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(6)Li, (7)Li Nuclear Magnetic Resonance Investigation of Lithium Coordination in Binary Phosphate Glasses (open access)

(6)Li, (7)Li Nuclear Magnetic Resonance Investigation of Lithium Coordination in Binary Phosphate Glasses

{sup 6}Li and {sup 7}Li solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the local coordination environment of lithium in a series of xLi{sub 2}O {center_dot} (1-x)P{sub 2}O{sub 5} glasses, where 0.05 {le} x {le} 0.55. Both the {sup 6}Li and {sup 7}Li show chemical shift variations with changes in the Li{sub 2}O concentration, but the observed {sup 6}Li NMR chemical shifts closely approximate the true isotropic chemical shift and can provide a measure of the lithium bonding environment. The {sup 6}Li NMR results indicate that in this series of lithium phosphate glasses the Li atoms have an average coordination between four and five. The results for the metaphosphate glass agree with the coordination number and range of chemical shifts observed for crystalline LiPO{sub 3}. An increase in the {sup 6}Li NMR chemical shift with increasing Li{sub 2}O content was observed for the entire concentration range investigated, correlating with increased cross-linking of the phosphate tetrahedral network by O-Li-O bridges. The {sup 6}Li chemical shifts were also observed to vary monotonically through the anomalous glass transition temperature (T{sub g}) minimum. This continuous chemical shift variation shows that abrupt changes in the Li coordination …
Date: February 8, 1999
Creator: Alam, T.M.; Boyle, T.J.; Brow, R.K. & Conzone, S.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 99, No. 282, Ed. 1 Monday, February 8, 1999 (open access)

Altus Times (Altus, Okla.), Vol. 99, No. 282, Ed. 1 Monday, February 8, 1999

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: February 8, 1999
Creator: Cole, Carol
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Alvin Sun (Alvin, Tex.), Vol. 108, No. 54, Ed. 1 Monday, February 8, 1999 (open access)

The Alvin Sun (Alvin, Tex.), Vol. 108, No. 54, Ed. 1 Monday, February 8, 1999

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: February 8, 1999
Creator: Schwind, Jim & Looby, Edward
Object Type: Newspaper
System: The Portal to Texas History
Application of computational fluid dynamics (CFD) to nuclear applications. (open access)

Application of computational fluid dynamics (CFD) to nuclear applications.

Detailed analysis of a quarter channel was performed using VIPRE and CFX. Results show that VIPRE and CFX agree closely in both cross-sectionally averaged axial temperature and cross-sectionally averaged axial velocity profiles. Detailed temperature distributions in the radial direction over 1mm from the clad surface towards the center of the channel were calculated using CFX, showing significant local variation. This information can be used for example, to determine if this temperature will lead to bubble nucleation. Quarter subassembly calculations were made with both VIPRE and STAR-CD. Comparison between the solutions show that the two codes yield very similar solutions under comparable conditions. However, the STAR-CD CFD calculation provides the analyst with much more detailed flow and temperature distributions than can be predicted by a one-dimensional code such as VIPRE. In addition, a 60 million cell one-eighth reactor core calculation was made using STAR-CD. This analysis showed the importance of accurately predicting the flow and temperature fields in all assemblies simultaneously with modern parallel processing technology, practical turnaround for these types of calculation can be obtained.
Date: February 8, 1999
Creator: Brewster, R. A.; Jonnavithula, S.; Rizwan-Uddin; Rock, D. T.; Weber, D. P. & Wei, T. Y. C.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 86, Ed. 1 Monday, February 8, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 77, No. 86, Ed. 1 Monday, February 8, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: February 8, 1999
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History
Beam tests of the 12 MHz RFQ RIB injector for ATLAS. (open access)

Beam tests of the 12 MHz RFQ RIB injector for ATLAS.

In recent tests without beam, the Argonne 12 MHz split-coaxial radio-frequency quadruple (RFQ) achieved a cw intervane voltage of more than 100 kV, the design operating voltage for the device. This voltage is sufficient for the RFQ to function as the first stage of a RIB injector for the Argonne Tandem Linear Accelerator System (ATLAS). Previously reported beam dynamics calculations for the structure predict longitudinal emittance growth of only a few keV{center_dot}ns for beams of mass 132 and above with transverse emittance of 0.27 {pi} mm{center_dot}mrad (normalized). Such beam quality is not typical of RFQ devices. The work reported here is preparation for tests with beams of mass up to 132. Beam diagnostic stations are being developed to measure the energy gain and beam quality of heavy ions accelerated by the RFQ using the Dynamitron accelerator facility at the ANL Physics Division as the injector. Beam diagnostic development includes provisions for performing the measurements with both a Si charged-particle detector and an electrostatic energy spectrometer system.
Date: February 8, 1999
Creator: Kaye, R. A.
Object Type: Article
System: The UNT Digital Library
Bilinear System Characteristics from Nonlinear Time Series Analysis (open access)

