Macrokinetics of structural transformation during the gasless combustion of a titanium and carbon powder mixture

1990 ◽  
Vol 26 (1) ◽  
pp. 92-102 ◽  
Author(s):  
A. G. Merzhanov ◽  
A. S. Rogachev ◽  
A. S. Mukas'yan ◽  
B. M. Khusid
Keyword(s):  
Structural Transformation ◽  
Powder Mixture ◽  
Gasless Combustion ◽  
Carbon Powder

Structural transformations of powder mixture components in a gasless combustion wave

1989 ◽  
Vol 25 (6) ◽  
pp. 718-723 ◽  
Author(s):  
A. I. Kirdyashkin ◽  
O. K. Lepakova ◽  
Yu. M. Maksimov ◽  
A. T. Pak
Keyword(s):  
Combustion Wave ◽  
Powder Mixture ◽  
Structural Transformations ◽  
Gasless Combustion

Formation of Cubic Carbon by Dynamic Shock Compression of a Diamond/Amorphous Carbon Powder Mixture

1994 ◽  
Vol 33 (Part 1, No. 10) ◽  
pp. 5875-5885 ◽  
Author(s):  
Günther Burkhard ◽  
Koji Dan ◽  
Yasuhiro Tanabe ◽  
Akira B. Sawaoka ◽  
Kenjiro Yamada
Keyword(s):  
Shock Compression ◽  
Amorphous Carbon ◽  
Powder Mixture ◽  
Carbon Powder

scholarly journals Peculiarities in mechano-composite structural state based on aluminum for gas detonation sputtering

2017 ◽  
Vol 2 (12) ◽  
pp. 20-25 ◽  
Author(s):  
Александр Ситников ◽  
Alexandr Sitnikov ◽  
Алексей Собачкин ◽  
Aleksey Sobachki ◽  
Владимир Яковлев ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Mechanical Activation ◽  
Powder Mixture ◽  
Composite Powder ◽  
Amorphous State ◽  
Structure Characteristic ◽  
Carbon Powder ◽  
Gas Detonation ◽  
X Ray ◽  
Composite Mixture

Structural peculiarities of a powder composite mixture on the basis of aluminum and dispersion carbon structures intended for gas-detonation sputtering for an anti-friction purpose are investigated in the paper. As initial materials there was used an aluminum powder, carbon powder, boron carbide powder, powder slurry consisting of fullerenes C60 and ultra-dispersion diamonds in a certain ratio. The powder mixture obtained was subjected to a mechanical activation with the aid of a planetary ball mill of AGO-2S type. According to the results of the morphological analysis it was established that a composite mixture possesses a layer structure characteristic for powder mixtures subjected to a mechanical activation in the course of a long period of time. A mean size of obtained mechano-composite particles makes about 100…150 mkm. An X-ray structural investigation of a composite powder mixture formulations 70% Al+30%C+B4C and 70%Al + 30%C60 (total %) + B4C after mechanical activation revealed that boron carbide contributes well to the amorphization of a composite powder mixture. It is also established that after mechano-activation of the “Al+C+B4C” powder mixture during 4 min carbon transforms to an X-ray amorphous state to which testifies the presence of amorphous “halo” at small angles and carbon peaks disappeared completely. There is no carbon dissolution in aluminum and chemical compounds are not formed.

scholarly journals Densification and Microstructural Evolutions during Reaction Sintering of SiC-Si-C Powder Compacts

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
H. Asgharzadeh ◽  
N. Ehsani
Keyword(s):  
Powder Mixture ◽  
Coming Out ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Carbon Powder ◽  
Reaction Sintering ◽  
Ceramic Specimen ◽  
Powder Compacts ◽  
Porous Sic ◽  
Sic Particle

Porous SiC-Si-C ceramics were produced by reaction sintering (RS) of silicon carbide, silicon, and carbon powder compacts in the temperature range of 1400–1600°C. The effects of chemical composition of the starting powder, initial SiC particle size, and reaction sintering temperature and duration on the densification and microstructure of ceramic materials were studied. The results showed that increasing the amount of Si and/or C powders in the starting powder mixture had a detrimental influence on the densification of ceramic material as a result of higher amount of remained silicon and carbon phases in the ceramic specimen. Increasing the RS temperature also degraded densification due to the melting of Si and coming out of it from compact during heating. Nevertheless, densification was improved by increasing the RS duration. Using nanometric SiC particles in the starting powder mixture improved the densification compared to that of micrometric ones especially at longer RS processing duration.

