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81.
N. Vijayan N. Rani G. Madhurambal G. Bhagavannarayana B. Rathi R. Philip K. Safakath S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2013,112(2):1113-1119
The title compound of iminodiacetic acid hydrochloride (IDAAMHCL) has been successfully synthesized by adopting conventional chemical reaction and the single crystals have been grown by solvent evaporation method at room temperature and studied its various properties and reported for the first time. The lattice dimension and the crystal structure were identified from the powder X-ray diffraction analysis. The crystalline perfection assessed by high resolution X-ray diffraction technique shows that the specimen is free from structural grain boundaries. The presence of functional groups and the protons in IDAAMHCl was confirmed by Fourier transform infra-red and NMR (1H and 13C) spectroscopic techniques. The presence of carbon, hydrogen, and nitrogen was confirmed by elemental analysis. The optical behavior of IDAAMHCl was assessed by UV-visible spectroscopy and it is found that there is no absorption in the entire visible region of the spectrum. The Z scan measurements at 532 nm with 5 ns laser pulses show that IDAAMHCL is a very good candidate for optical limiting applications. 相似文献
82.
Lakshmi Vijayan 《Journal of Physics and Chemistry of Solids》2011,72(6):613-619
Nano-crystallites of Li1.3Ti1.7Al0.3(PO4)2.9(VO4)0.1 NASICON type material are prepared by means of solid-state reaction of a stoichiometric mixture after milling it for 22 and 55 h. The milling reduces the average crystallite size of the ceramic to 80 and 60 nm, respectively. Mechanical milling changes structural parameters and the strain induced at the grain-boundaries plays a major role in improving electrical conductivity. An order of magnitude increase in electrical conductivity is observed in the material milled for 55 h compared to the unmilled material, which is also reflected in permittivity loss. Modulus and permittivity representations substantiate the constriction effect of grain-boundaries observed in the complex impedance representation. 相似文献
83.
Mohammed Nazrul Islam K. Vijayan Asari Mohammad S. Alam 《Optics Communications》2011,284(6):1532-1539
This paper proposes a novel pattern recognition system for invariance to noise and distortions. The technique first generates a synthetic discriminant function of the target image from its different distorted versions. It then takes four different phase-shifted versions of the reference image, which are individually joint transform correlated with the given input scene. Thus the proposed algorithm produces a single cross-correlation signal corresponding to each potential target. Also a fringe-adjusted filter is designed to generate a delta-like correlation peak with high discrimination between the signal and the noise. The pattern recognition system is also designed for the identification of multiple targets belonging to multiple reference objects simultaneously in a given input scene. The proposed technique is investigated using computer simulation including real-life images in different complex environments. 相似文献
84.
Kalyani D McMurtrey KB Neufeldt SR Sanford MS 《Journal of the American Chemical Society》2011,133(46):18566-18569
This communication describes the development of a room-temperature ligand-directed C-H arylation reaction using aryldiazonium salts. This was achieved by the successful merger of palladium-catalyzed C-H functionalization and visible-light photoredox catalysis. The new method is general for a variety of directing groups and tolerates many common functional groups. 相似文献
85.
A Simple and Highly Sensitive Electrochemically Reduced p‐Nitrobenzoic Acid Film Modified Sensor for Determination of Mercury
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Herein, a simple electrochemical sensor was fabricated for sensing Hg2+ ions by using electrochemically reduced p‐nitrobenzoic acid molecules modified (ERpNBA) glassy carbon electrode (GCE). The modified electrode was applied for the determination of Hg2+ ions by using differential pulse anodic stripping voltammetry (DPASV). Experimental parameters such as concentration of p‐nitrobenzoic acid used for electrode modification, pH, accumulation time and deposition potential used for the determination of Hg2+ ions were optimized. The strong interaction between the Hg2+ ions and the lone pair of electrons on the nitrogen atoms of ERpNBA molecules leads to highly selective adsorption of Hg2+ ions on the modified electrode. Under the optimum experimental conditions, the sensor showed higher sensitivity and very low detection limit for Hg2+ ions than other metal ions such as Cd2+, Pb2+ and Zn2+ ions. The LOD for Hg2+ ions was 240 pM which is below the guideline value given by the World Health Organization and the earlier reports. 相似文献
86.
Multistate transition models are increasingly used in credit risk applications as they allow us to quantify the evolution of the process among different states. If the process is Markov, analysis and prediction are substantially simpler, so analysts would like to use these models if they are applicable. In this paper, we develop a procedure for assessing the Markov hypothesis and discuss different ways of implementing the test procedure. One issue when sample size is large is that the statistical test procedures will detect even small deviations from the Markov model when these differences are not of practical interest. To address this problem, we propose an approach to formulate and test the null hypothesis of “weak non‐Markov.” The situation where the transition probabilities are heterogeneous is also examined, and approaches to accommodate this case are indicated. Simulation studies are used extensively to study the properties of the procedures, and two applications are to illustrate the results. 相似文献
87.
Vijayan T. Roychowdhury P. Iyyengar S.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1994,22(2):199-204
An intense beam is not propagated in vacuum because of its space charge. In this work, an intense electron beam of 250 keV, 6 kA, 80 ns is propagated after initial collimation inside a short length of dielectric tube and further confinement provided by ions attributed to beam irradiation. Such beams have important potential in particle beam and controlled fusion research. It is seen that electrons are slowed down to the ion velocity, while ions are collectively accelerated by the beam space-charge. Collimator geometry is varied for space-charge control. Elongation of the beam pulse width to 100-300 ns is observed depending on propagation distance. Explanations are presented through physical model and scaling laws 相似文献
88.
M. Ashok T. R. Rautray Pranaba K. Nayak V. Vijayan V. Jayanthi S. Narayana Kalkura 《Journal of Radioanalytical and Nuclear Chemistry》2003,257(2):333-335
The elemental analysis of south Indian gallstones has been carried out using energy dispersive X-ray fluorescence (EDXRF) spectroscopy. A number of important elements including Fe, Cu, Zn, Br, and Pb were estimated from the EDXRF spectra. The results are presented and discussed. 相似文献
89.
Kalyani Desikan 《Pramana》1995,45(6):511-517
BD-FRW universe filled with imperfect fluid having bulk viscosity is investigated under the framework of Israel-Stewart-Hiscock
causal theory. The field equations have been solved by using the relationφ=KR
α
whereK andα are constants, between the Brans-Dicke scalar fieldϕ and the scale factorR. This relation, in fact, leads to a constant deceleration parameterq. It is shown that the constancy of the deceleration parameter permits only two possibilities i.e. eitherH=constant withm=1 orm=(1+b −α)/(2(1+b) −α), irrespective of the value ofɛ. 相似文献
90.