bluuebunny/crossref_metadata_2025 huggingface dataset:
Exact Localized and Periodic Solutions of the Ablowitz-Ladik Discrete Nonlinear Schrödinger System
Authors: Lai Xian-jing , Zhang Jie-fang
Published: February 2015

We have studied, analytically, the Ablowitz-Ladik discrete nonlinear Schr¨odinger system. We have found a set of exact solutions which includes as particular cases periodic solutions in terms of elliptic Jacobian functions, bright and dark soliton solutions, and quasi-periodic solutions. We have also found the range of parameters where each exact solution exists. - PACS: 02.30.Jr, 05.45.Yv, 42.65.Tg, 02.30.Gp.
Entropy Production of the Willamowski-Rössler Oscillator
Authors: Stucki Jörg W. , Urbanczik Robert
Published: February 2015

Some properties of the Willamowski-Rössler model are studied by numerical simulations. From the original equations a minimal version of the model is derived which also exhibits the characteristic properties of the original model. This minimal model shows that it contains the Volterra-Lotka oscillator as a core component. It thus belongs to a class of generalized Volterra-Lotka systems. It has two steady states, a saddle point, responsible for chaos, and a fixed point, dictating its dynamic behaviour. The chaotic attractor is located close to the surface of the basin of attraction of the saddle node. The mean values of the variables are equal to the (unstable) steady state values during oscillations even under chaos, and the variables are always non-negative as in other generalized Volterra-Lotka systems. Surprisingly this was also the case with the original reversible Willamowski-Rössler model allowing to compare the entropy production during oscillations with the entropy production of the steady states. During oscillations the entropy production was always lower even under chaos. Since under these circumstances less energy is dissipated to produce the same output, the oscillating system is more efficient than the non-oscillatory one.
Ab initio Calculation of the Molecular Structure and Vibration Frequencies of Carbonate Ions Coordinated to Calcium Ions in the Zeolite CaA by Hartree-Fock Methods
Authors: Ucun Fatih , Atalay Y. , İlbasmış T.
Published: February 2015

The molecular structures and vibration frequencies of unidentate and bidentate coordinations of carbonate ions to calcium ions in the zeolite CaA have been investigated, using the Hartree-Fock method implementing 6-31 G and 6-311 G basis sets. From the calculations, for both coordinations the structures give rise to theoretical vibration frequencies corresponding well to the experimental results. Therefore the charge of the divalent calcium ion is distributed in the zeolitic structure, and not near the guest carbonate ion. Optimized structural parameters for the two coordinations have been given.
Theoretical Studies on the Gyromagnetic Factors and the Hyperfine Structure Constants for the Tetragonal Copper Center in KTaO3
Authors: Dong Hui-Ning
Published: February 2015

The gyromagnetic factors g∥, g⊥ and the hyperfine structure constants A∥ and A⊥ of the tetragonal Cu2+ center in KTaO3 are theoretically studied in this work. Based on the analyses of the electron paramagnetic resonance results of this center, it is found that the impurity Cu2+ occupies the octahedral Ta5+ site, associated with a nearest-neighbouring oxygen vacancy VO along the C4 axis. Due to the electrostatic repulsion of VO, Cu2+ is displaced away from VO by ΔZ(≈ −0.29 Å ) along the C4 axis. The theoretical values of the g and A factors based on the above defect structure and the impurity displacement agreee reasonably with the experimental data.
The Solubility of Organic Compounds in Supercritical CO2
Authors: Alvarez Guillermo A. , Baumann Wolfram , Adaime Martha Bohrer , Neitzel Frank
Published: February 2015

A simple liquid solution model is proposed to describe the effect of solvent-solute interactions on the solubility of nonpolar and slightly polar substances in supercritical solvents. Treating the system as an ideal solution, the effect of pressure on the solubility is zero or nearly zero, as it is governed by the difference in molar volume of the pure supercooled liquid solute and the pure solid solute, and this may be nearly zero. Deviations from ideal behavior are given by activity coefficients of the Margules type with the interaction parameter w interpreted as interchange energy as in the lattice theory. The hypothesis is put forward that the interchange energy is of the same form as a function proposed by Liptay and others to describe the effect of the solvent on the wavelength of the absorption maximum of the solute dissolved in the solvent. The function consists of a radius of interaction a and a function g(ε ) of the dielectric constant ε of the solvent, treated as a continuum. The function g depends on pressure through the pressure dependence of the dielectric constant ε (P). The attractive feature of this formalism, introduced by Baumann et al. and here justified thermodynamically, is that plots of the logarithm of solubility vs. g are linear, except for polar solutes near the solvent’s critical point. Changes in slope then admit interpretation as changes in the radius of interaction a with possible clues about the mechanism of solvation of these molecules.
Oxidation of Triethylamine by Ferricyanide Ions in the Presence of Sodium Hydroxide and Potassium Hydroxide
Authors: Abbas Khamis , Marji Deeb
Published: February 2015

The rate of the oxidation of triethylamine by ferricyanide ions in sodium hydroxide or potassium hydroxide solutions has been determined spectrophotometrically at 25℃. Analysis of the kinetic data indicates that the hydroxide ion does not appear in the rate law. Strong retardation of the oxidation of triethylamine, caused by the addition of ferrocyanide ions, has been observed. A plausible mechanism is suggested, and a suitable rate law, congruent with the experimental observations, has been derived.
Change of Electroweak Nuclear Reaction Rates by CP- and Isospin Symmetry Breaking – A Model Calculation
Authors: Stumpf Harald
Published: February 2015

