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131.
Vinod Chandra V. Ravishankar 《The European Physical Journal C - Particles and Fields》2009,59(3):705-714
We study the viscosity and thermodynamic properties of QGP at RHIC by employing the recently extracted equilibrium distribution
functions from two hot QCD equations of state of O(g
5) and O(g
6ln (1/g)), respectively. After obtaining the temperature dependence of the energy density and the entropy density, we focus our attention
on the determination of the shear viscosity for a rapidly expanding interacting plasma, as a function of temperature. We find
that the interactions significantly decrease the shear viscosity. They decrease the viscosity to entropy density ratio,
as well. 相似文献
132.
Vinod Chandra V. Ravishankar 《The European Physical Journal C - Particles and Fields》2009,64(1):63-72
We propose a quasi-particle model to describe the lattice QCD equation of state for pure SU(3) gauge theory in its deconfined
state, for T≥1.5T
c. The method involves mapping the interaction part of the equation of state to an effective fugacity of otherwise non-interacting
quasi-gluons. We find that this mapping is exact. Using the quasi-gluon distribution function, we determine the energy density
and the modified dispersion relation for the single particle energy, in which the trace anomaly is manifest. As an application,
we first determine the Debye mass, and then the important transport parameters, viz., the shear viscosity, η, and the shear viscosity to entropy density ratio, h/S\eta/{\mathcal{S}}. We find that both η and h/S\eta/{\mathcal{S}} are sensitive to the interactions, and that the interactions significantly lower both η and h/S\eta/\mathcal{S}. 相似文献
133.
Amit Aran Soumika Munshi Vinod K. Beri Arun K. Gupta 《Optics and Lasers in Engineering》2009,47(6):636-643
This paper reports a morphological phase-only correlation technique based on bit-map representation for recognition of color as well as grey images in a hybrid digital-optical correlation architecture. The color image is decomposed into its R, G and B components, and each component is further decomposed into eight disjoint elementary images depending upon the bit-map representation of the color value at each pixel. Bit-map representation of the pixel values of an image reduces the required computational time. A set of twenty-four disjoint wavelet-modified binary phase-only filters (WBPOFs) are generated from these bit-map decomposed images. The target image is similarly decomposed into eight disjoint images each of R, G and B and their digital Fourier transforms multiplied with the corresponding WBPOFs. The product functions thus obtained are added up to form a single resultant product function, whose optical Fourier transformation gives the correlation peaks for the presence of R, G and B components in the image. The single product function overcomes the necessity of obtaining the final optical Fourier transformation of the R, G and B components separately. The novelty of this approach lies in the fact that the WBPOFs synthesized by this procedure are thus able to identify both colored as well as gray images and can tolerate salt-and-pepper noise to a considerable extent. 相似文献
134.
The condensation of 3-amino-1H-1,2,4-triazole with benzaldehyde and terephthalaldehyde provides the bidentate and tetradentate Schiff bases 1,2,4-triazolo-3-imino-benzene L1H and 1,4-bis(1,2,4-triazolo-3-imino)benzene L2H2, respectively. The well characterized Schiff bases were allowed to react with cis-Ru(bpy)2Cl2 · 2H2O. Isomers of the mononuclear complexes Ru(bpy)2L1]PF6 · NH4PF6 (1a, N4) and [Ru(bpy)2L1]PF6 · 0.5NH4PF6 (1b, N2), and the dinuclear Ru(II) complexes [Ru(bpy)2L2Ru(bpy)2](PF6)2 · NH4PF6 (2a, N4N4), [Ru(bpy)2L2Ru(bpy)2](PF6)2 · NH4PF6 · 2H2O (2b, N2N2) and [Ru(bpy)2L2Ru(bpy)2](PF6)3 · NH4PF6 (2c, Ru(II)-Ru(III)) were separated by column chromatography and characterized by their elemental analysis, FAB mass and spectral (IR, NMR, UV–Vis) data. The data obtained suggest that the ligands are bound to the metal centre via the N4 and N2 atoms of the triazole moiety along with the N (imine) atom. The complexes display metal-to-ligand charge-transfer (MLCT) transitions in the visible region from the dπ(RuII) → π∗L transition. Highly intense ligand-based π→π∗ transitions are observed in the UV region. A dual emission occurs from the N2 and N2N2 isomers. 相似文献
135.
