Resource Type

The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position' (open access)

The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position'

None
Date: October 31, 2001
Creator: Cobessi, D.; Huang, L.-S.; Ban, M.; Pon, N. G.; Daldal, F. & Berry, E. A.
System: The UNT Digital Library
3-D Mapping Technologies for High Level Waste Tanks (open access)

3-D Mapping Technologies for High Level Waste Tanks

This research investigated four techniques that could be applicable for mapping of solids remaining in radioactive waste tanks at the Savannah River Site: stereo vision, LIDAR, flash LIDAR, and Structure from Motion (SfM). Stereo vision is the least appropriate technique for the solids mapping application. Although the equipment cost is low and repackaging would be fairly simple, the algorithms to create a 3D image from stereo vision would require significant further development and may not even be applicable since stereo vision works by finding disparity in feature point locations from the images taken by the cameras. When minimal variation in visual texture exists for an area of interest, it becomes difficult for the software to detect correspondences for that object. SfM appears to be appropriate for solids mapping in waste tanks. However, equipment development would be required for positioning and movement of the camera in the tank space to enable capturing a sequence of images of the scene. Since SfM requires the identification of distinctive features and associates those features to their corresponding instantiations in the other image frames, mockup testing would be required to determine the applicability of SfM technology for mapping of waste in tanks. There may be …
Date: August 31, 2010
Creator: Marzolf, A. & Folsom, M.
System: The UNT Digital Library
3-D subsurface modeling within the framework of an environmental restoration information system: Prototype results using earthvision (open access)

3-D subsurface modeling within the framework of an environmental restoration information system: Prototype results using earthvision

As a result of the DOE Oak Ridge Reservation (DOE-ORR) placement on the EPA Superfund National Priorities List in December of 1989, all remedial activities, including characterization, remedial alternatives selection, and implementation of remedial measures, must meet the combined requirements of RCRA, CERCLA, and NEPA. The Environmental Restoration Program, therefore, was established with the mission of eliminating or reducing to prescribed safe levels the risks to the environment or to human health and safety posed by inactive and surplus DOE-ORR managed sites and facilities that have been contaminated by radioactive and surplus DOE-ORR managed sites and facilities that have been contaminated by radioactive, hazardous, or mixed wastes. In accordance with an established Federal Facilities Agreement (FFA), waste sites and facilities across the DOE-ORR have been inventoried, prioritized, and are being systematically investigated and remediated under the direction of Environmental Restoration. EarthVision, a product of Dynamic Graphics, Inc., that provides three-dimensional (3-D) modeling and visualization, was exercised within the framework of an environmental restoration (ER) decision support system. The goal of the prototype was to investigate framework integration issues including compatibility and value to decision making. This paper describes the ER program, study site, and information system framework; selected EarthVision results …
Date: December 31, 1994
Creator: Goeltz, R. T. & Zondlo, T. F.
System: The UNT Digital Library
4-D XRD for strain in many grains using triangulation (open access)

4-D XRD for strain in many grains using triangulation

Determination of the strains in a polycrystalline materialusing 4-D XRD reveals sub-grain and grain-to-grain behavior as a functionof stress. Here 4-D XRD involves an experimental procedure usingpolychromatic micro-beam X-radiation (micro-Laue) to characterizepolycrystalline materials in spatial location as well as with increasingstress. The in-situ tensile loading experiment measured strain in a modelaluminum-sapphire metal matrix composite using the Advanced Light Source,Beam-line 7.3.3. Micro-Laue resolves individual grains in thepolycrystalline matrix. Results obtained from a list of grains sorted bycrystallographic orientation depict the strain states within and amongindividual grains. Locating the grain positions in the planeperpendicular to the incident beam is trivial. However, determining theexact location of grains within a 3-D space is challenging. Determiningthe depth of the grains within the matrix (along the beam direction)involved a triangulation method tracing individual rays that producespots on the CCD back to the point of origin. Triangulation wasexperimentally implemented by simulating a 3-D detector capturingmultiple diffraction images while increasing the camera to sampledistance. Hence by observing the intersection of rays from multiple spotsbelonging to the corresponding grain, depth is calculated. Depthresolution is a function of the number of images collected, grain to beamsize ratio, and the pixel resolution of the CCD. The 4DXRD methodprovides grain morphologies, strain …
Date: December 31, 2006
Creator: Bale, Hrishikesh A.; Hanan, Jay C. & Tamura, Nobumichi
System: The UNT Digital Library
5. international workshop on the identification of transcribed sequences (open access)

