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1

Cooler and particulate separator for an off-gas stack  

DOEpatents

An off-gas stack for a melter 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 pervents 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, George T. (15 Cherry Hills Dr., Aiken, SC 29803) [15 Cherry Hills Dr., Aiken, SC 29803

1992-01-01

2

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 ...

3

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

4

200 Areas stack gas conference  

Microsoft Academic Search

A meeting was held at 9:30 A.M., January 20, 1949 in the 703 Building Conference Room in order to review the present status and subsequent plans of the 200 Areas stack gas problem with C.E. Lapple of the DuPont Company. Process ventilation air and dissolver off-gases were discussed.

Stainken

1949-01-01

5

Boiler Stack Gas Heat Recovery.  

National Technical Information Service (NTIS)

This report is a detailed study of various heat recovery schemes for Navy shore facilities to use otherwise lost stack heat. The waste heat can be used alternatively to improve the boiler efficiency through feedwater and/or combustion-air preheating, or t...

P. C. Lu T. T. Fu S. C. Garg G. Nowakowski

1987-01-01

6

Study of Laser Backscatter by Particulates in Stack Emissions.  

National Technical Information Service (NTIS)

The validity of determining smoke plume opacity or particulate content from measurements of the backscatter of laser radiation from plume particulates was investigated. The backscatter experiments were conducted with the use of a specially designed aeroso...

E. E. Uthe C. E. Lapple

1972-01-01

7

A new method for the characterisation and quantitative speciation of base metal smelter stack particulates.  

PubMed

Base metal smelters may be a source of particulates containing metals of environmental concern released to the atmosphere. Knowledge of the quantitative chemical speciation of particulate releases from base metal smelters will be of value in smelter emission fingerprinting, site-specific risk assessments, predictions of the behaviour of smelter stack particulates released to the environment and in resolving liability issues related to current and historic releases. Accordingly, we have developed an innovative approach comprising bulk chemical analysis, a leaching procedure, X-ray diffraction analysis and scanning electron microscopy/electron probe microanalysis characterisation in a step-wise apportioning procedure to derive the quantitative speciation of particulate samples from the stacks of three copper smelters designated as A, B and C. For the A smelter stack particulates, the major calculated percentages were 29 CuSO(4), 20 ZnSO(4).H(2)O, 13 (Cu(0.94)Zn(0.06))(2)(AsO(4))(OH), 11 PbSO(4) and four As(2)O(3). For the B smelter stack particulates, the primary calculated percentages were 20 ZnSO(4).H(2)O, 20 PbSO(4), 12 CuSO(4) and nine As(2)O(3). Finally, we calculated that the C smelter stack particulates mostly comprised 34 ZnSO(4).H(2)O, 19 (Cu(0.84)Zn(0.16))(AsO(3)OH), 11 PbSO(4), 10 As(2)O(3) and nine Zn(3)(AsO(4))(2). Between 56% and 67% by weight of the smelter stack particulates, including the As, was soluble in water. For these and other operations, the data and approach may be useful in estimating metals partitioning among water, soil and sediment, as well as predictions of the effects of the stack particulates released to the environment. PMID:20676929

Skeaff, James M; Thibault, Yves; Hardy, David J

2011-06-01

8

Stack Gas Scrubber Makes the Grade  

ERIC Educational Resources Information Center

Describes a year long test of successful sulfur dioxide removal from stack gas with a calcium oxide slurry. Sludge disposal problems are discussed. Cost is estimated at 0.6 mill per kwh not including sludge removal. A flow diagram and equations are included. (GH)

Chemical and Engineering News, 1975

1975-01-01

9

WASTE GAS STACKS, CONTEXTUAL VIEW. ABOVEGROUND DUCTWORK LEADS TO ETR ...  

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

WASTE GAS STACKS, CONTEXTUAL VIEW. ABOVE-GROUND DUCTWORK LEADS TO ETR STACK. MTR STACK AT LEFT OF VIEW. CAMERA FACING NORTH. INL NEGATIVE NO. HD42-7-1. Mike Crane, Photographer, 3/2004 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

10

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

NASA Astrophysics Data System (ADS)

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

Spang, Brent Loren

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

Simultaneous stack gas scrubbing wastewater purification  

NASA Technical Reports Server (NTRS)

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

1978-01-01

13

Process for off-gas particulate removal and apparatus therefor  

SciTech Connect

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

Independent determination of the accuracy of the OSTR stack gas monitor and its operational application  

SciTech Connect

This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As the argon-41 standard in the gas sample flask decayed, the concentration of the argon-41 was compared to the output of the Ge(Li)/MCA system. This established a calibration curve for the counting system, whereby a sample with an unknown concentration of argon-41 could be counted and the subsequent count rate from the sample converted to a concentration expressed in mCi per milliliter. Gas samples were extracted from various points in the reactor exhaust system and the concentrations of argon-41 were determined by counting on the Ge(Li)/MCA system. Each sample concentration was then compared to the argon-41 concentration indicated by the stack gas monitor. The initial results indicated that, although possibly intermittent, the argon-41 concentrations displayed by the stack gas monitor were often approximately 50% of those predicted by analysis of individual samples from the exhaust system. Several possible sources for the discrepancy were checked, including the method of SGM calibration, uneven mixing of exhaust air and argon-41 in the reactor building exhaust stream, and dilution of the gas concentration in the SGM system by air leakage into the system. After considerable effort, the latter cause was found to be the culprit, due to an aging gasket around the stack monitor's moving particulate-filter-paper housing.

Pickett, B.D. [Battelle-Pacific Northwest Laboratories, Richland, WA (United States); Johnson, A.G. [Oregon State University Radiation Center (United States)

1982-07-01

15

Particulate hot gas stream cleanup technical issues  

SciTech Connect

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

NONE

1998-09-01

16

Ceramic filters for removal of particulates from hot gas streams  

Microsoft Academic Search

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

1992-01-01

17

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...

18

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

19

Independent determination of the accuracy of a research reactor stack-gas monitor  

Microsoft Academic Search

During normal operation of the Oregon State University TRIGA reactor (OSTR), argon-41 is produced and released to the atmosphere as a gaseous effluent through the reactor building exhaust stack. The reactor facility's stack gas monitor (SGM) continuously samples the effluent in the exhaust stack and simultaneously measures the concentration of argon-41 being released. This study was undertaken to determine the

B. D. Pickett; A. G. Johnson

1981-01-01

20

CAPSULE REPORT: BAHCO FLUE GAS DESULFURIZATION AND PARTICULATE REMOVAL SYSTEM  

EPA Science Inventory

This capsule report describes a Research-Cottrell/Bahco scrubber module for sulfur dioxide and particulate emission control located at the central heat plant of Rickenbacker Air Force Base. he report also describes flue gas desulfurization technology using any fuel, including hig...

21

Senior High School Students' Mental Models of Mix-Gas in the Particulate Model of Ideal Gas  

Microsoft Academic Search

As research about the particulate nature of gas shows, students have many misconceptions about gas volume, gas pressure, and the spread of gas (Benson, Wittrock, & Baur, 1993; Chiu, in press). Our research focuses mainly on senior high school students' mental models and the consistency of conceptions about mix-gas in the particulate model of ideal gas. Our study is based

Shiao-Lan Chung; Mei-Hung Chiu

22

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

23

Workshop on Aerosols and Particulates from Aircraft Gas Turbine Engines  

NASA Technical Reports Server (NTRS)

In response to the National Research Council (NRC) recommendations, the Workshop on Aerosols and Particulates from Aircraft Gas Turbine Engines was organized by the NASA Lewis Research Center and held on July 29-30, 1997 at the Ohio Aerospace Institute in Cleveland, Ohio. The objective is to develop consensus among experts in the field of aerosols from gas turbine combustors and engines as to important issues and venues to be considered. Workshop participants' expertise included engine and aircraft design, combustion processes and kinetics, atmospheric science, fuels, and flight operations and instrumentation.

Wey, Chown Chou (Compiler)

1999-01-01

24

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

Code of Federal Regulations, 2010 CFR

...particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters...filters, methanol impingers and formaldehyde impingers. These...

2010-07-01

25

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

Code of Federal Regulations, 2010 CFR

...particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters...filters, methanol impingers and formaldehyde impingers. These...

2009-07-01

26

Stack gas emissions of PCDD\\/Fs from hospital waste incinerators in China  

Microsoft Academic Search

Stack gas samples from 14 domestic-made hospital waste incinerators (HWIs) in China were collected and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD\\/Fs). The waste burning capacities of the investigated HWIs ranged from 5 to 25tond?1. The stack gas emissions of PCDD\\/Fs from HWIs exhibited a large variation (0.08–31.60ng I-TEQNm?3). Nine incinerators had the emission levels below the current emission standard

Hongcai Gao; Yuwen Ni; Haijun Zhang; Liang Zhao; Ning Zhang; Xueping Zhang; Qing Zhang; Jiping Chen

2009-01-01

27

Results of a self-absorption study on the Versapor 3000 47-mm filters for radioactive particulate air stack sampling.  

PubMed

Since the mid-1980's the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor 3000, 47-mm diameter) used at PNNL for self absorption effects. 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. Large error is associated with the sample filter analysis comparison and subsequently with the estimation of the absorption factor resulting in an inadequate method to estimate losses from self-absorption in the sample filter. The mass loading on the sample filter as determined after digestion and drying was approximately 0.08 mg cm; however, this value may not represent the total filter mass loading given that there may be undetermined losses associated with the digestion process. While it is difficult to determine how much material is imbedded in the filter, observations from the microscopy analysis indicate that the vast majority of the particles remain on the top of the filter. In comparing the results obtained, the continued use of 0.85 as a conservative correction factor is recommended. PMID:19820471

Barnett, J M; Cullinan, V I; Barnett, D S; Trang-Le, T L T; Bliss, M; Greenwood, L R; Ballinger, M Y

2009-11-01

28

Effect of High-Pressure Inert Gas Annealing on AlON/Ge Gate Stacks  

NASA Astrophysics Data System (ADS)

We investigated germanium (Ge) metal--insulator--semiconductor (MIS) gate stacks with aluminum oxynitride (AlON) thin dielectric film. We found that high-pressure inert gas post deposition annealing (PDA) using N2 or Ar gas dramatically improved the electrical properties of AlON/Ge MIS gate stacks. The advantage of this process over high-pressure O2 oxidation or annealing, which produce excellent Ge gate stacks, is that no further interface layer growth in the N2 or Ar PDA is expected. We expect that thin AlON films combined with high-pressure inert gas PDA will provide a new way to achieve excellent Ge-MIS gate stacks with scalable equivalent oxide thickness.

Tabata, Toshiyuki; Nagashio, Kosuke; Toriumi, Akira

2012-09-01

29

Pressure and flow distribution in internal gas manifolds of a fuel-cell stack  

NASA Astrophysics Data System (ADS)

Gas-flow dynamics in internal gas manifolds of a fuel-cell stack are analyzed to investigate overall pressure variation and flow distribution. Different gas-flow patterns are considered in this analysis. Gas-flow through gas channels of each cell is modeled by means of Darcy's law where permeability should be determined on an experimental basis. Gas-flow in manifolds is modeled from the macroscopic mechanical energy balance with pressure-loss by wall friction and geometrical effects. A systematic algorithm to solve the proposed flow model is suggested to calculate pressure and flow distribution in fuel-cell stacks. Calculation is done for a 100-cell molten carbonate fuel-cell stack with internal manifolds. The results show that the pressure-loss by wall friction is negligible compared with the pressure recovery in inlet manifolds or loss in outlet manifolds due to mass dividing or combining flow at manifold-cell junctions. A more significant effect on manifold pressure possibly arises from the geometrical manifold structure which depends on the manifold size and shape. The geometrical effect is approximated from pressure-loss coefficients of several types of fittings and valves. The overall pressure and flow distribution is significantly affected by the value of the geometrical pressure-loss coefficient. It is also found that the flow in manifolds is mostly turbulent in the 100-cell stack and this way result in an uneven flow distribution when the stack manifold is incorrectly, designed.

Koh, Joon-Ho; Seo, Hai-Kyung; Lee, Choong Gon; Yoo, Young-Sung; Lim, Hee Chun

30

Evaluation of gas cooling for pressurized phosphoric acid fuel cell stacks  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

31

Evaluation of gas cooling for pressurized phosphoric acid fuel cell stacks  

NASA Astrophysics Data System (ADS)

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

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

32

Theoretical analysis of stack gas emission velocity measurement by optical scintillation  

NASA Astrophysics Data System (ADS)

Theoretical analysis for an online measurement of the stack gas flow velocity based on the optical scintillation method with a structure of two parallel optical paths is performed. The causes of optical scintillation in a stack are first introduced. Then, the principle of flow velocity measurement and its mathematical expression based on cross correlation of the optical scintillation are presented. The field test results show that the flow velocity measured by the proposed technique in this article is consistent with the value tested by the Pitot tube. It verifies the effectiveness of this method. Finally, by use of the structure function of logarithmic light intensity fluctuations, the theoretical explanation of optical scintillation spectral characteristic in low frequency is given. The analysis of the optical scintillation spectrum provides the basis for the measurement of the stack gas flow velocity and particle concentration simultaneously.

Yang, Yang; Dong, Feng-Zhong; Ni, Zhi-Bo; Pang, Tao; Zeng, Zong-Yong; Wu, Bian; Zhang, Zhi-Rong

2014-04-01

33

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

34

Independent determination of the accuracy of the OSTR stack gas monitor and its operational application  

Microsoft Academic Search

This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As

B. D. Pickett; A. G. Johnson

1982-01-01

35

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

36

High efficiency particulate air filter lives in hydrogen fluoride gas environments.  

National Technical Information Service (NTIS)

Tests of high-efficiency particulate air filters were requested following catastrophic failure of a filter by hydrogen fluoride gas from improper operation in a production line. Operational lives in hydrogen fluoride environments of high-efficiency partic...

J. A. Compton

1992-01-01

37

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...

38

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

Microsoft Academic Search

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

Dehne

1980-01-01

39

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

40

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...

41

Stack gas emissions of PCDD/Fs from hospital waste incinerators in China.  

PubMed

Stack gas samples from 14 domestic-made hospital waste incinerators (HWIs) in China were collected and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The waste burning capacities of the investigated HWIs ranged from 5 to 25 ton d(-1). The stack gas emissions of PCDD/Fs from HWIs exhibited a large variation (0.08-31.60 ng I-TEQNm(-3)). Nine incinerators had the emission levels below the current emission standard in China (0.5 ng I-TEQN m(-3)), while only two facilities exhibited emission levels below the European Union directive emission limit (0.1 ng I-TEQN m(-3)). For two plants, concentrations of PCDD/Fs in stack gas were above 10.0 ng I-TEQN m(-3). The emission factors of PCDD/Fs from the investigated HWIs were in the range of 0.78-473.97 microg I-TEQ ton(-1) medical wastes. It was estimated that 4.87 g I-TEQ of PCDD/Fs was annually released from HWIs to the atmosphere in China in 2006. Principal component analysis and hierarchical cluster analysis were applied to analyze the congener profiles of PCDD/Fs from HWIs in China. PMID:19740512

Gao, Hongcai; Ni, Yuwen; Zhang, Haijun; Zhao, Liang; Zhang, Ning; Zhang, Xueping; Zhang, Qing; Chen, Jiping

2009-10-01

42

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

43

Thermal Processing of Particulate Solids in a Gas-Fired Pulse Combustion System  

Microsoft Academic Search

An experimental study on thermal processing of particulate solids has been carried out on a valved pulse combustion unit. The test-bench consists of a 60 kW natural gas-fired valved (flappers) pulse combustor having a 4.63 × 10 m combustion chamber, horizontal tailpipe with variable geometry, and a cylindrical drum. The particulate solid used is clean sand (311 µm and 2646 kg\\/m), which flows within the tailpipe

Marzouk Benali; Robert Legros

2004-01-01

44

A bounding assessment method for correlating measured gas leaks to the possible loss of particulate contents from radioactive materials packages  

Microsoft Academic Search

A method is presented for correlating a tracer gas leakage rate to the potential particulate radioactive material (RAM) release from packages for the shipment of RAM, for those cases where a gas leak measurement is used and there is no measurable particulate release. The correlation method involves a calculational technique relating the measured gas leakage to capillary flow, then to

1986-01-01

45

Microcomputer programs for particulate control: section failure; baghouse; plume opacity prediction; and in-stack opacity calculator. Software  

Microsoft Academic Search

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 the IBM-PC versions. The programs are written in FORTRAN and are provided in both source (FORTRAN) and

Sparks

1985-01-01

46

Reactive plume model: Effect of stack exit conditions on gas phase precursors and sulfate formation  

NASA Astrophysics Data System (ADS)

A simple form of a carbon-bond smog mechanism has been introduced into a complete set of plume conservation equations. The conservation expressions for mass, momentum, energy and component species have been solved numerically for typical source and neutral or adiabatic ambient conditions to simulate the homogeneous gas phase chemistry for approximately two hours of travel time downwind from the stack exit. The influence of stack exit conditions including the ratios of momentum-to-buoyancy length lm/ lb, source-to-ambient velocity R and mixing-to-reaction time ? are demonstrated. It was found that homogeneous processes in the plume near-field do not significantly contribute to the overall conversion of SO 2 to SO 2-4. In the far-field maximum sulfate formation rates of 2.3% h -1 were predicted for clear summer noon hours, consistent with plume measurements. Variation of stack exit conditions were found to have little effect on the maximum SO 2 conversion rate or the peak OH radical concentration where local HC/NO x ratios between 16 and 22 were predicted. Parameter changes resulting in greater ambient entrainment rates, however, were found to shift the development of the radical pool closer to the source and to significantly increase the total molar flux of plume sulfate.

Forney, L. J.; Droescher, F. M.

47

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

48

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

49

Sources and atmospheric distribution of particulate and gas-phase boron  

NASA Astrophysics Data System (ADS)

Atmospheric samples were collected during warm and cold weather conditions at continental, coastal and marine sites. Source sampling was performed at a coal-fired power plant and several volcanic sites. Atmospheric gas-phase and particulate boron concentrations were determined by neutron capture prompt-gamma activation analysis and compared to measurements from other studies. Rain and snow samples collected at one continental site were analysed for soluble and insoluble B. Volcanic deposit and ash samples were also analysed for B. The tropospheric burdens for particulate and gas-phase B were estimated to be 0.6 × 10 10 g and (6-11) × 10 10 g, respectively, with the latter about a factor of 3 lower than previous estimates. Global anthropogenic particulate and gas-phase B source estimates were consistent with previous estimates, and natural particulate and gas-phase B source estimates agreed reasonably well with previously reported upper limits. About 65-85 % of total B source strength can be attributed to the oceans, and 8-20% to coal, agricultural, fuelwood and refuse burning. Volcanism may contribute 6-15% of the total, but accurate source estimates are difficult. Total global B removal from the atmosphere by wet and dry deposition was estimated to be (530-700) × 10 10 g yr -1, a factor of 2 lower than previously reported but in fairly good agreement with the global total B source estimate of (200-530) × 10 10 g yr -1.

Anderson, David L.; Kitto, Michael E.; McCarthy, Lauren; Zoller, William H.

50

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

51

Aerodynamic improvement of the assembly through which gas conduits are taken into a smoke stack by simulating gas flow on a computer  

NASA Astrophysics Data System (ADS)

Results from computer simulation of gas flow motion for gas conduits taken on one and two sides into the gas-removal shaft of a smoke stack with a constant cross section carried out using the SolidWorks and FlowVision application software packages are presented.

