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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.
981

Avaliação do risco de infecção cruzada através das linhas d água dos equipos odontológicos na rede pública estadual de Alagoas / Assessment of risk of cross infection through the waterlines in public dental units in Alagoas

Lisboa, Guacyra Machado 03 June 2011 (has links)
During routine work, the dental staff and patients are exposed to contamination by water used in dental units, through accidental ingestion or aspiration of aerosols generated by high-speed and air-water syringe. This study evaluated the water quality of the dental equipment of public dental offices in Alagoas, conducting the count of heterotrophic bacteria, filamentous fungi, as well as the presence of total and fecal coliforms and Streptococcus mutans. We collected water from air-water syringe, supply hoses with handpieces disconnected, handpieces with supply hose attached, reservoir and water where the reservoir was filled from six dental offices. To search for heterotrophic bacteria and fungi volumes of 100 μL of pure sample and 10-1 dilution were plated in duplicate on plate count agar medium supplemented with 50 mg.L-1 of Ketoconazole and Sabouraud dextrose agar supplemented with chloramphenicol and amplicilina, 50 mg.L-1 of each. The results were expressed in CFU/mL. For quantification of total and fecal coliforms, we used the method of enzyme substrate (Colilert ®) and the results were expressed in MPN/100ml, according to a table supplied by the manufacturer. The research of S. mutans was accomplished through the use Mitis Salivarius Bacitracin with and without prior disinfection with alcohol 70% of the collection points in Petri dishes and a vial with medium Mitis Salivarius Bacitracin Sucrose without prior disinfection of the collection points. All results were expressed in CFU/mL and subjected to molecular analysis to confirm the identities. We did not observe the isolation of Streptococcus mutans. However the high contamination found indicated that the water was unfit for human consumption can be considered a potential source of cross infections. / Durante a rotina de trabalho, a equipe odontológica e os pacientes estão expostos a contaminação pelas águas utilizadas nas unidades dentais, através da ingestão acidental ou aspiração dos aerossóis gerados pela caneta de alta rotação e seringa tríplice. O presente estudo avaliou a qualidade da água dos equipamentos odontológicos da rede pública estadual de Alagoas, realizando a contagem de bactérias heterotróficas, a presença de coliformes totais e termotolerantes, assim como contagem de fungos filamentosos, potencialmente patogênicos e a presença de Streptococcus mutans. Foram coletadas água, da seringa tríplice, caneta de alta rotação com a peça de mão acoplada e desacoplada às mangueiras, reservatório de água e do local onde era abastecido o reservatório; de seis consultórios odontológicos. Para pesquisa de bactérias heterotróficas e fungos filamentosos volumes de 100 μl da amostra original e da diluição 10-1 foram semeados em duplicata, em meio Plate Count Agar adicionado de 50 mg.L-1 de Cetoconazol e em Agar Sabouraud dextrose adicionado de cloranfenicol e amplicilina, 50 mg.L-1 de cada. Os resultados foram expressos em UFC/mL. Para quantificação de coliformes totais e termotolerantes, foi utilizado o método do substrato enzimático (Colilert®) e os resultados foram expressos em NMP/100 mL, de acordo com tabela fornecida pelo fabricante. A pesquisa de S. mutans foi realizada utilizado o meio Mitis Salivarius Bacitracina com e sem desinfecção prévia com álcool a 70% dos pontos de coleta em placas de Petri e em um laminocultivo com meio Mitis Salivarius Bacitracina Sacarose sem limpeza prévia dos pontos de coleta. Todos os resultados foram expressos em UFC/mL e submetidos a testes moleculares para confirmação das identidades. Não foi observado o isolamento de Streptococcus mutans. Porem a alta contaminação encontrada indicou que a água era imprópria para o consumo humano; podendo ser considerada uma fonte potencial de infecções cruzadas.
982

Contaminação de agrotóxicos na água para consumo humano no RS : avaliação de riscos, desenvolvimento e validação de método empregando SPE e LC-MS/MS

