Magnetotransport in polycrystalline La2/3_{2/3}Sr1/3_{1/3}MnO3_{3} thin films of controlled granularity

Polycrystalline La$_{2/3}$Sr$_{1/3}$MnO$_{3}$ (LSMO) thin films were synthesized by pulsed laser ablation on single crystal (100) yttria-stabilized zirconia (YSZ) substrates to investigate the mechanism of magneto-transport in a granular manganite. Different degrees of granularity is achieved by using the deposition temperature (T$_{D}$) of 700 and 800 $^{0}$C. Although no significant change in magnetic order temperature (T$_C$) and saturation magnetization is seen for these two types of films, the temperature and magnetic field dependence of their resistivity ($\rho$(T, H)) is strikingly dissimilar. While the $\rho$(T,H) of the 800 $^{0}$C film is comparable to that of epitaxial samples, the lower growth temperature leads to a material which undergoes insulator-to-metal transition at a temperature (T$_{P}$ $\approx$ 170 K) much lower than T$_C$. At T $\ll$ T$_P$, the resistivity is characterized by a minimum followed by ln \emph{T} divergence at still lower temperatures. The high negative magnetoresistance ($\approx$ 20$$) and ln \emph{T} dependence below the minimum are explained on the basis of Kondo-type scattering from blocked Mn-spins in the intergranular material. Further, a striking feature of the T$_D$ = 700 $^{0}$C film is its two orders of magnitude larger anisotropic magnetoresistance (AMR) as compared to the AMR of epitaxial films. We attribute it to unquenching of the orbital angular momentum of 3d electrons of Mn ions in the intergranular region where crystal field is poorly defined.Comment: 26 pages, 7 figure

Strain induced magnetic domain evolution and spin re-orientation transition in epitaxial manganite films

The evolution of magnetic domain structure in epitaxial La$_{0.625}$Ca$_{0.375}$MnO$_3$ films on (001) NdGaO$_3$ is monitored as a function of temperature and magnetic field using Magnetic Force Microscopy. We see two distinct regions of magnetic orientational order; one in-plane displaying contrast-less image and the other tilted away from the film plane forming a distinct stripe pattern. A strong domain splitting is observed at the boundary of two regions, which is resilient to reorientation with temperature and magnetic field. We propose a model magnetic free energy functional to explain the mechanism of domain splitting seen in manganite films

Interface driven reentrant superconductivity in HoNi5_5-NbN-HoNi5_5 nanostructures

Superconductivity (S) and ferromagnetism (F) are probed through transport and magnetization measurements in nanometer scale HoNi$_5$-NbN (F-S) bilayers and HoNi$_5$-NbN-HoNi$_5$ (F-S-F) trilayers. The choice of materials has been made on the basis of their comparable ordering temperatures and strong magnetic anisotropy in HoNi$_5$. We observe the normal state reentrant behavior in resistance vs. temperature plots of the F-S-F structures just below the superconducting transition in the limited range of HoNi$_5$ layer thickness d$_{HN}$ (20 nm $<$ d$_{HN}$ $<$ 80 nm) when d$_{NbN}$ is fixed at $\simeq$ 10 nm. The reentrance is quenched by increasing the out-of-plane (H$_{\perp}$) magnetic field and transport current where as in-plane (H$_{\parallel}$) field of $\leq$ 1500 Oe has no effect on the reentrance. The thermally activated flux flow characteristics of the S, F-S and F-S-F layers reveal a transition from collective pinning to single vortex pinning as we place F layers on both sides of the S film. The origin of the reentrant behavior seen here in the range of 0.74 $\leq$ T$_{Curie}$/T$_C$ $\leq$ 0.92 is attribute to a delicate balance between the magnetic exchange energy and the condensation energy in the interfacial regions of the trilayer.Comment: 13 pages and 5 figure

Spectral and Thermal Studies of 1,10-Phenanthroline N,N\u27 -Dioxide Chelates of Oxovanadium(IV)

A new series of penta-coordinated oxovanadium{IV) chelates of 1,10-phenanthroline N,N\u27-dioxide (Phen02) have been synthesized and characterized by conductance, magnetic moments, infrared, electronic spectra and TG-data

