805 research outputs found

    Modelado y simulación con Catia del torno Danobat NI-650

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    El presente trabajo de fin de grado consiste en modelar y simular un torno de control numérico mediante el uso del software comercial Catia v5. El trabajo se presenta dividido en dos partes: En la primera parte se realiza una breve descripción de las máquinas de mecanizado por arranque de viruta, centrándose en los tornos y su funcionamiento, así como su evolución a lo largo del tiempo desde sus orígenes hasta la actualidad, incluyendo la implantación del Control Numérico Computarizado (CNC) en las mismas. En particular, la máquina objeto de estudio es un torno de Control Numérico Computarizado modelo DANOBAT NI-650. La segunda parte se centra en el modelado y la simulación de la máquina mediante varios módulos del software Catia V5. Destacan principalmente NC Machine Tool Builder y NC Machine Tool Simulation.Departamento de Ciencias de los Materiales e Ingeniería Metalúrgica, Expresión Gráfica en la Ingeniería, Ingeniería Cartográfica, Geodesia y Fotogrametría, Ingeniería Mecánica e Ingeniería de los Procesos de FabricaciónGrado en Ingeniería Mecánic

    Conflicto trabajo-familia y percepción de autoeficacia parental en padres con hijos con discapacidad de escuelas especiales de Talca

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    132 p.La presente investigación tiene como objetivo determinar la relación entre los tipos de interacción familia-trabajo con el nivel de autoeficacia parental percibido por una muestra de padres con hijos con discapacidad, considerando las características de los tipos de discapacidad como un factor negativo que genera diferencias significativas, tanto en los niveles de autoeficacia como en los tipos de interacción, que pueden llevar a un conflicto entre la familia y el trabajo. La muestra de este estudio compone un total de 133 apoderados pertenecientes a 7 escuelas especiales de la ciudad de Talca. Los datos fueron recolectados aplicando la Escala de Evaluación Parental o EPP (Farkas, 2008) para la variable de autoeficacia parental y la versión española 71 del cuestionario SWING (Geurts, Taris, Kompier, Dikkers, Van Hooff & Kinnunen, 2005) para la evaluación de interacción trabajo-familia. Los resultados obtenidos demuestran que no existe una asociación entre los tipos de interacción trabajo-familia y la autoeficacia parental para esta población, en este sentido se diferencia de los resultados de otras investigaciones con población chilena (Riquelme y Rojas, 2010; Jiménez, Concha y Zúñiga, 2012) teniendo como explicación plausible la diferencia en el nivel educacional entre las muestras de las investigaciones. La interacción trabajo-familia es preponderantemente positiva y nace a partir de la familia hacia el trabajo (x=10,55; σ=4,19), la percepción autoeficacia parental para los padres con hijos con discapacidad resulta ser baja (x=48,95; σ=15,19) como era esperable por razones de estrés parental. No se observan diferencias significativas entre los tipos de discapacidad para ninguna de las dos variables, concluyendo que la discapacidad se establece como una condición única para todos los apoderados y es la familia la que cambia, se reorganiza para mantener un buen funcionamiento familiar./Palabras clave: Discapacidad, Autoeficacia Parental, Conflicto Trabajo-Familia, Equilibrio Trabajo-Familia, Trabajo-Familia./ABSTRACT: This research aims to determine the relationship between the types of work-family interaction with the level of parental self-efficacy perceived by a sample of parents with children with disabilities, considering the characteristics of the types of disability as a negative factor that generates significant differences, both self-efficacy levels and the types of interaction, which can lead to conflict between family and work.The study sample comprised a total ofInteracción 133 agents belonging to 7 special schools in the city of Talca. Data were collected using Parental Rating Scale or EPP (Farkas, 2008) for parental self-efficacy variable and the Spanish version of the questionnaire 71 SWING (Geurts, Taris, Kompier, Dikkers, Van Hooff & Kinnunen, 2005) for evaluation work-family interaction. The results show that there is an association between the types of work-family interaction and parental self-efficacy for this population, in this respect it differs from the results of other research with Chilean population (Riquelme and Rojas, 2010; Jimenez, Concha y Zúñiga, 2012) having as plausible difference in educational attainment between the research samples. The work-family interaction is positive and arises predominantly from family to work (x = 10.55, σ = 4.19), parental self-efficacy perception for parents with children with disabilities is to be low (x = 48 , 95, σ = 15.19) as expected for reasons of parental stress. No significant differences between the types of disability for any of the two variables, concluding that disability is established as a unique condition for all parents and family that changes, reorganizes to maintain a good family functioning. Keywords: Disability, Parental Self-Efficacy, Work-Family Conflict, Work-Family Balance, Work-Family Interaction

    A random forest approach to explore how situational variables affect perceived exertion of elite youth soccer players

