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Page 1. Chapter 2 Thin-Film Elemental Analyses for Precise Characterization of Minerals Ian DR Mackinnon Electron Microscope Centre, University of Queensland, St. Lucia QLD 4067, Australia ... Page 4. 2. MACKINNON Thin-Film Elemental... more
Page 1. Chapter 2 Thin-Film Elemental Analyses for Precise Characterization of Minerals Ian DR Mackinnon Electron Microscope Centre, University of Queensland, St. Lucia QLD 4067, Australia ... Page 4. 2. MACKINNON Thin-Film Elemental Analyses 35 ...
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... Palygorskite was discovered for the first time in Azraq basin, during an investigation of the clay minerals in Azraq basin. ... X-ray diffraction and scanning electron microscopy (SEM) show that palygorskite is the dominant clay... more
... Palygorskite was discovered for the first time in Azraq basin, during an investigation of the clay minerals in Azraq basin. ... X-ray diffraction and scanning electron microscopy (SEM) show that palygorskite is the dominant clay mineral. ...
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Boron carbides exhibit an anomalously large Seebeck coefficient with a temperature coefficient that is characteristic of polaronic hopping between inequivalent sites. The inequivalence in the sites is associated with disorder in the... more
Boron carbides exhibit an anomalously large Seebeck coefficient with a temperature coefficient that is characteristic of polaronic hopping between inequivalent sites. The inequivalence in the sites is associated with disorder in the solid. The temperature dependence of the Seebeck coefficient for materials prepared by different techniques provides insight into the nature of the disorder.
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Measurements of the electrical conductivity, Seebeck coefficient and Hall mobility from -300 K to -1300 K have been carried out on multiphase hotpressed samples of the nominal composition B6Si. In all samples the conductivity and the... more
Measurements of the electrical conductivity, Seebeck coefficient and Hall mobility from -300 K to -1300 K have been carried out on multiphase hotpressed samples of the nominal composition B6Si. In all samples the conductivity and the p-type Seebeck coefficient both increase smoothly with increasing temperature. By themselves, these facts suggest small-polaronic hopping between inequivalent sites. The measured Hall mobilities are always low, but vary in sign. A possible explanation is offered for this anomalous behavior.
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Two samples of boron carbide have been examined using high resolution transmission electron microscopy (HRTEM). A hot-pressed BââCâ sample shows a high density of variable width twins normal to (10*1). Subtle shifts or offsets of lattice... more
Two samples of boron carbide have been examined using high resolution transmission electron microscopy (HRTEM). A hot-pressed BââCâ sample shows a high density of variable width twins normal to (10*1). Subtle shifts or offsets of lattice fringes along the twin plane and normal to approx.(10*5) were also observed. A BâC powder showed little evidence of stacking disorder in crystalline regions.
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... User Name Password Sign In. Articles: Michael E. Zolensky and; Ian DR Mackinnon. Microstructures of ... From the Cover. Ruiz Cruz: Ammonium vermiculite; Lee et al.: Natrolite is not a "soda-stone" anymore; Mosenfelder et... more
... User Name Password Sign In. Articles: Michael E. Zolensky and; Ian DR Mackinnon. Microstructures of ... From the Cover. Ruiz Cruz: Ammonium vermiculite; Lee et al.: Natrolite is not a "soda-stone" anymore; Mosenfelder et al.: Analysis of hydrogen in olivine by SIMS; ...
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A description is presented for the most common carbon phase in carbon-rich chondritic porous (CP) aggregate collected from the stratosphere by NASA researchers as part of the Cosmic Dust Program. An extraterrestrial origin was confirmed... more
A description is presented for the most common carbon phase in carbon-rich chondritic porous (CP) aggregate collected from the stratosphere by NASA researchers as part of the Cosmic Dust Program. An extraterrestrial origin was confirmed for the samples by microscopic examinations. The sample grains contained 45 percent carbon-rich phases and 30 percent low-temperature phases. Studies of the d002 interlayer spacing of the carbon clumps indicated that graphitization occurred at metamorphic temperatures after solar nebular condensation, yet early in solar system formation. Graphitized terrestrial materials served as a useful reference against which the CP materials were compared.
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Sampling of the El Chichón stratospheric cloud in early May and in late July, 1982, showed that a significant proportion of the cloud consisted of solid particles between 2 μm and 40 μm size. In addition, many particles may have been part... more
Sampling of the El Chichón stratospheric cloud in early May and in late July, 1982, showed that a significant proportion of the cloud consisted of solid particles between 2 μm and 40 μm size. In addition, many particles may have been part of larger aggregates or clusters that ranged in size from < 10 μm to > 50 μm. The majority of individual grains were angular aluminosilicate glass shards with various amounts of smaller, adhering particles. Surface features on individual grains include sulfuric acid droplets and larger (0.5 μm to 1 μm) sulfate gel droplets with various amounts of Na, Mg, Ca and Fe. The sulfate gels probably formed by the interaction of sulfur-rich gases and solid particles within the cloud soon after eruption. Ca-sulfate laths may have formed by condensation within the plume during eruption, or alternatively, at a later stage by the reaction of sulfuric acid aerosols with ash fragments within the stratospheric cloud. A Wilson-Huang formulation for the settling rate of individual particles qualitatively agrees with the observed particle-size distribution for a period at least four months after injection of material into the stratosphere. This result emphasizes the importance of particle shape in controlling the settling rate of volcanic ash from the stratosphere.