lnu.sePublications
Change search
Refine search result
1234567 1 - 50 of 456
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aarthi, Aishwarya Devendran
    et al.
    LKAB, Sweden.
    Mainali, Brijesh
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Khatiwada, Dilip
    KTH Royal Institute of Technology, Sweden.
    Golzar, Farzin
    KTH Royal Institute of Technology, Sweden.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Implementation of GIS-AHP Framework for the Identification of Potential Landfill Sites in Bengaluru Metropolitan Region, India2023In: The 9th International Conference on Energy and Environment Research. ICEER 2022. / [ed] Caetano, N.S., Felgueiras, M.C., Springer, 2023Conference paper (Refereed)
    Abstract [en]

    Uncontrolled open dumping and burning of municipal solid waste (MSW) has resulted in soil, water, and air pollution in many urban cities in India. Landfills are the most common cost-effective solution for MSW management in many developing countries like India. However, the identification of suitable landfill sites always remains a challenging task as it involves the selection of several environmental criteria set by the local authorities. The objective of this study is to identify the most potential landfill sites proposed by the Government in Bengaluru Metropolitan Region, Karnataka state, India using Geographic Information System enabled Analytical Hierarchy Process based multi-criteria evaluation technique. Several criteria and constraints as recommended by the local authorities along with the proximity to the solid waste processing plants are used to identify the potential landfill sites in the study region. The study identified three highly suitable sites (Neraluru, Gudhatti, Madivala) for landfills which are not only environmentally sustainable but also economically attractive as they are closer to the solid waste processing plants minimizing the transportation cost involved in the disposal of solid waste from the source to the final disposal sites in the study region.

  • 2.
    Abou Ghadir, Mohammed
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Aghaei, Zahra
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Life Cycle Analysis and Life Cycle Cost Assessmentof a Single-family house Energy Renovation: Case study Växjö, Sweden2022Independent thesis Advanced level (degree of Master of Fine Arts (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Humans are increasingly influencing the climate and the temperature of the Earth by burning fossilfuels, destroying forests, and raising livestock. This adds massive amounts of greenhouse gases(GHG) to those already present in the atmosphere, amplifying the greenhouse effect andcontributing to global warming. The building sector accounts for a significant amount ofgreenhouse gas emissions. Decarbonizing the building industry can result in significant emissionreductions in the future years. Sweden's energy and climate goals have been updated, and some ofthem include reducing GHG emissions in the building sector, increasing energy efficiency, andmaking electricity production 100 percent renewable. In Sweden, energy renovations in singlefamily houses (SFHs) have the potential to reduce GHG emissions and improve energy efficiency,but the rate of energy renovations remains low because of financial, social, and behavioral barriers.This thesis aims to use LCA and LCC methodologies to assess energy renovations on SFH inVäxjö by combining various combinations of energy efficiency measures (EEMs) to reduce energyuse. The energy performance and eight different renovation scenarios using different EEMs havebeen evaluated for the selected single-family building. To evaluate building renovation measures,we developed a method based on life cycle assessment (LCA) and life cycle cost (LCC) thatincorporates building information modeling (BIM). Five different renovation measures werecombined in eight scenarios in this research, including different thicknesses of thermal insulationfor walls and roofs, triple-glazed windows, and doors with different U-values, air-source heatpumps, mechanical ventilation with heat recovery, and solar photovoltaic. The present cost valuesof renovation measures over 50 years for LCC calculation were calculated. The global warmingpotential (GWP) of each renovation measure was estimated over 50 years using One-click LCA.According to the findings of this thesis project, scenarios 1 and 8 had the lowest and highestreductions in primary energy number, respectively. Scenarios 5, 6, 7, and 8 are the most costeffective in comparison to other scenarios. All scenarios resulted in a reduction in GWP impactfrom an LCA perspective in which scenario 7 resulted in the highest reduction in GWP impact. 

    Download full text (pdf)
    fulltext
  • 3.
    Abou Zour, Sam
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Anaerobic Digestion of Food: Waste Characterization, Biomethane Potential, Power Generation and Digester Design: A Case Study in Zahle District, Lebanon.2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Due to the waste crisis in Lebanon and its impact on the social, environmental, and economic sectors, many municipalities like Zahle District and its Unions of Municipalities planned to apply the circular economy to tackle the mismanagement of solid waste. Theoretically, many studies have been conducted at Zahle landfill to integrate was-to-energy technologies and get benefit of the gas generated by anaerobic digestion of biodegradable waste such as food. However, several basic variables related to anaerobic digestion AD had not been taken into consideration such as variation in the organic composition, waste generation related to the population, and power generation efficiency. Therefore, based on the plans set by Law 80 on Integrated Solid Waste Management ISWM to achieve 35% recycling rates 2025-2035, and Intended Nationally Determined Contribution (INDC) with conditional target 30% of recycling by 2030, the aim of this thesis is to estimate the biomethane production and power generation achieved at different rates of food waste digestion between 2025 and 2035, to achieve 30 and 35% recycling of FW beside the composting.Thus, scenario A where 10 to 20% of FW is digested, by increasing 1% every year from 2025 t0 2035, and 15% for composting as constant, results show a biomethane yield of 604000 to 1725000m3 annually, with a power generation 2400 to 6800 MWh/years for 2025 and 2035 respectively by usage of 1MW CHP 41.25% electrical efficiency. The achievement of scenario A requires 5 to 9 150m3digesters.Scenario B where digestion rates are 25% by 2025 and 35% by 2035 requires 10 to 19 150m3digesters, where biomethane and power production have ranges of 1466500 to 3019000 m3 annually, and 5800 to 11900MWh/year, respectively.

    Download full text (pdf)
    fulltext
  • 4.
    Adolfsson, Beatrice
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Johansson Mess, Marja
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Driftoptimering av lakvatten­­rening: Jämförelse mellan tekniker för uppvärmning av nitrifikationsdammen på Häringetorp avfalls­anläggning2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Biologisk lakvattenrening, med hjälp av mikroorganismer, används på Häringetorp avfallsanläggning för att bland annat reducera mängden kväve i lakvattnet. För att möjliggöra en längre reningsperiod, eftersom mikro­organismernas tillväxt hämmas vid låga temperaturer, vill Tekniska förvaltningen på Växjö kommun studera möjligheten att värma upp nitrifikationsdammen på Häringetorp avfallsanläggning med hjälp av grön energi.

    Kvantifiering av effektbehov för förlängning av reningsperioden har gjorts utifrån en simuleringsmodell. Studie av tillförd effekt har gjorts under det första året med tillförd effekt. Jämförelse mellan de tekniska lösningarna solfångare, värmepump och biobränslepanna har gjorts gällande aspekterna driftsäkerhet, praktisk genomförbarhet, enkelhet och ekonomi. Utifrån diskussion ges rekommendation att installera en värmepump, vilken utnyttjar intern energi, för att levererar en effekt till nitrifikationsdammen på 100 kW under temperaturstyrda förhållanden. Denna tillförsel av effekt förväntas ge en förlängning av reningsperioden på fyra veckor.  

    Download full text (pdf)
    fulltext
  • 5.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Benzene conversion using a partial combustion approach in a packed bed reactor2022In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 239, no Part C, article id 122251Article in journal (Refereed)
    Abstract [en]

    This study investigates the partial combustion technique for tar conversion using a modified experimental set up comprising a packed bed reactor with bed-inside probe for air supply. Simulated producer gas (SPG) and benzene were selected as a real producer gas alternative and model tar component respectively. The benzene conversion was investigated under different experimental conditions such as reactor temperature (650–900 °C), packed bed height (0–12 cm), residence time (1.2–1.9 s), air fuel ratio (0.2 and 0.3) and SPG composition. The results showed insignificant effect of temperature over benzene conversion while air fuel ratio of 0.3 caused high benzene conversion than at 0.2. Absence of packed bed lead high benzene conversion of 90% to polyaromatic hydrocarbons (PAHs) compared to similar low PAHs free benzene conversion of 32% achieved at both packed heights. In SPG composition effect, H2 and CH4 had a substantial inverse effect on benzene conversion. An increase in H2 concentration from 12 to 24 vol% increased the benzene conversion from 26 to 45% while an increase in CH4 concentration from 7 to 14 vol% reduced the benzene conversion from 28 to 4%. However, other SPG components had insignificant impacts on benzene conversion.

