EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL (open access)

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period March 24, 1999 to September 23, 1999 which covers the last (sixth) six months of the project. During this reporting period, extraction of devolatilization time-scales and temperature data at these time-scales analyzing the high-speed films taken during the experiments was complete. Also a new thermodynamic model was developed to predict the heat transfer behavior for coal particles subjected to a range of heating rates using one approach based on the analogy of polymers. Sensitivity analyses of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 7} K/s. At these heating rates during the early stages within the first few milliseconds of heating time, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are few data available in the coal literature for 10{sup 2}-10{sup 3} K/s obtained by UTRC in their previous studies. These data were obtained for a longer heating …
Date: November 2, 1999
Creator: Sampath, Ramanathan
Object Type: Report
System: The UNT Digital Library
K Basin Fuel Characterization Program Technical Baseline Summary (open access)

K Basin Fuel Characterization Program Technical Baseline Summary

This document provides a summary of the systematic process used by the SNF Project to characterize K-Basin spent fuel, and to develop and apply the appropriate conservative safety margins to the resulting parameters for technical designs and safety analyses.
Date: November 2, 1999
Creator: SUYAMA, R.M.
Object Type: Report
System: The UNT Digital Library
Toward Unraveling the Photochemistry of TATB (open access)

Toward Unraveling the Photochemistry of TATB

A combined theoretical and experimental chemical analysis has been conducted to unravel the mechanism underlying the color change of yellow TATB (1,3,5 triamino-trinitro-benzene) to green upon UV irradiation. There is strong evidence to conclude that the process is photochemical in nature and due to the formation of the mono nitroso derivative. They have identified a chemical synthesis by which this derivative compound can be produced in the laboratory, thus allowing for direct testing and determination of its chemical and physical properties. Calculations also show only a slight decrease in the sensitivity and performance of the irradiated materials, attributed to the formation of this previously unidentified species.
Date: November 2, 1999
Creator: Schmidt, R.; Overturf, G.; Watkins, B. & Fried, L.
Object Type: Report
System: The UNT Digital Library
Uncertainty Propagation in Calibration of Parallel Kinematic Machines (open access)

Uncertainty Propagation in Calibration of Parallel Kinematic Machines

Over the last decade, multi-axis machine tools and robots based on parallel kinematic mechanisms (PKMs) have been developed and marketed worldwide. Positional accuracy in these machines is controlled by accurate knowledge of the kinematic parameters which consists of the joint center locations and distances between joint pairs. Since these machines tend to be rather large in size, the kinematic parameters (joint center locations, and initial strut lengths) are difficult to determine when these machines are in their fully assembled state. Work recently completed by the University of Florida and Sandia National Laboratories has yielded a method for determining all of the kinematic parameters of an assembled parallel kinematic device. This paper contains a brief synopsis of the calibration method created, an error budget, an uncertainty analysis for the recovered kinematic parameters and the propagation of these uncertainties to the tool tip.
Date: November 2, 1999
Creator: JOKIEL JR.,BERNHARD & ZIERGERT,JOHN C.
Object Type: Article
System: The UNT Digital Library
HTS wire irradiation test with 8 GeV protons (open access)

HTS wire irradiation test with 8 GeV protons

The radiation level at High Energy Particle Accelerators (HEPA) is relatively high. Any active component which should be close to the accelerator has to be radiation hard. Since High Temperature Superconductors (HTS) have a great potential to be used in HEPAs (e.g., in superconducting magnets, current leads, RF cavities), it is important to understand the radiation hardness of these materials. A radiation test of HTS wire (Bi-2223) was performed at Fermilab. The HTS sample was irradiated with 8 GeV protons and the relative I{sub c} was measured during the irradiation. The total radiation dose was 10 Mrad, and no I{sub c} degradation was observed.
Date: November 2, 1999
Creator: Feher, S.; Glass, H.; Huang, Y.; Limon, P.J.; Orris, D.F.; Schlabach, P. et al.
Object Type: Article
System: The UNT Digital Library
Materials research institute annual report FY98 (open access)

