Chevron braced steel frames require large beams to redistribute the unbalanced vertical forces exerted on the beams after brace buckling. A new frame configuration similar to chevron brace was proposed in literature, where zipper columns were attached between mid-spans of the beams from second to top story. During severe ground motion, the unbalanced vertical forces caused by buckling of lower story braces are in this case redistributed to the upper story braces by these zipper columns. Consequently, all story braces buckle successively from first to top story brace instead of concentration of inelastic action in one story. This system has been improved recently by adding an elastic hat truss between the top two stories to prevent formation of a full zipper mechanism and to prevent collapse. Two-phase numerical study is undertaken in this study to evaluate the response of chevron and suspended zipper braced frames, where the objective of the first phase is to observe the change in the performance of the configurations for different sets of initial imperfection and rotational spring stiffness values. Rotational springs are added at the end nodes of the braces to represent the effects of gusset plates and initial imperfection is assigned to the mid-length of the braces to achieve proper buckling behavior. The objective of the second phase is to compare the response of chevron and suspended zipper brace frames. For this purpose, three, nine and twenty-story buildings are designed for both brace configurations. The designed buildings are analyzed under static and dynamic loadings.

This Master’s thesis deals with the influence of process parameters in forward extrusion on the initiation of chevron cracks in material by numerical simulation. Solution was executed by ANSYS 11 and the influence of fiction, angle of reduction, reduction and numbers of extrusion operations was solved for the 12 050.3 steel by the chosen conditions.

The purpose of this thesis is to deal with the initiation of chevron cracks in forward extrusion. Using numerical simulation, the ability of selected fracture models which prognosticates the initiation of chevron cracks is observed. The influence of process parameters is studied (friction, reductions in cross section and angles of reduction) on the initiation and diffusion of damage. Solutions was executed by Abaqus for material 12 050.

The Mississippi River is one of the most intensively managed and altered river systems in the world. The alterations to the Mississippi have been largely made to meet navigation demands and mitigate floods. River training has been undertaken using rock structures, commonly referred to as river training structures (RTS), to modify the shape of the river to maintain the Congressional mandated navigation channel dimensions. In addition to maintaining the navigation channel, newer RTS such as chevrons, have been claimed to be designed as an improvement to the previously existing dikes. They are considered to be tools of improving riverine habitat by increasing physical habitat heterogeneity within the highly engineered and consequently uniform river channel. Thus, to evaluate the differences in physical habitat heterogeneity created by the two RTS; a dike and a chevron, this study models and compares the physical aquatic habitats created along the Middle Mississippi River near Grand Tower, Illinois. The hydraulic modelling software HEC-RAS has been used to develop a two-dimensional model of the study area containing the RTS using detailed 2 m- resolution topobathy digital elevation model (DEM), U.S Geologic Survey’s National Land Cover Database (NLCD), an existing one-dimensional model of the Mississippi and hydrologic data from several hydrologic monitoring stations for the years 2008-2016. Depth and velocity grids were extracted from the HEC-RAS model for three different discharge conditions; 0.5 mean annual flow (MAF) with 40% exceedance probability, MAF with 80% exceedance probability and 1.5 MAF with 15% exceedance probability were used to develop and categorize physical habitat distribution maps of the study area using ArcGIS. The modeled physical aquatic habitat patches were assessed at three buffer distances of 30 m, 90 m, and 150 m from the RTS. The area Simpson diversity and Jaccard similarity indices were calculated for the different discharge conditions and associated habitat mosaics. The distribution of physical habitat modeling revealed a variation in the pattern of habitat patches between the dike and chevron. For the chevron dike evaluated in this study, very-slow deep habitat patches are created in the inner portion of the chevron and slow deep patches around the exterior of the structure which extend both up and downstream of the structure. The dike created slow-deep habitat patches along the structure, very-slow deep patches on the riverbank edge and fast- deep patches on the river side edge. Evaluation of physical habitat patch diversity in relation to the distance from the RTS revealed the highest diversity index values were found within the first 30 m buffer and generally decrease with distance away from the structure. Comparison of the Jaccard index values in vicinity of the two evaluated RTS suggest the habitat patch diversity are similar for both structures at 0.5 MAF and 1.5 MAF flow conditions (index value ranging between 0.60-0.87). However, for the MAF flow conditions the Jaccard index suggests there is more physical habitat patch diversity in the vicinity of the chevron relative to the dike. The modeling results suggest both physical habitat patch richness and diversity declines with an increase in discharge. The decline in physical habitat patch richness and diversity with discharge conditions were greater for the dike relative to the chevron, thus while the chevron retains more types of habitat patches with increase in discharge the diversity indices are still higher for the dike. The modeling also suggests both RTS have created and maintain shallow water habitat (SHW) and overwintering habitat patches (OWH) for the flow conditions evaluated in this study. These habitat patches are utilized by fish species at various life stages. Larger area of OWH habitats; 30% of total area by dikes and 35% of total area by chevrons are created in comparison to SWH; 10% by dike and 7% by chevron. The modeling results show that both the dike and chevron evaluated in this study are associated with and likely maintain ecologically relevant habitats and substantially contribute to physical habitat diversity. If the physical characteristics of the RTS investigated here are similar to other dikes and chevrons along the Mississippi River, the results of this study supports the secondary management objective for these structures, increase in physical aquatic habitat patch diversity, is likely being achieved.

