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A dissertation submitted in fulfilment of the requirements for the Degree of Master of Science in Archaeology to the Faculty of Science, University of Witwatersrand, 2019 / The study examines the technology of crystal quartz pieces from Pomongwe Cave (PMG), Matopos, and south-western Zimbabwe. It focuses on the Middle and Later Stone Age (MSA and LSA) assemblages, which were excavated in the early 1960s by C. K Cooke and is housed at the Zimbabwe Museum of Human Sciences (ZMHS) in Harare. The research employs the chaîne opératoire approach to the study of crystal quartz technology, which follows all the stages of lithic production from the sourcing of the raw material through exploitation, use and discard patterns. It seeks to understand how the hunter-gatherers at Pomongwe (PMG hereafter) exploited this material and how they adapted their technologies to suit the physical and mechanical properties of crystal quartz through time at the site. On a broader scale, the study contributes to our understanding of the development of Modern Human Behaviours (MHBs). The results of the study show that the sourcing of the crystals was mainly from a secondary context throughout the MSA and LSA sequence. The presence and distribution of the material also varied throughout the MSA and LSA sequence, suggesting that the raw material was more prominent with the inhabitants during certain periods than others. The results through classification also show that not all collected crystals were exploited for lithic production, which raises questions as to why they were collected. The cores and blanks show that the crystals were mainly opened from the pyramid and exploited going towards the base of the crystal. The most notable change in the exploitation of crystal quartz throughout the MSA and LSA sequence at PMG is that of the reduction in the sizes of the blanks going towards the LSA. / TL (2020)

In the event of large scale public radiation exposures, a means of rapid personal radiation dosimetry would provide a valuable tool for environmental and human health protection as well as for possible criminal investigations (in the event of terrorist dirty bombs). This thesis describes a method of sensitizing synthetic quartz oscillators, found in many timekeeping devices such as watches and cellular phones, to function as radiation dosimeters. Experiments on the sensitization of synthetic quartz crystals from watch oscillators were performed by subjecting the quartz to thermal treatments in the range of 200°C to 800°C. The lengths of treatments ranged from numerous one hour cycles to week-long single anneal treatments and combinations of the two. All treatments were designed to mimic factors that are known to cause sensitization in geologic quartz grains (Botter-Jensen, Larsen et al., 1995). The greatest sensitization was observed in crystals treated to 800°C for one week and then subjected to two series of heating, irradiation, and optical exposures. These crystals were able to recover doses as low as 0.5 Gray at an error within 10% of the delivered dose. This work is the first stage of development for creating dual purpose quartz oscillator-dosimeters which could be used in watches, cellular phones, clocks, and nearly all equipment requiring a timekeeping component. In the future, experiments should be conducted to show definitively that crystals still function as 32.768 kHz oscillators after annealing and that oscillators trap charge while in operation. / Thesis / Master of Science (MSc)

Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Janata, Jiri; Committee Co-Chair: Hunt, William; Committee Member: Allen, Mark; Committee Member: Brand, Oliver; Committee Member: Ferguson, Ian; Committee Member: Lyon, Andrew

Les publications scientifiques traitant de l’utilisation des matériaux quartz en préhistoire sont rarissimes comparé à celles traitant des roches siliceuses cryptocristallines comme le silex ou l’obsidienne. Pourtant, les populations humaines ont abondamment utilisé les divers matériaux réunis sous l’appellation « quartz » pour la confection de leur outillage, et ce depuis les périodes les plus reculées du Paléolithique Inférieur jusqu’aux époques modernes. Les raisons de cette sélection préférentielle des outils en silex comme matériel d’étude sont multiples. Outre le poids des approches traditionnelles à la Préhistoire où l’étude du silex est prépondérante, le matériel en quartz présente des difficultés d’études qui sont à la fois liées à la texture du matériau et à ses propriétés mécaniques, mais aussi à l’utilisation de méthodologies d’analyses dérivées de