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41.
42.
An innovative conductometric measurement technique using a nonconventional but high‐performance (high‐precision, high‐resolution, rapid response features for online graphic display) in house–built pulsating conductivity monitoring instrument has been deployed to study the kinetic behavior during the reaction of ethyl acetate and NaOH. A laboratory‐made constant temperature reaction bath with the facility of continuous stirring of solution for homogeneous mixing was used to carry out experiments at desired solution temperatures. Rate constants of the saponification reaction in the temperature range at various temperatures (30–55°C) were determined, and the results were compared with the reported values. Although the reported data exhibit wide scatter, our data are in agreement with some of the literature data. From these data, thermodynamic parameters such as activation energy, activation enthalpy, activation entropy, and activation free energy have been evaluated. With the introduction of this novel conductometric measurement technique, the determination of rate constants at various solution temperatures becomes much simpler and faster. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 648–656, 2011 相似文献
43.
Ch.?Binek P.?Borisov Xi?Chen A.?Hochstrat S.?Sahoo W.?KleemannEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,45(2):197-201
Perpendicular exchange bias (PEB) involving perpendicular
magnetic anisotropy (PMA) in both the antiferromagnetic (AF) pinning and the
ferromagnetic (FM) sensor layer is expected to become important in future
perpendicular recording and sensing devices. Further, because of the reduced
spin dimensionality, PEB promises to be easier understandable than the
conventional planar exchange bias (EB). In addition to its first realization
using the Ising-type AF compounds FeF2 and FeCl2 we have tested
control strategies of EB being alternative to the conventional magnetic and
thermal ones. Indeed, specific symmetry properties of the pinning layer have
been shown to enable mechanical (viz. piezomagnetic via FeF2) and electric
control (viz. magneto-electric via Cr2O3) of EB, respectively.
Electric control promises to become relevant for TMR devices in MRAM
technology. 相似文献
44.
C.?SurEmail author B. K.?Sahoo R. K.?Chaudhuri B. P.?Das D.?Mukherjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,32(1):25-31
We have employed the relativistic coupled cluster theory to calculate
the magnetic dipole and electric quadrupole hyperfine constants for
the ground and low lying excited states of singly ionized magnesium.
Comparison with experimental and the other theoretical results are
done and predictions are also made for a few low lying excited states
which could be of interest. We have made comparative studies of the
important many body effects contributing to the hyperfine constants
for the different states of the ion. 相似文献
45.
Poly(butyl acrylate) (PBA)/sodium silicate (SS) nanocomposites were prepared via emulsifier-free emulsion technique in presence of Cu(II)/glycine chelate complex and ammonium persulfate (APS) initiator. The strongly hydrophobic PBA was intercalated into the hydrophilic SS layer. Since the interlayers of silicate were filled with sodium cations, the hydrophilic properties were enhanced and lead to high degree of swelling. The formation of the PBA/SS nanocomposite was confirmed by infrared spectra (IR). Furthermore, as evidenced by transmission electron microscopy (TEM), the composite so obtained was found to have nanoscale structure. X-ray diffraction (XRD) was used to characterize the nanoscale dispersion of the layer silicate and useful for measurement of d-spacing in interlayer system. It was found from thermogravimetric analysis that PBA/SS nanocomposites had more thermal stability as compared to raw PBA due to intercalation. Burning test of the nanocomposites performance exhibited a flame retardant property, which was also verified from cone calorimeter analysis. For its commercialization, the ecological friendly nature was studied via biodegradation and was found to have better biodegradability than the raw PBA. 相似文献
46.
B. K. Rana R. M. Tripathi S. K. Sahoo N. K. Sethy V. S. Sribastav A. K. Shukla V. D. Puranik 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(3):711-717
A brief study on dissolved radionuclides in aquatic environment, especially in ground water, constitutes the key aspect for assessment and control of natural exposure. In the present study the distribution of natural uranium and 226Ra concentration were measured in ground water samples collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007–2008. The natural uranium content in the ground water samples in this region was found to vary from 0.1 to 3.75 μg L?1 with an average of 0.87 ± 0.73 μg L?1 and 226Ra concentration was found to vary from 5.2 to 38.1 mBq L?1 with an average of 13.73 ± 7.34 mBq L?1. The mean annual ingestion dose due to intake of natural uranium and 226Ra through drinking water pathway to male and female adults population was estimated to be 6.55 and 4.78 μSv y?1, respectively, which constitutes merely a small fraction of the reference dose level of 100 μSv y?1 as recommended by WHO. 相似文献
47.
Spatially homogeneous Bianchi types V and VI0 cosmological models are studied with source cosmic cloud strings coupled with electromagnetic field in Rosen’s (Gen. Relativ.
Gravit. 4:435, 1973) bimetric theory of relativity. It is observed that Bianchi type V space time is feasible whereas Bianchi type VI0 is not feasible. In the feasible case different equations of state for cosmic strings with Maxwell fields do not survive
in this theory and the space-time turns out to be flat. 相似文献
48.
Santanu Pyne Priyanka Sarkar Samita Basu Gobinda Prasad Sahoo Dipak Kumar Bhui Harekrishna Bar Ajay Misra 《Journal of nanoparticle research》2011,13(4):1759-1767
Synthesis of core @ shell (Au @ Ag) nanoparticle with varying silver composition has been carried out in aqueous poly vinyl
alcohol (PVA) matrix. Core gold nanoparticle (~15 nm) has been synthesized through seed-mediated growth process. Synthesis
of silver shell with increasing thickness (~1–5 nm) has been done by reducing Ag+ over the gold sol in the presence of mild reducing ascorbic acid. Characterization of Au @ Ag nanoparticles has been done
by UV–Vis, High resolution transmission electron microscope (HRTEM) and energy dispersive X-ray (EDX) spectroscopic study.
The blue shift of surface plasmon resonance (SPR) band with increasing mole fraction of silver has been interpreted due to
dampening of core, i.e. Au SPR by Ag. The dependence of nonlinear optical response of spherical core @ shell nanoparticles
has been investigated as a function of relative composition of each metal. Simulation of SPR extinction spectra based on quasi-static
theory is done. A comparison of our experimental and the simulated extinction spectra using quasi-static theory of nanoshell
suggests that our synthesized bimetallic particles have core @ shell structure rather than bimetallic alloy particles. 相似文献
49.
Dibakar Sahoo Prosenjit Bhattacharya Hirak Kumar Patra Paulami Mandal Sankar Chakravorti 《Journal of nanoparticle research》2011,13(12):6755-6760
Change of α-helical structure of heme protein (Hb) to a β-sheet and random coil conformation because of the interaction of
glycine capped gold nanoparticles (20–60 nm) as observed from attenuation total reflectance, absorption, Fourier transform
infra red, and Circular Dichroism spectroscopy has been reported in this article. Upon interaction, protein takes a cylindrical
shape of length 12 μm and diameter 0.35 μm as revealed from scanning electron microscopy and transmission electron microscopy.
The Selected-Area Electron beam Diffraction pattern shows change of crystalline structure in GNP to amorphous nature with
the interaction of Hb. 相似文献
50.