Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where A.G. Dhere is active.

Publication


Featured researches published by A.G. Dhere.


Materials Science and Engineering | 1982

Correlation between texture and substructure of conventionally and shock-wave-deformed aluminum

A.G. Dhere; H.-J. Kestenbach; Marc A. Meyers

Abstract The changes in texture and substructure induced in commercial purity aluminum by conventional (cross-rolling) and shock wave deformation (peak pressure, 5.8 GPa; pulse duration, 2.8 μs) were studied by X-ray diffraction and transmission electron microscopy. Three different grain sizes were investigated (26, 70 and 440 μm) and shock wave deformation did not produce any noticeable change in texture, while cold rolling induced significant changes. The deformation substructure consisted of tangled dislocations after shock loading and of cellular arrays after rolling. Misorientations within the grains were investigated using Kikuchi lines and were found to be small after both shock loading and rolling (to an equivalent hardness).


Ultramicroscopy | 1985

Twinned colloidal gold particles

A.G. Dhere; R.J. De Angelis; P.J. Reucroft; J. Bentley

Abstract The structural characteristics of colloidal gold particles prepared by reduction of gold chloride were studied. Images and microdiffraction patterns indicate that multiple twinning is commonly present in the gold particles which range in size from 15 to several hundred nm. Very good agreement was found between the twin-fault densities determined by TEM studies and X-ray diffraction results.


Journal of Molecular Catalysis | 1983

Structural characteristics of cobalt particles in a 9.5%Co-ZSM-5 catalyst

A.G. Dhere; R.J. De Angelis; P.J. Reucroft; J. Bentley

A detailed structural study of cobalt particles in a 9.5%Co-ZSM-5 catalyst was made using x-ray diffraction and analytical transmission electron microscopy. The results obtained from these two techniques show the cobalt particles contain a high concentration of basal plane stacking faults. On the average one out of every twelve basal planes is faulted. It is suggested that atoms of a particle which lie at positions on the surface where intersection stacking faults exist may be the origin of active sites.


Journal of Catalysis | 1985

In situ X-ray diffraction investigation of the structural characteristics of two Co/ZSM-5 catalysts

A.G. Dhere; R.J. De Angelis

Two CoZSM-5 catalysts, one prepared by impregnation with a cobalt nitrate/water media and the other impregnated by cobalt carbonyl, were investigated employing an in situ X-ray diffraction chamber mounted on a diffractometer. X-Ray diffraction patterns were obtained following each step in a sequence of processes on each catalyst. The water media-impregnated catalyst displayed the larger particle size and all characteristics remained constant following the initial reduction. The carbonyl-impregnated catalyst showed the formation of a large amount of CoO after exposure to HCO gas of 11 composition at 200 °C. Once the CoO formed it would continue to return after subsequent calcining and reduction treatments.


Journal of Catalysis | 1983

A method for separation of X-Ray diffraction patterns from Co-ZSM-5 catalysts

A.G. Dhere; R.J. De Angelis

Abstract A Fourier method to unfold an X-ray diffraction pattern from a mixture to obtain the X-ray pattern from one component in the mixture is developed. The method is applied to the X-ray pattern from the catalyst mixture of 9.5% Co on a ZSM-5 support to obtain the diffraction pattern from metallic cobalt. Analysis of the details of the cobalt pattern shows the cobalt to be hexagonal in structure and dispersed with an average particle size of 220 A. The shapes of the profiles indicate that the cobalt particles are heavily faulted on the basal plane.


MRS Proceedings | 1985

Morphological Developments of Nickel Particles in Supported Metal Catalysts

A.G. Dhere; R.J. De Angelis; P.J. Reucroft; J. Bentley; Gene E. Ice; A. Habenschuss

The morphology of nickel-containing phases at each stage during the treatment of a 12%Ni/Si/sub 2/ catalyst was studied. Liquid impregnated catalyst initially shows nickel nitrate uniformly dispersed on the surface of the silica in the form of a film. After calcining, large rafts of NiO with faceted surface pits are seen. The reduced catalyst contains bunched nickel particles or large rafts on the surface of the silica.


Archive | 1984

Application of X-Ray Diffraction Techniques to Study the Sintering of Catalysts

Robert J. De Angelis; A.G. Dhere; James D. Lewis; Hai-Ku Kuo

An x-ray diffraction single profile analysis method is presented which allows the calculation of the particle size distribution function (PSD). This method is verified by using it to analyze simulated diffraction profiles from single, duplex, triplex, and normal distributions of particle sizes. This method is employed to study the sintering of a nickel catalyst.


Archive | 1987

Synchrotron X-Ray Scattering for the Structural Characterization of Catalysts

R. J. De Angelis; A.G. Dhere; M. A. Maginnis; P.J. Reucroft; Gene E. Ice; A. Habenschuss


Archive | 1985

Nickel oxide morphology in nickel-silica catalysts

A.G. Dhere; P.J. Reucroft; R.J. De Angelis; J. Bentley


Archive | 1985

Morphological developments of nickel particles in supported metal catalysts. [On SiO/sub 2/ support]

A.G. Dhere; R.J. De Angelis; P.J. Reucroft; J. Bentley; Gene E. Ice; A. Habenschuss

Collaboration


Dive into the A.G. Dhere's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

J. Bentley

Oak Ridge National Laboratory

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

A. Habenschuss

Oak Ridge Associated Universities

View shared research outputs
Top Co-Authors

Avatar

Gene E. Ice

Oak Ridge National Laboratory

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Marc A. Meyers

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

H.-J. Kestenbach

Federal University of São Carlos

View shared research outputs
Top Co-Authors

Avatar

Hai-Ku Kuo

National Sun Yat-sen University

View shared research outputs
Researchain Logo
Decentralizing Knowledge