  • 6.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Coke-free conversion of benzene at high temperatures2023In: Journal of the Energy Institute, ISSN 1743-9671, E-ISSN 1746-0220, Vol. 109, article id 101307Article in journal (Refereed)
    Abstract [en]

    This study investigates the conversion of benzene in a novel highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 °C. The influences of packed bed presence, reforming medium (steam and CO2), gas flow rate and benzene concentration on steady state benzene conversion are examined. In presence of packed bed, benzene conversions of 52, 75, and 84% were achieved with combined steam and CO2 reforming at 1000, 1050, and 1100 °C, respectively. Whereas, benzene conversion of 65% without the packed bed at 1000 °C experienced a continuous increase in differential upstream pressure (DUP) of high temperature (HT) filter at reactor downstream due to deposition of in situ generated coke. High concentrations of generated CO and H2 of 2.3 and 6 vol% with packed bed than 1.4 and 4.7 vol% without the packed respectively, were achieved. CO2 reforming achieved high benzene conversions of 68–98% than 42–80% achieved with stream reforming at packed bed reactor temperatures of 1000–1100 °C. The results indicated that presence of ɣ-Al2O3 packed bed with possible surface reactions directed the conversion of benzene to combustible gases instead of coke. Hence, ɣ-Al2O3 packed bed reactor could be a suitable choice for coke-free conversion of tar of gasifier producer gas.

    Download full text (pdf)
    fulltext
  • 7.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Investigation of different configurations of alumina packed bed reactor for coke free conversion of benzene2024In: Chemical engineering research & design, ISSN 0263-8762, E-ISSN 1744-3563, Vol. 201, p. 433-445Article in journal (Refereed)
    Abstract [en]

    Conversion of producer gas tar without coke generation is a great challenge. This study investigates conversion of tar model benzene using different configurations of highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 0C. The configurations comprised of different positions (relative to top (P1), center (P2) and bottom (P3) of reactor furnace), heights (5, 13 and 25 cm) and particles sizes (0.5, 3 and 5 mm) of alumina packed bed. Steam and CO2 were used as reforming media for tested benzene concentrations (0.4–1.8 vol%). The results showed benzene conversions of 48–91% with negligible steady thin coke generation using a packed bed (height: 25 cm, particles size: 3 mm) at P1. Whereas, relative high benzene conversions of 63–93 and 68–95% at P2 and P3 respectively with unsteady thick coke generation at benzene concentrations greater than 0.4 vol% increased differential upstream pressures (DUPs) of beds. Similar unsteady coke generation at benzene concentrations greater than 0.8 vol% and temperature of 1100 0C was observed with packed beds of heights of 5 and 13 cm, and particles size of 0.5 mm at P1. Generation of unsteady coke with condensed structure as evidenced by its characterization was attributable to increased benzene polymerization and reduced bed surface gasification reactions due to improperly installed packed bed. Developed kinetic model predicted well the generated coke. As conclusion, properly installed alumina packed bed pertaining to tar concentration and other experimental conditions may inhibit coke generation during tar conversion.

    Download full text (pdf)
    fulltext
  • 8.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Sultan Qaboos Univ, Oman.
    Vakilinejad, Ali
    Sultan Qaboos Univ, Oman;Univ Tehran, Iran.
    Aman, Zachary M.
    Univ Western Australia, Australia.
    Vakili-Nezhaad, G. Reza
    Sultan Qaboos Univ, Oman.
    Thermophysical Study of Binary Systems of tert-Amyl Methyl Ether with n-Hexane and m-Xylene2019In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 64, no 2, p. 459-470Article in journal (Refereed)
    Abstract [en]

    This work presents the experimentally determined density (rho), viscosity (eta), speed of sound (u), and surface tension (sigma) data for tert-amyl methyl ether (TAME) + n-hexane and TAME + m-xylene systems at several temperatures (298.15, 308.15, 318.15, 323.15, and 328.15 K). These experimentally determined thermophysical data are utilized to compute various excess/deviation parameters such as molar volume (V-E), isentropic compressibility (K-s(E)), speed of sound (u(E)), deviation in viscosity (Delta In eta), isobaric thermal expansion coefficient (alpha(E)(P)), and surface tension (sigma(E)). The inspection of parameters response may interpret the existing specific molecular interactions as well as the mixing behavior of solutions. The critical analysis of observed parametric behavior have unveiled the strong and weak molecular interactions in TAME with m-xylene and TAME with n-hexane systems, respectively.

  • 9.
    Ahmed, Samar
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Carbon neutral scenarios for Växjö municipality2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sweden’s municipalities are leading the green energy transition, in this study, a techno-economic evaluation was done for a number of carbon neutral scenarios for Växjö municipality’s future energy system, situated within Sweden’s projected energy demand development in 2030 and 2050. The municipality’s partially decentralized energy system relies heavily on interconnected electricity supply from the national grid, and fuels imports from other parts of Sweden. It was a matter of question: in which ways will future demand changes induce supply changes, and whether a future carbon neutral energy system will be less costly in a sustained-electricity supply condition? To answer this, a balanced energy reference system for the municipality was created from an actual energy balance, using an hour-by-hour dynamic energy analysis tool EnergyPlan. Afterward, a future energy demand projection for Växjö was stemmed from the Swedish Energy Agency (SEA) sustainable future scenarios for Sweden, based on an average inhabitant energy demand. Modelling results for Växjö carbon neutral scenarios showed that Växjö energy system will be sufficient to supply future heat demand but not electricity demand, nor transport and industrial fuels. While in the short-term being carbon neutral is more economically attainable without changes in electricity supply technologies, a projected electricity price and consumption increase, change the outcomes for a carbon neutral scenario based on Intermittent Renewable Energy (IRE) to be less costly in the long term.

    Download full text (pdf)
    fulltext
  • 10.
    Ahmed, Samar
    et al.
    Heimstaden AB, Sweden.
    Truong, Nguyen Le
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Analysis of future carbon-neutral energy system: The case of Växjö Municipality, Sweden2022In: Smart Energy, ISSN 2666-9552, Vol. 7, article id 100082Article in journal (Refereed)
    Abstract [en]

    In line with the Swedish target of carbon neutrality by 2045, the municipality of Växjö in Kronoberg County has set its own target to be carbon neutral in 2030. Currently, the Municipality's partially decentralized energy system relies heavily on interconnected electricity supply from the national grid, and fuels imports from other parts of Sweden. Under this circumstance, several concerns arise, including: in which ways future demand changes induce supply changes, and whether a future carbon-neutral energy system will be less costly in a sustained-electricity supply condition. In this study, techno-economic evaluations are conducted for different carbon-neutral scenarios for Växjö’s future energy system in 2030 and 2050, using an hour-by-hour dynamic energy simulation tool of EnergyPLAN. Projections for the future energy demands for Växjö were developed and modeled, based on the development strategies and on the national sustainable future scenarios in Sweden. Results for the Växjö’s carbon-neutral scenarios showed that the current energy system is sufficient to satisfy future heat demand. However, fulfilling demands of electricity for all sectors and fuels for transport and industry is a challenge. In the short term and at increased energy demand and price, being carbon neutral is technically viable without major changes in energy supply technologies. However, in the long term, investment for intermittent renewable energy resources, together with carbon capture and storage is considered to be viable financially. Therefore, planning for a carbon-neutral Växjö based on local investments showed to be a feasible strategy.

