973 resultados para Carbonaceous aerosols
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The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierre Auger Observatory since the start of regular operations in 2004, and includes a discussion of the impact of these measurements oil air shower reconstructions. Between 10(18) and 10(20) eV, the systematic Uncertainties due to all atmospheric effects increase from 4% to 8% in measurements of shower energy, and 4 g cm(-2) to 8 g cm(-2) in measurements of the shower maximum. (C) 2010 Elsevier B.V. All rights reserved.
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We present the first results of a study investigating the processes that control concentrations and sources of Pb and particulate matter in the atmosphere of Sao Paulo City Brazil Aerosols were collected with high temporal resolution (3 hours) during a four-day period in July 2005 The highest Pb concentrations measured coincided with large fireworks during celebration events and associated to high traffic occurrence Our high-resolution data highlights the impact that a singular transient event can have on air quality even in a megacity Under meteorological conditions non-conducive to pollutant dispersion Pb and particulate matter concentrations accumulated during the night leading to the highest concentrations in aerosols collected early in the morning of the following day The stable isotopes of Pb suggest that emissions from traffic remain an Important source of Pb in Sao Paulo City due to the large traffic fleet despite low Pb concentrations in fuels (C) 2010 Elsevier BV All rights reserved
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O presente trabalho apresenta estudos sistemãticos da caracterização do carvão de Candiota em termos do seu beneficiamento. O carvão de Candiota possui caracteristicas de moabilidade que o indicam como bastantefriável. A geração de finos (-28 malhas) atinge valores superiores a 20% independente do grau de britagem . As distribuições granulométricas resultantes da britagem do carvão obedecem a equação de ROSIN-RAIIMLER-BENNETT, dentro do intervalo previsto (frações menores do ue -4 malhas e maiores do que 100 malhas). Os valores de n e d ' não variam significativamente com a abertura do britador o, que evidencia sua friabiliade. foram estabelecidas equações que relacionam aberturado britador, coeficientes de distribuição e diâmetro médio.Estudos rni croscópicos demonstraram que, o grau de d i-s seminação da matéria inorgânica é muitointenso , e sua liberação atinge malhas muito pequenas (provavelmente menores do que 400 malhas). O teor de cinzas, como por exemplo do grau de disseminação, não variou significativamente com a diminuição de tamanho, como acontece com outros carvões. Foram estabelecidos dois critérios de liberação das particulas em função da quantidade de matéria carbonosa presente nas unidades mistas (20 - 80% e 5 - 95%, respectivamente). Estes indices de partyculas mistas (5 - 95% de matéria carbonosa) mantiveram-se constantes até tamanhos aproximados de 115 malhas, para logo diminuirem nas frações menores. Ainda assim, para frações menores do que 53 micrômetro a quantidade de mistos ( 5 - 95%) foi de 34%. As curvas de lavabilidade deste carvão (tanto da fração grossa quanto afina), reflexo das caracteristicas anteriores, indicam-no como de muito dificil beneficiamento (lavagem). Isto basicamente é devido ao alto grau de "near gravity matterial" presente e de seu grau de liberação. 0s testes de jigagem por bateladas, bem como outros processos de beneficiamento, demonstraram a dificuldade do beneficiamento deste carvão. O melhor teste de jigagem por bateladas, obteve uma recuperação de materia carbonosa de 73, 21 com um teor de cinzas de 45,51 no concretado (alimentação contendo 50% de cinzas). de 37,59% de cinzas (alimentação de 50% de cinzas). Propõe-se, finalmente, um circuito de beneficiamento convencional do carvão de Candiota, incluindo uma classificação do carvão ROM com o objetivo de separar a alimentação em duas frações (+28 e -28 malhas), seguido de um processo de beneficiamento das frações grosseiras por meios densos (tanques), e um tratamento das frações finas por hidrociclonagem. Os resultados obtidos concluem que o carvão de Candiota é o mais dificil de ser lavado dentre os carvões sul-brasileiros devido ao alto teor de cinzas e ao grau de disseminação, sendo que este teor de cinzas não varia muito com a granulometria, o que implica em um grau de liberação muito baixo. Sugere- se como outra alternativa no seu beneficiamento, o estudo de processos não convencionais que incluem um alto grau de cominuiçáo ate completa liberação.