High meta-stability of tungsten sub-carbide W2C formed from tungsten/carbon powder mixture during eruptive heating in a solar furnace

2007 ◽  
Vol 25 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Fernando Almeida Costa Oliveira ◽  
Jorge Cruz Fernandes ◽  
Jean-Marie Badie ◽  
Bernard Granier ◽  
Luis Guerra Rosa ◽  
...  
Keyword(s):  
Powder Mixture ◽  
Solar Furnace ◽  
Carbon Powder

scholarly journals Nitrogen Adsorption on Graphene Sponges Synthesized by Annealing a Mixture of Nickel and Carbon Powders

2017 ◽  
Vol 54 (4) ◽  
pp. 36-48
Author(s):  
V. Grehov ◽  
J. Kalnacs ◽  
A. Mishnev ◽  
K. Kundzins
Keyword(s):  
Specific Surface ◽  
Powder Mixture ◽  
Pressure Range ◽  
Nitrogen Adsorption ◽  
Inert Atmosphere ◽  
Carbon Powder ◽  
Relative Pressure ◽  
Graphene Sponge ◽  
Pressure Region ◽  
Effect Method

AbstractAdsorption by graphene sponge (GS) manufactured by annealing nickel-carbon powder mixture in inert atmosphere has been studied. By determining the specific surface area (SSA) for the GS sample, it has been found that Brunauer, Emmett, Teller method (BET) of approximation of experimental isotherms gives wrong results in the pressure range of 0.025–0.12 because adsorption in this pressure region is affected by walls of ampoule. Real SSA value has been found by subtracting pore effect method (SPE) or by BET approximation in a low range of relative pressure of 0.0004–0.002.

The structure of pre-mRNA and mRNA from erythroid cells

1978 ◽  
Vol 36 (2) ◽  
pp. 234-235
Author(s):  
A.-M. Ladhoff ◽  
B.J. Thiele ◽  
Ch. Coutelle ◽  
S. Rosenthal
Keyword(s):  
Bone Marrow ◽  
Structural Transformation ◽  
Electron Micrographs ◽  
Ammonium Acetate ◽  
Bone Marrow Cells ◽  
Erythroid Cells ◽  
Globin Mrna ◽  
Ordered Structures ◽  
Rabbit Bone ◽  
Rabbit Reticulocytes

The suggested precursor-product relationship between the nuclear pre-mRNA and the cytoplasmic mRNA has created increased interest also in the structure of these RNA species. Previously we have been published electron micrographs of individual pre-mRNA molecules from erythroid cells. An intersting observation was the appearance of a contour, probably corresponding to higher ordered structures, on one end of 10 % of the pre-mRNA molecules from erythroid rabbit bone marrow cells (Fig. 1A). A virtual similar contour was observed in molecules of 9S globin mRNA from rabbit reticulocytes (Fig. 1B). A structural transformation in a linear contour occurs if the RNA is heated for 10 min to 90°C in the presence of 80 % formamide. This structural transformation is reversible when the denatured RNA is precipitated and redissolved in 0.2 M ammonium acetate.

Structural Transformation of a Germanium Σ=13 (510) [001] Tilt Grain Boundary under the Electron Beam

1990 ◽  
Vol 48 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Jean-Luc Rouvière ◽  
Alain Bourret
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Mirror Symmetry ◽  
High Resolution Electron Microscopy ◽  
Structural Transformations ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Tilt Grain Boundary

The possible structural transformations during the sample preparations and the sample observations are important issues in electron microscopy. Several publications of High Resolution Electron Microscopy (HREM) have reported that structural transformations and evaporation of the thin parts of a specimen could happen in the microscope. Diffusion and preferential etchings could also occur during the sample preparation.Here we report a structural transformation of a germanium Σ=13 (510) [001] tilt grain boundary that occurred in a medium-voltage electron microscopy (JEOL 400KV).Among the different (001) tilt grain boundaries whose atomic structures were entirely determined by High Resolution Electron Microscopy (Σ = 5(310), Σ = 13 (320), Σ = 13 (510), Σ = 65 (1130), Σ = 25 (710) and Σ = 41 (910), the Σ = 13 (510) interface is the most interesting. It exhibits two kinds of structures. One of them, the M-structure, has tetracoordinated covalent bonds and is periodic (fig. 1). The other, the U-structure, is also tetracoordinated but is not strictly periodic (fig. 2). It is composed of a periodically repeated constant part that separates variable cores where some atoms can have several stable positions. The M-structure has a mirror glide symmetry. At Scherzer defocus, its HREM images have characteristic groups of three big white dots that are distributed on alternatively facing right and left arcs (fig. 1). The (001) projection of the U-structure has an apparent mirror symmetry, the portions of good coincidence zones (“perfect crystal structure”) regularly separate the variable cores regions (fig. 2).

CARBON POWDER MAGNETIZATION THERMOMETRY FOR VERY LOW TEMPERATURES

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-1164-C6-1165
Author(s):  
C. M. Bastuscheck ◽  
R. A. Buhrman ◽  
B. K. Sarma ◽  
D. B. Mast ◽  
J. B. Ketterson ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Carbon Powder
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