Publications

Une étude stratigraphique et sédimentologique a été réalisée sur une terrasse alluviale de la région d’Oued El Hay, au sud de Batna (NE Algérie). Les structures sédimentaires observées sont principalement des zones d’érosion, des zones inondables, des figures en biseau et des variations d’épaisseur associées à des joints de stratification. Du point de vue sédimentologique, les sédiments sont dominés par des fractions argilo-limono-sableuses, suivies par des fractions de gravier et de cailloux. Les teneurs modérées en CaCO3 résultent de la dissolution des reliefs calcaires à proximité (calcaire crétacé) associée à l’augmentation de la température et l’humidité du milieu. L’observation morphoscopique de grains de quartz avec une loupe binoculaire permet d’offrir une évolution plus ou moins importante, car ils sont souvent émoussés ou sous-arrondis. L’étude sédimentologique a été réalisée sur 16 échantillons prélevés systématiquement du haut vers le bas de la coupe stratigraphique. L’examen de la taille brute de la fraction inférieure à 2 mm a permis d’individualiser 03 niveaux dans des couches sédimentaires, certaines fractions grossières riches (gravier, cailloux et blocs) alternant avec des couches riches en sable et en limon. Le pourcentage de fraction d’argile est dominant et reste pratiquement constant presque tout au long de la section stratigraphique.

In this paper, heat transfer analysis during cutting 2024-T351 aluminium alloy with carbur tungsten (25° rake angle) and especially in 2, 3D orthogonal cutting operation numerically was performed. The assembly was modelled, meshed and analysed using commercial computational tool ABAQUS EXPLICIT. The parameters to be varied are depth of cut and impact speed, the thermal boundary conditions are adiabatic, the thermal contact between tool and workpiece is imperfect and the following method is Lagrangian, the results were well visualized and compared with literature, [23] and are in good agreement with reality of cutting. It was found that maximum temperature turn around 400°C when cutting and it is located in chip formation on the other hand, heat conduction with impact speed were two antagonist phenomenon, in other terms, increase in impact speed has less effect on heat transfer and in conduction espescialy.

Away from what we may believe, mastering writing and reading in English is far from being learners’ unique target in ESP instruction (English for Specific Purposes). Students want to understand what they hear in English and speak fluently in a way closer to that of English native speakers. However, the complexity which generally sketches the understanding and production of authentic English spoken language, in addition to teachers’ poor consideration of those aspects, lead learners to experience anxiety, lack of self-confidence, lack of motivation and, obviously, poor feedback. As a result, the English language instruction becomes so weighty for both teachers and learners. These concerns led us to a descriptive research design to shed the light on the ESP instruction’s actuality in the Faculty of Human and Social Sciences University of Batna1. A questionnaire was introduced to portray our first year PhD students' weaknesses in terms of English speaking and listening abilities. Also, we aimed to depict their attitudes towards introducing films in English as a support for their learning. Students’ positive positions on the introduction of films in English into the classroom leads us to strongly recommend them as quite supportive and efficient pedagogical means in ESP learning as well as teaching.

The main purpose for wireless sensor networks is especially for data collection. Nevertheless, since the sensors are mostly immobile, the operation of transferring data they captured to the base station is a critical task since the exchange environment is unstable. Our approach consists in injecting mobile relay nodes whose mission is mainly to maximize the lifetime of the network, also to provide connectivity between any sensor and the base station, and to minimize the latency of receiving data sent to the base station. Smart mobility is the key for our approach to ensure reliability by forming a virtual mobile circle using relay nodes. We have proved formally and by simulation the effectiveness of our approach, the obtained results prove the efficiency of our approach.