AFCI UFP, Final Technical Report DE-FC07-00AL67053 (open access)

AFCI UFP, Final Technical Report DE-FC07-00AL67053

The project ''Creating an Educational Consortium to Support the Recruitment and Retention of Expertise for the Nuclear Weapons Complex'' was also known as the Advanced Fuel Cycle Initiative (AFCI) University Fellowship Program. Since its inception, the Advanced Fuel Cycle Initiative program and its predecessor, the Advanced Accelerator Applications (AAA) program, have engaged university researchers and students in the sciences necessary to answer technical questions related to reducing high-level waste volumes, optimizing the economics and performance of Yucca Mountain, reducing the technical need for a second repository, reducing the long-term inventories of plutonium in spent fuel, and enabling the proliferation-resistant recovery of the energy contained in spent fuel. The Advanced Fuel Cycle University Fellowship Program is intended to support top students across the nation in a variety of disciplines that will be required to support transmutation research and technology development in the coming decades.
Date: February 21, 2005
Creator: Dixon, Cathy
Object Type: Report
System: The UNT Digital Library
Adaptive mesh refinement in titanium (open access)

Adaptive mesh refinement in titanium

In this paper, we evaluate Titanium's usability as a high-level parallel programming language through a case study, where we implement a subset of Chombo's functionality in Titanium. Chombo is a software package applying the Adaptive Mesh Refinement methodology to numerical Partial Differential Equations at the production level. In Chombo, the library approach is used to parallel programming (C++ and Fortran, with MPI), whereas Titanium is a Java dialect designed for high-performance scientific computing. The performance of our implementation is studied and compared with that of Chombo in solving Poisson's equation based on two grid configurations from a real application. Also provided are the counts of lines of code from both sides.
Date: January 21, 2005
Creator: Colella, Phillip & Wen, Tong
Object Type: Article
System: The UNT Digital Library
Exotic physics: search for excited and exotic electrons in the e gamma decay channel in p anti-p collisions at s**(1/2) = 1.96 tev (open access)

Exotic physics: search for excited and exotic electrons in the e gamma decay channel in p anti-p collisions at s**(1/2) = 1.96 tev

We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV with the CDF II detector. No signal above standard model expectation is seen for associated ee* production. We discuss the e* sensitivity in the parameter space of the excited electron mass M{sub e*} and the compositeness energy scale {Lambda}. In the contact interaction model, we exclude 132 GeV/c{sup 2} < M{sub e*} < 879 GeV/c{sup 2} for {Lambda} = M{sub e*} at 95% confidence level (C.L.). In the gauge-mediated model, we exclude 126 GeV/c{sup 2} < M{sub e*} < 430 GeV/c{sup 2} at 95% C.L. for the phenomenological coupling f/{Lambda} {approx} 10{sup -2} GeV{sup -1}.
Date: February 21, 2005
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
Feasibility Study for Renewable Energy Development on Tribal Lands (open access)

Feasibility Study for Renewable Energy Development on Tribal Lands

Project Objective: The Mississippi Band of Choctaw Indians (MBCI) conducted a study of the feasibility of siting a renewable energy biomass-based installation on tribal lands. The purpose of the study was to determine whether such an installation can be economically sustainable, as well as consistent with the cultural, social, and economic goals of the Tribe. Scope: To achieve the goal of the feasibility study, the following tasks were carried out: (1) Resource availability assessment--The objective of this assessment was to determine the availability of both poultry litter and wood residues for use in the proposed facility. (2) Power utilization assessment--The objective of this assessment was to determine the potential market size for power produced, the existing infrastructure for delivering power to that market, and the costs and economic returns for doing so. (3) Technology review--The objective of this review was to identify one, or more, technical options for detailed economic and technical assessment. The study considered a range of feedstock and product mixtures of poultry litter; wood residues as feedstock; and electrical power and other ancillary products as outputs. Distributed power sources was also examined. Technologies ranging from gasification to systems that produce both power and value-added chemicals were considered. …
Date: July 21, 2005
Creator: John Hendrix, Project Director; Charles Weir, Project Manager; Dr. John Plodinec, Technology Advisor & Dr. Steve Murray, Economic Advisor
Object Type: Report
System: The UNT Digital Library
An Experimental Test of Superradiance in a Single Pass Seeded FEL. (open access)

An Experimental Test of Superradiance in a Single Pass Seeded FEL.

