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A Mixed Method Approach to Understanding Team Members' Perspectives After Receiving Problem-Solving Training and Performance FeedbackJulian, Alexander Mark 05 July 2022 (has links)
While countless studies have collected data on the effectiveness of various problem- solving models, few have attempted to identify which components of the training process are helpful to participants. Two teacher teams consisting of seven participants were trained in an adapted version of the Team-initiated Problem Solving (TIPS) model, observed each meeting, and provided performance feedback regarding how well they had adhered to the model. A mixed method approach was used to collect quantitative data in the form of the teams' adherence to the TIPS model and qualitative data once successful adherence to the model had been shown. Researchers interviewed each participant and used some strategies from the critical incident technique (CIT) to identify which components the training and performance feedback process were helpful, unhelpful, and which components they wished had been there that weren't. Themes among incidents reported as helpful were the expectation of meeting in professional learning community (PLC) teams to solve problems and consistent feedback on how closely they were adhering to the model. Unhelpful and wish list incidents included the difficult to use problem- solving form, structural components of meetings and training, and a desire to have more participants in meetings, particularly ones from other grades. Researchers and administrators who are looking to train teams with the TIPS model are recommended to use consistent performance feedback, include participants in the planning of the study, and have more question- and-answer style mini-trainings spaced throughout the observation phase. Lastly, two alternate problem-solving forms are presented as options to be used in place of the current meeting minutes form provided by the TIPS model. Both alternate versions aim to retain the components of the model, but with increased usability.
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Analysis of a nonhierarchical decomposition algorithmShankar, Jayashree 19 September 2009 (has links)
Large scale optimization problems are tractable only if they are somehow decomposed. Hierarchical decompositions are inappropriate for some types of problems and do not parallelize well. Sobieszczanski-Sobieski has proposed a nonhierarchical decomposition strategy for nonlinear constrained optimization that is naturally parallel. Despite some successes on engineering problems, the algorithm as originally proposed fails on simple two dimensional quadratic programs.
Here, the algorithm is carefully analyzed by testing it on simple quadratic programs, thereby recognizing the problems with the algorithm. Different modifications are made to improve its robustness and the best version is tested on a larger dimensional example. Some of the changes made are very fundamental, affecting the updating of the various tuning parameters present in the original algorithm.
The algorithm involves solving a given problem by dividing it into subproblems and a final coordination phase. The results indicate good success with small problems. On testing it with a larger dimensional example, it was discovered that there is a basic flaw in the coordination phase which needs to be rectified. / Master of Science
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MULTIMODAL SPATIAL-TEMPORAL DATA FUSION TECHNIQUES FOR ENHANCING FIELD CROP BIOMASS ESTIMATION IN PRECISION AGRICULTUREKevin Tae Sup Lee (18824575) 17 June 2024 (has links)
<p dir="ltr">This study introduces a methodology wherein daily values are linearly interpolated to achieve uniform temporal resolution across various data sets, including spectral and environmental information. This approach facilitates further analysis using machine learning techniques to estimate biomass. The proposed Best Friend Frame (B.F.F.) data set integrates Unmanned Aerial Systems (UAS) data, weather data, weather indices, soil hydrological group classifications, and topographic information. Two different biomass estimations were created to enhance versatility: one averaged per management practice and another averaged per physical experimental plot size. Additionally, SuperDove satellite data were combined with identical environmental data as that of the UAS.</p><p dir="ltr">UAS flights were conducted at the ACRE field in 2022 and 2023. The UAS data were captured at a height of 30 meters, yielding a ground sample distance of 2 cm/pixel per flight. Satellite data were sourced from the Planet SuperDove product. The images were processed using Crop Image Extraction (CIE) and calibrated with Vegetation Index Derivation (VID). Spatial resolution was defined as the experimental plot size per year per crop type (soybean or corn). Topographic data were derived from Indiana LiDAR data, and soil information was obtained from the USDA SSURGO dataset.</p><p dir="ltr">The B.F.F. framework can be utilized with various models to identify which environmental inputs influence biomass accumulation throughout the growing season.</p>
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Quantifying scribal behavior : a novel approach to digital paleographySampath, Vinodh Rajan January 2016 (has links)
We propose a novel approach for analyzing scribal behavior quantitatively using information about the handwriting of characters. To implement this approach, we develop a computational framework that recovers this information and decomposes the characters into primitives (called strokes) to create a hierarchically structured representation. We then propose a number of intuitive metrics quantifying various facets of scribal behavior, which are derived from the recovered information and character structure. We further propose the use of techniques modeling the generation of handwriting to directly study the changes in writing behavior. We then present a case study in which we use our framework and metrics to analyze the development of four major Indic scripts. We show that our framework and metrics coupled with appropriate statistical methods can provide great insight into scribal behavior by discovering specific trends and phenomena with quantitative methods. We also illustrate the use of handwriting modeling techniques in this context to study the divergence of the Brahmi script into two daughter scripts. We conduct a user study with domain experts to evaluate our framework and salient results from the case study, and we elaborate on the results of this evaluation. Finally, we present our conclusions and discuss the limitations of our research along with future work that needs to be done.
