61,279 research outputs found

    Magnetization in electron- and Mn- doped SrTiO3

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    Mn-doped SrTiO_3.0, when synthesized free of impurities, is a paramagnetic insulator with interesting dielectric properties. Since delocalized charge carriers are known to promote ferromagnetism in a large number of systems via diverse mechanisms, we have looked for the possibility of any intrinsic, spontaneous magnetization by simultaneous doping of Mn ions and electrons into SrTiO_3 via oxygen vacancies, thereby forming SrTi_(1-x)Mn_xO_(3-d), to the extent of making the doped system metallic. We find an absence of any enhancement of the magnetization in the metallic sample when compared with a similarly prepared Mn doped, however, insulating sample. Our results, thus, are not in agreement with a recent observation of a weak ferromagnetism in metallic Mn doped SrTiO_3 system.Comment: 10 pages and 4 figure

    Anomalies at finite density and chiral fermions

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    Using perturbation theory in the Euclidean (imaginary time) formalism as well as the non-perturbative Fujikawa method, we verify that the chiral anomaly equation remains unaffected in the presence of nonzero chemical potential, μ\mu. We extend our considerations to fermions with exact chiral symmetry on the lattice and discuss the consequences for the recent Bloch-Wettig proposal for the Dirac operator at finite chemical potential. We propose a new simpler method of incorporating μ\mu and compare it with the Bloch-Wettig idea.Comment: 12 pages, 3 figures,some typos corrected, a better proof for the \mu independence of anomaly is given in section IIB, v4: the published versio

    Comparative Statistical Analysis of Some Hydrobiological Parameters in Upstream and Downstream of River Asan

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    Today world is facing a number of challenges affecting the availability, accessibility, use and sustainability of its freshwater resources. Water is the most vital resource for living beings because there is no life without water as cellular activities never occur. Water is essential for the socio-economic development of human beings. Industrialization, urbanization, population explosion and green revolution have deteriorated the various sources of water. Keeping these points in mind, this study is designed to comparatively analyze the water quality of river Asan at upstream and downstream sites

    Magneto-Seebeck effect in spin-valve with in-plane thermal gradient

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    We present measurements of magneto-Seebeck effect on a spin valve with in-plane thermal gradient. We measured open circuit voltage and short circuit current by applying a temperature gradient across a spin valve stack, where one of the ferromagnetic layers is pinned. We found a clear hysteresis in these two quantities as a function of magnetic field. From these measurements, the magneto-Seebeck effect was found to be 0.82%.Comment: 10 Pages, 7 figure

    A Constitutive Modeling and Experimental Effect of Shock Wave on the Microstructural Sub-strengthening of Granular Copper

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    Micro-sized copper powder (99.95%; O≤0.3) has been shock-processed with explosives of high detonation velocities of the order of 7.5km/s to observe the structural and microstructural sub-strengthening. Axisymmetric shock-consolidation technique has been used to obtain conglomerates of granular Cu. The technique involves the cylindrical compaction system wherein the explosive-charge is in direct proximity with the powder whereas the other uses indirect shock pressure with die-plunger geometry. Numeric simulations have been performed on with Eulerian code dynamics. The simulated results show a good agreement with the experimental observation of detonation parameters like detonation velocity, pressure, particle velocity and shock pressure in the reactive media. A pin contactor method has been utilized to calculate the detonation pressure experimentally. Wide angled x-ray diffraction studies reveal that the crystalline structure (FCC) of the shocked specimen matches with the un-shocked specimen. Field emissive scanning electron microscopic examination of the compacted specimens show a good sub-structural strengthening and complement the theoretical considerations. Laser diffraction based particle size analyzer also points towards the reduced particle size of the shock-processed specimen under high detonation velocities. Micro-hardness tests conducted under variable loads of 0.1kg, 0.05kg and 0.025kg force with diamond indenter optical micrographs indicate a high order of micro-hardness of the order of 159Hv. Nitrogen pycnometry used for the density measurement of the compacts shows that a compacted density of the order of 99.3% theoretical mean density has been achieved

    Ionospheric simulator survey

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    Evaluation of D and E region ionospheric simulation technique

    The BCS theory of q-deformed nucleon pairs - qBCS

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    We construct a coherent state of q-deformed zero coupled nucleon pairs distributed in several single-particle orbits. Using a variational approach, the set of equations of qBCS theory, to be solved self consistently for occupation probabilities, gap parameter Delta, and the chemical potential lambda, is obtained. Results for valence nucleons in nuclear degenerate sdg major shell show that the strongly coupled zero angular momentum nucleon pairs can be substituted by weakly coupled q-deformed zero angular momentum nucleon pairs. A study of Sn isotopes reveals a well defined universe of (G, q) values, for which qBCS converges. While the qBCS and BCS show similar results for Gap parameter Delta in Sn isotopes, the ground state energies are lower in qBCS. The pairing correlations in N nucleon system, increase with increasing q (for q real).Comment: 8 pages, REVTEX, 3 eps figure

    Driven diffusive systems with mutually interactive Langmuir kinetics

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    We investigate the simple one-dimensional driven model, the totally asymmetric exclusion process, coupled to mutually interactive Langmuir kinetics. This model is motivated by recent studies on clustering of motor proteins on microtubules. In the proposed model, the attachment and detachment rates of a particle are modified depending upon the occupancy of neighbouring sites. We first obtain continuum mean-field equations and in certain limiting cases obtain analytic solutions. We show how mutual interactions increase (decrease) the effects of boundaries on the phase behavior of the model. We perform Monte Carlo simulations and demonstrate that our analytical approximations are in good agreement with the numerics over a wide range of model parameters. We present phase diagrams over a selective range of parameters.Comment: 9 pages, 8 Figure

    Specialty Preference Among Medical Students and Factors Affecting It

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    Introduction: Medical education is one of the core part of educational system of any country. Medical education requires undergraduate students to study a wide range of medical specialties. It is often assumed that students do not make their career preferences until after they have graduated from medical school. So the reasons and factors responsible for preferences need to be found out among medical students. Material and Methods: It was a Cross sectional study on 180 medical students to assess preference for specialty and factors responsible. Results: Out of total 190 medical students more or less everyone (97.89%) wanted to pursue specialization and majority of them (96.84%) wanted to pursue the same in Medical Field(p>0.05). majority of male students were interested to pursue their specialization in the field of medicine (37.63%), surgery (23.65%) and pediatrics (13.97%). On the other hand female students were more interested in medicine (24.17%), pediatrics (32.96%) and obstetrics & gynecology (24.17%)(p<0.05). Interest, by far was found to be most common factor (76.63%) responsible for the preference of particular medical specialty among all four groups of students (1st professional-25.27%, 2nd professional-75.92%, final professional-89.47%, interns-68.42%).Conclusion: It is thus concluded there are many factors playing role in the specialty selection and preference among the medical students and should be equally justified and addressed
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