Vyankat Pawar, Maharashtra Udayagiri Mahavidyalaya, Physics and Electronics, India
Abstract: The dielectric relaxation study of diethanolamine with triethanolamine binary mixture have been determined over the frequency range of 10 MHz to 20 GHz, at 15, 20, 25, 28, and 30oC using time domain reflectometry (TDR) method for 11 concentrations of the system. The present work reveals molecular interaction between same multi-functional groups [−OH and –NH2] of the alkanolamines (diethanolamine and triethanolamine) using different models (Such as Debye model, Excess model, Kirkwood model and Bruggeman model). The dielectric parameters viz. static dielectric constant (0), dielectric constant at high frequency (∞) and relaxation time () have been obtained with Debye equation characterized by a single relaxation time without relaxation time distribution by the least squares fit method. The values of static dielectric constant increases up to their melting points and then it decreases with increasing temperatures. This behavior of the static dielectric constant indicates the change of phase from semi-solid to liquid state of the system. At the melting points, the values of relaxation time suddenly drop down.
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Won-Kwang Park, Kookmin University, Mathematics, Korea, Republic of
Abstract: From a physical point of view, purpose of inverse scattering problem is determining unknown characteristics of an object from measured scattered field data. For this purpose, various algorithms for reconstructing an unknown object have been suggested, most of those being based on Newton-type iteration schemes. Yet, for successful application of them, a good initial guess is essentially needed. Without this, one might suffer from large computational costs or non-convergence issue. To overcome such difficulties, alternative non-iterative imaging algorithms have been suggested. Among them, MUltiple SIgnal Classification (MUSIC) has been proposed and applied to the various inverse scattering problems. It is confirmed that this is very fast, effective, robust, and can not only be applied to single but also to multiple targets. However, in many works, the application of MUSIC considered in full-view inverse scattering problems. In limited-view problems, MUSIC is still applied heuristically. Motivated by this fact, we carefully analyze the structure of MUSIC for imaging of arc-like perfectly conducting cracks in the limited-view inverse scattering problem by establishing a relationship between MUSIC imaging function and infinite series of Bessel functions of integer order of the first kind. From the identified structure, discover a necessary condition for applying MUSIC in limited-view inverse scattering problem to guarantee good results.
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Julio S Espinoza Ortiz, Universidade Federal de Goias, Departamento de Física, Brazil
Roberto E Lagos, IGCE Universidade Estadual Paulista, Física, Brazil
Abstract: Research on modeling the mechanical behavior of soft tissue has growing demand for applications on surgical simulations, pursuing in real time, precise and fast calculations of tissue mechanical deformations. For almost all biological soft tissue, the stress-strain curve exhibit a hysteresis loop showing a nonlinear relationship, meanwhile under different strain rates they are mechanically not very sensitive. Moreover, their hysteresis loop-area does not depend on the strain rate. Hysteresis, relaxation and creep are common features of viscoelastic mechanical behavior. As for most materials, their mechanical properties depend to a large extent on the environmental conditions, mainly the temperature and the type of loading regime applied to the material. The time dependence of a viscoelastic material could be better understood by considering it as composed by an elastic solid and a viscous fluid. Different types of mechanical devices can be constructed provided a particular configuration of elastic springs and dashpots. In this work we explore the possibility to obtain most of the soft tissue mechanical behavior by considering a Kelvin's device coupled to a set of {\it\,in parallel} Maxwell's devices. Then, the resulting model composed of a long series of modified Kelvin bodies must span a broad range of characteristic times resulting in a suitable model for soft tissue simulation. Soft tissue mechanical response under driving static and dynamic deformations on {\it\,2-Dim} system are considered, given the applied stress. We compute the strain deformations as a function of time. We obtain a set of coupled Volterra integral equations, solved via the extended trapezoidal rule scheme, and we use the Newton-Raphson method when solving the remaining coupled equations.
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jean-pierre magnot, academie de clermont-ferrand, lycée jeane d'arc, France (Metropolitan)
Abstract: Using the procedure initiated in [J-P. Magnot, International Journal of Geometric Methods in Modern Physics 10(9). articleID 1350043 (2013)], we deform Lax-type equations though a scaling of the time parameter. This gives an equivalent (deformed) equation which is integrable in terms of power series of the scaling parameter. We then describe a regular Frölicher Lie group of symmetries of this deformed equation.
