Z. Ren、Robert A. Shanks、Trevor J. Rook2001-01-01Journal of Applied Polymer Science
Polypropylene (PP) composites with high filler content have been prepared with surface-treated fillers. The effect of the filler is twofold; nucleation of crystallization occurs, though the PP is also adsorbed onto the filler thereby retarding its motion. Differential scanning calorimetry has been used to study the cr…
biodegradable polymer synthesis and propertiesPolymer Nanocomposites and PropertiesPolymer crystallization and properties
Silva A. Ferreira da、Silva T. Souza da、Nakamura O. 等 7 位作者2001-01-01Materials Research
Thermal diffusivity and optical absorption have been investigated for porous silicon, at room temperature, using photoacoustic spectroscopy. The experimental results obtained conform well with the existing studies recently published. The value obtained for thermal diffusivity is 0.045 ± 0.002 cm²/s.The absorption onse…
A.O. dos Santos、R.V. Gelamo、B.B. Li 等 11 位作者2001-01-01Materials Research
In this work, the application of the X-ray multiple diffraction technique using synchrotron radiation at Laboratório Nacional de Luz Síncrotron (LNLS) to study KDP phase transition induced by electric field is discussed. A Huber three-axis (omega, phi, 2theta) diffractometer mounted on a table which rotates around the…
Maria Teresa Paulino Aguilar、Elaine Carballo Siqueira Corrêa、Waldemar Alfredo Monteiro 等 5 位作者2001-01-01Materials Research
The work hardening of metals subjected to complex processing paths is different from that in monotonic deformation. Changes in the deformation mode can promote transients in the strain-hardening rate, leading to anomalous softening or hardening of the material. This paper investigates the influence of strain path chan…
Lenza R.F.S.、Vasconcelos W.L.2001-01-01Materials Research
In this work we investigated the influence of formamide on the acid-catalyzed sol-gel process by Fourier transform infrared spectroscopy (FTIR). Three silica sols were studied: Sol catalyzed with nitric acid without formamide, sol catalyzed with nitric acid containing formamide and sol catalyzed with a mixture of nitr…
Jen-Shih Chang2001-01-01Science and Technology of Advanced Materials
Gaseous pollution control, solid and liquid waste treatments have been commercialized based on incineration, catalysis, adsorption, disposal with landfill, etc. More recently technology based on plasmas has become significant due to the advantages such as lower costs, higher treatment and energy efficiencies, smaller…
Bojan A. Marinković、Roberto Ribeiro de Avillez、A. Saavedra 等 4 位作者2001-01-01Materials Research
The fundamental parameters approach is used to simulate the instrument contribution to the X-Ray diffraction profile. This procedure eliminates the need to experimentally prepare a reference sample of the studied crystalline material when using the Warren-Averbach method to investigate microstrutural parameters. The W…
X-ray Diffraction in CrystallographyAdvanced ceramic materials synthesisMicrostructure and Mechanical Properties of Steels
Wang S.H.、Zawadzki S.、Akcelrud L.2001-01-01Materials Research
A series of polyurethane/PMMA simultaneous interpenetrating networks (SINs) with various hard segment contents (X) in the polyurethane phase (X = 15.5 to 36.5% in polyurethane) and wide range of polyurethane (PU) to polyacrylate (PA) ratio (PU/PA = 20:80 to 80:20) were prepared, and the damping and mechanical properti…
Yuichi Ikuhara, Takahisa Yamamoto, Akihide Kuwabara, Hidehiro Yoshida and Taketo Sakuma2001-01-01Science and Technology of Advanced Materials
The addition of glass phase can control the grain boundary structure and hence the mechanical properties of tetragonal zirconia polycrystals (TZP). To reveal the effect of the glass dopant on the high-temperature deformation behavior of TZP, SiO2-doped TZP, (SiO2–Al2O3)-doped TZP, (SiO2–MgO)-doped TZP and undoped TZP…
Guimarães V.A.、Hein L.R.O.、Zangrandi Filho J.2001-01-01Materials Research
Fracture toughness testing becomes a very important parameter for mechanical design and maintenance of parts and structures. This work presents the design and construction of a machine device to perform the pre-crack nucleation on SE(B) specimens for fracture toughness testing. Employing this device, it is possible to…
