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Nonlinear continuous bi-inductance electrical line with dissipative elements:Dynamics of the low frequency modulated waves

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Chinese Physics B 2020年第4期29卷 179-189页

作者： s m Ngounou F B Pelap Unite de Recherche de mecanique et de modelisation des systèmes Physiques(UR-2 msP) Faculte des SciencesUniversite de DschangBP 69 DschangCameroun Unite de Recherche de matiere Condensee d'Electronique et de Traitement du signal(UR-mACETs) Faculte des SciencesUniversite de DschangBP 67 DschangCameroun

The dynamics of modulated waves in a nonlinear bi-inductance transmission line with dissipative elements are *** show the existence of two frequency modes and carry out intensive investigations on the low frequency *** to the multiple scales method,the behavior of these waves is investigated and the dissipative effects are *** appears that the dissipation coefficient increases with the carrier wave *** the continuous approximation,we derive that the propagation of these waves is governed by the complex Ginzburg-Landau equation instead of the Korteweg-de-Vries equation as previously *** studies of the dynamics of plane waves in the line reveal the existence of three additional regions in the dispersion curve where the modulational phenomenon is *** the low frequency mode,we demonstrate that the network allows the propagation of dark and bright *** findings are in perfect agreement with the analytical predictions.

关键词： dissipative bi-inductance network low frequency mode continuous approximation complex Ginzburg-Landau equation

Corrosion Behaviour of Nickel in Chloroacetic Acids and its Inhibition

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Journal of materials science & Technology 2004年第1期20卷 121-125页

作者： s.m.Rashwan A.Emam s.m.Abd El-Wahab m.m.mohamed Chemistry Department Faculty of Science Suez Canal University Ismailia EgyptChemistry Department Faculty of Science Suez Canal University Ismailia EgyptChemistry Department Faculty of Science Ain Shams University Cairo EgyptChemistry Department Faculty of Science Suez Canal University Ismailia Egypt

Anodic dissolution behaviour of Ni in mono-, di- and trichloroacetic acids has been investigated by measuring current densities of Ni electrode (versus sCE) at different potentials. Effects of acid concentration, pH, scan rate and additive inhibitor on the potential were studied and they revealed that there is a considerable shift of potential. Potentiodynamic polarization measurements show that the corrosion rate of Ni in chloroacetic acid solutions increases by increasing the previous factors. However, by adding inhibitor, it decreases.

关键词： Corrosion Nickel Chloroacetic acids Inhibition

Effect of inertial acoustic cavitation on antibiotic efficacy in biofilms

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Applied mathematics and mechanics(English Edition) 2021年第10期42卷 1397-1422页

作者： m.GHAsEmI s.sIVALOGANATHAN Department of Applied mathematics University WaterlooWaterloo N2L 3G1Canada

Bacterial biofilms can lead to chronic infections,increase tolerance to antibiotics and disinfectants,resistance to phagocytosis,and other components of the body’s immune *** formation is implicated in the persistence of staphylococcal infections and chronic Pseudomonas aeruginosa lung infections in cystic fibrosis(CF)patients(which can result from biofilm-growing mucoid strains).Conventional treatments utilize aggressive antibiotic prophylaxis/therapy to prevent/eliminate biofilms,followed by chronic suppressive ***,the use of enzymes to dissolve the biofilm matrix was investigated,in addition to quorum sensing inhibitors to increase biofilm susceptibility to ***,we propose a novel strategy,utilizing ultrasound-induced inertial cavitation,to increase antibiotic *** wall shear stress at the biofilm interface is calculated,and viscoplastic constitutive equations are used to examine the biofilm response to the mechanical *** simulations suggest that the maximum biofilm detachment occurs at high pressure/low frequency,and the mechanical disruption can affect the biochemical processes inside the biofilm resulting in vulnerability to antibiotics.

关键词： biofilm mechanical disruption mathematical model acoustic cavitation bubble collapse antibiotic

Dynamics of high-frequency modulated waves in a nonlinear dissipative continuous bi-inductance network

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Chinese Physics B 2021年第6期30卷 193-205页

作者： s m Ngounou F B Pelap Unitéde Recherche de mécanique et de modélisation des systèmes Physiques(UR-2 msP) Facultédes SciencesUniversitéde DschangBP 69 DschangCameroun Unitéde Recherche de matière Condensée d'Electronique et de Traitement du signal(UR-mACETs) Facultédes SciencesUniversitéde DschangBP 67 DschangCameroun

This paper presents intensive investigation of dynamics of high frequency nonlinear modulated excitations in a damped bimodal lattice. The effects of the dissipation are considered through a linear dissipation coefficient whose evolution in terms of the carrier wave frequency is checked. There appears that the dissipation coefficient increases with the carrier wave frequency. In the linear limit and for high frequency waves, study of the asymptotic behavior of plane waves reveals the existence of two additional regions in the dispersion curve where the modulational phenomenon is observed compared to the lossless line. Based on the multiple scales method exploited in the continuum approximation using an appropriate decoupling ansatz for the voltage of the two different cells, it appears that the motion of modulated waves is described by a dissipative complex Ginzburg–Landau equation instead of a Korteweg–de Vries equation. We also show that this amplitude wave equation admits envelope and hole solitons in the high frequency mode. From basic sources, we design a programmable electronic generator of complex signals with desired characteristics, which delivers signals exploited as input waves for all our numerical simulations. These simulations are performed in the LTspice software that uses realistic components and give the results that corroborate perfectly our analytical predictions.

