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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

Advanced supply chain planning processes and decision support systems for large-scale petrochemical companies

Louw, Johannes Jacobus 12 1900 (has links)
Thesis (PhD (Logistics))--University of Stellenbosch, 2006. / Conventional supply chain integration concepts focus primarily on the internal and external integration of individual supply chains (can be viewed as intra-supply chain integration). Due to the highly integrated nature of petrochemical value chains, related supply chains should also be integrated by taking account of enterprise/industry-wide synergies and interdependencies (can be viewed as inter-supply chain integration). Inter-supply chain integration can typically develop along three dimensions: - Upstream feed clusters (upstream in the chemical value chain) - Downstream product clusters (downstream in the chemical value chain) - Macro logistics network clusters (within and across related logistics networks for liquid bulk, dry bulk, packaged goods and gases) This dissertation presents a generic framework of applicable intra- and inter-supply chain planning processes that supports related long- (strategic), medium- (tactical) and short-term (operational) supply chain decisions for large-scale petrochemical companies. This type of companies has to manage relative complex supply chains. Highly complex supply chains (due to an extensive product portfolio, supplier base, customer base, manufacturing processes, transportation, and management processes and systems) require far more advanced planning processes than simple supply chains. Advanced supply chain planning processes cover an extended supply chain scope, deal with longer time horizons, and utilize more sophisticated analytical techniques and decision support systems. An extensive literature study, supplemented by empirical research in the South African petrochemical industry, provided the foundation for the advanced supply chain planning framework concluded in this dissertation. Semi-structured interviews and a questionnaire presented to an informed audience constitute the empirical research conducted. The related best practices, concepts, approaches followed, and level of advancement in three supply chain planning dimensions were derived. To guide petrochemical companies along the planning advancement journey, the roadmap developed can be utilized for the application and implementation of the advanced supply chain planning framework. This roadmap articulates the advancement stages, dimensions, characteristics, and triggers to advance. Typical characteristics associated with the advancement stages and dimensions provide the means for a company to assess their level of progression. The essential mechanisms that can enable interventions are also articulated.
42

Contabilidade ambiental : evidencia????o de eventos econ??micos de natureza ambiental pelas empresas do setor qu??mico e petroqu??mico

Oliveira, Robson de 29 August 2005 (has links)
Made available in DSpace on 2015-12-04T11:45:34Z (GMT). No. of bitstreams: 1 Robson_de_Oliveira.pdf: 643288 bytes, checksum: 18329e7e7b1f697d21ecb335826fcf40 (MD5) Previous issue date: 2005-08-29 / The companies, as integrant part of the society, are being forced to meet environmental goals, besides the economical ones, demonstrating that besides the economical return generated to the shareholders, they are also creating social return to the communities where they are located. Environmental Accounting is the system of information which main aim is to gather, measure and disclose the environmental transactions seeking to exercise the important role of communication vehicle between company and society. In this context, the accounting statements deserve attention and special study, regarding that they represent the main disclosure channel of economic-environmental items of which the Accounting uses. The objective of this work was to analyze a sample of accounting statements published in Brazil with the objective of verifying how the investments, liabilities and environmental costs have been disclosed. Unhappily, the accounting statements of this companies had revealed little adequate to the new necessities of the users of the accounting information, and parallel, insufficient to take care of to the requirements of NBC T 15 - Information of Social and Ambient Nature, approved for the Resolution of the Federal Advice of Accounting - CFC n?? 1.003, that it will enter in vigor from 1?? of January of 2006. / As empresas, como parte integrante da sociedade, est??o sendo fortemente demandadas a cumprirem metas ambientais, al??m das econ??micas; demonstrando que, al??m do retorno econ??mico gerado aos acionistas, tamb??m est??o gerando retorno social ??s comunidades em que se encontram inseridas. A Contabilidade Ambiental apresenta-se como o sistema de informa????es que tem como finalidade principal coletar, mensurar e evidenciar as transa????es ambientais visando a exercer o importante papel de ve??culo de comunica????o entre a empresa e a sociedade. Neste sentido, as demonstra????es cont??beis merecem aten????o e estudo especiais, haja vista que representam o principal canal de evidencia????o de itens econ??mico-ambientais do qual faz uso a Contabilidade. O objetivo deste trabalho foi o de analisar uma amostra de demonstra????es cont??beis publicadas no Brasil, das empresas Petrobr??s, Braskem, Refap, Copesul, Bunge Fertilizantes, Basf, Petroqu??mica Uni??o e OPP, todas do ramo qu??mico e petroqu??mico, no intuito de verificar como t??m sido evidenciados os investimentos, passivos e custos ambientais pelas referidas empresas. Infelizmente, as demonstra????es cont??beis dessas companhias mostraram-se pouco adequadas ??s novas necessidades dos usu??rios da informa????o cont??bil, e paralelamente, insuficientes para atender ??s exig??ncias da NBC T 15 - Informa????es de Natureza Social e Ambiental, aprovadas pela Resolu????o do Conselho Federal de Contabilidade - CFC n?? 1.003, que entrar?? em vigor a partir de 1?? de janeiro de 2006.
43

