122 resultados para Underground Mines


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The mining industry faces three long term strategic risks in relation to its water and energy use: 1) securing enough water and energy to meet increased production; 2) reducing water use, energy consumption and emissions due to social, environmental and economic pressures; and 3) understanding the links between water and energy, so that an improvement in one area does not create an adverse effect in another. This project helps the industry analyse these risks by creating a hierarchical systems model (HSM) that represents the water and energy interactions on a sub-site, site and regional scales; which is coupled with a flexible risk framework. The HSM consists of: components that represent sources of water and energy; activities that use water and energy and off-site destinations of water and produced emissions. It can also represent more complex components on a site, with inbuilt examples including tailings dams and water treatment plants. The HSM also allows multiple sites and other infrastructure to be connected together to explore regional water and energy interactions. By representing water and energy as a single interconnected system the HSM can explore tradeoffs and synergies. For example, on a synthetic case study, which represents a typical site, simulations suggested that while a synergy in terms of water use and energy use could be made when chemical additives were used to enhance dust suppression, there were trade-offs when either thickened tailings or dry processing were used. On a regional scale, the HSM was used to simulate various scenarios, including: mines only withdrawing water when needed; achieving economics-of-scale through use of a single centralised treatment plant rather than smaller decentralised treatment plants; and capturing of fugitive emissions for energy generation. The HSM also includes an integrated risk framework for interpreting model output, so that onsite and off-site impacts of various water and energy management strategies can be compared in a managerial context. The case studies in this report explored company, social and environmental risks for scenarios of regional water scarcity, unregulated saline discharge, and the use of plantation forestry to offset carbon emissions. The HSM was able to represent the non-linear causal relationship at the regional scale, such as the forestry scheme offsetting a small percentage of carbon emissions but causing severe regional water shortages. The HSM software developed in this project will be released as an open source tool to allow industry personnel to easily and inexpensively quantify and explore the links between water use, energy use, and carbon emissions. The tool can be easily adapted to represent specific sites or regions. Case studies conducted in this project highlighted the potential complexity of these links between water, energy, and carbon emissions, as well as the significance of the cumulative effects of these links over time. A deeper understanding of these links is vital for the mining industry in order to progress to more sustainable operations, and the HSM provides an accessible, robust framework for investigating these links.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Video installation, Metrolpolis: Part I-III, using 1-channel HD video with surround sound. At the end of the first decade of the twenty–first century, contemporary culture appears increasingly seduced and absorbed by apocalyptic reveries. Scientists are racing to cryo-preserve genetic material from animals and plant matter in underground bunkers, while filmmakers use the spectacle of computer-generated imagery (CGI) to speculate on the outcomes from dramatic climate change, that we are not yet ready to confront in reality... Premier's new media art prize 2010: http://www.qagoma.qld.gov.au/exhibitions/past/2010/premier_of_queenslands_national_new_media_art_award_2010/chris_howlett

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Between 1984 and 1997, six cases of urothelial cancer and 14 cases of renal cell cancer occurred in a group of 500 underground mining workers in the copper-mining industry of the former German Democratic Republic, with high exposures to explosives containing technical dinitrotoluene. Exposure durations ranged from 7 to 37 years, and latency periods ranged from 21 to 46 years. The incidences of both urothelial and renal cell tumors in this group were much higher than anticipated on the basis of the cancer registers of the German Democratic Republic by factors of 4.5 and 14.3, respectively. The cancer cases and a representative group of 183 formerly dinitrotoluene- exposed miners of this local industry were interviewed for their working history and grouped into four exposure categories. This categorization of the 14 renal cell tumor cases revealed no dose-dependency concerning explosives in any of the four exposure categories and was similar to that of the representative group of employees, whereas the urothelial tumor cases were predominantly confined to the high-exposure categories. Furthermore, all identified tumor patients were genotyped by polymerase chain reaction, using lymphocyte DNA, regarding their genetic status of the polymorphic xenobiotic metabolizing enzymes, including the N-acetyltransferase 2 and the glutathione-S-transferases M1 and T1. This genotyping revealed remarkable distributions only for the urothelial tumor cases, who were exclusively identified as 'slow acetylators.' This points to the possibility of human carcinogenicity of dinitrotoluene, with regard to the urothelium as the target tissue.