bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Higher-Order Corrections on the Propagation of Nonlinear Dust-Acoustic Solitary Waves in Mesospheric Dusty Plasmas
Authors: Elwakil Sayed A. , Attia Mohamed T. , Zahran Mohsen A. , El-Shewy Emad K. , Abdelwahed Hesham G.
Published: February 2015

The contribution of the higher-order correction to nonlinear dust-acoustic waves are studied using the reductive perturbation method in an unmagnetized collisionless mesospheric dusty plasma. A Korteweg - de Vries (KdV) equation that contains the lowest-order nonlinearity and dispersion is derived from the lowest order of perturbation, and a linear inhomogeneous (KdV-type) equation that accounts for the higher-order nonlinearity and dispersion is obtained. A stationary solution is achived via renormalization method
Dynamically Screened Elastic Collisions in Nonideal Plasmas
Authors: Chang Dong-Man , Chang Won-Seok , Jung Young-Dae
Published: February 2015

The dynamic screening effects on elastic electron-ion collisions are investigated in nonideal plasmas. The second-order eikonal method with the impact parameter analysis is employed to obtain the eikonal phase as a function of the impact parameter, collision energy, thermal energy, and Debye length. The result shows that the eikonal phase decreases with increasing the thermal energy. It is also found that the dynamic screening effects on the eikonal phase are more significant for large impact parameters. The total eikonal cross section is also found to be decreased with increasing the thermal energy. It is important to note that the eikonal cross section and the eikonal phase including the dynamic screening effects are found to be greater than those including the static screening effects.
A Study of Perturbations of the A1Σu
+ State of Na2
Authors: Mohamad Rami Haj , Hussein Khaled , Babaky Omar
Published: February 2015

High resolution Fourier spectrometry techniques have been used to study the A1Σ+
u state, which is perturbed by the b3Πu state of the Na2 molecule. This study was achieved by means of exciting the B1Πu state from the X1Σ+
g ground state by 4880 Å and 4965 Å lines of an Ar+ laser. The excitation is followed by collisional transfer energy produced between B1Πu and (2)1Σ+
g states ν, which led to the population of the vibrational levels of the (2)1Σ+
g state v. The analysis of the collision-induced system (2)1Σ+
g −A1Σ+
g enabled us to study, in detail, the perturbations of 11 vibrational levels from v = 0 to v = 10 of the A1Σ+
u state.
Investigation of Phosphorus Site Condensation in CaHPO4 by Analysis of 31P MAS-NMR Tensor and X-Ray Powder Patterns
Authors: Hlel Faouzi , Kamoun Saber , Guidara Kamel
Published: February 2015

CaHPO4 was obtained by slow evaporation at room temperature. Seven samples, obtained at different annealing temperatures, were characterized by X-ray diffraction and 31P MAS-NMR spectroscopy. All NMR spectra were analyzed using a DMFIT program. At room temperature, the observed 31P NMR chemical shifts for the title compound were −1.59, −0.36 and 1.26 ppm with the relative intensities 39%, 10% and 51%, revealing the presence of three non-equivalent phosphorus sites in the structure. The investigation of the NMR tensor shift of all spectra shows that the abounding HPO2−
4 anion was progressively transformed into P2O4−
7 when the temperature increased
Direction-Correlated Correlated Photons Cannot Self-Interfere: A Prediction
Authors: Rössler Otto E. , Parisi Jürgen , Fröhlich Dieter , Toffano Zeno
Published: February 2015

A corollary to an experimental proposal made by Anton Zeilinger - the famous double-double slit experiment - is suggested to be possible. The double Mach-Zehnder experiment.
Irreversible Thermal Denaturation of β-Hemocyanin of Helix pomatia and its Substructures Studied by Differential Scanning Calorimetry
Authors: Idakieva Krassimira , Gielens Constant , Siddiqui Nurul I. , Doumanova Lyubka , Vasseva Boyka , Kostov Georgi , Shnyrov Valery L.
Published: February 2015

The thermal denaturation of β -hemocyanin from the gastropod Helix pomatia (β -HpH) at neutral pH was studied by means of differential scanning calorimetry (DSC). The denaturation was completely irreversible as judged by the absence of any endotherm on rescanning previously scanned samples. Two transitions, with apparent transition temperatures (Tm) of ca. 84 °C (main transition) and ca. 88 °C (minor transition), were detected by DSC in 20 mM MOPS buffer, containing 0.1 M NaCl, 5mM CaCl2 and 5 mM MgCl2 at pH 7.2 (buffer A), using a heating rate of 1.0 Kmin−1. Both Tm values were dependent on the scanning rate, suggesting that the thermal denaturation of β -HpH is a kinetically controlled process. The Tm and specific enthalpy values (ΔHcal) for the thermal denaturation of β -HpH were found to be independent of the protein concentration, indicating that the dissociation of the protein into monomers does not take place before the rate-determining step of the process of thermal unfolding started. A successive annealing procedure was applied to obtain the experimental deconvolution of the irreversible thermal transitions. These transitions are tentatively attributed to the denaturation of, respectively, the wall (main transition) and the collar of the β -HpH molecule. The activation energies (EA) of both transitions were found to be similar (about 500 kJ mol−1). In 130 mM glycine/NaOH buffer, pH 9.6 (buffer B), with β -HpH dissociated into subunits, the calorimetric profile had a more complex character. This could be ascribed to a different stability of the functional units (FUs) constituting the β -HpH subunit. FU d, which in the cylindrical didecameric β -HpH molecule is located in the wall, was markedly less stable than FU g, which belongs to the collar. The thermal denaturation of FUs d and g was described by the two-state irreversible model. On the basis of this model, the parameters of the Arrhenius equation were calculated.
Phase Equilibria in Copper(I) Bromide-MBr Systems (M = Li, Na, K)
Authors: Wojakowska Alina , Krzyżaka Edward , Wojakowski Andrzej , Wołcyrz Marek
Published: February 2015

