The Chemistry of the Thermal DeNOx Process: A Review of the Technology's Possible Application to control of NOx from Diesel Engines (open access)

The Chemistry of the Thermal DeNOx Process: A Review of the Technology's Possible Application to control of NOx from Diesel Engines

This paper presents a review of the Thermal DeNOx process with respect to its application to control of NOx emissions from diesel engines. The chemistry of the process is discussed first in empirical and then theoretical terms. Based on this discussion the possibilities of applying the process to controlling NOx emissions from diesel engines is considered. Two options are examined, modifying the requirements of the chemistry of the Thermal DeNOx process to suit the conditions provided by diesel engines and modifying the engines to provide the conditions required by the process chemistry. While the former examination did not reveal any promising opportunities, the latter did. Turbocharged diesel engine systems in which the turbocharger is a net producer of power seem capable of providing the conditions necessary for NOx reduction via the Thermal DeNOx reaction.
Date: August 5, 2001
Creator: Lyon, Richard
Object Type: Article
System: The UNT Digital Library
Mechanical design and engineering of the 3.9 GHZ, 3rd harmonic SRF system at Fermilab (open access)

Mechanical design and engineering of the 3.9 GHZ, 3rd harmonic SRF system at Fermilab

The mechanical development of the 3.9 GHz, 3rd Harmonic SRF System is summarized to include: the development of a full scale copper prototype cavity structure; the design of the niobium 3 cell and niobium 9 cell structures; the design of the helium vessel and cryostat; the HOM coupler design; and a preliminary look at the main coupler design. The manufacturing processes for forming, rolling, and e-beam welding the HOM coupler, cavity cells, and end tubes are also described. Due to the exotic materials and manufacturing processes used in this type of device, a cost estimate for the material and fabrication is provided. The 3rd harmonic design is organized via a web-based data management approach.
Date: August 5, 2004
Creator: al., Don Mitchell et
Object Type: Article
System: The UNT Digital Library
Status of the Control System on the National Spherical Torus Experiment (NSTX) (open access)

Status of the Control System on the National Spherical Torus Experiment (NSTX)

In 2003, the NSTX plasma control system was used for plasma shape control using real-time equilibrium reconstruction (using the rtEFIT code - J. Ferron, et al., Nucl. Fusion 38 1055 (1998)). rtEFIT is now in routine use for plasma boundary control [D. A. Gates, et al., submitted to Nuclear Fusion (2005)]. More recently, the system has been upgraded to support feedback control of the resistive wall mode (RWM). This paper describes the hardware and software improvements that were made in support of these physics requirements. The real-time data acquisition system now acquires 352 channels of data at 5kHz for each NSTX plasma discharge. The latency for the data acquisition, which uses the FPDP (Front Panel Data Port) protocol, is measured to be {approx}8 microseconds. A Stand-Alone digitizer (SAD), designed at PPPL, along with an FPDP Input multiplexing module (FIMM) allows for simple modular upgrades. An interface module was built to interface between the FPDP output of the NSTX control system and the legacy Power Conversion link (PCLINK) used for communicating with the PPPL power supplies (first used for TFTR). Additionally a module has been built for communicating with the switching power amplifiers (SPA) recently installed on NSTX. In addition to …
Date: August 5, 2005
Creator: Gates, D. A.; Ferron, J. R.; Bell, M.; Gibney, T.; Johnson, R.; Marsala, R. J. et al.
Object Type: Report
System: The UNT Digital Library
Software Systems: Consequence versus Functionality (open access)

Software Systems: Consequence versus Functionality

The purpose of this panel is to present different perspectives and opinions regarding the issues surrounding why software should or shouldn't be entrusted with critical (high consequence) functionality.
Date: August 5, 1999
Creator: Berg, Ray & Winter, Victor L.
Object Type: Article
System: The UNT Digital Library
Photoconductive Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers (open access)