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Technical dinitrotoluene (DNT) is a mixture of 2,4- and 2,6-DNT. In humans, industrial or environmental exposure can occur orally, by inhalation, or by skin contact. The classification of DNT as an 'animal carcinogen' is based on the formation of malignant tumors in kidneys, liver, and mammary glands of rats and mice. Clear signs of toxic nephropathy were found in rats dosed with DNT, and the concept was derived of an interrelation between renal toxicity and carcinogenicity. Recent data point to the carcinogenicity of DNT on the urinary tract of exposed humans. Between 1984 and 1997, 6 cases of urothelial cancer and 14 cases of renal cell cancer were diagnosed in a group of 500 underground mining workers in the copper mining industry of the former GDR and having high exposures to explosives containing technical DNT. The incidences of both urothelial and renal cell tumors in this group were 4.5 and 14.3 times higher, respectively, than anticipated on the basis of the cancer registers of the GDR. The genotyping of all identified tumor patients for the polymorphic enzymes NAT2, GSTM1, and GSTT1 identified the urothelial tumor cases as exclusively 'slow acetylates'. A group of 161 miners highly exposed to DNT was investigated for signs of subclinical renal damage. The exposures were categorized semi-quantitatively into 'low', 'medium', 'high', and 'very high'. A straight dose-dependence of the excretion of urinary biomarker proteins with the ranking of exposure was seen. Biomarker excretion (alpha1-microglobulin, glutathione S-transferases alpha and pi) indicated that DNT-induced damage was directed toward the tubular system. New data on DNT-exposed humans appear consistent with the concept of cancer initiation by DNT isomers and the subsequent promotion of renal carcinogenesis by selective damage to the proximal tubule. The differential pathways of metabolic activation of DNT appear to apply to the proximal tubule of the kidney and to the urothelium of the renal pelvis and lower urinary tract as target tissues of carcinogenicity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A cohort of 161 underground miners who had been highly exposed to dinitrotoluene (DNT) in the copper-mining industry of the former German Democratic Republic was reinvestigated for signs of subclinical renal damage. The study included a screening of urinary proteins excreted by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and quantitations of the specific urinary proteins α 1-microglobulin and glutathione-S-transferase α (GST α) as biomarkers for damage of the proximal tubule and glutathione-S-transferase π (GST π) for damage of the distal tubule. The exposures were categorized semiquantitatively (low, medium, high, and very high), according to the type and duration of professional contact with DNT. A straight dose-dependence of pathological protein excretion patterns with the semiquantitative ranking of DNT exposure was seen. Most of the previously reported cancer cases of the urinary tract, especially those in the higher exposed groups, were confined to pathological urinary protein excretion patterns. The damage from DNT was directed toward the tubular system. In many cases, the appearance of Tamm-Horsfall protein, a 105-kD protein marker, was noted. Data on the biomarkers α 1-microglobulin, GST α, and GST π consistently demonstrated a dose-dependent increase in tubular damage, which confirmed the results of screening by SDS-PAGE and clearly indicated a nephrotoxic effect of DNT under the given conditions of exposure. Within the cluster of cancer patients observed among the DNT-exposed workers, only in exceptional cases were normal biomarker excretions found.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Text is the main method of communicating information in the digital age. Messages, blogs, news articles, reviews, and opinionated information abounds on the Internet. People commonly purchase products online and post their opinions about purchased items. This feedback is displayed publicly to assist others with their purchasing decisions, creating the need for a mechanism with which to extract and summarize useful information for enhancing the decision-making process. Our contribution is to improve the accuracy of extraction by combining different techniques from three major areas, named Data Mining, Natural Language Processing techniques and Ontologies. The proposed framework sequentially mines product’s aspects and users’ opinions, groups representative aspects by similarity, and generates an output summary. This paper focuses on the task of extracting product aspects and users’ opinions by extracting all possible aspects and opinions from reviews using natural language, ontology, and frequent “tag” sets. The proposed framework, when compared with an existing baseline model, yielded promising results.