Zini, Luciano Barros January 2016 (has links)
Os agrotóxicos, quando presentes na água, são definidos como micropoluentes: mesmo em baixas concentrações, conferem à água características de toxicidade. Aponta-se o RS como o quarto estado do Brasil com maior volume de vendas anuais de agrotóxicos, chegando a mais de 50 mil toneladas por ano. Desde 2014 está em vigência no território gaúcho uma portaria estadual que acrescenta a exigência de 46 parâmetros de agrotóxicos no padrão de potabilidade da água, além dos 27 já exigidos pela portaria nacional. Neste trabalho, 89 pesticidas foram avaliados conforme três métodos teóricos de predição de risco de contaminação em mananciais subterrâneos e superficiais: índice Ground Ubiquity Score (GUS), método Screening da USEPA e método de GOSS, baseados nas propriedades físico-químicas dos pesticidas. Nos anos de 2015 e 2016, foram realizadas 143 coletas de água para consumo humano em 45 municípios da bacia hidrográfica do Alto Jacuí (G-50), a que possui a maior taxa de aplicação de agrotóxicos do estado, para análises de vigilância através de laboratório contratado, envolvendo os 89 pesticidas presentes na portaria nacional e estadual. Em paralelo, 183 pesticidas presentes em uma solução-padrão foram empregados no desenvolvimento de um novo método de análise multiresíduos, com etapas de pré-tratamento por filtração seguidas por extração em fase sólida e LC-MS/MS, aplicada para os três maiores municípios da G-50 (Carazinho, Soledade e Cruz Alta) em amostras de água bruta e tratada, durante quatro períodos de aplicação de agrotóxicos dos principais cultivos agrícolas da região. Dos pesticidas mencionados nas portarias nacional e estadual, 12 foram classificados com o maior risco de contaminação tanto em água superficial e subterrânea de acordo com os três métodos teóricos empregadas. Nas análises de vigilância foi detectado permetrina em Carazinho e alaclor em Espumoso. No método desenvolvido, 75 pesticidas foram validados de acordo com os critérios propostos e atingiram limites de detecção (LD) e limites de quantificação (LQ) que variaram de 10 a 300 ng L-1. Na aplicação do método nas coletas dos três municípios da G-50 não houve detecção de nenhum pesticida. / Agrochemicals, when present in water, are defined as micropollutants, thus giving the water toxic characteristics, even at low concentrations. The Rio Grande do Sul state in Brazil was found to rank fourth in annual agrochemical sales in the country, surpassing 50 thousand tons per year. A state regulation in effect in the RS state since 2014 requires the inclusion of 46 new agrochemical parameters concerning the standards for potable drinking water, in addition to 27 existing parameters mandated by national ordinance. Seventy-five pesticides were evaluated based on three theoretical methodologies of contamination risk prediction in underground and surface water sources, by measuring the physicochemical properties of pesticides: GUS index, USEPA screening method and Goss method. In 2015 and 2016, 143 water samples were collected from sources of potable water in 45 municipalities located in the Alto Jacuí river basin, a region which has the highest pesticide application rate in the RS state. A private laboratory analyzed samples from 89 pesticides present in the national and state regulation. Paralely, 183 pesticides were evaluated by a new multi-residue analysis method. Filtration was conducted in the pre-treatment steps, followed by a solid phase extraction liquid chromatography coupled with mass spectrometry analysis (SPE-LC-MS/MS) of raw and treated water samples from the three largest G-50 municipalities (Carazinho, Soledade and Cruz Alta), during the four pesticide application periods of the main crops cultivated in the region. Twelve pesticides were classified as of high risk in terms of contamination for both surface and groundwater, in accordance with the three theoretical methodologies implemented. During analysis of the surveillance data collected, the pesticides permethrin and alachlor were found in Carazinho and Espumoso, respectively. Through the methodology developed, 75 pesticides were evaluated according to the criteria proposed, reaching lower detection limit (LD) and quantification limit (LQ) ranging from 10 to 300 ng L-1, respectively. During the implementation of the methodology for sample collections in the three G-50 municipalities, no pesticides were detected.
983

Physical Layer Security in Training-Based Single-Hop/Dual-Hop Massive MIMO Systems

Timilsina, Santosh 01 August 2018 (has links)
The broadcast nature of wireless medium has made information security as one of the most important and critical issues in wireless systems. Physical layer security, which is based on information-theoretic secrecy concepts, can be used to secure the wireless channels by exploiting the noisiness and imperfections of the channels. Massive multiple-input multiple-output (MIMO) systems, which are equipped with very large antenna arrays at the base stations, have a great potential to boost the physical layer security by generating the artificial noise (AN) with the exploitation of excess degrees-of-freedom available at the base stations. In this thesis, we investigate physical layer security provisions in the presence of passive/active eavesdroppers for single-hop massive MIMO, dual-hop relay-assisted massive MIMO and underlay spectrum-sharing massive MIMO systems. The performance of the proposed security provisions is investigated by deriving the achievable rates at the user nodes, the information rate leaked into the eavesdroppers, and the achievable secrecy rates. Moreover, the effects of active pilot contamination attacks, imperfect channel state information (CSI) acquisition at the base-stations, and the availability of statistical CSI at the user nodes are quantified. The secrecy rate/performance gap between two AN precoders, namely the random AN precoder and the null-space based AN precoder, is investigated. The performance of hybrid analog/digital precoding is compared with the full-dimensional digital precoding. Furthermore, the physical layer security breaches in underlay spectrum-sharing massive MIMO systems are investigated, and thereby, security provisions are designed/analyzed against active pilot contamination attacks during the channel estimation phase. A power-ratio based active pilot attack detection scheme is investigated, and thereby, the probability of detection is derived. Thereby, the vulnerability of uplink channel estimation based on the pilots transmitted by the user nodes in time division duplexing based massive MIMO systems is revealed, and the fundamental trade-offs among physical layer security provisions, implementation complexity and performance gains are discussed.
984

