Applications of level structure modeling of odd-odd deformed nuclei (open access)

Applications of level structure modeling of odd-odd deformed nuclei

None
Date: December 4, 1984
Creator: Hoff, R. W.; Gardner, D. G.; Gardner, M. A.; Kern, J.; Piepenbring, R.; Boisson, J. P. et al.
System: The UNT Digital Library
Coexistence of antiferromagnetic order and superconductivity in CeRh[sub 1[minus]x]M[sub x]In[sub 5](M=Ir and Co) (open access)

Coexistence of antiferromagnetic order and superconductivity in CeRh[sub 1[minus]x]M[sub x]In[sub 5](M=Ir and Co)

We report a systematic neutron diffraction study on the coexistence of long-range magnetic order and superconductivity in heavy fermion compounds CeRhl-,M,Ins (M=Ir,Co). In addition to the incommensurate antiferromagnetic component in pure CeRhIn5, new type of antiferromagnetic component is found to concur with appearance of superconductivity in the Ir and Co alloy series. There is no detectable effect of the superconducting transition on magnetic order parameters. We compare those results with similar studies we performed on CeRhIn:, under pressure. We also discuss possible theoretical scenarios.
Date: December 4, 2002
Creator: Llobet-Megias, A. (Anna); Christianson, A. D. (Andrew D.); Bao, W. (Wei); Gardner, J. S.; Pagliuso, P. J. (Pascoal J.); Moreno, N. O. et al.
System: The UNT Digital Library
Polarized proton performance of AGS in run 8 operation (open access)

Polarized proton performance of AGS in run 8 operation

None
Date: May 4, 2009
Creator: Huang, H.; Ahrens, L.; Bai, M.; Brown, K. A.; Gardner, C.; Glenn, J. W. et al.
System: The UNT Digital Library
A Multiplex PCR-coupled Liquid Bead Array for the Simultaneous Detection of Four Biothreat Agents (open access)

A Multiplex PCR-coupled Liquid Bead Array for the Simultaneous Detection of Four Biothreat Agents

We have developed a 10-plexed PCR assay coupled to a 12-plexed liquid bead array to rapidly screen environmental samples for B. anthracis, Y. pestis, F. tularensis, and B. melitensis. Highly validated species -specific primer sets were used to simultaneously amplify multiple diagnostic regions unique to each individual pathogen. Resolution of the mix of amplified products was achieved by PCR product hybridization to corresponding probe sequences, attached to unique sets of fluorescent beads. The hybridized beads were processed through a flow cytometer, which detected presence and quantity of each PCR product. The assay was optimized to allow for maximum sensitivity in a multiplexed format. A high- throughput demonstration was performed where 384 simulated environmental samples were spiked with different amounts of B. thuringensis spores and pathogen DNA. The samples were robotically processed to extract DNA and arrayed for multiplexed PCR-liquid bead detection. The assay correctly identified the presence or absence of each pathogen and collected over 3,000 individual data points within a single 8-hour shift for approximately $1.20 per sample in a 10-plexed assay.
Date: February 4, 2004
Creator: Wilson, W. J.; Erler, A. M.; Nasarabadi, S. L.; Skowronski, E. W. & McCready, P. M.
System: The UNT Digital Library
RHIC Performance for FY2011 Au+Au Heavy Ion Run (open access)

RHIC Performance for FY2011 Au+Au Heavy Ion Run

Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run, RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of 'common' RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals. At the conclusion of the FY 2011 polarized proton run, preparations for heavy ion run proceeded on April 18, with Au+Au collisions continuing through June 28. Our standard operations at 100 GeV/nucleon beam energy was bracketed by two shorter periods of collisions at lower energies (9.8 and 13.5 GeV/nucleon), continuing a previously established program of low and medium energy runs. Table 1 summarizes our history of heavy ion operations at RHIC.
Date: September 4, 2011
Creator: Marr, G.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.; Blaskiewicz, M. et al.
System: The UNT Digital Library
Science and Technology for Bioterrorism Defense (open access)

Science and Technology for Bioterrorism Defense

The Lawrence Livermore National Laboratory (LLNL) Chemical & Biological National Security Program (CBNP) provides science, technology, and integrated systems for chemical and biological security. Our approach is to develop and field systems that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons.
Date: May 4, 2004
Creator: Fitch, J P
System: The UNT Digital Library
Ablative stabilization of the Rayleigh-Taylor instability in regimes relevant to inertial confinement fusion (open access)

Ablative stabilization of the Rayleigh-Taylor instability in regimes relevant to inertial confinement fusion