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper addresses the regulatory issues arising in developing a new regulatory model for the New South Wales Coal Industry. As such, it identifies the relevant literature on this subject, the options available for reform, and the experience of Australian and key international bodies responsible for the development of regulatory standards in this area. In particular it: Identifies the main shortcomings in the existing regulatory approach; Identifies the potential roles/main strengths and weaknesses of different types of standards (eg specification, performance, process and systems-based rules) and potential “best practice’ combinations of standards; Examines the appropriateness of the current regulatory regime whereby the general OHS legislation (including the general duty provisions) applies to mining in addition to the large body of regulation which is specific to mining; Identifies the importance of, and possible means of addressing, issues of worker participation within the coal mining industry; Draws on the literature on what motivates companies and individuals for the purpose of recommending key provisions for inclusion in new legislation to provide appropriate personal and organisational incentives; Draws on the literature on major hazards facilities to suggest the appropriate roles for OHS management systems and safety reports or comparable approaches (eg mine safety management plans); Draws on the United Kingdom (UK) and United States of America (USA) experience of coal mine safety and its regulation for comparative purposes, and for insights as to what sort of regulation most effectively reduces work related injury and disease in coal mining; Examines the relevant roles of International Labour Organisation (ILO) Conventions; Examines the extent to which different regulatory regimes would be appropriate to open cut and underground coal mining; and Examines options for reform. This paper is focussed specifically on the issues identified above.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This research treated the response of underground transportation tunnels to surface blast loads using advanced computer simulation techniques. The influences of important parameters, such as tunnel material, geometrical configuration of segments and surrounding soil were investigated. The findings of this research offer significant new information on the blast performance of underground tunnels and will contribute towards future civil engineering applications.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In 1996, Emma Baulch went to live in Bali to do research on youth culture. Her chats with young people led her to an enormously popular regular outdoor show dominated by local reggae, punk, and death metal bands. In this rich ethnography, she takes readers inside each scene: hanging out in the death metal scene among unemployed university graduates clad in black T-shirts and ragged jeans; in the punk scene among young men sporting mohawks, leather jackets, and hefty jackboots; and among the remnants of the local reggae scene in Kuta Beach, the island’s most renowned tourist area. Baulch tracks how each music scene arrived and grew in Bali, looking at such influences as the global extreme metal underground, MTV Asia, and the internationalization of Indonesia’s music industry. Making Scenes is an exploration of the subtle politics of identity that took place within and among these scenes throughout the course of the 1990s. Participants in the different scenes often explained their interest in death metal, punk, or reggae in relation to broader ideas about what it meant to be Balinese, which reflected views about Bali’s tourism industry and the cultural dominance of Jakarta, Indonesia’s capital and largest city. Through dance, dress, claims to public spaces, and onstage performances, participants and enthusiasts reworked “Balinese-ness” by synthesizing global media, ideas of national belonging, and local identity politics. Making Scenes chronicles the creation of subcultures at a historical moment when media globalization and the gradual demise of the authoritarian Suharto regime coincided with revitalized, essentialist formulations of the Balinese self.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Recent growth and expansion of the fly-in/fly-out (FIFO) model of mining in remote rural Australia has led to concerns about the health and well-being of those employed by the mines and those in the small rural communities where they are based. A particular concern has been the potential disruption to sexual norms in mining towns and increases in sexually transmitted infections (STIs) and HIV.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Critical stage in open-pit mining is to determine the optimal extraction sequence of blocks, which has significant impacts on mining profitability. In this paper, a more comprehensive block sequencing optimisation model is developed for the open-pit mines. In the model, material characteristics of blocks, grade control, excavator and block sequencing are investigated and integrated to maximise the short-term benefit of mining. Several case studies are modeled and solved by CPLEX MIP and CP engines. Numerical investigations are presented to illustrate and validate the proposed methodology.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

