Published by De Gruyter

Volume 65 Issue 8-9

Issue of Zeitschrift für Naturforschung A

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Journal Overview

Open Access June 2, 2014

Is the Phase of Plane Waves an Invariant?

Young-Sea Huang

Page range: 615-617

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Abstract

Based on the invariance of the phase of waves, plane waves were shown to propagate with negative frequencies in a medium which moves at ’superluminal’ speed opposite to the propagation direction of the plane waves. The validity of the invariance of the phase of plane waves was then called into question. A radical change of the conventional concept of plane waves is recently proposed to solve the problem of negative frequency of waves.We will explicitly point out flaws in that proposal. Thus, the validity of the invariance of the phase of plane waves remains questionable

Open Access June 2, 2014

Long-Wave Instabilities of Viscoelastic Fluid Film Flowing Down an Inclined Plane with Linear Temperature Variation

Asim Mukhopadhyay, Samadyuti Haldar

Page range: 618-632

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Abstract

The two dimensional flow of a viscoelastic fluid (weakly elastic) represented by Walters’ B” model running down an inclined heated plane with linear temperature variation has been investigated in the finite amplitude regime. A long-wave expansion method obtains a nonlinear evolution equation of the filminterface. A normal mode approach and the method of multiple scales are used to obtain the linear and nonlinear stability solutions for the film flow. The study reveals that both supercritical stability and subcritical instability are possible for this type of film flow. The influence of the viscoelastic parameter and the Marangoni number on the different zones, the amplitude of the disturbances on sub/supercritical region, and the nonlinear phase speed in the supercritical region are also investigated. It is interesting to note that the influence of the viscoelastic parameter on the above aspects are very significant at low Marangoni number, while it has very feeble impact at high Marangoni number. Finally, the results thus determined are interpreted physically

Open Access June 2, 2014

New Travelling Wave Solutions of Burgers Equation with Finite Transport Memory

Rathinasamy Sakthivel, Changbum Chun, Jonu Lee

Page range: 633-640

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Abstract

The nonlinear evolution equations with finite memory have a wide range of applications in science and engineering. The Burgers equation with finite memory transport (time-delayed) describes convection-diffusion processes. In this paper, we establish the new solitary wave solutions for the time-delayed Burgers equation. The extended tanh method and the exp-function method have been employed to reveal these new solutions. Further, we have calculated the numerical solutions of the time-delayed Burgers equation with initial conditions by using the homotopy perturbation method (HPM). Our results show that the extended tanh and exp-function methods are very effective in finding exact solutions of the considered problem and HPM is very powerful in finding numerical solutions with good accuracy for nonlinear partial differential equations without any need of transformation or perturbation

Open Access June 2, 2014

On Characterization of Time-Like Horizontal Biharmonic Curves in the Lorentzian Heisenberg Group Heis³

Essin Turhan, Talat Körpinar

Page range: 641-648

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Abstract

In this paper, we study energy of time-like horizontal biharmonic curves in the Lorentzian Heisenberg group Heis 3 . We characterize the biharmonic curves in terms of their curvature and torsion. We prove that all of the biharmonic curves are helices. Finally, we study the mechanics of biharmonic curves and provide conditions for energy of horizontal biharmonic curves

Open Access June 2, 2014

Periodic Wave Solutions of a Generalized KdV-mKdV Equation with Higher-Order Nonlinear Terms

Zi-Liang Li

Page range: 649-657

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Abstract

The Jacobin doubly periodic wave solution, the Weierstrass elliptic function solution, the bell-type solitary wave solution, the kink-type solitary wave solution, the algebraic solitary wave solution, and the triangular solution of a generalized Korteweg-de Vries-modified Korteweg-de Vries equation (GKdV-mKdV) with higher-order nonlinear terms are obtained by a generalized subsidiary ordinary differential equation method (Gsub-ODE method for short). The key ideas of the Gsub-ODE method are that the periodic wave solutions of a complicated nonlinear wave equation can be constructed by means of the solutions of some simple and solvable ODE which are called Gsub-ODE with higherorder nonlinear terms

Open Access June 2, 2014

Adomian Decomposition Method for Approximating the Solutions of the Bidirectional Sawada-Kotera Equation

Xian-Jing Lai, Xiao-Ou Cai

Page range: 658-664

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Abstract

In this paper, the decomposition method is implemented for solving the bidirectional Sawada- Kotera (bSK) equation with two kinds of initial conditions. As a result, the Adomian polynomials have been calculated and the approximate and exact solutions of the bSK equation are obtained by means of Maple, such as solitary wave solutions, doubly-periodic solutions, two-soliton solutions. Moreover, we compare the approximate solution with the exact solution in a table and analyze the absolute error and the relative error. The results reported in this article provide further evidence of the usefulness of the Adomian decomposition method for obtaining solutions of nonlinear problems

