The neutron time-of-flight facility n-TOF at CERN: Phase II

Neutron-induced reactions are studied at the neutron time-of-flight facility n-TOF at CERN. The facility uses 6∼ns wide pulses of 20 GeV/c protons impinging on a lead spallation target. The large neutron energy range and the high instantaneous neutron flux combined with high resolution are among the key characteristics of the facility. After a first phase of data taking during the period 2001-2004, the facility has been refurbished with an upgraded spallation target and cooling system for a second phase of data taking which started in 2009. Since 2010, the experimental area at 185 m where the neutron beam arrives, has been modified into a worksector of type A, allowing the extension of the physics program to include neutron-induced reactions on radioactive isotopes

JAMDER: JADE to MULTI-Agent Systems Development Resource

The semantic gap is distinguished by the difference between two descriptions generated using different representations. This difference has a negative impact on the developer productivity and probably, the quality of the written code. In software development context, the coding phase aims at coding the system consistent with the detailed project developed with a group of designed models. This paper presents an endeavor to consolidate different agent type definitions and implementation concepts for Multi-Agent Systems (MAS) involving the adaptation of the JADE framework regarding the theoretical concepts in MAS. Additionally, it contains a standardization of code generation. The main benefit of the proposed extension is to include the agent internal architectures, entities and relationships in an implementation framework and increase the productivity by code generation, ensuring the consistency between design and code. The applicability of the extension is illustrated by developing a multi-agent system for Moodle

Novel dual single sided silicon strip detector chip for radiotherapy verification

A novel dual single sided silicon strip detector (SSSSD) chip was designed to meet clinical requirements in radiotherapy verification. An available design from Micron Semiconductor Ltd. (BB7, 500 µ m thick) was the base of a two-dimensional detector adapted into a special configuration with the aim of uniforming and minimizing foreing materials around the active area (64 × 64 mm2). With this purpose, two independent BB7 SSSSDs were mounted in a perpendicular configuration, separated by a 500 µ m kapton dielectric film with the same dimensions as the silicon wafers, thus minimizing air gaps in between. This new configuration, called the dual SSSSD chip design, was mounted on kapton printed circuit board (PCB). Both silicon wafers were divided into 32 strips, 2 mm width each. The aim of developing this detector was to allow 2D dose measurements, improve spatial resolution and perform radiotherapy treatment verification faster than with a previous prototype. Characteristics and performance of the novel detector are presented

Influence of La3+ on the microestructure of bismuth titanate solid solutions

[ES] En este trabajo se reporta la síntesis de la serie de soluciones sólidas de titanato de bismuto, Bi4Ti3O12 con La3+ por coprecipitación de los respectivos hidróxidos. Las soluciones sólidas se caracterizaron por difracción de rayos-X y medidas de densidad. Por técnicas de SEM se determinó la influencia del La3+ en la microestructura del titanato de bismuto puro. En este estudio se prepararon diversas composiciones de la solución sólida a y se sinterizaron a 850ºC. Los resultados se presentan en función de la concentración del dopante.[EN] In this work a solid solution of bismuth titanate Bi4Ti3O12 with La3+ is synthesised by coprecipitation of their hydroxides. The solid solutions were characterised by X-ray powder diffraction and density measurements. By SEM the influence of La3+ in bismuth titanate was analised. In this study several compositions of the solid solution were prepared and sintered at 850ºC. The results are presented as a function of the dopant concentration.Los autores agradecen el apoyo de los proyectos PAPIIT, DGAPA, UNAM No. IN102700 y CONACYT No. 33361-U.Peer reviewe

Vibrational characterictics of asymmetric metal-ceramic piezocomposites

[ES] Se han estudiado las características mecánico-vibracionales de piezocomposites metal-cerámica asimétricos. Kovar-PZT. Para esta caracterización se utilizó la técnica de vibrometría láser mediante la cual se obtienen perfiles de amplitud a diferentes frecuencias para el piezocomposite. Se muestran los modos diferenciados de vibración en el intervalo de 2 Hz a 20 kHz y se discuten los resultados en la perspectiva de optimizar el diseño de los dispositivos.[EN] The mechanical and vibrational characteristics of asymmetric metal-ceramic piezocomposites, Kovar-PZT, have heen studied. For this characterization a laser vibrometry technique was used to obtain amplitude profiles of vibration at different frequencies for the piezocomposite. The vibration spectra showed modes in the range 2 Hz to 20 kHz. The results were discussed in the framework of design optimization.Los autores agradecen el apoyo financiero para la realización de esta investigación a la Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología de México, Comisión Internacional de Ciencia y Tecnología de España y Programa para la Cooperación y el Desarrollo a través de los proyectos PAPIIT-IN106998, CONACYT-27624U, CICYT MAT97-694-C02-01 y CYTED Red VIII.F.Peer reviewe

Oxygen Atom Transfer and Oxidative Water Incorporation in Cuboidal Mn_(3)MO_n Complexes Based on Synthetic, Isotopic Labeling, and Computational Studies

The oxygen-evolving complex (OEC) of photosystem II contains a Mn_(4)CaO_n catalytic site, in which reactivity of bridging oxidos is fundamental to OEC function. We synthesized structurally relevant cuboidal Mn_(3)MO_n complexes (M = Mn, Ca, Sc; n = 3,4) to enable mechanistic studies of reactivity and incorporation of μ_(3)-oxido moieties. We found that Mn^(IV)_(3)CaO_4 and Mn^(IV)_(3)ScO_4 were unreactive toward trimethylphosphine (PMe_3). In contrast, our Mn^(III)_(2)Mn^(IV)_(2)O_4 cubane reacts with this phosphine within minutes to generate a novel Mn^(III)_(4)O_3 partial cubane plus Me_(3)PO. We used quantum mechanics to investigate the reaction paths for oxygen atom transfer to phosphine from Mn^(III)_(2)Mn^(IV)_(2)O_4 and Mn^(IV)_(3)CaO_4. We found that the most favorable reaction path leads to partial detachment of the CH_(3)COO^– ligand, which is energetically feasible only when Mn(III) is present. Experimentally, the lability of metal-bound acetates is greatest for Mn^(III)_(2)Mn^(IV)_(2)O_4. These results indicate that even with a strong oxygen atom acceptor, such as PMe_3, the oxygen atom transfer chemistry from Mn_(3)MO_4 cubanes is controlled by ligand lability, with the Mn^(IV)_(3)CaO_4 OEC model being unreactive. The oxidative oxide incorporation into the partial cubane, Mn^(III)_(4)O_3, was observed experimentally upon treatment with water, base, and oxidizing equivalents. ^(18)O-labeling experiments provided mechanistic insight into the position of incorporation in the partial cubane structure, consistent with mechanisms involving migration of oxide moieties within the cluster but not consistent with selective incorporation at the site available in the starting species. These results support recent proposals for the mechanism of the OEC, involving oxido migration between distinct positions within the cluster

Sistema embebido de procesamiento de vídeo para la realización de prácticas docentes

El Congreso TAEE'06, organizado por la Universidad Politécnica de Madrid,tuvo lugar entre el 12 de julio y el 15 de julio de 2006La realización, fomento y búsqueda de temas transversales en el proceso de enseñanza y aprendizaje, de manera que los contenidos curriculares se impregnen de ellos, es determinante para conseguir una docencia de calidad. Sin embargo, la estructura departamental universitaria no fomenta precisamente esta transversalidad. En un esfuerzo por mejorar las prácticas realizadas por Departamentos adscritos a la Escuela Superior de Ingenieros de Sevilla, se plantea el desarrollo de un entorno práctico para alumnos de la misma titulación y en asignaturas relacionadas con el diseño y desarrollo de sensores inteligentes y sistemas microprocesadores actuales y con los sistemas de percepción, visión y procesamiento de imágenes

Hypertension as a Risk Factor for Hip Fracture

Producción CientíficaArterial hypertension is a chronic disease in which prevalence increases with age, as occurs in osteoporosis. It is clinically silent and is only revealed in the form of complications, an aspect that it also shares with osteoporosis. Various alterations of calcium metabolism have been described in association with hypertension; such alterations can cause decreased bone mass, the principal determining factor of fracture.1,2 Another important factor is the occurrence of falls. Hypertensive patients may experience a greater number of falls resulting from fainting associated with diminished baroreflex sensitivity or hypotension secondary to therapy.3,4 The purpose of this study was to assess the effect of hypertension and its various therapeutic alternatives on the risk of hip fracture.2015-09-0

Measurement of the 70Ge(n,γ) cross section up to 300 keV at the CERN n_TOF facility

Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,γ) cross section on 70Ge, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT =5 keV tokT =100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sectionsareinagreementwithWalterandBeer(1985)overmostoftheneutronenergyrangecovered,whilethey aresystematicallysmallerforneutronenergiesabove150keV.Wehavecalculatedisotopicabundancesproduced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80.Austrian Science Fund J3503Adolf Messer Foundation ST/M006085/1European Research Council ERC2015-StGCroatian Science Foundation IP-2018-01-857