27 research outputs found
Not Available
Not AvailableThe Double Ranked Set Sampling (DRSS) procedure has been extended to the case of estimation of finite population mean under classical approach of survey sampling. In view of the complexity of the theoretical framework, the sample sizes are restricted to ‘2’. Using real data, it is empirically demonstrated that an estimator based on DRSS procedure performs better than estimators based on the Ranked Set Sampling (RSS) procedure and Simple Random Sampling (SRS) respectively.Not Availabl
Azidation of Polyvinyl Nitrate and Energy Related Studies
Partially substituted polyvinyl azide (PVAZ) samples were prepared by reacting sodium azide with polyvinyl nitrate (PVN), containing 15.71 per cent N, in a solution of dimethyl formamide. Replacement of a large proportion of -ONO2 groups by - N3 groups in polymer chain ('azidation' of PVN) enhanced reactivity, impact sensitivity and energetics, but reduced thermal stability of the products. The thermogravimetric analysis of PVN showed the onset of rapid decomposition at about 171 °C. The kinetic analysis of thermogravimetric results indicated the validity of random nucleation first-order reaction model. A differential scanning calorimetry thermogram of PVAZ showed a peak at 183.9 °c and heat of decomposition of 2732 J/g, which is lower than that for PVN
An SCS-CN-based long-term daily flow simulation model for Be River catchment, Vietnam
Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732This paper presents a simple four-parameter Soil Conservation Conservation Service
Curve Number (SCS-CN)-based daily flow simulation model for the Be River catchment located in
Vietnam. The model is calibrated with a part of five years of total available data (1986-1990), and
tested on the remaining data. It is found to perform reasonably well in calibration and fairly well in
validation. An investigation revealed the watershed to have experienced a significant change to
favour greater runoff generation in 1990 than in other years; the infiltration and baseflow
mechanisms to be significantly dominating watershed processes compared to the surface flow
process; and the initial curve number CN0 and baseflow coefficient bf to be respectively the least and
most sensitive model parameters, and the remaining surface and ground water storage coefficients K
and Kb to be the least sensitive