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1

Cooler and particulate separator for an off-gas stack  

DOEpatents

This report describes an off-gas stack for a melter, furnace or reaction vessel comprising an air conduit leading to two sets of holes, one set injecting air into the off-gas stack near the melter plenum and the second set injecting air downstream of the first set. The first set injects air at a compound angle, having both downward and tangential components, to create a reverse vortex flow, counter to the direction of flow of gas through the stack and also along the periphery of the stack interior surface. Air from the first set of holes prevents recirculation zones from forming and the attendant accumulation of particulate deposits on the wall of the stack and will also return to the plenum any particulate swept up in the gas entering the stack. The second set of holes injects air in the same direction as the gas in the stack to compensate for the pressure drop and to prevent the concentration of condensate in the stack. A set of sprayers, receiving water from a second conduit, is located downstream of the second set of holes and sprays water into the gas to further cool it.

Wright, G.T.

1991-04-08

2

On-line measurement of stack-gas particulate radionuclides  

SciTech Connect

This paper describes an advanced process-monitoring system for the automatic sample collection, analysis, reporting, and alarming of the concentration of long-lived radionuclides in nuclear process stack-gas effluents. This system, the Moving Filter Radioactive Aerosol Monitor, collects particulates in a conditioned sampling chamber, under computer control, for subsequent and separate alpha and beta counting and analysis. The alpha measurement is performed with a solid-state surface-barrier detector. Beta analysis is performed with a phoswich scintillation detector. A unique alpha-energy analysis program that provides automatic energy calibration and lowered detection limits for plutonium in the presence of high quantities of interfering /sup 212/Bi/Po is described. The /sup 212/Bi/Po alpha results are further used to monitor system quality and to compensate for the radon daughter beta components in the beta system. Results of the system calibration and detection limits are also presented. 8 refs., 6 figs.

Stong, F.S.; Troyer, G.L.; Criddle, J.D. Jr.

1987-11-01

3

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 ...

4

In-stack condensible particulate matter measurements and issues.  

PubMed

Particulate matter (PM) emitted from fossil fuel-fired units can be classified as either filterable or condensible PM. Condensible PM typically is not measured because federal and most state regulations do not require sources to do so. To determine the magnitude of condensible PM emissions relative to filterable PM emissions and to better understand condensible PM measurement issues, a review and analysis of actual U.S. Environmental Protection Agency (EPA) Method 202 (for in-stack condensible PM10) and EPA Method 201/201A (for in-stack filterable PM10) results were conducted. Methods 202 and 201/201A results for several coal-burning boilers showed that the condensible PM, on average, comprises approximately three-fourths (76%) of the total PM10 stack emissions. Methods 202 and 201/201A results for oil- and natural gas-fired boilers showed that the condensible PM, on average, comprises 50% of the total PM10 stack emissions. Methods 202 and 201/201A results for oil-, natural gas-, and kerosene-fired combustion turbines showed that the condensible PM, on average, comprises 69% of the total PM10 stack emissions. Based on these limited measurements, condensible PM can make a significant contribution to total PM10 emissions for fossil fuel-fired units. A positive bias (indicating more condensible PM than is actually emitted) may exist in the measured data due to the conversion of dissolved sulfur dioxide to sulfate compounds in the sampling procedure. In addition, these Method 202 results confirm that condensible PM, on average, is composed mostly of inorganic matter, regardless of the type of fuel burned. PMID:10680350

Corio, L A; Sherwell, J

2000-02-01

5

Method and apparatus for removing particulate pollutants from stack gases  

Microsoft Academic Search

A pollution control system is described for reducing the presence of fine aerosol particles in stack gases from the manufacture of glass fiber wool-type products. After larger particles are removed from the forming fan gas, the gas is fed into a centrifugal fan and massive quantities of water are injected into the fan intake. The aerosol particles are agglomerated by

Langlois

1977-01-01

6

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

7

Intercomparison of stack gas mercury measurement methods  

Microsoft Academic Search

The Electric Power Research Institute (EPRI) and the United States Environmental Protection Agency (EPA) have carried out joint tests for validation of EPA (Draft) Method 29 (“multi-metals method”) for measurement of mercury (Hg) and other selected metals in the stack gas of a coal-fired electric utility. The tests were performed according to the “analyte spiking” procedure of EPA Method 301

Babu R. Nott

1995-01-01

8

Process for stack gas desulfurization  

Microsoft Academic Search

A method is described for desulfurizing a gaseous mixture such as flue gas by sequentially contacting the gaseous mixture with an aqueous solution containing ammonium thiosulfate in a first zone; an aqueous solution containing ammonia and ammonium thiosulfate in a second zone; and an aqueous solution containing ammonium thionate or thionic acid in a third zone. The sulfur is optionally

M. D. Kulik; E. Gorin

1979-01-01

9

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....

10

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

11

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

12

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes summaries of analyses performed on particulate samples from Sierra Pacific Power Company's Pinon Pine Power Project. This report also reviews the status of the HGCU data bank of ash and char characteristics, and plans for enhancing the data bank with interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

NONE

1999-05-01

13

Process for off-gas particulate removal and apparatus therefor  

DOEpatents

In the event of a breach in the off-gas line of a melter operation requiring closure of the line, a secondary vessel vent line is provided with a particulate collector utilizing atomization for removal of large particulates from the off-gas. The collector receives the gas containing particulates and directs a portion of the gas through outer and inner annular channels. The collector further receives a fluid, such as water, which is directed through the outer channel together with a second portion of the particulate-laden gas. The outer and inner channels have respective ring-like termination apertures concentrically disposed adjacent one another on the outer edge of the downstream side of the particulate collector. Each of the outer and inner channels curves outwardly away from the collector`s centerline in proceeding toward the downstream side of the collector. Gas flow in the outer channel maintains the fluid on the channel`s wall in the form of a ``wavy film,`` while the gas stream from the inner channel shears the fluid film as it exits the outer channel in reducing the fluid to small droplets. Droplets formed by the collector capture particulates in the gas stream by one of three mechanisms: impaction, interception or Brownian diffusion in removing the particulates. The particulate-laden droplets are removed from the fluid stream by a vessel vent condenser or mist eliminator. 4 figs.

Carl, D.E.

1997-10-21

14

Stack Gas Heat Recovery from 100 to 1200 HP Boilers  

E-print Network

STACK GAS HEAT RECOVERY FROM 100 TO 1200 HP BOILERS Thomas H. Judson Peabody Gordon-Piatt, Inc. Walnut Creek, CA ABSTRACT With newspaper reports of March 1980 fuel price increases at as much as a 110% annualized rate, ener~y users...quidboller I I more closely at boiler stack gas heat recovery for heat recovery unit, trade marked the HEATMIZER. THe energy conservation ip 1975. unit was "packaged" as a system for ease of applic L Our investigation verified by initial installa tion...

Judson, T. H.

1980-01-01

15

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

16

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

17

Process for off-gas particulate removal and apparatus therefor  

DOEpatents

In the event of a breach in the off-gas line of a melter operation requiring closure of the line, a secondary vessel vent line is provided with a particulate collector utilizing atomization for removal of large particulates from the off-gas. The collector receives the gas containing particulates and directs a portion of the gas through outer and inner annular channels. The collector further receives a fluid, such as water, which is directed through the outer channel together with a second portion of the particulate-laden gas. The outer and inner channels have respective ring-like termination apertures concentrically disposed adjacent one another on the outer edge of the downstream side of the particulate collector. Each of the outer and inner channels curves outwardly away from the collector's centerline in proceeding toward the downstream side of the collector. Gasflow in the outer channel maintains the fluid on the channel's wall in the form of a "wavy film," while the gas stream from the inner channel shears the fluid film as it exits the outer channel in reducing the fluid to small droplets. Droplets formed by the collector capture particulates in the gas stream by one of three mechanisms: impaction, interception or Brownian diffusion in removing the particulates. The particulate-laden droplets are removed from the fluid stream by a vessel vent condenser or mist eliminator.

Carl, Daniel E. (Orchard Park, NY)

1997-01-01

18

Particulate emissions from gas turbine engines. Revision  

SciTech Connect

The Aircraft Environmental Support Office is one of four specialty offices within the Naval Environmental Protection Support Service which offers technical support to the naval community. The Aircraft Environmental Support office is primarily responsible for the management and distribution of emissions data for gaseous and particulate air pollutants from aircraft engines. This handbook, Particulate Emissions From Aircraft Engines, is a summary of particulate emissions data collected by the Aircraft Environmental Support Office since 1981. This handbook is intended for environmental personnel at military installations who must provide regulatory agencies with information about particulate matter emitted from their engine test facilities. Most users will find that the sections on visible emissions and particulate emission rates and concentrations contain all the information normally required to make permit applications, emission inventories and related regulatory documents. Also, the section on particle size distributions is appropriate to design applications. Together these sections provide a comprehensive treatment of particulate emissions from aircraft engines.

Not Available

1992-02-01

19

Exhaust gas filter apparatus capable of regeneration of a particulate filter and method  

SciTech Connect

An exhaust gas filter apparatus includes a particulate filter for collecting a particulate from an exhaust gas. The exhaust gas filter also includes a electromagnetic radiation resonator to heat a portion of the particulate to ignite the particulate and regenerate the particulate filter.

Phelps, Amanda C [Malibu, CA; Kirby, Kevin W [Calabasas Hills, CA; Gregoire, Daniel [Thousand Oaks, CA

2009-04-07

20

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report reviews the status of the HGCU data bank of ash and char characteristics, including the interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank, and issuance of a comprehensive final report on activities conducted under Task 1. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

D.H. Pontius

1999-08-30

21

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

22

Ceramic filters for removal of particulates from hot gas streams  

SciTech Connect

The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an air to cloth ratio'') for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.

Goldsmith, R.L.

1992-01-01

23

Ceramic filters for removal of particulates from hot gas streams  

SciTech Connect

The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an ``air to cloth ratio``) for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.

Goldsmith, R.L.

1992-11-01

24

Prototype particle stack sampler with virtual impactor nozzle and microcomputer calculating/display system. [H5 Stack Particulate Sampler/Calculator  

SciTech Connect

A prototype particle stack sampler (PPSS) was developed to improve on the existing Environmental Protection Agency (EPA) Method 5 sampling apparatus. Primary features of the stack sampler were: higher sampling rate; display (on demand) of all required variables and calculated values by a microcomputer-based calculating and display system; continuous stack gas moisture determination; a virtual impactor nozzle designed to separate fine and coarse particle fractions; a variable-area inlet to maintain isokinetic sampling conditions; and stainless-steel components rather than the glass specified by EPA Method 5. The calculating and display system incorporates a single component microcomputer, a single-chip 16-channel analog-to-digital converter, a programmable keyboard/display interface, and liquid crystal displays. The scientific calculations capability and associated display have been incorporated to perform and display the results of 24 equations. These results allow the operator to maintain isokinetic sampler probe temperatures, to maintain proper flow through the sampler probe, and to make sampler probe position changes when necessary. The basic sampling technique of particle collection on preweighed filters was retained; however, versatility in the form of optional in-stack filters and general modernization of the stack sampler have been provided in the prototype design. Laboratory testing with monodisperse dye aerosols has shown the present variable-inlet, virtual impactor nozzle to have significant wall losses and a collection efficiency that is less than 77%. This is primarily due to lack of symmetry in this rectangular jet impactor and short transition lengths dictated by physical design constraints (required by passage of the nozzle through a 7.6-cm (3-in.) diameter stack port). Electronic components have shown acceptable service in laboratory testing.

Elder, J.C.; Littlefield, L.G.; Tillery, M.I.; Ettinger, H.J.

1981-07-01

25

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...

26

Rotary device for removing particulates from a gas stream  

NASA Technical Reports Server (NTRS)

A rotary particulate separator for removing particulates from a pressurized gas stream such as that emanating from a reactor vessel is disclosed which precharges the particles in the gas stream, and then utilizes the charge on the particles to induce them from the main flow path through an airblock and into the rotary particulate separator. The rotor of the rotary particulate separator has polarized plates which use a first charge opposite that on the charged particles to attract the particles as they enter the rotation chamber, and then use a second charge of the same polarity as the charge on the charged particles to release the particles into a control gas flow vortex which draws the particles radially inwardly into an exit aperture contained in the center of one of the rotor segments and out from the device. Pressure letdown devices are used to drop the pressure of both the control gas flow exiting the separator with the particles and the cleaned gas stream.

Collins, Jr., Earl R. (Inventor)

1992-01-01

27

[Genotoxicity of stack gas condensates of Bavarian waste incineration plants. I. Stack gas condensate--sample collection techniques].  

PubMed

Investigations into the toxicity and the chemical analytics of stack gas condensates from 21 waste incineration plants (locations in Bavaria) were undertaken in the years 1990 to 1995. A decisive prerequisite was the development of a simple, standardizable technique for sample collection. It was done by condensating stack gases at 0 to 5 degrees C in an intensive glass condensator. Certain types of compounds showed a different behaviour of separation at the temperatures which were used. Whereas bivalent ionic mercury and chlorophenols were comparatively well separated with amounts of 60 to 95% and the polychlorinated dioxins, furans and biphenyls (PCBs) were sufficiently separated with 20 to 60%, less than 10% of the chlorobenzenes and polycyclic aromatics (PAHs) were found in the condensates. Sufficiently sensitive biological test procedures must be chosen for a biomonitoring of the condensates on geno- and immunotoxic effects to keep the required quantity of the condensates within practicable limits. The concentration of organic wastes was done through a solid phase extraction for the genotoxicity testing in the period from 1990 to 1991, and uniformly through a dichloromethane extraction for the biological and the simultaneous chemical analytical investigations from 1992 to 1995. PMID:10084203

Raabe, F; Brandl, A; Strobl, J; Dautzenberg, D; Lierse, C; Wichmann, G; Mücke, W

1999-02-01

28

Distribution of gas flow in internally manifolded solid oxide fuel-cell stacks  

Microsoft Academic Search

In internally manifolded fuel-cell stacks, there is a non-uniform gas flow distribution along the height of the system. To gain an insight into this distribution an analytical model has been developed. In the model, the stack is viewed as a network of hydraulic resistances. Some of these resistances are constant, while some depend upon the gas velocity and can be

R. J. Boersma; N. M. Sammes

1997-01-01

29

Particulate exhaust emissions from an experimental combustor. [gas turbine engine  

NASA Technical Reports Server (NTRS)

The concentration of dry particulates (carbon) in the exhaust of an experimental gas turbine combustor was measured at simulated takeoff operating conditions and correlated with the standard smoke-number measurement. Carbon was determined quantitatively from a sample collected on a fiberglass filter by converting the carbon in the smoke sample to carbon dioxide and then measuring the volume of carbon dioxide formed by gas chromatography. At a smoke of 25 (threshold of visibility of the smoke plume for large turbojets) the carbon concentration was 2.8 mg carbon/cu m exhaust gas, which is equivalent to an emission index of 0.17 g carbon/kg fuel.

Norgren, C. T.; Ingebo, R. D.

1975-01-01

30

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

Microsoft Academic Search

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report reviews the status of the HGCU data bank

D. H. Pontius

1999-01-01

31

Measurement of Opacity and Particulate Emissions With an On-Stack Transmissometer  

ERIC Educational Resources Information Center

An on-stack transmissometer system, that is designed to provide a precision measurement of the opacity of visible emissions, is described. The sources of error in opacity measurements with regard to recent Environmental Protection Agency emission monitoring requirements and planned specifications are discussed. (Author/BT)

Beutner, Heinz P.

1974-01-01

32

Particulate Hot Gas Stream Cleanup Technical Issues  

SciTech Connect

The nature of the collected ash has been identified as an issue creating barriers to the commercialization of advanced particle control technologies. Since most of the emphasis and extended operation of Hot Gas Stream Cleanup (HGCU) facilities have been with ceramic candle filters, problems with ash characteristics can be understood in terms of their effects on these control devices. This project is designed to identify the ways ash characteristics affect advanced particle control technologies, to construct and maintain a data base of HGCU ashes and their measured characteristics, and to relate these characteristics to the operation and performance of these facilities. The key characteristics of the collected ash are the morphology of the overall ash aggregate (porosity, geometry of the pores, specific surface area, etc.), and the cohesivity of the aggregate. Our data base currently comprises 242 ash samples from 12 combustion and gasification (HGCU) sources.

Dorchak, T.P. [USDOE Morgantown Energy Technology Center, WV (United States); Pontiu, D.H.; Snyder, T.R. [Southern Research Institute, Birmingham, AL (United States)

1996-12-31

33

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

34

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes a description of a device developed to harden a filter cake on a filter element so that the element and cake can subsequently be encapsulated in epoxy and studied in detail. This report also reviews the status of the HGCU data base of ash and char characteristics. Task 1 plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF), encapsulation of an intact filter cake from the PSDF, and completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter consisted of hoop tensile and axial compressive stress-strain responses of McDermott ceramic composite and hoop tensile testing of Techniweave candle filters as-manufactured and after exposure to the gasification environment.

None

1999-02-26

35

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This is the fourth annual report describing the activities performed under Task 1 of 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. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97 ® . Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy / Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

None

1999-05-05

36

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This is the fourth annual report describing the activities performed under Task 1 of 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. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97 ® . Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy / Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

NONE

1998-11-30

37

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This is the fourth annual report describing the activities performed under Task 1 of 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. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97{reg_sign}. Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy/Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

NONE

1999-05-05

38

Particulate hot gas stream cleanup technical issues  

SciTech Connect

This is the thirteenth 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 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 I research activities during the past quarter included characterizations of additional ash samples from Pressurized Fluidized-Bed Combustion (PFBC) facilities to the HGCU data base. Task I plans for the next quarter include characterization of samples collected during a site visit on January 20 to the Department of Energy / Southern Company Services Power Systems Development Facility (PSDF). Further work on the HGCU data base is also planned. Task 2 work during the past quarter included creep testing of a Coors P- I OOA- I specimen machined from Candle FC- 007 after 1166 hours in-service at the Karhula Pressurized Circulating Fluid Bed (PCFB) facility. Samples are currently in preparation for microstructural evaluations of Coors P-IOOA-I.Sixteen cordierite rings manufactured by Specific Surfaces were received for testing. Three of the specimens were exposed to the PFBC environment at the PSDF. These specimens are currently being machined for testing.

NONE

1998-09-01

39

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

Microsoft Academic Search

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

J. J. Nainiger

1980-01-01

40

Networked solid oxide fuel cell stacks combined with a gas turbine cycle  

NASA Astrophysics Data System (ADS)

An improved design of fuel cells stacks arrangement has been suggested before for MCFC where reactant streams are ducted such that they are fed and recycled among multiple MCFC stacks in series. By networking fuel cell stacks, increased efficiency, improved thermal balance, and higher total reactant utilisation can be achieved. In this study, a combination of networked solid oxide fuel cell (SOFC) stacks and a gas turbine (GT) has been modelled and analysed. In such a combination, the stacks are operating in series with respect to the fuel flow. In previous studies, conducted on hybrid SOFC/GT cycles by the authors, it was shown that the major part of the output of such cycles can be addressed to the fuel cell. In those studies, a single SOFC with parallel gas flows to individual cells were assumed. It can be expected that if the performance of the fuel cell is enhanced by networking, the overall system performance will improve. In the first part of this paper, the benefit of the networked stacks is demonstrated for a stand alone stack while the second part analyses and discusses the impact networking of the stacks has on the SOFC/GT system performance and design. For stacks with both reactant streams in series, a significant increase of system efficiency was found (almost 5% points), which, however, can be explained mainly by an improved thermal management.

Selimovic, Azra; Palsson, Jens

41

Energy Economizer for Low Temperature Stack Gas: A Case Study  

E-print Network

system was designed by BETC engineers. The new stack assembly was fabricated by a local metal shop, and was installed by BETC maintenance personnel. The cost of the heat exchanger and other hard-ware was $7,562. Operational results show that boiler...

Tipton, J. A.

1979-01-01

42

Feasibility of an alpha particle gas densimeter for stack sampling applications  

E-print Network

LISTING APPENDIX C TABULATED RESULTS 58 60 72 VI TA 84 Vi LIST OF TABLES TABLE P age I Typical Flue Gas Compositions II Model Flue Gas Compositions 35 Coeff icients for Alpha particle Stopping Power Functions 59 Computed and Experimental... is obtained using a Type S Pitot. Tube, described in EPA Method 2 , using, 2 V = K 2g AP Ps (4) where, K = pitot tube flow coefficient g = gravitational constant AP = pressure drop data from pitot tube p = stack gas density. s Stack gas density...

Johnson, Randall Mark

2012-06-07

43

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

E-print Network

on the walls of the sampler in sign1ficant quantity. The preseparator removes those particles from gas stream and allows the centr1peter to operate in an eff1cient manner. 14 CHAPTER III EXPERIMENTAL APPARATUS Wind Tunnel All of the 1aboratory aerosol... 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...

Bertch, Russell William

2012-06-07

44

40 CFR 86.210-08 - Exhaust gas sampling system; Diesel-cycle vehicles not requiring particulate emissions measurements.  

Code of Federal Regulations, 2012 CFR

... false Exhaust gas sampling system; Diesel-cycle vehicles not requiring particulate...210-08 Exhaust gas sampling system; Diesel-cycle vehicles not requiring particulate...Otto-cycle vehicles), also apply to diesel vehicles that are not required to...

2012-07-01

45

Exposure assessment of particulates of diesel and natural gas fuelled buses in silico.  

PubMed

Lung deposition estimates of particulate emissions of diesel and natural gas (CNG) fuelled vehicles were studied by using in silico methodology. Particulate emissions and particulate number size distributions of two Euro 2 petroleum based diesel buses and one Euro 3 gas bus were measured. One of the petroleum based diesel buses used in the study was equipped with an oxidation catalyst on the vehicle (DI-OC) while the second had a partial-DPF catalyst (DI-pDPF). The third bus used was the gas bus with an oxidation catalyst on the vehicle (CNG-OC). The measurements were done using a transient chassis dynamometer test cycle (Braunschweig cycle) and an Electric Low Pressure Impactor (ELPI) with formed particulates in the size range of 7 nm to 10 microm. The total amounts of the emitted diesel particulates were 88-fold for DI-OC and 57-fold for DI-pDPF compared to the total amount of emitted CNG particulates. Estimates for the deposited particulates were computed with a lung deposition model ICRP 66 using in-house MATLAB scripts. The results were given as particulate numbers and percentages deposited in five different regions of the respiratory system. The percentages of particulates deposited in the respiratory system were 56% for DI-OC, 51% for DI-pDPF and 77% for CNG-OC of all the inhaled particulates. The result shows that under similar conditions the total lung dose of particulates originating from petroleum diesel fuelled engines DI-OC and DI-pDPF was more than 60-fold and 35-fold, respectively, compared to the lung dose of particulates originating from the CNG fuelled engine. The results also indicate that a majority (35-50%) of the inhaled particulates emitted from the tested petroleum diesel and CNG engines penetrate deep into the unciliated regions of the lung where gas-exchange occurs. PMID:19828175

Pietikäinen, Mari; Oravisjärvi, Kati; Rautio, Arja; Voutilainen, Arto; Ruuskanen, Juhani; Keiski, Riitta L

2009-12-15

46

Characteristics and photochemical potentials of volatile organics emission from stack exhaust gas of industrial processes  

SciTech Connect

The main objective of this project was to measure the main volatile organic compounds (VOCs) in stack gas from the downstream petrochemical plants. Six pollution sources of industrial processes, including Acrylonitrile-Butadiene-Styrene (ABS), Vinyl Chloride(VC), Polyvinyl Chloride (PVC), Acrylic Resin, para-Terephthalic Acid (PTA) and Polyurethane (PU) synthetic manufacturing processes, were measured by using USEPA Method 18. The concentration and emission rate database of twenty-seven VOCs has been established. Fifty-two selected stacks were sampled and analyzed for VOCs. Analysis of emission factors and characteristics of the twenty-seven VOCs in these stacks show that the emission characteristics are various among different industrial processes. The order of the single-stack VOCs average emission factor are ABS (1.109 lbs VOCs/ton-ABS; 22 stacks) {gt} Acrylic Resin (0.651 lbs VOCs/ton-acrylic resin; 7 stacks) {gt} PU Synthetic (0.606 lbs VOCs/ton-PU synthetic; 4 stacks) {gt} PTA (0.054 lbs VOCs/ton-PTA; 4 stacks) {gt} PVC (0.014 lbs VOCs/ton-PVC; 11 stacks) {gt} VC ({lt} 0.001; 4 stacks) manufacturing processes. The emission factors of VOC in AP-42 database for the processes of are 5 to 40 times higher than those of VOCs in this research. Because of the equipment of pollutant control setting up before the emitted exhaust gas, their average emission factors in these measured processes are almost lower than those of VOCs in AP-42 database. Compared with the characteristics of VOCs, there is little similarity in VOC characteristics for the stacks of six processes between the results from this research and the data from US EPA SPECIATE data system. Furthermore, according to maximum incremental reactivities (MIR) of VOCs probed into photochemical reaction potentials, the results show that those of PTA manufacturing process have an ozone formation potential of 2.33 g O{sub 3}/g VOCs, which is higher than other processes.

