bluuebunny/crossref_metadata_2025 huggingface dataset:
Tungsten Chemistry in Alkali Chloride Melts
Authors: Danilov Danil A. , Volkovich Vladimir A. , Vasin Boris D. , Polovov Ilya B. , Griffiths Trevor R.
Published: February 2015

Speciation of tungsten in alkali chloride melts (based on NaCl-2CsCl, NaCl-KCl and 3LiCl-2KCl mixtures) was studied between 550 and 750◦C using electronic absorption spectroscopy. OnlyW(IV) and W(V) chloro and oxychloro species can be stabilized under the conditions studied. Tungsten(IV) chloride ions are very sensitive to oxide/hydroxide impurities present in the melt. Anodic dissolution ofWmetal at anodic current densities in the range of 0.005 - 0.1 A/cm2 produces only [WCl6]2− ions that can be electrochemically (on a glassy carbon anode) oxidized to [WCl6]−. Small amounts of oxide ions present in the melt result in a gradual conversion of W(IV) chloro species intoW(IV) oxychloro species. In the presence of O2 in the atmosphere [WCl6]2− is oxidized into the tungsten(V) species [WOCl5]2−. Dissolution of tungsten hexachloride, WCl6, in an NaCl-2CsCl melt initially yields [WCl6]2− (due to disproportionation). Reaction of metallic tungsten with Pd(II)-containing melts results in the formation of [WCl6]2− species. The main spectroscopic parameters of [WCl6]2− and [WCl6]− complex ions were calculated.
Spectroelectrochemical Study of Neptunium in Molten LiCl-KCl Eutectic
Authors: Polovov Ilya B. , Sharrad Clint A. , May Iain , Volkovich Vladimir A. , Vasin Boris D.
Published: February 2015

Neptunium behaviour in an LiCl-KCl eutectic melt at 723 K was studied using spectroelectrochemistry. Cathodic reduction of neptunium(IV)-containing melts led to the formation of Np(III) ions and then neptunium metal. Electronic absorption spectra of Np(IV) and Np(III) chloro species in LiCl-KCl melt were recorded and resolved into individual Gaussian bands. The nature of neptunium complex ions in the melt is discussed.
Preparation of Perpendicular GdFeCo Magnetic Thin Films with Pulse Electrodeposition Technique Utilizing Molten Salt as Electrolyte
Authors: Yang Chao-Chen , Shu Min-Fong
Published: February 2015

We have utilized ZnCl2-dimethylsulfone (DMSO2) as the electrolyte with added GdCl3, FeCl2, and CoCl2, for electrodepositing a perpendicular GdFeCo magnetic thin film. The reaction at the electrode surface and the electrical conductivity of the ionic substance at different ionic concentrations were studied by cyclic voltammetry and a computerized direct current method. Moreover, the electrodeposition of the GdFeCo thin film was determined by a pulse potential method. Relation between the composition of the deposited thin film and control parameters including applied potentials was determined by EDS analysis. An amorphous structure and the thickness of the thin film were obtained by TEM analysis. Its roughness and uniformity were determined by AFM analysis. Meanwhile, a perpendicular magnetic property and pinning magnetic domain of the thin film were analyzed from results of AGM and MFM.
Interaction of Pipeline Materials with Molten Fluoride Salts
Authors: Šimo Tomáš , Matal Oldřich , Nesvadba Lukáś , Dvořák Vladimír , Kanický Viktor , Sulovský Petr , Machát Jiří
Published: February 2015

Molten fluoride salts are very promising carriers for the transport of large amounts of heat for example from a high temperature nuclear reactor to a plant which generates hydrogen by chemical processes or from a nuclear reactor to a heat exchanger being a part of the equipment needed to realize the Brayton cycle with a very high power efficiency. Therefore, in the framework of our project, experimental and theoretical investigations of the interactions of fluoride salts as heat carriers needed as high potential and structural materials for pipelines in order to transport heat at temperatures above 600◦C were started. Experimental investigations of Fe-based and Ni-based materials in molten fluoride salts at high temperatures and with different exposure times were performed. Two components salts (LiF-NaF and NaF-NaBF4) and three components salts (LiF-NaF-ZrF4 and LiF-NaF-RbF) were chosen in the experiments. The salt analysis was focussed on the content of metallic elements before and after the exposure of the samples to the salt melts. It was done by inductively coupled plasma-optical emission spectrometry (ICP-OES) and by titrimetric techniques. The thickness of the material zone affected by the salt melts, characterized by an enriched / reduced content of elements in comparison to the mean original content, and the material attacked zone, characterized by very tiny channels or chains of pores or pits formed preferably at grain boundaries, were the subject of the analysis performed by electron microscopy / microprobe techniques. Theoretical models for the transport of elements in the material samples exposed to salt melts using experimental data were also developed.
Truncated Painlevé Expansion – A Unified Approach to Exact Solutions and Dromion Interactions of (2+1)-Dimensional Nonlinear Systems
Authors: Radha Ramaswamy , Tang Xiao Yan , Lou Sen Yue
Published: February 2015

In this paper, we formulate a method wherein we harness the results of the Painlevé analysis to generate the solutions of the (2+1)-dimensional Ablowitz-Kaup-Newell-Segur system completely in terms of the arbitrary functions. This method is mainly based on the results of the truncated Painlevé expansion. Different types of interactions among dromions are deeply understood both analytically and numerically. Especially, different from the traditional viewpoint, we point out that the soliton (dromion) fission and fusion may be an approximate phenomenon.
Local Spacetime Dynamics, the Einstein-Straus Vacuole and the PIONEER Anomaly: A New Access to these Problems
Authors: Fahr Hans-Jörg , Siewert Mark
Published: February 2015

The question concerning the extent of the local spacetime has often been raised. At what circumsolar distance the well known Robertson-Walker spacetime of our expanding universe may become a valid approximation? Inside of that distance a local Schwarzschild metric, which permits to explain the Keplerian motions of planets within the frame of general relativity, must be applicable.We briefly analyze the historical answer to that question given by Einstein, Straus and their followers and show that till now this answer is unsatisfactory in many respects.

