Polymer Matrix-Based Piezoelectric Composite for Structural Health Monitoring

Structural health monitoring (SHM) refers to the procedure of assessing the structure conditions continuously so it is an alternative to conventional nondestructive evaluation (NDE) techniques [1]. With the growing developments in sensor technology acoustic emission (AE) technology has been attracting attention in SHM applications. AE are characterized by waves produced by the sudden internal stress redistribution caused by the changes in the internal structure, such as fatigue, crack growth, corrosion, etc. Piezoelectric materials such as Lead Zirconate Titanate (PZT) ceramic have been widely used as sensor due to its high electromechanical coupling factor and piezoelectric d coefficients. Because of the poor mechanical characteristic and the lack in the formability of the ceramic, polymer matrix-based piezoelectric composites have been studied in the last decade in order to obtain better properties in comparison with a single phase material. In this study a composite film made of polyurethane (PU) and PZT ceramic particles partially recovered with polyaniline (PAni) was characterized and used as sensor for AE detection. Preliminary results indicate that the presence of a semiconductor polymer (PAni) recovering the ceramic particles, make the poling process easier and less time consuming. Also, it is possible to observe that there is a great potential to use such type of composite as sensor for structure health monitoring.

Structure of the polypeptide crotamine from the Brazilian rattlesnake Crotalus durissus terrificus

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

Glycosomal Targets for Anti-Trypanosomatid Drug Discovery

Glycosomes are peroxisome-related organelles found in all kinetoplastid protists, including the human pathogenic species of the family Trypanosomatidae: Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. Glycosomes are unique in containing the majority of the glycolytic/gluconeogenic enzymes, but they also possess enzymes of several other important catabolic and anabolic pathways. The different metabolic processes are connected by shared co-factors and some metabolic intermediates, and their relative importance differs between the parasites or their distinct life-cycle stages, dependent on the environmental conditions encountered. By genetic or chemical means, a variety of glycosomal enzymes participating in different processes have been validated as drug targets. For several of these enzymes, as well as others that are likely crucial for proliferation, viability or virulence of the parasites, inhibitors have been obtained by different approaches such as compound libraries screening or design and synthesis. The efficacy and selectivity of some initially obtained inhibitors of parasite enzymes were further optimized by structure-activity relationship analysis, using available protein crystal structures. Several of the inhibitors cause growth inhibition of the clinically relevant stages of one or more parasitic trypanosomatid species and in some cases exert therapeutic effects in infected animals. The integrity of glycosomes and proper compartmentalization of at least several matrix enzymes is also crucial for the viability of the parasites. Therefore, proteins involved in the assembly of the organelles and transmembrane passage of substrates and products of glycosomal metabolism offer also promise as drug targets. Natural products with trypanocidal activity by affecting glycosomal integrity have been reported.

Robust Switched Control Design for Nonlinear Systems Using Fuzzy Models

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

Bone Morphogenetic Proteins: Structure, biological function and therapeutic applications

Bone Morphogenetic Proteins (BMPs) are multifunctional secreted cytokines, which belong to the TGF-beta superfamily. These glycoproteins act as a disulfide-linked homo- or heterodimers, being potent regulators of bone and cartilage formation and repair, cell proliferation during embryonic development and bone homeostasis in the adult. BMPs are promising molecules for tissue engineering and bone therapy. The present review discusses this family of proteins, their structure and biological function, their therapeutic applications and drawbacks, their effects on mesenchymal stem cells differentiation, and the cell signaling pathways involved in this process. (C) 2014 Published by Elsevier Inc.

Molecular design of new P3HT derivatives: Adjusting electronic energy levels for blends with PCBM

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

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/).

Optimized design of substrate-integrated hollow waveguides for mid-infrared gas analyzers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

On Switched Regulator Design of Uncertain Nonlinear Systems Using Takagi-Sugeno Fuzzy Models

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

Estudo de causas de falhas em selos mecânicos de bombas centrífugas para circulação de óleo térmico

This study is about a heating line that uses thermal oil. It is located in a facility that produces interlayers used in cars windshields. A plastic resin is melted and is sent to a matrix called DIE where the interlayers are produced. The DIE needs to receive heat from the circulation of thermal oil in four different regions of its interior, to ensure the correct thickness of the interlayer. The thermal energy is provided by electric heaters and the flow of thermal oil is impelled by four mechanically sealed centrifugal pumps (one per region). The key point of this study is the fact that these four pumps of the system have reported successive failures in the mechanical seals. Apparently, a poorly designed project has burdened the system intermittently. The pumps operation condition is located in a region of low efficiency, according to the characteristic curves. This fact is the source of the noticeable reduced time between failures. Changes in the configuration of the facility and in the number of pumps will be proposed, aiming to achieve higher operational efficiency. The proposals will be mathematically analyzed according to the Hydraulic Institute criteria. At the same time, we will also keep focus on an in-depth study of a heating system structure, starting with a detailed approach for each component and discussion about its real need and economic viability. At the end of this paper it is shown that the gain in efficiency achieved with the new proposed configuration reflects not only in the reduction of maintenance costs, but also a potential improvement in energy efficiency. It is shown that these two aspects are closely related and together form the basis for the design of a reliable and efficient pumping system

Alterations in extracellular matrix composition in the aging larynx

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

Patch size, functional isolation, visibility and matrix permeability influences neotropical primate occurrence within highly fragmented landscapes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Unravelling the reaction mechanism of matrix metalloproteinase 3 using QM/MM calculations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Design and implementation of wireless sensor networks for impedance-based structural health monitoring using ZigBee and Global System for Mobile Communications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Active modal damping control of a smart truss structure using a self-organizing fuzzy controller

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