Obtención de gas de síntesis por tratamiento térmico en microondas de biomasa y biogás

En este trabajo se estudia la pirólisis, tanto en microondas como en horno eléctrico, de un residuo procedente de la industria del café, con objeto de comparar la influencia del calentamiento en las características de las fracciones resultantes. La alta proporción de gas de síntesis (H2 + CO) obtenida con el microondas (hasta del 73%) es debida al hecho que la auto-gasificación del carbonizado con el CO2 liberado y que la descomposición catalítica de CH4 se ven favorecidas por este tipo de calentamiento.Así, los experimentos de estas dos últimas reacciones llevadas a cabo de manera individual, con ambos sistemas de calentamiento, demuestran que se dan mayores conversiones en el microondas. En el caso de la descomposición de CH4, la conversión, que inicialmente alcanza valores próximos al 100%, experimentaun descenso importante al cabo de pocos minutos como consecuencia de la formación de depósitos de carbono que bloquean los centros activos de la superficie del catalizador. Sin embargo, una combinación de ambas reacciones, i.e. reformado de CH4 con CO2, mejora el proceso de conversión de CH4 a H2, debido a que el CO2 gasifica los depósitos de carbono generados, permitiendo una regeneración “in situ” del catalizador. Estos resultados han servido como punto de partida para el desarrollo de un nuevo procedimiento que permitiría convertir biogás en gas de síntesis

The Influence of Carbon Coatings on the Functional Properties of X39Cr13 and 316LVM Steels Intended for Biomedical Applications

[EN] Carbon coatings are used in many different industrial areas, for example in cutting, electronics, or medical applications. On the one hand, carbon coatings have improved the functional properties of medical products because of their high biotolerance, which makes them an important material for implant coatings. On the other hand, high rigidity and abrasion resistance are properties needed in case of surgical tools. Thus, the aim of this research was to study the influence of mechanical abrasion by tumbling and chemical passivation on carbon coatings deposited by reactive magnetron sputtering (RMS) and radio frequency plasma activated chemical vapor deposition (RF PACVD) of X39Cr13 (mainly used for surgical tools) and 316LVM (mainly used for implants). Functional properties, such as roughness, coatings adhesion (scratch test), and wettability were investigated. As a result, DLC coatings applied by magnetron sputtering were found to be the optimum surface treatment in terms of adhesion and wettability properties, being more appropriate for the use of X39Cr13 base than 316LVM for carbon layer deposition.S

The Determinants of the Preferred Walking Speed in Individuals with Obesity.

The preferred walking speed (PWS), also known as the "spontaneous" or "self-selected" walking speed, is the speed normally used during daily living activities and may represent an appropriate exercise intensity for weight reduction programs aiming to enhance a more negative energy balance. The aim of this study was to examine, simultaneously, the energetics, mechanics, and perceived exertion determinants of PWS in individuals with obesity. Twenty-three adults with obesity (age 32.7 ± 6.8 years, body mass index 33.6 ± 2.6 kg/m2) were recruited. The participants performed 10 min of treadmill familiarization, and PWS was determined. Each subject performed six 5-min walking trials (PWS 0.56, 0.83, 1.11, 1.39, and 1.67 m/s). Gas exchanges were collected and analyzed to obtain the gross energy cost of walking (GCw), rated perceived exertion (RPE) was measured using a 6-20 Borg scale, and the external mechanical work (Wext) and the fraction of mechanical energy recovered by the pendular mechanism (Recovery) were computed using an instrumented treadmill. Second-order least-squares regression was used to calculate the optimal walking speed (OWS) of each variable. No significant difference was found between PWS (1.28 ± 0.13 m/s) and OWS for GCw (1.28 ± 0.10 m/s), RPE cost of walking (1.38 ± 0.14 m/s), and Recovery (1.48 ± 0.27 m/s; p > 0.06 for all), but the PWS was significantly faster than the OWS for Wext (0.98 ± 0.56 m/s; p < 0.02). Multiple regression (r = 0.72; p = 0.003) showed that ∼52% of the variance in PWS was explained by Recovery, Wext, and height. The main finding of this study was that obese adults may select their PWS in function of several competing demands, since this speed simultaneously minimizes pendular energy transduction, energy cost, and perceived exertion during walking. Moreover, recovery of mechanical work, external work, and height seem to be the major determinants of PWS in these individuals

A Proposal for a Modified Moller-Plesset Perturbation Theory

A modified version of the Moller-Plesset approach for obtaining the correlation energy associated to a Hartree-Fock ground state is proposed. The method is tested in a model of interacting fermions that allows for an exact solution. Using up to third order terms improved results are obtained, even more accurate in the limit of loosely bound particles. This result suggests the possible convenience of the scheme for the study of chemical bound problems.Comment: 10 pages, 1 figur

