Dissertations / Theses on the topic 'Radiation safety'
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吳楚儀 and Chor-yi Ng. "Radiation hazards of building materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B3121051X.
Full textCorder, David A. "An instrumentation strategy for laser radiation safety assessments." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/13972.
Full textCordero, J. S. "Radiation model for buoyant flames." Thesis, University of Sheffield, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264618.
Full textDong, Xiuqin. "Safety limit estimation for cataract induced by ultraviolet radiation /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-451-1/.
Full textNicholson, Richard. "Radiation sensor interface ASSP designed for safety critical applications." Thesis, Lancaster University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497766.
Full textCampos, Carlos Austerlitz. "Choice of personnel dosimeter location to assess the effective dose equivalent for various photon irradiations." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12916.
Full textVeinot, Kenneth Guy. "An angular dependent neutron effective-dose-equivalent dosimeter." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/17595.
Full textElmukhtar, Yasir Mohamed. "Knowledge and attitude of dentists regarding radiation safety in government dental clinics in Khartoum, Sudan." University of the Western Cape, 2015. http://hdl.handle.net/11394/5037.
Full textThe level of knowledge and the attitude of dentists regarding radiation safety will have a direct impact on patient exposure to radiation. Aim: The aim of the present study was to evaluate the knowledge and attitude of dentists regarding radiation safety in government dental clinics in Khartoum, Sudan. Materials and Methods: A cross-sectional study using an administered structured questionnaire was carried out. The questionnaire consisted of 13 questions that included the demographic data of dentists, basic knowledge regarding radiation safety, knowledge of methods of dose reduction and the attitude of dentists regarding radiation safety. One hundred and sixty seven dental practitioners participated in the study. Results: The response rate was 90%. The majority were female, 59%, in the age group younger than 29 years with clinical experience less than 10 years. Only fifteen of the respondents identified themselves as specialist. Half of the respondents did not know that the thyroid gland is the most radiosensitive organ in the head and neck region. Forty four percent believed that the dose for panoramic radiography was higher than that for full mouth periapical radiographs. Forty percent had no idea that a relationship exists between the length of the x-ray cone and the amount of the dose and 44% who knew that the relationship existed, failed to explain that the long cone is more effective for reducing the patient dose. Forty seven percent of the respondents had no idea that there is a relationship between the speed of the film and the amount of dose and 44% who knew that the relationship existed, failed to explain that the fast film is more effective for reducing the patient dose. Sixty six percent had no idea that a relationship exists between collimation of the x-ray tube and patient dose. Forty six percent who knew the relationship existed, failed to explain that rectangular collimation is more effective for dose reduction. Seventy two percent of the dentists did not know what a safe distance from the radiation source was. Forty seven percent did not use film holders when taking periapical radiographs. Conclusions: This study clearly illustrates that there is a lack of knowledge regarding radiation safety in dentists in the government dental clinics in Khartoum, Sudan. Therefore there is a need to increase their knowledge regarding methods of radiation dose reduction (to patient) as well as improving their attitude regarding the radiation safety.
Rhodes, Charles Ray III. "Development of an Automated Program for Calculating Radiation Shielding in a Radiotherapy Vault." University of Toledo Health Science Campus / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=mco1331557547.
Full textShika, Matsepane Rebecca. "Radiation safety standards at public hospitals in Limpopo Province, South Africa." Thesis, University of Limpopo (Turfloop Campus), 2012. http://hdl.handle.net/10386/859.
Full textJalandoni, D. Jay Moreno. "In-phantom measurement of HE or neutron protection dosimetry." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/16777.
Full textReynolds, Patricia Ann. "An investigation into the safety of low level laser irradiation." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243560.
Full textESPOSITO, JANA C. G. "Instalações e uso seguro de lasers odontológicos." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9926.
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Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia)
IPEN/D-MPLO
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de São Paulo, São Paulo
Aldridge, Jesse Philmore. "The role of health physicists in contemporary radiological emergency response." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/19434.
