Resumo Achatina fulica é um molusco terrestre conhecido como caramujo gigante africano que está relacionado a problemas ambientais, econômicos, urbanos e de saúde pública. Como medidas de controle para esse molusco, são utilizados sal de cozinha (NaCl) e óxido de cálcio (CaO), e as iscas são compostas de metaldeído. No entanto, essas medidas têm toxicidade ambiental e impactam o solo. Desta forma, produtos naturais foram testados neste molusco para descobrir e desenvolver uma substância para combater esta praga urbana e agrícola. Este artigo tem como objetivo avaliar estudos envolvendo produtos naturais para controle da população de Achatina fulica. Artigos e trabalhos publicados em livros foram incluídos no presente trabalho. Um total de 1.103 trabalhos foram encontrados durante a pesquisa. Destes, 14 trabalhos atendiam ao objetivo desta revisão e foram incluídos neste artigo. Os testes não possuem padronização metodológica, não possuem concentração máxima para serem considerados ativos ou tempo máximo de exposição. Observou-se uma falta de padronização na metodologia de testes em A. fulica. A realização de testes em outras fases da vida do molusco, bem como testes que analisem outros parâmetros, são essenciais. Apenas um artigo analisado apresentou análise fitoquímica. Também não foram relatados testes de ecotoxicidade. Alguns extratos apresentaram resultados promissores, com destaque para o extrato aquoso de Capsicum frutescens. Mais estudos investigando a atividade molusquicida de produtos naturais sobre A. fulica são necessários. É muito relevante que os novos estudos apresentem uma análise fitoquímica dos extratos testados, bem como estudos de ecotoxicidade.

Abstract Achatina fulica is a terrestrial mollusk known as the giant African snail that is related to environmental, economic, urban, and public health problems. As control measures for this mollusk, cooking salt (NaCl) and calcium oxide (CaO) are used, and baits are composed of metaldehyde. However, these measures have environmental toxicity and impact the soil. In this way, natural products have been tested on this mollusk to discover and develop a substance to combat this urban and agricultural pest. This article aims to evaluate studies involving natural products to control the population of Achatina fulica. Articles and works published in books were included in the present work. A total of 1,103 works were found during the search. Of these, 14 works met the objective of these review and were included in this article. The tests do not possess methodological standardization, do not have a maximum concentration to be considered active, or a maximum exposure time. A lack of standardization in the methodology of tests on A. fulica was observed. The performance of tests on other life stages of the mollusk, as well as tests that analyze other parameters, are essential. Only one article analyzed presented phytochemical analysis. No ecotoxicity tests were reported either. Some extracts showed promising results, highlighting the aqueous extract of Capsicum frutescens. More studies investigating the molluscicidal activity of natural products on A. fulica are needed. It is very relevant that the new studies present a phytochemical analysis of the tested extracts, as well as ecotoxicity studies.

Abstract This research evaluates the behavior of plaster with a water-repellent additive when submitted to a natural aging process. Casting plaster and silane/siloxane-based water-repellent were used as materials. The water/plaster ratio was set at 0.7 and the contents of 0.2% and 0.4% of water-repellent were used, in relation to the plaster mass. Plaster pastes without water-repellent (reference) and containing mass water-repellent were evaluated at ‘zero’ age and after 30, 60, 90, 120, and 150 days of natural aging. After 150 days of natural aging, it was observed that the mechanical properties of the material (compressive strength and hardness) did not undergo significant variations and remained above the minimum required by a standard. The addition of water-repellent resulted in a considerable reduction in water absorption, demonstrating the water repellency capacity of the material, compared to the reference specimen.

Resumo Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos: controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25 mg.Kg-1, Pb = 180 mg.Kg-1), dobro (Ag = 50 mg.Kg-1, Pb = 360 mg.Kg-1) e triplo (Ag = 75 mg.Kg-1, Pb = 540 mg.Kg -1) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato fotossintético na parte aérea das plantas. De forma geral o elemento químico Pb se mostrou mais tóxico que Ag, nestas condições experimentais.

