Solvent extraction reagents containing the diphosphonic acid group exhibit an extraordinary affinity for tri-, tetra- and hexavalent actinides. Their use has been considered for actinide separation and pre-concentration procedures. Solvent extraction data obtained with P,P{prime}-di(2-ethylhexyl) methane-, ethane- and butanediphosphonic acids exhibit features that are difficult to explain without Knowledge of the aggregation state of the extractants. Information about the aggregation of the dialkyl-substituted diphosphonic acids in aromatic diluents has been obtained using the complementary techniques of vapor pressure osmometry (VPO), small angle neutron scattering (SANS), infrared spectroscopy and molecular mechanics. The results from these techniques provide an understanding of the aggregation behavior of these extractants that is fully compatible with the solvent extraction data. The most important results and their relevance to solvent extraction are reviewed in this paper.

When it was installed,the Advanced Photon Source (APS) control system network was at the state-of-the-art. Different aspects of the system have been reported at previous meetings [1,2]. As loads on the controls network have increased due to newer and faster workstations and front-end computers, we have found performance of the system declining and have implemented an upgraded network. There have been dramatic advances in networking hardware in the last several years. The upgraded APS controls network replaces the original FDDI backbone and shared Ethernet hubs with redundant gigabit uplinks and fully switched 10/100 Ethernet switches with backplane fabrics in excess of 20 Gbits/s (Gbps). The central collapsed backbone FDDI concentrator has been replaced with a Gigabit Ethernet switch with greater than 30 Gbps backplane fabric. Full redundancy of the system has been maintained. This paper will discuss this upgrade and include performance data and performance comparisons with the original network.

The goal of the project was to extend the theory of particle coarsening, which is well established for binary systems, to the case of multicomponent and multiphase alloys. The theoretical approach involved three stages: (1) a mean field description based on the Lifshitz-Slyozov-Wagner (LSW) [1,2] formulation (recently published in Acta Mater. [3]), (2) an analytical description of coarsening valid at small volume fractions where the Marqusee and Ross [4] model was employed and (3) a numerical simulation of three phase coarsening where the boundary integral method of Akaiwa and Voorhees [5] was implemented. The main result of the mean field analysis can be stated as follows. The growth rate of a particle from a particular phase in a multiphase system is precisely the same as that derived for a single phase, multicomponent system. Also, it was found that the scaled particle size distribution for each phase in the system has exactly the same form as that originally derived by LSW. Since it neglects particle interactions, the mean field theory is clearly unrealistic and as such the formulation of coarsening in low volume fraction multiphase systems was undertaken.

Sintering theory has been developed either as the application of complex diffusion mechanisms to a simple geometry or as the deformation and shrinkage of a continuum body. They present a model that can treat in detail both the evolution of microstructure and the sintering mechanisms, on the mesoscale, so that constitutive equations with detail microstructural information can be generated. The model is capable of simulating vacancy diffusion by grain boundary diffusion, annihilation of vacancies at grain boundaries resulting in densification, and coarsening of the microstructural features. In this paper, they review the stereological theory of sintering and its application to microstructural evolution and the diffusion mechanism, which lead to sintering. They then demonstrate how these stereological concepts and diffusion mechanisms were incorporated into a kinetic Monte Carlo model to simulate sintering. Finally, they discuss the limitations of this model.

Magnesium vanadates are potentially important catalytic materials for the conversion of alkanes to alkenes via oxidative dehydrogenation. However, little is known about the active sites at which the catalytic reactions take place. It may be possible to obtain a significant increase in the catalytic efficiency if the effects of certain material properties on the surface reactions could be quantified and optimized through the use of appropriate preparation techniques. Given that surface reactivity is often dependent upon surface structure and that the atomic level structure of the active sites in these catalysts is virtually unknown, we desire thin film samples consisting of a single magnesium vanadate phase and a well defined crystallographic orientation in order to reduce complexity and simplify the study of active sites. We report on the use of reactive RF sputter deposition to fabricate very highly oriented, stoichiometric Mg{sub 3}(VO{sub 4}){sub 2} thin films for use in these surface analysis studies. Deposition of samples onto amorphous substrates resulted in very poor crystallinity. However, deposition of Mg{sub 3}(VO{sub 4}){sub 2} onto well-oriented, lattice-matched thin film ''seed'' layers such as Ti(0001), Au(111), or Pt(111) resulted in very strong preferential (042) crystallographic orientation (pseudo-hexagonal oxygen planes parallel to the substrate). This …