Based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents, in previous papers the effect of CP-symmetry breaking on the effective dynamics of these particles was calculated. Motivated by the phenomenological procedure in this paper, isospin symmetry breaking will be added and the physical consequences of these calculations will be discussed. The dynamical law of the fermionic constituents is given by a relativistically invariant nonlinear spinor field equation with local interaction, canonical quantization, selfregularization and probability interpretation. The corresponding effective dynamics is derived by algebraic weak mapping theorems. In contrast to the commonly applied modifications of the quark mass matrices, CP-symmetry breaking is introduced into this algebraic formalism by an inequivalent vacuum with respect to the CP-invariant case, represented by a modified spinor field propagator. This leads to an extension of the standard model as effective theory which contains besides the “electric” electroweak bosons additional “magnetic” electroweak bosons and corresponding interactions. If furthermore the isospin invariance of the propagator is broken too, it will be demonstrated in detail that in combination with CP-symmetry breaking this induces a considerable modification of electroweak nuclear reaction rates.
On a Generating Function and its Probability Distributions. A Contribution to the Theory of Transition Rates II
Authors: Kupka Hans
Published: February 2015

A previous theory of integer-valued probability distributions is extended to many dimensions, to develop a really systematic way of treating mode mixing. The mixing of the vibrational components arises through the rotation of the normal coordinates and consequently by mixing of the parameter components in consequence of a linear relationship. The multidimensional distribution (MD), is derived with the aid of a 2N-dimensional generating function (GF), which is holomorphic in a polydisc D2N(0,1), and the expansion of which in a multiple power series leads to coefficients, which are values of a MD for several occupation number sets (n1,n2, . . . ,nN) or (m1,m2, . . . ,mN). Symmetry or invariance properties of the MD in respect to the exchange of parameters and the exchange of the occupation number sets (n1,n2, . . . ,nN) and (m1,m2, . . . ,mN) are investigated. For the special case, if the mixing matrix is a unit matrix, the multidimensional GF reduces to a product of one-dimensional GFs, each of which depends on parameters and complex variables of one separate component only. The advantages and disadvantages of this separation will be discussed. For illustrative purpose, relief plots of the MD are presented, demonstrating the effect of mode mixing
Electronic Conductivity of NaCl-KCl Equimolar Melt Containing Eu(III) and Eu(II) Complexes by Electrochemical Impedance Spectroscopy
Authors: Kuznetsov Sergey A. , Gaune-Escard Marcelle
Published: February 2015

The electronic conductivity of molten equimolar NaCl-KCl containing Eu(III) and Eu(II) complexes was studied by electrochemical impedance spectroscopy. The ratio between electronic and electrolyte resistance as a function of the electrode potential was determined. The electronic conductivity was found to be maximal when the amounts of Eu(III) and Eu(II) are about equal. The electronic conductivity of this melt does not exceed 2.3% of the ionic conductivity. Deviation from the molar ratio Eu(III)/Eu(II) = 1 led to a considerable diminution of the electronic conductivity.
The Ag I and Au I Resonance Line Broadening in Helium Plasma
Authors: Djeniže Stevan , Srećković Aleksandar , Bukvić Srdjan , Vitas Nikola
Published: February 2015

The shapes and shifts of the resonance spectral lines of neutral silver (Ag I: 328.068 and 338.289 nm) and gold (Au I: 242.795 and 267.595 nm) have been measured in a laboratory helium plasma of about 18,500 K electron temperature and an electron density ranging between 0.78 · 1023 and 1.24 · 1023 m−3. Stark broadening has been found as the dominant mechanism of the line shape and position formation. Our measured Ag I and Au I resonance line Stark widths (W) and shifts (d) are the first reliable experimental data. They are compared with calculated single Ag I and Au IW and d data based on a semiclassical approach. The measured values are higher than the calculated ones, especially of the Au I resonance lines. Besides, we have calculated the hyperfine structure (hfs) components and their relative intensities of the mentioned Ag I and Au I lines. Strong asymmetry between the red and blue components of the hfs was found. A modified version of the linear, low-pressure, pulsed arc was used as plasma source operated in helium with silver and gold atoms as impurities, evaporated from silver and gold cylindrical plates located in the homogeneous part of the discharge providing conditions free of self-absorption. At the above mentioned helium plasma conditions the splitting in the hyperfine structure (Δhfs) of the Ag I and Au I resonance lines has been overpowered by Stark and Doppler broadenings. We estimate that at electron densities below 1020 m−3 and electron temperatures below 10,000 K the hfs components in the 267.595 nm and 242.795 nm Au I lines play an important role in the line shape formation, and the resulting line profiles can be used for temperature estimation in optically thin plasmas
Exact Solutions and Solitons with Fission and Fusion Properties for the Generalized Broer-Kaup System
Authors: Zheng Chun-Long , Fang Jian-Ping
Published: February 2015

Starting from a Painlev´e-B¨acklund transformation and a linear variable separation approach, we obtain a quite general variable separation excitation to the generalized (2+1)-dimensional Broer-Kaup (GBK) system. Then based on the derived solution, we reveal soliton fission and fusion phenomena in the (2+1)-dimensional soliton system. - PACS numbers: 05.45.Yv, 03.65.Ge
Complex Pattern Formation of Simple Biochemical Amplification Reactions in Micro-Structured Flow Reactors
Authors: Ackermann Jörg , Kirner Thomas , Klapp H. L.
Published: February 2015

