检索结果-南通市图书馆

GENERAL DECAY FOR A POROUS-THERMOELASTIC SYSTEM WITH MEMORY: THE CASE OF NONEQUAL SPEEDS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2013年第1期33卷 23-40页

作者： salim a.messaoudi Abdelfeteh FAREH Departement of Mathematics and Statistics King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Departement of Mathematics Faculty of Science and TechnologyUniversity of El-OuedBP78939000El OuedAlgeria

The aim of this paper is to establish a general decay result for a one-dimensional porous elastic system with different speeds of wave propagation in the presence of macrotem- perature effect and visco-porous dissipat... 详细信息

关键词： general decay visco-porous dissipation non equal speeds

A GENERAL DECAY AND OPTIMAL DECAY RESULT IN A HEAT SYSTEM WITH A VISCOELASTIC TERM

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2019年第2期39卷 618-626页

作者： Abderrahmane YOUKANA salim a.messaoudi Aissa GUESMIA Department of Mathematics University of Batna Department of Mathematics and Statistics KFUPM Elie Cartan Institute of Lorraine Universite de Lorraine Department of Mathematics and Statistics King Fahd University of Petroleum and Minerals

We consider a quasilinear heat system in the presence of an integral term and establish a general and optimal decay result from which improves and generalizes several stability results in the literature.

关键词： heat equation viscoelastic general decay optimal

THEORETICAL AND NUMERICAL STUDY OF THE BLOW UP IN A NONLINEAR VISCOELASTIC PROBLEM WITH VARIABLE-EXPONENT AND ARBITRARY POSITIVE ENERGY

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2022年第1期42卷 141-154页

作者： Ala A.TALAHMEH salim a.messaoudi Mohamed ALAHYANE Mathematics Birzeit UniversityWest BankPalestine Mathematics University of SharjahP.O.Box 27272SharjahUAE Department of Mathematics RISEUniversity of SharjahP.O.Box 27272SharjahUAE

In this paper,we consider the following nonlinear viscoelastic wave equation with variable exponents:utt-△u+∫_(0)^(t)g(t-τ)△u(x,τ)dτ+μut=|u|^(p(x)-2)-u,whereμis a nonnegative constant and the exponent of nonlinearity p(·)and g are given *** arbitrary positive initial energy and specific conditions on the relaxation function g,we prove a finite-time blow-up *** also give some numerical applications to illustrate our theoretical results.

关键词： nonlinear damping blow up finite time variable nonlinearity arbitrary positive energy

Study on the sensitivity to cadmium of marine fish Salaria basilisca(Pisces: Blennidae)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第11期21卷 1620-1624页

作者： Imed messaoudi Sana Barhoumi Khaled Sd Abdelhamid Kerken UR 09/30: Genetic and Biodiversity. Institute of Biotechnology Trace Elements Free Radicals Antioxidant Systems and Environment and Humain Pathology

The present study tested the sensitivity of Salaria basilisca to water-cadmium （Cd） contamination. For this purpose, liver somatic index （LSI）, Cd concentrations and the activities of antioxidant enzymes such as catalase （CAT）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） were measured in the liver of S. basilisca exposed to Cd-contaminated water （2 mg Cd/L as CdCl2） for 14 and 28 d. The results showed that the LSI decreased significantly after 14 and 28 d of Cd-exposure. Cd bioaccumulation in the liver resulted in an increasing uptake up to 42 μg/g dry weight after 28 d of exposure. Activities of CAT and SOD were significantly increased with increasing exposure time. A significant increase in GSH-Px activity, under Cd influence, was observed during 14-day exposure period （p 〈 0.0001）. However, a significant decrease （p 〈 0.05） in this activity with respect to control fish was registered after 28 d of Cd-exposure. These results showed that Cd accumulation in the liver of S. basilisca could induce oxidative stress as demonstrated by changes in the antioxidant enzyme activities. Results also emphasized that S. basilisca may considered as a sensitive species to Cd exposure.

