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Novel electrocatalytic sensors

Description: Basic principles employed for previously developed oxygen and SO{sub 2} sensors have been applied to other chemical sensor needs. Oxide electrodes used for oxygen sensors also possess novel catalytic properties that have been utilized for CO detection through the use of electrocatalysts on solid electrolyte membranes. These oxides offer the ability to catalyze reactions selectively for oxidation and/or reduction of analyte gas species. A combination of a catalytic and noncatalytic electrode deposited on a solid electrolyte was used to sense the reactive species by locally changing the oxygen concentration on the electrode surfaces. Multiple species can be sensed on a single substrate through the use of different electrocatalysts. A related concept is to control the catalytic properties of these materials by controlling the oxygen stoichiometry using an electrochemical pump. Presence of a gas species was sensed by changes in the electronic conductivity of the semiconducting electrode layer.
Date: November 1, 1996
Creator: Garzon, F. & Brosha, E.
Partner: UNT Libraries Government Documents Department

Micromachined sensor and actuator research at the Microelectronics Development Laboratory

Description: An overview of the major sensor and actuator projects using the micromachining capabilities of the Microelectronics Development Laboratory at Sandia National Laboratories is presented. Development efforts are underway for a variety of micromechanical devices and control electronics for those devices. Surface micromachining is the predominant technology under development. Pressure sensors based on silicon nitride diaphragms have been developed. Hot polysilicon filaments for calorimetric gas sensing have been developed. Accelerometers based upon high-aspect ratio surface micromachining are under development. Actuation mechanisms employing either electrostatic or steam power are being combined with a three-level active (plus an additional passive level) polysilicon surface micromachining process to couple these actuators to external devices. Results of efforts toward integration of micromechanics with the driving electronics for actuators or the amplification/signal processing electronics for sensors is also described. This effort includes a tungsten metallization process to allow the CMOS electronics to withstand high-temperature micromechanical processing.
Date: December 1994
Creator: Smith, J. H.; Barron, C. C.; Fleming, J. G.; Montague, S.; Rodriguez, J. L.; Smith, B. K. et al.
Partner: UNT Libraries Government Documents Department

Tank 241-BY-107 headspace gas and vapor characterization results for samples collected in March 1994 and October 1994

Description: Significant changes have been made to all of the original vapor characterization reports. This report documents specific headspace gas and vapor characterization results for all vapor sampling events to date. In addition, changes have been made to the original vapor reports to qualify the data based on quality assurance issues associated with the performing laboratories.
Date: September 1, 1995
Creator: Huckaby, J.L. & Bratzel, D.R.
Partner: UNT Libraries Government Documents Department

Chemometric Classification of Unknown Vapors by Conversion of Sensor Array Pattern Vectors to Vapor Descriptors: Extension from Mass-Transducing Sensors To Volume-Transducing Sensors

Description: A new chemometric method was recently described for classifying unknowns by transforming the vector containing the responses from a multivariate detector to a vector containing descriptors of the detected analyte (Grate et al. 1999). This approach was derived for sensor arrays where each sensor's signal is proportional to the amount of vapor sorbed by a polymer on the sensor surface. In this case, the response is proportional to the partition coefficient, K, and the concentration of the vapor in the gas phase, Cv, where K is the ratio of the concentration of vapor in the sorbent polymer phase, Cs, to Cv.
Date: June 28, 2001
Creator: Grate, Jay W
Partner: UNT Libraries Government Documents Department

Retained gas sampler interim safety assessment

Description: This safety assessment addresses the proposed action to install, operate, and remove a Retained Gas Sampler (RGS) in Tank 101-SY at Hanford. Purpose of the RGS is to help characterize the gas species retained in the tank waste; the information will be used to refine models that predict the gas-producing behavior of the waste tank. The RGS will take samples of the tank from top to bottom; these samples will be analyzed for gas constituents. The proposed action is required as part of an evaluation of mitigation concepts for eliminating episodic gas releases that result in high hydrogen concentrations in the tank dome space.
Date: January 13, 1995
Creator: Pasamehmetoglu, K.O.; Miller, W.O.; Unal, C. & Fujita, R.K.
Partner: UNT Libraries Government Documents Department

