States

Ferredoxin-linked chloreplast enzymes. Progress report, August 15, 1990--August 14, 1993 (open access)

Ferredoxin-linked chloreplast enzymes. Progress report, August 15, 1990--August 14, 1993

Progress has clearly been made on all of the goals set forth in the original proposal. Although the monoclonal antibodies raised against FNR turned out no to be useful for mapping the FNR/ferredoxin or FNR/NADP+ interaction domains, good progress has been made on mapping the FNR/ferredoxin interaction domains by an alternative technique, differential chemical modification. Furthermore, the techniques developed for differential chemical modifications of these two proteins - taurine modification of aspartate and glutamate residues and biotin modification of lysine residues - should be useful for mapping the interaction domains of many proteins that associate through electrostatic interactions. Finally, progress has also been made with respect to another ferredoxin-dependent enzyme involved in the earliest steps of plant nitrogen metabolism - nitrite reductase. Questions concerning the subunit composition and heme content of the enzyme have been resolved and evidence demonstrating the involvement of lysine and arginine residues in binding ferredoxin has been obtained for the first time.
Date: January 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 1, May--July, 1994 (open access)

Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 1, May--July, 1994

This report describes the progress made during the first Quarter of a two year project to demonstrate that the air pollution from a traveling grate stoker being used to heat water at a central heating plant in Krakow Poland can be reduced significantly by replacing the unwashed, unsized coal now being used with a mechanically cleaned, double sized stoker fuel and by optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost effective and hence be adopted in the other central heating plants in Krakow and indeed throughout Eastern European cities where coal is the primary source of heating fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC a central heating company in Krakow and Naftokrak-Naftobudowa, preparation plant designers and fabricators, for this effort. An evaluation of the washability characteristics of five samples of two coals (Piast and Janina) showed that {open_quotes}compliance-quality{close_quotes} stoker coals could be produced which contained less than 640 g of SO{sub 2}/KJ (1.5 lbs SO{sub 2}/MMBtu) at acceptable plant yields by washing in heavy media cyclones. A search for long-term sources of raw coal to feed the proposed new 300 tph stoker coal …
Date: January 1, 1996
Creator: Rozelle, P.
Object Type: Report
System: The UNT Digital Library
Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 6, October 1993--December 1993 (open access)

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 6, October 1993--December 1993

Elemental sulfur recovery from SO{sub 2}-containing gas stream is highly attractive as it produces a salable product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO{sub 2} with coke) and Claus plant (reaction of SO{sub 2} with H{sub 2}S over catalyst). This project will investigate a cerium oxide catalyst for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified in recent work at MIT as a superior catalyst for SO{sub 2} reduction by CO to elemental sulfur because its high activity and high selectivity to sulfur over COS over a wide temperature range(400-650 {degrees}C). The detailed kinetic and parametric studies of SO{sub 2} reduction planned in this work over various CeO{sub 2}-formulations will provide the necessary basis for development of a very simplified process, namely that of a single-stage elemental sulfur recovery scheme from variable concentration gas streams. The potential cost- and energy-efficiency benefits from this approach can not be overstated. A first apparent application is treatment of a regenerator off-gases in power plants using regenerative flue gas desulfurization. …
Date: January 1, 1996
Creator: Liu, W.; Flytzani-Stephanopoulos, M. & Sarofim, A. F.
Object Type: Report
System: The UNT Digital Library
An experimental evaluation of the instrumented flux synthesis method for the real-time estimation of reactivity. Final report (open access)

An experimental evaluation of the instrumented flux synthesis method for the real-time estimation of reactivity. Final report

One method of determining the flux density is flux synthesis which approximates the flux in the core by linear combinations of precomputed shape functions. In traditional flux synthesis, the unknown mixing coefficients are determined using a weighted residual method of solving the diffusion equation. In the instrumented synthesis method, the mixing coefficients are determined using count rates from neutron detectors in the core. In this way the mixing coefficients are linked to conditions in the reactor. Using the synthesized flux, kinetics parameters, notably reactivity, can be calculated in real time. An experimental evaluation has been performed in the Massachusetts Institute of Technology Reactor, MITR-II. Detector measurements have been collected using fission chambers placed at the periphery of the core. The reactor was put into a number of various conditions, both static and transient, and data were collected using a digital acquisition system for later combination with shape functions. Transients included increasing power, decreasing power, and a reactor scram. The shape functions were generated using Version 3.0 of the QUARTZ code, a quadratic nodal diffusion theory code in triangular-Z geometry. Supernodal analysis algorithms have been added to the original program, along with subroutines to guarantee diagonal dominance of the leakage matrix …
Date: January 1, 1996
Creator: Hughes, Jeffrey C.; Henry, Allan F.; Lanning, David D. & Bernard, John A.
Object Type: Report
System: The UNT Digital Library
The evaluation of a turbulent loads characterization system (open access)

The evaluation of a turbulent loads characterization system

In this paper we discuss an on-line turbulent load characterization system that has been designed to acquire loading spectra from turbines of the same design operating in several different environments and from different turbine designs operating in the same environment. This System simultaneously measures the rainflow-counted alternating and mean loading spectra and the hub-height turbulent mean shearing stress and atmospheric stability associated with the turbulent inflow. We discuss the theory behind the measurement configuration and the results of proof-of-concept testing recently performed at the National Wind Technology Center (NWTC) using a Bergey EXCEL-S 10-kW wind turbine. The on-line approach to characterizing the load spectra and the inflow turbulent scaling parameter produces results that are consistent with other measurements. The on-line approximation of the turbulent shear stress or friction velocity u* also is considered adequate. The system can be used to characterize turbulence loads during turbine deployment in a wide variety of environments. Using the WISPER protocol, we found that a wide-range, variable-speed turbine will accumulate a larger number of stress cycles in the low-cycle, high-amplitude (LCHA) region when compared with a constant speed rotor under similar inflow conditions.
Date: January 1, 1996
Creator: Kelley, Neil D. & McKenna, H. Edward
Object Type: Article
System: The UNT Digital Library
Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, July 1, 1995--September 30, 1995 (open access)

Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, July 1, 1995--September 30, 1995

Comprehensive experimentation has been conducted to determine whether circulating fluidized bed (CFB) pressure fluctuations can be used to verify that similitude conditions in circulating fluidized beds have been achieved. Using two geometrically similar CFB models, pressure fluctuations were recorded while the full set of similitude parameters were matched under a broad range of operating conditions. The method of data acquisition and analysis is shown to be very important in order to observe the significant frequency phenomena. Under relatively dilute conditions similar power spectral density and Bode plot profiles are observed in the two geometrically similar beds. The dominant frequency under these dilute conditions is inversely proportional to the characteristic CFB dimension. Under conditions of higher solids loading, an additional lower bed frequency phenomena is observed in the spectrum which may be a function of the depth of the lower dense bed in the CFB. It is evident from the results that under some operating conditions, a single dimensionless frequency is not sufficient to validate the achievement of similitude using pressure fluctuations. The results also suggest that the use of similitude parameters as they are currently defined is limited to dilute operating conditions, prior to the formation of a lower dense …
Date: January 1, 1996
Creator: Brown, R.C.
Object Type: Report
System: The UNT Digital Library
Stanford Synchrotron Radiation Laboratory. Activity report for 1989 (open access)

Stanford Synchrotron Radiation Laboratory. Activity report for 1989

The April, 1990 SPEAR synchrotron radiation run was one of the two or three best in SSRL`s history. High currents were accumulated, ramping went easily, lifetimes were long, beam dumps were infrequent and the average current was 42.9 milliamps. In the one month of operation, 63 different experiments involving 208 scientists from 50 institutions received beam. The end-of-run summary forms completed by the experimenters indicated high levels of user satisfaction with the beam quality and with the outstanding support received from the SSRL technical and scientific staffs. These fine experimental conditions result largely from the SPEAR repairs and improvements performed during the past year and described in Section I. Also quite significant was Max Cornacchia`s leadership of the SLAG staff. SPEAR`s performance this past April stands in marked contrast to that of the January-March, 1989 run which is also described in Section I. It is, we hope, a harbinger of the operation which will be provided in FY `91, when the SPEAR injector project is completed and SPEAR is fully dedicated to synchrotron radiation research. Over the coming years, SSRL intends to give highest priority to increasing the effectiveness of SPEAR and its various beam lines. The beam line and …
Date: January 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 4, January--March, 1995 (open access)

Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 4, January--March, 1995

This report describes the progress made during this reporting period of a two year project to demonstrate that the air pollution from a traveling-grate stoker being used to heat water at a central heating plant in Krakow, Poland can be reduced significantly by (1) substituting the unwashed, unsized coal currently being used with a mechanically cleaned, double-sized stoker fuel and by (2) optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost-effective and hence will be adopted by the other central heating plants in Krakow and ideally, throughout Eastern European cities where coal continues to be the primary source of fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC, a central heating company in Krakow, and Naftokrak-Naftobudowa, preparation plant designers and fabricators-for the execution of this effort. Five potential candidate sources have been located and contracts for coal deliveries should be executed early next quarter. TInitial delays in formalizing the EFH/Polish Partners agreement delayed finalizing the coal supply contracts and hence, precluded collecting the Polish coal samples for characterization and combustion performance studies. Work on this Task will be initialed next quarter after the raw coal supply …
Date: January 1, 1996
Creator: Rozelle, P.
Object Type: Report
System: The UNT Digital Library
Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 3, November--December 1994 (open access)

Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 3, November--December 1994

This report describes the progress made during this reporting period of a two year project to demonstrate that the air pollution from a traveling grate stoker being used to heat water at a central heating plant in Krakow, Poland can be reduced significantly by (1) substituting the unwashed, unsized coal currently being used with a mechanically cleaned, double-sized stoker fuel and by (2) optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost effective and hence be adopted by the other central heating plants in Krakow and indeed, throughout Eastern European cities where coal continues to be the primary source of fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC, a central heating company in Krakow, and Naftokrak-Naftobudowa, preparation plant designers and fabricators, for the execution of this effort. The washability data from a 20mm x 0.5mm size fraction of raw coal from the Nikwa Modrejow Mine were evaluated. The data show that the ash content of this coal can be reduced from 34.0 percent to 9.0 percent by washing in a heavy-media cyclone at 1.725 sp.gr.; the actual yield of clean coal would be 63.1 percent. …
Date: January 1, 1996
Creator: Rozelle, P.
Object Type: Report
System: The UNT Digital Library
1990 Activity report for 1986-1992 (open access)

1990 Activity report for 1986-1992

As discussed in last year`s Activity Report, a fairly complete analysis of SPEAR problems was performed in concert with SLAC, and a major maintenance/improvement process was initiated in the spring of 1989. This run made it apparent that SPEAR will remain a very useful and impressive synchrotron radiation storage ring for at least a decade, given a steady maintenance and improvement program. More details about SPEAR functioning during the run, as well as SPEAR improvements, are contained in Chapter I. The formal SPEAR injector construction project was completed in November, 1990, on-time and on-budget. Although DOE was not able to provide anticipated FY90 commissioning funds, preliminary commissioning was performed and 2.3 GeV injection to SPEAR was demonstrated. A discussion of the Injector project is contained in Chapter II. Commissioning of the injector and the injector/SPEAR complex is continuing in 1991 with Users participating during the May-September period. This user participation allowed normal experimentation, so that systems could be tested critically, but with the commissioning process having higher priority than data acquisition. Another major event in 1990 was the full dedication of SPEAR to the synchrotron radiation program. Previously SPEAR was considered a high energy physics machine that was partially dedicated …
Date: January 1, 1996
Creator: Cantwell, K.
Object Type: Report
System: The UNT Digital Library
Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 2, August--October, 1994 (open access)

Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 2, August--October, 1994

This report describes the progress made during the second Quarter of a two year project to demonstrate that the air pollution, from a traveling grate stoker being used to heat water at a central heating plant in Krakow Poland, can be reduced significantly by replacing the unwashed, unsized coal now being used with a mechanically cleaned, double sized stoker fuel and by optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost effective and hence be adopted in the other central heating plants in Krakow and indeed throughout Eastern European cities where coal is the primary source of heating fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC a central heating company in Krakow and Naftokrak-Naftobudowa, preparation plant designers and fabricators for this effort. The washability data from a 20mm x 0.5mm size fraction of raw coal from the Staszic Mine were evaluated. The data show that the ash content of this coal can be reduced from 24.4 percent to 6.24 percent by washing in a heavy media cyclone at 1.825 sp.gr.; the actual yield of clean coal would be 76.1 percent. The quest for long-term sources …
Date: January 1, 1996
Creator: Rozelle, P.
Object Type: Report
System: The UNT Digital Library
Stanford Synchrotron Radiation Laboratory. Activity report for 1988 (open access)

