Technical and economical performance of parabolic through collector power plant (SEGS VI)

Les centrales solaires à concentration sont une excellente alternative à celles conventionnelles pour les pays de la ceinture solaire. Les centrales SEGS installées en Californie ont fait l'objet de plusieurs études. Dans ce travail, nous proposons l'étude et la simulation de la SEGS VI pour son implémentation en Algérie. Un modèle numérique a été établi en utilisant le logiciel TRNSYS. Quatre sites ont été retenus pour la simulation. Les résultats obtenus nous ont permis de calculer le prix du kWh. En se basant sur le LEC le plus faible, nous avons retenu le site de Béchar

Novel micro-flat springs using the superior elastic properties of metallic glass foils

A thin metallic glass foil of 100 mg mass forming a sinusoidal arc behaves as non-conventional flat micro-spring withstanding loads 105 times higher than its load. Upon a normal load applied on the top of the arc, the foil deforms elastically leading to sinusoidal wavy patterns of higher order. The lifespan of the novel spring is higher than conventional low cycle springs and can potentially be further improved by eliminating surface and edge preparation induced defects. This unique behavior of metallic glass foils has the potential to revolutionize the field of springs and can be exploited for numerous applications

USE OF CHROMAGAR ORIENTATION FOR PRESEMPTIVE IDENTIFICATION OF ENTEROCOCCI AND CHARACTERIZATION OF ANTIMICROBIAL RESISTANCE OF THE ISOLATES

This study was conducted to evaluate the use of CHROMagar Orientation for presumptive identification of enterococci from poultry, and to characterize the antimicrobial resistance of the isolates. Strains identification with conventional methods allowed confirmation of Enterococcus genus membership of all of the isolates on CHROMagar orientation (100%). Of the 141 enterococci isolates obtained from chicken, 81 (57.45%) were identified as Enterococcus faecalis and 60 (42.55%) as Enterococcus faecium. The antimicrobial susceptibility test presented high level of resistance to Tetracycline (89%) and Erythromycin (65%), low level of resistance to High Level of Streptomycin, Penicillin and Ciprofloxacin (13%, 10% and 9% respectively). Few of isolates were resistant to Chloramphenicol (2%). All the strains were susceptible to High Level of Gentamycin, Ampicillin, Vancomycin and Nitrofurantoin. The predominant phenotype of resistance pattern identified in both E.faecalis and E.faecium was (Erythromycin -Tetracycline)

La différence épidémiologique des hémorragies digestives hautes entre les hommes et les femmes

Introduction: Des différences épidémiologiques, étiologique voire pronostique des hémorragies digestives hautes (HDH) entre les deux sexes opposés ont été cité par différentes études. Méthodes: Nous avons essayé de déceler ces différences à travers une analyse rétrospective nichée sur une étude prospective sur les hémorragies digestives hautes ayant inclus 945 patients.Résultats: Six cents trente-sept patients étaient des hommes (67,4% Vs 32,6%). Un antécédent d’HDH était trouvé chez 24,2% des cas sans différence significative entre les deux sexes. L’âge de survenue de l’hémorragie était plus élevé chez les femmes que chez les hommes : 51,5 ans ± 18,8 Vs 47,8 ans ± 18,3 (p : 0,003). Les étiologies de l’HDH étaient différentes entre les deux sexes. Alors que l’hémorragie liée à l’HTP était la première cause chez la femme (38 % Vs 23,5 % chezl’homme, p<0,0001), c’est la pathologie ulcéreuse qui venait en premier chez l’homme (62 % Vs 36,7 % chez la femme, p <0,0001). Un besointransfusionnel était noté chez 42,4 % des patients de sexe masculin contre 35,4 % des patientes avec un p = 0,03. Le taux de récidive et de décès global étaient de 7,5 % et de 5,7 % des cas respectivement, sans différence significative entre les deux sexes.Conclusion: L’étude trouve un profil épidémiologique, clinique et étiologique différent selon le sexe des patients.Key words: Hémorragie digestive haute, épidémiologie, sexe masculin, sexe féminin, endoscopie, ulcère gastroduodénal, hypertension portal

Mechanically induced waves in metallic glass foils

The response of vitrified metallic arc foils under normal load is studied. Application of normal load on an initial arc shaped vitrified metallic foil is followed by multiplication of the initial arc. A sinusoidal mathematical expression can be used for the description of the produced harmonic undulations. The number of the formed waves increases as the displacement increases. Therefore, this undulatory behavior of the vitrified foils can be exploited as a flat spring with multiple spring constants. For comparison crystalline foils were tested. The enormous elastic region of vitrified alloys allows this undulatory response to occur extensively while plastic deformation is unavoidable when crystalline foils are used. Exploiting the metallic glass characteristics, the predefined extrem a positions of the formed undulations and the mechanical characteristics of the vitrified foils a new type of electromechanical switch is suggested. (c) 2015 Elsevier Ltd. All right

ROSEMARY ESSENTIAL OILS: EXTRACTION, GC/MS ANALYSIS, ANTIOXIDANT ACTIVITY WITH DFT AND IN SILICO INSIGHTS OF PROSPECTIVE NANO-ANTIOXIDANTS

The objective of this work is to identify the bioactive molecules in the essential oil of the dried leaves of Rosemary from two cities in the Eastern region of Morocco: Taourirt and Jerrada. These essential oils have already been extracted by the steam distillation method in the cooperative. the chemical composition have been determined by gas chromatography coupled with mass spectrometry (GC/MS), in which cineole 41.77%, alpha-Pinene 10.75% and Camphor 9.32% represent the majority compounds for essential oil of Rosemary from Taourirt and cineole 51.68%, alpha-Pinene 11.91 % and Camphor 10.29 % predominate in that of Jerada rosemary. Antioxidant activity in vitro was assessed in three different ways: the DPPH test, the β-carotene bleaching technique, and the reduction power measurement. The DFT analysis of the different compounds and the Docking study were also investigated in objective to study the molecular reactivity of the majority compounds, also study their affinity to various cyclodextrin as prospective encapsulation systems

ANTIMYCOBACTERIAL, ANTIOXIDANT AND CYTOTOXIC ACTIVITIES OF ESSENTIAL OIL OF GALL OF PISTACIA ATLANTICA DESF. FROM ALGERIA

Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria. Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium fortuitum. Antioxidant activity was determined using free-radical scavenging assays. The safety of essential oil was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on C3A and Vero monkey kidney cells. Results: The minimal inhibitory concentration (MIC) values ranged from 0.16 to 2.5 mg/mL with minimal bactericidal concentration (MBC) values ranged from 0.62 to >2.5 mg/mL. The antioxidant activity showed IC50 values ranged between 417.61 - >2000µg/mL and 495.6 - >2000µg/mL for DPPH and ABTS assay respectively. The cytotoxicity assay showed LC50 ranged between 26.47 to 93.64 µg/mL against Vero cells and 74.29 to 225.40 µg/mL against C3A. The results of this study show that the essential oils from the gall of P. atlantica have low toxicity and moderate activity against fast growing M. smegmatis and M. aurum. Conclusion: These results substantiate their potential as used in the treatment of non-tuberculous mycobacterial infections. This finding is predictive of their activity against M. tuberculosis, therefore, further study might be considered to investigate the activity against pathogenic Mycobacterium strains