We revisit the problem of local spacetime geometries in the light of their effects on local photon propagation in view of the radiopropagation phenomena detected with the NASA spaceprobes PIONEER-10/11, waiting for a satisfying answer for several decades now. Comparing radiosignals outgoing from the earth to the probe and ingoing again from the probe to the receiver on earth do show anomalous frequency shifts which presently find no explanation by anomalous non-Newtonian decelerations of these probes. Therefore we study cosmological conditions for the transfer of radiosignals between the earth and these distant probes based on time dependent local spacetime geometries. First we study the cosmological redshift of radiophotons during their propagation to the spaceprobe and show that this shift in fact explains the registered PIONEER phenomenon under the assumption that the full cosmological expansion of the universe also takes place locally. Though yielding the right magnitude, one finds that this assumption leads to a redshift instead of the observed blueshift. We then, however, show that theoretically motivated forms of time dependent local spacetime metrices in fact lead to a blueshift of the needed magnitude. The appropriate local space vacuole is characterized by a Schwarzschild metric of a central mass increasing with cosmic time. Though it is clear that further studies of this effect have to be carried out to give more credit and verification to this hypothetical result, nevertheless more careful hightech radiotracking of freely flying spaceprobes may do a usefull job in confirming a completely unexpected, but cosmologically highly relevant phenomenon.
Critical Behaviour of the Ferromagnetic Spin-3/2 – Blume-Emery-Griffiths Model with Repulsive Biquadratic Coupling
Authors: Pınar M. Ali , Keskin Mustafa , Erdinç Ahmet , Canko Osman
Published: February 2015

The critical behaviour of the ferromagnetic spin-3/2 Blume-Emery-Griffiths model with repulsive biquadratic coupling in the absence and presence of an external magnetic field is studied by using the lowest approximation of the cluster variation method, which is identical with the mean-field approximation. Thermal variations of the order parameters are investigated for different values of the interaction parameters and the external magnetic field. The complete phase diagrams of the system are calculated in the (kT/J,K/J), (kT/J,D/J) and (kT /J,H/J) planes. Five new phase diagram topologies are obtained, which are either absent from previous approaches or have gone unnoticed. A detailed discussion and comparison of the phase diagrams is made.
Phase Polymorphism, Molecular Motions and Structural Changes in [Cr(NH3)6](ClO4)3
Authors: Mikuli Edward , Górska Natalia , Wróbel Stanisław , Ściesińskic Jacek , Ściesińska Ewa
Published: February 2015

A phase transition in [Cr(NH3)6](ClO4)3 at Th
c = 293.5 K (on heating) and Tc
c = 293.0 K (on cooling) was determined by differential scanning calorimetry. The temperature dependences of the full width at half maximum of the bands connected with ρr(NH3)F1u and δd(ClO)E modes suggest that the discovered phase transition is not connected with drastic changes in the speed of reorientational motions of the NH3 ligands nor the ClO4 − anions. Temperature dependence of the FT-FIR spectra and the diffraction patterns show that the discovered phase transition is caused by a change in the crystal structure.
Compact 11S Helium Wave Functions; an 8-Parameter Wave Function and its Sensitivity Analysis
Authors: David Carl W.
Published: February 2015

A previously obtained approximate non-relativistic Helium wave function is improved significantly coming within 0.02% of the “exact” value with 8 terms. The sensitivity of this final result to the parameters in the wave function is examined.
The Equation of a Light Leptonic Magnetic Monopole and its Experimental Aspects
Authors: Lochak Georges
Published: February 2015

The present theory is closely related to Dirac’s equation of the electron, but not to his magnetic monopole theory, except for his relation between electric and magnetic charge. The theory is based on the fact, that the massless Dirac equation admits a second electromagnetic coupling, deduced from a pseudo-scalar gauge invariance. The equation thus obtained has the symmetry laws of a massless leptonic, magnetic monopole, able to interact weakly. We give a more precise form of the Dirac relation between electric and magnetic charges and a quantum form of the Poincar´e first integral. In the Weyl representation our equation splits into P-conjugated monopole and antimonopole equations with the correct electromagnetic coupling and opposite chiralities, predicted by P. Curie. Charge-conjugated monopoles are symmetric in space and not in time (contrary to the electric particles), an important fact for the vacuum polarization. Our monopoles are magnetically excited neutrinos, which leads to experimental consequences. These monopoles are assumed to be produced by electromagnetic pulses or arcs, leading to nuclear transmutations and, for beta radioactive elements, a shortening of the life time and the emission of monopoles instead of neutrinos in a magnetic field. A corresponding discussion is given.
Estrada Index of Benzenoid Hydrocarbons
Authors: Gutman Ivan , Radenković Slavko
Published: February 2015