Full textGriffis, Neale Jeff. "Performance evaluation of the Dosicard electronic personal dosimeter." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/16991.
Full textKharkov, E., and N. Karaeva. "Automation of electromagnetic radiation monitoring as the factor of ecological safety maintenance." Thesis, Видавництво СумДУ, 2008. http://essuir.sumdu.edu.ua/handle/123456789/11741.
Full textSalikin, Md Saion. "An improved system of damage limitation for better risk control in radiological protection near environmental level." Thesis, University of St Andrews, 1995. http://hdl.handle.net/10023/13372.
Full textPANSINI, MARIO. "Avaliacao de requisitos de seguranca em lasers terapeuticos de baixa intensidade." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10971.
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Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia)
IPEN/D-MPLO
Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo
Fulcher, TJ. "The development of an interlock and control system for a clinical proton therapy system." Thesis, Cape Technikon, 1995. http://hdl.handle.net/20.500.11838/1483.
Full textThe development of a 200 MeV clinical proton therapy facility at the National Accelerator Centre required an interlock and control system to supervise the delivery of radiation to a patient. The interlock and control system is responsible for ensunng that nobody enters the treatment vault during an irradiation, the extraction of the beamstop devices 'from the beam-line to allow the irradiation of the patient and the insertion of those beam-stop devices when an error condition is detected. Because of its nature, the interlock and control system should be designed so that in the event of an error condition being detected, it should fail to a safe state. This is achieved by modelling the interlock and control system with an appropriate modeling method. This thesis describes a graphical modelling method called Petri-nets, which was used to model the system, and the software developed from the model.
Witzel, Joy. "Operational and radiation safety guidelines for hand held intraoral x-ray systems a thesis /." San Antonio : UTHSC, 2008. http://learningobjects.library.uthscsa.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=21&CISOBOX=1&REC=11.
Full text陳木華 and Mok-wah Chan. "Exposures to artificial sources of ionising radiation in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31208496.
Full textZakariya, Nasiru Imam. "Development of nuclear-radiological facility monitoring system." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2182.
Full textThe widespread application of nuclear science and technology has been the subject of much concern as well as nuclear safety issues. And to ensure the safety of public life, property and environment, it is indispensable to improve the emergency system for nuclear accidents and the environmental monitoring system for nuclear radiation, so that the occurrence of nuclear accidents, terrorist incidents and the resulting hazards can be prevented or minimized. Due to the benefits of radiation which were earlier and now recognized in the use of X-rays for medical diagnosis and then later with the discoveries of radiation and radioactivity, there was rush in exploiting the medical benefits which eventually led fairly to the recognition of the risks and induced harm associated with it. Thus, only the most obvious harms resulting from high doses of radiation, such as radiation burns, were initially observed and protection efforts were focused on their prevention, mainly for practitioners rather than patients. Subsequently, it was gradually recognized that there were other, less obvious, harmful radiation effects such as radiation-induced cancer, for which there is certain risk even at low doses of radiation.
Weaver, Bess A. "Solar Ultraviolet Radiation Exposure in Outdoor Work Environment at Bowling Green, Ohio." University of Toledo Health Science Campus / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=mco1211995092.
Full textWatson, Jennifer A. "Designing, implementing, and conducting a Web-based radiation safety training program for a large biomedical research institution : a thesis /." San Antonio : UTHSC, 2008. http://learningobjects.library.uthscsa.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=22&CISOBOX=1&REC=5.
Full textMitsuyoshi, Takamasa. "A pilot study on the safety and efficacy of dose escalation in stereotactic body radiotherapy for peripheral lung tumors." Kyoto University, 2018. http://hdl.handle.net/2433/232115.
Full textBoland, Joseph B. "The Cold War legacy of regulatory risk analysis : the Atomic Energy Commission and radiation safety /." view abstract or download file of text, 2002. http://wwwlib.umi.com/cr/uoregon/fullcit?p3055670.
Full textTypescript. Includes vita and abstract. Includes bibliographical references (leaves 665-706). Also available for download via the World Wide Web; free to University of Oregon users.
Johnson, Paul G. "EVALUATION OF FLUOROSCOPY RADIATION WORKER EXPOSURE AT A LARGE MEDICAL CENTER: IMPLICATIONS FOR UTILIZING GRAPHICAL FEEDBACK INFORMATION FOR IMPROVING OCCUPATIONAL SAFETY." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1523631347981258.
Full textSavičiūtė, Rasa. "Medicinos personalo (gydytojų radiologų ir radiologijos laborantų), informuotumo apie gaunamą pacientų apšvitą ir radiacinę saugą tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2008~D_20101125_185247-37918.
Full textMain task – to estimate and evaluate medical personnel’s of health care (doctors of radiology and radiology assistants) informativeness about receivable irradiance towards patients and radiational safety in city of Vilnius. Object of research - doctors of radiology and radiology assistants. During this research 140 respondents were questioned from 15 health care institutions. Overall 35 radiologists were questioned (15 men and 20 women), 105 radiology assistants (4 men and 101 women) and that’s accordingly 20, 0% and 75, 0%. Age variance of the respondents is from 23 up to 71 years old (average of 47.43 years old). Descriptive research type and survey was used in order to achieve the goals of this research. Statistical data analysis was performed by using SPSS program, version 13. The given distribution of index is in natural numbers and in percentage, Chi-square is counted (Chi-sq). Statistically the difference is meaningful when the level of probability is p<0,05. The analysis of science articles, law normative materials, health care systems, etc. was accomplished. The conclusion: after the evaluation of knowledge of the respondents it is clear that, doctors of radiology and radiology assistants have enough knowledge about radiational safety and dangers of irradiance. The research also revealed that they do not have enough knowledge concerning the specific topics, for example the doses that are received during variable procedures, the dependence of the dose, the observation... [to full text]
Ho, Wing-kwok, and 何永國. "Solar ultraviolet radiation: monitoring, dosimetry and protection." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31222675.
Full textMurray, Bryon Michael. "Determination of eye dose from personnel monitoring devices in medical institutions." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17040.
Full textGlassford, Eric. "Comparison of Grab, Air, and Surface Results for Radiation Site Characterization." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307442130.
Full textVan, der Walt Jacobus Gert. "Radiation field shaping through low temperature thermal-spray in radiotheraphy." Thesis, Bloemfontein : Central University of Technology, Free State, 2009. http://hdl.handle.net/11462/116.
Full textSuperficial cancerous lesions are commonly treated through low energy X-ray or electron radiation in radiotherapy. The treatment units that produce the radiation are equipped with square, rectangular and round applicators of different sizes. These applicators attach to the treatment units and define the radiation field size applied during treatment. An applicator is chosen to fit the shape of the cancerous lesion on the patient as closely as possible. Since cancerous lesions are irregular in shape, there will always be an area of healthy tissue between the edge of the lesion and the edge of the standard field shape. This healthy tissue will be irradiated along with the lesion during treatment which is undesirable since the cancer wound heals through reparative growth of the surrounding healthy tissue after treatment. Traditional techniques that were developed to shield this healthy tissue and thus shape the radiation field to the shape of the lesion present various shortcomings. This study introduces a new thermal-spray process for producing radiation field shaping shields which overcomes most of the shortcomings encountered with the traditional field shaping techniques. Since none of the commercially available thermal-spray equipment could be used to produce field shaping shields, new thermal-spray equipment was designed and fabricated tailor made to the application. Different techniques to determine the contours of the treatment area on the patient were investigated. These included a patient contact technique using a plaster bandage impression and a non-contact technique using 3D laser scanning. From the plaster bandage impression a plaster model can be produced onto which a high density low melt material such as Wood’ s alloy can be thermally sprayed to produce a field shaping mask. A model can also be produced from the 3D laser scanning data through laser sintering (LS) in nylon polyamide powder or through computer numerical controlled (CNC) milling in a block of low density polyurethane. The thermal-spray technique was evaluated by comparing the field shaping ability of radiation shields produced through the technique to the field shaping ability of shields produced through the traditional techniques. Radiographic film was used for this purpose and the results are presented in the form of isodensity charts. The required thicknesses of thermal-sprayed field shaping masks to shield radiation of various energies were also determined. The thicknesses were determined through radiation transmission measurements of known thicknesses of sprayed sheets of Wood’ s alloy. X-ray imaging showed that there were no defects present within thermal-sprayed layers of Wood’ s alloy that may negatively affect the shielding ability of masks produced through the technique.
Housenick-Lee, Megan. "Social-Ecological Factors Affecting Patient Shield Use Among Radiologic and Computed Tomography Technologists." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etd/3321.
Full textGarvin, Theresa Dawn. "Evidence, policy and practice in environmental health : an international case study of sun safety /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0033/NQ66209.pdf.
Full textGhassemi, Hamed 1964. "Design and simulation of an improved operational amplifier for use in radiation environments." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276987.
Full textAnderson, Anne Lee. "Assessment of thermal radiation arithmetic's for jet flames : A study involving generic calculation methods concerning radiation from jet flames with the purpose to determine the safety distance for flame effects." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67173.
Full textWentling, II William A. II. "Economic Effects on Radiopharmacy Systems| The Impact of the Nuclear Regulatory Commission's Proposed Radiation Exposure Limits." Thesis, Robert Morris University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3629877.
Full textIn the spring of 2012, based on recommendations from the International Commission on Radiological Protection (ICRP), the Nuclear Regulatory Commission (NRC) proposed three amendments to reduce current radiation exposure limits for radiation workers. The NRC proposals have caused some concern within the radiopharmaceutical industry. The regulatory changes may affect the ability of radiopharmacy workers to remain on the job, thereby inflicting additional costs to radiopharmacies if they are required to replace workers who have reached their yearly exposure limits.
This research sought to determine whether or not the new regulatory proposals will in fact have a financial impact on the radiopharmaceutical industry. This research was a retrospective case study that analyzed four radiopharmaceutical production facilities and their employee radiation exposure reports. Results of the study suggest that the NRC's proposed amendments to reduce radiation levels will not have a great adverse effect, either financially or from an employee exposure standpoint, on the current radiopharmacy system. The research demonstrated that existing as low as reasonably achievable (ALARA) standards have resulted in radiopharmacy workers receiving exposures well below the current limits, and within the NRC proposed limits. Of 77 employees studied over a 10 year period, only seven employees (9 %) would have been removed from the production process for overexposure to any one of the NRC's proposed limits. However, this research reviewed small a subset of four radiopharmacies and did not examine other industries and professions utilizing ionizing radiation.
Mngxekeza, Siyabulela. "Realising the right to the highest attainable standard of health in the nuclear industry." University of the Western Cape, 2019. http://hdl.handle.net/11394/6974.
Full textAfrican states are interested in the development of nuclear power (also referred to as atomic power) for the generation of electricity and desalination. These include Algeria, Egypt, Ghana, Kenya, Morocco, Namibia, Niger, Nigeria, Tunisia, South Africa, and Uganda. The nuclear governance in South Africa has adopted principles into its legal system which require it to comply with the objectives of numerous resolutions, conventions, treaties, bilateral and multilateral agreements. Therefore, there is an obligation upon the government through ‘reasonable legislative and other measures’ to manage nuclear matters, such as nuclear accidents, in a manner that protects the general public, atomic industry workers as well as prevents the pollution of the surrounding environment. It has been seven years since the Fukushima Daiichi Nuclear Power Plant Accident that occurred in Japan on 11 March 2011, when considerable amounts of radioactive material from the damaged plant released into the environment. Health hazards, associated with exposure to low levels of ionising radiation, are a significant concern following such an accident. A nuclear disaster can potentially violate not only the right to health of workers, but that of residents and evacuees alike, particularly pregnant women, older persons, and children. Regional and international human rights conventions impose obligations on state parties to “take whatever steps necessary to ensure that the right to the highest attainable standard of health is enjoyed by all as soon as possible”. In most cases, when a nuclear accident occurs, workers within the nuclear plant are expected to mitigate emergencies. The danger of this expectation is that it could violate their fundamental human rights.
Niemi, A. (Antti). "Röntgenhoitajien turvallisuuskulttuuri säteilyn lääketieteellisessä käytössä—Kulttuurinen näkökulma." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514282949.
Full textTiivistelmä Tutkimuksen tarkoituksena oli kuvailla ja tulkita röntgenhoitajien turvallisuuskulttuuria säteilyn lääketieteellisessä käytössä. Tavoitteena oli tuoda esille aineistolähtöisesti röntgenhoitajien turvallisuuskulttuurin erityispiirteet ja tuottaa uutta tietoa siitä. Aineisto kerättiin kahdesta eri yliopistosairaalan ja yhdestä keskussairaalan hoito-organisaatiosta. Aineisto koostuu tiedonantajien haastatteluista (n=20), kenttätyöstä (yhteensä 2 kuukautta), ammattilehtien artikkeleista (n=457) sekä röntgenhoitajien työssään käyttämistä dokumenteista (n=21). Turvallisuuskulttuurin jaettujen merkitysjärjestelmien tulkitsemiseksi sovellettiin tulkinnallisen ja kognitiivisen kulttuurintutkimuksen metodologisten lähtökohtien perustalta kohdennettua etnografista lähestymistapaa sekä diskurssianalyysia. Röntgenhoitajien turvallisuuskulttuuri säteilyn lääketieteellisessä käytössä muodostui neljästä jaetusta merkitysjärjestelmästä: osaamisen haasteet turvallisuuskulttuurin jäsentäjänä, yhteistyön ulottuvuudet turvallisuuskulttuurin mahdollistajana, hämmennys turvallisuuskulttuurin ehdollistajana sekä moniulotteinen ammatillisuus turvallisuuskulttuurin perustana. Tekniikan hyväksikäyttö nähtiin olennaiseksi osaksi röntgenhoitajan työtä, jolla vaikutetaan potilaan saamaan hoitoon. Perinteistä, sairaanhoitajan työhön perustuvaa hoitotyötä ei pidetty röntgenhoitajan omaan tehtävään kuuluvana. Yhteistyöhön vaikuttivat röntgenhoitajien monipuolistuneet tehtävät, perinteiset näkemykset röntgenhoitajien, osastonhoitajien ja lääkäreiden tehtävistä ja rooleista sekä vastaaminen nykyisen työelämän yhteiskunnallisiin haasteisiin. Uuden teknologian nopea tuleminen röntgenhoitajan työhön edellytti tietojen ja taitojen jatkuvaa ylläpitämistä ja kehittämistä. Röntgenhoitaja oli säteilysuojelijan roolissa suhteessa potilaisiin, muihin röntgenhoitajiin ja toimintaympäristöön. Säteilysuojelu nähtiin tärkeäksi osaksi röntgenhoitajan vastuullista toimintaa. Säteilysuojelun merkitystä korostettiin ja sitä pidettiin keskeisenä tekijänä röntgenhoitajan ammatissa. Röntgenhoitajia kuitenkin hämmensivät erilaiset ohjeistukset ja käytännöt säteilysuojelun toteuttamisessa. Tutkimustuloksia voidaan hyödyntää röntgenhoitajan työn kehittämisessä, koulutuksessa ja työn organisoinnissa. Tulokset voivat auttaa myös selkeyttämään turvallisuuskulttuuria ilmiönä ja käsitteenä säteilyn lääketieteellisessä käytössä. Tutkimuksen teoreettisia ja metodologisia ratkaisuja voidaan soveltaa myös muissa terveystieteellisissä tutkimuksissa
Seydaliev, Marat Radikovich. "Development and Test of a GEM-Based TEPC for Neutron Protection Dosimetry." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14607.
