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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Consumption-based material flow indicators - Comparing six ways of calculating the Austrian raw material consumption providing six results

Eisenmenger, Nina, Wiedenhofer, Dominik, Schaffartzik, Anke, Giljum, Stefan, Bruckner, Martin, Schandl, Heinz, Wiedmann, Thomas, Lenzen, Manfred, Tukker, Arnold, Arjan, de Koning January 2016 (has links) (PDF)
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.
52

Measuring telecouplings in the global land system: A review and comparative evaluation of land footprint accounting methods

Bruckner, Martin, Fischer, Günther, Tramberend, Sylvia, Giljum, Stefan 23 March 2015 (has links) (PDF)
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.
53

Uplatnění logistiky v období povodní ve vybrané lokalitě / Use of logistics during floods in the chosen locality

PETRÁSEK, Martin January 2016 (has links)
The main objective of this thesis was analyzing material and information flow during floods in the chosen company. I have chosen company JITEX Písek a.s., which had to face to huge flood in year 2002. The sub-objective was found options of improvement in these flows, which are described in conclusion of this thesis. For gain of important information were used structured interviews with the managers of JITEX like Technical Director and Production Manager. On the basis of the data was a detailed description of the information and material flow and measures, which the company had to accept. Follow evaluation of the impact of the floods on other business activity.
54

Análise do fluxo de material no processo de soldagem por fricção com pino consumível

Landell, Renan Mensch January 2016 (has links)
Em substituição aos processos de reparo de defeitos por soldagem por arco elétrico, a Soldagem por Fricção com Pino Consumível ou Friction Hydro Pillar Processing (FHPP) vem sendo estudada devido a suas diversas vantagens sobre os processos convencionais de reparo. Isso se deve a não ocorrência de fusão do metal base e do metal de adição, ao reduzido tempo de processamento (inferior a um minuto, na maioria dos casos) e à possibilidade de automação do processo. Entretanto, por ser um processo relativamente novo, pouco se sabe sobre o mecanismo de deposição de material e a influência deste na qualidade final da junta soldada. Desta forma, a análise do fluxo de material proposta por esse estudo visa contribuir na compreensão da distribuição do material no interior da junta soldada. Para isso, um traçador de titânio foi inserido no interior da solda de um pino de aço SAE 4140. Para a avaliação das juntas soldadas com o traçador de titânio, foram feitas análises de macro e micrografia, além da análise por raios X por meio de um tomógrafo industrial. A partir dos resultados, constatou-se que o processo de FHPP apresenta dois fluxos distintos: o primeiro relativo à distribuição de material do centro do pino, já o segundo referente à distribuição de material da parede do pino. O material do centro do pino tem a tendência de acumular-se no fundo da solda e por meio dos planos de cisalhamento criados, o material do centro do pino é transportado para a periferia do pino. Já o segundo fluxo de material ocorre entre as superfícies de contato do pino e do furo. É um escoamento de expulsão de material, sendo expulso com a rebarba. Ainda, foi verificado que a mistura de material ocorre somente nas regiões onde há atrito entre as peças: ponta do pino com o fundo do furo, parede do pino com a parede do furo e no plano de cisalhamento a quente. Portanto, a partir do conhecimento do fluxo de material é possível prever a distribuição de particulados no interior da solda, uma vez que elas tendem a se acumular nas regiões com maior intensidade de fluxo. Além disso, a utilização da técnica de tomografia computacional mostrou-se eficaz na identificação de trincas no interior de juntas soldadas por fricção e também para as análises de fluxo em soldas com materiais dissimilares. / The replacement of electric arc welding at cracks repairs by the Friction Hydro Pillar Processing (FHPP) it`s being studied due the several advantages of this new process. With the FHPP the process time is less than one minute, the welding temperature is bellow to the melting temperature of the material and the process can be automated. However, as it is a relatively new repair welding process, there are not many information about the material distribution mechanism and the influence of it at the final weld quality. Thus, the material flow analysis proposed by this study intends to contribute to the material comprehension distribution inside the weld. Therefore, a titanium tracer was inserted inside a SAE 4140 steel pin. To evaluate the welds, the samples were analyzed by metallography and by industrial tomography. With the results, were found two different materials flows. The first describes the flow of the material at the center of the pin and the second describes the flow of the material of the faying surface of the pin. The material at the center of the pin tends to accumulate at the bottom of the weld and just above this few volume, appears the hot shear plane that allow the material from the center of the pin flows intermittent to the periphery. Nevertheless, this material is not expelled with the flash. The second flow is the material of the faying surface outside of the center pin, which on part goes to the top of the weld and it is expelled with the flash, and the other goes to the bottom of the weld, but doesn’t arrives because of the material already deposited. Furthermore, it was verified that the material stir occurs specially at the regions that the friction happens: faying surface of the pin and the hole and the shear plane. Thus, with that information it is possible to predict the distribution of particulate, as inclusions, inside the weld. Besides that, the industrial tomography proved that is able to identify cracks inside the welds and it is a great tool at the flow analysis of dissimilar welds.
55

