bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromagnetic Field with Constraints and Papapetrou Equation
Authors: Turakulov Zafar Y. , Muminov Alisher T.
Published: February 2015

It is shown that a geometric optical description of the electromagnetic wave with respect to its polarization in a curved space-time can be obtained straightforwardly from the classical variational principle for the electromagnetic field. For this purpose the entire functional space of electromagnetic fields must be reduced to its subspace of locally plane monochromatic waves. We have formulated the constraints under which this can be achieved. These constraints introduce variables of another kind which specify a field of local frames associated with the wave. They contain some congruence with null-curves. The Lagrangian for constrained electromagnetic fields contains variables of two kinds, namely a congruence of null-curves and the field itself. This in turn yields two kinds of Euler- Lagrange equations. The equations of the first kind are trivial due to the constraints imposed. The variation of the curves yields the Papapetrou equations for a classical massless particle with helicity 1
Adomian Decomposition Method for Approximating the Solution of the High-Order Dispersive Cubic-Quintic Nonlinear Schrödinger Equation
Authors: Lai Xian-Jing , Zhang Jie-Fang , Luo Jian-Fei
Published: February 2015

In this paper, the decomposition method is implemented for solving the high-order dispersive cubic-quintic nonlinear Schrödinger equation. By means of Maple the Adomian polynomials of obtained series solution have been calculated. The results reported in this article provide further evidence of the usefulness of Adomain decomposition for obtaining solutions of nonlinear problems. - PACS numbers: 02.30.Jr; 02.60.Cb; 42.65.Tg
Chaotic Solitons for the (2+1)-Dimensional Modified Dispersive Water-Wave System
Authors: Ma Song-Hua , Wu Xiao-Hong , Fang Jian-Ping , Zheng Chun-Long
Published: February 2015

With an improved mapping approach, a series of excitations of the (2+1)-dimensional modified dispersive water-wave (MDWW) system is derived. Based on the derived solitary wave excitation, we obtain some special chaotic solitons. - PACS numbers: 05.45.Yv, 03.65.Ge
Localized Coherent Structures and their Interactions for the Melnikov Equation
Authors: Peng Yan-Ze
Published: February 2015

A general functional separation solution, containing two arbitrary functions, is first obtained for the Melnikov equation by means of the singular manifold method. Some novel localized coherent structures are given by appropriately choosing these arbitrary functions, whose interaction properties are numerically studied. The creation and annihilation phenomenon of dromion structure is reported. PACS numbers: 05.45.Yv, 02.30.Ik, 02.30.Jr
Stability of Viscous Rotating Gravitating Streams in a Magnetic Field
Authors: Bhatia Prem Kumar , Mathur Ravi Prakash
Published: February 2015

We have studied the stability of two superposed viscous compressible gravitating streams rotating about an axis perpendicular to the direction of a horizontal magnetic field. For wave propagation parallel to the direction of the magnetic field the dispersion relation is derived by solving the linearized perturbation equations. Both the viscosity and rotation are found to suppress the instability of the system
First-Principles Analysis of the Rb2CrF6 Absorption Spectrum
Authors: Brik Mikhail G.
Published: February 2015

A systematic first-principles analysis of the energy level scheme and absorption spectrum of Cr4+ in Rb2CrF6 crystal is presented. The recently developed first-principles approach to the analysis of the absorption spectra of ions in crystals based on the discrete variational multi-electron (DV-ME) method was used in the calculations. The method is based on the numerical solution of the Dirac equation and has a wide area of applicability. As a result, the complete energy level scheme of Cr4+ and its absorption spectrum were calculated, assigned and compared with available experimental literature data on the ground state absorption. Numerical contributions of all possible electron configurations to the wave functions of the calculated states were determined. By analysing the molecular orbitals population, numerical contributions of the fluorine 2p- and 2s-orbitals to the 3d-molecular orbitals were determined. The significant contribution of the ligand’s wave functions shows the high degree of covalency in the considered crystal. - PACS numbers: 71.70.Ch, 71.70.Ej
Electronic Structure of Gadolinium and Dysprosium Using Compton Scattering Technique
Authors: Khera Shabha , Heda Narayan Lal , Mathur Sonal , Ahuja Babu Lal
Published: February 2015

In this paper we present the first ever measured Compton profiles of polycrystalline gadolinium and dysprosium using 661.65 keV gamma-rays. The Compton data are compared with renormalized-freeatom (RFA) and free-electron model profiles. In both cases the RFA model (with e− - e− correlation) gives a better agreement with the experiment. The hybridization effects of s-, p-, d-, and f-electrons are discussed, using the first derivatives of the Compton profiles. We also report the cohesive energy of both samples, computed from the RFA calculations. - PACS numbers: 13.60.F, 71.15.Nc, 78.70. -g, 78.70.Ck
Temperature Modulation of Double Diffusive Convection in a Horizontal Fluid Layer
Authors: Bhadauria Beer Singh
Published: February 2015

Linear stability analysis is performed for the onset of thermosolutal convection in a horizontal fluid layer with rigid-rigid boundaries. The temperature field between the walls of the fluid layer consists of two parts: a steady part and a time-dependent periodic part that oscillates with time. Only infinitesimal disturbances are considered. The effect of temperature modulation on the onset of thermosolutal convection has been studied using the Galerkin method and Floquet theory. The critical Rayleigh number is calculated as a function of frequency and amplitude of modulation, Prandtl number, diffusivity ratio and solute Rayleigh number. Stabilizing and destabilizing effects of modulation on the onset of double diffusive convection have been obtained. The effects of the diffusivity ratio and solute Rayleigh number on the stability of the system are also discussed.
The Covalence Effect of the Electron States of ZnSe:Co2+
Authors: Chen Jia-Jun , Du Mao-Lu , Zheng Ti-Xian
Published: February 2015

In the investigation of the optical and magnetic properties of 3dN ion impurities in semiconductors, the contribution of the covalence must be considered. A modified d function (d∗) and two covalent factors associated with the t2 and e orbitals have been adopted for describing this covalence. We present the contribution of the covalent factors to the energy matrix of the d∗7 electron and d∗3 hole system. This suggests that the dN electron system cannot be explained with the d10−N hole system when the covalence is considered. The calculation of the energy levels by the d∗7 energy matrix agrees with the experimental finding of ZnSe:Co2+. - PACS numbers: 71.70.Ch, 71.55.Gs
The Local Structure Distortion of Chromium-Phosphorus Clusters as Cr2+ Impurity in InP Semiconductors
Authors: Tan Xiao-Ming , Kuang Xiao-Yu , Zhou Kang-Wei , Lu Cheng , Zhu Qin-Sheng
Published: February 2015

By diagonalizing the complete energy matrix of a d4 configuration ion in tetragonal symmetry, the zero-field-splitting parameters a, D and F of InP:Cr2+ have been studied. The local structure distortion parameters ΔR = 0.08 Å and Δθ = 1.01◦ were estimated. They show an expansion distortion around Cr2+ in the InP semiconductor. The Jahn-Teller energy EJT is found to be about 413 cm−1, which agrees well with the experiment. - PACS numbers: 75.10.Dg; 76.30.-v
The C–H···O Hydrogen Bonding Effects on the 17O Electric Field Gradient and Chemical Shielding Tensors in Crystalline 1-Methyluracil: A DFT Study
Authors: Partovi Tayyebeh , Mirzaei Mahmoud , Hadipour Nasser L.
Published: February 2015

A density functional study was carried out to investigate the C-H···O hydrogen bonding effects on the 17O electric field gradient and chemical shielding tensors in crystalline 1-methyluracil. Since the structural coordinates were obtained from a neutron diffraction study, no geometry optimization was needed in performing the calculations. It is demonstrated that C-H···O hydrogen bonding has different influences on O2 and O4 EFG and CS tensors. In the tetramer model of 1-methyluracil, which is much closer to the real crystalline phase, the influence of C-H···O on the O4 EFG and CS tensors is significant, whereas this influence is negligible for O2.
A Conceptual Review of Nanosensors
Authors: Lim Teik-Cheng , Ramakrishna Seeram
Published: February 2015

Nanosensors are gaining increasing attention due to the need to detect and measure chemical and physical properties in difficult to reach biological and industrial systems that are in the nano-scale region. This conceptual review surveys various nanosensors, which are categorized into three broad types: optical, electromagnetic and mechanical nanosensors. The sensing concepts and their corresponding advantages are discussed with reference to their applications.
Electron Paramagnetic Resonance of Organic and Inorganic Centers in γ-Irradiated Natural Sepiolite Minerals
Authors: Köseoğlua Rahmi , Köksalb Fevzi , Akkurt Mehmet , Çiftçi Emin
Published: February 2015

Natural sepiolite minerals and their γ -irradiated forms were investigated by electron paramagnetic resonance (EPR) at room temperature and at 113 K. The EPR signals in powders of natural sepiolite were observed due to clusters of Fe3+ ions. The paramagnetic centers produced by γ - irradiation of natural sepiolite minerals were attributed to the ĊH3 at room temperature and ṠO−
2 and ṠO−
3 radicals at 113 K. These centers were found to be perfectly observable above 20 mW microwave power. The g values of all paramagnetic centers have been measured and the A values of some of them have been reported. The results were consistent with the literature data for similar paramagnetic centers.
Impedance Spectroscopy on Polymer-Fullerene Solar Cells
Authors: Knipper Martin , Parisi Jürgen , Coakley Kevin , Waldauf Christoph , Brabec Christoph J. , Dyakonov Vladimir
Published: February 2015

Impedance spectroscopy is used for studying the electrical transport properties of bulk heterojunction solar cells. A replacement circuit is needed to translate the frequency response of the circuit to the individual interfaces and layers of the solar cell. As a material combination and device architecture, composites of P3HT and PCBM, sandwiched between a transparent ITO front electrode and an aluminum back electrode, as well as a polymer buffer layer were investigated. By varying the film thickness we identified an equivalent circuit capable to fit our experimental data. We found a dielectric constant for the P3HT and for the P3HT:PCBM bulk.
Alkanes with Greatest Estrada Index
Authors: Gutman Ivan , Furtula Boris , Marković Violeta , Glišić Biljana
Published: February 2015

If λ1 >λ2 ≥λ3 ≥ · · · ≥λn are the eigenvalues of the molecular graph, then the Estrada index, a recently conceived molecular structure-descriptor is EE = nΣ i=1eλi . The same alkanes, whose molecular graphs have extremal Wiener indices and λ1, are shown to be also extremal with regard to the Estrada index.
Electrochemical Synthesis of Binary and Ternary Refractory Compounds in the System Ti-Si-B from Chloride-Fluoride Melts
Authors: Devyatkin Sergei V.
Published: February 2015

Electrochemical synthesis of binary and ternary compounds in the system Ti-Si-B from chloridefluoride melts has been investigated by voltammetry and electrolysis. Electrochemical syntheses of titanium diboride, four titanium silicides (TiSi2, TiSi, Ti5Si4, Ti5Si3), silicon tetraboride and a new ternary compound, Ti5Si3B3, have been found to be one-step processes. The stoichiometry of the deposited compounds has been found to correlate with the bulk concentration of Ti, Si and B ions in the melt.
Mechanical Properties of Boronized Fe-0.94%Mn Binary Alloy
Authors: Calik Adnan , Sahin Osman , Ekinci Ali Ercan , Ucar Nazim
Published: February 2015

