Interplay between the magnetic anisotropy contributions of Cobalt nanowires

We report on the magnetic properties and the crystallographic structure of the cobalt nanowire arrays as a function of their nanoscale dimensions. X-ray diffraction measurements show the appearance of an in-plane HCP-Co phase for nanowires with 50 nm diameter, suggesting a partial reorientation of the magnetocrystalline anisotropy axis along the membrane plane with increasing pore diameter. No significant changes in the magnetic behavior of the nanowire system are observed with decreasing temperature, indicating that the effective magnetoelastic anisotropy does not play a dominant role in the remagnetization processes of individual nanowires. An enhancement of the total magnetic anisotropy is found at room temperature with a decreasing nanowire diameter-to-length ratio (d/L), a result that is quantitatively analyzed on the basis of a simplified shape anisotropy model.Comment: 8 pages, 4 figure

Design issues for the VLSI implementation of universal approximator fuzzy systems

Several VLSI realizations of fuzzy systems have been proposed in the literature in the recent years. They employ analog or digital circuitry, offering more or less programmability, implementing difference inference methods, with different types of membership functions as well as different antecedents’ connectives. This paper centers this wide design space by fixing several parameters that allowefficient VLSI implementations of programmable fuzzy systems featuring first, second and third order accurate approximation. Hardware requirements are discussed and compared from the point of view of approximation capability or precision, thus attempting to a formalization that has never been applied before to the field of fuzzy hardwareCICYT TIC98-086

NORFREA: An algorithm for non redundant fuzzy rule extraction

This contribution presents a new algorithm (NORFREA) to select fuzzy rules from a grid partition of the input domain. Besides using an efficiency measure for the rules, this algorithm employs an heuristic technique to reduce the influence of the initial grid structure. Different benchmarks of classification problems are included to illustrate the advantages of this algorith

Obtención de lípidos bioactivos de Pleuroncodes monodon utilizando solventes orgánicos y CO2 supercrítico

A huge volume of Engraulis ringens (Peruvian anchoveta) is caught together with the species Pleuroncodes monodon (munida), whose potential bioactive lipids are not commercially exploited. In the present study, lipid with carotenoid pigment (astaxanthin) and essential fatty acids (EPA+DHA) were obtained from munida lipids extracted with hexane:isopropyl alcohol (He-I), acetone (Ac), ethanol (Et) and supercritical CO2 + ethanol (SC-CO2-Et). The functional quality of the fatty acids was determined by atherogenicity index (AI), thrombogenicity index (TI) and the hypocholesterolemia:hypercholesterolemia (H:H) ratio. The highest astaxanthin (ASTX) contents (4238.65 and 4086.71 µg/g lipid) corresponded to extractions using Ac and SC-CO2-Et. EPA+DHA ranged from 31.15 to 31.85% and the functional quality ranges were between 0.56-0.61 (AI), 0.19-0.21 (TI) and 1.73-1.81 (H:H). Consequently, SC-CO2-Et extraction would be advisable because of its low environmental impact. The IA and IT quality indexes suggest that the consumption of munida lipids would be healthy, although the H:H ratio shows the opposite.RESUMEN Las enormes capturas de Engraulis ringens (anchoveta Peruana) son acompañadas por la especie Pleuroncodes monodon (munida) cuyo potencial en lípidos bioactivos no es aprovechado comercialmente. En el presente estudio se obtuvo lípidos con pigmentos carotenoides (astaxantina) y ácidos grasos esenciales (EPA+DHA) a partir de lípidos de munida extraídos con hexano:alcohol isopropílico (He-I), acetona (Ac), etanol (Et) y CO2 supercrítico + etanol (SC-CO2-Et). La calidad funcional de los ácidos grasos fue evaluada mediante índices de aterogenicidad (AI), trombogenicidad (TI) y la relación hipocolesterolemia:hipercolesterolémica (H:H). Los mayores contenidos de astaxantina (ASTX) (4238.65 y 4086.71 µg/g de lípido) fueron obtenidos utilizando Ac y SC-CO2-Et. En todas las muestras EPA+DHA osciló entre 31.15 y 31.85% y los rangos de índices de calidad funcional fueron: 0.56-0.61 (AI), 0.19-0.21 (TI) y 1.73-1.81 (H:H). Se concluye que la extracción SC-CO2-Et sería recomendable por su bajo impacto al medio ambiente. Los índices de calidad AI y TI sugieren que el consumo de lípido de munida podría ser saludable, aunque la relación H:H muestra lo contrario

Proposal of ABC Methodology Through case Designs Derived from the Characteristics of the Work

El presente estudio es de tipo cualitativo y diseño no experimental, en el cual se tomó como punto de partida cinco casos de estudio del Instituto Nacional de Seguridad y Salud en el Trabajo (INSST) de España, los cuales se vincularon con el tema “Características del trabajo” de la Experiencia Educativa de Seguridad e higiene y se adaptaron a la normatividad mexicana vigente, para lo cual se aplicó la metodología activa de “Aprendizaje Basado en Casos (ABC)”, la cual proporciona al alumno casos análogos a la vida real y específicos, fortaleciendo sus habilidades de investigación, creación de conocimientos y razonamiento crítico, dicha metodología se subcategorizó en siete etapas, dando como resultado casos enfocados a la problemática actual que se vive en México.The present study is of a qualitative type and non-experimental design, in which five case studies from the National Institute of Safety and Health at Work (INSST) of Spain were taken as a starting point, which were linked to the topic “Characteristics of work” of the Safety and Hygiene Educational Experience and were adapted to current Mexican regulations, for which the active methodology of “Case-Based Learning (ABC)” was applied, which provides the student with cases analogous to real life and specific, strengthening their research skills, knowledge creation and critical reasoning, said methodology was subcategorized into seven stages, resulting in cases focused on the current problems experienced in Mexico

Clustering of Luminous Red Galaxies IV: Baryon Acoustic Peak in the Line-of-Sight Direction and a Direct Measurement of H(z)

We study the clustering of LRG galaxies in the latest spectroscopic SDSS data releases, DR6 and DR7, which sample over 1 Gpc^3/h^3 to z=0.47. The 2-point correlation function \xisp is estimated as a function of perpendicular $\sigma$ and line-of-sight $\pi$ (radial) directions. We find a significant detection of a peak at $r\simeq 110$Mpc/h, which shows as a circular ring in the $\sigma-\pi$ plane. There is also significant evidence for a peak along the radial direction whose shape is consistent with its originating from the recombination-epoch baryon acoustic oscillations (BAO). A \xisp model with no radial BAO peak is disfavored at $3.2\sigma$, whereas a model with no magnification bias is disfavored at $2\sigma$. The radial data enable, for the first time, a direct measurement of the Hubble parameter $H(z)$ as a function of redshift. This is independent from earlier BAO measurements which used the spherically averaged (monopole) correlation to constrain an integral of $H(z)$. Using the BAO peak position as a standard ruler in the radial direction, we find: $H(z=0.24)= 79.69 \pm 2.32 (\pm 1.29)$ km/s/Mpc for z=0.15-0.30 and $H(z=0.43)= 86.45 \pm 3.27 (\pm 1.69)$ km/s/Mpc for $z=0.40-0.47$. The first error is a model independent statistical estimation and the second accounts for systematics both in the measurements and in the model. For the full sample, $z=0.15-0.47$, we find $H(z=0.34)= 83.80 \pm 2.96 (\pm 1.59)$ km/s/Mpc.Comment: Minor revision to match version accepted for publication in MNRAS. Includes comparison to DR7, a Table with the measurements and errors. Includes extended analysis on systematic errors. Some figures have been omitted. Main results and conclusions remain unchange

Origin of the band gap in Bi intercalated graphene on Ir 111

Proximity to heavy sp elements is considered promising for reaching a band gap in graphene that could host quantum spin Hall states. The recent report of an induced spin orbit gap of 0.2 eV in Pb intercalated graphene detectable by spin resolved photoemission has spurred renewed interest in such systems [ACS Nano 11, 368 2017 ]. In the case of Bi intercalation an even larger band gap of 0.4 eV has been observed but was assigned to the influence of a dislocation network [Phys. Rev. B 93, 165437 2016 ]. Here, we study Bi intercalation under graphene on Ir 111 and report a nearly ideal graphene dispersion without band replicas and no indication of hybridization with the substrate. The band gap is small 0.19 eV and can be tuned by 25 meV through the Bi coverage. The Bi atomic density is higher than in the recent report. By spin resolved photoemission we exclude induced spin orbit interaction as origin of the gap. Quantitative agreement of a photoemission intensity analysis with the measured band gap suggests sublattice symmetry breaking as one of the possible band gap opening mechanisms. We test several Bi structures by density functional theory. Our results indicate the possibility that Bi intercalates in the phase of bismuthene forming a graphene bismuthene van der Waals heterostructur