VIBRATIONAL SPECTROSCOPY ANALYSES OF THE DEGRADATION AND CONTAMINATION OF ENGINE OIL LUBRICANTS COUPLED WITH MULTIPLE SPECTROSCOPIC TECHNIQUES

Holland, Torrey 01 August 2018 (has links)
The spectral analysis techniques afforded us from the field of physics has enabled us to explore the spectral signatures of trace contaminants and degradation products in used or in service engine oil through atomic and molecular spectroscopy. Here we have examined the need to address proper preparation of calibrating samples for infrared spectroscopy analysis by inducing emulsification and have evaluated multiple procedures for proper emulsification of samples with the intent to help establish the protocols that are not explicitly set forth in the ASTM International standard. We have also explored the use of Fourier-transform infrared spectroscopy techniques to examine the suppression of the O–H stretching mode of water due to the influence of ethylene glycol, which may help in the quantification of water when both are present in oil. This was done in conjunction with exploring alternative methods for direct and indirect measurement of the glycol contamination by use of UV/Vis spectroscopy, Raman, and laser-induced breakdown spectroscopy. An exploration of FT-IR and UV/Vis data on the oxidation of oil by means of ANOVA calculations has led to the reporting of highly significant differences in the data of differing oxidation times and in regions of the spectrum not known to have been previously reported.
985

Synthesis of smart nanomaterials for preconcentration and detection of E.coli in water

Mahlangu, Thembisile Patience 06 1900 (has links)
It is common knowledge that water is one of the basic needs for human beings. However, the consumption of contaminated water can lead to waterborne diseases and fatalities. It is, therefore imperative to constantly monitor the quality of potable water. There are numerous technologies used for water quality monitoring. These technologies are relatively effective however these tests are expensive and complex to use, which then require experienced technicians to operate them. Other tests are not rapid, making consumers of water susceptible to waterborne diseases. In this study, dye-doped, surface functionalized silica nanoparticles (SiNPs) and surface-functionalized magnetic nanocomposites (MNCs) were proposed as materials that can be applied in order to reduce the time taken to get results as well as to make the processes less complex and portable. The aim of this study was to synthesize and characterize surface functionalized dye-doped SiNPs and surface functionalized MNCs for detection and preconcentration of in water. Additionally, proof of concept had to be shown using the synthesized materials. SiNPs were the materials of choice due to their easily functionalized surfaces and their strong optical properties. SiNPs are photostable and they do not leach in solution due to the inert nature of the silica matrix in aqueous media. MNCs were chosen as materials of choice for preconcentration of E. coli in water because they are easy to synthesize and they can be applied in various biological applications due to their functional groups. SiNPs were synthesized using the water-in-oil microemulsion. The SiNPs were further functionalized with amine and carboxyl groups and avidin. Thereafter, they were bioconjugated with biotinylated anti-E. coli antibodies. The pure and surface functionalized SiNPs were characterized using ATR-FTIR spectroscopy, FE-SEM, HR-TEM, Zeta Sizer, UV-vis spectroscopy and spectrofluorometry. The application of the dye—doped surface functionalized SiNPs in E. coli detection was characterized using the fluorescence plate reader. The SiNPs were spherical and uniform in size. They increased in size as they were being functionalized, ranging from 21.20 nm to 75.06 nm. The SiNPs were successfully functionalized with amine and carboxyl groups as well as with avidin and antibodies. Two methods were investigated for carboxyl group attachment (direct and indirect attachment) and the direct attachment method yielded the best results with a surface charge of -31.9 mV compared to -23.3 mV of the indirect method. The dye loading was found to be 1% after particle synthesis. The optical properties of the Ru(Bpy) dye were enhanced 3 fold when they were encapsulated in the Si matrix. The SiNPs were binding to the E. coli cells and enabled detection. MNCs were synthesized through in-situ polymerization. The MNCs were characterized using ATR-FTIR spectroscopy, SEM, TEM and XRD. The MNCs were successfully functionalized with carboxyl groups. The increase in size of the nanocomposites as seen in SEM images proved that the Fe3O4 was successfully encapsulated in the polymer matrix. The MNCs were proven to be magnetic by a simple magnetism test whereby they were separated in an aqueous solution using an external magnetic field. The antibody-labelled MNCs were binding to the E. coli cells as shown in TEM images. E. coli cells were removed from water at varying concentrations of 1x106 CFU/mL to 1x109 CFU/mL at 10 mL volumes. This study has demonstrated that dye-doped SiNPs amplify the signal of E. coli cells using fluorescence. The study has also demonstrated that the MNCs can be applied in sample preconcentration and enrichment for E. coli detection. However, further studies should investigate and optimize the combination of the two techniques in a point of use device for water quality testing of 100 mL-samples as per the requirement of the SANS 241 standard. / Civil and Chemical Engineering / M. Tech. (Chemical Engineering)
986

