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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Radiační ochrana na oddělení nukleární medicíny / Radiation safety in the nuclear medicine department

ANTONÍNOVÁ, Eva January 2019 (has links)
The practice in the department of nuclear medicine requires the involvement of radiation protection with care of patients and occupational safety of radiation workers. Nuclear medicine involves the handling of radioactive substances that may cause external or internal irradiation of workers. The amount of the dose depends on the type of radionuclide, the amount of energy, the work performed by the worker within the department. Patients or staff may be exposed to the external or internal irradiation. The topic of this thesis is the analysis of the current state of radiation protection in the department of nuclear medicine according to the new legislation. The part of the work is the evaluation of monitoring of workers and patients. The research results of the average annual effective dose of total body irradiation at radiation workers ranged from 1.35 to 1.73 mSv, monthly ranged from 0.1? 0.65 mSv. The average annual equivalent dose of Hp (0,07) ranged from 1.15 to 117.68 mSw. The lowest monthly Hp (0.07) was 0.07 mSw and the highest one was 19.92 mSw. At SSK-treated patients the doses applied were 4% lower than diagnostic reference level and the dose at DSSL-treated patients was 22% less than DRU. In conclusion, it was found that the values from personal dosimeters were below the limit and in the case of finger dosimeters in two cases the values were above the examination level. The values of other workers were below the monitoring level during the monitored period. The applied doses of radiopharmaceuticals were less in the observed group of patients than the established diagnostic reference level. On the basis of the presented results it can be stated that radiation protection is in the Department of Nuclear Medicine of Znojmo Hospital f.o, secured in accordance with the applicable legislation.
192

Υπολογισμός θωρακίσεων ακτινοπροστασίας στην πυρηνική ιατρική / Radiation protection shielding calculations in nuclear medicine

