A primary purpose of computational models is to inform design decisions and, in order to make those decisions reliably, the confidence in the results of such models must be estimated. Monte Carlo neutron transport models are common tools for reactor designers. These types of models contain several sources of uncertainty that propagate onto the model predictions. Two uncertainties worthy of note are (1) experimental and evaluation uncertainties of nuclear data that inform all neutron transport models and (2) statistical counting precision, which all results of a Monte Carlo codes contain. Adjoint-based implicit uncertainty analyses allow for the consideration of any number of uncertain input quantities and their effects upon the confidence of figures of merit with only a handful of forward and adjoint transport calculations. When considering a rich set of uncertain inputs, adjoint-based methods remain hundreds of times more computationally efficient than Direct Monte-Carlo methods. The LIFE (Laser Inertial Fusion Energy) engine is a concept being developed at Lawrence Livermore National Laboratory. Various options exist for the LIFE blanket, depending on the mission of the design. The depleted uranium hybrid LIFE blanket design strives to close the fission fuel cycle without enrichment or reprocessing, while simultaneously achieving high discharge …

Limitations on petroleum-based diesel fuel in California could occur pursuant to the 1998 declaration by California's Air Resources Board (CARB) that the particulate matter component of diesel exhaust is a carcinogen, therefore a toxic air contaminant (TAC) subject to the state's Proposition 65. It is the declared intention of CARB not to ban or restrict diesel fuel per se, at this time. Assuming no total ban, Argonne National Laboratory (ANL) explored two feasible mid-course strategies, each of which results in some degree of (conventional) diesel displacement. In the first case, with substantial displacement of compression-ignition by spark-ignition engines, diesel fuel is assumed admissible for ignition assistance as a pilot fuel in natural gas (NG)-powered heavy-duty vehicles. Gasoline demand in California increases by 32.2 million liters (8.5 million gallons) per day overall, about 21% above projected 2010 baseline demand. Natural gas demand increases by 13.6 million diesel liter (3.6 million gallon) equivalents per day, about 7% above projected (total) consumption level. In the second case, compression-ignition engines utilize substitutes for petroleum-based diesel having similar ignition and performance properties. For each case the authors estimated localized air emission plus generalized greenhouse gas and energy changes. Fuel replacement by di-methyl ether yields the …

A methodology for modeling gaseous injection has been refined and applied to recent experimental data from the literature. This approach uses a discrete phase analogy to handle gaseous injection, allowing for addition of gaseous injection to a CFD grid without needing to resolve the injector nozzle. This paper focuses on model testing to provide the basis for simulation of hydrogen direct injected internal combustion engines. The model has been updated to be more applicable to full engine simulations, and shows good agreement with experiments for jet penetration and time-dependent axial mass fraction, while available radial mass fraction data is less well predicted.

This report talks about Application of Moments Method to Dynamics of Muon Cooling System

The most striking feature of BTeV, a dedicated b physics experiment which is expected to begin running in 2008 in the new CZero interaction region of the Fermilab Tevatron, is that the experiment will use data from a pixel vertex detector to reconstruct tracks and vertices for every beam crossing. The lowest level trigger will be an impact parameter trigger designed to identify events containing reconstructable decays of charm and bottom particles[1]. An R&D program to develop a pixel readout chip optimized for the Tevatron was started at Fermilab in 1997, and is now nearing completion. The architecture of the BTeV pixel readout chip is described in this paper.

Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the High Energy Physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. Although there are many computer programs for beam physics simulations, Geant4 is ideal to model a beam going through material or a system with a beam line integrated to a complex detector. There are many examples in the current international High Energy Physics programs, such as studies related to a future Neutrino Factory, a Linear Collider, and a very Large Hadron Collider.

Microbiologically influenced corrosion (MIC) may decrease the functional lifetime of nuclear waste packaging materials in the potential geologic repository at Yucca Mountain (YM), Nevada. Biochemical contributions to corrosion of package materials are being determined in reactors containing crushed repository-site rock with the endogenous microbial community, and candidate waste package materials. These systems are being continually supplied with simulated ground water. Periodically, bulk chemistries are analyzed on the system outflow, and surfacial chemistries are assessed on withdrawn material coupons. Both Fe and Mn dissolved from C1020 coupons under conditions that included the presence of YM microorganisms. Insoluble corrosion products remained in a reduced state at the coupon surface, indicating at least a localized anoxic condition; soluble reduced Mn and Fe were also detected in solution, while precipitated and spalled products were oxidized. Alloy 22 surfaces showed a layer of chrome oxide, almost certainly in the Cr(III) oxidation state, on microcosm-exposed coupons, while no soluble chrome was detected in solution. The results of these studies will be compared to identical testing on systems containing sterilized rock to generate, and ultimately predict, microbial contributions to waste package corrosion chemistries.

High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In time-of-flight mass spectrometry cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above {approx}50 kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.