Estudo da ocorrência de arsênio, cobre, chumbo e zinco em drenagens na área da mina Cerro Rico em Lavras do Sul – RS - Brasil

Silva, Amanda Garcia da January 2017 (has links)
Submitted by Rosimeri Vergara (rosimerivergara@unipampa.edu.br) on 2018-11-14T21:01:08Z No. of bitstreams: 1 Dissertação Amanda Garcia da Silva 2017.pdf: 3259899 bytes, checksum: 470c3b10660c990219f4d523aede3d02 (MD5) / Approved for entry into archive by Dayse Pestana (dayse.pestana@unipampa.edu.br) on 2018-11-19T16:13:59Z (GMT) No. of bitstreams: 1 Dissertação Amanda Garcia da Silva 2017.pdf: 3259899 bytes, checksum: 470c3b10660c990219f4d523aede3d02 (MD5) / Made available in DSpace on 2018-11-19T16:13:59Z (GMT). No. of bitstreams: 1 Dissertação Amanda Garcia da Silva 2017.pdf: 3259899 bytes, checksum: 470c3b10660c990219f4d523aede3d02 (MD5) Previous issue date: 2017 / A mineração é uma atividade básica da economia mundial, e em Lavras do Sul está presente desde meados do século XVIII. No entanto, as atividades de exploração e beneficiamento do ouro geraram muitos resíduos, sendo muitos deles tóxicos. Como a região foi uma área de intensa mineração e tendo em vista os riscos da contaminação de águas por metais pesados, este trabalho propõe-se a averiguar a contaminação por alguns metais que pode eventualmente afetar o bem-estar da população e a integridade do meio ambiente. Deste modo, foram realizadas análises para a determinação da presença e concentração de chumbo, cobre, zinco e arsênio devido aos efeitos tóxicos conhecidos destes metais no ambiente aquático, e sua relação direta com as atividades de mineração de ouro, nos mananciais e sedimentos na região da mina de ouro desativada Cerro Rico, para isto foi empregada a Espectrometria de Emissão Atômica com Plasma Acoplado Indutivamente (ICP OES). Além disso, foram realizados testes físicos e químicos para categorizar as águas em relação a sua qualidade. Os dados obtidos pelas análises de águas foram tratados por meio de uma simulação computacional, para reações pertinentes ao meio, com o uso do software Phreeqc. Os resultados das análises de qualidade de água indicaram que a alcalinidade total e a Demanda Bioquímica de Oxigênio (DBO) apresentam valores inadequados para a as águas doces de classe 3. Todos os resultados foram comparados aos limites estabelecidos pela FEPAM e CONAMA. Detectou-se a presença de Pb, Cu, Zn e As nas amostras de águas, representados, principalmente, pelas espécies H2AsO4-, HAsO42-, Cu2+, Cu+, CuOH+, Pb2+, PbOH+, Zn2+ e ZnOH+, as quais apresentam-se em concentrações classificadas quimicamente como subsaturadas, exceto pelo CuOH+. Contudo, apenas o cobre excedeu os limites estabelecidos pela legislação. Outrossim, as análises realizadas nas amostras de sedimentos comprovaram a presença e concentrações acima dos valores de referência adotados pela FEPAM, para o cobre, para o chumbo e para o zinco, enquanto que o arsênio não foi detectado pelo método utilizado. As maiores acumulações de metal no sedimento foram de cobre, seguidos pelo chumbo e zinco. Conclui-se que há contaminação no entorno da Mina Cerro Rico, por cobre, chumbo e zinco, e que estes estão presentes no ambiente, principalmente, aderidos aos sedimentos. / A mining is a basic activity in the world economy, and in Lavras do Sul the activity has been present since century XVIII. However, as exploration and processing of gold, generated many wastes, many of them toxic. How the region was a intense mining area for a while, the risks of contaminated the water by heavy metals, it became necessary research about that, taking into account the well-being of the population and environmental integrity. That way, were made analysis to determinate the presence and concentration of lead, copper, zinc and arsenic for the fact that’s elements are toxic in the aquatic environments, and their direct relationship with gold mining activities, in the springs and sediments in the Cerro Rico, for this was used the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP OES). In addition, physical and chemical tests were performed to categorize the quality of the waters. The data obtained by the analysis are treated by a computer simulation, for relevant reactions to the environment, using the Phreeqc software. That’s results indicated that total alkalinity and a Biochemical Oxygen Demand (BOD) presented inadequate results for a water class (3) analyzed. All the results were compared to the limits established by FEPAM and CONAMA. Were detected the presence of Pb, Cu, Zn and As in the water samples, mainly represented, by species H2AsO4-, HAsO42-, Cu2+, Cu+, CuOH+, Pb2+, PbOH+, Zn2+ and ZnOH+, which present in concentrations classified chemically how subsaturated, except for CuOH+. However, only copper has exceeded the limits set by legislation. The sediment analysis showed the presence and concentrations above the reference values adopted by FEPAM, for copper, for lead and for zinc, while arsenic was not detected by the method used. The largest accumulations were of copper, followed by lead and zinc. Concludes that the verify area around the Cerro Rico’s mine is contaminated, by copper, lead and zinc, and that these are present in the environment, mostly, on the sediments.
987