Photoconductive Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers

High gain photoconductive semiconductor switches (PCSS) are being used to produce high power electromagnetic pulses foc (1) compact, repetitive accelerators, (2) ultra-wide band impulse sources, (3) precision gas switch triggers, (4) optically-activated firesets, and (5) high power optical pulse generation and control. High power, sub-nanosecond optical pulses are used for active optical sensors such as compact optical radars and range-gated hallistic imaging systems. Following a brief introduction to high gain PCSS and its general applications, this paper will focus on PCSS for optical pulse generation and control. PCSS technology can be employed in three distinct approaches to optical pulse generation and control: (1) short pulse carrier injection to induce gain-switching in semiconductor lasers, (2) electro-optical Q-switching, and (3) optically activated Q-switching. The most significant PCSS issues for these applications are switch rise time, jitter, and longevity. This paper will describe both the requirements of these applications and the most recent results from PCSS technology. Experiments to understand and expand the limitations of high gain PCSS will also be described.
Date: August 5, 1999
Creator: Denison, Gary J.; Helgeson, Wesley D.; Hjalmarson, Harold P.; Loubriel, Guillermo M.; Mar, Alan; O'Malley, Martin W. et al.
Object Type: Article
System: The UNT Digital Library
Geotechnical Perspectives on the Waste Isolation Pilot Plant (WIPP) (open access)

Geotechnical Perspectives on the Waste Isolation Pilot Plant (WIPP)

The Waste Isolation Pilot Plant (WIPP) is the first nuclear waste repository certified by the United States Environmental Protection Agency. Success in regulatory compliance resulted from an excellent natural setting for such a repository, a facility with multiple, redundant safety systems, and from a rigorous, transparent scientific and technical evaluation. The WIPP story, which has evolved over the past 25 years, has generated a library of publications and analyses. Details of the multifaceted program are contained in the cited references. Selected geotechnical highlights prove the eminent suitability of the WIPP to serve its congressionally mandated purpose.
Date: August 5, 1999
Creator: Francke, Chris T.; Hansen, Frank D.; Knowles, M. Kathyn; Patchet, Stanley J. & Rempe, Norbert T.
Object Type: Article
System: The UNT Digital Library
High Performance Diesel Fueled Cabin Heater (open access)

High Performance Diesel Fueled Cabin Heater

Recent DOE-OHVT studies show that diesel emissions and fuel consumption can be greatly reduced at truck stops by switching from engine idle to auxiliary-fired heaters. Brookhaven National Laboratory (BNL) has studied high performance diesel burner designs that address the shortcomings of current low fire-rate burners. Initial test results suggest a real opportunity for the development of a truly advanced truck heating system. The BNL approach is to use a low pressure, air-atomized burner derived form burner designs used commonly in gas turbine combustors. This paper reviews the design and test results of the BNL diesel fueled cabin heater. The burner design is covered by U.S. Patent 6,102,687 and was issued to U.S. DOE on August 15, 2000.The development of several novel oil burner applications based on low-pressure air atomization is described. The atomizer used is a pre-filming, air blast nozzle of the type commonly used in gas turbine combustion. The air pressure used can b e as low as 1300 Pa and such pressure can be easily achieved with a fan. Advantages over conventional, pressure-atomized nozzles include ability to operate at low input rates without very small passages and much lower fuel pressure requirements. At very low firing rates the …
Date: August 5, 2001
Creator: Butcher, Tom
Object Type: Article
System: The UNT Digital Library
OVERVIEW OF EMERGING CLEAN DIESEL ENGINE TECHNOLOGY (open access)

