843 resultados para Conservation of resources theory


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Soil erosion is more detrimental and affects the chemical, physical and biological properties of the soil. Degradation of soil and water resources is a worldwide problem. Over the next two decades, it is expected that the world will need 17% more water to grow food for the increasing population in developing countries and that total water use will increase by 40%. The total land area subjected to human-induced soil degradation is estimated as 20 x 106 (km)2 Hence conservation of soil and water is essential for the subsistence of life. This can be made possible through sustainable watershed management. This thesis aims at investigating the condition under which sustainable watershed management is possible in Kerala, in South India. The research has been carried out in three stages. In the first stage a conceptual framework is formulated (Chapter 3) based on the relevant literature (Chapter 2) in the field of watershed management. In the second stage this framework is applied to two existing case studies in Kerala State (Chapter 4). In the third stage, the methodology is used to test out geo textile innovation (Chapter 5) in two field experiments (Chapter 6).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The extension of density functional theory (DFT) to include pairing correlations without formal violation of the particle-number conservation condition is described. This version of the theory can be considered as a foundation of the application of existing DFT plus pairing approaches to atoms, molecules, ultracooled and magnetically trapped atomic Fermi gases, and atomic nuclei where the number of particles is conserved exactly. The connection with Hartree-Fock-Bogoliubov (HFB) theory is discussed, and the method of quasilocal reduction of the nonlocal theory is also described. This quasilocal reduction allows equations of motion to be obtained which are much simpler for numerical solution than the equations corresponding to the nonlocal case. Our theory is applied to the study of some even Sn isotopes, and the results are compared with those obtained in the standard HFB theory and with the experimental ones.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study is important for the fact that it places the management dynamics of marine fisheries sector in the context of growing unrest of local communities over the emerging resource conflicts and degradation Economic crisis in small scale marine fisheries due to high operating cost continue to hinder the efforts towards conservation in many ways The migration of mechanized fleet as a response to profit maximization strategy of enterprises continues to be a threat to resource management Therefore this study explores how to revamp the small scale mechanized sector effectively and profitably to ensure rational allocation of resources The thesis attempts to examine how livelihood vulnerabilities of artisanal fish workers influence the crafting of management institutions Finally by combining insights of an institutional framework the study establishes the need for recognising the role of both formal and informal institutions in the management of marine fisheries in Kerala

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cement industry ranks 2nd in energy consumption among the industries in India. It is one of the major emitter of CO2, due to combustion of fossil fuel and calcination process. As the huge amount of CO2 emissions cause severe environment problems, the efficient and effective utilization of energy is a major concern in Indian cement industry. The main objective of the research work is to assess the energy cosumption and energy conservation of the Indian cement industry and to predict future trends in cement production and reduction of CO2 emissions. In order to achieve this objective, a detailed energy and exergy analysis of a typical cement plant in Kerala was carried out. The data on fuel usage, electricity consumption, amount of clinker and cement production were also collected from a few selected cement industries in India for the period 2001 - 2010 and the CO2 emissions were estimated. A complete decomposition method was used for the analysis of change in CO2 emissions during the period 2001 - 2010 by categorising the cement industries according to the specific thermal energy consumption. A basic forecasting model for the cement production trend was developed by using the system dynamic approach and the model was validated with the data collected from the selected cement industries. The cement production and CO2 emissions from the industries were also predicted with the base year as 2010. The sensitivity analysis of the forecasting model was conducted and found satisfactory. The model was then modified for the total cement production in India to predict the cement production and CO2 emissions for the next 21 years under three different scenarios. The parmeters that influence CO2 emissions like population and GDP growth rate, demand of cement and its production, clinker consumption and energy utilization are incorporated in these scenarios. The existing growth rate of the population and cement production in the year 2010 were used in the baseline scenario. In the scenario-1 (S1) the growth rate of population was assumed to be gradually decreasing and finally reach zero by the year 2030, while in scenario-2 (S2) a faster decline in the growth rate was assumed such that zero growth rate is achieved in the year 2020. The mitigation strategiesfor the reduction of CO2 emissions from the cement production were identified and analyzed in the energy management scenarioThe energy