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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.
111

Additive   manufacturing   of   spare   parts   for   the  mining   industry  a   pilot   study   on   business   impact   from   an   aftermarket   perspective.

Vingerhagen, Kristian, Alfredsson, Julia January 2021 (has links)
The   purpose   of   this   pilot   study   was   to   identify   and   evaluate   different   business   cases   for   Epiroc’s  Parts   &   Services   Division   (PSD)   regarding   the   use   of   additive   manufacturing   (AM),   also   known   as  3D   printing,   for   their   spare   parts   within   the   mining   industry.    This   study   presents   an   approach   for  how   spare   parts   promising   for   AM   can   be   identified   and   shows   the   difficulties   with   AM.   The   study  follows   the   design   research   methodology   (DRM)   standard   for   research   within   product   and   process  development.   Through   interviews   and   literature   searches,   a   "top-down"   approach   was   applied.   A  developed   cost-benefit   model   accompanied   this   approach   and   was   used   to   identify   and   evaluate  potential   spare   parts   for   AM   from   Epiroc’s   current   spare   parts   portfolio.   The   results   were   evaluated  as   promising   for   several   of   the   spare   parts   in   terms   of   reduced   manufacturing,   procurement,   tool  cost,   and   lead   time   reduction,   which   results   in   increased   uptime   for   the   customer.   With   reduced   lead  times,   the   availability   increases   for   the   customer,   who   may   increase   Epiroc’s   sales   and   aftermarket  revenues   in   the   long   run.   There   is   also   great   potential   for   reducing   the   costs   for   warehousing,   where  spare   parts   of   low   demand   can   have   their   stocks   reduced   or   eliminated   by   securing   supply   through  on-demand   manufacturing.   Although   many   exciting   business   cases   have   been   identified   and  evaluated,   it   has   been   acknowledged   that   CNC-machining   in   many   cases   is   the   cheaper   alternative.  Despite   this,   it   is   worth   investing   in   AM   from   a   strategic   point   of   view   as   it   is   seen   as   a   tool   for   the  future.   Before   it   can   be   adopted   and   implemented,   Epiroc   should   do   test   trials   with   companies  offering   AM   services.   These   can   be   used   to   update   and   tune   the   cost-benefit   model   accordingly   to  increase   its   reliability   and   validity.   The   model   could   also   be   developed   further   to   incorporate   AM’s  additional   benefits,   such   as   weight   and   material   reduction   through   design   for   additive  manufacturing   (DfAM). / Syftet   med   denna   förstudie   var   att   identifiera   och   utvärdera   olika   affärsmöjligheter   för   Epirocs   Parts  &   Services-division   (PSD)   gällande   användningen   av   additiv   tillverkning   (AM),   även   känd   som  3D-printning,   för   deras   reservdelar   inom   gruvindustrin.   Denna   studie   presenterar   ett  tillvägagångssätt   för   hur   reservdelar   passande   för   AM   kan   identifieras   och   visar   på   svårigheterna  med   AM.   Studien   följer   "design   research   methodology"   (DRM),   vilket   kan   översättas   till  designforsknings-metodologin,   som   är   vanligt   förekommande   vid   forskning   inom   produkt-   och  processutveckling.   Genom   intervjuer   och   litteratursökningar   tillämpades   en   "top-down"-metod.  Detta   åtföljdes   av   en   utvecklad   kostnadsnyttomodell   som   tillsammans   användes   för   att   identifiera  och   utvärdera   potentiella   reservdelar   för   AM   från   Epirocs   nuvarande   reservdelsportfölj.   Resultaten  utvärderades   som   lovande   för   flertalet   av   reservdelarna   vad   gäller   reducerad   kostnad   för  tillverkning,   inköp,   verktyg   och   minskad   ledtid,   vilket   resulterar   i   ökad   drifttid   för   kunden.   Med  minskade   ledtider   ökar   tillgängligheten   för   kunden,   som   kan   öka   Epirocs   försäljning   och  eftermarknadsintäkter   på   lång   sikt.   Det   finns   också   en   stor   potential   i   att   minska   kostnaderna   för  lagerhållning,   där   reservdelar   med   låg   efterfrågan   kan   få   sina   lager   att   reduceras   eller   elimineras  genom   att   säkra   utbudet   genom   tillverkning   vid   behov.   Även   om   många   intressanta  affärsmöjligheter   har   identifierats   och   utvärderats   har   det   uppmärksammats   att   CNC-bearbetning   i  många   fall   kan   vara   det   billigare   alternativet.   Trots   detta   är   det   värt   att   investera   i   AM   ur   en  strategisk   synvinkel   eftersom   det   ses   som   ett   verktyg   för   framtiden.   Innan   AM   kan   anammas   och  implementeras   bör   Epiroc   göra   testförsök   med   företag   som   erbjuder   AM-tjänster.   Dessa   kan  användas   för   att   uppdatera   och   justera   kostnadsnyttomodellen   i   enlighet   med   detta   för   att   öka   dess  validitet   och   reliabilitet.   Modellen   kan   också   utvecklas   vidare   för   att   införliva   AM:s   ytterligare  fördelar,   såsom   vikt-   och   materialreduktion   genom   design   för   additiv   tillverkning   (DfAM).
112