Open Access June 2, 2014

Effect of an Induced Magnetic Field on the Peristaltic Motion of Phan-Thien-Tanner (PTT) Fluid

Tasawar Hayat, Saima Noreen, Nasir Ali

Page range: 665-676

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Abstract

This article looks at the influence of an induced magnetic field on peristaltic motion of an incompressible fluid in a planar channel with non-conductive walls. Peristaltic flow is generated by a sinusoidal wave travelling down its walls. The problem formulation in a wave frame of reference moving with velocity of wave is established. Mathematical relations for the stream function, pressure gradient, magnetic force function, and axial induced magnetic field are constructed. The pressure rise and frictional force are discussed by performing numerical integration. Effects of many sundry parameters entering into the governing problem are examined by plotting graphs

Open Access June 2, 2014

Numerical Inversion of the Abel Integral Equation using Homotopy Perturbation Method

Sunil Kumar, Om P. Singh

Page range: 677-682

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Abstract

Many problems in physics like reconstruction of the radially distributed emissivity from the line-of-sight projected intensity, the 3-D image reconstruction from cone-beam projections in computerized tomography, etc. lead naturally, in the case of radial symmetry, to the study of Abel’s type integral equation. The aim of this communication is to propose a new algorithm for the Abel inversion by using the homotopy perturbation method

Open Access June 2, 2014

Magnetohydrodynamic Three-Dimensional Flowof a Second-Grade Fluid with Heat Transfer

Tasawar Hayat, Muhammad Nawaz

Page range: 683-691

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Abstract

An analysis has been carried out for the heat transfer on steady boundary layer flow of a secondgrade fluid bounded by a stretching sheet. The magnetohydrodynamic nature of the fluid is considered in the presence of Hall and ion-slip currents. The nonlinear mathematical problem is computed by a powerful tool, namely, the homotopy analysis method (HAM). A comparative study between the present and existing limiting results is carefully made. Convergence regarding the obtained solution is discussed. Skin friction coefficients and Nusselt number are analyzed. Effects of embedded parameters on the dimensionless velocities and temperature are examined

Open Access June 2, 2014

Modification of Lesnic’s Approach and New Analytic Solutions for Some Nonlinear Second-Order Boundary Value Problems with Dirichlet Boundary Conditions

Abdelhalim Ebaid

Page range: 692-696

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Abstract

For solving nonlinear boundary value problems (BVPs), a main difficulty of using Adomian’s method is to find a canonical form which takes into account all the boundary conditions of the problem. This difficulty is overcome by using a modification for Lesnic’s approach developed in this paper. The effectiveness of the proposed procedure is verified by two nonlinear problems: the nonlinear oscillator equation and Troesch’s problem

Open Access June 2, 2014

Heat Transfer Analysis on the Peristaltic Motion with Slip Effects

Tasawar Hayat, Zaheer Asghar

Page range: 697-704

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Abstract

The purpose of this paper is to highlight the combined effects of heat transfer and slip characteristics of magnetohydrodynamic (MHD) fluid with variable viscosity in a channel. The slip condition is imposed in terms of shear stress. An analysis is performed to derive the perturbation solution for long wavelength and small Reynolds number assumptions. Expressions of stream function, temperature and heat transfer coefficient are constructed and discussed

Open Access June 2, 2014

The Simulation of the Two-Dimensional Ising Model on the Creutz Cellular Automaton for the Fractals Obtained by Using the Model of Diffusion-Limited Aggregation

Ziya Merdan, Mehmet Bayirli, Mustafa Kemal Ozturk

Page range: 705-710

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Abstract

The fractals are obtained by using the model of diffusion-limited aggregation (DLA) for the lattice with L = 80, 120, and 160. The values of the fractal dimensions are compared with the results of former studies. As increasing the linear dimensions they are in good agreement with those. The fractals obtained by using the model of DLA are simulated on the Creutz cellular automaton by using a two-bit demon. The values computed for the critical temperature and the static critical exponents within the framework of the finite-size scaling theory are in agreement with the results of other simulations and theoretical values

Open Access June 2, 2014

Influence of Thermal Radiation on the Unsteady Mixed Convection Flow of a Jeffrey Fluid over a Stretching Sheet

Tasawar Hayat, Meraj Mustafa

Page range: 711-719

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Abstract

This study is concerned with the effect of thermal radiation on the unsteady mixed convection flow of a Jeffrey fluid past a porous vertical stretching surface. The arising problems of flow and heat transfer are solved analytically by employing homotopy analysis method (HAM). It is observed that the flow field is influenced appreciably by the unsteadiness parameter ζ , suction parameter S , mixed convection parameter λ , Deborah number β , Prandtl number Pr , and the radiation parameter Nr . Our performed computations depict that the heat transfer rate is increased with increasing values of Pr , Nr , and ζ

