The influence of naturally-occurring organic acids on model estimates of lakewater acidification using the model of acidification of groundwater in catchments (MAGIC) (open access)

The influence of naturally-occurring organic acids on model estimates of lakewater acidification using the model of acidification of groundwater in catchments (MAGIC)

A project for the US Department of Energy, entitled Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and Testing of the Revised Model UsingIndependent Data Sources'' was initiated by E S Environmental Chemistry, Inc. in March, 1992. Major components of the project include: improving the MAGIC model by incorporating a rigorous organic acid representation, based on empirical data and geochemical considerations, and testing the revised model using data from paleolimnological hindcasts of preindustrial chemistry for 33 Adirondack Mountain lakes, and the results of whole-catchment artificial acidification projects in Maine and Norway. The ongoing research in this project involves development of an organic acid representation to be incorporated into the MAGIC modeland testing of the improved model using three independent data sources. The research during Year 1 has included conducting two workshops to agree on an approach for the organic acid modeling, developing the organic subroutine and incorporating it into MAGIC (Task 1), conducing MAGIC hindcasts for Adirondack lakes and comparing the results with paleolimnological reconstructions (Task 2), and conducting site visits to the manipulation project sites in Maine and Norway. The purpose of this report is to provide a summary of the work …
Date: March 5, 1993
Creator: Sullivan, T.J.; Eilers, J.M. (E and S Environmental Chemistry, Inc., Corvallis, OR (United States)); Cosby, B.J. (Virginia Univ., Charlottesville, VA (United States). Dept. of Environmental Sciences); Driscoll, C.T. (Syracuse Univ., NY (United States). Dept. of Civil Engineering); Hemond, H.F. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Civil Engineering) & Charles, D.F.
System: The UNT Digital Library
Shemya Air Force Base, Alaska No Further Action Decision document for Hg-1 (open access)

Shemya Air Force Base, Alaska No Further Action Decision document for Hg-1

This document is being prepared to document that a No Further Action Decision (NFAD) document is appropriate for the Hg-1 site at Shemya Air Force Base (AFB), Alaska, under the Air Force Installation Restoration Program (IRP). The IRP is a Department of Defense (DOD) program established to identify and remediate hazardous waste problems on DOD property that result from past practices. The Alaska Department of Environmental Conservation (ADEC) draft document [open quotes]No Further Action Criteria for DOD Military/FUD Sites[close quotes] has been used as a guide in preparing this document. Air Force personnel have stated that the Hg-1 site may have been used to store mercury and PCB-contaminated material. The site was added to the IRP in 1987, and later that year a field investigation was conducted at the site. Soil samples were collected and analyzed for mercury, EP toxicity, polychlorinated biphenyls (PCBs), and dioxin. All concentrations of contaminants found in Area Hg-1 are below regulatory action levels for PCBs (40 CFR 761) and mercury (55 FR 30798) or below detection levels for dioxin/furans. Therefore, leaving these soils in place is acceptable.
Date: March 5, 1993
Creator: unknown
System: The UNT Digital Library
Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies (open access)

Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies

The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.
Date: April 5, 1993
Creator: Webster, S. S. J.
System: The UNT Digital Library
Short-Term Energy Outlook: Quarterly projections. Fourth quarter 1993 (open access)

Short-Term Energy Outlook: Quarterly projections. Fourth quarter 1993

The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the fourth quarter of 1993 through the fourth quarter of 1994. Values for the third quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications.
Date: November 5, 1993
Creator: unknown
System: The UNT Digital Library
Longitudinal information and radiation damage in EM calorimetry (open access)

Longitudinal information and radiation damage in EM calorimetry

The SCC radiation field is higher than that encountered by previous hadron collider detectors. In particular, the electromagnetic (EM) calorimeter compartment sees the highest radiation dose. Since an EM calorimeter also makes the most precise energy measurement, special care must be lavished on this part of a calorimeter. Previous studies have concentrated on Monte Carlo examinations of 2 longitudinal compartments within the EM which can alleviate radiation damage. Recently, it was realized that a ``shower maximum`` detector, such as exists in CDF, also contains information of the conversion point of an electromagnetic shower. As such, it can potentially be used in a fashion analogous to the longitudinal compartments, although it is not designed to be optimized for this role.
Date: February 5, 1993
Creator: Green, D.
System: The UNT Digital Library
Monolithic Solid Oxide Fuel Cell Technology Advancement for Coal-Based Power Generation. Quarterly Technical Progress Report, October--December 1992 (open access)

Monolithic Solid Oxide Fuel Cell Technology Advancement for Coal-Based Power Generation. Quarterly Technical Progress Report, October--December 1992

The program focuses on materials research and development, fabrication process development, cell/stack performance testing and characterization, cost and system analysis, and quality development.
Date: February 5, 1993
Creator: unknown
System: The UNT Digital Library
Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies. Final report (open access)

Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies. Final report

The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.
Date: April 5, 1993
Creator: Webster, S. S. J.
System: The UNT Digital Library
The influence of naturally-occurring organic acids on model estimates of lakewater acidification using the model of acidification of groundwater in catchments (MAGIC). Summary of research conducted during year 1 (open access)

The influence of naturally-occurring organic acids on model estimates of lakewater acidification using the model of acidification of groundwater in catchments (MAGIC). Summary of research conducted during year 1

A project for the US Department of Energy, entitled ``Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and Testing of the Revised Model UsingIndependent Data Sources`` was initiated by E&S Environmental Chemistry, Inc. in March, 1992. Major components of the project include: improving the MAGIC model by incorporating a rigorous organic acid representation, based on empirical data and geochemical considerations, and testing the revised model using data from paleolimnological hindcasts of preindustrial chemistry for 33 Adirondack Mountain lakes, and the results of whole-catchment artificial acidification projects in Maine and Norway. The ongoing research in this project involves development of an organic acid representation to be incorporated into the MAGIC modeland testing of the improved model using three independent data sources. The research during Year 1 has included conducting two workshops to agree on an approach for the organic acid modeling, developing the organic subroutine and incorporating it into MAGIC (Task 1), conducing MAGIC hindcasts for Adirondack lakes and comparing the results with paleolimnological reconstructions (Task 2), and conducting site visits to the manipulation project sites in Maine and Norway. The purpose of this report is to provide a summary of the work that …
Date: March 5, 1993
Creator: Sullivan, T. J.; Eilers, J. M.; Cosby, B. J.; Driscoll, C. T.; Hemond, H. F.; Charles, D. F. et al.
System: The UNT Digital Library
The use of post detonation analysis of stable isotope ratios to determine the type and production process of the explosive involved (open access)

The use of post detonation analysis of stable isotope ratios to determine the type and production process of the explosive involved

The detonation of a series of explosives was performed in a controlled manner to collect the resulting, solid residue or {open_quotes}soot.{close_quotes} This residue was examined to determine the ratios of the stable carbon, hydrogen, and nitrogen isotopes. The goal of the experiment was to determine if these ratios could be used to indicate, from the post detonation residues, the type and origin of the detonated explosive. The ratios of the stated stable isotopes in the undetonated explosive were also determined. Despite some reservations in the quality of the data resulting from contamination by nonexplosive components, certain trends can be discerned. (1) Carbon isotopes allow aromatic explosives to be distinguished from nonaromatic explosives. This trend seems to carry through the detonation so that the distinction might be made after the fact. (2) The amination process for TATB can be detected through the hydrogen and, to some extent, the nitrogen isotope ratios. Unfortunately, the data are not sufficiently good to determine if this differential carries through the detonation. (3) The relative magnitude and sign of the nitrogen isotope ratio seems to carry through the detonation: some exchange with atmospheric nitrogen is probable. Even though this set of experiments must also be viewed …
Date: March 5, 1993
Creator: McGuire, R. R.; Velsko, C. A.; Lee, C. G. & Raber, E.
System: The UNT Digital Library
Ceramic films and interfaces: Chemical and mechanical properties. Final report (open access)

Ceramic films and interfaces: Chemical and mechanical properties. Final report

Results are reported in two areas: (1) understanding the mechanism of superplasticity in those that show unusual resistance to intergranular cavitation, and (2) understanding the growth of heteroepitaxial films of oxides by CVD (NiO, TiO{sub 2}).
Date: June 5, 1993
Creator: Raj, R.
System: The UNT Digital Library
Lot No. 2 of Frit 202 for DWPF cold runs (open access)