Fe-0.94%Mn alloys were boronized at 1210 K during 4 h by the powder pack method. Three distinct regions of cross-sections were found in such alloys. The boride layers were characterized by means of microscopy in terms of coating morphology and thickness. The hardness and thickness of the boride layers were measured, and it was observed that they depend strongly on the thermal processes performed before boronizing the alloys.
The Fission, Fusion and Annihilation of Solitons of the (2+1)-Dimensional Broer-Kaup-Kupershmidt System
Authors: Ma Song-Hua , Fang Jian-Ping , Zheng Chun-Long
Published: February 2015

By means of an improved mapping approach, a series of excitations of the (2+1)-dimensional Broer-Kaup-Kupershmidt (BKK) system is derived. Based on the derived solitary wave excitation, some specific fission, fusion and annihilation phenomena of solitons are also obtained. - PACS numbers: 05.45.Yv, 03.65.Ge.
Interactions of Nonlinear Waves in Fluid-Filled Elastic Tubes
Authors: Demiray Hilmi
Published: February 2015

In this work, treating an artery as a prestressed thin-walled elastic tube and the blood as an inviscid fluid, the interactions of two nonlinear waves propagating in opposite directions are studied in the longwave approximation by use of the extended PLK (Poincaré-Lighthill-Kuo) perturbation method. The results show that up to O(k3), where k is the wave number, the head-on collision of two solitary waves is elastic and the solitary waves preserve their original properties after the interaction. The leading-order analytical phase shifts and the trajectories of two solitons after the collision are derived explicitly.
Exact Green’S Function for 2D Dirac Oscillator in Constant Magnetic Field
Authors: Haouat Salah , Chetouani Lyazid
Published: February 2015

The propagator of two-dimensional Dirac oscillator in the presence of a constant magnetic field is presented by means of path integrals, where the spin degree-of-freedom is described by odd Grassmannian variables and the gauge invariant part of the effective action has the form of the standard pseudoclassical action given by Berezin and Marinov. Then the path integration is carried out and the problem is solved exactly. The energy spectrum of the electron and the wave functions are extracted. - PACS numbers: 03.65.Ca, 03.65.Db, 03.65.Pm, 03.65.Ge.
Phase Polymorphism of [Ni(DMSO)6](ClO4)2 Studied by Differential Scanning Calorimetry
Authors: Migdał-Mikuli Anna , Szostak Elżbieta
Published: February 2015

Six solid phases of [Ni(DMSO)6](ClO4)2 have been detected by differential scanning calorimetry (DSC). The five phase transitions were detected between the following solid phases: metastable KIII ↔ undercooled K0 at TC5 = 326 K, stable KIb → stable KIa at TC4 = 350 K, metastable KII ↔ undercooled KI at TC3 = 353 K, stable KIa → stable KI at TC2 = 365 K and stable KI → stable K0 at TC1 = 380 K. At Tm2 = 459 K the title compound partially dissolves in DMSO, which arises from the decomposition of [Ni(DMSO)6](ClO4)2 to [Ni(DMSO)5](ClO4)2, and at Tm1 = 526 K created in this way a substance which completely melts. 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 KI, KIa, KIb and the metastable phases KII and KIII are more or less ordered solids.
Effect of Meta-Substitution on Solid State Geometry of N-(Aryl)-2,2,2-trichloro-acetamides, 3-XC6H4NH-CO-CCl3 and 3,5-X2C6H3NH-CO-CCl3 (X = Cl, CH3)
Authors: Gowda Basavalinganadoddy Thimme , Kožíšek Jozef , Svoboda Ingrid , Fuess Hartmut
Published: February 2015

The crystal structures of N-(meta-substituted phenyl)-2,2,2-trichloro-acetamides such as N- (3-methylphenyl)-2,2,2-trichloro-acetamide, 3-CH3C6H4NH-CO-CCl3 (3MPTCA); N-(3-chlorophenyl)- 2,2,2-trichloro-acetamide, 3-ClC6H4NH-CO-CCl3 (3CPTCA); N-(3,5-dimethylphenyl)- 2,2,2-trichloro-acetamide, 3,5-(CH3)2C6H3NH-CO-CCl3 (35DMPTCA) and N-(3,5-dichlorophenyl)- 2,2,2-trichloro-acetamide, 3,5-Cl2C6H3NH-CO-CCl3 (35DCPTCA) have been determined at room temperature. The crystal system, space group, formula units and lattice constants (Å ) of the new structures are: 3MPTCA: orthorhombic, Pbca, Z = 8, a = 12.3199(11), b = 8.9719(8), c = 20.2058(15); 3CPTCA: orthorhombic, Fdd2, Z =16, a=19.285(4), b=40.765(8), c=5.5920(11); 35DMPTCA: triclinic, P1̄, Z = 2, a = 8.994(4), b = 9.9890(10), c = 14.760(5), α = 79.56(2)°, β = 73.32(3)°, γ = 86.47(2)°; and 35DCPTCA: orthorhombic, Pbca, Z = 8, a = 22.485(5), b=10.738(2), c=10.028(3). The compound 35DMPTCA has two molecules in its asymmetric unit, similar to o-NO2-, m-NO2- and p-CH3-substituted phenyl-trichloro-acetamides, while 3MPTCA, 3CPTCA and 35DCPTCA have one molecule each in their asymmetric units. The analysis of data indicates that the substitution of a strong electron withdrawing group such as a nitro group into PTCA at ortho or meta positions has a significant effect on the crystal parameters.
EPR Theoretical Study of the Local Lattice Structure of Fe3+ Doped in MgTiO3 and LiTaO3
Authors: Pan Lei-Lei , Kuang Xiao-Yu , Li Guang-Dong , Wang Hui
Published: February 2015