Zlepšování logistických postupů ve výrobě / Process improvement of logistic in the production

SUCHÁNKOVÁ, Hedvika January 2008 (has links)
My diploma work is focussed on the organisation of materials flow in a selected enterprise. In the frame of the studied enterprise I devoted special attention to the flow of packaging and manufacturing materials demonstrated on the operations of a particular manufacturing hall. Based on the implemented analysis the enterprise management decided to optimise the unsatisfying state of processes in compliance with the principles of lean production. The described re-structuring was aimed at a decrease in the stock of finished products packed in boxes and in an increased efficiency of responds to potential client requirements, further at specification of rules and setting responsibilities in the fields of logistics and manufacturing. The concluding section of the diploma work is focussed on potential improvement measures which could be taken within the studied enterprise.
56

Analýza hlavních materiálových toků ve firmě / Analysis of the main material flows in the company

MRÁZ, Petr January 2009 (has links)
The aim of my thesis was to analysis the material flow in the company Prym Consumer CZ s.r.o. In the thesis I have described relations with suppliers, which is worth mentioning a consignment stock. Most I have focused on the evaluation of stock control {--} from the description of stores, to draft their own inventory management.
57

Logistické zajištění výroby kovových profilů / Logistics metal production analysis

CHOCHOLATÝ, Viktor January 2008 (has links)
Material flow analysis is a main goal of the thesis. To analyse the flows of a material in a well-defined system under study. The goal is to get a transparent understanding of the material flows, to calculate indicators and to develop strategies and measures for improving the material flow systems. Material Flow Analysis thus is the basis for a material flow management.
58

Análise do fluxo de material no processo de soldagem por fricção com pino consumível

Landell, Renan Mensch January 2016 (has links)
Em substituição aos processos de reparo de defeitos por soldagem por arco elétrico, a Soldagem por Fricção com Pino Consumível ou Friction Hydro Pillar Processing (FHPP) vem sendo estudada devido a suas diversas vantagens sobre os processos convencionais de reparo. Isso se deve a não ocorrência de fusão do metal base e do metal de adição, ao reduzido tempo de processamento (inferior a um minuto, na maioria dos casos) e à possibilidade de automação do processo. Entretanto, por ser um processo relativamente novo, pouco se sabe sobre o mecanismo de deposição de material e a influência deste na qualidade final da junta soldada. Desta forma, a análise do fluxo de material proposta por esse estudo visa contribuir na compreensão da distribuição do material no interior da junta soldada. Para isso, um traçador de titânio foi inserido no interior da solda de um pino de aço SAE 4140. Para a avaliação das juntas soldadas com o traçador de titânio, foram feitas análises de macro e micrografia, além da análise por raios X por meio de um tomógrafo industrial. A partir dos resultados, constatou-se que o processo de FHPP apresenta dois fluxos distintos: o primeiro relativo à distribuição de material do centro do pino, já o segundo referente à distribuição de material da parede do pino. O material do centro do pino tem a tendência de acumular-se no fundo da solda e por meio dos planos de cisalhamento criados, o material do centro do pino é transportado para a periferia do pino. Já o segundo fluxo de material ocorre entre as superfícies de contato do pino e do furo. É um escoamento de expulsão de material, sendo expulso com a rebarba. Ainda, foi verificado que a mistura de material ocorre somente nas regiões onde há atrito entre as peças: ponta do pino com o fundo do furo, parede do pino com a parede do furo e no plano de cisalhamento a quente. Portanto, a partir do conhecimento do fluxo de material é possível prever a distribuição de particulados no interior da solda, uma vez que elas tendem a se acumular nas regiões com maior intensidade de fluxo. Além disso, a utilização da técnica de tomografia computacional mostrou-se eficaz na identificação de trincas no interior de juntas soldadas por fricção e também para as análises de fluxo em soldas com materiais dissimilares. / The replacement of electric arc welding at cracks repairs by the Friction Hydro Pillar Processing (FHPP) it`s being studied due the several advantages of this new process. With the FHPP the process time is less than one minute, the welding temperature is bellow to the melting temperature of the material and the process can be automated. However, as it is a relatively new repair welding process, there are not many information about the material distribution mechanism and the influence of it at the final weld quality. Thus, the material flow analysis proposed by this study intends to contribute to the material comprehension distribution inside the weld. Therefore, a titanium tracer was inserted inside a SAE 4140 steel pin. To evaluate the welds, the samples were analyzed by metallography and by industrial tomography. With the results, were found two different materials flows. The first describes the flow of the material at the center of the pin and the second describes the flow of the material of the faying surface of the pin. The material at the center of the pin tends to accumulate at the bottom of the weld and just above this few volume, appears the hot shear plane that allow the material from the center of the pin flows intermittent to the periphery. Nevertheless, this material is not expelled with the flash. The second flow is the material of the faying surface outside of the center pin, which on part goes to the top of the weld and it is expelled with the flash, and the other goes to the bottom of the weld, but doesn’t arrives because of the material already deposited. Furthermore, it was verified that the material stir occurs specially at the regions that the friction happens: faying surface of the pin and the hole and the shear plane. Thus, with that information it is possible to predict the distribution of particulate, as inclusions, inside the weld. Besides that, the industrial tomography proved that is able to identify cracks inside the welds and it is a great tool at the flow analysis of dissimilar welds.
59