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Marco Zoli, University of Camerino, School of Science and Technology, Italy
Abstract: Many experiments have demonstrated that DNA exhibits sequence-dependent bending and torsional flexibility which may have biological relevance in the DNA-protein interplay. Such properties have been investigated by several experimental methods including gel electrophoresis, crystallography and, above all, DNA cyclization which permits to test the circularization rates of DNA sequences in the presence of ligase enzymes. From a theoretical viewpoint, cyclization rates can been analyzed via computation of the J-factors which are essentially given by the ratio of the partition functions of circular and linear structures. This program is carried out in the present work by means of the previously developed path integral method for DNA [1-3]. Both homogeneous and heterogeneous molecules are studied to detect the effects of the sequence specificities on the cyclization probabilities. The latter are also evaluated as a function of the sequence length. [1] M. Zoli, Journal of Theoretical Biology Vol. 354, 95-104 (2014). [2] M. Zoli, Soft Matter Vol. 10, 4304-4311 (2014). [3] M. Zoli, The Journal of Chemical Physics Vol. 141, 174112 (2014).
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Sy-Sang Liaw, National Chung Hsing University, Physics, Taiwan
Abstract: There exist a few methods for generating time series of a given fractal dimension. But none of them produces series sequentially. For example, the Random Midpoint Displacement method begins with the two end points of the intended series and feeds in points in between repeatedly. The spectral method prescribes a set of points satisfying a power law and makes a Fourier Transform to obtain the intended fractal series. Sequentially generating a fractal series of dimension 1.5 is easy, simply by simulating a one-dimension random walk step by step. It is also straightforward to generate a series of random numbers one by one to yield a fractal series of dimension 2.0. Unfortunately, fractal time series of a given dimension other than 1.5 and 2.0 have never being generated in a sequential manner. Real time series are recorded one data at a time, that is, sequentially. Many of them are fractals, and their dimensions could be 1.5, 2.0, or others, or even scale-dependent. How do these real systems generate its sequential data with a prescribed fractal dimension? In this report, we present a multi-scale N-step algorithm for generating fractal sequences sequentially. The algorithm predefines the probability, which is obtained in advance from random sequences we generated with a given fractal dimension, for upward change at any time as a function of the N changes in previous N steps. Sequences generated from this N-step algorithm have a monofractal dimension up to certain time scale but change into a random-walk sequence with fractal dimension 1.5 at larger scales. We find that by applying the probability function at several time scales simultaneously each with an appropriate weight on determining the change of the sequence at any time step, we are able to generate monofractal sequences of quite a long length useful for any practical purpose.
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Marjan Uddin, University of engineering and technology Peshawar, Department of Basic Sciences, Pakistan
Abstract: In this work the method of approximate particular solutions using compactly supported kernels is investigated. In the work of [1] the global RBFs are used in the solution process, and the ill-conditioning of the resultant matrix is observed for solving large-scaled problems. We extended the work of [1] for compactly supported kernels, so that we can solve large-scaled problems in science and engineering. The numerical scheme of the present method of approximate particular solutions is simple to implement and very accurate. Three benchmark problems are solved by the present numerical scheme and the results are compared to other methods in the literature. ......................................................................................................................................................................................................................................................... [1] C. S. Chen, C. M. Fan, P. H. Wen. The Method of Approximate Particular Solutions for Solving Certain Partial Differential Equations, Published online 25 October 2010 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/num.20631.