and exergy analysis of the raw mill of the cement plant revealed that the exergy utilization was worse than energy utilization. The energy analysis of the kiln system showed that around 38% of heat energy is wasted through exhaust gases of the preheater and cooler of the kiln sysetm. This could be recovered by the waste heat recovery system. A secondary insulation shell was also recommended for the kiln in the plant in order to prevent heat loss and enhance the efficiency of the plant. The decomposition analysis of the change in CO2 emissions during 2001- 2010 showed that the activity effect was the main factor for CO2 emissions for the cement industries since it is directly dependent on economic growth of the country. The forecasting model showed that 15.22% and 29.44% of CO2 emissions reduction can be achieved by the year 2030 in scenario- (S1) and scenario-2 (S2) respectively. In analysing the energy management scenario, it was assumed that 25% of electrical energy supply to the cement plants is replaced by renewable energy. The analysis revealed that the recovery of waste heat and the use of renewable energy could lead to decline in CO2 emissions 7.1% for baseline scenario, 10.9 % in scenario-1 (S1) and 11.16% in scenario-2 (S2) in 2030. The combined scenario considering population stabilization by the year 2020, 25% of contribution from renewable energy sources of the cement industry and 38% thermal energy from the waste heat streams shows that CO2 emissions from Indian cement industry could be reduced by nearly 37% in the year 2030. This would reduce a substantial level of greenhouse gas load to the environment. The cement industry will remain one of the critical sectors for India to meet its CO2 emissions reduction target. India’s cement production will continue to grow in the near future due to its GDP growth. The control of population, improvement in plant efficiency and use of renewable energy are the important options for the mitigation of CO2 emissions from Indian cement industries

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Kr 4s-electron photoionization cross section as a function of the exciting-photon energy in the range between 30 eV and 90 eV was calculated using the configuration interaction (CI) technique in intermediate coupling. In the calculations the 4p spin-orbital interaction and corrections due to higher orders of perturbation theory (the so-called Coulomb interaction correlational decrease) were considered. Energies of Kr II states were calculated and agree with spectroscopic data within less than 10 meV. For some of the Kr II states new assignments were suggested on the basis of the largest component among the calculated CI wavefunctions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The structural, electronic and magnetic properties of one-dimensional 3d transition-metal (TM) monoatomic chains having linear, zigzag and ladder geometries are investigated in the frame-work of first-principles density-functional theory. The stability of long-range magnetic order along the nanowires is determined by computing the corresponding frozen-magnon dispersion relations as a function of the 'spin-wave' vector q. First, we show that the ground-state magnetic orders of V, Mn and Fe linear chains at the equilibrium interatomic distances are non-collinear (NC) spin-density waves (SDWs) with characteristic equilibrium wave vectors q that depend on the composition and interatomic distance. The electronic and magnetic properties of these novel spin-spiral structures are discussed from a local perspective by analyzing the spin-polarized electronic densities of states, the local magnetic moments and the spin-density distributions for representative values q. Second, we investigate the stability of NC spin arrangements in Fe zigzag chains and ladders. We find that the non-collinear SDWs are remarkably stable in the biatomic chains (square ladder), whereas ferromagnetic order (q =0) dominates in zigzag chains (triangular ladders). The different magnetic structures are interpreted in terms of the corresponding effective exchange interactions J(ij) between the local magnetic moments μ(i) and μ(j) at atoms i and j. The effective couplings are derived by fitting a classical Heisenberg model to the ab initio magnon dispersion relations. In addition they are analyzed in the framework of general magnetic phase diagrams having arbitrary first, second, and third nearest-neighbor (NN) interactions J(ij). The effect of external electric fields (EFs) on the stability of NC magnetic order has been quantified for representative monoatomic free-standing and deposited chains. We find that an external EF, which is applied perpendicular to the chains, favors non-collinear order in V chains, whereas it stabilizes the ferromagnetic (FM) order in Fe chains. Moreover, our calculations reveal a change in the magnetic order of V chains deposited on the Cu(110) surface in the presence of external EFs. In this case the NC spiral order, which was unstable in the absence of EF, becomes the most favorable one when perpendicular fields of the order of 0.1 V/Å are applied. As a final application of the theory we study the magnetic interactions within monoatomic TM chains deposited on graphene sheets. One observes that even weak chain substrate hybridizations can modify the magnetic order. Mn and Fe chains show incommensurable NC spin configurations. Remarkably, V chains show a transition from a spiral magnetic order in the freestanding geometry to FM order when they are deposited on a graphene sheet. Some TM-terminated zigzag graphene-nanoribbons, for example V and Fe terminated nanoribbons, also show NC spin configurations. Finally, the magnetic anisotropy