The stability of tungsten carbide particles in iron-rich and nickel-rich liquid during the laser surface alloying (LSA) process was investigated. Kinetic calculations indicate a rapid dissolution of tungsten carbide particles in iron-rich liquid, as compared with the dissolution rate in nickel-rich liquid. Optical microscopy indicated a heterogeneous microstructure around the tungsten particles that is in agreement with concentration gradients predicted by kinetic calculation. The work demonstrates the applicability of computational thermodynamics and kinetic models for the LSA process.

The authors would like to determine |V{sub cb}| from the exclusive semi-leptonic decay B{yields}D*lv. The differential decay rate is d{Lambda}/dw = G{sub F}{sup 2}/4{pi}{sup 3}(w{sup 2}-1){sup 1/2}m{sub D*}{sup 3} (m{sub B}-m{sub D*}){sup 2}G(w)|V{sub cb}|{sup 2}|F{sub B{yields}D*}(w)|{sup 2}, where w = v {center_dot} v{prime} and G(1) = 1. At zero recoil (w = 1) heavy-quark symmetry requires F{sub B{yields}D*}(1) to be close to 1. So, |V{sub cb}| is determined by dividing measurements of d{Lambda}/dw by the phase space and well-known factors, and extrapolating to w {yields} 1. This yields |V{sub cb}|F{sub B{yields}D*}(1), and F{sub B{yields}D*}(1) is taken from ''theory''. To date models [1] or a combination of a rigorous inequality plus judgement [2] have been used to estimate F{sub B{yields}D*}(1) - 1. In this work [3] they calculate F{sub B{yields}D*}(1) with lattice gauge theory, in the so-called quenched approximation, but the uncertainty from quenching is included in the error budget.

At {nu}Fact'02, the muon-based neutrino factory was confronted with existing and planned neutrino facilities. When it was first discussed in 1999 in Lyon [1], it raised great enthusiasm, especially because it was thought to be the only machine capable of measuring CP violation in the leptonic sector. Since that time the pendulum has partially swung back. Two successive detailed studies [2, 3] have shown that a neutrino Factory and the needed R&D were both expensive. In terms of present experiments, neutrino oscillations have been confirmed at SuperK and SNO and results are soon expected from KamLAND. K2K, MniBOONE, MINOS and CNGS are going ahead and new perspectives have been opened by off-axis pion-based neutrino beams and the approval of the high intensity Japanese Hadron Facility. Crests and troughs of a wave are common in long term projects. They are even healthy because they force us to scrutinize the first ideas and sometimes to invent new ones to reach a realistic and affordable design. This analysis has been applied to target systems (section 2), RF capture and cooling of the muons (section 4) and accelerators (section 5). The new concept of pure electron neutrino or anti-neutrino beams produced by, {beta}-decay is …

This paper describes the approach of dealing with an historic legacy of pharmaceutical manufacturing operations, which arose as a result of the temporary cessation of sea disposal in 1983. The result of that cessation was an accumulation of 1,000 reinforced concrete lined steel drums containing intermediate level nuclear waste of mixed chemical and physical form. Included are the steps taken which established a policy, the resulting strategy and the unique and innovative means by which the plan was implemented. The objective was to reduce the financial liability of the waste contained within the drums by removing those portions that had already decayed, segregating the waste in terms of non disposable and disposable isotopes, size reduction and long-term storage of the residues in a retrievable waste form. As part of this process the Company established a UK strategy which would ensure that the Company was self sufficient in radioactive waste handling storage facilities until the provision of a national facility, currently predicted to be approximately 2040.

Snow samples were collected in southeastern Idaho over two winters to assess trace elements and common ions concentrations in air pollutant fallout across the region. The objectives were to: 1) develop sampling and analysis techniques that would produce accurate measurements of a broad suite of elements and ions in snow, 2) identify the major elements in regional fallout and their spatial and temporal trends, 3) determine if there are unique combinations of elements that are characteristic to the major source areas in the region (source profiles), and 4) use pattern recognition and multivariate statistical techniques (principal component analysis and classical least squares regression) to investigate source apportionment of the fallout to the major source areas. In the winter of 2000-2001, 250 snow samples were collected across the region over a 4-month period and analyzed in triplicate using inductively-coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC). Thirty-nine (39) trace elements and 9 common ions were positively identified in most samples. The data were analyzed using pattern recognition tools in the software, Pirouette® (Infometrix, Inc.). These results showed a large crustal component (Al, Zn, Mn, Ba, and rare earth elements), an overwhelming contribution from phosphate processing facilities located outside Pocatello in …