A structure-descriptor EE, recently proposed by Estrada, is examined. If λ1, λ2, . . . ,λn are the eigenvalues of the molecular graph, then

. In the case of benzenoid hydrocarbons with n carbon atoms and m carbon-carbon bonds, EE is found to be accurately approximated by means of the formula a1 n cosh (√2m/n)+a2, where a1 ≈ 1.098 and a2 = −0.64 are empirically determined fitting constants. Within classes of benzenoid isomers (which all have equal n and m), the Estrada index is linearly proportional to the number of bay regions.
Transferable Deformation-Dipole Model for Ionic Materials
Authors: Karaman Ali , Akdeniz Zehra , Tosi Mario P.
Published: February 2015

A model for the ionic interactions in polyvalent metal halides was originally built for chloroaluminate clusters using an analysis of data on static and dynamic structure of their molecular monomers [for a review see M. P. Tosi, Phys. Chem. Liquids 43, 409 (2005)]. Recently, by continuing the deformation-dipole model calculations, the transferability of the halogen parameters was tested through the calculation of the structure of alkali halides and alkaline-earth halides. In this work we test the usefulness of the deformation-dipole model in the study of ionic materials by examining the transferability of the overlap parameters for the halogen ions across families of halide compounds. Following a comparative discussion of alkali and alkaline-earth halide monomers near equilibrium, results on alkaline-earth halides are given. By using the transferable ionic potential model we also calculate the equilibrium structure of the molecular clusters, as well as the vibrational frequencies of ACl4 compounds (where A = U, Np, Pu, Am and Th).
Phase Densities of Molten Binary Mixtures of Alkali Halogenides with Limited Mutual Solubility
Authors: Lockett Vera N. , Rukavishnikova Irina V. , Stepanov Viktor P.
Published: February 2015

The densities of binary mixtures of LiF with CsCl, KBr, RbBr, CsBr, KI, RbI and CsI have been investigated at 1093 - 1253 K. For the system LiF with KBr the dependence of the density on the temperature was measured up to the critical point, where the system became single-phased, and the critical behaviour was evaluated. The critical exponent of the order parameter, which was found from the density measurements, is close to 0.5.
Influence of Chromium Ions on the Dielectric Properties of the PbO-Ga2O3-P2O5 Glass System
Authors: Flower Gnanaprakasm Little , Reddy Maddireddy Srinivasa , Reddy Musugu Venkata Ramana , Veeraiah Nalluri
Published: February 2015

PbO-Ga2O3-P2O5 glasses containing different amounts of Cr2O3, ranging from 0 to 1.0 mol%, were prepared. The dielectric properties (viz., constant ε’, loss tanδ , ac conductivity σac over a wide range of frequencies and temperatures, dielectric breakdown strength) have been studied as a function of the concentration of chromium ions. An anomaly has been observed in the dielectric properties of these glasses, when the concentration of Cr2O3 is about 0.4 mol%. This anomaly has been explained in the light of different oxidation states of chromium ions with the aid of data of differential thermal analysis and optical absorption spectra of these glasses.
Investigation of the EPR Parameters of a Trigonal Dy3+ Center in La2Mg3(NO3)12 · 24H2O Crystal
Authors: Dong Hui-Ning , Wu Shao-Yi , Keeble David J.
Published: February 2015

The electron paramagnetic resonance parameters g‖ and g⊥ of Dy3+, and the hyperfine structure parameters A‖ and A⊥ of 161Dy3+ and 163Dy3+ in a La2Mg3(NO3)12 · 24H2O crystal are calculated by the perturbation formulas of the EPR parameters for a 4f9 ion in trigonal symmetry. In these formulas, the J-mixing among the 6HJ (J = 15/2, 13/2 and 11/2) states via crystal-field interactions, the mixtures of the states with the same J-value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and the same irreducible representations in the other 20 Kramers doublets ΓX via the crystal-field and orbital angular momentum (or hyperfine structure) are all considered. The crystal-field parameters for the studied Dy3+ center are obtained with the superposition model. The calculated results are in good agreement with the observed values.
The Decomposition Method for Studying a Higher-Order Nonlinear Schrödinger Equation in Atmospheric Dynamics
Authors: Ma Zheng-Yi
Published: February 2015

The Adomian decomposition method is implemented for solving a higher-order nonlinear Schrödinger equation in atmospheric dynamics. By means of Maple, the Adomian polynomials of an obtained series solution have been calculated. The results reported in this paper provide further evidence of the usefulness of Adomian decomposition for obtaining solutions of nonlinear problems.
Fractional Diffusion Equation in Cylindrical Symmetry: A New Derivation
Authors: Zahran Mohsen A.
Published: February 2015

Based on the so-called cylindrical brush structure as a fractal model, we derive the generalized fractional diffusion equation in cylindrical symmetry. Moreover, we derive the fractional calculus and also present the usefulness of fractional ideas in diffusion processes that take place in brush polymer, rheology, and complex systems.
A Gated Four Probe Technique for Field Effect Measurements on Disordered Organic Semiconductors
Authors: von Hauff Elizabeth , Spethmann Nicolas , Parisi Jürgen
Published: February 2015

