Дисертації з теми "Material Flow Analysi"

Understanding the environmental implications of consumption and production depends on appropriate monitoring tools. Material flow accounting (MFA) is a method to monitor natural resource use by countries and has been widely used in research and policy. However, the increasing globalization requires the consideration of "embodied" material use of traded products. The indicator raw material consumption (RMC) represents the material use - no matter where in the world it occurs - associated with domestic final demand. It provides a consumption-based perspective complementary to the MFA indicators that have a territorial focus. Several studies on RMC have been presented recently but with diverging results; hence, a better understanding of the underlying differences is needed. This article presents a comparison of Austrian RMC for the year 2007 calculated by six different approaches (3 multi-regional input-output (MRIO) and 3 hybrid life-cycle analysis-IO approaches). Five approaches result in an RMC higher than the domestic material consumption (DMC). One hybrid LCA-IO approach calculates RMC to be lower than DMC. For specific material categories, results diverge by 50% or more. Due to the policy relevance of the RMC and DMC indicators it is paramount that their robustness is enhanced, which needs both data and method harmonization.

L'ampli ús de materials als edificis contribueix a l'escassetat de recursos naturals i a l'abocament de residus al medi ambient. L'Anàlisi del Flux de Materials (MFA) s'ha utiliyat com a eina per aconseguir a desmaterialització i la sostenibilitat dels edificis existents. Aquesta tesi s'organitza en tres capitols principals. El primer capitol presenta una revisi bibliogràfica i un anàlisi bibliometric per recolyar lus sistematic de MFA. El segon capitol proposa un metode basat en el MFA per a modelar la poblacio dels edificis residencials a la ciutat de Rio de Janeiro i el flux de materials de residus, per tal de caracteritzar lstock d'edificis. El tercer capitol introdueix lus combinat de les metodologies d'Anàlisi de Ciclo de Vida i MFA per a modelar els fluxos residuales de la poblacio d'edificis i per a avaluar els seus impactes de cicle de vida. En resum, aquesta tesi explora les variants de la metodologia d'Anàlisi de Flux de Materials i promou un ampli anàlisi dels edificis i dels impactes de cicle de vida dels fluxos de residus.
El amplio uso de materiales en los edificios contribuye a la escasez de recursos naturales y al vertido de residuos en el medio ambiente. El Análisis del Flujo de Materiales (MFA) se ha utilizado como una herramienta para lograr la desmaterialización y la sostenibilidad de los edificios existentes. Esta tesis se organiza en tres capitulos principales. El primer capítulo presenta una revisión bibliográfica y un análisis bibliométrico para apoyar el uso sistemático del MFA. El segundo capítulo propone un método basado en el MFA para modelar la población de los edificios residenciales en la ciudad de Río de Janeiro, y el flujo de materiales y de residuos, con el fin de caracterizar el stock de edificios. El tercer capítulo introcuce el uso combinado de las metodologías de Análisis de ciclo de Vida y MFA para modelar los flujos residuales de la población de edificios y para evaluar sus impactos. En resumen, esta tesis explora las variantes de la metodología de Análisis de Flujo de Materiales y promueve un amplio análisis de los edificios y de los impactos del ciclo de vida de los flujos de residuos.
The extensive use of materials in buildins stocks contributes to the scarcity of natural resources and waste disposal on the environment. Material Flow Analysis (MFA) has been used as a tool to achieve dematerialization and sustainability of buildings stocks. This thesis is organized in three main chapters. The first chapter presents a literature review and a bibliometric analysis for supprting the systematic use of MFA. The second chapter proposes a method based on MFA to model the residential building stock in the city of Rio de Janeiro and their material and waste flows, in order to characterize the stock. The third chapter introduces the combinated use if MFA and Life Cycle Assessment methodologies to model waste flows from a building stock and to assess its life cycle impacts. In summary, this Thesis explores the variants of the MFA and promotes a broadly analysis of a building stocks and life cycle impacts from waste flows.

This report is the result of a Master Thesis written at Toyota Material Handling Europe (TMHE), with the purpose to map the existing spare part supply chain structure and to analyse future suggested supply chain structures with a focus on transportation flows.

TMHE is one of the world’s largest producing forklift distributers with large market shares throughout Europe. Besides the main activity of forklifts the aftermarket of distributing spare parts is a major business. With a current decentralised supply chain, the Future Logistic Concept (FLC) project was established to analyse the possibilities of a more centralised European supply chain.

While earlier analyses within the FLC have been focusing on the customer market, this thesis aims towards completing with analyses on the opposite side of the supply chain. It will present an aggregated view over a possible FLC supply chain setup with focus on suppliers, replenishment flows and usage of express transportation solutions.

An analysis was performed based on supplier localisation and historically delivered tonnages. To be able to analyse the replenishment flows between European Distribution Centre (EDC) and Regional Distribution Centres (RDC), an inventory control and transportation model was developed. The model calculates costs for inventory holding, replenishment flows and express flows and optimises the relationships between these controlling variables. This makes it possible to analyse the transportation flows in a specified set of possible supply chain structures.

The results of the localisation analyses based on suppliers, show that the central part of the supply chain should be located in the northern parts of central Europe. To be able to minimise the supplier inflow facilities should be established in Mjölby and Ancenis. A warehouse in Eastern Europe is probably necessary to be able to keep customer lead times at an acceptable level, but from a supply point of view this location is not supported due to the low amount of Easter European suppliers.

The results from the model suggests a supply chain structure with a central distribution centre in Antwerp, Belgium (Scenario 2 in the analysis) and regional warehouses in Sweden, United Kingdom, Spain, Italy and the Czech Republic.

Friction StirWelding (FSW) has been researched for a number of years since its inception in 1991. The work thus far has been based on understanding the material and thermal flow using the standard fixed pin tool. The keyhole resulting during tool extraction in a FSW weld, is a disadvantage and a current limiting factor. Eliminating this effect from a weld using a movable pin tools would make FSW more commercially viable. This dissertation focuses on the design of a novel retractable pin tool, and highlights the problems encountered during the welding of Aluminum plates, Al2024 and Al5083. Previously studied techniques of material and thermal flow were used, to investigate the effect of the tool during extraction in a FSW weld. A prototype retractable tool was designed using parametric and axiomatic design theory, and implementing a pneumatic muscle actuation system. The resulting problems in the calibration of the retractable pin tool and the resulting welds are presented, these results confirming previous studies. The movable pin produced discrepancies the heat generation around the shoulder during a FSW weld. The failure of this tool to produce a reasonable weld showed that previous ideas into the workings of a retractable pin tool requires further investigation, furthermore a fresh approach to the interpretation and understanding of the FSW weld process needs consideration.

Agriculture currently faces a number of environmental sustainability issues. Three key issues that are the focus of this study are greenhouse gas emissions, depletion of mineral phosphorus resources and cadmium contamination in agricultural soil. Biomass can potentially be used as a renewable energy source and can also be returned to improve the nutrient and drainage structure of agricultural soils. Sustainable management of biomass and agriculture can have significant impacts on reducing greenhouse gas emissions from a region. Moreover, it reduces the demand for external energy supply, phosphorous (P) based fertilizer, and it??s associated Cadmium (Cd) impurity which can contaminate the soil, plant and food chains. These three issues have typically been considered separately, and managed by different agencies or organisations. The aim of this thesis is to develop an integrated decision support tool that can be used for evaluating alternative options for management and resource recovery from biomass for enhancing recovery of energy, returning carbon (C) and phosphorus (P) from biomass back to soil, reducing greenhouse gas emissions and also cadmium (Cd) contamination in an agricultural region. This research employed a combination of the tools of Material Flow Analysis (MFA), Geographic Information System (GIS) and Cost-Benefit Analysis (CBA). MFA is used as the primary tool for this research. GIS and CBA are combined with MFA in later stages of the overall procedure to develop an integrated decision support tool. This integrated tool has been applied to the Murrumbidgee Irrigation Area (MIA) in Australia. Tracking the flow of essential substances using MFA has identified current resource management efficiency and substances accumulation across the region. Integrating a spatial analysis tool (GIS) with MFA has provided a feedback driven monitoring tool for evaluating trends of spatial accumulation of substances on agricultural land. This enables the time remaining before acceptable limits are exceeded to be estimated on a spatial basis. Integrated MFA and CBA has been applied to evaluate the tradeoffs and potential synergies of alternative biomass management options. Overall the tool can assist in evaluating the effectiveness of alternative scenarios and visualise the results to stakeholders in a systematic way.

