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Observations of Non-Close-Packed Arrangements in Multilayers of Passivated Gold Clusters (open access)

Observations of Non-Close-Packed Arrangements in Multilayers of Passivated Gold Clusters

The stacking of second and third layers of supercrystals of self-assembled passivated gold nanoparticles has been investigated using transmission electron microscopy. We report for the first time nanoparticles occupying the twofold saddle site in the third layer.
Date: October 5, 1999
Creator: AINDOW, M.; Brown, P.; Kiely, C. J.; Wellner, A. & Wilcoxon, Jess P.
Object Type: Article
System: The UNT Digital Library
The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors (open access)

The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors

A major concern in the design of thick-liquid protected inertial fusion reactors of all types is the dynamic response of the shielding liquid to the pulsed explosions. Induced liquid motion can stress and damage solid chamber structures such as the firstwall. In a z-pinch based inertial fusion (Z-IFE) reactor this issue becomes particularly critical due to the relatively large proposed target yields of several GJ. In this paper we summarize an analysis of the liquid response taking into account ablation of target facing surfaces, pocket venting, and neutron isochoric heating. The impact of varying several reactor parameters is also discussed.
Date: October 5, 2005
Creator: Abbott, R P
Object Type: Article
System: The UNT Digital Library
Carbon transport in the bottom boundary layer. Final report (open access)

Carbon transport in the bottom boundary layer. Final report

This report summarizes the activities and findings from a field experiment devised to estimate the rates and mechanisms of transport of carbon across the continental shelves. The specific site chosen for the experiment was the mid-Atlantic Bight, a region off the North Carolina coast. The experiment involved a large contingent of scientists from many institutions. The specific component of the program was the transport of carbon in the bottom boundary layer. The postulate mechanisms of transport of carbon in the bottom boundary layer are: resuspension and advection, downward deposition, and accumulation. The high turbulence levels in the bottom boundary layer require the understanding of the coupling between turbulence and bottom sediments. The specific issues addressed in the work reported here were: (a) What is the sediment response to forcing by currents and waves? (b) What is the turbulence climate in the bottom boundary layer at this site? and (c) What is the rate at which settling leads to carbon sequestering in bottom sediments at offshore sites?
Date: October 5, 1998
Creator: Agrawal, Yogesh C.
Object Type: Report
System: The UNT Digital Library
High Efficiency Release Targets for Use at ISOL Facilities: Computational Design (open access)

High Efficiency Release Targets for Use at ISOL Facilities: Computational Design

This report describes efforts made at the oak Rklge NatiOnrd Laboratory to design high- efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat-removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated-vitreous-carbon fiber (RVCF) or carbon-bonded-carbon fiber (CBCF) to form highly permeable composite target matrices. Computational studies that simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of targetheat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected targets and thermal analyses of temperature distributions within a prototype targetlheat-sink system subjected to primary ion beam irradiation will be presented in this report.
Date: October 5, 1999
Creator: Alton, G. D. & Liu, Y.
Object Type: Article
System: The UNT Digital Library
A Multi-Sample Cs-Sputter Negative Ion Source (open access)

A Multi-Sample Cs-Sputter Negative Ion Source

A multi-sample Cs sputter negative-ion source, equipped with a conical-geometry, W-surface-ionizer has been designed and fabricated that permits sample changes without disruption of on-line accelerator operation. Sample changing is effected by actuating an electro-pneumatic control system located at ground potential that drives an air-motor-driven sample-indexing-system mounted at high voltage; this arrangement avoids complications associated with indexing mechanisms that rely on electronic power-supplies located at high potential. In-beam targets are identified by LED indicator lights derived from a fiber-optic, Gray-code target-position sensor. Aspects of the overall source design and details of the indexing mechanism along with operational parameters, ion optics. intensities, and typical emittances for a variety of negative-ion species will be presented in this report.
Date: October 5, 1998
Creator: Alton, G. D.; Ball, J. A.; Bao, Y.; Cui, B.; Reed, C. A. & Williams, C.
Object Type: Article
System: The UNT Digital Library
ECR Ion Source Developments at the Oak Ridge National Laboratory (open access)

