UNT Libraries Government Documents Department - 196 Matching Results

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1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

Description: A reproducible, high-yield synthesis of mono([8]annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono([8]annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 … more
Date: October 1, 1991
Creator: Boussie, T. R.
open access

The addition of disilanes to cumulenes

Description: The syntheses of silicon-containing compounds and the studies of their rearrangements have been active research areas in the Barton research group. Previously, the addition of disilanes to acetylenes was studied in the group and an intramolecular 2S + 2A mechanism has been proposed. In this thesis, the work is focused on the addition of disilanes to cumulenes. The syntheses of the precursors are discussed and the possible mechanisms for their thermal, photochemical and catalytic rearrangements … more
Date: October 8, 1997
Creator: Chen, Y.
open access

The {alpha}-induced thick-target {gamma}-ray yield from light elements

Description: The {alpha}-induced thick-target {gamma}-ray yield from light elements has been measured in the energy range 5.6 MeV {le} E{sub {alpha}} {le} 10 MeV. The {gamma}-ray yield for > 2.1 MeV from thick targets of beryllium, boron nitride, sodium fluoride, magnesium, aluminum and silicon were measured using the {alpha}-particle beam from the Lawrence Berkeley Laboratories 88 in. cyclotron. The elemental yields from this experiment were used to construct the {alpha}-induced direct production {gamma}-r… more
Date: October 1994
Creator: Heaton, R. K.
open access

Aluminum recovery from coal fly ash by high temperature chlorination

Description: A study of aluminum recovery from power plant fly ash by high temperature chlorination was undertaken to demonstrate that fly ash could be a potential source of aluminum, iron and possibly silicon. Magnetic separation of the iron oxide served as a first step to alleviate the iron contamination problem. However, the agglomeration of some iron oxide with alumina and silica made it difficult to completely separate the iron from the fly ash. Further iron separation was achieved by chlorinating the … more
Date: October 1, 1977
Creator: Wijatno, H.
open access

Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys

Description: Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current disser… more
Date: October 15, 2008
Creator: Kalay, Yunus Eren
open access

Analysis of the Interaction of 300-Mev Neutrons with Xenon

Description: Abstract: And investigation of the interactions between 300-Mev neutrons and xenon was made by means of a cloud chamber in a pulsed magnetic field of 21,700 gauss placed in the neutron beam of the 184-inch Berkeley cyclotron. Eighty-seven negative pion events and 257 other stars were analyzed. In addition an experimental check was made on the energy of the incoming neutrons. Classification, identification, and angular and energy distributions of prongs associated with all events are presented. … more
Date: October 17, 1956
Creator: Morris, Richard Herbert, 1928-
open access

ANALYSIS OF THE INTERACTION OF 300-Mev NEUTRONS WITH XENON

Description: An investigation of the interactions between 300-Mev neutrons and xenon was made by means of a cloud chamber in a pulsed magnetic field of 21,700 gauss placed in the neutron beam of the 184-inch Berkeley cyclotron. Eighty-seven negative pion events and 257 other stars were analyzed. In addition an experimental check was made on the energy of the incoming neutrons. Classification, identification, and angular and energy distributions of prongs associated with all events are presented. Interpretat… more
Date: October 17, 1956
Creator: Morris, Richard Herbert.
open access

Anodic oxygen-transfer electrocatalysis at iron-doped lead dioxide electrodes

Description: The research illustrated in this thesis was performed under the guidance of Professor Dennis C. Johnson beginning in March 1987. Chapter 2 concentrates on the development and electrocatalytic properties of iron-doped {beta}-PbO{sub 2} films on noble-metal substrates. Chapter 3 focuses attention on the preparation and characterization of iron-doped {beta}-PbO{sub 2} films on titanium substrates (Fe-PbO{sub 2}/Ti). Chapter 4 discusses anodic evolution of ozone at Fe-PbO{sub 2}/Ti electrodes. Chap… more
Date: October 1, 1994
Creator: Feng, Jianren
open access

THE APPLICATION OF SINGLE PARTICLE AEROSOL MASS SPECTROMETRY FOR THE DETECTION AND IDENTIFICATION OF HIGH EXPLOSIVES AND CHEMICAL WARFARE AGENTS

Description: Single Particle Aerosol Mass Spectrometry (SPAMS) was evaluated as a real-time detection technique for single particles of high explosives. Dual-polarity time-of-flight mass spectra were obtained for samples of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazinane (RDX), and pentaerythritol tetranitrate (PETN); peaks indicative of each compound were identified. Composite explosives, Comp B, Semtex 1A, and Semtex 1H were also analyzed, and peaks due to the explosive components of each sam… more
Date: October 23, 2006
Creator: Martin, A
open access

Application of Soft X-Ray Appearance Potential Spectroscopy to Light Lanthanides, 4d Transition Metals, and Insulators

