27 research outputs found
Estudio de la resistencia a compresión de morteros fabricados con conglomerante compuesto de polvo de vidrio
Esta investigación evalúa la resistencia de morteros realizados con mezclas de diferentes composiciones, donde una parte del conglomerante tradicional es sustituido por el polvo de vidrio para analizar de una forma sencilla las características mecánicas de las muestras reactivas obtenidas de esta forma. Los ensayos se han realizado con morteros. Para facilitar las reacciones se añaden a las mezclas objeto del análisis diferentes reactivos: se mezcla el polvo de vidrio con reactivos básicos, lo que permite la obtención de condiciones de pH superiores a 12, en las que el vidrio sodo-cálcico es muy reactivo. Analizadas las diferentes probetas de morteros, se observa que el polvo de vidrio, así como su granulometría, juegan un importante papel en el aumento de las resistencias mecánicas a compresión de las mezclas
Effect of viral storm in patients admitted to intensive care units with severe COVID-19 in Spain: a multicentre, prospective, cohort study
Background: The contribution of the virus to the pathogenesis of severe COVID-19 is still unclear. We aimed to evaluate associations between viral RNA load in plasma and host response, complications, and deaths in critically ill patients with COVID-19. Methods: We did a prospective cohort study across 23 hospitals in Spain. We included patients aged 18 years or older with laboratory-confirmed SARS-CoV-2 infection who were admitted to an intensive care unit between March 16, 2020, and Feb 27, 2021. RNA of the SARS-CoV-2 nucleocapsid region 1 (N1) was quantified in plasma samples collected from patients in the first 48 h following admission, using digital PCR. Patients were grouped on the basis of N1 quantity: VIR-N1-Zero ([removed]2747 N1 copies per mL). The primary outcome was all-cause death within 90 days after admission. We evaluated odds ratios (ORs) for the primary outcome between groups using a logistic regression analysis. Findings: 1068 patients met the inclusion criteria, of whom 117 had insufficient plasma samples and 115 had key information missing. 836 patients were included in the analysis, of whom 403 (48%) were in the VIR-N1-Low group, 283 (34%) were in the VIR-N1-Storm group, and 150 (18%) were in the VIR-N1-Zero group. Overall, patients in the VIR-N1-Storm group had the most severe disease: 266 (94%) of 283 patients received invasive mechanical ventilation (IMV), 116 (41%) developed acute kidney injury, 180 (65%) had secondary infections, and 148 (52%) died within 90 days. Patients in the VIR-N1-Zero group had the least severe disease: 81 (54%) of 150 received IMV, 34 (23%) developed acute kidney injury, 47 (32%) had secondary infections, and 26 (17%) died within 90 days (OR for death 0·30, 95% CI 0·16–0·55; p<0·0001, compared with the VIR-N1-Storm group). 106 (26%) of 403 patients in the VIR-N1-Low group died within 90 days (OR for death 0·39, 95% CI 0·26–0·57; p[removed]11 página
SPGCam: A specifically tailored camera for solar observations
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Designing a new astronomical instrument typically challenges the available cameras on the market. In many cases, no camera can fulfill the requirements of the instrument in terms of photon budget, speed, and even interfaces with the rest of the instrument. In this situation, the only options are to either downgrade the performance of the instrument or design new cameras from scratch, provided it is possible to identify a compliant detector. The latter is the case of the SPGCams, the cameras developed to be used with the Tunable Magnetograph (TuMag) and the Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for the Sunrise iii mission. SPGCams have been designed, developed, and built entirely in-house by the Solar Physics Group (SPG) at the Instituto de Astrofísica de Andalucía (IAA-CSIC). We report here on the scientific rationale and system engineering requirements set by the two instruments that drove the development, as well as on the technical details and trade-offs used to fulfill the specifications. The cameras were fully verified before the flight, and results from the assembly and verification campaign are presented as well. SPGCams share the design, although some parametric features differentiate the visible cameras (for TuMag) and the IR ones (for SCIP). Even though they were specifically developed for the Sunrise iii mission, the robust and careful design makes them suitable for different applications in other astronomical instruments. © 2023 Orozco Suárez, Álvarez García, López Jiménez, Balaguer Jiménez, Hernández Expósito, Labrousse, Bailén, Bustamante Díaz, Bailón Martínez, Aparicio del Moral, Morales Fernández, Sánchez Gómez, Tobaruela Abarca, Moreno Mantas, Ramos Más, Pérez Grande, Piqueras Carreño, Katsukawa, Kubo, Kawabata, Oba, Rodríguez Valido, Magdaleno Castelló and Del Toro Iniesta.This work was funded by the Spanish MCIN/AEI, under projects RTI 2018-096886-B-C5, PID 2021-125325OB-C5, and PCI 2022-135009-2, and co-funded by European FEDER funds, “A way of making Europe,” under grants CEX 2021-001131-S and 10.13039/501100011033.Peer reviewe
Differential clinical characteristics and prognosis of intraventricular conduction defects in patients with chronic heart failure
Intraventricular conduction defects (IVCDs) can impair prognosis of heart failure (HF), but their specific impact is not well established. This study aimed to analyse the clinical profile and outcomes of HF patients with LBBB, right bundle branch block (RBBB), left anterior fascicular block (LAFB), and no IVCDs. Clinical variables and outcomes after a median follow-up of 21 months were analysed in 1762 patients with chronic HF and LBBB (n = 532), RBBB (n = 134), LAFB (n = 154), and no IVCDs (n = 942). LBBB was associated with more marked LV dilation, depressed LVEF, and mitral valve regurgitation. Patients with RBBB presented overt signs of congestive HF and depressed right ventricular motion. The LAFB group presented intermediate clinical characteristics, and patients with no IVCDs were more often women with less enlarged left ventricles and less depressed LVEF. Death occurred in 332 patients (interannual mortality = 10.8%): cardiovascular in 257, extravascular in 61, and of unknown origin in 14 patients. Cardiac death occurred in 230 (pump failure in 171 and sudden death in 59). An adjusted Cox model showed higher risk of cardiac death and pump failure death in the LBBB and RBBB than in the LAFB and the no IVCD groups. LBBB and RBBB are associated with different clinical profiles and both are independent predictors of increased risk of cardiac death in patients with HF. A more favourable prognosis was observed in patients with LAFB and in those free of IVCDs. Further research in HF patients with RBBB is warranted
