The knowledges of traditional irrigation in the oasis of Kerzaz in southwest Algerian: Legacy and development

In the valley of Saoura, the demand for water for irrigation has increased significantly and rapidly, it requires mobilization and rational and intensive use of all existing water sources like the groundwater which are the only source of drinking water supply and irrigation in the region and the protection of the large vein that feeds the Saoura and bearing his name "oued Saoura". Oasis Kerzaz is amongst the the most celebrated oasis and the biggest of valley of Saoura , it now suffers from several impediments to their development as: the scarcity of irrigation water, land abandonment, the silting up, the chunking and the exiguity of agricultural land, the food nature of agricultural activity and incurable diseases of crops.Keywords: palm grove; well; Chadouf; Khottara; motorpump; Saoura

The fate of water in the oasis of Ouakda between traditional systems and modern (Region of Béchar, Southwest, Algeria)

One of the subjects that touch the field of environment is undoubtedly the traditional catchment systems and drainage divide in the oasis. The ancestral techniques such as wells chadouf, quanat, Khettara and foggaras have protected the oasis and the man in the past. These techniques were used in an arid middle by the oasis dwellers and resisted to a hostile climate for centuries. In spite of the low rainfall in the region of our oasis, the oasis dwellers of Ouakda through their intelligence, they were able to cultivate their land without disturbing a fragile ecosystem through exploitation of groundwater table thanks to the use of foggaras with the small distance which does not exceed 100 m. But the intervention of modern systems of water catchment like deep boreholes which overexploiting nonrenewable tablecloths and the pumps large capacity, the man has completely destroyed a clean environment. Today, thanks to these pumping, the groundwater level has dropped considerably; soil salinity is remarkable on all the parcels of the old palm grove and the Oued. We try in this Article to study the history of traditional techniques of water catchments in the oasis of Ouakda, to do a comparison between the ancestral systems used in the another oasis in this oasis, to study the impact of the motor pumps on the degradation of traditional systems and detrimental effects (Soil salinity and the phenomenon of lowering of the groundwater) after the use of modern techniques of water catchment.Keywords: Oasis, Ouakda, Foggara, Wells, Chadouf, motor pump

THE ORIGINALITY OF OASIS OF SAOURA IN SOUTH-WEST OF ALGERIA

For centuries the oases of the Saoura continue to manage critical situations of drought and the hostility of the Algerian Sahara through the rational exploitation of water, a rare and precious source of traditional irrigation techniques have proved their efficiency. The use of new groundwater drainage systems of drilling, and the lack of effective management of the Foggaras, has made this system lose its value, deteriorate and let the palm groves disappear. More than 80% of these systems have been abandoned in recent years. With increasing urbanization, population growth, climate change and the uncontrolled proliferation of motor pumps, the level of the water table is lowered and the quality of the water is degraded. The foggaras have gradually been abandoned, which leads to the degradation of the gardens and the old oasis

Dacryoadenite tuberculeuse bilatérale: à propos d’un cas

La dacryoadénite tuberculeuse est une inflammation rare de la glande  lacrymale causé par le bacille Mycobacterium tuberculosis. Elle pose unproblème étiopathogénique et diagnostique. Nous rapportons dans cette observation le cas d'une dacryoadénite tuberculeuse bilatérale chez unjeune homme Marocain de 34 ans ayant présenté une tuberculose  ganglionnaire et du cavum il y à 14 ans, ayant été confirmé par l'examenanatomopathologique. La tuberculose reste un diagnostic qui doit être  toujours évoqué même dans les atteinte bilatérale surtout si il y a unantécédent personnel ou familiale positif de tuberculose. Le pronostic de cette affection est devenu favorable grâce au traitement antibacillaire précoce

The BELFRAIL (BFC80+) study: a population-based prospective cohort study of the very elderly in Belgium

In coming decades the proportion of very elderly people living in the Western world will dramatically increase. This forthcoming "grey epidemic" will lead to an explosion of chronic diseases. In order to anticipate booming health care expenditures and to assure that social security is funded in the future, research focusing on the relationship between chronic diseases, frailty and disability is needed. The general aim of the BELFRAIL cohort study (BFC80+) is to study the dynamic interaction between health, frailty and disability in a multi-system approach focusing on cardiac dysfunction and chronic heart failure, lung function, sarcopenia, renal insufficiency and immunosenescence

Characterization of Ga1−x\mathsf{_{1-x}}Inx\mathsf{_x}Sb thin layers grown on GaAs substrate by infrared reflectivity