The phase equilibria of CuBr-LiBr, CuBr-NaBr and CuBr-KBr were studied by difference scanning calorimetry (DSC) and X-ray powder diffraction. Extended solid solutions have been found in CuBr-LiBr, while mutual solid solubility of the components of CuBr-NaBr and CuBr-KBr seems to be negligible. It has been confirmed that K2CuBr3 is stable at room temperature.
Preparation, Characterization and Crystal Structure of the Room Temperature Phase of [(CH3)(C6H5)3P]2[ZnBr4]: A Member of the A2BX4 Family
Authors: Mostafa Mohga F. , Youssef Ahmed A. , El-Dean Thanaa S. , Mostafa Aisha M. , Farag Ibrahim S
Published: February 2015

The compound bis(methyltriphenylphosphonium) tetrabromozincate(II), [C19H18P]2[ZnBr4], Mr = 939.640, has a monoclinic unit cell, space group P21. The lattice parameters are a = 9.7693(4) Å , b = 12.5508(4) Å , c = 16.5372(6) Å , α = 90.00°, β = 105.2670(11)°, γ = 90.00°, V = 1956.11(11) Å3, Z = 2, Dx = 1.595 mgm−3 at T = 298 K. The structure consists of one distorted [ZnBr4]2− tetrahedron and two [(CH3)(C6H5)3P]+ cations. Differential scanning calorimetry indicates a continuous second-order transition at (276±2) K that may be classified as a commensurate to incommensurate transformation. A first-order transition to a higher symmetry is associated with a four-fold rotation of the [ZnBr4]2− ion and a change of entropy ΔS = 22.92 J/(K· mol) at T = (362±3) K.

Dilatometric measurements showed a decrease of the lattice parameters in the temperature range 230 - 260 K, confirmed the transition at (276±2) K, and indicated the presence of a third transition at 282 K.
Evolution Properties of the y-Periodic Solitons for the (2+1)-Dimensional Boiti-Leon-Pempinelli System
Authors: Wu Xiao-Fei , Ma Zheng-Yi , Zhu Jia-Min
Published: February 2015

With the help of the symbolic computation system Maple and an expanded projective Riccati equation approach, we obtain some new rational explicit solutions with three arbitrary functions for the (2+1)-dimensional Boiti-Leon-Pempinelli system, including Weierstrass function solutions, solitary wave solutions and trigonometric function solutions. From these, several y-periodic soliton localized excitations are constructed and some evolution properties of these novel y-periodic localized structures are discussed.
Analytic Multi-Solitonic Solutions of Variable-Coefficient Higher-Order Nonlinear Schrödinger Models by Modified Bilinear Method with Symbolic Computation
Authors: Meng Xiang-Hua , Zhang Chun-Yi , Li Juan , Xu Tao , Zhu Hong-Wu , Tian Bo
Published: February 2015

In this paper, the physically interesting variable-coefficient higher-order nonlinear Schr¨odinger models in nonlinear optical fibers with varying higher-order effects such as third-order dispersion, self-steepening, delayed nonlinear response and gain or absorption are investigated. The bilinear transformation method is modified for constructing the analytic solutions of these models directly with sets of parametric conditions. With the aid of symbolic computation, the explicit analytic multisolitonic solutions of the variable-coefficient higher-order nonlinear Schr¨odinger models are presented by employing the modified bilinear transformation method. The one- and two-solitonic solutions in explicit form are given in detail. Finally, solutions are illustrated and discussed through adjusting the parameters, so different dispersion management systems can be obtained.
Static and Dynamic Dielectric Properties of Mesogenic n-Nonyloxycyanobiphenyl (9OCB)
Authors: Czechowski Grzegorz , Jadżyn Jan
Published: February 2015

The dielectric properties of n-nonyloxycyanobiphenyl in the isotropic (I), nematic (N) and smectic A (SA) phases were investigated. The dielectric relaxation spectra, recorded in the frequency range 50 kHz - 100 MHz, were analyzed with use of the Cole-Cole equation. An anomalous temperature behavior of the static permittivity, the rotational diffusion exponent and the activation energy of mesogenic molecules rotating around their short axis, observed in the vicinity of the phase transitions, are discussed.
On Some Classes of Breather Lattice Solutions to the sinh-Gordon Equation
Authors: Fu Zuntao , Liu Shikuo
Published: February 2015

In this paper, dependent and independent variable transformations are introduced to solve the sinh- Gordon equation by using the knowledge of the elliptic equation and Jacobian elliptic functions. It is shown that different kinds of solutions can be obtained to the sinh-Gordon equation, including breather lattice solutions and periodic wave solutions.
The Planck – Kleinert Crystal
Authors: Danielewski Marek
Published: February 2015

The Planck -Kleinert Crystal hypothesis is analyzed for an ideal cubic fcc crystal formed by Planck particles. In this type of a quasi-continuum the energy, momentum, and mass transport are described by the classical balance equations. The transverse wave is the electromagnetic wave, and its velocity equals the velocity of light. The quasi-stationary collective movement of mass in the crystal is equivalent to the particle (body), and such an approach enables derivation of the Schrödinger equation. The diffusing interstitial Planck particles create a gravity field, and the computed value of G is within the accuracy of experimental data. The model predicts four different force fields and a vast amount of the “dark matter and dark energy” in the crystal lattice. It allows for a self-consistent interpretation of multiscale phenomena.
One-Dimensional Cellular Automata, Conservation Laws and Partial Differential Equations
Authors: Steeb Willi-Hans , Hardy Yorick
Published: February 2015

The existence of conservation laws (invariants) are discussed for various one-dimensional cellular automata. The cellular automata are derived from partial differential equations. Both irreversible and reversible cellular automata are investigated.
Transport Properties of LiTFSI-Acetamide Room Temperature Molten Salt Electrolytes Applied in an Li-Ion Battery
Authors: Yang Chao-Chen , Hsu Hsin-Yi , Hsu Chen-Ruei
Published: February 2015