Abstract This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

Abstract This study aimed to describe and characterize the stages of gonadal development of females of Xiphopenaeus kroyeri caught by artisanal fishers in Espírito Santo state, southeastern region of Brazil. All females (n= 1,831) were subjected to macroscopic and microscopic morphological analysis (n= 333) of the ovaries. From the morphology, coloration and degree of turgidity of the fresh ovary, macroscopic analysis determined five stages of gonadal development. The macroscopic analysis showed difficulties in differentiating the immature and spawning stages due to the similarity between the colors of the ovaries, which confirms the need to perform the macroscopic and histological analysis simultaneously for fisheries management studies. Microscopic observations allowed us to analyze the following six stages of cell development: oogonia, previtellogenic oocytes, primary vitellogenic oocytes, secondary vitellogenic oocytes, mature oocytes and atretic oocytes. From this, five stages of gonadal development were defined, i.e., immature, early development, advanced development, mature and spawned. The presence of peripheral bodies was not observed in this species. These results help to clarify and better understand the reproductive and population aspects of the Atlantic Seabob, which are fundamental for the establishment of management and conservation measures of this resource.

Resumo Este estudo teve como objetivo descrever e caracterizar os estágios de desenvolvimento gonadal de fêmeas de Xiphopenaeus kroyeri capturado por pescadores artesanais no Estado do Espírito Santo, região sudeste (Região sudeste = Rio de Janeiro, São Paulo, Minas Gerais e Espírito Santo) do Brasil. Todas as fêmeas (n= 1.831) foram submetidas à análise morfológica macroscópica e microscópica (n= 333) dos ovários. A partir da morfologia, coloração e grau de turgidez do ovário fresco, a análise macroscópica determinou cinco estágios de desenvolvimento gonadal. A análise macroscópica mostrou dificuldades em diferenciar os estágios imaturo e reprodutivo devido à semelhança entre as cores dos ovários, o que confirma a necessidade de realizar a análise macroscópica e histológica simultaneamente para estudos de manejo pesqueiro. As observações microscópicas permitiram analisar os seguintes seis estágios de desenvolvimento celular: oogônias, ovócitos prévitelogênicos, ovócitos em vitelogênese primária, ovócitos em vitelogênese secundária, ovócitos maduros e ovócitos atrésicos. A partir disso, foram definidos cinco estágios de desenvolvimento gonadal, ou seja, imaturo, desenvolvimento inicial, desenvolvimento avançado, maduro e desovado. A presença de corpos periféricos não foi observada nesta espécie. Estes resultados ajudam a esclarecer e compreender melhor os aspetos reprodutivos e populacionais do camarão do Atlântico, que são fundamentais para o estabelecimento de medidas de gestão e conservação deste recurso.

Abstract Guaco is a common medicinal plant in Brazil used for the treatment of respiratory diseases. Coumarin serves as a chemical marker for quality control of products derived from guaco. In this study, the drying kinetics and coumarin yield of guaco leaves dried with and without treating the surface with ethanol were evaluated. The drying experiments were carried out in a forced convection tunnel at 50 and 60 ºC temperatures and air velocities of 0.42 and 0.84 m/s. The results show that the samples with ethanol experienced faster water evaporation during drying experiments, thereby reducing the drying time by up to 35%, and also had higher yields of coumarin. Storage experiments and color analysis were also performed. Treatment of dried guaco leaves with ethanol resulted in color degradation, but increased shelf life by 20%.