As cidades podem ser definidas como sistemas abertos altamente dependentes do seu entorno para a provisão dos recursos naturais e eliminação dos resíduos. Abarcando 2% da superfície da terra, elas consomem aproximadamente 75% de seus recursos, expulsando resíduos em escala similar. Na atualidade, 50% da população mundial habita em cidades e é estimado que esta porcentagem ascenderá a 70% no 2050. Em particular, a América Latina apresenta uma crescente população urbana. No ano 1970, 57 % da população era urbana e estima se que se atinja 81% no 2025. O Uruguai é o país de América Latina de maior porcentagem de população urbana: 93%, em 2010. A Análise de Fluxos de Materiais (AFM) é una metodologia de avaliação do campo da economia ecológica que tem sido pouco considerada na planificação ou gestão urbana regional. Argumenta-se que essas abordagens são as que podem dar luz a um modelo de desenvolvimento de cidades mais sustentáveis, contribuindo para a definição de políticas publicas ambientais. O objetivo do trabalho é estimar quantitativamente o consumo doméstico de materiais (CDM) para a cidade de Montevidéu, no período entre os anos 2002 e 2009. Os principais desafios do trabalho foram a inexistência de metodologias de consenso de aplicação regional e a dificuldade na aquisição de dados, os quais se encontram em sua maioria desagregados em diferentes instituições públicas e privadas. O referencial metodológico adotado foi o proposto por EUROSTAT, aplicado a nível nacional pelas maiores economias da OCDE. O trabalho propõe uma estratégia de ponderação que permite a passagem da escala nacional á urbana, Os resultados obtidos evidenciam um aumento no consumo de materiais em Montevidéu na serie de anos analisada, sendo 80% deles de origem não renovável no ano 2009. A indústria da construção é responsável por mais de 50% do consumo total. A estimação quantitativa do CDM, para a cidade de Montevidéu, é um primeiro passo na identificação de alternativas para uma menor intensidade no uso de materiais, condição indispensável para um relacionamento mais equilibrado entre os sistemas socioeconômicos e o médio ambiente. O CDM de Montevidéu é uma ferramenta em processo, passível de ser aprimorada em futuros trabalhos. A principal dificuldade deste trabalho foi a compatibilização dos diferentes critérios de classificação de materiais da metodologia da EUROSTAT e das bases de dados nacionais.
Cities can be defined as open systems that are highly dependent on their environment for the provision of natural resources and waste disposal. Although cities only cover 2% of the surface of the earth, they consume 75% of its resources. Currently, 50% of the world population lives in cities and it is estimated that this number will rise to 70% in the year 2050. This phenomenon is remarkable in Latin America. While in 1970 its urban population was 57%, it is expected to climb to 81% by 2025. In this context, Uruguay is the country of Latin America that present the higher rate of urban population: 93% (year 2010). The Material Flow Analysis (MFA) (an evaluation methodology from the field of ecological economics) has not been contemplated on regional planning and urban management. However, it is argued that these approaches can enlighten the development of more sustainable cities contributing to the definition of environmental public policy. The aim of this work is to quantify the domestic consumption of materials (fossils, minerals and biomass) for the city of Montevideo, Uruguay for the years 2006 and 2009. At this point, the main barriers are the lack of agreed on regional implementation methodologies and the difficulty with data acquisition. The methodological guide to be used is the one defined by Eurostat, applied nationally for several years by the greatest OECD economies. The paper proposes a weighting strategy that allows the passage from a national scale to an urban one.The results obtained for the period of time analized show an increase in consumption of materials and energy. For instance, the consumption of non-renewable sources reached 80% for the year of2009. On this period, the construction industry was responsible for the 50% of the total consumption. This diagnosis let us perceive the paths to follow in order to reduce the intensity of the use of materials and energy, wich is imperative to create a balanced relationship between socioeconomic systems and the environment. The DMC of Montevideo is a tool in the process, which can be improved in future works. The main difficulty of this work was to reconcile the different criteria of classification of materials from EUROSTAT methodology with national databases.

