264 research outputs found
Daily Solar Energy Estimation for Minimizing Energy Storage Requirements in PV Power Plants
This paper proposes an optimized energy management strategy (EMS) for photovoltaic (PV) power plants with energy storage (ES) based on the estimation of the daily solar energy production. This EMS produces a constant-by-hours power reference which mitigates the stochastic nature of PV production typically associated to the solar resource, and enables PV power plants to take part in the day and intraday electricity markets. The possibility of using the intraday market sessions to refine the plant's power reference paves the way to minimizing the energy capacity ratings of the ES system required to operate the PV power plant without incurring excessive production deviations. This proposal is analyzed on an annual basis using actual irradiance data and theoretical irradiance models extracted from official databases
Predictive Power Control for PV Plants With Energy Storage
This work presents a model predictive control (MPC) approach to manage in real-time the energy generated by a grid-tied photovoltaic (PV) power plant with energy storage (ES), optimizing its economic revenue. This MPC approach stands out because, when a long enough prediction horizon is used, the saturation of the ES system (ESS) can be advanced by means of a prediction model of the PV panels production. Therefore, the PV+ES power plant can modify its production so as to manage the power deviations with regard to that committed in the daily and intraday electricity markets, with the objective of reducing economic penalties. The initial power commitment is supposed in this work to be given by a higher level energy management operator. By a proper definition of its objective function, the predictive control allows us to economically optimize the PV+ES power plant performance. This control strategy is tested in simulations with actual data measured for different days with varying meteorological conditions. Results provide a good reference on the economic benefits which can be obtained thanks to the MPC introduction
Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient
This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.Fil: Pérez Rodríguez, Michael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Hidalgo, Melisa Jazmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Mendoza, Alberto. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: González, Lucy T.. Instituto Tecnologico de Monterrey. Escuela de Ingenieria y Ciencias.; MéxicoFil: Longoria Rodríguez, Francisco. Centro de Investigacion En Materiales Avanzados; MéxicoFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Pellerano, Roberto Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin
Geographical origin identification of mandarin fruits by analyzing fingerprint signatures based on multielemental composition
Given rising traders and consumers concerns, the global food industry is increasingly demanding authentic and traceable products. Consequently, there is a heightened focus on verifying geographical authenticity as food quality assurance. In this work, we assessed pattern recognition approaches based on elemental predictors to discern the provenance of mandarin juices from three distinct citrus-producing zones located in the Northeast region of Argentina. A total of 202 samples originating from two cultivars were prepared through microwave-assisted acid digestion and analyzed by microwave plasma atomic emission spectroscopy (MP-AES). Later, we applied linear discriminant analysis (LDA), k-nearest neighbor (k-NN), support vector machine (SVM), and random forest (RF) to the element data obtained. SVM accomplished the best classification performance with a 95.1% success rate, for which it was selected for citrus samples authentication. The proposed method highlights the capability of mineral profiles in accurately identifying the genuine origin of mandarin juices. By implementing this model in the food supply chain, it can prevent mislabeling fraud, thereby contributing to consumer protection.Fil: Hidalgo, Melisa Jazmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Gaiad, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Mendoza, Alberto. Instituto Tecnologico de Monterrey.; MéxicoFil: Pérez Rodríguez, Michael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Instituto Tecnologico de Monterrey.; MéxicoFil: Pellerano, Roberto Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin
The Ophiuchus DIsc Survey Employing ALMA (ODISEA). II. The effect of stellar multiplicity on disc properties
We present Adaptive Optics (AO) near infrared (NIR) observations using
VLT/NACO and Keck/NIRC2 of ODISEA targets. ODISEA is an ALMA survey of the