Bilinear System Characteristics from Nonlinear Time Series Analysis

Detection of changes in the resonant frequencies and mode shapes of a system is a fundamental problem in dynamics. This paper describes a time series method of detecting and quantifying changes in these parameters for a ten degree-of-freedom bilinear system excited by narrow band random noise. The method partitions the state space and computes mode frequencies and mode shapes for each region. Different regions of the space may exhibit different mode shapes, allowing diagnosis of stiffness changes at structural discontinuities. The method is useful for detecting changes in the properties of joints in mechanical systems or for detection of damage as the properties of a structure change during use.
Date: February 8, 1999
Creator: Hunter, N.F. Jr.
Object Type: Article
System: The UNT Digital Library
Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada, Revision 0. UPDATED WITH RECORD OF TECHNICAL CHANGE No.1 (open access)

Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada, Revision 0. UPDATED WITH RECORD OF TECHNICAL CHANGE No.1

This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense (FFACO, 1996). The CAIP is a document that provides or references all of the specific information for investigation activities associated with Corrective Action Units (CAUs) or Corrective Action Sites (CASs). According to the FFACO (1996), CASs are sites potentially requiring corrective action(s) and may include solid waste management units or individual disposal or release sites. A CAU consists of one or more CASs grouped together based on geography, technical similarity, or agency responsibility for the purpose of determining corrective actions. This CAIP contains the environmental sample collection objectives and the criteria for conducting site investigation activities at the CAU 321 Area 22 Weather Station Fuel Storage, CAS 22-99-05 Fuel Storage Area. For purposes of this discussion, this site will be referred to as either CAU 321 or the Fuel Storage Area. The Fuel Storage Area is located in Area 22 of the Nevada Test Site (NTS). The NTS is approximately 105 …
Date: February 8, 1999
Creator: /NV, U.S. DOE
Object Type: Report
System: The UNT Digital Library
Damage Identification with Linear Discriminant Operators (open access)

Damage Identification with Linear Discriminant Operators

This paper explores the application of statistical pattern recognition and machine learning techniques to vibration-based damage detection. First, the damage detection process is described in terms of a problem in statistical pattern recognition. Next, a specific example of a statistical-pattern-recognition-based damage detection process using a linear discriminant operator, ''Fisher's Discriminant'', is applied to the problem of identifying structural damage in a physical system. Accelerometer time histories are recorded from sensors attached to the system as that system is excited using a measured input. Linear Prediction Coding (LPC) coefficients are utilized to convert the accelerometer time-series data into multi-dimensional samples representing the resonances of the system during a brief segment of the time series. Fisher's discriminant is then used to find the linear projection of the LPC data distributions that best separates data from undamaged and damaged systems. The method i s applied to data from concrete bridge columns as the columns are progressively damaged. For this case, the method captures a clear distinction between undamaged and damaged vibration profiles. Further, the method assigns a probability of damage that can be used to rank systems in order of priority for inspection.
Date: February 8, 1999
Creator: Farrar, C. R.; Nix, D. A.; Duffey, T. A.; Cornwell, P. J. & Pardoen, G. C.
Object Type: Article
System: The UNT Digital Library
Development of a safety interlock system for the National Ignition Facility optical line replaceable unit transport and handling systems (open access)

Development of a safety interlock system for the National Ignition Facility optical line replaceable unit transport and handling systems

None
Date: February 8, 1999
Creator: Hall, T B
Object Type: Article
System: The UNT Digital Library
Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers (open access)

Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 Gr 55, a carbon steel, or Monel 400. At the present time, Alloy C-22 and A516 G4 55 are favored.
Date: February 8, 1999
Creator: Bedrossian, P.; Estill, J.; Farmer, J.; Hopper, R.; Horn, J.; Huang, J. S. et al.
Object Type: Report
System: The UNT Digital Library
[Documented Email Discussion on TETAC Project at Oakhurst] (open access)

[Documented Email Discussion on TETAC Project at Oakhurst]

A comprehensive email, stakeholders engage in a documented discussion about the Transforming Education Through the Arts Challenge (TETAC) Project at Oakhurst.
Date: February 8, 1999, 1:42 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
Dyson-Schwinger equations: connecting small and large length-scales. (open access)

Dyson-Schwinger equations: connecting small and large length-scales.

