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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.
171

Caracterizações das frações do resíduo do triturador de sucata de uma siderúrgica

Câmara, Gabriela Grespan January 2017 (has links)
O setor siderúrgico é um grande consumidor de energia e envolve grandes volumes de insumos, emissões de poluentes e resíduos sólidos. As usinas siderúrgicas semi-integradas são recicladoras de aço, tendo a sucata como sua principal matéria-prima. Os trituradores de sucata são utilizados para minimizar as impurezas e ajustar as dimensões da sucata. Esta etapa de separação gera um grande volume de resíduos que não são aproveitados no processo siderúrgico. Assim, o objetivo deste trabalho foi caracterizar as frações do resíduo de um triturador de sucata de uma indústria siderúrgica da região do Vale dos Sinos-RS, para fins de um posterior reaproveitamento. Através de estudos de otimização do equipamento foi possível separar o material em quatro frações <20 mm (funil), >20 e <30 mm (EC1), >30 e <100 mm (EC2) e >100 mm (TC9). Estas frações foram analisadas em relação à composição das amostras, distribuição granulométrica, análise térmica, análise imediata, análise elementar, análise do poder calorífico superior, microscopia eletrônica de varredura (MEV) e a concentração de metais. Pode se concluir que a fração fina (<20 mm), possui potencial para incorporação em blocos cerâmicos estruturais. A fração entre 20 mm e 30 mm apresentam características compatíveis para o uso na indústria cimenteira. As amostras de maior granulometria, fração entre 30 e 100 mm e > 100 mm, apresentam potencial de uso para o reaproveitamento energético. Apontou-se oportunidade na recuperação de ferrosos e não ferrosos em todas as frações estudadas. Para o reaproveitamento do resíduo do shredder é necessário a separação deste em granulometrias diferentes. / The steel sector is a major consumer of energy and involves large volumes of inputs, pollutant emissions and solid waste. The semi-integrated steel mills are steel recyclers, with scrap as their main raw material. Scrap grinders are used to minimize impurities and adjust scrap dimensions. This separation stage generates a large volume of waste that is not used in the steelmaking process. Therefore, the objective of this work was to characterize the fractions of the waste from a scrap crusher from a steel industry in the Vale dos Sinos-RS region, for purposes of subsequent reuse. By means of equipment optimization studies it was possible to separate the material into four fractions <20 mm (funnel),> 20 and <30 mm (EC1),> 30 and <100 mm (EC2) and> 100 mm (TC9). These fractions were analyzed in relation to the composition of the samples, particle size distribution, thermal analysis, immediate analysis, elemental analysis, higher calorific value analysis, scanning electron microscopy (SEM) and metal concentration. It can be concluded that the fine fraction (<20 mm) has potential for incorporation of the raw material for the production of structural ceramic blocks. The smaller fractions (<20 mm and <30 mm) have compatible characteristics for use in the cement industry. Samples with higher grain size (> 30 mm and> 100 mm) show potential for use in energy recovery. It was pointed out an opportunity in the recovery of ferrous and non-ferrous in all fractions studied. For the reuse of the shredder residue it is necessary to separate it in different granulometry.
172

Impactos de medidas antidumping adotadas pelos EUA sobre o setor siderúrgico e suas consequências para a economia de Minas Gerais e o restante do Brasil

