An inverse method for determining source characteristics for emergency response applications

Following a malicious or accidental atmospheric release in an outdoor environment it is essential for first responders to ensure safety by identifying areas where human life may be in danger. For this to happen quickly, reliable information is needed on the source strength and location, and the type of chemical agent released. We present here an inverse modelling technique that estimates the source strength and location of such a release, together with the uncertainty in those estimates, using a limited number of measurements of concentration from a network of chemical sensors considering a single, steady, ground-level source. The technique is evaluated using data from a set of dispersion experiments conducted in a meteorological wind tunnel, where simultaneous measurements of concentration time series were obtained in the plume from a ground-level point-source emission of a passive tracer. In particular, we analyze the response to the number of sensors deployed and their arrangement, and to sampling and model errors. We find that the inverse algorithm can generate acceptable estimates of the source characteristics with as few as four sensors, providing these are well-placed and that the sampling error is controlled. Configurations with at least three sensors in a profile across the plume were found to be superior to other arrangements examined. Analysis of the influence of sampling error due to the use of short averaging times showed that the uncertainty in the source estimates grew as the sampling time decreased. This demonstrated that averaging times greater than about 5min (full scale time) lead to acceptable accuracy.

Estudo exploratório da deposição de filmes de diamante em alguns substratos cerâmicos

o presente trabalho é um estudo exploratório a respeito da síntese de filmes de diamante via deposiçãoquímica a vapor (CVD) sobre alguns substratos cerâmicos: diboreto de titânio (TiB2), ítria (Y20a), zircão (ZrSi04), zircônia parcialmente e totalmente estabilizada com ítria (Zr02), pirofilita ( Al2Si4OlO(OHh), .alumina (Al2Oa) e nitreto de boro hexagonal (h-BN). Estes substratos foram produzidos, em sua maioria, a partir da sinterização de pós micrométricos em altas temperaturas. Além do estudo em relação a possíveis candidatos alternativos ao tradicional silício para o crescimento de filmes auto-sustentáveis, procuramos encontrar substratos onde o filme aderisse bem e cujas propriedades tribológicas pudessem ser melhoradas com o recobrimento com filme de diamante.Dentre os materiais selecionados, constatamos que a topografia da superfície relacionada à densidade de contornos de grão, desempenha um papel relevante na nucleação do diamante. Além disso, os materiais que favorecem a formação de carbonetos conduziram a melhores resultados na nucleação e crescimento do filme, indicando que a ação da atmosfera reativa do CVD com o substrato também contribui decisivamente para o processo de nucleação. A partir dos resultados obtidos, concluímos que a aderência do filme de diamante ao zircão é excelente, assim como a qualidade do filme, o que pode serexplorado convenientemente caso as propriedades mecânicas do sinterizado de zircão sejam adequadas. No caso da zircônia parcialmente estabilizada, os resultados obtidos foram surpreendentes e este material poderia substituir o convencional substrato de silício para a deposição de filmes auto-sustentados de diamante, com inúmeras vantagens, dentre elas o fato de ser reutilizável e de não ser necessário ataque com ácidos para remoção do substrato, o que evita a geração de resíduos químicos.

Avaliação da produção de biodiesel de microalga Isochrysis galbana via transesterificação in situ

Microalgae are microscopic photosynthetic organisms that grow rapidly and in different environmental conditions due to their simple cellular structure. The cultivation of microalgae is a biological system capable of storing solar energy through the production of organic compounds via photosynthesis, and these species presents growth faster than land plants, enabling higher biomass yield. Thus, it is understood that the cultivation of these photosynthetic mechanisms is part of a relevant proposal, since, when compared to other oil producing raw materials, they have a significantly higher productivity, thus being a raw material able to complete the current demand by biodiesel . The overall aim of the thesis was to obtain biofuel via transesterification process of bio oil from the microalgae Isochrysis galbana. The specific objective was to estimate the use of a photobioreactor at the laboratory level, for the experiments of microalgae growth; evaluating the characteristics of biodiesel from microalgae produced by in situ transesterification process; studying a new route for disinfection of microalgae cultivation, through the use of the chemical agent sodium hypochlorite. The introduction of this new method allowed obtaining the kinetics of the photobioreactor for cultivation, besides getting the biomass needed for processing and analysis of experiments in obtaining biodiesel. The research showed acceptable results for the characteristics observed in the bio oil obtained, which fell within the standards of ANP Resolution No. 14, dated 11.5.2012 - 18.5.2012. Furthermore, it was demonstrated that the photobioreactor designed meet expectations about study culture growth and has contributed largely to the development of the chosen species of microalgae. Thus, it can be seen that the microalgae Isochrysis galbana showed a species with potential for biodiesel production