In the present work some transport properties of the binary room temperature molten salt (RTMS) lithium bis(trifluoromethane sulfone)imide (LiTFSI)-acetamide [LiN(SO2CF3)2-CH3CONH2], applied in an Li-ion battery, have been investigated. The phase diagram was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The result reveals that the binary RTMS has an eutectic point at 201 K and the 30 mol% LiTFSI composition. The electric conductivity was measured using a direct current computerized method. The result shows that the conductivities of the melts increase with increasing temperature and acetamide content. The densities of all melts decrease with increasing temperature and acetamide content. The equivalent conductivities were fitted by the Arrhenius equation, where the activation energies were 18.15, 18.52, 20.35, 25.08 kJ/mol for 10, 20, 30, 40 mol% LiTFSI, respectively. Besides the relationships between conductivity, density composition and temperature, of the ion interaction is discussed.
A Generalized Soliton Solution of the Konopelchenko-Dubrovsky Equation using He’s Exp-Function Method
Authors: Xu Fei
Published: February 2015

In this paper, J. H. He’s exp-function method is used to obtain a generalized soliton solution with some free parameters of the Konopelchenko-Dubrovsky equation. Suitable choice of parameters in the generalized solution leads to Wazwaz’s solution [Mathematical and Computer Modelling 45, 473 (2007)]. The result shows that He’s method is very effective and convenient.
Explicit and Exact Nontravelling Wave Solutions of Konopelchenko-Dubrovsky Equations
Authors: Zhang Sheng
Published: February 2015

Based on a new first-order nonlinear ordinary differential equation with a sixth-degree nonlinear term and some of its special solutions, a generalized transformation method is proposed to obtain more general exact solutions of the (2+1)-dimensional Konopelchenko-Dubrovsky equations. As a result, new exact nontravelling wave solutions are obtained including soliton-like solutions and trigonometric function solutions, from which all travelling wave solutions obtained by B.C. Li and Y. F. Zhang [Chaos, Solitons and Fractals (2007), doi:10.1016/j.chaos.2007.01.059] can be recovered as special cases. Compared with Li and Zhang’s method and the method of D. J. Huang, D. S. Li, and H.Q. Zhang [Commun. Theor. Phys. (Beijing, China) 44, 969 (2005)], D. J. Huang and H.Q. Zhang [Rep. Math. Phys. 57, 257 (2006)], D. J. Huang, D. S. Li, and H. Q. Zhang [Chaos, Solitons and Fractals 31, 586 (2007)], the proposed method is more powerful in searching for exact solutions of nonlinear evolution equations in mathematical physics.
Dynamic Screening Effects on Collisional Orientation Phenomena in Nonideal Plasmas
Authors: Kim Hwa-Min , Jung Young-Dae
Published: February 2015

Dynamic screening effects on orientation phenomena of 1s→2p±1 excitations in nonideal plasmas are investigated. A semiclassical method is employed to describe the motion of the projectile electron in order to investigate the variation of the orientation parameter as a function of the impact parameter, projectile energy, thermal energy, and Debye length. The result shows that the preference for the 1s→2p−1 transition significantly decreases with increasing projectile energy. It is found that the dynamic screening effect increases with increasing impact parameter and also with increasing projectile energy. It is also found that the 1s → 2p−1 preference decreases with increasing thermal energy.
Compton Profile Study of Aluminium Nitride
Authors: Vyas Vimal , Sharma Yogesh Chandra , Purvia Vinod , Heda Narayan Lal , Sharma Yamini , Ahuja Babu Lal , Sharma Bal Krishna
Published: February 2015

In this paper we report the ab-initio theoretical Compton profiles of aluminium nitride (AlN) in the framework of the Hartree-Fock, density functional theory and hybridization of Hartree-Fock to density functional theories using the CRYSTAL03 code. To compare our first ever theoretical data, we have also measured the isotropic Compton profile of AlN, using 59.54 keV γ -rays. The Hartree- Fock scheme-based Compton profile agrees better with the experiment than the other theories. The energy bands, density of states and Mulliken’s population analysis, using the CRYSTAL03 code, are also reported. Our band structure calculations show a large band gap, while Mulliken’s population analysis shows the ionic nature of bonding in AlN.
AlN Nanotubes: A DFT Study of Al-27 and N-14 Electric Field Gradient Tensors
Authors: Seif Ahmad , Mirzaei Mahmoud , Aghaie Mehran , Boshra Asadollah
Published: February 2015

Density functional theory (DFT) calculations were performed to calculate the electric field gradient (EFG) tensors at the sites of aliminium (27Al) and nitrogen (14N) nuclei in an 1 nm of length (6,0) single-walled aliminium nitride nanotube (AlNNT) in three forms of the tubes, i. e. hydrogencapped, aliminium-terminated and nitrogen-terminated as representatives of zigzag AlNNTs. At first, each form was optimized at the level of the Becke3,Lee-Yang-Parr (B3LYP) method, 6-311G∗∗ basis set. After, the EFG tensors were calculated at the level of the B3LYP method, 6-311++G∗∗ and individual gauge for localized orbitals (IGLO-II and IGLO-III) types of basis sets in each of the three optimized forms and were converted to experimentally measurable nuclear quadrupole resonance (NQR) parameters, i. e. quadrupole coupling constant (qcc) and asymmetry parameter (ηQ). The evaluated NQR parameters revealed that the considered model of AlNNT can be divided into four equivalent layers with similar electrostatic properties.With the exception of Al-1, all of the three other Al layers have almost the same properties, however, N layers show significant differences in the magnitudes of the NQR parameters in the length of the nanotube. Furthermore, the evaluated NQR parameters of Al-1 in the Al-terminated form and N-1 in the N-terminated form revealed the different roles of Al (base agent) and of N (acid agent) in AlNNT. All the calculations were carried out using the GAUSSIAN 98 package program.
Hydrogen Isotope Fractionation in Aqueous Alkaline Earth Chloride Solutions
Authors: Kakiuchi Masahisa
Published: February 2015