OVERVIEW OF EMERGING CLEAN DIESEL ENGINE TECHNOLOGY

Diesel engines are the most realistic technology to achieve a major improvement in fuel economy in the next decade. In the US light truck market, i.e. Sport Utility Vehicles , pick-up trucks and mini-vans, diesel engines can more than double the fuel economy of similarly rated spark ignition (SI) gasoline engines currently in these vehicles. These new diesel engines are comparable to the SI engines in noise levels and 0 to 60 mph acceleration. They no longer have the traditional ''diesel smell.'' And the new diesel engines will provide roughly twice the service life. This is very significant for resale value which could more than offset the initial premium cost of the diesel engine over that of the SI gasoline engine. So why are we not seeing more diesel engine powered personal vehicles in the U.S.? The European auto fleet is comprised of a little over 30 percent diesel engine powered vehicles while current sales are about 50 percent diesel. In France, over 70 percent of the luxury class cars i.e. Mercedes ''S'' Class, BMW 700 series etc., are sold with the diesel engine option selected. Diesel powered BMW's are winning auto races in Germany. These are a typical of …
Date: August 5, 2001
Creator: Fairbanks, John
Object Type: Article
System: The UNT Digital Library
Development of the third harmonic SC cavity at Fermilab (open access)

Development of the third harmonic SC cavity at Fermilab

The third harmonic 3.9 GHz superconducting cavity was recently proposed by DESY for a new generation of high brightness photo-injector (TTF photoinjector-2) to compensate nonlinear distortion of the longitudinal phase space due to RF curvature of the 1.3 GHz TESLA cavities [1,2]. Installation of the 3rd harmonic cavity will allow us to generate ultra-short (<50 {micro}m rms) highly charged electron bunches with an extremely small transverse normalized emittance (<1 {micro}m). This is required to support a new generation of linear colliders, free electron lasers and synchrotron radiation sources. In this paper we present the current status of the 3rd harmonic cavity being developed at Fermilab. We discuss the design procedure, the building and testing of the copper and niobium half-cells and components, the design of input and HOM couplers.
Date: August 5, 2004
Creator: al., Nikolay Solyak et
Object Type: Article
System: The UNT Digital Library
Regulation of Development and Nitrogen Fixation in Anabaena (open access)

Regulation of Development and Nitrogen Fixation in Anabaena

The nitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 is being used as a simple model of microbial development and pattern formation in a multicellular prokaryotic organism. Anabaena reduces atmospheric nitrogen to ammonia in highly specialized, terminally differentiated cells called heterocysts. Anabaena is an important model system because of the multicellular growth pattern, the suspected antiquity of heterocyst development, and the contribution of fixed nitrogen to the environment. We are especially interested in understanding the molecular signaling pathways and genetic regulation that control heterocyst development. In the presence of an external source of reduced nitrogen, the differentiation of heterocysts is inhibited. When Anabaena is grown on dinitrogen, a one-dimensional developmental pattern of single heterocysts separated by approximately ten vegetative cells is established to form a multicellular organism composed of two interdependent cell types. The goal of this project is to understand the signaling and regulatory pathways that commit a vegetative cell to terminally differentiate into a nitrogen-fixing heterocyst. Several genes identified by us and by others were chosen as entry points into the regulatory network. Our research, which was initially focused on transcriptional regulation by group 2 sigma factors, was expanded to include group 3 sigma factors and their regulators …
Date: August 5, 2004
Creator: Golden, James W.
Object Type: Report
System: The UNT Digital Library
Strontium-90 Liquid Concentration Solubility Correlation in the Hanford Tank Waste Operations Simulator (open access)

Strontium-90 Liquid Concentration Solubility Correlation in the Hanford Tank Waste Operations Simulator

A new correlation was developed to estimate the concentration of strontium-90 in a waste solution based on total organic carbon. This correlation replaces the strontium-90 wash factors, and when applied in the Hanford Tank Waste Operations Simulator, significantly reduced the estimated quantity of strontium-90 in the delivered low-activity waste feed. This is thought to be a more realistic estimate of strontium-90 than using the wash-factor method.
Date: August 5, 2004
Creator: Hohl, T. H.; Place, D. E. & Wittman, R. S.
Object Type: Report
System: The UNT Digital Library
''CPT Theorem'' for Accelerators (open access)

''CPT Theorem'' for Accelerators

In this paper we attempt to reveal common features in evolution of various colliders' luminosity over commissioning periods. A simplified formula, ''CPT theorem'' or CP = T, is proposed which relates the time needed for commissioning T, the ''complexity'' of the machine C and performance increase goal P.
Date: August 5, 2004
Creator: Shiltsev, Vladimir
Object Type: Article
System: The UNT Digital Library
National Spherical Torus Experiment Real Time Plasma Control Data Acquisition Hardware (open access)

