Casting Technique (casting + technique)

Distribution by Scientific Domains


Selected Abstracts


Effect of NaCl filler on ferroelectric phase and polaron configurations of PVDF films

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2007
I. S. ElashmawiArticle first published online: 8 MAR 200
Abstract Polyvinyldene fluoride (PVDF) films filled with NaCl of mass fraction range 1 , W , 6 % were prepared by casting technique. Their crystalline structure, thermal, optical properties and Electron spin resonance (ESR) were examined. X-ray diffraction (XRD) and differential thermal analysis (DTA) measurements indicated a maximum ferroelectric ,-phase increment at 4%. DTA was used to identify the phase transition temperatures, the order of reaction and the activation energy of melting. The UV-Visible optical absorption implied a minimum value of the estimated optical energy gap at W = 4%. ESR spectra contained a Lorentizian signal exhibiting a minimum value of the symmetry factor at W = 4%. The energy levels of the optical gap boundaries were though to contribute to ESR transitions. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Optimization of Mechanical Properties of NiAl-base Alloy by Suction Casting,

ADVANCED ENGINEERING MATERIALS, Issue 4 2006
W. Huai
The suction-cast NiAl-Cr(Mo)/Hf alloy exhibits a refined microstructure and extended solid solubility. Significant improvement in room temperature ductility and strength was achieved by adopting suction casting technique. In addition, their elevated temperature strength also got slightly increase. The optimized mechanical properties can be attributed to the fine interlamellar spacing, the extended solid solubility and the increased cell eutectic zone as well as the refined Heusler phase. [source]


From Micro to Meso: an exercise in determining hydraulic conductivity of fractured sandstone cores from detailed characterization of the fractures

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2006
Salima Baraka-Lokmane
SUMMARY Hydraulic conductivities of fractured sandstone bore cores of 0.1 m in diameter are calculated using detailed characterization of the fracture geometry parameters determined using a resin casting technique. The accuracy of the measurements was about 0.25,1.25 ,m with the image size used. The values of the effective fracture apertures vary between 10 ,m and 50 ,m. For modelling purposes the samples are sectioned serially, perpendicular to the flow direction along the cylinder axis. The hydraulic conductivity of individual slices is estimated by summing the contribution of the matrix (assumed uniform) and each fracture (depending on its length and aperture). Finally, the hydraulic conductivity of the bulk sample is estimated by a harmonic average in series along the flow path. Results of this geometrical upscaling compare favourably with actual conductivity measured in hydraulic and pneumatic experiments carried out prior to sectioning. This study shows that the determination of larger-scale conductivity can be achieved, based on the evaluation of fracture geometry parameters (e.g. fracture aperture, fracture width and fracture length), measured using an optical method, at least at the laboratory scale. [source]


Reversible Luminescent Switching in a [Eu(SiW10MoO39)2]13, -Agarose Composite Film by Photosensitive Intramolecular Energy Transfer

ADVANCED MATERIALS, Issue 17 2009
Zhongliang Wang
Transparent, flexible, self-supporting EuSiWMo/agarose composite films are fabricated by a combination of hydrogel chemistry and a casting technique, and present reversible, high-contrast luminescence photoswitching modulated by inorganic photochromic components through intramolecular resonance-energy transfer. Two-dimensional recording employing the luminescence as read-out signals is accomplished in this novel recording medium. [source]


Antibacterial polyvinyl chloride/antibiotic films: The effect of solvent on morphology, antibacterial activity, and release kinetics

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010
Martha Merchan
Abstract Medical-grade polyvinyl chloride was modified with sodium ampicillin in a concentration range from 0 to 5 wt % by solvent casting technique using cyclohexanone and N,N -dimethylformamide. The obtained polymeric systems were characterized by optical microscopy, tensile test, and scanning electron microscopy. In addition, in vitro antibacterial activity against Gram-negative and Gram-positive bacteria was determined by an agar diffusion test. Antibiotic release experiments were performed in distilled water and physiological saline solution, which were monitored by UV-vis spectroscopy. The results showed a crucial role of the solvent on the morphology, antibacterial activity, and releasing characteristic of the ampicillin. Furthermore, a mathematical model was applied to data obtained from release study, to characterize the release kinetics of the ampicillin from the polyvinyl chloride-antibiotic systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


Calcium-phosphate surface coating by casting to improve bioactivity of titanium

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 5 2001
Taiji Sohmura
Abstract In order to improve the bioactivity of titanium, an original surface treatment was attempted with the use of a casting technique was attempted. Pure titanium was cast into a special graphite mold in which the cavity wall was coated with hydroxyapatite (HA) powder. According to analyses of X-ray diffraction and EDX, the existence of HA and CaO and uptake of Ca and P on the surface of the titanium castings were identified. By immersing the specimen in Hank's solution, the concentrations of Ca and P on the surface increased with immersion time, and the formation of a thin layer with characteristics of spherical HA precipitates was observed after 1 week. The concentrations of Ca and P elements and the Ca/P ratio on the HA layer increased with immersion time. The formation of the HA layer on the titanium cast by this treatment was significantly accelerated compared with pure titanium. The present surface treatment of Ti is expected to improve early bone fixation of Ti implants. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 478,485, 2001 [source]


Thin Yttrium-Stabilized Zirconia Electrolyte Solid Oxide Fuel Cells by Centrifugal Casting

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2002
Jiang Liu
A centrifugal casting technique was developed for depositing thin 8-mol%-yttrium-stabilized zirconia (YSZ) electrolyte layers on porous NiO-YSZ anode substrates. After the bilayers were cosintered at 1400°C, dense pinhole-free YSZ coatings with thicknesses of ,25 ,m were obtained, while the Ni-YSZ retained porosity. After La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)-Ce0.9Gd0.1O1.95 (GDC) or La0.8Sr0.2MnO3 (LSM)-YSZ cathodes were deposited, single SOFCs produced near-theoretical open-circuit voltages and power densities of ,1 W/cm2 at 800°C. Impedance spectra measured during cell tests showed that polarization resistances accounted for ,70%,80% of the total cell resistance. [source]