<p>  </p> <p>Plastics are the most common polymers used in various industries. However, million tons of plastics are produced and disposed every year around the world, and part of them end up entering the environment and agricultural ecosystems in the form of microplastics. Microplastics have become an environmental and health threat to aquatic species and humans because they are small and can easily reach water bodies for municipal and agricultural uses. Microplastics have been traced in food commodities and products derived from animals and even found in bottles of drinking water. As an approach to permanently remediating microplastics, current microplastic degradation techniques, however, require high energy inputs and thus are generally not cost-efficient. High-voltage atmospheric cold plasma (HVACP) is a low-cost energy-efficient technology to produce highly reactive species that can induce physicochemical changes in polymers. This study, for the first time, used HVACP as a novel remediation strategy for microplastics. HVACP was generated by dielectric barrier discharge at 50 kV using oxygen, nitrogen, or their mixture as working gas. Two types of microplastics, polypropylene (PP) and low-density polyethylene (LDPE), were treated for 30 min, and the effect of 24-h post-treatment was also studied. The properties of HVACP-treated microplastics, including weight, particle size, crystallinity, melting point, carbonyl index (CI), and surface morphology, were comprehensively analyzed. HVACP treatments were found effective in degrading both PP and LDPE microplastics. A larger extent of degradation was observed with PP microplastics treated by O/N mixture plasma, but the nitrogen plasma-treated sample showed a higher degree of oxidation according to its CI. For PE microplastics, oxygen plasma caused more degradation, but post-treatment did not promote further oxidation. The results indicated two potential mechanisms for microplastic degradation by HVACP. LDPE microplastics were degraded by oxidative reactions caused by highly reactive oxygen species, and PP microplastics followed a hydrolytic pathway of degradation as they became more hydrophilic after HVACP treatment. This study proved that HVACP is a promising method for microplastic degradation, and thus has great potential for addressing the severe challenges of microplastics that the food and agriculture sectors are currently facing.</p>

<p>  </p> <p>The integration of Industry 4.0 technologies such as cyber-physical systems, the internet of things, and artificial intelligence has revolutionized the traditional manufacturing systems, making them smart and digital. Maintenance, a critical component of manufacturing, has been incorporated with data-driven strategies such as prognostic and health management (PHM) to improve production efficiency and reliability. This is achieved by real-time sensing and AI-based modeling, which monitor the health condition of operational equipment for fault detection or failure prediction. The results generated by these models provide crucial support for decision-making processes in manufacturing, ranging from maintenance scheduling to production management.</p> <p>This research focuses on data-driven machine health models based on deep learning in manufacturing systems and explores three directions towards the practical implementation of PHM: model interpretation, model adaptability and robustness enhancement, and cost-benefit analysis of maintenance strategies. In terms of model interpretation, the RNN-LSTM-based model prediction on bearing health estimation was analyzed, and the relationship between the model input and output was investigated. The adoption of the LRP technique improved the explainability of the LSTM model beyond predictive maintenance applications. To enhance model adaptability and robustness, a Transformer-based method was developed for fault diagnosis and novel fault detection, which achieved superior performance compared to conventional fault classification AI-based models. The decision-making aspect of PHM was addressed by conducting a cost-benefit analysis on different maintenance strategies, which provided a new perspective for decision-makers in maintenance management.</p>

Commercial video games have a great potential in battling the ongoing environmental crises. However, literature has so far largely neglected a connection between environmental sustainability and commercial video games. Therefore, this thesis analyses environmental sustainability incorporations in commercial video games by conducting a case study on Horizon Forbidden West (HFW). This case study is executed with help of an originally developed analytical model called Dimensions of Environmentally Sustainable Gameplay. The case study concludes that HFW especially excels in creating a realistic environmentally sustainable game world. Other dimensions of environmentally sustainable gameplay such as environmental objects, agents and events, need more improvement. HFW shows problematic incorporation of video game objects as it is merely based on mastering the environment in the form of resource extraction. The research findings indicate that HFW’s producers have not yet uncovered the medium’s full potential. This thesis encourages further research into environmental sustainability in commercial video games and provides commercial video game producers with the necessary tools to create future games with improved environmental considerations.

<p dir="ltr">Improving environmental sustainability in energy production and waste management are of critical importance. Anaerobic digestion (AD) uses microbes to biologically decompose organic waste and produce biogas, which can be used for various forms of sustainable energy. It can be particularly valuable for livestock facilities considering AD of their manure, and potentially other feedstocks as well, a process known as co-digestion. Improved understanding of co-digestion of agro-industrial feedstocks is critical for these facilities. Understanding the macromolecular composition (carbohydrate, protein, and lipid portions) of potential AD feedstocks has the potential to provide important information for predicting important parameters of AD behavior. However, the stability of these macromolecules in AD samples during long-term storage must be confirmed. Furthermore, synergistic and antagonistic impacts of co-digestion on methane production and digestate composition need to be more thoroughly explored.</p><p dir="ltr">This dissertation investigates the impact of storage at refrigeration temperatures (4°C) for up to one-year on the macromolecular composition of various agro-industrial feedstocks (beef manure, starch, slaughterhouse waste, soap stock, and filter press slurry) and anaerobic co-digestion samples. These same feedstocks were co-digested with manure in batch digesters at different proportions, using two or three feedstocks to determine possible synergistic effects.</p><p dir="ltr">The findings show that minimal macromolecular degradation occurred in AD samples during storage at refrigeration temperatures for up to one-year. A major exception was samples containing high concentrations of readily biodegradable starches, which did experience >50% carbohydrate degradation. This indicates a need for methodological rigor during sample storage and reporting experimental design.</p><p dir="ltr">Furthermore, the co-digestion experiments demonstrated frequent improvements or synergy in specific methane yield, methane production rate, and a wide variety of physical and chemical parameters in the digester effluent. Specific methane yield was shown to be at least additive, with improvement ranging from 3-168%. Some improvements in kinetic performance were also observed and quantified. Statistical results suggest that influent characteristics could be useful as predictors for methane production. This research could catalyze additional work needed to optimize co-digestion feeding strategies for full-scale digesters.</p>

<p>Biodegradation of untreated cotton, linen, and hemp textiles as three substrates – measured through biogas production – was studied to compare digestion yield and the ability of anaerobic sludge as inoculum to utilize the sugars in these textiles without pretreatment. Digestion of these textile substrates was carried out over a 26-day study, with daily sampling of biogas production, to measure biogas production rate and accumulation. The flasks were maintained at 37 °C and 150 RPM with a substrate to inoculum ratio (SIR) of 0.5 g sugars from substrate g-1 VSinoculum from anaerobic sludge. Biogas samples were analyzed through gas chromatography (GC) to determine general biogas composition produced by each textile. Biogas production was notable after the four-day mark; with first peaks occurring on day five (hemp, cellulose), day seven (cotton), and day nine (linen). Production of biogas in the control largely outperformed trials with no added substrate, but overall the methane fractions of the gas was lower than expected, indicating that pretreatment is likely necessary for more complete biodegradation of natural textiles. </p>

