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Analysis of Lid Tank Neutron Data for Lead and Iron

Description: Abstract: An analysis of the lid tank neutron data for Pb-H2O and Fe-H2O is made. "Effective" fast neutron cross sections for the metals are obtained. This is based on the "one collision theory" of shielding. Values are 3.4 barns for Pb and 2.0 barns for Fe. These compare very well with those obtained by Albert and Welton based on other lid tank data and another method of calculation.
Date: January 5, 1951
Creator: Podgor, S.
Partner: UNT Libraries Government Documents Department

Carbon 14 from Lead Nitrate

Description: Report describing the production of carbon 14 from Pb(NO3)2 in the Oak Ridge Nuclear Reactor via the reaction N14 (n.p.) C14.
Date: 1949
Creator: Goodman, Martin R. & Longacre, Andrew, 1904-
Partner: UNT Libraries Government Documents Department

Transformation of Pb(II) from Cerrusite to Chloropyromorphite in the Presence of Hydroxyapatite under Varying Conditions of pH

Description: Cerrusite (PbC03) is soluble under acidic conditions and considered to be a highly bioavailable soil Pb species. In this study, synthetic cerrusite and hydroxyapatite [Ca5(P04)30H] were reacted under constant and dynamic pH conditions with various P/Pb molar ratios in an attempt to evaluate the effect of reaction kinetics on the formation of chloropyromorphite (Pb5(P04)3Cl) and solubilization of Pb. Under constant pH conditions, dissolution rates of both cerrusite and apatite were rapid when pH was low. Complete conversion of Pb from cerrusite to chloropyromorphite occurred within 60 tin at pH 4 and below when the amount of phosphate in the added apatite was stoichoimetrically equal to that needed to transform all added Pb into chloropyromorphite. The concentration of soluble Pb depended upon the volubility of chloropyromorphite. The dissolution rates of apatite and cerrusite decreased with increasing pH, and the transformation was incomplete at pH 5 and above in the 60 rnin reaction period. The soluble Pb level, therefore, was determined by the volubility of cerrusite. In the dynamic pH system which simulated the gastrointestinal tract (GI tract) system, a complete transformation of Pb from cerrusite to chloropyromorphite was achieved due to the complete dissolution of apatite and cerrusite at the initial low pHs. Chloropyromorphite was the exclusive reaction product in both constant and dynamic pH systems as indicated by XRD analysis. The differences in transformation rate and the control of Pb volubility between the reactions occurring in constant and dynamic pH systems indicate the significance of kinetics in controlling the bioavailability of Pb and the potential for the reaction to occur during ingestion.
Date: October 14, 1998
Creator: Ryan, J.A. & Zhang, P.
Partner: UNT Libraries Government Documents Department

2004 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

Description: Section 313 of Emergency Planning and Community Right-to-Know Act (EPCRA) specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. For reporting year 2004, Los Alamos National Laboratory (LANL or the Laboratory) submitted Form R reports for lead compounds, nitric acid, and nitrate compounds as required under the EPCRA Section 313. No other EPCRA Section 313 chemicals were used in 2004 above the reportable thresholds. This document provides a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2004, as well as background information about data included on the Form R reports.
Date: January 15, 2006
Creator: Stockton, M.
Partner: UNT Libraries Government Documents Department

2006 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

Description: For reporting year 2006, Los Alamos National Laboratory (LANL or the Laboratory) submitted Form R reports for lead as required under the Emergency Planning and Community Right-to-Know Act (EPCRA) Section 313. No other EPCRA Section 313 chemicals were used in 2006 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2006, as well as to provide background information about data included on the Form R reports. Section 313 of EPCRA specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. In 1999, EPA promulgated a final rule on persistent bioaccumulative toxics (PBTs). This rule added several chemicals to the EPCRA Section 313 list of toxic chemicals and established lower reporting thresholds for these and other PBT chemicals that were already reportable. These lower thresholds became applicable in reporting year 2000. In 2001, EPA expanded the PBT rule to include a lower reporting threshold for lead and lead compounds. Facilities that manufacture, process, or otherwise use more than 100 lb of lead or lead compounds must submit a Form R.
Date: December 12, 2007
Creator: Ecology and Air Quality Group & Hinojosa, Hector
Partner: UNT Libraries Government Documents Department

2008 Toxic Chemical Release Inventory 2008 Toxic Chemical Release Inventory Community Right-to-Know Act of 1986, Title III, Section 313

Description: For reporting year 2008, Los Alamos National Laboratory (LANL) submitted a Form R report for lead as required under the Emergency Planning and Community Right-to- Know Act (EPCRA) Section 313. No other EPCRA Section 313 chemicals were used in 2008 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2008, as well as to provide background information about data included on the Form R reports. Section 313 of EPCRA specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. In 1999, EPA promulgated a final rule on persistent bioaccumulative toxics (PBTs). This rule added several chemicals to the EPCRA Section 313 list of toxic chemicals and established lower reporting thresholds for these and other PBT chemicals that were already reportable. These lower thresholds became applicable in reporting year 2000. In 2001, EPA expanded the PBT rule to include a lower reporting threshold for lead and lead compounds. Facilities that manufacture, process, or otherwise use more than 100 lb of lead or lead compounds must submit a Form R.
Date: October 1, 2009
Creator: Group, Ecology and Air Quality
Partner: UNT Libraries Government Documents Department

Synthesis of novel precursors for PMN powders and the thin films obtained from them

Description: Sol-gel processing has been widely used in the preparation of lead zirconate titanate (PZT) thin films. The authors have applied this methodology to the formation of lead magnesium niobate (PMN) spin-cast deposited thin films. Since there is a limited number of soluble, commercially available compounds, the authors have recently synthesized a series of novel metal alkoxides for use as precursors for generation of PMN thin films and powders. The process for generation of the perovskite phase of these PMN powders and films are reported.
Date: March 1, 1995
Creator: Boyle, T.J.; Dimos, D.B. & Moore, G.J.
Partner: UNT Libraries Government Documents Department

The Kernel Polynomial Method for non-orthogonal electronic structure calculations

Description: The Kernel Polynomial Method (KPM) has been successfully applied to tight-binding electronic structure calculations as an O(N) method. Here we extend this method to nonorthogonal basis sets with a sparse overlap matrix S and a sparse Hamiltonian H. Since the KPM method utilizes matrix vector multiplications it is necessary to apply S{sup -1} H onto a vector. The multiplication of S{sup -1} is performed using a preconditioned conjugate gradient method and does not involve the explicit inversion of S. Hence the method scales the same way as the original KPM method, i.e. O(N), although there is an overhead due to the additional conjugate gradient part. We show an application of this method to defects in a titanate/platinum interface and to a large scale electronic structure calculation of amorphous diamond.
Date: October 1, 1996
Creator: Roeder, H.; Silver, R.N.; Kress, J.D. & Landrum, G.A.
Partner: UNT Libraries Government Documents Department

Lattice effect in perovskite and pyrochlore CMR materials

Description: Colossal magnetoresistance (CMR) in doped La manganite thin films (La{sub 1-x}M{sub x}MnO{sub 3}, where M = divalent ion, either Ca or Pb) has been shown to result in a factor of 10{sup 6} suppression of the resistance. The driving force for the CMR transition is thought to be the double-exchange interaction. Many studies of both the crystal structure and the local structure of the La{sub 1-x}M{sub x}MnO{sub 3} (M = Ca, Sr, Ba, Pb) system have now been carried out. As expected, these systems all show a strong coupling of the lattice to the CMR transition. On the other hand, neutron diffraction and x-ray absorption for the Tl{sub 2}Mn{sub 2}O{sub 7} pyrochlore, which also exhibits CMR, shows no deviations from ideal stoichiometry, mixed valency, or Jahn-Teller distortions of the MnO{sub 6} octahedron. We present results of crystallographic and local structural studies of these two important classes of CMR materials, compare the differences in structural response, and discuss the implications of these findings to our understanding of these materials.
Date: September 1997
Creator: Kwei, G. H.; Argyriou, D. N.; Lawson, A. C.; Neumeier, J. J.; Thompson, J. D.; Billinge, S. J. L. et al.
Partner: UNT Libraries Government Documents Department

