6,357 research outputs found
Modelling of atmospheric boundary layer: Generation of shear.
Roughness length, z0 and friction velocity, u* are the defining parameters of wind log profile that must be matched in wind tunnel simulation. To fully understand the role of these parameters, the basics and review from the primitive equations and its relation to the logarithmic profile obtained for wind tunnel conditions were discussed. The problem of roughness, although well known, still needs to be addressed more rigorously especially when determining values of z0 and u* from wind tunnel data and their relation to the roughness element geometry. A review of classic literature and new published material were carried out, focusing on the applicability to wind tunnel modelling
Capoeira : práticas culturais do recôncavo baiano e o processo pedagógico criativo inclusivo
Este tema enquadra-se no âmbito de um projeto de doutoramento, desenvolvido através do Centro de
Formação de Professores da UFRB/Brasil, enquadrado na área temática - Educação, Desenvolvimento e
Expressões Artísticas. Propõe atividades vinculadas ao estudo da Cultura corporal, a partir das práticas
culturais do recôncavo baiano, na formação de pessoas com deficiência/doença mental e/ou em situação
de risco social e pessoal, com intuito de responder às dificuldades e perspetivas da ação pedagógica,
considerando o impacto educativo da musicalidade, movimento corporal e a dinamica das relações
interpessoais. Explora uma educação inclusiva a partir da reflexão sobre alternativas no trato com a
capoeira, samba, maculele, entre outras, para melhoria de questões que variam desde a cognição até de
auto-estima e identitárias, consignadas numa proposta de implementação de uma atividade de
enriquecimento curricular, em articulação com o currículo formal. Com este interesse foi traçada uma
metodologia centrada numa perspectiva qualitativa, a partir de um estudo de caso, considerando a
realidade de uma escola municipal. Assim, além de se observar significativos impactos na perspetiva de
inclusão destas pessoas, promovem-se práticas culturais e articula-se pesquisa, ensino e extensão,
garantindo o papel formativo e social da UFRB junto da comunidade da cidade de Amargosa e a
possibilidade de experimentar uma intervenção pedagógica criativa inclusiva com estudantes de Educação.Fundação para a Ciência e a Tecnologia (FCT
Pathway Weathering in Granitoid Rocks from Central Region of Angola: Geochemical and Mineralogical Data
The Central Region of Angola is characterized by the abundance of granitoid rocks, whose weathering “in situ” originated the so-called residual soils. The textural, geochemical and mineralogical properties of these soils depend not only on the chemical composition of parent rock, but mainly on the local climatic and geomorphological characteristics.
In the study area, sampling sites were selected, which extend from the region of Kwanza- Norte (Kassenda, Dondo) through Kwanza-Sul (Cangulo, Quibala and Waco Kungo) until the plateau of Huambo, where samples of fresh rock, weathered rock and its residual soil were collected along each weathering profile.
Chemical analytical data were determined using X-ray fluorescence (XRF) analysis of the major and minor elements, whereas mineralogical data were determined using X-ray diffraction (XRD), on the samples of rock and on the respective residual soil.
The results obtained and their comparative analysis between the sampling sites, as well as along each weathering profile is presented.
This paper allows contributing to the knowledge of the geochemical weathering in tropical areas, as is the case of Angola
Estruturas mistas no contexto da pré fabricação: alternativa à ligação viga-laje pré-fabricada.
O intenso processo de industrialização sofrido pela construção civil nos últimos anos está associado à busca por sistemas estruturais e/ou construtivos que visem à racionalização da construção, entre os quais se destacam os sistemas mistos de aço e concreto. Um sistema misto de aço-concreto visa extrair o máximo desempenho dos materiais. Para tanto, é necessário que se garanta a melhor interação possível entre os materiais. Nesse contexto, o comportamento das conexões entre os elementos de aço e concreto pré-fabricado, é um fator determinante na escolha do sistema construtivo. O presente trabalho apresenta e discute soluções para a conexão entre a viga metálica e a laje de concreto, tendo como enfoque as ligações por aderência. São apresentadas tanto soluções que utilizam conectores do tipo Pino, mais usuais, até às mais recentes soluções, no caso, as ligações por aderência, que tem se demonstrado bastante promissora em termos de resistência. Por fim, são apresentados resultados específicos de novas soluções para a conexão viga-laje, no contexto de uma solução pré-fabricada.The intense process of industrialization suffered by construction in recent years is associated with the search
for structural and/or constructive systems aiming the rationalization of construction, among which stand out
the composite systems of steel and concrete. A composite system of steel-concrete aims to extract
maximum performance of materials. Therefore, it is necessary to ensure the interaction between these
materials. In this context, the behavior of connections between elements of steel and precast concrete is a
determining factor in the choice of the structural system. This paper presents and discusses solutions to the
connection between the steel beam and concrete slab, with the focus on the connections by adherence. Are
presented as solutions that utilize stud connectors, more usual, as the latest solutions, connections by
adherence, which has been shown quite promising in terms of strength. Finally is presented specific results
of new solutions for the beam-slab connection in the context of prefabrication
Experimental analysis of new interfaces for connections by adhesion, interlocking and friction.
