The MFTF Exception Handling System (open access)

The MFTF Exception Handling System

In the design of large experimental control systems, a major concern is ensuring that operators are quickly alerted to emergency or other exceptional conditions and that they are provided with sufficient information to respond adequately. This paper describes how the MFTF exception handling system satisfies these requirements. Conceptually exceptions are divided into one of two classes. Those which affect command status by producing an abort or suspend condition and those which fall into a softer notification category of report only or operator acknowledgement requirement. Additionally, an operator may choose to accept an exception condition as operational, or turn off monitoring for sensors determined to be malfunctioning. Control panels and displays used in operator response to exceptions are described.
Date: November 12, 1979
Creator: Nowell, D. M. & Bridgeman, G. D.
Object Type: Article
System: The UNT Digital Library
LOFT Vital MG Set transient parameter review (open access)

LOFT Vital MG Set transient parameter review

This report evaluates the performance of the vital MG sets during a worst case load transfer. Evaluation of test data showed: (1) The Vital MG Set withstood the extreme loading; (2) The load can be sustained well in excess of the required time limit; and (3) The transfer perturbation caused the frequency to exceed the limits set by the SDD. The follow up evaluations of the equipment powered by the MG sets demonstrated that the equipment function will not be degraded.
Date: September 12, 1978
Creator: Kranning, A.N.
Object Type: Report
System: The UNT Digital Library
Transportation impacts on the Tennessee highway system proposed monitored retrievable storage (open access)

Transportation impacts on the Tennessee highway system proposed monitored retrievable storage

The issue of the transport of spent fuels to the proposed monitored retrievable storage facility in Tennessee is discussed. Relevant issues include the ability of the roads and bridges on the transport routes to handle the weight of the trucks. (CBS)
Date: December 12, 1985
Creator: Cobble, C.
Object Type: Report
System: The UNT Digital Library
MFTF 230 kV pulsed power substation (open access)

MFTF 230 kV pulsed power substation

The Mirror Fusion Test Facility (MFTF) currently under construction at the Lawrence Livermore Laboratory includes a Sustaining Neutral Beam Power Supply System (SNBPSS) consisting of 24 power-supply sets. The System will operate in long pulses (initially .5 seconds and eventually 30 seconds) at high power (200 MW), which will necessitate a large source of ac power. To meet this requirement, a new 230-kV substation is also being built at LLL. The constraints of cost, equipment protection, short operating lifetime (10 years), and reliability dictated a unique substation design. Its unusual features include provisions for fast fault detection and tripping, a capability for limiting ground fault current, low impedance, and economical design.
Date: November 12, 1979
Creator: Wilson, J. H.
Object Type: Article
System: The UNT Digital Library
No pain-no gain: The complex art of soft x-ray laser target design and analysis (open access)

No pain-no gain: The complex art of soft x-ray laser target design and analysis

We review our methodologies in the design and analysis of soft x-ray laser experiments. We convolve large-scale 2-D hydro code output with detailed atomic data bases in a kinetics code with 1-D or 2-D line transfer. The time and space dependent level population data is then post processed further with a beam transport code, including refraction, to predict actual experimental results. While mysteries do remain, we present many examples that show how this complex modeling procedure is crucial in explaining experimental results. 23 refs., 8 figs., 1 tab.
Date: January 12, 1988
Creator: Rosen, M. D.; London, R. A.; Hagelstein, P. L.; Maxon, M. S.; Eder, D. C.; Whitten, B. L. et al.
Object Type: Article
System: The UNT Digital Library
MFTF plasma diagnostics data acquisition system (open access)

MFTF plasma diagnostics data acquisition system

The initial goal of the Data Acquisition System (DAS) is to control 11 instruments chosen as the startup diagnostic set and to collect, process, and display the data that these instruments produce. These instruments are described in a paper by Stan Thomas, et. al. entitled ''MFTF Plasma Diagnostics System.'' The DAS must be modular and flexible enough to allow upgrades in the quantity of data taken by an instrument, and also to allow new instruments to be added to the system. This is particularly necessary to support a research project where needs and requirements may change rapidly as a result of experimental findings. Typically, the startup configuration of the diagnostic instruments will contain only a fraction of the planned detectors, and produce approximately one half the data that the expanded version is designed to generate. Expansion of the system will occur in fiscal year 1982.
Date: November 12, 1979
Creator: Davis, G.E. & Coffield, F.E.
Object Type: Article
System: The UNT Digital Library
Status of tandem mirror theory (open access)

