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GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY (open access)

GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform …
Date: August 24, 2003
Creator: Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U & Burtscher, H
System: The UNT Digital Library
The Development and on-Road Performance and Durability of the Four-Way Emission Control SCRT{Trademark} System (open access)

The Development and on-Road Performance and Durability of the Four-Way Emission Control SCRT{Trademark} System

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 …
Date: August 24, 2003
Creator: Cooper, B. J.; McDonald, A. C.; Walker, A. P. & Sanchez, M.
System: The UNT Digital Library
AN ENGINE EXHAUST PARTICLE SIZER{trademark} SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS (open access)

AN ENGINE EXHAUST PARTICLE SIZER{trademark} SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS

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 …
Date: August 24, 2003
Creator: Johnson, T: Caldow, R & Pucher, A Mirme, A Kittelson, D
System: The UNT Digital Library
STATE OF THE ART AND FUTURE DEVELOPMENTS IN NATURAL GAS ENGINE TECHNOLOGIES (open access)

STATE OF THE ART AND FUTURE DEVELOPMENTS IN NATURAL GAS ENGINE TECHNOLOGIES

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 …
Date: August 24, 2003
Creator: Dunn, M
System: The UNT Digital Library
Radioactive Waste Management on Hungary at the Turn of the Millennium II (open access)

Radioactive Waste Management on Hungary at the Turn of the Millennium II

The paper describes the challenging situation related to the radioactive waste management in Hungary. It is also discussing the legal and financial background and overviewing the developed strategy and the steps to be taken to find a reliable and safe disposal for L/ILW.
Date: February 24, 2003
Creator: Temesi, A.; Pellet, S. & Fritz, A.
System: The UNT Digital Library
Grafted polyelectrolyte membranes for lithium batteries and fuel cells (open access)

Grafted polyelectrolyte membranes for lithium batteries and fuel cells

Polyelectrolyte materials have been developed for lithium battery systems in response to the severe problems due to salt concentration gradients that occur in composite electrodes (aka membrane-electrode assemblies). Comb branch polymer architectures are described which allow for grafting of appropriate anions on to the polymer and also for cross-linking to provide for appropriate mechanical properties. The interactions of the polymers with the electrode surfaces are critical for the performance of the system and some of the structural features that influence this will be described. Parallels with the fuel cell MEA structures exist and will also be discussed.
Date: June 24, 2003
Creator: Kerr, John B.
System: The UNT Digital Library
The Secretary's Vision of the Cleanup Program (open access)

The Secretary's Vision of the Cleanup Program

This paper discusses the Secretary of Energy's vision of the cleanup program. Topics include development a new plan to swiftly clean up serious problems at sites and reduce the risks to human health, safety and the environment.
Date: February 24, 2003
Creator: Golan, Paul
System: The UNT Digital Library
Asymmetric PML for the absorption of waves. Application to mesh refinement in electromagnetic particle-in-cell plasma simulations (open access)

Asymmetric PML for the absorption of waves. Application to mesh refinement in electromagnetic particle-in-cell plasma simulations

We present an extension of the Berenger Perfectly Matched Layer with additional terms and tunable coefficients which introduce some asymmetry in the absorption rate. We show that the discretized version of the new PML offers superior absorption rates than the discretized standard PML under a plane wave analysis. Taking advantage of the high rates of absorption of the new PML, we have devised a new strategy for introducing the technique of Mesh Refinement into electromagnetic Particle-In-Cell plasma simulations. We present the details of the algorithm as well as a 2-D example of its application to laser-plasma interaction in the context of fast ignition.
Date: September 24, 2003
Creator: Vay, J. L.; Adam, J. C. & Heron, A.
System: The UNT Digital Library
Drip Irrigation Aided Phytoremediation for Removal of TCE from Groundwater (open access)