ECR Ion Source Developments at the Oak Ridge National Laboratory

New techniques for enhancing the performances of electron cyclotron resonance (ECR) ion sources are being investigated at the Oak Ridge National Laboratory. We have utilized the multiple discrete frequency technique to improve the charge state distributions extracted from conventional magnetic field geometry ECR source by injecting three frequencies into the source. A new flat central magnetic field concept, has been incorporated in the designs of a compact all-permanent-magnet source for high charge-state ion beam generation and a compact electromagnetic source for singly ionized radioactive ion beam generation for use in the Holifield Radioactive Ion Beam Facility (HRIBF) research program. A review of the three frequency injection experiments and descriptions of the design aspects of the "volume-type" ECR ion sources will be given in this report.
Date: October 5, 1998
Creator: Alton, G. D.; Liu, Y. & Meyer, F. W.
Object Type: Article
System: The UNT Digital Library
A High Efficiency, Kinetic-Ejection Negative Ion Source for RIB Generation (open access)

A High Efficiency, Kinetic-Ejection Negative Ion Source for RIB Generation

Chemically active radioactive species, diffused from RIB target materials, often arrive at the ionization chamber of the source in a variety of molecular forms. Because of the low probability for simultaneously dissociating and efficiently ionizing the individual atomic constituents of molecules with conventional hot-cathode electron-impact ion sources, the species of interest are often distributed in several mass channels in the form of molecular side-band beams and consequently, their intensities are diluted. The sputter negative ion beam generation technique offers an efficient means for simultaneously dissociating and ionizing highly electronegative atomic species present in molecular carriers. We have incorporated these principles in the design and fabrication of a kinetic ejection negative ion source and evaluated its potential for generating {sup 17,18}F{sup {minus}} beams for the Holifield Radioactive Ion Beam Facility astrophysics research program. The source utilizes Cs{sup +} beams to bombard condensable fluorine compounds that emanate from a target material, such as Al{sub 2}O{sub 3}, and are transported to the cooled inner surface of a conical-geometry cathode where they are adsorbed. The energetic Cs{sup +} beams efficiently dissociate these molecules and sputter their constituents. Since the work functions of cesiated surfaces are low, highly electronegative species such as fluorine are efficiently …
Date: October 5, 1998
Creator: Alton, G. D.; Liu, Y.; Murray, S. N. & Williams, C.
Object Type: Article
System: The UNT Digital Library
Research and Engineering Operation Irradiation Processing Department monthly record report, September 1965 (open access)

Research and Engineering Operation Irradiation Processing Department monthly record report, September 1965

This monthly report details research and engineering operation activities of the Irradiation Processing Department for the month of September 1965.
Date: October 5, 1965
Creator: Ambrose, T. W.
Object Type: Report
System: The UNT Digital Library
Filtered cathodic arc deposition with ion-species-selectivebias (open access)

Filtered cathodic arc deposition with ion-species-selectivebias

A dual-cathode arc plasma source was combined with acomputer-controlled bias amplifier such as to synchronize substrate biaswith the pulsed production of plasma. In this way, bias can be applied ina material-selective way. The principle has been applied to the synthesismetal-doped diamond-like carbon films, where the bias was applied andadjusted when the carbon plasma was condensing, and the substrate was atground when the metal was incorporated. In doing so, excessive sputteringby too-energetic metal ions can be avoided while the sp3/sp2 ratio can beadjusted. It is shown that the resistivity of the film can be tuned bythis species-selective bias. The principle can be extended tomultiple-material plasma sources and complex materials
Date: October 5, 2006
Creator: Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon & Lim, SunnieH.N.
Object Type: Article
System: The UNT Digital Library
Relativistic-klystron two-beam accelerator as a power source for future linear colliders (open access)

Relativistic-klystron two-beam accelerator as a power source for future linear colliders

The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2&A, l-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-n-n. The prototype accelerator will be used to study physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.
Date: October 5, 1998
Creator: Anderson, D. E.; Eylon, S.; Henestroza, E.; Houck, T. L.; Lidia, M.; Vanecek, D. L. et al.
Object Type: Article
System: The UNT Digital Library
Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages (open access)

Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain repository. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022 (Alloy 22), the environment is represented by aqueous brine films present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the tensile stress is principally from weld induced residual stress. SCC has historically been separated into ''initiation'' and ''propagation'' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding); or that develop from corrosion processes such as pitting or dissolution of inclusions. To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment to determine the time to through-wall …
Date: October 5, 2004
Creator: Andresen, P.; Gordon, G. & Lu, S.
Object Type: Report
System: The UNT Digital Library

