Free-electron laser generation of VUV and x-ray radiation using a conditioned beam and ion-channel focusing (open access)

Free-electron laser generation of VUV and x-ray radiation using a conditioned beam and ion-channel focusing

The use of ion-focusing and a conditioned beam greatly enhances FEL gain in the VUV and Soft X-Ray range. The equations governing FEL amplification are derived and results of a linear analysis are noted. Numerical results, including 3D effects and having an order of magnitude improvement in gain, are presented for a 30 {Angstrom} example. 3 refs., 2 figs., 1 tab.
Date: August 30, 1991
Creator: Yu, Li-Hua (Brookhaven National Lab., Upton, NY (United States)); Sessler, A. & Whittum, D.H. (Lawrence Berkeley Lab., CA (United States))
System: The UNT Digital Library
Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells (open access)

Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells

None
Date: June 30, 1999
Creator: Muschler, J.; Lochter, A.; Roskelley, C. D.; Yurchenco, P. & Bissell, M. J.
System: The UNT Digital Library
Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes (open access)

Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes

Performance (cost/kWe and efficiency) of generic Compact Fusion Advanced Rankine (CFARII) power conversion is investigated for various working fluids, operating temperatures and pressures, and thermal power levels. A general conclusion is that good CFARII performance is found for a remarkably broad range of materials, temperatures, pressures and power levels, which gives considerable flexibility to future design studies which may apply CFARII energy conversion to specific fusion energy sources such as ICF, MICF, and Mini-PACER. 5 refs, 7 figs., 2 tabs.
Date: September 30, 1991
Creator: Logan, B. G.
System: The UNT Digital Library
An automated tool for evaluating compliance and providing assistance with building energy standards during design (open access)

An automated tool for evaluating compliance and providing assistance with building energy standards during design

In an effort to encourage the maximum cost-effective level of energy efficiency in new building design, energy-efficiency standards have become more location-specific and performance-based. As a result, standards often provide more than one path for ensuring and demonstrating that a design complies, but at the cost of increased complexity. In addition, the burden of remedying a noncompliant design rests on the designers' knowledge and experience, with only general guidance provided by the standards. As part of efforts in the US Department of Energy's (DOE's) Advanced Energy Design and Operation Technologies (AEDOT) project, a team at DOE's Pacific Northwest Laboratory is developing a computer program known as the Energy Standards Intelligent Design Tool (ES-IDT). The ES-IDT is one component of a prototype computer-based building design environment. It performs automatic compliance checking for parts of ASHRAE/IES Standard 90.1-1989 and provides designers assistance in bringing noncomplying designs into compliance. This paper describes the ES-IDT, the functions it provides, and how it is integrated into the design process via the AEDOT prototype building design environment. 9 refs.
Date: April 30, 1992
Creator: Quadrel, R.W.; Brambley, M.R. & Stratton, R.C.
System: The UNT Digital Library
Duct Systems in Large Commercial Buildings: Physical Characterization, Air Leakage, and Heat Conduction Gains (open access)

Duct Systems in Large Commercial Buildings: Physical Characterization, Air Leakage, and Heat Conduction Gains

None
Date: March 30, 1999
Creator: Fisk, William J.; Delp, Woody W.; Diamond, Rick C.; Dickerhoff, Darryl J.; Levinson, Ronnen M.; Modera, Mark P. et al.
System: The UNT Digital Library
Stress-strain gage measurements on a Nevada Test Site (NTS) event using pairs of triple foil gages (open access)

Stress-strain gage measurements on a Nevada Test Site (NTS) event using pairs of triple foil gages

A triple-material stress-strain gage containing foils of ytterbium, manganin, and constantan was tested at LLNL. This gage yields three independent piezoresistance measurements from which an independent set of principal strains and principal stresses can be inferred. We have analyzed the signals from a gage at a specific location buried at a distance from the center of energy of an event at NTS. We inverted the resistivity signals to calculate the stress and strain histories as sensed by the foils. Using the elastic material properties and the traction and displacement conditions at the various material interfaces from the foils to the host geological medium, we calculated the stress and strain histories in the host geological medium. However, because of uncertainties in the elastic properties of the layers of surrounding materials, we calculated significant variations in both the peaks and signatures of the stress and strain histories that could produce the foil stress and strain histories. We conclude that, because of the inclusion problem, accurate measurements of the stress-strain histories in the host geological medium can be adequately addressed only by minimizing, as much as possible, such uncertainties.
Date: November 30, 1990
Creator: Kansa, E. J. & Stout, R. B.
System: The UNT Digital Library
A quantum theory of the mind-brain interface (open access)

A quantum theory of the mind-brain interface

The Heisenberg quantum mechanical conception of nature is extended and applied to the brain. Strict adherence to the principle of parsimony, and to quantum thinking, produces naturally, on the basis of an overview of brain operation compatible with the information provided by the brain sciences, a unified description of the physical and mental aspects of nature that can account in principle for the full content of felt human experience. 33 refs.
Date: July 30, 1990
Creator: Stapp, Henry P.
System: The UNT Digital Library
3D simulations of axially confined heavy ion beams in round and square pipes (open access)

3D simulations of axially confined heavy ion beams in round and square pipes

We have been using the 3d PIC code WARP6 to model the behavior of beams in a heavy ion induction accelerator; such linacs are candidates for an ICF driver. Improvements have been added to the code to model an axially confined beam using comoving axial electric fields to simulate the confining ears'' applied to the accelerating pulses in a real system. We have also added a facility for modeling a beam in a round pipe, applying a capacity matrix to each axial Fourier mode in turn. These additions are described along with results, such as the effect of pipe shape on the beam quality degradation from quadrupole misalignments. 4 refs., 6 figs., 1 tab.
Date: November 30, 1990
Creator: Grote, D. P.; Friedman, A. (Lawrence Livermore National Lab., CA (USA)) & Haber, I. (Naval Research Lab., Washington, DC (USA))
System: The UNT Digital Library
3D Particle Simulation of Beams Using the Warp Code: Transport Around Bends (open access)

3D Particle Simulation of Beams Using the Warp Code: Transport Around Bends

WARP is a discrete-particle simulation program which was developed for studies of space charge dominated ion beams. It combines features of an accelerator code and a particle-in-cell plasma simulation. The code architecture, and techniques employed to enhance efficiency, are briefly described. Current applications are reviewed. In this paper we emphasize the physics of transport of three-dimensional beams around bends. We present a simple bent-beam PIC algorithm. Using this model, we have followed a long, thin beam around a bend in a simple racetrack system (assuming straight-pipe self-fields). Results on beam dynamics are presented; no transverse emittance growth (at mid-pulse) is observed. 11 refs., 5 figs.
Date: November 30, 1990
Creator: Friedman, A.; Grote, D. P.; Callahan, D. A.; Langdon, A. B. & Haber, I.
System: The UNT Digital Library
Heavy-element nucleosynthesis (open access)

Heavy-element nucleosynthesis

New measurements and theoretical studies of nuclear properties, together with new astronomical data on the growth of heavy-element abundances during the early history of the Galaxy, now provide a clearer picture of where in nature the elements heavier than iron are produced by rapid (r-process) and show (s-process) neutron capture reactions. The nuclear data suggest that the r-process involves a high-neutron-density beta-flow equilibrium environment and that the s-process may have occurred at a temperature and neutron density consistent with a {sup 13}C({alpha},n){sup 16}0 neutron source. The astronomical data, when compared with simple galactic chemical evolution modes, suggests that the r-process is associated with type II supernovae and that the neutron source must be manufactured by the star. Low-mass type II supernovae are proposed as the most important contributors to the r-process. A {sup 13}C neutron source in intermediate-mass stars is proposed for the s-process. 64 refs., 7 figs.
Date: October 30, 1990
Creator: Mathews, G. J.
System: The UNT Digital Library
Modelling atmospheric turbulence effects on ground-based telescope systems (open access)

Modelling atmospheric turbulence effects on ground-based telescope systems

Questions still exist concerning the appropriate model for turbulence- induced phase fluctuations seen in ground-based telescopes. Bester et al. used a particular observable (slope of the Allan variance) with an infrared interferometer in an attempt to distinguish models. The authors have calculated that observable for Kolmogorov and {open_quotes}random walk{close_quotes} models with a variety of outer scales and altitude-dependent turbulence and wind velocity. The authors have found that clear distinction between models requires good data on the vertical distribution of wind and turbulence. Furthermore, measurements at time separations of order 60 s are necessary to distinguish the {open_quotes}random walk{close_quotes} model from the Kolmogorov model.
Date: September 30, 1993
Creator: Bradford, L. W.; Flatte, S. M. & Max, C. E.
System: The UNT Digital Library
Public participation at Fernald: FERMCO`s evolving role (open access)