The exploration of Microelectromechanical systems (MEMS) represents a crucial aspect in the advancement of modern science and technology. They offer low-cost solutions to miniaturize numerous devices. The increasing use of MEMS applications in biological research has created a pressing need for reliable micromanipulation tools. In this context, microgrippers have emerged as promising tools for the precise handling and characterization of biological samples. This thesis presents a novel biocompatible microgripper that utilizes electrothermal actuation integrated with a rotary capacitive position sensor. To overcome the limited displacement possibilities associated with electrothermal actuators, this microgripper incorporates conjugate surface flexure hinges (CSFH). These hinges enhance the desired tweezers output displacement. The designed microgripper can in principle manipulate biological samples ranging in size from 15 to 120 μm. Based on the sensitivity calculation of the rotary capacitive position sensors, the sensitivity of the displacement measurement is 102 fF/μm. By employing a kinematics modeling approach based on the pseudo-rigid-body method (PRBM), an equation for the displacement amplification factor is developed, and this equation is subsequently verified through FEM-based simulations. By comparing the amplification ratio value obtained from the analytical modeling and simulations, there is an excellent match, with a relative difference of only ~1%, thus demonstrating the effectiveness of the PRBM approach in modeling the kinematics of the structure under investigation. In addition to this, by using analytical modeling based on finite elements method (FEM), the design of the electrothermal actuator and the heat dissipation mechanism is optimized. FEM-based simulations are used to validate the theoretical modeling, demonstrating good agreement between the displacements derived from analytical modeling and simulations. The temperature difference (∆T) across a range from room temperature to 278°C exhibits a relative difference of ~2.8%. Moreover, underpass technology is implemented to ensure that electrical signals or disturbances from other parts of the device, such as the electrothermal actuation system, do not interfere with the operation and integrity of the gripping mechanism. Ultimately, the microgripper is fabricated using conventional MEMS technology from a silicon-on-insulator (SOI) wafer through the deep reactive ion etching (DRIE) technique. The integration of theoretical modeling, simulations, and practical fabrication highlights a compelling approach that has the potential for transformative applications in the field of micromanipulation and biological sample handling. Furthermore, we propose a C-shaped structure with a curved beam mechanism to improve the movement provided by the thermal actuators. The design of experiment (DOE) method is used to optimize the geometrical parameters of our proposed device. Analytical modeling based on Castigliano's second theorem and finite element method (FEM) simulations are used to predict the behavior of the symmetrical C-shaped structure; the results are in good agreement. The MEMS-based rotational structures are fabricated on silicon-on-insulator (SOI) wafers using bulk micromachining and deep reactive ion etching (DRIE). The fabricated devices are tested; our findings reveal that our proposed MEMS rotational structure outperforms the symmetrical lancet structure by 28% in terms of delivered displacement. Furthermore, the experimental results agree well with those obtained through numerical analysis.

