Investigation of passive shock wave-boundary layer control for transonic airfoil drag reduction

The passive drag control concept, consisting of a porous surface with a cavity beneath it, was investigated with a 12-percent-thick circular arc and a 14-percent-thick supercritical airfoil mounted on the test section bottom wall. The porous surface was positioned in the shock wave/boundary layer interaction region. The flow circulating through the porous surface, from the downstream to the upstream of the terminating shock wave location, produced a lambda shock wave system and a pressure decrease in the downstream region minimizing the flow separation. The wake impact pressure data show an appreciably drag reduction with the porous surface at transonic speeds. To determine the optimum size of porosity and cavity, tunnel tests were conducted with different airfoil porosities, cavities and flow Mach numbers. A higher drag reduction was obtained by the 2.5 percent porosity and the 1/4-inch deep cavity

An alkaliphilic cyclodextrin glycosyltransferase from a new Bacillus agaradhaerens WN-I strain isolated from an Egyptian soda lake: Purification and properties

Alkaliphilic bacteria were isolated from soil and water samples obtained from Egyptian soda lakes in the Wadi Natrun area. Screening for cyclodextrin glycosyltransferase- producing alkaliphilic bacteria resulted in the isolation of 15 positive strains. Strain WN-I was selected as the best producer of CGTase. 16S rDNA sequence analysis and DNA-DNA hybridization identified the isolate as Bacillus agaradhaerens. The enzyme was purified to homogeneity up to 21 fold by starch adsorption and anion exchange chromatography with a yield of 26.40%. The pure enzyme was a monomer with an estimated molecular weight of 85 kDa. The enzyme was stable, at 25°C, over a pH range of 5.0 to 11, with a maximum activity at pH 9.0. The enzyme activity exhibited an optimum temperature of 55°C and was stable at 40°C for at least 1 h. Thermal stability was improved in the presence of maltodextrin, starch or CaCl2. The enzyme was slightly stimulated by CaCl2, KC1 and BaCl2 but was completely inhibited in the presence of FeCl2 and strongly inhibited by ZnCl2 and CoCl2 and to a lower extent by CuCl2, EDTA, 2-mercaptoethanol, and dithiothritol. The enzyme produced mainly β-CD (71.20% of the total cyclodextrin amount). The enzyme had higher cyclyzation activity (1.9 fold higher) toward Paselli starch than soluble starch.Key words: Alkaliphiles, soda lakes, cyclodextrin glycosyltransferase, Bacillus agaradhaeren, purification, 16S rDNA

Techno-economic Analysis of a Wind-Diesel Hybrid Power System in the South Algeria

The electrical energy is often produced with the help of diesel generators in isolated areas in the Saharan region. While the latter requiring relatively little investment because is generally expensive to exploit due to the transportation to remote areas adds extra cost, significant fuel consumption and relatively high maintenance cost, etc. Moreover, the electricity production by the diesel is ineffective, presents significant environmental risks. But these isolated areas have significant wind energy potential; which is good position for the exploitation of clean and sustainable wind energy. The use of wind-diesel power system is widely recommended especially to reduce fuel consumption and in this way to reduce system operating costs and environmental impact. The subject of this paper is to present the techno-economic analysis of a wind-diesel hybrid power system. In this context, the contribution envisaged with this research is to collaborate on the optimal design of a hybrid power system including a wind turbine generator, a diesel generator and an energy storage system for powering a continuous way an isolated site in the South Algerian installed power of 120 kW.This system has a high control strategy for the management of different power sources (wind, diesel, battery) that depending to weather conditions, especially wind speed values and the power demanded by the consumer load

Diagnosis of rotor fault using neuro-fuzzy inference system

The three-phase induction machines (IM) is large importance and are being widely used as electromechanical system device regarding for their robustness, reliability, and simple design with well developed technologies. This work presents a reliable method for diagnosis and detection of rotor broken bars faults in induction machine. The detection faults are based on monitoring of the current signal. Also the calculation of the value of relative energy for each level of signal decomposition using package wavelet, which will be useful as data input of adaptive Neuro-Fuzzy inference system (ANFIS). In this method, fuzzy logic is used to make decisions about the machine state. The adaptive Neuro-Fuzzy inference system is able to identify the IM bearing state with high precision. This technique is applied under the MATLAB®.Keywords: Induction Machine; Diagnosis; Detection; Neuro-Fuzzy inference system

Antimicrobial Activity of Methanol Extract From Stem Bark of Cinnamomum Sintoc

Antimicrobial activity of methanol extract from stem bark of Cinnamomum sintoc has been evaluated against Candida albicans, Staphylococcus aureus and Escherichia coli. The extraction of compound was carried out by maceration, then isolation by column chromatograph, which yielded five (5) subfractions (A-E). Activity against fungus C. albicans, S. aureus bacteria dan E. coli using agar dilution method in paper disk. Methanol extract was not potent against antifungal activity but shows antibacterial activity with medium category. Subfraction C showed that antibacterial activity against S. aureus and E. coli with weak category, but subfractions D and E did not show any activity

LE DEFICIT IMMUNITAIRE COMMUN VARIABLE (A PROPOS DE 6 CAS)