Minorías y medios de comunicación: código deontológico

Editores: Fernando M. Mariño Menéndez y Carlos R. Fernández LiesaContiene: Prólogo / Fernando M. Mariño Menéndez. -- Código deontológico de trato a las minorías en los medios de comunicación. -- Los códigos de conducta y el tratamiento a las minorías en los medios / Antonio Petit Caro. -- Códigos de conducta y trato a las minorías en los medios de comunicación / José A. Sorolla. -- Tratamiento de las minorías en los informativos de TV / Vicente Romero. -- Las minorías y los medios de comunicación: régimen jurídico y propuestas para la elaboración de un código deontológico / Carlos R. Fernández Liesa

Tumor en hueco poplíteo en 1 niño: diagnóstico diferencial a propósito de 1 caso

Se presenta 1 caso de tumoración en hueco poplíteo en 1 paciente de 15 años de edad. En la exploración clínica inicial encontramos una tumoración de consistencia dura sin signos inflamatorios. Los estudios con RNM y gammagrafía ósea nos orientaban hacia una patología benigna. El estudio anatomopatológico realizado tras la exéresis de la tumoración lo caracterizó como zona de necrosis isquémica con calcificación distrófica de la inserción muscular del tendón del músculo semitendinoso.A 15-year-old boy with a poplited tumor in the knee is presented. The initial exploration showed a firm mass without inflammatory signs. RNM and bone scintigraphy disclosed benign pathology. The pathological diagnosis showed a central area of isquemic necrosis, with distrofic calcification of the semitendinous muscle

The Iberian Massif of western Asturias and Lugo: a record of landscape forming processes during 107 time-scales.

El relieve transitorio del occidente Asturiano y Lugo, desarrollado sobre rocas del Macizo Ibérico, contiene información sobre los procesos pasados y recientes que condicionan la topográfica. Un análisis geomorfológico, basado en el uso de Sistemas de Información Geográfica, combinado con técnicas de termocronología de baja temperatura y de análisis de isótopos cosmogénicos, ha permitido identificar varios componentes del paisaje con edades y significados geodinámicos diferentes. Estos son: 1) paleosuperficies de bajo relieve con bajas tasas de denudación, interpretadas como relictos de un periodo entre los 100 y 45 Ma en que se desarrollaron relieves maduros; 2) pequeños ríos costeros que presentan tasas de denudación moderadas asociadas a una lenta elevación del terreno durante el Neógeno; 3) una ancha superficie de abrasión submarina, elevada lentamente (0.07-0.15 mm/a) sobre el nivel del mar desde hace 1.5 Ma. Las rocas de esta región registran tasas de exhumación más altas antes del Cretácico Superior, durante la extensión Mesozoica en el Atlántico y Golfo de Vizcaya. Las tasas de exhumación se redujeron durante el periodo de relativa estabilidad tectónica iniciado después de la ruptura continental en el Cretácico Inferior. El sistema de denudación ha permanecido poco eficiente durante la elevación topográfica iniciada en el Eoceno.Estos estudios han sido financiados a través de los proyectos BTE2002-00330, CGL2005-24204 y CGL2007-60230/BTE de los Ministerios de Educación y Ciencia y de Ciencia e Innovación. Se incluyen en el marco del proyecto “TOPO-Iberia”, Consolider-Ingenio 2010, CSD2006-00041.Peer Reviewe

Multi sensor system for pedestrian tracking and activity recognition in indoor environments

The widespread use of mobile devices and the rise of Global Navigation Satellite Systems (GNSS) have allowed mobile tracking applications to become very popular and valuable in outdoor environments. However, tracking pedestrians in indoor environments with Global Positioning System (GPS)-based schemes is still very challenging. Along with indoor tracking, the ability to recognize pedestrian behavior and activities can lead to considerable growth in location-based applications including pervasive healthcare, leisure and guide services (such as, hospitals, museums, airports, etc.), and emergency services, among the most important ones. This paper presents a system for pedestrian tracking and activity recognition in indoor environments using exclusively common off-the-shelf sensors embedded in smartphones (accelerometer, gyroscope, magnetometer and barometer). The proposed system combines the knowledge found in biomechanical patterns of the human body while accomplishing basic activities, such as walking or climbing stairs up and down, along with identifiable signatures that certain indoor locations (such as turns or elevators) introduce on sensing data. The system was implemented and tested on Android-based mobile phones. The system detects and counts steps with an accuracy of 97% and 96:67% in flat floor and stairs, respectively; detects user changes of direction and altitude with 98:88% and 96:66% accuracy, respectively; and recognizes the proposed human activities with a 95% accuracy. All modules combined lead to a total tracking accuracy of 91:06% in common human motion indoor displacement