The D/H ratio of hydrogen gas in equilibrium with aqueous alkaline earth (Mg, Ca, Sr or Ba) chloride solutions measured at 25◦C using a hydrophobic platinum catalyst, was found to be higher than the D/H ratio equilibrated with the applied pure water. The hydrogen isotope effect between such solutions and pure water changes with the molality of the solutions. The order of the D/H ratios in alkaline earth chlorides is found to be BaCl2 > SrCl2 ≥ CaCl2 ≥ MgCl2. The hydrogen isotope effect in the aqueous chloride solutions of Mg, Ca, Sr or Ba ions is significantly larger than that in the aqueous chloride solutions of Li, Na, K or Cs ions. For MgCl2 and CaCl2 solutions, the hydrogen isotope effect is opposite to the oxygen isotope effect. The results are compared with the free energy change of transfer from H2O to D2O, and are discussed for the vapour pressure ratio of H2O and D2O of CaCl2 solutions.
Electronic Absorption Spectra of Praseodymium in Molten Chlorides
Authors: Fujii Toshiyuki , Uehara Akihiro , Nagai Takayuki , Yamana Hajimu
Published: February 2015

Electronic absorption spectra of trivalent praseodymium in various alkali chloride melts were precisely measured. The oscillator strength of the hypersensitive transition, 3F2 ←3H4, showed a clear decrease with increasing temperature. This temperature dependence was the inverse of reported cases for other trivalent lanthanoides. The Judd-Ofelt parameter was analysed, and the calculated oscillator strength showed quite good agreement with the experimentally obtained oscillator strength. However, the Ω2 parameter, which is sensitive to the ligand environment change, showed a clear decrease with increasing temperature and negative values at high temperature. We found that the 3P0 ←3H4 transition and its shoulder peak are quite sensitive to the coordination circumstance change of the [PrCl6]3− complex in molten chlorides. These intensities could be correlated with the octahedral symmetry of [PrCl6]3−.
Electrochemical Synthesis of Binary Carbides of Tungsten and Iron (Nickel, Cobalt) in Halide-Oxide Melts at 823 K
Authors: Kushkhov Hasbi , Adamokova Marina , Kvashin Vitalij , Kardanov Anzor , Gramoteeva Svetlana
Published: February 2015

Iron, cobalt and nickel powders are used as binding components for the production of articles of tungsten carbide by the hot pressing method. This fact and the unique properties of binary carbides of tungsten-iron triad metals encouraged the search for new ways of their synthesis. In the present work, the attempt to synthezise binary tungsten-nickel (cobalt, iron) carbides in molten KCl-NaCl-CsCl at 823 K was made. As a result of voltammetry research, it was established that in eutectic KCl-NaCl-CsCl melts the deposition potentials ofWand Ni (Co, Fe) differ by 150 - 350 mV from each other, which makes their co-deposition difficult. It is possible to shift the deposition potentials of tungsten and metals of the iron triad metals towards each other by changing the acid-base properties of the melt. The products of electrolysis in these molten system were identified by X-ray analysis. They are mixtures of tungsten and nickel (cobalt, iron) carbides: Ni2W4C, W6C2.54; Co3W3C, Co6W6C, W2C, Co3C; FeW3C.
Localized Excitations in a Dispersive Long Water-Wave System via an Extended Projective Approach
Authors: Fei Jin-Xi , Zheng Chun-Long
Published: February 2015

By means of an extended projective approach, a new type of variable separation excitation with arbitrary functions of the (2+1)-dimensional dispersive long water-wave (DLW) system is derived. Based on the derived variable separation excitation, abundant localized coherent structures such as single-valued localized excitations, multiple-valued localized excitations and complex wave excitations are revealed by prescribing appropriate functions. - PACS numbers: 03.65.Ge, 05.45.Yv
Comments on “Best Conventional Solutions to the King’s Problem”
Authors: Kimura Gen , Tanaka Hajime , Ozawa Masanao
Published: February 2015

Conventional solutions of the (Mean) King’s problem without using entanglement have been investigated by P. K. Aravind, Z. Naturforsch. 58a, 682 (2003). We report that the upper bound for the success probability claimed is not valid in general but we give a condition for the claim to be justified.
Ab initio MO Calculations on the Structure and Raman and Infrared Spectra of [Al4O2Cl10]2– Oxide in Chloroaluminate Melts
Authors: Berg Rolf W.
Published: February 2015

The oxide complexation chemistry in molten tetrachloroaluminate salts and ionic liquids is discussed with respect to what possible structures may be formed in addition to [AlCl4]−: [Al2OCl6]2−, [Al3OCl8]−, [Al2O2Cl4]2−, [Al3O2Cl6]− and [Al4O2Cl10]2−. Ab initio molecular orbital calculations are carried out on these various aluminium chloride and oxochloride ions, in assumed isolated gaseous free ionic state, by use of the Gaussian 03W program at the restricted Hartree-Fock (HF) level and with the 6-31+G(d,p) basis set.Without any pre-assumed symmetries and with tight optimization convergence criteria and by using the modified GDIIS algorithm, the model calculations generally converge. The structures and their binding energies are presented. The expected geometries are supported, with one exception perhaps being the [Al2OCl6]2− ion, that gave a linear Al-O-Al bonding system of staggered AlCl3-groups (approximate D3d symmetry), in analogy to the linear Al-O-Al geometry of the analogous [Al2OF6]2− ion, found previously. The calculations include determination of the vibrational harmonic normal modes and the infrared and Raman spectra (vibrational band wavenumbers and intensities), without any empiric adjustments of the harmonic force constants, using constants directly predicted from the Gaussian 03W program. Previously obtained IR absorption and Raman scattering spectra of melts are assigned, by comparing to the ab initio quantum mechanical vibrational analysis results. It is concluded that the small oxide content commonly found in basic and neutral tetrachloroaluminate melts, most probably consists of [Al4O2Cl10]2− ions, and the vibrational spectra are given.
Spectroelectrochemistry and Electrochemistry of Europium Ions in Alkali Chloride Melts
Authors: Uehara Akihiro , Shirai Osamu , Nagai Takayuki , Fujii Toshiyuki , Yamana Hajimu
Published: February 2015

