Keeping watch over Colombia’s slumbering volcanoes

The Volcanological and Seismological Observatories of Manizales, Pasto and Popayan (Colombian Geological Survey) monitor and study the active volcanoes of Colombia using seismological, geodetic, geochemical and other techniques. Since 2009, permanent GNSS stations have been installed to complement classical geodetic measurements (e.g., tilt, EDM). At the moment, there are a total of 20 GNSS stations installed at Nevado del Ruiz, Cerro Machín, Puracé and Galeras volcanoes. Nevado del Ruiz has remained the most dynamic of the active Colombian volcanoes since its tragic eruption of 13 November 1985. The most significant deformation occurred between 2007 and 2012, when inflation, associated with magma migration and several small to moderate explosive eruptions in 2012 (VEI less or equal to 3), was observed. Galeras has experienced more than 25 moderate Vulcanian eruptions (VEI less or equal to 3) since 1989. In particular, the deformation network detected significant signals associated with magma migration and the extrusion of lava domes in 1991, 2005, 2008 and 2012. Puracé volcano has been the site of more than 10 minor eruptive episodes (VEI=2) in the past century, most recently in 1977. Monitoring of this volcano started in 1994. Unrest at Puracé since that time has been characterized by significant increases in seismic activity but with little or no deformation. We employ GAMIT/GLOBK to process GPS data from the monitoring network with support from the Volcano Disaster Assistance Program (U.S. Geological Survey). Additionally, differential processing is carried out using the commercial package Trimble 4D Control. Preliminary results for 2012 show no significant deformation at Puracé and Galeras volcanoes. On the other hand, the time series from Nevado del Ruiz shows a minor inflation (2-4 cm/yr) associated with the eruptive activity of 2012

Quantitative analysis of numerical estimates for the permeability of porous media from lattice-Boltzmann simulations

During the last decade, lattice-Boltzmann (LB) simulations have been improved to become an efficient tool for determining the permeability of porous media samples. However, well known improvements of the original algorithm are often not implemented. These include for example multirelaxation time schemes or improved boundary conditions, as well as different possibilities to impose a pressure gradient. This paper shows that a significant difference of the calculated permeabilities can be found unless one uses a carefully selected setup. We present a detailed discussion of possible simulation setups and quantitative studies of the influence of simulation parameters. We illustrate our results by applying the algorithm to a Fontainebleau sandstone and by comparing our benchmark studies to other numerical permeability measurements in the literature.Comment: 14 pages, 11 figure

Changes in volatile compounds of pork loin (fresh and marinated) with different irradiation and packaging during storage

The analysis of volatile compounds by gas chromatography- mass spectrometry after extraction by purge and trap has been used to investigate the volatile compounds of fresh and marinated pork loin after E-beam treatmet as a function of packaging type (air, vacuum and modified atmosphere), radiation dose (1 and 2 kGy) and storage temperature (4 and 8 °C). Major differences were found between fresh and marinated samples but, in general, only minor differences were found in the volatile compounds of both types of loin due to storage temperature, packaging method and doses of irradiation. It is concluded that the application of E-beam is a very useful way to extend the shelflife of fresh and marinated pork loin with no changes in the odor of the products.<br><br>Se ha utilizado la cromatografía de gases/espectrometría de masas, la extracción mediante purga y trampa para estudiar los compuestos volátiles de lomo de cerdo fresco y adobado, tratados con electrones acelerados (1 y 2 kGy) y almacenado en refrigeración (4 y 8 °C) bajo diferentes atmósferas (aire, vacío y atmósfera modificada). Se observaron diferencias importantes entre las muestras de lomo fresco y adobado pero, en general, solo pequeñas diferencias fueron observadas en algunos compuestos volátiles de ambos tipos de lomo debidas al efecto de la temperatura, tiempo de almacenamiento, tipo de atmósfera o dosis de radiación. Se ha concluido que la aplicación de electrones acelerados es una tecnología muy eficaz para ampliar la vida útil del lomo de cerdo fresco y adobado sin que se detecten cambios en el olor de los productos

USE OF SYNTHETIC TANINES DURING THE SKIN CURTITION PROCESS OF Cavia porcellus (CUY) IN FINE PELETERY

The Cavia porcellus skin (Cuy), after receiving a tanning process, using synthetic tannins, becomes a high quality leather, very suitable in the articles manufacture of high quality. Its main objective was the evaluation of different levels of synthetic tannin (6, 7, 8%) during the tanning process of guinea pig skins with hair; using 48 skins, with an average mass of 200 g each. The experimental units modeled with a Completely Random Design (DCA. Once the experimental phase was completed, it observed that the most skin tanning suitable level the guinea pig (retaining hair) is 6 % of synthetic tanning agent; it´s supported by the excellent results the tests performed. The physical resistance evaluation determined that the best tensile strength (1945.75 N/cm2) it´s reached whit 6 % of synthetic tannin and the best percentage of elongation (89.69 %) achieved with the use of 7 % of tannin (which fully meet the requirements quality the Spanish Leather Association). The most efficient sensorial characteristics obtained with 6 % of tannin: fullness 4.88; softness 4.63 and roundness 4.75 points, respectively; producing a very soft, flexible skin and above all with the fullness suitable for the fine articles manufacture. Keywords: tanning, skins, guinea pig, synthetic tannins. Resumen La piel del Cavia porcellus (Cuy), después de curtida, empleando taninos sintéticos, se convierte en un cuero de alta calidad, muy adecuado en la peletería fina. Esta investigación tuvo por objetivo fundamental la evaluación de diferentes niveles de tanino sintético (6, 7, 8 %) durante el proceso de curtición de pieles de cuyes con pelo; utilizando para ello un total de 48 pieles, con una masa promedio de 200 g cada una. Las unidades experimentales fueron modeladas con un Diseño Completamente al Azar (DCA). Una vez culminada la fase experimental, se pudo constatar que el nivel más adecuado para la curtición de la piel de cuy (conservando el pelo) es del 6 % de curtiente sintético; lo cual quedó avalado por los excelentes resultados de las pruebas practicadas. La evaluación de las resistencias físicas determinó que la mejor resistencia a la tensión (1945,75 N/cm2) se alcanzó al curtir con 6 % de tanino sintético, y el mejor porcentaje de elongación (89,69 %), se logró con la utilización de 7 % de tanino (que satisfacen completamente con las exigencias de calidad de la Asociación Española del Cuero). Las características sensoriales más eficientes fueron logradas al curtir las pieles con 6 % de tanino: llenura 4,88; blandura 4,63 y redondez 4,75 puntos, respectivamente; produciéndose una piel muy suave, flexible y sobre todo con la llenura adecuada para la confección de artículos de peletería fina. Palabras Clave: Clave: curtición, pieles, cuy, taninos sintéticos

Spatial and temporal analysis of the seasonal and interannual variability in the tropical Pacific simulated with a coupled GCM

In the first part of this work, the dominant time scales that explain the tropical variability of the first SINTEX simulation (ECHAM4(T30)-ORCA) are identified through a spectral analysis. Higher order spectral analysis is used to examine the interactions among these time scales. The time series analyzed are an average of sea surface temperature over the Niño3 region. The time scales obtained are compared with those identified in another coupled GCM simulation (ECHAM4(T42)-OPYC3). The higher importance of the biannual time scale in this last is explained partly by the strength of the coupling between the annual and the biannual time scales. There is no such strong coupling in the SINTEX simulation. Important differences among the generation of the simulated warm (or cold) event suggest the need of a systematic classification to isolate their relevant features. Therefore in the second part of this work, we address this problem. A space-time cluster analysis is performed on a data set built by collecting the values of the heat content anomalies in the tropical Pacific region, in the fifteen months previous to a peak in the Niño3 Index that has been identified as a ‘warm’ (or ‘cold’) event. In the case of the warm events, three types of generation schemes are found. In two of them, there are anomalies of heat content in the west, north and south of the equator, more than nine months before the events start. In the third case, the anomalies appear and grow in the central equatorial Pacific. Only two types are needed to classify the generation of cold events. Negative sea level height anomalies appear six months before the Niño3 Index reaches the (local) minimum. They are located north of the equator in one of the groups, and south of it in the other. Some of these characteristic traits also appear in observations of warm and cold events

