Propuesta para el mejoramiento del tren de tratamiento de la planta de agua potable de la vereda Pajonales del municipio de Pacho Cundinamarca

Trabajo de InvestigaciónSe realizó el diagnostico de las estructuras hidráulicas presentes en el acueducto de la vereda Pajonales del municipio de Pacho Cundinamarca con el fin de verificar su funcionalidad según el Reglamento Técnico del Sector de Agua Potable y Saneamiento Básico – RAS 2000 y la resolución 0303 de 2017, de acuerdo a los datos obtenidos se procede a realizar el cálculo adecuado de las estructuras.INTRODUCCIÓN 1. GENERALIDADES 2. CARACTERIZACIÓN DEL FUNCIONAMIENTO 3. EVALUACIÓN DEL DESEMPEÑO 4. PROPONER LINEAMIENTOS DE MEJORA PARA EL TREN DE TRATAMIENTO. 5. RECOMENDACIONES Y TRABAJOS 6. CONCLUSIONES ANEXOSPregradoIngeniero Civi

Homocysteine treatment alters redox capacity of both endothelial and tumor cells

Homocysteine is a non-proteinogenic amino acid playing key roles in two interconnected metabolic pathways, namely, the activated methyl cycle and the linear trans-sulfuration pathway that allows the conversion of methionine to cysteine. A dysregulation of intracellular homocysteine metabolism could yield an increased export of this amino acid, leading to hyperhomocysteinemia, which has been associated with an increased risk of cardiovascular diseases. In spite of decades of experimental effort, there is no definitive consensus on what could be the molecular mechanisms whereby hyperhomocysteinemia could contribute to cardiovascular disease. The redox active nature of homocysteine has favored the idea of an induction of oxidative stress as the underlying mechanism of homocysteine toxicity. In contrast, homocysteine can also behave as an anti-oxidant. The present work is aimed to further analyze the capacity of homocysteine to modulate the redox capacity of both endothelial and tumor cells. [Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain)].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A High-Efficiency Isolated Wide Voltage Range DC-DC Converter Using WBG Devices

The recent release of the standard USB-PD 3.1 speci es variable output voltages from 5 V to 48 V featuring a step forward towards a universal adaptor but rising new challenges for the converter topologies used up to now. In such applications, a rst AC-DC stage is followed by a DC-DC stage. In this paper, emerging WBG technologies are applied to the asymmetrical half-bridge yback topology, demonstrating the potential of such combination as a wide voltage range DC-DC stage. Its suitability for high-density and high-ef ciency USB-PD Extended Power Range (EPR) and battery charger applications is discussed. The impact of different switching technologies, silicon and wide band gap, is analyzed. A general method to dimension the converter is presented and an iterative process is used to evaluate the theoretical ef ciency under different conditions and switching devices. Finally, the advantages of the presented converter using Gallium Nitride (GaN) devices are demonstrated in a 240 W DC-DC prototype. It achieves a full load ef ciency of 98%, and it is able to deliver an output voltage from 5 V to 48 V with input voltage range from 120 V to 420 V, as well an outstanding power density of 112 W/inch3 uncased.Infineon Technologies AG through the Spanish Regional Project P20_00265 BRNM-680-UGR20Spanish Ministry of Science MCIN/AEI PID2020-117344RB-I0

Resonant Hybrid Flyback, a New Topology for High Density Power Adaptors

In this article, an innovative power adaptor based on the asymmetrical pulse width modulation (PWM) flyback topology will be presented. Its benefits compared to other state-of-the-art topologies, such as the active clamp flyback, are analyzed in detail. It will also describe the control methods to achieve high efficiency and power density using zero-voltage switching (ZVS) and zero-current switching (ZCS) techniques over the full range of the input voltage and the output load, providing comprehensive guidelines for the practical design. Finally, we demonstrate the convenience of the proposed design methods with a 65 W adaptor prototype achieving a peak efficiency of close to 95% and a minimum efficiency of 93.4% at full load over the range of the input voltage, as well as a world-class power density of 22 W/inch3 cased.This research is financed by Infineon Tecnologias AG

Advanced control methods for Asymmetrical Half-bridge Flyback

—In this article, a power converter based on an asymmetrical half-bridge flyback topology is analyzed and optimized for small form factor and fast-charging power adaptors. Two resonant control methods, taking advantage of the forward and flyback characteristics of the converter, as well as the benefits of each of them depending of the operation point are discussed. The analysis is nourished with the equivalent circuits in each phase of operation and the equations that define them. Particularly innovative is the proposed zero voltage resonant valley switching control method for the mentioned converter; in this case, it is operated similarly to a flyback converter, allowing safe output voltage ramp up, which is one of the challenges that has limited the usage of this topology up to now. The manuscript also describes how to achieve high efficiency and power density using zero-voltage switching and zero-current switching techniques over the full range of the input voltage and the output load. Finally, the advantages of the proposed control methods are demonstrated in a 65-W adaptor prototype achieving a peak efficiency over 94.6% and an efficiency of 93.8% @ Vac ≥ 100 V at full load over the range of the input voltage, as well as a world-class power density of 35 W/in3 uncasedhis work was supported by Infineon Technologies AG by Contract OTRI 3770-05 and Contract OTRI 3770-0

Diseño conceptual y preliminar de un compresor centrífugo para un motor turbohélice

En el siguiente documento se presenta el proceso de diseño de un compresor centrifugo de una sola etapa para un motor turbo hélice, el cual se centró en encontrar los parámetros que ayudan a incrementar la eficiencia del motor sin alterar su número de etapas. Para esto, se definieron los parámetros que rigen el funcionamiento del compresor y las condiciones de diseño del mismo, con el fin de dimensionar el impulsor y difusor a partir de las teorías relacionadas con el diseño de compresores centrífugos, tomando como base de diseño el compresor centrifugo de un motor PT6A small. Conforme a las dimensiones obtenidas y las condiciones de salida del fluido se realizó un análisis teórico del desempeño del compresor, para determinar la eficiencia y relación de compresión global, con el fin de implementarlos en el análisis termogasodinámico el cual tiene como fin determinar el rendimiento del motor con el diseño del compresor propuesto y los valores expuestos por el fabricante, dando como resultado un rendimiento similar al de fábrica con tan solo un 2% de diferencia entre estos, logrando con esto identificar las ventajas y desventajas generadas a través de la implementación de este diseño. Posteriormente se realizó un análisis de esfuerzos en el impulsor a partir de la selección del material, con el fin de conocer la deformación en el impulsor, y por último se diseñó el compresor centrífugo en 3D con la ayuda del programa Solid Edge, a partir del dimensionamiento obtenido del compresor, en el cual se incluyeron los factores de diseño en el impulsor y difusor, dado a que producen una eficiencia general del 89%, con una relación de compresión de 3, sin necesidad de que sus demás componentes sufran cambios en sus dimensiones

Self-Referenced Multifrequency Phase-Resolved Luminescence Spectroscopy

Phase-resolved luminescence chemical sensors provide the analyte determination based on the estimation of the luminescence lifetime. The lifetime is estimated from an analysis of the amplitudes and/or phases of the excitation and emission signals at one or several modulation frequencies. This requires recording both the excitation signal (used to modulate the light source) and the emission signal (obtained from an optical transducer illuminated by the luminescent sensing phase). The excitation signal is conventionally used as reference, in order to obtain the modulation factor (the ratio between the emission and the excitation amplitudes) and/or the phase shift (the difference between the emission and the excitation phases) at each modulation frequency, which are used to estimate the luminescence lifetime. In this manuscript, we propose a new method providing the luminescence lifetimes (based either on amplitudes or phases) using only the emission signal (i.e., omitting the excitation signal in the procedure). We demonstrate that the luminescence lifetime can be derived from the emission signal when it contains at least two harmonics, because in this case the amplitude and phase of one of the harmonics can be used as reference. We present the theoretical formulation as well as an example of application to an oxygen measuring system. The proposed self-referenced lifetime estimation provides two practical advantages for luminescence chemical sensors. On one hand, it simplifies the instrument architecture, since only one analog-to-digital converter (for the emission signal) is necessary. On the other hand, the self-referenced estimation of the lifetime improves the robustness against degradation of the sensing phase or variations in the optical coupling, which reduces the recalibration requirements when the lifetimes are based on amplitudes.Spanish Ministry of Economy, Industry and Competitiveness CTQ2017-88079-P CTQ2014-53442-P BES-2009-026919Spanish Ministry of Economy, Industry and Competitiveness (Torres Quevedo Grants) PTQ-15-07922 PTQ-15-07912CEI BioTic Granada Campus CEIbioTIC14-201

Estudio de algunos casos de fisuración descendente en carreteras españolas

Tradicionalmente se ha admitido que la mayor parte de las fisuras que aparecen en la superficie del pavimento procede de las capas inferiores, afectadas por la fatiga o por la retracción que acompaña al fraguado de materiales tratados con cemento. Con dicho enfoque las fisuras superficiales no serían más que la evolución o el reflejo de un problema originado en las capas inferiores. Sin embargo, en la última década diversos trabajos de investigación han puesto de manifiesto la relevancia de otro problema muy diferente: la iniciación de fisuras en la capa de rodadura que progresivamente van afectando a las capas inferiores. Es lo que se ha denominado fisuración descendente (top-down cracking). En este artículo se muestran varios casos estudiados en carreteras españolas, en los que se ha constatado que las fisuras observadas en la superficie afectaban sólo a la capa de rodadura, aunque en algunos casos habían progresado, dañando ya la parte superior de la capa intermedia. Para caracterizar las mezclas asfálticas afectadas por este problema, más generalizado de lo que se creía hasta ahora, al menos en determinadas zonas climáticas, se extrajeron testigos, comprobando la granulometría de las mezclas, sus características mecánicas y el estado del ligante. Como resultado general puede concluirse que las mezclas afectadas tenían problemas de segregación granulométrica en vertical, y en todos los casos el ligante había envejecido sensiblemente, a pesar de tratarse de actuaciones algunas de ellas con sólo unos pocos años en servicio

