legislation worldwide necessitates the development of pollution control systems capable of enabling engines to meet the incoming legislative requirements. It is clear that to maximize the benefit to the environment, as well as to meet the very stringent future standards (especially the US 2010 limits), systems capable of high simultaneous conversions of all four major pollutants, carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx) and Particulate Matter (PM), are required. Very high conversions of CO, HC and PM are achieved using catalyst-based Diesel Particulate Filter (DPF) systems, such as the Continuously Regenerating Technology, CRT{reg_sign}, system. High NOx conversions can be obtained using Selective Catalytic Reduction (SCR) systems, in which ammonia (generated from urea) is used to selectively reduce the NOx. This paper summarizes the key steps in the development of the four-way SCRT system, which comprises the CRT system followed by an SCR system. Engine bench results obtained during the development of this system are presented and discussed. However, the key to real-world emissions benefit is the actual on-road performance of such systems. It is well established that the CRT system provides very high and durable conversions of CO, HC and PM, so the focus of this current work …

Advanced Beam-Dynamics Simulation Tools for the RIA Driver Linac; Low Energy Beam Transport and Radiofrequency Quadrupole.

There has been increased interest in obtaining size distribution data during transient engine operation where both particle size and total number concentrations can change dramatically. Traditionally, the measurement of particle emissions from vehicles has been a compromise based on choosing between the conflicting needs of high time resolution or high particle size resolution for a particular measurement. Currently the most common technique for measuring submicrometer particle sizes is the Scanning Mobility Particle Sizer (SMPSTM) system. The SMPS system gives high size resolution but requires an aerosol to be stable over a long time period to make a particle size distribution measurement. A Condensation Particle Counter (CPC) is commonly used for fast time response measurements but is limited to measuring total concentration only. This paper describes a new instrument, the Engine Exhaust Particle SizerTM (EEPSTM) spectrometer, which has high time resolution and a reasonable size resolution. The EEPS was designed specifically for measuring engine exhaust and, like the SMPS system, uses a measurement based on electrical mobility. Particles entering the instrument are charged to a predictable level, then passed through an annular space where they are repelled outward by the voltage from a central column. When the particles reach electrodes on …

A description is given of the analytic and numerical work, performed from July 1955 through August 1956, so as to develop, and then study, the process of making intense proton beams, suitable for colliding beams. It is shown how this investigation led, in a most natural way, to the realization that stochasticity can arise in a simple Hamiltonian system. Furthermore, the criterion for the onset of stochasticity was understood, and carefully studied, in two different situations. The first situation was the proposed (and subsequently used) ''stacking process'' for developing an intense beam, where stochasticity occurs as additional particles are added to the intense circulating beam. The second situation occurs when one seeks to develop ''stochastic accelerators'' in which particles are accelerated (continuously) by a collection of radio frequency systems. It was in the last connection that the well-known criterion for stochasticity, resonance overlap, was obtained.

Current, state of the art natural gas engines provide the lowest emission commercial technology for use in medium heavy duty vehicles. NOx emission levels are 25 to 50% lower than state of the art diesel engines and PM levels are 90% lower than non-filter equipped diesels. Yet, in common with diesel engines, natural gas engines are challenged to become even cleaner and more efficient to meet environmental and end-user demands. Cummins Westport is developing two streams of technologies to achieve these goals for medium-heavy and heavy-heavy duty applications. For medium-heavy duty applications, lowest possible emissions are sought on SI engines without significant increase in complexity and with improvements in efficiency and BMEP. The selected path builds on the capabilities of the CWI Plus technology and recent diesel engine advances in NOx controls, providing potential to reduce emissions to 2010 values in an accelerated manner and without the use of Selective Catalytic Reduction or NOx Storage and Reduction technology. For heavy-heavy duty applications where high torque and fuel economy are of prime concern, the Westport-Cycle{trademark} technology is in field trial. This technology incorporates High Pressure Direct Injection (HPDI{trademark}) of natural gas with a diesel pilot ignition source. Both fuels are delivered …

A series of analyses were performed to assess the structural response of spent nuclear fuel dry casks subjected to various handling and on-site transfer events. The results of these analyses are being used by the Nuclear Regulatory Commission (NRC) to perform a probabilistic risk assessment (PRA). Although the PRA study is being performed for a specific nuclear plant, the PRA study is also intended to provide a framework for a general methodology that could also be applied to other dry cask systems at other nuclear plants. The dry cask system consists of a transfer cask, used for handling and moving the multi-purpose canister OLIIpC that contains the fuel, and a storage cask, used to store the MPC and fuel on a concrete pad at the site. This paper describes the analyses of the casks for two loading events. The first loading consists of dropping the transfer cask while it is lowered by a crane to a concrete floor at ground elevation. The second loading consists of dropping the storage cask while it is being transferred to the concrete storage pad outdoors. Three dimensional finite element models of the transfer cask and storage cask, containing the MPC and fuel, were utilized …

