50 research outputs found

    Submergence effects on jet behavior in scour by a plane wall jet

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    In this study, the effects of submergence on local scour in a uniform cohesionless sediment bed by a plane turbulent wall jet and the resulting flow field were investigated experimentally. Here, submergence is defined as the ratio of the tailwater depth to the thickness of the jet at its origin. The main focus was to determine scour dimensions at an asymptotic state, examine whether there was similarity in the velocity profiles for the flow in the scour hole, and to determine the growth of the length scales and decay of the maximum velocity of the jet. Also examined were the relationships between the scales for the velocity field in the scour hole and the scour hole size.In the experiments, the range of submergence was varied from 3-17.5, whereas the range of densimetric Froude number and the ratio of the boundary roughness to the gate opening (relative boundary roughness) were varied from 4.4-6.9 and 0.085-0.137 respectively. The velocity field in the scour hole at asymptotic state was measured using a SonTek 16-MHz MicroADV. Time development of the characteristic dimensions of the scour hole was also measured.The dimensions of the scour hole were found to increase with increasing submergence for all experiments with a “bed-jet” flow regime. In the bed-jet flow regime, the jet remains near the bed throughout the scouring process. Further, the time development of the scour hole dimensions were observed to increase approximately linearly with the logarithm of time up to a certain time before the beginning of asymptotic state for experiments with either the bed-jet or surface-jet flow regimes. The flow field results showed that the velocity profiles in the region of forward flow and the recirculating region above the jet were similar in shape up to about the location of the maximum scour depth. Relationships describing this velocity profile, including its velocity and length scales, were formulated. The decay rate of the maximum velocity, the growth of the jet half-width, and the boundary layer thickness were also studied. The decay and the growth rate of the jet length scales were found to be influenced by the submergence ratio, densimetric Froude number, and the relative boundary roughness.Two distinct stages in the decay of the maximum streamwise velocity, with distance along the direction of flow, were observed for the jet flows having a bed-jet flow regime. The first stage of velocity decay was characterized by a curvilinear decay of velocity, which followed that of a wall jet on a smooth, rigid bed for streamwise distance approximately equal to 2L. For the surface-jet flow regime, the decay of velocity was observed to be similar to that of a free-jump on a smooth, rigid bed for a streamwise distance approximately equal to L. Here, L is defined as the streamwise distance measured from the end of the rigid apron to where the maximum streamwise velocity in the jet is half the velocity of the jet at the end of apron. The streamwise maximum velocity of the jet was then seen to increase in what was called the recovery zone.A relationship for the streamwise decay of the maximum velocity within the scour hole is proposed. Moreover, other scales representing the flow inside the scour hole such as the streamwise distance from the end of the apron to where the streamwise maximum velocity starts to deviate from curvilinear to linear decay and the streamwise distance to where maximum streamwise velocity starts to increase are suggested. Some new results on the velocity distribution for the reverse flow for a “bed-jet” flow regime are also presented. Finally, some dimensionless empirical equations describing the relationship between the jet scales for the jet flow in a scour hole and the scour hole size are given

    Economic Dynamics of Tourism in Nepal: A VECM Approach

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    Tourism has been growing in Nepal. Tourism creates various direct, indirect and induced effects in the economy. This paper is designed to examine the role of tourism development on economic growth in Nepal. The study is based on annual data of gross domestic product, foreign exchange earnings from tourism and real effective exchange rate for the period spanning from 1975 to 2013. It examines the causality and long-run relationships between economic growth and Tourism development in Nepal using co-integration techniques and a Vector Error Correction Model (VECM). The evidence confirms that tourism development causes economic growth in short run in Nepal. The result also indicates the causality runs from both sides i.e. tourism development to economic growth and economic expansion to tourism growth implying for the greater efforts to encourage both the activities in the economy

    FINANCING PRACTICES OF BANKS AND FINANCIAL INSTITUTIONS IN NEPAL

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    Proposal analysis and credit appraisal includes the examination of business and financial aspects with respective importance to measure economic, financial and technical feasibility of the project and repayment capacity of the borrowing firm. Such analysis has far reaching implication on the mobilization of resources as well as on the earning and soundness of the banks and financial institutions (BFIs). We examine this process in the context of bank lending to tourism business enterprises through a survey. The result incorporates the importance accorded by BFIs on business and financial aspects of the proposal. Using Phi-Coefficient ( ) the study finds a strong relationship between various aspects examined during the proposal analysis and credit appraisal. Further, we also examine the cross significance of business and financial aspects and find a significant relationship between business prospects with most of the financial aspects. The findings are relevant for both bankers and beneficiaries to ensure the suitability of tourism sector loan processing and significance of credit appraisal

    Economic Dynamics of Tourism in Nepal: A VECM Approach

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    Tourism has been growing in Nepal. Tourism creates various direct, indirect and induced effects in the economy. This paper is designed to examine the role of tourism development on economic growth in Nepal. The study is based on annual data of gross domestic product, foreign exchange earnings from tourism and real effective exchange rate for the period spanning from 1975 to 2013. It examines the causality and long-run relationships between economic growth and Tourism development in Nepal using co-integration techniques and a Vector Error Correction Model (VECM). The evidence confirms that tourism development causes economic growth in short run in Nepal. The result also indicates the causality runs from both sides i.e. tourism development to economic growth and economic expansion to tourism growth implying for the greater efforts to encourage both the activities in the economy
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