Harnessing Innovation for a Renewable Energy Future

Keynote presentation given by Dan Arvizu at the Green Engineering Summit held in Anaheim, California on October 5, 2006.
Date: October 5, 2006
Creator: Arvizu, D.
Object Type: Presentation
System: The UNT Digital Library
Asymptotics of a free boundary problem (open access)

Asymptotics of a free boundary problem

This article is concerned with free boundary problems for the differential equations u{double_prime} + (2{nu} + 1)/r u{prime} + u - u{sup q} = 0, r > 0, where 0 {le} q < 1 and {nu} {ge} 0. As was shown by Kaper and Kwong, there exists a unique R > 0, such that the equation admits a classical solution u that is positive and monotone on (0,R) and that satisfies the boundary conditions u{prime}(0) = 0, u(R) = u{prime}(R) = 0. This article is concerned with the behavior of R and u(0) as q {yields} 1.
Date: October 5, 1992
Creator: Atkinson, F. V.; Kaper, H. G. & Kwong, Man Kam
Object Type: Report
System: The UNT Digital Library
Minutes of MTA Progress Meeting Held December 5, 1950 (open access)

Minutes of MTA Progress Meeting Held December 5, 1950

None
Date: October 5, 1950
Creator: Ball, Russell H.
Object Type: Report
System: The UNT Digital Library
Technical bases for precipitate hydrolysis process operating parameters (open access)

Technical bases for precipitate hydrolysis process operating parameters

This report provides the experimental data and rationale in support of the operating parameters for precipitate hydrolysis specified in WSRC-RP-92737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF).
Date: October 5, 1992
Creator: Bannochie, C. J.
Object Type: Report
System: The UNT Digital Library
Technical bases for precipitate hydrolysis process operating parameters (open access)

Technical bases for precipitate hydrolysis process operating parameters

This report provides the experimental data and rationale in support of the operating parameters for precipitate hydrolysis specified in WSRC-RP-92737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF).
Date: October 5, 1992
Creator: Bannochie, C.J.
Object Type: Report
System: The UNT Digital Library
Tracking the Sun II: The Installed Cost of Photovoltaics in the U.S. from 1998-2008 (open access)

Tracking the Sun II: The Installed Cost of Photovoltaics in the U.S. from 1998-2008

Installations of solar photovoltaic (PV) systems have been growing at a rapid pace in recent years. In 2008, 5,948 MW of PV was installed globally, up from 2,826 MW in 2007, and was dominated by grid-connected applications. The United States was the world's third largest PV market in terms of annual capacity additions in 2008, behind Spain and Germany; 335 MW of PV was added in the U.S. in 2008, 293 MW of which came in the form of grid-connected installations. Despite the significant year-on-year growth, however, the share of global and U.S. electricity supply met with PV remains small, and annual PV additions are currently modest in the context of the overall electric system. The market for PV in the U.S. is driven by national, state, and local government incentives, including up-front cash rebates, production-based incentives, requirements that electricity suppliers purchase a certain amount of solar energy, and Federal and state tax benefits. These programs are, in part, motivated by the popular appeal of solar energy, and by the positive attributes of PV - modest environmental impacts, avoidance of fuel price risks, coincidence with peak electrical demand, and the location of PV at the point of use. Given the …
Date: October 5, 2009
Creator: Barbose, Galen L.; Wiser, Ryan; Peterman, Carla & Darghouth, Naim
Object Type: Report
System: The UNT Digital Library
Oregon Wildlife Planning Coordination Project, October 1, 1998 to September 30, 1999 Annual Report. (open access)

Oregon Wildlife Planning Coordination Project, October 1, 1998 to September 30, 1999 Annual Report.

The intent of the Oregon Wildlife Planning Coordination project is to fund Oregon Department of Fish and Wildlife (ODFW) staff to facilitate wildlife mitigation coordination and planning between Oregon wildlife managers. The primary goal of ODFW wildlife mitigation planning/coordination staff is to foster, facilitate, and manage a statewide cooperative wildlife mitigation planning and implementation effort between the Oregon wildlife managers (the Oregon Wildlife Coalition or OWC) to mitigate for wildlife losses in Oregon caused by the development and operation of the hydropower system.
Date: October 5, 1999
Creator: Barnes, Susan P.
Object Type: Report
System: The UNT Digital Library
Automated saturated standard cell intercomparison (open access)

