Servicio al cliente, una salida a los conflictos entre la comunidad universitaria y los controles de la seguridad privada

El presente trabajo tiene como finalidad consolidar un documento en donde se encuentren herramientas claras para que las empresas de seguridad puedan desarrollar su labor de una manera efectiva y eficaz, y con las cuales puedan mejorar el proceso de atención al cliente, para los contratos de servicios de vigilancia y seguridad privada en centros universitarios, así mismo, contar con un sistema de seguridad que permita a los grupos de interés reconocer su corresponsabilidad frente al tema de seguridad personal, colectiva, de las edificaciones y los bienes materiales. El sistema de seguridad en las universidades con un efectivo servicio al cliente busca que la comunidad universitaria se integre a través del espíritu de solidaridad, hermandad y compañerismo con el ánimo de unir esfuerzos y contrarrestar los actos delincuenciales que atentan contra la comunidad académica y los bienes de las instituciones universitarias, de la misma manera encontrar una solución a la problemática que se evidencia a diario y que se vive en los centros educativos universitarios en donde el guarda de seguridad esta en un constante conflicto con el estudiante universitario, afectando gravemente la imagen de las empresas de seguridad y opacando el animo con el que los jóvenes estudiantes llegan a los centros de educación superior públic

Suitable sealants for cracked aluminized austenitic steels and their oxidation behaviour

International audienceAluminizing of steels may result in the appearance of tensile cracks from the coating surface to the substrate due to the difference in thermal expansion coefficients. The cracks often need to be sealed to make the coatings impervious to chemical attack and to limit their mechanical degradation. In this work, dipping of the cracked aluminide coatings elaborated on IN-800HT in 0.5, 1 and 3.75 mol.L-1 concentrations of H3PO4 in acetone and increasing the dipping time are investigated. The three concentrations resulted in the formation of P-O compounds and of Al2O3. However, the 0.5 mol.L-1 allowed better wetting of the surface. Further reduction of the concentration from 0.5 mol.L-1 to 0.2 mol.L-1 brought about the complete sealing of both large and fine cracks. The efficiency of the sealing process with 0.2 mol.L-1 and 0.5 mol.L-1 was thereafter evaluated by cyclic oxidation in air at 650°C for more than 1000 cycles. The overall microstructure and composition of the aluminide coatings remained identical after sealing and the oxidation behaviour comparable to the untreated counterparts. The oxide scale formed on the untreated samples appeared thicker compared to the sealed ones. The latter were covered by a thin layer of AlPO4 which evolved towards a thin protective alumina scale. However, for the sealed samples, some minor cracks were detected after oxidation but they appeared completely healed with Al2O3 and no propagation of them beyond the additive layer/interdiffusion zone was noticed

Characterisation of aluminium diffusion coatings elaborated on austenitic stainless steels and on ferritic-martensitic steels

International audienceSlurry aluminide coatings were elaborated on IN-800HT and HR3C austenitic stainless steels (ASS) and on P92 ferritic-martensitic steels. The thermal treatments conducted in Ar enabled the melting of Al and the high temperature synthesis with the substrate elements to result in an aluminium diffusion coating. Whether for the ferritic-martensitic or the austenitic stainless steels, the coatings were formed by the simultaneous Al inward diffusion into the steel matrix and the outward diffusion of Fe (and Ni for the ASS) on both steel substrates. As a result, the coatings exhibited a B2-(Fe,Ni)Al phase for the ASS and B2-FeAl phase for the P92 substrate. A reduction of the grain size after annealing was noticed for the ASS but their microstructures remained mostly austenitic. However, a significant increase of the grain size occurred in the P92 steel with a transformation from the initial tempered martensitic structure to an austenitic structure. The microhardness of the ASS did not change significantly whereas for P92, a large increase occurred

Amyloid Beta Peptide Slows Down Sensory-Induced Hippocampal Oscillations

Alzheimer's disease (AD) progresses with a deterioration of hippocampal function that is likely induced by amyloid beta (Aβ) oligomers. Hippocampal function is strongly dependent on theta rhythm, and disruptions in this rhythm have been related to the reduction of cognitive performance in AD. Accordingly, both AD patients and AD-transgenic mice show an increase in theta rhythm at rest but a reduction in cognitive-induced theta rhythm. We have previously found that monomers of the short sequence of Aβ (peptide 25–35) reduce sensory-induced theta oscillations. However, considering on the one hand that different Aβ sequences differentially affect hippocampal oscillations and on the other hand that Aβ oligomers seem to be responsible for the cognitive decline observed in AD, here we aimed to explore the effect of Aβ oligomers on sensory-induced theta rhythm. Our results show that intracisternal injection of Aβ1–42 oligomers, which has no significant effect on spontaneous hippocampal activity, disrupts the induction of theta rhythm upon sensory stimulation. Instead of increasing the power in the theta band, the hippocampus of Aβ-treated animals responds to sensory stimulation (tail pinch) with an increase in lower frequencies. These findings demonstrate that Aβ alters induced theta rhythm, providing an in vivo model to test for therapeutic approaches to overcome Aβ-induced hippocampal and cognitive dysfunctions