Few studies have focused on water deficit for sugarcane, whose damage could be reduced with Si, as shown in other crops. This study aimed to determine whether Si fertilization enhances the best recovery of sugarcane after two periods of the formative phase (tillering and early grand growth) for RB86-7515 (drought tolerant) and RB85-5536 (drought sensitive), and which growth phase is beneficial for each cultivar. It was investigated: 1) the effect of Si fertilization on total Si uptake, and on soluble Si in soil; 2) whether Si uptake could provided increased stalk yield, juice quality, dry biomass compared to well-watered treatments. Two experiments were conducted in pots under greenhouse: one with RB86-7515 and another with RB85-5536. Treatments were: 1-Non-Deficit+Si, 2-Non-Deficit-Si, 3-Early Deficit (ED)+Si, 4-ED-Si, 5-Late Deficit (LD)+Si, and 6-LD-Si. Silicon fertilization provided best recovery of sugarcane (superior sugar, stalk yield, and dry biomass) after early and late water deficit compared to its absence for both cultivars. For RB85-5536, Si fertilization propitiated similar recovery for water deficit and continuous irrigation treatments. No differences were observed between periods of water deficit. Therefore, Si fertilization at planting should be considered another tool for reducing the damage caused by water deficit in sugarcane.

Abstract Effects of phosphorus addition to HZSM-5 on ethanol conversion to propylene were evaluated. Catalysts were characterized by XRF, XRD, nitrogen adsorption, 27Al and 31P MAS NMR, n-propylamine and ammonia TPD. Increasing P content decreased the strength and density of acid total sites. Ethanol dehydration was carried out in a fixed bed reactor operating at atmospheric pressure. Conversion was around 100% for all catalysts. 1.2 wt% of P catalyst showed the highest propylene yield, and was used to evaluate temperature and ethanol partial pressure effects on the product distribution. The highest propylene accumulated productivity was obtained for an ethanol partial pressure of 0.4 atm. Propylene formation was favored in the temperature range 475-500 °C. Significant changes in the product distribution as a function of time on stream were observed at higher temperatures, suggesting stronger catalyst deactivation. The ethylene yield decreased up to 500 °C, rising significantly at 550 °C, possibly due to heavier product cracking reactions.

Abstract The high octane number of pyrolysis gasoline (PYGAS) explains its insertion in the gasoline pool. However, its use is troublesome due to the presence of gum-forming chemicals which, in turn, can be removed via hydrogenation. The use of Langmuir-Hinshelwood kinetic models was evaluated for hydrogenation of styrene, a typical gum monomer, using Pd/9%Nb2O5-Al2O3 as catalyst. Kinetic models accounting for hydrogen dissociative and non-dissociative adsorption were considered. The availability of one or two kinds of catalytic sites was analyzed. Experiments were carried out in a semi-batch reactor at constant temperature and pressure in the absence of transport limitations. The conditions used in each experiment varied between 16 - 56 bar and 60 - 100 ºC for pressure and temperature, respectively. The kinetic models were evaluated using MATLAB and EMSO software. Models using adsorption of hydrogen and organic molecules on the same type of site fitted the data best.

RESUMOOs efeitos da inserção de fibras de aço em concretos têm sido amplamente estudados com o objetivo de investigar possíveis modificações nas propriedades mecânicas, tais como, o aumento da resistência à tração, ductilidade, rigidez, tenacidade (capacidade de absorção de energia), e durabilidade. Uma das consequências imediatas dessa adição é a mitigação do comportamento frágil do concreto, de forma que o material passe a ter novas exigências de qualidade. Nesse contexto, é de grande importância o conhecimento espacial da distribuição de toda estrutura interna desses materiais. A microtomografia computadorizada tridimensional é uma técnica utilizada na caracterização de estruturas internas de diversos materiais, baseada na interação dos raios X com o objeto inspecionado, sendo considerado um ensaio não destrutivo. Propriedades morfológicas e topológicas podem ser obtidas diretamente em três dimensões através da reconstrução matemática das radiografias, o que possibilita analisar, por exemplo, a porosidade e a distribuição de diversos objetos. Nesse contexto, o objetivo desse trabalho é a investigação da distribuição espacial das fibras de aço, assim como da porosidade em amostras de concreto. Para tal, foi utilizado um sistema de microtomografia calibrado para operar com uma tensão de 80 KV, corrente elétrica de 100 µA e um tamanho de pixel igual a 24 µm. Os resultados mostraram uma porosidade baixa e que as fibras de aço não estão distribuídas uniformemente ao longo da amostra.