One of the Department of Defense's most pressing environmental problems is the efficient detection and identification of unexploded ordnance (UXO). In regions of highly magnetic soils, magnetic and electromagnetic sensors often detect anomalies that are of geologic origin, adding significantly to remediation costs. In order to develop predictive models for magnetic susceptibility, it is crucial to understand modes of formation and the spatial distribution of different iron oxides. Most rock types contain iron and their magnetic susceptibility is determined by the amount and form of iron oxides present. When rocks weather, the amount and form of the oxides change, producing concomitant changes in magnetic susceptibility. The type of iron oxide found in the weathered rock or regolith is a function of the duration and intensity of weathering, as well as the original content of iron in the parent material. The rate of weathering is controlled by rainfall and temperature; thus knowing the climate zone, the amount of iron in the lithology and the age of the surface will help predict the amount and forms of iron oxide. We have compiled analyses of the types, amounts, and magnetic properties of iron oxides from soils over a wide climate range, from semi arid grasslands, to temperate regions, and tropical forests. We find there is a predictable range of iron oxide type and magnetic susceptibility according to the climate zone, the age of the soil and the amount of iron in the unweathered regolith.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Strain-based failure criteria have several advantages over stress-based failure criteria: they can account for elastic and inelastic strains, they utilise direct, observables effects instead of inferred effects (strain gauges vs. stress estimates), and model complete stress-strain curves including pre-peak, non-linear elasticity and post-peak strain weakening. In this study, a strain-based failure criterion derived from thermodynamic first principles utilising the concepts of continuum damage mechanics is presented. Furthermore, implementation of this failure criterion into a finite-element simulation is demonstrated and applied to the stability of underground mining coal pillars. In numerical studies, pillar strength is usually expressed in terms of critical stresses or stress-based failure criteria where scaling with pillar width and height is common. Previous publications have employed the finite-element method for pillar stability analysis using stress-based failure criterion such as Mohr-Coulomb and Hoek-Brown or stress-based scalar damage models. A novel constitutive material model, which takes into consideration anisotropy as well as elastic strain and damage as state variables has been developed and is presented in this paper. The damage threshold and its evolution are strain-controlled, and coupling of the state variables is achieved through the damage-induced degradation of the elasticity tensor. This material model is implemented into the finite-element software ABAQUS and can be applied to 3D problems. Initial results show that this new material model is capable of describing the non-linear behaviour of geomaterials commonly observed before peak strength is reached as well as post-peak strain softening. Furthermore, it is demonstrated that the model can account for directional dependency of failure behaviour (i.e. anisotropy) and has the potential to be expanded to environmental controls like temperature or moisture.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The primary purpose of this paper is to overview a selection of advanced water treatment technology systems that are suited for application in towns and settlements in remote and very remote regions of Australia and vulnerable and lagging rural regions in Sri Lanka. This recognises that sanitation and water treatment are inextricably linked and both are needed to reduce risks to environment and population health from contaminated water sources. For both Australia and Sri Lanka only a small fraction of the settlements in rural and remote regions are connected to water treatment facilities and town water supplies. In Australia’s remote/very remote regions raw water is drawn from underground sources and rainwater capture. Most settlements in rural Sri Lanka rely on rivers, reservoirs, wells, springs or carted water. Furthermore, Sri Lanka has more than 25,000 hand pumped tube wells which saved the communities during recent droughts. Decentralised water supply systems offer the opportunity to provide safe drinking water to these remote/very remote and rural regions where centralised systems are not feasible due to socio-cultural, economic, political, technological reasons. These systems reduce health risks from contaminated water supplies. In remote areas centralized systems fail due to low population density and less affordability. Globally, a new generation of advanced water treatment technologies are positioned to make a major impact on the provision of safe potable water in remote/very remote regions in Australia and rural regions in Sri Lanka. Some of these systems were developed for higher income countries. However, with careful selection and further research they can be tailored to match local socio-economic conditions and technical capacity. As such, they can equally be used to provide decentralised water supply in communities in developed and developing countries such as Australia and Sri Lanka.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Draglines are used extensively for overburden stripping in Australian open cut coal mines. This paper outlines the design of a computer control system to implement an automated swing cycle on a production dragline. Subsystems and sensors have been developed to satisfy the constraints imposed by the task, the harsh operating environment and the mine's production requirements.