During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast …

This study sought to determine and understand the major processes governing the abundance, distribution, composition and eventual fate of zooplankton on the southeastern shelf of the US in relation to water circulation. Over much of the shelf circulation is dominated by the Gulf Stream and/or atmospheric forcing. Most of our studies concentrated on processes on the middle and outer shelf. On the latter, pronounced biological production occurs year-round at frequent intervals and is due to Gulf Stream eddies which move by at an average frequency of one every week. These eddies are rich in nutrients which, when upwelled into the euphoric zone, lead to pronounced primary production which then triggers zooplankton production.

This study sought to determine and understand the major processes governing the abundance, distribution, composition and eventual fate of zooplankton on the southeastern shelf of the US in relation to water circulation. Over much of the shelf circulation is dominated by the Gulf Stream and/or atmospheric forcing. Most of our studies concentrated on processes on the middle and outer shelf. On the latter, pronounced biological production occurs year-round at frequent intervals and is due to Gulf Stream eddies which move by at an average frequency of one every week. These eddies are rich in nutrients which, when upwelled into the euphoric zone, lead to pronounced primary production which then triggers zooplankton production.

Results (solid-1600K, open-2000K surface temperature) from Fig.3 show that oxygen and nitrogen distributions are almost same although there is a little particle shrinkage (r[sub o]=0.009cm). C0[sub 2]/CO ratio drop significantly as the temperature increases, which is opposite to experimental results reported earlier. The cause of this behavior is mainly due to the lack of gas phase CO oxidation. Therefore, C0[sub 2]/CO ratio are directly related to C0[sub 2] and CO production of the heterogeneous reaction, which generates less C0[sub 2] as the temperature goes up. To get CO oxidation in the gas phase boundary layer, we may need to incorporate more elementary reactions. But the computation time currently used for one ignition-extinction calculation is about 2 Cray CPU hours, which is very long, and will be longer if we incorporate full reaction kinetics. Actually we don't need temperature and mass fraction distribution through the whole time span, there's a need to develop a gas phase model which calculates distributions for only one surface temperature. A model incorporating full reaction set is under development using the time dependent results of SCOM as an initial guess.

Results (solid-1600K, open-2000K surface temperature) from Fig.3 show that oxygen and nitrogen distributions are almost same although there is a little particle shrinkage (r{sub o}=0.009cm). C0{sub 2}/CO ratio drop significantly as the temperature increases, which is opposite to experimental results reported earlier. The cause of this behavior is mainly due to the lack of gas phase CO oxidation. Therefore, C0{sub 2}/CO ratio are directly related to C0{sub 2} and CO production of the heterogeneous reaction, which generates less C0{sub 2} as the temperature goes up. To get CO oxidation in the gas phase boundary layer, we may need to incorporate more elementary reactions. But the computation time currently used for one ignition-extinction calculation is about 2 Cray CPU hours, which is very long, and will be longer if we incorporate full reaction kinetics. Actually we don`t need temperature and mass fraction distribution through the whole time span, there`s a need to develop a gas phase model which calculates distributions for only one surface temperature. A model incorporating full reaction set is under development using the time dependent results of SCOM as an initial guess.

During design reviews of the Recycle Colection Tank (RCT) at the Savannah River Site it was determined that in all cases the RCT scrub solution could not be routed to the RCT. During transfers to the tank farm (estimated ten hour cycle), the ammonia evolved from the RCT is scrubbed by the RCT scrubber and the ammonia scrub water must be returned to the SMECT. The result of this is an increased steady state concentration of ammonium in the SMECT water used for the ammonia scrubbers. The maximum ammonium concentration is necessary for the sizing of the ammonia scrubbers for the Sludge Receipt and Adjustment Tank (SRAT),Slurry Mix Evaporator (SME), and RCT.

During design reviews of the Recycle Colection Tank (RCT) at the Savannah River Site it was determined that in all cases the RCT scrub solution could not be routed to the RCT. During transfers to the tank farm (estimated ten hour cycle), the ammonia evolved from the RCT is scrubbed by the RCT scrubber and the ammonia scrub water must be returned to the SMECT. The result of this is an increased steady state concentration of ammonium in the SMECT water used for the ammonia scrubbers. The maximum ammonium concentration is necessary for the sizing of the ammonia scrubbers for the Sludge Receipt and Adjustment Tank (SRAT),Slurry Mix Evaporator (SME), and RCT.

The approach to laser isotope separation taken in this study is based on isotopically selective, two-step, laser photodissociation of small molecules. A primary goal of this study is the measurement of fundamental molecular processes which control the two-step, photodissociative isotope enrichment process. This objective has led to experimental measurements of uv photodissociation cross sections for vibrationally excited states of several small molecules, including the first cross section reported for any neutral molecule in a specific, excited vibrational state. A second goal of this study has been the laboratory demonstration of isotope enrichment for isotopes of practical interest and for processes with a potential for larger scale production. Where possible, efforts have focussed on the separation of middle isotopes, such as {sup 17}O and {sup 33}S, which are expensive and difficult to separate using other techniques. Considerable success has been achieved in demonstrating the enrichment of isotopes of bromine, carbon, oxygen and a third goal of this study has been the application of computer modeling to the two-step enrichment process. Experimental measurements define as many as possible of the critical photophysical and chemical parameters required by an ab initio computer model of the enrichment process. Progress toward these goals has been …

The approach to laser isotope separation taken in this study is based on isotopically selective, two-step, laser photodissociation of small molecules. A primary goal of this study is the measurement of fundamental molecular processes which control the two-step, photodissociative isotope enrichment process. This objective has led to experimental measurements of uv photodissociation cross sections for vibrationally excited states of several small molecules, including the first cross section reported for any neutral molecule in a specific, excited vibrational state. A second goal of this study has been the laboratory demonstration of isotope enrichment for isotopes of practical interest and for processes with a potential for larger scale production. Where possible, efforts have focussed on the separation of middle isotopes, such as {sup 17}O and {sup 33}S, which are expensive and difficult to separate using other techniques. Considerable success has been achieved in demonstrating the enrichment of isotopes of bromine, carbon, oxygen and a third goal of this study has been the application of computer modeling to the two-step enrichment process. Experimental measurements define as many as possible of the critical photophysical and chemical parameters required by an ab initio computer model of the enrichment process. Progress toward these goals has been …

A mathematical model for the formation rate of ammonium nitrate in the off-gas line of the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mixed Evaporator (SME) in DWPF has been developed. The formation rate of ammonium nitrate in the off-gas line depends on pH, temperature, volume and total concentration of ammonia and ammonium ion. Based on a typical SRAT and SME cycle in DWPF, this model predicts the SRAT contributes about 50 lbs of ammonium nitrate while SME contributes about 60 lbs of ammonium nitrate to the off-gas line.

A mathematical model for the formation rate of ammonium nitrate in the off-gas line of the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mixed Evaporator (SME) in DWPF has been developed. The formation rate of ammonium nitrate in the off-gas line depends on pH, temperature, volume and total concentration of ammonia and ammonium ion. Based on a typical SRAT and SME cycle in DWPF, this model predicts the SRAT contributes about 50 lbs of ammonium nitrate while SME contributes about 60 lbs of ammonium nitrate to the off-gas line.

An in-tank ion exchange column, described here, has been constructed to operate in the waste tanks at the Savannah River Technology Center (SRTC). The purpose of the column is to remove dissolved mercury from laboratory wastes and capture them on Duolite{trademark} GT-73 resin. This paper summarizes the results of operation of such a column on two batches of waste in one high activity tank and on one batch of waste in a low activity tank for the purpose of removing mercury from the liquid wastes. Sufficient mercury decontamination was demonstrated with the in-tank resin removal system, after twenty four hours of operation in each tank, to render the waste nonhazardous and enable shipment to the F-Area evaporator.

An in-tank ion exchange column, described here, has been constructed to operate in the waste tanks at the Savannah River Technology Center (SRTC). The purpose of the column is to remove dissolved mercury from laboratory wastes and capture them on Duolite[trademark] GT-73 resin. This paper summarizes the results of operation of such a column on two batches of waste in one high activity tank and on one batch of waste in a low activity tank for the purpose of removing mercury from the liquid wastes. Sufficient mercury decontamination was demonstrated with the in-tank resin removal system, after twenty four hours of operation in each tank, to render the waste nonhazardous and enable shipment to the F-Area evaporator.

This quarterly report discusses the technical progress of a US Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) Project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from a coal-fired boiler. The project is being conducted at Gulf Power Company's Plant Lansing Smith Unit 2 located near Panama City, Florida. The primary objective of this demonstration is to determine the long-term effects of commercially available tangentially-fired low NO[sub x] combustion technologies on NO[sub x] emissions and boiler performance. A target of achieving fifty percent NO[sub x] reduction using combustion modifications has been established for the project. The stepwise approach that is being used to evaluate the NO[sub x] control technologies requires three plant outages to successively install the test instrumentation and the different levels of the low NO[sub x] concentric firing system (LNCFS). Following each outage, a series of four groups of tests are performed. These are (1) diagnostic, (2) performance, (3) long-term, and (4) verification. These tests are used to quantify the NO[sub x] reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. This technical progress report presents the …

This quarterly report discusses the technical progress of a US Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) Project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The project is being conducted at Gulf Power Company`s Plant Lansing Smith Unit 2 located near Panama City, Florida. The primary objective of this demonstration is to determine the long-term effects of commercially available tangentially-fired low NO{sub x} combustion technologies on NO{sub x} emissions and boiler performance. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The stepwise approach that is being used to evaluate the NO{sub x} control technologies requires three plant outages to successively install the test instrumentation and the different levels of the low NO{sub x} concentric firing system (LNCFS). Following each outage, a series of four groups of tests are performed. These are (1) diagnostic, (2) performance, (3) long-term, and (4) verification. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. This technical progress report presents the …

