Alpha decay perturbations by atomic effects at extreme conditions

The alpha tunneling effect in the presence of electron screening is calculated within the Debye model. Calculations show that very small effects are predicted by cooling the metal to low temperatures. However the alpha lifetime decay may be reduced by about 15% if solid samples of the alpha emitters are cooled and compressed to relatively high densities. These conditions can be achieved at high pressures by using existing diamond anvil cells (DACs). Even so, practical consequences for speeding-up the decay of actinides (from the nuclear waste) seem to be negligible. Keywords: Alpha decay; Lifetime reduction; Extreme atomic condition

Hybrid reactors: nuclear breeding or energy production?

After reviewing the long-standing tradition on hybrid research, an assessment model is presented in order to characterize the hybrid performance under different objectives. In hybrids, neutron multiplication in the subcritical blanket plays a major role, not only for energy production and nuclear breeding, but also for tritium breeding, which is fundamental requirement in fusion–fission hybrids. All three objectives are better achieved with high values of the neutron multiplication factor (k-eff) with the obvious and fundamental limitation that it cannot reach criticality under any event, particularly, in the case of a loss of coolant accident. This limitation will be very important in the selection of the coolant. Some general considerations will be proposed, as guidelines for assessing the hybrid potential in a given scenario. Those guidelines point out that hybrids can be of great interest for the future of nuclear energy in a framework of Sustainable Development, because they can contribute to the efficient exploitation of nuclear fuels, with very high safety features. Additionally, a proposal is presented on a blanket specially suited for fusion–fission hybrids, although this reactor concept is still under review, and new work is needed for identifying the most suitable blanket composition, which can vary depending on the main objective of the hybrid

Healthcare risk stratification model for emergency departments based on drugs, income and comorbidities: the DICER-score

Background During the last decade, the progressive increase in age and associated chronic comorbidities and polypharmacy. However, assessments of the risk of emergency department (ED) revisiting published to date often neglect patients' pharmacotherapy plans, thus overseeing the Drug-related problems (DRP) risks associated with the therapy burden. The aim of this study is to develop a predictive model for ED revisit, hospital admission, and mortality based on patient's characteristics and pharmacotherapy.MethodsRetrospective cohort study including adult patients visited in the ED (triage 1, 2, or 3) of multiple hospitals in Catalonia (Spain) during 2019. The primary endpoint was a composite of ED visits, hospital admission, or mortality 30 days after ED discharge. The study population was randomly split into a model development (60%) and validation (40%) datasets. The model included age, sex, income level, comorbidity burden, measured with the Adjusted Morbidity Groups (GMA), and number of medications. Forty-four medication groups, associated with medication-related health problems, were assessed using ATC codes. To assess the performance of the different variables, logistic regression was used to build multivariate models for ED revisits. The models were created using a stepwise-forward approach based on the Bayesian Information Criterion (BIC). Area under the curve of the receiving operating characteristics (AUCROC) curve for the primary endpoint was calculated.Results851.649 patients were included; 134.560 (15.8%) revisited the ED within 30 days from discharge, 15.2% were hospitalized and 9.1% died within 30 days from discharge. Four factors (sex, age, GMA, and income level) and 30 ATC groups were identified as risk factors and combined into a final score. The model showed an AUCROC values of 0.720 (95%CI:0.718-0.721) in the development cohort and 0.719 (95%CI.0.717-0.721) in the validation cohort. Three risk categories were generated, with the following scores and estimated risks: low risk: 18.3%; intermediate risk: 40.0%; and high risk: 62.6%.ConclusionThe DICER score allows identifying patients at high risk for ED revisit within 30 days based on sociodemographic, clinical, and pharmacotherapeutic characteristics, being a valuable tool to prioritize interventions on discharge. Risk scores are often used to predict the clinical outcomes of patients in many healthcare settings.To the date, no prediction model of emergency department (ED) visits based on patients' pharmacotherapy, income level, and comorbidities have been developed.We have designed an ED risk score combined four risk factors (sex, age, comorbidity score and income level) and 30 drug categories to identify those patients at high risk of health-care visit

LAVICAD: LAboratori VIrtual de Comunicacions Analògiques i Digitals

Mitjançant el present ajut s’ha ampliat l’aplicació en xarxa LAVICAD (LAboratori VIrtual de COmunicacions Analògiques i Digitals) que s’ofereix de forma integrada dins de la plataforma d’e-learning COM@WEB. LAVICAD és una eina programada en Java i Matlab i està formada per un conjunt de simuladors de la capa física de sistemes de comunicacions. Tots els simuladors es presenten en xarxa i es poden utilitzar pels estudiants des de qualsevol ordinador sense necessitat d’instal·lació de cap tipus de software especial. Durant el curs 2007 2008 s’han desenvolupat entre d’altres dos línies de treball. D’una banda s’ha programat l’applet que emula la capa física de la televisió digital terrestre, com a referent per a l’ensenyament de sistemes de comunicacions avançats. D’altra banda s’ha treballat en la programació de noves funcionalitats de l’eina LAVICAD, que permeten ajudar als professors en el seguiment i avaluació del treball continuat dels estudiants. En particular s’ha programat la generació d’una base de dades que conté la informació dels usuaris que s’han connectat i els resultats obtinguts a l’executar un determinat simulador. Les dues línies desenvolupades han de permetre durant l’actual curs, consolidar l’ús dels diferents simuladors per a la docència de les assignatures implicades al projecte.Peer Reviewe

