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1.
Dalila Hammiche Amar Boukerrou Bettache Azzeddine Noamen Guermazi Tatiana Budtova 《International Journal of Polymer Analysis and Characterization》2019,24(3):236-244
The growing interest in the preservation of our environment is pushing for solutions to develop less impacting materials. Thus, the development of biocomposites and is recyclable and compostable end-of-life resources seem an interesting alternative. In this study, the characterization of Polylactic acid (PLA) reinforced with treated and untreated Olive husk flour (OHF) were investigated. More then, their biodegradation with a Bacillus sp. has been evaluated. The main results show that the bacteria degraded both the PLA and the composite. This degradation was confirmed by the release of reducing sugars as well as increasing weight loss of PLA matrix and composites. 相似文献
2.
Azzeddine Elmidaoui Said Belcadi Yves Houdus Thierry Cohen Claude Gavach 《Journal of polymer science. Part A, Polymer chemistry》1992,30(7):1407-1412
Using the preirradiation technique a kinetic study of the grafting of the 4-vinyl pyridine (V4P) and an aliphatic ammonium monomer (ALAM) onto the copolymer film of ethylene–tetrafluoroethylene (ETFE) has been performed. The influence of dose, temperature, and concentration of monomer, reticular agent, and inhibitor were investigated. The results are discussed on the basis of the interactions between monomer diffusibility and viscosity of the medium. The characteristics of some membranes were determined. Their applicability to the recovery of acid by dialysis is demonstrated. 相似文献
3.
Nawel Boucherba Mohammed Gagaoua Estelle Copinet Azeddine Bettache Francis Duchiron Said Benallaoua 《Applied biochemistry and biotechnology》2014,172(5):2694-2705
Jonesia denitrificans BN-13 produces six xylanases: Xyl1, Xyl2, Xyl3, Xyl4, Xyl5, and Xyl6; the Xyl4 was purified and characterized after two consecutive purification steps using ultrafiltration and anion exchange chromatography. The xylanase-specific activity was found to be 77 unit (U)/mg. The molecular weight of the Xyl4 estimated using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) revealed a monomeric isoenzyme of about 42 kDa. It showed an optimum pH value of 7.0 and a temperature of 50 °C. It was stable at 50 °C for 9.34 h. The enzyme showed to be activated by Mn+2, β-mercaptoethanol, and dithiothreitol (DTT) with a high affinity towards birchwood xylan (with a K m of 1 mg ml?1) and hydrolysis of oat-spelt xylan with a K m of 1.85 mg ml?1. The ability of binding to cellulose and/or xylan was also investigated. 相似文献
4.
Kacem Sbai Azzeddine Atibi Ali Abouimrane Mohamed Hliwa Abdelmjid Lahmidi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):909-932
The cyclotriphosphate hexahydrate of manganese and silver, MnAg 4 (P 3 O 9 ) 2 .6H 2 O, was prepared by Boullé's process. MnAg 4 (P 3 O 9 ) 2 .6H 2 O crystallizes in the triclinic system, P-1, Z = 1 and its structure was determined by Rietveld's method. The refinement of 54 parameters by this method, using 1752 independent reflections leads to Rw p = 0.098, R p = 0.065 and R B = 0.033 on the basis of its isotype NiAg 4 (P 3 O 9 ) 2 .6H 2 O. The unit cell parameters of this salt are the following a = 8.824(1)Å, b = 8.485(1)Å, c = 6.609(1)Å, f = 90.30(1)°;, g = 92.89(1)°; and n = 107.28(1)°;. The thermal behavior of this new compound was studied, between 25 and 600°;C, under atmospheric pressure by infrared spectrometry, X-ray diffraction, thermal analyses TGA and DTA coupled. This study allows us the identification and the crystallographic characterization of a new phase, MnAg 2 (PO 3 ) 4 isotype of ZnRb 2 (PO 3 ) 4 , obtained between 350 and 450°;C, mixed with the long-chain polyphosphate of silver AgPO 3 . The kinetic characteristics of the dehydration of MnAg 4 (P 3 O 9 ) 2 .6H 2 O and the thermal phenomena accompanying this dehydration were determined and discussed on the basis of the proposed crystalline structure. The vibrational spectrum of the, MnAg 4 (P 3 O 9 ) 2 .6H 2 O, was examined and interpreted in the domain of the stretching vibrations of the P 3 O 9 rings, on the basis of the proposed crystalline structure and in the light of the calculation of the thirty fundamental IR frequencies for the idealized D 3h symmetry. 相似文献
5.