We have studied the dynamics of a simple amplification reaction in micro-structured flow reactors. The autocatalytic amplification reaction A+R → 2A serves as a model to describe the fundamental properties of amplification systems in an open reaction chamber. A constant inflow of resources R feeds the reaction and an outflow keeps the total mass constant. A characterization of the system in a well stirred reaction chamber is presented by discussing the steady states of the system and their bifurcation properties. In the non-stirred case, where the species diffuse freely in a spatially extended chamber, numerical solutions of a reaction-diffusion equation describe the dynamic behavior of the system. It turns out that inhibition reactions and death terms, which are unavoidable in micro-structured reaction chambers, play an essential role in the behavior of the system. The rich dynamical behavior shows three fundamental properties of non-variational nonlinear open systems: temporal order, such as limit cycle oscillation, spatially periodic order, and complex spatial-temporal pattern formation. The results are of special interest for recent experiments with evolutionary molecular ecosystems in micro-structured flow reactors.
New Types of Solitons with Fusion and Fission Properties in the (2+1)-Dimensional Generalized Broer-Kaup System
Authors: Dai Chao-Qing , Chen Jun-Lang
Published: February 2015

In this paper, by virtue of a special Painlevé-Bäcklund transformation and the linear superposition theorem, the general variable separation solution with an arbitrary number of variable separated functions of the generalized Broer-Kaup (GBK) system is obtained. Based on the general variable separation solution with some suitable variable separated functions, new types of the V-shaped soliton fusion and Y-shaped soliton fission are firstly investigated. - PACS numbers: 05.45.Yv, 02.30.Jr, 02.03Ik
Dynamics of Pulsating, Erupting, and Creeping Solitons in the Cubic- Quintic Complex Ginzburg-Landau Equation under the Modulated Field
Authors: Hong Woo-Pyo
Published: February 2015

It is shown that the dynamics of the pulsating, erupting, and creeping (PEC) solitons in the one-dimensional cubic-quintic complex Ginzburg-Landau equation can be drastically modified in the presence of a modulated field. We first perform the linear instability analysis of continuous-wave (CW) and obtain the gain by the modulational instability (MI). It is found that the CW states applied by the weakly modulated field always transform into fronts for the parameters of the PEC solitons. We then show that, when the modulated field is applied to the pulse-like initial profile, multiple solitons are formed for the parameters of the pulsating and erupting solitons. Furthermore, as the strength of the gain term increases, the multiple pulsating or erupting solitons transform into fixedshape stable solitons. This may be important for a practical use such as to generate multiple stable femtosecond pulses. For the case of creeping soliton parameters, the presence of a modulated field does not generate multiple solitons, however, the initial profile transforms into an irregularly pulsating soliton or evolves into a fixed-shape soliton as the strength of the gain term is increased. - PACS numbers: 42.65.Tg, 03.40.Kf, 05.70.Ln, 47.20.Ky
Maximum Entropy Formalism and Genetic Algorithms
Authors: Steeb Willi-Hans
Published: February 2015

We apply genetic algorithms to find solutions of the maximum entropy formalism. As an application we consider a chaotic map.
Electrochemical Study of the Interaction of Ubiquinone,0 and Ubiquinone,10 with Nucleosides and Nucleic Acid Bases
Authors: Alrufai Elham M. , El-Emara Kefah A. , Shanshal Muthana
Published: February 2015

Electrochemical polarographic measurements done for mixtures of the ubiquinone,0 (Ub,0) and Ubiquinone,10 (Ub,10) in their monomeric form (c < 10−5 mol/l) with nucleosides and nucleic acid bases show that their half wave potentials, E1/2, as well as limited diffusion currents, id, decrease as functions of the concentrations of the added components. The change in the E1/2 values is attributed to the change in the lowest unoccupied molecular orbital (LUMO) energy of the ubiquinone, resulting from its interaction with the heterocyclic rings. The decrease in id is explained in terms of complex formation and consequently increase in the mass of the reducible species, according to the Ilkovic equation. In all mixtures the number of reduction electrons (n) is smaller than that of free ubiquinone. The changes in all electrochemical variables of the native Ub,10 are more pronounced than those of the synthesized Ub,0, confirming the former accepted assumption that the complex formation ability of Ub,10 is higher than that of Ub,0. The results indicate a possible interaction of such molecules when they migrate into the mitochondria with ubiquinone molecules (coenzyme Q).
Electron Paramagnetic Resonance of Some γ-Irradiated Amino Acid Derivatives
Authors: Zincircioğlu S. Burhanedtin , Canoruç Naime , Osmanoğlu Şemsettin , Başkan M. Halim , Dicle I.Yeşim , Aydın Murat
Published: February 2015

γ -Irradiated powders of N-acetyl-L-arginine, Nα -carbamyl-L-arginine, N-glycyl-L-leucine and glycyl-L-alanine were investigated at room temperature by electron paramagnetic resonance. The observed species in N-acetyl-L-arginine and Nα -carbamyl-L-arginine were attributed to the CH2CHNHCNHNH2 radical, and those in N-glycyl-L-leucine and glycyl-L-alanine powders to (CH3)2CCH2 and CH3CHCOOH radicals.
Investigation of the Spin Hamiltonian Parameters of a Tetragonal VO2+ Center in (NH4)2SbCl5
Authors: Lin Ji-Zi , Wu Shao-Yi , Fu Qiang , Lu Guang-Duo
Published: February 2015

The spin Hamiltonian parameters g‖ and g⊥ and the hyperfine structure constants A‖ and A⊥ of a tetragonal VO2+ center in (NH4)2SbCl5 are investigated, using the perturbation formulas for a 3d1 ion in tetragonally compressed octahedra. In these formulas, the contributions to the spin Hamiltonian parameters from the s- and p-orbitals as well as the spin-orbit coupling coefficient of the Cl− ligand are taken into account, based on the cluster approach. According to these studies, compression of the ligand octahedra results from the strong axial crystal-fields due to the short V4+-O2− bond in the [VOCl4]2− cluster. The obtained spin Hamiltonian parameters agree well with the experimental data and need fewer adjustable parameters than the previous studies. The covalency of the studied system is also discussed.
Synthetic and 1H and 13C NMRSpectral Studies on N-(Mono-substitutedphenyl)- acetamides and Substituted Acetamides, 2/3/4-YC6H4NH-COCH3–iXi (Y = CH3, F, Cl, Br, NO2; X = Cl, CH3; i = 0, 1, 2, 3)
Authors: Gowda Basavalinganadoddy Thimme , Lakshmipathy Shilpa , Lakshmipathy Jayalakshmi K.
Published: February 2015

