Pattern of Thermal Fluctuations in a Recovery Boiler Floor (open access)

Pattern of Thermal Fluctuations in a Recovery Boiler Floor

The floor of a black liquor recovey boiler at a mill in central Canada has experienced cracking and delamination of the composite tubing near the spout wall and deformation of the floor panels that is most severe in the vicinity of the spout wall. One possible explanation for the observed damage is impacts of salt cake falling from the convective section onto the floor. In order to determine if such impacts do occur, strain gauges and thermocouples were installed on the boiler floor in areas where cracking and deformation were most frequent. The data obtained from these instruments indicate that brief, sudden temperature fluctuations do occur, and changes in the strain experienced by the affected tube occur simultaneously. These fluctuations appear to occur less often along the spout wall and more frequently with increasing distance from the wall. The frequency of these temperature fluctuations is insufficient for thermal fatigue to be the sole cause of the cracking observed on the tubes, but the data are consistent with what might be expected from pieces of falling salt cake.
Date: April 25, 1999
Creator: Abdullah, Z.; Gorog, J. P.; Keiser, J. R.; Meyers, L. E. & Swindeman, R. W.
Object Type: Article
System: The UNT Digital Library
Damage Accumulation in MgAl{sub 2}O{sub 4} and Yttria-Stabilized ZrO{sub 2} by Xe-Ion Irradiation (open access)

Damage Accumulation in MgAl{sub 2}O{sub 4} and Yttria-Stabilized ZrO{sub 2} by Xe-Ion Irradiation

Magnesium-aluminate spinel (MAS) and yttria-stabilized zirconia (YSZ) are being considered for use as ceramic matrices in proliferation resistant fuels and radioactive storage systems, and may be used either as individual entities or as constituents in multicomponent ceramic systems. It is worthwhile, therefore, to compare radiation damage in these two potentially important materials when subjected to similar irradiation conditions, e.g., ion beam irradiation. To compare radiation damage properties of these two materials, single crystals of spinel and zirconia were irradiated with 340 keV Xe{sup ++} ions at 120 K, and subsequently investigated by Rutherford backscattering and ion channeling (RBS/C), and optical absorption spectroscopy. Results indicate that damage accumulation in both spinel and zirconia follow a three stage process: (1) very slow damage accumulation over a wide range of dose; (2) rapid changes in damage over a range of doses from about 0.25 to 25 displacements per atom (DPA); (3) slower damage accumulation at very high doses and possibly saturation. Optical absorption results indicate that F-centers form in Xe ion-irradiated spinel and that the concentration of these centers saturates at high dose. Absorption bands are also formed in both spinel and zirconia that are due to point defect complexes formed upon irradiation. …
Date: April 25, 1999
Creator: Afanasyev-Charkin, I.V.; Gritsyna, V.T.; Cooke, D.W.; Bennett, B.L. & Sickafus, K.E.
Object Type: Article
System: The UNT Digital Library
Can Cavitation Be Anticipated? (open access)

Can Cavitation Be Anticipated?

The major problem with cavitation in pumps and hydraulic systems is that there is no effective (conventional) method for detecting or predicting its inception. The traditional method of recognizing cavitation in a pump is to declare the event occurring when the total head drops by some arbitrary value (typically 3%) in response to a pressure reduction at the pump inlet. However, the device is already seriously cavitating when this happens. What is actually needed is a practical method to detect impending rather than incipient cavitation. Whereas the detection of incipient cavitation requires the detection of features just after cavitation starts, the anticipation of cavitation requires the detection and identification of precursor features just before it begins. Two recent advances that make this detection possible. The first is acoustic sensors with a bandwidth of 1 MHz and a dynamic range of 80 dB that preserve the fine details of the features when subjected to coarse vibrations. The second is the application of Bayesian parameter estimation which makes it possible to separate weak signals, such as those present in cavitation precursors, from strong signals, such as pump vibration. Bayesian parameter estimation derives a model based on cavitation hydrodynamics and produces a figure …
Date: April 25, 1999
Creator: Allgood, G. O.; Dress, W. B.; Hylton, J. O. & Kercel, S. W.
Object Type: Article
System: The UNT Digital Library
Improvement in Devices for Teaching Musical Transposition. (open access)

Improvement in Devices for Teaching Musical Transposition.

