CaO interaction in the staged combustion of coal (open access)

CaO interaction in the staged combustion of coal

The LIMB (limestone injection multi-stage burner) process offers special potential for reducing NO/sub x/ and SO/sub x/ by at least 50 percent in coal combustion. This is to be accomplished by adding limestone with fuel and/or air in a low NO/sub x/ burner. This program has been directed to defining the chemistry and kinetics necessary to optimize sulfur capture in LIMB combustion. More specifically, this program has attempted to clarify the role of calcium sulfide in LIMB chemistry. When limestone is added in a staged burner, there is a strong possibility that under certain circumstances CaS is produced in the reducing (fuel-rich) zone of the burner. Since CaS is more stable than CaSO/sub 4/, this affords the opportunity to (1) operate the burner at a higher temperature, 2200 to 2500 F, (2) pass the CaS rapidly through the high temperature zone (before dissociation), and (3) complete the combustion in a lean (air-rich) region where the sulfur is finally retained in CaSO/sub 4/. For these reasons this program has concentrated on the high temperature chemistry and kinetics of CaS. To achieve the program objective, the program was divided into three tasks. These involved (1) a study of CaS formation, (2) a …
Date: December 19, 1983
Creator: Levy, Arthur; Merryman, Earl L. & Rising, Bruce W.
Object Type: Report
System: The UNT Digital Library
New York Nano-Bio Molecular Information Technology (NYNBIT) Incubator (open access)

New York Nano-Bio Molecular Information Technology (NYNBIT) Incubator

This project presents the outcome of an effort made by a consortium of six universities in the State of New York to develop a Center for Advanced technology (CAT) in the emerging field of Nano-Bio-Molecular Information Technology. The effort consists of activities such as organization of the NYNBIT incubator, collaborative research projects, development of courses, an educational program for high schools, and commercial start-up programs.
Date: December 19, 2008
Creator: Das, Digendra K
Object Type: Report
System: The UNT Digital Library
MEMS adaptive optics for the Gemini Planet Imager: control methods and validation (open access)

MEMS adaptive optics for the Gemini Planet Imager: control methods and validation

None
Date: December 19, 2007
Creator: Poyneer, L A & Dillon, D
Object Type: Article
System: The UNT Digital Library
Electron Beam Lifetime in SPEAR3: Measurement and Simulation (open access)

Electron Beam Lifetime in SPEAR3: Measurement and Simulation

In this paper we report on electron beam lifetime measurements as a function of scraper position, RF voltage and bunch fill pattern in SPEAR3. We then outline development of an empirical, macroscopic model using the beam-loss rate equation. By identifying the dependence of loss coefficients on accelerator and beam parameters, a numerically-integrating simulator can be constructed to compute beam decay with time. In a companion paper, the simulator is used to train a parametric, non-linear dynamics model for the system [1].
Date: December 19, 2007
Creator: Corbett, J.; Huang, X.; Lee, M. & Lui, P.
Object Type: Article
System: The UNT Digital Library
Sum Frequency Generation Vibrational Spectroscopy Studies on ModelPeptide Adsorption at the Hydrophobic Solid-Water and HydrophilicSolid-Water Interfaces (open access)

Sum Frequency Generation Vibrational Spectroscopy Studies on ModelPeptide Adsorption at the Hydrophobic Solid-Water and HydrophilicSolid-Water Interfaces

