Planejamento de experimentos em blocos aplicado às propriedades mecânicas de arames de aço para molas

The purpose of this article is to demonstrate an application of the design of block experiments via analysis and multiple linear regression in the investigation of a steel thermal treatment process with multiple responses. The study aimed to design statistical models to predict the mechanical properties in SAE 9254 draw steel wires, with diameters of 2.00 mm and 6.50 mm, after quench hardening and tempering. For this purpose, process input variables (wire diameter, processing speed, tempering temperature and polymer concentration) were investigated regarding their influence on the material tensile strength, yield point and hardness. The results revealed that the mechanical properties of the steel wire are significantly influenced by the selected variables, and analysis of variance (ANOVA) was employed to validate the design of the statistical models. Multiple linear regression allowed for an appropriate representation of the process, and graphical analysis was found to be very useful in displaying the behavior of the multiple responses.

Estudo da influência das características químicas e microestruturais nas propriedades mecânicas de sistemas totalmante cerâmicos

Pós-graduação em Odontologia Restauradora - ICT

Desenvolvimento de um eletrodo modificado com monocamadas auto-organizadas e sua utilização como biossesor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de biossensor baseado em extrato de açaí e sensor biomimético para detecção de hexazinona

Pós-graduação em Química - IQ

Influência da temperatura e do pH do meio sobre a resistência à corrosão das ligas Al(20204-T3), Al(7010-T7) e Al(7050-T7) utilizadas na indústria aeronáutica

Pós-graduação em Engenharia Mecânica - FEG

Síntese e caracterização de complexos de naproxeno com lantanídeos (III) e ítrio (III) no estado sólido com exceção do promécio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação da condução elétrica em fitas duplas de dna imobilizadas em eletrodos de ouro por medidas eletroquímicas

Pós-graduação em Química - IQ

Incorporação do carbono13 nos tecidos muscular e hepático de frangos de corte de diferentes grupos genéticos criados em estresse cíclico de calor

Pós-graduação em Zootecnia - FCAV

Modelagem e otimização por metodologia de superfícies de resposta: um estudo em arames de aço SAE 9254 para molas automobilísticas

Pós-graduação em Engenharia Mecânica - FEG

RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

Recently, in [7] we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the alpha'(N) terms of the OSLEEL using open superstring n-point amplitudes in which n is considerably lower than (N + 2) (which is the order of the required amplitude to obtain those alpha'(N) terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger [21], using the pure spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N = 4, 5, 6 and 7). Also, following the spirit of the revisited S-matrix approach, we have found the alpha' expansions for these amplitudes up to alpha'(6) order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).

Glucose biosensor based on multisegment nanowires exhibiting reversible magnetic control

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

Electrochemical study of arsenopyrite weathering

Cyclic voltammograms and capacitance measurements are presented to characterize the mineral response at relatively moderate environmental conditions, pH 4.5 and T = 25degreesC. The experiments involve examining the rates of oxidation and the surface morphology of arsenopyrite, which is oxidized abiotically. The semiconducting properties of the mineral have been investigated in attempt to gain additional information of FeAsS dissolution behavior in acidic solutions at potentials close to the open circuit potential of the mineral. A mechanistic pathway for the anodic dissolution of arsenopyrite in open circuit conditions is also suggested. At high overpotentials, anodic reactions produce mainly sulfate and arsenate ions and may be described as hole limited. The reduction of orpiment-like compounds at potentials more negative than the open circuit potential is discussed.

Electroanalytical determination of bumetanide employing a biomimetic sensor for detection of doping in sports

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das características térmicas e mecânicas de formulações de adesivos PSA HOT MELT contendo variações de borrachas SBC e resinas taquificantes

The properties of the hot melt adhesive pressure sensitive (HMPSA) using an elastomer as a base polymer a copolymer of styrene and butadiene (SBS) and variation of tackifiers resins such as hydrocarbon resins and hydrogenated hydrocarbon were investigated. The formulations were prepared by mixing process within shear. The adhesives prepared were evaluated in test Brookfield viscosity and softening point Ring and Ball to compare the formulations and the influence of variations in raw materials. Infrared analyzes were performed to detect the reactions between the inputs and investigate the chemical interactions of the same properties of the adhesive. In thermal analysis, the assay was performed thermogravimetry (TG) and diferencial exploratory calorimetry (DSC). Were investigated the parameters of the tensile test on each of the formulations. Finally, were analysed comparatively the basic formulations of adhesives with their respective raw materials

Estudo da reação de oxidação de metanol sobre fases intermetálicas ordenadas de AuIn, AuSn e AuSb2 em meio alcalino

The present work assessment materials can be used as fuel cells electrocatalysts. The alkaline fuel cell though was less studied, has some advantages compared to the acid configuration. The materials assesment were Au polycrystalline and intermetallics ordered phases of AuIn, AuSn and AuSb2. Your electrocatalytic properties were studied across cyclic voltametry and chronoamperometry techniques in Sodium Hydroxide 0,15M and Metanol 0,15M solution. The results obtained show a more efficiency to intermetallic AuIn as electrocatalyst for the oxidation reaction of methanol in alkaline medium, it showed high levels of current density and on set potential less positive compared to Au polycrystalline. The intermetallic AuSn showed activity just higher concentrations of methanol. Except AuSb2, who represented himself unstable in alkaline media, the intermetallics AuIn and AuSn present a promising future as anode materials for the oxidation in alkaline medium