Die invloed van werknemerbemagtiging op skofwerkers se werknemerdoeltreffendheid en hul persepsies van die gehalte van hul werklewe

Pieterse, Ferdinandus Lukas Johannes Bartholomeus, 1959- 11 1900 (has links)
Text in Afrikaans, abstract in Afrikaans and English / Die doel van hierdie navorsing was om te bepaal of betekenisvolle verskille bestaan tussen werknemerdoeltreffendheid en persepsies van gehalte van werklewe van bemagtigde en niebemagtigde skofwerkers in die Suid-Afrikaanse petrochemiese bedryf. Skofwerknavorsing het gedurende die afgelope dekade internasionaal toegeneem. Hiermee gepaardgaande het verskeie intervensies ontstaan om die doeltreffendheid van skofwerkers en hulle gehalte van werklewe te bevorder. Deur gebruik te maak van 'n gekombineerde vraelys ("Standard Shiftwork Index") en werklike data ten opsigte van afwesigheid en prestasiebeoordelings, is 'n steekproef van 102 gevalle geanaliseer. 'n 90 persent betroubaarheidinterval is gebruik om waardes ten opsigte van elke veranderlike te bepaal. Daar is bevind dat werknemerbemagtiging weinig invloed het op skofwerkers se werkbywoning. Daar is ook gevind dat werknemerbemagtiging nie lei tot 'n meer positiewe persepsie, by toesighouers, van skofwerkwerkers se algemene werkprestasie nie. Daar is egter bevind dat skofwerkers se persepsies van hulle gehalte van werklewe, ten opsigte van werkdissatisfaksie, chroniese vermoeidheid en tevredenheid met sosiale omstandighede, wel positiefbelnvloed word deur werknemerbemagtiging. Aanbevelings is gemaak ten opsigte van die aanwending van werknemerbemagtiging, as intervensie in skofwerkomgewings, asook vir verdere skofwerknavorsing in Suid-Afrika. / The purpose of this research was to determine if significant differences exist between employee effectiveness and perceptions of quality of working life of empowered and non-empowered shiftworkers in the South-African petrochemical industry. By using the Standard Shiftwork Index and real absenteeism and appraisal data, a sample of 102 cases was analysed. A 90 percent confidence interval was used to determine t-values for variables. It was found that empowerment has little influence on the work attendance of shiftworkers and that empowerment does not lead to more positive perceptions of general work performance of shiftworkers, among their supervisors. It was, however, found that shiftworkers' perceptions of their quality of working life are improved by empowerment in respect of work dissatisfaction, chronic fatigue and satisfaction with social circumstances. Suggestions were made concerning the use of empowerment, as an intervention, in shiftwork environments and for future shiftwork research in South-Africa. / Industrial and Organisational Psychology / M.Comm. (Bedryfsielkunde)
44

Influência do histórico térmico na morfologia de cristais de parafina e nas características reológicas de óleos parafínicos em baixas temperaturas / From the domestic to the institutional home: the perception about work from the perspective of the social caregivers of nursing homes in Curitiba and the metropolitan region