Lot No. 2 of Frit 202 for DWPF cold runs

In the DWPF (Defense Waste Processing Facility), glass forming chemicals will be added to the waste in the form of premelted glass frit. On an oxide weight basis, DWPF glass will consist of approximately 64 wt% glass frit, 8 wt% precipitate hydrolysis aqueous product, and 28 wt% sludge. The glass frit and the precipitate hydrolysis aqueous product together make up what is called the glass-former composition. Current plants are to control the composition of the frit through the procurement specifications and chemical analyses of representative lot samples. The following report was prepared at the end of 1992 and summarizes the evaluation of the second lot sample of DWPF Frit 202 from Cataphote Inc. The frit was received and evaluated for moisture, particle size distribution, organic-inorganic carbon and chemical composition. The moisture content was within specification. The particle size determination indicates that there was a fraction of a percent more coarse frit (+80 mesh) than the specified amount. The fine end of the distribution was within specification. A representative sample was submitted to Corning Engineering Laboratory Services for chemical analyses. The sample was split and two dissolutions prepared. Each dissolution was analyzed on two separate days. The results indicate that there …
Date: April 5, 1993
Creator: Schumacher, R. F.
System: The UNT Digital Library
Measurement of source tube radial position in cast EMC testbeam module (open access)

Measurement of source tube radial position in cast EMC testbeam module

Using a {sup 137}Cs source we have determined the position of two of the source tubes embedded in the Pb absorber in the cast EMC module used in the Fermilab test beam. Two scintillator tiles placed in the gaps on both sides of an absorber containing a source tube were readout into independent phototubes. The difference in scintillator response was measured in two towers at two different source tube layers. We find the source tube to be displaced towards the (radial) front of the EMC by about 1.6 mm in both measurements. Work is proceeding now to check other source tubes in other locations.
Date: May 5, 1993
Creator: Jankowski, D. J. & Stanek, R.
System: The UNT Digital Library
Shemya Air Force Base, Alaska No Further Action Decision document for Hg-1. Final report (open access)

Shemya Air Force Base, Alaska No Further Action Decision document for Hg-1. Final report

This document is being prepared to document that a No Further Action Decision (NFAD) document is appropriate for the Hg-1 site at Shemya Air Force Base (AFB), Alaska, under the Air Force Installation Restoration Program (IRP). The IRP is a Department of Defense (DOD) program established to identify and remediate hazardous waste problems on DOD property that result from past practices. The Alaska Department of Environmental Conservation (ADEC) draft document {open_quotes}No Further Action Criteria for DOD Military/FUD Sites{close_quotes} has been used as a guide in preparing this document. Air Force personnel have stated that the Hg-1 site may have been used to store mercury and PCB-contaminated material. The site was added to the IRP in 1987, and later that year a field investigation was conducted at the site. Soil samples were collected and analyzed for mercury, EP toxicity, polychlorinated biphenyls (PCBs), and dioxin. All concentrations of contaminants found in Area Hg-1 are below regulatory action levels for PCBs (40 CFR 761) and mercury (55 FR 30798) or below detection levels for dioxin/furans. Therefore, leaving these soils in place is acceptable.
Date: March 5, 1993
Creator: unknown
System: The UNT Digital Library
Biological Conversion of Synthesis Gas. Project Status Report, October 1, 1992--December 31, 1992 (open access)

Biological Conversion of Synthesis Gas. Project Status Report, October 1, 1992--December 31, 1992