A gated four probe measurement technique to isolate contact resistances in field effect measurements

on disordered organic semiconductors was investigated. Organic field effect transistors (OFETs) were prepared with two additional electrodes in the contact geometry protruding into the source-drain channel to monitor the variation in potential across the channel. Two high impedance electrometers were used to determine the potential at the contacts. This technique allows to directly determine the magnitude of the parasitic contact resistances between metal contact and organic semiconductor from the drop in potential at the contact regions. The effects of contact resistances, which can falsify measurements on bulk transport parameters such as the field effect mobility, can be then eliminated during material characterization. Additionally, the temperature and electric field dependence of the contact resistances offers valuable information about the charge injection and extraction processes between metal and organic semiconductor. The effects of the four probe geometry, specifically the effect of the channel electrodes on the current-voltage characteristics, of hole transport in a polythiophene (P3HT) OFET with Au contacts were investigated and found not to influence device performance, except at currents « 1 nA. The IV characteristics were shown to follow the expected FET behaviour. From the variation in potential along the channel it was found that contact resistances at the source contact (charge injecting contact) are minimal while contact resistances at the

drain contact (charge extracting contact) are significant, resulting in a much lower effective sourcedrain voltage than that applied to the device.
Error Analysis of the Oscillating Cup Method for Viscosity Measurements of Molten Salts
Authors: Tolbaru Dumitru , Popescu Ana-Maria , Zuca Stefania
Published: February 2015

The errors in viscosity measurements by the oscillating cup method were calculated as a function of the limit of accuracy imposed by the uncertainty in determining the constants of the oscillating system R, I, T0, δ0 and the limit of precision resulting from errors in determining the experimental parameters δ , T , h, ρ.

Thus, by evaluating the fractional error of each of the parameters and implicitly its distinct contribution to the total standard error, it was established that the “meniscus error” Δh, which is difficult to be controlled or avoided, represents the major source of imprecision of oscillating cup viscometers.
Phase Behaviour and FTIR Spectra of Ionic Liquids: The Mixtures of 1-Butyl-1-methylpyrrolidinium Chloride and TaCl5
Authors: Babushkina Olga B
Published: February 2015

A series of ionic liquids consisting of 1-butyl-1-methylpyrrolidinium chloride (Pyr14Cl) and TaCl5 at molar ratios of Pyr14Cl in the range of 0.85 - 0.20 was synthesized. They exhibit potential application as electrolytes for the electrochemical deposition of tantalum. The thermal behaviour of the Pyr14Cl-TaCl5 mixtures was investigated, using differential scanning calorimetry (DSC) to estimate the range of thermal stability and to determine the optimal compositions for electrochemical trials. The Pyr14Cl-TaCl5 mixtures formed stoichiometric 3 : 2 and 2 : 3 crystalline phases with melting points of 70 °C and 130 °C, respectively, characterized by entropies of fusion of 13.6 JK−1 mol−1 and 10.1 JK−1 mol−1. The mixtures with molar fractions of Pyr14Cl equal to 0.60 and 0.40 were clear and transparent liquids and had the lowest viscosity; they were the most suitable for electrochemical applications.

FTIR spectra of the Pyr14Cl-TaCl5 mixtures allowed to get insight into inter-ionic interactions and the nature of formation of these ionic liquids as a function of the molar ratio of the components.
Spectroscopy and Electrochemistry of Tantalum(V) in 1-Butyl-1-methylpyrrolidinium Trifluoromethanesulfonate
Authors: Babushkina Olga B. , Ekres Silvia , Nauer Gerhard E.
Published: February 2015

FTIR spectroscopic and electrochemical characterizations of tantalum(V) in 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (Pyr14TFMS)-TaCl5 ionic liquids are performed with 5, 15, and 35 mol% TaCl5 as the media for potential electrochemical application. On the basis of FTIR spectra the electrochemical active species are identified as follows: [TaOCl4]−, [TaOCl5]2−, [TaCl5F]−, and [TaCl5F2]2−. The dominant species are the oxochloride complexes of tantalum(V).

Cyclic voltammograms of Pyr14TFMS-TaCl5 mixtures at 80 °C exhibit three reduction peaks: at −0.8 V, −0.9 V, and −2.4 V. The first reduction peak corresponds to the reduction of the oxochloride species of tantalum(V), the second is assigned to the reduction of the mixed chloride-fluoride species of tantalum(V), and the third peak to the further reduction of tantalum.

The spectroscopic data confirm the suggestion that oxochloride complexes of tantalum(V) become the dominant species in ionic liquids with the oxygen-containing functional group [CF3SO3]−, possibly restricting the process of tantalum metal deposition from these ionic liquids.
The Homotopy Perturbation Method for Solving Nonlinear Burgers and New Coupled Modified Korteweg-de Vries Equations
Authors: Zayed Elsayed M. E. , Nofal Taher A. , Gepreel Khaled A.
Published: February 2015

We use the homotopy perturbation method to find the travelling wave solutions of nonlinear Burgers and new coupled modified Korteweg-de Vries equations. The results reveal that the homotopy perturbation method is very effective, convenient and quite accurate to systems of nonlinear equations. It is predicted that the homotopy perturbation method can find wide application in engineering and physics.
Lineshape of a Stochastic Oscillator with Two State Frequency Modulations
Authors: Olszewski Marcin , Sergeev Nikolaj A.
Published: February 2015