The Nuclear Power Engineering Corporation (NUPEC) of Japan has been conducting a multi-year research program to investigate the behavior of nuclear power plant piping systems under large seismic loads. The objectives of the program are: to develop a better understanding of the elasto-plastic response and ultimate strength of nuclear piping; to ascertain the seismic safety margin of current piping design codes; and to assess new piping code allowable stress rules. Under this program, NUPEC has performed a large-scale seismic proving test of a representative nuclear power plant piping system. In support of the proving test, a series of materials tests, static and dynamic piping component tests, and seismic tests of simplified piping systems have also been performed. As part of collaborative efforts between the United States and Japan on seismic issues, the US Nuclear Regulatory Commission (USNRC) and its contractor, the Brookhaven National Laboratory (BNL), are participating in this research program by performing pre-test and post-test analyses, and by evaluating the significance of the program results with regard to safety margins. This paper describes BNL's pre-test analysis to predict the elasto-plastic response for one of NUPEC's simplified piping system seismic tests. The capability to simulate the anticipated ratcheting response of …

The expected production rates at RIA imply it should be possible to collect 10-{micro}g of a one-day half-life isotope. The amount of material should be sufficient to enable direct neutron cross-section measurements for many unstable isotopes. This capability is crucial for many of the stockpile stewardship and some of the astrophysical cross-section measurements. Enabling this capability at RIA requires the ability to harvest the desired isotopes, process highly radioactive material into targets, and irradiate targets with neutrons. This paper will discuss the changes and additions to the RIA complex that are necessary in order to enable direct neutron cross-section measurements. This will include a discussion of harvesting as well as a conceptual design for a co-located experimental facility with radiochemistry capability and a variable 'mono-energetic' neutron source.

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The D0 experiment at Fermilab relies on a central Oracle database for storing all detector calibration information. Access to this data is needed by hundreds of physics applications distributed worldwide. In order to meet the demands of these applications from scarce resources, we have created a distributed system that isolates the user applications from the database facilities. This system, known as the Database Application Network (DAN) operates as the middle tier in a three tier architecture. A DAN server employs a hierarchical caching scheme and database connection management facility that limits access to the database resource. The modular design allows for caching strategies and database access components to be determined by runtime configuration. To solve scalability problems, a proxy database component allows for DAN servers to be arranged in a hierarchy. Also included is an event based monitoring system that is currently being used to collect statistics for performance analysis and problem diagnosis. DAN servers are currently implemented as a Python multithreaded program using CORBA for network communications and interface specification. The requirement details, design, and implementation of DAN are discussed along with operational experience and future plans.

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We report the results of a blind search for flavor-changing neutral current (FCNC), lepton-flavor violating, and lepton-number violating decays of D{sup +}, D{sub s}{sup +}, and D{sup 0} mesons (and their antiparticles) into 2-, 3-, and 4-body states including a lepton pair. Such decays may involve Flavor-Changing Neutral Currents, Leptoquarks, Horizontal Gauge Bosons, or Majorana Neutrinos. No evidence for any of these decays is found. Therefore, we present 90% confidence level branching-fraction upper limits, typically at the 10{sup -4} level. A total of 51 decay channels have been examined; 26 have not been previously reported and 18 are significant improvements over previous results.

OAK-B135 Density limit disruptions set an upper bound on the electron density in tokamaks and are important for future reactor-size tokamaks, which will typically need to operate at high densities to achieve ignition. In the standard picture of disruptions, a large MHD mode, or combination of MHD modes, causes a mixing of previously nested magnetic flux surfaces across much of the profile. Rapid heat and particle transport across the separatrix result, and the thermal energy of the discharge is lost along open field lines into the divertor on a millisecond time scale or faster. In this work, a density limit disruption is initiated by ramping up the density in a lower single-null discharge in the DIII-D tokamak. As in most disruptions, a large MHD precursor is observed. However, in contrast with the disruption scenario described above, it is found that the plasma thermal energy, rather than being conducted into the divertor, is dominantly lost by radiation to the main chamber walls. This has been referred to as self-mitigation of the disruption, in comparison to the intentional mitigation of localized heat loads in disruptions by the introduction of pellets or liquid or gas jets to enhance radiation. The self-mitigation effect appears …

The PowerTrap{trademark} is a non-exhaust temperature dependent system that cannot become blocked and features a controlled regeneration process independent of the vehicle's drive cycle. The system has a low direct-current power source requirement available in both 12-volt and 24-volt configurations. The system is fully programmable, fully automated and includes Euro IV requirements of operation verification. The system has gained European component-type approval and has been tested with both on- road and off-road diesel fuel up to 2000 parts per million. The device is fail-safe: in the event of a device malfunction, it cannot affect the engine's performance. Accumulated mileage testing is in excess of 640,000 miles to date. Vehicles include London-type taxicabs (Euro 1 and 2), emergency service fire engines (Euro 1, 2, and 3), inner city buses, and light-duty locomotives. Independent test results by Shell Global Solutions have consistently demonstrated 85-99 percent reduction of ultrafines across the 7-35 nanometer size range using a scanning mobility particle sizer with both ultra-low sulfur diesel and off-road high-sulfur fuel.

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