National Spherical Torus Experiment Real Time Plasma Control Data Acquisition Hardware

The National Spherical Torus Experiment (NSTX) is currently providing researchers data on low aspect-ratio toroidal plasmas. NSTX's Plasma Control System adjusts the firing angles of thyristor rectifier power supplies, in real time, to control plasma position, shape and density. A Data Acquisition system comprised of off-the-shelf and custom hardware provides the magnetic diagnostics data required in calculating firing angles. This VERSAmodule Eurocard (VME) bus-based system utilizes Front Panel Data Port (FPDP) for high-speed data transfer. Data coming from physically different locations is referenced to several different ground potentials necessitating the need for a custom FPDP multiplexer. This paper discusses the data acquisition system configuration, the in-house designed 4-to-1 FPDP Input Multiplexing Module (FIMM), and future expansion plans.
Date: August 5, 2002
Creator: Marsala, R. J. & Schneider, J.
Object Type: Report
System: The UNT Digital Library
VE-Suite: Coupling Visualization and Computational Environments to Support on-the-fly Engineering Design (open access)

VE-Suite: Coupling Visualization and Computational Environments to Support on-the-fly Engineering Design

CFD (Computational Fluid Dynamics) is a widely used technique in engineering design field. It uses mathematical methods to simulate and predict flow characteristics in a certain physical space. Since the numerical result of CFD computation is very hard to understand, VR (virtual reality) and data visualization techniques are introduced into CFD post-processing to improve the understandability and functionality of CFD computation. In many cases CFD datasets are very large (multi-gigabytes), and more and more interactions between user and the datasets are required. For the traditional VR application, the limitation of computing power is a major factor to prevent visualizing large dataset effectively. This thesis presents a new system designing to speed up the traditional VR application by using parallel computing and distributed computing, and the idea of using hand held device to enhance the interaction between a user and VR CFD application as well. Techniques in different research areas including scientific visualization, parallel computing, distributed computing and graphical user interface designing are used in the development of the final system. As the result, the new system can flexibly be built on heterogeneous computing environment, dramatically shorten the computation time.
Date: August 5, 2003
Creator: Li, Song
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Notice of construction work in tank farm waste transfer pit 241-UX-154 double-contained receiver tank (open access)

Notice of construction work in tank farm waste transfer pit 241-UX-154 double-contained receiver tank

The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions & Defense Waste Section as a notice of construction (NOC) in accordance with Washington Administrative Code (WAC) 246-247, Radiation Protection - Air Emissions. WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A,'' Appendix A (WAC 246-247-110) lists the requirements that must be addressed. Additionally, the following description, attachments, and references are provided to the U.S. Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40 Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide less than 0.1 millirem/year total effective dose equivalent to the hypothetical offsite maximally exposed individual, and commencement is needed within a short time. Therefore, this application also is intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in …
Date: August 5, 1999
Creator: Hill, J. S.
Object Type: Report
System: The UNT Digital Library
Results and Commissioning Issues From an Automated Demand Response Pilot (open access)

Results and Commissioning Issues From an Automated Demand Response Pilot

This paper describes a research project to develop and test Automated Demand Response hardware and software technology in large facilities. We describe the overall project and some of the commissioning and system design problems that took place. Demand Response (DR) is a set of activities to reduce or shift electricity use to improve the electric grid reliability purposes, manage electricity costs, and ensure that customers receive signals that encourage load reduction during times when the electric grid is near its capacity. There were a number of specific commissioning challenges in conducting this test including software compatibility, incorrect time zones, IT and EMCS failures, and hardware issues. The knowledge needed for this type of system commissioning combines knowledge of building controls with network management and knowledge of emerging information technologies.
Date: August 5, 2004
Creator: Piette, Mary Ann; Watson, Dave; Sezgen, Osman & Motegi, Naoya
Object Type: Article
System: The UNT Digital Library
Breakdown During High-Field Bias-Temperature Stress (open access)