Post stroke psychiatric syndrome: a clinical study

Background: Various psychiatric symptoms are seen after strokes which are usually deserted due to poor familiarity about it, hence better knowledge and understanding of various post stroke psychiatric manifestations may help in early identification and management of it. The aim of present research is to study the demographic and clinical profile of various post stroke psychiatric manifestations.Methods: The study was conducted on ninety patients developing psychiatric symptoms after stroke. Detailed socio-demographic characteristics, clinical profile along with psychiatric assessment were recorded in proforma specially designed for the study.Results: Bulk of this post- stroke psychiatric subjects (45%) was in the age range of 61-80 years of which male and female were 29% and 16% respectively.  Most of patients (90%) were residing at rural areas. 47.8 % patients were belonging to lower middle socio-economic status.  Majority of subjects (42.8%) were unemployed followed by farmer and skilled worker (20% each), and most of the patients were right handed (97.8%). On clinical parameters maximum subjects (52.2) developed post stroke major depression followed by depression mixed with anxiety (16.6%). Rest of patients suffered from organic anxiety disorder (8.8%), vascular dementia (10%), amnestic syndrome (5.5%), post stroke psychosis (3.3%), organic manic disorder (2.2%), pathological laughter and crying (1.1%).Conclusions: Huge number of patients (52.9%) developed psychiatric problems of diverse nature among patients with stroke syndrome. depression was most common post stroke psychiatric manifestation, followed by mixed anxiety with depression.  Generally the post stroke psychiatric manifestations are unrecognized and untreated, which has adverse impact on process of stroke rehabilitation. Thus a detailed psychiatric evaluation is mandatory in all patients of stroke syndrome to rule out psychiatric illness

The 5,6-Benzoquinoline N-Oxide Complexes of Oxovanadium(IV)

5,6-Benzoquinoline N-oxide (Benzquo) complexes of oxovanadium(IV) with the general composition VO(Benzquo)2X2 (X = Cl, Br, I, N03, NCS, 0.5 C204) and VO(Benzquo)4 (CI04h have been prepared and characterized. The chemical analyses, magnetic susceptibility, infrared and electronic spectra of the complexes are reported. The studies show that the complexes are five-coordinated and may have tetragonal pyramidal structures. Thermal properties of the complexes also are reported

Text Independent Open-Set Cell phone Identification

This paper discusses the application of speech signals that convey various pieces of information such as the identity of its speaker, the language spoken, and the linguistic information about the text being spoken etc. The rapid developments in technologies related to cell-phones have resulted in their much broader usage than mere talking devices used for making and receiving phone calls. User-generated audio recordings from cell phones can be very helpful in a number of forensic applications. This thesis proposes a novel system for open-set cell-phone identification from speech samples recorded using the cell-phone. The proposed system uses different features based on original speech recordings and classifies them using sequential minimal optimization (SMO) based Support vector machine (SVM) and Vector Quantization (VQ). The performance of the proposed system is tested on a customised databases extracted from pre-recorded speech content of twenty-two cell phones of different manufacturers. Closed-set cell-phone recognition systems abound, and the overwhelming majority of research in cell-phone recognition in the past has been limited to this task. A realistically viable system must be capable of dealing with the open-set task. This effort attacks the open-set task, identifying the best features to use, and proposes the use of a fuzzy classifier followed by hypothesis testing as a model for text-independent, open-set cell-phone recognition

Performance assessment of wheat genotypes based on the superiority index using additive main and multiplicative interaction effects and BLUP analysis

The simultaneous use of additive main and multiplicative interaction effects (AMMI) and best linear unbiased predictors (BLUP) has been reflected in the multi-location evaluation of trials for number of crops. The additional advantages of both these approaches would be combined in superiority index (SI) to have an edge over the commonly used approaches. The promising wheat genotypes had been considered under multi location trails in Peninsular zone of India during the cropping seasons of 2018-2019 and 2019-2020. The highly significant environmental effects contributed 44.1% & 35.3% of total sum of squares in the AMMI analysis, 20.6% & 26.2% were augmented by G × E interaction, while 10.8% & 7.5% were contributed by the genotypes.Wheat genotypes of UAS3001, MACS6222, GW322, and DDW48 expressed their superiority in BLUP values. Superiority indexes and adaptability measures had identified WHD964 and DDW48 genotypes for the second year of study. More than 75% variations among the considered measures were due to the first two interaction principal components (IPCA’s) under Biplot analysis. Number of superiority index measures were clustered with adaptability measures in the same quadrant. Superiority index, the weighted measure of yield and consistent performance of genotypes would be more appropriate for stability and adaptabilities studies