Adaptação de um edômetro com controle de sucção para a determinação da curva característica de solos contaminados por óleo diesel / Adaptation of an edometer with suction control for the determination of the retention curve of soil contaminated by diesel oil

Taytelbaum, Leandro Bergmann January 2008 (has links)
A presença de compostos orgânicos no solo proporciona o desenvolvimento de uma fase adicional nos poros, imiscível com a fase aquosa e gasosa pré-existentes. A característica de imiscibilidade destes compostos, denominados de fase livre não aquosa (“nonaqueos phase liquid” – NAPL), torna a avaliação de um solo contaminado por tais substâncias bastante complexa. Dentre as substâncias pertencentes a este grupo NAPL, destacam-se os produtos derivados do petróleo. As propriedades mais importantes na avaliação de um solo contaminado por NAPL são suas relações constitutivas. Uma destas propriedades relaciona a sucção dos fluídos com suas respectivas saturações, enquanto que a outra relaciona a condutividade relativa dos fluidos com a saturação de cada um destes fluidos. A partir da curva de retenção de um solo contaminado, é possível quantificar de forma indireta a relação condutividade relativa-saturação. Todavia, a obtenção desta curva de retenção para um solo contaminado por NAPL é bastante complexa e está em desenvolvimento, exigindo cuidados na sua determinação. Para isso, assume-se que no interior de um poro contendo água, óleo e ar, o contaminante estará preferencialmente localizado entre a água e o ar. Isto é determinante ao admitir-se que a saturação da água Sw é uma função da sucção mátrica desenvolvida entre a água e o óleo e a saturação total dos líquidos St, (soma da saturação da água e do óleo) é dependente da sucção mátrica gerada entre o óleo e o ar. Esta hipótese possibilita a obtenção das curvas de retenção para sistemas trifásicos ar-NAPL-água a partir dos sistemas bifásicos NAPL-água e ar-NAPL. Assim sendo, o objetivo deste trabalho é desenvolver, a partir de um oedômetro com controle de sucção, um equipamento, denominado de célula multifásica, que permita o controle independente das pressões do ar, do NAPL e da água. Especificamente, este equipamento permitirá a determinação das curvas de retenção para sistemas bi e trifásicos. Para atingir esta meta, foi necessário transformar uma pedra porosa cerâmica comum em uma pedra porosa hidrofóbica (repelente à água), através de um tratamento químico da pedra porosa convencional em uma solução contendo uma substância comercialmente conhecida como Glassclad 18. Este novo equipamento permite o monitoramento da variação do volume de água e de óleo no interior de uma amostra de solo para diversas pressões capilares. Ensaios preliminares foram realizados em uma mistura composta de 70% de um solo arenoso e 30% de um solo argilo-arenoso, sendo o primeiro coletado no estado do Rio Grande do Sul enquanto que o segundo em Santa Catarina. Ambos os solos possuem propriedades físicas bem conhecidas. / The presence of organic compounds in the soil provides the development of an additional phase in the pore space, immiscible with the preexisting water and gaseous phases. This characteristic of immiscibility of such substances, called nonaqueos phase liquids – NAPL’s, turns the evaluation of a soil contaminated by these substances sufficiently complex. Among the substances pertaining to this group, called NAPL, the petroleum products are distinguished. The most important properties in the evaluation of a soil contaminated by NAPL are their constitutive relationships. One of these properties relates the pressure of the fluids with their respective saturations, while the other one relates the relative permeability of the fluids with the saturation of each one of these fluids. From the pressure-saturation constitutive relationship of a contaminated soil, it is possible to quantify indirectly the relative permeability-saturation relationship. However, the evaluation of the pressure-saturation relationship for a soil contaminated by NAPL is sufficiently complex and is in development, demanding considerable care in its determination. For this, it is assumed that, in the interior of a pore contaning water, oil and air, the organic liquid will be preferentially located between the water and air. That is imperative when assuming that water saturation of Sw is a function of the suction developed between the oil-water interface and the total liquid saturation St (sum of water saturation and oil saturation) is dependent of the suction generated between the airoil interfaces. This hypothesis makes possible the evaluation of the pressure-saturation relationship for the three-phase system air-NAPL-water from the two-phase systems NAPLwater and air-oil. Thus, the objective of this work is to develop, from the edometer with pressure control, another equipment, called the multiphase cell, that allows the independent control of the air, NAPL and water pressures. Specifically, this equipment will allow the determination of the pressure-saturation relationship for bi- and three-phase systems. To reach this goal, it was necessary to transform a standard ceramic porous stone in a hidrophobic porous stone (repellent to water), through a chemical treatment of the standard porous stone in a solution containing a substance commercially known as Glassclad 18. This new equipment allows the control of the volume changes of water and oil within a soil sample for different suction. Preliminary tests have been carried out with a mixture composed by 70% of sand and 30% of silt; the first material were collected in the state of the Rio Grande do Sul (Brazil) and the second in the state of Santa Catarina. Both materials have their physical properties well known.
988