Firme, Vinícius de Azevedo Couto 18 February 2009 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-03T19:54:33Z No. of bitstreams: 1 viniciusdeazevedocoutofirme.pdf: 1460667 bytes, checksum: 67997771a02f81530da5999caf147cec (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-04T11:49:07Z (GMT) No. of bitstreams: 1 viniciusdeazevedocoutofirme.pdf: 1460667 bytes, checksum: 67997771a02f81530da5999caf147cec (MD5) / Made available in DSpace on 2017-04-04T11:49:07Z (GMT). No. of bitstreams: 1 viniciusdeazevedocoutofirme.pdf: 1460667 bytes, checksum: 67997771a02f81530da5999caf147cec (MD5) Previous issue date: 2009-02-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho objetivou analisar o impacto da medida antidumping, iniciada em outubro de 1998, contra as exportações do setor siderúrgico provenientes do Brasil que tinham como destino os EUA. Especificamente, objetivou-se verificar os efeitos decorrentes desta barreira comercial sobre a produção e emprego dos setores do Estado de Minas Gerais e do restante do Brasil. Para tanto, inicialmente estimou-se uma função de exportação a fim de capturar os possíveis impactos restritivos da medida antidumping às exportações produtos de aço laminados a quente, compreendidas no período entre janeiro de 1995 a dezembro de 2002, provenientes de Minas Gerais. Posteriormente, o resultado deste modelo foi incorporado ao vetor de exportações do setor siderúrgico de Minas Gerais e inserido em matrizes de insumo-produto inter-regionais, para os anos de 1999 a 2002. As matrizes utilizadas continham as relações comerciais entre 13 setores de Minas Gerais e outros 13 do restante do Brasil e destas duas regiões com o exterior. Logo, esta análise possibilitou a mensuração dos impactos de tal medida sobre os diversos setores da economia de Minas Gerais e do restante do Brasil. Como resultado, pode-se concluir que a medida antidumping afetou de maneira significativa as exportações da siderurgia de Minas Gerais, sendo que seu impacto mais contundente ocorreu logo após a implementação de um direito antidumping provisório. Observou-se uma redução média de 11.48 % ao ano das exportações mineiras no período de tempo analisado. No entanto, o impacto na produção e emprego dos setores de Minas Gerais e do restante do Brasil foi relativamente pequeno, devido à baixa representatividade dos produtos de aço laminados a quente, no total exportado pela siderurgia de Minas Gerais. Entretanto, o estudo gerou indícios de que as exportações da siderurgia de Minas Gerais afetam com maior intensidade setores como: a própria siderurgia, de Minas Gerais e do restante do Brasil, no que diz respeito à produção. Com relação ao emprego os setores nas duas regiões que seriam mais impactados são a agropecuária; comércio e serviços e transporte. / This work pointed to analyse the impact of the antidumping measure, started in October of 1998, against the exportation of the Iron and Steel sector from Brazil towards the United States. Specifically, pointed itself to verify the effects that came from this commercial barrier on the production and employment of the sectors of Minas Gerais state and the rest of Brazil. For that, at the beginning, an exportation function was estimated trying to captive the possible restrictive impacts of the antidumping measure to exportation of Laminated Steel by heat, within the period between January of 1995 and december o 2002, from Minas Gerais State. Subsequantially, the result of the model was incorporated to the vector of Iron and Steel Industry exportation from Minas Gerais, and inserted into matrixes of inter-regional input-output, for the years between 199 and 2002. The Matrixes used, had commercial relationships with 13 sectors of Minas Gerais and other 13 sectors throughout Brazil and from these two regions with abroad. Therefore, this analysis, made possible the mensuration of the impacts of such measure on the various sectors of Minas Gerais' economy and the rest of Brazil's. As a result, it can be concluded that the antidumping measure affected the exportation of the Iron and Steel Industry of Minas Gerais, in a significant way, having its most cutting impact occurring right after the implementation of a provisory antidumping right. It was noticed an average reduction of 11.48% a year of the Minas Gerais' exportation on the period analysed. Yet, the impact on the production and employment of Minas Gerais' and the rest of Brazil was relatively small, due to the low representativity of the Laminated Steel by heat products on the total exported by the Iron and Steel Industry in Minas Gerais. In the meaning time, the study came up with clues that the Minas Gerais' Iron and Steel Industry exportation affect with more intensity sectors such as: the Iron and Steel Industry itself, not only from Minas Gerais but from the entire country, when it comes to production. About the employment, on both areas the most impacted sectors would be the farming (stockbreeding), Commerce, services and transportation.
173

Détermination du rôle de l'énergie dans la compétitivité de l'industrie manufacturière : Études économétriques et modélisation des interdépendances / Role of Energy in the Manufacturing Industry Competitiveness : Econometric studies and Interdependencies modelling

