Cartas desde la prisión a la fábrica : Un análisis de la correspondencia entre los obreros clasistas presos y los intelectuales de la secretaría de prensa del SiTraC

Desde 1970 los sindicatos de empresa Sindicato de Trabajadores de Concord (SiTraC) y Sindicato de Trabajadores de Materfer (SiTraM) protagonizan el proceso de radicalización de los trabajadores de las plantas automotrices FIAT en Córdoba. En marzo de 1971 las fuerzas militares intervienen el SiTraC y detienen a un grupo de delegados y miembros de la comisión directiva de ese sindicato, entre ellos Gregorio Flores y el abogado del sindicato, Alfredo Curutchet. En el presente trabajo analizamos las cartas que estos militantes intercambian con la secretaría de prensa del SiTraC, la ensayista Susana Fiorito, y con el escritor y militante del grupo maoísta Vanguardia Comunista Andrés Rivera. Varias de esas cartas traspasan la esfera privada para transformarse en documentos de la práctica política obrera. En efecto, ellas circulan de mano en mano dentro de las fábricas, son leídas en las asambleas obreras o incluso publicadas como cartas abiertas.Since 1970 the enterprise unions “Sindicato de Trabajadores de Concord” (SiTraC) and “Sindicato de Trabajadores de Materfer (SiTraM) protagonists in the process of radicalization of workers FIAT automobile plants in Cordoba. In March 1971 the military forces intervene and stop the SITRAC a group of delegates and members of the executive committee of the union, including Gregorio Flores and the union’s lawyer, Alfredo Curutchet. In this paper we analyze these militants exchanged letters with SITRAC press secretary, Susana Fiorito essayist, and writer and activist of the Maoist Communist Vanguard, Andrés Rivera. Several of these letters go beyond the private sphere to become working documents of political practice. Indeed, they circulate from hand to hand in the factories, are read in the workers’ assemblies or even published as open letters.Dossier: La correspondencia en la historia política e intelectual latinoamericanaFacultad de Humanidades y Ciencias de la Educació

Effect of glucocorticoids on the anti-cancer activity of chemotherapeutic agents in oral squamous cell carcinoma (OSCC) cells

Glucocorticoid hormones, such as hydrocortisone, are produced in the adrenal cortex and exert pleiotropic effects in peripheral tissues by regulating the expression of up to 10% of genes that are associated with broad spectrum of metabolic processes. In addition to the adrenal‐derived steroids, it is now recognised that peripheral tissues, such as the epidermis, may also act as steroidogenic organs. Recently has been shown that oral keratinocytes regulate the local concentration of active steroids as well as synthesize hydrocortisone de novo following stimulation with adrenocorticotropin hormone (ACTH). Synthetic corticosteroids are routinely administered during the treatment of several diseases, including pre-malignant and malignant conditions, particularly to alleviate side effects of chemotherapy. However, recent evidence suggests that corticosteroids may have tumour-promoting effects, particularly in epithelial neoplasms. The aim of this thesis was to assess the influence of the recently characterized tumor-associated glucocorticoid (GC) system on both cell proliferation and migration, and on the efficacy of chemotherapeutic agents in the treatment of oral squamous cell carcinoma (OSCC). The chemotherapeutic agents used in the present study were 5-fluorouracil (5-FU), an established drug for OSCC treatment and doxorubicin (DOXO), a potential candidate for the treatment of OSCC.Five different human malignant oral keratinocyte cell lines were selected: H314 / H357 / H400 / BICR16 / BICR56. The cell lines were treated with 5μM DOXO, 5 μg/mL 5-FU, 0,5 μg/mL Hydrocortisone (HC), 10 nM Adrenocorticotropic hormone (ACTH), 10 μM 5-pregnen-3-beta-ol- 20-one-16-alfa-carbonitrile (PCN) (a Glucocorticoid Receptor antagonist), 25 μM Fasentin (a novel inhibitor of glucose uptake that interacts with GLUT1), and 10 μM WZB-117 (an inhibitor of basal glucose transport; specific GLUT1 inhibitor). The cell lines were tested with both high (4.5 g/L) and low (1g/L) glucose mediums. Moreover in vitro wound healing assays were performed using the H357 human carcinoma cell line to assess cell migration. The literature review performed showed, in contrast to previous thought, how increased levels of autocrine, paracrine, and exogenous cortisol are important to tumor progression, as well as the expression of enzymes regulating the levels of tumor-derived cortisol. In the experimental part of the project we have clearly demonstrated, for the first time, the importance of cortisol on oral cancer cells ability to survive, migrate, and interestingly combat the effectiveness of chemotherapeutic agents. This effect would appear to be glucose dependent. Finally, Doxorubicin shows promise for the treatment of oral cancer. In conclusion, glucocorticoids promote oral carcinoma cell proliferation and migration implying an increase in cell invasiveness. This has important implications on the pharmacological use of glucocorticoids, as topical and systemic preparations, for the treatment of a wide variety of oral conditions and in combination with chemotherapy

