287 research outputs found

    Sistemas de produção em policultivo de mandioca, milho e caupi para a microrregião Bragantina-Parå.

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    Temperature-independent torsion sensor based on “figure-of-eight” fiber loop mirror

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    An interrogation sensor system combining the “figure-of-eight” fiber loop mirror using a single directional 3×3 fiber optic coupler was proposed. One fiber loop mirror was formed by inserting a length of high birefringent optical fiber at the input ports of the 3×3 coupler. Splicing the output ports of the 3×3 coupler between them created the other fiber loop mirror. The introduction of this second loop gave rise to two polarization states of light with the same frequency but different optical phase. The mechanical torsion sensing head was located at the second loop and was exhibited an average modulus torsion sensitivity of 7.9×10−4 degree/dB. The performance of the sensor was not affected by environmental temperature variations.info:eu-repo/semantics/publishedVersio

    Hyperbolicity preserving HLL solver for two-layer shallow-water equations applied to dam-break flows

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    River morphodynamics and sediment transportDebris and hyperconcentrated flow

    Sistema de produção de juta-semente em consorcio com culturas alimentares.

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    Review of fiber-optic pressure sensors for biomedical and biomechanical applications

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    As optical fibers revolutionize the way data is carried in telecommunications, the same is happening in the world of sensing. Fiber-optic sensors (FOS) rely on the principle of changing the properties of light that propagate in the fiber due to the effect of a specific physical or chemical parameter. We demonstrate the potentialities of this sensing concept to assess pressure in biomedical and biomechanical applications. FOSs are introduced after an overview of conventional sensors that are being used in the field. Pointing out their limitations, particularly as minimally invasive sensors, is also the starting point to argue FOSs are an alternative or a substitution technology. Even so, this technology will be more or less effective depending on the efforts to present more affordable turnkey solutions and peer-reviewed papers reporting in vivo experiments and clinical trials.info:eu-repo/semantics/publishedVersio

    Suspended-core fibers for sensing applications

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    A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.info:eu-repo/semantics/publishedVersio

    Sistemas de produção de sementes de juta consorciada com milho para o município de Alenquer, Parå.

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    Assessment of the effectiveness of steel fibre reinforcement for the punching resistance of flat slabs by experimental research and design approach

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    The present paper deals with the experimental assessment of the effectiveness of steel fibre reinforcement in terms of punching resistance of centrically loaded flat slabs, and to the development of an analytical model capable of predicting the punching behaviour of this type of structures. For this purpose, eight slabs of 2550 x 2550 x 150 mm3 dimensions were tested up to failure, by investigating the influence of the content of steel fibres (0, 60, 75 and 90 kg/m3) and concrete strength class (50 and 70 MPa). Two reference slabs without fibre reinforcement, one for each concrete strength class, and one slab for each fibre content and each strength class compose the experimental program. All slabs were flexurally reinforced with a grid of ribbed steel bars in a percentage to assure punching failure mode for the reference slabs. Hooked ends steel fibres provided the unique shear reinforcement. The results have revealed that steel fibres are very effective in converting brittle punching failure into ductile flexural failure, by increasing both the ultimate load and deflection, as long as adequate fibre reinforcement is assured. An analytical model was developed based on the most recent concepts proposed by the fib Mode Code 2010 for predicting the punching resistance of flat slabs and for the characterization of the behaviour of fibre reinforced concrete. The most refined version of this model was capable of predicting the punching resistance of the tested slabs with excellent accuracy and coefficient of variation of about 5%.The study presented in this paper is a part of the research project titled "SlabSys-HFRC - Flat slabs for multi-storey buildings using hybrid reinforced self-compacting concrete: an innovative structural system", with reference number of PTDC/ECM/120394/2010. The second author acknowledges the support provided by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) grant, and the grant provided by the project SlabSys. The authors would acknowledge the collaboration of Casais Company on the preparation of the moulds and flexural reinforcement, CiviTest on the design of the SFRSCC for the slabs, and Maccaferri, Secil (Unibetao), and Sika companies for the supplying of steel fibres, concrete and superplasticizers, respectively

    A mutant of Metarhizium anisopliae var. acridum with enhanced submerged conidiation.

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    Made available in DSpace on 2018-06-06T01:01:38Z (GMT). No. of bitstreams: 1 ID278831.pdf: 343982 bytes, checksum: 1b1ebb921fe53464e93c15e17e4d406c (MD5) Previous issue date: 2007-01-16bitstream/item/178116/1/ID-27883-1.pd
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