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Updating the Nrc Guidance for Human Factors Engineering Reviews. (open access)

Updating the Nrc Guidance for Human Factors Engineering Reviews.

None
Date: September 15, 2002
Creator: O Hara, J. M.; Brown, W. S.; Higgins, J. C.; Persensky, J. J.; Lewis, P. M. & Bongarra, J.
System: The UNT Digital Library
On-Line Microbial Whole Effluent Toxicity Monitoring for Industrial Wastewater (open access)

On-Line Microbial Whole Effluent Toxicity Monitoring for Industrial Wastewater

In this study a respirometer is tested for its ability to act as an early upset warning device and whole effluent toxicity monitor for industrial discharge. Industrial discharge water quality is commonly evaluated by comparing measured chemical concentrations to target values or regulatory limits established by governmental agencies. Unless the regulatory values are based upon empirical data, the actual effect of the discharge on aquatic systems is unknown. At the same time assessing the environmental toxicology of wastewater discharges is complicated by synergistic relationships among chemical constituents producing greater total toxicity. For example, metals may be more toxic in waters with low total hardness or more soluble at lower pH. An alternative approach that we are investigating is whole effluent toxicity testing. This study investigates the measurement of whole effluent toxicity through an on-line respirometer that measures toxicity to microorganisms comprising activated sludge. In this approach the oxygen uptake rate is monitored and used as an indicator of microbial activity or health. This study investigates the use of an online whole effluent toxicity testing system to provide early upset warning and the consistency of measured response to low pH. Repeated exposure of the microorganisms to low pH results in reduced …
Date: September 17, 2002
Creator: Mathews, S; Hoppes, W; Mascetti, M & Campbell, C G
System: The UNT Digital Library
Influence of Environmental Variables on the Susceptibility of Alloy 22 to Environmentally Assisted Cracking (open access)

Influence of Environmental Variables on the Susceptibility of Alloy 22 to Environmentally Assisted Cracking

In its current design, the high-level nuclear waste containers include an external layer of Alloy 22 (NO6022). This material was selected to provide long-term corrosion resistance since if water enters in contact with the containers, they may undergo corrosion. The model for the degradation of the containers includes three modes of corrosion, namely general corrosion, localized corrosion and environmentally assisted cracking (EAC). The objective of the current research was to quantify the susceptibility of Alloy 22 to EAC in several environmental conditions with varying solution composition, temperature and electrochemical potential. The susceptibility to EAC was evaluated using constant deformation (deflection) U-bend specimens in both the wrought and welded conditions. Results show that after more than five years exposure in the vapor and liquid phases of alkaline (PH {approx} 10) and acidic (pH {approx} 3) multi-ionic environments at 60 C and 90 C, Alloy 22 was free from EAC.
Date: September 26, 2002
Creator: Fix, D. V.; Estill, J. C.; King, K. J.; Day, S. D. & Rebak, R. B.
System: The UNT Digital Library
NEW RESULTS FROM THE MUON G - 2 EXPERIMENT. (open access)

NEW RESULTS FROM THE MUON G - 2 EXPERIMENT.

The Muon g-2 collaboration has measured the anomalous magnetic g value, a = (g-2)/2, of the positive muon with an unprecedented uncertainty of O.7parts per million. The result a{sub {mu}{sup +}}(expt) = 11 659 204(7)(5) x 10{sup -10}, based on data collected in the year 2000 at Brookhaven National Laboratory, is in good agreement with the preceding data on a{sub {mu}{sup +}} and a{sub {mu}{sup -}}. The measurement tests standard model theory, which at the level of the current experimental uncertainty involves quantum electrodynamics, quantum chromodynamics, and electroweak interaction in a significant way.
Date: September 9, 2002
Creator: SICHTERMANN,E. P. BENNETT,G. W. BOUSQUET,B. BROWN,H. N. BUNCE,G. CAREY,R. M. ET ALMUON G - 2 COLLABORATION
System: The UNT Digital Library
RHIC PC CNI Polarimeter:Status and Performance From the First Collider Run. (open access)

RHIC PC CNI Polarimeter:Status and Performance From the First Collider Run.