energies (MAEs) of TM chains on graphene are investigated. It is shown that Co and Fe chains exhibit significant MAEs and orbital magnetic moments with in-plane easy magnetization axis. The remarkable changes in the magnetic properties of chains on graphene are correlated to charge transfers from the TMs to NN carbon atoms. Goals and limitations of this study and the resulting perspectives of future investigations are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El incumplimiento reiterado de la normatividad y políticas relacionadas con los tiempos de respuesta del proceso de contratación minera del país, desarrollado actualmente por la recién creada Agencia Nacional de Minería ANM, ha suscitado que la administración del recurso minero no se realice bajo los principios de eficiencia, eficacia, economía y celeridad. Estas debilidades manifiestas provocan represamientos en la resolución de trámites, congelación de áreas para contratar, sobrecostos, demoras en los tiempos de respuesta establecidos por la normatividad vigente y trae como consecuencia incertidumbre en los inversionistas mineros y pérdidas por concepto de recaudo de canon superficiario, entre otras. El objetivo del presente trabajo de investigación consiste en analizar el proceso de titulación minera de Colombia a partir de la filosofía de mejora continua desarrollado en la teoría de restricciones TOC (Theory Of Constraints), para poder identificar cuáles son los cuellos de botella que no permiten que el proceso fluya de manera adecuada y proponer alternativas de mejora, que con su implementación exploten y subordinen la limitaciones al sistema.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Con la creciente popularidad de las soluciones de IT como factor clave para aumentar la competitividad y la creación de valor para las empresas, la necesidad de invertir en proyectos de IT se incrementa considerablemente. La limitación de los recursos como un obstáculo para invertir ha obligado a las empresas a buscar metodologías para seleccionar y priorizar proyectos, asegurándose de que las decisiones que se toman son aquellas que van alineadas con las estrategias corporativas para asegurar la creación de valor y la maximización de los beneficios. Esta tesis proporciona los fundamentos para la implementación del Portafolio de dirección de Proyectos de IT (IT PPM) como una metodología eficaz para la gestión de proyectos basados en IT, y una herramienta para proporcionar criterios claros para los directores ejecutivos para la toma de decisiones. El documento proporciona la información acerca de cómo implementar el IT PPM en siete pasos, el análisis de los procesos y las funciones necesarias para su ejecución exitosa. Además, proporciona diferentes métodos y criterios para la selección y priorización de proyectos. Después de la parte teórica donde se describe el IT PPM, la tesis aporta un análisis del estudio de caso de una empresa farmacéutica. La empresa ya cuenta con un departamento de gestión de proyectos, pero se encontró la necesidad de implementar el IT PPM debido a su amplia cobertura de procesos End-to-End en Proyectos de IT, y la manera de asegurar la maximización de los beneficios. Con la investigación teórica y el análisis del estudio de caso, la tesis concluye con una definición práctica de un modelo aproximado IT PPM como una recomendación para su implementación en el Departamento de Gestión de Proyectos.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

What are the effects of natural disasters on electoral results? Some authors claim that catastrophes have a negative effect on the survival of leaders in a democracy because voters have a propensity to punish politicians for not preventing or poorly handling a crisis. In contrast, this paper finds that these events might be beneficial for leaders. Disasters are linked to leader survival through clientelism: they generate an in-flow of resources in the form of aid, which increase money for buying votes. Analyzing the rainy season of 2010-2011 in Colombia, considered its worst disaster in history, I use a difference-in-differences strategy to show that in the local election incumbent parties benefited from the disaster. The result is robust to different specifications and alternative explanations. Moreover, places receiving more aid and those with judicial evidence of vote-buying irregularities, are more likely to reelect the incumbent, supporting the mechanism proposed by this paper.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Este documento presenta una visión amplia de la Teoría de Integración Económica desde el punto de vista de la teoría de unión aduanera. Se argumenta que dicha teoría carece de integración y que los recientes desarrollos en el tema no parecen resolver esta falla. A pesar de esto, se sugiere que los desarrollos teóricos surgidos a partir del trabajo seminal de Viner y posteriormente desarrollados por otros teóricos, son aún útiles como herramienta de investigación empírica en el tema.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study examined culturally and linguistically diverse families with deaf and hard of hearing children. A literature review consisted of looking at the rate of immigration to the United States, English speaking parents of children who are deaf and hard of hearing, bilingual education, and the obstacles bilingual parents of children who are deaf and hard of hearing may face. The data obtained was used to compile a list of resources for parents of children who are deaf and hard of hearing available in languages other than English in order to assist these families.