M.Tech. (Operations Management) / Please refer to full text to view abstract

Dissertation (doctoral)--Åbo akademi, 1775. / At head of title: M.G.H. Reproduction of original from Kress Library of Business and Economics, Harvard University. Goldsmiths'-Kress no. 11249.2-0.

MSc., Faculty of Science, University of the Witwatersrand, 2011 / This research focuses on the study of the impurities in low-strain high pressure, high temperature (HPHT) synthetic diamonds. The dominant characterisation methods are synchrotron-based x-ray techniques, supported by other conventional laboratory techniques. The research identifies the role of defects in generating long-range strain. A software programme based on the dynamical theory of x-ray diffraction has specially been developed to quantify the local changes in the lattice parameter and the local lattice inclinations (combined as the “effective misorientation” or local Bragg angle change). In recent measurements, the strain sensitivity of the (quantitative) x-ray plane-wave monochromatic topography was increased to the level of 10−8. This level of sensitivity was achieved using the double crystal technique with successively higher order reflections and correspondingly, higher energy x-rays. This is a level which has never previously been accessed for diamond. Preliminary results for this research have already contributed immensely to driving a technological development of a new range of diamond-based x-ray optical elements for modern third and fourth-generation x-ray sources like synchrotron storage rings and Free Electron Lasers (FEL), where industry (industrial diamond growers) and end-users (the synchrotrons of the world) participate collaboratively in a research and development programme.

Thesis (Ph.D.) - University of Glasgow, 2008. / Ph.D. thesis submitted to the Faculty of Physical Sciences, Department of Geographical and Earth Science, University of Glasgow, 2008. Includes bibliographical references. Print version also available.

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The Drybones Bay and Mud Lake kimberlites are Ordovician kimberlites located in the Slave Geological Province. The Drybones Bay pipe formed by multiple discrete eruptions, producing several texturally distinct phases of kimberlite, including hypabyssal kimberlite (HK) autoliths, tuffisitic kimberlite (TK), pyroclastic kimberlite (PK) and resedimented volcaniclastic kimberlite (RVK). The recognition of TK suggests this pipe represents a Class 1 kimberlite. The nearby Mud Lake kimberlite is a dolomite-rich HK dyke characterized by macrocrystic and segregation textures. Although the kimberlites are proximal, U-Pb zircon dates indicate they were not emplaced contemporaneously, and geochemical discrepancies that cannot be explained by known magma evolution processes indicate that these rocks formed from distinct parental magmas. Mineralogical and geochemical data is used to evaluate crystallization conditions and diamond potential. New geochemical modeling of compatible trace elements reveals convincing evidence of magma evolution by olivine fractionation, adding substantially to the published research on kimberlite geochemistry. / October 2016

X-ray machines that are designed to recover diamonds from an ore body, are used extensively on diamond mines. These machines are extremely expensive and at present, there are no reliable methods, outside the De Beers Group, of determining if the equipment is performing correctly. The object of this research was to manufacture X-ray translucent X-ray diamond simulants with known fluorescent signals ranging from bright to dim. These X-ray diamond simulants will then be used to evaluate the recovery efficiency of all X-ray machines on any diamond mine. The research successfully accomplished the following: 1) The design and building of optical equipment needed to measure the fluorescent signals produced by diamonds and the diamond simulants. 2) Setting up of equipment needed to manufacture the diamond simulants. 3) Determining the ingredients needed to make a diamond simulant and 4) Determining the recipe for the diamond simulants with different fluorescent signals, for diamonds of different sizes.

Ho, Sai Wah = 鑽石氮-空缺中心自旋的退相干研究及控制 / 何世華. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 62-68). / Abstracts in English and Chinese. / Ho, Sai Wah = Zuan shi dan-kong que zhong xin zi xuan de tui xiang gan yan jiu ji kong zhi / He Shihua. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- NV center in diamond --- p.6 / Chapter 2.1 --- Why NV centers? --- p.6 / Chapter 2.2 --- NV center --- p.8 / Chapter 2.3 --- Hamiltonian of the spin system --- p.11 / Chapter 3 --- Decoherence calculation - Cluster-correlation expansion --- p.13 / Chapter 3.1 --- The decoherence problem --- p.13 / Chapter 3.2 --- Quantum many-body theory: History and method --- p.17 / Chapter 3.3 --- General theory of cluster-correlation expansion --- p.19 / Chapter 3.4 --- Different physical processes and the pictorial understanding: Spin pathways in Bloch sphere --- p.21 / Chapter 3.4.1 --- Dynamical fluctuation versus inhomogeneous broadening --- p.21 / Chapter 3.4.2 --- Single nuclear spin dynamics --- p.22 / Chapter 3.4.3 --- Nuclear spin pair dynamics --- p.24 / Chapter 3.4.4 --- Higher order spin cluster dynamics --- p.27 / Chapter 4 --- Dynamical decoupling theories and experiments --- p.28 / Chapter 4.1 --- Dynamical decoupling: History --- p.28 / Chapter 4.2 --- Pulse sequences --- p.29 / Chapter 4.2.1 --- Spin echo (SE) --- p.30 / Chapter 4.2.2 --- Carr-Purcell-Meiboom-Gill (CPMG) sequence --- p.31 / Chapter 4.2.3 --- Concatenated dynamical decoupling (CDD) --- p.31 / Chapter 4.2.4 --- Uhrig dynamical decoupling (UDD) --- p.32 / Chapter 5 --- Dynamics of the spin clusters --- p.34 / Chapter 5.1 --- Convergence of CCE under external magnetic field and pulse sequence --- p.34 / Chapter 5.2 --- Zero magnetic field regime: single spin and spin pair induced dynamics --- p.35 / Chapter 5.2.1 --- Free induction decay --- p.36 / Chapter 5.2.2 --- Dynamical decoupling control: UDD1-5 --- p.37 / Chapter 5.3 --- Small magnetic field regime: Single spin and spin pair induced dynamics --- p.38 / Chapter 5.3.1 --- Single spin induced dynamics: single spin induced re- vivals under dynamical decoupling sequences --- p.38 / Chapter 5.3.2 --- Single spin induced dynamics: Periodicity of revivals un- der different dynamical decoupling sequences --- p.42 / Chapter 5.3.3 --- Single spin induced dynamics: Short time modulation and envelope under the effect of Fermi contact and dy- namical decoupling sequences --- p.45 / Chapter 5.3.4 --- "Single spin and spin pair induced dynamics: Revival, os- cillation and decay under dynamical decoupling sequences" --- p.48 / Chapter 5.4 --- Large magnetic field regime: Single spin and spin pair induced dynamics --- p.50 / Chapter 5.4.1 --- Free induction decay --- p.50 / Chapter 5.4.2 --- Dynamical decoupling control: UDD 1-5 --- p.52 / Chapter 6 --- Application: Atomic scale magnetometry --- p.55 / Chapter 7 --- Conclusion --- p.59 / Bibliography --- p.62 / Chapter A --- Derivation of modulation and envelope frequency using second order perturbation theory --- p.69

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science / The aim of this work was to evaluate the measurement of the optical properties as a means of obtaining information on the growth history of synthetic diamond. A suite of sample of known synthesis origin representing the different types of commercially produced synthetic diamond was analysed hy photoluminescence. The photoh.{fnmescence intensity was normalising by using the area of tbe Raman peak. This allowed a semi-quantitative comparison of the defect concentration. Three photoluminescent centres were identified, H3, 575 run and 1.945 eV (with zero-phonon lines at 2.463 eV, 2.156 eV, and 1.945 eV respectively). Differences between the intensities of the luminescence due to these centres were observed as a function of the type ot diamond The H3 amd the 1.945 eV intensity was found to increase with the proportion of cubic growth sector, In addition the 1.945 eV intensity was found to increase with heat treatment and was higher in (100) than in (111) growth sectors. As all three defects detected involve vacancies and nitrogen impurity, an analysis was done to quantify any correlation between the luminescent intensities from the different defects in the same SDA powder sample. The 1.945 eV and 575 run intensities were observed to be correlated .. An additional correlation 'was found between the 575 lim and the H3 intensities in the case of finer particle size samples. The luminescence intensity for all three defect types was observed to be a function of the particle size of the sample. The shapes and widths of zero-phonon lines were related to the types and concentration of lattice defects present in a crystal according to line broadening theory. An attempt was made to explain the results in the context of the known synthesis origin and growth conditions. / AC 2018

The viability of using pulsed laser excited Raman spectroscopy as a method for diamond detection from ore, has been investigated. In this method the spontaneous Stokes Raman signal is used as indicator of diamond, and a dual channel system is necessary for correcting for fluorescence of minerals and diamond itself. Various pulsed laser wavelengths from 266 to 1064nm were used, as well as cw lasers for comparison. Wavelength scans of the regions of interest, indicated that pulsed lasers at 532, 355 and 308nm may be used with confidence for this purpose. Mineral fluorescence did not appear to pose a threat to the method, but rather own fluorescence of some types of diamonds. In this respect, pulsed lasers offer a decided advantage above cw, due to nonlinear increase of fluorescence with laser power, resulting in superior Raman to fluorescence signal ratios. An apparatus constructed for discriminating diamond from ore was evaluated, and using minerals commonly occurring in diamond carrying ore as well as a wide variety of diamonds, it proved to function effectively. A significant improvement in the capability for diamond detection was found when pulsed lasers at 532 and 308nm were used, in comparison to the 532nm cw laser.