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141.
Arup Kumar Pathak Manoj Tripathy Amrita Das Alok Kumar Samanta 《Molecular physics》2013,111(8):975-982
This is the first time a microscopic theory-based bottom-up approach has been implemented to derive an analytical expression for the solvation energy for a finite (N) system, including the bulk. This bottom-up approach provides the information on solvation energies of anionic solutes in finite-size clusters, including the bulk (N = ∞), from the knowledge of the detachment energies for the system containing a few numbers of solvent molecules. However, in the case of dielectric constant, a microscopic theory-based top-down approach has been prescribed to derive an analytical expression for the static dielectric constant for the finite system. In this approach, the knowledge of the dielectric constant for the bulk provides a scheme to obtain the same quantity for a wide numbers of solvent molecules. As an illustrative example, the hydrated doubly charged anions, SO?2 4.NH2O and C2O?2 4.NH2O, have been considered, and the calculated bulk solvation energy for the SO?2 4.NH2O system is found to be in very good agreement (within 5%) with the available experimental result. However, the same quantity calculated based on the Born model is found to be largely deviating (32%) from the experimental result. The calculated results of the dielectric constant for these two systems support the linear theory of dielectric constant. 相似文献
142.
C. Sunil A.A. Shanbhag M. Nandy S.P. Tripathy G.S. Sahoo D.S. Joshi R.M. Kale P.K. Sarkar D.N. Sharma 《Radiation measurements》2012,47(10):1035-1043
The neutron ambient dose equivalent has been measured from 10B, 11B, 12C, 13C, 16O and 18O projectiles of energy 5 MeV/amu incident on a thick Al target at 0°, 30°, 60° and 90° with respect to the beam direction using a conventional dose equivalent meter. The calculated results obtained using previously reported empirical relations do not reproduce the experimental data. The results obtained from the PACE nuclear reaction code are closer to the experimental data as compared to the various empirical expressions. The ratio of the increase in the dose rates when the projectile is changed from the lighter to the heavier isotopes is fairly reproduced by most of the empirical formulations and the PACE code. A previously reported relation for the slope parameter is used to predict the directional distribution of the neutron dose for the projectiles used in this study. The calculated doses are lower than the experimental results in the forward directions but agree within the uncertainties at the backward directions. A new set of projectile-based parameters have been derived from the present experimental data which can be used in an empirical formulation. 相似文献
143.
The present work looks into the aspect of thermal modifications induced in polymers by proton irradiation. The kinetics of thermal decomposition of polymers is investigated by using the thermogravimetric (TG) technique. It has been observed that the degradation of polymers is a multi-step process that involves sequential and competing processes, and obeys the Arrhenius kinetics which allows us to connect the rate constant with the absolute temperature and the activation energy. The activation energy of thermal decomposition has been calculated from the TG curves, and its variation with different irradiation doses has been derived. 相似文献
144.
In this paper we have investigated the spectrum of the Cesàro operator C 1 which is regarded as an operator on the sequence space $b\bar v_0 \cap \ell _\infty $ the space of statistically null bounded variation sequences. 相似文献
145.
Well-designed, monodispersed porous ZnO hollow microspheres with controlled hole-opening were successfully synthesized by a facile two-step solution route at low temperature. The hollow microspheres having average diameter of 3-4 μm showed time-dependent hole-opening, i.e. 4-100% for 15-75 min. The hole-opening percentage increases linearly with time until complete opening. The ZnO hollow microspheres also exhibited a high surface area (34 m(2) g(-1)), a large pore volume (0.19 cm(3) g(-1)) and an average pore diameter of 3.8 nm. A plausible growth mechanism for the formation of ZnO hollow microspheres was also proposed. 相似文献
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148.
We propose a sensitive pressure and temperature sensor depends on hollow core rectangular photonic crystal fiber. The proposed modeling is carried out by implementing 2-D finite difference time domain (FDTD) method. The two parameters like pressure and temperature plays a vital role in reservoir engineering to increase the production rates of oil well and our sensor technique is depend on the transmission peak wavelength shift which is caused by temperature/pressure change, and geometrical parameter of the structure of rectangular PCF. Here we have done simulation for various work using 2-D FDTD method application to sensing. We have shown the proposed design which provides the sensitivity with linear dependence of the resonance wavelength over refractive index of PCF holes at a operating wavelength of 1.55 μm. 相似文献
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150.
Umakanta Tripathy Maxime Giguère-Bisson Mohammad Hussain Sangji Marie-Josée Bellemare D. Scott Bohle Elias Georges Paul W. Wiseman 《Analytical and bioanalytical chemistry》2013,405(16):5431-5440
The pigment hemozoin is a natural by-product of the metabolism of hemoglobin by the parasites which cause malaria. Previously, hemozoin was demonstrated to have a very high nonlinear optical response enabling third harmonic generation (THG) imaging. In this study, we present a complete characterization of the nonlinear THG response of natural hemozoin in malaria-infected red blood cells, as well as in pure isostructural synthesized hematin anhydride, in order to determine optimal imaging parameters for detection. Our study demonstrates the wavelength range for optimal pulsed femtosecond laser excitation of THG from hemozoin crystals. In addition, we show the hemozoin crystal detection as a function of crystal size, incident laser power, and the emission response of the hemozoin crystals to different incident laser polarization states. Our systematic measurements of the nonlinear optical response from hemozoin establish detection limits, which are essential for the optimal design of malaria detection technologies that exploit the THG response of hemozoin. Figure
Combined overlay image of THG (bright crystals in blue, one scan per frame) and TP autofluorescence (oval cells in red, average of 15 sequential frame scans) of natural hemozoin crystals and red blood cells (infected with FCR-3 Plasmodium falciparum), respectively, collected at the laser excitation wavelength of 1170 nm with 100 mW average incident power and pixel dwell time of 5 μs 相似文献