Materials research institute annual report FY98

The Materials Research Institute (MRI) is the newest of the University/LLNL Institutes and began operating in March 1997. The MRI is one of five Institutes reporting to the LLNL University Relations Program (URP), all of which have as their primary goal to facilitate university interactions at LLNL. This report covers the period from the opening of the MRI through the end of FY98 (September 30, 1998). The purpose of this report is to emphasize both the science that has been accomplished, as well as the LLNL and university people who were involved. The MRI is concentrating on projects, which highlight and utilize the Laboratory's unique facilities and expertise. Our goal is to enable the best university research to enhance Laboratory programs in the area of cutting-edge materials science. The MRI is focusing on three primary areas of materials research: Biomaterials (organic/inorganic interfaces, biomemetic processes, materials with improved biological response, DNA materials science); Electro/Optical Materials (laser materials and nonlinear optical materials, semiconductor devices, nanostructured materials); and Metals/Organics (equation of state of metals, synthesis of unique materials, high explosives/polymers). In particular we are supporting projects that will enable the MRI to begin to make a distinctive name for itself within the scientific …
Date: November 2, 1999
Creator: Radousky, H
Object Type: Report
System: The UNT Digital Library
Steps towards universality of the Chemical Weapons Convention: How can Africa contribute? (open access)

Steps towards universality of the Chemical Weapons Convention: How can Africa contribute?

Universality is a fundamental principal of the Chemical Weapons Convention (CWC). It suffuses the fabric of the Convention, found not only in the very first ringing clauses of Article I, but also in the many technical details of its Annexes and Schedules. Consequently, universality is a topic on which commentary is appropriate from all quarters. The author offers his personal views as a lawyer on this important matter in the hope that, this distinguished audience may gain a perspective not available from practitioners of other professions. The views expressed in this paper are those of the author alone, and do not represent the position of the government of the US or of any other institution.
Date: November 2, 1999
Creator: Tanzman, E.
Object Type: Article
System: The UNT Digital Library
Innovative approach for restoring coastal wetlands using treated drill cuttings (open access)

Innovative approach for restoring coastal wetlands using treated drill cuttings

The leading environmental problem facing coastal Louisiana regions is the loss of wetlands. Oil and gas exploration and production activities have contributed to wetland damage through erosion at numerous sites where canals have been cut through the marsh to access drilling sites. An independent oil and gas producer, working with Southeastern Louisiana University and two oil field service companies, developed a process to stabilize drill cuttings so that they could be used as a substrate to grow wetlands vegetation. The U.S. Department of Energy (DOE) funded a project under which the process would be validated through laboratory studies and field demonstrations. The laboratory studies demonstrated that treated drill cuttings support the growth of wetlands vegetation. However, neither the Army Corps of Engineers (COE) nor the U.S. Environmental Protection Agency (EPA) would grant regulatory approval for afield trial of the process. Argonne National Laboratory was asked to join the project team to try to find alternative mechanisms for gaining regulatory approval. Argonne worked with EPA's Office of Reinvention and learned that EPA's Project XL would be the only regulatory program under which the proposed field trial could be done. One of the main criteria for an acceptable Project XL proposal is …
Date: November 2, 1999
Creator: Veil, J. A. & Hocking, E. K.
Object Type: Article
System: The UNT Digital Library
EPICS and its role in data acquisition and beamline control. (open access)

EPICS and its role in data acquisition and beamline control.

Beamline-control and data-acquisition software based on EPICS (a tool kit for building distributed control systems) has been running on many Advanced Photon Source beamlines for several years. EPICS itself, the collaborative software-development effort surrounding it, and EPICS-based beamline software have been described previously in general terms. This talk will review and update that material, focusing on the role EPICS core software plays in beamline applications and on the effects of a few defining characteristics of EPICS on the beamline software we have developed with it.
Date: November 2, 1999
Creator: Mooney, T. M.; Arnold, N. D.; Boucher, E.; Cha, B. K.; Goetze, K. A.; Kraimer, M. R. et al.
Object Type: Article
System: The UNT Digital Library
Effect of focusing optics on x-ray speckle contrast (open access)