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The worldwide concern regarding the use of sustainable energy and preserving the environment are determining factors in the search for resources and alternative sources of energy and therefore fuel less aggressive nature. In response to these difficulties Biodiesel has emerged as a good solution because it is produced from renewable sources, produces burns cleaner and is easily reproducible. This work was synthesized with biodiesel oil, sunflower via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the blends BX (a proportion of biodiesel X = 5, 10, 15 and 20 %). Atmospheric distillation of the analysis, performed in blends with and without BHT were collected residue generated by each sample and performed a study heat from the thermogravimetric analysis at a heating rate of 10 °C*min-1, nitrogen atmosphere and heating to 600 °C. According to the specifications of Resolution N 7/2008 for biodiesel, it was found that the synthesized material was in accordance with the specifications. For blends showed that the samples are in accordance with the Resolution of ANP N 42/2009. From the TG / DTG curves of the samples of biodiesel, blends and waste can be seen that these show a single loss of thermal decomposition concerning constituents present in each sample. The blends without BHT with ratios of 5%, 10% and 15% biodiesel showed a lower amount of waste (1,07%; 1,09% e 1,10%) to mineral diesel (1,15%). Therefore, it is concluded that the addition of biodiesel with diesel mineral can improve some physico-chemical parameters, but also, depending on the added amount, decreasing the amount of waste generated. This fact is of great importance because the carbonaceous residue can cause problems in mechanical equipment and parts for vehicles, causing more frequent maintenance, and this is not desirable
Estudo térmico dos resíduos gerados da destilação atmosférica das misturas diesel/biodiesel de dendê
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The growing world demand for energy supplied by fossil fuels, a major contributor to the emission of pollutants into the atmosphere and causing environmental problems, has been encouraging governments and international organizations to reflect and encourage the use of alternative renewable sources. Among these new possibilities deserves attention biodiesel, fuel cleaner and easy to reproduce. The study of new technologies involving that source is necessary. From this context, the paper aims at analyzing the thermal stability by thermogravimetric analysis, of the waste generated from atmospheric distillation of mixtures with ratios of 5, 10, 15 and 20% palm biodiesel in diesel with and without addition of BHT antioxidant. It was synthesized biodiesel through palm oil, via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the diesel common indoor type (S1800) from a gas station BR. The diesel was already added with 5% biodiesel, and thus the proportions used for these blends were subtracted from the existing ratio in diesel fuel, resulting in the following proportions palm oil biodiesel: 0% (B5), 5% (B10), 10 % (B15) and 15% (B20). From atmospheric distillation analysis, performed in mixtures with and without BHT were collected residue generated by each sample and performed a thermal study from the thermogravimetric analysis at a heating rate of 10 °C.min-1, nitrogen atmosphere and heating to 600 ° C. According to the specifications of Resolution No. 7/2008 for biodiesel, it was found that the material was synthesized in accordance with the specifications. For mixtures, it was noted that the samples were in accordance with the ANP Resolution No. 42/2009. Given the TG / DTG curves of the samples of waste mixtures with and without BHT antioxidant was able to observe that they showed a single stage of thermal decomposition attributed to decomposition of heavy hydrocarbons and esters and other heavier constituents of the waste sample weighed. The thermal behavior of residues from atmospheric distillation of mixtures of diesel / biodiesel is very important to understand how this affects the proper functioning of the engine. A large amount of waste can generate a high content of particulate material, coke formation and carbonaceous deposits in engine valves, compromising their performance
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This study tested the hypothesis of airborne transmission of Salmonella Agona (Trial I) and Salmonella Typhimurium (Trial II) in weaned pigs. The trials were performed using stainless-steel/glass isolation cabinets connected by air ducts to permit an unidirectional airflow from cabinet 1 (two control pigs) to cabinet 3 (two sentinel pigs), passing through cabinet 2 (two inoculated pigs). Air samples, pooled faecal samples from the floor and rectal swabs were collected daily and assessed by culture and PCR. A fumigation chamber and rubber gloves coupled to the cabinets allowed sampling without opening the system. Trials I and II lasted 15 and 19 days respectively. The recovery of S. Agona and S. Typhimurium and detection of scroconversion in sentinel pigs indicate that airborne Salmonella transmission in weaned pigs over short distances is possible. Further studies on the role of aerosols in the epidemiology of Salmonella in intensive pig production should be performed.
