Determination and Analysis of Residual Stresses Induced by High Speed Milling Using a Micro-indent Method

Abstract: The purpose of this work is to determine and analyze residual stress normal components and anisotropy degrees introduced by high-speed milling in specimens of AA 6082-T6 and AA 7075-T6 aluminum alloys. At each machined sample, the climb and conventional cutting zones were evaluated and compared. This paper includes a comprehensive study of thermal and mechanical effects associated with the residual stress introduction. For normal components determination, an optimized micro-indent method was used. Each measurement sequence from this approach was performed using a high accuracy measuring machine and classified according to thermal deviations measured. The residual displacements were determined with an absolute error down to ±300 nm. The normal components analysis allowed to infer the strong influence of the rolling process previous to high-speed milling and besides, the stress levels associated with thermal effects (higher in AA 7075-T6). Finally, the lower residual stress anisotropy degrees in both materials observed in the conventional cutting zone would indicate more homogenous local plastic stretching in this region for all planar directions.Research Journal of Applied Sciences, Engineering and TechnologyFil: Vottero, S. Departamento de Ingeniería Electromecánica-Departamento de Ingeniería Industrial, Facultad Regional Rafaela, Universidad Tecnológica Nacional, Acuña 49, 2300 Rafaela, Argentina.Fil: Mammana, C. A. Departamento de Ingeniería Electromecánica-Departamento de Ingeniería Industrial, Facultad Regional Rafaela, Universidad Tecnológica Nacional, Acuña 49, 2300 Rafaela, Argentina.Fil: Guidobono, A. P. M. División Metrología Dimensional, Centro Regional Rosario (INTI), Ocampo y Esmeralda, 2000 Rosario, Argentina.Peer Reviewe

Determination and Analysis of Residual Stresses Induced by High Speed Milling Using a Micro-indent Method

The purpose of this work is to determine and analyze residual stress normal components and anisotropy degrees introduced by high-speed milling in specimens of AA 6082-T6 and AA 7075-T6 aluminum alloys. At each machined sample, the climb and conventional cutting zones were evaluated and compared. This paper includes a comprehensive study of thermal and mechanical effects associated with the residual stress introduction. For normal components determination, an optimized micro-indent method was used. Each measurement sequence from this approach was performed using a high accuracy measuring machine and classified according to thermal deviations measured. The residual displacements were determined with an absolute error down to ±300 nm. The normal components analysis allowed to infer the strong influence of the rolling process previous to high-speed milling and besides, the stress levels associated with thermal effects (higher in AA 7075-T6). Finally, the lower residual stress anisotropy degrees in both materials observed in the conventional cutting zone would indicate more homogenous local plastic stretching in this region for all planar directions.Fil: Vottero, S.. Universidad Tecnológica Nacional. Facultad Regional Rafaela; ArgentinaFil: Diaz, Felipe Victor. Universidad Tecnológica Nacional. Facultad Regional Rafaela; ArgentinaFil: Mammana, Claudio Alejandro. Universidad Tecnológica Nacional. Facultad Regional Rafaela; ArgentinaFil: Guidobono, A.. Instituto Nacional de Tecnología Industrial; Argentin

Psychological treatments and psychotherapies in the neurorehabilitation of pain. Evidences and recommendations from the italian consensus conference on pain in neurorehabilitation

BACKGROUND: It is increasingly recognized that treating pain is crucial for effective care within neurological rehabilitation in the setting of the neurological rehabilitation. The Italian Consensus Conference on Pain in Neurorehabilitation was constituted with the purpose identifying best practices for us in this context. Along with drug therapies and physical interventions, psychological treatments have been proven to be some of the most valuable tools that can be used within a multidisciplinary approach for fostering a reduction in pain intensity. However, there is a need to elucidate what forms of psychotherapy could be effectively matched with the specific pathologies that are typically addressed by neurorehabilitation teams. OBJECTIVES: To extensively assess the available evidence which supports the use of psychological therapies for pain reduction in neurological diseases. METHODS: A systematic review of the studies evaluating the effect of psychotherapies on pain intensity in neurological disorders was performed through an electronic search using PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews. Based on the level of evidence of the included studies, recommendations were outlined separately for the different conditions. RESULTS: The literature search yielded 2352 results and the final database included 400 articles. The overall strength of the recommendations was medium/low. The different forms of psychological interventions, including Cognitive-Behavioral Therapy, cognitive or behavioral techniques, Mindfulness, hypnosis, Acceptance and Commitment Therapy (ACT), Brief Interpersonal Therapy, virtual reality interventions, various forms of biofeedback and mirror therapy were found to be effective for pain reduction in pathologies such as musculoskeletal pain, fibromyalgia, Complex Regional Pain Syndrome, Central Post-Stroke pain, Phantom Limb Pain, pain secondary to Spinal Cord Injury, multiple sclerosis and other debilitating syndromes, diabetic neuropathy, Medically Unexplained Symptoms, migraine and headache. CONCLUSIONS: Psychological interventions and psychotherapies are safe and effective treatments that can be used within an integrated approach for patients undergoing neurological rehabilitation for pain. The different interventions can be specifically selected depending on the disease being treated. A table of evidence and recommendations from the Italian Consensus Conference on Pain in Neurorehabilitation is also provided in the final part of the pape

A new variant in signal peptide of the human luteinizing hormone receptor (LHCGR) affects receptor biogenesis causing leydig cell hypoplasia

The human luteinizing hormone/chorionic gonadotropin receptor (LHCGR) plays a fundamental role in male and female reproduction. In males, loss-of-function mutations in LHCGR have been associated with distinct degrees of impairment in pre- and postnatal testosterone secretion resulting in a variable phenotypic spectrum, classified as Leydig cell hypoplasia (LCH) type 1 (complete LH resistance and disorder of sex differentiation) and type 2 (partial LH resistance with impaired masculinization and fertility).Here, we report the case of an adolescent who came to the pediatric endocrinologist at the age of 12 years old for micropenis and cryptorchidism. Testis biopsy showed profound Leydig cell hypoplasia and absent germinal line elements (Sertoli-only syndrome). The sequence analysis of the LHCGR gene showed the presence of a compound heterozygosity, being one variation, c.1847C>A p.S616Y, already described in association to Hypergonadotropic Hypogonadism (HH), and the other, c.29 C>T p.L10P, a new identified variant in the putative signal peptide of LHCGR. Functional and structural studies provide first evidence that LHCGR have a functional and cleavable signal peptide required for receptor biogenesis. Moreover, we demonstrate the pathogenic role of the novel p.L10P allelic variant, which has to be considered a loss-of-function mutation significantly contributing, in compound heterozygosity with p.S616Y, to the Leydig cell hypoplasia type 2 observed in our patient

Aplicación de la destilación molecular de camino corto a la separación de macromoléculas de aceites vegetales

Se han desarrollado ensayos experimentales a escala piloto para concentrar etil ésteres de ácidos grasos obtenidos por transesterificación de aceites vegetales comestibles. Los mismos se llevaron a cabo con el objetivo de concentrar los tipos poliinsaturados de C18, en particular el correspondiente al alfa-linolénico (ALA), dado su interés de comercialización a partir de dichos aceites, a diferencia de otros compuestos de interés como los ácidos eicosapentaenoico (EPA) y docosahexaenoico (DHA), presentes de manera natural en otros derivados de productos marinos. Tales ensayos constituyen una de las etapas principales de un desarrollo tecnológico que comprende el tratamiento integral del proceso de obtención de etil ésteres de ácidos grasos a partir aceites vegetales comestibles no tradicionales, en el contexto de un convenio específico establecido entre la Facultad Regional Villa María de la UTN y la empresa Porta Hnos S.A. Se evaluaron diferentes condiciones de operación, principalmente temperaturas y niveles de vacío, a efectos de optimizar la separación deseada utilizando un destilador molecular de camino corto facilitado por la empresa. La concentración del producto se llevó a cabo operando en múltiples etapas. La primera destilación parte del material transesterificado obtenido en una instancia previa, separándose los etil ésteres -EE- de un residuo constituido por otros suproductos de distintos tipos y características (no etil ésteres- NEE). Luego los EE fueron destilados sucesivamente hasta alcanzar un producto concentrado resultante de cortes intermedios entre livianos y pesados, los que se recuperaron luego como subproducto. Se empleó cromatografía en fase gaseosa para su cuantificación. Como resultados se menciona la determinación de las condiciones de operación que permiten llevar el proceso a escala productiva y la obtención de un producto acorde a requerimientos.Fil: Bragagnini Napolitado, Virginia M. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Vottero, Tomás J. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Magnani, Ezequiel. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Toselli, Luis A. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Peer Reviewe

Revisión de las variables que afectan el rendimiento de la reacción de transesterificación para la producción de etil ésteres de ácidos grasos

Los ácidos grasos presentes en los aceites vegetales se encuentran en forma de triglicéridos. Laestructura de esta molécula se ve modificada cuando se somete a una reacción detransesterificación (TE).Se han utilizado diferentes aceites vegetales para la reacción de transesterificación en la cual seevaluaron diferentes variables, principalmente tipo de catalizador, relación másicacatalizador/aceite y tiempo de reacción. Se pretende determinar el perfil de ácidos grasos quecomponen dichos aceites, siendo de mayor interés los poliinsaturados de cadenas de 18 átomosde carbono (C18): omega 9, 6 y 3. El perfil de ácidos grasos fue determinado mediante la técnicaGC/FID, y la observación cualitativa del avance de la reacción a través de cromatografía de capafina (TLC).La transesterificación es crucial para el desarrollo tecnológico de un proceso que consiste en laobtención de etil ésteres de ácidos grasos (EEAG) a partir de aceites vegetales comestibles noconvencionales, en el marco de un convenio establecido entre la Facultad Regional Villa María dela UTN y la empresa Porta Hermanos S.A. de la ciudad de Córdoba.En términos generales se indica que se ha estudiado la influencia de las distintas variables yconcluido que la concentración de catalizador tiene relación directa en el avance de la reacción.Fil: Vottero, Tomás J. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Stroppiano, María F. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Magnani, Ezequiel. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Toselli, Luis A. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Fil: Beltrán, Romina. Universidad Tecnológica Nacional. Facultad Regional Villa María. GISIQ; Argentina.Peer Reviewe