Doctor of Philosophy (PhD), Wright State University, 2012, Environmental Sciences PhD

Multiple cores from the Arctic were analyzed by XRF methods to determine the western Arctic lithostratigraphy as expressed in its geochemistry. In general, glacial and interglacial events have distinctly different chemistry. During glacial events, the sediments have elevated Ti, Fe, Rb, and Zr concentrations and depressed Sr and Mn concentrations. The opposite is true of the brown layers, where Ti, Fe, Rb and Zr are lower with higher levels of Mn and Sr. These data indicate that there are 18 chemically unique lithologic units (LUs) that exist among MIS-1 to MIS-16 age sediments. Isopach maps indicate two general depositional patterns appear to have existed during the late Quaternary. The first pattern is defined as a glacial depositional pattern based on sediment thicknesses present in Clark et al. (1980) SLUs F, H, J, and L. This pattern has the thickest deposits located on parts of the Northwind-Alpha Ridges as well as within the Makarov Basin. The second pattern is associated with interglacial deposits and is based on sediment thicknesses present in SLUs G, I, and K. The interglacial pattern is characterized by much thinner deposits especially for the central Arctic region. Based on the isopach sediment patterns, the potential source areas of the sediments deposited during the glacial and interglacial periods are slightly different. During glacial stages, a strong Canadian source area is suggested. During interglacial stages a Canadian source area exists for deposits in the Canadian Basin, and a potential mixture of Canadian and Russian source areas for sediments located along the Trans-Polar Drift between the Mendeleev-Lomonosov Ridges. Stratigraphic correlations indicate that the western Arctic, central Lomonosov Ridge, and eastern Arctic are geochemically different suggesting different sources for each area. Analysis of the coarse ice-rafted fraction (>250 μm) from strata associated with MIS-16 (LU-17) indicates a Canadian source for the carbonate grains in th (open full item for complete abstract)

Committee: Steve Higgins PhD (Committee Chair); Dennis Darby PhD (Committee Co-Chair); Leonid Polyak PhD (Committee Member); Thaddeus Tarpey PhD (Committee Member) Subjects: Oceanography

MS, University of Cincinnati, 2009, Arts and Sciences : Geology

Some short term climate reversals on the order of centuries are perceived to be generated by coupled feed backs in individual systems. It has been hypothesized that a significant pulse of fresh deglaciated water could be responsible for the capping of the upwelling and gyrecirculation in the North Atlantic Ocean consequently forcing a cooling in global temperature and a climate reversal. The catastrophic drainage of Lake Ojibway into the North Atlantic is a proposed trigger for the 8200 Cal. BP year cooling event. The objective of this study is to identify the stratigraphic signature of lake drainage and to assign some chronology to the stratigraphy. A stratigraphic record was developed based on cores from eleven lakes in transect from northeast Ontario 240 km southeast into the province of Quebec. The interpreted stratigraphy consists of a post Cochrane re-advance, ice proximal and distal sedimentation before final drainage and post drainage landscape stabilization. This stratigraphic record of Lake Ojibway provides a unique record which may be incorporated into a larger data set. Refined chronostratigraphic results may be integrated into larger studies with the objective of demonstrating a causal relationship between lake drainage, the capping of the North Atlantic circulation and a reversal in climate regime within the warmer Holocene.

Committee: Dr. Thomas Lowell (Committee Chair); Dr. Warren Huff (Committee Member); Dr. Madeleine Briskin (Committee Member); Dr. Andy Breckenridge (Committee Member) Subjects: Geology

MS, University of Cincinnati, 2004, Medicine : Industrial Hygiene (Environmental Health)

Residential lead abatement work frequently involves multiple tasks occurring simultaneously, making it difficult to determine the concentrations of air lead associated with individual tasks. Previous reports on air lead concentration at lead abatement sites have revealed that although lead abatement tasks can generally be ranked according to air lead level, there is a wide range of lead levels associated with the tasks. The hypothesis involved in the first phase of this study was to determine whether the higher lead concentrations for tasks which generally have low geometric mean concentration are associated with nearby activities with higher geometric mean air lead concentration. In the second phase of the study, paint lead levels in Singapore were determined in housing of various ages and in paints currently available for purchase by the public.

