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1.
The complex relative dielectric function, dielectric loss tangent, electric modulus, alternating current
electrical conductivity and impedance spectra of ethylene glycol oligomers (EGOs) i.e., ethylene glycol,
diethylene glycol and poly(ethylene glycol)s of average molecular weight 200, 300, 400 and 600 g mol-1
have been investigated in the frequency range 20 Hz to 1 MHz at 25 °C. These EGOs show
the low frequency dielectric/electrical dispersion due to electrode polarization and ionic conduction effects.
The ‘master curves representation’ of the real and imaginary parts of the intensive dielectric/electrical
functions were used to evaluate the relaxation times corresponding to these effects processes. The comparative
dielectric study of EGOs confirms that the values of low frequency relaxation times and direct current electrical
conductivity are influenced by the chain flexibility and its random coiling. 相似文献
2.
The complex dielectric constant ?∗(ω)=?′−j?″, electric modulus M∗(ω)=M′+jM″, impedance Z∗(ω)=Z′−jZ″ and ac conductivity dispersion behaviour of 5, 10 and 15 wt% concentration aqueous solutions of poly(vinyl alcohol) (PVA) (14?000 and 77?000 g mol−1) and poly(vinyl pyrrolidone) (PVP) (24?000, 40?000 and 360?000 g mol−1) and their binary mixtures were investigated in the frequency range 20 Hz to 1 MHz at 25 °C. Analysis of dielectric constant values confirms that hydrophilic effect of PVA in aqueous solution increases the real part of dielectric constant ?′, whereas for aqueous PVP solutions the hydrophobic effect masks the hydrophilic effect, which reduces ?′ values below 10 kHz. Low-frequency dielectric constant of these aqueous polymeric systems is sensitive to ionic conduction and electrode polarization. The monotonous change in various electrical properties with change in volume percentage of mixture constituents indicates that individual aqueous polymer system retains their own electrical properties in the aqueous two-phase polymeric system. 相似文献
3.
Basavaprabhu H. Nataraj Sonu K. Shivanna Prabha Rao Ravinder Nagpal Pradip V. Behare 《Food science and biotechnology》2021,30(4):487
Over the years, the attempts to elucidate the role of beneficial microorganisms in shaping human health are becoming fairly apparent. The functional impact conferred by such microbes is not only transmitted by viable cells or their metabolites but also through non-viable cells. Extensive research to unveil the protective action of such wonder bugs has resulted in categorizing the beneficial microflora and their bioactive metabolites into a variety of functional biotic concepts based on their intended applications in various forms. In the modern era, these are often termed as probiotics, prebiotics, synbiotics, postbiotics, next-generation probiotics, psychobiotics, oncobiotics, pharmabiotics, and metabiotics. Currently, the concept of traditional probiotics is being widened to include microbes beyond lactic acid bacteria. Indeed, this diversification has broadened the functional food portfolio from food to pharmaceuticals. In this context, the present review aims to summarize the existing biotic concepts and their differences thereof. 相似文献
4.
Neural Computing and Applications - The crow search algorithm (CSA) is a recently proposed population-based optimization algorithm for continuous optimization. Since the original CSA searches for a... 相似文献
5.
Wireless Networks - In wireless sensor networks, coverage and connectivity are the fundamental problems for monitoring the targets and guaranteed information dissemination to the far away base... 相似文献
6.
This paper describes an experimental method for determining the maximum areal density achievable for a given head-to-tape interface (HTI). Using this method, we can calculate amplitude and bit-shift error rates during dropouts for the areal density the HTI is originally designed for, and beyond. First, the read-back waveform is sampled to obtain the amplitude distribution of signal samples below 50% clip level at each areal density. Second, the channel-transfer-function variation is investigated during a dropout to study its effect on the bitshift error rate. Third, empirical relationships between the areal density and an rms-to-rms signal-to-noise ratio (SNR) are obtained. Based on the above information, a theoretical model is presented that predicts the error rate for each areal density after a write skip (defined here as the soft-error rate). The calculated soft-error rate agrees well with its experimental counterpart. The technique presented here is useful in determining the upper limit of the HTI used in the paper. 相似文献
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8.
Manash Aniket Singh Rakesh Kumar Kumar Vivek Das Shashank Bhushan Kumar Singh Sonu Kumar Nishant Shah Jyoti Kotnala R. K. 《Journal of Materials Science: Materials in Electronics》2022,33(28):22103-22118
Journal of Materials Science: Materials in Electronics - In recent years, alkali metal substituted spinel magnesium ferrites have been considered as potential materials for the fabrication of... 相似文献
9.
Yanjun Liu Timothy Moural Sonu Koirala B K Jonathan Hernandez Zhongjian Shen Andrei Alyokhin Fang Zhu 《International journal of molecular sciences》2021,22(21)
Arthropod Glutathione S-transferases (GSTs) constitute a large family of multifunctional enzymes that are mainly associated with xenobiotic or stress adaptation. GST-mediated xenobiotic adaptation takes place through direct metabolism or sequestration of xenobiotics, and/or indirectly by providing protection against oxidative stress induced by xenobiotic exposure. To date, the roles of GSTs in xenobiotic adaptation in the Colorado potato beetle (CPB), a notorious agricultural pest of plants within Solanaceae, have not been well studied. Here, we functionally expressed and characterized an unclassified-class GST, LdGSTu1. The three-dimensional structure of the LdGSTu1 was solved with a resolution up to 1.8 Å by X-ray crystallography. The signature motif VSDGPPSL was identified in the “G-site”, and it contains the catalytically active residue Ser14. Recombinant LdGSTu1 was used to determine enzyme activity and kinetic parameters using 1-chloro-2, 4-dinitrobenzene (CDNB), GSH, p-nitrophenyl acetate (PNA) as substrates. The enzyme kinetic parameters and enzyme-substrate interaction studies demonstrated that LdGSTu1 could catalyze the conjugation of GSH to both CDNB and PNA, with a higher turnover number for CDNB than PNA. The LdGSTu1 enzyme inhibition assays demonstrated that the enzymatic conjugation of GSH to CDNB was inhibited by multiple pesticides, suggesting a potential function of LdGSTu1 in xenobiotic adaptation. 相似文献
10.
This paper presents an analytical and numerical investigation of a circularly polarized beam propagating along the static magnetic field parallel to oscillating magnetic field in plasma at relativistic intensities. In the high intensity regime, such a magnetic field is created by the pulse itself. The authors have identified three regimes of propagation taking into account the relativistic mass correction. Based on WKB and paraxial ray theory, an appropriate expression for a dielectric tensor has been evaluated in the presence of an externally applied magnetic field. The natural electromagnetic modes are circularly polarized. Consequently, extraordinary and ordinary modes propagate, which are significantly affected due to the relativistic mechanism. The regimes are characterized by dimensionless power and beamwidth, characterizing the nature of propagation as steady divergence, oscillatory divergence and self-focusing. Numerical computations are presented and discussed for typical parameters of laser plasma interaction; defined through critical parameters, namely cyclotron-to-beam frequency (Ω c ), plasma-to-beam frequency (Ω p ) and beam power for arbitrary large intensities. 相似文献