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Enskilda avloppsanläggningar med fosforbindning i Stockholms län : en miljösystemanalys med metodik från livscykelanalys / Phosphorus sorbing small-scale wastewater treatment plants in the county of Stockholm : an environmental systems analysis using life cycle assessment methodologyWeiss, Philipp January 2007 (has links)
<p>Modern, small-scale wastewater treatment faces a twofold challenge: On the one hand requirements from legal authorities regarding removal of eutrophying substances have become more demanding. On the other hand high-quality phosphorus reserves are dwindling, which has raised calls for increased recycling. The problem is acute in the county of Stockholm where about 34 000 households are identified to not possess adequate wastewater treatment facilities. In this master’s thesis, four treatment systems, of which three had some phosphorus recycling potential, were compared using life cycle assessment methodology. The small-scale treatment systems analyzed were infiltration, filter beds with Filtralite® P and Filtra P respectively as filter material and a chemical precipitation system. The system boundaries included the extraction of raw materials, production of materials and components, the construction and operation of the systems as well as deconstruction and recycling of the treatment plants. Apart from impacts on human health and acidification potential, which both proved to be of less relevance to the final results, energy usage, consumption of abiotic resources, global warming potential and eutrophication potential were taken into account in this study.</p><p>The infiltration system attained the most favourable results in all impact categories save eutrophication potential, which was due to both the low usage of energy and resources as well as the system’s high life expectancy. The filter bed system using Filtralite® P demonstrated the best performance in reduction of eutrophying substances. However, the system’s energy demand and emissions of greenhouse gases by far exceeded the other systems’ results in these categories. Both the filter bed system using Filtra P and the chemical precipitation system fared relatively equal in the overall analysis, with moderate impacts in all categories. The nutrient recycling potential was shown to be limited by the waste products’ relatively high heavy metal content. Sludge from chemical precipitation had higher potential for replacement of fertilizer than filter bed material.</p><p>The chemical precipitation system fared best in the overall assessment. Its technical immaturity and limited data foundation put the alternative using Filtra P into second place. The infiltration system’s limited treatment performance and inexistent recycling potential put this alternative into third place. The alternative using Filtralite® P was ruled out entirely because of its high impact on fossil fuel consumption and global warming. Based on this ranking recommendations were made.</p><p>Even though the filter bed materials in this study showed excellent phosphorus removal capacity, further research into alternative filter bed materials will have to be made due to the materials’ environmental impacts in other areas. Focus should be on waste material and natural products (such as shell sand) with low environmental impacts from production. Ways of separating heavy metals from plant nutrients need to be explored if nutrient recycling is to be an aim. This study showed that good phosphorus removal characteristics can lead to an increase in other environmental impacts, which in some cases even may outweigh the positive effects of decreased eutrophication.