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141.
Kalla Reddi Mohan Naidu Shaik Ibrahim Khalivulla Syed Rasheed Sharida Fakurazi Palanisamy Arulselvan Ola Lasekan Faridah Abas 《International journal of molecular sciences》2013,14(1):1843-1853
Polymer supported dichlorophosphate (PEG-OPOCl2) is an efficient green catalyst for the electrophilic substitution reaction of indole with aromatic aldehydes, in neat condition, to afford an excellent yield of bis(indolyl) methanes with short reaction time, at room temperature. The synthesized compounds and their anti-cancer activity are evaluated. 相似文献
142.
S. Sarkar P. Mohan Raj S. Chakraborty G. Phanikumar K. Chattopadhyay P. Dutta 《Journal of Materials Science》2003,38(1):155-164
A three dimensional, transient model is developed for studying heat transfer, fluid flow and mass transfer for the case of a single-pass laser surface alloying process. The numerical study is performed in a co-ordinate system fixed to the laser which moves with a constant scanning speed. The coupled momentum, energy and species conservation equations are solved using a finite volume technique. Phase change processes are modelled using a fixed-grid enthalpy-porosity technique, which is capable of predicting the continuously evolving solid-liquid interface. The three-dimensional model is able to predict the species concentration distribution inside the molten pool during alloying, as well as in the entire cross section of the solidified alloy. Corresponding experimental results show a good qualitative agreement with the numerical predictions with regard to pool shape and final composition distribution. 相似文献
143.
R. Rathes Kannan A. Mohan P. Issac Nelson V. Arivazhagan B. Vidhya S. Rajesh 《Journal of Materials Science: Materials in Electronics》2018,29(9):7041-7047
The article investigates the structural and optical properties of ZnPc/PbSe hybrid multilayer (HML) structure deposited by using thermal evaporation technique. The X-ray diffraction pattern reveals the formation of ZnPc–PbSe composite and strain induced quantum size effect. Scanning electron microscope image shows the spherical grains for as-deposited film and nanorod like structure for the annealed film. The rods are oriented along one direction and stacking axis changes with the function of annealing temperature. The optical spectra show strong absorption in UV–Visible region and the optical absorption edge was red shifted for annealed samples. The luminescence properties were enhanced with broad emission in the range of 375–400 nm in HMLs. The optical band gap values are calculated and it varies from 3.2 to 3.04 eV with the function of annealing temperature and the band gap splitting was observed for a higher temperature of annealed samples. Strain-induced effect on ZnPc/PbSe HML has been reported using Raman spectra. 相似文献
144.
145.
Dynamic model incorporating damping characteristics, namely joint damping and structural damping in flexible links, of the serial robots with rigid and flexible links is presented. A novel procedure, based on the unified approach of theoretical formulation and analysis of experimental data, is proposed for the estimation of damping coefficients. First, the dynamic model of a robotic system with rigid and flexible links is presented. Next, the modifications in the dynamic model due to the considerations of damping characteristics of joints and structural damping characteristics of the flexible links are presented. A systematic methodology based on analysis of data obtained from experiments is presented for estimation and determination of damping coefficients of rigid-flexible links. The determination of joint damping coefficients, is based on the logarithmic decay of the amplitude of the oscillations of robotic links, while the structural damping coefficients are estimated mainly using the modal analysis and the method of evolving spectra. The method of evolving spectra, based on the Fast Fourier Transform of the decay of the amplitude in structural vibrations of the robot links in progressive windows is used to estimate the structural damping ratios while the critical structural coefficients are determined using the modal analysis. The methodology is illustrated through a series of simple experiments on simple robotic systems. The experimental results are then compared with the simulation results incorporating the damping coefficients determined using the proposed procedure. The comparisons leads to the validation of the proposed dynamic modeling technique, modeling of the damping characteristics, and the method proposed for estimation of damping coefficients for rigid-flexible link robotic systems. 相似文献
146.
S.A.Saleem B.C.Jamalaiah A.Mohan Babu K.Pavani L.Rama Moorthy 《中国稀土学报(英文版)》2010,28(2):189-193
Glasses with chemical composition of (in mol.%): 26 RF-20 PbO-10 TeO2-43 H3BO3-1 EuO3 (RLTB) were prepared by conventional melt quenching method. The Judd-Ofelt intensity parameters Ω2 and Ω6 were obtained from the absorption intensities of 7F0→5D2 and 7F0→5L6 transitions, respectively. In order to overcome the problem of applicability of Judd-Ofelt analysis at room temperature due to the overlapping of the transitions originating from 7F0 and 7F1 levels of Eu3+ ion, the effect of the thermalization on the population of energy levels was taken into account. The photoluminescence spectra contained five emission bands originating from the 5D0 metastable state to 7FJ (J=0, 1, 2, 3, 4) lower lying states. The decay profiles were found to be single exponential in all the three glasses. The measured lifetimes (τmes) were in good agreement with the calculated lifetimes (τcal) obtained by using the thermally corrected Judd-Ofelt intensity parameters. 相似文献
147.
Parameter Estimation in Water Distribution Networks 总被引:2,自引:2,他引:0
Shanmugam Mohan Kumar Shankar Narasimhan S. Murty Bhallamudi 《Water Resources Management》2010,24(6):1251-1272
Estimation of pipe roughness coefficients is an important task to be carried out before any water distribution network model is used for online applications such as monitoring and control. In this study, a combined state and parameter estimation model for water distribution networks is presented. Typically, estimation of roughness coefficient for each individual pipe is not possible due to non-availability of sufficient number of measurements. In order to address this problem, a formal procedure based on K-means clustering algorithm is proposed for grouping the pipes which are likely to have the same roughness characteristics. Also, graph-theoretic concepts are used to reduce the dimensionality of the problem and thereby achieve significant computational efficiency. The performance of the proposed model is demonstrated on a realistic urban water distribution network. 相似文献
148.
Nalluri Mohan Rao 《Sadhana》2010,35(6):739-746
The range of motion of the moving platform of a spatial 3-RPS parallel manipulator will be greatly influenced by the physical constraints such as limits on the lengths of the limbs and the range of motion of the spherical joints. Therefore, while synthesizing the parallel manipulator, the physical constraints have to be considered. Synthesis of the manipulator involves determination of the architectural parameters of the manipulator so that a point on the moving platform passes through a prescribed set of positions in space. This paper presents a synthesis procedure that determines location and direction of revolute joints and location of spherical joints along with orientation of sockets of spherical joints, considering the physical constraints. The synthesis procedure is demonstrated through a numerical example. 相似文献
149.
Swati Mohan Rajiv Prakash 《Materials science & engineering. C, Materials for biological applications》2010,30(5):781-787
We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized π electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and –OH group is confirmed using UV–vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and π-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration. 相似文献
150.
Brown rice malt from Indica and Japonica type rice were prepared and their nutrient composition as well as non-starch polysaccharide (NSP) contents and also some of the physico-chemical characteristics were determined. The activity of α- and β-amylases in the ungerminated (native) rice was negligible but increased considerably on germination. Malting altered the chemical composition of both Indica and Japonica rice to a small extent but caused noticeable changes in the pasting characteristics. The free sugars and water-soluble non-starch polysaccharide (NSP) contents of the malt samples were considerably higher than the native samples. The carbohydrate elution profile of native and malted rice on Sepharose CL-2B revealed partial degradation of starch. However, the electrophoresis patterns of the native and malt samples were comparable but exhibited decrease in their band intensity. The study revealed that, controlled germination or malting causes considerable changes in the physico-chemical and bio-chemical properties of both Indica and Japonica rice. 相似文献