Stanford Synchrotron Radiation Laboratory. Activity report for 1988

For SSRL operations, 1988 was a year of stark contrasts. The first extended PEP parasitic running since the construction of our two beam lines on that storage ring took place in November and December. Four experiments discussed below, were performed and detailed operational procedures which allowed synchrotron radiation an high energy users to coexist were established. SSRL anticipates that there will be significant amounts of beam time when PEP is run again for high energy physics. On the other hand, activity on SPEAR consisted of brief parasitic running on the VUV lines in December when the ring was operated at 1.85 GeV for colliding beam experiments. There was no dedicated SPEAR running throughout the entire calendar year. This is the first time since dedicated SPEAR operation was initiated in 1980 that there was no such running. The decision was motivated by both cost and performance factors, as discussed in Section 1 of this report. Fortunately, SLAC and SSRL have reached an agreement on SPEAR and PEP dedicated time charges which eliminates the cost volatility which was so important in the cancellation of the June-July dedicated SPEAR run. As discussed in Section 2, the 3 GeV SPEAR injector construction is proceeding …
Date: January 1, 1996
Creator: Cantwell, K.
Object Type: Report
System: The UNT Digital Library
A systematic look at Tank Waste Remediation System privatization (open access)

A systematic look at Tank Waste Remediation System privatization

The mission of the Tank Waste Remediation System (TWRS) Program is to store, treat, immobilize, and dispose, or prepare for disposal, the Hanford radioactive tank waste in an environmentally sound, safe, and cost effective manner. Highly radioactive Hanford waste includes current and future tank waste plus the cesium and strontium capsules. In the TWRS program, as in other Department of Energy (DOE) clean-up activities, there is an increasing gap between the estimated funding required to enable DOE to meet all of its clean-up commitments and level of funding that is perceived to be available. Privatization is one contracting/management approach being explored by DOE as a means to achieve cost reductions and as a means to achieve a more outcome-oriented program. Privatization introduces the element of competition, a proven means of establishing true cost as well as achieving significant cost reduction.
Date: January 1, 1996
Creator: Holbrook, J. H.; Duffy, M. A.; Vieth, D. L. & Sohn, C. L.
Object Type: Report
System: The UNT Digital Library
Optical Properties of Epitaxial Plt Thin Films (open access)

Optical Properties of Epitaxial Plt Thin Films

Metalorganic chemical vapor deposition was used to prepare epitaxial or highly oriented PLT (Pb{sub 1-x}La{sub x}TiO{sub 3}) thin films with x = 0.21-0.34. The growth of PLT films resulted in 3-D epitaxial heterostructures on a (100) surface of both MgO and KTaO{sub 3} substrates. The PLT film grown on a KTaO{sub 3} (100) substrate has a significantly lower minimum channeling yield compared to that grown on the MgO (100) substrate because of the smaller lattice mismatch associated with KTaO{sub 3}. Thickness and refractive indices at 435-1523 nm were measured by prism coupling. Measured film thickness of 570 nm was in good agreement with that obtained from RBS. Refractive index of the PLT film is smaller than that of PbTiO{sub 3}, and its difference at {lambda} = 632.8 nm is about 2.5%. Dispersion of the refractive index was well fitted by a Sellmeier dispersion formula.
Date: January 1, 1996
Creator: Kim, Y.; Erbil, A.; Boatner, L. A.; Steingart, L.; Mensah, T. & Hiamang, S.
Object Type: Article
System: The UNT Digital Library
The Influence of Salt Aerosol on Alpha Radiation Detection by Wipp Continuous Air Monitors (open access)

The Influence of Salt Aerosol on Alpha Radiation Detection by Wipp Continuous Air Monitors

Alpha continuous air monitors (CAMs) will be used at the Waste Isolation Pilot Plant (WIPP) to measure airborne transuranic radioactivity that might be present in air exhaust or in work-place areas. WIPP CAMs are important to health and safety because they are used to alert workers to airborne radioactivity, to actuate air-effluent filtration systems, and to detect airborne radioactivity so that the radioactivity can be confined in a limited area. In 1993, the Environmental Evaluation Group (EEG) reported that CAM operational performance was affected by salt aerosol, and subsequently, the WIPP CAM design and usage were modified. In this report, operational data and current theories on aerosol collection were reviewed to determine CAM quantitative performance limitations. Since 1993, the overall CAM performance appears to have improved, but anomalous alpha spectra are present when sampling-filter salt deposits are at normal to high levels. This report shows that sampling-filter salt deposits directly affect radon-thoron daughter alpha spectra and overall monitor efficiency. Previously it was assumed that aerosol was mechanically collected on the surface of CAM sampling filters, but this review suggests that electrostatic and other particle collection mechanisms are more important than previously thought. The mechanism of sampling-filter particle collection is critical …
Date: January 1, 1996
Creator: Bartlett, W. T. & Walker, B. A.
Object Type: Report
System: The UNT Digital Library
Setting standards for radiation protection: A time for change (open access)

Setting standards for radiation protection: A time for change

In 1950, the International Commission on Radiation Protection (ICRP) recommended that ``certain radiation effects are irreversible and cumulative.`` Furthermore, the ICRP ``strongly recommended that every effort be made to reduce exposures to all types of ionizing radiations to the lowest possible level.`` Then in 1954, the ICRP published its assumption that human response to ionizing radiation was linear with dose, together with the recommendation that exposures be kept as low as practicable. These concepts are still the foundation of radiation protection policy today, even though, as Evans has stated, ``The linear non-threshold (LNT) model was adopted specifically on a basis of mathematical simplicity, not from radio-biological data.... Groups responsible for setting standards for radiation protection should be abreast of new developments and new data as they are published; however, this does not seem to be the case. For example, there have been many reports in scientific, peer-reviewed, and other publications during the last three decades that have shown the LNT model and the policy of As Low As Reasonably Achievable (ALARA) to be invalid. However, none of these reports has been refuted or even discussed by standard-setting groups. We believe this mandates a change in the standard-setting process.
Date: January 1, 1996
Creator: Patterson, H. Wade & Hickman, David P.
Object Type: Article
System: The UNT Digital Library
Fuzzy logic and a risk-based graded approach for developing S/RIDs: An introduction (open access)

Fuzzy logic and a risk-based graded approach for developing S/RIDs: An introduction

A Standards/Requirements Identification Document (S/RID) is the set of expressed performance expectations, or standards, for a facility. Critical to the development of an integrated standards-based management is the identification of a set of necessary and sufficient standards from a selected set of standards/requirements. There is a need for a formal, rigorous selection process for the S/RIDs. This is the first of three reports that develop a fuzzy logic selection process. In this report the fundamentals of fuzzy logic are discussed as they apply to a risk-based graded approach.
Date: January 1, 1996
Creator: Wayland, J. R.
Object Type: Report
System: The UNT Digital Library
Evaluation of Smart Gun Technologies preliminary report (open access)

Evaluation of Smart Gun Technologies preliminary report

The Smart Gun Technology Project has a goal to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing {open_quote}smart{close_quote} technologies. Smart technologies are those that can in some manner identify an officer. This report will identify, describe, and grade various technologies as compared to the requirements that were obtained from officers. This report does not make a final recommendation for a smart gun technology, nor does it give the complete design of a smart gun system.
Date: January 1, 1996
Creator: Weiss, D. R.
Object Type: Report
System: The UNT Digital Library
Title list of documents made publicly available, November 1-30, 1995 (open access)

Title list of documents made publicly available, November 1-30, 1995

The Title List of Documents Made Publicly Available is a monthly publication. It contains descriptions of the information received and generated by the U.S. Nuclear Regulatory Commission (NRC). This information includes (1) docketed material associated with civilian nuclear power plants and other uses of radioactive materials and (2) nondocketed material received and generated by NRC pertinent to its role as a regulatory agency. As used here, docketed does not refer to Court dockets; it refers to the system by which NRC maintains its regulatory records. This series of documents is indexed by a Personal Author Index, a Corporate Source Index and a Report Number Index. The docketed information contained in the Title List includes the information formerly issued through the Department of Energy publication Power Reactor Docker Information, last published in January 1979. NRC documents that are publicly available may be examined without charge at the NRC Public Document Room (PDR). Duplicate copies may be obtained for a fee. Standing orders for certain categories of documents are also available. Clients may search for and order desired titles through the PDR computerized Bibliographic Retrieval System, which is accessible both at the PDR and remotely. The PDR is staffed by professional technical …
Date: January 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Capacitive deionization of NH{sub 4}CIO{sub 4} solutions with carbon aerogel electrodes. Revision 1 (open access)

Capacitive deionization of NH{sub 4}CIO{sub 4} solutions with carbon aerogel electrodes. Revision 1

