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NH_3 Plasma Surface Treatments of Engineering Fluoropolymers: A Way to Enhance Adhesion of Ni or Cu Thin Films Deposited by Electroless Plating

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材料热处理学报 2004年第05B期25卷 1092-1097页

作者： Maurice Romand Marlene Charbonnier Yves Goepfert laboratoire de Sciences et Ingenierie des Surfaces and Laboratoire de Sciences et Ingenierie des Surfaces andUMR 5180 des Sciences Analytiques Universite Claude Bernard - Lyon 1 69622 Villeurbanne Cedex France

This paper describes the electroless Ni or Cu plating of some fiuoropolymer substrates through a tin-free activation process. Materials subjected to surface metallization are commercial Teflon() FEP, Nafion(), ACLAR() and LaRCTM-CP1 thin films which have recently gained a large scientific and technological interest due to their excellent thermal, chemical, mechanical and dielectric properties. The original approach implemented in the present work involves: (i)the grafting of nitrogen-containing functionalities on the polymer surfaces through plasma treatments in ammonia, (ii) the direct catalysis of the so-modified surfaces via their immersion in a simple acidic PdCl2 solution (i.e. without using a prior surface sensitization in an acidic SnCl2 solution), and finally (iii) the electroless metallization itself. However, prior to the immersion in the industrial plating baths, the chemical reduction of the Pd+2 species (species covalently tethered on the nitrogen-containing groups) to metallic palladium (PdO) is shown to be a key factor in catalyzing the electroless deposition initiation. This is made by immersion in an hypophosphite (H2PO2-) solution. Wettability measurements and X-ray photoelectron spectroscopy (XPS) experiments are used to characterize every surface modification step of the developed process. A cross-hatch tape test was used to asses the adhesion strength of the electroless films that is shown qualitatively good. In addition, a fragmentation test was developed in combination with electrical measurements. Its use allows to distinguish different adhesion levels at the metal/polymer interface and to evidence the influence of some processing parameters.

关键词：镍化学镀层铜化学镀层等离子表面处理表面催化 XPS 剥离试验

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Detection of CO2 and O2 by iron loaded LTL zeolite films

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Frontiers of Chemical Science and Engineering 2018年第1期12卷 94-102页

作者： Veselina Georgieva Richard Retoux Valerie Ruaux Valentin Valtchev Svetlana Mintova laboratoire Catalyse et Spectrochimie (LCS) ENSICAEN CNRS Normandy University 14000 Caen France laboratoire de Cristallographie et Sciences des Matériaux (CRISMAT) ENSICAEN CNRS Normandy University 14000 Caen France

Detection of oxygen and carbon dioxide is important in the field of chemical and biosensors for atmosphere and biosystem monitoring and fermentation processes. The present study reports on the preparation of zeolite films doped with iron nanoparticles for detection of CO2 and O2 in gas phase. Pure nanosized LTL type zeolite with monomodal particle size distribution loaded with iron （Fe-LTL） was prepared under hydrothermal condition from colloidal precursor suspensions. The zeolite was loaded with iron to different levels by ion exchange. The Fe-LTL suspensions were used for preparation of thin films on silicon wafers via spin coating method. The reduction of the iron in the zeolite films was carried out under H2 flow （50% H2 in Ar） at 300 ℃. The presence of iron nanoparticles is proved by in situ ultra-violet-visible spectroscopy. The properties of the films including surface roughness, thickness, porosity, and mechanical stability were studied. In addition, the loading and distribution of iron in the zeolite films were investigated. The Fe-LTL zeolite films were used to detect O2 and CO2 in a concentration dependent mode, followed by IR spectroscopy. The changes in the IR bands at 855 and 642 cm^-1 （Fe O-H and Fe-O bending vibrations） and at 2363 and 2333 cm^-1 （CO2 asymmetric stretching） corresponding to the presence of O2 and CO2, respectively, were evaluated. The response to O2 and CO2 was instant, which was attributed to great accessibility of the iron in the nanosized zeolite crystals. The saturation of the Fe-LTL films with CO2 and O2 at each concentration was reached within less than a minute. The Fe-LTL films detected both oxygen and carbon dioxide in contrast, to the pure LTL zeolite film.

关键词： zeolite films detection of CO2 and O2 adsorption

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First-principles study of the new potential photovoltaic absorber:Cu_2MgSnS_4 compound

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Chinese Physics B 2017年第7期26卷 294-304页

作者： Belmorsli Bekki Kadda Amara Mohammed El Keurti laboratoire d'étude physico-chimique Université Dr.Moulay Tahar de Saida

The structural, electronic, optical, and elastic properties of Cu_2MgSnS_4 in four crystalline phases（wurtzite-stannite（WS）, stannite（ST）, kesterite（KS）, and primitive-mixed Cu Au（PMCA）） are investigated using density functional theory（DFT） in the framework of the full potential linearized augmented plane wave plus local-orbitals（FP-LAPW＋lo） method within the generalized gradient approximation based on the Perdew 2008 functional（GGA-PBEsol）. For each phase, the structural parameters, bulk modulus, and its pressure derivative are calculated. The relative stability of these phases is also discussed. In addition, the elastic constants have been calculated in order to investigate the mechanical stability of all phases. Moreover, the anisotropy factor, shear modulus, Young＇s modulus, Lame＇s coefficient, and Poisson＇s ratio have been estimated from the calculated single crystalline elastic constants. For the band structure, the density of states and optical properties of the exchange and correlation effects are treated by the Tran-Blaha modified Becke-Johnson potential to give a better description of the band-gap energies and optical spectra. The obtained results are compared with available experimental data and to other theoretical calculations.

