Search results for "Gamma"
showing 10 items of 3093 documents
Influence of gamma-irradiation on thermally-induced mesoscopic gelation of degalactosylated xyloglucans
2014
Thermoresponsive degalactosylated xyloglucans have been already proposed as in situ gelling scaffolds for tissue engineering, due to their reversible macroscopic thermal gelation at body temperature and biodegradability. The highly branched, hydroxyl group-rich molecular structure renders xyloglucans interesting raw materials also in the form of micro/nanoparticles for application as nanoscalar drug delivery devices in cosmetic and pharmaceutical formulations. Owing to their natural source, xyloglucans show high average molecular weight, broad molecular weight distribution and poor water solubility, as large and compact aggregates usually form via inter-molecular hydrogen bonding. Co-60 gam…
High energy radiation cure of resin systems for structural adhesives and composite applications
2002
Abstract Radiation cure polymerisation of a commercial diglycidyl ether of bisphenol F epoxy resin has been achieved using a 60Co irradiation source, compounding the monomer with few percentage of an onium salt catalyst. The cure process has been monitored by a gamma-calorimetric technique and systems irradiated at doses corresponding to different positions in the gamma-calorimetric curve have been characterised via solubility tests and dynamic mechanical torsion analysis. Changes in both the measured gel fractions and tan δ values were associated with the progress of polymerisation and crosslinking reactions and these were dose dependent. Furthermore, systems irradiated at lower doses exhi…
Gamma radiation of EVA-AA/MMA swollen systems to obtain mechanically improved blends
2002
In this work a "new" way to obtain "compatibilised" blends of rubber-glassy thermoplastic components is presented. Polyethylen-vinyl acetate acrylic acid terpolymer is swollen by methylmetacrylate and the system is irradiated through gamma rays in order to induce polymerisation of the monomer. Solubility and dynamic mechanical tests indicate the formation of a two phase system, even though in presence of strong interactions between the two components. Mechanical tensile behaviour is that of a ductile material with appreciable modulus values.
Effects of gamma-irradiation on the alpha-tocopherol and fatty acids content of raw unpeeled almond kernels (Prunus dulcis)
2014
Abstract The present study evaluated fatty acid composition and α-tocopherol content of almond as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to almonds. Raw unpeeled almonds variety Tuono ( Prunus dulcis (Mill.) D. A. Webb) were irradiated using 60 Co source at dose of 0.5, 1.5, 3, 6, 8 and 10 kGy. Both control and irradiated samples were kept frozen and immediately analyzed. The data obtained showed no change in fatty acid compositions up to a dose of 10 kGy; on the contrary, a general trend observed is that increasing the dose of irradiation resulted in the decrease of α-tocopherol content. The study has shown that irradiation is a…
Lifetime measurement of neutron-rich even-even molybdenum isotopes
2017
D. Ralet et al. -- 11 pags., 10 figs., 3 tabs.
The detection efficiency of the clover Ge-detectors array at the RITU-GREAT facility
2015
Absolute detection efficiency depending upon its position along the beam line is determined for three germanium detectors, that are part of the GREAT spectrometer at the RITU separator focal plane. The efficiency is determined for an energy range from 80 keV to 1400 keV for all three detectors as an array and also individually using digital electronics. The optimal position for the detector array has been defined for two configurations of the GREAT spectrometer: with planar detector and without it. The obtained results have been compared with three references: a simulation prepared especially for this setup by another student, a previous study that was carried out by applying analogue elect…
Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications
2009
Over the last decade, cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector…
Improving Image Quality in a multi-plane Compton Telescope for Hadron Therapy Monitoring
2023
Esta disertación explora diferentes técnicas para mejorar la calidad de las imágenes obtenidas con cámaras Compton. Tal mejora es una de las necesidades principales que obstaculizan la aplicación de cámaras Compton como herramientas para la verificación en tiempo real de terapia hadrónica, a través de la obtención de imágenes de distribuciones espaciales de emisión rápida de rayos gamma emitidos como subproductos de las interacciones de estos hadrones en el paciente. Esta aplicación presenta importantes dificultades, pues requiere medir rayos gamma de energías relativamente altas emitidos en un rango de energías amplio y junto a otras partículas no deseadas. Además, la cámara Compton debe s…
IV Gamma, focus sulla bietola
2011
La bietola da foglie, Beta vulgaris var. cicla, è una specie nativa dell'Europa meridionale, dove cresce spontanea nella regione del Mediterraneo; ne esistono numerose varietà dato che si coltiva in tutte le zone temperate del mondo. E' ampiamente apprezzata per le sue foglie, utilizzate crude nelle insalate o cotte come gli spinaci. Le bietole da foglia possono essere impiegate per la preparazione di prodotti di IV gamma, ovvero prodotti orticoli freschi che, previa pulitura e taglio vengono confezionati e risultano quindi pronti per essere consumati. Scopo della presente ricerca è stato quello di valutare l'adattabilità della bietola alla trasformazione in prodotto di IV gamma e le modifi…
LA LAVORAZIONE DEGLI ORTAGGI DESTINATI AL CONFEZIONAMENTO IN IV GAMMA: CONSUMO DI ENERGIA E CAPACITÀ DI LAVORO
2006
Vengono analizzate le macchine per la lavorazione dei prodotti ortivi di IV gamma. I risultati valutano i consumi energetici e le capacità di lavoro.