Correlation between magnetic interactions and domain structure in A1 FePt ferromagnetic thin films

We have investigated the relationship between the domain structure and the magnetic interactions in a series of FePt ferromagnetic thin films of varying thickness. As-made films grow in the magnetically soft and chemically disordered A1 phase that may have two distinct domain structures. Above a critical thickness $d_{cr}\sim 30$ nm the presence of an out of plane anisotropy induces the formation of stripes, while for $d<d_{cr}$ planar domains occur. Magnetic interactions have been characterized using the well known DCD-IRM remanence protocols, $\delta M$ plots, and magnetic viscosity measurements. We have observed a strong correlation between the domain configuration and the sign of the magnetic interactions. Planar domains are associated with positive exchange-like interactions, while stripe domains have a strong negative dipolar-like contribution. In this last case we have found a close correlation between the interaction parameter and the surface dipolar energy of the stripe domain structure. Using time dependent magnetic viscosity measurements, we have also estimated an average activation volume for magnetic reversal, $\langle V_{ac}\rangle \sim 1.37\times 10^{4}$ nm$^{3},$ which is approximately independent of the film thickness or the stripe period.Comment: 25 pages, 11 figure

Microbiological and structural aspects of granular sludge from autotrophic denitrifying reactors.

Denitrification is applied in the tertiary treatment of wastewater to reduce N-pollutants. Fluorescence in situ hybridisation (FISH), CARD (catalyzed reporter deposition)-FISH, cloning, and scanning electron microscopy (SEM) were applied to follow the evolution of the microbial composition and structure of granular sludge in autotrophic denitrifying bioreactors fed with nitrate and thiosulfate. With this goal, FISH oligonucleotide probes for the autotrophic denitrifiers, Thiobacillus denitrificans and Thiomicrospira denitrificans, were designed and their utility tested. CARD-FISH and cloning data showed that bacterial diversity changed with bioreactor operation time. After 110 days of operation, the abundance of Thiobacillus denitrificans cells increased considerably: from 1 to 35% of total DAPI-stained cells and from no isolated clones to 30% of the total positives clones. This fact strongly suggests that this microorganism played a dominant role in the autotrophic denitrification. The Archaeal diversity remained almost unchanged and it was mainly represented by Methanosaeta soehngenii. Scanning electron microscopy results indicated a considerable loss in the integrity of the sludge granules during the operation, with risk of sludge buoyancy.pre-print370 K

Gas-phase hydrodechlorination of mixtures of chloromethanes with activated carbon-supported platinum catalysts

Platinum catalysts supported on activated carbon (Pt/C) at different metal loadings (0.5-2% Pt) have been tested in the gas-phase hydrodechlorination (HDC) of mixtures of dichloromethane (DCM) and chloroform (TCM), with a total feed concentration of 1000ppmv. Almost complete dechlorination was achieved at 250°C, 1kghmol-1 space time and a H2/CM molar ratio of 25 with the 2% Pt catalyst. At a reaction temperature of 250°C, scarce inhibition in the conversion of both compounds was observed compared to the HDC of the individual chloromethanes. The TOF values for DCM increase with the Pt content, which can be attributed to the higher proportion of the zero-valent species. The selectivity to reaction products suggests a parallel reactions scheme. The catalysts showed a high stability, demonstrated by the unchanged conversion of both chloromethanes upon time on stream in long-term experiments carried out at up to 26h.The authors gratefully acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) through the project CTM2011-2835

Supporting autonomy in physical education: Perception versus reality.

Esta investigación se centró, por una parte en la percepción de apoyo a la autonomía en las clases de Educación física, que tienen tanto el alumnado como el profesorado, y por otra, en la coherencia entre percepción y la realidad observada en las clases. Se aplicaron dos escalas al profesorado y al alumnado con el objeto de conocer con qué frecuencia se producen comportamientos instructivos favorables al desarrollo de la autonomía, y se observaron y grabaron en video clases impartidas por el profesorado. Los resultados muestran que la frecuencia de los comportamientos instructivos de apoyo a la autonomía durante la intervención de enseñanza es significativamente menor que la percibida por el alumnado y el profesorado. La realidad observada muestra un perfil de profesorado con gran margen de mejora en comportamientos como: calidad de la comunicación, funcionalidad de las tareas, fomento del pensamiento del alumnado, situaciones en las que el alumnado pueda expresar su opinión sobre las tareas y motivación intrínsecaThis investigation, on the one hand it focuses on students´ and teachers´ perception about autonomy support during Physical Education instruction, and on the other hand, in the coherence between perception and reality observed in the classes. Two scales were administered to determine the frequency of instructional behaviors favoring the development of autonomy, and teacher´s classes were observed and videotaped. The results show that the observed frequency of instructional behavior favoring autonomy support during classes is significantly lower than that perceived by students and teachers. The observed reality reveals a teacher profile with room for improvement in behaviors such as: communication quality, task functionality, promotion of students’ thinking, creation of situations in which students can express their opinions of the tasks, and increasing intrinsic motivationEl presente artículo forma parte del estudio realizado con la financiación del proyecto SEJ2007-672687/EDU del Ministerio de Ciencia e Innovació

Recurrence of the blue wing enhancements in the high ionization lines of SDSS 1004+4112 A

We present integral field spectroscopic observations of the quadruple-lensed QSO SDSS 1004+4112 taken with the fiber system INTEGRAL at the William Herschel Telescope on 2004 January 19. In May 2003 a blueward enhancement in the high ionization lines of SDSS 1004+4112A was detected and then faded. Our observations are the first to note a second event of similar characteristics less than one year after. Although initially attributed to microlensing, the resemblance among the spectra of both events and the absence of microlensing-induced changes in the continuum of component A are puzzling. The lack of a convincing explanation under the microlensing or intrinsic variability hypotheses makes the observed enhancements particularly relevant, calling for close monitoring of this object.Comment: 4 pages, 5 figure

Aceite de almendra virgen: Métodos de extracción y composición

In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.En este trabajo se revisan los métodos de extracción del aceite de almendra virgen y su composición química. Los métodos más habituales para la obtención del aceite son la extracción con disolventes, la extracción con fluidos supercríticos (CO2) y los sistemas de presión (prensas hidráulica y de tornillo). El mayor rendimiento industrial, pero también la peor calidad de los aceites, se consigue mediante el uso de disolventes. Además, los aceites obtenidos por este método no se pueden considerar vírgenes, pues se obtienen por medio de tratamientos químicos. La extracción con fluidos supercríticos da lugar a aceites de mayor calidad pero a un precio muy elevado. La extracción mediante prensado se convierte en la mejor opción de extracción, al conseguir aceites de alta calidad a un precio asequible. En cuanto a su composición química, el aceite de almendra se caracteriza por su bajo contenido en ácidos grasos saturados y el predominio de los monoinsaturados, en especial en ácido oleico. Además, el aceite de almendra contiene compuestos bioactivos liposolubles y antioxidantes que lo convierten en un aceite con interesantes propiedades nutricionales y cosméticas

Comparisons of Production Costs and Profit of Three Different Technology Levels of Papaya Production in Tabasco, Mexico

The survey was carried out from September 2006 to January 2007 in three papaya production sites located in main papaya production zones in Tabasco; SE Mexico. There are differences in size of the cultivated area, in the yield of the papaya as well as in production costs and profit, according to the different technology levels in the farming systems: low, medium and high technology cultivation level. The financial evaluations were carried out in three sites with different productive technologies. The comparison of the agronomic and economic traits results for low technology level in: V AN of 2359.00 USD, BCR in 1.9 and an equilibrium point of 3750.00 USD, TIR of 0.25. In order to avoid loses, a quantity of 10714 kg papaya should be sold. In medium technology VAN is 1605.10 USD, BCR is 1.7, TIR 0.20 and the equilibrium point is 12800.00 USD. 36571 kg of papaya should be yearly sold. In high technology level VAN is 11749.40, BCR is 2.73, TIR 0.43 and the equilibrium point is 12187.50 USD, 34821 kg papaya should be sold yearly. The indicators showed that all three levels are profitable and economically viable

Analysis of short-period internal waves using wave-induced surface displacement: A three-dimensional model approach in Algeciras Bay and the Strait of Gibraltar

A three-dimensional, nonlinear, high-resolution, sigma coordinate, hydrodynamic model was applied to study the sea surface manifestation of short-period internal waves measured in Algeciras Bay and the Strait of Gibraltar. Model results reproduce the tidally induced generation of the internal bore over the Camarinal Sill and its disintegration into wave trains as it moves eastward. While propagating along the Strait of Gibraltar toward the Mediterranean Sea, the wave trains partly penetrate into Algeciras Bay, with typical oscillation periods of 20 and 40 min. The modeled wave-induced surface train structures are compared with satellite images and in situ observational data obtained from two pressure sensors located inside the bay. Results demonstrate that wave-induced sea surface displacements are indicators of the presence of internal waves and may be used in the context of the internal wave analysis when surface oscillations are captured with sufficient precision