Magnetic and FMR study on CoFe₂O₄/ZnFe₂O₄ bilayers

CoFe<sub>2</sub>O<sub>4</sub>/ZnFe<sub>2</sub>O<sub>4</sub> bilayers were deposited by the pulsed laser deposition on amorphous fused quartz substrate at substrate temperature of 350°C and in oxygen pressure of 0.16 mbar. The films were studied after ex-situ annealing for 2 h in air at various temperatures up to 650°C. The magnetic properties of the bilayers were studied at 300 K and at 10 K. Ferromagnetic resonance was carried out at x-band frequencies at room temperature. It was found that as a result of annealing, the diffusion between Co ferrite and Zn ferrite starts around 350°C and leads to a large line width system having magnetization, which remains undetected by Ferromagnetic resonance

Optimización de un pretratamiento enzimático para semillas de mostaza utilizando metodología de superficie de respuesta

In order to investigate the effect of an enzymatic pre-treatment process for the extraction of oil from black mustard seeds (Brassica nigra) using viscozyme, the reaction parameters such as temperature, buffer-to-seed ratio and enzyme concentration were considered as determinant factors in the central composite design. Optimization was carried out according to the four-variable five-level central composite design of experiments. The effects of enzyme concentration (5–12%), temperature (40–55 °C), pH (5.0–6.0), and reaction time (1–7 h) on the free oil liberated were studied. Residual oil was collected by subjecting the treated meal to soxhlet extraction for 4 h. An enzyme dose of 7.5% (w/w), pH 5.0, 50 °C, and 5 h with constant shaking at 450 rpm were found to be opti­mal conditions. Centrifuging the mixture at 7000 rpm for 30 min separated the oil with a recovery of 71–73.1%.Con el fin de investigar el efecto de un pretratamiento enzimático para la extracción de aceite de semillas de mostaza negra (Brassica nigra) utilizando viscozima, los parámetros de la reacción, como la temperatura, la relación de tampón/semilla y las concentraciones de enzima, se consideraron factores deter­minantes en el diseño. La optimización se llevó a cabo mediante cuatro diseños de experimentos compuestos de cinco niveles. Se estudió el efecto de la concentración de enzima (5-12%), temperatura (40-55 °C), pH (5.0-6.0), y tiempo de reacción (1-7 h) sobre el aceite liberado. El aceite residual se recolectó sometiendo la pasta tratada a una extracción de soxhlet durante 4 h. Las dosis de enzima del 7,5% (p/p), pH 5,0, 50 °C y 5 h con agitación constante a 450 rpm fueron las condiciones óptimas. La centrifugación de la mezcla a 7000 rpm durante 30 minutos separó el aceite con una recuperación de 71-73.1%

Modificación enzimática de fosfatidilcolina con n-3 PUFA a partir de ácidos grasos de aceites de gusanos de seda

α-Linolenic acid (ALA) containing phosphatidylcholine (PC) was prepared by an enzymatic method employing natural substrates comprising of egg and eri silkworm oil. Eri silkworm oil extracted from eri pupae was saponified to obtain the fatty acid mixture which was further subjected to urea complexation to obtain an ALA rich fraction with a purity of about 93%. Transesterification of PC with the ALA rich fraction with three immobilized lipases namely Lipozyme TL IM, Lipozyme RM IM and lipase from Candida Antarcticaz showed that only the lipase from Candida antarctica was successful for the incorporation of ALA into egg yolk PC. It was found that ALA was incorporated by up to 27% in the sn-1 position of egg PC and the positional distribution analysis of fatty acids in the modified PC showed that the sn-1 position was found to contain about 59% ALA.El ácido α-linolénico (ALA) contenido en fosfatidilcolina (PC) se preparó mediante un método enzimático empleando sustratos naturales que comprenden huevo y aceite de gusanos de seda. El aceite extraído de las crisálidas de gusanos de seda se saponificó para obtener la mezcla de ácidos grasos que se sometió a complejación con urea para obtener la fracción rica en ALA, con una pureza aproximadamente del 93%. La transesterificación de PC con fracción rica en ALA con tres lipasas inmovilizadas, Lipozyme TL IM, Lipozyme RM IM y lipasa de Candida antárctica, mostró que sólo la lipasa de Candida antarctica tuvo éxito en la incorporación de ALA en PC de yema de huevo. Se encontró que el ALA fue incorporado hasta 27% en la posición sn-1 de PC de huevo y el análisis de la distribución de los ácidos grasos en PC modificado mostró que la posición sn-1 que contenía aproximadamente 59% de ALA

Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Observation of the baryonic decay B \uaf 0 \u2192 \u39bc+ p \uaf K-K+

We report the observation of the baryonic decay B\uaf0\u2192\u39bc+p\uafK-K+ using a data sample of 471 7106 BB\uaf pairs produced in e+e- annihilations at s=10.58GeV. This data sample was recorded with the BABAR detector at the PEP-II storage ring at SLAC. We find B(B\uaf0\u2192\u39bc+p\uafK-K+)=(2.5\ub10.4(stat)\ub10.2(syst)\ub10.6B(\u39bc+)) 710-5, where the uncertainties are statistical, systematic, and due to the uncertainty of the \u39bc+\u2192pK-\u3c0+ branching fraction, respectively. The result has a significance corresponding to 5.0 standard deviations, including all uncertainties. For the resonant decay B\uaf0\u2192\u39bc+p\uaf\u3c6, we determine the upper limit B(B\uaf0\u2192\u39bc+p\uaf\u3c6)<1.2 710-5 at 90% confidence level

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011