The transformations of the lineshape with a fluctuating frequency for the Kubo-Anderson oscillator are considered. Assuming that the frequency of the oscillator fluctuates between two values and the rate of this fluctuation is a stochastic function of the time the analytical expression of the lineshape is obtained. It is assumed that the stochastic fluctuations of the potential barrier for the Kubo-Anderson oscillator lead to the stochastic fluctuations of the frequency. The transformations of the lineshape are extremely sensitive to the function, which describes the distributions of the frequency fluctuations. The obtained expression is applied to the different distributions of the fluctuation frequency rate. It is shown that a unusual type of the motional narrowing phenomenon is observed for the log-normal and log-Lorentzian distribution.
Existence Conditions for Stable Stationary Solitons of the Cubic-Quintic Complex Ginzburg-Landau Equation with a Viscosity Term
Authors: Hong Woo-Pyo
Published: February 2015

We report the existence of a new family of stable stationary solitons in the one-dimensional cubicquintic complex Ginzburg-Landau equation with the viscosity term. By applying the paraxial ray approximation, we obtain the relation between the width and the peak amplitude of the stationary soliton in terms of the model parameters. We find the bistable solitons in the presence of the small viscosity term.We verify the analytical results by direct numerical simulations and show the stability of the stationary solitons. We conclude that the existence condition obtained by the paraxial method may serve as physically more reliable initial condition for stable stationary soliton propagation in the optical system modeled by the one-dimensional cubic-quintic complex Ginzburg-Landau equation with the viscosity term, of which analytical solution is not obtainable with all nonzero parameters.
A Nonlinear Stability Analysis of a Double-Diffusive Magnetized Ferrofluid
Authors: Mahajan Sunil , Mahajan Amit
Published: February 2015

A nonlinear (energy) stability analysis is performed for a magnetized ferrofluid layer, heated and soluted from below, with stress-free boundaries. A rigorous nonlinear stability result is derived by introducing a suitable generalized energy functional. The mathematical emphasis is on how to control the nonlinear terms caused by magnetic body and inertia forces. For ferrofluids we find that the existence of subcritical instabilities is possible, however, it is noted that, in case of a nonferrofluid, the global nonlinear stability Rayleigh number is exactly the same as that for linear instability. For lower values of the magnetic parameters, this coincidence is immediately lost. The effects of the magnetic parameter, M3, and the solute gradient, S1, on the subcritical instability region have also been analyzed. It is shown that with the increase of the magnetic parameter the subcritical instability region between the two theories decreases quickly, while with the increase of the solute gradient the subcritical region expands. We also demonstrate the coupling between the buoyancy and magnetic forces in the nonlinear energy stability analysis.
Electronic Excitation Energy Ttransfer of Prodan-ORB and Laurdan-ORB Systems in Model Phospholipid Membranes
Authors: Kozyra Katarzyna A. , Józefowicz Marek , Heldt Janina R , Heldt Józef
Published: February 2015

Electronic energy transfer between prodan (6-propionyl-2-dimethylaminonaphthalene) and laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) acting as donors and ORB (octadecyl rhodamine B) acting as acceptor in a model system of membranes has been studied by a steady-state fluorescence quenching analysis. Factors determining the energy transfer rate were considered with special attention to the contribution from the spectral heterogeneity of the donor molecules. By analyzing experimental data within the framework of two theoretical models (developed by Stern, Volmer, and Lehrer) of the energy transfer in two-dimensional systems, the limits of the range of possible prodan and laurdan positions with respect to a lipid bilayer have been estimated.
Reconstruction of the Potential Function and its Derivatives for the Diffusion Operator
Authors: Koyunbakan Hikmet , Yilmaz Emrah
Published: February 2015

We solve the inverse nodal problem for the diffusion operator. In particular, we obtain a reconstruction of the potential function and its derivatives using only nodal data. Results are a generalization of Law’s and Yang’s works.
Optical Excitation and Absorption Spectra of C2v and D2d Isomers of CO4
Authors: Jiang Chen-Wei , Xie Rui-Hua , Li Fu-Li
Published: February 2015

Recently the CO4 isomer with C
2vsymmetry has been detected in an experiment [C. S. Jamieson et al., Chem. Phys. Lett. 440, 105 (2007)]. To further characterize this isomer, we report its optical excitation and absorption spectra calculated by the time-dependent density functional theory. Its rich spectral features are compared with those of another stable isomer having D
2d symmetry. Their spectral difference can be an evidence to distinguish the isomers in experiments.
Conformational and Vibrational Analysis of 2,4-, 2,5- and 2,6-Difluorobenzaldehydes by ab initio Hartree-Fock and Density Functional Theory Calculations
Authors: Sağlam Adnan , Ucun Fatih
Published: February 2015

The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments of the two planar O-cis and O-trans rotomers of 2,4-, 2,5- and 2,6-difluorobenzaldehyde have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with the 6-311++G(d,p) basis set level. The calculations were adapted to the CS symmetries of all the molecules. The O-trans rotomers with lower energy of all the compounds have been found as preferential rotomers in the ground state. The mean vibrational deviations between the vibrational frequency values of the two conformers of all the compounds have been shown to increase while the relative energies increase, and so it has been concluded that the higher the relative energy between the two conformers the bigger is the mean vibrational deviation.
Study of Charge Transfer and Structure Factor Calculation of Europium Selenide (EuSe)
Authors: Ariponnammal Shanmuga Sundaram , Rathiha Somasundarapandian Kameswaran
Published: February 2015

The presence of charge transfer in EuSe is analyzed by experimental and theoretical X-ray diffraction data. The direction and amount of charge transfer are inferred by plotting and comparing the structure factor of the components. Thus a charge transfer of 0.22 electrons is obtained in EuSe from europium (Eu) to selenium (Se).
Homotopy Analysis Method for Nonlinear Differential Equations with Fractional Orders
Authors: Liu Yin-Ping , Li Zhi-Bin
Published: February 2015