Bordigoni, Mathieu 11 October 2012 (has links)
La crainte d'une perte de compétitivité industrielle est au cœur des débats sur de nouvelles politiques énergétiques et environnementales. Cette thèse étudie les effets d'une asymétrie des prix de l'énergie et des régulations environnementales entre pays sur la compétitivité de l'industrie manufacturière en Europe et dans le Monde. Dans un premier temps, les principaux déterminants de la compétitivité de deux industries grandes consommatrices d'énergie, la sidérurgie et l'industrie du papier, sont identifiés par des méthodes économétriques. Le rôle de l'énergie est ensuite quantifié et pondéré par rapport à ces déterminants. Notamment, l'évolution des exportations et de la production d'une industrie nationale ainsi que les changements de capacité des sites de production sont analysés. Dans un second temps, une hausse des prix de l'énergie, ou l'instauration d'une contrainte environnementale, n'affecte pas uniquement les secteurs grands consommateurs d'énergie mais aussi les industries en aval de la chaîne de production industrielle. L'échelle de l'étude est alors étendue à toute l'industrie manufacturière sur un périmètre mondial. L'objectif est d'appréhender les interdépendances énergétiques des secteurs industriels, en incluant les différences nationales et sectorielles, au travers d'une étude matricielle sur les tableaux entrées-sorties. La dépendance de l'industrie aux prix de l'énergie, et donc sa compétitivité, n'est pas seulement un enjeu national, mais une problématique européenne, voire mondiale. / A loss of industrial competitiveness is a major concern for energy and environmental policy design. This thesis studies the impacts of energy prices and environmental regulation asymmetries among countries on the competitiveness of the manufacturing industry in Europe and in the World. First, main factors of competitiveness in two energy-intensive industries, steel and paper sectors, are identified with econometric methods. The role of energy is then quantified and weighted relatively to these other factors. In particular, the evolution of exports and production for a national industry, as well as changes in production capacities of a factory, are analysed. Secondly, high energy prices, or a new environmental regulation, do not impact only energy-intensive industries but also downstream manufacturing sectors. The scale of the research is therefore extended to the whole manufacturing industry on a global scope. The objective is to grasp energy interdependencies between industrial sectors all along the production chain, including national differences in energy use. The study is based on a matrix calculation method using Input-Output tables. Energy dependence of national industries is not only a domestic issue, but also an international one.
174

Die strukturele gebruik van warmgewalsde tipe 3CR12 vlekvrye staal

Bosch, Hans Hendrik 05 June 2014 (has links)
M.Ing. (Civil Engineering) / The purpose of this investigation was to develop the basic information necessary for formulating creteria for the design of Type 3CR12 steel hot-rolled sections as columns. The mechanical properties needed for structural design are established. Investigations into the behaviour of axially loaded compression members indicated that the overall column buckling of compression members may be predicted with confidence by the tangent modulus approach. Finally simplified design recommendations are made for the design of Type 3CR12 steel hot-rolled columns. The need for future research are identified.
175

Caracterizações das frações do resíduo do triturador de sucata de uma siderúrgica

