8,202 research outputs found
Recycled steel fibre reinforced concrete failing in bending and in shear
Recent research is showing that the addition of Recycled Steel Fibres
(RSF) from wasted tyres can decrease significantly the brittle behaviour of cement
based materials, by improving its toughness and post-cracking resistance. In this
sense, Recycled Steel Fibre Reinforced Concrete (RSFRC) seems to have the
potential to constitute a sustainable material for structural and non-structural
applications. To assess this potential, experimental and numerical research was
performed on the use of RSFRC in elements failing in bending and in beams failing in shear. The values of the fracture mode I parameters of the developed RSFRC
were determined by performing inverse analysis with test results obtained in three
point notched beam bending tests. To assess the possibility of using RSF as shear
reinforcement in Reinforced Concrete (RC) beams, three point bending tests were
executed with three series of RSFRC beams flexurally reinforced with a relatively
high reinforcement ratio of longitudinal steel bars in order to assure shear failure
for all the tested beams. By performing material nonlinear simulations with a
computer program based on the finite element method (FEM), the applicability of
the fracture mode I crack constitutive law derived from the inverse analysis is
assessed for the prediction of the behaviour of these beams. The performance of
the formulation proposed by RILEM TC 162 TDF and CEB-FIP 2010 for the
prediction of the shear resistance of fibre reinforced concrete elements was also
evaluated.The present study is part of the activities carried out by the Authors within the "EnCoRe" Project (FP7-PEOPLE-2011-IRSES no. 295283; www.encore-fp7-unisa.it) funded by the European Union within the Seventh Framework Programme. The authors wish also to acknowledge the support provided by Civitest and BioSafe companies
Classification of areas using pixel-by-pixel and sample classifiers
There are no author-identified significant results in this report
Apicultura e bovinocultura de corte: comparativo econômico da implantação hipotética dessas atividades no Pantanal.
Esta publicação foi realizada na forma de um comparativo econômico hipotético entre duas atividades econômicas que podem ser desenvolvidas, simultaneamente ou não, nas propriedades da região pantaneira: a apicultura (alternativa) e a bovinocultura de corte (tradicional). Dessa forma, buscou-se que os parâmetros, produtivos e econômicos de ambas as atividades, considerados nos cálculos fossem os mais realistas possíveis para as condições de uma propriedade (fazenda São Luiz), localizada no Pantanal do Abobral, que foi dedicada tradicionalmente à bovinocultura de corte e na qual o proprietário futuramente pretende instalar a apicultura. Portanto, os critérios e parâmetros avaliados neste comparativo econômico podem contribuir para a tomada de decisões de outros produtores rurais que pretendem desenvolver essas duas atividadesprodutivas em outras propriedades pantaneiras.bitstream/CPAP/56603/1/DOC84.pdfFormato Documento Eletrônico
Inovações tecnológicas, investimentos financeiros e gestão de sistema de produção animal em pastagens.
Cultivo da soca de arroz irrigado: uma alternativa para o aumento da rentabilidade da rizicultura do baixo São Francisco.
bitstream/item/82087/1/CPATC-COM.-TEC.-32-99.pd
Closed trajectories of a particle model on null curves in anti-de Sitter 3-space
We study the existence of closed trajectories of a particle model on null
curves in anti-de Sitter 3-space defined by a functional which is linear in the
curvature of the particle path. Explicit expressions for the trajectories are
found and the existence of infinitely many closed trajectories is proved.Comment: 12 pages, 1 figur
Group Theory analysis of phonons in two-dimensional Transition Metal Dichalcogenides
Transition metal dichalcogenides (TMDCs) have emerged as a new two
dimensional materials field since the monolayer and few-layer limits show
different properties when compared to each other and to their respective bulk
materials. For example, in some cases when the bulk material is exfoliated down
to a monolayer, an indirect-to-direct band gap in the visible range is
observed. The number of layers ( even or odd) drives changes in space
group symmetry that are reflected in the optical properties. The understanding
of the space group symmetry as a function of the number of layers is therefore
important for the correct interpretation of the experimental data. Here we
present a thorough group theory study of the symmetry aspects relevant to
optical and spectroscopic analysis, for the most common polytypes of TMDCs,
i.e. , and , as a function of the number of layers. Real space
symmetries, the group of the wave vectors, the relevance of inversion symmetry,
irreducible representations of the vibrational modes, optical selection rules
and Raman tensors are discussed.Comment: 32 pages, 4 figure
Thermodynamic and dynamic anomalies for a three dimensional isotropic core-softened potential
Using molecular dynamics simulations and integral equations (Rogers-Young,
Percus-Yevick and hypernetted chain closures) we investigate the thermodynamic
of particles interacting with continuous core-softened intermolecular
potential. Dynamic properties are also analyzed by the simulations. We show
that, for a chosen shape of the potential, the density, at constant pressure,
has a maximum for a certain temperature. The line of temperatures of maximum
density (TMD) was determined in the pressure-temperature phase diagram.
Similarly the diffusion constant at a constant temperature, , has a maximum
at a density and a minimum at a density .
In the pressure-temperature phase-diagram the line of extrema in diffusivity is
outside of TMD line. Although in this interparticle potential lacks
directionality, this is the same behavior observed in SPC/E water.Comment: 16 page
Desempenho de cultivares de sorgo sacarino para produção de etanol em diferentes épocas de semeadura, no município de Pelotas, RS.
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