Development of thermal barrier coating systems from Al microparticles. Part I: Influence of processing conditions on the mechanisms of formation

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Diseño hardware de la transformada wavelet discreta: un análisis de complejidad, precisión y frecuencia de operación

The purpose of this paper is to present a comparative analysis of hardware design of the Discrete Wavelet Transform (DWT) in terms of three design goals: accuracy, hardware cost and operating frequency. Every design should take into account the following facts: method (non-polyphase, polyphase and lifting), topology (multiplier-based and multiplierless-based), structure (conventional or pipelined), and quantization format (floatingpoint, fixed-point, CSD or integer). Since DWT is widely used in several applications (e.g. compression, filtering, coding, pattern recognition among others), selection of adequate parameters plays an important role in the performance of these systems.El propósito de este documento es presentar un análisis comparativo de esquemas hardware de la Transformada Wavelet Discreta, DWT, en términos de tres objetivos de diseño: precisión, complejidad y frecuencia de operación. Cada diseño debe considerar los siguientes aspectos: método (no polifásico, polifásico y lifting), topología (basados en multiplicadores y sin multiplicadores), estructura (convencional o pipeline) y formato de cuantización (punto flotante, punto fijo, CSD o entero). Dado que la DWT es ampliamente utilizada en diversas aplicaciones (por ejemplo en compresión, filtrado, codificación, reconocimiento de patrones, entre otras), la selección adecuada de parámetros de diseño desempeña un papel importante en el diseño de estos sistemas

Effect of the pH of the electrolyte on the formation and on the corrosion properties of ceria based coating on carbon steel

International audienceThe effects of the modification of the pH in 0.1M cerium nitrate solutions in the elaboration and corrosion resistance of ceria based coatings on carbon steel are investigated. Increasing the concentration of acetic acid impedes an efficient electrodeposition. At low concentrations, acetic acid seems to prevent the precipitation of Ce(OH)3 and the formation of even films of cerium oxides is favoured. The increase of pH through the addition of NaOH to the cerium nitrate solutions with 0.008M of acetic acid is shown to provide superior corrosion resistance for exposures in air and immersed in 0.5M NaCl for 30 days

Effect of the temperature of cerium nitrate–NaCl solution on corrosion inhibition of mild steel

International audienceIn this work, the effect of temperature on corrosion inhibition was studied in the absence and presence an optimal concentration of cerium nitrate (600 mg.L-1) as an inhibitor of mild steel in sodium chloride. Corrosion tests were carried out through electrochemical techniques such as impedance spectroscopy and d.c polarization measurements. The surface morphology of the films was investigated by optical microscopy (MO), white light interferometry (WLI) and a scanning electronic microscopy (SEM) coupled to EDS analysis for chemical composition. The results obtained show that the activation energy for the corrosion inhibition process to occur increased in the presence of cerium nitrate inhibitor. However, the corrosion resistance of mild steel was somewhat lost with increasing the solution temperature up to 55 °C, which lead to more cracked films. The enthalpy and entropy values suggested a mixed mechanism of chemisorption and physisorption inihibition, with a major dominant of physisorption control

Sistema de ahorro energético con sensor inalámbrico de sueño

In the following paper, perform the development and evaluation of a device capable of identifying the sleep state of a person from the measurement of the respiratory frequency, integrating it into a Z-Wave system to perform spatial domotic control. It was evidenced, by means of the analysis of electrical consumption tests, how the implementation of the system generates a significant saving of 38% with respect to the average monthly consumption in a house, and how its application contributes to an environment conducive to sleep by reducing noise that generate the multimedia equipment in the room -off immediately after a detection-. The correct functioning of the sensor is observed due to the characteristics of the measurements of quality of service (QoS) parameters: Delay, Throughput and Jitter, guaranteeing that the loss of information is null and that the system implemented is viable.En el siguiente artículo se realiza el desarrollo y evaluación de un dispositivo capaz de identificar el estado de sueño de una persona a partir de la medición de la frecuencia respiratoria, integrándolo a un sistema tipo Z-Wave para realizar control domótico espacial. Se evidenció, por medio del análisis de pruebas de consumo eléctrico, cómo la implementación del sistema genera un ahorro significativo del 38% con respecto al consumo promedio mensual en una vivienda, y cómo su aplicación contribuye con un entorno propicio para dormir al disminuir el ruido que generan los equipos multimedia en la habitación -apagados inmediatamente después de una detección-. Se observa un correcto funcionamiento del sensor por las características de las mediciones de los parámetros de calidad de servicio (QoS): Delay, Throughput y Jitter, garantizándose que la pérdida de información es nula y que el sistema implementado es viable.&nbsp

Sueño de caminante

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