Viabilidade econômica e energética do preparo profundo de solo no cultivo da cana-de-açúcar / Economic and energy viability of deep tillage in sugarcane cultivation

Daniela Cristina de Oliveira 10 October 2017 (has links)
A cana-de-açúcar é a cultura com finalidade energética mais importante do agronegócio brasileiro, por gerar muitos empregos no setor, representar uma parcela significativa do PIB agropecuário e por ser a fonte renovável de energia com maior participação na matriz energética brasileira. O sucesso de seu cultivo depende, dentre outros fatores, da realização do preparo de solo adequado para fornecer às plantas condições favoráveis de desenvolvimento, particularmente do sistema radicular. Em geral, ele é realizado a cada cinco anos e o custo de implantação do canavial, no qual ele se inclui, é alto, representando em torno de 25% desse custo. Os sistemas de preparo de solo comumente utilizados são o convencional e o reduzido, ambos mecanizados. O primeiro tem como característica práticas intensivas de mobilização do solo em camadas mais rasas, enquanto o segundo é composto por número reduzido de operações e máquinas na área e a mobilização do solo pode ser em camadas rasas ou profundas. A escolha pelo sistema de preparo de solo mais econômico e sustentável é complexa por envolver muitas variáveis. Avaliações econômica e energética têm sido uma alternativa eficiente para analisar sistemas de produção agrícola, pois fornecem indicadores financeiros e ambientais para auxiliar na tomada de decisão na adoção do sistema de preparo. Tendo em vista a importância econômica e energética da cana no cenário nacional, a influência do preparo de solo no desenvolvimento da planta e na composição dos custos operacionais, associados à carência de estudos energéticos que avaliem o sistema mecanizado do preparo profundo do solo, este trabalho teve o objetivo de analisar a viabilidade econômica e energética do sistema de preparo de solo profundo no cultivo da cana-de-açúcar em comparação ao sistema convencional. Para tal foi desenvolvido um modelo em planilha eletrônica que auxiliou na determinação dos indicadores econômicos e energéticos de cada sistema de preparo de solo. Os resultados apontaram que o sistema de preparo profundo do solo é viável do ponto de vista econômico e energético, pois apresentou custo operacional de 401,50 R$ ha-1 e demanda de energia de 2,63 GJ ha-1, respectivamente, 30% e 40% inferiores, ao sistema convencional. A análise de sensibilidade evidenciou que a capacidade de campo operacional, a potência do trator e o consumo de combustível foram os fatores de maior impacto na variação dos custos operacionais e na demanda de energia de entrada. / Sugarcane is the most of important energy crop for Brazilian agribusiness, since it propitiates many jobs, it represents a significant share of agricultural GDP and it is the renewable source of energy of higher contribution to the energy matrix. The success of its cropping depends, among other factors, of the appropriate tillage system to provide the plants favorable development conditions, particularly to the root system. Generally, it is carried out on every five years and it accounts around 25% of cropping cost. Soil tillage systems usually adopted are conventional and reduced, both mechanized. The conventional system consists of several operations in the superficial layers, while the reduced one uses less operations and soil mobilization can be in shallow or deep layers. In this latter category, the system of deep soil tillage is included if it is carried out in rows of planting. Economic and sustainable soil preparation system is complex because it involves many variables. Economic and energy assessments have been an efficient alternative to analyze agricultural production systems because it provides financial and environmental indicators for decision making on system adoption. Considering the economic and energy importance of sugarcane in the national scenario, the influence of soil preparation on the development of the plant and the composition of the operational costs, associated to the lack of energy studies that evaluate the mechanized system of deep soil preparation, this study aimed to analyze the economic and energy viability of the deep soil preparation system in sugarcane cultivation compared to the conventional system. For this purpose, a model was developed which assisted in the determination of the economic and energy indicators of each soil preparation system. The results showed that the deep soil preparation system is feasible from an economic and energy point of view, since it presented operational cost of 401.50 R$ ha-1 and energy demand of 2.63 GJ ha-1, respectively, 30% and 40% below the conventional system. Sensitivity analysis showed that the operational field capacity, the power of the tractor, the fuel consumption were the factors presented greater relevance in the variation of operating costs and the demand for input energy.
60

A review and comparative assessment of existing approaches to calculate material footprints

Lutter, Franz Stephan, Giljum, Stefan, Bruckner, Martin 16 April 2016 (has links) (PDF)
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.

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