Simulation numérique de l'interaction fluide-structure d'un profil d'aile équipé de volets élastiques

L'étude du contrôle passif de décollement d'un écoulement instationnaire est abordée. L'interaction entre l'écoulement et un ensemble de volets élastiques placés sur l'extrados d'un profil d'aile a été mis en évidence par simulation numérique à l'aide de la suite ANSYS. La résolution de ce problème a été effectuée par une approche partitionnée bidirectionnelle par le couplage des codes ANSYS Mechanical et ANSYS Fluent. Il s'agit d'une aile de type NACA0012 équipé de 8 volets de même longueur équitablement répartis sur l'extrados. L'incidence du profil est fixé à 20° pour un nombre de Reynolds de l'écoulement de 3,42 105 . Les volets libres de se braquer spontanément ont un module d'Young de 5 106 Pa. Lors de l'Interaction Fluide-Structure la déformation instationnaire des volets élastiques entraîne une modification de la structure globale de l'écoulement autour de l'aile entrainant un gain important de portance atteignant les 50%

Development of Diamond Composite Electrode for Anodic Oxidation of Organic Pollutants

Abstract Nano-diamond composite electrode was prepared and used as anode for anodic oxidation process for organic chemicals. Electrochemical techniques such as impedance and cyclic voltammetry have been used to characterize the diamond composite electrode properties. The oxidation power of the electrode was 0.8 V vs. Ag/AgCl, the charge transfer rate was 12.1 Ohm, and the double layer capacitance was less than 1 μF. The anodic oxidation behavior of p-benzoquinone, 2-chlorophenol, and phenol over diamond composite electrode were investigated by cyclic voltammetry in 0.1 M H2SO4 (pH 3) solution and 0.25 M Na2SO4 (pH 6.8) solution. Results marked that the electro-oxidation of p-benzoquinone was more active than phenol and 2-chlorophenol in the both solutions. The performance of the diamond composite electrode during incineration of 200 mg/L p-benzoquinone, 2-chlorophenol, phenol were investigated in an aqueous solution of pH 3 and pH 6.8 with 0.25 M Na2SO4 as the supporting electrolyte and applied current density of 40 mA/cm2. Results showed that the degradation rate of benzoquinone was faster than 2-chlorophenol and phenol in both different pH solutions. Moreover, the benzoquinone degradation rate was enhanced at high pH solution, on the contrary of that of 2-chlorophenol and phenol were clearly favored in acid medium

Use of Ustekinumab in the Treatment of Libyan Psoriasis Vulgaris Patients

Introduction. Psoriasis is a relatively common chronic inflammatory disease. It clinically manifests as raised, well defined erythematous plaques with irregular borders and silvery scales. Psoriasis appears to be mediated by abnormal immune system functioning, including T lymphocyte and macrophage activation and release of various cytokins, such as interleukin 12 (IL-12) and IL-23. Recently a new biologic agent Ustekinumab has been used in the treatment of psoriasis. Our aim in this study was to assess the efficacy and tolerability of ustekinumab in moderate to severe psoriasis vulgaris and to observe and report any adverse reaction

Coconut waste as a source for biodiesel production

Biodiesel industry needs a cheaper and economical viable raw material that can replace the currently used vegetable oil. Obtaining cheaper raw materials are one of the continuous targets of many biodiesel producing facilities since 70 to 95 % of the production costs are attributed to raw materials. One of the main options is to use waste material from animal and plant sources. In this study, coconut waste is used to produce biodiesel using methanol and KOB. The oil content in coconut waste varies from 10-11 wt%. The highest yield, 64 % is achieved with 5 wt% of KOB within 3 hr by mixing raw material and methanol

Coconut waste as a source for biodiesel production

Biodiesel industry needs a cheaper and economical viable raw material that can replace the currently used vegetable oil. Obtaining cheaper raw materials are one of the continuous targets of many biodiesel producing facilities since 70 to 95 % of the production costs are attributed to raw materials. One of the main options is to use waste material from animal and plant sources. In this study, coconut waste is used to produce biodiesel using methanol and KOB. The oil content in coconut waste varies from 10-11 wt%. The highest yield, 64 % is achieved with 5 wt% of KOB within 3 hr by mixing raw material and methanol

Cancers after Renal Transplantation: Multicenter Experience

Renal transplant recipients are at higher risk of certain tumors such as lymphomas and skin cancers and than the general and dialysis populations. We retrospectively studied the prevalence of tumors in adult renal transplant recipients in four Tunisian centers of transplantation in Tunis, Monsatir and Sfax from January 1986 to January 2005. The study included 36 patients; 19 men and 17 women with a mean age of 34.6 years (range from 18-54 years). The mean time since dialysis to transplantation was 43 months (6-131months). Maintenance therapy was based on calcineurin inhibitors (CNI) in 86 % of cases, on antimetabolites and corticosteroids in 100 % of cases. Anti-thymoglobulin was administered in a mean course of 12.4 days in 78 % of the patients. Acute rejection occurred in 25 cases and was treated with polyclonal or monoclonal antibodies on 40 % of cases. Incidence of cancer among our population was 7 % and occurred after a mean period of 54 months of transplantation (range from 4-160 months). Eighty three percent of the tumors were solid, and the rest were in the skin. Kaposi sarcoma formed 41.6 % and non-Hodgkin or Hodgkin lymphoma 27.7 % of the solid tumors, while spinocellular carcinoma formed 83% and basocellular carcinoma 17% of the skin tumors. Switching CNI to sirolimus in 8.3% cases was associated with a favorable outcome. Mortality was the outcome in 33.3% of the patients with cancer, while partial or complete regression of cancers was observed in 55.5% cases after decreasing the doses of the immunosuppressive medications. We conclude that post renal transplant cancer is mainly characterized by the predominance of Kaposi sarcoma favored by solar exposure and rigorously induced and maintained immunosuppression. Careful follow-up may results in early inter-vention and decrease mortality