A 40-year retrospective European radon flux inventory including climatological variability
In this work, a 40-year retrospective European radon flux inventory has been calculated. Average values of the radon exhalation rate, probability distributions and seasonal fluctuations have been obtained. To achieve this, a numerical model of radon transport through finite, heterogeneous and porous media has been implemented, enabling us to calculate the radon exhalation rate of European soils with a horizontal resolution of 0.5' (~1km). Geological, geochemical and climatological parameters derived from European and international databases (FOREGS, HWSD, ERA-40) have been coupled to the model.The theoretical model is based on the fundamental equation of radon transport in porous media, taking into account the dependency of the transport coefficient on temperature and humidity. It also includes a simple model that evaluates the effect of snow cover. In general, the results show wide variations depending on location and season of the year, with a spatial standard deviation close to the annual average value (30Bqm-2h-1) In turn, the seasonal deviation is about 25% of the annual average value.The inventory can be easily integrated into atmospheric transport models acting as baseline that could be used for policy decisions regarding the identification of areas with a high risk of exposure to radon. The gridded data are available for the scientific community upon request. The limitations and sources of errors and uncertainties of the model are also discussed in detail
A short-time method to measure the radon potential of porous materials
The radiological risk associated with the use of solid materials has been traditionally established
according to their radon exhalation rates, the accumulation chamber technique being the most widely
used for the determination of this quantity. However, this coupled methodology has two important
drawbacks: the calculated exhalation rate value depends strongly on the experimental setup used;
hence widely varying values can be calculated for the same material. Furthermore, this technique
usually requires long monitoring times (between 1 and 4 weeks).
In this paper, we present a fast and reproducible method for the determination of radon potential
(as an alternative to the exhalation rate) based on the application of the accumulation chamber
technique. Radon potential is proportional to the emanation coefficient, and can be calculated within
measuring times of less than 24 h. The theoretical basis is developed and the experimental setup is
discussed in detail in this paper.
The procedures for the determination of different experimental parameters (leakage constant, slope
correction) are shown as essential steps for the later determination of the radon potential. In addition,
the robustness of the developed methodology is demonstrated, and the reproducibility tests carried out
with the general system performance are shown. Finally, the radon potential for different materials is
determined, allowing its prompt categorization according to its associated radiological risk
A comparison between active and passive techniques for measurements of radon emanation factors
Some radon related parameters have been determined through two different techniques (passive and active) in soil and phosphogypsum samples. Emanation factors determined through these techniques show a good agreement for soil samples while for phosphogympsum samples appear large discrepancies. In this paper, these discrepancies are analyzed and explained if non-controlled radon leakages in the passive technique are taken into account
Development and operational performance of a single calibration chamber for radon detectors
This work shows the design, setup and performance of a new single radon detector calibration chamber developed at the University of Huelva (Environmental Radioactivity Group). This system is based on a certified radon source and a traceable reference radon detector, which allows radon concentrations inside the chamber radon to be obtained in steady state conditions within a range of 400-22 000 Bq m-3 18 with associated uncertainties in the range of 4%. In addition, the development of a new ad hoc calibration protocol (UHU-RC/01/06 “Rachel”), which is based on the modelling of radon concentration within the chamber, allows it to be used without the reference detector. To do that, a complete characterization and calibration of the different leakage constants and the flow meter reading have been performed. The accuracy and general performance of both working methods for the same chamber (i.e., with and without the reference detector) have been tested by means of their participation in an intercomparison exercise involving five active radon monitors
Machine Learning as a Diagnosis Tool of Groundwater Quality in Zones with High Agricultural Activity (Region of Campo de Cartagena, Murcia, Spain)
Groundwater is humanity’s freshwater pantry, constituting 97% of available freshwater. The 6th Sustainable Development Goal (SDG) of the UN Agenda 2030 promotes “Ensure availability and sustainable management of water and sanitation for all”, which takes special significance in arid or semi-arid regions. The region of Campo de Cartagena (Murcia, Spain) has one of the most technified and productive irrigation systems in Europe. As a result, the groundwater in this zone has serious chemical quality problems. To qualify and predict groundwater quality of this region, which may later facilitate its management, two machine learning models (Naïve-Bayes and Decision-tree) are proposed. These models did not require great computing power and were developed from a reduced number of data using the KNIME (KoNstanz Information MinEr) tool. Their accuracy was tested by the corresponding confusion matrix, providing a high accuracy in both models. The obtained results showed that groundwater quality was higher in the northern and west zones. This may be due to the presence in the north of the Andalusian aquifer, the deepest in Campo de Cartagena, and in the west to the predominance of rainfed crops, where the amount of water available for leaching fertilizers is lower, coming mainly from rainfall