1,843 research outputs found

    Comparative response spectrum analysis on 15- and 50-story reinforced concrete buildings having shear walls with and without openings as per EN1998-1 Seismic Code

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    Medium-rise reinforced concrete (RC) framed apartment complexes with stories ranging from 15 to 50 are becoming more common in Ethiopia’s main cities. In these RC-framed structures, shear walls are included for lateral load resistance. As apertures are frequently provided in shear walls, it is critical to evaluate their influence on story drift, stiffness, shear and moments, and stress within the shear walls. A 3D study with five different cases was carried out with ETABS version 19.00 software to investigate the influence of apertures in a building’s shear wall. This study looks at the effects of changing the size and location of these apertures. Based on this analysis, extensive data were acquired, and useful conclusions were formed that will be useful to practicing engineers. The seismic parameter utilized for the response spectrum study was Building Code of Ethiopia ES8-15, which conforms to Eurocode 8-2004 seismic code guidelines (based on EN1998-1) with target response spectrum type-I. The following parameters were used: ground acceleration, ag/g = 0.1, spectrum type = I, ground type = B, soil factor, S = 1.35, spectrum period, Tb, = 0.05 s, spectrum period, Tc = 0.25 s, spectrum period, Td = 1.2 s, lower bound factor, beta = 0.2, behavior factor = 1, and damping ratio = 5%. The outcomes are compared using various parameters such as displacement, story drift, story stiffness, story shear, and story moment both with and without shear wall opening cases. This study will give tremendous insight into the effect of shear wall openings on the performance of the structure. The analysis in this work was carried out on a linear model, which may not represent the complete local response of the structure; thus, future researchers should perform nonlinear analysis based on a performance-based design. It was concluded from this investigation that incorporating shear walls considerably enhanced the performance of the building over framed structures. Shear wall openings in a structure have a significant influence on the building’s performance. Due to their significant resistance to earthquake forces, shear wall structures are highly recommended for seismic hazard zones

    External and intrinsic anchoring in nematic liquid crystals: A Monte Carlo study

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    We present a Monte Carlo study of external surface anchoring in nematic cells with partially disordered solid substrates, as well as of intrinsic anchoring at free nematic interfaces. The simulations are based on the simple hexagonal lattice model with a spatially anisotropic intermolecular potential. We estimate the corresponding extrapolation length bb by imposing an elastic deformation in a hybrid cell-like nematic sample. Our estimates for bb increase with increasing surface disorder and are essentially temperature--independent. Experimental values of bb are approached only when both the coupling of nematic molecules with the substrate and the anisotropy of nematic--nematic interactions are weak.Comment: Revisions primarily in section I

    Controle genético da resistência a murcha-de-fusário em feijoeiro comum.

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    Os objetivos do trabalho foram avaliar o controle genético da reação ao agente causal da murcha-de-fusário, a partir dos cruzamentos Milionário 1732 x Macanudo e FT Tarumã x Macanudo, e estimar parâmetros genéticos que permitam selecionar famílias resistentes à doença

    Um magmatismo bimodal arqueano no âmbito dos complexos metamórficos do quadrilátero ferrífero e suas implicações tectônicas

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    Submitted by Pedro Henrique da Silva Assunção ([email protected]) on 2014-10-16T20:09:01Z No. of bitstreams: 1 ARTIGO_MagmatismoBimodalArqueano.pdf: 1143739 bytes, checksum: 1fbe9a68a5494ab0541505faaea6a092 (MD5)Approved for entry into archive by Gracilene Carvalho ([email protected]) on 2014-10-31T12:39:47Z (GMT) No. of bitstreams: 1 ARTIGO_MagmatismoBimodalArqueano.pdf: 1143739 bytes, checksum: 1fbe9a68a5494ab0541505faaea6a092 (MD5)Submitted by Pedro Henrique da Silva Assunção ([email protected]) on 2014-11-24T18:56:53Z No. of bitstreams: 1 ARTIGO_MagmatismoBimodalArqueano.pdf: 1143739 bytes, checksum: 1fbe9a68a5494ab0541505faaea6a092 (MD5)Approved for entry into archive by Oliveira Flávia ([email protected]) on 2014-11-24T19:11:15Z (GMT) No. of bitstreams: 1 ARTIGO_MagmatismoBimodalArqueano.pdf: 1143739 bytes, checksum: 1fbe9a68a5494ab0541505faaea6a092 (MD5)Made available in DSpace on 2014-11-28T15:56:57Z (GMT). No. of bitstreams: 1 ARTIGO_MagmatismoBimodalArqueano.pdf: 1143739 bytes, checksum: 1fbe9a68a5494ab0541505faaea6a092 (MD5) Previous issue date: 199