Desenvolupament de recursos per a la creació i gestió de material docent orientat a l’aprenentatge actiu que faciliti l’adaptació d’assignatures tècniques a l'EEES i la seva aplicació a l’ensenyament de circuits elèctrics

L'autoaprenentatge i l’autoavaluació d’assignatures tècniques requereixen eines de càlcul que no estan disponibles dintre del campus virtual ATENEA, per aquest motiu s’ha incorporat al campus virtual de la UPC el software WIRIS Quizzes, que integra el motor de càlcul matemàtic WIRIS amb el sistema de preguntes de Moodle, ampliant les opcions per a la realització de qüestionaris i facilitant l’adaptació d’assignatures reglades de caràcter tècnic a l'EEES. Els qüestionaris desenvolupats, tant d’autoavaluació com d’avaluació, es particularitzen per cada estudiant aprofitant que WIRIS Quizzes permet incorporar a les preguntes de Moodle elements matemàtics generats de forma aleatòria. Els qüestionaris desenvolupats permeten a l’estudiant escriure tot el desenvolupament de l’exercici amb una sintaxis específica i guardar aquesta resposta, amb el que es millora la informació rebuda pel professor permetent adaptar l’ensenyament a les necessitats dels alumnes. En la línia d’adaptar les assignatures de Circuits Elèctrics a l'EEES s’ha creat l’assignatura virtual “l’ensenyament de circuits elèctrics” al campus virtual de la UPC en la que a part del qüestionaris s’ha afegit el material docent desenvolupat mitjançant l’editor de documents multimèdia EMDOC, aquest material que resta al DMD consta d’apunts amb problemes desenvolupats. També s’han desenvolupat exercicis pràctics amb l’objectiu d’incentivar l’adquisició de coneixements.Peer Reviewe

New methodological approach to estimate the turbulent kinetic energy dissipation rate

Martech 2009 Third Marine Technology Workshop, 19-20 november 2009, Vilanova i la Geltrú, BarcelonaPeer Reviewe

The dilution method: a modelling study

Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB): Advances and challenges for understanding physical-biological interactions in HABs in Stratified Environments, 21-23 August 2012, Moss Landing, United States.-- 1 pageThe estimation of (species-specific) phytoplankton in situ growth rates (µ) is one of the fundamental parameters to understand population dynamics. As explained in the accompanying presentation (Berdalet et al., this workshop), estimating this parameter in the field is highly complex. One of the most accepted method is the dilution technique (Landry & Hasset, 1982; Calbet & Landry, 2004). This method has been designed to simultaneously estimate the grazing by microzooplankton on phytoplankton, another essential parameter to describe the population dynamics. The dilution technique involves the in situ incubations of the organisms in bottles with particular nutrient enrichments at fixed depths. In the presentation, we will explain the main limitations associated to this method, caused by the incubations at a fixed depth, i.e. at fixed light conditions. This may force the photosynthetic organisms to adapt their physiology to new conditions different from the light exposure that would experiment in the natural conditions. Here, we will show the modelling approaches addressed to explore the errors associated to in situ incubations of the organisms at fixed depths. Alternatives to the overcome the errors include the yo-yo approach (i.e. changing the bottles position in the water column) and perform incubations at several depthsPeer Reviewe

Hydrodynamic properties and smallscale turbulence related to different hab events in Alfacs Bay (NW Mediterranean)

Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Modelling Workshop Galway, Ireland, June 2009.-- 1 pageDifferent laboratory experiments have shown the particular biological responses of many dinoflagellate species to small-scale turbulence. However, the relevance of these observations has been rarely tested in the field. In this work we characterized the environmental physical conditions during blooms of two different species, the ichthyotoxic dinoflagellate Karlodinium veneficum occurred on June-July 2007 and the diatom Pseudonitzchia spp. occurred in October 2007 in Alfacs Bay. Over the first bloom event, velocity data were almost continuously recorded by a 2MHz acoustic Doppler current profiler deployed on a fixed station (6 m depth). Additional physical (using a CTD and a SCAMP microstructure probe) and biological (chlorophyll concentration, phytoplankton species composition) parameters were obtained from several sampling points. Meteorological data were provided by a nearby station. During the Pseudonitzchia spp. bloom, only microstructure and biological data were collected along 5 days. We will show our preliminary results on the different scenarios under which both events occurre

Swimming and sinking in a Mediterranean Bay: survival strategies in a stratified and weakly turbulent water column

14th International Conference on Harmful Algae, 1-5 November 2010, Creta, GreeceThe mechanisms underlying the population dynamics of phytoplankton species causing harmful blooms are complex. They result from the interplay of physico-chemical and biological factors to which the organisms respond with a variety of strategies. In this context, the vertical distribution of the organisms in the water column may be crucial for their success as it determines their access to light and nutrients and affects the different strategies regarding reproduction, life cycle, and predator avoidance. Some phytoplankton cells can actively regulate their vertical position through swimming, buoyancy changes and/or sinking provided that they can overcome the turbulent mixing and advection. We collected a two-year time series of biological and physical (turbulence) measurements in Alfacs Bay (Ebre Delta, NW Mediterranean), a shallow estuary (max depth is 6m) and active aquaculture site. We found that while the ichtiotoxic dinoflagellate Karlodinium spp. was mainly located below 4m, the potentially amnesic shellfish toxin producer Pseudonitzschia spp. showed a homogeneous distribution throughout the upper layer of the water column. We used our observations of turbulence intensity to set up a combination of turbulence closure and individual based model (IBM). The model results enable us to evaluate the extent to which the different physical and physiological mechanisms could be involved in creating the observed differential vertical distribution of these two harmful phytoplankton speciesPeer Reviewe