Effect of focusing optics on x-ray speckle contrast

The authors investigated the behavior of speckle contrast and size under various experimental conditions using 1.82 keV x-rays. In this paper, they report the comparison of two different setups for x-ray speckle experiments: one employing a focusing zone plate and one in which a pinhole selects the size of the coherent x-ray beam. They found a strong dependence of the speckle contrast and size on the type of setup. In general, the pinhole setup results in higher contrast but smaller speckle size. On the other hand the zone plate setup allows one to target much smaller areas of interest in the sample, down to submicron dimensions, and also to adjust the speckle size. The authors anticipate that these results will be useful in future time-correlation spectroscopy experiments.
Date: November 2, 1999
Creator: Retsch, C. C.; Wang, Y.; Frigo, S. P.; McNulty, I.; Lurio, L. B. & Stephenson, G. B.
Object Type: Article
System: The UNT Digital Library
High-resolution x-ray imaging for microbiology at the Advanced Photon Source (open access)

High-resolution x-ray imaging for microbiology at the Advanced Photon Source

Exciting new applications of high-resolution x-ray imaging have emerged recently due to major advances in high-brilliance synchrotrons sources and high-performance zone plate optics. Imaging with submicron resolution is now routine with hard x-rays: the authors have demonstrated 150 run in the 6--10 keV range with x-ray microscopes at the Advanced Photon Source (APS), a third-generation synchrotrons radiation facility. This has fueled interest in using x-ray imaging in applications ranging from the biomedical, environmental, and materials science fields to the microelectronics industry. One important application they have pursued at the APS is a study of the microbiology of bacteria and their associated extracellular material (biofilms) using fluorescence microanalysis. No microscopy techniques were previously available with sufficient resolution to study live bacteria ({approx}1 {micro}m x 4 {micro}m in size) and biofilms in their natural hydrated state with better than part-per-million elemental sensitivity and the capability of determining g chemical speciation. In vivo x-ray imaging minimizes artifacts due to sample fixation, drying, and staining. This provides key insights into the transport of metal contaminants by bacteria in the environment and potential new designs for remediation and sequestration strategies.
Date: November 2, 1999
Creator: Lai, B.; Kemner, K. M.; Maser, J.; Schneegurt, M. A.; Cai, Z.; Ilinski, P. P. et al.
Object Type: Article
System: The UNT Digital Library
Rapidly-Solidified Permanent Magnet Materials: Factors Affecting Quenchability and Magnetic Properties in Nd{Sub 2}Fe{Sub 14}B (open access)

Rapidly-Solidified Permanent Magnet Materials: Factors Affecting Quenchability and Magnetic Properties in Nd{Sub 2}Fe{Sub 14}B

Insight into the solidification behavior of Nd{sub 2}Fe{sub 14}B-based materials processed by rapid solidification techniques has been obtained by a systematic experimental study of the Curie temperatures of selected phases found in these materials. Nd{sub 2}Fe{sub 14}B-based materials fabricated by two disparate rapid solidification techniques, inert gas atomization (IGA) and melt-spinning, has been studied. The compositions of the starting materials have been altered with additions of the refractory elements Ti and C which are known to alter the solidification behavior of these materials. Special emphasis has been placed on trying to understand the effect of alloying additions upon the nature of the quenched glass, the distribution of the elemental additions within the Nd{sub 2}Fe{sub 14}B lattice and the evolution of the elemental partitioning with quench rate and annealing condition. The experimental Curie temperature data obtained using thermal analysis methods from the particles produced by gas-atomization is consistent with both an ejection of quenched-in refractory species from the crystalline Nd{sub 2}Fe{sub 14}B lattice and with increased crystallographic order as particle size, and hence grain size, increases. Magnetic ac susceptibility measurements performed on nominally-amorphous Nd{sub 2}Fe{sub 14}B ribbons produced by melt-spinning indicate a decrease of the Curie temperature with increasing quench rate, …
Date: November 2, 1999
Creator: Lewis, L. H.; Kramer, M. J.; Mccallum, R. W. & Branagan, D. J.
Object Type: Article
System: The UNT Digital Library
Polymeric Carbon Dioxide (open access)

