92 research outputs found
Desarrollo de nuevos agentes espumantes endotérmicos para la fabricación de materiales celulares poliméricos
Este trabajo de fin de grado trata sobre la obtención de agentes espumantes químicos endotérmicos a partir de sustancias puras. El primer objetivo es la búsqueda de la composición de estos agentes. Para ello se determina la composición de un agente espumante endotérmico de referencia a partir de la bibliografía y su caracterización y comparación con sustancias puras. El segundo objetivo será el análisis de componentes puros. A continuación se fabrican mezclas de estos componentes. Estas se caracterizan y se eligen las mejores para la creación de materiales celulares. El tercer objetivo será el uso de estas mezclas en un material polimérico y su espumado. Se fabricarán precursores de polietileno de baja densidad con_los agentes espumantes. Una vez obtenidos los materiales celulares, y se compara su celda abierta,-densidad y grado de expansión con los materiales celulares espumados Y el último objetivo es un análisis comparativo entre las distintas mezclas y el agente espumante de referencia.Grado en Físic
Effect of mold temperature on the impact behavior and morphology of injection molded foams based on polypropylene polyethylene–octene copolymer blends
Producción CientíficaIn this work, an isotactic polypropylene (PP) and a polyethylene–octene copolymer (POE) have been blended and injection-molded, obtaining solids and foamed samples with a relative density of 0.76. Different mold temperature and injection temperature were used. The Izod impact strength was measured. For solids, higher mold temperature increased the impact resistance, whereas in foams, the opposite trend was observed. In order to understand the reasons of this behavior, the morphology of the elastomeric phase, the crystalline morphology and the cellular structure have been studied. The presence of the elastomer near the skin in the case of high mold temperature can explain the improvement produced with a high mold temperature in solids. For foams, aspects as the elastomer coarsening in the core of the sample or the presence of a thicker solid skin are the critical parameters that justify the improved behavior of the materials produced with a lower mold temperature.Ministerio de Economía, Industria y Competitividad (grant DI-15-07952
Foams with enhanced ductility and impact behavior based on polypropylene composites
Producción CientíficaIn this work, formulations based on composites of a linear polypropylene (L-PP), a long-chain branched polypropylene (LCB-PP), a polypropylene–graft–maleic anhydride (PP-MA), a styrene-ethylene-butylene-styrene copolymer (SEBS), glass fibers (GF), and halloysite nanotubes (HNT-QM) have been foamed by using the improved compression molding route (ICM), obtaining relative densities of about 0.62. The combination of the inclusion of elastomer and rigid phases with the use of the LCB-PP led to foams with a better cellular structure, an improved ductility, and considerable values of the elastic modulus. Consequently, the produced foams presented simultaneously an excellent impact performance and a high stiffness with respect to their corresponding solid counterparts.Unión Europea (Evolution project under grant 314744)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project RTI2018-098749-B-I00)Junta de Castilla y Leon (project VA275P18
Crosslinked ethylene butyl acrylate copolymer foams with different cellular structure interconnectivity and tortuosity: Microstructure and physical properties
Producción CientíficaIn this work, the cellular structure, physical properties, and the structure–property relationship of several novel crosslinked ethylene butyl acrylate (EBA) foams with different cellular structure interconnectivity (low tortuosity and high tortuosity) have been analyzed and compared to that of closed cell EBA foams and to that of an open-cell polyurethane foam. The results have shown that these materials present interesting properties highly dependent on the tortuosity of the cellular structure. In particular, it has been proved that reducing the tortuosity allows enhancing the acoustic absorption, the oil uptake, and the cushioning behavior. On the other hand, increasing tortuosity allows improving the impact behavior. In addition, the new open-cell materials present an enhanced damping factor for low-frequency vibrations.Ministerio de Economía, Industria y Competitividad (grant DI-15-07952)Ministerio de Asuntos Económicos y Transformación Digital-FEDER, UE (project MAT2015-69234-R)Junta de Castilla y León (project VA275P18
Estudio de los resultados del Proceso de Acreditación en Universidades Chilenas a través de la Grounded Theory
La acreditación, definida por La Red Iberoamericana para la Acreditación de la Calidad de la Educación Superior (RIACES), corresponde al “Proceso para garantizar la calidad de una institución o de un programa educativo”, el cual según la misma definición, “es llevado a cabo por una agencia externa a las instituciones de educación superior”. La acreditación -o certificación- reconoce la calidad de los programas, o de la institución acreditada. Este proceso en Chile estuvo a cargo, hasta julio del 2007, de la Comisión Nacional de Acreditación de Pregrado (CNAP). El presente trabajo tiene como objetivo, mediante una investigación de tipo cualitativo utilizando la Grounded Theory, revisar los resultados de la acreditación de este proceso, sobre programas educativos, reflejados en los acuerdos de acreditación existentes y de dominio público, para determinar cuáles son los factores que inciden en un buen resultado de acreditación. La evaluación que se realiza para el proceso de acreditación, considera tres dimensiones de análisis: Perfil de Egreso y Resultado, Condiciones de Operación y Capacidad de Autorregulación, que a su vez, están compuestas por nueve criterios de evaluación. En los acuerdos de acreditación, vienen reflejadas las fortalezas y debilidades de las carreras (y de la unidad responsable). La importancia de este trabajo, reside en la identificación de los factores que inciden en la calidad de la formación proporcionada a universitarios, con el objetivo de que ésta pueda ser incrementada y, adicionalmente como consecuencia, contribuir a obtener mejores resultados en el proceso de acreditación
Assessing the risk of an emerging zoonosis of worldwide concern : anisakiasis
The authors sincerely thank the Biobanking platform at the PARASITE project (EU FP7 PARASITE project (GA no. 312068)) for providing host-parasite data. We thank Rosa Fernández and Cristina Martínez from CETMAR for their help during creation and divulgation of the questionnaires. We also thank Arturo del Rey Moreno (“Antequera” hospital) for his helpful comments. We are also grateful to “Subdirección General de Economía Pesquera” of “Ministerio de Agricultura, Alimentación y Medio Ambiente” (MAGRAMA) of the Spanish government for providing anchovy trade statistics for 2013. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068).Peer reviewedPublisher PD
Sensitization profiles to purified plant food allergens among pediatric patients with allergy to banana.
Banana fruit allergy is well known, but neither immunoglobulin E recognition patterns to purified plant food allergens nor true prevalences of putative banana allergens have been established. This study aimed to characterize β-1,3-glucanase and thaumatin-like protein (TLP) as banana allergens, testing them, together with other plant food allergens, in 51 children with allergic reactions after banana ingestion and both positive specific IgE and skin prick test (SPT) to banana. Banana β-1,3-glucanase and TLP were isolated and characterized. Both banana allergens, together with kiwifruit TLP Act d 2, avocado class I chitinase Pers a 1, palm pollen profilin Pho d 2 and peach fruit lipid transfer protein (LTP) Pru p 3, were tested by in vitro and in vivo assays. Banana β-1,3-glucanase (Mus a 5) was glycosylated, whereas banana TLP (Mus a 4) was not, in contrast with its homologous kiwi allergen Act d 2. Specific IgE to both banana allergens, as well as to peach Pru p 3, was found in over 70% of sera from banana-allergic children, and Mus a 4 and Pru p 3 provoked positive SPT responses in 6 of the 12 tested patients, whereas Mus a 5 in only one of them. Both peptidic epitopes and cross-reactive carbohydrate determinants were involved in the IgE-binding to Mus a 5, whereas cross-reactivity between Mus a 4 and Act d 2 was only based on common IgE protein epitopes. Profilin Pho d 2 elicited a relevant proportion of positive responses on in vitro (41%) and in vivo (58%) tests. Therefore, Mus a 4 and LTP behave as major banana allergens in the study population, and profilin seems to be also a relevant allergen. Mus a 5 is an equivocal allergenic protein, showing high IgE-binding to its attached complex glycan, and low in vivo potency
Follow-up with Telemedicine in Early Discharge for COPD Exacerbations: Randomized Clinical Trial (TELEMEDCOPD-Trial)