Nineteen N-(2/3/4-methyl/halo/nitro-phenyl)-acetamides and substituted acetamides, 2/3/4- YC6H4NH-CO-CH3−iXi (Y = CH3, F, Cl, Br or NO2; X = Cl or CH3 and i = 0, 1, 2 or 3), have been prepared, characterized, and their 1H and 13C NMR spectra in solution measured and correlated. 1H and 13C NMR chemical shifts were assigned to the protons and carbon atoms, respectively, in line with those for similar compounds. Since the chemical shifts are dependent on the electron density around the nucleus or associated with the atom to which it is bound, the incremental shifts of the aromatic protons or carbon atoms due to -NH-CO-CH3−iXi and -CO-CH3−iXi (X = Cl or CH3 and i = 0, 1, 2, 3) in all the N-phenyl-substituted acetamides, C6H5NH-CO-CH3−iXi, are calculated by comparing the proton or carbon chemical shifts of these compounds with those of benzene or aniline. The incremental shifts due to the groups in the parent compounds have also been computed by comparing the chemical shifts of the protons or carbon atoms in these compounds with those of benzene or aniline, respectively. The computed incremental shifts and other data were used to calculate the 1H and 13C NMR chemical shifts of the substituted compounds in three different ways. The calculated chemical shifts by the three methods compared well with each other and with the observed chemical shifts, testing the validity of the principle of additivity of the substituent effects in these compounds. The variation of 1H NMR chemical shifts of either the aromatic or N-H protons, with the substituents in N-(phenyl)- and N-(2/3/4-chloro/methylphenyl)-acetamides and substituted acetamides did not follow the same trend, while the variation of the 13C NMR chemical shifts of C-1 and C=O carbon atoms and those of alkyl carbon atoms of these compounds followed more or less the same trend.
Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2/3/4-Substituted Phenyl)-2,4-Disubstituted Benzenesulphonamides, 2,4-(CH3)2/2-CH3-4-Cl/2,4-Cl2C6H3SO2NH(i-XC6H4) (i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F, 4-Br)
Authors: Basappa Savitha M. , Gowda Basavalinganadoddy Thimme
Published: February 2015

Twenty six N-(2/3/4-substituted phenyl)-2,4-disubstituted benzenesulphonamides of the general formulae 2,4-(CH3)2C6H3SO2NH(i-XC6H4), 2-CH3-4-ClC6H3SO2NH(i-XC6H4) and 2,4- Cl2C6H3SO2NH(i-XC6H4), where i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F or 4-Br, have been prepared, characterized and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution studied. The infrared N-H stretching vibrational frequencies vary in the range 3298 - 3233 cm−1. Asymmetric and symmetric SO stretching vibrations appear in the ranges 1373 - 1311 cm−1 and 1177 - 1140 cm−1, respectively, while C-S, S-N and C-N stretching absorptions vary in the ranges 840 - 812 cm−1, 972 - 908 cm−1 and 1295 - 1209 cm−1, respectively. The various 1H and 13C NMR chemical shifts are assigned to the protons and carbon atoms of the two benzene rings in line with those for similar compounds. The incremental shifts due to the groups in the parent compounds have been computed by comparing the chemical shifts of the protons or carbon atoms in these compounds with those of benzene or aniline, respectively. The computed incremental shifts and other data were used to calculate the 1H and 13C NMR chemical shifts of the substituted compounds in three different ways. The calculated chemical shifts by the three methods compared well with each other and with the observed chemical shifts. It is observed that there are no particular trends in the variation of either the infrared absorption frequencies or the chemical shifts with the nature or site of substitution.
Higher-Order Approximations for Symmetrical Regular Long Wave Equation
Authors: Lai Xian-Jing , Zhang Jie-Fang
Published: February 2015

In this work, we extend the application of “the modified reductive perturbation method” to the symmetrical regular long wave equation and try to obtain the contribution of higher-order terms in the perturbation expansion. It is shown that the lowest-order term in the expansion is governed by the nonlinear Schrödinger equation while the second- and third-order terms are governed by the linear Schrödinger equation. By employing the hyperbolic tangent method, progressive wave type solutions are obtained for the first-, second- and third-order terms in the perturbation expansion. - PACS numbers: 02.30.Jr, 42.25.Bs, 42.81.Dp, 43.35.Kp
Eulerian and Lagrangian Structure Function’s Scaling Exponents in Turbulent Channel Flow
Authors: Luo Jian-Ping , Ushijima Tatsuo , Kitoh Osami , Lu Zhi-Ming , Liu Yu-Lu , Schmitt François G.
Published: February 2015

The relation between Eulerian structure function’s scaling exponents and Lagrangian ones in turbulent channel flows is explored both theoretically and numerically. A nonlinear parametric transformation between Eulerian structure function’s scaling exponents and Lagrangian ones is derived, following Landau and Novikov’s frame work. This relation is then compared to some known experimental and numerical results, but mainly to our DNS (direct numerical simulation) results of a fully developed channel flow with Reτ = 100. The scaling exponents are evaluated in terms of the ESS (extended self-similarity) method, since the Reynolds number is too low to make the standard scaling laws applicable. The agreement between theory and simulation is satisfactory
Inelastic Interaction and Non-Traveling-Wave Effects for Two Multi-Dimensional Burgers Models from Fluid Dynamics and Astrophysics with Symbolic Computation
Authors: Xu Tao , Zhang Chun-Yi , Li Juan , Zhang Hai-Qiang , Li Li-Li , Tian Bo
Published: February 2015