Detecção de Paecilomyces variotii pela técnica de PCR / Detection of Paecilomyces variotii by the pcr technique

Gassen, Jorge January 2012 (has links)
A amplificação in vitro de DNA, utilizando reação em cadeia da polimerase (PCR), tem sido estudada como uma alternativa aos tradicionais métodos de detecção de micro-organismos contaminantes em tanques de armazenagem de biodiesel. Neste sentido, objetivou-se padronizar um método rápido e eficaz para detecção de Paecilomyces variotii utilizando-se a técnica de PCR e avaliar o desenvolvimento de P. variotii em amostras contendo diesel puro (B0), mistura diesel/biodiesel (B7) e biodiesel puro (B100). Em sistemas contendo meio mínimo mineral e misturas diesel/biodiesel, após 60 dias, verificou-se que o micro-organismo desenvolveu biomassa significativamente superior em B7 e B100 quando comparados a B0. A técnica de PCR foi capaz de detectar um mínimo de 103 esporos/mL de P. variotii em suspensão com água, correspondente a 0,0144 ng de DNA/μL, e demonstrou ausência de reações inespecíficas frente aos fungos Aspergillus fumigatus e Pseudallescheria boydii. Entretanto, o método mostrou-se ineficaz para detecção de P. variotii em amostras contendo diesel, biodiesel ou misturas de diesel/biodiesel. / The in vitro amplification of DNA using polymerase chain reaction (PCR), has been studied as an alternative to traditional methods for detecting microorganisms contaminating biodiesel storage tanks. In this sense, the aim of this study was to standardize a fast and effective method for detection of Paecilomyces variotii using the PCR technique and evaluate the development of P. variotii in samples containing pure diesel (B0), blend diesel/biodiesel (B7) and pure biodiesel (B100). In systems containing mineral minimal medium and diesel/biodiesel blends after 60 days, it was found that the microorganism biomass developed significantly higher in B7 and B100 when compared to B0. The PCR technique was able to detect a minimum of 103 spores/mL of P. variotii in suspension with water, corresponding to 0,0144 ng DNA/μL, and showed no nonspecific reactions against the fungi Aspergillus fumigatus and Pseudallescheria boydii. However, this method proved to be ineffective for the detection of P. variotii in samples containing diesel, biodiesel or diesel/biodiesel blends.
989

