1,721,153 research outputs found
EDEL: ENEA dosemeter for eye lens
No full textSince the publication of International Commission on Radiological Protection statement in 2011 on tissue reaction, eye lens radiation protection played an important role in exposed personnel dosimetry. For this reason, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) Individual Monitoring Service decided to study a prototype to fulfil specific requests (e.g. for survey in interventional department and intercomparisons). On the basis of such preliminary investigation, a new eye lens dosemeter was developed. The new dosemeter, named EDEL (ENEA Dosemeter for Eye Lens), was characterised in terms of Hp(3), the operational quantity related to eye lens monitoring. The investigation was performed experimentally and optimised using the Monte Carlo MCNP6 code. The new prototype was thought to fulfil two main requests: the reliability of the dosimetric data and the portability of the dosemeter itself. The new dosemeter will soon be supplied to the collaborating hospitals for workplace test measurements. © The Author 2015. Published by Oxford University Press. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Air kerma to hp(3) conversion coefficients for photons from 10 kev to mev, caliculated in a cylindrical phantom
No full textIn the framework of the ORAMED project (Optimization of RAdiation protection for MEDical staff), funded by the European Union Seventh Framework Programme, different studies were aimed at improving the quality of radiation protection in interventional radiology and nuclear medicine. The main results of the project were presented during a final workshop held in Barcelona in January 2011, the proceedings of which are available in the open literature. One of the ORAMED tasks was focused on the problem of eye-lens photon exposure of the medical staff, a topic that gained more importance especially after the ICRP decision to lower the limiting equivalent dose to 20 mSv per year. The present technical note has the scope, besides briefly summarising the physical reasons of the proposal and the practical implications, to provide, in tabular form, a set of air kerma to Hp(3) conversion coefficients based on the adoption of a theoretical cylindrical model that is well suited for reproduction of the mass and the shape of a human head. © The Author 2012. Published by Oxford University Press. All rights reserved
The ENEA neutron personal dosimetry service
No full textThe ENEA Radiation Protection Institute has been operating the only neutron personal dosimetry service in Italy since the 1970s. Since the 1980s the service has been based on PADC (poly allyl diglycol carbonate) for fast neutron dosimetry, while thermal neutron dosimetry has been performed using thermoluminescence (TL) dosemeters. Since the service was started, a number of aspects have undergone evolution. The latest and most important changes are as follows: in 1998 a new PADC material was introduced in routine, since 2001 TL thermal dosimetry has been based on LiF(Mg,Cu,P) [GR-200] and 7LiF(Mg,Cu,P) [GR-207] detectors and since 2003 a new image analysis reading system for the fast neutron dosemeters has been used. Herein an updated summary of how the service operates and performs today is presented. The approaches to calibration and traceability to estimate the quantity of Hp(10) are mentioned. Results obtained at the performance test of dosimetric services in the EU member states and Switzerland sponsored by the European Commission and organised by Eurados in 1999 are reported. Last but not least, quality assurance (QA) procedures introduced in the routine operation to track the whole process of dose evaluation (i.e. plastic QA, acceptance test, test etching bath reproducibility and 'dummy customer' (blind test) for each issuing monitoring period) are presented and discussed
Performance of CR-39 with Addition of DOP (Dioctylphthalate) for Fast Neutron Dosimetry
No full textThe ENEA fast neutron dosemeter is based on a planar PADC (Poly Allyl Diglicol Carbonate)placed in a polyethylene holder. The present paper reports the results of an experimental study of a CR-39 material with the addition of 0.l% of DOP (Dioctylphthalate) produced by the Italian company Intercast Europe S.p.A.The etching procedure is: pre-etching with 40% KOH water solution 6.25 N and 60% ethyl a1coholat 70°C followed by 12 hours of etching in 6.25 N KOH water solution. For the energy dependenceof response, dosemeters have been irradiated with neutron sources (241Am-Be, 252Cf, Pu-Li) andl4.9 MeV monoenergetic neutrons. The dosimetric performance of the material for fast neutrons isexpressed in terms of sensitivity, background value, lowest detectable dose and energy dependence of response. Moreover, the results of a quality acceptance test of the material, performed on 1l sheets (980x980 mm2, 1.4 mm thick) of the same production batch, are given. Therefore, the homogeneity of the neutron sensitivity and of the background signal within a sheet and the whole batch is considered. The results are compared with the acceptance test outcome for a CR39 standard material batch
Batch homogeneity of LiF(Mg,Cu,P)-GR200 and LiF(Mg,Cu,P)-MCP-NS TL detectors for use as extremity dosemeters at ENEA personal dosimetry service
No full textThe results of a study of two commercially available LiF(Mg,Cu,P) TL materials, a GR200 detector and a MCP-Ns thin detector, are described in order to use these phosphors for individual monitoring for the extremities. After a dosimetry system has been type tested, the implementation routine is not straightforward. Additional tests and software modification are needed to make the routine system work comply with the type test results. Not often can literature be found on the steps required to implement the results in a routine study. This paper reports the results of the individual calibration of about 15 000 extremity dosemeters, 12 000 containing a GR200 detector and 3000 an MCP-Ns thin detector. It describes the experimental procedure followed in order to assure reproducibility and stability of the results with proper accuracy and reliability. In particular, this is the first time that results on homogeneity of such a large batch of MCP-Ns detectors are reported
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Test di qualità del materiale CR39 per dosimetria neutronica: risultati e messa a punto dei criteri di accettabilità
No full textIl dosimetro per neutroni veloci, attualmente in uso presso il Servizio di Dosimetria Personale dell'Istituto di Radioprotezione dell'ENEA, è costituito da un rivelatore a tracce di PADC (polyallyl-diglicol-carbonate), commercialmente denominato CR-39, prodotto dalla ditta Intercast Europe S.p.A. di Parma. Gli studi effettuati, sia sulla composizione chimica del materiale che sulle modalità di trattamento dello stesso nel corso degli ultimi anni, finalizzati al miglioramento delle caratteristiche dosimetriche (sensibilità, segnale di fondo, soglia di rivelazione, dipendenza della risposta dall'energia dei neutroni incidenti), hanno condotto alla scelta di rivelatore di CR-39 addizionato con 0,1 % di DOP (Dioctylphthalate).Una volta stabilita la composizione ottimale del materiale, è stato necessario però attuare una procedura di test di accettazione di una partita di rivelatori. Nel caso del CR39, ciò significa effettuare un test su campioni di rivelatori appartenenti a ciascuna lastra di un gruppo di lastre appartenenti allo stesso ciclo di produzione. A questo scopo sono stati stabilite le procedure del test di controllo sulla intera partita ed i criteri di accettabilità. Sono presentati i risultati dei test su partite relative a diversi anni di produzione.In collaborazione con la Intercast Europe S.p.A., è stato inoltre avviato uno studio allo scopo di valutare quali parametri legati al ciclo di produzione influenzano, e in che misura, la qualità del materiale. Diversi fattori del processo di produzione, infatti, quali la zona di iniezione della miscela nello stampo, la posizione della lastra e la non uniformità del calore all'interno del forno, possono essere causa della possibile disomogeneità CR-39 e comprometterne le prestazioni dosimetriche. Nel presente lavoro sono presentati i risultati del test di accettazione effettuato su di una intera lastra di materiale prodotto nel 2003 (circa 1000 rivelatori). I risultati ottenuti hanno permesso di verificare le procedure di controllo di qualità esistenti (tempistica, dimensione e modalità scelta campioni) e convalidare i criteri di accettabilità.Gli studi effettuati hanno confermato l'importanza dei test di accettazione del materiale di rivelazione ai fini di assicurare all'utente una migliore qualità ed affidabilità del servizio di dosimetria fornito
- …