Transdentinal cytotoxic effects of different concentrations of chlorhexidine gel applied on acid-conditioned dentin substrate

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Permethrin-induced morphological changes in oocytes of Rhipicephalus sanguineus (Acari: Ixodidae) semi-engorged females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Scanning electron microscopic analysis of the effect of Carisolv TM gel on periodontally compromised human root surfaces

The aim of this study was to analyze, under scanning electron microscopy (SEM), the morphologic characteristics of root surfaces after application of CarisolvTM gel in association with scaling and root planing (SRP). Sixty periodontally compromised extracted human teeth were randomly assigned to 6 groups: 1) SRP alone; 2) passive topical application of CarisolvTM + SRP; 3) active topical application of CarisolvTM + SRP; 4) multiple applications of CarisolvTM + SRP; 5) SRP + 24% EDTA; 6) topical application of CarisolvTM + SRP + 24% EDTA. CarisolvTM gel was applied to root surfaces for 30 s, followed by scaling and root planing, consisting of 50 strokes with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, in which the roots were instrumented until a smooth, hard and glass-like surface was achieved. All specimens were further analyzed by SEM. The results showed that the treatment with CarisolvTM caused significant changes in root surface morphology of periodontally compromised teeth only when the chemical agent was actively applied (burnishing technique). CarisolvTM failed to remove the smear layer completely, especially with a single application, independently of the method of application. Multiple applications of CarisolvTM were necessary to achieve a smear layer reduction comparable to that obtained with 24% EDTA conditioning.

Evaluation of alternative methods for the disinfection of toothbrushes

The aim of this study was to evaluate alternative methods for the disinfection of toothbrushes considering that most of the previously proposed methods are expensive and cannot be easily implemented. Two-hundred toothbrushes with standardized dimensions and bristles were included in the study. The toothbrushes were divided into 20 experimental groups (n=10), according to microorganism considered and chemical agent used. The toothbrushes were contaminated in vitro by standardized suspensions of Streptococcus mutans, Streptococcus pyogenes, Staphylococcus aureus or Candida albicans. The following disinfectants were tested: 0.12% chlorhexidine digluconate, 50% white vinegar, a triclosan-containing dentifrice solution, and a perborate-based tablet solution. The disinfection method was immersion in the disinfectant for 10min. After the disinfection procedure, the number of remaining microbial cells was evaluated. The values of cfu/toothbrush of each group of microorganism after disinfection were compared by Kruskal-Wallis ANOVA and Dunn's test for multiple comparisons (5%). The chlorhexidine digluconate solution was the most effective disinfectant. The triclosan-based dentifrice solution promoted a significant reduction of all microorganisms' counts in relation to the control group. As to the disinfection with 50% vinegar, a significant reduction was observed for all the microorganisms, except for C. albicans. The sodium perborate solution was the less effective against the tested microorganisms. Solutions based on triclosan-containing dentifrice may be considered effective, nontoxic, cost-effective, and an easily applicable alternative for the disinfection of toothbrushes. The vinegar solution reduced the presence of S. aureus, S. mutans and S. pyogenes on toothbrushes.

Efeito da ativação química do gel de peróxido de carbamida a 10% no clareamento dental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Latenciação de clorexidina para uso potencial em periodontites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Citotoxicidade direta e transdentinária da clorexidina sobre células odontoblastóides MDPC-23 e análise de sua atividade antimicrobiana in vitro

Pós-graduação em Ciências Odontológicas - FOAR

Estudo da ação do inseticida Tiametoxam na sobrevivência e no comportamento de operárias de Apis mellifera L., 1758 (Hymenoptera: Apidae) em diferentes idades