Albert Koulman Gary Woffendin Vinod K. Narayana Helen Welchman Catharina Crone Dietrich A. Volmer 《Rapid communications in mass spectrometry : RCM》2009,23(10):1411-1418
Most analytical methods in metabolomics are based on one of two strategies. The first strategy is aimed at specifically analysing a limited number of known metabolites or compound classes. Alternatively, an unbiased approach can be used for profiling as many features as possible in a given metabolome without prior knowledge of the identity of these features. Using high‐resolution mass spectrometry with instruments capable of measuring m/z ratios with sufficiently low mass measurement uncertainties and simultaneous high scan speeds, it is possible to combine these two strategies, allowing unbiased profiling of biological samples and targeted analysis of specific compounds at the same time without compromises. Such high mass accuracy and mass resolving power reduces the number of candidate metabolites occupying the same retention time and m/z ratio space to a minimum. In this study, we demonstrate how targeted analysis of phospholipids as well as unbiased profiling is achievable using a benchtop orbitrap instrument after high‐speed reversed‐phase chromatography. The ability to apply both strategies in one experiment is an important step forward in comprehensive analysis of the metabolome. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
136.
The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent
proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject
to intense research. Understanding the details of the photophysics of these reporters is essential for accurate interpretation
of the biological and biochemical processes illuminated by fluorescent proteins. Some aspects of the complex photophysics
of fluorescent proteins can only be observed and understood at the single-molecule level, which removes averaging inherent
to ensemble studies. In this paper we review how single-molecule emission detection has helped understanding of the complex
photophysics of fluorescent proteins.
相似文献
Vinod SubramaniamEmail: |
137.
Kulkarni MJ Vinod VP Umasankar PK Patole MS Rao M 《Rapid communications in mass spectrometry : RCM》2006,20(18):2769-2772
Here we demonstrate for the first time the application of intact cell matrix-assisted laser desorption/ionization mass spectrometry (ICM-MS) to study the regulation of protein expression. This technique can be extended to screen the drugs that inhibit protein synthesis in various diseases. We have used Escherichia coli cells expressing a recombinant glutathione-S-transferase (GST) gene under an arabinose-inducible promoter as a model system. Using ICM-MS analysis, we have detected a 28 kDa peak corresponding to the production of recombinant GST under the arabinose-induced condition. Furthermore, recombinant GST protein was purified by a single-step affinity purification using a glutathione Sepharose 4B affinity column from arabinose-induced E. coli cells. The purified GST protein was found to be a 28 kDa protein by MALDI analysis suggesting the arabinose-induced protein is indeed GST. The regulation of protein expression was studied using glucose as an alternative metabolite. The glucose-mediated regulation of the ara-operon was followed using the ICM-MS technique. All the results obtained from ICM-MS data were validated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The present technique can be extended for in vivo screening of drugs and it holds tremendous potential to discover novel drugs against specific protein expressions in different diseases. 相似文献
138.
Krishna V 《The Journal of chemical physics》2006,125(3):34711
A first principles treatment of the vibrational dynamics of molecular chemisorbates on metal surfaces is presented. It is shown that the mean field quantum evolution of the vibrational position operator is determined by a quantum Langevin equation with an electronic friction. In the mean field limit, the quantum noise and friction are related by the quantum fluctuation-dissipation theorem. The classical limit of this model is shown to agree with previously proposed models. A criterion is presented to describe the validity of the weak-coupling approximation and equations of motion for the dynamics in the presence of strong nonadiabatic coupling to electron-hole pairs are presented. 相似文献
139.
Adsorption of Safranin-T from wastewater using waste materials- activated carbon and activated rice husks 总被引:6,自引:0,他引:6
Gupta VK Mittal A Jain R Mathur M Sikarwar S 《Journal of colloid and interface science》2006,303(1):80-86
Textile effluents are major industrial polluters because of high color content, about 15% unfixed dyes and salts. The present paper is aimed to investigate and develop cheap adsorption methods for color removal from wastewater using waste materials activated carbon and activated rice husk-as adsorbents. The method was employed for the removal of Safranin-T and the influence of various factors such as adsorbent dose, adsorbate concentration, particle size, temperature, contact time, and pH was studied. The adsorption of the dye over both the adsorbents was found to follow Langmuir and Freundlich adsorption isotherm models. Based on these models, different useful thermodynamic parameters have been evaluated for both the adsorption processes. The adsorption of Safranin-T over activated carbon and activated rice husks follows first-order kinetics and the rate constants for the adsorption processes decrease with increase in temperature. 相似文献
140.
Vinod D. Chaudhari 《Tetrahedron》2006,62(18):4349-4354
The d-glucose derived α,β-unsaturated ester 5 on 1,2-acetonide deprotection, oxidative diol cleavage followed by treatment with N-benzylamine in the presence of NaBH3CN undergoes reductive amination and a concomitant intramolecular conjugate addition reaction leading to the formation of dihydroxypyrrolidine-ester 6a and monohydroxypyrrolidine-γ-lactone 6b. Intermediates 6a and 6b were efficiently converted to (−)-lentiginosine 3a, its 8a-epimer 3b, and pyrrolizidine azasugar 4 in good overall yield. 相似文献