Polymeric Carbon Dioxide

Synthesis of polymeric carbon dioxide has long been of interest to many chemists and materials scientists. Very recently we discovered the polymeric phase of carbon dioxide (called CO{sub 2}-V) at high pressures and temperatures. Our optical and x-ray results indicate that CO{sub 2}-V is optically non-linear, generating the second harmonic of Nd: YLF laser at 527 nm and is also likely superhard similar to cubic-boron nitride or diamond. CO{sub 2}-V is made of CO{sub 4} tetrahedra, analogous to SiO{sub 2} polymorphs, and is quenchable at ambient temperature at pressures above 1 GPa. In this paper, we describe the pressure-induced polymerization of carbon dioxide together with the stability, structure, and mechanical and optical properties of polymeric CO{sub 2}-V. We also present some implications of polymeric CO{sub 2} for high-pressure chemistry and new materials synthesis.
Date: November 2, 1999
Creator: Yoo, C. S.
Object Type: Article
System: The UNT Digital Library
Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in-situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy (open access)

Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in-situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy

Hydrogen can be absorbed in large quantities by 100 {angstrom} thin Nb layers embedded in epitaxial W/Nb and polycrystalline Fe/Nb multilayers. The solubility and the hydrogen-induced structural changes of the host lattice are explored in-situ by small-angle neutron/X-ray reflectometry and high-angle diffraction. These measurements reveal for both systems that the relative out-of-plane expansion of the Nb layers is considerably larger than the relative increase of the Nb interplanar spacing indicating two distinctly different mechanisms of hydrogen absorption. In Fe/Nb multilayers, hydrogen expands the Nb interplanar spacing in a continuous way as function of the external pressure. In contrast, the Nb lattice expansion is discontinuous in epitaxial W/Nb multilayers: A jump in the Nb(002) Bragg reflection position occurs at a critical hydrogen pressure of 1 mbar. In-situ EXAFS spectroscopy also exhibits an irreversible expansion of the Nb lattice in the film plane for p{sub H{sub 2}}> 1 mbar. This can be regarded as a structural phase transition from an exclusively out-of-plane to a three-dimensionally expanded state at low and high hydrogen pressures, respectively.
Date: November 2, 1999
Creator: Klose, F.; Rehm, C.; Fieber-Erdmann, M.; Holub-Krappe, E.; Bleif, H. J.; Sowers, H. et al.
Object Type: Article
System: The UNT Digital Library
Initiation in H{sub 2}/O{sub 2}: Rate constants for H{sub 2} + O{sub 2} {yields} H + HO{sub 2} at high temperature (open access)

Initiation in H{sub 2}/O{sub 2}: Rate constants for H{sub 2} + O{sub 2} {yields} H + HO{sub 2} at high temperature

The reaction between H{sub 2} and O{sub 2} has been studied in a reflected shock tube apparatus between 1662--2097 K. O-atom atomic resonance absorption spectrometry (ARAS) was used to observe absolute [O]{sub t} under conditions of low [H{sub 2}]{sub 0} so that most secondary reactions were negligible. Hence, the observed [O]{sub t}, was the direct result of the rate controlling reaction between H{sub 2} and O{sub 2}. Three different reactions were considered, but experimental and ab initio theoretical results both indicated that the process, H{sub 2} + O{sub 2} {yields} H + HO{sub 2}, is the only possible reaction. After rapid HO{sub 2} dissociation, O-atoms are then instantaneously produced by H + O{sub 2} {yields} O + OH. Using the ab initio result, conventional transition state theoretical calculations (CTST) with tunneling corrections give the expression: k = 1.228 x 10{sup {minus}18} T{sup 2.4328} exp({minus}26926 K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, applicable between 400 and 2,300 K. This theoretical result agrees with the present experimental determinations and those at lower temperature, derived from earlier work on the reverse reaction.
Date: November 2, 1999
Creator: Michael, J. V.; Sutherland, J. W.; Harding, L. B. & Wagner, A. F.
Object Type: Article
System: The UNT Digital Library
Steady state and transient current lead analysis (open access)

