Análisis y descripción del impacto de la moto eléctrica en el sistema de distribución

En este trabajo se desarrolló el impacto de la motocicleta eléctrica en la red de distribución, donde se propuso y se desarrolló un dispositivo de medición basado en la toma de datos en tiempo real con la ayuda de una tarjeta de adquisición de datos, posteriormente mediante la segunda ley de newton se logra establecer el modelo de la motocicleta eléctrica en función de diferentes variables como lo son el peso, la fuerza de rodadura, la fuerza aerodinámica, la fuerza motriz y por último la fuerza gravitacional con sus respectivas componentes, este modelo se implementó tanto para la subida como para la bajada, así mismo se registró la cantidad y los diferentes recorridos de las motos de combustión interna que se dirigen hacia la universidad tecnológica de Pereira, los datos recolectados mediante encuesta virtual y presencial se emplearon para establecer mediante las matrices de origen destino la potencia consumida por la moto eléctrica en diferentes recorridos para proponer y validar los beneficios del cambio de las motos de combustión interna por motos eléctricas en los usuarios de la Universidad Tecnología que aceptarían dicho cambio, finalmente verificando los resultados obtenidos se concluye con el objetivo principal del impacto de la motocicleta en la red de distribución

Vortex solutions of the Lifshitz-Chern-Simons theory

We study vortex-like solutions to the Lifshitz-Chern-Simons theory. We find that such solutions exists and have a logarithmically divergent energy, which suggests that a Kostelitz-Thouless transition may occur, in which voxtex-antivortex pairs are created above a critical temperature. Following a suggestion made by Callan and Wilzcek for the global U(1) scalar field model, we study vortex solutions of the Lifshitz-Chern-Simons model formulated on the hyperbolic plane, finding that, as expected, the resulting configurations have finite energy. For completeness, we also explore Lifshitz-Chern-Simons vortex solutions on the sphere.Comment: Published version, added appendix on electromagnetic duality in Lifshitz system

The be and live together competencies for social commitment in the biology career

La formación humanística para el desarrollo de competencias del ser y el convivir aparece como un aspecto importante a tener en cuenta en el desarrollo de currículos de diferentes carreras, desde la aparición del concepto de competencia para la educación superior en la cumbre de Bolonia, y su posterior contextualización por parte del proyecto Tuning. En el caso de Colombia se ha resaltado la necesidad de promover la formación basada en competencias de profesionales de diversas áreas del conocimiento, como lo muestran distintos estudios realizados por algunas universidades, así como por parte del ministerio de educación. Sin embargo, la formación basada en competencias representada en los planes de estudio de la Carrera de Biología en Colombia, no parece prestar la atención suficiente al desarrollo de una formación humanística que promueva el desarrollo de competencias del ser y el convivir. El presente ensayo constituye una revisión documental descriptiva y comparativa, con el propósito de aportar elementos que contribuyan en la solución del problema relacionado con la ausencia de compromiso y responsabilidad social de los egresados de la Carrera de Biología. Para tal efecto se realizó un estudio comparativo de las competencias propias del perfil del egresado en seis universidades colombianas (Universidad de Antioquia, Universidad Nacional, Universidad Militar Nueva Granada, Universidad del Valle, Universidad de los Andes y Universidad de Quindío). Los resultados permiten establecer que de los programas de Biología analizados en este ensayo, el ofrecido por la Universidad del Quindío es el que mayor contenido humanístico presenta en su currículo y su perfil de egreso, contrario a las Universidades Nacional y de los Andes, quienes presentaron el menor contenido humanístico según este estudio.The humanistic formation for the development of the "be" and "live together" competences appears like an important aspect to be taken into account in the development of curricula of different careers, from the appearance of the concept of competence for the higher education in the summit of Bologna, and its Later contextualization by the Tuning Project. In the case of Colombia, the need to promote competency-based formation of professionals in different fields of knowledge has been highlighted, as shown by different studies carried out by some universities, as well as by the Colombian Ministry of Education. However, the competency-based formation represented in the Biology curricula in Colombia, does not seem to pay enough attention to the development of a humanistic formation that promotes the development of "be" and "live together" competences. The present essay constitutes a descriptive and comparative documentary revision, with the purpose of offering elements that contribute to the solution of the problem related to the absence of commitment and social responsibility of the graduated ones from the Biology programs. For that purpose, a comparative study of the proficiencies of the graduate profile in six Colombian universities (Universidad de Antioquia, Universidad Nacional, Universidad Militar de Nueva Granada, Universidad del Valle, Universidad de los Andes y Universidad de Quindío) was carried out. The results allow to establish that, of the biology programs analyzed in this essay, the one offered by the Universidad de Quindío is the one that presents the highest humanistic content in its curriculum and its graduate profile, in the opposite way to “Nacional” and “de los Andes” Universities, who presented the lowest humanistic content according to this study

A detour in the Road to Totalitarianism:: An extended review of the book “Causas y causantes del desastre económico en Venezuela. Un homenaje a Hugo J. Faría”

An extended review of the book “Causas y causantes del desastre económico en Venezuela. Un homenaje a Hugo J. Faría” (Causes and agents of the economic disaster in Venezuela. A tribute to Hugo J. Faría

Developing and Testing of an Upper Limb Exoskeleton for Stroke Patients

Objective: The main objective of this study was to determine functional and neuromuscular outcomes of stroke patients using their non-preferred hand with and without a 3D printed passive exoskeleton compared to controls using their non-preferred hand with and without the passive exoskeleton. Methods: Adults at least six months post stroke (Stroke, n = 5) and age- and sex- matched healthy controls (Control, n = 5) performed nine trials of a gross motor task while having their brain activity measured. The Fugl-Meyer and “Box and Block” test was used to measure the gross dexterity of the subjects with and without the exoskeleton. Strength testing, muscle activation and co-activation of the subjects’ forearms were measured during maximal voluntary contractions. Furthermore, EMG was measured during the Box and Block test and satisfaction and usability of the 3D printed exoskeleton were assessed using standardized questionnaires. Results: Separate two-way repeated ANOVAs were used to investigate the functional and neuromuscular outcomes. There was an interaction [F(1,4) = 41.60; p = .003, ηp2 = 0.912] with an observed power of 0.996. Decomposing the model, a dependent t-test (p = 0.004) showed the stroke subject’s preferred hand moved more blocks than the stroke subject’s non- preferred hand. The exoskeleton received an average QUEST score of 4.23 out of a maximum score of 5 and SUS score of 79.50 out of 100. Conclusion: The main finding showed the passive exoskeleton did not improve function or neuromuscular outcomes for the stroke patients

Study of Structural, Thermic, μ-Raman and Optic Transformation of PVA/TiO2 Polymeric Membranes

Composites (1-x)PVA/xTiO2 (0,025≤x≤0,250) were prepared from aqueous solution. The influence of TiO2 ceramic fillers on polymer matrix was characterized by: X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), micro-Raman scattering, UV-visible absorption (UV-vis) and scanning electronic microscopy (SEM). Raman and XRD results showed the amorphous and monoclinic phases for PVA and anatase phase for TiO2. SEM micrographs showed spread TiO2 fillers in PVA polymeric matrix forming aggregates. DSC and TGA thermograms show phase transitions with temperature, glass transition temperature (Tg) and thermal stability of polymeric matrix. The band gap energy (Eg) related to TiO2 (anatase) has been calculated from UV-visible measures, showing a strong absorption at near-UV region due to ceramic fillers.Se sinterizaron membranas compuestas (1–x)PVA/xTiO2 (0,025≤x≤0,250) por mezclas en disolución acuosa.La influencia de los rellenos cerámicos de TiO2 sobre la matriz polimérica de PVA se estudió por espectroscopía μ–Raman, difracción de rayos–X (XRD), calorimetría diferencial de barrido (DSC), análisis termo–gravimétrico (TGA), absorción UV–visible y microscopía de barrido electrónico (SEM). Resultados Raman y XRD mostraron las fases amorfa y monoclínica para el PVA y la fase anatasa para el TiO2. Micrografías SEM mostraron los rellenos de TiO2 dispersos en la matriz polimérica de PVA formando agregados. Resultados DSC y TGA mostraron transiciones de fase con la temperatura, la temperatura detransición vítrea (Tg) y la estabilidad térmica de la matriz polimérica. La energía de band gap óptico (Eg) relacionada con el TiO2 (anatasa) se calculó de medidas UV–visible, mostrándose una fuerte absorción en la región UV–cercana debido a los rellenos cerámicos