The level of nuclear plant radiation exposure due to activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant coating. Laboratory pin-on-disc and rolling contact wear tests were used to evaluate the wear performance of several coatings. Based on the results of these tests, multilayer Cr-nitride coatings and ion nitriding are the most promising approaches.

Energy Efficiency Campaign for Residential Housing at the Fort Lewis Army Installation

State and local wastewater and drinking water capital needs were the most prominent budgetary issues. Senate and House authorizing and appropriating chairmen expressed concern over the requested 17% decrease in the State and Tribal Assistance Grants account from $3.41 billion in FY1999 to $2.84 billion in FY2000. The conference agreement on H.R. 2684 provides a total of $3.47 billion. For clean water state revolving funds, the conference committee approved the Senate's level of $1.35 billion, about $175 million more than the House approved and roughly $550 million more than requested. The conference agreement included $332 million for special project grants, about $73 million more than the House's proposal, roughly $232 million more than the Senate approved, and about $304 million more than requested. For drinking water state revolving funds, the conference committee approved $820 million, $45 million more than the House's amount and $5 million less than the Senate approved and the President requested. The conference committee also approved the Administration's request of $885 million for state and tribal administrative grants, which is roughly the same as the amount enacted for FY1999.

Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C.

Predicting the properties of nonequilibrium systems from molecular simulations is a growing area of interest. One important class of problems involves steady state diffusion. To study these cases, a grand canonical molecular dynamics approach has been developed by Heffelfinger and van Swol [J. Chem. Phys., 101, 5274 (1994)]. With this method, the flux of particles, the chemical potential gradients, and density gradients can all be measured in the simulation. In this paper, we present a complementary approach that couples a nonlocal density functional theory (DFT) with a transport equation describing steady-state flux of the particles. We compare transport-DFT predictions to GCMD results for a variety of ideal (color diffusion), and nonideal (uphill diffusion and convective transport) systems. In all cases excellent agreement between transport-DFT and GCMD calculations is obtained with diffusion coefficients that are invariant with respect to density and external fields.

Steady and oscillatory shear 3-D simulations of electro- and magnetorheology in uniaxial and biaxial fields are presented, and compared to the predictions of the chain model. These large scale simulations are three dimensional, and include the effect of Brownian motion. In the absence of thermal fluctuations, the expected shear thinning viscosity is observed in steady shear, and a striped phase is seen to rapidly form in a uniaxial field, with a shear slip zone in each sheet. However, as the influence of Brownian motion increases, the fluid stress decreases, especially at lower Mason numbers, and the striped phase eventually disappears, even when the fluid stress is still high. In a biaxial field, an opposite trend is seen, where Brownian motion decreases the stress most significantly at higher Mason numbers. to account for the uniaxial steady shear data they propose a microscopic chain model of the role played by thermal fluctuations on the rheology of ER and MR fluids that delineates the regimes where an applied field can impact the fluid viscosity, and gives an analytical prediction for the thermal effect. In oscillatory shear, a striped phase again appears in uniaxial field, at strain amplitudes greater than {approx} 0.15, and the …

High resolution, high-speed photography is becoming a prominent diagnostic in ballistic experimentation. The development of high speed cameras utilizing electro-optics and the use of lasers for illumination now provide the capability to routinely obtain high quality photographic records of ballistic style experiments. The purpose of this presentation is to review in a visual manner the progress of this technology and how it has impacted ballistic experimentation. Within the framework of development at LLNL, we look at the recent history of large format high-speed photography, and present a number of photographic records that represent the state of the art at the time they were made. These records are primarily from experiments involving shaped charges. We also present some examples of current photographic technology, developed within the ballistic community, that has application to hydro diagnostic experimentation at large. This paper is designed primarily as an oral-visual presentation. This written portion is to provide general background, a few examples, and a bibliography.

