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91.
Amit Kumar Dubey Praveen Gupta Subashisa Dutta Bimlesh Kumar 《International journal of remote sensing》2013,34(23):7815-7827
In this study, river stage variation derived from satellite altimetry was used to assess the water level, monthly discharge, and annual water yield at six virtual gauging stations at the braided reaches of the Brahmaputra River. The braided reaches of the river dynamically change their planform, thalweg line, and aggradation or degradation period. Stage records derived from the Envisat satellite of the European Space Agency and Topex/Poseidon of NASA/CNES were used for the period 2002–2010. Spatial interpolation and datum correction were applied on altimetry-derived river stage records before analysis. A correlation and error analysis between the in situ and satellite-altimetry-derived stages was carried out for these stations for both monsoon and non-monsoon seasons. Yearly optical satellite images were used for qualitative assessment of temporal variations in aggradation/degradation phases at the gauging stations. Using the pseudo-rating curve, discharges at two virtual gauging stations were estimated. The results show that the altimetry-estimated discharges are of good agreement with observed discharge for the monsoon months (June–September) as compared with the non-monsoon months (October–May). In order to assess the annual water yield variability, yearly variation in annual water yield from the altimetry data was also estimated and compared to that observed. The estimated annual water yields were 90% accurate. Similarly, the long-term averaged monthly discharge series estimated from satellite altimetry closely follows the temporal trend of that of the observed series. 相似文献
92.
The structure, morphology, and properties of an ionomer, poly(ethylene‐acrylic‐acid) neutralized by zinc salts (PI) depend on the free carboxylic acid content. In this work, metal acetates (Na, Zn, and Al acetates) were used to control the neutralization levels. A wide range of techniques were used, such as spectroscopic Fourier transform infrared spectroscopy (FTIR), thermal [thermogravimetric analysis, modulated differential scanning calorimetry (MDSC), and dynamic mechanical analysis (DMA)], mechanical (tensile measurement), and small angle neutron scattering (SANS). The melt rheological properties of the samples were also examined. The results show that metal acetate neutralizes free acrylic acid in the ionomer, which has the primary role in controlling ionic association. The number of ionic groups in ionic domains and multiplets in the matrix is dependent on the neutralization level. Metal valence determines the ionic domain or multiplet structure (FTIR), further properties of PI. Dynamic mechanical properties, the ionic transition behaviour, and the mechanical properties are improved compared with PI using monovalent cation (Na+), but decreased using trivalent cation (Al3+) or shows less significant changes due to steric effects. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
93.
Cd1 ? x Pb x S thin films were prepared by spray pyrolysis technique onto glass substrate at 300°C temperatures. The prepared films were characterized elemental, structural and optical properties by energy dispersive X-ray, scanning electron microscopy, X-ray diffraction and UV-VIS spectrophotometer. Energy dispersive X-ray confirmed the presence of Cd, S and Pb in the films. SEM images show that the deposition covered the substrate well uniformly and incorporation of Pb. Crystal structure was found hexagonal and the estimated grain size was lies in between 9 to 49 nm. The optical band gap was decreased from 2.43 to 2.07 eV. 相似文献
94.
This paper presents the development of a reliable heat index (HI) measurement system for evaluating the thermal comfort of a particular building or a particular area. The HI is an index that combines air temperature and relative humidity (RH) to determine the human-perceived equivalent temperature. To measure the air temperature and RH, temperature to digital converter and RH to voltage converter is used. HI is calculated online with the help of embedded firmware of the microcontroller. This calculated value is then transferred to the computer through standard RS 232 serial port. The same sensor node is tested with the RS 485 network standard by changing the transceiver of the node. The system is calibrated using four standard saturated binary salt solutions. 相似文献
95.
Saikat Maitra Farooq Ahmad Ananta K. Das Santanu Das Binay K. Dutta 《Bulletin of Materials Science》2010,33(2):185-190
In the present work the reaction between fly ash and lime in fly ash-lime compacts under water curing and steam curing conditions
was studied thoroughly in relation to the processing conditions. Fly ash from different sources were collected, characterized,
mixed with lime in different ratios and compacted. The compacts were cured with water and steam separately. The reduction
in the free CaO content in these compacts was measured as a function of curing time and curing process. Role of two ionic
additives, FeCl3 and MgCl2, on the reaction between fly ash and lime was also investigated by measuring the free CaO content. Kinetics of these reactions
was studied by determining the reaction order and rate constants with respect to the free CaO content and it was observed
that the curing conditions and additives affected the reaction kinetics significantly. 相似文献
96.
97.
98.
Mergers and acquisitions (M&A) are currently revolutionizing the structure of corporate U.S.A. and annually involve deals totalling billions of dollars. Consequently, it is an area of intense activity and interest within the financial community. The process of planning an M&A is enormously complex and involves sophisticated reasoning and planning, by several parties such as the raider, the target company, investment banks, etc. Computer based tools are often invaluable for planning several stages of an M&A, such as generating forecasted cash flows. Current computer aids for M&A however do not provide adequate support for many essential features such as real time planning, reasoning under uncertainty, nonmonotonic inference, case-based reasoning, etc. MARS is a prototype M&A reasoning tool developed at General Electric Corporate R&D that attempts to provide such features in an integrated environment. MARS both simulates and provides advice regarding the complex reasoning and planning involved in an M&A deal. In doing so, it provides an excellent test bed architecture for the testing, development and integration of several ideas from artificial intelligence. MARS is implemented in COMMON LISP using RUM [15] on top of KEE [18]. RUM, a development environment for reasoning under uncertainty is based on Bonissone's theory of plausible reasoning [2–4] and was also developed at General Electric Corporate R&D. 相似文献
99.
Effect of CuO additives on the reversibility of zirconia crystalline phase transitions 总被引:1,自引:0,他引:1
L. Lemaire S. M. Scholz P. Bowen J. Dutta H. Hofmeister H. Hofmann 《Journal of Materials Science》1999,34(9):2207-2215
We have studied the influence of the differents atmospheres on the sintering of CuO-doped-zirconia ceramics. After an annealing treatment in a reducing atmosphere, we have found nanoparticles of metallic copper in triple points and in the grains of the sintered zirconia. Furthermore, the influence of the intergranular Y2Cu2O5 phase on the tetragonal to monoclinic phase transition and the crystalline structure of zirconia is discussed with respect to results obtained from X-ray diffraction, differential thermal analysis, Raman spectroscopy and High Resolution Transmission Electron Microscopy. 相似文献
100.