Abdelmjid Zouahri Azzeddine Elmidaoui 《Journal of polymer science. Part A, Polymer chemistry》1996,34(9):1793-1798
Hydrophilic carboxyl-containing fluoromembranes were obtained by preirradiation grafting of acrylic acid onto ethylene-tetrafluoroethylene film. The dependence of the grafting reaction on temperature, monomer concentration, nature and concentration of inhibitor, crosslinking agent, solvent, and on the preirradiation dose was investigated. The grafting rates increase with temperature, whereas the saturation degree of grafting (SDG) decreases. Addition of inhibitor minimizes homopolymerization and at the same time hinders the grafting reaction. The SDG increases markedly with monomer concentration until it reaches a maximum and thereafter decreases. The grafting rates increase with preirradiation dose. Addition of crosslinking agent initially decreases the SDG, and thereafter increases. The highest grafting rates are obtained using water as solvent followed by methanol and ethanol. The results are discussed on the basis of various parameters: interaction between monomer diffusibility and the viscosity of the monomer bath, the mutual reactivity of monomer, and the crosslinking agent. An agreement is observed between the values of the electrical resistance and the saturation degree of grafting. © 1996 John Wiley & Sons, Inc. 相似文献
6.
New finite elements have been developed to simulate steady and unsteady two-dimensional free surface flows. The depth-averaged velocity components with the free surface elevation have been used as independent variables in the model. The differences between the various elements presented lie in the choice of velocity approximation. The Newton–Raphson method has been used to solve the non-linear system of equations. Emphasis is put on bench-mark examples to assess the accuracy and efficiency of the elements. A simple stable new element tested herein shows promising advantages for industrial finite element codes. 相似文献
7.
Ridha Touihri Azzeddine Soulaimani Franck Plunian 《Theoretical and Computational Fluid Dynamics》2009,23(6):431-437
A stabilized finite element (B, q) formulation is developed to solve the kinematic dynamo problem. As a test case, we solve the induction equation for a given
solid body helical flow, embedded in a cylindrical conducting shell. This problem corresponds to the well-known Ponomarenko
dynamo. It has the interesting property to have an exact dispersion relation giving the magnetic growth rate as a function
of the flow properties. Therefore, it is a good benchmark to test our kinematic dynamo code. We calculated the dynamo threshold
and plotted the geometry of the generated magnetic field. We also evaluated the residual error due to our stabilized formulation. 相似文献
8.
Adil Fahsi Azzeddine Soulaïmani 《International Journal of Computational Fluid Dynamics》2017,31(3):135-155
This paper discusses the application of the extended finite element method (XFEM) to solve two-phase incompressible flows. The Navier–Stokes equations are discretised using the Taylor–Hood finite element. To capture the different discontinuities across the interface, kink or jump enrichments are used for the velocity and/or pressure fields. However, these enrichments may lead to an inappropriate combination of interpolations. Different polynomial enrichment orders and different enrichment functions are investigated; only the stable combination will be used afterward.In cases with a surface tension force, the accuracy mainly relies on the precise computation of the normal and curvature. A novel method for computing normal vectors to the interface is proposed. This method employs successive mesh refinements inside the cut elements. Comparisons with analytical and numerical solutions demonstrate that the method is effective. Moreover, the mesh refinement improves the sub-integration in the XFEM and allows for a precise re-initialisation procedure. 相似文献
9.
A numerical method based on the use of Taylor polynomials is proposed to construct a collocation solution $u\in S_{m-1}^{(-1)}(\Pi _{N})$ for approximating the solution of delay integral equations. It is shown that this method is convergent. Some numerical examples are given to show the validity of the presented method. 相似文献
10.
Bellour Azzeddine Bousselsal Mahmoud Taoudi Mohamed-Aziz 《Mediterranean Journal of Mathematics》2016,13(5):2887-2896
Mediterranean Journal of Mathematics - In this work, we combine the iterative techniques with fixed point theory to investigate the existence of absolutely continuous solutions to a class of... 相似文献