Design of Blast Resistant Structure

A shock blast resistant structure designed, developed and experimentally evaluated by the authors is described. We structure, capable of with standing dynamic loading (12 psi and a static pressure of 1.5 m earth cover) due to blast or any other explosion, also gives protection against radiation, chemical and thermal hazards. Some results and details of analysis and experimentation are presented

Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on such fibre-reinforced plastic corrugated sheets have been suggested for -better comparison

Controlled synthesis of crystalline tellurium nanorods, nanowires, nanobelts and related structures by a self-seeding solution process

Single crystalline nanorods and nanowires of t-Te have been prepared by a simple solution route. The procedure involves the disproportionation of NaHTe, prepared by the reduction of Te with NaBH4. By carefully controlling the reaction conditions, the diameter of the nanorods could be varied in the 20-300 nm range. Nanowires of 10 nm diameter were obtained in the presence of sodium dodecylbenzenesulfonate. Te nanobelts and nano junctions were obtained by employing hydrothermal and solvothermal conditions. The nanorods have been characterized by a variety of microscopic and spectroscopic techniques. UV-Visible spectra reveal two absorption bands, one around 300 nm which is size-sensitive and the other at 600 nm insensitive to size

Functions preserving nonnegativity of matrices

The main goal of this work is to determine which entire functions preserve nonnegativity of matrices of a fixed order $n$ -- i.e., to characterize entire functions $f$ with the property that $f(A)$ is entrywise nonnegative for every entrywise nonnegative matrix $A$ of size $n\times n$. Towards this goal, we present a complete characterization of functions preserving nonnegativity of (block) upper-triangular matrices and those preserving nonnegativity of circulant matrices. We also derive necessary conditions and sufficient conditions for entire functions that preserve nonnegativity of symmetric matrices. We also show that some of these latter conditions characterize the even or odd functions that preserve nonnegativity of symmetric matrices.Comment: 20 pages; expanded and corrected to reflect referees' remarks; to appear in SIAM J. Matrix Anal. App

Structural studies of 1:1 quinone-hydroquinone complexes

The structures of the 1:1 quinone-hydroquinone complexes of 2-phenyl and of 2-(4'-chloro) phenylbenzoquinone have been studied by X-ray methods. A superficial study would indicate that the quinhydrones are centrosymmetric and belong to the space group P21/c. However, other evidence indicates that the true crystal structure may belong to either the space group P21 or to Pc, or that the crystal may contain regions that would coresspond to each of these two non-centrosymmetric space groups. Some possible consequences of such a structural arrangement are briefly discussed

Architecture of the Hin Synaptic Complex during Recombination The Recombinase Subunits Translocate with the DNA Strands

AbstractMost site-specific recombinases can be grouped into two mechanistically distinct families. Whereas tyrosine recombinases exchange DNA strands through a Holliday intermediate, serine recombinases such as Hin generate double-strand breaks in each recombining partner. Here, site-directed protein crosslinking is used to elucidate the configuration of protein subunits and DNA within the Hin synaptic complex and to follow the movement of protein subunits during DNA strand exchange. Our results show that the protein interface mediating synapsis is localized to a region within the catalytic domains, thereby positioning the DNA strands on the outside of the Hin tetrameric complex. Unexpected crosslinks between residues within the dimerization helices provide evidence for a conformational change that accompanies DNA cleavage. We demonstrate that the Hin subunits, which are linked to the cleaved DNA ends by serine-phosphodiester bonds, translocate between synapsed dimers to exchange the DNA strands