Open Access June 2, 2014

Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF₃OSO₃ Radical

Carlos J. Cobos, Adela E. Croce

Page range: 720-724

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Abstract

The UV-visible absorption spectrum of the recently reported CF 3 OSO 3 radical has been studied by using the time-dependent generalization of the density functional theory (TDDFT). For this a set of eleven hybrid functionals combined with the 6-311+G(3df) basis set were employed. The main features of the three experimental absorption bands of CF 3 OSO 3 recorded over the 220 - 530 nm range are well reproduced by the calculations. A dissociation enthalpy for the CF 3 O-SO 3 bond of 19.1 kcal mol − 1 is predicted at the BAC-G3MP2//B3LYP/6-311+G(3df) level of theory

Open Access June 2, 2014

The Effects of the Layer-Dependent Interaction Parameters on the Phase Diagrams and Polarizations of the Ferroelectric Thin Film

Xianjun Zhang, Baohua Teng, Chundong Wang, Zhaoxin Lu, Xiaohua Lu

Page range: 725-732

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Abstract

While the exchange interaction and the transverse field parameters are changed with the layers of the ferroelectric thin film, the properties of phase transition of the transverse field Ising model have been studied within the framework of the mean field approximation. The phase diagrams and polarizations of the ferroelectric thin film have been calculated numerically in the different situations of the interaction parameters changed with the layers. The results show that various layer-dependent parameters changed gradually layer by layer have sensitive effects on the phase diagrams and the polarizations of the n-layer ferroelectric thin film

Open Access June 2, 2014

Crystallization Kinetics in Liquid Crystals with Hexagonal Precursor Phases by Calorimetry

Sunkara Padmaja, Narayanan Ajita, Maddasani Srinivasulu, Sriram Ramchandra Girish, Venkata Gopala Krishna Murthy Pisipati, Dakshina Murthy Potukuchi

Page range: 733-744

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Abstract

Design and characterization of Schiff based liquid crystalline nO.m compounds exhibiting hexagonal smectic phases are reported. Crystallization kinetics investigations are carried out in the liquid crystals (LCs) exhibiting hexagonal ordered orthogonal and tilted precursor LC phases by calorimetry. The Avrami theory is referred and results are analyzed. Influence of molecular ordering, structure, and dimensionality of the LC precursor phase on kinetics is studied. Effect of shape and flexibility of the molecule for nucleation and growth processes is investigated. Varying rate of kinetics reflects upon the transit of the system from constant type to independent type of nucleation. The trends in the Avrami parameter b and exponent n suggest sporadic nucleation. Crystal growth is interpreted as heterogeneous permeation of layered domains (or aggregates) formed by needle shaped calamitic molecules. Calorimetric observations at different crystallization temperatures CT and hold time t infer diffusion mediated crystallization

Open Access June 2, 2014

Raman Spectroscopic Study of a New Type of Room Temperature ZnCl₂-DMSO₂ Molten Salts

Chao-Chen Yanga, Hsin-Yi Hsu

Page range: 745-748

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Abstract

In this study, Raman spectra of binary zinc chloride-dimethylsulfone (ZnCl2-DMSO2) melts have been measured. The intra-molecular vibrations of group and ionic species have been confirmed and discussed. From the Raman spectrum analysis and discussions, the equilibrium reaction equation about the complex ions forming in the ZnCl2-DMSO2 melt is submitted, such as n ZnCl2+n(n−2)(CH 3 ) 2 SO 2 ⇔ 2ZnCl n 2−n +(n−2) Zn[(CH 3 ) 2 SO 2 ] n 2+ , (n ≧ 3). However, the Raman spectra reveal that the ZnCl 4 2− (375 cm −1 ) and ZnCl 3 − (290 cm −1 ) complexes are the major ions for the 40 - 90 mol%ZnCl 2 melts; furthermore, as the DMSO 2 content is increased, the binary melt advantage the forming of Zn[(CH 3 ) 2 SO 2 ] n 2+ complex ion and promote its transport characteristic

Open Access June 2, 2014

Volumetric, Viscometric, and Ultrasonic Properties of Liquid Mixtures of Cyclohexane with Alkanols at Different Temperatures