5. international workshop on the identification of transcribed sequences

This workshop was held November 5--8, 1995 in Les Embiez, France. The purpose of this conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on mapping the human genome. Attention is focused on the following topics: transcriptional maps; functional analysis; techniques; model organisms; and tissue specific libraries and genes. Abstracts are included of the papers that were presented.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
D = 5 Maximally Supersymmetric Yang-Mills Theory Diverges at Six Loops (open access)

D = 5 Maximally Supersymmetric Yang-Mills Theory Diverges at Six Loops

None
Date: October 31, 2012
Creator: Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Douglas, Michael R.; von Hippel, Matt & Johansson, Henrik
System: The UNT Digital Library
8. annual national conference of black physics students -- A summary report (open access)

8. annual national conference of black physics students -- A summary report

The primary goals of the conference were to: (1) Develop a peer/mentor network within the African-American physics community; (2) Inform African-American students in physics of the various academic and professional opportunities; and (3) Bring important academic, economic and political issues and developments in the field to the attention of the students. The conference program was designed to fulfill these goals and optimize the students` exposure to physics as a professional and its real-life applications in both industry and academia.
Date: December 31, 1994
Creator: Valk, H.S.
System: The UNT Digital Library
An 8-Element Fast-Neutron Double-Scatter Directional Detector. (open access)

An 8-Element Fast-Neutron Double-Scatter Directional Detector.

We have constructed a fast-neutron double-scatter spectrometer that efficiently measures the neutron spectrum and direction of a spontaneous fission source. The device consists of two planes of organic scintillators, each having an area of 125 cm{sup 2}, efficiently coupled to photomultipliers. The four scintillators in the front plane are 2 cm thick, giving almost 25% probability of detecting an incident fission-spectrum neutron at 2 MeV by proton recoil and subsequent ionization. The back plane contains four 5-cm-thick scintillators which give a 40% probability of detecting a scattered fast neutron. A recordable double-scatter event occurs when a neutron is detected in both a front plane detector and a back plane detector within an interval of 500 nanoseconds. Each double-scatter event is analyzed to determine the energy deposited in the front plane, the time of flight between detectors, and the energy deposited in the back plane. The scattering angle of each incident neutron is calculated from the ratio of the energy deposited in the first detector to the kinetic energy of the scattered neutron.
Date: July 31, 2005
Creator: Vanier, P. E. & Forman, L.
System: The UNT Digital Library
9. international mouse genome conference (open access)

9. international mouse genome conference

This conference was held November 12--16, 1995 in Ann Arbor, Michigan. The purpose of this conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on genetic mapping in mice. This report contains abstracts of presentations, focusing on the following areas: mutation identification; comparative mapping; informatics and complex traits; mutagenesis; gene identification and new technology; and genetic and physical mapping.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
A 10-GeV, 5-MW proton source for a muon-muon collider (open access)

A 10-GeV, 5-MW proton source for a muon-muon collider

The performance parameters of a proton source which produces the required flux of muons for a 2-TeV on 2-TeV muon collider are: a beam energy of 10 GeV, a repetition rate of 30 Hz, two bunches per pulse with 5 x 10{sup 13} protons per bunch, and an rms bunch length of 3 nsec (1). Aside from the bunch length requirement, these parameters are identical to those of a 5-MW proton source for a spallation neutron source based on a 10-GeV rapid cycling synchrotron (RCS) (2). The 10-GeV synchrotron uses a 2-GeV accelerator system as its injector, and the 2-GeV RCS is an extension of a feasibility study for a I-MW spallation source described elsewhere (3--9). A study for the 5-MW spallation source was performed for ANL site-specific geometrical requirements. Details are presented for a site-independent proton source suitable for the muon collider utilizing the results of the 5-MW spallation source study.
Date: December 31, 1995
Creator: Cho, Y.; Chae, Y.-C. & Crosbie, E.
System: The UNT Digital Library
A 10-GeV, 5-MW proton source for a pulsed spallation source (open access)

