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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.
41

Proposal for fourth generation of Maintenance and the future trends & challenges in Production

Manickam, Louis rex arun January 2012 (has links)
Maintenance has evolved over centuries and has played significant role for growth of organizations. Maintenance history is differentiated by three generations, the development of maintenance considered from being “necessary evil” to “profit contributor”. Many literatures have discussed maintenance for optimization and increasing profitability but little on the factors which influence on the future of maintenance. Maintenance should be considered as a “competitive factor” in the future. Many trends have evolved in production and every trend had a major contribution towards production development. The successful implementation of the trends is considered to be a major challenge. Little literatures have talked on the emerging trends and challenges in production. The thesis reviews the historical development of maintenance over generations and presents the key factors which play a major role during the fourth generation, and also identifies the emerging trends and challenges to be faced by production. The literature review, interviews and surveys were used in this thesis. Academic researchers and industrial experts from both maintenance and production department answered the interview and survey questions for this research. The key factors for the proposal of fourth generation of maintenance and the emerging trends and challenges to be faced by production are presented. The result from the research questions and the empirical findings are summarized in a framework that will enable readers to know the historical development of maintenance, the key factors to be considered for the fourth generation of maintenance and the emerging trends and challenges to be faced by production in future. In addition, the thesis also discusses the impact of information technology on the future of maintenance and the effect of sustainability in the future of production.
42

Det komplexa valet av leverantör och dess betydelse för företagens framgång : En fallstudie i den svenska modebranschen

Wu, Caroline, Fernström, Sandra January 2015 (has links)
Modeföretagen i Sverige 2015 befinner sig i en mycket konsumentstyrd bransch där trender uppstår och passerar snabbt, vilket ger en bransch som ständigt förser marknaden med nya varor. Mode är samtidigt råvaruintensiv och lämnar ett avtryck i miljön som påverkar alla. Konsumenterna ställer nu allt högre krav på att varor är producerade mer hållbart och under socialt ansvarstagande, CSR, i alla led. Modeföretagen ansvarar för en produktion av varor som främst sker i länder med lägre kostnad för arbetskraft, vilket medför svårigheter i form av kontroll då avstånden är långa. Vilken relation företaget har till sina leverantörer har således kommit att spela en allt mer avgörande roll. Syftet med uppsatsen är att genom en fallstudie undersöka och analysera de överväganden som producerande aktörer på den svenska modemarknaden gör vid val av leverantörer, för att på så sätt belysa de svårigheter de anser finns och vad som är viktigt för deras framgång. Metoden som använts är semistrukturerade intervjuer inom fallstudiens ramar. Sekundärdata har samlats in från press, företagens hemsidor och från mailkorrespondens med branschorganisationer. Fallstudien visar att relationen företagen har till sina leverantörer är väldigt viktig för dess framgång. Ett bra leverantörssamarbete ökar företagens chanser till både hållbar produktion och ger en ökad möjlighet till finansiering genom handelskredit. En bra leverantörsrelation ökar även företagens möjligheter till flexibilitet från leverantörens sida med snabbare leveranser som bättre kan möta kundens efterfrågan och minska risken för felbedömningar. Långa avstånd anses som ett problem för modeföretagen och de söker därför närmare produktion inom EU som ger kortare ledtider, en möjlighet till bättre leverantörsrelationer samt ett underlättande av likvärdiga kemikalielagar.
43

Analysis of changes in eco-efficiency of production and consumption in Lithuania during the 1990 – 2006 year period / Ekologinio gamybos ir vartojimo veiksmingumo pokyčių Lietuvoje 1990 – 2006 m. analizė

