Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components (open access)

Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components

Laser safety evaluation and output emission measurements were performed (during October and November 2001) on SNL MILES and Mini MILES laser emitting components. The purpose, to verify that these components, not only meet the Class 1 (eye safe) laser hazard criteria of the CDRH Compliance Guide for Laser Products and 21 CFR 1040 Laser Product Performance Standard; but also meet the more stringent ANSI Std. z136.1-2000 Safe Use of Lasers conditions for Class 1 lasers that govern SNL laser operations. The results of these measurements confirmed that all of the Small Arms Laser Transmitters, as currently set (''as is''), meet the Class 1 criteria. Several of the Mini MILES Small Arms Transmitters did not. These were modified and re-tested and now meet the Class 1 laser hazard criteria. All but one System Controllers (hand held and rifle stock) met class 1 criteria for single trigger pulls and all presented Class 3a laser hazard levels if the trigger is held (continuous emission) for more than 5 seconds on a single point target. All units were Class 3a for ''aided'' viewing. These units were modified and re-tested and now meet the Class 1 hazard criteria for both ''aided'' as well as ''unaided'' …
Date: February 2, 2002
Creator: AUGUSTONI, ARNOLD L.
Object Type: Report
System: The UNT Digital Library
Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev (open access)

Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev

The Standard Model predictions for W{gamma} and Z{gamma} production are tested using an integrated luminosity of 200 pb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E{sub T} > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W{gamma} and Z{gamma} data are compared to SM predictions.
Date: February 2, 2005
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library

2008 B20 Survey Results

Describes results of a sample survey of the quality of B20, a biodiesel blend, collected from U.S. public pumps and fleets as part of a joint effort by NREL, the NBB, and engine manufacturers.
Date: February 2, 2009
Creator: Alleman, T. L. & McCormick, R. L.
Object Type: Presentation
System: The UNT Digital Library
MOSAIC: a new wavefront metrology (open access)

MOSAIC: a new wavefront metrology

MOSAIC is a new wavefront metrology that enables complete wavefront characterization from print or aerial image based measurements. Here we describe MOSAIC and verify its utility with a model-based proof of principle.
Date: February 2, 2009
Creator: Anderson, Christopher & Naulleau, Patrick
Object Type: Article
System: The UNT Digital Library
Femtosecond, High-Brightness Electron Beam Generation and Advanced Diagnosis (open access)

Femtosecond, High-Brightness Electron Beam Generation and Advanced Diagnosis

This document serves as the final report for LDRD project number 04-LW-031, in which we created subpicosecond length, kilo-amp peak current electron beams with the 100 MeV electron/positron linac, using a novel technique designed to produce ultra-short bunch lengths while maintaining the high brightness produced by the S-band photoinjector. In addition, a diagnostic to measure the temporal distribution of the beam was investigated, as conventional pulse length measurement techniques do not apply to extremely short pulses. The creation and diagnosis of beams with both femtosecond length and high transverse brightness is of major concern to next generation acceleration and radiation production experiments. This work leveraged the previous investment in the PLEIADES facility and it's ability to produce high brightness electron beams. In addition, the ultra-short electron pulses generated by this work have been used in conjunction with the PLEIADES X-ray source to produce sub-picosecond, high-brightness X-ray pulses.
Date: February 2, 2005
Creator: Anderson, S G; Brown, W J; Tremaine, A M; Kuba, J; Hartemann, F V & Fittinghoff, D N
Object Type: Report
System: The UNT Digital Library
Exploring little Higgs models with ATLAS at the LHC (open access)

Exploring little Higgs models with ATLAS at the LHC

We discuss possible searches for the new particles predicted by Little Higgs Models at the LHC. By using a simulation of the ATLAS detector, we demonstrate how the predicted quark, gauge bosons and additional Higgs bosons can be found and estimate the mass range over which their properties can be constrained.
Date: February 2, 2004
Creator: Azuelos, G.; Benslama, K.; Costanzo, D.; Couture, G.; Garcia, J.E.; Hinchliffe, I.G. et al.
Object Type: Article
System: The UNT Digital Library
Conceptual Models of Flow through a Heterogeneous, Layered Vadose Zone under a Percolation Pond (open access)

Conceptual Models of Flow through a Heterogeneous, Layered Vadose Zone under a Percolation Pond

