Shear deformation analysis on laser-induced reverse bulging and plugging

A new kind of failure mode is observed in circular brass foils in which their peripheries are fixed and their surfaces are subjected to a long pulsed laser over a central region. The failure is classified into three stages; they are referred to as thermal bulging, localized shear deformation and perforation by plugging. A distinct feature of the failure mode is that bulging and plugging occurred in the direction opposite to the incident laser beam. To study the failure mode, we investigate the non-linear response of heated, non-homogeneous circular plates. Based on the large deflection equations of Berger [J. Appl. Mech. 22 (3), 465-472 (1965)], Ohnabe and Mizuguchi [Int. J. Non-Linear Mech. 28 (4), 365-372 (1993)] and the parabolic shear deformation theory of Bhimaraddi and Stevens [J. Appl. Mech. 51 (1), 195-198 (1984)], we have derived new coupled governing equations of shear deformation and deflection. The new equations are solved, for the plate with a clamped edge, by the Galerkin and iterative methods. The numerical results for the shear deformation distribution are in good agreement with the experimental observation.

Significant Residue Features Revealed By Eigenvalue Decomposition Analysis Of Blosum Matrices

Here we attempt to characterize protein evolution by residue features which dominate residue substitution in homologous proteins. Evolutionary information contained in residue substitution matrix is abstracted with the method of eigenvalue decomposition. Top eigenvectors in the eigenvalue spectrums are analyzed as function of the level of similarity, i.e. sequence identity (SI) between homologous proteins. It is found that hydrophobicity and volume are two significant residue features conserved in protein evolution. There is a transition point at SI approximate to 45%. Residue hydrophobicity is a feature governing residue substitution as SI >= 45%. Whereas below this SI level, residue volume is a dominant feature. (C) 2007 Elsevier B.V. All rights reserved.

Shock-induced two-phase flows in an aligned baffle system filled with suspended particles

This paper describes the shock propagation through a dilute gas-particle suspension in an aligned baffle system. Numerical solution to two-phase flows induced by a planar shock wave is given based on the two-continuum model with interphase coupling. The governing equations are numerically solved by using high-resolution schemes. The computational results show the shock reflection and diffraction patterns, and the shock-induced flow fields in the 4-baffle system filled with the dusty gas.

[Discurso do Deputado Colombo de Sousa : Sessão da Câmara dos Deputados de 06 de maio de 1957]

Leitura da oração congratulatória com que o Arcebispo de São Paulo, Dom Carlos Carmelo de Vasconcelos comemorou a celebração da Primeira Missa em Brasília, futura capital do país.

Steady axi-symmetrical thermocapillary motion of a short melting column

This paper deals with the steady axi-symmetric thermo-capillary motion in a short meltingcolumn.with the assumptions that the Marangoni number M<<1, the Reynolds number Re<<1 andthe capillary number C<<1, at the leading order, the solutions of the problem are obtained inthe form of series. For two kinds of typical cases, symmetric and anti-symmetric distributionof air temperature, the numerical calculations are made. The results describe the effect ofendwalls on thermo-capillary flow.

苯乙烯/丙烯酸正丁酯/丙烯酸共聚微球的制备及其性能表征

通过乳液聚合法和无皂乳液聚合法制备了苯乙烯/丙烯酸正丁酯/丙烯酸共聚微球.讨论了乳化剂用量、引发剂用量、功能单体、软硬单体用量比等对微球粒径和形态的影响.利用扫描电子显微镜(SEM)、傅立叶变换红外光谱仪(FTIR)对微球的粒径、形貌和表面基团进行分析.红外光谱表明,实验室所制备的苯乙烯/丙烯酸正丁酯/丙烯酸共聚微球表面存在丰富的羧基.利用竖片生长法得到自组装的多层胶体微球薄膜.通过对薄膜的反射光谱测量,发现随着湿度的增加,峰位会产生3nm左右的红移.

弱粘性流体中垂直激励表面波的阻尼效应

在竖直振动的圆柱形容器中，将Navier-Stokes方程线性化，利用两时间尺度奇异摄动展开法研究了弱粘性流体的单一自由面驻波运动．整个流场被分为外部势流区和内部边界层区两部分，对两部分区域分别求解，得到包含阻尼项和外驱动影响的线性振幅方程．利用稳定性分析，得到形成稳定表面波的条件，给出了临界曲线．此外，还获得了阻尼系数的解析表达式．最后，将线性阻尼加到理想流体条件下所得到的色散关系中对其进行修正，理论结果证明修正后的驱动频率更加接近实验的结果．通过计算发现，当驱动的频率较低时，流体的粘性对表面波模式选择有重要影响，而表面张力的影响不明显；但当驱动频率较高时，流体的表面张力起主要作用，而流体的粘性影响甚小．

Avaliando Minas : índice de sustentabilidade da mineração (ISM)

Estudo de um sistema de avaliação para a construção do Índice de Sustentabilidade da Mineração (ISM), a partir da proposição e agregação de indicadores nas dimensões econômica, social e ambiental e sua aferição em unidades operacionais minerárias selecionadas, incluindo as comunidades existentes em seu entorno e o município em que elas se inserem. Como marco referencial, são analisadas questões afetas ao desenvolvimento sustentável e seus indicadores, bem como à mineração sustentável e às iniciativas de proposição de indicadores para o setor.