| 1. |
- Ivanov, I. I., et al.
(författare)
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Investigation of catalytic hydrogen sensors with platinum group catalysts
- 2021
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 346
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Tidskriftsartikel (refereegranskat)abstract
- Environmental deterioration and limited resources of hydrocarbons push the development of alternative power sources. One of the most promising energy carriers is hydrogen. However, handling hydrogen is more hazardous than the use of hydrocarbons because it has a significantly wider flammable range. Thus the development of new sensors for preventing hydrogen leakage is the actual task of modern materials science and chemical engineering. In this work, the response of catalytic sensors to hydrogen with different catalysts of platinum group (Pt, Pd, Ir, Rh, Pt + Pd, Pt + Pd + Rh, Pt + Pd + Ir) in the pre-explosion concentration range is studied. Temperature dependencies of sensitivity are discussed. A hysteresis in sensor response is observed during the cycling of the supply voltage. This phenomenon can be explained by partial transformation of platinum group metal oxides into metallic phase at a temperature of more than 500 °C and reverse metal oxidation at temperatures less than 400 °C. It has been shown that the sensors with catalysts containing Ir and Rh demonstrate more preferable characteristics for practical applications. © 2021 Elsevier B.V.
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| 2. |
- Asbjørn Sörensen, Charlotte, 1972-, et al.
(författare)
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A Qualitative Study of the challenges faced by Material Designers when developing DIY-materials
- 2020
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Ingår i: <em>DS 104: Proceedings of the 22nd International Conference on Engineering and Product Design Education </em>. - Herning, Denmark : Design Society. - 9781912254101
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Konferensbidrag (refereegranskat)abstract
- The recent academic literature on material practices within design has revealed the emergence of a new design discipline, DIY-materials or material design. Designers educated in DIY-materials and the Material Driven Design method, applied in design courses in major European universities are beginning to identify themselves as material designers. This paper presents a qualitative case study of the challenges faced by material designers and design students developing DIY-materials from the stage of a small sample with promising experiential qualities and technical properties, towards a more viable material. A comparative case study of twenty-eight material driven design projects and four explorative semi-structured interviews were conducted with designers. The result suggest: (a) that designers have a tendency to focus more on the experiential attributes and aesthetical qualities rather than the technical attributes in the early stages of material development, (b) projects that are situated in specific contexts or systems have a higher success rate, (c) bio-based DIY-materials are in general sensitive to moist and high temperatures, (d) a systematic approach during tinkering combined with analytic skills are crucial for the development of DIY-materials. In this paper we also build on our previous research, regarding the development of reflective material practices for design students in higher education. It is hoped that this research can contribute to the further development of material design as a new design discipline.
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| 3. |
- Capuano Mascarenhas, Luciana, et al.
(författare)
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Multi-criteria analysis of municipal solid waste treatment technologies to support decision-making in Kisumu, Kenya
- 2021
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Ingår i: Environmental Challenges. - : Elsevier BV. - 2667-0100. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- The directive to close the dumpsite in Kisumu, Kenya has made the search for alternative solid waste treatment and disposal technologies urgent. The aim of this research is to support the decision-making process by analyzing multiple socioeconomic and environmental parameters of salient solid waste treatment options. We used multi-criteria analysis to assess and compare anaerobic digestion, sanitary landfill, bioreactor landfill, and incineration. Informed by field observations and interviews, the chosen assessment criteria were economic costs, electricity generation, GHG emissions, land footprint, air pollution, soil and water contamination, and compatibility with recycling efforts. A literature review yielded quantitative and qualitative data that supported the analysis and the ranking of solutions according to performance in each criterion. Our analysis shows that anaerobic digestion is a suitable solution for Kisumu, due to its reduced environmental impacts, production of electricity and fertilizer, suitability to treat the large organic waste stream generated in the city, and compatibility with independent recycling activities. Landfilling represents a cheap solution; however, previous failed initiatives indicate that finding available land close to main waste generators is a challenge. Incineration is costly and requires advanced air quality control equipment and high combustibility of incoming waste, which is not the case for Kisumu, where over 60% of waste stream is organic/wet. Our results and recommendations are targeted for the Kisumu case, but they can be relevant for researchers and policymakers elsewhere, especially in low- and middle-income cities facing similar challenges.
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| 4. |
- Gulma, Sadiq Abubakar, 1989-
(författare)
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Field Evaluation of Indoor Microclimates of Green and Bare Roofed Urban Buildings at No-Ventilation Condition in a Sub-Saharan Climate
- 2014
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Ingår i: American Journal of Civil Engineering. - : Science publishing group. - 2330-8729. ; 2:6, s. 143-143
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Tidskriftsartikel (refereegranskat)abstract
- There is a growing use of green roofs on urban buildings around the world with a focus on reducing energy consumption of buildings. Energy consumption of buildings results mostly from heating or cooling of indoor spaces. When mechanical air conditioners are operating, windows (natural ventilation) are shut. This paper studied 2 field models, one with a living green roof and the other left bare (conventional), both without any sensible or latent heat loss or gain via their ventilation systems. Microclimatic data was collected at the field for the 2 rooms for a period of 25 days. Two microclimate parameters, air temperature and relative humidity which determines the highest effect on indoor thermal comfort were compared for the two models and with the ambient conditions. Result shows that both air temperature and relative humidity of the room with the green roof were lower than the bare roofed house. Fluctuations were also minimal for the green roofed urban building.
