In this study, Computational Fluid Dynamics Modeling (CFD) was applied to model a room-and-pillar mining working area to investigate the airflow patterns for dust control. Room-and-pillar mining is a conventional underground mining technique used for the extraction of coal by cutting excavations called "rooms" using a continuous mining machine and leaving the remaining coal as "pillars" for supporting the coal seam. The FLUENT software was used to analyze the airflow in the mine whose structure was designed and meshed in GAMBIT. The analysis was carried out in four different stages. First, airflow patterns were studied in the roadway without any equipment. Next, a line curtain, which extends along the height of the coal seam, was simulated in the roadway to direct the flow of air towards the active mining face. In the third stage, a continuous miner was inserted between the mining face and the end of the line curtain. Three and six meters deep box and slab cuts were simulated and the airflow patterns were investigated. In the final stage, a wet scrubber was simulated as an integral part of the continuous miner and the effect of the scrubber on the airflow in the box and slab cuts were studied. Dead zones (areas with limited airflow) and recirculation areas were observed using velocity distribution contours. A parametric study was conducted to evaluate the effects of distance of the curtain from the pillar rib (Dcr), scrubber pressure (Psc) and height of the coal seam (Ho). The data were plotted as functions of selected dimensionless variables. It was seen that wet scrubber increased the air in the LOXC (Last open cross cut) by 7.6% and was also proved that extension of line curtain along with the cut. The results of these studies are being used to develop guidelines for dust control in the face area.

Ces travaux de thèse concernent la conception d’un dispositif de restitution sonore léger en salle usuelle, permettant la diffusion de signaux binauraux. La priorité du travail est la précision dans la reproduction du niveau et du timbre, avant la spatialisation du son. Afin d’assurer la compatibilité avec les signaux binauraux existants et pour proposer un système à faible nombre de canaux, la technologie transaurale est prise comme point de départ. Pour limiter la coloration introduite par la salle d’écoute, particulièrement gênante, il est proposé de placer les sources du système à proximité de l’auditeur afin de maximiser le rapport champ direct sur champ diffus. Ce placement inhabituel a plusieurs effets, parmi lesquels quatre ont été étudiés séparément : l’influence des filtres transauraux sur les sources électro-acoustiques, les variations inter-individuelles de morphologies, l’effet de salle et le placement de l’auditeur. Des tests d’écoute ont été réalisés pour une sélection de configurations, et les résultats ont permis d’implémenter des indicateurs objectifs représentatifs des réponses des auditeurs. La synthèse de ces indicateurs a permis de proposer trois configurations considérées comme optimales, et dont la combinaison pourrait être envisagée. / This work deals with the design of a 3D sound system involving a few number of loudspeaker and able to work inside any usual room, for reproducing binaural sounds. This system focuses on an accurate reproduction of perceived level and timbre, even before the sound spatialization. To ensure compatibility with binaural recordings and to achieve a system with a low number of loudspeakers, this work started from a transaural system. To avoid tone coloration induced by the listening room, the sound sources are placed close to the listener, thus maximizing the energy ratio between direct and diffuse fields. This has consequences on other aspects, four of which are considered separately: inter-individual morphological variations, demands on the electro-acoustic sources, room effect and misalignment of the listener. Some configurations have been evaluated in listening tests, and objective indicators are deduced from these results. The generalization allows to propose three configurations considered as optimal, and which might be combined.

