Discontinuous quarter-point boundary elements revisited: Computation of T-stress in two-dimensional cracked components

Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)This paper analyzes the use of discontinuous quarter-point quadratic elements in a dual or hypersingular boundary element context to compute the T-stress for cracked 2-D isotropic components. The performance of this approach has been demonstrated in the past for stress intensity factors (SIFs) computation and, herein, it is revisited to assess its adequacy for T-stress evaluation. To this end, novel direct extrapolation formulas that determine the T-stress from the computed nodal displacements at the collocation nodes of the discontinuous quarter-point element are proposed, and their accuracy and effectiveness is satisfactorily tested by several numerical examples involving 2-D cracked Carbon NanoTube (CNT) reinforced composites. SIFs extrapolated from the computed nodal crack opening displacements and T-stress evaluated from the computed stresses at internal points (close to the crack-tip) are also presented for completeness. The proposed techniques are a valid and easy-to-implement alternative to the interaction integral approaches when determining SIFs and T-stress.Ministerio de Ciencia, Innovación y Universidades RTI2018-094945-B-C21Fondo Europeo de Desarrollo RegionalConsejería de Economía y Conocimiento P18-RT-31

Complicaciones en la cirugía de las luxaciones acromioclaviculares: Estudio comparativo de dos técnicas quirúrgicas

Se realiza un estudio comparativa, retrospectivo, de 46 pacientes con luxación acromioclavicular grado III tratadas quirúrgicamente por la técnica de Phemister (30 caos) y de Bosworth (16 casos). El análisis preoperatorio de ambos grupos no demostró diferencias estadísticamente significativas exceptuando el seguimiento que fue mayor en el grupo de Phemister. En cuanto a resultados, todos los pacientes evolucionaron a la movilidad completa del hombro, con reincorporación a su actividad habitual. No existieron en este apartado diferencias significativas entre ambos grupos. La incidencia de complicaciones fue mayor en el grupo Phemister (75%) que en el Bosworth (13%), debidas fundamentalmente a problemas relacionados con el material de osteosíntesis empleado y con el abordaje quirúrgico. El tornillo utilizado en la técnica de Bosworth asegura buenos resultados funcionales, con menos agresividad quirúrgica y menor riesgo de complicaciones. En ambas técnicas hay que retirar el material en un segundo acto quirúrgico, por lo que debe tenerse en cuenta la posibilidad de emplear implantes de material biorreabsorbible para estudios posteriores.The study compared the clinical and radiographic outcome of two surgical techniques for acute grade III acromioclavicular dislocation: Phemister (30 patients) and Bosworth (16 patients). There are no significative differences between the two groups related to the preoperative assessment. Only the follow-up period was longer in the Phemister group. Concerning results, all patients recovered complete movility and returned to work. There was no significative differences in this evaluation. The Phemister group shows a higher incidence of complications (75%) than the Bosworth group (13%), mainly problems relative to the implant and the surgical approach. The screw employed in the Bosworth technique assure good functional results with lower risk of complications. In both procedures is necessary to remove the hardware in a second operation. The use of bioabsorbable implants should be considered in further studies

Towards a goal-oriented agent-based simulation framework for high-performance computing

Currently, agent-based simulation frameworks force the user to choose between simulations involving a large number of agents (at the expense of limited agent reasoning capability) or simulations including agents with increased reasoning capabilities (at the expense of a limited number of agents per simulation). This paper describes a first attempt at putting goal-oriented agents into large agentbased (micro-)simulations. We discuss a model for goal-oriented agents in HighPerformance Computing (HPC) and then briefly discuss its implementation in PyCOMPSs (a library that eases the parallelisation of tasks) to build such a platform that benefits from a large number of agents with the capacity to execute complex cognitive agents.Peer ReviewedPostprint (author's final draft

Artroplastia no cementada de cadera tipo Lord en el tratamiento de la coxartrosis: estudio de 70 casos

Se han revisado 70 artroplastias totales de cadera no cementada tipo LORD implantadas en el Hospital Clínico de San Carlos de Madrid, en pacientes afectos de coxartrosis. El seguimiento mínimo ha sido de 20 meses y máximo de 90. La valoración clínica se ha realizado según el sistema de Merle D 'AUBIGNE con un 82.2% de buenos resultados, destacando entre los malos resultados: cuatro aflojamientos del componente acetabular, un aflojamiento del componente femoral y una infección. También se lleva a cabo una valoración radiológica no cuantitativa, en la que se cotejan parámetros radiológicos postoperatorios y evolutivos con su repercusión clínica.The authors have reviewed 70 non cemented Lord prosthese s implanted at the Hospital Clínico de San Carlos of Madrid for osteoarthritis of the hip. The minimum follow up period wa s 20 months and the maximum of 90. The clinical evaluation has been performed using the Merle D'aubigne system showing 82.2% of good results. It is worth pointing out from the bad cases: four aseptic acetabular component loosening, one femoral stem loosening and one septic failure. They have also evaluated radiologically our case s by a non cuantitative method, comparing postoperative and long term follow up Xray films with their clinical outcome