    Download full text (pdf)
    fulltext
  • 11.
    Albers, Eva
    et al.
    Chalmers University of Technology, Sweden.
    Malmhäll-Bah, Eric
    Chalmers University of Technology, Sweden.
    Olsson, Joakim
    Chalmers University of Technology, Sweden.
    Sterner, Martin
    KTH Royal Institute of Technology, Sweden.
    Myers, Joshua J
    Chalmers University of Technology, Sweden.
    Nylund, Göran M
    University of Gothenburg, Sweden.
    Rupar-Gadd, Katarina
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Abdollahi, Mehdi
    Chalmers University of Technology, Sweden.
    Cvijetinovic, Suzana
    Chalmers University of Technology, Sweden.
    Welander, Ulrika
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Edlund, Ulrica
    KTH Royal Institute of Technology, Sweden.
    Henrik, Paiva
    University of Gothenburg, Sweden.
    Undeland, Ingrid
    Chalmers University of Technology, Sweden.
    Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass2021In: Algal Research, ISSN 2211-9264, Vol. 55, article id 102261Article in journal (Refereed)
    Abstract [en]

    Saccharina latissima biomass cultivated along the Swedish west coast was subjectedto four different scalable preservation methods after harvest; freezing, sun-drying,oven-drying and ensiling. Freeze-drying and freezing at -80 °C were also included toprovide dry and wet references. The effects of the different preservation methods onthe composition of Saccharina biomass (on dry weight, DW, basis), and the recoveryas well as properties of high-quality protein, alginate and biogas were evaluated. Sundrying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods.Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass,while mannitol and laminarin were reduced compared to the other biomasses. Ovendryingand -20 °C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasseswhich translated into the lowest total seaweed protein recovery using the pH-shiftprocess. Highest protein yield was obtained with the freeze-dried reference. Ensilinglead to a significant decrease in the molecular weight of alginate, while sun-dryingcaused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield inthe anaerobic digestion experiments while freezing at -80 °C gave the highest yield,closely followed by freezing at -20 °C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima ,and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.

    Download full text (pdf)
    fulltext
  • 12.
    Ali, Ahmad
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Siting Analysis of Anaerobic Digestion Plant in Zahle District, Lebanon Using the GIS-AHP Framework2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a result of the significant increase in population, urbanization, the lack of societal awareness, and the lack of sustainable strategies and appropriate policies for solid waste management, the problem of solid waste management has become a significant threat to the environment and living organisms in developing countries. The situation is not in the best condition in the Zahle district in Lebanon, as the lack of funding and expertise, the absence of legal systems and the Syrian refugee crisis are the most prominent obstacles faced by the municipalities of Zahle district for the optimal management of municipal solid waste (MSW). In the Zahle district, most MSW is disposed of in landfills. This approach includes several drawbacks, such as occupying large areas and becoming an environmental threat. In this paper, a review was conducted of the most common technologies for recovering energy from MSW. Based on that, anaerobic digestion (AD) technology as a potentially effective option for converting waste into energy was selected for adoption in the Zahle district. However, the main objective of this analysis was the site suitability analysis by implementing the Analytic Hierarchy Process (AHP) in a Geographic Information System (GIS) model to assess the land suitability for the AD plant. AHP was used to estimate the weights and thus determine their relative importance in the site selection of the AD plant. ArcGIS software was used to analyze the site suitability of an AD plant in this research. The map of the potential locations of the AD plant was divided into five classes: Highly suitable, most suitable, suitable, moderately suitable, and low suitable. The results indicated that the highly suitable class with an area of 1867.5 hectares contained three zones suitable for building an AD plant, according to its proximity to the current sites of sanitary landfills. Accordingly, Zone 3 with 66.79 ha was identified as the most suitable site for establishing an AD plant. The research can help decision-makers in the Ministry of Environment and the Zahle municipalities choose the appropriate technology for energy recovery from waste and select a suitable site for that plant.

  • 13.
    Ali, Ahmed
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Dynamic modelling of electricity arbitrage for single-family homes: Assessing the cost-effectiveness of implementing Energy Storage and Demand-Side Load Management.2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the context of electricity, arbitrage trading involves taking advantage of existing price variations within electricity markets. The report conducted financial modelling for energy storage systems and demand-side load management for electricity arbitrage trading in single-family homes. The analysis included two different energy storage systems: a thermal energy storage system and a battery energy storage system. Additionally, electricity spot cost reduction was compared between electricity arbitrage trading and traditional energy efficiency measures such as air-to-water and ground-source heat pumps.

    The report's findings indicated that air-to-water and ground-source heat pumps emerged as the most economically viable choices for reducing electricity spot costs, irrespective of the studied electricity price area. The thermal energy storage system, employing an insulated hot water storage tank, ranked the third most efficient in achieving cost savings. The battery energy storage system, represented by a lithium home battery system, demonstrated the lowest rate of cost saving among the analyzed energy efficiency measures. 

    The financial modelling highlighted the economic potential for thermal energy storage systems, particularly in southern Sweden's electricity price areas SE3 and SE4. On the other hand, no economically viable options for battery energy storage systems were identified, regardless of the studied electricity price area. As a results, the report recommends utilizing thermal energy storage systems and implementing demand-side load management as strategies to hedge against future electricity price volatility.

    Download full text (pdf)
    fulltext
  • 14.
    Ali, Hassan
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Investigation of impact of detached house buildings orientation on energy saving result of renovation scenarios and energy generation of installed PV panels in Växjö2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Most of the detached houses in Sweden were built more than 30 years ago, and most of them are oldand need a deep renovation. The renovation is an excellent opportunity to apply the energy measure witha combination of renewable energy such as PV solar, which could be a great option to reduce energyconsumption and contribute to reducing greenhouse emissions. For this reason, selecting effectiverenovation scenarios for buildings could be important and challenging. One of these challenges isapplying typical scenarios for one archetype's buildings. A building could be in the same archetypeswith similar geometry and properties but in different directions. In this study, the researcher aims toinvestigate the yearly heat demand energy saving of buildings from one archetype, the same renovationscenario, and the same area but in four different directions, 0-30-60-90 degrees from the south (casestudies).This project's additional aim is to examine the electricity generation from PV when installedon one and both sides for four houses in the same area in four different directions, 0-30-60-90 degreesfrom the south.

    Design Builder software was used as a graphical user interface through the Energy Plus engine. In thisway, the heat demand of case studies was simulated for different scenarios (Standard renovation andadvanced renovation) in the Växjö region. The results from the simulation of the houses with differentdirections showed that the heat demand energy decreased by, on average, 20% for standard and 28% foradvanced renovation. The comparison of the case studies with the same renovation scenario concludesthat they are no differences in the heat energy savings, which means the direction of the building has nobig impact on the energy saving of the renovation scenario in the Växjö region. The installation side ofthe PV has no impact on the annual electricity generation from PV for the house with a direction of 0degrees from the south. For the other houses, the yearly electricity generation from the PV increased by36.8% with one side on the roof (South direction). House number 4 is the best direction to install PVwith one side on the roof (south direction), and house 3 is the next best direction to install PV on oneside.

    When installed on both sides of the roof, the annual electricity generation from the PV decreased by5,3% with four houses in different directions. The changes are not so high may be due to the weather ofthe Växjö, which is 65 % cloudy according to the weather data file from TMY. Another reason is thatthe PV was installed on both sides of the pitched roof. When the houses have different directions, 0 to90 degrees from the south, that may be increased the electricity generation from the PV on one side andreduce it on the other.

    Download full text (pdf)
    fulltext
  • 15.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Elastic Properties and Hardness of Mixed Alkaline Earth Silicate Oxynitride Glasses2022In: Materials, E-ISSN 1996-1944, Vol. 15, no 14, article id 5022Article in journal (Refereed)
    Abstract [en]

    The incorporation of nitrogen as a second anion species into oxide glasses offers unique opportunities for modifying glass properties via changes in glass polymerization and structure. In this work, the compositional dependence of elastic properties and the nanoindentation hardness of mixed alkaline-earth silicate oxynitride glasses containing a high amount of nitrogen (>15 at.%, c.a. 35 e/o) were investigated. Three series of silicon oxynitride glass compositions AE-Ca-Si-O-N glasses (where AE = Mg, Sr, and Ba) having varying amounts of modifiers were prepared using a new glass synthesis route, in which a precursor powder of metal hydrides was used. The obtained glasses contained high amounts of N (19 at.%, c.a. 43 e/o) and modifier cations (26 at.%, c.a. 39 e/o). Mg-Ca-Si-O-N glasses had high values of nanohardness (12-16 GPa), along with a reduced elastic modulus (130-153 GPa) and Young's modulus (127-146 GPa), in comparison with the Sr-Ca- and Ba-Ca-bearing oxynitride glasses. Both the elastic modulus and the nanohardness of AE-Ca-Si-O-N glasses decreased with an increase in the atomic number of the AE element. These property changes followed a linear dependence on the effective cation field strength (ECFS) of the alkaline earth (AE) modifier, according to their valences and ionic radii. No mixed alkaline-earth effect was observed in the current investigation, indicating that the properties were more dictated by the nitrogen content.