The EPR zero-field splittings of Fe3+ doped in MgTiO3 and LiTaO3 are studied by diagonalizing the complete energy matrices of the electron-electron repulsion, ligand-field and spin-orbit coupling interactions for a d5 configuration ion in a trigonal ligand-field. It is shown that, when Fe3+ is doped in aMgTiO3 or LiTaO3 crystal, the local lattice structure around the octahedral Fe3+ center has an obvious distortion along the C3 axis. By simulating the second- and fourth-order EPR parameters D and (a−F) simultaneously, the local structure parameters of Fe3+ doped inMgTiO3 and LiTaO3 crystals are determined, which reveal that Fe3+ occupies both the Mg2+ and Ti4+ sites in the MgTiO3:Fe3+ system and occupies the Li+ site rather than the Ta5+ site in the LiTaO3:Fe3+ system. The results accord with the ENDOR and EPR experiments. - PACS numbers: 71.70.Gm; 75.30.Et; 71.70.Ch.
Controlling Engine System: a Low-Dimensional Dynamics in a Spark Ignition Engine of a Motorcycle
Authors: Matsumoto Kazuhiro , Tsuda Ichiro , Hosoi Yuki
Published: February 2015

We analyze a time series of the combustion pressure in the idle state, measured from a spark ignition engine of a motorcycle. It is clarified that the engine system can be described by a lowdimensional deterministic dynamics perturbed by some stochastic process.We also propose a method to stabilize the chaotic behaviour of engine’s data by adopting the Pyragas’ method. We actually use this method in a computer experiment for the control of combustion pressure data to demonstrate the efficiency of the proposed method. As a result of the experiment, we eliminate the fluctuations in the combustion pressure data and obtain a periodic orbit.
Adhesion Energy, Surface Traction and Surface Tension in Fe-Mg Binary Alloys
Authors: Adebayo Gboyega A. , Anusionwu Bede C.
Published: February 2015

We present adhesion and surface energies of Fe-Mg binary alloys from simulation studies. The adhesion energy was calculated using the assumption that work is done when atoms come into contact by moving two surfaces from equilibrium position zo to ∞, while the surface traction was determined from the atomic interactions between atoms. The surface tension variation with temperature was investigated from the diffusion coefficient obtained by performing molecular dynamics simulations at temperatures above the eutetic temperature of Fe-Mg. It was observed that the structural information as well as the calculated surface tension suggest segregation in Fe-Mg alloys at all investigated temperatures.
Amplification of a Laser Beam for the Fast Ignition of a Thermonuclear Target
Authors: Winterberg Friedwardt
Published: February 2015

It is proposed to simultaneously compress a thermonuclear target and amplify a laser beam by a single z-pinch discharge. The laser beam is imploded and amplified by a cylindrical convergent shock wave inside a capillary, transforming it into a soft X-ray pulse for the fast ignition of the thermonuclear target. The target is compressed inside a liner by the z-pinch current. The capillary is attached to one end of the cylindrical target, and is protected by a radial wire spoke array fast opening switch against its premature implosion by the convergent shock wave. The z-pinch can be stabilized by placing it into a powerful vortex.
The Diffusivity-Mobility Relationship of Heavily Doped Semiconductors Exhibiting a Non-Parabolic Band Structure and Bandgap Narrowing
Authors: Das Atanu , Khan Arif
Published: February 2015

A relationship between the mobility and diffusivity of semiconductors exhibiting bandgap narrowing has been presented. The relationship is general and applicable to both non-degenerate and degenerate semiconductors under an applied bias. It is suitable for the investigation of the electrical transport in heavily doped semiconductors.
Influence of Thermal Annealing on the Electrical Properties of Poly(3-hexylthiophene)-Based Thin Film Diodes
Authors: Chiguvare Zivayi , Parisi Jürgen , Dyakonov Vladimir
Published: February 2015

The effects of thermal annealing on the bulk transport properties of poly(3-hexylthiophene) (P3HT) were studied by analyzing room temperature current-voltage characteristics of polymer thin films sandwiched between indium tin oxide/poly[ethylene dioxythiophene]:poly[styrene sulfonate] (ITO/PEDOT:PSS) and aluminum electrodes, before and after a thermal annealing step. It was observed that annealing takes place in two steps: (1) Dedoping of the polymer of impurities such as oxygen, remnant solvent, water, leading to a decrease in the conductivity of the film, and (2) thermally induced motion of the polymer chains leading to closer packing, thus, stronger inter-chain interaction and, consequently, increase in conductivity. It was also observed that the ITO/PEDOT:PSS/P3HT hole injection barrier increases on annealing the ITO/PEDOT:PSS/P3HT/Al thin film devices. The implications of impurity dedoping and closer packing on the output characteristics of bulk heterojunction polymer-fullerene thin film solar cells are discussed.
Ionic Dynamics in the Ionic Plastic Crystal NH4NO2
Authors: Honda Hisashi
Published: February 2015

Using 1H NMR T1 and T1ρ measurements self-diffusion of NH4 + with an activation energy of (80 ± 10) kJ mol−1 was detected in the highest-temperature phase of NH4NO2 crystals. Narrow 15N NMR spectra of 15NH4NO2 and NH4
15NO2 revealed that the isotropic reorientation rates of NH4 + and NO2 − ions are rapid in the high-temperature solid phase. These results suggest that the high-temperature phase of NH4NO2 crystals forms an ionic plastic phase.
The Electrochemical Reduction of Chromium Sesquioxide in Molten Calcium Chloride under Cathodic Potential Control
Authors: Schwandt Carsten , Fray Derek J.
Published: February 2015