The aim of this paper is to solve nonlinear differential equations with fractional derivatives by the homotopy analysis method. The fractional derivative is described in Caputo’s sense. It shows that the homotopy analysis method not only is efficient for classical differential equations, but also is a powerful tool for dealing with nonlinear differential equations with fractional derivatives.
Onset of Double Diffusive Convection in a Thermally Modulated Fluid-Saturated Porous Medium
Authors: Bhadauria Beer S. , Sherani Aalam
Published: February 2015

The onset of double diffusive convection in a sparsely packed porous medium was studied under modulated temperature at the boundaries, and a linear stability analysis has been made. The primary temperature field between the walls of the porous layer consisted of a steady part and a timedependent periodic part and the Galerkin method and the Floquet were used. The critical Rayleigh number was found to be a function of frequency and amplitude of modulation, Prandtl number, porous parameter, diffusivity ratio and solute Rayleigh number.
Hardness of a Crystal Lattice as Consequence of Quantum “Freezing” of Atomic Degrees of Freedom
Authors: Pavlov Valeriy , Potapov Alexei , Korosteleva Nina , Khokhlov Vladimir
Published: February 2015

It has been shown that in the classical computer model the “matter of a crystal” has the kinetic and mechanical properties of a dense gas or a simple liquid at any temperature, including the area near the absolute zero. Agreement with the experiment and a stable hard crystal structure with high enough real activation energy (for instance E ≈ 40RTm) can be obtained if quantum effects and especially quantum “freezing” of atomic degrees of freedom are introduced in the model.
Binding and Release of Glutamate from Overoxidized Polypyrrole via an Applied Potential for Application as a Molecular Switch
Authors: Hauff Elizabeth von , Meteleva-Fischer Yulia , Parisi Jürgen , Weiler Reto
Published: February 2015

The controlled binding and release of glutamate from overoxidized polypyrrole (PPy) films via a variable potential was investigated. Glutamate-doped PPy films were electrochemically deposited from aqueous sodium glutamate electrolytes containing the pyrrole monomer. The resulting polymer films were found to have a high degree of roughness, which increased with increasing film thickness. This was also found to correspond to an increase in the glutamate content on the PPy film surface. The glutamate content on the film was in the order of 10−8 m/cm2 depending on the film deposition time. Glutamate was then released from the film into the electrolyte through overoxidization of the PPy layer and an applied potential. The amount of glutamate released from the film was greater than that on the surface of the film indicating that glutamate can be released from the PPy film via an applied potential. The switching behaviour of the polymer electrode, i. e. the repeated binding and release of glutamate to/from the polymer film via a variable potential, was investigated. The glutamate content in the samples was detected via liquid scintillation counting techniques performed on samples prepared with tritium (3H)-marked glutamate.
Speciation of Rhenium in Chloride Melts: Spectroscopic and Electrochemical Study
Authors: Danilov Danil A. , Volkovich Vladimir A. , Vasin Boris D. , Aleksandrov Denis E. , Polovov Ilya B. , Griffiths Trevor R.
Published: February 2015

Speciation of rhenium in high-temperature alkali chloride-based melts was studied using electronic absorption and IR spectroscopy of molten salts and diffuse reflectance spectroscopy of quenched melts. Rhenium was added to the melts by anodic dissolution of the metal (at anodic current densities of 0.005 - 0.05 A/cm2), by reacting Re and ReO2 with Cl2 and HCl, and by dissolving K2[ReCl6]. The melts included 3LiCl-2KCl and NaCl-2CsCl eutectics, an NaCl-KCl equimolar mixture, and pure NaCl, KCl and CsCl between 450 and 850 ◦C. Rhenium was present in the melts as Re(IV) hexachloro-ions, [ReCl6]2−; no evidence of species containing rhenium in oxidation states below four was obtained. The kinetics of [ReCl6]2− disproportionation in molten alkali chlorides were investigated, and the IR spectra of [ReO4]− ions in molten CsCl-CsI and CsI were measured for the first time.
Reprocessing of LiH in Molten Chlorides
Authors: Masset Patrick J. , Gabriel Armand , Poignet Jean-Claude
Published: February 2015

LiH was used as inactive material to stimulate the reprocessing of lithium tritiate in molten chlorides. The electrochemical properties (diffusion coefficients, apparent standard potentials) were measured by means of transient electrochemical techniques (cyclic voltammetry and chronopotentiometry). At 425 ºC the diffusion coefficient and the apparent standard potential were 2.5 · 10−5 cm2 s−1 and −1.8 V vs. Ag/AgCl, respectively. For the process design the LiH solubility was measured by means of DTA to optimize the LiH concentration in the molten phase. In addition electrolysis tests were carried out at 460 ºC with current densities up to 1 A cm−2 over 24 h. These results show that LiH may be reprocessed in molten chlorides consisting in the production of hydrogen gas at the anode and molten metallic lithium at the cathode.
New Applications of the Homotopy Analysis Method
Authors: Elwakil Elsayed Abd Elaty , Abdou Mohamed Aly
Published: February 2015

