1,929 research outputs found

    Studies on morphometry and hydrology of Gandhisagar Reservoir with special reference to its fisheries

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    Gandhisagar, the second largest reservoir of India is located in Mandsaur district of Madhya Pradesh at latitude 24°44'N and longitude 75°33'E at an altitude of 403.56m MSL in orientation from NE to SE. It has an extensive water spread area of 66000 ha at full reservoir level with a maximum and mean depth of 49.52 and 11.73 m respectively. The maximum length and width of the reservoir are 112 and 16km having a total shore line of 442km. Details of catchment area, bathymetry, standard hydrological data giving water level relation of the basin to water spread area, volume and fish production and the bottom topographical details of 11 experimental fishing stations and 6 fish landing centres are discussed

    Contamination of Asian herbal drugs : Need for its critical evaluation

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    Herbal drugs have been used as remedies for the treatment of large number of humans, ailments since ancient times as the traditional medicine system; India has a glorious past, having first documented record of fully developed medical science known as Ayurveda written by several ancient Rishi’s. Major groups of indigenous system of medicine are based on herbal drugs. A survey made by WHO indicated that about 80% of the world population relies on herbal drugs. Herbal drugs are becoming more popularized and important even in the developednations with hope of their non-toxicity and may play a role of substitute to overcome the problems of multi drug resistant pathogens. Cultivation of drug plants has been started in large scale without considering the land quality and in certain cases irrigation with waste water. Application of different fungicides, pesticides in that specific field or in neighboring fields may be directly deposited superficially or may be absorbed by the plant system. Therefore in the present situation possibilities of the Asian herbal drugs, contaminated with large number of toxic components cannot be ignored which may severely hurt human life in place of healing or curing.These contaminants may be either alone or in combination and may be originated intrinsically, extrinsically and deliberately. Certain contaminants may be highly toxic and may cause severe adverse effect in the human system. Some of the important contaminants are the heavy metals like lead, arsenic, cadmium, mercury, copper and pesticides. Adulteration of modern drugs to enhance drug potency and heterogenous microbial population including human pathogens may contaminate both raw and powdered herbal drugs. Among these contaminants, microbial contamination seems more severe and may be due to their dual action on the drug i.e. utilization of medicinally important chemical components as nutrients and in certain cases by producing certain mycotoxins, which may be even carcinogenic under certain conditions . Critical evaluation of both raw and powdered herbal drugs for contaminants is the urgent need of the time in order to provide safety measures in herbal health care medicine

    Massive gravity as a quantum gauge theory

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    We present a new point of view on the quantization of the massive gravitational field, namely we use exclusively the quantum framework of the second quantization. The Hilbert space of the many-gravitons system is a Fock space F+(Hgraviton){\cal F}^{+}({\sf H}_{\rm graviton}) where the one-particle Hilbert space Hgraviton{\sf H}_{graviton} carries the direct sum of two unitary irreducible representations of the Poincar\'e group corresponding to two particles of mass m>0m > 0 and spins 2 and 0, respectively. This Hilbert space is canonically isomorphic to a space of the type Ker(Q)/Im(Q)Ker(Q)/Im(Q) where QQ is a gauge charge defined in an extension of the Hilbert space Hgraviton{\cal H}_{\rm graviton} generated by the gravitational field hμνh_{\mu\nu} and some ghosts fields uμ,u~μu_{\mu}, \tilde{u}_{\mu} (which are vector Fermi fields) and vμv_{\mu} (which are vector field Bose fields.) Then we study the self interaction of massive gravity in the causal framework. We obtain a solution which goes smoothly to the zero-mass solution of linear quantum gravity up to a term depending on the bosonic ghost field. This solution depends on two real constants as it should be; these constants are related to the gravitational constant and the cosmological constant. In the second order of the perturbation theory we do not need a Higgs field, in sharp contrast to Yang-Mills theory.Comment: 35 pages, no figur

    Goodness-of-Fit Tests to study the Gaussianity of the MAXIMA data

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    Goodness-of-Fit tests, including Smooth ones, are introduced and applied to detect non-Gaussianity in Cosmic Microwave Background simulations. We study the power of three different tests: the Shapiro-Francia test (1972), the uncategorised smooth test developed by Rayner and Best(1990) and the Neyman's Smooth Goodness-of-fit test for composite hypotheses (Thomas and Pierce 1979). The Smooth Goodness-of-Fit tests are designed to be sensitive to the presence of ``smooth'' deviations from a given distribution. We study the power of these tests based on the discrimination between Gaussian and non-Gaussian simulations. Non-Gaussian cases are simulated using the Edgeworth expansion and assuming pixel-to-pixel independence. Results show these tests behave similarly and are more powerful than tests directly based on cumulants of order 3, 4, 5 and 6. We have applied these tests to the released MAXIMA data. The applied tests are built to be powerful against detecting deviations from univariate Gaussianity. The Cholesky matrix corresponding to signal (based on an assumed cosmological model) plus noise is used to decorrelate the observations previous to the analysis. Results indicate that the MAXIMA data are compatible with Gaussianity.Comment: MNRAS, in pres

    Combined surgical and prosthetic approach for rehabilitation of frontonasal defect using custom made titanium implant: a case report

