Search results for "Radiation induced"
showing 10 items of 34 documents
Investigating the Impact of Radiation-Induced Soft Errors on the Reliability of Approximate Computing Systems
2020
International audience; Approximate Computing (AxC) is a well-known paradigm able to reduce the computational and power overheads of a multitude of applications, at the cost of a decreased accuracy. Convolutional Neural Networks (CNNs) have proven to be particularly suited for AxC because of their inherent resilience to errors. However, the implementation of AxC techniques may affect the intrinsic resilience of the application to errors induced by Single Events in a harsh environment. This work introduces an experimental study of the impact of neutron irradiation on approximate computing techniques applied on the data representation of a CNN.
Radiation-induced vascular changes in the intracranial irradiation field in medulloblastoma survivors: An MRI study
2019
While survival times after treatment of medulloblastoma are increasing, little is known about radiochemotherapy (RCT)-induced cerebrovascular changes. High resolution vessel wall imaging (VWI) sequences are an emerging tool for the evaluation of cerebrovascular diseases. We performed VWI in medulloblastoma long-term survivors to screen for late sequelae of RCT.Twenty-two pediatric medulloblastoma survivors (mean age 25.8 years (10-53 years); 16.3 years (mean) post primary RCT (range 1-45 years)) underwent 2D VWI-MRI. Vessel wall thickening, contrast enhancement and luminal narrowing were analyzed. The findings were correlated with the patients' radiation protocols.Vessel wall changes were o…
Kinetische untersuchungen zur strahleninduzierten festkörperpolymerisation von trioxan und tetroxan IV. Mitt. der Reihe “kinetische und morphologisch…
1971
Die strahlungsinduzierte Polymerisation von kristallinem Tetroxan und Trioxan wurde untersucht und der Einflus von Strahlendosis, Reaktionszeit und -temperatur auf den Umsatz und das Molekulargewicht der entstehenden POM, insbesondere bei der Nachpolymerisation, studiert. Die Zeit-Umsatz-Kurven fur die Nachpolymerisation laufen bei beiden Monomeren asymptotisch gegen einem Grenzwert des Umsatzes, der mit steigender Reaktionstemperatur ansteigt. Die Aktivierungsenergie der Nachpolymerisation wurde zu 24 ± 2 kcal/Mol fur Tetroxan und zu 36–38 kcal/Mol fur Trioxan bestimmt. Die Zeit(t)-Umsatz(x)-Kurven fur Tetroxan lassen sich durch die empirische Gleichung: beschreiben, wobei k1 und k2 Konsta…
Formation, diffusion, and aggregation of radiation-induced defects in MgO and α-Al 2 O 3
1997
MgO and M2O3 (corundum) are important ceramic materials with several technological applications including theirpossible use in fusion reactors' . Weare therefore studying the properties ofpoint defects (vacancies, interstitials, andtheir aggregates) and electronic defects (trapped holes and electrons) in these materials. Pair-potential (PP) calculationswere carried out using the Mott-Littleton (ML) two-region strategy, as implemented in the computer code CASCADEdue to Leslie. Details ofthe method, including the construction ofPPs, are in the literature3. For semi-empirical INDO(intermediate neglect ofdifferential overlap) calculations computer codes developed at the University of Riga were …
Formation of self-trapped excitons through stimulated recombination of radiation-induced primary defects in alkali halides
1998
Abstract A self-trapped exciton formation through photostimulated recombination of an F and an H center — the exciton-created primary defect pair, is proposed and experimentally examined in alkali halides at low temperatures.
EPR on Radiation-Induced Defects in SiO2
2014
Continuous-wave electron paramagnetic resonance (EPR) spectroscopy has been the technique of choice for the studies of radiation-induced defects in silica (SiO2) for 60 years, and has recently been expanded to include more sophisticated techniques such as high-frequency EPR, pulse electron nuclear double resonance (ENDOR), and pulse electron spin echo envelope modulation (ESEEM) spectroscopy. Structural models of radiation-induced defects obtained from single-crystal EPR analyses of crystalline SiO2 (alfa-quartz) are often applicable to their respective analogues in amorphous silica (a-SiO2), although significant differences are common.
Radiācijas defektu EPR fluorīdu kristālos un oksifluorīdu stikla keramikā
2008
Elektroniskā versija nesatur pielikumus
Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy
2011
Abstract The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.
NHL-ChirEx: An interprofessional cross-border education initiative in the Greater Region with a focus on radiation morbidity and patient safety
2018
NHL-ChirEx is an interprofessional cross-border education project that addresses the potential excess of radiation induced morbidity throughout the radiation planning and treatment process. NHL-ChirEx is supported by ESTRO and the University of the Greater Region and has been recently approved and funded under INTERREG VA Programme.
Polymerization reactions and modifications of polymers by ionizing radiation
2020
International audience; Ionizing radiation has become the most effective way to modify natural and synthetic polymers through crosslinking, degradation, and graft polymerization. This review will include an in-depth analysis of radiation chemistry mechanisms and the kinetics of the radiation-induced C-centered free radical, anion, and cation polymerization, and grafting. It also presents sections on radiation modifications of synthetic and natural polymers. For decades, low linear energy transfer (LLET) ionizing radiation, such as gamma rays, X-rays, and up to 10 MeV electron beams, has been the primary tool to produce many products through polymerization reactions. Photons and electrons in…