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Influence of sample composition on aerosol organic and black carbon determinations

Description: In this paper we present results on characterization of filter-collected redwood (Sequoia sempevirens)-needle and eucalyptus smoke particles by thermal, optical, and solvent extraction methods. Our results demonstrate that organic and black carbon concentrations determined by thermal and optical methods are not only method dependent, but also critically influenced by the overall chemical composition of the samples. These conclusions are supported by the following: (1) the organic fraction of biomass smoke particles analyzed includes a component, ranging in concentration from about 6-20% of total carbon or from 16-30% of organic carbon, that is relatively non-volatile and has a combustion temperature close to that of black carbon; (2) presence of K or Na in biomass smoke samples lowers the combustion temperatures of this organic component and of black carbon, making their combustion properties indistinguishable; (3) about 20% of total organic material is nonvolatile when heated to 550{degrees}C in an inert atmosphere. Consequently, thermal methods that rely on a specific temperature to separate organic from black carbon may either underestimate or overestimate the black and organic carbon concentrations, depending on the amounts of Na and K and on the composition and concentration of organic material present in a sample. These analytical uncertainties and, under some conditions, absorption by organic material may contribute to the variability of empirically derived proportionality between light transmission through filter deposits and black carbon concentrations.
Date: July 1, 1995
Creator: Novakov, T. & Corrigan, C.E.
Partner: UNT Libraries Government Documents Department

A novel optical scattering collection system for particulate monitoring applications

Description: Light collecting systems often require radically different optical surfaces than those commonly found in optical imaging systems. An optical particulate monitor must probe a volume in emission stacks to obtain a good statistical distribution of suspended particles. However, ideal imaging systems map object planes into conjugate image planes and can probe only small volumes. The authors describe the design, fabrication and performance of a novel optical scattering collection system that exploits precision-engineered reflective conical surfaces (axicons) in a telescopic arrangement that maps a line in object space onto the detector plane in image space. Such non-spherical surfaces are nearly impossible to fabricate using traditional methods, but can readily be made using the deterministic method of single-point diamond turning. In addition to complex optical surfaces, single-point diamond turning also makes possible the precision engineering of reference surfaces useful for built-in alignment of multiple surfaces and rapid assembly of the finished system.
Date: May 1, 1996
Creator: Bernacki, B.E.; Miller, A.C. Jr. & Nuspliger, R.J.
Partner: UNT Libraries Government Documents Department

The new ozone monitor. Final report

Description: This report describes the development of an invention for measuring the concentration of ozone by measuring the heat evolved when the ozone is catalyzed and converted back to oxygen. This ozone monitor evolved through a number of prototype as described in the final report. The final instrument is accurate, reliable and can be installed as a part of a control system. This instrument can be built and calibrated for any necessary specific ozone concentration range. This instrument uses inexpensive parts and would be simple to maintain. the manufacturing cost is less than any equally reliable and accurate ozone monitor presently available. The advantage this system has is that the ozone is directly measured as the temperature of the catalyst. It does not need UV lamps (which continually degrade in use and have a variable life) or use any chemistry where a material is continuously used up. This new ozone monitor directly measures the heat that is generated from the ozone as it converts back into oxygen as the gas mixture flows through the catalyst. The catalyst has theocratically an infinite life. It can clog if the system it is installed in, is dusty. But in systems that produce ozone, it is important that the gas is clean. Under normal clean gas conditions this instrument will give long term service free monitoring.
Date: September 20, 1994
Creator: Karlson, E.L.
Partner: UNT Libraries Government Documents Department

Calculation of SY tank annulus continuous air monitor readings after postulated leak scenarios

Description: The objective of this work was to determine whether or not a continuous air monitor (CAM) monitoring the annulus of one of the SY Tanks would be expected to alarm after three postulated leak scenarios. Using data and references provided by Lockheed Martin`s Tank Farm personnel, estimated CAM readings were calculated at specific times after the postulated scenarios might have occurred. Potential CAM readings above background at different times were calculated for the following leak scenarios: Leak rate of 0.01 gal/min; Leak rate of 0.03 gal/min (best estimate of the maximum probable leak rate from a single-shell tank); and Leak of 73 gal (equivalent to a {1/4}-in. leak on the floor of the annulus). The equation used to make the calculations along with descriptions and/or explanations of the terms are included, as is a list of the assumptions and/or values used for the calculations.
Date: August 1, 1998
Creator: Kenoyer, J.L.
Partner: UNT Libraries Government Documents Department

