326 research outputs found
Effet dâun programme de dĂ©veloppement des qualitĂ©s physiques sur lâorganisme Des jeunes handballeurs de 9-12ans.
Résumé
Objectifs: ExpĂ©rimenter un programme dâentraĂźnement ayant pour finalitĂ© :le dĂ©veloppement des qualitĂ©s physiques chez les jeunes handballeurs de 9-12ans
Méthodes : Vingt jeunes handballeurs ont subi un entraßnement physique étalé sur sept mois
Lâeffet de entraĂźnement a Ă©tĂ© Ă©valuĂ© par des tests de terrain relatifs au travail rĂ©alisĂ©, en lâoccurrence : le dĂ©veloppement des qualitĂ©s physiques.
Résultats : pour la qualité Vitesse, la différence entre le test préliminaire et le test final est significative à p<0.05 .pour le test du lancer de balle, elle est significative à p<0.001
Le test dâendurance la diffĂ©rence est significative Ă p<0.001 ; pour la dĂ©tente verticale, elle est statistiquement significative Ă p<0.01 ; elle est aussi significative Ă p<0.01 pour le test de souplesse.
Conclusion : Cette Ă©tude nous montre quâun travail rationnel, basĂ© sur les principes de progression pĂ©dagogique exerce une influence positive sur lâorganisme des jeunes sportifs, et les rĂ©sultats issus de notre expĂ©rimentation ne sont que rĂ©vĂ©lateur
Hydrolysis study: Synthesis of novel styrenic Schiff bases derived from benzothiazole
AbstractNovel styrenic Schiff base derivatives of benzothiazole are synthesized. The condensation of 4-vinylbenzaldehyde 1 with either benzothiazol-2-amine or 4-methoxy-benzothiazol-2-amine leads to a mixture of two isomers. From 4-methyl-benzothiazol-2-amine and 6-fluoro-benzothiazol-2-amine, the N-(4-vinylbenzylidene)-4-methyl-benzothiazol-2-amine 8 and N-(4-vinylbenzylidene)-6-fluoro-benzothiazol-2-amine 9 are isolated, respectively. The structures of the synthesized Schiff bases are confirmed through a combination of various spectroscopic techniques including IR, UV, 1H and 13C NMR. A kinetic study of the hydrolysis process of derivatives 6 and 9 in buffered aqueous medium at pH 4.4, 7.4 and 8.5 is conducted by UV spectroscopy. It is shown that the hydrolysis of these compounds is a first order reaction showing an increasing rate as the medium acidity is enhanced
Etude de la morphologie chez les étudiants sportifs algériens
Résumé :
Notre Ă©tude porte sur la dĂ©termination du profil morphologique de lâĂ©tudiant en sport algĂ©rien .Cette population est au nombre de 104 sujets ; rĂ©partis en groupe de sportifs (77) et de non sportifs (27) qualifiĂ©s comme tel par rapport Ă leur expĂ©rience dans la pratique sportive qui nâexcĂšde pas trois annĂ©es; arbitrairement reprĂ©sente la population sĂ©dentaire.
LâintĂ©rĂȘt de cette Ă©tude Ă©mane du dĂ©ficit en matiĂšre de donnĂ©es nationales rĂ©fĂ©rentielles morphologiques de la population AlgĂ©rienne en gĂ©nĂ©ral et sportive en particulier dans toutes ces franges et Ă tous les niveaux de qualification. AprĂšs avoir dĂ©fini les concepts relatifs Ă la biomĂ©trie et le profil ; nous avons mis en exergue certains travaux universels relatifs Ă des Ă©tude comparatives entre les Ă©tudiants et les athlĂštes de haute qualification afin de mieux comprendre la dynamique de lâĂ©volution physique et de mieux cerner les caractĂ©ristiques morphologiques indexant chacune des deux catĂ©gories de pratiquants. A lâissue de lâĂ©tude de lâensemble des caractĂšres et indices morphologiques de la population estudiantine en sport, nous avons procĂ©dĂ© Ă une comparaison de nos rĂ©sultats Ă ceux de la rĂ©fĂ©rences universelle relatifs aux homologues Ă©trangers et Ă ceux des athlĂštes dâĂ©lite AlgĂ©riens.