Chemically prepared lead magnesium niobate dielectrics

Description: A chemical solution powder synthesis technique has been developed that produces first, uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions. Chem-prep PMN dielectrics with peak dielectric constants greater than 22,000 and polarizations in excess of 29 {micro}C/cm{sup 2} were obtained for 1,100 C firing treatments. Substantial decreases in dielectric constant and polarization were measured for chemically prepared PMN ceramics fired at lower temperatures, consistent with previous work on mixed oxide materials.
Date: November 1, 1998
Creator: Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R. & Goy, D.M.
Partner: UNT Libraries Government Documents Department

Optical properties of epitaxial PLT thin films

Description: Metalorganic chemical vapor deposition was used to prepare epitaxial or highly oriented PLT (Pb{sub 1-x}La{sub x}TiO{sub 3}) thin films with x = 0.21-0.34. The growth of PLT films resulted in 3-D epitaxial heterostructures on a (100) surface of both MgO and KTaO{sub 3} substrates. The PLT film grown on a KTaO{sub 3} (100) substrate has a significantly lower minimum channeling yield compared to that grown on the MgO (100) substrate because of the smaller lattice mismatch associated with KTaO{sub 3}. Thickness and refractive indices at 435-1523 nm were measured by prism coupling. Measured film thickness of 570 nm was in good agreement with that obtained from RBS. Refractive index of the PLT film is smaller than that of PbTiO{sub 3}, and its difference at {lambda} = 632.8 nm is about 2.5%. Dispersion of the refractive index was well fitted by a Sellmeier dispersion formula.
Date: January 1, 1996
Creator: Kim, Y.; Erbil, A.; Boatner, L.A.; Steingart, L.; Mensah, T. & Hiamang, S.
Partner: UNT Libraries Government Documents Department

Lead-free electric matches.

Description: Electric matches are used in pyrotechnics to initiate devices electrically rather than by burning fuses. Fuses have the disadvantage of burning with a long delay before igniting a pyrotechnic device, while electric matches can instantaneously fire a device at a user's command. In addition, electric matches can be fired remotely at a safe distance. Unfortunately, most current commercial electric match compositions contain lead as thiocyanate, nitroresorcinate or tetroxide, which when burned, produces lead-containing smoke. This lead pollutant presents environmental exposure problems to cast, crew, and audience. The reason that these lead containing compounds are used as electric match compositions is that these mixtures have the required thermal stability, yet are simultaneously able to be initiated reliably by a very small thermal stimulus. A possible alternative to lead-containing compounds is nanoscale thermite materials (metastable intermolecular composites or MIC). These superthermite materials can be formulated to be extremely spark sensitive with tunable reaction rate and yield high temperature products. We have formulated and manufactured lead-free electric matches based on nanoscale Al/MoO{sub 3} mixtures. We have determined that these matches fire reliably and to consistently ignite a sample of black powder. Initial safety, ageing and performance results are presented in this paper.
Date: January 1, 2002
Creator: Son, S. F. (Steven F.); Hiskey, M. A. (Michael A.); Naud, D. (Darren); Busse, J. R. (James R.) & Asay, B. W. (Blaine W.)
Partner: UNT Libraries Government Documents Department

Ultrafast Photovoltaic Response in Ferroelectric Nanolayers

Description: We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric PbTiO3 via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering to visualize atomic displacements on femtosecond timescales, photoinduced changes in the unit-cell tetragonality are observed. These are driven by the motion of photogenerated free charges within the ferroelectric and can be simply explained by a model including both shift and screening currents, associated with the displacement of electrons first antiparallel to and then parallel to the ferroelectric polarization direction.
Date: February 15, 2012
Creator: Daranciang, Dan
Partner: UNT Libraries Government Documents Department