As shown elsewhere an ablatively imploded shell is hydrodynamically unstable, the dominant instability being the well known Rayleigh-Taylor instability with growth rate {gamma} = {radical}Akg where k = 2{pi}/{lambda} is the wave number, g is the acceleration and A the Attwood number ({rho}{sub hi} {minus} {rho}{sub lo})/({rho}{sub hi} + {rho}{sub lo}) where {rho}{sub hi} is the density of the heavier fluid and {rho}{sub lo} is the density of the lighter fluid. A theoretical understanding of ablative stabilization has gradually evolved, confirmed over the last five years by experiments. The linear growth is very well understood with excellent agreement between experiment and simulation for planar geometry with wavelengths in the region of 30--100{mu}m. There is an accurate, albeit phenomenological dispersion relation. The non-linear growth has been measured and agrees with calculations. In this lecture, the authors go into the fundamentals of the Rayleigh-Taylor instability and the experimental measurements that show it is stabilized sufficiently by ablation in regimes relevant to ICF.
Date: August 4, 1994
Creator: Kilkenny, J. D.
System: The UNT Digital Library
Experimental level-structure determination in odd-odd actinide nuclei (open access)

Experimental level-structure determination in odd-odd actinide nuclei

The status of experimental determination of level structure in odd-odd actinide nuclei is reviewed. A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei is applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation are derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings are used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Applications of this modeling technique are discussed.
Date: April 4, 1985
Creator: Hoff, R.W.
System: The UNT Digital Library
Sns Accumulator Ring Design and Space Charge Considerations (open access)

Sns Accumulator Ring Design and Space Charge Considerations

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5{micro}s with average beam power of 1MW. To achieve such purpose, a proton storage ring operated at 60Hz with 1 x 10{sup 14} protons per pulse at 1GeV is required. The Accumulator Ring (AR) receives 1msec long H{sup {minus}} beam bunches of 28mA from a 1GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generation and beam collimation etc. is discussed.
Date: May 4, 1998
Creator: Weng, W. T.
System: The UNT Digital Library
Laser driven instabilities in inertial confinement fusion (open access)

Laser driven instabilities in inertial confinement fusion

Parametric instabilities excited by an intense electromagnetic wave in a plasma is a fundamental topic relevant to many applications. These applications include laser fusion, heating of magnetically-confined plasmas, ionospheric modification, and even particle acceleration for high energy physics. In laser fusion, these instabilities have proven to play an essential role in the choice of laser wavelength. Characterization and control of the instabilities is an ongoing priority in laser plasma experiments. Recent progress and some important trends will be discussed. 8 figs.
Date: June 4, 1990
Creator: Kruer, W.L.
System: The UNT Digital Library
Novel QCD Phenomena and New Perspectives for Hadron Physics (open access)

Novel QCD Phenomena and New Perspectives for Hadron Physics

None
Date: February 4, 2014
Creator: Brodsky, Stanley J.
System: The UNT Digital Library
Measurement of Branching Fractions and Charge Asymmetries in B(plus or minus) --->(density)(plus or minus)(pi)0 and B(plus or minus) ---> (density)0(pi)(plus or minus) Decays, and Search for B0 ---> (density)0(pi)o (open access)

Measurement of Branching Fractions and Charge Asymmetries in B(plus or minus) --->(density)(plus or minus)(pi)0 and B(plus or minus) ---> (density)0(pi)(plus or minus) Decays, and Search for B0 ---> (density)0(pi)o

None
Date: November 4, 2003
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.; Hicheur, A.; Karyotakis, Y. et al.
System: The UNT Digital Library
First polarized proton collision at a beam energy of 250 GeV in RHIC (open access)

First polarized proton collision at a beam energy of 250 GeV in RHIC

After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.
Date: May 4, 2009
Creator: Bai,M.; Ahrens, L.; Alekseev, I. G.; Alessi, J. & al., et
System: The UNT Digital Library
The Impact of Theoretical Uncertainties in the Halo Mass Function and Halo (open access)

The Impact of Theoretical Uncertainties in the Halo Mass Function and Halo

We study the impact of theoretical uncertainty in the dark matter halo mass function and halo bias on dark energy constraints from imminent galaxy cluster surveys. We find that for an optical cluster survey like the Dark Energy Survey, the accuracy required on the predicted halo mass function to make it an insignificant source of error on dark energy parameters is {approx}1%. The analogous requirement on the predicted halo bias is less stringent ({approx}5%), particularly if the observable-mass distribution can be well constrained by other means. These requirements depend upon survey area but are relatively insensitive to survey depth. The most stringent requirements are likely to come from a survey over a significant fraction of the sky that aims to observe clusters down to relatively low mass, M{sub th}{approx} 10{sup 13.7} h{sup -1} M{sub sun}; for such a survey, the mass function and halo bias must be predicted to accuracies of {approx}0.5% and {approx}1%, respectively. These accuracies represent a limit on the practical need to calibrate ever more accurate halo mass and bias functions. We find that improving predictions for the mass function in the low-redshift and low-mass regimes is the most effective way to improve dark energy constraints.
Date: June 4, 2010
Creator: Wu, Hao-Yi; Zentner, Andrew R. & Wechsler, Risa H.
System: The UNT Digital Library
Using Perspective to Model Complex Processes (open access)