Hsu, Y.C.; Tsai, J.H.; Lin, T.C.; Cheng, C.C.; Huang, Y.H.

1999-07-01

47

KEY COMPARISON Final report on international comparison CCQM-K71: Measurement of stack gas  

Microsoft Academic Search

Industrial stack gas emission measurements are important for process control, control of air pollution, and for implementing legislation regarding carbon dioxide emission rights. Measurements are typically performed using a range of process analysers for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and miscellaneous hydrocarbons. The calibration of these analysers is often performed using a series

G. Nieuwenkamp; A. M. H. van der Veen; R. M. Wessel; Han Qiao; Sang-Hyub Oh; Byung-Moon Kim; Kwang-Sub Kim; Alejandro Pérez Castorena; Carlos Ramírez Nambo; Jorge Koelliker Delgado; Victor M. Serrano Caballero; Francisco Rangel Murillo; Manuel de Jesus Avila Salas; Florbela Dias; Gonçalo Baptista; L. A. Konopelko; Y. A. Kustikov; V. V. Pankratov; D. N. Selyukov; V. S. Balandovich; I. M. Vishnyakov; M. V. Pavlov; M. A. Maltsev; Angelique Botha; Miroslava Valkova; Viliam Stovcik; Stanislav Musil; M. J. T. Milton; I. J. Uprichard; G. M. Vargha; F. Guenther; L. Gameson; V. da Cunha

2010-01-01

48

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

49

Observation of exclusively ?-stacked heterodimer of indole and hexafluorobenzene in the gas phase  

NASA Astrophysics Data System (ADS)

In this study, the structure of the indole . . . hexafluorobenzene dimer has been investigated in the gas phase by using resonant two photon ionzation (R2PI) and IR-UV double resonance spectroscopy combined with quantum chemistry calculations. We have confirmed the presence of exclusively ?-stacked structure of the dimer from both experimental and theoretical IR spectra in the N-H stretching region. Observation of a single stable structure of the dimer has also been verified through 3D potential energy surface scan of the ?-stacked dimer by varying the parallel displacement of the hexafluorobenzene unit simultaneously along the major and minor axes of the indole moiety. ?-stacking interaction is present very often between the tryptophan and phenylalanine residues in proteins. But this interaction has not been observed earlier in the gas phase experiment by studying indole . . . benzene dimer because the N-H group of indole predominately directs towards the N-H . . . ? hydrogen bonded T-shaped structure. The chosen molecular systems in this study not only rule out the possibility of the formation of the N-H . . . ? bound T-shaped dimer but also enable the determination of the structure by probing the N-H group. The ?-stacked indole . . . hexafluorobenzene dimer has a unique structure where the center of the hexafluorobenznene ring is aligned with the center of the shared bond of the indole ring. Our work provides useful insight in designing unnatural proteins having strong ?-stacking interaction between the tryptophan and phenylalanine residues.

Kumar, Sumit; Das, Aloke

2013-09-01

50

FACTORS INFLUENCING THE DEPOSITION OF A COMPOUND THAT PARTITIONS BETWEEN GAS AND PARTICULATE PHASES  

EPA Science Inventory

How will atmospheric deposition behave for a compound when it reversibly sorbs between gas and atmospheric particulate phases? Two factors influence the answer. What physical mechanisms occur in the sorption process? What are the concentration and composition of atmospheric par...

51

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

52

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

53

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

54

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2013 CFR

40 Protection of Environment 28 2013-07-01 2013-07-01 false Standards to control particulate...the stack gas according to the formula: ER30SE99.027 Where: Pc is the corrected concentration of the pollutant in the stack...

2013-07-01

55

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

56

Direct analysis of diesel particulate-bound hydrocarbons by gas chromatography with solid sample injection  

SciTech Connect

Particulate-bound hydrocarbons emitted by diesel engines have been analysed using a rapid new technique. The method involves directly loading filter-borne particulate into a modified injection port of a gas chromatograph. Hydrocarbons are vaporized in this solid sample injection system and subsequently become adsorbed on to a chromatogaphy column. The merits of this procedure are demonstrated by comparing results with those obtained using conventional gas chromatography (with liquid injection) and thermogravimetry. The contribution of unburned engine oil to diesel particulate emissions has been investigated using the new method. For a DI truck diesel engine operated over the U.S. Federal Heavy Duty Transient Cycle it is shown that 40% of the particulate appears to be derived from unburned oil. For a comparable IDI truck diesel engine this value was 28%.

Cuthbertson, R.D.; Shore, P.R.; Sundstrom, L.; Heden, P.O.

1987-01-01

57

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

58

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...

59

MICROCOMPUTER PROGRAMS FOR PARTICULATE CONTROL: SECTION FAILURE; BAGHOUSE; PLUME OPACITY PREDICTION; AND IN-STACK OPACITY CALCULATOR  

EPA Science Inventory

IBM-PC usable versions of several computer models useful in particulate control are provided. The models were originally written for the TRS-80 Model I-III series of microcomputers and have been translated to run on the IBM-PC. The documentation for the TRS-80 versions applies to...

60

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

61

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

62

Compact hybrid particulate collector (COHPAC)  

SciTech Connect

This patent describes a method for retrofit filtering of particulates in a flue gas from a combustion source having an existing conventional electrostatic precipitator connected thereto and a smoke stack connected to the precipitator. It comprises: removing at least one discharge electrode and collecting electrode from within the housing of the electrostatic precipitator; attaching a tubesheet within the housing; supporting a compact baghouse filter within the separate filter section by the tubesheet; whereby the remaining discharge electrodes and corresponding collecting electrodes in the electrostatis precipitator serve to remove a majority of particulates form the flue gas and impart a residual charge on remaining particulates discharged to the separate filter section, and the remaining particulates are collected by the baghouse filter before the residual electric charge substantially dissipates.

Chang, R.

1992-10-27

63

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

64

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

65

Students' Conceptual Representations of Gas Volume in Relation to Particulate Model of Matter.  

ERIC Educational Resources Information Center

Most high school chemistry curricula contain a unit on gas volume and a unit on the particulate nature of matter. The existence and persistence of adolescent preconceptions about the material nature of gases is an important factor to be considered in the teaching of principles or theories related to gases. The purpose of the study reported in this…

Hwang, Bao-tyan

66

KEY COMPARISON Final report on international comparison CCQM-K71: Measurement of stack gas  

NASA Astrophysics Data System (ADS)

Industrial stack gas emission measurements are important for process control, control of air pollution, and for implementing legislation regarding carbon dioxide emission rights. Measurements are typically performed using a range of process analysers for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and miscellaneous hydrocarbons. The calibration of these analysers is often performed using a series of binary mixtures of each component in nitrogen. For reasons of efficiency as well as a better match with true stack gas, the use of multi-component mixtures for this purpose would be preferred. The aim of this key comparison is to evaluate the measurement capabilities of national metrology institutes for carbon monoxide, carbon dioxide, nitrogen monoxide, sulphur dioxide and propane in nitrogen. Ten laboratories participated in the key comparison and one in the associated study. The key comparison reference value is based on the gravimetric preparation data. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Nieuwenkamp, G.; van der Veen, A. M. H.; Wessel, R. M.; Qiao, Han; Oh, Sang-Hyub; Kim, Byung-Moon; Kim, Kwang-Sub; Pérez Castorena, Alejandro; Ramírez Nambo, Carlos; Koelliker Delgado, Jorge; Serrano Caballero, Victor M.; Rangel Murillo, Francisco; Avila Salas, Manuel de Jesus; Dias, Florbela; Baptista, Gonçalo; Konopelko, L. A.; Kustikov, Y. A.; Pankratov, V. V.; Selyukov, D. N.; Balandovich, V. S.; Vishnyakov, I. M.; Pavlov, M. V.; Maltsev, M. A.; Botha, Angelique; Valkova, Miroslava; Stovcik, Viliam; Musil, Stanislav; Milton, M. J. T.; Uprichard, I. J.; Vargha, G. M.; Guenther, F.; Gameson, L.; da Cunha, V.

2010-01-01

67

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

68

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

69

Networked solid oxide fuel cell stacks combined with a gas turbine cycle  

Microsoft Academic Search

An improved design of fuel cells stacks arrangement has been suggested before for MCFC where reactant streams are ducted such that they are fed and recycled among multiple MCFC stacks in series. By networking fuel cell stacks, increased efficiency, improved thermal balance, and higher total reactant utilisation can be achieved. In this study, a combination of networked solid oxide fuel

Azra Selimovic; Jens Palsson

2002-01-01

70

Partitioning of organic aerosol components between gas phase and particulate phase  

NASA Astrophysics Data System (ADS)

To understand the role of organics in aerosols both the particulate composition and the gas/vapor phase composition must determined simultaneously. Ammonium sulfates and dicarboxylic acids are major components of continental, tropospheric aerosols. We performed two experiments in which we studied the partitioning of organic aerosol components between the gas and the particulate phase. As model systems we chose (NH4HSO_4 + glutaric acid) aerosol and ((NH4)HSO_4 + methyl glyoxal) aerosol (an oxidation product of isoprene). The experiment were performed in the large Aerosol Chamber at the FZ-Jülich at room temperature. The relative humidity was constantly increased in the course of the experiment (40 -> 90% r.h., 60 -> 90% r.h.).\

Folkers, M.; Mentel, T. F.; Henk, H.; Tillmann, R.; Wahner, A.; Otjes, R. P.; Blom, M. J.; ten Brink, H. M.

2003-12-01

71

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

72

Gas Chromatography/Matrix Isolation-Infrared Spectrometry for the Identification of Polycyclic Aromatic Hydrocarbons in Urban Air Particulate Matter.  

National Technical Information Service (NTIS)

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

J. W. Childers, N. K. Wilson, R. K. Barbour

1989-01-01

73

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...

74

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

75

The Lockman Hole project: gas and galaxy properties from a stacking experiment  

NASA Astrophysics Data System (ADS)

We perform an H I stacking analysis to study the relation between H I content and optical/radio/IR properties of galaxies located in the Lockman Hole area. In the redshift range covered by the observations (up to z = 0.09), we use the SDSS to separate galaxies with different optical characteristics, and we exploit the deep L-band radio continuum image (with noise 11 ?Jy beam-1) to identify galaxies with radio continuum emission. Infrared properties are extracted from the Spitzer catalog. We detect H I in blue galaxies, but H I is also detected in the group of red galaxies - albeit with smaller amounts than for the blue sample. We identify a group of optically inactive galaxies with early-type morphology that does not reveal any H I and ionized gas. These inactive galaxies likely represent the genuine red and dead galaxies depleted of all gas. Unlike inactive galaxies, H I is detected in red LINER-like objects. Galaxies with radio continuum counterparts mostly belong to the sub-mJy population, whose objects are thought to be a mixture of star-forming galaxies and low-power AGNs. After using several AGN diagnostics, we conclude that the radio emission in the majority of our sub-mJy radio sources stems from star formation. LINERs appear to separate into two groups based on IR properties and H I content. LINERs with a 24 ?m detection show relatively large amounts of H I and are also often detected in radio continuum as a result of ongoing star formation. The LINER galaxies which are not detected at 24 ?m are more like the optically inactive galaxies by being depleted of H I gas and having no sign of star formation. Radio LINERs in the latter group are the best candidates for hosting low-luminosity radio AGN.

Geréb, K.; Morganti, R.; Oosterloo, T. A.; Guglielmino, G.; Prandoni, I.

2013-10-01

76

Gas and fine particulate phase N-nitroso and nitrite organic compounds in the atmosphere  

SciTech Connect

Photochemistry between gas phase organic compounds, NO{sub x} and ozone is expected to result in the formation of nitrogen containing compounds of toxicological importance. Classes of potentially toxic organic compounds which may form include nitro-, N-nitroso- and nitrite-substituted compounds. The compounds are expected to be labile, semi-volatile organic compounds in equilibrium between the gas and particulate phases in the atmosphere. The phase distribution of these potentially toxic semi-volatile organic compounds can be determined using diffusion denuder samplers. The total concentration of N-nitroso compounds in a collected sample is determined using N-nitroso specific denitrosation reactions followed by detection of the NO produced with a chemiluminescence detector. Denitrosation chemistry can also be used to determine nitrite compounds. Differentiation between total N-nitroso- and nitrite-containing compounds is accomplished using sulfamic acid as a nitrite specific reagent. These analytical techniques for the sampling and determination of total N-nitroso and nitrite material have been used for the quantification of these classes of compounds in both fine particles and the gas phase in samples collected in Provo, Utah. The results indicate that the majority of the N-nitroso and nitrite organic compounds present in fine particulate matter in the urban area studied are semi-volatile organic compounds which are lost from particles during sampling. Furthermore, the concentrations of these fine particulate compounds are comparable to the concentrations of gas phase N-nitroso and nitrite organic species. 35 refs., 5 figs., 2 tabs.

Ding, Yiming; Cui, Wenxuan; Lee, M.L.; Eatough, D.J. [Brigham Young Univ., Provo, UT (United States)

1996-12-31

77

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

78

Identification of indicator congeners and evaluation of emission pattern of polychlorinated naphthalenes in industrial stack gas emissions by statistical analyses.  

PubMed

Identifying marker congeners of unintentionally produced polychlorinated naphthalenes (PCNs) from industrial thermal sources might be useful for predicting total PCN (?2-8PCN) emissions by the determination of only indicator congeners. In this study, potential indicator congeners were identified based on the PCN data in 122 stack gas samples from over 60 plants involved in more than ten industrial thermal sources reported in our previous case studies. Linear regression analyses identified that the concentrations of CN27/30, CN52/60, and CN66/67 correlated significantly with ?2-8PCN (R(2)=0.77, 0.80, and 0.58, respectively; n=122, p<0.05), which might be good candidates for indicator congeners. Equations describing relationships between indicators and ?2-8PCN were established. The linear regression analyses involving 122 samples showed that the relationships between the indicator congeners and ?2-8PCN were not significantly affected by factors such as industry types, raw materials used, or operating conditions. Hierarchical cluster analysis and similarity calculations for the 122 stack gas samples were adopted to group those samples and evaluating their similarity and difference based on the PCN homolog distributions from different industrial thermal sources. Generally, the fractions of less chlorinated homologs comprised of di-, tri-, and tetra-homologs were much higher than that of more chlorinated homologs for up to 111 stack gas samples contained in group 1 and 2, which indicating the dominance of lower chlorinated homologs in stack gas from industrial thermal sources. PMID:25218874

Liu, Guorui; Cai, Zongwei; Zheng, Minghui; Jiang, Xiaoxu; Nie, Zhiqiang; Wang, Mei

2015-01-01

79

An automatic isokinetic sampler for particulate emissions from aircraft gas turbine engines. Final report Feb 75-Jun 78  

SciTech Connect

An automated isokinetic sampler for evaluating particulate emissions from aircraft gas turbine engines was designed, constructed and tested. The sampler is capable of collecting the particulate mass emitted by an aircraft gas turbine at the exit plane (non-afterburner operation) for gravimetric measurements and permits simultaneous on-line particle size distribution measurements to be performed. The particulate is collected on a fiber glass filter for gravimetric measurement. The size distribution is determined by conditioning the gas turbine exhaust gases and passing them through a mobility particulate size distribution analyzer. The sampler has two-axis traverse capability and a maximum sampling capability of 226 1/min (8 scfm). Test data are automatically recorded. Control of the sampler is by means of 12-bit microprocessor. Preliminary tests were performed at the Naval Air Rework Facility, Alameda, California, at various construction stages of the sampler to evaluate its performance and to measure the effects of fuel additives on particulate emissions on a TF41 gas turbine engine.

Dehne, H.

1980-01-01

80

The development and presentation of a short course on stack sampling  

E-print Network

of particulate being emitted through the stack. Not only must the sample be collected at each traverse point, but a method known as isokinetic sampling must be employed in order to obtain a representative sample. Isokinetic sampling involves collection... is too high (over-isokinetic sampling), 21 the concentration of particles collected will 'be lower than actually exists within the stack. Conversely, if the velocity cf the gas entering the nozzle i" too low {under-isokinetic sampling...

Bentzen, Gordon Warren

2012-06-07

81

Evaluation of a Combined Cyclone and Gas Filtration System for Particulate Removal in the Gasification Process  

SciTech Connect

The Wabash gasification facility, owned and operated by sgSolutions LLC, is one of the largest single train solid fuel gasification facilities in the world capable of transforming 2,000 tons per day of petroleum coke or 2,600 tons per day of bituminous coal into synthetic gas for electrical power generation. The Wabash plant utilizes Phillips66 proprietary E-Gas (TM) Gasification Process to convert solid fuels such as petroleum coke or coal into synthetic gas that is fed to a combined cycle combustion turbine power generation facility. During plant startup in 1995, reliability issues were realized in the gas filtration portion of the gasification process. To address these issues, a slipstream test unit was constructed at the Wabash facility to test various filter designs, materials and process conditions for potential reliability improvement. The char filtration slipstream unit provided a way of testing new materials, maintenance procedures, and process changes without the risk of stopping commercial production in the facility. It also greatly reduced maintenance expenditures associated with full scale testing in the commercial plant. This char filtration slipstream unit was installed with assistance from the United States Department of Energy (built under DOE Contract No. DE-FC26-97FT34158) and began initial testing in November of 1997. It has proven to be extremely beneficial in the advancement of the E-Gas (TM) char removal technology by accurately predicting filter behavior and potential failure mechanisms that would occur in the commercial process. After completing four (4) years of testing various filter types and configurations on numerous gasification feed stocks, a decision was made to investigate the economic and reliability effects of using a particulate removal gas cyclone upstream of the current gas filtration unit. A paper study had indicated that there was a real potential to lower both installed capital and operating costs by implementing a char cyclonefiltration hybrid unit in the E-Gas (TM) gasification process. These reductions would help to keep the E-Gas (TM) technology competitive among other coal-fired power generation technologies. The Wabash combined cyclone and gas filtration slipstream test program was developed to provide design information, equipment specification and process control parameters of a hybrid cyclone and candle filter particulate removal system in the E-Gas (TM) gasification process that would provide the optimum performance and reliability for future commercial use. The test program objectives were as follows: 1. Evaluate the use of various cyclone materials of construction; 2. Establish the optimal cyclone efficiency that provides stable long term gas filter operation; 3. Determine the particle size distribution of the char separated by both the cyclone and candle filters. This will provide insight into cyclone efficiency and potential future plant design; 4. Determine the optimum filter media size requirements for the cyclone-filtration hybrid unit; 5. Determine the appropriate char transfer rates for both the cyclone and filtration portions of the hybrid unit; 6. Develop operating procedures for the cyclone-filtration hybrid unit; and, 7. Compare the installed capital cost of a scaled-up commercial cyclone-filtration hybrid unit to the current gas filtration design without a cyclone unit, such as currently exists at the Wabash facility.

Rizzo, Jeffrey J. [Phillips66 Company, West Terre Haute, IN (United States)

2010-04-30

82

Characterization of particulate matter emissions from a current technology natural gas engine.  

PubMed

Experiments were conducted to characterize the particulate matter (PM)-size distribution, number concentration, and chemical composition emitted from transit buses powered by a USEPA 2010 compliant, stoichiometric heavy-duty natural gas engine equipped with a three-way catalyst (TWC). Results of the particle-size distribution showed a predominant nucleation mode centered close to 10 nm. PM mass in the size range of 6.04 to 25.5 nm correlated strongly with mass of lubrication-oil-derived elemental species detected in the gravimetric PM sample. Results from oil analysis indicated an elemental composition that was similar to that detected in the PM samples. The source of elemental species in the oil sample can be attributed to additives and engine wear. Chemical speciation of particulate matter (PM) showed that lubrication-oil-based additives and wear metals were a major fraction of the PM mass emitted from the buses. The results of the study indicate the possible existence of nanoparticles below 25 nm formed as a result of lubrication oil passage through the combustion chamber. Furthermore, the results of oxidative stress (OS) analysis on the PM samples indicated strong correlations with both the PM mass calculated in the nanoparticle-size bin and the mass of elemental species that can be linked to lubrication oil as the source. PMID:24960475

Thiruvengadam, Arvind; Besch, Marc C; Yoon, Seungju; Collins, John; Kappanna, Hemanth; Carder, Daniel K; Ayala, Alberto; Herner, Jorn; Gautam, Mridul

2014-07-15

83

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

PubMed

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 emissionfactors for flares were reviewed and found to be questionably accurate, or based on measurements not directly relevant to open-atmosphere flares. In addition, most previous studies of soot emissions from turbulent diffusion flames considered alkene or alkyne based gaseous fuels, and few considered mixed fuels in detail and/or lower sooting propensity fuels such as methane, which is the predominant constituent of gas flared in the upstream oil and gas industry. Quantitative emission measurements were performed on laboratory-scale flares for a range of burner diameters, exit velocities, and fuel compositions. Drawing from established standards, a sampling protocol was developed that employed both gravimetric analysis of filter samples and real-time measurements of soot volume fraction using a laser-induced incandescence (LII) system. For the full range of conditions tested (burner inner diameter [ID] of 12.7-76.2 mm, exit velocity 0.1-2.2 m/sec, 4- and 6-component methane-based fuel mixtures representative of associated gas in the upstream oil industry), measured soot emission factors were less than 0.84 kg soot/10(3) m3 fuel. A simple empirical relationship is presented to estimate the PM emission factor as a function of the fuel heating value for a range of conditions, which, although still limited, is an improvement over currently available emission factors. PMID:22482289

McEwen, James D N; Johnson, Matthew R

2012-03-01

84

Titanium-installation and operation of titanium linings in flue gas desulfurization ductwork and stacks  

SciTech Connect

For over ten years, titanium has provided generally excellent service in the harsh environment of FGD scrubbers. Based on its superior corrosion resistance and cost effectiveness, titanium is most often selected for lining of outlet ducts or stacks. This paper will review the different lining approaches and the service experience of the metal.

Peacock, D.K. [TIMET, Essex (United Kingdom); Grauman, J.S. [TIMET-Henderson Technical Lab., Henderson, NV (United States)

1995-12-01

85

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

86

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

87

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

88

Composition, Toxicity, and Mutagenicity of Particulate and Semivolatile Emissions from Heavy-Duty Compressed Natural Gas-Powered Vehicles  

Microsoft Academic Search

Particulate matter (PM) and vapor-phase semivolatile organic compounds (SVOC) were collected from three buses fueled by com- pressed natural gas. The bus engines included a well-functioning, conventional engine; a ''high emitter'' engine; and a new technol- ogy engine with an oxidation catalyst. Chemical analysis of the emissions showed differences among these samples, with the high emitter sample containing markers of

JeanClare Seagrave; Andrew Gigliotti; Jacob D. McDonald; Steven K. Seilkop; Kevin A. Whitney; Barbara Zielinska; Joe L. Mauderly

2005-01-01

89

Concept Learning versus Problem Solving: Evaluating a Threat to the Validity of a Particulate Gas Law Question  

ERIC Educational Resources Information Center

Three different samples of students were asked to answer five multiple-choice questions concerning the properties of a sample of helium gas (particle speed, state of matter, sample volume, sample pressure, and particle distribution), including a particulate question first used by Nurrenbern and Pickering (particle distribution). In the first…

Sanger, Michael J.; Vaughn, C. Kevin; Binkley, David A.

2013-01-01

90

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...

91

Gas?particulate phase distribution and decay rates of constituents in ageing environmental tobacco smoke  

Microsoft Academic Search

Phase distribution and decay rates of ETS components were determined for an experimental room. Solanesol and protonated nicotine behave like particulate matter (UV?PM). Free nicotine evaporates from the particulate phase during the 5 minute sampling time and decays rapidly from the gaseous phase. Neophytadiene leaves the particulate phase faster than predicted by deposition. Limonene, 3?ethenylpyridine, and naphthalene are present only

Georg B. Neurath; Sylvia Petersen; Michael Dunger; Dorothea Orth; F. Gerhard Pein

1991-01-01

92

On-line analysis of the size distribution of fine and ultrafine aerosol particles in flue and stack gas of a municipal waste incineration plant: effects of dynamic process control measures and emission reduction devices.  