A process for capacitive deionization of water with a stack of carbon aerogel electrodes was developed. Unlike ion exchange, one of the more conventional deionization processes, no chemicals are required for regeneration of the system; electricity is used instead. An aqueous solution of NH{sub 4}ClO{sub 4} is pumped through the electrochemical cell. After polarization, NH{sub 4}{sup +} and ClO{sub 4}{sup -} ions are removed from the water by the imposed electric field and trapped in the extensive cathodic and anodic double layers. Thsi process produces one stream of purified water and a second stream of concentrate. Effects of cell voltage, salt concentration, and cycling on electrosorption capacity were studied and results reported.
Date: January 1, 1996
Creator: Farmer, J. C.; Fix, D. V.; Mack, G. V.; Pekala, R. W. & Poco, J. F.
Object Type: Article
System: The UNT Digital Library
The solan digital sky suvey (open access)

The solan digital sky suvey

A description is provided for the planned Sloan Digital Sky Survey (SDSS) designed to replace and supplement the Palomar Sky Survey used broadly in cosmology for the past four decades. The SDSS will employ CCD detectors to achieve orders of magnitude increases sensitivity over photographic plates used in the Palomar survey. Described herein are plans for and expected results to be gained from the survey. Detailed descriptions of the design and construction of the SDSS Telescope at Apache Point Observatory, NM. and the spectrographs to be used are also provided.
Date: January 1, 1996
Creator: Nash, T.
Object Type: Article
System: The UNT Digital Library
The role of pore structure on char reactivity. Quarterly progress report, [October--December 1995] (open access)

The role of pore structure on char reactivity. Quarterly progress report, [October--December 1995]

In order to examine the role of pore structure, studies will be conducted on coal chars in the electrodynamic balance. Larger particles will also be examined using a fluidized bed to examine diffusion control reactions, and soots will also be investigated to examine the role of meso- and micro-pores without macro-pore interference. These studies will allow a full range of particles sizes and temperatures to be investigated and eventually modelled. The project has examined the effect of the pore structure diffusivity changes on the generation of NO{sub x} and N{sub 2}O from the Fluidized Bed Combustor. Furthermore, refinement of the techniques necessary to determine micropore characteristics from TEM imaging have been further refined. The continuing focus of this research has been the examination of the evolution of model compounds such as spherocarbon during oxidation in order to simplify structural analysis. The structure of spherocarbon now has been fully analyzed at three conversions (0, 44, and 96% conversion).
Date: January 1, 1996
Creator: Sarofim, A. F.
Object Type: Report
System: The UNT Digital Library
PLUG: A FORTRAN program for the analysis of PLUG flow reactors with gas-phase and surface chemistry (open access)

PLUG: A FORTRAN program for the analysis of PLUG flow reactors with gas-phase and surface chemistry

This manual describes the structure and usage of the computer program PLUG, which simulates the behavior of plug flow chemical reactors. More specifically, the code is designed to model the non-dispersive one-dimensional flow of a chemically reacting ideal gas mixture in a conduit of essentially arbitrary geometry. The code makes use of the CHEMKIN and SURFACE CHEMKIN software packages to handle gas-phase and heterogeneous kinetics as well as thermodynamic properties. In addition, the standard implicit code DASSL is used to solve the set of differential/algebraic equations describing the reactor. These equations are briefly discussed here, after which the procedures for running PLUG are described in some detail. Input and output files for a sample problem involving chemical vapor deposition are given.
Date: January 1, 1996
Creator: Larson, R. S.
Object Type: Report
System: The UNT Digital Library
Role of the resid solvent in catalytic coprocessing with finely divided catalysts. Final report (open access)

Role of the resid solvent in catalytic coprocessing with finely divided catalysts. Final report

The role of the resid in coprocessing coal with petroleum resid has been investigated using model systems. The primary question being investigated is whether resid is participating in reactions with coal or if the resid is acting simply as a diluent. Since hydrogen transfer is an important mechanism by which solvent interacts with coal, hydrogen transfer between naphthenes, saturated alicyclic molecules, that represent resid and aromatic molecules that represent coal were examined in reactions with a high pressure H{sub 2} atmosphere that is typical of actual coprocessing. The model naphthene, perhydropyrene, was chosen as the donor species and the models, anthracene, phenanthrene, and benzophenone, were chosen as the acceptor species. Coprocessing reactions of coal with petroleum resid were performed to evaluate the effect of the chemistry of both constituents on coal conversion and the upgrading of the heavy resid. Three heavy resids, Maya, FHC-623 and Manji were used as the whole resid and as fractions that has been separates into hexane solubles and saturate fractions.
Date: January 1, 1996
Creator: Curtis, C.W.
Object Type: Report
System: The UNT Digital Library