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| 5. |
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Technical evaluation of a tank-connected food waste disposer system for biogas production and nutrient recovery
- 2017
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 65, s. 153-158
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a tank-connected food waste disposer system with the objective to optimise biogas production and nutrient recovery from food waste in Malmo was evaluated. The project investigated the source separation ratio of food waste through waste composition analyses, determined the potential biogas production in ground food waste, analysed the organic matter content and the limiting components in ground food waste and analysed outlet samples to calculate food waste losses from the separation tank. It can be concluded that the tank-connected food waste disposer system in Malmo can be used for energy recovery and optimisation of biogas production. The organic content of the collected waste is very high and contains a lot of energy rich fat and protein, and the methane potential is high. The results showed that approximately 38% of the food waste dry matter is collected in the tank. The remaining food waste is either found in residual waste (34% of the dry matter) or passes the tank and goes through the outlet to the sewer (28%). The relatively high dry matter content in the collected fraction (3-5% DM) indicates that the separation tank can thicken the waste substantially. The potential for nutrient recovery is rather limited considering the tank content. Only small fractions of the phosphorus (15%) and nitrogen (21%) are recyclable by the collected waste in the tank. The quality of the outlet indicates a satisfactory separation of particulate organic matter and fat. The organic content and nutrients, which are in dissolved form, cannot be retained in the tank and are rather led to the sewage via the outlet. (C) 2017 Elsevier Ltd. All rights reserved.
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| 6. |
- Bernstad Saraiva, Anna, et al.
(författare)
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Lifecycle assessment of a system for food waste disposers to tank : A full-scale system evaluation
- 2016
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 54, s. 169-177
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Tidskriftsartikel (refereegranskat)abstract
- An increased interest for separate collection of household food waste in Sweden has led to development of a number of different collection-systems - each with their particular benefits and drawbacks. In the present study, two systems for collection of food waste in households were compared; (a) use of food waste disposers (FWD) in kitchen sinks and (b) collection of food waste in paper bags for further treatment. The comparison was made in relation to greenhouse gas emissions as well as primary energy utilization. In both cases, collected food waste was treated through anaerobic digestion and digestate was used as fertilizer on farmland. Systems emissions of greenhouse gases from collection and treatment of 1 ton of food waste (dry matter), are according to the performed assessment lower from the FWD-system compared to the reference system (-990 and -770 kg CO2-eq./ton food waste dry matter respectively). The main reasons are a higher substitution of mineral nitrogen fertilizer followed by a higher substitution of diesel. Performed uncertainty analyses state that results are robust, but that decreasing losses of organic matter in pre-treatment of food waste collected in paper bags, as well as increased losses of organic matter and nutrients from the FWD-system could change the hierarchy in relation to greenhouse gas emissions. Owing to a higher use of electricity in the FWD-system, the paper bag collection system was preferable in relation to primary energy utilization. Due to the many questions still remaining regarding the impacts of an increased amount of nutrients and organic matter to the sewage system through an increased use of FWD, the later treatment of effluent from the FWD-system, as well as treatment of wastewater from kitchen sinks in the reference system, was not included in the assessment. In future work, these aspects would be of relevance to monitor. (C) 2016 Elsevier Ltd. All rights reserved.
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| 7. |
- Burlakovs, J., et al.
(författare)
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Application of anaerobic digestion for biogas and methane production from fresh beach-cast biomass
- 2022
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Ingår i: 3rd EAGE Global Energy Transition, GET 2022. - : European Association of Geoscientists and Engineers, EAGE. - 9781713863618 ; , s. 61-65, s. 1-5
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Konferensbidrag (refereegranskat)abstract
- In this research, biogas production potential from beach wrack collected in Riga Gulf (Ragaciems, Jaunķemeri, Bigauņciems) and in coastline of Sweden (Kalmar) was studied using an anaerobic digestion method. Selected beach wrack masses laying ashore and containing macroalgal biomass of common macroalgae types specific to the Baltic Sea were mixed for consolidated samples. Anoxic fermentation of untreated beach wrack was carried out in 16 bioreactors applying a single filling mode at 38 °C. The study revealed that by utilizing beach wrack accumulated ashore as a feedstock for anaerobic digestion methane can be utilized if pretreatment and conditioning of the samples are performed. The study was continued for selected brown algae containing biomass tested with three dewatering pretreatment methods: a) keeping in tap water for 24 hours; b) washing with running fresh water for one hour, and c) drying to relatively constant weight. The resulting methane outcome was compared with the data corresponding to raw brown algae. The study confirmed that washing of macroalgal biomass applied as pretreatment prior to anaerobic fermentation avoids inhibition of salts and promotes biomethane production.