PubMed

The size distribution of particles in the waste gas of a municipal waste incineration plant (23 MW) was measured on-line at two sampling points in the flue-gas duct (700 and 300 degrees C) as well as in the stack gas (80 degrees C). The measurements were performed during both stable combustion conditions and transient operating conditions. The particle measurements were carried out by a mobile system consisting of a home-designed sampling system with dilution device and a scanning mobility particle sizer (SMPS) for the particle size range 17-600 nm as well as an aerodynamic particle sizer (APS) for the size range 500 nm-30 microm. The APS and SMPS data were combined using a special method and a home written software tool. The maximum of the particle-size distribution in the flue gas of the incinerator shifts from about 90 nm at the 700 degrees C sampling point to about 140 nm at the 300 degrees C point, showing the particle growth by coagulation processes and condensation of inorganic and organic gaseous species with decreasing temperature. This finding is consistent with the measured concentration profiles of gaseous organic chemical species in the flue gas. While at flue-gas temperatures of 600-800 degrees C a rich pattern of polycyclic aromatic hydrocarbon species (PAH) is observable, the PAH concentrations are considerably reduced further downstream of the flue-gas channel, where the temperature drops below 500 degrees C. Condensation and reactive bonding of gaseous chemicals onto particulate matter is, among other reasons, responsible for the depletion of gas-phase species. Process control measures, such as firing the backup burners or cleaning of the grate with pressurized air, can cause dynamic changes of the particle-size distribution. Furthermore the flue-gas cleaning measures have great impact onto both the particle concentration and the size distribution. For this reason the impact of one particular emission reduction device, the wet electrostatic dust precipitator (wet-ESP), is evaluated. The wet-ESP reduces considerably the particle concentration over the whole size range. Behind the flue-gas processing units a broad maximum in the particle-size distribution occurs at about 70 nm, but no pronounced particle-size distribution could be observed. The particle concentration level atthis maximum is about 3 magnitudes lower than in the raw flue gas. However, intermittent periods lasting for several minutes of high emissions of ultrafine particles with d < 40 nm were observed. These particles are most likely formed by nucleation processes behind the wet-ESP from gas-phase constituents of the stack gas. PMID:14594389

Maguhn, Jürgen; Karg, Erwin; Kettrup, Antonius; Zimmermann, Ralf

2003-10-15

93

METHODS AND RESULTS OF RECONSTRUCTION OF NOBLE GAS RELEASES FROM THE STACKS OF THE MAYAK PA GRAPHITE REACTORS OVER THE WHOLE PERIOD OF THEIR OPERATION  

SciTech Connect

Brief analysis of design features and operational modes of Mayak PA industrial graphite-uranium reactors (PUGRs) is given. The above mentioned Mayak PA PUGRs determined the rates of releases of radioactive noble gases (RNG) from activation (41Ar) and fission (isotopes of Krypton and Xenon) through the vent stack of the reactor. Information is given on methods and results of experimental determination of RNG atmospheric releases for the period starting from 1965 till PUGRs decommissioning in 1987-1990. A calculation method for reconstruction of radioactive noble gas releases is proposed and justified. The results of reconstruction are given. It is shown that maximum rates of RNG releases from PUGRs high stacks were observed in the 1950s, when ordinary atmospheric air was used as a cover gas for the reactor graphite stacks and gas purification systems (flow-type gas holders) had not been installed yet.

Glagolenko, Y. V.; Drozhko, Evgeniy G.; Mokrov, Y.; Pyatin, N. P.; Rovny, Sergey I.; Anspaugh, L. R.; Napier, Bruce A.

2008-06-01

94

Gas and Particulate Aircraft Emissions Measurements: Impacts on local air quality.  

NASA Astrophysics Data System (ADS)

Air travel and freight shipping by air are becoming increasingly important and are expected to continue to expand. The resulting increases in the local concentrations of pollutants, including particulate matter (PM), volatile organic compounds (VOCs), and nitrogen oxides (NOX), can have negative impacts on regional air quality, human health and can impact climate change. In order to construct valid emission inventories, accurate measurements of aircraft emissions are needed. These measurements must be done both at the engine exit plane (certification) and downwind following the rapid cooling, dilution and initial atmospheric processing of the exhaust plume. We present here results from multiple field experiments which include the Experiment to Characterize Volatile Aerosol and Trace Species Emissions (EXCAVATE) and the four Aircraft Particle Emissions eXperiments (APEX- 1/Atlanta/2/3) which characterized gas and particle emissions from both stationary or in-use aircraft. Emission indices (EIs) for NOx and VOCs and for particle number concentration, refractory PM (black carbon soot) and volatile PM (primarily sulfate and organic) particles are reported. Measurements were made at the engine exit plane and at several downstream locations (10 and 30 meters) for a number of different engine types and engine thrust settings. A significant fraction of organic particle mass is composed of low volatility oil-related compounds and is not combustion related, potentially emitted by vents or heated surfaces within aircraft engines. Advected plumes measurements from in-use aircraft show that the practice of reduced thrust take-offs has a significant effect on total NOx and soot emitted in the vicinity of the airport. The measurements reported here represent a first observation of this effect and new insights have been gained with respect to the chemical processing of gases and particulates important to the urban airshed.

Jayne, J. T.; Onasch, T.; Northway, M.; Canagaratna, M.; Worsnop, D.; Timko, M.; Wood, E.; Miake-Lye, R.; Herndon, S.; Knighton, B.; Whitefield, P.; Hagen, D.; Lobo, P.; Anderson, B.

2007-12-01

95

Operating characteristics of a 5 kW class anode-supported planar SOFC stack for a fuel cell\\/gas turbine hybrid system  

Microsoft Academic Search

We designed and constructed a pressurized 5kW anode-supported planar solid oxide fuel cell (SOFC) power generation system with a pre-reformer for a fuel cell\\/gas turbine hybrid system. The 5kW class SOFC stack, which was made by Forschungszentrum Jülich (FZJ) in Germany, was assembled and installed at KIER. We also investigated the stack's typical operating characteristics, particularly with respect to the

Tak-Hyoung Lim; Rak-Hyun Song; Dong-Ryul Shin; Jung-Il Yang; Heon Jung; I. C. Vinke; Soo-Seok Yang

2008-01-01

96

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

97

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

98

Particulate Matter Removal from a Gas Stream using High?Voltage Discharge Plasma  

Microsoft Academic Search

This investigation examines the use of a high?voltage discharge plasma technology to remove particulate matter from an air stream. Concentrations of the particulate matter were measured at the inlet and the outlet of the discharge plasma with the help of an optical particle counter to determine the particle removal efficiency. The experimental results indicate that the particle removal efficiency of

2008-01-01

99

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...

100

40 CFR 60.1290 - How are the stack test data used?  

Code of Federal Regulations, 2010 CFR

...June 6, 2001 Stack Testing § 60.1290 How are the stack test data used? You must use results of stack tests for dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive ash to demonstrate...

2010-07-01

101

40 CFR 62.15235 - How are the stack test data used?  

Code of Federal Regulations, 2010 CFR

...August 30, 1999 Stack Testing § 62.15235 How are the stack test data used? You must use results of stack tests for dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive ash to demonstrate...

2010-07-01

102

Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform  

NASA Astrophysics Data System (ADS)

The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity ratios showed distinct differences between the closed CANDU primary coolant system and radiopharmaceutical production releases. According to the concept proposed by Kalinowski and Pistner (2006), the relationship between different isotopic activity ratios based on three or four radioxenon isotopes was plotted in a log-log diagram for source characterisation (civil vs. nuclear test). The multiple isotopic activity ratios were distributed in three distinct areas: HC atmospheric monitoring ratios extended to far left; the CANDU primary coolant system ratios lay in the middle; and 99Mo stack monitoring ratios for ANSTO and CRL were located on the right. The closed CANDU primary coolant has the lowest logarithmic mean ratio that represents the nuclear power reactor operation. The HC atmospheric monitoring exhibited a broad range of ratios spreading over several orders of magnitude. In contrast, the ANSTO and CRL stack emissions showed the smallest range of ratios but the results indicate at least two processes involved in the 99Mo productions. Overall, most measurements were found to be shifted towards the reactor domain. The hypothesis is that this is due to an accumulation of the isotope 131mXe in the stack or atmospheric background as it has the longest half-life and extra 131mXe emissions from the decay of 131I. The contribution of older 131mXe to a fresh release shifts the ratio of 133mXe/131mXe to the left. It was also very interesting to note that there were some situations where isotopic ratios from 99Mo production emissions fell within the nuclear test domain. This is due to operational variability, such as shorter target irradiation times. Martin B. Kalinowski and Christoph Pistner, (2006), Isotopic signature of atmospheric xenon released from light water reactors, Journal of Environmental Radioactivity, 88, 215-235.

Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

2013-04-01

103

Simplified, solid-state, wide-range, stack-gas monitor for nuclear power plants  

Microsoft Academic Search

Government regulations require that radioactive effluent from nuclear power plants be measured and reported and that effluent reporting be based on laboratory analyses. Continuous monitoring during a postulated design-basis accident is also required. Wide-range gas monitors for satisfying regulatory requirements for post-accident radiation monitoring typically have been very complex, and costly to operate and maintain. This paper describes recently developed

Clinton L. Lingren

2000-01-01

104

Simplified, solid-state, wide-range, stack-gas monitor for nuclear power plants  

Microsoft Academic Search

Government regulations require the measuring and reporting of radioactive effluent from nuclear power plants. In addition to effluent reporting based on laboratory analyses, continuous monitoring during a postulated design-basis accident is also required. Wide-range gas monitors for satisfying regulatory requirements for post-accident radiation monitoring typically have been very complex, and costly to operate and maintain. This paper describes recently developed

Clinton L. Lingren

1998-01-01

105

Flue Gas Conditioning to Reduce Particulate Emissions in Industrial Coal-Fired Boilers  

E-print Network

distribution and absorption on the fly ash before it reaches the ESP. The result can be undesirable particulate and S03 (blue haze) emissions--possibly leading to acid fallout. Ammonia has also been used to try to condition fly ash to improve collection... distribution and absorption on the fly ash before it reaches the ESP. The result can be undesirable particulate and S03 (blue haze) emissions--possibly leading to acid fallout. Ammonia has also been used to try to condition fly ash to improve collection...

Miller, B.; Keon, E.

1980-01-01

106

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

107

Capabilities at the Diesel Engine Test Facility for Measuring Gas-Phase and Particulate Emissions  

Microsoft Academic Search

Description of the test facility The combustion research laboratory has a variety of capabilities for measuring and characterizing emissions produced from the test diesel engine. For particulate matter, the combustion laboratory has a TSI Scanning Mobility Particle Sizer (SMPS) that measures particle size distributions from 7 nm to 300 nm, and a Lasair 310 optical particle counter (OPC) that measures

Kerry Kelly; Guojin Wang; A. F. Sarofim; H. L. C. Meuzelaar

108

The development of a draft protocol for the sampling and analysis of particulate and organic contaminants in the gas from small biomass gasifiers  

Microsoft Academic Search

A number of companies have developed, and are developing, power generation technology based on the gasification of biomass. These technologies have three process steps: the gasification reactor, cleaning of the producer gas, and an engine generator set. The producer gas from all gasification reactors contains particulates and organic contaminants (tars) which, if not removed, would damage the engine or incur

Nick Abatzoglou; Nick Barker; Philipp Hasler; Harrie Knoef

2000-01-01

109

Study Stack  

NSDL National Science Digital Library

Developed by John Weidner, the Study Stack concept basically assists individuals to memorize information about various subjects, including geography, history, math, languages, and science. Users of the site can select one of the existing stacks, which consists of virtual study cards allowing individuals to learn at their own pace until they are satisfied with their progress. What is also particularly novel about this learning tool is that data entered for customized study stacks can be automatically displayed as a matching game, a word search puzzle, or a hangman game. So far, the site contains dozens of study stacks for each subject, with the areas dedicated to math and science containing quite a number of rather helpful stacks. With its wide range of applications, this site will be very helpful to students at different age levels and teachers who may be seeking to develop a new study tool for any number of topics or themes within a subject area.

Weidner, John

110

Stacks of Light  

NASA Technical Reports Server (NTRS)

These two images show 'stacked' Chandra images for two different classes of distant, massive galaxy detected with Spitzer. Image stacking is a procedure used to detect emission from objects that is too faint to be detected in single images. To enhance the signal, images of these faint objects are stacked on top of one another.

In both images, low-energy X-rays are shown in orange and high-energy X-rays in blue, and the stacked object is in the center of the image (the other sources beyond the center of the image are X-ray sources that were directly detected and are not part of the source stacking). On the left is a stacked Chandra image of the 'normal' galaxies seen with Spitzer. The infrared emission for these young, massive galaxies is consistent with expectations for star formation. The Chandra image shows mainly low-energy X-ray emission at the center as expected. On the right, is a stacked Chandra image for galaxies with infrared emission exceeding the levels likely to be caused by star formation. These galaxies contain active galactic nuclei, or quasars, in their centers. These are luminous objects powered by the rapid growth of supermassive black holes. The obscured quasars show much higher levels of high-energy X-ray emission because the less energetic X-rays are mostly absorbed by gas.

2007-01-01

111

Gas-Phase Ozone Oxidation of Monoterpenes: Gaseous and Particulate Products  

Microsoft Academic Search

Atmospheric oxidation of monoterpenes contributes to formation of tropospheric ozone and secondary organic aerosol, but their products are poorly characterized. In this work, we report a series of outdoor smog chamber experiments to investigate both gaseous and particulate products in the ozone oxidation of four monoterpenes: a-pinene, ß-pinene, ?3-carene, and sabinene. More than ten oxygenated products are detected and identified

Jianzhen Yu; David R. Cocker; Robert J. Griffin; Richard C. Flagan; John H. Seinfeld

1999-01-01

112

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

113

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

114

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Gas meter or flow instrumentation calibration...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND... § 92.117 Gas meter or flow instrumentation...

2013-07-01

115

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

...2013-07-01 true Gas meter or flow instrumentation calibration...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND... § 92.117 Gas meter or flow instrumentation...

2014-07-01

116

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Gas meter or flow instrumentation calibration...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND... § 92.117 Gas meter or flow instrumentation...

2012-07-01

117

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Gas meter or flow instrumentation calibration...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND... § 92.117 Gas meter or flow instrumentation...

2011-07-01

118

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Gas meter or flow instrumentation calibration...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND... § 92.117 Gas meter or flow instrumentation...

2010-07-01

119

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

120

Simultaneous particulates, NO sub x , SO sub x removal from flue gas by all solid-state electrochemical technology  

SciTech Connect

The process control SO{sub x}, NO{sub x}, and particulate emission from coal combustion flue gases. It is based on a solid-state, electrochemical reactor which converts NO{sub x} and SO{sub 2} to nitrogen, sulfur, and oxygen. Sulfur is condensed downstream at a lower temperature. Particulates are removed with a filter or electrostatic precipitator. The process utilizes no other material input (flue gas is the only fluid), has no moving parts, and produces no sludge(s). The reactor consists of an electrochemical cell where the electrolyte is a solid oxygen ion conducting ceramic such as stabilized ceria or zirconia and the electrodes are electronically conductive material(s). Porous metal such as silver or gold were used as electrodes in the experimental work. Acceptable reduction rates and electric power requirements for sulfur dioxide and nitrogen oxide removal were obtained in up to 1% oxygen with ruthenium and strontium ruthenate electrocatalysts. Electrocatalytic improvements are needed for higher oxygen concentrations, with the NO reduction rates and efficiencies being most sensitive to oxygen concentration. The best electrocatalysts were ruthenium and the perovskite strontium ruthenate. 37 refs., 23 figs., 26 tabs.

Cook, W.J.; Cornell, L.P.; Keyvani, M.; Neyman, M. (Helipump Corp., Cleveland, OH (USA)); Helfritch, D.J. (Research-Cottrell, Inc., Somerville, NJ (USA). Environmental Services and Technologies Div.)

1990-04-17

121

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

122

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

123

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...

124

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...

125

Gas and Particulate Products Distribution from the Photooxidation of ?-Humulene in the Presence of NO x , Natural Atmospheric Air and Sunlight  

Microsoft Academic Search

The photooxidation of a-humulene in the presence of NOx, natural sunlight, and rural background air was investigated using a combination of gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). Identification and quantification of gas and particulate reaction products were reported over the course of the reaction. The daytime photooxidation was carried out in a large outdoor smog chamber

M. Jaoui; R. M. Kamens

2003-01-01

126

40 CFR 62.15230 - What types of stack tests must I conduct?  

Code of Federal Regulations, 2010 CFR

...15230 What types of stack tests must I conduct? Conduct initial and annual stack tests to measure the emission levels of dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive...

2010-07-01

127

40 CFR 60.1285 - What types of stack tests must I conduct?  

Code of Federal Regulations, 2010 CFR

...1285 What types of stack tests must I conduct? Conduct initial and annual stack tests to measure the emission levels of dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive...

2010-07-01

128

40 CFR 60.1775 - What types of stack tests must I conduct?  

Code of Federal Regulations, 2010 CFR

...1775 What types of stack tests must I conduct? Conduct initial and annual stack tests to measure the emission levels of dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive...

2010-07-01

129

Department of Engineering Design Spring 2012 Good Stack, Bad Stack, Red Stack, Blue Stack-Stack Quality Detection Device  

E-print Network

PENNSTATE Department of Engineering Design Spring 2012 Good Stack, Bad Stack, Red Stack, Blue Stack of the project is to develop an innovative solution for detecting bad paper stacks; the device must be 95

Demirel, Melik C.

130

Evaluation of methods for measuring particulate matter emissions from gas turbines.  

PubMed

The project SAMPLE evaluated methods for measuring particle properties in the exhaust of aircraft engines with respect to the development of standardized operation procedures for particulate matter measurement in aviation industry. Filter-based off-line mass methods included gravimetry and chemical analysis of carbonaceous species by combustion methods. Online mass methods were based on light absorption measurement or used size distribution measurements obtained from an electrical mobility analyzer approach. Number concentrations were determined using different condensation particle counters (CPC). Total mass from filter-based methods balanced gravimetric mass within 8% error. Carbonaceous matter accounted for 70% of gravimetric mass while the remaining 30% were attributed to hydrated sulfate and noncarbonaceous organic matter fractions. Online methods were closely correlated over the entire range of emission levels studied in the tests. Elemental carbon from combustion methods and black carbon from optical methods deviated by maximum 5% with respect to mass for low to medium emission levels, whereas for high emission levels a systematic deviation between online methods and filter based methods was found which is attributed to sampling effects. CPC based instruments proved highly reproducible for number concentration measurements with a maximum interinstrument standard deviation of 7.5%. PMID:21425830

Petzold, Andreas; Marsh, Richard; Johnson, Mark; Miller, Michael; Sevcenco, Yura; Delhaye, David; Ibrahim, Amir; Williams, Paul; Bauer, Heidi; Crayford, Andrew; Bachalo, William D; Raper, David

2011-04-15

131

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

Microsoft Academic Search

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

Ju Zhang

2004-01-01

132

Particulate Scrubbing Performance of the High Level Caves Off-Gas System  

SciTech Connect

Performance tests were conducted at the ETF using off-gas from the Small Cylindrical Melter (SCM) -2. The purpose of these tests was to develop data for comparing small and full scale equipment performance. This reports discusses those test results.

Wright, G.T.

2001-08-16

133

Gas-Phase OH Oxidation of Monoterpenes: Gaseous and Particulate Products  

Microsoft Academic Search

Smog chamber experiments have beenconducted in which cyclic monoterpenes were oxidisedin the gas phase by OH. The evolved secondary organicaerosol (SOA) was analysed by LC-MSn and thegas-phase products were analysed by FT-IR. Theconcentrations of the identified compoundscorresponded to carbon mass balances in the range of40%–90%. The identified compounds in the particularphase corresponded to 0.5%–4.2% of the reactedcarbon. The most abundant

Bo. R. Larsen; Dario Di Bella; Marianne Glasius; Richard Winterhalter; Niels R. Jensen; Jens Hjorth

2001-01-01

134

Particulate Matter  

MedlinePLUS

... EPA Home Air & Radiation Six Common Pollutants Particulate Matter Announcements March 13, 2013 - An updated “Strategies ... for over 300 cities across the U.S. "Particulate matter," also known as particle pollution or PM, is ...

135

A Gas-Kinetic Stability Analysis of Self-Gravitating and Collisional Particulate Disks with Application to Saturn's Rings  

E-print Network

Linear theory is used to determine the stability of the self-gravitating, rapidly (and nonuniformly) rotating, two-dimensional, and collisional particulate disk against small-amplitude gravity perturbations. A gas-kinetic theory approach is used by exploring the combined system of the Boltzmann and the Poisson equations. The effects of physical collisions between particles are taken into account by using in the Boltzmann kinetic equation a Krook model integral of collisions modified to allow collisions to be inelastic. It is shown that as a direct result of the classical Jeans instability and a secular dissipative-type instability of small-amplitude gravity disturbances (e.g. those produced by a spontaneous perturbation and/or a companion system) the disk is subdivided into numerous irregular ringlets, with size and spacing of the order of the Jeans length (= (4-6) mean epicyclic radius). The present research is aimed above all at explaining the origin of various structures in highly flattened, rapidly rotating systems of mutually gravitating particles. In particular, it is suggested that forthcoming Cassini spacecraft high-resolution images may reveal this kind of hyperfine of the order of 100 m structure in the main rings A, B, and C of the Saturnian ring system.

Evgeny Griv; Michael Gedalin; David Eichler; Chi Yuan

2000-12-03

136

Real-time analysis of metals in stack gas using argon/air inductively coupled plasma with optical emission spectrometry  

NASA Astrophysics Data System (ADS)

The design and operation of an instrument capable of continuous, real-time detection of hazardous air pollutant metals in the effluent of boilers, incinerators, and furnaces is reported. A commercially available inductively coupled argon plasma spectrometer, modified for introduction of sample air, provides sensitivity for several metals comparable to that of EPA-approved manual methods, with an analysis result reported every 1 to 2 minutes. Achievable detection limits for the present list of hazardous air pollutant metals range from 0.1 to 20 (mu) g/dry standard cubic meter. Air is isokinetically extracted from a stack or duct and introduced into the argon plasma through an innovative sample transport interface. Data is reported after every measurement cycle and immediately archived to a control computer, where the information is available to a local area network. The entire instrument is automated, and is enclosed in a shelter that can be placed as near as possible to the stack. The measurement of sample losses in the transport line is also discussed.

Meyer, Gerhard; Seltzer, Michael D.

1999-02-01

137

Distribution of toxic and radiation components in air particulates.  

PubMed

The concentrations of several toxic heavy metals and volatile organic compounds (VOCs) in various types of Hungarian fly-ash fine particulates were investigated by means of instrumental neutron activation analysis, X-ray fluorescence analysis and gas chromatography, coupled with mass spectrometry. Within a power station, particulate samples were taken from the boiler zone (BO), from the electrostatic dust filter chamber (FI) and from the flue-gas at the top of the stack (ST). Enrichment rates of the toxic metals both in FI and ST particulate fractions related to the BO concentrations were calculated to enable the temperature dependence on the adsorption of the toxic components to be studied. In addition, both the total amounts of the VOCs and their partial distributions in accordance with the number of carbon atoms were also studied in fly-ash particulates. From them, 31 organic species were identified and determined. Since Hungarian brown coals have high uranium and thorium contents, the specific radioactivities of the daughter isotopes of both the 232Th and 238U decay series were also measured and are discussed. PMID:8560225

Rausch, H; Sziklai, I L; Borossay, J; Torkos, K; Rikker, T; Zemplén-Papp, E

1995-12-01

138

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

139

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

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

2009-01-01

140

Effect of gas phase and particulate phase of cigarette smoke on salivary antioxidants. What can be the role of vitamin C and pyridoxine?  

