196 research outputs found
Análisis de la red social de investigadores sobre RSC
Universidad de Sevilla. Grado en Finanzas y Contabilida
From Quantum Probabilities to Quantum Amplitudes
The task of reconstructing the system’s state from the measurements results, known as the Pauli problem, usually requires repetition of two successive steps. Preparation in an initial state to be determined is followed by an accurate measurement of one of the several chosen operators in order to provide the necessary “Pauli data”. We consider a similar yet more general problem of recovering Feynman’s transition (path) amplitudes from the results of at least three consecutive measurements. The three-step histories of a pre- and post-selected quantum system are subjected to a type of interference not available to their two-step counterparts. We show that this interference can be exploited, and if the intermediate measurement is “fuzzy”, the path amplitudes can be successfully recovered. The simplest case of a two-level system is analysed in detail. The “weak measurement” limit and the usefulness of the path amplitudes are also discussed.Financial support of MCIU, through the grant PGC2018-101355-B-100(MCIU/AEI/FEDER, UE) (SMG, MP, DS), of Spanish MINECO, project FIS2016-80681-P (MP), and of the Basque Government Grant No IT986-16 (SMG, MP, DS) is gratefully acknowledged
Diseño e implementación de un sistema automático de suministro trifásico permanente y optimización del consumo energético para la Avícola “Flor María”.
En la Avícola “Flor María” se diseñó e implementó un sistema de transferencia automático para el sumistro eléctrico trifásico permanente, en el consumo energético proveniente de la red pública, Empresa Eléctrica Riobamba (EERSA). Se utilizó un tablero de transferencia automática comandado por un controlador lovato ATL 610 que garantizó el suministro eléctrico de la EERSA o del Generador (MODASA MP- 1 10), un controlador lovato DCRL 8 que corrigió el bajo factor de potencia presente en la red, debido a la alta carga variable e inductiva y una pantalla HMI que monitorea la generación de energía en horas pico sobre los 50 kw. Como resultado se obtuvo un factor de potencia de 0.98, tiempo de respuesta de 5 segundos, reducción de consumo de potencias activa 18.80%, potencia aparente 23.81%, potencia reactiva 53.21%. La implementación mejoró el factor de potencia en diferentes consumos, permitió la generación de energía eléctrica en horas pico y redujo los costos de consumo energético anual a un 20.26 %, un ahorro energético anual del 7.13% y una disminución del consumo anual de diésel en un 80 %. La realización de los mantenimientos pertinentes en el sistema autónomo, permitió el correcto balance de cargas dando un funcionamiento ideal, erradicando posibles fallos.In the "Flor María" Avicola, an automatic transfer system for permanent three-phase electricity supply was designed and implemented, in energy consumption from the public network. Empresa E1éctrica Riobamba (EERSA). An automatic transfer board commanded by a Lovato ATL 610 controller was used that guaranteed the power supply of the EERSA or the Generator (MODASA MP- 110), a Lovato DCRL 8 controller that corrected the low power factor present in the network, due to the high variable and inductive load, and an HMI screen that monitored the generation of energy in peak hours over 50 kw. As a result, a power factor of 0.98, response time of 5 seconds, reduction of active power consumption 18.80%, apparent power 23.81%, reactive power 53.21 % was obtained. The implementation improved the power factor in different consumptions, allowed the generation of electricity during peak hours and reduced annual energy consumption costs to 20.26%, an annual energy saving of 7.13% and a decrease in annual diesel consumption by 80% The realization of the relevant maintenance in the autonomous system, allowed the correct balance of loads giving an ideal operation, eradicating possible failures
Speed-up and slow-down of a quantum particle
[EN] We study non-relativistic propagation of Gaussian wave packets in one-dimensional Eckart potential, a barrier, or a well. In the picture used, the transmitted wave packet results from interference between the copies of the freely propagating state with different spatial shifts (delays), x′, induced by the scattering potential. The Uncertainty Principle precludes relating the particle’s final position to the delay experienced in the potential, except in the classical limit. Beyond this limit, even defining an effective range of the delay is shown to be an impracticable task, owing to the oscillatory nature of the corresponding amplitude distribution. Our examples include the classically allowed case, semiclassical tunnelling, delays induced in the presence of a virtual state, and scattering by a low barrier. The properties of the amplitude distribution of the delays, and its pole representation are studied in detail.Financial support through the grants PGC2018-101355-B-100 funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”, PID2019-107609GB-I00 by MCIN, and the Basque Government Grant No IT986-16, is acknowledged by MP and DS
Klein paradox for bosons, wave packets and negative tunnelling times
