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  • Author or Editor: S. Landsberger x
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Abstract  

The enormous utilization of phosphate rock and super phosphate derived from it have the potential of being an important factor in the contamination of aquifers with alpha emitting radionuclides and heavy metals. Both rock phosphate and super phosphate contain substantial levels of natural uranium, amounting to hundreds of ppm. Our study has shown that whereas the uranium series in phosphate rock is nearly in secular equilibrium, in super phosphate the226Ra and its progeny are depleted by 60–70%. This is a result of the chemical processing of the rock phosphate. On the other hand the super phosphate is much more soluble and can be expected to release its radionuclides to the environment more rapidly than rock phosphate. The present study explores the release of radioisotopes and heavy metals from phosphate fertilizers. Extensive analytical use has been made of a germanium well-detector/Compton suppression system.

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Abstract  

A program of compositional analysis using neutron activation has been performed on samples of Roman fineware from the Palatine East excavations in Rome at the University of Illinois' TRIGA reactor. These experiments are ultimately intended to assist the authors in advancing the understanding of the organization of pottery production and distribution in central Italy during the late Roman imperial period (4th–5th c. AD). The objectives of this paper are 1) to present an archaeological background of two regionally-produced finewares, 2) to discuss the methods of sampling, irradiation and data analyses, and 3) to demonstrate the preliminary results of our investigation, which included the analyses of Plio-Pleistocene clays from the Janiculum Hill in Rome.

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Abstract  

Arctic pollution is a problem of great concern, because its characteristics (transportation, assimilation into the environment, etc.) are complex and not fully understood. Detection of elemental constituents has been undertaken through the use of neutron activation analysis and Compton suppression (to lower the detection limits for radionuclides characteristic of mainly single gamma-ray emission) to discover possible pollutant sources. The goal of this project was to perform a feasibility study to determine the suitability of neutron activation analysis (NAA) to evaluate cadmium concentrations on air filters collected in the Arctic.

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Abstract  

Standard lead loaded Hypalon gloves deteriorate at an accelerated pace in the glovebox environments of Los Alamos National Laboratory. In an effort to minimize glovebox breaches, a project was undertaken to characterize polymer damage due to various environments. For one such study, experimental techniques were used to facilitate the use of a neutron source in damage studies involving glovebox gloves. In order to identify the radiation field experienced by the polymer samples, a characterization of the neutron source in the experimental setup was needed. The plutoniumberyllium source used was chosen to mimic an average neutron flux in a typical LANL glovebox. However, it was surmised that a more exact experimental flux should be found rather then using merely numerical analysis. Subsequent to ascertaining the impending neutron flux, polyurethane gloves show superior properties when compared against standard leaded Hypalon gloves; however, polyurethane is shown to degrade faster following neutron irradiation.

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Summary  

Halides, particularly Br- and Cl-, have been used as indicators of potential sources of Na+ and Cl- in surface water and groundwater with limited success. Contamination of groundwater and surface water by Na+ and Cl- is a common occurrence in growing urban areas and adversely affects municipal and private water supplies in Illinois and other states, as well as vegetation in environmentally sensitive areas. Neutron activation analysis (NAA) can be effectively used to determine these halogens, but often the elevated concentrations of sodium and chlorine in water samples can give rise to very high detection limits for bromine and iodine due to elevated backgrounds from the activation process. We present a detailed analytical scheme to determine Cl, Br and I in aqueous samples with widely varying Na and Cl concentrations using epithermal NAA in conjunction with Compton suppression.

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Abstract  

Airborne particulate matter (APM) was collected in coarse fraction and in PM2.5 during spring of 2002 in Beijing suburban sampling site by Gent SFU sampler. More attention has been paid to the special “events” such as dust, storm and haze. Taking advantage of the combination of thermal or epithermal neutron irradiation with Compton suppression spectrometer system, twenty elemental (Al, Si, Ca, K, Dy, Cu, I, In, Ba, W, Sn, Sb, As, Ti, Br, V, Mn, Cl, Na, Zn) concentration were determined. Among them, several key trace elements that cannot be accomplished by the traditional neutron activation analysis (NAA) were determined. The analysis of trace elemental concentration in PM2.5 shows that the anthropogenic elements such as As, In, Sn, Sb have different trends than crustal elements. The back-trajectories of the high concentration anthropogenic pollution elements revealed their source region. Six potential sources were resolved by positive matrix factorization (PMF), two area type and four source type, as soil, limestone quarry, crop burning and mixture of residue motor and coal burning sampling sites. Taking into account of everyday air particle back trajectories, source compositions together with source regions were also identified.

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Abstract  

A suite of shallow and deep subsurface waters from southwestern Illinois has been analyzed for chlorine (CT), bromine (Br), and sodium (Na+) using three different methods. Cl and Br were analyzed by ion chromatography (IC) and neutron activation analysis (NAA). Na was analyzed using inductively coupled plasma-atomic emission spectrometry (ICP-AESS) and NAA. In addition, five water standards were prepared with compositions over the range of Cl, Br, and Na concentrations in the natural waters were analyzed using the same methods. Analytical results for the prepared standards by the different methods were in good agreement. However, analytical results on natural waters yielded generally poor agreement between the methods. Our results suggest that solute concentrations and ratios between major solutes in subsurface waters determined by IC and ICP-AES may involve substantial laboratory error.

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Abstract  

During the past decade there has been a great emphasis on using multielemental methods to determine heavy metals in solid waste products arising from various industrial, combustion, municipal and mining activities. Furthermore, the study of the leaching characteristics of these solid wastes is of prime importance for environmental and regulatory considerations. We present an overview of neutron activation analysis (NAA), X-ray fluorescence (XRF) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for the analysis of solid wastes and leachates. In particular we discuss several matrix problems that are usually not considered in routine NAA measurements.

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Abstract  

During the past decade we have determined the concentrations of a variety of trace elements in the Arctic aerosol by using themal and epithemal neutron activation analysis (NAA). More recently we have employed Compton suppression NAA to lower the detection limits for radionuclides that are characteristic of single or mainly single gamma-ray emission. Using these various methods, we have been able to use elements such as indium and silicon. Furthermore we have achieved extremely low detection limits for iodine, arsenic and antimony. The usefulness of these NAA methods are discussed in a large sampling program that incorporates more than one thousand samples.

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Abstract  

Copper (Cu) is an essential element and is incorporated in many biomolecules that are involved in protecting the brain from oxidative damage. Many brain regions strongly affected by neurodegene rative diseases are small. A sensitive nondestructive procedure to determine Cu is desirable to preserve samples for additional studies. Copper is not easily determined by instrumental neutron activation analysis (INAA) due to high activity levels produced by major abundance elements such as sodium (Na) and chlorine (Cl), which produce a high Compton background. An INAA method involving a short epithermal neutron irradiation and counting with a Compton suppression system was developed to determine Cu in brain, via 5.1-min66Cu. These short irradiation results are compared to those based on coincidence spectrometry of annihilation photons from positron emitting 12.7-h64Cu after a long irradiation.

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