PubMed

The effect of smoking is in our days a serious global public health problem of major concern. Incidence of oral squamous cell carcinoma (SCC) in cigarette smokers is four to seven times higher than in nonsmokers. There is a constant and direct attack of various cigarette smoke constituents on the oral epithelial cells, which gradually accumulate and cause malignant transformation. Saliva is the first biological fluid that encounters inhaled cigarette smoke (CS). We have studied the influence of CS on salivary antioxidant capacity, uric acid, amylase and LDH (lactate dehydrogenase). In our study both, gas and particulate phase of CS were tested separately, and possible antioxidant effect of pyridoxine on salivary components was examined. Our results indicate that exposure to both, gas and particulate phase of CS caused a statistically significant decrease in salivary uric acid, LDH and amylase activity. We have also studied the effect of vitamin C (10 mg/dl) and vitamin B6 (1 mM) during incubation of saliva in the presence of CS. The addition of vitamin C had a significant (p < 0.05) protective effect on salivary uric acid level (0.25 +/- 0.12 for saliva incubated with gas phase of CS vs. 0.65 +/- 0.12 for saliva incubated with gas phase of CS in the presence of vitamin C). Vitamin C was not able to maintain/restore the original uric acid level. In the presence of the gas phase, pyridoxine had no protective effect, neither on salivary uric acid level nor on the FRAP activity of saliva. The purpose of our study was to discover a connection between the level of antioxidants in saliva in the presence of the two components of CS. Our results show that salivary antioxidant system is significantly and distinctly affected by both gas and particulate phase of CS and suggest that an adequate intake of antioxidants may help smokers to avoid CS-induced oxidative damage and to prevent degenerative diseases. PMID:18048964

Greabu, Maria; Battino, Maurizio; Totan, Alexandra; Mohora, Maria; Mitrea, Niculina; Totan, Cosmin; Spinu, Tudor; Didilescu, Andreea

2007-01-01

141

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

142

Gas chromatography/matrix isolation-infrared spectrometry for the identification of polycyclic aromatic hydrocarbons in urban-air particulate matter  

SciTech Connect

The capabilities of gas chromatography/matrix isolation-infrared (GC/MI-IR) spectrometry for detecting and identifying polycyclic aromatic hydrocarbons (PAHs) in urban air particulate matter are demonstrated. The ability of GC/MI-IR to discriminate between PAH isomers that are difficult to distinguish by conventional electron-impact ionization gas chromatography/mass spectrometry is shown. The MI-IR spectra of PAHs obtained under GC/MI-IR conditions are comparable to those reported in the literature that were obtained by using slow-spray-on matrix deposition techniques.

Childers, J.W.; Wilson, N.K.; Barbour, R.K.

1989-01-01

143

Composition, toxicity, and mutagenicity of particulate and semivolatile emissions from heavy-duty compressed natural gas-powered vehicles.  

PubMed

Particulate matter (PM) and vapor-phase semivolatile organic compounds (SVOC) were collected from three buses fueled by compressed natural gas. The bus engines included a well-functioning, conventional engine; a "high emitter" engine; and a new technology engine with an oxidation catalyst. Chemical analysis of the emissions showed differences among these samples, with the high emitter sample containing markers of engine oil constituents. PM + SVOC samples were also collected for mutagenicity and toxicity testing. Extraction efficiencies from the collection media were lower than for similarly collected samples from gasoline or diesel vehicles. Responses to the recovered samples were compared on the basis of exhaust volume, to incorporate the emission rates into the potency factors. Mutagenicity was assessed by Salmonella reverse mutation assay. Mutagenicity was greatest for the high emitter sample and lowest for the new technology sample. Metabolic activation reduced mutagenicity in strain TA100, but not TA98. Toxicity, including inflammation, cytotoxicity, and parenchymal changes, was assessed 24 h after intratracheal instillation into rat lungs. Lung responses were generally mild, with little difference between the responses to equivalent volumes of emissions from the normal emitter and the new technology, but greater responses for the high emitter. These emission sample potencies are further compared on the basis of recovered mass with previously reported samples from normal and high-emitter gasoline and diesel vehicles. While mutagenic potencies for the CNG emission samples were similar to the range observed in the gasoline and diesel emission samples, lung toxicity potency factors were generally lower than those for the gasoline and diesel samples. PMID:15976195

Seagrave, JeanClare; Gigliotti, Andrew; McDonald, Jacob D; Seilkop, Steven K; Whitney, Kevin A; Zielinska, Barbara; Mauderly, Joe L

2005-09-01

144

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 ...

145

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

146

Development of thermal desorption gas chromatography/mass spectrometry as a rapid method for ambient particulate characterization  

NASA Astrophysics Data System (ADS)

A direct thermal desorption gas chromatography/mass spectrometry (TD GC/MS) method for air particulate matter (PM) analysis of volatile and semivolatile organic compounds was investigated. This technique uses a specially designed microdesorption GC inlet utilizing an inductively heated ferromagnetic foil with a Curie point temperature suitable for desorption, which can accommodate microgram amounts of material deposited on a thin strip of quartz fiber filter. Liquid or solid samples can be rapidly desorbed within 10 s at 315°C, followed by 30--40 min of chromatography time. The results obtained by this technique were found to be statistically equivalent to those obtained by the conventional solvent extraction gas chromatography/mass spectrometry (SX GC/MS) method for analysis of aromatic and n alkane standards, single source soot particles, and PM 10 filter samples. Correlations between injecting an extract, desorbing an extract, and desorbing particles averaged R = 0.94, with a three way correlation averaging R = 0.97. High volume sampling conducted at 12 spatially distributed sites located along the US/Mexican border of the El Paso/Juarez metroplex supplied 24h PM 10 filters for an investigation combining thermal desorption with a rapid online chemical derivatization procedure, and multivariate methods of source attribution using principal component and canonical correlation analysis of the resultant chemical markers. Four major combustion related PM emission sources were revealed at these sites: automotive, waste burning, biomass burning and meat cooking. A second investigation conducted in the same area used mediumvolume sampling to collect 2 h timeresolved PM 10 receptor samples for TD GC/MS analysis. Additionally, 2 h samples for inorganic analysis, multichannel particle size distribution measurements, and meteorological data were collected enabling generation of circadian PM multicharacterization profiles. Factor analysis based receptor modeling using principal component analysis of the mixed characterization data resulted in the deconvolution of temporally overlapping PM events, trends and gradients. Results of the temporally resolved PM receptor sampling profiles confirmed the results of the spatially distributed PM receptor sampling in that the major sources were attributed to automotive traffic, biomass and waste combustion. However, in the time resolved data, urban dust events---in particular a large evening PM peak---were seen to play a more prominent role.

Sheya, Sue Anne N.

147

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

148

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

149

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...

150

Physics and chemistry of E-beam stack gas processing. Final report, 20 September 1982-14 January 1984  

SciTech Connect

The purpose of this program is to investigate some of the basic physics and chemistry of the electron beam induced NO/sub x/ and SO/sub x/ removal process. The program involves both kinetic modelling and diagnostic development. The development of an adequate kinetic model is necessary in order to scale the laboratory results, which are currently available, to process conditions closer to those that will be encountered at full scale operation. It is also necessary in order to place the laboratory data on a firm theoretical foundation. The development of real time optical diagnostics is a necessary supporting task for these goals in order to obtain kinetic data on some of the myriad of species that are present in this hostile environment (X-rays present; hot, acidic gas) which is difficult to access by conventional methods. This particular NO/sub x//SO/sub x/ removal process involves the irradiation of combustion products t temperatures around 100/sup 0/C with a beam of high energy electrons. The current study expands upon the mechanistic studies. A detailed kinetic model is described which includes all the necessary assumptions that enter in order to take the very large number of possible processes that occur in e-beam irradiated mixtures and reduce them to some tractable number. Quantitative comparisons are then made between the kinetic model and experimental data. Another phase of this program is the development of laser diagnostics to probe various species in the irradiated flue gas. The experimental phase of program is first described including a discussion of our e-beam facility and the methods used to accurately measure energy deposition. A description of the laser diagnostics follows. 37 references, 22 figures, 7 tables.

Slater, R.

1983-10-01

151

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...

152

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

153

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

154

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

155

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

NASA Astrophysics Data System (ADS)

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 effect of various stack parameters on temperature rise and cooling. The results verify that the cathode gas flow has a predominant effect on the maximum temperature inside the stack while the inlet and heating temperatures have limited influence. This explains the need for pressurized operations for control of stack temperature.

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

156

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

157

Apparatus and process for removing contaminants from a flowing gas stream  

US Patent & Trademark Office Database

An apparatus and process for removing regulated pollutants and other contaminants from a flowing gas stream between a scrubber and an exhaust stack. The apparatus comprises a vessel having a heater chamber, an adsorbent chamber and a filter chamber. The vessel inlet receives the gas stream from the scrubber and the vessel outlet discharges clean gas to the exhaust stack. A heater in the heater chamber heats the incoming gas stream to lower the relative humidity. The gas stream then passes through granular adsorbent material located in the adsorbent chamber to remove contaminants remaining after the wet scrubber. From the adsorbent chamber the gas stream flows into the filter chamber where filters remove entrained particulate matter prior to discharge to the exhaust stack. The process of the present invention includes the above-described steps.

2006-03-21

158

40 CFR Appendix Vi to Part 266 - Stack Plume Rise  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack Plume Rise VI Appendix VI to Part 266...App. VI Appendix VI to Part 266—Stack Plume Rise [Estimated Plume Rise (in Meters) Based on Stack Exit Flow Rate and Gas Temperature]...

2010-07-01

159

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

Code of Federal Regulations, 2011 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...120-94 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2011-07-01

160

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

Code of Federal Regulations, 2012 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...1320-90 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2012-07-01

161

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

Code of Federal Regulations, 2012 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...120-94 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2012-07-01

162

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

Code of Federal Regulations, 2013 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...120-94 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2013-07-01

163

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

Code of Federal Regulations, 2010 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...120-94 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2010-07-01

164

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

Code of Federal Regulations, 2010 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...1320-90 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2010-07-01

165

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

Code of Federal Regulations, 2011 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...1320-90 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2011-07-01

166

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

Code of Federal Regulations, 2013 CFR

... false Gas meter or flow instrumentation calibration...AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...1320-90 Gas meter or flow instrumentation calibration...practice. (2) Flow air through the...

2013-07-01

167

Understanding Java Stack Inspection  

Microsoft Academic Search

Current implementations of Java make security decisions by searching the runtime call stack. These systems have attractive security properties, but they have been criticized as being dependent on specific artifacts of the Java imple- mentation. This paper models the stack inspection algorithm in terms of a well-understood logic for access control and demonstrates how stack inspection is a useful tool

Dan S. Wallach; Edward W. Felten

1998-01-01

168

Regenerable particulate filter  

DOEpatents

A method of making a three-dimensional lattice structure, such as a filter used to remove particulates from a gas stream, where the physical lattice structure is designed utilizing software simulation from pre-defined mass transfer and flow characteristics and the designed lattice structure is fabricated using a free-form fabrication manufacturing technique, where the periodic lattice structure is comprised of individual geometric elements.

Stuecker, John N. (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Miller, James E. (Albuquerque, NM)

2009-05-05

169

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.

170

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

171

40 CFR 60.1360 - What records must I keep for stack tests?  

Code of Federal Regulations, 2012 CFR

...measure specified in table 1 of this subpart: (1) Dioxins/furans. (2) Cadmium. (3) Lead. (4) Mercury. (5...particulate matter control device during all stack tests for dioxins/furans emissions. (d) The calendar date of each...

2012-07-01

172

40 CFR 62.15300 - What records must I keep for stack tests?  

Code of Federal Regulations, 2011 CFR

...specified in tables 2 or 4 of this subpart: (1) Dioxins/furans. (2) Cadmium. (3) Lead. (4) Mercury. (5...particulate matter control device during all stack tests for dioxins/furans emissions. (d) The calendar date of each...

2011-07-01

173

40 CFR 60.1845 - What records must I keep for stack tests?  

Code of Federal Regulations, 2010 CFR

...measure specified in table 2 or 4 of this subpart: (1) Dioxins/furans. (2) Cadmium. (3) Lead. (4) Mercury...particulate matter control device during all stack tests for dioxins/furans emissions. (d) The calendar date of each...

2010-07-01

174

40 CFR 62.15300 - What records must I keep for stack tests?  

Code of Federal Regulations, 2010 CFR

...measure specified in tables 2 or 4 of this subpart: (1) Dioxins/furans. (2) Cadmium. (3) Lead. (4) Mercury...particulate matter control device during all stack tests for dioxins/furans emissions. (d) The calendar date of each...

2010-07-01

175

Polycyclic aromatic hydrocarbons in gas and particulate phases of indoor environments influenced by tobacco smoke: Levels, phase distributions, and health risks  

NASA Astrophysics Data System (ADS)

As polycyclic aromatic hydrocarbons (PAHs) have a negative impact on human health due to their mutagenic and/or carcinogenic properties, the objective of this work was to study the influence of tobacco smoke on levels and phase distribution of PAHs and to evaluate the associated health risks. The air samples were collected at two homes; 18 PAHs (the 16 PAHs considered by U.S. EPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) were determined in gas phase and associated with thoracic (PM 10) and respirable (PM 2.5) particles. At home influenced by tobacco smoke the total concentrations of 18 PAHs in air ranged from 28.3 to 106 ng m -3 (mean of 66.7 ± 25.4 ng m -3), ? PAHs being 95% higher than at the non-smoking one where the values ranged from 17.9 to 62.0 ng m -3 (mean of 34.5 ± 16.5 ng m -3). On average 74% and 78% of ? PAHs were present in gas phase at the smoking and non-smoking homes, respectively, demonstrating that adequate assessment of PAHs in air requires evaluation of PAHs in both gas and particulate phases. When influenced by tobacco smoke the health risks values were 3.5-3.6 times higher due to the exposure of PM 10. The values of lifetime lung cancer risks were 4.1 × 10 -3 and 1.7 × 10 -3 for the smoking and non-smoking homes, considerably exceeding the health-based guideline level at both homes also due to the contribution of outdoor traffic emissions. The results showed that evaluation of benzo[a]pyrene alone would probably underestimate the carcinogenic potential of the studied PAH mixtures; in total ten carcinogenic PAHs represented 36% and 32% of the gaseous ? PAHs and in particulate phase they accounted for 75% and 71% of ? PAHs at the smoking and non-smoking homes, respectively.

Castro, Dionísia; Slezakova, Klara; Delerue-Matos, Cristina; Alvim-Ferraz, Maria da Conceição; Morais, Simone; Pereira, Maria do Carmo

2011-04-01

176

Stacks, Queues and Tracks  

Microsoft Academic Search

This paper studies stack, queue, and track layouts of graph subdivisions. It is known that every graph has a 3-stack subdivision. The best known upper bound on the number of division vertices per edge in a 3-stack subdivision of an n-vertex graph G is improved from O(log n) to O(log minfsn(G);qn(G)g). This result reduces the question of whether queue-number is

David R. Wood

177

Fluid&ParticulateSystems 424514/2010  

E-print Network

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&ParticulateSystems �A424514/2012 Vertical two-phase (G/L) flows RoNz 6 Downward Patterns depend on relative velocities

Zevenhoven, Ron

178

The development of a cyclonic combustor for high particulate, low caloric value gas produced by a fluidized bed  

E-print Network

for inlet Reynolds number in the range of 4. 5 x 10 to 6. 5 x 10 and equivalence ratio between 0. 7 and 1. 0. The flame length and shape varied greatly at the various operating conditions. High levels of NO/NOx emissions were measured and believed... Number on System Static Fuel Pressure 43 6 The Effect of Inlet Reynolds Number on Dimensionless Pressure Drop 46 7 Variation of Exiting Gas Temperature with Equivalence Ratio 48 8 The Effect of Equivalence Ratio on Manifold Gas Temperature 51 9...

Cardenas, Manuel Moises

2012-06-07

179

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...

180

Computational Science - Stack Exchange  

NSDL National Science Digital Library

This is a free, community driven Q&A for scientists using computers to solve scientific problems. It is a part of the Stack Exchange network of Q&A websites, and it was created through the open democratic process defined at Stack Exchange Area 51.

181

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

182

Evaluation of PCDD/F congener distributions in MWI flue gas treated with SCR catalysts.  

PubMed

Partitioning of PCDD/F congeners between gaseous and particulate phases and removal efficiencies of the air pollution control devices (APCDs) for PCDD/Fs at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS) and selective catalytic reduction system (SCR) as APCDs. The average PCDD/F concentration of stack gas is 1.49 ng/Nm3, and the International Toxic Equivalent Quantity (I-TEQ) is 0.043 ng-I-TEQ/Nm3. The EP increases PCDD/F concentration by 174.0% while the average removal efficiency of WS+SCR system for PCDD/Fs reaches 99.1%. In addition, the PCDF removal efficiency achieved with WS+SCR system (97.1-99.8%) is higher than that for PCDDs (96.5-99.3%). The results obtained on gas/particulate partitioning in flue gas indicate that the particulate-phase PCDD/Fs accounted for 65% at the inlet of EP, 20% at the outlet of EP and 50% at the stack, respectively, of the total PCDD/F concentrations. This study also indicates that as the chlorination level of PCDD/F congeners increases, the percentage of PCDD/Fs existing in gas phase decreases in all flue gas samples. PMID:15099725

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

2004-06-01

183

Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 1: gaseous and particulate matter emissions.  

PubMed

Growing concern over emissions from increased airport operations has resulted in a need to assess the impact of aviation related activities on local air quality in and around airports, and to develop strategies to mitigate these effects. One such strategy being investigated is the use of alternative fuels in aircraft engines and auxiliary power units (APUs) as a means to diversify fuel supplies and reduce emissions. This paper summarizes the results of a study to characterize the emissions of an APU, a small gas turbine engine, burning conventional Jet A-1, a fully synthetic jet fuel, and other alternative fuels with varying compositions. Gas phase emissions were measured at the engine exit plane while PM emissions were recorded at the exit plane as well as 10 m downstream of the engine. Five percent reduction in NO(x) emissions and 5-10% reduction in CO emissions were observed for the alternative fuels. Significant reductions in PM emissions at the engine exit plane were achieved with the alternative fuels. However, as the exhaust plume expanded and cooled, organic species were found to condense on the PM. This increase in organic PM elevated the PM mass but had little impact on PM number. PMID:22913288

Lobo, Prem; Rye, Lucas; Williams, Paul I; Christie, Simon; Uryga-Bugajska, Ilona; Wilson, Christopher W; Hagen, Donald E; Whitefield, Philip D; Blakey, Simon; Coe, Hugh; Raper, David; Pourkashanian, Mohamed

2012-10-01

184

Assessing the co-benefits of greenhouse gas reduction: health benefits of particulate matter related inspection and maintenance programs in Bangkok, Thailand.  

PubMed

Since the 1990s, the capital city of Thailand, Bangkok has been suffering from severe ambient particulate matter (PM) pollution mainly attributable to its wide use of diesel-fueled vehicles and motorcycles with poor emission performance. While the Thai government strives to reduce emissions from transportation through enforcing policy measures, the link between specific control policies and associated health impacts is inadequately studied. This link is especially important in exploring the co-benefits of greenhouse gas emissions reductions, which often brings reduction in other pollutants such as PM. This paper quantifies the health benefits potentially achieved by the new PM-related I/M programs targeting all diesel vehicles and motorcycles in the Bangkok Metropolitan Area (BMA). The benefits are estimated by using a framework that integrates policy scenario development, exposure assessment, exposure-response assessment and economic valuation. The results indicate that the total health damage due to the year 2000 PM emissions from vehicles in the BMA was equivalent to 2.4% of Thailand's GDP. Under the business-as-usual (BAU) scenario, total vehicular PM emissions in the BMA will increase considerably over time due to the rapid growth in vehicle population, even if the fleet average emission rates are projected to decrease over time as the result of participation of Thailand in post-Copenhagen climate change strategies. By 2015, the total health damage is estimated to increase by 2.5 times relative to the year 2000. However, control policies targeting PM emissions from automobiles, such as the PM-oriented I/M programs, could yield substantial health benefits relative to the BAU scenario, and serve as co-benefits of greenhouse gas control strategies. Despite uncertainty associated with the key assumptions used to estimate benefits, we find that with a high level confidence, the I/M programs will produce health benefits whose economic impacts considerably outweigh the expenditures on policy implementation. PMID:21334726

Li, Ying; Crawford-Brown, Douglas J

2011-04-15

185

Trace gas and particle emissions from open burning of three cereal crop residues: Increase in residue moistness enhances emissions of carbon monoxide, methane, and particulate organic carbon  

NASA Astrophysics Data System (ADS)

We determined emission factors for open burning of straw of rice, wheat, and barley, as well as rice husks, and we incorporated the effects of moisture content on the emission factors for the straw. A closed system that simulated on-site backfiring of residues on the soil surface under moderate wind conditions was used to measure the gas and particle emissions from open burning of the residues on an upland field. Two moisture content conditions were evaluated: a dry condition (air-dried residues, 11-13% by weight) and a moist condition (20%). When a linear regression model with the initial moisture content of the residue as the explanatory variable showed good correlation between the primary emission data of a substance and the moisture content, the regression model was adopted as a function to give the emission factors. Otherwise, the unmodified primary data were used as the emission factors. The magnitudes of the gas and particle emissions differed among the residue types. For example, carbon monoxide (CO) emissions from straw of rice, wheat, and barley and rice husks burned under the dry condition were 27.2 ± 1.7, 41.8 ± 24.2, 46.9 ± 2.1, and 66.1 g kg-1 dry matter, and emissions of methane (CH4) were 0.75 ± 0.01, 2.01 ± 0.93, 1.47 ± 0.06, and 5.81 g kg-1 dry matter, respectively (n = 2 for straw with the standard deviation; n = 1 for husks). Emissions of carbon-containing gases and particles (e.g., CO, CH4, and particulate organic carbon) were higher under the moist condition than under the dry condition, which suggests that emission factors for open burning should incorporate the effects of moisture content except open burning performed in the dry season or arid zones.

Hayashi, Kentaro; Ono, Keisuke; Kajiura, Masako; Sudo, Shigeto; Yonemura, Seiichiro; Fushimi, Akihiro; Saitoh, Katsumi; Fujitani, Yuji; Tanabe, Kiyoshi

2014-10-01

186

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

187

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...

188

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

189

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

190

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

...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...

2014-07-01

191

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

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

192

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

193

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

194

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

195

Size Distribution An Gas/particle Partitionig of Particulate Pah and Elements In The Case of The La Defense Road Tunnel Near Paris  

NASA Astrophysics Data System (ADS)

The aim of this study is to characterise, in real circulation conditions, the physico- chemistry of the French automotive emissions. Pollutants measured in a road tunnel are not photochemically processed and thus do represent the original emission at its source. Furthermore, the wide distribution of car types encountered in real circula- tion conditions assures representativety of the actual (French) car park. The French automotive emissions are also of particular interest because the proportion of Diesel engines is bigger than in other countries. Particles were sampled in the La Défense Road tunnel using a Dekati 13 stage cascade impactor as well as a total collector with PM10 head. A biphasic collector was used to study the gas/particle partitioning of the PAHs. The concentration of 14 PAHs was determined in each size fraction by using microwave extraction followed by HPLC in connection with a fluorimeter. Par- ticulate concentration of elements (Al,S,Ca,Cl,Pd,Pt,Ce,Rh...) were determined using X-Ray fluorescence. Environmental conditions, such as temperature, pressure, rela- tive humidity, wind speed as well as CO and NOx levels were monitored continuously during the campaign. The results show clearly that light PAHs, such as phenanthrene, acenaphtene or fluorene exhibit a bimodal distribution. They are adsorbed on fine par- ticles (maximum at about 200 nm) as well as on coarse particles (maximum at about 4 micron). In contrast, heavier PAHs, like Benz(a)pyrene or Benzofluoranthene, are found only on fine particles. Due to its elevated vapour pressure, naphtalene is not observed at all in the particulate phase. These results will be discussed in terms of the thermodynamic properties of the compounds and are compared to similar campaigns in other countries.

Quisefit, J.-P.; Garivait, S.; Schwell, M.; Goriaux, M.; Steiner, E.

196

76. General view looking east showing Rust Co. boiler stacks ...  

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

76. General view looking east showing Rust Co. boiler stacks at left, Babcock & Wilcox type boiler stacks at right, Dovel horizontal gas washer in foreground, and No. 1 Furnace in distance. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

197

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

198

Emissions of SO2, NOx and particulates from a pipe manufacturing plant and prediction of impact on air quality.  

PubMed

Integrated pipe manufacturing industry is operation intensive and has significant air pollution potential especially when it is equipped with a captive power production facility. Emissions of SO(2), NO(x), and particulate matter (PM) were estimated from the stationary sources in a state-of-the-art pipe manufacturing plant in India. Major air polluting units like blast furnace, ductile iron spun pipe facility, and captive power production facility were selected for stack gas monitoring. Subsequently, ambient air quality modeling was undertaken to predict ground-level concentrations of the selected air pollutants using Industrial Source Complex (ISC 3) model. Emissions of SO(2), NO(x), and particulate matter from the stationary sources in selected facilities ranged from 0.02 to 16.5, 0.03 to 93.3, and 0.09 to 48.3 kg h(-1), respectively. Concentration of SO(2) and NO(x) in stack gas of 1,180-kVA (1 KW = 1.25 kVA) diesel generator exceeded the upper safe limits prescribed by the State Pollution Control Board, while concentrations of the same from all other units were within the prescribed limits. Particulate emission was highest from the barrel grinding operation, where grinding of the manufactured pipes is undertaken for giving the final shape. Particulate emission was also high from dedusting operation where coal dust is handled. Air quality modeling indicated that maximum possible ground-level concentration of PM, SO(2), and NO(x) were to the tune of 13, 3, and 18 microg/m(3), respectively, which are within the prescribed limits for ambient air given by the Central Pollution Control Board. PMID:19888663

Bhanarkar, A D; Majumdar, Deepanjan; Nema, P; George, K V

2010-10-01

199

Investigation of time-resolved atmospheric conditions and indoor/outdoor particulate matter concentrations in homes with gas and biomass cook stoves in Nogales, Sonora, Mexico.  

