1,868 research outputs found
Sincrofasores y su aplicación en control de área amplia en sistemas de potencia
El presente trabajo tiene como objetivo principal de aclarar cómo funcionan las PMU o sincrofasores y sus características fundamentales. En consecuencia a lo largo de este documento se explica la arquitectura básica de interconexión de Sincrofasores orientada a las aplicaciones de monitoreo y control de áreas amplias, y se diseña una estrategia básica de monitoreo y control remedial que demuestra las ventajas de la aplicación de sincrofasores en este tipo de metodologías de control. Al final del documento se realizan pruebas al esquema de control planteado a través de simulaciones con el software de análisis de sistemas de potencia NEPLANProyecto de Grado (Ingeniero Electricista)-- Universidad Autónoma de Occidente, 2012PregradoIngeniero(a) Electricist
Selective arterial embolization as an alternative modality treatment prior to mandibular aneursymal bone cyst surgical curettage : case report
ABC (Aneurysmal bone cyst) is a rare, benign and osteolytic lesion. Diagnosis of ABC can be challenging because of its uncommon radiographic and clinical presentation. The case of an 8-year-old female with a rapidly growing painful swelling in her left m
Simulation of atmospheric microbursts using a numerical mesoscale model at high spatiotemporal resolution
Atmospheric microbursts are low‐level meteorological events that can produce significant damage on the surface and pose a major risk to aircraft flying close to the ground. Studies and ad hoc numerical models have been developed to understand the origin and dynamics of the microburst; nevertheless, there are few researches of the phenomenon using global and mesoscale models. This is mainly due to the limitations in resolution, as microbursts normally span for less than 4 km and 20 min. In this paper, the Weather esearch and Forecasting model is used at resolutions of 400 m and 3 min to test if it can properly capture the variables and dynamics of high‐reflectivity microbursts. Several microphysics and planetary boundary layer parametrizations are tested to find the best model configuration for the simulation of this kind of episodes. General conditions are evaluated by using thermodynamic diagrams. Surface and vertical wind speed, reflectivity, precipitation, and other variables for each simulated event are compared with observations, and the model's sensitivity to the variables is assessed. The dynamics and evolution of the microburst is evaluated using different plots of a chosen event. The results show that the model is able to reproduce high‐reflectivity microbursts in accordance with observations, although there is a tendency to underestimate the intensity of variables, most markedly on the wind vertical velocity. Regarding the microphysics schemes, the Morrison parametrization performs better than the WRF single‐moment 6‐class scheme. No major differences are found between the Mellor‐Yamada‐Janjic and the Mellor‐Yamada‐Nakanishi‐Niino planetary boundary layer parametrizations.This work is supported by the Interdisciplinary Mathematics Institute of the Complutense University of Madrid and the following research projects: METEORISK (RTC‐2014‐1872‐5), PCIN‐2014‐013‐C07‐04, PCIN‐2016‐080 (UE ERANET Plus NEWA Project), ESP2013‐47816‐C4‐4‐P, CGL2010‐15930, CGL2016‐81828‐REDT, FEI‐EU‐17‐16, and SAFEFLIGHT GL2016‐78702‐C2‐1‐R and CGL2016‐78702‐C2‐2‐R). This research is founded by the Spanish Ministry of Economy and Enterprise under the framework of the SAFEFLIGHT research project (CGL2016‐78702‐C2‐1‐R and CGL2016‐78702‐C2‐2‐R)
Influence of vermicompost humic acid on chlorophyll content and acclimatization in banana clone, Enano Guantanamero
Vermicompost humic acids (VHA) promote plants’ growth because they have similar effects with auxins. The aim of this research was to evaluate the effect of VHA in some physiological indicators in the micropropagation and acclimatization phase of banana clone Enano Guantanamero. Six concentrations were used (0, 10, 20, 30, 40 and 50 mg L-1) to evaluate in vitro the number of leaves, total chlorophyll content and chlorophyll a-b; also in the acclimatization phase, the plant height, stem diameter and number of leaves at three different times (transplant, 25 days and at the end of this phase- 50 days) were determined. Root length and roots dry weight were evaluated at the end of the acclimatization. VHA applied improved total chlorophyll, chlorophyll a-b at concentrations of 20 and 50 mg L-1, but not the number of leaves. In the acclimatization stage, plants height at the end of this period (50 days) were higher with 10 mg L-1 (T1) VHA, the number of leaves increased at 40 mg L-1 (T4) and the stem diameter was higher at both concentrations. In the evaluation of roots length, there were no significant differences, but the number of leaves was higher at 10 and 40 mg L-1 (T1 and T4) and it decreased at 50 mg L-1 (T5); roots dry weight increased at 40 mg L-1 (T4). VHA promoted chlorophyll content under in vitro conditions, it reduced the period of acclimatization of banana clone Enano Guantanamero, led to a better growth of plants, and it saved time and resources.Key words: Acclimatization, humic acid, in vitro crop, Musa sp
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.This research was carried out in the framework of the SAFEFLIGHT project, financed by MINECO (CGL2016‐78702) and LE240P18 project (Junta de Castilla y León)
Mountain waves analysis in the vicinity of the Madrid-Barajas Airport using the WRF model
Turbulence and aircraft icing associated with mountain waves are weather phenomena potentially affecting aviation safety. In this
