3,956 research outputs found
Classical dynamics of gas-surface scattering: fundamentals and applications.
144 p.This thesis manuscript is devoted to the theoretical study of several reactive andnon-reactive processes that take place at the gas-solid interface. Two classical trajec-tory methods, different and complementary, were used to simulate the dynamics ofthese processes. The first one relies on large sets of classical paths obtained by nu-merically solving Hamilton equations on a previously constructed potential energysurface (PES). Classical paths are then assigned statistical weights based on twosemiclassical corrections: Gaussian binning and the adiabaticity correction. Thisapproach, in a quantum spirit, was applied to the scattering of H2 on a Pd(111) sur-face. First, the study focused on collisions where H2 is initially in the rovibrationalground state. Then, rotationally excited states were considered. On this occasion,a variation of the adiabaticity correction based on firmer semiclassical grounds wasintroduced. In both cases, the predictions of the sticking and state-resolved reflec-tion probabilities were found to be in remarkably good agreement with those ob-tained through exact quantum time-dependent calculations, contrary to standardquasi-classical trajectory predictions. The classical approach in a quantum spiritcould thus be very useful for future studies.The second method used in this work, known as Ab-Initio Molecular Dynamics(AIMD), calculates the inter-nuclear forces from density functional theory and usesthem to classically move the nuclei. Contrary to the previous approach, AIMD doesnot require the very demanding construction of a PES. The price to pay, however,is that the numerical cost of each trajectory is much higher than with the previ-ous method. AIMD allowed us to study the dissociation process of H2 on W(110)surfaces. The functional we use includes a van der Waals term which provokesan increase of the far distance attraction that is compensated by a stronger repul-sion at short distances. The combination of both effects appreciably decreases thevalue of the dissociation probability, bringing it closer to the experimental resultwhen a clean surface is used. When oxygen atoms are previously adsorbed onthe surface, the dissociation probability drops considerably. This effect increaseswith the amount of oxygen on the surface. An ordered phase of O adsorbates onthe W surface is used to explain the nonexistent sticking probability for coverages¿ > 0.35 ML observed experimentally. We show that the oxygen atoms push the H2molecules away from the narrow bottlenecks that open the paths to dissociation inthe absence of oxygen atoms. This effectively eliminates any chance of dissociationin the surface for high coverages. At lower coverages, our calculations demonstratethat the dissociation dynamics resemble those in the clean surface just in very spe-cific surface regions
Self-Organization through a multi-agent system for orders distribution in large companies
This article presents the development of a multi-agent system in charge of self-managing a delivery system. The article focuses on the delivery management system and not on the movement systems of the different used vehicles./nThis system consists of different types of vehicles, each with different characteristics, and there may be several instances of each type of vehicle. There will be three operating agents (Drone Operator, Car Operator and Amphibious Operator), an agent that will be responsible for creating random tasks (used only in simulations) and another one that is responsible for distributing these tasks to the operators taking into account the algorithm. This algorithm follows the bases of backtracking and its main function is to assign a task to a vehicle taking into account the distance, the consumption, the limitations of weight and distances, etc. The whole system has been developed in JADE on java. The described software performs a complete simulation with a console in which it is indicated relevant information such as the tasks that are created, the type of vehicle and the instance of that type of vehicle that resolve the delivery, among others. The purpose of this system is to minimize costs and times
Series de Fourier diverxentes
Traballo Fin de Grao en Matemáticas. Curso 2021-2022O obxectivo deste traballo, recollido no propio título, é a demostración da existencia
de series de Fourier diverxentes. O documento estrutúrase en tres partes diferenciadas. A
primeira na que se realiza un achegamento á teoría básica de series de Fourier, incluíndo
definicións e resultados sobre converxencia das mesmas, e na que tamén se construirá unha
función continua con serie diverxente. O segundo capítulo dedicarase ao desenvolvemento
de conceptos e propiedades propias da Análise Funcional que nos permitirán demostrar o
Principio de Limitación Uniforme. No terceiro capítulo realizarase unha demostración non
constructiva da existencia de ditas series.The objective of this essay, as indicated in the title, is to prove the existence of divergent
Fourier series. The document is structured in three differentiated parts. In the first part,
the basis of Fourier series theory is introduced, including definitions, results and their
convergence, as well as the construction of a continuous function for which the Fourier series
diverges. The second chapter is dedicated to the development of concepts and properties
of Functional Analysis that will act as proof for the Uniform Boundedness Principle. Last,
in the third chapter, a non-constructive proof for the existence of such series is performed
Traducción audiovisual: Análisis de la traducción de nombres propios en la serie (Des)encanto (Groening, 2018–)
Actualmente, vivimos en un mundo cada vez más globalizado, con un constante intercambio cultural. Dentro del ámbito audiovisual, gran difusor de cultura, una herramienta muy importante en este intercambio es internet y, más concretamente, las plataformas en línea de vídeo bajo demanda que han aparecido en las últimas décadas como Netflix o HBO. Gracias a esto, disponemos en la actualidad de un número cada vez mayor de productos audiovisuales cuyos textos se traducen a lenguas distintas para acercarlos al mayor número de culturas posible. Por ello, creemos que es conveniente analizar los problemas de índole cultural que puedan surgir a la hora de traducir dichos textos audiovisuales. Uno de los elementos que puede ocasionar ese tipo de problemas es la traducción de los nombres propios. Para este análisis concreto, hemos elegido la serie (Des)encanto (Groening, 2018– ), una comedia animada de género fantástico, como objeto de estudio. En dicho análisis, identificaremos todos los nombres propios presentes en las versiones original y traducida del texto para luego clasificar las estrategias de traducción que se han usado, determinando así el grado de adaptación cultural que han sufrido los nombres propios durante su traducción.Grado en Traducción e Interpretació
Fractionation of spent sulphite liquor into monomeric sugars and lignosulphonates by an ultrafiltration series system
Spent sulphite liquor (SSL) is the main byproduct of acid sulphite pulping. Its main components are lignosulphonates (LS) and monomeric sugars. SSL is typically intended as binder, emulsifier or additive in concretes due to its high amount of LS. Sugars can be converted into high value-added products such as xylitol, PHB or biofuels among others; by means of fermentation processes. However, a separation step to remove the compounds that can act as fermentation inhibitors, as LS, is needed.
Membrane technology allows the separation of sugars and LS from the SSL because of their different size of molecular weight. In the present study, ceramic membranes with different cut-offs (15 kDa, 5 kDa and 1 kDa) were used. 15 kDa membrane offered the best results according to LS concentration in the retentate stream, 5 kDa membrane the highest LS removal in permeate stream, and 1 kDa membrane the minimum sugar losses in the permeate stream. Because of this, the combination of the three membranes in a series system was proposed. In this way, an increase in LS removal in the final permeate was achieved (72.78 %), but also an increase in the sugar losses (26.80 %). Hence, further studies will determine the optimal configuration system of this process.Authors would like to thank the Department of Education, Universities and Investigation of the Basque Government (Postdoctoral Development Program and project IT672-13) and the Spanish Ministry of Economy and Competitiveness (CTQ2013-41246-R) for financially supporting this work
La singularidad de La Palma en la Guerra Civil
La Guerra Civil fue un conflicto bélico que se desarrolló en España, desde el 18 de julio de 1936 hasta el 1 de abril de 1939. En Canarias no tuvieron lugar batallas, pero sí una importante represión en contra de dirigentes y simpatizantes del Gobierno del Frente Popular. Las singularidades que presentamos en el trabajo, ocurren en la isla de La Palma. En primer lugar, cómo fue la única Isla que se mantuvo fiel a la II República durante siete días, retrasando las consecuencias del golpe de Estado, y dando lugar al periodo conocido como la Semana Roja. En Segundo lugar, el fenómeno de los “Alzados”, personas que habían tenido relación con dicha Semana Roja, bien siendo dirigentes o parte de las milicias populares que se crearon, y que con la llegada de tropas sublevadas, tuvieron que huir y esconderse en los montes para huir de la represión
Lycopene Supplementation for Patients Under Cancer Therapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Introduction: Lycopene supplementation has been considered potentially useful as an adjuvant cancer therapy according to its anticancer properties. The present study aimed to investigate the effects of lycopene supplementation on outcome improvement in patients with cancer therapy. As a secondary aim, we conducted a meta analysis to investigate the efficacy of lycopene supplementation on circulating lycopene concentration in patients with cancer therapy.Methods: A systematic and comprehensive search was performed in electronic databases, including PubMed, Cochrane Central Register of Controlled Trials, Web of Science, SCOPUS, EMBASE, MedNar, and OpenGrey up to March 2023. The inclusion criteria were randomized controlled trials conducted on patients under cancer therapy (i.e., radiotherapy, chemotherapy, surgery, etc.) supplementing with lycopene. Data extraction and analysis: two different evaluators screened and collected literature independently. Information regarding the study design, participants, intervention, and dependent outcomes was extracted, and the bias of the study was assessed. Additionally, separate random-effect meta-analyses were performed to examine the effects of lycopene supplementation on circulating lycopene concentration in patients under cancer therapy.Results: The initial search retrieved 7 565 articles of which eight met the inclusion criteria. Lycopene supplementation did not modify cancer hallmarks in these studies. However, despite the heterogeneity between studies, we show that, compared with control, lycopene supplementation had moderate effects on circulating lycopene concentration in patients under cancer therapy (pooled mean difference, 0.1361; 95% CI [0.0574; 0.2148], P = .0007).Conclusions: Our study shows that lycopene supplementation does not modify the main hallmarks of cancer, but it increases circulating lycopene concentration in patients under cancer therapy, which could have a positive impact on potential clinical and molecular outcomes in cancer patients.Spanish Government
FPU19/01609University of Granada Plan Propio de Investigacion 2016-Excellence actions: Unit of Excellence on Exercise and Healt
Aplicación Práctica de Métodos para Evaluar In-Situ el Rendimiento Instantáneo de Máquinas Frigoríficas de Compresión Mecánica