Este trabalho aborda a avaliação da percepção do conforto térmico em uma sala de controle, tendo como objetivo identificar quais os fatores que influenciam na sensação térmica dos operadores e se esta sensação difere estatisticamente entre os quatro turnos de trabalho. Foram medidas as variáveis ambientais (temperatura do ar, temperatura média radiante, umidade do ar e velocidade do ar), levantadas as variáveis pessoais (vestimenta e taxa metabólica) e aplicados questionários para coletar as sensações térmicas dos operadores a cada 1 hora. A taxa metabólica foi estimada em função da atividade, conforme os valores tabelados pela ASHRAE (2001), mas tal estimação pode apresentar imprecisões devido às diferenças individuais e às condições fisiológicas do ser humano, que são influenciadas pelo ritmo circadiano. O isolamento térmico médio das vestimentas foi de 0,5 a 0,8clo, sendo que os valores mais elevados ocorreram no turno da madrugada. Devido ao controle ambiental térmico da sala, a temperatura média do ar ao longo do dia permaneceu dentro de limites muito próximos. A sensação térmica predominantemente relatada pelos operadores, foi neutra, isto é, nem frio nem calor. Apenas em alguns períodos, principalmente no turno da madrugada, foi relatado desconforto devido ao frio. Não houve diferença significativa entre os resultados de conforto para os diferentes turnos de trabalho, mas o assunto merece estudos mais aprofundados. Os valores de PMV apresentaram baixa correlação estatística com as sensações relatadas pelos operadores, provavelmente em função dos valores da taxa metabólica e do isolamento térmico das vestimentas serem tabelados e não se ajustarem ao ambiente de trabalho. Devido a esta baixa correlação, a Anova não paramétrica de Kruskal-Wallis foi utilizada permitindo identificar que a temperatura do ar, a temperatura média radiante, a umidade do ar e a vestimenta utilizada influenciaram a sensação térmica dos operadores. Tendo em vista que o PMV não predisse a sensação térmica dos usuários, conclui-se que ele não é um bom parâmetro para uso em projetos de ambiente construído. / This present work approachs the evaluation of thermal comfort perception inside a control room, having the specific goal to identify which factors are important to the worker’s thermal sensation and if this sensation differs statistically among the four shifts work. Each environmental parameter (air temperature, mean radiant temperature, relative humidity and air velocity) were measured. The personal variables (clothing insulation and metabolic rate) were evaluated and questionnaires were applied to collect worker’s thermal sensation each hour. The metabolic rate was estimated through the activity, according to the ASHRAE table (2001). This estimative might not be precise due to individual differences and to physiological conditions of the human being, which are influenced by the circadian rhythm. The clothing insulation was 0,5 to 0,8 clo, and the highest values occurred in the early hours of the morning. Owing to the environmental control of the room, the mean air temperature through the day did not have significant changes. The thermal sensation predominantly reported by the workers was neutral, that is, neither cold nor warm. Only in a few periods, especially in the early hours of the morning, was related discomfort because of the cold. There is not a significative difference among the comfort results for the different shifts work, but the topic deserves deeper studies. The PMV values no small statistic correlation with the sensations related by the workers, probably due to the values of the metabolic rate and to the clothing insulation be tabled and were not to adjustable to the work environment. As a result of this weak correlation, the Kruskal-Wallis non parametric Anova was used to identify that air temperature, mean radiant temperature, air relative humidity and clothing insulation influenced the worker’s thermal sensation. Considering that the PMV did not predict the worker’s thermal sensation, the data suggest that the PMV is not a good parameter to be used in projects of buildings.

A incorporação da informática nas atividades corriqueiras da execução de desenhos técnicos provocou uma verdadeira revolução nas práticas de ensino destes conteúdos. As pranchetas foram substituídas por computadores, alterando a prática do ensino e o modo de aprender, criando a necessidade de projetar um novo tipo de sala de aula, voltada a atender às novas exigências. Esta pesquisa diagnostica os problemas e identifica as diretrizes que devem nortear este projeto. Para tanto, foram entrevistados professores da área de Desenho Técnico, fabricante de móveis, técnicos em condicionamento ambiental e aplicados questionários aos estudantes deste conteúdo na Universidade Federal do Rio Grande do Sul. O resultado desta pesquisa é um conjunto de diretrizes que se apresenta para auxiliar aos projetistas, fornecendo uma orientação sobre as principais variáveis envolvidas. / The integration of informatics in simple activities of technical drawing performance has led to a real revolution in the teaching practices of these contents. The drawing boards have been substituted by computers, making a change in teaching practice and in the way of learning, giving rise to the necessity of projecting a new kind of classroom aiming to fulfill the new demands. This research recognizes the problems and identifies the guidelines that lead the way to this project. In order to do that interviews with Technical Drawing professors, furniture manufacturers and environmental conditioning technicians were conducted, as well as the use of questionnaires with students of this subject at Federal University of Rio Grande do Sul. The result of this research is a set of guidelines that is presented to help designers, indicating to them trends concerning the main variables involved.