Neste trabalho foi medida a tenacidade à fratura de quatro ligas fundidas com composição química base do aço AISI M2 – uma de composição química convencional (liga I), e as demais modificadas por adições de nitrogênio (liga II), cério (liga III) e antimônio (liga IV) – submetidas a tratamentos térmicos visando a decomposição do carboneto M2C, a esferoidização e engrossamento dos carbonetos produto M6C e MC, em altas temperaturas e por diversos tempos. A metodologia empregada nesta avaliação da tenacidade à fratura foi a dos corpos de prova curtos com entalhe chevron segundo ASTM E 1304-97, de forma a superar a necessidade do pré-trincamento por fadiga, procedimento de difícil controle e custoso em materiais como os aços rápidos temperados e revenidos. Verificou-se que a metodologia utilizada para obtenção e ensaio de corpos de prova chevron foi de fácil execução (comparada à metodologia convencional) permitindo grande número de experimentos. Para verificar a consistência dos resultados, em algumas condições, também se utilizou a metodologia convencional segundo a ASTM E 399-90, cujo pré-trincamento foi feito utilizando os procedimentos propostos por Harris e Dunegan. Os resultados obtidos para os aços fundidos foram correlacionados com os obtidos para outros aços rápidos convencionais (VM2, M2 Thyssen) e um aço rápido sinterizado (SINTER 23). A microestrutura foi caracterizada utilizando-se técnicas de ataques metalográficos diferenciais, metalografia quantitativa manual e computadorizada e microscopia eletrônica de varredura. A avaliação microestrutural indica que não ocorreu precipitação eutética do carboneto M6C, em nenhuma das ligas fundidas. O carboneto M2C apresenta morfologia tanto irregular (plaquetas – tipo 1) quanto regular-complexa (lamelas – tipo 2). As ligas I, III e IV, apresentaram a predominância da morfologia tipo 1 enquanto que a liga II modificada pelo nitrogênio, apresentou apenas a morfologia tipo 2. O carboneto MC apresentou-se com morfologia regular-complexa. Medidas do espaçamento interdendrítico indicam que não houve influência significativa dos elementos modificadores sobre este parâmetro. Ensaios de resistência à flexão, indicam pouca influência dos elementos modificadores, mas forte influência dos tratamentos térmicos sobre o limite de resistência à ruptura transversal do aço fundido. Em todas as ligas, a resistência à flexão cresceu com o tempo de tratamento a 1200°C, bem como com a temperatura de decomposição em tratamentos por 2 horas. Análise das fraturas por microscopia eletrônica de varredura indicou que o crescimento das trincas se deu na região interdendrítica. O aço convencional apresentou resistência à ruptura transversal muito superior à dos aços fundidos. Os ensaios de tenacidade à fratura apresentaram resultados compatíveis com a literatura para os aços AISI M2 convencional e SINTER 23. Os resultados obtidos para o aço fundido, indicam queda nos valores de tenacidade à fratura nos materiais tratados a 1050°C com o avanço do tempo de tratamento; pouca variação dos valores com o tempo nas amostras tratadas a 1150°C; e aumento significativo da tenacidade à fratura com o tempo de tratamento a 1200°C. Os valores de tenacidade obtidos para os aços rápidos fundidos foram mais elevados que os obtidos para os materiais trabalhados e para o material sinterizado. / Fracture Toughness of four cast alloys with chemical composition based on the High-Speed Steel AISI M2 were measured. One of the alloys (alloy I) had the conventional AISI M2 composition, while the other three were modified by the addition of N (alloy II), Ce (alloy III) and Sb (alloy IV). The cast alloys were heat-treated in order to promote the decomposition of the M2C carbide as well as spheroidize and coarsen the product M6C e MC carbides. The method chosen for measuring fracture toughness was based on the use of short rod and bar chevron notched samples, according to ASTM E1304 – 97, in order to evade the need for fatigue pre-cracking, notoriously difficult for High Speed Steels quenched and tempered. The chevron-notch method proved straightforward and allowed for successful testing a great number of specimens. Conventional compact sample fracture toughness, according to ASTM E 399-90, with pre-cracking obtained using Harris-Dunegan drop-weight procedure, was used to validate the results. The results for cast alloys were compared with conventionally produced High Speed Steels (VM2, M2 Thyssen) and with a powder metallurgy High Speed Steel (SINTER 23). Microstructural characterization was performed using selective etching of polished surfaces, manual and automated quantitative metallography and SEM. Microstructural evaluation of as-cast alloys showed that there was no eutectic precipitation of M6C carbides. The M2C carbides show an irregular eutectic morphology (Type 1- plates) as well as a regular-complex eutectic morphology. Measurements of interdendritic spacing did not detect any effect of the modification. The bending test rupture strengths did not vary with the addition of modifying elements, but increased with the time and temperature of decomposition, spheroidization and coarsening of carbides. Rupture strengths increased with the heat-treatment time at 1200°C as well as with increasing temperatures for 2 h heat-treatments. SEM examination of the fracture surfaces showed that crack preferential growth path was interdendritical. Conventional High Speed Steels tested in bending presented better results for the rupture strength than cast steels. Fracture toughness results for M2 conventional steels and for the SINTER 23 steel were similar to the results from the literature. Fracture toughness results obtained for cast steels diminished with increasing decomposition time at 1050°C, did not change much with increasing decomposition time at 1150°C, increased markedly withy increasing decomposition times at 1200°C. The fracture toughness results for the as-cast steels were higher than the results obtained for the wrought steels and for the powder metallurgy steel.

Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2018-02-09T16:20:16Z No. of bitstreams: 1 Nadia Vitoria Schurkim.pdf: 1334833 bytes, checksum: a149e06207c121e89e8a083ad1ee9cd9 (MD5) / Made available in DSpace on 2018-02-09T16:20:17Z (GMT). No. of bitstreams: 1 Nadia Vitoria Schurkim.pdf: 1334833 bytes, checksum: a149e06207c121e89e8a083ad1ee9cd9 (MD5) Previous issue date: 2017-10-23 / The object of the present study is the Chevron case, an accident occurred in Campos dos Goytacazes, 107 km from the coast of the State of Rio de Janeiro, in the Brazilian Exclusive Economic Zone, between November 2011 and March 2012, which caused damages to the environment due to the oil exploration activity, focusing on issues relevant to the application of criminal law in maritime areas, highlighted by the denunciation of the federal public ministry and judicial decisions handed down in criminal proceedings whose application and outlines are not peaceful, which justifies the relevance of this study. Throughout this research, the maritime domain, sovereignty and jurisdiction of the Brazilian State in the Exclusive Economic Zone (EEZ) and the Continental Shelf (CS) will be analyzed. The problem is focused on the identification of the sovereignty of Brazil as a Coastal State, of the sea, sea surface and subsoil, the application of its legislative and judicial powers; in the verification if the EEZ and CS are part of the Brazilian maritime territory; in identifying the applicable legal regime in case of environmental crimes arising from the exploitation of oil in these maritime areas; extraterritoriality or territoriality of criminal law. The systematized study of the national and international legal system, through concepts of International Law, Criminal Law and Environmental Law, showed that the conflicts of interpretations observed in the case occur because the legal regime of EEZs and CS, established in UNCLOS III, when dealing with the distinction between rights of sovereignty and the jurisdiction of the coastal State does not provide clear definitions of maritime borders, providing a variety of interpretations. / O objeto do presente estudo consiste na análise do Caso Chevron, acidente ocorrido no Campos dos Goytacazes, a 107 Km do litoral do Estado do Rio de Janeiro, na denominada Zona Econômica Exclusiva brasileira, entre novembro de 2011 e março de 2012, que causou danos ao meio ambiental em decorrência da atividade de exploração de petróleo, tendo como foco as questões pertinentes à aplicação da lei penal nos espaços marítimos, destacadas da denúncia do órgão ministerial federal e das decisões judiciais proferidas no processo criminal cuja aplicação e contornos não são pacíficos, o que se justifica a relevância desse estudo. Ao longo dessa pesquisa, o domínio marítimo, a soberania e a jurisdição do Estado Brasileiro na Zona Econômica Exclusiva (ZEE) e na Plataforma Continental (PC) serão objeto de análise. A problemática concentra-se na identificação da soberania do Brasil, enquanto Estado Costeiro, do mar, da superfície e do subsolo marítimos, da aplicação de seus poderes legislativos e judiciários; na verificação se a ZEE e a PC integram o território marítimo brasileiro; na identificação do regime jurídico aplicável em caso de ocorrência de crimes ambientais decorrentes da exploração de petróleo nesses espaços marítimos; na extraterritorialidade ou da territorialidade da lei penal. O estudo sistematizado do ordenamento jurídico nacional e internacional, por meio de conceitos do Direito Internacional, Direito Penal e Direito Ambiental, demonstrou que os conflitos de interpretações observados no caso ocorrem porque o regime jurídico das ZEE e PC, estabelecidos na CNUDM III, ao tratar da distinção entre direitos de soberania e jurisdição do Estado costeiro não traz definições claras sobre as fronteiras marítimas, proporcionando diversidade de interpretações.

