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‣ Professores de física em contexto de inovação curricular: saberes docentes e superação de obstáculos didáticos no ensino de física moderna e contemporânea; Teachers of physics in the context of curricular innovation: teachers knowledge and overcoming of didactic obstacles in the teaching of Modern and Contemporary Physics.

Siqueira, Maxwell Roger da Purificação
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/06/2012 Português
Relevância na Pesquisa
37.30623%
Nos últimos anos, vem se tornando evidente a necessidade de reforma curricular, principalmente devido às pressões que a escola tem sofrido. Pressões essas que decorrem, entre os diversos motivos, da insatisfação com o ensino, especialmente relacionado à Ciência, que pouco tem contribuído para a formação do indivíduo, condizente com sua época. Surge, assim, a necessidade de mudança do currículo, principalmente o de Ciências. No entanto, nesse processo, depara-se com algumas dificuldades, principalmente relacionadas à formação de professores, pois, muitas vezes, as crenças e concepções desses profissionais não são consideradas importantes por aqueles que desenvolvem uma inovação, o que pode levar ao fracasso da nova proposta. Nesse sentido, este estudo investigou a temática da inovação curricular na perspectiva da inserção da Física Moderna e Contemporânea na Educação Básica, a partir da prática de seis professores de física da rede pública do Estado de São Paulo que, desde 2007, participam de um grupo de pesquisa, desenvolvendo, implementando, avaliando e reestruturando propostas de sequências didáticas com esses tópicos. O objetivo principal foi levantar os obstáculos que estes professores tiveram durante as implementações em sala de aula e...

‣ Detecção e classificação de obstáculos aplicados ao planejamento de trajetórias para veículos de passeio em ambiente urbano; Detection and Classification of Obstacles apply to Path Planning for Passenger Vehicles in Urban Environment

Megda, Poliane Torres
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/10/2011 Português
Relevância na Pesquisa
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Todos os dias a quantidade de veículos nas estradas em todo o mundo está aumentando. Este crescimento combinado com a negligência dos motoristas e alguns fatores externos, tais como estradas mal conservadas e condições climáticas adversas resultaram em um enorme aumento na quantidade de acidentes e, conseqüentemente, de mortes. Atualmente muitos grupos de pesquisa e empresas automotivas estão desenvolvendo e adaptando tecnologias que podem ser incorporadas nos veículos para reduzir esses números. Um exemplo interessante dessas tecnologias é a detecção e classificação de obstáculos móveis (veículos, pessoas, etc.) em ambientes urbanos. Este trabalho apresenta o desenvolvimento de algoritmos para identificação, rastreamento e previsão de obstáculos móveis, determinação de direções proibidas para tráfego do veículo e cálculo de trajetórias livres de colisões. Para isso, foram utilizados dados do sistema de medidas de distância, SICK LMS 291-S05, para monitorar o ambiente a frente do veículo de teste (um automóvel de passeio modificado). Com base nesses dados foi realizado um tratamento computacional através da técnica de Trackers para classificar todos os obstáculos detectados em duas classes principais: os obstáculos estáticos e móveis. Uma vez identificado o obstáculo...

‣ Main obstacles in the business environment affecting firm growth: a comparative analysis between chinese and brazilian SMEs

Tricaud, Chloé Sandrine Hélène
Fonte: Fundação Getúlio Vargas Publicador: Fundação Getúlio Vargas
Tipo: Dissertação
Português
Relevância na Pesquisa
47.04763%
Usando dados do Banco Mundial, esta dissertação analisa as semelhanças e diferenças entre os obstáculos enfrentados pelas micro, pequenas e médias empresas (MSME) no Brasil e na China. Realizamos tanto uma análise comparativa entre os dos países como uma análise de clusters para confrontar os dados subjetivos e objetivos recolhidos, de modo a identificar o desempenho das empresas, levando em consideração as características dos países e o ambiente de negócios.; Using World Bank Data, this research analyzes the similarities and differences in the main obstacles faced by Chinese and Brazilian micro, small and medium enterprises (MSME). We performed both country and cluster analyses in order to confront subjective and objective data, with the aim to be able to identify firms’ behaviors according to their own characteristics and their country environment.

‣ Organismos geneticamente modificados (OGMs) : obstáculos à obtenção e uso no Brasil; Genetically modified organism (GMO) : research and use obstacles in Brazil

Cunha, Elza Angela Battaggia Brito da
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
Relevância na Pesquisa
37.340151%
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-graduação em Agronegócios, 2007.; O presente trabalho trata das dificuldades enfrentadas no Brasil por universidades, institutos de pesquisa, cooperativas rurais e empresas para obterem licença autorizando-os a efetuarem pesquisa com organismos geneticamente modificados (OGMs) voltados ao complexo agro-industrial e, posteriormente, autorização para a sua liberação comercial. O trabalho tem por objetivo geral determinar quais são os obstáculos que se interpõem no país à pesquisa e liberação comercial de OGMs destinados ao complexo agro-industrial e para tanto sustentou-se que os principais entraves sejam os seguintes: as exigências da legislação nacional de biossegurança de OGMs; as dificuldades das entidades públicas de pesquisa para negociarem os direitos de propriedade intelectual; e a existência incipiente de cooperação técnica e financeira entre as entidades de pesquisa pública e as empresas privadas. A pesquisa abrangeu os fatos ocorridos no Brasil relacionados à biotecnologia no período de doze anos a contar de 1995. Esse marco foi adotado considerando-se os efeitos jurídicos da primeira lei de biossegurança de OGMs vigente no país. O trabalho envolveu dois métodos de pesquisa: a exploratória e a descritiva. Na fase conceitual valeu-se da pesquisa exploratória por meio do levantamento bibliográfico...

‣ A reforma psiquiátrica no Distrito Federal : um estudo sobre os principais obstáculos ao processo de implementação; The psychiatric reform in the Brazilian Federal District : a study on the main obstacles to its implementation process

Zgiet, Jamila
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
Relevância na Pesquisa
37.049446%
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Serviço Social, 2010.; Esta pesquisa teve como objetivo conhecer os obstáculos à implementação da reforma psiquiátrica no Distrito Federal e seus determinantes. Para isso, vale-se de uma análise histórico-política sobre a atenção à saúde mental no Brasil e no Distrito Federal. No campo teórico, são apresentadas reflexões conceituais a respeito de termos comumente utilizados nesse campo de estudo, como loucura, saúde, doença e deficiência mental, sofrimento psíquico e outros. Parte-se da compreensão de que é possível promover invenção de saúde e não apenas reabilitação. É apresentada a legislação nacional a respeito das pessoas com transtorno mental, com ênfase na Lei 10.216/01, que marca a implantação da chamada reforma psiquiátrica no Brasil. A pesquisa de campo consistiu em averiguar as dificuldades enfrentadas por gestores, trabalhadores e usuários dos serviços de saúde mental, bem como em traçar o perfil da arena política nesse subsetor da saúde por meio de entrevistas semiestruturadas, grupos focais, análise documental e observação direta. Os obstáculos à concretização da política de saúde mental sob os parâmetros da reforma psiquiátrica no Distrito Federal passam...

‣ Teachers’ conceptions of, and obstacles to, sex education in portuguese primary schools

Anastácio, Zélia; Carvalho, Graça Simões de; Clément, Pierre
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Parte de Livro
Publicado em //2005 Português
Relevância na Pesquisa
47.248247%
Teachers’ conceptions result from the interaction between their scientific knowledge, their systems of values, and their social and professional practice. Obstacles to teaching sex education may have several origins: epistemological, didactical, psychological and social. The aim of this research is to identify teachers’ conceptions and obstacles, that prevent them from teaching sex education. We intend to apply several research instruments: questionnaires, debates, focus groups, individual interviews and specific cases registration. The research starting point was the questionnaire. Its preliminary results suggest that sexual intercourse, fertilisation and sexual pleasure are the most difficult content, that the environmental milieu, the community and the church are the main obstacles to teaching sex education, and that specific training for sex education teaching seems to be necessary.; European Science Education Research Association (ESERA).; nmw-essen - Research Group & Graduate School Teaching & Learning Science.