Describing the surface perturbations of a shallow viscous fluid, cosmic-ray-modified shock structures and electromagnetic waves in a saturated ferrite, the (2+1)- and (3+1)-dimensional Burgers equations are investigated in this paper. In view of the higher space dimensionality, the transformations from such two models to a (1+1)-dimensional Burgers equation are constructed with symbolic computation. Via the obtained transformations, three families of multi-dimensional N-shock-wavelike solutions are specially presented, which recover some previously published solutions. The inelastically interacting properties and some non-traveling-wave effects of shock waves are discussed through the figures for several sample solutions. Additionally, possible applications for those solutions and effects in some fields are also pointed out
Speed and Shape of Electrostatic Waves in Dust-Ion Plasma
Authors: Chatterjee Prasanta , Sen Bholanath
Published: February 2015

Nonlinear dust acoustic waves are studied in a magnetized plasma. Quasineutrality is considered. The existence of a soliton solution is determined by a pseudo-potential approach. Sagdeev’s potential is obtained in terms of U(= αudx +γudz), the component of the dust-ion velocity in the direction of the propagation of the wave. It is shown that there exists a critical value of U, beyond which the solitary waves cease to exist.
An Improved Modified Extended tanh-Function Method
Authors: Yang Zonghang , Hon Benny Y. C.
Published: February 2015

In this paper we further improve the modified extended tanh-function method to obtain new exact solutions for nonlinear partial differential equations. Numerical applications of the proposed method are verified by solving the improved Boussinesq equation and the system of variant Boussinesq equations. The new exact solutions for these equations include Jacobi elliptic doubly periodic type,Weierstrass elliptic doubly periodic type, triangular type and solitary wave solutions
On Solitary-Wave Solutions for the Coupled Korteweg – de Vries and Modified Korteweg – de Vries Equations and their Dynamics
Authors: Hong Woo-Pyo
Published: February 2015

Analytic sech4-type traveling solitary-wave solutions of the coupled Korteweg-de Vries and modified Korteweg-de Vries equations proposed by Kersten-Krasil’shchik, are found by applying the auxiliary function method. The dynamical properties of the solitary-waves are studied by numerical simulations. - PACS numbers: 03.40.Kf, 02.30.Jr, 47.20.Ky, 52.35.Mw
Extended Camassa-Holm Hierarchy and Conserved Quantities
Authors: Ivanov Rossen I.
Published: February 2015

An extension of the Camassa-Holm hierarchy is constructed in this paper. The conserved quantities of the hierarchy are studied and a recurrent formula for the integrals of motion is derived. - PACS numbers: 02.30.Ik; 05.45.Yv; 45.20.Jj; 02.30.Jr.
On the Characterization of Foam Decay with Diagram Lattices and Majorization
Authors: Sauerbrei Sonja , Sydow Uwe , Plath Peter J.
Published: February 2015

We present possibilities of comparing and characterizing bubble size distributions during foam decay. We know that the temporal development of bubble size distributions does not follow an ordinary diffusion process. Instead of an equal distribution, we obtain a multi-modal distribution at the end of the rearrangement phase. It turns out that bubble size distributions are comparable to partition diagrams generating Ruch lattices which are expandable by permutations leading to partially ordered sets. If we map the partition diagrams and the bubble size distributions on the Shannon entropy, we obtain similar functions. Furthermore, the set of partition diagrams of a Ruch lattice and the set of the bubble size distributions of foam decay are both partially ordered. Via the theorems of Muirhead and of Hardy, Littlewood and Pólya (classical majorization) we construct transitions between every partition diagram of a Ruch lattice and between every bubble size distribution. These transitions can be reversible or irreversible
Molecular Constants of the A1Σu
+ and B1Πu States of Na2
Authors: Babakay Omar , Mohamad Rami Haj , Hussein Khaled
Published: February 2015

The A1Σ+
u − X1Σ+
g and B1Πu − X1Σ+
g systems of Na2 were excited by Ar+ and Kr+ lasers ranging from 4762 to 6471 Å . High-resolution Fourier transform spectroscopy has been used to analyze the observed spectrum. The study led to the calculation of the molecular constants of the upper A1Σ+
u and B1Πu states
Phase Polymorphism of [Co(DMSO)6](BF4)2 Studied by Differential Scanning Calorimetry
Authors: Migdał-Mikuli Anna , Skoczylas Łukasz , Szostak Elżbieta
Published: February 2015

Five solid phases of [Co(DMSO)6](BF4)2 have been detected by differential scanning calorimetry (DSC). Phase transitions were detected between the following solid phases: stable KIb↔ stable KIa at T̅C4 = (328±2) K, metastable KIII ↔ undercooled phase K0 at T̅C3 = (383±4) K, metastable KII ↔ undercooled K0 at T̅C2 = (399±2) K and stable KIa ↔ stable K0 at T̅C1 = (404±1) K. The title compound melts at Tm = 440 K. From the entropy changes at the melting point and at phase transitions it can be concluded that the phases K0 and undercooled K0 are orientationally dynamically disordered crystals. The stable phases KIa, KIb are ordered solid phases. The metastable phases KII and KIII are probably solid phases with a high degree of orientational dynamical disorder
On Non-Linear Magnetohydrodynamic Flow due to Peristaltic Transport of an Oldroyd 3-Constant Fluid
Authors: Haroun Mohamed H.
Published: February 2015

