3,148 research outputs found

    Electron microscopy study of CeOx–Pd/α-Al2O3 catalysts for methane dry reforming

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    We have investigated the interaction between Pd and Ce in a 0.47 wt % CeOx–Pd 1 wt %/ -Al2O3 catalyst that is used in the reforming reaction of CH4 with CO2. The freshly reduced catalyst was characterized by various electron microscopy techniques, such as elemental mapping, Z-contrast imaging, and electron energy-loss spectroscopy to understand the role of Ce on a microscopic scale. The high spatial resolution elemental mapping indicates that CeOx is located in close proximity of the palladium nanoparticles. High-resolution lattice images and energy-loss spectra obtained in the vicinity of the Pd particles show an anisotropic distribution of CeOx crystallites limited to the interface region between Pd and the substrate but not covering the surface of the Pd nanoparticles. Energy-loss near edge fine structure of Pd M edges reveals that the Pd nanoparticles are not oxidized.Fil: Moreno, M. S.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Wang, Feiya. National Institute for Nanotechnology; CanadáFil: Malac, M.. National Institute for Nanotechnology; CanadáFil: Kasama, T.. University of Cambridge; Reino UnidoFil: Gigola, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Costilla, Ignacio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Sánchez, M. D.. Universidad Nacional del Sur. Departamento de Física; Argentin

    Additional Physical Interventions to Conventional Physical Therapy in Parkinson’s Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

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    Parkinson's disease (PD) represents the second most common neurodegenerative disease. Currently, conventional physical therapy is complemented by additional physical interventions with recreational components, improving different motor conditions in people with PD. This review aims to evaluate the effectiveness of additional physical interventions to conventional physical therapy in Parkinson's disease. A systematic review and meta-analysis of randomized controlled trials were performed. The literature search was conducted in PubMed, Physiotherapy Evidence Database (PEDro), Scopus, SciELO and Web of Science. The PEDro scale was used to evaluate the methodological quality of the studies. A total of 11 randomized controlled trials were included in this review. Five of them contributed information to the meta-analysis. The statistical analysis showed favorable results for dance-based therapy in motor balance: (Timed Up and Go: standardized mean difference (SMD) = −1.16; 95% Confidence Interval (CI):(−2.30 to −0.03); Berg Balance Scale: SMD = 4.05; 95%CI:(1.34 to 6.75)). Aquatic interventions showed favorable results in balance confidence (Activities-Specific Balance Confidence: SMD=10.10; 95%CI:(2.27 to 17.93)). The results obtained in this review highlight the potential benefit of dance-based therapy in functional balance for people with Parkinson's disease, recommending its incorporation in clinical practice. Nonetheless, many aspects require clarification through further research and high-quality studies on this subject

    A new knock event definition for knock detection and control optimization

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    [EN] In this paper, the knock phenomenon is studied and characterized in the time-frequency domain. From the analysis results, a new knock event definition is proposed, which compares the excitation of the cylinder resonance produced by the autoignition of the end gas to that associated with the combustion. The new definition permits a more consistent differentiation between knocking and not knocking cycles than the classical approach in the literature, thus allowing the improvement of the knock control strategies. The new knock index proposed analyses the frequency spectrum of the pressure signal in two locations, i.e. near the maximum heat release and near the end of combustion, by using the fast Fourier transform and a window function, and it is compared with the classical MAPO definition, which consists on finding the maximum pressure oscillation in the time domain. Both indices have been implemented online in a four-stroke SI engine and its performance is illustrated by using a classical knock control strategy. Results obtained under different operating conditions demonstrate that the improved knock index definition can substantially reduce the variability of the spark advance angle control, avoiding strong knocking events and reducing engine vibration.Bares-Moreno, P.; Selmanaj, D.; Guardiola, C.; Onder, C. (2018). A new knock event definition for knock detection and control optimization. Applied Thermal Engineering. 131:80-88. https://doi.org/10.1016/j.applthermaleng.2017.11.138S808813

    Knock probability estimation through an in-cylinder temperature model with exogenous noise