关键词： quaternary chalcogenide semiconductor elastic constants electronic properties optical properties

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Optimal Control of a Frictional Contact Problem

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Acta Mathematicae Applicatae Sinica 2015年第4期31卷 991-1000页

作者： Arezki TOUZALINE laboratoire de Systèmes Dynamiques Faculté de MathématiquesUSTHB

We consider a mathematical model which describes a contact between a deformable body and a foundation. The contact is bilateral and modelled with Tresca＇s friction law. The goal of this paper is to study an optimal control problem which consists of leading the stress tensor as close as possible to a given target, by acting with a control on the boundary of the body. We state an optimal control problem which admits at least one solution. We also introduce the regularized control problem for which we study the convergence when the regularization parameter tends to zero. Finally, an optimally condition is established for this problem.

关键词： optimal control of variational inequalities elastic materials Tresca's friction, weak solution

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Viscous Modified Chaplygin Gas in Classical and Loop Quantum Cosmology

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Chinese Physics Letters 2017年第6期34卷 139-143页

作者： D. Aberkane N. Mebarki S. Benchikh laboratoire de Physique Mathematique et Subatomique Mentouri University Constantine 25000 Algeria

We investigate the cosmological model of viscous modified Chaplygin gas （VMCG） in classical and loop quantum cosmology （LQC）. Firstly, we constrain its equation of state parameters in the framework of standard cosmology from Union 2.1 SNe Ia data. Then, we probe the dynamical stability of this model in a universe filled with VMCG and baryonic fluid in LQC background. It is found that the model is very suitable with （χ2/d.o.f = 0.974） and gives a good prediction of the current values of the deceleration parameter q0 =∈ （-0.60, -0.57） and the effective state parameter ωeff∈ （-0.76, -0.74） that is consistent with the recent observational data. The model can also predict the time crossing when （ρDE ≈ Pmatter） at z = 0.75 and can solve the coincidence problem. In LQC background, the Big Bang singularity found in classical cosmology ceases to exist and is replaced by a bounce when the Hubble parameter vanishes at ρtot≈ρc.

关键词： Viscous Modified Chaplygin Gas in Classical and Loop Quantum Cosmology

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MODELING AND OPTIMIZATION OF CYCLIC HOIST SCHEDULES IN AN ELECTROPLATING LINE

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Journal of Systems Science and Systems Engineering 2016年第4期25卷 469-490页

作者： Ahmed Nait-Sidi-Moh Adnen EI-Amraoui Universite de Picardie Jules Verne Laboratoire des Technologies lnnovantes 02100 ST Quentin France Universite d'Orleans Laboratoire PRISME 63 av. de Lattre de Tassigny 18020 Bourges France

This paper deals with the modeling, analysis and optimization of a specific kind of real industrial problems. This class of problems is known in the literature as Cyclic Hoist Scheduling Problem （CHSP）. In such class of problems, several jobs have to flow through a production line according to an ordered bath sequence. The CHSPs appear in the manufacturing facilities to achieve a mass production and to search a repetitive sequence of moves for the hoist. In this paper, we develop P-Temporal Petri Net models to represent the behavior and validate certain qualitative properties of the basic production line. Afterward, complex configurations of the production line are modeled and their properties such as reachability of desired functioning （cyclic operation）, deadlock-free, resource sharing and management are checked and validated. A mathematical analysis and a simulation study of all proposed Petri net models are carried out using mathematical fundaments of Petri nets and a Visual Object Net ＋＋ tool. The second part of the paper deals with the development of a mixed integer linear programming models to optimize processing of each line configuration. Optimal manufacturing plans of the studied system with cyclic processing sequences are defined and the feasibility of optimal cyclic scheduling of each configuration is proved.

关键词： Manufacturing lines processing tanks cyclic scheduling Petri nets mixed integer linear programming modeling optimization

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Surface morphology and electrochemical characterization of electrodeposited Ni-Mo nanocomposites as cathodes for hydrogen evolution

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Chinese Physics B 2015年第10期24卷 559-563页

作者： Elhachmi Guettaf Temam Hachemi Ben Temam Said Benramache laboratoire de Physique des Couches Minces et Applications Université de Biskra

In this work, we study the influences of current density on surface morphology and electrochemical characterization of electrodeposited Ni-Mo. The Ni-Mo composite coatings are deposited on pretreated copper substrates by electrolytic deposition. The Ni-Mo solution is taken from nickel sulfate fluid and ammonium heptamolybdate with 10 g/l. The Ni-Mo composite coatings are deposited at a temperature of 303 K with an applied current density of j dep= 10 A/dm2-30 A/*** find that the corrosion resistance is improved by incorporating Mo particles into Ni matrix in 0.6-M Na Cl solution. From the potentiodynamic polarization curve of electrodeposited Ni-Mo it is confirmed that the corrosion resistance decreases with increasing applied current density. The x-ray diffraction（XRD） analyses of Ni-Mo coatings indicate three phases of Mo Ni4, Mo1.24Ni0.76, and Ni3 Mo phases crystallites of nickel and molybdenum. The scanning electronic microscopy（SEM） tests indicate that Ni-Mo coatings present cracks and pores.