Patent for an improvement in devices for teaching musical transposition. The invention in question is composed of a keyboard "with sliding instruments and scales" (1).
Date: April 25, 1876
Creator: Allison, Thomas J.
Object Type: Patent
System: The Portal to Texas History
DISTRIBUTION COEFICIENTS (KD) GENERATED FROM A CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY (open access)

DISTRIBUTION COEFICIENTS (KD) GENERATED FROM A CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY

Core samples originating from Vault 4, Cell E of the Saltstone Disposal Facility (SDF) were collected in September of 2008 (Hansen and Crawford 2009, Smith 2008) and sent to SRNL to measure chemical and physical properties of the material including visual uniformity, mineralogy, microstructure, density, porosity, distribution coefficients (K{sub d}), and chemical composition. Some data from these experiments have been reported (Cozzi and Duncan 2010). In this study, leaching experiments were conducted with a single core sample under conditions that are representative of saltstone performance. In separate experiments, reducing and oxidizing environments were targeted to obtain solubility and Kd values from the measurable species identified in the solid and aqueous leachate. This study was designed to provide insight into how readily species immobilized in saltstone will leach from the saltstone under oxidizing conditions simulating the edge of a saltstone monolith and under reducing conditions, targeting conditions within the saltstone monolith. Core samples were taken from saltstone poured in December of 2007 giving a cure time of nine months in the cell and a total of thirty months before leaching experiments began in June 2010. The saltstone from Vault 4, Cell E is comprised of blast furnace slag, class F fly …
Date: April 25, 2011
Creator: Almond, P. & Kaplan, D.
Object Type: Report
System: The UNT Digital Library
The [Sigma/Alpha] Branching Ratio Of [Y*1] (open access)

The [Sigma/Alpha] Branching Ratio Of [Y*1]

Recently a T=1 resonance in the [Alpha w] system called [Y*1] has been observed with a mass of 1385 Mev. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the Alpha w and Sigma w systems predicted by global symmetry corresponding to the (3/2, 3/2) resonance of the wN system, (2) a spin-1/2 Y-w resonance resulting from a bound state in the KN system. The position and width of the observed [Y*1] resonance agree with both theories but since the spin and parity have not yet been determined, it is impossible at present to distinguish between the two theoretical interpretations.
Date: April 25, 1961
Creator: Alston, Margaret H.; Alvarez, Luis W., 1911-1988; Eberhard, Phillippe; Good, Myron L.; Graziano, William; Ticho, Harold K., 1921-2020 et al.
Object Type: Report
System: The UNT Digital Library
THE Epsilon*/Lambda BRANCHING RATIO OF Y*1 (open access)

THE Epsilon*/Lambda BRANCHING RATIO OF Y*1

Recently a T = 1 resonance in the {Lambda}{pi} system called Y*{sub 1} has been observed with a mass of 1385 Mev. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the {Lambda}{pi} and {Sigma}{pi} systems predicted by global symmetry corresponding to the (3/2, 3/2) resonance of the {pi}N system; (2) a spin-1/2 Y-{pi} resonance resulting from a bound state in the KN system. The position and width of the observed Y*{sub 1} resonance agree with both theories, but since the spin and parity have not yet been determined, it is impossible at present to distinguish between the two theoretical interpretations.
Date: April 25, 1961
Creator: Alston, Margaret H.; Alvarez, Luis W.; Eberhard, Philippe; Good,Myron L.; Graziano, William; Ticho, Harold K. et al.
Object Type: Article
System: The UNT Digital Library

Testing the Concept of Drift Shadow With X-Ray Absorption Imaging Experiments

None
Date: April 25, 2006
Creator: Altman, S.J.
Object Type: Presentation
System: The UNT Digital Library
House and Senate Chaplains (open access)

House and Senate Chaplains

None
Date: April 25, 2008
Creator: Amer, Mildred
Object Type: Report
System: The UNT Digital Library
The Strategic Petroleum Reserve: Authorization, Operation, and Drawdown Policy (open access)