The phenomenological application of Dyson-Schwinger equations to the calculation of meson properties observable at TJNAF is illustrated. Particular emphasis is given to the ability of this framework to unify long-range effects constrained by chiral symmetry with short-range effects prescribed by perturbation theory, and interpolate between them.
Date: February 8, 1999
Creator: Roberts, C.
Object Type: Article
System: The UNT Digital Library
Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions (open access)

Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions

We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our analysis includes petroleum use, energy use, and emissions associated with chemicals manufacturing, farming of corn and biomass, ethanol production, and ethanol combustion for ethanol; and petroleum use, energy use, and emissions associated with petroleum recovery, petroleum refining, and gasoline combustion for gasoline. For corn-based ethanol, the key factors in determining energy and emissions impacts include energy and chemical usage intensity of corn farming, energy intensity of the ethanol plant, and the method used to estimate energy and emissions credits for co-products of corn ethanol. The key factors in determining the impacts of cellulosic ethanol are energy and chemical usage intensity of biomass farming, ethanol yield per dry ton of biomass, and electricity credits in cellulosic ethanol plants. The results of our fuel-cycle analysis for fuel ethanol are listed below. Note that, in the first half of this summary, the reductions cited are per-vehicle-mile traveled using the specified ethanol/gasoline blend instead of conventional (not reformulated) gasoline. The second half of the summary …
Date: February 8, 1999
Creator: Saricks, C.; Santini, D. & Wang, M.
Object Type: Report
System: The UNT Digital Library
[Email Correspondence on Synergies Between Oakhurst School and Westat] (open access)

[Email Correspondence on Synergies Between Oakhurst School and Westat]

A nuanced email exchange, offering strategic insights and updates on the collaborative efforts between Oakhurst School and Westat. The correspondence delves into key considerations, progress reports, and shared perspectives, serving as a dynamic record of their strategic alignment.
Date: February 8, 1999, 9:21 a.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Approaching Greenbriar School for Case Study Consideration] (open access)

[Email Exchange on Approaching Greenbriar School for Case Study Consideration]

A documented email exchange outlining the strategic discussions and considerations related to approaching Greenbriar School for potential inclusion as a case study school.
Date: February 8, 1999, 1:51 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Oakhurst School, Westat, and TETAC Project] (open access)

[Email Exchange on Oakhurst School, Westat, and TETAC Project]

A comprehensive email exchange capturing strategic discussions surrounding Oakhurst School, Westat, and the TETAC project.
Date: February 8, 1999, 2:46 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Oakhurst School - Westat Collaboration] (open access)

[Email Exchange on Oakhurst School - Westat Collaboration]

A comprehensive email exchange documenting strategic discussions and collaboration between Oakhurst School and Westat. The conversation provides insights into key considerations, progress updates, and shared perspectives on collaborative initiatives.
Date: February 8, 1999, 2:46 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Team Member Departure and Replacement Candidates - Mitchell Project] (open access)

[Email Exchange on Team Member Departure and Replacement Candidates - Mitchell Project]

A detailed email exchange addressing the departure of a team member and the identification of potential candidates for replacement within the context of the Mitchell project.
Date: February 8, 1999, 12:11 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Workflow, Testing, and Progress - TETAC, NTIEVA, and Participating Schools] (open access)

[Email Exchange on Workflow, Testing, and Progress - TETAC, NTIEVA, and Participating Schools]

A detailed email exchange capturing strategic discussions among individuals involved in TETAC, NTIEVA, and participating schools.
Date: February 8, 1999, 3:08 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
Excitation Methods for Bridge Structures (open access)

Excitation Methods for Bridge Structures

This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.
Date: February 8, 1999
Creator: Farrar, C.R.; Duffy, T.A.; Cornwell, P.J. & Doebling, S.W.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, February 8, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, February 8, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: February 8, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
F. M. E. A. RHIC Cryogenics (open access)

F. M. E. A. RHIC Cryogenics

None
Date: February 8, 1999
Creator: Kane, S>
Object Type: Report
System: The UNT Digital Library

Faculty Recital: 1999-02-08 - UNT Faculty Jazz Sextet

Access: Use of this item is restricted to the UNT Community
Jazz concert performed at the UNT College of Music Kenton Hall.
Date: February 8, 1999
Creator: UNT Faculty Jazz Sextet
Object Type: Sound
System: The UNT Digital Library