    Structure of Extreme Correlated Equilibria: a Zero-Sum Example and its Implications

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    We exhibit the rich structure of the set of correlated equilibria by analyzing the simplest of polynomial games: the mixed extension of matching pennies. We show that while the correlated equilibrium set is convex and compact, the structure of its extreme points can be quite complicated. In finite games the ratio of extreme correlated to extreme Nash equilibria can be greater than exponential in the size of the strategy spaces. In polynomial games there can exist extreme correlated equilibria which are not finitely supported; we construct a large family of examples using techniques from ergodic theory. We show that in general the set of correlated equilibrium distributions of a polynomial game cannot be described by conditions on finitely many moments (means, covariances, etc.), in marked contrast to the set of Nash equilibria which is always expressible in terms of finitely many moments

    Resposta de plantas jovens de limeira-ácida 'Tahiti' a diferentes níveis de irrigação

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    The aim of this study was to evaluate the effect of different irrigation levels on canopy and root growth, productivity, and fruit quality of young ‘Tahiti’ acid lime trees. The experiment was installed in Piracicaba, Brazil in a 1.0-ha orchard plot with ‘Tahiti’ acid lime trees, grafted on ‘Swingle’ citrumelo rootstock and carried out from August of 2002 to May 2005. Each treatment was assigned to a drip irrigation level, based on ETc as follows: T1) non-irrigated, T2) 25%, T3) 50%, T4) 75% and T5) 100% of ETc determined by weighing lysimeter presented in the orchard plot. Trunk diameter and tree height were evaluated monthly. The roots were evaluated when the trees were 30 and 48 months old. The yield and fruit quality was evaluated in 2004 and 2005. The results showed that irrigation did not influence root distribution in depth, and trees irrigated with 75% and 100% ETc showed horizontal root distribution concentrated until 0.6 m from the trunk. Irrigation did not improve the quality of fruit. Yield increased in all irrigated treatment, but the most efficient yield mean per unit of water applied was the 25% ETc treatment.O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de irrigação sobre o crescimento da copa e raízes, produtividade e qualidade de frutos de plantas jovens de limeira-ácida ‘Tahiti’. O experimento foi instalado em Piracicaba, em um hectare plantado com limeira-ácida ‘Tahiti’ enxertadas sobre porta-enxerto citromelo ‘Swingle’e irrigadas por gotejamento. O experimento foi conduzido durante o período de agosto de 2002 a maio de 2005. Cada tratamento correspondeu a um nível de irrigação baseado nos valores de evapotranspiração da cultura (ETc): T1) não irrigado; T2) 25%; T3) 50%; T4) 75% e T5) 100% da ETc determinada por meio de um lisímetro de pesagem, presente na área. O diâmetro e a altura das plantas foram avaliados mensalmente. As raízes foram avaliadas quando as plantas estavam com 30 e 48 meses de idade. A produtividade e a qualidade dos frutos foram avaliadas em 2004 e 2005. Os resultados mostraram que a irrigação não influenciou na distribuição do sistema radicular em profundidade, e que plantas irrigadas com lâminas de água equivalentes a 75 e 100% da ETc mostraram uma distribuição horizontal de raízes concentradas a 0,60 m de distância do tronco. Aos 48 meses, a irrigação não influenciou na distribuição do sistema radicular no perfil do solo. A irrigação não melhorou a qualidade dos frutos. A produtividade aumentou em todos os tratamentos irrigados, mas o tratamento correspondente à lâmina de 25% da ETc foi o mais eficiente por unidade de água aplicada
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