The bee Apis mellifera has a great importance because it is the most economically valuable pollinator for crops worldwide, ensuring cross-pollination and increasing fruit yield. Moreover, agriculture increasingly develops chemicals to control weeds, fungi and insect pests to ensure productivity. Insecticides are used on a large scale in the state of São Paulo, in cultures of citrus for control of greening. Applications are usually made by aircraft and as a result of the effect derives a significant mortality is observed in apiaries near the plantations. Honey bees can get in contact with such chemical agent through their activities of water harvesting, plant resins, pollen and nectar. Intoxication resulting from this exposure can be lethal, which is easily detectable, or cause effects on the physiology and behavior of the insect. These, in turn are hardly detectable, such as paralysis, disorientation, behavioral changes, but can compromise the entire social structure of the colony, therefore aimed to study the effects of the insecticide Thiamethoxam behavior of honeybees A. mellifera. Newly emerged individuals and with 10 days of age were tested. Applications of 1 μL de Thiamethoxam, diluted in acetone, were made on the dorsal thorax with a microapplicator. Preliminarily, it was observed LD50 twenty four hours after topical treatment of Thiamethoxam. It was found that the LD50 for newly emerged honeybees is 8 ng/bee and for honeybees with 10 days of age is 18 ng/bee. The behaviors were analyzed 1 hour after application of insecticide at doses corresponding to LD50/100, LD50/50, LD50/10 and LD50, besides the control group. In the test reflex proboscis extension, there was impairment of behavior at doses of 8 and 18 ng/bee workers in newly emerged workers and 10 days of age, respectively. And in locomotor behavior was no change only at a dose of 18 ng/bee workers at 10 days of age... (Complete abstract click electronic access below)

Avaliação da toxicidade do azocorante Acid Red 114 antes e após processo de biodegradação por meio de um consórcio de microorganismos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Polidocanol versus hypertonic glucose for sclerotherapy treatment of reticular veins of the lower limbs: study protocol for a randomized controlled trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Free amino acids exhibit anthozoan "host factor" activity: they induce the release of photosynthate from symbiotic dinoflagellates in vitro.

Reef-building corals and other tropical anthozoans harbor endosymbiotic dinoflagellates. It is now recognized that the dinoflagellates are fundamental to the biology of their hosts, and their carbon and nitrogen metabolisms are linked in important ways. Unlike free living species, growth of symbiotic dinoflagellates is unbalanced and a substantial fraction of the carbon fixed daily by symbiont photosynthesis is released and used by the host for respiration and growth. Release of fixed carbon as low molecular weight compounds by freshly isolated symbiotic dinoflagellates is evoked by a factor (i.e., a chemical agent) present in a homogenate of host tissue. We have identified this "host factor" in the Hawaiian coral Pocillopora damicornis as a set of free amino acids. Synthetic amino acid mixtures, based on the measured free amino acid pools of P. damicornis tissues, not only elicit the selective release of 14C-labeled photosynthetic products from isolated symbiotic dinoflagellates but also enhance total 14CO2 fixation.

Concepção de um receptor de cavidade para concentração de energia solar para aplicação em reatores químicos.

Este trabalho dimensionou um receptor de cavidade para uso como reator químico de um ciclo de conversão de energia solar para energia química. O vetor energético proposto é o hidrogênio. Isso implica que a energia solar é concentrada em um dispositivo que absorve a radiação térmica e a transforma em energia térmica para ativar uma reação química endotérmica. Essa reação transforma o calor útil em gás hidrogênio, que por sua vez pode ser utilizado posteriormente para geração de outras formas de energia. O primeiro passo foi levantar os pares metal/óxido estudados na literatura, cuja finalidade é ativar um ciclo termoquímico que possibilite produção de hidrogênio. Esses pares foram comparados com base em quatro parâmetros, cuja importância determina o dimensionamento de um receptor de cavidade. São eles: temperatura da reação; estado físico de reagentes e produtos; desgaste do material em ciclos; taxa de reação de hidrólise e outros aspectos. O par escolhido com a melhor avaliação no conjunto dos parâmetros foi o tungstênio e o trióxido de tungstênio (W/WO3). Com base na literatura, foi determinado um reator padrão, cujas características foram analisadas e suas consequências no funcionamento do receptor de cavidade. Com essa análise, determinaram-se os principais parâmetros de projeto, ou seja, a abertura da cavidade, a transmissividade da janela, e as dimensões da cavidade. Com base nos resultados anteriores, estabeleceu-se um modelo de dimensionamento do sistema de conversão de energia solar em energia útil para um processo químico. Ao se analisar um perfil de concentração de energia solar, calculou-se as eficiências de absorção e de perdas do receptor, em função da área de abertura de um campo de coleta de energia solar e da radiação solar disponível. Esse método pode ser empregado em conjunto com metodologias consagradas e dados de previsão de disponibilidade solar para estudos de concentradores de sistemas de produção de hidrogênio a partir de ciclos termoquímicos.