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    Producción CientíficaThe aim of this study was to explore how situational variables affect youth soccer players’ perceived exertion (RPE) after official matches. Thirty-five elite youth male players (14.33 ± 0.86 years; 173.49 ± 6.16 cm; 63.44 ± 5.98 kg) who belonged to two different teams of a professional club participated in this study. Data collection was conducted during two seasons (2016–2017, 2017–2018) and included 60 official matches (30 official matches per team). Ten minutes after each match players rated their RPE and using a modified Borg CR-10 scale. A Random Forest Regression was used to quantify the importance of match-related situational variables in RPE. Afterwards, a linear mixed model analysis was applied to identify the variability in RPE among the situational variables. The game-playing time, the player status (starter or substitute) and the player identity were the strongest predictors of RPE. Moreover, the match outcome and the final scoreline showed significant effects on both starter and substitute players but the main effect of the quality of the opponent was only identified in starter players (p < 0.05). These results allow practitioners to know how situational variables interact and modulate RPE after official matches and help them to prescribe and adapt the players’ training content and load before and after matches

    Desenvolupament d'un sistema de comunicacions integrat per part d'estudiants de 2on cicle de l'ETSETB de la Universitat Politècnica de Catalunya

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    El projecte ha consistit en el disseny i fabricació d’un circuit integrat que conté un receptor Bluetooth per a xarxes sense fils en una tecnologia CMOS de 0,35 m. Els objectius del projecte eren realitzar una experiència de treball tutelat en el camp del disseny de circuits integrats avançats per part d’estudiants de 2on. cicle de l’ETSETB a través del qual poguessin aplicar els coneixements adquirits en diferents assignatures a un projecte comú, alhora que aprenien a fer servir les eines i els procediments de disseny professionals en l’àmbit dels circuits microelectrònics. La peculiaritat de la metodologia és que els estudiants hi han treballat de forma voluntària durant l’horari no lectiu, tot i que aquesta activitat se’ls ha reconegut com crèdits ALE. Primer han hagut d’aprendre a fer servir les eines de disseny mitjançant uns tutorials d’autoaprenentatge desenvolupats pels professors i més tard s’enfrontaven al disseny i realització de sub-blocs senzills del disseny global. El treball dels estudiants ha fet possible el disseny d’un receptor integrat complert en un temps d’uns 12 mesos que s’acaba d’enviar a fabricar

    Ultramafic-hosted volcanogenic massive sulfide deposits from Cuban ophiolites

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    Ultramafic-hosted volcanogenic massive sulfide deposits (UM-VMS) located in the Havana-Matanzas ophiolite (Cuba) are the only known example of this type of mineralization in the Caribbean realm. UM-VMS from Havana- Matanzas are enriched in Cu, Ni, Co, Au, and Ag. The mineralization consists of massive sulfide bodies mostly composed of pyrrhotite and hosted by serpentinized upper mantle peridotites. Chemical composition of unaltered cores in Cr-spinel grains found within the massive sulfide mineralization and in the peridotite host indicates formation in the fore-arc region of the Greater Antilles volcanic arc. A first stage of serpentinization probably took place prior to the sulfide mineralization event. The UM-VMS mineralization formed by the near-complete replacement of the silicate assemblage of partially serpentinized peridotites underneath the seafloor. The sequence of sulfide mineralization has been divided into two stages. The first stage is characterized by a very reduced hydrothermal mineral assemblage consisting of pyrrhotite, Co–Ni–Fe diarsenides, chalcopyrite, Co-rich pentlandite, and electrum. In the second stage, pyrite and Co–Ni–Fe sulfarsenides partially replaced pyrrhotite and diarsenides, respectively, under a more oxidizing regime during the advanced stages of ongoing serpentinization. The proposed conceptual genetic model presented here can be useful for future exploration targeting this type of deposit in the Caribbean region and elsewhere.Spanish Government PI0975CAP Investigacion PUCP-2022 Program PID 2019- 105625RB-C21MCIN/AEI PRE 2020-092140 2022-A- 004

    DLL's behavioral modeling for power consumption and jitter fast optimization

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    This paper analyzes the sources of jitter in a DLL and presents a behavioral model for fast DLL optimization. An algorithm to simulate the DLL in open loop is demonstrated. This procedure, together with the behavioral modeling, greatly reduces the simulation time of DLL when compared to the closeloop DLL simulation. In order to optimize the DLL performance, the dependence of the output jitter versus the power consumption is studied.Postprint (author’s final draft

    Providing an UWB-IR BAN wireless communications network and its application to design a low power transceiver in CMOS technology

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    Ultra Wide-Band (UWB) communication techniques have received increasing attention since United States Federal Communications Commission (FCC) adopted a “First Report and Order” in 2002. Unfortunately the regulations that appeared a few years latter didn't have the same level of commitment and had much tighter constraints. The FCC part. 15 power spectral density limitation is depicted. Although the word-wide common bandwidth is quite scarce (7.25 to 8.5 GHz), UWB still has its niche applications. Impulse Radio (IR) implementation of UWB systems has very interesting features such as low complexity, low power consumption, low cost, high data-rate, and the ability of coexistence with other radio systems.Peer ReviewedPostprint (published version