Dagiliūtė, Renata 29 December 2008 (has links)
Sustainable production and consumption, as well as decoupling environmental impact from economy growth are one of the main goals for countries with transition economies. Lithuania, as other Central and Eastern Europe (CEE) countries experienced changes in political, social and economic life in relative short time after the collapse of Soviet Union. Because of an essentially reduced production, use of natural resources and environmental pollution decreased respectively. However, present pronounced growth of transition countries and demand for better quality of life could lead to the increase in material and energy consumption. Such increase would have two implications: firstly, increasing pressure on the environment and health in enlarged EU and could outweigh achievements in Western Europe, and secondly, such increase could impede to reach foreseen objectives to decouple resource consumption from economic growth. The aim of the research was to analyze the main trends of production and consumption and their environmental impact in Lithuania and to assess eco-efficiency of production and consumption and its main determinants. Research on eco-efficiency and the course of decoupling of environmental impact from economy growth in Lithuania is relatively rare and is mostly based on energy issues or covers only one sector. In this study, the eco-efficiency of production and consumption in Lithuania is analyzed jointly for the first time. For the better interpretation of ongoing... [to full text] / Darnios gamybos ir vartojimo siekimas, o tuo pačiu ir poveikio aplinkai atsiejimas nuo ekonomikos, yra vienas pagrindinių darnaus vystymosi tikslų pereinamosios ekonomikos šalims. Lietuva, kaip ir kitos posovietinės šalys, po Sovietų Sąjungos griūties paveldėjo imlų ištekliams ir neefektyvų ūkį. Ūkio restruktūrizavimas lėmė transformacinį ūkio nuosmukį ir jį sekusį išteklių naudojimo ir aplinkos teršimo sumažėjimą. Tačiau dabartinis spartus pereinamosios ekonomikos šalių, kurių dauguma jau tapo ES narėmis, augimas ir geresnės gyvenimo kokybės siekimas gali lemti didesnes medžiagų ir energijos sąnaudas, o tai savo ruožtu sąlygotų didėjantį poveikį aplinkai ir žmonių sveikatai išsiplėtusioje Europos Sąjungoje ir atsvertų kai kuriuos ES šalių senbuvių pasiekimus bei trukdytų pasiekti numatytus išteklių naudojimo atsiejimo nuo ekonomikos augimo tikslus. Darbo tikslas - išanalizuoti Lietuvos gamybos, vartojimo ir jų poveikio aplinkai kitimo tendencijas, ekologinio veiksmingumo pokyčius ir nustatyti jį lemiančius veiksnius. Ekologinio veiksmingumo bei poveikio aplinkai atsiejimo nuo ekonomikos augimo tyrimai Lietuvos mastu palyginti mažai vykdyti ir dažnai apsiriboja tik energetinių išteklių naudojimo veiksmingumo analize arba skirti tik atskiriems sektoriams. Darbe pateikiama dvigubo atsiejimo koncepcija, numatanti būtinybę atsieti gamtos išteklių naudojimą nuo ekonomikos augimo ir aplinkos teršimą nuo gamtos išteklių naudojimo bei sudaranti galimybes detaliau įvertinti... [toliau žr. visą tekstą]
44

Ekologinio gamybos ir vartojimo veiksmingumo pokyčių Lietuvoje 1990 – 2006 m. analizė / Analysis of changes in eco-efficiency of production and consumption in Lithuania during the 1990 – 2006 year period

Dagiliūtė, Renata 29 December 2008 (has links)
Darnios gamybos ir vartojimo siekimas, o tuo pačiu ir poveikio aplinkai atsiejimas nuo ekonomikos, yra vienas pagrindinių darnaus vystymosi tikslų pereinamosios ekonomikos šalims. Lietuva, kaip ir kitos posovietinės šalys, po Sovietų Sąjungos griūties paveldėjo imlų ištekliams ir neefektyvų ūkį. Ūkio restruktūrizavimas lėmė transformacinį ūkio nuosmukį ir jį sekusį išteklių naudojimo ir aplinkos teršimo sumažėjimą. Tačiau dabartinis spartus pereinamosios ekonomikos šalių, kurių dauguma jau tapo ES narėmis, augimas ir geresnės gyvenimo kokybės siekimas gali lemti didesnes medžiagų ir energijos sąnaudas bei poveikį žmonių sveikatai, o tai savo ruožtu sąlygotų didėjantį poveikį aplinkai išsiplėtusioje Europos Sąjungoje ir atsvertų kai kuriuos ES šalių senbuvių pasiekimus bei trukdytų pasiekti numatytus išteklių naudojimo atsiejimo nuo ekonomikos augimo tikslus. Darbo tikslas - išanalizuoti Lietuvos gamybos, vartojimo ir jų poveikio aplinkai kitimo tendencijas, ekologinio veiksmingumo pokyčius ir nustatyti jį lemiančius veiksnius. Ekologinio veiksmingumo bei poveikio aplinkai atsiejimo nuo ekonomikos augimo tyrimai Lietuvos mastu palyginti mažai vykdyti ir dažnai apsiriboja tik energetinių išteklių naudojimo veiksmingumo analize arba skirti tik atskiriems sektoriams. Darbe pateikiama dvigubo atsiejimo koncepcija, numatanti būtinybę atsieti gamtos išteklių naudojimą nuo ekonomikos augimo ir aplinkos teršimą nuo gamtos išteklių naudojimo bei sudaranti galimybes detaliau įvertinti... [toliau žr. visą tekstą] / Sustainable production and consumption, as well as decoupling environmental impact from economy growth are one of the main goals for countries with transition economies. Lithuania, as other Central and Eastern Europe (CEE) countries experienced changes in political, social and economic life in relative short time after the collapse of Soviet Union. Because of an essentially reduced production, use of natural resources and environmental pollution decreased respectively. However, present pronounced growth of transition countries and demand for better quality of life could lead to the increase in material and energy consumption. Such increase would have two implications: firstly, increasing pressure on the environment in enlarged EU and could outweigh achievements in Western Europe, and secondly, such increase could impede to reach foreseen objectives to decouple resource consumption from economic growth. The aim of the research was to analyze the main trends of production and consumption and their environmental impact in Lithuania and to assess eco-efficiency of production and consumption and its main determinants. Research on eco-efficiency and the course of decoupling of environmental impact from economy growth in Lithuania is relatively rare and is mostly based on energy issues or covers only one sector. In this study, the eco-efficiency of production and consumption in Lithuania is analyzed jointly for the first time. For the better interpretation of ongoing... [to full text]
45