Electrochemical polarization and reduction experiments are reported which were performed with a three-terminal cell and a molten salt electrolyte consisting of calcium chloride with additions of calcium oxide. Employing a metal cathode, a graphite anode and a pseudo-reference electrode also made from graphite, polarization measurements were carried out with the aim to validate the performance of the pseudo-reference electrode and to assess the stability of the electrolyte. Using a chromium sesquioxide cathode in conjunction with a graphite anode and a graphite pseudo-reference electrode, electrochemical reduction experiments were conducted under potentiostatic control. The key results are: a graphite pseudo-reference electrode has been shown to be appropriate in the present type of molten salt electrochemical experiments that take place on a time scale of many hours; the conversion of chromium oxide into chromium metal has been accomplished under cathodic potential control and in the absence of calcium metal deposition; a significant amount of calcium oxide in the calcium chloride has been found necessary to preclude anodic chlorine formation throughout the entire experiment; a considerable overpotential has been identified at the anode.
Effect of Melt Composition on the Reaction of Uranium Dioxide with Hydrogen Chloride in Molten Alkali Chlorides
Authors: Volkovich Vladimir A. , Polovov Ilya B. , Vasin Boris D. , Griffiths Trevor R. , Sharrad Clint A. , May Iain , Charnock John M.
Published: February 2015

The reaction of uranium dioxide with excess hydrogen chloride in alkali chloride melts (LiCl, 3LiCl-2KCl, NaCl-KCl and NaCl-2CsCl) has been studied between 450 and 750◦C, and the reaction products were characterized by electronic absorption and X-ray absorption spectroscopy. Uranium( V), [UO2Cl4]3−, and uranium(IV), [UCl6]2−, species were formed. They depended upon the temperature and the radius of the alkali cations present. Uranium(V) ions predominated in melts with small cations (LiCl and 3LiCl-2KCl).
New Variable Separation Solutions of the (2+1)-Dimensional Generalized Broer-Kaup System
Authors: Chen Jun-Lang , Dai Chao-Qing
Published: February 2015

Using symbolic and algebra computation, the extended tanh-function method (ETM) based on the mapping method is further extended. New variable separation solutions of the (2+1)-dimensional generalized Broer-Kaup (GBK) system are derived. From the periodic wave solution and by selecting appropriate functions, the evolutional behaviours of dromions in the background of Jacobian elliptic wave and their interaction behaviours are investigated.
Electrodeposition of Zinc from Binary ZnCl2-DMSO2 Molten Electrolyte at Room Temperature
Authors: Yang Chao-Chen , Shu Min-Fong
Published: February 2015

The electrochemical behaviour of zinc on copper, platinum, and tungsten working electrodes was investigated in a binary ZnCl2-DMSO2 room temperature molten salt electrolyte in the temperature range of 60 - 80◦C. Various over-potentials, −0.1, −0.2, −0.3, −0.4, and −0.5 V, were chosen as deposition potentials. The nucleation/growth of zinc changed from progressive to instantaneous if the over-potentials increased from low to high level. The surface morphology and crystal structure of the deposited layer were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Moreover, larger grain size and hexagonal close packing of the zinc layer at −0.5 V were observed by transmission electron microscopy (TEM) with electron diffraction mapping.
Quantum Multi-Signature Protocol Based on Teleportation
Authors: Wen Xiao-Jun , Liu Yun , Sun Yu
Published: February 2015

In this paper, a protocol which can be used in multi-user quantum signature is proposed. The scheme of signature and verification is based on the correlation of Greenberger-Horne-Zeilinger (GHZ) states and the controlled quantum teleportation. Different from the digital signatures, which are based on computational complexity, the proposed protocol has perfect security in the noiseless quantum channels. Compared to previous quantum signature schemes, this protocol can verify the signature independent of an arbitrator as well as realize multi-user signature together. - PACS numbers: 03.67.Dd; 03.67.-a
Rotational Energy Transfer within the A1Σu
+ State of Na2 Induced by Collisions with (2S1/2) Na
Authors: Mohamad Rami Haj , Hussein Khaled , Nachabé Abdel-Monhem
Published: February 2015

The (v’ = 34, J’ = 14) level of the A1Σ+
u electronic state of Na2 has been selectively populated by excitation with the 578.1 nm line of a ring dye-laser with rhodamine 6G. Through collisions with (2S1/2) Na atoms, energy is transferred to neighbouring rotational levels in Na2, and the density of these levels is determined by observing the fluorescence to the electronic ground state. From previous measurements of the lifetime of the A1Σ+
u state and new measurements of the intensities of collision-induced spectral lines, absolute collision cross-sections for all rotational transitions up to ΔJ = ±6 have been obtained; the total cross-section for all rotational transitions observed is: rotσtotal = 0.41 nm2.
Differential Capacity of the Double-Layer Formed at a Solid Electrode (Pt, Au)/Ionic Liquid Interface
Authors: Lewandowski Andrzej , Galiński Maciej , Krajewski Sebastian R.
Published: February 2015

The differential capacity at the electrode (Pt, Au)/ionic liquid interface of 18 ionic liquids (ILs), was measured applying chronoamperometry. The measurements were done by a two electrode system. The double layer capacity at the Pt/IL and Au/IL interface was 1 - 8 μF/cm2. The capacity, estimated from the impedance measurements, was approximately constant within a potential range of ca. 3 V.
Dielectric Relaxation Studies of Mixtures of N-Methylacetamide and Ethanol in Benzene Solutions Using Microwave Absorption Technique
Authors: Kumar Raman , Rangra Vir Singh , Sharma Dhani Ram , Thakur Nagesh , Negi Nainjeet Singh
Published: February 2015