Women in mining : a conceptual framework for gender issues in the South African mining sector / Dorothea Botha

Botha, Dorothea January 2013 (has links)
The Mineral and Petroleum Resources Development Act (28 of 2002) (MPRDA) and the accompanied Broad-based Socio-economic Empowerment Charter aimed to rectify previous inequalities and disadvantages in the mining sector and specifically provide for the inclusion of women in core mining activities. According to the Act and the Charter, the mining industry was supposed to reach a quota of 10% women in core mining activities by 2009. The amendment of the Broad-based Socio-economic Empowerment Charter for the South African Mining and Minerals Industry (launched in 2010) set further requirements in terms of employment equity targets; the Charter requires a 40% historically disadvantaged South African representation in core and critical skills by 2015. Although well intended, the establishment of gender equality in the male-dominant mining sector remains one of the biggest equity challenges in the country and numerous problems accompany the deployment of women in core mining activities. Against this background, the main objective of the study was to critically analyse gender issues in the mining sector and to subsequently develop a conceptual framework that will enable the mining sector to contribute to and ensure the sustainable employment of women in the mining sector. A literature review was done, firstly to provide an understanding of persistent inequalities in society and the workplace, and secondly to gain an in-depth understanding of the variables that have an impact on women in the world of work in general and in the mining sector specifically. An empirical study was conducted to determine and investigate relevant gender-related issues in the mining sector. Quantitative (questionnaires) and qualitative (semi-structured interviews, focus group discussions and direct observation) research paradigms were used. From the literature review as well as the empirical study, it is evident that the deployment of women in core positions is still accompanied by various challenges, not only for managers but also for male co-workers as well as the women themselves. Although the numbers of women in the South African mining industry have risen, there is still a long way to go to successfully and sustainably ensure women‟s participation in the industry. Through the literature study and the empirical research, it became clear that various factors need to be considered for the successful and sustainable deployment of women in the mining sector. The study concludes by making recommendations and offering a conceptual framework, with the main pillars being company policies, workplace opportunities, infrastructure facilities, physical ability, health and safety and workplace relations. This framework can be implemented and used by various stakeholders in the mining sector to contribute to the successful and sustainable deployment of women in the mining sector. / PhD (Sociology), North-West University, Potchefstroom Campus, 2014
113

Women in mining : a conceptual framework for gender issues in the South African mining sector / Dorothea Botha

