Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous phase by a factor of 15. Because of the lower viscosity, the CO{sub 2} displacement front will have a tendency towards instability so that waves or rounded lobes of saturation may appear and grow into fingers that lead to enhanced dissolution, bypassing, and possibly poor sweep efficiency. This paper presents an analysis, through high-resolution numerical simulations, of the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. We explore the influence of viscosity ratio, relative permeability functions, and capillary pressure on finger growth and spacing. In addition, we address the issues of finger triggering, convergence under grid refinement and boundary condition effects. Simulations were carried out on scalar machines, and on an IBM RS/6000 SP (a distributed-memory parallel computer with 6080 processors) with a parallelized version of TOUGH2.

Modeling coupled water-gas-rock interactions in unsaturated fractured rock requires conceptual and numerical model considerations beyond those developed for saturated porous media. This paper focuses on the integration of the geological and hydrological parameters into the calculation of reactive-transport parameters and the feedback of mineral precipitation/dissolution to flow and transport. These basic relations have been implemented in the reactive transport code TOUGHREACT (Xu et al., 2003) that couples equilibrium and kinetic water-gas-rock inter-actions with multiphase flow and aqueous and gaseous species transport. Simulation results are presented illustrating the effects of water-rock interaction accompanying the heating of unsaturated heterogeneous fractured tuff. Unknowns associated with modeling water-rock interaction in fractured unsaturated systems are the area of the fracture surface that is wetted and which fractures are active components of the overall flow system. The wetted fracture area is important not only to water-rock interaction but to flow and transport between fluids flowing in fractures and the adjacent matrix. The other unknown relations are those describing permeability and capillary pressure modification during mineral precipitation and dissolution. Here we discuss solely the relations developed for fractures and the fracture-matrix interface.

None

A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research …

Superconducting combined function magnets will be utilized for the 50GeV-750kW proton beam line for the J-PARC neutrino experiment and an R and D program has been launched at KEK. The magnet is designed to provide a combined function with a dipole field of 2.59 T and a quadrupole field of 18.7 T/m in a coil aperture of 173.4 mm. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2-D cross-section results in left-right asymmetry. This paper reports the design study of the magnet.

The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 300T{center_dot}m and 10OT{center_dot}m. Fast ramp times are needed. These can cause problems of ac loss and field distortion in the magnets. For the high energy ring, a lm model dipole magnet has been built, based on the RHIC dipole design. This magnet was tested under boiling liquid helium in a vertical dewar. The quench current showed very little dependence on ramp rate. The ac losses, measured by an electrical method, were fitted to straight line plots of loss/cycle versus ramp rate, thereby separating the eddy current and hysteresis components. These results were compared with calculated values, using parameters which had previously been measured on short samples of cable. Reasonably good agreement between theory and experiment was found, although the measured hysteresis loss is higher than expected in ramps to the highest field levels.

The production of a Higgs boson in association with a pair of e quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p{bar p}, pp {yields} t{bar t}h. We conclude by briefly discussing the case of exclusive b{bar b}h production and the potential of this process in revealing signals of new physics beyond the Standard Model.

The Picosecond Laser-Electron Inter-Action for the Dynamic Evaluation of Structures (PLEIADES) facility, is a unique, novel, tunable (10-200 keV), ultrafast (ps-fs), hard x-ray source that greatly extends the parameter range reached by existing 3rd generation sources, both in terms of x-ray energy range, pulse duration, and peak brightness at high energies. First light was observed at 70 keV early in 2003, and the experimental data agrees with 3D codes developed at LLNL. The x-rays are generated by the interaction of a 50 fs Fourier-transform-limited laser pulse produced by the TW-class FALCON CPA laser and a highly focused, relativistic (20-100 MeV), high brightness (1 nC, 0.3-5 ps, 5 mm.mrad, 0.2% energy spread) photo-electron bunch. The resulting x-ray brightness is expected to exceed 10{sup 20} ph/mm{sup 2}/s/mrad{sup 2}/0.1% BW. The beam is well-collimated (10 mrad divergence over the full spectrum, 1 mrad for a single color), and the source is a unique tool for time-resolved dynamic measurements in matter, including high-Z materials.

Accelerator control system applications at Berkeley Lab's Advanced Light Source (ALS) are typically deployed on operator consoles running Microsoft Windows 2000 and utilize EPICS[2]channel access for data access. In an effort to accommodate the wide variety of Windows based development tools and developers with little experience in network programming, ActiveX controls have been deployed on the operator stations. Use of ActiveX controls for use in the accelerator control environment has been presented previously[1]. Here we report on some of our experiences with the use and development of these controls.

