Published by De Gruyter

Volume 66 Issue 10-11

Issue of Zeitschrift für Naturforschung A

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Contents
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Open Access June 2, 2014

Analytic Solution of Fractional-Order Heat- and Wave-Like Equations Using Generalized n-dimensional Differential Transform Method

Vipul K. Baranwal, Ram K. Pandey, Manoj P. Tripathi, Om P. Singh

Page range: 581-590

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Abstract

In this paper, we have introduced a generalized n -dimensional differential transform method to propose a user friendly algorithm to obtain the closed form analytic solution for n -dimensional fractional heat- and wave-like equations. Three examples are given to establish the simplicity of the algorithm. In Example 5.3, we show that ten terms of the series representing the solution, even in fractional order, give a very accurate solution.

Open Access June 2, 2014

A New Method for Solving Steady Flow of a Third-Grade Fluid in a Porous Half Space Based on Radial Basis Functions

Saeed Kazem, Jamal Amani Rad, Kourosh Parand, Saied Abbasbandy

Page range: 591-598

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Abstract

In this study, flow of a third-grade non-Newtonian fluid in a porous half space has been considered. This problem is a nonlinear two-point boundary value problem (BVP) on semi-infinite interval. We find the simple solutions by using collocation points over the almost whole domain [0;∞). Our method based on radial basis functions (RBFs) which are positive definite functions. We applied this method through the integration process on the infinity boundary value and simply satisfy this condition by Gaussian, inverse quadric, and secant hyperbolic RBFs.We compare the results with solution of other methods.

Open Access June 2, 2014

Homotopy Analysis Method for Ablowitz–Ladik Lattice

Benny Y. C. Hon, Engui Fan, Qi Wang

Page range: 599-605

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Abstract

In this paper, the homotopy analysis method is successfully applied to solve the systems of differential-difference equations. The Ablowitz-Ladik lattice system are chosen to illustrate the method. Comparisons between the results of the proposed method and exact solutions reveal that the homotopy analysis method is very effective and simple in solving systems of differential-difference equations.

Open Access June 2, 2014

Thermal Radiation Effects on the Mixed Convection Stagnation-Point Flow in a Jeffery Fluid

Tasawar Hayat, Sabir Ali Shehzad, Muhammad Qasim, Saleem Obaidat

Page range: 606-614

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Abstract

This study describes the mixed convection stagnation point flow and heat transfer of a Jeffery fluid towards a stretching surface. Mathematical formulation is given in the presence of thermal radiation. The Rosseland approximation is used to describe the radiative heat flux. Similarity transformations are employed to reduce the partial differential equations into the ordinary differential equations which are then solved by a homotopy analysis method (HAM). A comparative study is made with the known numerical solutions in a limiting sense and an excellent agreement is noted. The characteristics of involved parameters on the dimensionless velocity and temperature are also examined. It is noticed that the velocity increases with an increase in Deborah number. Further, the temperature is a decreasing function of mixed convection parameter. We further found that for fixed values of other parameters, the local Nusselt number increases by increasing suction parameter and Deborah number.

Open Access June 2, 2014

N-tangle, Entangled Orthonormal Basis, and a Hierarchy of Spin Hamilton Operators

Willi-Hans Steeb, Yorick Hardy

Page range: 615-619

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Abstract

An N -tangle can be defined for the finite dimensional Hilbert space H = C 2N , with N = 3 or N even.We give an orthonormal basis which is fully entangled with respect to this measure.We provide a spin Hamilton operator which has this entangled basis as normalized eigenvectors if N is even. From these normalized entangled states a Bell matrix is constructed and the cosine-sine decomposition is calculated. If N is odd the normalized eigenvectors can be entangled or unentangled depending on the parameters.

Open Access June 2, 2014

A New Approach to Van der Pol’s Oscillator Problem

Yasir Khan, M. Madani, A. Yildirim, M. A. Abdou, Naeem Faraz

Page range: 620-624

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Abstract

In this paper, we will consider the Laplace decomposition method (LDM) for finding series solutions of nonlinear oscillator differential equations. The equations are Laplace transformed and the nonlinear terms are represented by He’s polynomials. The solutions are compared with the numerical (fourth-order Runge-Kutta) solution and the solution obtained by the Adomian decomposition method. The suggested algorithm is more efficient and easier to handle as compared to the numerical method. The results illustrate that LDM is an appropriate method in solving the highly nonlinear equations.

