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1

STACK GAS REHEAT EVALUATION  

EPA Science Inventory

The report gives results of technical and economic evaluations of stack gas reheat (SGR) following wet flue gas desulfurization (FGD) for coal-fired power plants. The evaluations were based on information from literature and a survey of FGD users, vendors, and architect/engineer ...

2

FIELD EVALUATION OF AN AUTOISOKINETIC STACK PARTICULATE SAMPLING SYSTEM  

EPA Science Inventory

The performance of a prototype autoisokinetic stack particulate sampling system, designed to maintain automatically isokinetic sampling conditions, was evaluated in field tests at stationary sources. Tests were conducted to determine the operating limits and characteristics of th...

3

Stack Gas Desulfurization by Seawater in Shanghai  

Microsoft Academic Search

There are a series of advantages in use of seawater as absorbent to remove SO2 in stack gas. Use of seawater for stack gas desulfurization is the first choice method for thermal power plant located on seaside. A study on the possibility of desulfurization by seawater of the East China Sea has be done by our institute. The qualities of

D. N. Zhang; Q. Z. Chen; Y. X. Zhao; Y. Maeda; Y. Tsujino

2001-01-01

4

PROCEEDINGS: SEMINAR ON IN-STACK PARTICLE SIZING FOR PARTICULATE CONTROL DEVICE EVALUATION  

EPA Science Inventory

The proceedings document discussions during an EPA/IERL-RTP-sponsored seminar on In-stack Particle Sizing for Particulate Control Device Evaluation. The seminar, organized by IERL-RTP's Process Measurements Branch, was held at IERL-RTP in North Carolina on December 3 and 4, 1975....

5

Removal of Sulfur from Natural Gas to Reduce Particulate Matter Emission from a Turbine Engine  

NASA Astrophysics Data System (ADS)

The present work investigates the effect of natural gas fuel sulfur on particulate emissions from stationary gas turbine engines used for electricity generation. Fuel sulfur from standard line gas was scrubbed using a system of fluidized reactor beds containing a specially designed activated carbon purpose built for sulfur absorption. A sulfur injection system using sonic orifices was designed and constructed to inject methyl mercaptan into the scrubbed gas stream at varying concentrations. Using these systems, particulate emissions created by various fuel sulfur levels between 0 and 8.3 ppmv were investigated. Particulate samples were collected from a Capstone C65 microturbine generator system using a Horiba MDLT-1302TA micro dilution tunnel and analyzed using a Horiba MEXA-1370PM particulate analyzer. In addition, ambient air samples were collected to determine incoming particulate levels in the combustion air. The Capstone C65 engine air filter was also tested for particulate removal efficiency by sampling downstream of the filter. To further differentiate the particulate entering the engine in the combustion air from particulate being emitted from the exhaust stack, two high efficiency HEPA filters were installed to eliminate a large portion of incoming particulate. Variable fuel sulfur testing showed that there was a strong correlation between total particulate emission factor and fuel sulfur concentration. Using eleven variable sulfur tests, it was determined that an increase of 1 ppmv fuel sulfur will produce an increase of approximately 3.2 microg/m3 total particulate. Also, the correlation also predicted that, for this particular engine, the total particulate emission factor for zero fuel sulfur was approximately 19.1 microg/m3. With the EC and OC data removed, the correlation became 3.1 microg/m3 of sulfur particulate produced for each ppmv of fuel sulfur. The correlation also predicted that with no fuel sulfur present, 6.6 microg/m3 of particulate will be produced by sulfur passing through the engine air filter.

Spang, Brent Loren

6

Particulate hot gas stream cleanup technical issues  

SciTech Connect

The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

Pontius, D.H.; Snyder, T.R.

1999-09-30

7

Simultaneous stack-gas scrubbing and waste water treatment  

NASA Technical Reports Server (NTRS)

Simultaneous treatment of wastewater and S02-laden stack gas make both treatments more efficient and economical. According to results of preliminary tests, solution generated by stack gas scrubbing cycle reduces bacterial content of wastewater. Both processess benefit by sharing concentrations of iron.

Poradek, J. C.; Collins, D. D.

1980-01-01

8

Method for removing particulate matter from a gas stream  

DOEpatents

Particulate matter is removed from a stream of pressurized gas by directing the stream of gas upwardly through a bed of porous material, the porous bed being held in an open ended container and at least partially submerged in liquid. The passage of the gas through the porous bed sets up a circulation in the liquid which cleans the particulate matter from the bed.

Postma, Arlin K. (Benton City, WA)

1984-01-01

9

Particulate hot gas stream cleanup technical issues  

SciTech Connect

This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep testing of two Refractron 326 specimens is now in progress. Among the tasks expected to be completed this quarter are analysis of the creep data obtained thus far, microstructural analysis of Refractron 326 and Schumacher FT20, definition of bending loads on candle filters, and characterization of additional candle filters from Karhula.

NONE

1998-09-01

10

Size distribution and chemical composition of particulate matter stack emissions in and around a copper smelter  

NASA Astrophysics Data System (ADS)

This paper reports on results from a multi-sampling campaign (stack, fugitive emissions and ambient air measurements) to characterise the geochemical signature of metal and metalloid particles emitted from one of the largest Cu-smelters in the world (in Huelva, SW Spain). Exceptionally high concentrations of very fine particles (<0.33 ?m) bearing As, Cd, Pb, Cu, Bi, Zn (?>100 ?g m-3) are emitted from the Flash Smelting Furnaces, but high levels are also emitted by the other main chimney stacks, namely Refining Furnaces, Sulphuric Plant, Converters Unit, and Crushing Plant. Enhanced concentrations of the same elements are also observed in ground measurements near the industrial complex. During the sampling campaign, the presence of plumes from the Cu-smelter over the nearby city of Huelva was identified based on increased concentrations of gaseous pollutants, particulate metals and ultrafine particle numbers (PN). The results demonstrate that the Cu-smelter is an important source of inhalable toxic elements carried by fine airborne particles. The pollution abatement systems applied so far appear to be relatively ineffective in preventing metalliferous air pollution events, potentially increasing health risks to local and regional populations.

González-Castanedo, Yolanda; Moreno, Teresa; Fernández-Camacho, Rocío; Sánchez de la Campa, Ana María; Alastuey, Andrés; Querol, Xavier; de la Rosa, Jesús

2014-12-01

11

Particulate hot gas stream cleanup technical issues  

SciTech Connect

This is the eleventh in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, analyses were completed on samples obtained during a site visit to the Power Systems Development Facility (PSDF). Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. An additional analysis was performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. A manuscript and poster were prepared for presentation at the Advanced Coal-Based Power and Environmental Systems `97 Conference scheduled for July 22 - 24, 1997. A summary of recent project work covering the mechanisms responsible for ash deposit consolidation and ash bridging in APF`s collecting PFB ash was prepared and presented at FETC-MGN in early July. The material presented at that meeting is included in the manuscript prepared for the Contractor`s Conference and also in this report. Task 2 work during the past quarter included mechanical testing and microstructural examination of Schumacher FT20 and Pall 326 as- manufactured, after 540 hr in service at Karhula, and after 1166 hr in service at Karhula. Key test results showed that property degradation occurred during service at Karhula but less degradation than was seen in Schumacher F40 and Pall 442T. Creep continues to be observed in tests at 1600 `F and above and was observed at 1562 `F in service at Karhula. Microstructural evaluations of FT20 and 326 materials have shown that the behavior of these materials is controlled by the ceramic binders and that the binders are still glass limited. These results were presented in a poster session and a paper written for the Advanced Coal-Based Power and Environmental Systems `97 Conference.

NONE

1998-09-01

12

Simultaneous stack gas scrubbing wastewater purification  

NASA Technical Reports Server (NTRS)

Variations of a process for removing sulfur dioxide from stack gases and using it to treat municipal waste water are described. The once-through system lowers the pH of the scrubbing water from minor depressions to a pH of about 2.5 under certain conditions. A recycle system uses iron for catalytic oxidation of sulfurous acid to sulfuric acid allowing very large amounts of sulfur dioxide to be absorbed in a small portion of water. The partial recycle system uses municipal wastewater and iron as a scrubbing medium, followed by neutralization of the wastewater with lime to produce an iron hydroxide precipitation which, when removed, produces tertiary quality treated wastewater. The SO2 scrubber is described, test results are analyzed, and a preliminary capital cost estimate for the three processes is included.

1978-01-01

13

Influence of gas velocity on particulate fouling of exhaust gas recirculation coolers  

Microsoft Academic Search

The objective of this research is to study the influence of gas flow velocity on particulate fouling of exhaust gas recirculation (EGR) coolers. An experimental setup has been designed and constructed to simulate particulate fouling in EGR coolers in diesel engines. The setup consists of soot generator, gas\\/particle flow heater, testing section for EGR coolers and finally an exhaust system.

M. S. Abd-Elhady; T. Zornek; M. R. Malayeri; S. Balestrino; P. G. Szymkowicz; H. Müller-Steinhagen

2011-01-01

14

Particulate Hot Gas Stream Cleanup Technical Issues  

SciTech Connect

This is the fifteenth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data bank of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on May 18 to the Department of Energy / Southern Company Services Power Systems Development Facility (PSDF) and a particulate sample collected in the Westinghouse filter at Sierra Pacific Power Company?s Piñon Pine Power Project. Analysis of this Piñon Pine sample is ongoing: however, this report contains the results of analyses completed to date. Significant accomplishments were achieved on the HGCU data bank during this reporting quarter. The data bank was prepared for presentation at the Advanced Coal-Based Power and Environmental Systems ?98 Conference scheduled for July, 1998. Task 2 work during the past quarter consisted of testing two Dupont PRD-66C candle filters, one McDermott ceramic composite candle filter, one Blasch 4-270 candle filter, and one Specific Surface cordierite candle filter. Tensile and thermal expansion testing is complete and the rest of the testing is in progress. Also, some 20-inch long Dupont PRD-66C, McDermott ceramic composite, and Westinghouse Techniweave candle filters have been received for testing after their exposure to the gasification environment. One as-manufactured and one exposed element was received of each material and specimens are currently being machined from these candles.

None

1998-08-31

15

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Gas meter or flow instrumentation calibration, particulate...ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate...particulate emissions requires the use of gas meters or flow instrumentation to...

2013-07-01

16

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Gas meter or flow instrumentation calibration, particulate...ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate...particulate emissions requires the use of gas meters or flow instrumentation to...

2012-07-01

17

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2013-07-01 true Gas meter or flow instrumentation calibration, particulate...ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate...particulate emissions requires the use of gas meters or flow instrumentation to...

2014-07-01

18

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Gas meter or flow instrumentation calibration, particulate...ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate...particulate emissions requires the use of gas meters or flow instrumentation to...

2011-07-01

19

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Gas meter or flow instrumentation calibration, particulate...ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate...particulate emissions requires the use of gas meters or flow instrumentation to...

2010-07-01

20

TECHNIQUES TO MEASURE VOLUMETRIC FLOW AND PARTICULATE CONCENTRATION IN STACKS WITH CYCLONIC FLOW  

EPA Science Inventory

The study determined that an in-stack venturi can accurately measure volumetric flow in stacks with a severe cyclonic flow profile. The design requirements of the venturi are described in the report. The report also describes a low head loss, egg crate-shaped device that effectiv...

21

Engine exhaust particulate and gas phase contributions to vascular toxicity.  

PubMed

Cardiovascular health effects of near-roadway pollution appear more substantial than other sources of air pollution. The underlying cause of this phenomenon may simply be concentration-related, but the possibility remains that gases and particulate matter (PM) may physically interact and further enhance systemic vascular toxicity. To test this, we utilized a common hypercholesterolemic mouse model (Apolipoprotein E-null) exposed to mixed vehicle emission (MVE; combined gasoline and diesel exhausts) for 6?h/d?×?50?d, with additional permutations of removing PM by filtration and also removing gaseous species from PM by denudation. Several vascular bioassays, including matrix metalloproteinase-9 protein, 3-nitrotyrosine and plasma-induced vasodilatory impairments, highlighted that the whole emissions, containing both particulate and gaseous components, was collectively more potent than MVE-derived PM or gas mixtures, alone. Thus, we conclude that inhalation of fresh whole emissions induce greater systemic vascular toxicity than either the particulate or gas phase alone. These findings lend credence to the hypothesis that the near-roadway environment may have a more focused public health impact due to gas-particle interactions. PMID:24730681

Campen, Matthew; Robertson, Sarah; Lund, Amie; Lucero, Joann; McDonald, Jacob

2014-05-01

22

Feasibility of an alpha particle gas densimeter for stack sampling applications  

E-print Network

FEASIBILITY OF AN ALPHA PARTICLE GAS DENSIMETER FOR STACK SAMPLING APPLICATIONS A Thesis by RANDALL ~ JOHNSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May l983 Major Subject: Nuclear Engineering FEASIBILITY OF AN ALPHA PARTICLE GAS DENSIMETER FOR STACK SAMPLING APPLICATIONS A Thesis by RANDALL MARK JO HN SON Approved as to style and content by: Ro ert A. F3e d (Ch irman of Committee...

Johnson, Randall Mark

2012-06-07

23

Optical backscatter probe for sensing particulate in a combustion gas stream  

DOEpatents

A system for sensing particulate in a combustion gas stream is disclosed. The system transmits light into a combustion gas stream, and thereafter detects a portion of the transmitted light as scattered light in an amount corresponding to the amount of particulates in the emissions. Purge gas may be supplied adjacent the light supply and the detector to reduce particles in the emissions from coating or otherwise compromising the transmission of light into the emissions and recovery of scattered light from the emissions.

Parks, James E; Partridge, William P

2013-05-28

24

Evaluation of gas cooling for pressurized phosphoric acid fuel cell stacks  

NASA Technical Reports Server (NTRS)

Gas cooling is a more reliable, less expensive and a more simple alternative to conventional liquid cooling for heat removal from the phosphoric acid fuel cell (PAFC). The feasibility of gas cooling has already been demonstrated in atmospheric pressure stacks. This paper presents theoretical and experimental investigation of gas cooling for pressurized PAFC. Two approaches to gas cooling, Distributed Gas Cooling (DIGAS) and Separated Gas Cooling (SGC) were considered, and a theoretical comparison on the basis of cell performance indicated SGC to be superior to DIGAS. The feasibility of SGC was experimentally demonstrated by operating a 45-cell stack for 700 hours at pressure, and determining thermal response and the effect of other related parameters.

Farooque, M.; Skok, A. J.; Maru, H. C.; Kothmann, R. E.; Harry, R. W.

1983-01-01

25

Black carbon particulate matter emission factors for buoyancy-driven associated gas flares  

Microsoft Academic Search

Flaring is a technique used extensively in the oil and gas industry to burn unwanted flammable gases. Oxidation of the gas can preclude emissions of methane (a potent greenhouse gas); however, flaring creates other pollutant emissions such as particulate matter (PM) in the form of soot or black carbon (BC). Currently available PM emission factors for flares were reviewed and

James D. N. McEwen; Matthew R. Johnson

2012-01-01

26

A four-channel portable solar radiometer for measuring particulate and/or aerosol opacity and concentration of NO2 and SO2 in stack plumes  

NASA Technical Reports Server (NTRS)

Solar absorption radiometry has been investigated as a method of measuring stackplume effluents. A simple and inexpensive instrument was constructed for observing the sun at four wavelengths: 800, 600, 400, and 310 nm. Higher wavelength channels measured the effect of the particulates and NO2, and an ultraviolet channel measured the contribution of SO2 to the attenuation. Stack-plume measurements of opacity and concentration of NO2 and SO2 were in basic agreement with in-stack measurements. The major limitation on the use of the radiometer is the requirement for an accessible viewing position which allows the sun-plume-observer relationship to be attained. It was concluded that the solar radiometer offers an inexpensive method for monitoring plume effluents when the viewing position is not restricted.

Exton, R. J.; Gregory, R. W.

1976-01-01

27

DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS-FIRED COMBUSTION SYSTEMS  

SciTech Connect

In 1997, the United States Environmental Protection Agency (EPA) promulgated new National Ambient Air Quality Standards (NAAQS) for particulate matter, including for the first time particles with aerodynamic diameter smaller than 2.5 micrometers ({micro}m) referred to as PM2.5. PM2.5 in the atmosphere also contributes to reduced atmospheric visibility, which is the subject of existing rules for siting emission sources near Class 1 areas and new Regional Haze rules. There are few existing data regarding emissions and characteristics of fine aerosols from oil, gas and power generation industry combustion sources, and the information that is available is generally outdated and incomplete. Traditional stationary source air emission sampling methods tend to underestimate or overestimate the contribution of the source to ambient aerosols because they do not properly account for primary aerosol formation, which occurs after the gases leave the stack. Primary aerosol includes both filterable particles that are solid or liquid aerosols at stack temperature plus those that form as the stack gases cool through mixing and dilution processes in the plume downwind of the source. These deficiencies in the current methods can have significant impacts on regulatory decision-making. PM2.5 measurement issues were extensively reviewed by the American Petroleum Institute (API) (England et al., 1998), and it was concluded that dilution sampling techniques are more appropriate for obtaining a representative particulate matter sample from combustion systems for determining PM2.5 emission rate and chemical speciation. Dilution sampling is intended to collect aerosols including those that condense and/or react to form solid or liquid aerosols as the exhaust plume mixes and cools to near-ambient temperature immediately after the stack discharge. These techniques have been widely used in recent research studies. For example, Hildemann et al. (1994) and McDonald et al. (1998) used filtered ambient air to dilute the stack gas sample followed by 80-90 seconds residence time to allow aerosol formation and growth to stabilize prior to sample collection and analysis. More accurate and complete emissions data generated using the methods developed in this program will enable more accurate source-receptor and source apportionment analysis for PM2.5 National Ambient Air Quality Standards (NAAQS) implementation and streamline the environmental assessment of oil, gas and power production facilities. The overall goals of this program were to: (1) Develop improved dilution sampling technology and test methods for PM2.5 mass emissions and speciation measurements, and compare results obtained with dilution and traditional stationary source sampling methods. (2) Develop emission factors and speciation profiles for emissions of fine particulate matter, especially organic aerosols, for use in source-receptor and source apportionment analyses. (3) Identify and characterize PM2.5 precursor compound emissions that can be used in source-receptor and source apportionment analyses.

Glenn C. England

2004-10-20

28

Separation of particulate from flue gas of fossil fuel combustion and gasification  

Microsoft Academic Search

The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a

W. C. Yang; R. A. Newby; T. E. Lippert

1997-01-01

29

Separation of particulate from flue gas of fossil fuel combustion and gasification  

Microsoft Academic Search

The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical

Wen-Ching Yang; Richard A. Newby; Thomas E. Lippert

1997-01-01

30

Characteristics of PCDD/F congener distributions in gas/particulate phases and emissions from two municipal solid waste incinerators in Taiwan.  

PubMed

Partitioning of PCDD/F (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) congeners between gaseous and particulate phases and removal efficiencies of the existing air pollution control devices (APCDs) for PCDD/Fs at two large-scale municipal waste incinerators (MWIs) in Taiwan are evaluated via stack sampling and analysis. Two MWIs investigated are equipped with activated carbon injection (ACI) and selective catalytic reduction system (SCR) as major PCDD/F control devices, respectively. The average PCDD/F concentrations of stack gases are 2.35 and 1.49 ng/N m(3), and the international toxic equivalent quantity (TEQ) are 0.17 and 0.043 ng TEQ/N m(3) in MWI-A and MWI-B, respectively. The average removal efficiency of PCDD/Fs achieved with ACI+BF (bag filters) reaches 95% (MWI-A) while that achieved with the WS (wet scrubber)+SCR system reaches 99% (MWI-B). The results obtained on gas/particulate partitioning in flue gases indicate that particulate-phase PCDD/Fs accounted for 27.7% and 24.7% of the total PCDD/F concentrations at the outlets of cyclone (CY) and electrostatic precipitator (EP) for MWI-A and MWI-B, respectively. But the gas/particulate partitioning in flue gas after PCDD/Fs control devices is quite different in two MWIs. This study also indicates that total 2,3,7,8-substituted PCDD/F discharges are 142.3 microg TEQ/ton waste for MWI-A and 98.6 microg TEQ/ton waste for MWI-B, respectively. PMID:16084975

Chi, Kai Hsien; Chang, Moo Been; Chang-Chien, Guo Ping; Lin, Chieh

2005-07-15

31

Three-dimensional Numerical Simulation of Gas-particulate Flow around Breathing Human and Particulate Inhalation  

NASA Astrophysics Data System (ADS)

It is important to predict the environment around the breathing human because inhalation of virus (avian influenza, SARS) is recently severe worldwide problem, and air pollution caused by diesel emission particle (DEP) and asbestos attract a great deal of attention. In the present study, three-dimensional numerical simulation was carried out to predict unsteady flows around a breathing human and how suspended particulate matter (SPM, diameter˜1 ?m) reaches the human nose in inhalation and exhalation. In the calculation, we find out smaller breathing angle and the closer distance between the human nose and pollutant region are effective in the inhalation of SPM.

Shimazaki, Yasuhiro; Okubo, Masaaki; Yamamoto, Toshiaki

2006-05-01

32

EVALUATION OF STATIONARY SOURCE PARTICULATE MEASUREMENT METHODS. VOLUME III. GAS TEMPERATURE CONTROL DURING METHOD 5 SAMPLING  

EPA Science Inventory

A study was conducted to measure changes in gas temperature along the length of a Method 5 sampling train due to variations in stack gas temperature, sampling rate, filter box temperature and method for controlling the probe heating element. For each run condition, temperatures w...

33

Effect on combined cycle efficiency of stack gas temperature constraints to avoid acid corrosion  

NASA Technical Reports Server (NTRS)

To avoid condensation of sulfuric acid in the gas turbine exhaust when burning fuel oils contaning sulfur, the exhaust stack temperature and cold-end heat exchanger surfaces must be kept above the condensation temperature. Raising the exhaust stack temperature, however, results in lower combined cycle efficiency compared to that achievable by a combined cycle burning a sulfur-free fuel. The maximum difference in efficiency between the use of sulfur-free and fuels containing 0.8 percent sulfur is found to be less than one percentage point. The effect of using a ceramic thermal barrier coating (TBC) and a fuel containing sulfur is also evaluated. The combined-cycle efficiency gain using a TBC with a fuel containing sulfur compared to a sulfur-free fuel without TBC is 0.6 to 1.0 percentage points with air-cooled gas turbines and 1.6 to 1.8 percentage points with water-cooled gas turbines.

Nainiger, J. J.

1980-01-01

34

Apparatus for removal of particulate matter from gas streams  

DOEpatents

An apparatus for the removal of particulate matter from the gaseous product stream of an entrained flow coal gasifier which apparatus includes an initial screen, an intermediate screen which is aligned with the direction of flow of the gaseous product stream and a final screen transversely disposed to the flow of gaseous product and which apparatus is capable of withstanding at least a pressure differential of about 10 psi (68.95 kPa) or greater at the temperatures of the gaseous product stream.

Smith, Peyton L. (Baton Rouge, LA); Morse, John C. (Baton Rouge, LA)

2000-01-01

35

Workshop on Aerosols and Particulates from Aircraft Gas Turbine Engines  

NASA Technical Reports Server (NTRS)

This paper reviews the relationships of the programs and projects and reviews the purpose of the Engine Exhaust Trace Chemistry (EETC) Committee. The charges of the Committee are: (1) to prioritize the engine trace constituents for assessing impacts of aircraft; (2) Assess both extractive and insitu measurement techniques; and (3) Determine the best venues for performing the necessary measurements. A synopsis of evidence supporting and questions concerning the role(s) of aerosol/particulates was presented. The presentation also reviewed how sulfur oxidation kinetics interactions in the hot-section and nozzle play a role in the formation of aerosol precursors. The objective of the workshop, and its organization is reviewed.

Niedzwiecki, Richard; Dryer, Frederick L.

1999-01-01

36

Characterization of particulate matter in the hot product gas from atmospheric fluidized bed biomass gasifiers  

Microsoft Academic Search

This study compares the characteristics of particulate matter (PM) in the hot product gas from three different atmospheric fluidized bed biomass gasifiers: a bubbling fluidized bed (BFB) gasifier, a circulating fluidized bed (CFB) gasifier, and an indirect BFB gasifier (the latter integrated with a CFB boiler). All gasifiers displayed a bimodal particle mass size distribution with a fine mode in

Eva Gustafsson; Leteng Lin; Michael Strand

2011-01-01

37

Capsule report: Bahco flue-gas-desulfurization and particulate-removal system  

Microsoft Academic Search

The capsule report describes a Research-Cottrell\\/Bahco scrubber moddule for sulfur dioxide and particulate emission control located at the central heat plant of Rickenbacker Air Force Base. The report also describes flue gas desulfurization technology using any fuel, including high sulfur oil or coal. Cost-effective and environmentally-acceptable ways to burn fuel are described.

Ferb

1979-01-01

38

NOVEL CONCEPTS, METHODS AND ADVANCED TECHNOLOGY IN PARTICULATE/GAS SEPARATION  

EPA Science Inventory

This paper discusses presentations made during a symposium on novel concepts, methods, and advanced technology in particulate/gas separation. The symposium, held at the University of Notre Dame and sponsored by the National Science Foundation and the Environmental Protection Agen...

39

Predicting saturation of gas hydrates using pre-stack seismic data, Gulf of Mexico  

NASA Astrophysics Data System (ADS)

A promising method for gas hydrates exploration incorporates pre-stack seismic inversion data, elastic properties modeling, and seismic interpretation to predict saturation of gas hydrates ( Sgh). The technology can be modified slightly and used for predicting hydrate concentrations in shallow arctic locations as well. Examples from Gulf of Mexico Walker Ridge (WR) and Green Canyon (GC) protraction areas illustrate how Sgh was derived and used to support the selection of well locations to be drilled for gas hydrates in sand reservoirs by the Chevron-led Joint Industry Project (JIP) Leg II cruise in 2009. Concentrations of hydrates were estimated through the integration of seismic inversion of carefully conditioned pre-stack data, seismic stratigraphic interpretation, and shallow rock property modeling. Rock property trends were established by applying principles of rock physics and shallow sediment compaction, constrained by regional geological knowledge. No nearby sonic or density logs were available to define the elastic property trends in the zone of interest. Sgh volumes were generated by inverting pre-stack data to acoustic and shear impedance (PI and SI) volumes, and then analyzing deviations from modeled impedance trends. In order to enhance the quality of the inversion, we stress the importance of maximizing the signal to noise ratio of the offset data by conditioning seismic angle gathers prior to inversion. Seismic interpretation further plays an important role by identifying false anomalies such as hard, compact strata, which can produce apparent high Sgh values, and by identifying the more promising strata and structures for containing the hydrates. This integrated workflow presents a highly promising methodology, appropriate for the exploration of gas hydrates.

Shelander, Dianna; Dai, Jianchun; Bunge, George

2010-03-01

40

Formation of Secondary Particulate Matter by Reactions of Gas Phase Hexanal with Sulfate Aerosol Particles  

NASA Astrophysics Data System (ADS)

The formation of secondary particulate matter from the atmospheric oxidation of organic compounds can significantly contribute to the particulate burden, but the formation of organic secondary particulate matter is poorly understood. One way of producing organic secondary particulate matter is the oxidation of hydrocarbons with seven or more carbon atoms to get products with low vapor pressure. However, several recent reports suggest that relatively low molecular weight carbonyls can enter the particle phase by undergoing heterogeneous reactions. This may be a very important mechanism for the formation of organic secondary particulate matter. Atmospheric aldehydes are important carbonyls in the gas phase, which form via the oxidation of hydrocarbons emitted from anthropogenic and biogenic sources. In this poster, we report the results on particle growth by the heterogeneous reactions of hexanal. A 5 L Continuous Stirred Tank Reactor (CSTR) is set up to conduct the reactions in the presence of seed aerosol particles of deliquesced ammonia bisulfate. Hexanal is added into CSTR by syringe pump, meanwhile the concentrations of hexanal are monitored with High Pressure Liquid Chromatograph (HPLC 1050). A differential Mobility Analyzer (TSI 3071) set to an appropriate voltage is employed to obtain monodisperse aerosols, and another DMA associated with a Condensation Nuclear Counter (TSI 7610) is used to measure the secondary particle size distribution by the reaction in CSTR. This permits the sensitive determination of particle growth due to the heterogeneous reaction, very little growth occurs when hexanal added alone. Results for the simultaneous addition of hexanal and alcohols will also be presented.

Zhang, J.

2003-12-01

41

Gas and Particulate Sampling of Airborne Polycyclic Aromatic Compounds  

SciTech Connect

The denuder surfaces of the gas and particle (GAP) sampler (developed at the Atmospheric Environment Service of Environment Canada) have been modified by coating with XAD-4 resin, using techniques developed at Lawrence Berkeley National Laboratory (LBNL) for the lower capacity integrated organic vapor/particle sampler (IOVPS). The resulting high capacity integrated organic gas and particle sampler (IOGAPS) has been operated in ambient air at 16.7 L min{sup -1} for a 24-hour period in Berkeley, California, USA. Simultaneous measurements were made at the same collection rate with a conventional sampler that used a filter followed by two sorbent beds. Gas and particle partition measurements were determined for 13 polycyclic aromatic hydrocarbons (PAH) ranging from 2-ring to 6-ring species. The IOGAPS indicated a higher particle fraction of these compounds than did the conventional sampler, suggesting that the conventional sampler suffered from 'blow-off' losses from the particles collected on the filter.

Lane, D.A.; Gundel, L.A.

1995-10-01

42

Characterization of polychlorinated naphthalenes in stack gas emissions from waste incinerators.  

PubMed

Nine typical waste incinerating plants were investigated for polychlorinated naphthalene (PCN) contents in their stack gas. The incinerators investigated include those used to incinerate municipal solid, aviation, medical, and hazardous wastes including those encountered in cement kilns. PCNs were qualified and quantified by isotope dilution high resolution gas chromatography-high resolution mass spectrometry techniques. An unexpectedly high concentration of PCNs (13,000 ng Nm(-3)) was found in the stack gas emitted from one waste incinerator. The PCN concentrations ranged from 97.6 to 874 ng Nm(-3) in the other waste incinerators. The PCN profiles were dominated by lower chlorinated homologues, with mono- to tetra-CNs being the main homologues present. Furthermore, the relationships between PCNs and other unintentional persistent organic pollutants involving polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, hexachlorobenzene, and pentachlorobenzene were examined to ascertain the closeness or otherwise of their formation mechanisms. A good correlation was observed between ?PCN (tetra- to octa-CN) and ?PCDF (tetra- to octa-CDF) concentrations suggesting that a close relationship may exist between their formation mechanisms. The results would provide an improved understanding of PCN emissions from waste incinerators. PMID:23054784

Hu, Jicheng; Zheng, Minghui; Liu, Wenbin; Li, Changliang; Nie, Zhiqiang; Liu, Guorui; Zhang, Bing; Xiao, Ke; Gao, Lirong

2013-05-01

43

Trace gas and particulate emissions from biomass burning in temperate ecosystems  

NASA Technical Reports Server (NTRS)

Emissions measured from fires in graminoid wetlands, Mediterranean chaparrals, and boreal forests, suggest that such ecosystemic parameters as fuel size influence combustion emissions in ways that are broadly predictable. The degree of predictability is most noticeable when wetland fire-related results are compared with boreal forest emissions; the inorganic fraction of the particulate emissions is close in composition irrespective of the ecosystem. It is found that both aerosol and trace gas emissions are influenced by the phase of combustion.

Cofer, Wesley R., III; Levine, Joel S.; Winstead, Edward L.; Stocks, Brian J.

1991-01-01

44

Waste Gas And Particulate Control Measures For Laser Cutters In The Automotive Cloth Industry  

NASA Astrophysics Data System (ADS)

Demands for greater flexibility and accuracy in the manufacture of automobile trim parts has made single-ply laser cutting an attractive proposition. Lasers are able to cut a large variety of cloth types, from vinyls to velours. Unlike mechanically cut parts, which in the case of velours produce rough edges and dust problems, laster cutting of parts produces smooth edges, fumes and fine particulate. A detailed study of the nature of the laser effluent from a cross section of typical synthetic cloth found in an automotive trim plant was undertaken. Most samples were cut by a fast axial flow, 500 Watt, continuous wave CO2 laser. A 254 mm (10-inch) focussing optics package was used. The width of the kerf varied with the material, and values were determined at between 0.2 and 0.7 mm. Particle size distribution analysis and rates of particulate emission for each cloth were determined. Gases were collected in gas sample bags and analyzed using Fourier transform infrared analysis. Low boiling point organics were collected on activated charcoal tubes, identified on a gas chromatograph mass spectrometer, and quantified on a gas chromatograph. Inorganic contaminants were collected on filter paper and analysed on an inductively coupled plasma atomic emission spectrometer. A number of different effluent control systems were evaluated. Due to the very fine and sticky nature of the particulate, filters capable of removing particulate sizes in the 10 ?m or lower range, tend to clog rapidly. Laboratory scale models of wet scrubbers, and electrostatic precipitators were built and tested. The most effective dust and effluent gas control was given by a wet electrostatic precipitator. This system, in conjunction with a scrubber, should maintain emission levels within environmental standards.

Ball, R. D.; Kulik, B. F.; Stoncel, R. J.; Tan, S. L.

1986-11-01

45

Assessment of the Losses Due to Self Absorption by Mass Loading on Radioactive Particulate Air Stack Sample Filters  

SciTech Connect

This report discusses the effect of mass loading of a membrane filter on the self absorption of radioactive particles. A relationship between mass loading and percent loss of activity is presented. Sample filters were collected from Pacific Northwest National Laboratory (PNNL) facilities in order to analyze the current self absorption correction factor of 0.85 that is being used for both alpha and beta particles. Over an eighteen month period from February 2009 to July 2010, 116 samples were collected and analyzed from eight different building stacks in an effort coordinated by the Effluent Management group. Eleven unused filters were also randomly chosen to be analyzed in order to determine background radiation. All of these samples were collected and analyzed in order to evaluate the current correction factor being used.

Smith, Brian M.; Barnett, J. M.; Ballinger, Marcel Y.

2011-01-18

46

Utility stack opacity troubleshooting guidelines  

SciTech Connect

Stack plume visibility, otherwise defined as plume opacity, has become a concern to the utility industry. This concern stems from the fact that some coal-fired stations with operating FGD systems have been cited for opacity in excess of the New Source Performance Standards (NSPS) even though the particulate mass emissions are within regulated limits. Postulated causes for the unacceptable opacities include scrubber-generated particulate matter, condensible particulate matter such as sulfuric acid mist, fine particles penetrating the particulate control device, and/or colored gases such as nitrogen dioxide in the flue gas. It is important that the underlying cause of the plume opacity be identified to determine if it is possible to reduce plume opacity. This report presents a troubleshooting methodology developed during field tests at four utilities experiencing high stack opacities. Results from these field tests are presented as case studies to demonstrate how this methodology can be applied by a utility to determine the cause of their plume opacity. 10 refs., 18 figs., 5 tabs.

Keeth, R.J. (United Engineers and Constructors, Inc., Denver, CO (USA). Stearns-Roger Div.); Balfour, D.A.; Meserole, F.M.; Defries, T. (Radian Corp., Austin, TX (USA))

1991-03-01

47

Probing the gas content of radio galaxies through H I absorption stacking  

NASA Astrophysics Data System (ADS)

Using the Westerbork Synthesis Radio Telescope, we carried out shallow H i absorption observations of a flux-selected (S1.4 GHz > 50 mJy) sample of 93 radio active galactic nuclei (AGN), which have available SDSS (Sloan Digital Sky Survey) redshifts between 0.02 < z < 0.23. Our main goal is to study the gas properties of radio sources down to S1.4 GHz flux densities not systematically explored before using, for the first time, stacking of absorption spectra of extragalactic H i. Despite the shallow observations, we obtained a direct detection rate of ~29%, comparable with deeper studies of radio galaxies. Furthermore, detections are found at every S1.4 GHz flux level, showing that H i absorption detections are not biased toward brighter sources. The stacked profiles of detections and non-detections reveal a clear dichotomy in the presence of H i, with the 27 detections showing an average peak ? = 0.02 corresponding to N(H i) ~(7.4 ± 0.2) × 1018 (Tspin/cf) cm-2, while the 66 non-detections remain undetected upon stacking with a peak optical depth upper limit ? < 0.002 corresponding to N(H i) < (2.26 ± 0.06) × 1017 (Tspin/cf) cm-2 (using a FWHM of 62 kms-1, derived from the mean width of the detections). Separating the sample into compact and extended radio sources increases the detection rate, optical depth, and FWHM for the compact sample. The dichotomy for the stacked profiles of detections and non-detections still holds between these two groups of objects. We argue that orientation effects connected to a disk-like distribution of the H i can be partly responsible for the dichotomy that we see in our sample. However, orientation effects alone cannot explain all the observational results, and some of our galaxies must be genuinely depleted of cold gas. A fraction of the compact sources in the sample are confirmed by previous studies as likely young radio sources (compact steep spectrum and gigahertz peaked spectrum sources). These show an even higher detection rate of 55%. Along with their high integrated optical depth and wider profile, this reinforces the idea that young radio AGN are embedded in a medium that is rich in atomic gas. Part of our motivation is to probe for the presence of faint H i outflows at low optical depth using stacking. However, the stacked profiles do not reveal any significant blueshifted wing. We are currently collecting more data to investigate the presence of outflows. The results presented in this paper are particularly relevant for future surveys in two ways. The lack of bias toward bright sources is encouraging for the search for H i in sources with even lower radio fluxes planned by such surveys. The results also represent a reference point when searching for H i absorption at higher redshifts.