</p> / <p>Modern, småskalig avloppsreningsteknik står inför två utmaningar. Å ena sidan har kraven från lagstiftaren på rening av eutrofierande ämnen ökat. Problemet är akut i Stockholms län där det finns ca. 34 000 hushåll som inte anses uppfylla reningskraven. Å andra sidan minskar fosforförekomsterna av hög kvalitet i allt större takt, vilket har väckt krav på ökad återföring av växtnäring. I detta examensarbete undersöktes fyra olika reningstekniker, varav tre har en viss återföringspotential, med hjälp av metodik från livscykelanalys. Systemen som undersöktes var infiltration, filterbäddar dels med Filtralite® P och dels med Filtra P som filtermaterial, samt ett kemikaliefällningssystem. Systemgränserna omfattade extraktion av råmaterial, produktion av anläggningsmaterial och –komponenter, uppförande och drift av systemen samt avveckling av anläggningarna och återföring av restmaterial. Förutom påverkan på mänsklig hälsa och försurningspotential, som visade sig vara mindre relevanta för slutresultaten, omfattade analysen även en undersökning av energianvändning, förbrukning av abiotiska resurser, potential för global uppvärmning och eutrofieringspotential.</p><p>Infiltrationslösningen fick de mest fördelaktiga resultatvärden i alla kategorierna förutom eutrofieringspotential, vilket kan förklaras med systemets låga energi- och resursbehov samt dess höga livslängd. Filterbädden med Filtralite® P som filtermaterial uppvisade den största förmågan att reducera eutrofierande substanser. Systemets energibehov och utsläpp av växthusgaser översteg dock de andra systemens resultat i dessa kategorier kraftigt. Både anläggningen med Filtra P och kemikaliefällningslösningen fick liknande resultat, med måttlig påverkan i alla kategorier. Systemens återföringspotential visade sig vara begränsad av restprodukternas höga tungmetallhalt. Kemikaliefällt slam hade högre återföringspotential än filterbäddsmaterial.</p><p>Kemikaliefällning klarade sig totalt sett bäst i studien. Den relativt obeprövade tekniska utformning och det osäkra dataunderlaget ledde till att Filtra P hamnade i rangordningen efter kemikaliefällning. Infiltrationssystemets begränsade reningsförmåga och den obefintliga återföringspotentialen ledde till att alternativet hamnade näst sist. Filtralite® P-alternativet blev placerat sist i rangordningen på grund av dess stora påverkan på förbrukning av fossila bränslen och global uppvärmning. Baserat på rangordningen utfärdades rekommendationer.</p><p>Trots att filtermaterialen som undersöktes i denna studie har en utmärkt fosforreningsförmåga, kommer det att krävas fler studier med avseende på alternativa filtermaterial, eftersom materialens användning av icke-förnybara energikällor är mycket stor vid tillverkningen. Fokus borde ligga på återvunna eller naturliga material (som t.ex. snäcksand) med låg miljöpåverkan vid tillverkning. Om återföring av växtnäring ska bli ett mål inom småskalig avloppsvattenrening, måste effektiva sätt att separera tungmetaller från växtnäringsämnen utforskas. Denna studie visade att goda fosforavskiljningsegenskaper kan medföra att andra typer av miljöpåverkan ökar, vilket i vissa fall kan leda till att de negativa konsekvenserna överväger nyttan av minskad eutrofiering.</p> / <p>Moderne, dezentrale Abwassertechnik steht zwei großen Herausforderungen gegenüber. Zum einen sind die Ansprüche von Seiten des Gesetzgebers gestiegen, die effektivere Abwasserreinigungstechniken erfordern. Zum andern werden Phosphorvorkommen von hoher Qualität zunehmend knapper, was Rufe nach verstärkter Rückführung von Phosphor hat laut werden lassen. Im Verwaltungsbezirk Stockholm, in dem es ungefähr 34 000 Haushalte mit unzureichender Abwasserreinigung gibt, ist das Problem von besonderer Bedeutung. In dieser Diplomarbeit wurden vier Abwasserreinigungssysteme, wovon drei ein gewisses Potential für Phosphorrückführung haben, mit Hilfe einer Ökobilanzierung untersucht. Folgende Systeme wurden untersucht: Eine Infiltrationsanlage, zwei Filterbettsanlagen, eine mit Filtralite® P und eine mit Filtra P als Filtermaterial sowie ein System mit Chemikaliefällung. Die Systemgrenzen umfassten die Gewinnung und Verarbeitung von Rohstoffen, das Errichten der jeweiligen Anlage, deren Betrieb sowie Rückgewinnung und Entsorgung von Restmaterialien. Neben Auswirkungen auf die menschliche Gesundheit und Versauerungspotential, die sich im Nachhinein als weniger relevant erwiesen, wurden Energiebedarf, Verbrauch abiotischer Resourcen, Potential für globale Erwärmung und Eutrophierungspotential untersucht.