Superradiance and nonlinear evolution of a FEL pulse in a single-pass FEL were experimentally demonstrated at the National Synchrotron Light Source (NSLS) Source Development Laboratory (SDL). The experiment was performed using a 1.5 ps high-brightness electron beam and a 100fs Ti:Sapphire seed laser. The seed laser and electron beam interact in the 10 meter long NISUS undulator with a period of 3.89 cm. The FEL spectrum, energy and pulse length along the undulator were measured. FEL saturation was observed, and gain of more the 200 (relative to seed laser) was measured. Both FEL spectrum widening and pulse length shortening were observed; FEL pulses as short as 65 fs FWHM were measured. The superradiance and nonlinear evolution were also simulated using the numerical code GENESIS1.3 yielding good agreement with the experimental results.
Date: August 21, 2005
Creator: Watanabe, T.; Liu, D.; Murphy, J. B.; Rose, J.; Shaftan, T.; Tsang, T. et al.
Object Type: Article
System: The UNT Digital Library
Ffag Accelerator Proton Driver for Neutrino Factory. (open access)

Ffag Accelerator Proton Driver for Neutrino Factory.

This paper is the summary of a conceptual study of a Proton Driver for Neutrino Factory based on the use of a Fixed-Field Alternating-Gradient (FFAG) Accelerator. The required proton energy range for an optimum neutrino production is 5 to 12 GeV. This can be accomplished with a group of three concentric rings each with 807 m circumference [1]. FFAG Accelerators [2] have the capability to accelerate charged particles over a large momentum range ({+-}30-50%) and the feature of constant bending and focusing fields. Particles can be accelerated very fast at the rate given by the accelerating field of RF cavities placed in proper locations between magnets. The performance of FFAG accelerators is to be placed between that of Super-Conducting Linear Accelerators (SCL), with which they share the fast acceleration rate, and Rapid-Cycling Synchrotrons (RCS), as they allow the beam to re-circulate over fewer revolutions. Brookhaven National Laboratory is involved in the study of feasibility of FFAG Accelerators to accelerate intense beams of protons in the GeV energy range for a variety of applications the most important of which is the Upgrade of the Alternating Gradient Synchrotron (AGS) with a new FFAG injector [3] accelerating from 400 MeV to 1.5 GeV. …
Date: June 21, 2005
Creator: Ruggiero, A.
Object Type: Article
System: The UNT Digital Library
Final Report, DE-FG02-92ER14261, Pore Scale Geometric and Fluid Distribution Analysis (open access)

Final Report, DE-FG02-92ER14261, Pore Scale Geometric and Fluid Distribution Analysis

The elucidation of the relationship between pore scale structure and fluid flow in porous media is a fundamental problem of long standing interest. Incomplete characterization of medium properties continues to be a limiting factor in accurate field scale simulations. The accomplishments of this grant have kept us at the forefront in investigating the applicability of X-ray computed microtomography (XCMT) as a tool for contributing to the understanding of this relationship. Specific accomplishments have been achieved in four areas: - development of numerical algorithms (largely in the field of computational geometry) to provide automated recognition of and measurements on features of interest in the pore space. These algorithms have been embodied in a software package, 3DMA-Rock. - application of these algorithms to extensive studies of the pore space of sandstones. - application of these algorithms to studies of fluid (oil/water) partitioning in the pore space of Berea sandstone and polyethylene models. - technology transfer.
Date: January 21, 2005
Creator: Lindquist, W. Brent
Object Type: Report
System: The UNT Digital Library
Experimental Characterization of Seeded FEL Amplifier at the NSLS SDL. (open access)

Experimental Characterization of Seeded FEL Amplifier at the NSLS SDL.