Gas Composition Transients in the Cold Vacuum Drying (CVD) Facility

Description: The purpose of this document is to evaluate selected problems involving the prediction of transient gas compositions during Cold Vacuum Drying operations. The problems were evaluated to answer specific design questions. The document is formatted as a topical report with each section representing a specific problem solution. The problem solutions are reported in the calculation format specified in HNF-1613, Rev. 0, EP 7.6.
Date: May 10, 2000
Creator: PACKER, M.J.
Partner: UNT Libraries Government Documents Department

Enhanced Gas Analysis for Diagnostics and Surveillance (EGADS): Contamination-free sampling and analysis

Description: Providing uncontaminated weapon internal atmosphere samples and measuring their dew points is of paramount importance for enhanced surveillance and accelerated aging. The authors are developing and integrating four types of gas sampling systems for use throughout the weapons complex. They are utilizing tools to extract time/age information from the gas analysis of weapon internal atmospheres.
Date: October 1, 1997
Creator: Maestas, L.M.; Guilinger, T.R. & Kelly, M.J.
Partner: UNT Libraries Government Documents Department

Chamber leakage effects on measured gas concentrations during contained demilitarization tests at NTS X-Tunnel

Description: A series of contained explosive detonation and propellant burn experiments was conducted during 1996 and 1997 using a specially constructed, large, underground chamber located in the X-tunnel complex at Area 25 of the Nevada Test Site (NTS).
Date: November 1, 1999
Creator: Shadix, Christopher R. & Lipkin, Joel
Partner: UNT Libraries Government Documents Department

Tank 241-U-104 headspace gas and vapor characterization results from samples collected on July 16, 1996

Description: This report presents the results from analyses of samples taken from the headspace of waste storage tank 241-U-104 (Tank U-104) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and analysis plan. None of the flammable constituents were present at concentrations above the analytical instrument detection limits. Total headspace flammability was estimated to be <0.108% of the lower flammability limit. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in a table. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0.
Date: August 1, 1997
Creator: Pool, K. H.; Evans, J. C.; Hayes, J. C.; Mitroshkov, A. V.; Edwards, J. A.; Julya, J. L. et al.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-B-102 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-102. This document presents sampling data resulting from the April 18, 1996 sampling of SST 241-B-102. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media. The team, consisting of Sampling and Mobile Laboratories (SML) and Special Analytical Studies (SAS) personnel, used the vapor sampling system (VSS) to collect representative samples of the air, gases, and vapors from the headspace of SST 241-B-102 with sorbent traps and SUMMA canisters.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-B-105 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-105. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the July 30, 1996 sampling of SST 241-B-105. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-B-202 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-202. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the July 18, 1996 sampling of SST 241-B-202. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 5, 1997
Creator: Caprio, G.S.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-BX-102 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-BX-102. This document presents In Situ vapor Sampling System (ISVS) data resulting from the July 31, 1996 sampling of SST 241-BX-102. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-BX-110 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-BX-110. This document presents sampling data resulting from the April 30, 1996 sampling of SST 241-BX-110. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-C-107 using the vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-C-107. This document presents sampling data resulting from the March 26, 1996 sampling of SST 241-C-107. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory which supplied and analyzed the sample media. The team collected representative headspace samples using the In Situ Vapor Sampling System (ISVS).
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-C-201 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-C-201. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the June 19, 1996 sampling of SST 241-C-201. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-C-202 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-C-202. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the June 25, 1996 sampling of SST 241-C-202. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 8, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department

Vapor and gas sampling of single-shell tank 241-C-204 using the in situ vapor sampling system

Description: The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-C-204. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the July 2, 1996 sampling of SST 241-C-204. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.
Date: August 5, 1997
Creator: Lockrem, L.L.
Partner: UNT Libraries Government Documents Department