Geréb, K.; Morganti, R.; Oosterloo, T. A.

2014-09-01

48

Analysis of benzo(a)pyrene in airborne particulates by gas chromatography  

NASA Technical Reports Server (NTRS)

A routine method was developed to measure benzo(a)pyrene in airborne particulates. Samples were collected on a filter and the organic portion was extracted with cyclohexane. The polynuclear hydrocarbon (PNHC) fraction was separated from the aliphatics by column chromatography. An internal standard was added to the extract and a portion of it was injected into a gas chromatograph. Although the gas chromatographic method has often been reported in the literature, satisfactory separation of benzo(a)pyrene and benzo(e)pyrene has not been achieved. With the introduction of a nematic liquid crystal as the stationary phase good separation is now possible.

Luedecke, E.

1976-01-01

49

Numerical Simulation of CO and NO Emissions during Converter Off-Gas Combustion in the Cooling Stack  

Microsoft Academic Search

Oxygen converter steelmaking produces a large amount of high temperature off-gas. During pre- and post-combustion of converter off-gas in the cooling stack, CO concentration at outlet is always over emission standard, and NO emission is still paid little attention. In the paper, CO and NO emissions are investigated during converter off-gas combustion by CFD. The simulation results indicate that CO

Sen Li; Xiaolin Wei

2012-01-01

50

Quenching of Particle-Gas Combustible Mixtures Using Electric Particulate Suspension (EPS) and Dispersion Methods  

NASA Technical Reports Server (NTRS)

A cooperative study is being carried out between Iowa State University and McGill University. The new study concerns wall and particle quenching effects in particle-gas mixtures. The primary objective is to measure and interpret flame quenching distances, flammability limits, and burning velocities in particulate suspensions. A secondary objective is to measure particle slip velocities and particle velocity distribution as these influence flame propagation. Two suspension techniques will be utilized and compared: (1) electric particle suspension/EPS; and (2) flow dispersion. Microgravity tests will permit testing of larger particles and higher and more uniform dust concentrations than is possible in normal gravity.

Colver, Gerald M.; Goroshin, Samuel; Lee, John H. S.

2001-01-01

51

NONWATER QUALITY IMPACTS OF CLOSED-CYCLE COOLING SYSTEMS AND THE INTERACTION OF STACK GAS AND COOLING TOWER PLUMES  

EPA Science Inventory

The report gives results of a literature survey of the nonwater quality impacts of closed-cycle cooling systems. Following discussions of cooling tower and stack gas plumes, interactions of these plumes are considered. For cooling tower plumes, plume types, behavior, salt drift g...

52

Separation of particulate from flue gas of fossil fuel combustion and gasification  

DOEpatents

The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The flyash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured flyash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled.

Yang, Wen-Ching (Murrysville, PA); Newby, Richard A. (Pittsburgh, PA); Lippert, Thomas E. (Murrysville, PA)

1997-01-01

53

Separation of particulate from flue gas of fossil fuel combustion and gasification  

DOEpatents

The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The fly ash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured fly ash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled. 11 figs.

Yang, W.C.; Newby, R.A.; Lippert, T.E.

1997-08-05

54

SIZE DISTRIBUTIONS OF TRACE METALS IN FLUE GAS PARTICULATE FROM A PILOT-SCALE ROTARY KILN INCINERATOR  

EPA Science Inventory

The distributions of nine trace metals in flue gas particulate by particle size range were determined as part of a pilot-scale hazardous waste incineration test program. hese tests were conducted in the rotary kiln incinerator system at the U.S. EPA's Incineration Research Facili...

55

IMPACTS OF GREENHOUSE GAS AND PARTICULATE EMISSIONS FROM WOODFUEL PRODUCTION AND END-USE IN SUB-SAHARAN AFRICA  

E-print Network

IMPACTS OF GREENHOUSE GAS AND PARTICULATE EMISSIONS FROM WOODFUEL PRODUCTION AND END-USE IN SUB the atmospheric radiation budget. We use empirical studies and published emission factors to estimate with charcoal has 2-10 times the global warming effect of cooking the same meal with firewood and 5-16 times

Kammen, Daniel M.

56

SOA formation study from limonene ozonolysis in indoor environment: gas and particulate phases chemical characterization and toxicity prediction  

E-print Network

SOA formation study from limonene ozonolysis in indoor environment: gas and particulate phases chamber study, reactivity, house cleaning products, health effects 1 Introduction Limonene is widely formation from the ozonolysis of limonene as emitted from a detergent, in order to gather information

Paris-Sud XI, Université de

57

An analysis of extinction coefficients of particles and water moisture in the stack after flue gas desulfurization at a coal-fired power plant.  

PubMed

Two important factors that affect in-stack opacity--light extinction by emitted particles and that by water moisture after a flue gas desulfurization (FGD) unit--are investigated. The mass light extinction coefficients for particles and water moisture, k(p) and k(w), respectively, were determined using the Lambert-Beer law of opacity with a nonlinear least-squares regression method. The estimated k(p) and k(w) values vary from 0.199 to 0.316 m2/g and 0.000345 to 0.000426 m2/g, respectively, and the overall mean estimated values are 0.229 and 0.000397 m2/g, respectively. Although k(w) is 3 orders of magnitude smaller than k(p), experimental results show that the effect on light extinction by water moisture was comparable to that by particles because of the existence of a considerable mass of water moisture after a FGD unit. The mass light extinction coefficient was also estimated using Mie theory with measured particle size distributions and a complex refractive index of 1.5-ni for fly ash particles. The k(p) obtained using Mie theory ranges from 0.282 to 0.286 m2/g and is slightly greater than the averaged estimated k(p) of 0.229 m2/g from measured opacity. The discrepancy may be partly due to a difference in the microstructure of the fly ash from the assumption of solid spheres because the fly ash may have been formed as spheres attached with smaller particles or as hollow spheres that contained solid spheres. Previously reported values of measured k(p) obtained without considering the effects of water moisture are greater than that obtained in this study, which is reasonable because it reflects the effect of extinction by water moisture in the flue gas. Additionally, the moisture absorbed by particulate matter, corresponding to the effect of water moisture on the particulates, was clarified and found to be negligible. PMID:21874952

Tu, Wen-Fu; Lin, Jenn-Der; Wu, Yee-Lin

2011-08-01

58

Ion beam analyses of particulate matter in exhaust gas of a ship diesel engine  

NASA Astrophysics Data System (ADS)

There is an urgent need to reduce emission of the particulate matter (PM) in the exhaust gas from ship diesel engines causing various health hazards and serious environmental pollution. Usually the heavy fuel oil (HFO) for ships is of low quality, and contains various kinds of impurities. Therefore, the emission of PM along with exhaust gas from ship diesel engines is one of the most serious environmental issues. However, the PM fundamental properties are not well known. Therefore, it is important to perform elemental analysis of the PM. The HFO contains sulfur with a relatively high concentration of a few percent. It is important to make quantitative measurements of sulfur in the PM, because this element is poisonous for the human body. In the present work, PM samples were collected from exhaust gas of a test engine, and RBS and PIXE analyses were applied successfully to quantitative analysis of the PM samples. The RBS analysis enabled quantitative analysis of sulfur and carbon in the collected PM, while heavier elements such as vanadium and iron were analyzed quantitatively with the PIXE analysis. It has been found that the concentration ratio of sulfur to carbon was between 0.007 and 0.012, and did not strongly depend on the output power of the engine. The S/ C ratio is approximately equal to the original composition of the HFO used in the present work, 0.01. From the known conversion ratio 0.015 of sulfur in the HFO to sulfates, the conversion ratio of carbon in the HFO to the PM is found to be 0.01-0.02 by the RBS measurements. On the other hand, the PIXE analysis revealed a vanadium enrichment of one order of magnitude in the PM.

Furuyama, Yuichi; Fujita, Hirotsugu; Taniike, Akira; Kitamura, Akira

2011-12-01

59

Method for monitoring stack gases for uranium activity  

DOEpatents

A method for monitoring the stack gases of a purge cascade of gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases. 1 fig.

Beverly, C.R.; Ernstberger, E.G.

1985-07-03

60

Method for monitoring stack gases for uranium activity  

DOEpatents

A method for monitoring the stack gases of a purge cascade of a gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases.

Beverly, Claude R. (Paducah, KY); Ernstberger, Harold G. (Paducah, KY)

1988-01-01

61

Including impacts of particulate emissions on marine ecosystems in life cycle assessment: the case of offshore oil and gas production.  

PubMed

Life cycle assessment is increasingly used to assess the environmental performance of fossil energy systems. Two of the dominant emissions of offshore oil and gas production to the marine environment are the discharge of produced water and drilling waste. Although environmental impacts of produced water are predominantly due to chemical stressors, a major concern regarding drilling waste discharge is the potential physical impact due to particles. At present, impact indicators for particulate emissions are not yet available in life cycle assessment. Here, we develop characterization factors for 2 distinct impacts of particulate emissions: an increased turbidity zone in the water column and physical burial of benthic communities. The characterization factor for turbidity is developed analogous to characterization factors for toxic impacts, and ranges from 1.4 PAF (potentially affected fraction) · m(3) /d/kg(p) (kilogram particulate) to 7.0 x 10³ [corrected] for drilling mud particles discharged from the rig. The characterization factor for burial describes the volume of sediment that is impacted by particle deposition on the seafloor and equals 2.0 × 10(-1) PAF · m(3) /d/kg(p) for cutting particles. This characterization factor is quantified on the basis of initial deposition layer characteristics, such as height and surface area, the initial benthic response, and the recovery rate. We assessed the relevance of including particulate emissions in an impact assessment of offshore oil and gas production. Accordingly, the total impact on the water column and on the sediment was quantified based on emission data of produced water and drilling waste for all oil and gas fields on the Norwegian continental shelf in 2008. Our results show that cutting particles contribute substantially to the total impact of offshore oil and gas production on marine sediments, with a relative contribution of 55% and 31% on the regional and global scale, respectively. In contrast, the contribution of particulate emissions to the total impact on the marine water column is of minor importance. We conclude that particles are an important stressor in marine ecosystems, particularly for marine sediment, and particulate emissions should therefore be included in a (life cycle) impact assessment of offshore oil and gas production. PMID:21735543

Veltman, Karin; Huijbregts, Mark A J; Rye, Henrik; Hertwich, Edgar G

2011-10-01

62

42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.  

Code of Federal Regulations, 2010 CFR

...RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against...

2010-10-01

63

42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.  

Code of Federal Regulations, 2011 CFR

...RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against...

2011-10-01

64

Sampling of power plant stacks for air toxic emissions: Topical report for Phases 1 and 2  

SciTech Connect

Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions.

NONE

1995-02-21

65

Gas scrubber and method  

Microsoft Academic Search

Apparatus and method for scrubbing gases such as flue gases by subjecting the gases to a shower of gas scrubbing solid particulate material is disclosed. The scrubbing is desirably effected in a downwardly extending passage leading from the top of a stack from which flue gases are diverted into the top of the passage. The aggregate mass of the solid

Johnson

1981-01-01

66

STUDY ON THE FEASIBILITY AND DESIGN OF AUTOMATIC PARTICULATE SIZE DISTRIBUTION ANALYZER FOR SOURCE EMISSIONS  

EPA Science Inventory

The objective of this program was to evolve a method for the automatic determination of the size distribution of particulates within stack gas effluent streams. This device was designed to cover the typical mass concentration range encountered upstream as well as downstream of em...

67

23. Brick coke quencher, brick stack, metal stack to right, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. Brick coke quencher, brick stack, metal stack to right, coke gas pipe to left; in background, BOF building, limestone piles, Levy's Slag Dump. Looking north/northwest - Rouge Steel Company, 3001 Miller Road, Dearborn, Wayne County, MI

68

Post-test analysis of 20kW molten carbonate fuel cell stack operated on coal gas. Final report, August 1993--February 1996  

SciTech Connect

A 20kW carbonate fuel cell stack was operated with coal gas for the first time in the world. The stack was tested for a total of 4,000 hours, of which 3,900 hours of testing was conducted at the Louisiana Gasification Technology Incorporated, Plaquemine, Louisiana outdoor site. The operation was on either natural gas or coal gas and switched several times without any effects, demonstrating duel fuel capabilities. This test was conducted with 9142 kJ/m{sup 3} (245 Btu/cft) coal gas provided by a slipstream from Destec`s entrained flow, slagging, slurry-fed gasifier equipped with a cold gas cleanup subsystem. The stack generated up to 21 kW with this coal gas. Following completion of this test, the stack was brought to Energy Research Corporation (ERC) and a detailed post-test analysis was conducted to identify any effects of coal gas on cell components. This investigation has shown that the direct fuel cell (DFC) can be operated with properly cleaned and humidified coal-as, providing stable performance. The basic C direct fuel cell component materials are stable and display normal stability in presence of the coal gas. No effects of the coal-borne contaminants are apparent. Further cell testing at ERC 1 17, confirmed these findings.

NONE

1996-05-01

69

Greenhouse Gas and Particulate Emissions and Impacts from Cooking Technologies in Africa  

NASA Astrophysics Data System (ADS)

In much of Africa, the largest fraction of energy consumption occurs within the residential sector and is derived primarily from woodfuels burned in simple stoves with poor combustion characteristics. Many of the products of incomplete combustion (PICs) are damaging to human health, particularly when they are concentrated in poorly ventilated indoor environments. Incomplete combustion also has potentially harmful impacts on the climate. Prevalent PICs include methane, a potent greenhouse gas (GHG) that is among the pollutants subject to controls under the Kyoto Protocol as well as carbon monoxide (CO), non-methane hydrocarbons (NMHCs) and particulate matter (PM), which can all have an effect on climate, but are not subject to controls under Kyoto. In addition, when woodfuels are used at a rate that reduces standing stocks of trees over the medium or long term, the CO2 released by combustion also has an impact. The choice of stove and fuel technology can have a significant impact on the emission of GHGs as well as on human exposure to health damaging pollutants. In this paper we analyze the emissions of different household energy technologies on a life-cycle basis. We use emission factors to estimate the emissions associated with production, distribution and end-use of common household fuels and assess the likely impacts of these emissions on public health and the global environment. We focus largely on charcoal, a popular fuel in many sub-Saharan African countries. Charcoal is produced by heating wood in the absence of sufficient air for complete combustion to occur. This process removes moisture and most of the volatile compounds. The compounds driven off in the process consist of condensable tars as well as many gaseous hydrocarbons, including ~40 g CH4 per kg of charcoal produced. Combining upstream and end-use emissions, every meal cooked with charcoal has 2-10 times the global warming effect of cooking the same meal with firewood and 5-12 times the effect of cooking the same meal with LPG or kerosene. When charcoal is produced in large quantities, as it is in Africa, the net warming effect can exceed the impact from the "modern energy sector" (transportation and industry) by 50-100 percent, even if charcoal is produced on a sustainable cycle so that all of the wood harvested for charcoal production is allowed to regenerate. However, while charcoal may be worse than firewood with respect to greenhouse gas emissions, it is an improvement with respect to exposure to health damaging pollutants, particularly particulate matter (PM). Levels of PM in households using charcoal are over 90 percent lower than households using open wood fires (316 -(159) mg/m3 for households using charcoal in a common improved stove compared to 3764 (360) mg/m3) for households using wood in open fires: mean (standard error)). These differences in exposure are consistent with 30 and 50 percent reductions in the incidence of acute respiratory infection (ARI) in adults and children under 5 respectively. Reconciling the costs and benefits of different household energy technologies creates a difficult policy challenge, particularly with the severe budgetary and resource constraints that household consumers and government agencies face in sub-Saharan Africa.

Kammen, D. M.; Bailis, R.; Kituyi, E.; Ezzati, M.

2003-12-01

70

Particulate and gas sampling of prescribed fires in South Georgia, USA  

NASA Astrophysics Data System (ADS)

Gaseous and particulate species from two prescribed fires were sampled in-situ, to better characterize prescribed burn emissions. Measurements included gaseous and fine particulate matter (PM2.5) species, particle number concentration, particulate organic carbon (POC) speciation, water-soluble organic carbon (WSOC) and water-soluble iron. Major PM2.5 components included OC (˜57%), EC (˜10%), chloride (˜1.6%), potassium (˜0.7%) and nitrate (˜0.9%). Major gaseous species include carbon dioxide, carbon monoxide, methane, ethane, methanol and ethylene. Particulate organic tracers of biomass burning, such as levoglucosan, dehydroabietic acid and retene, increased significantly during the burns. Water-soluble organic carbon (WSOC) also increased significantly during the fire and levels are highly correlated with total potassium (K) (R2 = 0.93) and levoglucosan (R2 = 0.98). The average WSOC/OC ratio was 0.51 ± 0.03 and did not change significantly from background levels. Thus, the WSOC/OC ratio may not be a good indicator of secondary organic aerosol (SOA) in regions that are expected to be impacted by biomass burning. Results using a biomass burning source profile derived from this work further indicate that source apportionment is sensitive to levels of potassium in biomass burning source profiles. This underscores the importance of quantifying local biomass burning source profiles.

Balachandran, Sivaraman; Pachon, Jorge E.; Lee, Sangil; Oakes, Michelle M.; Rastogi, Neeraj; Shi, Wenyan; Tagaris, Efthimios; Yan, Bo; Davis, Aika; Zhang, Xiaolu; Weber, Rodney J.; Mulholland, James A.; Bergin, Michael H.; Zheng, Mei; Russell, Armistead G.

2013-12-01

71

An Interdisciplinary Investigation of Student Ability to Connect Particulate and Macroscopic Representations of a Gas  

NSDL National Science Digital Library

This interdisciplinary project assessed the extent to which students in general education courses across two departments understood the assumptions of small-particle models and the ways in which these models relate to measurable properties. As part of this project, we embedded conceptually-oriented questions on written assessments in general education courses in physics and chemistry. Questions were drawn from the published literature in chemical and physics education and were developed by the research team. The results of this project provide a baseline measurement of the extent to which a diverse population of students in introductory physical science courses was able to develop and use particulate models to reason about macroscopic observables.

Monteyne, Kereen; Gonzalez, Barbara L.; Loverude, Michael E.

2009-01-24

72

Sampling of power plant stacks for air toxic emissions: Final report for Phases 1 and 2  

SciTech Connect

A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical characterization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in two phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.

NONE

1995-04-28

73

Utility stack opacity troubleshooting guidelines  

Microsoft Academic Search

Stack plume visibility, otherwise defined as plume opacity, has become a concern to the utility industry. This concern stems from the fact that some coal-fired stations with operating FGD systems have been cited for opacity in excess of the New Source Performance Standards (NSPS) even though the particulate mass emissions are within regulated limits. Postulated causes for the unacceptable opacities

R. J. Keeth; D. A. Balfour; F. M. Meserole; T. Defries

1991-01-01

74

D0 Vent Stacks  

SciTech Connect

There are two nitrogen/argon exhaust headers in the D0 cryogenic piping system, one for the liquid argon dewar and another for the three argon calorimeters. These headers serve two functions, venting both nitrogen exhaust from the cooling loops and cold argon gas should any argon vessel blow a relief. These headers are vacuum jacketed until they exit the building. At that point, uninsulated exhaust stacks direct the flow into the atmosphere. This note deals with the these stacks.

Fuerst, J.D.; /Fermilab

1988-01-22

75

Understanding the effect of reformate gas components and stack component impurities on the performance of PEM fuel cells  

NASA Astrophysics Data System (ADS)

The performance can be lost depending on the concentration and type of reformate components. Gas crossover in PEMFCs can also cause performance loss and these effects are also presented. Impurities such as acetone coming from composite stack components and sealants can also deteriorate the performance severely. Electrochemical impedance spectroscopy (EIS) is used as a diagnostic tool to study the impurity poisoning. Reformate contains N2 and CO2 and these components affect performance differently. These effects were quantified using anode overvoltage. Data for anode overvoltage shows that CO2 yields a significant poisoning effect (about 30 mV) on a Pt electrode. Cyclic voltammetry (CV) data showed that CO was produced in-situ from CO2 and H 2 (reverse water gas shift (RWGS) reaction) on both Pt and Pt/Ru electrodes. The coverage of CO achieved by RWGS can reach 5 x 10-7 mol/cm2 on an electrode with 0.4 mg/cm2 Pt under open circuit with normal operating conditions. This work also investigated how pressure, gas composition, and temperature affect the RWGS reaction in a PEMFC for both Pt and Pt/Ru alloy catalysts. The data are shown to be consistent with a kinetic catalytic model and not with an equilibrium model. Data was presented on H2 and O2 crossover in PEMFCs. Electrochemical techniques and mass balance measurements were used to quantify the crossover under typical working conditions. Mixed potential theory was applied to analyze the effect of gas crossover on open circuit voltage (OCV) of PEMFCs. Off-gassing from bipolar plates previously identified styrene, acetone, t-butyl alcohol, and dimethyl succinate as impurities. The effects of those impurities were quantified with both poisoning-recovery transient curves and steady state VI curves before, during, and after poisoning on anode and cathode side respectively. The poisoning effects of them to the anode side are smaller than to the cathode side. Cyclic voltammetry and electrochemical impedance spectroscopy were used to analyze the poisoning mechanisms of the above species. CV data showed that these organic species can be oxidized at about 0.6 V (vs. dynamic hydrogen electrode (DHE)) on a Pt electrode. Analysis of EIS data suggests that when these impurities were applied to the anode side, they deteriorated the cell performance by crossing over to the cathode side and increased the cathode resistances.

Gu, Tao

76

Pyrolysis-gas chromatography/mass spectrometry analyses of biological particulates collected during recent space shuttle missions.  

PubMed

Biological particulates collected on air filters during shuttle missions (STS-40 and STS-42) were identified using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). A method was developed for identifying the atmospheric particles and their sources through the analysis of standard materials and the selection of "marker" compounds specific to the particle type. Pyrolysis spectra of biological standards were compared with those of airborne particles collected during two space shuttle missions; marker compounds present in the shuttle particle spectra were matched with those of the standards to identify the source of particles. Particles of 0,5--1-mm diameter and weighing as little as 40 micrograms could be identified using this technique. The Py-GC/MS method identified rat food and soilless plant-growth media as two sources of particles collected from the shuttle atmosphere during flight. PMID:11536649

Matney, M L; Limero, T F; James, J T

1994-09-15

77

Pyrolysis-gas chromatography/mass spectrometry analyses of biological particulates collected during recent space shuttle missions  

NASA Technical Reports Server (NTRS)

Biological particulates collected on air filters during shuttle missions (STS-40 and STS-42) were identified using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). A method was developed for identifying the atmospheric particles and their sources through the analysis of standard materials and the selection of "marker" compounds specific to the particle type. Pyrolysis spectra of biological standards were compared with those of airborne particles collected during two space shuttle missions; marker compounds present in the shuttle particle spectra were matched with those of the standards to identify the source of particles. Particles of 0,5--1-mm diameter and weighing as little as 40 micrograms could be identified using this technique. The Py-GC/MS method identified rat food and soilless plant-growth media as two sources of particles collected from the shuttle atmosphere during flight.

Matney, M. L.; Limero, T. F.; James, J. T.

1994-01-01

78

GAS CHROMATOGRAPHY/MATRIX ISOLATION-FOURIER TRANSFORM INFRARED SPECTROMETRY FOR THE IDENTIFICATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN URBAN AIR PARTICULATE MATTER  

EPA Science Inventory

The capabilities of gas chromatography/matrix isolation-Fourier transform infrared (GC/MI-FTIR) spectrometry for detecting and identifying polycyclic aromatic hydrocarbons (PAHs) in urban air particulate matter are demonstrated. he ability of GC/MI-FTIR to discriminate between PA...

79

Gene Stacking  

Microsoft Academic Search

\\u000a A small but increasing proportion of genetically modified crops harbour two or more novel traits due to ‘stacked’ transgenes.\\u000a A variety of methods can be used to achieve stacking, albeit with limitations. Transgene stacking can potentially widen the\\u000a scope of current plant genetic manipulation to allow whole new biochemical pathways to be introduced into plants, or to overcome\\u000a a range

E. Douglas; C. Halpin

80

Interim Particulate Matter Test Method for the Determination of Particulate Matter from Gas Turbine Engines, SERDP Project WP-1538 Final Report  

EPA Science Inventory

Under Project No. WP-1538 of the Strategic Environmental Research and Development Program, the U. S. Air Force's Arnold Engineering Development Center (AEDC) is developing an interim test method for non-volatile particulate matter (PM) specifically for the Joint Strike Fighter (J...

81

Simulation of gas dynamics, radiation and particulates in volcanic plumes on Io  

NASA Astrophysics Data System (ADS)

Volcanic plumes on Jupiter's moon Io are modeled using the direct simulation Monte Carlo (DSMC) method. The main goal of this work is to improve the understanding of Ionian atmosphere itself and the internal processes that are responsible for the volcanic plumes with rarefied gas dynamics modeling techniques developed for aerospace engineering applications. A DSMC model including spherical geometry, variable gravity, internal energy exchange (discrete vibration- translation and continuous rotation-translation energy exchange) in the gas, infrared and microwave emission from the gas, multi-domain sequential calculation to resolve the fast emission event, opacity and two phase gas/particle flow, has been developed. Increasing confidence in our model has been built up through the encouraging matches to and agreements with a variety of observations, such as plume shape, vertical gas column density in the plumes, plume images, plume shadows, ring depositions, etc. A concept of virtual vent is proposed for both volcanic tube and lava lake plumes. A parametric study of the two most important parameters at the virtual vent—velocity and temperature—is performed. Constraints are put on the vent conditions via the observables such as the canopy shock heights, peak gas deposition ring radii, vertical and tangential gas column densities, and total gas mass and emission power. Also, the flow of refractory 1 nm 1 ?m particles entrained in the gas is modeled with “overlay” techniques which assume that the background gas flow is not altered by the particles. The column density along the tangential lines-of-sight and the shadow cast by the plume are calculated and compared with Voyager and Galileo images. Encouraging matches are found between simulations and observations. The model predicts the existence of a canopy-shaped shock inside the gas plume, a multiple bounce shock structure around a dayside plume, a frost depletion by the gas bounce, concentration of emission in the vibrational bands in the vent vicinity and re-emission at the shocks for certain band. An upper limit on the size of spherical particles that can track the gas flow in the outer portion of the plumes is ˜10 nm. Particles of size ˜1 nm can track the gas flow well throughout the entire plume. A subsolar frost temperature in the range of ˜110 118 K is suggested.

Zhang, Ju

82

Algebraic stacks  

Microsoft Academic Search

This is an expository article on the theory of algebraic stacks. After introducing the general theory, we concentrate in the\\u000a example of the moduli stack of vector bundles, giving a detailed comparison with the moduli scheme obtained via geometric\\u000a invariant theory.

Tomás L Gómez

2001-01-01

83

Stacked generalization  

Microsoft Academic Search

: This paper introduces stacked generalization, a scheme for minimizing the generalizationerror rate of one or more generalizers. Stacked generalization works by deducing the biases of thegeneralizer(s) with respect to a provided learning set. This deduction proceeds by generalizing ina second space whose inputs are (for example) the guesses of the original generalizers when taughtwith part of the learning set

David H. Wolpert

1992-01-01

84

Fuel cell stack compressive loading system  

DOEpatents

A fuel cell module comprising a stack of fuel cells with reactant gas manifolds sealed against the external surfaces of the stack includes a constraint system for providing a compressive load on the stack wherein the constraint system maintains the stack at a constant height (after thermal expansion) and allows the compressive load to decrease with time as a result of the creep characteristics of the stack. Relative motion between the manifold sealing edges and the stack surface is virtually eliminated by this constraint system; however it can only be used with a stack having considerable resiliency and appropriate thermal expansion and creep characteristics.

Fahle, Ronald W. (Manchester, CT); Reiser, Carl A. (Glastonbury, CT)

1982-01-01

85

On Stacking  

NASA Astrophysics Data System (ADS)

The term 'stacking' is normally associated with ? - ? interactions between aromatic moieties. The parallel alignment between adjacent DNA bases arguably constitutes the best-known example and provides the dominating contribution to the overall stability of DNA duplexes. Beyond canonical ? - ? interactions, a preliminary inspection of crystal structures of nucleic acids and their complexes with proteins reveals a wealth of additional stacking motifs including edge-to-face, H - ? , cation-?, lone pair-? and anion-? interactions. Given the ubiquity and diversity of such motifs it seems reasonable to widen the meaning of stacking beyond the standard cofacial interactions between pairs of aromatics.

Egli, Martin

86

On Stacking  

NASA Astrophysics Data System (ADS)

The term ‘stacking' is normally associated with ? - ? interactions between aromatic moieties. The parallel alignment between adjacent DNA bases arguably constitutes the best-known example and provides the dominating contribution to the overall stability of DNA duplexes. Beyond canonical ? - ? interactions, a preliminary inspection of crystal structures of nucleic acids and their complexes with proteins reveals a wealth of additional stacking motifs including edge-to-face, H - ? , cation-?, lone pair-? and anion-? interactions. Given the ubiquity and diversity of such motifs it seems reasonable to widen the meaning of stacking beyond the standard cofacial interactions between pairs of aromatics.

Egli, Martin

87

Determination of polycyclic aromatic sulfur heterocycles in diesel particulate matter and diesel fuel by gas chromatography with atomic emission detection.  

PubMed

The sulfur content of diesel fuel is of environmental concern because sulfur can facilitate the formation of diesel particulate matter (DPM) and sulfur dioxide (SO2) in the exhaust can poison catalytic converters. The US Environmental Protection Agency (EPA) has established more stringent regulations to reduce the sulfur content of diesel fuels in the near future. In this study, various types of organosulfur compounds in DPM extracts and the corresponding fuels have been determined by gas chromatography with atomic emission detection. The diesel fuels used have sulfur contents of 2284 and 433 ppm, respectively, and are labeled as high-sulfur and low-sulfur diesel fuels. The compounds identified are mainly polycyclic aromatic sulfur heterocycles (PASHs). In the fuels tested, trimethylbenzothiophenes (TMBTs), dibenzothiophenes (DBTs), and 4-methyldibenzothiophene (4-MDBT) were the most abundant sulfur compounds, while larger PASH compounds were more abundant in DPM extracts. The high-sulfur diesel fuel contained a larger proportion of PASHs with one or two rings (lighter PASHs). In DPM, the concentrations of total organic sulfur and individual PASHs are higher for the high-sulfur diesel fuel, and the relative percentage of one or two-ring PASHs is higher as well. The influence of engine load on the DPM composition was also examined. With increasing load, the PASH concentration in DPM decreased for lighter PASHs, increased for heavier PASHs, and had a bell-shaped distribution for PASHs in between. PMID:16574137

Liang, Fuyan; Lu, Mingming; Birch, M Eileen; Keener, Tim C; Liu, Zifei

2006-05-01

88

Development of a gas chromatography–mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere  

Microsoft Academic Search

A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography–mass spectrometry (GC–MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion,

E. Borrás; P. Sánchez; A. Muñoz; L. A. Tortajada-Genaro

2011-01-01

89

Potential health hazards from thermal degradation events - Particulate vs. gas phase effects  

NASA Technical Reports Server (NTRS)

The effect of instillation of ultrafine TiO2 particles (10-nm anatase-TiO2 and 12-nm rutile-TiO2 (administered in doses from 60 to 1000 microg/rat and 500 microg/rat, respectively) on the respiratory tract of exposed rats was compared to the effects of larger (250 nm anatase-TiO2 and 220-nm rutile-TiO2 particles (given in doses 500 or 1000 microg/rat and 500 microg/rat, respectively). These effects were also compared to the effects of inhalation of 20-nm and 250-nm anatase-TiO2 particles and inhalation with surrogate gas phase components (HF and HCl). It was found that ultrafine TiO2 particles induced greater inflammatory reaction in the lung, had greater adverse effect on alveolar macrophage-mediated clearance function, and had a greater potential to induce mediators which can adversely affect other lung cells than did larger-sized particles. Inhalation of surrogate gas phase components caused injury only to the upper respiratory tract, in contrast to the ultrafine particles, which affected the deep lung.

Oberdorster, Gunter; Ferin, Juraj; Finkelstein, Jacob; Baggs, Raymond; Stavert, D. M.; Lehnert, Bruce E.

1992-01-01

90

Foam formation and mitigation in a three-phase gas-liquid-particulate system.  

PubMed

Foaming is of great concern in a number of industrial processes involving three-phase gas-liquid-finely divided solid systems such as those encountered in the vitrification of highly radioactive nuclear waste slurries and sludges. Recent work has clearly shown that the surface properties of the particles such as hydrophilicity, hydrophobicity or biphilicity (i.e. partially wetted by water) are the cause of foamability and foam stability. The literature data on particles causing foaminess and foam stability in the absence of any surfactant are rather scarce. This paper presents experimental observations on aqueous foams with polyhedral structures containing over 90% air generated due to the presence of irregularly-shaped fine crystalline particles of sodium chloride which were modified into amphiphilic particles by physical adsorption of a cationic surfactant. Cross-polarized light microscopy was used to visualize the physical adsorption of the surfactant on the crystal surface. It is shown that these biphilic or amphiphilic particles attach to the air bubble surface and prevent the coalescence of bubbles, thereby extending the life of the foam. The foaming power of solid particles increases with an increase in the concentration of amphiphilic particles, and a maximum in foaminess is observed which is due to two competing effects. Amphiphilic particles promote foamability by attachment to the bubble surfaces as individual particles and foam inhibition due to the clustering or flocculation of particles in the bulk at high particle concentrations. We studied the adsorption of amphiphilic particles at a planar air-water surface and found that the degree of foamability correlates well with the particle coverage (i.e. adsorption density) at the air-liquid surface. An exploratory study was also conducted using an antifoam recently developed by IIT researchers to mitigate foaming in particle-laden gas-liquid systems. PMID:16997269

Vijayaraghavan, Krishna; Nikolov, Alex; Wasan, Darsh

2006-11-16

91

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios.  

PubMed

The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17-78.72mg/g, 26,139.80-35,932.98 and 5735.22-13,431.51ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26-83.70% and 16.30-29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82-797.76ng/g) was approximately 6.92-25.08 times higher than that of the gaseous phase (26.27-36.07ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO3) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency. PMID:25460974

Yang, Tzu-Ting; Lin, Shaw-Tao; Lin, Tser-Sheng; Chung, Hua-Yi

2015-02-15

92

Particulate Hot Gas Stream Cleanup Technical Issues: Quarterly report, July 1-September 30, 1996  

SciTech Connect

This is the eighth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, additional analyses were performed on ashes from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. Work continued on the HGCU data base being constructed in Microsoft Access. A variety of information has been entered into the data base, including numerical values, short or long text entries, and photographs. Detailed design of a bench top device for high temperature measurement of ash permeability has also begun. In addition to these activities, a paper was prepared and a poster was presented summarizing recent work performed under this contract at the 1996 DOE/METC Contractor`s Conference. A presentation was also given corresponding to the manuscript entitled Particle Characteristics and High-Temperature Filtration that was prepared for publication in the Proceedings of the Thirteenth Annual International Pittsburgh Coal Conference held this September in Pittsburgh, PA. Arrangements have been made to be present at the DOE/METC Modular Gas Cleanup Rig (MGCR) at the conclusion of the next run of the DOE/METC air blown Fluid Bed Gasifier (FBG). This visit will include on-site sampling to collect and characterize the filter cakes collected during FGB operation. Task 2 efforts during the past quarter focused on hoop tensile testing of Schumacher FT20 and Refractron 326 candle filter elements removed from the Karhula APF after 540 hours of service.

Pontius, D.H.

1996-12-09

93

The Direct FuelCell™ stack engineering  

NASA Astrophysics Data System (ADS)

FuelCell Energy (FCE) has developed power plants in the size range of 300 kW to 3 MW for distributed power generation. Field-testing of the sub-megawatt plants is underway. The FCE power plants are based on its Direct FuelCell™ (DFC) technology. This is so named because of its ability to generate electricity directly from a hydrocarbon fuel, such as natural gas, by reforming it inside the fuel cell stack itself. All FCE products use identical 8000 cm 2 cell design, approximately 350-400 cells per stack, external gas manifolds, and similar stack compression systems. The difference lies in the packaging of the stacks inside the stack module. The sub-megawatt system stack module contains a single horizontal stack whereas the MW-class stack module houses four identical vertical stacks. The commonality of the design, internal reforming features, and atmospheric operation simplify the system design, reduce cost, improve efficiency, increase reliability and maintainability. The product building-block stack design has been advanced through three full-size stack operations at company's headquarters in Danbury, CT. The initial proof-of-concept of the full-size stack design was verified in 1999, followed by a 1.5 year of endurance verification in 2000-2001, and currently a value-engineered stack version is in operation. This paper discusses the design features, important engineering solutions implemented, and test results of FCE's full-size DFC stacks.

Doyon, J.; Farooque, M.; Maru, H.

94

Particulate hot gas stream cleanup technical issues. Quarterly report, April 1 - June 30, 1996  

SciTech Connect

This is the seventh in a series of quarterly reports describing the activities performed for this project. Our analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, we received and analyzed a hopper ash sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota`s Energy and Environmental Research Center (UNDEERC). We also received six ash samples from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. We selected one of the filter cake ashes from this batch of samples for detailed analyses. We continued our work on the HGCU data base we are constructing in Microsoft Access{reg_sign}. We have been entering a variety of information into the data base, including numerical values, short or long text entries, and photographs. Task 2 efforts during the past quarter focused on hoop tensile testing of Schumacher FT20 and Refractron candle filter elements removed from the Karhula APF after {approximately}540 hours of service.

NONE

1996-12-31

95

Innovative application of Fluoro-tagging to trace airborne particulate and gas phase PBDE exposures  

PubMed Central

Polybrominated diphenyl ethers (PBDEs) are flame retardants applied as coatings to many consumer products, including household items. PBDEs are released and produce airborne vapors and dusts. Inhalation of particle-phase and/or gas-phase PBDEs is therefore a major route of exposure. In an attempt to mimic realistic airborne exposures, actual uptake and deposition of particles and vapors, we prepared and characterized particles for future animal exposure studies. To trace the particles in environmental and biological systems, we employed fluoro-tagging. We synthesized, characterized and employed three PBDE congeners 35, 47 and 99, and five fluoro-substituted-PBDEs (F-PBDEs), 17-F5?, 25-F5?, 28-F3?, 35-F5?, 47-F3, 99-F3? for this study. The PBDE congeners were selected because they are commonly found in house dust. For that reason we coated spherical silica particles of 3 ?m and C18 endcapped silica as representative and inert support materials, with 20%, 30% and 40% PBDEs. We determined the particle size distributions by aerodynamic particle size spectrometry and the morphology by scanning electron microscopy. The suitability of the fluoro-tagged tracers to mimic their corresponding parent PBDEs was investigated by extraction studies from spiked blood serum. Our study is of fundamental importance to the development of xenobiotic tracers for monitoring routes of human exposure to PBDEs and understanding uptake of PBDEs from particles and vapors. PMID:19111055

Klösener, Johannes; Peters, Thomas M.; Adamcakova-Dodd, Andrea; Teesch, Lynn; Thorne, Peter S.; Robertson, Larry W.; Luthe, Gregor

2009-01-01

96

Particulate hot gas stream cleanup technical issues. Quarterly report, January--March 1996  

SciTech Connect

To identify which ash characteristics can lead to problems with filtration, the authors have assembled 235 ash samples from eleven facilities involved in METC`s HGCU program. They have analyzed many of these ashes with a variety of laboratory tests. Physical attributes of the particles that they have examined include size distribution, specific surface area, particle morphology, and bulk ash cohesivity and permeability. They have also performed a range of chemical analyses on these ashes, as well as characterizations of agglomerates of ash removed from filter vessels at Tidd and Karhula. They are in the process of assembling the data obtained in these studies into an interactive data base which will help the manufacturers and operators of high-temperature barrier filters tailor their designs and operations to the specific characteristics of the ashes they are collecting. In order to understand the thermal and mechanical behavior of the various types of ceramic materials used in hot gas filtration, they have been performing hoop and axial tensile tests, thermal expansion, compression, and creep evaluations of these materials at temperatures up to 1,800 F. Nondestructive testing methods they perform on filter specimens include density and ultrasonic velocity. To date they have evaluated various characteristics of Dupont/Lanxide PRD-66, Dupont composite, 3M composite, IF and P Fibrosics, Refractron, Schumacher, and Blasch alumina mullite materials.

NONE

1996-05-21

97

Particulate hot gas stream cleanup technical issues. Quarterly report, January 1--March 31, 1998  

SciTech Connect

The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on January 20 to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF). Comparisons were made between laboratory analyses of these PSDF ashes and field data obtained from facility operation. In addition, selected laboratory techniques were reviewed to assess their reproducibility and the influence of non-ideal effects and differences between laboratory and filter conditions on the quantities measured. Further work on the HGCU data base is planned for the next quarter. Two Dupont PRD-66 candle filters, one McDermott candle filter, one Blasch candle filter, and one Specific Surfaces candle filter were received at SRI for testing. A test plan and cutting plan for these candles was developed. Acquisition of two of the Dupont PRD-66 candle filters will allow candle-to-candle variability to be examined.

NONE

1998-08-01

98

Tailor Made Synthesis of T-Shaped and ?-STACKED Dimers in the Gas Phase: Concept for Efficient Drug Design and Material Synthesis  

NASA Astrophysics Data System (ADS)

Non-covalent interactions play a key role in governing the specific functional structures of biomolecules as well as materials. Thus molecular level understanding of these intermolecular interactions can help in efficient drug design and material synthesis. It has been found from X-ray crystallography that pure hydrocarbon solids (i.e. benzene, hexaflurobenzene) have mostly slanted T-shaped (herringbone) packing arrangement whereas mixed solid hydrocarbon crystals (i.e. solid formed from mixtures of benzene and hexafluorobenzene) exhibit preferentially parallel displaced (PD) ?-stacked arrangement. Gas phase spectroscopy of the dimeric complexes of the building blocks of solid pure benzene and mixed benzene-hexafluorobenzene adducts exhibit similar structural motifs observed in the corresponding crystal strcutures. In this talk, I will discuss about the jet-cooled dimeric complexes of indole with hexafluorobenzene and p-xylene in the gas phase using Resonant two photon ionzation and IR-UV double resonance spectroscopy combined with quantum chemistry calculations. In stead of studying benzene...p-xylene and benzene...hexafluorobenzene dimers, we have studied corresponding indole complexes because N-H group is much more sensitive IR probe compared to C-H group. We have observed that indole...hexafluorobenzene dimer has parallel displaced (PD) ?-stacked structure whereas indole...p-xylene has slanted T-shaped structure. We have shown here selective switching of dimeric structure from T-shaped to ?-stacked by changing the substituent from electron donating (-CH3) to electron withdrawing group (fluorine) in one of the complexing partners. Thus, our results demonstrate that efficient engineering of the non-covalent interactions can lead to efficient drug design and material synthesis.

Kumar, Sumit; Das, Aloke

2013-06-01

99

The use of a housecleaning product in an indoor environment leading to oxygenated polar compounds and SOA formation: Gas and particulate phase chemical characterization  

NASA Astrophysics Data System (ADS)

This work investigates Secondary Organic Aerosol (SOA) formed by limonene ozonolysis using a housecleaning product in indoor environment. This study combines simulation chamber ozonolysis experiments and field studies in an experimental house allowing different scenarios of housecleaning product use in real conditions. Chemical speciation has been performed using a new method based on simultaneous sampling of both gas and particulate phases on sorbent tubes and filters. This method allowed the identification and quantification of about 35 products in the gas and particulate phases. Among them, products known to be specific from limonene ozonolysis such as limononaldehyde, ketolimonene and ketolimonic acid have been detected. Some other compounds such as 2-methylbutanoic acid had never been detected in previous limonene ozonolysis studies. Some compounds like levulinic acid had already been detected but their formation remained unexplained. Potential reaction pathways are proposed in this study for these compounds. For each experiment, chemical data are coupled together with physical characterization of formed particles: mass and size and number distribution evolution which allowed the observation of new particles formation (about 87,000 particle cm-3). The chemical speciation associated to aerosol size distribution results confirmed that limonene emitted by the housecleaning product was responsible for SOA formation. To our knowledge, this work provides the most comprehensive analytical study of detected compounds in a single experiment for limonene ozonolysis in both gaseous and particulate phases in real indoor environment.

Rossignol, S.; Rio, C.; Ustache, A.; Fable, S.; Nicolle, J.; Même, A.; D'Anna, B.; Nicolas, M.; Leoz, E.; Chiappini, L.

2013-08-01

100

Stacking Water  

NSDL National Science Digital Library

In this lesson, students become familiar with how ocean water forms density-stratified layers in many places. They design and carry out a series of tests to show how water masses of four different densities interact, using clear straws to stack colored water of different salinities. Temperature is varied to increase the differences in density of each water sample.

101

Stacking Up  

ERIC Educational Resources Information Center

Chimneys and stacks appear to be strong and indestructible, but chimneys begin to deteriorate from the moment they are built. Early on, no signs are apparent; but deterioration accelerates in subsequent years, and major repairs are soon needed instead of minor maintenance. With proper attention, most structures can be repaired and continue to…

Naylor, Jim

2005-01-01

102

INSTRUMENTATION FOR MONITORING THE OPACITY OF PARTICULATE EMISSIONS CONTAINING CONDENSED WATER  

EPA Science Inventory

On-stack instrumentation and methodology were developed to monitor the opacity of particulate pollutants in stationary source emissions containing condensed water. The instrument continuously extracts and measures the opacity of representative samples of particulate effluent. It ...

103

Regenerative process and system for the simultaneous removal of particulates and the oxides of sulfur and nitrogen from a gas stream  

DOEpatents

A process and system for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseous The government of the United States of America has rights in this invention pursuant to Contract No. DE-AC21-88MC 23174 awarded by the U.S. Department of Energy.

Cohen, Mitchell R. (Troy, NY); Gal, Eli (Lititz, PA)

1993-01-01

104

Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere.  

PubMed

A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography-mass spectrometry (GC-MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1). Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5±1%, a reproducibility of 13±3% and detection limits of 0.05-0.18 pg m(-3) for the particulate phase and 26-88 pg m(-3) for the gaseous phase. Finally, the methodology was successfully applied to rural and agricultural samples in the Mediterranean area. PMID:21704758

Borrás, E; Sánchez, P; Muñoz, A; Tortajada-Genaro, L A

2011-08-01

105

Application of modern online instrumentation for chemical analysis of gas and particulate phases of exhaust at the European Commission heavy-duty vehicle emission laboratory.  

PubMed

The European Commission recently established a novel test facility for heavy-duty vehicles to enhance more sustainable transport. The facility enables the study of energy efficiency of various fuels/scenarios as well as the chemical composition of evolved exhaust emissions. Sophisticated instrumentation for real-time analysis of the gas and particulate phases of exhaust has been implemented. Thereby, gas-phase characterization was carried out by a Fourier transform infrared spectrometer (FT-IR; carbonyls, nitrogen-containing species, small hydrocarbons) and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-TOFMS; monocyclic and polycyclic aromatic hydrocarbons). For analysis of the particulate phase, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS; organic matter, chloride, nitrate), a condensation particle counter (CPC; particle number), and a multiangle absorption photometer (MAAP; black carbon) were applied. In this paper, the first application of the new facility in combination with the described instruments is presented, whereby a medium-size truck was investigated by applying different driving cycles. The goal was simultaneous chemical characterization of a great variety of gaseous compounds and particulate matter in exhaust on a real-time basis. The time-resolved data allowed new approaches to view the results; for example, emission factors were normalized to time-resolved consumption of fuel and were related to emission factors evolved during high speeds. Compounds could be identified that followed the fuel consumption, others showed very different behavior. In particular, engine cold start, engine ignition (unburned fuel), and high-speed events resulted in unique emission patterns. PMID:21126058

Adam, T W; Chirico, R; Clairotte, M; Elsasser, M; Manfredi, U; Martini, G; Sklorz, M; Streibel, T; Heringa, M F; Decarlo, P F; Baltensperger, U; De Santi, G; Krasenbrink, A; Zimmermann, R; Prevot, A S H; Astorga, C

2011-01-01

106

MULTIWAVELENGTH TRANSMISSOMETER FOR MEASURING MASS CONCENTRATION OF PARTICULATE EMISSIONS  

EPA Science Inventory

A multiwavelength transmissometer potentially capable of making near-real-time measurements of particulate mass concentration in industrial stacks was developed. A computer program is employed to interpret the transmissometer data and translate the results into mass concentration...

107

Scrubber removes SOâ and particulates  

Microsoft Academic Search

Dravo Corp.'s simple-to-use, low-cost flue-gas desulfurizer, developed by C. J. Lewis of the National Lime Association, provides without plugging, a dewatered sludge product suitable for landfill. The unit permits burning of high-sulfur coals with stack gas emissions reduced below EPA standards; it is a nearly horizontal, rotating cylinder which operates with a concurrent flow of stack gases and scrubbing reagent,

1979-01-01

108

Fine particulate capture device  

NASA Technical Reports Server (NTRS)

To capture fine particulate matter in a gas such as air, a dielectric fluid is directed to the center of whichever face of a rotating disc is exposed to the air flow. The disc is comprised of two or more segments which bear opposite electrostatic potentials. As the dielectric fluid is centrifuged towards the periphery of the rotating disc, the fluid becomes charged to the same potential as the segment over which it is passing. Particulate matter is attracted to the charged segment and is captured by the fluid. The fluid then carries the captured particulate matter to a collection device such as a toroidal container disposed around the periphery of the disc. A grounded electrically-conductive ring may be disposed at the outer periphery of the disc to neutralize the captured particles and the fluid before they enter the container.

Peterson, V. S.; Siewert, R. D. (inventors)

1979-01-01

109

Condensation cleaning of particulate laden gases  

SciTech Connect

Particulate laden gas, especially those gases carrying particulates having a size in the micron or submicron range, are removed by humidifying the gas with water and thereafter subjecting the gas to indirect contact heat exchange sufficient to provide an energy transfer for water vapor condensation of at least 5 horsepower per 1000 cfm. Heat exchange is accomlished by passing the gas downwardly through an exchange element having smooth and vertical gas passages of a relatively large dimension.

Devries, E.

1981-08-18

110

Modular fuel-cell stack assembly  

DOEpatents

A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

Patel, Pinakin (Danbury, CT)

2010-07-13

111

TI-59 PROGRAMMABLE CALCULATOR PROGRAMS FOR IN-STACK OPACITY, VENTURI SCRUBBERS, AND ELECTROSTATIC PRECIPITATORS  

EPA Science Inventory

The report explains the basic concepts of in-stack opacity as measured by in-stack opacity monitors. Also included are calculator programs that model the performance of venturi scrubbers and electrostatic precipitators. The effect of particulate control devices on in-stack opacit...

112

Reactor for dry flue gas desulfurization  

SciTech Connect

A method is described for cleansing waste stack gases containing sulfur oxides from a generator of such gases, the generator being operable at a predetermined load and a turndown from such load. The method consists of: introducing the waste stack gases into a reaction zone; introducing an aqueous slurry containing an alkaline reagent into the zone for reaction of the reagent with the sulfur oxides, to produce an effluent stream containing precipitated particulate; passing the effluent stream from the reaction zone to a filter zone and filtering the precipitated particulate from the stream in the filter zone; controlling the ratio of aqueous slurry flow to waste stack gases to maintain a relatively dry flow in the filter zone; determining the level of waste stack gas flow velocity required for optimum mixing in the reaction zone of sulfur oxides and alkaline reagent; and varying the area of flow of waste stack gases at the point of introduction of such gases into the reaction zone with turndown in generator load to maintain the gas flow velocity at or near the level.

Camp, J.V.; Baran, S.J.

1986-04-29

113

40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.1320-90 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2012-07-01

114

40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.1320-90 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2010-07-01

115

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.120-94 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2014-07-01

116

40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.1320-90 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2011-07-01

117

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.120-94 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2010-07-01

118

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.120-94 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2013-07-01

119

40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.1320-90 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2013-07-01

120

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.120-94 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2012-07-01

121

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Gas meter or flow instrumentation calibration...Test Procedures § 86.120-94 Gas meter or flow instrumentation calibration...formaldehyde emissions requires the use of gas meters or flow instrumentation to...

2011-07-01

122

Ion chromatographic separation and quantitation of alkyl methylamines and ethylamines in atmospheric gas and particulate matter using preconcentration and suppressed conductivity detection.  

PubMed

Two methods based on ion chromatography (IC) were developed for the detection of methyl and ethyl alkyl amines (methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA) and triethylamine (TEA)) and NH(3)/NH(4)(+) in online atmospheric gas-particle and size-resolved particulate samples. The two IC methods were developed to analyze samples collected with an ambient ion monitor (AIM), an online gas-particle collection system, or with a Micro Orifice Uniform Deposit Impactor (MOUDI) for size-resolved particle samples. These methods enable selective and (semi-) quantitative detection of alkyl amines at ambient atmospheric concentrations (pptv and pgm(-3)) in samples where significant interferences can be expected from Na(+) and NH(4)(+), for example marine and rural air masses. Sample pre-concentration using a trace cation column enabled instrumental detection limits on the order of pmol (sub-ng) levels per sample, an improvement of up to 10(2) over current IC methods. Separation was achieved using a methanesulfonic acid gradient elution on Dionex CS12A and CS17 columns. The relative standard deviations in retention times during 3 weeks continuous (hourly) sampling campaigns ranged from 0.1 to 0.5% and 0.2 to 5% for the CS12A and CS17 across a wide dynamic range of atmospheric concentrations. Resolution of inorganic and organic cations is limited to 25min for online samples. Mass-dependent coelution of NH(4)(+)/MA/EA occurred on the CS12A column and DEA/TMA coeluted on both columns. Calibrations of ammonium show a non-linear response across the entire calibration range while all other analytes exhibit high linearity (R(2)=0.984-0.999), except for EA and TEA on the CS12A (R(2)=0.960 and 0.941, respectively). Both methods have high analytical accuracy for the nitrogenous bases ranging from 9.5 to 20% for NH(3) and <5-15% for the amines. Hourly observations of amines at Egbert, ON in October 2010 showed gaseous DMA and TMA+DEA at 1-10pptv in air, while particulate DMA and TMA+DEA were present at 0.5-4ng m(-3). A size-resolved particulate sample collected over 23h was found to contain DMA, TMA+DEA and MEA at 1.78, 8.15 and 0.03ngm(-3) mass loadings, with the amine mass enhanced in particle sizes between 100 and 1000nm. These results highlight a need for very sensitive and selective detection of methyl and ethyl amines in addition to NH(3) in continuous online monitoring strategies. PMID:22784696

VandenBoer, T C; Markovic, M Z; Petroff, A; Czar, M F; Borduas, N; Murphy, J G

2012-08-24

123

Effect of modified phosphate rock saturated by various salts on stack gas desulfurization in a fluidized bed reactor  

SciTech Connect

In this work, the suitability of phosphate ore treated with the varied salts such as FeSO{sub 4}, NaCl, CaCl{sub 2}, Na{sub 2}SiO{sub 3}, and Na{sub 2}SO{sub 4} as an alternative material for limestone and dolomite in flue gas desulfurization has been investigated. Also, the effect of the varied salts on calcination and sulfation of the raw, calcine, and semicalcined phosphate samples has been investigated in a differential fluidized bed reactor at 700-800{sup o}C (4 min) in air and 0.3% SO{sub 2}. It was established that the salts have prominent effects on sulfation and calcination. The changes in the pore structure and products obtained at the end of sulfation were investigated using BET surface area method. In conclusion, it was observed that the sulfation and calcination conversion ratios generally increased when the phosphate rock was treated the varied salts.

Kar, Y.; Kar, H. [Selcuk University, Konya (Turkey). Muhendislik Mimarlik Faculty

2006-04-15

124

Toward the Complete Characterization of Atmospheric Organic Particulate Matter: Derivatization and Two-Dimensional Comprehensive Gas Chromatography/Time of  

E-print Network

and Two-Dimensional Comprehensive Gas Chromatography/Time of Flight Mass Spectrometry as a Method by current analytical methods such as gas chromatography-mass spectrometry (GC-MS). The method of chemical of the chromatography column as compared to the chromatograms of underivatized samples. The improved peak shape made

Collett Jr., Jeffrey L.

125

Particulate matter and carbon monoxide in highland Guatemala: indoor and outdoor levels from traditional and improved wood stoves and gas stoves.  

PubMed

Area 22-h average carbon monoxide (CO), total suspended particulates (TSP), particles less than 10 microns in diameter (PM10), and particles less than 2.5 microns in diameter (PM2.5) measurements were made in three test homes of highland rural Guatemala in kitchens, bedrooms, and outdoors on a longitudinal basis, i.e. before and after introduction of potential exposure-reducing interventions. Four cookstove conditions were studied sequentially: background (no stove in use); traditional open woodstove, improved woodstove with flue (plancha), and bottled-gas (LPG) stove. With nine observations each, kitchen PM2.5 levels were 56 micrograms/m3 under background conditions, 528 micrograms/m3 for open fire conditions, 96 micrograms/m3 for plancha conditions, and 57 micrograms/m3 for gas stove conditions. Corresponding PM10/TSP levels were 173/174, 717/836, 210/276, 186/218 micrograms/m3. Corresponding CO levels were 0.2, 5.9, 1.4, 1.2 ppm. Comparisons with other studies in the area indicate that the reductions in indoor concentrations achieved by improved wood-burning stoves deteriorate with stove age. Mother and child personal CO and PM2.5 measurements for each stove condition demonstrate the same trend as area measurements, but with less differentiation. PMID:10979201

Naeher, L P; Leaderer, B P; Smith, K R

2000-09-01

126

Advanced particulate matter control apparatus and methods  

DOEpatents

Apparatus and methods for collection and removal of particulate matter, including fine particulate matter, from a gas stream, comprising a unique combination of high collection efficiency and ultralow pressure drop across the filter. The apparatus and method utilize simultaneous electrostatic precipitation and membrane filtration of a particular pore size, wherein electrostatic collection and filtration occur on the same surface.

Miller, Stanley J. (Grand Forks, ND); Zhuang, Ye (Grand Forks, ND); Almlie, Jay C. (East Grand Forks, MN)

2012-01-10

127

Role of Equalization Basins of Constructed Wetland Systems for Treatment of Particulate-Associated Elements in Flue Gas Desulfurization Waters  

Microsoft Academic Search

Pilot-scale experiments were performed to investigate the role of equalization basins used with constructed wetland systems\\u000a for treatment of flue gas desulfurization (FGD) waters. Analysis of FGD water samples indicated that aqueous concentrations\\u000a of Hg, As, and Se remained constant or changed very slightly in a pilot-scale equalization basin during a 24-h hydraulic retention\\u000a time (HRT). No change in toxicity

Meg M. Iannacone; James W. Castle; John H. Rodgers Jr

2009-01-01

128

Measurement of fine particulate and gas-phase species during the New Year's fireworks 2005 in Mainz, Germany  

Microsoft Academic Search

The chemical composition and chemically resolved size distributions of fine aerosol particles were measured at high time resolution (5min) with a time-of-flight aerosol mass spectrometer (TOF-AMS) during the New Year's 2005 fireworks in Mainz, central Germany. In addition, particle number concentrations and trace gas concentrations were measured using a condensation particle counter (CPC) and a proton transfer reaction mass spectrometer

Frank Drewnick; Silke S. Hings; Joachim Curtius; Gunter Eerdekens; Jonathan Williams

2006-01-01

129

40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...  

Code of Federal Regulations, 2012 CFR

...complete mixing of the exhaust and dilution air between the mixing orifice and each of the two sample probes (i.e., the particulate...complete mixing of the exhaust and dilution air between the mixing orifice and the particulate sample probe. It is recommended that...

2012-07-01

130

40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...  

Code of Federal Regulations, 2013 CFR

...complete mixing of the exhaust and dilution air between the mixing orifice and each of the two sample probes (i.e., the particulate...complete mixing of the exhaust and dilution air between the mixing orifice and the particulate sample probe. It is recommended that...

2013-07-01

131

40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...  

Code of Federal Regulations, 2014 CFR

...complete mixing of the exhaust and dilution air between the mixing orifice and each of the two sample probes (i.e., the particulate...complete mixing of the exhaust and dilution air between the mixing orifice and the particulate sample probe. It is recommended that...

2014-07-01

132

40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...  

Code of Federal Regulations, 2011 CFR

...Regulations for 1977 and Later Model Year New Light-Duty Vehicles...and particulate sampling capabilities as shown in Figure B94-5...particulate emissions sampling capabilities from a single system. (3... For 1990 through 1994 model year methanol-fueled...

2011-07-01

133

40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...  

Code of Federal Regulations, 2010 CFR

...Regulations for 1977 and Later Model Year New Light-Duty Vehicles...and particulate sampling capabilities as shown in Figure B94-5...particulate emissions sampling capabilities from a single system. (3... For 1990 through 1994 model year methanol-fueled...

2010-07-01

134

Fifty years of stacking  

NASA Astrophysics Data System (ADS)

Common-Mid-Point (CMP) stacking is a major process to enhance signal-to-noise ratio in seismic data. Since its appearance fifty years ago, CMP stacking has gone through different phases of prosperity and negligence within the geophysical community. During those times, CMP stacking developed from a simple process of averaging into a sophisticated process that involves complicated mathematics and state-of-the-art computation. This article summarizes the basic principles, assumptions, and violations related to the CMP stacking technique, presents a historical overview on the development stages of CMP stacking, and discusses its future potentiality.

Rashed, Mohamed

2014-06-01

135

Stacking with stochastic cooling  

NASA Astrophysics Data System (ADS)

Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles 'seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly 'protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently 'shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 10 5 the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the ' old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the 'radial' separation schemes and also gives some considerations to the 'azimuthal' schemes.

Caspers, Fritz; Möhl, Dieter

2004-10-01

136

COMPACT, IN-STACK, THREE SIZE CUT PARTICLE CLASSIFIER  

EPA Science Inventory

A compact, in-stack, three size cut particle classifier was designed, fabricated and tested. The classifer consists of a two-stage impactor and back-up filter designed to measure the particulate emissions from sources in three size ranges: greater than 3 micrometer, approximately...

137

Particulate technology issues  

SciTech Connect

Advanced systems for power generation based on coal combustion or gasification will require effective particulate control both for protection of equipment in the gas stream and for compliance with environmental regulations. These new classes of systems will require efficient removal of particles from gas streams at high temperature and high pressure. Primary candidates for particulate control are various types of ceramic filter systems; however, the long-term effects of hot gases and fine particles on the structure and filtration effectiveness of potential filter materials require further study. Thermal gradients induced by pulse cleaning are also of concern. Long-term patch tests'' will be conducted on ceramic disks of the same materials used in the fabrication of ceramic candles and ceramic crossflow filters. The primary issues to be addressed in these tests are the long-term physical, thermal, and chemical stability of the ceramic materials; long-term pressure drop and filtration characteristics of the ceramic filters; potential for irreversible blinding of filter elements; and long term performance and reliability of auxiliary hardware, such as the tube sheet and pulse cleaning systems. Each long-term patch test will require about 3 to 4 months of nearly continuous operation.

Pontius, D.H.; Vann Bush, P.

1992-01-01

138

Particulate technology issues  

SciTech Connect

Advanced systems for power generation based on coal combustion or gasification will require effective particulate control both for protection of equipment in the gas stream and for compliance with environmental regulations. These new classes of systems will require efficient removal of particles from gas streams at high temperature and high pressure. Primary candidates for particulate control are various types of ceramic filter systems; however, the long-term effects of hot gases and fine particles on the structure and filtration effectiveness of potential filter materials require further study. Thermal gradients induced by pulse cleaning are also of concern. Long-term ``patch tests`` will be conducted on ceramic disks of the same materials used in the fabrication of ceramic candles and ceramic crossflow filters. The primary issues to be addressed in these tests are the long-term physical, thermal, and chemical stability of the ceramic materials; long-term pressure drop and filtration characteristics of the ceramic filters; potential for irreversible blinding of filter elements; and long term performance and reliability of auxiliary hardware, such as the tube sheet and pulse cleaning systems. Each long-term patch test will require about 3 to 4 months of nearly continuous operation.

Pontius, D.H.; Vann Bush, P.

1992-12-01

139

Particulate hot gas stream cleanup technical issues: Task 1.0, Assessment of ash characteristics. Quarterly report, October-- December 1994  

SciTech Connect

This is the first in a series of quarterly reports describing the activities performed under Task 1. The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance presented in this report were designed to address the problems with filter operation that are apparently linked to the characteristics of the collected ash. This task is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APF`s) and to relate these ash properties to the operation and performance of these filters and their components. Observations of the filter assembly during site visits to the Tidd Demonstration Plant APF have led to the conclusion that that tenacious ash deposits that form in the APF apparently induce stresses that result in bent and/or broken ceramic candle filter elements. A site visit, was made to the Tidd APF on October 27, 1994 to collect ash samples from various locations in the filter vessel and to document the condition of the APF. A variety of laboratory analyses were performed on ash samples collected during this site visit to assess whether recent attempts to introduce larger particles into the ash deposits by derating the cyclone upstream of the APF have been successful. Some particles larger than 45 Jim were identified in various ash samples from the APF, but they account for less than 5 % of the mass of the ash. Although Scanning Electron Microscope EDX spectra and elemental maps lack the resolution to identify the bonds between particles in the ash agglomerates found in the APF, an excellent stereographic image of the structure of an ash nodule collected from the APF was generated with the Scanning Electron Microscope. The stereographic image was very enlightening as to the structure of the nodule.

NONE

1995-03-01

140

A REVIEW OF CURRENT METHODS FOR MEASURING PARTICULATE MATTER INCLUDING CONDENSABLES FROM STATIONARY SOURCES  

EPA Science Inventory

The PM10 ambient air particulate concentration standardhas created a need for updating measurement methods for PM10 emissions (nominally 10 um aerodynamic diameter and smaller) from stationary sources. Condensable emissions can be a significant portion of stack emissions. Further...

141

Stack Characterization System Development and Testing  

SciTech Connect

Oak Ridge National Laboratory, as well as the rest of the U.S. Department of Energy community, has numerous off-gas stacks that need to be decommissioned, demolished, and packaged for disposal. Disposal requires a waste disposition determination phase. Process knowledge typically makes a worst-case scenario decision that may place lower-level waste into a more expensive higher-level waste disposal category. Truly useful radiological and chemical sampling can be problematic on old stacks due to their inherent height and access hazards, and many of these stacks have begun to deteriorate structurally. A remote stack characterization system (SCS) that can manage sample and data collection removes people from the hazards and provides an opportunity for access to difficult to reach internal stack areas. The SCS is a remotely operated articulated radiological data recovery system designed to deploy down into off-gas stacks from the top via crane. The battery-powered SCS is designed to stabilize itself against the stack walls and move various data recovery systems into areas of interest on the inner stack walls. Stabilization is provided by a tripod structure; sensors are mounted in a rotatable bipod underneath the tripod. Sensors include a beta/gamma/alpha detector, a removable contaminant multi-sample automated sampler, and a multi-core remote core drill. Multiple cameras provide remote task viewing, support for sampling, and video documentation of the process. A delay in funding has delayed project delivery somewhat. Therefore, this paper describes the technology and shows fabrication and testing progress to the extent that data is available.

Noakes, Mark W [ORNL] [ORNL; Lind, Randall F [ORNL] [ORNL; Lloyd, Peter D [ORNL] [ORNL; Pin, Francois G [ORNL] [ORNL; Rowe, John C [ORNL] [ORNL

2011-01-01

142

Analysis of palladium concentrations in airborne particulate matter with reductive co-precipitation, He collision gas, and ID-ICP-Q-MS.  

PubMed

The concentration of platinum group elements (PGE) in the environment has increased significantly in the last 20 years mainly due to their use as catalysts in automotive catalytic converters. The quantitation of these metals in different environmental compartments is, however, challenging due to their very low concentrations and the presence of interfering matrix constituents when inductively coupled plasma-mass spectrometry (ICP-MS) is used for analysis. Previously, the research focus was on the analysis of platinum (Pt) and rhodium (Rh). However, due to the increasing use of palladium (Pd) in automotive catalytic converters, quantitation of this element in airborne particulate matter (PM) is also needed. Compared to Pt and Rh, measurements of Pd using ICP-MS are plagued by greater molecular interferences arising from elements such as copper (Cu), zinc (Zn) strontium (Sr), yttrium (Y), and zirconium (Zr). The aim of this study was to evaluate the applicability of reductive co-precipitation procedures using both mercury (Hg) and tellurium (Te) for the pre-concentration of Pd from airborne PM. Furthermore, helium (He) was tested as a collision gas for isotope dilution-inductively coupled plasma-quadrupole-mass spectrometry (ID-ICP-Q-MS) to measure Pd in the Hg and Te precipitates. Airborne PM samples (PM10) were collected from Neuglobsow (Brandenburg, north-eastern Germany) and Deuselbach (Rhineland-Palatinate, south-western Germany), considered to represent background levels, and from the city Frankfurt am Main (Hesse, Germany), a high-traffic area. Samples were first digested with aqua regia in a high-pressure asher (HPA) at 320 degrees C and 130 bar prior to the application of reductive co-precipitation procedures. The method was validated with road dust reference material BCR-723 and the CANMET-CCRMP reference material TDB-1 and WPR-1. In airborne PM collected at the background areas Neuglobsow and Deuselbach, Pd was detected with median concentrations values of 0.5 and 0.6 pg/m3, respectively. Much higher median concentration values of 14.8 pg Pd/m3 (detection limit = 0.01 pg Pd/m3) were detected in samples collected in the city of Frankfurt am Main. Results have shown that Hg co-precipitation depletes the concentrations of interfering matrix constituents by at least one order of magnitude more, compared to Te co-precipitation, making it a more effective method for the isolation and pre-enrichment of Pd from airborne PM prior to analysis. The use of a He gas flow of 120 ml/min in the plasma further minimized interferences, particularly those arising from CuAr+, YO+, and ZrO+ during the determination of Pd. The results demonstrate that Hg co-precipitation and the use of He collision gas, in combination with isotope dilution, are highly effective methods for the quantitation of Pd in airborne PM using ICP-MS. PMID:19784830

Alsenz, H; Zereini, F; Wiseman, C L S; Püttmann, W

2009-11-01

143

Porous coolant tube holder for fuel cell stack  

DOEpatents

A coolant tube holder for a stack of fuel cells is a gas porous sheet of fibrous material adapted to be sandwiched between a cell electrode and a nonporous, gas impervious flat plate which separates adjacent cells. The porous holder has channels in one surface with coolant tubes disposed therein for carrying coolant through the stack. The gas impervious plate is preferably bonded to the opposite surface of the holder, and the channel depth is the full thickness of the holder.

Guthrie, Robin J. (East Hartford, CT)

1981-01-01

144

Fluid&ParticulateSystems 424514/2010  

E-print Network

viscosity )1( 1density For homogeneous flows: D u½ L p QQ Q 1S 2 mixmix LG G GG 4f velocity)sameL(G liquid ­ solid Three phase flow: Gas-liquid-solid (trickled bed) or G/S or L/S with many size fractions&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2012 Vertical two-phase (G/L) flows RoNz 5 Upward Patterns

Zevenhoven, Ron

145

South African Particulates  

Atmospheric Science Data Center

article title:  Airborne Particulates over Southern Africa     View Larger ... the abundance of airborne particulates, or aerosols, over Southern Africa during the period August 14 - September 29, 2000. Low particle ...

2013-04-16

146

PARTICULATE MATTER RESEARCH 02  

EPA Science Inventory

2002 PARTICULATE MATTER GPRA Goal 1: Clean Air; Objective 1.1: Ozone, PM, and SO2 NAAQS; Sub-Objective 1.1.5: Particulate Matter Research Description: In July 1997, EPA revised the National Ambient Air Quality Standard (NAAQS) for Particulate Matter (PM), recogniz...

147

Development of on-site PAFC stacks  

SciTech Connect

PAFC (Phosphoric Acid Fuel Cell) has been researched for commercial use and demonstration plants have been installed in various sites. However, PAFC don`t have a enough stability yet, so more research and development must be required in the future. Especially, cell stack needs a proper state of three phases (liquid, gas and solid) interface. It is very difficult technology to keep this condition for a long time. In the small size cell with the electrode area of 100 cm{sup 2}, gas flow and temperature distributions show uniformity. But in the large size cell with the electrode area of 4000 cm{sup 2}, the temperature distributions show non-uniformity. These distributions would cause to be shorten the cell life. Because these distributions make hot-spot and gas poverty in limited parts. So we inserted thermocouples in short-stack for measuring three-dimensional temperature distributions and observed effects of current density and gas utilization on temperature.

Hotta, K.; Matsumoto, Y. [Kansai Electric Power Co., Amagasaki (Japan); Horiuchi, H.; Ohtani, T. [Mitsubishi Electric Corp., Kobe (Japan)

1996-12-31

148

Combustor for fine particulate coal  

DOEpatents

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

Carlson, L.W.

1988-01-26

149

Combustor for fine particulate coal  

DOEpatents

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

Carlson, L.W.

1988-11-08

150

Combustor for fine particulate coal  

DOEpatents

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover.

Carlson, Larry W. (Oswego, IL)

1988-01-01

151

Characterization of polar polycyclic aromatic compounds in a heavy-duty diesel exhaust particulate by capillary column gas chromatography and high-resolution mass spectrometry  

SciTech Connect

Polar normal-phase HPLC fractions of a heavy-duty diesel exhaust particulate, a National Bureau of Standards (NBS) standard reference material (SRM) 1650, were analyzed by capillary column GC coupled to both low- and high-resolution mass spectrometry (HRMS) using electron impact (EI) and negative ion chemical ionization (NICI). Over 80 polycyclic aromatic compounds (PAC), belonging to many different chemical classes (anhydrides, carboxaldehydes, diazaarenes, cyclic imides, nitrohydroxy-PAC, nitroaza-PAC, nitrodiaza-PAC, nitrolactones, and quinones) were tentatively identified. Ten of them were positively identified by comparison of retention times with authentic standards. Among them, phenazine and phthalic anhydride were positively identified for the first time in diesel exhaust particulates. In addition, cyclic imides and their alkylated derivatives were tentatively identified for the first time. Other novel polar chemical classes of PAC were evidenced by MICI MS using a direct-insertion probe.

Bayona, J.M.; Markides, K.E.; Lee, M.L.

1988-12-01

152

Stack filter classifiers  

SciTech Connect

Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

2009-01-01

153

Barrier RF stacking  

SciTech Connect

A novel wideband RF system, nicknamed the barrier RF, has been designed, fabricated and installed in the Fermilab Main Injector. The cavity is made of seven Finemet cores, and the modulator made of two bipolar high-voltage fast solid-state switches. The system can deliver {+-}7 kV square pulses at 90 kHz. The main application is to stack two proton batches injected from the Booster and squeeze them into the size of one so that the bunch intensity can be doubled. High intensity beams have been successfully stacked and accelerated to 120 GeV with small losses. The problem of large longitudinal emittance growth is the focus of the present study. An upgraded system with two barrier RF cavities for continuous stacking is under construction. This work is part of the US-Japan collaborative agreement.

Chou, W.; Wildman, D.; /Fermilab; Zheng, H.; /Caltech; Takagi, A.; /KEK, Tsukuba

2004-12-01

154

CROSS-STACK OPTICAL CONVOLUTION VELOCIMETER DEVELOPMENT AND EVALUATION OF A BREADBOARD DESIGN  

EPA Science Inventory

A new type of instrument has been designed and evaluated for the measurement of a line average of a stack gas velocity. The light output from a lamp is collimated and projected across the stack. A shadowgraph image of the turbulence in the stack is produced on the far side and th...

155

Laser pulse stacking method  

DOEpatents

A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

Moses, E.I.

1992-12-01

156

Organic Content of Particulate Matter In Turbine Engine Exhaust  

Microsoft Academic Search

Solid particulate matter, mainly carbon, emitted into the air from the combustion of fossil fuels contains a variety of organic species adsorbed on it. In our examination of these particulates from the combustion of kerosene type fuels in a gas turbine engine, attention was focused on polynuclear aromatic compounds, phenols, nitrosamines, and total organics. Polynuclears were determined by HPLC, GC\\/MS,

D. J. Robertson; R. H. Groth; T. J. Blasko

1980-01-01

157

Microstructure and particle-laden flow in diesel particulate filter  

Microsoft Academic Search

Due to the public awareness with regard to harmful diesel emissions, more strict diesel emissions standards such as Euro V in 2008 are being set in the world. As one of the key technologies, a diesel particulate filter (DPF) has been developed to reduce particulate matters (PM) in the after-treatment of exhaust gas. Since the structure of the filter is

Kazuhiro Yamamoto; Shingo Satake; Hiroshi Yamashita

2009-01-01

158

Pre-stack interpretation for depth mapping  

SciTech Connect

The efficient location and development of oil and gas reserves require the integration of their technical disciplines and close cooperation among geologists, geophysicists and engineers. Yet, they have a problem. The geologist and engineer measure their information in terms of depth below a datum, while the geophysicist is forced to take his measurements in two-way time. In the early stages of exploration, velocity surveys were rare. They assumed that the relationship between time and depth was relatively simple, changing slowly across the basin. As more data were obtained, particularly when they got two or more velocity surveys in the same field, they found that the time/depth relationships were complex. What is a stacking velocity. What is the relationship between stacking velocity and RMS or average velocity. How accurately can they determine RMS velocities from stacking velocities. How does a refraction model compare to a model derived from stacking velocities. An IBM PC-AT with an attached 9-track tape drive has been used to compute stacking velocities, residual statics, and a refraction model from marine data in the presence of 200 m/sec of time distortion caused by near-surface velocity variations. These results illustrate what can be done by an interpreter to improve his understanding of the relationship between time and depth within his prospect area.

Coons, R.L.

1988-03-01

159

Stacking up the Atmosphere  

NSDL National Science Digital Library

In this hands-on activity, participants learn the characteristics of the five layers of the atmosphere and make illustrations to represent them. They roll the drawings and place them in clear plastic cylinders, and then stack the cylinders to make a model column of the atmosphere.

Betsy Youngman

160

Toric Stacks II: Intrinsic Characterization of Toric Stacks  

Microsoft Academic Search

The purpose of this paper and its prequel (Toric Stacks I) is to introduce and develop a theory of toric stacks which encompasses and extends the notions of toric stacks defined in [Laf02, BCS05, FMN09, Iwa09, Sat09, Tyo10], as well as classical toric varieties. While the focus of the prequel is on how to work with toric stacks, the focus

Anton Geraschenko; Matthew Satriano

2011-01-01

161

EVALUATION OF CERAMIC FILTERS FOR HIGH-TEMPERATURE/HIGH-PRESSURE FINE PARTICULATE CONTROL  

EPA Science Inventory

High temperature gas turbines used to generate electric power require gas streams virtually free of particulate matter. Gas streams from high temperature, high pressure coal processes, such as low Btu gasification and pressurized fluidized bed combustion, require considerable par...

162

Particulate Air Pollution: The Particulars  

ERIC Educational Resources Information Center

Describes some of the causes and consequences of particulate air pollution. Outlines the experimental procedures for measuring the amount of particulate materials that settles from the air and for observing the nature of particulate air pollution. (JR)

Murphy, James E.

1973-01-01

163

Pitch based foam with particulate  

DOEpatents

A thermally conductive, pitch based foam composite having a particulate content. The particulate alters the mechanical characteristics of the foam without severely degrading the foam thermal conductivity. The composite is formed by mixing the particulate with pitch prior to foaming.

Klett, James W. (Knoxville, TN)

2001-01-01

164

Progress report and technology status development of an EG and G Berthold LB-150 alpha/beta particulate monitor for use on the East Tennessee Technology Park Toxic Substances Control Act Incinerator  

SciTech Connect

The purpose of this project was to modify and evaluate a commercially available EG and G Berthold LB-150 alpha-beta radionuclide particulate monitor for the high-temperature and moisture-saturation conditions of the East Tennessee Technology Park (formerly K-25 Site) Toxic Substances Control Act (TSCA) Incinerator stack. The monitor was originally outfitted for operation at gas temperatures of 150 F on the defunct Los Alamos National Laboratory (LANL) controlled air incinerator, and the objective was to widen its operating envelope. A laboratory apparatus was constructed that simulated the effects of water-saturated air at the TSCA Incinerator stack-gas temperatures, 183 F. An instrumented set of heat exchangers was constructed to then condition the gas so that the radionuclide monitor could be operated without condensation. Data were collected under the conditions of the elevated temperatures and humidities and are reported herein, and design considerations of the apparatus are provided. The heat exchangers and humidification equipment performed as designed, the Mylar film held, and the instrument suffered no ill effects. However, for reasons as yet undetermined, the sensitivity of the radionuclide detection diminishes as the gas temperature is elevated, whether the gas is humidified or not. The manufacturer has had no experience with (a) the operation of the monitor under these conditions and (b) any commercial market that might exist for an instrument that operates under these conditions. The monitor was not installed into the radiologically contaminated environment of the TSCA Incinerator stack pending resolution of this technical issue.

Shor, J.T.; Singh, S.P.N. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.; Gibson, L.V. Jr. [East Tennessee Technology Park, Oak Ridge, TN (United States). ASO Customer Services Div.

1998-06-01

165

Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling  

SciTech Connect

Since the mid-1980s the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity of particulate radioactive air samples. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor® 3000) used at PNNL for self absorption effects. There were two methods used in the study, 1) to compare the radioactivity concentration by direct gas-flow proportional counting of the filter to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection and 2) to evaluate sample filters by high resolution visual/infrared microscopy to determine the depth of material loading on or in the filter fiber material. Sixty samples were selected from the archive for acid digestion in the first method and about 30 samples were selected for high resolution visual/infrared microscopy. Mass loading effects were also considered. From the sample filter analysis, large error is associated with the average self absorption factor, however, when the data is compared directly one-to-one, statistically, there appears to be good correlation between the two analytical methods. The mass loading of filters evaluated was <0.2 mg cm-2 and was also compared against other published results. The microscopy analysis shows the sample material remains on the top of the filter paper and does not imbed into the filter media. Results of the microscopy evaluation lead to the conclusion that there is not a mechanism for significant self absorption. The overall conclusion is that self-absorption is not a significant factor in the analysis of filters used at PNNL for radioactive air stack sampling of radionuclide particulates and that an applied correction factor is conservative in determining overall sample activity. A new self absorption factor of 1.0 is recommended.

Barnett, J. M.

2008-08-22

166

Airborne particulate discriminator  

DOEpatents

A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

Creek, Kathryn Louise (San Diego, CA); Castro, Alonso (Santa Fe, NM); Gray, Perry Clayton (Los Alamos, NM)

2009-08-11

167

Feeder for particulate material  

Microsoft Academic Search

Feeder apparatus for feeding at a controlled variable rate particulate solid material, such as coal, from a supply conduit located above a gravimetric feeder to a discharge chute located below the feeder. The particulate material flows to the feeder from the supply conduit along a path having a generally vertical center line and the discharge chute provides a flow path

D. E. Christofer; A. J. Stock

1981-01-01

168

Diesel particulate traps  

Microsoft Academic Search

For use with a diesel engine having at least one exhaust bank, a particulate trap system is described comprising: an exhaust conduit ducting exhaust materials firstly through an exhaust cooler, thence to a diesel particulate trap, thence to the atmosphere, a by-pass conduit connected in parallel with the exhaust cooler between a first location upstream of the cooler and a

Burlington

1987-01-01

169

EFFECTIVE SAMPLING TECHNIQUES FOR PARTICULATE EMISSIONS FROM ATYPICAL STATIONARY SOURCES  

EPA Science Inventory

Sampling techniques for measuring particulate emissions from four 'atypical' stationary source categories were developed and evaluated. The categories include low effluent velocity streams, extended dimensions, partially or totally unconfined flow, and saturated gas streams or ga...

170

Stack inspection: theory and variants  

Microsoft Academic Search

Stack inspection is a security mechanism implemented in runtimes such as the JVM and the CLR to accommodate components with diverse levels of trust. Although stack inspection enables the fine-grained expression of access control policies, it has rather a complex and subtle semantics. We present a formal semantics and an equational theory to explain how stack inspection affects program behaviour

Cédric Fournet; Andrew D. Gordon

2002-01-01

171

Apparatus for sampling particulates in gases  

NASA Technical Reports Server (NTRS)

A device for sampling particulates in gases is described. The device is used to obtain samples of the upper atmosphere. The equipment used a common source of gas pressure to provide the driving gas of an air ejector pump. The sample collection cylinder has many slit impactors running longitudinally on the outer surface of a cylinder and terminating just short of each end of the cylinder.

Wood, R. C. (inventor)

1973-01-01

172

Heteroaromatic ?-Stacking Energy Landscapes  

PubMed Central

In this study we investigate ?-stacking interactions of a variety of aromatic heterocycles with benzene using dispersion corrected density functional theory. We calculate extensive potential energy surfaces for parallel-displaced interaction geometries. We find that dispersion contributes significantly to the interaction energy and is complemented by a varying degree of electrostatic interactions. We identify geometric preferences and minimum interaction energies for a set of 13 5- and 6-membered aromatic heterocycles frequently encountered in small drug-like molecules. We demonstrate that the electrostatic properties of these systems are a key determinant for their orientational preferences. The results of this study can be applied in lead optimization for the improvement of stacking interactions, as it provides detailed energy landscapes for a wide range of coplanar heteroaromatic geometries. These energy landscapes can serve as a guide for ring replacement in structure-based drug design. PMID:24773380

2014-01-01

173

Thermoacoustic Refrigerator's Stack Optimization  

NASA Astrophysics Data System (ADS)

The standing wave thermoacoustic refrigerator, which uses sound generation to transfer heat, was developed rapidly during the past four decades. It was regarded as a new, promising and environmentally benign alternative to conventional compression vapor refrigerators, although it was not competitive regarding the coefficient of performance (COP) yet. Thus the aim of this paper is to enhance thermoacoustic refrigerator's stack performance through optimization. A computational optimization procedure of thermoacoustic stack design was fully developed. The procedure was designed to achieve optimal coefficient of performance based on most of the design and operating parameters. Cooling load and acoustic power governing equations were set assuming the linear thermoacoustic theory. Lagrange multipliers method was used as an optimization technique tool to solve the governing equations. Numerical analyses results of the developed design procedure are presented. The results showed that the stack design parameters are the most significant parameters for the optimal overall performance. The coefficient of performance obtained increases by about 48.8% from the published experimental optimization methods. The results are in good agreement with past established studies.

El-Fawal, Mawahib Hassan; Mohd-Ghazali, Normah; Yaacob, Mohd. Shafik; Darus, Amer Nordin

2010-06-01

174

Chemical Characterization of Suspended Particulate Organic Matter by Pyrolysis-Gas Chromatography Coupled with Mass Spectrometry and High Performance Liquid Chromatography in the Bottom Nepheloid Layer of the Rhône Delta  

NASA Astrophysics Data System (ADS)

During the DYPOL-6 Mission in the Rhône delta the use of a metallic frame provided water samples at three levels of the underlying water column, 2, 1, and 0·5 m above the sea bottom. These sampling levels allowed determination of the characteristics of suspended organic material at the deeper layers of the bottom nepheloid layer and, eventually, their relations with the overlying suspended particulate matter. The results obtained by the measurement of the suspended particulate organic matter, the elemental analysis, the analysis of the main classes of organic compounds by pyrolysis-gas chromatography coupled with mass spectrometry and the determination of phenolic compounds by high performance liquid chromatography (HPLC) emphasized the functional characteristics of the Rhône deltaic system. Near the bottom, the lower water levels of the benthic nepheloid layer showed some obvious biogeochemical gradients related to the location of the sampling station: the amount of pyrolysis-derived phenolic compounds, aromatic hydrocarbons and carbohydrates in the suspended material was high at the stations directly exposed to input of the Rhône River. The stations from the river mouth to offshore areas showed the influence of the Rhône inflow. But sometimes, according to the river regime and the current orientation, the influence of the Liguro-provencal current oriented East-West was noticeable even near the river mouth. In the eastern region of the surveyed area, the stations submitted to this current indicated some specific characteristics: the nepheloid layer, concentrated 1 m above the bottom, had a high particulate organic carbon content and a relatively high amount of phenolic compounds which indicated a possible seagrass ( Posidonia oceanica) origin. At the more seaward stations, although the influence of the river input was always detectable, the suspended particulate matter was less abundant and essentially supplied by the local biogenic input: the lower water levels were enriched in compounds yielding acetonitrile upon pyrolysis, i.e. nitrogen-containing compounds. If the proximity of the river source and regime influenced the suspended particulate matter distribution and the geochemical characteristics of organic matter, the evolution through time of the bottom turbid flow from one station to another also had a great influence. Near the bottom, the terrestrial character is shown in the shoreward stations by high contents of pyrolysis-derived aromatic hydrocarbons and phenols as well as by lignin-derived phenolic compounds analysed by HPLC. In contrast, a marine character appeared in the seaward stations, emphasized by high values of pyrolysis-derived compounds indicative of carbohydrates and nitrogenous compounds as well as by phenolic compounds representative of phytoplankton production. However the upper water layers of the bottom nepheloid were generally more influenced by terrestrial input. Some trends emphasizing a microstratification of the water layers in the deeper levels of the bottom nepheloid, related to the existence of very thin bottom currents, or, maybe, to resuspension processes resulting from the bottom proximity, were shown by the geochemical characteristics of the three water levels analysed.

Gadel, François; Charrière, Bruno; Serve, Léon

1993-09-01

175

CEC-500-2010-FS-017 Volatility of Ultrafine Particulate  

E-print Network

. Limited research has been done to characterize compressed natural gas mass emissions and practically-volatile and semi-volatile fractions of ultrafine particulate matter emissions from compressed natural gas vehicles compressed natural gas, and emission control technologies that will best protect human health

176

A liquid water management strategy for PEM fuel cell stacks  

E-print Network

for fuel cell stacks consisting of a few cells, can also be used to prevent non-uniform gas distribution [5]. In the serial configuration the gas from the outlet of the first cell is fed to the inlet of the second cell and so on until the last cell... rates, this method was insufficient. Since no other means was readily or economically available, a water displacement method was used. The stack exhaust was connected to a water bottle with an exit submerged in the water to allow the inflow of gas...

Van Nguyen, Trung; Knobbe, M. W.

2003-02-25

177

Development of internal reforming carbonate fuel cell stack technology  

SciTech Connect

Activities under this contract focused on the development of a coal-fueled carbonate fuel cell system design and the stack technology consistent with the system design. The overall contract effort was divided into three phases. The first phase, completed in January 1988, provided carbonate fuel cell component scale-up from the 1ft{sup 2} size to the commercial 4ft{sup 2} size. The second phase of the program provided the coal-fueled carbonate fuel cell system (CGCFC) conceptual design and carried out initial research and development needs of the CGCFC system. The final phase of the program emphasized stack height scale-up and improvement of stack life. The results of the second and third phases are included in this report. Program activities under Phase 2 and 3 were designed to address several key development areas to prepare the carbonate fuel cell system, particularly the coal-fueled CFC power plant, for commercialization in late 1990's. The issues addressed include: Coal-Gas Related Considerations; Cell and Stack Technology Improvement; Carbonate Fuel Cell Stack Design Development; Stack Tests for Design Verification; Full-Size Stack Design; Test Facility Development; Carbonate Fuel Cell Stack Cost Assessment; and Coal-Fueled Carbonate Fuel Cell System Design. All the major program objectives in each of the topical areas were successfully achieved. This report is organized along the above-mentioned topical areas. Each topical area has been processed separately for inclusion on the data base.

Farooque, M.

1990-10-01

178

Radiant zone heated particulate filter  

DOEpatents

A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

Gonze, Eugene V [Pinckney, MI

2011-12-27

179

Size distribution of metals in particulate matter formed during combustion of residual fuel oil  

SciTech Connect

Between July 1992 and January 1993 three full-scale test programs were performed by Carnot for the Electric Power Research Institute and the Fuel Oil Users` Support (FOUS) Group, as part of a program for development and testing of various stack emissions models. One of the components of the program was determination of the concentrations of individual elements as a function of the size of particles suspended in flue gas. The size distributions of species are important because several aspects of system performance depend upon particulate matter size and composition: (1) the rate of ash deposition in the convection section, and activity of deposits for high temperature corrosion and SO{sub 3} formation, (2) the efficiency of precipitators for collection of individual elements, and (3) scattering of visible light and contribution of particles to stack plume opacity. Size distributions of major ash constituents were measured at the entrance and exit of the dust collectors during each of the field tests. To the authors` knowledge, these are the first reports of such measurements in residual oil-fired utility boilers. The focus, in the present paper, is on the composition of the particles entering the dust collectors.

Walsh, P. [Pennsylvania State Univ., University Park, PA (United States); Rovesti, W.C. [Electric Power Research Institute, Washington, DC (United States); Freeman, R.F. [Niagara Mohawk Power Corp., Oswego, NY (United States); Olen, K.R.; Washington, K.T.; Patrick, S.T.; Campbell, G.L.; Harper, D.S. [Florida Power & Light Co., West Palm Beach, FL (United States); Teetz, R.D.; Bennett, T.E. [Long Island Lighting Co., Glenwood Landing, NY (United States)] [and others

1994-08-01

180

CHARACTERIZATION OF STACK EMISSIONS FROM MUNICIPAL REFUSE-TO-ENERGY SYSTEMS  

EPA Science Inventory

Stack emissions from three municipal refuse-to-energy systems were characterized: refuse-derived fuel (RDF), mass burning (MASS) and modular (MOD). A comprehensive set of measurements was performed at each site to determine the physical and chemical properties of the particulate ...

181

IN-STACK PLUME OPACITY FROM ELECTROSTATIC PRECIPITATOR/SCRUBBER SYSTEM AT HARRINGTON UNIT 1  

EPA Science Inventory

The report gives results of theoretical modeling of particulate emission and in-stack plume opacity for the electrostatic precipitator (ESP)/scrubber system at Southwestern Public Service Company's Harrington Unit 1. The theoretical results of an emission rate of 17.8 ng/J and op...

182

Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling  

SciTech Connect

Since the mid-1980s, Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as the correction factor for self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. This value accounts for activity that cannot be detected by direct counting of alpha and beta particles. Emissions can be degraded or blocked by filter fibers for particles buried in the filter material or by inactive dust particles collected with the radioactive particles. These filters are used for monitoring air emissions from PNNL stacks for radioactive particles. This paper describes an effort to re-evaluate self-absorption effects in particulate radioactive air sample filters (Versapor® 3000, 47 mm diameter) used at PNNL. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Filter ratios were calculated by dividing the initial counts by the post-digestion counts with the expectation that post-digestion counts would be higher because digestion would expose radioactivity embedded in the filter in addition to that on top of the filter. Contrary to expectations, the post digestion readings were almost always lower than initial readings and averaged approximately half the initial readings for both alpha and beta activity. Before and after digestion readings appeared to be related to each other, but with a low coefficient of determination (R^2) value. The ratios had a wide range of values indicating that this method did not provide sufficient precision to quantify self-absorption effects. The microscopy analysis compares different filter loadings and shows that smaller particle sizes (under 10 micron) can readily be seen on the more lightly loaded filters. At higher loadings, however, the particle size is harder to differentiate. This study provides data on actual stack emission samples showing a range of mass loading conditions and visual evidence of particle size and distribution and also presents the difficulties in quantifying self-absorption effects using actual samples.

Barnett, J. M.; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

2009-02-17

183

Barrier RF stacking  

SciTech Connect

This paper introduces a new method for stacking beams in the longitudinal phase space. It uses RF barriers to confine and compress beams in an accelerator, provided that the machine momentum acceptance is a few times larger than the momentum spread of the injected beam. This is the case for the Fermilab Main Injector. A barrier RF system employing Finemet cores and high-voltage solid-state switches is under construction. The goal is to double the number of protons per cycle on the production target for Run2 and NuMI experiments.

Weiren Chou and Akira Takagi

2003-02-24

184

Asymmetric Flexible Supercapacitor Stack  

PubMed Central

Electrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs) have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm) based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM and HRTEM). An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

2008-01-01

185

Stacked Extreme Learning Machines.  

PubMed

Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. It provides a unified solution that can be used directly to solve regression, binary, and multiclass classification problems. In this paper, we propose a stacked ELMs (S-ELMs) that is specially designed for solving large and complex data problems. The S-ELMs divides a single large ELM network into multiple stacked small ELMs which are serially connected. The S-ELMs can approximate a very large ELM network with small memory requirement. To further improve the testing accuracy on big data problems, the ELM autoencoder can be implemented during each iteration of the S-ELMs algorithm. The simulation results show that the S-ELMs even with random hidden nodes can achieve similar testing accuracy to support vector machine (SVM) while having low memory requirements. With the help of ELM autoencoder, the S-ELMs can achieve much better testing accuracy than SVM and slightly better accuracy than deep belief network (DBN) with much faster training speed. PMID:25361517

Zhou, Hongming; Huang, Guang-Bin; Lin, Zhiping; Wang, Han; Soh, Yeng Chai

2014-10-28

186

Measurement of heat conduction through stacked screens  

NASA Technical Reports Server (NTRS)

This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature, and the hot end is maintained at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated heat flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel screens, 400-mesh phosphor bronze screens, and two different porosities of 325-mesh stainless steel screens. The wire diameter of the 400-mesh stainless steel and phosphor bronze screens was 25.4 micrometers and the 325-mesh stainless steel screen wire diameters were 22.9 micrometers and 27.9 micrometers. Standard porosity values were used for the experimental data with additional porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction to the heat conduction where the regenerator material is assumed to be a solid rod of the same cross sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze, and almost constant for the temperature range of 40 to 80 K at the cold end.

Lewis, M. A.; Kuriyama, T.; Kuriyama, F.; Radebaugh, R.

1998-01-01

187

Biofilters remove VOCs from stack gases  

SciTech Connect

Weyerhaeuser's strandboard plant in Grayling, Mich., is using biofiltration to remove volatile organic compounds (VOCs) at the site. Primary constituents in the Weyerhaeuser stack gases are alcohols, aldehydes, organic acids, benzene and toluene. The alternative to biofiltration is incineration, but because the concentration of VOCs in the stack gases is so dilute, natural gas would be required. Incineration would be costly, and could introduce pollution problems by generating excess carbon dioxide (CO[sub 2]) and possibly nitrogen oxides. Two pilot biofilters, each about 20ft by 100ft in area, with 4-ft thick media of bark and ground trim ends, are using naturally occurring bacteria to destroy VOCs emanating from a wood panel press and a wood flake dryer. The press offgas biofilter, activated February 1993, had risen to 93% efficiency in removing VOCs by mid-May. The flake dryer exhaust biofilter, placed in service in April, already was more than 80% efficient.

Not Available

1993-10-01

188

Stacked insulator induction accelerator gaps  

SciTech Connect

Stacked insulators, with alternating layers of insulating material and conducting film, have been shown to support high surface electrical field stresses. We have investigated the application of the stacked insulator technology to the design of induction accelerator modules for the Relativistic-Klystron Two-Beam Accelerator program. The rf properties of the accelerating gaps using stacked insulators, particularly the impedance at frequencies above the beam pipe cutoff frequency, are investigated. Low impedance is critical for Relativistic-Klystron Two-Beam Accelerator applications where a high current, bunched beam is trsnsported through many accelerating gaps. An induction accelerator module designs using a stacked insulator is presented.

Houck, T.I.; Westenskow, G.A.; Kim, J.S.; Eylon, S.; Henestroza, E.; Yu, S.S.; Vanecek, D.

1997-05-01

189

Simulation on Soot Oxidation with NO2 and O2 in a Diesel Particulate Filter  

Microsoft Academic Search

Although diesel engines have an advantage of low fuel consumption in comparison with gasoline engines, exhaust gas has more particulate matters (PM) including soot. As one of the key technologies, a diesel particulate filter (DPF) has been developed to reduce PM. When the exhaust gas passes its porous filter wall, the soot particles are trapped. However, the filter would readily

Kazuhiro Yamamoto; Shingo Satake; Hiroshi Yamashita; Akira Obuchi; Junko Uchisawa

2007-01-01

190

Stacking energies in DNA.  

PubMed

Variations in base mono- and dipoles result in variations in stacking energies for the 10 unique neighbor pairs in DNA. Stacking energies for pair M on N, expressed as TMN, were derived by matrix decomposition of a large set of linear algebraic expressions relating the measured Tm for subtransitions emanating from large polymeric DNAs, and the fractional neighbor frequencies, fMN, for the domains responsible for the transitions, Tm = sigma fMNTMN. Tm were determined for subtransitions that dissociate in approximately all-or-none fashion in high resolution melting profiles of partially deleted and recombinant forms of pBR322 DNA. Three different analytical maneuvers were undertaken to resolve subtransitions: site-specific cleavage of domains; deletion of domains; and addition of domains. Three dozen domains of widely divergent, quasi-random neighbor frequencies were identified and assigned, resulting in a unique set of values for TMN with standard deviation, sigma = +/- 0.23 degree C. The average difference between calculated and experimental Tm for domains is only +/- 0.17 degree C, indicating that the thermodynamic properties of these domains are not in any way unusual. Assuming delta S to be constant for all pairs, the corresponding delta HMN are found to have a precision of +/- 10 calories.mol-1 and an accuracy of +/- 606 calories.mol-1. TMN used to calculate melting curves by statistical mechanical analysis of sequences of the different plasmid specimens in this study were in quantitative agreement with observed curves for most sequences. These TMN differ significantly from those determined previously and also correlate poorly with values determined by quantum chemical analysis. Stabilities of neighbor pairs, expressed as the difference in free energy between that for a given pair (MN) and that for the average of like pairs (M, N), depend on the relationship of stacked purines and pyrimidines as follows. delta delta Gpu-py(-466 cal) greater than delta delta Gpu-pu(+52 cal) greater than delta delta Gpy-pu(+335 cal) Differences between experimental Tm and Tm calculated with TMN for the isolated neighbor pairs in the B-conformation are useful in the identification of altered structures and unusual modes of dissociation of helixes. A significantly higher Tm is observed for the highly biased repeated sequence synthetic helixes dA.dT, d(AGC).d(GCT), and d(GAT).d(ATC), reflecting auxiliary sources of stability such as bifurcated hydrogen bonds and/or altered structures for these helixes. PMID:1869547

Delcourt, S G; Blake, R D

1991-08-15

191

Sticky Windows: Chemical and Biological Characteristics of the Organic Film Derived from Particulate and Gas-Phase Air Contaminants Found on an Urban Impervious Surface  

Microsoft Academic Search

A novel environmentally derived mixture that integrates exposure to atmospherically derived gas- and particle-phase compounds\\u000a in urban areas—namely, the organic film that develops as a thin layer on urban impervious surfaces—was investigated for its\\u000a ability to induce gene expression via the aryl hydrocarbon receptor (AhR). The organic film on window glass from 21 sites\\u000a in downtown Toronto (Ontario, Canada) was

E. M. Hodge; M. L. Diamond; B. E. McCarry; G. A. Stern; P. A. Harper

2003-01-01

192

Void/particulate detector  

DOEpatents

Voids and particulates are detected in a flowing stream of fluid contained in a pipe by a detector which includes three transducers spaced about the pipe. A first transducer at a first location on the pipe transmits an ultrasonic signal into the stream. A second transducer detects the through-transmission of the signal at a second location and a third transducer at a third location upstream from the first location detects the back-scattering of the signal from any voids or particulates. To differentiate between voids and particulates a fourth transducer is positioned at a fourth location which is also upstream from the first location. The back-scattered signals are normalized with the through-transmission signal to minimize temperature fluctuations.

Claytor, Thomas N. (Woodridge, IL); Karplus, Henry B. (Hinsdale, IL)

1985-01-01

193

Method for immobilizing particulate materials in a packed bed  

DOEpatents

The present invention pertains generally to immobilizing particulate matter contained in a packed bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that (a) the particulate retains its essential chemical nature, (b) the local movement of the particulate particles is not unduly restricted, (c) bulk powder migration and is prevented, (d) physical and chemical access to the particulate is unchanged over time, and (e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of an individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport. 4 figs.

Even, W.R. Jr.; Guthrie, S.E.; Raber, T.N.; Wally, K.; Whinnery, L.L.; Zifer, T.

1999-02-02

194

Method for immobilizing particulate materials in a packed bed  

DOEpatents

The present invention pertains generally to immobilizing particulate matter contained in a "packed" bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that a) the particulate retains its essential chemical nature, b) the local movement of the particulate particles is not unduly restricted, c) bulk powder migration and is prevented, d) physical and chemical access to the particulate is unchanged over time, and e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport.

Even, Jr., William R. (Livermore, CA); Guthrie, Stephen E. (Livermore, CA); Raber, Thomas N. (Livermore, CA); Wally, Karl (Lafayette, CA); Whinnery, LeRoy L. (Livermore, CA); Zifer, Thomas (Manteca, CA)

1999-01-01

195

Stacking disorder in ice I.  

PubMed

Traditionally, ice I was considered to exist in two well-defined crystalline forms at ambient pressure: stable hexagonal ice (ice Ih) and metastable cubic ice (ice Ic). However, it is becoming increasingly evident that what has been called cubic ice in the past does not have a structure consistent with the cubic crystal system. Instead, it is a stacking-disordered material containing cubic sequences interlaced with hexagonal sequences, which is termed stacking-disordered ice (ice Isd). In this article, we summarise previous work on ice with stacking disorder including ice that was called cubic ice in the past. We also present new experimental data which shows that ice which crystallises after heterogeneous nucleation in water droplets containing solid inclusions also contains stacking disorder even at freezing temperatures of around -15 °C. This supports the results from molecular simulations, that the structure of ice that crystallises initially from supercooled water is always stacking-disordered and that this metastable ice can transform to the stable hexagonal phase subject to the kinetics of recrystallization. We also show that stacking disorder in ice which forms from water droplets is quantitatively distinct from ice made via other routes. The emerging picture of ice I is that of a very complex material which frequently contains stacking disorder and this stacking disorder can vary in complexity depending on the route of formation and thermal history. PMID:25380218

Malkin, Tamsin L; Murray, Benjamin J; Salzmann, Christoph G; Molinero, Valeria; Pickering, Steven J; Whale, Thomas F

2015-01-01

196

Spherical Torus Center Stack Design  

SciTech Connect

The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device.

C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz

2002-01-18

197

Syntheses and characterization of copper(II) carboxylate dimers formed from enantiopure ligands containing a strong ?···? stacking synthon: enantioselective single-crystal to single-crystal gas/solid-mediated transformations.  

PubMed

Tri- and tetrafunctional enantiopure ligands have been prepared from 1,8-naphthalic anhydride and the amino acids L-alanine, D-phenylglycine, and L-asparagine to produce (S)-2-(1,8-naphthalimido)propanoic acid (HL(ala)), (R)-2-(1,8-naphthalimido)-2-phenylacetic acid (HL(phg)), and (S)-4-amino-2-(1,8 naphthalimido)-4-oxobutanoic acid (HL(asn)), respectively. Reactions of L(ala)(-) with copper(II) acetate under a variety of solvent conditions has led to the formation and characterization by X-ray crystallography of three similar copper(II) paddlewheel complexes with different axial ligands, [Cu(2)(L(ala))(4)(THF)(2)] (1), [Cu(2)(L(ala))(4)(HL(ala))] (2), and [Cu(2)(L(ala))(4)(py)(THF)] (3). A similar reaction using THF and L(phg)(-) leads to the formation of [Cu(2)(L(phg))(4)(THF)(2)] (4). With the exception of a disordered component in the structure of 4, the naphthalimide groups in all of these compounds are arranged on the same side of the square, central paddlewheel unit, forming what is known as the chiral crown configuration. A variety of ?···? stacking interactions of the 1,8-naphthalimide groups organize all of these complexes into supramolecular structures. The addition of the amide group functionality in the L(asn)(-) ligand leads to the formation of tetrameric [Cu(4)(L(asn))(8)(py)(MeOH)] (5), where reciprocal axial coordination of one of the amide carbonyl oxygen atoms between two dimers leads to the tetramer. Extensive supramolecular interactions in 5, mainly the ?···? stacking interactions of the 1,8-naphthalimide supramolecular synthon, support an open three-dimensional structure containing large pores filled with solvent. When crystals of [Cu(4)(L(asn))(8)(py)(MeOH)] are exposed to (S)-ethyl lactate vapor, the coordinated methanol molecule is replaced by (S)-ethyl lactate, bonding to the copper ion through the carbonyl oxygen, yielding [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)] (6) without a loss of crystallinity. With the exception of the replacement of the one axial ligand, the molecular structures of 5 and 6 are very similar. In a similar experiment of 5 with vapors of (R)-ethyl lactate, again a change occurs without a loss of crystallinity, but in this case the (R)-ethyl lactate displaces only slightly more than half of the axial methanol molecules forming [Cu(4)(L(asn))(8)(py){((R)-ethyl lactate)(0.58)(MeOH)(0.42)}] (7). Importantly, in 7, the (R)-ethyl lactate coordinates through the hydroxyl group. When crystals of [Cu(4)(L(asn))(8)(py)(MeOH)] are exposed to vapors of racemic ethyl lactate, the coordinated methanol molecule is displaced without a loss of crystallinity exclusively by (S)-ethyl lactate, yielding a new form of the tetramer [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)], in which the ethyl lactate in the pocket bonds to the copper(II) ion through the carbonyl oxygen as with 6. Exposure of [Cu(4)(L(asn))(8)(py){((R)-ethyl lactate)(0.58)(MeOH)(0.42)}] to racemic ethyl lactate yields a third form of [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)], where the three forms of [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)] have differences in the number of ordered (S)-ethyl lactate molecules located in the interstitial sites. These results demonstrate enantioselective bonding to a metal center in the chiral pocket of both 5 and 7 during single-crystal to single-crystal gas/solid-mediated exchange reactions. PMID:21919476

Reger, Daniel L; Horger, Jacob J; Debreczeni, Agota; Smith, Mark D

2011-10-17

198

Multivariate analysis of mainstream tobacco smoke particulate phase by headspace solid-phase micro extraction coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.  

PubMed

A method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography (GC×GC) coupled to time-of-flight mass spectrometry (TOFMS) was developed and applied to evaluate profiles of volatile compounds present in mainstream tobacco smoke particulate matter trapped on glass fiber filters. Six SPME fibers were tested for the extraction capacities toward selected compounds, showing the best results for the polyacrylate fiber. The optimization of the extraction conditions was carried out using multivariate response surface methodology. Two cigarette types differing in a filter design were analyzed using optimized conditions. A template was built in order to generate comprehensive chemical information, which conceded obtaining consistent information across 24 chromatograms. Principal component analysis (PCA) allowed a clear differentiation of the studied cigarette types. Fisher ratio analysis allowed identification of compounds responsible for the chemical differences between the cigarette samples. Of the selected 143 most important ones, 134 analytes were reduced by the active carbon filter, while for nine, classical cellulose acetate filter was more efficient. PMID:25454146

Brokl, Micha?; Bishop, Louise; Wright, Christopher G; Liu, Chuan; McAdam, Kevin; Focant, Jean-François

2014-11-28

199

Monitoring of atmospheric gaseous and particulate polycyclic aromatic hydrocarbons in South African platinum mines utilising portable denuder sampling with analysis by thermal desorption-comprehensive gas chromatography-mass spectrometry.  

PubMed

Concentrations of diesel particulate matter and polycyclic aromatic hydrocarbons (PAHs) in platinum mine environments are likely to be higher than in ambient air due to the use of diesel machinery in confined environments. Airborne PAHs may be present in gaseous or particle phases each of which has different human health impacts due to their ultimate fate in the body. Here we report on the simultaneous sampling of both phases of airborne PAHs for the first time in underground platinum mines in South Africa, which was made possible by employing small, portable denuder sampling devices consisting of two polydimethylsiloxane (PDMS) multi-channel traps connected in series separated by a quartz fibre filter, which only require small, battery operated portable personal sampling pumps for air sampling. Thermal desorption coupled with comprehensive gas chromatography-mass spectrometry (TD-GC×GC-TofMS) was used to analyse denuder samples taken in three different platinum mines. The samples from a range of underground environments revealed that PAHs were predominantly found in the gas phase with naphthalene and mono-methylated naphthalene derivatives being detected at the highest concentrations ranging from 0.01 to 18?gm(-3). The particle bound PAHs were found in the highest concentrations at the idling load haul dump vehicle exhausts with a dominance of fluoranthene and pyrene. Particle associated PAH concentrations ranged from 0.47 to 260ngm(-3) and included benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene. This work highlights the need to characterise both phases in order to assess occupational exposure to PAHs in this challenging sampling environment. PMID:25582484

Geldenhuys, G; Rohwer, E R; Naudé, Y; Forbes, P B C

2015-02-01

200

Fluidizing device for solid particulates  

DOEpatents

A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

Diebold, James P. (Lakewood, CO); Scahill, John W. (Golden, CO)

1986-01-01

201

Fluidizing device for solid particulates  

DOEpatents

A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

Diebold, J.P.; Scahill, J.W.

1984-06-27

202

Inhalation of phosphine gas following a fire associated with fumigation of processed pistachio nuts.  

PubMed

On December 10, 2009, a fumigation stack containing aluminum phosphide became soaked with rain water and caught fire at a pistachio processing plant in Kern County, California. Untrained plant personnel responding to the fire had exposure to pyrolysis by-products, particulates, and extinguisher ingredients. Ten workers taken for medical evaluation had respiratory and nonspecific systemic symptoms consistent with exposure to phosphine gas. Six of the 10 workers had respiratory distress, indicated by chest pain, shortness of breath, elevated respiratory rate, or decreased oxygen saturation. Recommendations are made for the management of similar illnesses and prevention of similar exposures. PMID:23540306

O'Malley, Michael; Fong, Harvard; Sánchez, Martha E; Roisman, Rachel; Nonato, Yvette; Mehler, Louise

2013-01-01

203

40 CFR 52.528 - Control strategy: Sulfur oxides and particulate matter.  

Code of Federal Regulations, 2014 CFR

...State's plan are based on dispersion techniques not permitted by EPA's stack height rules. (b) The variance granted to the Turkey Point and Port Everglades plants of Florida Power and Light Company from the particulate emission limits of the plan is...

2014-07-01

204

OVERVIEW OF THE U.S. EPA (ENVIRONMENTAL PROTECTION AGENCY) ELECTROSTATIC PARTICULATE RESEARCH AND DEVELOPMENT PROGRAM  

EPA Science Inventory

The U.S. EPA's particulate research and development program, divided between an in-house laboratory effort and extramural work at various research institutes, makes use of electrostatics in most of the work associated with stack or ducted emissions. Research facilities which offe...

205

Fluidized-bed filter for particulate cleanup  

SciTech Connect

Successful development of advanced coal-fired power conversion systems often requires reliable and efficient gas-stream-cleanup devices that can remove particulate and gaseous pollutants from high temperature and high pressure gas streams. A novel filter concept for particulate cleanup has been developed at the Morgantown Energy Technology Center (METC). The filter consists of a fine screened surface immersed in a fluidized bed of granular material. As the gas stream passes through the fluidized bed, a layer of fine granular material is deposited and packed at the screen surface, which provides a natural filter to separate the fine particles from the gas stream. Since the filtering media is the granular material supplied by the fluidized bed, the filter is not subjected to blinding. Cleaning the filter (if necessary) is much easier than with a ceramic filter because the inflowing gas, not the cohesive forces, maintains the filter media at the screen surface. Therefore, the screensurface can be readily cleaned by momentarily interrupting the gas flow. A two-dimensional fluidized-bed filter cold model was designed, constructed, and operated to explore the feasibility of this novel concept.

Mei, J.S.; Yue, P.C.

1992-01-01

206

Health Effects of Particulate Matter  

NSDL National Science Digital Library

This EPA site gives a brief overview of how different sized particulate matter affects human health. It also discusses the environmental impacts of particulate matter, including haze and acid rain. The site also provides links to more in-depth resources about particle pollution and air quality criteria for particulate matter.

Environmental Protection Agency

207

Analysis of microsize particulates  

NASA Technical Reports Server (NTRS)

Unique methods for analyzing individual particles ranging in size from 0.01 to 1000 micrometers have been developed for investigation of nature of cosmic dust. Methods are applicable to particulate aerosols and contaminants characteristically encountered in studies of air pollution and in experiments designed to abate pollution.

Blanchard, M. B.; Farlow, N. H.; Ferry, G. V.

1972-01-01

208

Mobile laboratory with rapid response instruments for real-time measurements of urban and regional trace gas and particulate distributions and emission source characteristics.  

PubMed

Recent technological advances have allowed the development of robust, relatively compact, low power, rapid response (approximately 1 s) instruments with sufficient sensitivity and specificity to quantify many trace gases and aerosol particle components in the ambient atmosphere. Suites of such instruments can be deployed on mobile platforms to study atmospheric processes, map concentration distributions of atmospheric pollutants, and determine the composition and intensities of emission sources. A mobile laboratory containing innovative tunable infrared laser differential absorption spectroscopy (TILDAS) instruments to measure selected trace gas concentrations at sub parts-per-billion levels and an aerosol mass spectrometer (AMS) to measure size resolved distributions of the nonrefractory chemical components of fine airborne particles as well as selected commercial fast response instruments and position/velocity sensors is described. Examples of the range of measurement strategies that can be undertaken using this mobile laboratory are discussed, and samples of measurement data are presented. PMID:15575289

Kolb, Charles E; Herndon, Scott C; McManus, J Barry; Shorter, Joanne H; Zahniser, Mark S; Nelson, David D; Jayne, John T; Canagaratna, Manjula R; Worsnop, Douglas R

2004-11-01

209

Feeder for particulate material  

SciTech Connect

Feeder apparatus for feeding at a controlled variable rate particulate solid material, such as coal, from a supply conduit located above a gravimetric feeder to a discharge chute located below the feeder. The particulate material flows to the feeder from the supply conduit along a path having a generally vertical center line and the discharge chute provides a flow path having a generally vertical center line closely laterally spaced relative to the center line of flow to the feeder. The feeder apparatus has a horizontally extending housing with an upwardly facing inlet through which the material flows to the feeder and a downwardly facing outlet forming part of the discharge chute through which the material flows from the feeder. Within the housing is a main feeder conveyor including an endless belt with a generally horizontal span adapted to receive at one end the particulate material flowing to the feeder and to convey in a layer a measured quantity of material a horizontal distance across weighing means to an exit zone at the opposite end of the belt, the horizontal distance being substantially greater than the spacing between the center lines of flow to the feeder and through such discharge chute. Associated with the main feeder conveyor is a gravimetric control system for controlling the amount of material deposited on the belt. Particulate material that drops off the main conveyor belt at the exit zone is received on a return belt conveyor and carried in a reverse direction a sufficient distance to bring the material to the discharge chute. Cooperation between the main feeder conveyor and the return conveyor permits gravimetric feeding of particulate material to the discharge chute that is closely laterally spaced to the flow path of material to the main conveyor by a distance that is substantially less than the length of travel of the material on the main conveyor.

Christofer, D.E.; Stock, A.J.

1981-03-24

210

Sticky windows: chemical and biological characteristics of the organic film derived from particulate and gas-phase air contaminants found on an urban impervious surface.  

PubMed

A novel environmentally derived mixture that integrates exposure to atmospherically derived gas- and particle-phase compounds in urban areas-namely, the organic film that develops as a thin layer on urban impervious surfaces-was investigated for its ability to induce gene expression via the aryl hydrocarbon receptor (AhR). The organic film on window glass from 21 sites in downtown Toronto (Ontario, Canada) was found to contain a complex mixture of environmental contaminants typical of urban environments, notably PAHs, n-alkanes, PCBs, organochlorine (OC) pesticides, and polar constituents. Using a stably transfected reporter cell line, we found that the crude extract of organic film induces AhR-dependent gene expression in a dose-dependent fashion. Three subfractions of the crude extract induced significant luciferase expression: nonpolar aromatic > polar aromatic > nonpolar aliphatic. Recombination of the fractions did not lead to recovery of the full activity of the crude extract, which may indicate that some of the compounds lost during fractionation were significant contributors to the induction observed with the crude extract. The interactions between a tonic dose of B[ a]P (10(-7) M) and each of the aromatic fractions were determined to be antagonistic following analysis by the method of isoboles. Our results suggest that organic film makes up a diverse array of compounds active at the AhR and that these compounds may not interact in a strictly additive manner. PMID:12712271

Hodge, E M; Diamond, M L; McCarry, B E; Stern, G A; Harper, P A

2003-05-01

211

Studies on the behavior of ammonia and ammonium salts in the atmosphere (1) - Fractional collection of ammonia gas and particulate ammonium  

NASA Technical Reports Server (NTRS)

Methods for the fractional collection of trace amounts of atmospheric ammonia gas and ammonium particles on a two staged glass fiber filter are summarized. A standard glass fiber filter washed with distilled water and dried at 120 to 130 C was used. A second filter was impregnated with a mixture of 3% boric acid and 25% glycerin solution. The blank of glass fiber filters impregnated with a mixture of the above solution was very low for ammonia, i.e. 0.06 micrograms in a filter of 47 mm in diameter. The mean concentrations of ammonia and ammonium in air at Kawasaki, a polluted area, were 7.6 and 2.3 micrograms cu m, and those at Sanriku, an unpolluted area 0.9 and 0.2 micrograms cu m, respectively. Ratios of concentration levels of ammonium to total ammonia in the atmosphere were 0.3 and 0.2 for the polluted and unpolluted areas, respectively. Ammonium salts in air at both areas were not correlated with relative humidity. Variations in time of ammonia concentrations and sources in surrounding areas are also considered.

Kiin, K.; Fujimura, M.; Hashimoto, Y.

1981-01-01

212

Stacking interactions in PUFÂRNA complexes  

Microsoft Academic Search

Stacking interactions between amino acids and bases are common in RNA-protein interactions. Many proteins that regulate mRNAs interact with single-stranded RNA elements in the 3' UTR (3'-untranslated region) of their targets. PUF proteins are exemplary. Here we focus on complexes formed between a Caenorhabditis elegans PUF protein, FBF, and its cognate RNAs. Stacking interactions are particularly prominent and involve every

Yvonne Yiling Koh; Yeming Wang; Chen Qiu; Laura Opperman; Leah Gross; Traci M. Tanaka Hall; Marvin Wickens

2012-01-01

213

Particulate contamination removal from wafers using plasmas and mechanical agitation  

DOEpatents

Particulate contamination removal from wafers using plasmas and mechanical agitation. The present invention includes the use of plasmas with mechanical agitation for removing particulate matter from the surface of a wafer. The apparatus hereof comprises a mechanical activator, at least one conducting contact pin for transferring the vibration from the activator to the wafer, clamp fingers that maintain the wafer's position, and means for generating a plasma in the vicinity of the surface of the wafer, all parts of the cleaning apparatus except the mechanical activator and part of the contact pin being contained inside the processing chamber. By exposing a wafer to a plasma and providing motion thereto in a direction perpendicular to its surface, the bonding between the particulate matter and the surface may be overcome. Once free of the wafer surface, the particulates become charged by electrons from the plasma and are drawn into the plasma by attractive forces which keep them from redepositing. The introduction of a flowing gas through the plasma sweeps the particulates away from the wafer and out of the plasma. The entire surface is cleaned during one cleaning step. The use of an rf plasma to accomplish the particulate removal was found to remove more than 90% of the particulates.

Selwyn, Gary S. (Los Alamos, NM)

1998-01-01

214

Rigid particulate matter sensor  

DOEpatents

A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

Hall, Matthew (Austin, TX)

2011-02-22

215

Particulate matter dynamics  

E-print Network

A substantial fraction of the particulate matter released into the atmosphere by industrial or natural processes corresponds to particles whose aerodynamic diameters are greater than 50 mm. It has been shown that, for these particles, the classical description of Gaussian plume diffusion processes, is inadequate to describe the transport and deposition. In this paper we present new results concerning the dispersion of coarse particulate matter. The simulations are done with our own code that uses the Bulirsch Stoer numerical integrator to calculate threedimensional trajectories of particles released into the environment under very general conditions. Turbulent processes are simulated by the Langevin equation and weather conditions are modeled after stable (Monin-Obukhov length L> 0) and unstable conditions (L weather on the final deposition of these particles.

Cionco, Rodolfo G; Caligaris, Marta G

2012-01-01

216

Void/particulate detector  

DOEpatents

Apparatus for detecting voids and particulates in a flowing stream of fluid contained in a pipe may comprise: (a) a transducer for transmitting an ultrasonic signal into the stream, coupled to the pipe at a first location; (b) a second transducer for detecting the through-transmission of said signal, coupled to the pipe at a second location; (c) a third transducer for detecting the back-scattering of said signal, coupled to the pipe at a third location, said third location being upstream from said first location; (d) circuit means for normalizing the back-scattered signal from said third transducer to the through-transmitted signal from said second transducer; which normalized signal provides a measure of the voids and particulates flowing past said first location.

Claytor, T.N.; Karplus, H.B.

1983-09-26

217

Designing wet duct/stack systems for coal-fired plants  

SciTech Connect

A multitude of variables must be accounted for during the design and development of a wet-stack flue gas desulfurization system. The five-phase process detailed in this article has proven effective on more than 60 wet-stack system design studies. The process is the result of studies by EPRI detailed in two reports entitled: entrainment in wet stacks', and 'wet stacks design guide. A basic understanding of these concepts will help inform early design decisions and produce a system amenable to wet operation. 2 refs., 5 figs.

Anderson, D.K.; Maroti, L.A. [Alden Research Laboratory Inc. (United States)

2006-03-15

218

Diesel particulate traps  

SciTech Connect

For use with a diesel engine having at least one exhaust bank, a particulate trap system is described comprising: an exhaust conduit ducting exhaust materials firstly through an exhaust cooler, thence to a diesel particulate trap, thence to the atmosphere, a by-pass conduit connected in parallel with the exhaust cooler between a first location upstream of the cooler and a second location downstream of the cooler but upstream of the trap, a first valve in the exhaust conduit between the first location and the cooler, a second valve in the by-pass conduit, and microprocessor-based control means which carries out the steps of (a) allowing normal operation with the first valve open and the second valve closed, (b) when backpressure in the exhaust conduit reaches a predetermined level due to particulate build-up in the trap, gradually opening the second valve and closing the first valve, thereby allowing exhaust materials to by-pass the cooler, (c) when the trap begins to regenerate thereby causing increased temperature in the trap, closing the second valve and opening the first valve.

Burlington, K.H.

1987-08-11

219

Gas  

MedlinePLUS

... swallow and the breakdown of undigested food by bacteria in the large intestine. Certain foods may cause gas. Foods that produce gas in one person may not cause gas in another. You can reduce the amount of gas you have by Drinking lots of water and non-fizzy drinks Eating more slowly so ...

220

Innovations in high-temperature particulate filtration  

SciTech Connect

Fluidized-bed combustion and coal gasification expose sensitive equipment, such as high-speed turbines, to hot combustion offgases. In order to prevent erosion, corrosion, and other damage to sensitive equipment, such systems now incorporate high-temperature particulate filters. One device often considered for such applications uses a design similar to a baghouse (i.e., multiple banks of porous filter bags that remove particulate from gas streams). In this case, however, instead of polyester or teflon fabric, the filter elements are made of rigid ceramic or similar materials. These devices are sometimes called `candle filters,` and the individual ceramic filter elements are frequently called `candles.` Three high-temperature applications of candle filters are described here. 2 refs., 3 figs.

Lippert, T. [Westinghouse Science & Technology Center, Pittsburgh, PA (United States)

1997-05-01

221

Fluidized-bed filtration for particulate cleanup  

SciTech Connect

Successful development of advanced coal-fired power conversion systems often requires reliable and efficient gas stream-cleanup devices that can remove particulate and gaseous pollutants from high-temperature and high-pressure gas streams. A novel filter concept for particulate cleanup has been developed at the Morgantown Energy Technology Center (METC). The filter consists of a fine screened surface immersed in a fluidized bed of granular material. As the gas stream passes through the fluidized bed, a layer of fine granular material is deposited and packed at the screen surface, which provides a natural filter to separate the fine particles from the gas stream. Since the filtering media is the granular material supplied by the fluidized bed, the filter is not subjected to blinding. Cleaning the filter (if necessary) is much easier than with a ceramic filter because the inflowing gas, not the cohesive forces, maintains the filter media at the screen surface. Therefore, the screen surface can be readily cleaned by momentarily interrupting the gas flow. A two-dimensional fluidized-bed filter cold model was designed, constructed, and operated to explore the feasibility of this novel concept. The two-dimensional, transparent unit allowed clear observation of the general fluidized state of the granular material and the conditions under which fines are captured by the particle layer. A series of parametric tests was conducted to provide acceptable operating conditions for the model configuration. Preliminary results are presented in this paper. Effects of various parameters, such as superficial gas velocity, bed depth, particle size, and distance from the filter to the gas distributor, on filter behavior are characterized through differential pressure and differential pressure fluctuation data.

Mei, J.S.; Yue, P.C.; Halow, J.S.

1993-01-01

222

Fluid&ParticulateSystems 424514/2010  

E-print Network

/2010 Fluid&ParticulateSystems �A424514/2014 Fluid mechanics ­ re-wrap of basic principles januari 2014 �boFluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2014 Fluid&ParticulateSystems �A424514/2014 Fluid and Particulate systems 424514 /2014 BASIC PRINCIPLES / REVIEW COURSE OVERVIEW

Zevenhoven, Ron

223

MERCURY CONTROL WITH ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addressed Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and has been marketed as the Advanced Hybrid{trademark} filter by Gore. The Advanced Hybrid{trademark} filter combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The Advanced Hybrid{trademark} filter provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The Advanced Hybrid{trademark} filter also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the project was to demonstrate 90% total mercury control in the Advanced Hybrid{trademark} filter at a lower cost than current mercury control estimates. The approach included bench-scale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW (9000-acfm) scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control. An additional task was included in this project to evaluate mercury oxidation upstream of a dry scrubber by using mercury oxidants. This project demonstrated at the pilot-scale level a technology that provides a cost-effective technique to control mercury and, at the same time, greatly enhances fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution for improved fine particulate control combined with effective mercury control for a large segment of the U.S. utility industry as well as other industries.

Ye Zhuang; Stanley J. Miller

2005-05-01

224

Role of atmospheric ammonia in particulate matter formation in Houston during summertime  

E-print Network

Role of atmospheric ammonia in particulate matter formation in Houston during summertime Longwen 2013 Keywords: Ammonia Particulate matter Gas-particle partitioning Aerosol nucleation a b s t r a c reserved. 1. Introduction Ammonia (NH3) is widely present in the atmosphere due to many anthropogenic

225

Assessment of the 296-S-21 Stack Sampling Probe Location  

SciTech Connect

Tests were performed to assess the suitability of the location of the air sampling probe on the 296-S-21 stack according to the criteria of ANSI N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities. Pacific Northwest National Laboratory conducted most tests on a 3.67:1 scale model of the stack. CH2MHill also performed some limited confirmatory tests on the actual stack. The tests assessed the capability of the air-monitoring probe to extract a sample representative of the effluent stream. The tests were conducted for the practical combinations of operating fans and addressed: (1) Angular Flow--The purpose is to determine whether the velocity vector is aligned with the sampling nozzle. The average yaw angle relative to the nozzle axis should not be more than 20. The measured values ranged from 5 to 11 degrees on the scale model and 10 to 12 degrees on the actual stack. (2) Uniform Air Velocity--The gas momentum across the stack cross section where the sample is extracted should be well mixed or uniform. The uniformity is expressed as the variability of the measurements about the mean, the coefficient of variance (COV). The lower the COV value, the more uniform the velocity. The acceptance criterion is that the COV of the air velocity must be ?20% across the center two-thirds of the area of the stack. At the location simulating the sampling probe, the measured values ranged form 4 to 11%, which are within the criterion. To confirm the validity of the scale model results, air velocity uniformity measurements were made both on the actual stack and on the scale model at the test ports 1.5 stack diameters upstream of the sampling probe. The results ranged from 6 to 8% COV on the actual stack and 10 to 13% COV on the scale model. The average difference for the eight runs was 4.8% COV, which is within the validation criterion. The fact that the scale model results were slightly higher than the actual stack suggests that the other test results on the scale model are conservative relative to the actual stack. (3) Uniform Concentration of Tracer Gases--A uniform contaminant concentration in the sampling plane enables the extraction of samples that represent the true concentration. This was first tested using a tracer gas to represent gaseous effluents. The fan is a good mixer, so injecting the tracer downstream of the fans provides worst-case results. The acceptance criteria are that (1) the COV of the measured tracer gas concentration is ?20% across the center two-thirds of the sampling plane and (2) at no point in the sampling plane does the concentration vary from the mean by >30%. The results on the scale model at the point simulating the sampling probe ranged from 0.3 to 6 %COV, and the maximum single point deviation from the mean was -10%. (4) Uniform Concentration of Tracer Particles--Uniformity in contaminant concentration at the sampling probe was further demonstrated using tracer particles large enough to exhibit inertial effects. Particles of 10-?m aerodynamic diameter were used. The acceptance criterion is that the COV of particle concentration is ?20% across the center two-thirds of the sampling plane. The scale model results ranged form 2 to 9%. Based on these tests, the location of the air sampling probe on the 296-S-21 stack meets the requirements of the ANSI/HPS N13.1-1999 standard.

Glissmeyer, John A.

2006-09-08

226

Split stack blowout prevention system  

SciTech Connect

A blowout prevention system for an offshore structure positioned on the underwater bottom in a body of water which contains moving ice masses that could force the structure off location wherein a surface blowout preventer stack for conventional well control is connected to the upper end of a riser with the lower end of the riser being disconnectably connected to a subsurface blowout preventer stack which provides the necessary well control should the structure be forced off location. The subsurface stack is positioned on a wellhead located in a chamber in the subsea bottom and is disconnectably connected to the riser so that the riser may be quickly removed from the subsea bottom should the structure be forced off location.

Crager, B.L.; Ray, D.R.; Steddum, R.E.

1980-03-18

227

Airborne Particulate Threat Assessment  

SciTech Connect

Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our findings and APICD Gen II subsystems for automated collection, deposition and detection of ambient particulate matter. Key findings from the APTA Program include: Ambient biological PM taxonomy; Demonstration of key subsystems needed for autonomous bioaerosol detection; System design; Efficient electrostatic collection; Automated bioagent recognition; Raman analysis performance validating Td<9 sec; Efficient collection surface regeneration; and Development of a quantitative bioaerosol defection model. The objective of the APTA program was to advance the state of our knowledge of ambient background PM composition. Operation of an automated aerosol detection system was enhanced by a more accurate assessment of background variability, especially for sensitive and specific sensing strategies like Raman detection that are background-limited in performance. Based on this improved knowledge of background, the overall threat detection performance of Raman sensors was improved.

Patrick Treado; Oksana Klueva; Jeffrey Beckstead

2008-12-31

228

Anharmonic stacking in supercoiled DNA.  

PubMed

Multistep denaturation in a short circular DNA molecule is analyzed by a mesoscopic Hamiltonian model which accounts for the helicoidal geometry. Computation of melting profiles by the path integral method suggests that stacking anharmonicity stabilizes the double helix against thermal disruption of the hydrogen bonds. Twisting is essential in the model to capture the importance of nonlinear effects on the thermodynamical properties. In a ladder model with zero twist, anharmonic stacking scarcely affects the thermodynamics. Moderately untwisted helices, with respect to the equilibrium conformation, show an energetic advantage against the overtwisted ones. Accordingly moderately untwisted helices better sustain local fluctuational openings and make more unlikely the thermally driven complete strand separation. PMID:22495298

Zoli, Marco

2012-05-16

229

Colorimetric gas dosimeter  

SciTech Connect

A gas dosimeter comprises a stack of porous sheets, impregnated with a reagent that changes color on contact with the gas to be determined, contained in a housing which has an opening to expose one end of the stack to the atmosphere to be tested. The gas to be determined penetrates by diffusion the layers of porous sheets, causing the sheets in the stack to change color sequentially from the end of the stack exposed to the atmosphere. The degree of penetration through the layers of porous sheets is a function of dosage exposure. The housing may be transparent with each superposed sheet in the stack being larger than the adjacent underlying sheet, so that each sheet is visible through the housing endwall.

McConnaughey, P.W.; McKee, E.S.

1984-10-23

230

Flue gas desulfurization\\/Advances in SOâ stack gas scrubbing  

Microsoft Academic Search

A survey shows that none of the emerging sulfur dioxide removal technologies appear to have an overriding cost advantage over present generation conventional boiler\\/FGD systems. Of the emerging technologies, atmospheric fluidized bed combustion appears the most attractive because it is relatively simple in concept and offers the promise of reasonable annual revenue requirements. Other than a moderate increase in efficiency,

Princiotta

1978-01-01

231

Electrically heated particulate filter with reduced stress  

DOEpatents

A system comprises a particulate matter (PM) filter comprising an inlet for receiving exhaust gas. A zoned heater is arranged in the inlet and comprises a resistive heater comprising N zones, where N is an integer greater than one. Each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates others of the N zones.

Gonze, Eugene V.

2013-03-05

232

Experimental performance evaluation of two stack sampling systems in a plutonium facility  

SciTech Connect

The evaluation of two routine stack sampling systems at the Z-Plant plutonium facility operated by Rockwell International for USERDA is part of a larger study, sponsored by Rockwell and conducted by Battelle, Pacific Northwest Laboratories, of gaseous effluent sampling systems. The gaseous effluent sampling systems evaluated are located at the main plant ventilation stack (291-Z-1) and at a vessel vent stack (296-Z-3). A preliminary report, which was a paper study issued in April 1976, identified many deficiencies in the existing sampling systems and made recommendations for corrective action. The objectives of this experimental evaluation of those sampling systems were as follows: Characterize the radioactive aerosols in the stack effluents; Develop a tracer aerosol technique for validating particulate effluent sampling system performance; Evaluate the performance of the existing routine sampling systems and their compliance with the sponsor`s criteria; and Recommend corrective action where required. The tracer aerosol approach to sampler evaluation was chosen because the low concentrations of radioactive particulates in the effluents would otherwise require much longer sampling times and thus more time to complete this evaluation. The following report describes the sampling systems that are the subject of this study and then details the experiments performed. The results are then presented and discussed. Much of the raw and finished data are included in the appendices.

Glissmeyer, J.A.

1992-04-01

233

Influences on the Particle Size Distribution of Diesel Particulate Emissions  

Microsoft Academic Search

Particulates give great concern for mankind health. Especially the nano size particles are under discussion. Therefore, the particle size distribution from the combustion chamber to tail pipe emissions are of great interest. With the aim of scanning mobility particle sizer the number weighted particle size distributions were measured in the combustion chamber as well as in the exhaust gas up

Gerhard Lepperhoff

2001-01-01

234

Catalytic oxidation of diesel particulates with base metal oxides  

Microsoft Academic Search

Reduction of emissions from diesel engines using novel flow-through oxidation catalysts containing base metal oxides has been demonstrated. The soluble organic fraction (SOF) of the particulates can be converted and gas phase hydrocarbons can be removed via the proper choice of oxides. Low levels of platinum on the catalysts also compliment HC and CO conversion without leading to “sulfate-make”. Catalyst

K. E. Voss; J. K. Lampert; R. J. Farrauto; G. W. Rice; A. Punke; R. Krohn

1995-01-01

235

REGIONAL PARTICULATE MODEL - 1. MODEL DESCRIPTION AND PRELIMINARY RESULTS  

EPA Science Inventory

The gas-phase chemistry and transport mechanisms of the Regional Acid Deposition Model have been modified to create the Regional Particulate Model, a three-dimensional Eulerian model that simulates the chemistry, transport, and dynamics of sulfuric acid aerosol resulting from pri...

236

Multilayer Piezoelectric Stack Actuator Characterization  

NASA Technical Reports Server (NTRS)

Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

2008-01-01

237

Multibeam collimator uses prism stack  

NASA Technical Reports Server (NTRS)

Optical instrument creates many divergent light beams for surveying and machine element alignment applications. Angles and refractive indices of stack of prisms are selected to divert incoming laser beam by small increments, different for each prism. Angles of emerging beams thus differ by small, precisely-controlled amounts. Instrument is nearly immune to vibration, changes in gravitational force, temperature variations, and mechanical distortion.

Minott, P. O.

1981-01-01

238

STACK SAMPLING FOR ORGANIC EMISSIONS  

EPA Science Inventory

The paper reviews some of the more important principles involved in stack sampling for organics, briefly describes and discusses recently developed equipment, and points out a few of the more serious pitfalls. Extensive references are provided, many of which are often overlooked ...

239

Stacking Bagged and Dagged Models  

Microsoft Academic Search

In this paper, we investigate the method of stacked generalization in combining models derived from different subsets of a training dataset by a single learning algorithm, as well as different algorithms. The simplest way to combine predictions from competing models is majority vote, and the effect of the sampling regime used to generate training subsets has already been studied in

Kai Ming Ting; Ian H. Witten

1997-01-01

240

POLYMERIC INTERFACES FOR STACK MONITORING  

EPA Science Inventory

Research has been performed on the use of polymeric interfaces for in situ continuous stack monitoring of gaseous pollutants. Permeabilities of candidate interface materials to SO2 were measured at temperatures from ambient to 200C, and the results were used to design interfaces ...

241

Progress Update: Stack Project Complete  

ScienceCinema

Progress update from the Savannah River Site. The 75 foot 293 F Stack, built for plutonium production, was cut down to size in order to prevent injury or release of toxic material if the structure were to collapse due to harsh weather.

Cody, Tom

2012-06-14

242

Manifold seal structure for fuel cell stack  

DOEpatents

The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

Collins, William P. (South Windsor, CT)

1988-01-01

243

Sauget Plant Flare Gas Reduction Project  

E-print Network

Empirical analysis of stack gas heating value allowed the Afton Chemical Corporation Sauget Plant to reduce natural gas flow to its process flares by about 50% while maintaining the EPA-required minimum heating value of the gas streams....

Ratkowski, D. P.

2007-01-01

244

Particulate erosion mechanisms  

NASA Technical Reports Server (NTRS)

Particulate damage and erosion of ductile metals are today plaguing design and field engineers in diverse fields of engineering and technology. It was found that too many models and theories were proposed leading to much speculation from debris analysis and failure mechanism postulations. Most theories of solid particle erosion are based on material removal models which do not fully represent the actual physical processes of material removal. The various mechanisms proposed thus far are: melting, low-cycle fatigue, extrusion, delamination, shear localization, adhesive material transfer, etc. The experimental data on different materials highlighting the observed failure modes of the deformation and cutting wear processes using optical and scanning electron microscopy are presented. The most important mechanisms proved from the experimental observations of the specimens exposed to both spherical and angular particles are addressed, and the validity of the earlier theories discussed. Both the initial stages of damage and advanced stages of erosion were studied to gain a fundamental understanding of the process.

Veerabhadrarao, P.; Buckley, D. H.

1983-01-01

245

30 CFR 77.302 - Bypass stacks.  

Code of Federal Regulations, 2011 CFR

...WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.302 Bypass stacks. Thermal dryer systems shall include a bypass stack, relief...automatic venting which will permit gases from the dryer heating unit to bypass the heating chamber...

2011-07-01

246

30 CFR 77.302 - Bypass stacks.  

Code of Federal Regulations, 2010 CFR

...WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.302 Bypass stacks. Thermal dryer systems shall include a bypass stack, relief...automatic venting which will permit gases from the dryer heating unit to bypass the heating chamber...

2010-07-01

247

30 CFR 77.302 - Bypass stacks.  

Code of Federal Regulations, 2014 CFR

...WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.302 Bypass stacks. Thermal dryer systems shall include a bypass stack, relief...automatic venting which will permit gases from the dryer heating unit to bypass the heating chamber...

2014-07-01

248

30 CFR 77.302 - Bypass stacks.  

Code of Federal Regulations, 2012 CFR

...WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.302 Bypass stacks. Thermal dryer systems shall include a bypass stack, relief...automatic venting which will permit gases from the dryer heating unit to bypass the heating chamber...

2012-07-01

249

30 CFR 77.302 - Bypass stacks.  

Code of Federal Regulations, 2013 CFR

...WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.302 Bypass stacks. Thermal dryer systems shall include a bypass stack, relief...automatic venting which will permit gases from the dryer heating unit to bypass the heating chamber...

2013-07-01

250

Categorical properties of topological and differentiable stacks  

Microsoft Academic Search

The focus of this PhD research is on the theory of topological and differentiable stacks. There are two main themes of this research. The first, is the creation of the theory of compactly generated stacks, which solve many categorical shortcomings of the theory of classical topological stacks. In particular, they are Cartesian closed. Secondly, this thesis develops the theory of

D. J. Carchedi

2011-01-01

251

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking  

E-print Network

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking Tom Aldcroft SAO/CXC #12;X-ray Stacking 2008 to gamma rays Detection efficiency of a source class (e.g. obscured active galactic nuclei) is often best analysis for a sample Stacking ­ mean properties of sample Chandra X-ray data (faint point sources

Wolfe, Patrick J.

252

Small Scheme Stack: A Scheme TCP/IP Stack Targeting Small Embedded Applications  

E-print Network

often been used to this end, requiring compact stacks to be implemented as regular ones are too large for embedded sys- tems. Traditionally, compact stacks such as uIP [4] have been im- plemented in C. Here we report on our experience in implement- ing S3 ("Small Scheme Stack"), a compact TCP/IP stack written

Feeley, Marc

253

Module level thermal performance characterization and enhancement of chip stack and package stack memory devices  

Microsoft Academic Search

Technological advances driven by the DRAM market demands resulted in thermal challenges arising from increasing power and decreasing space for cooling. This is exacerbated by the packaging of multiple devices within the same footprint based on die stacking or package stacking. In view of the thermal concerns, we conducted a comprehensive thermal study of chip stack and package stack devices

Siew Hoon Ore; W. H. Zhu; W. L. Yuan; N. Suthiwongsunthorn

2010-01-01

254

Micromechanics for particulate reinforced composites  

NASA Technical Reports Server (NTRS)

A set of micromechanics equations for the analysis of particulate reinforced composites is developed using the mechanics of materials approach. Simplified equations are used to compute homogenized or equivalent thermal and mechanical properties of particulate reinforced composites in terms of the properties of the constituent materials. The microstress equations are also presented here to decompose the applied stresses on the overall composite to the microstresses in the constituent materials. The properties of a 'generic' particulate composite as well as those of a particle reinforced metal matrix composite are predicted and compared with other theories as well as some experimental data. The micromechanics predictions are in excellent agreement with the measured values.

Murthy, Pappu L. N.; Goldberg, Robert K.; Mital, Subodh K.

1996-01-01

255

Stacked triangular lattice: Percolation properties  

NASA Astrophysics Data System (ADS)

The stacked triangular lattice has the shape of a triangular prism. In spite of being considered frequently in solid-state physics and materials science, its percolation properties have received little attention. We investigate several nonuniversal percolation properties on this lattice using Monte Carlo simulation. We show that the percolation threshold is pcbond=0.18602±0.00002 for bonds and pcsite=0.26240±0.00005 for sites. The number of clusters at the threshold per site is ncbond=0.28458±0.00005 and ncsite=0.03998±0.00005. The stacked triangular lattice is a convenient choice to study the RGB model [Schrenk , Sci. Rep.10.1038/srep00751 2, 751 (2012)]. We present results on this model and its scaling behavior at the percolation threshold.

Schrenk, K. J.; Araújo, N. A. M.; Herrmann, H. J.

2013-03-01

256

Microchip electrophoresis with sample stacking.  

PubMed

A fused quartz microchip with a serpentine column geometry is fabricated to perform rapid microchip electrophoresis of dansylated amino acids. A 67 mm separation column is constructed in a 7 x 10 mm area on a quartz substrate using standard photolithographic, etching and deposition techniques. Buffer and sample flows within the channel manifold are precisely controlled through potentials applied to the reservoirs. To enhance the detection limits, a stacking injection technique is used to concentrate the sample at the inlet of the separation column. The stacked injections exhibit high reproducibility (2.1% relative standard deviation in peak area). Using a separation length of 67 mm and a separation field strength of 1100 V/cm, separations are performed in < or = 15 s generating approximately 40,000 theoretical plates. PMID:7588514

Jacobson, S C; Ramsey, J M

1995-04-01

257

PRECISION COSMOGRAPHY WITH STACKED VOIDS  

SciTech Connect

We present a purely geometrical method for probing the expansion history of the universe from the observation of the shape of stacked voids in spectroscopic redshift surveys. Our method is an Alcock-Paczynski (AP) test based on the average sphericity of voids posited on the local isotropy of the universe. It works by comparing the temporal extent of cosmic voids along the line of sight with their angular, spatial extent. We describe the algorithm that we use to detect and stack voids in redshift shells on the light cone and test it on mock light cones produced from N-body simulations. We establish a robust statistical model for estimating the average stretching of voids in redshift space and quantify the contamination by peculiar velocities. Finally, assuming that the void statistics that we derive from N-body simulations is preserved when considering galaxy surveys, we assess the capability of this approach to constrain dark energy parameters. We report this assessment in terms of the figure of merit (FoM) of the dark energy task force and in particular of the proposed Euclid mission which is particularly suited for this technique since it is a spectroscopic survey. The FoM due to stacked voids from the Euclid wide survey may double that of all other dark energy probes derived from Euclid data alone (combined with Planck priors). In particular, voids seem to outperform baryon acoustic oscillations by an order of magnitude. This result is consistent with simple estimates based on mode counting. The AP test based on stacked voids may be a significant addition to the portfolio of major dark energy probes and its potentialities must be studied in detail.

Lavaux, Guilhem [Department of Physics, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Wandelt, Benjamin D. [UPMC Univ Paris 06, UMR 7095, Institut d'Astrophysique de Paris, 98 bis, boulevard Arago, 75014 Paris (France)

2012-08-01

258

Electrically heated particulate filter restart strategy  

DOEpatents

A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2011-07-12

259

Membership Testing: Removing Extra Stacks from Multi-stack Pushdown Automata  

Microsoft Academic Search

We show that fixed membership testing for many interesting subclasses of multi-pushdown machines is no harder than for pushdowns\\u000a with single stack. The models we consider are MVPA, OVPA and MPDA, which have all been defined and studied in the past.\\u000a \\u000a Multi-stack pushdown automata, MPDA, have ordered stacks with pop access restricted to the stack-top of the first non-empty stack.

Nutan Limaye; Meena Mahajan

2009-01-01

260

Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report IV.D Fuel Cell Stack Subsystem and Components  

E-print Network

electrolyte membrane (PEM) fuel cell stack system comprised of a PEM fuel cell stack and the supporting gas substitutes for the internal combustion engine (ICE) in automotive applications only when their benefits this contract was designed to accept reformed gasoline from a fuel processor. Development of the fuel processor

261

Lightweight Stacks of Direct Methanol Fuel Cells  

NASA Technical Reports Server (NTRS)

An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

Narayanan, Sekharipuram; Valdez, Thomas

2004-01-01

262

Roadside measurements of particulate matter size distribution  

NASA Astrophysics Data System (ADS)

Roadside measurements were performed in order to document the size distribution of particulate matter (PM) under dilution conditions similar to those found in real world. These activities covered measurements at engine test beds, at different locations in a road tunnel as well as in an urban environment. In order to get a clear picture of the evolution of the PM in different size classes, the in-tunnel locations ranged from curb-side to different locations inside the exhaust air system. Additional measurements were performed in the ambient air at curb-side at a street crossing as well as in urban background. At those times when heavy traffic occurs, tunnel measurements show size distributions similar to those derived from engine/vehicle measurements. During times with little traffic the size distributions are closer to those recorded in ambient air. As soon as the traffic load increases the size distribution changes, due to rapid coagulation of the smallest particles with the accumulation mode. As the travel time of the particles through the tunnel and up the stacks is very long "aging" effects could be observed. Thus, these spectra are quite different from ambient measurements in urban air, especially in the region above 30-40 nm.

Sturm, Peter J.; Baltensperger, Urs; Bacher, Michael; Lechner, Bernhard; Hausberger, Stefan; Heiden, Bernhard; Imhof, David; Weingartner, Ernest; Prevot, Andre S. H.; Kurtenbach, Ralf; Wiesen, Peter

263

Electrical diesel particulate filter (DPF) regeneration  

DOEpatents

An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

Gonze, Eugene V; Ament, Frank

2013-12-31

264

Hydrocarbon-enhanced particulate filter regeneration via microwave ignition  

DOEpatents

A regeneration method for a particulate filter includes estimating a quantity of particulate matter trapped within the particulate filter, comparing the quantity of particulate matter to a predetermined quantity, heating at least a portion of the particulate filter to a combustion temperature of the particulate matter, and introducing hydrocarbon fuel to the particulate filter. The hydrocarbon fuel facilitates combustion of the particulate matter to regenerate the particulate filter.

Gonze, Eugene V. (Pinckney, MI); Brown, David B. (Brighton, MI)

2010-02-02

265

Elevated exhaust temperature, zoned, electrically-heated particulate matter filter  

DOEpatents

A system includes an electrical heater and a particulate matter (PM) filter that is arranged one of adjacent to and in contact with the electrical heater. A control module selectively increases an exhaust gas temperature of an engine to a first temperature and that initiates regeneration of the PM filter using the electrical heater while the exhaust gas temperature is above the first temperature. The first temperature is greater than a maximum exhaust gas temperature at the PM filter during non-regeneration operation and is less than an oxidation temperature of the PM.

Gonze, Eugene V [Pinckney, MI; Bhatia, Garima [Bangalore, IN

2012-04-17

266

Assaying baseline status of particulate laden polyaromatic hydrocarbon for a grass root level industrial project  

SciTech Connect

A study of particulate laden polyaromatic hydrocarbon was conducted at 13 selected locations in a 10 km radial distance of a proposed site for a grass root level industry. Suspended particulate matter samples were continuously monitored for 24 h over a period of 3 months. The Polyaromatic Hydrocarbons (PAHs) were extracted from the particulate samples and analysed using Gas Chromatograph-Mass Spectrometer. Limit of Quantification was also established for individual PAHs. Coal combustion and traffic emission were the major contributors for PAHs in the region. The relative contribution of 2, 3, 4, 5, and 6 ring PAHs in particulates of different sampling sites was also investigated and it is observed that 4 ring (29.76%) and 5 ring (29.06%) compounds are prominent in the particulates measured in the region.

Pandya, G.H.; Chatterjee, N.; Singh, R.; Kashyap, S.; Saheb, S.P.; Wate, S.R. [National Environmental Engineering Research Institute, Nagpur (India)

2009-02-15

267

Photogrammetric Technique for Timber Stack Volume Contol  

NASA Astrophysics Data System (ADS)

The problem of accurate log volume measurement is a very important, especially in case of seaport volume control where logs are put in a huge stack of hundred meters length and a time for volume control is strongly restricted. Current technology of volume control use manual means such as measuring tape, so the process of measurement is rather inaccurate and time consuming. To estimate the volume of timber stack its frontal area is measured and some control parts of a stack are used for stacking coefficient (wood density in a stack) determination. Non-contact vision based technique is proposed for manual measurements substituting. The developed methods are implemented in portable photogrammetric system for stack parameters measuring and documenting.

Knyaz, V. A.; Maksimov, A. A.

2014-08-01

268

Method for inhibiting corrosion in particulate zinc  

SciTech Connect

A method is described for the inhibition of corrosion in particulate zinc, which comprises the step of subjecting said zinc in the form of an alkaline slurry to treatment by a corrosion inhibiting effective amount of a corrosion inhibitor which is at least one oxide selected from the group consisting of oxides of antimony, bismuth, cadmium, gallium, indium, lead, mercury, thallium and tin, wherein zinc has been obtained by an electrolytic process for regeneration of zinc in an at least partially spent slurry for use in metal-air batteries which slurry comprises an admixture of at least components (a) and (b), of the following components (a), (b), (c), (d), (e), (f) and (g): (a) zinc which has been at least partly oxidized to an oxidation product selected from zinc oxide and zincates; (b) an aqueous solution of at least one Group 1a metal comprising anions selected from the group consisting of hydroxide and zincate; (c) an inorganic inhibitor ingredient effective to inhibit an interaction of zinc and at least one Group 1a metal hydroxide in the aqueous solution, which would otherwise result in an evolution of hydrogen gas; (d) a gelling agent; (e) a filler selected from the group consisting of particulate and fibrous fillers; (f) a labelling agent; (g) a dissolved electrolyte extender.

Goldstein, J.; Meitav, A,; Lezion, R.; Kravitz, M.

1993-08-03

269

Metal gate stack plasma patterning studies  

Microsoft Academic Search

Summary form only given. The presentation will focus on the dry etch studies required to pattern poly-Si\\/metal\\/SiON and poly-Si\\/metal\\/high-k gate stacks that might be used in the forthcoming technological nodes. As usual, two key challenges for dry etching metal gate stacks are selectivity and profile control. Smaller and smaller dimensions with more and more complex gate stacks with new materials

L. Vallier; G. Cunge; T. Chevolleau; E. Richard; O. Joubert

2006-01-01

270

Incoherent vertical ion losses during multiturn stacking cooling beam injection  

NASA Astrophysics Data System (ADS)

The efficiency of the multiturn ion injection with electron cooling depends on two parameters, namely, cooling efficiency and ion lifetime. The lifetime of freshly injected ions is usually shorter than the lifetime of strongly cooled stacked ions. Freshly injected ions are lost in the vertical direction because the vertical acceptance of the synchrotron is usually a few times smaller than the horizontal acceptance. Incoherent vertical losses of freshly injected ions arise from their multiple scattering by residual gas atoms and transverse diffusion caused by stack noise. Reduced ion lifetime limits the multiturn injection efficiency. Analytical estimations and BETACOOL-based numerical evaluations of the vertical ion losses during multiturn injection are presented in comparison with the experimental data obtained at the HIMAC synchrotron and the S-LSR storage ring.

Syresin, E. M.

2014-07-01

271

String compactifications on Calabi Yau stacks  

NASA Astrophysics Data System (ADS)

In this paper we study string compactifications on Deligne-Mumford stacks. The basic idea is that all such stacks have presentations to which one can associate gauged sigma models, where the group gauged need be neither finite nor effectively-acting. Such presentations are not unique, and lead to physically distinct gauged sigma models; stacks classify universality classes of gauged sigma models, not gauged sigma models themselves. We begin by defining and justifying a notion of "Calabi-Yau stack", recall how one defines sigma models on (presentations of) stacks, and calculate of physical properties of such sigma models, such as closed and open string spectra. We describe how the boundary states in the open string B model on a Calabi-Yau stack are counted by derived categories of coherent sheaves on the stack. Along the way, we describe numerous tests that IR physics is presentation-independent, justifying the claim that stacks classify universality classes. String orbifolds are one special case of these compactifications, a subject which has proven controversial in the past; however we resolve the objections to this description of which we are aware. In particular, we discuss the apparent mismatch between stack moduli and physical moduli, and how that discrepancy is resolved.

Pantev, Tony; Sharpe, Eric

2006-01-01

272

Gas sensor  

DOEpatents

A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

2014-09-09

273

Compactified Picard stacks over the moduli stack of stable curves with marked points  

Microsoft Academic Search

In this paper we give a construction of algebraic (Artin) stacks endowed with a modular map onto the moduli stack of stable curves of genus g with n marked points. The stacks we construct are smooth, irreducible and have dimension 4g?3+n, yielding a geometrically meaningful compactification of the universal Picard stack parametrizing n-pointed smooth curves together with a line bundle.

Margarida Melo

2011-01-01

274

Effect of various stack parameters on temperature rise in molten carbonate fuel cell stack operation  

Microsoft Academic Search

A mathematical stack model is used to predict the temperature at a constant-load operation of molten-carbonate fuel cell stacks. The validity of the model is proved by a comparison with measured temperature data obtained from the operation of a 5-kW test stack. The model is applied extensively for the simulation of temperature profiles in a larger stack to analyze the

Joon-Ho Koh; Byoung Sam Kang; Hee Chun Lim

2000-01-01

275

Particulate emissions from diesel engines: correlation between engine technology and emissions.  

PubMed

In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted.Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions.Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission. PMID:24606725

Fiebig, Michael; Wiartalla, Andreas; Holderbaum, Bastian; Kiesow, Sebastian

2014-01-01

276

Particulate emissions from diesel engines: correlation between engine technology and emissions  

PubMed Central

In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted. Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions. Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission. PMID:24606725

2014-01-01

277

Overlap zoned electrically heated particulate filter  

DOEpatents

A system includes a particulate matter (PM) filter that includes an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than or equal to one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

Gonze, Eugene V [Pinckney, MI; Chapman, Mark R [Brighton, MI

2011-07-19

278

Control system for diesel particulate trap regeneration system  

Microsoft Academic Search

This patent describes a method of regenerating an exhaust gas particulate trap in an exhaust system for an internal combustion engine. It comprises measuring the air\\/fuel ratio of the internal combustion engine, generating a signal representing a commanded value of the air\\/fuel ratio signal corresponding to an air\\/fuel ratio with sufficient excess air to burn the particles stored in the

P. M. Stiglic; B. C. Gabelman; J. A. Hardy

1991-01-01

279

Application of thermal analysis and photoelectron spectroscopy for the characterization of particulate matter  

SciTech Connect

Photoelectron spectroscopy (ESCA) and thermal evolved gas analysis (EGA) have been applied to characterize sulfur- and nitrogen-containing species in atmospheric particulate matter. Particulate amines and amides previously identified only by ESCA have been detected by EGA, a bulk method, for the first time. EGA and ESCA results suggest the existence of a sulfate similar to ammonium sulfate but with some of the ammonium ions replaced by a charged organic nitrogen complex. 8 references, 8 figures.

Dod, R.L.; Novakov, T.

1982-01-01

280

Field testing of particulate matter continuous emission monitors at the DOE Oak Ridge TSCA incinerator. Toxic Substances Control Act.  

PubMed

A field study to evaluate the performance of three commercially available particulate matter (PM) continuous emission monitors (CEMs) was conducted in 1999-2000 at the US Department of Energy (DOE) Toxic Substances Control Act (TSCA) Incinerator. This study offers unique features that are believed to enhance the collective US experience with PM CEMs. The TSCA Incinerator is permitted to treat PCB-contaminated RCRA hazardous low-level radioactive wastes. The air pollution control system utilizes MACT control technology and is comprised of a rapid quench, venturi scrubber, packed bed scrubber, and two ionizing wet scrubbers in series, which create a saturated flue gas that must be conditioned by the CEMs prior to measurement. The incinerator routinely treats a wide variety of wastes including high and low BTU organic liquids, aqueous, and solid wastes. The various possible combinations for treating liquid and solid wastes may present a challenge in establishing a single, acceptable correlation relationship for individual CEMs. The effect of low-level radioactive material present in the waste is a unique site-specific factor not evaluated in previous tests. The three systems chosen for evaluation were two beta gauge devices and a light scattering device. The performance of the CEMs was evaluated using the requirements in draft Environmental Protection Agency (EPA) Performance Specification 11 (PS11) and Procedure 2. The results of Reference Method 5i stack tests for establishing statistical correlations between the reference method data and the CEMs responses are discussed. PMID:12099501

Dunn, James E; Davis, Wayne T; Calcagno, James A; Allen, Marshall W

2002-01-01

281

PARTICULATE EMISSION MEASUREMENTS FROM CONTROLLED CONSTRUCTION ACTIVITIES  

EPA Science Inventory

The report summarized the results of field testing of the effectiveness of control measures for sources of fugitive particulate emissions found at construction sites. The effectiveness of watering temporary, unpaved travel surfaces on emissions of particulate matter with aerodyna...

282

Cross-flow, filter-sorbent catalyst for particulate, SO sub 2 and NO sub x control  

SciTech Connect

This report describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

Benedek, K. (Little (Arthur D.), Inc., Cambridge, MA (United States)); Flytzani-Stephanopoulos, M. (Massachusetts Inst. of Tech., Cambridge, MA (United States))

1991-08-01

283

Cross-flow filter-sorbent catalyst for particulate, SO sub 2 and NO sub x control  

SciTech Connect

This report describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

Not Available

1990-05-01

284

Process for particulate removal from coal liquids  

DOEpatents

Suspended solid particulates are removed from liquefied coal products by first subjecting such products to hydroclone action for removal in the underflow of the larger size particulates, and then subjecting the overflow from said hydroclone action, comprising the residual finer particulates, to an electrostatic field in an electrofilter wherein such finer particulates are deposited in the bed of beads of dielectric material on said filter. The beads are periodically cleaned by backwashing to remove the accumulated solids.

Rappe, Gerald C. (Macungie, PA)

1983-01-01

285

Device for equalizing molten electrolyte content in a fuel cell stack  

DOEpatents

A device for equalizing the molten electrolyte content throughout the height of a fuel cell stack is disclosed. The device includes a passageway for electrolyte return with electrolyte wettable wicking material in the opposite end portions of the passageway. One end portion is disposed near the upper, negative end of the stack where electrolyte flooding occurs. The second end portion is placed near the lower, positive end of the stack where electrolyte is depleted. Heating means are provided at the upper portion of the passageway to increase electrolyte vapor pressure in the upper wicking material. The vapor is condensed in the lower passageway portion and conducted as molten electrolyte in the lower wick to the positive end face of the stack. An inlet is provided to inject a modifying gas into the passageway and thereby control the rate of electrolyte return.

Smith, J.L.

1985-12-23

286

Device for equalizing molten electrolyte content in a fuel cell stack  

DOEpatents

A device for equalizing the molten electrolyte content throughout the height of a fuel cell stack is disclosed. The device includes a passageway for electrolyte return with electrolyte wettable wicking material in the opposite end portions of the passageway. One end portion is disposed near the upper, negative end of the stack where electrolyte flooding occurs. The second end portion is placed near the lower, positive end of the stack where electrolyte is depleted. Heating means are provided at the upper portion of the passageway to increase electrolyte vapor pressure in the upper wicking material. The vapor is condensed in the lower passageway portion and conducted as molten electrolyte in the lower wick to the positive end face of the stack. An inlet is provided to inject a modifying gas into the passageway and thereby control the rate of electrolyte return.

Smith, James L. (Lemont, IL)

1987-01-01

287

Stacked optical antennas Dieter W. Pohl,1  

E-print Network

Stacked optical antennas Dieter W. Pohl,1 Sergio G. Rodrigo,2 and Lukas Novotny2,a 1 Institute; published online 13 January 2011 We propose and analyze a stacked optical antenna SOA . It is characterized in microscopy. © 2011 American Institute of Physics. doi:10.1063/1.3541544 Optical antennas are devices

Novotny, Lukas

288

Interconnections For Stacked Parallel Computer Modules  

NASA Technical Reports Server (NTRS)

Concept for interconnecting modules in parallel computers leads to cheaper, smaller, lighter, lower-power computing systems for aerospace, industrial, business, and consumer applications. Computer modules stacked and interconnected in various configurations. Connections among stacks controlled by switching within gateways and/or by addresses on buses.

Johannesson, Richard T.

1996-01-01

289

Shear testing of stack bonded masonry  

Microsoft Academic Search

Stack bonded masonry is scarcely used in practice, except for aesthetic reasons. Nevertheless, a regular array of units allows placing reinforcement in the joints, which can be of major importance for masonry shell roofs, as proposed by Eladio Dieste. In order to contribute to the knowledge of the behavior of stack bonded masonry under shear loading, which seems not to

P. B. Lourenço; J. O. Barros; J. T. Oliveira

2004-01-01

290

Effective Stack Design in Air Pollution Control.  

ERIC Educational Resources Information Center

Stack design problems fall into two general caterories--(1) those of building re-entry, and (2) those of general area pollution. Extensive research has developed adequate information, available in the literature, to permit effective stack design. A major roadblock to effective design has been the strong belief by architects and engineers that high…

Clarke, John H.

1968-01-01

291

Opacity of nitrogen dioxide stack plumes  

Microsoft Academic Search

Removal of the NOâ from process off-gases would enable the Purex Plant to comply with the opacity standards for air pollution control. However, a relationship between stack opacity and NOâ content of the stack gases is needed in order to implement a cost effective NOâ control method. A test was conducted in which nitrogen dioxide (NOâ) was injected into a

Evoniuk

1979-01-01

292

A novel optical scattering collection system for particulate monitoring applications  

SciTech Connect

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.

Bernacki, B.E.; Miller, A.C. Jr. [Oak Ridge National Lab., TN (United States); Nuspliger, R.J. [Environmental Systems Corp., Knoxville, TN (United States)

1996-05-01

293

Wind induced vibration of a stack  

SciTech Connect

A stack supported by guy wires at four levels is subjected to large-amplitude oscillations when the wind speed is over 15 m/s. The excitation mechanisms are identified based on scoping calculations, analytical prediction using a finite element code, and observation of the stack/wire response. The stack is determined to be excited by vortex shedding. Once lock-in resonance occurs, the guy wires are excited by the transverse motion of the stack. Large-amplitude oscillations of the guy wires are due to parametric resonance. Several methods are recommended to alleviate vibrational problem for short-term and long-term solutions. A new stack which is modified based on the results of this study is not subjected to any unacceptable oscillations.

Chen, S.S.; Cai, Y.

1992-12-01

294

Wind induced vibration of a stack  

SciTech Connect

A stack supported by guy wires at four levels is subjected to large-amplitude oscillations when the wind speed is over 15 m/s. The excitation mechanisms are identified based on scoping calculations, analytical prediction using a finite element code, and observation of the stack/wire response. The stack is determined to be excited by vortex shedding. Once lock-in resonance occurs, the guy wires are excited by the transverse motion of the stack. Large-amplitude oscillations of the guy wires are due to parametric resonance. Several methods are recommended to alleviate vibrational problem for short-term and long-term solutions. A new stack which is modified based on the results of this study is not subjected to any unacceptable oscillations.

Chen, S.S.; Cai, Y.

1992-01-01

295

Dynamic behaviour of SOFC short stacks  

NASA Astrophysics Data System (ADS)

Electrical output behaviour obtained on solid oxide fuel cell stacks, based on planar anode supported cells (50 or 100 cm 2 active area) and metallic interconnects, is reported. Stacks (1-12 cells) have been operated with cathode air and anode hydrogen flows between 750 and 800 °C operating temperature. At first polarisation, an activation phase (increase in power density) is typically observed, ascribed to the cathode but not clarified. Activation may extend over days or weeks. The materials are fairly resistant to thermal cycling. A 1-cell stack cycled five times in 4 days at heating/cooling rates of 100-300 K h -1, showed no accelerated degradation. In a 5-cell stack, open circuit voltage (OCV) of all cells remained constant after three full cycles (800-25 °C). Power output is little affected by air flow but markedly influenced by small fuel flow variation. Fuel utilisation reached 88% in one 5-cell stack test. Performance homogeneity between cells lay at ±4-8% for three different 5- or 6-cell stacks, but was poor for a 12-cell stack with respect to the border cells. Degradation of a 1-cell stack operated for 5500 h showed clear dependence on operating conditions (cell voltage, fuel conversion), believed to be related to anode reoxidation (Ni). A 6-cell stack (50 cm 2 cells) delivering 100 W el at 790 °C (1 kW el L -1 or 0.34 W cm -2) went through a fuel supply interruption and a thermal cycle, with one out of the six cells slightly underperforming after these events. This cell was eventually responsible (hot spot) for stack failure.

Molinelli, Michele; Larrain, Diego; Autissier, Nordahl; Ihringer, Raphaël; Sfeir, Joseph; Badel, Nicolas; Bucheli, Olivier; Van herle, Jan

296

Development of a size-fractionating stack sampler for collection of particulate matter  

E-print Network

the large and small particle thimble filter. After each test, the sampler was disassembled and the filters were removed and p'laced in separate containers. The sampler components that were subject to wall losses (i. e. acceleration jet, collection... parti- j' cn j cle collection efficiency. These dimensional characteristics and the shape of interior components (e. g. collection nozzle leading edge, acceleration jet shape) do become important, however, to the quantity of wall losses. Some...

Bertch, Russell William

2012-06-07

297

On-orbit transport of molecular and particulate contaminants  

NASA Astrophysics Data System (ADS)

In an orbital environment, outgassed, offgassed, ambient, and vented molecular species can cause spacecraft performance degradation by direct impingement or by scattering with each other in the gas phase before and after reemitting from the spacecraft surfaces. This can cause detrimental conditions for the spacecraft surfaces and sensors who view through this cloud. Likewise particulates released by the spacecraft, or nearby systems, can deposit on surfaces, intercept optical lines-of-sight or recontact the vehicle later on in the mission, causing surface damage. This paper presents two models that have improved capability over previous similar models. The integrated spacecraft environments model (ISEM) can be used to predict the transport of spacecraft generated molecular species as they collisionally interact with each other and the ambient molecular environment. An ISEM analysis produces a three dimensional mapping of molecular density and velocity by molecular species, within a modeling volume defined by the user. This model is the next generation of the SPACE and Molflux contamination models and was developed through NASA funding. The orbital particulate trajectory model (OPT) can be used to predict the particulate locations of released particulates as a function of time relative to the spacecraft coordinate system as well as an Earth coordinate system. In this paper the capabilities, applications, validation, and availability of the (ISEM) and the (OPT) model are discussed.

Rantanen, Raymond; Gordon, Tim

1996-11-01

298

Mechanisms of accelerated degradation in the front cells of PEMFC stacks and some mitigation strategies  

NASA Astrophysics Data System (ADS)

The accelerated degradation in the front cells of a polymer electrolyte membrane fuel cell(PEMFC) stack seriously reduces the reliability and durability of the whole stack. Most researches only focus on the size and configuration of the gas intake manifold, which may lead to the maldistribution of flow and pressure. In order to find out the mechanisms of the accelerated degradation in the front cells, an extensive program of experimental and simulation work is initiated and the results are reported. It is found that after long-term lifetime tests the accelerated degradation in the front cells occurs in all three fuel cell stacks with different flow-fields under the U-type feed configuration. Compared with the rear cells of the stack, the voltage of the front cells is much lower at the same current densities and the membrane electrode assembly(MEA) has smaller active area, more catalyst particle agglomeration and higher ohmic impedance. For further investigation, a series of three dimensional isothermal numerical models are built to investigate the degradation mechanisms based on the experimental data. The simulation results reveal that the dry working condition of the membrane and the effect of high-speed gas scouring the MEA are the main causes of the accelerated degradation in the front cells of a PEM fuel cell stack under the U-type feed configuration. Several mitigation strategies that would mitigate these phenomena are presented: removing cells that have failed and replacing them with those of the same aging condition as the average of the stack; choosing a Z-type feed pattern instead of a U-type one; putting several air flow-field plates without MEA in the front of the stack; or exchanging the gas inlet and outlet alternately at a certain interval. This paper specifies the causes of the accelerated degradation in the front cells and provides the mitigation strategies.

Li, Pengcheng; Pei, Pucheng; He, Yongling; Yuan, Xing; Chao, Pengxiang; Wang, Xizhong

2013-11-01

299

40 CFR 52.345 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.345 Section...PLANS Colorado § 52.345 Stack height regulations. The State of Colorado has committed to revise its stack height regulations should EPA complete...

2010-07-01

300

40 CFR 52.2347 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.2347 Section...CONTINUED) Utah § 52.2347 Stack height regulations. The State of Utah has committed to revise its stack height regulations should EPA complete...

2010-07-01

301

40 CFR 52.345 - Stack height regulations.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height regulations. 52.345 Section...PLANS Colorado § 52.345 Stack height regulations. The State of Colorado has committed to revise its stack height regulations should EPA complete...

2014-07-01

302

40 CFR 52.2347 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height regulations. 52.2347 Section...CONTINUED) Utah § 52.2347 Stack height regulations. The State of Utah has committed to revise its stack height regulations should EPA complete...

2013-07-01

303

40 CFR 52.345 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height regulations. 52.345 Section...PLANS Colorado § 52.345 Stack height regulations. The State of Colorado has committed to revise its stack height regulations should EPA complete...

2011-07-01

304

40 CFR 52.2347 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height regulations. 52.2347 Section...CONTINUED) Utah § 52.2347 Stack height regulations. The State of Utah has committed to revise its stack height regulations should EPA complete...

2011-07-01

305

40 CFR 52.345 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height regulations. 52.345 Section...PLANS Colorado § 52.345 Stack height regulations. The State of Colorado has committed to revise its stack height regulations should EPA complete...

2012-07-01

306

40 CFR 52.2347 - Stack height regulations.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height regulations. 52.2347 Section...CONTINUED) Utah § 52.2347 Stack height regulations. The State of Utah has committed to revise its stack height regulations should EPA complete...

2014-07-01

307

40 CFR 52.345 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height regulations. 52.345 Section...PLANS Colorado § 52.345 Stack height regulations. The State of Colorado has committed to revise its stack height regulations should EPA complete...

2013-07-01

308

40 CFR 52.2347 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height regulations. 52.2347 Section...CONTINUED) Utah § 52.2347 Stack height regulations. The State of Utah has committed to revise its stack height regulations should EPA complete...

2012-07-01

309

ANGULAR FLOW INSENSITIVE PITOT TUBE SUITABLE FOR USE WITH STANDARD STACK TESTING EQUIPMENT  

EPA Science Inventory

Five pitot tube designs were tested under various gas flow conditions for accuracy in measuring static and total pressure. The static- and impact-pressure measuring tubes least affected by angular flow were combined and then evaluated in the presence of standard particulate sampl...

310

Teleseismic migration with dual bootstrap stack  

NASA Astrophysics Data System (ADS)

A recently developed stacking scheme called dual bootstrap stack (DBS) is applied to teleseismic migration, using deep earthquakes in South America as sources and USArray as receivers. Built with statistical tests for signal significance and coherence, DBS can achieve a clean separation of signal and noise, and unlike conventional non-linear stacks such as Nth-root stack (NRS) and phase-weighted stack (PWS), it can recover signals even when the signal-to-noise ratio is lower than unity. Migration results with DBS are compared with those with linear stack, NRS and PWS, and DBS-based migration is shown to be able to detect weak, small-scale scatterers that cannot be imaged by NRS and PWS and cannot be confidently identified by linear stack. Based on migration results reproducible among multiple data sets, a number of small-scale scatterers are suggested to exist in the top 400 km and the bottom 1500 km of the mantle in the study region. Though being time-consuming, teleseismic migration with DBS is suggested to be a promising tool to map out a variety of hitherto undetected small-scale heterogeneities in the mantle.

Korenaga, Jun

2014-03-01

311

Barrier RF stacking at Fermilab  

SciTech Connect

A key issue to upgrade the luminosity of the Tevatron Run2 program and to meet the neutrino requirement of the NuMI experiment at Fermilab is to increase the proton intensity on the target. This paper introduces a new scheme to double the number of protons from the Main Injector (MI) to the pbar production target (Run2) and to the pion production target (NuMI). It is based on the fact that the MI momentum acceptance is about a factor of four larger than the momentum spread of the Booster beam. Two RF barriers--one fixed, another moving--are employed to confine the proton beam. The Booster beams are injected off-momentum into the MI and are continuously reflected and compressed by the two barriers. Calculations and simulations show that this scheme could work provided that the Booster beam momentum spread can be kept under control. Compared with slip stacking, a main advantage of this new method is small beam loading effect thanks to the low peak beam current. The RF barriers can be generated by an inductive device, which uses nanocrystal magnet alloy (Finemet) cores and fast high voltage MOSFET switches. This device has been designed and fabricated by a Fermilab-KEK-Caltech team. The first bench test was successful. Beam experiments are being planned.

Weiren Chou et al.

2003-06-04

312

Gaseous and particulate emissions from thermal power plants operating on different technologies.  

PubMed

This paper presents the assessment of gaseous and particulate emissions from thermal power plants operating on different combustion technologies. Four thermal power plants operating on heavy furnace oil were selected for the study, among which three were based on diesel engine technology, while the fourth plant was based on oil-fired steam turbine technology. The stack emissions were monitored for critical air pollutants carbon monoxide, carbon dioxide, oxides of nitrogen, sulfur dioxide, particulate matter, lead, and mercury. The pollutant emissions were measured at optimum load conditions for a period of 6 months with an interval of 1 month. The results of stack emissions were compared with National Environmental Quality Standards of Pakistan and World Bank guidelines for thermal power plants, and few parameters were found higher than the permissible limits of emissions. It was observed that the emissions carbon monoxide, oxides of nitrogen, and particulate matters from diesel engine-based power plants were comparatively higher than the turbine-based power plants. The emissions of sulfur dioxide were high in all the plants, even the plants with different technologies, which was mainly due to high sulfur contents in fuel. PMID:19533397

Athar, Makshoof; Ali, Mahboob; Khan, Misbahul Ain

2010-07-01

313

Evaluation of distributed gas cooling of pressurized PAFC for utility power generation  

NASA Technical Reports Server (NTRS)

A proof-of-concept test for a gas-cooled pressurized phosphoric acid fuel cell is described. After initial feasibility studies in short stacks, two 10 kW stacks are tested. Progress includes: (1) completion of design of the test stations with a recirculating gas cooling loop; (2) atmospheric testing of the baseline stack.

Farooque, M.; Hooper, M.; Maru, H.

1981-01-01

314

Dynamical stability of slip-stacking particles  

NASA Astrophysics Data System (ADS)

We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

Eldred, Jeffrey; Zwaska, Robert

2014-09-01

315

Polarization signatures of airborne particulates  

NASA Astrophysics Data System (ADS)

Exploratory research has been conducted with the aim of completely determining the polarization signatures of selected particulates as a function of wavelength. This may lead to a better understanding of the interaction between electromagnetic radiation and such materials, perhaps leading to the point detection of bio-aerosols present in the atmosphere. To this end, a polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection (with good spectral resolution from 300 to 1100 nm) has been developed. The polarization properties of Bacillus subtilis (surrogate for anthrax spore) are compared to ambient particulate matter species such as pollen, dust, and soot. Differentiating features in the polarization signatures of these samples have been identified, thus demonstrating the potential applicability of this technique for the detection of bio-aerosol in the ambient atmosphere.

Raman, Prashant; Fuller, Kirk A.; Gregory, Don A.

2013-07-01

316

Stacked vapor fed amtec modules  

DOEpatents

The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means. The transition piece divides the member into a first cell and a second cell such that each first and second cell has a beta"-alumina solid electrolyte, a first and second porous electrode and a grid. The transition piece conducts electrons from the interior of the tubular member. There is supply means for supplying sodium to the transporting means. Preferably the supply means is a shell which surrounds the tubular member and is operated at a temperature such that the vaporized sodium condenses thereon. Returning means for returning the condensed sodium from the shell to the transporting means provides a continuous supply of liquid sodium to the transporting means. Also, there are first conducting means for conducting electric current from the transition piece which extends through the shell, and second conducting means for conducting electric current to the grid of the first cell which extends through the shell.

Sievers, Robert K. (North Huntingdon, PA)

1989-01-01

317

Wearable solar cells by stacking textile electrodes.  

PubMed

A new and general method to produce flexible, wearable dye-sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal-textile electrode that was made from micrometer-sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire-shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light. PMID:24789065

Pan, Shaowu; Yang, Zhibin; Chen, Peining; Deng, Jue; Li, Houpu; Peng, Huisheng

2014-06-10

318

Characterization of Piezoelectric Stacks for Space Applications  

NASA Technical Reports Server (NTRS)

Future NASA missions are increasingly seeking to actuate mechanisms to precision levels in the nanometer range and below. Co-fired multilayer piezoelectric stacks offer the required actuation precision that is needed for such mechanisms. To obtain performance statistics and determine reliability for extended use, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and high temperatures and voltages. In order to study the lifetime performance of these stacks, five actuators were driven sinusoidally for up to ten billion cycles. An automated data acquisition system was developed and implemented to monitor each stack's electrical current and voltage waveforms over the life of the test. As part of the monitoring tests, the displacement, impedance, capacitance and leakage current were measured to assess the operation degradation. This paper presents some of the results of this effort.

Sherrit, Stewart; Jones, Christopher; Aldrich, Jack; Blodget, Chad; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

2008-01-01

319

40 CFR 61.53 - Stack sampling.  

Code of Federal Regulations, 2011 CFR

...POLLUTANTS National Emission Standard for Mercury § 61.53 Stack sampling. (a) Mercury ore processing facility. (1) Unless...61.13, each owner or operator processing mercury ore shall test emissions from the source...

2011-07-01

320

40 CFR 61.53 - Stack sampling.  

Code of Federal Regulations, 2014 CFR

...POLLUTANTS National Emission Standard for Mercury § 61.53 Stack sampling. (a) Mercury ore processing facility. (1) Unless...61.13, each owner or operator processing mercury ore shall test emissions from the source...

2014-07-01

321

40 CFR 61.53 - Stack sampling.  

Code of Federal Regulations, 2012 CFR

...POLLUTANTS National Emission Standard for Mercury § 61.53 Stack sampling. (a) Mercury ore processing facility. (1) Unless...61.13, each owner or operator processing mercury ore shall test emissions from the source...

2012-07-01

322

40 CFR 61.53 - Stack sampling.  

Code of Federal Regulations, 2013 CFR

...POLLUTANTS National Emission Standard for Mercury § 61.53 Stack sampling. (a) Mercury ore processing facility. (1) Unless...61.13, each owner or operator processing mercury ore shall test emissions from the source...

2013-07-01

323

StackOverview 2.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3  

E-print Network

17 Web #12;Web Web 81% Web Web Web Web StackOverview #12;1 1 2 Web 3 2.2.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Web . . . . . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Web 6 3.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3

Tanaka, Jiro

324

40 CFR 61.44 - Stack sampling.  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor Firing § 61.44 Stack sampling. ...61.42(b). (b) All samples shall be analyzed, and beryllium emissions shall be determined within 30 days after...

2012-07-01

325

40 CFR 61.33 - Stack sampling.  

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.33 Stack sampling. (a) Unless a waiver...Administrator. (d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the...

2014-07-01

326

40 CFR 61.44 - Stack sampling.  

Code of Federal Regulations, 2013 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor Firing § 61.44 Stack sampling. ...61.42(b). (b) All samples shall be analyzed, and beryllium emissions shall be determined within 30 days after...

2013-07-01

327

40 CFR 61.33 - Stack sampling.  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.33 Stack sampling. (a) Unless a waiver...Administrator. (d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the...

2012-07-01

328

40 CFR 61.33 - Stack sampling.  

Code of Federal Regulations, 2010 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.33 Stack sampling. (a) Unless a waiver...Administrator. (d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the...

2010-07-01

329

40 CFR 61.33 - Stack sampling.  

Code of Federal Regulations, 2013 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.33 Stack sampling. (a) Unless a waiver...Administrator. (d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the...

2013-07-01

330

40 CFR 61.44 - Stack sampling.  

Code of Federal Regulations, 2014 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor Firing § 61.44 Stack sampling. ...61.42(b). (b) All samples shall be analyzed, and beryllium emissions shall be determined within 30 days after...

2014-07-01

331

40 CFR 61.33 - Stack sampling.  

Code of Federal Regulations, 2011 CFR

...FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.33 Stack sampling. (a) Unless a waiver...Administrator. (d) All samples shall be analyzed and beryllium emissions shall be determined within 30 days after the...

2011-07-01

332

Impact of HK \\/ MG stacks and future device scaling on RTN  

Microsoft Academic Search

This work demonstrates the close relationship between device scaling and the threshold voltage variation (?Vth) of random telegraph noise (RTN) in high-? and metal gate (HK \\/ MG) stacks. Statistical analysis clarifies that high temperature forming gas annealing can suppress the RTN ?Vth. And properly annealed HK FETs have smaller RTN ?Vth than SiON FETs, due mostly to fewer traps

Naoki Tega; Hiroshi Miki; Zhibin Ren; Christoper P. D'Emic; Yu Zhu; David J. Frank; Michael A. Guillorn; Dae-Gyu Park; Wilfried Haensch; Kazuyoshi Torii

2011-01-01

333

THE EFFECTS OF A SQUAT BUILDING ON SHORT STACK EFFLUENTS: A WIND TUNNEL STUDY  

EPA Science Inventory

In a wind tunnel study, the influence of the highly turbulent region found in the lee of a model building upon plumes emitted from short stacks was examined through smoke visualization and tracer gas concentration mappings. The study was conducted in the Meteorological Wind Tunne...

334

Consideration of numerical simulation parameters and heat transfer models for a molten carbonate fuel cell stack  

Microsoft Academic Search

A fuel cell stack model based on differential heat balance equations was solved numerically with a computational fluid dynamics code. Theoretical aspects in the simulation of a molten carbonate fuel cell (MCFC) performance model were discussed with regard to numerical accuracy of temperature prediction. The effect of grid setting for gas channel depth was studied to ensure how coarse it

Joon-Ho Koh; Hai-Kung Seo; Young-Sung Yoo; Hee Chun Lim

2002-01-01

335

P0906-090-Chnani Macroscopic Model of Solid Oxide Fuel Cell Stack for  

E-print Network

1 P0906-090-Chnani Macroscopic Model of Solid Oxide Fuel Cell Stack for Integrating in a Generator fuel cell (SOFC) with the aim to perform a simulation of the whole generator. Three sub-models have at the catalytic sites and gas flows at fuel cell input and output. The electrical response is based

Paris-Sud XI, Université de

336

Solid state marx modulator with blumlein stack for bipolar pulse generation  

Microsoft Academic Search

Sub-nanosecond bipolar high voltage pulses are a very important tool for food processing, medical treatment, waste water and exhaust gas processing. A Hybrid Modulator for sub-microsecond bipolar pulse generation, comprising an unipolar solidstate Marx generator connected to a load through a stack Blumlein system that produces bipolar pulses and further multiplies the pulse voltage amplitude, is presented. Experimental results from

J. P. M. Mendes; H. Canacsinh; L. M. Redondo; José O. Rossi

2011-01-01

337

Dry stacking of wastewater treatment sludges.  

PubMed

Drying pans are used during wastewater treatment (WWT) to store, stabilise and dry residual solids. The pans are filled with sludge that dries via exposure to sunshine and wind. We propose that drying pans be operated based on dry stacking principles, a technique with proven success in the mineral processing industry. The implementation of the dry stacking technique requires very little in the way of additional engineering beyond a conventional drying pan. By applying the sludge in thin layers, the sludge naturally forms its own stack with an angle that is dependent on the consistency of the material. The benefits of dry stacking are that the slope allows instantaneous run-off of rainfall and supernatant, allowing operation throughout the year rather than seasonally. The layering approach also maximises the evaporation achieved in the available deposition area compared to filling the pans sequentially. A series of laboratory tests were carried out on samples from Melbourne Water's Western Treatment Plant in Werribee, Australia, to provide validation of the dry stacking concept for WWT sludges. Rheological tests showed that samples had appropriate flow properties to form stacks. Drying and re-wetting tests on the samples indicated that a sloped, partially dry sludge sheds rainfall, depending on the slope, cake dryness and amount of rainfall. Local rainfall data was used to estimate a potential increase in pan throughput of 65%-140% due to dry stacking. The greatest improvements were predicted to occur during wetter years. In combination, the results indicated that dry stacking has the potential to dramatically improve the performance of WWT sludge drying pans. PMID:23642401

Stickland, Anthony D; Rees, Catherine A; Mosse, Kim P M; Dixon, David R; Scales, Peter J

2013-06-15

338

Derived categories and stacks in physics  

E-print Network

In this note we review how both derived categories and stacks enter physics. The physical realization of each has many formal similarities. For example, in both cases, equivalences are realized via renormalization group flow: in the case of derived categories, (boundary) renormalization group flow realizes the mathematical procedure of localization on quasi-isomorphisms, and in the case of stacks, worldsheet renormalization group flow realizes presentation-independence. For both, we outline current technical issues and applications.

E. Sharpe

2006-09-13

339

Stacking interactions in PUF?RNA complexes  

SciTech Connect

Stacking interactions between amino acids and bases are common in RNA-protein interactions. Many proteins that regulate mRNAs interact with single-stranded RNA elements in the 3' UTR (3'-untranslated region) of their targets. PUF proteins are exemplary. Here we focus on complexes formed between a Caenorhabditis elegans PUF protein, FBF, and its cognate RNAs. Stacking interactions are particularly prominent and involve every RNA base in the recognition element. To assess the contribution of stacking interactions to formation of the RNA-protein complex, we combine in vivo selection experiments with site-directed mutagenesis, biochemistry, and structural analysis. Our results reveal that the identities of stacking amino acids in FBF affect both the affinity and specificity of the RNA-protein interaction. Substitutions in amino acid side chains can restrict or broaden RNA specificity. We conclude that the identities of stacking residues are important in achieving the natural specificities of PUF proteins. Similarly, in PUF proteins engineered to bind new RNA sequences, the identity of stacking residues may contribute to 'target' versus 'off-target' interactions, and thus be an important consideration in the design of proteins with new specificities.

Yiling Koh, Yvonne; Wang, Yeming; Qiu, Chen; Opperman, Laura; Gross, Leah; Tanaka Hall, Traci M.; Wickens, Marvin (NIH); (UW)

2012-07-02

340

DEVELOPMENT OF COMPUTER MODULES OF PARTICULATE PROCESSES FOR REGIONAL PARTICULATE MODEL  

EPA Science Inventory

The development of an aerosol model for inclusion in the EPA Regional Particulate Model is described. Existing computer modules of particulate processes developed under EPA contract by Professors Brock, Seinfeld, and Whitby are compared to determine efficient and accurate methods...

341

Diesel particulate filter with zoned resistive heater  

SciTech Connect

A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

Gonze, Eugene V [Pinckney, MI

2011-03-08

342

Charge transport through a molecular ?-stack: double helical DNA  

Microsoft Academic Search

Double helical DNA, containing a ?-stacked array of base pairs within its interior, can be considered as a molecular analogue of solid state ?-stacked arrays. Like the solid state materials, the DNA base pair stack provides a medium to facilitate charge transport. However, owing to the dynamical motions of the base pairs within the molecular stack, as well as sequence-dependent

Christopher R. Treadway; Michael G. Hill; Jacqueline K. Barton

2002-01-01

343

INSTANTONS AND FRAMED SHEAVES ON KAHLER DELIGNE-MUMFORD STACKS  

E-print Network

analytic stacks 3 3. Differential geometry on smooth Deligne-Mumford analytic and differentiable stacks 7 4. Hermite-Einstein metrics on compact K¨ahler Deligne-Mumford analytic stacks 11 5. Hermite-Einstein metrics on some noncompact K¨ahler Deligne-Mumford analytic stacks 12 6. An application: orbifold

Paris-Sud XI, Université de

344

Mercury Control With The Advanced Hybrid Particulate Collector  

SciTech Connect

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory Program Solicitation DE-FC26-01NT41184 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the original five-task project was to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach included benchscale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control. The scope of work was modified to include an additional sixth task, initiated in April 2003. The objective of this task was to evaluate the mercury capture effectiveness of the AHPC when used with elemental mercury oxidation additives. This project, which is now in the final report phase, demonstrated at the pilot-scale level a technology that provides a cost-effective technique to control mercury and, at the same time, greatly enhances fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution for improved fine particulate control combined with effective mercury control for a large segment of the U.S. utility industry as well as other industries.

Stanley J. Miller; Ye Zhuang; Jay C. Almlie

2004-12-31

345

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

346

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

347

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

348

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

349

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

350

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

351

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

352

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

353

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

354

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

355

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

356

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

357

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

358

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

359

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

360

Powder and particulate production of metallic alloys  

NASA Technical Reports Server (NTRS)

Developments of particulate metallurgy of alloyed materials where the final products is a fully dense body are discussed. Particulates are defined as powders, flakes, foils, silvers, ribbons and strip. Because rapid solidification is an important factor in particulate metallurgy, all of the particulates must have at least one dimension which is very fine, sometimes as fine as 10 to 50 microns, but move typically up to several hundred microns, provided that the dimension permits a minimum solidification rate of at least 100 K/s.

Grant, N. J.

1982-01-01

361

Electrically heated particulate filter using catalyst striping  

DOEpatents

An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating is applied to the PF that increases a temperature of the combustion of the particulates within the PF.

Gonze, Eugene V; Paratore, Jr., Michael J; Ament, Frank

2013-07-16

362

Electrically heated particulate filter embedded heater design  

DOEpatents

An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine and wherein an upstream surface of the particulate filter includes machined grooves. A grid of electrically resistive material is inserted into the machined grooves of the exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.

Gonze, Eugene V.; Chapman, Mark R.

2014-07-01

363

Methods of separating particulate residue streams  

DOEpatents

A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

Hoskinson, Reed L. (Rigby, ID); Kenney, Kevin L. (Idaho Falls, ID); Wright, Christopher T. (Idaho Falls, ID); Hess, J. Richard (Idaho Falls, ID)

2011-04-05

364

Particulate Matter (Environmental Health Student Portal)  

MedlinePLUS

... Gases Impact on Weather Health Effects Take Action Water Pollution Water Pollution Home Chemicals and Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Particulate ...

365

Stacking in colloidal nanoplatelets: tuning excitonic properties.  

PubMed

Colloidal semiconductor quantum wells, also commonly known as nanoplatelets (NPLs), have arisen among the most promising materials for light generation and harvesting applications. Recently, NPLs have been found to assemble in stacks. However, their emerging characteristics essential to these applications have not been previously controlled or understood. In this report, we systematically investigate and present excitonic properties of controlled column-like NPL assemblies. Here, by a controlled gradual process, we show that stacking in colloidal quantum wells substantially increases exciton transfer and trapping. As NPLs form into stacks, surprisingly we find an order of magnitude decrease in their photoluminescence quantum yield, while the transient fluorescence decay is considerably accelerated. These observations are corroborated by ultraefficient Förster resonance energy transfer (FRET) in the stacked NPLs, in which exciton migration is estimated to be in the ultralong range (>100 nm). Homo-FRET (i.e., FRET among the same emitters) is found to be ultraefficient, reaching levels as high as 99.9% at room temperature owing to the close-packed collinear orientation of the NPLs along with their large extinction coefficient and small Stokes shift, resulting in a large Förster radius of ?13.5 nm. Consequently, the strong and long-range homo-FRET boosts exciton trapping in nonemissive NPLs, acting as exciton sink centers, quenching photoluminescence from the stacked NPLs due to rapid nonradiative recombination of the trapped excitons. The rate-equation-based model, which considers the exciton transfer and the radiative and nonradiative recombination within the stacks, shows an excellent match with the experimental data. These results show the critical significance of stacking control in NPL solids, which exhibit completely different signatures of homo-FRET as compared to that in colloidal nanocrystals due to the absence of inhomogeneous broadening. PMID:25469555

Guzelturk, Burak; Erdem, Onur; Olutas, Murat; Kelestemur, Yusuf; Demir, Hilmi Volkan

2014-12-23

366

HELSINKI UNIVERSITY OF TECHNOLOGY ENE-47.153 PARTICULATES #2PARTICULATES #2  

E-print Network

particulate control ·· Particulate emission control for vehiclesParticulate emission control for vehicles see OF TECHNOLOGY ENE-47.153 Filters : major types & characteristicsFilters : major types & characteristics Bag.153 Filters : cleaning methodsFilters : cleaning methods TypeType MethodMethod MechanismMechanism Bag filter

Zevenhoven, Ron

367

Assessment of the 3410 Building Filtered Exhaust Stack Sampling Probe Location  

SciTech Connect

Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3410 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.

Glissmeyer, John A.; Flaherty, Julia E.

2010-07-16

368

Assessment of the 3420 Building Filtered Exhaust Stack Sampling Probe Location  

SciTech Connect

Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3420 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.

Glissmeyer, John A.; Flaherty, Julia E.

2010-07-16

369

Measuring Particulate Emissions from Autos  

NSDL National Science Digital Library

This learning activity from the Advanced Technology Environmental and Energy Center (ATEEC) is intended to help environmental science or biology students connect a real-world problem to the application of math, science, technical and critical thinking knowledge and skill concepts; the lesson specifically focuses on particulate emissions from automobiles and their impact on air pollution. The activity should take about one class period to complete (plus time for students to complete analysis outside of class), and requires a few easily obtainable materials. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

Willey, Babe

370

21 CFR 868.6885 - Medical gas yoke assembly.  

Code of Federal Regulations, 2013 CFR

...medical gas yoke assembly is a device intended to connect medical gas cylinders to regulators or needle valves to supply gases for anesthesia or respiratory therapy. The device may include a particulate filter. (b) Classification. Class I (general...

2013-04-01

371

21 CFR 868.6885 - Medical gas yoke assembly.  

Code of Federal Regulations, 2014 CFR

...medical gas yoke assembly is a device intended to connect medical gas cylinders to regulators or needle valves to supply gases for anesthesia or respiratory therapy. The device may include a particulate filter. (b) Classification. Class I (general...

2014-04-01

372

21 CFR 868.6885 - Medical gas yoke assembly.  

Code of Federal Regulations, 2012 CFR

...medical gas yoke assembly is a device intended to connect medical gas cylinders to regulators or needle valves to supply gases for anesthesia or respiratory therapy. The device may include a particulate filter. (b) Classification. Class I (general...

2012-04-01

373

21 CFR 868.6885 - Medical gas yoke assembly.  

Code of Federal Regulations, 2011 CFR

...medical gas yoke assembly is a device intended to connect medical gas cylinders to regulators or needle valves to supply gases for anesthesia or respiratory therapy. The device may include a particulate filter. (b) Classification. Class I (general...

2011-04-01

374

Inflatable containment diaphragm for sealing and removing stacks  

DOEpatents

A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.

Meskanick, G.R.; Rosso, D.T.

1993-04-13

375

Inflatable containment diaphragm for sealing and removing stacks  

DOEpatents

A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.

Meskanick, Gerald R. (Elizabeth, PA); Rosso, David T. (Pittsburgh, PA)

1993-01-01

376

Control of NOx and particulate emissions from spreader-stokers fired with hogged wood  

SciTech Connect

The formation and emission of nitrogen oxides and particulate carry-over were studied from spreader-stoker combustion of nogged Douglas-fir, with a focus on optimizing the combustion conditions in each of the two distinct combustion zones, the bed phase and the suspension phase. Local oxygen availability was the controlling parameter for nitric oxide formation. Minimum nitric oxide emissions were found when local air: fuel stoichiometric ratios were held at 0.70-0.85, with emissions reduced as much as 39%. Long first-stage residence times allowed intermediate nitrogenous species to decay to molecular nitrogen, if there was sufficient oxygen for first-stage formation of nitric oxide. Entrainment of large particulates was a function of furnace gas velocities in the bed zone. Operation of the furnace at low stoichiometric ratios (fuel rich) in the bed zone reduced these gas velocities and thus reduced particulate emissions. (Refs. 12).

Munro, J.M.; Bradshaw, F.W.; Pershing, D.W.

1987-06-01

377

Fungal Melanins Differ in Planar Stacking Distances  

PubMed Central

Melanins are notoriously difficult to study because they are amorphous, insoluble and often associated with other biological materials. Consequently, there is a dearth of structural techniques to study this enigmatic pigment. Current models of melanin structure envision the stacking of planar structures. X ray diffraction has historically been used to deduce stacking parameters. In this study we used X ray diffraction to analyze melanins derived from Cryptococcus neoformans, Aspergillus niger, Wangiella dermatitides and Coprinus comatus. Analysis of melanin in melanized C. neoformans encapsulated cells was precluded by the fortuitous finding that the capsular polysaccharide had a diffraction spectrum that was similar to that of isolated melanin. The capsular polysaccharide spectrum was dominated by a broad non-Bragg feature consistent with origin from a repeating structural motif that may arise from inter-molecular interactions and/or possibly gel organization. Hence, we isolated melanin from each fungal species and compared diffraction parameters. The results show that the inferred stacking distances of fungal melanins differ from that reported for synthetic melanin and neuromelanin, occupying intermediate position between these other melanins. These results suggest that all melanins have a fundamental diffracting unit composed of planar graphitic assemblies that can differ in stacking distance. The stacking peak appears to be a distinguishing universal feature of melanins that may be of use in characterizing these enigmatic pigments. PMID:22359541

Casadevall, Arturo; Nakouzi, Antonio; Crippa, Pier R.; Eisner, Melvin

2012-01-01

378

TESTING FOR CPT VIOLATION IN Bstack">0stack">s SEMILEPTONIC DECAYS  

NASA Astrophysics Data System (ADS)

A DØ analysis measuring the charge asymmetry Astack">bstack">sl of like-sign dimuon events due to semileptonic b-hadron decays at the Fermilab Tevatron Collider has shown indications of possible anomalous CP violation in the mixing of neutral B mesons. This result has been used to extract the first senstivity to CPT violation in the Bstack">0stack">s system. An analysis to explore further this anomaly by specifically measuring the semileptonic charge asymmetry, astack">sstack">sl, in Bstack">0stack">s decays is described, as well as how a variant of this analysis can be used to explore a larger set of CPT-violating parameters in the Bstack">0stack">s system for the first time.

Kooten, R. Van

2014-01-01

379

40 CFR 52.1880 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Control strategy: Particulate matter. 52.1880 Section 52.1880 Protection...1880 Control strategy: Particulate matter. (a) The requirements of subpart...the secondary standards for particulate matter in the Greater Metropolitan...

2012-07-01

380

40 CFR 52.776 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Control strategy: Particulate matter. 52.776 Section 52.776 Protection...776 Control strategy: Particulate matter. (a) The requirements of subpart...the secondary standards for particulate matter in the Metropolitan Indianapolis...

2012-07-01

381

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2010-07-01

382

40 CFR 52.776 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Control strategy: Particulate matter. 52.776 Section 52.776 Protection...776 Control strategy: Particulate matter. (a) The requirements of subpart...the secondary standards for particulate matter in the Metropolitan Indianapolis...

2011-07-01

383

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2011-07-01

384

40 CFR 52.2584 - Control strategy; Particulate matter.  

Code of Federal Regulations, 2014 CFR

...false Control strategy; Particulate matter. 52.2584 Section 52.2584 Protection...2584 Control strategy; Particulate matter. (a) Part D—Disapproval...maintain the standards for particulate matter, because it does not contain an...

2014-07-01

385

40 CFR 52.776 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2013 CFR

...false Control strategy: Particulate matter. 52.776 Section 52.776 Protection...776 Control strategy: Particulate matter. Link to an amendment published at...the secondary standards for particulate matter in the Metropolitan Indianapolis...

2013-07-01

386

40 CFR 52.776 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2010 CFR

...false Control strategy: Particulate matter. 52.776 Section 52.776 Protection...776 Control strategy: Particulate matter. (a) The requirements of subpart...the secondary standards for particulate matter in the Metropolitan Indianapolis...

2010-07-01

387

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2013-07-01

388

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2012-07-01

389

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2010 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2010-07-01

390

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2014-07-01

391

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2013 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2013-07-01

392

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Standards to control particulate matter. 266.105 Section 266.105 Protection...105 Standards to control particulate matter. (a) A boiler or industrial furnace...hazardous waste may not emit particulate matter in excess of 180 milligrams per...

2012-07-01

393

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2011-07-01

394

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2012-07-01

395

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Standards to control particulate matter. 266.105 Section 266.105 Protection...105 Standards to control particulate matter. (a) A boiler or industrial furnace...hazardous waste may not emit particulate matter in excess of 180 milligrams per...

2011-07-01

396

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2014 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2014-07-01

397

30 CFR 57.5075 - Diesel particulate records.  

Code of Federal Regulations, 2010 CFR

... 1 2010-07-01 2010-07-01 false Diesel particulate records. 57.5075 Section 57...Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only §...

2010-07-01

398

Airborne particulate matter in spacecraft  

NASA Technical Reports Server (NTRS)

Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

1988-01-01

399

High efficiency particulate air filter  

SciTech Connect

A high efficiency particulate air filter is described which is characterized by being lightweight and readily disposable after use, and comprising a sheet of high efficiency particulate air filtering medium folded upon itself in accordion fashion to form a generally rectangular filter pack which includes opposite side edges defined by the edges of the folded sheet and opposite end edges defined by the ends of the sheet, a relatively thin and lightweight four sided peripheral frame surrounding and supporting the filter pack, with the four sides of the frame being separately molded and overlying and covering respective ones of the opposite side edges and opposite end edges of the pack, the frame being composed of a relatively thin, hard, air impermeable material which is self-bonded and sealed to the filter medium over substantially the entire interface between the medium and the frame to effectively preclude the leakage of air therebetween, and with adjacent edges of adjacent sides of the frame being self-bonded to each other, the frame further having an exterior surface which includes a peripheral shoulder formed in the exterior surface adjacent at least one end of the filter to define a peripheral ledge thereabout, and at least one separate header surrounding and sealably secured to the external periphery of the frame, with the one header being mounted upon the ledge in abutting relation with the associated shoulder.

Allan, T.T.; Cramer, R.V.

1987-08-11

400

Southern Fine Particulate Monitoring Project  

SciTech Connect

This final project report presents experimental details, results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the October, 2001-September, 2002 study period.The host site for these measurement activities is the North Birmingham PM monitoring station by the Jefferson County Health Department in Birmingham, AL.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. During the course of the project, measurement intercomparison data were developed for these instruments and several complementary measurements at the site. The report details the instrument set and operating procedures and describes the resulting data. Report subsections present an overview summary of the data, followed by detailed description of the systematic time behavior of PM{sub 2.5} and other specific particulate size fractions. Specific subsections are included for particle size distribution, light scattering, and particle sulfate data. The final subsection addresses application of the measurements to the practical questions of fine PM generation and transport, source attribution, and PM{sub 2.5} management strategies.

Ashley Williamson

2003-05-31

401

Production of Dissolved and Particulate Hydrogen Sulfide by Marine Phytoplankton  

NASA Astrophysics Data System (ADS)

Hydrogen sulfide is a reactive gas that in its dissolved form can be found as dissociated ions and meta-sulfide complexes, or in the particulate state as insoluble metal-sulfides. In oxygenated surface seawater the source of this hydrogen sulfide is the hydrolysis of dissolved carbonyl sulfide, but also emissions from marine phytoplankton. In this way, the phytoplankton production of hydrogen sulfide can affect the cycling of dissolved trace metals such as zinc, copper, and mercury. To examine phytoplankton production of hydrogen sulfide, four different phytoplankton species were grown in batch cultures and the concentrations of dissolved (<0.4 um) and particulate sulfide (>0.4 um) monitored over time. The chlorophyte Dunaliella produced the most hydrogen sulfide (diss>part), followed by the diatom Skeletonema (part>diss), the chryptophyte Rhodomonas (diss>part), and finally the prymnesiophyte E. huxleyi. (part>diss). Thus, all of the phytoplankton cultured emitted hydrogen sulfide, and the fact that particulate sulfide was present demonstrated that it reacts with metals to form insoluble metal sulfides, thus affecting metal cycling.

Grace, C.; Davis, J. A.; Cutter, G. A.

2002-12-01

402

Cost-effective particulate control options at Potomac Electric Power Company's Dickerson Station: An integrated approach to current and future particulate limits  

SciTech Connect

The Dickerson Generating Station evaluated several particulate control options to identify the most cost-effective option. The study's goals were to: eliminate the particulate scrubber and its high maintenance costs, and incorporate flexibility for low-sulfur coal and possible stricter emission limits. Each of the three Dickerson 190 MW units has a small 37-year-old electrostatic precipitator and a wet particulate scrubber. The study evaluated alternatives to replace the scrubber and enhance ESP performance: Existing ESP alternatives--Extend height of existing ESP; Flue gas conditioning. Scrubber stream alternatives--Partial-flow ESP or pulse jet baghouse. Full-flow alternatives--Supplemental ESP; COHPAC baghouse; replacement ESP or baghouse. A technical and economic prescreening eliminated some of the options. Capital, operating, and life cycle costs were estimated for the remaining options to determine the most cost-effective alternative. This paper will present the technical and economic evaluations done for this study, including performance and costs.

Christoffersen, S.W.; Rouse, G.T.; Krasnopoler, M.J.; Chapowski, J.A.

1998-07-01

403

Mass transfer within electrostatic precipitators: in-flight adsorption of mercury by charged suspended particulates  

SciTech Connect

Electrostatic precipitation is the dominant method of particulate control used for coal combustion, and varying degrees of mercury capture and transformation have been reported across ESPs. Nevertheless, the fate of gas-phase mercury within an ESP remains poorly understood. The present analysis focuses on the gas-particle mass transfer that occurs within a charged aerosol in an ESP. As a necessary step in gas-phase mercury adsorption or transformation, gas-particle mass transfer - particularly in configurations other than fixed beds - has received far less attention than studies of adsorption kinetics. Our previous analysis showed that only a small fraction of gas-phase mercury entering an ESP is likely to be adsorbed by collected particulate matter on the plate electrodes. The present simplified analysis provides insight into gas-particle mass transfer within an ESP under two limiting conditions: laminar and turbulent fluid flows. The analysis reveals that during the process of particulate collection, gas-particle mass transfer can be quite high, easily exceeding the mass transfer to ESP plate electrodes in most cases. Decreasing particle size, increasing particle mass loading, and increasing temperature all result in increased gas-particle mass transfer. The analysis predicts significantly greater gas-particle mass transfer in the laminar limit than in the turbulent limit; however, the differences become negligible under conditions where other factors, such as total mass of suspended particulates, are the controlling mass transfer parameters. Results are compared to selected pilot- and full-scale sorbent injection data. 41 refs., 5 figs.

Herek L. Clack [Illinois Institute of Technology, Chicago, IL (United States). Department of Mechanical, Materials and Aerospace Engineering

2006-06-01

404

Radiation Tolerant Intelligent Memory Stack (RTIMS)  

NASA Technical Reports Server (NTRS)

The Radiation Tolerant Intelligent Memory Stack (RTIMS), suitable for both geostationary and low earth orbit missions, has been developed. The memory module is fully functional and undergoing environmental and radiation characterization. A self-contained flight-like module is expected to be completed in 2006. RTIMS provides reconfigurable circuitry and 2 gigabits of error corrected or 1 gigabit of triple redundant digital memory in a small package. RTIMS utilizes circuit stacking of heterogeneous components and radiation shielding technologies. A reprogrammable field programmable gate array (FPGA), six synchronous dynamic random access memories, linear regulator, and the radiation mitigation circuitries are stacked into a module of 42.7mm x 42.7mm x 13.00mm. Triple module redundancy, current limiting, configuration scrubbing, and single event function interrupt detection are employed to mitigate radiation effects. The mitigation techniques significantly simplify system design. RTIMS is well suited for deployment in real-time data processing, reconfigurable computing, and memory intensive applications.

Ng, Tak-kwong; Herath, Jeffrey A.

2006-01-01

405

Effects of Endwall Geometry and Stacking on Two-Stage Supersonic Turbine Performance  

NASA Technical Reports Server (NTRS)

The drive towards high-work turbines has led to designs which can be compact, transonic, supersonic, counter rotating, or use a dense drive gas. These aggressive designs can lead to strong secondary flows and airfoil flow separation. In many cases the secondary and separated flows can be minimized by contouring the hub/shroud endwalls and/or modifying the airfoil stacking. In this study, three-dimensional unsteady Navier-Stokes simulations were performed to study three different endwall shapes between the first-stage vanes and rotors, as well as two different stackings for the first-stage vanes. The predicted results indicate that changing the stacking of the first-stage vanes can significantly impact endwall separation (and turbine performance) in regions where the endwall profile changes.

Dorney, Daniel J.; Griffin, Lisa W.; Huber, Frank W.; Sondak, Douglas L.; Turner, Jim (Technical Monitor)

2002-01-01

406

Zoned electrical heater arranged in spaced relationship from particulate filter  

DOEpatents

A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

Gonze, Eugene V [Pinckney, MI

2011-11-15

407

Compounds in airborne particulates - Salts and hydrocarbons. [at Cleveland, OH  

NASA Technical Reports Server (NTRS)

Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatics as a group, sulfate, nitrate, fluoride, acidity, and carbon in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1-year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. High concentrations downwind of coke ovens for 3,4 benzopyrene are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.

King, R. B.; Antoine, A. C.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

1977-01-01

408

RISK MANAGEMENT FOR INDOOR PARTICULATE MATTER  

EPA Science Inventory

Because people spend 90% of their time indoors, exposure to particulate matter indoors is a major contributor to the risk associated with particulate matter. The risk due to indoor exposure is probably even higher for susceptible populations such as the elderly, the sick, and t...

409

Air Quality Criteria for Particulate Matter.  

ERIC Educational Resources Information Center

To assist states in developing air quality standards, this book offers a review of literature related to atmospheric particulates and the development of criteria for air quality. It not only summarizes the current scientific knowledge of particulate air pollution, but points up the major deficiencies in that knowledge and the need for further…

National Air Pollution Control Administration (DHEW), Washington, DC.

410

EMISSION CONTROL: CONTROL OF FINE PARTICULATE EMISSIONS  

EPA Science Inventory

This paper reviews the results of fine particulate control technology tests by the Particulate Technology Branch (PATB) of EPA's IERL-RTP over the last 3 years. The review covers characterization of conventional control equipment, assessment of the collectability of dusts, and ne...

411

Ultrasonic detecting and identifying of particulates  

SciTech Connect

A method of detecting and identifying particulates in the recirculating fluid flow for an oil recovery system by counting the number of ultrasonic pulses reflected from the particulates and comparing the number counted with the amount of attenuation of ultrasonic energy across the flow.

Abts, L.R.

1983-05-03

412

Gas sampling system for reactive gas-solid mixtures  

DOEpatents

An apparatus and method for sampling a gas containing a reactive particulate solid phase flowing through a duct and for communicating a representative sample to a gas analyzer. A sample probe sheath 32 with an angular opening 34 extends vertically into a sample gas duct 30. The angular opening 34 is opposite the gas flow. A gas sampling probe 36 concentrically located within sheath 32 along with calibration probe 40 partly extend in the sheath 32. Calibration probe 40 extends further in the sheath 32 than gas sampling probe 36 for purging the probe sheath area with a calibration gas during calibration.