Common variable immunodeficiency (CVID) is a constitutional deficit in the antibody. It can be of transmission recessive, dominating or related to X. The CVID is the only being able to appear at the adulthood. The fundamental cause of this disorder remains unknown. The disease is characterized by the heterogeneity of the clinical picture and the immunological characteristic Our study’s goal is to present un discuss 6 cases of CVID hospitalized at the clinical Immunology Unit, of the Pediatry I department in the child hospital of Casablanca, between March 1998 and March 2004. The mean age at the first clinical symptoms is 11 years. Our six patients, suffered from recurrent pneumonias, the recurrent sinusitis, the chronic diarrhea with failure to thrive and granulomatous disease. They all had a hypogammaglobulinemia, the taking in charge consisted in an infections episode treatment as well as a nutrition rehabilitation with intravenous immunoglobulin antibiotic prophylaxis and a respiratory kinesitherapy. Our set was characterized by the severity of the clinical phenotype, especially by the therapeutic means insufficiency, and the delay of the diagnostic. A considerable effort should be achieved in order to make doctors more sensitive, tools of diagnosis and the hold in charge.Le déficit immunitaire commun variable (DICV) est un déficit primitif en anticorps, de transmission récessive, dominante ou liée à l’X, et qui peut se révéler à l’âge adulte. Son mécanisme moléculaire est encore inconnu. Le diagnostic est caractérisé par une hétérogénéité du tableau clinique et immunologique. L’objectif de notre travail est de présenter et discuter 6 cas de DICV, hospitalisés à l’unité d’immunologie clinique de la Pédiatrie I à l’hôpital d’Enfants de Casablanca, sur 6 ans (1998 – 2004). L’âge moyen de début des symptômes est de 11 ans. Nos 6 malades avaient présenté des broncho-pneumopathies à répétitions, des infections ORL, des diarrhées chroniques avec retentissement staturo-pondéral, et un cas de sarcoïdose. Ils avaient présenté tous une hypogammaglobulinémie globale. La prise en charge a consisté en un traitement des épisodes infectieux, une perfusion des immunoglobulines, une antibioprophylaxie et une kinésithérapie respiratoire. Le tableau clinique de nos malades reste sévère du fait du retard du diagnostic et de l’insuffisance des moyens thérapeutiques ; c’est pourquoi un effort doit être réalisé, afin de sensibiliser les médecins, pour établir un diagnostic précoce et une prise en charge adéquate

Analyse phytochimique et évaluation de la toxicité aiguë par voie orale chez des rats de l’extrait total aqueux des feuilles de Abrus precatorius Linn (Fabaceae)

Abrus precatorius est reconnue en médecine traditionnelle pour ses nombreuses vertus thérapeutiques. En Côte d’Ivoire, les feuilles sont utilisées dans une boisson pour le traitement des troubles gynécoobstétriques. Au Nigeria, le décocté des feuilles est utilisé dans le traitement du diabète. Des travaux antérieurs sur la plante ont mis en évidence la présence de l’abrine qui est un composé chimique toxique contenu dans les feuilles et dans les graines. L’intérêt de l’utilisation des feuilles de Abrus precatorius exige qu’une approche de sa toxicité puisse être entreprise en vue d’évaluer son innocuité chez l’homme. La présente étude a consisté évaluer la toxicité aiguë par voie orale de l’extrait total aqueux des feuilles de Abrus precatorius (ETAAP) chez des rats. Une analyse phytochimique basée sur des réactions de coloration et/ou de précipitation a été effectué afin d’identifier les composés chimiques présent dans l’extrait. La Dose Létale 50 (DL50) a été déterminée et les animaux ont été observés durant 14 jours après un gavage unique à des doses de 5 mg/kg, 50 mg/kg, 300 mg/kg, 2000 mg/kg et 5000 mg/kg de poids corporels (pc) contre un témoin. La DL50 obtenue a été supérieure à 5000 mg/kg de pc, aucune mortalité et aucun signe clinique de toxicité n’a été observé chez tous les animaux. Cette étude révèle que l’ETAAP est non toxique par voie orale chez des rats. L’analyse phytochimique a montré une hétérogénéité de groupes chimiques (alcaloïdes, tanins, flavones, coumarines, saponines, stérols, triterpènes et des composés réducteurs) dont la présence dans l’extrait pourrait être responsable des propriétés thérapeutiques attribuées à Abrus precatorius.Mot clés : Abrus precatorius L, médecine traditionnelle, innocuité, DL50

Gold nanoparticles as catalysts for low-temperature WGS reaction

OBJECTIVES: This study aimed to compare the phenotype of Rett syndrome cases with C-terminal deletions to that of cases with different MECP2 mutations and to examine the phenotypic variation within C-terminal deletions. METHODS: Cases were selected from InterRett, an international database and from the population-based Australian Rett Syndrome Database. Cases (n=832) were included if they had a pathogenic MECP2 mutation in which the nature of the amino acid change was known. Three severity scale systems were used, and individual aspects of the phenotype were also compared. RESULTS: Lower severity was associated with C-terminal deletions (n=79) compared to all other MECP2 mutations (e.g. Pineda scale C-terminals mean 15.0 (95% CI 14.0–16.0) vs 16.2 (15.9–16.5). Cases with C-terminal deletions were more likely to have a normal head circumference (odds ratio 3.22, 95% CI 1.53 – 6.79) and weight (odds ratio 2.97, 95% CI 1.25–5.76). Onset of stereotypies tended to be later (median age 2.5 years vs 2 years, p<0.001 from survival analysis), and age of learning to walk tended to be earlier (median age 1.6 years vs 2 years, p=0.002 from survival analysis). Those with C-terminal deletions occurring later in the region had lower average severity scores than those occurring earlier in the region. CONCLUSION: In terms of overall severity C-terminal deletion cases would appear to be in the middle of the range. In terms of individual aspects of phenotype growth and ability to ambulate appear to be particular strengths. By pooling data internationally this study has achieved the case numbers to provide a phenotypic profile of C-terminal deletions in Rett syndrome