Botha, Dorothea January 2013 (has links)
The Mineral and Petroleum Resources Development Act (28 of 2002) (MPRDA) and the accompanied Broad-based Socio-economic Empowerment Charter aimed to rectify previous inequalities and disadvantages in the mining sector and specifically provide for the inclusion of women in core mining activities. According to the Act and the Charter, the mining industry was supposed to reach a quota of 10% women in core mining activities by 2009. The amendment of the Broad-based Socio-economic Empowerment Charter for the South African Mining and Minerals Industry (launched in 2010) set further requirements in terms of employment equity targets; the Charter requires a 40% historically disadvantaged South African representation in core and critical skills by 2015. Although well intended, the establishment of gender equality in the male-dominant mining sector remains one of the biggest equity challenges in the country and numerous problems accompany the deployment of women in core mining activities. Against this background, the main objective of the study was to critically analyse gender issues in the mining sector and to subsequently develop a conceptual framework that will enable the mining sector to contribute to and ensure the sustainable employment of women in the mining sector. A literature review was done, firstly to provide an understanding of persistent inequalities in society and the workplace, and secondly to gain an in-depth understanding of the variables that have an impact on women in the world of work in general and in the mining sector specifically. An empirical study was conducted to determine and investigate relevant gender-related issues in the mining sector. Quantitative (questionnaires) and qualitative (semi-structured interviews, focus group discussions and direct observation) research paradigms were used. From the literature review as well as the empirical study, it is evident that the deployment of women in core positions is still accompanied by various challenges, not only for managers but also for male co-workers as well as the women themselves. Although the numbers of women in the South African mining industry have risen, there is still a long way to go to successfully and sustainably ensure women‟s participation in the industry. Through the literature study and the empirical research, it became clear that various factors need to be considered for the successful and sustainable deployment of women in the mining sector. The study concludes by making recommendations and offering a conceptual framework, with the main pillars being company policies, workplace opportunities, infrastructure facilities, physical ability, health and safety and workplace relations. This framework can be implemented and used by various stakeholders in the mining sector to contribute to the successful and sustainable deployment of women in the mining sector. / PhD (Sociology), North-West University, Potchefstroom Campus, 2014
114

The use of strategy tools by chartered accountants in the South African mining industry

Grebe, Lindie 11 1900 (has links)
The purpose of this study was to explore the strategising practices of chartered accountants (CAs) in the South African mining industry. Few studies have dealt with the practical skills CAs employ when they engage in strategising practices and, in particular, a gap could be identified on how CAs engage with strategy tools during strategising. Approximately two thirds of all directors in South Africa are CAs and only 11% of directors who are CAs also hold master‟s degrees in business administration. The question then arises of how do CAs engage with strategy tools during strategising? This study applied key concepts of social practice theory to explore the strategising practices of CAs from a strategy-as-practice perspective. The strategy-as-practice perspective entails studying strategy practitioners within their social constructs. The context of this study was the South African mining industry, a landscape seen as an essential part of the South African economy. An exploratory qualitative research design was applied whereby one-on-one interchanges during individual interviews provided rich, detailed descriptions of how CA strategists use strategy tools when they engage in strategising practices. The social nature of the practices and praxis of strategy practitioners from a strategy-as-practice perspective constantly changes. As such, the current study was conducted from a constructivist paradigm to describe the narrative reality of the strategy practitioners as they engage with strategy tools. The findings of the study portrayed participants as bricoleurs of strategy tools, i.e. craftspeople who adapted and interpreted strategy tools from an accounting perspective to serve the requirements of the situation they face. / Financial Accounting / M. Phil. (Accounting Sciences)
115

The development of a strategic business plan to grow the mining and minerals division of Kellogg Brown & Root into Sub-Saharan Africa