Bottoming bending process assisted by electroplasticity

Este estudio reporta la influencia de los efectos atérmicos de la electroplasticidad en el proceso de doblado por estampa. Se fabrica un generador que generar pulsos de 300A y un ancho de 50μs. Los materiales estudiados fueron Al1050 y X5CrNi18-10. Se realizó un análisis por elementos finitos para caracterizar las diferentes fases del comportamiento mecánico de las probetas durante el proceso. Se estudió el efecto que tienen los pulsos de corriente sobre las fases mencionadas, prestando especial atención a las de recuperación elástica y la de máxima deformación plástica. Los resultados muestran que en el proceso asistido eléctricamente se reducen las fuerzas de doblado, hasta en un 18% en el aluminio y un 6% en el acero inoxidable. Además se observa que se reduce la recuperación elástica del material en un 21% y un 12% respectivamente. Se concluye que los efectos atérmicos de la electroplasticidad influyen en el proceso estudiado.The present study reports the influence of electroplasticity athermal effects on bottoming bending. To do so a short-time current pulse generator, capable of inducing 300A current pulses and a 50μs pulse duration, was manufactured. The materials studied were Al1050 and X5CrNi18-10. A finite element analysis was done in order to characterize the different phases of specimen mechanical behavior during bottoming bending. The influence of current pulses on different phases was studied, specifically on the elastic restoring force and the maximum plastic deformation phases. The results show that, compared to the conventional process, during the electrically-assisted process bending forces drop up to 18% in aluminium and 6% in stainless steel. The elastic restoring force is also reduced by 21% and 12% respectively. Therefore it can be concluded that the electroplasticity athermal effects have an influence on the bottoming bending process.Peer Reviewe

Vehículos recreativos para ejercitación variada

Este proyecto fue pensado para la ejercitación al aire libre en espacios verdes urbanos y suburbanos, públicos o privados. De este modo, se desarrollaron tres vehículos de propulsión a sangre, recreativos y de paseo, y con características pensadas para la familia.Facultad de Bellas Arte

Pareto-Optimization of HTS CICC for High-Current Applications in Self-Field

The ENEA superconductivity laboratory developed a novel design for Cable-in-Conduit Conductors (CICCs) comprised of stacks of 2nd-generation REBCO coated conductors. In its original version, the cable was made up of 150 HTS tapes distributed in five slots, twisted along an aluminum core. In this work, taking advantage of a 2D finite element model, able to estimate the cable's current distribution in the cross-section, a multiobjective optimization procedure was implemented. The aim of optimization was to simultaneously maximize both engineering current density and total current flowing inside the tapes when operating in self-field, by varying the cross-section layout. Since the optimization process involved both integer and real geometrical variables, the choice of an evolutionary search algorithm was strictly necessary. The use of an evolutionary algorithm in the frame of a multiple objective optimization made it an obliged choice to numerically approach the problem using a nonstandard fast-converging optimization algorithm. By means of this algorithm, the Pareto frontiers for the different configurations were calculated, providing a powerful tool for the designer to achieve the desired preliminary operating conditions in terms of engineering current density and/or total current, depending on the specific application field, that is, power transmission cable and bus bar systems

Experimental and numerical analysis of effect of cooling rate on thermal–microstructural response of spheroidal graphite cast iron solidification

This work presents an experimental and numerical study of the solidification process of an eutectic spheroidal graphite cast iron (SGI). The effect of the cooling rate on the thermal–microstructural response is particularly analysed. To this end, experiments as well as numerical simulations were carried out. The experiments consisted in a solidification test in a wedge-like casting such that different cooling rates were measured at specific positions along the part. A metallographic analysis was also performed in five locations of the sample with the aim of obtaining the number and size of graphite nodules at the end of the process. The numerical simulations were made using multinodular based and uninodular based models. These two models predicted similar results in terms of cooling curves and nodule counts. Besides, good experimental–numerical agreements were obtained for both the cooling curves and the graphite nodule counts

Joining metrics enhancement when combining FSW and ball-burnishing in a 2050 aluminium alloy