MEASUREMENTS THROUGH A HOT CELL WINDOW USING OPTICAL TOOLING

Description: S>Optical tooling has been evaluated for the measurement of physical dimensions of radioactive parts through hot cell windows. Instruments were set up outside of a four foot thick lead glass window and by means of a grid plate which had been accurately scribed, a ''contour map'' or calibration chart of the window variations was recorded. Although the window was not specially selected, the readings were within 1.0% of the true dimension without using correction factors. One of the calibration chart with the window reduced the error to plus or minus 0.1%. The method is considered feasible and sufficiently fast for a wide variety of hot cell measurements. A pin point light source is suggested as a simple check for selective assembly of lead glass laminates during manufacture of hot cell windows to provide control of optical properties. (auth)
Date: July 18, 1958
Creator: Abbatiello, A.A.
Partner: UNT Libraries Government Documents Department

THE EFFECTS OF REACTOR IRRADIATION ON THE THERMOELECTRIC PROPERTIES OF LEAD AND BISMUTH TELLURIDES

Description: Commercially available specimens of polycrystalline nand p-type lead telluride and n- and p-type bismuth telluride were irradiated in the Engineering Test Reactor. Total integrated flux times of 1.5 x 10/sup 20/ neutrons/cm/sup 2/ (thermal) and 1.6 x 10/sup 19/ neutrons/cm/sup 2/ (fast, i.e., for neutrons having energies greater than 1 (Mev) were accumulated by the specimens during irradiation. The specimen temperature during irradiation was 60 plus or minus 20 deg C. The effects of the irradiation on the thermoelectrical properties of these materials were found to be due almost entirely to fast neutrons insofar as most of the damage is healed during heat treatment. Increases in the electrical resistivity for irradiated n type PbTe and Bi/sub 2/Te/sub 3/ were found to anneal at temperatures below 200 deg C. Measurements of the electrical resistivity and Seebeck coefficient as a function of temperature for irradiated and unirradiated samples cut from the same ingot are given for all materials except p type PbTe. For the latter sample only the measurements of the Seebeck coefficient are given. (auth)
Date: April 1, 1960
Creator: Corelli, J. C. & Frost, R. T.
Partner: UNT Libraries Government Documents Department

Investigation of poling processor, charge trapping and preservation - some ferroelectric and polymeric material. Final report, July 1, 1984--June 20, 1990

Description: A single crystalline (Yttrium stabilized) Zirconia was extensively studied in order to get insight into the charge transport process in Zirconia as compared to other crystalline samples. One thing examined was the effect of crystalline-orientation charge retention on the electret formation discs. The authors did not find any significant difference in the electret formation or retention on cutting the crystal in different orientations. They did, however, notice and collect data on the increase of the charge density and the half life when the sample thickness was increased. They are trying to correlate this with their theory developed for the charge retention and relaxation for the two different mechanisms of monocharge and bipolar charge retention. They also examined the increase in the relaxation time by storage at colder temperature and drier atmosphere. The result was an exponential increase of the half life with the fall of temperature as expected. They began investigating different new materials, all obtained from single crystalline structure. Some new materials like deuterated triglycine fluoroberyliate, (TGA) etc., were found to have much lower insulation property to be able to retain the charges. On the other hand the single crystalline samples of Lithium Niobate and lead zirconium titanate were found to be much better than the single crystal-zironia.
Date: September 1, 1997
Partner: UNT Libraries Government Documents Department

Processing of PbTiO{sub 3} and Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} thin films by novel single-solid-source metalorganic chemical vapor deposition

Description: Ferroelectric PbTiO{sub 3} (PT) and Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films have been deposited on (100) MgO and (111) Pt/SiO{sub 2}/(100)Si substrates by using a novel single-solid-source metalorganic chemical vapor deposition (MOCVD) technique. The new technique uses a powder delivery system to deliver the mixed precursor powders directly into a hot vaporizer from room temperature, therefore, avoiding any problems associated with polymerization or decomposition of the precursors before evaporation. The technique simplifies MOCVD processing significantly and can improve process reliability and reproducibility. The deposited PT and PZT films have a perovskite structure and are highly oriented with respect to the substrate. With improvement of process control, systematic studies of film evolution under various growth conditions have been carried out. Effects of substrate, substrate temperature, system vacuum, and precursor ratios in the mixture on film microstructure and properties will be presented in this paper.
Date: June 1, 1997
Creator: Lu, P.; Li, H.; Sun, S. & Tuttle, B.
Partner: UNT Libraries Government Documents Department

