Papers by Emmanuel Kengne
Optical and Quantum Electronics
Nonlinear Dynamics
The dynamics of spatiotemporal modulated damped signals in a nonlinear LC transmission network wi... more The dynamics of spatiotemporal modulated damped signals in a nonlinear LC transmission network with dissipative elements are investigated analytically. The complex cubic Ginzburg–Landau (GL) equation governing slowly modulated wave propagation is presented. Considering linear wave propagating in the network, we derive in terms of the propagating frequency the spatial decreasing rate (linear dissipation parameter) and show that its must important contribution comes from the dissipative element of the shunt branch. The modulational instability (MI) criterion of modulated Stokes wave propagating in the network is investigated and the analytical expression of the MI growth rate is derived; we show that in the case of weak dissipation, there are no significant changes for the bandwidth frequency where the network may exhibit MI. Exact and approximative envelope soliton-like solutions of the derived GL equation are presented and used to investigate the dynamics of spatiotemporal modulated damped signals along the network. We show that the solution parameters can be used for managing the evolution of the envelope soliton signals along the network. Our investigation shows that the amplitude decays in both space (cell number n) and time t, while the velocity remains constant when the envelope soliton signal propagates along the dissipative network.
Abstract. We introduce a phase imprint into the order parameter describing the influence of blood... more Abstract. We introduce a phase imprint into the order parameter describing the influence of blood flow on the temperature distribution in the tissue described by the one-dimensional Pennes equation and then engineer the imprinted phase suitably to generate a modified Pennes equation with a gradient term (known in the theory of biological systems as convective term) which is associated with the heat convected by the flowing blood. Using the derived model, we analytically investigate temperature distribution in biological tissues subject to two different spatial heating methods. The applicability of our results is illustrated by one of typical bio-heat transfer problems which is often encountered in therapeutic treatment, cancer hyperthermia, laser surgery, thermal injury evaluation, etc. Analyzing the effect of the convective term on temperature distribution, we found that an optimum heating of a biological system can be obtained through regulating the convective term. 1
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Controlled thermal ablation in order to maximize the therapy and minimize the side effects poses ... more Controlled thermal ablation in order to maximize the therapy and minimize the side effects poses a challenge during the heating of the biological tissue. Traditionally, these processes are modelled by the bio heat equation introduced by Pennes, who used the Fourier’s theory of heat conduction. During my talk I will present our automated thermal dose control and prediction system for cancer tumors therapy by using Implantable Bio-chip solution. The proposed system is able to control thermal ablation doses deposition during a laser surgery/cancer treatment. A system would help physicians to predict thermal diffusion to organize the treatment as well as maximize therapeutic effects while minimizing side effects. An innovative approach is proposed to improve the quality of thermal treatments in oncology. A biochip platform will be investigated, designed, and prototyped on an FPGA board. The destruction of tumors using a heating source has been widely used as an efficient approach for ca...
Ukrainian Mathematical Journal, 2004
We consider the one-dimensional bio-heat transfer equation with quadratic temperature-depen-dent ... more We consider the one-dimensional bio-heat transfer equation with quadratic temperature-depen-dent blood perfusion, which governs the temperature distribution inside biological tissues. Using an extended mapping method with symbolic computation, we obtain the exact analytical thermal traveling wave solution, which describes the non-uniform temperature distribution inside the bodies. The found exact solution is used to investigate the temperature distribution in the tissues. It is found that the surrounding medium with higher temperature does not necessarily imply that the tissue will quickly (after a short duration of heating process) reach the desired temperature. It is also found that increased perfusion causes a decline in local temperature.
The first author, Emmanuel Kengne dedicates this work to the memory of their beloved son, Fred Ja... more The first author, Emmanuel Kengne dedicates this work to the memory of their beloved son, Fred Jake Sado To predict temperature distribution in a finite biological tissue simultaneously subjected to os-cillatory surface and spatial heating, we apply a nonlinear one-dimensional temperature-dependent blood perfusion bioheat Pennes transfer equation. Going from works of Jens Lang et al. in IEEE
Communications in Nonlinear Science and Numerical Simulation
This paper presents a new method for determining the exact number of inverters in one ring oscill... more This paper presents a new method for determining the exact number of inverters in one ring oscillator of temperature sensors that must be used optimally to monitor and control a complex system design. This method is very efficient, simple and easy to implement. The proposed temperature sensor was designed using TSMC 65 nm CMOS technology, which occupies an extremely small area of silicon. To deduce the exact number of inverters that form a single ring oscillator we will need to make simulations based on Computational Fluid Dynamics (CFD) which will allow us to measure the minimum and maximum temperature of the system used in order to intervene in case of overheating, also to monitor the state of the complex system design.
Chinese Journal of Physics, 2016
Abstract In this present paper, we investigate analytically the dynamics of modulated waves in a ... more Abstract In this present paper, we investigate analytically the dynamics of modulated waves in a dissipative nonlinear network with nonlinear dispersion. In the small amplitude limit, we use the reductive perturbation method and the continuum limit approximation to derive an envelope Ginzburg-Landau (GL) equation of the network. Considering modulated Stokes waves propagating in the network, we investigate their modulational instability (MI) and derive the analytical expression for the instability growth rate. We show that both the dissipative losses and the nonlinear dispersion constitute a great limiting factor to the experimental observation of the MI phenomenon. Investigating the transmission of modulated waves through the network, we show that the amplitude and the width of the solitonlike waves propagating in the network can be managed with the use of both the dissipative losses and the nonlinear dispersion of the network.