Ésta tesis tiene como objetivo evaluar el consumo de recursos del sector de la construcción, los residuos y las emisiones generadas por el sector. Ésto está motivado por el hecho de que el sector de la construcción es responsable de una gran cantidad de consumo de recursos y representa casi el 9% el valor bruto añadido al producto interno bruto del mundo. La evaluación considera la perspectiva del ciclo de vida, desde la extracción de materias primas, a través de la construcción y fabricación de productos, materiales de transporte, la construcción, la generación de residuos de demolición, el transporte de residuos, el tratamiento y disposición final. El objetivo es identificar las oportunidades y mejorar los criterios de selección de materiales, el procesado, la reutilización y el reciclado para el uso sostenible de los recursos. Debido a la complejidad de los sistemas de edificios e infraestructuras, compuestas de muchos componentes que interactúan, siempre es difícil llevar a cabo una contabilidad de los recursos precisos dentro de éste sector. En esta perspectiva, el concepto de análisis de flujo de materiales y la evaluación del ciclo de vida (ACV), y el análisis de exergía se tratan como herramientas de contabilidad de recursos y se centra en sus aplicaciones en el sector de la construcción. Además del análisis sectorial, ésta tesis, también analiza la eficiencia de los procesos de fabricación y el ciclo de vida completo de los productos con base a exergía. Todos los procesos y los productos seleccionados son relevantes para el sector de la construcción, y éste análisis tiene como objetivo proporcionar conocimientos de despersonalización en el uso de materiales del sector. En el capítulo 1, se expone el marco teórico en que los análisis de flujo de exergía y los materiales se utilizan en la evaluación del metabolismo de los recursos del sector de la construcción, que destacan la importancia de éste sector en términos de flujos de recursos y la generación de residuos y emisiones. Éste capítulo, también introduce la eficiencia exérgica y herramientas de evaluación del ciclo de vida exergéticos, que explica las limitaciones del análisis de la energía y el ACV, y cómo la aplicación de éstos métodos a base de exergía puede ofrecer mejores perspectivas sobre la eficiencia del uso de los recursos en los procesos de fabricación en toda la vida de los productos, respectivamente. La Ecología Industrial, se presenta al introducir el enfoque basado en los sistemas y el marco termodinámico en el que el sector de la construcción se analiza en este estudio. El capítulo 2, presenta los resultados de los análisis de flujo de materiales y exergía del sector de la construcción catalana en el año 2001. En ese momento, Cataluña tenía un adicional de 52 millones de toneladas de existencias de materiales para el sector y generaba 7 millones de toneladas de residuos de construcción y demolición, de los cuales sólo el 6,5% son recicladas o regeneradas. El estudio muestra que la fase de fabricación consume la mayor parte de los recursos de energía durante el ciclo de vida del conjunto de los productos, seguidos de transporte de materiales, que representa el 57% y el 4% del consumo de exergía, respectivamente. Se señala que la mejora en la selección de materiales, tecnologías de fabricación y diseño para el desmontaje, conduce a la sostenibilidad del sector, para conseguir una mejora de la eficiencia del uso de recursos. En el capítulo 3, se menciona el rendimiento exergético de los procesos de producción, tanto en el proceso de producción primaria como secundaria (reciclaje), de los materiales de construcción que se calcula, con el fin de evaluar la calidad de los materiales, las pérdidas de exergía, y el potencial de mejora de procesos. Ésto sirve para cuantificar el potencial de mejora de los procesos de fabricación actuales que abordan las deficiencias de fabricación de los nueve principales materiales de construcción no renovables: aluminio, acero, cobre, cemento, hormigón, cerámica, vidrio, polipropileno y cloruro de polivinilo. La Eficiencia Exergía basada en la segunda ley de la termodinámica es determinada con el fin de comparar la eficiencia exergía teórica y la eficiencia exergía del proceso real. La gran diferencia entre los requisitos teóricos y empíricos de exergía en los procesos de fabricación sugiere que las oportunidades para una mejor utilización de exergía industrial todavía existen, pero requieren un diseño y mejoras en la tecnología. Los resultados demuestran que los recursos se utilizan de manera más eficiente en los procesos de reciclaje, en comparación con los procesos de fabricación primaria. En esta tesis se presenta una teoría (capítulo 4) para determinar como de eficientemente se utilizan los recursos en las aplicaciones de la construcción, utilizando la metodología de análisis del ciclo de vida exergético desde un enfoque universal. Esto incluye la extracción de materias primas, la fabricación de resina y de gestión de las etapas del ciclo de vida de los residuos al final de su vida. La irreversibilidad durante el ciclo de vida completo permite evaluar el grado de perfección termodinámica de los procesos de producción y llevar a cabo la evaluación de la cadena de producción entera. Ciclo de vida global de la eficiencia exérgica de polipropileno y cloruro de polivinilo se cuantifica en 27,1% y 9,3%, respectivamente, que se caracteriza por una baja eficiencia en la fabricación y los procesos de reciclaje para ambos materiales. Desde el punto de vista de la conservación de recursos, el reciclado mecánico se ha sugerido como la opción viable para la gestión de residuos de plástico al final de su vida, ya que los materiales de bucles vuelven a su ciclo de vida original y reduce las aportaciones de recursos primarios en la producción.
This thesis aims to assess the resource consumption of the construction sector, and the wastes and emissions generated by the sector. This is motivated by the fact that the construction sector is responsible for large amounts of resource consumption and represents nearly 9% gross value added to the world’s gross domestic product. The assessment considers the life cycle perspective from raw material extraction, through construction product manufacturing, material transport, construction and demolition waste generation, to waste transport, treatment, and final disposal. The aim is to pinpoint the opportunities for improved material selection criteria, processing, reuse, and recycling for sustainable resource use. Due to the system complexity of buildings and infrastructure, composed of many interacting components, it is always challenging to undertake an accurate resource accounting within this sector. In this perspective, the concepts of material flow analysis (MFA), life cycle assessment (LCA), and exergy analysis (ExA) are discussed as resource accounting tools focusing on their applications in the construction sector. Apart from sectoral analysis, this thesis also analyzes the efficiency of manufacturing processes and products’ complete life cycle based on exergy. All the processes and products selected are relevant for the construction sector, and this analysis aims to provide deper insights into sectoral material use. Chapter 1 details the theoretical framework under which exergy and material flow analyses are used in assessing the resource metabolism of the construction sector highlighting the importance of this sector in terms of resource flows, and generation of waste and emissions. This chapter also introduces the exergy efficiency and exergetic life cycle assessment (ELCA) tools, explaining the limitations of energy analysis and LCA, and how the application of these exergy-based methods can provide better insights into resource use efficiency in manufacturing processes and throughout the products’ life, respectively. Industrial ecology (IE) is presented to introduce the systems-based approach and thermodynamic framework on which of the construction sector is analyzed in this study. Chapter 2 presents the results of material and exergy flow analyses of the Catalan construction sector for the year 2001. In 2001, Catalonia had an additional 52 million tonnes of material stock to the sector and generated 7 million tonnes of construction and demolition waste (CDW) of which only 6.5% were recycled or reclaimed. The study shows that manufacturing stage consumes the largest fraction of energy resources during the products’ whole lifecycle followed by material transport, accounting for 57% and 4% of exergy use, respectively. It is pointed out that improvement in material selection, manufacturing technologies, and design for disassembly lead to sustainability of the sector delivering improved resource use efficiency. In chapter 3, the exergetic efficiency of the production processes, both primary and secondary (recycling) production process, of construction materials is calculated in order to assess material quality, exergy losses, and process improvement potentials. This serves to quantify the improvement potentials for present manufacturing processes addressing the manufacturing inefficiencies of nine major non-renewable construction materials: aluminum, steel, copper, cement, concrete, ceramic, glass, polypropylene (PP), and polyvinyl chloride (PVC). Exergy efficiency based on the second law of thermodynamics is determined in order to compare the theoretical exergy efficiency and the real-process exergy efficiency. The large difference between theoretical and empirical exergy requirements in manufacturing processes suggests that opportunities for better industrial exergy utilization still exist but require design and/or technology improvements. The results demonstrate that resources are utilized more efficiently in recycling processes compared to primary manufacturing processes. This thesis has presented an effort (chapter 4) to pinpoint how efficiently resources are used in the construction applications, using exergetic life cycle assessment methodology in a cradle-to-grave life cycle approach. This included raw material extraction, resin manufacturing, and end-of-life waste management life-cycle stages. The irreversibility during the complete life cycle allows to evaluate the degree of thermodynamic perfection of the production processes and to conduct the assessment of the whole process chain. Overall life cycle exergy efficiency of PP and PVC is quantified 27.1% and 9.3%, respectively, characterized by a low efficiency of manufacturing and recycling processes for both materials. From resource conservation point of view, mechanical recycling has been suggested as the viable option for end-of-life plastic waste management, since it loops materials back directly into new life cycle and reduces primary resource inputs in the production.

Landfilling waste material is still one of the most common methods to take care of waste in a big part of the world. Gaborone, the capital of Botswana located in the southern part of Africa is no different in this way. The major part of all waste is landfilled in Gaborone and there is only a minor part of all collected material that is recycled. One solution that earlier studies suggest is to build a transfer and recycling station in the city of Gaborone that can contribute to a more sustainable waste management. This study aims to identify the major waste streams of recyclable waste and also the major stakeholders that are active in this area through an exploratory study involving interviews, a workshop and a survey. The result of this thesis can hopefully assist in the preparations for such a transfer station. The conclusions of this study are many and contains of both hard facts and also loose ends that can contribute to pursue further studies. The first important result is that all the waste collection companies transports everything they collects to a landfill and it is only recycling organizations that are working with collection and recycling in Gaborone. These recycling organizations are a few but smaller compared to the waste collection companies in collected amounts of material. Besides these collection organizations, Gaborone City Council, the local municipality works with collection of household waste and the collaboration between these three groups that operates in the same environment is very poor. All the interviewed stakeholders showed a positive interest in the transfer and recycling station but there is only a small part of the commercial business in Gaborone that believes in a more serious waste management than landfilling. Despite that one major shopping mall actually sort out recyclables and saves 30% in waste management costs thanks to that. Another issue is the prevailing cultural contradictions that is obvious among the organizations in Gaborone. The last two bigger issues is the tremendously dull political bureaucracy that is appearing in Botswana and also that voices are raised that corruption is great beneath the surface.

Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2006.
Dr. Yih-Long Chang, Committee Member ; Dr. Martin Savelsbergh, Committee Member ; Dr. Leon McGinnis, Committee Co-Chair ; Dr. Gunter Sharp, Committee Chair ; Dr. Doug Bodner, Committee Member ; Dr. Joel Sokol, Committee Member.

