9,469 research outputs found

    Parameter Selection for Experimental Investigation of Machining Parameters of Inconel -718 for Turning Operation for Green Machining Using AHP

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    The most important part in experimental investigation is Parameter selection. The parameter plays crucial role in type of investigation or the performance evaluation. There are many methods to select the parameters. In this research we proposed Analytical Hierarchy Process (AHP) to select the parameter for the experimental investigation of machining parameters of Inconel-718 for turning operation. It will include the structural investigation and questionarie. The Sattey scale is used for the pairwise comparison. There are various parameters we are considering for experimental investigations .These are like Cutting Speed , Feed, Depth of cut, Material removal rate (MRR),surface roughness, tool wear, helix angle etc

    Metallicity Evolution of Damped Lyman-Alpha Galaxies

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    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

    Rising incidence of hip fractures in Sindhudurg west coast of Maharashtra, South India (2000 to 2011)

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    Background: The incidence of hip fractures in Sindhudurg, west coast of Maharashtra has been reported in relation to age and gender.Methods: Using the medical records and X-ray registers from May 2000 to October 2011, all patients of proximal femoral fractures were recorded and included in this study. The data was cross checked doubly with details of indoor case papers against ward admission and operation theatre registers, were found to be congruent after verifying the names of patients.Results: The total male incidence was bimodal with moderate peaks at 31 to 50 years and very high at 51 to 70 years. The female incidence with peaks at 41 to 60 years with regular steady increase up to 80 years. Males of 31 to 70 years 2.5 times more likely to sustain a fracture (95% CI 2.3 to 2.8) than females. Females between 40 to 60 years 2.8 times more likely to sustain fracture than males (95% CI 2.5 to 3.0). The trend was stable from year to year. This high increase in hip fractures in men of 51 to 70 years incidence documented osteoporotic fractures in contrast with too much emphasis on the importance of menopause in hip fractures.Conclusions: Despite wide variations in age specific hip fracture rates over a decade, reasons for differences are not clear. From 2000 to 2011, the hip fractures in district hospital increased by a factor of 6.6%, 14.34% in both the genders above the age of 41 years in parallel with hospital admissions.

    Magnetic properties and complex magnetic phase diagram in non centrosymmetric EuRhGe3_3 and EuIrGe3_3 single crystals

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    We report the magnetic properties of two Eu based compounds, single crystalline EuIrGe3_3 and EuRhGe3_3, inferred from magnetisation, electrical transport, heat capacity and 151^{151}Eu M\"{o}ssbauer spectroscopy. These previously known compounds crystallise in the non-centrosymmetric, tetragonal, I4mmI4mm, BaNiSn3_3-type structure. Single crystals of EuIrGe3_3 and EuRhGe3_3 were grown using high temperature solution growth method using In as flux. EuIrGe3_3 exhibits two magnetic orderings at TN1T_{\rm N1} = 12.4 K, and TN2T_{\rm N2} = 7.3 K. On the other hand EuRhGe3_3 presents a single magnetic transition with a TNT_{\rm N} = 12 K. 151^{151}Eu M\"{o}ssbauer spectra present evidence for a cascade of transitions from paramagnetic to incommensurate amplitude modulated followed by an equal moment antiferromagnetic phase at lower temperatures in EuIrGe3_3, the transitions having a substantial first order character. On the other hand the 151^{151}Eu M\"{o}ssbauer spectra at 4.2 and 9 K in EuRhGe3_3 present evidence of a single magnetic transition. In both compounds a superzone gap is observed for the current density JJ\parallel [001], which enhances with transverse magnetic field. The magnetisation measured up to 14 T shows the occurrence of field induced transitions, which are well documented in the magnetotransport data as well. The magnetic phase diagram constructed from these data is complex, revealing the presence of many phases in the HTH-T phase space
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