Slide-Down Prevention for Wheeled Mobile Robots on Slopes

Wheeled mobile robots on inclined terrain can slide down due to loss of traction and gravity. This type of instability, which is different from tip-over, can provoke uncontrolled motion or get the vehicle stuck. This paper proposes slide-down prevention by real-time computation of a straightforward stability margin for a given ground-wheel friction coefficient. This margin is applied to the case study of Lazaro, a hybrid skid-steer mobile robot with caster-leg mechanism that allows tests with four or five wheel contact points. Experimental results for both ADAMS simulations and the actual vehicle demonstrate the effectiveness of the proposed approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Atactic polypropyle. From industrial by-product to high added value material for advanced applications through chemical modification processes

En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.-- 3 pages.This work is related to the conversion of an industrial by product (or waste) coming from polymerization reactors, as the atactic polypropylene is considered, into materials to be used as interfacial modifiers in heterogeneous materials based on polymers. In fact, this work concerns with the obtain of interfacial modifiers by chemical modification of the polymer by grafting of polar monomers either by one step processes to graft succinic anhydride (SA) or p-phenylen-bis-maleamic acid (pPBM) onto the polymer backbone, or by a two step process to yield succinil-fluoresceine grafted atactic polymers from the modified with SA. The comparison of these chemical processes both in solution and in the melt has allow to us to establish a reaction mechanism, and as a consequence, to obtain interfacial agents with very different functionalities and molecular architectures providing the researcher the ability to design taylor-made advanced materials such as micro- and nano-structured blends, alloys and composites, becoming the interfacial modifiers as the key for their advanced ultimate properties.Peer reviewe

Swirl ratio and post injection strategies to improve late cycle diffusion combustion in a light-duty diesel engine

[EN] Nitrogen oxides (NOx) and soot emissions are the most important pollutants from direct-injection diesel engines. In particular, soot formation and oxidation determine the net engine-out soot emissions. These phenomena are complex and competing processes during diesel combustion. Despite many researches implicate the mechanisms of soot formation with soot emissions, the enhancement of the late cycle soot oxidation is the dominant mechanism for a reduction of engine-out soot emissions. The mixing process and the in-cylinder bulk temperature are two important parameters in the development of soot oxidation process. The current research compares different engine strategies to enhance the late cycle mixing controlled combustion process and therefore enhance soot oxidation while maintaining similar gross indicated efficiency in a light-duty engine. For this purpose, a simplified methodology has been used, which analyzes the effect of mixing process and in-cylinder bulk gas temperature on soot oxidation during the late cycle combustion. For carrying out this research, theoretical and experimental tools were used. In particular, the experimental measurements were made in a single-cylinder direct-injection light-duty diesel engine varying the swirl ratio and the injection pattern as injection pressure, Start of Energizing (SoE), Energizing Time (ET) and number of injections events. To analyze soot emissions, the combustion luminosity was measured by an optoelectronic probe and the optical thickness parameter (KL) was evaluated by the two-color pyrometry method. The apparent combustion time (ACT-1) was used as mixing time tracer. Results show that an increase in swirl ratio implies an improvement on the mixing process and higher values of average bulk temperature during the late-cycle diffusion combustion. Both phenomena produce an enhancement in the soot oxidation process. In the lowest swirl ratio case, a suitable injection strategy based on multiple injections, provides similar results of soot oxidation process (and therefore, the emissions) as high swirl ratio case. (C) 2017 Elsevier Ltd. All rights reserved.Benajes, J.; Martín, J.; García Martínez, A.; Villalta-Lara, D.; Warey, A. (2017). Swirl ratio and post injection strategies to improve late cycle diffusion combustion in a light-duty diesel engine. Applied Thermal Engineering. 123:365-376. doi:10.1016/j.applthermaleng.2017.05.101S36537612

Temperature-independent quantum logic for molecular spectroscopy

We propose a fast and non-destructive spectroscopic method for single molecular ions that implements quantum logic schemes between an atomic ion and the molecular ion of interest. Our proposal relies on a hybrid coherent manipulation of the two-ion system, using optical or magnetic forces depending on the types of molecular levels to be addressed (Zeeman, rotational, vibrational or electronic degrees of freedom). The method is especially suited for the non-destructive precision spectroscopy of single molecular ions, and sets a starting point for new hybrid quantum computation schemes that combine molecular and atomic ions, covering the measurement and entangling steps.Comment: v3. Substantially enlarged manuscript with details of derivations and calculations in two appendices. To appear in PR

Seguridad y salud ocupacional en el sector industrial

The objective of this article was to analyze the impact of occupational safety and health (OSH) training on occupational incidents in an industry in Mexico. This training was given through an intervention in the USG Mexico industry, as a result of the implementation of the Plan-Do-Check-Act (PHVA) methodology. The methodology used was exploratory factor analysis to explain the correlation of the variables. The results showed that the implementation of the PHVA methodology was positively correlated with the decrease in accident rates in general, although the interdepartmental relationship was negative since there were significant differences in the areas of maintenance and production. These results demonstrate the opportunity for sustained improvement of working conditions and their immediate effects on productivity and competitiveness of the industries.El objetivo del presente artículo fue analizar el impacto de la capacitación en la seguridad y salud ocupacional (SySO) en una industria de México. Esta capacitación se dio a través de una intervención sobre en la industria USG México, como resultado de la implementación de la metodología Planear-Hacer-Verificar-Actuar (PHVA). La metodología utilizada fue la regresión lineal para explicar la correlación de las variables. Los resultados mostraron que la implementación de la metodología de PHVA se correlacionó positivamente con la disminución de los índices de siniestralidad de manera general, aunque de manera departamental las relaciones variaron entre los diversos departamentos que integran la industria. Estos resultados evidenciar la oportunidad para mejorar en forma sostenida las condiciones laborales y sus efectos inmediatos en la productividad y la competitividad de las industrias