Status of tandem mirror theory

This report contains the text and slides used for the review talk on tandem mirror theory presented at the meeting of the Division of Plasma Physics, A.P.S., Boston, MA, November 12-16, 1979. Topics covered include classical confinement, equilibria, MHD- and micro-stability, radial transport, and thermal barriers.
Date: December 12, 1979
Creator: Baldwin, D.E.
Object Type: Article
System: The UNT Digital Library
Oxidation of alloys targeted for advanced steam turbines (open access)

Oxidation of alloys targeted for advanced steam turbines

Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760°C. This research examines the steamside oxidation of alloys for use in USC systems, with emphasis placed on applications in high- and intermediate-pressure turbines.
Date: March 12, 2006
Creator: Holcomb, G. R.; Covino, B. S., Jr.; Bullard, S. J.; Ziomek-Moroz, M. & Alman, D. E.
Object Type: Article
System: The UNT Digital Library
Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt (open access)

Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt

The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. This is significantly smaller than the value of {approx} 1 {angstrom}{sup -1} found when the separation is changed by changing the length of the alkanethiol molecules. Calculations indicate that for isolated dithiol molecules S-bonded to hollow sites, the junction conductance does not vary significantly as a function of molecular tilt. The impact of S-Au bonding on SAM conductance is discussed.
Date: November 12, 2007
Creator: Mulleregan, Alice; Qi, Yabing; Ratera, Imma; Park, Jeong Y.; Ashby, Paul D.; Quek, Su Ying et al.
Object Type: Article
System: The UNT Digital Library
New Pump and Treat Facility Remedial Action Work Plan For Test Area North Final Groundwater Remediation, Operable Unit 1-07B (open access)

New Pump and Treat Facility Remedial Action Work Plan For Test Area North Final Groundwater Remediation, Operable Unit 1-07B

This remedial action work plan identifies the approach and requirements for implementing the medial zone remedial action for Test Area North, Operable Unit 1-07B, at the Idaho National Laboratory. This plan details the management approach for the construction and operation of the New Pump and Treat Facility (NPTF). As identified in the remediatial design/remedial action scope of work, a separate remedial design/remedial action work plan will be prepared for each remedial component of the Operable Unit 1-07B remedial action.
Date: June 12, 2007
Creator: Nelson, L. O.
Object Type: Report
System: The UNT Digital Library
"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study" (open access)

"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study"

None
Date: May 12, 2006
Creator: McConnell, S
Object Type: Article
System: The UNT Digital Library
Compact Proton Accelerator for Cancer Therapy (open access)

Compact Proton Accelerator for Cancer Therapy

An investigation is being made into the feasibility of making a compact proton dielectric wall (DWA) accelerator for medical radiation treatment based on the high gradient insulation (HGI) technology. A small plasma device is used for the proton source. Using only electric focusing fields for transporting and focusing the beam on the patient, the compact DWA proton accelerator m system can deliver wide and independent variable ranges of beam currents, energies and spot sizes.
Date: June 12, 2007
Creator: Chen, Y. & Paul, A. C.
Object Type: Article
System: The UNT Digital Library
TRITIUM EFFECTS ON DYNAMIC MECHANICAL PROPERTIES OF POLYMERIC MATERIALS (open access)

TRITIUM EFFECTS ON DYNAMIC MECHANICAL PROPERTIES OF POLYMERIC MATERIALS

Dynamic mechanical analysis has been used to characterize the effects of tritium gas (initially 1 atm. pressure, ambient temperature) exposure over times up to 2.3 years on several thermoplastics-ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), and Vespel{reg_sign} polyimide, and on several formulations of elastomers based on ethylene propylene diene monomer (EPDM). Tritium exposure stiffened the elastic modulus of UHMW-PE up to about 1 year and then softened it, and reduced the viscous response monotonically with time. PTFE initially stiffened, however the samples became too weak to handle after nine months exposure. The dynamic properties of Vespel{reg_sign} were not affected. The glass transition temperature of the EPDM formulations increased approximately 4 C. following three months tritium exposure.
Date: November 12, 2008
Creator: Clark, E
Object Type: Article
System: The UNT Digital Library
A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge (open access)