关键词： dissipative bi-inductance network high-frequency mode continuous approximation dissipative complex Ginzburg–Landau equation programmable electronic generator LT-Pspice observations

Comprehensive investigation of stress intensity factors in rotating disks containing three-dimensional semi-elliptical cracks

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Applied mathematics and mechanics(English Edition) 2017年第11期38卷 1565-1578页

作者： m.FAKOOR s.m.N.GHOREIsHI Faculty of New sciences and Technologies University of Tehran Tehran 14395-1561 Iran

Initiation and propagation of cracks in rotating disks may cause catastrophic failures. Therefore, determination of fracture parameters under different working con- ditions is an essential issue. In this paper, a comprehensive study of stress intensity factors （sIFs） in rotating disks containing three-dimensional （3D） semi-elliptical cracks subjected to different working conditions is carried out. The effects of mechanical prop- erties, rotational velocity, and orientation of cracks on sIFs in rotating disks under cen- trifugal loading are investigated. Also, the effects of using composite patches to reduce sIFs in rotating disks are studied. The effects of patching design variables such as mechanical properties, thickness, and ply angle are investigated separately. The modeling and analytical procedure are verified in comparison with previously reported results in the literature.

关键词： stress intensity factor (sIF) semi-elliptical crack rotating disk finite ele-ment analysis (FEA)

Entanglement in a two-spin system with long-range interactions

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Chinese Physics B 2016年第8期25卷 369-372页

作者： soltani m R mahdavifar s mahmoudi m Department of Physics College of Science Yadegar-e-Imam Khomeini (RAH) Shahre-Rey Branch Islamic Azad University Department of Physics University of Guilan

The quantum entanglement between two spins in the Ising model with an added Dzyaloshinsky–moriya（Dm） interaction and in the presence of the transverse magnetic field is studied. The exchange interaction is considered as a function of the distance between spins. The negativity as a function of magnetic field, exchange and Dm interaction is *** effect of the distance between spins is studied based on the negativity. In addition, the effect of the thermal fluctuation on the negativity is also investigated.

关键词： entanglement Ising model Dm interaction negativity long range interaction

Compatibility of Fibreglass Woven Roving and Commercially Available Phenolic Resins

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Journal of materials science & Technology 1997年第5期13卷 379-382页

作者： Hayat, m.A. suliman, s.m.A. Dept. of mechanical Engineering Bahrain University Box 32038 Isa Town Bahrain

Three commercially available phenolic resins are assessed for compatibility with a fibreglass wovenroving reinforcement. Compatibility assessment is based on laminate physical properties f flexuralstrength and modulus in three and four point bending, interlaminar shear strength, and tensilestrength and modulus. The physical properties are also used for assessment of hand laminatedglass/phenolic systems

关键词： Glass fibers

Use of silica nanopowder to accelerate CO_2 sorption by Ca(OH)_2

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Particuology 2013年第4期11卷 448-453页

作者： m.A.s.Quintanilla J.m.Valverde Faculty of Physics University of SevilleAvenida Reina Mercedes s/n

Promising technologies have recently emerged to capture CO2 from postcombustion flue gas and to enhance the production of hydrogen from natural gas by steam-methane reforming, on the basis of sorp- tion of CO2 by Ca-based powders. The rate of CO2 sorption on Ca-based powders is limited by both carbonation kinetics and transport of CO2 to unreacted sorption sites. Ca-based powders may exhibit cohesive aggregation, thus hindering gas-solids contact efficiency. In our work, we tested the sorption rate of powder samples prepared by dry mixing of a cohesive Ca（OH）2 powder with a silica nanopowder used as additive. The silica nanopowder serves to improve the dispersibility of Ca（OH）2. Consequently, when a CO2 enriched gas and the modified sorbent are brought into contact, the rate of CO2 sorption is enhanced in the initial fast phase of interest for practical applications.

关键词： FluidizationFine powdersCO2 sorptionNanoparticles

Hidden periodicity in stripe 82 with saraswati supercluster—a fractal analysis

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Communications in Theoretical Physics 2021年第1期73卷 71-77页

作者： Vimal Raj m s swapna s sankararaman Department of Optoelectronics University of KeralaTrivandrumKerala695581-India

The manuscript attempts to explore the periodicity in the distribution of galaxies in the recently reported saraswati supercluster and the stripe 82 region containing it as an *** report of 120 mpc periodicity in the Abell galaxy clusters by power spectrum analysis is the motivation behind the *** power spectral analysis across the central part of the stripe 82 region shows a periodic variation of 3.09°or 71 mpc in fractal dimension whereas an average angular periodicity of 3.45°or 94 mpc is observed across the stripe 82 *** refers to the periodicity of complexity or cluster density of galaxy *** texture of the distribution pattern understood through lacunarity analysis indicates a near symmetric *** dimensions like box-counting dimension,information dimension and correlation dimension are also found through multifractal *** the information dimension tells about the distribution density of galactic points,the correlation dimension details the distribution of galaxies in the neighbourhood.

关键词： galaxy distribution fractal analysis multifractals lacunarity saraswati supercluster stripe 82