Vapor diffusion was studied from volatile liquids of three brands of UAE gasoline: Super, Special, E+ and a mixture of these brands. The studying was conducted at 50 oC which represent the highest atmospheric temperature in UAE. The diffusion coefficients of Super gasoline ( 98 Octane number) was equal to 6.348 E-07, for special gasoline ( 95 octane number) equal to 7.353 E-07, for E+ (octane number 91) equal to 2.169 E-06, and the mixture of these three brands is 6.302E-07 m2/s. This concluded that super gasoline which has the higher octane number, minimum density, and higher heat of combustion has the lowest diffusion coefficient with air

The initial uses of ultrasound waves in the medical field were limited to the thermal ablation of solid tumors and as a diagnostic tool. Recent advances at the preclinical stage have allowed the use of ultrasound as a powerful tool to improve drug delivery when the agent is administered encapsulated inside a nanoparticle. This spatial and temporal control of drug release, using a non-invasive modality, is a promising approach to decrease the side effects of conventional chemotherapy in cancer treatments, as it reduces the interaction of the anti-neoplastic agent with healthy tissues. In this review, we explain the physics of ultrasound, introduce and discuss several examples on the use of nanoparticles as drug carriers, with a focus on liposomes. Examples of in vitro and in vivo studies are presented and discussed.

Les aciers inoxydables ont de nombreuses applications dans plusieurs domaines. Actuellement, ils figurent parmi les principaux matériaux utilisés en chirurgie orthopédique. Comme ces implants sont destinés à être utilisés à l'intérieur même du corps humain, ils doivent par conséquent être non toxiques, fiables, le plus sécuritaire possible, et avoir de bonnes performances. Ces matériaux peuvent, sous certaines conditions, perdre de façon importante leurs qualités mécaniques, ce qui se traduit dans certains cas par des ruptures inattendues pouvant entraîner des complications médicales importantes. Le but de ce travail est d'étudier l'action de l'organisme sur l'implant : contraintes statiques, fatigue et corrosion. Cette étude est menée grâce à la microscopie électronique à balayage munie d'une microsonde X. Ce travail vise en fait à établir un critère de durée de vie de l'implant et à expliquer les défaillances qui apparaissent après implantation. La zone étudiée est choisie après examen morphologique externe de la pièce. Notre attention est particulièrement attirée par l'état de surface, et généralement par les points anguleux ainsi que par les changements de courbure qui sont des lieux de concentrations de contraintes.Abstract: Stainless steels have numerous applications in many domains. More specifically, they are one of the main materials used in orthopedic surgery. Because they are implanted in the human body, they must be nontoxic, reliable, as safe as possible, and perform well. Under certain circonstances, they loose some of their mechanical properties. This may translate into sudden breaks, possibly with important medical complications. The present work studies how the living organism affects the implant: static constraints, wear and tear, and corrosion. We use scanning electronic microscopy with an X probe. Our purpose is to determine the criteria of durability and to explain how a weakness develops after implantation. An external morphologic examination helps determine the area selected for the study. We are specially interested in the state of the surface of the material and, generally, by the angular points and the regions with curvature variations where strains tend to concentrate.[Journal translation] Reçu le 16 novembre 1998. Accepté le 21 mai 1999.