Breakdown During High-Field Bias-Temperature Stress

Measurements of dielectric breakdown during high-field electrical stress are typically performed at or near room temperature via constant voltage or current stress methods. In this summary they explore whether useful information might also be obtained by performing current measurements during a temperature ramp at high electric field.
Date: August 5, 1999
Creator: Fleetwood, D. M.; Krisch, K. S. & Sexton, F. W.
Object Type: Article
System: The UNT Digital Library
A search for di-lepton signatures from minimal low energy supergravity in {bar p}p collisions at {radical}s 1.8 = TeV (open access)

A search for di-lepton signatures from minimal low energy supergravity in {bar p}p collisions at {radical}s 1.8 = TeV

We report on a search for supersymmetry using the DO detector. The 1994-96 data sample of {radical}s = 1:8 TeV {bar p}p collisions was analyzed for events containing two leptons (e or {mu}), two or more jets, and missing transverse energy. Assuming minimal supergravity, with free parameters m{sub 0}, m{sub 1/2} and tan {beta}, various thresholds were employed to optimize the search. No excess of events was observed. We present exclusion contours in the (m{sub 0}, m{sub 1/2}) plane for tan {beta} = 2-6.
Date: August 5, 1999
Creator: II, Richard J. Genik
Object Type: Article
System: The UNT Digital Library
241-Z-361 Sludge Characterization Sampling and Analysis Plan (open access)

241-Z-361 Sludge Characterization Sampling and Analysis Plan

This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.
Date: August 5, 1999
Creator: BANNING, D.L.
Object Type: Report
System: The UNT Digital Library
Long-Term Cyclic Oxidation Behavior of Wrought Commercial Alloys at High Temperatures (open access)

Long-Term Cyclic Oxidation Behavior of Wrought Commercial Alloys at High Temperatures

The oxidation resistance of a high-temperature alloy is dependent upon sustaining the formation of a protective scale, which is strongly related to the alloying composition and the oxidation condition. The protective oxide scale only provides a finite period of oxidation resistance owing to its eventual breakdown, which is especially accelerated under thermal cycling conditions. This current study focuses on the long-term cyclic oxidation behavior of a number of commercial wrought alloys. The alloys studied were Fe- and Ni-based, containing different levels of minor elements, such as Si, Al, Mn, and Ti. Oxidation testing was conducted at 1000 and 1100 C in still air under both isothermal and thermal cycling conditions (1-day and 7-days). The specific aspects studied were the oxidation behavior of chromia-forming alloys that are used extensively in industry. The current study analyzed the effects of alloying elements, especially the effect of minor element Si, on cyclic oxidation resistance. The behavior of oxide scale growth, scale spallation, subsurface changes, and chromium interdiffusion in the alloy were analyzed in detail. A novel model was developed in the current study to predict the life-time during cyclic oxidation by simulating oxidation kinetics and chromium interdiffusion in the subsurface of chromia-forming alloys.
Date: August 5, 2003
Creator: Li, Bingtao
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Miniaturized Analytical Platforms From Nanoparticle Components: Studies in the Construction, Characterization, and High-Throughput Usage of These Novel Architectures (open access)

Miniaturized Analytical Platforms From Nanoparticle Components: Studies in the Construction, Characterization, and High-Throughput Usage of These Novel Architectures

The scientific community has recently experienced an overall effort to reduce the physical size of many experimental components to the nanometer size range. This size is unique as the characteristics of this regime involve aspects of pure physics, biology, and chemistry. One extensively studied example of a nanometer sized experimental component, which acts as a junction between these three principle scientific theologies, is deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). These biopolymers not only contain the biological genetic guide to code for the production of life-sustaining materials, but are also being probed by physicists as a means to create electrical circuits and furthermore as controllable architectural and sensor motifs in the chemical disciplines. Possibly the most common nano-sized component between these sciences are nanoparticles composed of a variety of materials. The cross discipline employment of nanoparticles is evident from the vast amount of literature that has been produced from each of the individual communities within the last decade. Along these cross-discipline lines, this dissertation examines the use of several different types of nanoparticles with a wide array of surface chemistries to understand their adsorption properties and to construct unique miniaturized analytical and immunoassay platforms. This introduction will act as a …
Date: August 5, 2003
Creator: Pris, Andrew David
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Very High Resolution Simulation of Compressible Turbulence on the IBM-SP System (open access)