O objetivo principal deste trabalho é apresentar um protocolo para avaliação de compatibilidade entre a gestão de procedimentos e a complexidade do sistema sócio-técnico em que esses são aplicados. Tal protocolo consiste das seguintes etapas: (a) delimitação do sistema sócio-técnico a ser estudado; (b) caracterização do sistema sócio-técnico; (c) caracterização da complexidade do sistema em estudo; (d) aplicação de dois tipos de questionários aos membros do sistema investigado; um deles destinado a avaliar a percepção em relação a um conjunto de princípios acerca de como os procedimentos deveriam ser gerenciados em um sistema complexo; outro destinado a avaliar a percepção acerca da extensão pela qual os princípios realmente são usados; (e) uma reunião de retorno dos resultados da avaliação aos membros do sistema sócio-técnico; (f) elaboração de recomendações para melhorar a gestão de procedimentos. A aplicação do protocolo é ilustrada por meio de um estudo de caso na sala de controle de uma refinaria de petróleo. / The main objective of this dissertation is to introduce a protocol for assessing the compatibility between the procedures management and the complexity of a socio-technical system in which these are applied to. This protocol consist of the following steps: (a) definition of the socio-technical system to be studied, (b) characterization of socio-technical system, (c) characterizing of the system under study complexity, (d) applying two questionnaires of different kinds to the members of the system investigated, one of them to assess the perceptions in relation to a set of principles about how the procedures should be managed in a complex system, and another designed to assess the perception of the extent to which the principles are actually used, (e) carrying out a return meeting of the assessment results to the members of socio-technical system, (f) developing of recommendations to improve management procedures. The application of the protocol is illustrated through a case study in an oil refinery control room.

A presente pesquisa teve por objetivo compreender de que forma o Atendimento Educacional Especializado/Sala de Integração e Recursos Visual colabora no processo de escolarização das pessoas com deficiência visual. A análise privilegiou os possíveis elos existentes entre o atendimento educacional especializado com o ensino regular. As questões que instigaram a autoria do presente estudo foram as seguintes: como realizar tarefas para alunos com deficiência visual num currículo que valora a escrita em detrimento de outras formas de aprendizagens? Como vem sendo realizado o trabalho da Sala de Integração e Recursos – SIR Visual, no contexto da Rede Municipal de Ensino de Porto Alegre? A pesquisa empírica ocorreu em uma escola da Rede Municipal de Ensino de Porto Alegre, a qual tem priorizado às políticas de inclusão escolar referentes ao Atendimento Educacional Especializado, considerando a forma que este serviço foi sendo realizado ao longo dos anos, identificando aspectos a partir das reflexões do pensamento sistêmico de Gregory Bateson e da teoria histórico-cultural de Lev Vigotsky. A pesquisa optou pela abordagem qualitativa, utilizando os seguintes instrumentos metodológicos: entrevista semiestruturada, observação participante e o diário de campo. A análise dos dados constatou a importância do atendimento educacional especializado, mais especificamente a Sala de Integração e Recursos – Visual no processo de inclusão escolar dos alunos com deficiência visual, orientando, supervisionando e possibilitando um trabalho adequado às necessidades de pais, alunos e, principalmente, ao professor da sala de aula regular. Também ficou evidenciada a dificuldade de interlocução entre os professores coordenadores da Sala de Integração e Recursos com os professores da sala de aula regular. / This research aimed to understand how the Educational Service Specialist / Integration Room and Visual Resources collaborates in the schooling process of visually impaired people. The analysis favored potential existing links between specialized education with mainstream education. The issues that prompted the authors of this study were: how to perform tasks for students with visual impairment in a curriculum that values the writing over other forms of learning? As has been done the work of the Integration and Resource Room - SIR Visual, within the Municipal School of Porto Alegre? The empirical research took place in a school of the Municipal System of Porto Alegre Education, which has prioritized the school inclusion policies for the Educational Service Specialist, considering the way that this service was being held over the years, identifying aspects from reflections of systems thinking of Gregory Bateson and cultural-historical theory of Lev Vygotsky. The research opted for a qualitative approach using the following methodological tools: semi-structured interviews, participant observation and the field diary. Data analysis found the importance of specialized educational services, specifically the Integration and Resource Room - Visual in the process of school inclusion of students with visual impairment, guiding, supervising and providing an adequate job to the needs of parents, students, and especially , the teacher of the regular classroom. It was also demonstrated the difficulty of communication between the coordinating teachers of the Integration and Resource Room with teachers from the regular classroom.

O método de lavra câmaras e pilares é muito utilizado em minas de carvão subterrâneo, principalmente nos estados de Santa Catarina e Paraná, onde todas as minas subterrâneas utilizam este método. Vale ressaltar, porém, que o método apresenta recuperações de lavra abaixo de 50%, dependendo do tamanho dos pilares, e a produtividade é altamente dependente de uma boa concatenação das operações unitárias. Entre os aspectos relacionados à eficiência produtiva, a distância de transporte é um item preponderante no desempenho do sistema. Devido à profundidade da lavra, há um aumento do tamanho dos pilares de sustentação da mina, e assim, surgem problemas relacionados ao incremento no tempo de ciclo de transporte dos equipamentos. O aumento da distância de transporte entre uma frente de lavra com material desmontado e o alimentador/britador primário, reduz o resultado da produção de um conjunto de equipamentos. Em mineração a céu aberto, este tipo de problema é resolvido com o aumento da frota de transporte, todavia, na mineração de carvão subterrânea, não é possível aumentar de forma irrestrita a quantia de máquinas em subsolo, pois impactaria diretamente na necessidade de incremento da vazão de ar, assim como, limitação de espaço para o tráfego de equipamentos. A aproximação da distância do ponto de descarga para um local adjacente às frentes de serviço é uma alternativa para solucionar a necessidade de incremento da frota de produção. No entanto, o ponto de mudança deve ser avaliado de forma consistente para determinar o momento mais adequado para que essa reaproximação proporcione um resultado ótimo. Este estudo buscou compreender esta etapa necessária ao processo produtivo, utilizando técnicas de regressão para analisar o impacto da distância de transporte na capacidade produtiva. O problema foi modelado e foram propostas alternativas que forneçam um sequenciamento de lavra capaz de amenizar os problemas decorrentes do aumento da distância de transporte das frentes de lavra aos respectivos pontos de descarga. Os resultados demonstraram que a distância de transporte tem influência direta na produção, mas não somente a distância máxima, mas também, uma distância mínima que deve ser respeitada para obter maior produtividade quando se tem a associação de equipamentos de produção. É possível concluir com este estudo que a distância de transporte tem impacto relevante e deve ser considerada, não tão somente no sequenciamento, mas também no dimensionamento da frota e consequente capacidade produtiva. / The room and pillar mining method is widely used in underground coal mines. Santa Catarina and Paraná where all underground mines use this method. Indeed, the method has mining recoveries below 50% and the productivity is highly dependent on a good concatenation of unit operations. Among the aspects related to production efficiency, the transport distance is an important item on system performance. Due to the depth of the mine, there is an increment in the size of the underground supporting pillars, and consequently, problems related to the increase in equipment cycle times. The increase of the transportation distance between mining faces and the primary crusher reduces the result of a set of production equipment. In open pit mining, this problem is solved by increasing the haulage fleet, however, in the underground coal mining, the number of machines cannot be increased indefinitely because it would impact directly on the need of increased air flow. Therefore, the approximation of the distance from the discharge point to an adjacent location from the mining faces is an alternative to address the need of increased production fleet. However, the relocation point must be evaluated consistently to determine the most appropriate time to get the most from this approach. The goal of the study was to understand this imperative step for the production process, using regression techniques to analyze the impact of transport distance in productive capacity. Based on the experimental design used in this study, alternative proposals provide a mining sequence able to mitigate the problems from increasing transportation distance from mining faces to their discharge points. The results show that the transport distance has directly influence on the production, and it is not limited to the maximum distance. Likewise, a minimum distance must be respected for higher productivity when you have the combination of production equipment. So, it is possible to conclude that the transport distance has a significant impact and must be considered not only during the sequencing, but also when determining the fleet size and consequent production capacity.

This thesis studies airflow patterns in the face area of a typical room-and-pillar mining area, using Computational Fluid Dynamics (CFD) modeling. This research is designed to develop a scientific understanding of airflow distribution in room-and-pillar mining areas that is fundamental to developing engineering controls. The overall goal of the study is to develop improved engineering controls to minimize dust exposure of mine workers in the face area. Dust exposure can be a health hazard in underground coal mining industry based on historical data of coal workers' pneumoconiosis among underground mine workers. Current regulatory dust exposure standards of 1.5 mg/m3, averaged over an 8-hour period, have been recently revised with approval of new MSHA standards in April of 2014. Mining companies are currently seeking new technologies in order to comply with the new dust standards. Since mining geometries are complex and do not lend themselves to closed-form analytical solutions, CFD numerical modeling approach was used to develop an understanding of airflow distribution in the face areas. Since previous studies had focused on some cuts in mining heights of less than 2.4 m (8-ft), this study was performed for high mining areas of 4.2 m (14-ft). Such mining heights are very common in longwall mine development areas, particularly in the State of Illinois. The primary goal was to identify major differences in airflow between the two mining heights and how they affect development of engineering controls for minimizing dust exposure. Simulations were done using ANSYS software such as DesignModeler for modeling and meshing and FLUENT for calculations. Recirculation (RC) and low air velocity (LAV) zones were located for straight deep cut, straight deepest cut, cross-cut right, cross-cut right mine through, left turn cross-cut, and left turn cross-cut mine through for low mining height (LMH) and high mining height (HMH) with varying air quantity at the end of the line curtain (ELC). Air at the ELC was adjusted to achieve a ratio of 0.85, 1.00 and 1.15 over the wet scrubber fan (WSF) discharge capacity. Results show that the air velocity in HMH case is much lower than for the LMH. In addition, the location of RC and LAV zones differ based on mining height and air quantity at the ELC. Furthermore, lower air quantity at the ELC causes the air exhausted by the WSF to recirculate back to the face area in order to satisfy the WSF requirement. Recommendations to deal with these differences are formulated.

This thesis has developed wetting characteristics of coal dust from Herrin coal seam in Illinois for improved respirable coal and quartz dust (< 10µm) control. Wetting characteristics were assessed by a wettability technique called Fixed Time Wettability (FTW) method which simulates the actual underground wetting environment. Immediate roof and immediate floor materials bulk samples were found to be 100% wettable by water alone, whereas coal seam samples were 55-90% wettable. Two variables: contact time between water droplets and dust particles and, the temperature of the water were found to affect the degree of wettability. FTW was carried out at as a function of water temperature (7.2oC to 40.5oC) and contact time (10 to 25 seconds) which increased wettability 2-18% and 8-32%, respectively. In addition, the wetted and un-wetted samples collected from wettability experiments were subjected to Scanning Electron Microscopy (SEM) and particle size distribution analyses. It was found that particles are irregular in shape in both wetted and un-wetted fractions and some agglomeration of fine particles was observed in a few un-wetted fraction samples. The concept of increased contact time was incorporated in engineering controls by increasing the wet scrubber filter screen inclination (which is a function of the screen surface area). The filter screen inclination was minimizing the pressure drop across it using Computational Fluid Dynamics (CFD) analysis. It was found that 60 degree (with respect to the vertical) would provide minimal pressure drop and should be considered for implementation. Additional research should be conducted on assessing selective wetting of different particle sizes of coal and quartz in airborne dust, developing data on wettability as a function of particle size and implementing the developed concepts such as contact time and temperature in the field for improved dust control.

Submitted by Diogo Misoguti (diogo.misoguti@gmail.com) on 2016-06-21T12:24:52Z No. of bitstreams: 1 estevao-marcos-armada-firmino.pdf: 3789021 bytes, checksum: e10ece277fa9c93e0f2ebf7e95a77c27 (MD5) / Approved for entry into archive by Diogo Misoguti (diogo.misoguti@gmail.com) on 2016-06-21T12:25:37Z (GMT) No. of bitstreams: 1 estevao-marcos-armada-firmino.pdf: 3789021 bytes, checksum: e10ece277fa9c93e0f2ebf7e95a77c27 (MD5) / Made available in DSpace on 2016-06-21T12:25:37Z (GMT). No. of bitstreams: 1 estevao-marcos-armada-firmino.pdf: 3789021 bytes, checksum: e10ece277fa9c93e0f2ebf7e95a77c27 (MD5) Previous issue date: 2015-09 / O objetivo principal desta pesquisa é investigar os eventos e práticas de letramento que ocorreram durante as aulas de Sala de Leitura, com alunos de uma turma de 4° ano do ensino fundamental I, da Rede Municipal de Ensino de São Paulo. Num primeiro momento, procuramos apresentar o referencial teórico da pesquisa que foi construído com base em um quadro epistemológico transdisciplinar, que buscou efetivar o diálogo entre Estudos sobre Letramento, pesquisas sobre interação em sala de aula e autores do campo sociológico. Posteriormente, contextualizamos a Sala de Leitura e fizemos a análise de parte do trabalho prescrito para esse espaço, por meio do exame do Caderno Orientador ‘Leitura ao pé da Letra’, com fins de se compreender as escolhas didáticas do Professor Orientador de Sala de Leitura. Em seguida, descrevemos, analisamos e interpretamos algumas práticas de letramento ocorridas no contexto situado de pesquisa, a partir de um mapeamento da dinâmica discursiva das aulas com o 4° ano, que evidenciou a ocorrência de eventos de letramento criados pelo Professor Orientador de Leitura e eventos criados pelos alunos. A pesquisa, de cunho qualitativo e interpretativa, empregou a abordagem etnográfica no acompanhamento das aulas transcorridas durante o ano letivo, e dessa forma, foram utilizados um diário de pesquisa, fotografias e gravações em áudio das aulas. A análise desses dados foi feita através de mapas de eventos das aulas e seleção de episódios ocorridos durante as interações nas aulas. Nossos resultados indicam que os eventos de letramento observáveis nesta Sala de Leitura estavam relacionados majoritariamente a práticas de letramento de leitura literária escolarizada, adotadas pelo Professor e práticas de letramento de leituras voluntárias empregadas por alguns alunos e alunas do 4° ano. Esses resultados revelam a necessidade de uma compreensão ampliada das práticas de leitura voluntárias dos alunos que se engajam em leituras de não ficção e a necessidade de discussão referente a hibridização de práticas escolares com as não-escolares na Sala de Leitura. / The main objective of this research is to investigate the events and literacy practices that occurred during the Reading Room classes with students from a group of 4th year of elementary school, from a public school in the city of São Paulo. At first, we presented the theoretical background of the research that was based on a transdisciplinary epistemological framework that sought to accomplish the dialogue among studies on literacy, researches on interaction in the classroom and authors of the sociological field. Later, we put the Reading Room into context and analyzed of the work prescribed for that space, through the exam of Guiding Book 'Literal Reading', in order to understand the educational choices of the Reading Room’s supervisor. We then described, analyzed and interpreted some literacy practices that occurred in the research context, based on a mapping of the dynamics classes with the 4th grade students, which showed the occurrence of literacy events created by Reading Teacher Supervisor and events created by the students. This qualitative and interpretative research used the ethnographic approach in classes during the school year and thus a research journal, photographs and audio recordings of the classes were used. The analysis of data was performed through maps of events related to classes and selection of episodes occurring during the interaction in class. Our results indicate that literacy events observed in this Reading Room were mainly related to practices of literacy educated literary reading adopted by the teacher and literacy practices of voluntary readings by some 4th grade students. These results reveal the need for a broad understanding of voluntary reading practices of students who engage in non-fiction readings, as well as the need for a discussion on the hybridization of the school with the non-school practices in the Reading Room.