Understanding how water and solutes move through the vadose zone is necessary to make effective remedial action decisions where contaminants were spilled or leaked at the ground surface or were buried in shallow land-disposal sites. In layered, heterogeneous systems, high contrasts in hydraulic conductivity can lead to formation of perched water zones, and enhanced lateral spread of contamination. Two conceptual models are considered solute for migration through the vadose zone. In the diffuse flow conceptual model, perched water zones accumulate until the head over the perching layer becomes sufficient to drive the infiltration through the perching layer. In the preferential flow conceptual model, perched water moves laterally until a path around the perching layer is encountered. Preferential flow paths can enhance contaminant migration because greater moisture saturation leads to higher advective velocities, and the preferential flow paths bypass low permeability layers with higher sorption capacity. Monitoring wells and instrumented boreholes were installed around a newly constructed industrial-waste percolation pond and an ephemeral river that lie over a 150-m-thick layered vadose zone. Background data gathered before discharge to the pond began show the presence of at least one, and possibly two, deep perched zones. The shallower zone, at approximately 45-m below …
Date: February 2, 2004
Creator: Baker, Kristine; Hull, Larry; Bennett, Jesse; Ansley, Shannon & Heath, Gail
Object Type: Report
System: The UNT Digital Library
Group Representations and Multinomial Combinatorics of the Icosahedral Symmetry (open access)

Group Representations and Multinomial Combinatorics of the Icosahedral Symmetry

The icosahedral symmetry is one of the most intriguing symmetries, as it not only presents challenge but it appears in many fullerenes and high energetic materials such as the dodecahedral N{sub 20}. We have considered the combinatorics of all irreducible representations of the icosahedral symmetry for a number of multinomial partitions for vertex, face and edge colorings in this work. We have constructed the combinatorial tables for all irreducible representations for various multinomial partitions of colorings for the vertices, edge and faces of the icosahedron. These techniques should have important applications to enumerations and spectroscopy of fullerenes and high-energy materials such as N{sub 20}.
Date: February 2, 2004
Creator: Balasubramanian, K
Object Type: Article
System: The UNT Digital Library
Non-rigid Group Theory, Tunneling Splittings and Nuclear Spin Statistics of Water Pentamer: (H2O5) (open access)

Non-rigid Group Theory, Tunneling Splittings and Nuclear Spin Statistics of Water Pentamer: (H2O5)

The character table of the fully non-rigid water pentamer, (H{sub 2}O){sub 5} is derived for the first time. The group of all feasible permutations is the wreath product group S{sub 5}[S{sub 2}] and it consists of 3840 operations divided into 36 conjugacy classes and irreducible representations. We have shown that the full character table can be constructed using elegant matrix type generator algebra. The character table has been applied to the water pentamer by obtaining the nuclear spin statistical weights of the rovibronic levels and tunneling splittings of the fully non-rigid pentamer. We have also obtained the statistical weights and tunneling splittings of a semi-rigid deuterated pentamer that exhibits pseudo rotation with an averaged C{sub 5h}(G{sub 10}) symmetry used in the assignment of vibration-rotation-tunneling spectra . The correlation tables have been constructed for the semirigid (G{sub 10}) to non-rigid (G{sub 3840}) groups for the rotational levels and tunneling levels. The nuclear spin statistical weights have also been derived for both the limits.
Date: February 2, 2004
Creator: Balasubramanian, K
Object Type: Article
System: The UNT Digital Library
Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks (open access)

Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks

Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO{sub 2}B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for {approx} 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg {sup -1} and maximum values of {approx} 10 g kg{sup -1}. Corresponding values for PN emission factors were 4.7 x 10{sup 15} and 4 x 10{sup 16} kg{sup -1}. There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1{sigma}) …
Date: February 2, 2009
Creator: Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W. & Harley, Robert A.
Object Type: Article
System: The UNT Digital Library
Knowledge Representation Issues in Semantic Graphs for Relationship Detection (open access)

Knowledge Representation Issues in Semantic Graphs for Relationship Detection

An important task for Homeland Security is the prediction of threat vulnerabilities, such as through the detection of relationships between seemingly disjoint entities. A structure used for this task is a ''semantic graph'', also known as a ''relational data graph'' or an ''attributed relational graph''. These graphs encode relationships as typed links between a pair of typed nodes. Indeed, semantic graphs are very similar to semantic networks used in AI. The node and link types are related through an ontology graph (also known as a schema). Furthermore, each node has a set of attributes associated with it (e.g., ''age'' may be an attribute of a node of type ''person''). Unfortunately, the selection of types and attributes for both nodes and links depends on human expertise and is somewhat subjective and even arbitrary. This subjectiveness introduces biases into any algorithm that operates on semantic graphs. Here, we raise some knowledge representation issues for semantic graphs and provide some possible solutions using recently developed ideas in the field of complex networks. In particular, we use the concept of transitivity to evaluate the relevance of individual links in the semantic graph for detecting relationships. We also propose new statistical measures for semantic graphs …
Date: February 2, 2005
Creator: Barthelemy, M; Chow, E & Eliassi-Rad, T
Object Type: Article
System: The UNT Digital Library
Ferroelectric and piezoelectric properties of MOCVD Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}PbTiO{sub 3} epitaxial thin films (open access)