Utilização de rejeito de carvão mineral modificado com HTDMA-Br como sólido sorvente no tratamento de águas contaminadas com nitrato

Illi, Júlia Carolina January 2016 (has links)
Entre as principais fontes de contaminação de águas superficiais e subterrâneas encontra-se o lançamento de despejos industriais e de esgoto doméstico sem tratamento e o uso de fertilizantes agrícolas. Nestas matrizes, o íon nitrato aparece como um dos poluentes que mais influencia na degradação das águas. O nitrato é extremamente estável e solúvel em meio aquoso, o que dificulta a remoção do mesmo de águas e efluentes. Uma alternativa de baixo custo e eficiente para remover este poluente consiste no processo de sorção. Além disso, ressalta-se que diversos sólidos podem ser utilizados como sorvente na remoção de poluentes. Sendo assim, os resíduos sólidos, produzidos por diferentes tipologias industriais, como por exemplo, as carboníferas, que precisam ser gerenciados de forma adequada poderiam ser uma alternativa de sólido sorvente. Durante o beneficiamento do minério, estima-se que cerca de 60 % da massa inicial adicionada ao processo seja descartada como rejeito, sendo esse, fonte de importantes impactos ao meio ambiente. Neste contexto, o presente trabalho propõe verificar a possibilidade de tratamento de águas contaminadas com o íon nitrato através do processo de sorção utilizando rejeito do beneficiamento do carvão como sólido sorvente. Para isso, foram realizados ensaios preliminares com sólido natural e com o mesmo sólido modificado quimicamente. Constatou-se que a superfície do rejeito tratada com solução de HDTMA-Br 60 mM torna o processo mais eficiente. Assim, o sólido modificado foi utilizado para a realização de ensaios de sorção visando obter as melhores condições experimentais. A influência dos seguintes parâmetros foi estudada: o pH (de 2 a 10), o tempo de contato da solução de nitrato com o sólido sorvente (de 0 a 90 minutos) e a concentração de sorvente (de 0 a 2 g/100mL da solução). Ainda, isotermas de equilíbrio foram construídas utilizando as melhores condições operacionais encontradas em três temperaturas diferentes (25, 35 e 45ºC). Os dados experimentais foram ajustados aos modelos de Freundlich, Langmuir, Sips e Redlich Peterson. Os resultados obtidos mostraram que as condições que apresentaram os maiores percentuais de remoção do íon estudado foram: pH 6, 60 minutos de tempo de contato e 1 g/100 mL de sorvente. Já quando comparados os dados com os modelos das isotermas, o modelo que melhor descreve o processo foi Sips, com R2 superior a 0,99 em todas as temperaturas avaliadas. Os dados obtidos indicam que rejeito proveniente do beneficiamento de carvão é satisfatório na remoção do íon nitrato, alcançando remoção superior a 90 %. Já no efluente real estudado, houve remoção acima de 90 % do íon nitrato. Comparando os resultados com os limites estabelecidos pela Portaria 2914 de 2011 do Ministério da Saúde, que dispõe sobre os padrões de qualidade da água, o parâmetro nitrato, após tratamento de sorção proposto no presente trabalho ficou abaixo do valor máximo (10 mg L-1) que consta na Portaria. A pesquisa realizada mostra que é possível tratar águas contaminadas com nitrato utilizando um resíduo industrial proveniente de carboníferas, contribuindo para redução do impacto ambiental em diferentes dimensões. / Among the main sources of water contamination are the release of untreated industrial waste and domestic effluents and the use of agricultural fertilizers. In contaminated water, the ion nitrate appears as one of the effluents with the higher influence on water degradation. Nitrate is extremely stable and soluble in water, which hampers its removal from water and effluents. Is a low-cost and efficient alternative to remove this pollutant is the sorption process, which has been studied for the removal of several compounds. In addition, it is emphasized that various solids can be used as sorbent in the removal of pollutants. Therefore, solid wastes, produced by different industrial typologies, such as carboniferous, that need to be adequately managed could be a solid sorbent alternative. During the ore’s beneficiation, it is estimated that about 60% of the initial mass added to the process is discarded as a residue, which is source of important impacts on the environment. In this context, this work proposes to verify the possibility to treat nitrate-contaminated waters through the sorption process using the residue of coal beneficiation as solid sorbent. Preliminary tests were performed with the natural and chemically-modified solid. It was determined that the residue surface treated with the solution HDTMA-Br 60 mM increases the efficiency of the process. Thus, the modified solid was used for the performance of sorption tests aiming to obtain the best experimental conditions for sorption. The influence of the following parameters was studied: pH (from 2 to 10), contact time of the nitrate solution with the solid sorbent (from 0 to 90 minutes) and sorbent concentration (from 0 to 2 g.100mL-1 of the solution). Furthermore, equilibrium isotherms were built using the best operational conditions found in three different temperatures (25, 35 and 45°C). Experimental data were adjusted to the models of Freundlich, Langmuir, Sips and Redlich Peterson. Obtained results showed that the highest percentages of ion removal were achieved by: pH 6, contact time of 60 minutes and 1g.100mL-1 of sorbent. When comparing the data with isotherm models, Sips was the model that best describes the process, with an R² higher than 0.99 in all evaluated temperatures. The data obtained indicate that the residue from coal beneficiation is satisfactory in the removal of nitrate, reaching a removal rate of more than 90 %. In the real effluent studied, there was removal of more than 90 % of the nitrate ion. Comparing the obtained results with the Ordinance 2914 from 2011 of the Brazilian Health Ministry, , which determines the water quality standards, the nitrate parameter, after sorption treatment proposed in the present study, was below the maximum value (10 mg L -1 ) Contained in the Ordinance. The research shows that it is possible to treat water contaminated with nitrate using an industrial waste from carboniferous, contributing to reduce the environmental impact in different dimensions.
990

