Nouvelles données à propos du Quaternaire et de la tectonique récente dans la chaîne de Metlaoui (sud-ouest de la Tunisie)

Five quaternary levels, dated from middle Pleistocene to the historic period, are identified on the south piedmont of the Metlaoui range. After the post-villafranchian compressional phase, an extensive tectonic affects the quaternary layers in the middle and the late upper Pleistocene.Cinq niveaux quaternaires, datant du Pléistocène moyen à la période historique, sont identifiés sur le piémont méridional de la chaîne de Metlaoui. Postérieurement à la phase de compression post-villafranchienne, une tectonique distensive affecte les dépôts quaternaires au Pléistocène moyen et à la fin du Pléistocène supérieur.Ben Ouezdou H., Zargouni F. Nouvelles données à propos du Quaternaire et de la tectonique récente dans la chaîne de Metlaoui (sud-ouest de la Tunisie). In: Méditerranée, troisième série, tome 64, 2-1988. Évolution des paysages tunisiens au cours du Quaternaire, sous la direction de J.-L Ballais et J. Vaudour. pp. 22-26

Compliant Contact of Walking Robot Feet

The feet/ground interaction is one of the major problem in the context of dynamic simulation for walking devices. We focus here about the phenomenon of contact. This paper describes a general model for dynamic simulation of contacts between a walking robot and ground. This model considers a force distribution and uses an analytical form for each force depending only on the known state of the robot system. The simulation includes all phenomena that may occur during the locomotion cycle : impact, transition from impact to contact, contact during support with static friction, transition from static to sliding friction and sliding friction. Some examples are presented to show the use of this contact model for the simulation of the feet/ground interaction during a walking gait. 1 Introduction Design of structures and gaits requires an iterative analysis tool able to simulate accurately the dynamic behavior of walking machines which are very large and complex systems. Therefore it is essen..

Model-Based Gripper Design

: This paper presents a computer-aided design optimization system dedicated to robot grippers. This system, developed on a commercial available robotic CAD system ACT 1 , integrates an Expert System to provide an interactive high-level decision support for novel design. Two function problems employed for accessibility analysis and grasp selection in the preliminary design are summarized in this paper. An example of their use in a practical case, the assembly of exhaust-pipes in car industry, concludes this paper. 1 Introduction Grippers are key components in robotized assembly systems. They can represent a significant part of robotized cell cost. Consequently, it is highly wished to increase their flexibility (i.e. their ability to handle all the variants of the workpiece family). This flexiblity in grasp is rarely reach by the use of industrial systems and supposes a re-design or at least an adaptation of existing grippers. This design operation requires proper consideration of sev..

Investigation of the early effectiveness of an amino-alcohol based corrosion inhibitor using simulated pore solutions and mortar specimens

This study was carried out to determine effective modes of use of an amino-alcohol based mixed corrosion inhibitor. It was tested in fresh pore concrete simulating solutions. Their compositions and the practical procedures were chosen in order to simulate both curative and preventive modes of use. Effectiveness of the corrosion inhibitor was investigated through corrosion potential measurements, polarisation curves and microscopic observations. The best inhibiting capacity was noted when the inhibitor was introduced in the solution before the contamination with chlorides. Using this inhibitor as a curative mean gave a reduced effect especially when chlorides were present in the simulated pore solutions. The curative mode was tested in the case of mortar specimens. Its efficiency was demonstrated even in the case of chloride presence. For the mortar specimens, the reinforcement electrochemical behaviour was assessed through the corrosion potential measurements and the study of current density evolution

Modelisation dynamique de principe de locomotion de robots mobiles et commandes associees

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : AR 14847 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc