Estudios de resistencia a la compresión en bloques de suelo-cemento

RESUMEN:Se describe un trabajo de investigación y transferencia, realizado en El Puestito (Burruyacu, Tucumán), cuyo objetivo principal es determinar la dosificación más adecuada para fabricar bloques de suelo-cemento que se utilizaran para la construcción de un prototipo de vivienda que responde a las características socio-culturales de los habitantes del lugar. Con dos muestras de suelo, se fabricaron probetas, haciendo dosificaciones con la mezcla de las dos muestras a la vez y con cada una por separado. Teniendo en cuenta lo indicado en Norma IRAM 1546, a los 28 días fueron sometidas a la compresión hasta la primera fisura, incrementando la misma hasta la rotura. Los resultados muestran que a medida que aumenta la presión de fabricación, aumenta la resistencia a la compresión y por otro lado, las dosificaciones en las cuales se aumenta la relación entre la cantidad de suelo 1 con respecto a la de suelo 2, producen un aumento de la resistencia a la rotura.We describe a research project and transfer, put in practice in El Puestito (Burruyacu, Tucumán), which main objective is to determine the proper dosage to produce soil-cement blocks that will be used for the construction of a housing prototype which meets to the socio-cultural characteristics of the local people. With two soil samples, specimens were made, with dosages of the mixture from both samples at a time and of each one of them separately. As indicated in IRAM 1546, after 28 days, they were subjected to compression until the first crack, increasing it to fracture point. The results show that with increasing pressure of manufacture, resistance to compression also increases and, on the other hand, dosages in which the amount of soil 1 vs. the amount of soil 2- ratio increases, end up producing an increased resistance to breakage.Fil: Mas, Jorge Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; ArgentinaFil: Kirschbaum, Carlos Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; Argentin

Evaluación rápida de la protección anticorrosiva de las pinturas (ACET): un desarrollo universitario llevado al mercado

Se presentan en este artículo los fundamentos básicos de la Técnica Electroquímica Cíclica Acelerada (ACET), desarrollada por la Universitat Jaume I y ofrecida al mercado por la spinoff Mediciones y Corrosión SL. El ensayo ACET permite en 24 horas determinar la protección anticorrosiva de una pintura, y por su comparación con muestras de referencia predecir su comportamiento en el ensayo de niebla salina

Detección del fenómeno de Bell previo al reflejo pupilar a la luz

Contribución como póster al Simposio de Ciencias de la Visión en la XI Reunión Nacional de ÓpticaEl desarrollo de un video-oculógrafo binocular con resolución 15 micras y 4 ms orientado a la caracterización de los reflejos pupilares ha revelado la existencia de un movimiento de elevación del globo ocular, conocido como fenómeno de Bell, previo al reflejo pupilar a la luz. Además, su uso para el análisis del reflejo pupilar a la luz ha confirmado que las respuestas pupilares directa y consensual no presentan ninguna diferencia temporal apreciabl

Method for targetless tracking subpixel in-plane movements

We present a targetless motion tracking method for detecting planar movements with subpixel accuracy. This method is based on the computation and tracking of the intersection of two nonparallel straight-line segments in the image of a moving object in a scene. The method is simple and easy to implement because no complex structures have to be detected. It has been tested and validated using a lab experiment consisting of a vibrating object that was recorded with a high-speed camera working at 1000 fps. We managed to track displacements with an accuracy of hundredths of pixel or even of thousandths of pixel in the case of tracking harmonic vibrations. The method is widely applicable because it can be used for distance measuring amplitude and frequency of vibrations with a vision system.Generalitat Valenciana (Regional Government of Valencia) (PROMETEO/2011/021); Ministerio de Economía y Competitividad (Ministry of Economy and Competitiveness) (BIA2011-22704); Universidad de Alicante (GRE13-10)

Caracterización y evaluación del bagazo de caña de azúcar como biosorbente de hidrocarburos

En la caracterización del biosorbente (bagazo de caña de azúcar natural, BN) se determinaron diferentes parámetros físico-químicos: humedad, densidad aparente, densidad real, porosidad, flotabilidad, capacidad máxima de sorción y microscopia electrónica de barrido. Los resultados obtenidos permitieron definir la fracción de interés (+1 -2 mm), en base al rendimiento en el tamizado (41%), la homogeneidad de dicha fracción y su capacidad de sorción (2g diesel/g BN). Los resultados obtenidos en los estudios de equilibrio de sorción fueron ajustados utilizando los modelos de isotermas de sorción Langmuir y Freundlich. La curva de ruptura se obtuvo mediante un sistema de flujo continuo (1 L/h) de agua oleosa a través de un lecho fijo de 59,997 g de BN. Los estudios realizados demostraron que el BN tiene potencialidades como biosorbente de hidrocarburos a la granulometría estudiada (+1 -2 mm).Para el análisis estadístico, se utilizó el software statgraphicscenturión XV.II. El punto de ruptura o quiebra, se observó a las 12 horas de operación, en las condiciones experimentales a escala de laboratorio. Se concluye que el biosorbente evaluado es efectivo en la remoción de los indicadores de la contaminación: grasas, aceites (98,5%) e hidrocarburos totales (94,8%)

Measuring the effective focal length and shape factor of a thick lens using a microscope