Abstract This thesis explored innovative ways to improve estimation of material footprint-type indicators in application of Input-Output (IO) analysis to Material Flow Accounting. The following six research questions were addressed: 1) What is the potential impact of sector aggregation in IO modelling of raw material flows? Modelling errors due to aggregation of industries with dissimilar material requirements and trade structures into a single sector in IO models when calculating the material footprint were empirically analysed relative to greenhouse gas emissions. Significant biases emerged for raw material flows, which suggests that care should be taken when aggregating extractive sectors in IO models. 2) Can bottom-up approaches, such as LCA (Life Cycle Assessment), improve estimation of the raw materials embodied in trade products? and 3) What are the implications of integration of country-specific information from high geographical coverage IO models into LCA approaches for calculation of raw material embodied in trade products? An approach for combining country-specific production blueprints with LCA based on regional averages was developed. This approach proved useful in refining estimates of upstream raw materials embodied in trade products, although care is needed during its application since new biases may arise. 4) Can further perspectives be gained with a new allocation method, the ‘value added-based material footprint’, which assigns supply chain-wide raw material extractions to each participating economic actor according to its added value generation, contributing to discussions on the distribution of mitigation costs? Certain countries and sectors were found to be more material-intensive with this new accounting approach than in other widely known allocation methods, e.g. consumer footprint. 5) Are there unequal exchanges between high-income economies and middle- and lower-income countries when measured in terms of raw material and value added flows? and 6) Could integration of local and global IO data provide useful insights to study presence/absence of unequal material exchange at sub-national level? A study of material flows at inter- and intra-national level demonstrated that a regional economy can play a twofold role, both as sink or source of raw materials and in value added, depending on its position in the global economic hierarchy
Tiivistelmä Tässä työssä tutkittiin innovatiivisia tapoja, joilla voitaisiin parantaa materiaalijalanjälki -tyyppisten indikaattoreiden käytettävyyttä panos-tuotos (Input-Output, IO) -analyysissa, kun niitä sovelletaan Materiaalivirta-analyysi (Material Flow Accounting, MFA) -metodiin. Seuraaviin tutkimuskysymyksiin haettiin vastauksia: 1) Mikä on sektorien yhdistämisen potentiaalinen vaikutus raaka-ainevirtojen IO-mallintamisessa ja miten poikkeamia voidaan estää? Tämän puitteissa tarkasteltiin mallinnusvirheitä, jotka johtuvat erilaisten toimialojen yhdistämisistä yhdeksi sektoriksi. 2) Voivatko alhaalta ylöspäin suuntautuvat lähestymistavat, kuten elinkaariarviointi parantaa tuotteisiin sisältyvien raaka-ainevirtojen arviointia? ja 3) Mitä vaikutuksia on laajan maantieteellisen kattavuuden IO-malleihin sisältyvien maakohtaisten tietojen yhdistämisestä LCA-pohjaisiin lähestymistapoihin, kun tavoitteena on laskea tuotteisiin sisältyviä raaka-ainemääriä? Tämän tutkimista varten kehitettiin lähestymistapa, joka yhdisti maakohtaiset tuotantosuunnitelmat ja elinkaariarvioinnin. Tämä lähestymistapa osoittautui hyödylliseksi tarkentamalla arvioita tuotteissa olevista raaka-aineista, vaikkakin sen soveltaminen edellyttää varovaisuutta, koska uusia vääristymiä voi syntyä. 4) Voidaanko uusia näkökulmia löytää uudella arvonlisäykseen perustuvalla allokointimenetelmällä, joka jakaa raaka-aineen louhinnan kullekin toimintaketjun osallistuvalle taloudelliselle toimijalle lisäarvon tuotannon mukaan? Tämän uuden kirjanpitomenetelmän mukaan jotkut maat ja alat ovat materiaali-intensiivisempiä kuin niitä on pidetty kulutuksen jalanjälkiallokointimenetelmien perusteella. 5) Onko korkean tulotason talouksien ja keskitasoiselle ja alhaiselle tulotasolle asettuvien maiden välillä epätasaisia vaihtoja, kun raaka-ainekulutusta ja arvonlisäystä mitataan? ja 6) Voisiko paikallisten ja globaalien IO-tietojen integrointi antaa hyödyllisiä näkökulmia tutkimukseen, joka tarkastelee epätasaisen aineenvaihdon esiintymistä tai puuttumista alueellisella tasolla? Materiaalivirtojen tutkiminen kansainvälisellä ja kansallisella tasolla, jossa yhdistettiin IO-tietokannat erilaisella maantieteellisellä resoluutiolla osoitti, että alueellisella taloudella voi olla kaksoisrooli sekä raaka-aineiden että arvonlisäyksen lähteenä tai nieluna riippuen sen asemasta globaalissa taloushierarkiassa

This thesis has been performed in Gaborone, Botswana, where all interviews and relevant research data collection took place. The main method of data collection was a semi-structured interviews with relevant parties involved in waste management and generation in Gaborone.This work is part of a larger feasibility study called “Gaborone Transfer and Recycling Station (GTARS)”. The main objective is to make waste management in Gaborone more sustainable, taking environmental, social and economic aspects into account. The aim of this master thesis is to investigate the waste flow rates and composition in the capital city of Botswana, Gaborone. Taking this into account, other factors which directly influence waste generation and composition are identified. The findings show that currently in the year 2014, the city of Gaborone is generating about 348 tons of solid waste per day.Further investigation showed that illegal dumping is a prominent practice in Gaborone, mostly due to the long distance to the landfill and generally low environmental awareness amongst the citizens of the city. The waste generation rates are increasing every year, because the city of Gaborone is expanding rapidly and economic conditions facilitate the increasing urbanization rate. The analysis done till the year 2024 indicate that waste amounts might reach up to 433 tons of solid waste generated per day. Waste composition analysis is constrained, because of the limited data sources available on this subject, but the analysis shows that paper, biodegradable waste and plastics are the main fractions found in the municipal waste stream.
Gaborone Transfer and Recycling Station (GTARS)

Effective implementation of resource policies requires consistent and robust indicators. An increasing number of national and international strategies focussing on resource efficiency as a means for reaching a green economy call for such indicators. As supply chains of goods and services are increasingly organised on the global level, comprehensive indica-tors taking into account upstream material flows associated with internationally traded products need to be compiled. Particularly in the last few years, the development of con-sumption-based indicators of material use also termed material footprints has made considerable progress. This paper presents a comprehensive review of existing methodol-ogies to calculate material footprint-type indicators. The three prevailing approaches, i.e. environmentally extended input-output analysis (EE-IOA), coefficient approaches based on process analysis data, and hybrid approaches combing elements of EE-IOA and process analysis are presented, existing models using the different approaches discussed, and advantages and disadvantages of each approach identified. We argue that there is still a strong need for improvement of the specific approaches as well as comparability of re-sults, in order to reduce uncertainties. The paper concludes with recommendations for further development covering methodological, data and institutional aspects.

This thesis details the design, fabrication and characterisation of a 13 mm-diameter axial flow microturbine with an integrated electromagnetic generator. Axial turbine blades are not amenable to fabrication by traditional MEMS (micro-electromechanical systems) processes because they cannot be produced by machining prismatic shapes into the rotor disc; the direction of machining has to change as material is removed to produce the required blade curvature. This challenge was met by laser machining the blades with a novel moving-mask process so as to produce a step-wise approximation to the desired profile. The chosen material for making the microturbine rotor was the negative photo-resist SU-8. Once properly cured into its solid state, this polymer becomes very durable and dimensionally stable. The SU-8 was readily preformed using lithography and RIE (reactive ion etching), and was also responsive to excimer laser ablation as necessary for finishing the blade profiles. The microturbine was designed to be assembled into a stacked MEMS device comprising a rotor embedded with ten rare earth magnets sandwiched between upper and lower silicon stators carrying electroplated generator coils. Characterisation of the turbine showed that mechanical losses, mainly in the bearings, were significantly reducing the efficiency. A laser scanning vibrometer (Polytec MSA-400) was used to measure the turbine rundown time which was found to be only ~150 ms due to high bearing friction. The in-plane and out-of-plane vibration (wobble) of the rotor as it spun around on its micro roller bearings were also mapped to determine if bearing alignment was reducing power output. The out-of-plane vibration was found to be the main problem, so a new one-piece rotational support holder was constructed for the device. Some microturbine rotors were found to shatter above 100,000 rpm, and this led to interest in the mechanical properties of the cured SU-8. Firstly, PGAA (prompt gamma activation analysis) was used to measure the constituent element percentages and contaminants in a range of SU-8 samples subjected to different heat curing temperatures and UV cross-linking times. It was of interest to see how the O and H percentages changed as these are normally expected to vary depending on temperature and humidity. SANS (small angle neutron scattering) tests were also performed using a 10 MW reactor which measured sub-surface scattering for the same samples to reveal material defects.

Master thesis named „Creation of logistic concept in the selected company“ is focused on detailed analysis of material flow of waste in manufacturing company. The main objective of thesis is proposal of new logistic concept of handling with copper waste, which is created during the manufacturing processes, which function will be to remove defects in material flow, to shorten the handling time with copper waste and more accurate information flow, considering work safety, costs and time.

