Search

The objective of this paper is to present a rigorous analytical approach, which can simulate the bond slip behavior of tensile reinforced concrete members. The establishment of a set mathematical formulation has allowed taking into account the bond-slip effect without recourse to the topology of the mesh at the interface level. The stresses in concrete and steel are computed based on the bond stress distribution function that was successfully applied to the analysis of reinforced concrete members. The loads carried by concrete and steel along the axis member can be evaluated with the introduced method. The analytical approach is also applied for perfect bond and the obtained results are largely discussed. The numerical examples are presented and the correlation of numerical and experimental results is well observed.

The current study was undertaken to evaluate in vitro the antileishmanial activity of three plants growing wild in Algeria : Juglans regia, Lawsonia inermis and Salvia officinalis. The hydroalcoholic extracts of these plantswere tested on the growth of the promastigotes of Leishmania major. The plant extract effects were compared with three controls : CRL1 composed of 1 ml RPMI inoculated with 106 of promastigotes, CRL2 composed of 1 ml RPMI inoculated with 106 of promastigotes and 100 ìl of hydroalcoholic solvent, CRL3 composed of 1 ml RPMI inoculated with 106 of promastigotes and 100 ìl of Glucantim as a reference drug in the management of leishmaniasis. The results showed that both J. regia and L. inermis extracts reduced the promastigotes number significantly (P

International audience

We present in this paper a CAD tool that aims at designing low-energy buses. The Graphical User Interface (GUI) we developed manages many techniques dealing with the addressed problem: simple coding, coding subject to fixed / dynamic probabilities and an enhanced dynamic probabilities- based technique. Moreover, this environment allows tuning the parameters of data encoding / decoding and is able to generate different gains by varying the size of the bus transferring the encoded data. Thus, this tool is suitable for efficiently designing telecommunication and multimedia systems that are strong data consumers and can be easily configured to integrate new coding techniques, then using one of them when favorably compared against the other techniques.

The quantification of evapotranspiration from irrigated areas is important for agriculture water management, especially in arid and semiarid regions where water deficiency is becoming a major constraint in economic welfare and sustainable development. Conventional methods that use point measurements to estimate evapotranspiration are representative only of local areas and cannot be extended to large areas because of heterogeneity of landscape. Remote sensing based energy balance models are presently most suited for estimating evapotranspiration at both field and regional scales. In this study, SEBAL (Surface Energy Balance Algorithm for Land), a remote sensing based evapotranspiration model, has been applied with Landsat ETM+ sensor for the estimation of actual evapotranspiration in the Habra plain, a semiarid region in west Algeria with heterogeneous surface conditions. This model followed an energy balance approach, where evapotranspiration is estimated as the residual when the net radiation, sensible heat flux and soil heat flux are known. It involves in the input the remote sensing land surface parameters such as surface temperature, NDVI and albedo. Different moisture indicators derived from the evapotranspiration were then calculated: evaporative fraction, Priestley-Taylor parameter and surface resistance to evaporation. These calculated indicators facilitate the quantitative diagnosis of moisture stress status in pixel basis. The study area contains extremes in surface albedo, vegetation cover and surface temperature. The land uses in this study area consists of irrigated agriculture, rain-fed agriculture and livestock grazing. The obtained results concern the validation of the used model for spatial distribution analysis of evapotranspiration and moisture indicators. The evaluation of daily evapotranspiration and moisture indicators are accurate enough for the spatial variations of evapotranspiration rather satisfactory than sophisticated models without having to introduce an important number of parameters in input with difficult accessibility in routine. In conclusion, the results suggest that SEBAL can be considered as an operational method to predict actual evapotranspiration from irrigated areas having limited amount of ground information.

The present paper reports on an investigation to monitor the drought status in Algerian forest covered areas with satellite Earth observations because ground data are scarce and hard to collect. The main goal of this study is to map surface energy fluxes with remote sensing data, based on a simplified algorithm to solve the energy balance equation on each data pixel. Cultivated areas, forest cover and a large water surface were included in the investigated surfaces. The input parameters involve remotely sensed data in the visible, near infrared and thermal infrared. The surface energy fluxes are estimated by expressing the partitioning of energy available at the surface between the sensible heat flux (H) and the latent heat flux (LE) through the evaporative fraction (Λ) according to the S-SEBI (Simplified Surface Energy Balance Index) concept. The method is applicable under the assumptions of constant atmospheric conditions and sufficient wet and dry pixels over a Landsat 7 image. The results are analyzed and discussed considering instantaneous latent heat flux at the data acquisition time. The results confirm the relationships between albedo (r0), the surface temperature (T0) and the evaporative fraction. The method provides estimates of air temperature and LE close to reference measurements. The estimate of latent heat flux and other variables are comparable to those of previous studies. Their comparison with other methods shows reasonable agreement. This approach has demonstrated its simplicity and the fact that remote sensing data alone is sufficient; it could be very promising in areas where data are scarce and difficult to collect.

