Analysis of the Surface Integrity in Cryogenic Turning of Ti6Al4 v Produced by Direct Melting Laser Sintering

The Ti6Al4V is widely utilized in the biomedical field thanks to its high biocompatibility, however, due to its low machinability, is classified as a difficult-to-cut material. With the goal of improving the surface quality of biomedical components made of Ti6Al4V produced by the DMLS additive manufacturing technology and later on machined, Liquid Nitrogen was tested as a coolant in semi-finishing turning. The integrity of the machined surfaces is evaluated in terms of surface defects and topography as well as residual stresses. The obtained results showed that the cryogenic machining assured a lower amount of surface defects and higher values of the residual compressive stressed compared to dry cutting, but a general worsening of the surface topography was detected

Extended Double Lattice BRST, Curci-Ferrari Mass and the Neuberger Problem

We present Extended Double BRST on the lattice and extend the Neuberger problem to include the ghost/anti-ghost symmetric formulation of the non-linear covariant Curci-Ferrari (CF) gauges. We then show how a CF mass regulates the 0/0 indeterminate form of physical observables, as observed by Neuberger, and discuss the gauge-parameter and mass dependence of the model.Comment: Prepared for 7th Conference on Quark Confinement and the Hadron Spectrum, Ponta Delgada, Azores, Portugal, 2-7 Sep 2006. 3p

Gauge fixing and BRST formalism in non-Abelian gauge theories

In this Thesis we present a comprehensive study of perturbative and non-perturbative non-Abelian gauge theories in the light of gauge-fixing procedures, focusing our attention on the BRST formalism in Yang-Mills theory. We propose first a model to re-write the Faddeev-Popov quantisation method in terms of group-theoretical techniques and then we give a possible way to solve the no-go theorem of Neuberger for lattice Yang-Mills theory with double BRST symmetry. In the final part we present a study of the Batalin-Vilkovisky quantisation method for non-linear gauges in non-Abelian gauge theories.Comment: Jan 2007. 146pp. Ph.D. Thesis (Advisor: L. von Smekal and A.G. Williams

Finite element simulation of semi-finishing turning of Electron Beam Melted Ti6Al4V under dry and cryogenic cooling

open6noIn the last few years, important step forwards have been made on Finite Element Simulation of machining operations. Wrought Ti6Al4V alloy has been deeply investigated both numerically and experimentally due to its wide application in the industry. Recently, Additive Manufacturing technologies as the Electron Beam Melting and the Direct Melting Laser Sintering are more and more employed in the production of biomedical and aeronautical components made of Ti6Al4V alloy. Fine acicular microstructures are generated by the application of additive manufacturing technologies, affecting the mechanical properties and the machinability. By the consequence, this peculiarity has to be considered in modelling the material behaviour. In this work, a numerical analysis of cylindrical external turning on Electron Beam Melted (EBM) Ti6Al4V alloy is presented. A Johnson-Cook constitutive equation was implemented as a flow stress model and adapted with respect to the wrought Ti6Al4V alloy. The model was calibrated and validated through the cutting forces and temperatures measurements acquired under dry and cryogenic lubricating conditions.openBordin, A; Imbrogno, S.; Rotella, G.; Bruschi, S.; Ghiotti, A.; Umbrello, D.Bordin, Alberto; Imbrogno, S.; Rotella, G.; Bruschi, Stefania; Ghiotti, Andrea; Umbrello, D

¿Políticas públicas con perspectiva de género?

El desarrollo de las políticas públicas debe ser entendido desde su contextualización. Cada momento socio-histórico ha sido caracterizado por un proyecto político, vinculado a un modelo económico, social y educativo determinado, efectuando planes y programas según su concepción de sujeto. Si se entiende que la relación de género señala una relación social, en tanto construcción política y cultural, dicha concepción posibilita la emergencia de procesos, discursos y prácticas instituyentes en busca de un proyecto societario emancipador. En tal sentido, considerando la categoría género-sexo y su impacto en las políticas públicas, nos preguntamos:¿Por qué la diferencia sexual todavía implica desigualdad entre los géneros?¿Qué concepciones y representaciones sostienen el poder vinculado a lo masculino en el territorio y en las políticas públicas? ¿Existe una nueva institucionalidad en las políticas públicas? Para ello, desde la aplicación de una metodología cualitativa, analizamos el Programa Ellas Hacen, considerando desde la voz de las y los sujetos vinculadas/os al mismo, mediante la comprensión del movimiento histórico, la indagación de lo contradictorio y problemático en el campo de las políticas públicas, y los impactos en la vida cotidiana de las mujeres. Así nuestro objetivo es analizar los escenarios actuales referidos a las políticas dirigidas a las mujeres y sus tensiones, para lograr una igualdad de oportunidades entre géneros en el territorio.Fil: Ghiotti, Cintia . Universidad Nacional de CuyoFil: Medina, Roxana . Universidad Nacional de Cuy