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Innovations in the Metallurgy of Lead

Description: From Introduction: "The data reported in this bulletin are largely the result of experiments conducted by the Salt Lake City station of the Bureau of Mines in cooperation with the department of metallurgical research of the University of Utah. The work on the lead is the only one of the phases of the investigations carried on at that station during the years 1914 to 1916."
Date: 1918
Creator: Lyon, Dorsey A. & Ralston, Oliver C.
Partner: UNT Libraries Government Documents Department

A Dithizone Method for the Determination of Lead in Monazite

Description: The following report discusses a method for determining lead in monazite to be used as a basis for geologic age measurements. In order to develop the method it was necessary to eliminate interferences due to the presence of phosphates of thorium and the rare-earth metals.
Date: June 1956
Creator: Powell, R. A. & Kinser, C. A.
Partner: UNT Libraries Government Documents Department

Lead: A Materials Survey

Description: Report issued by the U.S. Bureau of Mines discussing a materials survey conducted on lead. Physicality, history, geology, uses, and locations of lead is presented. This report includes maps, tables, illustrations, and photographs.
Date: 1962
Creator: Callaway, H. M.
Partner: UNT Libraries Government Documents Department

Formation of Pyromorphite in Anglesite-Hydroxyapatite Suspensions Under Varying pH Conditions

Description: Addition of phosphate to lead [Pb(ll)l-cOntarninated soil to immobilize soil Pb by formation of pyromorphite has been proposed as an alternative remediation technique. Lead sulfate (PbS04, anglesite), a Pb-bearing form found in contaminated soils and wastes, was reacted with a synthetic phosphate mineral, hydroxyapa$te [Ca5(PO& OH], under constant pH (PH 2-7) and simulated gastric pH conditions (PH varied from 2 to 7 within 30 rein) to assess the effects of reaction kinetics on the formation rate of chloropyromorphite and the volubility of Pb. Under constant pH condition, complete transformation of anglesite to chloropyromorphite, [Pb5(PO&Cl], was obtained at pH 4 and pH 5. At pH 6 and pH 7, the newly formed chloropyromorphite precipitated on the surface of undissolved apatite, The coverage of the apatite surface may reduce apatite dissolution fate and the transformation rate of Pb from anglesite to"chloropyromorphite. Increasing the P/Pb ratio increased the transformation rate, but anglesite was still present after a' 120-min reaction time. in the dynamic pH system, the added apatite was rapidly dissolved at the initial low pH, and complete transformation of anglesite to chloropyromorphite was obtained within 25 min., The soluble Pb level was controlled by the volubility of chloropyromorphite during the entire reaction process. These results demonstrate the effect of reaction kinetics on the formation rate of chloropyromorphite and the mechanisms controlling the solubilization of Pb in the anglesite-apatite system. Furthermore, they illustrate that a complete transformation of ingested anglesite to chloropyromorphite can be achieved. under gastrointestinal tract pH conditions if sufficient phosphate is provided.
Date: October 14, 1998
Creator: Ryan, J.A. & Zhang, P.
Partner: UNT Libraries Government Documents Department

Lead-Based Paint Poisoning Prevention: Summary of Federal Mandates and Financial Assistance for Reducing Hazards in Housing

Description: This report discusses the federal strategy to reduce childhood exposure to lead-based paint (LBP). The federal Lead-Based Paint Poisoning Prevention Act (LBPPPA), as amended, establishes requirements and authorizes funding for the detection and control of LBP hazards in federally assisted housing.
Date: June 12, 2008
Creator: Schierow, Linda-Jo
Partner: UNT Libraries Government Documents Department

High Temperature Enthalpies of the Lead Halides: Enthalpies and Entropies of Fusion

Description: The objectives of this investigation were: 1. To establish calorimetrically the transition temperature for the orthorhombic to cubic transition exhibited by PbF₂ and to determine the enthalpy of this transition. 2. To determine if the solid-solid phase transitions claimed in the literature for PbCl₂, PbF₂, PbBr₂, and PbI₂ were of thermodynamic importance, and if so, to determine the enthalpies of transition. 3. To determine if the discontinuous thermal expansions reported by Hsu for the lead halides were of thermodynamic importance. 4. To obtain reliable heat content data for the lead halides in both the solid and liquid states.
Date: June 1970
Creator: Linsey, Clarence W.
Partner: UNT Libraries

The Lead Susceptibility of Fuels and Its Dependence on the Chemical Composition

Description: The fact that by the use of tetraethyl lead a number of otherwise unsuitable fuels could be made to meet engine requirements was not sufficiently appreciated. While use of tetraethyl lead is limited, the addition of special leaded fuels that increase the octane number is a requirement for many fuels. In this connection, the extent to which the action of tetraethyl lead through the addition of knock-resistant hydrocarbons to the base gasoline is influenced, is quite important. To the elucidation of this problem and of the storage stability of leaded fuels, the present report is dedicated.
Date: April 1940
Creator: Widmaier, O.
Partner: UNT Libraries Government Documents Department

The Isotopic Composition of Trace Quantities of Lead and Calcium

Description: The following report discusses development of new micro-chemical and micro-mas spectrometric techniques for handling trace quantities of lead. The first two sections of this report summarizes the development and trial application to mineral separates of a granite rock. The third section summarizes similar techniques developed for the determination of calcium, and gives the results of an application of the technique to the determination of the radioactive decay constants of K-40.
Date: 1951
Creator: Patterson, Claire
Partner: UNT Libraries Government Documents Department

Lead Slowing Down Spectrometer Research Plans

Description: The MPACT-funded Lead Slowing Down Spectrometry (LSDS) project has been evaluating the feasibility of using LSDS techniques to assay fissile isotopes in used nuclear fuel assemblies. The approach has the potential to provide considerable improvement in the assay of fissile isotopic masses in fuel assemblies compared to other non-destructive techniques in a direct and independent manner. The LSDS collaborations suggests that the next step to in empirically testing the feasibility is to conduct measurements on fresh fuel assemblies to understand investigate self-attenuation and fresh mixed-oxide (MOX) fuel rodlets so we may betterto understand extraction of masses for 235U and 239Pu. While progressing toward these goals, the collaboration also strongly suggests the continued development of enabling technology such as detector development and algorithm development, thatwhich could provide significant performance benefits.
Date: March 22, 2013
Creator: Warren, Glen A.; Kulisek, Jonathan A.; Gavron, Victor; Danon, Yaron; Weltz, Adam; Harris, Jason et al.
Partner: UNT Libraries Government Documents Department

An Investigation of the Effect of Tetraethyl Lead and Ethyl Nitrite on the Autoignition Characteristics of Isooctane and Triptane

Description: Report presenting an investigation to study the effect of tetraethyl lead, a knock inhibitor, on isooctane. A brief study of ethyl nitrate was also carried out, which demonstrated that it decreased both the delay and critical explosion pressure. Several series of tests were carried out involving different combinations of lead and fuel-air ratio.
Date: June 1950
Creator: Jovellanos, J. U.; Taylor, E. S.; Taylor, C. F. & Leary, W. A.
Partner: UNT Libraries Government Documents Department

In situ measurement of electromigration-induced transient stress in Pb-free Sn-Cu solder joints by synchrotron radiation based X-ray polychromatic microdiffraction

Description: Electromigration-induced hydrostatic elastic stress in Pb-free SnCu solder joints was studied by in situ synchrotron X-ray white beam microdiffraction. The elastic stresses in two different grains with similar crystallographic orientation, one located at the anode end and the other at the cathode end, were analyzed based on the elastic anisotropy of the Beta-Sn crystal structure. The stress in the grain at the cathode end remained constant except for temperature fluctuations, while the compressive stress in the grain at the anode end was built-up as a function of time during electromigration until a steady state was reached. The measured compressive stress gradient between the cathode and the anode is much larger than what is needed to initiate Sn whisker growth. The effective charge number of Beta-Sn derived from the electromigration data is in good agreement with the calculated value.
Date: December 1, 2009
Creator: Chen, Kai; Tamura, Nobumichi; Kunz, Martin; Tu, King-Ning & Lai, Yi-Shao
Partner: UNT Libraries Government Documents Department