ABSTRACTThe effects of the inclusion of steel fibers in concrete have been widely studied in order to investigate possible changes in mechanical properties, such as the increase in tensile strength, ductility, stiffness, toughness (energy absorption capacity), and durability. An immediate consequence of this addition is the mitigation of concrete's brittle behavior, so that the material meets new quality requirements. In this context, it is important to study the spatial distribution of the entire internal structure of these materials. Three-dimensional computed microtomography is a non-destructive inspection technique used to characterize the internal structures of various materials based on X-ray interaction with the inspected object. Topological and morphological properties can be obtained directly in three dimensions by means of mathematical reconstruction of the radiographs, which allows analyzing, for example, porosity and distribution of objects. In this context, the aim of this study is to investigate the spatial distribution of steel fibers, as well as of porosity in reinforced concrete samples. To this end, we used a microtomography system calibrated to operate at a voltage of 80 kV, electric current of 100 μA and a pixel size equal to 24 µm. The results showed low porosity and that the steel fibers were not uniformly distributed throughout the sample.

RESUMOObjetivou-se avaliar a sensibilidade dos valores genéticos para características de qualidade da carne em codornas de corte alimentadas com dietas contendo diferentes relações de (metionina + cistina): lisina, do nascimento aos 21 dias de idade, por meio de modelos de normas de reação. Utilizaram-se 9011 informações de qualidade de carne referentes a 1400 progênies de 80 reprodutores e 160 matrizes de duas linhas (LF1 e LF2). Para o ajuste dos modelos de regressão aleatória, foi usado o programa WOMBAT, considerando-se nas análises homogeneidade de variância residual. As codornas foram alimentadas do nascimento aos 21 dias de idade com dietas contendo as relações 0,61; 0,66; 0,71; 0,76 e 0,81 de (metionina + cistina): lisina, mantendo os níveis de proteína bruta de 26,12% e de energia em 2900 kcal EM/kg da dieta. Dos 22 aos 35 dias de idade, todas as codornas foram alimentadas com dieta contendo 22% de proteína bruta e 3050 kcal EM/kg da dieta. As estimativas da variância genética e da herdabilidade foram influenciadas pelo gradiente ambiental e pela linha, com mudanças nessas estimativas com o aumento do gradiente ambiental. Os valores genéticos das características de qualidade de carne referentes a cada uma das linhas se alteraram com o aumento das relações de aminoácidos das dietas em razão das mudanças no ordenamento dos valores genéticos, evidenciando a existência da interação genótipo x nível de relação dos aminoácidos da dieta para características de qualidade de carne. Predições de valores genéticos de características de qualidade de carne com base em determinada relação de (metionina + cistina): lisina da dieta não são válidas para outras relações desses aminoácidos.

ABSTRACTThis study aimed to evaluate the sensitivity of breeding values for meat quality traits of European quails fed different (methionine + cystine): lysine ratio diets from hatch to 21 days of age, using reaction norm models. A total of 9011 meat quality records from 1400 progenies of 80 sires and 160 dams from two lines (LF1 and LF2) were used in the analyses considering homogeneity of residual variance. The quails from hatch to 21 days of age were fed diets containing 0.61, 0.66, 0.71, 0.76 and 0.81 (methionine + cystine): lysine ratios, 26.12% of crude protein and 2900 ME/kcal of diet. From 22 to 35 days of age all quail were fed a diet containing 22% of crude protein and 3050 kcal ME/kg of diet. The random regression model analyses was performed using the WOMBAT program considering homogeneity of residual variance. Genetic variance and heritability estimates were affected by the environment gradient of diet and line, increasing these estimates with the increase of the (methionine + cystine): lysine ratio of the diet. The breeding values changed with the increase of the environment gradient of the diet with changes in the rank of genetic breeding values characterizing the existence of genotype by environment interaction for meat quality traits. Predictions of meat quality trait breeding values based on a given (methionine + cystine): lysine ratio are not valid for other levels of the amino acid ratio.

