The Power Spectrum of Galaxies in the Nearby Universe

We compute the power spectrum of galaxy density fluctuations in a recently completed redshift survey of optically-selected galaxies in the southern hemisphere (SSRS2). The amplitude and shape of the SSRS2 power spectrum are consistent with results of the Center for Astrophysics redshift survey of the northern hemisphere (CfA2), including the abrupt change of slope on a scale of 30-50Mpc/h; these results are reproducible for independent volumes of space and variations are consistent with the errors estimated from mock surveys. Taken together, the SSRS2 and CfA2 form a complete sample of 14,383 galaxies which covers one-third of the sky. The power spectrum of this larger sample continues to rise on scales up to ~ 200Mpc/h, with weak evidence for flattening on the largest scales. The SSRS2+CfA2 power spectrum and the power spectrum constraints implied by COBE are well-matched by an Omega*h ~ 0.2, Omega+lambda_0=1 CDM model with minimal biasing of optically-selected galaxies.Comment: Accepted for publication in The Astrophysical Journal Letters, Sept. 23, 1994. 10 pages uuencoded compressed postscript, including two figures. JHU-9410200

Molecular Sieve Silica (MSS) Membranes for Gas Separation and Reaction Processes

Weakly branched silica films formed by the two-step sol-gel process allow for the formation of high selectivity membranes for gas separation. 29Si NMR and gas permeation showed that reduced crosslinking leads to He/CH4 selectivity improvement from 300 to 1000. Applied in membrane reactor for cyclohexane conversion to benzene, conversions were achieved at 14 fold higher than a conventional reactor at 250°C. Hydrothermal stability studies showed that carbon templating of silica is required for hydrothermally stable membranes. From our work it was shown that with correct application of chemistry, practical membrane systems can be built to suit gas separation (e. g. hydrogen fuel) and reactor systems

On quasi-Jacobi and Jacobi-quasi bialgebroids

We study quasi-Jacobi and Jacobi-quasi bialgebroids and their relationships with twisted Jacobi and quasi Jacobi manifolds. We show that we can construct quasi-Lie bialgebroids from quasi-Jacobi bialgebroids, and conversely, and also that the structures induced on their base manifolds are related via a quasi Poissonization

What are the Best Hierarchical Descriptors for Complex Networks?

This work reviews several hierarchical measurements of the topology of complex networks and then applies feature selection concepts and methods in order to quantify the relative importance of each measurement with respect to the discrimination between four representative theoretical network models, namely Erd\"{o}s-R\'enyi, Barab\'asi-Albert, Watts-Strogatz as well as a geographical type of network. The obtained results confirmed that the four models can be well-separated by using a combination of measurements. In addition, the relative contribution of each considered feature for the overall discrimination of the models was quantified in terms of the respective weights in the canonical projection into two dimensions, with the traditional clustering coefficient, hierarchical clustering coefficient and neighborhood clustering coefficient resulting particularly effective. Interestingly, the average shortest path length and hierarchical node degrees contributed little for the separation of the four network models.Comment: 9 pages, 4 figure

Enhanced Ethanol Dehydration with Hydrostable Inorganic Pervaporation Membranes

Membranes which allow water diffusion in favour of other substances can offer increased efficiency in processes to dehydrate ethanol. Silica membranes can perform this selective diffusion, but have mostly been reported for their gas high gas separating ability. This work investigates the effectiveness of carbonised template molecular sieve (CTMSS) membrane to dehydrate ethanol/water mixtures. The silica derived top layer of the membrane was measured at 20nm thickness by XPS sputtering technique. However, the silica enters the porous structure of -alumina layer in excess of 90nm. After 200 minutes of operation, H2O/EtOH selectivity increased to 5.6 from around 1 due to gradual pore filling by adsorbed water and ethanol which contributed to inhibiting ethanol transport. The smaller water molecules were thus favoured in transporting to the permeate side. Total mass flux using a 10% ethanol feed remained constant at around 1.5 kg.m-2.hr-1. Selectivity of up to 9.5 was achieved when azeotropic feed solutions of 95% were used, displaying the potential for this technology for a wide range of ethanol dehydration applications. Pressurising the feed up to 400 kPa doubled the permeate flux, but enhanced the transport of ethanol over water

Coleta de variedades tradicionais (crioulas) de feijoeiro comum (Phaseolus vulgaris L.) na região norte do Rio Grande do Sul.

O objetivo deste trabalho é apresentar informações sobre a coleta de feijão realizada em municípios da região norte do Rio Grande do Sul, como métodos de cultivo, metodologia de coleta, tipos de acessos coletados e futuras avaliações para utilização do germoplasma coletado.bitstream/item/29001/1/doc260.pd

Expedições de coletas de feijão comum (Phaseolus vulgaris) no Brasil.

Objetivando a preservação da diversidade genética ainda existente entre os agricultores tradicionais de feijão comum, foram realizadas expedições de coleta na Região Norte do Rio Grande do Sul e nos Estados de Sergipe, Bahia e Ceará