Thesis (M.Sc.)(Metallurgy)--University of Pretoria, 2004. / Includes summary. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Iowa, 2007. / Supervisor: Aloysius Klingelhutz. Includes bibliographical references (leaves 132-153).

No description available.

Abstract Title: Lean Production in The Public Sectors Level: Final assignment for Master of Science in Business Administration. Authors: Simon Mårtensson and Ramnpreet Kaur Maan Supervisor: Stig Sörling and Tomas Källquist. Examiner: Lars-Johan Åge Date: 2015 – June. Aim: The use of Lean Production in the public sector is increasing and there are still opportunities for improvement that contributes to a higher customer value. According to previous research that has been done, there is a lack of research in the field of Lean production in the public sector. Thus, the aim of this study is to create an understanding of how Lean production as a concept can help to influence employees to work with continuous improvements and customer value in the public sector. Method: The study has a hermeneutic perspective as a starting point where the substance is studied from an operator approach. We have chosen to build our study with the help of deduction starting with a theoretical framework and then go into the empirical framework. The foundation is built around a case study with a qualitative approach through the semi-structural interviews. Collecting data and analysis has been done through coding to achieve the most essential of it. Result & Conclusion: The study indicates that continuous improvement and customer value are tools that the public sector largely works with. To obtain this the respondents, which represent the authorities, uses Lean meetings, Lean board and shows concrete examples of changes that have a positive impact on the company. Suggestions for future research: We believe that further research on how employees are affected by the work for continuous improvements and customer value in the private sector is of great interest. Contribution of the thesis: The study shows that it is needed to motivate employees so that they will work on continuous improvements and customer value. In connection with this, there are tools that the public sector can use to promote the motivation, which is education and feedback. Key words: Lean Production, employees, continuous improvements, customer value, the public sector.

