68 research outputs found
Remote supervision and fault detection on OPC monitored PV systems
This paper presents a new approach for automatic supervision and remote fault detection of grid connected photovoltaic (PV) systems by means of OPC technology-based monitoring. The use of standard OPC for monitoring enables data acquisition from a set of devices that use different communication protocols as inverters or other electronic devices present in PV systems enabling universal connectivity and interoperability. Using the OPC standard allows promoting interoperation of software objects in distributed-heterogeneous environments and also allows incorporating in the system remote supervision and diagnosis for the evaluation of grid connected PV facilities. The supervision system analyses the monitored data and evaluates the expected behaviour of main parameters of the PV array: Output voltage, current and power. The monitored data and evaluated parameters are used by the fault detection procedure in order to identify possible faults present in the PV system. The methodology presented has been experimentally validated in the supervision of a grid connected PV system located in Spain. Results obtained show that the combination of OPC monitoring along with the supervision and fault detection procedure is a robust tool that can be very useful in the field of remote supervision and diagnosis of grid connected PV systems. The RMSE between real monitored data and results obtained from the modelling of the PV array were below 3.6% for all parameters even in cloudy days.Peer ReviewedPostprint (published version
Riqueza, abundancia relativa y actividad de los mamíferos de una reserva en restauración en Costa Rica
ABSTRACT. “Richness, relative abundance and activity of medium and large mammals of a reserve under restoration in Costa Rica”. Introduction: Private protected areas are a valuable complement to national systems of protected areas. The Sierra Zapote Reserve in Abangares, Costa Rica, established in 2000, protects 70 ha of advanced secondary forest, regenerating secondary forest and primary riparian forest. It is expected to favor faunal communities, like medium and large mammals, which are among the species most threatened by habitat loss and fragmentation; nevertheless; there is a lack of recent faunal assessments at Sierra Zapote. Objective: To assess the richness, relative abundance and activity patterns of these mammals in the reserve. Methods: From May 2020 to July 2021, we kept five camera-traps at strategic sites and programmed them to be active 24 hours a day (0,3 seconds between shots). We checked the cameras every one or two months and also extracted temperature and moon phase data. Results: We obtained 758 independent records of mammals with a 2 135-day photo-trapping effort. The most abundant species were Nasua narica (relative abundance index RAI = 14,6, N= 312) and Didelphis marsupialis (RAI = 6,1, N= 130). The least abundant were Herpailurus yagouaroundi and Procyon lotor (RAI = 0,05, N= 1). Most species are nocturnal and only the peccary (Pecari tajacu), the coati (Nasua narica) and the agouti (Dasyprocta punctata) have mostly diurnal activity. The puma (Puma concolor) occurs at the reserve. Conclusion: The activity patterns were as expected; for the reserve size, a richness of 19 species is comparatively high. The presence of the puma, an indicator of good ecosystem health, hints at the importance of the reserve’s restoration process.RESUMEN. Introducción: Las áreas protegidas privadas son un complemento valioso para los sistemas nacionales de áreas protegidas. La Reserva Sierra Zapote en Abangares, Costa Rica, establecida en 2000, protege 70 ha de bosque secundario avanzado, bosque secundario en regeneración y bosque ribereño primario. Se espera que favorezca a las comunidades faunísticas, como los mamíferos medianos y grandes, que se encuentran entre las especies más amenazadas por la pérdida y fragmentación del hábitat; actualmente existe la necesidad de evaluaciones faunísticas en Sierra Zapote. Objetivo: Evaluar la riqueza, abundancia relativa y patrones de actividad de estos mamíferos en la reserva. Métodos: De mayo de 2020 a julio de 2021, mantuvimos cinco cámaras trampa en sitios estratégicos y las programamos para que estuvieran activas las 24 horas del día (0,3 segundos entre disparos). Revisamos las cámaras cada 1-2 meses y también extrajimos datos de temperatura y fase lunar. Resultados: Obtuvimos 758 registros independientes de mamíferos con un esfuerzo de fototrampeo de 2 135 días. Las especies más abundantes fueron Nasua narica (índice de abundancia relativa RAI = 14,6, N= 312) y Didelphis marsupialis (RAI = 6,1, N= 130). Los menos abundantes fueron Herpailurus yagouaroundi y Procyon lotor (RAI = 0,05, N= 1). La mayoría de las especies son nocturnas y solo el saíno (Pecari tajacu), el pizote (Nasua narica) y la guatusa (Dasyprocta punctata) tienen actividad mayoritariamente diurna. El puma (Puma concolor) también habita en la reserva. Conclusión: Los patrones de actividad fueron los esperados; para el tamaño de la reserva, una riqueza de 19 especies es comparativamente alta. La presencia del puma, indicador de buena salud del ecosistema, deja entrever la importancia del proceso de restauración de la reserva
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Reflexiones desde el Aula de Clases en Arquitectura
Las líneas que siguen a continuación son el resultado de un ejercicio académico de estudiantes de noveno semestre del Programa de Arquitectura de la Universidad de la Costa, en el marco de la asignatura Electiva en Proyecto de Investigación II dirigida por el profesor Samuel Padilla-Llano, donde se aborda la investigación como un proceso de coproducción del conocimiento a través de metodologías y estrategias pedagógicas en el aula que permiten al estudiante deconstruir conceptos y elaborar colectivamente posturas y argumentación que aporten a la elaboración de ejercicios investigativos que decantan en productos de investigación y que reflejan en aprendizaje y el dominio de las competencias genéricas y específicas que consolidan su formación académica y profesional. La metodología de este ejercicio rápido de escritura está basada en las lecturas previas de fuentes primarias y bibliografía estructurada en las temáticas desarrolladas en la asignatura las cuales tienen un enfoque en la relación existente entre la arquitectura y los saberes relacionados con la salud y la medicina. Durante una sesión de clases de 3 horas se realiza un debate para socializar y puesta en común de las ideas. Posteriormente cada estudiante dedica un tiempo de la misma sesión a la elaboración del escrito bajo los parámetros indicados (ser reflexiones inéditas, usar citas bibliográficas a partir de las lecturas, tener control del sistema de citación APA). Luego se socializa el resultado y se organiza en documento colectivo y se prepara la publicación conjunta como resultado del trabajo reflexivo. Esta serie de lecturas realizadas durante el curso plantea la lectura semanal de dos artículos. Estos artículos que referencian trabajos locales, nacionales e internacionales, abordan elementos que ponen en discusión las formas de habitar del ser humano y la calidad de vida en los espacios donde trascurre el habitar. Preguntarnos sobre la calidad del hábitat humano y los aspectos que la definen, también es un acto que los arquitectos desde una disciplina concentrada en el hacer espacios para habitar (la casa, la calle, el barrio, la ciudad, etc.), debemos asumir con vocación y conciencia del efecto y la importancia que tiene sobre la vida del ser (o seres) que habitan el espacio. Y desde esa conciencia, el hacer la arquitectura es el arte de pensar, proyectar y configurar formas de habitar en el mudo
Guías colombianas de electrofisiología no invasiva
Los métodos diagnósticos no invasivos son el pilar inicial del estudio de cualquier paciente con una
patología en particular, de ahí que sean los exámenes más solicitados y constituyan una importante carga
en costos para un sistema de salud.Q4Guías1-12
Global Retinoblastoma Presentation and Analysis by National Income Level.
Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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