Open Access June 2, 2014

Multiple Soliton Solutions for a Variety of Coupled Modified Korteweg–de Vries Equations

Abdul-Majid Wazwaz

Page range: 625-631

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Abstract

We make use of Hirota’s bilinear method with computer symbolic computation to study a variety of coupled modified Korteweg-de Vries (mKdV) equations. Multiple soliton solutions and multiple singular soliton solutions are obtained for each coupled equation. The resonance phenomenon of each coupled mKdV equation is proved not to exist.

Open Access June 2, 2014

Variational Approach to Impulsive Differential Equations Using the Semi-Inverse Method

Ji-Huan He

Page range: 632-634

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Abstract

The semi-inverse method is used to establish a variational principle for the Dirichlet boundary value problem with impulses. All the boundary conditions can be obtained as natural conditions by making the variational principle stationary.

Open Access June 2, 2014

Unsteady Three-Dimensional Flow in a Second-Grade Fluid Over a Stretching Surface

Tasawar Hayat, Ambreen Safdar, Muhammad Awais, Awatif A. Hendi

Page range: 635-642

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Abstract

The three-dimensional unsteady flow induced in a second-grade fluid over a stretching surface has been investigated. Nonlinear partial differential equations are reduced into a system of ordinary differential equations by using the similarity transformations. The homotopy analysis method (HAM) has been implemented for the series solutions. Graphs are displayed for the effects of different parameters on the velocity field.

Open Access June 2, 2014

Laser-Induced Breakdown Spectroscopy of Molten Metals: Influence of Sample Temperature

Tomáš Vaculovič, Zbyněk Zvěřina, Vítězslav Otruba, Viktor Kanický

Page range: 643-648

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Abstract

The aim of this work was to determine the influence of sample temperature on the laser-induced microplasma (LIP) emission intensity and to ascertain the possibility of laser-induced breakdown spectroscopy (LIBS) utilization for the monitoring of impurities in molten metals. Pure low-melting metals (bismuth, gallium, indium, lead, tin, and zinc) were used for all experiments. It was found out that the LIP emission increases linearly with increasing temperature within the range 25 °C to 70 °C above the melting point of the metal. The slope of this change in LIP intensity is related to the transition probability of a given emission line. If the LIP intensity of given solid and molten metals are compared, then their relative change is related to the coefficient of thermal conductivity. The LIBS shows possibilities for the identification of impurities in molten metals. Amounts of impurities in the order of tens mg=kg can be identified.

Open Access June 2, 2014

Viscosity of Molten Rare Earth Metal Trichlorides II. Cerium Subgroup

Alexei Potapov, Yuzuru Sato

Page range: 649-655

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Abstract

The kinematic viscosity of molten LaCl 3 , CeCl 3 , PrCl 3 , NdCl 3 , and SmCl 3 was measured directly by using a capillary viscometer made of quartz and a transparent electric furnace. Viscosity of molten PmCl 3 and EuCl 3 was estimated using common tendencies in the lanthanides row. The dynamic viscosity was computed by using the most reliable density data taken from literature. The viscosity of molten lanthanides trichlorides at the same temperature changes slightly within a cerium lanthanides subgroup. Molten EuCl 3 perhaps has abnormally low viscosity.

Open Access June 2, 2014

Phase Transition and Elastic Properties of Zinc Sulfide Under High Pressure from First Principles Calculations

Dai Wei, Song Jin-Fan, Wang Ping, Lu Cheng, Lu Zhi-Wen, Tan Xiao-Ming

Page range: 656-660

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Abstract

A theoretical investigation on structural and elastic properties of zinc sulfide semiconductor under high pressure is performed by employing the first-principles method based on the density functional theory. The calculated results show that the transition pressure P t for the structural phase transition from the B3 structure to the B1 structure is 17:04 GPa. The calculated values are generally speaking in good agreement with experiments and with similar theoretical calculations.

Open Access June 2, 2014

Phase Diagrams of Mesogenic Binary Systems of Cobalt(II) and Univalent Metal Octanoates

Inna I. Tokmenko, Tatyana A. Mirnaya, Galina G. Yaremchuk

Page range: 661-667

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Abstract

The phase diagrams of binary systems of cobalt(II) octanoate and lithium, sodium, potassium, and thallium(I) octanoates have been studied by differential thermal analysis and polythermal polarization microscopy. In all systems, continuous or limited liquid crystalline solutions of smectic modification are formed. The temperature and composition ranges of the formation of liquid crystals and glasses have been determined.