Uso de boro e palhada no manejo sustentável e produção de citrus [Citrus sinensis (L.) Osbeck / The use of boron and straw for sustainable management and production of citrus [C. sinensis) (L.) Osbeck]

Ronaldo Alberto Duenhas Cabrera 08 October 2007 (has links)
A citricultura paulista está estabelecida, em sua maioria, em solos com baixos teores de matéria orgânica e, em decorrência deste fato, diversos aspectos associados à carência de nutrientes têm sido atribuídos à baixa disponibilidade da matéria orgânica. Para otimização de sistemas agrícolas que priorizem a sustentabilidade recomenda-se, por exemplo, o uso de cobertura morta (palhada), o incremento de matéria orgânica e a melhoria da fertilidade química física e biológica do solo, resultando em aumento de produtividade, maior estabilidade das produções e melhor disponibilidade de água para as plantas. O presente trabalho estudou em condições de campo, durante quatro safras, os efeitos da adição de cobertura morta ("mulch") - 0, 15 e 30 t.ha-1.ano-1 usando a palhada de gramínea Tifton como fonte de cobertura morta e ácido bórico aplicado via solo, nas doses de 0, 6 e 12 kg.ha-1 como fonte de boro. Foram avaliados, além da produtividade (t.ha-1 e número de frutos.ha-1), os aspectos associados à fertilidade de solo, aspectos físicos e nutricionais associados às variações dos tratamentos nos atributos hídricos do solo, a detecção da presença de carbono da palha no solo por metodologia isotópica do δ13c e δ15N, a atividade da biomassa microbiana, a influência dos tratamentos na qualidade do suco e aspectos econômicos quanto ao uso de palhada e boro no sistema produtivo. O experimento foi conduzido no município de Araras-SP, em pomar de laranja 'Pêra', com 9 tratamentos – 3 doses de palhada e 3 doses de boro, 4 repetições e 4 plantas por parcela, totalizando 144 plantas em um pomar comercial de 8 anos. A aplicação de 15 t.ha-1 e 30 t.ha-1 de palhada proporcionaram um aumento de 3,38 t.ha-1 (15,6%) e 8,89 t.ha-1 (41,1%) respectivamente. Em ambos os casos, a aplicação foi inviável economicamente, pois o custo da aplicação da cobertura morta foi maior que a receita do incremento de produtividade. Para o número de frutos.ha-1 a aplicação de palhada incrementou 9,3% e 24,4% para os tratamentos de 15 t.ha-1 e 30 t.ha-1 respectivamente. Na camada de 0 a 20 cm de profundidade, a biomassa microbiana foi ativada na dose de 30 t.ha-1 de palhada, sendo 64,7% superior à testemunha e 46,9% superior à dose de 15 t.ha-1. A aplicação de palhada de gramínea aumentou a participação de carbono de planta C4 na matéria orgânica do solo, sendo que a participação foi de 44%, 54,8% e 60,9%, para as doses de 0, 15 e 30 t.ha-1 respectivamente, mas a aplicação de palhada não afetou as características hídricas do solo nas profundidades de 20 e 40 cm. O efeito da aplicação de boro foi observado somente em ano de alta produtividade, acima de 40 t.ha-1, com a dose de 12 kg.ha-1 produzindo 5,8 t.ha-1 (16,7%) a mais que a testemunha. A relação foliar K/Ca e o teor de foliar de enxofre afetaram negativamente a produtividade, pois para cada unidade que aumenta na relação K/Ca houve diminuição de 30 t. 30 t-1 e para cada unidade de aumento do teor foliar de enxofre ocorreu redução de 4 t.ha-1. Recomenda-se que a relação K/Ca deve estar em torno de 0,4 e o teor foliar de enxofre em torno de 3 g.kg-1, já a relação P/S afetou positivamente a produtividade, para cada unidade que aumenta nesta relação, ocorreu um aumento de 17 t.ha-1. O aspecto ano é um fator importante, onde o efeito da alternância bienal de alta/baixa safra ficou evidente. / The citrus production in the state of São Paulo has been established in its majority, on soils with low organic matter and due to this fact, several aspects related to the lack of nutrients have been attributed to the low availability of organic matter. To introduce a sustainable management for the citrus production system, the producers have been adopted the use of mulch to cover the plants. This practice has proved to increase the soil organic matter content and has been recommended for mid- and long-term improvement of the physical and chemical and biological parameters of the soil, resulting in higher productivity, a better stability in crop production and higher water availability to the citrus plants. This work studied for 4 citrus growing seasons at field conditions the effects of the addition of mulch at rates of 0, 15 and 30 t.ha-1 added every year, using Tifton as source of mulch and boric acidic added to the soil at rates of 0, 6 and 12 kg.ha-1. Measures included yield (t.ha-1 and fruit number.ha-1), the soil nutrient composition, nutritional parameters associated to the physical and chemical variations in the soil due to the treatments, the isotopic δ13c carbon and δ15N nitrogen variation in the soil due to straw addition, the soil microbial biomass, the fruit (juice) quality and the economic aspects involving the use of these two practices – mulch and boron, in the citrus production system. The experiment was set up in Araras, São Paulo State, in a 8-year old commercial orchard of sweet orange var. Pêra, with 9 treatments – 3 rates of mulch and 3 rates of boron, 4 replicates with 4 plants for plot, in a total of 144 plants. The application of 15 t.ha-1 and 30 t.ha-1 of mulch increased 3,38 t.ha-1 (15,6%) and 8,89 t.ha-1 (41.1%) respectively, in both cases the use of mulch showed not to be economically viable, due to its high cost in the market. The fruit productivity from the mulch treatments increased 9.3% and 24.4%, in treatments with mulch added at the rates 15 t.ha-1 and 30 t.ha-1, respectively. At 0-20 cm soil depth, the microbial biomass increased when 30 t.ha-1 mulch was added, with 64.7% and 46.9%, corresponding to 0 t/ha and 15 t.ha-1 mulch, respectively. The use of Tifton grass as mulch was positively related to increases of carbon from C4-plants in the soil organic matter content, with increases after 4 years of growth as high as 44.4%, 54.8% and 60.9%, corresponding to the rates of 0, 15 and 30 t.ha-1 of mulch. Nevertheless, the addition of mulch has not affected the water content of the soil at 20 and 40 cm depth. The effect of boron was observed only at the high productivity season (more 40 t.ha-1), with the treatment of 12 kg t.ha-1 yielding 5.8 t.ha-1 (16.7%), when compared to the control (0 kg/ha B) treatment. The K/Ca ratio and the S-leaf concentration were negatively correlated with yield, when increases of one unit in K/Ca ratio corresponded to a decrease of 30 t.ha-1 and one unit of S-leaf concentration to minus 4 t.ha-1. It is recommended that K/Ca ratio should be around 0.4 and the S-leaf concentration around 3 g/kg. The leaf ratio P/S affected positively the yield, when increases of one unit in this ratio, corresponded to increases of 17 t.ha-1 in yield increases. The season (year) was an important factor, showing an alternate variation of high/low yield in every two years.
46

