970 resultados para 650200 Mining and Extraction


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Temporal representation and reasoning plays an important role in Data Mining and Knowledge Discovery, particularly, in mining and recognizing patterns with rich temporal information. Based on a formal characterization of time-series and state-sequences, this paper presents the computational technique and algorithm for matching state-based temporal patterns. As a case study of real-life applications, zone-defense pattern recognition in basketball games is specially examined as an illustrating example. Experimental results demonstrate that it provides a formal and comprehensive temporal ontology for research and applications in video events detection.

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A method of injecting metallic elements into an electron-beam ion trap (EBIT) is described. The method is advantageous over the conventional coaxial and pulsed injection methods in two ways: (a) complicated switching of injection and extraction beams can be avoided when extracting beams of highly charged ions from the EBIT and (b) a beam of stable intensity can be achieved. This method may be applicable to any metallic elements or metallic compounds that have vapor pressures of similar to 0.1 Pa at a temperature lower than 1900 degrees C. We have employed this method for the extraction of highly charged ions of Bi, Er, Fe, and Ho. (c) 2006 American Institute of Physics.

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Five British former mining and smelting sites were investigated and found to have levels of total Sb of up to 700 mg kg(-1), indicating high levels of contamination which could be potentially harmful. However, this level of Sb was found to be biologically unavailable over a wide range of pH values, indicating that Sb is relatively unreactive and immobile in the surface layers of the soil, remaining where it is deposited rather than leaching into lower horizons and contaminating ground water. Sb, sparingly soluble in water, was unavailable to the bacterial biosensors tested. The bioluminescence responses were correlated to levels of co-contaminants such as arsenic and copper, rather than to Sb concentrations. This suggests that soil contamination by Sb due to mining and smelting operations is not a severe risk to the environment or human health provided that it is present as immobile species and contaminated sites are not used for purposes which increase the threat of exposure to identified receptors. Co-contaminants such as arsenic and copper are more bioavailable and may therefore be seen as a more significant risk.

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Earth pressure balanced (EPB) full face tunneling machines have experienced a remarkable increase in the number of applications throughout the world due to both mechanical developments and a more effective use of additives to condition the ground. Conditioning modifies the mechanical and hydraulic properties of a soil by making it suitable for the pressure control in the bulk chamber and extraction with the screw conveyor. The extraction system plays a fundamental role during the EPB operations particularly for a correct application of the face pressure. Despite the extensive use of the EPB technique, little knowledge exists concerning the understanding of the behavior of conditioned soil, particularly for noncohesive ground (sand and gravel). This paper presents and describes a prototype laboratory device, which simulates the extraction of the ground from a pressurized tank with a screw conveyor. The results of a preliminary test program carried out on a medium sized sand show that the prototype device is efficient in verifying the effects of foam for an optimal use in EPB conditioning. © 2007 ASCE.

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Milling is an important operation in many industries, such as mining and pharmaceutical. Although the comminution process during milling has been extensively studied, the material fragmentation mechanisms in a mill are still not well understood partly because of the lack of an understanding on the local stressing and dynamic information under operational conditions in mills. This paper presents a DEM simulation of particle dynamics and impact events in a centrifugal impact pin mill. The main focus is the statistical characteristics of the dominant stressing modes during the milling process. The frequency, velocity and force of the different impact events between particles and mill components, or between particles, are analysed. © 2013 AIP Publishing LLC.

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The last decade has witnessed an unprecedented growth in availability of data having spatio-temporal characteristics. Given the scale and richness of such data, finding spatio-temporal patterns that demonstrate significantly different behavior from their neighbors could be of interest for various application scenarios such as – weather modeling, analyzing spread of disease outbreaks, monitoring traffic congestions, and so on. In this paper, we propose an automated approach of exploring and discovering such anomalous patterns irrespective of the underlying domain from which the data is recovered. Our approach differs significantly from traditional methods of spatial outlier detection, and employs two phases – i) discovering homogeneous regions, and ii) evaluating these regions as anomalies based on their statistical difference from a generalized neighborhood. We evaluate the quality of our approach and distinguish it from existing techniques via an extensive experimental evaluation.