A 10-GeV, 5-MW proton source for a pulsed spallation source

A feasibility study for a pulsed spallation source based on a 5-MW, 10-GeV rapid proton synchrotron (RCS) is in progress. The integrated concept and performance parameters of the facility are discussed. The 10-GeV synchrotron uses as its injector the 2-GeV accelerator system of a 1-MW source described elsewhere. The 1-MW source accelerator system consists of a 400-MeV H{sup {minus}} linac with 2.5 MeV energy spread in the 75% chopped (25% removed) beam and a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV. The time averaged current of the accelerator system is 0.5 mA, equivalent to 1.04 {times} 10{sup 14} protons per pulse. The 10-GeV RCS accepts the 2 GeV beam and accelerates it to 10 GeV. Beam transfer from the 2-GeV synchrotron to the 10-GeV machine u highly efficient bunch-to-bucket injection, so that the transfer can be made without beam loss. The synchrotron lattice uses FODO cells of 90{degrees} phase advance. Dispersion-free straight sections are obtained using a missing magnet scheme. The synchrotron magnets are powered by dual-frequency resonant circuits. The magnets are excited at a 20-Hz rate and de-excited at 60-Hz. resulting in an effective 30-Hz rate. A key feature of the design of this accelerator system …
Date: December 31, 1995
Creator: Cho, Y.; Chae, Y.C. & Crosbie, E.
System: The UNT Digital Library
10-GW COâ‚‚ laser system at the Brookhaven Accelerator Test Facility (open access)

10-GW COâ‚‚ laser system at the Brookhaven Accelerator Test Facility

Design and performance of a high peak-power CO{sub 2} laser system to produce subnanosecond IR pulses for electron acceleration experiment are presented. We discuss theoretical aspects of the picosecond laser pulse propagation in a molecular amplifier and a design approach towards compact Terawatt CO{sub 2} laser systems.
Date: December 31, 1993
Creator: Pogorelsky, I.; Fischer, J. & Fisher, A. S.
System: The UNT Digital Library
10. international mouse genome conference (open access)

10. international mouse genome conference

Ten years after hosting the First International Mammalian Genome Conference in Paris in 1986, Dr. Jean-Louis Guenet presided over the Tenth Conference at the Pasteur Institute, October 7--10, 1996. The 1986 conference was a satellite to the Human Gene Mapping Workshop and had approximately 50 attendees. The 1996 meeting was attended by 300 scientists from around the world. In the interim, the number of mapped loci in the mouse increased from 1,000 to over 20,000. This report contains a listing of the program and its participants, and two articles that review the meeting and the role of the laboratory mouse in the Human Genome project. More than 200 papers were presented at the conference covering the following topics: International mouse chromosome committee meetings; Mutant generation and identification; Physical and genetic maps; New technology and resources; Chromatin structure and gene regulation; Rate and hamster genetic maps; Informatics and databases; and Quantitative trait analysis.
Date: December 31, 1996
Creator: Meisler, M. H.
System: The UNT Digital Library
A 12 GHZ 50 MW Klystron for Support of Accelerator Research (open access)

A 12 GHZ 50 MW Klystron for Support of Accelerator Research

A 12 GHz 50MW X-band klystron is under development at the SLAC National Accelerator Laboratory Klystron Department. The klystron will be fabricated to support programs currently underway at three European Labs; CERN, PSI, and INFN Trieste. The choice of frequency selection was due to the CLIC RF frequency changing from 30 GHz to the European X-band frequency of 11.99 GHz in 2008. Since the Klystron Department currently builds 50MW klystrons at 11.424 GHz known collectively as the XL4 klystrons, it was deemed cost-effective to utilize many XL4 components by leaving the gun, electron beam transport, solenoid magnet and collector unchanged. To realize the rf parameters required, the rf cavities and rf output hardware were necessarily altered. Some improvements to the rf design have been made to reduce operating gradients and increase reliability. Changes in the multi-cell output structure, waveguide components, and the window will be discussed along with testing of the devices. Five klystrons known as XL5 klystrons are scheduled for production over the next two years.
Date: May 31, 2011
Creator: Sprehn, Daryl; Haase, Andrew; Jensen, Aaron; Jongewaard, Erik; Nantista, Christopher & Vlieks, Arnold
System: The UNT Digital Library
15. International Conference on Plant Growth Substances: Program -- Abstracts (open access)