Carvelas, Wray Anthony 12 1900 (has links)
Thesis (MBA (Business Management))--University of Stellenbosch, 1999. / ENGLISH ABSTRACT: Globally the mining and minerals market is experiencing a decline. With this decline, focus is turning to Africa as an unexplored mineral wealth. In terms of global exploration expenditure, Africa is said to be experiencing the highest percentage growth of any other regional budget. The Halliburton company is reputed to be the premier source for the engineering and construction of refineries, chemical plants, and pipelines along with office buildings, infrastructure systems, government facilities, and much more. The South African office has recently established a mining and minerals division, which has experienced certain measures of success, however, a failure of the division appears to be the total lack of a significant growth strategy. This has resulted in the division becoming a one-client business. The Sub-Saharan market is characterised by unique challenges, which require a strong culture aligned with its market environment, strategic choice and distinctive competencies to be successful in the market. The purpose of this study project is primarily to make a contribution to the formulation of strategic direction in order to obtain practical implementation guidelines given the unique opportunities and challenges presented in this market. The formulation of the strategy for the mining and minerals business unit is achieved firstly be analysing the Sub-Saharan market, the dominant economic traits, and conducting a full industry and competitive analysis. Secondly, organisation situation analysis of Kellogg Brown & Root is conducted in order to assess the competitive positioning of the firm and distinct capabilities that the firm possesses, and those necessary for success in the market. This will include conducting an analysis of the internal strengths and weaknesses, of the company, and the external opportunities and threats facing the company. From the analyses conducted, strategic challenges are identified and suggestions are made to address these challenges. A strategic intent is proposed together with a mission statement, and a strategic and financial statement of objectives is developed. These statements of intent are not intended to prescribe to the firm and it's employees what the strategic approach should be, but to form the basis of further discussions and research and should not give way to misleading and unwarranted interpretations. The strategy formulated is superimposed onto the corporate strategy and no major discordance is evident. From the analyses conducted and strategy formulation process, suggestions are made that could provide manageable guidelines for the final implementation of the strategic business plan for the minerals division. / AFRIKAANSE OPSOMMING: Tans word 'n afname in die mynbou en minerale mark wêreldwyd ondervind. As gevolg van hierdie afname het die fokus na Afrika as 'n onverkende minerale rykdom verskuif. In terme van wêreldwye eksplorasie besteding, word beweer dat Afrika die hoogste persentasie groei ten opsigte van enige ander streeksbegroting ondervind. Die Halliburton maatskappy word beskou as 'n vername bron vir die ontwikkeling en konstruksie van raffinaderye, chemiese aanlegte, pyplyne, geassosieerde kantoor geboue, infrastrukture, regerings fasiliteite en vele meer. Die Suid Afrikaanse kantoor het onlangs 'n mynwese en minerale afdeling op die been gebring wat al 'n mate van sukses ondervind het. Dit wil egter voorkom asof 'n tekortkoming van die afdeling 'n gebrek aan 'n doelgerigte groei strategie is. Dit het tot gevolg gehad dat die afdeling tot 'n een-kliënt-saak verval het. Die Sub-Sahara mark word gekenmerk deur unieke uitdagings wat 'n sterk kultuur inlyn met die mark omgewing, strategiese keuses en relevante bevoegdhede verg om suksesvol in die mark te wees. Die hoofdoel van hierdie studie is om 'n bydrae te maak tot die formulering van 'n strategiese koers met die doel om praktiese implementerings riglyne daar te stel, met inagneming van die unieke geleenthede en uitdagings wat in die mark bestaan. Die formulering van 'n strategie vir die mynwese en minerale besigheidsektor word eerstens verkry deur 'n analise van die Sub-Sahara mark, dominerende ekonomiese eienskappe en 'n ontleding van die industriele en mededingende omgewing. Tweedens word 'n organisaie situasie analise van Kellogg Brown & Root uitgevoer om die kompeterings posisie, huidige kenmerkende bekwaamhede en die wat benodig word vir sukses in die mark, van die maatskappy vas te stel. Dit sluit 'n ontleding van die interne swak en sterk punte van die maatskappy, asook die eksterne geleenthede en bedreigings vir die maatskappy in. Vanuit hierdie analise word strategiese uitdagings geidentifiseer en word voorstelle gemaak om hierdie uitdagings aan te spreek. 'n Strategiese oogmerk, tesame met 'n doelwitstelling word voorgestel, en 'n strategiese en finansiele doelstelling word ontwikkel. Die doel van hierdie studie projek is nie om aan die maatskappy en sy werknemers 'n strategiese benadering voor te skryf nie, maar om die basis te vorm vir verdere bespreking en navorsing. Die studie moet nie aanleiding gee tot verkeerde en misleidende vertolkings nie. Die geformuleerde strategie is ook met die huidige korporatiewe strategie vergelyk en geen noemenswaardige verskille is ooglopend nie. Vanuit die analise en die strategiese formuleringsproses word praktiese riglyne voorgestel vir die implementering van die strategiese besigheidsplan vir die mynwese en minerale afdeling.
116