Drip Irrigation Aided Phytoremediation for Removal of TCE from Groundwater

Groundwater in D-Area at the Savannah River Site (SRS) is contaminated with trichloroethylene (TCE) and by-products resulting from discharges of this organic solvent during past disposal practices. This contaminated groundwater occurs primarily at depths of 9 meters to 15 meters below ground surface, well below the depths that are typically penetrated by plant roots. The process investigated in this study involved pumping water from the contaminated aquifer and discharging the water into overlying test plots two inches below the surface using drip irrigation. The field treatability study was conducted from 8/31/00 to 4/18/02 using six 0.08 hectare test plots, two each containing pines, cottonwoods, and no vegetation (controls). The primary objective was to determine the overall effectiveness of the process for TCE removal and to determine the principal biotic and abiotic pathways for its removal. Results demonstrated that the process provides a viable method to remove TCE-contaminated groundwater. The data clearly showed that the presence of trees reduced volatilization of TCE from the drip irrigation system to the atmosphere. Influent groundwater TCE concentrations averaging 89 mg/L were reduced to non-detectable levels (less than 5 mg/L) within the upper two feet of soil (rhizosphere).
Date: April 24, 2003
Creator: Wilde, E.W.
System: The UNT Digital Library
Wind Climate Analyses for a 61-M Tower in the Southeast (open access)

Wind Climate Analyses for a 61-M Tower in the Southeast

The Savannah River Technology Center's (SRTC) Atmospheric Technologies Group (ATG) has operated nine 61-m tower sites including the Central Climatology (CC) tower which is located near the center of the Savannah River Site (SRS) since 1985. Data from the weather instruments on this tower have provided answers to questions involving risk analyses, dose studies, forecast verifications, and wind/temperature conditions during extreme events and planned tests. Most recently, data from these towers are being used for initial and boundary conditions for computationally intensive numerical simulations using mesoscale forecasting models that are run on a three-hourly basis by ATG for SRS and the surrounding vicinity. We found that a series of wind roses based on relatively short time scales (from two weeks to one hour) were a convenient method to depict the predominant wind speeds and directions at anemometer sites in the Southeast operated by the NWS. That report also revealed some interesting spatial and temporal relationships among thirteen NWS stations in the Carolinas, Georgia, and Florida. Our study here will focus on the CC tower to show changes in the wind speed and direction distributions with height during diurnal and annual cycles. This study will concentrate on mean wind speed and …
Date: November 24, 2003
Creator: Weber, A. H.
System: The UNT Digital Library
Response of C3 and C4 plants to middle-Holocene climatic variation near the prairie-forest ecotone of Minnesota, U.S.A. (open access)

Response of C3 and C4 plants to middle-Holocene climatic variation near the prairie-forest ecotone of Minnesota, U.S.A.

Paleorecords of the middle Holocene (MH) from the North American midcontinent can offer insights into ecological responses to pervasive drought that may accompany future climatic warming. We analyzed MH sediments from West Olaf Lake (WOL) and Steel Lake (SL) in Minnesota to examine the effects of warm/dry climatic conditions on prairie-woodland ecosystems. Mineral composition and carbonate {delta}{sup 18}O were used to determine climatic variations, whereas pollen assemblages, charcoal {delta}{sup 13}C, and charcoal accumulation rates were used to reconstruct vegetation composition, C{sub 3} and C{sub 4} plant abundance, and fire. The ratio of aragonite:calcite at WOL and {delta}{sup 18}O at SL suggest that pronounced droughts occurred during the MH but that drought severity decreased with time. From charcoal {delta}{sup 13}C data we estimated that the MH abundance of C{sub 4} plants averaged 50% at WOL and 43% at SL. At WOL C{sub 4} abundance was negatively correlated with aragonite:calcite, suggesting that severe moisture deficits suppressed C{sub 4} plants in favor of weedy C{sub 3} plants (e.g., Ambrosia). As climate ameliorated C{sub 4} abundance increased (from {approx}33 to 66%) at the expense of weedy species, enhancing fuel availability and fire occurrence. In contrast, farther east at SL climate was cooler and wetter …
Date: December 24, 2003
Creator: Nelson, D. M.; Hu, F. S.; Tian, J.; Stefanova, I. & Brown, T. A.
System: The UNT Digital Library
Fall MRS 2003: Actinides Symposium (open access)

Fall MRS 2003: Actinides Symposium

{lg_bullet} The focus was on fundamental actinide science and its role. {lg_bullet} History- none except the Nuclear Waste Management Symposia {lg_bullet} Joint Sessions- none but we are open to it in the future. {lg_bullet} Tutorials- none but we are open to it in the future. {lg_bullet} 3 days: 16 Invited talks; 36 Contributed Talks; 10 Posters
Date: November 24, 2003
Creator: Tobin, James G.
System: The UNT Digital Library
Effects of Elevated Radon Levels on Kanne Tritium Monitors (open access)

