Aplicación Práctica de Métodos para Evaluar In-Situ el Rendimiento Instantáneo de Máquinas Frigoríficas de Compresión Mecánica

Libro de actas completo disponible en :http://repositorio.bib.upct.es:8080/dspace/handle/10317/4709Los equipos de aire acondicionado, bombas de calor y refrigeración suponen un elevado consumo de energía eléctrica en los países industrializados. Es frecuente que, en la práctica, estos equipos no estén operando con la eficiencia que debieran. De ahí la importancia de realizar inspecciones periódicas, que incluyan mediciones de los diferentes parámetros de operación de los equipos, destacando por su importancia la medición de su rendimiento (EER/COP). La medición precisa in-situ del EER/COP sobre una instalación frigorífica de compresión mecánica, fuera de un banco de ensayo de laboratorio, ha sido desde siempre una cuestión muy complicada, con muchas dificultades prácticas. Un punto crítico es la medición del caudal de fluido refrigerante. Si no se dispone de un caudalímetro instalado, que es la situación más habitual, hay que recurrir a mediciones indirectas. Hay varios métodos indirectos para estimar el caudal de refrigerante, que se pueden clasificar en los que se basan en: a) el rendimiento volumétrico del compresor, b) el rendimiento global del compresor, c) un balance de energía sobre el condensador y d) un balance de energía sobre el compresor. En este trabajo se ponen en práctica y analizan estos cuatro métodos sobre instalaciones frigoríficas existentes en el laboratorio docente del Departamento de Máquinas y Motores Térmicos de la Universidad de Málaga [1]. Para ello se utiliza un sistema de medición de bajo coste, basado en sensores ONSET [2]. El procesado y análisis de los datos se hace mediante el software Engineering Equation Solver [3]. Se discuten los resultados y dificultades encontradas en la aplicación de los diferentes métodos y se ofrecen recomendaciones a tener en cuenta para abordar instalaciones más complejas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Integración de Puentes Térmicos en Programas de Simulación Dinámica de Edificios mediante el Método del Muro Equivalente

Libro de actas completo disponible en :http://repositorio.bib.upct.es:8080/dspace/handle/10317/4709Los puentes térmicos son zonas de la envolvente de un edificio en las que se produce una transmisión preferencial de calor cuya causa es una heterogeneidad geométrica o material. Los programas más utilizados de simulación energética de edificios, como DOE-2 [1] o EnergyPlus [2], se basan en una hipótesis unidimensional para modelar la transmisión de calor en los cerramientos. No obstante, evaluar la transferencia de calor en los puentes térmicos implica resolver un problema de conducción bi- o tridimensional en régimen transitorio. Es posible utilizar herramientas especializadas como Voltra [3] o HEAT2 [4], pero no son generalmente aplicables a simulaciones estacionales, debido a su alto coste computacional. Se hace necesario un paso intermedio que conecte las simulaciones globales de edificios con los modelos detallados de puentes térmicos. Una de las aproximaciones más prácticas es la del “muro equivalente”, que consiste en identificar los parámetros de un muro multicapa ficticio, de forma que su respuesta dinámica sea muy próxima a la del elemento real, que tiene efectos 2D o 3D. Esta identificación de parámetros se puede llevar a cabo mediante diversos métodos. En este trabajo se aplica el método de identificación propuesto por Kosny [5] para obtener muros equivalentes que representen los tipos más usuales de puentes térmicos presentes en la construcción residencial española.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A Proposal for a Modified Moller-Plesset Perturbation Theory

A modified version of the Moller-Plesset approach for obtaining the correlation energy associated to a Hartree-Fock ground state is proposed. The method is tested in a model of interacting fermions that allows for an exact solution. Using up to third order terms improved results are obtained, even more accurate in the limit of loosely bound particles. This result suggests the possible convenience of the scheme for the study of chemical bound problems.Comment: 10 pages, 1 figur

Aircraft icing: in-cloud measurements and sensitivity to physical parameterizations

The prediction of supercooled cloud drops in the atmosphere is a basic tool for aviation safety, owing to their contact with and instant freezing on sensitive locations of the aircraft. One of the main disadvantages for predicting atmospheric icing conditions is the acquisition of observational data. In this study, we used in‐cloud microphysics measurements taken during 10 flights of a C‐212 research aircraft under winter conditions, during which we encountered 37 regions containing supercooled liquid water. To investigate the capability of the Weather Research and Forecasting model to detect regions containing supercooled cloud drops, we propose a multiphysics ensemble approach. We used four microphysics and two planetary boundary layer schemes. The Morrison parameterization yielded superior results, whereas the planetary boundary layer schemes were essential in evaluating the presence of liquid water content. The Goddard microphysics scheme best detected the presence of ice water content but tended to underestimate liquid water content

Influencia del factor de crecimieneto fibroblástico y la hidroxiapatita en la regeneración ósea tras resección crítica del cúbito del conejo

Peer Reviewe

Late myocardial reperfusion in ST-elevation myocardial infarction: Protocol for a systematic review and meta-analysis

Introduction ST-segment elevation myocardial infarction (STEMI) is the most severe clinical form of acute myocardial infarction, for which the current treatment consists of effective and timely myocardial reperfusion (within 12 hours of symptom onset). However, between 10% and 15% of patients with STEMI arrive at hospital facilities 12 hours after the onset of symptoms (late presentation). Therefore, the objective of the present study will be to determine if late revascularisation (12-72 hours after the onset of symptoms) affects the indicators of cardiovascular mortality, reinfarction, recurrent infarction, hospitalisation for heart failure and post infarction angina compared with no late revascularisation in patients with STEMI. Methods and analysis A systematic literature search of PubMed, The Cochrane Library, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, Scopus and Global Health will be conducted. Publications in English, Portuguese or Spanish that report the clinical results of primary percutaneous revascularisation (primary PCI) in adult patients with STEMI 12-72 hours after the onset of symptoms will be included. Studies with participants with a diagnosis other than STEMI or patients with STEMI of >12 hours complicated by heart failure, cardiogenic shock or ventricular arrhythmias, and studies of combined interventions (pharmacoinvasive strategy) were excluded. Two independent authors will identify the relevant publications, and discrepancies will be adjudicated by a third author. Data extraction will be performed by two independent authors and verified by a third author. Risk of bias of studies will be assessed using the Cochrane risk of bias' tool (RoB 2) or Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool. If appropriate, a meta-analysis will be performed in order to examine the effect of late revascularisation in clinical outcomes of interest. Ethics and discussion This study will use published data only, thus, ethical approval will not be required. The results will be disseminated through peer-reviewed publication and conference presentations. PROSPERO registration number CRD42021283429.Revisión por pare

Influenza vaccine and risk of acute myocardial infarction in a population-based case-control study

Objective To assess the relationship between influenza vaccination and risk of a first acute myocardial infarction (AMI) in the general population by different epidemic periods. Methods This is a population-based case?control study carried out in BIFAP (Base de datos para la investigación farmacoepidemiológica en atención primaria), over 2001?2015, in patients aged 40?99 years. Per each incident AMI case, five controls were randomly selected, individually matched for exact age, sex and index date (AMI diagnosis). A patient was considered vaccinated when he/she had a recorded influenza vaccination at least 14 days before the index date within the same season. The association between influenza vaccination and AMI risk was assessed through a conditional logistic regression, computing adjusted ORs (AOR) and their respective 95% CIs. The analysis was performed overall and by each of the three time epidemic periods per study year (pre-epidemic, epidemic and postepidemic). Results We identified 24 155 AMI cases and 120 775 matched controls. Of them, 31.4% and 31.2%, respectively, were vaccinated, yielding an AOR of 0.85 (95% CI 0.82 to 0.88). No effect modification by sex, age and background cardiovascular risk was observed. The reduced risk of AMI was observed shortly after vaccination and persisted over time. Similar results were obtained during the pre-epidemic (AOR=0.87; 95% CI 0.79 to 0.95), epidemic (AOR=0.89; 95% CI 0.82 to 0.96) and postepidemic (AOR=0.83; 95% CI 0.79 to 0.87) periods. No association was found with pneumococcal vaccine (AOR=1.10; 95% CI 1.06 to 1.15). Conclusions Results are compatible with a moderate protective effect of influenza vaccine on AMI in the general population, mostly in primary prevention, although bias due to unmeasured confounders may partly account for the results.Instituto de Salud Carlos IIIMinisterio de Ciencia e InnovaciónHospital Universitario Príncipe de Asturia

Solving Inaccuracies in Anatomical Models for Electrocardiographic Inverse Problem Resolution by Maximizing Reconstruction Quality