PubMed

This paper reports findings from a case study designed to investigate indoor and outdoor air quality in homes near the United States-Mexico border During the field study, size-resolved continuous particulate matter (PM) concentrations were measured in six homes, while outdoor PM was simultaneously monitored at the same location in Nogales, Sonora, Mexico, during March 14-30, 2009. The purpose of the experiment was to compare PM in homes using different fuels for cooking, gas versus biomass, and to obtain a spatial distribution of outdoor PM in a region where local sources vary significantly (e.g., highway, border crossing, unpaved roads, industry). Continuous PM data were collected every 6 seconds using a valve switching system to sample indoor and outdoor air at each home location. This paper presents the indoor PM data from each home, including the relationship between indoor and outdoor PM. The meteorological conditions associated with elevated ambient PM events in the region are also discussed. Results indicate that indoor air pollution has a strong dependence on cooking fuel, with gas stoves having hourly averaged median PM3 concentrations in the range of 134 to 157 microg m(-3) and biomass stoves 163 to 504 microg m(-1). Outdoor PM also indicates a large spatial heterogeneity due to the presence of microscale sources and meteorological influences (median PM3: 130 to 770 microg m(-3)). The former is evident in the median and range of daytime PM values (median PM3: 250 microg m(-3), maximum: 9411 microg m(-3)), while the meteorological influences appear to be dominant during nighttime periods (median PM3: 251 microg m(-3), maximum: 10,846 microg m(-3)). The atmospheric stability is quantified for three nighttime temperature inversion episodes, which were associated with an order of magnitude increase in PM10 at the regulatory monitor in Nogales, AZ (maximum increase: 12 to 474 microg m(-3)). Implications: Regulatory air quality standards are based on outdoor ambient air measurements. However, a large fraction of time is typically spent indoors where a variety of activities including cooking, heating, tobacco smoking, and cleaning can lead to elevated PM concentrations. This study investigates the influence of meteorology, outdoor PM, and indoor activities on indoor air pollution (IAP) levels in the United States-Mexico border region. Results indicate that cooking fuel type and meteorology greatly influence the IAP in homes, with biomass fuel use causing the largest increase in PM concentration. PMID:25122950

Holmes, Heather A; Pardyjak, Eric R

2014-07-01

200

Development of a 50 kW, high efficiency, high power density, CO-tolerant PEM fuel cell stack system  

Microsoft Academic Search

Honeywell has been developing a 50-kW net proton exchange membrane (PEM) fuel cell stack system for transportation applications. The stack system is comprised of a PEM fuel cell stack and supporting gas, thermal and water management subsystems and is capable of integration with a number of fuel processors. The present effort focuses on system design and analysis, stack technology development,

T. Rehg; R. Loda; N. Minh

2000-01-01

201

A novel configuration for direct internal reforming stacks  

NASA Astrophysics Data System (ADS)

This paper presents a stack concept that can be applied to both molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) internal reforming stacks. It employs anode recycle and allows the design of very simple system configurations, while giving enhanced efficiencies and high specific power densities. The recycle of anode exit gas to the anode inlet has previously been proposed as a means of preventing carbon deposition in direct internal reforming (DIR) stacks. When applied to a normal stack this reduces the Nernst voltages because the recycle stream is relatively depleted in hydrogen. In the concept proposed here, known as the `Smarter' stack, there are two anode exit streams, one of which is depleted, while the other is relatively undepleted. The depleted stream passes directly to the burner, and the undepleted stream is recycled to the stack inlet. By this means high Nernst voltages are achieved in the stack. The concept has been simulated and assessed for parallel-flow and cross-flow MCFC and SOFC stacks and graphs are presented showing temperature distributions. The `Smarter' stacks employ a high recycle rate resulting in a reduced natural gas concentration at the stack inlet, and this reduces or eliminates the unfavourable temperature dip. Catalyst grading can further improve the temperature distribution. The concept allows simple system configurations in which the need for fuel pre-heat is eliminated. Efficiencies are up to 10 percentage points higher than for conventional stacks with the same cell area and maximum stack temperature. The concept presented here was devised in a project part-funded by the EU, and has been adopted by the European Advanced DIR-MCFC development programme led by BCN.

Fellows, Richard

202

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.

Youngman, Betsy; Pennycook, Jean; Huffman, Louise; Dahlman, Luann; Nebraska, Andrill- U.

203

Inertia Coin Stack Challenge  

NSDL National Science Digital Library

In this activity, learners experiment with inertia by performing an easy and hands-on investigation with a playing card and a stack of coins. The activity includes an accompanying Mr. O video which explores Newton's First Law of Motion and inertia in greater detail. Suggestions for extra challenge: add more coins, try different cards.

Houston, Children'S M.

2011-01-01

204

In-stack virtual impactor  

SciTech Connect

The MRI in-stack virtual impactor is a unique instrument that can provide real-time continuous measurements of stack aerosol particle-size distributions and can simultaneously provide size-segregated samples for morphological or chemical analysis.

Woffinden, G.J.; Downs, J.L.; Markowski, G.R.; Fegley, M.J.

1982-02-01

205

The Effect of a Computer Instructional Model in Bringing about a Conceptual Change in Students' Understanding of Particulate Concepts of Gas  

Microsoft Academic Search

This study explores students' misconceptions with the particulate concept of matter in gaseous state. Then, based on promoting students' learning and understanding from a constructivist per- spective, the effectiveness of instructional activities by presenting a demonstration with computer simulation was investigated. Students were expected to benefit from computer monitored instruc- tion in a number of ways: by becoming more interested

Bao-tyan Hwang; Shang-feng Chiu

2004-01-01

206

Energy Expenditure of Sport Stacking  

ERIC Educational Resources Information Center

Sport stacking is an activity taught in many physical education programs. The activity, although very popular, has been studied minimally, and the energy expenditure for sport stacking is unknown. Therefore, the purposes of this study were to determine the energy expenditure of sport stacking in elementary school children and to compare that value…

Murray, Steven R.; Udermann, Brian E.; Reineke, David M.; Battista, Rebecca A.

2009-01-01

207

Heteroaromatic ?-stacking energy landscapes.  

PubMed

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

Huber, Roland G; Margreiter, Michael A; Fuchs, Julian E; von Grafenstein, Susanne; Tautermann, Christofer S; Liedl, Klaus R; Fox, Thomas

2014-05-27

208

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

209

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

210

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

211

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

212

Nanometer-sized etching of magnetic tunnel junction stack for magnetic random access memory  

NASA Astrophysics Data System (ADS)

High-density plasma reactive ion etching of MTJ stack was investigated in an inductively coupled plasma of Cl 2/Ar and Cl 2/O 2/Ar gas mixes. Thin TiN hard mask was employed and the etching proceeded at ambient temperature. The effect of etch gas on the etch profiles of MTJ stack was examined by varying the gas concentration. In addition, the effects of etch parameters on the etch profiles and magnetic properties of MTJ stacks were investigated. The highly anisotropic etching of MTJ stack arrays with 200×200 and 100×100 nm 2 dimensions was successfully achieved.

Hyun Park, Ik; Ryun Min, Su; Hyun Park, Wang; Ho Shin, Kyung; Chung, Chee Won

2006-09-01

213

Stacking with dual bootstrap resampling  

NASA Astrophysics Data System (ADS)

A new kind of stacking scheme, based on the hypothesis testing of signal significance and coherence, is proposed. The significance of stacked data is evaluated by running two kinds of bootstrap resampling, one for standard bootstrap and the other for preparing noise stacks by scrambling relative time-shifts between traces. This dual bootstrap procedure allows us to formulate a two-sample problem for signal significance, which is shown to be more reliable than standard bootstrap estimates. The statistics of noise obtained in dual bootstrap resampling is also used when assessing the coherence of data with the empirical distribution function, in which the effect of noise is deconvolved by rescaling. Unlike conventional non-linear stacks such as Nth-root stack and phase-weighted stack, the new stack can recover signals even when the signal-to-noise ratio (S/N) is low, and compared to simple linear stack, the number of traces required for unambiguous signal detection is reduced by up to two orders of magnitude. The new scheme, called dual bootstrap stack, could facilitate a range of geophysical data processing when trying to detect subtle signals by stacking low S/N data.

Korenaga, Jun

2013-12-01

214

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

215

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

216

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

217

40 CFR 60.1795 - May I conduct stack testing less often?  

Code of Federal Regulations, 2013 CFR

...stack testing requirements: dioxins/furans, cadmium, lead, mercury, particulate...You can test less often for dioxins/furans emissions if you own or operate a municipal...have demonstrated levels of dioxins/furans emissions less than or equal to...

2013-07-01

218

40 CFR 62.15250 - May I conduct stack testing less often?  

Code of Federal Regulations, 2013 CFR

...stack testing requirements: dioxins/furans, cadmium, lead, mercury, particulate...You can test less often for dioxins/furans emissions if you own or operate a municipal...have demonstrated levels of dioxins/furans emissions less than or equal to...

2013-07-01

219

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...

220

COMPARISON OF OPACITY MEASUREMENTS BY TRAINED OBSERVER AND IN-STACK TRANSMISSOMETER  

EPA Science Inventory

Measurements of opacity of particulate emissions by trained observer and by instack transmissometer were compared on 26 different occasions at 17 different stacks and 13 different plants to see how well these two commonly used methods would agree when applied to real plants under...

221

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

222

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

223

Microtubular, single-chamber solid oxide fuel cell (MT–SC-SOFC) stacks: Model development  

Microsoft Academic Search

Our previously developed numerical model has been used to study the flow, species and temperature distribution in a micro-tubular, single-chamber solid oxide fuel cell stack. The stack consists of three cells, spaced equally inside the gas-chamber. Two different configurations of the gas-chamber have been investigated, i.e., a bare gas-chamber and a porous material filled gas-chamber. The results show that the

N. Akhtar

224

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

225

In-stack virtual impactor  

SciTech Connect

In-stack virtual impactor described is a unique instrument that can provide real-time continuous measurements of stack aerosol particle-size distributions and can simultaneously provide size-segregated samples for morphological or chemical analysis. 2 references, 12 figures, 1 table.

Woffinden, G.J.; Downs, J.L.; Markowski, G.R.; Fegley, M.J.

1982-02-01

226

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

227

Assessing Elementary Algebra with STACK  

ERIC Educational Resources Information Center

This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

Sangwin, Christopher J.

2007-01-01

228

Face crack reduction strategy for particulate filters  

DOEpatents

A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion. A control module initiates combustion of PM in the PM filter using a heater and selectively adjusts oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter. A method comprises providing a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion; initiating combustion of PM in the PM filter using a heater; selectively adjusting oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter.

Gonze, Eugene V [Pinckney, MI

2012-01-31

229

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...

230

Radiant zone heated particulate filter  

SciTech Connect

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

231

Flat descent for Artin n-stacks  

Microsoft Academic Search

We prove two flat descent statements for Artin n-stacks. We first show that an n-stack for the etale topology which is an Artin n-stack in the sense of HAGII, is also an n-stack for the fppf topology. Moreover, an n-stack for the fppf topology which possess a fppf n-atlas is an Artin n-stack (i.e. possesses a smooth n-atlas). We deduce

Bertrand Toen; Case Courrier; Eugene Bataillon

2009-01-01

232

Simulation of particles and gas flow behavior in the riser section of a circulating fluidized bed using the kinetic theory approach for the particulate phase  

Microsoft Academic Search

Gas\\/particle flow behavior in the riser section of a circulating fluidized bed (CFB) was simulated using a computational fluid dynamics (CFD) package by Fluent. Fluid catalytic cracking (FCC) particles and air were used as the solid and gas phases, respectively.A two-dimensional, transient and isothermal flow was simulated for the continuous phase (air) and the dispersed phase (solid particles). Conservation equations

S. Benyahia; H. Arastoopour; T. M. Knowlton; H. Massah

2000-01-01

233

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

234

Nanometer-sized etching of magnetic tunnel junction stack for magnetic random access memory  

Microsoft Academic Search

High-density plasma reactive ion etching of MTJ stack was investigated in an inductively coupled plasma of Cl2\\/Ar and Cl2\\/O2\\/Ar gas mixes. Thin TiN hard mask was employed and the etching proceeded at ambient temperature. The effect of etch gas on the etch profiles of MTJ stack was examined by varying the gas concentration. In addition, the effects of etch parameters

Ik Hyun Park; Su Ryun Min; Wang Hyun Park; Kyung Ho Shin; Chee Won Chung

2006-01-01

235

DESIGN ASPECTS OF A 250 KW NG FUELLED SOFC SYSTEM - STRATEGIES TO COUNTERACT STACK PERFORMANCE DEGRADATION  

Microsoft Academic Search

Haldor Topsøe A\\/S, Denmark (HTAS), and Wärtsilä Corporation, Finland, have jointly carried out a conceptual study on a 250 kW natural gas based SOFC system for decentralised power and heat applications. An issue in this study was how to design and operate the plant to counteract degradation of the stack performance. In principle three methods are available; increasing the stack

J. Hansen; J. Pålsson; J. Nielsen; E. Fontell; T. Kivisaari; P. Jumppanen; P. Hendriksen

236

Stochastic Behaviour of the Electricity Bid Stack: from Fundamental Drivers to Power Prices  

E-print Network

Stochastic Behaviour of the Electricity Bid Stack: from Fundamental Drivers to Power Prices Michael) 23 October 2008 Abstract We develop a fundamental model for spot electricity prices, based prices with observed data. Keywords: electricity, bid stack, fundamental, margin, demand, natural gas 1

Howison, Sam

237

Calibration of the Alnor Duct Jet (Double Pitot Tube) with Sectioned Extensions for Stack Sampling  

Microsoft Academic Search

Fly-ash loading of stack gas frequently precludes velocity measurements with a standard Pitot tube due to plugging of the static pressure holes. The use of a double Pitot tube obviates this difficulty, but in the lengths commercially available its use is restricted to stacks of about 30 inches in diameter. Calibration charts are presented demonstrating that an 18-inch double Pitot

Eugene D. Kennedy; Lynn D. Wilson

1964-01-01

238

Comparative study of engine control strategies for particulate emissions from direct injection light-duty vehicle fueled with gasoline and liquid phase liquefied petroleum gas (LPG)  

Microsoft Academic Search

To evaluate the potential of a dedicated direct injection liquefied petroleum gas (LPG-DI) vehicle, we investigated several engine control parameters that are closely related to the characteristics of mixture preparation and nano-particle emissions. The fuel supply circuit for the direct injection of LPG in liquid form was modified into a return-type system comprised of a three-way high pressure pump, a

Cha-Lee Myung; Juwon Kim; Kwanhee Choi; In Goo Hwang

239

Stacking interactions and DNA intercalation  

SciTech Connect

The relationship between stacking interactions and the intercalation of proflavine and ellipticine within DNA is investigated using a nonempirical van der Waals density functional for the correlation energy. Our results, employing a binary stack model, highlight fundamental, qualitative differences between base-pair base-pair interactions and that of the stacked intercalator base pair system. Most notable result is the paucity of torque which so distinctively defines the Twist of DNA. Surprisingly, this model, when combined with a constraint on the twist of the surrounding base-pair steps to match the observed unwinding of the sugar-phosphate backbone, was sufficient for explaining the experimentally observed proflavine intercalator configuration. Our extensive mapping of the potential energy surface of base-pair intercalator interactions can provide valuable information for future nonempirical studies of DNA intercalation dynamics.

Li, Dr. Shen [Fred Hutchinson Cancer Research Center; Cooper, Valentino R [ORNL; Thonhauser, Prof. Timo [Wake Forest University, Winston-Salem, NC; Lundqvist, Prof. Bengt I. [Chalmers University of Technology, Sweden; Langreth, David C. [Rutgers University

2009-01-01

240

Preliminary study of airborne particulate matter in a Beijing sampling station by instrumental neutron activation analysis  

Microsoft Academic Search

A long-term study on airborne particulate matter (APM) and air pollution trend in Beijing has been undertaken supported by International Atomic Energy Agency (IAEA) and National Natural Science Foundation of China. Sampling was carried out using Gent stacked filter unit sampler at a sampling station (traffic representative) in Beijing city. Two hundred and ten samples were collected during 1999 and

Lei Cao; Weizhi Tian; Bangfa Ni; Yangmei Zhang; Pingsheng Wang

2002-01-01

241

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

242

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

243

Anharmonic stacking in supercoiled DNA  

NASA Astrophysics Data System (ADS)

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.

Zoli, Marco

2012-05-01

244

PARTICULATE MATTER SUPERSITES PROGRAM  

EPA Science Inventory

Background: In promulgating the new PM2.5 NAAQS (July 1997), Congress recognized scientific uncertainties associated with fine particulate matter to include composition, source-receptor relationships, and health and exposure effects. As a result, Congress provided EPA with dire...

245

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

246

Particulate-removal system upgraded with pulse-jet baghouse  

SciTech Connect

A pulse-jet baghouse installed on a flue gas side-stream enhanced the performance of a small precipitator on Philadelphia Electric Co.'s Cromby unit 1 and enabled it to meet particulate standards. Pulse-jet baghouses have a gentle cleaning action that prolongs fabric life as well as improving particulate removal efficiency to the required 90%. Details of the baghouse design and operation are given. 2 figures. (DCK)

Ingram, T.

1983-08-01

247

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Fluid and Particulate Engineering ron.zevenhoven@abo.fi 3Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Flow Around BodiesFluid&ParticulateSystems 424514/2010

Zevenhoven, Ron

248

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

249

V-stack piezoelectric actuator  

NASA Astrophysics Data System (ADS)

Aeroelastic control of wings by means of a distributed, trailing-edge control surface is of interest with regards to maneuvers, gust alleviation, and flutter suppression. The use of high energy density, piezoelectric materials as motors provides an appealing solution to this problem. A comparative analysis of the state of the art actuators is currently being conducted. A new piezoelectric actuator design is presented. This actuator meets the requirements for trailing edge flap actuation in both stroke and force. It is compact, simple, sturdy, and leverages stroke geometrically with minimum force penalties while displaying linearity over a wide range of stroke. The V-Stack Piezoelectric Actuator, consists of a base, a lever, two piezoelectric stacks, and a pre-tensioning element. The work is performed alternately by the two stacks, placed on both sides of the lever. Pre-tensioning can be readily applied using a torque wrench, obviating the need for elastic elements and this is for the benefit of the stiffness of the actuator. The characteristics of the actuator are easily modified by changing the base or the stacks. A prototype was constructed and tested experimentally to validate the theoretical model.

Ardelean, Emil V.; Clark, Robert L.

2001-07-01

250

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

251

Stack Components Nancy L. Garland  

E-print Network

catalysts · Recent SBIR topic (DOE Office of Science): non- precious metal catalysts · Emphasis · New-Pt and non-precious metal catalysts - cost reduction and improved cathode performance · Bipolar plates - cost solicitation: stack durability, cost reduction and high temperature membranes, and non- precious metal

252

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

253

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 particles.

Cionco, Rodolfo G; Caligaris, Marta G

2012-01-01

254

Stacked Sequential Learning William W. Cohen  

E-print Network

learning". Stacked se- quential learning is a meta-learning algorithm, in which an arbitrary base learner boosting, stacked sequential learning is a meta-learning method, in which an arbitrary base learner

Cohen, William W.

255

Development and Applications of a Stage Stacking Procedure  

NASA Technical Reports Server (NTRS)

The preliminary design of multistage axial compressors in gas turbine engines is typically accomplished with mean-line methods. These methods, which rely on empirical correlations, estimate compressor performance well near the design point, but may become less reliable off-design. For land-based applications of gas turbine engines, off-design performance estimates are becoming increasingly important, as turbine plant operators desire peaking or load-following capabilities and hot-day operability. The current work develops a one-dimensional stage stacking procedure, including a newly defined blockage term, which is used to estimate the off-design performance and operability range of a 13-stage axial compressor used in a power generating gas turbine engine. The new blockage term is defined to give mathematical closure on static pressure, and values of blockage are shown to collapse to curves as a function of stage inlet flow coefficient and corrected shaft speed. In addition to these blockage curves, the stage stacking procedure utilizes stage characteristics of ideal work coefficient and adiabatic efficiency. These curves are constructed using flow information extracted from computational fluid dynamics (CFD) simulations of groups of stages within the compressor. Performance estimates resulting from the stage stacking procedure are shown to match the results of CFD simulations of the entire compressor to within 1.6% in overall total pressure ratio and within 0.3 points in overall adiabatic efficiency. Utility of the stage stacking procedure is demonstrated by estimation of the minimum corrected speed which allows stable operation of the compressor. Further utility of the stage stacking procedure is demonstrated with a bleed sensitivity study, which estimates a bleed schedule to expand the compressors operating range.

Kulkarni, Sameer; Celestina, Mark L.; Adamczyk, John J.

2012-01-01

256

Eighth particulate control symposium  

SciTech Connect

The Eighth Symposium on the Transfer and Utilization of Particulate Control Technology was held in San Diego, California, March 20 through 23, 1990. The symposium proceedings contain 80 papers presented by representatives of utility companies, equipment and process suppliers, university representatives, research and development companies, EPA and other federal and state agency representatives, and EPRI staff members. Electrostatic precipitators and fabric filters were the major topics discussed during the symposium. Papers from this conference are organized by session in two volumes. This Volume (2) contains papers presented in the sessions on: low ratio baghouse O M experience, pulse-jet baghouse experience, particulate control for AFBCs, particulate control for dry SO2 control processes, baghouse design and performance, fundamental baghouse studies, high temperature filtration, and control of emissions from RDF incinerators. Both fabric filters and ESPs are discussed in the AFBC and dry SO2 control papers. The high temperature filtration papers deal with ceramic barrier and granular bed filters. The rest of the papers in Volume 2 are concerned with fabric filters on pulverized-coal-fired boilers. Individual projects are processed separately for the data bases.

Not Available

1990-11-01

257

3-D Stacked Package Technology and Trends  

Microsoft Academic Search

The need to integrate more device technology in a given board space for handheld applications such as mobile phones has driven the adoption of innovative packages which stack such devices in the vertical or third dimension (3D). Stacking of device chips in small and thin fine-pitch ball grid array packages has evolved into the stacking of packages themselves to achieve

Flynn P. Carson; Young Cheol Kim; In Sang Yoon

2009-01-01

258

Do Stack Traces Help Developers Fix Bugs?  

Microsoft Academic Search

A widely shared belief in the software engineering community is that stack traces are much sought after by developers to support them in debugging. But limited empirical evidence is available to confirm the value of stack traces to developers. In this paper, we seek to provide such evidence by conducting an empirical study on the usage of stack traces by

Rahul Premraj; Adrian Schröter; Nicolas Bettenburg

2010-01-01

259

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

260

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

261

Feature-Weighted Linear Stacking  

Microsoft Academic Search

Ensemble methods, such as stacking, are designed to boost predictive accuracy\\u000aby blending the predictions of multiple machine learning models. Recent work\\u000ahas shown that the use of meta-features, additional inputs describing each\\u000aexample in a dataset, can boost the performance of ensemble methods, but the\\u000agreatest reported gains have come from nonlinear procedures requiring\\u000asignificant tuning and training time.