Progress during the past year of research under Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' has been significant. As was described in our previous progress report, the startup phase of this research was severely frustrated by delays in the US WOCE Hydrographic Program (WHP), which in turn were caused by delays in the mid-life refit of the R/V Knorr. As a result the high latitude southeastern Pacific work (WHP lines P19S and P16S) originally scheduled for the 1990 austral summer has still not been carried out. As a substitute, the smaller R/V Thomas Washington was pressed into service during mid-1991 to carry out lower-latitude portions of the WHP P16 and P17 lines - the TUNES Expedition. Because this ship is much smaller than the R/V Knorr, she could not carry a full complement of WHP programs and seagoing personnel and was restricted by her size and the time of year to lower-latitude work. Our original proposal for carbon dioxide measurements was designed to divide the work between legs in which we participated as part of the WHP dissolved CFC program (under separate NSF funding) and legs in which we entrusted the operation of our system to other …

Progress during the past year of research under ``Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE`` has been significant. As was described in our previous progress report, the startup phase of this research was severely frustrated by delays in the US WOCE Hydrographic Program (WHP), which in turn were caused by delays in the mid-life refit of the R/V Knorr. As a result the high latitude southeastern Pacific work (WHP lines P19S and P16S) originally scheduled for the 1990 austral summer has still not been carried out. As a substitute, the smaller R/V Thomas Washington was pressed into service during mid-1991 to carry out lower-latitude portions of the WHP P16 and P17 lines - the TUNES Expedition. Because this ship is much smaller than the R/V Knorr, she could not carry a full complement of WHP programs and seagoing personnel and was restricted by her size and the time of year to lower-latitude work. Our original proposal for carbon dioxide measurements was designed to divide the work between legs in which we participated as part of the WHP dissolved CFC program (under separate NSF funding) and legs in which we entrusted the operation of our system to other …

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO`s is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today`s cost. A suggested resource verification plan is presented.

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO's is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today's cost. A suggested resource verification plan is presented.

Three experiments were conducted within a semiarid shrubland to test the role of nitrogen availability as a control mechanism in secondary succession. Secondary succession patterns were documented for seven years and effects of increased and decreased N availability levels, fumigation, and competition by early-seral species were tested. Differential responses by seral species were determined and related to successional patterns. Nitrogen availability was found to be a primary mechanism controlling the rate of succession. Relative growth rate was an important factor determining which species initially dominated and N availability became the primary control factor by the third year. As N availability increased, the rate of succession decreased. Conversely, as N availability was decreased, the rate of succession increased. The abundance of annuals was increased and abundance of perennials decreased by increased N availability. Tissue N concentration was related to lifeform and seral position, and these relationships were important in the transition from early- to mid-seral stages. Decomposer subsystem dynamics were correlated with seral community dynamics. The effect of fumigation was minimized by initially planting with late-seral species. A conceptual model of secondary succession is presented based on N availability, relative growth rate, lifeform, and decomposition dynamics.

Three experiments were conducted within a semiarid shrubland to test the role of nitrogen availability as a control mechanism in secondary succession. Secondary succession patterns were documented for seven years and effects of increased and decreased N availability levels, fumigation, and competition by early-seral species were tested. Differential responses by seral species were determined and related to successional patterns. Nitrogen availability was found to be a primary mechanism controlling the rate of succession. Relative growth rate was an important factor determining which species initially dominated and N availability became the primary control factor by the third year. As N availability increased, the rate of succession decreased. Conversely, as N availability was decreased, the rate of succession increased. The abundance of annuals was increased and abundance of perennials decreased by increased N availability. Tissue N concentration was related to lifeform and seral position, and these relationships were important in the transition from early- to mid-seral stages. Decomposer subsystem dynamics were correlated with seral community dynamics. The effect of fumigation was minimized by initially planting with late-seral species. A conceptual model of secondary succession is presented based on N availability, relative growth rate, lifeform, and decomposition dynamics.

Our objectives during this quarter was to complete studies on the kinetics of methanol synthesis reaction in the slurry reactor with long periods of on stream studies, start experimentation in the trickle bed reactor assembly, investigate simulation studies using the piston-exchange (PE) and piston-dispersion-exchange (PDE) models, and introduce water gas shift reaction as the second reaction in our simulation studies.

Our objectives during this quarter was to complete studies on the kinetics of methanol synthesis reaction in the slurry reactor with long periods of on stream studies, start experimentation in the trickle bed reactor assembly, investigate simulation studies using the piston-exchange (PE) and piston-dispersion-exchange (PDE) models, and introduce water gas shift reaction as the second reaction in our simulation studies.

While other programs check for bad passwords after the fact, it in important to have good passwords at all times, not just after the latest Crack run. To this end we have modified Larry Wall's Perl password program and added, among other features, the ability to check a sorted list of all the bad passwords'' that Crack will generate, given all the dictionaries that we could get our hands on (107 MB of unique words, so far). The combination of improvements has turned publicly available code into a powerful tool that can aid sites in the maintenance of local security.