[EN] Electrocardiographic Imaging has become an increasingly used technique for non-invasive diagnosis of cardiac arrhythmias, although the need for medical imaging technology to determine the anatomy hinders its introduction in the clinical practice. This paper explores the ability of a new metric based on the inverse reconstruction quality for the location and orientation of the atrial surface inside the torso. Body surface electrical signals from 31 realistic mathematical models and four AF patients were used to estimate the optimal position of the atria inside the torso. The curvature of the L-curve from the Tikhonov method, which was found to be related to the inverse reconstruction quality, was measured after application of deviations in atrial position and orientation. Independent deviations in the atrial position were solved by finding the maximal L-curve curvature with an error of 1.7 +/- 2.4 mm in mathematical models and 9.1 +/- 11.5 mm in patients. For the case of independent angular deviations, the error in location by using the L-curve was 5.8 +/- 7.1 degrees in mathematical models and 12.4 degrees +/- 13.2 degrees in patients. The ability of the L-curve curvature was tested also under superimposed uncertainties in the three axis of translation and in the three axis of rotation, and the error in location was of 2.3 +/- 3.2 mm and 6.4 degrees +/- 7.1 degrees in mathematical models, and 7.9 +/- 10.7 mm and 12.1 degrees +/- 15.5 degrees in patients. The curvature of L-curve is a useful marker for the atrial position and would allow emending the inaccuracies in its location.This work was supported in part by Generalitat Valenciana under Grant ACIF/2013/021, in part by the Instituto de Salud Carlos III, Ministry of Economy and Competitiveness, Spain, under Grant PI13-01882, Grant PI13-00903, Grant PI14/00857, Grant TEC2013-46067-R, and Grant DTS16/00160, in part by the Spanish Society of Cardiology (Grant for Clinical Research in Cardiology 2015), and in part by the Spanish Ministry of Science and Innovation (Red RIC) under Grant PLE2009-0152.Rodrigo Bort, M.; Climent, AM.; Liberos Mascarell, A.; Hernández-Romero, I.; Arenal, A.; Bermejo, J.; Fernández-Avilés, F.... (2018). Solving Inaccuracies in Anatomical Models for Electrocardiographic Inverse Problem Resolution by Maximizing Reconstruction Quality. IEEE Transactions on Medical Imaging. 37(3):733-740. https://doi.org/10.1109/TMI.2017.2707413S73374037

Do Religious Factors Influence the Attitude Toward Organ Donation Among Medical Students? A Spanish Multicenter Study

Introduction Religious factors have conditioned the attitude toward organ donation and transplantation (ODT) since the beginning of transplantation, despite the fact that most religions are in favor of transplantation. Objective To assess the impact of religious beliefs of medical students on their attitude toward ODT. Method Population under study: Medical students in Spanish universities. Study sample: Stratified by geographical area and academic course. Assessment instrument: Attitude ODT questionnaire PCID-DTO-Ríos, anonymous and self-administered. Results Of all students, 42% (n = 3907) declare themselves atheists or agnostics. The remaining 58% (n = 5368) declare themselves to be religious, the majority being Catholic (55%, n = 5102). Of the rest, 0.2% are Muslims (n = 8), 0.1% Protestants (n = 1), and the remaining 2.7% (n = 257) indicate other religious doctrines but do not want to specify it. Regarding their attitude toward ODT, those who consider themselves atheists or agnostics have a more favorable attitude than those who consider themselves religious (84% versus 76%; P < .001). Among those who follow some kind of religion, Catholics are more in favor of ODT than non-Catholics (77% vs 64%, P < .001). Note that among the religious, only 57% (n = 3050) know which religion is in favor of transplantation, while 22% (n = 1,152) consider that it has not been pronounced on the matter, 13% (n = 723) think the religion is against donation, and the remaining 8% (n = 443) do not know. Conclusion The religion professed by medical students conditions their attitude toward donation, with the atheists and agnostics being more in favor of donation.Sin financiación0.784 JCR (2019) Q4, 155/158 Immunology, 191/210 Surgery, 24/24 Transplantation0.363 SJR (2019) Q3, 254/451 Surgery, 27/41 TransplantationNo data IDR 2019UE

Hematoma Asfixiante Tardío.

En la práctica anestésica diaria, con el objetivo de monitorizar la presión venosa central para control hemodinámico (precarga, introducir un swan ganz para vigilar la presión arterial pulmonar...) o infundir drogas vasopresoras, se canaliza una vía venosa central, yugular o subclavia. Aunque la tasa complicaciones es baja, esta técnica no está exenta de riesgos: hemotórax, pseudoaneurisma, fístula arterio-venosa, lesión vascular venosa, hematoma, punción arterial, entre otras. La tasa de punción arterial durante el proceso de canalización de una vía central varía del 3,7 al 8% según las distintas series y la aparición de un hematoma está entorno al 0,8%. Los hematomas asfixiantes secundarios a la punción arterial durante la canalización de una vía central son extremadamente raros, y desgraciadamente de diagnóstico tardío. Normalmente ocurren tras una punción arterial, la mayoría de las veces de la arteria carótida, seguida de la dilatación y/o canalización de la misma (rara vez se dan tras punción en arteria subclavia y/o punción única arterial sin dilatación y/o canalización) y mayoritariamente en pacientes con factores de riesgo tales como: alteraciones de la coagulación o tratamiento antiagregante y/o anticoagulante