Thesis (MPhil)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The current ways in which the human population continues to utilise natural resources in order to satisfy their lifestyle remains unsustainable. One such activity is the use of biomass resources mainly for cooking, heating and boiling water which sustains an estimated 2.4 billion people living in developing countries. Biomass not only is the fourth largest energy source after coal, oil and natural gas, but it is currently the largest renewable energy option and yet it has received minimal attention especially from current energy debates in developing countries. Literature shows cases of cities that remain ‘uncertain’ of their development agendas (regarding energy). The uncertainty is a result of most cities relying heavily on fossil fuel which is in most cases imported which minimises the possibilities of cities to come up with sustainable energy projects. As cities continue to grow the supply of this unsustainable energy puts cities in an uncertain position regarding the future energy sources of their cities. There are cities that have now realised the importance of understanding the flow of wood fuels in order to put in measures that can help manage the resource better. Most of them use a GIS-based tool, Wood fuel Integrated Supply Demand Overview Mapping Model (WISDOM) which was developed to analyse the wood fuel supply and demand spatial patterns. Tsumeb is currently also moving in an ‘uncertain’ direction especially when it comes to the energy needs of the town characterised by high electricity tariffs, increased population leading to clearing of land, high unemployment rate and distorted priorities (of the municipality). The Material Flow Analysis (MFA) of wood fuels in Tsumeb is highly dominated by the informal sector. It remains unregulated and no attempt has been made to determine the household energy flow. This study is the first attempt to determine the flow of this very important household energy resource used more especially in winter. The survey revealed that firewood is used to prepare one to two meals a day especially in the townships where the households opt to consume one meal a day. Some consumers collect their own firewood and often have to purchase wood fuels to meet their individual needs. The wood fuel retailers that were surveyed in the study obtain their wood fuels from local commercial farmers and use charcoal produced both in Namibia and South African. The commercial farmers also form part of the informal sector as they supply some of the informal suppliers and consumers. Some informal suppliers resort to open forests located far from their homes, putting a lot of strain on the transport mechanisms. In order to ensure a sustainable supply of household energy in Tsumeb, It is inevitable that a new paradigm is needed in the current planning and development process of the town. Therefore for an effective implementation of policies aimed at developing wood fuels, local conditions as well as the local wood fuel flows must be understood, grassroots initiatives need to be built and community participation should be encouraged in order to get a collective approach to issues that concerns and threatens their livelihoods.
AFRIKAANSE OPSOMMING: Die wyse waarop die mensdom natuurlike hulpbronne aanwend om aan die eise van hul leefstyl te voldoen, bly onvolhoubaar. Een sodanige aktiwiteit is die gebruik van biomassahulpbronne, hoofsaaklik vir kosvoorbereiding en ruimte- en waterverhitting. Biomassahulpbronne onderhou geraamde 2,4 miljard inwoners van ontwikkelende lande. Dit is nie net die grootste energiebron naas steenkool, olie en aardgas nie, maar is ook tans die belowendste bron van hernubare energie. Tog ontvang dit weinig aandag. Hoewel literatuur steeds merendeels oor gevalle handel wat ‘onseker’ is oor hul ontwikkelingsagendas, is daar tóg diegene wat uiteindelik besef hoe belangrik dit is om die vloei van houtbrandstof te begryp ten einde maatreëls te tref om dié hulpbron beter te bestuur. Die meeste van hierdie lande gebruik GIS-gebaseerde instrument, naamlik die WISDOM-model (“Wood-fuel Integrated Supply Demand Overview Mapping”), wat ontwikkel is om die ruimtelike patrone van houtbrandstofvraag en -aanbod te ontleed. Die Namibiese stad Tsumeb is een van die ‘onsekeres’, veral wat sy energiebehoeftes betref, en word gekenmerk deur hoë elektrisiteitstariewe, groeiende bevolking wat al hoe meer ontbossing tot gevolg het, hoë werkloosheidsyfers en verwronge prioriteite. Die materiaalvloeiontleding wat in hierdie studie met betrekking tot die houtbrandstof in Tsumeb onderneem is, word in groot mate deur die informele sektor oorheers. Hoewel die gebruik van houtbrandstof steeds ongereguleerd is, is geen poging tot dusver aangewend om die vloei van dié uiters belangrike huishoudelike energiebron, wat veral in die wintermaande gebruik word, te bepaal nie. Die opname het getoon dat brandhout gebruik word om een tot twee maaltye per dag te berei, veral in die townships waar die huishoudings meestal een keer per dag eet. Party verbruikers maak hulle eie brandhout bymekaar, maar moet steeds bykomende hout koop om in ál hulle behoeftes te voorsien. Die houtbrandstofhandelaars wat aan die opname deelgeneem het, bekom hul houtbrandstof van plaaslike kommersiële boere en van Namibiese sowel as Suid-Afrikaanse houtskoolverskaffers. Die kommersiële boere maak ook deel uit van die informele sektor, aangesien hulle sommige informele verskaffers en verbruikers van brandstof voorsien. Van die informele verskaffers wend hulle tot die plaaslike oop woud wat ver van hulle huise geleë is, en plaas sodoende heelwat druk op vervoerstelsels. Die enigste manier waarop Tsumeb sy huidige energie-onsekerheid te bowe kan kom, is deur nuwe benadering tot houtbrandstof in te stel. Om beleid met betrekking tot die ontwikkeling van houtbrandstof doeltreffend toe te pas, moet plaaslike omstandighede sowel Die enigste manier waarop Tsumeb sy huidige energie-onsekerheid te bowe kan kom, is deur nuwe benadering tot houtbrandstof in te stel. Om beleid met betrekking tot die ontwikkeling van houtbrandstof doeltreffend toe te pas, moet plaaslike omstandighede sowelDie enigste manier waarop Tsumeb sy huidige energie-onsekerheid te bowe kan kom, is deur nuwe benadering tot houtbrandstof in te stel. Om beleid met betrekking tot die ontwikkeling van houtbrandstof doeltreffend toe te pas, moet plaaslike omstandighede sowel Die enigste manier waarop Tsumeb sy huidige energie-onsekerheid te bowe kan kom, is deur nuwe benadering tot houtbrandstof in te stel. Om beleid met betrekking tot die ontwikkeling van houtbrandstof doeltreffend toe te pas, moet plaaslike omstandighede sowel as die plaaslike vloei van houtbrandstof dus beter begryp word; moet inisiatiewe op voetsoolvlak tot stand gebring word, en moet gemeenskapsdeelname aangemoedig word. Sodoende sal die mense van Tsumeb – huishoudings, owerhede én ondernemings – gesamentlik kan reageer op kwessies wat hul bestaan beïnvloed en bedreig.

Urban-scale Material Flow Analyses (MFAs) in the global south provide unique challenges compared to national MFAs and to urban MFAs in the north. In order to determine the feasibility of undertaking an urban-scale MFA in the global south, this dissertation sets out to undertake an MFA on Cape Town, and thoroughly analyze the data collection process, document the challenges, and interpret data quantity and quality. Data were found for nearly all flows defined in the Eurostat methodology, but only for the most recent of three consecutive years under study. Data quality is challenged by high variance in reliability of sources, difficulty in obtaining documents, additional work required to process the data, lack of data on informal or illegal flows, and the scattered distribution of sources. Data collection took 345 hours during a period of 22 weeks and involved interaction with a total of 325 contacts and 86 documents. The principal activities were related to contacting and interacting with people. Most time was spent on e-mailing and meeting people, and significant time was furthermore spent on transportation to and from meetings. Not all time was spent effectively and efficiently. Chasing unreliable data and unproductive cross-checking were the principal culprits. Despite the challenges, the quantity and quality of data are of a sufficient level to provide interesting insights into the urban metabolism for Cape Town, and undertaking this kind of urban-scale MFA is thus deemed feasible. Once a time-consuming, initial MFA has identified valuable and reliable sources, periodic repetition should be relatively uncomplicated. Through government involvement or industry cooperation, data collection and data sharing with a few key stakeholders can make regular urban MFA reporting a feasible reality. This work shows who those key stakeholders are and how researchers and government can undertake and improve future urban MFA studies - not only on Cape Town but also on other regions and cities in South Africa. This MFA feasibility study furthermore provided useful insight into the metabolism of Cape Town. For 2013, local extraction was 1.53 t per capita, mostly consisting of non-metallic minerals mined within the borders of Cape Town. Wild fish catch is half of the biomass extraction. Imports and exports were 4.04 t and 2.15 t per capita, respectively, with food and fossil fuels weighing heavily on the imports. The exports are dominated by processed foods and products from the manufacturing industry. Emissions to air can be contrasted with the results from Gasson (2007). Significant per-capita emission increases are seen for CO2 , coupled with decreases for most other emissions to air. Compared to other Eurostat-based urban studies on cities in Western Europe, Cape Town resource flows are significantly lower on a per-capita basis.