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The problem of detecting spatially-coherent groups of data that exhibit anomalous behavior has started to attract attention due to applications across areas such as epidemic analysis and weather forecasting. Earlier efforts from the data mining community have largely focused on finding outliers, individual data objects that display deviant behavior. Such point-based methods are not easy to extend to find groups of data that exhibit anomalous behavior. Scan Statistics are methods from the statistics community that have considered the problem of identifying regions where data objects exhibit a behavior that is atypical of the general dataset. The spatial scan statistic and methods that build upon it mostly adopt the framework of defining a character for regions (e.g., circular or elliptical) of objects and repeatedly sampling regions of such character followed by applying a statistical test for anomaly detection. In the past decade, there have been efforts from the statistics community to enhance efficiency of scan statstics as well as to enable discovery of arbitrarily shaped anomalous regions. On the other hand, the data mining community has started to look at determining anomalous regions that have behavior divergent from their neighborhood.In this chapter,we survey the space of techniques for detecting anomalous regions on spatial data from across the data mining and statistics communities while outlining connections to well-studied problems in clustering and image segmentation. We analyze the techniques systematically by categorizing them appropriately to provide a structured birds eye view of the work on anomalous region detection;we hope that this would encourage better cross-pollination of ideas across communities to help advance the frontier in anomaly detection.

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The past decade had witnessed an unprecedented growth in the amount of available digital content, and its volume is expected to continue to grow the next few years. Unstructured text data generated from web and enterprise sources form a large fraction of such content. Many of these contain large volumes of reusable data such as solutions to frequently occurring problems, and general know-how that may be reused in appropriate contexts. In this work, we address issues around leveraging unstructured text data from sources as diverse as the web and the enterprise within the Case-based Reasoning framework. Case-based Reasoning (CBR) provides a framework and methodology for systematic reuse of historical knowledge that is available in the form of problemsolution
pairs, in solving new problems. Here, we consider possibilities of enhancing Textual CBR systems under three main themes: procurement, maintenance and retrieval. We adapt and build upon the stateof-the-art techniques from data mining and natural language processing in addressing various challenges therein. Under procurement, we investigate the problem of extracting cases (i.e., problem-solution pairs) from data sources such as incident/experience
reports. We develop case-base maintenance methods specifically tuned to text targeted towards retaining solutions such that the utility of the filtered case base in solving new problems is maximized. Further, we address the problem of query suggestions for textual case-bases and show that exploiting the problem-solution partition can enhance retrieval effectiveness by prioritizing more useful query suggestions. Additionally, we illustrate interpretable clustering as a tool to drill-down to domain specific text collections (since CBR systems are usually very domain specific) and develop techniques for improved similarity assessment in social media sources such as microblogs. Through extensive empirical evaluations, we illustrate the improvements that we are able to
achieve over the state-of-the-art methods for the respective tasks.

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Mining and metallurgical industries are the most responsible for heavy metal contamination. These contaminants are often associated to poor management strategies and the lack of suitable containment areas. This is the case of one of the largest metal alloy producers in the São Francisco river basin, in Minas Gerais state, Brazil. During operation, the tailings of this activity have been accumulated in the surrounding area, leading to heavy metal contamination (Mn, Cu, Zn, Ni, Pb, Cd, Cr and As), much above the critical levels, which accumulate in the sediments of the nearby waterways, in the soils of the drainage area, and in the water column. In this work we are going to discuss both the contamination level and its extent in the Consciência river, a small tributary of the São Francisco river, the longest river entirely Brazilian, by analyzing the geochemistry and mineralogy of the accumulated sediments. It will be also discuss the reclamation strategies of this site and the impact on the environment.