‣ Políticas de apoio às pequenas e médias empresas (PME) em Angola

Botelho, Eliseu de Jesus Van-Dúnem
Fonte: Instituto Universitário de Lisboa Publicador: Instituto Universitário de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2014 Português
Relevância na Pesquisa
47.147563%
Mestrado em Economia e Políticas Públicas; Esta pesquisa disserta o tema sobre as políticas de apoio às PME em Angola. O tópico é abordado sob a ótica de como o Governo Angolano apoia as PME no contexto atual. Esta pesquisa foi realizada na província de Luanda. A investigação tem como Objetivo analisar conhecer as possibilidades de financiamento das PME; identificar os principais obstáculos que limitam o desenvolvimento das PME; perceber que tipo de apoio o Governo tem dado às PME em Angola. Neste estudo optou-se pela metodologia descritiva (qualitativa), das políticas de apoio as PME e de algumas variáveis chaves no que diz respeito a análise teórica conceptual, unindo a um estudo empírico através de entrevistas realizadas. O resultado da análise de todos os dados revelou que os pequenos e médios empresários e os vendedores carecem de apoios, principalmente financeiros, institucionais, isto é, redução dos processos burocráticos, espaço físico para o desenvolvimento do negócio, por um lado. Por outro, as principais dificuldades encontradas aos empresários de PME e aos vendedores informais tem a ver com a falta de recursos qualificados, demasiada burocracia nas instituições governamentais e com falta de conhecimento das práticas moderna de gestão por parte dos empresários das PME e aos vendedores informais. Concluiu-se que muitos destes problemas têm a ver com o facto de existir atividades pouco produtivas motivadas pela sua própria sobrevivência de vida do praticante. Neste caso...

‣ Distinctiveness of psychological obstacles to recovery in low back pain patients in primary care

Foster, Nadine E.; Thomas, Elaine; Bishop, Annette; Dunn, Kate M.; Main, Chris J.
Fonte: Elsevier/North-Holland Publicador: Elsevier/North-Holland
Tipo: Artigo de Revista Científica
Publicado em /03/2010 Português
Relevância na Pesquisa
36.856855%
Many psychological factors have been suggested to be important obstacles to recovery from low back pain, yet most studies focus on a limited number of factors. We compared a more comprehensive range of 20 factors in predicting outcome in primary care. Consecutive patients consulting 8 general practices were eligible to take part in a prospective cohort study; 1591 provided data at baseline and 810 at 6 months. Clinical outcome was defined using the Roland and Morris Disability Questionnaire (RMDQ). The relative strength of the baseline psychological measures to predict outcome was investigated using adjusted multiple linear regression techniques. The sample was similar to other primary care cohorts (mean age 44 years, 59% women, mean baseline RMDQ 8.6). The 20 factors each accounted for between 0.04% and 33.3% of the variance in baseline RMDQ score. A multivariate model including all 11 scales that were associated with outcome in the univariate analysis accounted for 47.7% of the variance in 6 months RMDQ score; rising to 55.8% following adjustment. Four scales remained significantly associated with outcome in the multivariate model explaining 56.6% of the variance: perceptions of personal control, acute/chronic timeline, illness identify and pain self-efficacy. When all independent factors were included...

‣ HERC6 Is the Main E3 Ligase for Global ISG15 Conjugation in Mouse Cells

Oudshoorn, Diede; van Boheemen, Sander; Sánchez-Aparicio, Maria Teresa; Rajsbaum, Ricardo; García-Sastre, Adolfo; Versteeg, Gijs A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/01/2012 Português
Relevância na Pesquisa
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Type I interferon (IFN) stimulates expression and conjugation of the ubiquitin-like modifier IFN-stimulated gene 15 (ISG15), thereby restricting replication of a wide variety of viruses. Conjugation of ISG15 is critical for its antiviral activity in mice. HECT domain and RCC1-like domain containing protein 5 (HerC5) mediates global ISGylation in human cells, whereas its closest relative, HerC6, does not. So far, the requirement of HerC5 for ISG15-mediated antiviral activity has remained unclear. One of the main obstacles to address this issue has been that no HerC5 homologue exists in mice, hampering the generation of a good knock-out model. However, mice do express a homologue of HerC6 that, in contrast to human HerC6, can mediate ISGylation.