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Tomasz Blachowicz, Silesian University of Technology, Institute of Physics - Center for Science and Education, Poland
Andrea Ehrmann, Niederrhein University of Applied Sciences, Faculty of Textile and Clothing Technology, Germany
Abstract: Magnetic nano-wire systems are, as well as other patterned magnetic structures, of special interest for novel applications, such as magnetic storage media [1]. In these systems, the coupling between neighboring magnetic units is most important for the magnetization reversal process of the complete system, leading to a variety of magnetization reversal mechanisms. While former simulations concentrated on iron nano-wires with different dimensions [2] and coupling mechanisms [3], this article examines the influence of the magnetic material on hysteresis loop shape, coercive field, and magnetization reversal modes. While nickel (Ni) nano-wire systems do not show special features which have not been found in simulations based on iron (Fe) nano-wires, systems consisting of cobalt (Co) nano-wires show hysteresis loops with several longitudinal steps and transverse peaks, correlated to a rich spectrum of magnetization reversal mechanisms. We show that changing the material parameters while the system geometry stays identical can lead to completely different hysteresis loops and reversal modes. Thus, especially for finding magnetic nano-systems which can be used as quaternary or even higher-order storage devices, it is very sensible to test several materials for the planned systems. Apparently, new materials may lead to novel and unexpected behavior – and can thus result in novel functionalities. [1] T. Blachowicz, A. Ehrmann: Fourfold nanosystems for quaternary storage devices, J. Appl. Phys. 110, 073911 (2011) [2] T. Blachowicz, A. Ehrmann, P. Steblinski, J. Palka: Directional-dependent coercivities and magnetization reversal mechanisms in fourfold ferromagnetic systems of varying sizes, J. Appl. Phys. 113, 013901 (2013) [3] T. Blachowicz and A. Ehrmann: Micromagnetic simulations of anisotropies in coupled and uncoupled ferromagnetic nano-wire systems, Sci World J 2013, 472597 (2013)
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Andrea Ehrmann, Niederrhein University of Applied Sciences, Faculty of Textile and Clothing Technology, Germany
Tomasz Blachowicz, Silesian University of Technology, Institute of Physics - Center for Science and Education, Poland
Hafed Zghidi, Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, Poland
Abstract: One of the techniques which can be used to quantitatively evaluate images statistically is the so-called random-walk approach, resulting in the calculation of the Hurst exponent, which is a measure of the complexity of the picture under examination. Especially long, fine elements in the image, such as fibers, influence the Hurst exponent significantly in comparison to a completely single-color picture. Thus, determination of the Hurst exponent has been suggested as new method to measure the hairiness of yarns [1] or knitted fabrics [2,3]. This is of special importance due to the fact that the existing hairiness measurement instruments are based on different measurement principles which are not necessarily comparable. While the principal usability of this method for hairiness detection has been shown in former projects, the absolute value of the calculated Hurst exponents is significantly dependent on the technique to take the photographic image of a sample, to transfer it into a monochrome picture, and on possible image processing steps. This article gives an overview of the influence of camera resolutions, edge detection filters, possible definitions of the limit color between black and white for the monochrome image, etc. It shows how these parameters should be chosen in case of typical textile samples and correlates the challenges of this novel method with well-known problems of common techniques to measure yarn and fabric hairiness. [1] T. Blachowicz, S. Aumann, B. Pruß, P. Reiners, A. Ehrmann, M. O. Weber, T. Weide: Optical determination of yarn hairiness using statistical methods, Proceedings of Aachen-Dresden International Textile Conference, Dresden / Germany, November 27-28, 2014 [2] T. Blachowicz, A. Ehrmann, M. Zieliński, M. O. Weber: Quantitative estimation of textile structural complexity using random walking approach, submitted [3] T. Blachowicz, A. Ehrmann, K. Domino, M. O. Weber: Examination of washing relaxation of knitted fabrics by random walking approach, submitted
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Derek Prates, Federal University of Jequitinhonha and Mucuri Valeys, Institute for Science, Engineering and Tecnology, Brazil
Caio Jardim, Universidade Federal dos Vales do Jequitinhonha e Mucuri, ICET, Brazil
Letícia Ferreira, Federal University of Jequitinhonha and Mucuri Valeys, Institute for Science, Engineering and Tecnology, Brazil
Jaqueline Silva, Federal University of Jequitinhonha and Mucuri Valeys, Institute for Science, Engineering and Tecnology, Brazil
Abstract: Mathematical models can be widely found in the literature for describing and analyzing epidemics. The models that use differential equations to represent mathematically such description are especially sensible to parameters involved in the modelling. In this work, an already developed model, called SIR, is analyzed when applied to a scenario of a dengue fever epidemic. Such choice is powered by the existence of useful tools presented by a variation of this original model, which allow an inclusion of different aspects of the dengue fever disease, as its seasonal characteristics, the presence of more than one strain of the vector and of the biological factor of cross-immunity. The analysis and results interpretation are performed through numerical solutions of the model in question, and a special attention is given to the different solutions generated by the use of different values for the parameters present in this model. Slight variations are performed either dynamically or statically in those parameters, mimicking hypothesized changes in the biological scenario of this simulation and providing a source of evaluation of how those changes would affect the outcomes of the epidemic in a population.