Effects of Elevated Radon Levels on Kanne Tritium Monitors

The Savannah River Site has used Kanne ionization chambers since the late 1950's to monitor for airborne tritium in reactor facilities. Two Kanne monitors indicated elevated airborne tritium levels while monitoring a non-ventilated room used to store tritiated liquid moderator. Subsequent air sample analysis failed to reveal the presence of airborne tritium. It was suspected that elevated radon levels caused the Kanne monitors to falsely indicate tritium activity. Two commercially available monitoring systems were used to quantify radon levels in the storage room. Measurements performed during this evaluation found that radon caused the Kanne monitors in the storage room to falsely indicate the presence of airborne tritium. A side-by-side comparison of a filtered versus an unfiltered Kanne monitor found that a high efficiency particulate filter reduced monitor response to near background under high radon conditions. It was recommended that a high efficiency filter be installed on the dedicated storage room Kanne monitor and that the room be de-posted as an Airborne Radioactivity Area. It was also found that the Kanne monitors would detect a spill from a single drum of moderator within minutes and the dose rate due to tritium exposure at 20 hours following this spill would be 4.56 …
Date: November 24, 2003
Creator: Farrell, W. E.
System: The UNT Digital Library
Current status of MiniBooNE experiment (open access)

Current status of MiniBooNE experiment

This paper reviews the current status of the Fermilab mini-Booster neutrino experiment (MiniBooNE). The experiment began taking beam data in late August 2002. We describe the experiment, status of the beamline and detector, and show the first neutrino candidate events.
Date: March 24, 2003
Creator: Garcia, Fernanda G.
System: The UNT Digital Library
Site-specific inductive and inhibitory activities of MMP-2 and MMP-3 orchestrate mammary gland branching morphogenesis (open access)

Site-specific inductive and inhibitory activities of MMP-2 and MMP-3 orchestrate mammary gland branching morphogenesis

None
Date: September 24, 2003
Creator: Wiseman, Bryony S.; Sternlicht, Mark D.; Lund, Leif R.; Alexander, Caroline M.; Mott, Joni; Bissell, Mina J. et al.
System: The UNT Digital Library
RH-TRU Waste Characterization by Acceptable Knowledge at the Idaho National Engineering and Environmental Laboratory (open access)

RH-TRU Waste Characterization by Acceptable Knowledge at the Idaho National Engineering and Environmental Laboratory

Idaho National Engineering and Environmental Laboratory (INEEL) is conducting an effort to characterize approximately 620 drums of remote-handled (RH-) transuranic (TRU) waste currently in its inventory that were generated at the Argonne National Laboratory-East (ANL-E) Alpha Gamma Hot Cell Facility (AGHCF) between 1971 and 1995. The waste was generated at the AGHCF during the destructive examination of irradiated and unirradiated fuel pins, targets, and other materials from reactor programs at ANL-West (ANL-W) and other Department of Energy (DOE) reactors. In support of this effort, Shaw Environmental and Infrastructure (formerly IT Corporation) developed an acceptable knowledge (AK) collection and management program based on existing contact-handled (CH)-TRU waste program requirements and proposed RH-TRU waste program requirements in effect in July 2001. Consistent with Attachments B-B6 of the Waste Isolation Pilot Plant (WIPP) Hazardous Waste Facility Permit (HWFP) and th e proposed Class 3 permit modification (Attachment R [RH-WAP] of this permit), the draft AK Summary Report prepared under the AK procedure describes the waste generating process and includes determinations in the following areas based on AK: physical form (currently identified at the Waste Matrix Code level); waste stream delineation; applicability of hazardous waste numbers for hazardous waste constituents; and prohibited items. In …
Date: February 24, 2003
Creator: Schulz, Cheryl; Givens, Craig; Bhatt, Raj & Whitworth, Julia
System: The UNT Digital Library
9th Diesel Engine Emissions Reduction (DEER) Workshop 2003 (open access)

9th Diesel Engine Emissions Reduction (DEER) Workshop 2003

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.
Date: August 24, 2003
Creator: Kukla, Peter; Wright, James; Harris, Georgina; Ball, Andrew & Gu, Fengshou
System: The UNT Digital Library
Optical Properties of CdSe Nanoparticle Assemblies (open access)

Optical Properties of CdSe Nanoparticle Assemblies

We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.
Date: November 24, 2003
Creator: Huser, Thomas; Gerion, Daniele; Zaitseva, Natalia; Krol, Denise M. & Leon, F. Rafael
System: The UNT Digital Library