    Download full text (pdf)
    fulltext
  • 16.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Glass surface modification by aerosol technique2016Other (Refereed)
    Abstract [en]

    Glass has been a key material for many important advnces in cilivilization.  Currently there is much scientific and technological interest to obtained flat/float glass surface that has extremely highly resistant to abrasion, anti-fingerprint, surface contamination and optical dimming. The aim of current project is to develop new routes to modify the glass surface in order to increase functionality and enhance performance in various existing and future areas of application. This will be achieved by modifying the glass surface by incorporating nitrogen to the flat/float glass surface by deposition of thin coatings of AlN, Si3N4 and TiN. This will be achieved by gas to particle conversion by physiochemical routs. Thin films of elemental nitrides have not been reported previously by aerosol technique and we anticipate that these can be used to enhance the mechanical, optical and chemical properties of flat/float glass surface. Techniques used for structural and physical characterization include, SEM, TEM, AFM, Raman, thermal analysis, mechanical and optical measurements. Areas of applications of these modified surfaces include automotive, architectural, laser optics, camera lenses, optical filters and display technologies.

  • 17.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Hard and Transparent Thin Films2018In: 4th Nanotechnology Congress and Expo  (GNCE-18), Dubai, UAE (16-18 Apr 2018), 2018, p. 14-Conference paper (Refereed)
  • 18.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    High temeperature synthesis of nitrogen rich glasses in alkaline-earth silicon oxynitride systems2018In: Presented at XVI International IUPAC Conference on High Temperature Materials Chemistry, Ekaterinaburg, Russia, 2018, p. 24-Conference paper (Refereed)
  • 19.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Impact of the Atomic Packing Density on the Properties of Nitrogen-Rich Calcium Silicate Oxynitride Glasses2022In: Materials, E-ISSN 1996-1944, Vol. 15, no 17, article id 6054Article in journal (Refereed)
    Abstract [en]

    In this work, the impact of the atomic packing density/fractional glass compactness of Ca-Si-O-N glasses on glass transition and crystallization temperatures, glass density, microhardness, molar volume, and refractive index were examined. It was found that the atomic packing density increased with increasing the nitrogen content and decreased with increasing the Ca content in the glass network. Furthermore, density, glass transition and crystallization temperatures, and refractive index, increased with an increasing atomic packing density of the glass, while molar volume increased with decreasing atomic packing density values. The change in hardness with atomic packing density is less clear and suggests that the atomic packing density does not solely control the underlying deformation mechanism. There is indeed competition between densification (favored at low packing density values) and isochoric shear (at larger packing density). Despite that, the effects of nitrogen as a network former and Ca as a modifier are significantly independent. The obtained results indicate that the atomic packing density of the prepared samples linearly depends on many mechanical and optical properties, suggesting that the glass network and cross-linking are proportional to the ionic radius of the Ca and the nitrogen content, respectively.

    Download full text (pdf)
    fulltext
  • 20.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    New Oxynitride Glasses and Thin Films2017In: 15th International Symposium on Advanced Materials (ISAM), Islamabad, Pakistan, 16-20 Oct 2017, 2017Conference paper (Refereed)
  • 21.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Nitrogen rich Glasses and Glass Surfaces for High-tech and Specialty Applications2017Report (Refereed)
    Abstract [en]

    The aim of this project is to produce more chemical and mechanically durable glasses and glass surfaces having high thermal, mechanical and optical properties. The development of new materials is fundamental for the technological progress; their preparation and characterization lead to breakthrough applications as well as progress in our understanding of basic solid state materials properties. Glasses play an important role in our society and are expected to do so even more in the future. In the current proposed project we would like to extend the M-Si-O-N  ( M= Ca and Sr) system to T-Si-O-N (T= Transition metals e.g. Ti, Zr, Y, Mn etc) and Ln-Si-O-N ( Ln = Lanthanoids e.g. La, Ce, Pr, Eu, Gd, etc) systems. Applications of these nitrogen rich glasses include, as potential materials for use in more light-weight applications in modern communications equipment, in biomedical devices and where reductions in energy usage are critical. Furthermore, these glass materials can be used as a passive coatings on electronic substrates using their higher dielectric constants and elastic moduli to best advantage; special windows where their higher elastic moduli would allow them to remain stiff in thinner sections, thus allowing weight and energy savings; hard disk drives, again making use of higher modulus and lower densities to achieve higher rotation speeds; new bioactive oxynitride glasses and glass-ceramics with better load-bearing properties.

  • 22.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Novel thin films in the M-Si-O-N systems2019In: Presented at the Fourth International Conference on Nanomaterials: Synthesis, Characterization and Applications (ICN 2019). 12-14 April 2019, Kerala, India, 2019, p. 7-7Conference paper (Refereed)
  • 23.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Primary Challenges in the Development of Nitrogen Rich Oxynitride Glasses2018Conference paper (Refereed)
  • 24.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Bogdonoff, Toni
    Jönköping University.
    Seifeddine, Salem
    Jönköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Hardness, elastic modulus and refractive index of oxynitride glasses prepared from woody biofuel ashes2017In: Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B, ISSN 1753-3562, Vol. 58, no 6, p. 231-236Article in journal (Refereed)
    Abstract [en]

    This paper reports the hardness, elastic modulus and refractive index values of the oxynitride glasses prepared from woody biofuel ashes. The glasses were prepared in nitrogen atmosphere at 1350–1500°C with addition of Ca metal as a precursor to the extra addition of this modifier. The glasses were homogenous, but appeared translucent grey to black. They contained up to 23 eq% of Ca and 5 eq% of N. The glass densities vary slightly between 2.76 to 2.92 g/cm3. The molar volume and compactness values vary between 8.01 cm3/mol to 8.31 cm3/mol and 0.446 to 0.462 respectively. Mechanical properties like hardness and reduced elastic modulus show values, up to 10 and 105 GPa, respectively. These properties are strongly correlated with the amount of N in the glass. The refractive index (1.54–1.75) increases with increasing N and Ca contents.

  • 25.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Ellison, Adam
    Glass Science and Technology Corning Incorporated, USA.
    Luo, Jian
    Glass Science and Technology Corning Incorporated, USA.
    Edén, Mattias
    Stockholm University, Sweden.
    Composition–structure–property relationships of transparent Ca–Al–Si–O–N oxynitride glasses: The roles of nitrogen and aluminum2023In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 106, no 3, p. 1748-1765Article in journal (Refereed)
    Abstract [en]

    We explore the formation and composition–structure–property correlations of transparent Ca–Al–Si–O–N glasses, which were prepared by a standard melt-quenching technique using AlN as the nitrogen source and incorporating up to 8 at.% of N. Their measured physical properties of density, molar volume, compactness, refractive index, and hardness—along with the Young, shear, and bulk elastic moduli—depended roughly linearly on the N content. These effects are attributed primarily to the improved glass-network cross-linking from N compared to O, rather than the formation of higher-coordination AlO5 and AlO6 groups, where 27Al magic-angle-spinning nuclear magnetic resonance experimentation revealed that aluminum is predominately present in tetrahedral coordination as AlO4 units. Yet, several physical properties, such as the refractive index along with the bulk, shear, and Young's elastic moduli, increase concomitantly with the Al content of the glass. We discuss the incompletely understood mechanical–property boosting role of Al as observed both herein and in previous reports on oxynitride glasses, moreover suggesting glass-composition domains that are likely to offer optimal mechanical properties. 