Prokhorov, V. B.; Fomenko, M. V.; Grigor'ev, I. V.

2012-06-01

52

Gas and Particulate Sampling of Airborne Polycyclic Aromatic Compounds  

SciTech Connect

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

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

1995-10-01

53

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...

54

An Experimental Investigation of an Exhaust-gas-to-air Heat Exchanger for Use on Jet-stack-equipped Engines  

NASA Technical Reports Server (NTRS)

Tests were made to determine the loss in exhaust-jet thrust and engine power resulting from the insertion of an exhaust-gas-to-air heat exchanger in a jet-type exhaust stack of an aircraft engine. The thermal performance of the heat exchanger was also determined.

Stalder, Jackson R; Spies, Ray J , Jr

1948-01-01

55

Calculation of combustion gas flow rate and residence time based on stack gas data  

Microsoft Academic Search

In many situations, it is desired to estimate the combustion chamber gas residence time of operating combustion systems. This is typically accomplished by performing a mass and energy balance around the combustion chamber. Unfortunately, the detailed physical, chemical, and thermodynamic data needed for each of the feed streams, effluents, and combustion gases are often not readily available. Further, a rigorous

Anthony R. Eicher

2000-01-01

56

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

57

The composition of lignin in estuarine suspended particulates and the distribution of particulate lignin in estuaries as determined by capillary gas chromatography of cupric oxide oxidation products  

NASA Astrophysics Data System (ADS)

The contribution of lignin to the estuarine suspended particulate fraction is described in terms of its distribution over a spring tide and a neap tide in the Tamar Estuary, Southwest England and the Mersey Estuary, Northwest England. Suspended particulate samples are treated with CuO?NaOH at 170°C to yield simple, lignin-derived phenolic compounds, which are separated, derived and quantified by capillary gas chromatography with flame ionization detection (GC-FID). Estuarine distributions of particulate lignin are described and the sources and compositional changes of the lignin identified. Comparison of the lignin concentrations in the suspended material with those in the underlying sediment reveals that lignin is preferentially enriched in the suspended material.

Reeves, A. D.; Preston, M. R.

1989-12-01

58

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

59

Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis  

Microsoft Academic Search

Electrolysis of steam and co-electrolysis of steam and carbon dioxide was studied in Solid Oxide Electrolysis Cell (SOEC) stacks composed of Ni\\/YSZ electrode supported SOECs. The results of this study show that long-term electrolysis is feasible without notable degradation in these SOEC stacks. The degradation of the electrolysis cells was found to be influenced by the adsorption of impurities from

Sune Dalgaard Ebbesen; Jens Høgh; Karsten Agersted Nielsen; Jens Ulrik Nielsen; Mogens Mogensen

2011-01-01

60

Mobile Gas and Particulate Emission Studies of the New York City Transit Bus Fleet  

NASA Astrophysics Data System (ADS)

Emissions from both diesel and gasoline powered motor vehicles are a significant source of particulate (PM2.5) and trace gas pollution, especially in urban environments. Emission characterizations of motor vehicles can be performed using a dynamometer but these studies make fleet characterization impractical. Few studies have been performed which characterize emissions from in-use vehicles using a mobile sampling platform. This work describes application of new technology instrumentation for rapid (1-5 second) and real-time characterization of both gas and particulate emissions from in-use vehicles and is part of the PM2.5 Technology Assessment and Characterization Study in New York (PMTACS-NY). An aerosol mass spectrometer (AMS) and a tunable infrared laser differential absorption spectrometer (TILDAS) system were deployed on the Aerodyne Research mobile laboratory designed to "chase" target vehicles in and around the New York City area and measure their emissions under actual driving conditions. The AMS provides particle size and composition information for volatile and semi-volatile matter while the TILDAS system was configured to measure NO, NO2, CO, CH4, SO2 and formaldehyde. In addition to a GPS, an ELPI and a condensation particle counter, the mobile laboratory was also equipped with a CO2 monitor to allow emission ratios to be computed for the targeted vehicles. Emission ratios for both particulate and trace gases are reported for a representative fraction of the NYC Metropolitan Transit Authority (MTA) bus fleet in an effort to characterize new emission control technologies currently implemented by the NYC MTA.

Jayne, J. T.; Canagaratna, M.; Herndon, S.; Shorter, J.; Zahniser, M.; Shi, Q.; Kolb, C.; Worsnop, D.; Jimenez, J.; Drewnick, F.; Demerjian, K.; Lanni, T.

2001-12-01

61

Real-Time Characterization of Particle and Gas Phase Diesel Emissions - Understanding the Influence of a Diesel Particulate Filter  

NASA Astrophysics Data System (ADS)

Diesel engine emissions constitute an important source of particulate black carbon (BC) and gas phase organics in the atmosphere. Particles composed of black carbon absorb incoming solar radiation having a net positive radiative forcing effect on the climate. Black carbon also has major air quality implications as BC particles from combustion sources are often coated with poly-aromatic hydrocarbons (PAHs), and are generally emitted in higher concentrations close to population centers. Regulations of diesel emissions target the mass of particulate matter (PM) and concentration of volatile gas phase organic compounds (VOC) produced. A third, potentially important component of diesel exhaust, is low volatility organic compounds (LVOC). Both the VOCs and LVOCs can lead to the formation of ultrafine particles (via homogeneous nucleation) and secondary organic aerosols (via oxidation). Recent development of mass spectrometric techniques to measure particulate black carbon and gas phase organics provide the opportunity to quantify and chemically characterize diesel emissions in real-time. Measurements of both the particulate and gas phase emissions from a medium-duty diesel engine will be presented. The experimental apparatus includes a diesel particulate filter (DPF) integrated in the exhaust line, which is a requirement for all 2007 and newer on-road diesel engines in the U.S. Measurements taken over the regeneration cycle of the DPF provide insight into how this after-treatment technology influences the gas phase and particle phase composition of the emissions. Gas phase measurements were made with a newly developed Total Gas-Phase Organic (TGO) instrument. Particulate species were characterized with a Soot Particle Aerosol Mass Spectrometer (SP-AMS). The combined utility of the TGO and SP-AMS instruments for emissions characterization studies will be demonstrated.

Cross, E. S.; Sappok, A.; Carrasquillo, A. J.; Onasch, T. B.; Fortner, E.; Jayne, J.; Wong, V.; Worsnop, D. R.; Kroll, J. H.

2010-12-01

62

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

DOEpatents

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

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

1997-01-01

63

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

DOEpatents

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

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

1997-08-05

64

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

65

Gas- and particulate-phase specific tracer and toxic organic compounds in environmental tobacco smoke.  

PubMed

Cigarette smoke constituents are worthy of concern and characterized as carcinogens. Different experiment conditions may affect the environmental tobacco smoke (ETS) constituents. A study was undertaken in a 75.5-m3 spare office to evaluate ETS constituents in a real environment. Thirty-four volatile organic compounds (VOCs) including three ETS tracers: nicotine, 2,5-dimethylfuran and 3-ethenylpyridine (3-EP), 19 carbonyl compounds, 54 semi-volatile compounds (24 polycyclic aromatic hydrocarbons (PAHs) and 30 alkanes) as well as CO and total particulate matter (TPM) from 15 leading commercial brands were determined. ETS constituents did not increase with increasing cigarette tar. ETS tracers nicotine and 3-EP were affected greatly due to more sorption and surface reactions in real world compared to other studies conducted in chamber, which resulted in 2-5 times lower. Benzene, toluene, ethylbenzene, xylenes, acrolein, 2-butanone and the high molecular weight compounds exhibited little affect. Pearson correlation analyses show that gas-phase and particulate-phase ETS tracers did not show significant correlation, but within each homologue many of compounds correlated significantly. Indole and cholesta-3,5-diene were also detected in ETS. These results may be useful in efforts to better understand the health effect of ETS exposure and source apportionment. PMID:15975627

Bi, Xinhui; Sheng, Guoying; Feng, Yanli; Fu, Jiamo; Xie, Juexin

2005-12-01

66

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

67

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

68

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

Microsoft Academic Search

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

Sue Anne N. Sheya

2002-01-01

69

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...

70

Comparison of different gas-phase mechanisms and aerosol modules for simulating particulate matter formation.  

PubMed

The effects of two gas-phase chemical kinetic mechanisms, Regional Atmospheric Chemistry Mechanism version 2 (RACM2) and Carbon-Bond 05 (CB05), and two secondary organic aerosol (SOA) modules, the Secondary Organic Aerosoi Model (SORGAM) and AER/EPRI/Caltech model (AEC), on fine (aerodynamic diameter < or =2.5 microm) particulate matter (PM2.5) formation is studied. The major sources of uncertainty in the chemistry of SOA formation are investigated. The use of all major SOA precursors and the treatment of SOA oligomerization are found to be the most important factors for SOA formation, leading to 66% and 60% more SOA, respectively. The explicit representation of high-NO, and low-NOx gas-phase chemical regimes is also important with increases in SOA of 30-120% depending on the approach used to implement the distinct SOA yields within the gas-phase chemical kinetic mechanism; further work is needed to develop gas-phase mechanisms that are fully compatible with SOA formation algorithms. The treatment of isoprene SOA as hydrophobic or hydrophilic leads to a significant difference, with more SOA being formed in the latter case. The activity coefficients may also be a major source of uncertainty, as they may differ significantly between atmospheric particles, which contain a myriad of SOA, primary organic aerosol (POA), and inorganic aerosol species, and particles formed in a smog chamber from a single precursor under dry conditions. Significant interactions exist between the uncertainties of the gas-phase chemistry and those of the SOA module. PMID:22168105

Kim, Youngseob; Couvidat, Florian; Sartelet, Karine; Seigneur, Christian

2011-11-01

71

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

72

Modular fuel-cell stack assembly  

DOEpatents

A modular multi-stack fuel-cell assembly in which the fuel-cell stacks are situated within a containment structure and in which a gas distributor is provided in the structure and distributes received fuel and oxidant gases to the stacks and receives exhausted fuel and oxidant gas from the stacks so as to realize a desired gas flow distribution and gas pressure differential through the stacks. The gas distributor is centrally and symmetrically arranged relative to the stacks so that it itself promotes realization of the desired gas flow distribution and pressure differential.

Patel, Pinakin (Danbury, CT) [Danbury, CT; Urko, Willam (West Granby, CT) [West Granby, CT

2008-01-29

73

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

Code of Federal Regulations, 2010 CFR

...instrumentation calibration; particulate, methanol, and formaldehyde measurement...instrumentation calibration; particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions...

2009-07-01

74

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

Code of Federal Regulations, 2010 CFR

...instrumentation calibration; particulate, methanol and formaldehyde measurement. 86...instrumentation calibration; particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions...

2010-07-01

75

Gas/solid particulate phthalic esters (PAEs) in Masson pine (Pinus massoniana L.) needles and rhizosphere surface soils.  

PubMed

Phthalic acid esters (PAEs) are used in many branches of industry and are produced in huge amounts throughout the world. An investigation on particulate- and gas-phase distribution of PAEs has been conducted between January 2011 and December 2012 in Nanjing (China). Masson pine (Pinus massoniana L.) needles and rhizosphere surface soils were sampled from urban to suburban/remote sites, to investigate the pine needle/soil distribution of PAEs. The results showed that the average total PAE concentration (gas+particle) was 97.0ngm(-3). The six PAE congeners considered predominantly existed in the gas phase and the average contribution of gas phase to total PAEs ranged from 75.0% to 89.1%. The PAE concentrations in rhizosphere soils and pine needles were positively correlated with their particulate- and gas-phase concentrations, respectively, which suggested that surface soils accumulated PAEs mainly through gravity deposition of particles and pine needle stomata absorbed PAEs mainly from the gas phase. The gas/particle partitioning (KP) and soil-pine needle ratio (Rs/n) were determined. Experimentally determined KP values correlated well with the subcooled liquid vapor pressures (PL). A set of interesting relationships of logRs/n-logKP-logPL was employed to explain the experimental findings of PAEs deposition to surface soils and to needles. This data set offered a unique perspective into the influence that Rs/n played in KP and correlated with PL. PMID:24887117

Wang, Wen-Xin; Fan, Chinbay Q

2014-07-15

76

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

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Particulate tests; canisters containing particulate filters... Gas Masks § 84.125 Particulate tests; canisters containing particulate filters...183, except for the airflow resistance test of §...

2012-10-01

77

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...

78

Gas phase nitric acid, ammonia and related particulate matter at a Mediterranean coastal site, Patras, Greece  

Microsoft Academic Search

Measurements of nitric acid, ammonia and related particulate matter were made at a coastal site in Greece to elucidate the local factors that affect the concentrations of each of these species, as well as the atmospheric transport of particulate sulfate. Seasonal variation with higher concentrations in the summer was observed for all measured species. This variation was more pronounced for

Demetrios Danalatos; Sotirios Glavas

1999-01-01

79

Simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters by gas chromatography-mass spectrometry  

NASA Astrophysics Data System (ADS)

A gas chromatography-mass spectrometry (GC-MS) method has been proposed for the simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters (PMs). The method includes collection of the particulate matters (PM2.5 and PM10) using dichotomous Partisol 2025 sampler followed by extraction of the compounds into acidic solution, and pre-concentration of the compounds by percolating the air samples through the acidic solution, then ion-pair extraction of amines with bis-2-ethylhexylphosphate and derivatisation with isobutyl chloroformate prior to their GC-MS analysis in both electron impact and positive and negative ion chemical ionisation mode as their isobutyloxycarbonyl (isoBOC) derivatives. In the present study, ambient air and airborne particulate samples collected in Zonguldak province during summer and winter times of 2006-2007 were analysed for aliphatic and aromatic amines by the proposed method and the method was shown to be suitable for the simultaneous determination of these compounds at the levels of pg m-3 in air and airborne particulate samples. The seasonal distributions of bioactive amines in concentrations in ambient air and airborne PMs were evaluated as they are significant for the estimation of their effects on the environment and human health. The concentration levels of water soluble amines fluctuate significantly within a year with higher means and peak concentrations, probably due to the increased emissions from coal-fired domestic and central heating, in the winter times compared to the summer times. The results indicated that the relative amine content in particulates modulates with molecular mass and time of the year and the relative amine content especially in fine fractions of inhalable airborne particulates increases with the molecular mass of species but decreases with temperature.

Akyüz, Mehmet

2008-05-01

80

Casting particulate and fibrous metal-matrix composites by vacuum infiltration of a liquid metal under an inert gas pressure  

Microsoft Academic Search

A new method of making metal-matrix composites is reported. This method combines the essentials of three liquid-phase fabrication\\u000a methods: (i) vacuum infiltration, (ii) infiltration under an inert gas pressure, and (iii) squeeze casting. In this method,\\u000a the particulate or fibrous preform is placed in a mould and the matrix alloy is placed above the preform. The matrix alloy\\u000a is heated

Jingyu Yang; D. D. L. Chung

1989-01-01

81

Principal characteristics of turbulent gas-particulate flow in the vicinity of single tube and tube bundle structure  

Microsoft Academic Search

In this paper the particle rebounding characteristics of a gas–particle flow over a cylindrical body and an in-line tube bundle arrangement is investigated. With the aid of both experimental and numerical approaches, the mean particulate flow patterns, comprising both incident and rebound particles resulting from the impact of particles on solid walls, are examined. In the experimental investigation, a two-dimensional

Y. S. Morsi; J. Y. Tu; G. H. Yeoh; W. Yang

2004-01-01

82

Continuous multicomponent stack gas analyzer using ultraviolet-photodiode-array spectroscopy  

NASA Astrophysics Data System (ADS)

Ammonia injection is frequently used to reduce emissions of nitrogen oxides from modern combustion plant. Accurate measurements of ammonia and nitric oxide are therefore required to ensure optimum operation of the NOx control system. Measurements of sulphur dioxide are also required to ensure compliance with legislation in most countries. An extractive analytical system has been developed for continuous measurements of ammonia, nitric oxide and sulphur dioxide concentrations in stack gases based on an ultraviolet spectrometer using a photodiode array detector operating in the 200nm region. The use of the photodiode array spectrometer enables the system to have a fast response time while maintaining excellent wavelength stability and reliability, since there are no moving parts in the main optical system. A high temperature sampling system is coupled to a hot sample cell to ensure that there is no degradation of the sample prior to measurement. Tests in the laboratory and at a combustion plant in Europe have shown practical detection limits of 1ppm for all of the target gases.

Stuart, Derek D.

1997-05-01

83

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

84

Fractionator for size classification of aerosolized solid particulate matter  

Microsoft Academic Search

A system is developed for collecting kilogram quantities of size-fractionated particulate matter which can be subsequently used for biologic testing purposes. The apparatus consists of a series of two cyclones and a centripeter and yields four size fractions. When used over a 12-day period to classify fly ash from stack gas passed through the electrostatic precipitator of a coal-fired power

Andrew R. McFarland; Russell W. Bertch; Gerald L. Fisher; Bruce A. Prentice

1977-01-01

85

Real-time measurements of particulate matter and polycyclic aromatic hydrocarbon emissions from stationary combustion sources used in oil and gas production  

SciTech Connect

Particulate matter emissions and some components of the particles were measured in the exhaust from combustion equipment used in oil and gas production operations near Bakersfield, California. The combustion sources included a 22.5 MW (electric) turbine generator, a 342-Bhp rich-burn spark ignition engine, and a 50 million Btu/h steam generator, all fired using natural gas. The particle components and measurement techniques were as follows: (1) Calcium, magnesium, sodium, silicon, and iron were measured using laser-induced breakdown spectroscopy (LIBS), (2) particle-bound polycyclic aromatic hydrocarbons (PAH) were detected using the charge produced by photoionization, (3) particles having sizes between 0.1 and 7.5 {micro}m were counted using an instrument based on light scattering, and (4) total particulate matter was measured according to US EPA Method 5. Not all of the methods were applied to all of the sources. Measurements were also made in the ambient air near the combustion air inlets to the units, for comparison with the concentrations in the exhaust, but the inlet and outlet measurements were not done simultaneously. Calcium, sodium, and silicon were found in the exhaust from the steam generator at concentrations similar to those in the ambient air near the inlet to the burner. Sodium and silicon were observed in the engine exhaust at levels a factor of four higher than their concentrations in the air. The principal metal observed in the engine exhaust was calcium, a component of the lubricating oil, at a concentration of 11.6 {micro}g/m{sup 3}. The air entering the gas turbine is filtered, so the average concentrations of metals in the turbine exhaust under steady operating conditions were even lower than in the air. During start-up following a shut-down to wash the turbine, silicon and iron were the major species in the stack, at concentrations of 6.4 and 16.2 {micro}g/m{sup 3}, respectively. A possible source of silicon is the water injected into the turbine for NO{sub x} control. Iron-containing particles are expected to be scale from ferrous metals. A commercial photoelectric aerosol sensor was used to measure PAH adsorbed on particles in the exhaust from the steam generator and the rich-burn engine. The conversion of the instrument readings to PAH concentrations is dependent upon the specific distribution of PAH species present. Using the typical calibration factor recommended by the instrument manufacturer, the estimated average concentration of particle-bound PAH was below the instrument detection limit (3--10 ng/m{sup 3}) in the stack gas from the steam generator, and was estimated to be 0.045--0.15 {micro}g/m{sup 3} in the exhaust from the rich-burn engine. Particle mass concentrations estimated from number concentrations determined using the particle counting and sizing instrument were only small fractions of the concentrations measured using Method 5. This is thought to be due primarily to the limited range over which size was quantified (0.1 to 7.5 {micro}m) and the poor efficiency with which the sampling system transferred large particles.

D. w. Hahn; K. r. Hencken; H. A. Johnsen; J. R. Ross; P. M. Walsh

1998-12-10

86

Gas phase nitric acid, ammonia and related particulate matter at a Mediterranean coastal site, Patras, Greece  

NASA Astrophysics Data System (ADS)

Measurements of nitric acid, ammonia and related particulate matter were made at a coastal site in Greece to elucidate the local factors that affect the concentrations of each of these species, as well as the atmospheric transport of particulate sulfate. Seasonal variation with higher concentrations in the summer was observed for all measured species. This variation was more pronounced for nitric acid, ammonia and particulate ammonium, in agreement with greater nitric acid production in the summer because of larger hydroxyl radical concentrations and larger ammonia emissions at higher temperatures. The high summer temperatures and low relative humidity of our region favor gaseous nitric acid and ammonia over particulate ammonium nitrate. In fact our data indicate that ammonium nitrate was not predicted to be formed in the summer, whereas it was predicted to be formed in the spring. Mean nitric acid/particulate nitrate ratios ranged from 1.3 to 4.0. Air mass back trajectories showed that the higher concentrations of the long-lived particulate sulfate were long-range transported from northern directions. High sulfate concentrations 7-11 ?g m -3 were observed in the summer. On an equivalent basis particulate sulfate were 5-15 times larger than particulate nitrate reflecting higher sulfur over nitrogen emissions, as is observed in most studies. Nitric acid exhibited the more pronounced diurnal variation from all measured species; this was more apparent in the summer in agreement with a short lifetime, estimated here at about half a day. Peak nitric acid concentrations of 4-6 ?g m -3 were measured in the afternoon hours in the summer. Local meteorology and photochemistry appear to control the variation of nitric acid and ammonia concentrations.

Danalatos, Demetrios; Glavas, Sotirios

87

Sulfate Aerosol Particulates  

NASA Astrophysics Data System (ADS)

The condensation of SO3 vapor to detrimental acid-mist occurs only after substantial flue gas cooling, usually downstream from electrostatic precipitators. This condensation is an equilibrium process depending on gas temperature and water vapor pressure. Smelter plume opacity is related to acidmist and other sulfate aerosol particulate concentration through Mie particulate scattering theory. It is possible to estimate the amounts of sulfate particulate emissions and plume opacity, particularly those resulting from anticipated changes in smelter operations and flue gas treatment. These estimates can be used to determine compliance with current or anticipated regulations on smelter particulate emissions or plume opacity.

Bartlett, Robert W.

1987-09-01

88

Particulate technology issues  

Microsoft Academic Search

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

D. H. Pontius; P. Vann Bush

1992-01-01

89

Slip stacking  

SciTech Connect

We have started beam studies for ''slip stacking''[1] in the Main Injector in order to increase proton intensity on a target for anti-proton production. It has been verified that the system for slip stacking is working with low intensity beam. For a high intensity operation, we are developing a feedback[2][3] and feedforward system.

Kiyomi Koba and James Steimel

2002-09-19

90

Stacked generalization  

Microsoft Academic Search

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

David H. Wolpert

1992-01-01

91

Compound Specific Concentration and Stable Isotope Ratio Measurements of Atmospheric Particulate Organic Matter and Gas Phase Nitrophenols  

NASA Astrophysics Data System (ADS)

Atmospheric particulate organic matter (POM) adversely affects health and climate. One of the still poorly understood sources of secondary organic matter (SOM) is the formation of secondary POM from the photo- oxidation of atmospheric volatile organic compounds (VOC). Nitrophenols, which are toxic semi-volatile compounds, are formed in the atmosphere by OH-radical initiated photo-oxidation of aromatic hydrocarbons, such as toluene. A method was developed to determine concentrations and stable carbon isotope ratios of particulate methyl nitrophenols in the atmosphere. This method has been used to quantify methyl nitrophenols, specifically 2-methyl-4-nitrophenol and 4-methyl-2-nitrophenol, found in atmospheric PM samples in trace quantities. Using this method, we conducted measurements of methyl nitrophenols in atmospheric PM in rural and suburban areas in Southern Ontario. The results of these measurements showed that the concentration of methyl nitrophenols in atmospheric PM is much lower than expected from the extrapolation of laboratory experiments and measured atmospheric toluene concentrations. In order to better understand the reasons for these findings, an analytical method for the analysis of nitrophenols in the gas phase is currently being developed. Similarly, the measurement technique is modified to allow analysis of other phenolic products of the oxidation of aromatic hydrocarbons in PM as well as in the gas phase. In this poster, sampling techniques for collection and GC-MS analysis of nitrophenols in gas phase and PM will be presented along with preliminary results from summer 2008 and spring 2009 studies.

Busca, R.; Saccon, M.; Moukhtar, S.; Rudolph, J.

2009-05-01

92

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

93

Application of micro-scale sealed vessel thermal desorption–gas chromatography–mass spectrometry for the organic analysis of airborne particulate matter: linearity, reproducibility and quantification  

Microsoft Academic Search

Micro-scale sealed vessel thermal desorption–gas chromatography–mass spectrometry (MSSV-TD–GC–MS) has been applied to the analysis of airborne particulate matter using the US NIST Standard Reference Material (SRM1649a) urban dust. We make qualitative comparisons with open system desorption and illustrate that caution should be used when using the technique without an open system comparison. We report linear responses over the same particulate

Daniel Waterman; Brian Horsfield; Keith Hall; Steve Smith

2001-01-01

94

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

Microsoft Academic Search

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

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

2007-01-01

95

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

96

40 CFR 60.672 - Standard for particulate matter (PM).  

Code of Federal Regulations, 2013 CFR

...false Standard for particulate matter (PM). 60.672 Section 60.672 Protection...672 Standard for particulate matter (PM). (a) Affected facilities must...bin is exempt from the applicable stack PM concentration limit (and associated...

2013-07-01

97

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

98

Identification of oxygenated polycyclic aromatic hydrocarbons in diesel particulate matter by capillary gas chromatography and capillary gas chromatography\\/mass spectrometry  

Microsoft Academic Search

Summary  Using a two-step liquid chromatographic separation on normalphase cartridges, crude extracts of diesel particulate matter\\u000a can be separated without time-consuming sample handling into special fractions which mainly contain slightly-polar oxygenated\\u000a polycyclic aromatic hydrocarbons (oxy-PAH) and nitrated polycyclic aromatic hydrocarbons (nitro-PAH). Subsequent analysis\\u000a was by fused-silica capillary gas chromatography on a SE54 column along with flame-ionisation (GC\\/FID) and positive-ion electron-impact\\u000a mass

J. Schulze; A. Hartung; H. Kieß; J. Kraft; K.-H. Lies

1984-01-01

99

Modeling of Particulate Emissions.  

National Technical Information Service (NTIS)

Atmospheric levels of PM2.5 particulate matter near airports are increased by solid carbonaceous soot and condensable gaseous species emitted by military and commercial gas turbine aircraft engines. Carbonaceous materials are formed in the main combustor ...

M. Colket

2011-01-01

100

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

101

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...

102

Isolation of mononitrated polycyclic aromatic hydrocarbons in particulate matter by liquid chromatography and determination by gas chromatography with the thermal energy analyzer  

Microsoft Academic Search

Nitrated polycyclic aromatic hydrocarbons (NPAH), which are extracted ultrasonically from particulate matter, are fractionated conveniently with a semipreparative scale high-pressure liquid chromatographic system. The NPAH present in the enriched isolate are determined by use of a gas chromatograph equipped with a thermal energy analyzer (TEA). Turnaround time is 8 h per sample. The HPLC separation permits selectivity for NPAH by

Bruce A. Tomkins; Roswitha S. Brazell; Mary E. Roth; Vanessa H. Ostrum

1984-01-01

103

Control of combustibility of volatile hydrocarbons and particulate matter in an exhaust gas stream by use of a high velocity burner in a carbon bake ring furnace  

Microsoft Academic Search

The present invention relates to a method of and an apparatus for controlling the combustibility of volatile hydrocarbons and particulate matter in an exhaust gas stream driven off from a carbon product being baked in a furnace. In a prebaking stage, the carbon product is heat treated in a temperature range of 300 to 600° C. In order to drive

F. D. Arnold; C. M. Benton; G. D. Evrad; H. O. Forberg; R. L. Tuscher

1981-01-01

104

Real-time measurements of particulate matter and polycyclic aromatic hydrocarbon emissions from stationary combustion sources used in oil and gas production  

Microsoft Academic Search

Particulate matter emissions and some components of the particles were measured in the exhaust from combustion equipment used in oil and gas production operations near Bakersfield, California. The combustion sources included a 22.5 MW (electric) turbine generator, a 342-Bhp rich-burn spark ignition engine, and a 50 million Btu\\/h steam generator, all fired using natural gas. The particle components and measurement

D. w. Hahn; K. r. Hencken; H. A. Johnsen; J. R. Ross; P. M. Walsh

1998-01-01

105

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

NASA Astrophysics Data System (ADS)

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

Kumar, Sumit; Das, Aloke

2013-06-01

106

WOOD SMOKE: MEASUREMENT OF THE MUTAGENIC ACTIVITIES OF ITS GAS- AND PARTICULATE-PHASE PHOTOOXIDATION PRODUCTS  

EPA Science Inventory

Dilute mixtures of wood combustion emissions (with and without additional NOx) were irradiated in a 22.7-m3 Teflon smog chamber. The effluent was tested for mutagenic activity by exposing Salmonella typhimurium, strains TA100 and TA98, to the filtered gas-phase components. The pa...

107

Trace gas and particulate emissions from the 2003 southern California wildfires  

Microsoft Academic Search

In October 2003, thirteen major wildfires in southern California burned more than 300,000 hectares of mainly chaparral biome. High-precision in situ trace gas and particle measurements of the wildfire plumes in La Jolla, California, showed a high degree of correlation among carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons, and methyl halide mixing ratios, as well as with particle number concentrations

J. Mühle; T. J. Lueker; Y. Su; B. R. Miller; K. A. Prather; R. F. Weiss

2007-01-01

108

Application of multicriteria decision making methods to compression ignition engine efficiency and gaseous, particulate, and greenhouse gas emissions.  

PubMed

Compression ignition (CI) engine design is subject to many constraints, which present a multicriteria optimization problem that the engine researcher must solve. In particular, the modern CI engine must not only be efficient but must also deliver low gaseous, particulate, and life cycle greenhouse gas emissions so that its impact on urban air quality, human health, and global warming is minimized. Consequently, this study undertakes a multicriteria analysis, which seeks to identify alternative fuels, injection technologies, and combustion strategies that could potentially satisfy these CI engine design constraints. Three data sets are analyzed with the Preference Ranking Organization Method for Enrichment Evaluations and Geometrical Analysis for Interactive Aid (PROMETHEE-GAIA) algorithm to explore the impact of (1) an ethanol fumigation system, (2) alternative fuels (20% biodiesel and synthetic diesel) and alternative injection technologies (mechanical direct injection and common rail injection), and (3) various biodiesel fuels made from 3 feedstocks (i.e., soy, tallow, and canola) tested at several blend percentages (20-100%) on the resulting emissions and efficiency profile of the various test engines. The results show that moderate ethanol substitutions (~20% by energy) at moderate load, high percentage soy blends (60-100%), and alternative fuels (biodiesel and synthetic diesel) provide an efficiency and emissions profile that yields the most "preferred" solutions to this multicriteria engine design problem. Further research is, however, required to reduce reactive oxygen species (ROS) emissions with alternative fuels and to deliver technologies that do not significantly reduce the median diameter of particle emissions. PMID:23343018

Surawski, Nicholas C; Miljevic, Branka; Bodisco, Timothy A; Brown, Richard J; Ristovski, Zoran D; Ayoko, Godwin A

2013-02-19

109

The stepwise gray P-1 approximation for multi-dimensional radiative transfer in molecular-gas-particulate mixtures  

NASA Astrophysics Data System (ADS)

The stepwise gray method is the simplest method for incorporating the effects of absorption-emission bands in radiative heat transfer calculations. The non-gray character of the mixture is replaced by an 'equivalent' stepwise gray character. A method to obtain this equivalent gray character by utilizing the mean beam length is outlined. This method is coupled with the P-1 approximation, resulting in a simple model to deal with radiation from gas-particulate media in multi-dimensional geometries. To validate the accuracy of the method, it is applied to a few simple 1D problems, i.e., to isothermal plane-parallel and spherical media as well as to plane-parallel media at radiative equilibrium. Absorption and scattering behavior are studied for both black and gray walls. Results are compared with those obtained from Monte Carlo calculations incorporating the exponential-wide-band model, indicating good accuracy for all conditions studied, within the limitations of the P-1 approximation.

Modest, Michael F.; Sikka, Kamal K.

1992-08-01

110

Comparative study for hardwood and softwood forest biomass: Chemical characterization, combustion phases and gas and particulate matter emissions.  

PubMed

Two different types of typical Brazilian forest biomass were burned in the laboratory in order to compare their combustion characteristics and pollutant emissions. Approximately 2kg of Amazon biomass (hardwood) and 2kg of Araucaria biomass (softwood) were burned. Gaseous emissions of CO2, CO, and NOx and particulate matter smaller than 2.5?m (PM2.5) were evaluated in the flaming and smoldering combustion phases. Temperature, burn rate, modified combustion efficiency, emissions factor, and particle diameter and concentration were studied. A continuous analyzer was used to quantify gas concentrations. A DataRam4 and a Cascade Impactor were used to sample PM2.5. Araucaria biomass (softwood) had a lignin content of 34.9%, higher than the 23.3% of the Amazon biomass (hardwood). CO2 and CO emissions factors seem to be influenced by lignin content. Maximum concentrations of CO2, NOx and PM2.5 were observed in the flaming phase. PMID:24836706

Amaral, Simone Simões; de Carvalho Junior, João Andrade; Costa, Maria Angélica Martins; Neto, Turíbio Gomes Soares; Dellani, Rafael; Leite, Luiz Henrique Scavacini

2014-07-01

111

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

112

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

SciTech Connect

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

NONE

1996-05-21

113

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 ...

114

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

115

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.

116

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 are described 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 mixture.

Cohen, M.R.; Gal, E.

1993-04-13

117

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) [Troy, NY; Gal, Eli (Lititz, PA) [Lititz, PA

1993-01-01

118

Fuel cell stack arrangements  

DOEpatents

Arrangements of stacks of fuel cells and ducts, for fuel cells operating with separate fuel, oxidant and coolant streams. An even number of stacks are arranged generally end-to-end in a loop. Ducts located at the juncture of consecutive stacks of the loop feed oxidant or fuel to or from the two consecutive stacks, each individual duct communicating with two stacks. A coolant fluid flows from outside the loop, into and through cooling channels of the stack, and is discharged into an enclosure duct formed within the loop by the stacks and seals at the junctures at the stacks.

Kothmann, Richard E. (Churchill Boro, PA); Somers, Edward V. (Murrysville, PA)

1982-01-01

119

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...

120

Ozone, trace gas, and particulate matter measurements at a rural site in southwestern New York state: 1995-2005.  

PubMed

A research site for atmospheric chemistry and air pollution measurements was established at Pinnacle State Park in Addison, NY, in 1995. This paper presents an overview of the site characteristics and measurement program, as well as monthly average concentrations for many of the trace gas and aerosol pollutants over the full measurement period. Monthly averaged ozone concentrations range from values as low as 15 parts per billion (ppb) during cold-season months, to values approaching 50 ppb during some spring and summer months. Sulfur dioxide (SO2), oxides of nitrogen (NOx), and reactive odd nitrogen (NOy) all show distinct seasonal variation, with summertime monthly averages as low as 1-3 ppb, and wintertime monthly averages from 6-12 ppb. The variation in carbon monoxide (CO) is much smaller, with minimums of approximately 150 ppb and maximums only rarely exceeding 250 ppb. Data for three hydrocarbon species--propane, benzene, and isoprene--are presented. Propane and benzene show higher monthly averaged concentrations in the winter and lower values in the summer, with values ranging over a factor of 4-5. Isoprene, on the other hand has much higher values during the summer season, sometimes a factor of 10 or more greater than concentrations measured in the winter. Monthly averaged plots for fine particulate matter (PM2.5) beginning in 1999 show a robust summer maximum and winter minimum, and roughly a factor of two difference between the two. An empirical measure of ozone production using the correlation of hour-averaged ozone and NOy data illustrates relatively robust ozone production during some, but not all, summertime months over the time period. Also, an analysis of the frequency distribution of the hours of maximum ozone concentration shows a strong mid-afternoon peak, as expected, but also a prominent secondary maximum centered around midnight. The secondary peak is interpreted as ozone transported from ozone-producing areas to the west, including Buffalo, Cleveland, Pittsburgh, and the Ohio Valley. Finally, SO2 concentrations as a function of wind direction clearly indicate maximum impacts when the winds are out of the south (Pittsburgh and Philadelphia), with a secondary peak when the winds are from the north-northeast, consistent with the locations of major SO2 emission sources in the region. PMID:19320268

Schwab, James J; Spicer, John B; Demerjian, Kenneth L

2009-03-01

121

Effects of particulates, heavy metals and acid gas on the removals of NO and PAHs by V2O5-WO3 catalysts in waste incineration system.  

PubMed

This study investigated the activities of prepared and commercial V(2)O(5)-WO(3) catalysts for simultaneous removals of NO and polycyclic aromatic hydrocarbons (PAHs) and the influences of particulates, heavy metals, SO(2), and HCl on the performances of catalysts. The experiments were carried out in a laboratory-scale waste incineration system equipped with a catalyst reactor. The DREs of PAHs by prepared and commercial V(2)O(5)-WO(3) catalysts were 64% and 72%, respectively. Increasing the particulate concentrations in flue gas suppressed the DRE of PAHs, but increasing the carbon content on surface of catalysts promotes the NO conversions. The DRE of PAHs by the catalysts was significantly decreased by the increased concentrations of heavy metal Cd, but was promoted by high concentration of Pb. The influence level of SO(2) was higher than HCl on the performances of V(2)O(5)-WO(3) catalysts for PAHs removal, but was lower than HCl for NO removal. Prepared and commercial V(2)O(5)-WO(3) catalysts have similar trends on the effects of particulates, heavy metals, SO(2), and HCl. The results of ESCA analysis reveal that the presence of these pollutants on the surface of catalysts did not change the chemical state of V and W. PMID:19500905

Chang, Feng-Yim; Chen, Jyh-Cherng; Wey, Ming-Yen; Tsai, Shih-An

2009-10-15

122

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...

123

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

124

Stack Monitor Operating Experience Review  

SciTech Connect

Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative “all modes” failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

L. C. Cadwallader; S. A. Bruyere

2009-05-01

125

Compound Specific Concentration and Stable Isotope Ratio Measurements of Atmospheric Particulate Organic Matter and Gas Phase Nitrophenols  

Microsoft Academic Search

Atmospheric particulate organic matter (POM) adversely affects health and climate. One of the still poorly understood sources of secondary organic matter (SOM) is the formation of secondary POM from the photo- oxidation of atmospheric volatile organic compounds (VOC). Nitrophenols, which are toxic semi-volatile compounds, are formed in the atmosphere by OH-radical initiated photo-oxidation of aromatic hydrocarbons, such as toluene. A

R. Busca; M. Saccon; S. Moukhtar; J. Rudolph

2009-01-01

126

Analysis of semi-volatile organic compounds in indoor suspended particulate matter by thermal desorption coupled with gas chromatography/mass spectrometry.  