Experimental characterization of a near-IR FEL amplifier at the NSLS SDL is presented in this report. SASE was observed from 0.8-1 {micro}m with 5 orders of magnitude gain. We have experimentally demonstrated saturation of a laser seeded FEL amplifier and control of the FEL output by the seed laser. Nonlinear harmonics have also been explored. The FEL pulse length for the first three harmonics was experimentally characterized and the increase of the FEL pulse length with harmonic number was observed for the first time. Computer simulation confirmed that the observed wide spectrum of the laser seeded FEL is due to the positive chirp of the seed laser.
Date: August 21, 2005
Creator: Watanabe, T.; Liu, D.; Murphy, J. B.; Rose, J.; Shaftan, T.; Tsang, T. et al.
Object Type: Article
System: The UNT Digital Library
Stability and Dynamics of Spatio-Temporal Structures (open access)

Stability and Dynamics of Spatio-Temporal Structures

This document constitutes the final report for the grant. It provides a complete list of publications and presentations that arose from the project as well as a brief description of the highlights of the research results. The research funded by this grant has provided insights into the spontaneous formation of structures of increasing complexity in systems driven far from thermodynamic equilibrium. A classic example of such a system is thermally driven convection in a horizontal fluid layer. Highlights of the research are: (1) explanation of the localized traveling wave pulses observed in binary-mixture convection, (2) explanation of the localized waves in electroconvection, (3) introduction of a new diagnostics for spatially and temporally chaotic states, which is based on the statistics of defect trajectories, (4) prediction of complex states in thermally driven convection in rotating systems. Additional contributions provided insight into the localization mechanism for oscillons, the prediction of a new localization mechanism for traveling waves based on a resonant periodic forcing, and an analysis of the stability of quasi-periodic patterns.
Date: October 21, 2005
Creator: Riecke, Hermann
Object Type: Text
System: The UNT Digital Library
ACTIVE CATHODES FOR SUPER-HIGH POWER DENSITY SOLID OXIDE FUEL CELLS THROUGH SPACE CHARGE EFFECTS (open access)

ACTIVE CATHODES FOR SUPER-HIGH POWER DENSITY SOLID OXIDE FUEL CELLS THROUGH SPACE CHARGE EFFECTS

This report summarizes the work done during the eleventh quarter of the project. Conductivity relaxation experiments were conducted on porous La{sub 0.5}Sr{sub 0.5}CoO{sub (3-{delta})} (LSC50) samples over a temperature range from 350 to 750 C, and over an oxygen partial pressure, p{sub O{sub 2}}, switch between 0.04 and 0.06 atm in order to determine the surface exchange coefficient, k{sub chem}. The normalized conductivity data could be fitted to a first order kinetic equation. The time constant decreased with decreasing temperature between {approx}750 and {approx}450 C, but sharply increased with decreasing temperature between 450 and 350 C. The corresponding k{sub chem} was estimated using three models: (a) A porous body model wherein it is assumed that the kinetics of surface exchange is the slowest. (b) Solution to the diffusion equation assuming the particles can be approximated as spheres. (c) Solution to the diffusion equation assuming the particles can be approximated as cylinders. The values of k{sub chem} obtained from the three models were in good agreement. In all cases, it was observed that k{sub chem} increases with decreasing temperature between 750 and 450 C, but below 450 C, it sharply decreases with further decrease in temperature.
Date: September 21, 2005
Creator: Virkar, Anil V.
Object Type: Report
System: The UNT Digital Library
Thin Wall Cast Iron: Phase II (open access)

Thin Wall Cast Iron: Phase II

The development of thin-wall technology allows the designers of energy consuming equipment to select the most appropriate material based on cost/material properties considerations, and not solely on density. The technology developed in this research project will permit the designers working for the automotive industry to make a better informed choice between competing materials and thin wall cast iron, thus decreasing the overall cost of the automobile.
Date: July 21, 2005
Creator: Stefanescu, Doru M.
Object Type: Report
System: The UNT Digital Library
Final Report - The Xanthophyll Cycle (open access)

