ABSTRACT Several aspects make nitrocellulose based powders adequate as a solid propellant for rockets and missiles and the prefe rable propellant to be used in firearms and artillery: it produces less smoke and less fouling than other propellants; its burning rate shows a well-defined relation to pressure and the composition of the gaseous mixture resulting from its decomposition by burning can be predicted with relatively high levels of accuracy. This last feature, if coupled with adequate thermodynamic models, leads to a reliable framework for the simulation of internal ballistics and, ultimately, to an efficient design. Some simpler models use an ideal gas approach, which is obviously not adequate, and some others perform corrections based on the Virial E quation of S tate for sake of algebraic simplicity. This work employs the Peng-Robinson equation of state to model the pressure-volume-temperature (PVT) behavior of the gases produced during the burning reaction, once it is known to be accurate in the high pressures obtained inside combustion chambers. The results were compared to experimental data obtained in a closed vessel device and showed that the Peng-Robinson equation of state could predict the chamber pressure with higher accuracy. artillery propellants welldefined well defined accuracy feature ultimately design approach simplicity PengRobinson Peng Robinson pressurevolumetemperature volume temperature PVT (PVT reaction chambers

Abstract The improvement of sandy soils by incorporating new stabilizing agents in a physical and/or chemical process has become the subject of many studies in recent decades. In addition, the use of industrial wastes in this process can bring significant benefits to the environment and savings in natural resources. This work aims to evaluate the implications of incorporating porcelain polishing waste (PPW) and hydrated lime on the mechanical properties of an aeolian dune sand from the city of Natal/RN. Tests of unconfined compressive strength and split tensile strength were performed on compacted soil specimens with different contents of PPW (10%, 20% and 30%), hydrated lime (3%, 5% and 7%) and relative densities (25%, 50% and 75%). To evaluate the effects of each factor, the Response Surface Methodology with Central Composite Design was used. The results have shown that all three factors have a positive effect on the response variables. The highest strengths were obtained in regions combining high values of relative density and PPW content and an optimum lime content was found. An inversely proportional correlation and good fit to the experimental data was obtained between the strength values and the porosity/binder index ( η / B i v). The strength gains were attributed to densification of the soil structure and cementation of the particles by the compounds formed in the reaction between lime and PPW. The results also showed an increase in the strength with curing time, indicating a pozzolanic activity of the mixtures.

RESUMO A geração de resíduos industriais tem aumentado continuamente motivando estudos sobre uma destinação ambientalmente correta e sustentável. Como exemplo existem os resíduos gerados em fábricas de produtos de limpeza. Com o intuito de avaliar o potencial de incorporação de lodo de uma indústria deste setor como filer para a fabricação de concretos convencionais, foram adicionados diferentes teores de lodo (5, 10, 15 e 20%) em um traço 1:2:3 (cimento:areia:brita). Foram avaliadas as propriedades mecânicas e de durabilidade destes concretos nos estados fresco e endurecido. Todos os concretos produzidos com o resíduo apresentaram aumento de trabalhabilidade atribuído à possível presença de surfactantes na composição dos efluentes. Entretanto, foram obtidas resistências à compressão inferiores ao concreto referência com evidências de um aumento na porosidade da zona de transição e maior formação do composto etringita na microestrutura. Para o máximo teor de adição, a redução na resistência foi cerca de 39%. A absorção de água e índice de vazios aumentaram levemente para todos as misturas, com exceção do concreto com 20% de lodo. A adição do resíduo na matriz cimentícia provocou uma redução na durabilidade. Como avaliação final, o teor máximo de adição recomendado é de 20%, constituindo uma proporção significativa para destinação do resíduo, entretanto, os concretos produzidos não podem ser utilizados para fins estruturais.

ABSTRACT The generation of industrial waste has increased continuously encouraging studies about a sustainable and environmentally correct destination to it. As an example, there are the waste generated in cleaning product factories. Aiming to evaluate the incorporation potential of a sludge from an industry of this sector as filler for conventional concretes production, different sludge content was added (5, 10, 15, 20%) in a proportion 1:2:3 (cement:sand:gravel). The mechanical and durability properties of these concretes were evaluated in the fresh and hardened states. All concretes produced with residue showed an increase of workability attributed to the possible presence of surfactants in the composition of effluents. However, compressive strengths lower than the reference concrete were obtained with evidence of an increase in the porosity of the transition zone and greater formation of the compound ettringite in microstructure. For maximum addition content, the reduction in resistance was about 39%. The water absorption and void ratio have slightly increased for all the mixtures, except concrete with 20% sludge. The addition of the residue in the cementitious matrix caused a reduction in durability. As a final evaluation, the maximum addition content recommended is 20%, constituting a significant proportion for waste disposal, however, the produced concretes cannot be used for structural purposes.