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| 8. |
- Dabaieh, Marwa, et al.
(författare)
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A life cycle assessment of a 'minus carbon' refugee house : global warming potential and sensitivity analysis
- 2020
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Ingår i: Archnet-IJAR. - : Emerald Group Publishing Limited. - 1994-6961 .- 1938-7806. ; 14:3, s. 559-579
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - Over the last eight years, the Middle East has experienced a series of high profile conflicts which have resulted in over 5.6 million Syrians forced to migrate to neighbouring countries within the MENA (Middle East and North Africa) region or to Europe. That have exerted huge pressure on hosting countries trying to accommodate refugees in decent shelters and in quick manner. Temporary shelters normally carry a high environmental burden due to their short lifespan, and the majority are fabricated from industrialised materials. This study assesses the carbon impact for a minus carbon experimental refugee house in Sweden using life cycle assessment (LCA) as tool. SimaPro and GaBi software were used for the calculations and the ReCiPe midpoint method for impact assessment. The results show that using local plant-based materials such as straw, reeds and wood, together with clay dug from close to the construction site, can drastically reduce the carbon footprint of temporary shelters and even attain a negative carbon impact of 226.2 kg CO2 eq/m2. Based on the results of the uncertainty importance analysis, the overall global warming potential impact without and with sequestration potential are mostly sensitive to the variability of the GWP impact of wood fibre insulation. Design/methodology/approach - The methodology is designed to calculate the GWP impact of the refugee house over its entire life cycle (production, operation and maintenance and end of life). Then, the sensitivity analysis was performed to explore the impact of input uncertainties (selection of material from the database and the method) on the total GWP impact of the refugee house with and without sequestration. The ISO standards (International Standard 14040 2006; International Standard 14044 2006) divide the LCA framework into four steps of Goal and scope, inventory analysis, impact assessment, and interpretation. Findings - This study has shown an example for proof of concept for a low impact refugee house prototype using straw, reeds, clay, lime and wood as the principle raw materials for building construction. Using natural materials, especially plant-based fibres, as the main construction materials, proved to achieve a minus carbon outcome over the life cycle of the building. The GWP of the shelter house without and with sequestration are found to be 254.7 kg CO2 eq/m(2) and -226.2 kg CO2 eq/m(2), respectively. Originality/value - As there are still very few studies concerned with the environmental impact of temporary refugee housing, this study contributes to the pool of knowledge by introducing a complete LCA calculation for a physical house prototype as a proof of concept on how using low impact raw materials for construction combined with passive solutions for heating and cooling can reach a minus carbon outcome. The GWP of the shelter house without and with sequestration are found to be 254.7 kg CO2 eq/m2 and -226.2 kg CO2 eq/m2.
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| 9. |
- Jani, Yahya
(författare)
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Adsorption : A Cost-Effective Wastewater Treatment Technology for Removal of Conventional and Emerging Organic Contaminants
- 2022
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Ingår i: The Handbook of Environmental Chemistry. - Berlin, Heidelberg : Springer. ; , s. 17-33
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Bokkapitel (refereegranskat)abstract
- Water is a vital component for sustaining life on the earth because it is interacted with all metabolic activities of all living beings (human, plants, and others). The decomposition of organic pollutants, in general, causes oxygen deficiency in water bodies that can lead to severe damages in the ecosystem. Therefore, cost-effective innovative methods for the purification of wastewater is always needed. One of the most important methods that has gathered attention is adsorption. This method has witnessed continuous development in the case of the selected materials as adsorbents. Low cost as well as the production of new nano-materials have been used for the decontamination of water. In this chapter, a general overview based on the information available in the literature was produced to highlight the importance of adsorption as a method for the purification of water from conventional and emerging organic compounds.
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| 10. |
- Lazoroska, Daniela, et al.
(författare)
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Perceptions of participation and the role of gender for the engagement in solar energy communities in Sweden
- 2021
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Ingår i: Energy, Sustainability and Society. - : Springer Science and Business Media LLC. - 2192-0567. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Energy communities are emphasized by the EU as important for developing sustainable energy systems that include and engage many people. While many renewables are highly compatible with a more decentralized energy system, research indicates that participation in 'desirable' energy activities and energy decision-making is influenced by social and economic factors, including gender, economic status and home ownership. The overall aim of this article is to contribute to this line of inquiry by exploring how and under which conditions energy communities allow for broader participation in the energy system. This article examines how gender, as a more specific condition, influences the extent to which parties can or cannot engage with collective solar ownership models by means of a qualitative study of 11 solar energy communities and one housing association in Sweden.Results: The study revealed that despite the relative potential for inclusion that they hold, energy communities can raise justice concerns in terms of inequities concerning access, capacity, and opportunity to engage in decision-making.Conclusions: While solely focusing on gender offers a limited view of the dynamics of inclusion and exclusion in renewable energy projects, it is our position that integrating it into the analysis will provide insights into possible measures to remedy limitations and accelerate the renewable energy transition.
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