Joseph Sill; Gábor Takács; Lester Mackey; David Lin

2009-01-01

262

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

263

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

264

Fabrication and performance evaluation of 3-cell SOFC stack based on planar 10 cm × 10 cm anode-supported cells  

Microsoft Academic Search

This study reports the development of planar-type solid oxide fuel cell (SOFC) stacks based on an internal gas manifold and a cross-flow type design. A single-columned, 3-cell, SOFC stack is assembled using 10cm×10cm anode-supported unit cells, metallic interconnects and glass-based compression-seal gaskets. The power-generating characteristics of the unit cell and stack are characterized as a function of temperature. The practical

H. Y. Jung; S.-H. Choi; H. Kim; J.-W. Son; J. Kim; H.-W. Lee; J.-H. Lee

2006-01-01

265

Etch characteristics of magnetic tunnel junction stack with nanometer-sized patterns for magnetic random access memory  

Microsoft Academic Search

Etch characteristics of magnetic tunnel junction (MTJ) stack masked with TiN films were investigated using an inductively coupled plasma reactive ion etcher in Cl2\\/Ar and BCl3\\/Ar gases for magnetic random access memory. The effect of etch gas on the etch profile of MTJ stacks was examined. As Cl2 and BCl3 concentrations increased, the etch slope of etched MTJ stack became

Su Ryun Min; Han Na Cho; Kee Won Kim; Young Jin Cho; Sung-Hoon Choa; Chee Won Chung

2008-01-01

266

Stacks  

ERIC Educational Resources Information Center

Linton Waters and Jayne Kranat ran a session on the Nuffield "Applying Mathematical Processes" (AMP) activities at BCME7 in Manchester in April this year. These 1-2 hour activities are revamps of some of the Graded Assessment in Mathematics (GAIM) resources, developed in the 1980s, and are freely available via the Nuffield website and the original…

Kimber, Lizzie

2010-01-01

267

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

E-print Network

In this paper we give a construction of algebraic (Artin) stacks endowed with a modular map onto the moduli stack of n-pointed stable curves of genus g, for g greater than 2. These stacks are smooth, irreducible and have dimension 4g-3+n, yielding a geometrically meaningful compactification of the degree d universal Picard stack over the moduli stack of smooth curves with marked points.

Melo, Margarida

2008-01-01

268

Electrostatic precipitator for metal and particulate emission control  

SciTech Connect

Improving air pollution control systems is crucial for incinerators to be an option for sewage sludge disposal. Combinations of venturi and tray tower scrubbers are the most popular air pollution control system for sewage sludge incinerators. Recently wet electrostatic precipitators have been installed downstream of the scrubbing system to ensure the compliance of new regulations. Performance and stack tests were conducted on sludge incinerators at Somerset Raritan Valley Sewage Authority and New England Treatment Company. Efficiencies in terms of heavy metal and particulate removals are presented. This paper also describes sewage sludge incinerators, existing air pollution control systems, design considerations of the wet electrostatic precipitator, as well as sampling and analysis methods.

Yang, C.L.; Beltran, M.

2000-03-01

269

Unabated emission source term estimate for the 340-NX stack  

SciTech Connect

This document contains the sampling procedure, analytical results, and source term estimate from sampling work conducted on the main stack for the 340 Facility`s vault ventilation system. Several air filter and carbon cartridges were collected upstream of the KI off-gas control modules in order to determine the challenge source terms associated with various operating modes (e.g., under routine waste storage, during waste mixing, during waste transfer, etc.)

Stordeur, R.T.; Glissmeyer, J.A., Fluor Daniel Hanford

1997-03-19

270

Analyzing Stack Flows to Compare Java Programs  

NASA Astrophysics Data System (ADS)

This paper presents a method for comparing and detecting clones of Java programs by analyzing program stack flows. A stack flow denotes an operational behavior of a program by describing individual instructions and stack movements for performing specific operations. We analyze stack flows by simulating the operand stack movements during execution of a Java program. Two programs for detection of clones of Java programs are compared by matching similar pairs of stack flows in the programs. Experiments were performed on the proposed method and compared with the earlier approaches of comparing Java programs, the Tamada, k-gram, and stack pattern based methods. Their performance was evaluated with real-world Java programs in several categories collected from the Internet. The experimental results show that the proposed method is more effective than earlier methods of comparing and detecting clones of Java programs.

Lim, Hyun-Il; Han, Taisook

271

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

272

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2014 Fluid and Particulate Zevenhoven �A Thermal and Flow Engineering ron.zevenhoven@abo.fi 8Fluid&ParticulateSystems 424514/2010 Fluid Strömningsteknik Biskopsgatan 8, FI-20500 �bo / Turku Finland #12;Fluid&ParticulateSystems 424514/2010 Fluid

Zevenhoven, Ron

273

Effect of isothermal aging on the mechanical performance of brazed ceramic\\/metal joints for planar SOFC-stacks  

Microsoft Academic Search

One of the key requirements for the application of planar solid oxide fuel cells is the hermetical sealing of ceramic and metallic stack-components. Gas tightness and associated mechanical integrity of the sealants are therefore key prerequisites for reliable operation over the lifetime of the stack. To withstand mechanical stresses generated by the differences in thermal expansion of the involved materials

B. Kuhn; E. Wessel; J. Malzbender; R. W. Steinbrech; L. Singheiser

2010-01-01

274

Apparatus for flaring gas  

SciTech Connect

This patent describes an apparatus for flaring gas. It comprises: flare stack means, having a base, for flaring gas; fluid pit means for storing fluid; gooseneck pipe means, coupled to the base of the flare stack means and to the fluid pit means. The gooseneck pipe means being configured to maintain a reservoir of fluid therein at a predetermined level; high pressure inlet means for introducing a first combination of waste gas and liquid of a first predetermined pressure or greater, into the flare stack means; low pressure inlet means for introducing a second combination of waste gas and liquid, of a second predetermined pressure less than that of the first predetermined pressure, into the flare stack means; and means for routing the liquid separated from the first and second combination of waste gas and liquid into the gooseneck pipe.

Zimmiond, L.

1990-01-09

275

PARTICULATE CONTROL FOR FUGITIVE DUST  

EPA Science Inventory

The report gives results of a study of particulate control for fugitive dust. Study results indicate that many Air Quality Control Regions (AQCRs) do not meet ambient air standards for particulates. In a majority of these ACQRs, the emissions from fugitive dust sources are higher...

276

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

277

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Fluid and Particulate.zevenhoven@abo.fi 2Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 2.1 Flow tube sections-20500 Ã?bo / Turku Finland RoNz 2januari 2014 #12;Fluid&ParticulateSystems 424514/2010 Fluid

Zevenhoven, Ron

278

Nonlinear identification of a DIR-SOFC stack using wavelet networks  

Microsoft Academic Search

Application of wavelet networks for identification of a direct internal reforming solid oxide fuel cell (DIR-SOFC) stack is reported in this paper. The SOFC is a complex system particularly when it is directly fueled with hydrocarbons (natural gas, coal gas, etc.). Most of the traditional models of the SOFC, based on the reforming, electrochemical and thermal modeling, are too complicated.

Jun Li; Ying-Wei Kang; Guang-Yi Cao; Xin-Jian Zhu; Heng-Yong Tu; Jian Li

2008-01-01

279

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

280

Spacecraft particulate sizing spectrometer  

NASA Technical Reports Server (NTRS)

An evaluation prototype device is described, together with conclusions and several recommendations for follow-on flight hardware. The device detects individual particles crossing an external sensing zone, and produces a histogram displaying the size distribution of particles sensed, over the nominal range of 5 to 50 microns. The output is totally independent of the particle refractive index, and is also largely unaffected by particle shape. The reported diameters are in terms of the equivalent sphere, as judged by the scattered light intercepted by the receiving channels, which develop signals whenever a particle crosses the beam of illumination in the sensing zone. Supporting evidence for the latter assertion is discussed on the basis of experimental test data for non-spherical particulates. Also included is a technical appendix which presents theoretical arguments that provide a firm foundation for this assertion.

Miranda, Henry A., Jr.

1992-01-01

281

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

282

Hydrogen Embrittlement And Stacking-Fault Energies  

NASA Technical Reports Server (NTRS)

Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

Parr, R. A.; Johnson, M. H.; Davis, J. H.; Oh, T. K.

1988-01-01

283

Manifold seal for fuel cell stack assembly  

DOEpatents

An assembly for sealing a manifold to a stack of fuel cells includes a first resilient member for providing a first sealing barrier between the manifold and the stack. A second resilient member provides a second sealing barrier between the manifold and the stack. The first and second resilient members are retained in such a manner as to define an area therebetween adapted for retaining a sealing composition.

Schmitten, Phillip F. (N. Huntingdon, PA); Wright, Maynard K. (Bethel Park, PA)

1989-01-01

284

One-dimensional wave propagation in particulate suspensions  

NASA Technical Reports Server (NTRS)

One-dimensional small-amplitude wave motion in a two-phase system consisting of an inviscid gas and a cloud of suspended particles is analyzed using a continuum theory of suspensions. Laplace transform methods are used to obtain several approximate solutions. Properties of acoustic wave motion in particulate suspensions are inferred from these solutions.

Rochelle, S. G.; Peddieson, J., Jr.

1976-01-01

285

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...

286

Inductively heated particulate matter filter regeneration control system  

SciTech Connect

A system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas, a downstream end and zones. The system also includes a heating element. A control module selectively activates the heating element to inductively heat one of the zones.

Gonze, Eugene V; Paratore Jr., Michael J; Kirby, Kevin W; Phelps, Amanda; Gregoire, Daniel J

2012-10-23

287

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

288

Toward the Complete Characterization of Atmospheric Organic Particulate Matter: Derivatization and Two-Dimensional Comprehensive Gas Chromatography/Time of Flight Mass Spectrometry as a Method for the Determination of Carboxylic Acids  

NASA Astrophysics Data System (ADS)

Understanding the composition of atmospheric organic particulate matter (OPM) is essential for predicting its effects on climate, air quality, and health. However, the polar oxygenated fraction (PO-OPM), which includes a significant mass contribution from carboxylic acids, is difficult to speciate and quantitatively determine by current analytical methods such as gas chromatography-mass spectrometry (GC-MS). The method of chemical derivatization and two-dimensional GC with time of flight MS (GCxGC/TOF-MS) was examined in this study for its efficacy in: 1) quantifying a high percentage of the total organic carbon (TOC) mass of a sample containing PO-OPM; 2) quantitatively determining PO-OPM components including carboxylic acids at atmospherically relevant concentrations; and 3) tentatively identifying PO-OPM components. Two derivatization reagent systems were used in this study: BF3/butanol for the butylation of carboxylic acids, aldehydes, and acidic ketones, and BSTFA for the trimethylsilylation (TMS) of carboxylic acids and alcohols. Three alpha-pinene ozonolysis OPM filter samples and a set of background filter samples were collected by collaborators in a University of California, Riverside environmental chamber. Derivatization/GCxGC TOF-MS was used to tentatively identify some previously unidentified ?-pinene ozonolysis products, and also to show the characteristics of all oxidation products determined. Derivatization efficiencies as measured were 40-70% for most butyl derivatives, and 50-58% for most trimethylsilyl derivatives. A thermal optical method was used to measure the TOC on each filter, and a value of the quantifiable TOC mass using a gas chromatograph was calculated for each sample using GCxGC separation and the mass-sensitive response of a flame ionization detector (FID). The TOC quantified using TMS and GCxGC-FID (TMS/TOCGCxGC FID) accounted for 15-23% of the TOC measured by the thermal-optical method. Using TMS and GCxGC/TOF-MS, 8.85% of the thermal optical TOC was measured and 48.2% of the TMS/TOCGCxGC-FID was semi-quantified using a surrogate standard. The carboxylic acids tentatively identified using TMS and GCxGC/TOF-MS accounted for 8.28% of the TOC measured by thermal optical means. GCxGC TOF-MS chromatograms of derivatized analytes showed reduced peak tailing due in part to the lesser interactions of the derivatized analytes with the stationary phase of the chromatography column as compared to the chromatograms of underivatized samples. The improved peak shape made possible the greater separation, quantification, and identification of high polarity analytes. Limits of detection using derivatization and GCxGC/TOF-MS were <1 ng per ?L injected for a series of C2-C6 di-acids, cis-pinonic acid, and dodecanoic acid using both butylation and TMS. Derivatization with GCxGC/TOF-MS was therefore effective for determining polar oxygenated compounds at low concentrations, for determining specific oxidation products not previously identified in OPM, and also for characterizing the probable functional groups and structures of ?-pinene ozonolysis products.

Boris, Alexandra Jeanne

289

Gaseous and particulate air pollutants in the Northeastern Mediterranean Coast  

Microsoft Academic Search

The concentrations of sulfur dioxide (SO2), ammonia (NH3) and particulate matter were measured for a 6-month period and the concentration of gas phase nitric acid (HNO3) was measured for a 1-month period in the North-eastern Mediterranean atmosphere (Küçük Çalticak, Antalya) using a ‘filter pack’ system that was developed and optimised in our laboratory. Among all the gas phase pollutants, HNO3

M Soner Erduran; Semra G Tuncel

2001-01-01

290

Development of a hot isostatic pressing process for manufacturing silicon carbide particulate reinforced iron  

E-print Network

it has many derivatives. For particulate reinforced MMCs, these include squeeze casting, compocasting/semi-solid forming, reactive processing, and centrifugal casting. Squeeze casting uses a heated die into which a mixture of molten metal and solid... particulates is forced. ' An alternate form of this, gas pressure casting, uses gas pressure instead of a die, thus saving equipment and tooling costs. '0 Compocasting is the process in which the matrix is heated to a temperature between the liquidus...

Oakeson, David Oscar

2012-06-07

291

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

292

Scaled Tests and Modeling of Effluent Stack Sampling Location Mixing  

SciTech Connect

The Pacific Northwest National Laboratory researchers used a computational fluid dynamics (CFD) computer code to evaluate the mixing at a sampling system location of a research and development facility. The facility requires continuous sampling for radioactive air emissions. Researchers sought to determine whether the location would meet the criteria for uniform air velocity and contaminant concentration as prescribed in the American National Standard Institute (ANSI) standard, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities. Standard ANSI/HPS N13.1-1999 requires that the sampling location be well-mixed and stipulates specific tests (e.g., velocity, gas, and aerosol uniformity and cyclonic flow angle) to verify the extent of mixing.. The exhaust system for the Radiochemical Processing Laboratory was modeled with a CFD code to better understand the flow and contaminant mixing and to predict mixing test results. The CFD results were compared to actual measurements made at a scale-model stack and to the limited data set for the full-scale facility stack. Results indicated that the CFD code provides reasonably conservative predictions for velocity, gas, and aerosol uniformity. Cyclonic flow predicted by the code is less than that measured by the required methods. In expanding from small to full scale, the CFD predictions for full-scale measurements show similar trends as in the scale model and no unusual effects. This work indicates that a CFD code can be a cost-effective aid in design or retrofit of a facility’s stack sampling location that will be required to meet Standard ANSI/HPS N13.1-1999.

Recknagle, Kurtis P.; Yokuda, Satoru T.; Ballinger, Marcel Y.; Barnett, J. M.

2009-02-01

293

Heat exchange system for recycling stack heat  

Microsoft Academic Search

A heat exchange system is described for recycling waste heat leaving a building stack to supply heat to incoming fresh air or temper stored water of the building water storage system, wherein the building has a source of heat at constant temperature, such as a cooking facility, from which air conveying waste heat is drawn and impelled through a stack

Giuffre

1980-01-01

294

Context adaptation of the communication stack  

Microsoft Academic Search

This paper presents a middleware framework to support the development of context-aware adaptive communication protocols stacks. The protocol stacks can be reconfigured according not only to the local context, but also to the context of the remaining remote participants. The context information and the current node configuration feed a Markov decision process that is used to derive the appropriate reconfigurations.

José Mocito; Liliana Rosa; Nuno Almeida; Hugo Miranda; Luís Rodrigues; Antónia Lopes

2006-01-01

295

Sleepy Stack Reduction of Leakage Power  

E-print Network

;Favored input vector Faster recovery than sleep approach An optimal input vector is pre-loaded No recovery Voltage Transistors Stack effect #12;Stack Induce a reverse bias in cutoff Sleep Disconnect Vdd/Gnd when possibility Sleep transistors can be slow Additional routing S and complement "Virtual" Vdd / Gnd State

Mooney, Vincent

296

The Stack of Rational Nodal Curves  

Microsoft Academic Search

In this series of three papers we start to investigate the rational Chow ring of the stack consisting of nodal curves of genus 0, in particular we determine completely the rational Chow ring of the substack consisting of curves with at most 3 nodes. In this first paper we construct the stack of rational nodal curves and its stratification by

Damiano Fulghesu

2009-01-01

297

Project W-420 stack monitoring system upgrades  

SciTech Connect

This project will execute the design, procurement, construction, startup, and turnover activities for upgrades to the stack monitoring system on selected Tank Waste Remediation System (TWRS) ventilation systems. In this plan, the technical, schedule, and cost baselines are identified, and the roles and responsibilities of project participants are defined for managing the Stack Monitoring System Upgrades, Project W-420.

CARPENTER, K.E.

1999-02-25

298

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

299

Electrically heated particulate filter restart strategy  

SciTech Connect

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

300

EFFECT OF GEOMETRY AND OPERATING PARAMETERS ON SIMULATED SOFC STACK TEMPERATURE UNIFORMITY  

SciTech Connect

A uniform temperature field is desirable in the solid oxide fuel cell stack to avoid local hot regions that contribute to material degradation, thermal stresses, and differences in electrochemical performance. Various geometric and operational design changes were simulated by numerical modeling of co-flow and counter-flow multi-cell stacks, and the effects on stack maximum temperature, stack temperature difference, and maximum cell temperature difference were characterized. The results showed that 40-60% on-cell steam reforming of methane and a reduced reforming rate of 25-50% of the nominal rate was beneficial for a more uniform temperature field. Fuel exhaust recycling up to 30% was shown to be advantageous for reforming fuels and co-flow stacks with hydrogen fuel, but counter-flow stacks with hydrogen fuel showed higher temperature differences. Cells with large aspect ratios showed a more uniform temperature response due to either the strong influence of the inlet gas temperatures or the greater thermal exchange with the furnace boundary condition. Improved lateral heat spreading with thicker interconnects was demonstrated, but greater improvements towards a uniform thermal field for the same amount of interconnect mass could be achieved using thicker heat spreader plates appropriately distributed along the stack height.

Koeppel, Brian J.; Lai, Canhai; Khaleel, Mohammad A.

2011-08-10

301

Electrical diesel particulate filter (DPF) regeneration  

SciTech Connect

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

302

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

303

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

304

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

305

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height regulations. 52.1388 Section...CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height regulations should EPA complete...

2012-07-01

306

40 CFR 52.345 - Stack height regulations.  

...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

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 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height regulations. 52.1388 Section...CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height regulations should EPA complete...

2010-07-01

309

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

310

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height regulations. 52.1388 Section...CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height regulations should EPA complete...

2011-07-01

311

40 CFR 52.2347 - Stack height regulations.  

...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

312

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

313

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

314

40 CFR 52.1388 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height regulations. 52.1388 Section...CONTINUED) Montana § 52.1388 Stack height regulations. The State of Montana has committed to revise its stack height regulations should EPA complete...

2013-07-01

315

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

316

Army tests show stack flow restrictors save little energy  

SciTech Connect

Government performance tests of flue-stack flow restrictors made by Thermiser Ltd. and Thrifty Vents show only minor improvement in the efficiency of gas-fired furnaces. The Army tested the devices as a guideline for army bases after approaches by several vendors, and will soon release its full report on 288 separate tests. Both products are designed to reduce the amount of air to be heated. Furnace derating had the greatest effect on efficiency during the tests. Similar tests by the Naval Energy and Environmental Support Activity showed no significant savings. Both the Army and Navy tests are challenged by the manufacturers. (DCK)

Galvin, C.

1982-10-04

317

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

318

Improvement of phosphoric acid fuel cell stacks  

NASA Astrophysics Data System (ADS)

Phosphoric acid fuel cell components and stack assembly methods were evaluated. Electrodes with Pt loading between 0.3 and 0.9 g/sq. ft were employed. Matrix materials were phenolic (Kynol) fibers and SiC. A new ERC proprietary matrix was used also. Graphite bipolar plates with 33% phenolic resin binder were used. Stacks were tested on hydrogen and simulated reformed methanol for up to 18,000 hours. Two 80 cell (2.1 kW) stacks and a methanol reformer were built and delivered to MERADCOM.

Abens, S. G.; Ascenzo, F. J.; Baker, B. S.; Garretson, G.; Lambrech, M.

1980-07-01

319

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

320

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

321

Hydrocarbon-enhanced particulate filter regeneration via microwave ignition  

SciTech Connect

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

322

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

SciTech Connect

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

323

Turbulent particulate transportation during electrostatic precipitation  

NASA Astrophysics Data System (ADS)

The generation of secondary flows and turbulence by a corona discharge influences particle transport in an electrostatic precipitator (ESP), and is known to play an important role in the particle collection process. However, it is difficult to characterise theoretically and experimentally the ``turbulent'' fluctuations of the gas flow produced by negative tuft corona. Because of this difficulty, only limited studies have been undertaken previously to understand the structure of corona-induced turbulence and its influence on particle transport in ESPs. The present study is aimed at modelling electrohydrodynamic turbulent flows and particle transport, and at establishing an unproved understanding of them. For a multiply interactive coupling of electrostatics, fluid dynamics and particle dynamics, a strongly coupled system of the governing equations has been solved. The present computer model has considered the most important interaction mechanisms including an ionic wind, corona- induced turbulence and the particle space charge effect. Numerical simulations have been performed for the extensive validation of the numerical and physical models. To account for electrically excited turbulence associated with the inhomogeneous and unsteady characteristics of negative corona discharges, a new turbulence model (called the electrostatic turbulence model) has been developed. In this, an additional production or destruction term is included into the turbulent kinetic energy and dissipation rate equations. It employs a gradient type model of the current density and an electrostatic diffusivity concept. The results of the computation show that the electrostatic turbulence model gives much better agreement with the experimental data than the conventional RNG k-? turbulence model when predicting turbulent gas flows and particle distributions in an ESP. Computations of turbulent particulate two-phase flows for both mono-dispersed and poly-dispersed particles have been performed. The effects of coriona-induced turbulence and the particle space charge on particle transport and the collection process have been investigated. The calculated results for the poly-dispersed particulate flow were compared with those of the mono-dispersed particulate flow, and significant differences were demonstrated. It is established that effective particle- particle interaction occurs, due to the influence of the particle space charge, even for dilute gas-particle flows that occur in ESPs.

Choi, Bum Seog

324

Near-Earth Asteroid Stack - Mission Animation  

NASA Video Gallery

A possible stack configuration - a deep space habitat, the Orion Multi-Purpose Crew Vehicle and Space Exploration Vehicle - approaches a near-Earth asteroid. During a mission that could take months...

325

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

326

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

327

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

328

40 CFR 61.53 - Stack sampling.  

Code of Federal Regulations, 2010 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...

2010-07-01

329

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

330

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

331

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2012 CFR

...Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF...F). Alternative test methods which yield equivalent results may be used if...or any distortion likely to reduce its strength, cause instability in stacks of...

2012-10-01

332

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2011 CFR

...Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF...F). Alternative test methods which yield equivalent results may be used if...or any distortion likely to reduce its strength, cause instability in stacks of...

2011-10-01

333

49 CFR 178.606 - Stacking test.  

Code of Federal Regulations, 2013 CFR

...Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF...F). Alternative test methods which yield equivalent results may be used if...or any distortion likely to reduce its strength, cause instability in stacks of...

2013-10-01

334

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

335

40 CFR 61.44 - Stack sampling.  

...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

336

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

337

40 CFR 61.33 - Stack sampling.  

...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

338

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

339

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

340

PBFA-2 vacuum insulator stack failure mechanisms  

Microsoft Academic Search

The BPFA-II accelerator includes a large-radius, vertical-axis vacuum insulator stack. The possible failure of the acrylic rings in the stack from electron- or gamma-induced charge buildup is being evaluated. The induced static charges could remain for many hours, and either type of irradiation might cause dendrites to form. Aluminum grading rings sandwiched between the acrylic affect charge accumulation; the acrylic

M. A. Sweeney

1985-01-01

341

Mesoporous bragg stack color tunable sensors.  

PubMed

Herein we report a novel self-assembly synthesis, structural and optical characterization of mesoporous Bragg stacks (MBS) composed of spin-coated multilayer stacks of mesoporous TiO(2) and mesoporous SiO(2). Investigation of the optical response of MBS to the infiltration of alcohols and alkanes into its pores reveals better sensitivity and selectivity than conventional Bragg reflectors. Furthermore, we demonstrate that the chemical sensing ability can be tuned via layer thickness, composition and surface properties. PMID:17090073

Choi, Sung Yeun; Mamak, Marc; von Freymann, Georg; Chopra, Naveen; Ozin, Geoffrey A

2006-11-01

342

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

343

High strength particulate ceramics  

DOEpatents

This invention relates to new and useful hard, dense, composite materials made from metallic nitrides such as titanium nitride when combined with aluminum oxide and aluminum nitride and a process comprising the steps of: (1) mixing constituent materials using kerosene as a mixing medium; (2) screening, settling, filtering, and washing the mixture in acetone; (3) filling and sealing said materials in a latex mold; (4) isostatically pressing the material into a compacted powder; and (5) sintering the compacted powder in a gas atmosphere at 1,850.degree. C. for two hours.