‣ Costa Rica : Competitiveness Diagnostic and Recommendations

World Bank
Fonte: World Bank Publicador: World Bank
Português
Relevância na Pesquisa
37.24022%
Costa Rica is a clear success story. The country enjoys the highest standard of living in Central America and one of the highest in Latin America and the Caribbean (LAC). Not surprisingly, poverty levels are among the lowest in LAC. Indeed in 2004, Costa Rica had the second lowest poverty headcount in LAC with just nine percent of households below the US$2 poverty line. This report is a contribution to those efforts. Based on multiple data sources, it assesses the main obstacles that affect private sector growth in Costa Rica and provides policy options and targeted interventions for improving the business environment and increasing competitiveness, with the goal of achieving sustained and broad-based growth. In this regard, the main focus of the report is on the long-term instead of on cyclical issues. This report outlines a program to address the critical bottlenecks that hamper Costa Rica in diverse fields including infrastructure, technological innovation and quality, human capital, red tape, and access to credit. The result is a rich and encompassing agenda. The rest of the report is structured in the following way. In section two...

‣ Bank Financing for SMEs around the World : Drivers, Obstacles, Business Models, and Lending Practices

Beck, Thorsten; Demirgüç-Kunt, Asli; Martínez Pería, María Soledad
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
Português
Relevância na Pesquisa
47.049443%
Using data from a survey of 91 banks in 45 countries, the authors characterize bank financing to small and medium enterprises (SMEs) around the world. They find that banks perceive the SME segment to be highly profitable, but perceive macroeconomic instability in developing countries and competition in developed countries as the main obstacles. To serve SMEs banks have set up dedicated departments and decentralized the sale of products to the branches. However, loan approval, risk management, and loan recovery functions remain centralized. Compared with large firms, banks are less exposed to small enterprises, charge them higher interest rates and fees, and experience more non-performing loans from lending to them. Although there are some differences in SMEs financing across government, private, and foreign-owned banks - with the latter being more likely to engage in arms-length lending - the most significant differences are found between banks in developed and developing countries. Banks in developing countries tend to be less exposed to SMEs...

‣ Obstacles in European competition law enforcement : a potential solution from collective redress

ZYGIMANTAS, Juska
Fonte: Instituto Universitário Europeu Publicador: Instituto Universitário Europeu
Tipo: Artigo de Revista Científica Formato: application/pdf; digital
Português
Relevância na Pesquisa
37.049446%
The primary focus of this article is to review the main obstacles in competition law enforcement in the European Union and to investigate how the development of collective redress could effectively facilitate enforcement of EU competition law. Arguably, antitrust enforcement remains sub-optimal due to the insufficient deterrent effect of EU antitrust fines and obstacles facing victims of competition law infringements in bringing damages actions. Central to my work, therefore, is the belief that collective actions constitute an attractive vehicle to solve, or at least diminish, the inefficienciesof antitrust enforcement. The paper explores some options as to how to design collective redress mechanisms in order to influence the ability to bring successful collective claims. This would, in turn, consider the advantages of opt-out collective actions in tackling the issues related to low participation rates, lack of funding and sub-optimal deterrence. From this perspective, the article moves on to propose collective actions as a potential remedy to facilitate access to justice, to deal with a wide range of legal and economic issues and to mitigate dysfunctional compensatory mechanism of EU antitrust enforcement.

‣ Career options and entrepreneurial potential among female graduates: motivations, obstacles and realities

Marques, Ana Paula
Fonte: EUSER (European Center for Science Education and Research) Publicador: EUSER (European Center for Science Education and Research)
Tipo: Artigo de Revista Científica
Publicado em /05/2015 Português
Relevância na Pesquisa
47.16796%
The objective of this paper is to contribute for a better understanding of the perceived motivations, obstacles and self-employment realities in the advanced technology sectors and knowledge intensive-business. In terms of public policies in economic and business, promoting female entrepreneurship emerges as a factor of mobilization of women for active economic life, as well as a strategy to support business initiatives, particularly as factor conducive to the promotion of equality between men and women. However, according to a recent study on the promotion of innovative women and entrepreneurship, one of the main obstacles that explains the lower participation of women in entrepreneurial activities of an innovative nature are related to educational choices pursued in formal education systems and the persistence of traditional stereotypes about women, science and innovation. Also, in comparison to men, women not only possess a lack positive attitudes about their own personal capacities or inclinations for starting businesses, but also have less personal contact with entrepreneurs. Empirical results are based on a case study project centred on a Portuguese University and the potential of entrepreneurship among graduates who have completed their course between 2002 and 2008. Drawing upon information-rich evidence from in-depth interviews...