Syngas is known to contain approximately 1 percent H{sub 2}S, along with CO{sub 2}, C0{sub 2}, H{sub 2} and CH{sub 4}. Similarly, the syngas may become contaminated with oxygen, particularly during reactor start-up and during maintenance. Previous studies with the water-gas shift bacterium Rhodospirillum rubrum have shown that the bacterium is tolerant of small quantities of oxygen, but the effects of oxygen on CO-consumption are unknown. Similarly, R. rubrum is known to be tolerant of H{sub 2}S, with high concentrations of H{sub 2}S negatively affecting CO-uptake. Batch experiments were thus carried out to determine the effects of H{sub 2}S and O{sub 2} on CO-uptake by R. rubrum. The results of these experiments were quantified by using Monod equations modified by adding terms for CO, H{sub 2}S and O{sub 2} inhibition. The techniques used in determining kinetic expressions previously shown for other gas-phase substrate bacterial systems including R. rubrum were utilized.
Date: January 5, 1993
Creator: Ackerson, M. D.; Clausen, E. C. & Gaddy, J. L.
System: The UNT Digital Library
Human Factors evaluation of LCS 254 and 255 (open access)

Human Factors evaluation of LCS 254 and 255

This report includes the results of the Human Factors evaluation of the local control stations (LCS) 254 and 255 performed by Savannah River Technology Center (SRTC) Human Factors. Recommendations are included in order that the panel designs will be upgraded to comply with human engineering design guidelines. Figures 1 and 2 are included as examples of recommended changes. Also, consideration was given to including the proposed engineering changes which are currently on-going for LCS 255. Appendix A identifies the human engineering requirements from NUREG-0700 which were used in the evaluation process, and the areas of the design which do not comply with the guidelines. Those areas of the panel design which fail to comply with the human engineering guidelines are label location, label content, location aids, panel layout, and control display integration. Each of these design deficiencies and proposed corrections are described in this report.
Date: May 5, 1993
Creator: Goffe, L. & Held, J. E.
System: The UNT Digital Library
Malignant melanoma slide review project: Patients from non-Kaiser hospitals in the San Francisco Bay Area. Final report (open access)

Malignant melanoma slide review project: Patients from non-Kaiser hospitals in the San Francisco Bay Area. Final report

This project was initiated, in response to concerns that the observed excess of malignant melanoma among employees of Lawrence Livermore National Laboratory (LLNL) might reflect the incidence of disease diagnostically different than that observed in the general population. LLNL sponsored a slide review project, inviting leading dermatopathology experts to independently evaluate pathology slides from LLNL employees diagnosed with melanoma and those from a matched sample of Bay Area melanoma patients who did not work at the LLNL. The study objectives were to: Identify all 1969--1984 newly diagnosed cases of malignant melanoma among LLNL employees resident in the San Francisco-Oakland Metropolitan Statistical Area, and diagnosed at facilities other than Kaiser Permanente; identify a comparison series of melanoma cases also diagnosed between 1969--1984 in non-Kaiser facilities, and matched as closely as possible to the LLNL case series by gender, race, age at diagnosis, year of diagnosis, and hospital of diagnosis; obtain pathology slides for the identified (LLNL) case and (non-LLNL) comparison patients for review by the LLNL-invited panel of dermatopathology experts; and to compare the pathologic characteristics of the case and comparison melanoma patients, as recorded by the dermatopathology panel.
Date: January 5, 1993
Creator: Reynolds, P.
System: The UNT Digital Library
Diffusion in phase space (open access)

Diffusion in phase space

In order to study diffusion in any region of phase space containing nested closed curves we choose action-angle variables, {gamma}, J. the action J labels each closed phase curve and is equal to its area divided by 2{pi}. We can introduce rectangular variables Q,P by the equations Q=(2J){sup 1/2}sin{gamma}, P=(2J){sup 1/2}cos{gamma}, where the angle variable {gamma} is measured clockwise from the P-axis. The phase curves are circles in the Q,P plane with radius (2J){sup 1/2}. We assume that the motion consists of a Hamiltonian motion along a curve of fixed J (in the original coordinate system and in the system Q,P) plus a diffusion and a damping which can change the value of J. Now consider a system of particles described by a density {rho}(J,t), so that the number of particles between the curves J and J+dJ is dN={rho}(J,t)dJ. These cN particles are distributed uniformly in the phase space between the curves J and J+dJ.
Date: April 5, 1993
Creator: Symon, K.
System: The UNT Digital Library
Methods for testing transport models. [Departments of Nuclear Engineering and Statistics, Univ. of Illinois at Urbana[endash]Champaign] (open access)

Methods for testing transport models. [Departments of Nuclear Engineering and Statistics, Univ. of Illinois at Urbana[endash]Champaign]