Neste trabalho foi medida a tenacidade à fratura de quatro ligas fundidas com composição química base do aço AISI M2 – uma de composição química convencional (liga I), e as demais modificadas por adições de nitrogênio (liga II), cério (liga III) e antimônio (liga IV) – submetidas a tratamentos térmicos visando a decomposição do carboneto M2C, a esferoidização e engrossamento dos carbonetos produto M6C e MC, em altas temperaturas e por diversos tempos. A metodologia empregada nesta avaliação da tenacidade à fratura foi a dos corpos de prova curtos com entalhe chevron segundo ASTM E 1304-97, de forma a superar a necessidade do pré-trincamento por fadiga, procedimento de difícil controle e custoso em materiais como os aços rápidos temperados e revenidos. Verificou-se que a metodologia utilizada para obtenção e ensaio de corpos de prova chevron foi de fácil execução (comparada à metodologia convencional) permitindo grande número de experimentos. Para verificar a consistência dos resultados, em algumas condições, também se utilizou a metodologia convencional segundo a ASTM E 399-90, cujo pré-trincamento foi feito utilizando os procedimentos propostos por Harris e Dunegan. Os resultados obtidos para os aços fundidos foram correlacionados com os obtidos para outros aços rápidos convencionais (VM2, M2 Thyssen) e um aço rápido sinterizado (SINTER 23). A microestrutura foi caracterizada utilizando-se técnicas de ataques metalográficos diferenciais, metalografia quantitativa manual e computadorizada e microscopia eletrônica de varredura. A avaliação microestrutural indica que não ocorreu precipitação eutética do carboneto M6C, em nenhuma das ligas fundidas. O carboneto M2C apresenta morfologia tanto irregular (plaquetas – tipo 1) quanto regular-complexa (lamelas – tipo 2). As ligas I, III e IV, apresentaram a predominância da morfologia tipo 1 enquanto que a liga II modificada pelo nitrogênio, apresentou apenas a morfologia tipo 2. O carboneto MC apresentou-se com morfologia regular-complexa. Medidas do espaçamento interdendrítico indicam que não houve influência significativa dos elementos modificadores sobre este parâmetro. Ensaios de resistência à flexão, indicam pouca influência dos elementos modificadores, mas forte influência dos tratamentos térmicos sobre o limite de resistência à ruptura transversal do aço fundido. Em todas as ligas, a resistência à flexão cresceu com o tempo de tratamento a 1200°C, bem como com a temperatura de decomposição em tratamentos por 2 horas. Análise das fraturas por microscopia eletrônica de varredura indicou que o crescimento das trincas se deu na região interdendrítica. O aço convencional apresentou resistência à ruptura transversal muito superior à dos aços fundidos. Os ensaios de tenacidade à fratura apresentaram resultados compatíveis com a literatura para os aços AISI M2 convencional e SINTER 23. Os resultados obtidos para o aço fundido, indicam queda nos valores de tenacidade à fratura nos materiais tratados a 1050°C com o avanço do tempo de tratamento; pouca variação dos valores com o tempo nas amostras tratadas a 1150°C; e aumento significativo da tenacidade à fratura com o tempo de tratamento a 1200°C. Os valores de tenacidade obtidos para os aços rápidos fundidos foram mais elevados que os obtidos para os materiais trabalhados e para o material sinterizado. / Fracture Toughness of four cast alloys with chemical composition based on the High-Speed Steel AISI M2 were measured. One of the alloys (alloy I) had the conventional AISI M2 composition, while the other three were modified by the addition of N (alloy II), Ce (alloy III) and Sb (alloy IV). The cast alloys were heat-treated in order to promote the decomposition of the M2C carbide as well as spheroidize and coarsen the product M6C e MC carbides. The method chosen for measuring fracture toughness was based on the use of short rod and bar chevron notched samples, according to ASTM E1304 – 97, in order to evade the need for fatigue pre-cracking, notoriously difficult for High Speed Steels quenched and tempered. The chevron-notch method proved straightforward and allowed for successful testing a great number of specimens. Conventional compact sample fracture toughness, according to ASTM E 399-90, with pre-cracking obtained using Harris-Dunegan drop-weight procedure, was used to validate the results. The results for cast alloys were compared with conventionally produced High Speed Steels (VM2, M2 Thyssen) and with a powder metallurgy High Speed Steel (SINTER 23). Microstructural characterization was performed using selective etching of polished surfaces, manual and automated quantitative metallography and SEM. Microstructural evaluation of as-cast alloys showed that there was no eutectic precipitation of M6C carbides. The M2C carbides show an irregular eutectic morphology (Type 1- plates) as well as a regular-complex eutectic