Sum frequency generation (SFG) vibrational spectroscopy has been used to study the interfacial structure of several polypeptides and amino acids adsorbed to hydrophobic and hydrophilic surfaces under a variety of experimental conditions. Peptide sequence, peptide chain length, peptide hydrophobicity, peptide side-chain type, surface hydrophobicity, and solution ionic strength all affect an adsorbed peptide's interfacial structure. Herein, it is demonstrated that with the choice of simple, model peptides and amino acids, surface specific SFG vibrational spectroscopy can be a powerful tool to elucidate the interfacial structure of these adsorbates. Herein, four experiments are described. In one, a series of isosequential amphiphilic peptides are synthesized and studied when adsorbed to both hydrophobic and hydrophilic surfaces. On hydrophobic surfaces of deuterated polystyrene, it was determined that the hydrophobic part of the peptide is ordered at the solid-liquid interface, while the hydrophilic part of the peptide appears to have a random orientation at this interface. On a hydrophilic surface of silica, it was determined that an ordered peptide was only observed if a peptide had stable secondary structure in solution. In another experiment, the interfacial structure of a model amphiphilic peptide was studied as a function of the ionic strength of the solution, a …
Date: December 19, 2007
Creator: York, Roger L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Development of a Water Environment Fatigue Design Curve for Austenitic Stainless Steels (open access)

Development of a Water Environment Fatigue Design Curve for Austenitic Stainless Steels

This note presents the technical basis for a proposed strain-rate and temperature independent fatigue design curve for austenitic stainless steels.
Date: December 19, 2002
Creator: Leax, T. R.
Object Type: Report
System: The UNT Digital Library
New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography (open access)

New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography

This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target technology by a factor of two to four, significantly limiting the production rate of Fluorine-18.
Date: December 19, 2008
Creator: Doster, J. Michael
Object Type: Report
System: The UNT Digital Library
Hard QCD Processes at Colliders (open access)

Hard QCD Processes at Colliders

Recent developments in the study of hard QCD processes at colliders are reviewed, in the context of the imminent startup of the LHC.
Date: December 19, 2007
Creator: Dixon, Lance J.
Object Type: Article
System: The UNT Digital Library
Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States (open access)

Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States

The authors present a search for the decays B{sup 0} {yields} e{sup +}e{sup -}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}} using data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Using a dataset corresponding to 384 x 10{sup 6} B{bar B} pairs, they do not find evidence of any of the three decay modes. They obtain upper limit on the branching fractions, at 90% confidence level, of {Beta}(B{sup 0} {yields} e{sup +}e{sup -}) < 11.3 x 10{sup -8}, {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 5.2 x 10{sup -8}, and {Beta}(B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}}) < 9.2 x 10{sup -8}.
Date: December 19, 2007
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
CONSIDERATIONS OF THE ROLE OF THE CATHODIC REGION IN LOCALIZED CORROSION (open access)

CONSIDERATIONS OF THE ROLE OF THE CATHODIC REGION IN LOCALIZED CORROSION

None
Date: December 19, 2005
Creator: KELLY, R.G., LANDAU, U., PAYER, J.H.
Object Type: Article
System: The UNT Digital Library
Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6 (open access)

Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6

The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.
Date: December 19, 2006
Creator: Remsen, W. E.
Object Type: Report
System: The UNT Digital Library
High-Pressure Catalytic Reactions of C6 Hydrocarbons on PlatinumSingle-Crystals and nanoparticles: A Sum Frequency Generation VibrationalSpectroscopic and Kinetic Study (open access)

High-Pressure Catalytic Reactions of C6 Hydrocarbons on PlatinumSingle-Crystals and nanoparticles: A Sum Frequency Generation VibrationalSpectroscopic and Kinetic Study