Andrade, Diogo Elias da Vinha 31 August 2017 (has links)
Petrobras / Petróleos parafínicos são complexas misturas de hidrocarbonetos saturados, aromáticos, naftênicos e, em menor quantidade, de componentes que apresentam heteroátomos como resinas e asfaltenos. Em baixas temperaturas, a solubilidade das parafinas em solução diminui e ocorre a precipitação de hidrocarbonetos no petróleo. Devido à cristalização nota-se não apenas o aumento considerável da viscosidade dos petróleos em baixas temperaturas, mas também a deposição de parafina nas paredes internas da tubulação e a gelificação do petróleo nos oleodutos em eventuais paradas da produção. Os trabalhos disponíveis na literatura mostram que os históricos térmico e de cisalhamento influenciam o comportamento mecânico de petróleos parafínicos em baixas temperaturas. No presente trabalho são apresentados resultados da influência da temperatura inicial de resfriamento na temperatura de cristalização, na temperatura de gelificação e na tensão crítica necessária para reiniciar o escoamento de petróleos parafínicos. A temperatura em que o material é submetido antes do resfriamento influencia nas propriedades reológicas do petróleo. A partir da revisão de conceitos de cristalização define-se que para a precipitação do primeiro cristal é necessário a ocorrência de super-resfriamento na solução. Em outras palavras, não é possível que ocorra a cristalização da parafina exatamente na temperatura de equilíbrio sólido-líquido, Teq,SL. É proposta uma metodologia experimental para determinar a temperatura de saturação de óleos parafínicos. A partir de resultados reométricos pode-se notar que a magnitude do superresfriamento influencia a taxa de nucleação e o tamanho final dos cristais precipitados. O tamanho da região metaestável é influenciado pela taxa de resfriamento e pela temperatura inicial do teste. A partir de microscopia de campo claro observa-se que quanto maior o superresfriamento maior o número de cristais formados. Pode-se adiantar que a morfologia e o tamanho dos cristais formados influenciam o comportamento reológico do óleo parafínico em baixas temperaturas. / Waxy crude oil is a complex mixture of hydrocarbons consisting of paraffins, aromatics, naphthenes, asphaltenes and resins. At low temperatures the solubility of high molecular weight components in the oil is decreased and especially the n-paraffins tend to precipitate as crystal structures. These crystals provide a non-Newtonian behavior to the fluid, tend to deposit in the inner surface of pipelines and are responsible for the gelation of the oil when the flow is interrupted. In such cases, the pressure needed to restart the oil flow in subsea pipelines can be much larger than the usual steady-state pressure as the temperature in such environment can be as low as 4 °C. The literature has shown that not only the temperature itself but also the fluid shear and thermal histories have significant influence on the yield stress of waxy crude oils. The current work shows the effect of the initial cooling temperature on the waxy crude oil viscosity, gelation temperature and critical stress. It is showed that the initial cooling temperature affects the mechanical behavior of crude oils at low temperature. It is presented that crystallization is the process where an ordered solid structure is formed from a disordered phase. This process involves two main stages, namely nucleation and crystals growth. As paraffins nucleation is a stochastic process, a supercooling is needed to the onset of this phenomenon. In other words precipitation of crystals could not take place at the solidliquid equilibrium thermodynamic temperature, Teq,SL. Therefore, during the cooling, it is required that the fluid reaches a certain temperature, below the Teq,SL, to initiate the nucleation process. This work proposes an experimental procedure to determine consistently the highest solid-liquid thermodynamic equilibrium temperature. By means of rheometric tests, it is showed that the supercooling affects the nucleation rate and the crystals morphology, and also it is influenced by the cooling rate and the initial cooling temperature. One can conclude that the higher the supercooling the higher the number of crystals and, as consequence, the lower the crystals length. Finally, the crystals morphology and the length affect the mechanical properties of the waxy oil.
45

Influência do histórico térmico na morfologia de cristais de parafina e nas características reológicas de óleos parafínicos em baixas temperaturas / From the domestic to the institutional home: the perception about work from the perspective of the social caregivers of nursing homes in Curitiba and the metropolitan region