morphology. Measurements of interdendritic spacing did not detect any effect of the modification. The bending test rupture strengths did not vary with the addition of modifying elements, but increased with the time and temperature of decomposition, spheroidization and coarsening of carbides. Rupture strengths increased with the heat-treatment time at 1200°C as well as with increasing temperatures for 2 h heat-treatments. SEM examination of the fracture surfaces showed that crack preferential growth path was interdendritical. Conventional High Speed Steels tested in bending presented better results for the rupture strength than cast steels. Fracture toughness results for M2 conventional steels and for the SINTER 23 steel were similar to the results from the literature. Fracture toughness results obtained for cast steels diminished with increasing decomposition time at 1050°C, did not change much with increasing decomposition time at 1150°C, increased markedly withy increasing decomposition times at 1200°C. The fracture toughness results for the as-cast steels were higher than the results obtained for the wrought steels and for the powder metallurgy steel.

Thesis (MBA)--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The Chevron Cape Town refinery was constructed in 1996 with a crude capacity of 100,000 barrels per day (bpd). The focus of the unit is production and meeting the nameplate market demand. The project environment for the refinery is that of maintenance and gradual upgrade. The majority of projects handled are small capital projects. The aim of this research is to identify what the success criteria for project management should be for projects carried out within the small capital projects department of Chevron's Cape Town refinery. An important distinction to make is that this study looks at project management success and not project success, although the aspects of project success will be discussed to highlight how closely related the two concepts are. Project success is not directly proportional to project management success and neither is project management success directly proportional to project success. In the past decades, project management success was usually indicated by the project completion within the time, cost and performance constraints (Kerzner, 2004:29). This has now evolved to understanding all the objectives of the project. Project management can still be deemed successful even if it did not meet all the objectives of the project and vice versa, as long as there are mutual trade-offs agreed to by the developer (project manager) and the client. White and Fortune (2002:1-11) conducted a survey to identify common criterion used for defining project management success. The three criteria identified for judging project success are completion on time, within the budget and to performance (specification). Project management success has been found to be a very difficult topic to define. This research report shown that project management success needs to be moved beyond the iron-triangle to other criteria like safety and meeting the objectives of the client. What was evident was that criteria, factors, dimensions and measures are concepts widely used by researchers and it is hoped that these topics. A very interesting discovery during my first interview was that project management success comes in three phases or parts, which are pre-delivery, delivery and post-delivery. What was evident from this research was that the criteria for project management success need to be established up front before the project gets to the delivery phase. There is no way that one can measure project management success when the success criteria one is looking for at the end of the project have not been established up front. The case study is summarised using the diagram in chapter five showing the new project management success criteria that needs to be adopted by the refinery. Future research into project management success criteria could include a survey which could go out the whole refinery and not just the representative sample who were interviewed for this report which could confirm the project management criteria found in this report. / AFRIKAANSE OPSOMMING: Die Chevron Kaapstad raffinadery is in 1996 gestig met 'n ruolie kapasiteit van 100,000 vate per dag. Die fokus van die eenheid is produksie en om aan die marknavraag te voldoen. Die projekomgewing van die raffinadery is instandhouding en mettertydse opgradering van die raffinadery. Die meerderheid van projekte wat hanteer word is klein-kapitaalprojekte. Die doel van hierdie navorsing is om te identifiseer wat die sukseskriteria vir projekbestuur behoort te wees vir projekte wat binne die klein-kapitaaldepartement van Chevron se Kaapstad raffinadery behartig word. 