Public participation at Fernald: FERMCO`s evolving role

In an effort to improve public involvement in the site restoration decision making process, the DOE has established site specific advisory boards, of which the Fernald Citizens Task Force is one. The Fernald Task Force is focused on making recommendations in four areas: (1) What should be the future use of the site? (2) Determinations of cleanup levels (how clean is clean?) (3) Where should the wastes be disposed of? (4) What should be the cleanup priorities? Because these questions are being asked very early in the decision-making process, the answers are necessarily qualified, and are based on a combination of preliminary data, assumptions, and professional judgment. The requirement to make progress in the absence of accurate data has necessitated FERMCO and the Task Force to employ an approach similar to sensitivity analysis, in which a range of possible data values are evaluated and the relative importance of the various factors is assessed. Because of its charter to provide recommendations of future site use, the Task Force has developed a sitewide perspective, compared to the more common operable unit specific focus of public participation under CERCLA. The relationship between FERMCO and the Task Force is evolving toward one of partnership …
Date: January 30, 1995
Creator: Williams, J. B.; Fellman, R. W. & Brettschneider, D. J.
System: The UNT Digital Library
Fernald waste management and disposition (open access)

Fernald waste management and disposition

Historically waste management within the Department of Energy complex has evolved around the operating principle of packaging waste generated and storing until a later date. In many cases wastes were delivered to onsite waste management organizations with little or no traceability to origin of generation. Sites then stored their waste for later disposition offsite or onsite burial. While the wastes were stored, sites incurred additional labor costs for maintaining, inspecting and repackaging containers and capital costs for storage warehouses. Increased costs, combined with the inherent safety hazards associated with storage of hazardous material make these practices less attractive. This paper will describe the methods used at the Department of Energy`s Fernald site by the Waste Programs Management Division to integrate with other site divisions to plan in situ waste characterization prior to removal. This information was utilized to evaluate and select disposal options and then to package and ship removed wastes without storage.
Date: January 30, 1995
Creator: West, M. L.; Fisher, L. A.; Frost, M. L. & Rast, D. M.
System: The UNT Digital Library
Use of experience data for DOE seismic evaluations (open access)

Use of experience data for DOE seismic evaluations

As dictated by DOE Order 5480.28, seismic evaluations of essential systems and components at DOE facilities will be conducted over the next several years. For many of these systems and components, few, if any, seismic requirements applied to the original design, procurement, installation, and maintenance process. Thus the verification of the seismic adequacy of existing systems and components presents a difficult challenge. DOE has undertaken development of the criteria and procedures for these seismic evaluations that will maximize safety benefits in a timely and cost effective manner. As demonstrated in previous applications at DOE facilities and by the experience from the commercial nuclear power industry, use of experience data for these evaluations is the only viable option for most existing systems and components. This paper describes seismic experience data, the needs at DOE facilities, the precedent of application at nuclear power plants and DOE facilities, and the program being put in place for the seismic verification task ahead for DOE.
Date: September 30, 1993
Creator: Barlow, M. W.; Budnitz, R.; Eder, S. J. & Eli, M. W.
System: The UNT Digital Library
Utilizing a Russian space nuclear reactor for a United States space mission: Systems integration issues (open access)

Utilizing a Russian space nuclear reactor for a United States space mission: Systems integration issues

The Nuclear Electric Propulsion Space Test Program (NEPSTP) has developed a cooperative relationship with several institutes of the former Soviet Union to evaluate Russian space hardware on a US spacecraft One component is the Topaz II Nuclear Power System; a built and flight qualified nuclear reactor that has yet to be tested in space. The access to the Topaz II reactor provides the NEPSTP with a rare opportunity; to conduct an early flight demonstration of nuclear electric propulsion at a relatively low cost. This opportunity, however, is not without challenges. Topaz II was designed to be compatible with Russian spacecraft and launch vehicles. It was manufactured and flight qualified by Russian techniques and standards and conforms to safety requirements of the former Soviet Union, not the United States. As it is desired to make minimal modifications to the Topaz II, integrating the reactor system with a United States spacecraft and launch vehicle presents an engineering challenge. This paper documents the lessons teamed regarding the integration of reactor based spacecraft and also some insight about integrating Russian hardware. It examines the planned integration flow along with specific reactor requirements that affect the spacecraft integration including American-Russian space system compatibility.
Date: September 30, 1993
Creator: Reynolds, E.; Schaefer, E.; Polansky, G.; Lacy, J. & Bocharov, A.
System: The UNT Digital Library
Gyrokinetic and global fluid simulations of tokamak microturbulence and transport (open access)