BTeV is an approved forward collider experiment at the Fermilab Tevatron dedicated to the precision studies of CP violation, mixing, and rare decays of beauty and charm hadrons. The BTeV detector has been designed to achieve these goals. One of the unique features of BTeV is a state-of-the-art pixel detector system, designed to provide accurate measurements of the decay vertices of heavy flavor hadrons that can be used in the first trigger level. The pixel vertex detector and the trigger design are described. Recent results on some of the achievements in the R and D effort are presented.

For years, contamination has been known to degrade the performance of optics and to sometimes initiate laser-induced damage to initiate. This study has W to quantify these effects for fused silica windows used at 355 mm Contamination particles (Al, Cu, TiO{sub 2} and ZrO{sub 2}) were artificially deposited onto the surface and damage tests were conducted with a 3 ns NdYAG laser. The damage morphology was characterized by Nomarski optical microscopy. The results showed that the damage morphology for input and output surface contamination is different. For input surface contamination, both input and output surfaces can damage. In particular, the particle can induce pitting or drilling of the surface where the beam exits. Such damage usually grows catastrophically. Output surface contamination is usually ablated away on the shot but can also induce catastrophic damage. Plasmas are observed during illumination and seem to play an important role in the damage mechanism. The relationship between fluence and contamination size for which catastrophic damage occurred was plotted for different contamination materials. The results show that particles even as small as 10 {micro}m can substantially decrease the damage threshold of the window and that metallic particles on the input surface have a more negative …

Following the successful RunI from 1992 to 1996, the CDF detector has undergone a major upgrade [1] for the RunII which begun in March 2001. The approval for the addition of a Time-of-Flight detector was granted in January 1999. The installation of the TOF detector was completed in August 2001 and its data has been included in the CDFII readout since then. The primary physics motivation for TOF is to complement and enhance the particle identification capability provided by the central drift chamber (COT) since it distinguishes K{sup {+-}} and {pi}{sup {+-}} in the momentum region of their cross-over in dE=dX. With an expected time-of-flight resolution of 100 ps, the TOF system will be capable of identifying charged kaons from pions by their flight time difference with at least two standard deviation separation up to kaon momenta of 1.6 GeV/c. Such an addition results in an enhancement of the b flavor identification power, crucial to improve the statistical precision in CP violation and B{sub s} mixing measurements.

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We report recent measurements of branching fractions and charge asymmetries of charmless hadronic B decays using the data collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} collider.

Several proof-of-principle laser accelerator experiments turned a long-wavelength of a CO{sub 2} laser to advantage. Ongoing advancement to multi-terawatt femtosecond CO{sub 2} lasers opens new venues for next-generation laser acceleration research.

We conduct a series of high-resolution, fully self-consistent dissipation less N-body simulations to investigate the cumulative effect of substructure mergers onto thin disk galaxies in the context of the {Lambda}CDM paradigm of structure formation. Our simulation campaign is based on a hybrid approach combining cosmological simulations and controlled numerical experiments. Substructure mass functions, orbital distributions, internal structures, and accretion times are culled directly from cosmological simulations of galaxy-sized cold dark matter (CDM) halos. We demonstrate that accretions of massive subhalos onto the central regions of host halos, where the galactic disk resides, since z {approx} 1 should be common occurrences. In contrast, extremely few satellites in present-day CDM halos are likely to have a significant impact on the disk structure. This is due to the fact that massive subhalos with small orbital pericenters that are most capable of strongly perturbing the disk become either tidally disrupted or suffer substantial mass loss prior to z = 0. One host halo merger history is subsequently used to seed controlled N-body experiments of repeated satellite impacts on an initially-thin Milky Way-type disk galaxy. These simulations track the effects of six dark matter substructures, with initial masses in the range {approx} (0.7-2) x 10{sup …

We simulated the flow field and flame propagation near top dead center in a generic large-bore internal combustion engine using the COYOTE computer program, which is based on the full Navier-Stokes equations for a fluid mixture. The combustion chamber is a right circular cylinder, and the main charge is uniformly premixed. The calculations are axisymmetric. The results illustrate the differences in flow patterns, flame propagation, and thermal NO production between ignition with a spark plug and with a small prechamber. In the spark-ignited case, the flame propagates away from the spark plug approximately as a segment of a spherical surface, just as expected. With the prechamber, a high speed jet of hot combustion products shoots into the main chamber, quickly producing a large flame sheet that spreads along the piston face. The prechamber run consumes all of the fuel in half the time required by the spark-ignited case. The two cases produce comparable amounts of thermal NO at the end of fuel combustion.