entire population of circumstellar discs in the Ophiuchus molecular cloud. From
the whole sample of ODISEA we select all the discs that are not already
observed in the NIR with AO and that are observable with NACO or NIRC2. The
NIR-ODISEA survey consists of 147 stars observed in NIR AO imaging for the
first time, as well as revisiting almost all the binary systems of Ophiuchus
present in the literature (20 out of 21). In total, we detect 20 new binary
systems and one triple system. For each of them we calculate the projected
separation and position angle of the companion, as well as their NIR and
millimeter flux ratios. From the NIR contrast we derived the masses of the
secondaries, finding that 9 of them are in the sub-stellar regime (30-50
\MJup). Discs in multiple systems reach a maximum total dust mass of 50
M, while discs in single stars can reach a dust mass of 200
M. Discs with masses above 10 M are found only around
binaries with projected separations larger than 110 au. The maximum disc
size is also larger around single star than binaries. However, since most discs
in Ophiuchus are very small and low-mass, the effect of visual binaries is
relatively weak in the general disc population.Comment: 13 pages, 13 figures, 4 tables. Published in MNRA
ALMA observations of Elias 2–24: a protoplanetary disk with multiple gaps in the Ophiuchus molecular cloud
We present ALMA 1.3 mm continuum observations at 0. 2 (25 au) resolution of Elias 2–24, one of the largest and brightest protoplanetary disks in the Ophiuchus Molecular Cloud, and we report the presence of three partially resolved concentric gaps located at ∼20, 52, and 87 au from the star. We perform radiative transfer modeling of the disk to constrain its surface density and temperature radial profile and place the disk structure in the context of mechanisms capable of forming narrow gaps such as condensation fronts and dynamical clearing by actively forming planets. In particular, we estimate the disk temperature at the locations of the gaps to be 23, 15, and 12 K (at 20, 52, and 87 au, respectively), very close to the expected snowlines of CO (23–28 K) and N2 (12–15 K). Similarly, by assuming that the widths of the gaps correspond to 4–8× the Hill radii of forming planets (as suggested by numerical simulations), we estimate planet masses in the range of 0.2 1.5 – MJup, 1.0 8.0 – MJup, and 0.02 0.15 – MJup for the inner, middle, and outer gap, respectively. Given the surface density profile of the disk, the amount of “missing mass” at the location of each one of these gaps (between 4 and 20 MJup) is more than sufficient to account for the formation of such planets.Fil: Cieza, Lucas A.. Universidad Diego Portales; ChileFil: Casassus, Simon. Universidad de Chile; ChileFil: Pérez, Sebastian. Universidad de Chile; ChileFil: Hales, Antonio. Alma Observatory; ChileFil: Cárcamo, Miguel. Universidad de Chile; ChileFil: Ansdell, Megan. University of California at Berkeley; Estados UnidosFil: Avenhaus, Henning. Universitat Zurich; SuizaFil: Bayo, Amelia. Universidad de Valparaiso; ChileFil: Bertrang, Gesa H.-M.. Universidad Diego Portales; ChileFil: Cánovas, Hector. Agencia Espacial Europea; EspañaFil: Christiaens, Valentin. Universidad de Chile; ChileFil: Dent, William. Alma Observatory; ChileFil: Ferrero, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Gamen, Roberto Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Olofsson, Johan. Universidad de Valparaiso; ChileFil: Orcajo, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Osses, Axel. Universidad de Chile; ChileFil: Peña Ramirez, Karla. Universidad de Antofagasta; ChileFil: Principe, David. Massachusetts Institute of Technology; Estados UnidosFil: Ruíz Rodríguez, Dary. Rochester Institute Of Technology; Estados UnidosFil: Schreiber, Matthias R.. Universidad de Valparaiso; ChileFil: Plas, Gerrit van der. Univ. Grenoble Alpes; SuizaFil: Williams, Jonathan P.. Institute For Astronomy, University Of Hawaii; Estados UnidosFil: Zurlo, Alice. Universidad Diego Portales; Chil
Whole-Blood Mitochondrial DNA Copies Are Associated With the Prognosis of Acute Respiratory Distress Syndrome After Sepsis.
https://pubmed.ncbi.nlm.nih.gov/34557198/#:~:text=Resumen-,El%20s%C3%ADndrome%20de%20dificultad%20respiratoria%20aguda%20(SDRA)%20es%20un%20proceso,v%C3%ADnculos%20mec%C3%A1nicos%20de%20esta%20observaci%C3%B3n%20con%20la%20patogenia%20del%20SDRA.,-Palabras%20clave%3A%20SDR
MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure
Acute heart failure; Acute myocardial infarction; ElderlyInsuficiència cardíaca aguda; Infart agut de miocardi; Gent granInsuficiencia cardíaca aguda; Infarto agudo de miocardio; AncianoBackground
Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF).
Purpose
To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI.
Study Type
Prospective.
