Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. …

Inversion of head wave arrival times for three-dimensional (3D) planar structure is formulated as a constrained parameter optimization problem, and solved via linear programming techniques. The earth model is characterized by a set of homogeneous and isotropic layers bounded by plane, dipping interfaces. Each interface may possess arbitrary strike and dip. Predicted data consists of traveltimes of critically refracted waves formed on the plane interfaces of the model. The nonlinear inversion procedure is iterative; an initial estimate of the earth model is refined until an acceptable match is obtained between observed and predicted data. Inclusion of a priori constraint information, in the form of inequality relations satisfied by the model parameters, assists the algorithm in converging toward a realistic solution. Although the 3D earth model adopted for the inversion procedure is simple, the algorithm is quite useful in two particular contexts: (i) it can provide an initial model estimate suitable for subsequent improvement by more general techniques (i.e., traveltime tomography), and (ii) it is an effective analysis tool for investigating the power of areal recording geometries for detecting and resolving 3D dipping planar structure.

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.

None

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Michael Raiden, 8, David Raiden, Melissa Raiden, 14, Annette Raiden, 38, and Lezlie Raiden, 11.

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Michael Raiden, 8, David Raiden, Melissa Raiden, 14, Annette Raiden, 38, and Lezlie Raiden, 11.

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Melissa Raiden, 14, Michael Raiden, 8, Annette Raiden, 38, and Lezlie Raiden, 11.

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Michael Raiden, 8, David Raiden, Melissa Raiden, 14, Annette Raiden, 38, and Lezlie Raiden, 11.

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Michael Raiden, 8, David Raiden, Melissa Raiden, 14, Annette Raiden, 38, and Lezlie Raiden, 11.

Photograph of the Annette Raiden Family, survivors of the May 3, 1999, Moore Tornado. R to L: Michael Raiden, 8, Lezlie Raiden, 11, Melissa Raiden, 14, Annette Raiden, 38, and David Raiden.

This quarterly report covers the following topics: (1) Properties of and Manufacturing Methods for NIF Laser Glasses (J. H. Campbell)--The NIF amplifiers require 3380 Nd-doped laser glass slabs; continuous glass melting methods will be used for the first time to manufacture these slabs. The properties of the laser glasses are summarized and the novel continuous melting method is described. (2) Diffractive Optics for the NIF (J. A. Britten)--We have fabricated demonstration diffractive optics according to the NIF baseline design at full scale, via wet-chemical etching of patterns into fused silica. We have examined the effects of dip-coated sol-gel antireflection coatings on the performance of these optics, and have concluded that diffractive optics should remain uncoated to minimize laser-induced damage to downstream optics and to maximize environmental stability. We have also demonstrated the feasibility of combining all diffractive structures required by NIF, which vary over orders of magnitude in lateral and vertical scales, onto a single surface. (3) Producing KDP and DKDP Crystals for the NIF Laser (A. K. Burnham)--Rapid-growth KDP has overcome most of the hurdles for production of boules for NIF switch crystals and doublers, but some improvements in process reliability at the tripler's 3{omega} damage threshold are needed. …

The atomic vapor laser isotope separation process uses high-average power lasers that have the commercial potential to enrich uranium for the electric power utilities. The transport of the laser beam through the laser system to the separation chambers requires high performance optical components, most of which have either fused silica or Zerodur as the substrate material. One of the requirements of the optical components is to preserve the wavefront quality of the laser beam that propagate over long distances. Full aperture tests with the high power process lasers and finite element analysis (FEA) have been performed on the transport optics. The wavefront distortions of the various sections of the transport path were measured with diagnostic Hartmann sensor packages. The FEA results were derived from an in-house thermal-structural-optical code which is linked to the commercially available CodeV program. In comparing the measured and predicted results, the bulk absorptance of fused silica was estimated to about 50 ppm/cm in the visible wavelength regime. Wavefront distortions are reported on optics made from fused silica and Zerodur substrate materials.

Your Genes, Your Choices provides accurate information about the ethical, legal, and social implications of the Human Genome Project and genetic research in an easy-to-read style and format. Each chapter in the book begins with a brief vignette, which introduces an issue within a human story, and raises a question for the reader to think about as the basic science and information are presented in the rest of the chapter.

None

A new methodology for neural learning is presented, whereby only a single iteration is required to train a feed-forward network with near-optimal results. To this aim, a virtual input layer is added to the multi-layer architecture. The virtual input layer is connected to the nominal input layer by a specird nonlinear transfer function, and to the fwst hidden layer by regular (linear) synapses. A sequence of alternating direction singular vrdue decompositions is then used to determine precisely the inter-layer synaptic weights. This algorithm exploits the known separability of the linear (inter-layer propagation) and nonlinear (neuron activation) aspects of information &ansfer within a neural network.

