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L-Shell X-Ray Production Cross Sections for ₂₀Ca, ₂₆Fe, ₂₈Ni, ₂₉Cu, ₃₀Zn, ₃₁Ga, and ₃₂Ge by Hydrogen, Helium, and Lithium Ions

Description: L-shell x-ray production cross sections are presented for Fe, Ni, Cu, Zn, Ga, and Ge by 0.5- to 5.0-MeV protons and by 0.5- to 8.0-MeV helium ions and Ca, Fe, Ni, Cu, and Ge by 0.75- to 4.5-MeV lithium ions. These measurements are compared to the first Born theory and the perturbed-stationary- state theory with energy-loss, Coulomb deflection, and relativistic corrections (ECPSSR). The results are also compared to previous experimental investigations. The high precision x-ray measurements were performed with a windowless Si(Li) detector. The efficiency of the detector was determined by the use of thin target atomic-field bremsstrahlung produced by 66.5 keV electrons. The measured bremsstrahlung spectra were compared to theoretical bremsstrahlung distributions in order to obtain an efficiency versus energy curve. The targets for the measurement were manufactured by the vacuum evaporation of the target element onto thin foils of carbon. Impurities in the carbon caused interferences inthe L-shell x-ray peaks. Special cleansing procedures were developed that reduced the impurity concentrations in the carbon foil, making the use of less than 5 μg/cm^2 targets possible. The first Born theory is seen to greatly overpredict the data at low ion energies. The ECPSSR theory matches the data very well at the high energy region. At low energies, while fitting the data much more closely than the first Born theory, the ECPSSR theory does not accurately predict the trend of the data. This is probably due to the onset of molecular-orbital effects, a mechanism not accounted for in the ECPSSR theory.
Date: May 1992
Creator: McNeir, Michael Ridge
Partner: UNT Libraries

Nature of the Carbides of Iron

Description: From Abstract: "This bulletin analyzes and summarizes research at the Bureau of Mines dealing with the preparation, properties, and reactions of iron carbides in the 1948-60, part of which was sponsored by Wright Air Development Laboratories."
Date: unknown
Creator: Hofer, L. J. E.
Partner: UNT Libraries Government Documents Department

An Initial Study of Binary and Ternary Ti-based Alloys Manufactured Using Laser Engineered Net Shaping (LENSTM)

Description: In this study an initial assessment of the composition – microstructure – property relationships in binary and ternary Ti – based systems are made possible using LENSTM technology. Laser Engineering Net Shaping (LENSTM), a rapid prototyping, directed laser deposition methodology of additive manufacturing (AM) was used to create bulk homogenous specimens that are compositionally graded. Compositionally graded specimens were made possible by incorporating elemental blends of powder during the LENSTM process. While there have been numerous studies assessing the influence of common elements (e.g., V, Mo, Al, and Cr) on the resulting microstructure in titanium alloys, other elements have been neglected. A systematic study of the Ti – Fe – Al ternary system based upon varying compositions of the eutectoid former, Fe with Al to stabilize the a and b phases respectively has also been neglected. This research effort focuses on exploiting the LENSTM process by rapidly assessing the composition – microstructure – property relationships in a combinatorial approach for the Ti – W, Ti – Fe, and Ti – Fe – Al systems. Compositionally graded specimens of Ti – xW (0<x<40wt.%(14.79at.%)), Ti – xFe (0<x<35wt.%(36.37at.%)), and Ti – xFe – yAl (0<x<40wt.%(36.37at.%)), y=5,10, 15wt.%) have been heat treated to also assess the influence of thermal history on microstructural features such as phase composition and volume fraction. Lastly, a Ti – xMo (0<x<40wt.%(24.96at.%)) compositionally graded specimen was deposited to re-assess the Mo-equivalency nature of W, as well as assess the role of phase separation in microstructural evolution at temperatures above and below the invariant point (~695°C) of the Ti – W binary system.
Date: December 2015
Creator: Gray, Alyn M.
Partner: UNT Libraries

Inner Eye

Description: No Description Available.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: 1952
Creator: Chadwick, Lynn Russell
Partner: UNT College of Visual Arts + Design

Evaporation of Iron-, Nickel-, and Cobalt-Base Alloys at 760 to 980°C in High Vacuums

Description: Report issued by the Oak Ridge National Laboratory discussing the evaporation of alloys in high vacuums. As stated in the introduction, "the investigation encompasses measurements of the evaporation rates, identification of the evaporating elements, and correlation of these measurements to the alloy composition for specimens in both the polished and oxidized conditions" (p. 2). This report includes tables, illustrations, and photographs.
Date: November 1964
Creator: Bourgette, D. T.
Partner: UNT Libraries Government Documents Department

A Comparative Quantitative Study of the Common Elements Found in the Post Oak and Willow

Description: This thesis explores the chemical contents of post oak and willow trees. Samples of each tree are compared to determine the amount of sulfur, phosphorus, potassium, sodium, silicon, iron, aluminum, calcium, magnesium, and manganese in them. Results indicated usefulness of each tree to humans.
Date: August 1939
Creator: Clark, James L.
Partner: UNT Libraries

Oscillator Strengths and Transition Probabilities fro 3288 Lines of Fe I

Description: Report of a homogeneous set of intensity-related data calculated for 3288 spectral lines of Fe I in the region from 2100 to 9900 angstroms. The quantities tabulated in the present monograph include log (g__), log (gf), gf,f,gA, and A. Since recent investigations do not support excitations corrections in the case of Fe I and certain other spectra, the present tabulation incorporates a removal of that normalization function. This recalculation affects the values for all lines whose upper energy levels lie above 46000 cm -1 and should significantly improve the internal consistency of the present data.
Date: March 1968
Creator: Corliss, C. H. & Tech, J. L
Partner: UNT Libraries Government Documents Department