Suppression of vibrations in a nonlinear half-car model using a magneto-rheological damper

The present work investigates the nonlinear response of a half-car model. The disturbances of the road are assumed to be sinusoidal. After constructing the bifurcation diagram, we use the 0-1 test to identify chaotic motions. The main objective of this study is to eliminate chaotic behavior of the chassis and reduce its vibrations. To accomplish this, a semi-active vehicle suspension control system, using magneto-rheological dampers, is proposed. The proposed semi-active control strategy consists of two nonlinear control laws: a feedforward control, and a feedback control. They are obtained by considering the SDRE (State Dependent Riccati Equation) control, where the control parameter is the voltage applied to the coils of the magneto-rheological dampers. Numerical results show that the proposed control method is effective in significantly reducing of the chassis vibration, increasing, therefore, passenger comfort.

Nanopartículas de alginato como sistema de liberação para o herbicida clomazone

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

Desenvolvimento e caracterização de nanocápsulas de poli (L-lactídeo) contendo benzocaína

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

Characterization of Atrazine-Loaded Biodegradable Poly(Hydroxybutyrate-Co-Hydroxyvalerate) Microspheres

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

Características produtivas e imunológicas de frangos de corte submetidos a dietas suplementadas com cromo, criados sob diferentes condições de ambiente

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

Physical quality of an Oxisol cultivated with maize submited to cover crops in the pre-cropping period

The intensive use of land alters the distribution of the pore size which imparts consequences on the soil physical quality. The Least Limiting Water Range (LLWR) allows for the visualization of the effects of management systems upon either the improvement or the degradation of the soil physical quality. The objective of this study was to evaluate the physical quality of a Red Latosol (Oxisol) submited to cover crops in the period prior to the maize crop in a no-tillage and conventional tillage system, using porosity, soil bulk density and the LLWR as attributes. The treatments were: conventional tillage (CT) and a no-tillage system with the following cover crops: sunn hemp (Crotalaria juncea L.) (NS), pearl millet (Pennisetum americanum (L.) Leeke) (NP) and lablab (Dolichos lablab L.) (NL). The experimental design was randomized blocks in subdivided plots with six replications, with the plots being constituted by the treatments and the subplots by the layers analyzed. The no-tillage systems showed higher total porosity and soil organic matter at the 0-0.5 m layer for the CT. The CT did not differ from the NL or NS in relation to macroporosity. The NP showed the greater porosity, while CT and NS presented lower soil bulk density. No <= 10 % airing porosity was found for the treatments evaluated, and value for water content where soil aeration is critical (theta(PA)) was found above estimated water content at field capacity (theta(FC)) for all densities. Critical soil bulk density was of 1.36 and 1.43 Mg m(-3) for NP and CT, respectively. The LLWR in the no-tillage systems was limited in the upper part by the theta(FC), and in the bottom part, by the water content from which soil resistance to penetration is limiting (theta(PR)). By means of LLWR it was observed that the soil presented good physical quality.

Avaliação dos atributos físicos de um Nitossolo Vermelho distroférrico sob sistema plantio direto, preparo convencional e mata nativa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Co-cultivation of plant cells as a technique for the elicitation of secondary metabolite production

Cells of Mikania glomerata, Cephaelis ipecacuanha and Maytenus aquifolia were co-cultured in a two-phase system using filter paper as a solid support. The species were co-cultured in all possible paired combinations. Interaction between Mikania and Maytenus cells resulted in increased biomass production of Maytenus cells, but the friedelin content was reduced. Co-cultivation of Cephaelis and Mikania cells enhanced coumarin content, but inhibited the growth of Mikania cells. However, yield of emetine as well as Cephaelis biomass accumulation were positively stimulated by the co-cultivation. Results indicate a possible occurrence of allelopathy in such a system.

Coupling Surface-Enhanced Resonance Raman Scattering and Electronic Tongue as Characterization Tools to Investigate Biological Membrane Mimetic Systems

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

Up-converter nanophosphor Y2O2S:Er,Yb aminofunctionalized containing or not spherical silica conjugated with BSA

This work reports on the study of the nanophosphor. Y2O2S:Er(2%),Yb(1%) obtained from polymeric resin to be evaluated as fluorescent label with Suitable features to conjugate with bio-molecules for bioassay up-converting phosphor technology (UPT) application A conjugation protocol between bovine serum albumin (BSA) and the aminofunctionalized nanophosphor containing or not spherical silica was established UV-vis results indicated an effective conjugation between nanophosphor particles and the protein up-conversion measurements under 980 nm excitation performed for samples before and after aminofunctionalization showed that nanophosphor particles luminescence features keep unchanged in all cases All results suggest that the adapted protocol is feasible to provide a nanoparticle-protein effective conjugation preserving nanophosphor optical features The presence of spherical silica can be considered advantageous to increase conjugation efficiency Therefore. the developed procedure is applicable for future conjugations between the chosen nanophosphor and the streptavidin protein chat takes part in the well known self-recognition system avidin-biotin. (C) 2009 Elsevier B.V All rights reserved.