Libro de actas completo disponible en :http://repositorio.bib.upct.es:8080/dspace/handle/10317/4709Los equipos de aire acondicionado, bombas de calor y refrigeración suponen un elevado consumo de energía eléctrica en los países industrializados. Es frecuente que, en la práctica, estos equipos no estén operando con la eficiencia que debieran. De ahí la importancia de realizar inspecciones periódicas, que incluyan mediciones de los diferentes parámetros de operación de los equipos, destacando por su importancia la medición de su rendimiento (EER/COP). La medición precisa in-situ del EER/COP sobre una instalación frigorífica de compresión mecánica, fuera de un banco de ensayo de laboratorio, ha sido desde siempre una cuestión muy complicada, con muchas dificultades prácticas. Un punto crítico es la medición del caudal de fluido refrigerante. Si no se dispone de un caudalímetro instalado, que es la situación más habitual, hay que recurrir a mediciones indirectas. Hay varios métodos indirectos para estimar el caudal de refrigerante, que se pueden clasificar en los que se basan en: a) el rendimiento volumétrico del compresor, b) el rendimiento global del compresor, c) un balance de energía sobre el condensador y d) un balance de energía sobre el compresor. En este trabajo se ponen en práctica y analizan estos cuatro métodos sobre instalaciones frigoríficas existentes en el laboratorio docente del Departamento de Máquinas y Motores Térmicos de la Universidad de Málaga [1]. Para ello se utiliza un sistema de medición de bajo coste, basado en sensores ONSET [2]. El procesado y análisis de los datos se hace mediante el software Engineering Equation Solver [3]. Se discuten los resultados y dificultades encontradas en la aplicación de los diferentes métodos y se ofrecen recomendaciones a tener en cuenta para abordar instalaciones más complejas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Ab Initio Molecular Dynamics of Hydrogen on Tungsten Surfaces
The dissociation process of hydrogen molecules on W(110) was studied using density functional theory and classical molecular dynamics. We have calculated the dissociation probability for molecules with energies below 300 meV and analyzed the dynamics of the adsorption process. Our results show that the fate of each trajectory is determined at distances relatively far from the surface, at roughly 2-2.5 angstrom. This distance varies slightly with the initial kinetic energy of the molecule. Part of our simulations include van der Waals dispersion effects in the interaction between molecule and surface. We present a comparison between these results and other theoretical and experimental results previously published. The inclusion of the van der Waals term provokes an increase in the far-distance attraction that is compensated by a stronger repulsion at short distances. The combination of both effects appreciably decreases the value of the dissociation probability. The successful comparison of our results with experimental information confirms that the methodology employed can be considered as a rich and accurate instrument to study the dissociation of hydrogen on surfaces.A. R. F. acknowledges financial support by the University of Bordeaux. This work was conducted in the scope of the transborder joint Laboratory “QuantumChemPhys: Theoretical Chemistry and Physics at the Quantum Scale” (ANR-10-IDEX-03-02). This work has been supported in part by the Basque Departamento de Educación, Universidades e Investigación, the University of the Basque Country UPV/EHU (Grant No. IT1246-19) and the Spanish Ministerio de Ciencia e Innovación (PID2019-107396GB-I00/AEI/10.13039/501100011033)
PCR altamente sensible para la detección de Leptospira spp. patógenas en tejidos embebidos en parafina
This study describes the development and application of a new PCR assay for the specific detection of pathogenic leptospires and its comparison with a previously reported PCR protocol. New primers were designed for PCR optimization and evaluation in artificially-infected paraffin-embedded tissues. PCR was then applied to post-mortem, paraffin-embedded samples, followed by amplicon sequencing. The PCR was more efficient than the reported protocol, allowing the amplification of expected DNA fragment from the artificially infected samples and from 44% of the post-mortem samples. The sequences of PCR amplicons from different patients showed >;99% homology with pathogenic leptospires DNA sequences. The applicability of a highly sensitive and specific tool to screen histological specimens for the detection of pathogenic Leptospira spp. would facilitate a better assessment of the prevalence and epidemiology of leptospirosis, which constitutes a health problem in many countries.El presente estudio describe el desarrollo y aplicación de un nuevo ensayo de PCR para la detección específica de leptospiras patógenas y su comparación con un protocolo reportado previamente. Se diseñaron nuevos cebadores para la optimización y evaluación de la PCR en tejidos embebidos en parafina infectados artificialmente. La PCR se aplicó además a muestras de tejidos embebidos en parafina y se realizó la secuenciación del amplicón resultante. La PCR diseñada fue más eficiente que el protocolo reportado, permitiendo la amplificación del fragmento de ADN esperado en las muestras infectadas artificialmente y del 44% de las muestras post mortem. Se secuenciaron 10 amplicones provenientes de pacientes diferentes. La aplicabilidad de una herramienta altamente sensible y específica en la búsqueda de leptospiras patógenas en especímenes histopatológicos podría facilitar una mejor valoración de la prevalencia y la epidemiología de la leptospirosis, la que constituye un problema de salud en disímiles países
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