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51.
This article deals with a semi‐analytical study on the electrophoresis of charged spherical rigid colloid by considering the effects of relaxation and ion size. The particle surface is taken to be either hydrophilic or hydrophobic in nature. In order to consider the ion size effect we have invoked the Carnahan and Starling model (J. Chem. Phys. 1969, 51, 635‐636). The mathematical model is based on Stokes equation for fluid flow, modified Boltzmann equation for spatial distribution of ionic species and Poisson equation for electric potential. We adopt a linear perturbation technique under a weak electric field assumption. An iterative numerical technique in employed to solve the coupled set of perturbed equations. We have validated the numerically obtained electrophoretic mobility with the corresponding analytical solution derived under low potential limit. Going beyond the widely employed Debye‐Hückel linearization, we have presented the results for a wide range of surface charge density, electrolyte concentration, and slip length to Debye length ratio. We have also identified several interesting features including occurrence of local maxima and minima in the mobility for critical choice of pertinent parameters. 相似文献
52.
BinodChandraTripathy SabitaMahanta 《应用数学学报(英文版)》2004,20(3):487-494
In this article we introduce the vector valued sequence space m(E_k,φ,∧),associated with themultiplier sequence ∧=(λ_k) of non-zero complex numbers,and the terms of the sequence are chosen from theseminormed spaces E_k,seminormed by f_k for all k∈N.This generalizes the sequence space m(φ) introducedand studied by Sargent.We study some of its properties like solidity,completeness,and obtain some inclusionresults.We also characterize the multiplier problem and obtain the corresponding spaces dual to m(E_k,φ,∧).We prove some general results too. 相似文献
53.
Bentz T Giri BR Hippler H Olzmann M Striebel F Szöri M 《The journal of physical chemistry. A》2007,111(19):3812-3818
The kinetics of the reaction of hydrogen atoms with propyne (pC3H4) was experimentally studied in a shock tube at temperatures ranging from 1200 to 1400 K and pressures between 1.3 and 4.0 bar with Ar as the bath gas. The hydrogen atoms (initial mole fraction 0.5-2.0 ppm) were produced by pyrolysis of C2H5I and monitored by atomic resonance absorption spectrometry under pseudo-first-order conditions with respect to propyne (initial mole fraction 5-20 ppm). From the hydrogen atom time profiles, overall rate coefficients k(ov) identical with -([pC3H4][H])(-1) x d[H]/dt for the reaction H + pC3H4 --> products ( not equal H) were deduced; the following temperature dependence was obtained: kov = 1.2 x 10(-10) exp(-2270 K/T) cm(3) s(-1) with an estimated uncertainty of +/-20%. A pressure dependence was not observed. The results are analyzed in terms of statistical rate theory with molecular and transition state data from quantum chemical calculations. Geometries were optimized using density functional theory at the B3LYP/6-31G(d) level, and single-point energies were computed at the QCISD(T)/cc-pVTZ level of theory. It is confirmed that the reaction proceeds via an addition-elimination mechanism to yield C2H2 + CH3 and via a parallel direct abstraction to give C3H3 + H2. Furthermore, it is shown that a hydrogen atom catalyzed isomerization channel to allene (aC3H4), H + pC3H4 --> aC3H4 + H, is also important. Kinetic parameters to describe the channel branching of these reactions are deduced. 相似文献
54.
Aparajita Duarah Amrit Goswami Tarun C. Bora Madhumita Talukdar Binod K. Gogoi 《Applied biochemistry and biotechnology》2013,170(8):1965-1973
An effort was made to isolate biocatalysts hydrolyzing epoxides from various ecological niches of northeast India, a biodiversity hot spot zone of the world and screened for epoxide hydrolase activity to convert different racemic epoxides to the corresponding 1, 2-vicinal diols. Screening of a total of 450 microorganisms isolated was carried out using NBP colorimetric assay. One of the strains TF1, after internal transcribed spacer sequence analysis, identified as Aspergillus tubingensis, showed promising enantioconvergent epoxide hydrolase activity. The hydrolysis of unsubstituted styrene oxide (1) occurred to give 97 % ee of R-(?)-1-phenylethane-1, 2-diol (6) with more than 99 % conversion within 45 min incubation. It is shown to be a cheap and practical biocatalyst for one step asymmetric synthesis of chiral R-diol. The other representative substrates (2–5), although underwent hydrolysis with more than 99 % conversion beyond 15 h, exhibited poor enantioselectivity. 相似文献
55.
