Program booklet for the 30th Actinide Separations Conference. Contains agenda and abstracts for 27 poster and 38 oral presentations to be made during the 3-day meeting, May 23-25, 2006.

Soil vapor extraction (SVE) combined with air injectionprovides an efficient way for the cleanup of vadose zone contaminated byvolatile organic chemicals (VOCs). A successful design of an SVE system,however, relies on a good knowledge of the induced gas flow field in thevadose zone. Analytical solutions are available to help understand thegas flow field at steady-state. However, most SVE systems must pass atransient period before reaching steady (or quasi-steady) state and thelength of the period should be system-specific. This paper presents ananalytical solution for transient gas flow in a vadose zone withextraction and injection wells. The transient solution approaches thesteady-state solution as time increases. Calculations have shown that fora shallow well (screened in a depth of less than 10 m) in a vadose zonewith an air permeability of 1 darcy (10-12 m2) or larger, the systemreaches steady-state in just several hours. Decreasing the airpermeability or increasing the screen depth increases the time to reachsteady-state. In practical applications the transient solution may berelatively insignificant in an SVE design. However, the solution can beimportant in site characterization through pneumatic tests. A procedureis provided for applying the dimensionless solution in estimating airpermeability and air-filled porosity. An example is also given to use thetransient solution …

The general principles of scaling are discussed, followed by a survey of the important dimensionless parameters of fluid dynamics including radiation and magnetic fields, and of non-LTE spectroscopy. The values of the parameters are reviewed for a variety of astronomical and laboratory environments. It is found that parameters involving transport coefficients--the fluid and magnetic Reynolds numbers--have enormous values for the astronomical problems that are not reached in the lab. The parameters that measure the importance of radiation are also scarcely reached in the lab. This also means that the lab environments are much closer to LTE than the majority of astronomical examples. Some of the astronomical environments are more magnetically dominated than anything in the lab. The conclusion is that a good astronomical environment for simulation in a given lab experiment can be found, but that the reverse is much more difficult.

Pulse position modulation (PPM) in lasercom systems is known to provide potential advantages over other modulation schemes. [1]. In PPM, a periodic time frame is established and data is transmitted by placing a pulse in any one of several subintervals (or ''slots'') within each frame. In PPM/O-CDMA all users use the same frame structure and each transmits its unique address code in place of the PPM pulse. The advantage of PPM as a pulsed signal format is that (1) a single pulse can transmit multiple bits during each frame; (2) decoding (determining which subinterval contains the pulse) is by comparison rather than threshold tests (as in on-off-keying); (3) each user transmits in only a small fraction of the frame, hence the multi-access interference (MAI) of any user statistically spreads over the entire frame time, reducing the chance of overlap with any other user; and (4) under an average power constraint, increasing frame time increases the peak pulse power (i.e., PPM trades average power for peak power). The most straightforward approach to implementing PPM/O-CDMA data modulator inserts the PPM pulse modulation first, then imposes the O-CDMA coding. A pulsed PPM modulator converts bits (words) into pulse positions. In the case of …

The Actinide Removal Process (ARP) facility and the Modular Caustic Side Solvent Extraction Unit (MCU) are scheduled to begin processing salt waste in fiscal year 2007. A portion of the streams generated in these salt processing facilities will be transferred to the Defense Waste Processing Facility (DWPF) to be incorporated in the glass matrix. Before the streams are introduced, a combination of impact analyses and research and development studies must be performed to quantify the impacts on DWPF processing. The Process Science & Engineering (PS&E) section of the Savannah River National Laboratory (SRNL) was requested via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 to evaluate the impacts on DWPF processing. Simulant Chemical Process Cell (CPC) flowsheet studies have been performed using previous composition and projected volume estimates for the ARP sludge/monosodium titanate (MST) stream. Initial MCU incorporation testing for the DWPF flowsheet indicated unacceptable levels of Isopar{reg_sign}L were collecting in the Sludge Receipt and Adjustment Tank (SRAT) condenser system and unanticipated quantities of modifier were carrying over into the SRAT condenser system. This work was performed as part of Sludge Batch 4 (SB4) flowsheet testing and was reported by Baich et al. Due to changes in the flammability control strategy for DWPF …

Extracellular cues play crucial roles in the transcriptional regulation of tissue-specific genes, but whether and how these signals lead to chromatin remodeling is not understood and subject to debate. Using chromatin immunoprecipitation (ChIP) assays and mammary-specific genes as models, we show here that extracellular matrix (ECM) molecules and prolactin cooperate to induce histone acetylation and binding of transcription factors and the SWI/SNF complex to the {beta}- and ?-casein promoters. Introduction of a dominant negative Brg1, an ATPase subunit of SWI/SNF complex, significantly reduced both {beta}- and ?-casein expression, suggesting that SWI/SNF-dependent chromatin remodeling is required for transcription of mammary-specific genes. ChIP analyses demonstrated that the ATPase activity of SWI/SNF is necessary for recruitment of RNA transcriptional machinery, but not for binding of transcription factors or for histone acetylation. Coimmunoprecipitation analyses showed that the SWI/SNF complex is associated with STAT5, C/EBP{beta}, and glucocorticoid receptor (GR). Thus, ECM- and prolactin-regulated transcription of the mammary-specific casein genes requires the concerted action of chromatin remodeling enzymes and transcription factors.

Nuclear Material Management (NMM) completed a comprehensive study at the request of the Department of Energy Savannah River Operations Office (DOE-SR) in 2004 (Reference 11.1). The study evaluated the feasibility of removal and/or mitigation of the Pu-238 source term in the F-Area Material Storage (FAMS) facility during on-going material storage operations. The study recommended different options to remove and/or mitigate the Pu-238 source term depending on its location within the facility. During April 2005, the Department of Energy (DOE) sent a letter of direction (LOD) to Washington Savannah River Company (WSRC) directing WSRC to implement a new program direction that would enable an accelerated shutdown and decommissioning of FAMS (Reference 11.2). Further direction in the LOD stated that effective December 1, 2006 the facility will be transitioned to begin deactivation and decommissioning (D&D) activities. To implement the LOD, Site D&D (SDD) and DOE agreed the planning end-state would be demolition of the FAMS structure to the building slab. SDD developed the D&D strategy, preliminary cost and schedule, and issued the deactivation project plan in December 2005 (Reference 11.3). Due to concerns and questions regarding the FAMS planning end-state and in support of the project's Critical Decision 1, an alternative study …

The program scope was to affect the heat input and the resultant weld bead geometry by synchronizing robotic weave cycles with desired pulsed waveform shapes to develop process parameters relationships and optimized pulsed gas metal arc welding processes for welding fatique-critical structures of steel, high strength steel, and aluminum. Quality would be addressed by developing intelligent methods of weld measurement that accurately predict weld bead geometry from process information. This program was severely underfunded, and eventually terminated. The scope was redirected to investigate tandem narrow groove welding of steel butt joints during the one year of partial funding. A torch was designed and configured to perform a design of experiments of steel butt weld joints that validated the feasability of the process. An initial cost model estimated a 60% cost savings over conventional groove welding by eliminating the joint preparation and reducing the weld volume needed.

