Mechanochemical Synthesis of Double Hydroxides Tập 8 - Trang 251-253 - 2000
V. P. Isupov, L. E. Chupakhina, R. P. Mitrofanova
It has been demonstrated that the formation of magnesium-aluminium double
hydroxides [Mg(1 − X)Al X (OH)2] X+(A n− X/n ) • m H2O, (A–Cl−, NO− 3, SO2− 4)
occurs during mechanical activation of the mixture of magnesium hydroxide
(brucite) with aluminium chloride, nitrate and sulphate in high-energy
planetary-type activators. The effect of activation time on the formation of the
double hydroxide has ... hiện toàn bộ
MSR Reduction of Hexachlorobenzene Tập 8 - Trang 295-300 - 2000
M. Monagheddu, S. Doppiu, G. Cocco
This paper deals with the mechanochemical degradation of hexachlorobenzene over
Li, Na, K, Mg, Ca, Ba, Ti, and W. Apart from the mixtures containing Ti and W,
the other systems react in a combustive mode leading to the chlorides and the
carbides of the inorganic substrates. Reaction stoichiometries and heats were
experimentally determined. The activation time required to ignite the reaction
decrea... hiện toàn bộ
Combustion Synthesis of Glass (B2O3-Al2O3-MgO)-Ceramic (TiB2) Composites Tập 10 - Trang 163-174 - 2002
H. C. Yi, J. Y. Guigne, J. J. Moore, A. R. Manerbino, L. A. Robinson, F. D. Schowengerdt
The combustion synthesis, or self-propagating high temperature synthesis (SHS),
technique has been used to produce glass ceramic composites that have a glass
matrix based on B2O3-MgO-Al2O3and a crystalline ceramic phase of TiB2.
Conditions for producing glassy materials by the SHS technique are discussed and
the thermodynamics of these combustion reactions are analyzed. The combustion
characterist... hiện toàn bộ
Reaction Bonding of Three-Layer Alumina-Based Composites Tập 7 - Trang 195-203 - 1999
Jihong She, Sven Scheppokat, Rolf Janssen, Nils Claussen
Three-layer alumina-based composites with Al2O3-containing mullite as the outer
layer and ZrO2-containing alumina as the inner layer were fabricated by
die-pressing and reaction bonding. The effects of the outer-layer compositions
on the densification behavior of three-layer composites were investigated. The
existence of residual stresses in the layers was verified using indentation
methods. Compa... hiện toàn bộ
Computer Modeling of the Evolution of Dendrite Microstructure in Binary Alloys During Non-isothermal Solidification Tập 10 - Trang 191-203 - 2002
M. Grujicic, G. Cao, R. S. Miller
Two-dimensional simulations of the evolution of dendrite microstructure during
isothermal and non-isothermal solidifications of a Ni-0.41Cu binary alloy are
carried out using the phase-field method. The governing evolution equation for
the phase field variable, the solute mole fraction and the temperature are
formulated and numerically solved using an explicit finite difference scheme. To
make the... hiện toàn bộ
Chemical Durability of Waste Fluorescent Glass and Shell–Derived Glass-Ceramics Tập 10 - Trang 37-42 - 2002
Y.-H. Yun, S.-B. Kim, B.-A. Kang, J.-S. Oh, K.-S. Hwang
In order to obtain glass-ceramics reinforced by β-wollastonite, pressed
specimens prepared by powdered waste fluorescent glass and refuse shell dumped
in the seashore were heat-treated at 800°C, 900°C, and 1000°C. Chemical
stability of the heat-treated specimens was analyzed by weight changes and by
observation of surface morphology and composition, by field-emission scanning
electron microscopy a... hiện toàn bộ
Synthesis and Properties of Willemite, Zn2SiO4, and M2+:Zn2SiO4 (M = Co and Ni) Tập 7 - Trang 273-279 - 1999
G. T. Chandrappa, S. Ghosh, K. C. Patil
Fine particles of willemite, α-Zn2SiO4, were prepared by both solution
combustion and sol-gel methods. Both processes yield single-phase, large-surface
area (26- and 78-m2/g), sinteractive willemite powders. Thermal evolution of
crystalline phases was studied using X-ray powder diffraction patterns. The
combustion method favors low-temperature formation of willemite compared to the
sol-gel method.... hiện toàn bộ
Stabilization of New Phases in Ion-Conducting Nanocomposites Tập 8 - Trang 319-326 - 2000
N. F. Uvarov, P. Vaněk
Physical properies of ion-conducting nanocomposites are reviewed. Special
attention is paid to the change of the bulk characteristics of ionic salts in
the nanocomposites due to the formation of the interface phases. The main
thermodynamic reason of the formation of the nanocomposite as well as the
stabilization of the interface phases is the adhesion energy σa. At sufficiently
high σa values, the... hiện toàn bộ
Work Function of PbZrO3 Tập 6 - Trang 335-338 - 1998
S. Sugihara, T. Bak, J. Nowotny, M. Radecka, C. C. Sorrell
This paper reports the results of work function (WF) changes of undoped PbZrO3
during subsequent isothermal oxidation and reduction experiments at 500°C in the
p(O2) range between 10 and 2.1 × 104 Pa. The results, obtained during three
consecutive runs, indicate that heating at 500°C leads to continuous changes of
surface properties resulting in a complex WF vs. time characteristic. The WF
changes... hiện toàn bộ