Programación de rutas para patrullas con tiempos de servicios variables mediante una meta-heurística híbrida

El patrullaje de policías es una de las mejores prácticas preventivas para la seguridad pública contra los delitos urbanos. En este trabajo se aborda el problema de planificar rutas de patrullas para minimizar el riesgo criminal de una zona teniendo en cuenta tiempos mínimos de viaje.  El problema se plantea a través de un modelo de programación lineal entero-mixto, bajo limitaciones de tiempo, costo y recursos. La formulación es una modificación del VRPSTW(1) con la propuesta de la modelación del riesgo y tiempos de servicios variables.  Se propone un algoritmo meta-heurísticos híbrido que combina GA(2), ACO(3) y búsqueda exhaustiva para ofrecer soluciones efectivas al problema.  Se propone una metodología multicriterio para la definición de índices criminales que permiten marcar prioridades en la generación de rutas de patrullas. Para validar el desempeño del enfoque propuesto, se realiza un caso de aplicación en Barranquilla (Colombia).MaestríaMagister en Ingeniería Industria

Ibn Arabí y el Mancebo de Arévalo: sus perspectivas en torno a la mujer sabia

This article makes a journey from the twelfth to the sixteenth century to contrast the perspective of Ibn Arabí and the Mancebo de Arévalo around the wise woman in Al Ándalus. In the case of Ibn Arabí (Twelfth century) his expressions of Shams Umm al-Fuqarâ and Mûnah Fâtima bint b. al-Muthannâ are analyzed in his book titled Los sufíes de Andalucía. Meanwhile, in the case of the Mancebo de Arévalo (Sixteenth cen-tury) his expressions on the Mora de Úbeda and Nozaita Kalderán are analyzed in his book titled Tafsira. Both cases provide different views around the wise woman that show the work of these women at certain times in Al Ándalus.El presente artículo hace un recorrido del siglo XII al siglo XVI para contrastar la perspectiva de Ibn Arabí y el Mancebo de Arévalo en torno a la mujer sabia en Al Ándalus. En el caso de Ibn Arabí (siglo XII) se analiza sus expresiones sobre Shams Umm al-Fuqarâ y Mûnah Fâtima bint b. al-Muthannâ en su libro titulado Los sufíes de Andalucía. Mientras, que en el caso del Mancebo de Arévalo (Siglo XVI) se analizan sus expresiones sobre la Mora de Úbeda y Nozaita Kalderán en su libro titulado Tafsira. Ambos casos son diferentes miradas en torno a la mujer sabia que evidencian la labor de estas mujeres en determinadas épocas en Al Ándalus

Development and implementation of technologies for physical telerehabilitation in Latin America:

La telerehabilitation ha surgido debido a la inclusión de tecnologías emergentes para la captura, transmisión, análisis y visualización de patrones de movimiento asociados a pacientes con trastornos músculo-esqueléticos. Esta estrategia permite llevar a cabo procesos de diagnóstico y tratamientos de rehabilitación a distancia. Este artículo presenta una revisión sistemática del desarrollo e implementación actual de las tecnologías de telerehabilitación en la región latinoamericana. El objetivo principal es explorar, a partir de la literatura científica reportada y fuentes divulgativas, si las tecnologías de telerehabilitación han logrado ser introducidas en esta región. Asimismo, este trabajo revela los prototipos actuales o sistemas que están en desarrollo o que ya están siendo usados. Se llevó a cabo una revisión sistemática, mediante dos búsquedas diferentes. La primera implicó una búsqueda bibliográfica rigurosa en los repositorios digitales científicos más relevantes en el área y la segunda incluyó proyectos y programas de telerehabilitación implementados en la región, encontrados a partir de una búsqueda avanzada en Google. Se encontró un total de 53 documentos de seis países (Colombia, Brasil, México, Ecuador, Chile y Argentina); la mayoría de ellos estaban enfocados en iniciativas académicas y de investigación para el desarrollo de prototipos tecnológicos para telerehabilitación de pacientes pediátricos y adultos mayores, afectados por deficiencias motoras o funcionales, parálisis cerebral, enfermedades neurocognitivas y accidente cerebrovascular. El análisis de estos documentos reveló la necesidad de un extenso enfoque integrado de salud y sistema social para aumentar la disponibilidad actual de iniciativas de telerehabilitación en la región latinoamericana.Telerehabilitation has arised by the inclusion of emerging technologies for capturing, transmitting, analyzing and visualizing movement patterns associated to musculoskeletal disorders. This therapeutic strategy enables to carry out diagnosis processes and provide rehabilitation treatments. This paper presents a systematic review of the current development and implementation of telerehabilitation technologies in Latin America. The main goal is to explore the scientific literature and dissemination sources to establish if such technologies have been introduced in this region. Likewise, this work highlights existing prototypes or systems that are to being used or that are still under development. A systematic search strategy was conducted by two different searches: the first one involves a rigorous literature search from the most relevant scientific digital repositories; the second one included telerehabilitation projects and programs retrieved by an advanced Google search. A total of 53 documents from six countries (Colombia, Brazil, Mexico, Ecuador, Chile and Argentina) were found. Most of them were focused on academic and research initiatives to develop in-home telerehabilitation technologies for pediatric and elderly populations affected by motor and functional impairment, cerebral palsy, neurocognitive disorders and stroke. The analysis of the findings revealed the need for a comprehensive approach that integrates health care and the social system to increase the current availability of telerehabilitation initiatives in Latin America

Tailoring Organic-Organic Poly(vinylpyrrolidone) Microparticles and Fibers with Multiwalled Carbon Nanotubes for Reinforced Composites

Polymeric-based microparticles and fibers are tailorable for a wide range of common industrial and biomedical applications, while multiwalled carbon nanotubes (MWCNTs) are among the most useful macromolecules based on their outstanding electronic, mechanical, and optical properties at the nanoscale. If one combines these nanostructures with various polymeric precursors, their range of potential applications becomes even greater. One of the simplest and most affordable methods for fabricating micro- and nanostructures is electrospinning. Herein we demonstrate how MWCNTs may be used to produce tailor-made organic-organic poly(vinylpyrrolidone) (PVP) microparticles and fibers via electrospinning by studying their structural, vibrational, rheological, and mechanical properties' dependence on their solvent (ethanol (EtOH) or dimethylformamide (DMF)) and resulting morphology. Specifically, we find clear differences in morphologies from perfectly spherical and isolated microparticles to fibers mats, or a combination of fibers with entangled beads, with solvent type and concentration. On the basis of our findings, we propose that the mechanism governing the shape and size of the particles is a competition between the solvent's surface tension, dielectric constant, and viscoelastic properties. We show, based on both our experimental results and density functional theory (DFT) calculations, that OH functionalization of the MWCNTs is essential for achieving high PVP coverages and promoting the stability of the resulting PVP/MWCNT nanocomposite. Finally, by fabricating PVP/MWCNT fiber mats, we demonstrate that low concentrations (0.01-0.1 wt %) of MWCNTs led to a qualitative improvement (â250%) in the resulting mechanical properties, i.e., a reinforced composite. These results show how by controlling the solvent's dielectric constant, surface tension, and polymer concentration, one may produce tailor-made polymeric nanomaterials in combination with other organic/inorganic nanoparticles, i.e., silver, gold, or carbon allotropes, for next-generation applications