    Download full text (pdf)
    fulltext
  • 26.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Hakeem, Abbas Saeed
    King Fahd Univ Petr & Minerals, Saudi Arabia.
    Eriksson, Mirva
    Stockholm University, Sweden.
    Wójcik, Natalia A.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gdansk Univ Technol, Poland.
    A novel approach for processing CaAlSiON glass-ceramics by spark plasma sintering: Mechanical and electrical properties2022In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 42, no 1, p. 96-104Article in journal (Refereed)
    Abstract [en]

    Lithium containing glassy materials can be used as solid electrolytes or electrode materials for lithium-ion batteries due to their high energy density. Conventional melt-quenched Ca11Al14Si16O49N10 glass powder containing 24 e/o N, doped with Li-ions (1, 3, and 6 wt. %) and sintered by spark plasma sintering technique (SPS) was studied. The benefits of using SPS to produce glass-ceramics are rapid heating rates compared to conventional consolidation techniques and tuning of properties, adjusting the temperature, holding time (closed to Tg temperature), heating rate (solidification), and pressure (densification) profile during the heat treatment using SPS. Pure glass and glass-ceramic were obtained under identical SPS conditions and compared with pristine oxynitride and soda-lime-silicate (float) glasses. XRD and SEM analysis confirmed that increasing the amount of Li increases the crystallinity in the glass matrix. Nano-indentation analysis showed a decreased hardness and reduced elastic modulus values with the addition of Li-ions. The direct current conductivity increases with the addition of Li due to the high mobility of Li-ions. However, the float glass sample doped with 6 wt.% of Li exhibits even higher values of D.C. conductivity, than the analogously doped Ca11Al14Si16O49N10 glass. The magnitude of activation energy (more than 1 eV) is typical for an ion hopping mechanism and the D.C. conduction mechanism is dominated by Li+ hopping.

  • 27.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Difficulties associated with the formation of oxynitride glasses2014Conference paper (Refereed)
  • 28.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Properties of nitrogen rich mixed La-Pr silicon oxynitride glasses2014Conference paper (Refereed)
  • 29.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Thermal and mechanical properties of mixed modifier oxynitride glasses2016In: Proceeding of International conference on thermal analysis and calorimetry in Russia (RTAC-2016): 16–23 September, 2016 Saint-Petersburg, Russia, Volume I, St. Petersburg: Peter the Great St.Petersburg Polytechnic University , 2016, Vol. 1, p. 136-139Conference paper (Refereed)
    Abstract [en]

    Nitrogen rich oxynitride glasses in Ca-Sr-Si-O-N system were prepared by the novel synthesis route in which the modifier is used as a metal instead of metal oxide. The results show high values of glass transition (912C), and crystallization temperatures (1140C) and hardness (10.50 GPa). The viscosity increases significantly with the nitrogen content and the apparent viscosity activation energies, ranging from 855 to 2170 kJ/mole. These glasses can be classified as being both very refractory and very fragile.

  • 30.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Thermal properties of calcium silicon oxynitride glasses2015Conference paper (Refereed)
    Abstract [en]

    Oxynitride glasses are a branch of high performance glasses, obtained by incorporation of nitrogen atoms into oxide glass network. [1-3]Oxynitride glasses have superior mechanical, rheological and optical properties as compared to their oxide glass counter partner [2-5]. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. Ca- Si-O-N glasses containing high amount of nitrogen and modifiers have been prepared by melting the mixture of CaH2, SiO2 and Si3N4 powder in nitrogen atmosphere. The glasses were characterized by X-ray powder diffraction, differential thermal analysis and scanning electron microscopy. The obtained glasses were found to be homogenous, and having colour opaque black[3]. These glasses show high values of glass transition temperature (1050°C), and crystallization temperatures (1150°C) measured by differential thermal analysis.  Generally the Ca-Si-O-N glasses thermal properties evolve approximately linearly with the nitrogen content. The viscosity increases significantly with the nitrogen content and reaches viscosity values close to reported values for rare-earth silica oxynitride glasses. The apparent viscosity activation energies are very high, ranging from 855 to 2170 kJ/mole. These nitrogen rich glasses can accordingly be classified as being both very refractory and very fragile.

     

  • 31.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    J. Pomeroy, Michael
    University of Limerick, Ireland.
    Stuart, Hampshire
    University of Limerick, Ireland.
    Issues associated with the development of transparent oxynitride glasses2015In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 41, no 3, p. 3345-3354Article in journal (Refereed)
    Abstract [en]

    Oxynitride glasses and glass ceramics are increasingly recognized as potential materials in specialist applications in modern industrial sectors. Oxynitride glasses have superior mechanical, rheological and optical properties to their oxide glass counterparts. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. In contrast to oxide glasses, oxynitride glasses are difficult to prepare which adds to production costs. Furthermore, they contain impurities in the form of elemental silicon and silicides, have poor oxidation resistance in air above their glass transition temperatures and have poor transparency in the visible region. This article reviews the above issues in relation to the potential applications of these glasses.

  • 32.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Mauro, Jan
    Penn State University, USA.
    Properties of nitrogen rich Mg-Ca-Si-O-N glasses2017In: 12th  Pacific Rim Conference on Cermics and Glass Technology including Glass & Optical Materials Meeting, Hawii, USA 21-27 May 2017, 2017, p. 180-180, article id GOMD-S1-061-2017Conference paper (Refereed)
    Abstract [en]

    Mg-Ca-Si-O-N glasses containing high amount of nitrogen have been prepared by melting the mixture of Mg metal, Ca metal, SiO2 and Si3N4 powders in nitrogen atmosphere using a radio frequency furnace. Chemical composition, surface morphology, glass transition temperature, hardness, reduced elastic modulus and refractive index of the glasses were investigated using X-ray (EDX) point analysis, scanning electron microscopy, differential thermal analysis, nanoindentation, and spectroscopic ellipsometry. Mg was substituted for Ca in these glasses. The obtained glasses were found to be homogenous, and most of them were not transparent in the visible region. These glasses show high values of glass transition temperature (1020°C), and crystallization temperatures (1150°C). The hardness and reduced elastic modulus increases upon substitution by Mg, up to 13 GPa and 150 GPa respectively. The refractive index of the glasses was found to decrease upon increasing substitution by Mg.

  • 33.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonsson, Bo
    Eklund, Per
    Birch, Jens
    Modification of float glass surfaces by novel oxy-nitride thin films2015Report (Refereed)
    Abstract [en]

    Glass is indispensable and innovative material that has plenty of applications. It is an essential component of numerous products that we use every day, most often without noticing it. Glass is widely used in a variety of applications e.g. housing and buildings, automotive and transport, containers, drinking vessels, displays, insulation and optical fibers due to its universal forming ability, transparency, chemical durability, form stability, hardness relatively low price and possibility of recycling. Flat glass is a wide market of the glass industry and generally ninety percent of all flat glass produced worldwide is manufactured using the float forming process. There is a large market strive for thinner and stronger glass in order to reduce costs, save energy, and to find new applications.

    This study comprises the modification of flat/float glass surface by novel oxynitride thin films in the Mg-Si-O-N and Ca-Si-O-N systems prepared by RF magnetron sputtering technique. The aim of this work is to develop a novel process in order to improve the mechanical and optical properties of flat/float glass by deposition of external materials e.g. alkaline earth metals and nitrogen to the surface in a process with the obvious potential to be automatic in industrial processes. Both mechanical and optical properties of the glass surface have been improved by the deposition of thin films. The float glass surface modified with Mg-Si-O-N have high value of hardness of 20 GPa, elastic modulus of 175 GPa and refractive index value of 1.96 compare to the float glass having hardness of 7 GPa, elastic modulus of 72 GPa and refractive index of 1.50.  The method presented here is anticipated to be used in production in the future and would make it possible to produce larger quantities of strong flat glass for smartphone, tablet covers and display technology to a considerably lower cost.