A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge

Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are …
Date: November 12, 2007
Creator: de Stadler, M & Chand, K
Object Type: Report
System: The UNT Digital Library

Discovering and validating biological hypotheses from coherent patterns in functional genomics data

The area of transcriptomics analysis is among the more established in computational biology, having evolved in both technology and experimental design. Transcriptomics has a strong impetus to develop sophisticated computational methods due to the large amounts of available whole-genome datasets for many species and because of powerful applications in regulatory network reconstruction as well as elucidation and modeling of cellular transcriptional responses. While gene expression microarray data can be noisy and comparisons across experiments challenging, there are a number of sophisticated methods that aid in arriving at statistically and biologically significant conclusions. As such, computational transcriptomics analysis can provide guidance for analysis of results from newer experimental technologies. More recently, search methods have been developed to identify modules of genes, which exhibit coherent expression patterns in only a subset of experimental conditions. The latest advances in these methods allow to integrate multiple data types anddatasets, both experimental and computational, within a single statistical framework accounting for data confidence and relevance to specific biological questions. Such frameworks provide a unified environment for the exploration of specific biological hypothesis and for the discovery of coherent data patterns along with the evidence supporting them.
Date: August 12, 2008
Creator: Joachimiak, Marcin Pawel
Object Type: Presentation
System: The UNT Digital Library
UNITED STATES DEPARTMENT OF ENERGY WASTE PROCESSING ANNUAL TECHNOLOGY DEVELOPMENT REPORT 2007 (open access)

UNITED STATES DEPARTMENT OF ENERGY WASTE PROCESSING ANNUAL TECHNOLOGY DEVELOPMENT REPORT 2007

The Office of Environmental Management's (EM) Roadmap, U.S. Department of Energy--Office of Environmental Management Engineering & Technology Roadmap (Roadmap), defines the Department's intent to reduce the technical risk and uncertainty in its cleanup programs. The unique nature of many of the remaining facilities will require a strong and responsive engineering and technology program to improve worker and public safety, and reduce costs and environmental impacts while completing the cleanup program. The technical risks and uncertainties associated with cleanup program were identified through: (1) project risk assessments, (2) programmatic external technical reviews and technology readiness assessments, and (3) direct site input. In order to address these needs, the technical risks and uncertainties were compiled and divided into the program areas of: Waste Processing, Groundwater and Soil Remediation, and Deactivation and Decommissioning (D&D). Strategic initiatives were then developed within each program area to address the technical risks and uncertainties in that program area. These strategic initiatives were subsequently incorporated into the Roadmap, where they form the strategic framework of the EM Engineering & Technology Program. The EM-21 Multi-Year Program Plan (MYPP) supports the goals and objectives of the Roadmap by providing direction for technology enhancement, development, and demonstrations that will lead to …
Date: August 12, 2008
Creator: Bush, S
Object Type: Report
System: The UNT Digital Library
Void Coalescence Processes Quantified Through Atomistic and Multiscale Simulation (open access)

Void Coalescence Processes Quantified Through Atomistic and Multiscale Simulation