Committee: Dr. Scott Clark (Advisor) Subjects:

MS, University of Cincinnati, 2002, Medicine : Environmental Health Sciences

Soil samples collected in areas with potential lead contamination are generally analyzed using flame atomic absorption spectrometry (FAAS), inductively coupled plasma emission spectrometry (ICP-AES) or other laboratory methods. Laboratories, generally prepare sample for analyses by drying, and sieving to a homogenous fraction followed by acid digestion, all of which usually takes several days. Previous work has indicated that a field-portable x-ray fluorescence (XRF) analyzer is capable of producing soil lead results that are comparable to results by FAAS or ICP-AES. There would be considerable savings in time and effort if a field method, including sieving, could be developed which does not require laboratory digestion and analysis. Results could, therefore, be reported in a timelier manner to residents and others shortly after sample collection. The goal of this study was to determine the practicality of using the portable XRF analyzer in the field for analysis of lead on field-sieved soil samples. The practicality of using the XRF was determined by the amount of time it took to prepare and analyze the samples in the field and by the ease in which the procedure could be accomplished on site. Other objectives of the study included determining the effects of moisture on sieving the soil. When performing the field analysis, soil samples were desegregated and ground using a mortal and pestle and sieved through a No. 120 sieve pan to obtain particles <125 µm. Soil samples were obtained from yards of Cincinnati area housing built before 1978. Seventy-eight samples were collected and analyzed at 30 different locations. Mean soil lead concentrations were 816 ppm before drying and 817 ppm after drying by portable XRF, and 1042 ppm when digested and analyzed by FAAS. Correlation of field portable XRF and FAAS results were excellent for samples sieved to less than 125 µm with R-squared values of 0.992 and 0.9903 before and after drying respectively. The percent saturation of (open full item for complete abstract)

Committee: Dr. Scott Clark (Advisor) Subjects:

PhD, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

Lead is a toxic substance and a ubiquitous environmental contaminant. Many studies have shown its negative health effects on psychological development, neuromotor system and many other body organs. Lead was added to paint in the form of white lead to reinforce the paint and produce a tough and flexible film. It is estimated that more than 3 million tons of lead have been used in the form of lead-based paint in the U.S. during the past 100 years. As a result, about 38 million homes still contain leaded paint. For this reason, hundreds of millions of dollars have been spent in the U.S. for lead hazard control. The leaded particles aerosolized during lead hazard reduction work are a health hazard for the workers. Significant levels of leaded particles representing health hazards are aerosolized during lead abatement. Few studies regarding these aerosols have been performed. The two main goals of the research described in this dissertation were 1) to characterize the airborne leaded particles and 2) to apply the acquired knowledge to the evaluation of various lead hazard control procedures. The first goal was to investigate the fundamental characteristics of the particles aerosolized during lead abatement. An Environmental Test Chamber was designed and constructed in the Kettering building at the University of Cincinnati. Wood doors coated with lead-based paint were abated in the chamber by dry scraping, wet scraping, or dry machine sanding. The airborne particle concentration was measured with the Grimm particle size spectrometer. The size distribution of the airborne particles changed substantially with time. The airborne particle concentration for each specific size was found to decay exponentially in calm air condition. Size selective air sampling on filters and subsequent laboratory lead analysis of them showed no significant effect of particle size on the percent lead. The second goal was achieved by the following three studies. The first study was to investigate (open full item for complete abstract)