Alterações morfofuncionais no intestino de Sphoeroides testudineus decorrentes de diferentes níveis de contaminação em três estuários do litoral do estado de São Paulo /

Marinsek, Gabriela Pustiglione. January 2018 (has links)
Orientador: Renata de Britto Mari / Resumo: As zonas costeiras são ambientes altamente sensíveis aos impactos causados pelas atividades antropogênicas, e o uso desenfreado destas áreas vem gerando grande preocupação, uma vez que tais impactos estão reduzindo drasticamente a biodiversidade destes ecossistemas. O monitoramento destas áreas é de grande valia para detectar os principais impactos e, assim, criar medidas de prevenção e mitigação, sendo realizado através da utilização de biomarcadores, uma vez que estas ferramentas proporcionam a análise das respostas biológicas dos organismos a exposição a contaminação ambiental. Desta forma, este trabalho objetivou avaliar a qualidade ambiental de dois estuários da costa do estado de São Paulo que diferem quanto a densidade demográfica e políticas de preservação ambiental. Para tanto, exemplares de Sphoeroides testudineus foram coletados em três regiões, sendo estas: AR – Estuário do Rio Una (Área Referência - Mosaico Juréia Itatins), A1 – Estuário de Cananéia (Complexo Estuarino Lagunar de Cananéia Iguape) e A2 – Estuário de Santos (Complexo Estuarino de Santos – São Vicente). Os animais foram analisados quanto a biomarcadores de diferentes órgãos (fígado, brânquias, sangue, musculo e intestino) e níveis de organização biológica a fim de proporcionar uma resposta integrada quanto a saúde do organismo. Assim, o objetivo deste estudo foi avaliar a qualidade ambiental dos estuários através da utilização de biomarcadores amplamente utilizados em estudos ecotoxicológicos (fígad... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Coastal zones are highly sensitive to the impacts caused by anthropogenic activities, and the unrestrained use of these areas is of great concern since such impacts are drastically reducing the biodiversity of such ecosystems. The monitoring of these areas is of great value to detect the main impacts and, thus, to create prevention and mitigation measures. The use of biomarkers is widely used in studies that evaluate environmental quality since this tool provides the analysis of organisms' biological responses to exposure to environmental contamination. In this way, this work aimed to evaluate the environmental quality of two estuaries located at the coast of the state of São Paulo that differ in terms of population density and environmental preservation policies. In order to do so, specimens of Sphoeroides testudineus were collected in three regions: AR- Rio Una Estuary (Reference Area - Juréia Itatins Mosaic), A1 - Cananéia Estuary (Lagunar Estuary Complex of Cananéia Iguape) and A2 - Santos Estuary (Estuarine Complex of Santos - São Vicente). The animals were analyzed for biomarkers of different organs (liver, gills, blood, muscle, and intestine) and levels of biological organization in order to provide an integrated response to the health of the organism. Thus, the objective of this study was to evaluate the environmental quality of the estuaries using biomarkers widely used in ecotoxicological studies (liver, gills, muscle, and blood), as well as to evaluate the response... (Complete abstract click electronic access below) / Mestre

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