</p><p>Die niedrigsten Resultate in allen Kategorien außer Eutrophierungspotential wurden vom Infiltrationssystem erreicht. Filtralite® P erwies sich als am leistungsstärksten, was die Reduktion von eutrophierenden Substanzen angeht. Der Energiebedarf und die Emissionen von Treibhausgasen dieser Alternative überstieg die Ergebnisse der anderen Alternativen in diesen Kategorien doch bei weitem. Filtra P und Chemikaliefällung erzielten moderate Auswirkungen in allen Kategorien. Das Potential für die Rückführung von Pflanzennährstoffen wird, wie die Ergebnisse zeigen, vom relativ hohen Schwermetallhalt in den Restprodukten begrenzt.</p><p>Chemikaliefällung ist in dieser Studie die beste Alternative. Filtra P zeigte sich als technisch noch zu wenig ausgereift und die Datenunterlage als zu unvollständig, weswegen diese Alternative an zweiter Stelle steht. Die begrenzte Reinigungsfähigkeit des Infiltrationssystemes und das nicht vorhandene Potential für Rückführung von Phosphor führten dazu, dass diese Lösung an dritter Stelle steht. Das System mit Filtralite® P als Filtermaterial wurde wegen seines großen Verbrauchs von fossilen Brennstoffen für wenig brauchbar befunden und steht damit an letzter Stelle.</p><p>Trotz ihrer hervorragenden phosphorreduzierenden Eigenschaften, wird weitere Forschung im Bereich alternativer Filtermaterialien notwendig werden. Hierbei sollten natürliche Materialien (wie Muschelsand) oder Restprodukte im Mittelpunkt des Interesses stehen, um die Umweltauswirkungen gering zu halten. Wenn die Rückführung von Phosphor ein Ziel der Abwasserreinigung sein soll, müssen Lösungen, Schwermetalle von Pflanzennährstoffen zu trennen, gefunden werden. Diese Studie hat gezeigt, dass gute phosphorreduzierende Eigenschaften zu verstärkten Umweltauswirkungen in anderen Bereichen führen können, welche in manchen Fällen sogar die Vorteile einer verringerten Eutrophierung übersteigen können.</p>
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Biomass Potential for Heat, Electricity and Vehicle Fuel in SwedenHagström, Peter January 2006 (has links)
The main objective of this thesis was to determine how far a biomass quantity, equal to the potential produced within the Swedish borders, could cover the present energy needs inSwedenwith respect to economic and ecological circumstances. Three scenarios were studied where the available biomass was converted to heat, electricity and vehicle fuel. Three different amounts of biomass supply were studied for each scenario: 1) potential biomass amounts derived from forestry, non-forest land, forest industry and community; 2) the same amounts as in Case 1, plus the potential biomass amounts derived from agriculture; 3) the same amounts as in Case 1, plus 50% of the potential pulpwood quantity. For evaluating the economic and ecological circumstances of using biomass in the Swedish energy system, the scenarios were complemented with energy, cost and emergy analysis. The scenarios indicated that it may be possible to produce 170.2 PJ (47.3 TWh) per year of electricity from the biomass amounts in Case 2. From the same amount of biomass, the maximum annual production of hydrogen was 241.5 PJ (67.1 TWh) per year or 197.2 PJ (54.8 TWh) per year of methanol. The energy analysis showed that the ratio of energy output to energy input for large-scale applications ranged from 1.9 at electric power generation by gasification of straw to 40 at district heating generation by combustion of recovered wood. The cost of electricity at gasification ranged from 7.95 to 22.58 €/GJ. The cost of vehicle work generated by using hydrogen produced from forestry biomass in novel fuel cells was economically competitive compared to today’s propulsion systems. However, the cost of vehicle work generated by using methanol produced from forestry biomass in combustion engines was rather higher compared to use of petrol in petrol engines. The emergy analysis indicated that the only biomass assortment studied with a larger emergy flow from the local environment, in relation to the emergy flow invested from society after conversion, was fuel wood from non-forest land. However, even use of this biomass assortment for production of heat, electricity or vehicle fuels had smaller yields of emergy output in relation to emergy invested from society compared to alternative conversion processes; thus, the net contribution of emergy generated to the economy was smaller compared to these alternative conversion processes. / <p>QC 20120217</p>
