1-D Harmonic Oscillator in Snyder Space, the Classic and the Quantum

The 1-D dimension harmonic oscillator in Snyder space is investigated in its classical and quantum versions. The classical trajectory is obtained and the semiclassical quantization from the phase space trajectories is discussed. In the meanwhile, an effective cutoff to high frequencies is found. The quantum version is developed and an equivalent usual harmonic oscillator is obtained through an effective mass and an effective frequency introduced in the model. This modified parameters give us an also modified energy spectra.Comment: 8 pages, 2 figure

Buckling and postbuckling of dielectric composite beam reinforced with Graphene Platelets (GPLs)

Buckling and postbuckling behaviors of graphene platelet (GPL) reinforced dielectric composite beams are investigated through theoretical formulation. The effective material properties of the GPL reinforced composite (GPLRC) as required for structural analysis, i.e. tensile modulus, dielectric constant and Poisson's ratio are obtained by using effective medium theory and rule of mixture. Governing differential equations for the composite beam are established through Timoshenko beam theory, von Kármán nonlinear strain-displacement relationship and principle of virtual work. Governing equations are numerically discretized and solved by employing differential quadrature method (DQM), through which several parameters affecting the buckling performances are quantitatively identified. The results demonstrate there exists a critical GPL concentration, above which the electrical field significantly affects the beam's buckling and postbuckling behaviors. The dielectric beam's buckling performances are very sensitive to AC (alternating current) frequency within a certain range. Moreover, it is found the dielectric beam's buckling and postbuckling performances comprehensively depend on the concentration and aspect ratio of GPLs. The present work is envisaged to provide guidelines to develop GPL-based smart composites and structures.The work described in this paper is fully funded by a research grant from the Australian Research Council under Discovery Early Career Researcher Award (DECRA) scheme (DE160100086). The authors are grateful for the financial support from the Australian Research Council under Discovery Project scheme (DP160101978)

Energy absorption and residual bending behavior of biocomposites bumper beams

This paper presents and analyzes the behavior of bumper beams made of PLA/flax composites subjected to low velocity impacts. The relevance of this material resides in the biodegradability of both fibers and matrix. Moreover, the after-impact behavior of this composite is excellent due to the absence of delamination. Impact tests have been performed using a drop weight tower within the range of impact energies 5 J ≤ Eimp ≤ 73 J. The experimental setup enabled the measuring of impact velocity, residual velocity, load-time history and failure mode. Results show that damage generated during impact produces a significant reduction of residual stiffness but the residual strength is not affected by damage generated in the range of the applied impact energies considered

Returns to scale in water and sanitation: estimates for Latin America

Most countries around the world are strongly debating ways to yield more equitable access and a more efficient provision. One issue linked to efficiency is the achievement of scale economies in the industry and the optimal dimension of water and sanitation providers. Changes in the industrial structure of the sector, through mergers in highly atomized services, the breakup of very concentrated services, or the property discussion (private versus public) are major issues. These decisions have often become politicized because of the social complexity of the sector. Empirical findings of the different models reveal the existence of increasing returns to scale in Latin American water provision based on an ADERASA database (a 2005 cross section of 90 providers in 14 countries). The study of returns to scale incorporates a technical argument into the discussion because–as our study suggests–the prescription could be to agglomerate small providers.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Mercadier, Augusto C.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; ArgentinaFil: Romero, Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentin

Returns to scale in water and sanitation: estimates for Latin America

Most countries around the world are strongly debating ways to yield more equitable access and a more efficient provision. One issue linked to efficiency is the achievement of scale economies in the industry and the optimal dimension of water and sanitation providers. Changes in the industrial structure of the sector, through mergers in highly atomized services, the breakup of very concentrated services, or the property discussion (private versus public) are major issues. These decisions have often become politicized because of the social complexity of the sector. Empirical findings of the different models reveal the existence of increasing returns to scale in Latin American water provision based on an ADERASA database (a 2005 cross section of 90 providers in 14 countries). The study of returns to scale incorporates a technical argument into the discussion because–as our study suggests–the prescription could be to agglomerate small providers.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Mercadier, Augusto C.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; ArgentinaFil: Romero, Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentin

Algoritmos Evolutivos para Descubrimiento de Reglas de Predicción en la Mejora de Sistemas Educativos Adaptativos basados en Web

Este artículo muestra la utilización de los algoritmos evolutivos para el descubrimiento de reglas de predicción que se utilizarán en la mejora de Cursos Hipermedia Adaptativos basados en Web. Se ha desarrollado una herramienta de minería de datos específica para descubrir relaciones entre los datos de utilización recogidos durante las ejecuciones de los distintos alumnos. Esta información puede ser de gran utilidad para el profesor o autor del curso, para la toma de decisiones sobre qué modificaciones son las más adecuadas para mejorar el aprendizaje de los alumnos. Para la realización de la búsqueda de reglas de predicción se ha utilizado programación genética basada en gramáticas multi-objetivo y se han comparado con algoritmos clásicos de descubrimiento de reglas.In this paper we show the use of evolutionary algorithms for discovering prediction rules to improve web-based adaptive hypermedia courses. We have developed a specific data mining tool to discover relationship between the usage data pickup during the execution of different students. This information can be very useful to the courseware author in order to make decisions about what are the most appropriated modifications to improve the learning of the students. In order to do prediction rule discovering we have used multi-objective grammar-based genetic programming and we have compared it with other classic algorithm for rule discovering

Hydrogen sulfide: From a toxic molecule to a key molecule of cell life

Hydrogen sulfide (H2S) has always been considered toxic, but a huge number of articles published more recently showed the beneficial biochemical properties of its endogenous production throughout all regna. In this review, the participation of H2S in many physiological and pathological processes in animals is described, and its importance as a signaling molecule in plant systems is underlined from an evolutionary point of view. H2S quantification methods are summarized and persulfidation is described as the underlying mechanism of action in plants, animals and bacteria. This review aims to highlight the importance of its crosstalk with other signaling molecules and its fine regulation for the proper function of the cell and its survival.EU Marie Skłodowska-Curie 834120Junta de Andalucía US-125578

Effects of a neuroscience-based instructional guide on college student learning

The article aims to demonstrate the impact of neuroscience as an instructional strategy on student learning. This was an experimental research with a pre-experimental design that used a sample of 60 students on the Mathematics 1.0 course of the first cycle of the Continental University in the Academic period II - 2021. Significant contrasts were found between the results obtained before and after the application of the designed instructional guide, since the T value obtained is related with a significance level lower than 0.01, confirming the research hypothesis. When evaluating the effect of the application of the instructional guide with neuroscience as a strategy, it is shown to favorably affect the learning of students of the Mathematics 1.0 course of the first cycle of the Continental University, strengthening the entire learning process so that these can become meaningful. Therefore, it is recommended to continue implementing the instructional guide in all higher education courses without being limited to a single course as in the present study, as well as continue researching on the subject with larger samples.Campus Lima Centr

Modified Brans-Dicke theory of gravity from five-dimensional vacuum

We investigate, in the context of five-dimensional (5D) Brans-Dicke theory of gravity, the idea that macroscopic matter configurations can be generated from pure vacuum in five dimensions, an approach first proposed in the framework of general relativity. We show that the 5D Brans-Dicke vacuum equations when reduced to four dimensions lead to a modified version of Brans-Dicke theory in four dimensions (4D). As an application of the formalism, we obtain two five-dimensional extensions of four-dimensional O'Hanlon and Tupper vacuum solution and show that they lead two different cosmological scenarios in 4D.Comment: 9 page