An analytical technique, namely the homotopy analysis method (HAM), is applied using a computerized symbolic computation to find the approximate and exact solutions of nonlinear evolution equations arising in mathematical physics. The HAM is a strong and easy to use analytic tool for nonlinear problems and does not need small parameters in the equations. The validity and reliability of the method is tested by application on three nonlinear problems, namely theWhitham-Broer-Kaup equations, coupled Korteweg-de Vries equation and coupled Burger’s equations. Comparisons are made between the results of the HAM with the exact solutions. The method is straightforward and concise, and it can also be applied to other nonlinear evolution equations in physics.
Homotrinuclear Spin Cluster with Orbital Degeneracy in a Magnetic Field: Algebraic Dynamic Studies of the Geometric Phase January 25, 2008
Authors: Cheng Ji-Wen , Zhu Qin-Sheng , Kuang Xiao-Yu , Zhang Shi-Xun , Zhang Cai-Xia
Published: February 2015

Based on the homotrinuclear spin cluster having SU(2)⊗SU(2) symmetry with twofold orbital degeneracy τ = 1/2) and the SU(2) algebraic structures of both ŝ and τˆ subspaces in the external magnetic field, we calculate exactly the non-adiabatic energy levels and the cyclic and non-cyclic non-adiabatic geometric phase of the homotrinuclear spin cluster by making use of the method of algebraic dynamics. The solution will show that the Berry phase is much influenced by the parameters N =γs/γτ (γs and γτ are the magnetic momentums of ŝ and τ̂ subspaces, respectively) in addition to ω/Ω in a rotating magnetic field. The change of the Berry phase in the basis state of the system is demonstrated from the changing diagram.
Nitrogen Glow Discharge by a DC Virtual Cathode
Authors: Shager Azza M. , Sroor Amany T. , Tayeb Hoda A. El , Gamal Hoda A. El , Masoud Mohamed M.
Published: February 2015

A DC glow discharge operating with a virtual cathode is studied. The system consists of a solid disc cathode and mesh anode. The discharge occurs in nitrogen gas at the left-hand side of Paschen’s curve. The plasma electron density in the axial direction has been found to be 0.2 · 108 cm−3 at 2 cm from the mesh. The electron temperature peak value has been found to be 3.5 eV at 6 cm from the mesh. The radial distribution of the plasma electron density and temperature are discussed. The variation of the plasma parameters are in good agreement with the experimental results.
Requirements for Thermochemical Data in the Lighting Community
Authors: Davies R. Hugh , Dinsdale Alan T. , Markus Torsten , Mucklejohn Stuart A. , Zissis Georges
Published: February 2015

The need for thermochemical data in the lighting industry is reviewed; these data are required not only in the research and development phase but also throughout the product life cycle. This review has lead to: a summary of commercially available integrated thermochemical databanks; a bibliography of thermodynamic databases available in electronic format; a list of collections of thermodynamic data that are highly valuable but not available in electronic format; a bibliography for chemical systems of specific interest to research into high intensity discharge lamps. The bibliographies will be of interest to those involved in molten salts and ionic liquids research as well as to those seeking information on alloys, oxide systems and nuclear materials. A review of the current state of ab initio calculations for the determination of thermochemical parameters is also included.
The Effect of Boronizing on the Radiation Shielding Properties of Steel
Authors: Akkurt Iskender , Calik Adnan , Akyıldırım Hakan , Mavi Betul
Published: February 2015

The radiation shielding properties of steel and its variation with the boronizing process have been investigated. For this purposes the linear attenuation coefficients of steel have been measured before and after boronizing the steel at the photon energy of 662 and 1250 keV. The measured results before boronizing were compared with the theoretical calculation. It was clearly seen that boronizing improved the radiation shielding properties of steel.
The Effect of Anionic, Cationic and Nonionic Surfactants on the Uncatalyzed Bromate Oscillator
Authors: Grančičová Ol’ga , Olexová Anna , Zacher Tomáš
Published: February 2015

The response of an uncatalyzed bromate oscillator with phenol as substrate to the increasing concentrations of cationic (CTAN), anionic (SDS) and nonionic surfactants (Brij-30 and Triton X-100) was monitored at (25±0.1) °C under stirred batch conditions. Addition of the surfactants influenced the oscillatory parameters: a slight increase of the induction period of the first series of oscillations, a significant increase of the induction period of the second series of oscillations and a gradual decrease of the oscillation numbers of both series until complete disappearance at a certain surfactant concentration. The changes in the oscillatory parameters have been ascribed to solubilization of phenol and of bromination products in the micelles, to inhibition of bromination of the aromatic substrate due to bromine solubilization, and to the catalytic effect of the charged micelle surface.
Correlation Analysis of Reactivity in the Photo- and Electro-Reduction of Cobalt(III) Complexes in Binary Organic Solvent/Water Mixtures
Authors: Sivaraj Kumarasamy , Elango Kuppanagounder P.
Published: February 2015

The photo- and electro-reduction of a series of cobalt(III) complexes of the type cis-β - [Co(trien)(RC6H4NH2)Cl]Cl2 with R = H, p-OMe, p-OEt, p-Me, p-Et, p-F, and m-Me has been studied in binary propan-2-ol/water mixtures. The redox potential (E1/2) and photo-reduction quantum yield (ΦCo(II)) data were correlated with solvent and structural parameters with the aim to shed some light on the mechanism of these reactions. The correlation of E1/2 and ΦCo(II) with macroscopic solvent parameters, viz. relative permittivity, indicated that the reactivity is influenced by both specific and non-specific solute-solvent interactions. The Kamlet-Taft solvatochromic comparison method was used to separate and quantify these effects: An increase in the percentage of organic cosolvent in the medium enhances both reduction processes, and there exists a good linear correlation between E1/2 and ΦCo(II), suggesting a similar solvation of the participants in these redox processes.
Solvent Hydrogen Bonding and Structural Effects on Nucleophilic Substitution Reactions: Part 5 – Reaction of 2-Bromo-5-nitropyridine with para-Substituted Anilines in Acetonitrile/Dimethylformamide Mixtures
Authors: Bhuvaneshwari Durvas S. , Elango Kuppanagounder P.
Published: February 2015