In this article we introduce the difference sequence spaces W 0 [f,Δm ],W 1 [f,Δm ],W∞[f,Δm ] and S[f,Δm ],defined by a modulus function f.We obtain a relation between W 1 [f,Δm ] ∩l∞[f,Δm ] and S[f,Δm ] ∩l∞[f,Δm ] and prove some inclusion results. 相似文献
56.
In this article we introduce the paranormed sequence spaces(f,Λ,△m,p),c0(f,Λ,△m,p) and ■∞(f,Λ,△m,p),associated with the multiplier sequence Λ =(λk),defined by a modulus function f.We study their different properties like solidness,symmetricity,completeness etc.and prove some inclusion results. 相似文献
57.
Ganga Prasad Pandey Binod Kumar Kanaujia Surendra K. Gupta A. K. Gautam 《Wireless Personal Communications》2013,72(2):1157-1172
A new frequency agile BST varactor loaded stacked circular microstrip antenna is presented. The antenna is analysed using extended cavity model. One of two bands of antenna is tunable with the help of BST varactor. The upper band is useful for WiMAX and lower band for other wireless communication systems. Various antenna parameters like return loss, resonant frequency, frequency agility etc. have been investigated. The simulated results agree well with the numerical data. A frequency agility of 60.64 % is achieved, which is better than simple Varactor diode loaded antenna. Lowest resonant frequency of 0.866 GHz is obtainable that shows a significant physical area reduction. The group delay of S $_{11}$ remains constant for entire band of operation. 相似文献
58.
Ganga Prasad Pandey Binod Kumar Kanaujia A. K. Gautam Surendra K. Gupta 《Wireless Personal Communications》2013,70(1):139-151
An analysis and design of a novel ultra wideband L-strip proximity coupled slot loaded circular microstrip antenna is proposed. The theoretical model is developed using circuit theoretic approach and obtained results are validated by MoM based IE3D simulation software. Theoretical results show a good agreement with simulated results. The patch is designed on a thick substrate of thickness 11 mm for a design frequency of 3.74 GHz and provides ultra wide band operation. The parametric study is carried out for return loss, radiation pattern, antenna efficiency, radiation efficiency and gain. It is observed that the bandwidth of the antenna depends on slot parameter and L-strip feed dimensions. An ultra bandwidth of 2.82 GHz is achieved with consistent radiation characteristics. 相似文献
59.
In recent years, the use of sensors on mobile devices is highly desirable. In particular, an accelerometer can be used for numerous applications such as tracking object or monitoring of the elderly. This paper presents an application tool based on an accelerometer, call SensorFall to detect and report the acceleration caused by a fall, which allows sending alerts in the form of SMS, phone call, or by location using the GPS. We have implemented and verified the SensorFall in various environments, such as a hospital or a normal daily life for the elderly, also implemented the system calibration in order to adapt better the living conditions of each person. The results show that it performs well. 相似文献
60.
Sangram Keshari Pradhan Binod Kumar Roul 《Journal of Sol-Gel Science and Technology》2012,64(2):375-380
Impurity free monophasic rhombohedral BiFeO3 (BFO) nanoparticles are synthesized by sol?Cgel method. Effect of processing technique and particle size are found to influence the dielectric, ferroelectric, magnetic and leakage behavior of BFO ceramic prepared by sol?Cgel as well as conventional solid state reaction route. From XRD analysis it is observed that bulk BFO sample showed rhombohedral structure (R3c) along with other impurity phases, which become suppressed with the decrease of particles size to few nanometers. The dielectric behavior and leakage current characteristic of the samples were improved significantly in nanoparticles of BFO. Ferroelectric hysteresis loops of sintered bulk BFO ceramic is found to change its shape from semi elliptical lossy P?CE features to a typical ferroelectric feature with improved remnant and saturation polarization value for the particle size down to nanometer scale. Furthermore, BFO nanoparticles also showed a good ferromagnetic M?CH hysteresis loop with enhanced saturation magnetization value of 0.138?emu/mg. 相似文献