Small scale ethanol production process faces a number of challenges that negatively impact productivity and economic costs. The present work aims at finding alternative materials with lower cost and suitable resistance to replace the stainless steel commonly used in distillation columns in small scale businesses. For that we analyzed the chemical and mechanical behavior of nine different polymeric materials. An important parameter to consider in this case is the compatibility of polymer with the ethanol, which was determined according to the ASTM D543, as well as the swelling degree and ethanol diffusion in material being also studied in this work. Three-point flexural tests were performed because the material when in service is subjected to forces or loads. The results show that some of the materials under test present chemical resistance and satisfactory mechanic performance after the contact with the ethanol in temperatures compatible with the distillation process.

Este estudio evaluó experimentalmente el comportamiento de una columna de destilación de etanol/agua a pequeña escala. Se realizó análisis estadístico utilizando el software Statistica® 7,0, considerando un nivel de significación del 90% (p < 0,10), para evaluar si las variables independientes (concentración de etanol y caudal de alimentación) influencian la producción de etanol de acuerdo con la legislación brasileña, i.e., etanol combustible con concentración de etanol entre 92,5 y 93,8 % en masa. Los resultados demostraron que la influencia de la concentración de etanol y el caudal de alimentación fueron significativos para la concentración del producto destilado y la tasa de recuperación. La tasa de recuperación de etanol fue mayor que 80%, lo que señala que el rendimiento de la columna a pequeña escala fue satisfactorio.

This research assessed experimentally the performance of a small-scale ethanol/water distillation column. Statistical analysis was performed using Statistica® 7.0, considering a significance level of 90% (p < 0.10), to evaluate if the independent variables (feed stream ethanol concentration and flow rate) influence on the production of ethanol in accordance with the Brazilian legislation, i.e., a Hydrous Ethanol Fuel with ethanol content between 92.5 and 93.8 wt%. The results demonstrated that the influence of the feed stream ethanol concentration and flow rate were significant for both the top product concentration and the recovery ratio. The recovery ratio of ethanol was above 80%, demonstrating that the performance of the small-scale column is satisfactory.

A presente análise tem a finalidade de comparar o desempenho entre unidades e atividades produtivas, interligando os parâmetros energéticos aos econômicos. O objetivo deste trabalho foi analisar a relação entre a energia produzida e consumida durante o processo de produção das principais culturas de cereais do Estado do Rio Grande do Sul, a saber, trigo, arroz e soja, em contraposição aos resultados econômicos das respectivas atividades. A pesquisa foi do tipo exploratória, a partir de estudos de multicaso, com uso de pesquisa bibliográfica, análises de laboratório e entrevistas. Para determinar os resultados de análises energéticas, foram realizados os balanços energéticos e as eficiências culturais e energéticas das culturas. Para determinar os resultados econômicos das atividades estudadas, foi utilizada a Teoria do Valor Agregado. Os resultados demonstram que a atividade da soja, em sistema de plantio direto com rotação de culturas, alcançou a maior eficiência energética, entre 25,58MJ ha-1 a 38,39MJ ha-1, sendo que a relação de menor eficiência foi a cultura do trigo, com 3,13MJ ha-1. Em relação ao desempenho econômico das culturas, a soja igualmente mostrou a melhor eficiência econômica igual a 2,47 e a do trigo foi de 1,14 a menor. Cabe destacar os significativos resultados econômicos obtidos pela cultura do arroz, expressos pelo alto valor agregado, obtido por unidade de área (VAL/ha de R$ 3.802,00) em função de sua alta produtividade física. Apesar dos indicadores energéticos serem positivos, houve significativos gastos com fertilizantes, combustíveis e agrotóxicos em todas as propriedades estudadas. Dessa forma, reforça-se a importância do debate sobre a sustentabilidade socioambiental dos sistemas estudados, principalmente quando analisados sob a ótica dos gastos energéticos de bens não-renováveis e da problemática social atribuída à mão-de-obra.

The energy analysis aims to compare the performance between productive units and activities, searching an approach to link the energy with the economic. Objectives is the analysis of the energy produced and consumed during the production process of major crops in the state of Rio Grande do Sul, namely, rice, soybeans and wheat, opposed to the economic results of such activities. The research was exploratory and based on multi-case studies with the use of literature review, laboratory analysis and interviews. To determine the results of energy analyzes were performed energy audits and energy efficiencies and cultural crops, while for the economic results we used the theory of Earned Value. The results demonstrate that the activity of soybean in no-tillage system with crop rotation achieved the highest energy efficiency between 25.58MJ ha-1 and 38.39MJ ha-1, whereas wheat culture showed the lowest efficiency with 3.13MJ ha-1. Regarding the economic performance of crops, soybeans showed the highest economic efficiency 2.47 and wheat the lowest 1.14. It is worth mentioning the significant economic results achieved by the rice crop, expressed by the high added-value obtained per unit area (VAL/ha R$ 3,802.00) due to its high physical productivity. In spite of having positive energy indicators, significant expenses on fertilizer, fuel and pesticides were observed in all properties studied. Thus, we reinforce the importance of the debate on social and environmental sustainability of the systems studied, especially when analyzed from the perspective of energy expenses of non-renewable resources and social problems attributed to workforce.