l’étude du silex et qui s’avèrent inadéquates ou mal adaptées pour le quartz de filon. Un premier chapitre introductif est ainsi destiné à présenter les principales causes du manque d’intérêt des préhistoriens envers les matériaux quartz. Nous proposerons, dans un second temps, de délivrer les principaux éléments de caractérisation minéralogique et pétrographique de ce que l’on nomme communément « quartz ». Le second chapitre est entièrement destiné à réunir et confronter les principaux résultats de quelques spécialistes pionniers ayant travaillé sur l’utilisation du quartz pour la confection d’un outillage lithique. Au travers de cette récolte de données informatives, il s’agira d’établir les principales caractéristiques des quartz de filon en termes de comportement à la taille et d’établir une liste des principaux critères technologiques, morphologiques et typologiques permettant son analyse. Le troisième chapitre est consacré à la présentation de la méthodologie d’analyse typo-technologique employé dans cette étude. Cette méthode se fonde principalement sur les divers critères exposés au sein du chapitre 2. Le quatrième et dernier chapitre est entièrement consacré à l’analyse des séries en quartz des sites néolithiques de Kovačevo (Bulgarie), Madžari (ARYM), Promachonas-Topolniča (frontière gréco-bulgare) et Dikili Tash (Grèce). L’objectif étant, à partir de la création d’une méthodologie de référence, de reconnaître les choix opérés par les sociétés néolithiques balkaniques dans la gestion et la production de leurs outillages domestiques. Ces choix sont évalués, en termes culturels, en établissant la part des contraintes environnementales, la disponibilité des ressources des domaines lithologiques locaux, les technologies utilisées ainsi que les grands domaines d’activités impliquant l’utilisation de la fraction quartz de l’outillage. Les modes de production de l’industrie du quartz seront aussi replacés dans la gestion de l’ensemble des industries néolithiques, du silex, mais aussi de la poterie, afin de comprendre leur place dans le système socio-économique des premières communautés agropastorales des Balkans. / Scientific publications dealing with the use of quartz in Prehistory are rare compared to those dealing siliceous cryptocristalline rocks such as flint, chert and obsidian. Yet, human populations have extensively used the various materials gathered under the appelation « quartz » for making their tools since the remotest times of the Lower Palaeolithic to modern times. The reasons for this preferential selection of flint tools as study materials are multiple. Besides the weight of traditional approaches to prehistoric times where the study of flint is predominant, quartz materials present difficulties of studies that are both related to the texture of the material and its mechanical properties, but also to the use of derivative methodologies of analysis of the study of flint that prove inadequate or unsuitable for vein quartz materials.An introductory chapter is thus intended to present the main causes of the lack of interest from prehistorians towards quartz materials. We then propose to deliver the main mineralogical and petrographic elements that characterize what is commonly called “quartz”.The second chapter is fully intended to unite and confront the main results of some pioneers specialists who have worked on the use of quartz for the manufacture of stone tools. This collection of informative data will help us establish the main features of vein quartz in terms of knapping behavior and also to list the main technological, morphological and typological criteria enabling its analysis.The third chapter is devoted to the presentation of the methodology used in this study. It consists of a typo-technological analysis mainly based on the various criteria outlined in chapter 2.The fourth and final chapter is fully devoted to the analysis of the quartz series from Neolithic sites Kovačevo (Bulgaria), Madzari (FYROM), Promachonas-Topolnica (Greek-Bulgarian border) and Dikili Tash (Greece). The objective is to recognize the choices made by the Balkan Neolithic societies in the management and production of their domestic tools. These choices are evaluated in cultural terms, establishing the share of environmental constraints, resource availability of local lithological domains, technologies and major areas of activity involving the use of quartz tools. The quartz industry production patterns will also be replaced in the management of the entire Neolithic industries, flint, but also pottery, to understand their place in the socio-economic system of the first agro-pastoral communities in the Balkans.