  • 34.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Magnusson, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Pshyk, Oleksandr
    Linköping University, Sweden;Empa Swiss Fed Labs Mat Sci & Technol, Switzerland.
    Birch, Jens
    Linköping University, Sweden.
    Eklund, Per
    Linköping University, Sweden.
    le Febvrier, Arnaud
    Linköping University, Sweden.
    Effect of O/N content on the phase, morphology, and optical properties of titanium oxynitride thin films2023In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 58, p. 10975-10985Article in journal (Refereed)
    Abstract [en]

    Phase formation, morphology, and optical properties of Ti(O,N) thin films with varied oxygen-to- nitrogen ration content were investigated. The films were deposited by magnetron sputtering at 500°C on Si(100) and c-plane sapphire substrate. A competition between a NaCl B1 structure TiN1-xOx, a rhombohedral structure Ti2(O1-yNy)3, and an anatase structure Ti(O1-zNz)2 phase was observed. While the N-rich films were composed of a NaCl B1 TiN1-xOx phase, an increase of oxygen in the films yields the growth of rhombohedral Ti2(O1-yNy)3 phase and the oxygen-rich films are comprised of a mixture of the rhombohedral Ti2(O1-yNy)3 phase and anatase Ti(O1-zNz)2 phase. The optical properties of the films were correlated to the phase composition and the observation of abrupt changes in terms of refractive index and absorption coefficient. The oxide film became relatively transparent in the visible range while the addition of nitrogen into films increases the absorption. The oxygen rich-samples have bandgap values below 3.75 eV, which is higher than the value for pure TiO2, and lower than the optical bandgap of pure TiN. The optical properties characterizations revealed the possibility of adjusting the band gap and the absorption coefficient depending on the N-content, because of the phases constituting the films combined with anionic substitution.

    Download full text (pdf)
    fulltext
  • 35.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Corning Inc, USA.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Synthesis and characterization of the mechanical and optical properties of Ca-Si-O-N thin films deposited by RF magnetron sputtering2017In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 315, p. 88-94Article in journal (Refereed)
    Abstract [en]

    Ca-Si-O-N thin films were deposited on commercial soda-lime silicate float glass, silica wafers and sapphire substrates by RF magnetron co-sputtering from Ca and Si targets in an Ar/N-2/O-2 gas mixture. Chemical composition, surface morphology, hardness, reduced elastic modulus and optical properties of the films were investigated using X-ray photoelectron spectroscopy, scanning electron microscopy, nanoindentation, and spectroscopic ellipsometry. It was found that the composition of the films can be controlled by the Ca target power, predominantly, and by the reactive gas flow. Thin films in the Ca-Si-O-N system are composed of N and Ca contents up to 31 eq. % and 60 eq. %, respectively. The films thickness ranges from 600 to 3000 nm and increases with increasing Ca target power. The films surface roughness varied between 2 and 12 nm, and approximately decreases with increasing power of Ca target. The hardness (4-12 GPa) and reduced elastic modulus (65-145 GPa) of the films increase and decrease with the N and Ca contents respectively. The refractive index (1.56-1.82) is primarily dictated by the N content. The properties are compared with findings for bulk glasses in the Ca-Si-(Al)-O-N systems, and it is concluded that Ca-Si-O-N thin films have higher values of hardness, elastic modulus and refractive index than bulk glasses of similar composition. (C) 2017 Elsevier B.V. All rights reserved.

  • 36.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Paul, Biplab
    Linköping University, Sweden.
    Magnusson, Roger
    Linköping University, Sweden.
    Erik, Ekström
    Linköping University, Sweden.
    Pallier, Camille
    Linköping University, Sweden.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Eklund, Per
    Linköping University, Sweden.
    Birch, Jens
    Linköping University, Sweden.
    Optical and mechanical properties of amorphous Mg-Si-O-N thin films deposited by reactive magnetron sputtering2019In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 372, no 25, p. 9-15Article in journal (Refereed)
    Abstract [en]

    In this work, amorphous thin films in Mg-Si-O-N system typically containing >15 at.% Mg and 35 at.% N were prepared in order to investigate especially the dependence of optical and mechanical properties on Mg composition. Reactive RF magnetron co-sputtering from magnesium and silicon targets were used for the deposition of Mg-Si-O-N thin films. Films were deposited on float glass, silica wafers and sapphire substrates in an Ar, N2 and O2 gas mixture. X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, spectroscopic ellipsometry, and nanoindentation were employed to characterize the composition, surface morphology, and properties of the films. The films consist of N and Mg contents up to 40 at.% and 28 at.%, respectively and have good adhesion to substrates and are chemically inert. The thickness and roughness of the films increased with increasing content of Mg. Both hardness (16–21 GPa) and reduced elastic modulus (120–176 GPa) are strongly correlated with the amount of Mg content. The refractive index up to 2.01 and extinction coefficient up to 0.18 were found to increase with Mg content. The optical band gap (3.1–4.3) decreases with increasing the Mg content. Thin film deposited at substrate temperature of 100 °C shows a lower value of hardness (10 GPa), refractive index (1.75), and higher values of reduced elastic modulus (124 GPa) as compared to the thin film deposited at 310 °C and 510 °C respectively, under identical synthesis parameters.

  • 37.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Greczynski, Grzegorz
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Novel transparent Mg-Si-O-N thin films with high hardness and refractive index2016In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 131, p. 1-4Article in journal (Refereed)
    Abstract [en]

    There is an increasing demand for glass materials with better mechanical and optical properties for display and electronic applications. This paper describes the deposition of novel thin films of Mg-Si-O-N onto float glass substrates. Amorphous thin films in the Mg-Si-O-N system with high nitrogen and magnesium contents were deposited by reactive RF magnetron co-sputtering from Mg and Si targets in Ar/N2/O2 gas mixtures. The thin films studied span an unprecedented range of compositions up to 45 at% Mg and 80 at% N out of cations and anions respectively. Thin films in the Mg-Si-O-N system were found to be homogeneous and transparent in the visible region. Mechanical properties like hardness (H) and reduced elastic modulus (Er) show high values, up to 21 GPa and 166 GPa respectively. The refractive index (1.87-2.00) increases with increasing magnesium and nitrogen contents.

  • 38.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Linköping University, Sweden.
    Magnusson, Roger
    Linköping University, Sweden.
    Greczynski, Grzegorz
    Linköping University, Sweden.
    Broitman, Esteban
    Linköping University, Sweden.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University, Sweden.
    Birch, Jens
    Linköping University, Sweden.
    Thin films in M-Si-O-N thin systems2017In: 44th International Conference on Metallurgical Coating and Thin Films (ICMCTF), San Diego, CA, USA, 24-28 Apr 2017, 2017Conference paper (Refereed)
  • 39.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Magnusson, Roger
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Birch, Jens
    Study of SiN, SiON and Mg-Si-O-N thin films by spec-troscopic elipsometry2016In: Optics and photonics conference, 2-3 November, 2016, Linköping, Sweden, 2016Conference paper (Refereed)
  • 40.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Ryl, Jacek
    Gdańsk University of Technology, Poland.
    Hakeem, Abbas Saeed
    King Fahd University of Petroleum and Minerals, Saudi Arabia.
    Grochowska, Katarzyna
    Polish Academy of Sciences, Poland.
    Wójcik, Natalia A.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gdańsk University of Technology, Poland.
    Investigation of the structural and thermal properties of aluminum-rich Ca–Al–Si–O–N glasses2023In: Progress in Solid State Chemistry, ISSN 0079-6786, E-ISSN 1873-1643, Vol. 71, article id 100414Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate the structure and thermal properties of aluminum-rich transparent Ca–Al–Si–O–N glasses. The obtained glasses were prepared by a traditional melt-quenching technique at 1650 °C using AlN as the nitrogen source. The obtained glasses have a nAl/nSi>1 and contain up to 17 eq.% of N. The structure of the glasses was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, infrared, and Raman spectroscopy techniques. The structure analysis shows a higher preference for Si–N bond formation relative to Al–N bond formation and aluminum is predominately present in tetrahedral coordination as AlO4 units. The thermal properties of samples were studied by differential thermal analysis and the obtained glass transition temperature ranges from 875 °C to 950 °C, and is primarily influenced by the N content. The glass stability can be correlated with both the N and Al contents in the studied glasses. It is improved due to the increased degree of network polymerization by the incorporation of nitrogen.