Full textBRAGA, FLAVIO H. "Avaliacao de requisitos de seguranca e um equipamento a laser de erbio para fins odontologicos." reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10964.
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Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia)
IPEN/D-MPLO
Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo
CAMPOS, FABIO E. de. "Desenvolvimento de um modelo de cela para processamento de radiofarmacos injetaveis." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9511.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Pollock, Allison Maureen. "Characterization of pulsed light treatment on the shelf-life and safety of vacuum packaged cold smoked salmon." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101165.
Full textPulsed light destruction kinetics of L. monocytogenes were evaluated while dispensed into a liquid media, on the surface of a general purpose agar and on the surface of cold smoked salmon. Results showed that PL technology was an effective surface sanitation method (a decimal reduction time or D-value of 0.91, 1.37 and 2.25 s exposure of PL at 800, 700 and 600 V, respectively, and a resulting z value of 500 V) on the agar plate. However, it had only a limited success when applied to liquid samples as well as directly on the surface of cold smoked salmon (D-value ranged from 93 s to 24 min).
Sensory quality of VP cold smoked salmon subjected to selected PL treatments was monitored during storage for 14 days at 4°C. Both color and odor scores remained within acceptable limits over the 14 day storage period. Subsequent challenge studies were carried out with L. monocytogenes applied on VP cold smoked salmon. An overall reduction in counts was observed in samples stored at 4°C over 28 days; however, after PL treatment (day 0), there was no significant reduction in counts. Color and odor scores maintained acceptable values over 14 days. Additional experiments were carried out to determine the effects of (1) 1.5% salt, (2) 6% oil, (3) a representative salmon media and (4) background microflora (lactic acid bacteria) on the PL inactivation of L. monocytogenes. All of these factors significantly affected the destruction of L. monocytogenes by increasing the D-value (adding resistance to pulsed light destruction).
Overall, these studies have shown that PL treatment in combination with low temperature storage (4°C) has the potential to extend the shelf-life of VP cold smoked salmon products without compromising sensory quality. However further investigation into higher treatment voltages is necessary in order to achieve a higher target kill of L. monocytogenes.
BARBOZA, ALEX. "Gestao de rejeitos radioativos em servicos de medicina nuclear." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9377.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Peters, Nazlea Behardien. "Determination of effective dose and entrance skin dose from dose area product values for barium studies in adult patients at a large tertiary hospital in the Western Cape." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2627.
Full textBackground and objectives The issue of patient doses received during fluoroscopy procedures, raised concerns for the researcher, as there may have been probable past skin injuries or deterministic injuries that may not have been documented. Amongst the radiology staff, there was very little understanding of what the actual dose area product (DAP) value means in real terms of effective dose and entrance skin dose. The aims of the study were to: i) Measure the radiation doses received by the patient and determine a simple means of defining the DAP value to the radiographer in terms of the dose received by the patient. ii) Determine the effective dose, entrance skin dose and the relationship with the DAP value to assist with developing a conversion co-efficient for dose indicators. Method Direct radiation dose measurements can be obtained through DAP meters attached to the diagnostic equipment, but the DAP value is not an direct indication of the effective dose received by the patient. The DAP values captured from the DICOM header information for barium fluoroscopic procedures at a large tertiary was analysed and Diagnostic Reference levels (DRL) were determined for barium swallow, meal and enema procedures. The effective and skin doses were calculated by means of the Monte Carlo program. The results were compared to published values. The relationship between the entrance skin dose and the DAP value was determined and conversion factors were calculated. Results Correlation between the DAP and entrance skin dose and comparative 75th percentile threshold values were determined for barium swallow (BaS), barium meal (BaM) and barium enema (BaE) procedures. Effective to DAP conversation factors for BaS, BaM and BaE are 0.19, 0.26 and 0.60 respectively and 0.15, 0.11 and 0.14 for entrance skin to DAP. Conclusion The the research showed the relationship between the effective dose, entrance skin dose and DAP value and a simple, practical and applicable explanation of the DAP value by means of conversion factors.
Jorge, Carlos Alexandre Fructuoso. "Received radiation dose assessment for nuclear plants personnel by video-based surveillance." Instituto de Engenharia Nuclear, 2015. http://carpedien.ien.gov.br:8080/handle/ien/1463.
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This work proposes the development of a system to evaluate received radiation dose for nuclear plants personnel. The system is conceived to operate in a complementary form to the existing approaches for radiological protection, thus o ering redundancy, what is desirable for critical plants operation. The proposed system must operate in an independent form on the actions to be performed by the operators under evaluation. Therefore, it was decided it would be based on methods used for video surveillance. The nuclear plant used as example is Argonauta Nuclear Research Reactor, belonging to Instituto de Engenharia Nuclear, Comiss~ao Nacional de Energia Nuclear (Nuclear Engineering Institute, National Nuclear Energy Commission). During this thesis research, both radiation dose rate distribution and video databases were obtained. Methods available in the literature, for targets detection and/or tracking, were evaluated for this database. From these results, a new system was proposed, with the purpose of meeting the requisites for this particular application. Given the tracked positions of each worker, the radiation dose received by each one during tasks execution is estimated, and may serve as part of a decision support system.
Carlsson, Johan. "Inherent Safety Features and Passive Prevention Approaches for Pb/Bi-cooled Accelerator-Driven Systems." Doctoral thesis, KTH, Physics, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3503.
Full textThis thesis is devoted to the investigation of passivesafety and inherent features of subcritical nucleartransmutation systems - accelerator-driven systems. The generalobjective of this research has been to improve the safetyperformance and avoid elevated coolant temperatures inworst-case scenarios like unprotected loss-of-ow accidents,loss-of-heat-sink accidents, and a combination of both theseaccident initiators. The specific topics covered are emergencydecay heat removal by reactor vessel auxiliary cooling systems,beam shut-off by a melt-rupture disc, safety aspects fromlocating heat-exchangers in the riser of a pool-type reactorsystem, and reduction of pressure resistance in the primarycircuit by employing bypass routes.
The initial part of the research was focused on reactorvessel auxiliary cooling systems. It was shown that an 80 MWthPb/Bi-cooled accelerator-driven system of 8 m height and 6 mdiameter vessel can be well cooled in the case of loss-of-owaccidents in which the accelerator proton beam is not switchedoff. After a loss-of-heat-sink accident the proton beam has tobe interrupted within 40 minutes in order to avoid fast creepof the vessel. If a melt-rupture disc is included in the wallof the beam pipe, which breaks at 150 K above the normal coreoutlet temperature, the grace period until the beam has to beshut off is increased to 6 hours. For the same vessel geometry,but an operating power of 250 MWth the structural materials canstill avoid fast creep in case the proton beam is shut offimmediately. If beam shut-off is delayed, additional coolingmethods are needed to increase the heat removal. Investigationswere made on the filling of the gap between the guard and thereactor vessel with liquid metal coolant and using water spraycooling on the guard vessel surface.
The second part of the thesis presents examinationsregarding an accelerator-driven system also cooled with Pb/Bibut with heat-exchangers located in the risers of the reactorvessel. For a pool type design, this approach has advantages inthe case of heat-exchanger tube failures, particularly if wateris used as the secondary uid. This is because a leakage ofwater from the secondary circuit into the Pb/Bi-cooled primarycircuit leads to upward sweeping of steam bubbles, which wouldcollect in the gas plenum. In the case of heatexchangers in thedowncomer steam bubbles may be dragged into the ADS core andadd reactivity. Bypass routes are employed to increase the owspeed in loss-of-ow events for this design. It is shown thatthe 200 MWth accelerator-driven system with heat-exchangers inthe riser copes reasonably well with both a loss-of-ow accidentwith the beam on and an unprotected loss-of-heat-sink accident.For a total-loss-of-power (station blackout) and an immediatebeam-stop the core outlet temperature peaks at 680 K. After acombined loss-of-ow and loss-of-heat-sink accident the beamshould be shut off within 4 minutes to avoid exceeding the ASMElevel D of 977 K, and within 8 minutes to avoid fast creep.Assuming the same core inlet temperature, both the reactordesign with heat-exchanger in the risers and the downcomershave similar temperature evolutions after a total-loss-ofpoweraccident.