15. International Conference on Plant Growth Substances: Program -- Abstracts

Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ``classical`` plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joined by a number of new signal molecules, e.g., systemin, jasmonic acid, salicylic acid, whose biosynthesis and functions are being understood in ever greater detail. Molecular genetics has opened new vistas in an understanding of transduction pathways that regulate developmental processes in response to hormonal and environmental signals. The program of the 15th Conference includes accounts of this progress and brings together scientists whose work focuses on physiological, biochemical, and chemical aspects of plant growth regulation. This volume contains the abstracts of papers presented at this conference.
Date: December 31, 1995
Creator: unknown
System: The UNT Digital Library
A 16 Mev/Nucleon Cocktail for Heavy Ion Testing (open access)

A 16 Mev/Nucleon Cocktail for Heavy Ion Testing

This report gives the description of a new cocktail of heavy ions ranging from Z=7-36 at 16 MeV/Nucleon.
Date: July 31, 2004
Creator: McMahan, M. A.; Leitner, D.; Gimpel, T.; Morel, J.; Ninemire, B.; Siero, R. et al.
System: The UNT Digital Library
25--30 T water cooled pulse magnet concept for neutron scattering experiment (open access)

25--30 T water cooled pulse magnet concept for neutron scattering experiment

The Manuel Lujan Jr. Neutron Scattering Center, Los Alamos National Laboratory is in need of a high field, split-pair, pulse magnet that would provide a 25--30 T field in a 25 mm bore and 10 mm split gap for 2--4 ms at a repetition rate of 2 Hz. Single stack Bitter magnets of this type providing less than 20 T vertical field in the split gap have been constructed before. To produce higher fields, there is a need to use a multiple layer coil with internal reinforcement. The magnet should withstand up to 10{sup 7} cycles of loading and unloading. The authors have conducted a feasibility study that address these unique requirements.
Date: December 31, 1997
Creator: Eyssa, Y. M.; Walsh, R. P.; Miller, J. R.; Pernambuco-Wise, P.; Bird, M. D.; Schneider-Muntau, H. J. et al.
System: The UNT Digital Library
40-{angstrom} FEL designs for the PEP storage ring (open access)

40-{angstrom} FEL designs for the PEP storage ring

We explore the use of the 2.2-km PEP storage ring at SLAC to drive a 40-{Angstrom} free-electron laser in the self-amplified spontaneous emission configuration. Various combinations for electron-beam and undulator parameters, as well as special undulator designs, are discussed. Saturation and high peak, in-band, coherent power (460 MW) are possible with a 67-m, hybrid permanent-magnet undulator in a ring bypass. A 100-m, cusp-field undulator can achieve high average, in-band, coherent power (0.25 W) in the main ring. The existing, 25.6-m, Paladin undulator at LLNL, with the addition of optical-klystron dispersive sections, is considered for both peak and average power. 35 refs., 4 figs., 1 tab.
Date: December 31, 1991
Creator: Fisher, A. S.; Gallardo, J. C.; Nuhn, H. D.; Tatchyn, R.; Winick, H. & Pellegrini, C.
System: The UNT Digital Library
A 50-MeV mm-wave electron linear accelerator system for production of tunable short wavelength synchrotron radiation (open access)

A 50-MeV mm-wave electron linear accelerator system for production of tunable short wavelength synchrotron radiation

The Advanced Photon Source (APS) at Argonne in collaboration with the University of Illinois at Chicago and the University of Wisconsin at Madison is developing a new millimeter wavelength, 50-MeV electron linear accelerator system for production of coherent tunable wavelength synchrotron radiation. Modern micromachining techniques based on deep etch x-ray lithography, LIGA (Lithografie, Galvanoformung, Abformung), capable of producing high-aspect ratio structures are being considered for the fabrication of the accelerating components.
Date: December 31, 1993
Creator: Nassiri, A.; Kustom, R. L.; Mills, F. E.; Kang, Y. W.; Matthews, P. J.; Grudzien, D. et al.
System: The UNT Digital Library
59. Cold Spring Harbor symposium on quantitative biology: Molecular genetics of cancer (open access)

