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D Dingley

Publications and source records attributed to D Dingley.

5 recordsLinked to original sources
PubMed2004

Microstructural and microtextural characterization of oxide scale on steel using electron backscatter diffraction.

High-temperature oxidation of steel has been extensively studied. The microstructure of iron oxides is, however, not well understood because of the difficulty in imaging it using conventional methods, such as optical or electron microscopy. A knowledge of the oxide microstructure and texture is critical in understanding how the oxide film behaves during high-temperature deformation of steels and more importantly how it can be removed following processing. Recently, electron back-scatter diffraction (EBSD) has proved to be a powerful technique for distinguishing the different phases in scales. This technique gives valuable information both on the microstructure and on the orientation relationships between the steel and the scale layers. In the current study EBSD has been used to investigate the microstructure and microtexture of iron oxide layers grown on interstitial free steel at different times and temperatures. Heat treatments have been carried out under normal oxidation conditions in order to relate the results to real steel manufacturing in industry. The composition, morphologies, microstructure and microtexture of selected conditions have been studied using EBSD.

Ferric Compounds↗
PubMed2004

Progressive steps in the development of electron backscatter diffraction and orientation imaging microscopy.

Ten years ago electron backscatter diffraction (EBSD) became available to a wider group active in materials research. This paper highlights some of the more significant developments in camera technology and software developments that have arisen since then. The use of slow-scan charge couple device cameras for phase identification and rapid determination of orientation image micrographs is reviewed. The current limiting spatial resolution of the technique is shown to be less than 10 nm. A procedure for improving lattice spacing measurement by utilizing the full resolution of the camera is described with experimental measurements on silicon and nickel showing relative errors of plus/minus 3%. An investigation of partially recrystallized aluminium shows how the recrystallized fraction can be extracted with confidence but that the mapping of substructure in the highly deformed regions is questionable. Phase identification is described for complex cases in which the phase data tabulated in standard databases do not correspond to what is observed in the EBSD patterns. Phase mapping in a complex mineral in which chemical data and EBSD data are collected simultaneously is shown to be improved by recording both the chemical and the EBSD data into computer memory and proceeding with the phase discrimination and orientation measurement in off-line analysis.

Crystallography↗
PubMed1985

Cryptosporidiosis outbreak in a day-care center.

An outbreak of diarrhea occurred in a day-care center in San Marcos, Tex, in August 1984. At the time of this study, the center was caring for 81 children aged 2 months through 5 years. A single stool specimen was collected from each of 50 children (62%). Cryptosporidium oocysts and Giardia lamblia cysts were each identified in stool specimens from 18 children. Three children had both parasites present in the same stool specimen. Echovirus 30 was identified in 19 of 25 stools cultured. Although three pathogens were circulating simultaneously in this group of children, only the presence of Cryptosporidium oocysts was associated with the occurrence of a diarrheal illness. Cryptosporidium may be a common cause of diarrhea in children who attend day-care centers.

Animals↗
PubMed1985

Macracanthorhynchus ingens from a child in Texas.

Nine acanthocephala recovered over a two-month period from the stools of a 10-month-old child in Texas were identified as Macracanthorhynchus ingens, a common intestinal parasite of the raccoon, Procyon lotor.

Acanthocephala↗