RESUMOObjetivou-se com o presente trabalho ajustar modelos não lineares para descrever o padrão de crescimento de genótipos de codornas de corte e de postura do nascimento aos 35 dias de idade. Foram utilizados dados de 1280 codornas machos e fêmeas, provenientes de sete genótipos de codornas de corte (EV1, EV2, UFV1, UFV2, UFV3, LF1, LF2) e um de postura. Todas as codornas foram pesadas a cada sete dias, do nascimento aos 35 dias de idade. Foram ajustados os modelos Brody, Gompertz, Logístico, Richards e von Bertalanffy aos dados de peso corporal de todos os genótipos. As análises estatísticas foram realizadas utilizando-se o PROC NLIN do SAS (Statistical Analysis System, versão 9.0). Os critérios empregados para a escolha do melhor modelo para descrever a curva de crescimento foram o coeficiente de determinação ajustado (R2), o desvio padrão assintótico (DPA), o desvio médio absoluto dos resíduos (DMA), o índice assintótico (IA), o critério de informação bayesiano (BIC), o critério de Akaike (AIC) e o quadrado médio do erro (QME). Todos os modelos não lineares testados convergiram, com exceção do modelo Brody, que não convergiu para nenhum genótipo avaliado. O modelo Richards não convergiu para o genótipo postura. Os parâmetros da curva de crescimento estimados pelos modelos indicaram maior precocidade, em geral, do genótipo postura comparado aos demais genótipos. O modelo Richards apresentou superestimação do ponto de inflexão para todos os genótipos, exceto para o genótipo postura. Os modelos Gompertz, Logístico e von Bertalanffy são recomendados para descrever o crescimento de codornas de corte dos grupos genéticos em estudo. O modelo Brody não convergiu, por isso não é recomendado para descrever o crescimento dos grupos genéticos de codornas em estudo.

ABSTRACTThis work aimed to adjust nonlinear models to describe the growth pattern of meat type and posture quail genotypes from hatch to 35 days of age. A total of 1280 male and female quails from EV1, EV2, UFV1, UFV2, UFV3, LF1 and LF2 and Posture genotypes were weighed every seven days, from hatch to 35 days of age. Brody, Gompertz, Logistic, von Bertalanffy and Richards models were used to fit the growth of the genetic groups. Statistical analyses were performed using PROC NLIN of SAS (Statistical Analysis System, version 9.0). The criteria used to select the model showing the best goodness of fit to the growth of the genotypes were: Adjusted Coefficient of Determination (R2), Asymptotic Standard Deviation (DPA), Absolut Mean Deviation (DMA), Asymptotic Index (AI), Bayesian Information Criterion (BIC), Akaike Information Criterion (AIC) and Errors Mean Square (MSE). All nonlinear models converged for the studied genotypes, except Richard the model for the Posture genotype. In general, the estimated parameters for the growth curve using nonlinear models suggested higher precocity for the Posture genotype in comparison to meat type genotypes. The Richard model overestimates the inflection point for all genotypes, except for the Posture genotype. The Gompertz, Logistic and von Bertalanffy are recommended to describe the growth patterns of the studied quail genetic groups. The Brody model did not converge and is not recommended to describe the genetic growth of the studied groups.

As porcelanas aluminosas são utilizadas como materiais de isoladores elétricos de alta tensão. Este tipo de porcelana se caracteriza por apresentar excelentes propriedades físicas, mecânicas e elétricas. As porcelanas aluminosas são fabricadas usando-se formulação de massa do tipo composta contendo caulim, argila plástica, feldspato e alumina. Na literatura é encontrada uma larga faixa de composições para essas porcelanas. Por outro lado, o setor de rochas ornamentais gera enormes quantidades de resíduos sólidos ricos em compostos fundentes, que podem ser usados como matéria-prima alternativa na fabricação de porcelanas. Neste trabalho foi estudada porcelana elétrica aluminosa incorporada com até 35 % em peso de resíduo de rocha ornamental em substituição do feldspato sódico, que é uma matéria-prima natural. As massas cerâmicas foram preparadas pelo processo via seca. Peças de porcelanas aluminosa em forma de disco foram preparadas por prensagem uniaxial a 50 MPa. As amostras foram sinterizadas em forno tubular a 1350 ºC por 1h. As seguintes propriedades tecnológicas foram avaliadas: retração linear, absorção de água, massa específica aparente, porosidade aparente, resistência à compressão e resistividade elétrica. A microestrutura sinterizada foi acompanhada por microscopia eletrônica de varredura e difração de raios X. Os resultados experimentais mostram que o resíduo de rocha ornamental pode substituir em até 10 % em peso o feldspato sódico na formulação de porcelana aluminosa. A microestrutura sinterizada foi fortemente influenciada pela adição do resíduo de rocha ornamental.

Aluminous porcelains are used as materials for high voltage electrical insulation. This type of porcelain is characterized by their excellent physical, mechanical and electrical properties. Aluminous porcelains are manufactured using compound body formulation containing kaolin, plastic clay, feldspar and alumina. A wide range of compositions is found in the literature for these porcelains. On the other hand, the ornamental rock sector generates huge amounts of solid wastes rich in flux materials, which can be used as an alternative raw material in the manufacture of porcelains. The present work studied aluminous electrical porcelain with up to 35 wt.% of ornamental rock waste in replacement of sodium feldspar, which is a natural raw material. The ceramic pastes were prepared by the dry process. Pieces of disc-shaped aluminous porcelain were prepared by uniaxial pressing with 50 MPa. The samples were sintered in a tubular furnace at 1350 °C for 1h. The following technological properties were evaluated: linear shrinkage, water absorption, bulk density, apparent porosity, compressive strength and electrical resistivity. The sintered microstructure was analyzed by scanning electron microscopy and X-ray diffraction. Experimental results show that ornamental rock waste can replace up to 10 % of sodium feldspar in the formulation of aluminous porcelain. The sintered microstructure was strongly influenced by the addition of ornamental rock waste.

Filtration through membranes is a process largely employed in the food and chemical industry to separate particles. Sieves present some advantages in relation to conventional membranes such as high homogeneity in the pore sizes, smooth surfaces, straight-through pores, etc. In this paper we compare the selectivity in the exclusion of particles by size of sieves with circular and slit pores with the same porosity. The selectivity was investigated by filtering a mixture of rutin in water in a cross-flow filtration system. The particle-size distribution of the rutin solution was measured before and after microfiltration. The results showed a high efficiency in the size exclusion of particles for microsieves with circular pores. The filtration through a commercial membrane (net filter) with similar characteristics was also characterized for comparison.

Drying of foodstuffs is used to improve product stability, but presents some potentially harmful side effects such as shrinkage. The reduction of the relative humidity of the environment was studied in this work to substitute heating during drying, also taking into account the effect on shrinkage. Drying experiments of cylindrical slices of banana were conducted in commercial equipment, with controlled temperature and relative humidity. The samples of banana, with diameter/thickness aspect ratio of approximately five, were used. Results showed the existence of a constant drying flux period is when the variation of the transfer area is taken into account, which is evidence that the shrinking is two-dimensional. Relative humidity, and not only temperature, influences the final characteristics of the product. With this, an equivalence project of drying rates is considered in different conditions for the optimization of energy costs and product quality.

Pyrolysis gasoline - PYGAS - is an intermediate boiling product of naphtha steam cracking with a high octane number and high aromatic/unsaturated contents. Due to stabilization concerns, PYGAS must be hydrotreated in two stages. The first stage uses a mild trickle-bed conversion for removing extremely reactive species (styrene, dienes and olefins) prior to the more severe second stage where sulfured and remaining olefins are hydrogenated in gas phase. This work addresses the reaction network and two-phase kinetic model for the first stage of PYGAS upgrading. Nonlinear estimation was used for model tuning with kinetic data obtained in bench-scale trickle-bed hydrogenation with a commercial Pd/Al2O3 catalyst. On-line sampling experiments were designed to study the influence of variables - temperature and spatial velocity - on the conversion of styrene, dienes and olefins.