La présente étude a pour objectif de contribuer au suivi de la désertification au nord d’Algérie par l’utilisation des capteurs MODIS (MODerate resolution Imaging Spectroradiometer) de TERRA. A cet effet, certains paramètres géophysiques (albédo "R0", indice de végétation "NDVI" et température de surface "TS") sont produits régulièrement et couvrent la période de 2000 à 2005. Les combinaisons de ces paramètres deux à deux en particulier R0 -TS ; NDVI-TS et NDVI-R0 ont permis respectivement la caractérisation de l'état hydrique et de l'état de la végétation. La synthèse de l'ensemble des résultats sous un système d’information géographique (SIG), ainsi que leurs confrontations avec d'autres types de données ont permis de dresser des cartes de la sensibilité à la désertification selon cinq degrés (très bon état, bon état, état critique, état dégradé et état très dégradé). Ces résultats montrent qu’environ 75 % des parcours steppiques sont désertifiés ou au seuil de la désertification., The present study aims to work out a methodology based on the use of the sensors such TERRA MODIS (MODerate resolution Imaging Spectroradiometer) in the desertification following and the detection of desertification risk zones in the northern area of Algeria. To this end, some geophysical parameters (albedo "R0", vegetation index "NDVI'' and surface temperature "TS") are produced regularly and cover the period of 2000 to 2005. The combination of these parameters two per two especially R0 -TS, NDVI-TS and R0 - NDVI has allowed respectively the characterization of the hydric and vegetation state. The synthesis of the totality of results under a geographical information system GIS as well as their confrontation with others types of data have allowed to map the desertification risk following five degrees (very high, high, moderated, weak and stable). Our results show that 75 % of the risk zones are already desertify or near of desertification.

In Algeria, arid and semi-arid regions occupy over than 95% of whole territory. Forests in the semi arid zone constitutes a front face to the advance of the desert towards northern sides. Like in other regions of the world, deforestation phenomenon have a serious consequences on the fragile ecosystem. Severe continuous drought, fires, pasture, insects as well as the absence of a clear forest politics are so many factors that reduced forest areas in this country. However, the conservation of this patrimony must be a priority of any regional development project. This paper describes an evaluating study of the deforestation impact on forests in the region of Djelfa situated in the Saharian Atlas using multitemporal satellite remote sensing data. In order to establish a forest change map, a methodology based on the comparison between normalized difference vegetation indexes (NDVI) generated from satellite images was adopted. For this purpose, a pair of Landsat ™ and (ETM+) images acquired over the region on April 11

Introduction La maladie de Moya-Moya peut etre revelee ou aggravee par des crises epileptiques ou par l’epreuve d’hyperpnee lors de la realisation d’electroencephalogramme (EEG). Observation Dossier n° 2306, le patient K, N, 28 ans presenta a l’âge de 23 ans deux accidents vasculaires cerebraux ischemiques ; frontal gauche et jonctionnel anterieur droit reveles par une hemiparesie gauche et des troubles psychiques. Le bilan etiologique etait negatif. L’evolution fut bonne et le patient fut mis depuis sous Aspirine. Lors de la realisation d’une arteriographie cerebrale dans un but etiologique, permettant la decouverte d’une occlusion bilaterale de la terminaison des deux carotides, le patient presenta des convulsions sur la table de l’arteriographie ayant cede sous Valium ® . A son reveil on decouvrit une hemianopsie laterale homonyme droite avec aphasie de Wernicke, le scanner montra alors une vaste ischemie temporo-occipitale gauche. Discussion L’ischemie recente n’est probablement pas une complication directe de l’arteriographie puisque jamais decrite dans la litterature. Le stress de notre patient responsable d’une polypnee pourrait rendre compte de l’ischemie via un phenomene d’hyperventilation. Conclusion Les auteurs suggerent que l’arteriographie realisee dans le cadre de suspicion de maladie de MoyaMoya soit faite sous premedication antiepileptique, surtout si le patient a des antecedents epileptiques.