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Este trabalho teve como principal objetivo estudar e modificar as propriedades funcionais das proteínas de soja de forma a otimizar e diversificar a sua aplicação industrial. Para tal, foram propostas e estudadas quatro estratégias: i) extração do isolado de proteínas de soja (IPS) a partir de diferentes matérias-primas, ii) adição de galactomananas (GM) com graus de ramificação e massas moleculares diferentes, iii) hidrólise enzimática controlada das proteínas de soja, iv) processamento por alta pressão hidrostática. O estudo e a interpretação da influência destas estratégias sobre as propriedades funcionais das proteínas de soja, nomeadamente, na capacidade gelificante e emulsionante, foram realizados recorrendo fundamentalmente a ensaios reológicos dinâmicos a baixas deformação, espectroscopia de infravermelho, electroforeses, calorimetria diferencial de varrimento e ensaios de microscopia confocal de varrimento laser. O estudo da extração e caracterização dos isolados de proteínas de soja obtidos a partir de diferentes matérias-primas permitiu concluir que as caraterísticas físico-químicas dos isolados são dependentes da origem da matéria-prima de extração e da severidade dos tratamentos industriais prévios à extração do isolado. Contudo, as propriedades viscoelásticas dos géis obtidos por aquecimento controlado não foram significativamente distintas embora tenha sido possível relacionar o grau de agregação com a diminuição da temperatura de gelificação e com o aumento inicial dos módulos viscoelásticos. As alterações sofridas pelos isolados de origem comercial mostraram ser irreversíveis resultando em géis menos rígidos e com maior caráter viscoso. A adição de galactomanana alterou significativamente o mecanismo de gelificação induzido termicamente das proteínas de soja, bem como as propriedades viscoelásticas dos géis e a microestrutura dos géis, demonstrando-se a ocorrência de separação de fases, em virtude da incompatibilidade termodinâmica entre os biopolímeros, resultando em géis mais rígidos e no decréscimo da temperatura de gelificação. A extensão destas alterações foi dependente da massa molecular, grau de ramificação e da razão IPS/GM. O efeito da hidrólise enzimática por ação da bromelina, nas propriedades gelificantes e emulsionantes das proteínas de soja, mostrou ser dependente do grau de hidrólise (GH). Valores de GH inferiores a 15 % melhoraram as propriedades gelificantes das proteínas de soja. Por outro lado, o aumento do GH teve um efeito negativo nas propriedades emulsionantes, o qual foi atenuado por adição da goma de alfarroba, com efeito positivo na gelificação das proteínas de soja. A concentração crítica limite de compatibilidade entre os hidrolisados de proteína de soja e a goma de alfarroba aumentou com o decréscimo do GH e da massa molecular do polissacacrídeo. O efeito da AP sobre as propriedades físico-químicas e funcionais dos IPS foi influenciado pela origem do isolado e pelas condições de tratamento. O processamento até 100 MPa desencadeou um aumento da atividade emulsionante e considerável melhoria da capacidade gelificante. Contudo, valores de pressão superiores promoveram a desnaturação das proteínas constituintes dos isolados, resultando no decréscimo da temperatura de gelificação e numa re-associação das subunidades proteicas, diminuindo a elasticidade dos géis finais. Os resultados sugeriram que as alterações nas proteínas de soja promovidas durante o tratamento por AP constituem um fator limitante para o desdobramento e re-associação durante o aquecimento térmico, necessários para a formação e fortalecimento de gel formado. O processamento por AP influenciou a estrutura secundária e a microestrutura das amostras. A presença de GA teve um papel baroprotetor. Assim, com este trabalho demonstrou-se que com as estratégias seguidas para manipulação das propriedades funcionais de proteínas de soja, nomeadamente através da adição de um polissacarídeo com propriedades estruturais controladas, da adequada combinação da adição de um polissacarídeo neutro com a hidrólise controlada das proteínas ou com tratamento por alta pressão, é possível a criação de novas funcionalidades, com utilidade no desenvolvimento de novas formulações alimentares, permitindo expandir a aplicação destas proteínas vegetais.

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Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo Automação e Electrónica Industrial

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Naturally occurring radioactive materials (NORM) under certain conditions can reach hazardous radiological levels contributing to an additional exposure dose to ionizing radiation. Most environmental concerns are associated with uranium mining and milling sites, but the same concerns should be addressed to natural near surface occurrences of uranium as well as man-made sources such as technologically enhanced naturally occurring radioactive materials (TENORM) resulting from phosphates industry, ceramic industry and energy production activities, in particular from coal-fired power plants which is one of the major sources of increased exposure to man from enhanced naturally occurring materials. This work describes the methodology developed to assess the environmental radiation by in situ gamma spectrometry in the vicinity of a Portuguese coal fired power plant. The current investigation is part of a research project that is undergoing in the vicinity of Sines Coal-Fired Power Plant (south of Portugal) until the end of 2013.