The results reported by different studies on telemonitoring in patients with chronic obstructive pulmonary disease (COPD) have been contradictory, without showing clear benefits to date. The objective of this study was to ascertain whether an early discharge and home hospitalization telehealth program for patients with COPD exacerbation is as effective as and more efficient than a traditional early discharge and home hospitalization program. A prospective experimental non-inferiority study, randomized into two groups (telemedicine/control) was conducted. The telemedicine group underwent monitoring and was required to transmit data on vital constants and ECGs twice per day, with a subsequent telephone call and 2 home visits by healthcare staff (intermediate and at discharge). The control group received daily visits. The main variable was time until first exacerbation. The secondary variables were: number of exacerbations; use of healthcare resources; satisfaction; quality of life; anxiety-depression; and therapeutic adherence, measured at one and 6 months of hospital discharge. A total of 116 patients were randomized (58 to each group) without significant differences in baseline characteristics or time until first exacerbation, i.e. median 48 days (pp. 25-75:23-120) in the control group, and 47 days (pp. 25-75:19-102) in the intervention group; p = 0.52). A significant decrease in the number of visits was observed in the intervention versus the control group, 3.8 ± 1 vs 5.1 ± 2(p = 0.001), without significant differences in the number of exacerbations. In conclusion follow-up via a telemedicine program in early discharge after hospitalization is as effective as conventional home follow up, being the cost of either strategy not significantly different.This study was awarded a Health Research Fund (Fondo de Investigaciones Sanitarias/FIS) grant, dossier No. PI12/01161 of the Carlos III Institute of Health and the Ministry of Sciences, Innovation and Universities.S
Performance analysis of wind fence models when used for truck protection under crosswind through numerical modeling
This paper is focused on truck aerodynamic analysis under crosswind conditions by means of numerical modeling. The truck was located on the crest of an embankment during the study. In order to analyze the performance of three wind fence models, the truck's aerodynamic coefficients were obtained and compared in two different situations either with or without the wind fences installed. In addition, the effect of both height and porosity of wind fence models on the aerodynamic coefficients acting on truck with respect to separation distance between the truck and the wind fence, was analyzed. A finite volume (or computational fluid dynamic) code was used to carry out the numerical modeling. The Reynolds-averaged Navier?Stokes (RANS) equations along with the k?? SST turbulence model were used to predict the behavior of turbulent flow. With respect to the results, the influence of the distance on the rollover coefficient is soft for all height values studied except for the lowest value (1 m of fence height), where the maximum value of rollover coefficient was obtained for the truck position closer to the fence. Regarding fence porosity, its effect on rollover coefficient is stronger for truck positions on road closer to the wind fence model.This work was supported by the OASIS Research Project that was co-financed by CDTI (Spanish Science and Innovation Ministry) and developed with the Spanish companies: Iridium, OHL Concesiones, Abertis, Sice, Indra, Dragados, OHL, Geocisa, GMV, Asfaltos Augusta, Hidrofersa, Eipsa, PyG, CPS, AEC and Torre de Comares Arquitectos S.L. and 16 research centres. The authors would also like to thank the GICONSIME research group of the University of Oviedo (Spain) for their collaboration in this research
HAZLO: Plataforma de telesalud basada en tecnologías mhealth para el despliegue de programas personalizados de rehabilitación cardiaca fase II
CASEIB 2015. XXXIII Congreso Anual de la Sociedad Española de Ingeniería Biomédica. Madrid 4, 5 y 6 de noviembre 2015.Actualmente, los Programas de Rehabilitación Cardiaca, tanto en provisión presencial como domiciliaria, afrontan la necesidad de incrementar sus tasas de adopción y adherencia, y en estos retos, los servicios de telesalud basados en mhealth comienzan a jugar un papel relevante, aunque la evidencia es fragmentada y de baja calidad. Se ha implementado un servicio de telesalud que despliega un programa basado en actividades terapéuticas de rehabilitación física (marcha) y psicológica (relajación), contenidos educativos para la autogestión, y herramientas para la interacción virtual (mensajería, videollamada y foros). Se presenta en este trabajo la descripción del servicio y los resultados del pilotaje (41 pacientes, 5 meses), para evaluar la viabilidad en términos de operatividad-funcionalidad en cada uno de sus componentes y adherencia a los protocolos por parte de los pacientes. Se ha iniciado un ensayo aleatorizado controlado (128+128 pacientes) para estudiar la no inferioridad en resultados clínicos del modelo de provisión basado en telesalud frente al tradicional; adicionalmente, se estudiarán la mejora en calidad de vida, satisfacción y usabilidad.Este trabajo está siendo financiado por la AES 2012, PI12/00389 y PI12/00585 (coordinados), y PI12/00508, y la colaboración de REDISSEC RD12/0001/0001.N
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