Campo tensional en el entorno de una fisura. Determinación de KI y KII usando técnicas fotoelásticas

Trabajo reproducido y difundido en el repositorio idUS con permiso de la Asociación Española de Ingeniería Mecánica (AEIM)Tras introducir la forma general del campo de tensiones en un borde de grieta se hace una exposición detallada de los métodos para medir K I y K II, resaltando sus ventajas e inconvenientes. Por su generalldad, se ha implementado un método que desarrolla en serie las funciones de tensión. La introducción de las medidas fotoelásticas (que pueden ser de campo lejano) conduce a un sistema sobredetermlnado no lineal de ecuaclones, que es resuelto por un métooo de Neewton-Raphson y mínimos cuadrados. Sobre una aplicación experimental se comentan las caracterlstlcas de este métodoFirst of all, the general form of the crack-tip stress field is introduced. Then, a detailed review of K I-K II methods is pressented, showing thelr features. A stress-functions series expansion method has been implemented, due to its generality. Experimental far-fleld isochromatic polnts are used to fit the series expanslon coefflclents and the overdeterminlstlc non-linear equation system is solved with a Newton-Rapshon least-squares method. Finally the features of thls method are dlscussed uslng an experimental applicatio

A linguaxe como medio de violencia simbólica no deporte

[RESUMO] En todas as sociedades machistas a linguaxe ten un papel fundamental na discriminación das mulleres, configurándose como un instrumento de dominación e lexitimador da violencia simbólica. O obxectivo deste estudo foi analizar se as estudantes de Ciencias do Deporte e a Educación Física da Universidade da Coruña reciben frases ao longo da súa carreira deportiva que reflicten a dominación e reprodución dun modelo social discriminatorio. A metodoloxía empregada inscríbese baixo o paradigma cualitativo e feminista, facendo uso da análise de contido como técnica de investigación. Para a recompilación de datos empregouse unha ficha de rexistro anecdótico que se aplicou a corenta alumnas e un grupo de discusión con cinco estudantes. Os resultados permítennos concluír que a linguaxe é un medio máis de violencia simbólica no deporte, que perpetúa un sistema de dominación masculina a través da transmisión dunha visión de inferioridade das mulleres, que menospreza a súa práctica e establece como ideal o deporte masculino. Non se acepta que unha muller poida ser superior a un home en situacións deportivas mixtas e danse casos nos que, a través da linguaxe, se chega a incitar á violencia física e sexual.

Banco fotoelástico para análisis de estructuras fisuradas sometidas a cargas de impacto

Se presenta un banco de Fotoelasticidad Dinámica con una cámara Cranz-Schardin de 9 disparos que permite obtener información en nueve instantes de tiempo en órdenes de microsegundos. Este orden permite analizar periodos transitorios consecutivos a la producción de un impacto sobre una estructura. En el presente trabajo se incluye el análisis de un pórtico fisurado encontrándose que el nivel de resolución alcanzado en la configuración de isocromáticas es suficiente como para poder aplicar distintas alternativas (de campo singular y de campo lejano) en orden a determinar los factores de intensificación de tensión. KI y KII.A Dynamic Photoelastic arrangement using a nine spark Cranz-Schardin camera is presentad. A level of resolution of microseconds in the pictures is obtained. This level allows to onalyze tronsient periods inmediately after an impact hos been produced on the structure. The analysis of a cracked portal frame is included finding that the level of resolution in the isochromotic pattern is good enough to apply several methods, based on the singulor field or on a far field solution, in order to estimate the values of the stress intensity factors, KI and KI

Tuberculostearic Acid-Containing Phosphatidylinositols as Markers of Bacterial Burden in Tuberculosis

One-fourth of the global human population is estimated to be infected with strains of the Mycobacterium tuberculosis complex (MTBC), the causative agent of tuberculosis (TB). Using lipidomic approaches, we show that tuberculostearic acid (TSA)-containing phosphatidylinositols (PIs) are molecular markers for infection with clinically relevant MTBC strains and signify bacterial burden. For the most abundant lipid marker, detection limits of ∼10$^{2}$ colony forming units (CFUs) and ∼10$^{3}$ CFUs for bacterial and cell culture systems were determined, respectively. We developed a targeted lipid assay, which can be performed within a day including sample preparation─roughly 30-fold faster than in conventional methods based on bacterial culture. This indirect and culture-free detection approach allowed us to determine pathogen loads in infected murine macrophages, human neutrophils, and murine lung tissue. These marker lipids inferred from mycobacterial PIs were found in higher levels in peripheral blood mononuclear cells of TB patients compared to healthy individuals. Moreover, in a small cohort of drug-susceptible TB patients, elevated levels of these molecular markers were detected at the start of therapy and declined upon successful anti-TB treatment. Thus, the concentration of TSA-containing PIs can be used as a correlate for the mycobacterial burden in experimental models and in vitro systems and may prospectively also provide a clinically relevant tool to monitor TB severity

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised