Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

Peer reviewedPublisher PD

Metallicity Evolution of Damped Lyman-Alpha Galaxies

We have reanalyzed the existing data on Zinc abundances in damped Ly-alpha (DLA) absorbers to investigate whether their mean metallicity evolves with time. Most models of cosmic chemical evolution predict that the mass- weighted mean interstellar metallicity of galaxies should rise with time from a low value ~ 1/30 solar at z ~ 3 to a nearly solar value at z ~ 0. However, several previous analyses have suggested that there is little or no evolution in the global metallicity of DLAs. We have used a variety of statistical techniques to quantify the global metallicity-redshift relation and its uncertainties, taking into account both measurement and sampling errors. Three new features of our analysis are: (a) an unbinned N(H I)-weighted nonlinear chi-square fit to an exponential relation; (b) survival analysis to treat the large number of limits in the existing data; and (c) a comparison of the data with several models of cosmic chemical evolution based on an unbinned N(H I)-weighted chi-square. We find that a wider range of evolutionary rates is allowed by the present data than claimed in previous studies. The slope of the exponential fit to the N(H I)-weighted mean Zn metallicity vs. redshift relation is -0.20 plus minus 0.11 counting limits as detections and -0.27 plus minus 0.12 counting limits as zeros. Similar results are also obtained if the data are binned in redshift, and if survival analysis is used. These slopes are marginally consistent with no evolution, but are also consistent with the rates predicted by several models of cosmic chemical evolution. Finally, we outline some future measurements necessary to improve the statistics of the global metallicity-redshift relation.Comment: 25 pages, 1 figure, accepted for publication in the Astrophysical Journa

Hot forming of silicon sheet, silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

The hot workability of polycrystalline silicon was studied. Uniaxail stress-strain curves are given for strain rates in the range of .0001 to .1/sec and temperatures from 1100 to 1380 C. At the highest strain rates at 1380 C axial strains in excess of 20% were easily obtainable without cracking. After deformations of 36%, recrystallization was completed within 0.1 hr at 1380 C. When the recrystallization was complete, there was still a small volume fraction of unrecyrstallized material which appeared very stable and may degrade the electronic properties of the bulk materials. Texture measurements showed that the as-produced vapor deposited polycrystalline rods have a 110 fiber texture with the 110 direction parallel to the growth direction and no preferred orientation about this axis. Upon axial compression perpendicular to the growth direction, the former 110 fiber axis changed to 111 and the compression axis became 110 . Recrystallization changed the texture to 110 along the former fiber axis and to 100 along the compression axis

Gaplessness and the Coulomb anomaly in the strongly disordered films of Molybdenum Carbide

Gaplessness was observed in the disordered films of MoC on approaching to the superconductor to insulator transition by reducing the film thickness. The gaplessness is attributed to the enhanced Coulomb interactions due to the loss of screening in the presence of strong disorder in the films.Comment: 3 pages, 5 figure

Vapour Pressure of Barium Metal & Study of the Equilibrium Reaction Ba(g)+BaCl2(c) =2BaCl(g) at High Temperature

964-96

Study of the Reaction Mn(c)+AlCl(g)=MnCl(g)+Al(l)*

198-20

Dissociation of Manganous Sulphide at High Temperatures & the Study of Its Reaction with Carbon

288-29

Supracondylar fracture of femur: our experience of treatment with locking compression plate from rural Maharashtra

Background: Surgical treatment of supracondylar or intercondylar distal femoral fractures (AO/OTA types 33-A to 33-C) remains a significant surgical challenge with significant complication rates. Supracondylar and intercondylar fractures of femur are very often difficult to treat and they are notorious for many complications. We have studied use of LCP (locking compression plate) in the treatment of metaphyseal fractures. These implants improve fracture healing, especially in osteoporotic bone due to better holding capacity. Objective wass to assess the efficacy of LCP in maintenance of post-operative distal femoral alignment and in preventing post-operative varus collapse in supracondylar fracture of femur.Methods: Prospective Longitudinal observational study Conducted at Post Graduate Institute of Swasthiyog Pratishthan, Miraj, Maharashtra involving 50 patients with supracondylar fracture. The fractures were classified as supracondylar femur fracture (AO/OTA type 33) (A- C). Fractures that were supracondylar with significant proximal fracture extension were classified as an AO/OTA type 33 fracture unless there was a separate diaphyseal fracture. Data was analysed by using SPSS 16.0 version and expressed as percentages.Results: Majority of patients were from 30-39 years age group i.e. 32%. Majority of patients were males i.e. 46 (92%). 7 (14%) patients had healing time <4 months. 24 (48%) patients had healing time between 4-6 months. 19 (38%) patients had healing time more than 6 months. To assess the overall results, we used Knee society score. In 38% of patients, we found excellent results. Good and fair results were seen in 32% and 26% of patients.Conclusion: Locking compression plate is an ideal implant for fixation of supracondylar fracture of femur 33 (A-C) especially in C3 type where articular comminution is present