Polarimeters using the proton carbon elastic scattering process in Coulomb Nuclear Interference (CNI) region were installed in two RHIC rings. Polarization measurements were successfully carried out with the high energy polarized proton beams for the first polarized pp collision run. The physics principles, performance, and polarization measurements are presented.
Date: September 9, 2002
Creator: Jinnouchi, O.; Bland, L. C.; Bravar, A.; Bunce, G.; Cadman, R.; Deshpande, A. D. et al.
System: The UNT Digital Library
THE RELATIVISTIC STERN GERLACH INTERACTION AS A TOOL FOR ATTAINING THE SPIN SEPARATION. (open access)

THE RELATIVISTIC STERN GERLACH INTERACTION AS A TOOL FOR ATTAINING THE SPIN SEPARATION.

The relativistic Stem-Gerlach interaction is here considered as a tool for obtaining the spin state separation of an unpolarized (anti)proton beam circulating in a ring. Drawbacks, such as spin precessions within the TE rf cavity, spurious kicks due to the transverse electric field and, worst of all, filamentation in the longitudinal phase plane are analyzed. Possible remedies are proposed and their feasibility is discussed.
Date: September 9, 2002
Creator: CAMERON,P. CONTE,M. LUCCIO,A. U. MACKAY,W. W. PALAZZI,M. PUSTERLA,M.
System: The UNT Digital Library
Proceedings of the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration (open access)

Proceedings of the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration

These proceedings contain papers prepared for the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration, held 17-19 September, 2002 in Ponte Vedra Beach, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 17, 2002
Creator: Warren, N. Jill
System: The UNT Digital Library
Evaluation of a semi-implicit numerical algorithm for a rate-dependent ductile failure model. (open access)

Evaluation of a semi-implicit numerical algorithm for a rate-dependent ductile failure model.

A survey conducted in the mid-80's revealed that the mathematical descriptions of ductile fracture tended to apply to either tensile tests or spa11 tests. The objective behind the development of the TEPLA was then a unification of these disparate phenomena into a single model.
Date: September 1, 2002
Creator: Zocher, M. A. (Marvin Anthony); Zuo, Q. K. (Qiuhai K.) & Mason, T. A. (Thomas A.)
System: The UNT Digital Library
A dynamic kernel modifier for linux (open access)

A dynamic kernel modifier for linux

Dynamic Kernel Modifier, or DKM, is a kernel module for Linux that allows user-mode programs to modify the execution of functions in the kernel without recompiling or modifying the kernel source in any way. Functions may be traced, either function entry only or function entry and exit; nullified; or replaced with some other function. For the tracing case, function execution results in the activation of a watchpoint. When the watchpoint is activated, the address of the function is logged in a FIFO buffer that is readable by external applications. The watchpoints are time-stamped with the resolution of the processor high resolution timers, which on most modem processors are accurate to a single processor tick. DKM is very similar to earlier systems such as the SunOS trace device or Linux TT. Unlike these two systems, and other similar systems, DKM requires no kernel modifications. DKM allows users to do initial probing of the kernel to look for performance problems, or even to resolve potential problems by turning functions off or replacing them. DKM watchpoints are not without cost: it takes about 200 nanoseconds to make a log entry on an 800 Mhz Pentium-Ill. The overhead numbers are actually competitive with other …
Date: September 3, 2002
Creator: Minnich, R. G. (Ronald G.)
System: The UNT Digital Library
Conservation in California during the summer of 2001 (open access)