Hållbar produktion : En analys av energiförbrukning och avfall för minskad miljöpåverkan inom växellådsmontering / Sustainable production : An analysis of energy consumption and waste for reduced environmental impact within gearbox assembly

Malmgren, My, Lindvall, Nils January 2020 (has links)
Scania är en del av Traton Group och är världsledande inom hållbara transporter. Examensarbetet genomfördes hos transmissionsmontering på Scania i Södertälje där även huvudkontoret för forskning och utveckling ligger beläget. I Södertälje finns produktionsenheter för chassi, motor och transmission. På Scanias transmissionsmontering monteras växellådor och axlar ihop, testas och målas innan de slutligen lämnar området. Projektet har fokuserat på växellådsmonteringen och tillhörande utrustning och processer. Scanias transmissionsmontering står inför flera utmaningar kopplade till framtiden och för att fortsätta sträva mot att vara ledande inom hållbara transporter behöver även nya steg tas mot en mer hållbar produktionsmiljö. Projektet syftar till att undersöka produktionsförhållanden och utrustning hos transmissionsmontering och hur dessa kan effektiviseras med avseende på hållbarhet. Genom att ta fram områden med hög miljöpåverkan och energikonsumering kan också framtagning av lösningsförslag och rekommendationer göras. Vid implementation skulle detta bidra till en minskning av transmissionsmonteringens miljöpåverkan. Arbetet påbörjades med utformning av en teoretisk referensram för arbetet. Den teoretiska referensramen behandlade teori och information relevant till arbetets syfte och undersökningsområden. Den teoretiska referensramen fokuserade på hållbar utveckling, miljöpåverkan samt energi och avfall. Därpå utfördes en nulägesanalys för identifiering av de mest kritiska undersökningsområdena utifrån ett hållbarhetsperspektiv. De kritiska områdena utgjordes av värme- och elförbrukning samt energiåtervinning av icke-farligt avfall. För framtagning av relevanta lösningsförslag kopplade till de kritiska undersökningsområdena utfördes en litteraturstudie. Resultatet från litteraturstudien granskades sedan i en beslutsmatris för att presentera slutgiltiga rekommendationer för de kritiska undersökningsområdena. Beslutsmatrisen som användes för framtagning av de slutgiltiga rekommendationerna utgick ifrån lösningsförslagens påverkan utifrån ekonomisk och ekologisk påverkan. Den ekologiska påverkan uttrycktes i koldioxidekvivalenter medan den ekonomiska påverkan uttrycktes i lösningsförslagens återbetalningstid. Det lösningsförslag som presenterades som rekommendation kopplat till energiförbrukningen var sensibel värmelagring. Det lösningsförslag som blev den slutgiltiga rekommendationen för att minska miljöpåverkan från avfall ur ett hållbarhetsperspektiv blev ett ''rätt från mig''-system. / Scania is a part of the Traton Group and is world leading within sustainable transports. The master thesis was performed at the transmission assembly at Scania in Södertälje, where the headquarters for research and development also is located. In Södertälje, production units for chassi, engine, and transmission are located. At Scania's transmission assembly gearboxes and axles are assembled, tested and painted before leaving the area. The project focused on gearbox assembly and the related equipment and processes. Scania's transmission assembly faces several challenges connected to the future and in order to continue their vision of being the leader within sustainable transports, new steps needs to be taken towards a more sustainable production environment. The project aims to look over the production conditions and equipment of the transmission assembly and how these can be improved regarding sustainability. By finding areas with high environmental impact and energy consumption, solutions can be developed and recommendations can be made. If implemented, this would contribute to a reduction in the environmental impact of the transmission assembly. The project began with a theoretical reference frame. The theoretical reference frame included theory and information regarding the project's purpose and the areas of investigation. The theoretical reference frame focused on sustainable development, environmental impact as well as energy and waste. Thereon, a current state analysis was conducted in order to identify the most critical areas of investigation from a sustainability perspective. The most critical areas of investigation consisted of heat and electricity consumption as well as energy recovery of non-hazardous waste. In order to identify relevant solutions to the critical areas, a literature study was conducted. The results from the literature study was analyzed with respect to ecological and economic sustainability. The solutions were compared via a decision matrix to produce a final recommendation. The decision matrix that was used was based on ecological and economic sustainability. In the matrix, the different solutions were compared with regards to carbon dioxide equivalents from an ecological perspective and with regards to the payback time from an economic perspective. The solution that was presented as the final recommendation from an energy perspective was sensible heat storage. The final recommendation in order to reduce the environmental impact from waste was a ''right from me'' system.
47