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Att hitta akilleshälen : sårbarhetsanalyser till stöd för militär planering / Finding the Achilles’ heel : vulnerability analyses in support of military planningMagnét, Erik January 2018 (has links)
Enligt gällande västliga militära planeringsdoktriner, inklusive den svenska som den formuleras i Svensk planerings och ledningsmetod (SPL), är tyngdpunktsanalyser av såväl motståndaren som den egna sidan avgörande steg i planeringsprocesserna på både strategisk och operativ nivå. Tyngdpunkten kan anfallas eller påverkas direkt eller indirekt, i det ideala fallet genom att slå mot kritiska sårbarheter. Kritiska sårbarheter kan ofta vara av teknisk karaktär, vilket historiska erfarenheter visar. Bristande teknisk förståelse riskerar därmed leda till att kritiska sårbarheter hos fienden inte exploateras och att våra egna inte skyddas. De nyckelfaktorer som bygger upp tyngdpunkten ska enligt doktrinerna identifieras genom systemanalys. Beskrivningarna av vad en systemanalys är eller hur denna kan genomföras saknar dock både tillräckligt djup och tydlighet för att kunna användas praktiskt och ge önskad kvalitet. Detta riskerar att ge stora konsekvenser för den fortsatta planeringen. I uppsatsen föreslås en utvecklad metod för tyngdpunktsanalys, med fokus på hur de kritiska sårbarheterna identifieras och värderas. Metodens huvudsakliga moment är modellering och klassificering, där klassificeringsmomentet sker med en föreslagen metod som hämtat stöd från såväl verkansprocessen som civil forskning om systemsårbarheter. Metoden operationaliseras i uppsatsen och prövas i en fallstudie med två fall. Slutsatserna från undersökningen indikerar att den föreslagna metoden är användbar och har förklaringskraft i de undersökta fallen. För att analysen av kritiska sårbarheter ska nå tillräcklig kvalitet krävs djupa systemkunskaper och inte minst resurser i form av personal och tid. Den föreslagna metoden behöver prövas i sin helhet för att utvärdera den praktiska användbarheten. / According to contemporary western military doctrines, and Swedish doctrine is no exception, analyses of the centers of gravity of enemy and friendly forces are vital steps in the planning process at the strategic and operational levels of war. Centers of gravity might be attacked or influenced directly or indirectly, ideally by targeting critical vulnerabilities. Critical vulnerabilities are often of a technical nature, as shown by historical experience. A lack of technical understanding might lead to enemy vulnerabilities not being exploited and our own not being adequately protected. According to doctrine, a center of gravity’s key factors should be identified through systems analysis of enemy and friendly forces. However, descriptions of what these analyses are, or how they should be conducted, lack sufficient depth and clarity to be used in practice and provide sufficient quality. This is likely to have negative consequences for continued planning. This thesis proposes a developed method for center of gravity analysis, focusing on the identification and evaluation of critical vulnerabilities. The main elements of the method are modeling and classification, where the classification is conducted using a proposed method, supported by a method within the targeting process, and by civilian research into system vulnerabilities. The full method is operationalized in the thesis and tested in a two-case study. The conclusions from the study indicate that the proposed method is usable and has explanatory value in the cases studied. To achieve sufficient quality in the analysis of critical vulnerabilities, in-depth systems knowledge and, not least, resources in terms of staff and time are required. The proposed method needs to be tested in its entirety to evaluate its practical usability.