Through the National Governors' Association (NGA) project ''Critical Issues Related to Radioactive Waste and Materials Disposition Involving DOE Facilities'' NGA brings together Governors' policy advisors, state regulators, and DOE officials to examine critical issues related to the cleanup and operation of DOE nuclear weapons and research facilities. Topics explored through this project include: (1) Decisions involving disposal of mixed, low-level, and transuranic (TRU) waste and disposition of nuclear materials; (2) Decisions involving DOE budget requests and their effect on environmental cleanup and compliance at DOE facilities; (3) Strategies to treat mixed, low-level, and transuranic (TRU) waste and their effect on individual sites in the complex; (4) Changes to the FFCA site treatment plans as a result of proposals in the Department's Accelerating Cleanup: Paths to Closure plan and contractor integration analysis; (5) Interstate waste and materials shipments; and (6) Reforms to existing RCRA and CERCLA regulations/guidance to address regulatory overlap and risks posed by DOE wastes. The overarching theme of this project is to help the Department improve coordination of its major program decisions with Governors' offices and state regulators and to ensure such decisions reflect input from these key state officials and stakeholders. This report summarizes activities conducted during …

Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size and type on water nuclear spin relaxation, T2, were measured and modeled.

Changes in pollutant profiles observed in contaminated soils have been attributed to biological activity when in actuality abiotic processes caused pollutant removal.1 This sometimes casual implication of biodegradation is not acceptable, but understandable, because factors which cause the disappearance of pollutants are not always easy to identify. Several pollutant removal or transformation pathways are possible with most pollutants found in soil and these processes may or may not operate independently. Careful evaluation of bioremediation necessitates that all transformation and removal pathways are anticipated so that the pathways are either controlled or monitored but in practice this is generally not possible. The diminution in pollutant oxidation might track with several candidate loss mechanisms and when this occurs the real cause becomes problematic to pin point. Many factors disguise or prevent the effectual tracking of bioremediation processes among which are three general types of problems: (1) The estimate that only about 0.1% or less of the microorganisms living in soils are culturable leads to the conclusion that the possibility for unknown organisms participating in a biodegradation pathway is high. How should these imperceptible microorganisms be tracked? (2) The diversity of the microcosm is large, yet several different genera have been shown to …

Changes in pollutant profiles observed in contaminated soils have been attributed to biological activity when in actuality abiotic processes caused pollutant removal.1 This sometimes casual implication of biodegradation is not acceptable, but understandable, because factors which cause the disappearance of pollutants are not always easy to identify. Several pollutant removal or transformation pathways are possible with most pollutants found in soil and these processes may or may not operate independently. Careful evaluation of bioremediation necessitates that all transformation and removal pathways are anticipated so that the pathways are either controlled or monitored but in practice this is generally not possible. The diminution in pollutant oxidation might track with several candidate loss mechanisms and when this occurs the real cause becomes problematic to pin point. Many factors disguise or prevent the effectual tracking of bioremediation processes among which are three general types of problems: (1) The estimate that only about 0.1% or less of the microorganisms living in soils are culturable leads to the conclusion that the possibility for unknown organisms participating in a biodegradation pathway is high. How should these imperceptible microorganisms be tracked? (2) The diversity of the microcosm is large, yet several different genera have been shown to …

Carbon tetrachloride has been used extensively within the DOE nuclear weapons facilities. Rocky Flats was formerly the largest volume consumer of CCl4 in the United States using 5000 gallons in 1977 alone (Ripple, 1992). At the Hanford site, several hundred thousand gallons of CCl4 were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl4 in groundwater at highly contaminated sites at the Hanford facility have exceeded 8 the drinking water standard of 5 ppb by several orders of magnitude (Illman, 1993). High levels of CCl4 at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl4 cleanup required at these sites and associated costs are driven by current human health risk estimates, which assume that CCl4 is a genotoxic carcinogen. The overall purpose of these studies was to improve the scientific basis for assessing the health risk associated with human exposure to CCl4. Specific research objectives of this project were to: (1) compare the rates of CCl4 metabolism by rats, mice and hamsters in vivo and extrapolate those rates to man based on parallel studies on the metabolism of CCl4 by rat, mouse, hamster and human …

The spin-flop transition in the antiferromagnetic layered manganite La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} was studied using magnetization measurements and a high-resolution magneto-optical imaging technique. We report the direct observation of the formation of ferromagnetic domains appearing at the first order spin-flop transition. The magnetization process proceeds through nucleation of polarized domains at crystal defect sites and not through the expansion of polarized domains due to domain wall motion. A small magnetic hysteresis is caused by the difference between the mechanisms of nucleation and annihilation of domains in the mixed state. These results establish a direct link between the magnetic structure on the atomic scale as seen in neutron scattering and the macroscopic properties of the sample as seen in magnetization and conductivity measurements.

Weekly newspaper from Harper, Texas that includes local, state, and national news along with advertising.

None

During the tenure of this grant we focused our efforts on the treatment of (i) the behavior of the negative hydrogen ion, H{sup {minus}}, in a strong laser field (whose intensity extends well into the nonperturbative regime), and (ii) two-electron escape from a helium atom, He, by synchrotrons light. The calculations for H{sup {minus}} were done using perimetric coordinates u, v, and w, which are linear combinations of the three interparticle distances, together with the three Euler angles. The algebra involved in the implementation of the perimetric coordinate system can be quite formidable. However, we formulated [1] a general and tractable decomposition of the two-electron wavefunction which greatly facilitated the algebra. A complex Sturmian-type basis set, in these coordinates, was employed. One of the main advantages of the perimetric coordinates is that the matrices representing the system's Hamiltonian and its interaction with the radiation field are sparse, so that storage requirements and the number of operations are minimized. The correlation between the electrons is fully incorporated. Indeed, perimetric coordinates are ideally suited to situations where the correlation is strong; each of the planes u = 0, v = 0, ancl w = 0 has the special significance that the electrons …