The development of an eco-friendly material that could reduce CO² emission and that could aggregate value to a natural fiber, setting man at the countryside and raising the income of populations from poor regions is a challenge. Lignocellulosic fibers are cheap and are a readily available reinforcement, requiring only a low degree of industrialization for their processing. The main drawback of using cement composites reinforced with lignocellulosic fibers is that the fibers can be mineralized inside the alkaline environment. In this work, Portland cement was partially replaced by metakaolinite in order to produce a matrix free from calcium hydroxide, avoiding thus the problem of fiber mineralization. Cement composites reinforced with 2, 4 and 6% of short curaua fibers, were manufactured. The composites were submitted to four pointing bending tests in order to determine their mechanical behavior. The results obtained were compared with those found for cement composites reinforced with sisal fibers.

Digital Microscopy was employed to characterize the microstructure of fiber-reinforced composite tubes manufactured by filament winding. Optical Microscopy was used for void characterization while Scanning Electron Microscopy was used for fiber and layer analysis. Acquired images were assembled in mosaics to reveal the microstructure of different cross-sections of the sample. Image processing was employed to detect either voids or individual fibers and measure their size, shape and spatial distribution. Void spatial distribution was analyzed with two different methods - local analysis and the tessellation method - revealing different behaviors along different cross-sections. Fiber layers were automatically detected and their average winding angle and dispersion were analyzed.

Os principais objetivos deste trabalho foram o estudo da diversidade dos dípteros das famílias Calliphoridae, Fanniidae, Muscidae e Sarcophagidae em um fragmento de Mata Atlântica localizado na Ilha do Governador, Rio de Janeiro, Brasil, entre julho de 2001 e julho de 2002. Foi também analisada ocorrência das espécies mais freqüentes das famílias estudadas de acordo com a variação temporal na área do fragmento. As coletas foram feitas com armadilhas, utilizando iscas de peixe em decomposição. A espécie mais freqüente e constante foi Chrysomya megacephala (Fabricius, 1794) que é exótica e foi introduzida há pouco mais de vinte anos no continente americano.

This paper aimed to study the diversity of dipterans of the families Calliphoridae, Fanniidae, Muscidae and Sarcophagidae in a fragment of the Atlantic rainforest located in the Ilha do Governador, Rio de Janeiro State, Brazil, from July 2001 to July 2002. The temporal variation occurrence of the most frequent species of the studied families in the fragment was also analyzed. The collections were performed with traps using baits of rotten fish. The most frequent and most constant species was Chrysomya megacephala (Fabricius, 1794) which is exotic and was introduced about twenty years ago in the American Continent.

Objective: To test the hypothesis that overweight adolescents have higher plasma total homocysteine (tHcy) levels than non-overweight adolescents and to explore the association between plasma tHcy levels with folate, vitamin B12 and some risk factors for CVD in both groups. Methods: A case-control study conductec with 239 adolescentes aged 15-19 years in the city of São Paulo, Brazil; 86 overweight and 153 non-overweight frequency matched by age, gender, pubertal and socioeconomic status. tHcy, folate, vitamin B12, lipid profile, glucose, insulin and insulin resistance were measured. Results: No significant differences were found in tHcy, folate and vitamin B12 levels between overweight and non-overweight groups. The geometric means of tHcy were elevated in both groups (overweight: 11.8 µmol/L; non-overweight: 11.6 µmol/L) higher for boys than for girls (P ≤ 0.001). Folate deficiency was identified in 68.6% of total studied population. Triacylglycerol, LDL cholesterol, insulin resistance were higher and HDL cholesterol was lower in overweight that non-overweight adolescents. In the multiple linear regression model, in overweight group, tHcy was independently associated with age (P = 0.041), sex (P = 0.004) and folate (P = 0.022) and in non-overweight group, with age (P = 0.049), sex (P < 0.001), folate (P = 0.018) and vitamin B12 (P = 0.030). Conclusions: Obesity was not a determinant factor of tHcy levels. Age, sex and folate were independent determinants of plasma tHcy levels. The high prevalence of folate deficiency may have been responsible for the elevated tHcy levels in these adolescents, increasing the risk for future development of CVD.

