We have observed two high -redshift quasars with the echelle spectrograph and 2D- Frutti Photon Counter at Las Campanas, in order to investigate the statistical properties of the Lyman -a forest. The two-point correlation function for the Lyman -a forest lines at z .^s 3 is consistent with zero, for all velocity splittings A > 50 km /sec. When Lyman -a lines and other metal lines from known metalline systems are included, the correlation function shows a weak non -zero signal at small A . We suggest that the weak clustering of the Lyman -a forest detected by other workers may be the result of contamination by a small number of metal -line systems and their associated Lyman -a lines.

We present evidence for redshift quantization in the Lyman -a forest of several QSOs. The Ly -a data are at redshifts z from 1.89 to 3.74, and the theory of redshift quantization proposed by Cocke (1983, 1085) is used to scale the quantization interval (24.15 km s -') to these high redshift. The sealing depends on the deceleration parameter qo, and the quantization is present at a statistical significance of greater than 99% for qo = 1/2. This may be taken as confirming the inflationary model of the early history of the universe. The significance of the quantization is highest at go rs 0.48, and the width of the peak is about 0.03 . The result can also be seen as providing confirmatory evidence for both the theory of the redshift quantization and the above value of qo, but at a significance of only 03 %. The scenario proposed for the relativistic generalization of the theory is that of fermion wavefunctione and quantum operators in a background Riemannian spacetime satisfying Einstein's field equations.

4 pp. / This short fact sheet is taken from "Arizona Well Owner's Guide to Water Supply" currently in print. We plan to complete part 2 of this fact sheet by the end of July, 2009. Please note that the text has already been incorporated into the eXtension Community of Practice web page - - I am the author for the COP/Drinking Water group text on chemistry of naturally occurring water contaminants. / Arizona well water is often contaminated with elevated concentrations of naturally occurring constituents that are a human health concern. This short fact sheet is the first in a two-part series about what naturally occurring contaminants may be found in your water supply well and includes a brief discussion on environmental pollutants that originate from land use activities. If you own a well in Arizona, you have the sole responsibility for checking to see if your drinking water is contaminated. Arizona state law does not require private well owners to test or treat their water for purity. The second part of this series outlines what to sample for and how to understand your analytical results.

This thesis addresses various issues in U-Pb zircon geochronology, proposing new experimental protocols in conventional chemical abrasion-isotope dilution thermal ionization mass spectrometry or CA-(ID)-TIMS and developing a new method for Pb evaporation-condensation from zircon that allows high precision Pb-Pb age determination on Precambrian samples. Various experiments are also done on zircon to extract U-Pb information by in situ flux aided fusion methods and to optimize a better silica gel Pb-ionization activator. Radiation damage caused by U decay in zircon disrupts its ‘closed system’ behavior leading to the loss of daughter radiogenic Pb and resulting in inaccurate ages. A high temperature thermal annealing procedure has been proposed to prevent such Pb loss. Studies presented here have been carried out using Laser Raman Spectroscopy and Scanning Electron Microscopy to characterize radiation damage and effects of laboratory induced thermal annealing on such damage. Backscattered electron images reveal a variety of textures for ZrO2 overgrowths on zircon annealed at 1450oC. Highly damaged zircon produces finer polycrystalline aggregates (<5µm) than zircon with less damage. Raman spectroscopy indicates that crystals with different levels of radiation damage are only partially restored by annealing at 1000oC for 2–3 or 20 days. Annealing at 1450oC for 1 h results in partial breakdown of zircon but restores Raman peak widths and wave numbers. Raman spectra are much less sensitive to polarization angle for annealed highly damaged grains than for weakly damaged zircon showing that when highly damaged zircon is recrystallized, it becomes a polycrystalline aggregate that pseudomorphs the original single crystal. The whole grain Pb evaporation-condensation method is based on 206Pb-207Pb age analyses where zircon grains are pre-treated at 1450oC to drive out all disturbed Pb and then they are kept at 1600oC for an hour or two during which Pb atoms are evaporated out of the grain and deposited directly into a clean Savillex teflon vial or a wide Re filament. This technique allows the use of a 202Pb-205Pb double spike for precise isotopic fractionation correction. Examples are shown in which application of this technique to zircon from Precambrian samples has successfully yielded sub-million year age precisions.

This thesis addresses various issues in U-Pb zircon geochronology, proposing new experimental protocols in conventional chemical abrasion-isotope dilution thermal ionization mass spectrometry or CA-(ID)-TIMS and developing a new method for Pb evaporation-condensation from zircon that allows high precision Pb-Pb age determination on Precambrian samples. Various experiments are also done on zircon to extract U-Pb information by in situ flux aided fusion methods and to optimize a better silica gel Pb-ionization activator. Radiation damage caused by U decay in zircon disrupts its ‘closed system’ behavior leading to the loss of daughter radiogenic Pb and resulting in inaccurate ages. A high temperature thermal annealing procedure has been proposed to prevent such Pb loss. Studies presented here have been carried out using Laser Raman Spectroscopy and Scanning Electron Microscopy to characterize radiation damage and effects of laboratory induced thermal annealing on such damage. Backscattered electron images reveal a variety of textures for ZrO2 overgrowths on zircon annealed at 1450oC. Highly damaged zircon produces finer polycrystalline aggregates (<5µm) than zircon with less damage. Raman spectroscopy indicates that crystals with different levels of radiation damage are only partially restored by annealing at 1000oC for 2–3 or 20 days. Annealing at 1450oC for 1 h results in partial breakdown of zircon but restores Raman peak widths and wave numbers. Raman spectra are much less sensitive to polarization angle for annealed highly damaged grains than for weakly damaged zircon showing that when highly damaged zircon is recrystallized, it becomes a polycrystalline aggregate that pseudomorphs the original single crystal. The whole grain Pb evaporation-condensation method is based on 206Pb-207Pb age analyses where zircon grains are pre-treated at 1450oC to drive out all disturbed Pb and then they are kept at 1600oC for an hour or two during which Pb atoms are evaporated out of the grain and deposited directly into a clean Savillex teflon vial or a wide Re filament. This technique allows the use of a 202Pb-205Pb double spike for precise isotopic fractionation correction. Examples are shown in which application of this technique to zircon from Precambrian samples has successfully yielded sub-million year age precisions.

Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.

Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.