Job characteristics, wellness and work-home interaction in the mining industry / Gary Robert Oldfield

Oldfield, Gary Robert January 2006 (has links)
The mining industry is driven by performance and intense working environments, accompanied by high demands, hazardous working conditions and socially undesirable working hours. These factors could impact on the interaction between work and home, as well as contributing to health problems of employees. The objectives of this research were to test the construct validity, construct equivalence and reliability of a work-home interaction measuring instrument, the Survey Work-Home Interaction - Nijmegen (SWING), to determine if work-home interaction differences exist between different demographical groups, and to test a structural model of job characteristics (job demands and job resources), ill health and negative work-home interference. Random samples (n = 320) were taken from employees working in the mining industry (gold, platinum and phosphate mines) in the Gauteng, North West and Northern provinces. The SWING, a self-developed job characteristics questionnaire and an adapted version of the General Health Questionnaire were administered. Structural equation modelling, descriptive statistics, Cronbach alpha coefficients, Pearson product-moment correlations, multivariate analysis of variance (MANOVA) and one-way analysis of variance (ANOVA) were used to analyse the data. Structural equation modelling confirmed the four-factor structure of the SWING and the construct equivalence for two language and ethnic groups. The four factors showed acceptable internal consistencies. Statistically significant differences were found based on age, ethnicity, gender, qualification, marital and parental status, language, flexibility at work and whether individuals had a partner with a paid job. Regarding the structural model, the results showed that job demands and job resources have an impact on ill health, and that ill health is associated with negative WHI. It was also found that job demands and job resources have a direct relationship with negative WHI on their own, but when both high demands and a lack of resources are present, only an indirect relationship with negative WHI exists though ill health. / Thesis (M.Com. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2007
117

South African transnational mining companies and environmental impact assessment in the Democratic Republic of Congo

Dechuvi, Kasemire Rosine 02 1900 (has links)
A research report submitted to the Faculty of Science, in partial fulfilment of the requirements for the degree of Master of Science, University of the Witwatersrand, Johannesburg. February 2015. / This study examines the practice of environmental impact assessments (EIAs) by South African mining transnational companies (TNCs) operating some mining projects in the Democratic Republic of Congo (DRC). It analyses whether and how South African mining TNCs carry out EIAs for their mining projects in the DRC, especially whether they follow (1) the DRC EIA policies, (2) the South African EIAs policies (3) international EIA policies, or (4) internal company policies. It also examines what motivates the companies to follow any of the policy path, by assessing whether financial or policy regimes evaluations motivates the TNCs to follow the certain path. Through the case studies of AngloGold Ashanti and Metorex (Pty) Limited, the study demonstrates the complexity involved in making decisions on choosing a policy path to follow which confronts TNCs. The conclusion we draw from this study is that TNCs do not follow a single policy path in carrying out EIAs but integrate a number of policies and standards and the integration of various policies and standards demands highly qualified and well trained staff as well as availability of an enabling scientific and research infrastructure within the host country.
118

Proposição de um método para desenvolvimento de sistema de apoio à decisão baseado em modelos de simulação computaciona na indústria de mineração