Description: Evaporated films of La, Ce, Yb, Y, Ag--Mn(5 percent), KCl, MnF$sub 2$, CsCl and LaF$sub 3$ were studied using the soft x-ray appearance potential spectroscopy (SXAPS) technique. Studies were also made of bulk polycrystalline samples of Y, Zr, Nb, and Mo. The results are discussed in terms of existing SXAPS theories. Several similarities between soft x-ray absorption (SXA) data and the SXAPS results are discussed, and it is shown that the SXA data can aid in the interpretation of SXAPS spectra w… more
Date: October 1, 1975
Creator: Smith, R. J.
open access

Application of Ultrasonic Guided Waves to the Characterization of Texture in Metal Sheets of Cubic and Hexagonal Crystallites

Description: Ultrasonic techniques have recently been applied to the texture characterization in polycrystalline aggregates of hexagonal crystals. The basis of this application lies in the relations between the elastic constants {bar C}{sub ij} of the aggregates, which can be inferred from ultrasonic wave velocity measurements, and the orientation distribution coefficients. This communication present such relations for aggregates which possess orthotopic material symmetry and hexagonal crystal symmetry for … more
Date: October 8, 1990
Creator: Li, Yan
open access

Applications of a single-molecule detection in early disease diagnosis and enzymatic reaction study

Description: Various single-molecule techniques were utilized for ultra-sensitive early diagnosis of viral DNA and antigen and basic mechanism study of enzymatic reactions. DNA of human papilloma virus (HPV) served as the screening target in a flow system. Alexa Fluor 532 (AF532) labeled single-stranded DNA probes were hybridized to the target HPV-16 DNA in solution. The individual hybridized molecules were imaged with an intensified charge-coupled device (ICCD) in two ways. In the single-color mode, target… more
Date: October 15, 2008
Creator: Li, Jiangwei
open access

Atom Probe Field Ion Microscope

Description: This report addresses the design and performance of the atom probe field ion microscope.
Date: October 31, 1971
Creator: Stolt, K. G.
open access

Authenticated group Diffie-Hellman key exchange: theory and practice

Description: Authenticated two-party Diffie-Hellman key exchange allows two principals A and B, communicating over a public network, and each holding a pair of matching public/private keys to agree on a session key. Protocols designed to deal with this problem ensure A (B resp.)that no other principals aside from B (A resp.) can learn any information about this value. These protocols additionally often ensure A and B that their respective partner has actually computed the shared secret value. A natural exte… more
Date: October 3, 2002
Creator: Chevassut, Olivier
open access

B-tagging and the search for neutral supersymmetric Higgs bosons at D0

Description: A search for neutral supersymmetric Higgs bosons and work relating to the improvement of the b-tagging and trigger capabilities at the D0 detector during Run II of the Fermilab Tevatron collider is presented. The search for evidence of the Higgs sector in the Standard Model (SM) and supersymmetric extensions of the SM are a high priority for the D0 collaboration, and b-tagging and good triggers are a vital component of these searches. The development and commissioning of the first triggers at D… more
Date: October 1, 2006
Creator: Scanlon, Tim
open access

Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

Description: A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an ide… more
Date: October 1, 1996
Creator: Bennecke, William M.
open access

Broadband Excitation in Nuclear Magnetic Resonance

Description: Theoretical methods for designing sequences of radio frequency (rf) radiation pulses for broadband excitation of spin systems in nuclear magnetic resonance (NMR) are described. The sequences excite spins uniformly over large ranges of resonant frequencies arising from static magnetic field inhomogeneity, chemical shift differences, or spin couplings, or over large ranges of rf field amplitudes. Specific sequences for creating a population inversion or transverse magnetization are derived and de… more
Date: October 1, 1984
Creator: Tycko, R.
open access

Capacity Factors in the Performance of Perforated Plate Distillation Columns

Description: From abstract: "A study of factors affecting the vapor handling capacity of perforated plate liquid-vapor contacting columns. Vapor phase pressure drop across plates, liquid entrainment upward from plate to plate, and plate stability were investigated as functions of operational and geometric column parameters."
Date: October 1954
Creator: Hunt, Charles d'Ancona, 1924-
open access

Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

Description: Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu{sub 2}O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease wit… more
Date: October 1, 1994
Creator: Jernigan, G. G.
open access

Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California

Description: This document contains information about the characterization and application of microearthquake clusters and fault zone dynamics. Topics discussed include: Seismological studies; fault-zone dynamics; periodic recurrence; scaling of microearthquakes to large earthquakes; implications of fault mechanics and seismic hazards; and wave propagation and temporal changes.
Date: October 1, 1995
Creator: Nadeau, R. M.
open access

Characterization and refinement of carbide coating formation rates and dissolution kinetics in the Ta-C system

Description: The interaction between carbide coating formation rates and dissolution kinetics in the tantalum-carbon system was investigated. The research was driven by the need to characterize carbide coating formation rates. The characterization of the carbide coating formation rates was required to engineer an optimum processing scheme for the fabrication of the ultracorrosion-resistant composite, carbon-saturated tantalum. A packed-bed carburization process was successfully engineered and employed. The … more
Date: October 1, 1996
Creator: Rodriguez, P.J.
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