Memcapacitor and Meminductor Circuit Emulators: A Review

This research was funded by the Japanese KAKENHI through Grant Number JP18k04275 and Spanish Ministry of Education, Culture, and Sport (MECD), through Project TEC2017-89955-P and Grant Numbers: FPU16/01451 and FPU16/04043.In 1971, Prof. L. Chua theoretically introduced a new circuit element, which exhibited a different behavior from that displayed by any of the three known passive elements: the resistor, the capacitor or the inductor. This element was called memristor, since its behavior corresponded to a resistor with memory. Four decades later, the concept of mem-elements was extended to the other two circuit elements by the definition of the constitutive equations of both memcapacitors and meminductors. Since then, the non-linear and non-volatile properties of these devices have attracted the interest of many researches trying to develop a wide range of applications. However, the lack of solid-state implementations of memcapacitors and meminductors make it necessary to rely on circuit emulators for the use and investigation of these elements in practical implementations. On this basis, this review gathers the current main alternatives presented in the literature for the emulation of both memcapacitors and meminductors. Different circuit emulators have been thoroughly analyzed and compared in detail, providing a wide range of approaches that could be considered for the implementation of these devices in future designs.Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (KAKENHI) JP18k04275Spanish Ministry of Education, Culture, and Sport (MECD) TEC2017-89955-P FPU16/01451 FPU16/0404

Digital resources and teaching approaches in preservice training of history teachers

Esta investigación ha sido posible gracias al proyecto de I+D de «Generación de conocimiento» PGC2018-094491-B-C33 financiado por el Ministerio de Ciencia e Innovación y cofinanciado con fondos FEDER de la Unión Europea, gracias al proyecto 20638/JLI/18 financiado por la Fundación Séneca, gracias al proyecto “HistoryLab for European Civic Engagement: open e-Toolkit to train History Teachers on Digital Teaching and Learning”, subvencionado por el SEPIE en la convocatoria ERASMUS + KA226 [2020-1-ES01-KA226-HE-095430], y gracias al proyecto de investigación PID2020- 113453RB-I00, subvencionado por la Agencia Estatal de Investigación de España (AEI/10.13039/501100011033)El presente trabajo se aborda teniendo en cuenta los estudios que demuestran la vinculación que realizan los docentes en formación con la función lúdica o motivacional concedida a las TIC y a los recursos digitales, así como a partir de las investigaciones que exponen la asociación existente entre el enfoque de enseñanza centrado en el docente (ITTF) con un aprendizaje superficial y el enfoque centrado en el alumnado (CCSF) con un aprendizaje profundo. Sobre este enunciado, se plantea como objetivo general analizar los enfoques de enseñanza del futuro profesorado de historia en España y su relación con sus opiniones sobre el uso de recursos digitales en un aula. Para ello, se utilizó un diseño cuantitativo no experimental, con una escala Likert, en el que participaron 646 estudiantes del Máster de Formación del Profesorado de la especialidad de Geografía e Historia de 22 universidades nacionales diferentes, es decir, el 70% de los centros de Educación Superior que ofertan dicha titulación en España. Como conclusión general, el análisis estadístico realizado con los datos correspondientes a los enfoques del futuro profesorado de historia en España y su relación con sus opiniones sobre el uso de recursos digitales en un aula permite inferir que la validación y la fiabilidad de la herramienta aplicada es muy positiva; que existe una débil vinculación de los recursos digitales con los procesos educativos y; por último, que se destaca una relación significativa entre la aplicación de un enfoque de enseñanza concreto y una visión particular acerca del uso de los recursos tecnológicos.The present research is approached taking into account the studies that demonstrate the connection that teachers in training make with the playful or motivational role granted to ICT and digital resources, as well as from the research shown by the association between a teacher-centred teaching approach (ITTF) with superficial learning and a student-centred approach (CCSF) with deep learning. Thus, the general objective of this research is to analyze the teaching approaches of future history teachers in Spain and their relationship with their opinions on the use of digital resources in a classroom. For this purpose, a non-experimental quantitative design with a Likert scale was used, in which 646 students of the Master’s Degree in Teacher Training in the specialty of Geography and History from 22 different national universities participated, that is, 70% of the universities offering this degree in Spain. As a general conclusion, the statistical analysis carried out with the data corresponding to the approaches of future history teachers in Spain and their relationship with their opinions on the use of digital resources in a classroom allows us to infer that the validation and reliability of the applied tool is very positive; that there is a weak link between digital resources and educational processes and; finally, a significant relationship between the application of a particular teaching approach and a particular view about the use of technological resources is highlighted.Ministerio de Ciencia e InnovaciónFEDERFundación SénecaSEPIEAgencia Estatal de Investigación de Españ