‣ Career options and entrepreneurial potential among female graduates: motivations, obstacles and realities

Marques, Ana Paula
Fonte: EUSER Publicador: EUSER
Tipo: Conferência ou Objeto de Conferência
Publicado em //2015 Português
Relevância na Pesquisa
47.16796%
The objective of this paper is to contribute for a better understanding of the perceived motivations, obstacles and selfemployment realities in the advanced technology sectors and knowledge intensive-business. In terms of public policies in economic and business, promoting female entrepreneurship emerges as a factor of mobilization of women for active economic life, as well as a strategy to support business initiatives, particularly as factor conducive to the promotion of equality between men and women. However, according to a recent study on the promotion of innovative women and entrepreneurship, one of the main obstacles that explains the lower participation of women in entrepreneurial activities of an innovative nature are related to educational choices pursued in formal education systems and the persistence of traditional stereotypes about women, science and innovation. Also, in comparison to men, women not only possess a lack positive attitudes about their own personal capacities or inclinations for starting businesses, but also have less personal contact with entrepreneurs. Empirical results are based on a case study project centred on a Portuguese University and the potential of entrepreneurship among graduates who have completed their course between 2002 and 2008. Drawing upon information-rich evidence from in-depth interviews...

‣ NATO membership for Bosnia and Herzegovina obstacles and challenges

Katica, Jasmin
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xviii, 117 p. : maps (some col.) ;
Português
Relevância na Pesquisa
37.049446%
In order to provide for its future security, Bosnia and Herzegovina aspires to NATO membership. It intends to be not only a consumer of security, but also a provider of security for its allies. Because of the history and specific regional context of its relations with its neighbors, Bosnia and Herzegovina faces many obstacles. Although Bosnia and Herzegovina is still engaged in a stabilization and reconstruction process, Sarajevo is trying to find the best possible way to achieve the goal of NATO membership. This thesis analyzes the main obstacles on the way to NATO membership, identifies ways to surmount them, and offers some recommendations for future policy. This thesis will, it is hoped, be beneficial to policymakers, who need to promote focused and united national efforts and to generate synergy to help Bosnia and Herzegovina successfully achieve NATO membership and thereby secure a better future for the country and Europe as a whole.; Air Forces of Bosnia and Herzegovina author.

‣ Ukraine : Trade Policy Study, Volume 1. Main Conclusions and Recommendations

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Foreign Trade, FDI, and Capital Flows Study; Economic & Sector Work
Português
Relevância na Pesquisa
36.841387%
The main objectives of this study are the following: 1) foster a better understanding of key drivers of recent trade performance; 2) assess current trade policies and provide additional recommendations to strengthen the Government's trade integration strategy; 3) identify core bottlenecks in the ongoing integration processes, especially with WTO accession; and 4) develop recommendations for Ukraine's international partners to provide Ukraine with a level playing field in terms in international trade, and the government with additional technical assistance that would help Ukraine upgrade its trade policies and institutions. The report's main messages are: The current trade patterns are unsustainable in the longer term because they depend heavily on temporary factors. Significant export diversification is critical for export to become a reliable source of future economic growth. The main obstacles to furthering Ukraine's trade integration are domestic and relate to serious deficiencies in the business environment...

‣ Ukraine : Trade Policy Study, Volume 2. Main Report

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Foreign Trade, FDI, and Capital Flows Study; Economic & Sector Work
Português
Relevância na Pesquisa
36.841387%
The main objectives of this study are the following: 1) foster a better understanding of key drivers of recent trade performance; 2) assess current trade policies and provide additional recommendations to strengthen the Government's trade integration strategy; 3) identify core bottlenecks in the ongoing integration processes, especially with WTO accession; and 4) develop recommendations for Ukraine's international partners to provide Ukraine with a level playing field in terms in international trade, and the government with additional technical assistance that would help Ukraine upgrade its trade policies and institutions. The report's main messages are: The current trade patterns are unsustainable in the longer term because they depend heavily on temporary factors. Significant export diversification is critical for export to become a reliable source of future economic growth. The main obstacles to furthering Ukraine's trade integration are domestic and relate to serious deficiencies in the business environment...