Tests of Lead-Bronze Bearings in the DVL Bearing-Testing Machine

Description: "The lead-bronze bearings tested in the DVL machine have proven themselves very sensitive to load changes as in comparison with bearings of light metal. In order to prevent surface injuries and consequently running interruptions, the increase of the load has to be made in small steps with sufficient run-in time between steps. The absence of lead in the running surface, impurities in the alloy (especially iron) and surface irregularities (pores) decreases the load-carrying capacity of the bearing to two or three times that of the static load" (p. 1).
Date: June 1940
Creator: Fischer, G.
Partner: UNT Libraries Government Documents Department

Lead susceptibility of paraffins, cycloparaffins, and olefins

Description: "General relationships for the lead susceptibilities of paraffins, cycloparaffins, and olefins are presented. Methods are described by which the lead response may be estimated for these hydrocarbon classes, whether the lead response is indicated by octane number, critical compression ratio, or indicated mean effective pressure as limited by knock" (p. 1).
Date: May 1943
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department

Effect of sliding velocity on friction properties and endurance life of bonded lead monoxide coatings at temperatures up to 1250 degrees F

Description: Report presenting studies to determine the effect of sliding velocity and ambient temperature on the friction properties and endurance lift of thin lead monoxide coatings bonded to type 440-C martensitic stainless steel. Results regarding the effect of run-in on endurance life are also provided.
Date: May 16, 1958
Creator: Sliney, Harold E.
Partner: UNT Libraries Government Documents Department

Formation of Chloropyromorphite in a Lead-Contaminated Soil Amended with Hydroxyapatite

Description: To confirm conversion of soil Pb to pyromorphite [Pb{sub 5}(PO{sub 4}){sub 3}Cl], a Pb contaminated soil collected adjacent to a historical smelter was reacted with hydroxyapatite in slurries of soil and hydroxyapatite separated by a dialysis membrane and incubated. A crystalline precipitate formed on the dialysis membrane in the slurry systems was identified as chloropyromorphite. Soluble species measured in the soil slurry indicated that dissolution of solid-phase soil Pb was the rate-limiting step for pyromorphite formation. Additionally samples reacted with hydroxyapatite were incubated at field-capacity moisture content. The sequential chemical extraction used to identify species in the field-moist soil incubation experiment showed that hydroxyapatite treatment reduced the first four fractions of extractable Pb and correspondingly increased the recalcitrant extraction residue fraction by 35% of total Pb at 0 d incubation and by 45% after 240 d incubation. the increase in the extraction residue fraction in the 240 d incubation as compared to the 0 d incubation implies that the reaction occurs in the soil but the increase in the hydroxyapatite amended 0 d incubated soil as compared to the control soil illustrates the chemical extraction procedure caused changes in the extractability. Thus, the chemical extraction procedure cannot easily be utilized to confirm changes occurring in the soil as a result of incubation. Extended x-ray absorption fine structure (EXAFS) spectroscopy indicated that the 240 d incubated hydroxyapatite treatment caused a change in the average, local molecular bonding environment of soil Pb. Low-temperature EXAFS spectra (chi data and radial structure functions - RSFs) showed a high degree of similarity between the chemical extraction residue and synthetic pyromorphite. Thus, confirming that the change of soil Pb to pyromorphite is possible by simple amendments of hydroxyapatite to soil.
Date: July 14, 2000
Partner: UNT Libraries Government Documents Department

J/{psi} and {psi}{prime} suppression by comovers in Pb+Pb collisions

Description: Measurements of {psi} and {psi}{prime} production at the CERN SPS are compared to predictions based on a hadronic model of charmonium suppression. Detailed information is presented to facilitate comparison to other analyses. Sensitivity of these conclusions to model parameters is discussed.
Date: November 1996
Creator: Gavin, S. & Vogt, R.
Partner: UNT Libraries Government Documents Department