Sensitivity analysis on an AC600 aluminum skin component

New materials are been introduced on the car body in order to reduce weight and fulfil the international CO2 emission regulations. Among them, the application of aluminum alloys is increasing for skin panels. Even if these alloys are beneficial for the car design, the manufacturing of these components become more complex. In this regard, numerical simulations have become a necessary tool for die designers. There are multiple factors affecting the accuracy of these simulations e.g. hardening, anisotropy, lubrication, elastic behavior. Numerous studies have been conducted in the last years on high strength steels component stamping and on developing new anisotropic models for aluminum cup drawings. However, the impact of the correct modelling on the latest aluminums for the manufacturing of skin panels has been not yet analyzed. In this work, first, the new AC600 aluminum alloy of JLR-Novelis is characterized for anisotropy, kinematic hardening, friction coefficient, elastic behavior. Next, a sensitivity analysis is conducted on the simulation of a U channel(with drawbeads). Then, the numerical an experimental results are correlated in terms of springback and failure. Finally, some conclusions are drawn

Aloinjertos y autoinjertos de ligamento cruzado anterior de la rodilla: estudio experimental en el perro

Hemos realizado un trabajo de cirugía experimental en perros, en el que comparamos el comportamiento de los autoinjertos frescos de ligamento cruzado anterior de la rodilla (LCA), con lo aloinjertos crioconservados. Con la ayuda de una guía y trefinas, se extrae el LCA con sus inserciones, unido a un taco óseo en cada extremo. Los autoinjertos se reimplantan tras unos minutos en suero fisiológico. Los aloinjertos son sometidos a congelación y, almacenamiento a —80 °C y descongelación rápida, antes de su implantación. Se realiza una fijación de los tacos óseos con tornillos de esponjosa de 6,5 mm, lo que nos permite prescindir de la inmovilización. Los animales se sacrifican a las 3, 6, 12, 24 y 36 semanas, realizando estudio vascular con técnica de transparencia de tejidos de Spalteholz y estudios histológicos. Se demuestra que ambos injertos sufren los mismos procesos biológicos de reparación. Células mesenquimales indiferenciadas y brotes capilares del receptor, invaden los componentes del injerto; se produce una diferenciación polarizada a osteoblastos en el hueso y a fibroblastos en el ligamento, que por mecanismo de sustitución por yuxtaposición, restauran un LCA similar al normal, bien vascularizado. Esta remodelación llega a las zonas profundas, en los autoinjertos a las 12 semanas y en los aloinjertos a las 24 semanas. A las 36 semanas, ambos injertos están maduros. No ha habido rechazo inmunológico. En nuestra opinión el aloinjerto de LCA, con hueso en sus extremos, puede ser el sustituto ideal para las roturas de LCA.Experimental surgery was performed on the dog to compare the behavior of fresh autografts with freeze-stored allografts of the anterior cruciate ligament (ACL). In both cases, drill holes were made at the ACL insertion sites with a cannulated bit and the ligament with a plug of bone attached to each end was extracted with the aid of a guide wire. Prior to implantation, autografts were inmersed in a saline solution for a few minutes. Allografts deeply frozen to -80 °C with liquid nitrogen were quickly thawed before surgery. At implantation, the bone plugs at the ends of the ligament were firmly anchored with 6,5 mm. cancellous bone screws, so inmobilization of the animals was not necessary. Animals were killed at 3, 6, 12, 24 and 36 week after surgery. To study graft vascularity the tissue transparency technique developed by Spalteholz was employed. Both type of grafts underwent the same biological reconstruction process. Indifferentiated mesenchymal cells and capillar buds from the host tissues invaded the implant. Through a mechanism of creeping substitution induced by fibroblastic and osteoblastic differentiation, the grafts gradually took the apparence of normal, well-vascularized ACL. The remodeling process reached the innermost zones of the autografts in 12 weeks and the allografts in 24 weeks. Both type of groups showed a normal mature appearance 36 weeks after surgery. There were no signs of inmunological rejection. In our opinion, the ideal substitution for repair of ACL injurie could be an allograft of the same ligament, removed with bone attached to each end

Long-term safety and efficacy of trifarotene 50 μg/g cream, a first-in-class RAR-γ selective topical retinoid, in patients with moderate facial and truncal acne.

BackgroundTreatment for both facial and truncal acne has not sufficiently been studied.ObjectivesTo evaluate the long-term safety and efficacy of trifarotene in both facial and truncal acne.MethodsIn a multicentre, open-label, 52-week study, patients with moderate facial and truncal acne received trifarotene 50 μg/g cream (trifarotene). Assessments included local tolerability, safety, investigator and physician's global assessments (IGA, PGA) and quality of life (QOL). A validated QOL questionnaire was completed by the patient at Baseline, Week 12, 26 and 52/ET.ResultsOf 453 patients enrolled, 342 (75.5%) completed the study. Trifarotene-related treatment-emergent adverse events (TEAEs) were reported in 12.6% of patients, and none was serious. Most related TEAEs were cutaneous and occurred during the first 3 months. Signs and symptoms of local tolerability were mostly mild or moderate and severe signs, and symptoms were reported for 2.2% to 7.1% of patients for the face and 2.5% to 5.4% for the trunk. Local irritation increased during the first week of treatment on the face and up to Weeks 2 to 4 on the trunk with both decreasing thereafter. At Week 12, IGA and PGA success rates were 26.6% and 38.6%, respectively. Success rates increased to 65.1% and 66.9%, respectively at Week 52. Overall success (both IGA and PGA success in the same patient) was 57.9% at Week 52. At Week 52 visit, 92/171 (53.8%) patients who had completed their assessments had scores from 0 to 1 (i.e. no effect of acne on their QOL) vs. 47/208 (22.6%) patients at Baseline visit.ConclusionIn this 52-week study, trifarotene was safe, well tolerated and effective in moderate facial and truncal acne

U-drawing of Fortiform 1050 third generation steels. Numerical and experimental results

Elasto–plastic behavior of the third generation Fortiform 1050 steel has been analysed using cyclic tension–compression tests. At the same time, the pseudo elastic modulus evolution with plastic strain was analysed using cyclic loading and unloading tests. From the experiments, it was found that the cyclic behavior of the steel is strongly kinematic and elastic modulus decrease with plastic strain is relevant for numerical modelling. In order to numerically analyse a U-Drawing process, strip drawing tests have been carried out at different contact pressures and Filzek model has been used to fit the experimental data and implement a pressure dependent friction law in Autoform software. Finally, numerical predictions of springback have been compared with the experimentally ones obtained using a sensorized UDrawing tooling. Different material and contact models have been examined and most influencing parameters have been identified to model the forming of these new steels

Técnicas de biopsia para el diagnóstico de lesiones mamarias no palpables

Facing a non-palpable mammary lesion requiring a diagnostic biopsy, consideration must be given to the most suitable guiding method for obtaining the latter. Three methods are employed at present: stereotaxy (basically in cases of microcalcifications), echography (above all in the nodules), and magnetic resonance (for lesions not made visible through the previous systems). The next step is to select the most suitable biopsy technique. The most classical and reliable technique is the surgical biopsy with prior marking using a metallic harpoon, but, besides its high cost, it has the drawback of being an aggressive technique for the diagnosis of a benign pathology. Numerous systems of puncture have been developed as alternatives. Puncture with a fine needle is technically simple to carry out and can provide good results in the mammary nodules, but the existence of positive and negative false results has progressively limited its use. As an alternative, the systems of biopsy with a broad needle have made it possible to obtain multiple cylinders with a high diagnostic reliability, above all in the case of mammary nodules. However, their use in microcalcifications continues to show negative false results. The arrival of systems of vacuum-assisted biopsy has made it possible to obtain cylinders of greater quality, above all in cases of microcalcifications. Finally, the systems of percutaneous resection biopsy by means of cannulas with a diameter of 22 mm make it possible to completely extract lesions of a size below that of the cannula, with a reliability similar to that of the surgical biopsy

Ultracold Neutral Plasmas

Ultracold neutral plasmas are formed by photoionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1-1000 K and the ion temperature is around 1 K. The density can approach $10^{11}$ cm$^{-3}$. Fundamental interest stems from the possibility of creating strongly-coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr$^+$ ${^2S\_{1/2}} -> {^2P\_{1/2}}$ transition at 422 nm, depict the density profile of the plasma, and probe kinetics on a 50 ns time-scale. The Doppler-broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photoionization.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France