59. Cold Spring Harbor symposium on quantitative biology: Molecular genetics of cancer

Investigation of the mechanistic aspects of cancer has its roots in the studies on tumor viruses and their effects on cell proliferation, function, and growth. This outstanding progress was well documented in previous Cold Spring Harbor Symposia on Quantitative Biology. In the early to mid 1980s, progress on the development of chromosome mapping strategies and the accumulation of DNA probes that identified polymorphisms, encouraged by the international Human Genome Project, enabled the identification of other genes that contributed to familial inheritance of high susceptibility to specific cancers. This approach was very successful and led to a degree of optimism that one aspect of cancer, the multistep genetic process from early neoplasia to metastatic tumors, was beginning to be understood. It therefore seemed appropriate that the 59th Symposium on Quantitative Biology focus attention on the Molecular Genetics of Cancer. The concept was to combine the exciting progress on the identification of new genetic alterations in human tumor cells with studies on the function of the cancer gene products and how they go awry in tumor cells.
Date: December 31, 1994
Creator: unknown
System: The UNT Digital Library
A 250 GHz microwave interferometer for divertor experiments on DIII-D (open access)

A 250 GHz microwave interferometer for divertor experiments on DIII-D

A new 250 GHz, two-frequency microwave interferometer system has been developed to diagnose divertor plasmas on DIII-D. This diagnostic will measure the line-averaged density across both the inner and outer, lower divertor legs. With a cut-off density of over 7 {times} 10{sup 14} cm{sup {minus}3}, temporal measurements of ELMs, MARFs and plasma detachment are expected. The outer leg system will use a double pass method while the inner leg system will be single pass. Two special 3D carbon composite tiles are used, one to protect the microwave antennas mounted directly under the strike point and the other as the outer leg reflecting surface. Performance, design constraints, and the thermalmechanical design of the 3D carbon composite tiles are discussed.
Date: January 31, 1994
Creator: James, R. A.; Nilson, D. G.; Stever, R. D.; Hill, D. N. & Casper, T. A.
System: The UNT Digital Library
360 Degree Photography to Decrease Exposure, Increase Safety & Minimize Waste (open access)

360 Degree Photography to Decrease Exposure, Increase Safety & Minimize Waste

High-resolution digital cameras, in conjunction with software techniques. make possible 360{sup o} photos that allow a person to look all around, up and dawn, and zoom in or out. The software provides the opportunity to attach other information to a 360{sup o} photo such as sound tiles, flat photos (providing additional detail about what is behind a panel or around a corner) and text (Information which can be used to show radiological conditions or identify other hazards not readily visible). The software also allows other 360{sup o} photos to be attached creating a virtual tour where the user can move from area to area, and stop, study and zoom in on areas of interest. A virtual tour of a building or room can be used for facility documentation, informing management and others, work planning and orientation, and training, thus minimizing the need to re-enter hazardous radioactive areas. Reducing entries decreases exposure, increases safety and minimizes waste.
Date: January 31, 2002
Creator: LeBaron, G. J.
System: The UNT Digital Library
1990 fuel cell seminar: Program and abstracts (open access)

1990 fuel cell seminar: Program and abstracts

This volume contains author prepared short resumes of the presentations at the 1990 Fuel Cell Seminar held November 25-28, 1990 in Phoenix, Arizona. Contained herein are 134 short descriptions organized into topic areas entitled An Environmental Overview, Transportation Applications, Technology Advancements for Molten Carbonate Fuel Cells, Technology Advancements for Solid Fuel Cells, Component Technologies and Systems Analysis, Stationary Power Applications, Marine and Space Applications, Technology Advancements for Acid Type Fuel Cells, and Technology Advancement for Solid Oxide Fuel Cells.
Date: December 31, 1990
Creator: unknown
System: The UNT Digital Library
1993 Department of Energy Records Management Conference (open access)

1993 Department of Energy Records Management Conference

This document consists of viewgraphs from the presentations at the conference. Topics included are: DOE records management overview, NIRMA and ARMA resources, NARA records management training, potential quality assurance records, filing systems, organizing and indexing technical records, DOE-HQ initiatives, IRM reviews, status of epidemiologic inventory, disposition of records and personal papers, inactive records storage, establishing administrative records, managing records at Hanford, electronic mail -- legal and records issues, NARA-GAO reports status, consultive selling, automated indexing, decentralized approach to scheduling at a DOE office, developing specific records management programs, storage and retrieval at Savannah River Plant, an optical disk case study, and special interest group reports.
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library