Anwar Ali, Shadma Tasneem, Firdosa Nabi

Page range: 749-760

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Abstract

The densities (ρ), viscosities (η), and ultrasonic speeds (u) of pure cyclohexane, 1-butanol, 2- butanol, and those of their binary mixtures, with cyclohexane as common component, covering the whole composition range have been measured at 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K. From the experimental data the excess molar volume (V E ), deviations in isentropic compressibility (Δk s ), deviations in viscosity (Δη), deviations in ultrasonic speed (Δu), deviations in acoustic impedance (ΔZ), deviations in internal pressure (ΔPi), excess Gibbs free energy of activation (Δ G*E ), entropies (ΔS*), and enthalpies (ΔH*) of activation of viscous flow have been determined. The sign and magnitude of these parameters were found to be sensitive towards interactions prevailing in the studied systems. Partial molar volumes (V 0 φ,2 ) and partial molar compressibilities (K 0 φ,2 ) of 1-butanol and 2-butanol in cyclohexane have also been evaluated. Moreover, V E values were theoretically predicted by using Flory’s statistical theory. The variations of derived parameters mentioned above with composition offer a convenient method to study the nature and extent of interactions between the component molecules of the liquid mixtures, not easily obtained by other means

About this journal

Objective
A Journal of Physical Sciences: Zeitschrift für Naturforschung A (ZNA) is an international scientific journal which publishes original research papers from all areas of experimental and theoretical physics. Authors are encouraged to pay particular attention to a clear exposition of their respective subject, addressing a wide readership. In accordance with the name of our journal, which means “Journal for Natural Sciences”, manuscripts submitted to ZNA should have a tangible connection to actual physical phenomena. In particular, we welcome experiment-oriented contributions.

Manuscripts considered for publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A undergo high-level refereeing. Mere formal correctness of a paper is not sufficient for its acceptance. Moreover, articles reporting a merely marginal extension of already existing knowledge are considered unsatisfactory. Instead, the key quality a publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A should possess is that it makes a genuine contribution to the advancement of its topic.

Topics

Atomic, Molecular & Optical Physics
Chemical Physics
Dynamical Systems & Nonlinear Phenomena
Fundamental Concepts of Physical Sciences
Gravitation & Cosmology
Hydrodynamics & Plasma Physics
Nuclear Physics & Particle Physics
Quantum Field Theory
Solid State Physics & Materials Science
Thermodynamics & Statistical Physics
Article formats
Original research articles, research notes, letters and review articles from all areas of theoretical and experimental physics

Information on submission process

Volume 65 Issue 8-9

Issue of Zeitschrift für Naturforschung A

Is the Phase of Plane Waves an Invariant?

Abstract

Long-Wave Instabilities of Viscoelastic Fluid Film Flowing Down an Inclined Plane with Linear Temperature Variation

Abstract

New Travelling Wave Solutions of Burgers Equation with Finite Transport Memory

Abstract

On Characterization of Time-Like Horizontal Biharmonic Curves in the Lorentzian Heisenberg Group Heis3

Abstract

Periodic Wave Solutions of a Generalized KdV-mKdV Equation with Higher-Order Nonlinear Terms

Abstract

Adomian Decomposition Method for Approximating the Solutions of the Bidirectional Sawada-Kotera Equation

Abstract

Effect of an Induced Magnetic Field on the Peristaltic Motion of Phan-Thien-Tanner (PTT) Fluid

Abstract

Numerical Inversion of the Abel Integral Equation using Homotopy Perturbation Method

Abstract

Magnetohydrodynamic Three-Dimensional Flowof a Second-Grade Fluid with Heat Transfer

Abstract

Modification of Lesnic’s Approach and New Analytic Solutions for Some Nonlinear Second-Order Boundary Value Problems with Dirichlet Boundary Conditions

Abstract

Heat Transfer Analysis on the Peristaltic Motion with Slip Effects

Abstract

The Simulation of the Two-Dimensional Ising Model on the Creutz Cellular Automaton for the Fractals Obtained by Using the Model of Diffusion-Limited Aggregation

Abstract

Influence of Thermal Radiation on the Unsteady Mixed Convection Flow of a Jeffrey Fluid over a Stretching Sheet

Abstract

Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF3OSO3 Radical

Abstract

The Effects of the Layer-Dependent Interaction Parameters on the Phase Diagrams and Polarizations of the Ferroelectric Thin Film

Abstract

Crystallization Kinetics in Liquid Crystals with Hexagonal Precursor Phases by Calorimetry

Abstract

Raman Spectroscopic Study of a New Type of Room Temperature ZnCl2-DMSO2 Molten Salts

Abstract

Volumetric, Viscometric, and Ultrasonic Properties of Liquid Mixtures of Cyclohexane with Alkanols at Different Temperatures

Abstract

On Characterization of Time-Like Horizontal Biharmonic Curves in the Lorentzian Heisenberg Group Heis³

Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF₃OSO₃ Radical

Raman Spectroscopic Study of a New Type of Room Temperature ZnCl₂-DMSO₂ Molten Salts