Steady state and transient current lead analysis

A mathematical model of the gas-cooled, resistive portion of a binary current lead has been developed. An analytical solution of the time-dependent differential equations for the resistive portion of the forced low cooled current lead is presented which allows one to calculate the evolution of the temperature profile and voltage drop. A comparison of analytical with numerical calculations and a comparison of the calculations with experimental data are given.
Date: November 2, 1999
Creator: G. Citver, E. Barzi, A. Burov, S. Feher, P.J. Limon and T. Peterson
Object Type: Article
System: The UNT Digital Library
Assessing economic impacts of clean diesel engines. Phase 1 report: U.S.- or foreign-produced clean diesel engines for selected light trucks (open access)

Assessing economic impacts of clean diesel engines. Phase 1 report: U.S.- or foreign-produced clean diesel engines for selected light trucks

Light trucks' share of the US light vehicle market rose from 20% in 1980 to 41% in 1996. By 1996, annual energy consumption for light trucks was 6.0 x 10{sup 15} Btu (quadrillion Btu, or quad), compared with 7.9 quad for cars. Gasoline engines, used in almost 99% of light trucks, do not meet the Corporate Average Fuel Economy (CAFE) standards. These engines have poor fuel economy, many getting only 10--12 miles per gallon. Diesel engines, despite their much better fuel economy, had not been preferred by US light truck manufacturers because of problems with high NO{sub x} and particulate emissions. The US Department of Energy, Office of Heavy Vehicle Technologies, has funded research projects at several leading engine makers to develop a new low-emission, high-efficiency advanced diesel engine, first for large trucks, then for light trucks. Recent advances in diesel engine technology may overcome the NO{sub x} and particulate problems. Two plausible alternative clean diesel (CD) engine market penetration trajectories were developed, representing an optimistic case (High Case) and an industry response to meet the CAFE standards (CAFE Case). However, leadership in the technology to produce a successful small, advanced diesel engine for light trucks is an open issue …
Date: November 2, 1999
Creator: Teotia, A.P.; Vyas, A.D.; Cuenca, R.M. & Stodolsky, F.
Object Type: Report
System: The UNT Digital Library
A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the Advanced Photon Source (open access)

A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the Advanced Photon Source

A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 {micro}m (v) x 0.6 {micro}m (h), and a photon flux of 4 x 10{sup 9} photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 {micro}m in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (L{sub a} line) of 80 attograms/{micro}m{sup 2} for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique.
Date: November 2, 1999
Creator: Cai, L.; Lai, B.; Yun, W.; Ilinski, P.; Legnini, D.; Maser, J. et al.
Object Type: Article
System: The UNT Digital Library
Downhole oil/water separators offer lower costs and greater environmental protection (open access)

Downhole oil/water separators offer lower costs and greater environmental protection

Produced water management can be a significant expense for oil and gas operators. This paper summarizes a study of the technical, economic, and regulatory feasibility of a relatively new technology, downhole oil/water separators (DOWS), to reduce the volume of water pumped to the surface. The study was funded by the US Department of Energy and conducted by Argonne National Laboratory, CH2M Hill, and the Nebraska Oil and Gas Conservation Commission. DOWS are devices that separate oil and gas from produced water at the bottom of the well and reinject some of the produced water into another formation or another horizon within the same formation, while the oil and gas are pumped to the surface. Since much of the produced water is not pumped to the surface, treated, and pumped from the surface back into a deep formation, the cost of handling produced water is greatly reduced. The oil production rate has increased for more than half of the DOWS installations to date.
Date: November 2, 1999
Creator: Veil, J. A.
Object Type: Article
System: The UNT Digital Library
Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah (open access)

Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah

The primary objective of this project is to enhance domestic petroleum production by field demonstration and technology transfer of an advanced- oil-recovery technology in the Paradox basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m3) of oil. This project is designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-(CO2-) miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah.
Date: November 2, 1999
Creator: Chidsey, Thomas C., Jr. & Allison, M. Lee
Object Type: Report
System: The UNT Digital Library