In order to investigate the redox equilibrium of europium ions in molten NaCl-2CsCl, UV-Vis absorption spectrophotometry measurements were performed for Eu2+ and Eu3+ in molten NaCl- 2CsCl at 923 K under simultaneous electrolytic control of their ratio. Molar absorptivities of EuCl3 and EuCl2 in NaCl-2CsCl at 923 K were determined to be (420±21) M −1cm−1 at 31200 cm−1 and (1130±56) M−1cm−1 at 30300 cm−1, respectively. The formal redox potential of the Eu2+/Eu3+ couple in NaCl-2CsCl melt at 923 K was determined to be (−0.941 ±0.004) V vs. Cl2/Cl− by electromotive force measurements on varying concentration ratios of Eu2+ and Eu3+, which were performed using a technique based on the combination of electrolysis and spectrophotometry. Cyclic voltammetry was also carried out in order to examine the characteristics of the voltammograms for the Eu2+/Eu3+ couple in NaCl-2CsCl melt. The formal redox potential of the Eu2+/Eu3+ couple determined by a spectroelectrochemical method agreed with that determined by cyclic voltammetry [(−0.946±0.008) V vs. Cl2/Cl−]. The effects of temperature on the redox potential of the Eu2+/Eu3+ couple in NaCl-2CsCl, NaCl-KCl, LiCl-KCl, and CsCl melts were studied by cyclic voltammetry in the range from 923 to 1123 K.
Phase Diagram and Electrical Conductivity of CeBr3-KBr
Authors: Rycerz Leszek , Ingier-Stocka Ewa , Gadzuric Slobodan , Gaune-Escard Marcelle
Published: February 2015

This paper continues our research program on lanthanide halide-alkali metal halide systems. Differential scanning calorimetry (DSC) was used to investigate the phase equilibria of the CeBr3-KBr system. This system is characterized by the two congruently melting compounds K3CeBr6 and K2CeBr5 and the three eutectics located at the CeBr3mole fractions 0.193 (837 K), 0.295 (855 K) and 0.555 (766 K). K3CeBr6 forms at 775 K and melts congruently at 879 K with the related enthalpies 54.5 and 41.7 kJ mol−1, respectively. K2CeBr5 melts congruently at 874 K with the enthalpy 82.4 kJ mol−1. The electrical conductivity was measured of all CeBr3-KBr mixtures and of the pure components down to temperatures below solidification. The experimental determinations were conducted over the entire composition range in steps of about 10 mol%. The specific electrical conductivity decrease with increasing CeBr3 concentration, with significantly larger conductivity changes in the potassium bromide-rich region. The results are discussed in terms of possible complex formation.
Chlorine Solutions in Molten Alkali Chlorides
Authors: Kolobov Artem , Khokhlov Vladimir , Potapov Alexei , Kochedykov Victor
Published: February 2015

Electronic absorption spectra of gaseous chlorine and their saturated solutions in molten alkali chlorides were studied in wide ranges of temperature and wavelength. It was found that gaseous chlorine has a wide absorption band between 20 000 and 43 500 cm−1. There is a tendency to both widening of the band and shifting of the absorption maximum to the short-waves region with rising temperature.

The absorption bands of saturated solutions of chlorine in all molten alkali chlorides show a maximum in the neighborhood of 30 000 cm−1. A good correlation was found between the optical density of molten salt-Cl2 systems and the solubility of chlorine.
New Solitary Wave Solutions in Higher-Order Wave Equations of the Korteweg – de Vries Type
Authors: Marinakis Vangelis
Published: February 2015

In this work we study two partial differential equations that constitute second- and third-order approximations of water wave equations of the Korteweg - de Vries type. In particular, we first study previous results concerning the derivation of solitary wave solutions of the second-order approximation. We then use a simple assumption and find new solitary wave solutions for both equations.
Modeling of the Thermodynamics of the Pseudobinary RbCl-GdCl3 System
Authors: Rutkowska Iwona , Kapała Jan
Published: February 2015

The Gibbs energies of formation of the pseudobinary compounds Rb3GdCl6(s) and RbGd2Cl7(s) from the constituent metal halides, determined by Knudsen effusion mass spectrometry, were compared with the thermodynamic properties of the solid and liquid phases of the RbCl-GdCl3 system, obtained by different methods. The compatibility of the results obtained in this work for pseudobinary compounds with literature data was assessed by an optimization procedure using the CALPHAD method. The liquid phase in the RbCl-GdCl3 system was described by the associate model. The phase diagram, thermodynamic functions of mixing of the system studied, and the Gibbs energies of formation of the pseudobinary compounds: Rb2GdCl5(s), Rb3GdCl6(s), and RbGd2Cl7(s) resulted from this optimization procedure.
Dissolution of Biopolymers Using Ionic Liquids
Authors: Mantz Robert A. , Fox Douglas M. , Green J. Marshall , Fylstra Paul A. , De Long Hugh C. , Trulove Paul C.
Published: February 2015

Ionic liquids represent a unique class of solvents that offer unprecedented versatility and tunability. Nature has developed a wide variety of materials based upon both proteins and polysaccharides. Many of these materials have unique properties that are a function not only of the material identity but are also largely dictated by processing conditions. Recent work has shown the potential of ionic liquids as solvents for the dissolution and processing of biopolymers. In this research we have expanded upon the limited data available to date using several biopolymers including: silk, chitin, collagen and elastin.
Solvent Extraction of Sr2+ and Cs+ Based on Hydrophobic Protic Ionic Liquids
Authors: Luo Huimin , Yu Miao , Dai Sheng
Published: February 2015