Conservation in California during the summer of 2001

The goal of this study is to measure the results of energy-conservation, energy-efficiency, and load-reduction measures in the California Independent System Operator (CAISO) region during the summer of 2001. During the period leading up to summer 2001, California experienced power outages and unprecedented instability in electricity and natural gas markets. Expecting that warm summer temperatures would exacerbate the already unstable energy market, state agencies and utilities created conservation and load-reduction programs that included advertisements and publicity, bill discounts for decreased customer electricity use, and financial payments for real-time load interruptions. Because the state avoided major electricity grid disturbances during the summer, few of the load-reduction programs were tested; however, the conservation and energy-efficiency programs appear to have been quite effective. The purpose of this study is to determine the extent to which electricity loads decreased in summer 2001 relative to summer 2000 and summer 1999, independent of differences in weather patterns. Our assumption is that the portion of load reduction that is not attributable to weather can be attributed to energy-efficiency and conservation measures. To determine the load reduction, we adjusted year 1999 and year 2000 hourly loads to simulate what load would have been under year 2001 weather conditions …
Date: September 1, 2002
Creator: Bartholomew, Emily S.; Van Buskirk, Robert D. & Marnay, Chris
System: The UNT Digital Library
RELAP5-3D User Problems (open access)

RELAP5-3D User Problems

The Reactor Excursion and Leak Analysis Program with 3D capability1 (RELAP5-3D) is a reactor system analysis code that has been developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the U. S. Department of Energy (DOE). The 3D capability in RELAP5-3D includes 3D hydrodynamics2 and 3D neutron kinetics3,4. Assessment, verification, and validation of the 3D capability in RELAP5-3D is discussed in the literature5,6,7,8,9,10. Additional assessment, verification, and validation of the 3D capability of RELAP5-3D will be presented in other papers in this users seminar. As with any software, user problems occur. User problems usually fall into the categories of input processing failure, code execution failure, restart/renodalization failure, unphysical result, and installation. This presentation will discuss some of the more generic user problems that have been reported on RELAP5-3D as well as their resolution.
Date: September 1, 2002
Creator: Riemke, Richard Allan
System: The UNT Digital Library
Titanium metal: extraction to application (open access)

Titanium metal: extraction to application

In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.
Date: September 1, 2002
Creator: Gambogi, Joseph & Gerdemann, Stephen J.
System: The UNT Digital Library
Communicating the Future: Best Practices for Communication of Science and Technology to the Public (open access)

Communicating the Future: Best Practices for Communication of Science and Technology to the Public

To advance the state of the art in science and technology communication to the public a conference was held March 6-8, 2002 at the National Institute of Standards and Technology in Gaithersburg, MD. This report of the conference proceedings includes a summary statement by the conference steering committee, transcripts or other text summarizing the remarks of conference speakers, and abstracts for 48 "best practice" communications programs selected by the steering committee through an open competition and a formal peer review process. Additional information about the 48 best practice programs is available on the archival conference Web site at www.nist.gov/bestpractices.
Date: September 30, 2002
Creator: Porter, Gail
System: The UNT Digital Library
Linkage and association of haplotypes at the APOA1/C3/A4/A5 genecluster to familial combined hyperlipidemia (open access)

Linkage and association of haplotypes at the APOA1/C3/A4/A5 genecluster to familial combined hyperlipidemia