Camargo, Luis Felipe Riehs 31 May 2013 (has links)
Submitted by William Justo Figueiro (williamjf) on 2015-07-28T20:09:32Z No. of bitstreams: 1 24d.pdf: 11997633 bytes, checksum: 49b4850d8bb8e37ede1bf6f00a0ab501 (MD5) / Made available in DSpace on 2015-07-28T20:09:32Z (GMT). No. of bitstreams: 1 24d.pdf: 11997633 bytes, checksum: 49b4850d8bb8e37ede1bf6f00a0ab501 (MD5) Previous issue date: 2013-05-31 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As decisões são essenciais para a manutenção e o crescimento da firma em ambiente incerto e competitivo. As decisões são, igualmente, importantes e difíceis de serem tomadas devido à incerteza dos seus potencias resultados. Identificou-se uma carência, na literatura de modelagem e simulação, de métodos para suportar decisões que envolvem as operações e que integrem o sistemas de produção e de manufatura e apresentem o desempenho do sistema de modo antecipado, em termos da qualidade do produto e produtividade do sistema. Esta tese apresenta um método para a construção de um sistema de apoio à decisão, baseado no pensamento sistêmico e em simulação computacional. O método possibilita avaliar de forma dinâmica, estocástica, circular e sistêmica o impacto das decisões da cadeia produtiva na área de mineração frente ao fenômeno da degradação e da variabilidade da qualidade da matériaprima. A aplicação do método em um caso real mostrou-se factível. Além disso, ilustrou-se situações em que o modelo de simulação foi utilizado para suportar decisões. A pesquisa demonstra, ainda, através de um modelo computacional, o efeito da degradação da qualidade da matéria-prima no desempenho do sistema produtivo. / Decisions are essential for the maintenance and growth of the firm in competitive and uncertain environment. Decisions are also important and difficult to be taken due to the uncertainty of their future potential results. This dissertation tries to fill a gap in the literature of modeling and simulation methods to support operations decisions and setting operating policies in the operations. There are few approaches at the specialized OR/MS literature that integrate the production system and the manufacturing system and provide system performance in terms of quality the product and productivity of the system. This dissertation presents a method for the construction of a decision support system, based on systems thinking (soft OR) and computer simulation (hard OR). The method allows evaluating dynamically, stochastic and systemic the impact of the decisions of the supply chain in the mining area and deal with the phenomenon of degradation and variability in the quality of the raw material. The application of the method on a real case demonstrated to be feasible. The dissertation also illustrated situations in which the simulation model was used to support decisions at Samarco Company. The study further demonstrates, with the computational model developed, the effect of the degradation of the quality of raw material in the overall system performance.
119

The classification of inland salt lakes in Western Australia

Gregory, Stacey J January 2007 (has links)
Inland salt lakes in Western Australia have been used by the mining industry for the disposal of excess water generated during the mining process. However, the impact of these operations on the salt lakes is poorly understood. This is mainly due to the lack of information on the biota and chemistry for the lakes. The main aim of this project was to develop a classification system for inland salt lakes of Western Australia based on abiotic and biotic factors such as sediment and water quality, invertebrates and algae to determine lakes with unique or significant features. Water and sediments collected from the salt lakes were generally characterised by an alkaline pH, high salinity and the majority of lakes being dominated by sodium and chloride. Concentrations of some metals were also high, particularly in surface water. A high degree of variation in water and sediment quality was demonstrated both within and between the study lakes. In addition, these parameters were shown to be influenced by geography, geology, stage of the hydrocycle within which the lake was sampled and the occurrence of dewatering discharge. Biota in the salt lakes must be able to cope in a harsh environment, adjusting to temporary water regime, high temperature, and high salinity. As such, the species richness of these systems is generally low. Diatoms (a group of algae) and invertebrates were investigated among the biota. A total of 56 diatom species were recorded from 24 lakes. The most common species were Amphora coffeaeformis, Hantzschia aff. baltica and Navicula aff. incertata. These species were shown to have broad tolerances to environmental variations. Sediment chemistry explained variations in diatom community structure, with zinc, moisture content and cobalt having the greatest and negative influence. / In terms of invertebrates, a total of 101 invertebrate taxa were recorded from 13 lakes in this study. Crustacea dominated and the greatest number of taxa was from the genus Parartemia. There were some differences in invertebrate community structure between lakes, most likely reflecting the high degree of speciation, and poor dispersal mechanisms of certain key species. Community structure was influenced by water quality, with phosphorus, bicarbonate and magnesium contributing to the variations in community structure. Among the 43 lakes chosen for this study a total of 17 lakes had received, or are currently receiving dewatering discharge. Sites receiving dewatering discharge generally reported higher concentrations of salts, nutrients and some metals in both water and sediments compared to natural lakes. Species richness of biota such as diatoms and invertebrates was lower at the lakes receiving dewatering discharge. However, the impact was generally localized within the pooled area of dewatering discharge. Also, despite these impacts, there appears to be signs of amelioration by flushing events. Currently there are no guidelines for water and sediment chemistry for inland salt lakes in Western Australia. Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines are the most relevant available. Concentrations of cadmium, cobalt, chromium, copper, lead, nickel and zinc in surface water of the natural inland salt lakes were shown to exceed ANZECC guideline values. / Comparison with the relevant ANZECC sediment guidelines showed that they were applicable to the salt lakes, with the exception of nickel and chromium which were naturally high in the salt lake sediments. Classification of data using multivariate analysis was done for both dry and wet phases of the hydroperiod. Six groups were delineated for the sediment and diatom data, and four groups were defined for the water quality and invertebrate data. It was common for sites from particular lakes to fall in more than one group as a result of the variability in these systems. There are a number of practical applications of this system for the mining industry and it may be used as a predictive tool for determining the impact of dewatering discharge and highlighting unique salt lakes within the Goldfields of Western Australia.
120