Berücksichtigung der Energieeffizienz der Fertigung in Konstruktion und Planung: Energieeffizienzbewertung in der Produktfertigung: Von innen nach außen, vom Kern zur Hülle

Mose, Christian 02 August 2021 (has links)
Produktivitätssteigerung und Effizienzsteigerung sind Ziele, die durch marktwirtschaftlichen Wettbewerb vielfach zum Standardrepertoire der Entwicklung sowie der kontinuierlichen Verbesserung gehören. Trotzdem besteht hinsichtlich der Energieeffizienz in der Produktion noch immer dringender Handlungsbedarf. Auch wenn ein großer Teil aller Umweltauswirkungen eines Produktes in Entwicklung und Konstruktion festgelegt werden und in der Nutzungsphase anfallen, besteht der Handlungsbedarf zunächst in der Produktion. Ohne Transparenz hinsichtlich des verursachten Energiebedarfs zur Herstellung eines Produktes in der Produktion, kann dieser in der Konstruktion nicht berücksichtigt und daher nicht zielgerichtet minimiert werden. Weiterhin werden sehr viele Produkte für die Industrie wiederum in der Produktion eingesetzt und sind damit in ihrer Lebensphase Verursacher des Energiebedarfs in der Herstellungsphase der nächsten Generation von Produkten. Gegenstand dieser Arbeit ist es die Grundlage zur zielgerichteten Erfassung und Dokumentation des Energieeinsatzes in der Produktion am Beispiel von Prozessketten rund um Fügeprozesse zu untersuchen und einen Kennwert zu entwickeln, der in der Produktion erfasst und in der Konstruktion sowie der Arbeitsvorbereitung verwendet werden kann, um den Energiebedarf zunächst zu beurteilen und im Weiteren nachhaltig zu reduzieren. Diese Arbeit liefert das Werkzeug, um Transparenz zu schaffen und damit im Folgenden den produktspezifischen Energiebedarf in der Produktion zu reduzieren. Im Ergebnis wird ein Kennwert entwickelte der zusätzlich geeignet ist als dynamischer Leistungsindikator in der Prozessoptimierung und im Fabrikbetrieb verwendet zu werden.:1 Einleitung 1.1 Zielsetzung 1.2 Abgrenzung des Betrachtungsbereiches 2 Energie im Produktlebenszyklus – Stand der Technik 2.1 Produktlebenszyklus 2.1.1 Lebenszyklusanalyse 2.1.2 Kumulierter Energieaufwand (KEA) 2.1.3 Produktentwicklung und Konstruktion 2.2 Energie- und ressourceneffiziente Produktion 2.3 Prozessketten 2.4 Resümee der Analysen des Stands der Technik 3 Fügeprozesse im Produktlebenszyklus – eine naturwissenschaftliche Betrachtung 3.1 Energie im Schweißprozess 3.2 Schweißtechnologien im Zentrum der Betrachtung 3.2.1 Metallschutzgasschweißen 3.2.2 Laserschweißen 3.2.3 Reibrührschweißen 3.2.4 Hybridisierung von Schweißverfahren 3.3 Fügeprozessketten 3.3.1 Vorbereitung und Nachbereitung 3.3.2 Trennen 3.3.3 Spanende Bearbeitung - Nahtvorbereitung 3.3.4 Richten 3.3.5 Reinigen 3.4 Energieeinsatz in Fügeprozessen 3.5 Energieeffizienz 3.5.1 Physikalische Betrachtung 3.5.2 Thermodynamische Analyse 3.5.3 Primär-Sekundär-Analyse 4 Handlungsbedarf 5 Energieeffizienz in Fügeprozessketten 5.1 Kritische Diskussion des Kennwertes der Streckenenergie 5.2 Definition des Kennwertes des spezifischen Energiebedarfs 5.3 Berechnung von spezifischen Energiebedarfen 5.3.1 Betriebszustände 5.3.2 Systemgrenze 5.3.3 Berücksichtigung von nicht-elektrischen Energieformen in der Bilanzierung 5.3.4 Elektrisches Äquivalent von Energiebedarfen aller Art 5.3.5 Unterscheidung primärer und sekundärer Verbraucher 5.3.6 Unterscheidung dynamischer und statischer Energiebedarfe 5.4 Energiemesssystem 5.5 Bestimmung von Energieprofilen einzelner Fertigungsverfahren 5.5.1 Wirkungsgradketten bei Schweißprozessen 5.5.2 Steckdoseneffizienz 5.5.3 „Verlustarten“ 5.5.4 Übertragung auf verwandte Prozessvarianten 5.6 Energiedaten von Alternativprozessen 5.6.1 Vorgehen bei andersartigen Technologien 5.6.2 Entwicklung einer alternativen Herangehensweise 5.7 Reichweite der Energieprofile auf Ebene einer Fertigungstechnologie 5.8 Wertschöpfung an „Verlustleistungen“ 6 Anwendung 6.1 Betrachtung der Prozesskette 6.2 Berechnung spezifischen Energiebedarfs für das MIG-Schweißen 6.2.1 Unterscheidung primärer und sekundärer Verbraucher 6.3 Berechnung des spezifischen FSW-Energiebedarfs 6.4 Ergebnis 7 Zusammenfassung und Ausblick 7.1 Zusammenfassung 7.2 Ausblick 8 Literatur 8.1 Abbildungsverzeichnis 8.2 Tabellenverzeichnis A Anhang A-1 Typische Betriebszustände A-2 Vergrößerte Abbildungen A-3 Abbildungen „in Anlehnung“
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Förståelsen om FN:s globala hållbarhetsmål : Hur arbetar småföretag med FN:s globala hållbarhetsmål