Scanning tunneling microscopy on low dimensional systems: dinickel molecular complexes and iron nanostructures

This thesis contains experimental studies on low dimensional systems by means of scanning tunneling microscopy (STM). These studies include investigations on dinickel molecular complexes and experiments on iron nanostructures used for the implementation of the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. Additionally, this work provides detailed information of the experimental technique (STM), from the theoretical background to the STM-construction, which was part of this doctoral work. Molecular anchoring and electronic properties of macrocyclic magnetic complexes on gold surfaces have been investigated by mainly scanning tunneling microscopy and complemented by X-rays photoelectron spectroscopy. Exchange–coupled macrocyclic complexes [Ni2L(Hmba)]+ were deposited via 4-mercaptobenzoate ligands on the surface of Au(111) single crystals. The results showed the success of gold surface-grafted magnetic macrocyclic complexes forming large monolayers. Based on the experimental data, a growth model containing two ionic granular structures was proposed. Spectroscopy measurements suggest a higher gap on the cationic structures than on the anionic ones. Furthermore, the film stability was probed by the STM tip with long-term measurements. This investigation contributes to a new promising direction in the anchoring of molecular magnets to metallic surfaces. Iron nanostructures of two atomic layers and iron-coated tungsten tips were used in order to implement the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. First of all, a systematic study of the iron growth, from sub-monolayers to multilayers on a W(110) crystal is presented. Subsequent to the well-understanding of the iron growth, the experiments were focused on revealing, for the first time at the IFW-Dresden, the magnetic inner structure of iron nanostructures. The results evidently showed the presence of magnetic domains of irregular shapes. Furthermore, SP-STM probed the bias voltage dependence of the magnetic contrast on the iron nanostructures. This technique opens up a new powerful research line at the IFW-Dresden which is promising for the study of quantum materials as molecular magnets and strongly correlated systems

Study of Structural, Thermic, μ-Raman and Optic Transformation of PVA/TiO2 Polymeric Membranes

Composites (1-x)PVA/xTiO2 (0,025≤x≤0,250) were prepared from aqueous solution. The influence of TiO2 ceramic fillers on polymer matrix was characterized by: X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), micro-Raman scattering, UV-visible absorption (UV-vis) and scanning electronic microscopy (SEM). Raman and XRD results showed the amorphous and monoclinic phases for PVA and anatase phase for TiO2. SEM micrographs showed spread TiO2 fillers in PVA polymeric matrix forming aggregates. DSC and TGA thermograms show phase transitions with temperature, glass transition temperature (Tg) and thermal stability of polymeric matrix. The band gap energy (Eg) related to TiO2 (anatase) has been calculated from UV-visible measures, showing a strong absorption at near-UV region due to ceramic fillers.Se sinterizaron membranas compuestas (1–x)PVA/xTiO2 (0,025≤x≤0,250) por mezclas en disolución acuosa.La influencia de los rellenos cerámicos de TiO2 sobre la matriz polimérica de PVA se estudió por espectroscopía μ–Raman, difracción de rayos–X (XRD), calorimetría diferencial de barrido (DSC), análisis termo–gravimétrico (TGA), absorción UV–visible y microscopía de barrido electrónico (SEM). Resultados Raman y XRD mostraron las fases amorfa y monoclínica para el PVA y la fase anatasa para el TiO2. Micrografías SEM mostraron los rellenos de TiO2 dispersos en la matriz polimérica de PVA formando agregados. Resultados DSC y TGA mostraron transiciones de fase con la temperatura, la temperatura detransición vítrea (Tg) y la estabilidad térmica de la matriz polimérica. La energía de band gap óptico (Eg) relacionada con el TiO2 (anatasa) se calculó de medidas UV–visible, mostrándose una fuerte absorción en la región UV–cercana debido a los rellenos cerámicos