Committee: Dr. Sergey A. Grinshpun (Advisor) Subjects: Environmental Sciences

Master of Science, The Ohio State University, 2011, Chemistry

The compound [Ph3PMe]2B10I9CO2H was synthesized as a potential agent for the detection of occult tumor tissue in vivo using the X-ray fluorescence (XRF) of iodine. The compound is highly stable and its boron framework is not a native substrate for deiodinase enzymes, making it a potential carrier for iodine without sequestration by the thyroid. Future attachment of the compound to a tumor-seeking antibody through the carboxylic acid group will enable tumor specificity, such that high iodine concentrations can be achieved on cancerous cells. The target compound's precursor, [Ph3PMe]2B10H9CO2H was synthesized by a two-step procedure which first isolates [Ph3PMe]2B10H9CO. The structure of the carboxylic acid derivative was determined by single-crystal X-ray diffraction. Then the acid was periodinated to produce the target compound [Ph3PMe]2B10I9CO2H. The stability of Na2B12I12 and [Ph3PMe]2B10H9CO2H was established under high temperature conditions in aqueous solution in which neither compound noticeably degraded. The preliminary data suggest that both the attached iodine atoms and carboxylic acid group resist hydrolysis, thus the compounds may be suitable for future biological studies in cancer cell lines and mouse models. Both handheld and floor model XRF devices were used to assess iodide concentration in aqueous solution. The PANalytical wavelength-dispersive XRF was able to detect low concentrations of iodide in aqueous solution, with a limit of detection of 2 µM I−. Therefore, the technique in combination with the labeled antibody may be useful for the detection of tumor margins in vivo. It was found that the X-ray fluorescence of iodine on Cs2B12I12 is diminished compared to that of free iodide, but the signal of free iodide in an equimolar solution with Cs2B12H12 was unaffected. Additional experiments are required to determine why the attachment of iodine to the boron cage affects its fluorescence intensity and how the signal can be enhanced to ensure detecti (open full item for complete abstract)

Committee: Claudia Turro Dr. (Advisor); Sheldon Shore Dr. (Advisor) Subjects: Chemistry

MS, Kent State University, 2011, College of Arts and Sciences / Department of Earth Sciences

The Arctic Ocean sediment (AOS) is highly sensitive to global climate changes and has become a focus of much paleoclimatic research. In this study, paleoclimatic characteristics of the AOS have been studied using downcore X-Ray Fluorescence (XRF) data from 13 Healy-Oden TransArctic Expediton cores. Lithological and multi-element variations representing glacial and interglacial cycles were correlated using the variable-based Varimax-rotated Principal Component Analysis (VPCA) of the XRF data. The main components generated by the VPCA have been interpreted as related to terrigenous (erosional) sources (F1, Ti-K-Rb-Fe-Ba-Cr), changes in Laurentide Ice Sheet (LIS) (F3, Ca-P-I), pore water concentration/ biogenic productivity (F5, P-Cl-S), bottom-water ventilation (F6, Mn-Ni-Cu) and siliciclastics (F7, Sr-Zr). Component variations are well consistent with glacial (“gray beds”)-interglacial(“brown beds”) cycles and associated deglacial carbonate pulses in the core 8JPC with identified age controls of Adler et al., 2009 and Polyak et al., 2009. Mn-rich layers (corresponding F6 peaks) of interglacial origin are generally anticorrelated with Ca pulses (F3 peaks) generated during deglaciations. Cl data show general enhancement with interglacials and glacial gray beds with coarse detrital sand pulses suggesting saline pore water trapped within the porosity of these coarser beds. Pleistocene sedimentation is characterized with only a few shallow carbonate spikes, which indicate a weakened Beaufort Gyre and stronger Transpolar Drift as indicated by the lower abundance of Laurentide material in the Eurasian Basin. The Visible-Near Infrared (VNIR) derivative spectroscopy study of the sediment core P1-92AR-P25 (or P25) demonstrates cyclic variations in downcore mineralogy. VPCA of the downcore VNIR data show three mineral assemblages reflecting glacial–interglacial cyclicity. The results are consistent with clay mineral cycles identified by previous studies (Yurco et al. 2010) (open full item for complete abstract)

Committee: Joseph D. Ortiz (Advisor); Daniel K. Holm (Committee Member); Elizabeth M. Griffith (Committee Member) Subjects: Geology