A series of new hydrophobic and protic alkylammonium ionic liquids with bis(trifluoromethylsulfonyl) imide or bis(perfluoroethylsulfonyl)imide as conjugated anions was synthesized in a one-pot reaction with a high yield. In essence our synthesis method involves the combination of neutralization and metathesis reactions. Some of these hydrophobic and protic ionic liquids were liquids at room temperature and therefore investigated as new extraction media for separation of Sr2+ and Cs+ from aqueous solutions. An excellent extraction efficiency was found for some of these ionic liquids using dicyclohexano-18-crown-6 and calix[4]arene-bis(tert-octylbenzo-crown-6) as extractants. The observed enhancement in the extraction efficiency can be attributed to the greater hydrophilicity of the cations of the protic ionic liquids. The application of the protic ionic liquids as new solvent systems for solvent extraction opens up a new avenue in searching for simple and efficient ionic liquids for tailored separation processes.
Roles of Cationic and Elemental Calcium in the Electro-Reduction of Solid Metal Oxides in Molten Calcium Chloride
Authors: Qiu Guohong , Jiang Kai , Ma Meng , Wang Dihua , Jin Xianbo , Chen George Z.
Published: February 2015

Previous work, mainly from this research group, is re-visited on electrochemical reduction of solid metal oxides, in the form of compacted powder, in molten CaCl2, aiming at further understanding of the roles of cationic and elemental calcium. The discussion focuses on six aspects: 1.) debate on two mechanisms proposed in the literature, i. e. electro-metallothermic reduction and electro-reduction (or electro-deoxidation), for the electrolytic removal of oxygen from solid metals or metal oxides in molten CaCl2; 2.) novel metallic cavity working electrodes for electrochemical investigations of compacted metal oxide powders in high temperature molten salts assisted by a quartz sealed Ag/AgCl reference electrode (650 ºC- 950 ºC); 3.) influence of elemental calcium on the background current observed during electrolysis of solid metal oxides in molten CaCl2; 4.) electrochemical insertion/ inclusion of cationic calcium into solid metal oxides; 5.) typical features of cyclic voltammetry and chronoamperometry (potentiostatic electrolysis) of metal oxide powders in molten CaCl2; and 6.) some kinetic considerations on the electrolytic removal of oxygen.
Structural Studies on N-(Phenyl)-2,2,2-trimethyl-acetamide, N-(2,4,6-Trimethylphenyl)-2,2,2-trimethyl-acetamide and N-(2,4,6-Trimethylphenyl)-2,2,2-trichloro-acetamide, 2,4,6-X3C6H2NH-CO-CY3 (X = H or CH3; Y = CH3 or Cl)
Authors: Gowda Basavalinganadoddy Thimme , Paulus Helmut , Svoboda Ingrid , Fuess Hartmut
Published: February 2015

To study the effect of side chain and ring substitutions on the solid state geometry of amides of the general formulae C6H5NH-CO-CX3 and 2,4,6-X3C6H2NH-CO-CH3−yXy (X = CH3 or Cl and y = 0,1,2, 3), crystal structures of N-(phenyl)-2,2,2-trimethyl-acetamide, C6- H5NH-CO-C(CH3)3 (PTMA); N-(2,4,6-trimethylphenyl)-2,2,2-trimethyl-acetamide, 2,4,6-(CH3)3- C6H2NH-CO-C(CH3)3 (TMPTMA) and N-(2,4,6-trimethylphenyl)-2,2,2-trichloro-acetamide, 2,4, 6-(CH3)3C6H2NH-CO-CCl3 (TMPTCA) have been determined. The data are analyzed along with those of N-(phenyl)-acetamide, C6H5NH-CO-CH3; N-(phenyl)-2,2,2-trichloro-acetamide, C6- H5NH-CO-CCl3; N-(2,4,6-trimethylphenyl)-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH3; N-(2,4,6- trimethylphenyl)-2-chloro-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2Cl; N-(2,4,6-trimethylphenyl)- 2,2-dichloro-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CHCl2; N-(2,4,6-trimethylphenyl)-2-methyl- acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2CH3; N-(2,4,6-trimethylphenyl)-2,2-dimethyl-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH(CH3)2; N-(2,4,6-trichlorophenyl)-acetamide, 2,4,6-Cl3C6H2- NH-CO-CH3; N-(2,4,6-trichlorophenyl)-2-chloro-acetamide, 2,4,6-Cl3C6H2NH-CO-CH2Cl; N-(2, 4,6-trichlorophenyl)-2,2-dichloro-acetamide, 2,4,6-Cl3C6H2NH-CO-CHCl2 and N-(2,4,6-trichlorophenyl)- 2,2,2-trichloro-acetamide, 2,4,6-Cl3C6H2NH-CO-CCl3. The crystallographic system, space group, formula units and lattice constants in Å are: PTMA: orthorhombic, Pca21, Z = 4, a = 9.969(3), b = 10.642(3), c = 10.172(3); TMPTMA: tetragonal, P41212, Z = 8, a = 12.708(3), b = 12.708(3), c = 17.354(4); TMPTCA: monoclinic, P21/n, Z = 8, a = 12.255(4), b = 17.904(6), c = 12.619(4), β = 95.23(2)◦. PTMA and TMPTMA have 1 molecule each in their asymmetric units, but TMPTMA shows disorder. TMPTCA has 2 molecules in its asymmetric unit. The comparison of the bond parameters reveals that there are significant changes in the structural parameters with ring and side chain substitutions.
Determination of the Limit Cycle by He’s Parameter-Expansion for Oscillators in a u3 / (1 + u2) Potential
Authors: Zhang Li-Na , Xu Lan
Published: February 2015

This paper applies He’s parameter-expansion method to determine the limit cycle of oscillators in a u
3
/(1+u
2) potential. The results are compared with the exact solutions. This shows that the method is a convenient and powerful mathematical tool for the search of limit cycles of nonlinear oscillators.
Importance of Orbital Complementarity in Spin Coupling through Two Different Bridging Groups in Dicopper(II) Complexes of Endogenous Alkoxo Bridging Ligand with Exogenous Carboxylate: Ab-initio and Semi-Empirical Calculations
Authors: Zeyrek C. Tugrul
Published: February 2015