Combined hyperlipidemia (CHL) is a common disorder of lipidmetabolism that leads to an increased risk of cardiovascular disease. Thelipid profile of CHL is characterised by high levels of atherogeniclipoproteins and low levels of high-density-lipoprotein-cholesterol.Apolipoprotein (APO) A5 is a newly discovered gene involved in lipidmetabolism located within 30kbp of the APOA1/C3/A4 gene cluster. Previousstudies have indicated that sequence variants in this cluster areassociated with increased plasma lipid levels. To establish whethervariation at the APOA5 gene contributes to the transmission of CHL, weperformed linkage and linkage disequilibrium (LD) tests on a large cohortof families (n=128) with familial CHL (FCHL). The linkage data producedevidence for linkage of the APOA1/C3/A4/A5 genomic interval to FCHL (NPL= 1.7, P = 0.042). The LD studies substantiated these data. Twoindependent rare alleles, APOA5c.56G and APOC3c.386G of this gene clusterwere over-transmitted in FCHL (P = 0.004 and 0.007, respectively), andthis was associated with a reduced transmission of the most commonAPOA1/C3/A4/A5 haplotype (frequency 0.4425) to affected subjects (P =0.013). The APOA5c.56G allele was associated with increased plasmatriglyceride levels in FCHL probands, whereas the second, andindependent, APOC3c.386G allele was associated with increased plasmatriglyceride levels in FCHL pedigree founders. Thus, this allele (or anallele in LD) may mark a quantitative trait associated …
Date: September 15, 2002
Creator: Eichenbaum-Voline, Sophie; Olivier, Michael; Jones, Emma L.; Naoumova, Rossitza P.; Jones, Bethan; Gau, Brian et al.
System: The UNT Digital Library
Trace Elements and Common Ions in Southeastern Idaho Snow: Regional Air Pollutant Tracers for Source Area Emissions (open access)

Trace Elements and Common Ions in Southeastern Idaho Snow: Regional Air Pollutant Tracers for Source Area Emissions

Snow samples were collected in southeastern Idaho over two winters to assess trace elements and common ions concentrations in air pollutant fallout across the region. The objectives were to: 1) develop sampling and analysis techniques that would produce accurate measurements of a broad suite of elements and ions in snow, 2) identify the major elements in regional fallout and their spatial and temporal trends, 3) determine if there are unique combinations of elements that are characteristic to the major source areas in the region (source profiles), and 4) use pattern recognition and multivariate statistical techniques (principal component analysis and classical least squares regression) to investigate source apportionment of the fallout to the major source areas. In the winter of 2000-2001, 250 snow samples were collected across the region over a 4-month period and analyzed in triplicate using inductively-coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC). Thirty-nine (39) trace elements and 9 common ions were positively identified in most samples. The data were analyzed using pattern recognition tools in the software, Pirouette® (Infometrix, Inc.). These results showed a large crustal component (Al, Zn, Mn, Ba, and rare earth elements), an overwhelming contribution from phosphate processing facilities located outside Pocatello in …
Date: September 1, 2002
Creator: Abbott, Michael Lehman; Einerson, Jeffrey James; Schuster, Paul & Susong, David D.
System: The UNT Digital Library
A High-Resolution Aeromagnetic Survey to Identify Buried Faults at Dixie Valley, Nevada (open access)

A High-Resolution Aeromagnetic Survey to Identify Buried Faults at Dixie Valley, Nevada

Preliminary results from a high-resolution aeromagnetic survey (200m line spacing) acquired in Dixie Valley early in 2002 provide confirmation of intra-basin faulting based on subtle surface indications. In addition the data allow identification of the locations and trends of many faults that have not been recognized at the surface, and provide a picture of intrabasin faulting patterns not possible using other techniques. The data reveal a suite of northeasterly-trending curving and branching faults that surround a relatively coherent block in the area of Humboldt Salt Marsh, the deepest part of the basin. The producing reservoir occurs at the north end of this coherent block, where rampart faults from the northwest side of the valley merge with anthithetic faults from the central and southeast parts of the valley.
Date: September 1, 2002
Creator: Smith, Richard Paul; Grauch, V. J. S. & Blackwell, David D.
System: The UNT Digital Library
Progress in Compact Toroid Experiments (open access)

Progress in Compact Toroid Experiments

The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.
Date: September 1, 2002
Creator: Dolan, Thomas James
System: The UNT Digital Library
A concentration rebound method for measuring particle penetrationand deposition in the indoor environment (open access)

A concentration rebound method for measuring particle penetrationand deposition in the indoor environment