Daum, Edward D. (Alliance, OH); Downs, William (Alliance, OH); Jankura, Bryan J. (Mogadore, OH); McCoury, Jr., John M. (Mineral City, OH)

1989-01-01

413

Gas sampling system for reactive gas-solid mixtures  

DOEpatents

An apparatus and method for sampling gas containing a reactive particulate solid phase flowing through a duct and for communicating a representative sample to a gas analyzer. A sample probe sheath 32 with an angular opening 34 extends vertically into a sample gas duct 30. The angular opening 34 is opposite the gas flow. A gas sampling probe 36 concentrically located within sheath 32 along with calibration probe 40 partly extends in the sheath 32. Calibration probe 40 extends further in the sheath 32 than gas sampling probe 36 for purging the probe sheath area with a calibration gas during calibration.

Daum, Edward D. (Alliance, OH); Downs, William (Alliance, OH); Jankura, Bryan J. (Mogadore, OH); McCoury, Jr., John M. (Mineral City, OH)

1990-01-01

414

Stack Gas Heat Recovery from 100 to 1200 HP Boilers  

E-print Network

With newspaper reports of March 1980 fuel price increases at as much as a 110% annualized rate, energy users are becoming more keenly aware of the urgency of conserving energy--and energy dollars. It is becoming increasingly more difficult...

Judson, T. H.

1980-01-01

415

Long term performance of 137 stack gas continuous emission monitors  

SciTech Connect

Performance data were obtained on 137 monitors representing a total operating time of 1,600,000 hours. The monitors were classified as follows: 74 NO/sub x/, 37 SO/sub 2/, 7 combination NO/sub x//SO/sub 2/, 8 O/sub 2/, and 11 opacity. Results show that data processor failure accounted for 84% of O/sub 2/, 74% of the opacity, and 61% of the combination SO/sub 2//NO/sub x/ continuous emission monitor malfunctions. Each of these three types of moniters had the same average malfunction time (17 hours). Data from one source, a refinery, estimated operation, calibration, and maintenance costs to be $70,000/yr/monitor. (JMT)

Hebert, R.P. (Scott Environmental Tech., Inc., San Bernardino, CA); Mitchell, W.J.

1983-02-01

416

Fuel gas desulfurization  

DOEpatents

A method for removing sulfurous gases such as H.sub.2 S and COS from a fuel gas is disclosed wherein limestone particulates containing iron sulfide provide catalytic absorption of the H.sub.2 S and COS by the limestone. The method is effective at temperatures of 400.degree. C. to 700.degree. C. in particular.

Yang, Ralph T. (Tonawanda, NY); Shen, Ming-Shing (Rocky Point, NY)

1981-01-01

417

Delivery of molecular versus particulate water in spontaneously breathing tracheotomized patients  

Microsoft Academic Search

Background. Adequate humidification of inspired gas with active or passive humidifiers is a standard of care for tracheotomized patients. In this study, a comparison is made between the tracheal climate after tracheobronchial humidifica- tion either with molecular water (via a vaporizing humidifier) or particulate water (via spray) in spontaneously breathing tracheo- tomized patients. Methods. We performed a randomized, 2-way crossover

Ajnacska Rozsasi; Jochen Dürr; Richard Leiacker; Tilman Keck

2007-01-01

418

Method for retorting particulate solids having recoverable volatile constituents in a rotating horizontal chamber  

Microsoft Academic Search

A method and apparatus is disclosed for retorting particulate solid materials, particularly hydrocarbon-containing materials such as oil shale, oil sands, tar sands, coal shale, coal tailings, and the like, for the recovery of a volatile constituent such as oil or gas. A rotary retorting apparatus is employed which consists of a cylindrical drum, or other similar regularly shaped chamber, with

L. M. Reed; W. A. Reed; W. C. Saeman

1984-01-01

419

Effects of exothermic chemical reaction on the photoacoustic effect from particulate suspensions  

Microsoft Academic Search

Irradiation of chemically reactive particulate suspensions by high power, pulsed laser radiation initiates reactions at the sites of the particles so that besides the absorbed optical energy, chemical energy is liberated. In addition to the release of chemical energy, chemical reaction can result in gas production both of which result in enhancement in the amplitude of the photoacoustic effect. Here

Han Jung Park; Binbin Wu; Gerald J. Diebold

2011-01-01

420

Lightweight bipolar metal-gas battery  

Microsoft Academic Search

This patent describes a bipolar metal-gas battery cell stack. The battery is composed of several electrically series-connected stacked cells each having one negative electrode and one positive electrode, wherein series electrical connections between oppositely polarized electrodes of adjacent cells are made external to the cells; means for confining electrolyte within each cell; and means for confining overcharged gasses within each

G. Van Ommering; C. W. Koehler

1986-01-01

421

Three wafer stacking for 3D integration.  

SciTech Connect

Vertical wafer stacking will enable a wide variety of new system architectures by enabling the integration of dissimilar technologies in one small form factor package. With this LDRD, we explored the combination of processes and integration techniques required to achieve stacking of three or more layers. The specific topics that we investigated include design and layout of a reticle set for use as a process development vehicle, through silicon via formation, bonding media, wafer thinning, dielectric deposition for via isolation on the wafer backside, and pad formation.

Greth, K. Douglas; Ford, Christine L.; Lantz, Jeffrey W.; Shinde, Subhash L.; Timon, Robert P.; Bauer, Todd M.; Hetherington, Dale Laird; Sanchez, Carlos Anthony

2011-11-01

422

A summer time series of particulate carbon in the air and snow at Summit, Greenland  

NASA Astrophysics Data System (ADS)

Carbonaceous particulate matter is ubiquitous in the lower atmosphere, produced by natural and anthropogenic sources and transported to distant regions, including the pristine and climate-sensitive Greenland Ice Sheet. During the summer of 2006, ambient particulate carbonaceous compounds were characterized on the Greenland Ice Sheet, including the measurement of particulate organic (OC) and elemental (EC) carbon, particulate water-soluble organic carbon (WSOC), particulate absorption coefficient (?ap), and particle size-resolved number concentration (PM0.1-1.0). Additionally, parallel ˜50-day time series of water-soluble organic carbon (WSOC), water-insoluble organic carbon (WIOC), and elemental carbon (EC) were quantified at time increments of 4-24 h in the surface snow. Measurement of atmospheric particulate carbon found WSOC (average of 52 ng m-3) to constitute a major fraction of particulate OC (average of 56 ng m-3), suggesting that atmospheric organic compounds reaching the Greenland Ice Sheet in summer are highly oxidized. Atmospheric EC (average of 7 ng m-3) was well-correlated with ?ap (r = 0.95) and the calculated mass-absorption cross-section (average of 24 m2 g-1) appears to be similar to that measured using identical techniques in an urban environment in the United States. Comparing surface snow to atmospheric particulate matter concentrations, it appears the snow has a much higher OC (WSOC+WIOC) to EC ratio (205:1) than air (10:1), suggesting that snow is additionally influenced by water-soluble gas-phase compounds. Finally, the higher-frequency (every 4-6 h) sampling of snow-phase WSOC revealed significant loss (40-54%) of related organic compounds in surface snow within 8 h of wet deposition.

Hagler, Gayle S. W.; Bergin, Michael H.; Smith, Eugene A.; Dibb, Jack E.

2007-11-01

423

Nonlinear impedances of thermoacoustic stacks with ordered and disordered structures  

NASA Astrophysics Data System (ADS)

Nonlinear impedances of two thermoacoustic stacks with ordered structures (plate-type and pipe-type) and one with a disordered structure (copper mesh) are studied. The linear resistances, nonlinear coefficients and effective acoustic masses of the stacks are extracted from the experimental results based on an analogical model of nonlinear impedances of porous materials. The resistance and nonlinear coefficient of the disordered stack are found to be much larger than those of the ordered stacks, which have similar volume porosities. In the ordered stacks, the resistance is only marginally influenced by the length of the stack, while in the disordered stack, the resistance increases significantly with the length. These characteristics of the impedances of ordered and disordered stacks are explained with the minor loss theory and the tortuosity of a stack.

Ge, Huan; Fan, Li; Xia, Jie; Zhang, Shu-Yi; Tao, Sha; Yang, Yue-Tao; Zhang, Hui

2014-07-01

424

Cross-flow, filter-sorbent catalyst for particulate, SO{sub 2} and NO{sub x} control. Sixth quarterly technical progress report  

SciTech Connect

This report describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

Benedek, K. [Little (Arthur D.), Inc., Cambridge, MA (United States); Flytzani-Stephanopoulos, M. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1991-08-01

425

Cross-flow filter-sorbent catalyst for particulate, SO{sub 2} and NO{sub x} control. Second quarter technical progress report  

SciTech Connect

This report describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

Not Available

1990-05-01

426

Asymmetrical reverse vortex flow due to induced-charge electro-osmosis around carbon stacking structures  

NASA Astrophysics Data System (ADS)

Broken symmetry of vortices due to induced-charge electro-osmosis (ICEO) around stacking structures is important for the generation of a large net flow in a microchannel. Following theoretical predictions in our previous study, we herein report experimental observations of asymmetrical reverse vortex flows around stacking structures of carbon posts with a large height (~110 ?m) in water, prepared by the pyrolysis of a photoresist film in a reducing gas. Further, by the use of a coupled calculation method that considers boundary effects precisely, the experimental results, except for the problem of anomalous flow reversal, are successfully explained. That is, unlike previous predictions, the precise calculations here show that stacking structures accelerate a reverse flow rather than suppressing it for a microfluidic channel because of the deformation of electric fields near the stacking portions; these structures can also generate a large net flow theoretically in the direction opposite that of a previous prediction for a standard vortex flow. Furthermore, by solving the one-dimensional Poisson-Nernst-Plank (PNP) equations in the presence of ac electric fields, we find that the anomalous flow reversal occurs by the phase retardation between the induced diffuse charge and the tangential electric field. In addition, we successfully explain the nonlinearity of the flow velocity on the applied voltage by the PNP analysis. In the future, we expect to improve the pumping performance significantly by using stacking structures of conductive posts along with a low-cost process.

Sugioka, Hideyuki

2011-05-01

427

Investigation of the relationship between particulate-bound mercury and properties of fly ash in a full-scale 100 MWe pulverized coal combustion boiler  

SciTech Connect

The properties of fly ash in coal-fired boilers influence the emission of mercury from power plants into the environment. In this study, seven different bituminous coals were burned in a full-scale 100 MWe pulverized coal combustion boiler and the derived fly ash samples were collected from a mechanical hopper (MH) and an electrostatic precipitator hopper (ESP). The mercury content, specific surface area (SSA), unburned carbon, and elemental composition of the fly ash samples were analyzed to evaluate the correlation between the concentration of particulate-bound mercury and the properties of coal and fly ash. For a given coal, it was found that the mercury content in the fly ash collected from the ESP was greater than in the fly ash samples collected from the MHP. This phenomenon may be due to a lower temperature of flue gas at the ESP (about 135{sup o}C) compared to the temperature at the air preheater (about 350{sup o}C). Also, a significantly lower SSA observed in MH ash might also contribute to the observation. A comparison of the fly ash samples generated from seven different coals using statistical methods indicates that the mercury adsorbed on ESP fly ashes has a highly positive correlation with the unburned carbon content, manganese content, and SSA of the fly ash. Sulfur content in coal showed a significant negative correlation with the Hg adsorption. Manganese in fly ash is believed to participate in oxidizing volatile elemental mercury (Hg{sup 0}) to ionic mercury (Hg{sup 2+}). The oxidized mercury in flue gas can form a complex with the fly ash and then get removed before the flue gas leaves the stack of the boiler.

Sen Li; Chin-Min Cheng; Bobby Chen; Yan Cao; Jacob Vervynckt; Amanda Adebambo; Wei-Ping Pan [Western Kentucky University, Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology

2007-12-15

428

An ultraviolet video technique for visualization of stack plumes and for measuring sulfur dioxide concentration and effluent velocity  

NASA Technical Reports Server (NTRS)

Absorption spectroscopy utilizing a video sensing technique was investigated as a means of visualizing SO2 in power plant stack plumes and for measuring SO2 concentration and effluent velocity in these plumes. The absorption of SO2 is measured in the ultraviolet region by using the sky as a background source. An additional spectral channel is used to correct for particulate scattering encountered in coal fired power plant plumes. The video system also tracks fluctuations in the SO2 concentration which leads to the determination of an eddy convection velocity. Field measurements were performed to show that the eddy convection velocity is proportional to the average in-stack velocity and to empirically determine their relationship. It was concluded that the video absorption technique is an attractive method for remotely determining both SO2 concentration and plume velocity with the same instrument.

Exton, R. J.

1977-01-01

429

TEST RESULTS OF HIGH TEMPERATURE STEAM/CO2 CO-ELECTROLYSIS IN A 10-CELL STACK  

SciTech Connect

High temperature coelectrolysis experiments with CO2 / H2O mixtures were performed in a 10-cell planar solid oxide stack. Results indicated that stack apparent ASR values were shown not to vary significantly between pure steam electrolysis and steam / CO2 coelectrolysis values. Product gas compositions measured via an online micro gas chromatograph (GC) showed excellent agreement to predictions obtained from a chemical equilibrium coelectrolysis model developed for this study. Experimentally determined open cell potentials and thermal neutral voltages for coelectrolysis compared favorably to predictions obtained from a chemical equilibrium coelectrolysis and energy balance model, also developed for this study.

James E. O'Brien; Joseph J. Hartvigsen

2007-06-01

430

TI-59 programmable calculator programs for in-stack opacity, venturi scrubbers, and electrostatic precipitators. User manual Jul 78-Jul 79  

SciTech Connect

The report explains the basic concepts of in-stack opacity as measured by in-stack opacity monitors. Also included are calculator programs that model the performance of venturi scrubbers and electrostatic precipitators. The effect of particulate control devices on in-stack opacity can be predicted by using these programs. The size distribution data input can be either in lognormal or histogram format. The opacity is calculated using Deirmendjian's approximation to Mie series to obtain extinction efficiencies. An alternative opacity program employing the exact Mie series solution is also described. The running time for this program is about 8 hours; that for the approximation program is 30 minutes. The accuracy of these programs is as good as the measured data input.

Cowen, S.J.; Ensor, D.S.; Sparks, L.E.

1980-05-01

431

Stack Local Packet Memory Interface Requirements  

E-print Network

or write elements in the SLPM. The tool described here ensures that information in the SLP memory-99-2-0516 Technical Report The University of Kansas #12;Abstract This thesis extends the protocol component exchange information via a mechanism called Stack Local Packet Memory (SLPM). Each component can read

Kansas, University of

432

Design of probe-fed stacked patches  

Microsoft Academic Search

In this paper, a design strategy to achieve bandwidths in excess of 25% for probe-fed stacked patches is presented. The choice of appropriate dielectric materials for such bandwidths is given and the role of each antenna parameter in controlling the impedance behavior is provided. It has been found that the selection of the substrate below the lower patch plays a

Rod B. Waterhouse

1999-01-01

433

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2013 CFR

...packaging design types other than bags must be subjected to a stacking...must be 24 hours, except that plastic drums, jerricans, and composite...than 40 °C (104 °F). Alternative test methods which yield...their position for one hour. Plastic packagings must be cooled...

2013-10-01

434

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2014 CFR

...packaging design types other than bags must be subjected to a stacking...must be 24 hours, except that plastic drums, jerricans, and composite...than 40 °C (104 °F). Alternative test methods which yield...their position for one hour. Plastic packagings must be cooled...

2014-10-01

435

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2012 CFR

...packaging design types other than bags must be subjected to a stacking...must be 24 hours, except that plastic drums, jerricans, and composite...than 40 °C (104 °F). Alternative test methods which yield...their position for one hour. Plastic packagings must be cooled...

2012-10-01

436

Stacks in canonical RNA pseudoknot structures  

E-print Network

In this paper we study the distribution of stacks in $k$-noncrossing, $\\tau$-canonical RNA pseudoknot structures ($ $-structures). An RNA structure is called $k$-noncrossing if it has no more than $k-1$ mutually crossing arcs and $\\tau$-canonical if each arc is contained in a stack of length at least $\\tau$. Based on the ordinary generating function of $$-structures \\cite{Reidys:08ma} we derive the bivariate generating function ${\\bf T}_{k,\\tau}(x,u)=\\sum_{n \\geq 0} \\sum_{0\\leq t \\leq \\frac{n}{2}} {\\sf T}_{k, \\tau}^{} (n,t) u^t x^n$, where ${\\sf T}_{k,\\tau}(n,t)$ is the number of $$-structures having exactly $t$ stacks and study its singularities. We show that for a certain parametrization of the variable $u$, ${\\bf T}_{k,\\tau}(x,u)$ has a unique, dominant singularity. The particular shift of this singularity parametrized by $u$ implies a central limit theorem for the distribution of stack-numbers. Our results are of importance for understanding the ``language'' of minimum-free energy RNA pseudoknot structures, generated by computer folding algorithms.

Hillary S. W. Han; Christian M. Reidys

2008-07-04

437

Explosive demolition of K East Reactor Stack  

SciTech Connect

Using $420,000 in Recovery Act funds, the Department of Energy and contractor CH2M HILL Plateau Remediation Company topped off four months of preparations when they safely demolished the exhaust stack at the K East Reactor and equipment inside the reactor building on July 23, 2010.

2010-07-26

438

Stacked subwavelength gratings for imaging polarimetry  

Microsoft Academic Search

The stacking of subwavelength gratings (SWG) in an integrated structure is presented for an application in imaging polarimetry. Imaging polarimetry extends the capability of conventional imaging by providing polarization information about a scene, in addition to variations in intensity. In this dissertation, a novel approach is introduced to develop a real-time imaging polarimeter. Subwavelength gratings are implemented as linear and

Panfilo Castro Deguzman

2000-01-01

439

A survey of dynamically adaptable protocol stacks  

Microsoft Academic Search

The continuous development of new networking standards over the last decade has resulted in an unprecedented proliferation of interfacing technologies and their associated protocol stacks. Never before was such a wide gamut of network architectures, protocol configurations and deployment options available to network designers. Alas, this significant increase in flexibility has come at the cost of an increased complexity in

Vangelis Gazis; Eleni Patouni; Nancy Alonistioti; Lazaros Merakos

2010-01-01

440

HTS twisted stacked-tape cable conductor  

Microsoft Academic Search

The feasibility of high field magnet applications of the twisted stacked-tape cabling method with 2G YBCO tapes has been investigated. An analysis of torsional twist strains of a thin HTS tape has been carried out taking into account the internal shortening compressive strains accompanied with the lengthening tensile strains due to the torsional twist. The model is benchmarked against experimental

Makoto Takayasu; Luisa Chiesa; Leslie Bromberg; Joseph V Minervini

2012-01-01

441

Average Transmission Probability of a Random Stack  

ERIC Educational Resources Information Center

The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower…

Lu, Yin; Miniatura, Christian; Englert, Berthold-Georg

2010-01-01

442

Advanced piezoelectric–ferroelectric stack actuator  

Microsoft Academic Search

A conceptual design and an operational algorithm for an advanced piezoelectric–ferroelectric stack actuator are developed. The actuator takes advantage of the large strains due to the domain-switching phenomenon and utilizes the nonlinear range of response of the ferroelectric material. As a result, the proposed conceptual design allows for deformations that are considerably larger than the ones obtained using conventional piezoelectric

Uri Kushnir; Oded Rabinovitch

2009-01-01

443

Higher and derived stacks: a global overview  

Microsoft Academic Search

These are expended notes of my talk at the summer institute in algebraic geometry (Seattle, July-August 2005), whose main purpose is to present a global overview on the theory of higher and derived stacks. This text is far from being exhaustive but is intended to cover a rather large part of the subject, starting from the motivations and the foundational

Bertrand Toen

2006-01-01

444

Explosive demolition of K East Reactor Stack  

ScienceCinema

Using $420,000 in Recovery Act funds, the Department of Energy and contractor CH2M HILL Plateau Remediation Company topped off four months of preparations when they safely demolished the exhaust stack at the K East Reactor and equipment inside the reactor building on July 23, 2010.

None

2010-09-02

445

MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ''Advanced Hybrid''{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultra-high collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control.

Ye Zhuang; Stanley J. Miller; Steven A. Benson; Michelle R. Olderbak

2003-08-01

446

MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ADVANCED HYBRID{trademark} Filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control.

Stanley J. Miller; Ye Zhuang; Michelle R. Olderbak

2002-11-01

447

3-D CFD MODEL OF A MULTI-CELL HIGH TEMPERATURE ELECTROLYSIS STACK  

SciTech Connect

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory (INL) Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc. and tested at INL. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density, and hydrogen production over a range of stack operating conditions. Variations in flow distribution and species concentration are discussed. End effects of flow and per-cell voltage are also considered.

Grant Hawkes; James O'Brien; Carl Stoots; Brian Hawkes

2009-05-01

448

3D CFD Model of a Multi-Cell High Temperature Electrolysis Stack  

SciTech Connect

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc1. and tested at the Idaho National Laboratory. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC userdefined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation overpotential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered.

G.L. Hawkes; J. E. O'Brien; C. M. Stoots

2007-11-01

449

Biotransformation of sulfur and nitrogen oxides in stack gases  

SciTech Connect

The Nation`s large supply of high sulfur coal and increasingly stringent emission regulation led to priority development of advanced innovative processes for treating pollutants in flue gases from coal combustion. The principal pollutants in flue gases, sulfur oxides (SO{sub 2},SO{sub 3}) and nitrogen oxides (NO{sub x}) cause acid rain. Thus, the Department of Energy`s Clean Coal Program is funding projects to commercialize technologies that minimize emission of sulfur and nitrogen oxides at power plants. This report describes the controlled use of bioconversion processes to remove the oxides from flue gas. Two bioreactor experiments were conducted to investigate the removal of sulfur dioxide, nitrogen oxides, and carbon dioxide from stack gases.

Govind, R.; Puligadda, R. [Univ. of Cincinnati, OH (United States); Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States)

1995-10-01

450

Antiproton stacking and un-stacking in the Fermilab Recycler Ring  

SciTech Connect

The Fermilab Recycler Ring (RR) is intended to be used as a future antiproton storage ring for the Run II proton-antiproton collider operation. It is proposed that about 40mA of antiproton beam from the Accumulator Ring will be transferred to the Recycler once for every two to three hours, stacked and cooled. This operation continues for about 10 to 20 hours depending on the collider needs for antiprotons. Eventually, the cooled antiproton beam will be un-stacked from the Recycler and transferred to the Tevatron via the Main Injector. They have simulated stacking and un-stacking of antiprotons in the Recycler using multi-particle beam dynamics simulation code ESME. In this paper they present results of these simulations.

Chandra Bhat

2003-06-12

451

Electrically heated particulate filter enhanced ignition strategy  

DOEpatents

An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating applied to at least one of the PF and the grid. A control module estimates a temperature of the grid and controls the engine to produce a desired exhaust product to increase the temperature of the grid.

Gonze, Eugene V; Paratore, Jr., Michael J

2012-10-23

452

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height...EPA's modified requirements. The State of Montana agrees to make the appropriate...

2012-07-01

453

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height...EPA's modified requirements. The State of Montana agrees to make the appropriate...

2010-07-01

454

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height...EPA's modified requirements. The State of Montana agrees to make the appropriate...

2011-07-01

455

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height...EPA's modified requirements. The State of Montana agrees to make the appropriate...

2013-07-01

456

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2014 CFR

...OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height...EPA's modified requirements. The State of Montana agrees to make the appropriate...

2014-07-01

457

Solid Oxide Fuel Cell Balance of Plant & Stack Component Integration  

E-print Network

the efficiency of equivalent generatorsTwice the efficiency of equivalent generators Stacks during assembly Micro #12;Stack Size Reduction Number of tubes for 1.25 kW reduced from 126 to 72 to 45 Weight reduced 75

458

Products and kinetics of the heterogeneous reaction of particulate ametryn with NO3 radicals.  

PubMed

As a renowned s-triazine herbicide, ametryn is worldwide emitted into the atmosphere in both gaseous and particulate phases via spray drifts from treatments and post application emissions, but its chemical degradation in the atmosphere has not been well characterized. In this study, the heterogeneous kinetics of particulate ametryn with NO3 radicals were investigated with a mixed-phase relative rate method. A vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS) and an atmospheric gas analysis mass spectrometer were synchronously used to online monitor the decays of particulate ametryn and gas-phase isoprene. The reactive uptake coefficient of NO3 radicals on ametryn particles was calculated to be 2.9 × 10(-2), according to the measured ametryn loss ratio and the average NO3 concentration. The effective rate constant for the heterogeneous reaction of particulate ametryn with NO3 radicals measured under experimental conditions was 8.4 × 10(-13) cm(3) molecule(-1) s(-1). In addition, atraton, ametryn sulfoxide and ametryn sulfone were identified as the reaction products by gas-chromatography-mass spectrometry (GC-MS) analysis. The experimental results might shed light on the chemical behavior of atmospheric ametryn at night-time. PMID:25301341

Liu, Chang-Geng; Shu, Ji-Nian; Yang, Bo; Zhang, Peng

2014-12-01

459

Aero-dispersed mutagenicity attributed to particulate and semi volatile phase in an urban environment.  

PubMed

Commonly the atmospheric pollution research is focussed on particulate indicators especially when mutagenicity was studied. On the other hand the volatile and semi-volatile compounds no adsorbed on to the particles can be genotoxic and mutagenic. Moreover some mutagenic compounds, such as polycyclic aromatic hydrocarbons, are present both in the particulate and in the gas-phase in according to chemical conditions. This work is focussed on the assessing of the total mutagenicity shifting the gas-phase and particulate phase, during two seasons, in Turin. Two sampling sessions are conducted for total particulate matter and gas-phase pollutants. Moreover meteorological and usual air pollution monitoring data were collected at the same sampling station. The Salmonella assay using the strains TA98 and YG1021 was conducted on each organic extract. The mean level of total suspended particles, PM10 and PM2.5 were 73.63±26.94, 42.85±26.75 and 31.55±26.35?gm(-)(3). The observed mutagenicity was PM induced YG1021>PM induced TA98>PM induced TA98+S9?non-particle induced YG1021>non-particle induced TA98>non-particle induced TA98+S9. The multivariate regression is significant when we consider air pollution and meteorological indicators and chemical conditions as predictors. PMID:25563164

Traversi, Deborah; Festa, Evelina; Pignata, Cristina; Gilli, Giorgio

2015-04-01

460

Review - Turbomachinery performance deterioration exposed to solid particulates environment  

NASA Astrophysics Data System (ADS)

The objective of this paper is to review experimental and analytical investigations concerning the effect of the presence of solid particles on the performance of turbomachines. Experimental data on the effect of solid particles on turbine and compressor performance are examined. Some basic data have been reinterpreted to provide guidance for future design. The equations that govern the dynamics of the three-dimensional motion of solid particles suspended in compressible gas flow through a rotating cascade of a turbine are discussed. The results obtained from the solution of these equations are presented to indicate the location on the turbine blade subjected to erosion damage. Some erosion data relevant to gas turbine engines are discussed. The concluding remarks include a global view of the state of the art of particulate flow problems in turbomachinery.

Tabakoff, W.

1984-06-01

461

Collective migration Inertial migration Transition to turbulence Particulate flow  

E-print Network

to turbulence Particulate flow in a pipe Rigid spherical particles Neutrally-buoyant particles Particulate flow Collective migration of rigid spherical particles in pipe flow Inertial migration of rigid spherical particles in pipe flow Transition to turbulence in particulate pipe flow Particulate flow IUSTI - CNRS

462

Development of an internal reforming molten carbonate fuel cell stack  

Microsoft Academic Search

The development of an internal reforming molten carbonate fuel cell (IR-MCFC) has been in process of test generation of 10-100 kW class stack. This paper reports the test results of 30 kW and 10 kW stacks. In the 30 kW stack, reforming catalyst is directly provided in the anode flow path. The stack demonstrates highly stable characteristics including internal reforming

T. Shinoki; M. Matsumura; A. Sasaki

1995-01-01

463

40 CFR 52.2633 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.2633 Section 52...CONTINUED) Wyoming § 52.2633 Stack height regulations. In a letter dated...the State committed to conduct stack height evaluations in accordance with...

2010-07-01

464

40 CFR 52.1034 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.1034 Section 52.1034...CONTINUED) Maine § 52.1034 Stack height review. The State of Maine has declared...limitations have been affected by stack height credits greater than good...

2010-07-01

465

40 CFR 52.2534 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.2534 Section 52.2534... West Virginia § 52.2534 Stack height review. The State of West Virginia...power plant, have been affected by stack height credits greater than good...

2010-07-01

466

40 CFR 52.2384 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.2384 Section 52.2384...CONTINUED) Vermont § 52.2384 Stack height review. The State of Vermont has...limitations have been affected by stack height credits greater than good...

2010-07-01

467

40 CFR 52.1832 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.1832 Section...North Dakota § 52.1832 Stack height regulations. The State of North Dakota has committed to revise its stack height regulations should EPA complete...

2010-07-01

468

40 CFR 52.2085 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.2085 Section 52.2085... Rhode Island § 52.2085 Stack height review. The State of Rhode Island...limitations have been affected by stack height credits greater than good...

2010-07-01

469

40 CFR 52.1169 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.1169 Section 52.1169... Massachusetts § 52.1169 Stack height review. The Commonwealth of Massachusetts...limitations have been affected by stack height credits greater than good...

2010-07-01

470

40 CFR 51.164 - Stack height procedures.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height procedures. 51.164 Section 51...and Modifications § 51.164 Stack height procedures. Such procedures must...affected by so much of any source's stack height that exceeds good engineering...

2010-07-01

471

40 CFR 52.2180 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.2180 Section...South Dakota § 52.2180 Stack height regulations. The State of South Dakota has committed to revise its stack height regulations should EPA complete...

2010-07-01

472

40 CFR 51.118 - Stack height provisions.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height provisions. 51.118 Section 51... Control Strategy § 51.118 Stack height provisions. (a) The plan must...affected by so much of any source's stack height that exceeds good engineering...

2010-07-01

473

40 CFR 52.383 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.383 Section 52.383...PLANS Connecticut § 52.383 Stack height review. The State of Connecticut...limitations have been affected by stack height credits greater than good...

2010-07-01

474

High temperature molten salt bipolar stacked module battery  

Microsoft Academic Search

This patent describes a high temperature molten salt bipolar stacked module battery. It includes multiple cell module stack, each of the cell modules including, an anode disk, a separator disk atop the anode disk, a cathode disk atop the separator disk, and a current collector disk atop the cathode disk, the electrode disks and current collectors being stacked inside of

E. J. Plichta; W. K. Behl

1992-01-01

475

Erosion of a Sea Stack Over 100 Years  

NSDL National Science Digital Library

This United States Geological Survey (USGS) publication shows photographs exhibiting the demise of Jump-off Joe, a sea stack at Nye Beach, Newport, Oregon. In 1890, the sea stack was composed of middle Miocene concretionary sandstone of the Astoria Formation. The photos continue through 1990 when the sea stack is entirely gone.

Snavely, Park

476

40 CFR 52.2085 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.2085 Section 52.2085... Rhode Island § 52.2085 Stack height review. The State of Rhode Island...limitations have been affected by stack height credits greater than good...

2011-07-01

477

40 CFR 52.1034 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.1034 Section 52.1034...CONTINUED) Maine § 52.1034 Stack height review. The State of Maine has declared...limitations have been affected by stack height credits greater than good...

2011-07-01

478

40 CFR 52.2534 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.2534 Section 52.2534... West Virginia § 52.2534 Stack height review. The State of West Virginia...power plant, have been affected by stack height credits greater than good...

2013-07-01

479

40 CFR 52.2534 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.2534 Section 52.2534... West Virginia § 52.2534 Stack height review. The State of West Virginia...power plant, have been affected by stack height credits greater than good...

2011-07-01

480

40 CFR 51.118 - Stack height provisions.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height provisions. 51.118 Section 51... Control Strategy § 51.118 Stack height provisions. (a) The plan must...affected by so much of any source's stack height that exceeds good engineering...

2014-07-01

481

40 CFR 52.383 - Stack height review.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height review. 52.383 Section 52.383...PLANS Connecticut § 52.383 Stack height review. The State of Connecticut...limitations have been affected by stack height credits greater than good...

2012-07-01

482

40 CFR 52.2180 - Stack height regulations.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height regulations. 52.2180 Section...South Dakota § 52.2180 Stack height regulations. The State of South Dakota has committed to revise its stack height regulations should EPA complete...

2014-07-01

483

40 CFR 52.383 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.383 Section 52.383...PLANS Connecticut § 52.383 Stack height review. The State of Connecticut...limitations have been affected by stack height credits greater than good...

2013-07-01

484

40 CFR 52.1169 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.1169 Section 52.1169... Massachusetts § 52.1169 Stack height review. The Commonwealth of Massachusetts...limitations have been affected by stack height credits greater than good...

2011-07-01

485

40 CFR 52.2384 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.2384 Section 52.2384...CONTINUED) Vermont § 52.2384 Stack height review. The State of Vermont has...limitations have been affected by stack height credits greater than good...

2013-07-01

486

40 CFR 52.2180 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height regulations. 52.2180 Section...South Dakota § 52.2180 Stack height regulations. The State of South Dakota has committed to revise its stack height regulations should EPA complete...

2011-07-01

487

40 CFR 52.383 - Stack height review.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height review. 52.383 Section 52.383...PLANS Connecticut § 52.383 Stack height review. The State of Connecticut...limitations have been affected by stack height credits greater than good...

2014-07-01

488

40 CFR 52.2384 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.2384 Section 52.2384...CONTINUED) Vermont § 52.2384 Stack height review. The State of Vermont has...limitations have been affected by stack height credits greater than good...

2011-07-01

489

40 CFR 52.1832 - Stack height regulations.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height regulations. 52.1832 Section...North Dakota § 52.1832 Stack height regulations. The State of North Dakota has committed to revise its stack height regulations should EPA complete...

2014-07-01

490

40 CFR 52.1832 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height regulations. 52.1832 Section...North Dakota § 52.1832 Stack height regulations. The State of North Dakota has committed to revise its stack height regulations should EPA complete...

2011-07-01

491

40 CFR 51.164 - Stack height procedures.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height procedures. 51.164 Section 51...and Modifications § 51.164 Stack height procedures. Such procedures must...affected by so much of any source's stack height that exceeds good engineering...

2013-07-01

492

40 CFR 52.383 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.383 Section 52.383...PLANS Connecticut § 52.383 Stack height review. The State of Connecticut...limitations have been affected by stack height credits greater than good...

2011-07-01

493

40 CFR 52.2085 - Stack height review.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Stack height review. 52.2085 Section 52.2085... Rhode Island § 52.2085 Stack height review. The State of Rhode Island...limitations have been affected by stack height credits greater than good...

2014-07-01

494

40 CFR 52.2384 - Stack height review.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height review. 52.2384 Section 52.2384...CONTINUED) Vermont § 52.2384 Stack height review. The State of Vermont has...limitations have been affected by stack height credits greater than good...

2012-07-01

495

40 CFR 52.1034 - Stack height review.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height review. 52.1034 Section 52.1034...CONTINUED) Maine § 52.1034 Stack height review. The State of Maine has declared...limitations have been affected by stack height credits greater than good...

2012-07-01

496

40 CFR 52.1034 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.1034 Section 52.1034...CONTINUED) Maine § 52.1034 Stack height review. The State of Maine has declared...limitations have been affected by stack height credits greater than good...

2013-07-01

497

40 CFR 52.2085 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.2085 Section 52.2085... Rhode Island § 52.2085 Stack height review. The State of Rhode Island...limitations have been affected by stack height credits greater than good...

2013-07-01

498

40 CFR 51.118 - Stack height provisions.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height provisions. 51.118 Section 51... Control Strategy § 51.118 Stack height provisions. (a) The plan must...affected by so much of any source's stack height that exceeds good engineering...

2011-07-01

499

40 CFR 52.2180 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height regulations. 52.2180 Section...South Dakota § 52.2180 Stack height regulations. The State of South Dakota has committed to revise its stack height regulations should EPA complete...

2013-07-01

500

40 CFR 52.2633 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height regulations. 52.2633 Section 52...CONTINUED) Wyoming § 52.2633 Stack height regulations. In a letter dated...the State committed to conduct stack height evaluations in accordance with...

2012-07-01