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31.
Salim A. Messaoudi Belkacem Said‐Houari 《Mathematical Methods in the Applied Sciences》2005,28(2):205-232
In this paper, we consider a one‐dimensional non‐linear system of thermoelasticity with second sound. We establish an exponential decay result for solutions with small ‘enough’ initial data. This work extends the result of Racke (Math. Methods Appl. Sci. 2002; 25 :409–441) to a more general situation. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
32.
Belkacem Otazaghine Cyrille Boyer Jean‐Jacques Robin Bernard Boutevin 《Journal of polymer science. Part A, Polymer chemistry》2005,43(11):2377-2394
Different acrylate oligomers were synthesized by atom transfer radical polymerization in the presence of a transfer agent and CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine. The functionality in bromine was determined by 1H NMR. These oligomers were coupled in the presence of Cu(0) and the ligand 2,2′‐bipyridine. The coupling yield was determined by size exclusion chromatography and NMR analysis and depended on the nature of the monomer and not on the molecular weight. In other words, the preliminary functionalization of the brominated chain end with styrene increased the coupling yield. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2377‐2394, 2005 相似文献
33.
Faiza Nessark Ahmed Zouaoui Alvaro Garcia-Cruz Anne Bonhomme Michael Lee Belkacem Nessark 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(11):827-834
In this research, an efficient fabrication process of conducting polypyrrole (PPy)/silicon nitride (Si3N4) hybrid materials were developed in order to be employed as transducers in electrochemical sensors used in various environmental and biomedical applications. The fabrication process was assisted by oxidative polymerization of pyrrole (Py) monomer on the surface of Si/SiO2/Si3N4 substrate in presence of FeCl3 as oxidant. To improve the adhesion of PPy layer to Si3N4 surface, a pyrrole-silane (SPy) was chemically bonded through silanization process onto the Si3N4 surface before deposition of PPy layer. After Py polymerization, Si/SiO2/Si3N4-(SPy-PPy) substrate was formed. The influence of SPy concentration and temperature of silanization process on chemical composition and surface morphology of the prepared Si/SiO2/Si3N4-(SPy-PPy) substrates was studied by FTIR and SEM. In addition, the electrical properties of the prepared substrates were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that the best silanization reaction conditions to get Si/SiO2/Si3N4-(SPy-PPy) substrate with high PPy adhesion and good electrical conductivity were obtained by using SPy at low concentration (4.3 mM) at 90°C. These promising findings open the way for fabrication of new hybrid materials which can be used as transducers in miniaturized sensing devices for various environmental and biomedical applications. 相似文献
34.
Belkacem Chaouchi Rabah Labbas Boubaker-Khaled Sadallah 《Mediterranean Journal of Mathematics》2013,10(1):157-175
In this paper, we give new results about existence, uniqueness and regularity properties for solutions of Laplace equation $$\Delta u = h \quad {\rm in} \, \Omega$$ where Ω is a cusp domain. We impose nonhomogeneous Dirichlet conditions on some part of ?Ω. The second member h will be taken in the little Hölder space ${h^{2 \sigma}(\bar{\Omega})}$ with ${\sigma \, \in \, ]0, \, 1/2[}$ . Our approach is based essentially on the study of an abstract elliptic differential equation set in an unbounded domain. We will use the continuous interpolation spaces and the generalized analytic semigroup theory. 相似文献
35.
Belkacem Said-Houari 《Applicable analysis》2013,92(3):475-489
This work is concerned with a system of two wave equations with nonlinear damping and source terms acting in both equations. Under some restrictions on the nonlinearity of the damping and the source terms, we show that our problem has a unique local solution. Also, we prove that, for some restrictions on the initial data, the rate of decay of the total energy is exponential or polynomial depending on the exponents of the damping terms in both equations. 相似文献
36.
37.
Abdellah Aziz El Hadj Elandaloussi Belkacem Belhalfaoui Mohand Said Ouali Louis Charles De Mnorval 《Colloids and surfaces. B, Biointerfaces》2009,73(2):192-198
Chemical functionalization of olive stone wastes with succinate linkers can potentially improve the performance of wastewater treatment technologies via enhanced adsorption and high affinity of the covalently attached succinate groups for heavy metals. In this study, a novel reusable adsorbent material based on agricultural waste has been synthesized by esterifying the lignocellulosic matrix of olive stones with succinic anhydride in toluene under basic conditions. Characterization of the as-prepared material by FTIR and solid-state MAS 13C NMR spectroscopies and TGA confirmed that the heterogeneous esterification has proceeded very efficiently to yield the succinylated-olive stone (S–OS). Subsequent alkaline treatment of S–OS with saturated NaHCO3 aqueous solution led to the resulting sodic material (NaS–OS), which was subjected to batch experiments in order to evaluate its cadmium-removing efficiency from aqueous solutions at realistic concentrations of cadmium found in industrial effluents. The results obtained from the sorption characteristics have revealed that NaS–OS material is highly effective in removing cadmium from aqueous solutions, with a maximum uptake capacity of 200 mg g−1 (1.78 mmol g−1). The Langmuir isotherm model was found to fit adequately the equilibrium isotherm data. Cadmium adsorption occurs rapidly and the adsorption mechanism is a chemical sorption via ionic exchange between the adsorbate and adsorbent. Thermodynamic parameters were also evaluated from the effect of temperature studies. Regenerability of NaS–OS material was ascertained by quantitative desorption of cadmium with 1 M aqueous NaCl and the reusability of the matrix after five repeated cycles led to nearly no attenuation in its performance (less than 2% in the sorption capacity), indicating that repeated use of NaS–OS is quite feasible. Compared to other low-cost adsorbents utilized for the removal of Cd(II) from water/wastewater, NaS–OS shows higher sorption capacity. These results have important implications for the design of low-cost adsorbents based on agricultural wastes. 相似文献
38.
Med Habib Oueslati Jalloul Bouajila Med Amine Belkacem Abdel Halim Harrath Saleh H. Alwasel Hichem Ben Jannet 《Natural product research》2019,33(5):708-714
Two new monoterpene Ducrosin A (1) and sesquiterpene Ducrosin B (2) were isolated along with three known compounds, stigmasterol (3) and two furanocoumarins (4 and 5), from the dichloromethane extract of the seeds of Ducrosia anethifolia (DC.) Boiss. Their structures were determined using extensive 1D and 2D NMR, (ES)-HRMS and IR spectroscopic analyses and by comparison with literature data. Gas chromatography analysis of the fatty acids (FAs) of D. anethifolia seed oils (DAOs) showed high percentages of elaidic acid (C18:1 Δ9t) 65% and oleic acid (C18:1 Δ9c) 15%. The total tocopherol (tocols) content in DAOs was found to be 164 mg/100 g. The cytotoxic effect of the isolates was also evaluated using the MTT assay against the HCT-116 and SKOV-3 cell lines. The results showed that compound 2 was the most cytotoxic agent followed by compounds 1 and 4, which has an epoxide moiety that most likely contributes to its activity. 相似文献
39.
Talbi L. Berouaken M. Khaldi K. Keffous A. Gabouze N. Trari M. Menari H. Belkacem Y. 《Journal of Solid State Electrochemistry》2018,22(4):1123-1130
Journal of Solid State Electrochemistry - In this work, we have elaborated and characterized polyaniline (PANI) thin films doped with sulfuric acid (H2SO4) using cyclic voltammetry (CV). The PANI... 相似文献
40.
Dynamics of ionization mechanisms in relativistic collisions involving heavy and highly-charged ions
D.C. Ionescu A. Belkacem 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(3):301-307
The dynamics of mechanisms associated with the ionization of inner-shell electrons in relativistic collisions involving heavy
and highly-charged ions is investigated within a nonperturbative approach formulated explicitly in the time domain. The theoretical
treatment is based on the exact numerical solution of the time dependent Dirac equation for two Coulomb centers on a lattice
in momentum space. We present results for ionization in encounters between 100 MeV/u Au79+ projectile ions impinging on a hydrogen-like uranium target. By directly visualizing the collision dynamics we identify a
new ionization mechanism in which electrons are emitted from the internuclear region preferentially in the transverse direction
with respect to the projectile trajectory. A striking characteristic of this ionization mechanism is that the velocity of
the electron is higher than the projectile velocity.
Received 26 June 2001 and Received in final form 27 November 2001 相似文献