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The Impact of African-Centered Psychotherapy on Depressive Symptoms and Africentric Worldview in African AmericansTillis, LaRae 01 January 2016 (has links)
Depression is a prominent issue in the African American community. However, there are significant gaps in the literature on the delivery and outcomes of culturally relevant mental health psychotherapy to African Americans. Cultural variables, such as worldview, have been noted to impact an individual's overall psychosocial functioning and have significant implications for mental health service delivery. The purpose of this study was to use archival data to analyze the impact of African-centered therapeutic services on depressive symptoms and on Africentric worldview among African Americans. Archival data on 38 African American adults, recorded from 2012-2015, were obtained from a community mental health agency in the Midwest. Each of the adults received therapy via an African-centered treatment modality. The study was grounded in the cognitive theory of depression and optimal theory. The dependent treatment outcome variables were (a) depressive symptomology, as measured with the depression subscale of the Symptom Checklist-90-Revised and (b) Africentric worldview as measured by the Belief Systems Analysis Scale. The dependent variables were measured twice: once in the beginning and once at the end of a year's treatment. A dependent, paired t tests indicated a significant reduction in depressive symptoms but no significant increase in adherence to Africentric worldview. This study has implications for positive social change by: providing increased insight on the need for culturally relevant services to African Americans, which can subsequently lead to culturally relevant social change in the delivery of mental health services to diverse populations.
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Enskilda avloppsanläggningar med fosforbindning i Stockholms län : en miljösystemanalys med metodik från livscykelanalys / Phosphorus sorbing small-scale wastewater treatment plants in the county of Stockholm : an environmental systems analysis using life cycle assessment methodologyWeiss, Philipp January 2007 (has links)
Modern, small-scale wastewater treatment faces a twofold challenge: On the one hand requirements from legal authorities regarding removal of eutrophying substances have become more demanding. On the other hand high-quality phosphorus reserves are dwindling, which has raised calls for increased recycling. The problem is acute in the county of Stockholm where about 34 000 households are identified to not possess adequate wastewater treatment facilities. In this master’s thesis, four treatment systems, of which three had some phosphorus recycling potential, were compared using life cycle assessment methodology. The small-scale treatment systems analyzed were infiltration, filter beds with Filtralite® P and Filtra P respectively as filter material and a chemical precipitation system. The system boundaries included the extraction of raw materials, production of materials and components, the construction and operation of the systems as well as deconstruction and recycling of the treatment plants. Apart from impacts on human health and acidification potential, which both proved to be of less relevance to the final results, energy usage, consumption of abiotic resources, global warming potential and eutrophication potential were taken into account in this study. The infiltration system attained the most favourable results in all impact categories save eutrophication potential, which was due to both the low usage of energy and resources as well as the system’s high life expectancy. The filter bed system using Filtralite® P demonstrated the best performance in reduction of eutrophying substances. However, the system’s energy demand and emissions of greenhouse gases by far exceeded the other systems’ results in these categories. Both the filter bed system using Filtra P and the chemical precipitation system fared relatively equal in the overall analysis, with moderate impacts in all categories. The nutrient recycling potential was shown to be limited by the waste products’ relatively high heavy metal content. Sludge from chemical precipitation had higher potential for replacement of fertilizer than filter bed material. The chemical precipitation system fared best in the overall assessment. Its technical immaturity and limited data foundation put the alternative using Filtra P into second place. The infiltration system’s limited treatment performance and inexistent recycling potential put this alternative into third place. The alternative using Filtralite® P was ruled out entirely because of its high impact on fossil fuel consumption and global