Análise energética de sistemas de produção de etanol de mandioca (Manihot esculenta Crantz)

This work aimed to analyze the energetic consumption of the etanol production system, using the cassava as carbohidrates source. The researches were carried out from the field in the mid region of Paranapanema river, São Paulo state, during the period January to December, 2007. The energy consumption referring to the phases of crop production and industrial processing were appraised. It was verified that the total energetic cost of the crop production corresponded to 9,528.33 MJ ha(-1), and the most onerous item was the inputs (35.72%). In the industrial step, the energetic consumption was equivalent to 2,208.28 MJ t(-1). The operations of hydrolysis/saccharification/treatment of the juice represented 56.72% of the total energetic expenditure. The cassava crop presented an energetic cost of 1.54 MJ L-1 in relation to the etanol produced in the main agronomic operations crop production, and 11.76 MJ L-1 in the industrial processing. The energy efficiency observed in the cultivation and industrialization of the cassava was of 1.76.

A contribution for thermoeconomic modelling: A methodology proposal

This work presents a thermoeconomic optimization methodology for the analysis and design of energy systems. This methodology involves economic aspects related to the exergy conception, in order to develop a tool to assist the equipment selection, operation mode choice as well as to optimize the thermal plants design. It also presents the concepts related to exergy in a general scope and in thermoeconomics which combines the thermal sciences principles (thermodynamics, heat transfer, and fluid mechanics) and the economic engineering in order to rationalize energy systems investment decisions, development and operation. Even in this paper, it develops a thermoeconomic methodology through the use of a simple mathematical model, involving thermodynamics parameters and costs evaluation, also defining the objective function as the exergetic production cost. The optimization problem evaluation is developed for two energy systems. First is applied to a steam compression refrigeration system and then to a cogeneration system using backpressure steam turbine. (C) 2010 Elsevier Ltd. All rights reserved.

Metodologia para rastreamento com modificação dos zeros e rejeição de distúrbio aplicada a sistemas incertos

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

Manejo de água em arroz de terras altas no sitema de plantio direto, usando o tanque classe A

O presente trabalho teve como objetivo estudar o efeito do manejo de água em cultivares de arroz de terras altas no sistema de plantio direto, usando o tanque Classe A. Os tratamentos consistiram na combinação de três manejos (sequeiro e duas lâminas) e duas cultivares (Confiança e Maravilha), com quatro repetições. A irrigação proporcionou aumento na altura de plantas, massa de 100 grãos, massa hectolítrica, produtividade de grãos, rendimento de benefício e redução do número de dias para o florescimento e ciclo total da cultura. Os valores adotados de coeficientes de cultura não influenciam nas características fenológicas e produtivas da cultura. A produtividade de grãos não diferiu entre as cultivares Confiança e Maravilha.

Desempenho perceptual-auditivo e ortográfico de consoantes fricativas na aquisição da escrita

OBJETIVO: Verificar os desempenhos perceptual-auditivo e ortográfico de escolares no que se refere à identificação de contrastes entre as fricativas do Português Brasileiro, e investigar em que medida esses dois tipos de desempenhos se relacionam. MÉTODOS: Foram analisados dados de desempenho perceptual-auditivo e de desempenho ortográfico extraídos de 20 crianças das duas primeiras séries do ensino fundamental de uma escola pública do município de Mallet (PR). A coleta de dados de percepção auditiva foi feita com base no Instrumento de Avaliação da Percepção de Fala (PERCEFAL), com o uso do software Perceval. Já a coleta de dados de ortografia foi feita por meio de um ditado das mesmas palavras que compõem o instrumento PERCEFAL. RESULTADOS: Foram observadas: maior acurácia perceptual-auditiva do que ortográfica; tendência de menor tempo de resposta e de menor variabilidade nos acertos perceptuais-auditivos do que nos erros; não correspondência de erros de percepção-auditiva e ortografia, já que, na percepção, o maior percentual de erros envolveu o ponto de articulação das fricativas, enquanto que, na ortografia, o maior percentual envolveu o vozeamento. CONCLUSÃO: Embora se mostrem relacionados, os desempenhos perceptual-auditivo e ortográfico não apresentam correspondência termo a termo. Portanto, na prática clínica, a atenção deve-se voltar não apenas para os aspectos que aproximam esses dois desempenhos, mas, também, para os aspectos que os diferenciam.