26,323 research outputs found

    Thermal annealing behaviour on electrical properties of Pd/Ru Schottky contacts on n-type GaN

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    We have investigated the electrical properties of Pd/Ru Schottky contacts on n-GaN as a function of annealing temperature by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Schottky barrier height of the as-deposited Pd/Ru contact is found to be 0.67 eV (I-V) and 0.79 eV (C-V), respectively. Measurements showed that the Schottky barrier height increased from 0.68 eV (I-V) and 0.80 eV (C-V) to 0.80 eV (I-V) and 0.96 eV (C-V) as the annealing temperature is varied from 200 Β°C to 300 Β°C. Upon annealing at 400 Β°C and 500 Β°C, the Schottky barrier height decreased to 0.73 eV (I-V) and 0.85 eV (C-V) and 0.72 eV (I-V) and 0.84 eV (C-V), respectively. It is noted that the barrier height further decreased to 0.59 eV (I-V) and 0.72 eV (C-V) when the contact is annealed at 600 Β°C. The change of Schottky barrier heights and ideality factors with annealing temperature may be due to the formation of interfacial compounds at the Ru/Pd/n-GaN interface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2788

    Cost of resource degradation externalities: A study of groundwater depletion in Andhra Pradesh

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    This paper looks in to the process of environmental degradation and the resultant externalities in the context of groundwater depletion in drought prone regions. The main objective here is to estimate the costs of groundwater depletion externalities and examine the costs and benefits from groundwater replenishing mechanisms in different ecological contexts. This study shows how groundwater exploitation in India is resulting in economic losses to individual farmers apart from ecological degradation. It is argued that policies towards strengthening the resource base (abatement mechanisms) and equitable distribution of the resource (property rights) would be beneficial, economically as well as ecologically. The cost-benefit comparison is in favour of investment in replenishment mechanisms such as irrigation tanks and percolation tanks. The situation of over extraction and the resultant environmental degradation is a consequence of lack of appropriate and adequate policies (policy failure) for managing the subsurface water resources. Hither to, groundwater policies (subsidised credit, power, etc) are in the nature of encouraging private initiatives in groundwater development. While these policies helped in promoting groundwater development in the regions where groundwater development was below potential, they have led to over exploitation of the resource in fragile resource regions. On the other hand, no attempts were made (at the policy level) to strengthen the natural resource base in terms of replenishing the water table. On the contrary, groundwater development is seen as a substitute for tanks, which are the main agents of replenishment.Environment, Degradation, Groundwater, Externalities, Costs, Andhra Pradesh, South India

    Costs of Resource Degradation Externalities - A Study of Groundwater Depletion in Andhra Pradesh

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    This paper looks in to the process of environmental degradation and the resultant externalities in the context of groundwater depletion in drought prone regions. The main objective here is to estimate the costs of groundwater depletion externalities and examine the costs and benefits from groundwater replenishing mechanisms in different ecological contexts. This study shows how groundwater exploitation in India is resulting in economic losses to individual farmers apart from ecological degradation. It is argued that policies towards strengthening the resource base (abatement mechanisms) and equitable distribution of the resource (property rights) would be beneficial, economically as well as ecologically. The cost-benefit comparison is in favour of investment in replenishment mechanisms such as irrigation tanks and percolation tanks. The situation of over extraction and the resultant environmental degradation is a consequence of lack of appropriate and adequate policies (policy failure) for managing the subsurface water resources. Hither to, groundwater policies (subsidised credit, power, etc) are in the nature of encouraging private initiatives in groundwater development. While these policies helped in promoting groundwater development in the regions where groundwater development was below potential, they have led to over exploitation of the resource in fragile resource regions. On the other hand, no attempts were made (at the policy level) to strengthen the natural resource base in terms of replenishing the water table. On the contrary, groundwater development is seen as a substitute for tanks, which are the main agents of replenishment.Environment, Degradation, groundwater, externalities, Costs, Andhra

    How Participatory is Participatory Irrigation Management (PIM)? A Study of Water User Associations (WUAs) in Andhra Pradesh

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    It is argued that the reason for the ills of irrigation management is the alienation of farmers from the process of planning and implementation. Often 'lack of political will' is identified as the main reason for the tardy progress in irrigation reforms at the state level. Andhra Pradesh has demonstrated the political will by initiating widespread irrigation reforms through legislation. This paper, based on the situation after six years of WUAs in existence, makes an attempt to provide a comprehensive view on the status and functioning of the Water Users' Associations in the State. It is argued that while substantial amounts of money were spent on the reform process, the money was used mainly for improving the ailing irrigation systems rather than strengthening the formal institutional structures. Though some benefits in terms of increased area under irrigation in canal systems and improved quality of irrigation is evident, the sustainability of these benefits is rather uncertain in the absence of efficient institutional structures. Despite the fact that WUAs are promoted as non-political institutions, 'elite capture' and political involvement dominate their functioning. And the present trend appears to be towards further politicization of these institutions. More importantly, even after six years of their existence devolution of powers to WUAs has not taken place, as most of the important functions like assessment, collection of water charges, sanctioning of works, etc., are still in the hands of the irrigation department. In the absence of devolution of powers the WUAs are aiming for political gains rather than improving the systems. It is argued that political will is a necessary but not a sufficient condition for making the WUAs autonomous and self-sufficient. Restructuring and reforming of the State irrigation departments and the bureaucracy is critical for effective and sustainable irrigation institutions.participatory, Irrigation Management, water, Andhra Pradesh
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