Using standard standing wave microwave X-band techniques, and by following Gopala Krishna’s single frequency (9.90 GHz) concentration variational method, the dielectric relaxation times (τ) and dipole moments (μ) of binary mixtures of different molar concentrations of ethanol (EtOH) in binary mixtures of N-methylacetamide (NMA) and ethanol in benzene solutions at 25, 30, 35 and 40 ◦C have been calculated. The activation parameters (ΔHε , ΔFε , ΔSε ) for the dielectric relaxation process of binary mixtures containing 30 mol% of EtOH have been calculated at 25, 30, 35 and 40 ◦C and compared with the corresponding viscosity parameters. A good agreement between the free energy of activation from these two sets of values shows that the dielectric relaxation process, like the viscous flow, can be treated as a rate process. From relaxation time behaviour of NMA and EtOH binary mixtures in benzene solution, solute-solute and solute-solvent types of the molecular association have been predicted.
Studies of the EPR g-Shift of [Cr(CN)6]3– Clusters due to Crystal-Field and Charge-Transfer Mechanisms
Authors: Wu Xiao-Xuan , Feng Wen-Ling , Fang Wang , Zheng Wen-Chen
Published: February 2015

The EPR g-shift Δg (≈ g−ge) of the metal-cyanide cluster [Cr(CN)6]3− is calculated by high-order perturbation formulas based on both the crystal-field (CF) and charge-transfer (CT) mechanisms (the latter is often neglected in the crystal-field theory). The result agrees with the experimental value. The sign of the g-shift ΔgCT due to the contribution of the CT mechanism is opposite to that of ΔgCF due to the contribution of the CF mechanism, and the absolute value of ΔgCT is about 34% of that of ΔgCF. It appears that for transition metal ions in a strong covalent cluster, a reasonable theoretical explanation of the g-shift should take both the CF and CT mechanism into account.
Scattering Characteristics of Stratified Double Negative Stacks Using the Frequency Dispersive Cold Plasma Medium
Authors: Sabah Cumali , Uckun Savas
Published: February 2015

We present the wave propagation through stratified double negative stacks to illustrate the scattering characteristics of their structure. The double negative stacks are modeled by using the hypothetical non-dispersive and the frequency dispersive cold plasma media. The stacks are embedded between two double positive media and the incident electric field is assumed a plane electromagnetic wave with any arbitrary polarization. By imposing the boundary conditions, the relations between the fields inside and outside the stacks can be written in a matrix form. Using this transfer matrix, the incident, reflected, and transmitted powers are derived. The variations of the powers for the stratified double negative stacks using the frequency dispersive cold plasma medium have not been investigated yet, in detail. Thus, their characteristics for the perpendicular polarization is computed and presented in numerical results with the emphasis on the plasma frequencies. It is seen from the numerical results that the stratified double negative stacks can be used as electromagnetic filters at some frequency bands.
Influence of Sulphur Impurities on the Interfacial Tension between Aluminium and Cryolite Alumina Melts
Authors: Korenko Michal
Published: February 2015

The interfacial tension (IFT) between aluminium and cryolite melts containing different salt additions (AlF3, NaF,Na2SO4) has been measured during electrolysis by the capillary depression method. The technique is based on the measurement of the capillary depression occurring when a capillary, which is moved vertically down through the molten salt layer, passes through the metal/salt interface. The depression is measured by simultaneous video recording of the immersion height of the alumina capillary. The interfacial tension is strongly dependent on the n(NaF)/n(AlF3) ratio. The addition of Na2SO4 decreases the IFT of the aluminium/electrolyte interface. We also found the different influence of the conditions of electrolysis on the IFT in systems with and without Na2SO4. In systems without Na2SO4 the IFT decreases with increasing current density, and in systems with Na2SO4 it increases.
Vibration Energy Accumulation and Redistribution in Organic Molecules Irradiated by Infrared Photons
Authors: Jungclas Hartmut , Popova Anna M. , Komarov Viacheslav V. , Schmidt Lothar , Zulauf Alexander
Published: February 2015

A theoretical approach to the dissociation and low-energy electronic excitation of polyatomic organic molecules with donor and acceptor substructures is suggested. The donor hydrocarbon molecular substructures can serve as antennas for low-energy infrared (IR)-photon absorption, which coherently induce collective vibrational excitations (excimols). Due to dipole-dipole interactions, the accumulated energy can transit to the molecular acceptors: dipole-type trap-bonds or molecular parts with π-electron orbits. The analytical expressions for the probability functions of molecular fragmentation and electronic excitation induced by IR-multiphoton absorption are derived. The vibrational energy accumulation and redistribution in the molecules of diphenylalkanes irradiated by infrared photons are considered from the presented point of view.
The Modified Reductive Perturbation Method as Applied to the Boussinesq Equation
Authors: Demiray Hilmi
Published: February 2015

In this work, we extended the application of “the modified reductive perturbation method” to long water waves and obtained the governing equations of Korteweg - de Vries (KdV) hierarchy. Seeking localized travelling wave solutions to these evolution equations we have determined the scale parameter g
1 so as to remove the possible secularities that might occur. To indicate the effectiveness and the elegance of the present method, we studied the problem of the “dressed solitary wave method” and obtained exactly the same result. The present method seems to be fairly simple and practical as compared to the renormalization method and the multiple scale expansion method existing in the current literature
Stable Stationary Solitons of the One-Dimensional Modified Complex Ginzburg-Landau Equation
Authors: Hong Woo-Pyo
Published: February 2015

We report on the existence of a new family of stable stationary solitons of the one-dimensional modified complex Ginzburg-Landau equation. By applying the paraxial ray approximation, we obtain the relation between the width and the peak amplitude of the stationary soliton in terms of the model parameters. We verify the analytical results by direct numerical simulations and show the stability of the stationary solitons.
Variable Separation of (2+1)-Dimensional General Sasa-Satsuma System Obtained by Extended Tanh Approach
Authors: Lai Xian-Jing
Published: February 2015

