Desenvolvimento e projeto de colhedora de babaçu (Orbignya phalerata Mart.) para agricultura familiar nas regiões de matas de transição da Amazônia

O babaçu (Orbignya phalerata) é uma típica palmeira das matas de transição dos ecossistemas Amazônia/Cerrado e Amazônia/Caatinga, sendo de grande importância econômica, social e ambiental nestas regiões. Os produtos advindos dos babaçuais possibilitam renda para uma das camadas mais pobres da região amazônica e um dos entraves para a obtenção eficiente destes produtos é a colheita dos cocos de babaçu, que atualmente se faz no sistema extrativista. O objetivo deste trabalho foi realizar o desenvolvimento e projeto de uma colhedora de babaçu adaptável ao ambiente de trabalho da agricultura familiar e as características das matas de transição amazônicas. Para tal foram realizados estudos de literatura que nortearam as decisões e simplificações de projeto, assim como foram realizados os cálculos e desenhos da nova colhedora. O projeto foi realizado através de ferramentas de engenharia que apresentaram como resultados o memorial de cálculo que descreve o caminho técnico para o dimensionamento dos elementos constituintes da colhedora e a partir destes os desenhos detalhados dos elementos da nova máquina. Pelos desenhos detalhados suas considerações e decisões concluí-se que a colhedora de babaçu apresenta-se passível de ser construída com materiais nacionais de baixo custo, além de fácil operação, manutenção e com mínimo efeito sobre os babaçuais naturais.

Projeto e construção de uma bomba de pistões axiais tipo Swashplate de vazão variável

Pós-graduação em Engenharia Mecânica - FEG

Projeto, desenvolvimento e construção de um redutor/multiplicador de velocidades de baixo custo

This paper aims to present the design, development and construction of a reducer / multiplier speeds low cost, sturdy and easy operation. The beginning of the project was given to research on issues related to mechanisms and machine elements, and these theories of fundamental importance in the development of items of equipment which, together with the aid of AutoCAD software, enabled the construction of it. Parallel to the sizing of equipment, were also investigated and taken into account the costs of materials used in the project. Made to mount the reducer / multiplier speeds it was at the evidence through experiments involving the use of torque wrench, tachometer and weights, getting proven applicability in situations that are small or medium loads required

Projeto mecânico de um redutor de engrenagens sem-fim numa esteira transportadora inclinada

This work aims to present the design and development of a speed reducer worm gear that will be implemented on an inclined treadmill that aims to raise the load below the top floor. The project start was made with research on issues related to mechanisms and machine elements, and these theories of fundamental importance in the development of device components, along with the help of SolidWorks software that was used to model the main parts of the project and Microsoft Office Excel 2007 was used to alight formulas to perform calculations of the project. All data for calculations were taken from the conditions of the problem to be solved in the best possible way the proposed problem (lifting load from the belt). Following the entire sequence of design gearbox assembly, beginning in pre-sizing and endless selection of electric motor, which consists of an iterative project, then scaling the worm gear and crown, shafts, splines, calculation and bearing selection

Análise de falhas por fadiga num rotor de hidrogerador vertical via método dos elementos finitos

Pós-graduação em Engenharia Mecânica - FEG

Soil compaction by machine traffic and least limiting water range related to soybean yield

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Proposta de uma máquina para colheita mecanizada de babaçu (Orbignya phalerata Mart.) para a agricultura familiar

O babaçu é uma planta de importância capital na economia de subsistência do norte do Brasil. Sua configuração sócio-ambiental o torna destaque na situação regional amazônica, onde os produtos advindos do babaçu possibilitam renda para a camada mais pobre da população amazônica, além da questão ambiental que é conotada à preservação dos babaçuais naturais. Um dos gargalos técnicos da produção do babaçu, em especial visando a extração do óleo de babaçu, é a colheita feita de forma manual e no sistema extrativista. O objetivo deste trabalho é propor o conceito de uma colhedora de babaçu moto-mecanizada, capaz de trabalhar em cultivos artificiais, assim como em florestas naturais. Foi utilizada a metodologia de projeto da matriz morfológica, onde foram elencadas as possíveis combinações de mecanismos e elementos para uma colhedora de babaçu. Como resultado foi obtido um conceito teórico, sendo concluída a viabilidade técnica de tal projeto, em estudos futuros pretende-se desenvolver estudos de viabilidade técnica detalhados, assim como estudos de viabilidade econômica.