Catalytic reactions of cyclohexene, benzene, n-hexane, 2-methylpentane, 3-methylpentane, and 1-hexene on platinum catalysts were monitored in situ via sum frequency generation (SFG) vibrational spectroscopy and gas chromatography (GC). SFG is a surface specific vibrational spectroscopic tool capable of monitoring submonolayer coverages under reaction conditions without gas-phase interference. SFG was used to identify the surface intermediates present during catalytic processes on Pt(111) and Pt(100) single-crystals and on cubic and cuboctahedra Pt nanoparticles in the Torr pressure regime and at high temperatures (300K-450K). At low pressures (<10{sup -6} Torr), cyclohexene hydrogenated and dehydrogenates to form cyclohexyl (C{sub 6}H{sub 11}) and {pi}-allyl C{sub 6}H{sub 9}, respectively, on Pt(100). Increasing pressures to 1.5 Torr form cyclohexyl, {pi}-allyl C{sub 6}H{sub 9}, and 1,4-cyclohexadiene, illustrating the necessity to investigate catalytic reactions at high-pressures. Simultaneously, GC was used to acquire turnover rates that were correlated to reactive intermediates observed spectroscopically. Benzene hydrogenation on Pt(111) and Pt(100) illustrated structure sensitivity via both vibrational spectroscopy and kinetics. Both cyclohexane and cyclohexene were produced on Pt(111), while only cyclohexane was formed on Pt(100). Additionally, {pi}-allyl c-C{sub 6}H{sub 9} was found only on Pt(100), indicating that cyclohexene rapidly dehydrogenates on the (100) surface. The structure insensitive production of cyclohexane was found …
Date: December 19, 2007
Creator: Bratlie, Kaitlin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Status of DAFNE (open access)

Status of DAFNE

DA{Phi}NE is a double ring electron-positron collider, designed to provide very high luminosity at the energy of the {Phi} resonance (1.02 GeV c.m.). After storing the first beam in fall 1997, the collider was commissioned without solenoidal detectors until the end of 1998, reaching a single bunch luminosity of 1.6 x 10{sup 30} cm{sup -2}s{sup -1} with 20 mA in each beam, corresponding to a beam-beam tune shift of {approx} 0.03. A longitudinal bunch-to-bunch feedback has been implemented, allowing the storage of more than 0.5 A in 30 bunches for both electrons and positrons. The KLOE detector, embedded into a superconducting solenoid with strong longitudinal field integral (2.4 Tm, to be compared to a magnetic rigidity of 1.7 Tm) compensated by two other solenoids of opposite field, was installed in winter 1999 and commissioning resumed with a careful correction of the coupling effects. Particular effort has been dedicated to the reduction of background in the experiment, which led to the possibility of injecting the beams in interaction without switching off data taking. The total stored current has reached more than 1 A in each beam, while a transverse feedback system has been realized to counteract vertical instabilities occurring during injection. …
Date: December 19, 2007
Creator: Preger, M.; /Frascati; Alesini, D.; Benedetti, G.; Bertolucci, S.; Biscari, C. et al.
Object Type: Article
System: The UNT Digital Library
Formal Specification of the OpenMP Memory Model (open access)

Formal Specification of the OpenMP Memory Model

OpenMP [2] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [2]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provide a formal consistency model that precisely describes how reads and writes on different threads interact. We expand on our previous work that focused on the formal verification of OpenMP programs through a formal memory model [?]. As in that work, our formalization, which is derived from the existing prose model [2], provides a two-step process to verify whether an observed OpenMP execution is conformant. This paper extends the model to cover the entire specification. In addition to this formalization, our contributions include a discussion of ambiguities in the current prose-based memory model description. Although our formal model may not capture the current informal memory model perfectly, in part due to these ambiguities, our model reflects our understanding of the informal model's intent. We conclude with …
Date: December 19, 2006
Creator: Bronevetsky, G & de Supinski, B
Object Type: Article
System: The UNT Digital Library
On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets (open access)

On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets

The first lab-on-chip system for picoliter droplet generation and RNA isolation, followed by reverse transcription, and PCR amplification with real-time fluorescence detection in the trapped droplets has been developed. The system utilized a shearing T-junction in a fused silica device to generate a stream of monodisperse picoliter-scale droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chip, allowing thermal cycling for reverse transcription and subsequent PCR amplification without droplet motion. This combination of the established real-time reverse transcription-PCR assay with digital microfluidics is ideal for isolating single-copy RNA and virions from a complex environment, and will be useful in viral discovery and gene-profiling applications.
Date: December 19, 2007
Creator: Beer, N. R.; Wheeler, E.; Lee-Houghton, L.; Watkins, N.; Nasarabadi, S.; Hebert, N. et al.
Object Type: Article
System: The UNT Digital Library
DIRECT MEASUREMENT OF HEAT FLUX FROM COOLING LAKE THERMAL IMAGERY (open access)