    A track record of Au–Ag nanomelt generation during fluid‑mineral interactions

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    This research was financially supported by Grant PID 2019-105625RB-C21 funded by MCIN/AEI/10.13039/501100011033, by Grant 2021 SGR 00239 funded by Gestió d’Ajuts Universitaris i de Recerca de Catalunya. Additional funding was provided by a “Ayudas predoctorales 2020” number PRE 2020-092140 PhD grant to DD-C by the Spanish Ministry of Science and Innovation and the Proyecto de Excelencia de la Junta de Andalucía (Spain), PROYECTEXCEL_00705 to JMGJ. Laura Casado (Instituto de Nanociencia de Aragón (INA)—University of Zaragoza) and María del Mar Abad (CIC, University of Granada) are acknowledged for her assistance with FIB and HRTEM respectivelyThe online version contains supplementary material available at https:// doi. org/ 10. 1038/ s41598- 023- 35066-yRecent studies have reported the significant role of Au-bearing nanoparticles in the formation of hydrothermal gold deposits. Despite the ever-increasing understanding of the genesis and stability of Au-bearing nanoparticles, it is still unknown how they behave when exposed to hydrothermal fluids. Here, we study the nanostructural evolution of Au–Ag nanoparticles hosted within Co-rich diarsenides and sulfarsenides of a natural hydrothermal deposit. We use high-resolution transmission electron microscopy to provide a singular glimpse of the complete melting sequence of Au–Ag nanoparticles exposed to the hydrothermal fluid during coupled dissolution–precipitation reactions of their host minerals. The interaction of Au–Ag nanoparticles with hydrothermal fluids at temperatures (400–500 ºC) common to most hydrothermal gold deposits may promote melting and generation of Au–Ag nanomelts. This process has important implications in noble metal remobilization and accumulation during the formation of these deposits.MCIN/AEI/10.13039/501100011033, PID 2019-105625RB-C21Gestió d'Ajuts Universitaris i de Recerca de Catalunya 2021 SGR 00239Ministerio de Ciencia e Innovación PRE 2020-092140 PhDProyecto de Excelencia de la Junta de Andalucía PROYECTEXCEL_00705Instituto de Nanociencia de Aragón (INA)-Universidad de ZaragozaComisión de Investigaciones Científicas (CIC), Universidad de Granad

    Construcción de un banco de pruebas y limpieza de inyectores a gasolina

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    Research and development is a key part of evolution where science and technology play an important role in development, which seeks to improve living conditions to protect the environment. Gasoline combustion is a means having a high impact on the environment. Currently several auto companies have created green vehicles with less impact contributing to reducing pollutants. With these assessments and towards helping to improve the current conditions it is proposed to conduct an investigation based on the test benches of electromagnetic injectors and maintenance, for proper maintenance of combustion engines allow the vehicle and the engine work efficiently and therefore less polluting. Optimization is generated when the injectors meet a rigorous maintenance and cleaning by ultrasound and the test bench, where it is verified that the operation of the injectors meets the standards to be followed under the use of manual order to ensure due process and handling of the injectors for optimum combustion and efficient engine operation. Proper maintenance is given by the control and supervision; this means that the vehicle must meet 30 thousand kilometers to access its first maintenance and cleaning for optimal performance of the injector.La investigación y desarrollo es parte fundamental de la evolución en donde la ciencia y tecnología juegan un papel importante en el desarrollo, en donde se busca mejorar las condiciones de vida al cuidar el medio ambiente. La gasolina es un medio de combustión que tiene un alto impacto en el medio ambiente. En la actualidad varias empresas automovilísticas han creado vehículos ecológicos con menor impacto que aportan a la reducción de elementos contaminantes. Con estas acotaciones y en pro de ayudar a mejorar las condiciones actuales se ha propuesto realizar una investigación a base de los bancos de prueba de los inyectores electromagnéticos y su mantenimiento, pues un adecuado mantenimiento de los motores a combustión permitiría que el vehículo y el motor trabajen de forma eficiente y por tanto sea menos contaminante. La optimización se genera cuando los inyectores cumplen con un riguroso proceso de mantenimiento y limpieza mediante el ultrasonido y el banco de pruebas, en donde se verifica que el funcionamiento de los inyectores cumpla con los estándares que deben seguirse bajo el uso de manuales con la finalidad de garantizar un adecuado proceso y manipulación de los inyectores para lograr una óptima combustión y el funcionamiento eficiente del motor. Un mantenimiento adecuado se da mediante el control y supervisión; es decir que el vehículo debe cumplir con 30 mil kilómetros para acceder a su primer mantenimiento y limpieza para alcanzar un óptimo desempeño del inyector
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