The aim of this study was to evaluate the prevalence of caries-free children using DMFT and significant caries (SiC) indexes in different caries prevalence groups in cities of the region of Campinas, São Paulo State, Brazil. The methodology proposed by the World Health Organization (1997) was used for caries diagnosis in 2,378 individuals. According to the DMFT index obtained in each evaluated city, 3 prevalence groups with representative samples were formed, being classified as low, moderate and high. SiC index was used to classify the one third of the population with the highest caries prevalence. In the low prevalence group, 32.4% of the children were caries free (DMFT=0), with mean DMFT of 2.29 and SiC index of 4.93. In the moderate prevalence group, 21.8% of the children were caries free, with mean DMFT of 3.36 and SiC of 6.74. Only 6.9% of the children in the high prevalence group were caries free and the mean DMFT was 5.54 (SiC=9.62). There was a great heterogeneity in dental caries distribution within the studied population, as well as a high caries prevalence considering the 3 classifications. Other indexes besides DMFT could be used to improve oral health assessment during establishment of the treatment plan and intervention.

Currently, the accumulation of rice husk is a serious environmental problem. The burning of rice husk generates a considerable volume of ash, that falls to the ground and gets into the air and the rivers, causing a disequilibrium in the ecosystem. This motived research into solutions that aim to exploit the husks for energy generation and the ashes for developing diverse technological products. This work presents the possibilities of using rice husks and their ashes after burning.

O objetivo deste estudo foi verificar a relação entre tipo de escola, como medida de condição sócio-econômica e a prevalência de cárie em pré-escolares e escolares de Rio Claro, São Paulo, com água fluoretada. Os dados obtidos são secundários e a amostra foi de 888 escolares de 5 a 12 anos dos ensinos público e particular. A experiência de cárie foi medida por meio dos índices ceod e CPOD ¹, além do Índice de Cuidados. Empregou-se os testes qui-quadrado e Mann-Whitney com significância de 5%. Aos cinco anos, o ceod foi de 2,50 e 42,20% não apresentaram experiência de cárie. Aos 12 anos, o CPOD foi de 2,70 e 28,90% estavam livres de cárie. A prevalência de cárie nas crianças de escolas públicas foi maior do que nas particulares, sendo respectivamente de 74,50 e 61,20% (p < 0,0001), assim como os índices ceod e CPOD (p < 0,05). O Índice de Cuidados foi maior nas crianças do ensino particular (71,20%) do que nas do ensino público (52,80%). Encontrou-se uma maior experiência de cárie nos escolares do ensino público e assim a variável tipo de escola foi sensível para discriminar diferentes condições de saúde bucal, sugerindo-se que outras variáveis também sejam avaliadas.

The aim of this study was to verify the relationship between type of school as a measure of socioeconomic conditions and caries prevalence among preschoolers and schoolchildren in Rio Claro, São Paulo State, Brazil, a city with fluoridated water supply. The data were secondary, from a sample of 888 children 5 to 12 years old enrolled in private and public schools. Caries was measured by the dmft and DMFT indices as well as the Care index. Qui-square and Mann-Whitney tests were utilized with 5% significance. In 5-year-old children, mean dmft was 2.50, and 42.20% were caries-free. At age 12, mean DMFT was 2.70 and 28.90% were caries-free. Caries prevalence rates in public schoolchildren as compared to private were 74.50% and 61.20%, respectively (p < 0.0001), and the dmft and DMFT scores were the highest in public schoolchildren (p < 0.05). The Care Index was higher in private schoolchildren (71.20%) as compared to public (52.80%). Highest caries rates were found among public schoolchildren, so the variable type of school proved sensitive for discriminating different oral health conditions; however limitations need to be recognized, suggesting that other variables should be assessed.

O objetivo deste estudo foi verificar a relação entre tipo de escola, como medida de condição sócio-econômica e a prevalência de cárie em pré-escolares e escolares de Rio Claro, São Paulo, com água fluoretada. Os dados obtidos são secundários e a amostra foi de 888 escolares de 5 a 12 anos dos ensinos público e particular. A experiência de cárie foi medida por meio dos índices ceod e CPOD ¹, além do Índice de Cuidados. Empregou-se os testes qui-quadrado e Mann-Whitney com significância de 5%. Aos cinco anos, o ceod foi de 2,50 e 42,20% não apresentaram experiência de cárie. Aos 12 anos, o CPOD foi de 2,70 e 28,90% estavam livres de cárie. A prevalência de cárie nas crianças de escolas públicas foi maior do que nas particulares, sendo respectivamente de 74,50 e 61,20% (p < 0,0001), assim como os índices ceod e CPOD (p < 0,05). O Índice de Cuidados foi maior nas crianças do ensino particular (71,20%) do que nas do ensino público (52,80%). Encontrou-se uma maior experiência de cárie nos escolares do ensino público e assim a variável tipo de escola foi sensível para discriminar diferentes condições de saúde bucal, sugerindo-se que outras variáveis também sejam avaliadas.

The aim of this study was to verify the relationship between type of school as a measure of socioeconomic conditions and caries prevalence among preschoolers and schoolchildren in Rio Claro, São Paulo State, Brazil, a city with fluoridated water supply. The data were secondary, from a sample of 888 children 5 to 12 years old enrolled in private and public schools. Caries was measured by the dmft and DMFT indices as well as the Care index. Qui-square and Mann-Whitney tests were utilized with 5% significance. In 5-year-old children, mean dmft was 2.50, and 42.20% were caries-free. At age 12, mean DMFT was 2.70 and 28.90% were caries-free. Caries prevalence rates in public schoolchildren as compared to private were 74.50% and 61.20%, respectively (p < 0.0001), and the dmft and DMFT scores were the highest in public schoolchildren (p < 0.05). The Care Index was higher in private schoolchildren (71.20%) as compared to public (52.80%). Highest caries rates were found among public schoolchildren, so the variable type of school proved sensitive for discriminating different oral health conditions; however limitations need to be recognized, suggesting that other variables should be assessed.