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11.
12.
Simultaneous microwave and ultrasound irradiation is shown as a new technique for digestion of solid and liquid samples suitable for chemical and food analysis. Its application in analytical chemistry has been shown by decreases in digestion time: determination of copper in edible oils and total Kjeldahl nitrogen. 相似文献
13.
Anjan Biswas Swapan Konar Essaid Zerrad 《International Journal of Theoretical Physics》2007,46(1):157-169
The intra-channel collision of optical solitons, with dual-power law nonlinearity, is studied in this paper by the aid of
quasi-particle theory. The perturbation terms that are considered in this paper are the nonlinear gain and saturable amplifiers
along with filters. The suppression of soliton-soliton interaction, in presence of these perturbation terms, is acheived.
The numerical simulations support the quasi-particle theory.
OCIS codes: 060.2310; 060.4510; 060.5530; 190.3270; 190.4370. 相似文献
14.
Essaid Zerrad Richard Triplett Anjan Biswas 《International Journal of Theoretical Physics》2009,48(6):1583-1588
A new numerical method of solving integro-differential equations appearing in the theory of atomic and nuclear scattering
systems has been devised. It is termed Singular Value Decomposition Method (SVD). It consists in expanding the exchange kernel
into a number of separable terms by means of the Singular Value Decomposition and then iterating over the remainder. In this
paper, we extend our SVD method to the scattering of low energy electron-helium which has been the subject of interest, both
theoretically and experimentally. We compare our results with the Moments Method which is widely used. The Moments Method
consists of making an expansion of the solution into an especially favorable basis that takes care of the non-exchange part
of the Hamiltonian. 相似文献
15.
Noureddine Barka Samir Qourzal Ali Assabbane Abderrahman Nounah Yhya Ait-Ichou 《Arabian Journal of Chemistry》2010,3(4):279-283
The photocatalytic degradation of an azo reactive dye, Reactive Yellow 84 (RY84), in aqueous solutions using industrial titanium dioxide coated non-woven paper was studied. The experiments were carried out to investigate the factors that influence the dye photocatalytic degradation, such as adsorption, initial concentration of dye, temperature, and solution pH. The experimental results show that adsorption is an important parameter controlling the apparent kinetics constant of degradation. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model. The degradation was enhanced by the temperature and was favored in acidic pH range. 相似文献
16.
Hamid Ait Abderrahmane Kamran Siddiqui Georgios H. Vatistas 《Experiments in fluids》2011,50(3):677-688
The rotating waves within a hollow vortex core (polygonal patterns) are generated under shallow water conditions inside a
cylindrical tank by a revolving disk at its bottom. We previously reported some basic features of these polygonal patterns
during transition and at the equilibrium states. The present paper includes a more comprehensive investigation into the transition
process of these polygonal patterns and expands the recent partial results that have been previously reported. We show that
the parent wave (or the N-gon pattern) to disk frequencies ratio is around one-third (1/3) regardless of the flow conditions. A detailed insight into the transition process from the parent wave N-gon to daughter wave (N + 1)-gon is provided, which consists of two regimes, quasi-periodic and synchronized. Based on these observations, we explained the
shrinking of the disk speed subintervals over which the N-gon patterns occur, when N increases. 相似文献
17.
Ahmed Ait Mokhtar 《Comptes Rendus Mathematique》2010,348(1-2):1-4
In this Note, we show essentially two results which complete the article by Ait Mokhtar et al., 2008. The first one, having defined the maps purement semi-affines, consists in looking the writing clarify of the compound of these maps. The second result, having defined the tressage, consists in showing that the compound of two tressages is also a tressage. 相似文献
18.
The vapour pressuresof liquid cyclohexane + N, N, N′, N′-tetramethylalkanediamine, (CH3)2 N(CH2)uN(CH3)2 (u = 1,2) + cyclohexane mixtures were measured by a static method between 303.15 and 343.15 K at 10 K intervals. The excess molar enthalpies at 303.15 K were also measured.
The molar excess Gibbs energies, calculated from the vapour-liquid equilibrium data, and the molar excess enthalpies compare satisfactorily with group contribution (DISQUAC) predictions.
The proximity effect of N atoms produces a regular decrease of the interactional parameters. 相似文献
19.
Benzaouia A.; Ait Rami M.; El Faiz S. 《IMA Journal of Mathematical Control and Information》2004,21(3):247-259
A new methodology of the partial eigenstructure assignmentby state feedback via Sylvester equation is used to obtain asolution of the constrained regulator problem for linear continuous-timeand discrete-time systems by using the reduced-order technique. 相似文献
20.
Nonlinear Galerkin methods and mixed finite elements:
two-grid algorithms for the Navier-Stokes equations 总被引:14,自引:0,他引:14
Summary.
A nonlinear Galerkin method using mixed finite
elements is presented for the two-dimensional
incompressible Navier-Stokes equations. The
scheme is based on two finite element spaces
and for the approximation of the velocity,
defined respectively on one coarse grid with grid
size and one fine grid with grid size and
one finite element space for the approximation
of the pressure. Nonlinearity and time
dependence are both treated on the coarse space.
We prove that the difference between the new
nonlinear Galerkin method and the standard
Galerkin solution is of the order of $H^2$, both in
velocity ( and pressure norm).
We also discuss a penalized version of our algorithm
which enjoys similar properties.
Received October 5, 1993 / Revised version received November
29, 1993 相似文献