This report documents progress to date under a three-year contract for developing Methods for Testing Transport Models.'' The work described includes (1) choice of best methods for producing code emulators'' for analysis of very large global energy confinement databases, (2) recent applications of stratified regressions for treating individual measurement errors as well as calibration/modeling errors randomly distributed across various tokamaks, (3) Bayesian methods for utilizing prior information due to previous empirical and/or theoretical analyses, (4) extension of code emulator methodology to profile data, (5) application of nonlinear least squares estimators to simulation of profile data, (6) development of more sophisticated statistical methods for handling profile data, (7) acquisition of a much larger experimental database, and (8) extensive exploratory simulation work on a large variety of discharges using recently improved models for transport theories and boundary conditions. From all of this work, it has been possible to define a complete methodology for testing new sets of reference transport models against much larger multi-institutional databases.
Date: January 5, 1993
Creator: Singer, C. & Cox, D.
System: The UNT Digital Library
Biological Conversion of Synthesis Gas (open access)

Biological Conversion of Synthesis Gas

Syngas is known to contain approximately 1 percent H[sub 2]S, along with CO[sub 2], C0[sub 2], H[sub 2] and CH[sub 4]. Similarly, the syngas may become contaminated with oxygen, particularly during reactor start-up and during maintenance. Previous studies with the water-gas shift bacterium Rhodospirillum rubrum have shown that the bacterium is tolerant of small quantities of oxygen, but the effects of oxygen on CO-consumption are unknown. Similarly, R. rubrum is known to be tolerant of H[sub 2]S, with high concentrations of H[sub 2]S negatively affecting CO-uptake. Batch experiments were thus carried out to determine the effects of H[sub 2]S and O[sub 2] on CO-uptake by R. rubrum. The results of these experiments were quantified by using Monod equations modified by adding terms for CO, H[sub 2]S and O[sub 2] inhibition. The techniques used in determining kinetic expressions previously shown for other gas-phase substrate bacterial systems including R. rubrum were utilized.
Date: January 5, 1993
Creator: Ackerson, M. D.; Clausen, E. C. & Gaddy, J. L.
System: The UNT Digital Library
Longitudinal information and radiation damage in EM calorimetry (open access)

Longitudinal information and radiation damage in EM calorimetry

The SCC radiation field is higher than that encountered by previous hadron collider detectors. In particular, the electromagnetic (EM) calorimeter compartment sees the highest radiation dose. Since an EM calorimeter also makes the most precise energy measurement, special care must be lavished on this part of a calorimeter. Previous studies have concentrated on Monte Carlo examinations of 2 longitudinal compartments within the EM which can alleviate radiation damage. Recently, it was realized that a shower maximum'' detector, such as exists in CDF, also contains information of the conversion point of an electromagnetic shower. As such, it can potentially be used in a fashion analogous to the longitudinal compartments, although it is not designed to be optimized for this role.
Date: February 5, 1993
Creator: Green, D.
System: The UNT Digital Library
Anaerobic biprocessing of low rank coals. Final technical report, September 12, 1990--August 10, 1993 (open access)

Anaerobic biprocessing of low rank coals. Final technical report, September 12, 1990--August 10, 1993

Coal solubilization under aerobic conditions results in oxygenated coal product which, in turn, makes the coal poorer fuel than the starting material. A novel approach has been made in this project is to remove oxygen from coal by reductive decarboxylation. In Wyodak subbituminous coal the major oxygen functionality is carboxylic groups which exist predominantly as carboxylate anions strongly chelating metal cations like Ca{sup 2+} and forming strong macromolecular crosslinks which contribute in large measure to network polymer structure. Removal of the carboxylic groups at ambient temperature by anaerobic organisms would unravel the macromoleculer network, resulting in smaller coal macromolecules with increased H/C ratio which has better fuel value and better processing prospects. These studies described here sought to find biological methods to remove carboxylic functionalities from low rank coals under ambient conditions and to assess the properties of these modified coals towards coal liquefaction. Efforts were made to establish anaerobic microbial consortia having decarboxylating ability, decarboxylate coal with the adapted microbial consortia, isolate the organisms, and characterize the biotreated coal products. Production of CO{sup 2} was used as the primary indicator for possible coal decarboxylation.
Date: August 5, 1993
Creator: Jain, M. K. & Narayan, R.
System: The UNT Digital Library
Methods for testing transport models. Third year annual report (open access)

