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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.
291

Emprego dos policarbonatos makrofol-de e CR-30 em radiografia com neutrons

PEREIRA, MARCO A.S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:33Z (GMT). No. of bitstreams: 1 11313.pdf: 4364467 bytes, checksum: 80dca67e716c2de36cf87cbbab397c48 (MD5) / Dissertacao (Mestrado) / IPEN/D / Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP
292

Determinacao de defeitos em profundidade (estereoradiografia)

CARVALHO, GILBERTO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:45:50Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:49Z (GMT). No. of bitstreams: 1 07313.pdf: 4614224 bytes, checksum: b35f3b3a0d88e2ee74e856c2c7883aaf (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
293

Otimizacao do sistema de radioprotecao nas instalacoes radiograficas de gamagrafia

ANTONIO FILHO, JOAO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:44Z (GMT). No. of bitstreams: 1 06775.pdf: 15025996 bytes, checksum: fbd53da186ea56301e555ed353c39360 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
294

Cobalt-60 radiation beam verification in nasopharyngeal carcinoma: a Kenya experience

Kikwai, Richard Malakwen January 2012 (has links)
Thesis (MTech (Radiography))--Cape Peninsula University of Technology, 2012 / Background and purpose The primary aim of this study was to analyse the accuracy and reproducibility of radiation treatment to patients with nasopharyngeal carcinoma at the only tertiary teaching and referral hospital in Kenya. The secondary objective was to review literature on quality assurance procedures that would result to provision of quality radiation treatment to this group of patients. Materials and method During the period May 2011 to March 2012, 35 patients with head and neck cancer comprising of 27 patients with nasopharyngeal carcinoma, 7 with paranasal sinus carcinoma and 1 with lymphoma falling within the enrolment criteria were treated using Equinox cobalt-60 unit with the same beam arrangement and were studied prospectively. Radical radiotherapy was delivered using conventional 2D technique in a routine dose of 60-66Gy to the primary and 50Gy to lymph nodes with additional dose to residual neck nodes. During the period of their treatment, a lateral portal image was taken once weekly. Four film image pairs were obtained per patient with each patient positioned and immobilised in an individualised Orfit thermoplastic mask and a head and neck support. The 4 portal images were compared to a corresponding simulator film taken during simulation planning. Deviations from the varied bony landmarks were measured on the portal images and simulator image from the centre of the radiation beam.
295

Three-dimensional thinking in radiography

Venter, Dalene January 2008 (has links)
Dissertation submitted in fulfilment of the requirements for the degree Master of Technology: Radiography in the Faculty of Health and Wellness Sciences, 2008 / Introduction Research to date has not been able to agree whether spatial abilities can be developed by practice. According to some researchers spatial ability is an inherited cognitive ability, compared to spatial skills that are task specific and can be acquired through formal training. It is commonly assumed that radiographers require general cognitive spatial abilities to interpret complex radiographic images. This research was conducted to investigate second year radiography students’ three-dimensional thinking skills pertaining to film-viewing assessments. Materials and methods The experimental research strategy was mainly applied together with correlation research. Two trials were run (in 2005 and 2006). The sample group consisted of fifteen second year diagnostic radiography students in 2005 and twenty-three second year diagnostic radiography students, of the same institution, in 2006. Each year group was randomly divided into a control group and an intervention group. Two instruments were used, that is a film-viewing assessment and a three-dimensional test, Academic Aptitude Test (University) (AAT) nr. nine: Spatial Perception (3-D). The whole class completed this basic spatial aptitude test, as well as a base-line film viewing assessment, which focused on the evaluation of technique/anatomy of second year specialised radiographic projections. The marks that the students achieved in the fore-mentioned tests were compared, to determine if there was any correlation between their performances in the different tests. A curricular intervention, which was intended to improve applied three-dimensional skills, was subsequently applied. The students executed certain modified radiographic projections on parts of a human skeleton. For each radiographic projection, the students had to draw the relation of the X-ray beam to the specific anatomical structures, as well as the relation of these structures to the film. The related images of these projections were also drawn. With each of the following sessions, films including images of the previous session were discussed with each student. After the intervention, the whole class wrote a second film-viewing assessment. The marks achieved in this assessment were compared to the marks of the initial film-viewing assessment to determine the influence of the intervention on the performance of the intervention group. Following this assessment, for ethical reasons, the same intervention took place with the control group. A third film-viewing assessment was then written by all the diagnostic second year students to evaluate the overall impact of the intervention on the applied three-dimensional skills of the class. The marks of both the 2005 and 2006 classes (intervention classes) were compared to the marks achieved by former classes from 2000 to 2004 (control classes), in film-viewing assessments to evaluate the role of the curricular intervention over the years. The students again completed the three-dimensional test, Spatial Perception (3-D) to evaluate the impact of the intervention on students’ general three-dimensional cognitive abilities. These marks were also compared to the marks of the third filmviewing assessment, to determine if there was any correlation between the students’ performances in the different tests. Results The intervention groups did not perform significantly better in film-viewing assessments after the intervention, compared to the control groups, but reasonable differences, favouring the intervention group, were achieved. Statistical significance was achieved in film-viewing assessments with both year groups after the whole class had the intervention. The intervention year groups also performed significantly better than the previous year groups (without the intervention) in film-viewing assessments. The performance in general three-dimensional cognitive abilities of the group of 2006 improved significantly after the intervention, but on the contrary, the performance of the group of 2005 declined. There was a small intervention effect on the performance of the group of 2006. Only a weak to moderate correlation between the marks of the students achieved in the three-dimensional tests and the marks achieved in the film-viewing assessments, was found. Conclusion The contrasting evidence between the data of the two groups (2005 and 2006) in the three-dimensional tests and the small intervention effect on the performance of the group of 2006, makes the intervention not applicable for the increase of general spatial abilities. The results of this research show that the applied three-dimensional skills of radiography students in interpreting specialised and modified projections can be improved by intensive practice, independent of their inherited spatial abilities.
296

An integrated learning curriculum for radiography in South Africa

Engel-Hills, Penelope Claire January 2005 (has links)
Thesis (DTech (Radiography))--Cape Peninsula University of Technology, 2005. / The most significant changes and challenges to radiography in South Africa are rapid technological changes in the fields of imaging and radiation oncology, the changing status of radiographers as members of the multi-disciplinary health care team and the socioeconomic impact of post-apartheid ideology, policy and legislation with regard to both higher education and health provision. This altered landscape in which academic and clinical work is accomplished has impacted on radiography education. Curricula must change in order to equip graduates to work effectively in the modern workplace and the Integrated Learning Curriculum (ILC) is one such curriculum response. The traditional radiography curriculum of connecting subject-based theory education with interspersed clinical experience where there is reliance on students connecting or applying the subject content taught in the classroom to clinical practice was challenged. The ILC planned to enhance the integration of teaching, learning and assessment in the academy and workplace in a transforming South Africa. This study took advantage of the opportunity to capture data and learning from this curriculum renewal. The research was guided by the questions: I) What is the nature of radiographic knowledge? 2) What curricular options would facilitate radiographic knowledge? 3) What would enable or constrain successful curriculum implementation? 4) Is the ILC an appropriate curriculum for Radiography? This study facilitated a 'layered' understanding of integration and integrated curriculum through exploration of the concept 'integration'. This was achieved through; a national survey that investigated opinion on the status of radiography education in South Africa in 2003; interpretation of the context within which the ILC was located; a search of relevant literature; and a case study that gathered data over a three-year period. Findings support the notion that the workplace is a key influence on higher education curricula and that an integrated learning curriculum suits radiography.
297

O efeito da ciclosporina-A na osseointegração /

Sakakura, Celso Eduardo. January 2005 (has links)
Resumo: Agentes imunossupressores provocam alterações severas no metabolismo ósseo mineral podendo resultar em osteopenia. Tais alterações podem ser prejudiciais no processo e manutenção da osseointegração. Este estudo teve o objetivo de avaliar a influência da administração de ciclosporina-A (CSA) na osseointegração de implantes de titânio, através da avaliação: durante a cicatrização óssea ao redor de implantes dentais (Estudo I); da densidade óssea ao redor implantes dentais (Estudo II); da retenção do implante após a cicatrização óssea de implantes dentais (Estudo III) e radiográfica da qualidade óssea ao redor de implantes dentais já osseointegrados (Estudo IV). Os resultados permitiram concluir que a administração de CSA durante a cicatrização óssea resulta em diminuição da osseointegração e da densidade óssea ao redor do implante dental. Ainda, a administração de CSA após o período de cicatrização óssea ao redor do implante reduz a sua retenção mecânica ao tecido ósseo e promove a diminuição da qualidade e da densidade óssea radiográfica ao redor do implante dental. / Abstract: Immunosupressive agents may induce severe changes on bone mineral metabolism resulting in osteopenia. These alterations may impair the osseointegration processes. The purposes of this study were evaluate the cyclosporin-A (CSA) influence: on bone healing around dental implants (Study I); on bone density around dental implants (Study II); on mechanical retention of dental implants integrated to the bone (Study III) and on radiographic bone density and quality around dental implants integrated to the bone (Study IV). The CSA administration may impair the osseointegration and bone density during the bone healing. Besides, the administration of CSA after bone healing may impair the dental implant mechanical retention and decrease the radiographic bone density and bone quality around dental implants integrated to the bone. / Orientador: Gulnara Scaf / Coorientador: Elcio Marcantonio Junior / Banca: Guilherme Monteiro Tosoni / Banca: Maria Lúcia Rubo de Rezende / Banca: Jamil Awad Shibli / Banca: Francisco Haiter Neto / Doutor
298