warming. Based on this ranking recommendations were made. Even though the filter bed materials in this study showed excellent phosphorus removal capacity, further research into alternative filter bed materials will have to be made due to the materials’ environmental impacts in other areas. Focus should be on waste material and natural products (such as shell sand) with low environmental impacts from production. Ways of separating heavy metals from plant nutrients need to be explored if nutrient recycling is to be an aim. This study showed that good phosphorus removal characteristics can lead to an increase in other environmental impacts, which in some cases even may outweigh the positive effects of decreased eutrophication. / Modern, småskalig avloppsreningsteknik står inför två utmaningar. Å ena sidan har kraven från lagstiftaren på rening av eutrofierande ämnen ökat. Problemet är akut i Stockholms län där det finns ca. 34 000 hushåll som inte anses uppfylla reningskraven. Å andra sidan minskar fosforförekomsterna av hög kvalitet i allt större takt, vilket har väckt krav på ökad återföring av växtnäring. I detta examensarbete undersöktes fyra olika reningstekniker, varav tre har en viss återföringspotential, med hjälp av metodik från livscykelanalys. Systemen som undersöktes var infiltration, filterbäddar dels med Filtralite® P och dels med Filtra P som filtermaterial, samt ett kemikaliefällningssystem. Systemgränserna omfattade extraktion av råmaterial, produktion av anläggningsmaterial och –komponenter, uppförande och drift av systemen samt avveckling av anläggningarna och återföring av restmaterial. Förutom påverkan på mänsklig hälsa och försurningspotential, som visade sig vara mindre relevanta för slutresultaten, omfattade analysen även en undersökning av energianvändning, förbrukning av abiotiska resurser, potential för global uppvärmning och eutrofieringspotential. Infiltrationslösningen fick de mest fördelaktiga resultatvärden i alla kategorierna förutom eutrofieringspotential, vilket kan förklaras med systemets låga energi- och resursbehov samt dess höga livslängd. Filterbädden med Filtralite® P som filtermaterial uppvisade den största förmågan att reducera eutrofierande substanser. Systemets energibehov och utsläpp av växthusgaser översteg dock de andra systemens resultat i dessa kategorier kraftigt. Både anläggningen med Filtra P och kemikaliefällningslösningen fick liknande resultat, med måttlig påverkan i alla kategorier. Systemens återföringspotential visade sig vara begränsad av restprodukternas höga tungmetallhalt. Kemikaliefällt slam hade högre återföringspotential än filterbäddsmaterial. Kemikaliefällning klarade sig totalt sett bäst i studien. Den relativt obeprövade tekniska utformning och det osäkra dataunderlaget ledde till att Filtra P hamnade i rangordningen efter kemikaliefällning. Infiltrationssystemets begränsade reningsförmåga och den obefintliga återföringspotentialen ledde till att alternativet hamnade näst sist. Filtralite® P-alternativet blev placerat sist i rangordningen på grund av dess stora påverkan på förbrukning av fossila bränslen och global uppvärmning. Baserat på rangordningen utfärdades rekommendationer. Trots att filtermaterialen som undersöktes i denna studie har en utmärkt fosforreningsförmåga, kommer det att krävas fler studier med avseende på alternativa filtermaterial, eftersom materialens användning av icke-förnybara energikällor är mycket stor vid tillverkningen. Fokus borde ligga på återvunna eller naturliga material (som t.ex. snäcksand) med låg miljöpåverkan vid tillverkning. Om återföring av växtnäring ska bli ett mål inom småskalig avloppsvattenrening, måste effektiva sätt att separera tungmetaller från växtnäringsämnen utforskas. Denna studie visade att goda fosforavskiljningsegenskaper kan medföra att andra typer av miljöpåverkan ökar, vilket i vissa fall kan leda till att de negativa konsekvenserna överväger nyttan av minskad eutrofiering. / Moderne, dezentrale Abwassertechnik steht zwei großen Herausforderungen gegenüber. Zum einen sind die Ansprüche von Seiten des Gesetzgebers gestiegen, die effektivere Abwasserreinigungstechniken erfordern. Zum andern werden Phosphorvorkommen von hoher Qualität zunehmend knapper, was Rufe nach verstärkter Rückführung von Phosphor hat laut werden lassen. Im Verwaltungsbezirk Stockholm, in dem es ungefähr 34 000 Haushalte mit unzureichender Abwasserreinigung gibt, ist das Problem von besonderer Bedeutung. In dieser Diplomarbeit wurden vier Abwasserreinigungssysteme, wovon drei ein gewisses Potential für Phosphorrückführung haben, mit Hilfe einer Ökobilanzierung untersucht. Folgende Systeme wurden untersucht: Eine Infiltrationsanlage, zwei Filterbettsanlagen, eine mit Filtralite® P und eine mit Filtra P als Filtermaterial sowie ein System mit