Simulation of ductile fracture at the atomic scale reveals many aspects of the fracture process including specific mechanisms associated with void nucleation and growth as a precursor to fracture and the plastic deformation of the material surrounding the voids and cracks. Recently we have studied void coalescence in ductile metals using large-scale atomistic and continuum simulations. Here we review that work and present some related investigations. The atomistic simulations involve three-dimensional strain-controlled multi-million atom molecular dynamics simulations of copper. The correlated growth of two voids during the coalescence process leading to fracture is investigated, both in terms of its onset and the ensuing dynamical interactions. Void interactions are quantified through the rate of reduction of the distance between the voids, through the correlated directional growth of the voids, and through correlated shape evolution of the voids. The critical inter-void ligament distance marking the onset of coalescence is shown to be approximately one void radius based on the quantification measurements used, independent of the initial separation distance between the voids and the strain-rate of the expansion of the system. No pronounced shear flow is found in the coalescence process. We also discuss a technique for optimizing the calculation of fine-scale information …
Date: January 12, 2007
Creator: Rudd, R E; Seppala, E T; Dupuy, L M & Belak, J
Object Type: Article
System: The UNT Digital Library
Coupling of the 4f Electrons in Lanthanide Molecules (open access)

Coupling of the 4f Electrons in Lanthanide Molecules

(C5Me5)2LnOTf where Ln = La, Ce, Sm, Gd, and Yb have been synthesized and these derivatives are good starting materials for the synthesis of (C5Me5)2LnX derivatives. (C5Me5)2Ln(2,2'-bipyridine), where Ln = La, Ce, Sm, and Gd, along with several methylated bipyridine analogues have been synthesized and their magnetic moments have been measured as a function of temperature. In lanthanum, cerium, and gadolinium complexes the bipyridine ligand ligand is unequivocally the radical anion, and the observed magnetic moment is the result of intramolecular coupling of the unpaired electron on the lanthanide fragment with the unpaired electron on the bipyridine along with the intermolecular coupling between radicals. Comparison with the magnetic moments of the known compounds (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine) leads to an understanding of the role of the Sm(II)/Sm(III) and Yb(II)/Yb(III) couple in the magnetic properties of (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine). In addition, crystal structures of (C5Me5)2Ln(2,2'-bipyridine) and [(C5Me5)2Ln(2,2'-bipyridine)][BPh4](Ln= Ce and Gd), where the lanthanide is unequivocally in the +3 oxidation state, give the crystallographic characteristics of bipyridine as an anion and as a neutral ligand in the same coordination environment, respectively. Substituted bipyridine ligands coordinated to (C5Me5)2Yb are studied to further understand how the magnetic coupling in (C5Me5)2Yb(2,2'-bipyridine) changes with substitutions. In the …
Date: September 12, 2008
Creator: Kazhdan, Daniel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Convergence Analysis of a Domain Decomposition Paradigm (open access)

Convergence Analysis of a Domain Decomposition Paradigm

We describe a domain decomposition algorithm for use in several variants of the parallel adaptive meshing paradigm of Bank and Holst. This algorithm has low communication, makes extensive use of existing sequential solvers, and exploits in several important ways data generated as part of the adaptive meshing paradigm. We show that for an idealized version of the algorithm, the rate of convergence is independent of both the global problem size N and the number of subdomains p used in the domain decomposition partition. Numerical examples illustrate the effectiveness of the procedure.
Date: June 12, 2006
Creator: Bank, R E & Vassilevski, P S
Object Type: Article
System: The UNT Digital Library
Communication Requirements and Interconnect Optimization forHigh-End Scientific Applications (open access)

Communication Requirements and Interconnect Optimization forHigh-End Scientific Applications

The path towards realizing peta-scale computing isincreasingly dependent on building supercomputers with unprecedentednumbers of processors. To prevent the interconnect from dominating theoverall cost of these ultra-scale systems, there is a critical need forhigh-performance network solutions whose costs scale linearly with systemsize. This work makes several unique contributions towards attaining thatgoal. First, we conduct one of the broadest studies to date of high-endapplication communication requirements, whose computational methodsinclude: finite-difference, lattice-bolzmann, particle in cell, sparselinear algebra, particle mesh ewald, and FFT-based solvers. Toefficiently collect this data, we use the IPM (Integrated PerformanceMonitoring) profiling layer to gather detailed messaging statistics withminimal impact to code performance. Using the derived communicationcharacterizations, we next present fit-trees interconnects, a novelapproach for designing network infrastructure at a fraction of thecomponent cost of traditional fat-tree solutions. Finally, we propose theHybrid Flexibly Assignable Switch Topology (HFAST) infrastructure, whichuses both passive (circuit) and active (packet) commodity switchcomponents to dynamically reconfigure interconnects to suit thetopological requirements of scientific applications. Overall ourexploration leads to a promising directions for practically addressingthe interconnect requirements of future peta-scale systems.
Date: November 12, 2007
Creator: Kamil, Shoaib; Oliker, Leonid; Pinar, Ali & Shalf, John
Object Type: Article
System: The UNT Digital Library
Measured Peak Equipment Loads in Laboratories (open access)