Synthesis and regeneration of lead (IV) acetate

Description: Lead acetate [Pb(O{sub 2}CMe){sub 4}] was easily synthesized from a warm solution of Pb{sub 3}O{sub 4}, HO{sub 2}CMe and O(OCMe){sub 2} following literature preparations when the appropriate measures to minimize water contamination were followed. Furthermore, Pb(O{sub 2}CMe){sub 4} which has been decomposed (evidenced by the appearance of a purple color due to oxidation) can be regenerated using a similar preparatory route. Introduction of Pb(O{sub 2}CMe){sub 4} from the two routes outlined above into the IMO process for production of PZT thin films gave films with comparable ferroelectric properties to commercially available Pb(O{sub 2}CMe){sub 4} precursors. However, the freshly synthesized material yields PZT films with better properties compared to the recycled material.
Date: November 1, 1996
Creator: Boyle, T.J.; Al-Shareef, H.N. & Moore, G.J.
Partner: UNT Libraries Government Documents Department

Physics in the fast lane: rotors, fast ions and mobile fermions

Description: Dynamic disorder in the high-temperature solid phases of the Zintl compounds CsPb and NaSn is characterized by. fast orientational motions of the polyanions and coupled motions of the cations Melting is characterized by slow translational motions of the centers of mass of the polyanions. The dynamic behavior of the ions is associated with dramatic increases in electrical conductivity characteristic of the behavior expected of a mixed conductor.
Date: September 1, 1996
Creator: Price, D.L. & Saboungi, M.-L.
Partner: UNT Libraries Government Documents Department

Research in chemical kinetics. Progress report, July 20, 1988--August 30, 1989

Description: A major aspect of our research over the past decade under this contract has been the application of radioisotopes generated by nuclear reactions for the study of various kinetic mechanisms. Two general theoretical concepts have been explored in detail by this technique: (a) The addition of halogen atoms to olefins, which have been described for fifty years by the phrase {open_quotes}anti-Markownikoff{close_quotes} to indicate that the preference for one or the other end of an unsymmetric olefin is opposite to that ({open_quotes}Markownikoff addition{close_quotes}) for hydrogen halide addition. (b) The redistribution of internal energy within a molecule after an energetic addition reaction, for which the usual assumption is rapid equilibration into all available degrees of freedom, as calculated by the Rice-Rarnsperger-Kassel-Marcus (RRKM) model. In both instances, significant results have been obtained which expand the overall view of each of these two concepts.
Date: September 1, 1996
Creator: Rowland, F.S.
Partner: UNT Libraries Government Documents Department

Evaluation of field enforced antiferroelectric to ferroelectric phase transition dielectrics and relaxor ferroelectrics for pulse discharge capacitors

Description: Discharge capacitors were designed based on materials with antiferroelectric (AFE) to ferroelectric (FE) field enforced transitions that had 10 times the capacitance of relaxor ferroelectric or state of the art BaTiO{sub 3} materials in the voltage range of interest. Nonlinear RLC circuit analysis was used to show that the AFE to FE materials have potentially more than 2 times the peak discharge current density capability of the BaTiO{sub 3} or lead magnesium niobate (PMN) based relaxor materials. Both lead lanthanum zirconium tin titanate (PLZST) AFE to FE field enforced phase transition materials and PMN based relaxor materials were fabricated and characterized for Sandia`s pulse discharge capacitor applications. An outstanding feature of the PLZST materials is that there are high field regimes where the dielectric constant increases substantially, by a factor of 20 or more, with applied field. Specifically, these materials have a low field dielectric constant of 1,000, but an effective dielectric constant of 23,000 in the electric field range corresponding to the FE to AFE transition during discharge. Lead magnesium niobate (PMN) based relaxor materials were also investigated in this project because of their high dielectric constants. While the PMN based ceramics had a low field dielectric constant of 25,000, at a field corresponding to half the charging voltage, approximately 13 kV/cm, the dielectric constant decreases to approximately 7,500.
Date: September 1, 1997
Creator: Hoover, B.D.; Tuttle, B.A.; Olson, W.R.; Goy, D.M.; Brooks, R.A. & King, C.F.
Partner: UNT Libraries Government Documents Department