Aquatic weed automatic classification using machine learning techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Extração de feições retas com precisão subpixel: estudo comparativo entre três métodos

In the fields of Machine Vision and Photogrammetry, extracted straight lines from digital images can be used either as vector elements of a digital representation or as control entities that allow the determination of the camera interior and exterior orientation parameters. Applications related with image orientation require feature extraction with subpixel precision, to guarantee the reliability of the estimated parameters. This paper presents three approaches for straight line extraction with subpixel precision. The first approach considers the subpixel refinement based on the weighted average of subpixel positions calculated on the direction perpendicular to the segmented straight line. In the second approach, a parabolic function is adjusted to the grey level profile of neighboring pixels in a perpendicular direction to the segmented line, followed by an interpolation of this model to estimate subpixel coordinates of the line center. In the third approach, the subpixel refinement is performed with a parabolic surface adjustment to the grey level values of neighboring pixels around the segmented line. The intersection of this surface with a normal plane to the line direction generates a parabolic equation that allows estimating the subpixel coordinates of the point in the straight line, assuming that this is the critical point of this function. Three experiments with real images were made and the approach based on parabolic surface adjustment has presented better results.

HOW FAR do WE GET USING MACHINE LEARNING BLACK-BOXES?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diffusion of Interstitial Elements in Ti Alloys used as Biomaterials

Titanium alloys are excellent implant materials for orthopedic applications due to their desirable properties, such as good corrosion resistance, low elasticity modulus, and excellent biocompatibility. The presence of interstitial elements (such as oxygen and nitrogen) causes strong changes in the material's mechanical properties, mainly in its elastic properties. Study of the interaction among interstitial elements present in metals began with Snoek's postulate, that a stress-induced ordering of interstitials gives rise to a peak in the mechanical relaxation (internal friction) spectra. In the mechanical relaxation spectra, each species of interstitial solute atom gives rise to a distinct Snoek's peak, whose temperature and position depend on the measurement frequency. This effect is very interesting because its peculiar parameters are directly related to the diffusion coefficient (D) for the interstitial solute. This paper presents a study of diffusion of heavy interstitial elements in Ti-35Nb-7Zr-5Ta alloys using mechanical spectroscopy. Pre-exponential factors and activation energies are calculated for oxygen and nitrogen in theses alloys.

The Quasi-lattice of Indiscernible Elements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prolapse-free relativistic Gaussian basis sets for the superheavy elements up to Uuo (Z=118) and Lr (Z=103)

Prolapse-free basis sets suitable for four-component relativistic quantum chemical calculations are presented for the superheavy elements UP to (118)Uuo ((104)Rf, (105)Db, (106)Sg, (107)Bh, (108)Hs, (109)Mt, (110)Ds, (111)Rg, (112)Uub, (113)Uut, (114)Uuq, (115)Uup, (116)Uuh, (117)Uus, (118)Uuo) and Lr-103. These basis sets were optimized by minimizing the absolute values of the energy difference between the Dirac-Fock-Roothaan total energy and the corresponding numerical value at a milli-Hartree order of magnitude, resulting in a good balance between cost and accuracy. Parameters for generating exponents and new numerical data for some superheavy elements are also presented. (c) 2007 Elsevier B.V. All rights reserved.

Modeling of interfaces in two-dimensional problems using solid finite elements with high aspect ratio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A mixture theory based method for three-dimensional modeling of reinforce concrete members with embedded crack finite elements

The paper presents a methodology to model three-dimensional reinforced concrete members by means of embedded discontinuity elements based on the Continuum Strong Discontinuous Approach (CSDA). Mixture theory concepts are used to model reinforced concrete as a 31) composite material constituted of concrete with long fibers (rebars) bundles oriented in different directions embedded in it. The effects of the rebars are modeled by phenomenological constitutive models devised to reproduce the axial non-linear behavior, as well as the bond-slip and dowel action. The paper presents the constitutive models assumed for the components and the compatibility conditions chosen to constitute the composite. Numerical analyses of existing experimental reinforced concrete members are presented, illustrating the applicability of the proposed methodology.