Validation of a heat stress index and hydration of workers in tropical Australia

Miller, Veronica Susan January 2007 (has links)
In many parts of Australia the climate is such that people are working long hours in the heat. Consequences of excessive environmental heat stress range from reduction in safety due to impairment of concentration, to heat illness, which in extreme cases can be fatal. A critical factor in tolerance of workers to environmental heat stress is their level of hydration. Maximising productivity without compromising the health and safety of the work force requires quantification of the degree of stress posed by the thermal environment. For this purpose a number of heat stress indices have been developed. A recently introduced index is the Thermal Work Limit (TWL), which has been widely adopted and implemented in the underground mining industry in Australia. The field use of TWL and protocols in the mining industry with resultant reduction in heat illness and lost production is a practical endorsement of the index, and its validity under controlled conditions has been confirmed by a preliminary study. The further work needed to complete this validation forms part of this thesis. TWL was found to reliably predict the limiting workload in the controlled environment, reinforcing the validity of the algorithm and its application in the workplace. To date TWL has largely been used in the underground environment, however as the algorithm is equally applicable to the above ground environment where radiant heat forms a significant component of the thermal load, field studies were carried out at mining installations in the Pilbara region of Western Australia to evaluate this application of the index. The current industry standard index of heat stress is the Wet bulb Globe Temperature (WBGT). / The shortcomings of this index are widely acknowledged and in practice it is frequently ignored as it is seen to be unnecessarily conservative in many situations. The sensitivity of TWL to the cooling effect of air movement implied that TWL would be more relevant than WBGT as a predictor of the impact of environmental heat stress in outdoor work environments and this was supported by the results. On the strength of this, recommended management protocols linked to TWL similar to those already in place in many underground workplaces, were developed for the management of thermal risk in outdoor work environments. Maintaining adequate hydration is the single most important strategy to counteract the effects of thermal stress. No heat stress index can protect workers from the combined effects of dehydration and thermal stress. To document the hydration status of the outdoor workforce in the Pilbara, the hydration level of groups of workers was assessed from the specific gravity of their urine. To further evaluate whether the fluid replacement behaviour of the workers is adequate to replace fluids lost in sweat, a fluid balance study was carried out to quantify average fluid intakes and sweat fluid losses. The majority of workers were found to be inadequately hydrated at the start of the shift and their fluid intakes were in general well below the requirements to replace sweat losses - let alone improve hydration. Recommendations for fluid intakes based on documented rates of sweat loss are included in the thesis. Based on the findings of this study workable management strategies have been recommended to minimise the risk to outdoor workers in thermally stressful environments.

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