Gyrokinetic and global fluid simulations of tokamak microturbulence and transport

Results are presented from the first systematic nonlinear kinetic simulation study of the swings and parameter dependences of toroidal ion-temperature-gradient (ITG) turbulence and transport, and from the first such study that includes sheared toroidal flows. Key results include the observation of clear gyroBohm scaling of the turbulent transport and of a surprisingly weak dependence of the transport on toroidal flow shear. Based on the simulation results, a parameterization of the transport is given that includes the dependence on all of the relevant physical parameters. The transition from local to nonlocal transport as a function of the profile scale length has been investigated using two-dimensional global fluid simulations of dissipative drift-wave turbulence. Local gyroBohm scaling is observed, except at very short profile scale lengths.
Date: August 30, 1994
Creator: Dimits, A. M.; Byers, J. A.; Williams, T. J.; Cohen, B. I.; Xu, W. Q.; Cohen, R. H. et al.
System: The UNT Digital Library
Adaptive Superplastic Forming Using NIKE2D with ISLAND (open access)

Adaptive Superplastic Forming Using NIKE2D with ISLAND

Superplastic forming has emerged as an important manufacturing process for producing near-net-shape parts. The design of a superplastic forming process is more difficult than conventional manufacturing operations, and is less amenable to trial and error approaches. This paper describes a superplastic forming process design capability incorporating nonlinear finite element analysis. The material constraints to allow superplastic behavior are integrated into an external constraint equation which is solved concurrently with the nonlinear finite element equations. The implementation of this approach using the ISLAND solution control language with the nonlinear finite element code NIKE2D is discussed in detail. Superplastic forming process design problems with one and two control parameters are presented as examples.
Date: July 30, 1992
Creator: Engelmann, Bruce E.; Whirley, Robert G. & Raboin, Peter J.
System: The UNT Digital Library
A programming paradigm for distributed-memory computers (open access)

A programming paradigm for distributed-memory computers

One of the problems that arises in programming a multicomputer is the effective partitioning of the work into tasks and the assigning of those tasks to the processors. We will present a programming paradigm as a method of structuring the algorithms, allowing us to identify and separate programming phases. This paradigm allows us to develop a general software tool for dynamically allocating work to the processors while hiding many details of load balancing. Our paradigm consists of four phases: partitioning the work, mapping the tasks into the processors connected by some virtual topology, running the application program, and embedding the virtual architecture into the actual machine. The paradigm applies to diverse problems and to a variety of multiprocessors without significant reprograming. We will use the multisection method for computing eigenvalues to show how this tool works.
Date: December 30, 1992
Creator: Crivelli, S. & Jessup, E. R.
System: The UNT Digital Library
Large spatial, temporal, and algorithmic adaptivity for implicit nonlinear finite element analysis (open access)

Large spatial, temporal, and algorithmic adaptivity for implicit nonlinear finite element analysis

The development of effective solution strategies to solve the global nonlinear equations which arise in implicit finite element analysis has been the subject of much research in recent years. Robust algorithms are needed to handle the complex nonlinearities that arise in many implicit finite element applications such as metalforming process simulation. The authors experience indicates that robustness can best be achieved through adaptive solution strategies. In the course of their research, this adaptivity and flexibility has been refined into a production tool through the development of a solution control language called ISLAND. This paper discusses aspects of adaptive solution strategies including iterative procedures to solve the global equations and remeshing techniques to extend the domain of Lagrangian methods. Examples using the newly developed ISLAND language are presented to illustrate the advantages of embedding temporal, algorithmic, and spatial adaptivity in a modem implicit nonlinear finite element analysis code.
Date: July 30, 1992
Creator: Engelmann, B. E. & Whirley, R. G.
System: The UNT Digital Library
A novel scheme to handle highly pulsed loads with a standard helium refrigerator (open access)

A novel scheme to handle highly pulsed loads with a standard helium refrigerator

Helium refrigerator performance degrades rapidly when it has to handle a varying or pulsed heat load. A novel scheme is presented to handle highly pulsed 4.5 K cryogenic loads with a standard helium refrigerator by isolating it from these pulses. The scheme uses a relatively simple arrangement of control valves, heat exchangers, and a storage dewar. Applications include pulsed tokamak machines such as TPX (Tokamak Physics Experiment) and ITER (International Thermonuclear Experimental Reactor). For example, the TPX (currently in the conceptual design phase in a DoE contract) requires an average 4.5 K refrigerator capacity of about 10 kW; however, pulsed loads caused by eddy current and nuclear heating will exceed 100 kW. The scheme presented here provides a method for handling these pulsed loads. Because of the simple and proven nature of the components involved and the thermodynamic properties of the helium, the system could be implemented for projects such as TPX or ITER with little or no development.
Date: June 30, 1993
Creator: Slack, D. S.
System: The UNT Digital Library
Restoring locality with faster-than-light velocities (open access)