The Strategic Petroleum Reserve: Authorization, Operation, and Drawdown Policy

This report looks at the history, purpose, and current status of the Strategic Petroleum Reserve.
Date: April 25, 2012
Creator: Andrews, Anthony & Pirog, Robert
Object Type: Report
System: The UNT Digital Library
Neutron Remote Area Monitoring Systems (open access)

Neutron Remote Area Monitoring Systems

The following report records measurements and evaluations of fast neutron levels in remote areas monitored by personnel.
Date: April 25, 1958
Creator: Appleby, Charles W.
Object Type: Report
System: The UNT Digital Library
Automated DNA Sequencing System (open access)

Automated DNA Sequencing System

Oak Ridge National Laboratory (ORNL) is developing a core DNA sequencing facility to support biological research endeavors at ORNL and to conduct basic sequencing automation research. This facility is novel because its development is based on existing standard biology laboratory equipment; thus, the development process is of interest to the many small laboratories trying to use automation to control costs and increase throughput. Before automation, biology Laboratory personnel purified DNA, completed cycle sequencing, and prepared 96-well sample plates with commercially available hardware designed specifically for each step in the process. Following purification and thermal cycling, an automated sequencing machine was used for the sequencing. A technician handled all movement of the 96-well sample plates between machines. To automate the process, ORNL is adding a CRS Robotics A- 465 arm, ABI 377 sequencing machine, automated centrifuge, automated refrigerator, and possibly an automated SpeedVac. The entire system will be integrated with one central controller that will direct each machine and the robot. The goal of this system is to completely automate the sequencing procedure from bacterial cell samples through ready-to-be-sequenced DNA and ultimately to completed sequence. The system will be flexible and will accommodate different chemistries than existing automated sequencing lines. The …
Date: April 25, 1999
Creator: Armstrong, G. A.; Ekkebus, C. P.; Hauser, L. J.; Kress, R. L. & Mural, R. J.
Object Type: Article
System: The UNT Digital Library
Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys (open access)

Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys

This health and safety guide was written to satisfy two objectives: to summarize the toxicity of metals and alloys used in superconductivity for the benefit of those who work with these materials, and to summarize and describes the basic principles of a highly technical field from a health and safety point-of-view for the benefit of health professionals. The guide begins with a profile of the superconductivity industry, including a list of current and potential applications, a literature review of the market potential, and summary of the current industry status. The body of the paper provides a toxicity and hazard summary for 50 metals, alloys and metal oxides used in superconductivity. The toxicity and hazard summary for all 50 compounds includes: occupational exposure limits, explosiveness and flammability potential, LD{sub 50}'s, chemical and physical properties, incompatibilities and reactivities, recommended personal protective equipment, symptoms of acute and chronic exposure, target organs and toxic effects, and steps for emergency first aid. Finally, a discussion of general occupational hygiene principles is provided, with emphasis on how these principles apply to the unique field of superconductivity. 41 refs.
Date: April 25, 1990
Creator: Arnold, S. D. & Talley, G. M.
Object Type: Article
System: The UNT Digital Library
Plow Cultivator and Irrigator. (open access)

Plow Cultivator and Irrigator.

Patent for an underground irrigating plow that consists of a draft bar, crank arms, plow beams that front ends swivel on the crank arms, a ratchet rod with chain spools, a ratchet lever that is attached to the ratchet rod, chains that are attached to the plow beams and the spools, braces that are attached to the crank arms, and a double-tree.
Date: April 25, 1893
Creator: Askew, Joseph W.
Object Type: Patent
System: The Portal to Texas History
Toward automating the database design process (open access)

Toward automating the database design process

One organization's approach to designing complex, interrelated databases is described. The problems encountered and the techniques developed are discussed. A set of software tools to aid the designer and to produce an initial database design directly is presented. 5 figures.
Date: April 25, 1979
Creator: Asprey, P.L.
Object Type: Article
System: The UNT Digital Library
Improved Measurement of CP Violation in Neutral BDecays to \ccbar s (open access)