We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will …

Congestion analysis using National Energy Modeling National Energy Modeling System (NEMS) or NEMS-derivatives, such as LBNL-NEMS, is subject to significant caveats because the generation logic inherent in NEMS limits the extent to which interregional transmission can be utilized and intraregional transmission is not represented at all. The EMM is designed primarily to represent national energy markets therefore regional effects may be simplified in ways that make congestion analysis harder. Two ways in particular come to mind. First, NEMS underutilizes the capability of the traditional electric grid as it builds the dedicated and detached grid. Second, it also undervalues the costs of congestion by allowing more transmission than it should, due to its use of a transportation model rather than a transmission model. In order to evaluate benefits of reduced congestion using LBNL-NEMS, Berkeley Lab identified three possible solutions: (1) implement true simultaneous power flow, (2) always build new plants within EMM regions even to serve remote load, and (3) the dedicated and detached grid should be part of the known grid. Based on these findings, Berkeley Lab recommends the following next steps: (1) Change the build logic that always places new capacity where it is needed and allow the transmission …

This study performs a cost and schedule analysis of three Nevada Transportation options that support waste receipt at the repository. Based on the U.S. Department of Energy preference for rail transportation in Nevada (given in the Final Environmental Impact Statement), it has been assumed that a branch rail line would be constructed to support waste receipt at the repository. However, due to potential funding constraints, it is uncertain when rail will be available. The three Nevada Transportation options have been developed to meet a varying degree of requirements for transportation and to provide cost variations used in meeting the funding constraints given in the Technical Direction Letter guidelines for this study. The options include combinations of legal-weight truck, heavy-haul truck, and rail. Option 1 uses a branch rail line that would support initial waste receipt at the repository in 2010. Rail transportation would be the primary mode, supplemented by legal weight trucks. This option provides the highest level of confidence in cost and schedule, lowest public visibility, greatest public acceptability, lowest public dose, and is the recommended option for support of waste receipt. The completion of rail by 2010 will require spending approximately $800 million prior to 2010. Option 2 …

The authors use the relativistic hydrodynamics code Cosmos++ to model the evolution of the radio nebula triggered by the Dec. 27, 2004 giant flare event of soft gamma repeater 1806-20. They primarily focus on the rebrightening and centroid motion occurring subsequent to day 20 following the flare event. They model this period as a mildly relativistic ({gamma} {approx} 1.07-1.67) jetted outflow expanding into the intergalactic medium (IGM). They demonstrate that a jet with total energy {approx} 10{sup 46} ergs confined to a half opening angle {approx} 20{sup o} fits the key observables of this event, e.g. the flux lightcurve, emission map centroid position, and aspect ratio. In particular, they find excellent agreement with observations if the rebrightening is due to the jet, moving at 0.5 c and inclined {approx} 0{sup o}-40{sup o} toward the observer, colliding with a density discontinuity in the IGM at a radius of several 10{sup 16} cm. They also find that a jet with a higher velocity, {approx}> 0.7c, and larger inclination, {approx}> 70{sup o}, moving into a uniform IGM can fit the observations in general, but tends to miss the details of rebrightening. The latter, uniform IGM model predicts an IGM density more than 100 …

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A comprehensive study on the relationship between yield strength, relative density and ligament sizes is presented for nanoporous Au foams. Depth-sensing nanoindentation tests were performed on nanoporous foams ranging from 20 to 42% relative density with ligament sizes ranging from 10 to 900 nm. The Gibson and Ashby yield strength equation for open-cell macro-cellular foams is modified in order to incorporate ligament size effects. This study demonstrates that at the nanoscale, foam strength is governed by ligament size, in addition to relative density. Furthermore, we present the ligament length scale as a new parameter to tailor foam properties and achieve high strength at low densities.

This month's issue has the following articles: (1) Experiments at the Scale of Simulations--Commentary by Tomas Diaz de la Rubia; (2) A New Realm of Materials Science--Livermore scientists are combining experiment, theory, and simulation to study the response of solids to extreme dynamic stresses at nanometer and subnanosecond scales; (3) Planets and Stars under the Magnifying Glass--An international collaboration involving Laboratory scientists has discovered a planet made of rock or ice orbiting a dim star outside our solar system; and (4) Keeping an Eye on the Prize--A Livermore-IBM team uses a new code and the world's fastest computer to set a performance record for a science application.