Non-invasive, high resolution geophysical mapping of the shallow subsurface is necessary for delineation of buried hazardous wastes, detecting unexploded ordinance, verifying and monitoring of containment or moisture contents, and other environmental applications. Electromagnetic (EM) techniques can be used for this purpose since electrical conductivity and dielectric permittivity are representative of the subsurface media. Measurements in the EM frequency band between 1 and 100 MHz are very important for such applications, because the induction number of many targets is small and the ability to determine the subsurface distribution of both electrical properties is required. Earlier workers were successful in developing systems for detecting anomalous areas, but quantitative interpretation of the data was difficult. Accurate measurements are necessary, but difficult to achieve for high-resolution imaging of the subsurface. We are developing a broadband non-invasive method for accurately mapping the electrical conductivity and dielectric permittivity of the shallow subsurface using an EM impedance approach similar to the MT exploration technique. Electric and magnetic sensors were tested to ensure that stray EM scattering is minimized and the quality of the data collected with the high-frequency impedance (HFI) system is good enough to allow high-resolution, multi-dimensional imaging of hidden targets. Additional efforts are being made …

Superconducting insertion devices, which produce periodic magnetic fields, have been built and installed in a number of synchrotron-light source storage-rings. For the most part, these devices have been wigglers, which have relatively long period lengths. This report concerns itself with the special cryogenic issues associated with short period undulators. The motivation for considering the incorporation of superconducting technology in insertion device designs is to achieve higher magnetic fields than can be achieved with more conventional permanent magnet technology. Since the peak field decreases sharply with increased magnet gap to period ratio, the cryogenic design of the magnet system is crucial. In particular, the insulation required for a warm vacuum bore device is impractical for short period undulators. This report describes the issues that are related to a cold bore ({approx}4 K) and an intermediate temperature bore (30 to 70 K) designs. The criteria for the use of small cryocoolers for cooling a short period undulator are presented. The problems associated with connecting small coolers to an undulator at 4.2 K are discussed.

The Muon Ionization Cooling Experiment (MICE) has three 350-mm long liquid hydrogen absorbers to reduce the momentum of 200 MeV muons in all directions. The muons are then re-accelerated in the longitudinal direction by 200 MHz RF cavities. The result is cooled muons with a reduced emittance. The energy from the muons is taken up by the liquid hydrogen in the absorber. The hydrogen in the MICE absorbers is cooled by natural convection to the walls of the absorber that are in turn cooled by helium gas that enters at 14 K. This report describes the MICE liquid hydrogen absorber and the heat exchanger between the liquid hydrogen and the helium gas that flows through passages in the absorber wall.

This report describes a design for focusing solenoids for the low beta sections for the proposed Muon Ionization Cooling Experiment (MICE). There are three focusing solenoid pairs that will be around the muon absorbers for MICE. The two solenoid coils have an inside diameter of 510 mm, a length of 180 mm, and a thickness of 100 mm. A distance of 260 mm separates the two coils in the pair. The coils are designed to operate at opposite polarity, in order to create a gradient field in the low beta sections of the MICE cooling channel. As result, the force pushing the coil pair apart approaches 270 metric tons when the coils operate close to the short sample current for the superconductor. The forces between the coils will be carried by a support structure that is both on the inside and the outside the coils. During some modes of operation for MICE, the coils may operate at the same polarity, which means that the force between the coils pushes them together. The focusing magnet must be designed for both modes of operation. This support structure for the coils will be part of the focusing magnet quench protection system.

The sustainable design of complex building types such as laboratories and hospitals can be particularly challenging, given their inherent complexity of systems, health and safety requirements, long-term flexibility and adaptability needs, energy use intensity, and environmental impacts. Tools such as design guides, energy benchmarking, and LEED rating systems are especially helpful to support sustainable design in such buildings. Furthermore, designers need guidance on how to effectively and appropriately use each tool within the context of an integrated design process involving multiple actors with various objectives. Toward this end, the Laboratories for the 21st Century (Labs21) program has developed an interlinked set of tools -- the Labs21 Toolkit -- to support an integrated design process for sustainable laboratories. Labs21 is a voluntary partnership program sponsored by the U.S. Environmental Protection Agency (EPA) and U.S. Department of Energy (DOE) to improve the environment al performance of U.S. laboratories. In this paper, we present the Labs21 Toolkit, and illustrate how these tools can be used to support sustainable design within an integrated design process. The tool kit includes core information tools, as well as process-related tools, as indicated below: Core information tools: -A Design Guide, which is a compendium of publications on energy …

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi, USA. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene (B), toluene (T), ethyl benzene (E), and xylene (X). The second, a reactive pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rate constants associated with each of the K zones. In both the mass loss model and the reactive pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distributions is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.