Ferroelectric and piezoelectric properties of MOCVD Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}PbTiO{sub 3} epitaxial thin films

The authors have grown epitaxial Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} (PMN) and (1-x)(Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3})-x(PBTiO{sub 3})(PMN-PT)thin films by metalorganic chemical vapor deposition at 700 -- 780 C on (100) SrTiO{sub 3} and SrRuO{sub 3}/SrTiO{sub 3} substrates. The zero-bias permittivity and loss measured at room temperature and 10 kHz for 220 nm thick pure PMN films were 900 and 1.5%, respectively. For PMN-PT films the small-signal permittivity ranged from 1000 to 1500 depending on deposition conditions and Ti content; correspondingly low values for the zero-bias dielectric loss between 1 and 5% were determined for all specimens. For PMN-PT with x of approximately 0.30--0.35, polarization hysteresis with P{sub r}{approximately}18{mu}C/cm{sup 2} was obtained. Initial piezoresponse data are discussed.
Date: February 2, 2000
Creator: Baumann, P. K.; Bai, G. R.; Streiffer, S. K.; Ghosh, K.; Auciello, O.; Stemmer, S. et al.
Object Type: Article
System: The UNT Digital Library
Physics of Ultra-Peripheral Nuclear Collisions (open access)

Physics of Ultra-Peripheral Nuclear Collisions

Moving highly-charged ions carry strong electromagnetic fields which act as a field of photons. In collisions at large impact parameters, hadronic interactions are not possible, and the ions interact through photon-ion and photon-photon collisions known as ultra-peripheral collisions (UPC). Hadron colliders like the Relativistic Heavy Ion Collider (RHIC), the Tevatron and the Large Hadron Collider (LHC) produce photonuclear and two-photon interactions at luminosities and energies beyond that accessible elsewhere; the LHC will reach a {gamma}p energy ten times that of the Hadron-Electron Ring Accelerator (HERA). Reactions as diverse as the production of anti-hydrogen, photoproduction of the {rho}{sup 0}, transmutation of lead into bismuth and excitation of collective nuclear resonances have already been studied. At the LHC, UPCs can study many types of ''new physics''.
Date: February 2, 2005
Creator: Bertulani, Carlos A.; Klein, Spencer R. & Nystrand, Joakim
Object Type: Article
System: The UNT Digital Library
An analytical model of nonproportional scintillator light yield in terms of recombination rates (open access)

An analytical model of nonproportional scintillator light yield in terms of recombination rates

This report talks about An analytical model of nonproportional scintillator light yield in terms of recombination rates
Date: February 2, 2009
Creator: Bizarri, Gregory; Moses, William W.; Singh, Jai; Williams, Richard T. & Vasil'ev, Andrey N.
Object Type: Article
System: The UNT Digital Library
Local Physics Basis of Confinement Degradation in JET ELMy H-Mode Plasmas and Implications for Tokamak Reactors (open access)

Local Physics Basis of Confinement Degradation in JET ELMy H-Mode Plasmas and Implications for Tokamak Reactors

First results of gyrokinetic analysis of JET [Joint European Torus] ELMy [Edge Localized Modes] H-mode [high-confinement modes] plasmas are presented. ELMy H-mode plasmas form the basis of conservative performance predictions for tokamak reactors of the size of ITER [International Thermonuclear Experimental Reactor]. Relatively high performance for long duration has been achieved and the scaling appears to be favorable. It will be necessary to sustain low Z(subscript eff) and high density for high fusion yield. This paper studies the degradation in confinement and increase in the anomalous heat transport observed in two JET plasmas: one with an intense gas puff and the other with a spontaneous transition between Type I to III ELMs at the heating power threshold. Linear gyrokinetic analysis gives the growth rate, gamma(subscript lin) of the fastest growing modes. The flow-shearing rate omega(subscript ExB) and gamma(subscript lin) are large near the top of the pedestal. Their ratio decreases approximately when the confinement degrades and the transport increases. This suggests that tokamak reactors may require intense toroidal or poloidal torque input to maintain sufficiently high |gamma(subscript ExB)|/gamma(subscript lin) near the top of the pedestal for high confinement.
Date: February 2, 2001
Creator: Budny, R. V.; Alper, B.; Borba, D.; Cordey, J. G.; Ernst, D. R. & Gowers, C.
Object Type: Report
System: The UNT Digital Library
PFP Emergency Lighting Study (open access)