  • 41.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Wójcik, Natalia A.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gdansk Univ Technol, Poland.
    Hakeem, Abbas Saeed
    King Fahd Univ Petr & Minerals, Saudi Arabia.
    Gueguen, Yann
    Univ Rennes, France.
    Karlsson, Stefan
    RISE, Sweden.
    Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca2024In: Progress in Solid State Chemistry, ISSN 0079-6786, E-ISSN 1873-1643, Vol. 74, article id 100461Article, review/survey (Refereed)
    Abstract [en]

    The primary objective of this study is to explore the relationship between the composition, structure, and thermal characteristics of M-Al-Si-O-N glasses, with M representing sodium (Na), magnesium (Mg), or calcium (Ca). The glasses were prepared by melting in a quartz crucible at 1650 degrees C and AlN precursor (powder) was utilized as a nitrogen source. The measured thermal properties studied were glass transition temperature (Tg), crystallization temperature (Tc), glass stability, viscosity, and thermal expansion coefficient (alpha). The findings indicate that increasing the aluminum content leads to higher glass transition, crystallization temperatures, and viscosities. In contrast, fragility values increase with the Al contents, while modifier elements and silicon content influence thermal expansion coefficient values. FTIR analysis revealed that in all glasses, the dominant IR bands are attributed to the presence of Q2 and Q3 silicate units. The effect of Al is observed as a progressive polymerization of the silicate network resulting from the glass-forming role of Al2O3. In most samples, the Q4 silicate mode was also observed, strongly related to the high Al content. Overall, the study shows that the complexity of composition-property correlations where the structural changes affect the properties of Mg/Ca-based oxynitride glasses has potential implications for their use in various technological fields.

  • 42.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Wójcik, Natalia A.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gdańsk University of Technology, Poland.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Kamitsos, Efstratios
    Theoretical and Physical Chemistry Institute, Greece.
    Li, Xinghua
    Corning Incorporated, USA.
    Luo, Jian
    Corning Incorporated, USA.
    Möncke, Doris
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Alfred University, USA.
    Synthesis, structural characterization, and thermal properties of Ca- and La-doped soda-lime glasses by laser melting2020In: International Journal of Applied Glass Science, Vol. 11, no 4, p. 699-706Article in journal (Refereed)
    Abstract [en]

    Laser melting techniques have been used in the preparation of unconventional glasscompositions with high melting temperatures. Thus, we wanted to test the feasibilityof using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitridesilicate glasses. Melting from oxides and metallic raw materials, we wanted to studyfirst glass formation and possible evaporation losses of the glass components. Twoglass series were prepared and studied for their structure and thermal properties, onewith Ca2+- and a higher melting La3+-doped soda-lime-silicate (SLS) series. In lessthan 3 minutes of laser melting, spheres of up to 6 mm diameter were successfullyfabricated. The obtained glass samples were homogeneous and transparent in thevisible region. X-ray diffraction and Raman spectroscopic analysis confirmed theamorphous nature of the synthesized samples. Sodium losses increase as calcium isadded to the soda-lime-silicate glass. As expected, increasing Ca2+ or La3+ additionlead to increased depolymerization of the silicate network. Moreover, the increasesin Tg with the addition of Ca2+ or La3+ ions indicating strengthening of the sodalime-silicate glass by increasing strength of the M-O bonds of divalent and trivalentions over monovalent sodium ions, weak Na-O bonds also resulting in significantevaporation loss during the short laser melting times. The thermal stability decreasesupon addition of Ca2+ or La3+ ions to the soda-lime-silicate glasses.

  • 43.
    Alice, Landmér
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Wet spinning of carbon fiber precursors from cellulose-lignin blends in a cold NaOH(aq) solvent system2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Carbon fiber (CF) is predominantly produced from fossil-based sources and is therefore an area of interest for further development towards a more sustainable society. The purpose of this thesis work was to investigate the possibility of producing precursor fibers (PFs) for CF production from a blend of renewable cellulose andlignin. Cellulose, which is used to some extent for CF production, was chosen, while the possibility of adding lignin was investigated in hope of increasing the gravimetric yield of the CF production. Blends of softwood kraft cellulose pulp (SKP) and softwood kraft lignin (SKL) were dissolved in an alkaline (NaOH) solvent system at different cellulose/lignin ratios. A total of eight dopes were prepared (SKP/SKL ratios of 100/0–60/40 wt./wt.) with total dope concentrations ranging from 4.5 wt.% to 9.2 wt.%. The addition of SKL resulted in dark colored dopes with viscosities of which mainly appeared to depend on the SKP concentration. The dopes were wet spun, resulting in continuously spun PFs. The PFs showed on an increasing pyrolysis yield with increased SKL content but decreasing mechanical properties. However, process optimization was not included in the work, subsequently leading to the assumption that greater values on mechanical properties can be achieved. A pure SKP PF and a SKP-SKL (70/30 wt./wt.) PF were successfully thermally converted into CFs by carbonization at 1000 °C. The PF containing SKL had a total gravimetric yield more than twice as high as the pure SKP PF, 28 wt.% and 12 wt.%, respectively. Thereby, the addition of SKL seems to have a positive impact on the CF yield when utilizing a NaOH(aq) solvent system. This thesis work has become a base for the future work towards the development of CFs from wet spun cellulose-lignin PFs in the NaOH(aq) solvent system.  

    Download full text (pdf)
    fulltext
  • 44.
    Al-Mamun, Abdullah
    et al.
    Sultan Qaboos University, Oman.
    Ahmad, Waqar
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Sultan Qaboos University, Oman.
    Jafary, Tahereh
    Sultan Qaboos University, Oman;International Maritime College, Oman.
    Nayak, Jagdeep Kumar
    Sultan Qaboos University, Oman.
    Al-Nuaimi, Ali
    Sultan Qaboos University, Oman.
    Sana, Ahmad
    Sultan Qaboos University, Oman.
    Recent advances in microbial electrosynthesis system: Metabolic investigation and process optimization2023In: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295X, Vol. 196, article id 108928Article in journal (Refereed)
    Abstract [en]

    The intensified burning of fossil fuels and the discharging of industrial wastes are severe threats to the environment. The released CO2 and organic fractions of industrial and municipal wastes exacerbate global warming. Converting the released CO2 and organic wastes into beneficial electricity and biofuel-chemicals is deemed an environmental necessity. Microbial electrosynthesis (MES) presents a promising technology for bio-electrochemical conversion of released CO2 and organic wastes into electricity and biofuel-chemicals using external-powered and/or self-powered microbial oxidation/reduction processes. The MES system consists of anodic and cathodic processes. The technology mostly relies on the capacity of electron transfer from electroactive biofilm to the electrode for reducing organics into value-added chemicals and sustaining their respiration and growth. The current review aims to summarize and explore the diversified application of electrogenic microbes and their metabolic pathways of electron transfer. It also summarizes the MES reactor design and operational parameters that influence the catalysis of biofilm and hence, the system performance. The review concludes with a critical evaluation of technical challenges that should be overcome before large-scale implementation. Furthermore, various recommendations on technical perspectives for successful implementation and application, including future research directions, are presented in this study.

  • 45.
    Almeida, Roma
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Mainali, Brijesh
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Analytical review of methodological approaches for measuring circularity in building renovation2023In: Proceedings of the International Conference “Sustainable Built Environment and Urban Transition”: 12-13 October, Växjö, Växjö: Linnaeus University Press, 2023Conference paper (Refereed)
    Abstract [en]

    Circularity in construction industry requires understanding of the complex system dynamics, which are affected by various building layers and societal systems. While the existing building stock offers opportunities to enable re-looping of construction and demolition waste, the assessment of building circularity performance is not straightforward, due to lack of standard database, methods, and tools. This may lead to subjective interpretations by practitioners who rely on lifecycle assessment (LCA) approach complemented with circularity indicators (C-indicators) to know the level of circularity (LOC) of building materials, components, and elements. Thus, these C-indicators requires careful evaluation of the current methodological approaches. The aim of this paper is to map and evaluate the nexus between assessment methodologies highlighting their strengths, limitations, and areas of improvement. In this study, a complementary approach of systematic literature review and design research concept was used to classify seven primary aspects covering 18 key performance indicators, that impact the system thinking approach of the renovation project. The critical analysis of ten distinguished C-indicators show conditional, beneficial and trade-off relationships between various indicators. At the same time, the dynamic aspect of re-looping the resources is missing in these indicators and sustainability is accounted by complementing lifecycle impacts rather than coupling them. Results of this review highlight substantial gaps in C-indicators applicability for renovation projects with emphasis to formulate a practical guidance to assess recirculation of materials throughout the value chain. 

