases. For a sufficiently long-street models, a flow balance is established, creating a fully developed region with a constant horizontal flow (flow capacity) and zero vertical mean velocity. The street length does not affect the flow capacity but as expected the width of the street affects the flow capacity.

  • 343.
    Hang, Jian
    et al.
    Department of Atmospheric Sciences, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China.
    Wang, Qun
    Department of Atmospheric Sciences, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China .
    Chen, Xieyuan
    Department of Atmospheric Sciences, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China .
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Zhu, Wei
    Department of Atmospheric Sciences, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China .
    Buccolieri, Riccardo
    Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, University of Salento, Lecce, Italy.
    Di Sabatino, Silvana
    Department of Physics and Astronomy, University of Bologna, Bologna, Italy .
    City breathability in medium density urban-like geometries evaluated through the pollutant transport rate and the net escape velocity2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 94, no P1, p. 166-182, article id 4213Article in journal (Refereed)
    Abstract [en]

    This paper investigates pollutant removal at pedestrian level in urban canopy layer (UCL) models of medium packing density (λ<inf>p</inf> = λ<inf>f</inf> = 0.25) using computational fluid dynamics (CFD) simulations. Urban size, building height variations, wind direction and uniform wall heating are investigated. The standard and RNG k-ε turbulence models, validated against wind tunnel data, are used. The contribution of mean flows and turbulent diffusion in removing pollutants at pedestrian level is quantified by three indicators: the net escape velocity (NEV), the pollutant transport rate (PTR) across UCL boundaries and their contribution ratios (CR).Results show that under parallel approaching wind, after a wind-adjustment region, a fully-developed region develops. Longer urban models attain smaller NEV due to pollutant accumulation. Specifically, for street-scale models (~100 m), most pollutants are removed out across leeward street openings and the dilution by horizontal mean flows contributes mostly to NEV. For neighbourhood-scale models (~1 km), both horizontal mean flows and turbulent diffusion contribute more to NEV than vertical mean flows which instead produce significant pollutant re-entry across street roofs. In contrast to uniform height, building height variations increase the contribution of vertical mean flows, but only slightly influence NEV. Finally, flow conditions with parallel wind and uniform wall heating attain larger NEV than oblique wind and isothermal condition.The paper proves that by analysing the values of the three indicators it is possible to form maps of urban breathability according to prevailing wind conditions and known urban morphology that can be of easy use for planning purposes. 

  • 344.
    Hani, Sami
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Byggmetod, energianvändning, transport: vid jämförelse mellan Gävle Strands Etapp 2 och Maskinisten2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ABSTRACT                                                                                                                    

    Energy use during production of new buildings is an aspect of the hot environmental issues, yet both regulations and studies are absent. In this study a comparison is made on energy use at Strand Etapp 2 which is located at Sjaaregatan 19 and Maskinisten, located at Maskinistgatan 19, both in the city of Gävle. The objective of this study has been to determine which of the projects has the lowest energy use as well as emissions of green house gases due to transportation at the time of erecting the buildings. Maskinisten and Gävle Strand Etapp 2 differ in mainly two points: Gävle Strand Etapp 2 is prefabricated and has wooden frames and Maskinisten is site built and has concrete frame. The method has been to assume a functional unit for the projects in order to make an assessment of which of the projects that have minimum of energy use and emissions. In the calculations, energy use has been divided into three parts: the energy use of the factory (only for the prefabricated project), during transportation and at the building site. The emissions are calculated based on the distance of transportation and the choice of truck when transporting materials and modules. When comparing the two projects a distinct difference can be seen. The prefabricated house, Gävle Strand Etapp 2 requires a lot more energy during production, about 160 % more, compared to site built the Maskinisten. Although the energy use in transport, which is a large part of the total energy of Gävle Strand Stage 2, is disregarded in the comparison, the project still has an energy usage that is about 25 % higher than the value for Maskinisten. The emission that occurs during transport by diesel trucks used in the projects has been calculated in g/ton for each type of trucks and distance. When compared to a previous study, it seems that the amount of emissions is mainly due of the transport distance and not on whether it is transported as complete modules or as separated building materials. To further identify the advantages and disadvantages of the different methods of construction, several project managers from the two projects have been interviewed. The main advantage of prefabricated is considered the shortened construction period and a more efficient work - regardless of the season - on the other hand it is inflexible in comparison to the site-built. Looking only at energy use and emissions, which has been the main issue in this study; it is clear that Maskinisten is the project with the least environmental impact during the construction phase.

  • 345.
    Hansen, David
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Beskrivning av Kolmårdens stallgödsel: Hantering och biogaspotential2017Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Manure consist of feces, manure water, urine and stray material. Environmental and health harmful substances can also occur in manure. That is why it is important that the manure management is handled in a correct way to avoid the harmful substances that are likely to cause environmental and health problems. Natural substances are also a part of the manure and those are nitrogen and phosphorus and they could cause environmental effects as eutrophication and acidification with insufficient manure management. The environmental effects could affect ecosystems and the consequences could appear as that fishes are dying and poisonous algal blooms in watercourses. The bachelor thesis will illustrate the ecological and social benefits that Kolmården could achieve if they are replacing the current manure management which is manure spreading with anaerobic digestion. Besides that the current manure management will be described in more depth, aspects that could affect the biogas potential will be presented and the theoretical amount of biogas of the manure will be calculated. The first step that was completed in the thesis were to divide Kolmården’s animals into different animal groups that later could be used in the calculations of the biogas potential. Totally there are three animal groups in this thesis and they are: fowl, non-ruminant and omnivore and beast of prey. When dividing the animals was completed the search for literature began with the purpose to get up-to-date material that could be used in the thesis and to prepare the interview questions for the study visit at Kolmården. The amount of manure that emerge in the zoo is mucked from the animal’s pens and stables every day to be stored in small manure storage places. Those are emptied three times a week and freighted to a central storage place before the manure is spread on tenancy land or transferred to a farmer. The theoretical biogas potential from the manure at Kolmården can cover almost half of the energy need in a year. Aspects as food, straw material, nutrition content and antibiotics can affect the biogas yield.

  • 346.
    Hansen, Erik
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Norling, Susanne
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Åtgärdsförslag till Gävle Kommun för omhändertagandet av den förorenade marken på Brynäs 19:7, år 20152015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 2010, there was according to the County Administrative Board (2011) 80 000 sites suspected of being contaminated, and has been estimated to cost 45 billion to fix and take 40 years. The property Brynäs 19:7 in Gävle, where Cloetta and past operations have been conducted, is contaminated with mostly PAHs, PCBs, metals and petroleum hydrocarbons. The property will be a residential area but need to first undergo some type of remediation action. In order to choose the most sustainable remediation technology, a multi-criteria analysis (MCA) is a fitting tool to use. Within MCA is now SCORE, a specifically designed program for contaminated land, remediation and decision making. The purpose of this work is to develop and present proposals for actions to take to Gävle municipality, for disposal of contaminated soil at Brynäs 19:7. The goal is to determine the appropriate treatment methods and choose the best one by doing an MCA. In the methodology chapter it is described how the study came to be, the approach of the literature review, the MCA and important choices. The literature review consists of information on Brynäs 19: 7, including the pollution situation and a general description of the area. Then follows a literature review on the selected remediation methods; BioSan, Bioreactor, Daramend, Soil Washing, Thermal processing and Vacuum extraction. BioSan, Bioreactor and Daramend are biological methods, and soil washing a physical method. The remediation methods mainly contain a process description, type of pollution it can process and purification degree. The results have been compiled in a number of bar graphs, all of which are presented from a sustainability perspective, where all three sustainability domains have been included. The result shows that Vacuum extraction is the most viable option. The discussion includes the problems surrounding the filling material of the area, Off-site criteria and results. The conclusion is that the Vacuum extraction is the most sustainable of the alternatives to a clean-up of the property Brynäs 19: 7 and it is recommended that the method is used, alternatively Thermal processing. The methods could be combined to reduce their weaknesses and get an effective removal of the contaminants that require remediation. The limitations that existed have been mainly lack of time because of the extensive MCA. Lack of some information on Brynäs 19: 7 and about the various remediation techniques have to some extent been a limiting factor.

  • 347.
    Hansson, Tobias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Uris: Utvecklingen av en armbandsklocka som ökar barns tidsförståelse2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Projektets ursprungliga syfte var att ta fram en premium-armbandsklocka för barn som också underlättar förståelsen av klockan. Projektets syfte skiftade dock under designprocessens gång då jag genom intervjuer och enkäter märkte att målgruppens behov snarare var att utveckla tidsförståelse än att kunna utläsa exakta klockslag. I och med detta noterade jag även att barns och vuxnas armbandsklockor idag ser likadana ut sett till funktion, trots att behoven kring tid är helt skilda. Vidare har jag i projektet även använt mig av metoder som marknadsanalys, workshop, Minimum Viable Product, med mera.