Very High Resolution Simulation of Compressible Turbulence on the IBM-SP System

Understanding turbulence and mix in compressible flows is of fundamental importance to real-world applications such as chemical combustion and supernova evolution. The ability to run in three dimensions and at very high resolution is required for the simulation to accurately represent the interaction of the various length scales, and consequently, the reactivity of the intermixing species. Toward this end, we have carried out a very high resolution (over 8 billion zones) 3-D simulation of the Richtmyer-Meshkov instability and turbulent mixing on the IBM Sustained Stewardship TeraOp (SST) system, developed under the auspices of the Department of Energy (DOE) Accelerated Strategic Computing Initiative (ASCI) and located at Lawrence Livermore National Laboratory. We have also undertaken an even higher resolution proof-of-principle calculation (over 24 billion zones) on 5832 processors of the IBM, which executed for over an hour at a sustained rate of 1.05 Tflop/s, as well as a short calculation with a modified algorithm that achieved a sustained rate of 1.18 Tflop/s. The full production scientific simulation, using a further modified algorithm, ran for 27,000 timesteps in slightly over a week of n-all time using 3840 processors of the IBM system, clocking a sustained throughput of roughly 0.6 teraflop per second. …
Date: August 5, 1999
Creator: Mirin, A. A.; Cohen, R. H.; Curtis, B. C.; Dannevik, W. P.; Dimits, A. M.; Duchaineau, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Wave Driven Fast Ion Loss in the National Spherical Torus Experiment (open access)

Wave Driven Fast Ion Loss in the National Spherical Torus Experiment

The study of fast ion instabilities in conventional aspect ratio tokamaks is motivated in large part by their potential to negatively impact the ignition threshold in fusion reactors by causing fast ion losses. Spherical tokamak's (ST), with intrinsically low magnetic fields, are particularly susceptible to fast ion driven instabilities. The 3.5 MeV alpha's from the D-T [deuterium-tritium] fusion reaction in proposed ST reactors will have velocities much higher than the Alfven speed. The Larmor radius of the fusion alphas, normalized to the plasma size, will also be larger than for conventional aspect ratio tokamak reactors. The resulting longer wavelengths of the *AE instabilities will be more effective in driving fast ion loss. The change in magnetic topology also influences the mode structure, as in the case of the Compressional Alfven Eigenmodes (CAE) seen on NSTX.
Date: August 5, 2003
Creator: Fredrickson, E. D.; Cheng, C. Z.; Darrow, D.; Fu, G.; Gorelenkov, N. N.; Kramer, G. et al.
Object Type: Report
System: The UNT Digital Library
Preliminary modeling of moisture movement in the tuff beneath Mortandad Canyon, Los Alamos National Laboratory (open access)

Preliminary modeling of moisture movement in the tuff beneath Mortandad Canyon, Los Alamos National Laboratory

An area of upper/middle Mortandad Canyon on the Los Alamos National Laboratory is modeled in cross-section. UNSAT2, a finite element model (FEM) is used to predict moisture movement. Hydraulic characteristics of the tuff are described by van Genuchten parameters determined from laboratory tests on cores taken from a borehole within the cross-section. Material properties are distributed horizontal planar in space to cover the solution domain with required initial conditions. An estimate of seepage flux from a thin perched alluvial aquifer into the upper surface of the tuff is taken from a lumped parameter model. Moisture redistribution for a ponded boundary condition and a larger flux is investigated. A composite simulation using material properties from two separate coreholes is also evaluated.
Date: August 5, 1992
Creator: Geddis, A.M.
Object Type: Report
System: The UNT Digital Library