By means of an extended tanh approach, new types of variable separated solutions u, v, w with two arbitrary lower-dimensional functions of the (2+1)-dimensional general Sasa-Satsuma (GSS) system are derived. Based on the derived variable separation excitation, abundant localized structures such as dromion, peakon and foldon are revealed by selecting appropriate functions p and q. Finally, some elastic and nonelastic interactions among special folded solitary waves are investigated both analytically and graphically. The explicit phase shifts for all the local excitations offered by the common formula are given and applied to these interactions in detail.
Explode-Decay Solitons in the Generalized Inhomogeneous Higher-Order Nonlinear Schrödinger Equations
Authors: Radha Ramaswamy , Kumar V. Ramesh
Published: February 2015

In this paper we investigate the generalized inhomogeneous higher-order nonlinear Schrödinger equations, generated recently by deforming the inhomogeneous Heisenberg ferromagnetic spin system through a space curve formalism [Phys. Lett. A 352, 64 (2006)] and construct their multisoliton solutions, using gauge transformation. The amplitude of the bright soliton solutions generated grows and decays with time, and there is an exchange of energy between soliton trains during interaction.
Finite-Dimensional Hamiltonian Systems from Li Spectral Problem by Symmetry Constraints
Authors: Luo Lin , Fan Engui
Published: February 2015

A hierarchy associated with the Li spectral problem is derived with the help of the zero curvature equation. It is shown that the hierarchy possesses bi-Hamiltonian structure and is integrable in the Liouville sense. Moreover, the mono- and binary-nonlinearization theory can be successfully applied in the spectral problem. Under the Bargmann symmetry constraints, Lax pairs and adjoint Lax pairs are nonlineared into finite-dimensional Hamiltonian systems (FDHS) in the Liouville sense. New involutive solutions for the Li hierarchy are obtained.
Electrochemical Synthesis of Niobium-Hafnium Coatings in Molten Salts
Authors: Kuznetsov Sergey A. , Kuznetsova Svetlana V.
Published: February 2015

Graphite is widely used in technology because of its unique properties. A drawback of graphite is its low heat resistance in oxidizing atmospheres. To increase its heat resistance, Nb-Hf protective coatings were synthesized. Electrodeposition of niobium coatings on graphite with subsequent precise surface alloying of niobium with hafnium was studied. Electrochemical synthesis of Nb-Hf coatings from molten salt systems containing compounds of niobium and hafnium was used too. It was shown that Nb-Hf coatings with a planar growing front can be obtained if the concentration and therefore the limiting current density of the more electropositive component Nb is kept low. Nb-Hf coatings with a thickness of 20 - 30 μm have been obtained in this way from an NaCl-KCl-K2NbF7 (1 wt%)-K2HfF6 (10 wt%)-NaF (5 wt%) melt, above the limiting current density of niobium deposition.
Approximate Solutions for Conservative Nonlinear Oscillators by He’s Homotopy Method
Authors: Beléndez Augusto , Álvarez Mariela L. , Méndez David I. , Fernández Elena , Yebra María S. , Beléndeza Tarsicio
Published: February 2015

He’s homotopy perturbation method is adapted to calculate higher-order approximate periodic solutions of conservative nonlinear oscillators for which the elastic force term is an odd nonlinear function. The method is modified by truncating the infinite series corresponding to the first-order approximate solution before introducing this solution in the second-order linear differential equation, and so on. With carefully constructed iterations, only a few iterations can provide very accurate analytical approximate solutions. An example is presented to illustrate the usefulness and effectiveness of the proposed technique, and comparison of the results obtained using this method with those obtained using other techniques reveals that the former is very effective and convenient.
Application of the Variational Iteration Method to Nonlinear Volterra’s Integro-Differential Equations
Authors: Abbasbandy Saeid , Shivanian Elyas
Published: February 2015

He’s variational iteration method is proposed to solve nonlinear Volterra’s integro-differential equations. The results reveal that this method is very effective and convenient in comparison with other methods.
Existence and Blow up of Solutions of the Cauchy Problem of the Generalized Damped Multidimensional Improved Modified Boussinesq Equation
Authors: Polat Necat
Published: February 2015

We consider the existence, both locally and globally in time, and the blow up of solutions of the Cauchy problem of the generalized damped multidimensional improved modified Boussinesq equation inWs,p(Rn).
Fourier-Bessel Expansions of Electromagnetic Fields in Chiral Cylindrical Structures
Authors: Hillion Pierre
Published: February 2015

To handle electromagnetic wave propagation in a semi-infinite, perfectly conducting, chiral cylinder with a circular base, on which an harmonic Bessel beam impinges, we present a theory relying on the Fourier-Bessel expansion of electromagnetic fields. The chiral medium is successively described by the Tellegen and Post constitutive relations. Conditions of wave propagation are discussed.
The Analysis Approach of Boundary Layer Equations of Power-Law Fluids of Second Grade
Authors: Abbasbandy Saeid , Yürüsoy Muhammet , Pakdemirli Mehmet
Published: February 2015

A powerful analytic technique for nonlinear problems, the homotopy analysis method (HAM), is employed to give analytic solutions of power-law fluids of second grade. For the so-called secondorder power-law fluids, the explicit analytic solutions are given by recursive formulas with constant coefficients. Also, for the real power-law index in a quite large range an analytic approach is proposed. It is demonstrated that the approximate solution agrees well with the finite difference solution. This provides further evidence that the homotopy analysis method is a powerful tool for finding excellent approximations to nonlinear equations of the power-law fluids of second grade.
Nonlinear Instability of Rayleigh-Taylor Waves Subjected to Time-Dependent Temperatures
Authors: El-Dib Yusry O. , Mahmoud Yassmin D.
Published: February 2015