Chaos, Solitons & Fractals, 2015
A nonlinear network with many coupled nonlinear LC dispersive transmission lines is considered, e... more A nonlinear network with many coupled nonlinear LC dispersive transmission lines is considered, each line of the network containing a finite number of cells. In the semi-discrete limit, we apply the reductive perturbation method and show that the wave propagation along the network is governed by a two-dimensional nonlinear partial differential equation (2-D NPDE) of Schrodinger type. Two regimes of wave propagation, the high-frequency and the low-frequency are detected. By the means of exact soliton solution of the 2-D NPDE, we investigate analytically the soliton pulse propagation in the network. Our results show that the network under consideration supports the propagation of kink and dark solitons.
Journal of Mathematical Physics, 2008
An effective Gross-Pitaevskii equation, which describes the dynamics of quasi-one-dimensional Bos... more An effective Gross-Pitaevskii equation, which describes the dynamics of quasi-one-dimensional Bose-Einstein condensates in specific potential traps, is considered, and new families of exact solutions are reported, which include periodic and solitary waves. The solutions are applied to the description of BEC patterns trapped in optical-lattice potentials.
The European Physical Journal Plus
The dynamics of modulated waves in a nonlinear discrete transmission network with dissipative ele... more The dynamics of modulated waves in a nonlinear discrete transmission network with dissipative elements are investigated analytically. The generalized cubic-quintic Ginzburg-Landau (GCQ-GL) equation with intrapulse Raman scattering (IRS) terms governing spatially damped slowly modulated wave propagation is derived. Considering modulated Stokes wave propagating in the network, we investigate their baseband modulational instability (MI) and show that there are significant changes for the bandwidth frequency where the network may exhibit baseband MI. We show that the MI growth rate increases with the propagating frequency. The analytical chirped Lambert W-kink soliton-like solution of the derived GCQ-GL equation is presented and used to analyze the dissipative effects on chirped Lambert W-kink signals propagating through our network system. We show that the amplitude decreases both in space and time, while the width and the velocity remains constant when the Lambert W-kink signal propagates along the dissipative network. The effects of the cubic-Raman contributions on (i) the propagating frequency, (ii) the baseband MI, as well as (iii) the dynamics of Lambert W-kink signals are also investigated. In particular, our results reveal that a decrease in the cubic-Raman contributions enhances the baseband MI. The results of this paper may be useful for theoretical study of the propagation of ultrashort pulses in a single-mode optical fiber, as well as for experimental realization of undistorted transmission of optical pulses in optical fibers and further understanding their optical transmission properties.
Schrödinger Equations in Nonlinear Systems
In the present chapter, we study the generation of nonlinear modulated waves in one-dimensional r... more In the present chapter, we study the generation of nonlinear modulated waves in one-dimensional real electrical lattices. In the continuum limit, we use the semi-discrete approximation to show that the dynamics of modulated waves through the networks under considerations are governed by derivative equations of Schrödinger type including the generalized Chen-Lee-Liu equation and the cubicquintic derivative NLS equations. Through the analytical exact solutions of the derived network equations, we investigate the transmission of modulated pulses through the networks. The effects of linear dispersive element on the voltage signals are investigated. In the present chapter, we derive, for lines in Figs. 3.1 and 3.2, derivative NLS equation for the investigation of matter-wave solitons in these lines. For the network of Fig. 3.1, the second-neighbor interactions will be neglected; in other words, we work with the network of Fig. 3.1 under the condition that L 3 = ∞. 4.1 Generation of Nonlinear Modulated Waves in the Lossless Network of Fig. 3.1 In this section, we study the generation of nonlinear modulated waves in the lossless network of Fig. 3.1 when the second-neighbor interactions are neglected. Applying the reductive perturbation method in the semi-discrete approximation, we establish that the dynamics of modulated waves in this network is governed by a derivative NLS equation of the Chen-Lee-Liu (CLL) type (referred to as the generalized Chen-Lee-Liu (GCLL) equation). Then, we investigate the effects of the self-steepening on the modulation instabilities of Stokes waves. Through the obtained GCLL equation, we apply both the method of elliptic ordinary differential equation (EODE) and the Hirota bilinear operator method to investigate analytically the effects of the selfsteepening on the propagation of soliton-like wave signals in the network.
Schrödinger Equations in Nonlinear Systems, 2019
In this chapter, we use the multicomponent nonlinear Schrodinger equations to investigate the dyn... more In this chapter, we use the multicomponent nonlinear Schrodinger equations to investigate the dynamics of spin–orbit coupling (SOC) in Bose–Einstein condensates. We will study the rotating spin-1 BECs with anisotropic SOC, the spin texture of the vortex chain for rotating spin-1 BECs, the spin singularity phenomenon in the spin-1 BECs, the topological defects in the ground states of SU(3) SO-coupled BECs, and the inhomogeneous spin patterns in the spatially homogeneous spin-1 BECs. Also, we investigate here the configuration of Dirac monopoles with a polar-core vortex induced by the SO coupling in ferromagnetic BECs, as well as the non-Abelian Josephson effect in \(F=2\) spinor Bose–Einstein condensates with double optical traps.
To predict temperature distribution in a finite biological tissue simultaneously subjected to osc... more To predict temperature distribution in a finite biological tissue simultaneously subjected to oscillatory surface and spatial heating, we apply a nonlinear one-dimensional temperature-dependent blood perfusion bioheat Pennes transfer equation. Going from works of Jens Lang et al. in IEEE Trans. on Biomedical Engineering (1999) pp. 1129–138 and Tzu-Ching et al. in Medical Engineering & Physics 29 (2007) pp. 946–953, we investigate analytically and numerically the effect of various blood and heating parameters on the temperature distribution in muscle, tumor, fat, dermis, and subcutaneous tissues.
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Papers by Emmanuel Kengne