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    Cranial vault deformities as a sequelae to trauma may be as high as 70%. The basic indications for cranioplasty are improvement of disfigured aesthetics and to provide protection to the intra-cranial contents. The possibility of producing custom-made implants opened a new era in the reconstructive surgery of the craniofacial deformities. The outcome of craniofacial bone reconstruction is thought to be dependent on surgical skills, quality of adjacent soft tissues, size and location of the bone defect and choice of repair method. The use of autologous bone for craniofacial reconstruction may be restricted due to limited amounts of donor bone. Combined surgical and prosthetic rehabilitation of these structures utilizing craniofacial implants is a viable option which offers several advantages when compared to surgical reconstructive techniques alone. Predictability and superior aesthetics are the major advantages of this technique. In addition to the advantages of good biocompatibility and mechanical strength, titanium also provides the advantage of being light in weight. This clinical report highlights the combined surgical and prosthetic approach for the successful management of frontonasal defect

    Frustrated two-dimensional Josephson junction array near incommensurability

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    To study the properties of frustrated two-dimensional Josephson junction arrays near incommensurability, we examine the current-voltage characteristics of a square proximity-coupled Josephson junction array at a sequence of frustrations f=3/8, 8/21, 0.382 ((35)/2)(\approx (3-\sqrt{5})/2), 2/5, and 5/12. Detailed scaling analyses of the current-voltage characteristics reveal approximately universal scaling behaviors for f=3/8, 8/21, 0.382, and 2/5. The approximately universal scaling behaviors and high superconducting transition temperatures indicate that both the nature of the superconducting transition and the vortex configuration near the transition at the high-order rational frustrations f=3/8, 8/21, and 0.382 are similar to those at the nearby simple frustration f=2/5. This finding suggests that the behaviors of Josephson junction arrays in the wide range of frustrations might be understood from those of a few simple rational frustrations.Comment: RevTex4, 4 pages, 4 eps figures, to appear in Phys. Rev.

    Isospin Effects in Nuclear Multifragmentation

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    We develop an improved Statistical Multifragmentation Model that provides the capability to calculate calorimetric and isotopic observables with precision. With this new model we examine the influence of nuclear isospin on the fragment elemental and isotopic distributions. We show that the proposed improvements on the model are essential for studying isospin effects in nuclear multifragmentation. In particular, these calculations show that accurate comparisons to experimental data require that the nuclear masses, free energies and secondary decay must be handled with higher precision than many current models accord.Comment: 46 pages, 16 figure

    Flux-lattice melting in two-dimensional disordered superconductors

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    The flux line lattice melting transition in two-dimensional pure and disordered superconductors is studied by a Monte Carlo simulation using the lowest Landau level approximation and quasi-periodic boundary condition on a plane. The position of the melting line was determined from the diffraction pattern of the superconducting order parameter. In the clean case we confirmed the results from earlier studies which show the existence of a quasi-long range ordered vortex lattice at low temperatures. Adding frozen disorder to the system the melting transition line is shifted to slightly lower fields. The correlations of the order parameter for translational long range order of the vortex positions seem to decay slightly faster than a power law (in agreement with the theory of Carpentier and Le Doussal) although a simple power law decay cannot be excluded. The corresponding positional glass correlation function decays as a power law establishing the existence of a quasi-long range ordered positional glass formed by the vortices. The correlation function characterizing a phase coherent vortex glass decays however exponentially ruling out the possible existence of a phase coherent vortex glass phase.Comment: 12 pages, 21 figures, final version to appear in Phys. Rev.

    Multiband tight-binding theory of disordered ABC semiconductor quantum dots: Application to the optical properties of alloyed CdZnSe nanocrystals

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    Zero-dimensional nanocrystals, as obtained by chemical synthesis, offer a broad range of applications, as their spectrum and thus their excitation gap can be tailored by variation of their size. Additionally, nanocrystals of the type ABC can be realized by alloying of two pure compound semiconductor materials AC and BC, which allows for a continuous tuning of their absorption and emission spectrum with the concentration x. We use the single-particle energies and wave functions calculated from a multiband sp^3 empirical tight-binding model in combination with the configuration interaction scheme to calculate the optical properties of CdZnSe nanocrystals with a spherical shape. In contrast to common mean-field approaches like the virtual crystal approximation (VCA), we treat the disorder on a microscopic level by taking into account a finite number of realizations for each size and concentration. We then compare the results for the optical properties with recent experimental data and calculate the optical bowing coefficient for further sizes

    Renormalized Path Integral for the Two-Dimensional Delta-Function Interaction

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    A path-integral approach for delta-function potentials is presented. Particular attention is paid to the two-dimensional case, which illustrates the realization of a quantum anomaly for a scale invariant problem in quantum mechanics. Our treatment is based on an infinite summation of perturbation theory that captures the nonperturbative nature of the delta-function bound state. The well-known singular character of the two-dimensional delta-function potential is dealt with by considering the renormalized path integral resulting from a variety of schemes: dimensional, momentum-cutoff, and real-space regularization. Moreover, compatibility of the bound-state and scattering sectors is shown.Comment: 26 pages. The paper was significantly expanded and numerous equations were added for the sake of clarity; the main results and conclusions are unchange
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