Open Access June 2, 2014

Electrochemical Behaviour of Hydrogen in Low-Viscosity Phosphonium Ionic Liquids

M. Matsumiya, K. Tsunashima, S. Kodama

Page range: 668-674

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Abstract

The electrochemical and diffusive properties of hydrogen in low-viscosity phosphonium ionic liquids were investigated by the electrochemical methods such as cyclic voltammetry and chronoamperometry. The hydrogen redox reactions were concluded to be a quasi-reversible system in phosphonium-based ionic liquids. The diffusion coefficients of hydrogen in these ionic liquids were of the order of 10 -10 m 2 s -1 at 25 ° C. Additionally, the obtained activation energy of the diffusion process for hydrogen was 11.2 - 15:9 kJ mol -1 estimated from the temperature dependence of the diffusion coefficients. A new type of proton conducting medium such as triethylphosphonium bis(trifluoromethylsulfonyl) amide was synthesized by the neutralization reaction, because the trialkylphosphine-based ionic liquids with good stability at higher temperature and high conductivity were appropriate candidates. This proton conducting membrane containing the ionic liquids with trialkylphosphine-based cations and the polyvinylidenefluoride-co-hexafluoropropylene has been fabricated in the present study. The proton conducting membrane exhibits relatively high ionic conductivity along with good mechanical stability.

Open Access June 2, 2014

Genetic Evolutionary Approach for Cutting Forces Prediction in Hard Milling

Fatih Taylan, Cengiz Kayacan

Page range: 675-680

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Abstract

Hard milling is a very common used machining procedure in the last years. Therefore the prediction of cutting forces is important. The paper deals with this prediction using genetic evolutionary programming (GEP) approach to set mathematical expression for out cutting forces. In this study, face milling was performed using DIN1.2842 (90MnCrV8) cold work tool steel, with a hardness of 61 HRC. Experimental parameters were selected using stability measurements and simulations. In the hard milling experiments, cutting force data in a total of three axes were collected. Feed direction ( F x ) and tangential direction ( F y ) cutting forces generated using genetic evolutionary programming were modelled. Cutting speed and feed rate values were treated as inputs in the models, and average cutting force values as output. Mathematical expressions were created to predict average F x and F y forces that can be generated in hard material milling.

Open Access June 2, 2014

Research on Prediction of Three Great Earthquakes During the Beginning of the 21st Century in the Northern Xizang Plateau

Kepei Men

Page range: 681-691

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Abstract

The northern Xizang Plateau is a main seismic zone inWest China. Since 1700, M ≥ 7 earthquakes have had an obvious commensurability and orderliness in this region. The main ordered values are 106∼107a, 77∼78a, 53∼54a, 26∼27a, 11∼12a, and 3∼4a. According to the information forecasting theory ofWen-BoWeng (W. B.Weng, Fundamentals of Forecasting Theory. Petroleum Industry Press, Beijing 1984 (in Chinese)), combining ordered analysis with complex network technology, we try to explore the practical method for M ≥ 7 earthquake prediction with Chinese characteristics, and build a informational ordered network structure of M ≥7 earthquakes in the northern Xizang Plateau. In this paper, we study the prediction of three great earthquakes (the 2001 Kunlunshan M8.1 , the 2008Wenchuan M8.0 , and the 2010 M7.1 Yushu earthquake) during the beginning of the 21st century based on the method of ordered network structure, and give many famous earthquake examples in China and abroad. Meanwhile, the cause of formation about the Wenchuan and Yushu earthquake has been discussed primarily. At last, we present some new prediction opinions: the future M ≥7 earthquakes will happen in 2014 - 2015, 2026 - 2027, and 2030 pre and post in this region. The results show that this method has a unique effect on moderate term and long term prediction for great earthquakes.

Open Access June 2, 2014

Inner-Resonance for a Coupled Oscillator Arising in a Cubic Nonlinear Packaging System with Critical Component

Jun Wang, Fang Duan, Rui-Hua Yang, Zheng-Biao Li, Li-Xin Lu, Hong Xiang

Page range: 692-695

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Abstract

In this paper, a dynamic model was proposed for a cushioning packaging system. Conditions for resonance were obtained by applying the variational iteration method (VIM), which should be avoided in the cushioning packaging design.

Open Access June 2, 2014

Autonomous Dynamical Systems, Explicitly Time Dependent First Integrals, and Gradient Systems

Willi-Hans Steeb

Page range: 696-698

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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 & Chemical Physics
Dynamical Systems & Nonlinear Phenomena
Gravitation & Cosmology
Hydrodynamics
Quantum 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

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