In an increasingly globalized world with more and more distributed international supply chains, sustainability studies and policies need to consider socioeconomic and environmental interactions between distant places. Studies of the global biomass metabolism investigate physical flows between and within nature and human systems, thus providing a useful basis for understanding the interrelatedness of changes in one place with impacts elsewhere. Various methodological approaches exist for studying the human-nature metabolism and estimating the land embodied in international trade flows, a core element of assessing telecouplings in the global land system. The results of recent studies vary widely, lacking robustness and thus hampering their application in policy making. This article provides a structured overview and comparative evaluation of existing accounting methods and models for calculating land footprints. We identify differences in available accounting methods and indicate their shortcomings, which are mainly attributable to the product and supply chain coverage and detail, and biases introduced by the use of monetary flows as a proxy for actual physical flows. We suggest options for further development of global land footprint accounting methods, particularly highlighting the advantages of hybrid accounting approaches as a framework for robust and transparent assessments of the global displacement of land use.

Composite materials have become viable alternatives to traditional engineering materials for many different product categories. Liquid transfer moulding (LTM) processes, specifically resin transfer moulding (RTM), is a cost-effective manufacturing technique for creating high performance composite parts. These parts can be tailor-made to their specific application by optimizing the properties of the textile preform. Preforms which require little or no further assembly work and are close to the shape of the final part are critical to obtaining high quality parts while simultaneously reducing labour and costs associated with other composite manufacturing techniques. One type of fabric which is well suited for near-net- shape preforms is stitched non-crimp fabrics. These fabrics offer very high in-plane strength and stiffness while also having increased resistance to delamination. Manufacturing parts from these dry preforms typically involves long-scale fluid flow through both open channels and porous fibre bundles. This thesis documents and analyzes the flow of fluid through preforms manufactured from non-crimp fabrics featuring through-thickness stitches. The objective of this research is to determine the effect of this type of stitch on the RTM injection process. All of the tests used preforms with fibre volume fractions representative of primary and secondary structural parts. A series of trials was conducted using different fibre materials, flow rates, fibre volumes fractions, and degrees of fibre consolidation. All of the trials were conducted for cases similar to RTM. Consolidation of the fibres showed improvements to both the thoroughness of the filling and to the fibre volume fraction. Experimentally determined permeability data was shown to trend well with simple models and precision of the permeability data was comparable to values presented by other authors who studied fabrics which did not feature the through-thickness stitches.

CIVINS
Approved for public release; distribution is unlimited
OpenProp is an open source propeller and turbine design and analysis code that has been in development since 2007 by MIT graduate students under the supervision of Professor Richard Kimball. In order to test the performance predictions of OpenProp for axial flow hydrokinetic turbines, a test fixture was designed and constructed, and a model scale turbine was tested. Tests were conducted in the MIT water tunnel for tip speed ratios ranging from 1.55 to 7.73. Additional code was also written and added to OpenProp in order to implement ABS steel vessels rules for propellers and calculate blade stress. The blade stress code was used to conduct a fatigue analysis for a model scale propeller using a quasi-steady approach. Turbine test results showed that OpenProp provides good performance predictions for the ondesign operational condition but that further work is needed to improve performance predictions for the off-design operational condition. Fatigue analysis results show that reasonable estimates of propeller blade fatigue life can be obtained using a relatively simple method.

Siemens Industrial Turbomachinery AB (SIT) is a company that produces and delivers medium sized industrial gas turbines to customers all over the world and is located in Finspång. The Service section of SIT handles the aftermarket of turbines with both planned and unplanned inspections/repairs. SIT-Service experience that their lead time to customers is too long and a yearly survey with customers confirmed this. Service strives for a higher customer service and since the company suspect that internal processes have safety time built into can time quickly build up. Service has different service lines depending on what kind of maintenance needed and if planned/unplanned. Different options in a combination with several departments involved in these big projects make the flow hard to visualize and makes it complex.This report has studied how SIT-Service can enable a lead time reduction from order to delivery where the flow for Parts was chosen to be mapped and analyzed for one of the service lines. This orientation of the study was partly based on directions from the company and partly delimitations by the writers of the report. Directions from the company were for example to investigate a standard scope and to visualize the flow by mapping it, all with a focus on lead time. Delimitations developed to exclude sales and transportations as well as to only investigate one turbine type and one service line. To be able to follow the flow was a decision made to investigate the flow for Parts.The study has mapped times and activities in the Parts flow from received purchase order (PO) from customer to when parts are ready to leave SIT Finspång. This mapping includes several departments and several transactions in the ERP-system, activities, tasks, queues and uncertainties. The mapping investigated how the lead time was built up by the system and one angle of the mapping was to investigate if the times in the system were consistent with the matching times in reality. To be able to suggest any changes in the Parts flow regarding lead time, the mapping was classified based on value-adding/non-value-adding, wastes, critical chain and bottlenecks. This was followed by a use of different principles in how to enable lead time reduction. These principles were: elimination, simplification, parallelization and a combination of critical chain and bottlenecks.The results and conclusions based on the two analysis parts have been divided into two parts where suggestions in the first one are believed to have a larger impact on the total lead time. This part consists of five big areas of time with several suggestions, from concrete to more general. One of the most important areas is that SIT needs to improve how the company uses the Planned delivery time; to standardize and to make sure that it is used in the same way by all involved which could eliminate unnecessary times built in. Another important area is that the Goods receiving process time could be reduced for a majority of material in the ERP-system since this differs today even if material is handled the same in reality. The second part consisting of 14 smaller areas of suggestions are believed to have a smaller impact on the total lead time but are still considered to be important to implement. All suggestions have an order of implementation which recommends what should be done first for SIT-Service. If the suggestions are implemented is it believed that SIT-Service can shorten the lead time in the Parts flow and also to get a more efficient organization.

Fluidized bed technology is used for thermal conversion of solid fuels (combustion and gasification) and is especially suitable for conversion of low-rank fuels such as biomass and waste. The performance of fluidized bed units depends on the fuel mixing and fuel-gas contact. Thus, it is important to understand these two phenomena in order to develop models for reliable design and scale up of fluidized bed units. This work investigates, under conditions representative for industrial fluidized bed units, the lateral fuel mixing (in a unit with a cross section of 1.44 m2 both at hot and cold conditions) and the bubble flow distribution (in a 1.2 m-wide 2-dimensional unit). The work confirms previous findings on the formation of preferred bubble paths and shows that these bubble paths are enhanced by lowering the fluidization velocity, increasing the dense bed height and reducing the pressure drop across the gas distributor. From the fuel mixing experiments, an estimation of the lateral effective dispersion coefficient to values in the order of 10-3 m2/s is obtained under both hot and cold conditions. The experiments under cold conditions give additional qualitative information on the fuel mixing patterns such as flotsam/jetsam tendencies. The camera probe developed for fuel tracking under hot conditions enables to study the fuel dispersion under real operation at relevant industrial scales. Based on the characteristics of the bubble path flow, a model for the horizontal fuel dispersion on a macroscopic scale is formulated and shown to be able to give a good description of the experimental data. As opposed to the commonly applied diffusion-type modeling of the lateral solids dispersion, the proposed model facilitates integration with models of the bubble flow. Thus, the present modeling work is a first step to provide a modeling of the fuel dispersion, which uses as inputs only the main operational parameters of the fluidized bed.

