Search results for " dose"

EP-1590: Shielding design and fetal dose evaluation of a breast cancer pregnant patient undergoing HDR Ir-192 brachytherapy

2015

Low Dose-Rate, High Total Dose Set-Up for Rad-Hard CMOS I/O Circuits Testing

2017

In this paper, the planning of low dose-rate, high total dose testing campaign for I/O circuits is reported. In particular, the paper describes all development steps, starting from the rad-hard I/O circuits design and the implementation of the test-chip, which is meant to allow comparative testing between rad-hard and standard devices. The designed experimental setup permits in situ measurements, therefore the circuits behavior can be remotely monitored for very long periods. This feature enables low dose-rate testing up to very high dose.

Un sistema innovativo per l'agricoltura di precisione. Prime prove di diserbo a dose variabile

2001

Analysis of response of PVA-GTA Fricke gel dosimeters through magnetic resonance imaging.

2017

The experimental activities here reported are focused on the analysis of the clinical applications of Fricke gel dosimeters produced with a matrix of Polyvinyl alcohol (PVA) cross-linked by adding glutaraldehyde (GTA). The analyses were performed by means of a 1.5 T clinical magnetic resonance imaging (MRI) scanner. The sensitivity of these dosimetric gels to clinical photon beams as well as the signal stability were suitably investigated. Furthermore, the effect of the xylenol orange on the MRI signal was analyzed. The results obtained show that these PVA-GTA gel dosimeters show good dosimetric features for possible future use for 3D dose mapping in clinical applications.

EVALUATION OF ENVIRONMENTAL NEUTRON DOSE AT GROUND LEVEL

2021

This work presents the results of two cycles of neutron dose rate measurements realized using an ALNOR 2202D Neutron Dose Rate Meter whose time response is acquired and analyzed through a controlled ORTEC MCS-32 acquisition card in Windows environment. The data obtained have been compared with values from previous experimental surveys and with the data provided by the worldwide main observatories. It has been also verified the influence of the fluctuations in the flux of cosmic rays during the course of a solar cycle. By comparing the realized measurements and the data provided by the cosmic ray monitoring networks it is also possible to obtain a value of ambient dose equivalent rate and ne…

Calcolo dei livelli di dose gamma e dei livelli di radon dovuta ai materiali da costruzione

2016

La radioattività delle famiglie di radionuclidi naturali contenuti nei materiali da costruzione è responsabile in una certa misura dell'equivalente di dose riferibile al fondo naturale delle radiazioni. Tale radioattività contribuisce a due fattori di dose: la dose gamma esterna e la dose alfa interna legata all'introduzione e all'accumulo del radon nonché ad un contributo dovuto all’inalazione di polveri nelle quali le concentrazioni dei capostipiti naturali sono alte. I materiali da costruzione sono la sorgente principale del rateo di dose gamma nelle abitazioni. Tutti gli edifici in pietra contengono nuclei radioattivi come 226Ra, 232Th e 40K. É noto che i livelli di radon sono legati al…

FMECA Analyses of radiological over-exposure accident to patients in brachytherapy

2012

This paper presents safety analyses of accidental events which can involve patient during High Dose Rate brachytherapy treatment in over-exposures. The study has been performed by using the well-known techniques FMECA modified by Fuzzy logic theory. Moreover, fuzzy HEART methodology was employed in order to evaluate human error probabilities for each treatment stage. The obtained results, aimed to obtain a list of the deviations with a reasonable probability to produce significant adverse outcomes, provided some recommendations for procedures and safety equipments to reduce the occurrence of radiological over-exposure accidents.

Down with the erythropoietin. Long live the erythropoietin!

2009

In recent years the use of erythropoietin has exploded, and the anaemia of patients with chronic renal failure has been practically resolved with the administration of rHuEpo (recombinant human, Erythropoietin). However, as a result of an intense commercial campaign, strong therapies with this growth hormone, prescribed to achieve surprising sporting performances, got athletes to run the risk of thrombosis and vascular accidents because of red blood cells increase. Erythropoietin represents a significant subject of research. In fact, besides the ability of stimulating erythrocyte production, it has many pleiotropic effects. Several studies allow the assertion that EPO, in different concentr…

Correction factors for ionization chamber measurements with the ‘Valencia’ and ‘large field Valencia’ brachytherapy applicators

2018

Treatment of small skin lesions using HDR brachytherapy applicators is a widely used technique. The shielded applicators currently available in clinical practice are based on a tungsten-alloy cup that collimates the source-emitted radiation into a small region, hence protecting nearby tissues. The goal of this manuscript is to evaluate the correction factors required for dose measurements with a plane-parallel ionization chamber typically used in clinical brachytherapy for the 'Valencia' and 'large field Valencia' shielded applicators. Monte Carlo simulations have been performed using the PENELOPE-2014 system to determine the absorbed dose deposited in a water phantom and in the chamber act…

Radiation Hardness Assurance Through System-Level Testing: Risk Acceptance, Facility Requirements, Test Methodology, and Data Exploitation

2021

International audience; Functional verification schemes at a level different from component-level testing are emerging as a cost-effective tool for those space systems for which the risk associated with a lower level of assurance can be accepted. Despite the promising potential, system-level radiation testing can be applied to the functional verification of systems under restricted intrinsic boundaries. Most of them are related to the use of hadrons as opposed to heavy ions. Hadrons are preferred for the irradiation of any bulky system, in general, because of their deeper penetration capabilities. General guidelines about the test preparation and procedure for a high-level radiation test ar…