Search results for "uci"
showing 10 items of 5317 documents
Combined TL and 10B-alanine ESR dosimetry for BNCT
2004
The dosimetric technique described in this paper is based on electron spin resonance (ESR) detectors using an alanine-boric compound acid enriched with 1 0 B, and beryllium oxide thermoluminescent (TL) detectors; with this combined dosimetry, it is possible to discriminate the doses due to thermal neutrons and gamma radiation in a mixed field. Irradiations were carried out inside the thermal column of a TRIGA MARK II water-pool-type research nuclear reactor, also used for Boron Neutron Capture therapy (BNCT) applications, with thermal neutron fluence from 10 9 to 10 1 4 n t h cm - 2 . The ESR dosemeters using the alanine-boron compound indicated ESR signals about 30-fold stronger than those…
Alanine blends for ESR measurements of thermal neutron fluence in a mixed radiation field
2007
In this paper, the results of a study on the electron spin resonance (ESR) dosimetry to measure thermal neutron fluence in a mixed radiation field (neutron and photons) are presented. The ESR responses of alanine dosemeters with different additives are compared. In particular, the (10)B-acid boric and the Gd-oxide were chosen to enhance the sensitivity of alanine dosemeters to thermal neutrons. Irradiations were carried out inside the thermal column of the TAPIRO reactor of the ENEA center, Casaccia Rome. The main results are a greater neutron sensitivity and a smaller lowest detectable fluence for the dosemeters with gadolinium than for dosemeters of alanine with (10)B, which is well known…
One pot light assisted green synthesis, storage and antimicrobial activity of dextran stabilized silver nanoparticles.
2014
Background Green synthesis of nanomaterials finds the edge over chemical methods due to its environmental compatibility. Herein, we report green synthesis of silver nanoparticles (Ag NPs) mediated with dextran. Dextran was used as a stabilizer and capping agent to synthesize Ag NPs using silver nitrate (AgNO3) under diffused sunlight conditions. Results UV–vis spectra of as synthesized Ag nanoparticles showed characteristic surface plasmon band in the range from ~405-452 nm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies showed spherical Ag NPs in the size regime of ~50-70 nm. Face centered cubic lattice of Ag NPs was confirmed by powder X-ray diffraction (PXRD…
Role of glutathione in the formation of the active form of the oxygen sensor FNR ([4Fe-4S]·FNR) and in the control of FNR function
2000
The oxygen sensor regulator FNR (fumarate nitrate reductase regulator) of Escherichia coli is known to be inactivated by O2 as the result of conversion of a [4Fe-4S] cluster of the protein into a [2Fe-2S] cluster. Further incubation with O2 causes loss of the [2Fe-2S] cluster and production of apoFNR. The reactions involved in cluster assembly and reductive activation of apoFNR isolated under anaerobic or aerobic conditions were studied in vivo and in vitro. In a gshA mutant of E. coli that was completely devoid of glutathione, the O2 tension for the regulatory switch for FNR-dependent gene regulation was decreased by a factor of 4–5 compared with the wild-type, suggesting a role for glutat…
Formation and growth of palladium nanoparticles inside porous poly(4-vinyl-pyridine) monitored by operando techniques: The role of different reducing…
2017
In this work we followed the formation of palladium nanoparticles, starting from palladium (II) acetate precursor, inside a poly(4-vinylpyridine-co-divinylbenzene) polymer in presence of different reducing agents. The formation and growth of palladium nanoparticles in presence of H-2 was followed as a function of temperature by simultaneous XANES-SAXS techniques, coupled with DRIFT spectroscopy in operando conditions. It was found that the pyridyl functional groups in the polymer plays a fundamental role in the stabilization of the palladium (II) acetate precursor, as well as in the stabilization of the palladium nanoparticles. The effect of a thermal treatment in alcohol (ethanol and 2-pro…
EPR DOSIMETRY IN A MIXED NEUTRON AND GAMMA RADIATION FIELD
2004
Suitability of Electron Paramagnetic Resonance (EPR) spectroscopy for criticality dosimetry was evaluated for tooth enamel, mannose and alanine pellets during the 'international intercomparison of criticality dosimetry techniques' at the SILENE reactor held in Valduc in June 2002, France. These three materials were irradiated in neutron and gamma-ray fields of various relative intensities and spectral distributions in order to evaluate their neutron sensitivity. The neutron response was found to be around 10% for tooth enamel, 45% for mannose and between 40 and 90% for alanine pellets according their type. According to the IAEA recommendations on the early estimate of criticality accident a…
La insolvencia en el ámbito de las relaciones laborales: causas, efectos y propuestas
2015
La presente tesis doctoral viene a recoger el resultado de un profundo trabajo de investigación sobre la materia objeto de estudio, a saber, la insolvencia empresarial en el ámbito de las relaciones laborales, con especial concreción en el período de abarca desde el inicio de la denominada crisis económica (año 2007) hasta el presente, como una de las problemáticas a las que el derecho ha de hacer frente en el ámbito laboral. El texto viene a reflejar la relevancia de una urgente búsqueda de instrumentos jurídicos que permitan de un lado, resolver la problemática de la insolvencia empresarial desde su raíz, y de otro, reducir el impacto de sus efectos, especialmente sobre aquellos que recae…
La pertinencia curricular y social en las instituciones de Educación Superior
2019
Este proyecto parte de un enfoque sistémico de la Educación Superior y tiene como finalidad promover la calidad en las universidades donde se forman futuros maestros y maestras y otros profesionales del mundo educativo. Pretende fortalecer la dimensión social, la pertinencia curricular y la innovación docente en los singulares contextos formativos para impactar en las políticas y la gobernanza institucional. La publicación que les presentamos trata de la pertinencia curricular y social de los planes de estudios del ámbito educativo de las instituciones participantes y está dividida en dos partes principales: una primera parte en la que se detalla la creación, validación y análisis del instr…
Tema 5: El marco institucional de la Unión Europea (II), 5ª ed.
2022
6.- El Consejo. 7.- La Comisión Europea. 8.- El Tribunal de Justicia de la Unión Europea (composición y estructura orgánica). 9.- El Tribunal de Cuentas. 10.- El Banco Central Europeo. 11.- Los órganos consultivos. 12.- Otros órganos y organismos de la Unión Europea. 6.- The Council. 7.- The European Commission. 8.- The Court of Justice of the European Union (composition and organisational structure). 9.- The Court of Auditors. 10.- The European Central Bank. 11.- The consultative bodies. 12.- Other bodies and agencies of the European Union.
Tema 4: El marco institucional de la Unión Europea (I), 5ª ed.
2022
1.- Características del marco institucional. 2.- El reparto de competencias y funciones entre las instituciones. 3.- Principios rectores aplicables al marco institucional. 4.- El Parlamento Europeo. 5- El Consejo Europeo. 1.- Characteristics of the institutional framework. 2.- The distribution of competences and functions among the institutions. 3.- Guiding principles applicable to the institutional framework. 4.- The European Parliament. 5.- The European Council.