Objetivo: Probar la hipótesis de que los adolescentes con sobrepeso tienen mayores concentraciones plasmáticas de homocisteína total (tHcy) que los adolescentes sin sobrepeso, y explorar la asociación entre las concentraciones plasmáticas de tHcy con folato, vitamina B12 y algunos factores de riesgo de ECV en ambos grupos. Métodos: Estudio de casos-control realizado en 239 adolescentes de edades entre los 15-19 años, de la ciudad de Sao Paulo, Brasil; 86 tenían sobrepeso y 153 no, emparejados por edad, sexo, estado puberal y socioeconómico. Se midieron tHcy, folato, vitamina B12, perfil lipídico, glucosa, insulina y resistencia a insulina. Resultados: no se hallaron diferencias significativas en las concentraciones de tHcy, folato ni vitamina B12 entre los grupos con y sin sobrepeso. Las medias geométricas de tHcy estaban elevadas en ambos grupos (sobrepeso: 11,8 µmol/l; sin sobrepeso: 11,6 µmol/l), y fueron mayores en los chicos que las chicas (P ≤ 0,001). Se identificó la deficiencia de folatos en el 68,6% de la población total estudiada. El triacilglicerol, el colesterol-LDL y la resistencia a insulina fueron mayores en el grupo de adolescentes con sobrepeso, y el colesterolHDL fue superior en el grupo sin sobrepeso. En el modelo de regresión linear múltiple, en el grupo con sobrepeso, la tHcy se asoció, de forma independiente, con la edad (P = 0,041), el sexo (P = 0,004) y el folato (P = 0,022) y, en el grupo sin sobrepeso, con la edad (P = 0,049), el sexo (P < 0,001), el folato (P = 0,018) y la vitamina B12 (P = 0,030). Conclusiones: la obesidad no fue un factor determinante de las concentraciones de tHcy. La edad, el sexo y el folato fueron determinantes independientes de las concentraciones plasmáticas de tHcy. La prevalencia elevada de deficiencia de folato podría haber sido responsable de las concentraciones elevadas de tHcy en estos adolescentes, aumentando el riesgo de desarrollo futuro de ECV.

The influence of the fiber used as reinforcement in resin matrix composite materials submitted to repeated low energy impacts is analyzed. The aramid, glass and carbon fiber composites were submitted to drop weight tests from 0.5m and from 1m. The number of impact events necessary to cause failure was recorded, and the fracture characteristics of each composite were analyzed by optical microscopy and X-rays radiography. The results obtained showed that carbon fiber composites have better performance than the glass and aramid composites. This behavior was partially attributed to the higher elastic energy absorption of carbon fibers that delays the propagation of delamination, and fiber breakage. The failure mode of glass fiber composites was dominated by the higher number of glass fibers per surface area of the composites. The worst behavior shown by aramid composites was attributed to the intrinsic anisotropy of aramid fibers.

Vinte e sete espécies de dípteros caliptrados (Muscidae e Sarcophagidae) foram capturados no período de dezembro de 1993 a novembro de 1994, com armadilhas orientadas pelo vento (W.O.T.) contendo isca de fígado em putrefação, no jardim zoológico da cidade do Rio de Janeiro. As espécies capturadas em maior abundância foram Musca domestica (57,84%), Peckia chrysostoma (28,16%), Ophyra aenescens (17,11%), Oxysarcodexia thornax (17,82%), Synthesiomyia nudiseta (13,05%) e Oxysarcodexia diana (14,52%).

Twenty-seven species of calyptrate muscoids (Muscidae and Sarcophagidae) were collected from December 1993 to November 1994 with wind oriented traps (W.O.T.) baited with decomposing beef liver at the Rio de Janeiro Zoo. The most abundant species found were Musca domestica (57.84%), Peckia chrysostoma (28.16%), Ophyra aenescens (17.11%), Oxysarcodexia thornax (17.82%), Synthesiomyia nudiseta (13.05%), and Oxysarcodexia diana (14.52%).

Estudou-se a aderência de um modelo determinístico de isotermas para avaliar a dinâmica populacional de Synthesiomyia nudiseta (Diptera, Muscidae). As formas lineares das equações obtidas para os experimentos nas diversas fases foram: para ovo: 1/D = -0,18 + 0,02 . T; larva: 1/D = - 0,028 + 0,01 . T; pupa: 1/D = -0,069 + 0,01 . T; e adulto: 1/D = -0,4178 + 0,02 . T. Em função da temperatura, S. nudiseta pode apresentar de 4,18 a 8,95 e de 4,91 a 8,99 gerações por ano, quando calculadas por meio das equações de desenvolvimento e pelas simulações, respectivamente. Sendo que, quanto mais alta a temperatura, maior o número de gerações. Por intermédio da análise de variância verificou-se a significância para as equações de regressão relativas ao número de gerações anuais (Ng/ano) de S. nudiseta em função das isotermas, para duas situações estudadas. Obteve-se uma significância de 0,1%. As equações de regressão obtidas para essas situações foram: Ng/ano = 5,4 + 0,5 . T e Ng/ano = 5,1 + 0,52 . T. O número de gerações de S. nudiseta varia linearmente com as isotermas. Além disso, o número de gerações anuais para cada isoterma não difere estatisticamente quando calculadas por meio das equações de desenvolvimento ou por meio das simulações. Tais condições sugerem a adequação do modelo determinístico adotado.

