Investigation of the use of wet ethanol in an HCCI engine using water injection and direct exhaust heat recovery

Wet ethanol is a renewable fuel that has great potential to reduce the energy cost of ethanol production and improve the life-cycle carbon footprint of ethanol. The use of wet ethanol in homogeneous charge compression ignition (HCCI) mode can achieve high efficiency with low emission levels. In this context, this study investigates the effects of water-in-ethanol concentration on the performance, emissions, and combustion characteristics of an HCCI engine using water injection and recirculation of all exhaust gasses from a diesel cylinder. Water injection was used to solve the problem that there is no direct method to adjust HCCI combustion. Results showed that water–ethanol blends with higher water content had lower heat release rates and combustion temperatures, which increased the combustion duration. The indicated efficiency deteriorated for ethanol–water blends with high water concentrations. However, the highest indicated efficiency was 39.3% for the blend with 20% water by vol. at 6.0 bar. CO and organic gas emissions tended to increase with late combustion and for blends with higher water content, reaching values of 78.0 and 68.2 g/kWh at 4.0 bar, respectively. On the other hand, the NOX emissions were low, reaching a maximum value of 0.93 g/kWh in the HCCI combustion

Synthesis, reactivity and catalytic properties of rhodium complexes of (R,R)-1-benzyl-3,4-dithioetherpyrrolidines

Complexes [Rh(cod)(degusR)]ClO4, where cod is 1,5-cyclooctadiene and degusR represents the homochiral dithioethers (R,R)-1-benzyl-3,4-bis(methylsulfanyl)pyrrolidine, (R,R)-1-benzyl-3,4-bis(isopropylsulfanyl)pyrrolidine and (R,R)-1-benzyl-3,4-bis(phenylsulfanyl)pyrrolidine were prepared and characterized. Their reactivity with CO and PPh3 was investigated. The complexes were assayed as catalysts in hydroformylation of styrene, hydrogenation of acrylic acids and hydroboration of styrene. Although these complexes containing dithioethers behave as catalytic precursors in hydroformylation reaction, the results suggest that mononuclear hydride rhodium carbonyl species is responsible for the catalytic activity. The cationic complexes are not active in the hydrogenation of acrylic acids in the conditions tested. These complexes are moderately active in the hydroboration of styrene with catecholborane, but their selectivities are not satisfactory.http://www.sciencedirect.com/science/article/B6TG5-3XWJKPH-8/1/2d47b8846a016e0aca3487986250181

IFN-<FONT FACE=Symbol>g</font> in human Chagas' disease: protection or pathology?

An apparently paradoxical role for IFN-<FONT FACE="Symbol">g</font> in human Chagas' disease was observed when studying the pattern of cytokine production by peripheral blood mononuclear cells (PBMC) obtained from two groups of chagasic patients after specific stimulation with Trypanosoma cruzi-derived antigens. The groups studied were 1) patients treated with benznidazole during the acute phase of Trypanosoma cruzi infection and 2) chronically infected untreated patients. In the treated group, higher levels of IFN-<FONT FACE="Symbol">g</font> were produced by PBMC from individuals cured after treatment when compared to non-cured patients. In contrast, in the chronically infected group (not treated) higher levels of IFN-<FONT FACE="Symbol">g</font> were produced by PBMC from cardiac patients in comparison with asymptomatic (indeterminate) patients. This apparently paradoxical role for IFN-<FONT FACE="Symbol">g</font> in human Chagas' disease is discussed in terms of the possibility of a temporal difference in IFN-<FONT FACE="Symbol">g</font> production during the initial stages of the infection (acute phase) in the presence or absence of chemotherapy. The maintenance of an immune response with high levels of IFN-<FONT FACE="Symbol">g</font> production during the chronic phase of the infection may favor cure or influence the development of the cardiac form of the diseas

Relação entre heterogeneidade ambiental e distribuição de espécies em uma floresta paludosa no Município de Cristais Paulista, SP, Brasil Floristic composition and relationship between environmental heterogeneity and species distribution in a swamp forest from Cristais Paulista, São Paulo State, Brazil

Neste estudo foi caracterizada a composição florística e fitossociológica de uma floresta paludosa no nordeste do Estado de São Paulo, onde variações no padrão de drenagem ocorrem principalmente no sentido perpendicular ao curso d'água, em função da topografia. Nosso objetivo foi investigar a distribuição das espécies em relação ao substrato e a entrada de luz na comunidade. Foram alocadas 60 parcelas de 10×10 m, distribuídas em seis grupos de 10 parcelas cada. Em cada parcela foram medidos e identificados os indivíduos com PAP > 10 cm, avaliadas as propriedades químicas e granulometria do solo, o desnível topográfico, a drenagem e a abertura do dossel. Foram registradas 88 espécies, das quais 61 foram observadas nas parcelas. Uma análise de correspondência canônica (CCA) indicou correlações entre a distribuição das 29 espécies mais abundantes e drenagem, desnível topográfico e Fe no eixo 1 e abertura do dossel no eixo 2. O coeficiente de Spearman indicou correlações significativas entre 66% das 29 espécies e profundidade do lençol freático ou abertura do dossel. Como exemplo, Calophyllum brasiliense e Xylopia emarginata prevaleceram em solos mal drenados; Siphoneugena densiflora e Virola sebifera em solos bem drenados; Myrcia laruotteana e Xylopia sericea em parcelas com maior abertura de dossel. A heterogeneidade ambiental foi um importante fator na determinação da distribuição e a coexistência de espécies, resultando em um incremento na diversidade local.<br>In the present study, we characterized the floristic composition and tree structure of a swamp forest in northeast of São Paulo State, Brazil, where the drainage pattern changes mainly across the watercourse due to the topography. We aimed to investigate the species distribution in relation to substrate and light entrance in the community. Sixty quadrats (10×10 m) were divided into six groups of 10 plots. In each quadrat, individuals with PBH > 10 cm were measured and identified. We also evaluated soil chemical properties, granulometry, topographic unevenness, drainage, and canopy openness. Eighty-eight species were recorded, from which 61 were detected in the quadrats. Canonical correspondence analysis (CCA) indicated correlations between the distribution of the 29 most abundant species and drainage, topographic unevenness and Fe in the axis 1, and canopy openness in the axis 2. Spearman's rank correlation coefficient indicated significant correlations between 66% from the 29 species and water table depth or canopy openness. As examples, Calophyllum brasiliense and Xylopia emarginata were predominant in poorly-drained soils; Siphoneugena densiflora and Virola sebifera, in the drained ones; and Myrcia laruotteana and Xylopia sericea, in the quadrats presenting higher canopy openness. Environmental heterogeneity showed to be an important factor in determining the species distribution and coexistence, which increases local diversity