Final Report - The Xanthophyll Cycle

The xanthophyll cycle is a ubiquitous activity in higher plants. A major function of the cycle is to protect the photosynthetic system from the potentially damaging effects of high light by dissipating excess energy that might otherwise damage the photosynthetic apparatus harmlessly as heat by a process termed non-photochemical quenching (NFQ). This research focused on investigating the dynamics of the relationship between PsbS, subunit PSII protein required for NPQ, and zeaxanthin by perturbing the natural relationship of these components by overexpression of PsbS, violaxanthin de-epoxidase (VDE), and PsbS-VDE in tobacco. The effects of these treatments showed that the relationship between NPQ and zeaxanthin formation is more complex than previously indicated from studies carried out under high light. It is postulated that the xanthophyll cycle functions as a type of signal-transduction system within the thylakoid membrane. Recent studies in model lipid systems demonstrated that zeaxanthin exerts feedback inhibition on violaxanthin de-epoxidase. This feedback inhibition is consistent with the lipid phase functioning as a modulating factor in the dynamics of the cycle's operation. While this research and those in other laboratories have defined both the biochemistry and molecular mechanism of the cycle's operation, especially for violaxanthin de-epoxidase, there is yet insufficient knowledge …
Date: April 21, 2005
Creator: Yamamato, Harry
Object Type: Report
System: The UNT Digital Library
Detection of RF Perturbations Using an Ion Beam Diagnostic (open access)

Detection of RF Perturbations Using an Ion Beam Diagnostic

A Heavy Ion Beam Probe, HIBP, has been installed on a helicon plasma device. The objective was to measure plasma fluctuations at the 13.55MHz RF frequency. This offers a unique challenge for the HIBP, because the transit time of the probing ion is long compared to the fluctuations of interest. For previous HIBPs, the transit time has been short compared to the period of the fluctuations which permits one to assume that the magnetic and electric fields are static. Modeling has shown that the diagnostic will still accurately measure the average potential. The fluctuating potential was to be detected but the absolute magnitude is difficult to determine with signal from a single point. However, modeling indicates multipoint measurements will allow one to resolve the absolute fluctuation magnitude. Work supported by DOE Grant No. DE-FG02-99ER5452985 During the funding of this grant, a helicon plasma discharge device was built and operated. A Heavy Ion Beam Probe primary system was installed and operated. A primary beam detector was installed and primary beam was detected both with and without plasma. Attempts were made to detect secondary ions using the primary beam detector, without success. Given the lack of a detectable signal, the energy analyzer …
Date: September 21, 2005
Creator: Schoch, P.; Connor, K. & Si, J.
Object Type: Report
System: The UNT Digital Library
Towards a New Class of Mesoporous Materials for Applications in Petroleum Refining (open access)

Towards a New Class of Mesoporous Materials for Applications in Petroleum Refining

This project focuses on the synthesis of mesoporous aluminophosphates, silicates and aluminosilicates as catalysts for applications in the conversion of large petroleum feedstock compounds to useful middle distillates and naphtha transportation fuels. Summarized herein is our research progress from September 1, 2003, to August 31, 2004. In previous reports it was demonstrated that mesoporous aluminophosphates with neutral framework (containing Al, P and O) could be synthesized, but their thermal stabilities were limited. In general, the materials' pore structure collapsed when calcined at 500-550 C in air or extracted in ethanol/HCl mixture to remove the surfactants, which were used as synthesis templates. New methods to improve the thermal stability of the materials needed to be explored. It was conceived that by adding divalent metals cations, such as Mg and Co, not only that the acid sites would be created by balancing the negatively charged framework (balanced by H{sup +}), but the thermal stability of the materials would be improved. In addition, methods to facilitate the interaction of hydrocarbon substrates with acid sites within the mesoporous are also needed. One concept towards improving this was to incorporate organic functional groups within or attached to the otherwise purely inorganic aluminophosphate (containing Co or …
Date: March 21, 2005
Creator: Ingram, Conrad & Mitchell, Mark
Object Type: Report
System: The UNT Digital Library
Final Technical Report on "Metabolic Engineering for Heavy Metal and Actinide Removal" (open access)

Final Technical Report on "Metabolic Engineering for Heavy Metal and Actinide Removal"

None
Date: November 21, 2005
Creator: Keasling, Jay D.
Object Type: Report
System: The UNT Digital Library
Stabilizing And Packaging Pu Materials Per 3013 At SRS (open access)

Stabilizing And Packaging Pu Materials Per 3013 At SRS

The Savannah River Site (SRS) began packaging Pu metals into 3013 containers in April, 2003 and oxides in October, 2003. A total of 919 outer 3013 containers were made in the FB-Line at SRS when stabilization and packaging was completed in January, 2005. Experiences, lessons learned, and an overview of packaging activities are presented.
Date: January 21, 2005
Creator: Hensel, Steve J. & McNew, R. T.
Object Type: Article
System: The UNT Digital Library
Financing the growth of energy efficiency service industry inShanghai (open access)

