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Bachir R.G.,University of Mascara | Benali M.,University Djilali Liabes
Asian Pacific Journal of Tropical Biomedicine | Year: 2012

Objective: To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus (E. globulus). Methods: The essential oils of this plant were obtained by the hydrodistillation method. The inhibitory effects of this essential oil were tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by using agar disc diffusion and dilution broth methods. Results: The results obtained showed that essential oil of the leaves of E. globulus has antimicrobial activity against gram negative bacteria (E. coli) as well as gram positive bacteria (S. aureus). Conclusions: The encouraging results indicate the essential oil of E. globulus leaves might be exploited as natural antibiotic for the treatment of several infectious diseases caused by these two germs, and could be useful in understanding the relations between traditional cures and current medicines. © 2012 Asian Pacific Tropical Biomedical Magazine. Source

Henderson J.,Baylor University | Ouahab A.,University Djilali Liabes
Computers and Mathematics with Applications | Year: 2010

In this paper, we first present an impulsive version of the Filippov-Ważewski theorem and a continuous version of the Filippov theorem for fractional differential inclusions of the form (D* α y (t) ∈ F (t, y (t)),, a.e. t ∈ J {set minus} {t1, ..., tm}, α ∈ (1, 2],; y (tk +) = Ik (y (tk -)),, k = 1, ..., m,; y′ (tk +) = over(I, -)k (y (tk -)),, k = 1, ..., m,; y (0) = a, y′ (0) = c,) where J = [0, b], D* α denotes the Caputo fractional derivative, and F is a set-valued map. The functions Ik, over(I, -)k characterize the jump of the solutions at impulse points tk (k = 1, ..., m). Additional existence results are obtained under both convexity and nonconvexity conditions on the multivalued right-hand side. The proofs rely on the nonlinear alternative of Leray-Schauder type, a Bressan-Colombo selection theorem, and Covitz and Nadler's fixed point theorem for multivalued contractions. The compactness of the solution set is also investigated. Finally, some geometric properties of solution sets, Rδ sets, acyclicity and contractibility, corresponding to Aronszajn-Browder-Gupta type results, are obtained. We also consider the impulsive fractional differential equations (D* α y (t) = f (t, y (t)),, a.e. t ∈ J {set minus} {t1, ..., tm}, α ∈ (1, 2],; y (tk +) = Ik (y (tk -)),, k = 1, ..., m,; y′ (tk +) = over(I, ̄)k (y (tk -)),, k = 1, ..., m,; y (0) = a, y′ (0) = c,) and (D* α y (t) = f (t, y (t)),, a.e. t ∈ J {set minus} {t1, ..., tm}, α ∈ (0, 1],; y (tk +) = Ik (y (tk -)),, k = 1, ..., m,; y (0) = a,) where f : J × R → R is a single map. Finally, we extend the existence result for impulsive fractional differential inclusions with periodic conditions, (D* α y (t) ∈ φ (t, y (t)),, a.e. t ∈ J {set minus} {t1, ..., tm}, α ∈ (1, 2],; y (tk +) = Ik (y (tk -)),, k = 1, ..., m,; y′ (tk +) = over(I, -)k (y (tk -)),, k = 1, ..., m,; y (0) = y (b), y′ (0) = y′ (b),) where φ : J × R → P (R) is a multivalued map. The study of the above problems use an approach based on the topological degree combined with a Poincaré operator. © 2009 Elsevier Ltd. All rights reserved. Source

Particularly interesting as candidates to technological applications are the manganese perovskites with AMnO3 formula. Their magnetic structure was described as resulting from a particular ordering of the occupied d orbitals which possess. This reflects my understanding of the structural, electronic and magnetic phenomena, which is well established only in the limit where the systems show localized or itinerant electron behavior. In general, the perovskites of ABO3-type are well known with their (anti)ferroelectric, piezoelectric and (anti)ferromagnetism properties applied in considerable technological investigations. In my paper, I studied the ground states properties of the BaMnO3 perovskite oxide. My structural properties are given using LSDA, GGA, LSDAU and GGAU in the aim to introduce the exchange correlation potential. In the following paper, I use the GGAU on the electronic and magnetic properties calculation. I show in my study the density of states, the band structures and also the charge density figures. My results such as lattice parameter, bulk modulus and its pressure derivative agree very well with available theoretical works and experimental data. I discuss the magnetic moment and the U-Hubbard effect introduced by LSDAU and GGAU on my results given in this paper. © 2011 Elsevier B.V.All rights reserved. Source

Ouahab A.,University Djilali Liabes
Computers and Mathematics with Applications | Year: 2012

In this paper, we first present a version of Filippov's Theorem for fractional semilinear differential inclusions of the form, ( c Dαy-Ay)(t)∈F(t,y(t)), a.e. t∈[0,b],y(0)= y0∈X, where cDα is the Caputo fractional derivative and F is a set-valued map. After several existence results, the compactness of solutions sets is also investigated. Some results from topological fixed point theory together with notions of measure of noncompactness are used. © 2011 Elsevier Ltd. All rights reserved. Source

Faraoun K.M.,University Djilali Liabes
Expert Systems with Applications | Year: 2014

We propose an evolutionary computation approach to design a fast and secure block cipher using non-uniform second-order cellular automata. We build a flexible block ciphering model that permit the construction of a huge space of possible instances defined each one by a finite set of elementary transition rules. The constructed space is explored using a genetic algorithms strategy in order to find an optimal solution with respect to the strict avalanche criterion used as fitness measurements. The genetically designed cipher is benchmarked experimentally using conventional statistical tests, and shown to have very admissible characteristics leading to a very acceptable level of cryptographic security. Moreover, performances analysis shows that the designed cipher permit to achieve a high encryption/decryption speed, and compete many of the existing standardized ciphers. © 2014 Elsevier Ltd. All rights reserved. Source

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