35,711 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

    Environmental Initiatives and Earnings Management

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    Purpose – The purpose of this paper is to provide initial evidence on the association between environmental initiatives and earnings management. Prior literature documents firms participating in environmental initiatives to report relatively stronger financial performance. Moreover, firms with superior performance have been shown to engage in greater levels of earnings management. A natural question that arises is to what extent do firms with environmental initiatives engage in earnings management to report better financial performance? Design/methodology/approach – The study draws on two theoretical frameworks, external monitoring and internal corporate culture, to predict an inverse association between environmental initiatives and earnings management. The authors test this prediction using an earnings management regression model, estimating discretionary accruals using the modified-Jones approach. Findings – The study finds that firms with environmental initiatives exhibit lower earnings management proxied by absolute and income-increasing total discretionary accruals. The authors further find pollution prevention and climate related initiatives to help explain this inverse association. The results imply that firms practising environmental responsibility report better financial performance, with the most likely reason being due to real economic performance rather than through earnings management techniques. Originality/value – This study provides initial evidence on the association between environmental initiatives and earnings management, an area of importance to all stakeholders in a market with increasing interest in corporate environmental performance and its implications

    Snow cover, snowmelt and runoff in the Himalayan River basins

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    Not withstanding the seasonal vagaries of both rainfall amount and snowcover extent, the Himalayan rivers retain their basic perennial character. However, it is the component of snowmelt yield that accounts for some 60 to 70 percent of the total annual flow volumes from Hamilayan watersheds. On this large hydropotential predominantly depends the temporal performance of hydropower generation and major irrigation projects. The large scale effects of Himalayan snowcover on the hydrologic responses of a few selected catchments in western Himalayas was studied. The antecedent effects of snowcover area on long and short term meltwater yields can best be analyzed by developing appropriate hydrologic models forecasting the pattern of snowmelt as a function of variations in snowcover area. It is hoped that these models would be of practical value in the management of water resources. The predictability of meltwater for the entire snowmelt season was studied, as was the concurrent flow variation in adjacent watersheds, and their hydrologic significance. And the applicability of the Snowmelt-Runoff Model for real time forecast of daily discharges during the major part of the snowmelt season is examined

    Applications of Two Dimensional Fractional Fourier-Mellin Transform to Differential Equations

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    Integral transforms play wide and important role in mathematical physics, theoretical physics. Fourier-Mellin transform is used in fields like electronics, agriculture, medical etc.nbspIt has applications as registration of images, watermarks, invariant pattern recognition, preprocessing of images.nbspIn this paper we have obtained the differential operator and and and*. Using it we have solved the differential equation of the type . Also an application of two-dimensional fractional Fourier-Mellin transform to differential equation is presented

    The stability of adaptive synchronization of chaotic systems

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    In past works, various schemes for adaptive synchronization of chaotic systems have been proposed. The stability of such schemes is central to their utilization. As an example addressing this issue, we consider a recently proposed adaptive scheme for maintaining the synchronized state of identical coupled chaotic systems in the presence of a priori unknown slow temporal drift in the couplings. For this illustrative example, we develop an extension of the master stability function technique to study synchronization stability with adaptive coupling. Using this formulation, we examine local stability of synchronization for typical chaotic orbits and for unstable periodic orbits within the synchronized chaotic attractor (bubbling). Numerical experiments illustrating the results are presented. We observe that the stable range of synchronism can be sensitively dependent on the adaption parameters, and we discuss the strong implication of bubbling for practically achievable adaptive synchronization.Comment: 21 pages, 6 figure

    Wave transmission across surface interfaces in lattice structures

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    Within the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface elastic properties. The main attention is paid to the transmittance and the reflectance of a wave across the interface. The presented results shed a light on the influence on surface waves of surface inhomogeneity in surface elastic properties such as grain and subgrain boundaries

    Adjoint Operators of Two Dimensional Fractional Fourier-Mellin Transform

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    Methods based on the Fourier transform and Mellin transform are used in virtually all areas of engineering and science and by virtually all engineers and scientists. These transform play a important role in signal processing, algorithm, watermarking, pattern recognition, correlators, navigation, vowel recognition, cryptographic scheme, quantum calculus, radar system and have applications in agriculture, medical stream, detection of watermark in images regardless of the scaling and rotation. In this paper we present an adjiont shifting operator, adjoint scaling operator and adjoint shifting-scaling operator of two dimensional fractional Fourier-Mellin transform. Also we discuss some transform formulae using adjoint differential operator
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