The effect of time-dependent temperatures on surface waves is investigated. Nonlinear stability analysis is performed to describe waves propagating along the interface between two fluids in the presence of mass and heat transfer. Due to the presence of periodic forces, resonance interaction is balanced. The use of a multiple-scales method yields different nonlinear Schrödinger equations. Two parametric nonlinear Schrödinger equations are derived in resonance cases. One of these equations has not been treated before. Its stability criteria depending on linear perturbation are derived. A classical nonlinear Schrödinger equation is derived in the nonresonance case. Stability conditions are obtained analytically and investigated numerically. It is shown that the resonance point depends on the external frequency and that, for Ω ≈ 2ω and Ω ≈ ω, where Ω and ω are the external and disturbance frequency, the external frequency has stabilizing and destabilizing effects, respectively.
Effect of Doping Concentration on Zn1-XMnxO Thin Films Grown by RF Magnetron Sputtering
Authors: Elanchezhiyan Jayaraman , Bhuvana Periyasamy , Gopalakrishnan Nammalvar , Thamizhavel Arumugam , Balasubramanian Thailampillai
Published: February 2015

We have investigated the effect of doping concentration on structural, optical and magnetic properties of Mn-doped ZnO thin films deposited on Si (100) substrate by RF magnetron sputtering. The films have been characterized by X-ray diffraction (XRD), photoluminescence (PL) and superconducting quantum interference device (SQUID) magnetometry. It is observed from XRD, that the increase of Mn content increases the FWHM which indicates the degradation of crystalline quality. The photoluminescence spectrum reveals that the incorporation of Mn ions suppresses the deep level emissions considerably in comparison to those observed in pure ZnO. The near band edge (NBE) emission of Mn-doped films is shifted to the lower energy side (red shift) in comparison to pure ZnO film. The room temperature SQUID magnetometer results reveal that all the films show paramagnetic behaviour due to the lack of interactions among Mn moments.
Thermal Stability of FeS2 Cathode Material in “Thermal” Batteries: Effect of Dissolved Oxides in Molten Salt Electrolytes
Authors: Masset Patrick J.
Published: February 2015

The thermal stability of FeS2 cathode material for thermal batteries is investigated in the LiCl-KCl eutectic containing up to 10 wt% Li2O (used as anti-peak). The results show that the decomposition of pyrite shifts to higher temperatures in the presence of molten salts as the S2 gas is repressed by the liquid phase. For high lithium oxide contents the decomposition temperature of pyrite decreases by 100 °C. In addition Li2FeS2 as reaction product is evidenced whereas Li3Fe2S4 is expected from literature data.
Extraction of Dunham Coefficients from Murrell-Sorbie Parameters
Authors: Lim Teik-Cheng
Published: February 2015

A set of relationships between parameters of the Dunham and Murrell-Sorbie potential energy function is developed. By employing Taylor series expansion and comparison of terms arranged in increasing order of bond length, a set of Dunham coefficients is obtained as functions of Murrell- Sorbie parameters. The conversion functions reveal the importance of factorials in extracting Dunham coefficients from Murrell-Sorbie parameters. Plots of both functions, based on parameters of the latter, reveal good correlation near the equilibrium bond length for a group of diatomic molecules. Potential function relations, such as that shown in this paper, are useful when the preferred/reliable data is based on a potential function different from that adopted in available computational software.
Assessment of the Thermochemical Properties of Actinides in Molten Chlorides
Authors: Masset Patrick I. , Apostolidis Christos , Malmbeck Rikard , Rebizant Jean , Serp Jérôme , Glatz Jean-Paul
Published: February 2015

The electrochemical properties of the chlorides of the actinides U, Pu, Np and Am (AnCl3) were investigated by transient electrochemical techniques in the LiCl-KCl eutectic at 400 - 550 °C. The diffusion coefficients of the cations and the apparent standard potentials of the redox systems on an inert W electrode were measured. The Gibbs energy of dilute solutions of AnCl3 as well as the activity coefficients were derived from electrochemical measurements. In addition, the electrochemical behaviour of the actinides on an Al electrode was investigated. They formed AnAl4 alloys, the formation potentials of which allowed a quantitative recovery of the actinides and their separation from fission products and especially from lanthanides. In addition, the thermochemical properties of the AnAl4 alloys were determined by electrochemical measurements.
Complexation Constants of Ubiquinone,0 and Ubiquinone,10 with Nucleosides and Nucleic Acid Bases
Authors: Rahawi Kassim Y. , Shanshal Muthana
Published: February 2015

UV spectrophotometric measurements were done on mixtures of the ubiquinones Ub,0 and Ub,10 in their monomeric form (c < 10−5 mol/l) with the nucleosides; adenosine, cytidine, 2′-desoxyadenosine, 2′-desoxy-quanosine, guanosine and thymidine, as well as the nucleic acid bases; adenine, cytosine, hypoxanthine, thymine and uracil. Applying the Liptay method, it was found that both ubiquinones form 1 : 1 interaction complexes with the nucleic acid components. The complexation constants were found in the order of 105 mol−1. The calculated ΔG values were negative (∼−7.0 kcal/mol), suggesting a favoured hydrogen bridge formation. This is confirmed by the positive change of the entropy ΔS. The complexation enthalpies ΔH for all complexes are negative, suggesting exothermal interactions.
Variational Approach for the Lane-Emden Equation
Authors: Xu Lan , Zhang Nan
Published: February 2015

A variational principle for the Lane-Emden equation is established by He’s semi-inverse method. Based on the established variational formulation, approximate solutions can be easily obtained by the Ritz method. The obtained solutions are in good agreement with the exact ones. The results show that the variational approach is very effective and convenient for solving the Lane-Emden equation.