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Abstract  

Six artifacts from a Hopewell mound located near Mt. Vernon, Indiana, and 21 geologic specimens from three different chert sources in the Ohio River Valley were analyzed by instrumental neutron activation analysis. Principal components analysis and posterior classification of the artifacts on the basis of Mahalanobis distance calculated probabilities were used to determine the most probable source for each of the artifacts.

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Abstract  

Results are presented from the INAA of 34 elements in NIST and USGS geological reference materials that were analysed relative to multielemental SRM-1633a Coal Flyash standards. The data compare favorably with works reported by other investigators. The application of historical control charts for continuous monitoring of quality assurance and detection of systematic errors is demonstrated.

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Abstract  

Many of the initial applications for activation analysis occurred in the fields of archaeology, geochemistry and cosmochemistry. In addition to the desire to investigate noteworthy problems of interest to these disciplines, the reasons for employing activation analysis were based on the advantages of sample preparation, sensitivity, multi-element capability, and non-destructiveness. Nearly fifty years later and despite the development of several new analytical methods, we find that many of these same advantages continue to attract interest in activation analysis from these same disciplines. This overview discusses the past, present and future role of activation analysis with regard to research questions in archaeology, geochemistry, and cosmochemistry.

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Abstract  

The large and expanding field of modern high technology based upon silicon and its compounds is ideally suited for INAA using parametric counting, since neither the silicon nor the impurities present in almost infinite dilution give rise to self-shielding effects. Parametric counting, however, requires a fast and convenient method for determining the thermal, resonance, and fast neutron fluxes during irradiation. The resonance flux should be measured close to 5 eV, because most of the analytically important isotopes with large Ipo values have their resonance energies in the 1–15 eV region, and because the resonance flux in a commercial reactor does not follow the theoretical 1/E distribution in energy. It is shown in this paper that the resonance flux as measured with the “zirconium method” is practically identical to the resonance flux obtained from cadmium ratio measurements on gold. In addition, the zirconium monitor also yields the thermal and fast fluxes, and has several practical advantages, especially for longer irradiations.

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Abstract  

We address three main topics in this paper. First, we briefly review the history of neutron activation analysis (NAA) as an archaeological tool in the United States and Canada. Second, we assess the current potential for undertaking NAA in North America. Third, we comment on methodological and technical issues in archaeometric NAA that are raised by other papers included in this special section.

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Abstract  

A new instrumental epithermal neutron activation analysis procedure to quantitatively determine titanium, barium, and bromine in obsidian with improved sensitivity has been developed. The advantage of epithermal activation for Ti, Ba, and Br is demonstrated with multiple geological standards and the ability to determine arsenic in obsidian is demonstrated. The results for titanium are compared to previous electron-microprobe results for Kenyan obsidian.

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INAA of coals from the Midwestern USA

I. Chemical compositions

Journal of Radioanalytical and Nuclear Chemistry
Authors: D. Provance, M. Glascock, and K. Applin

Abstract  

The concentrations of 43 elements were determined in coal samples collected from the state of Missouri using INAA at the University of Missouri Research Reactor. The results of the whole coal analysis reveal that the chemical compositions of Missouri coals are highly variable. Enrichment factors were determined for each of the elements determined in this project to provide a measure of the relative enrichment of the element as compared to the average crustal abundance for that element. Most elements are relatively depleted in coals, however the elements As, Br, B, Ca, Cd, Cl, Fe, Mo, Ni, Sb, S, U, Zn and Zr were found to be enriched in Missouri coals. The determination of the relative enrichment of a given element in coal will allow a greater assessment of the environment impact the will be incurred from the use of that coal.

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Abstract  

A boron nitride irradiation vessel designed for use with a pneumatic tube transfer system has been used to analyze short-lived radionuclides by NAA. Bare and Cd-shielded irradiations on Co, Zr and Au were made to characterize the neutron fluxes in the irradiation position. Bare and BN-shielded irradiations were performed to determine epithermal advantage factors for 16 short-lived reactions and interference factors for a total of 11 (n, p) and (n, ) reactions induced by reactor fast neutrons. To illustrate application of these data, several biological and geological reference materials were analyzed.

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INAA of coals from the Midwestern USA

II. Assessment of the relative pollution potentials

Journal of Radioanalytical and Nuclear Chemistry
Authors: D. Provance, M. Glascock, and K. Applin

Abstract  

Coal leachates were prepared by leaching the coals analyzed in Part 1 of this project in solutions having initial pH values ranging from 4 to 8. The concentrations of 30 elements were determined in the coal leachates using INAA. The pH of the leachate solutions was allowed to drift during the course of the experiment. Following a leaching period of two weeks the pH of the leachates was measured to determine which of the leachates had the greatest potential for producing highly acidic waste-waters. The results of the elemental analysis of the leachates were compared to Maximum Acute Toxicity Effluent (MATE) values to establish the pollution potentials for the coal leachates. The elements Al, As, Ca, Co, Fe, Mn and Zn were found to exceed MATE values in at least one leachate; Ca and Mn exceed MATE values in all of the leachates. A comparison between the chemical compositon of the coal leachates, the final pH of the leachates and MATE values reveals that the leachates that exhibit the lowest final pH contain the largest number of elements that exceeded MATE values and have the greatest potential for producing toxic leachates.

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Abstract  

Sixty Mesa Verde variety Black-on-white bowls from Castle Rock Pueblo (5MT1825) and Sand Canyon Pueblo (5MT765) in southwestern Colorado were chemically characterized using neutron activation analysis. Eleven clay sources local to the sites in the McElmo Drainage area were also analyzed. The results revealed two distinct compositional groups containing relative frequencies that imply local production. The occurrence of trade between the two sites was also identified.

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