Measured Peak Equipment Loads in Laboratories

This technical bulletin documents measured peak equipment load data from 39 laboratory spaces in nine buildings across five institutions. The purpose of these measurements was to obtain data on the actual peak loads in laboratories, which can be used to rightsize the design of HVAC systems in new laboratories. While any given laboratory may have unique loads and other design considerations, these results may be used as a 'sanity check' for design assumptions.
Date: September 12, 2007
Creator: Mathew, Paul A.
Object Type: Report
System: The UNT Digital Library
Breakdown Characteristics Study on an 18 Cell X-band Structure (open access)

Breakdown Characteristics Study on an 18 Cell X-band Structure

A CLIC designed 18 cells, low group velocity (2.4% to 1.0% c), X-band (11.4 GHz) accelerator structure (denoted T18) was designed at CERN, its cells were built at KEK, and it was assembled and tested at SLAC. An interesting feature of this structure is that the gradient in the last cell is about 50% higher than that in the first cell. This structure has been RF conditioned at SLAC NLCTA for about 1400 hours where it incurred about 2200 breakdowns. This paper presents the characteristics of these breakdowns, including (1) the breakdown rate dependence on gradient, pulse width and conditioning time, (2) the breakdown distribution along the structure, (3) relation between breakdown and pulsed heating dependence study and (4) electric field decay time for breakdown changing over the whole conditioning time. Overall, this structure performed very well, having a final breakdown rate of less than 1e-6/pulse/m at 106 MV/m with 230 ns pulse width.
Date: November 12, 2008
Creator: Wang, Faya
Object Type: Article
System: The UNT Digital Library
IMPACT OF INCREASED ALUMINATE CONCENTRATIONS ON PROPERTIES OF SALTSTONE MIXES (open access)

IMPACT OF INCREASED ALUMINATE CONCENTRATIONS ON PROPERTIES OF SALTSTONE MIXES

One of the goals of the Saltstone variability study is to identify the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. The protocols developed in this variability study are ideally suited as a tool to assess the impact of proposed changes to the processing flow sheet for Liquid Waste Operations (LWO). One such proposal that is currently under consideration is to introduce a leaching step in the treatment of the High Level Waste (HLW) sludge to remove aluminum prior to vitrification at the Defense Waste Processing Facility (DWPF). This leachate would significantly increase the soluble aluminate concentrations as well as the free hydroxide ion concentration in the salt feed that will be processed at the Saltstone Processing Facility (SPF). Consequently, an initial study of the impact of increased aluminate concentration on the Saltstone grout properties was performed. The projected compositions and ranges of the aluminate rich salt stream (which includes the blending strategy) are not yet available and consequently, in this initial report, two separate salt stream compositions were investigated. The first stream starts with the previously projected baseline composition of the salt solution that will be fed to SPF from …
Date: October 12, 2007
Creator: Harbour, J; Tommy Edwards, T; Erich Hansen, E & Vickie Williams, V
Object Type: Report
System: The UNT Digital Library
Final Report DE-FG02-97ER62475 (open access)

Final Report DE-FG02-97ER62475

This project began with the simple goal of trying to understand the diversity of dissimilatory metal-reducing microorganisms that might be found in subsurface environments. It ended with a sophisticated understanding not only of what microorganisms are important for metal reduction in uranium-contaminated subsurface environments, but also their physiological status during in situ uranium bioremediation. These findings have provided unprecedented insight into uranium bioremediation and the methods by which this process might be optimized. A brief summary of the major accomplishments of the project is given.
Date: March 12, 2008
Creator: Lovley, Derek, R.
Object Type: Report
System: The UNT Digital Library