Conception of wheeled mobile robots with reconfigurable control using integrate prototyping

With the fast innovation of the hardware and software technologies using rapid prototyping devices, with application in the robotics and automation, more and more it becomes necessary the development of applications based on methodologies that facilitate future modifications, updates and enhancements in the original projected system. This paper presents a conception of mobile robots using rapid prototyping, distributing the several control actions in growing levels of complexity and using resources of reconfigurable computing proposal oriented to embed systems implementation. Software and the hardware are structuralized in independents blocks, with connection through common bus. The study and applications of new structures control that permits good performance in relation to the parameter variations. This kind of controller can be tested on different platform representing the wheeled mobile robots using reprogrammable logic components (FPGA). © 2006 IEEE.

Measuring the efficiency of outsourcing: An illustrative case study from the aerospace industry

Outsourcing is related to the action which an organization deals with its suppliers through a kind of business contract where a specific activity or service has been hired to be made. The outsourcing of some activities has become a common practice in the industry, nowadays. It reduces costs, significantly, in the production process and, at the same time, adds some values to the business organization. However it is necessary to measure the performance of these activities. Data Envelopment Analysis (DEA) is a non-parametric method useful to measure comparative performance. It has a wide range of applications measuring comparative efficiency. The Analytic Hierarchy Process (AHP) is a multiple criteria decision-making method that uses hierarchic structures to represent a decision problem and then develops priorities for the alternatives based on the decision-maker's judgments. This paper presents an integrated application based on DEA and AHP to evaluate the efficiency of subcontracted companies in a Brazilian aerospace factory. © 2007 Springer-Verlag London Limited.

Damping behavior of hygrothermally conditioned carbon fiber/epoxy laminates

Carbon fiber reinforced polymer composites have been used in wide variety of applications including, aerospace, marine, sporting equipment as well as in the defense sector due to their outstanding properties at low density. In many of their applications, moisture absorption takes place which may result in a reduction in mechanical properties even at lower temperature service. In this work, the viscoelastic properties, such as storage modulus (E′) and loss modulus (E″), were obtained through vibration damping tests for three carbon fiber/epoxy composite families up to the saturation point (6 weeks). Three carbon fiber/epoxy composites having [0/0] s, [0/90] s, and [±45] s orientations were studied. During vibration tests the storage modulus (E′) and loss modulus (E″) were monitored as a function of moisture uptake, and it was observed that the natural frequencies and E′ values decreased with the increase during hygrothermal conditioning due to the matrix plasticization. © 2007 Wiley Periodicals, Inc.

Simulation of computational grids scheduling politics

Computational grids allow users to share resources of distributed machines, even if those machines belong to different corporations. The scheduling of applications must be performed aiming at performance goals, and focusing on choose which processes can have access to specif resources, and which resources. In this article we discuss aspects of scheduling of application in grid computing environment. We also present a tool for scheduling simulation along with test scenarios and results.

Analysis of quality in Brazilian e-commerce (B2C)

The business world has changed the way how people think and act on products and services. In this context, the most recent amendment of the scenarios of retail operations has been the use of technology in sales and distribution. The internet has revolutionized the way people communicate, and moreover as they purchase their goods and services. Thus, the e-commerce, specifically the relation business to customer, or simply B2C, has acted so convincingly in this change of paradigm, namely the purchases in the physical location for the virtual site. Quotes online, ease of payment, price, speed of delivery, have become real order winners of applications for companies that compete in this segment. With the focus on quality of services on e-commerce, the research examines the dimension related to the quality of services, and looks for what of these factors are winners of applications. © 2010 IFIP International Federation for Information Processing.

Methodology analysis of a computational tool used in electronic circuit design

This paper considers the importance of using a top-down methodology and suitable CAD tools in the development of electronic circuits. The paper presents an evaluation of the methodology used in a computational tool created to support the synthesis of digital to analog converter models by translating between different tools used in a wide variety of applications. This tool is named MS 2SV and works directly with the following two commercial tools: MATLAB/Simulink and SystemVision. Model translation of an electronic circuit is achieved by translating a mixed-signal block diagram developed in Simulink into a lower level of abstraction in VHDL-AMS and the simulation project support structure in SystemVision. The method validation was performed by analyzing the power spectral of the signal obtained by the discrete Fourier transform of a digital to analog converter simulation model. © 2011 IEEE.

On the existence of ordered phases of encapsulated diamondoids into carbon nanotubes

We have investigated some diamondoids encapsulation into single walled carbon nanotubes (with diameters ranging from1.0 up to 2.2 nm) using fully atomistic molecular dynamics simulations. Diamondoids are the smallest hydrogen-terminated nanosized diamond-like molecules. Diamondois have been investigated for a large class of applications, ranging from oil industry to pharmaceuticals. Molecular ordered phases were observed for the encapsulation of adamantane, diamantane, and dihydroxy diamantanes. Chiral ordered phases, such as; double, triple, 4- and 5-stranded helices were also observed for those diamondoids. Our results also indicate that the modification of diamondoids through chemical functionalization with hydroxyl groups can lead to an enhancement of the molecular packing inside the carbon nanotubes in comparison to non-functionalized molecules. For larger diamondoids (such as, adamantane tetramers), we have not observed long-range ordering, but only a tendency of incomplete helical structural formation. © 2012 Materials Research Society.

Liquid foam templates associated with the sol-gel process for production of zirconia ceramic foams

The unique properties of ceramic foams enable their use in a variety of applications. This work investigated the effects of different parameters on the production of zirconia ceramic foam using the sol-gel process associated with liquid foam templates. Evaluation was made of the influence of the thermal treatment temperature on the porous and crystalline characteristics of foams manufactured using different amounts of sodium dodecylsulfate (SDS) surfactant. A maximum pore volume, with high porosity (94%) and a bimodal pore size distribution, was observed for the ceramic foam produced with 10% SDS. Macropores, with an average size of around 30 μm, were obtained irrespective of the SDS amount, while the average size of the supermesopores increased systematically as the SDS amount was increased up to 10%, after which it decreased. X-ray diffraction analyses showed that the sample treated at 500 °C was amorphous, while crystallization into a tetragonal metastable phase occurred at 600 °C due to the presence of sulfate groups in the zirconia structure. At 800 and 1000 °C the monoclinic phase was observed, which is thermodynamically stable at these temperatures. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

Improvements of plasma immersion ion implantation (PIII) and deposition (PIII&D) processing for materials surface modification

Plasma immersion ion implantation (PIII) process is a three dimensional surface modification method that is quite mature and well known to the surface engineering community nowadays, especially to those working in the field of plasma-materials interaction, aiming at both industrial and academic applications. More recently, deposition methods have been added to PIII, the PIII&D, opening possibilities of broader range of applications of these techniques. So, PIII&D is becoming a routine method of surface modification, with the advantage of pushing up the retained dose levels limited by the sputtering due to ion implantation. Therefore, well adherent, thick, three-dimensional films without stress are possible to be achieved, at relatively low cost, using PIII&D. In this paper, we will discuss about a few PIII and PIII&D experiments that have been performed recently to achieve surface improvements in different materials: 1 - high temperature nitrogen PIII in Ti6Al4V alloy in which a deep nitrogen rich treated layer resulted in surface improvements as increase of hardness, corrosion resistance and resistance to wear of the Ti alloy; 2 - nanostructures in ZnO films, obtained by PIII&D of vaporized & ionized Zn source; 3 - combined implantation and deposition of calcium for biomaterial activity of Ti alloy (PIII&D), allowing the growth of hydroxyapatite in a body solution; 4 - magnetron sputtering deposition of Cr that was enhanced by the glow discharge Ar plasma to allow implantation and deposition of Cr on SAE 1070 steel (PIII&D) resulting in surfaces with high resistance to corrosion; and 5 - implantation of nitrogen by ordinary PIII into this Cr film, which improved resistance to corrosion, while keeping the tribological properties as good as for the SAE 1070 steel surface. © 2012 Elsevier B.V.

Large-Area Plasmonic Substrate of Silver-Coated Iron Oxide Nanorod Arrays for Plasmon-Enhanced Spectroscopy

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

Monitoring of hydrogen sulfide via substrate-integrated hollow waveguide mid-infrared sensors in real-time

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Microwave-assisted hydrothermal synthesis of magnetite nanoparticles with potential use as anode in lithium ion batteries

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

Evaluation of modified silica nanoparticles in carboxylated nitrile rubber nanocomposites

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

Towards the development of fiber lasers for the 2 to 4 nanom spectral region

A growing number of applications are calling for compact laser sources operating in the mid-infrared spectral region. A review of our recent work on monolithic fiber lasers (FL) based either on the use of rare-earth fluoride fibers or on Raman gain in both fluoride and chalcogenide glass fibers is presented. Accordingly, an erbium-doped double clad fluoride glass all-FL operating in the vicinity of 3 μm is shown. In addition, we present recent results on the first demonstrations of both fluoride and chalcogenide Raman fiber lasers operating at 2.23 and 3.34 μm, respectively. It is shown that based on this approach, monolithic FLs could be developed to cover the whole 2 to 4 μm spectral band.

Nano-displacement measurements of a new piezoelectric flextensional actuator by using a high dynamic range interferometry homodyne method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)