Infrared reflectivity measurement are made on Ga$_{0.70}$In$_{0.30}$Sb thin layers grown on semi-insulating GaAs substrate with free-carrier density varying from 10$^{17}$ cm$^{-3}$ to 10$^{18}$ cm$^{-3}$. Electrical and optical parameters of the layers are determined simultaneously by fitting appropriate theoretical model with experimental data. Densities and mobilities obtained are of the order of the ones given by Hall measurements and optical parameters are in good agreement with those given in the literature.Des mesures de réflectivité infra-rouge sont faites sur des couches de Ga$_{0,70}$In$_{0,30}$Sb épitaxiées sur substrat de GaAs semi-isolant avec une densité de porteurs allant de 10$^{17}$ cm$^{-3}$ à 10$^{18}$ cm$^{-3}$. Les paramètres électriques et optiques de la couche sont déterminés simultanément en ajustant les données expérimentales par le modèle théorique approprié. Les densités et mobilités obtenues sont comparables à celles données par les mesures d'effet Hall, et les paramètres optiques sont en bon accord avec les valeurs données dans la littérature

Spectral responses in near-infrared of the mixed compounds III-V, ternary and quaternary, based on GaSb

From the simulation of the spectral response of the different photodetector devices elaborated in our laboratory (C.E.M.), we determine the influence of geometrical and physical parameters in order to achieve the best photodetector operating at the wavelength 2.55 $\mu$m. In this paper we present: Gao$_{0.6}$In$_{0.4}$Sb$_{\rm n}$/Ga$_{0.6}$In$_{0.4}$Sb$_{\rm p}$ homojunctions matched on GaSb$_{\rm p}$ substrate, Ga$_{0.75}$In$_{0.25}$As$_{0.23}$Sb$_{\rm p}$/GaSb$_{\rm n}$ ternary heterojunction and GaSb$_{\rm p}$/Ga$_{0.74}$In$_{0.26}$As$_{0.23}$Sb$_{\rm 0.77p}$/GaSb$_{\rm n}$ quaternary heterojunction. The GaSb$_{\rm p}$ layer with an energy band gap greater than Ga$_{0.74}$In$_{0.26}$As$_{0.23}$Sb$_{\rm 0.77p}$ optical gap will act as a window, reducing the effect of surface recombinaison. Results of the simulation are compared to experimental curves to determine the values of photoelectrical parameters (diffusion length, recombination velocity at the surface ...).Les mesures de réponse spectrale dans la gamme [0,4 eV à 2 eV] ont été effectuées sur des homojonctions, Ga$_{0,6}$In$_{0,4}$Sb$_{\rm n}$/Ga$_{0,6}$In$_{0,4}$Sb$_{\rm p}$ déposées sur un substrat de GaSb et des hétérostructures ternaires Ga$_{0,75}$In$_{0,25}$Sb$_{\rm p}$/GaSb$_{\rm n}$ et quaternaires GaSb$_{\rm p}$/Ga$_{0,74}$In$_{0,26}$As$_{0,23}$Sb$_{\rm 0,77p}$/GaSb$_{\rm n}$. La couche de GaSbp avec un gap plus grand que celui de Ga$_{0,74}$In$_{0,26}$As$_{0,23}$Sb$_{\rm 0,77p}$ joue le rôle d'effet fenêtre. En s'appuyant sur les résultats de la simulation et en accordant les spectres expérimentaux aux spectres théoriques, on détermine les valeurs des paramètres photoélectriques (longueurs de diffusion, les vitesses de recombinaison en surface ... ) intervenant dans le rendement quantique

Ac transport losses calculation in a Bi-2223 current lead using thermal coupling with an analytical formula

Abstract—When a superconductor is fed with an alternating current, the temperature rise created by the losses tends to reduce the current carrying capacity. If the amplitude of the current exceeds the value of the critical current, then the losses become particularly high and the thermal heating considerable. In this paper, a numerical and an analytical model which allow to estimate AC transport losses are presented. These models, which use the expression of c ( ) and (), are available for any applied current (below and above c). The results are compared and the validity of the analytical model is considered. Then, the analytical formula allows to easily obtain the thermoelectric balance point of the system, when the losses and the temperature do not vary any more. Moreover, a maximum value of the current transport, beyond which the balance point does not exist, is detected. Indeed, when this maximum value is exceeded, the system is not stable and, say, superconducting current leads may quench. Index Terms—AC losses, Bi-2223 current lead, over current, quench, temperature dependence. I

Contact force computation based on BSIPs

International audienceno abstrac