Im Rahmen der Gemeinsamen Agrarpolitik der Europäischen Union wurden Agrarumweltprogramme (AES) entwickelt, um die durch die Landwirtschaft verursachte Zerstörung der natürlichen Umwelt zu bekämpfen. Um die ökologische Wirksamkeit der Systeme zu verbessern, wird ein kollektiver Ansatz empfohlen, der sich auf eine Landschaft statt auf eine einzelne Betriebsebene konzentriert. Dieser Ansatz wird in ganz Europa selten angewendet, außer in den Niederlanden, wo seit 2016 alle AES gemeinsam realisiert werden müssen. Da die Teilnahme an den Programmen freiwillig ist, ist es von entscheidender Bedeutung, die Motivation der Landwirte zu verstehen, sich anzuschließen, da die Annahme und Umsetzung von Maßnahmen eine Voraussetzung für die Erreichung ist irgendwelche Effekte. Ziel dieser Studie ist es daher, die Motivation niederländischer Landwirte zur Teilnahme an kollektiven AES zu untersuchen und die wichtigsten Vor- und Nachteile des Programms herauszufinden, die von den Landwirten wahrgenommen werden. Eine Q-Studie mit 15 Landwirten aus sechs Provinzen zeigt drei vorherrschende Motivationsansichten: eine kollektivorientierte, eine wirtschaftsorientierte und eine umweltorientierte Perspektive. Alle Bauern eint ihre Zuneigung und Sorge für die Natur, die von unterschiedlichem Problembewusstsein und Kollektivzugehörigkeit begleitet wird. Finanzieller Ausgleich wird von allen als wichtig erachtet, jedoch eher als notwendiges Mittel, um notwendige Änderungen in der landwirtschaftlichen Praxis zu ermöglichen, denn als zusätzliche Einnahmequelle. Während die niederländischen Regelungen noch weiter verbessert werden können, um mehr Flexibilität, eine bessere Integration des Wissens der Landwirte und eine bessere Kommunikation zu ermöglichen, weisen alle Landwirte viele Vorbehalte im Zusammenhang mit kollektiven Maßnahmen zurück, was darauf hindeutet, dass der niederländische Ansatz über die nationalen Grenzen hinaus gefördert werden könnte. / Within the European Union’s Common Agricultural Policy, agri-environment schemes (AES) have been designed to address the degradation of the natural environment caused by agriculture. To improve the schemes’ ecological effectiveness, a collective approach focusing on a landscape instead of a single farm level is recommended. This approach is rarely applied across Europe except for the Netherlands, where all AES have to be realised collectively since 2016. As participation in the schemes is voluntary, understanding farmers’ motivation to join is crucial since the uptake and implementation of measures is prerequisite for achieving any effects. Hence, the aim of this study is to explore Dutch farmers’ motivation to participate in collective AES and to find out about the scheme’s main advantages and disadvantages perceived by the farmers. A Q study with 15 farmers from six provinces shows three dominant motivational views: a collective-oriented, a business-oriented and an environment-oriented perspective. All farmers unites their affection and care for nature, which is accompanied by different levels of problem awareness and affiliation to the collective. Financial compensation is deemed important by all, yet rather as necessary mean to enable required changes in farming practices than as additional source of revenue. While the Dutch schemes can still be further improved to allow for more flexibility, a better integration of the farmers’ knowledge and enhanced communication, all farmers dismiss many caveats related to collective action, indicating a potential to promote the Dutch approach beyond national borders.

Klimatförändringarna påverkar Sverige med intensifierade nederbörds- och översvämningshändelser. Sverige har de senare åren utsatts för fler översvämningar, bland annat i Vänern år 2000/2001. Baserat på tidigare studier har översvämningen inom området för Vänern och Klarälven påvisat drabbat miljöfarliga verksamheter.  Syftet med denna uppsats är att undersöka hur översvämningsrisk uppfattas av representanter med ansvar kopplat till miljöfarlig verksamhet som befinner sig i riskzonen för Klarälvens och Vänerns höga flöden. Uppsatsen syftar även till att undersöka vilka omständigheter som påverkar representanternas riskuppfattning, om de uppfattar översvämning som en problematik i framtiden gentemot miljöfarliga verksamheter och hur de tre aktörerna samverkar med varandra. Uppsatsen baseras på grupp- och semistrukturerade intervjuer och kvalitativ innehållsanalys för att samla in och bearbeta data. Resultatet från metoderna diskuteras utifrån tidigare forskning inom området och ett teoretiskt ramverk baserat på riskuppfattning och Protection Motivation Theory [PMT].  Resultatet redovisar att uppfattningen av att en miljöfarlig verksamhet inom området ska drabbas av en översvämning är låg, vilket beror på att det krävs väldigt höga vattenflöden. Samverkan mellan parterna sker bland annat utifrån arbetet mot att minimera riskerna att drabbas av översvämningar. Risken kan dock inte uteslutas helt på grund av osäkerheten i klimatförändringarna. För att motverka översvämningsriskerna i framtiden arbetar aktörerna huvudsakligen med att reducera koldioxidutsläpp för att minska påverkan på klimatförändringarna. / Climate change is affecting Sweden with intensified rainfall and flooding events. In recent years, Sweden has been exposed to more floods, including in Lake Vänern in 2000/2001. Based on previous studies, the flooding in the Vänern and Klarälven area has affected environmentally hazardous activities.   The purpose of this essay is to investigate how flood risk is perceived by representatives with responsibilities linked to environmentally hazardous activities who are in the risk zone for the high flows of the Klarälven and Vänern rivers. The essay also aims to investigate which circumstances affect the representatives' perception of risk, if they perceive flooding as a problem in the future compared to environmentally hazardous activities and how the three actors cooperate with each other. The essay is based on group and semi-structured interviews and qualitative content analysis to collect and process data. The results from the methods are discussed based on previous research in the field and a theoretical framework based on risk perception and Protection Motivation Theory [PMT].   The results show that the perception that an environmentally hazardous activity in the area will be affected by a flood is low, which is due to the fact that very high water flows are required. Cooperation between the parties takes place, among other things, based on the work towards minimizing the risks of being affected by floods. However, the risk cannot be completely ruled out due to the uncertainty of climate change. In order to counteract the flood risks in the future, the actors mainly work to reduce carbon dioxide emissions in order to reduce the impact on climate change.

