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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The index of refraction of cerussite for X-rays

Field, James Edward, January 1900 (has links)
Thesis (Ph. D.)--University of Michigan, 1936. / Running title: X-ray refractivity of cerussite. "Reprinted from the Physical review, vol. 51, no. 3, February 1, 1937."
2

The index of refraction of cerussite for X-rays

Field, James Edward, January 1900 (has links)
Thesis (Ph. D.)--University of Michigan, 1936. / Running title: X-ray refractivity of cerussite. "Reprinted from the Physical review, vol. 51, no. 3, February 1, 1937."
3

A simple method for demonstration and measuring approximately the index of refraction of crystalline substances for X-rays

Hoyt, Howard Charles, January 1900 (has links)
Thesis (Ph. D.)--University of Michigan, 1935. / Cover title. "Reprinted from the Physical review, vol. 49, no. 7, April 1, 1936."
4

MINERALOGICAL CHARACTERIZATION OF TAILINGS AND RESPIRABLE DUST FROM LEAD-RICH MINE WASTE AND ITS CONTROL ON BIOACCESSIBILITY

Jaggard, Heather 29 February 2012 (has links)
One of the main risks that exposed and unvegetated tailings pose to the environment and human health is airborne dust that may be inhaled or ingested. In the case of Pb-bearing dust, both particle size and the identity of the Pb-hosting minerals affect the degree of risk. Finer dusts (<5µm diameter) have a higher potential of being ingested deeper into the human lung causing possible tissue damage and toxic effects. We have collected size-fractionated airborne dust and near-surface pH-neutral tailings at New Calumet Mine, Quebec, Canada, a former Pb-Zn mine. Bioaccessibility describes how much of a substance can be dissolved by body fluids and become available for absorption by the body. The most bioaccessible Pb compounds are PbCO3 (cerussite), Pb3(CO3)2(OH)2 (hydrocerussite) and PbO, followed by PbSO4 (anglesite), PbS (galena) and Pb5(PO4)3Cl (pyromorphite). Airborne dust samples were collected on the tailings piles using a PIXE Cascade Impactor which separates aerosol fractions onto nine impactor stages ranging from 16µm to 0.06µm. These stages were then analyzed by PIXE to obtain elemental concentrations. Samples of non-vegetated and vegetated near-surface tailings were collected for bioaccessibility tests as well as for total metal content, grain size distribution, and Pb speciation using ESEM and synchrotron techniques. Both airborne dust and near-surface tailings samples underwent synchrotron microanalysis including microXRD for identification of microcrystalline compounds and microXRF for element mapping and metal ratio evaluation. Despite extensive oxidation of iron sulfide minerals in the near-surface tailings, galena persists as the most abundant Pb-bearing phase in the pH-neutral tailings. However, rims of cerussite and hydrocerussite forming alteration rims on galena grains have been identified throughout the tailings. In vitro bioaccessibility testing of Pb in the tailings resulted in 0-0.05% bioaccessible Pb in lung fluid and 23-69% bioaccessible Pb in the gastric fluid. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-02-28 21:09:08.432
5

Dissolution, Transport, and Fate of Lead on Shooting Ranges

Scheetz, Caleb David 04 March 2004 (has links)
Shooting ranges concentrate significant quantities of heavy metals, especially lead as spent shot and bullets, on very small parcels of land. Samples taken from a shooting range near Blacksburg, VA, USA provide information about the reservoirs and pathways of lead at shooting ranges in an upland setting and humid environment. Metallic lead corrodes rapidly and develops a coating of corrosion products. The type and amount of corrosion products found on lead shot and bullets are best understood through examination of Eh-pH relationships. X-ray diffraction analysis identified hydrocerussite (Pb₃(CO₃)₂(OH)₂) as the corrosion phase present on lead shot recovered from the range. Hydrocerussite dissolution can produce soluble lead concentrations ranging from 2 ppb to 2 ppm for the soil pH values at this site. This soluble lead is captured by the soil. Sequential chemical extractions revealed that vertical lead migration beyond the A-horizon was minimal. The bound-to-Fe & Mn oxides and bound-to-carbonates soil fractions were identified as significant reservoirs for sequestration of lead in the soil. The highest concentration of extractable lead contained in the soil was directly correlated with the highest concentration of lead shot and bullets measured on the shotgun range surface. The geochemical framework for understanding the corrosion process, identifying the corrosion product(s) that control lead solubility, and identifying the geochemical barriers to lead migration that were employed at the Blacksburg, VA shotgun range, provides a basis for selecting best management practices for this and other shooting ranges. / Master of Science
6

The vibrational spectroscopy of minerals

Martens, Wayde Neil January 2004 (has links)
This thesis focuses on the vibrational spectroscopy of the aragonite and vivianite arsenate minerals (erythrite, annabergite and hörnesite), specifically the assignment of the spectra. The infrared and Raman spectra of cerussite have been assigned according to the vibrational symmetry species. The assignment of satellite bands to 18O isotopes has been discussed with respect to the use of these bands to the quantification of the isotopes. Overtone and combination bands have been assigned according to symmetry species and their corresponding fundamental vibrations. The vibrational spectra of cerussite have been compared with other aragonite group minerals and the differences explained on the basis of differing chemistry and crystal structures of these minerals. The single crystal spectra of natural erythrite has been reported and compared with the synthetic equivalent. The symmetry species of the vibrations have been assigned according to single crystal and factor group considerations. Deuteration experiments have allowed the assignment of water vibrational freque ncies to discrete water molecules in the crystal structure. Differences in the spectra of other vivianite arsenates, namely annabergite and hörnesite, have been explained by consideration of their differing chemistry and crystal structures. A novel approach to the assignment of site occupancy of ions in the erythrite - annabergite solid solution has been reported. This approach has utilised vibrational spectroscopy, in conjunction with careful consideration of the crystal structures of the minerals. It has been shown that in the erythrite - annabergite solid solution Coprefers metal site 2 contrasting nickel which prefers site 1. This study in conjunction with other studies has yielded the trend that the more electronegative metal prefers to occupy site 1, with the least electronegative metal preferring to occupy site 2. Fundamentally this thesis has increased the knowledge base of the spectroscopic properties of the aragonite and the vivianite minerals. The site occupancy of metal ion substitutions in solid solution series of the vivianite group of minerals has been further enhanced, with novel method of studying the site occupancy of ions in solid solutions has been developed. A detailed knowledge and understanding of factor group analysis applied to the study of minerals has been achieved.
7

Raman spectroscopy as a non-destructive screening technique for studying white substances from archaeological and forensic burial contexts

Schotsmans, Eline M.J., Wilson, Andrew S., Brettell, Rhea C., Munshi, Tasnim, Edwards, Howell G.M. January 2014 (has links)
No / Raman spectroscopy was evaluated as a non-destructive analytical tool for the characterisation of white substances in burials. In addition, Fourier transform Raman spectroscopy was used to assess the conversion of hydrated lime into calcium carbonate. Fourteen samples of white substances from archaeological and forensic sites were analysed and characterised. The results show that not all white residues in burials are lime. Lime can easily be mistaken for other building materials (gypsum), for minerals (brushite) or degraded metal (cerussite). This study highlights the need for chemical analysis of white residues when encountered in burials. Analytical information derived from Raman spectra of white substances can further assist in the interpretation of the taphonomic processes of burials and their funerary context. Copyright (c) 2014 John Wiley & Sons, Ltd.

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