The purpose of this document is to list the Interim Stabilization equipment drawings that are classified as Essential or Support drawings. Essential Drawings: Those drawings identified by the facility staff as necessary to directly support the safe operation of the facility or equipment. Support Drawings: Those drawings identified by the facility staff that further describe the design details of structures, systems or components shown on essential drawings.

The interior of the high-intensity Cs-sputter source used in routine operations at the Center for Accelerator Mass Spectrometry (CAMS) has been computer modeled using the program NEDLab, with the aim of improving negative ion output. Space charge effects on ion trajectories within the source were modeled through a successive iteration process involving the calculation of ion trajectories through Poisson-equation-determined electric fields, followed by calculation of modified electric fields incorporating the charge distribution from the previously calculated ion trajectories. The program has several additional features that are useful in ion source modeling: (1) averaging of space charge distributions over successive iterations to suppress instabilities, (2) Child's Law modeling of space charge limited ion emission from surfaces, and (3) emission of particular ion groups with a thermal energy distribution and at randomized angles. The results of the modeling effort indicated that significant modification of the interior geometry of the source would double Cs{sup +} ion production from our spherical ionizer and produce a significant increase in negative ion output from the source. The results of the implementation of the new geometry were found to be consistent with the model results.

The combustion of organophosphorus compounds is of great interest for the incineration of chemical warfare agent and their use in flame inhibition as halon replacement. The thermochemical data of these species and the reactions involved at high temperature are not well known, despite some recent experimental studies. With BAC-MP4 ab initio estimations as a basis and semi-empirical estimations for many new compounds, the thermochemistry of organophosphorus compounds is studied. New group additivity values are proposed for enthalpies of formation at 298K, entropies and heat capacities of species involving pentavalent phosphorus bonded to carbon, hydrogen, oxygen, fluorine, nitrogen and sulfur atoms. The kinetic of unimolecular elimination is investigated by modeling pyrolysis experiments of DEMP, TEP and DIMP. A new combustion mechanism is described and applied to the modeling of DMMP reaction in a H{sub 2}/O{sub 2} flame.

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Department of Defense's (DOD) implementation of the anthrax vaccination program as it is currently structured, focusing on DOD's: (1) ability to maintain an adequate supply of anthrax vaccine for its immunization schedule; (2) system for recording and tracking servicemembers' vaccinations; and (3) steps to educate servicemembers about the program."

The purpose of this project is to investigate the application of a sorbent-based process for removing and recovering mercury in the flue gas of coal-fired power plants. The process is based on the sorption of mercury by noble metals and the regeneration of the sorbent by thermal means, recovering the desorbed mercury for recycling. ADA Technologies holds a patent on this process (US 5,409,522) and has tested it under conditions typical of municipal waste incinerators. In this process, the noble metal sorbent is thermally regenerated, and the mercury is recovered for commercial recycle or disposal. ADA has adopted the name Mercu-RE to describe its process. ADA has been testing its process under conditions typical of coal-fired power plants where the mercury concentration is low (below 10 {micro}g/m{sup 3}) and little pressure drop can be tolerated. The objective of this program is to develop the Mercu-RE process as a suitable mercury emission control technology for use at coal-fired power plants.