Restoring locality with faster-than-light velocities

The idea of ``locality`` is a deep rooted concept. It does not have to be abandoned even if ``loophole free`` EPR experiments are performed and confirm the predictions of quantum theory. To satisfy locality, one can imagine that influences at a distance are exerted via mechanisms involving an ether and effects propagating in that ether a velocity V > c. Such model of physical phenomena is not Lorentz invariant but, with V large enough, the model can be made to reproduce the results of all experiments where quantum mechanics and Lorentz invariance have been verified.
Date: August 30, 1993
Creator: Eberhard, P. H.
System: The UNT Digital Library
Reciprocal interactions between Beta1-integrin and epidermal growth factor in three-dimensional basement membrane breast cultures: A different perspective in epithelial biology (open access)

Reciprocal interactions between Beta1-integrin and epidermal growth factor in three-dimensional basement membrane breast cultures: A different perspective in epithelial biology

Anchorage and growth factor independence are cardinal features of the transformed phenotype. Although it is logical that the two pathways must be coregulated in normal tissues to maintain homeostasis, this has not been demonstrated directly. We showed previously that down-modulation of {beta}1-integrin signaling reverted the malignant behavior of a human breast tumor cell line (T4-2) derived from phenotypically normal cells (HMT-3522) and led to growth arrest in a threedimensional (3D) basement membrane assay in which the cells formed tissue-like acini (14). Here, we show that there is a bidirectional cross-modulation of {beta}1-integrin and epidermal growth factor receptor (EGFR) signaling via the mitogenactivated protein kinase (MAPK) pathway. The reciprocal modulation does not occur in monolayer (2D) cultures. Antibodymediated inhibition of either of these receptors in the tumor cells, or inhibition of MAPK kinase, induced a concomitant downregulation of both receptors, followed by growth-arrest and restoration of normal breast tissue morphogenesis. Crossmodulation and tissue morphogenesis were associated with attenuation of EGF-induced transient MAPK activation. To specifically test EGFR and {beta}1-integrin interdependency, EGFR was overexpressed in nonmalignant cells, leading to disruption of morphogenesis and a compensatory up-regulation of {beta}1-integrin expression, again only in 3D. Our results indicate that when breast cells are spatially …
Date: September 30, 1998
Creator: Wang, F.; Weaver, V. M.; Petersen, O. W.; Larabell, C. A.; Dedhar, S.; Briand, P. et al.
System: The UNT Digital Library
Detection of uranium enrichment activities using environmental monitoring techniques (open access)

Detection of uranium enrichment activities using environmental monitoring techniques

Uranium enrichment processes have the capability of producing weapons-grade material in the form of highly enriched uranium. Thus, detection of undeclared uranium enrichment activities is an international safeguards concern. The uranium separation technologies currently in use employ UF{sub 6} gas as a separation medium, and trace quantities of enriched uranium are inevitably released to the environment from these facilities. The isotopic content of uranium in the vegetation, soil, and water near the plant site will be altered by these releases and can provide a signature for detecting the presence of enriched uranium activities. This paper discusses environmental sampling and analytical procedures that have been used for the detection of uranium enrichment facilities and possible safeguards applications of these techniques.
Date: March 30, 1993
Creator: Belew, W. L.; Carter, J. A.; Smith, D. H. & Walker, R. L.
System: The UNT Digital Library
The Second Colloquium on Petroleum Engineering Education (open access)

The Second Colloquium on Petroleum Engineering Education

This paper describes findings from the Second Colloquium on Petroleum engineering Education. The purpose of this colloquium was to provide a forum for petroleum engineering educators and representatives from industry and government to explore critical issues facing petroleum engineering education as we move into the 21st Century. It was expected that the colloquium would identify areas where changes are needed in petroleum engineering education, to best prepare students for careers in the oil and gas industry or other, related industries.
Date: November 30, 1993
Creator: Willhite, G. P. & Forney, R. H.
System: The UNT Digital Library