Using Perspective to Model Complex Processes

The notion of perspective, when supported in an object-based knowledge representation, can facilitate better abstractions of reality for modeling and simulation. The object modeling of complex physical and chemical processes is made more difficult in part due to the poor abstractions of state and phase changes available in these models. The notion of perspective can be used to create different views to represent the different states of matter in a process. These techniques can lead to a more understandable model. Additionally, the ability to record the progress of a process from start to finish is problematic. It is desirable to have a historic record of the entire process, not just the end result of the process. A historic record should facilitate backtracking and re-start of a process at different points in time. The same representation structures and techniques can be used to create a sequence of process markers to represent a historic record. By using perspective, the sequence of markers can have multiple and varying views tailored for a particular user's context of interest.
Date: April 4, 1999
Creator: Kelsey, R.L. & Bisset, K.R.
System: The UNT Digital Library
APDS: The Autonomous Pathogen Detection System (open access)

APDS: The Autonomous Pathogen Detection System

We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system was developed to provide early warning to civilians in the event of a bioterrorism incident and can be used at high profile events for short-term, intensive monitoring or in major public buildings or transportation nodes for long-term monitoring. The APDS is completely automated, offering continuous aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and nucleic-acid based polymerase chain reaction (PCR) amplification and detection. Highly multiplexed antibody-based and duplex nucleic acid-based assays are combined to reduce false positives to a very low level, lower reagent costs, and significantly expand the detection capabilities of this biosensor. This article provides an overview of the current design and operation of the APDS. Certain sub-components of the ADPS are described in detail, including the aerosol collector, the automated sample preparation module that performs multiplexed immunoassays with confirmatory PCR, and the data monitoring and communications system. Data obtained from an APDS that operated continuously for seven days in a major U.S. transportation hub is reported.
Date: October 4, 2004
Creator: Hindson, Benjamin; Makarewicz, Anthony; Setlur, Ujwal; Henderer, Bruce; McBride, Mary & Dzenitis, John
System: The UNT Digital Library
Sensor and actuator considerations for precision, small machines: a review (open access)

Sensor and actuator considerations for precision, small machines: a review

This article reviews some design considerations for the scaling down in size of instruments and machines with a primary aim to identify technologies that may provide more optimal performance solutions than those, often established, technologies used at macroscopic, or conventional, scales. Dimensional metrology within emerging applications will be considered for meso- through micro-down to nanometer level systems with particular emphasis on systems for which precision is directly related to function. In this paper, attention is limited to some of the more fundamental issues associated with scaling. For example, actuator work or power densities or the effect of noise on the sensor signals can be readily evaluated and provide some guidance in the selection for any given size of device. However, with reductions in scale these parameters and/or phenomena that limit performance may change. Within this review, the authors have tried to assess these complex inter-relationships between performance and scale, again from a fundamental perspective. In practice, it is likely that the nuances of implementation and integration of sensor, actuator and/or mechanism designs will determine functionality and commercial viability of any particular system development.
Date: April 4, 2005
Creator: Smith, S. T. & Seugling, R. M.
System: The UNT Digital Library
The impact of high-immersion virtual reality on foreign language anxiety (open access)

The impact of high-immersion virtual reality on foreign language anxiety

Authors of the article assert that public speaking, especially in a foreign language, is associated with increased anxiety. The authors found that VR technology had a positive effect on practicing public speaking in a foreign language, the research findings have practical implications for professionals and curriculum designers in various domains where public speaking skills are essential.
Date: October 4, 2023
Creator: Kaplan-Rakowski, Regina & Gruber, Alice
System: The UNT Digital Library
Simulations on the AGS horizontal tune jump mechanism (open access)

Simulations on the AGS horizontal tune jump mechanism

A new horizontal tune jump mechanism has been proposed to overcome the horizontal intrinsic resonances and preserve the polarization of the proton beam in the Alternating Gradient Synchrotron (AGS) during the energy ramp. An adiabatic change of the AGS lattice is needed to avoid the emittance growth in both horizontal and vertical planes, as the emittance growth can deteriorate the polarization of the proton beam. Two critical questions are necessary to be answered: how fast can the lattice be changed and how much emittance growth can be tolerated from both optics and polarization points of view? Preliminary simulations, using a realistic AGS lattice and acceleration rate, have been carried out to give a first glance of this mechanism. Results with different optics are presented in this paper.
Date: May 4, 2009
Creator: Lin,F.; Huang, H.; Luccio, A. U. & Roser, T.
System: The UNT Digital Library
The urban perspectives of acid rain. Workshop summary (open access)

The urban perspectives of acid rain. Workshop summary

This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility.
Date: June 4, 1993
Creator: Tonn, B. E.
System: The UNT Digital Library
Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2010 (open access)

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2010

Article on phase transition enthalpy measurements of organic and organometallic compounds, sublimation, and vaporization and fusion enthalpies from 1880 to 2010.
Date: October 4, 2010
Creator: Acree, William E. (William Eugene) & Chickos, James S.
System: The UNT Digital Library
Conference on legal aspects of geothermal development (open access)

Conference on legal aspects of geothermal development

Fifteen papers and abstracts are included. Separate abstracts were prepared for six papers and nine abstracts were listed by title.
Date: December 4, 1981
Creator: unknown
System: The UNT Digital Library