Geomatic Approach and Geophysical Interpretation of the Hydrogeological Basin of the Hassi Naga Region (Algerian Southwest)

In this work, we propose a model of Geomatics in the Hassi Naga region, which is located in the Hamada of Tindouf, southwestern Algeria, about 70 km to the northwest of the region. This approach is based on prospecting and thematic analysis of the distribution of Geoelectrical measurements in order to better estimate and manage the Hydrogeology of this region of the Tindouf basin. The results of the geophysical survey allow us to design a complete model that meets the needs of Hydrogeology, whose methodology we have applied consists of decomposing our subject into three classes of entities: Geomatic, geophysical and hydrogeological, discovering the relational links, doing the thematic analysis and ending with results that help to solve the problem of water (Hydrogeology) of the area studied

Geo Electric Study in Hydrogeology According to the Axis Hassi Naga – Hassi Khebi of Tindouf (Southwestern Algeria)

The hydrogeological environment of the Saharan North East region of Tindouf is of utmost interest, particularly in agriculture. In fact, exploitation and exploration processes must be analysed to ensure sufficient water production. This study demonstrates the value of spatial processing and exploitation of geoelectric and geological data in the study area and facilitates interpretation. The results of the electrical survey and the spatial analysis of the data allowed us to design a complete model that met the needs of hydrogeology. The applied methodology consists in breaking down our subject into three (3) classes of entities: geomatics, geophysics and hydrogeology. Synthetic mapping based on continuity is the result of studying two sites (Hassi Naga and Hassi Khebi) for geological analysis. Knowing that the electrical resistivity is between 0 and 3000 Ohm-meter, we were able to construct thematic maps showing the spatial distribution of the facies and the probable positions of the boreholes. The study provided with a geo-spatial model highlighting the impact of measurements in hydrogeology of the area considered that was called SIHE (Information System for Environmental Hydrogeology)

Protoplast fusion enhances antagonistic activity in Trichoderma spp

Abstract: Genus Trichoderma is one of the most important filamentous fungi used as a biocontrol agent. Because of the absence of sexual reproduction in this fungus, other methods of genetic improvement have been developed such as proptoplast fusion to enhance its bicontrol potential. Therefore the objectives of this study were; 1) protoplast fusion and regeneration of two fungicide tolerant mutants of Trichoderma viride and T. harzianum 2) using ISSR for fingerprinting of inter-specific protoplast fusants and 3) assessment of antagonistic ability of Trichoderma fusants against three soil born diseases. Protoplast was isolated from two fungicide tolerant mutants PTv-V and PTz-F of Trichoderma,. The frequency of fusion tolerant to both pesticides was about 0.3 % and eight fusants were selected for further studies. In fusant stability experiments, only five of these fusants were the result of nuclear fusion of parental cells. Molecular characterization of two stable fusants using ISSR indicated the presence of novel fragments which may be due to recombination events between parents. In dual culture biocontrol experiments, five selected fusants showed growth inhibition against three pathogens namely; Rhizoctonia solani, Fusarium oxysporum and Pythium ultimum.. However, Fus 7 indicated the best ability of inhibition the growth of the three pathogens. In greenhouse experiments Fus 7 demonstrated a great ability to reduce tomato damping off of the three pathogens in the presence of the two fungicides understudy. It was concluded that, the protoplast fusion is a powerful tool to enhance the biocontrol ability of Trichoderma sp. against diseases

Optimization of thermostable proteases production under agro-wastes solid-state fermentation by a new thermophilic Mycothermus thermophilus isolated from a hydrothermal spring Hammam Debagh, Algeria

The present work investigates for the first time the presence and isolation of the thermophilic fungi from hydrothermal spring situated at the locality of Guelma, in the Northeast of Algeria. The production of the thermostable proteases and the optimization of culture conditions under agro-wastes solid-state fermentation to achieve optimal production capacity were explored. A statistical experimental approach consisting of two designs was used to determine the optimum culture conditions and to attain the greatest enzyme production. Besides, different agricultural wastes were initially evaluated as a substrate, whereby wheat bran was selected for enzyme production by the isolate under solid-state conditions. The isolate thermophilic fungi were identified as Mycothermus thermophilus by sequencing the ITS region of the rDNA (NCBI Accession No: MK770356.1). Among the various screened variables: the temperature, the inoculum size, and the moisture were proved to have the most significant effects on protease activity. Employing two-level fractional Plackett?Burman and a Box?Behnken designs statistical approach helped in identifying optimum values of screened factors and their interactions. The analysis showed up 6.17-fold improvement in the production of proteases (~1187.03 U/mL) was achieved under the optimal conditions of moisture content 47%, inoculum 5 ? 105 spores/g, and temperature at 42 C. These significant findings highlight the importance of the statistical design in isolation of Mycothermus thermophilus species from a specific location as well as identifying the optimal culture conditions for maximum yield.Scopu

Sub-ppm NO2 sensing in temperature cycled mode with Ga doped ZnO thin films deposited by RF sputtering

International audienceIn this work Ga doped ZnO thin films have been deposited by RF magnetron sputtering onto a silicon micro-hotplate and their structural, microstructural and gas sensing properties have been studied. ZnO:Ga thin film with a thickness of 90 nm has been deposited onto a silicon based micro-hotplates without any photolithography process thanks to a low cost and reliable stencil mask process. Sub-ppm sensing (500 ppb) of NO2 gas at low temperature (50 °C) has been obtained with promising responses R/R0 up to 18. Micro-hotplates have been prepared using photolithographic process. The system is composed by a heating element and sensing electrodes. They are both integrated in membrane in order to have a localized heating and sensing spot onto which the sensitive thin film is deposited. The microhotplates can operate with low consumption and can heat up to 500 °C with a good stability. This system has been already published in [1]. The use of lift-off process to restrict the deposition of the thin film onto central electrodes can lead to the dissolution and/or contamination of the sensitive layer. That's why the photolithographic method was avoided and a stencil mask process was used

Mission archéologique de Madâ'in Sâlih (Arabie Saoudite) : Recherches menées de 2001 à 2003 dans l'ancienne Hijrâ des Nabatéens

84 pagesInternational audienceThis contribution presents the preliminary results of the Madâ'in Sâlih archaeological project, which started in 2001 and which, in December 2004, completed its fourth field season. The aims of this five-year project are a systematic recording of the archaeological remains at the site as well as an analysis of its agricultural potential. The former include not only the tombs, sanctuaries, wells, quarries, walls, buildings, etc., but also the inscriptions written in various scripts and languages. Parallel to this exploration of what is visible on the surface, an extensive geophysical survey was undertaken in the so-called residential area, in the central part of the site, in order to obtain an image of the sub-surface remains. This contribution begins with a presentation of the sources, followed by a brief history of the exploration of Madâ'in Sâlih. The focus is on the conditions which allowed this project to be established as well as the problematics which guided it. J.-B. Rigot then presents his analysis of the agricultural potential of the site, demonstrating the existence, in antiquity, of a large oasis. Finally, a preliminary description of the main components of the sites: the necropoleis, the sanctuaries and the residential area, is given