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    [EN] This paper presents a new knock model which combines a deterministic knock model based on the in-cylinder temperature and an exogenous noise disturbing this temperature. The autoignition of the end-gas is modelled by an Arrhenius-like function and the knock probability is estimated by propagating a virtual error probability distribution. Results show that the random nature of knock can be explained by uncertainties at the in cylinder temperature estimation. The model only has one parameter for calibration and thus can be easily adapted online. In order to reduce the measurement uncertainties associated with the air mass flow sensor, the trapped mass is derived from the in-cylinder pressure resonance, which improves the knock probability estimation and reduces the number of sensors needed for the model. A four stroke SI engine was used for model validation. By varying the intake temperature, the engine speed, the injected fuel mass, and the spark advance, specific tests were conducted, which furnished data with various knock intensities and probabilities. The new model is able to predict the knock probability within a sufficient range at various operating conditions. The trapped mass obtained by the acoustical model was compared in steady conditions by using a fuel balance and a lambda sensor and differences below 1% were found. (C) 2017 Elsevier Ltd. All rights reserved.Bares-Moreno, P.; Selmanaj, D.; Guardiola, C.; Onder, C. (2018). Knock probability estimation through an in-cylinder temperature model with exogenous noise. Mechanical Systems and Signal Processing. 98:756-769. https://doi.org/10.1016/j.ymssp.2017.05.033S7567699

    A Novel Cause-Effect Variable Analysis in Enterprise Architecture by Fuzzy Logic Techniques

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    In this paper, or present a new integration approach for managing Information Technology variables within enterprise architecture in an integrated way. Additionially, a novel method based on fuzzy logic for cause-effect variable analysis is proposed as a useful support decision-making tool for companies in order to lmow the main actions they must perform for increasing their benefits. This is employed to assess the Integration Management System in Enterprises, based on Enterprise Architecture and Information Technology. We show as fuzzy logic plays an important role M this area due to these variables can be affected for multifactorial elements iinpregnated with uncertainty. The knowledge given by the experts is translated into dependence rules, Which have also been analyzed from a fuzzy point of view using a combination of two fuzzy techniques, namely, fuzzy relation equation theory and fuzzy graph. Firstly, fuzzy dependence rules are computed froth fuzzy relation equations and, secondly an analysis based on incidence subgraph is performed. The resulLisa strategic plan automatically generated from the data captured of each enterprise in which the most import variables to be improved are detailed. (C) 2020 The Authors. Published by Atlantis Press SARI.

    Irradiation of carbon nanotubes with carbon projectiles: A molecular dynamics study

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    The irradiation of carbon based nanostructures with ions and electrons has been shown to be an appropriate tool to tailor their properties. The defects induced in the nanostructures during irradiation are able to modify their mechanical and electronic properties. Here we simulate the irradiation of carbon nanotubes with carbon ions using a molecular dynamics code. We use the Tersoff potential joined smoothly to the Universal Ziegler-Biersack-Littmark potential at short distances. We study the number of defects produced after irradiation with a single carbon ion finding a saturation with its energy at ∼ 3 keV. We observe, after continuum irradiation with low energy ions, the formation of bumps in the irradiated region. For larger energy ions we find that the diameter of the nanotube shrinks as shown in previous works.This work has been financially supported by Project FIS2010-17225 by the Spanish Ministerio de Ciencia e Innovación

    Genomic Promoter Analysis Predicts Functional Transcription Factor Binding

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    Background. The computational identification of functional transcription factor binding sites (TFBSs) remains a major challenge of computational biology. Results. We have analyzed the conserved promoter sequences for the complete set of human RefSeq genes using our conserved transcription factor binding site (CONFAC) software. CONFAC identified 16296 human-mouse ortholog gene pairs, and of those pairs, 9107 genes contained conserved TFBS in the 3 kb proximal promoter and first intron. To attempt to predict in vivo occupancy of transcription factor binding sites, we developed a novel marginal effect isolator algorithm that builds upon Bayesian methods for multigroup TFBS filtering and predicted the in vivo occupancy of two transcription factors with an overall accuracy of 84%. Conclusion. Our analyses show that integration of chromatin immunoprecipitation data with conserved TFBS analysis can be used to generate accurate predictions of functional TFBS. They also show that TFBS cooccurrence can be used to predict transcription factor binding to promoters in vivo

