Inspection scheduling based onreliability updating of gas turbinewelded structures

This article presents a novel methodology for the inspection scheduling of gas turbine welded structures, based on reliability calculations and overhaul findings. The model was based on a probabilistic crack propagation analysis for welds in a plate and considered the uncertainty in material properties, defect inspection capabilities, weld geometry, and loads. It developed a specific stress intensity factor and an improved first-order reliability method. The proposed routine alleviated the computational cost of stochastic crack propagation analysis, with accuracy. It is useful to achieve an effective design for manufacturing, to develop structural health monitoring applications, and to adapt inspection schedules to airplane fleet experience.We are grateful to the Mechanical Technology Department of ITPAero (R) for supporting and helping us with this study. The invaluable guidance and feedback from Jose Ramon Andujar is recognized with great appreciation

Sensibilidad y especificidad en la endosonografía en diagnóstico de cáncer de cabeza de páncreas. Clínica general del norte, periodo 2013-2014

Objective: To determine the sensitivity and specificity of endosonography in diagnosis of pancreatic head cancer in patients with clinical suspicion of pancreatic cancer served in the Clinica General del Norte, January 2013-December 2014. Materials and methods: Evaluation study using a screening test, Endosonographic a total of 457 procedures were performed; the sample is for convenience in patients endosonography was indicated by clinical suspicion of pancreatic cancer and met the inclusion criteria for a total of 46 patients. Results: Females showed the highest prevalence in the studied sample with 54.3 %, mean age 63.5 ± 3.0 years, 40 cases suggestive of malignancy in endosonography, was correlated with histopathological at 37, and 6 cases of benign pathology findings suggestive of correlated in 1 case. Conclusions: Endosonographic the imaging findings in the diagnosis of pancreatic head cancer, shows a sensitivity of 97.3 %, with a specificity of 62.5 %, based on the pathological-histological report pancreatic tissue (gold standard).Objetivo: Determinar la sensibilidad y especificidad de la endosonografía en el diagnóstico de cáncer de cabeza de páncreas en pacientes con sospecha clínica de cáncer de páncreas atendidos en la Clínica General del Norte, enero de 2013-diciembre de 2014. Materiales y Métodos: Estudio evaluativo mediante el uso de una prueba tamiz, se realizaron un total de 457 procedimientos endosonográficos; la muestra es por conveniencia en aquellos pacientes que se indicó la endosonografía por sospecha clínica de cáncer de páncreas y cumplieron los criterios de inclusión, para un total de 46 pacientes. Resultados: El sexo femenino mostró la mayor prevalencia en la muestra estudiada con un 54,3 %, la edad media 63,5 ± 3,0 años; de los 40 casos de hallazgos sugestivos de patología maligna en endosonografía, se correlacionó con la histopatología en 37, y de los 6 casos de hallazgos sugestivos de patología benigna se correlacionó en 1 caso. Conclusiones: Los hallazgos endosonográficos imagenológicos, en el diagnóstico de cáncer de cabeza de páncreas, muestra una sensibilidad del 97,3 %, con una especificidad del 62,5 %, basados en el reporte anatomopatológico-histológico del tejido pancreático (gold estándar)

Detection of risk factors that influence weight loss in patients undergoing radiotherapy

AbstractAimTo identify risk factors that influence weight loss in patients receiving radiotherapy.BackgroundIt is a well-known fact that cancer patients can be affected by malnutrition at the onset of the disease and during treatment due to the toxicity. Pretreatment weight loss alone does not predict those who will need nutritional supplementation. Instead, a variety of nutritional and tumor related factors needs to be taken into account.Material and methodsA retrospective study was conducted on 129 patients with different tumor locations. Weight loss was evaluated during radiotherapy and one month after treatment. The impact of age, ECOG, chemotherapy, pretreatment weight loss, tumor location, previous surgery and TNM were analyzed. We aimed to identify a high-risk group of patients before starting treatment.ResultsThe average net weight loss during radiotherapy and one month after treatment for this group of patients was 0.68kg and 1.6kg, respectively. Median weight loss during radiotherapy was 2.6 kg for head and neck (HN) patients and 0.27 kg for other tumor sites (p=0.028). Median weight loss one month after radiotherapy was 3.7kg for HN patients and 1.1kg for the rest of the patients (p=0.034). The median weight loss one month after treatment was 3.2 kg for patients receiving chemotherapy and 0.5kg for those patients who did not receive chemotherapy (p<0.001). A regression analysis determined that HN tumor location and the use of chemotherapy were independent risk factors.ConclusionsNutritional status must be monitored and managed before, during and after treatment. A variety of nutritional and tumor-related factors must be considered. According to our results, head and neck tumors and the use of chemotherapy are the only two factors considered statistically significant. Because patients continue to lose weight after treatment, we recommend close surveillance after radiotherapy

The Maunakea Spectroscopic Explorer Book 2018

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

Métodos para la resolución del problema no lineal de equilibrio estático en sistemas multicuerpo

En este trabajo se aborda la resolución del problema no lineal de posición de equilibrio estático y de otros problemas de posición en sistemas mecánicos multicuerpo complejos, que incluyen elementos rígidos y elásticos. En el estudio se utiliza una función de error sencilla, que se basa en la función potencial e incluye en el análisis a los elementos rígidos por medio de restricciones 110 lineales. Se presenta la aplicación de los Multiplicadores de Lagrange, Funciones de Penalización, Rigideces Ponderadas y de diferentes versiones del método de los Multiplicadores Aumentados o método Primal-Dual.This paper presents different approaches for the solution of non-linelai equilibrium problems in multibody systems. These systems cal1 include rigid and elastic el ments. The ideas here presented are also able to deal with other position pioblems, for insta t ce those which appear in the kinematic analysis of liiikages. The error function used is very siqple and is based in the potential of the system. The rigid elements are considered through non-linear constraints. Different appioaches are described: Lagrange Multipliers, Penalty Functions, Primal-Dual methods and Weighted Stiffnesses.Peer Reviewe

Sensibilidad y especificidad de la endosonografía en diagnóstico de cáncer de cabeza de páncreas: Clínica General del Norte, periodo 2013-2014

Determinar la sensibilidad y especificidad de la endosonografía en el diagnóstico de cáncer de cabeza de páncreas en pacientes con sospecha clínica de cáncer de páncreas atendidos en la Clínica General del Norte, enero de 2013-diciembre de 2014. Materiales y Métodos: Estudio evaluativo mediante el uso de una prueba tamiz, se realizaron un total de 457 procedimientos endosonográficos; la muestra es por conveniencia en aquellos pacientes que se indicó la endosonografía por sospecha clínica de cáncer de páncreas y cumplieron los criterios de inclusión, para un total de 46 pacientes. Resultados: El sexo femenino mostró la mayor prevalencia en la muestra estudiada con un 54,3 %, la edad media 63,5 ± 3,0 años; de los 40 casos de hallazgos sugestivos de patología maligna en endosonografía, se correlacionó con la histopatología en 37, y de los 6 casos de hallazgos sugestivos de patología benigna se correlacionó en 1 caso. Conclusiones: Los hallazgos endosonográficos imagenológicos, en el diagnóstico de cáncer de cabeza de páncreas, muestra una sensibilidad del 97,3 %, con una especificidad del 62,5 %, basados en el reporte anatomopatológico-histológico del tejido pancreático (gold estándar)