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Brahim ABBOU Imane LEBKIRI Hanae OUADDARI Lamya KADIRI Abdelkarim OUASS Amar HABSAOUI Ahmed LEBKIRI El Housseine RIFI 《Turkish Journal of Chemistry》2021,45(2):362
In this work, we study the elimination of three bivalent metal ions (Cd2+, Cu2+, and Pb2+) by adsorption onto natural illitic clay (AM) collected from Marrakech region in Morocco. The characterization of the adsorbent was carried out by X-ray fluorescence, Fourier transform infrared spectroscopy and X-ray diffraction. The influence of physicochemical parameters on the clay adsorption capacity for ions Cd2+, Cu2+, and Pb2+, namely the adsorbent dose, the contact time, the initial pH imposed on the aqueous solution, the initial concentration of the metal solution and the temperature, was studied. The adsorption process is evaluated by different kinetic models such as the pseudo-first-order, pseudo-second-order, and Elovich. The adsorption mechanism was determined by the use of adsorption isotherms such as Langmuir, Freundlich, and Temkin models. Experiments have shown that heavy metals adsorption kinetics onto clay follows the same order, the pseudo-second order. The isotherms of adsorption of metal cations by AM clay are satisfactorily described by the Langmuir model and the maximum adsorption capacities obtained from the natural clay, using the Langmuir isotherm model equation, are 5.25, 13.41, and 15.90 mg/g, respectively for Cd(II), Cu(II), and Pb(II) ions. Adsorption of heavy metals on clay is a spontaneous and endothermic process characterized by a disorder of the medium. The values of ΔH are greater than 40 kJ/mol, which means that the interactions between clay and heavy metals are chemical in nature. 相似文献
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Lgaz Hassane Chaouiki Abdelkarim Albayati Mustafa R. Salghi Rachid El Aoufir Yasmina Ali Ismat H. Khan Mohammad I. Mohamed Shaaban K. Chung Ill-Min 《Research on Chemical Intermediates》2019,45(4):2269-2286
Research on Chemical Intermediates - Mild steel corrosion in HCl solution is an example of corrosion in acidic mediums. The ongoing research efforts to develop novel environmentally friendly... 相似文献
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Murielle Keller Dr. Abdelkarim Sani Souna Sido Patrick Pale Prof. Dr. Jean Sommer Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2810-2817
Clicking in zeolites : Copper(I)‐exchanged zeolites proved to be practical and efficient catalysts for the cycloaddition of azomethine imines with alkynes, providing a convenient access to N,N‐bicyclic pyrazolidinone derivatives (see scheme). With high regioselectivity, 100 % atom economy, and convenient product isolation, this heterogeneously catalyzed version of the Dorn cycloaddition corresponds to click‐chemistry criteria.
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Abdelkarim Sani Souna Sido Stefan Chassaing Patrick Pale Jean Sommer 《Tetrahedron letters》2007,48(33):5911-5914
Depending on the reaction conditions, arylvinylketones can be directly and efficiently converted using zeolites to indanones by cyclization or to dihydrochalcones through regioselective aryl addition or chemoselective hydride transfer. 相似文献
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The conformational properties of some N-alkyl, N,N′-dialky, and tetraalkyloxalamides have been investigated, in vacuo and in solvent using DFT methods at the B3LYP/6-31G∗∗ computational level. Special emphasis has been given on oxalamides with substituents of the type -CH2CH2OH. In oxalamides with the N-H group (N-alkyl and N,N′-dialky), the most stable conformations are those in which the oxalamide moiety adopts a planar s-trans arrangement and the amide bonds are trans. A different situation appears in the case of tetraalkyloxalamides, in which the oxalamide moiety always adopts a skewed arrangement and there are conformations with similar energy. A careful study of 13C and 1H NMR spectra together with theoretical calculations (GIAO method) allowed the assignment of the signals of these conformers. The presence of the -CH2CH2OH chain produces numerous rotamers. The most stable rotamers, in vacuo, are those with strong intramolecular hydrogen bonds, however in solvent, hydrogen bonds are not crucial to establish the most stable specie and depend on the solvent used. 相似文献
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The control problem of axially moving strings occurs in a large class of mechanical systems. In addition to the longitudinal displacement, the strings are subject to undesirable transversal vibrations. In this work, in order to suppress these vibrations, we consider a control by a hydraulic touch-roll actuator at the right boundary. We prove uniform stability of the system using a viscoelastic material and an appropriate boundary control force applied to the touch rolls of the actuator. The features of the present work are: taking into account the mass flow entering in and out at the boundaries due to the axial movement of the string and overcoming the difficulty raised by the Kirchhoff coefficient which does not allow us to profit from the dissipativity of the system (as in the existing works so far). We shall make use of an inequality which is new in this theory. 相似文献
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Rushdi M. -L. Kitaneh Abdelkarim M. Saleh Robert D. Gould 《Central European Journal of Physics》2006,4(1):87-104
The ac electrical parameters of thermally evaporated zinc phthalocyanine, ZnPc, semiconducting thin films was measured in
the temperature range of 180–390 K and frequency between 0.1 and 20 kHz. Aluminum electrode contacts were utilized to sandwich
the organic ZnPc semiconducting films. Capacitance and loss tangent decreased rapidly with frequency at high temperatures,
but at lower temperatures a weak variation is observed. An equivalent circuit model assuming ohmic contacts could qualitatively
and successfully explains capacitance and loss tangent behavior.
The ac conductivity showed strong dependence on both temperature and frequency depending on the relevant temperature and frequency
range under consideration. Ac conductivity σ (ω) is found to vary with ω, as ω
s with the index s ≤ 1.35 suggesting a dominant hopping conduction process at low temperatures (< 250 K) and high frequency.
The conductivity of some samples did not increase monotonically with temperature. This behavior was attributed to oxygen exhaustion
of the sample as its temperature is increased. The ac conductivity behavior at low temperatures of ZnPc films could be described
well by Elliott model assuming hopping of charge carriers between localized sites. 相似文献
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Control and exponential stabilization for the equation of an axially moving viscoelastic strip 下载免费PDF全文
Abdelkarim Kelleche Nasser‐eddine Tatar 《Mathematical Methods in the Applied Sciences》2017,40(18):6239-6253
The aim through this work is to suppress the transverse vibrations of an axially moving viscoelastic strip. A controller mechanism (dynamic actuator) is attached at the right boundary to control the undesirable vibrations. The moving strip is modeled as a moving beam pulled at a constant speed through 2 eyelets. The left eyelet is fixed in the sense that there is no transverse displacement (see Figure 1 ). The mathematical model of this system consists of an integro‐partial differential equation describing the dynamic of the strip and an integro‐differential equation describing the dynamic of the actuator. The multiplier method is used to design a boundary control law ensuring an exponential stabilization result. 相似文献