Improved Measurement of CP Violation in Neutral BDecays to \ccbar s

The authors present updated measurements of time-dependent CP asymmetries in fully-reconstructed neutral B decays to several CP eigenstates containing a charmonium meson. The measurements use a data sample of (383 {+-} 4) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II B factory. They determine sin2{beta} = 0.714 {+-} 0.032(stat) {+-} 0.018(syst) and |{lambda}| = 0.952 {+-} 0.022(stat) {+-} 0.017(syst).
Date: April 25, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of Decay Amplitudes of B to (ccbar) K^* withan Angular Analysis, for (ccbar)=J/Psi,Psi(2S) and Chi_c1 (open access)

Measurement of Decay Amplitudes of B to (ccbar) K^* withan Angular Analysis, for (ccbar)=J/Psi,Psi(2S) and Chi_c1

The authors perform the first three-dimensional measurement of the amplitudes of B {yields} {psi}(2S)K* and B {yields} {chi}{sub c1}K* decays and update the previous measurement B {yields} J/{psi}K*. They use a data sample collected with the BABAR detector at the PEP-II storage ring, corresponding to 232 million B{bar B} pairs. The longitudinal polarization of decays involving a J{sup PC} = 1{sup ++} {chi}{sub c1} meson is found to be larger than that with a 1{sup --} J/{psi} or {psi}(2S) meson. No direct CP-violating charge asymmetry is observed.
Date: April 25, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Absolute Branching Fraction of D0 to K- pi+ (open access)

Measurement of the Absolute Branching Fraction of D0 to K- pi+

The authors measure the absolute branching fraction for D{sup 0} {yields} K{sup -} {pi}{sup +} using partial reconstruction of {bar B}{sup 0} {yields} D*{sup +}X{ell}{sup -}{bar {nu}}{sub {ell}} decays, in which only the charged lepton and the pion from the decay D*{sup +} {yields} D{sup 0}{pi}{sup +} are used. Based on a data sample of 230 million B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain {Beta}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (4.007 {+-} 0.037 {+-} 0.070)%, where the first error is statistical and the second error is systematic.
Date: April 25, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Discretionary Budget Authority by Subfunction: An Overview (open access)

Discretionary Budget Authority by Subfunction: An Overview

This report presents figures showing trends in discretionary budget authority as a percentage of GDP by subfunction within each of 17 budget function categories, using data from President Obama's FY2014 budget submission. The report also provides a graphical overview of historical trends in discretionary budget authority from FY1976 through FY2012, preliminary estimates for FY2013 spending, and the levels consistent with the President's proposals for FY2014 through FY2018.
Date: April 25, 2013
Creator: Austin, D. Andrew
Object Type: Report
System: The UNT Digital Library
Flooding and mass transfer in Goodloe-packed columns, Part 2. [HTGR] (open access)

Flooding and mass transfer in Goodloe-packed columns, Part 2. [HTGR]

Krypton gas is recovered from HTGR off-gas streams by countercurrent absorption in liquid carbon dioxide. Goodloe stainless steel wire mesh packing was chosen for the absorption columns since the process operates at -20/sup 0/C and about 20 atm pressure. Flooding points and an overall mass transfer coefficient for Goodloe-packed columns were determined with a carbon dioxide-air-water system for 6.4 and 15.2-cm-ID columns. Flood points were obtained for liquid-to-gas mass velocity ratios of 20 to 800. A mixing model, assuming plug flow for the gas and dispersed flow for the liquid, was used to calculate an overall mass transfer coefficient, K/sub L/a. K/sub L/a, based on mass concentrations, ranged from 0.01 to 0.08 sec/sup -T/ and was found to increase with increasing liquid flow rate.
Date: April 25, 1977
Creator: Ayala, J. S.; Brian, B. W. & Sharon, A. C.
Object Type: Report
System: The UNT Digital Library
Fabrication and In Vitro Deployment of a Laser-Activated Shape Memory Polymer Vascular Stent (open access)

Fabrication and In Vitro Deployment of a Laser-Activated Shape Memory Polymer Vascular Stent

Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP) stent may enhance flexibility, compliance, and drug elution compared to its current metallic counterparts. The purpose of this study was to describe the fabrication of a laser-activated SMP stent and demonstrate photothermal expansion of the stent in an in vitro artery model. A novel SMP stent was fabricated from thermoplastic polyurethane. A solid SMP tube formed by dip coating a stainless steel pin was laser-etched to create the mesh pattern of the finished stent. The stent was crimped over a fiber-optic cylindrical light diffuser coupled to an infrared diode laser. Photothermal actuation of the stent was performed in a water-filled mock artery. At a physiological flow rate, the stent did not fully expand at the maximum laser power (8.6 W) due to convective cooling. However, under zero flow, simulating the technique of endovascular flow occlusion, complete laser actuation was achieved in the mock artery at a laser power of {approx}8 W. We have shown the design and fabrication of an SMP stent and …
Date: April 25, 2007
Creator: Baer, G. M.; Small, W., IV; Wilson, T. S.; Benett, W. J.; Matthews, D. L.; Hartman, J. et al.
Object Type: Article
System: The UNT Digital Library
Newsletter of Texas State Representative Ernest Bailes: Volume 1, Issue 7, April 2017 (open access)

Newsletter of Texas State Representative Ernest Bailes: Volume 1, Issue 7, April 2017

Newsletter of Ernest Bailes for his constituents in district 18 discussing news, activities, and various updates related to work in the Texas legislature. It focuses on tax reform, a proposed bill concerning volunteer firefighters, public education transportation funding, the Blue Alert System, and handgun issues.
Date: April 25, 2017
Creator: Bailes, Ernest James, IV
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Dual Mode Inverter Control Test Verification (open access)

Dual Mode Inverter Control Test Verification

Permanent Magnet Motors with either sinusoidal back emf (permanent magnet synchronous motor [PMSM]) or trapezoidal back emf (brushless dc motor [BDCM]) do not have the ability to alter the air gap flux density (field weakening). Since the back emf increases with speed, the system must be designed to operate with the voltage obtained at its highest speed. Oak Ridge National Laboratory's (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) has developed a dual mode inverter controller (DMIC) that overcomes this disadvantage. This report summarizes the results of tests to verify its operation. The standard PEEMRC 75 kW hard-switched inverter was modified to implement the field weakening procedure (silicon controlled rectifier enabled phase advance). A 49.5 hp motor rated at 2800 rpm was derated to a base of 400 rpm and 7.5 hp. The load developed by a Kahn Industries hydraulic dynamometer, was measured with a MCRT9-02TS Himmelstein and Company torque meter. At the base conditions a current of 212 amperes produced the 7.5 hp. Tests were run at 400, 1215, and 2424 rpm. In each run, the current was no greater than 214 amperes. The horsepower obtained in the three runs were 7.5, 9.3, and 8.12. These results verified …
Date: April 25, 2001
Creator: Bailey, J.M.
Object Type: Report
System: The UNT Digital Library
Testing of an Echelle Spectrometer as a LIBS Detector at Sandia (open access)

Testing of an Echelle Spectrometer as a LIBS Detector at Sandia

Some useful information has been obtained regarding the potential use of the echelle spectrometer system for Laser-Induced Breakdown Spectroscopy (LIBS) monitoring applications, despite the AOTF-computer operational problems during the Sandia site-test. Currently, the use of the echelle spectrometer with the LIBS system is not suitable for trace-level analyte detection. This is due, in part, to the lower light throughput of the echelle spectrometer system compared to the SpectraPro-275. The low duty cycle of the LIBS system, which results from the use of a low-repetition-rate (but low-cost and portable) laser, also limits the detection sensitivity achievable using a high-resolution spectrometer. At high analyte concentrations, the echelle spectrometer is able to resolve spectral interferences including the Cd-As line pair at 228.8-nm and other LIBS emission features not resolved using the SpectraPro-275. A definite positive result obtained is the determination that at the high resolution of the echelle spectrometer, time-gating of the CCD detector is not necessary to discriminate analyte spectral signals from the LIBS background emission. The cost of the gated CCD and associated electronics is a significant portion of the cost of the Sandia LIBS system. Incorporation of a low-cost version of the echelle spectrometer for process monitoring applications not requiring …
Date: April 25, 2001
Creator: Baldwin, David P.; Zamzow, Daniel S.; Ottesen, David K. & Johnsen, Howard A.
Object Type: Report
System: The UNT Digital Library