Population
Multicenter registry of 759 reperfused STEMI patients (23.3% elderly).
Field Strength/Sequence
1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences.
Assessment
One-week MRI-derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI-derived LVEF as preserved (p-LVEF, ≥50%), mildly reduced (mr-LVEF, 41%–49%), or reduced (r-LVEF, ≤40%). Median follow-up was 5 [2.33–7.54] years.
Statistical Tests
Univariable (Student's t, Mann–Whitney U, chi-square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous-time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant.
Results
Over the follow-up period, 79 (10.4%) patients presented AHF. MRI-LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91–0.98]) and elderly patients (HR 0.94 [0.91–0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p-LVEF) was noted in patients with r-LVEF both in nonelderly (HR 11.25 [5.67–22.32]) and elderly patients (HR 7.55 [3.29–17.34]). However, the mr-LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54–8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients.
Data Conclusion
MRI-derived p-LVEF confers a favorable prognosis and r-LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr-LVEF category in the elderly group.
Evidence Level
2.
Technical Efficacy
Stage 2.Grant sponsor: This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (grant numbers PI20/00637, PI15/00531, and CIBERCV16/11/00486, CIBERCV16/11/00420, CIBERCV16/11/00479, and CM21/00175 to V.M.-G.), Fundació La Marató TV3 (grant 20153030-31-32), La Caixa Banking Foundation (HR17-00527) and by Conselleria de Educación – Generalitat Valenciana (PROMETEO/2021/008). J.G. acknowledges financial support from the “Agencia Estatal de Investigación” (grant FJC2020-043981-I/AEI/10.13039/501100011033)
Percepción de riesgo ante el cambio climático en estudiantes de Medicina de la Universidad de Ciencias Médicas de La Habana
Introduction: the study of the incidence of climate change on human health makes it possible to design and integrate protection and prevention measures.Objective: to characterize the risk perception of medical students at the University of Medical Sciences of Havana on the effects of climate change on human health.Methods: observational, descriptive and cross-sectional study between January and April 2021. The sample consisted of 166 medical students from the University of Medical Sciences of Havana. The information was obtained through a Google form.Results: 87,95 % of the students evaluated climate change as a harmful phenomenon; 77,72 % considered it an influential factor in the mortality figures. More than 80 % identified vulnerability in their communities and personal health. 96,98 % recognized the role of climate change in the genesis of diseases. 30,2 % related climate change to respiratory diseases and 13,25 % to infectious diseases. 77,71 % of those surveyed considered climate change as a phenomenon related to outbreaks of cholera and malaria, and 50 % with yellow fever and dengue.Conclusions: there was a perception by students of medical sciences in Havana about climate change and its relationship to human health. Students identify the effect of climate change on the genesis of infectious diseases such as cholera and malaria, but to a lesser extent with respiratory diseases.Introducción: el estudio de la incidencia del cambio climático sobre la salud humana posibilita diseñar e integrar medidas de protección y prevención.Objetivo: caracterizar la percepción de riesgo de los estudiantes de medicina de la Universidad de Ciencias Médicas de La Habana sobre los efectos del cambio climático en la salud humana.Métodos: estudio observacional, descriptivo y transversal entre enero y abril de 2021. La muestra estuvo constituida por 166 estudiantes de Medicina de la Universidad de Ciencias Médicas de La Habana. La información fue obtenida mediante un formulario de Google.Resultados: el 87,95 % de los estudiantes evaluó al cambio climático como un fenómeno dañino; el 77,72 % lo consideró un factor influyente en las cifras de mortalidad. Más del 80 % identificó vulnerabilidad en sus comunidades y salud personal. El 96,98 % reconoció el papel del cambio climático en la génesis de enfermedades. El 30,2 % relacionó el cambio climático con enfermedades respiratorias y el 13,25 % con enfermedades infecciosas. El 77,71 % de los encuestados consideró el cambio climático como fenómeno relacionado a brotes de cólera y malaria, y el 50 % con la fiebre amarilla y el dengue.Conclusiones: existió una percepción por parte de los estudiantes de las ciencias médicas de La Habana sobre el cambio climático y su relación a la salud humana. Los estudiantes identifican el efecto del cambio climático en la génesis de enfermedades infectocontagiosas como cólera y malaria, pero en menor medida con enfermedades respiratorias.
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