The authors thank the federal agency CAPES and the Foundation for Research Support of the state of Sao Paulo, Brazil (FAPESP) for providing a PhD scholarship, and the University of Minho, in Portugal, for the international collaboration.This paper presents the results of an experimental program developed to investigate the behavior of an innovative technology for connections by adhesion, interlocking and friction in composite structures. Connections have a strategic importance for precast concrete and steel–concrete composite structures, since they determine the global structural behavior and affect the whole production process, fromexecution to assemblage and other services on site. Currently, however, steel–concrete composite connections are not completely adapted for their use in prefabricated slabs. In this way, the development of new types of connections is clearly necessary, where connections by adherence (or connections by adhesion, interlocking and friction) seem quite promising. To improve the knowledge in the field of connections by adherence, this paper proposes a new geometry of embossments in the steel and in the concrete surfaces associatedwith the use of a high performance mortar.Monotonic push-out tests are performed, and their results are presented and discussed. A satisfactory behavior of the proposed connection in terms of strength is observed, justifying further studies on the subject.CAPES, FAPES
Tests on composite beams using new connections by adherence
Cast in place concrete is often the cheapest solution in the context of conventional construction. However, prefabrication presents advantages in terms of execution time, quality of the structural elements and cost. Thus, the association of precast concrete elements and steel sections in a composite element can result in a high quality structure, executed with greater speed and economy of financial and material resources. Currently, steel to concrete composite connections are not completely adapted to prefabricated slabs and the use of connections by adhesion, interlocking and friction seem quite promising. To improve the knowledge in this field, this paper presents the development of full scale flexural tests of composite beams using new interfaces for these connections, and their results are interpreted and discussed. For comparison purposes, two beams with cast in place slab are tested. A satisfactory behavior in terms of strength is observed, in both cases investigated (cast in place and precast slab), justifying further studies on the subject.info:eu-repo/semantics/publishedVersio
Experimental analysis on steel reinforced glass beams at different temperatures
This work is funded by FEDER Funds, through the Operational Programme Competitiveness
Factors – COMPETE, and Portuguese Funds, through FCT - Foundation for Science and Technology, under the project PTDC/ECM/116609/2010, “S-GLASS: Structural Performance and
Design Rules of Glass Beams Externally Reinforced”.
In addition, The COST Action TU0905 ‘‘Structural Glass – Novel Design Methods and Next Generation Products’’ is also acknowledged.Whereas glass components were used as infill elements in the past, contemporary architectural concepts include glass components as load-bearing elements. Recent architectural trends and technological developments have brought about unprecedented opportunities in the use of glass in buildings. The increasingly daring structural applications of glass will continue to drive the development of structural glass elements with high post-failure resistances.
The present work aims to explore the concepts of structural performance of glass beams and the effectiveness of an embedded steel reinforcement system. The reinforcement system consists in embedding perforated stainless steel plates in the lamination process. The experimental study focuses on the effect of thermal actions and compares the use of soft foils and stiff foils (temperature ranging from approximately 16 ºC to 85 ºC).Fundação para a Ciência e a Tecnologia (FCT
A Spectral Bernstein Theorem
We study the spectrum of the Laplace operator of a complete minimal properly
immersed hypersurface in . (1) Under a volume growth condition on
extrinsic balls and a condition on the unit normal at infinity, we prove that
has only essential spectrum consisting of the half line .
This is the case when , where
is the extrinsic distance to a point of and are the
principal curvatures. (2) If the satisfy the decay conditions
, and strict inequality is achieved at some point
, then there are no eigenvalues. We apply these results to minimal
graphic and multigraphic hypersurfaces.Comment: 16 pages. v2. Final version: minor revisions, we add Proposition 3.2.
Accepted for publication in the Annali di Matematica Pura ed Applicata, on
the 05/03/201
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