9,684 research outputs found
Characterization and Representation of Weighted Core Inverse of Matrices
In this paper, we introduce new representation and characterization of the
weighted core inverse of matrices. Several properties of these inverses and
their interconnections with other generalized inverses are explored. Through
one-sided core and dual-core inverse, the existence of a generalized weighted
Moore-Penrose inverse of matrices is proposed. Further, by applying a new
representation and using the properties of the weighted core inverse of a
matrix, we discuss a few new results related to the reverse order law for these
inverses.Comment: 18 page
Surfactant mediated synthesis and characterization of Zinc Oxide nanoparticles
ZnO nanoparticles were prepared synthesized by using wet chemical route directly from an aqueous solution of zinc acetate dehydrate and in the presence of sodium dodecyl sulfate (SDS) and sodium hydroxide. ZnO is an interesting semiconductor material due to its application on solar cells, gas sensors, ceramics, catalysts, cosmetics. The as-synthesized Zn(OH)2powders were calcined at various temperatures of 500„aC, 650„aC, 800oC and 1000„aC. The materials prepared were characterized by DSC-TGA, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy. From the thermal studies the mass loss was found to be only 19%. Results show that the calcinations temperature significantly affected the crystalline nature, and optical properties of the processed ZnO nanoparticles. The XRD spectra indicate that the ZnO crystal has a hexagonal wurtzite structure. Zinc oxide showed excellent UV absorption and transparency in the visible region
Experiments on a Blunt Cone Model in a Hypersonic Shock Tunnel
The experimental investigation on a 600 apex-angle is carried out to study feasibility of simultaneous measurement of drag and aerodynamic heating in a shock tunnel. A three-component accelerometer balance system is used to measure the drag whereas platinum thin film gauges are used for heating rate measurements on the surface of the blunt cone model. Since every ground test and flight test data have unique test conditions, so the importance of simultaneous measurement is realized by measuring both drag and heating rates under unique test conditions during gas injection at the nose of a blunt cone model flying at Mach 5.75, in a IISc hypersonic shock tunnel (HST2). In addition, flow visualization experiments are also conducted on the blunt cone model using electric discharge technique
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