Substitution reactions of some para-substituted anilines with 2-bromo-5-nitropyridine are carried out conductometrically in binary acetonitrile/dimethylformamide mixtures. The second-order rate constants correlate well with Hammett’s substituent constants yielding a negative value of ρ. The multiparameter correlation with Kamlet-Taft’s solvatochromic parameters is excellent (100R2 ~ 98%), and the computed percentage contributions of these parameters (Pα = 58%, Pβ = 4%, Pπ∗ = 38%) suggest that both specific and non-specific solute-solvent-solvent interactions influence the reactivity. The solvation model proposed is well supported by the solvatochromism exhibited by the anilines in the solvent mixture under investigation. The molar extinction coefficient (εmax) of aniline varies appreciably up to ~ 25% with a change in the mole fraction of the mixture. The multivariate correlation analysis of εmax (with α, β , π∗) suggests that the solvation around the NH2 moiety of aniline through the solvent’s hydrogen-bond donor (HBD) property is found to be dominant in the solvation process and consequently in altering the rate. The dominance of the solvent’s HBD property in solvation is further confirmed by the cyclic voltammetric oxidation of aniline in the solvent mixture.
Investigations of the Spin Hamiltonian Parameters and the Local Structures of the Substitutional V4+ Centres in Rutile-Type MO2 (M = Sn, Ti, Ge)
Authors: Wu Shao-Yi , Wei Li-Hua , Zhang Zhi-Hong , Wang Xue-Feng , Lin Ji-Zi
Published: February 2015

The spin Hamiltonian parameters and the local structures of the substitutional V4+ centres in rutiletype MO2 (M = Sn, Ti and Ge) are theoretically investigated from the perturbation formulas of these parameters for a 3d1 ion in a rhombically compressed octahedron. The oxygen octahedra around V4+ are found to transform from the original elongation on the host M4+ site to compression in the impurity centres due to the Jahn-Teller effect. The calculated spin Hamiltonian parameters based on the above local structures show good agreement with the experimental data.
The Series Solution of Problems in the Calculus of Variations via the Homotopy Analysis Method
Authors: Abbasbandy Saeid , Shirzadi Ahmand
Published: February 2015

The homotopy analysis method (HAM) is used for solving the ordinary differential equations which arise from problems of the calculus of variations. Some numerical results are given to demonstrate the validity and applicability of the presented technique. The method is very effective and yields very accurate results.
Collective Effects on the Transition Bremsstrahlung Spectrum due to the Polarization Interaction in Nonideal Plasmas
Authors: Kim Hwa-Min , Jung Young-Dae
Published: February 2015

The collective effects on the transition bremsstrahlung spectrum due to the polarization interaction between the electron and Debye shielding cloud of an ion are investigated in nonideal plasmas. The impact parameter analysis with the effective pseudopotential model taking into account the nonideal collective and plasma screening effects is applied to obtain the bremsstrahlung radiation cross-section as a function of the nonideality plasma parameter, Debye length, photon energy, and projectile energy. It is shown that the collective effects enhance the bremsstrahlung radiation cross-section and decrease with increasing impact parameter. It is also shown that the collective effect is the most significant near the maximum position of the bremsstrahlung cross-section. In addition, it is shown that the collective effect decreases with an increase of the radiation photon energy
A New Isothermal Equation of State for Solids
Authors: Liu Quan
Published: February 2015

A new isothermal equation of state (EOS) for solids is derived by starting from the theory of lattice potential and using an analytical function for the volume dependence of the short-range force constant. A critical analysis of the isothermal EOSs: Murnaghan EOS, Vinet EOS, and the new EOS derived here, is presented by investigating the pressure-volume data for rare gas solids, metals and minerals. It is found that the results obtained from the new EOS are in good accordance with the corresponding values obtained from the Vinet EOS and with experimental data for all the solids up to very large compressions. On the other hand, the Murnaghan EOS is less successful at high pressure in most cases.
Solitons and Tsunamis
Authors: Constantin Adrian , Henry David
Published: February 2015

We discuss the relevance of soliton theory to the modeling of tsunami waves. Our analysis shows that for the two most devastating tsunamis of the last century, the 2004 Bay of Bengal and the 1960 Chile tsunami, the propagation distances were too short for soliton dynamics to apply. Thus the shallow water theory is appropriate for the modelling of tsunamis
The Greenhouse Effect within an Analytic Model of the Atmosphere
Authors: Dehnen Heinz
Published: February 2015

Within a simplified atmospheric model the greenhouse effect is treated by analytical methods starting from physical first principles. The influence of solar radiation, absorption cross sections of the greenhouse molecules, and cloud formation on the earth’s temperature is shown and discussed explicitly by mathematical formulae in contrast to the climate simulations. The application of our analytical results on the production of 20 ·109 t of CO2 per year yields an enlargement of the earth’s surface temperature of 2.3 · 10−2 °C per year in agreement with other estimations