关键词： cadmium Salaria basilisca oxidative stress antioxidant enzymes

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第7期21卷 980-984页

作者： BARHOUMI Sana.messaoudi Imed DELI Tmim SAD Khaled KERKENI Abdelhamid Trace Elements Free Radicals Antioxidant Systems and Environment and Humain Pathology Faculty of Medicine 5000 Monastir Tunisia UR 09/30: Genetic and Biodiversity Institute of Biotechnology 5000 Monastir Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium （Cd） pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination： the industrialized coast of Sfax （S 1）, the coast of Douar Chatt （S2） and the coast of Luza （S3）. The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher （t9 〈 0.0001） than those from S2 and S3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order： S 1 〉 S2 〉 S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors （BAF） greater than 1 in all studied sites. In S 1 and S2, BAF values respect the following order： S. basilisca 〉 Z. ophiocephalus 〉 S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccumulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gabes.

关键词： bioaccumulation cadmium Gulf of Gabes Salaria basilisca Solea vulgaris Zosterisessor ophiocephalus Tunisia

Reactivity of Nanostructured MnO_2 in Alkaline Medium Studied with a Microcavity Electrode: Effect of Oxidizing Agent

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第7期27卷 585-593页

作者： L.Benhaddad L.Makhloufi B.messaoudi1 K.Rahmouni H.Takenouti Laboratoire de Technologie des Matériaux et Génie des Procédés (LTMGP) Département de Génie des Procédés. Université A. MiraRoute de Targa Ouzemmour06000 BéjaiaAlgeria UPR 15 du CNRS LISE-Laboratoire Interfaces et Systèmes Electrochimiques UPMC University Paris 06Case 133 4 place Jussieu 75252 Paris Cedex 05 France UPR 15 du CNRS LISE-Laboratoire Interfaces et Systèmes Electrochimiques UPMC University Paris 06Case 1334 place Jussieu 75252 Paris Cedex 05France

The synthesis of MnO2 powders by hydrothermal method with different oxidizing agents has been successfully achieved. The characterizations by scanning electron microscopy, energy-dispersive X-ray analyses, transmission electron microscopy, and X-ray diffraction techniques confirm the synthesis of nanostructured γ-MnO2 powders. The electrochemical reactivity of these powders in 1 mol/l KOH is investigated by cyclic voltammetry and electrochemical impedance spectroscopy （EIS） by using microcavity electrode. The results reveal that the MnO2 synthesized with Na2S2O8 shows the highest electrochemical reactivity in the test medium. This is due both to its large expanded surface area and its crystallographic variety γ-MnO2 formed in the matrix of ramsdellite, which is largely used as cathodic material for primary batteries. However, the presence of pyrolusite in the structure of γ-MnO2 synthesized with （NH4）2S2O8 decreases its electrochemical reactivity due to its narrow 1×1 size tunnel, which hinders the protons insertion.

关键词： Hydrothermal processing Electrochemical impedance spectroscopy (EIS) Cyclic voltammetry X-ray diffraction γ-MnO2

Identification and preliminary characterization of non-polyene antibiotics secreted by new strain of actinomycete isolated from sebkha of Kenadsa, Algeria

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2015年第6期5卷 438-443页

作者： Omar messaoudi Mourad Bendahou Ibrahim Benamar Djamal-Elddine Abdelwouhid Microbiology Laboratory Applied to Food Biomedical and Environmental (LAMAABE) University of Abou bekr Belkaid Faculty of SNV-STU- Ex Imama Biomedical ComplexPB 119 Tlemcen 13000 Algeria Faculty of Science Department of Biology University of Amar Telidji

Objective: To study the antimicrobial activity of actinomycetes isolated from sabkha of Kenadsa and identification of the isolate interesting. Methods: Eighteen strains were isolated, using four culture media from sebkha of Kenadsa(Bechar, Southwestern Algeria). Screening of antimicrobial activity consisted of two steps: in primary screening, antibacterial activity was determined by using the agar plug method against test strains; in secondary screening, better isolate which showed a good activity in the first screening was selected to extract antimicrobial substances. The antimicrobial activities of extracts were evaluated by using Kirby-Bauer disc diffusion method. Partial characterization of antimicrobial products was performed on the basis of chemical revelations, UV-vis spectrometry and infrared spectroscopy. The identification of isolate interesting was performed through morphological, chemical, biochemical and physiological characteristics. Results: All isolates showed antimicrobial activity against at least one microorganism test. One isolate, LAM143 cG 3, was selected for its broad spectrum and high antimicrobial activity. The isolate LAM143 c G3 was identified as Spirillospora sp. The comparison between the species of this genus(Spirillospora rubra and Spirillospora albida) and our isolate indicated the existence of several physiological and biochemical differences which led us to suppose that this was a new member of this genus. Primary characterization of antimicrobial substances produced by the isolate LAM143 c G3 indicated the presence of amines and phenols. The UV–vis spectrum suggested a non-polyenic nature of substances secreted by our isolate, while infrared confirmed the presence of amine ***: The result of the present study revealed that sebkha of Kenadsa was rich in rare actinomycetes, that secreted interesting antimicrobial substance.