Ayoubi, Hilal, Maher Ali, Ali January 2021 (has links)
Tidens största utmaning idag är klimatförändringen och dess negativa effekter. En grund till många fall av att politisk instabilitet, hälsorisker och ojämlikheter i mänskliga rättigheter är ohållbara konsumtions- och produktionsmönster som leder till miljöförstöring och sociala orättvisor. Tillväxtverket (2020) utförde en undersökning som har påvisat att närmare hälften av de svenska näringsliv arbetar med ett hållbart arbete. Men å andra sidan är det viktigt att iaktta att arbetet mot hållbar utveckling har utvidgat sig och blivit allt mer komplicerad att uppfylla de senaste decennierna.  Syftet med denna studie har varit att undersöka hur de mindre företagen värdesätter FN:s globala hållbarhetsmål 12.4 i två olika branscher, samt hur de aktivt arbetar med att förbättra det. Syftet har uppfyllts genom att författarna genomfört intervjuer med två mindre fallföretag, det ena är Gästrike Ekogas och det andra är St:Eriks. Författarna har därmed genomfört en litteraturstudie i områden som anses relevanta. Studien identifierade två nyckelfaktorer, den första nyckelfaktorer är att Gästrike Ekogas inte arbetar utifrån den globala målen och har därför inte värderingar. För att förbättra arbetet inom hållbarhet har det även påvisats att verksamheten saknar resurser. Den andra nyckelfaktorer som författarna identifierat, är att St:Eriks vision är att de ska vara det självklara valet för hållbar samhällsbyggnad, vilket visar att de har en seriös värdering för hållbarhet. De tar också miljön som ett nyckelområde och har arbetar hårt med det. Eftersom företaget överväger utsläpp av kemiska ämnen och dess konsekvenser arbetar St:Eriks också ständigt för att minska dessa utsläpp med hjälp av sina interna resurser och tredje part. Det har även påvisats för att verksamheten i fråga skall ha en kapabilitet att kombinera ny teknik, förändringar till praxis, med nya affärsmodeller. För att verksamheter lyckligtvis skall anta och implementera en hållbar konsumtion och produktion handlar det i princip om att kräva förändring i organisationens vision och utbildningar. Med tanke på att St:Eriks produkter har en lång livslängd så var det väldigt viktigt för dem att förhålla sig till FN:s 12e globala mål då den innefattar produktion och konsumtion. / The biggest challenge of the time today is climate change and its negative effects. One reason for many cases of political inequality, health risks and human rights inequalities is consumption and production patterns that lead to environmental degradation and injustice. Statistics from the Swedish Agency for Growth (2020) have shown that almost half of Swedish industry works with sustainable work. On the other hand, however, it is important to observe that the work towards sustainable development has expanded and become increasingly complicated to meet the latest conditions.  The purpose of this study is to investigate how highly the smaller companies value the UN's Global Sustainability Goals 12.4 in two different industries, and how they actively work to improve that work. The purpose has been fulfilled by the authors conducting interviews with two case companies, thus the authors have conducted a literature study in areas considered relevant. The study identified two key factors, the first key factor being that Gästrike Ekogas does not work on the basis of the global goals and therefore does not have values. In order to improve the work in sustainability, it has also been demonstrated that the business lacks resources. The other key factor identified by the authors is that St:Erik's vision is that they should be the obvious choice in sustainable community building, which indicates a lot that they have a serious value about sustainability. They also have the environment as a focus area, and which they work with constantly. As the business takes into account the chemical emissions and its consequences, and that St:Eriks also works constantly to reduce these emissions with the help of resources that exist within the business and with the help of third parties.  It has also been demonstrated that the activities in question should have the capability to combine new technologies, changes to practices, with new business models. In order for businesses to fortunately adopt and implement sustainable consumption and production, it is basically about demanding change in the organization's vision and education. Since St:Erik's products have a long lifespan, it was very important for them to relate to the UN's 12th global goals as it includes production and consumption.
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Desenvolvimento de dispositivos fotoeletroqu?micos ? base de BiVO4/Bi4V2O11 para convers?o de energia solar em energia el?trica ou energia qu?mica a partir de res?duos l?quidos industriais

