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

Women Reproductive Rights in India: Prospective Future.

Reproductive rights were established as a subset of the human rights. Parents have a basic human right to determine freely and responsibly the number and the spacing of their children. Issues regarding the reproductive rights are vigorously contested, regardless of the population’s socioeconomic level, religion or culture. Following review article discusses reproductive rights with respect to Indian context focusing on socio economic and cultural aspects. Also discusses sensitization of government and judicial agencies in protecting the reproductive rights with special focus on the protecting the reproductive rights of people with disability (mental illness and mental retardation)

Electron Donating Properties of Phenothiazine & Methylphenothiazine

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Equipartition of Current in Parallel Conductors on Cooling Through the Superconducting Transition

Our experiments show that for two or more pieces of a wire, of different lengths in general, combined in parallel and connected to a dc source, the current ratio evolves towards unity as the combination is cooled to the superconducting transition temperature Tc, and remains pinned at that value below it. This re-distribution of the total current towards equipartition without external fine tuning is a surprise. It can be physically understood in terms of a mechanism that involves the flux-flow resistance associated with the transport current in a wire of type-II superconducting material. It is the fact that the flux-flow resistance increases with current that drives the current division towards equipartition.Comment: Revised version of J.Phys. Condens.Matter; vol. 18(2006) L143-L147 14 pages including 3 figures; provided an explanation in terms of the physical mechanism of flux flow induced resistance that is proportional to the impressed current. We are adding a simple, physically robust derivation of our equipartition without taking resort to the minimum dissipation principl

Phase separation in transparent liquid-liquid miscibility gap systems

A program to be carried out on transparent liquid-phase miscibility gap materials was developed for the purpose of acquiring additional insight into the separation process occurring in these systems. The transparency feature allows the reaction to be viewed directly through light scattering and holographic methods

An overview of the current understanding of Gamma-ray Bursts in the Fermi era

Gamma-ray bursts are the most luminous explosions in the Universe, and their origin as well as mechanism are the focus of intense research and debate. More than three decades since their serendipitous discovery, followed by several breakthroughs from space-borne and ground-based observations, they remain one of the most interesting astrophysical phenomena yet to be completely understood. Since the launch of Fermi with its unprecedented energy band width spanning seven decades, the study of gamma-ray burst research has entered a new phase. Here we review the current theoretical understanding and observational highlights of gamma-ray burst astronomy and point out some of the potential promises of multi-wavelength observations in view of the upcoming ground based observational facilities.Comment: 45 pages, 18 figures; Special issue of the Bulletin of the Astronomical Society of India on Transients from Radio to Gamma rays, December, 2011, eds. D.J. Saikia and D.A. Gree

Fruit forage Integrated Systems for Diversification and other Ecosystem Services

The interspaces (alleyways) in fruit orchards are generally not utilized for cultivation of perennial forage crops by a majority of farmers. These alleyways are often occupied by weeds or kept bare or clean with repeated tillage. The weeds may act as alternate/collateral hosts, thereby harboring pests and pathogens that may harm the fruit trees. In addition to this, the frequent tillage may subject the soil to erosion losses. Intercropping of perennial forage grasses and/or legumes with fruit crops is thus beneficial for not only providing high quality forage but also for providing various ecosystem services.Owing to an ever burgeoning population, degraded grasslands,shortage of fodder, and inability of farmers to earmark adequate land for fodder production, it becomes imperative to exploit the interspaces in fruit orchards. Yield and quality of forages can be increased by cultivating forage grasses and legume species in appropriate mixtures. The present study was conducted in order to evaluate the performance of several perennial temperate forage grass/legume combinations as an effective approach for weed management, soil fertility enhancement, and increased forage resource availability in apple/almond-based horti-pastoral systems in the northwestern Himalayan region of India during 2015 to 2020. The treatments consisted of various temperate perennial grasses (tall fescue, orchard grass, little seed canary grass, and timothy) and temperate perennial legumes (red and white clover) arranged in a randomised block design with three replications. In apple-based hortipasture, maximum yields were obtained with tall fescue + red clover (12.1 t/ha dry fodder yield) followed by orchard grass + red clover (10.45 t/ha dry fodder yield). Data on the effect of forage crops on soil fertility showed that organic carbon (%) varied significantly in various combinations, with maximum soil organic carbon being observed in red clover + apple (0.92%) followed by white clover + apple (0.89%). However,minimum soil organic carbon was observed in control plot (clean cultivation). In the almond-based hortipastoral system, canary grass + red clover recorded maximum green fodder yield (46.90 t/ha) and dry fodder yield (12.56 t/ha) followed by tall fescue + red clover and orchard grass+ red clover combinations. The treatment canary grass + red clover + almond recorded minimum weed density (10.64 m-2) and maximum weed control efficiency (79.85%) compared to control plots (natural vegetation, 90.64 m-2). Therefore, for achieving complementary benefits of high quality fodder, soil fertility enhancement, and suppression of weeds, interculture of perennial grass-legume mixtures is recommended in fruit orchards

Observations on TeV gamma rays from Geminga and PSR 0950+08

The Geminga (2 CG 195+04) which exhibits a periodicity with a period of 59 to 60 s in its emission of X-rays, GeV gamma rays and TeV gamma rays was studied. During the winter of 1984 to 1985, this object was observed to see if it emits TeV gamma rays with a periodicity approx 60 s. The observations were carried out at two different sites separated by 11 Km with the Ooty Atmospheric Cerenkov Array split into two parts. Data were collected during clear moonless nights for a total duration of 15.3 hours spread over 2 months. Since the first time derivative of period is believed to be large and uncertain. The total data are subdivided into segments of duration not more than 3 days each to steer clear of the effects of P in the phase analysis. If TeV gamma ray signals are seen in each of these segments, it is possible to derive P from observed data