Arcing is a well-known, unwanted discharge regime observed on the surface of sputtering targets. The discharge voltage breaks down to less than 50 V while the current jumps to elevated levels. Arcing is unwanted because it prevents uniform deposition and creates particulates. The issue of arcing has been dealt with by target surface conditioning and by using modern power supplies that have arc suppression incorporated. With increasing quality requirements in terms of uniformity of coatings, and absence of particulates, especially for electrochromic and other advanced coatings applications, the issue of arcing warrants a closer examination with the goal to find other, physics-based, and hopefully better approaches of arcing prevention. From a physics point of view, the onset of arcing is nothing else than the transition of the discharge to a cathodic arc mode, which is characterized by the ignition of non-stationary arc spots. Arc spots operate by a sequence of microexplosions, enabling explosive electron emission, as opposed to secondary electron emission. Arc spots and their fragments have a size distribution in the micrometer and sub-micrometer range, and a characteristic time distribution that has components shorter than microseconds. Understanding the ignition conditions of arc spots are of central physical interest. Spot …

None

Genomic instability is a hallmark of breast and other solid cancers. Presumably caused by critical telomere reduction, GI is responsible for providing the genetic diversity required in the multi-step progression of the disease. We have used multicolor fluorescence in situ hybridization and 3D image analysis to quantify genomic instability cell-by-cell in thick, intact tissue sections of normal breast epithelium, preneoplastic lesions (usual ductal hyperplasia), ductal carcinona is situ or invasive carcinoma of the breast. Our in situ-cell by cell-analysis of genomic instability shows an important increase of genomic instability in the transition from hyperplasia to in situ carcinoma, followed by a reduction of instability in invasive carcinoma. This pattern suggests that the transition from hyperplasia to in situ carcinoma corresponds to telomere crisis and invasive carcinoma is a consequence of telomerase reactivation afertelomere crisis.

This paper presents a field modeling study characterizing fluid flow and tracer transport in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository for storing high-level radioactive waste. The 500 to 700 meter thick unsaturated zone of Yucca Mountain consists of highly heterogeneous layers of anisotropic, fractured ash flow and air fall tuffs. Characterization of fluid flow and heat transfer through such a system has been a challenge due to the heterogeneities prevalent on various scales. Quantitative evaluation of water, gas, and heat flow by means of numerical simulation is essential for design and performance assessment of the repository. A three-dimensional numerical flow and transport model will be discussed. The model has been calibrated against field-measured data and takes into account the coupled processes of unsaturated flow and tracer transport in the highly heterogeneous, unsaturated fractured porous rock. The modeling approach of the model is based on a dual-continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. As application examples, effects of current and future climates on the unsaturated zone processes are evaluated to aid in the assessment of the proposed repository's system performance.

While the most familiar consequences of specimen charging in transmission electron microscopy can be eliminated by evaporating a thin conducting film (such as a carbon film) onto an insulating specimen, or by preparing samples directly on such a conducting film to begin with, a more subtle charging effect still remains. We argue here that specimen charging is in this case likely to produce a dipole sheet rather than a layer of positive charge at the surface of the specimen. A simple model of the factors that control the kinetics of specimen charging, and its neutralization, is discussed as a guide for experiments that attempt to minimize the amount of specimen charging. Believable estimates of the electrostatic forces and the electron optical disturbances that are likely to occur suggest that specimen bending and warping may have the biggest impact on degrading the image quality at high resolution. Electron optical effects are likely to be negligible except in the case of a specimen that is tilted to high angle. A model is proposed to explain how both the mechanical and electron-optical effects of forming a dipole layer would have much greater impact on the image resolution in a direction perpendicular to the …

Both the apolipoprotein A5 and C3 genes have repeatedly been shown to play an important role in determining plasma triglyceride concentrations in humans and mice. In mice, transgenic and knockout experiments indicate that plasma triglyceride levels are negatively and positively correlated with APOA5 and APOC3 expression, respectively. In humans, common polymorphisms in both genes have also been associated with plasma triglyceride concentrations. The evolutionary relationship among these two apolipoprotein genes and their close proximity on human chromosome 11q23 have largely precluded the determination of their relative contribution to altered Both the apolipoprotein A5 and C3 genes have repeatedly been shown to play an important role in determining plasma triglyceride concentrations in humans and mice. In mice, transgenic and knockout experiments indicate that plasma triglyceride levels are negatively and positively correlated with APOA5 and APOC3 expression, respectively. In humans, common polymorphisms in both genes have also been associated with plasma triglyceride concentrations. The evolutionary relationship among these two apolipoprotein genes and their close proximity on human chromosome 11q23 have largely precluded the determination of their relative contribution to altered triglycerides. To overcome these confounding factors and address their relationship, we generated independent lines of mice that either over-expressed (''double transgenic'') or …

A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed.

OAK-B135 Stopped-flow was used to evaluate the methylation and reduction kinetics of the isolated alpha subunit of acetyl-Coenzyme A synthase from Moorella thermoacetica. This catalytically active subunit contains a novel Ni-X-Fe4S4 cluster and a putative unidentified n =2 redox site called D. The D-site must be reduced for a methyl group to transfer from a corrinoid-iron-sulfur protein, a key step in the catalytic synthesis of acetyl-CoA. The Fe4S4 component of this cluster is also redox active, raising the possibility that it is the D-site or a portion thereof. Results presented demonstrate that the D-site reduces far faster than the Fe4S4 component, effectively eliminating this possibility. Rather, this component may alter catalytically important properties of the Ni center. The D-site is reduced through a pathway that probably does not involve the Fe4S4 component of this active-site cluster.

We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis.