Pseudopotenciales transferibles para elementos de transición en la Teoría del Funcional de la Densidad

El presente trabajo tiene como objetivo la adquisición de conocimientos, tanto teóricos como prácticos, sobre simulaciones computacionales ab-initio de propiedades de materiales nanométricos complejos mediante el uso del código SIESTA (del inglés, Spanish Initiative for Electronic Simulations with Thousands of Atoms). Se entenderán como sistemas complejos aquellos que contengan elementos químicos de transición, cuya principal característica es que presentan electrones localizados del tipo ndx. Algunos ejemplos de este tipo de sistemas pueden ser los óxidos metálicos, los compuestos organometálicos, o las impurezas magnéticas en aleaciones, mientras que entre sus numerosas aplicaciones prácticas están la catálisis, los sensores, la geofísica, el magnetismo, la metalurgia, nuevos materiales nanométricos, etc... Las simulaciones ab-initio (o de primeros principios) describen el comportamiento cuántico de la materia y complementan (y, a veces, sustituyen) a los tradicionales métodos de prueba y error, debido al ahorro de tiempo y dinero en la fabricación de materiales y dispositivos. Interesa, por tanto, que los resultados de estas simulaciones sean muy fiables. Las simulaciones de primeros principios se realizan hoy día en base a la Teoría del Funcional de la Densidad (Density Functional Theory: DFT). Para alcanzar dicho objetivo, el trabajo fue dividido en una fase de investigación bibliográfica y una fase de aplicación. En la fase bibliográfica se estudió la teoría DFT, las características básicas de sus implementaciones (códigos de computación existentes), y sus logros y debilidades. Una de las principales dificultades de la teoría es describir bien (con buena aproximación) sistemas que contengan átomos de elementos de transición (con electrones nd). La fase de aplicación se realizó mediante el código SIESTA, que usa como datos de entrada pseudopotenciales (PS's) atómicos no locales y bases de orbitales atómicos numéricos (NAO's), y estuvo centrada en el estudio de la transferibilidad de dichos PS's y NAO's para los elementos V, Co, Rh, y Pd. Así, para cada uno de los elementos anteriores, se partió de PS's y NAO's previamente optimizados para reproducir propiedades experimentales de sistemas periódicos infinitos (bulks) como la energía de cohesión, o el módulo de compresibilidad, y se comprobó su capacidad para reproducir las propiedades típicas de los dímeros, tales como la energía de disociación, la distancia de enlace, la multiplicidad de espín y la frecuencia de vibración. En todos los casos se usó la aproximación de gradientes generalizados (GGA) de Perdew, Burke, y Ernzerhof (PBE) para el funcional de intercambio y correlación. El resultado final es un informe sobre los objetivos propuestos: adquirir los conocimientos necesarios para realizar simulaciones ab-initio mediante la Teoría del Funcional de la Densidad, llevar a cabo su implementación en el código SIESTA, y ser capaz de caracterizar pseudopotenciales no locales transferibles para aplicaciones que contengan elementos de transición con electrones 3d y 4d. Durante la realización de este trabajo, se han aplicado numerosos recursos y conocimientos adquiridos durante el Grado, siendo de mayor utilidad aquellos referidos a las asignaturas de Mecánica Cuántica, Física Atómica y Física del Estado Sólido.Grado en Físic

Self-consistent treatment of thermal effects in neutron-star post-mergers: observational implications for third-generation gravitational-wave detectors

We assess the impact of accurate, self-consistent modelling of thermal effects in neutron-star merger remnants in the context of third-generation gravitational-wave detectors. This is done through the usage, in Bayesian model selection experiments, of numerical-relativity simulations of binary neutron star (BNS) mergers modelled through: a) nuclear, finite-temperature (or ``tabulated'') equations of state (EoSs), and b) their simplifed piecewise (or ``hybrid'') representation. These cover four different EoSs, namely SLy4, DD2, HShen and LS220. Our analyses make direct use of the Newman-Penrose scalar $\psi_4$ outputted by numerical simulations. Considering a detector network formed by three Cosmic Explorers, we show that differences in the gravitational-wave emission predicted by the two models are detectable with a natural logarithmic Bayes Factor $\log{\cal{B}}\geq 5$ at average distances of $d_L \simeq 50$Mpc, reaching $d_L \simeq 100$Mpc for source inclinations $\iota \leq 0.8$, regardless of the EoS. This impact is most pronounced for the HShen EoS. For low inclinations, only the DD2 EoS prevents the detectability of such modelling differences at $d_L \simeq 150$Mpc. Our results suggest that the usage a self-consistent treatment of thermal effects is crucial for third-generation gravitational wave detectors.Comment: 9 pages, 3 Figure

Play therapy as a learning mediator for the integral development of children in the early childhood

En el presente artículo se abordará el principio de la lúdica como uno de los ejes centrales de la educación preescolar, siendo este principio fundamental para el aprendizaje y el desarrollo integral de los niños y niñas en la primera infancia. Para sustentar el mencionado principio, este artículo se basará en las experiencias significativas de la Práctica IV de intervención psico-social, adscrita a la Licenciatura en Educación Infantil de la Universidad Católica Luis Amigó, realizada en dos agencias de diferentes contextos sociales; por tal motivo se contrastan ambos contextos y se evidencia la implementación de la lúdica como mediador pedagógico en los entornos sociales y cómo esta puede afectar o favorecer el desarrollo y el aprendizaje de los niños y niñas.In this article, the principle of play will be addressed as one of the central axes of preschool education, this principle being fundamental for the learning and integral development of boys and girls in early childhood. To sustain the aforementioned article, it will base itself on the significant experiences of Practicum IV of psycho-social intervention, attached to the Degree in Early Childhood Education of the Universidad Católica Luis Amigó, carried out in two agencies from different social contexts, for which reason both are contrasted contexts and proves evident that the implementation of play as a pedagogical mediator in social settings, and how it can affect or favor the development and learning of children

Método a bajo costo para la cuantificación del grado alcohólico en muestras de tequila blanco

The green chemistry in the chemical analysis area consists of the design of qualitative or quantitative techniques that make a minimum generation of residues and have a validity in the results comparable to traditional methods. The microscale chemistry has had a relevant role in recent years in order to modify and implement new methodologies for the quantification of chemical analytes. In this project, a technique for quantifying the alcoholic content of tequila samples was developed based on the chemical principles of alcohol oxidation, which is a colorimetric technique that allows identifying the presence of an alcohol. The objective of the project was to apply the color change of the ethanol oxidation and to quantify it´s content based on the intensity of the blue color generated in the oxidation, using a low-cost photocolorimeter. The results were comparable with the obtained with a spectrophotometer, it was validated by a statistical method to know their reliability and finally, a correlation was made so that the same results were obtained with the proposed technique as with the commercial equipment.La química verde abordada en el área de los análisis químicos consiste en el diseño de técnicas cualitativas o cuantitativas que tengan una mínima generación de residuos y que permitan tener una validez en lo resultados comparable con métodos tradicionales. En este sentido, la química a microescala ha tenido un papel relevante en años recientes para poder modificar e implementar nuevas metodologías para la cuantificación de analitos químicos. En el presente proyecto se desarrolló una técnica de cuantificación del grado alcohólico de muestras de tequila basada en los principios químicos de la oxidación de alcoholes, la cual es una técnica colorimétrica que permite identificar la presencia de un alcohol. El objetivo del trabajo fue aprovechar el cambio de color de la oxidación del etanol y cuantificar el contenido alcohólico con base en la intensidad del color azul generado en la oxidación, mismo que se cuantificó con un fotocolorímetro a bajo costo y que mostró resultados comparables con los obtenidos con un espectrofotómetro, además que se realizó una validación estadística de los resultados para conocer la confiabilidad de los mismos y finalmente, se hizo una correlación para que con la técnica propuesta se obtuvieran los mismos resultados que con el equipo comercial

Low-latency gravitational wave alert products and their performance in anticipation of the fourth LIGO-Virgo-KAGRA observing run

Multi-messenger searches for binary neutron star (BNS) and neutron star-black hole (NSBH) mergers are currently one of the most exciting areas of astronomy. The search for joint electromagnetic and neutrino counterparts to gravitational wave (GW)s has resumed with Advanced LIGO (aLIGO)'s, Advanced Virgo (AdVirgo)'s and KAGRA's fourth observing run (O4). To support this effort, public semi-automated data products are sent in near real-time and include localization and source properties to guide complementary observations. Subsequent refinements, as and when available, are also relayed as updates. In preparation for O4, we have conducted a study using a simulated population of compact binaries and a Mock Data Challenge (MDC) in the form of a real-time replay to optimize and profile the software infrastructure and scientific deliverables. End-to-end performance was tested, including data ingestion, running online search pipelines, performing annotations, and issuing alerts to the astrophysics community. In this paper, we present an overview of the low-latency infrastructure as well as an overview of the performance of the data products to be released during O4 based on a MDC. We report on expected median latencies for the preliminary alert of full bandwidth searches (29.5 s) and for the creation of early warning triggers (-3.1 s), and show consistency and accuracy of released data products using the MDC. This paper provides a performance overview for LVK low-latency alert structure and data products using the MDC in anticipation of O4

Diseño de un sistema de control interno para las instituciones educativas de la provincia de Pichincha dirigidas por la Congregación de Hermanas Dominicas de la Inmaculada Concepción.

The job is base in activities that the Educational Units of the Province "Santo Domingo of Guzman” that consist of serving the society threw the comprehensive training and academic education, teaching evangelic values and morals that respond to the Dominican charism “Preach the truth and carry the light of Christ”. The educational unit of “Santo Domingo of Guzman” and “Saint Dominic School” are the base of our education since they have greater needs for implementation of controls and procedures, policies and strategies. They have been chosen for been the most representative of the educational province identifying weaknesses and threats through questionnaires that permits the determinations of the level of risk based on the mode COSO II threw the different components as: Control Environment, Objective Setting, Event Identification, Risk Assessment, Risk Response, Control Activities, Information and Communication, Monitoring and follow procedures, aim the controllers that will tame efficiently the activities in each and one of the departments and the areas that make up each entity.Este trabajo está basado en actividades que realizan las Unidades Educativas de la Provincia “Santo Domingo de Guzmán” que consiste en servir a la sociedad a través de la formación integral y educación académica, enseñando valores evangélicos y morales dando respuesta al carisma dominicano “PREDICAR LA VERDAD Y PORTAR LA LUZ DE CRISTO”. Las Unidades Educativas “Santo Domingo de Guzmán” y “Saint Dominic School” son base de nuestro estudio ya que poseen mayores necesidades de aplicación de controles y procedimientos, políticas y estrategias; se han elegido por ser más representativas de la Provincia identificando sus debilidades y amenazas por medio de cuestionarios que permiten determinar el nivel de riesgo basados en el modelo COSO II mediante los componentes: Ambiente de Control, Establecimiento de Objetivos, Identificación de eventos, Valoración del riesgo, Respuesta al riesgo, Actividades de control, Información y Comunicación, Monitoreo y hacer seguimientos, fijar controles que normen eficientemente las actividades en cada uno de los departamentos y áreas que conforman cada entidad

Realtime search for compact binary mergers in Advanced LIGO and Virgo's third observing run using PyCBC Live

The third observing run of Advanced LIGO and Advanced Virgo took place between April 2019 and March 2020 and resulted in dozens of gravitational-wave candidates, many of which are now published as confident detections. A crucial requirement of the third observing run has been the rapid identification and public reporting of compact binary mergers, which enabled massive followup observation campaigns with electromagnetic and neutrino observatories. PyCBC Live is a low-latency search for compact binary mergers based on frequency-domain matched filtering, which has been used during the second and third observing runs, together with other low-latency analyses, to generate these rapid alerts from the data acquired by LIGO and Virgo. This paper describes and evaluates the improvements made to PyCBC Live after the second observing run, which defined its operation and performance during the third observing run

Realtime search for compact binary mergers in Advanced LIGO and Virgo's third observing run using PyCBC Live

The third observing run of Advanced LIGO and Advanced Virgo took place between April 2019 and March 2020 and resulted in dozens of gravitational-wave candidates, many of which are now published as confident detections. A crucial requirement of the third observing run has been the rapid identification and public reporting of compact binary mergers, which enabled massive followup observation campaigns with electromagnetic and neutrino observatories. PyCBC Live is a low-latency search for compact binary mergers based on frequency-domain matched filtering, which has been used during the second and third observing runs, together with other low-latency analyses, to generate these rapid alerts from the data acquired by LIGO and Virgo. This paper describes and evaluates the improvements made to PyCBC Live after the second observing run, which defined its operation and performance during the third observing run

Clinical and cost outcomes of a polyethylene glycol (PEG)-coated patch versus drainage after axillary lymph node dissection in breast cancer: results from a multicentre randomized clinical trial

Background The aim of this study was to compare the clinical outcomes between breast cancer patients who underwent axillary lymph node dissection with postoperative management using a polyethylene glycol-coated patch versus axillary drainage. The direct costs associated with both postoperative management strategies were also evaluated. Methods This was a multicentre RCT in women with breast cancer who underwent axillary lymph node dissection (ClinicalTrials.gov identifier: NCT04487561). Patients were randomly assigned (1 : 1) to receive either drainage or a polyethylene glycol-coated patch as postoperative management. The primary endpoints were the need for an emergency department visit for any event related to the surgery and the rate of seroma development. Results A total of 227 patients were included , 115 in the patch group (50.7 per cent) and 112 (29.4 per cent ) in the drainage group. The incidence of emergency department visits was significantly greater for patients with drainage versus a polyethylene glycol-coated patch (incidence rate difference 26.1 per cent, 95 per cent c.i. 14.5 to 37.7 per cent; P < 0.001). Conversely, the seroma rate was significantly higher in the polyethylene glycol-coated patch group (incidence rate difference 22.8 per cent, 95 per cent c.i. 6.7 to 38.9 per cent; P < 0.0055). Compared with drainage, using a polyethylene glycol-coated patch resulted in cost savings of €100.41 per patient. An incremental cost-effectiveness ratio analysis found that drainage was associated with an incremental cost-effectiveness ratio of €7594.4 for no need for hospital admission and €491.7 for no need for an emergency department visit. Conclusion Compared with patients who received drainage after axillary lymph node dissection, the use of a polyethylene glycol-coated patch resulted in a higher rate of seroma, but a lower number of postoperative outpatient or emergency department visits and thus a reduction in overall costsFunding: This study was funded by a grant from the Spanish Association of Surgeons (grant number: not applicable). Acknowledgements: Medical writing and editorial assistant services were provided by Ciencia y Deporte S.L. Support for this assistance was funded by Baxter. Baxter was not involved in the preparation of the manuscript nor did the company influence in any way the scientific conclusions reache

Celebrating a face-to-face congress of young researchers in Optics after the pandemic years: the I NW MYRO

This contribution reports the organization and celebration after the Covid-19 pandemic of a singular scientific conference focused on early-career researchers from the Spanish universities of Santiago de Compostela and Salamanca: the “I Northwest Meeting of Young Researchers in Optics (I NW MYRO)”