Continuous, size resolved particle measurements were performed in two houses in order to determine size-dependent particle penetration and deposition in the indoor environment. The experiments consisted of three parts: (1) measurement of the particle loss rate following artificial elevation of indoor particle concentrations, (2) rapid reduction in particle concentration through induced ventilation by pressurization of the houses with HEPA-filtered air, and (3) measurement of the particle concentration rebound after house pressurization stopped. During the particle concentration decay period, when indoor concentrations are very high, losses due to deposition are large compared to gains due to particle infiltration. During the concentration rebound period, the opposite is true. The large variation in indoor concentration allows the effects of penetration and deposition losses to be separated by the transient, two-parameter model we employed to analyze the data. We found penetration factors between 0.3 and 1 and deposition loss rates between 0.1 and 5 h{sup -1}, for particles between 0.1 and 10 {micro}m.
Date: September 1, 2002
Creator: tlthatcher@lbl.gov
System: The UNT Digital Library
Macroparticle simulation studies of a proton beam haloexperiment (open access)

Macroparticle simulation studies of a proton beam haloexperiment

We report macroparticle simulations for comparison withmeasured results from a proton beam-halo experiment in a 52-quadrupoleperiodic-focusing channel. An important issue is that the inputphase-space distribution is not experimentally known. Three differentinitial distributions with different shapes predict different beamprofiles in the transport system. Simulations have been fairly successfulin reproducing the core of the measured matched-beam profiles and thetrend of emittance growth as a function of mismatch factor, butunderestimate the growth rate of halo and emittance for mismatched beams.In this study, we find that knowledge of the Courant-Snyder parametersand emittances of the input beam is not sufficient for reliableprediction of the halo. Input distributions iwth greater population inthe tails produce larger rates of emittance growth, a result that isqualitatively consistent with the particle-core model of halo formationin mismatched beams.
Date: September 12, 2002
Creator: Qiang, J.; Colestock, P. L.; Gilpatrick, D.; Smith, H. V.; Wangler, T. P. & Schulze, M. E.
System: The UNT Digital Library
The Science of Climate Change (open access)

The Science of Climate Change

What constitutes 'dangerous anthropogenic interference' is a value judgment arrived at through a socio-political process, taking issues like equity and sustainability into account. Science provides key information needed to arrive at an informed judgment. However, that judgment is primarily a political one, and not a purely scientific decision. Such judgments are based on risk assessment, and lead to risk management choices by decision makers, about actions and policies.
Date: September 20, 2002
Creator: Makundi, Willy R.
System: The UNT Digital Library
Ion energy distribution functions of vacuum arc plasmas (open access)

Ion energy distribution functions of vacuum arc plasmas

The velocity distribution function of vacuum arc ions can be measured by a time-of-flight technique similar to a method originally proposed by Yushkov. The measuring principle makes use of the well-justified assumption that the ion drift velocity from the cathode spot region to a collector is approximately constant. It is shown that the negative time derivative of the collector current is directly proportional to the ion distribution function provided that the time-averaged source intensity (i.e., emission of ions from cathode spots) is constant until the arc is rapidly switched off. In the experiment, arc termination took about 700 ns, which is much faster than the decay of the ion current measured at the collector placed in more than 2 meters distance from the cathode. The experimental distribution functions for most cathode materials show one large peak with a tail and one or more small peaks at higher ion velocities. The distribution functions for some other materials exhibit several peaks. No conclusive answer can be given about the nature of these peaks. Arguments are presented that the peaks are not caused by different charge states or plasma contamination but rather due to insufficiently averaged source fluctuations and/or acceleration by plasma instabilities.
Date: September 16, 2002
Creator: Byon, Eungsun & Anders, Andre
System: The UNT Digital Library
High-Frequency and Very-high-Frequency (HF&VHF) above-groundelectromagnetic impedance measurements (open access)

High-Frequency and Very-high-Frequency (HF&VHF) above-groundelectromagnetic impedance measurements