Par cette approche, nous avons abouti à des résultats qui incitent à pousser des investigations plus poussées dans cet axe
Salinity effects on nutrients uptake, biochemical content and growth response of Blue Panic (Panicum antidotale Retz) and Silage maize (Zea mays L)
Les cultures alternatives tolĂ©rantes Ă la salinitĂ© dĂ©veloppent des mĂ©canismes complexes dans les conditions biosalines. Nous avons Ă©tudiĂ© l'effet de l'eau salĂ©e sur l'absorption des nutriments et les paramĂštres physiologiques et biochimiques du bleu panicum (Panicum antidotale Retz) et du maĂŻs dâensilage (Zea mays L). Des mĂ©socosmes ont Ă©tĂ© Ă©tablis en quatre rĂ©pĂ©titions pour chaque espĂšce de plante dans une conception orthogonale avec diffĂ©rents niveaux d'eau d'irrigation saline comme traitements donnant T0 = 0.9 dS.m-1 (eau du robinet), T1 = 3 dS m-1, T2 = 6 dS m-1 et T3 = 10 dS m-1, pendant 8 semaines. L'augmentation de la salinitĂ© a provoquĂ© un effet dĂ©pressif sur le maĂŻs dâensilage, conduisant Ă une rĂ©duction significative de la croissance (jusqu'Ă 37%), de la biomasse aĂ©rienne sĂšche (jusqu'Ă 58%) et racinaire (jusqu'Ă 87%) par rapport au tĂ©moin. Ainsi qu'une diminution de la chlorophylle a (jusqu'Ă 71 %), de la chlorophylle b (jusqu'Ă 77 %) et des carotĂ©noĂŻdes (jusqu'Ă 49 %) par rapport au tĂ©moin. Pour le bleu panicum, la salinitĂ© n'a par contre pas affectĂ© les paramĂštres physiologiques et biochimiques Ă©tudiĂ©s. L'absorption de lâazote, du phosphore, du potassium et du calcium, du maĂŻs dâensilage a diminuĂ© avec l'augmentation des niveaux de salinitĂ© pour ĂȘtre significative pour une eau d'irrigation avec une conductivitĂ© Ă©lectrique â„ 6 dS m-1 par rapport au contrĂŽle. La teneur en sodium dans les diffĂ©rentes parties du maĂŻs dâensilage (feuille, tige et racine), par contre, a augmentĂ© significativement avec l'augmentation de la salinitĂ©. L'accumulation du calcium, du potassium et de lâazote a lĂ©gĂšrement augmentĂ© chez le bleu panicum, mais nâĂ©tait significatif que dans des parties distinctes de la plante. Dans l'ensemble, notre Ă©tude indique que le maĂŻs est plus sensible aux conditions salines (notamment celles â„ 6 dS m-1) par rapport au bleu panicum qui tolĂšre bien un environnement de salinitĂ© Ă©levĂ© â„ 10 dS.m-1. Nos rĂ©sultats suggĂšrent ainsi que l'introduction du bleu panicum comme culture alternative sur les sols affectĂ©s par la salinitĂ©, comme le pĂ©rimĂštre irriguĂ© de Foum El Oued Ă LaĂąyoune au Maroc, rĂ©sulterait en des rendements Ă©levĂ©s meilleurs que les rendements des cultures traditionnelles comme le maĂŻs dâensilage et amĂ©liorerait donc le revenu des agriculteurs locaux.Saline-tolerant alternative crops develop complex mechanisms under biosaline conditions. We investigated the effect of saline water on nutrient uptake, physiological and biochemical parameters of Blue Panic (Panicum antidotale Retz) and silage maize (Zea mays L). Mesocosms were established in four replicates for each plant species in an orthogonal design with different levels of saline irrigation water as treatments giving T0 = 0.9 dS m-1 (tap water), T1 = 3 dS m -1, T2 = 6 dS m-1 and T3 = 10 dS m-1, for 8 weeks. Increasing salinity caused a depressive effect on silage maize's physiological parameters, leading to a significant decrease in growth (up to 37%), aboveground (up to 58%) and root (up to 87%) dry matter biomass compared to control. As well as a decrease of chlorophyll a (up to 71%), chlorophyll b (up to 77%) and carotenoid (up to 49%) compared to control. For blue panic, salinity did not, however, affect the studied physiological and biochemical parameters. Nitrogen, phosphorus, potassium and calcium uptake, of silage maize, decreased with increasing salinity levels to be significant in irrigation water with electrical conductivity â„ 6 dS m-1 relative to control. The sodium content in different parts of silage maize (leaf, stem and root), on the other hand, increased significantly with increasing salinity. The accumulation of calcium, potassium and nitrogen increased slightly in the blue panic, but this was only significant in separate parts of the plant. Overall, our study indicates that silage maize is more sensitive to saline conditions (particularly â„ 6 dS m-1) compared to blue panic which tolerates well high saline environment â„ 10 dS m-1. Our results, suggest therefore that the introduction of blue panic as an alternative crop on salt affected soils, such as the irrigated perimeter of Foum El Oued in LaĂąyoune in Morocco, would exhibit high performance better than traditional crops as silage maize and therefore would improve the local farmersâ income
THE SYNDROME OF OVERTRAINING AMONG THE ALGERIAN ELITE JUDOKAS (YOUNGER MEMBERS OF THE ALGERIAN NATIONAL TEAM) DURING A COMPETITION FOLLOW-UP
Introduction:  The main objective of this study is to detect the existence of a state of fatigue and a syndrome of overtraining among Algerians judokas of the youngest category (girls and boys) by the use of the questionnaire of fatigue among the child athlete (QFES) and to evaluate the variations of the score by report has its 07 dimensions. Method: 24 judokas cadets of the national team, 14 boys 58.3% and 10 girls 41,7%. The boys are an average age of 16.21±0.21 years, an average weight of 67±16,40kg and a stature of 171,64±9,49cm. They have a body mass index(BMI) of 22.69±4.94 kg/mÂČ.girls have an average age of 16.20±0.78 years, a weight of 59.1±7.89 kg and a stature of 163.9±3,14cm.The BMI is equal to 21,95±2.50 kg/sq. m. The athletes are attending school between the fourth average year at the College and the second year of secondary school. During the period of the microcycle stage of competition which is taking place between 01 March 2017 and 31 May 2017, we distributed the questionnaire at the end of the competition at the Championship in Algeria (Algiers, 27/05/2017). Results: The score of the questionnaire was to 40.01±8.58 (minimum=27, 00, maximum=54), 33.33% of athletes their scores to the QFESâ„45. The average score for an item is 1.1±0.11. The ranking of items of the QFES by average quotation with significant threshold retained of p<0.05. The results are expressed in average ± standard deviation. Conclusion: The main results show that in the questionnaire QFES fatigue is a sensitive tool to detect a state of fatigue. However, a biological study is imperative in order to establish the correlation between syndrome of the overtraining and oxidative stress among young judokas Article visualizations
ĂTUDE DE LA COMPOSITION CORPORELLE DES MEILLEURS LANCEURS ALGERIENS
Résumé:
Le but de cette recherche est d'étudier la composition corporelle des meilleurs lanceurs algériens dans chacune des quatre spécialités de lancers athlétiques.