Andrade, Diogo Elias da Vinha 31 August 2017 (has links)
Petrobras / Petróleos parafínicos são complexas misturas de hidrocarbonetos saturados, aromáticos, naftênicos e, em menor quantidade, de componentes que apresentam heteroátomos como resinas e asfaltenos. Em baixas temperaturas, a solubilidade das parafinas em solução diminui e ocorre a precipitação de hidrocarbonetos no petróleo. Devido à cristalização nota-se não apenas o aumento considerável da viscosidade dos petróleos em baixas temperaturas, mas também a deposição de parafina nas paredes internas da tubulação e a gelificação do petróleo nos oleodutos em eventuais paradas da produção. Os trabalhos disponíveis na literatura mostram que os históricos térmico e de cisalhamento influenciam o comportamento mecânico de petróleos parafínicos em baixas temperaturas. No presente trabalho são apresentados resultados da influência da temperatura inicial de resfriamento na temperatura de cristalização, na temperatura de gelificação e na tensão crítica necessária para reiniciar o escoamento de petróleos parafínicos. A temperatura em que o material é submetido antes do resfriamento influencia nas propriedades reológicas do petróleo. A partir da revisão de conceitos de cristalização define-se que para a precipitação do primeiro cristal é necessário a ocorrência de super-resfriamento na solução. Em outras palavras, não é possível que ocorra a cristalização da parafina exatamente na temperatura de equilíbrio sólido-líquido, Teq,SL. É proposta uma metodologia experimental para determinar a temperatura de saturação de óleos parafínicos. A partir de resultados reométricos pode-se notar que a magnitude do superresfriamento influencia a taxa de nucleação e o tamanho final dos cristais precipitados. O tamanho da região metaestável é influenciado pela taxa de resfriamento e pela temperatura inicial do teste. A partir de microscopia de campo claro observa-se que quanto maior o superresfriamento maior o número de cristais formados. Pode-se adiantar que a morfologia e o tamanho dos cristais formados influenciam o comportamento reológico do óleo parafínico em baixas temperaturas. / Waxy crude oil is a complex mixture of hydrocarbons consisting of paraffins, aromatics, naphthenes, asphaltenes and resins. At low temperatures the solubility of high molecular weight components in the oil is decreased and especially the n-paraffins tend to precipitate as crystal structures. These crystals provide a non-Newtonian behavior to the fluid, tend to deposit in the inner surface of pipelines and are responsible for the gelation of the oil when the flow is interrupted. In such cases, the pressure needed to restart the oil flow in subsea pipelines can be much larger than the usual steady-state pressure as the temperature in such environment can be as low as 4 °C. The literature has shown that not only the temperature itself but also the fluid shear and thermal histories have significant influence on the yield stress of waxy crude oils. The current work shows the effect of the initial cooling temperature on the waxy crude oil viscosity, gelation temperature and critical stress. It is showed that the initial cooling temperature affects the mechanical behavior of crude oils at low temperature. It is presented that crystallization is the process where an ordered solid structure is formed from a disordered phase. This process involves two main stages, namely nucleation and crystals growth. As paraffins nucleation is a stochastic process, a supercooling is needed to the onset of this phenomenon. In other words precipitation of crystals could not take place at the solidliquid equilibrium thermodynamic temperature, Teq,SL. Therefore, during the cooling, it is required that the fluid reaches a certain temperature, below the Teq,SL, to initiate the nucleation process. This work proposes an experimental procedure to determine consistently the highest solid-liquid thermodynamic equilibrium temperature. By means of rheometric tests, it is showed that the supercooling affects the nucleation rate and the crystals morphology, and also it is influenced by the cooling rate and the initial cooling temperature. One can conclude that the higher the supercooling the higher the number of crystals and, as consequence, the lower the crystals length. Finally, the crystals morphology and the length affect the mechanical properties of the waxy oil.
46

Understanding SHERQ managerial perspectives of the risks and oppotunities in ISO 14001:2015 implementation in Durban, KwaZulu-Natal