The optical power of a thick spherical lens and its Coddington shape factor are essential magnitudes that characterize its image quality. Here, we propose an experimental procedure and apparatus that allow accurate determination of those magnitudes for any spherical lens from geometrical measurements. The performance of the technique and the used instruments are simple since it only requires a microscope and an optical mouse. The propose overcomes the drawbacks of other devices that need of the refractive index or may damage the lens surfaces, like spherometers, and provides similar results to those from commercial lensmeters.Authors thank the University of Alicante for the funds (GITE-09003-UA). This work was supported by the “Vicerrectorado de Tecnología e Innovación Educativa” of the University of Alicante (Spain) and under the project GV/2013/009

Three-dimensional planar object tracking with sub-pixel accuracy

Subpixel techniques are commonly used to increase the spatial resolution in tracking tasks. Object tracking with targets of known shape permits obtaining information about object position and orientation in the three-dimensional space. A proper selection of the target shape allows us to determine its position inside a plane and its angular and azimuthal orientation under certain limits. Our proposal is demonstrated both numerical and experimentally and provides an increase the accuracy of more than one order of magnitude compared to the nominal resolution of the sensor. The experiment has been performed with a high-speed camera, which simultaneously provides high spatial and temporal resolution, so it may be interesting for some applications where this kind of targets can be attached, such as vibration monitoring and structural analysis.The authors acknowledge the support of the Spanish Ministerio de Economía y Competitividad through the project BIA2011-22704 and the Generalitat Valenciana through the projects GV/2013/009 and PROMETEO/ 2011/021. A. B. Roig acknowledges a grant from Cajamurcia

A high-resolution binocular video-oculography system: assessment of pupillary light reflex and detection of an early incomplete blink and an upward eye movement

Background: The pupillary light reflex characterizes the direct and consensual response of the eye to the perceived brightness of a stimulus. It has been used as indicator of both neurological and optic nerve pathologies. As with other eye reflexes, this reflex constitutes an almost instantaneous movement and is linked to activation of the same midbrain area. The latency of the pupillary light reflex is around 200 ms, although the literature also indicates that the fastest eye reflexes last 20 ms. Therefore, a system with sufficiently high spatial and temporal resolutions is required for accurate assessment. In this study, we analyzed the pupillary light reflex to determine whether any small discrepancy exists between the direct and consensual responses, and to ascertain whether any other eye reflex occurs before the pupillary light reflex. Methods: We constructed a binocular video-oculography system two high-speed cameras that simultaneously focused on both eyes. This was then employed to assess the direct and consensual responses of each eye using our own algorithm based on Circular Hough Transform to detect and track the pupil. Time parameters describing the pupillary light reflex were obtained from the radius time-variation. Eight healthy subjects (4 women, 4 men, aged 24–45) participated in this experiment. Results: Our system, which has a resolution of 15 microns and 4 ms, obtained time parameters describing the pupillary light reflex that were similar to those reported in previous studies, with no significant differences between direct and consensual reflexes. Moreover, it revealed an incomplete reflex blink and an upward eye movement at around 100 ms that may correspond to Bell’s phenomenon. Conclusions: Direct and consensual pupillary responses do not any significant temporal differences. The system and method described here could prove useful for further assessment of pupillary and blink reflexes. The resolution obtained revealed the existence reported here of an early incomplete blink and an upward eye movement.The authors acknowledge the support of the Spanish Ministerio de Economía y Competitividad through the project BIA2011-22704 and the Generalitat Valenciana through the projects GV/2013/009 and PROMETEO/2011/021. A. B. Roig acknowledges a grant from Cajamurcia

Improving kNN multi-label classification in Prototype Selection scenarios using class proposals

Prototype Selection (PS) algorithms allow a faster Nearest Neighbor classification by keeping only the most profitable prototypes of the training set. In turn, these schemes typically lower the performance accuracy. In this work a new strategy for multi-label classifications tasks is proposed to solve this accuracy drop without the need of using all the training set. For that, given a new instance, the PS algorithm is used as a fast recommender system which retrieves the most likely classes. Then, the actual classification is performed only considering the prototypes from the initial training set belonging to the suggested classes. Results show that this strategy provides a large set of trade-off solutions which fills the gap between PS-based classification efficiency and conventional kNN accuracy. Furthermore, this scheme is not only able to, at best, reach the performance of conventional kNN with barely a third of distances computed, but it does also outperform the latter in noisy scenarios, proving to be a much more robust approach.This work was partially supported by the Spanish Ministerio de Educación, Cultura y Deporte through FPU Fellowship (AP2012–0939), the Spanish Ministerio de Economía y Competitividad through Project TIMuL (TIN2013-48152-C2-1-R), Consejería de Educación de la Comunidad Valenciana through Project PROMETEO/2012/017 and Vicerrectorado de Investigación, Desarrollo e Innovación de la Universidad de Alicante through FPU Program (UAFPU2014–5883)

High-speed video-oculography applied to assess pupil light reflex

Póster presentado en el VII European/ I World Meeting in Visual and Physiological OpticsEye response to light exposure is usually described through the pupillary light reflex, which controls the pupil diameter and allows for testing the sensory and motor functions of the eye. We have arranged an experimental setup and developed a procedure in order to improve the video-oculography experiment through high-speed imaging. The technique has been applied over eleven people distinguishing between consensual and direct pupillary light reflexes and analyzing the eye dominance. We found no significant differences. Moreover, obtained time parameters describing the pupil light reflex agree with those from literature.The authors acknowledge the projects BIA2011-22704, GV/2013/009 and PROMETEO/ 2011/021. A. B. Roig acknowledges a grant from Cajamurcia