We analyse a little known aspect of the Klein paradox. A Klein-Gordon boson appears to be able to cross a supercritical rectangular barrier without being reflected, while spending there a negative amount of time. The transmission mechanism is demonstrably acausal, yet an attempt to construct the corresponding causal solution of the Klein-Gordon equation fails. We relate the causal solution to a divergent multiple-reflections series, and show that the problem is remedied for a smooth barrier, where pair production at the energy equal to a half of the barrier's height is enhanced yet remains finite.Financial support of MCIU, through the Grant PGC2018-101355-B-100(MCIU/AEI/FEDER,UE) (XGdC, MP, DS), of Spanish MINECO, project FIS2016-80681-P (MP), and of the Basque Government Grant no. IT986-16 (MP, DS) is gratefully acknowledged
Diseño e implementación de un prototipo con HMI para automatizar procesos de cultivo hidropónico de lechuga
El diseño e implementación de un prototipo con HMI (Interfaz hombre-máquina) para automatizar procesos de cultivo hidropónico de lechuga implementado en el invernadero de la Facultad de Recursos Naturales de la Escuela Superior Politécnica de Chimborazo. Utilización del método de investigación experimental, aplicando la técnica raíz flotante para cultivos hidropónicos, se desarrolló un sistema con tubería plástica, bomba, tanque basados en parámetros como: volumen, caudal, presión y altura de trabajo de entrada y salida del sistema, controlado por dos sistemas independientes de cultivos con electroválvulas. Se monitorea y controla parámetros como son: temperatura, humedad, circulación del sustrato a través de un logo con su respectiva interfaz hombre-máquina diseñado en la plataforma de LOGO! Soft V7.0. Los resultados obtenidos determinaron que el prototipo implementado ofrece un aumento de producción del 85.71% por metro cuadrado, es decir normalmente se cultivan 7 plantas por metro cuadrado, mientras que con el prototipo se produce 13 plantas con ahorro de agua del 72.73 % e incremento anual de producción de 3 a 5 cosechas. Como conclusión, el prototipo implementado y su producto obtuvo mayor densidad de plantas por metro cuadrado con aumento de producción anual, además disminución de agroquímicos por ausencia de malezas siendo un producto saludable con tasas nutricionales uniformes.Se recomienda al responsable del sistema conocimientos y un estricto control respecto a su funcionamiento y equilibrio nutricional durante el ciclo de producción porque repentinos cambios de temperatura y ventilación tendrán respuesta directa e inmediata en el cultivo, sobre todo en ambientes protegidos
Size-dependent filling effect of crystalline celluloses in structural engineering of composite oleogels
Oleogels are a class of solid-fat mimetics that contain a large fraction of oil. Most of these materials have low stiffness and poor oil-binding capacity at commercially viable concentrations, which limits their application in the food and cosmetic industries. To improve their mechanical behavior, we exploited the concepts of particulate-filled materials by developing oil-continuous monoglyceride composites reinforced with crystalline cellulose of various sizes. Cellulose was used as the reinforcing filler material due to its strength, biodegradability, and abundance. The composites gradually stiffened and became more brittle with a progressive increase of the cellulose weight fraction as the maximum packing fraction of fillers approached. This was manifested as an increase in the viscoelastic moduli and yield stress, consistent with the size of the filler. Based on differential scanning calorimetry, X-ray diffraction, X-ray scattering analyses, and microscopic analyses, the inert surface of crystalline celluloses provided a solid substrate for the crystallization of monoglycerides, favoring the lamellar stacking of monoglyceride molecules during the composite oleogel formation regardless of the cellulose size. The present study suggests that cellulose is a suitable bio-based filler material to obtain mechanically strong oleogels suitable for high-shear applications e.g., in food and pharmaceutical industries.Peer reviewe
Crystallographic MAD Phasing Strategies Explored Using ELETTRA Sincrotrone Mn K-Edge Data to 2.1 Å and Use of CHESS Establishes the Diffraction Resolution Limit as 0.92 Å for the Protein Mn, Ca Concanavalin A
Multiwavelength anomalous dispersion (MAD) data have been collected from a single crystal of the protein concanavalin A so as to evaluate different combinations of wavelengths for crystallographic structure determination. Data were recorded to 2.1 Å resolution on a flash frozen crystal at three wavelengths about the Mn K-edge (1.8951 Å, 1.8940 Å, 1.800 Å) using synchrotron radiation at ELETTRA\u27s Sincrotrone Trieste \u27XRD\u27 beamline. This is one of the longest wavelength K-edge MAD studies undertaken to date. Anomalous and dispersive Patterson maps are seen to be of high quality and indicate a high occupancy for the manganese binding site. This is confirmed also in the MAD phase determination and electron density maps. Finally 0.92 Å data recorded at CHESS indicates the prospects available for combined phasing strategies based on MAD to medium/high resolution along with ultra high resolution data
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