TRANES Spectra of Fluorescence Probes in Lipid Bilayer Membranes: An Assessment of Population Heterogeneity and Dynamics

Time-resolved fluorescence of eight fluorescence probes were studied in EggPC bilayer membrane vesicles. Emission wavelength dependent fluorescence decays were analyzed in a model-independent way to obtain time resolved area normalized emission spectra (TRANES). The TRANES spectra of the probes studied were classified into four types: (1) spectra that are identical at all time (one emissive species), (2) spectra that show an isoemissive point (two emissive species), (3) spectra that shift continuously with time (slow solvation dynamics or multiple species), and (4) spectra that shift for a short time and thereafter one or two emissive species are indicated. The TRANES spectra of these eight probes, except RH421, belong to the type 1, 2, or 4. The continuous shift of the TRANES spectra that was observed for the probe RH421 is attributed to multiple ground state species and not due to slow solvation dynamics.     

Determination of gold in low grade ores and concentrates by anion exchange separation followed by neutron activation

The beneficiation of tailings from Kolar Gold Mines involves the flotation of sulphides. Appreciable amounts of arsenic and antimony are expected to accompany gold in this process. The activation analysis of gold in these samples is facilitated by a preseparation of gold from arsenic and antimony. The present paper describes a method for the rapid analysis of gold in the concentration range 0.5 to 50 ppm using a simple pre-irradiation separation, with the recovery of gold being evaluated by an isotope dilution technique using¹⁹⁸Au tracer.     

Synthesis,Spectroscopic and Crystal Structure Analysis of <Emphasis Type="Italic">N</Emphasis>-[imidazolidin-2-ylidene]-5-(thien-2-yl)[1,3,4]thiadiazole-2-amine

The crystal structure of the title compound has been determined. The compound crystallizes in the monoclinic space group P2₁/c with a = 5.9885(2) Å, b = 14.7345(4) Å, c = 12.3719(4) Å, β = 96.655(5)°, V = 1084.31(8) Å³, z = 4. An intramolecular N–H···N hydrogen bond forms a pseudo-six-membered ring with graph set S ¹ ₁(6). The crystal structure is stabilized by intermolecular interactions of the type N–H···N and C–H···N. The packing motifs in accordance with Etter’s analysis are R ² ₂(8) corresponding to N–H···N dimer and that generated by the chain is C(7).     

The capacitated multiple allocation hub location problem: Formulations and algorithms

In this paper we consider and present formulations and solution approaches for the capacitated multiple allocation hub location problem. We present a new mixed integer linear programming formulation for the problem. We also construct an efficient heuristic algorithm, using shortest paths. We incorporate the upper bound obtained from this heuristic in a linear-programming-based branch-and-bound solution procedure. We present the results of extensive computational experience with both the heuristic and the exact methods.     

Synthesis,characterization, AC conductivity,and diode properties of polyaniline–CaTiO3 composites

Polyaniline–CaTiO₃ composites of different weight percentages were prepared by in situ polymerization. The prepared composites were characterized by Fourier transform infrared spectroscopy for structural studies, and a morphology analysis was carried out by scanning electron microscopy studies. Real and imaginary parts of the complex impedance were determined for given samples as a function of frequency. Current–voltage and capacitance–voltage measurements were also carried out. The carrier mobility μ values of neat polyaniline and polyaniline–CaTiO₃ composites were found to be 5.37 × 10^?3 and 2.73 × 10^?2, respectively, and a significant enhancement, as compared with the reported data, was observed. Therefore, this study may provide a better route for technological applications in all fields in the near future and can also be represented by a pure electronic model. Copyright © 2013 John Wiley & Sons, Ltd.     

Distribution of uranium at Mumbai Harbour Bay (MHB)

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay. In addition, the Bay is also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. The average value of uranium concentration reported for Indian Bay water at Tarapur and Mumbai is ~3.0 ppb which is comparable with the reported value for Arabian sea. As such the global average is reported to be ~3.3 ppb by Oceanologists. The present study deals with the distribution of uranium in seawater of MHB. The uranium activity in MHB by alpha spectrometry was found to be between 1.0 and 4.4 ppb with an average concentration of 2.5 ppb which is comparable with the earlier reported average activity of 2.6 ppb in the MHB as well as those reported globally. To compare the results obtained by alpha spectrometry, uranium estimation was also carried out using Laser fluorimeter and the levels of uranium concentration have ranged between 0.8 and 4.9 ppb with an average concentration of 2.7 ppb.     

An upwinded state approximate Riemann solver

Stability is achieved in most approximate Riemann solvers through ‘flux upwinding’, where the flux at the interface is arrived at by adding a dissipative term to the average of the left and right flux. Motivated by the existence of a collapsed interface state in the gas‐kinetic Bhatnagar–Gross–Krook (BGK) method, an alternative approach to upwinding is attempted here; an interface state is arrived at by taking an upwinded average of left and right states, and then the flux is calculated as a function of this ‘collapsed’ interface state. This so called ‘state‐upwinding’ approach gives rise to a new scheme called the linearized Riemann solver for the Euler and Navier–Stokes equations. The scheme is shown to be closely associated with the Roe scheme. It is, however, computationally less expensive and gives qualitatively comparable results over a wide range of problems. Most importantly, this scheme is found to preserve stationary contacts while not exhibiting the carbuncle phenomenon which plagues the Roe and other contact‐preserving schemes. The scheme is therefore motivated as a new starting point to analyze the origin of the carbuncle phenomenon. Copyright © 2011 John Wiley & Sons, Ltd.