Santos, Wayler Silva dos 18 May 2017 (has links)
?rea de concentra??o: Produtos e coprodutos. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-10-03T14:42:21Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wayler_silva_santos.pdf: 9149649 bytes, checksum: 7d300a18f29fb2d1bfa9a3ab5c806ad3 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-10-09T14:02:32Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wayler_silva_santos.pdf: 9149649 bytes, checksum: 7d300a18f29fb2d1bfa9a3ab5c806ad3 (MD5) / Made available in DSpace on 2017-10-09T14:02:32Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wayler_silva_santos.pdf: 9149649 bytes, checksum: 7d300a18f29fb2d1bfa9a3ab5c806ad3 (MD5) Previous issue date: 2017 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / A convers?o da energia da radia??o solar em H2(g), combust?vel verde, usando-se c?lulas fotoeletroqu?micas (PEC) ? uma estrat?gia atraente para armazenar energia e minimizar o uso extensivo de combust?veis f?sseis. Neste trabalho, foram fabricados fotoeletrodos por deposi??o spray pyrolysis de um comp?sito de BiVO4/Bi4V2O11 puro ou dopado com W, depositado diretamente sobre um substrato condutor FTO (sigla para fluorine-doped tin oxide) ou sobre uma camada de SnO2 previamente depositada sobre o substrato FTO. Inicialmente, os materiais foram testados na clivagem molecular da ?gua. Verificou?se a forma??o de uma camada de invers?o de buracos induzida pela perovskita ferroel?trica Bi4V2O11 na interface com BiVO4 de tipo?n criando uma jun??o p?n virtual. A fotovoltagem de sa?da elevada da jun??o, em rela??o a uma heterojun??o p?n convencional, que pode ser ainda aumentada alterando-se a polariza??o e dopando-se o material ferroel?trico com tungst?nio, acarreta diminui??o da recombina??o dos pares el?tron?buracos fotogerados na superf?cie e aumenta a fotocorrente em at? 180%. O comportamento de semicondutores de tipo?p e n quando iluminados sugere o uso potencial da heterojun??o como fotoanodo e fotocatodo em uma c?lula PEC (ou photoelectrochemical cell) com dois fotoeletrodos. Este conceito foi comprovado pela conex?o do fotoanodo BiVO4/Bi4V2O11 dopado com 1% em massa de tungst?nio com o fotocatodo BiVO4/Bi4V2O11 n?o dopado. O sistema formado pelo acoplamento fotoanodo-fotocatodo produziu uma fotovoltagem de 1,54 V, e 0,36% de efici?ncia STH (solar-to-hydrogen efficiency). Um fotoeletrodo BiVO4/Bi4V2O11 dopado com 2% em massa de W foi otimizado. Evidenciou-se a forma??o da camada de invers?o de buracos na interface semicondutora no filme mais denso. Este ?ltimo foi testado em diferentes solu??es, obtendo-se elevadas densidades de corrente em NaAc 0,5 mol L-1, ? medida que se adicionou glicerina e vinha?a. Obteve?se a menor resist?ncia na transfer?ncia de cargas na interface eletrodo/eletr?lito 1,16 k? sob ilumina??o, utilizando a solu??o NaAc 0,5 mol L-1 contendo 20 %v/v de vinha?a. Nessas condi??es, a efici?ncia da convers?o de energia foi aumentada em aproximadamente 100%, e dependendo do potencial aplicado a efici?ncia aumentou cerca de 30% em solu??o contendo 10 %v/v de glicerina, com rela??o ? solu??o NaAc 0,5 mol L-1 pura, demonstrando que glicerina e vinha?a atuam como agentes de sacrif?cio eficazes no sequestro de buracos eletr?nicos, para evitar a recombina??o dos pares de el?tron?buraco, no processo de foto?oxida??o acionado por buracos. / Tese (Doutorado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The conversion of solar energy into green fuel H2(g) using photoelectrochemical cells (PEC) is an attractive strategy for storing energy and minimizing the extensive use of fossil fuels. In this work, photoelectrodes were prepared by pyrolysis spray deposition from a pure or W?doped BiVO4/Bi4V2O11 composite deposited directly onto an FTO (fluorine-doped tin oxide) electron-conductive substrate or onto a SnO2 layer previously deposited on an FTO substrate. Initially, these materials were tested for molecular water cleavage. It was observed a hole inversion layer induced by the ferroelectric perovskite Bi4V2O11 at the interface of the n?type BiVO4; a virtual p?n junction with high output photovoltage in relation to a conventional p?n heterojunction was also created. Altering the polarization and doping the ferroelectric material with tungsten may increase the p-n heterojunction. This polarization also reduces the recombination of the photogenerated electron?hole pairs on the surface, to increase the photocurrent to as much as 180%. This characteristic behavior of the p?type and n?type semiconductors when illuminated suggests the use of such a heterojunction as photoanode and photocatode in a PEC cell with two coupled photoelectrodes. This concept was proved to effectively work, by connecting the photovoltaic BiVO4/Bi4V2O11 doped with 1 mass% of W to the non?doped BiVO4/Bi4V2O11 photocathode, which produced a high photovoltage of 1.54 V, and 0.36% STH (solar-to-hydrogen) efficiency. A BiVO4/Bi4V2O11 photoelectrode doped with 2 mass% tungsten was optimized, evidencing the inversion of the hole layer at the semiconductor interface in the resulting denser film. This film tested in different liquid solutions revealed to produce high current densities in 0.5 mol L-1 sodium acetate (NaAc), if glycerol and vinasse were added. The electric resistance in the charge transfer at the electrode/electrolyte interface was relatively low, or 1.16 k? under illumination using 0.5 mol L-1 NaAc solution containing 20 %v/v vinasse. Adding vinasse meant an increase of the energy conversion efficiency corresponding to approximately 100%, and depending on the applied potential efficiency increased by about 30% in solution containing 10% v/v glycerin, relatively to the pure 0.5 mol L-1 NaAc solution. These results evidence that glycerin and vinasse act as effective sacrificing agents, to sequester holes and avoid the recombination of electron?hole pairs in the photo?oxidation driven by holes.
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Sustainable beef production in Brazil: different interests to a common cause