Automated saturated standard cell intercomparison

A cost effective, highly efficient, and automatic method of intercomparing standard cells has been sought after and implemented, utilizing computer control and a commercially available scanner. This system reduces intercomparison time from 4 hours to 30 minutes using the standard National Bureau of Standard (NBS) 4 x 4 design. 7 figs., 1 tab.
Date: October 5, 1987
Creator: Bell, B. E. & Deitesfeld, C. A.
Object Type: Report
System: The UNT Digital Library
Theoretical studies involving candidate VIA laser systems (open access)

Theoretical studies involving candidate VIA laser systems

Theoretical studies supporting the Livermore photolytic Group VIA laser project were initiated early in 1977. Results of numerous theoretical studies which deal with the photolysis process, losses in the upper laser level and the photolytic pumps are described. Results of ab initio calculations on OCS have been used to assign the electronic states and to analyze the photolysis process. Photoionization cross sections of the upper laser level have been calculated for O(/sup 1/S), S(/sup 1/S) and Se(/sup 1/S). Potential curves of S/sub 2//sup +/ have been determined in the search for possible quenching processes of the upper state. Besides determining ab initio potential energy curves of rare-gas excimer pumps we have also determined photoionization cross sections of the excimer states.
Date: October 5, 1977
Creator: Bender, C.; Hazi, A.; Orel, A.; Rescigno, T. & Winter, N.
Object Type: Article
System: The UNT Digital Library
High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology (open access)

High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.
Date: October 5, 2012
Creator: Bernacki, Bruce E.
Object Type: Report
System: The UNT Digital Library
Hanford Site pollution prevention progress report (open access)

Hanford Site pollution prevention progress report

The Richland Operations Office (RL) and Office of River Protection (ORP) are pleased to issue the attached Pollution Prevention Progress Report. We have just met the most aggressive waste reduction and A recycling goals to date and are publishing this report to recognize A the site's progress, and to ensure it will sustain success beyond 1 Fiscal Year 2000. This report was designed to inform the been made by RL and ORP in Waste Minimization (WMin) and Pollution Prevention (P2). RL, ORP and their contractors are committed to protecting the environment, and we reiterate pollution prevention should continue to be at the forefront of the environmental cleanup and research efforts. As you read the attached report, we believe you will see a clear demonstration of RL and ORP's outstanding performance as it has been responsible and accountable to the nation, its employees, and the community in which we live and work. commitment that all employees have for environmental stewardship. The report provides useful information about the U.S. Department of Energy's (DOE'S) environmental policy and programs, and contains countless examples of waste minimization projects. This year was the first year our site received the White House Closing the Circle in the …
Date: October 5, 1999
Creator: Betsch, M. D.
Object Type: Report
System: The UNT Digital Library
Examination of yield determination by the Magnetic Bubble Effect (open access)

Examination of yield determination by the Magnetic Bubble Effect

This report surveys the preliminary work of P. J. Ebert, a proponent of the Magnetic Bubble'' Effect, as well as conclusions reached by L. F. Wouters and others. The idea behind the Magnetic Bubble Effect is that an exploding fireball from a surface or subsurface nuclear explosion releases electrons which circulate around the earth's magnetic field lines and create an expanding magnetic dipole which persists underground for {approx equal}0.01 sec. This dipole radiates a low-frequency electromagnetic field through the earth in a diffusive manner because the earth's conduction current overwhelms the displacement current at VLF and ELF frequencies. By using this concept of diffusive fields it might be possible to estimate the yield of an underground nuclear test from transient low-frequency field measurements on or near the ground in the range 1--5km from ground zero. We closely examine the diffusive-field description of the transient fields by L. W. Miller. Miller's work enables us to derive rather easily the Green-function'' fields in space and time of a spatially and temporally impulsive vertical magnetic dipole, m{sub z}, and horizontal dipole, m{sub x}, in a homogeneous earth of scalar electrical conductivity {sigma}, magnetic permeability {mu}{sub 0}, and relative dielectric constant, {var epsilon}{sub r}, …
Date: October 5, 1990
Creator: Bevensee, R.M.
Object Type: Report
System: The UNT Digital Library
Release of HWVP design media (open access)

Release of HWVP design media

Late in 1993 the Hanford Waste Vitrification Plant (HWVP) Project was given direction by the US Department of Energy (DOE), Richland Operations Office (RL) to defer design activities on the project. As a result of this direction, detailed design work on most structures was stopped and the design information was stored. Design and construction work was carried to completion on a few of the HWVP packages. The packages that were carried to completion are the subject of this work plan.
Date: October 5, 1994
Creator: Bevins, R. R.
Object Type: Report
System: The UNT Digital Library