    Download full text (pdf)
    ANALYTICAL REVIEW OF METHODOLOGICAL APPROACHES FOR MEASURING CIRCULARITY IN BUILDING RENOVATION
  • 46.
    Andersson, Ida
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Optimal fönsterstorlek: En optimering av fönsters storlek och konstruktion för att skapa ett stort dagsljusinsläpp och en liten solvärmelast2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inom EU ska alla nyproducerade byggnader ha en energiförbrukning nära noll senast den sista december 2020. Region Kalmar Län genomför omfattande byggnationer av lokaler för psykiatrisk vård. Genom att ta fram en optimal fönsterstorlek för två typrum, ett undersökningsrum och en expedition, kan energiförbrukningen under lokalernas drift minimeras. Målet är att tafram en optimal fönsterstorlek och konstruktion så att målen för solvärmelast och dagsljus uppnås i rummen enligt Miljöbyggnad 3.0. Ett fönsters g-värde anger hur stor del av solinstrålningen som transmitteras genom glaset, ett lågt g-värde ger en lägre solvärmelast i ett rum. Ett fönsters LT-värde anger hur stor del av det synliga ljuset som transmitteras genom glaset, ett högt LT-värde ger ett större dagsljusinsläpp. Den största möjliga glasarean för uppfyllande av kraven för solvärmelast räknasut för flera g-värden. Den minsta möjliga glasarean för uppfyllande av kraven för dagsljus simuleras för flera olika LT-värden i Velux Daylight Visualizer. De g-värden och LT-värden som är möjliga att kombinera ur ett areaperspektiv tas fram genom att jämföra största och minsta möjliga glasarea. De alternativ som har ett motsvarande verkligt fönsterglas som ger låg solvärmelast och stort dagsljusinsläpp väljs. För undersökningsrummet väljs ett 1,40 m2 stort glas med g-värde 0,41 och LT-värde 0,66. För expeditionen väljs ett 1,04 m2 stort glas med g-värde 0,33 och LT-värde 0,62. Energiförbrukningen under ett år och effekten för ett kyl- och värmesystem i de två rummen tas fram genom en energisimulering i VIP Energy.

    Download full text (pdf)
    fulltext
  • 47.
    Andersson Lindbäck, Emma
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Exploring Sustainable Resource Management Solutions in Interior Office Remodeling: A Systems Perspective on Materials and Waste2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The construction sector is the largest producer of waste in the European Union (EU) and each EU member state needs to take the necessary steps to reduce the quantity of construction waste. Similarly, Sweden's construction and demolition (C&D) sector generates the majority of the country's waste. Consequently, Sweden is now striving to make its construction operations more sustainable. With an emphasis on the function of a Swedish property owner, this study attempts to explore ways of managing materials and waste from interior office remodeling projects in a sustainable manner andinvestigate challenges and opportunities while getting insights and viewpoints from different parts of the value chain. The study additionally explores what measures the property company can apply to enhance their sustainable efforts.To accomplish this, coding and thematic analysis were conducted on data obtained from semi-structured interviews with relevant stakeholders, articlesfrom peer-reviewed journals and grey literature, alongside observations gathered from site visits. The analysis resulted in nine themes that highlightthe challenges and opportunities within sustainably managing material and waste from remodeling projects. The identified themes were (1) Regulations and strategies, (2) Economic aspects, (3) Stakeholder impact, (4) Collaboration, (5) Routines, (6) Material and waste management, (7) Reuse market, (8) Quality of product and (9) Digital systems. The study discusses the findings and initiatives that support sustainable operations in interior office renovation projects and concludes with suggestions for future work and recommendations for the property company. 

    Download full text (pdf)
    fulltext
  • 48.
    Andersson Schneider, Katja
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Återvinning av restvärme i en biogasanläggning: Undersökning om värmepump som utnyttjar värme från rötrest i Hagelrums Gård/Biogas anläggning2021Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    Hagelrums Gård/Biogas is a farm that produces biomethane for transportation from anaerobic digestion. For the anaerobic digestion manure is mainly used in their facility with two digesters.

    This report investigates if installation of a heat pump that takes heat from the digestate would be economically and beneficial for heating of the first digester. The comparison will be done against the facility’s current chip boiler.

    The current facility’s operation and three different scenarios with a heat pump with COP 4 and continuous flow of digestate is presented in the result section. In the results section is also comparisons of how an installation of the proposed heat pump would affect the operation of the facility.

    The conclusion of the project is that a heat pump is not economical or suitable for the current facility. The extra costs and operation of the facility that is not optimal for a heat pump is the reasoning of the conclusion.

    Download full text (pdf)
    fulltext
  • 49.
    Andrell, Ellen
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Wisme, Tim
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Energiförluster genom avdunstning vid ett massabruk: Utveckling av ett beräkningsverktyg samt en undersökning av möjligheter för att minska energiförlusterna2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Tillverkning av papper och pappersmassa är en energikrävande process och industrin står för över 51 % av energiförbrukningen inom Sveriges industrisektor. Vid tillverkningen av kemisk pappersmassa används sulfatprocessen och då tillsätts lut i kokeriet som därefter kan återbildas i brukets lutcykel. I lutcykeln förvaras lut i cisterner och från dessa sker avdunstningsförluster.

    Syftet med examensarbetet var att lokalisera de största avdunstningsförlusterna i lutcykeln i kausticeringsprocessen på Södra Cells pappersmassabruk i Mönsterås. Dessutom gavs förslag på hur energiförlusterna kan minskas och hur den sparade energin kan nyttjas.

    Mätningar på avdunstningsförlusterna genomfördes för att kunna beräkna energiförlusterna. Dessutom togs cisterntemperaturer och lutflöden fram från Södras loggningssystem. De beräknade energiförlusterna var störst i kalkmjölkcisternen på 1,58 MW och vitlutscistern 1 på 0,97 MW. Den totala energiförlusten genom avdunstning från cisternerna i kausticeringsprocessen beräknades till 6,01 MW. Lösningar som undersökts för att minska energiförlusterna har varit att installera en ”breather valve”, nyttja ångorna i en Organic Rankine Cycle eller använda dem för att producera fjärrvärme. Det har även studerats vart den sparade energin kan användas i det undersökta massabruket.

    Download full text (pdf)
    Energiförluster genom avdunstning vid ett massabruk
  • 50.
    Arababadi, Reza
    et al.
    Grad Univ Adv Technol, Iran.
    Naganathan, Hariharan
    Wentworth Inst Technol, USA.
    Pour, Mohsen Saffari
    Shahid Bahonar Univ Kerman, Iran.
    Dadvar, Atefeh
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Parrish, Kristen
    Arizona State Univ, USA.
    Chong, Oswald
    Ira A Fulton Sch Engn, USA.
    Building stock energy modeling: Feasibility study on selection of important input parameters using stepwise regression2021In: Energy Science & Engineering, ISSN 2050-0505, Vol. 9, no 2, p. 284-296Article in journal (Refereed)
    Abstract [en]

    Building energy assessment is essential to accomplish the sustainable energy targets of new and present buildings. Retrofitting of the existing buildings by assessing them through energy models is the most prominent method. Studies revealed that there is still blank information about the building stocks, and these affect the valuation of building energy efficiency policies. Literature also recommends that the existing energy models are too complex and unreliable to predict the energy use. Reliability of such energy models would improve through a better alignment of the input parameters and the model assumptions. The authors hypothesized that the reliability of models would be improved through identification of the most relevant energy use parameters for the building stocks in different regions and models. One of the most commonly accepted methods for detecting the most dominant input parameters is sensitivity analysis, though its shortcomings include the need for a large number of data samples and long computing time. In this research, the Energy, Carbon, and Cost Assessment for Buildings Stocks (ECCABS) model is adopted to identify the most important parameters of the presented model. The research team uses the model that has been validated by studies conducted for the UK building stock. Moreover, by assessing the feasibility study with the stepwise regression to identify the significant input parameters have been discussed. Results show that stepwise regression method could produce the same results compared to sensitivity analysis. This paper also indicates that stepwise regression is considerably faster and less computationally intensive compared to common sensitivity analysis methods.

1234567 1 - 50 of 456
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf