Refractive integrated nonimaging solar collectors design and analysis of a novel solar-daylighting-technology

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.A novel and original category of low-cost static solar-daylighting-collectors named Keywo solar energy, solar collectors, daylighting systems, nonimaging optics, Refractive Integrated Nonimaging Solar Collectors (RINSC) has been designed and thoroughly tested. The RINSC category is based on nonimaging optics and integrates several optical elements, such as prismatic arrays and light guides, into a single-structured embodiment made of solid-dielectric material. The RINSC category is sub-divided in this thesis into four distinctive and original sub-categories/systems: Prismatic Solar Collectors (PSC), Multi-Prismatic Solar Collectors (MPSC), Integrated Multi-Prismatic Solar Collectors (IMPSC) and Vertically Integrated Nonimaging Solar Collectors (VINSC). The optical configuration and compact embodiment of these systems allows them to be integrated into a building façade without creating any protrusion, indicating that they can lead to solar collector systems with high building integration potential. Laboratory and outdoor experimental tests conducted with a series of demonstration prototypes made of clear polymethyl-methacrylate (PMMA) and manufactured by laser ablation process, yield peak transmission efficiencies TE varying from 2% to 8%. Computer simulations indicated that transmission efficiencies TE > 30% are possible. The design and development of the innovative optical systems introduced in this thesis were backed-up with extensive computer ray-tracing analysis, rapid-prototyping, laboratory and outdoor experimental tests. Injection moulding computer simulations and surface analysis concerning the development of the RINSC systems were also conducted. Basic theory and comprehensive literature review are presented. This research has also resulted in the design and prototyping of a novel optical instrumentation named Angular Distribution Imaging Device (ADID), specially developed to analyse the spatial distribution of light emerging from the exit aperture of solar collectors/concentrators. The systems and knowledge described in this thesis may find application in areas such as solar collector systems to harvest sunlight for natural illumination in buildings, solar-photovoltaic and solar-thermal.Funded in part by the Brazilian National Council for Scientific and Technological Development (CNPq), under the scholarship grant 200663/2004-6 (GDE)

Osteocitos y la regulación de la formación ósea

For many years, osteocytes have been the forgotten bone cells and considered as inactive spectators buried in the bone matrix. We now know that osteocytes detect and respond to mechanical and hormonal stimuli to coordinate bone resorption and bone formation. Osteocytes are currently considered a major source of molecules that regulate the activity of osteoclasts and osteoblasts, such as RANKL and sclerostin; and genetic and pharmacological manipulations of either molecule markedly affect bone homeostasis. This article summarizes recent findings demonstrating the mechanisms by which osteocytes regulate the number and activity of osteoblasts and thus affect bone formation

Body image dissatisfaction among rural and urban adolescents

To identify the prevalence of body image dissatisfaction among adolescents living in rural and urban areas, and to analyze the influence of demographic and anthropometric variables on body image dissatisfaction. A total of 629 adolescents aged 13 to 17 years from urban and rural areas participated in the study. Demographic variables (gender, age, area of residence), anthropometric measurements (body weight, height, skinfold thickness) and body image data were collected. BMI (underweight: <18,5 kg/m²; normal weight: between 18,5 and 25,0 kg/m²; overweight: > 25 kg/m²) and the sum of two skinfold thicknesses, Σ2SF (girls: low: <16 mm, ideal: between 16 and 36 mm, high: >36 mm; boys: low: <12 mm, ideal: between 12 and 25 mm, high: >25 mm) were then calculated. The prevalence of body image dissatisfaction was similar (p≥0,05) among rural (64,2%) and urban adolescents (62,8%). Boys wished to increase the size of their body silhouette (41,3%), whereas girls wished to reduce it (50,5%) (p<0,001). Adolescents with low and excess weight based on BMI and with high Σ2SF presented a 3,14, 8,45 and 2,08 times higher chance of body image dissatisfaction, respectively. A high prevalence of body image dissatisfaction was observed among adolescents from rural and urban areas. An unhealthy nutritional status and body adiposity increase the chances of body image dissatisfaction. These findings emphasize the social pressure on girls to remain slim and on boys to attain an athletic body

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

AbstractThe Ni81Fe19/V/Ni81Fe19 heterostructures has been produced by magnetron sputtering and analyzed by ferromagnetic resonance. Two systems were investigated: the non symmetrical NiFe(50Å)/V(t)/NiFe(30Å) trilayers and the symmetrical NiFe(80Å)/V(t)/NiFe(80Å) trilayers, with variable ultrathin V thickness t. Ferromagnetic exchange coupling was evidenced for t below 10Å by the excitation of the optic mode, in the case of the non symmetrical samples, and by the observation of a single resonance mode for the symmetrical trilayers. For larger V thickness, all samples exhibited two modes, which were attributed to the resonance of the individual NiFe layers with different effective magnetizations. The analysis with the equilibrium and resonance conditions provided the exchange coupling constants and effective magnetizations

Estimating the effective degrees of freedom in univariate multiple regression analysis

The general linear model provides the most widely applied statistical framework for analyzing functional MRI (fMRI) data. With the increasing temporal resolution of recent scanning protocols, and more elaborate data preprocessing schemes, data independency is no longer a valid assumption. In this paper, we revise the statistical background of the general linear model in the presence of temporal autocorrelations. First, when detecting the activation signal, we explicitly account for the temporal autocorrelation structure, which yields a generalized F-test and the associated corrected (or effective) degrees of freedom (DOF). The proposed approach is data driven and thus independent of any specific preprocessing method. Then, for event-related protocols, we propose a new model for the temporal autocorrelations (“damped oscillator” model) and compare this model to another, previously used in the field (first-order autoregressive model, or AR(1) model). In the case of long fMRI time series, an efficient approximation for the number of effective DOF is provided for both models. Finally, the validity of our approach is assessed using simulated and real fMRI data and is compared with more conventional methods

Stages of behavioral change and positive perception of the environment towards physical activity among urban park users

The objectives of this study were to identify the stages of behavioral change (SBC) towards physical activity (PA) among users of urban parks, to determine the association between socio-demographic and economic variables of users of urban parks in relation to physical activity (PA), and to analyze environmental indicators of the park perceived positively for PA. A total of 218 users of an urban park, who filled out a questionnaire regarding socio-demographic data, SBC and perception of the existing environment, participated in the study. The most prevalent SBC were maintenance (56.6%) and action (21.1%). Most park users (78.7%) presented an active behavior (maintenance + action) towards PA, with this behavior being prevalent among middle-aged individuals (p<0.05). The beauty and geographic location of the park, technological and architectonic factors, some normative policies (public services to the users’ disposition), and values and attitudes were perceived positively for PA, regardless of whether the users regularly performed PA or not. The study suggests that most public park users present an active behavior towards PA, especially middle-aged individuals. In addition, the perception of environmental indicators is positive among physically inactive and active park users, irrespective of SBC

Micropropagation of Ocotea porosa (Nees & Martius) Barroso

The objective of this work was the establishment of a micropropagation protocol for Ocotea porosa by multiplication of shoots from axillary buds. Different concentration of BAP (0; 2.5; 5 or 10 ìM) or BAP+KIN (0; 1.25; 2.5 or 5 ìM) were investigated to optimize the multiplication. Shoot growth was stimulated with reduced concentration of BAP (0; 0.5; 1 or 1.5 ìM) or KIN (0.5 or 1ìM) or activated charcoal (0.5; 1; 2 or 3 gl-1). For root induction different concentrations of IBA (0; 1.25; 2.5; 5 or 10 ìM) or (0; 2.5; 5 or 10 mM) were applied. The highest mean multiplication rate was observed in the fourth subculture with 5 ìM BAP, reaching 5.3 shoots per explant. The shoots elongated in culture medium supplemented with 2 gl-1 activated charcoal and presented bigger leaves than on medium with reduced concentration of BAP. The shoots rooted on medium contains 10 ìM IBA or after pulse treatment of 10 mM (68.7 and 62.6% of rooting, respectively). The survival rate of the plants was 56.7%. This study showed that O. porosa micropropagation is feasible; however it needs further research in order to increase plant survival.Key words: 6-Benzylaminopurine, multiplication, rooting, in vitro culture, apical shoots, native specie

Os dispositivos de poder no espa?o escolar e suas influ?ncias no processo de ensino e aprendizagem

This assigment is the concludion of social sciences literature of Universidade Federal Fronteira Sul, the themes are: The power system between techer?s and student?s at school environment which aims to analise and compreend the strategies of educacional methods oh the learning process. The assigment is divided into 5 chapters and enphases the Education and Antropology.The research is based on qualitative, methology from observations an description of semi structure classes, interviews and focus on private high school student?s on the city of Chapec?. The presente assigment is to research and deepen the themes about education, specially the importance of the social sciences literature course getting involved in the school environment and colaborates with research developments to improve the future teacher?s. Finally considering the research colaborates to understand the mechanisms of power, directly related to Teachers and student It Influences on teaching and learning strategies, methodologist and assessment used by Teachers suporting the performances.Esse Trabalho de Conclus?o do Curso de Licenciatura em Ci?ncias Sociais da Universidade Federal da Fronteira Sul, aborda o tema: Os dispositivos de poder entre professores e alunos no espa?o escolar, o qual teve como objetivo principal analisar e compreender as estrat?gias e os m?todos educacionais no contexto do processo de ensino e aprendizagem. O trabalho divide-se em cinco cap?tulos e compreende um estudo de caso com ?nfase nas ?reas da Educa??o e da Antropologia. A pesquisa ? baseada na metodologia qualitativa proveniente de observa??es e descri??es de aulas, entrevistas semiestruturadas com gestores e docentes, e grupo focal com os estudantes do Ensino M?dio de uma escola da rede privada de ensino da cidade de Chapec?-SC. O presente trabalho corrobora para aprofundar as tem?ticas sobre a Educa??o, principalmente pela import?ncia do curso em Licenciatura em Ci?ncias Sociais inserir-se no espa?o escolar colaborando e desenvolvendo pesquisas para fomentar a doc?ncia de futuros professores. Essa pesquisa contribuiu para conhecer o espa?o escolar da rede privada de educa??o e principalmente para compreender as rela??es de poderes vis?veis e invis?veis constru?dos nesse espa?o. Por fim, considera-se que a pesquisa colaborou em entender que os dispositivos de poder (es) est?o diretamente relacionados a rela??o professor/a e aluno/a e possui influ?ncia no ensino e aprendizagem atrav?s de estrat?gias, metodologias e instrumentos de avalia??o utilizados por docentes e embasando o desempenho do/a aluno/a. ? atrav?s dos dispositivos de poder (es) dos/das docentes que ocorre o ensino e aprendizagem do/da estudante