Development and calibration of an on-line aerosol monitor for PHEBUS test FPT1

Description: An on-line aerosol monitor (OLAM2) has been developed and tested for PHEBUS test FPT1. OLAM2 utilizes new detachable fiber optic cables and sapphire light pipes for light transmission between the OLAM and the electronics. This light transmission system was tested and found to provide better signal-to-noise performance than was achieved with the continuous fibers used for test FPT0. An additional advantage of the detachable fiber/light pipe system is ease of installation. Aerosol testing (OLAM calibration) was performed in order to verify adequate signal-to-noise performance of the new fiber optic system over the specified operating conditions and to check the quantitative light attenuation measurements against theoretical predictions. Results of the testing indicated that light extinction measurements obtained during Phebus tests could be used to estimate aerosol volume concentrations, if diamond window fouling can be avoided. OLAM2 was also subjected to a proof pressure test and a long-term thermal stability test. These tests verified the mechanical and thermal integrity of the OLAM within design specifications. Long-term output signal stability was also verified with the system maintained at design temperature and half-design pressure.
Date: October 1, 1994
Creator: O`Brien, J. E.; Carmack, W. J.; Sprenger, M. H.; Thurston, G. C. & Hunt, J. L.
Partner: UNT Libraries Government Documents Department

Development of a Real-Time Beryllium Air Monitor Utilizing Microwave Induced Plasma Spectroscopy (MIPAES)

Description: This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) Program Development project at the Los Alamos National laboratory (LANL). The focus of this development has been an innovative beryllium air monitor for on-site' real-time continuous monitoring which overcomes limitations of the previous techniques for beryllium monitoring. A bench-top instrument has been set up and the performance of the instrument has been tested based on a solution aerosol. The sensitivity obtained with the instrument is sufficient to ensure workers can respond at airborne levels well below current exposure regulations. With this versatile, real-time monitor, worker exposure can be greatly reduced.
Date: July 16, 1999
Creator: Abeln, S.; Duan, Y.-a.; Olivares, J.A.; Koby, M. & Scopsick, R.C.
Partner: UNT Libraries Government Documents Department

A continuous sampling air-ICP for metals emission monitoring

Description: An air-inductively coupled plasma (air-ICP) system has been developed for continuous sampling and monitoring of metals as a continuous emission monitor (CEM). The plasma is contained in a metal enclosure to allow reduced-pressure operation. The enclosure and plasma are operated at a pressure slightly less than atmospheric using a Roots blower, so that sample gas is continuously drawn into the plasma. A Teflon sampling chamber, equipped with a sampling pump, is connected to the stack that is to be monitored to isokinetically sample gas from the exhaust line and introduce the sample into the air-ICP. Optical emission from metals in the sampled gas stream is detected and monitored using an acousto-optic tunable filter (AOTF)--echelle spectrometer system. A description of the continuous sampling air-ICP system is given, along with some preliminary laboratory data for continuous monitoring of metals.
Date: September 19, 1999
Creator: Baldwin, D.P.; Zamzow, D.S.; Eckels, D.E. & Miller, G.P.
Partner: UNT Libraries Government Documents Department

Performance testing of Eberline Alpha 6 and Alpha 6A continuous air monitors

Description: Eberline Alpha 6 and Alpha 6A continuous air monitors (CAMs) were tested against the performance criteria of the International Electrotechnical Commission standard 761-6, ``Equipment for Continuously Monitoring Radioactivity in Gaseous Effluents, Part 6: Specific Requirements for Transuranic Aerosol Effluent Monitors``, and against ANSI N42.17B, ``Performance Specification Health Physics Instrumentation--Occupational Airborne Radioactivity Monitoring Instrumentation``. The performance criteria require the CAM`s response to a radioactive source to remain within a tolerance while the CAM is exposed to an external influence such as temperature, electromagnetic fields, or ionizing radiations. The CAMs complied within specified tolerances with a majority of the performance specifications. The most significant problems with CAM performance were noted during exposures to external nonionizing radiation fields (radio frequency fields). At numerous frequencies, the CAMs did not respond to radioactive material in the filter holder. At other frequencies and in some orientations, the CAMs overresponded by orders of magnitude. In addition to sensitivity to external nonionizing radiation fields, the CAMs exhibited sensitivity to electrostatic discharges.
Date: January 1, 1998
Creator: Johnson, M.L.
Partner: UNT Libraries Government Documents Department