Arrays of Anti-Compton Spectrometer enabled systematic investigations of octupole correlations in the neutron-rich lanthanides. The studies mostly confirm the theoretical expectations of moderate octupole deformation at medium spins in nuclei from this region but in some cases predictions deviate from the experiment. In cesium isotopes strong octupole effects are predicted but not observed and new measurements for {sup 139}Xe suggest octupole effects stronger than expected. Systematics of excitation energy of the 31 states excitations, updated in the present work for Xe isotopes, indicates the N=85 and Z=54 lines as borders for strong octupole correlations. Systematic of electric dipole moment, upgraded in the present work for Ca and Ce isotopes confirms the Z=54 limit and adds new information about local canceling of electric dipole moment at the N=90 neutron number.

A PRIMARY AVENUE FOR EXERCISING CONGRESS'S POWER OF THE purse is the authorization and appropriation of federal spending to carry out government activities. While the power over appropriations is granted to Congress by the U.S. Constitution, the authorization-appropriation process is derived from House and Senate rules. The formal process consists of two sequential steps:

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. To fulfill this requirement, glass samples were heat treated at various times and temperatures. These results will provide guidance to the repository program about conditions to be avoided during shipping, handling and storage of DWPF canistered waste forms.

The topic of Privacy is complex, multi-faceted, and often emotionally laden. This paper will cover the following topics, in an effort to further understanding of federal regulations and activities, the balancing act that necessarily occurs in business, and what role a records manager can play. The topics are: Definitions; The Privacy Act; ''Private'' companies; Potential areas of concern; Expectations; Corporate responsibilities; Case studies; and Records Manager's role.

Several utility steam generator and stress corrosion cracking databases are synthesized with the view of identifying the crevice chemistry that is most consistent with the plant cracking data. Superheated steam and neutral solution environments are found to be inconsistent with the large variations in the observed SCC between different plants, different support plates within a plant, and different crevice locations. While the eddy current response of laboratory tests performed with caustic chemistries approximates the response of the most extensively affected steam generator tubes, the crack propagation kinetics in these tests differ horn plant experience. The observations suggest that there is a gradual conversion of the environment responsible for most steam generator ODSCC from a concentrated, alkaline-forming solution to a progressively more steam-enriched environment.

This paper describes efforts by Argonne National Laboratory to develop a froth flotation process for separating and recovering plastics from mixed plastics waste streams generated from shredding obsolete appliances and automobiles. A process for recovering and separating equivalent-density ABS and HIPS from obsolete appliances was developed and pilot-tested with a through-put of 1,250 lbs/hr. The basic process is outlined; unit operations and equipment are discussed, and material balances are presented. The resulting ABS product was analyzed and its physical and mechanical properties were established. Its properties resembled those of virgin, mid-grade ABS that is commercially sold today and is widely used by the automotive industry. Injection-molding tests were also conducted by automotive-components suppliers, using the 100% recovered ABS. Headlamp back-cans and automotive ventilation-system duct components were injection molded and the results showed that the recovered ABS met the specifications for these applications. These results confirmed that the recovered ABS can be used as a substitute for virgin plastic materials for molding highly complex automotive component designs, and in parts for other durable goods. Economic analysis of a commercial-scale system was also performed using manufacturers' equipment quotes and operating data from the pilot plant, and it predicts a simple payback of …

The spectroscopy of nuclei produced as fragments in the fission process has been undertaken using the EUROGAM II {gamma}-ray multidetector array. The first experiment involved a spontaneously fissioning {sup 248}Cm source and produced neutron-rich nuclei. The data analysis concentrated on the odd-A Ce isotopes and the present contribution details the structure of {sup 151}Ce which results from the strong coupling of the odd neutron to the core. The results of a preliminary analysis of the yrast structure of {sup 138}Te will also be given. In a second experiment performed at the VIVITRON accelerator in Strasbourg, nuclei on the neutron-rich side of the valley of stability were produced via the {sup 28}Si + {sup 176}Yb reaction at 145 MeV bombarding energy. The level schemes of {sup 99}Mo, {sup 101}Tc and {sup 103}Ru have been extended to high spins ({approximately} 20h). Two new high lying structures in {sup 101}Tc are explained with the help of cranked shell model calculations.