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This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The activities were divided into four stages: study batch adsorption capacity of the adsorbent with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption studies were carried out under the following operating conditions: temperature 40 °C (for the pyrolysis of the sludge T = 600 °C), pressures of 0.55 to 5.05 bar (batch process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7 h and on the fixed bed was around 180 min. The results of this study showed that in batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed CO2 increases with the increases pressure, decreases with temperature increases and rises due the increase of activation temperature adsorbent. In the batch process were evaluated the breakthrough curves, which were compared with adsorption isotherms represented by the models of Langmuir, Freündlich and Toth. All models well adjusted to the experimental points, but the Langmuir model was chosen in view of its use in the dynamic model does not have implications for adsorption (indeterminacy and larger number of parameters such as occurred with others) in solving the equation. In the fixed bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the maximum adsorption percentage 46.7% at 40 °C temperature and 50 mL/min of flow rate. The model was satisfactorily fitted to the three breakthrough curves and the parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45 dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge showed a fast saturation with traces of aerosols presents in the gas phase into the fixed bed under the reaction process
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Although the good performance in organic matter and suspended solids removal, the anaerobic reactors are unable to remove ammonia nitrogen from sewage, which makes indispensable to include a step of post-treatment for removal of ammonia or nitrate as necessary. This paper presents the performance of a new variant technology, where the nitrification unit, preceded by anaerobic units, is a submerged aerated biological filter, without continuous sludge discharge in their daily operation. The oxygenation system is very simple and inexpensive, consisting of perforated hoses and compressors. The anaerobic reactors are a septic tank with two chambers followed (8.82 m³) and two parallel anaerobic filters (36 m³ each) filled with ceramic bricks and conics plastic parts. Both followed aerated filters were filled with cut corrugated conduit. The study evaluated the behavior of the system with constant domestic sewage flow (10 m³/d) and different aeration conditions, are these: stage 01, when applied air flow of 0.01 m³ air/min in both aerated filter; stage 02, remained in the initial air flow rate in the second aerated filter and increased at the first to 0.05 m³ air/min; at last, at last, in stage 03, the air flow rate of first aerated filter was 0.10 m³ air/min and on the second remained at 0.01 m³ air/min. The filter FA1 received load of 0.41 kg COD/m³.d, 0.37 kg COD/m³.d and 0.26 kg COD/m³.d on phases 01, 02 and 03, respectively. The FA2 received loads of 0.25 kg COD/m³.d, 0.18 kg COD/m³.d and 0.14 kg COD/m³.d on phases 01, 02 and 03, respectively. During stage 01, were found the following results: 98% removals of BODtotal and 92% of CODtotal, with effluent presenting 9 mg/L of BODtotal final average and 53 mg/L of CODtotal average; suspended solids removals of 93%, with a mean concentration of 10 mg/L in the final effluent; 47% reduction of ammonia of FA2 to FAN 's, presenting average of 28 mg NNH3/ L of ammonia in the effluent with; the dissolved oxygen levels always remained around 2.0 mg/L. During stage 02, were found removals of 97% and 95% to BODtotal and suspended solids, respectively, with average final concentrations of 8 and 7 mg/L, respectively; was removed 60% of ammonia, whose final concentration was 16.3 mg NNH3/ L, and nitrate was increased to a final average concentration of 16.55 mg N-NO3/L. Finally, the stage 03 provided 6 mg/L of DBOtotal (98% removal) and 23 mg/L of CODtotal (95% removal) of final effluent concentrations average. At this stage was identified the higher ammonia oxidation (86%), with final effluent showing average concentration of 6.1 mg N-NH3/L, reaching a minimum of 1.70 mg N-NH3/L. In some moments, during stage 03, there was a moderate denitrification process in the last aerated filter. The average turbidity in the effluent showed around 1.5 NTU, proving the good biomass physical stability. Therefore, the results demonstrate the submerged biological filters potential, filled with high void ratio material (98%), and aerated with hoses and compressor adoption, in the carbonaceous and nitrogenous matter oxidation, also generating an effluent with low concentration of solids
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The influence of environmental conditions on the indoor radon daughters spatial distribution is studied both theoretically and experimentally. Simple theoretical calculations indicate that ventilation and variation in the size distribution of aerosols should play an important role influencing the spatial distribution of indoor radon decay products, but experimental results indicate that these environmental factors have little influence on the spatial distribution of radon daughters near the walls of indoor environments. We have observed that the maximum effective range of the plate-out effect varies only between I and 3 cm in typical dwellings. (C) 2002 Elsevier B.V. Ltd. All rights reserved.
