988 resultados para Product State Distributions
Resumo:
Two methods were compared for determining the concentration of penetrative biomass during growth of Rhizopus oligosporus on an artificial solid substrate consisting of an inert gel and starch as the sole source of carbon and energy. The first method was based on the use of a hand microtome to make sections of approximately 0.2- to 0.4-mm thickness parallel to the substrate surface and the determination of the glucosamine content in each slice. Use of glucosamine measurements to estimate biomass concentrations was shown to be problematic due to the large variations in glucosamine content with mycelial age. The second method was a novel method based on the use of confocal scanning laser microscopy to estimate the fractional volume occupied by the biomass. Although it is not simple to translate fractional volumes into dry weights of hyphae due to the lack of experimentally determined conversion factors, measurement of the fractional volumes in themselves is useful for characterizing fungal penetration into the substrate. Growth of penetrative biomass in the artificial model substrate showed two forms of growth with an indistinct mass in the region close to the substrate surface and a few hyphae penetrating perpendicularly to the surface in regions further away from the substrate surface. The biomass profiles against depth obtained from the confocal microscopy showed two linear regions on log-linear plots, which are possibly related to different oxygen availability at different depths within the substrate. Confocal microscopy has the potential to be a powerful tool in the investigation of fungal growth mechanisms in solid-state fermentation. (C) 2003 Wiley Periodicals, Inc.
Resumo:
A new questionnaire, the Maternal Mental State Input Inventory (MMSII) was created to measure mothers' preferences for introducing and elaborating on mental states in conversation with their young children. In two studies, the questionnaire was given to mothers of young children, and the children's theory of mind (ToM) development was assessed with standard tasks. In both studies, the questionnaire exhibited good internal reliability, and significant correlations emerged between mothers' self-reported preferences for elaborated, explanatory talk about the mental states and children's theory of mind performance. Further, mothers' conversational preferences, as measured by the MMSII, were the best predictors of children's theory of mind development when relevant control variables were included in the analyses. These results converge with naturalistic observational research that has demonstrated links between mothers' conversational styles and their children's theory of mind. They go further in suggesting that mothers' tendencies toward elaborated, explanatory talk about a range of mental states is particularly beneficial to children's theory of mind development. (C) 2003 Elsevier Inc. All rights reserved.
Resumo:
Low-temperature (15 K) single-crystal neutron-diffraction structures and Raman spectra of the salts (NX4)(2)[CU(OX2)(6)](SO4)(2), where X = H or D, are reported. This study is concerned with the origin of the structural phase change that is known to occur upon deuteration. Data for the deuterated salt were measured in the metastable state, achieved by application of 500 bar of hydrostatic pressure at similar to303 K followed by cooling to 281 K and the subsequent release of pressure. This allows for the direct comparison between the hydrogenous and deuterated salts, in the same modification, at ambient pressure and low temperature. The Raman spectra provide no intimation of any significant change in the intermolecular bonding. Furthermore, structural differences are few, the largest being for the long Cu-O bond, which is 2.2834(5) and 2.2802(4) Angstrom for the hydrogenous and the deuterated salts, respectively. Calorimetric data for the deuterated salt are also presented, providing an estimate of 0.17(2) kJ/mol for the enthalpy difference between the two structural forms at 295.8(5) K. The structural data suggest that substitution of hydrogen for deuterium gives rise to changes in the hydrogen-bonding interactions that result in a slightly reduced force field about the copper(II) center. The small structural differences suggest different relative stabilities for the hydrogenous and deuterated salts, which may be sufficient to stabilize the hydrogenous salt in the anomalous structural form.
Resumo:
In their 1994 study Taxation and Representation, Deacon and Golding point to the extensive use of press and public relations professionals by governments to promote policy, and to outmanouvre their opponents. With the UK specifically in mind, they warn: 'we cannot ignore the massive expansion of the public relations state.' (p.6). What distinguishes their approach from the more usual preoccupation with the use of 'spin' to 'package' political leaders is a focus on the institutionalisation of public relations within government. In this paper, I explore the utililty of the concept, and consider what the broad features of an Australian 'PR State' might be.
Resumo:
A new wavelet-based adaptive framework for solving population balance equations (PBEs) is proposed in this work. The technique is general, powerful and efficient without the need for prior assumptions about the characteristics of the processes. Because there are steeply varying number densities across a size range, a new strategy is developed to select the optimal order of resolution and the collocation points based on an interpolating wavelet transform (IWT). The proposed technique has been tested for size-independent agglomeration, agglomeration with a linear summation kernel and agglomeration with a nonlinear kernel. In all cases, the predicted and analytical particle size distributions (PSDs) are in excellent agreement. Further work on the solution of the general population balance equations with nucleation, growth and agglomeration and the solution of steady-state population balance equations will be presented in this framework. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
FeBr2 reacts with the S2C2(CN)22- ion (1:1 ratio) in the presence of an excess of t-BuNC in THF to give the mixed ligand [Fe(S2C2(CN)2)(t-BuNC) 4] compound. This neutral product with a formal oxidation state of two for the iron atom was characterized by conductivity measurements, and, i.r., Mössbauer, 13C and 1H n.m.r. spectroscopy. There is a Fe-C p back-donation strengthened towards isocyanide ligands, according to the data of 13C, 1H n.m.r. and Mössbauer spectroscopy.
