19,622 research outputs found

    Ecology and Equity in Rights to Land and Water: A Study in South-Eastern Palakkad in Kerala

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    This article explores the impact of the existing property rights regime over land and water on the sustainable and equitable management and use of these resources, in the context of changing irrigation practices in a paddy-growing area in the south-eastern part of the Palakkad district in Kerala, India. Since land rights determine rights to water in the area, the article discusses the changing rights regime over land, primarily after the implementation of land reforms in 1970. It shows how the implementation of land reforms and nationalization of private forests have paid little attention to the ecological context in which redistribution was taking place. As a result, while an agricultural-cum- forested landscape was divided into privately owned and government owned parcels, the ecological relationships between these different land use categories were ignored. In the same vein, land and water were treated as separate entities, with redistribution of land rights overlooking the distribution of water rights. The compartmentalized view of resources coupled with the consolidation of the private property regime has resulted in a situation where landowners exploit the resource without any consideration for its ecological characteristics and inter-resource linkages. The failure to view land and water in integration has precipitated inequitable access and unsustainable use of water. In addition, the availability of external water supplies and the introduction of energised pumping facilitate the enclosure of water within privately owned land parcels. The article concludes that a re-envisioning of rights to resources within the concerned ecological context is necessary if sustainable and equitable resource use and management are to be achieve

    Isolated and Dynamical Horizons and Their Applications

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    Over the past three decades, black holes have played an important role in quantum gravity, mathematical physics, numerical relativity and gravitational wave phenomenology. However, conceptual settings and mathematical models used to discuss them have varied considerably from one area to another. Over the last five years a new, quasi-local framework was introduced to analyze diverse facets of black holes in an unified manner. In this framework, evolving black holes are modeled by dynamical horizons and black holes in equilibrium by isolated horizons. We review basic properties of these horizons and summarize applications to mathematical physics, numerical relativity and quantum gravity. This paradigm has led to significant generalizations of several results in black hole physics. Specifically, it has introduced a more physical setting for black hole thermodynamics and for black hole entropy calculations in quantum gravity; suggested a phenomenological model for hairy black holes; provided novel techniques to extract physics from numerical simulations; and led to new laws governing the dynamics of black holes in exact general relativity

    On Distance Magic Harary Graphs

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    This paper establishes two techniques to construct larger distance magic and (a, d)-distance antimagic graphs using Harary graphs and provides a solution to the existence of distance magicness of legicographic product and direct product of G with C4, for every non-regular distance magic graph G with maximum degree |V(G)|-1.Comment: 12 pages, 1 figur

    Entropy production, energy loss and currents in adiabatically rocked thermal ratchets

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    We study the nature of currents, input energy and entropy production in different types of adiabatically rocked ratchets using the method of stochastic energetics. The currents exhibit a peak as a function of noise strength. We show that there is no underlying resonance or synchronisation phenomena in the dynamics of the particle with these current peaks. This follows from the analysis of energy loss in the medium. We also show that the maxima seen in current as well as the total entropy production are not directly correlated.Comment: 6 pages, 7 figures Minor corrections are mad

    Transport Coherence in Frictional Ratchets

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    We study the phenomena of noise induced transport in frictional ratchet systems. For this we consider a Brownian particle moving in a space dependent frictional medium in the presence of external white noise fluctuations. To get the directed transport, unlike in other ratchet models like flashing or rocking ratchets etc., we do not require the potential experienced by the particle to be asymmetric nor do we require the external fluctuations to be correlated. We have obtained analytical expressions for current and the diffusion coefficient. We show that the frictional ratchet do not exhibit a pronounced coherence in the transport in that the diffusion spread overshadows the accompanying directed transport in system with finite spatial extensions.Comment: Based on the poster presentation (by RK) at the Condensed Matter Days - 2003 held at Jadavpur University, Kolkata, India from 27-29 August 2003. Minor corrections have been don

    A Survey on Fixed Divisors

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    In this article, we compile the work done by various mathematicians on the topic of the fixed divisor of a polynomial. This article explains most of the results concisely and is intended to be an exhaustive survey. We present the results on fixed divisors in various algebraic settings as well as the applications of fixed divisors to various algebraic and number theoretic problems. The work is presented in an orderly fashion so as to start from the simplest case of Z,\Z, progressively leading up to the case of Dedekind domains. We also ask a few open questions according to their context, which may give impetus to the reader to work further in this direction. We describe various bounds for fixed divisors as well as the connection of fixed divisors with different notions in the ring of integer-valued polynomials. Finally, we suggest how the generalization of the ring of integer-valued polynomials in the case of the ring of n×nn \times n matrices over Z\Z (or Dedekind domain) could lead to the generalization of fixed divisors in that setting.Comment: Accepted for publication in Confluentes Mathematic
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