PFP Emergency Lighting Study

NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergency Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently …
Date: February 2, 2000
Creator: Busch, M. S.
Object Type: Report
System: The UNT Digital Library
Final Report for DOE Support of 5th the International Workshop on Oxide Surfaces (IWOX-V) (open access)

Final Report for DOE Support of 5th the International Workshop on Oxide Surfaces (IWOX-V)

The 5th International Workshop on Oxide Surfaces (IWOX-V) was held at Granlibakken Conference center in Lake Tahoe, CA, January 7-12. The total attendance was ~90. The breakdown of attendees by country is as follows: USA 41 Germany 18 Japan 7 UK 5 Italy 5 France 4 Austria 3 Denmark 3 Cech. Repub. 1 Ireland 1 New Zealand 1 India 1 The technical program included oral sessions on the electronic and magnetic properties of oxide surfaces, surface and interface structure, advances in theory, surface defects, thin film oxides on metals and on oxides, thin film metals on oxides, surface photochemistry, surface reactivity, and interactions with water. Two evening poster sessions had similar themes. As in previous years, the program stimulated significant interest and discussion among the attendees. The local expenses (food and lodging, $918 per person) for eight foreign invited speakers were covered by BES funds. In addition, partial reimbursement for travel ($328 per person) was supported by BES funds for two more foreign invited speakers.
Date: February 2, 2007
Creator: Campbell, Charles T.
Object Type: Report
System: The UNT Digital Library
Computational modeling of alloys at the atomic scale: from ab initio and thermodynamics to radiation-induced heterogeneous precipitation (open access)

Computational modeling of alloys at the atomic scale: from ab initio and thermodynamics to radiation-induced heterogeneous precipitation

We describe the path we are following in the development of a computational approach to simulate radiation damage in FeCr ferritic steels. In these alloys magnetism introduces an anomaly in the heat of formation of the solid solution that has implications on the way excess Cr precipitates in the {alpha}{prime} phase in presence of heterogeneities. These complexities represent a challenge for atomistic (empirical) approaches that we address: (i) by proposing a modified many body potential, (ii) by using a thermodynamic package that determines free energy and phase diagrams, and (iii) by using a displacement Monte Carlo code in the transmutation ensemble that can deal with millions of atoms in parallel computational environments. This approach predicts that grain boundaries, dislocations and free surfaces are not preferential sites for precipitation of {alpha}{prime}.
Date: February 2, 2007
Creator: Caro, A.; Caro, M.; Klaver, P.; Sadigh, B.; Lopasso, E. M. & Srivilliputhur, S. G.
Object Type: Article
System: The UNT Digital Library
Defense Waste Processing Facility (DWPF), Modular CSSX Unit (CSSX), and Waste Transfer Line System of Salt Processing Program (U) (open access)

Defense Waste Processing Facility (DWPF), Modular CSSX Unit (CSSX), and Waste Transfer Line System of Salt Processing Program (U)

All of the waste streams from ARP, MCU, and SWPF processes will be sent to DWPF for vitrification. The impact these new waste streams will have on DWPF's ability to meet its canister production goal and its ability to support the Salt Processing Program (ARP, MCU, and SWPF) throughput needed to be evaluated. DWPF Engineering and Operations requested OBU Systems Engineering to evaluate DWPF operations and determine how the process could be optimized. The ultimate goal will be to evaluate all of the Liquid Radioactive Waste (LRW) System by developing process modules to cover all facilities/projects which are relevant to the LRW Program and to link the modules together to: (1) study the interfaces issues, (2) identify bottlenecks, and (3) determine the most cost effective way to eliminate them. The results from the evaluation can be used to assist DWPF in identifying improvement opportunities, to assist CBU in LRW strategic planning/tank space management, and to determine the project completion date for the Salt Processing Program.
Date: February 2, 2006
Creator: Chang, Robert
Object Type: Article
System: The UNT Digital Library
Recent charm mixing results from BABAR, Belle, and CDF (open access)