We have field-tested an apparatus for measuring the electromagnetic impedance above the ground at a plurality of frequencies in the 0.3 - 30 MHz range. This window in the frequency spectrum, which lies between frequencies used for GPR and those used for conventional loop-loop EM soundings, has not been used because of difficulties in fielding equipment for making absolute and accurate measurements. Model and physical parameter studies however confirm that data in this frequency band can be used to construct high-resolution maps of electrical conductivity and permittivity of near-surface material. Our equipment was assembled using commercial electric and magnetic antennas. The magnetic loop source is excited by a conventional signal generator - power amplifier assembly. Signal detection is accomplished using RF lock-in amplifiers. All system elements are appropriately isolated by optic - fiber links. We estimate a measurement accuracy of about {+-} 10% for an 8-m separation between source and detector. Field tests were done at the University of California Richmond Field Station where the near surface electrical structure is well known. The experimental data at this site are mainly a function of electrical conductivity. In this context, we have obtained good agreement with the known local variations in resistivity …
Date: September 20, 2002
Creator: Frangos, William; Becker, Alex & Lee, K. H.
System: The UNT Digital Library
Apolipoprotein A5: A newly identified gene impacting plasmatriglyceride levels in humans and mice (open access)

Apolipoprotein A5: A newly identified gene impacting plasmatriglyceride levels in humans and mice

Apolipoprotein A5 (APOA5) is a newly described member of theapolipoprotein gene family whose initial discovery arose from comparativesequence analysis of the mammalian APOA1/C3/A4 gene cluster. Functionalstudies in mice indicated that alteration in the level of APOA5significantly impacted plasma triglyceride concentrations. Miceover-expressing human APOA5 displayed significantly reducedtriglycerides, while mice lacking apoA5 had a large increase in thislipid parameter. Studies in humans have also suggested an important rolefor APOA5 in determining plasma triglyceride concentrations. In theseexperiments, polymorphisms in the human gene were found to define severalcommon haplotypes that were associated with significant changes intriglyceride concentrations in multiple populations. Several separateclinical studies have provided consistent and strong support for theeffect with 24 percent of Caucasians, 35 percent of African-Americans and53 percent of Hispanics carrying APOA5 haplotypes associated withincreased plasma triglyceride levels. In summary, APOA5 represents anewly discovered gene involved in triglyceride metabolism in both humansand mice whose mechanism of action remains to be deciphered.
Date: September 15, 2002
Creator: Pennacchio, Len A. & Rubin, Edward M.
System: The UNT Digital Library
Lethality in PARP-1/Ku80 double mutant mice reveals physiologicalsynergy during early embryogenesis (open access)

Lethality in PARP-1/Ku80 double mutant mice reveals physiologicalsynergy during early embryogenesis

Ku is an abundant heterodimeric nuclear protein, consisting of 70-kDa and 86-kDa tightly associated subunits that comprise the DNA binding component of DNA-dependent protein kinase. Poly(ADP)ribose polymerase-1 (PARP-1) is a 113-kDa protein that catalyzes the synthesis of poly(ADP-ribose) on target proteins. Both Ku and PARP-1 recognize and bind to DNA ends. Ku functions in the non-homologous end joining (NHEJ) repair pathway whereas PARP-1 functions in the single strand break repair and base excision repair (BER) pathways. Recent studies have revealed that PARP-1 and Ku80 interact in vitro. To determine whether the association of PARP-1 and Ku80 has any physiological significance or synergistic function in vivo, mice lacking both PARP-1 and Ku80 were generated. The resulting offspring died during embryonic development displaying abnormalities around the gastrulation stage. In addition, PARP-1-/-Ku80-/- cultured blastocysts had an increased level of apoptosis. These data suggest that the functions of both Ku80 and PARP-1 are essential for normal embryogenesis and that a loss of genomic integrity leading to cell death through apoptosis is likely the cause of the embryonic lethality observed in these mice.
Date: September 24, 2002
Creator: Henrie, Melinda S.; Kurimasa, Akihiro; Burma, Sandeep; Menissier-de Murcia, Josiane; de Murcia, Gilbert; Li, Gloria C. et al.
System: The UNT Digital Library