889 resultados para Evaluation model
Resumo:
Previous research has highlighted the importance of positive physical activity (PA) behaviors during childhood to promote sustained active lifestyles throughout the lifespan (Telama et al. 2005; 2014). It is in this context that the role of schools and teachers in facilitating PA education is promoted. Research suggests that teachers play an important role in the attitudes of children towards PA (Figley 1985) and schools may be an efficient vehicle for PA provision and promotion (McGinnis, Kanner and DeGraw, 1991; Wechsler, Deveraux, Davis and Collins, 2000). Yet despite consensus that schools represent an ideal setting from which to ‘reach’ young people (Department of Health and Human Services, UK, 2012) there remains conceptual (e.g. multi-component intervention) and methodological (e.g. duration, intensity, family involvement) ambiguity regarding the mechanisms of change claimed by PA intervention programmes. This may, in part, contribute to research findings that suggest that PA interventions have had limited impact on children’s overall activity levels and thereby limited impact in reducing children’s metabolic health (Metcalf, Henley & Wilkin, 2012). A marked criticism of the health promotion field has been the focus on behavioural change while failing to acknowledge the impact of context in influencing health outcomes (Golden & Earp, 2011). For years, the trans-theoretical model of behaviour change has been ‘the dominant model for health behaviour change’ (Armitage, 2009); this model focusses primarily on the individual and the psychology of the change process. Arguably, this model is limited by the individual’s decision-making ability and degree of self-efficacy in order to achieve sustained behavioural change and does not take account of external factors that may hinder their ability to realise change. Similar to the trans-theoretical model, socio-ecological models identify the individual at the focal point of change but also emphasises the importance of connecting multiple impacting variables, in particular, the connections between the social environment, the physical environment and public policy in facilitating behavioural change (REF). In this research, a social-ecological framework was used to connect the ways a PA intervention programme had an impact (or not) on participants, and to make explicit the foundational features of the programme that facilitated positive change. In this study, we examined the evaluation of a multi-agency approach to a PA intervention programme which aimed to increase physical activity, and awareness of the importance of physical activity to key stage 2 (age 7-12) pupils in three UK primary schools. The agencies involved were the local health authority, a community based charitable organisation, a local health administrative agency, and the city school district. In examining the impact of the intervention, we adopted a process evaluation model in order to better understand the mechanisms and context that facilitated change. Therefore, the aim of this evaluation was to describe the provision, process and impact of the intervention by 1) assessing changes in physical activity levels 2) assessing changes in the student’s attitudes towards physical activity, 3) examining student’s perceptions of the child size fitness equipment in school and their likelihood of using the equipment outside of school and 4) exploring staff perceptions, specifically the challenges and benefits, of facilitating equipment based exercise sessions in the school environment. Methodology, Methods, Research Instruments or Sources Used Evaluation of the intervention was designed as a matched-control study and was undertaken over a seven-month period. The school-based intervention involved 3 intervention schools (n =436; 224 boys) and one control school (n=123; 70 boys) in a low socioeconomic and multicultural urban setting. The PA intervention was separated into two phases: a motivation DVD and 10 days of circuit based exercise sessions (Phase 1) followed by a maintenance phase (Phase 2) that incorporated a PA reward program and the use of specialist kid’s gym equipment located at each school for a period of 4 wk. Outcome measures were measured at baseline (January) and endpoint (July; end of academic school year) using reliable and valid self-report measures. The children’s attitudes towards PA were assessed using the Children’s Attitudes towards Physical Activity (CATPA) questionnaire. The Physical Activity Questionnaire for Children (PAQ-C), a 7-day recall questionnaire, was used to assess PA levels over a school week. A standardised test battery (Fitnessgram®) was used to assess cardiovascular fitness, body composition, muscular strength and endurance, and flexibility. After the 4 wk period, similar kid’s equipment was available for general access at local community facilities. The control school did not receive any of the interventions. All physical fitness tests and PA questionnaires were administered and collected prior to the start of the intervention (January) and following the intervention period (July) by an independent evaluation team. Evaluation testing took place at the individual schools over 2-3 consecutive days (depending on the number of children to be tested at the school). Staff (n=19) and student perceptions (n = 436) of the child sized fitness equipment were assessed via questionnaires post-intervention. Students completed a questionnaire to assess enjoyment, usage, ease of use and equipment assess and usage in the community. A questionnaire assessed staff perceptions on the delivery of the exercise sessions, classroom engagement and student perceptions. Conclusions, Expected Outcomes or Findings Findings showed that both the intervention (16.4%) and control groups increased their PAQ-C score by post-intervention (p < 0.05); with the intervention (17.8%) and control (21.3%) boys showing the greatest increase in physical activity levels. At post-intervention, there was a 5.5% decline in the intervention girls’ attitudes toward PA in the aesthetic subdomains (p = 0.009); whereas the control boys had an increase in positive attitudes in the health domain (p = 0.003). No significant differences in attitudes towards physical activity were observed in any other domain for either group at post-intervention (p > 0.05). The results of the equipment questionnaire, 96% of the children stated they enjoyed using the equipment and would like to use the equipment again in the future; however at post-intervention only 27% reported using the equipment outside of school in the last 7 days. Students identified the ski walker (34%) and cycle (32%) as their favorite pieces of equipment; with the single joint exercises such as leg extension and bicep/tricep machine (<3%) as their least favorite. Key themes from staff were that the equipment sessions were enjoyable, a novel activity, children felt very grown-up, and the activity was linked to a real fitness experience. They also expressed the need for more support to deliver the sessions and more time required for each session. Findings from this study suggest that a more integrated approach within the various agencies is required, particularly more support to increase teachers pedagogical content knowledge in physical activity instruction which is age appropriate. Future recommendations for successful implementation include sufficient time period for all students to access and engage with the equipment; increased access and marketing of facilities to parents within the local community, and professional teacher support strategies to facilitate the exercise sessions.
Resumo:
Le présent mémoire expose les résultats d’une étude de la performance des chantiers ouverts dans un contexte de mines profondes ayant été effectuée dans le cadre du projet de recherche « Mines profondes : défis d’exploitation et impacts sur la récupération minéralurgique » réalisé par le département de génie des mines, de la métallurgie et des matériaux de l’Université Laval. Les données utilisées dans le cadre de cette étude sont en lien avec la planification et l’exploitation de plus de mille chantiers minés entre 860 et 2 450 m de profondeur à la mine souterraine LaRonde de Mines Agnico Eagle, la plus profonde actuellement de l’hémisphère ouest. On y présente une revue de la littérature qui fait la description des problématiques de dilution et de pertes opérationnelles de la réserve minérale liées à la performance des chantiers ouverts ainsi que de leurs conséquences sur les projets miniers. Une comparaison des performances planifiées et réalisées au site de LaRonde y est présentée, ainsi que les résultats d’analyses statistiques ayant permis de montrer que la variation du ratio des contraintes in situ avec la profondeur est un facteur d’influence significatif de la performance des chantiers. L’effet de ce facteur d’influence y est aussi illustré et validé à l’aide d’une série de modèles numériques. Le mémoire présente également une première approche visant à développer un modèle d’évaluation de la dilution dans les chantiers ouverts qui prend en compte la profondeur de minage. Finalement, afin d’améliorer la précision de l’estimation de la réserve minérale lors de l’évaluation de projets miniers, une méthodologie d’estimation intégrant le modèle d’évaluation proposé est présentée pour les projets dont les contextes géologique, géotechnique et opérationnel sont comparables à ceux du site de LaRonde.
Resumo:
O mundo mudou muito e o modelo escolar existente, que vem desde o século XVIII, manifesta dificuldades de adaptação ao novo mundo. As dificuldades de ensino e aprendizagem também são muito mais vastas do que as do passado, num ensino obrigatório e massificado, e a capacidade de captação da atenção que a escola antes produzia, é hoje mais difícil de obter. A motivação, sem a qual não há aprendizagem, revela a dificuldade da educação escolar em lidar com a realidade atual. Dentro de um referencial teórico sustentado, importa analisar e interpretar o modo como decorre a aprendizagem e o modelo de avaliação do terceiro ciclo do ensino básico, bem como investigar os fatores que influenciam a motivação dos alunos. Para atingir os objetivos do estudo optou-se por uma abordagem metodológica qualitativa, recorrendo à realização de entrevistas semiestruturadas aos vários intervenientes educativos e à análise de documentos, numa escola selecionada para o efeito. Constatou-se, através dos dados obtidos, que a reprovação tem um impacto extremamente significativo no desempenho escolar dos alunos, e que se umas vezes provoca um efeito pedagógico, noutras tem o efeito exatamente inverso. Este trabalho consiste num estudo de caso sobre o efeito que a reprovação provoca na motivação dos alunos que ficam retidos e tem como intuito encontrar estratégias para aumentar a motivação desses mesmos alunos.
Resumo:
El modelo de evaluación bidimensional MEB en la educación superior, propuesto en este trabajo mide el conocimiento de estudiantes versus grado de certeza. El análisis de estas dos dimensiones permite al profesor determinar áreas de conocimiento a profundizar con sus estudiantes. La investigación fue descriptiva y correlacional, fueron aplicados métodos científico e inductivo. Las técnicas utilizadas fueron cuestionarios y análisis estadístico y recursos técnicos fueron: sistema de gestión de aprendizaje Moodle, software para análisis matemático MATLAB, EXCEL, laboratorios de la Facultad de Informática y Electrónica (FIE) de la Escuela Superior Politécnica de Chimborazo (ESPOCH), institución donde se llevó a cabo el estudio. El MEB propone la aplicación de cuestionarios de selección múltiple con el mecanismo CBM (Certainty based marking - Marcado basado en la certeza), sobre un aula virtual creada en el sistema Moodle. CBM permite medir por cada pregunta de un cuestionario las dimensiones conocimiento y certeza.
Resumo:
A avaliação de desempenho docente tem sido considerada o alfa e o ômega dos sistemas educativos, nas últimas décadas. Em Portugal, desde 2007, esta questão tornou-se mais acutilante devido às alterações introduzidas no Estatuto da Carreira Docente que originaram uma alteração profunda nas práticas de avaliação do desempenho docente. A implementação do novo modelo despoletou forte resistência por parte destes profissionais, alimentada por uma base concetual distante da realidade das escolas portuguesas e por tibiezas na execução do processo de avaliação. O principal objetivo deste estudo consistiu em apresentar os contributos de professores para um modelo de avaliação do desempenho docente, assumindo as expetativas e as perceções destes profissionais como referente imprescindível para a sustentabilidade avaliativa do modelo. Para além disso, procedeu-se a uma breve descrição e avaliação do modelo de avaliação docente, implementado entre 2007 e 2011, recuperando perceções depuradas pelo tempo. O estudo, descritivo e inferencial, conciliou abordagens de natureza quantitativa e qualitativa, tendo recorrido a um questionário, aplicado a 585 docentes em funções no Algarve, e à entrevista, realizada a quatro informadores privilegiados do processo avaliativo. Os resultados alcançados apontaram para i) de um conjunto de pareceres favoráveis face a alguns aspetos do modelo de avaliação vigente entre 2007 e 2011; ii) uma avaliação globalmente negativa do mesmo modelo, iii) a definição de componentes das diferentes dimensões de modelo avaliativo, onde se identificou a preponderância da vertente formativa; a articulação da avaliação dos docentes com a avaliação de escola e com outros documentos de gestão escolar; a coincidência dos ciclos avaliativos com a progressão na carreira; a autoavaliação como principal instrumento de recolha de dados; a observação facultativa de aulas; a existência de avaliadores com formação em supervisão ou avaliação e capacitados com um perfil adequado; e o uso dos resultados da avaliação para a melhoria das práticas letivas e para a progressão na carreira, sendo ainda de considerar a possibilidade de acionar mecanismos de recuperação, caso existissem indicadores de insucesso na prática profissional do docente. O estudo termina com o enunciado de recomendações para a reconceptualização do modelo de avaliação dos docentes, permitindo reconhecer e eliminar os fatores conflituantes, tendo em vista a concretização da avaliação docente como estratégia impulsionadora da melhoria do desempenho dos professores, da escola e do sistema educativo. Palavras-chave: avaliação educacional; avaliação de desempenho docente; modelos de avaliação de desempenho docente; desenvolvimento profissional do professor, educadores e professores dos ensinos básico e secundário; ABSTRACT:Teacher performance appraisal has been considered the alpha and omega of educational systems in recent decades. In Portugal, since 2007, this issue has become more incisive due to amendments to the Teaching Career Statute that brought deep changes in assessment practices of teacher performance. The application of the new system has triggered strong resistance by these professionals, powered by a distant conceptual basis of the reality of Portuguese schools and weaknesses in the implementation of the appraisal process. The aim of this study is to present the teachers contributions to this teacher performance appraisal model, taking the expectations and perceptions of these professionals as an essential reference for the sustainability of the appraisal process. In addition, a brief description and evaluation of the teacher performance appraisal model, implemented between 2007 and 2011, was given, recovering perceptions filtered by time. The study, descriptive and inferential, reconciled quantitative and qualitative approaches, has used a questionnaire applied to 585 teachers serving on the Algarve, and an interview to four held key informants of the teacher appraisal process. The achieved results showed i) a set of favorable opinions about some aspects of the current evaluation model between 2007 and 2011; ii) a generally negative evaluation of the same model, iii) the definition of components of different dimensions of the appraisal system, which showed preponderance of formative purposes; the joint assessment of teachers with school evaluation and other school management documents; the coincidence of the evaluation cycles with career advancement; self-evaluation as the main data collection instrument; the optional classroom observation; the existence of evaluators under supervision in training or evaluation and empowered with the right profile; and the use of evaluation results to improve teaching practices and to career advancement, still considering the possibility of using recovery mechanisms if there were failure indicators in professional teaching practice. The study ends with the statement of recommendations for the reconceptualization of teacher performance appraisal, which allowed to recognize and eliminate conflicting factors, with a view to implementing the teaching appraisal as a compelling strategy for improving teacher performance, school and educational system. Keywords: educational evaluation; teacher performance appraisal; teacher performance appraisal systems; teacher professional development; early years teachers, primary and secondary school teachers.
Resumo:
Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Programa de Pós-Graduação em Geotecnia, 2015.
Resumo:
O presente trabalho foi desenvolvido no âmbito da dissertação de Mestrado em Supervisão Pedagógica e insere-se na linha de investigação de políticas educativas e supervisão pedagógica. Pretendeu-se encontrar, através da investigação que aqui se apresenta, os contributos dos coordenadores de departamento curricular e delegados de grupo com funções de avaliadores internos no processo de avaliação de desempenho docente. Procurou-se ainda encontrar o perfil dos avaliadores para se poder exercer o cargo, assim como apresentar o enquadramento teórico dos autores e legislação que o sustentam. Este estudo focalizou-se no Decreto Regulamentar Regional n.º 26/2012/M, de 8 de outubro que regulamenta as novas regras da avaliação de desempenho docente e a unidade de estudo deste trabalho é uma escola pública do ensino básico e secundário, no concelho de São Vicente, Norte da Madeira. Para dar cumprimento aos eixos de análise do trabalho utilizou-se a metodologia qualitativa estudo de caso e através de uma análise documental, de inquéritos por entrevista dirigidos aos 12 avaliadores internos - coordenadores de departamento e delegados de grupo - e aos 14 docentes avaliados, considerados a amostra da dimensão interna, encontrou-se um perfil de avaliador interno de desempenho docente na prática, assim como os contributos destes na avaliação de desempenho docente, de acordo com a legislação regional da Madeira. Tendo por base os resultados obtidos, concluímos que o novo modelo de avaliação de desempenho de docente é um modelo formativo, privilegia o trabalho colaborativo, promove a reflexão, a partilha e a troca de experiências, bem como a melhoria das práticas pedagógicas e o desenvolvimento profissional, apesar da conjuntura atual não promover a progressão na carreira devido ao congelamento como medida de austeridade, o que desmotiva os docentes avaliados e faz ainda com que estes profissionais encarem a avaliação interna como um trabalho menos sério, que não premeia o desempenho e o mérito.
Resumo:
The research work is devoted to actual problems of development management of industrial enterprises. The general purpose of this work is the choice and justification of rational enterprise development evaluation model and subsequent application of it for assessment of enterprise development level and also forming of recommendations for enterprise management. Theoretical aspects of development management of enterprises were generalized. The approaches to understanding the essence of development enterprise category and its types were considered. It was investigated the evaluation models of enterprise development, their advantages and disadvantages and the difficulties of their implementation. The requirements for formation of the evaluation system of the enterprise development were summarized. It was determined the features of the formation and application of an Index of Enterprise Development. In the empirical part, data about investigated enterprises was collected from their official websites and also complemented with further data from other statistical websites. The analysis was based on the annual financial statements of companies. To assess the level of enterprise development were chosen model proposed by Feshchur and Samulyak (2010). This model involves the calculation of the Index of Enterprise Development using partial indicators, their reference values and weight. It was conducted an analysis of the development of Ukrainian enterprises that produce sauces. OJSC “LZHK” had the highest value of Index of Enterprise Development, in 2013 and 2015, that consisted 0,78 and 0,76 respectively. In 2014 the highest value for the Index belonged to PJSC “Volynholdinh” and amounted 0,74. OJSC “LZHK” had the highest average value of Index of Enterprise Development by the result of 2013-2015 years, and it consisted 0,70. PJSC “Chumak” had the lowest average value of Index of Enterprise Development obtained the result 0,59. In order to raise the enterprise development level, it was suggested to reduce production costs and staff turnover, increase the involvement of employees.
Resumo:
O presente estudo, descritivo com levantamento de dados, aborda a temática das relações entre os Docentes e a Biblioteca Escolar (BE). A escolha do tema deve-se à actualidade e pertinência do mesmo, já que numa sociedade caracterizada por um crescimento ilimitado de informação aliada à diversidade de meios de difusão e à facilidade de acesso às fontes, possibilitada pelas modernas tecnologias, obriga necessariamente a repensar o papel das Bibliotecas Escolares, que passará por uma estreita colaboração e articulação com os professores. Assim, procurou-se conhecer a relação que se estabelece entre os docentes de uma Escola Secundária com 3° Ciclo e a Biblioteca Escolar (BE) com destaque para as formas de apropriação da sua utilização; averiguar outras possibilidades de integração I articulação da BE no desenvolvimento do currículo e das suas práticas; e saber qual a concordância dos professores sobre indicadores que o Modelo de Auto-Avaliação das Bibliotecas Escolares propõe no âmbito da articulação curricular da BE com as estruturas pedagógicas e os docentes. Com o desenvolvimento do estudo verificou-se que os professores consideram que utilizam a biblioteca de uma forma mais participada, diversificada e frequente do que realmente acontece. Quanto à aplicação do Modelo de Auto-avaliação das Bibliotecas Escolares existe um quadro favorável à sua aplicação nesta Escola. /ABSTRACT: This descriptive study, which was done through the organization and analysis of large amounts of information, talks about the relation between teachers and the school library. This theme was chosen due to its pertinence as well as its actuality, as we live in a society marked by the unlimited growth of information associated with the diversity of the means of broadcasting and the easiness people can access the sources thanks to new technologies. This forces us to reconsider the role of school libraries, starting with a close collaboration and articulation with teachers. Thus, we'll try to know the kind of relationship established between the teachers of a high school and the school library, mainly the ways they use it; we'll examine other possibilities of integrating the school library in the development of the curriculum and its practices and know if the teachers agree with the indicators recommended by the self-evaluation model in what concerns the curricular articulation between the school library, the pedagogic structures and the teachers. This study shows that the teachers consider they use the library in a more diversified, shared and frequent way than they really do. ln what concerns the use of the school libraries self-evaluation model, we carne to the conclusion that it can be applied.
Resumo:
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Programa de Pós-Graduação em Administração, Mestrado Profissional em Administração, 2015.
Resumo:
Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.
Resumo:
The dissertation reports on two studies. The purpose of Study I was to develop and evaluate a measure of cognitive competence (the Critical Problem Solving Skills Scale – Qualitative Extension) using Relational Data Analysis (RDA) with a multi-ethnic, adolescent sample. My study builds on previous work that has been conducted to provide evidence for the reliability and validity of the RDA framework in evaluating youth development programs (Kurtines et al., 2008). Inter-coder percent agreement among the TOC and TCC coders for each of the category levels was moderate to high, with a range of .76 to .94. The Fleiss’ kappa across all category levels was from substantial agreement to almost perfect agreement, with a range of .72 to .91. The correlation between the TOC and the TCC demonstrated medium to high correlation, with a range of r(40)=.68, p Study II reports an investigation of a positive youth development program using an Outcome Mediation Cascade (OMC) evaluation model, an integrated model for evaluating the empirical intersection between intervention and developmental processes. The Changing Lives Program (CLP) is a community supported positive youth development intervention implemented in a practice setting as a selective/indicated program for multi-ethnic, multi-problem at risk youth in urban alternative high schools in the Miami Dade County Public Schools (M-DCPS). The 259 participants for this study were drawn from the CLP’s archival data file. The study used a structural equation modeling approach to construct and evaluate the hypothesized model. Findings indicated that the hypothesized model fit the data (χ2 (7) = 5.651, p = .83; RMSEA = .00; CFI = 1.00; WRMR = .319). My study built on previous research using the OMC evaluation model (Eichas, 2010), and the findings are consistent with the hypothesis that in addition to having effects on targeted positive outcomes, PYD interventions are likely to have progressive cascading effects on untargeted problem outcomes that operate through effects on positive outcomes.
Resumo:
Todos nós, educadores, devemos prestar uma atenção aprofundada às potencialidades e inclinações das crianças que constituem os nossos grupos, para que possamos estimular e desenvolver as suas competências. É nesse sentido que desenvolvemos este Estudo Exploratório, com o qual se pretende analisar a adaptação da avaliação de potencial derivada da Teoria das Inteligência Múltiplas ao contexto da Educação Pré-Escolar, com o objectivo de contribuir para a qualidade da intervenção educativa, articulando conceitos como Inteligência, Competência, Potencial, Currículo, Avaliação Dinâmica. Participam no estudo 42 crianças que frequentam Jardim de Infância e integram dois grupos heterogéneos e as respectivas educadoras. A metodologia é de natureza qualitativa e quantitativa, apoiando-se na aplicação dos seguintes instrumentos: modelo de avaliação de potencial baseado no Spectrum; Inventário de Quociente Emocional, versão para crianças e jovens (Bar-On Emocional Quotient Inventory: Youth Version), adaptado a educadores por Candeias e Monteiro (2010); questionário de Caracterização do ambiente educativo - Sala de Actividades, adaptado por Candeias e lglésias (2010); Teste de Avaliação de Habilidades Cognitivas de Solução de Problemas lnterpessoais (EVHACOSPI). Os resultados obtidos sugerem a importância de uma avaliação do potencial, baseada na Teoria das Inteligências Múltiplas, que utiliza instrumentos adequados a cada um dos domínios do potencial e da competência humana propostos por H. Gardner: verbal, Lógico-Matemática, Musical, Corporal-Cinestésica, Visuo-espacial, lnterpessoal, Intrapessoal e Naturalista. Apontam também para o papel que este tipo de avaliação pode desempenhar na intervenção educativa que se objectiva intencional e fundamentada. ABSTRACT: Ali of us, educators, must pay a special attention to the potentialities and inclinations of children who make up our groups, so enabling the stimulation and development of their competences. ln this sense we developed this Exploratory Study, through which is intended to analyse the adaptation of potential evaluation derived from the Theory of Multiple intelligences in the range of Pre-School Education, aiming at the contribution for the educative intervention: articulating concepts such as Intelligence, Competence Potential, Curriculum, and Dynamic Evaluation. The study involves 42 children attending Infant School, belonging to two heterogeneous groups and respective educators. Methodology is of qualitative and quantitative nature, supported by the following instruments: evaluation model based on Spectrum; Inventory of Emotional Quotient, version for children and youths, adapted to educators by Candeias e Monteiro (2010), Query of Characterization of Educative Environment - Activities Room, adapted by Candeias e lglésias (2010); Test for Evaluation of Cognitive Abilities of Interpersonal Problems Solution. (EVHACOSPI). The results suggest the importance of an assessment, based on the Theory of Multiple Intelligence, which uses instruments fitted to each of the domains of human potential and competence proposed by H. Gardiner: Verbal, Logical-Maths, Musical, Corporal¬ Kinaesthetic, Visuo-Spatial, Interpersonal, Intrapersonal and Naturalist. They also refer to the role that this type of assessment can play in the educational intervention aiming to be intentional and grounded.
Resumo:
The aim of this study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. A semi-empirical model was used for the evaluation of transmission properties of this material. Since ambient dose equivalent, H(⁎)(10), is the radiation quantity adopted by IAEA for dose assessment, the variation of the H(⁎)(10) as a function of barite mortar thickness was calculated using primary experimental spectra. A CdTe detector was used for the measurement of these spectra. The resulting spectra were adopted for estimating the optimized thickness of protective barrier needed for shielding an area in an X-ray imaging facility.
Resumo:
Primary X-ray spectra were measured in the range of 80-150kV in order to validate a computer program based on a semiempirical model. The ratio between the characteristic and total air Kerma was considered to compare computed results and experimental data. Results show that the experimental spectra have higher first HVL and mean energy than the calculated ones. The ratios between the characteristic and total air Kerma for calculated spectra are in good agreement with experimental results for all filtrations used.