The influence of overlap interactions between the bridging ligands and the metal d orbitals on the super-exchange coupling constant are studied by means of ab-initio restricted Hartree-Fock molecular orbital calculations. The interaction between the magnetic d orbitals and the HOMOs of the carboxylate oxygen atoms are investigated in homologous asymmetrically dibridged dicopper(II) complexes which have significantly different - 2J values (the energy separation between the spin-triplet and spin-singlet states). In order to determine the nature of the fronter orbitals, extended Hückel molecular orbital (EHMO) calculations are also reported. The differences in the magnitude of the coupling constants and magnetic behaviour are rationalized in terms of the bridging ligand orbital complementary / countercomplementary concept.
Crystal Structure Studies on Arylsulphonamides and N-Chloro-Arylsulphonamides
Authors: Gowda Basavalinganadoddy Thimme , Srilatha  , Foro Sabine , Kožíšek Jozef , Fuess Hartmut
Published: February 2015

The effect of ring substitution and N-chlorination on the molecular geometry of arylsulphonamides and N-chloro-arylsulphonamides have been studied by determining the crystal structures of 2-methyl- 4-chloro-benzenesulphonamide (2M4CBSA) and the sodium salt of N-chloro-2-methyl-4-chlorobenzenesulphonamide (NaNC2M4CBSA). The results are analyzed along with the crystal structures of benzenesulphonamide, 4-methyl-benzenesulphonamide and 4-chloro-benzenesulphonamide. The crystal structure of NaNC2M4CBSA has also been compared and correlated with the crystal structures of the above compounds and those of the sodium salts of N-chloro-benzenesulphonamide, Nchloro- 4-methyl-benzenesulphonamide, N-chloro-4-chloro-benzenesulphonamide and N-chloro-2,4- dichloro-benzenesulphonamide. The crystal system, space group, formula units and lattice constants in Å of the new structures are: 2M4CBSA: triclinic, P1, Z = 4, a = 7.9030(10), b = 8.6890(10), c = 13.272(2), α = 100.680(10)°, β = 98.500(10)°, γ = 90.050(10)°; NaNC2M4CBSA: monoclinic, C2/c, Z =4, a = 10.9690(10), b = 6.7384(6), c = 30.438(2), β = 98.442(7)°. The structure of 2M4CBSA is quite complex with four molecules in its asymmetric unit. The S-N bond length slightly decreases with substitution of electron-withdrawing groups, while the effect is more pronounced with disubstitution. The structure of NaNC2M4CBSA confirms that there is no interaction between nitrogen and sodium, and Na+ is attached to one of the sulphonyl oxygen atoms. The Na+ coordination sphere involves oxygen atoms from water moleculess of crystallization and neighbouring molecules. The S-N distance of 1.586 Å for the compound is consistent with a S-N double bond. The molecules are held together by hydrogen bonds with distances varying from 2.12 to 2.85 Å.
Unusual Influence of the Temperature on the Standard Rate Constants of Charge Transfer for the Eu(III)/Eu(II) Redox Couple in Chloride-Bromide Melts
Authors: Kuznetsov Sergey A. , Gaune-Escard Marcelle
Published: February 2015

The influence of bromide ions and temperature on the standard rate constants of the Eu(III)/Eu(II) redox reaction was determined. Cyclic voltammetry was used for the calculation of the kinetic parameters. It was shown that in NaCl-KCl (equimolar mixture)-NaBr (15 wt%)-EuCl3 melts increase of the temperature from 973 K up to 1023 K leads to a drastical decrease of the standard rate constant ks for the Eu(III)/Eu(II) redox reaction. This unusual influence of the temperature on the k
s value was explained by a change of the electron transfer mechanism. It is suggested that at 1023 K another mechanism becomes dominant - the transfer of electrons through dissolved bromine in the melt. Bromine appeared in the melt due to the decomposition of chloride-bromide or bromide complexes of Eu(III), and the concentration of bromine in the melt increased with the growth of temperature.
Magnetic Properties and Electronic Structures of Compounds from the Hf-Co Phase System
Authors: Concas Giorgio , Congiu Francesco , Belošević- Čavor Jelena , Cekić Božidar
Published: February 2015

Magnetic measurements of molar susceptibilities as a function of temperature in the temperature range between 5 and 400 K were performed for the intermetallic compounds Hf2Co and HfCo2, using a SQUID magnetometer. The density of states at the Fermi level for Hf2Co was evaluated from the measured spin paramagnetic susceptibility. In addition, band structure calculations using the augmented plane waves plus local orbitals (APW+lo) method as implemented in the WIEN2k programme package for the two compounds were done. The obtained results were compared with the measured data.
An EPR and Optical Study of VO2+ in Bis (Glycine) Cadmium Chloride Single Crystals
Authors: Selvakumar Puthiya Nayagam , Subbulakshmi Veeraghava Perumal , Subramanian Poornachari
Published: February 2015

Results of EPR and optical studies of VO2+ doped in bis (glycine) cadmium(II) chloride, belonging to a third site as a substitutional one are reported. The spin Hamiltonian parameters obtained for the site are gzz
= 1.9159, gyy
= 1.9695, gxx
= 1.9853, Azz
= 210.4 G, Ayy
= 109.8 G, and Axx
= 107.0 G. By correlating the EPR and spectral data, the molecular orbital bonding parameters have been evaluated.
On Convergence Generation in Computing the Electro-Magnetic Casimir Force
Authors: Schuller Frédéric
Published: February 2015

We tackle the very fundamental problem of zero-point energy divergence in the context of the Casimir effect. We calculate the Casimir force due to field fluctuations by using standard cavity radiation modes. The validity of convergence generation by means of an exponential energy cut-off factor is discussed in detail.
Investigation of the Local Lattice Structure and the Effects of the Orbital Reduction Factor on the g Factors of a Trigonal [Ni(H2O)6]2+ Cluster in NiTiF6 · 6H2O and ZnSiF6 · 6H2O Crystals at Different Temperatures
Authors: Li Hui-Fang , Kuang Xiao-Yu , Wang Huai-Qian , Mao Ai-Jie
Published: February 2015