Célia Marisa Rizzatti-Barbosa、Marco Aurélio Fraga、Tarcísio de Moraes Gonçalves2001-01-01Materials Research
The purpose of this work was to analyze water sorption by polymerized acrylic resins under different pressure, temperature and time treatments. A thermo-cured acrylic resin was used as the denture base (Classico Ltda.) and ethylene glycol di-methacrylate as a cross-linking agent, with processing carried out in a water…
Marcello Filgueira、José Nilson F. de Holanda、Ruben Rosenthal 等 4 位作者2001-01-01Materials Research
Cu-Nb microcomposites are attractive in magnet pulsed field technology applications due to their anomalous mechanism of mechanical strength and high electrical conductivity. In this sense, recently it was conceived the use of Cu 15% vol. Nb wires to operate as a high tensile strength cable for a diamond cutting tool (…
Nassar Eduardo J.、Serra Osvaldo A.、Calefi Paulo S. 等 5 位作者2001-01-01Materials Research
Silica gel was functionalised with chloropropyl groups through the sol-gel process and then a beta-diketone was incorporated into the support. Afterwards, Eu3+ ion and its chelates of 1,10-phenantroline (phen) and 2,2'-bipyridine (bpy), red phosphors, were supported on such silica. Luminescence studies of Eu3+ bound t…
Machado Giovanna、Luca Maria Augusta de、Samios Dimitrios2001-01-01Materials Research
We evaluate the orientation of microstructural elements of isotatic polypropylene (i-PP) before and after deformation using computerized "Quantikov" software analysis of Scanning Electron Microscopy (SEM) images. We observed that before deformation through uniaxial compression, the polymeric material doesn?t exhibit a…
R.G. Mendes、E.B. Araújo、J.A. Eiras2001-01-01Materials Research
Strontium barium niobate (SBN) thin films of good quality were deposited on Pt/Ti/SiO2/Si substrate using a polymeric resin containing metallic ions. Films were crystallized at different temperatures and for different duration of time. The structure of these films was studied using X-ray diffraction. The coexistence o…
Maurício F. Gozzi、Eduardo Radovanovic、I. Valéria P. Yoshida2001-01-01Materials Research
Si3N4/SiC nanocomposite powders were obtained from a preceramic polymeric network based on poly(methylsilane) as the in situ quasi-stoichiometric SiC source. These powders were constituted of nanosized SiC particles homogeneously distributed in the Si3N4 particulate matrix. beta-SiC whiskers were grown at 1400 °C in t…
José A. da Rocha Filho、Erna E. Bach、Élcio R. Barrak 等 4 位作者2001-01-01Materials Research
Graft polymerization of N-vinyl-2-pyrrolidone with chitin was studied using hydrogen peroxide for initiation. The capacity of the obtained VP-g-Ch graft copolymer for adsorption of nickel was examined. The effect of temperature, pH and solute concentration on the chelating properties of the grafted and ungrafted chiti…
A.G. Tomba Martinez、A.L. Cavalieri2001-01-01Materials Research
Disks of a commercial alumina were fabricated by slip casting, calcination and sintering. The surfaces were machined using SiC papers (120 and 320 grit) and characterized by residual stresses measurements. The mechanical strength was determined in biaxial flexure (ball on discontinuous ring). The specimens were subjec…
Lourenço N.J.、Jorge Jr. A.M.、Rollo J.M.A. 等 4 位作者2001-01-01Materials Research
Dilatometric techniques were used to build the continuous cooling transformation (CCT) diagram for a medium carbon microalloyed steel; the microstructure and hardness were determined at different cooling rates. The mechanical behavior of the steel in the austenite field and at temperatures approaching austenite to fer…
Hiroaki Takadama, Hyun-Min Kim, Tadashi Kokubo and Takashi Nakamura2001-01-01Science and Technology of Advanced Materials
Bioactive Ti–6Al–4V alloy, which spontaneously forms a bonelike apatite layer on its surface in the body and bonds to living bone through this apatite layer, can be prepared by producing an amorphous sodium titanate on its surface by NaOH and heat treatments. In this study, the process of apatite formation on the bioa…