Chemikaliefällung. Die Systemgrenzen umfassten die Gewinnung und Verarbeitung von Rohstoffen, das Errichten der jeweiligen Anlage, deren Betrieb sowie Rückgewinnung und Entsorgung von Restmaterialien. Neben Auswirkungen auf die menschliche Gesundheit und Versauerungspotential, die sich im Nachhinein als weniger relevant erwiesen, wurden Energiebedarf, Verbrauch abiotischer Resourcen, Potential für globale Erwärmung und Eutrophierungspotential untersucht. Die niedrigsten Resultate in allen Kategorien außer Eutrophierungspotential wurden vom Infiltrationssystem erreicht. Filtralite® P erwies sich als am leistungsstärksten, was die Reduktion von eutrophierenden Substanzen angeht. Der Energiebedarf und die Emissionen von Treibhausgasen dieser Alternative überstieg die Ergebnisse der anderen Alternativen in diesen Kategorien doch bei weitem. Filtra P und Chemikaliefällung erzielten moderate Auswirkungen in allen Kategorien. Das Potential für die Rückführung von Pflanzennährstoffen wird, wie die Ergebnisse zeigen, vom relativ hohen Schwermetallhalt in den Restprodukten begrenzt. Chemikaliefällung ist in dieser Studie die beste Alternative. Filtra P zeigte sich als technisch noch zu wenig ausgereift und die Datenunterlage als zu unvollständig, weswegen diese Alternative an zweiter Stelle steht. Die begrenzte Reinigungsfähigkeit des Infiltrationssystemes und das nicht vorhandene Potential für Rückführung von Phosphor führten dazu, dass diese Lösung an dritter Stelle steht. Das System mit Filtralite® P als Filtermaterial wurde wegen seines großen Verbrauchs von fossilen Brennstoffen für wenig brauchbar befunden und steht damit an letzter Stelle. Trotz ihrer hervorragenden phosphorreduzierenden Eigenschaften, wird weitere Forschung im Bereich alternativer Filtermaterialien notwendig werden. Hierbei sollten natürliche Materialien (wie Muschelsand) oder Restprodukte im Mittelpunkt des Interesses stehen, um die Umweltauswirkungen gering zu halten. Wenn die Rückführung von Phosphor ein Ziel der Abwasserreinigung sein soll, müssen Lösungen, Schwermetalle von Pflanzennährstoffen zu trennen, gefunden werden. Diese Studie hat gezeigt, dass gute phosphorreduzierende Eigenschaften zu verstärkten Umweltauswirkungen in anderen Bereichen führen können, welche in manchen Fällen sogar die Vorteile einer verringerten Eutrophierung übersteigen können.
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Bioenergy Systems in Canada: Towards Energy Security and Climate Change SolutionsHacatoglu, Kevork 10 December 2008 (has links)
The energy security and climate change risks of fossil fuel consumption have stimulated interest in developing renewable energy sources. Canada’s vast biomass potential is an attractive local resource but high transportation costs are a barrier to implementation. This study assesses how transformative systems can enable large-scale bioenergy production through integration with existing transportation corridors and fossil fuel infrastructure. Potential bioenergy corridors include the network of natural gas pipelines and the Great Lakes St. Lawrence Seaway (GLSLS).
Sustainable lignocellulosic biomass production integrated with traditional food and fibre production was assumed to occur on 196 Mha of land within 100 km of pipelines. Conservative (81 Mt of dry biomass per year) and aggressive (209 Mt) scenarios were investigated for converting biomass to synthetic natural gas (SNG) via gasification, methanation, and upgrading, yielding enough pipeline-quality gas to meet 20% to 60% of Canada’s current needs. A systems analysis approach was used to calculate bioSNG life-cycle emissions of 15 to 18 kgCO2e GJ-1, compared to 68 or 87 for conventional or liquefied natural gas, respectively. Production costs ranged from $16 to $20 GJ-1, which were high compared to regional gas prices ($5 to $10 GJ-1).
The biomass potential on 125 Mha of land area within 100 km of the Canadian portion of the GLSLS and railway lines ranged from 36 to 80 Mt(dry) per year, which was enough to displace coal-fired power in Ontario plus produce 1.6 to 11 billion L of green diesel that could offset 14% to 96% of fossil diesel in GLSLS provinces. Life-cycle emissions ranged from 110 to 130 gCO2e kWh-1 for biopower (compared to 1030 for coal) and 20 to 22 kgCO2e GJ-1 for green diesel (compared to 84 for conventional diesel). Cost estimates ranged from $130 MWh-1 for biopower (compared to an average market power price of $54 MWh-1) and $28 to $36 GJ-1 for green diesel (compared to $16 to $24 GJ-1 for diesel). The auxiliary benefits (energy security, climate change, air quality, and rural development) were seen as justification for supportive bioenergy policies. / Thesis (Master, Environmental Studies) -- Queen's University, 2008-12-09 15:24:18.389
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