This thesis presents the derivation of the theory leading to the determination of the governing equations of chemically reacting flows under local thermodynamic equilibrium, which rigorously takes into account effects of elemental (de)mixing. As a result, new transport coefficients appear in the equations allowing a quantitative predictions and helping to gain deeper insight into the physics of chemically reacting flows at and near local equilibrium. These transport coefficients have been computed for both air and carbon dioxide mixtures allowing the application of this theory to both Earth and Mars entry problems in the framework of the methodology for the determination of the catalytic activity of Thermal Protections Systems (TPS) materials.

Firstly, we analyze the influence of elemental fraction variations on the computation of thermochemical equilibrium flows for both air and carbon dioxide mixtures. To this end, the equilibrium computations are compared with several chemical regimes to better analyze the influence of chemistry on wall heat flux and to observe the elemental fractions behavior along a stagnation line. The results of several computations are presented to highlight the effects of elemental demixing on the stagnation point heat flux and chemical equilibrium composition for air and carbon dioxide mixtures. Moreover, in the chemical nonequilibrium computations, the characteristic time of chemistry is artificially decreased and in the limit the chemical equilibrium regime, with variable elemental fractions, is achieved. Then, we apply the closed form of the equations governing the behavior of local thermodynamic equilibrium flows, accounting for the variation in local elemental concentrations in a rigorous manner, to simulate heat and mass transfer in CO2/N2 mixtures. This allows for the analysis of the boundary layer near the stagnation point of a hypersonic vehicle entering the true Martian atmosphere. The results obtained using this formulation are compared with those obtained using a previous form of the equations where the diffusive fluxes of elements are computed as a linear combination of the species diffusive fluxes. This not only validates the new formulation but also highlights its advantages with respect to the previous one :by using and analyzing the full set of equilibrium transport coefficients we arrive at a deep understanding of the mass and heat transfer for a CO2/N2 mixture.

Secondly, we present and analyze detailed numerical simulations of high-pressure inductively coupled air plasma flows both in the torch and in the test chamber using two different mathematical formulations: an extended chemical non-equilibrium formalism including finite rate chemistry and a form of the equations valid in the limit of local thermodynamic equilibrium and accounting for the demixing of chemical elements. Simulations at various operating pressures indicate that significant demixing of oxygen and nitrogen occurs, regardless of the degree of nonequilibrium in the plasma. As the operating pressure is increased, chemistry becomes increasingly fast and the nonequilibrium results correctly approach the results obtained assuming local thermodynamic equilibrium, supporting the validity of the proposed local equilibrium formulation. A similar analysis is conducted for CO2 plasma flows, showing the importance of elemental diffusion on the plasma behavior in the VKI plasmatron torch.

Thirdly, the extension of numerical tools developed at the von Karman Institute, required within the methodology for the determination of catalycity properties for thermal protection system materials, has been completed for CO2 flows. Non equilibrium stagnation line computations have been performed for several outer edge conditions in order to analyze the influence of the chemical models for bulk reactions. Moreover, wall surface reactions have been examined, and the importance of several recombination processes has been discussed. This analysis has revealed the limits of the model currently used, leading to the proposal of an alternative approach for the description of the flow-surface interaction. Finally the effects of outer edge elemental fractions on the heat flux map is analyzed, showing the need to add them to the list of parameters of the methodology currently used to determine catalycity properties of thermal protection materials.
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished

碩士
中原大學
國際貿易研究所
98
Petrochemical industry is an important basic industry for nations which is also capital and energy intensive industry. It has a deep and wide industrial connections from petroleum and gas refinery, chemical materials, man-made fiber, clothing, plastic, synthetic rubber, fertilizer, cleaner, and other industries. The important relationships cover almost consumer products including clothing, food, living transportation, exercise, and leisure that in turn have a greater impact on macroeconomics. Comparing to other industries, petrochemical industry uses more energy and creates more pollution. As a result, how to use resources more effective, to reduce the resource consumption, and to increase resource recycling, and to reduce waste pollution become an important topic. This research is based on the production and energy consumption of Taiwan’s petrochemical materials to understand the current usage of petrochemical resources and energy through material flow analysis. This research use the industrial eco model built by Graedel and Allenby in 1995 and modify the model into five stages of petrochemical eco model and refer to the graphics, symbols, and calculate formula in “The Taiwan Petrochemical Industry Eco Research”done by Chang Tze Hui in 2002. That research included upstream material management stage, midstream material management stage, downstream material management stage, consumption stage, and resource recycling stage. Finally, this research conduct three contexts of material flow analysis to compare the differences in regression result under different contexts and to explore the reasons. Besides, this research conduct life cycle assessment of petrochemical industry an compare it with material flow analysis. This research found that the analysis use an ethylene equivalent yield is better than others. Due to the common units of measurement reduce the duplication of opportunity. The material flow analysis and life cycle assessment resource are similar and their trends in graph are the same too.

碩士
國立臺北大學
自然資源與環境管理研究所
97
The major subject is programing and applicable via the material flow input and output analyze structure for energy exploitation in Taiwan.First,to correct the material flow and up-date the database.And the point of discussing in energy input.Second,to estimate the energy input via the material flow and input-output analysis at all departments in Taiwan. To combine the environmentally extended table and energy balance sheet to measure the output of pollutant. And then,to extend the conception of biomass conversion account the renewable energy materials. Final,to categorize the material flow and economic index appear the relation with energy input and national income. The reserch found the most output is industrial department of a million unit. It nearly discharge 91 metric tons of Domestic Process Output (DPO).The most output is industrial department of 107 kilocalories.It nearly discharge 14 metric tons of Domestic Process Output (DPO).Until 2007,the renewable energy materials appear slowly raise. In 2007, it nearly discharges 9 million metric tons of the renewable energy about 1% of TMR. This research gathers together the indicator of material flow (DMI) and economic development (GDP).They are positive relation.

博士
國立臺灣大學
環境工程學研究所
106
Material flow analysis (MFA) is a one of the methods that depict and assess the flows and stocks of materials in the anthroposphere and the environment for sustainable environmental management. However, MFA results may contain uncertainties arising from the investigation method, calculation processes, data quality, data sources, or research assumptions. Uncertainty has already become an important consideration in material management; for example, Life Cycle Analysis (LCA) has prompted research discussions related to the uncertainty in databases, investigative periods and characteristic factors. Thus, the uncertainty in the MFA is increasingly important to policy makers coping with resources management issues. However, few studies have addressed the uncertainty in the MFA. Moreover, material management issues are not limited to pollution problems that gain much attention from environmental management fields in recent year. The material management stress may come from low resource use efficiency or huge resource consumption. Thus, it is necessary to establish the procedure of combining material management and policy instituted process for strategy-making on environmental management. This research contains two main objectives. The first objective is to perform uncertainty analysis on the data sets of different materials in the MFA by using two important uncertainty analysis methods, i.e. the Hedbrant and Sӧrme (HS) method and the Monte Carlo (MC) simulation method, and the analytical results of the two methods are compared. The second objective is to explore materials management strategies for providing suggestions on sustainable environmental management, in which the procedure of combining material management with policy instituted process is established and an integrated material management policy of phosphorus, nitrogen, copper, cement and lead is made. The research results are presented in two parts: the comparative results of the two uncertainty methods implemented in the MFA methodology; and the suggestions on material management policy. The uncertainty analysis results of the HS method and the MC simulation show that uncertainty range and likely values of flow data can vary considerably. After analyzing the relationship among the uncertainty range, flow data and likely values, which can be derived from the comparisons among the calculation processes of each method, the results of uncertainty analyses show that the HS method may greatly deviate from those of the MC simulation. Under this scenario, the MC simulation needs to analyze the uncertainty in the MFA, although it requires great efforts. For understanding the uncertainty range more precisely, it is suggested to identify the sensitive factor or flow based on uncertainty results. The results of material management policy indicate that the policy instituted process can also be presented right after the procedure of material management is established. This research adopts the concept of LCA to present the material management policy in every process. Furthermore, this research suggests that these management strategies should be divided into short-, medium- and long-term ones for the purpose of easier implementation. Finally, this research also adopts cement as a case study to compare the policy-decision results by quantifying the uncertainty range of its material flow. The results indicate that policy decisions can be made more adequately when both uncertainty range and likely values are considered. This research not only discusses uncertainty issues in the material flow analysis field but also extends the research area to resources management issues. The research results provide new insights and recommendations for further studies on material flow analysis, environmental management and resources management.