We study the role of a possible nonet of light scalar mesons in the still interesting [eta] -> 3[p]i decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear chiral Lagrangian of pseudoscalars and vectors extended to include the scalars. The parameters involving the scalars were previously obtained to fit the s-wave [pi][pi] and [pi] K scatterings in the region up to about 1 GeV as well as the strong decay [eta]' --> [eta][pi][pi]. At first, one might expect a large enhancement from diagrams including a light [sigma] (560). However there is an amusing cancellation mechanism which prevents this from occurring. In the simplest model there is an enhancement of about 13 per cent in the [eta] -> 3[pi] decay rate due to the scalars. In a more complicated model which includes derivative type symmetry breakers, the cancellation is modified and the scalars contribute about 30 percent of the total decay rate (although the total is not significantly changed). The vectors do not contribute much. Our model produces a reasonable estimate for the related a{sub 0}(980) - f{sub 0}(980) mixing strength, which has been a topic of current debate. Promising directions …

Spatial channel theory, initially introduced in 1977 by M. L. Williams and colleagues at ORNL, is a powerful tool for shield design optimization. It focuses on so called ''contributon'' flux and current of particles (a fraction of the total of neutrons, photons, etc.) which contribute directly or through their progeny to a pre-specified response, such as a detector reading, dose rate, reaction rate, etc., at certain locations of interest. Particles that do not contribute directly or indirectly to the pre-specified response, such as particles that are absorbed or leak out, are ignored. Contributon fluxes and currents are computed based on combined forward and adjoint transport solutions. The initial concepts were considerably improved by Abu-Shumays, Selva, and Shure by introducing steam functions and response flow functions. Plots of such functions provide both qualitative and quantitative information on dominant particle flow paths and identify locations within a shield configuration that are important in contributing to the response of interest. Previous work was restricted to two dimensional (2-D) x-y rectangular and r-z cylindrical geometries. This paper generalizes previous work to three-dimensional x-y-z geometry, since it is now practical to solve realistic 3-D problems with multidimensional transport programs. As in previous work, new analytic …

This conference paper describes the electronic properties of ZnO/CdS/Cu(In,Ga)Se2 (CIGS)/Mo/SLG polycrystalline thin-film solar cells with compositions ranging from Cu-rich to In-rich were investigated by deep level transient spectroscopy and capacitance-voltage (C-V) measurements. This compositional change represents the evolution of the film during growth by the three-stage process. Four thin-film CIGS samples with different Cu content were obtained. The Cu/(In+Ga) ratio ranges from 1.24 (Cu-rich)to 0.88 (In-rich), whereas the Ga/(In+Ga) ratio ranges from 0.19 (Cu-rich)to 0.28 (In-rich).The Cu-rich sample exhibits a shallow majority-carrier trap with an activation energy of 0.12 eV and another deeper trap with an activation energy of 0.28 eV, whereas the In-rich sample has a shallow minority-carrier trap with an activation energy of 0.12 eV. The two samples show evidence of a deeper trap at higher temperature. C-V measurements showed that the average carrier concentration (N values) around the junction of the cell changed as the film transitions from Cu-rich to In-rich. DLTS shows that acceptor-like traps are dominant in samples where CIGS grains did not go through the Cu-rich to In(Ga)-rich transition. While donor-like traps are dominant in the In(Ga)-rich samples.

A study was conducted to evaluate the effect of compression on pressure drop in flexible, spiral wire helix core ducts used in residential and light commercial applications. Ducts of 6 inches, 8 inches and 10 inches (150, 200 and 250 mm) nominal diameters were tested under different compression configurations following ASHRAE Standard 120-1999--Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The results showed that the available published references tend to underestimate the effects of compression. The study demonstrated that moderate compression in flexible ducts, typical of that often seen in field installations, could increase the pressure drop by a factor of four, while further compression could increase the pressure drop by factors close to ten. The results proved that the pressure drop correction factor for compressed ducts cannot be independent of the duct size, as suggested by ASHRAE Fundamentals, and therefore a new relationship was developed for better quantification of the pressure drop in flexible ducts. This study also suggests potential improvements to ASHRAE Standard 120-1999 and provides new data for duct design.