Κρατημένου, Μαρία 07 May 2015 (has links)
Στην παρούσα Μεταπτυχιακή Διπλωματική Εργασία μελετάται το πρόβλημα των θωρακίσεων ακτινοπροστασίας σε τρεις χαρακτηριστικούς χώρους ενός εργαστηρίου Πυρηνικής Ιατρικής, σύμφωνα με τους Κανονισμούς Ακτινοπροστασίας. Οι υπολογισμοί έγιναν με την εφαρμογή λογιστικών φύλλων Microsoft Excel. Ο σκοπός των κάθε είδους θωρακίσεων ιοντιζουσών ακτινοβολιών είναι η μείωση της δόσης της ακτινοβολίας στην οποία εκτίθενται και απορροφούν οι εργαζόμενοι, οι ασθενείς/εξεταζόμενοι αλλά και οι απλοί επισκέπτες σε χώρους ακτινοβόλησης ή γειτονικών, μέσα στα επιτρεπτά όρια. Στην μελέτη αυτή υπολογίζεται το πάχος θωράκισης που χρειάζεται να τοποθετηθεί σε έναν χώρο έτσι ώστε να μην γίνεται υπέρβαση των Περιοριστικών Επιπέδων Δόσεων (Π.Ε.Δ.). Τα πιο κοινά υλικά θωράκισης είναι ο μόλυβδος, το μπετό/σκυρόδεμα και ο σίδηρος. Ο πρώτος χώρος περιέχει ένα ραδιοϊσότοπο, μέσα σε κρύπτη, ενώ υπολογίζεται και ο ρυθμός δόσης σε ένα άτομο, το οποίο μπορεί να βρίσκεται είτε μέσα στον ίδιο χώρο είτε σε παρακείμενο. Ο δεύτερος χώρος περιέχει δύο ραδιοϊσότοπα, και υπολογίζεται η συνολική θωράκιση που απαιτείται. Ο τρίτος χώρος είναι ο χώρος αναμονής ενός πραγματικού εργαστηρίου Πυρηνικής Ιατρικής, μέσα στον οποίο μπορούν να υπάρχουν ταυτόχρονα μέχρι επτά ασθενείς, σε κάθε έναν από τους οποίους έχει χορηγηθεί το απαραίτητο ραδιοφάρμακο για την δική του εξέταση. Επιπλέον, λαμβάνεται υπ’ όψιν η ενδοαπορρόφηση σε κάθε ασθενή, θεωρώντας ότι αποτελείται από έναν κύλινδρο (το σώμα) και μια σφαίρα (το κεφάλι). Ο χώρος αναμονής περιβάλλεται από τον διάδρομο, την αίθουσα αιμοληψιών, το θερμό εργαστήριο, το δωμάτιο εφαρμογής και ο χώρος της γ-κάμερας. Η εφαρμογή λογιστικών φύλλων Microsoft Excel επελέγη για την υλοποίηση των υπολογισμών, ούτως ώστε οι εξισώσεις και οι υπολογισμοί να είναι ανοικτοί και εύκολα επαληθεύσιμοι από τον χρήστη. Επιπλέον, το πακέτο Microsoft Excel καθώς και η λειτουργία του είναι ευρέως διαδεδομένα. Ο χρήστης έχει πλήρη έλεγχο σε κάθε παράμετρο του κάθε χώρου, όπως π.χ. διαστάσεις του χώρου, ραδιοϊσότοπο και ενεργότητα, εξέταση, μέγεθος ασθενούς, κατηγορία παρακείμενων χώρων, υλικό θωράκισης κτλ. Η εφαρμογή διαβάζει αυτόματα ό,τι πληροφορίες απαιτούνται (π.χ. Περιοριστικά Επίπεδα Δόσης, Half-Value Layer κτλ.) από τον πίνακα δεδομένων, ο οποίος και αυτός μπορεί να ενημερωθεί ή εμπλουτιστεί από τον χρήστη, και υπολογίζει τις ζητούμενες θωρακίσεις. Τέλος, η εφαρμογή έχει σχεδιαστεί έτσι ώστε να είναι ευέλικτη και να μπορεί εύκολα να χρησιμοποιηθεί για άλλους χώρους και εργαστήρια, είτε ως έχει είτε με μικρές τροποποιήσεις. / This Master Thesis studies the problem of radiation protection shielding in three typical areas of a Nuclear Medicine Laboratory, in accordance with Radiation Protection Regulations. The actual calculations are performed using the spreadsheet software package Microsoft Excel. The purpose of any type of ionizing radiation shielding is to reduce to within the allowable limits the dose of radiation that workers, patients and ordinary visitors are exposed to and absorb either in radiation areas or in adjacent ones. In this study the thickness of shielding which needs to be placed in an area so as not to exceed the Dose Constraints is calculated. The most common shielding materials are lead, concrete and iron. The first area contains a radioisotope within a crypt, and the dose rate is calculated to an individual, who may be located either within the same room or in an adjacent one. The second area contains two radioisotopes, and the required total shielding is calculated. The third area is the waiting room of an actual Nuclear Medicine laboratory, in which up to seven patients, each of whom has been administered the necessary radiopharmaceutical for his examination, can exist simultaneously. The internal absorption of each patient is taken into account, modeling the patient as consisting of a cylinder (the body) and a sphere (the head). The waiting room is surrounded by a corridor, the blood sampling room, the hot lab, the radionuclide administration area, and the gamma camera area. The spreadsheet application Microsoft Excel was chosen for the implementation of the calculations, so that the equations and calculations be open and easily verifiable by the user. In addition, Microsoft Excel and its use are widespread. The user has full control over every aspect of each area, e.g. dimensions of space, radioisotope and activity, examination, patient size, category of adjacent area, shielding material etc. The application automatically reads the required information (e.g. Dose Constraints, Half-Value Layer etc.) from the data table, which may also be updated and enriched by the user, and calculates the required shielding. Finally, the application is designed to be flexible and can easily be used for other areas and laboratories, either as it is or with minor modifications.
193

Avaliação da exposição ao sup(222)Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR)

ALBERIGI, SIMONE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:00Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
194

Medical use of radiation in gastroenterology:optimising patient radiation exposure during endoscopic retrograde cholangiopancreatography (ERCP)

Saukko, E. (Ekaterina) 04 December 2018 (has links)
Abstract Fluoroscopically guided procedures are currently an area of special concern in relation to radiation protection, as they may produce a high radiation dose to patients and increase the risk of skin injury. ERCP is a gastrointestinal procedure used as a gold standard in the treatment of pancreatobiliary disorders. It is performed under endoscopic and fluoroscopic guidance. Recently, both the number and the complexity with associated increased technical difficulty of therapeutic ERCP procedures have significantly increased. The present study aimed to assess the medical use of radiation in ERCP, with special emphasis on optimisation of radiation protection of patients. For this purpose, the level of patient radiation exposure during ERCP was evaluated by registering the radiation dose indices in Finnish hospitals. The entrance surface dose was measured by thermoluminescent dosimeters and the effective dose was estimated using conversion coefficients. For dose optimisation and for quality assurance, the local diagnostic reference levels (DRL) for ERCP were established and reviewed after five years. A single centre prospective analysis was conducted to identify patient-, procedure- and operator-related factors affecting dose area product (DAP) and fluoroscopy time (FT). The results showed a large variation of dose indices in overall, as among participating hospitals due to differences in patient characteristics, operator, equipment and procedural complexity. The risk of radiation-induced skin injury and the lifetime cancer risk seems to be reasonably low, indicating ERCP to be a low-dose study. Local DRL is an effective tool in the optimisation process, as a certain degree of dose reduction was achieved during the years. Multiple factors were found to affect DAP and FT in ERCP. The awareness of these factors may help to predict possible prolonged procedures that cause a higher radiation dose to the patient and thus facilitate the use of appropriate precautions. / Tiivistelmä Säteilysuojelun näkökulmasta läpivalaisuohjauksessa tehtävät toimenpiteet ovat erityisen huolen aiheena, koska ne voivat aiheuttaa potilaille suuria säteilyannoksia ja siten lisätä ihovaurion riskiä. ERCP on ruoansulatuskanavan endoskopiatoimenpide, jota käytetään haima- ja sappitiesairauksien hoidossa kultaisena standardina. ERCP suoritetaan duodenoskoopilla läpivalaisukontrollissa. Viime vuosina ERCP toimenpiteiden määrät ja toimenpiteiden monimutkaisuus ovat kasvaneet merkittävästi lisääntyneen teknisen haastavuuden vuoksi. Tutkimuksen tarkoituksena oli arvioida säteilyn lääketieteellistä käyttöä ERCP:ssa, kiinnittäen eritystä huomiota potilaan säteilysuojelun optimointiin. Potilaan säteilyaltistuksen tasoa ERCP:ssa arvioitiin keräämällä potilasannoksia suomalaisista sairaaloista, pinta-annokset mitattiin termoloistedosimetreilla ja efektiivinen annos laskettiin muuntokertoimilla. Säteilyaltistuksen optimointi- ja laadunvalvonnan työkaluksi ERCP:lle asetettiin paikalliset vertailutasot ja ne tarkistettiin 5 vuoden kuluttua. Potilaaseen, toimenpiteeseen ja toimenpiteen suorittajaan liittyvät tekijät, jotka vaikuttavat annoksen ja pinta-alan tuloon (DAP) sekä läpivalaisuaikaan, selvitettiin retrospektiivisesti yhdessä sairaalassa. Tutkimuksen tulokset osoittivat, että potilaan säteilyannoksissa oli suurta vaihtelua niin yleisesti, kuin osallistuvien sairaaloiden välillä. Vaihtelu johtui potilaan ominaisuuksista, erilaisista läpivalaisulaitteista, toimenpiteen suorittajista ja ERCP toimenpiteiden vaikeusasteesta. Säteilyn aiheuttaman ihovaurion riski ja elinikäinen syöpäriski näyttäisi tulosten perusteella olevan kohtuullisen alhainen, mikä osoittaa, että ERCP on matala-annostutkimus. Paikallinen vertailutaso osoittautui tehokkaaksi optimointityökaluksi, sillä annostason lasku ERCP:ssa saavutettiin vuosien kuluessa. Useiden tekijöiden todettiin vaikuttavan DAP:n ja läpivalaisuaikaan ERCP:ssa. Näiden tekijöiden tiedostaminen voi auttaa tunnistamaan etukäteen ne haastavat ERCP toimenpiteet, jotka voivat aiheuttaa suuria säteilyannoksia potilaille, ja siten mahdollistaa niihin varautumisen.
195