Câmara, Gabriela Grespan January 2017 (has links)
O setor siderúrgico é um grande consumidor de energia e envolve grandes volumes de insumos, emissões de poluentes e resíduos sólidos. As usinas siderúrgicas semi-integradas são recicladoras de aço, tendo a sucata como sua principal matéria-prima. Os trituradores de sucata são utilizados para minimizar as impurezas e ajustar as dimensões da sucata. Esta etapa de separação gera um grande volume de resíduos que não são aproveitados no processo siderúrgico. Assim, o objetivo deste trabalho foi caracterizar as frações do resíduo de um triturador de sucata de uma indústria siderúrgica da região do Vale dos Sinos-RS, para fins de um posterior reaproveitamento. Através de estudos de otimização do equipamento foi possível separar o material em quatro frações <20 mm (funil), >20 e <30 mm (EC1), >30 e <100 mm (EC2) e >100 mm (TC9). Estas frações foram analisadas em relação à composição das amostras, distribuição granulométrica, análise térmica, análise imediata, análise elementar, análise do poder calorífico superior, microscopia eletrônica de varredura (MEV) e a concentração de metais. Pode se concluir que a fração fina (<20 mm), possui potencial para incorporação em blocos cerâmicos estruturais. A fração entre 20 mm e 30 mm apresentam características compatíveis para o uso na indústria cimenteira. As amostras de maior granulometria, fração entre 30 e 100 mm e > 100 mm, apresentam potencial de uso para o reaproveitamento energético. Apontou-se oportunidade na recuperação de ferrosos e não ferrosos em todas as frações estudadas. Para o reaproveitamento do resíduo do shredder é necessário a separação deste em granulometrias diferentes. / The steel sector is a major consumer of energy and involves large volumes of inputs, pollutant emissions and solid waste. The semi-integrated steel mills are steel recyclers, with scrap as their main raw material. Scrap grinders are used to minimize impurities and adjust scrap dimensions. This separation stage generates a large volume of waste that is not used in the steelmaking process. Therefore, the objective of this work was to characterize the fractions of the waste from a scrap crusher from a steel industry in the Vale dos Sinos-RS region, for purposes of subsequent reuse. By means of equipment optimization studies it was possible to separate the material into four fractions <20 mm (funnel),> 20 and <30 mm (EC1),> 30 and <100 mm (EC2) and> 100 mm (TC9). These fractions were analyzed in relation to the composition of the samples, particle size distribution, thermal analysis, immediate analysis, elemental analysis, higher calorific value analysis, scanning electron microscopy (SEM) and metal concentration. It can be concluded that the fine fraction (<20 mm) has potential for incorporation of the raw material for the production of structural ceramic blocks. The smaller fractions (<20 mm and <30 mm) have compatible characteristics for use in the cement industry. Samples with higher grain size (> 30 mm and> 100 mm) show potential for use in energy recovery. It was pointed out an opportunity in the recovery of ferrous and non-ferrous in all fractions studied. For the reuse of the shredder residue it is necessary to separate it in different granulometry.
176

Tools for Evaluating Energy Efficiency of Steel Production : Lessons from Sweden and Europe

Morfeldt, Johannes January 2014 (has links)
The European Union faces challenges related to climate change, security of energy supply, and competitiveness of European industries. Energy efficiency indicators are required for monitoring and controlling the effectiveness of policies such as the recently endorsed Energy Efficiency Directive. This thesis aims at assessing whether traditionally used energy efficiency indicators capture the development of energy efficiency in the iron and steel sector. The study is based on results from two statistical methods: a top-down, i.e. Malmquist productivity index, and a bottom-up, i.e. partial least squares regression. The specific energy consumption (the indicator representing the sector within the Odyssee energy efficiency index) was scrutinised together with associated indicators based on economic production using the aforementioned statistical methods. The results demonstrated the specific energy consumption does not capture the characteristics of the value chain of steel products. Therefore, it is not sufficient for capturing the energy efficiency of iron and steel industries. Previous studies suggest using indicators based on economic production (e.g. value added) since they represent the value chain to larger degree. However, the value creation process of companies belonging to larger international groups cannot be estimated reliably. Furthermore, the trends of both types of indicators tend to be highly influenced by structural changes, veiling the actual efficiency development. Energy use statistics published by international organisations were also compared for the Swedish case. The results demonstrated that international organisations use different methodologies for allocating energy use statistics between consumption and transformation sectors. The method has significant implications on the trends observed, if based on openly available statistics. This thesis complements previous research by reviewing implications of traditional energy efficiency indicators based on company data, national statistics or openly available statistics and contributes with insights essential for future efforts towards improving energy efficiency indicators for the steel industry. / Den europeiska unionen står inför utmaningar relaterade till minskad klimatpåverkan, säkerställd energitillgång samt konkurrenskraften hos europeisk industri. Energieffektiviseringsindikatorer krävs för att övervaka och kontrollera effektiviteten hos energipolicy såsom det nyligen antagna energieffektiviseringsdirektivet. Den här avhandlingen syftar till att bedöma om traditionellt använda energieffektiviserings-indikatorer fångar järn- och stålsektorns utveckling inom energi-effektivitet. Studien är baserad på resultat från två statistiska metoder: en top-down-metod, Malmquists produktivitetsindex, och en bottom-up-metod, partiella minsta kvadratmetoden. Den specifika energikonsumtionen – indikatorn som representerar sektorn i Odyssees energieffektiviseringsindex – granskades tillsammans med andra energieffektivitetsindikatorer med hjälp av de ovan nämnda statistiska metoderna. Resultaten visade att specifik energikonsumtion inte fångar karaktären av stålprodukternas värdekedjor. Indikatorn är därför inte tillräcklig för att fånga energieffektivitet inom järn- och stål-industrier. Tidigare studier föreslår att använda indikatorer baserade på ekonomisk produktion (exempelvis förädlingsvärdet) då de representerar värdekedjan till högre grad. Förädlingsvärdet kan dock inte uppskattas tillförlitligt för företag som tillhör större internationella grupper. Trend-erna hos båda typerna av indikatorer tenderar dessutom att påverkas av strukturella förändringar, vilka döljer den riktiga effektivitetsutvecklingen. En jämförelse gjordes även av energianvändningsstatistik publicerad av olika internationella organisationer för det svenska fallet. Resultaten demonstrerade att internationella organisationer använder olika metoder för att allokera energianvändning mellan konsumtions- och omvandlings-sektorer i statistiken. Metoden påverkar observerade trender signifikant om de baseras på öppet tillgänglig statistik. Avhandlingen kompletterar tidigare forskning genom att belysa innebörden av traditionella energieffektiviseringsindikatorer baserade på företagsdata, nationell statistik eller öppet tillgänglig statistik samt bidrar med insikter som kommer att vara väsentliga för framtida satsningar i att förbättra energieffektiviseringsindikatorer för stålindustrin.
177