Thesis (MScEng) -- Stellenbosch University, 2004. / ENGLISH ABSTRACT: The development of a small, cost effective short range FM-CW radar as well as the design and optimization of a double helix antenna is discussed. The FM-CW radar operates at Sband (2450 - 2550 MHz) and is limited at a maximum transmitted power of 5 dBm. The system is required to detect reflections from objects up to a 30 m range. This was made possible largely by the effective high gain antenna design and improved system isolation between the transmitted and received signals. The complete design process from fundamental requirements, through various simulations and system analysis to the final electronic circuit is discussed. The design was also built and measured in the laboratory and initial field measurements were taken. The following aspects were considered: Relation between the beat frequency and various FM-CW radar system parameters based on the theory, preliminary measurements and simulations. Radar component assessment and design. Design of a low cost Lange coupler that isolates the system's transmit and receive signals, which operates as a 90° hybrid and is used to feed a dual-fed circularly polarized patch antenna. A circularly polarized patch antenna and double helix antenna were designed, built and measured in an anechoic chamber. The antennas were implemented in the final radar system and compared on the basis of their contribution to the system's performance. Integrating the final radar system on a circular 60 mm diameter PCB with a double helix antenna mounted on top. The final radar system is able to measure range up to 40 m and meets all the design requirements. The signal processing of the measured beat frequency, however, can be taken further. / AFRIKAANSE OPSOMMING: Die ontwikkeling van 'n klein, koste effektiewe kort-afstand FM-CW radar, sowel as die onwerp en optimalisering van 'n dubbele heliks-antenna word bespreek. Die FM-CW radar werk by S-band (2450 - 2550 MHz) en is beperk tot 'n maksimum uitsaaidrywing van 5 dBm. Van die stelsel word vereis om weerkaatsings van voorwerpe tot op 'n afstand van 30 m waar te neem. Dit is grootliks moontlik gemaak deur die hoë aanwins antenna-ontwerp en verbeterde isolasie tussen die stelsel se uitsaai- en ontvangseine. Die volledige ontwerpsproses van die fundamentele vereistes af tot die finale elektroniese stroombaan word bespreek. Verskeie simulasies andstelselanalises is gebruik om die finale FM-CW radar te realiseer. Die ontwerp is vervolgens in die laboratorium gebou en gemeet en aanvangsveldmetings is geneem. Die volgende aspekte is in nagevors: Verband tussen die puls-frekwensie en verskeie FM-CW radar stelselparameters gebaseer op die teorie, inleidende metings en simulasies. Ontleding van verskeie radarkomponente en -stelselontwerp. Ontwerp van 'n lae koste Lange-koppelaar met die doelom die stelsel se uitsaai- en ontvangseine te isoleer. Die Lange-koppelaar dien as 'n 90° hibriede wat gebruik word om 'n dubbele-voer sirkulêr gepolariseerde mikrostrookantenna aan te dryf. Verder is 'n sirkulêr gepolariseerde mikrostrook-antenna en 'n dubbele heliksantenna ontwerp en opgemeet in 'n anarqoïese kamer. Beide antennas is geïmplimenteer in die finale radarstelsel en is vergelyk op grond van hulle rol in die stelsel se funksionering. Die finale stelsel is geïntegreer en gebou op 'n ronde 60 mm deursnit PCB met 'n dubbele helix-antenna bo-op gemonteer. Die finale radarstelsel kan afstand tot op 40 meter bepaal en voldoen aan al die gestelde vereistes. Seinverwerking van die gemete puls-frekwensie kan nog verder ontwikkel word.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Small, medium and micro enterprises are important contributors to the economic and socioeconomic development of South Africa. However, most enterprises struggle to become established. The high rate of failure is due to a lack of access to finance, poor managerial and technical skills, and also the competitive business environment. The focus of this research report is on the development of a continuous and sustainable internal process improvement roadmap that provides skill constrained small business managers with strategic and technical support, in order to make their organisations more competitive in the current business environment, without expensive consultation. The first step toward the development of the roadmap is discussed as a ten step basic process improvement cycle, based on an interpretation of the PDCA cycle. These ten steps provide most of the methods that are needed for practical implementation of improvement activities. However, this approach needs strategic support in order to ensure that improvement activities focus on the critical improvement opportunities. The second step regards the identification of strategic support, and additional improvement methods, to align improvement activities toward the critical improvement opportunities, which represent a common goal. Three methodologies are discussed as individual roadmaps to determine the crucial aspects that can be integrated into a holistic management roadmap, which accommodates practical improvement. These methodologies are lean thinking, theory of constraints, and the six sigma philosophy. The final roadmap is then developed, based on the principle that perspectives can be used to develop the perception of people toward improvement. Different perspectives are identified from the studied improvement methodologies, and the execution of improvement activities is then supported with the basic process improvement cycle. The perspectives are categorised into three main perspectives. First, the organisational perspective provides an overview of the philosophy, people, and process. Second, the primary process perspective provides an overview of the critical process aspects; value, throughput, and quality. Third, the secondary process perspective connects these critical process aspects in terms of effectiveness, agility, and efficiency. The roadmap is then completed when management can transcend above perspective. / AFRIKAANSE OPSOMMING: Klein, medium en mikro ondernemings is belangrike bydraers tot die ekonomiese en sosio-ekonomiese ontwikkeling van Suid-Afrika. Meeste ondernemings sukkel egter om gevestig te raak. Die hoë koers van mislukking is weens ‘n gebrek aan finansiële toegang, swak bestuurs en tegniese vaardighede, en die mededingende sake-omgewing. Die fokus van hierdie navorsingsverslag is op die onwikkeling van ‘n deurlopende en volhoubare interne proses verbeterings padkaart wat klein besigheid bestuurders verskaf met strategiese en tegniese ondersteuning, sonder duur konsultasie, ten einde hul organisasies meer mededingend the maak in die huidige sake-omgewing. Die eerste stap vir die onwikkeling van die padkaart word bespreek as ‘n tien stap basiese verbetering siklus, gebaseer op ‘n intrepretasie van die PDCA siklus. Hierdie stappe voorsien meeste van die metodes wat nodig is vir praktiese implementering van verbetering aktiwiteite. Die benadering moet egter strategies ondersteun word om te verseker dat verbetering aktiwiteite op die kritieke verbeterings geleenthede fokus. Die tweede stap word bespreek vir die identifisering van strategiese ondersteuning, asook addisionele verbetering metodes, om verbetering aktiwiteite in lyn te bring met kritiese verbeterings geleenthede, wat ‘n gemeenskaplike doel verteenwoordig. Drie metodieke word bespreek as individuele padkaarte om die deurslaggewende aspekte te bepaal wat geïntegreer kan word in ‘n bestuurs padkaart, wat praktiese verbetering akkomodeer. Die metodieke is “lean thinking”, “theory of constraints”, en “six sigma”. Die finale padkaart word dan ontwikkel, gebasseer op die beginsel dat perspektiewe gebruik kan word om mense se persepsie van verbetering te ontwikkel. Verskillende perspektiewe is geïndentifiseer vanuit die verbetering metodieke, en die uitvoering van verbeterings aktiwiteite word dan ondersteun met die basiese verbeterings siklus. Die perspektiewe is ingedeel in drie hoof perspektiewe. Eerste, die organisatoriese perspektief verskaf ‘n hoë vlak oorsig van die filosofie, mense, en proses. Tweede, die primêre proses perspektief verskaf ‘n oorsig van die kritiese proses aspekte; waarde, deurset, en kwaliteit. Derde, die sekondêre proses perspektief verbind die proses aspekte in terme van effektiwiteit, aanpasbaarheid, en doeltreffendheid. Die padkaart word dan eindelik voltooi wanneer die bestuur perspektief te bowe kan kom.

