Structural and physical properties of Sm3+ doped magnesium zinc sulfophosphate glass

Samarium (Sm3+ ) doped magnesium zinc sulfophosphate glass system of composition (60-x)P2O5-20MgO-20ZnSO4-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol%) were synthesized using melt-quenching technique. The structure and physical properties of prepared glass samples were characterized. The X-ray diffraction pattern verified their amorphous nature. The physical properties such as density, refractive index, molar volume, rare earth ion concentration, etc. were calculated. The decrease in the optical bandgap energy with increasing Sm2O3 contents was attributed to the alteration in the glass network structures. Fourier transformed infrared spectra and Raman analyses manifested the depolymerization of ZnSO4 in the phosphate host matrix. The present findings may be beneficial for the advancement of functional glasses

Mass Hierarchy Determination via future Atmospheric Neutrino Detectors

We study the problem of determination of the sign of Delta m^2_{31}, or the neutrino mass hierarchy, through observations of atmospheric neutrinos in future detectors. We consider two proposed detector types : (a) Megaton sized water Cerenkov detectors, which can measure the survival rates of nu_\mu + \bar{\nu}_\mu and nu_e + \bar{\nu}_e and (b) 100 kton sized magnetized iron detectors, which can measure the survival rates of \nu_\mu and \bar{\nu}_\mu. For energies and path-lengths relevant to atmospheric neutrinos, these rates obtain significant matter contributions from P_{\mu e}, P_{\mu \mu} and P_{ee}, leading to an appreciable sensitivity to the hierarchy. We do a binned \chi^2 analysis of simulated data in these two types of detectors which includes the effect of smearing in neutrino energy and direction and incorporates detector efficiencies and relevant statistical, theoretical and systematic errors. We also marginalize the \chi^2 over the allowed ranges of neutrino parameters in order to accurately account for their uncertainties. Finally, we compare the performance of both types of detectors vis a vis the hierarchy determination.Comment: 36 pages, 13 figures, revised version accepted in Physical Review

Comprehensive thermal and structural characterization of antimony-phosphate glass

For the first time, we prepare new ternary glass systems of composition (95-x)Sb2O3-xP2O5-5MgO, where x = 45, 40, 35 mol%; (85-x)Sb2O3-xP2O5-15MgO, where x = 55, 35, 25 mol%; (75-x)Sb2O3-xP2O5-25MgO, where x = 45, 35, 25 mol%; and 60Sb2O3-(40-x)P2O5-xMgO, where x = 10, 20 mol% via melt-quenching method. Synthesized glasses are characterized using XRD, FESEM, EDX, and TG/DTA measurements. The influence of varying modifier concentrations on their thermal properties is evaluated. The XRD patterns confirmed the amorphous nature of samples. SEM images demonstrated interesting phase formation with ribbons-like texture. Five crystalline phases are evidenced in the ternary diagram which are antimony phosphate and antimony orthophosphate as major phases as well as magnesium phosphate, magnesium cyclo-tetraphosphate and cervantite as minor phases. EDX spectra detected the right elemental traces. Detailed thermal analysis of these glasses revealed their high-molecular polymer character for Sb2O3 content greater than 50 mol%. Three different glass transition temperatures are achieved around 276, 380–381 and 422–470 °C depending on the composition. Furthermore, the solidus and liquidus temperature are found to decrease with increasing Sb2O3 and increases for MgO contents till 15 mol% and then decrease, where the lowest recorded solidus temperature is 426 °C. This observation may open up new research avenues for antimony based ternary glasses and an exploitation of the derived results for optoelectronics applications, photonic devices and non-linear optical devices

Performance of Concrete Exposed to Corrosive Environment

A comprehensive programme to investigate the behaviour of portland cement concrete exposed to corrosive environment was chalked out in this short duration study.The programme composed of compressive strength study, weight loss study , effect of carbonation, pH test study and study of ultrasonic pulse velocity test. Investigation to study the performance of portland cement concrete of M20 strength exposed to corrosive environment ( 5% H2SO4 Solution, 5% HC 1 Solution, 10% (NH4SO4 Solution and 10% NaOH Sol- ution ) revealed that the concrete cube deteriorated more in acidic environment than alkaline environment. The stre-ngth of PCC exposed to aggressive medium reduced signif- icantly after exposure of 28 days. This reduction in strength was mainly due to expansive salt formation . The formation of expansive salt also resulted in loss of cem-entitious properties and loss of weight. The concrete exposed to H2SO4 solution was found least durable . This study also shows that higher the ultrasonic pulse velocity lower is the corrosion . This paper presents an approach of investigation along with analysis of test results of PCC exposed to corrosive environment

Toda Lattice Models with Boundary

We consider the soliton solutions in 1- and (1+1)-dimensional Toda lattice models with a boundary. We make use of the solutions already known on a full line by means of the Hirota's method. We explicitly construct the solutions satisfying the boundary conditions. The ${\bf Z}_{\infty}$-symmetric boundary condition can be introduced by the two-soliton solutions naturally.Comment: 9 pages, latex, no figure