    Plasticity in the morphology of the fused frontals of Albanerpetontidae (Lissamphibia; Allocaudata)

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    Albanerpetontidae form an enigmatic extinct group of lissamphibians, ranging from the early Bathonian to the early Pleistocene. The Upper Jurassic outcrops of Portugal yield a large collection of material, suitable for addressing the intraspecific variation in and diagnostic potential of the characteristic fused frontals. We revise 58 specimens from the Guimarota beds of the Kimmeridgian Alcobaca Formation and describe 62 new frontal bones from the Kimmeridgian - Tithonian Lourinha Formation. Smaller specimens exhibit a vermicular dorsal ornamentation, while it is polygonal in larger specimens and other albanerpetontids. Compared to small specimens, larger specimens display: (1) larger ventrolateral crests extending posteriorly after the parietal margin; (2) a relatively shorter internasal process; (3) a frontal width across posterior edges relatively smaller; and (4) a ventromedian crest less pronounced. Morphometric analyses suggest a single species with different ontogenetic stages. Specimens are attributed to aff. Celtedens sp., based on a bell-shaped outline with a curved orbital margin (although variable in Portuguese specimens), and a flabellate, bulbous-shaped internasal process. The species is more similar to C. megacephalus than C. ibericus, but its phylogenetic position comprises an unresolved trichotomy. Our results show that intraspecific variation and homoplasy render the fused frontal non-diagnostic below the generic level

    ADQPCI: Data Acquisition Board for Educational purposes

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    En este trabajo se presenta una de las placas de adquisición de datos que se ha desarrollado con fines docentes para su utilización en prácticas relacionadas con sistemas en tiempo real e informática industrial y se plantean algunas de las ventajas e inconvenientes frente a la utilización de placas comerciales. A lo largo del trabajo se detalla el diseño del hardware, en el que se ha priorizado la facilidad de programación, siendo ésta una de las ventajas frente a las placas comerciales. En estas prácticas es fundamental que el alumno tome conciencia de la importancia de la interfaz hardware-software, si se quiere conseguir un sistema fiable y que explote al máximo las características del hardware. Con el desarrollo de una placa de adquisición de datos se consigue un sistema que el alumno puede utilizar en varias asignaturas de su titulación que están relacionadas con el desarrollo y programación de sistemas empotrados.In this work a data acquisition board developed for educational use in subjects related to real-time systems and industrial computing, is presented. The main advantages and disadvantages of using these boards versus the use of commercial boards are discussed. The hardware design described along this work emphasizes the facility of programming the board, which is one of the main advantages versus the commercial boards. In these practices it is essential that student comprehend the importance of the hardware-software interface in order to obtain a reliable system which exploits in a maximum way the characteristics of the hardware. The development of a data acquisition board allows to obtain a system that the students can use in several course during his university career which are related to the development and programming of embedded system

    CAN2PCI: Board with Interface to CAN and PCI Bus for educational purposes

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    En este trabajo se presenta una placa con interfaz al bus CAN y PCI desarrollada para la utilización en prácticas de las asignaturas relacionadas con redes de control. Se trata de una placa de altas prestaciones pensada para su utilización docente gracias a su facilidad de programación. La placa dispone de dos canales CAN independientes y permite acceso directo a los registros del controlador CAN. Las prácticas tienen como objetivo conocer la red de control en los niveles físico y de enlace y desarrollar un software de conectividad (middleware) que realice la interfaz entre estas capas y la de aplicación de usuario. Se exponen también brevemente las prácticas realizadas en una de las asignaturas donde se imparte redes de control, en la que es fundamental la utilización de un hardware conocido que permita programar las funciones básicas que operan directamente con el controlador de bus CANIn this work the development of a board with interface to the CAN and PCI bus for its use in lab courses related to control networks, is presented. This board has high benefits and advantages and has been implemented for educational purposes due to its programming facility. The board has two independent CAN channels and it allows direct access to the registers of the CAN controller. The objective of the lab experiments is to study the control networks in the physical and link levels and to develop a middleware that performs the interface between these layers and the user application. The experiments done in one of the courses, which includes control networks, are briefly described. In these practical labs it is very important the use of a known hardware that allows programming the basic functions which directly operate with the CAN bus controlle
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