In this work a theoretical analysis is presented for the problem of peristaltic transport of an incompressible Oldroyd 3-constant fluid in an infinite channel with flexible walls. The flow is induced by an infinite sinusoidal wave train moving along the walls of the channel. The fluid is electrically conducting and a magnetic field has been applied transversely to the flow. This problem has numerous applications in various branches of science. A perturbation solution of the stream function for zeroth-, first- and second-order in a small amplitude ratio is obtained. The obtained results are illustrated graphically to show salient features of the solutions. The effect of the magnetic parameter, the relaxation time and the retardation time on the mean axial velocity and the reversal flow is investigated. It is found that the possibility of flow reversal increases by increasing the magnetic parameter and viscoelastic parameters. The results show that the values of the mean axial velocity of an Oldroyd 3-constant fluid are less than these for a Newtonian fluid. Numerical results are reported for various values of the physical parameters of interest. - Mathematics Subject Classification: 76Z05
Jeans’ Gravitational Instability of a Thermally Conducting, Unbounded, Partially Ionized Plasma
Authors: Shaikh Shaista , Khan Aiyub , Bhatia Prem Kumar
Published: February 2015

The gravitational instability of an infinitely extending homogenous, partially ionized plasma, permeated by an oblique magnetic field, has been studied to investigate the effects of Hall currents, finite conductivity, viscosity, collision with neutrals and thermal conductivity on the growth rate of the disturbance. The dispersion relation obtained has been solved numerically, and it has been found that Hall currents and collision with neutrals have a destabilizing influence on the growth rate while the other mechanisms reinforce the gravitational instability. Jeans’ criterion, derived within a purely hydrodynamic framework, has been rediscussed along a nonextensive kinetic theory. A new Jeans’ criterion was deduced, which depends on the nonextensive parameter q and the standard Jeans’ wave number is recovered in the limiting case q = 1
Equivalence of Two Models for Partitioning of π-Electrons in Rings of Benzenoid Hydrocarbons
Authors: Gutman Ivan , Furtula Boris
Published: February 2015

Two recently proposed methods for assessing the π-electron contents of rings of benzenoid hydrocarbons are shown to be equivalent
Theoretical Investigations of the EPR Parameters of Ti3+ in Beryl Crystal
Authors: Zheng Wen-Chen , Zhou Qing , Wu Xiao-Xuan , Mei Yang
Published: February 2015

The EPR parameters (g factors gII, g⊥ and hyperfine structure constants AII, A⊥) of Ti3+ ion at the sixfold coordinated Al3+ site with trigonal symmetry in beryl crystal are calculated by the thirdorder perturbation formulas of 3d1 ions in a trigonal octahedron. In the calculations, the crystal-field parameters are obtained by the superposition model, and the impurity-induced local lattice relaxation (which is similar to that found for Fe3+ in beryl) is considered. The calculated EPR parameters (and also the optical spectra) are in reasonable agreement with the experimental values
The EPR Zero-Field Splitting D and its Pressure and Temperature Dependence for Trigonal Mn2+ Centers in [Zn(H2O)6](BF4)2:Mn2+ Crystal
Authors: Liu Hong-Gang , Wu Xiao-Xuan , Zheng Wen-Chen , He Lv
Published: February 2015

The EPR zero-field splitting D (= b0
2 ) and its pressure and temperature dependence for trigonal Mn2+ centers in low and room temperature phases in [Zn(H2O)6](BF4)2 :Mn2+ crystal are studied by a high-order perturbation formula based on the dominant spin-orbit coupling mechanism. From the studies, the local trigonal distortion angles, the local angular compressibilities and the local angular thermal expansion coefficients for Mn2+ centers in both phases of the [Zn(H2O)6](BF4)2 crystal are estimated. The results are discussed
Solitons with Fusion and Fission Properties in the (2+1)-Dimensional Modified Dispersive Water-Wave System
Authors: Dai Chao-Qing , Chen Rui-Pin
Published: February 2015

In this paper, by means of the general projective Riccati equation method (PREM), the variable separation solutions of the (2+1)-dimensional modified dispersive water-wave system are obtained. By further studying, we find that these variable separation solutions, which seem independent, actually depend on each other. Based on the special variable separation solution and choosing suitable functions p and q, soliton fusion and fission phenomena among peakons, compactons, dromions and semifoldons are firstly investigated. - PACS numbers: 05.45.Yv, 02.30.Jr, 02.03Ik
Non-Thermal and Dust Charge Effects on Surface Ion Waves in Semi-Bound Lorentzian Plasmas
Authors: Song Jae-Hoon , Jung Young-Dae
Published: February 2015

The non-thermal and dust charge effects on a surface electrostatic ion plasma wave are investigated in a semi-bound magnetized dusty Lorentzian plasma. The results show that the phase velocity of the surface wave with negatively charged dust grains is greater than that with positively charged dust grains or that with neutral dust grains. It is also found that the phase velocity increases with increasing the spectral index of the plasma. For the long wavelength domain, however, the phase velocity of the surface wave is found to be almost independent of the spectral index.
FT-IR Spectroscopic Study of 1,3-Diaminopropane Adsorbed on Type A, X and Y Zeolites
Authors: Öztürk Nuri , Bahçeli Semiha
Published: February 2015

The IR spectra of 1,3-diaminopropane adsorbed on NaA (type 4A), CaA (type 5A), NaX (type 13X) and NaY zeolites are reported. From the IR spectral data it can easily be stated that the characteristic NH vibration bands of aliphatic amine groups play an important role in the adsorptions of 1,3-diaminopropane on the mentioned zeolites.
On the accurate Evaluation of Overlap Integrals over Slater Type Orbitals Using Analytical and Recurrence Relations
Authors: Guseinov Israfil I. , Mamedov Bahtiyar A.
Published: February 2015