Relação entre imagem radiográfica e presença de lesão de cárie com cavidade em superfícies próximas de dentes posteriores : revisão sistemática da literatura / Relationship between radiographic image and presence of cavitation in proximal caries lesions of posterior teeth : systematic review of the literature

Denadai, Guilherme Andrade January 2016 (has links)
O exame radiográfico interproximal vem sendo o método mais comumente utilizado como auxiliar no diagnóstico da presença e extensão de lesões de cárie nas superfícies proximais de dentes posteriores e, muitas vezes, funciona como base para a tomada de decisão restauradora. Este estudo tem o objetivo de analisar a possibilidade de previsão de cavitação clínica ou ausência desta nas superfícies proximais em contato de dentes posteriores permanentes e decíduos, de acordo com a extensão da imagem em radiografias interproximais. Para tanto, uma revisão sistemática da literatura foi realizada. Após a formulação da questão de pesquisa estruturada, dois revisores realizaram uma busca nas bases eletrônicas das bibliotecas Medline (PubMed), Embase, LILACS, Scopus e Cochrane. Apenas estudos clínicos foram incluídos. Não houve restrição de idioma ou de data de publicação, sendo incluídos estudos publicados até o mês de abril de 2016. Também foi realizada busca manual nas referências dos artigos selecionados e nas edições da revista Caries Research. Ao final, foram selecionados 11 estudos, os quais apresentaram avaliação da imagem radiográfica e relação com a condição clínica através de diferentes métodos: exame visual associado ou não à separação dentária, seguida ou não de moldagem, ou avaliação após abertura de cavidade em procedimento restaurador com ou sem fotografias. Os resultados da análise qualitativa dos dados mostram que, quando a lesão de cárie apresenta extensão de imagem radiográfica em metade externa de esmalte, a maior probabilidade é de que não haja presença de cavitação clínica; quando a imagem estende-se além da metade ou 2/3 interno de dentina, provavelmente existe cavitação. A discordância mais evidente entre os estudos ocorre quando a imagem radiolúcida atinge a metade interna de esmalte ou metade/terço externo da dentina. Quando na presença deste tipo de imagem radiográfica, o afastamento dentário e inspeção visual estão indicados para a tomada de decisão diagnóstica e consequente decisão de intervenção. Além disso, os fatores que podem influenciar na probabilidade da presença de cavitação clínica devem ser considerados, como padronização da técnica radiográfica, atividade e taxa de progressão de cárie, diferenças populacionais e idade do paciente. / Bitewing radiographic examination has been the most commonly used method to assist the diagnosis of the presence and extension of caries lesions on the proximal surfaces of posterior teeth, and often serves as a basis for restorative decision making. This study aims to analyze the possibility of prediction of clinical cavitation or absence of it in the proximal surfaces of permanent and deciduous posterior teeth, according to the extension of the image in bitewing radiographs. A systematic review of the literature was performed. After formulating the structured research question, two reviewers searched the electronic databases of the Medline (PubMed), Embase, LILACS, Scopus and Cochrane libraries. Handsearch was also carried out on the references of the selected articles and in the editions of the journal Caries Research. Only clinical studies were included. There was no restriction on language or date of publication, included studies published until the month of april of 2016. Eleven studies were selected, which presented an evaluation of the radiographic image and relation with the clinical condition through different methods: visual examination associated or not with dental separation (followed or not by impression) or evaluation during drilling with or without photographs. A qualitative analysis of the data show that when the caries lesion presents radiographic image in the outer half of the enamel, the greatest probability is that there is no clinical cavitation; when the image extends beyond to the inner half or inner 2/3 of dentine, there is a great chance of cavitation. The most evident discordance among studies occurs when the radiolucent image reaches the cut-off point of the inner half of the enamel or external half / third of the dentin. When in the presence of this type of radiographic image, the dental separation and visual inspection are indicated for the diagnostic decision making and consequent intervention decision. In addition, factors that may influence the probability of the presence of clinical cavitation should also be considered, such as standardization of the radiographic technique, activity and rate of caries progression, population differences and age of the patient.
299

Radiografia com neutrons em tempo - real

MENEZES, MARIO O. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:41Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:40Z (GMT). No. of bitstreams: 1 06914.pdf: 2955248 bytes, checksum: 106449a86e70d89b0638f2132a9326c4 (MD5) / Tese [Doutoramento] / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
300

Emprego dos policarbonatos makrofol-de e CR-30 em radiografia com neutrons

PEREIRA, MARCO A.S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:33Z (GMT). No. of bitstreams: 1 11313.pdf: 4364467 bytes, checksum: 80dca67e716c2de36cf87cbbab397c48 (MD5) / Dissertacao (Mestrado) / IPEN/D / Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP

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