An experimental study was conducted to evaluate the pressure drop characteristics of residential duct system components that are either not available or not thoroughly (sometimes incorrectly) described in existing duct design literature. The tests were designed to imitate cases normally found in typical residential and light commercial installations. The study included three different sizes of flexible ducts, under different compression configurations, splitter boxes, supply boots, and a fresh air intake hood. The experimental tests conformed to ASHRAE Standard 120P--''Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings''. The flexible duct study covered compressibility and bending effects on the total pressure drop, and the results showed that the available published references tend to underestimate the effects of compression in flexible ducts that can increase pressure drops by up to a factor of nine. The supply boots were tested under different configurations including a setup where a flexible duct elbow connection was considered as an integral part of the supply boot. The supply boots results showed that diffusers can increase the pressure drop by up to a factor of two in exit fittings, and the installation configuration can increase the pressure drop by up to a factor of …

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen or ambient-temperature compressed hydrogen. This flexibility results in multiple advantages with respect to compressed hydrogen tanks or low-pressure liquid hydrogen tanks. Our work is directed at verifying that commercially available aluminum-lined, fiber-wrapped pressure vessels can be safely used to store liquid hydrogen. A series of tests have been conducted, and the results indicate that no significant vessel damage has resulted from cryogenic operation. Future activities include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for certification of insulated pressure vessels.

We are working on developing an Integrated Systems Analysis Environment (ISAE) for application to analysis and optimization of Intelligent Transportation Systems (ITS). ISAE is based on the concept of Co-simulation, which allows the modeling of complex systems with extreme flexibility. Co-simulation allows the development of virtual ITS systems that can be analyzed and optimized as an overall integrated system. The virtual ITS system is defined by selecting different components from a component library. System component models can be written in multiple programming languages running on different computer platforms. At the same time, ISAE provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all system components. Co-simulation has been recently demonstrated using an example of an automotive system. The demonstration was successfully performed. The paper describes plans on how to implement ISAE and Co-simulation to ITS, and the great advantages that this implementation would represent.

A multi-zone model has been developed that accurately predicts HCCI combustion and emissions. The multizone methodology is based on the observation that turbulence does not play a direct role on HCCI combustion. Instead, chemical kinetics dominates the process, with hotter zones reacting first, and then colder zones reacting in rapid succession. Here, the multi-zone model has been applied to analyze the effect of piston crevice geometry on HCCI combustion and emissions. Three different pistons of varying crevice size were analyzed. Crevice sizes were 0.26, 1.3 and 2.1 mm, while a constant compression ratio was maintained (17:1). The results show that the multi-zone model can predict pressure traces and heat release rates with good accuracy. Combustion efficiency is also predicted with good accuracy for all cases, with a maximum difference of 5% between experimental and numerical results. Carbon monoxide emissions are underpredicted, but the results are better than those obtained in previous publications. The improvement is attributed to the use of a 40-zone model, while previous publications used a 10-zone model. Hydrocarbon emissions are well predicted. For cylinders with wide crevices (1.3 and 2.1 mm), HC emissions do not decrease monotonically as the relative air/fuel ratio ({lambda}) increases. Instead, maximum HC …

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen or ambient-temperature compressed hydrogen. This flexibility results in multiple advantages with respect to compressed hydrogen tanks or low-pressure liquid hydrogen tanks. Our work is directed at verifying that commercially available aluminum-lined, fiber-wrapped pressure vessels can be safely used to store liquid hydrogen. A series of tests have been conducted, and the results indicate that no significant vessel damage has resulted from cryogenic operation. Future activities include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for certification of insulated pressure vessels.