关键词： Isolation Actinomycetes Sebkha Kenadsa Non-polyene Identification Spirillospora

Feedback Systems on a Reflexive Banach Space—Linearization

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modern Nonlinear Theory and Application 2020年第2期9卷 34-50页

作者： messaoudi Khelifa Faculty of MI Department of Mathematics University of Batna 2 Batna Algeria

The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on real reflexive Banach spaces, as well as the approximation in a neighborhood of zero, of solutions of a feedback system [A,B] assumed to be non-linear, by solutions of another linear, This approximation allows us to obtain appropriate estimates of the solutions. These estimates have a significant effect on the study of the robust stability and sensitivity of such a system see [1] [2] [3]. We then consider a linear FS , and prove that, if ; , with the respective solutions of FS’s [A,B] and corresponding to the given (u,v) in . There exists,, positive real constants such that, . These results are the subject of theorems 3.1, ... , 3.3. The proofs of these theorems are based on our lemmas 3.2, ... , 3.5, devoted according to the hypotheses on A and B, to the existence of the inverse of the operator I+BA and . The results obtained and demonstrated along this document, present an extension in general Banach space of those in [4] on a Hilbert space H and those in

关键词： Nonlinear Feedback System Linearization Reflexive Banach Space Normality Lipschitz Continuity

Cytotoxic, antioxidant and antimicrobial activities of Nerium oleander collected in Morocco

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2019年第1期12卷 32-37页

作者： messaoudi Mouhcine Laglaoui Amin Amzazi Saaid Hammani Khalil Benbacer Laila El Mzibri Mohammed Unité de Biologie et Recherche Médicale CNESTEN Laboratoire de Biochimie-Immunologie Faculté des Sciences Mohammed V University équipe de Recherche en Biotechnologies & Génie des Biomolécules Faculté des Sciences et Techniques de Tanger Abdelmalek Essaadi University Laboratoire de Ressources Naturelles et Environnement Faculté Polydisciplinaire de Taza Sidi Mohammed Ben Abdellah University

Objective: To investigate the cytotoxic, antioxidant and antibacterial activities of ethanolic and aqueous crude extracts of Nerium oleander(N. oleander) leaves. Methods: Cytotoxic activities were evaluated by WST-1 bioassay on two human cancer cell lines, namely human colon adenocarcinoma cell line HT-29 and human breast cancer cell line MDA-MB-231. The antioxidant property of N. oleander extracts was assessed by DPPH scavenging and he agar disc diffusion method was used for the determination of an毬-carotene bleaching tests. Ttimicrobial activity against different strains. Results: Using cell viability indices, the WST-1 test revealed that both extracts reduced cell viability in both cell lines. Our results also showed that aqueous extract was more active than ethanolic extract, with IC50 values of(1.67±0.22) μg/mL and(2.36±0.44) μg/mL on MDA-MB-231 cells, and(2.89±0.35) μg/mL and(5.09±0.52) μg/mL on HT29 cells, respectively. The study of the antioxidant activity showed that N. oleander extracts had a considerable scavenging capacity and exerted a significant preventive effect against the oxidation of 毬-carotene by the peroxide radicals. However, the antibacterial test showed that both ethanolic and aqueous extracts of N. oleander had a moderate antibacterial effect limited only to Gram-positive bacteria. Conclusions: Our results shows that N. oleander aqueous and ethanolic extracts have significant cytotoxic activities against tumor cell lines and possesses a strong antioxidant capacity, suggesting the presence of active compounds in N. oleander leaves that could be a potential source of phytochemicals with high medicinal value to be used in cancer treatment and prevention.

关键词： Nerium oleander Anti-cancer Cytotoxicity Antioxidant Antimicrobial Bioactive compounds