This report describes the findings and recommendations resulting from the Department of Homeland Security (DHS) Incident Management Simulation Workshop held by the DHS Advanced Scientific Computing Program in May 2004. This workshop brought senior representatives of the emergency response and incident-management communities together with modeling and simulation technologists from Department of Energy laboratories. The workshop provided an opportunity for incident responders to describe the nature and substance of the primary personnel roles in an incident response, to identify current and anticipated roles of modeling and simulation in support of incident response, and to begin a dialog between the incident response and simulation technology communities that will guide and inform planned modeling and simulation development for incident response. This report provides a summary of the discussions at the workshop as well as a summary of simulation capabilities that are relevant to incident-management training, and recommendations for the use of simulation in both incident management and in incident management training, based on the discussions at the workshop. In addition, the report discusses areas where further research and development will be required to support future needs in this area.

Our group is leading a large-sale demonstration of dredged material decontamination technologies for the New York/New Jersey Harbor. The goal of the project is to assemble a complete system for economic transformation of contaminated dredged material into an environmentally-benign material used in the manufacture of a variety of beneficial use products. This requires the integration of scientific, engineering, business, and policy issues on matters that include basic knowledge of sediment properties, contaminant distribution visualization, sediment toxicity, dredging and dewatering techniques, decontamination technologies, and product manufacturing technologies and marketing. A summary of the present status of the system demonstrations including the use of both existing and new manufacturing facilities is given here. These decontamination systems should serve as a model for use in dredged material management plans of regions other than NY/NJ Harbor, such as Long Island Sound, where new approaches to the handling of contaminated sediments are desirable.

Continuum mechanics relies on the fundamental notion of amesoscopic volume "element" in which properties averaged over discreteparticles obey deterministic relationships. Recent work on granularmaterials suggests a continuum law may be inapplicable, revealinginhomogeneities at the particle level, such as force chains and slow cagebreaking. Here, we analyze large-scale Discrete-Element Method (DEM)simulations of different granular flows and show that a "granularelement" can indeed be defined at the scale of dynamical correlations,roughly three to five particle diameters. Its rheology is rather subtle,combining liquid-like dependence on deformation rate and solid-likedependence on strain. Our results confirm some aspects of classicalplasticity theory (e.g., coaxiality of stress and deformation rate),while contradicting others (i.e., incipient yield), and can guide thedevelopment of more realistic continuum models.

Pulmonary embolism (PE) is a significant medical problem that results in over 300,000 fatalities per year. A common preventative treatment for PE is the insertion of a metallic filter into the inferior vena cava that traps thrombi before they reach the lungs. The goal of this work is to use methods of mathematical modeling and design optimization to determine the configuration of trapped thrombi that minimizes the hemodynamic disruption. The resulting configuration has implications for constructing an optimally designed vena cava filter. Computational fluid dynamics is coupled with a nonlinear optimization algorithm to determine the optimal configuration of trapped model thrombus in the inferior vena cava. The location and shape of the thrombus are parameterized, and an objective function, based on wall shear stresses, determines the worthiness of a given configuration. The methods are fully automated and demonstrate the capabilities of a design optimization framework that is broadly applicable. Changes to thrombus location and shape alter the velocity contours and wall shear stress profiles significantly. For vena cava filters that trap two thrombi simultaneously, the undesirable flow dynamics past one thrombus can be mitigated by leveraging the flow past the other thrombus. Streamlining the shape of thrombus trapped along the …

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Objective was to develop sodium titanate (ST) microspheres, made by the HMTA (hexamethylenetetramine) internal gelation process, to remove radionuclides and heavy metals from waste streams at DOE sites. to determine the optimum amount of ST that can be embedded in hydrous Ti oxide (HTO) microspheres, batches of 9.2 to 23.3% ST in HTO were prepared. Crush strength of the air-dried microspheres was found to be highest. Sr was removed from simulated supernatant by all composite microspheres; 13.2% ST/HTO worked best.

The authors studied diets of nestling red-cockaded woodpeckers for two years on three sites in South Carolina and Georgia. Cameras recorded 33 different types of prey. Wood roaches were the most common, amounting to 50% of the prey. In addition, blueberries and saw fly larvae were collected by birds. Snail shells were also collected. Morista's index of diet overlap ranged from 0.94 to 0.99 for breeding males and females. We conclude that nestling diets are similar across the region.

As part of a study of carbon-tritium co-deposition, we carried out an experiment on DIII-D involving a toroidally symmetric injection of {sup 13}CH{sub 4} at the top of a LSN discharge. A Monte Carlo code, DIVIMP-HC, which includes molecular breakup of hydrocarbons, was used to model the region near the puff. The interpretive analysis indicates a parallel flow in the SOL of M{sub l} {approx} 0.4 directed toward the inner divertor. The CH{sub 4} is ionized in the periphery of the SOL and so the particle confinement time, {tau}{sub c}, is not high, only {approx}5 ms, and about 4X lower than if the CH{sub 4} were ionized at the separatrix. For such a wall injection location, however, most of the CH{sub 4} gets ionized to C{sup +}, C{sup ++}, etc., and is efficiently transported along the SOL to the inner divertor, trapping hydrogen by co-deposition there.