This report describes the effect of the ball-burnishing process on the mechanical properties of 2050 aluminium alloy that was previously friction stir welded. This process is a fast, environmentally-friendly and cost-effective surface treatment based on the plastic deformation of the surface irregularities. Consequently, residual stress, material hardening and micro-structural alterations are investigated to improve fatigue strength and wear resistance. The results show that the ball-burnishing treatment enhances the surface properties by increasing the material hardness about 37.5% and by decreasing the average surface roughness from 2.23¿µm to 0.06¿µm when a high pressure and a perpendicular burnishing is deployed. Additionally, in-depth compressive residual stresses are generated from -315¿MPa to -700¿MPa depending on the burnishing configuration. Finally, a numerical simulation of the material elastoplastic response is performed to analyze the residual stress continuity in the cross sectional area when using two radial feeds and burnishing pressures. In short, the present study helps to reduce time consumption by selecting the larger radial feed combined with a proper burnishing pressure to ensure the desired quality and compressive residual stress at the surface, which are indices of enhancing the fatigue strength at the nugget zone of the welded area.Postprint (author's final draft

Analysis of the Part Distortions for Inconel 718 SLM: A Case Study on the NIST Test Artifact

The present paper evaluates the misalignment and geometry distortion of the standard National Institute of Standards and Technology (NIST) test artifact in Inconel 718 alloy, when several layers with and without supports are employed to manufacture it by the Selective Laser Melting (SLM) process. To this end, a coordinate-measuring machine (CMM) is used to measure the geometrical distortion in each manufacturing configuration, following the same measurement protocol. The results show that the laser path strategy favors a thermal gradient which, consequently, induces geometrical distortions in the part. To prove this hypothesis, a numerical simulation is performed to determine the thermal gradient and the pattern of the residual stresses. It was found that the geometrical distortion certainly depends on the position of the feature position and laser strategy, where thermal cycles and residual thermal stresses had an impact in the end-part geometry, especially if a high strength-to-weight ratio commonly used in aeronautics is present.This work is supported by the Serra Húnter program (Generalitat de Catalunya) reference number [UPC-LE-304 (2018)] and by the Aeronautics Advanced Manufacturing Center (CFAA) in the JANO—Joint action toward digital transformation project framework. Diego Celentano acknowledges Pontificia Universidad Católica de Chile (PUC), Wallonie-Bruxelles International (WBI) and National Council for Scientific and Technological Research CONICYT (FONDECYT Projects No. 3180006 and 1180591) for the financial supports provided for this work

Secure Mobile IPv6 for Mobile Networks based on the 3GPP IP Multimedia Subsystem

The rapid spread of new radio access technologies and the consequent service opportunities have stimulated thetechnical and scientific community to investigate future evolution scenarios for 3rd Generation networks (3G), generically referred to as Beyond-3G or 4G. They are going to be characterized by ever stronger requirements for security, as well as the capability for the final users to experience continuous connectivity and uninterrupted services of IP applications as they move about from one access network to another. Key issues are: i) securityprovision for applications exchanging data in diverse wireless networks; ii) seamless mobility (handoff) between different coverage domains and, in case, access technologies. Since many proposals are based on the use of the Mobile IPv6 protocol, in this paper we analyze the security threats emerging from some Mobile IPv6 mechanisms for mobility management, and we propose a solution against such threats, under the assumption that both end users (mobile or not) are attached to a Mobile IPv6-enabled 3GPP IP Multimedia Subsystem network

Epitaxial growth of SrTiO3 films on cube-textured Cu-clad substrates by PLD at low temperature under reducing atmosphere

The growth of epitaxial {001} SrTiO3 (STO) on low-cost cube-textured Cu-based clad substrate at low temperature was carried out by means of pulsed laser deposition (PLD). STO film was deposited in one step under a reducing atmosphere (5% H2 and 95% Ar mixture) to prevent the oxidation of the metal surface. The optimization of PLD parameters leads to a sharpest biaxial texture at a temperature as low as 500 °C and a thickness of 500 nm with a (100) STO layer. The upper limit of highly textured STO thickness was also investigated. The maximum thickness which retains the best quality {001} texture is 800 nm, since the texture is preserved not only through the layer but also on the surface. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements showed that STO films are continuous, dense, and smooth with very low roughness (between 5 and 7 nm). This paper describes the development of STO layer by means of PLD in absence of oxygen throughout the process, suggesting an alternative and effective method for growing highly {001} textured STO layer on low-cost metal substrates