Resumo:
A survey of Monomachidae species was carried out in anarea of Atlantic rain forest of the Biological Reserve of Duas Bocas, Espírito Santo State, Brazil between September, 1996 and August, 1997. Two species of Mollomachus Klug, 1841, M. fuscator Perty, 1833 and M. eurycephalus Schletterer, 1890 were collected from May to September. Both species are typical of winter time and showed the same parttern of seasonality.
Resumo:
Foi feito um levantamento da fauna de Hymenoptera parasitóides em um transecto eucalipto/vegetação nativa/eucalipto, em Ipaba, Minas Gerais, no período de março de 1997 a março de 1998, com armadilhas Malaise. Foram coletados indivíduos de nove superfamílias (Ceraphronoidea, Chalcidoidea, Chrysidoidea, Cynipoidea, Evanioidea, Ichneumonoidea, Proctotrupoidea, Platygastroidea e Vespoidea), distribuídos em 26 famílias.
Resumo:
A Reserva Biológica de Duas Bocas (2.190 ha) é um dos maiores remanescentes de Mata Atlântica do Estado do Espírito Santo, Sudeste do Brasil. Nós amostramos tetrápodes não voadores nessa área entre maio de 2007 e abril de 2008, utilizando armadilhas de queda, armadilhas de isca, armadilhas fotográficas e buscas oportunísticas diurnas e noturnas. Além disso, nós compilamos registros de vertebrados não voadores ocorrentes nesta área disponíveis na literatura e através de espécimes em museus. Nós documentamos 52 espécies de anfíbios, 24 espécies de répteis não voadores e 39 espécies de mamíferos não voadores. Do total de 115 espécies, 47 configuram novos registros para a área e seis outras espécies tiveram sua distribuição geográfica ampliada com os resultados do presente estudo. Além disso, apresentamos o registro de predação da perereca Hypsiboas faber pela serpente Chironius bicarinatus. Cinco das espécies registradas são listadas como ameaçadas no Estado do Espírito Santo e muitas outras possuem estado de conservação incerto. A Reserva Biológica de Duas Bocas é um importante refúgio de vida selvagem, principalmente quando consideramos a expansão de áreas urbanas no seu entorno.
Resumo:
Muitos alimentos são conhecidos apenas em alguns grupos humanos, por diversas razões. Outros, entretanto, tornaram-se praticamente universais, sendo conhecidos e apreciados em quase todas as sociedades humanas com condições econômicas que permitam sua inclusão no âmbito do comércio internacional. Um deles, em especial, está no foco de interesse da presente investigação. Não se trata de alimento relevante para a composição dos hábitos alimentares cotidianos em qualquer grupo humano, mas que ocupa posição privilegiada em termos de preferência em diferentes lugares do mundo: o chocolate. O presente trabalho buscou conhecer e analisar fatores que influenciam o consumo de chocolate de um conjunto de pessoas e as modalidades de explicação ou justificação que apresentam para o seu padrão de consumo e para o tipo de interesse que têm pelo chocolate. Para a coleta de dados foi utilizado um questionário com 62 questões fechadas e 1 questão aberta - que utilizou a técnica da evocação. Participaram 313 homens e mulheres, a maioria na faixa etária entre 16 e 25 anos. Foram exploradas variáveis como situação sócio-econômica, peso corporal, estado de saúde, frequência e quantidade de chocolate consumido, preferência em relação ao consumo de alimentos em geral, além de terem sido verificadas quais situações os participantes admitem estarem associadas a variações no padrão de consumo de chocolate, tendo sido incluídas tanto situações estressantes quanto relaxantes. Foram abordados também alguns pontos considerados controversos a respeito do consumo de chocolate, que são objeto de interesse científico e merecem grande atenção dos meios de comunicação. Houve interesse especial na discussão das diferenças encontradas quando os padrões de consumo de homens e mulheres são comparados. Ficou evidente, no grupo de participantes, que a influência de muitos dos aspectos considerados sobre o consumo do chocolate não se processam de forma idêntica sobre homens e mulheres. Confirma-se a grande difusão cultural da ideia de que mulheres comem mais chocolate que homens e que a seleção de alimentos feminina é mais sensível a fatores associados a variações de estados afetivos, o que pode ter papel na discussão de dependências e transtornos alimentares. Em consonância com a literatura sobre comportamento alimentar, os dados apoiam a proposição de que é insuficiente considerar apenas fatores culturais ou biológicos, de maneira isolada, para explicar os motivos que levam ao consumo de determinados alimentos.