Exhaust gas sensors

Description: The automotive industry needed a fast, reliable, under-the-hood method of determining nitrogen oxides in automobile exhaust. Several technologies were pursued concurrently. These sensing technologies were based on light absorption, electrochemical methods, and surface mass loading. The Y-12 plant was selected to study the methods based on light absorption. The first phase was defining the detailed technical objectives of the sensors--this was the role of the automobile companies. The second phase was to develop prototype sensors in the laboratories--the national laboratories. The final phase was testing of the prototype sensors by the automobile industries. This program was canceled a few months into what was to be a three-year effort.
Date: February 9, 1997
Creator: Hiller, J. & Miree, T.J.
Partner: UNT Libraries Government Documents Department

Ozone chemiluminescent detection of olefins: Potential applications for real-time measurements of natural hydrocarbon emissions

Description: A chemiluminescence analyzer has been constructed that takes advantage of the temperature dependence of the ozone-hydrocarbon reaction. When operated at a temperature of 170 C, the analyzer functions as a total nonmethane hydrocarbon analyzer with sensitivities 10--1,000 times better than a conventional FID. However, with operation at varying temperatures, the chemiluminescent signal reflects the differences in rates of reaction of the hydrocarbons with ozone. Preliminary studies at room temperature indicated that the relative rates of reaction of isoprene, {alpha}-pinene, {beta}-pinene, and limonene with ozone correlated with the observed chemiluminescence signal. When hydrocarbons are grouped in classes of similar structure, their rates of reaction with electrophilic atmospheric oxidants (e.g., OH, O{sub 3}, NO{sub 3}) can be correlated with each other. By varying the temperature of the reaction chamber, the chemiluminescence analyzer can be tuned to more reactive classes of hydrocarbons. Therefore, the chemiluminescence analyzer has the ability to determine atmospheric hydrocarbon concentrations as a function of class and will also provide a measure of the atmospheric reactivity of the hydrocarbons.
Date: October 1, 1997
Creator: Marley, N.A.; Gaffney, J.S. & Cunningham, M.M.
Partner: UNT Libraries Government Documents Department

Real Time Air Monitoring Using Open-Path FTIR

Description: Over the last several years there has been renewed interest in the use of open-path Fourier Transform Infrared (FTIR) spectroscopy for a variety of air monitoring applications. The intersect has been motivated by the need for new technology to address the regulator requirements of the Clean Air Act Amendment of 1990. Interest has been expressed in exploring the applications of this technology to locate fugitive-source emissions and measuring total emissions from industrial facilities.
Date: September 23, 1998
Creator: Gamiles, D.S
Partner: UNT Libraries Government Documents Department


Description: SRD tested a number of different length cavities during this past quarter. Continuous transmission was observed with cavity lengths from 65 to 12 cm. The 65 cm cavity was replaced with a 39 cm cavity for work performed during this quarter. Flue gas components were tested for background absorptions and any interference with the determination of accurate mercury concentrations. Sulfur dioxide was found to absorb fairly strongly in the region of the mercury transition, but the Cavity Ring-Down (CRD) instrument was still able to detect mercury at subparts-per-billion by volume (ppb) levels. Additional flue gases tested included H{sub 2}O, CO, CO{sub 2}, NO, NO{sub 2}. None of these flue gas constituents showed any observable absorption in the ultraviolet region near the atomic mercury transition. Work was also initiated in speciation studies. In particular mercury chloride (HgCl{sub 2}) was tested. A mercury signal was detected from a gas stream containing HgCl{sub 2}. SRD was not able to determine definitively if there exists a spectral shift great enough to separate HgCl{sub 2} from elemental mercury in these initial tests.
Date: December 31, 2002
Creator: Carter, Christopher C.
Partner: UNT Libraries Government Documents Department