Made available in DSpace on 2014-06-11T19:27:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-05Bitstream added on 2014-06-13T20:16:12Z : No. of bitstreams: 1 martins_ms_me_guara.pdf: 4378638 bytes, checksum: 5ab218d0c5345113e4a7e43df186b4af (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho tem por objetivo apresentar uma nova proposta de produção do aço para molas de válvulas para motores de combustão interna SAE 9258. Atualmente, este aço é produzido pela rota de lingotamento convencional, e pretende-se adotar o processo de lingotamento contínuo, mantendo-se todas as características mecânicas e metalúrgicas do aço produzido convencionalmente. Cuidados especiais durante o processo de refino secundário (fase líquida) foram levados em consideração para que sejam obtidas inclusões de silicatos deformáveis, essenciais para se conseguir uma vida em fadiga segura para as molas durante a vida útil do motor. Para avaliar essas características do aço foram feitas análises metalográficas da microestrutura em amostras na fase de processamento do aço (fio-máquina) e na fase final do processo (arames), realizados ensaios de tração, ensaios de fadiga axial em corpos-de-prova padronizados (ASTM E 466), ensaios de fadiga por flexão rotativa no arame (Nakamura test), ensaio de fadiga nas molas e análise das superfícies de fratura por fadiga com auxílio de microscopia eletrônica de varredura (MEV), para as duas rotas de produção (lingotamento convencional e contínuo). Os resultados obtidos mostram que não há diferenças com relação a microestrutura, propriedades mecânicas e comportamento em fadiga do aço na fase final de produção (arame) e na forma de produto (molas). Por outro lado, os resultados obtidos para o aço na fase intermediária do processamento (fiomáquina) mostram diferenças com relação à microestrutura, (presença de maior quantidade de carbonetos nas amostras do lingotamento contínuo), e menor redução de área com a consequente redução da resistência à fadiga. / This paper aims to present a new proposal for production of steel for valve springs for internal combustion engines SAE 9258. Currently this steel is produced by ingot casting route, and intended to adopt the continuous casting process, maintaining all the mechanical and metallurgical characteristics of the steel produced conventionally. Special attention during the process of refinement (liquid phase) were taken into account are obtained for silicate inclusions deformable essential to achieving a safe fatigue life for the springs during the life of the engine. To evaluate these features were made of steel metallographic analysis of microstructure in specimens during processing of steel (wire rod) and the final stage (wires) performed tensile tests, axial fatigue tests on specimens standard (ASTM E 466), fatigue tests in rotating bending on the wire (Nakamura test), the fatigue test the springs and examination of the areas of fatigue fracture with the aid of scanning electron microscopy (SEM) for the two production routes (ingot and continuous casting). The results show no differences with respect to microstructure, mechanical properties and fatigue behavior of steel in the final stages of production (wire) and the product form (spring). Moreover, the results obtained for steel in the intermediate stage of processing (wire rod) show differences from the microstructure (the larger amount of carbides in the samples of the continuous casting), lower area reduction with the consequent reduction resistance to fatigue.

abstract: A new analytical method is proposed for measuring the deuterium to hydrogen ratio (D/H) of non-stoichiometric water in hydrous minerals via pyrolysis facilitated gas-chromatography - isotope ratio mass spectrometry (GC-IRMS). Previously published analytical methods have reported a poorly understood nonlinear dependence of D/H on sample size, for which any accurate correction is difficult. This sample size effect been variously attributed to kinetic isotope fractionation within the mass spectrometer and peripheral instruments, ion source linearity issues, and an unstable H_3^+-factor or incorrect H_3^+-factor calculations. The cause of the sample size effect is here identified by examinations of individual chromatograms as well as bulk data from chromatographic peaks. It is here determined that it is primarily an artifact of the calculations employed by the manufacturer's computer program, used to both monitor the functions of the mass spectrometer and to collect data. Ancillary causes of the sample size effect include a combination of persistent background interferences and chromatographic separation of the isotopologues of molecular hydrogen. Previously published methods are evaluated in light of these findings. A new method of H_3^+-factor and D/H calculation is proposed which makes portions of the Isodat software as well as other published calculation methods unnecessary. Using this new method, D/H is measured in non-stoichiometric water in chert from the Cretaceous Edwards Group, Texas, as well as the Precambrian Kromberg Formation, South Africa, to assess hydrological conditions as well as to estimate the maximum average surface temperature during precipitation of the chert. Data from Cretaceous chert are consistent with previously published data and interpretations, based upon conventional analyses of large samples. Data from Precambrian chert are consistent with maximum average surface temperatures approaching 65°C during the Archean, instead of the much lower temperatures derived from erroneous methods of sample preparation and analysis. D/H is likewise measured in non-stoichiometric water in silicified basalt from the Precambrian Hooggenoeg Complex, South Africa. Data are shown to be consistent with D/H of the Archean ocean similar to present day values. / Dissertation/Thesis / M.S. Geological Sciences 2011

Currently, construction companies have shown a need to adopt process improvement systems in order to function competitively in the market. However, civil construction, compared to the manufacturing, still has deficiencies relating to the incorporation of new improvement systems. Thus, the use of Kaizen Events (KE) is one of the main mechanisms used to perfect processes during the production (execution) phase of a product, ensuring enhanced performance and added value to the client. The present research sought to evaluate a method for adopting KE in the construction sector. The data-gathering tools used were a questionnaire and a focus group where academics and/or experts who fit a specific profile participated. A methodological strategy for the development of the work was adopted under the approach of Design Science Research (DSR) and the theoretical referential was developed from a Systematic Literature Review (SLR). Improvements were made to the method to improve its applicability and functionality in real life scenarios using the results obtained. Accordingly, the results show horizons for future research on KE in civil construction. / Revisión por pares