Methods for testing transport models. Third year annual report

This report documents progress to date under a three-year contract for developing ``Methods for Testing Transport Models.`` The work described includes (1) choice of best methods for producing ``code emulators`` for analysis of very large global energy confinement databases, (2) recent applications of stratified regressions for treating individual measurement errors as well as calibration/modeling errors randomly distributed across various tokamaks, (3) Bayesian methods for utilizing prior information due to previous empirical and/or theoretical analyses, (4) extension of code emulator methodology to profile data, (5) application of nonlinear least squares estimators to simulation of profile data, (6) development of more sophisticated statistical methods for handling profile data, (7) acquisition of a much larger experimental database, and (8) extensive exploratory simulation work on a large variety of discharges using recently improved models for transport theories and boundary conditions. From all of this work, it has been possible to define a complete methodology for testing new sets of reference transport models against much larger multi-institutional databases.
Date: January 5, 1993
Creator: Singer, C. & Cox, D.
System: The UNT Digital Library
Parameterization of Convective Clouds Mesoscale Convective Systems, and Convective-Generated Cirrus. Final Report, September 15, 1990--October 31, 1993 (open access)

Parameterization of Convective Clouds Mesoscale Convective Systems, and Convective-Generated Cirrus. Final Report, September 15, 1990--October 31, 1993

The overall goal of this research is to develop a scheme to parameterize diabatic heating, moisture/water substance, and momentum transports, and precipitation from mesoscale convective systems (MCSs) for use in general circulation models (GCMs). Our approach is to perform explicit cloud-resolving simulations of MCSs in the spirit of the GEWEX Cloud Systems Study (GCSS), by using the Regional Atmospheric Modeling System (RAMS) developed at Colorado State University (CSU). We then perform statistical analyses (conditional sampling, ensemble-averages, trajectory analyses) of simulated MCSs to assist in fabricating a parameterization scheme, calibrating coefficients, and provide independent tests of the efficacy of the parameterization scheme. A cloud-resolving simulation of ordinary cumulonimbi forced by sea breeze fronts has been completed. Analysis of this case and comparison with parameterized convection simulations has resulted in a number of refinements in the scheme. Three three-dimensional, cloud-resolving simulations of MCSs have been completed. Statistical analyses of model-output data are being performed to assist in developing a parameterization scheme of MCSs in general circulation models.
Date: November 5, 1993
Creator: Cotton, W. R.
System: The UNT Digital Library
Material characterization of the clay bonded silicon carbide candle filters and ash formations in the W-APF system after 500 hours of hot gas filtration at AEP. Appendix to Advanced Particle Filter: Technical progress report No. 11, January--March 1993 (open access)

Material characterization of the clay bonded silicon carbide candle filters and ash formations in the W-APF system after 500 hours of hot gas filtration at AEP. Appendix to Advanced Particle Filter: Technical progress report No. 11, January--March 1993

(1) After 500 hours of operation in the pressurized fluidized-bed combustion gas environment, the fibrous outer membrane along the clay bonded silicon carbide Schumacher Dia Schumalith candles remained intact. The fibrous outer membrane did not permit penetration of fines through the filter wall. (2) An approximate 10-15% loss of material strength occurred within the intact candle clay bonded silicon carbide matrix after 500 hours of exposure to the PFBC gas environment. A relatively uniform strength change resulted within the intact candles throughout the vessel (i.e., top to bottom plenums), as well as within the various cluster ring positions (i.e., outer versus inner ring candle filters). A somewhat higher loss of material strength, i.e., 25% was detected in fractured candle segments removed from the W-APF ash hopper. (3) Sulfur which is present in the pressurized fluidized-bed combustion gas system induced phase changes along the surface of the binder which coats the silicon carbide grains in the Schumacher Dia Schumalith candle filter matrix.
Date: April 5, 1993
Creator: Alvin, M. A.
System: The UNT Digital Library