Osteotomía valgizante de tibia: estudio de dos técnicas quirúrgicas

Se evalúan clínica y radiológicamente 51 rodillas artrósicas tratadas median - te osteotomía tibial valguizante según dos técnica s diferentes con fines comparativos. En 37 rodillas se empleó la osteotomía en cúpula con fijador externo y en las restante s se practicó la técnica en cuña de sustracción. El período de seguimiento medio fue de 42.2 meses. La suma de resultados buenos y excelente s ha sido 77.9%. La osteotomía en cúpula tiene , en esta serie, un mayor índice de pérdidas de corrección, correcciones insuficientes y complicaciones, obteniendo menor porcentaje de buenos resultados. Estos se deterioran en pacientes de mayor edad y gonartrosis evolucionada. Los autores consideran la osteotomía valguizante de tibia, un tratamiento válido par a pacientes de edad no avanzada y con gonartrosis grados I y II con genu varo.Two tecniques o f high tibia l osteotom y i n fifty-one ostheoarthiti c knee s evaluate d b y roentgenographi c an d clinica l examination . I n thirty-seve n patien s a dom e shape d osteotom y wit h externa l fixatio n wa s done . I n th e rest o f case s w e performe d a wedg e osteotomy . T h e numbe r o f goo d an d excelen t results wa s 77.9%. Th e dom e osteotom y ha s i n o u r experience , a hig h rat e o f recurren t varu s angulation , malalignemen t an d othe r complications. T h e olde r grou p o f patients ha d wors e results. Th e author s recomen d th e wedg e hig h tibia l osteotom y fo r osteoarthritis an d varu s kne e i n younge r patients

Post-fire recovery of ecosystem carbon pools in a tropical mixed pine-hardwood forest

Aim of the study: To analyze the recovery pattern of carbon pools in terms of size and the relative contribution of each pool to total ecosystem C along a fire chronosequence of tropical mixed pine-hardwood forest.Area of the study: Las Joyas Research Station (LJRS), core zone of Sierra de Manantlán Biosphere Reserve (SMBR) in the state of Jalisco, central western Mexico.Materials and methods: Carbon stored in aboveground plant biomass, standing dead trees, downed woody debris, forest floor, fine roots and mineral soil, was compared with a nested analysis of variance (ANOVA) in post-fire stands of eight-year-old, 28- and 60-year-old stands of mixed Pinus douglasiana-hardwood forest.Main results: The total ecosystem carbon in eight-year-old stands was 50% lower than that of 60-year-old stands. Carbon content in the biomass and mineral soil increased with stand age. The carbon in the biomass recovered to the undisturbed forest in the 28 years of succession. The main C storage in the eight-year-old stands were the mineral soil (64%) and downed woody debris (18%), while in the 28- and 60-year-old stands, live tree biomass and mineral soil were the two largest components of the total C pool (43% and 46%, respectively).Research highlights: We found a significant effect of high-severity fire events on ecosystem C storage and a shift in carbon distribution. The relatively fast recovery of C in ecosystem biomass suggests that mixed Pinus douglasiana hardwood forest possess functional traits that confer resilience to severe fire events.Key words: chronosequence; carbon dynamics; mineral soil; Pinus douglasiana; fire effects.Abbreviations used: LJRS, Las Joyas Research Station; DBH, diameter at breast height; DL, duff layer; LL, litter layer; DWD, downed woody debris; ANOVA, analysis of variance; CO2, carbon dioxide; SMBR, Sierra de Manantlán Biosphere Reserve; C, carbon. AGV, above ground vegetation

Suelos de humedal del lago de Pátzcuaro, Michoacán, México

En México, en particular en el estado de Michoacán, el estudio sobre la génesis, morfología y función de los suelos hidromórficos no ha sido explorado de forma suficiente, pese a contar con grandes extensiones de humedales continentales, como la zona vadosa del lago de Pátzcuaro. Se estudiaron dos humedales representativos de la costa del lago de Pátzcuaro, Michoacán: uno de ellos saturado permanentemente, con desarrollo de gleysoles, y un humedal con inundación periódica, fluvisoles, desarrollados en una gran planicie aluvial. Los resultados indican la presencia de un gleysol háplico (colúvico, éutrico) (WRB, 2006), de coloración pardo oscuro, con cantidades moderadas de carbono orgánico (0.87% promedio), arcilloso > 30%, de estructura predominante de poliedros subangulares y prismas con segregación de sesquióxidos ferromanganosos, sobresaliendo los hiporrevestimientos de óxidos de fierro, y presencia de restos de ostrácodos en la mayor parte del perfil. Destaca una discontinuidad litológica. Por su parte, en el humedal aluvial se presenta un fluvisol háplico (hiperhúmico, éutrico) (WRB, 2006), un suelo con matriz de color pardo grisáceo, con altos contenidos de materia orgánica en todo el perfil (> 7 %) y restos de ostrácodos. Son suelos con alta saturación de bases (> 50 %). Tres zonas de humedad son bien definidas al interior de los suelos: una zona baja de endosaturación permanente, una zona intermedia producto de la capilaridad, y una zona de secado-humedecimiento alternado en los epipedone

Reasoning about river basins: WaWO+ revisited

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper characterizes part of an interdisciplinary research effort on Artificial Intelligence (AI) techniques and tools applied to Environmental Decision-Support Systems (EDSS). WaWO+ the ontology we present here, provides a set of concepts that are queried, advertised and used to support reasoning about and the management of urban water resources in complex scenarios as a River Basin. The goal of this research is to increase efficiency in Data and Knowledge interoperability and data integration among heterogeneous environmental data sources (e.g., software agents) using an explicit, machine understandable ontology to facilitate urban water resources management within a River Basin.Peer ReviewedPostprint (author's final draft

Health recommender system design in the context of CAREGIVERSPRO-MMD project

CAREGIVERSPRO-MMD an EU H2020 funded project aims to build a digital platform focusing on people living with dementia and their caregivers, offering a selection of advanced, individually tailored services enabling them to live well in the community for as long as possible. This paper provides an outline of a health recommender system designed in the context of the project to provide tailored interventions to caregivers and people living with dementia.Peer ReviewedPostprint (published version