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Alfred Toms, University of Rome, Department of Physics, Italy
Jack Taylor, University of Rome, Department of Physics, Italy
Abstract: Test abstract
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M. M. Aish, Physics Department, Faculty of Science, Menoufia University, Egypt , Physics, Egypt
Abstract: The heterogeneity of plastic deformation of nickel single crystals in view of hierarchy of structural elements is investigated. The dependence of the structural elements forming the domain of deformation, on orientation of an axis of compression of single crystals is established. The deformation in domains and the structural elements is investigated.
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Felipe Loureiro, Federal university of Juiz de Fora, Computer Science, Brazil
Jonathan Silva, Federal University of Juiz de Fora, Brazil, Postgraduate Program in Computational Modeling, Brazil
Webe Mansur, Federal University of Rio de Janeiro,COPPE/UFRJ,RJ,Brazil, Department of Civil Engineering, Brazil
Abstract: Green's function based methodologies for elastodynamics in both time and frequency domains, which can be either numerical or analytical, appear in many branches of physics and engineering. Thus, the development of exact expressions for Green's functions is of great importance. Unfortunately, such expressions are known only for relatively few kinds of geometry, medium and boundary conditions. In this way, due to the difficulty in finding exact Green's functions, specially in the time domain, the present paper presents a solution of the transient elastodynamic equations by a time-stepping technique based on the Explicit Green's Approach method written in terms of the Green's and Step response functions, both being computed numerically by the finite element method. The major feature is the computation of these functions separately by the central difference time integration scheme and locally owing to the principle of causality. More precisely, Green's functions are computed only at $t=\Delta t$ adopting two time substeps while Step response functions are computed directly without substeps. The proposed time-stepping method shows to be quite accurate with distinct numerical properties not presented in the standard central difference scheme as addressed in the numerical example.
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Arijit Chowdhury, Tata Consultancy Services Ltd, Innovation Lab, India
Tapas Chakravarty, Tata Consultancy Services Ltd., Innovation Lab, India
Tanushree Banerjee, Tata Consultancy Services Ltd, Innovation Lab, India
P Balamuralidhar, Tata Consultancy Services Ltd, Innovation Lab, India
Abstract: The categorization of driving styles, particularly in terms of aggressiveness and skill is an emerging area of interest under the broader theme of intelligent transportation. There are two possible discriminatory techniques that can be applied for such categorization; a micro-scale (event based) model and a macro-scale (aggregate) model. It is believed that an aggregate model will reveal many interesting aspects of human-machine interaction; for example, we may be able to understand the propensities of individuals to carry out a given task over longer periods of time. A useful driver model may include the adaptive capability of the human driver, aggregated as the individual propensity to control speed/ acceleration. Towards that objective, we carried out experiments by deploying smartphone based application used for data collection by a group of drivers. Data is primarily being collected from GPS measurements including position & speed on a second-by-second basis, for a number of trips over a two months period. Analysing the data set, aggregate models for individual drivers were created and their natural aggressiveness were deduced. In this paper, we present the initial results for 12 drivers. It is shown that the higher order moments of the acceleration profile is an important parameter and identifier of journey quality. It is also observed that the Kurtosis of the acceleration profiles stores major information about the driving styles. Such an observation leads to two different ranking systems based on acceleration data. Such driving behaviour models can be integrated with vehicle and road model and used to generate behavioural model for real traffic scenario.
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Lok Lewyanvoon, The Citadel, School of Science and Mathematics, United States
Abstract: The method of invariant is used to derive effective Hamiltonians in the presence of strain and external fields for phosphorene. All the unknown parameters up to the appropriate order have been identified. The zero-field band structure is confirmed to be quadratic in the wave vector. The results for phosphorene are compared to graphene and silicene. In particular, we found that the band energies change quadratically with a perpendicular electric field but linearly with an external perpendicular magnetic field, whereas both behaviours are linear for silicene. The band structure and deformation potential parameters have been determined by fitting to density-functional theory calculations. Peculiarities related to the structural anisotropy of phosphorene are pointed out.
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Won-Kwang Park, Kookmin University, Mathematics, Korea, Republic of
Abstract: MUltiple SIgnal Classification (MUSIC) is a famous non-iterative detection algorithm in inverse scattering problems. If one knows the applied frequency, very accurate locations of small perfectly conducting cracks can be detected vis MUSIC. Unfortunately, when the applied frequency is unknown, inaccurate locations are identified via MUSIC with wrong frequency data. This fact has been confirmed via various results of numerical simulations; however, the reason behind this inaccurate identification has not been theoretically investigated. Motivated this fact, we identify the structure of MUSIC-type imaging functional with an unknown frequency by establishing a relationship with Bessel functions of order zero of the first kind. Various numerical experiments are performed, to support this analysis of the imaging functional.
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Leôncio Diógenes T. Câmara, Polytechnic Institute of State University of Rio de Janeiro (IPRJ-UERJ), Mechanical Engineering and Energy, DEMEC, Brazil
Abstract: The solvent-gradient simulated moving bed process (SG-SMB) is the new tendency in the performance improvement if compared to the traditional isocratic solvent conditions. In such SG-SMB separation process the modulation of the solvent strength leads to significant increase in the purities and productivity followed by reduction in the solvent consumption. A stepwise modeling approach was utilized in the representation of the interconnected chromatographic columns of the system combined with lumped mass transfer models between the solid and liquid phase. The influence of the solvent modifier was considered applying the Abel model which takes into account the effect of modifier volume fraction over the partition coefficient. The modeling and simulations were carried out and compared to the experimental SG-SMB separation of the amino acids phenylalanine and tryptophan. A lumped mass transfer kinetic model was applied for both the modifier (ethanol) as well as the solutes. The simulation results showed that such simple and global mass transfer models are enough to represent all the mass transfer effect between the solid adsorbent and the liquid phase. The separation performance can be improved reducing the interaction or the mass transfer kinetic effect between the solid adsorbent phase and the modifier. The simulations showed great agreement fitting the experimental data of the amino acids concentrations both at the extract as well as at the raffinate.
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Milan Zukovic, P.J. Safarik University in Kosice, Institute of Physics, Slovakia (Slovak Republic)
Dionissios Hristopulos, Technical University of Crete, School of Mineral Resources Engineering​, Greece
Abstract: We introduce a novel spatial prediction method inspired from statistical physics for efficient estimation of missing data with general non-Gaussian distributions on partially sampled Cartesian grids. The prediction model is based on a classical XY (also called planar rotator) spin model, which is modified in order to allow an appropriate one-to-one transformation between the data and spin values and which displays relevant short-range correlations at low temperatures. The spatial correlations present in the data are captured in terms of nearest-neighbor interactions between the spin variables. The only parameter of the present model is the reduced temperature, which is estimated from the sample-based correlations. Having inferred the temperature, conditional Monte Carlo simulations honoring the sample values are performed on the entire lattice to bring the system into thermal equilibrium and subsequently collect prediction statistics. Owing to the fact that the model does not show undesirable critical slowing down, the relaxation process is rather fast and, furthermore, the short-range nature of the interactions allows vectorization of the algorithm. Consequently, the proposed method achieves almost linear scaling with system size, thus being much more efficient than the conventional geostatistical approaches and applicable to huge datasets, such as satellite and radar images.
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pierre gaillard, Universié de Bourgogne, Mathématiques, France
Abstract: The solutions to the one dimensional focusing nonlinear Schrödinger equation (NLS) can be written as a product of an exponential depending on t by a quotient of two polynomials of degree N(N+1) in x and t. These solutions depend on 2N-2 parameters : when all these parameters are equal to 0, we obtain the famous Peregrine breathers which we call P_{N} breathers. Between all quasi-rational solutions of the rank N fixed by the condition that its absolute value tends to 1 at infinity and its highest maximum is located at the point ( x=0,t=0), the P_{N} breather is distinguished by the fact that P_{N}(0,0) = 2N+1. \\ We construct Peregrine breathers of the rank N explicitly for N less than 11. We give figures of these P_{N} breathers in the (x;t) plane; plots of the solutions P_{N}(0;t), P_{N}(x;0), never given for 6
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Vladimir Kahsurnikov, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Physics of the Solid State and Nanosystems, Russia
Anastasiia Maksimova, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Physics of the Solid State and Nanosystems, 0
Igor Rudnev, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Physics of the Solid State and Nanosystems, Russia
Abstract: The magnetization of layered high-temperature superconductors (HTSC) with ferromagnetic nanorods as bulk pinning centers is studied in the 2D model of layered HTSC by using Monte Carlo method. Magnetic part of the interaction energy between a ferromagnetic cylinder of arbitrary radius and fixed magnetization and an Abrikosov vortex was calculated in London approximation. The periodic and nonperiodic lattices of magnetic defects were considered. The vortex configurations arising during magnetization were obtained. The results of calculations were compared with the results for extended nonmagnetic defects.
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Vladimir Kahsurnikov, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Physics of the Solid State and Nanosystems, Russia
Andrey Krasavin, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Physical and Technical Problems of Metrology, Russia
Abstract: The generalized quantum Monte Carlo algorithm was used to obtain one-particle excitation spectrum and electron density of states for two-dimensional FeAs-clusters modeling iron-based superconductors within the limits of the full two-orbital model. The calculations were performed for clusters with sizes up to 10×10 FeAs-cells. The excitation spectra were reconstructed from Matsubara Green's function. The spectral density of states and the total density of states near the Fermi level were obtained. The data are in accordance with known experimental results. The influence of the cluster size, temperature, and the interaction strength on the density of states was analyzed.
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Aly Seadawy, Faculty of science, Taibah University, Mathematics, Saudi Arabia
Abstract: Solitary waves solutions are generated by deriving the nonlinear higher order of extended KdV equations for the free surface displacement. The problem formulations of models for internal solitary waves in a stratified shear flow with a free surface are presented. All coefficients of the nonlinear higher order extended KdV equation are expressed in terms of integrals of the modal function for the linear long-wave theory. The electric field potential and the fluid pressure in form traveling wave solutions of the extended KdV equation are obtained. The stability of the obtained solutions and the movement role of the waves by making the graphs of the exact solutions are discussed and analyzed.
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Ana Milena Nemocon, University Nacional de Colombia, Física, Colombia
Abstract: In contrast to other geophysical prospecting techniques, electroseismic is able to discriminate between different fluids such as water and hydrocarbons. In this technique, a mechanical wave is produced from an electromagnetic pulse applied on the earth sur- face, when it passes through the material acts differently on the adsorbed layer (Stern layer) and double layer induced in the fluid to saturate the soil (diffused layer). As a consequence, a relative displacement (solid-fluid) is produced and then, a seismic wave response can be detected using geophones. The equations governing the electroseismic effect combine Maxwell’s electrodynamics and Biot’s wave propagation in porous media, and are known as equations of Pride. In this work, we explore whether a finite differ- ence scheme in the natural domain of the problem, frequency, attain reproduce this phenomenon. The electromagnetic source is given by a Ricker wavelet with a central frequency equal to 20Hz. The numerical method consists in transforming to frequency the input pulse, discretize finite difference equations of Pride to solve with this scheme the answer to input pulse for each frequency, combine and translate the results into the time domain, and apply this to each depth of study. The scheme sheds acceleration data that reproduce the appearance of seismic waves induced by electroseismic effect on the interface of several distinct electrokinetic and poroelastic parameters of the underground, with velocities of the order of those expected for the medium. Meanwhile, the perturbation induced by the vertical propagation of the electromagnetic wave signal is attenuated, as expected, respect to characteristics of the soil. This work is a first step in Colombia in order to find numerical schemes that can reproduce this phenomenon correctly.