Järn- och stålindustrins marknadsföring på sociala medier : En kvalitativ studie om digital marknadsföring för B2B-företag inom järn- och stålindustrin

Högblad, Alexandra January 2021 (has links)
Syfte: Studien syftar till att öka förståelsen för relevansen av digital marknadsföring på sociala medier för B2B-företag inom järn- och stålindustrin och öka kunskapen om betydelsen av hållbarhet i marknadsföringssyfte på sociala medier för dessa företag. Metod: Studien har utgått från en kvalitativ forskningsansats där empiriinsamlingen består av data insamlat från 11 semistrukturella intervjuer. En kvalitativ riktad innehållsanalys togs i anspråk för att vidareutveckla och bekräfta redan befintliga teorier funna inom den teoretiska referensramen. Medan en hermeneutisk ansats användes för att analysera obekräftade teorier och befintliga teoretiska gap funna inom den teoretiska referensramen. Resultat och slutsats: Resultatet av studien indikerar att marknadsföringsrelevansen på sociala medier skiljer sig mellan börsnoterade och icke-börsnoterade företag, mellan olika positioner i företaget och företagets närhet till slutprodukt. Relevansen av marknadsföring på sociala medier skilde sig inte i rekryteringssyfte ur HR- chefens perspektiv, oavsett om företaget var börsnoterat eller icke-börsnoterat. Hållbarhet har en stor betydelse i marknadsföringssyfte på sociala medier och ger företagen konkurrensfördelar. Studiens bidrag: Chefer i olika järn- och stålindustriföretag och andra tunga tillverkningsindustrier kan ta hänsyn till studiens resultat för att öka sin förståelse för relevansen av digitalmarknadsföring på sociala medier samt betydelsen av hållbarhet i marknadsföringssyfte på sociala medier. Detta för att utveckla sin kommande eller befintliga digitala marknadsföring på sociala medier. Förslag till vidare forskning: Vidare forskning föreslås inkludera fler antal intervjurespondenter och företag i studien för att undersöka resultatet i större utsträckning. / Aim: The study aims to increase the understanding of the relevance of digital marketing on social media for B2B- companies in the iron- and steel industry and increase the knowledge of the importance of sustainability in the marketing purpose on social media for these companies. Method: The study used a qualitative research approach, where the collection of empirical data consisted of data collected from 11 semi-structural interviews. A qualitative targeted content analysis method was used to further develop and confirm existing theories found within the theoretical frame of reference. While a hermeneutic approach method was used to analyse unconfirmed theories and existing theoretical gaps found within the theoretical frame of reference. Result and conclusions: The result of the study indicates that the relevance of marketing on social media differs between listed and non-listed companies, between different positions in the company, and by the company's proximity to the end product. The relevance of marketing on social media did not differ in recruitment purposes from the HR manager's perspective, whether the company was listed or non-listed. Sustainability is of great importance for marketing purposes on social media and gives companies a competitive advantage. Contributions: Managers in various iron and steel industry companies and other heavy manufacturing industries can take the findings into account to increase their understanding of the relevance of digital marketing on social media and the importance of sustainability in the marketing purpose on social media for B2B-companies. For developing their upcoming or existing digital marketing on social media. Suggestion for further research: Further research is recommended to include more interview respondents and companies in the survey to examine the results to a greater extent.
178