In the last few years, SAXS of biological materials has been rapidly evolving and promises to move structural analysis to a new level. Recent innovations in SAXS data analysis allow ab initio shape predictions of proteins in solution. Furthermore, experimental scattering data can be compared to calculated scattering curves from the growing data base of solved structures and also identify aggregation and unfolded proteins. Combining SAXS results with atomic resolution structures enables detailed characterizations in solution of mass, radius, conformations, assembly, and shape changes associated with protein folding and functions. SAXS can efficiently reveal the spatial organization of protein domains, including domains missing from or disordered in known crystal structures, and establish cofactor or substrate-induced conformational changes. For flexible domains or unstructured regions that are not amenable for study by many other structural techniques, SAXS provides a unique technology. Here, we present SAXS shape predictions for PCNA that accurately predict a trimeric ring assembly and for a full-length DNA repair glycosylase with a large unstructured region. These new results in combination with illustrative published data show how SAXS combined with high resolution crystal structures efficiently establishes architectures, assemblies, conformations, and unstructured regions for proteins and protein complexes in solution.

Superconducting high resolution fast-neutron calorimetric spectrometers based on {sup 6}LiF and TiB{sub 2} absorbers have been developed. These novel cryogenic spectrometers measure the temperature rise produced in exothermal (n, {alpha}) reactions with fast neutrons in {sup 6}Li and {sup 10}B-loaded materials with heat capacity C operating at temperatures T close to 0.1 K. Temperature variations on the order of 0.5 mK are measured with a Mo/Cu thin film multilayer operated in the transition region between its superconducting and its normal state. The advantage of calorimetry for high resolution spectroscopy is due to the small phonon excitation energies k{sub B}T on the order of {mu}eV that serve as signal carriers, resulting in an energy resolution {Delta}E {approx} (k{sub B}T{sup 2}C){sup 1/2}, which can be well below 10 keV. An energy resolution of 5.5 keV has been obtained with a Mo/Cu superconducting sensor and a TiB{sub 2} absorber using thermal neutrons from a {sup 252}Cf neutron source. This resolution is sufficient to observe the effect of recoil nuclei broadening in neutron spectra, which has been related to the lifetime of the first excited state in {sup 7}Li. Fast-neutron spectra obtained with a {sup 6}Li-enriched LiF absorber show an energy resolution of 16 …

Pentaerythritol tetranitrate (PETN) powders are used to initiate other explosives. During long-term storage, changes in powder properties can cause changes in the initiation performance. Changes in the morphology and surface area of aging powders are observed due to sublimation and growth of PETN crystals through coarsening mechanisms, (e.g. Ostwald ripening, sintering, etc.). In order to alleviate the sublimation of PETN crystals under service conditions, stabilization methods such as thermal cycling and doping with certain impurities during or after the crystallization of PETN have been proposed. In this report we present our work on the effect of impurities on the morphology and activation energy of the PETN crystals. The pure and impurity doped crystals of PETN were grown from supersaturated acetone solution by solvent evaporation technique at room temperature. The difference in the morphology of the impurity-doped PETN crystal compared to pure crystal was examined by optical microscopy. The changes in the activation energies and the evaporation rates are determined by thermogravimetric (TGA) analyses. Our activation energies of evaporation agree with earlier reported enthalpies of vaporization. The morphology and activation energy of PETN crystals doped with Ca, Na, and Fe cations are similar to that for pure PETN crystal, whereas the …

This article describes how to accelerate the convergence of Preconditioned Conjugate Gradient (PCG) type eigensolvers for the computation of several states around the band gap of colloidal quantum dots. Our new approach uses the Hamiltonian from the bulk materials constituent for the quantum dot to design an efficient preconditioner for the folded spectrum PCG method. The technique described shows promising results when applied to CdSe quantum dot model problems. We show a decrease in the number of iteration steps by at least a factor of 4 compared to the previously used diagonal preconditioner.