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Grigori Chapiro, Universidade Federal de Juiz de Fora, Mathematics, Brazil
Abstract: The paper is motivated by a model for the injection of air into a porous medium that contains a solid fuel, taking thermal losses into account [1]. This model was simplified in [2] by disregarding thermal losses and further studied using the singular perturbation technique. In [3] the model was further simplified and all wave sequences for the Riemann problem solution were obtained. Additionally, rigorous proof of the existence of the traveling wave solution was presented. The stability of such solutions was studied in [4]. Taking thermal losses into account is important from a physical point of view because they play an important role in laboratory experiments. In this work the first step in this direction is made. The model investigated in [3,4] is modified by including the thermal losses term, making it more physically realistic. In order to prove the existence of the traveling wave solution, we disregard diffusion effects and the dependence of gas density on temperature. Some numerical examples are presented to illustrate the model. [1] I.Y. Akkutlu and Y.C. Yortsos, The dynamics of in-situ combustion fronts in porous media, J. of Combustion and Flame, 134, pp. 229-247, 2003. [2] G. Chapiro, A. A. Mailybaev, A.J. Souza, D. Marchesin, and J. Bruining, Asymptotic approximation of long-time solution for low-temperature filtration combustion, Comput. Geosciences, 16, pp. 799-808, 2012. [3] G. Chapiro, D. Marchesin and S. Schecter, Combustion waves and Riemann solution in light porous foam, J. of Hyperbolic Differential Equations, v. 11, p. 295-328, 2014. [4] G. Chapiro, L. Furtado, D. Marchesin and S. Schecter, Stability of Interacting Traveling Waves in Reaction-Convection-Diffusion Systems, Accepted in Discrete and Continuous Dynamical Systems, 2015.
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Rémi Léandre, Université de Franche-Comté, Laboratoire de Mathématiques, France
Abstract: There are much more semi-groups than semi-groups which are represented by stochastic processes. On the other hand, there are a lot of formulas in stochastic analysis which are natural. The theory of pseudodifferential operators allow to understand a lot of partial differential equations, including parabolic equations. On the other hand we have imported in the theory of non-markovian semi-groups a lot of tools of stochastic analysis. Stochastic analysis formulas are valid for the whole process. Their interpretation for non-markovian semi-groups work only for the semi-group.
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Harold Zandvliet, MESA+ Institute for Nanotechnology & University of Twente, Applied Physics, Netherlands
Abstract: We have investigated the growth of Pt on Ge(110) using scanning tunneling microscopy and spectroscopy [1]. The deposition of several monolayers of Pt on Ge(110) followed by annealing at 1100 K results in the formation of three-dimensional eutectic GePt nanocrystals. Upon cooling down these eutectic GePt nanocrystals phase separate into pure Ge2Pt and Ge phases. The Ge segregrates towards the surface and forms a germanene layer. The germanene honeycomb lattice is composed of two hexagonal sub-lattices that are displaced vertically by 0.2 Å. The nearest-neighbor distance of the atoms in the honeycomb lattice is 2.5±0.1 Å, i.e. very close to the predicted nearest-neighbor distance in germanene. The differential conductivity (dI/dV) versus energy data reveals a V-shaped dependence with a non-zero minimum that is located just above the Fermi level.
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Hafida CHEMOURI, preparing school, chemistry, Algeria
Abstract: The Diels–Alder (DA) reaction is a powerful tool in organic synthesis and in the chemical industry. They allow, as private individuals, the formation (by bimolecular or intramolecular reaction) of a cycle with six atoms in a regioselective manner, while authorizing the presence of many functional groups. The lactonic cycle corresponds to a structural part is very frequently met in the natural products, in particular in sesquiterpenes which have for some of them, a multiple biological activity. In this work we studied, the Diels-Alder reaction involved a lactone derivative as a diene and a dienophile activated by a sulfoxyde groups both experimentally and theoretically. This type of sulfoxyde presents high stereo- and regioselectivity. our experimental finding schows that, the application of the reaction of Diels-Alder between a lactonic diene (standard B) and a dienophile (standard (A)) sufficiently reactive gives the product (C). In order to explain this experimental finding, theoretical investigation of the mechanism of the regio and stereoselectivity of this DA reaction has been carried out. The calculations have been performed in gas phase, in water solvent. The reaction mechanism corresponding to the formation of major isomers is elucidated by the analysis of the relevant stationary points of the potential energy surface and intrinsic reaction coordinate calculations. The obtained results put in evidence the importance of hydrogen bonding formed between the solvent molecules and the dienophile fragment in the acceleration of this DA reaction. The calculations are carried out with the Gaussian 09 suite of programs using the B3PW91 exchange-correlation functionals together with the 6–31G (d, p) basis set and the obtained results are in good agreement with experimental outcomes.
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