关键词： Ni-Mo electrolytic deposition corrosion resistance potentiodynamic polarization plating current density

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Anaerobic Removal of Trace Organic Contaminants in Sewage Sludge: 15 Years of Experience

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Pedosphere 2012年第4期22卷 508-517页

作者： M. BARRET L. DELGADILLO-MIRQUEZ E. TRABLY N. DELGENES F. BRAUN G. CEA-BARCIA J. P. STEYER D. PATUREAU INRA UR0050 Laboratoire de Biotechnologie de l'Environnement

Trace organic contaminants (TOCs) correspond to a broad range of molecules generated either directly or indirectly by human activity. Even though TOCs are found at low concentrations in the environment, they often accumulate by biomagnification and bioaccumulation into biological organisms and cause irreversible damages in biological systems through direct or indirect toxic effects such as endocrine disruption and tumour initiation. This manuscript presents the main findings of over fifteen years of research focusing on biological removal of various TOCs found in sewage sludge from urban treatment plants. A special focus of the research was made on microbial processes in complex anaerobic ecosystems. Four families of compounds mostly retrieved in urban plants were studied: the polycyclic aromatic hydrocarbons (PAHs), the polychlorobiphenyls (PCBs), the phthalic acid esters (PAEs), and the nonylphenol ethoxylates (NPEs). It was observed that the microbial capability for removing low amounts of TOCs required a long adaptation time and was often limited by the bioavailability of these compounds. In fact, the overall biodegradation resulted from the numerous interactions existing between the matrix (organic matter) and the microbial ecosystems according to the physico-chemical sorption properties of these compounds. Mechanistic aspects were also tackled in depth and specific models were developed for better understanding the network of interactions between TOCs, microorganisms, and organic matter. These findings could be extrapolated to other ecosystems such as soils and sediments. Finally, it was shown that microbial cometabolism was essential for TOC removal, and the concept of bioavailability was not only dependent on the nature, the level, and the sorption properties of TOCs but was also strongly dependent on the nature and the concentration of the sludge organic matter. Specific parameters were proposed for better evaluating the fate of TOCs in microbial anaerobic

关键词： anaerobic digestion bioavailability biodegradation microbial cometabolism organic matter

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Performance of PI controller for control of active and reactive power in DFIG operating in a grid-connected variable speed wind energy conversion system

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Frontiers in Energy 2014年第3期8卷 371-378页

作者： Azzouz TAMAARAT Abdelhamid BENAKCHA laboratoire LGEB Biskra University Biskra City 07000 Algeria

Due to several factors, wind energy becomes an essential type of electricity generation. The share of this type of energy in the network is becoming increasingly important. The objective of this work is to present the modeling and control strategy of a grid connected wind power generation scheme using a doubly fed induction generator （DFIG） driven by the rotor. This paper is to present the complete modeling and simulation of a wind turbine driven DFIG in the second mode of operating （the wind turbine pitch control is deactivated）. It will introduce the vector control, which makes it possible to control independently the active and reactive power exchanged between the stator of the generator and the grid, based on vector control concept （with stator flux or voltage orientation） with classical PI controllers. Various simula- tion tests are conducted to observe the system behavior and evaluate the performance of the control for some optimization criteria （energy efficiency and the robustness of the control）. It is also interesting to play on the quality of electric power by controlling the reactive power exchanged with the grid, which will facilitate making a local correction of power factor.

关键词： wind power doubly fed induction generator(DFIG) vector control active power reactive power,maximum power point tracking (MPPT)

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Unified treatment of the bound states of the Schioberg and the Eckart potentials using Feynman path integral approach

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Chinese Physics B 2015年第2期24卷 39-45页

作者： A.Diaf laboratoire de l'nergie et des Systemes Intelligents Université de Khemis Miliana

We obtain analytical expressions for the energy eigenvalues of both the Schioberg and Eckart potentials using an approximation of the centrifugal term. In order to determine the l-states solutions, we use the Feynman path integral approach to quantum mechanics. We show that by performing nonlinear space-time transformations in the radial path integral, we can derive a transformation formula that relates the original path integral to the Green function of a new quantum solvable system. The explicit expression of bound state energy is obtained and the associated eigenfunctions are given in terms of hypergeometric functions. We show that the Eckart potential can be derived from the Schioberg potential. The obtained results are compared to those produced by other methods and are found to be consistent.

关键词： path integrals l-states Schioberg potential Eckart potential

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