The isothermal deterministic model adherence was studied to evaluate the population dinamic of Synthesiomyia nudiseta (Diptera, Muscidae). The linear form of equation obtained for the experiments in the several phases, were for Egg: 1/D = -0.18 + 0.02 . T; Larva: 1/D = -0.028 + 0.01. T; Pupa: 1/D = -0.069 + 0.01 . T; and Adult: 1/D = -0.4178 + 0.02 . T. In function of temperature, S. nudiseta can present from 4.18 to 8.95 and from 4.91 to 8.99 generations per year, when calculated through the equations of development and through the simulations, respectively. And the higher the temperature the larger the generation number. Through variance analysis it was verified the significance for the regression equations in relation to the annual generation number (Ng/year) of S. nudiseta in function of the isothermals, for two studied situations. It was obtained a significance of 0,1%. The regression equations obtained for these situations were: Ng/year = 5.4 + 0.5 . T and Ng/year = 5.1 + 0.52 . T. The number of generations of S. nudiseta varies linearly with the isothermal. Besides that, the number of annual generations for each isothermal does not differ statistically when calculated through the development equations or through the simulations. Such conditions suggest the adaptation of the deterministic model adopted.

Neste trabalho o efeito da adição de 2 a 7% em peso de um copolímero tribloco estireno-b-etileno-co-butileno-b-estireno (SEBS) em uma blenda polipropileno/poliestireno de alto impacto (PP/HIPS) 70:30 foi determinado. As propriedades em tração e impacto, temperatura de amolecimento Vicat e morfologia da blenda PP/HIPS (70:30) em função da concentração de SEBS foram determinadas. As blendas foram processadas em extrusora dupla-rosca contra-rotativa interpenetrante e as amostras moldadas por compressão. Os resultados mostraram que, embora a adição do SEBS tenha promovido um aumento muito leve na resistência tênsil e no módulo elástico, observou-se um expressivo aumento no alongamento na ruptura e na resistência ao impacto das blendas; a temperatura Vicat das blendas foi superior à do HIPS e que a adição do SEBS promoveu uma redução significativa do tamanho de partícula, indicando que o SEBS exerceu um efeito emulsificante e estabilizador na morfologia das blendas investigadas. Resultados otimizados foram obtidos para a composição contendo 5% de SEBS, o que foi atribuido à uma maior compatibilidade entre as fases.

In this work the effect of a 2-7% w/w styrene-b-ethylene-co-butylene-b-styrene triblock copolymer (SEBS) addition on the properties of a 70:30 polypropylene/high impact polystyrene (PP/HIPS) polymer blend was investigated. Tensile and impact properties, the Vicat temperature and blend morphology were determined as a function of SEBS content. Processing was carried out in a twin-screw intermeshing counter-rotating extruder and the samples were compression moulded. Our results indicate that the SEBS addition, albeit promoting very slight increases on tensile strenght and modulus, led to increases on the elongation at break and impact strenght of the blends, and the Vicat temperature of the blends was higher than that of HIPS. The SEM analysis showed that SEBS addition promotes a significant reduction on particle size, which was taken as an indication that SEBS exerted an emulsifying and stabilizing effect on the morphology of the PP/HIPS blend under investigation. The best overall properties were obtained at 5 wt.% SEBS content.

Foram calculadas a extensão e sobreposição de nichos tróficos de dípteros caliptrados, criados em variados ambientes do Rio de Janeiro (área rural, urbana e florestal), utilizando-se diferentes substratos de criação (banana amassada, carcaça de camundongo, peixe (sardinha), fígado bovino, camarão e fezes humanas frescas. Foram criadas 14.294 moscas, pertencentes às famílias Calliphoridae, Fanniidae, Muscidae e Sarcophagidae. As maiores sobreposições de nichos tróficos, entre as espécies, foram assim constatadas: área rural: Phaenicia cuprina versus Chrysomya megacephala; área urbana: Phaenicia eximia versus Sarcodexia innota e P. eximia versus Synthesiomyia nudiseta; área florestal: P. eximia versus Hemilucilia flavifacies. Na área rural, o nicho mais extenso foi o de Peckia chrysostoma; na área urbana, o de S. nudiseta e Musca domestica. Euboettcheria collusor e P. eximia, na floresta, foram as espécies com nichos tróficos mais amplos.

Niche breadth and niche overlap of flies were estimated. The flies were breeding in different environments in Rio de Janeiro (rural, urban and forest). It were used as a larvae substrate: banana mashed, mouse carcass, fish (sardine), bovine liver, shrimp and fresh human faeces. It were bred 14,294 flies, belonging to four families: Calliphoridae, Fanniidae, Muscidae and Sarcophagidae. The greater niche overlap values observed were: rural area: Phaenicia cuprina versus Chrysomya megacephala; urban area: Phaenicia eximia versus Sarcodexia innota e P. eximia versus Synthesiomyia nudiseta; forest area: P. eximia versus Hemilucilia flavifacies. The greater niche breadth recorded were: rural area: Peckia chrysostoma; urban area: S. nudiseta and Musca domestica; forest area: Euboettcheria collusor and P. eximia.