'n Belangrike onderskeid om te maak is dat hierdie studie na projekbestuursukses kyk en die projeksukses nie, alhoewel die aspekte van projeksukses ook bespreek sal word om uit te lig hoe naby verwant die twee konsepte aan mekaar is. Projeksukses is nie direk proporsioneel tot projekbestuursukses nie en omgekeerd. In die afgelope dekades was projekbestuursukses gewoonlik aangedui deur die afhandeling van die projek binne die tydsraamwerk, koste en prestasiebeperkinge (Kerzner, 2004:29). Hierdie konsep het intussen uitgebrei na 'n verstaan van al die doelwitte van die projek. Projekbestuur kan steeds as suksesvol beskou word al het dit nie aan al die doelwitte van die projek voldoen nie, en omgekeerd, solank as wat daar wedersydse toegewings deur beide die ontwikkelaar (projekbestuurder) en die kliënt gemaak word. White en Fortune (2002:1-11) het 'n opname gemaak om die algemene kriteria te identifiseer wat gebruik word om projekbestuursukses te definieer. Die drie kriteria wat uitgewys is om 'n projek te evalueer, is afhandeling van die projek binne die tydsraamwerk, koste en prestasiebeperkinge. Projekbestuursukes is 'n baie moeilike onderwerp om te definieer. Hierdie navorsingsverslag wys dat projekbestuursukses verby die “yster-driehoek” moet beweeg om ander kriteria soos veiligheid en die voldoening aan die kliënt se doelwitte, in te sluit. Wat duidelik na vore gekom het is dat kriteria, dimensies en metings konsepte is wat wyd deur navorsers gebruik word. 'n Baie interessante ontdekking gedurende die eerste onderhoud was dat projekbestuursukses in drie fases of dele voorkom, naamlik voor-lewering, lewering en na-lewering. Wat duidelik uit die navorsing is, is dat die kriteria vir projekbestuursukses voor die aanvang van 'n projek vasgestel moet word, voordat die projek die afleweringsfase bereik. Daar is geen manier wat projekbestuursukes gemeet kan word wanneer die sukseskriteria wat aan die einde van 'n projek gesoek word, nie aan die begin vasgestel is nie. Die gevallestudie word opgesom deur die diagram in hoofstuk vyf te gebruik wat die nuwe projekbestuursukseskriteria aandui wat deur die raffinadery aanvaar moet word. Toekomstige navorsing in projekbestuursukseskriteria kan 'n opname insluit wat aan die hele raffinadery gestuur kan word en nie net die verteenwoordigende steekproef met wie daar vir hierdie verslag se doeleindes onderhoud gevoer is om die projekbestuurkriteria van hierdie verslag te bevestig nie.

<p>Proteins are among the most abundant biological macromolecules. The cellular machinery is coupled to exact structural shape and properties of the more than 100 000 different proteins. Still, proteins can sometimes completely change their character and as a result trigger neuro degenerative disease. Exactly what happens is yet poorly understood but misfolding and aggregation leading to toxic gain of function is probable causes, i.e. the protein adopts new noxious properties. In 1993 the protein superoxide dismutase (SOD) was found to be associated with the neuro degenerative disease ALS. Up to date more than 100 mutations in SOD have been associated with ALS. However, the mutations are scattered all over the structure and no common denominator for the disease mechanism has been found. </p><p>This work has been focused on the molecular mechanism of the toxic gain-of - function of mutant SOD from the perspective of protein folding and structural stability. To facilitate the studies of SOD and its ALS associated mutations, an expression system resulting in increased copper content was developed. Coexpression with the copper chaperone for superoxide dismutase (yCCS) leads to increased expression levels, especially for the destabilised ALS mutants. Through thermodynamic studies, I show that with the exception of the most disruptive mutations the holo protein is only marginally destabilised, whereas all mutations show a pronounced destabilisation on the apo protein. Kinetic studies suggest further that the dimeric apoSOD folds via a three-state process where the dimerisation proceeds via a marginally stable monomer. The apoSOD monomer folds by a two-state process. The disulphide bond is not critical for the folding of the apoSOD monomer although it contributes significantly to its stability. Interestingly, in the absence of metals, reduction of the disulphide bond prevents the formation of the dimer. A mutation can affect the protein stability in various ways: either from destabilisation of the monomer (case 1), weakening of the dimer interface (case 2) or, in the worst case, from a combination of both (case 1+2). Thus, therapeutic strategies to prevent the noxious effects of mutant SOD must include both mechanisms. An important finding in this study is that we can see a correlation between the stability for each mutation and the mean survival time. This could be an opening in the development of therapeutic substances that counteract the defect in SOD upon mutation.</p>