This study is devoted to seismic collapse safety analysis of performance based optimally seismic designed steel chevron braced frame structures. An efficient meta-heuristic algorithm namely, center of mass optimization is utilized to achieve the seismic optimization process. The seismic collapse performance of the optimally designed steel chevron braced frames is assessed by performing incremen...

In this paper, we investigate a potential two-scale traveling wave singularity of the 3D incompressible axisymmetric Euler equations with smooth initial data finite energy. The feature is characterized by property that center approaches to origin at slower rate than collapse singularity. driving mechanism for due two antisymmetric vortex dipoles generate strong shearing layer in both radial and...

Modeling the fuel injection process in modern gasoline direct engines plays a principal role characterizing in–cylinder mixture formation and subsequent combustion process. Flash boiling, which usually occurs when is injected into an ambient pressure below saturation of liquid, characterized by fast breakup evaporation rates but could lead to undesired behaviors such as spray collapse, signific...

OBJECTIVE To determine frequencies of different MRI patterns of tuberculous spondylitisin a public sector hospital in Karachi. METHODS This descriptive multidisciplinary case series study was done from October 25, 2011 to May 28, 2012 in Radiology Department and Department of Medicine in the Jinnah Postgraduate Medical Center Karachi. MRI scans (dorsal / lumbosacral spine) of the Patients pre...

I study the role of shear fields on the evolution of density perturbations by using an analytical approximate solution for the equations of motion of homogeneous ellipsoids embedded in a homogeneous background. The equations of motion of a homogeneous ellipsoid (Icke 1973; White & Silk 1979 (hereafter WS)) are modified in order to take account of the tidal field as done in Watanabe 1993 and the...

CONTEXT Tracheobronchomalacia (TBM) results from structural and functional abnormalities of the respiratory system. It is characterized by excessive collapse: at least 50% of the cross-sectional area of the trachea and main bronchi. In this paper, we present a rare case of a patient with TBM who first presented with stridor and respiratory failure due to exacerbation of chronic bronchitis. CA...

plan irregularity causes local damages being concentrated in the irregular buildings. progressive collapse is also the collapse of a large portion or whole building due to the local damages in the structure. the effect of irregularity on the progressive collapse potential of the buildings is investigated in this study. this is carried out by progressive collapse evaluation of the asymmetric mid...

We derive probability density functions for the projected axial ratios of the real and mock 2PIGG galaxy groups, and use this data to investigate the intrinsic three dimensional shape of the dark matter ellipsoids that they trace. As well as analysing the raw data for groups of varying multiplicities, a convolution corrected form of the data is also considered which weights the probability dens...

Turbulent boundary layer measurements have been made on surfaces covered with filamentous marine algae. These experiments were conducted in a closed return water tunnel using a two-component, laser Doppler velocimeter (LDV). The mean velocity profiles and parameters, as well as the axial and wall-normal turbulence intensities and Reynolds shear stress, are compared with flows over smooth and sa...

The neurofibrillary tangles that occur in the brain in cases of senile dementia of the Alzheimer type contain a distinctive type of filament, the paired helical filament (PHF). We have developed a method for isolating the tangles postmortem in sufficient yield for structural study of PHFs by electron microscopy of negatively stained and shadowed preparations. This material shows the characteris...