Objetivou-se, neste trabalho, prolongar a vida pós-colheita de morangos, submetidos à atmosfera modificada ativa (2% O2 + 10% CO2 e 5% O2 + 5% CO2) e armazenados sob refrigeração (9 ± 1ºC e 99% UR) por 10 dias. O experimento foi realizado no DCA/Ufla, em Lavras, MG. Diante dos resultados obtidos neste trabalho, pôde-se concluir que os morangos não sofreram influência da atmosfera modificada em relação aos frutos- controle, quanto aos parâmetros avaliados.

The goal of this work was to draw out the shelf-life of strawberries, submitted to the active modified atmosphere (2% O2 + 10% CO2 and 5% O2 + 5% CO2) and stored under refrigeration (9 ± 1ºC and 99% UR) by 10 days. The experiment was carried through in the DCA/Ufla, in Lavras, MG. With the results gotten in this work, it may be concluded that the strawberries did not suffer any influence of the modified atmosphere in relation to the controlled fruits, according to the evaluated parameters.

Objetivou-se avaliar a ação do cloreto de cálcio na doçura pós-colheita de uvas 'Red Globe' (Vitis vinifera L) cultivadas em Jales, noroeste do Estado de São Paulo, foram adotados os procedimentos: os cachos foram tratados por imersão durante 10 minutos em soluções CaCl2 0, 1, 2 e 3% e deixados por 30, 60 e 90 dias a uma temperatura de 0ºC a 3ºC, 90+ 3% de UR e 0,2 0,3 m/s de velocidade do ar, após os quais foram deixados em temperatura ambiente (20 a 25ºC), para avaliações aos 0, 3 e 6 dias. O delineamento experimental foi inteiramente casualizado em esquema fatorial 4 x 3 x 3 (concentrações de CaCl2 x tempo de armazenamento refrigerado x tempo de armazenamento em temperatura ambiente) com três repetições. Foram feitas avaliações de açúcares redutores totais (g 100g -1), frutose (g 100g -1) e glicose (g 100g -1). Os teores de açúcares redutores totais, frutose e glicose dos frutos variaram com a aplicação de CaCl2, tempos de armazenamento a frio e em temperatura ambiente. Destaca-se a frutose cujos teores em todas as concentrações de CaCl2 (1, 2 e 3%), aos 30 e 60 dias de armazenamento refrigerado e 3 e 6 dias em temperatura ambiente, foram superiores aos teores dos frutos controle. Conclui-se que tratamentos com CaCl2 propicia às uvas melhor sabor, sendo indicada a concentração de CaCl2 2% e o armazenamento a frio por 60 dias e em temperatura ambiente até seis dias.

This work was carried out with the aim of evaluating the calcium chloride influence on both post harvest sweetness of grapes 'Red Globe' (Vitis vinifera L) grown in Jales, in the northwest of São Paulo State. The procedures adopted were as follows: banches were treated in a CaCla2 1%, 2%, and 3% immersion for 10 minutes and then left at na 0º C tempereture, 90 + 3% relative humidity, and 0,2-0,3 m/s air speed for 30, 60, and 90 days after which they were left at room temperature (20 to 25º C) for evaluation. A ramdomized block design with a 4 x 3 x 3 (CaCl2 concentration x cold storage x room storage) factorial arrangement and three replications was used. Total reductor sugars (g 100g -1), fructosis (g 100g-1), and glicosis (g 100g-1) were evaluated. CaCl2 treatments as well as storage time at both cold and room temperature were found to cause total reductor sugars, fructosis, and glicosis content in the fruits to vary/differ/be at variance degree. Fructosis (outstanding) contents were found to be higher than those in the control fruits in all CaCl2 concentrations after both 30 and 60 storage days at cold temperature, and 3 and 6 days at room temperature. Conclusion can be made that CaCl2 treatments promote better flavour to grapes. The CaCl2 2% concentration, the cold storage for 60 days, and the room storage for up to 6 days should be used.

Conduziu-se o presente trabalho para estudar o efeito de diferentes sanificantes, na conservação pós-colheita de morangos, armazenados sob refrigeração (9± 1ºC e 99% UR), por um período de 12 dias. O delineamento experimental utilizado foi inteiramente casualizado, com 3 repetições, constituindo dos seguintes tratamentos: T1) Controle, imersão em água destilada, 15 min, T2) imersão em solução de dicloro s. triazinatriona sódica dihidratada (Sumaveg®) a 200 ppm, por 15 min; T3) imersão em solução de peróxido de hidrogênio 10%, por 15 min; T4) imersão em solução de dicloro isocianurato de sódio (Hidrosan®) a 200 ppm, por 15 min. As análises de pH, SS, AT, Cor L*a*b e microbiológicas foram realizadas a cada 3 dias. Os processos de sanificação adotados foram eficientes para manter a qualidade de morangos minimamente processados por 12 dias de armazenamento. Verificou-se, no presente trabalho, que o uso de sanificantes foi de fundamental importância para manter baixas as contagens de fungos filamentosos e leveduras dos morangos minimamente processados.