Financing the growth of energy efficiency service industry inShanghai

None
Date: March 21, 2005
Creator: Lin, Jiang; Gilligan, Donald & Zhao, Yinghua
Object Type: Report
System: The UNT Digital Library
LNG SAFETY RESEARCH: FEM3A MODEL DEVELOPMENT (open access)

LNG SAFETY RESEARCH: FEM3A MODEL DEVELOPMENT

This quarterly report for DE-FG26-04NT42030 covers a period from October 1, 2004 to December 31, 2004. On December 9, 2004 a meeting was held in Morgantown to rescope the LNG safety modeling project such that the work would complement the DOE's efforts relative to the development of the intended LNG-Fluent model. It was noted and discussed at the December 9th meeting that the fundamental research being performed on surface to cloud heat transfer and low wind speed issues will be relevant to the development of the DOE LNG/Fluent Model. In general, it was decided that all research to be performed from December 9th through the remainder of the contract is to be focused on the development of the DOE LNG/Fluent model. In addition, all GTI activities for dissemination and transfer of FEM3A will cease and dissemination activities will focus on the new DOE LNG/Fluent model. The proposed new scope of work is presented in section 4 of this report. The work reported in the present document relates to the original scope of work which was in effect during the reporting period. The future work will be re-scoped to meet the requirements of the new scope of work. During the report …
Date: February 21, 2005
Creator: Havens, Jerry & Salehi, Iraj A.
Object Type: Report
System: The UNT Digital Library
Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs (open access)

Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are …
Date: August 21, 2005
Creator: Paulsson, Bjorn N.P.
Object Type: Report
System: The UNT Digital Library
INCORPORATION OF PENTAVALENT NEPTUNIUM INTO URANYL PHASES THAT MAY FORM AS ALTERATION PRODUCTS OF SPENT NUCLEAR FUEL (open access)

INCORPORATION OF PENTAVALENT NEPTUNIUM INTO URANYL PHASES THAT MAY FORM AS ALTERATION PRODUCTS OF SPENT NUCLEAR FUEL

Laboratory-scale simulations and studies of natural analogues have shown that alteration of spent nuclear fuel in a moist, oxidizing environment results in the formation of a variety of uranyl phases. Neptunium-237 has a half-life of 2.14 million years, and the pentavalent oxidation state is soluble in groundwater. Release of Np-237 from spent nuclear fuel in a geological repository may significantly impact the long-term performance of such a repository. Incorporation of Np, in the pentavalent oxidation state, into uranyl phases by substitution for hexavalent U is likely because of the similarity of the coordination environments of these two cations, but a charge-balance mechanism is required for substitution. A preliminary study has shown incorporation of pentavalent Np into powders of the uranyl silicate uranophane, and Na-compreignacite, a uranyl oxyhydrate [1]. Using synthesis experiments under mild hydrothermal conditions, we are examining the incorporation of pentavalent Np into selected uranyl oxyhydrates and silicates as a function of temperature and the pH of the mother solution. Analyses of powders of these uranyl phases has demonstrated both temperature and pH dependences for incorporation. Experiments are underway directed at the synthesis of single crystals of uranyl phases in the presence of 500-750 ppm pentavalent Np. The intent …
Date: June 21, 2005
Creator: NA
Object Type: Report
System: The UNT Digital Library
Solid Sorbents for Removal of Carbon Dioxide from Gas Streams at Low Temperatures (open access)

Solid Sorbents for Removal of Carbon Dioxide from Gas Streams at Low Temperatures

New low-cost CO2 sorbents are provided that can be used in large-scale gas-solid processes. A new method is provided for making these sorbents that involves treating substrates with an amine and/or an ether so that the amine and/or ether comprise at least 50 wt. percent of the sorbent. The sorbent acts by capturing compounds contained in gaseous fluids via chemisorption and/or physisorption between the unit layers of the substrate's lattice where the polar amine liquids and solids and/or polar ether liquids and solids are located. The method eliminates the need for high surface area supports and polymeric materials for the preparation of CO2 capture systems, and provides sorbents with absorption capabilities that are independent of the sorbents' surface areas. The sorbents can be regenerated by heating at temperatures in excess of 35 degrees C.
Date: June 21, 2005
Creator: Sirwardane, Ranjani V.
Object Type: Patent
System: The UNT Digital Library
Radiation Spectrum Statistics in a High-Gain Free-Electron Laser at 266nm. (open access)

Radiation Spectrum Statistics in a High-Gain Free-Electron Laser at 266nm.