A large accelerator-driven system of 800 MWth with a 17 mtall vessel may eventually become a standard size. For thishigher power ADS, the location of the heat-exchangers hasgreater impact on the natural convection capability. This isdue to that larger heatexchangers have more inuence on thedistance between the thermal centers during a lossof- owaccident. The design with heat-exchangers in the downcomers,the long-term vessel temperature peaks at 996 K during aloss-of-ow accident with the beam on. This does not pose athreat of creep rupture for the vessel. However, the locationof the heat-exchangers in the downcomers will probably requiresecondary coolant other than water, like for example oil (fortemperatures not higher than 673 K) or Pb/Bi coolant.
SILVA, JONAS O. da. "Desenvolvimento de câmaras de ionização especiais para controle de qualidade em mamografia." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10507.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Loy, Rodas Nicolas. "Context-aware radiation protection for the hybrid operating room." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD001/document.
Full textThe use of X-ray imaging technologies during minimally-invasive procedures exposes both patients and medical staff to ionizing radiation. Even if the dose absorbed during a single procedure can be low, long-term exposure can lead to noxious effects (e.g. cancer). In this thesis, we therefore propose methods to improve the overall radiation safety in the hybrid operating room by acting in two complementary directions. First, we propose approaches to make clinicians more aware of exposure by providing in-situ visual feedback of the ongoing radiation dose by means of augmented reality. Second, we propose to act on the X-ray device positioning with an optimization approach for recommending an angulation reducing the dose deposited to both patient and staff, while maintaining the clinical quality of the outcome image. Both applications rely on approaches proposed to perceive the room using RGBD cameras and to simulate in real-time the propagation of radiation and the deposited dose
Kotb, Shady. "Safety and radiosensitization properties of theranostic Gadolinium-based nanoparticles AGuIX®." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1330.
Full textCombinations of chemotherapy and radiotherapy are often used to control cancer progression. However, the poor targeting specificity of most chemotherapies and radiotherapies can cause toxicity and ambiguous clinical response. In particular, dose escalation in radiotherapy inevitably increases radiation exposure for some surroundings normal tissues and organs, putting them at risk for debilitating damage. An alternative – and complementary – strategy is the use of materials with high atomic numbers (Z) that strongly interact with low energy photons to produce photoelectrons and Auger electrons In this context, a new efficient type of gadolinium (Gd)-based theranostic agent (AGuIX®) has recently been developed by the team of Prof. Tillement for MRI-guided radiotherapy. AGuIX® is a 3-nm size nanoparticles of 9 kDa, consist of a polysiloxane network surrounded by Gd chelates. In this thesis, we investigated the elimination kinetics of AGuIX nanoparticle’s (NPs) from sub-cellular to whole organ scale using original and complementary techniques. This combination of techniques allows the exact mechanism of AGuIX NPs elimination to be elucidated. We reported the preclinical pharmacokinetics and toxicology studies of intravenous AGuIX NPs administration in healthy and atherosclerosis non-human primates (NHP), the goal of which is to demonstrate the safety of AGuIX NPs, in particular, for pre-clinical evaluation. Subsequently, we performed experimental and theoretical studies to investigate the radiosensitization of AGuIX NPs, in particular with B16F10 mouse melanoma as a model for brain metastases. After, we implemented experimental and theoretical studies to precisely understand the mechanism of this radiosensitization, we suggest additional mechanism, potentially caused by chemical and biological effects induced by the combination of Gd and radiation (i.e. high yield of radicals formation and combination, and bystander effect)