Recent charm mixing results from BABAR, Belle, and CDF

A summary of the results of several recent studies of charm mixing is presented. A number of different methods were used, including the measurement of lifetime ratios for final states of different CP, time dependence of wrong-sign hadronic decays, fits to time-dependent Dalitz plots, and searches for wrong-sign semi-leptonic decays. Taken together, they suggest mixing is of order 1%. The status of searches for indirect CP violation is also reported.
Date: February 2, 2009
Creator: Charles, M.J. & /SLAC, /Iowa U.
Object Type: Article
System: The UNT Digital Library
On Resonant Heating Below the Cyclotron Frequency (open access)

On Resonant Heating Below the Cyclotron Frequency

Resonant heating of particles by an electrostatic wave propagating perpendicular to a confining uniform magnetic field is examined. It is shown that, with a sufficiently large wave amplitude, significant perpendicular stochastic heating can be obtained with wave frequency at a fraction of the cyclotron frequency.
Date: February 2, 2001
Creator: Chen, Liu; Lin, Zhihong & White, R.
Object Type: Report
System: The UNT Digital Library
Status and Needs for Tank Isolation System Contingencies at the Oak Ridge National Laboratory (open access)

Status and Needs for Tank Isolation System Contingencies at the Oak Ridge National Laboratory

This document assesses the need for additional tank isolation systems and tooling at the Oak Ridge National Laboratory (ORNL). Locations for future operations at ORNL include the South and North Tank Farms and various Federal Facilities Agreement tanks. The goal of this report is to identify future needs for development of remote tools and systems to isolate inactive waste storage tanks. Remote tools have been developed to support waste-retrieval and tank-isolation operations at the Gunite and Associated Tanks (GAATs) at ORNL. The tools developed for in-tank remote operations include a pipe-cutting tool (a modified band saw), a pipe-cleaning tool (a modified drill with a wire brush), and a pipe plug. A review of the planned future operations revealed several desirable modifications to improve the efficiency, operability, and flexibility of the existing tank-isolation tools. For example, the pipe-cutting tool needs improvements to provide better alignment, a blade-cutting-release device, improved tire replacement, sensors to prevent operation of the saw when the blade stops, blade speed controls, and force feedback sensors. In addition, the need to test the existing pipe plug for use on corroded piping was identified. The pipe plug has been used on only relatively clean in-tank stainless steel (SS) piping …
Date: February 2, 2000
Creator: Chesser, J.B.
Object Type: Report
System: The UNT Digital Library
Nuclear energy plant optimization (NEPO) final scientific/technical report (open access)

Nuclear energy plant optimization (NEPO) final scientific/technical report

The overall objective of this 3 year research program has been to support the aging management programs for LWR reactors through the extended 60-year lifetimes by adding to the knowledge base of irradiation-induced effects on the mechanical properties and cracking resistance of stainless steel (SS) core components. Over the course of this project, efforts have focused on enhancing the understanding of the link between deformation and fracture behavior in work-hardened and irradiated stainless steels. This understanding is achieved through a combination of mechanical testing, microstructural characterization, and development of models to describe the observed behavior. The understanding gained provides a foundation for evaluating the aging behavior of components during in-core service in terms of radiation embrittlement and alloy susceptibility to irradiation assisted stress corrosion cracking (IASCC).
Date: February 2, 2004
Creator: Cole, J. I.; Daum, R. S.; Tsai, H.; Porter, D. L.; Allen, T. R. & Wirth, B. D.
Object Type: Report
System: The UNT Digital Library
Vector Unparticle Contributions to Lepton g-2 (open access)

Vector Unparticle Contributions to Lepton g-2

The generic unparticle propagator may be modified in two ways. Breaking the conformal symmetry effectively adds a mass term to the propagator, while considering vacuum polarization corrections adds a width-like term. Both of these modifications result naturally from the coupling of the unparticle to standard model (SM) fields. We explore how these modifications to the propagator affect the calculation of the lepton anomalous magnetic moment using an integral approximation of the propagator that is accurate for d {approx}< 1.5, where d is the unparticle dimension. We find that for this range of d and various values of the conformal breaking scale {mu}, the value of g-2 calculated when allowing various SM fermions to run in the unparticle self-energy loops does not significantly deviate from the value of g-2 when the width term is ignored. We also investigate the limits on a characteristic mass scale for the unparticle sector as a function of {mu} and d.
Date: February 2, 2009
Creator: Conley, John A. & Gainer, James S.
Object Type: Article
System: The UNT Digital Library