High Gain Harmonic Generation FEL is in operations at the DUV-FEL facility (BNL). During HGHG FEL characterization we have measured a set of data demonstrating basic properties of the FEL radiation and compared them with analytic calculations [1]. This paper describes continuation of characterization of the HGHG FEL radiation output, based on the spectral measurements. We discuss analysis of an experiment at which the tunability concept of a seeded FEL with a fixed seed wavelength has been verified [2]. During the experiment we recorded about 200 radiation spectra corresponding to different energy chirps in the electron beam. We have analyzed this set of spectral data to obtain statistical properties of HGHG radiation. Correlations and trends in the radiation spectrum at 266 nm have been observed and studied.
Date: August 21, 2005
Creator: Staftan, T.; Sheehy, B.; Loos, H.; Yu, L. H.; Murphy, J. B.; Krinsky, S. et al.
Object Type: Article
System: The UNT Digital Library
VACUUM WINDOW DESIGN FOR HIGH-POWER LASERS. (open access)

VACUUM WINDOW DESIGN FOR HIGH-POWER LASERS.

One of the problems in the high-power lasers design is in outcoupling of a powerful laser beam out of a vacuum volume into atmosphere. Usually the laser device is located inside a vacuum tank. The laser radiation is transported to the outside world through the transparent vacuum window. While considered transparent, some of the light passing through the glass is absorbed and converted to heat. For most applications, these properties are academic curiosities; however, in multi-kilowatt lasers, the heat becomes significant and can lead to a failure. The absorbed power can result in thermal stress, reduction of light transmission and, consequently, window damage. Modern optical technology has developed different types of glass (Silica, BK7, diamond, etc.) that have high thermal conductivity and damage threshold. However, for kilo- and megawatt lasers the issue still remains open. In this paper we present a solution that may relieve the heat load on the output window. We discuss advantages and issues of this particular window design.
Date: April 21, 2005
Creator: SHAFTAN, T.
Object Type: Article
System: The UNT Digital Library
MULTIFUNCTIONAL (NOx/CO/O2) SOLID-STATE SENSORS FOR COAL COMBUSTION CONTROL (open access)

MULTIFUNCTIONAL (NOx/CO/O2) SOLID-STATE SENSORS FOR COAL COMBUSTION CONTROL

Sensing properties of a La{sub 2}CuO{sub 4}- and WO{sub 3}-based potentiometric NO{sub x} sensor were investigated both in N{sub 2} and in a simulated exhaust gas. We performed temperature programmed reaction (TPR) and desorption (TPD) experiments to determine the reaction and adsorption characteristics of O{sub 2}, NO{sub x}, CO, CO{sub 2}, and their mixtures on the electrodes, and related the results to sensor performance. The relative responses of the La{sub 2}CuO{sub 4}-based sensor under varied concentrations of NO, NO{sub 2}, CO, CO{sub 2} and O{sub 2} were studied. The results showed a very high sensitivity to CO and NO{sub 2} at 450 C in 3% O{sub 2}, whereas the response to O{sub 2} and CO{sub 2} gases was negligible. The NO response at 400-500 C agreed with the NO adsorption behavior. The high NO{sub 2} sensitivity at 450 C was probably related to heterogeneous catalytic activity of La{sub 2}CuO{sub 4}. The adsorption of NO was not affected by the change of O{sub 2} concentration and thus the sensor showed selective detection of NO over O{sub 2}. However, the NO sensitivity was strongly influenced by the existence of CO, H{sub 2}O, NO{sub 2}, and CO{sub 2}, as the adsorption behavior of …
Date: March 21, 2005
Creator: Wachsman, Eric D.
Object Type: Report
System: The UNT Digital Library