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Understanding the effect of habitat fragmentation is a fundamental yet complicated aim of many ecological studies. Beni savanna is a naturally fragmented forest habitat, where forest islands exhibit variation in resources and threats. To understand how the availability of resources and threats affect the use of forest islands by parrots, we applied occupancy modeling to quantify use and detection probabilities for 12 parrot species on 60 forest islands. The presence of urucuri (Attalea phalerata) and macaw (Acrocomia aculeata) palms, the number of tree cavities on the islands, and the presence of selective logging,and fire were included as covariates associated with availability of resources and threats. The model-selection analysis indicated that both resources and threats variables explained the use of forest islands by parrots. For most species, the best models confirmed predictions. The number of cavities was positively associated with use of forest islands by 11 species. The area of the island and the presence of macaw palm showed a positive association with the probability of use by seven and five species, respectively, while selective logging and fire showed a negative association with five and six species, respectively. The Blue-throated Macaw (Ara glaucogularis), the critically endangered parrot species endemic to our study area, was the only species that showed a negative association with both threats. Monitoring continues to be essential to evaluate conservation and management actions of parrot populations. Understanding of how species are using this natural fragmented habitat will help determine which fragments should be preserved and which conservation actions are needed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A new method of clear-air turbulence (CAT) forecasting based on the Lighthill–Ford theory of spontaneous imbalance and emission of inertia–gravity waves has been derived and applied on episodic and seasonal time scales. A scale analysis of this shallow-water theory for midlatitude synoptic-scale flows identifies advection of relative vorticity as the leading-order source term. Examination of leading- and second-order terms elucidates previous, more empirically inspired CAT forecast diagnostics. Application of the Lighthill–Ford theory to the Upper Mississippi and Ohio Valleys CAT outbreak of 9 March 2006 results in good agreement with pilot reports of turbulence. Application of Lighthill–Ford theory to CAT forecasting for the 3 November 2005–26 March 2006 period using 1-h forecasts of the Rapid Update Cycle (RUC) 2 1500 UTC model run leads to superior forecasts compared to the current operational version of the Graphical Turbulence Guidance (GTG1) algorithm, the most skillful operational CAT forecasting method in existence. The results suggest that major improvements in CAT forecasting could result if the methods presented herein become operational.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article is about the politics of conservation in postcolonial Southern Africa. It focuses on the process and consequences of redefining the Nile crocodile as an endangered species and explores the linked local and international, commercial and conservationist interests that allowed the animal to re-establish itself in state-protected waterways in colonial and postcolonial contexts. It investigates the effects of the animal's successful re-accommodation by examining conflicts between crocodiles and the fishing communities sharing space on Lake Kariba, Zimbabwe. Fishermen's hostile representations of the animal emphasize competition for fish, harassment, fear, loss of assets and loss of life. Their fear of crocodiles is heightened by the animal's entanglement in local social life, through its association with witchcraft. The article emphasizes the importance of considering both hegemonic and marginalized ideas about animals in the light of the material interactions, relations of power and historical contexts that shape them. Understanding the attitudes and circumstances of the local communities who bear the physical and economic costs of living with dangerous animals is important-it threatens the future of conservation programmes and reveals the potential for significant abuses to accompany the conservation of wildlife in postcolonial contexts. © 2004 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Slantwise convective available potential energy (SCAPE) is a measure of the degree to which the atmosphere is unstable to conditional symmetric instability (CSI). It has, until now, been defined by parcel theory in which the atmosphere is assumed to be nonevolving and balanced, that is, two-dimensional. When applying this two-dimensional theory to three-dimensional evolving flows, these assumptions can be interpreted as an implicit assumption that a timescale separation exists between a relatively rapid timescale for slantwise ascent and a slower timescale for the development of the system. An approximate extension of parcel theory to three dimensions is derived and it is shown that calculations of SCAPE based on the assumption of relatively rapid slantwise ascent can be qualitatively in error. For a case study example of a developing extratropical cyclone, SCAPE calculated along trajectories determined without assuming the existence of the timescale separation show large SCAPE values for parcels ascending from the warm sector and along the warm front. These parcels ascend into the cloud head within which there is some evidence consistent with the release of CSI from observational and model cross sections. This region of high SCAPE was not found for calculations along the relatively rapidly ascending trajectories determined by assuming the existence of the timescale separation.