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OBJETIVO: Monitorar e caracterizar fungos anemófilos e leveduras de fontes bióticas e abióticas de uma unidade hospitalar. MÉTODOS: As coletas foram realizadas mensalmente e em dois períodos, do centro cirúrgico e unidades de terapia intensiva adulto e neonatal em hospital de Araraquara, Estado de São Paulo. Para coleta de fungos anemófilos foi utilizado amostrador tipo Andersen de simples estágio. A pesquisa de leveduras foi feita das mãos e de orofaringe de profissionais de saúde, bem como de superfícies de leitos e de maçanetas das áreas críticas. RESULTADOS: Foram recuperados do centro cirúrgico 32 gêneros de fungos anemófilos e 31 das unidades de terapia intensiva. Os gêneros mais freqüentemente isolados foram Cladophialophora spp., Fusarium spp., Penicillium spp., Chrysosporium spp. e Aspergillus spp. Durante o período de estudo, houve reforma e implantação de uma unidade dentro do hospital, que coincidiu com o aumento na contagem de colônias de Cladophialophora spp., Aspergillus spp. e Fusarium spp. Leveduras foram encontradas em 39,4% dos profissionais de saúde (16,7% das amostras dos espaços interdigitais, 12,1% do leito subungueal e 10,6% da orofaringe) e, em 44% das amostras do mobiliário, com predomínio do gênero Candida (C. albicans, C. guilliermondii, C. parapsilosis e C. lusitaniae) seguido por Trichosporon spp. CONCLUSÕES: Observou-se número relativamente elevado de fungos anemófilos (potencialmente patogênicos) em áreas especiais e níveis expressivos de leveduras em fontes bióticas e abióticas. O monitoramento microbiológico ambiental deve ser realizado, principalmente em salas especiais com pacientes imunocomprometidos, sujeitos à exposição de patógenos do meio ambiente, assim como, advindos de profissionais de saúde.
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A tungsten carbide coating on the integrated platform of a transversely heated graphite atomizer was used as a modifier for the direct determination of Se in soil extracts by graphite furnace atomic absorption spectrometry. Diethylenetriaminepentaacetic acid (0.0050 mol L-1) plus ammonium hydrogencarbonate (1.0 mol L-1) extracted predominantly available inorganic selenate from soil. The formation of a large amount of carbonaceous residue inside the atomizer was avoided with a first pyrolysis step at 600 degreesC assisted by air during 30 s. For 20 muL of soil extracts delivered to the atomizer and calibration by matrix matching, an analytical curve (10.0-100 mug of L-1) with good linear correlation (r = 0.999) between integrated absorbance and analyte concentration was established. The characteristic mass was similar to63 pg of Se, and the lifetime of the tube was similar to750 firings. The limit of detection was 1.6 mug L-1, and the relative standard deviations (n = 12) were typically <4% for a soil extract containing 50 mug of L-1. The accuracy of the determination of Se was checked for soil samples by means of addition/recovery tests. Recovery data of Se added to four enriched soil samples varied from 80 to 90% and indicated an accurate method.
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O presente trabalho objetivou a avaliação da remoção de matéria orgânica carbonácea e nitrogenada, bem como a determinação do fluxo crítico, em biorreator de membranas, com zona pré-anóxica, tratando águas residuárias industriais da produção de aminoácidos. O reator foi operado sob carga orgânica volumétrica de 1,91 kg.DQO.m-3.d-1 e 0,18 kg.NTK.m-3.d-1; a recirculação do reator aeróbio para o reator anóxico foi de quatro vezes a vazão afluente. O reator apresentou médias de remoção de DQO, NTK e NT de 97, 98 e 92%, respectivamente. O sistema de ultrafiltração foi testado em vários fluxos entre 25 e 37 L.m-2.h-1 e determinou-se o fluxo crítico de 28 L.m-2.h-1 quando operado com 11,4 g.L-1 de SST e 35 dias de tempo de retenção celular. Os resultados mostraram que houve viabilidade técnica no uso de biorreator de membranas para remoção de matéria orgânica de águas residuárias industriais da produção de aminoácidos.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Geofísica terrestre (magnetometria e radiometria) foi utilizada como ferramenta de apoio ao mapeamento geológico em uma área de pesquisa mineral da Companhia Mineradora de Minas Gerais (COMIG), denominada Alvo Bueiro, localizada a sudeste da cidade de Morro do Pilar, na Serra do Espinhaço, Estado de Minas Gerais. A integração de informações de geologia de superfície com os dados geofísicos correspondentes permitiu definir quatro zonas: A, B, C e D. A Zona A, caracterizada por altos valores de susceptibilidade magnética e baixos valores de radiometria, é composta por itabiritos do Grupo Serra da Serpentina. A Zona B, pertencente ao mesmo grupo, é constituída por filitos cinza e metassiltitos e mostra baixa susceptibilidade magnética; interrupções nas linhas de contorno foram interpretadas como decorrentes de falhas de empurrão. A Zona C, relacionada à Seqüência Vulcano-Sedimentar Rio Mata Cavalo, é caracterizada por uma expressiva anomalia do campo magnético total em xistos máficos e ultramáficos com lentes de formações ferríferas e filitos carbonosos negros; esta zona hospeda as mais importantes anomalias geoquímicas de ouro conhecidas na área em estudo. A Zona D, correspondente a ortognaisses cisalhados do Complexo Dona Rita, mostra os mais elevados valores de radiometria do Alvo Bueiro e baixas respostas magnéticas.