paper, these weather phenomena are analysed in the vicinity of the Adolfo Su´arez Madrid-Barajas Airport (Spain). Mountain
waves are formed in this area due to the proximity of the Guadarrama mountain range. Twenty different weather research and
forecasting (WRF) model configurations are evaluated in an initial analysis. .is shows the incompetence of some experiments to
capture the phenomenon. .e two experiments showing the best results are used to simulate thirteen episodes with observed
mountain waves. Simulated pseudosatellite images are validated using satellite observations, and an analysis is performed through
several skill scores applied to brightness temperature. Few differences are found among the different skill scores. Nevertheless, the
.ompson microphysics scheme combined with the Yonsei university PBL scheme shows the best results. .e simulations
produced by this scheme are used to evaluate the characteristic variables of the mountain wave episodes at windward and leeward
and over the mountain. .e results show that north-northwest wind directions, moderate wind velocities, and neutral or slightly
stable conditions are the main features for the episodes evaluated. In addition, a case study is analysed to evidence the WRF ability
to properly detect turbulence and icing associated with mountain waves, even when there is no visual evidence available..is work was partially supported by the following research
projects: PID2019-105306RB-I00, PCIN-2014-013-C07-04,
and PCIN2016-080 (UE ERA-NET Plus NEWA Project),
CGL2016-78702-C2-1-R and CGL2016-78702-C2-2-R
(SAFEFLIGHT Project), FEI-EU-17-16 and SPESMARTand
SPESVALE (ECMWF Special Projects)
ECG study in practical labs for biomedical engineering training
Non-invasive biomedical measurements are one of the most important technological contributions whitin the biomedical engineering field. On this paper, a dual laboratory session student oriented is designed to simulate and implement a cardial signal monitor. During the first session, ORCAD PSpice software is used to simulate the whole process. The students can acquire knowledge on the process by configuring and running both the instrumentation amplifier and a passive filter to improve the signal quality. The second session requires from the student basic laboratory skills to use a specific printed circuit board (PCB) to measure its very own cardiac potential. As a result, from this session, the student can visualize the ECG signal acquired directly on the laboratory oscilloscope
El impacto del invierno cálido del 2007 en los rendimientos paperos de Cuba
Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008
Cd38 deficiency ameliorates chronic graft versus Host disease murine lupus via a b-cell dependent mechanism
Trabajo presentado en el II Congreso investigación PTS, celebrado en Granada (España) del 09 al 11 de febrero de 2022.Absence of mouse cell surface receptor CD38 in Cd38-/- mice suggests that this receptor acts as positive regulator of inflammatory and autoimmune responses. Here we report that in the setting of a chronic graft versus host disease (cGVHD) lupus model induced by the transfer of B6.C-H2bm12/KhEg (bm12) spleen cells into co-isogenic Cd38-/- B6 mice causes milder lupus-like autoimmunity with lower levels of anti-ssDNA autoantibodies than the transfer of bm12 spleen cells into WT B6 mice. I In addition, significantly lower percentages of Tfh cells, as well as GC B cells, plasma cells and T-bet+CD11chi B cells are observed in Cd38-/- mice than in WT mice, while the expansion of Treg cells, and Tfr cells is normal, suggesting that the ability of Cd38-/- B cells to respond to allogeneic help from bm12 CD4+ T cells is greatly diminished. The frequencies of T-bet+CD11chi B cells, which are considered the precursors of the autoantibody secreting cells, correlate with anti-ssDNA autoantibody serum levels, with IL-27, and sCD40L. Proteomics profiling of spleens from WT cGVHD mice reflects a STAT1-driven type I IFN-signature, which is absent in Cd38-/- cGVHD mice. Kidney, spleen and liver inflammation was mild and resolved faster in Cd38-/- cGVHD mice than in WT cGVHD mice. We conclude that in B cells CD38 functions as a modulator receptor that controls autoimmune responses
Engelamiento en vuelo: caso de estudio sobre la sierra de Guadarrama
Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.Un pronóstico meteorológico preciso es indispensable para la aviación, ya que del mismo depende tanto la gestión del vuelo como de los riesgos a los que está expuesta. Las condiciones meteorológicas adversas son la causa de múltiples incidentes y accidentes de aviación, constituyendo la presencia del engelamiento una de las situaciones más peligrosas para la seguridad en vuelo (Caliskan & Hajiyev, 2013). Sin embargo, los modelos numéricos suelen sobreestimar la presencia de agua en fase sólida y subestimar la presencia de agua subfundida, de tal manera que no se pronostica con precisión la concentración de SLD (Fernández-González, et al. 2014). Esto genera que el pronóstico de las condiciones de engelamiento en meteorología aeronáutica sea manifiestamente mejorable. A través de un caso de estudio, este trabajo evalúa, la idoneidad de la información meteorológica aeronáutica previa a un vuelo y analiza si es adecuada para anticipar casos de engelamiento. Se analizan las condiciones atmosféricas a escala sinóptica y posteriormente, se modelizan las condiciones a mesoescala para estudiar la predictibilidad del episodio. Finalmente se investigan posibles herramientas de nowcasting usando teledetección
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