The aim of this work was to study the effect of different sanitizing in the conservation postharvest of strawberry, stored in 9ºC and 99% R.H. for 12 days. The experiment was conducted in completely randomized design, with three replicates, the treatments constituted by: T1) Control, immersion in distilled water; T2) immersion in solution of dychlorine s. triazinatriona sodiumdehydrated (Sumaveg®) at 200 ppm, for 15 min; T3) immersion in solution of hydrogen peroxide 10%, for 15 min; T4) immersion in solution of dychlorine isocianurate of sodium (Hidrosan®) 200 ppm, for 15 min. The analyses of pH, SS (soluble solids), TA (titrable acidity), Color L*a*b and microbiological was evaluated in 0, 3, 6, 9 and 12 days. The process of sanitizing was efficient to maintain the quality of strawberry minimally processed for 12 days. The use of sanitizing was of fundamental importance to maintain low containing of microorganisms of the group mold and yeasts.

O objetivo deste trabalho foi investigar a influência do 1-metilciclopropeno (1-MCP) nas atividades das enzimas hidrolíticas da parede celular e nas mudanças na degradação da pectina durante o amadurecimento de sapoti (Manilkara zapota cv. Itapirema 31). Frutos de sapotizeiro foram tratados com o inibidor da ação do etileno, 1-MCP, na concentração de 300 nL L-1, por 12 horas e armazenados sob atmosfera modificada, à temperatura de 25± 2º C, por 23 dias. A firmeza, conteúdo de pectina total e solúvel e enzimas da parede celular foram avaliados durante todo o período de armazenamento. O 1-MCP a 300 nL L-1 por 12 horas retardou significativamente o amolecimento de sapoti por 11 dias a 25º C. O tratamento com 1-MCP afetou a atividade das enzimas pectinametilesterase e poligalacturonase e inibiu o aumento da atividade beta-galactosidase por 8 dias, e, conseqüentemente, resultou em menor solubilização das substâncias pécticas. A beta-galactosidase parece ser relevante no amolecimento de sapoti e responsável pela modificação das pectinas e das xiloglucanas ligadas as microfibrilas de celulose.

The objective of this work was to investigate the influence of 1-methylcyclopropene (1-MCP) at 300 nL L-1 on activities of cell wall hidrolytic enzymes and pectin breakdown changes which Sapodilla (Manilkara zapota cv. Itapirema 31) cell wall undergoes during ripening. Sapodilla were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 hours and then, stored under a modified atmosphere at 25º C for 23 days. Firmness, total and soluble pectin and cell wall enzymes were monitored during storage. 1-MCP at 300 nL L-1 for 12 hours delayed significantly softening of sapodilla for 11 days at 25º C. 1-MCP postharvest treatment affected the activities of cell wall degrading enzymes pectinmethylesterase and polygalacturonase and completely suppressed increases in beta-galactosidase for 8 days, resulting in less pectin solubilization. Beta-galactosidase seems relevant to softening of sapodilla and is probably responsible for modification of both pectin and xyloglucan-cellulose microfibril network.

Com o presente trabalho objetivou-se avaliar a qualidade e a vida útil do pepino (Cucumis sativus L.), utilizando recobrimento com película de fécula de mandioca. Após seleção, amostras de pepino japonês foram mergulhadas em suspensões de fécula de mandioca a 0, 2, 3 e 4%, secos ao ar e armazenados em câmara fria a 5ºC e 95% de UR por 8 dias. As análises realizadas foram perda de massa, pH, sólidos solúveis (SS) , acidez titulável (AT), Cor L*a*b e firmeza. O delineamento utilizado foi o DIC com 3 repetições, com os tratamentos dispostos em esquema fatorial 4 x 5. O valor encontrado para firmeza nas amostras tratadas com película a 4% foram menores em comparação aos outros tratamentos, isto, provavelmente se deve à plasticidade do tecido que estas amostras apresentaram. A película reduziu significativamente a perda de massa das amostras mantidas sob refrigeração. A aplicação de película de fécula de mandioca na concentração mais elevada (4%), proporcionou ao pepino um aspecto melhor de conservação, tornando o produto mais atraente.

This work was made to evaluate the properties and postharvest life of cucumber (Cucumis sativus L.) coated with cassava starch film. After the selection the fruits were dipped in suspensions 0, 2, 3 and 4% starch, dried naturally and stored in chamber cold (5ºC ± 1ºC and 90% ± 5% HR) during 8 days and the analyses were done in the time zero and in intervals of 2 days. The analyses done were loss mass, titratable acidity (TA), pH, soluble solids (SS), color L*a*b and firmness. The test was conducted in completely randomized design, with three repetitions, with the treatments disposed in factory layout 4x5. The value found for firmness in the samples treated with biofilm at 4% was smaller in comparison to the other treatments, this, is probably due to the plasticity of the tissue that these samples presented. The film reduced the loss of mass of the samples maintained under refrigeration significantly. The application cassava starch film in the highest concentration (4%), provided to the cucumber a better aspect of conservation, turning the most attractive product.