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders

Caracterización, mediante espectroscopia EPR, de los catalizadores quirales bis (Oxazolina)-Cu soportados en Laponitas

[EN] An Electron Paramagnetic Resonance study of a chiral Bis(oxazoline)-Cu(II) supported in laponite (synthetic hectorite) is presented. It is concluded that the complex is incorporated into the interllamellar space of the clay giving out isolated Cu(II) entities in which the metal is co-ordinated to oxygen or nitrogen atoms with a symmetry practically planar-square, regardless the solvent used. That point out that the chlorine ligands in the complex are exchanged in the incorporation process in agreement with the previous X-ray absorption spectroscopy data, so that the oxygen atoms of the interlayers and clay surface act as counterions.[ES] Se presenta un estudio mediante Resonancia Paramagnética Electrónica del complejo quiral Bis(oxazolina)-Cu(II) soportado en laponita (hectorita sintética) (libre de hierro. Del mismo se concluye que el complejo se incorpora en el espacio interlamelar de la arcilla dando lugar a entidades de Cu(II) aisladas en las cuales el metal se coordina a átomos de oxígenos y nitrógenos con una simetría prácticamente planocuadrada, independientemente del disolvente empleado. Ello indica, de acuerdo con los datos previos de espectroscopia de absorción de rayos-X, que los ligandos cloruro del complejo son intercambiados en el proceso de incorporación de forma que los oxígenos de la superficie interlaminar y externa de la arcilla actúan como contraiones.This work has been partially supported by the CICYT (project MAT99-1176).Peer reviewe

Obtención semiautomática de elementos estructurantes en pequeños entornos urbanos: hacia una integración de UVaCAD y CityGML

El objetivo de este trabajo es mostrar algunos desarrollos recientes relacionados con la integración de métodos y herramientas de Sistemas de Información, Procesamiento y Visualización de Datos Geoespaciales en un marco 3D. Con ello se pretende facilitar un marco común que afecta a las fases de toma de datos, procesamiento y análisis de la información, diseño, planificación y gestión de intervenciones relacionadas con la construcción de edificios y modificación de pequeño entornos urbanos. La clave para facilitar la integración de modelos y la interoperabilidad entre herramientas es el desarrollo de un marco semántico. El estándar abierto CityGML define clases y relaciones generales relativos a la gestión de espacios físicos según un modelo geométrico (que extiende el enfoque vectorial típico de los SIG). En este trabajo se añaden algunas funcionalidades ligadas a herramientas de procesamiento y análisis de la información de rango 3D de pequeños entornos urbanos capturada con dispositivos láser terrestres de gran precisión. El software UvaCad desarrollado por el clúster DAVAP proporciona un soporte para la fusión de información de imagen 2D y de rango 3D. Sobre el modelo 3D resultante se ha diseñado e implementado un módulo para la gestión de información sobre edificaciones para los niveles 1 y 2 de CityGML. Gracias a la organización conceptual modular de CityGML, es posible extender el modelo original para incorporar información extraída automáticamente sobre poligonales de planos dominantes a los que se superponen diferentes tipos de etiquetas. La extracción de esta información se lleva a cabo de forma semiautomática y se almacena en forma de base de datos relacional con enlace a recursos obtenidos mediante herramientas de procesamiento y análisis de la información 2D y 3D, incluyendo a) extracción de información métrica a partir del modelo 3D; b) reproyección, corrección y referenciación volumétrica de información planar (vistas, planos, croquis) así como c) herramientas de Visualización Avanzada (incluyendo un módulo VR para simulación de intervenciones) organizadas por capas para facilitar el análisis, diseño y gestión a lo largo de las diferentes fases de las posibles intervenciones.Peer Reviewe

Effects of water stress on the phenolic compounds of ‘Merlot’ grapes in a semi-arid Mediterranean climate

Of all the abiotic stress types to which plants grown in fields are exposed, the most influential is water stress. It is well accepted that adopting controlled deficit irrigation strategies during the growing season has beneficial effects on the chemical compositions of grapes and red wines. However, there is a discrepancy in the timing, intensity and duration of deficit. This study aimed to evaluate the changes in phenolic composition of ‘merlot’ cultivar grapes when subjected to different levels of water stress in a semi-arid Mediterranean climate. Four treatments with different water stress levels were applied within two phenological intervals (flowering-veraison, veraison-maturity) to 128 grapevines for two consecutive years. The water stress levels for Treatments 1, 2, 3 and 4 were: no-light, light-moderate, moderate-intense and intense for the flowering-veraison and veraison-maturity intervals, respectively. Water stress distinctly affected the phenolic compounds in skin and seeds. The concentrations of flavan-3-ols and total polyphenols were much higher in seeds than in skin, and in both fractions, tannins are the major compound