碩士
國立清華大學
工業工程與工程管理學系
90
The purposes of this research include 1) establishing a performance index system for analysis of key components material flow and material moving line; 2) analyzing the material flow efficiency for notebook computer manufacturing plants; and 3) thus providing specific improvement recommendation to the factory. The research used 4 major notebook computer factories in Taiwan as the target for study. LCD is used as the key component under study. Contribution of this study include: 1) Establishing key component flow performance index module; 2) Benchmarking performance for the participating plants; 3) Conducting inefficiency analysis; and 4) Providing feedback recommendations to the plants, 5) Study material moving line on target plant for establishing .material moving line planning model and providing improving commendation.

This is a research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2016
The purpose of this study is the demonstration of the effectiveness of material flow analysis (MFA) for decision making in waste management in achieving an integrated solid waste management system. Solid waste generation is a universal human activity. The increase in the scale of economic activities in developing areas has led to a significant increase in the volume of waste generated. The eco-system has a limited capacity for waste absorption; hence inappropriately managed solid waste tends to cause health risks to humans and is associated with ecological degradation. This study analysed the material flows of the municipal solid waste deposited at Robinson Deep landfill situated in the City of Johannesburg (CoJ). Material flow analysis is the tool adopted in providing a holistic characterization of the municipal solid waste and also used as a means of generating optimized management solutions. MFA is based on mass balance principle which states that mass can neither be created nor destroyed. Mathematical modelling and simulations are carried out as the tool to performing the material flow analysis. A situational model (status- quo) which is the actual flow of materials through the landfill site was developed and compared to four scenarios developed in order to evaluate the performance of the waste management system regarding the waste management goals. The scenarios developed showed that they all comply much better with the waste management goals as compared to the status quo. Scenarios 4, comprising a mechanical biological treatment facility and a waste to energy technology and scenario 2 which ensures that all recyclable materials are recovered before landfilling showed to be the favourable options which significantly divert most of the hazardous and valuable materials to the appropriate sinks and recycling processes. Scenario 2 however ensures a more sustainable approach overall but it is an extensive approach. The cost implication of both scenarios are however high. This study was able to show that with the use of MFA, the sources of waste generation, composition of waste deposited on the landfill and the ratio of recycling and total volume of waste diverted from being landfilled can be tracked. This study however recommends further research in tracking the municipal solid waste right from the point generation to the point it is landfilled or recycled using MFA for the whole City of Johannesburg.
MT 2018

A granular material is a collection of discrete, solid particles of macroscopic size dispersed in an interstitial fluid, in which the fluid has an insignificant effect on the particle dynamics. Because they exhibit fascinating properties because of dissipative interactions, due to their importance in geophysical and industrial processes, flows of granular materials have been the focus of large amount of research involving physicists and engineers. A good understanding of the physics of granular materials is desired in order to design efficient processing and handling systems. Granular materials can be heaped like a solid, and can flow like a fluid. Though the two distinct regimes of granular flows are well described by kinetic theory (rapid flows) and plasticity theories (quasi-static), the intermediate dense flow regime, where collisional and frictional interactions are important, is not yet described successfully. In this thesis, we examine the applicability of kinetic theory for dense granular flows, the structure and dynamics in sheared inelastic hard disks systems and dynamics of sheared non-spherical particles. Two complementary simulation techniques, the discrete element (DE) technique for soft particles and the event driven (ED) simulation technique for hard particles, are used to examine the extent to which the dynamics of an unconfined dense granular flow can be well described by a hard particle model when the particle stiffness becomes large. First, we examine the average co-ordination number for the particles in the flow down an inclined plane using the DE technique using both linear and Hertzian contact models. The simulations show that the average co-ordination number decreases below 1 for values of the spring stiffness corresponding to real materials such as sand and glass, even when the angle of inclination is only 1olarger than the angle of repose. The results of the two simulation techniques for the Bagnold coefficients (ratio of stress and square of the strain rate) and the granular temperature (mean square of the fluctuating velocity) are found to be in quantitative agreement. In addition, we also conduct the comparison of the pre-collisional relative velocities of particles in contact. Since momentum is transported primarily by particle contacts in a dense flow, the relative velocity distribution is a sensitive comparison of the dynamics in the two simulation techniques. It is found that the relative velocity distribution in both simulation techniques are well approximated by an exponential distribution for small coefficients of restitution, indicating that the dynamics of a dense granular flow can be adequately described by a hard particle model. The structure and dynamics of the two-dimensional linear shear flow of inelastic disks at high area fractions are analysed. The event-driven simulation technique is used in the hard-particle limit, where the particles interact through instantaneous collisions. The structure (relative arrangement of particles) is analysed using the bond-orientational order parameter. It is found that the shear flow reduces the order in the system, and the order parameter in a shear flow is lower than that in a collection of elastic hard disks at equilibrium. The distribution of relative velocities between colliding particles is analysed. The relative velocity distribution undergoes a transition from a Gaussian distribution for nearly elastic particles, to an exponential distribution at low coefficients of restitution. However, the single-particle distribution function is close to a Gaussian in the dense limit, indicating that correlations between colliding particles have a strong influence on the relative velocity distribution. This results in a much lower dissipation rate than that predicted using the molecular chaos assumption, where the velocities of colliding particles are considered to be uncorrelated. The orientational ordering and dynamical properties of the shear flow of inelastic dumbbells in two dimensions are studied, as a first step towards examining the effect of shape on the properties of flowing granular materials. The dumbbells are smooth fused disks characterised by the ratio of the distance between centers (L) and the disk diameter (D), and the ratio (L/D)varies between 0 and 1 in our simulations. Area fractions studied are in the range 0.1 to 0.7, while coefficients of normal restitution from 0.99 to 0.6 are considered. The simulations are similar to the event driven simulations for circular disks, but the procedure for predicting collisions is much more complicated due to the non-circular shape of the particles and due to particle rotation. The average orientation is measured using an orientational order parameter S, which varies between 0 (for a perfectly disordered fluid) and 1 (for a fluid with the axis of all dumbbells in the same direction). It is found that there is a gradual increase in ordering as the area fraction is increased, as the aspect ratio is increased or as the coefficient of restitution is decreased, and the order parameter has a maximum value of about 0.5 for the highest area fraction and lowest coefficient of restitution considered here. However, there is no discontinuous nematic transition for all the parameters studied here. The axis of the dumbbells are preferentially oriented along the extensional axis (at an angle of 45ofrom the flow direction) at low area fraction, but the orientation is closer to the flow direction as the area fraction is increased. The orientation distribution is calculated, and it is found that the orientation distribution is well described by a function of the form P(θ) =(1/π)+ (2S/π)cos(2(θ−θp)), where θis the angle from the flow direction and θpis the principal orientation direction. The mean energy of the velocity fluctuations in the flow direction is found to be higher than that in the gradient direction and the rotational energy, though the difference decreases as the area fraction increases, due to the efficient collisional transfer of energy between the three directions. The distributions of the translational and rotational velocity are found to be Gaussian distributions to a very good approximation. The equation of state for the pressure is calculated, and it is found to be remarkably independent of the coefficient of restitution. The pressure and dissipation rate show relatively little variation when scaled by the collision frequency for all the area fractions studied here, indicating that the collision frequency determines the momentum transport and energy dissipation even at the lowest area fractions studied here. The mean angular velocity of the particles is examined in some detail. It is found that the mean angular velocity is equal to half the vorticity at low area fractions, but the magnitude of the mean angular velocity systematically decreases to less than half the vorticity as the area fraction is increased, even though the stress tensor is symmetric.