Aktivace kolimačního systému lineárního urychlovače fotonovým zářením a její vliv na dávky obdržené personálem. / Activation of collimating system of linear accelerator through photon radiation and its impact on the doses received by the staff.

KUBÍKOVÁ, Adéla January 2017 (has links)
The diploma thesis on the topic "Activation of Collimating System of Linear Accelerator through Photon Radiation and its Impact on the Doses Received by the Staff" is divided into two parts, a theoretical and a practical part. The introductory theoretical part is devoted to the basic information about ionizing radiation. What are the types of ionizing radiation, its characteristics, properties and sources of ionizing radiation. Furthermore, there are mentioned direct and indirect interactions of ionizing radiation, a brief description of charged particle accelerators, collimator systems and radioisotope irradiation devices. Another part deals with radiation protection, basic legislation, methods and principles of radiation protection, personal dosimetry and medical supervision of radiation workers. Literary sources, available internet links and valid legal regulations were used for the work. In the practical part, a number of measurements were carried out to measure and to analyse the doses of secondary radiation of the linear accelerator collimator system for different photon beam energies, depending on time, distance from source, position of radiologic assistant around the table when working with the patient, as well as sizes of irradiated field. The aim of the work was to find out how large the doses of secondary radiation are, although measurable, but their values are not sufficient to be detected by personal dosimeters of radiological assistants. Confirm the hypothesis that the doses from the secondary radiation of the linear accelerator collimator system are so low that the dose power does not exceed 0.031 mGy/hr. The results obtained from various measurements are processed into transparent tables and graphically displayed. Based on the results of the measurements, the hypotheses were confirmed.
196

Posouzení zajištění radiační ochrany v DIAMO, státní podnik / Assesment of radiation protection in DIAMO state enterprise

ŠIMÁČKOVÁ, Eva January 2017 (has links)
The importance of possible consequences of radiation, possible health hazard of people and the radionuclide contamination of the environment requires securing radiation protection from the very start of any operation, where radioactive substances are being handled with. One of these fields is the uranium industry in which DIAMO, state enterprise, takes an important position, dealing with the extraction and treatment of uranium, effacing the impacts of mining, remediation and disposal. Findings in the field of uranium industry are primarily won in form of research of professional information sources. In the theoretical part of the work, historical data about the founding and development of the organisation DIAMO, state enterprise, about carried out operations and the affect on the environment are being listed. Furthermore, information concerning radiation protection, its history, principles and measures are being elaborated. On the basis of carried out analysis and gauging results the level of secured radiation protection in DIAMO, state enterprise, is being assessed. Comparing the analysis of currently valid legal regulations to the analysis of safety documentation worked out in DIAMO, state enterprise, the fulfilment of requirements of legal standards is being assessed. In areas affected with uranium industry (Příbram, Stráž pod Ralskem, Mydlovary) gauging the dose equivalent power consupmtion of gama radiation has been carried out. In selected sites water and soil samples have been taken to assess the concentration of radionuclides. The results of the research are being compared to the measuremet results from other sources. In conclusion it is possible to state that the results in the carried out research are comparable to the results of similar researches carried out in other countries.
197

Aktivní částice na ETE, jejich radiobiologická rizika a způsoby ochrany proti nim / Active Particles at the Temelín NPP, Radiobiological Risks and Protective Precautions

KAŇKOVSKÝ, Josef January 2007 (has links)
Active Particles at the Temelin NPP, Radiobiological Risks and Protective Precautions The term active particle (AC) was applied on Temelín NPP (ETE) in order to denominate small fragments of high radioactive matters, sized up to 1 millimeter, forming into primary circuit. In accordance with latest available know-how, the ACs major contains corrosion products, that were activated during passing through reactor core. After primary circuit opening, due to carry out outage works, the ACs will spread into ETE radiation controlled area. In proportion to their size, the ACs activity is relative high, so that the ACs can jeopard workers, who will contact them. This jeopardy is namely associated with AC penetration into organism - ingestion or inhalation. The main goal of this dissertation is to determine grounds of ACs occurence in Temelín NPP, to review ACs radiobiological risks and to evaluate procedures and protective aids, used for assurance of workers radiation protection. This dissertation is resuming actual know-how about ACs occured and occuring in Temelín NPP, including suggestions for radiation protection procedures and for protective aids utilization, that are to be used for reduction of above mentioned jeopardy. Next areas are concerned: - analysis of ACs forming and matters composition - description of ACs physical-radiation parameters - identification of main ACs sources in primary circuit - assesment and evaluation of radiobiological jeopardies, associated with ACs occurence in Temelín NPP radiation controlled area - assesment of procedures and protective aids used for protection of workers, who can be endangered by ACs
198

An investigation of the database systems for the management of radiation sources

Ngubane, Mkhuliseni 27 January 2014 (has links)
The purpose of this study was to evaluate the effectiveness of the database system used at the South African Radiation Control Authority and compare it with RAIS (Regulatory Authority Information System). A radiation regulatory authority requires an adequate and effective data management system in order to carry out its regulatory control program efficiently and effectively. RAIS is a comprehensive system that includes all of the main functionality required to support a regulatory framework. A mixed methods approach, including a quantitative descriptive comparative evaluation research study was conducted to determine if the database system currently used by the South African Radiation Control Authority is effective as a data management tool for a regulatory body. Two analyses were conducted. Firstly, the specification records of the South African database system were compared with that of RAIS. Secondly, current database users were surveyed by means of a structured questionnaire. Both analyses reveal that RAIS performs better than the Radiation Control database in the main areas of the regulatory framework. The study results also highlight some of the shortcomings and strengths of the Radiation Control database / Medical Informatics / M.A. (Public Health)
199

Měření osobních dávek pacientů v radioterapii mimo centrální svazek ionizujícího záření pomocí elektronického osobního dozimetru / Measurement of patients´ personal doses in radiotherapy outside the central beam of ionizing radiation using the electronic personal dosimeter

CHYLÍKOVÁ, Renáta January 2013 (has links)
The introductory part of the diploma thesis primarily focuses on the history of radiotherapy, i.e. what it emerged from and how it developed, as it is one of the most important fields in medicine, especially because thousands of people are irradiated every day due to different tumour and non-tumour diseases. Another reason why ionizing radiation is described is the fact that it is a necessary part of tumour disease irradiation. Ionizing radiation is also connected with radiation protection. This section presents a historical overview of radiation protection, as well as principles and quantities of this field. Furthermore, it focuses on Czech acts, decrees, and government regulations which define various measures governing this issue. Radiation protection forms the basis of patient, workplace, and personnel monitoring. All this is connected with the measurement and evaluation of received personal doses. This brings the thesis to the field of dosimetry, therefore various dosimeters used in practice are described. The aim of this diploma thesis is the measurement of patients? personal doses in head and neck irradiation using the electronic personal dosimeter at the radiotherapy centre of Nemocnice České Budějovice, a. s. The thesis is based on the question of whether irradiation doses that patients with head and neck tumours receive outside the primary radiation beam are negligible. The theoretical part of the thesis uses all available resources from both foreign and Czech literature. The practical part is based on numerical statistics, i.e. a quantitative method. The research was carried out at the radiotherapy centre of Nemocnice České Budějovice, a. s. Irradiation of patients with head and neck tumours was performed on a linear accelerator. Each patient had a mask to which an electronic personal dosimeter was attached during irradiation. Using this dosimeter, it was possible to measure doses received outside the central radiation beam. The measured values were then used to carry out assessment using formulas. Patients who undergo cancer treatment receive relatively high doses of radiation, so my main goal was to measure personal dose equivalents at the reference point. When comparing the percentage of the number of examinations with the web portal Epidemiology of Malignant Tumours in the Czech Republic, it was found that irradiation of the neck is more frequent than irradiation of the head. The total values of personal dose equivalents are relatively high in each patient, but because it is medical treatment, these values are not subject to radiation exposure limits. The comparison of the irradiated areas shows that irradiation of the neck has small values of personal dose equivalents to 1Gy compared to irradiation of the head.
200

Měření fotonů pomocí elektronických dozimetrů při urychlování nabitých částic na Fyzikálním ústavu AV ČR v Praze / Measurement of photons via electronic dosimeters for the acceleration of charged particles at the Institute of Physics ASCR in Prague.

ŽIDKOVÁ, Jana January 2014 (has links)
The thesis is focused on summarizing the current issue of work with experimental lasers in the research center of Prague Asterix Laser System (PALS), which falls under the Institute of Physics and Institute of Plasma Physics. Experimental lasers used for experimental research in the field of powerful laser physics and laser-produced plasma. The main experimental facility PALS is a powerful pulsed laser system Asterix IV., The research center was purchased from the German Max Planck Institute for quadratic Optics in Garching near Munich for a symbolic 1 mark. Asterix is one of the three largest iodine lasers in Europe. Between the research programs being carried out on the experimental development of lasers include applications of plasma point sources of soft non-coherent radiation, development and application of laser plasma X-ray etc. Other facilities located in the research center include PALS laser system Ti - Sapphire power of 25 terawatts. In this system, a similar experiment was performed measuring photon film dosimeters. The experimental laser Asterix IV in the research center PALS have been no experiment with film or electronic dosimeters. This work deals with the possibility of using electronic personal dosimeters when working with lasers and detection sensitivity of the dosimeters, unlike other types of personal dosimeters. This was achieved by measuring the two independent measurements ongoing at the Asterix IV laser system. Possibilities of using electronic personal dosimeters for measuring the pulse field, even though they are designed to measure benefits only in the continuous field is particularly important for workers newly built ELI center in Prague. Center ELI will be the most modern laser equipment in the world. In it will be carried out the research and application projects involving the interaction of light with matter in intensity, which is about 10 times larger than the currently achievable. ELI will deliver ultrashort laser pulses lasting typically a few femtoseconds (10-15 fs) and produce power up to 10 PW. The ELI Center will be unlike PALS controlled area in which it is important to monitor external radiation workers. Therefore, the thesis is aimed at providing support for PALS measurement using electronic personal dosimeters Center ELI. We also compare the sensitivity of the most common types of personal dosimeters such as film and thermoluminescent dosimeters. In the theoretical part of the description and principle of laser Asterix IV. Furthermore, the definition of ionizing radiation and its species with a particular focus on gamma and X-rays. In this thesis remains missing definitions such as dosimetry, types of dosimeters, monitoring, radiation protection and value to it. In the methodology are then analyzed measurements that were carried out in two experiments using electronic personal dosimeters, film dosimeters and thermoluminescent dosimeters. Furthermore, also the deployment of the laser system, focusing mainly on the description of the interaction of the hall and the interaction chamber, where were measured. The methodology is also a series of photos of photos taken at the workplace PALS for easier orientation. In the results, the values of individual measurements recorded for better clarity in the tables and charts described. The discussion is focused on the confirmation of hypotheses. Are compared to results from electronic and film dosimeters and electronic dosimeters and termoluminescent. Results are based on one shot and statistically processed. In the event of a general summary of the work, it is recommended the use of electronic personal dosimeters to work with experimental lasers and supported the intention of the use of electronic personal dosimeters in the newly built Center ELI in Prague, mainly because of higher sensitivity than that with film and TLD and also for easier, faster, and economical evaluation of the benefits.

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