Critical evaluation of seismic design criteria for steel buildings

Lefki, Lkhider January 1987 (has links)
No description available.
179

Performance of snug tight bolts in moment end-plate connections

Kline, Donald Paul 09 May 2009 (has links)
An experimental investigation was conducted to study the behavior of snug tight ASTM A325 bolts in moment end-plate connections for use in single story buildings. Wind loading was deemed to be the critical loading on snug tight bolt, moment end-plate connections. A test loading sequence was established based on a statistical analysis of the 50-year wind loading on low rise buildings. Eleven specimens, representing six end-plate configurations, were tested under cyclic loading covering expected wind loads in the range of 33 to 100 percent of the connection design (allowable stress design) moment. Following the cyclic loading, the specimens were statically loaded to failure, and the experimental strengths were compared with predicted strengths for connections with fully tightened A325 bolts. Additionally, the effect of snug tight bolts on connection stiffness are considered. Finally, recommendations for the use of snug tight bolts in moment end-plate connections were provided. / Master of Science
180

Experimental research on the behavior and strength of large-scale steel gusset plates with sway-buckling response including effects of corrosion and retrofit options

Hafner, Anthony G. 20 March 2012 (has links)
The collapse of the I-35W Bridge in Minneapolis, MN on August 1, 2007 brought into question the design and inspection of gusset plates in steel truss bridges. The experimental tests performed in this research study the sway-buckling strength and behavior of large-scale steel gusset plates in an isolated truss connection. Parameters studied include plate thickness,combination member loading, initial out-of-plane imperfection, diagonal compression member out-of-plane flexural stiffness, corrosion, and alternative retrofits to increase lateral stiffness. The flexural stiffness of the diagonal compression member and retrofit designs were unique to the testing program. The variables monitored during testing include gusset plate surface stresses and strains, member axial strains, out-of-plane displacement of the gusset plate free edge, and buckling capacity. The results were compared with previously established design models for predicting buckling capacity of gusset plates which include the Whitmore effective width, the Modified-Thornton method, and the FHWA Load Rating Guidelines. A parametric finite element model was developed to determine the lateral stiffness of the gusset plate connection and the additional stiffness provided by the alternative retrofit options. The results showed interaction between the diagonal compression member and gusset plate occurs, which affects sway-buckling capacity. Combination of member loads showed evidence of detrimental effects on sway-buckling capacity. Corrosion of the gusset plates along the top edge of the bottom chord did not lead to significant reduction in sway-buckling capacity. The two retrofit designs showed increases in both lateral stiffness and buckling capacity as well as economic benefits over traditional retrofit methods. Comparison of the results to the current design guidelines showed that the current methods are conservative and do not accurately represent the true behavior of gusset plate connections. The research concludes with two proposed models for future use in design and retrofit of gusset plates. The first is a member-gusset plate interaction model based on a stepped column analogy that takes into account the effects of member flexural stiffness and gusset plate stiffness. The second is a general design guideline developed for retrofit of gusset plate connections dominated by sway-buckling behavior which uses a stiffness based approach to increase the capacity of gusset plate connections. / Graduation date: 2012

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