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<p>Biomass liquefaction is a nascent field within biorefinery research and has arisen in response to the bottleneck created from materials handling at the front end of the biorefinery. The basic concept is that if the biomass were to be converted into a flowable slurry at the front-end of the process, then the material could smoothly flow into the biorefinery pretreatment and down time due to the material forming a plug would be minimized or eliminated. Three liquefaction routes were studied in this work. These routes were: enzyme route, enzyme mimetic route, and a combined route of enzyme and enzyme mimetic. Through a Techno-economic assessment (TEA), it is possible to determine which route is most-economical to scale up and also to understand the extent to which liquefaction increases/decreases of the price of the biorefinery product.</p> <p>Gasification is a bio-based technology that has recently acquired more attention as it is an efficient conversion process for a variety of feedstocks. As new techniques and process routes are discovered, it is important to analyze which process technique is feasible for commercial scale up, as the highest performing technique may not be the most economical option to pursue. Along the same philosophy, a process concept was developed on Aspen Plus® to treat syn-gas impurities and also recycle the spent solvents. A TEA study was performed to determine the unit cost of treatment and to explore avenues of cost saving.</p>

[pt] A literatura apresenta lacunas em relação a antecedentes que levam consumidores a comprar produtos de marcas ecologicamente responsáveis. Esta tese propõe um modelo integrando estímulos de naturezas cognitiva, afetiva e normativa e seus impactos na intenção de compra de produtos de tais marcas. Conduziu-se um survey sobre amostra de consumidores que conhecem marcas que se preocupam com preservação ambiental, obtendo-se 419 respostas válidas. Os dados foram submetidos à análise por modelagem por equações estruturais. Os resultados mostraram relações significativas entre estímulos (cognitivos e afetivos) e a atitude em relação a comprar produtos de marcas que se preocupam com a preservação ambiental. A auto eficácia, quando antecede a atitude, também teve efeito significativo e direto sobre a atitude. / [en] This study addresses a gap in literature with respect to antecedents that lead consumers to buy products from ecologically concerned brands. This study proposes a model integrating cognitive, affective and normative drivers and their impacts on the purchase intention of products of such brands. The central hypothesis of this study is that the consumer s attitude towards buying these products has cognitive and affective antecedents and that self-efficacy precedes the intention to buy products from brands that are concerned with environmental preservation. A survey was conducted on a sample of consumers who know brands that care about environmental preservation, obtaining 419 valid answers. The data were submitted to analysis by structural equation modeling (SEM). The results showed significant relationships between cognitive and affective drivers and the attitude towards buying products from ecologically concerned brands. Self-efficacy, when it precedes the attitude, also has a significant and direct effect on the attitude.