L’objectif de cette thèse est de synthétiser de nouvelles surfaces spécifiques nécessaires à l’immobilisation des biomolécules ; visant à développer à terme un biocapteur pour la détection de pathogènes en industrie agroalimentaire. Cette nouvelle procédure de fonctionnalisation de surface consiste d’une part à greffer des molécules organiques sur un substrat métallique à partir d’une réaction électrochimique et d’autre part de synthétiser un monomère photopolymérisable sur tout type de surface. Ces surfaces sont enfin utilisées pour immobiliser les biomolécules. Ce procédé ainsi développé permet d’éliminer les multiples étapes, l’utilisation excessive de réactifs observés dans les protocoles classiques de fonctionnalisation de surface pour la capture de microorganismes. Deux stratégies de fonctionnalisation ont été investiguées : la polymérisation sur une plaque de platine et le dépôt de monocouche sur une surface d’or. La fonctionnalisation de surfaces ainsi que l’immobilisation de biomolécules ont été caractérisées par la spectroscopie Raman, la microbalance à cristal de quartz, la microscopie à force atomique (AFM) pour le premier et en plus la microscopie à fluorescence pour le second. Les résultats de la fonctionnalisation de surfaces par dépôt de polymère ont montré, une déstabilisation du polymère en présence de l’eau. Afin d’optimiser la synthèse, nous avons travaillé en milieu inerte, sous alumine activée. De plus, on note une large couverture de la zone spectrale des biomolécules par les signaux du polymère ; Pour le dépôt de monocouche, l’on a obtenu une surface très réactive, homogène. La diffusion Raman est la principale technique de caractérisation utilisée. Elle présente l'avantage d'être une méthode de caractérisation physico-chimique non destructive et non invasive. Longtemps délaissée dans les sciences du vivant, cette méthode apparaît maintenant particulièrement prometteuse grâce à un développement récent de spectromètres intégrés performants. La diffusion Raman sur la monocouche déposée montre une intensité accrue des signaux par l’utilisation de la surface d’or et un spectre plus dégagé conduisant à l’identification aisée des biomolécules après fixation. Elle permet non seulement d’identifier les bandes de vibrations de chaque groupement mais aussi la conformation des structures. Les résultats d’immobilisation ont montré que l’accroche des biomolécules sur les surfaces fonctionnalisées était spécifique. La fonctionnalisation de surface d’or par dépôt de monocouche constitue finalement une technique très rapide à mettre en œuvre, peu coûteuse permettant d’ancrer efficacement les biomolécules et peut être utilisée pour diverses applications. La synthèse du monomère photopolymérisable a été abordée et est en cours d’investigation. / In food processing industry, detecting bacteria or viruses is crucial. Nowadays, it can be achieved with microbiological tests but, it requires several days. The objective of the project was to synthesize new specific surfaces capable of biomolecules immobilization in order to develop a biosensor for the detection of various pathogenics in food-processing industry. This new procedure of surface functionalisation consists on one hand in anchoring organic molecules on a metallic substrate by an electrochemical reaction and on the other hand to synthesize a photocrosslinkable monomer on every type of surface. These surfaces are finally used to immobilize biomolecules. Two strategies of surface functionalisation were investigated: the polymerization on a platinium surface and the deposition of monolayer on a gold surface. Both processes were characterized by spectroscopy Raman, Quartz Crystal Microbalance, Atomic Force Microscopy and Fluorescence Microscopy. The results of the functionalisation of surfaces by deposition of polymer showed a destabilization of the polymer in presence of water. To optimize the synthesis, we worked in sluggish middle, under activated alumina. Furthermore, we noted a wide coverage of the spectral zone of biomolecules by the signals of the polymer; For the monolayer deposition, we obtained a very reactive and homogeneous surface. The Raman spectroscopy was the main technique used to the characterization. It presented the advantage to be a non-destructive and non invasive physico-chemical method. This method seemed now particularly promising due to a recent development of successful integrated spectrometers. Raman Spectroscopy showed an enhanced intensity of the signals by the use of the gold surface and a more clear spectrum well-to-do identification of biomolecules after binding. It allowed not only the identification of the bands of vibrations of every connection but also the conformation of the structures. The results of the immobilization showed that the grafting of biomolecules on functionalised surfaces was specific and efficient. The functionalisation of gold surface by monolayer deposition constituted at the end an efficient and low cost technique allowing to anchor biomolecules and can be used for multitude applications. The last step consisting of the synthesis of photocrosslinkable monomer was started and still investigated.