We are working on developing an alternative technology for storage of hydrogen or natural gas on light-duty vehicles. This technology has been titled insulated pressure vessels. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept either liquid fuel or ambient-temperature compressed fuel. Insulated pressure vessels offer the advantages of cryogenic liquid fuel tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for fuel liquefaction and reduced evaporative losses). The work described in this paper is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen or LNG. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Future activities include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining insulated pressure vessel certification.

This paper shows how a computer can systematically remove non-essential chemical reactions from a large chemical kinetic mechanism. The computer removes the reactions based upon a single solution using a detailed mechanism. The resulting reduced chemical mechanism produces similar numerical predictions significantly faster than predictions that use the detailed mechanism. Specifically, a reduced chemical kinetics mechanism for iso-octane has been derived from a detailed mechanism by eliminating unimportant reaction steps and species. The reduced mechanism has been developed for the specific purpose of fast and accurate prediction of ignition timing in an HCCI engine. The reduced mechanism contains 199 species and 383 reactions, while the detailed mechanism contains 859 species and 3606 reactions. Both mechanisms have been used in numerical simulation of HCCI combustion. The simulations show that the reduced mechanism predicts pressure traces and heat release with good accuracy, similar to the accuracy obtained with the detailed mechanism. As may be expected, emissions of hydrocarbon and carbon monoxide are not as well predicted with the reduced mechanism as with the detailed mechanism, since the reduced mechanism was targeted for predicting HCCI ignition and not HC and CO emissions. Considering that the reduced mechanism requires about 25 times less computational …

Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work.

Article on the solubility of crystalline nonelectrolyte solutes in organic solvents and the mathematical correlation of benzil solubilities with the Abraham general solvation model.

The Environmental Protection Agency (EPA) is currently evaluating alternative treatment standards for radioactively contaminated high mercury (Hg) subcategory wastes, which do not require the removal of mercury from the waste. The Sulfur Polymer Stabilization/Solidification (SPSS) process developed at Brookhaven National Laboratory is one of several candidate technologies capable of successfully treating various Hg waste streams. To supplement previously supplied data on treatment of soils, EPA needed additional data concerning stabilization of high Hg subcategory waste sludges. To this end, a 5000 ppm sludge surrogate, containing approximately 50 wt% water, was successfully treated by pilot-scale SPSS processing. In two process runs, 85 and 95 wt% of water was recovered from the sludge during processing. At waste loadings of 46 wt% (30 wt% dry) sludge, the treated waste form had no detectable mercury (<10 ppb) in TCLP leachates. Data gathered from the demonstration of treatment of this sludge will provide the EPA with information to support revisions to current treatment requirements for high Hg subcategory wastes.

Both the theoretical basis and computational approach for extending the capabilities of a spectral line broadening code are presented. Following standard line broadening theory, the effects of an external magnetic field are incorporated into the atomic Hamiltonian and plasma average. In the presence of an external magnetic field the atomic Hamiltonian angular properties are altered--atomic energy levels are perturbed and the spectral emission line is polarized. The magnetic field introduces a preferential axis that changes the plasma average. These extensions have been incorporated into a new spectral line broadening code that is applied to several problems of importance to the understanding of tokamak edge plasmas. Applications fall into two broad categories: (1) determination of local plasma properties from distinct line shape features; and (2) consideration of global plasma phenomenon, such as radiation transport. Observable features of the Zeeman effect make H{sub {alpha}} a good magnetic field diagnostic. H{sub {beta}} does not make a good electron density diagnostic since the Zeeman effect is comparable to the Stark effect for a majority of tokamak edge plasma conditions. When optically thick lines exist the details of the spectral line shapes are shown to significantly influence the transport of radiation throughout the system.

Aluminum-based spent nuclear fuel from foreign and domestic research reactors is being consolidated at the Savannah River Site (SRS) for ultimate disposal in the Monitored Geologic Repository. The melt-dilute treatment technology has been developed to consolidate fuel assemblies by a melting/casting process in which depleted uranium is added to reduce enrichment below 20 percent 235-U. The melt-dilute product is essentially a binary uranium-aluminum alloy to which neutron absorber materials may be readily added.

This effort will provide a technical basis to assure safe and efficient system operation of the melt-dilute process and have general applicability to off-gas streams.

This paper reviews the candidate legacy materials and addresses adaptation of the melt-dilute technology to treat DOE legacy waste streams.

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