DIRECT MEASUREMENT OF HEAT FLUX FROM COOLING LAKE THERMAL IMAGERY

Laboratory experiments show a linear relationship between the total heat flux from a water surface to air and the standard deviation of the surface temperature field, {sigma}, derived from thermal images of the water surface over a range of heat fluxes from 400 to 1800 Wm{sup -2}. Thermal imagery and surface data were collected at two power plant cooling lakes to determine if the laboratory relationship between heat flux and {sigma} exists in large heated bodies of water. The heat fluxes computed from the cooling lake data range from 200 to 1400 Wm{sup -2}. The linear relationship between {sigma} and Q is evident in the cooling lake data, but it is necessary to apply band pass filtering to the thermal imagery to remove camera artifacts and non-convective thermal gradients. The correlation between {sigma} and Q is improved if a correction to the measured {sigma} is made that accounts for wind speed effects on the thermal convection. Based on more than a thousand cooling lake images, the correlation coefficients between {sigma} and Q ranged from about 0.8 to 0.9.
Date: December 19, 2007
Creator: Garrett, A; Eliel Villa-Aleman, E; Robert Kurzeja, R; Malcolm Pendergast, M; Timothy Brown, T & Saleem Salaymeh, S
Object Type: Article
System: The UNT Digital Library
Chapter 9: Electronics (open access)

Chapter 9: Electronics

Sophisticated front-end electronics are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, electronic noise, pulse shaping (analog and digital), and data readout techniques.
Date: December 19, 2006
Creator: Grupen, Claus & Shwartz, Boris A.
Object Type: Book
System: The UNT Digital Library
General Features of Supersymmetric Signals at the ILC: Solving the LHC Inverse Problem (open access)

General Features of Supersymmetric Signals at the ILC: Solving the LHC Inverse Problem

We examine whether the {radical}s = 500 GeV International Linear Collider with 80% electron beam polarization can be used to solve the LHC Inverse Problem within the framework of the MSSM. We investigate 242 points in the MSSM parameter space, which we term models, that correspond to the 162 pairs of models found by Arkani-Hamed et al. to give indistinguishable signatures at the LHC. We first determine whether the production of the various SUSY particles is visible above the Standard Model background for each of these parameter space points, and then make a detailed comparison of their various signatures. Assuming an integrated luminosity of 500 fb{sup -1}, we find that only 82 out of 242 models lead to visible signatures of some kind with a significance {ge} 5 and that only 57(63) out of the 162 model pairs are distinguishable at 5(3){sigma}. Our analysis includes PYTHIA and CompHEP SUSY signal generation, full matrix element SM backgrounds for all 2 {yields} 2, 2 {yields} 4, and 2 {yields} 6 processes, ISR and beamstrahlung generated via WHIZARD/GuineaPig, and employs the fast SiD detector simulation org.lcsim.
Date: December 19, 2007
Creator: Berger, Carola F.; Gainer, James S.; Hewett, JoAnne L.; Lillie, Ben & Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Physics of Extra Dimensions Final Report (open access)

Physics of Extra Dimensions Final Report

We provide the final report for Csaba Csaki's OJI project on "Physics of extra dimensions". It includes the summary of results of higgsless electroweak symmetry breaking, gauge-higgs unification, AdS/QCD and holographic technicolor, and chiral lattice theories from warped extra dimensions.
Date: December 19, 2007
Creator: Csaki, Csaba
Object Type: Report
System: The UNT Digital Library
Electron cyclotron resonance heating of tandem mirrors (open access)

Electron cyclotron resonance heating of tandem mirrors

Heating electrons by microwave power near either the electron cyclotron frequency or its harmonic is analyzed in some detail. The purpose of this study is to determine whether electrons in current or future mirror devices could be heated by electromagnetic waves in this frequency range. Absorption lengths, accessibility conditions, and appropriate polarization are among the concerns studied. It is found that the Tandem Mirror Experiment (TMX) may efficiently be heated by the extraordinary mode at omega = omega either in the solenoid-to-plug transition region or near the center of the plug at densities napprox. = 10/sup 13/cm/sup -3/.
Date: December 19, 1978
Creator: Porkolab, M.
Object Type: Report
System: The UNT Digital Library
Experimental investigation of the production of glueballs and meson resonance states (open access)

Experimental investigation of the production of glueballs and meson resonance states

We have made striking and considerable progress in our AGS program which is searching for a Quark-Gluon Plasma or other new phenomena at the AGS. We are employing a TCP Tracking Magnetic Spectrometer that has handled up to {approx}100 tracks, the maximum observed in 14.5 GeV/c {times} A Si ions incident on Au and Cu. In essence the TPC covers more than the forward half hemisphere in the nucleon-nucleon cms (i.e. {ge} 2{pi}) and thus allows tracking, momentum and angular analysis of the charged particles emitted in these heavy ion collisions. Particle identification for negative pions can be made approximately by assuming negative particles are pions. Then by subtraction of negatives from positives in a suitable manner the proton characteristics can be determined. {Lambda} and K{sub s}{sup 0} V particles have been identified singly in events and {approx}50 double {Lambda} and 2 triple {Lambda} events have been observed in the relatively small data sample we have obtained and analyzed this year. Further discussion of these topics are contained in this report.
Date: December 19, 1990
Creator: Lindenbaum, S. J.
Object Type: Report
System: The UNT Digital Library
Research in particle physics beyond the standard model (open access)

Research in particle physics beyond the standard model

This report discusses research done in string field theory; bosonic technicolor; and supersymmetry. (LSP)
Date: December 19, 1990
Creator: Samuel, S.
Object Type: Report
System: The UNT Digital Library
Is there a hard gluonic contribution to the first moment of g sub 1 (open access)

Is there a hard gluonic contribution to the first moment of g sub 1

We show that the size of the hard gluonic contribution to the first moment of the proton's spin-dependent structure function g{sub 1} is entirely a matter of the convention used in defining the quark distributions. If the UV regulator for the spin-dependent quark distributions respects the gauge invariance of Green's functions (allows shifts of loop momenta) and respects the analyticity structure of the unregulated distributions, then the hard gluonic contribution to the first moment of g{sub 1} vanishes. This is the case, for example, in dimensional regularization. By relaxing the requirement that the regulator allow shifts of loop moments, we are able to obtain a nonvanishing hard gluonic contribution to the first moment of g{sub 1}. However, the first moments of the resulting quark distributions correspond to matrix elements that are either gauge variant or involve nonlocal operators and, hence, have no analogue in the standard operator-product expansion. 11 refs., 2 figs.
Date: December 19, 1990
Creator: Bodwin, G.T. (Argonne National Lab., IL (USA)) & Qiu, Jianwei (State Univ. of New York, Stony Brook, NY (USA). Inst. for Theoretical Physics)
Object Type: Article
System: The UNT Digital Library
Attitude control of a spinning rocket via thrust vectoring (open access)

Attitude control of a spinning rocket via thrust vectoring

Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is tested for the ability to track step commands, and for the amount of coupling impurity. Both controllers are developed via a linear-quadratic-regulator synthesis procedure, which is motivated by the multi-input/multi-output nature of second controller. Time responses and a singular value analysis are used to evaluate controller performance. This paper describes the development and comparison of two controllers that are designed to provide attitude control of a spinning rocket that is equipped with thrust vector control. 12 refs., 13 figs., 2 tabs.
Date: December 19, 1990
Creator: White, J.E.
Object Type: Article
System: The UNT Digital Library