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Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 26, 2007) Includes bibliographical references.

This thesis presents the results of a combined cathodoluminescence (CL) and electron paramagnetic resonance (EPR) spectroscopic study of quartz from the uranium-mineralized Athabasca Basin. CL imaging not only distinguishes detrital quartz grains from their secondary overgrowths but also is able to differentiate two generations of overgrowths in the Athabasca sandstones. Moreover, the Athabasca quartz samples are characterized by three types of bright CL: 1) haloes around U- and Th-bearing mineral inclusions, 2) patches associated with U-bearing minerals in matrices or pores and 3) continuous rims in samples with or without any visible U-bearing minerals. These three types of bright CL are all of constant widths of ~35-45 Ým, indicative of bombardments of alpha particles emitted from the 238U, 235U and 232Th decay series. CL spectral analyses show that the radiation damaged areas, relative to their undamaged hosts, are characterized by intense but broad emission bands at ~350 nm and 620-650 nm. <p>Detailed EPR measurements of the Athabasca quartz samples revealed six paramagnetic defects: one oxygen vacancy center (E1'), three silicon vacancy hole centers (O23¡V/H+(I), O23¡V/H+(II) and O23¡V/M+) and two O2¡V peroxy centers. Moreover, dissolution experiments using concentrated HF showed that that the silicon vacancy hole centers and the peroxy centers are concentrated in the radiation-damaged rims/fractures, whereas the oxygen vacancy center (E1') is evenly distributed in quartz grains. CL and EPR data of quartz samples after isochronal annealing experiments suggest that the silicon vacancy hole centers and the peroxy centers are most likely responsible for the characteristic ultraviolet CL and the red CL, respectively. <p>CL haloes in detrital quartz grains are ubiquitous in the Athabasca sandstones. CL patches are also widespread but are best developed in altered sandstones close to the unconformity or faults/fractures. Continuous CL rims, however, are more restricted in occurrences and are best developed at the high-grade Cigar Lake and McArthur River deposits, where they are restricted to lithological boundaries and faults and are pervasively developed in mineralized samples and associated alteration haloes close to the unconformity. At the Key Lake deposit, continuous rims occur only in mineralized samples close to the unconformity. Continuous CL rims are absent in basement rocks below mineralization, including those at the Cigar Lake and McArthur River deposits. The occurrence of radiation damages in Athabasca quartz have also been confirmed by detailed EPR measurements, which are significantly more sensitive than CL imaging. <p>Continuous CL rims on Athabasca quartz grains most likely record bombardments of alpha particles emitted from U-bearing mineralization fluids. Therefore, their associations with the unconformity, lithological boundaries and faults provide direct evidence for those structures being the pathways for mineralization fluids. The exclusive occurrence of continuous CL rims on detrital quartz grains and the abundance of U-bearing minerals in both generations of overgrowths suggest that U mineralization must have commenced during early diagenesis and continued during the formation of overgrowths. The absence of significant radiation damages in altered basement rocks supports the hypothesis that the basement was not a major source for uranium mineralization in the Athabasca basin. The common occurrence of CL haloes in euhedral quartz grains and CL patches associated with U-bearing minerals in faults, fractures and voids provide further (visual) evidence for late remobilization of uranium.