The local octahedral environment of Ni2+ in NiTiF6 ・ 6H2O and ZnSiF6 ・ 6H2O crystals with a trigonal distortion has been studied at different temperatures, based on the complete energy matrices. The calculated results showed that the local lattice structure around an octahedral Ni2+ centre in NiTiF6 ・ 6H2O and ZnSiF6 ・ 6H2O exhibits a compression distortion. Simultaneously, the orbital reduction effect on the g factors has been studied. The relationship between Δg = g||−g⊥ and orbital reduction factor k at 4.2, 77 and 298 (302) K has been discussed, suggesting that there is an almost linear relation between k and Δg for the Ni2+ ion in NiTiF6 ・ 6H2O and ZnSiF6 ・ 6H2O at each temperature.
Energy Levels and g Factors of Cu2+-Doped Bis(L-asparaginato)zinc(II)
Authors: Zhang Ling , Du Maolu , Zhan Ke
Published: February 2015

The formulas for the energy levels and g factors for 3d9 ions in an orthorhombic field with D2h symmetry are obtained. They are used to investigate the energy levels and the g-anisotropy of Cu2+ ions in a bis(L-asparaginato)zinc(II) single crystal. The theoretically calculated values of the energy levels have agree well with the observed optical spectrum of the Cu2+ ions in the compound considered here, and also the calculated values of the g-anisotropy conform with the experimental values.
Hyperbolic Octonionic Proca-Maxwell Equations
Authors: Candemir Nuray , Tanışlı Murat , Özdaş Kudret , Demir Süleyman
Published: February 2015

In this study, after introducing the hyperbolic octonionic (counteroctonion) algebra, which is also expressed in the sub-algebra of sedenions, and differential operator, Proca-Maxwell equations and relevant field equations are derived in compact, simpler and elegant forms using hyperbolic octonions. This formalism demonstrates that Proca-Maxwell equations can be expressed in a single equation.
Nonlinear Wave Modulation in a Fluid-Filled Elastic Tube with Stenosis
Authors: Demiray Hilmi
Published: February 2015

In the present work, treating the arteries as a thin-walled and prestressed elastic tube with a stenosis and the blood as a Newtonian fluid with negligible viscosity, we have studied the amplitude modulation of nonlinear waves in such a composite system by use of the reductive perturbation method. The governing evolution equation was obtained as the variable coefficient nonlinear Schr¨odinger (NLS) equation. By setting the stenosis function equal to zero, we observed that this variable coefficient NLS equation reduces to the conventional NLS equation. After introducing a new dependent variable and a set of new independent coordinates, we reduced the evolution equation to the conventional NLS equation. By seeking a progressive wave type of solution to this evolution equation we observed, that the wave trajectories are not straight lines anymore; they are rather some curves in the (ξ ,τ ) plane. It was further observed that the wave speeds for both enveloping and harmonic waves are variable, and the speed of the enveloping wave increases with increasing axial distance, whereas the speed of the harmonic wave decreases with increasing axial coordinates. The numerical calculations indicated that the speed of the harmonic wave decreases with increasing time parameter, but the sensitivity of wave speed to this parameter is quite weak.
A DFT Study on the Stepwise Fluorinated Methylenecyclopropane ⇋ 1-Methylcyclopropene System
Authors: Khalil Salim M.
Published: February 2015

Density functional theory (DFT) calculations have been performed to calculate the optimized geometries of stepwise fluorinated methylenecyclopropanes and 1-methylcyclopropenes. Increasing the number of fluorine atoms caused a destabilization of methylenecycopropane. Perfluorinated 1-methylcyclopropene was found to be present in substantial concentration. This is supported by calculations of the Gibbs free energy, isodesmic reactions and orbital energies (HOMO-LUMO). These results are compared with the fluorinated cyclopropanes keto-enol system. Enthalpies, entropies and dipole moments are reported.
A Direct DFT Trajectory Study of the Bis-superoxo FAl(O2)2 Ionization
Authors: Cobos Carlos J.
Published: February 2015

Direct density functional theory (DFT) classical trajectory calculations show that after bissuperoxo FAl(O2)2 ionization, one of the side-on dioxygen units undergoes a fast intramolecular rearrangement generating a stable radical cation which presents both a peroxo and a peroxyl group bound to the central Al atom, FAl(O2)OO・+. Molecular properties of this predicted novel species have been estimated at the B3PW91/6-311+G(3df) and G3B3 levels of theory.
Bulk Modulus and Equation of State Under the Effect of Highv Temperature and High Pressure for MgO
Authors: Liu Quan
Published: February 2015

A new method for the determination of the equation of state is investigated and applied for MgO crystals. The method is developed by using the Hildebrand approximation and an analytical potential form for the overlap repulsive energy derived by Harrison from quantum mechanical considerations. The bulk modulus is also evaluated for MgO in the temperature range 300 - 200 K and down to a compression of V/V0 = 0.6 using an expression based on the Chopelas-Boehler approximation. The results obtained agree well with the ab-initio values determined by Isaak et al.
Surface Tension of KPO3-WO3 Melts
Authors: Lisnyak Vladyslav V. , Slobodyanik Mykola S , Stus Nataliya V.
Published: February 2015

The temperatures Tliq of molten xWO3-(1−x)KPO3 mixtures with a molar content between x = 0 and x=0.60 have been determined by differential thermal analysis. The surface tension of the xWO3- (1−x)KPO3 melts in the interval from x = 0 to x = 0.5 has been measured by ring tensiometry for temperatures 10 K- 20 K above the melting points, up to 1373 K. The data obtained for KPO3 were fitted by a linear dependence on the temperature and compared with data available in the literature. The surface tension of the xWO3-(1−x)KPO3 melts was found to decrease non-monotonously with x. Three bends at x ~ 0.15, 0.30, and 0.45 were observed in the surface tension vs. molar fraction curve. The first and the third bends correspond to eutectic compositions; the second one is related to the formation of congruently melting K2WO2P2O7. Equations describing the temperature and concentration dependences of the surface tension are proposed.