Description: Science & Engineering Associates, Inc. (SEA), under contract No. DE-AC26-00NT40768, was tasked by the US Department of Energy--National Energy Technology Laboratory to develop and test a near real-time beryllium monitor for airborne and surface measurements. Recent public awareness of the health risks associated with exposure to beryllium has underscored the need for better, faster beryllium monitoring capabilities within the DOE. A near real-time beryllium monitor will offer significant improvements over the baseline monitoring technology currently in use. Whereas the baseline technology relies upon collecting an air sample on a filter and the subsequent analysis of the filter by an analytical laboratory, this effort developed a monitor that offers near real-time measurement results while work is in progress. Since the baseline typically only offers after-the-fact documentation of exposure levels, the near real-time capability provides a significant increase in worker protection. The beryllium monitor developed utilizes laser induced breakdown spectroscopy, or LIBS as the fundamental measurement technology. LIBS has been used in a variety of laboratory and field based instrumentation to provide real-time, and near-real-time elemental analysis capabilities. LIBS is an analytical technique where a pulsed high energy laser beam is focused to a point on the sample to be interrogated. The high energy density produces a small high temperature plasma plume, sometimes called a spark. The conditions within this plasma plume result in the constituent atoms becoming excited and emitting their characteristic optical emissions. The emission light is collected and routed to an optical spectrometer for quantitative spectral analysis. Each element has optical emissions, or lines, of a specific wavelength that can be used to uniquely identify that element. In this application, the intensity of the beryllium emission is used to provide a quantitative measure of the abundance of the element in the sample. The monitor can be operated in one ...
Date: December 1, 2002
Creator: Kendrick, D.T. & Saggese, Steven
Partner: UNT Libraries Government Documents Department

Availability Analysis of the Ventilation Stack CAM Interlock System

Description: Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability.
Date: January 5, 2000
Creator: YOUNG, J.
Partner: UNT Libraries Government Documents Department


Description: The first quarter of this project to develop a Cavity Ringdown Spectroscopy mercury continuous emission monitor involved acquisition and verification of the laser system to be used, initial cavity design, and initial software development for signal processing and data acquisition.
Date: January 1, 2002
Creator: Christopher C. Carter, Ph.D.
Partner: UNT Libraries Government Documents Department


Description: This quarterly report presents results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the January-March, 2002 study period. The continuous data include PM{sub 2.5} mass concentrations measured by TEOM, particle sulfate using the R&P 8400S monitor, particle size distributions measured by SMPS and APS monitors, and PM{sub 2.5} light scattering extinction coefficient as measured by nephelometer. Some instrumental issues were noted with the upgrade of the APS model 3320 are described in the report, as well as preliminary performance indications for the upgraded instrument. During the quarter preliminary data analysis and modeling studies were conducted to test the potential of the North Birmingham site data for source attribution analyses. Our initial assessment has continued to be optimistic in this regard due to the location of the site relative to several important classes of local and midrange emission sources. We anticipate that these analyses will provide good separations of the effects of major source classes and spatial source clusters, and will provide useful information relevant to PM{sub 2.5} implementation strategies.
Date: April 1, 2002
Partner: UNT Libraries Government Documents Department

Initial Development of a Continuous Emission Monitor for Dioxins

Description: Under contract DE-AC26-98FT-40370, SRI International has completed the third phase of a planned three-phase effort to develop a laboratory prototype continuous emission monitor (CEM) for dioxins and furans generated during the incineration of waste materials at DOE remediation sites. The project was initiated on July 29, 1998 with the technical effort completed in October 2001. During this research effort, SRI has made numerous improvements in our jet-REMPI instrument. These improvements have involved characterization and optimization of the molecular cooling in the gas jet, implementation of a custom-fabricated, four pulsed valve assembly, new data acquisition and display software, and preliminary development of a wavelength and mass calibration approach. We have also measured the REMPI excitation spectra of numerous organic compounds that are likely to be present in the exhaust stream of a waste incinerator. These spectra must be well characterized in the laboratory to understand any potential interferences that might arise when monitoring for dioxin and furan congeners. Our results to date continue to validate the original concept of using jet-REMPI as the detection method in a dioxin CEM. Using only commercial components with minor modifications, we have already demonstrated a detection sensitivity in the low ppt range with sufficient chemical specificity to separately detect two closely related congeners of dichlorodibenzodioxin present in a mixture. To demonstrate the utility of this methodology outside of the controlled conditions of the laboratory, we performed a series of pseudo-field experiments at the US Environmental Protection Agency's National Risk Management Research Laboratory, Research Triangle Park, NC. The instrument used for those studies was built by SRI under contract with US EPA, and was an exact duplicate of the SRI system. This duplication allowed the experiments to be conducted without transporting the SRI system to the EPA site. Using the jet-REMPI system in conjunction with a ...
Date: March 30, 2002
Creator: Coggiola, Michael J.; Oser, Harald; Faris, Gregory W. & Crosley, David R.
Partner: UNT Libraries Government Documents Department

Electrochemical sensors for volatile nitrogen compounds in air. Final report to J&N Associates, Inc. from Illinois Institute of Technology, Re: Department of Energy Phase I STTR Project DOE No. DE-FG02-99ER86090

Description: Air pollutant gases such as nitric oxide, nitrogen dioxide, nitrous acid, and peroxyacetyl nitrate are commonly encountered in urban atmospheres. They constitute a nuisance to some, and a positive danger to others with such respiratory conditions as asthma and emphysema. It is known that exposure to these gases is a function of microenvironment, but monitoring of microenvironments is presently too uneconomical to be used except in rare cases, such as ''sick buildings''. Gas sensors that are small, sensitive, selective, and inexpensive are needed to make such monitoring practical. Many sensor types have apparently reached their technological development limit, but porous-electrode amperometric gas sensors have not been thoroughly explored for low-concentration applications. We have explored amperometric gas sensors of several types for lower detection limits to a series of nitrogen gases. Evidence gathered in this study indicates that greater sensitivity will be achieved by reducing the noise level of the working electrode, rather than increasing the output signal.
Date: September 7, 2000
Creator: Stetter, Joseph R.; Penrose, William R. & Roh, Sae-Won
Partner: UNT Libraries Government Documents Department

Development of Low Maintenance, Field Ruggedized SO3 CEM

Description: A prototype semi-continuous monitor and associated particulate-free sample extraction probe have been developed for measuring the concentrations of SO{sub 3} and H{sub 2}SO{sub 4} in industrial flue gases. The monitor provides two measurements per hour for concentrations above 1 ppmv. The probe provides the capability of continuous operation while avoiding passing the sample through a layer of particulate and can be used as a probe for conventional controlled condensation measurements of SO{sub 3} and H{sub 2}SO{sub 4} emissions.
Date: July 31, 2005
Creator: Williamson, Ashley D. & McCain, Joseph D.
Partner: UNT Libraries Government Documents Department

296-B-5 Stack monitoring and sampling system annual system assessment report

Description: The B Plant Administration Manual requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 296-B-5 at B Plant. The sampling and monitoring system associated with stack 296-B-5 is functional and performing satisfactorily. This document is an annual assessment report of the systems associated with the 296-B-5 stack.
Date: February 1995
Creator: Ridge, T. M.
Partner: UNT Libraries Government Documents Department

Deployment of a Continuously Operated {mu}ChemLab

Description: A continuously operating prototype chemical weapons sensor system based on the {mu}ChemLab{trademark} technology was installed in the San Francisco International Airport in late June 2002. This prototype was assembled in a National Electric Manufacturers Association (NEMA) enclosure and controlled by a personal computer collocated with it. Data from the prototype was downloaded regularly and periodic calibration tests were performed through modem-operated control. The instrument was installed just downstream of the return air fans in the return air plenum of a high-use area of a boarding area. A CW Sentry, manufactured by Microsensor Systems, was installed alongside the {mu}ChemLab unit and results from its operation are reported elsewhere. Tests began on June 26, 2002 and concluded on October 16, 2002. This report will discuss the performance of the prototype during the continuous testing period. Over 70,000 test cycles were performed during this period. Data from this first field emplacement have indicated several areas where engineering improvements can be made for future field emplacement.
Date: May 1, 2003
Partner: UNT Libraries Government Documents Department

Measurement of the seasonal and annual variability of total column aerosol in a northeastern U.S. network

Description: A network of multi-filter rotating shadowband radiometers has operated since late 1991 in the northeastern US. The data acquired are simultaneous measurements of total and diffuse horizontal irradiances in six narrowband filtered detectors and one broadband shortwave detector. The direct normal irradiances are calculated from these measurements. These direct data are corrected for cosine response and used to calculate extraterrestrial irradiance (I{sub o}) using the Langley method of regressing the natural logarithm of direct irradiance versus air mass. With frequent determinations of I{sub o}, changes in I{sub o} caused by soiling and filter degradation, for example, can be tracked. Using these I{sub o}`s, total optical depth is calculated for every clear 30-minute period in the record. Consequently, total optical depth may be obtained on a fair number of days throughout the year. Using daily average total optical depth the authors have calculated aerosol optical depths for five wavelengths by subtracting Rayleigh scattering optical depths and Chappuis ozone absorption optical depths at each wavelength. The aerosol pattern at nearly every site is an annual cycle superimposed on a decaying stratospheric loading associated with the Mount Pinatubo volcanic eruption. An attempt is made to remove the volcanic signal using data from another site.
Date: September 1, 1994
Creator: Michalsky, J.J.; Schlemmer, J.A.; Harrison, L.C.; Berkheiser, W.E. III; Larson, N.R. & Laulainen, N.S.
Partner: UNT Libraries Government Documents Department