‣ The parking policy and smart growth disconnect : obstacles to establishing and implementing smart growth parking policy

Richardson, Heather Eileen Seyfang
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 147 p.; 8594745 bytes; 8602997 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
36.856855%
Urban areas are plagued by congestion, economic inequality, and inefficient land use that result from highway and single family housing subsidies, segregated land uses, and many other government policies established over the last 80 years. Parking is one part of the complex and problematic system of traditional urban development that can benefit from a Smart Growth approach to urban livability. Parking is increasingly understood to be an underlying factor in traffic generation that leads to increasing vehicle miles traveled, congestion, and several other nuisances that arise from a growing number of vehicles on the road. Furthermore, parking increases the cost of living in urban areas where parking demand is high and supply is tight. Traditional growth patterns that encourage low density development with minimum free parking requirements exacerbate problems caused by parking. Smart Growth development counters traditional growth by offering mixed use development, maximum parking requirements, context sensitive design and focusing on increasing pedestrian and transit trips. After establishing the advantages of Smart Growth over traditional development for Boston, this thesis asks: why are the cities of Boston, Cambridge and Quincy not implementing Smart Growth when it could be better for everyone? Four case studies from the Boston Metropolitan Area (North Station...

‣ Obstáculos para el aprendizaje del modelo de evolución por selección natural; Obstacles in the learning of the model of evolution by natural selection

González Galli, Leonardo Martín
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 Português
Relevância na Pesquisa
37.167961%
Esta tesis doctoral se llevó a cabo con la intención de realizar una contribución original a la comprensión de los factores que dificultan la enseñanza y el aprendizaje del modelo de evolución por selección natural. Se intentó caracterizar las concepciones que utilizan estudiantes de secundaria y universidad para explicar la evolución de rasgos adaptativos e inferir los obstáculos subyacentes. También se realizó un análisis epistemológico del modelo mencionado a fin de identificar posibles rasgos del mismo que pudieran dificultar su enseñanza y su aprendizaje. Para alcanzar estos objetivos se implementaron métodos de investigación educativa de tipo cuantitativo y cualitativo, predominando este último enfoque. Se trabajó con dos poblaciones de estudiantes de diferentes niveles educativos: medio y universitario. La obtención de los datos incluyó, entre otras estrategias, cuestionarios y entrevistas, y el diseño y puesta en práctica de una unidad didáctica. La misma se llevó a la práctica en dos cursos de cuarto año de una escuela secundaria. Los resultados permitieron identificar numerosas concepciones alternativas (por ejemplo, la noción de transformación individual adaptativa) y tres obstáculos subyacentes: la teleología de sentido común...

‣ Experimental and large eddy simulation study of the flow developed by a sequence of lateral obstacles

García Villalba, M.; Niño Campos, Yarko Iván; Brevis, W.
Fonte: Springer Publicador: Springer
Tipo: Artículo de revista
Português
Relevância na Pesquisa
27.439023%
Artículo de publicación ISI; In this paper we provide a description of the three-dimensional flow induced by a sequence of lateral obstacles in a straight shallow open-channel flow with flat bathymetry. The obstacles are modelled as rectangular blocks and are located at one channel wall, perpendicular to the main stream direction. Two aspect ratios of the resulting dead zones are analysed. The flow structure is experimentally characterised by particle image velocimetry measurements in a laboratory flume and simulated using three-dimensional Large Eddy Simulations. Good agreement between experimental measurements and numerical results is obtained. The results show that the effect of the obstacles in the main channel is observed up to one obstacle length in the spanwise direction. The spacing between obstacles does not seem to have a large influence in the outer flow. The mean flow within the dead zone is characterised by a large recirculation region and several additional vortex systems. They are discussed in the paper, as well as the mean and root-mean-square wall shear-stresses.