Vingt quatre athlÚtes composés de cinq lanceurs de poids, sept de disque, sept de javelot et cinq de marteau, avec une moyenne d'ùge générale de (25,32 ans ± 6,70) et représentant les meilleurs lanceurs algériens de la saison 2007-2008, ont pris part à cette étude. Ils ont été soumis à plusieurs mesures anthropométriques qui nous ont permis de déterminer le poids, la taille de chaque spécialité de lancers et de calculer leurs pourcentages de masses musculaire, grasse et osseuse en utilisant les formules de Mateigka.
Aucune différence statistiquement significative n'a été constatée entre les lanceurs de poids, de disque et de javelot concernant la composition corporelle. Des différences significatives ont été constatées entre le groupe des lanceurs de marteau et les autres groupes de lanceurs de l'échantillon, en particulier en ce qui concerne le pourcentage de masse grasse, à p< 0,05 pour les lanceurs de poids, à p< 0,01 pour les lanceurs disque et également pour les lanceurs de javelot.
Abstract:
The aim of this research is to study the body composition of the best Algerian throwers in each of the four athletic throw specialties.
Twenty four athletes composed of five shot put throwers, seven of discus, seven of javelin and five of hammer, with a general age average of (25,32 years ± 6,70), which represent the best Algerian throwers of the season 2007-2008, took part in this study. They have been submitted to several anthropometric measures that allowed us to determine the weight, the size of every specialty of throws and to calculate their percentages of muscular, fat and bone masses while using the Mateigka formulas.
No statistically meaningful difference has been noted between the shot put, discus and javelin throwers concerning the body composition. Some meaningful differences have been noted between the group of the hammer throwers and the other throwers groups of the sample , in particular with regard to the percentage of fat mass, to p <0,05 for the shot put throwers, to p <0,01 for the discus throwers and also for the javelin throwers.
Mots clés: composition corporelle, lanceurs algériens, poids, javelot, disque, marteau
Comparison and Uncertainty Quantification of Two-Fluid Models forBubbly Flows with NEPTUNE_CFD and STAR-CCM+
International audienceThe nuclear industry is interested in better understanding the behavior of turbulent boiling flowsand in using modern computational tools for the design and analysis of advanced fuels and reactorsand for simulation and study of mitigation strategies in accident scenarios. Such interests serve asdrivers for the advancement of the 3-dimensional multiphase Computational Fluid Dynamicsapproach. A pair of parallel efforts have been underway in Europe and in the United States, theNEPTUNE and CASL programs respectively, that aim at delivering advanced simulation tools thatwill enable improved safety and economy of operations of the reactor fleet. Results from acollaboration between these two efforts, aimed at advancing the understanding of multiphaseclosures for pressurized water reactor (PWR) application, are presented. Particular attention is paidto the assessment and analysis of the different physical models implemented in NEPTUNE_CFDand STAR-CCM+ codes used in the NEPTUNE and the CASL programs respectively, forapplication to turbulent two-phase bubbly flows. The experiments conducted by Liu and Bankoff(Liu, 1989; Liu and Bankoff 1993a and b) are selected for benchmarking, and predictions from thetwo codes are presented for a broad range of flow conditions and with void fractions varyingbetween 0 and 50percent. Comparison of the CFD simulations and experimental measurements revealsthat a similar level of accuracy is achieved in the two codes. The differences in both sets of closuremodels are analyzed, and their capability to capture the main features of the flow over a wide rangeof experimental conditions are discussed. This analysis paves the way for future improvements ofexisting two-fluid models. The benchmarks are further leveraged for a systematic study of thepropagation of model uncertainties. This provides insights into mechanisms that lead to complexinteractions between individual closures (of the different phenomena) in the multiphase CFDapproach. As such, it is seen that the multi-CFD-code approach and the principled uncertaintyquantification approach are both of great value in assessing the limitations and the level of maturityof multiphase hydrodynamic closures
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