In this study, using the analytical and recurrence relations suggested by the authors in previous works, the new efficient and reliable program procedure for the overlap integrals over Slater type orbitals is presented. The proposed procedure guarantees a highly accurate evaluation of the overlap integrals with arbitrary values of quantum numbers, screening constants and internuclear distances. It is demonstrated that the computational accuracy of the proposed procedure is not only dependent on the efficiency of formulas, as has been discussed previously, but also on a number of other factors including the used program language package and solvent properties. The numerical results obtained, using the algorithm described in the present work, are in complete agreement with those obtained using the alternative evaluation procedure. We notice that the program works without any restrictions and in all ranges of integral parameters.
Some Generic Properties of Level Spacing Distributions of 2D Real Random Matrices
Authors: Grossmann Siegfried , Robnik Marko
Published: February 2015

We study the level spacing distribution P(S) of 2D real random matrices both symmetric as well as general, non-symmetric. In the general case we restrict ourselves to Gaussian distributed matrix elements, but different widths of the various matrix elements are admitted. The following results are obtained: An explicit exact formula for P(S) is derived and its behaviour close to S = 0 is studied analytically, showing that there is linear level repulsion, unless there are additional constraints for the probability distribution of the matrix elements. The constraint of having only positive or only negative but otherwise arbitrary non-diagonal elements leads to quadratic level repulsion with logarithmic corrections. These findings detail and extend our previous results already published in a preceding paper. For symmetric real 2D matrices also other, non-Gaussian statistical distributions are considered. In this case we show for arbitrary statistical distribution of the diagonal and non-diagonal elements that the level repulsion exponent ρ is always ρ = 1, provided the distribution function of the matrix elements is regular at zero value. If the distribution function of the matrix elements is a singular (but still integrable) power law near zero value of S, the level spacing distribution P(S) is a fractional exponent power law at small S. The tail of P(S) depends on further details of the matrix element statistics. We explicitly work out four cases: the uniform (box) distribution, the Cauchy-Lorentz distribution, the exponential distribution and, as an example for a singular distribution, the power law distribution for P(S) near zero value times an exponential tail.
Electrochemistry of Titanium Tetrachloride in 1-Butyl-2,3-dimethyl Imidazolium Tetrafluoroborate
Authors: Andriyko Yuriy , Fastner Ulrike , Kronberger Hermann , Nauer Gerhard E.
Published: February 2015

The electrochemistry of titanium tetrachloride has been examined in trialkyl-substituted imidazolium tetrafluoroborate at 65 °C. Ti(IV) reduction was studied with chronopotentiometry and cyclic voltammetry in melts with different concentrations of TiCl4. The diffusion coefficient of Ti(IV) ranged between 1.1·10−7 and 7·10−8 cm2 s−1. The electroreduction of Ti(IV) was found to proceed via the sequence of one-electron steps, the relative stability of the low valence intermediates being dependent on the concentration of TiCl4 in the electrolyte. The kinetics of an overlapping disproportionation reaction of Ti(II) was examined and its rate constant at low concentration (0.025 mol/l) of TiCl- was found to be k = 2 · 106 cm3 mol−1 s−1, Ti(0) being the final product of the stepwise reduction process at higher concentrations (0.03 - 0.14 mol/l).
Physicochemical Properties of Melts Used for the Electrodeposition of Niobium
Authors: Kubikova Blanka , Danek Vladimir , Gaune-Escard Marcelle
Published: February 2015

Formation of oxyfluoroniobium compounds in the binary systems KF-Nb2O5 and K2NbF7-Nb2O5 and in the ternary system KF-K2NbF7-Nb2O5 has been expected. Therefore the phase equilibrium and surface tension of the above systems have been determined. The three systems have only been investigated up to 20 mol% Nb2O5 because of its limited solubility. The obtained results have confirmed the formation of oxyfluoroniobium compounds.
Function Projective Synchronization between two Different Chaotic Systems
Authors: Chen Yong , Li Xin
Published: February 2015

A function projective synchronization is defined to synchronize two different systems up to a scaling function matrix f with different initial values. The function projective synchronization is more general than the complete synchronization, the generalized projective synchronization and the modified projective synchronization. The corresponding framework of synchronization is set up and used to achieve a function projective synchronization design of two different chaotic systems: the unified chaotic system and the Rössler system. Feasibility of the proposed control scheme is illustrated through the numerical simulation.
Influence of C-Doping on the B-11 and N-14 Quadrupole Coupling Constants in Boron-Nitride Nanotubes: A DFT Study
Authors: Mirzaei Mahmoud , Hadipour Nasser L. , Abolhassani Mohammad Reza
Published: February 2015

A computational study at the level of density functional theory (DFT) was carried out to investigate the influence of carbon doping (C-doping) on the 11B and 14N quadrupole coupling constants (CQ) in the (6,0) single-walled boron-nitride nanotube (BNNT). To this aim, a 10 Å length of BNNT consisting of 24 B atoms and 24 N atoms was selected where the end atoms are capped by hydrogen atoms. To follow the purpose, six C atoms were doped instead of three B and three N atoms as a central ring in the surface of the C-doped BNNT. The calculated CQ values for both optimized BNNT systems, raw and C-doped, reveal different electrostatic environments in the mentioned systems. It was also demonstrated that the end nuclei have the largest CQ values in both considered BNNT systems.
Phase Transitions in p-(Phenyl Benzylidene)-p1-Alkylaniline Compounds: A Dilatometric Study
Authors: Srinivasu Chintalapati , Pisipati Venkata G.K. M. , Prabhu Chadalavada R. , Murty Piratla Narayana , Lakshiminarayana Somayajula
Published: February 2015

Dilatometric studies are carried out on liquid crystals (LCs), viz., p-(phenyl benzylidene)-p1- alkylanilines (PBnA for n = 7 - 10, 12, 14 and 16). LC PBnA compounds are found to exhibit four different types of phase variants. The lower homologues (for n = 3 - 6) exhibit an NBE trivariant, intermediate homologues (with n = 7 - 9) exhibit an NABE tetravariant, higher homologues (for n = 10 - 12) exhibit an ABE tetravariant, and long higher homologues (for n = 14 and 16) exhibit an AB bivariant phase sequence. Dilatometry studies in PBnA compounds infer the first order nature for IN (for n = 7, 8 and 9), IA (for n = 10, 12, 14 and 16), NA (for n = 8 and 9) and AB (for n = 14 and 16) phase transitions. Phase transitions involving the growth of the 3D smectic-B phase in PBnAs are found to be tuned by squeezing of orientational disorder. A comparative study of phase transitions exhibited by PBnA compounds is presented along with the data in other Schiff base compounds.
1H and 13C NMR Spectral Studies on N-(j, k-Dichlorophenyl)- and N-(j, k-Dimethylphenyl)-acetamides and Substituted Acetamides
Authors: Gowda Shilpa , Gowda Basavalinganadoddy Thimme
Published: February 2015

70 N-( j,k-Dichlorophenyl / j,k-dimethylphenyl)-acetamides and substituted acetamides of the general formula j,k-X′2C6H3NH-CO-CH3−iXi ( j,k = 2,3; 2,4; 2,5; 3,4 or 3,5; X, X′ = Cl or CH3; i = 0, 1, 2 or 3) have been synthesized and their 1H and 13C NMR spectra in solution were studied. The influence of Cl and methyl substitution in the side chain as well as in the aryl group was ystematically investigated and discussed in detail. Chemical shifts of all aromatic protons and carbon atoms were computed by adding the substituent contributions in three different ways to those of the unsubstituted molecules. The agreement with the experimental values is discussed in detail for the three different methods of calculation.
Nonlinear Rolling of a Biased Ship in a Regular Beam Wave under External and Parametric Excitations
Authors: El-Bassiouny Atef F.
Published: February 2015

We consider a nonlinear oscillator simultaneously excited by external and parametric functions. The oscillator has a bias parameter that breaks the symmetry of the motion. The example that we use to illustrate the problem is the rolling oscillation of a biased ship in longitudinal waves, but many mechanical systems display similar features. The analysis took into consideration linear, quadratic, cubic, quintic, and seven terms in the polynomial expansion of the relative roll angle. The damping moment consists of the linear term associated with radiation and viscous damping and a cubic term due to frictional resistance and eddies behind bilge keels and hard bilge corners. Two methods (the averaging and the multiple time scales) are used to investigate the first-order approximate analytical solution. The modulation equations of the amplitudes and phases are obtained. These equations are used to obtain the stationary state. The stability of the proposed solution is determined applying Liapunov’s first method. Effects of different parameters on the system behaviour are investigated numerically. Results are presented graphically and discussed. The results obtained by two methods are in excellent agreement.
NMR Methods of Quantum State Detection
Authors: Furman Gregory B , Meerovich Victor M. , Sokolovsky Vladimir L.
Published: February 2015

The process of amplification of a single spin state using nuclear magnetic resonance (NMR) techniques in a rotating frame is considered. Our main aim is to investigate the efficiency of various schemes for quantum detection. Results of numerical simulation of the time dependence of individual and total nuclear polarizations for 1D, 2D, and 3D configurations of the spin systems are presented.
93Nb Nuclear Spin-Spin Relaxation in the Low-Dimensional Antiferromagnet Fe0.25NbS2
Authors: Okubo Noriaki
Published: February 2015

93Nb nuclear spin-spin relaxation has been examined in the low-dimensional antiferromagnet Fe0.25NbS2 between 4.2 K and 300 K. The relaxation is characterized by two T2’s. The temperature dependence is discussed together with the origin of the disappearance of the fast decay at low temperatures.
Electrochemical Synthesis of Mo2C Catalytical Coatings for the Water-Gas Shift Reaction
Authors: Kuznetsov Sergey A. , Dubrovskiy Anton R. , Rebrov Evgeny V. , Schouten Jaap C.
Published: February 2015

The electroreduction of CO3
2− ions on a molybdenum cathode in a NaCl-KCl-Li2CO3 melt was studied by cyclic voltammetry. The electrochemical synthesis of Mo2C on molybdenum substrates has been performed at 1123 K for 7 h with a cathodic current density of 5 mA cm−2. If molybdenum carbide is present as a thin (ca. 500 nm) film on a molybdenum substrate (Mo2C/Mo), its catalytic activity in the water gas-shift reaction is enhanced by at least an order of magnitude compared to that of the bulk Mo2C phase.
Total Cross-Sections for Electron Scattering of C3H6 Isomers: A Modified Additivity Rule Approach
Authors: Tan Xiao-Ming , Sun Jin-Feng , Shi De-Heng , Liu Zi-Jiang
Published: February 2015

A modified additivity rule approach has been presented. Total cross-sections (TCSs) for electron scattering of C3H6 isomers (C3H6 and c-C3H6) have been calculated at 10 - 300 eV employing the modified additivity rule. The approach for the TCSs of C3H6 isomeric molecules is simple, and it yields better accord with experiments in the present energy range.