Assessment of hydrologic impacts of climate change in Tunga-Bhadra river basin, India with HEC-HMS and SDSM

Climate change would significantly affect many hydrologic systems, which in turn would affect the water availability, runoff, and the flow in rivers. This study evaluates the impacts of possible future climate change scenarios on the hydrology of the catchment area of the TungaBhadra River, upstream of the Tungabhadra dam. The Hydrologic Engineering Center's Hydrologic Modeling System version 3.4 (HEC-HMS 3.4) is used for the hydrological modelling of the study area. Linear-regression-based Statistical DownScaling Model version 4.2 (SDSM 4.2) is used to downscale the daily maximum and minimum temperature, and daily precipitation in the four sub-basins of the study area. The large-scale climate variables for the A2 and B2 scenarios obtained from the Hadley Centre Coupled Model version 3 are used. After model calibration and testing of the downscaling procedure, the hydrological model is run for the three future periods: 20112040, 20412070, and 20712099. The impacts of climate change on the basin hydrology are assessed by comparing the present and future streamflow and the evapotranspiration estimates. Results of the water balance study suggest increasing precipitation and runoff and decreasing actual evapotranspiration losses over the sub-basins in the study area.

M-HMS的合成、表征及在苯酚羟化反应中的催化性能

以同晶取代方法合成了 M-HMS(M=Fe、Cu、Co、V,HMS:Hexagonal Mesoporous Silicates)中孔分子筛 .经 XRD、IR、ESP表征 ,证明过渡金属离子已进入 HMS骨架中 .在苯酚羟化反应中考察了 M-HMS的催化性能 .结果表明 ,M-HMS的催化性能明显高于相对应的 M/Si O2 负载型催化剂 .依据引入 HMS骨架的过渡金属离子是苯酚羟化反应的活性中心 ,以及 H+ 和 OH- 可能参与反应的结果提出了可能的反应机理

硅钨杂多酸在中孔全硅分子筛HMS上的固载及其催化性能

用十二烷基胺代替传统的季铵盐合成了中孔全硅分子筛ＨＭＳ，并将硅钨杂多酸（ＳｉＷ１２）浸渍固载在ＨＭＳ上．用ＸＲＤ，ＦＴ－ＩＲ以及ＮＨ３－ＴＰＤ等手段对ＨＭＳ及不同负载量和焙烧温度的负载催化剂进行了表征．即使在固载量为５０％的ＳｉＷ１２／ＨＭＳ中，ＳｉＷ１２仍保持其Ｋｅｇｇｉｎ结构并均匀分布在载体表面上，没有ＳｉＷ１２晶相生成．同时，在气－固相反应体系中研究了固载在ＨＭＳ上的ＳｉＷ１２在合成乙酸丁酯中的催化性能．实验结果表明，２００℃焙烧可以增强杂多酸与ＨＭＳ内表面之间的相互作用，从而使其对酯化反应活性具有一定的影响，并且固载催化剂在较低反应温度下具有较高的酯化活性，且性能稳定，有一定的应用前景.

Immobilization of the heteropoly acid (HPA) H4SiW12O40 (SiW12) on mesoporous molecular sieves (HMS and MCM-41) and their catalytic behavior

Supported catalysts, consisting of SiW12 immobilized on hexagonal mesoporous silica (HMS) and its aluminum-substituted derivative (MCM-41) with different loadings and calcination temperatures, have been prepared and characterized by X-ray diffraction, FT-IR and NH3-temperature programmed desorption. It is shown that SiW12 retains the Keggin structure on the mesoporous molecular sieves and no HPA crystal phase is developed, even at SiW12 loadings as high as 50 wt%. In the esterification of acetic acid by n-butanol, supported catalysts exhibit a higher catalytic activity and stability and held some promise of practical application. In addition, experimental results indicate that the loaded amount of SiW12 and the calcination temperatures have a significant influence on the catalytic activity, and the existence of aluminum has also an effect on the properties of supported catalysts.

[Le] destroyer [HMS Wivern D66] dans le port de Londonderry : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59877