    Mitt slutresultat blev en smartklocka för barn med funktioner som bidrar till att utveckla barnens tidsförståelse. En ökad tidsförståelse kommer, förutom att förenkla förståelsen av klockan, förhöja det egna ansvarstagandet kring rutiner och dagliga aktiviteter, vilket är en viktig del av livet. Vissa av klockans funktioner styrs via barnen själva direkt i klockan, medans vissa styrs av föräldrarna via den tillhörande mobilappen. 

  • 348.
    Hansson, Tomas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Alarm signals, can a change of siren speed capture human attention?2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An effective alarm system is a critical part of many different types of jobs. It is also important that the alarm signal can capture human attention and convey appropriate urgency. In the current study the effect of siren sounds with or without unexpected, deviant sounds represented by a change of speed (a temporal deviant) were tested to evaluate if such change could successfully capture attention. The results showed that distraction was more pronounced when the deviant within the sound was a change from fast to slow as compared with slow to fast. Therefore, an alarm signal using a temporal deviant – changing from fast to slow—can be effective in capturing human attention and might be factored into the design of alarm systems.

  • 349.
    Hansson, Tomas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Exploring the properties of alarm signals that makes them attention-capturing: The Role of interstimulus intervals2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Alarm signals such as sirens are crucial in alerting users of impending dangers. Therefore, it is important that the siren is designed so it can capture user's attention. In a previous study (Hansson, 2017) background alarm sirens composed of changing-state sounds with an embedded temporal deviant, produced greater disruption of serial short-term memory than a signal without a temporal deviant. However, to give rise to disruption the siren needed to change from fast to slow, since a change from slow to fast was impotent in its effect on task performance. This was further addressed in Hansson (2018) where it was shown that acoustic change appeared to be a necessary prerequisite for obtaining the fast-to-slow temporal deviant effect: When steady-state sounds were used fast-to-slow and or slow-to-fast temporal deviants were equally disruptive of serial recall. However, in order to create a steady-state siren, inter-stimulus intervals were incorporated into the siren to prevent the continuous uninterrupted presentation of a single tone. Since inter-stimulus intervals were not used in Hansson (2017) it could be the presence of these that eliminated the potency of the fast-to-slow over the slow-to-fast temporal deviation effect in Hansson (2018). Therefore, the current study was undertaken to investigate whether the embedding inter-stimulus intervals within a changing-state siren would restore the potency of the fast-to-slow temporal deviation over the slow-to-fast temporal deviation in capturing attention. The additional disruption for fast-to-slow temporal deviants over slow-to-fast temporal deviants (that did not produce disruption relative to control) returned in the current study when inter-stimulus intervals were included within the siren. The results support the notion that the additional disruption produced by fast-to-slow, over slow-to-fast temporal deviants depend on the changing-state properties of the siren. Implications of this result for the design and operation of sirens within ecologically valid settings are discussed.

  • 350.
    Hansson, Tomas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    When the Siren Sounds: In Search of Acoustic Properties that make an Alarm Signal Effective at Capturing Attention2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A functional and effective alarm signal is a critical component of alarm systems designed to alert workers of impending danger. In a previous study (Hansson, 2017) background alarm sirens composed of changing-state sounds with an embedded temporal deviant, produced greater disruption of serial short-term memory than a signal without a deviant. However, to give rise to disruption the siren needed to change from fast to slow, since a change from slow to fast was impotent in its effect on task performance. In the current study, whether acoustic change was a necessary prerequisite for obtaining the fast-to-slow deviant effect was explored. Thus, repeated tones—steady-state sequences—presented at slow or fast rates were used with or without a temporal deviant (change from slow-to-fast vs. change from fast-to-slow). In the context of the steady-state sequences, both slow-to-fast and fast-to-slow temporal deviants produced disruption relative to the fast and slow control sequences. This suggests that a changing-state sequence is required for the fast-to-slow temporal deviant effect to arise. However, an alternative explanation based upon inter-stimulus intervals is also entertained. Understanding the acoustic parameters of sound is necessary to develop alarms sirens that are better at capturing attention. The current study suggests that embedding temporal deviants within sirens can promote greater attentional capture, but that this may depend on the nature of the alarm signal (whether it is changing vs. steady-state) and the direction of the change of speed (slow-to-fast vs. fast-to-slow).

     

     

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  • asciidoc
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