Harilal, Laurika 07 1900 (has links)
Text in English with summary and keywords in English and Afrikaans / The International Organization for Standardization - ISO 14001 environmental standard addresses facets of environmental performance. The implementation of ISO 14001:2015 is aligned with various risks and opportunities, the identification and addressing of which is key in the successful implementation of the ISO 14001:2015 certification. The Durban region is a pollution ‘hotspot’ within KwaZulu-Natal. Assessment of the opportunities and risks of ISO 14001:2015 implementation within the region is key as it can potentially assist with proactive mitigation of risks and the effective utilization of opportunities. The aim of the study is to understand SHERQ (Safety, Health, Environmental, Risk and Quality) managerial perspectives of opportunities and risks of ISO 14001:2015 implementation in Durban, KwaZulu-Natal. The following objectives were outlined: To identify ISO 14001 implementation opportunities and risks internationally and nationally by means of an extensive review of international as well as national literature sources, to generate an evaluation framework to assess SHERQ managerial perspectives of risks and opportunities of ISO 14001:2015 implementation within Durban and to analyse SHERQ managerial responses to the ISO 14001:2015 implementation risks and opportunities within the Durban region. The methods included identifying primary opportunities and risks in ISO 14001:2015 from the literature review through an evaluation framework, thereafter, presenting these in questionnaires distributed among SHERQ managers in Durban via email and LinkedIn. Of 62 questionnaires distributed, 42 participants responded. The respondent’s perspectives were assessed through SPSS identifying key risks and opportunities. Objective 1 was achieved through the literature review in which ISO 14001 implementation risks and opportunities were identified. Objective 2 was achieved by generating the evaluation framework which assimilated implementation risks and opportunities. Objective 3 was achieved through the analysis of the responses of respondents to ISO 14001:2015 implementation risks and opportunities. Study results showed that, in line with international reports, 57.2% of all respondents agreed that the maintenance costs of compliance to the standard are high and 76.2% of respondents shared the perspective that company resources are better managed. Respondents were more agreeable to positive statements, indicating opportunities outweighing the risks. Furthermore, despite the risks, there are opportunities from an industry perspective such as increased investor inputs and increased top management involvement. A follow up study is recommended in the Durban region addressing ISO 14001 implementation risks, opportunities, and their investment impacts in order to further hone in on the organizational implications of certification. From an academic standpoint, multiple studies have posited that ISO 14001:2015 implementation resulted in improved financial outcomes but are associated with high implementation costs and it is recommended that a critical cost versus profits analysis into ISO 14001:2015 implementation be undertaken in the Durban region. / Die Internasionale Organisasie vir Standaardisering se ISO 14001-omgewingstandaard spreek fasette van omgewingsprestasie aan. Die implementering van ISO 14001:2015 is gerig op verskeie risiko’s en geleenthede, en die identifisering en aanspreek hiervan staan sentraal tot die suksesvolle implementering van die ISO 14001:2015 - sertifisering. Die Durban-streek is ʼn besoedlingsbrandpunt in KwaZulu-Natal. Evaluering van die geleenthede en risiko’s van die implementering van ISO 14001:2015 binne die streek is van kardinale belang, aangesien dit moontlik kan help met die proaktiewe vermindering van risiko’s en die effektiewe benutting van geleenthede. Die doel van die studie is om SHERQ-bestuursperspektiewe van geleenthede en risiko’s van ISO 14001:2015-implementering in Durban, KwaZulu-Natal, te begryp. Die volgende doelwitte is uiteengesit: Om ISO 14001-implementeringsgeleenthede en risiko’s internasionaal en nasionaal te identifiseer deur middel van ʼn uitgebreide oorsig van internasionale sowel as identifiseer deur middel van ʼn uitgebreide oorsig van internasionale sowel as nasionale literatuurbronne; om ʼn evalueringsraamwerk te genereer om SHERQ-bestuursperspektiewe van geleenthede en risiko’s van die implementering van ISO 14001:2015 te evalueer, en om SHERQ-bestuursreaksies op die ISO 14001:2015-implementeringsrisiko’s en -geleenthede te ontleed. Die metodes het ingesluit die identifisering van primêre geleenthede en risiko’s in ISO 14001:2015 vanuit die literatuurbeoordeling deur middel van ʼn evalueringsraamwerk, waarna dit in vraelyste wat via e-pos en LinkedIn onder SHERQ-bestuurders in Durban versprei is, uiteengesit is. Van die 62 vraelyste wat versprei is, het 42 deelnemers geantwoord. Die perspektiewe van die respondente is beoordeel deur middel van SPSS se identifisering van die belangrikste risiko’s en geleenthede. Doelwit 1 is bereik deur middel van die literatuuroorsig waarin ISO 14001-implementeringsrisiko’s en -geleenthede geïdentifiseer is. Doelwit 2 is bereik deur die evalueringsraamwerk te genereer wat implementeringsrisiko’s en -geleenthede geassimileer het. Doelwit 3 is bereik deur die antwoorde van respondente op ISO 14001:2015 implementeringsrisiko’s en -geleenthede te ontleed. Studieresultate het getoon dat, in ooreenstemming met internasionale verslae, 57,2% van alle respondente dit eens was dat die onderhoudskoste van die nakoming van die standaard hoog is en dat 76,2% van die respondente die perspektief gedeel het dat bronne van die maatskappy beter bestuur word. Respondente het meer met positiewe stellings saamgestem, wat daarop dui dat geleenthede swaarder weeg as die risiko’s. Ten spyte van die risiko’s, is daar ook vanuit ʼn bedryfsperspektief geleenthede, soos verhoogde beleggersinsette en verbeterde hulpbronbestuur. ʼn Opvolgstudie word aanbeveel om ISO 14001-implementeringsrisiko’s en geleenthede en die beleggingsimpak daarvan aan te spreek. Vanuit ʼn akademiese oogpunt het veelvuldige studies aangevoer dat die implementering van ISO 14001:2015 verbeterde finansiële uitkomste tot gevolg het, maar dat dit met hoë implementeringskoste gepaard gaan, en dit word aanbeveel dat ʼn kritieke koste-versus-wins-analise in die implementering van ISO 14001:2015 in die Durban-streek onderneem word. / Environmental Sciences / M. Sc. (Environmental Management)

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