Ray L. Frost

Bio: Ray L. Frost is an academic researcher from Queensland University of Technology. The author has contributed to research in topics: Raman spectroscopy & Infrared spectroscopy. The author has an hindex of 86, co-authored 1356 publications receiving 41053 citations. Previous affiliations of Ray L. Frost include University of Western Sydney & Southwest University of Science and Technology.

Kaolinite hydroxyls - a Raman study microscopy

Abstract: Raman microscopy of the kaolinite polymorphs was used to study single crystals and bundles of aligned crystals of kaolinite. The spectra of the hydroxyl stretching region were both sample and orientation dependent. Kaolinites can be classified into two groups according to the ratio of the intensities of the 3685 and 3695 cm -I bands. No relationship was found between the d-spacing and the crystal domain size measurement from the 001 reflection and the Raman spectral intensities indicating the Raman spectra are independent of d-spacing and crystallinity. However, a relationship of the crystallinity in the a-b direction and intensities of the 3685 and 3695 cm -1 bands indicate that the relative position of one layer to the other determines the position of the inner surface hydroxyl groups and the hydrogen bonding with the oxygen of the opposite layer. A new hypothesis based on symmetric and non-symmetric hydrogen bonding of the inner surface hydroxyl groups is proposed to explain the two inner surface hydroxyl bands centred at 3685 and 3695 cm -1, The bands at 3670 and 3650 cm -1 are described in terms of the out-of-phase vibrations of the in-phase vibrations at 3695 and 3685 cm -1.

Copyright 2008 Elsevier The structure of mimetite, arsenian pyromorphite and hedyphane -a Near Infrared spectroscopic study

Abstract: Electronic and vibrational spectra of mimetite, arsenianpyromorphite and hedyphane minerals have been analysed and the spectra related to the mimetite and arsenian pyromorphite and hedyphane mineral structure. The chief spectral feature in the electronic spectra at ~10000 cm -1 (1.00 µm) with variable band position and intensity results from the ferrous ion. The splitting of Fe(II) band is large in mimetites with a separation of 1415 cm -1 . An additional band shown by arsenian pyromorphite at 10735 cm -1 (0.93 µm) is assigned to Cu(II) dd-transition. The substitution of Fe(II) causes a blue shift for Cu(II) band in mimetites and the intensity of this band is enhanced at ~11140 cm -1 (0.90 µm). The change in colour from brown to orangeyellow relates to the amount of Cu and/or Fe impurities in the mimetite minerals. The presence of OH-stretching overtones at 7000 cm -1 (1.43 µm) is the result of OH substitution for Cl. Phosphate ion bands are produced in arsenian pyromorphite, hedyphane and mimetite-3. Arsenian pyromorphite spectrum is a mixed profile dominated by PO stretching vibrations at 1100-900 cm -1 . The spectrum of hedyphane is significant with arsenate bands at 900-700 cm -1 and weak bands appear on either side of this due to the phosphate ion. The absence of phosphate ion group of bands and the presence of (AsO4) 3- bands near 800 cm -1 in selected mimetites is evidence for isomorphic substitution of (AsO4) 3- by (PO4) 3- .

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Single Sheet Functionalized Graphene by Oxidation and Thermal Expansion of Graphite

Abstract: A detailed analysis of the thermal expansion mechanism of graphite oxide to produce functionalized graphene sheets is provided. Exfoliation takes place when the decomposition rate of the epoxy and hydroxyl sites of graphite oxide exceeds the diffusion rate of the evolved gases, thus yielding pressures that exceed the van der Waals forces holding the graphene sheets together. A comparison of the Arrhenius dependence of the reaction rate against the calculated diffusion coefficient based on Knudsen diffusion suggests a critical temperature of 550 °C which must be exceeded for exfoliation to occur. As a result of their wrinkled nature, the functionalized and defective graphene sheets do not collapse back to graphite oxide but are highly agglomerated. After dispersion by ultrasonication in appropriate solvents, statistical analysis by atomic force microscopy shows that 80% of the observed flakes are single sheets.