Charge order suppression and antiferromagnetic to ferromagnetic switch over in Pr_0.5Ca_0.5MnO_3 nanowires

We have prepared crystalline nanowires (diameter ~ 50 nm, length ~ a few microns) of the charge ordering manganite Pr_0.5Ca_0.5Mn_O3 using a low reaction temperature hydrothermal method and characterized them using X-ray diffraction, transmission electron microscopy, SQUID magnetometry and electron magnetic resonance measurements. While the bulk sample shows a charge ordering transition at 245 K and an antiferromagnetic transition at 175 K, SQUID magnetometry and electron magnetic resonance experiments reveal that in the nanowires phase, a ferromagnetic transition occurs at ~ 105 K. Further, the antiferromagnetic transition disappears and the charge ordering transition is suppressed. This result is particularly significant since the charge order in Pr_0.5Ca_0.5MnO_3 is known to be very robust, magnetic fields as high as 27 T being needed to melt it.Comment: 12 pages including 4 figures. submitted to Applied Physics Letter

Implications of binary black hole detections on the merger rates of double neutron stars and neutron star-black holes

We show that the inferred merger rate and chirp masses of binary black holes (BBHs) detected by advanced LIGO (aLIGO) can be used to constrain the rate of double neutron star (DNS) and neutron star - black hole (NSBH) mergers in the universe. We explicitly demonstrate this by considering a set of publicly available population synthesis models of \citet{Dominik:2012kk} and show that if all the BBH mergers, GW150914, LVT151012, GW151226, and GW170104, observed by aLIGO arise from isolated binary evolution, the predicted DNS merger rate may be constrained to be $2.3-471.0$~\rate~ and that of NSBH mergers will be constrained to $0.2-48.5$~\rate. The DNS merger rates are not constrained much but the NSBH rates are tightened by a factor of $\sim 4$ as compared to their previous rates. Note that these constrained DNS and NSBH rates are extremely model dependent and are compared to the unconstrained values $2.3-472.5$ \rate~ and $0.2-218$ \rate, respectively, using the same models of \citet{Dominik:2012kk}. These rate estimates may have implications for short Gamma Ray Burst progenitor models assuming they are powered (solely) by DNS or NSBH mergers. While these results are based on a set of open access population synthesis models which may not necessarily be the representative ones, the proposed method is very general and can be applied to any number of models thereby yielding more realistic constraints on the DNS and NSBH merger rates from the inferred BBH merger rate and chirp mass.Comment: 5 pages, no figures, 4 tables, v2: matches published versio

Transverse Single Spin Asymmetries and Charmonium Production

We estimate transverse spin single spin asymmetry(TSSA) in the process $e+p^\uparrow \to J/\psi +X$ using color evaporation model of charmonium production. We take into account transverse momentum dependent(TMD) evolution of Sivers function and parton distribution function and show that the there is a reduction in the asymmetry as compared to our earlier estimates wherein the $Q^2$ - evolution was implemented only through DGLAP evolution of unpolarized gluon densities.Comment: Proceedings of Light Cone 2012, New Delhi, Indi

Single Spin Asymmetry in Charmonium Production

We present estimates of Single Spin Asymmetry (SSA) in the electroproduction of $J/\psi$ taking into account the transverse momentum dependent (TMD) evolution of the gluon Sivers function and using Color Evaporation Model of charmonium production. We estimate SSA for JLab, HERMES, COMPASS and eRHIC energies using recent parameters for the quark Sivers functions which are fitted using an evolution kernel in which the perturbative part is resummed up to next-to-leading logarithms (NLL) accuracy. We find that these SSAs are much smaller as compared to our first estimates obtained using DGLAP evolution but are comparable to our estimates obtained using TMD evolution where we had used approximate analytical solution of the TMD evolution equation for the purpose.Comment: Conference proceedings of Light Cone 2014 at Raleigh, NC, USA. Talk presented by Prof. Anuradha Misra. arXiv admin note: text overlap with arXiv:1411.083

Discrimination of closely resembling PEC targets based on natural resonant frequencies

The Natural Resonant Frequencies (NRFs) obtained from the late time response of targets are aspect independent in nature and thus, is well suited for radar target identification. In resonance based identification techniques, the accurate determination of NRFs is very important. In this paper, a technique for identifying the true NRFs of objects, useful in discriminating two closely resembling objects is proposed. The NRFs are extracted from the E-field response of the object using the Vector Fitting (VF) method. The NRFs of database object and the Radar Cross Section (RCS) of unknown object are used to discriminate between them. A risk factor is defined as a measure of discrimination. In this study, ellipsoids with different axial ratios are considered for discrimination and the results are presented

EFFICACY OF WATTAKAKA VOLUBILIS AGAINST ALUMINIUM SULPHATE INDUCED IN LIVER TOXICITY

Objective: The modulation of membrane-bound ATPases, carbohydrate metabolizing enzymes and mitochondrial TCA cycle enzymes in Wattakaka volubilis on aluminium sulphate induced liver toxicity.Methods: Medicinal therapy requires careful assessment of effective treatment offering an acceptable safety over human health. Experimental animals were divided into five groups (Untreated, negative and positive control, hepatic group and the hepatic group fed on Wattakaka volubilis), Metabolising enzymes level, estimation of DNA, RNA and quantification of DNA fragmentation and gene expression were investigated. These altered enzyme levels were ameliorated significantly by administration of Wattakaka volubilis at the concentration of 200 mg/kg in drug-treated animals.Results: Results showed that treatment with methanol extract of Wattakaka volubilis normal level of enzymes which are compared with silymarin. This was evident from the significant increase in p<0.05, p<0.01, p<0.001 enzyme levels. Aluminium sulphate induced rats showed decreased the activities of metabolising enzymes and increased DNA fragmentation in the liver. This clearly explained the reason for the hepatoprotective activity of Wattakaka volubilis leaf extract.Conclusion: The methanolic leaf extract of W. volubilis showed high protective activity against aluminium sulphate-induced hepatotoxicity