Bedier, Josephine Marie Laurence Camille 04 September 2017 (has links)
Submitted by Bédier Joséphine (josephine.bedier@hec.edu) on 2017-10-02T20:26:10Z No. of bitstreams: 1 Master thesis Joséphine Bédier .pdf: 2100124 bytes, checksum: 79b1f0c99f4d74244a89379fc588f293 (MD5) / Approved for entry into archive by Josineide da Silva Santos Locatelli (josineide.locatelli@fgv.br) on 2017-10-03T17:25:27Z (GMT) No. of bitstreams: 1 Master thesis Joséphine Bédier .pdf: 2100124 bytes, checksum: 79b1f0c99f4d74244a89379fc588f293 (MD5) / Made available in DSpace on 2017-10-04T12:20:08Z (GMT). No. of bitstreams: 1 Master thesis Joséphine Bédier .pdf: 2100124 bytes, checksum: 79b1f0c99f4d74244a89379fc588f293 (MD5) Previous issue date: 2017-09-04 / With the increasing concerns of beef production being the first cause of Amazonian deforestation, the Brazilian beef industry has taken major steps in recent years towards a more sustainable production. In this very competitive market, producers, industrials and retailers are each acting at their own level for this common cause. The aim of this qualitative research is to find out how the interests of these stakeholders can be aligned. The literature review covers a brief history of sustainable beef in the country, main concepts associated and the role and perception of each of the stakeholders of the beef value chain. Selected case studies and interviews of the actors of a given supply chain highlighted that it is urgent to accord on common objectives and on a practical action plan to unify monitoring systems. If there is no price premium for sustainable beef products, production becomes more efficient and this translates into profitability gains after the initial investment is repaid. Moreover, this effort should include small players who need financial support and technical assistance to integrate new technologies in their business to be able to control their social and environmental impact. / Com a crescente preocupação de que a produção de carne bovina é a primeira causa do desmatamento amazônico, a indústria brasileira produtora de carne bovina deu passos importantes nos últimos anos para uma produção mais sustentável. Neste mercado muito competitivo, os produtores, as indústrias e os varejistas estão agindo por essa causa comum. O objetivo desta pesquisa qualitativa é descobrir como os interesses dessas partes interessadas podem ser alinhados. A revisão da literatura abrange um breve histórico da produção de carne bovina de modo sustentável no país e também os principais conceitos associados e o papel e a percepção de cada uma das partes interessadas na cadeia de valor da carne bovina. Estudos de caso selecionados e as entrevistas dos atores de uma determinada cadeia de suprimentos destacaram que é urgente chegar a objetivos comuns e a um plano de ação prático para unificar os sistemas de monitoramento. Se houver preço diferenciado para a carne produzida de modo sustentável, a produção se torna mais eficiente e isso se traduz em ganhos e rentabilidade após o reembolso do investimento inicial. Além disso, este esforço deve incluir investimentos financeiros para apoiar e dar assistência técnica para integrar novas tecnologias a seus negócios para poder controlar seu impacto social e ambiental.

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