Liles, Kenneth J. (Tuscaloosa, AL); Hoyer, Jesse L. (Tuscaloosa, AL); Mlynarski, Kenneth W. (Gambrills, MD)

1991-01-01

344

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

PubMed

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 likelyto 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 limitthan 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. PMID:16786702

Clack, Herek L

2006-06-01

345

Solid oxide fuel cell generator with removable modular fuel cell stack configurations  

DOEpatents

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

1998-04-21

346

Solid oxide fuel cell generator with removable modular fuel cell stack configurations  

DOEpatents

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack.

Gillett, James E. (Greensburg, PA); Dederer, Jeffrey T. (Valencia, PA); Zafred, Paolo R. (Pittsburgh, PA); Collie, Jeffrey C. (Pittsburgh, PA)

1998-01-01

347

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

348

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

349

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...

350

Water-Gas Shift Membrane Reactor Studies  

E-print Network

Reactor Fuels and Chemicals Generator Steam Turbine Combustion Turbine Heat Recovery Steam Generator Coal, Petroleum coke, Biomass, Waste, etc. Gasifier Particulate Removal Air Separator Oxygen Air Steam Particulates Steam Solid Waste Gas Cleanup Sulfur Byproduct Compressed Air Synthesis Gas Conversion Shift

351

Particulate Matter (Environmental Health Student Portal)  

MedlinePLUS

... Waterborne Diseases & Illnesses Water Cycle Water Treatment Particulate Matter The Basics We’ve all seen dirty bathrooms ... the spring. These are visible sources of particulate matter, or PM for short. Show more PM is ...

352

NONFERROUS INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT  

EPA Science Inventory

The report gives results of the development of particulate emission factors based on cutoff size for inhalable particles for the nonferrous industry. After a review of available information characterizing particulate emissions from nonferrous plants, the data were summarized and ...

353

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...

354

Development and Characterization of a High Performance Thin-Film Planar Solid-Oxide Fuel Cell Stack  

SciTech Connect

A planar solid oxide fuel cell (SOFC) was fabricated using a tape-cast Ni/yttria-stabilized zirconia (YSZ) anode support, a YSZ thin film electrolyte, and a composite cathode of YSZ and (La{sub 0.85}Sr{sup 0.14}){sub 0.98}MnO{sub 3} (LSM). Using pure hydrogen as the fuel gas, a three cell stack with a cross-flow design and external manifolds produced peak power densities of 0.85 W/cm{sup 2} and 0.41 W/cm{sup 2} at 800 C and 700 C, respectively. Using wet methane as the fuel gas, the stack produced a peak power density of 0.22 W/cm{sup 2} at 700 C. Individual cells in the stack showed identical current-voltage (I -V) characteristics. Stack lifetime was limited because of degradation of the cells from oxidation products coming from the metallic interconnect used.

Chung, B W; Chervin, C N; Haslam, J J; Pham, A; Glass, R S

2004-04-07

355

Source Testing for Particulate Matter.  

ERIC Educational Resources Information Center

Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline covers procedures for the testing of particulate matter. These are: (1) basic requirements, (2) information required, (3) collection of samples, (4) processing of samples, (5)…

DeVorkin, Howard

356

Monitoring of particulate matter outdoors  

Microsoft Academic Search

Recent studies of the size and composition of atmospheric particulate matter (PM) have demonstrated the usefulness of separating atmospheric PM into its fine and coarse components. The need to measure the mass and composition of fine and coarse PM separately has been emphasized by research in exposure, epidemiology, and toxicology of atmospheric PM. This paper provides a background on the

W. E. Wilson; Judith C. Chow; Candis Claiborn; Wei Fusheng; Johann Engelbrecht; John G. Watson

2002-01-01

357

Excellent Passivation of p+ Silicon Surfaces by Inline Plasma Enhanced Chemical Vapor Deposited SiOx/AlOx Stacks  

NASA Astrophysics Data System (ADS)

Excellent surface passivation of boron emitters is demonstrated for industrial plasma-enhanced chemical vapor deposited (PECVD) SiOx/AlOx stacks. Emitter saturation current densities of 39 and 34 fA/cm2, respectively, were achieved at 300 K on 80 ?/sq boron emitters after activation by (i) a standard industrial firing process and (ii) a forming gas anneal followed by industrial firing. We find that the surface passivation by SiOx/AlOx stack can be effectively controlled by varying the SiOx layer thickness. This stack is directly applicable to certain high-efficiency solar cell structures, by optimising the SiOx thickness accordingly.

Lin, Fen; Duttagupta, Shubham; Shetty, Kishan D.; Boreland, Matthew; Aberle, Armin G.; Hoex, Bram

2012-10-01

358

Fluid&ParticulateSystems 424514/2010  

E-print Network

For solving mathematical problems in chemical engineering Fluid&ParticulateSystems 424514/2010 Fluid Ron Zevenhoven �A Thermal and Flow Engineering ron.zevenhoven@abo.fi 1Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2014 Fluid mechanics ­ re-wrap of basic principles januari 2014 �bo

Zevenhoven, Ron

359

Interactions of detrital particulates and plankton  

Microsoft Academic Search

Detrital particulates, i.e. inorganic and non-living organic material of colloidal size and larger, span ten orders of magnitude in size and are ubiquitous in inland waters. Interactions between plankton and detrital particulates are reciprocal. Release of dissolved organics by living organisms enter the particulate size fraction by flocculation on bubbles or adsorption to inorganic particles. Bacteria benefit from attachment to

John M. Melack

1985-01-01

360

Modifying Char Dustcake Pressure Drop Using Particulate Additives  

SciTech Connect

Coal gasification produces residual particles of coal char, coal ash, and sorbent that are suspended in the fuel gas stream exiting the gasifier. In most cases, these particles (referred to, hereafter, simply as char) must be removed from the stream prior to sending the gas to a turbine, fuel cell, or other downstream device. Currently, the most common approach to cleaning the gas stream at high temperature and pressure is by filtering the particulate with a porous ceramic or metal filter. However, because these dusts frequently have small size distributions, irregular morphology, and high specific surface areas, they can have very high gas flow resistance resulting in hot-gas filter system operating problems. Typical of gasification chars, the hot-gas filter dustcakes produced at the Power Systems Development Facility (PSDF) during recent coal gasification tests have had very high flow resistance (Martin et al, 2002). The filter system has been able to successfully operate, but pressure drops have been high and filter cleaning must occur very frequently. In anticipation of this problem, a study was conducted to investigate ways of reducing dustcake pressure drop. This paper will discuss the efficacy of adding low-flow-resistance particulate matter to the high-flow-resistance char dustcake to reduce dustcake pressure drop. The study had two parts: a laboratory screening study and confirming field measurements at the PSDF.

Landham, C.; Dahlin, R.S.; Martin, R.A.; Guan, X.

2002-09-19

361

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

362

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

363

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

364

Intelligent Control System of Stack-boiler  

NASA Astrophysics Data System (ADS)

Boiler combustion control system's basic task is to make fuel burn calories adapt to the needs of the water temperature and ensure the economical combustion and the safe operation. In the foundations which have analyzed the stack-boiler's work process and control system structure, the system designed by using the self-learning and self-optimizing fuzzy control system of the PC to make air/coal ratio achieve the best and realize the optimized combustion; through PLC to accelerate the speed of response to the boiler, and speed up the PC to optimize the speed and realize the double loop control system for stack-boiler. The control system in premise of the stack-boiler reaches the goal of the load to achieve the highest efficiency of the boiler combustion.

Jing, Li; Jingxia, Niu; Jianhua, Lang; Shaofeng, Li; Zhi, Li

365

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

366

Progress of MCFC stack technology at Toshiba  

SciTech Connect

Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

Hori, M.; Hayashi, T.; Shimizu, Y. [Toshiba Corp., Tokyo (Japan)

1996-12-31

367

Children's conception of gas  

Microsoft Academic Search

Students usually learn about gases and the particulate theory of matter in the seventh grade. The objective of this research was to study the knowledge students possess regarding the concept gas prior to and following instruction. The findings show that students do not develop spontaneously a general idea of gas prior to instruction. After instruction, they first acquire knowledge about

Ruth Stavy

1988-01-01

368

Influence of stack arrangement on performance of multiple-stack solid oxide fuel cells with non-uniform potential operation  

Microsoft Academic Search

The performance of multiple-stack solid oxide fuel cells (SOFCs) with different stack arrangements is compared with respect to the presence of an in-stack pressure drop. It was demonstrated in our previous work that when a multiple-stack SOFC is arranged in series and the operating voltages are allowed to vary among the different stacks, an improved performance over a conventional SOFC

S. Assabumrungrat; N. Ruangrassamee; S. Vivanpatarakij; N. Laosiripojana; A. Arpornwichanop

2009-01-01

369

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

370

Study of stacked microstrip phased arrays  

NASA Astrophysics Data System (ADS)

Two theoretical methods for studying stacked-patch microstrip phased arrays are compared: (1) the element-by-element approach (finite array approach) of Pozar (1986) and Smolders (1992); and (2) the infinite approach of Pozar and Shaubert (1984) and Liu et al. (1988). Both theories were found to give almost the same results for a 7 x 7 stacked microstrip antenna, except for edge array elements and for large scan angles. Edge array elements could only be analyzed properly by using a finite array approach. Coupling measurements were made on a 7 x 7 array with a single patch layer, and the results agreed well with calculations.

Arts, M. J.; Smolders, A. B.

1993-06-01

371

Color considerations in fluorescent solar concentrator stacks  

NASA Astrophysics Data System (ADS)

We present modeled results of the luminous and color outputs of a three-layer stack of fluorescent planar concentrators (FPCs). FPCs have the potential to provide sufficient luminous output to illuminate moderate-sized rooms for reasonably-sized collecting areas. It is of course necessary not only that the lumens be sufficient, but also that the light be sufficiently white as to be comfortable. Modeling shows that by use of a stack of three FPCs, one each of violet, green, and red, it is possible to achieve good color rendering and sufficient lighting levels for room illumination.

Swift, Paul D.; Smith, Geoff B.

2003-09-01

372

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

373

Improved particulate-sampling filter  

NASA Technical Reports Server (NTRS)

Small surface indentations entrain larger and more representative sampling than conventional petri-dish smeared with smooth layer adhesive. Filter is assembled from perforated disk and flat backing plate with sticky surface. Due to design-created currents, particulates come in contact with surface for longer time and have greater probability of being trapped. Filter is useful in air-quality monitoring at industrial sites, in mines, and in and around nuclear power plants.

Hoffman, A. R.; Schneider, H. W.

1980-01-01

374

Quasicrystalline particulate reinforced aluminum composite  

SciTech Connect

Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

1997-07-01

375

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

376

Proceedings: Eighth particulate control symposium  

SciTech Connect

The Eighth Symposium on the Transfer and Utilization of Particulate Control Technology was held in San Diego, California, March 20 through 23, 1990. The symposium proceedings contain 80 papers presented by representatives of utility companies, equipment and process suppliers, university representatives, research and development companies, EPA and other federal and state agency representatives, and EPRI staff members. Papers from this conference are organized by session in two volumes as follows: Volume 1 contains papers presented in the sessions on: precipitator controls, innovative pollution control technologies, precipitator modeling, fly ash/ESP studies, ESP plate spacing, ESP rapping, ESP performance upgrading and hot-side precipitator studies. Except for papers on corona destruction of pollutants in the innovative pollution control technology sessions, these papers are all concerned with ESP technology. Volume 2 contains papers presented in the sessions on: low ratio baghouse O M experience, pulse-jet baghouse experience, particulate control for AFBCs, particulate control for dry SO{sub 2} control processes, baghouse design and performance, fundamental baghouse studies, high temperature filtration, and control of emissions from RDF incinerators. Individual projects are processed separately for the data bases.

Not Available

1990-11-01

377

Particulate-phase and gaseous elemental mercury emissions during biomass combustion: controlling factors and correlation with particulate matter emissions.  

PubMed

Mercury emissions from wildfires are significant natural sources of atmospheric mercury, but little is known about what controls speciation of emissions important to mercury deposition processes. The goal of this study was to quantify gaseous elemental mercury (GEM) and particulate-phase mercury (PHg) emissions from biomass combustion to identify key factors controlling the speciation. Emissions were characterized in an exhaust stack 17 m above fires using a gaseous mercury analyzer and quartz-fiber filters. Fuels included fresh and air-dried leaves, needles, and branches with different fuel moistures (9-95% of dry weight) and combustion properties (e.g., from < 10 to 90% of fire durations characterized by flaming phases). Fuel moisture was the overall driving factor defining emissions, with GEM being the dominant fraction (> or = 95%) in low moisture fuels and substantial PHg contributions--up to 50% of total mercury emissions--in fresh fuels. High PHg emissions were observed during smoldering combustion whereas flaming-dominated fires showed insignificant PHg emissions. PHg mass emissions were correlated with particulate matter (PM; r2 = 0.67), organic carbon (OC; r2 = 0.63) and sulfur (S; r2 = 0.46) mass emissions, but not with elemental carbon (EC) nor with the total mercury emissions. These data suggest that the formation of PHg involves similar processes as the formation of particulate OC, for example condensation of volatile species onto preexisting smoke particles during cooling and dilution. Based on the observed relationship between PM and OC mass concentrations and published emission inventories, we estimate global PHg emissions by wildfires of 4-5 Mg yr(-1). PMID:18323093

Obrist, Daniel; Moosmüller, Hans; Schürmann, Roger; Chen, L W Antony; Kreidenweis, Sonia M

2008-02-01

378

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

379

Arrays of stacked metal coordination compounds  

DOEpatents

A process is disclosed for preparing novel arrays of metal coordination compounds characterized by arrangement of the metal ions, separated by a linking agent, in stacked order one above the other. The process permits great flexibility in the design of the array. For example, layers of different composition can be added to the array at will.

Bulkowski, John E. (Newark, DE)

1986-01-01

380

Structural Relaxation of Stacked Ultrathin Polystyrene Films  

NASA Astrophysics Data System (ADS)

The kinetic behavior of stacked polystyrene ultrathin films is investigated by differential scanning calorimetry (DSC) and compared to the behavior of bulk polystyrene. The fictive temperature (Tf) was measured as a function of cooling rate and as a function of aging time for aging temperatures below the nominal glass transition temperature (Tg). The stacked thin films show enthalpy overshoots in DSC heating scans which are reduced in height but occur over a broader temperature range relative to the bulk response for a given change in fictive temperature. The cooling rate dependence of the limiting fictive temperature, Tf' is also found to be higher for the stacked thin film samples; the result is that the magnitude of the Tg depression between the thin film sample and the bulk is inversely proportional to the cooling rate consistent with other results in the literature. We also find that the rate of physical aging of the stacked thin films is comparable to the bulk when aging is performed at the same distance from Tg; however, when conducted at the same aging temperature, the thin film samples show accelerated physical aging due to their depressed Tg values. This result is in contrast to recent work in the literature on PMMA ultrathin films and on o-TP confined in nanopores.

Koh, Yung P.; Simon, Sindee L.

2008-03-01

381

49 CFR 178.980 - Stacking test.  

Code of Federal Regulations, 2010 CFR

...the load to be placed on the Large Packaging must be 1.8 times...permissible gross mass of the number of similar Large Packaging that may be stacked...load in pounds. n = maximum number of Large Packagings that may be...

2010-10-01

382

Removing Sulphur Dioxide From Stack Gases  

ERIC Educational Resources Information Center

Process types, process concepts, claims and counterclaims, cost factors, and the level of developed technology for sulfur dioxide control in stack gases are focused upon and evaluated. Wet and dry processes as well as recovery and throwaway processes are compared. (BL)

Slack, A. V.

1973-01-01

383

Somatic Cell Cloning in Polyester Stacks  

Microsoft Academic Search

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four high-resolution colony

Christian R. H. Raetz; Mary M. Wermuth; Thomas M. McIntyre; Jeffrey D. Esko; Debra C. Wing

1982-01-01

384

Development of mechanically stacked tandem concentrator cells  

SciTech Connect

Mechanically stacked, multijunction (MSMJ) solar cells offer an excellent prospect for significantly increased efficiencies in the near term. In this work, we examine several new concepts for a MSMJ solar cell. These MSMJ cell concepts include the following: A GaAsP cell grown on a GaP substrate for stacking onto a silicon cell; a GaSb cell grown lattice-matched on a GaSb substrate for stacking beneath a GaAs cell; and a Ge cell for stacking beneath a GaAs cell. The growth of GaAsP and of GaSb by vacuum chemical epitaxy and the development of GaSb solar cells are described. The development of a germanium solar cell and of a 26.1% GaAs/Ge MSMJ cell is also described. Finally, this work has identified approaches for achieving efficiencies with a MSMJ cell in excess of 30%. 19 refs., 18 figs., 7 tabs.

Cape, J.A.; Fraas, L.M.; McLeod, P.S.; Partain, L.D.

1987-10-01

385

Pin stack array for thermoacoustic energy conversion  

Microsoft Academic Search

A thermoacoustic stack for connecting two heat exchangers in a thermoacoustic energy converter provides a convex fluid-solid interface in a plane perpendicular to an axis for acoustic oscillation of fluid between the two heat exchangers. The convex surfaces increase the ratio of the fluid volume in the effective thermoacoustic volume that is displaced from the convex surface to the fluid

Robert M. Keolian; Gregory W. Swift

1995-01-01

386

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

387

Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Fifth quarterly project report, April 1982-June 1982. [Concentration of Na and K in gas at process conditions; also optimization of removal system  

SciTech Connect

This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a comprehensive plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report briefly summarizes efforts previously completed on thermodynamic projections and system performance projections, together with current work on getter selection and qualification completed during the fifth quarter of the project. Work on the thermodynamic projections has been completed and includes an update of the data base, development of alkali phase diagrams, and projections for several gasification processes. Getter selection and qualification efforts involved four tests - two with activated bauxite and one each with diatomaceous earth and Novacite on the thermogravimetric analysis (TGA) system. Finally, system performance projections entailed examination of available kinetic data to ascertain the rate-controlling step, along with modeling efforts to determine the size requirements of a commercial-sized unit.

Mulik, P.R.; Alvin, M.A.; Bachovchin, D.M.

1982-07-01

388

Stacking optimization of compressor blades of gas turbine engines  

NASA Technical Reports Server (NTRS)

A procedure is presented to obtain optimal designs of axial compressor blades with structural design constraints. Coefficients of the polynomials defining the circumferential tilting angles and the axial leaning distances of the airfoil cross sections from the initial design geometry are used as design variables. The compressor blades are modeled by 20-node solid elements. An efficient finite element method is developed for modal analysis and sensitivity analysis with respect to the design variables. Based on this information, a sequential linear programming method is applied to calculate the required change of geometry for the desired structural design constraints.

Cheu, Tsu-Chien

1990-01-01

389

Assessment of hot particulate removal systems for IGCC and PFBC advanced power systems  

SciTech Connect

The National Research Council (NRC) Committee on the Strategic Assessment of the DOE Coal Program addressed the future role of DOE in research, development, demonstration, (RD and D) and commercial application programs on coal-based technologies. Parsons Power Group Inc. assisted DOE in assessing expected results of hot gas cleanup systems RD and D for advanced IGCC and PFBC. The technical approach to conducting the assessment consisted of three parts: determination of hot gas cleanup status, determination of hot gas cleanup systems cost and performance sensitivities, and the identification of DOE`s specific goals, stages and time frames. The hot gas cleanup technologies were divided into three categories, particulate collection systems, hot gas desulfurization systems, and trace contaminants removal systems. This presentation covers the assessment of the particulate removal systems. Information was obtained from a literature review, a phone survey of selected key people, and the Parsons Power Information base. Significant tests and results were summarized and development progress noted. To determine the sensitivity of particulate cleanup devices on overall system costs and performance, existing IGCC and PFBC plant designs with hot gas cleanup were used as baselines for analysis. The status of particulate removal system development relative to program goals were compared against testing results, cost/benefits and alternative technologies, and an assessment were made as to the time frame for commercialization. Findings of the assessment will be presented.

Klett, M.G.; Rutkowski, M.D.; Zaharchuk, R. [Parsons Power Group Inc., Reading, PA (United States)

1996-12-31

390

FEASIBILITY OF A STACK INTEGRATED SOFC OPTICAL CHEMICAL SENSOR  

SciTech Connect

The work performed during the UCR Innovative Concepts phase I program was designed to demonstrate the chemical sensing capabilities of nano-cermet SPR bands at solid oxide fuel cell operating conditions. Key to this proposal is that the materials choice used a YSZ ceramic matrix which upon successful demonstration of this concept, will allow integration directly onto the SOFC stack. Under the Innovative Concepts Program the University at Albany Institute for Materials (UAIM)/UAlbany School of NanoSciences and NanoEngineering synthesized, analyzed and tested Pa, and Au doped YSZ nano-cermets as a function of operating temperature and target gas exposure (hydrogen, carbon monoxide and 1-dodecanethiol). During the aforementioned testing procedure the optical characteristics of the nano-cermets were monitored to determine the sensor selectivity and sensitivity.

Michael A. Carpenter

2004-03-30

391

MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). 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 emission 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; Grant E. Dunham; Michelle R. Olderbak

2002-02-01

392

Solutions to RealWorld Instances of PSPACEComplete Stacking  

E-print Network

planning and sorting with networks of stacks. The Towers of Hanoi puzzle is just a very simple instance sequence. In between, slabs are brought by cranes to a storage area where they are piled up on stacks (for

Nabben, Reinhard

393

VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO ...  

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

VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO THE FAR RIGHT. WAREHOUSE WITH ITS RIDGELINE ROTARY VENTS TO RIGHT OF STACK. VIEW FROM THE WEST - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

394

Project W-420 Stack Monitoring system upgrades conceptual design report  

SciTech Connect

This document describes the scope, justification, conceptual design, and performance of Project W-420 stack monitoring system upgrades on six NESHAP-designated, Hanford Tank Farms ventilation exhaust stacks.

TUCK, J.A.

1998-11-06

395

40 CFR 62.14412 - What stack opacity requirements apply?  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false What stack opacity requirements apply? 62.14412 Section...Emission Limits § 62.14412 What stack opacity requirements apply? Your HMIWI...gases that exhibit greater than 10 percent opacity (6-minute block...

2012-07-01

396

40 CFR 62.14412 - What stack opacity requirements apply?  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false What stack opacity requirements apply? 62.14412 Section...Emission Limits § 62.14412 What stack opacity requirements apply? Your HMIWI...gases that exhibit greater than 10 percent opacity (6-minute block...

2010-07-01

397

40 CFR 62.14412 - What stack opacity requirements apply?  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false What stack opacity requirements apply? 62.14412 Section...Emission Limits § 62.14412 What stack opacity requirements apply? Your HMIWI...gases that exhibit greater than 10 percent opacity (6-minute block...

2011-07-01

398

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

399

Preventing Molecular and Particulate Infiltration in a Confined Volume  

NASA Technical Reports Server (NTRS)

Contaminants from an instrument's self-generated sources or from sources external to the instrument may degrade its critical surfaces and/or create an environment which limits the instrument's intended performance. Analyses have been carried out on a method to investigate the required purging flow of clean, dry gas to prevent the ingestion of external contaminants into the instrument container volume. The pressure to be maintained and the required flow are examined in terms of their effectiveness in preventing gaseous and particulate contaminant ingestion and abatement of self-generated contaminants in the volume. The required venting area or the existing volume venting area is correlated to the volume to be purged, the allowable pressure differential across the volume, the external contaminant partial pressure, and the sizes of the ambient particulates. The diffusion of external water vapor into the volume while it was being purged was experimentally obtained in terms of an infiltration time constant. That data and the acceptable fraction of the outside pressure into the volume indicate the required flow of purge gas expressed in terms of volume change per unit time. The exclusion of particulates is based on the incoming velocity of the particles and the exit flow speed and density of the purge gas. The purging flow pressures needed to maintain the required flows through the vent passages are indicated. The purge gas must prevent or limit the entrance of the external contaminants to the critical locations of the instrument. It should also prevent self- contamination from surfaces, reduce material outgassing, and sweep out the outgassed products. Systems and facilities that can benefit from purging may be optical equipment, clinical facilities, manufacturing facilities, clean rooms, and other systems requiring clean environments.

Scialdone, John J.

1999-01-01

400

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

401

Comparative analysis between the alveolar recruitment maneuver and breath stacking technique in patients with acute lung injury  

PubMed Central

Objective To compare the effectiveness of the alveolar recruitment maneuver and the breath stacking technique with respect to lung mechanics and gas exchange in patients with acute lung injury. Methods Thirty patients were distributed into two groups: Group 1 - breath stacking; and Group 2 - alveolar recruitment maneuver. After undergoing conventional physical therapy, all patients received both treatments with an interval of 1 day between them. In the first group, the breath stacking technique was used initially, and subsequently, the alveolar recruitment maneuver was applied. Group 2 patients were initially subjected to alveolar recruitment, followed by the breath stacking technique. Measurements of lung compliance and airway resistance were evaluated before and after the use of both techniques. Gas analyses were collected before and after the techniques were used to evaluate oxygenation and gas exchange. Results Both groups had a significant increase in static compliance after breath stacking (p=0.021) and alveolar recruitment (p=0.03), but with no significant differences between the groups (p=0.95). The dynamic compliance did not increase for the breath stacking (p=0.22) and alveolar recruitment (p=0.074) groups, with no significant difference between the groups (p=0.11). The airway resistance did not decrease for either groups, i.e., breath stacking (p=0.91) and alveolar recruitment (p=0.82), with no significant difference between the groups (p=0.39). The partial pressure of oxygen increased significantly after breath stacking (p=0.013) and alveolar recruitment (p=0.04), but there was no significant difference between the groups (p=0.073). The alveolar-arterial O2 difference decreased for both groups after the breath stacking (p=0.025) and alveolar recruitment (p=0.03) interventions, and there was no significant difference between the groups (p=0.81). Conclusion Our data suggest that the breath stacking and alveolar recruitment techniques are effective in improving the lung mechanics and gas exchange in patients with acute lung injury. PMID:25028951

Porto, Elias Ferreira; Tavolaro, Kelly Cristiani; Kumpel, Claudia; Oliveira, Fernanda Augusta; Sousa, Juciaria Ferreira; de Carvalho, Graciele Vieira; de Castro, Antonio Adolfo Mattos

2014-01-01

402

Spatial and temporal distributions of particulate matter and particulate organic carbon, Northeast Gulf of Mexico  

E-print Network

The distribution of particulate matter (PM) and particulate organic carbon (POC) was determined during the Northeast Gulf of Mexico Chemical Oceanography and Hydro-graphy program (NEGOM). The hydrography and physical forcing functions were examined...

Bernal, Christina Estefana

2012-06-07

403

Recent Results of Stack Development at Forschungszentrum Jülich  

Microsoft Academic Search

Since the mid-nineties several generations of SOFC stacks have been designed and tested incorporating the anode substrate-type cells developed in Jülich. The 6th generation, the so-called F-design stacks, with metallic interconnect has been the ‘work horse’ used for testing materials, cells and manufacturing processes in cell and stack development since its introduction in the year 2001. Stacks with up to

R. Steinberger-Wilckens; L. G. J. Haart; I. C. Vinke; L. Blum; A. Cramer; J. Remmel; G. Blass; F. Tietz; W. J. Quadakkers

404

Twin-stack decoding of recursive systematic convolutional codes  

Microsoft Academic Search

We present a method for soft-in\\/soft-out sequential decoding of recursive systematic convolutional codes. The proposed decoder, the twin-stack decoder, is an extension of the well-known ZJ stack decoder, and it uses two stacks. The use of the two stacks lends itself to the generation of soft outputs, and the decoder is easily incorporated into the iterative “turbo” configuration. Under thresholded

Ravi Sivasankaran; Steven W. McLaughlin

2001-01-01

405

Stacking of six-membered aromatic rings in crystals  

NASA Astrophysics Data System (ADS)

Geometrical preferences of stacking and the possibilities and limitations of using stacking in designing crystal structures have been analyzed, based on the crystal structures of benzenes, pyridines and s-triazines. It is shown that crystallographic symmetry imposes severe restrictions on stacking parameters and that alteration of the ?-electron distribution in the aromatic ring by incorporation of heteroatom(s) significantly increases the possibility of stacking.

G?ówka, M. L.; Martynowski, D.; Koz?owska, K.

1999-01-01

406

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

407

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

408

Measurement of Particulate Pollutants in the Atmosphere  

NASA Technical Reports Server (NTRS)

Representative measurements of the mass concentration of particulate matter in the atmosphere are presented, to demonstrate the application of a new type of instrument evolved from aerospace research to various types of particulate pollution and their dynamics. The instrument employs aerodynamic impaction of particles onto an adhesive-coated piezo-electric crystal whose resonant frequency decreases with mass accretion on its surface, with a resulting particulate mass resolution of 10(exp -11) gram. Applications include air basin with aerial measurement of particulate mass concentration, jet aircraft wake, stationary industrial sources, direct on-line measurement of automobile exhaust, and techniques for source detection.

Ckuan, Raymond L.

1971-01-01

409

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

410

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

411

Size distribution and chemical composition of metalliferous stack emissions in the San Roque petroleum refinery complex, southern Spain.  

PubMed

We demonstrate that there is great variation in the size range and chemical composition of metalliferous particulate matter (PM) present within petrochemical complex chimney stacks. Cascade impactor PM samples from seven size ranges (17, 14, 5, 2.5, 1.3, 0.67, and 0.33 ?m) were collected from inside stacks within the San Roque complex which includes the largest oil refinery in Spain. SEM analysis demonstrates the PM to be mostly carbonaceous and aluminous fly ash and abundant fine metalliferous particles. The metals with the most extreme concentrations averaged over all size ranges were Ni (up to 3295 ?g m(-3)), Cr (962 ?g m(-3)), V (638 ?g m(-3)), Zn (225 ?g m(-3)), Mo (91 ?g m(-3)), La (865 ?g m(-3)), and Co (94 ?g m(-3)). Most metal PM are strongly concentrated into the finest fraction (<0.33 ?m), although emissions from some processes, such as purified terephthallic acid (PTA) production, show coarser size ranges. The fluid catalytic cracking stack shows high concentrations of La (>200 ?g m(-3) in PM(0.67-1.3)), Cr and Ni in a relatively coarse PM size range (0.7-14 ?m). Our unique database, directly sampled from chimney stacks, confirms that oil refinery complexes such as San Roque are a potent source of a variety of fine, deeply inhalable metalliferous atmospheric PM emissions. PMID:21514727

de la Campa, A M Sánchez; Moreno, T; de la Rosa, J; Alastuey, A; Querol, X

2011-06-15

412

Communications protocol stacks for the Space Station Freedom  

Microsoft Academic Search

Some of the aspects of the communications protocol stacks that have been recommended for the packet communications services for the Space Station Freedom Program are discussed. Particular attention is given to the protocol stacks that support the two space-to-ground packet communications services, the path and internet services. The protocol stacks of the subnetworks and gateways that connect onboard and ground

D. Quincey; J. F. Smith

1990-01-01

413

Meta-Learning for Stacked Classi cation Alexander K. Seewald  

E-print Network

Meta-Learning for Stacked Classi cation Alexander K. Seewald Austrian Research Institute for Arti in these experiments was whether meta-learning methods can be used to accurately predict various aspects of Stacking can lead to new insights into Stacking's behaviour. 1 Introduction Meta-learning focusses

Bohanec, Marko

414

Second law analysis of porous thermoacoustic stack systems  

Microsoft Academic Search

The objective of this paper is to analyze the irreversibility of the porous thermoacoustic stacks in terms of entropy generation. Thermoacoustic stacks are modeled in this paper as porous channels having wall with finite thickness. The flow field in the porous channel is described by the Darcy momentum equation. The thermal field inside the porous stack is modeled by volume

Syeda Humaira Tasnim; Shohel Mahmud; Roydon Andrew Fraser

2011-01-01

415

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

416

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

417

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

418

40 CFR 52.2085 - Stack height review.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 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...

2012-07-01

419

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

420

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

421

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

422

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

423

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

424

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

425

40 CFR 52.1532 - Stack height review.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Stack height review. 52.1532 Section 52.1532... New Hampshire § 52.1532 Stack height review. The State of New Hampshire...limitations have been affected by stack height credits greater than good...

2012-07-01

426

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

427

40 CFR 52.2180 - Stack height regulations.  

...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

428

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

429

40 CFR 52.1532 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.1532 Section 52.1532... New Hampshire § 52.1532 Stack height review. The State of New Hampshire...limitations have been affected by stack height credits greater than good...

2013-07-01

430

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

431

40 CFR 52.1832 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 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...

2013-07-01

432

40 CFR 52.383 - Stack height review.  

...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

433

40 CFR 51.164 - Stack height procedures.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 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...

2012-07-01

434

40 CFR 52.2534 - Stack height review.  

...2014-07-01 2014-07-01 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...

2014-07-01

435

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

436

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

437

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

438

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

439

40 CFR 52.2085 - Stack height review.  

...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

440

40 CFR 52.2633 - Stack height regulations.  

...2014-07-01 2014-07-01 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...

2014-07-01

441

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

442

40 CFR 52.2633 - Stack height regulations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 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...

2013-07-01

443

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

444

40 CFR 52.2384 - Stack height review.  

...2014-07-01 2014-07-01 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...

2014-07-01

445

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

446

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

447

40 CFR 52.2180 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 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...

2012-07-01

448

40 CFR 52.1832 - Stack height regulations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 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...

2012-07-01

449

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

450

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

451

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

452

40 CFR 51.164 - Stack height procedures.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

453

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

454

40 CFR 52.1532 - Stack height review.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Stack height review. 52.1532 Section 52.1532... New Hampshire § 52.1532 Stack height review. The State of New Hampshire...limitations have been affected by stack height credits greater than good...

2011-07-01

455

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

456

40 CFR 52.1532 - Stack height review.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Stack height review. 52.1532 Section 52.1532... New Hampshire § 52.1532 Stack height review. The State of New Hampshire...limitations have been affected by stack height credits greater than good...

2010-07-01

457

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

458

40 CFR 52.2633 - Stack height regulations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

459

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

460

Characterization of polycyclic aromatic hydrocarbon particulate and gaseous emissions from polystyrene combustion  

SciTech Connect

The partitioning of polycyclic aromatic hydrocarbons (PAHs) between the particulate and gaseous phases resulting from the combustion of polystyrene was studied. A vertical tubular flow furnace was used to incinerate polystyrene spheres at different combustion temperatures to determine the effect of temperature and polystyrene feed size on the particulate and gaseous emissions and their chemical composition. The furnace reactor exhaust was sampled using real-time instruments (differential mobility particle sizer and/or optical particle counter) to determine the particle size distribution. For chemical composition analyses, the particles were either collected on Teflon filters or split into eight size fractions using a cascade impactor with filter media substrates, while the gaseous products were collected on XAD-2 adsorbent. Gas chromatography/mass spectroscopy was used to identify and quantify the specific PAH species, their partitioning between the gas and particulate phases, and their distribution as a function of emission particle size. The total mass and number of PAH species in both the particulate and gas phases were found to decrease with increasing incineration temperature and decreasing polystyrene feed size, while the mean diameter of the particles increases with increasing incineration temperature and decreasing feed size. In addition, the PAH species in the particulate phase were found to be concentrated in the smaller aerosol sizes.

Durlak, S.K.; Biswas, P. [Univ. of Cincinnati, OH (United States)] [Univ. of Cincinnati, OH (United States); Shi, J.; Bernhard, M.J. [Procter and Gamble, Cincinnati, OH (United States). Environmental Science Dept.] [Procter and Gamble, Cincinnati, OH (United States). Environmental Science Dept.

1998-08-01

461

40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.  

...2014-07-01 false Determination of NOX mass emissions for common stack and multiple... CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions § 75.72 Determination of NOX mass emissions for common stack and...

2014-07-01

462

Process for 3D chip stacking  

DOEpatents

A manufacturable process for fabricating electrical interconnects which extend from a top surface of an integrated circuit chip to a sidewall of the chip using laser pantography to pattern three dimensional interconnects. The electrical interconnects may be of an L-connect or L-shaped type. The process implements three dimensional (3D) stacking by moving the conventional bond or interface pads on a chip to the sidewall of the chip. Implementation of the process includes: (1) holding individual chips for batch processing, (2) depositing a dielectric passivation layer on the top and sidewalls of the chips, (3) opening vias in the dielectric, (4) forming the interconnects by laser pantography, and (5) removing the chips from the holding means. The process enables low cost manufacturing of chips with bond pads on the sidewalls, which enables stacking for increased performance, reduced space, and higher functional per unit volume. 3 figs.

Malba, V.

1998-11-10

463

Process for 3D chip stacking  

DOEpatents

A manufacturable process for fabricating electrical interconnects which extend from a top surface of an integrated circuit chip to a sidewall of the chip using laser pantography to pattern three dimensional interconnects. The electrical interconnects may be of an L-connect or L-shaped type. The process implements three dimensional (3D) stacking by moving the conventional bond or interface pads on a chip to the sidewall of the chip. Implementation of the process includes: 1) holding individual chips for batch processing, 2) depositing a dielectric passivation layer on the top and sidewalls of the chips, 3) opening vias in the dielectric, 4) forming the interconnects by laser pantography, and 5) removing the chips from the holding means. The process enables low cost manufacturing of chips with bond pads on the sidewalls, which enables stacking for increased performance, reduced space, and higher functional per unit volume.

Malba, Vincent (Livermore, CA)

1998-01-01

464

Automated krypton-85 gamma ray stack monitor  

SciTech Connect

A Ge(Li) ..gamma..-ray detector, housed in a lead cave, was used in conjunction with a six-liter pressurized (60 psia) well spectroscopy cell to selectively detect /sup 85/Kr stack emissions. This system was calibrated so as to relate the 514 keV ..gamma..-ray counting rate to /sup 85/Kr concentration. Counting rate, or concentration, was continuously recorded using a count rate meter/strip chart recorder combination and was also time averaged over 15 minute intervals using a programmable multi-channel analyzer system with cassette readout. Being completely automated, this ..gamma..-analysis system required little more than liquid nitrogen service and data record retrieval throughout a four-month long sampling period. The sensitivity of this ..gamma..-ray analytical system was such as to achieve a minimum detectable /sup 85/Kr stack concentration of 2 ..mu..Ci/m/sup 3/ for 15 minute counting intervals.

Goles, R.W.; Brauer, F.P.

1980-09-01

465

Using wafer stacks as neutron monochromators  

NASA Astrophysics Data System (ADS)

A process to introduce a spatially homogeneous but anisotropic mosaic structure into thin, single-crystal wafers, which are then stacked and used as neutron monochromators, is described. The advantages compared to conventional techniques are good reproduceability, low cost and reduced risk of process failure. A focusing Ge(115) monochromator made from 24 wafer stacks was built for the high-resolution neutron powder diffractometer at the High Flux Beam Reactor at Brookhaven National Laboratory. Besides building "classical" monochromators for elastic neutron scattering experiments, individual wafers with a given peak reflectivity can be tilted with respect to each other to increase the reflected wavelength band ??/?. Such "fanned" arrays present a competitive alternative to monochromators using highly-oriented pyrolitic graphite (HOPG).

Vogt, T.; Passell, L.; Cheung, S.; Axe, J. D.

1994-01-01

466

Stacking boundaries and transport in bilayer graphene.  

PubMed

Pristine bilayer graphene behaves in some instances as an insulator with a transport gap of a few millielectronvolts. This behavior has been interpreted as the result of an intrinsic electronic instability induced by many-body correlations. Intriguingly, however, some samples of similar mobility exhibit good metallic properties with a minimal conductivity of the order of 2e(2)/h. Here, we propose an explanation for this dichotomy, which is unrelated to electron interactions and based instead on the reversible formation of boundaries between stacking domains ("solitons"). We argue, using a numerical analysis, that the hallmark features of the previously inferred many-body insulating state can be explained by scattering on boundaries between domains with different stacking order (AB and BA). We furthermore present experimental evidence, reinforcing our interpretation, of reversible switching between a metallic and an insulating regime in suspended bilayers when subjected to thermal cycling or high current annealing. PMID:24605877

San-Jose, P; Gorbachev, R V; Geim, A K; Novoselov, K S; Guinea, F

2014-04-01

467

Learning algorithms for stack filter classifiers  

SciTech Connect

Stack Filters define a large class of increasing filter that is used widely in image and signal processing. The motivations for using an increasing filter instead of an unconstrained filter have been described as: (1) fast and efficient implementation, (2) the relationship to mathematical morphology and (3) more precise estimation with finite sample data. This last motivation is related to methods developed in machine learning and the relationship was explored in an earlier paper. In this paper we investigate this relationship by applying Stack Filters directly to classification problems. This provides a new perspective on how monotonicity constraints can help control estimation and approximation errors, and also suggests several new learning algorithms for Boolean function classifiers when they are applied to real-valued inputs.

Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory; Zimmer, Beate G [TEXAS A& M

2009-01-01

468

Radiation-Tolerant Intelligent Memory Stack - RTIMS  

NASA Technical Reports Server (NTRS)

This innovation provides reconfigurable circuitry and 2-Gb of error-corrected or 1-Gb of triple-redundant digital memory in a small package. RTIMS uses 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 circuits are stacked into a module of 42.7 42.7 13 mm. Triple module redundancy, current limiting, configuration scrubbing, and single- event function interrupt detection are employed to mitigate radiation effects. The novel self-scrubbing and single event functional interrupt (SEFI) detection allows a relatively soft FPGA to become radiation tolerant without external scrubbing and monitoring hardware

Ng, Tak-kwong; Herath, Jeffrey A.

2011-01-01

469

Seasonal and diurnal variations of particulate nitrate and organic matter in the Central European atmospheric aerosol  

NASA Astrophysics Data System (ADS)

Nitrate and several organic compounds such as dicarboxylic acids (e.g. succinic acid, glutaric acid), Polycyclic Aromatic Hydrocarbons (PAHs) or n-alkanes form the group of the most volatile compounds in atmospheric aerosol particles. The transition of these compounds between gas and particulate phase may significantly change the aerosol particles radiative properties, the heterogeneous chemical properties, and, naturally, the total particulate mass concentration. To better assess these time-dependent effects, three intensive field experiments were conducted in 2008-2009 at the Central European EMEP research station Melpitz (Germany) using an Aerodyne Aerosol Mass Spectrometer (AMS). Data coverage from all seasons highlighted organic matter as being the most important particulate fraction during summertime, while the nitrate fraction was more prevalent in winter. The variation in particulate nitrate was inherently linked to the gas-to-particle-phase equilibrium of ammonium nitrate, which depends on ambient temperature and relative humidity. During short episodes immediately after dawn, the particulate nitrate seems to disobey this dependency so that additional local nitrate formation, such as from HONO photolysis is needed as an explanation. During the summer 2008's experiment, a remarkable diurnal evolution in the oxidation state of the organic matter became evident, which could be correlated to hydroxyl radical (OH) and ozone concentrations indicating photochemical transformation process. In summer, the organic particulate matter seems to be heavily influenced by regional secondary formation and transformation processes, facilitated by photochemical production processes as well as a diurnal cycling of the substances between the gas and particulate phase. In winter, these processes were obviously much weaker, so that organic matter apparently originated mainly from aged particles and long range transport.

Poulain, L.; Spindler, G.; Birmili, W.; Plass-Dülmer, C.; Wiedensohler, A.; Herrmann, H.

2011-04-01

470

A Network Protocol Stack in Standard ML  

Microsoft Academic Search

The FoxNet is an implementation of the standard TCP\\/IP networking protocol stack using the Standard ML (SML) language. SML is a type-safe programming lan- guage with garbage collection, a unique and advanced module system, and machine- independent semantics. The FoxNet is a user-space implementation of TCP\\/IP that is built in SML by composing modular protocol elements; each element independently implements

Edoardo Biagioni; Robert Harper; Peter Lee

2001-01-01

471

A Network Protocol Stack in Standard ML  

Microsoft Academic Search

The FoxNet is an implementation of the standard TCP\\/IP networking protocol stack using the Standard ML (SML) language. SML is a type-safe programming language with garbage collection, a unique and advanced module system, and machine-independent semantics. The FoxNet is a user-space implementation of TCP\\/IP that is built in SML by composing modular protocol elements; each element independently implements one of

Edoardo Biagioni; Robert Harper; Peter Lee

2001-01-01

472

Average transmission probability of a random stack  

E-print Network

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 bounds. The upper bound, when used as an approximation for the transmission probability, is unreasonably good and we conjecture that it is asymptotically exact.

Yin Lu; Christian Miniatura; Berthold-Georg Englert

2009-07-31

473

Materials for IT-SOFC stacks  

Microsoft Academic Search

A personal view is presented of developments over the period 1964–1999 that have gradually made possible the fabrication of IT-SOFC stacks operating at 500°C. Although conceptual IT-SOFC designs were available in the early 1960s, their implementation had to await a much better understanding of various topics including: selection of optimal dopant type and concentration for solid electrolytes; the influence of

2000-01-01

474

Stacked Switchable Element and Diode Combination  

DOEpatents

A device (10) comprises a semiconductor diode (12) and a switchable element (14) positioned in stacked adjacent relationship so that the semiconductor diode (12) and the switchable element (14) are electrically connected in series with one another. The switchable element (14) is switchable from a low-conductance state to a high-conductance state in response to the application of a forming voltage to the switchable element (14).

Branz, H. M.; Wang, Q.

2006-06-27

475

Satellite power using magnetically suspended flywheel stack  

NASA Technical Reports Server (NTRS)

Research activities with magnetically suspended flywheels are reported. The purpose of the effort is to critically examine and further the development of all the key technologies which impact the inertial energy storage system. The results presented discuss the concept of a magnetically suspended flywheel as it applies to a 500 Watt-hour energy storage system. The proposed system is currently under hardware development and is based upon two pancake magnetic bearings arranged in a vertical stack.

Kirk, James A.; Anand, Davinder K.

1987-01-01

476

Satellite power using magnetically suspended flywheel stack  

NASA Astrophysics Data System (ADS)

Research activities with magnetically suspended flywheels are reported. The purpose of the effort is to critically examine and further the development of all the key technologies which impact the inertial energy storage system. The results presented discuss the concept of a magnetically suspended flywheel as it applies to a 500 Watt-hour energy storage system. The proposed system is currently under hardware development and is based upon two pancake magnetic bearings arranged in a vertical stack.

Kirk, James A.; Anand, Davinder K.

1987-09-01

477

Extended Life PZT Stack Test Fixture  

NASA Technical Reports Server (NTRS)

Piezoelectric stacks are being sought to be used as actuators for precision positioning and deployment of mechanisms in future planetary missions. Beside the requirement for very high operation reliability, these actuators are required for operation at space environments that are considered harsh compared to normal terrestrial conditions.These environmental conditions include low and high temperatures and vacuum or high pressure. Additionally, the stacks are subjected to high stress and in some applications need to operate with a very long lifetime durability.Many of these requirements are beyond the current industry design margins for nominal terrestrial applications. In order to investigate some of the properties that will indicate the durability of such actuators and their limitations we have developed a new type of test fixture that can be easily integrated in various test chambers for simulating environmental conditions, can provide access for multiple measurements while being exposed to adjustable stress levels. We designed and built two test fixtures and these fixtures were made to be adjustable for testing stacks with different dimensions and can be easily used in small or large numbers. The properties that were measured using these fixtures include impedance, capacitance, dielectric loss factor, leakage current, displacement, breakdown voltage, and lifetime performance. The fixtures characteristics and the test capabilities are presented in this paper.

Badescu, Mircea; Sherrit, S.; Bao, X.; Aldrich, J.; Bar-Cohen, Y.; Jones, C.

2009-01-01

478

Somatic cell cloning in polyester stacks.  

PubMed Central

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four-high resolution colony copies can be generated from a single master dish. The colonies on the cloth can be analyzed by radiochemical methods [Esko, J. D. & Raetz, C. R. H. (1978) Proc. Natl. Acad. Sci. USA 75, 1190-1193] or by "replica plating" to a new disc. The use of polyester cloth, singly or in stacks, has several major advantages over previous techniques for somatic cell replica plating, including: (i) broad applicability to diverse cell lines such as fragile membrane mutants of Chinese hamster ovary cells and relatively nonadherent myelomas or hybridomas; (ii) the possibility of generating multiple copies of the same colony population, allowing simultaneous analysis for several enzymes or cellular components; and (iii) superior resolution and transfer efficiency in copying colony patterns from one surface to another. The remarkable capacity of animal cell colonies to proliferate upward through "polyester stacks" may reflect chemotropic movement of individual cells and opens new approaches to somatic cell genetics. Images PMID:6954474

Raetz, C R; Wermuth, M M; McIntyre, T M; Esko, J D; Wing, D C

1982-01-01

479

Thyristor stack for pulsed inductive plasma generation.  

PubMed

A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 micros and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/micros. PMID:19334940

Teske, C; Jacoby, J; Schweizer, W; Wiechula, J

2009-03-01

480

Thyristor stack for pulsed inductive plasma generation  

SciTech Connect

A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 {mu}s and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/{mu}s.

Teske, C.; Jacoby, J.; Schweizer, W.; Wiechula, J. [Plasmaphysics Group, Institute of Applied Physics, Johann-Wolfgang-Goethe University, 60438 Frankfurt am Main (Germany)

2009-03-15