PubMed

People are exposed to multiple pollutants, especially indoors. In the perspective of a cumulative risk assessment, a multi-residue analytical method was developed to assess the contamination of indoor suspended particulate matter by 55 semi-volatile organic compounds (SVOCs) including musk fragrances, organochlorines (OCs), organophosphates (OPs), polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), phthalates and pyrethroids. It is based on thermal desorption (TD) coupled with gas chromatography/mass spectrometry (GC/MS). Once the thermal desorption conditions were optimized, the method was validated in terms of quantification limits and accuracy using a standard reference material (SRM 2585). Instrumental quantification limits were 10 pg (some OCs, some pyrethroids, musk fragrances, OPs, PAHs, PBDEs and PCBs), 100 pg (phthalates and other OCs) and 1000 pg (other pyrethroids) corresponding respectively to method quantification limits of 1, 10, and 100 pg/m³ for a sampled air volume of 20 m³. Calibration quadratic curves for ranges of 10-1000, 100-10,000, and 1000-100,000 pg, depending on the substance, exhibit determination coefficients above 0.999. Recoveries were between 61 and 96% for chlorinated pesticides, PAHs, PBDEs and PCBs present in the SRM 2585. A test of the method on indoor particulate matter samples (PM??) collected on quartz fiber filters in French dwellings demonstrated its ability to quantify SVOCs from a small amount of PM. PMID:22840824

Mercier, Fabien; Glorennec, Philippe; Blanchard, Olivier; Le Bot, Barbara

2012-09-01

127

Seasonal variation and spatial distribution of atmospheric mercury and its gas-particulate partition in the vicinity of a semiconductor manufacturing complex.  

PubMed

This study investigated the tempospatial variation of atmospheric mercury and its gas-particulate partition in the vicinity of a semiconductor manufacturing complex, where a plenty of flat-monitor manufacturing plants using elemental mercury as a light-initiating medium to produce backlight fluorescence tubes and may fugitively emit mercury-containing air pollutants to the atmosphere. Atmospheric mercury speciation, concentration, and the partition of total gaseous mercury (TGM) and particulate mercury (Hgp) were measured at four sites surrounding the semiconductor manufacturing intensive district/complex. One-year field measurement showed that the seasonal averaged concentrations of TGM and Hgp were in the range of 3.30-6.89 and 0.06-0.14 ng/m(3), respectively, whereas the highest 24-h TGM and Hgp concentrations were 10.33 and 0.26 ng/m(3), respectively. Atmospheric mercury apportioned as 92.59-99.01 % TGM and 0.99-7.41 % Hgp. As a whole, the highest and lowest concentrations of TGM were observed in the winter and summer sampling periods, respectively, whereas the concentration of Hgp did not vary much seasonally. The highest TGM concentrations were always observed at the downwind sites, indicating that the semiconductor manufacturing complex was a hot spot of mercury emission source, which caused severe atmospheric mercury contamination over the investigation region. PMID:24407780

Jen, Yi-Hsiu; Chen, Wei-Hsiang; Yuan, Chung-Shin; Ie, Iau-Ren; Hung, Chung-Hsuang

2014-04-01

128

Fifty years of stacking  

NASA Astrophysics Data System (ADS)

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

Rashed, Mohamed

2014-06-01

129

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

130

Size mass distribution of water-soluble ionic species and gas conversion to sulfate and nitrate in particulate matter in southern Taiwan.  

PubMed

A Micro-Orifice Uniform Deposition Impactor (MOUDI) and a Nano-MOUDI were employed to determine the size-segregated mass distributions of ambient particulate matter (PM) and water-soluble ionic species for particulate constituents. In addition, gas precursors, including HCl, HONO, HNO3, SO2, and NH3 gases, were analyzed by an annular denuder system. PM size mass distribution, mass concentration, and ionic species concentration were measured during the day and at night during episode and non-episode periods in winter and summer. Average total suspended particle (TSP) concentrations during episode days in winter were as high as 153?±?33 ?g/m(3), and PM mass concentrations in summer were as low as one-third of that in winter. Generally, PM concentration at night was higher than that in the daytime in southern Taiwan during the sampling periods. In winter during the episode periods, the size-segregated mass distribution of PM mass concentration was mostly in the 0.32-3.2-?m range, and the PM concentration increased significantly in the range of 0.32-3.2 ?m at night. Ammonium, nitrate, and sulfate were the dominant water-soluble ionic species in PM, contributing 34-48% of TSP mass. High concentrations of ammonia (12.9-49 ?g/m(3)) and SO2 (2.6-27 ?g/m(3)) were observed in the gas precursors. The conversion ratio was high in the PM size range of 0.18-3.2 ?m both during the day and at night in winter, and the conversion ratio of episode days was 20% higher than that of non-episode days. The conversion factor was high for both nitrogen and sulfur species at nighttime, especially on episode days. PMID:23263756

Tsai, Jiun-Horng; Chang, Li-Peng; Chiang, Hung-Lung

2013-07-01

131

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

Code of Federal Regulations, 2013 CFR

... You must use results of stack tests for dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen...subpart. To demonstrate compliance for carbon monoxide, nitrogen oxides, and sulfur dioxide, see §...

2013-07-01

132

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

Code of Federal Regulations, 2013 CFR

... You must use results of stack tests for dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen...subpart. To demonstrate compliance for carbon monoxide, nitrogen oxides, and sulfur dioxide, see §...

2013-07-01

133

40 CFR 60.1780 - How are the stack test data used?  

Code of Federal Regulations, 2013 CFR

... You must use results of stack tests for dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen...subpart. To demonstrate compliance for carbon monoxide, nitrogen oxides, and sulfur dioxide, see §...

2013-07-01

134

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

135

Characterization of stack emissions from municipal refuse-to-energy systems. Final report  

SciTech Connect

Stack emissions from three municipal refuse-to-energy systems were characterized: refuse-derived fuel (RDF), mass burning (MASS), and modular (MOD). A comprehensive set of measurements was performed at each site to determine the physical and chemical properties of the particulate and gaseous stack emissions. The physical characterization included measurement of the mass concentration and size distribution of the stack particulate matter. Inorganic chemical characterization of the stack emissions included determination of the elements, anions, and compounds present in the fly ash, measurement of gaseous HCl and HF emissions, and determination of volatile trace-element levels. The characterization of organic materials in the stack emissions included specific measurements for polynuclear aromatic hydrocarbons (PAH), tetrachlorinated dibenzo-p-dioxins (TCDD) and dibenzofurans (TCDF), and aldehydes. Screening analyses were performed to provide tentative identification of organic compounds in the stack emissions.

Howes, J.E.; Kohler, D.F.; DeRoos, F.L.; Riggin, R.M.; Barbour, R.L.

1986-10-01

136

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.

137

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

138

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

Microsoft Academic Search

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

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

2009-01-01

139

Stacked CMOS SRAM cell  

NASA Astrophysics Data System (ADS)

A static random access memory (SRAM) cell with cross-coupled stacked CMOS inverters is demonstrated for the first time. In this approach, CMOS inverters are fabricated with a laser recrystallized p-channel device stacked on top of and sharing the gate with a bulk n-channel device using a modified two-polysilicon n-MOS process. The memory cell has been exercised through the write and read cycles with external signal generators while the output is buffered by an on-chip, stacked-CMOS-inverter-based amplifier.

Chen, C.-E.; Lam, H. W.; Malhi, S. D. S.; Pinizzotto, R. F.

1983-08-01

140

Continuous particulate monitoring for emission control  

SciTech Connect

An optical continuous particle monitoring system has been developed to overcome common problems associated with emissions monitoring equipment. Opacity monitors generally use a single- or double-pass system to analyze the presence of dust particles in the flue gas stream. The particles scatter and absorb light as it passes through the stack. As the particle content in the gas stream increases due to bag failure or some other problem, the amount of light that is blocked also increases. The opacity monitor compares the amount of lost light energy to the total energy of the light available and translates the signal to percentage of opacity. Opacity monitors are typically installed to meet the requirements set forth by pollution control agencies. Most opacity monitors are designed to meet all of the requirements of the Environmental Protection Agency (EPA) 40 CFR, Part 60, Appendix B, Performance Specification. The new continuous particle monitor (CPM) increases the accuracy of emission monitoring and overcomes typical problems found in conventional emission monitoring devices. The CPM is an optically based, calibratible, continuous dust monitor that uses a microprocessor, transmitter head, and receiver head. When calibrated with an isokinetic sample, a continuous readout of particulate concentration (in mg/m[sup 3]) in the exhaust gas is provided. The system can be used as a filter bag failure system or a long-term emission trend analyzer. Formal testing was conducted to evaluate the effectiveness of the optically based CPM. The monitor was calibrated using particles of a range of compositions, size distributions, and concentrations. The feasibility of using the instrument to measure particle concentration as low as 10 mg/m[sup 3] was examined.

Bock, A.H. (BHA Group, Inc., Kansas City, MO (United States))

1993-08-01

141

Nature and Magnitude of Aromatic Stacking of Nucleic Acid Bases  

SciTech Connect

This review summarises recent advances in quantum chemical calculations of base-stacking forces in nucleic acids. We explain in detail the very complex relationship between the gas-phase basestacking energies, as revealed by quantum chemical (QM) calculations, and the highly variable roles of these interactions in nucleic acids. This issue is rarely discussed in quantum chemical and physical chemistry literature. We further extensively discuss methods that are available for basestacking studies, complexity of comparison of stacking calculations with gas phase experiments, balance of forces in stacked complexes of nucleic acid bases, and the relation between QM and force field descriptions. We also review all recent calculations on base-stacking systems, including details analysis of the B-DNA stacking. Specific attention is paid to the highest accuracy QM calculations, to the decomposition of the interactions, and development of dispersion-balanced DFT methods. Future prospects of computational studies of base stacking are discussed.

Sponer, Jiri; Riley, Kevin E.; Hobza, Pavel

2008-04-07

142

Determination of phthalates and organophosphate esters in particulated material from harbour air samples by pressurised liquid extraction and gas chromatography-mass spectrometry.  

PubMed

A method based on gas chromatography-mass spectrometry (GC-MS) combined with a pressurised liquid extraction (PLE) to determine four organophosphates, seven phthalate esters and bis(2-ethylhexyl) adipate in particulated material of harbour air samples has been developed. Some studies show that these compounds may cause hormone disrupting effects on human health. Moreover, the U.S. Environmental Protection Agency (EPA) has classified benzyl butyl phthalate and di(2-ethylhexyl) phthalate as possible human carcinogens.The chromatographic time per run analysis is less than 15 min and the complete separation of all compounds is achieved. The PLE was optimised with recoveries above 90% and the repeatability of the method with real samples is less than 11% (%RSD, n=4). The MDLs (0.004-0.4 ng m(-3)) and MQLs (0.02-2 ng m(-3)) are limited by the fact of some compounds are present in low levels in sampling blank filters.The method was successfully applied in several samples and most of the compounds under study were found. The most relevant values were the high concentration of di-iso-butyl phthalate (between 28 and 529 ng m(-3)) and the significant concentration of di(2-ethylhexyl) phthalate (between MQL and 22 ng m(-3)). In addition, benzyl butyl phthalate was also detected in some samples but at low concentration levels (between MQL to 0.2 ng m(-3)). PMID:23158351

Aragón, M; Marcé, R M; Borrull, F

2012-11-15

143

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

144

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

145

40 CFR 52.2276 - Control strategy and regulations: Particulate matter.  

Code of Federal Regulations, 2010 CFR

...Texas shall install fabric filters on the primary crusher and on the secondary crusher and screens, meeting the requirements of Appendix...exhaust stack of the fabric filter on its primary crusher and shall not emit particulate matter in...

2010-07-01

146

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

147

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

148

Characterization of volatile organic compounds and odorants associated with swine barn particulate matter using solid-phase microextraction and gas chromatography–mass spectrometry–olfactometry  

Microsoft Academic Search

Swine operations can affect air quality by emissions of odor, volatile organic compounds (VOCs) and other gases, and particulate matter (PM). Particulate matter has been proposed to be an important pathway for carrying odor. However, little is known about the odor–VOCs–PM interactions. In this research, continuous PM sampling was conducted simultaneously with three collocated TEOM 1400a analyzers inside a 1000-head

Lingshuang Cai; Jacek A. Koziel; Yin-Cheung Lo; Steven J. Hoff

2006-01-01

149

Barrier RF stacking  

SciTech Connect

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

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

2004-12-01

150

Laser pulse stacking method  

DOEpatents

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

Moses, E.I.

1992-12-01

151

Urban air pollution source apportionment using a combination of aerosol and gas monitoring techniques  

Microsoft Academic Search

The dominating local and regional sources of gaseous and particulate air pollution in the city of Lund (69,000 inhabitants) in southern Sweden were characterized using a combination of aerosol and gas-phase monitoring techniques. Twelve-hour samples were taken at two stations of both fine and coarse fraction urban aerosols with a stacked filter unit during the four-week measurement campaign in March\\/April

Hans Edner

1996-01-01

152

Filtering apparatus and methods of exchanging particulate filter materials  

Microsoft Academic Search

A method for exchanging particulate filter material in a gas cleaning plant is described. The method includes means defining a gas-permeable filter compartment within which said filter material is contained, said compartment being defined with a crude gas side and a clean gas side, and means for passing gas to be cleaned through said filter compartment from said crude gas

1980-01-01

153

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.

154

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2013 CFR

...pollutant levels must be corrected for the amount of oxygen in the stack gas according to the formula: ER30SE99.027 Where: Pc is the corrected concentration of the pollutant in the stack gas, Pm is the measured concentration of the pollutant in...

2013-07-01

155

Optical Method for Measuring the Mass Concentration of Particulate Emissions.  

National Technical Information Service (NTIS)

The objective of this study is to demonstrate the feasibility of an in-situ across-the-stack optical technique to measure the mass of particulate emissions from stationary sources. The technique uses small angle light scattering and transmittance to deter...

G. R. Markowski G. J. Woffinden D. S. Ensor

1976-01-01

156

South African Particulates  

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

2013-04-16

157

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

PubMed

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

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

2009-11-01

158

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

EPA Science Inventory

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

159

30 CFR Particulate - Underground Only  

Code of Federal Regulations, 2010 CFR

...false Underground Only Particulate Diesel Particulate Matter Mineral Resources...Quality, Radiation, Physical Agents, and Diesel Particulate Matter Radiation-Underground...1995; 71 FR 16667, Apr. 3, 2006] Diesel Particulate MatterâUnderground...

2010-07-01

160

PARTICULATE MATTER RESEARCH 02  

EPA Science Inventory

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

161

Economic Evaluation of Stack Gas Desulfurization for a Power Plant Located in the Mohawk Valley Region of New York State. Final Report.  

National Technical Information Service (NTIS)

A parametric analysis was performed to determine the capital and annualized cost of flue gas desulfurization (FGD) processes for proposes coal-fired power plants located in the Mohawk Valley region of New York State. The cases considered were three 800-MW...

J. M. Genco H. S. Rosenberg

1977-01-01

162

An Economic Evaluation of Stack Gas Desulfurization for a Power Plant Located in the Mohawk Valley Region of New York State.  

National Technical Information Service (NTIS)

A parametric analysis was performed to determine the capital and annualized cost of flue gas desulfurization (FGD) processes for two alternative coal-fired power plants located in the Mohawk Valley region of New York State. The cases considered were three...

J. M. Genco H. S. Rosenberg

1977-01-01

163

Thermoacoustics with idealized heat exchangers and no stack.  

PubMed

A model is developed for thermoacoustic devices that have neither stack nor regenerator. These "no-stack" devices have heat exchangers placed close together in an acoustic standing wave of sufficient amplitude to allow individual parcels of gas to enter both exchangers. The assumption of perfect heat transfer in the exchangers facilitates the construction of a simple model similar to the "moving parcel picture" that is used as a first approach to stack-based engines and refrigerators. The model no-stack cycle is shown to have potentially greater inviscid efficiency than a comparable stack model. However, losses from flow through the heat exchangers and on the walls of the enclosure are greater than those in a stack-based device due to the increased acoustic pressure amplitude. Estimates of these losses in refrigerators are used to compare the possible efficiencies of real refrigerators made with or without a stack. The model predicts that no-stack refrigerators can exceed stack-based refrigerators in efficiency, but only for particular enclosure geometries. PMID:12083198

Wakeland, Ray Scott; Keolian, Robert M

2002-06-01

164

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

165

VLSI architecture for stack filters  

Microsoft Academic Search

A new approach to implementation of stack filtering has been suggested in the work of Astola et al. (see Proceedings of Int. Conf. on Digital Signal Processing, Limassol, Cyprus, 1995). Based on this approach, efficient algorithms and a new VLSI architecture are developed. They are fast and programmable, thus supporting adaptive stack filtering in real time. An arbitrary stack filter

D. Gevorkian; M. Hu; O. Vainio; J. Astola

1997-01-01

166

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.

2014-01-01

167

Mechanistic modeling of granular bed filters for the removal of particulate matter from high-temperature, high-pressure gas streams: a critical assessment. [61 references  

Microsoft Academic Search

In several coal conversion processes involving the generation of electrical power from coal, it is necessary to remove the particulate matter from flue gases at high temperatures and pressures. Several variants of granular bed filters involving fixed beds, moving beds, intermittently moving beds, and fluidized beds are being examined to accomplish this goal. This report deals with the review and

Saxena

1980-01-01

168

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

169

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

170

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

171

Advanced hybrid particulate collector. Quarterly technical progress report, July 1--September 30, 1996.  

National Technical Information Service (NTIS)

The objective for this quarter was to test the advanced hybrid particulate collector (AHPC) in real flue gas conditions. The initial tests were performed on the particulate test combustor (PTC) firing Absoloka subbituminous using two types of bags: PTFE a...

S. J. Miller G. L. Schelkoph

1996-01-01

172

Barrier RF stacking  

SciTech Connect

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

Weiren Chou and Akira Takagi

2003-02-24

173

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

174

Development of internal reforming carbonate fuel cell stack technology  

SciTech Connect

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

Farooque, M.

1990-10-01

175

Asymmetric Flexible Supercapacitor Stack  

NASA Astrophysics Data System (ADS)

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 AB3 alloy 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.

Leela Mohana Reddy, A.; Estaline Amitha, F.; Jafri, Imran; Ramaprabhu, S.

2008-04-01

176

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

177

Stacked reverberation mapping  

NASA Astrophysics Data System (ADS)

Over the past 20 years reverberation mapping has proved one of the most successful techniques for studying the local (<1 pc) environment of supermassive black holes that drive active galactic nuclei. Key successes of reverberation mapping have been direct black hole mass estimates, the radius-luminosity relation for the H? line and the calibration of single-epoch mass estimators commonly employed up to z ˜ 7. However, observing constraints mean that few studies have been successful at z > 0.1, or for the more-luminous quasars that make up the majority of current spectroscopic samples, or for rest-frame ultraviolet emission lines available in optical spectra of z > 0.5 objects. Previously, we described a technique for stacking cross-correlations to obtain reverberation mapping results at high z. Here, we present the first results from a campaign designed for this purpose. We construct stacked cross-correlation functions for the C IV and Mg II lines and find a clear peak in both. We find that the peak in the Mg II correlation is at longer lags than C IV consistent with previous results at low redshift. For the C IV sample, we are able to bin by luminosity and find evidence for increasing lags for more-luminous objects. This C IV radius-luminosity relation is consistent with previous studies but with a fraction of the observational cost.

Fine, S.; Shanks, T.; Green, P.; Kelly, B. C.; Croom, S. M.; Webster, R. L.; Berger, E.; Chornock, R.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Price, P. A.

2013-07-01

178

Diesel particulate control  

SciTech Connect

Diesel particulates, because of their chemical composition and extremely small size, have raised health and welfare issues. Health experts have expressed concern that they contribute to or aggravate chronic lung diseases such as asthma, bronchitis and emphysema, and there is the lingering issue about the potential cancer risk from exposure to diesel particulate. Diesel particulates impair visibility, soil buildings, contribute to structural damage through corrosion and give off a pungent odor. Diesel trucks, buses and cars together are such a significant and growing source of particulate emissions. Such vehicles emit 30 to 70 times more particulate matter than gasoline vehicles equipped with catalytic converters. Diesel engines currently power the majority of larger trucks and buses. EPA predicted that, if left uncontrolled, diesel particulate from motor vehicles would increase significantly. Diesel particulate emissions from motor vehicles are particularly troublesome because they frequently are emitted directly into the breathing zone where we work and recreate. The U.S. Congress recognized the risks posed by diesel particulate and as part of the 1977 Clean Air Act Amendments established specific, technology-forcing requirements for controlling these emissions. The U.S. Environmental Protection Agency (EPA) in 1980 established particulate standards for automobiles and light trucks and in 1985, heavy trucks and buses. California, concerned that EPA standards would not adequately protect its citizens, adopted its own set of standards for passenger cars and light trucks. This paper discusses emerging technologies proposed to address the problem.

Bertelsen, F.I. (Manufacturers of Emissions Control Association, Washington, DC (US))

1988-01-01

179

IAS Stacking Library in IDL  

NASA Astrophysics Data System (ADS)

This IDL library is designed to be used on astronomical images. Its main aim is to stack data to allow a statistical detection of faint signal, using a prior. For instance, you can stack 160um data using the positions of galaxies detected at 24um or 3.6um, or use WMAP sources to stack Planck data. It can estimate error bars using bootstrap, and it can perform photometry (aperture photometry, or PSF fitting, or other that you can plug). The IAS Stacking Library works with gnomonic projections (RA---TAN), and also with HEALPIX projection.

Bavouzet, Nicolas; Beelen, Alexandre; Bethermin, Matthieu; Dole, Herve; Ponthieu, Nicolas

2013-02-01

180

Stacked insulator induction accelerator gaps  

SciTech Connect

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

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

1997-05-01

181

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

182

Measurement of heat conduction through stacked screens.  

PubMed

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. PMID:11543366

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

1998-01-01

183

Distribution of toxic and radiation components in air particulates  

Microsoft Academic Search

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

H. Rausch; I. L. Sziklai; J. Borossay; K. Torkos; T. Rikker; É. Zemplén-Papp

1995-01-01

184

Removal of SOx, NOx, and particulate from combusted carbonaceous fuels  

Microsoft Academic Search

The invention is a method for removing sulfur oxides, nitrogen oxides and particulate from the products of combusted carbonaceous fuels. Sulfur oxides, nitrogen oxides and particulate are currently discharged to the atmosphere as flue gas in quantities highly detrimental to the environment. Potassium compounds, as are found in agricultural grade potash, are dispersed throughout the combustion products at the exit

Dayen

1985-01-01

185

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

186

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...

187

Pulse combustion drying apparatus for particulate materials  

SciTech Connect

This patent describes a pulse jet combustion apparatus for the drying of particulate material of the type having: a combustion chamber having an air entry end, an exhaust end and a common longitudinal axis therebetween, an air inlet conduit coaxially connected to the air entry and thereof, a primary exhaust gas conduit coaxially connected to the exhaust end thereof and, a tailpipe coaxially connected to the end of the exhaust gas conduit for directing the exhaust gases past a locus of particulate material introduction and to a dried particulate receiving chamber. The improvements described here comprise: primary fuel nozzles mounted at the air entry end of the combustion chamber downstream of the air inlet conduit and positioned to direct combustible fuel to a common location on the longitudinal axis of the combustion chamber spaced a predetermined distance from the air entry end thereof.

Gray, R.R.; Marguth, V.M.

1987-01-20

188

Cigarette smoke induced changes in rat pulmonary clearance of /sup 99m/TcDTPA. A comparison of particulate and gas phases  

SciTech Connect

The rat model was developed to study the effects of cigarette smoke on pulmonary clearance of 99mTcDTPA. The method developed was sufficiently noninvasive to allow frequent repeat measurements to be made with a high degree of reproducibility. Animals exposed twice daily to 90 puffs of dilute whole cigarette smoke for 7 days showed an increase in /sup 99m/TcDTPA clearance from the lung which returned to normal within 3 wk of stopping exposure. Filtration of the smoke to remove all the particulate matter abolished the changes.

Minty, B.D.; Royston, D.

1985-12-01

189

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

190

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

191

Reservoir prediction using pre-stack inverted elastic parameters  

NASA Astrophysics Data System (ADS)

This is a case study of the application of pre-stack inverted elastic parameters to tight-sand reservoir prediction. With the development of oil and gas exploration, pre-stack data and inversion results are increasingly used for production objectives. The pre-stack seismic property studies include not only amplitude verse offset (AVO) but also the characteristics of other elastic property changes. In this paper, we analyze the elastic property parameters characteristics of gas- and wet-sands using data from four gas-sand core types. We found that some special elastic property parameters or combinations can be used to identify gas sands from water saturated sand. Thus, we can do reservoir interpretation and description using different elastic property data from the pre-stack seismic inversion processing. The pre-stack inversion method is based on the simplified Aki-Richard linear equation. The initial model can be generated from well log data and seismic and geologic interpreted horizons in the study area. The input seismic data is angle gathers generated from the common reflection gathers used in pre-stack time or depth migration. The inversion results are elastic property parameters or their combinations. We use a field data example to examine which elastic property parameters or combinations of parameters can most easily discriminate gas sands from background geology and which are most sensitive to pore-fluid content. Comparing the inversion results to well data, we found that it is useful to predict gas reservoirs using ?, ??, ?/µ, and K/µ properties, which indicate the gas characteristics in the study reservoir.

Chen, Shuangquan; Wang, Shangxu; Zhang, Yonggang; Ji, Min

2009-12-01

192

Diesel particulate emission control  

Microsoft Academic Search

This paper reviews the emission control of particulates from diesel exhaust gases. The efficiency and exhaust emissions of diesel engines will be compared with those of otto engines (petrol engines). The formation of particulates (or “soot”), one of the main nuisances of diesel exhaust gases, will be briefly outlined. The effects of various emission components on human health and the

John P. A. Neeft; Michiel Makkee; Jacob A. Moulijn

1996-01-01

193

CONTROLLING EMISSIONS OF PARTICULATES  

EPA Science Inventory

The report gives a semi-technical overview of the contribution of particulate matter to the overall U.S. air pollution problem. It also discusses contributions of the Particulate Technology Branch of EPA's Industrial Environmental Research Laboratory at Research Triangle Park, N....

194

Airborne particulate discriminator  

DOEpatents

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

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

2009-08-11

195

Particulate matter fugitive dusts  

SciTech Connect

Topics covered in this conference include: Review of EPA's cost/benefit analysis for additional regulation of surface coal mines; Particulate monitoring on the Kilauea East Rift, Hawaii, and The MEDUSA sampling system: case histories in the measurement of particulate matter with wide spectrum analysis.

Not Available

1988-01-01

196

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

Code of Federal Regulations, 2013 CFR

...necessary for petroleum-fueled, natural gas-fueled and liquefied...3) For gasoline-fueled, natural gas-fueled and liquefied...Otto-cycle and petroleum-fueled, natural gas- fueled and liquefied...selected simultaneously with the selection of an empty gaseous...

2013-07-01

197

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

198

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 certer 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.

Neumeyer, C. L. [Princeton Plasma Physics Laboratory (PPPL); Peng, Yueng Kay Martin [ORNL

2002-01-01

199

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

200

Die Stacking (3D) Microarchitecture  

Microsoft Academic Search

D die stacking is an exciting new technology that in- creases transistor density by vertically integrating two or more die with a dense, high-speed interface. The result of 3D die stacking is a significant reduction of interconnect both within a die and across dies in a system. For instance, blocks within a microprocessor can be placed vertically on multiple die

Bryan Black; Murali Annavaram; Ned Brekelbaum; John Devale; Lei Jiang; Gabriel H. Loh; Don McCauley; Pat Morrow; Donald W. Nelson; Daniel Pantuso; Paul Reed; Jeff Rupley; Sadasivan Shankar; John Paul Shen; Clair Webb

2006-01-01

201

Pulse combustion drying apparatus for particulate materials  

Microsoft Academic Search

This patent describes a pulse jet combustion apparatus for the drying of particulate material of the type having: a combustion chamber having an air entry end, an exhaust end and a common longitudinal axis therebetween, an air inlet conduit coaxially connected to the air entry and thereof, a primary exhaust gas conduit coaxially connected to the exhaust end thereof and,

R. R. Gray; V. M. Marguth

1987-01-01

202

Particulate characterization for PFBC filter systems  

SciTech Connect

Southern Research Institute is participating, as a subcontractor to Southern Company Services (SCS), in METC`s project to establish a Power Systems Development Facility at Wilsonville, Alabama. This plant will serve as a facility for the development and testing of advanced systems for coal-based power generation. An important part of the program will be to test and evaluate various kinds of particulate control devices and systems for operation at high temperatures and high pressures. The hot gas cleanup technology is a critical factor in achieving the highest levels of energy efficiency in the advanced power systems. In connection with evaluation of particulate control devices to be installed at this facility, SRI has the responsibility for developing methods and equipment to characterize the particulate material suspended in the hot gas streams. Our objectives are to design systems for sampling and monitoring particulate mass loadings and size distributions at appropriate locations in the plant and to develop methods for operating these systems. We will assist SCS in the preparation of test plans for the operation of the plant, and we will participate in carrying out the particulate measurements.

Pontius, D.H.

1993-09-01

203

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

204

Corrosion and degradation of ceramic particulate filters in direct coal-fired turbine applications  

SciTech Connect

High-temperature ceramic filters show considerable promise for efficient particulate removal from coal combustion systems. Advanced coal utilization processes such as direct coal-fired turbines require particulate-free gas for successful operation. This paper describes the various ceramic particulate filters under development and reviews the degradation mechanisms expected when operated in coal combustion systems.

Sawyer, J. (Acurex Corp., Mountain View, CA (US)); Vass, R.J.; Brown, N.R.; Brown, J.J. (Center for Advanced Ceramic Materials, CIT TDC, Virginai Polytechnic Inst. and State Univ., Blacksburg, VA (US))

1991-10-01

205

Design, Fabrication, and Installation of a Particulate Aerodynamic Test Facility.  

National Technical Information Service (NTIS)

The report presents the trade-offs and design considerations, component selection criteria, and final design details for a particulate aerodynamic test facility. The design meets a range of performance specifications for the test gas, including test secti...

D. D. Blann K. A. Green L. W. Anderson

1974-01-01

206

Seismic qualification of ventilation stack  

SciTech Connect

This paper describes the method to be used to qualify the 105 K ventilation stack at the U.S. Department of Energy`s Hanford Site, near Richland, Washington, under seismic and wind loadings. The stack stands at 175 ft (53.34 m), with a diameter tapering from 22 ft (6.71 m) at the foundation to 12.83 ft (3.91 m) at the top. Although the stack is classified as Safety Class 3 (low hazard), it is treated as a Safety Class 1 (high hazard) component, as failure could damage a Safety Class 1 facility (the irradiated fuel storage basin). The evaluation used U.S. Department of Energy criteria specified in UCRL 15910 (1990). The seismic responses of the stack under earthquake loading were obtained from modal analyses with response spectrum input that used the ANSYS (1989) finite-element computer code. The moments and shear forces from the results of seismic analysis were used to qualify the reinforcement capacity of the stack structure by the ultimate-strength method. The wind forces acting on the stack in both along-wind and crosswind directions were also calculated. Presented are evaluations of the soil bearing pressure, the moment, and the shear capacity of the stack foundation.

Chen, W.W.; Huang, S.N.; Lindquist, M.R.

1993-10-01

207

Nahcolite Properties Affecting Stack Gas Pollutant Absorption.  

National Technical Information Service (NTIS)

Nahcolite, the mineral form of sodium bicarbonate, is present in vast quantities in Green River Formation oil shales of Northwestern Colorado. The total resource is about 29 billion tons. Nahcolite is being seriously considered as an SO sub 2 and NO/sub x...

J. Howatson J. W. Smith D. A. Outka H. D. Dewald

1977-01-01

208

Regenerative cyclone-type air/particulate concentrator and collector  

SciTech Connect

A cyclone-type particulate collector and concentrator is provided wherein the outlet tube is provided with a conical concentrator having its sidewalls formed of a plurality of tapered, spaced, nested, generally u-shaped and cross-section vaned members between which the gas entering the outlet tube must pass in flowing to the outlet end of the outlet tube. A portion of the sidewall of the outlet tube of the cyclone-type particulate collector is provided with a gate to act as a particulate skimmer which opens into the gas inlet volute for recirculation of the skimmed particles.

Haynes, W.R.; Truhan, A.

1981-04-07

209

Radiant zone heated particulate filter  

DOEpatents

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

Gonze, Eugene V [Pinckney, MI

2011-12-27

210

Advances in diesel particulate control  

SciTech Connect

This book contains the proceedings on advances in diesel particulate control. Topics covered include: trapping performance of diesel particulate filters, catalyst assisted regeneration system for a diesel particulate trap, the performance of an electrostatic agglomerator as a diesel soot emission control device, and regeneration capability of wall-flow monolith diesel particulate filter with electric heater.

Not Available

1990-01-01

211

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

212

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

NASA Astrophysics Data System (ADS)

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

Gadel, François; Charrière, Bruno; Serve, Léon

1993-09-01

213

A Fluidic, Stacked Mail Counter.  

National Technical Information Service (NTIS)

The feasibility of counting vertically stacked letters in standard mail racks with the use of a fluidic sensing and counting system was investigated. A description of the system, the test program conducted, and innovations employed to increase the system ...

C. E. Spyropoulos

1969-01-01

214

RF stacking without emittance dilution  

SciTech Connect

A long-established technique for accumulating high current in a storage ring is to inject additional beam off-momentum and move it into the main beam stack by rf acceleration. This procedure necessarily dilutes the longitudinal phase space density, because the rf perturbs the stack as the new beam approaches closely in momentum. For accumulators that use beam cooling to obtain a high phase space density, this perturbation may result in an unacceptable performance limitation. Using broadband rf to establish and manipulate azimuthal barriers to the motion of the stack and injected beam permits practically dilution-free longitudinal phase space stacking. The concept is described and illustrated with a detailed example which pertains to the Fermilab Recycler ring.

J. A. MacLachlan

2000-06-23

215

Edge states in stacked nanographene  

NASA Astrophysics Data System (ADS)

Nanocarbon materials are investigated intensively. In this paper, the edge-state in nanographene materials with zigzag edges is studied theoretically. In particular, while the inter-layer interactions are considered, we prove that edge states exist at the energy of the Dirac point in the doubly stacked nanographene, and in the case of the infinitely-wide lower layer case. This property applies both for the A-B and A-C stackings.

Harigaya, Kikuo

2012-12-01

216

Processors for generalized stack filters  

Microsoft Academic Search

New processor structures for generalized stack filters are proposed. They can be implemented using different numbers of Boolean function units. The class of pipeline-parallel structures for generalized stack filters is simple and modular in structure, and suitable for VLSI implementation. Coder and decoder networks are developed for the mutual transform of binary-weighted and unary-weighted codes as the thresholding and addition

D. Akopian; O. Vainio; S. Agaian; J. Astola

1995-01-01

217

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

218

Performance model of a recirculating stack nickel hydrogen cell  

NASA Astrophysics Data System (ADS)

A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for appropriate pore size distributions, and the maintenance of both convective electrolyte and gas flow paths through the stack, if the recirculating stack nickel hydrogen cell design is to work properly.

Zimmerman, Albert H.

1994-02-01

219

Performance model of a recirculating stack nickel hydrogen cell  

NASA Technical Reports Server (NTRS)

A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for appropriate pore size distributions, and the maintenance of both convective electrolyte and gas flow paths through the stack, if the recirculating stack nickel hydrogen cell design is to work properly.

Zimmerman, Albert H.

1994-01-01

220

Use and limitations of in-stack impactors. Final report  

Microsoft Academic Search

A systematic evaluation of the operating parameters for four commercially available in-stack cascade impactors was carried out with polydisperse test aerosols. Test aerosols used were polystyrene latex spheres, uranine, sodium chloride, dioctyl-phthalate, or dinonyl phthalate. The effect upon the apparent measured size distribution of each polydisperse test aerosol was noted for various gas sampling rates (flow rates), types of impactor

D. A. Lundgren; W. D. Balfour

1980-01-01

221

Finding and visualizing nucleic acid base stacking  

Microsoft Academic Search

Base stacking is one of the primary factors stabilizing nucleic acid structure. Yet, methods for locating stacking interactions in DNA and RNA are rare and methods for displaying stacking are rarer still. We present here simple, automated procedures to search nucleic acid molecules for base-base and base-oxygen stacking and to display these interactions graphically in a manner that readily conveys

H. A. Gabb; S. R. Sanghani; C. H. Robert; C. Prévost

1996-01-01

222

Enhanced flue gas conditioning study  

SciTech Connect

Many electrostatic precipitators (ESPS) do not achieve acceptable particulate removal efficiencies because of high-resistivity ash. One method to improve ESP performance is to employ chemical conditioning agents to reduce fly ash resistivity. Widely used agents include sulfur trioxide (SO[sub 3]) and ammonia, which are sometimes used simultaneously. For some fly ashes, that have a low affinity for SO[sub 3], conditioning with SO[sub 3] alone is not adequate to reduce resistivity without excessive amounts of SO[sub 3] exiting the stack. In such cases, the use of ammonia in addition to SO[sub 3] may reduce the amount of required SO[sub 3] and prevent the emission of excess SO[sub 3] out of the stack. The general objective of the work was to test enhanced flue gas conditioning methods to improve the performance of ESPS. Specific objectives were to (1) verify the relationship between the required SO[sub 3] injection rates to maintain the desired fly ash resistivity and temperature for four coals, (2) verify that dual conditioning with both ammonia and SO[sub 3] promotes SO[sub 3] utilization and allows for resistivity modification with moderate SO[sub 3] injection rates, and (3) verify the effectiveness and practicality of an enhanced flue gas conditioning (EFGC) method. The EFGC method is a proprietary development of Wahlco, Inc.

Miller, S.J.; Laudal, D.L.

1991-11-01

223

ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a manner that has not been done before. The AHPC concept consists of a combination of fabric filtration and electrostatic precipitation in the same housing, 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 collection of dust in conventional baghouses. The AHPC is currently being tested at the 2.7-MW scale at the Big Stone power station.

Stanley Miller; Rich Gebert; William Swanson

1999-11-01

224

Void/particulate detector  

DOEpatents

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

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

1985-01-01

225

Void/particulate detector  

SciTech Connect

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

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

1985-09-24

226

Split stack blowout prevention system  

SciTech Connect

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

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

1980-03-18

227

Stacked generalization and simulated evolution.  

PubMed

A stacked generalization strategy in which an evolutionary algorithm generates baselevel predictive models is described. The evolutionary algorithm incorporates model validation and an inductive ranking criterion which encourages diversity of prediction errors. Higher levels of the stack of generalizers yield predictors that work through memory-based correction and combination of predictions produced by populations of models obtained in lower levels of the stack. The strategy has been applied to the classic problem of predicting annual sunspots activity. Baselevel predictors are drawn from a class of recurrent neural networks. Normalized mean squared errors of 0.064 and 0.19 for the conventional test intervals of 1921-1955 and 1956-1979, respectively, improve upon previously published results. The strategy has also been used to accurately forecast the behaviour of a synthetic system which makes random transitions between two states of low-dimensional chaos. PMID:8735383

English, T M

1996-01-01

228

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

229

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

230

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

EPA Science Inventory

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

231

Particulate Measurement - Motorcycle Test Results.  

National Technical Information Service (NTIS)

Particulate testing has been successfully completed on two different two-stroke powered motorcycles. The results indicate that the amount of particulate material produced by motorcycles is no greater than that from light-duty diesel automobiles. This conc...

E. Danielson

1978-01-01

232

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

233

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

234

JV Task 95-Particulate Control Consulting for Minnesota Ore Operations  

SciTech Connect

The purpose of the project was to assist U.S. Steel in the evaluation, selection, planning, design, and testing of potential approaches to help meet U.S. Steel's goal for low-particulate matter emissions and regulatory compliance. The energy-intensive process for producing iron pellets includes treating the pellets in high-temperature kilns in which the iron is converted from magnetite to hematite. The kilns can be fired with either natural gas or a combination of gas and coal or biomass fuel and are equipped with wet venturi scrubbers for particulate control. Particulate measurements at the inlet and outlet of the scrubbers and analysis of size-fractionated particulate samples led to an understanding of the effect of process variables on the measured emissions and an approach to meet regulatory compliance.

Stanley Miller

2008-10-31

235

Release of polycyclic aromatic hydrocarbons, carbon monoxide and particulate matter from biomass combustion in a wood-fired boiler under varying boiler conditions  

NASA Astrophysics Data System (ADS)

Particulate matter, CO and NO as well as 16 polycyclic aromatic hydrocarbons (PAHs) in both gaseous and particulate phases were measured in the stack of a woodchip-fired 50 kW boiler used for domestic heating. The concentrations of ?PAHs in both gas and particle phases varied from 1.3 to 1631.7 ?g m -3. Mean CO and NO concentrations varied from 96 to 6002 ppm and from 28 to 359 ppm, respectively. The effects of fuel parameters (moisture content (MC) and tree species) and boiler operating conditions on pollutant concentrations were investigated. A relationship was established between ?PAHs in gaseous and particulate phases and CO concentrations. The species of tree used for woodchip was less important than MC and boiler operating conditions in affecting pollutant concentrations. It is recommended that in order to minimise PAH release woodchip fuel should have a low MC, and the boiler should be operated with a load demand (high/moderate heat requirement). Slumber modes when the boiler has no load demand and is effectively a smouldering flame should be avoided. This can be achieved by increasing automatic operation capability of wood-fired boilers, for example, by automatically varying fire rates and having auto-start capabilities. The PAH data obtained from this study is particularly useful in contributing to emissions inventories, modelling, and predictions of ambient air quality.

Bignal, Keeley L.; Langridge, Sam; Zhou, John L.

236

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...

237

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

238

Void/Particulate Detector.  

National Technical Information Service (NTIS)

Apparatus for detecting voids and particulates in a flowing stream of fluid contained in a pipe may comprise: (a) a transducer for transmitting an ultrasonic signal into the stream, coupled to the pipe at a first location; (b) a second transducer for dete...

T. N. Claytor H. B. Karplus

1983-01-01

239

Health Effects of Particulate Matter  

NSDL National Science Digital Library

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

Agency, Environmental P.

240

Electrodialysis Membrane Stack MS 3070.  

National Technical Information Service (NTIS)

Design, operation and assembly of the electrodialysis membrane stack are described. The main element is a new sealing frame which, when coupled with a suitable net spacer, yields a good flow distribution in the cells and largely prevents internal and exte...

K. Kneifel K. Hattenbach U. Martens

1985-01-01

241

Progress Update: Stack Project Complete  

ScienceCinema

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

242

STACK SAMPLING FOR ORGANIC EMISSIONS  

EPA Science Inventory

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

243

Progress Update: Stack Project Complete  

SciTech Connect

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

2010-01-01

244

POLYMERIC INTERFACES FOR STACK MONITORING  

EPA Science Inventory

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

245

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

246

True-amplitude single-stack redatuming  

NASA Astrophysics Data System (ADS)

Based on the chaining of diffraction-stack migration and isochron-stack demigration, we derive a general true-amplitude Kirchhoff-type single-stack operator for 3D and 2.5D redatuming. It consists of performing a single weighted stack along adequately chosen stacking surfaces or lines. The corresponding traveltimes and weight functions can be calculated using quantities obtained from dynamic ray tracing. The operator simplifies when specified for zero-offset data. For simple types of media, we derive analytic expressions for the stacking lines and weight functions and demonstrate their functionality with numerical examples.

Pila, Matheus F.; Schleicher, Jörg; Novais, Amélia; Coimbra, Tiago A.

2014-06-01

247

Manifold seal structure for fuel cell stack  

DOEpatents

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

Collins, William P. (South Windsor, CT)

1988-01-01

248

Determination of N-nitrosamines and nicotine in air particulate matter samples by pressurised liquid extraction and gas chromatography-ion trap tandem mass spectrometry.  

PubMed

N-nitrosamines are potentially hazardous pollutants, classified as probable carcinogenic and mutagenic by the U.S. Environmental Protection Agency (EPA). In this paper, the presence of these pollutants was studied in air samples taken at different locations of Tarragona (urban and harbour). As a result, a reliable method has been developed for determining N-nitrosamines and nicotine based on pressurised liquid extraction (PLE) and gas chromatography-(chemical ionisation) ion trap tandem mass spectrometry (GC-(CI)MS/MS). The chromatographic analysis enables the determination of these compounds in less than 13 min with total separation and good resolution between the compounds. Recovery values were higher than 80% for most of the compounds and the repeatability of the method was under 18% (5 ng m(-3), %RSD, n=4). MDLs were between 0.1 ng m(-3) (NMor and NPip) and 2 ng m(-3) (NMEA). NMor, NPyr, NPip and nicotine were the most frequent compounds in urban and harbour samples at concentration levels between 0.3 ng m(-3) (NPyr) and 12.5 ng m(-3) (nicotine) and between 0.13 ng m(-3) (NPyr) and 3.8 ng m(-3) (nicotine), respectively. PMID:24054680

Aragón, M; Marcé, R M; Borrull, F

2013-10-15

249

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

250

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

NASA Astrophysics Data System (ADS)

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.

1981-05-01

251

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

252

Gas cleaning apparatus  

Microsoft Academic Search

A description is given of an apparatus and method for removing very finely divided alkali fumes and other particulate material from a coal-gasifier make-gas comprising the introduction of char granules into the constricted passage of a venturi-shaped gas duct to adsorb the very fine particulate from the make-gas flowing therethrough, and centrifugally separating the fume-laden char granules from the make-gas.

R. H. Boll; W. C. Lapple

1980-01-01

253

Gas cleaning apparatus  

SciTech Connect

A description is given of an apparatus and method for removing very finely divided alkali fumes and other particulate material from a coal-gasifier make-gas comprising the introduction of char granules into the constricted passage of a venturi-shaped gas duct to adsorb the very fine particulate from the make-gas flowing therethrough, and centrifugally separating the fume-laden char granules from the make-gas.

Boll, R.H.; Lapple, W.C.

1980-03-04

254

Rigid particulate matter sensor  

DOEpatents

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

Hall, Matthew (Austin, TX) [Austin, TX

2011-02-22

255

Void/particulate detector  

DOEpatents

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

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

1983-09-26

256

ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and recollection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hour parametric tests and 100-hour proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency.

Stanley J. Miller; Grant L. Schelkoph; Grant E. Dunham

2000-12-01

257

Fire extinguishing attachment for chimney stacks  

Microsoft Academic Search

A fire extinguishing attachment including a bracket for mounting on a stove stack and having a tubular guide therethrough. The tubular guide is an elbow tube having an inner end within the stack directed towards the chimney flue and an outer end outside the stack adapted to receive the nozzle of a powder type fire extinguisher. When a chimney fire

Sawtelle

1984-01-01

258

Anomaly Detection Using Call Stack Information  

Microsoft Academic Search

The call stack of a program execution can be a very good information source for intrusion detection. There is no pri or work on dynamically extracting information from call stack and effectively using it to detect exploits. In this paper, w e propose a new method to do anomaly detection using call stack information. The basic idea is to extract

Henry Hanping Feng; Oleg M. Kolesnikov; Prahlad Fogla; Wenke Lee; Weibo Gong

2003-01-01

259

COMMENTS ON STACKING FAULT ENERGY OF THORIUM  

Microsoft Academic Search

Transmission electron microscopic studies were made of foils made from ; cold-rolled thorium sheet. Tangled dislocations forming a crude cell structure ; were observed, but no fringes characteristic of stacking faults were visible. No ; example of cross-slip was observed. The results suggest that thorium has an ; intermediate stacking fault energy. The interpretation of stacking fault ; probability as

J. O. Stiegler; C. J. McHargue

1963-01-01

260

Stacking faults in Si nanocrystals  

SciTech Connect

Si nanocrystals (Si nc) were formed by the implantation of Si{sup +} into a SiO{sub 2} film on (100) Si, followed by high-temperature annealing. High-resolution transmission electron microscopy has been used to examine the microstructure of the Si nc produced by a high-dose (3x10{sup 17} cm{sup -2}) implantation. It is shown that there are only stacking-fault (SF) defects in some nanocrystals; while in others the stacking faults (SFs) coexist with twins. Two kinds of SFs, one being an intrinsic SF, the other being an extrinsic SF, have been observed inside the Si nc. More intrinsic SFs have been found in the Si nc, and the possible reasons are discussed. These microstructural defects are expected to play an important role in the light emission from the Si nc.

Wang, Y.Q.; Smirani, R.; Ross, G.G. [INRS-EMT, 1650, Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2 (Canada)

2005-05-30

261

Solvent influence on base stacking.  

PubMed Central

In this paper we present a detailed analysis of the base-stacking phenomenon in different solvents, using nanosecond molecular dynamics simulations. The investigation focuses on deoxyribo- and ribodinucleoside monophosphates in aqueous and organic solutions. Organic solvents with a low dielectric constant, such as chloroform, and solvents with intermediate dielectric constants, such as dimethyl sulfoxide and methanol, were analyzed. This was also done for water, which is highly polar and has a high dielectric constant. Structural parameters such as the sugar puckering and the base-versus-base orientations, as well as the energetics of the solute-solvent interactions, were examined in the different solvents. The obtained data demonstrate that base stacking is favored in the high dielectric aqueous solution, followed by methanol and dimethyl sulfoxide with intermediate dielectric constants, and chloroform, with a low dielectric constant.

Norberg, J; Nilsson, L

1998-01-01

262

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

263

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

264

Precision Cosmography with Stacked Voids  

NASA Astrophysics Data System (ADS)

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-Paczy?ski (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; Wandelt, Benjamin D.

2012-08-01

265

SBNR processor for stack filters  

Microsoft Academic Search

The signed binary number representation (SBNR) is used to reduce the number of PBF calculation stages in stack filters. The approach is based on the possibility of minimization of signed power-of-two terms in the SBNR representation of input data. A coder and a decoder for the mutual transformation of binary-weighted code and the minimal SBNR are proposed. An efficient algorithm

David A. Akopian; Olli Vainio; Sos S. Agaian; Jaakko T. Astola

1997-01-01

266

Partitioning of metal species during an enriched fuel combustion experiment. speciation in the gaseous and particulate phases.  

PubMed

Combustion processes are the most important source of metal in the atmosphere and need to be better understood to improve flue gas treatment and health impact studies. This combustion experiment was designed to study metal partitioning and metal speciation in the gaseous and particulate phases. A light fuel oil was enriched with 15 organometallic compounds of the following elements: Pb, Hg, As, Cu, Zn, Cd, Se, Sn, Mn, V, Tl, Ni, Co, Cr, and Sb. The resulting mixture was burnt in a pilot-scale fuel combustion boiler under controlled conditions. After filtration of the particles, the gaseous species were sampled in the stack through a heated sampling tube simultaneously by standardized washing bottles-based sampling techniques and cryogenically. The cryogenic samples were collected at -80 degrees C for further speciation analysis by LT/GC-ICPMS. Three species of selenium and two of mercury were evidenced as volatile species in the flue gas. Thermodynamic predictions and experiments suggest the following volatile metal species to be present in the flue gas: H2Se, CSSe, CSe2, SeCl2, Hg(0), and HgCl2. Quantification of volatile metal species in comparison between cryogenic techniques and the washing bottles-based sampling method is also discussed. Concerning metal partitioning, the results indicated that under these conditions, at least 60% (by weight) of the elements Pb, Sn, Cu, Co, Tl, Mn, V, Cr, Ni, Zn, Cd, and Sb mixed to the fuel were found in the particulate matter. For As and Se, 37 and 17%, respectively, were detected in the particles, and no particulate mercury was found. Direct metal speciation in particles was performed by XPS allowing the determination of the oxidation state of the following elements: Sb(V), Tl(III), Mn(IV), Cd(II), Zn(II), Cr(III), Ni(II), Co(II), V(V), and Cu(II). Water soluble species of inorganic Cr, As, and Se in particulate matter were determined by HPLC/ICP-MS and identified in the oxidation state Cr(III), As(V), and Se(IV). PMID:15112832

Pavageau, Marie-Pierre; Morin, Anne; Seby, Fabienne; Guimon, Claude; Krupp, Eva; Pécheyran, Christophe; Poulleau, Jean; Donard, Olivier F X

2004-04-01

267

Fine particulate matter (PM) and organic speciation of fireplace emissions  

SciTech Connect

This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an ongoing project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory-built fireplaces. RWC wood smoke particles <10 {micro}m (PM10) consist primarily of a mixture of organic compounds that have condensed into droplets; therefore, the size distribution and total mass are influenced by temperature of the sample during its collection. During the series 1 tests (15 tests), the dilution tunnel used to cool and dilute the stack gases gave an average mixed gas temperature of 47.3 C and an average dilution ration of 4.3. Averages for the PM2.5 (particles <2.5 {micro}m) and PM10 fractions were 74 and 84%, respectively. For the series 2 tests, the dilution tunnel was modified, reducing the average mixed gas temperatures to 33.8 C and increasing the average dilution ratio to 11.0 in tests completed to date. PM2.5 and PM10 fractions were 83 and 91%, respectively. Since typical winter-time mixed gas temperatures would usually be less than 10 C, these size fraction results probably represent the lower bound; the PM10 and PM2.5 size fraction results might be higher at typical winter temperatures. The particles collected on the first stage were light gray and appeared to include inorganic ash. Particles collected on the remainder of the stages were black and appeared to be condensed organics because there was noticeable lateral bleeding of the collected materials into the filter substrate. Total particulate emission rates ranged from 10.3 to 58.4 g/h; corresponding emission factors ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide range of Environmental Protection Agency (EPA) Method 8270 semivolatile organic compounds were found in the emissions; of the 17 target compounds quantified, major constituents are phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, and naphthalene.

Purvis, C.R.; McCrillis, R.C.; Kariher, P.H.

2000-05-01

268

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

269

Application of direct thermal desorption gas chromatography time-of-flight mass spectrometry for determination of nonpolar organics in low-volume samples from ambient particulate matter and personal samplers.  

PubMed

Direct thermal desorption and in-situ derivatization thermal desorption methods in conjunction with gas chromatography time-of-flight mass spectrometry have been characterized and evaluated for analysis of trace components from filters loaded with ambient particulate matter (PM). The limits of quantification were in the range of 7-24 pg for n-alkanes, 20 pg for hopanes, and 4-22 pg for polycyclic aromatic hydrocarbons (PAH). The limit of quantification was defined as the minimum amount of substance that conforms to the minimum distinguishable signal plus 9 times the standard deviation of this background signal from PM-loaded filters. The method has been successfully applied to low-volume samples from ambient PM collected with stationary and personal samplers. Stationary samples were collected in winter 2008 and 2010 in Augsburg, Germany. Sample aliquots of 0.2-0.3 m³ from stationary sampling were analyzed. High diurnal variation in concentration and source contribution was found especially during periods with low wind speed and low mixing layer height. High contributions of solid fuel combustion (wood and coal) were found in evening and nighttime samples, leading to peak PAH concentrations at midnight more than 10 times higher than at noon. Finally, the method was applied to samples collected by means of a personal sampler, i.e. a micro aethalometer, in Xi'an, China. Quantitative data on n-alkanes, hopanes, and PAH were obtained from sample volumes of 17 and 24 l. The impact of different sources such as vehicular and biogenic emissions could be distinguished. PMID:22086458

Schnelle-Kreis, Jürgen; Orasche, Jürgen; Abbaszade, Gülcin; Schäfer, Klaus; Harlos, David P; Hansen, Anthony D A; Zimmermann, Ralf

2011-12-01

270

Particulate silicon nitride-based composites  

SciTech Connect

In an attempt to optimize the structure and properties of silicon nitride ceramics, a variety of novel processing techniques and materials compositions have evolved over the last 15 years. Among the most important, was the development of various silicon nitride-based composites. A review of particulate, silicon nitride-based composites other than whisker- or platelets-reinforced, is presented. Materials based on silicon nitride and SiALONs, with additions of carbides, nitrides and borides of transition metals are described. Special emphasis is placed on TiN- and TiC-containing ceramics. The manufacture of composites by hot pressing, reaction sintering, pressureless and gas-pressure sintering is discussed. The data on properties, including conductivity, density, Young`s modulus, strength, fracture toughness, hardness, thermal expansion, wear, creep and oxidation resistance are presented. Analysis of actual and potential uses of the selected composites demonstrates that the particulate composites are very promising as tool, structural and electronic materials. 119 refs.

Gogotsi, Y.G. [Tokyo Institute of Technology, Yokohama (Japan)

1994-05-01

271

Respiratory symptoms, lung function and particulate matter pollution in residential indoor environment in Ile-Ife, Nigeria  

PubMed Central

Introduction: Particulate air pollution is associated with increased incidence of respiratory symptoms and decreased pulmonary, function but the relative impact of pollution from different domestic energy sources is not well-known or studied. Aim: The study was aimed at assessing the association between particulate concentrations, respiratory symptoms and lung function. Materials and Methods: It was a cross-sectional study comprised of randomly selected residents of three communities. These communities were selected according to the predominant type of fuel used for household cooking which were: firewood, kerosene and liquefied petroleum gas (LPG). Assessment of the indoor PM10 levels was done by filtration using the Gent stacked filter unit sampler for collection of atmospheric aerosol in two size fractions (PM2.5 and PM10). The Medical Research Council (MRC) questionnaire was administered followed by spirometry test. Results: The mean PM10 concentration in participants using LPG, kerosene and firewood was 80.8 ± 9.52 ?g/m3, 236.9 ± 26.5 ?g/m3 and 269 ±93.7 ?g/m3, respectively. The mean age and height-adjusted percent predicted forced expiratory volumes in 1 s (FEV1) for men were 127 ± 7, 109 ± 40 and 91 ± 20 and for women were 129 ± 13, 115 ± 14, 100 ± 14 in users of LPG, kerosene and firewood, respectively. A similar trend was found in the forced vital capacity (FVCs). Users of firewood had significantly lower FEV1 and FVC compared with LPG users (P < 0.05). The participants using firewood had the highest prevalence of pulmonary and non-pulmonary symptoms (57.1%), whereas subjects using LPG had the lowest (23.8%). Conclusion: There are high levels of particulate matter pollutions with respiratory effects in residential indoor environments in Ile-Ife, Nigeria

Ibhafidon, Lawrence I.; Obaseki, Daniel O.; Erhabor, Gregory E.; Akor, Alexander A.; Irabor, Iziegbe; Obioh, IB

2014-01-01

272

Lightweight Stacks of Direct Methanol Fuel Cells  

NASA Technical Reports Server (NTRS)

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

Narayanan, Sekharipuram; Valdez, Thomas

2004-01-01

273

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

274

Finding and visualizing nucleic acid base stacking.  

PubMed

Base stacking is one of the primary factors stabilizing nucleic acid structure. Yet, methods for locating stacking interactions in DNA and RNA are rare and methods for displaying stacking are rarer still. We present here simple, automated procedures to search nucleic acid molecules for base-base and base-oxygen stacking and to display these interactions graphically in a manner that readily conveys both the location and the quality of the interaction. The method makes no a priori assumptions about relative base positions when searching for stacking, nor does it rely on empirical energy functions. This is a distinct advantage for two reasons. First, the relative contributions of the forces stabilizing stacked bases are unknown. Second, the electrostatic and hydrophobic components of base stacking are both poorly defined by existing potential energy functions. PMID:8744567

Gabb, H A; Sanghani, S R; Robert, C H; Prévost, C

1996-02-01

275

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

276

The effect of diesel fuel sulfur content on particulate matter emissions for a nonroad diesel generator.  

PubMed

The effect of sulfur content on diesel particulate matter (DPM) emissions was studied using a diesel generator (Generac Model SD080, rated at 80 kW) as the emission source to simulate nonroad diesel emissions. A load simulator was used to apply loads to the generator at 0, 25, 50, and 75 kW, respectively. Three diesel fuels containing 500, 2100, and 3700 ppm sulfur by weight were selected as generator fuels. The U.S. Environmental Protection Agency sampling Method 5 "Determination of Particulate Matter Emissions from Stationary Sources" together with Method 1A "Sample and Velocity Traverses for Stationary Sources with Small Stacks or Ducts" was adopted as a reference method for measurement of the exhaust gas flow rate and DPM mass concentration. The effects of various parameters on DPM concentration have been studied, such as fuel sulfur contents, engine loads, and fuel usage rates. The increase of average DPM concentrations from 3.9 mg/Nm3 (n cubic meter) at 0 kW to 36.8 mg/Nm3 at 75 kW is strongly correlated with the increase of applied loads and sulfur content in the diesel fuel, whereas the fuel consumption rates are only a function of applied loads. An empirical correlation for estimating DPM concentration is obtained when fuel sulfur content and engine loads are known for these types of generators: Y = Zm(alphaX + beta), where Y is the DPM concentration, mg/m3, Z is the fuel sulfur content, ppm(w) (limited to 500-3700 ppm(w)), X is the applied load, kW, m is the constant, 0.407, alpha and beta are the numerical coefficients, 0.0118 +/- 0.0028 (95% confidence interval) and 0.4535 +/- 0.1288 (95% confidence interval), respectively. PMID:16111139

Saiyasitpanich, Phirun; Lu, Mingming; Keener, Tim C; Liang, Fuyan; Khang, Soon-Jai

2005-07-01

277

CAPSULE REPORT: PARTICULATE CONTROL BY FABRIC FILTRATION ON COAL-FIRED INDUSTRIAL BOILERS  

EPA Science Inventory

Interest in fabric filtration for boiler particulate control has increased due to the conversion of oil- and gas- to coal-fired boilers and the promulgation of more stringent particulate emission regulations. his report describes the theory, applications, performance, and economi...

278

Measurement, Analysis, and Modeling of Fine Particulate Matter in Eastern North Carolina  

Microsoft Academic Search

An analysis of fine particulate data in eastern North Carolina was conducted to investigate the impact of the hog industry and its emissions of ammonia into the atmosphere. The fine particulate data are simulated using ISORROPIA, an equilibrium thermodynamic model that simulates the gas and aerosol equilibrium of inorganic atmospheric species. The observational data analyses show that the major constituents

Stephen Goetz; Viney P. Aneja; Yang Zhang; Dallas Burtraw; Karen Palmer; Juha Siikamaki; S. Arya; D.-S. Kim; Ian Rumsey; H. L. Arkinson; H. Semunegus; K. S. Bajwa; D. A. Dickey; L. A. Stefanski; L. Todd; K. Mottus; W. P. Robarge; C. M. Williams; Carsten Skjøth; Thomas Ellermann; Ole Hertel; Steen Gyldenkærne; Mette Mikkelsen; Susan Schiffman; Brevick Graham; Chris Henry; Peter Watts; Peter Nicholas; Yael Laor; Jacek Koziel; Lingshuang Cai; Uzi Ravid; Chris Occhipinti; William Showers; Dev Niyogi; Linda Geiser; Anne Ingersoll; Andrzej Bytnerowicz; Scott Copeland; Stefania Korontzi; Jessica McCarty; Christopher Justice; Semra Tuncel; Nur Oztas; M. Erduran

2008-01-01

279

Semiempirical study of perturbations of the landé g factors of electronic-vibrational-rotational levels of hydrogen: IV. The I 1?<Stack> g - Stack>, R 1?<Stack> g - Stack>, J 1?<Stack> g - Stack>, and S 1?<Stack> g - Stack> states of the H2 and D2 molecules  

NASA Astrophysics Data System (ADS)

Values of the Landé g factors are obtained for the first time for rovibronic levels of the (3d)J 1?<Stack> g - Stack> state of the D2 molecule and of the (4d)S 1?<Stack> g - Stack> state of the H2 and D2 molecules. Semiempirical values of these quantities are obtained for the first time for the (4d)R 1?<Stack> g - Stack> state of the H2 molecule and the (3d)I 1?<Stack> g - Stack> and (4d)R 1?<Stack> g - Stack> states of the D2 molecule. These values are determined in terms of the nonadiabatic model, which takes into account the interaction between the nd?1?g and nd?1?g (n = 3 and 4) states in the approximation of pure precession, with the use of the semiempirical values obtained by us for the expansion coefficients of wave functions in the adiabatic basis functions and the results of our numerical calculation of overlap integrals of the vibrational wave functions of these states. The values thus obtained are in good agreement with the data available in the literature. It is found that the interference effects of coupling of the nd?1?g and nd?1?g states lead to significant perturbations of the dependences of the g factors of vibronic levels on the rotational quantum number as compared to the adiabatic results. These perturbations are regular (reaching a factor of nine) for the I 1?<Stack> g - Stack> and R 1?<Stack> g - Stack> states and irregular (reaching a factor of 50) for the J 1?<Stack> g - Stack> and S 1?<Stack> g - Stack> states. The nonadiabatic values of g factors obtained in our previous studies for the H2, HD, and D2 molecules in the i 3?<Stack> g - Stack> and j 3?<Stack> g - Stack> states are improved by an additional inclusion of adiabatic effects. It is established that the effect of the electron spin on the g factor values for rovibronic levels of the 3d?<Stack> g - Stack> states is significant and reaches 25% for H2 and 130% for D2.

Astashkevich, S. A.

2007-02-01

280

Pilot indoor-outdoor study of organic particulate matter and particulate mutagenicity  

SciTech Connect

Elevated indoor concentrations of a number of gaseous and particulate pollutants have been demonstrated by numerous workers. The case of indoor to outdoor (I/O) relationships for particulate organic matter, however, is especially complex in view of the range of organic compounds in this fraction and the need for relatively sensitive analytical techniques and large sampled air volumes. Thus, it is not surprising that relatively little attention has been given to the characterization of particulate organic matter indoors. Indoor sources of organic pollutants, such as tobacco smoke, fireplaces and woodburning stoves, kerosene heaters, gas stoves, cooking, and attached garages may constitute the foremost air pollution hazard in some homes, depending upon season. Infiltration of outdoor organics would depend upon season and the lifestyle of the inhabitants. The pilot study reported here addresses: certain quantitative and qualitative summertime I/O relationships among selected airborne particulate organic pollutants, the I/O relationships for the bacterial mutagenicity of the extractable organic matter,and the nature of the EOM found in a home without central air conditioning during the summertime, which is a situation that can occur in many northern cities.

Lioy, P.J.; Avdenko, M.; Harkov, R.; Atherholt, T.; Daisey, J.M.

1985-06-01

281

Numerical model of particulate transport.  

National Technical Information Service (NTIS)

The transport of particulate matter occurs in a variety of physical systems. We describe a statistical model of particulate transport that can be used to simulate these systems. The physical particles are represented by a set of computational packets of p...

L. D. Cloutman

1991-01-01

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

?-? stacking tackled with density functional theory  

Microsoft Academic Search

Through comparison with ab initio reference data, we have evaluated the performance of various density functionals for describing\\u000a ?-? interactions as a function of the geometry between two stacked benzenes or benzene analogs, between two stacked DNA bases,\\u000a and between two stacked Watson–Crick pairs. Our main purpose is to find a robust and computationally efficient density functional\\u000a to be used

Marcel Swart; Tushar van der Wijst; Célia Fonseca Guerra; F. Matthias Bickelhaupt

2007-01-01

284

Sorting with Complete Networks of Stacks  

Microsoft Academic Search

Knuth introduced the problem of sorting numbers using a sequence of stacks. Tarjan extended this idea to sorting with acyclic\\u000a networks of stacks (and queues), where items to be sorted move from a source through the network to a sink while they may\\u000a be stored temporarily at nodes (the stacks). Both characterized which permutations are sortable this way; but they

Felix G. König; Marco E. Lübbecke

2008-01-01

285

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

286

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

287

Inductively heated particulate matter filter regeneration control system  

DOEpatents

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

288

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...

289

Wireless zoned particulate matter filter regeneration control system  

Microsoft Academic Search

An assembly includes a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and multiple zones. An absorbing layer absorbs microwave energy in one of N frequency ranges and is arranged with the upstream end. N is an integer. A frequency selective filter has M frequency selective segments and receives microwave energy in

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

2011-01-01

290

Smog and particulate collection system for use on vehicles with internal combustion engines  

SciTech Connect

This patent describes a method of treating exhaust gases emitted from an internal combustion engine; the internal combustion engine being coupled to a fuel tank which is capable of holding a derivative of petroleum and being mounted on a vehicle. It comprises transporting the exhaust gases from an exhaust gas manifold coupled to the internal combustion engine to an air intake; accelerating the exhaust gases by conveying the exhaust gases from the air intake to an air cyclone accelerator; separating a particulate from the exhaust gases using a spiral vortex separation column connected to the air cyclone accelerator; collecting and storing the particulate in a particulate storage tank coupled to the spiral vortex separation column and mounted on the vehicle; and recycling the particulate periodically by removing the particulate from the particulate storage tank when the fuel tank needs refilling.

Barry, W.R.

1992-04-07

291

Stacked graphs--geometry & aesthetics.  

PubMed

In February 2008, the New York Times published an unusual chart of box office revenues for 7500 movies over 21 years. The chart was based on a similar visualization, developed by the first author, that displayed trends in music listening. This paper describes the design decisions and algorithms behind these graphics, and discusses the reaction on the Web. We suggest that this type of complex layered graph is effective for displaying large data sets to a mass audience. We provide a mathematical analysis of how this layered graph relates to traditional stacked graphs and to techniques such as ThemeRiver, showing how each method is optimizing a different "energy function". Finally, we discuss techniques for coloring and ordering the layers of such graphs. Throughout the paper, we emphasize the interplay between considerations of aesthetics and legibility. PMID:18988970

Byron, Lee; Wattenberg, Martin

2008-01-01

292

Analysis of stacked rotated gratings  

NASA Astrophysics Data System (ADS)

We study the rigorous design and analysis of stacked rotated gratings (SRGs) for novel photonic devices. A concept of sampling frequency is proposed to systematically design SRGs. With the help of a rectangular sampling lattice, we extend the standard 3D rigorous coupled-wave analysis (RCWA) algorithm to the analysis of SRGs. The resultant SRG-RCWA algorithm can be used to exactly analyze SRGs that have grating parameters that match the Fourier expansion represented by the sampling lattice. SRGs that do not fall in this category can often still be closely approximated with our approach. The SRG-RCWA algorithm has been successfully applied to the characterization of two fabricated SRGs that are designed to function as circular polarization filters for an IR imaging polarimetry system. The agreement between numerical SRG-RCWA results and experimental measurements demonstrates its validity and usefulness.

Jiang, Jianhua; Deguzman, Panfilo C.; Nordin, Gregory P.

2007-03-01

293

Operational problems associated with the use of particulate emission control for MACT compliance applications.  

National Technical Information Service (NTIS)

Tests of high-efficiency particulate air filters were requested following catastrophic failure of a filter by hydrogen fluoride gas from improper operation in a production line. Operational lives in hydrogen fluoride environments of high-efficiency partic...

J. A. Compton

1992-01-01

294

Magnetic characterization of airborne particulates  

NASA Astrophysics Data System (ADS)

Burning fossil fuels from vehicles, domestics, industries and power plants in the large urban or industrial areas emit significant quantity of anthropogenic particulates which become a potential threat to human health. Here, we present temporal variability of particulate pollution associated with compositional differences, using magnetic measurements and electron microscopic observations. Six different grain-sizes of airborne particulates have been collected by filtering from 10 precipitation events in Seoul, Korea from February 2009 to June 2009. Magnetic concentration proxies show relatively better (R2 >0.6) and poorer correlations (R2 <0.3) with the masses of samples filtered by >0.45 ?m and <0.45 ?m sizes, respectively, suggesting the usefulness of magnetic characterization for the >0.45 ?m particulates. Temporally, magnetic concentrations are higher in the cold season than the warm season. In particular, a significant increase of magnetic concentration is observed in 3 ?m and 1 ?m filters after the Chinese wind-blown dust events, indicating additional influx of fine-grained anthropogenic particulates into Seoul. Microscopic observations identify that increase of magnetic concentration is highly linked with the frequent occurrence of combustion derived particulates (i.e., carbon and/or sulfur mixed particles) than natural alumino-silicates. Overall, the present study demonstrates that magnetic measurements efficiently reflect the concentration of particulates produced from fossil-fuel combustion among the airborne particles from various sources.

Kim, W.; Doh, S.; Yu, Y.

2010-12-01

295

Advanced hot gas filter development.  

National Technical Information Service (NTIS)

Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the fil...

E. S. Connolly G. D. Forsythe

1998-01-01

296

Surface and Interface Chemistry for Gate Stacks on Silicon  

NASA Astrophysics Data System (ADS)

This chapter addresses the fundamental silicon surface science associated with the continued progress of nanoelectronics along the path prescribed by Moore's law. Focus is on hydrogen passivation layers and on ultrathin oxide films encountered during silicon cleaning and gate stack formation in the fabrication of metal-oxide-semiconductor field-effect transistors (MOSFETs). Three main topics are addressed. (i) First, the current practices and understanding of silicon cleaning in aqueous solutions are reviewed, including oxidizing chemistries and cleans leading to a hydrogen passivation layer. The dependence of the final surface termination and morphology/roughness on reactant choice and pH and the influence of impurities such as dissolved oxygen or metal ions are discussed. (ii) Next, the stability of hydrogen-terminated silicon in oxidizing liquid and gas phase environments is considered. In particular, the remarkable stability of hydrogen-terminated silicon surface in pure water vapor is discussed in the context of atomic layer deposition (ALD) of high-permittivity (high-k) gate dielectrics where water is often used as an oxygen precursor. Evidence is also provided for co-operative action between oxygen and water vapor that accelerates surface oxidation in humid air. (iii) Finally, the fabrication of hafnium-, zirconium- and aluminum-based high-k gate stacks is described, focusing on the continued importance of the silicon/silicon oxide interface. This includes a review of silicon surface preparation by wet or gas phase processing and its impact on high-k nucleation during ALD growth, and the consideration of gate stack capacitance and carrier mobility. In conclusion, two issues are highlighted: the impact of oxygen vacancies on the electrical characteristics of high-k MOS devices, and the way alloyed metal ions (such as Al in Hf-based gate stacks) in contact with the interfacial silicon oxide layer can be used to control flatband and threshold voltages.

Frank, M. M.; Chabal, Y. J.

297

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

298

Stacked subsea templates accelerate deepwater development  

SciTech Connect

This paper reports on a deepwater project that can be brought on-line more quickly because of stackable drilling and production templates. Historically, one of the primary barriers to the economic development of deepwater reserves has been the long lead time from discovery to first production. Typically, production facilities must be built and often installed before development wells are drilled. The use of three-slot drilling templates allows development drilling to proceed while the production templates, Christmas trees, flow lines, and production platform are constructed. Thus, the time from initial investment to first revenue reduced. Enserch Exploration Inc., along with partners Petrofina Delaware Inc. and AGIP Petroleum, is using a piggy-back or transportable stacked template system to develop deepwater gas reserves in Mississippi Canyon Block 441, approximately 50 miles south of Grand Isle, La. The discovery is located in 1,410-1,520 ft of water. The Louisiana Offshore Oil Port (LOOP) safety fairway running north to south covers the eastern three fourths of Mississippi Canyon Block 441 and rules out surface production facilities over the well locations.

Ramsey, J.F.; Blincow, R.M.; Pickard, R.D. (Enserch Exploration Inc., Dallas, TX (US))

1991-10-21

299

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

300

Opacity of Nitrogen Dioxide Stack Plumes.  

National Technical Information Service (NTIS)

Removal of the NO sub 2 from process off-gases would enable the Purex Plant to comply with the opacity standards for air pollution control. However, a relationship between stack opacity and NO sub 2 content of the stack gases is needed in order to impleme...

C. J. Evoniuk

1979-01-01

301

Thyristor stack for pulsed inductive plasma generation  

Microsoft Academic Search

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

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

2009-01-01

302

?-? stacking tackled with density functional theory  

PubMed Central

Through comparison with ab initio reference data, we have evaluated the performance of various density functionals for describing ?-? interactions as a function of the geometry between two stacked benzenes or benzene analogs, between two stacked DNA bases, and between two stacked Watson–Crick pairs. Our main purpose is to find a robust and computationally efficient density functional to be used specifically and only for describing ?-? stacking interactions in DNA and other biological molecules in the framework of our recently developed QM/QM approach "QUILD". In line with previous studies, most standard density functionals recover, at best, only part of the favorable stacking interactions. An exception is the new KT1 functional, which correctly yields bound ?-stacked structures. Surprisingly, a similarly good performance is achieved with the computationally very robust and efficient local density approximation (LDA). Furthermore, we show that classical electrostatic interactions determine the shape and depth of the ?-? stacking potential energy surface. Figure Additivity approximation for the ?-? interaction between two stacked Watson–Crick base pairs in terms of pairwise interactions between individual bases Electronic supplementary material The online version of this article (doi:10.1007/s00894-007-0239-y) contains supplementary material, which is available to authorized users.

Swart, Marcel; van der Wijst, Tushar; Fonseca Guerra, Celia

2007-01-01

303

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

304

ADVANCED HYBRID PARTICULATE COLLECTOR  

SciTech Connect

A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be caused by electrical effects. Subsequently, extensive theoretical, bench-scale, and pilot-scale investigations were completed to find an approach to prevent bag damage without compromising AHPC performance. Results showed that the best bag protection and AHPC performance were achieved by using a perforated plate installed between the discharge electrodes and bags. This perforated-plate design was then installed in the 2.5-MW AHPC at Big Stone Power Plant in Big Stone City, South Dakota, and the AHPC was operated from March to June 2001. Results showed that the perforated-plate design solved the bag damage problem and offered even better AHPC performance than the previous design. All of the AHPC performance goals were met, including ultrahigh collection efficiency, high air-to-cloth ratio, reasonable pressure drop, and long bag-cleaning interval.

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

2001-12-01

305

Method and apparatus of periodically obtaining accurate opacity monitor readings of an exhaust gas stream  

SciTech Connect

This patent describes in an opacity monitor associated with an exhaust stack, the monitor having a transmitter and a receiving which cooperate to measure a quantity of particulate matter in an exhaust gas stream, a method of periodically obtaining opacity monitor readings. It comprises: shielding the monitor from the exhaust gas stream by placing two windows adjacent to the monitor, a first window being placed between the transmitter and the exhaust gas stream and a second window being placed between the receiver and the exhaust gas stream; cleaning at least one of the windows for a first predetermined time period by spraying a volatile nonflammable cleaning solvent onto the window by means of a sprayer intermittently operable during the first predetermined time period while wiping the window with a reciprocating wiper arm in resilient engagement therewith; then obtaining an opacity monitor reading by directing a light beam across the exhaust stack from the transmitter via the first window through the exhaust gas stream to the receiver via the second window; and alternately repeating the step of cleaning the window with the step of obtaining an opacity monitor reading.

Weaver, K.L.; Bellows, J.C.

1990-01-23

306

Wind induced vibration of a stack  

SciTech Connect

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

Chen, S.S.; Cai, Y.

1992-01-01

307

Wind induced vibration of a stack  

SciTech Connect

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

Chen, S.S.; Cai, Y.

1992-12-01

308

Fire extinguishing attachment for chimney stacks  

SciTech Connect

A fire extinguishing attachment including a bracket for mounting on a stove stack and having a tubular guide therethrough. The tubular guide is an elbow tube having an inner end within the stack directed towards the chimney flue and an outer end outside the stack adapted to receive the nozzle of a powder type fire extinguisher. When a chimney fire occurs, the extinguisher is placed over the outer end of the guide end and activated. The powdered material is directed, by the guide, into the stack and up the chimney to the location of the fire thereby extinguishing the fire. The guide and bracket is preferably downstream of the damper in the same section of stack to be close to the chimney, and for unobstructed flow.

Sawtelle, K.

1984-11-13

309

A study of air particulate pollution in colombo using a nuclear-related analytical technique  

Microsoft Academic Search

Air particulate matter of two size fractions (coarse [2.5–10 ?m] and fine [less than 2.5 ?m]) were collected at an urban residential\\u000a site (Colombo University ground) over a period of 12 mo during 1996 using a Gent PM10 stacked filter unit. Seventy-five sets\\u000a of samples collected during this period were analyzed for 10 elements: Al, Si, K, S, Ca, Ti,

M. C. S. Seneviratne; P. Mahawatte; R. K. S. Fernando; R. Hewamanna; C. Sumithrarachchi

1999-01-01

310

Electrically heated particulate filter restart strategy  

DOEpatents

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

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

2011-07-12

311

High Pressure Particulate Physics Facility.  

National Technical Information Service (NTIS)

This report documents the initial development of the High Pressure Particulate Physics (HP3) facility. The facility is anticipated to allow precision impact of two flat plates at a very high degree of precision with minimal misalignment when completed. A ...

L. C. Chhabildas W. L. Cooper W. R. Maines

2011-01-01

312

Barrier RF stacking at Fermilab  

SciTech Connect

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

Weiren Chou et al.

2003-06-04

313

Electrical diesel particulate filter (DPF) regeneration  

DOEpatents

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

Gonze, Eugene V; Ament, Frank

2013-12-31

314

Breath stacking in children with neuromuscular disorders.  

PubMed

Respiratory muscle weakness in neuromuscular disorders (NMD) can lead to shallow breathing and respiratory insufficiency over time. Children with NMD often cannot perform maneuvers to recruit lung volume. In adults, breath stacking with a mask and one-way valve can achieve significantly increased lung volumes. To evaluate involuntary breath stacking (IBS) in NMD, we studied 23 children of whom 15 were cognitively aware and able to communicate verbally. For IBS, a one-way valve and pneumotachograph were attached to a face mask. Tidal volumes (Vt) and minute ventilation (VE ) were calculated from airflow over 30?sec before and after 15?sec of expiratory valve closure. Six cooperative male subjects with Duchenne muscular dystrophy (DMD) participated in a subsequent comparison of IBS with voluntary breath stacking (VBS) and supported breath stacking (SBS). The average Vt in those studied with IBS was 277?ml (range 29-598?ml). The average increase in volume by stacking was 599?ml (range -140 to 2,916?ml) above Vt . The average number of stacked breaths was 4.5 (range 0-17). VE increased on average by 18% after stacking (P?stacking. Four of the 23 children did not breath stack. Compared to IBS, VBS achieved similar volumes in the six subjects with DMD but SBS was more successful in those with greatest muscle weakness. IBS may achieve breath volumes of approximately three times Vt and may be particularly useful in non-cooperative subjects with milder degrees of respiratory muscle weakness. Pediatr Pulmonol. 2014; 49:544-553. © 2013 Wiley Periodicals, Inc. PMID:23956183

Jenkins, H M; Stocki, A; Kriellaars, D; Pasterkamp, H

2014-06-01

315

In-situ infrared detection of stack gases  

NASA Astrophysics Data System (ADS)

Infrared measurement using gas-filter correlation (GFC) detection offers an accurate, sensitive, and highly selective technique for the quantitative detection of a number of common industrial gases. A radiative transfer model based on the HITRAN database has been developed to permit the response function of such an instrument to be calculated. The model has been applied to a number of gases, calculating the instrument response to both the target gas and selected interferent species over a broad range of stack temperatures. An optical probe GFC detector has been designed for in-stack measurements of CO and HCl from incinerators and thermal power stations. The probe can be purged with clean air for a true baseline check and a calibration chamber is provided which allows the instrument to be calibrated using bottled gas mixtures. The instrument has completed a successful plant trial during which it measured CO emissions from a coal-fired power station, showing a detection sensitivity of 5 ppm. Detection of HCl has also been demonstrated in the laboratory.

Stuart, Derek D.

1993-03-01

316

Slip stacking experiments at Fermilab main injector  

SciTech Connect

In order to achieve an increase in proton intensity, Fermilab Main Injector will use a stacking process called ''slip stacking''. The intensity will be doubled by injecting one train of bunches at a slightly lower energy, another at a slightly higher energy, then bringing them together for the final capture. Beam studies have started for this process and we have already verified that, at least for a low beam intensity, the stacking procedure works as expected. For high intensity operation, development work of the feedback and feedforward systems is under way.

Kiyomi Koba et al.

2003-06-02

317

Repetitively pulsed high power stacked Blumlein generators  

NASA Astrophysics Data System (ADS)

The stacked Blumlein pulse generators developed at the University of Texas at Dallas consist of several triaxial Blumleins stacked in series at one end. The lines are charged in parallel and synchronously commuted with a single switching element at the other end. In this way, relatively low charging voltages are multiplied to give the desired discharge voltage across an arbitrary load. Described here is the progress in development and characterization of these novel pulse-power generators capable of discharging at high repetition rates. The introduction of a tapered transmission line concept to the stacked Blumlein design provided fine tuning of output waveforms.

Davanloo, F.; Borovina, D. L.; Collins, C. B.; Agee, F. J.; Kingsley, L. E.

1995-05-01

318

Dry scrubbing: a new concept for removing odor and particulates from kraft recovery furnace stack gases  

Microsoft Academic Search

In order to meet regulatory standards, existing kraft mills, with direct contact evaporators, have essentially the following three options: installation of a new, larger recovery furnace to replace the existing overloaded furnace; or to build a second recovery furnace to handle the extra load; installation or upgrading of existing weak black and\\/or strong black liquor oxidation system(s); these systems are

Bhatia

1984-01-01

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

Hydrocarbon-enhanced particulate filter regeneration via microwave ignition  

DOEpatents

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

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

2010-02-02

321

Wearable solar cells by stacking textile electrodes.  

PubMed

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

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

2014-06-10

322

40 CFR 61.44 - Stack sampling.  

Code of Federal Regulations, 2010 CFR

...POLLUTANTS National Emission Standard for Beryllium Rocket Motor Firing § 61.44 Stack sampling. (a...days after samples are taken and before any subsequent rocket motor firing or propellant disposal at the given...

2010-07-01

323

40 CFR 61.44 - Stack sampling.  

Code of Federal Regulations, 2010 CFR

...POLLUTANTS National Emission Standard for Beryllium Rocket Motor Firing § 61.44 Stack sampling. (a...days after samples are taken and before any subsequent rocket motor firing or propellant disposal at the given...

2009-07-01

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

Evaluation Methodology Guidance for Stack Packages.  

National Technical Information Service (NTIS)

This report provides evaluation methodology guidance based on previous National Aeronautics and Space Administration (NASA) reports and literature surveys for 3D stack packages and assemblies. Two aspects of technology are covered: package itself (guidanc...

D. Gerke R. Ghaffarian

2009-01-01

326

On Understanding Stacking Fault Formation in Ice  

NASA Astrophysics Data System (ADS)

Despite dedicated efforts aimed at revealing possible molecular structures of the ice defects associated with stacking faults in ice (I), these molecular arrangements have remained a puzzle. Here we demonstrate how the reorganization of water molecules on different faces of ice (I) can facilitate formation of stacking faults within a crystal. We show that a pair of point defects can manifest a particular combination of coupled five- and eight-membered rings (5-8 rings). These structural motifs can facilitate a shift in layers within an ice (I) crystal, thereby inducing stacking faults. Furthermore, the presence of molecular solutes such as methane at the ice interface appears to trigger the formation of coupled 5-8 rings. The observation of such coupled 5-8 ring defects provides insights into the possible molecular mechanisms of stacking fault formation in ice (I) and has implications for ice crystal growth phenomenology and the consequent physical and chemical properties of ice.

Pirzadeh, Payman; Kusalik, Peter G.

2012-12-01

327

Development of Mechanically Stacked Tandem Concentrator Cells.  

National Technical Information Service (NTIS)

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 followi...

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

1987-01-01

328

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

329

PAH emission from various industrial stacks  

Microsoft Academic Search

The emission of polycyclic aromatic hydrocarbons (PAHs) from various industrial stacks (blast furnace, basic oxygen furnace, coke oven, electric arc furnace, heavy oil plant, power plant and cement plant) in southern Taiwan were investigated. PAH concentrations (?g\\/N m3) and PAH emission factors (?g\\/kg feedstock) were determined. In addition to these eight stationary industrial stacks, an industrial waste incinerator, a diesel

Hsi-Hsien Yang; Wen-Jhy Lee; Shui-Jen Chen; Soon-Onn Lai

1998-01-01

330

Cosmic ray test of INO RPC stack  

NASA Astrophysics Data System (ADS)

The India-based Neutrino Observatory (INO) collaboration is planning to build a 50 kt magnetised iron calorimeter (ICAL) detector using glass Resistive Plate Chambers (RPCs) as active detector elements. A stack of 12 such glass RPCs of 1 m ×1 m in area is tracking cosmic ray muons for over three years. In this paper, we will review the constructional aspects of the stack and discuss the performance of the RPCs using this cosmic ray data.

Bhuyan, M.; Datar, V. M.; Kalmani, S. D.; Lahamge, S. M.; Mondal, N. K.; Nagaraj, P.; Pal, S.; Reddy, L. V.; Redij, A.; Samuel, D.; Saraf, M. N.; Satyanarayana, B.; Shinde, R. R.; Verma, P.

2012-01-01

331

Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System  

SciTech Connect

Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle dispersion. The results of these simulations suggest the air blender should be included in the stack system to ensure qualification of the stack.

Recknagle, Kurtis P.; Barnett, J. M.; Suffield, Sarah R.

2013-01-23

332

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

333

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

SciTech Connect

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

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

2009-02-15

334

Radiative Heat Transfer in Combustion Applications: Parallel Efficiencies of Two Gas Models, Turbulent Radiation Interactions in Particulate Laden Flows, and Coarse Mesh Finite Difference Acceleration for Improved Temporal Accuracy  

NASA Astrophysics Data System (ADS)

We investigate several aspects of the numerical solution of the radiative transfer equation in the context of coal combustion: the parallel efficiency of two commonly-used opacity models, the sensitivity of turbulent radiation interaction (TRI) effects to the presence of coal particulate, and an improvement of the order of temporal convergence using the coarse mesh finite difference (CMFD) method. There are four opacity models commonly employed to evaluate the radiative transfer equation in combustion applications; line-by-line (LBL), multigroup, band, and global. Most of these models have been rigorously evaluated for serial computations of a spectrum of problem types [1]. Studies of these models for parallel computations [2] are limited. We assessed the performance of the Spectral-Line-Based weighted sum of gray gasses (SLW) model, a global method related to K-distribution methods [1], and the LBL model. The LBL model directly interpolates opacity information from large data tables. The LBL model outperforms the SLW model in almost all cases, as suggested by Wang et al. [3]. The SLW model, however, shows superior parallel scaling performance and a decreased sensitivity to load imbalancing, suggesting that for some problems, global methods such as the SLW model, could outperform the LBL model. Turbulent radiation interaction (TRI) effects are associated with the differences in the time scales of the fluid dynamic equations and the radiative transfer equations. Solving on the fluid dynamic time step size produces large changes in the radiation field over the time step. We have modified the statistically homogeneous, non-premixed flame problem of Deshmukh et al. [4] to include coal-type particulate. The addition of low mass loadings of particulate minimally impacts the TRI effects. Observed differences in the TRI effects from variations in the packing fractions and Stokes numbers are difficult to analyze because of the significant effect of variations in problem initialization. The TRI effects are very sensitive to the initialization of the turbulence in the system. The TRI parameters are somewhat sensitive to the treatment of particulate temperature and the particulate optical thickness, and this effect are amplified by increased particulate loading. Monte Carlo radiative heat transfer simulations of time-dependent combustion processes generally involve an explicit evaluation of emission source because of the expense of the transport solver. Recently, Park et al. [5] have applied quasi-diffusion with Monte Carlo in high energy density radiative transfer applications. We employ a Crank-Nicholson temporal integration scheme in conjunction with the coarse mesh finite difference (CMFD) method, in an effort to improve the temporal accuracy of the Monte Carlo solver. Our results show that this CMFD-CN method is an improvement over Monte Carlo with CMFD time-differenced via Backward Euler, and Implicit Monte Carlo [6] (IMC). The increase in accuracy involves very little increase in computational cost, and the figure of merit for the CMFD-CN scheme is greater than IMC.

Cleveland, Mathew A.

335

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

336

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

337

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

338

Elemental composition of arctic particulate matter  

NASA Technical Reports Server (NTRS)

Measurements were made of the elemental composition of particulate matter collected in flights in the Arctic in spring 1983 as part of the Arctic Gas and Aerosol Sampling Program (AGASP). Ten samples of size-selected particles were analyzed by four nondestructive techniques at Davis. Concentrations were determined for H, C, N, and O by Forward Alpha Scattering Techniques (FAST) and for elements heavier than fluorine by Particle Induced X-ray Emission (PIXE). Total mass was measured gravimetrically, and optical absorption was measured using the Laser Integrating Plate Method (LIPM). Results of the analyses show dramatic differences in concentrations and elemental ratios from the Alaskan Arctic to the Norwegian Arctic, with indications of wood smoke and sulfuric acid in the arctic atmosphere.

Cahill, T. A.; Eldred, R. A.

1984-01-01

339

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

340

Stacking sequence optimizations using GA with zoomed response surface on lamination parameters  

Microsoft Academic Search

Stacking sequence optimizations for composite laminates are combinatorial optimization problems often handled by genetic algorithms (GA). Unfortunately, GAs often require large com- putational resources for individual evaluation. To overcome this problem, this paper proposes use of lamination parameters in an optimization process approach with GA. The optimization process requires precise approximation of design space using response surfaces to obtain the

MASAFUMI SASAI

2003-01-01

341

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...

342

Simultaneous Treatment of SO2 Containing Stack Gases and Waste Water.  

National Technical Information Service (NTIS)

A process is described for simultaneously removing sulfur dioxide from stack gases and the like, and for purifying waste water such as derived from domestic sewage. A portion of the gas stream and a portion of the waste water, the latter containing dissol...

J. C. Poradek D. D. Collins

1978-01-01

343

Adsorption and photodegradation of pyrene on magnetic, carbonaceous, and mineral subfractions of coal stack ash  

Microsoft Academic Search

Two coal stack ashes have been separated into three principal subfractions (carbonaceous, mineral, and magnetic). Photoreactivities and adsorptivities of pyrene on the three subfractions have been determined, the latter by gas-solid chromatography. For each ash, the carbonaceous subfraction is the strongest adsorbent and has the greatest ability to stabilize adsorbed pyrene toward photodegradation, while the mineral subfraction is a much

T. D. J. Dunstan; Robert F. Mauldin; Zhong Jinxian; Anthony D. Hipps; E. L. Wehry; Gleb Mamantov

1989-01-01

344

Manifold gasket accommodating differential movement of fuel cell stack  

DOEpatents

A gasket for use in a fuel cell system having at least one externally manifolded fuel cell stack, for sealing the manifold edge and the stack face. In accordance with the present invention, the gasket accommodates differential movement between the stack and manifold by promoting slippage at interfaces between the gasket and the dielectric and between the gasket and the stack face.

Kelley, Dana A. (New Milford, CT); Farooque, Mohammad (Danbury, CT)

2007-11-13

345

High efficiency particulate removal with sintered metal filters  

NASA Astrophysics Data System (ADS)

Because of their particle removal efficiencies and durability, sintered metal filters have been chosen for high efficiency particulate air (HEPA) filter protection in the off gas treatment system for a proposed transuranic waste treatment facility. Process evaluation of sintered metal filters indicated a lack of sufficient process design data to ensure trouble free operation. Subsequence pilot scale testing was performed with flyash as the test particulate. The test results showed that the sintered metal filters can have an efficiency greater than 0.9999999 for the specific test conditions used. Stable pressure drop characteristics were observed in pulsed and reversed flow blowback modes of operation. Over 4900 hours of operation were obtained with operating conditions ranging up to approximately 90 C and 24 vol % water vapor in the gas stream.

Kirstein, B. E.; Paplawsky, W. J.; Pence, D. T.; Hedahl, T. G.

346

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...

347

Contribution of SO2 sorption on particulate surface to the air pollution level in the vicinity of coal-fired power plants.  

PubMed

The area under study is influenced by three lignite-fired power plants. The distribution of SO2 concentrations in the air over the area has been calculated. The calculations include SO2 sorption on the surface area of the emitted particulates--stack dust and fly ash. The surface sorption process has been investigated on a laboratory scale. PMID:2781265

Matyniak, Z

1989-07-01

348

Atmospheric Particulate Measurements in Norfolk, Virginia.  

National Technical Information Service (NTIS)

Characterization of atmospheric particulates was conducted at a site near the center of Norfolk, Virginia. Air quality was measured in terms of atmospheric mass loading, particle size distribution, and particulate elemental composition for a period of 2 w...

R. W. Storey R. J. Sentell D. C. Woods J. R. Smith F. S. Harris

1975-01-01

349

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 ...

350

PARTICULATE EMISSION MEASUREMENTS FROM CONTROLLED CONSTRUCTION ACTIVITIES  

EPA Science Inventory

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

351

Method for dispersing catalyst onto particulate material.  

National Technical Information Service (NTIS)

A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal s...

B. R. Utz A. V. Cugini

1990-01-01

352

PAVED ROAD PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT  

EPA Science Inventory

The report gives results of extensive field tests to develop emission factors for particulate emissions generated by traffic entrainment of paved road surface particulate matter. Using roadway surface silt loading as the basis, predictive emission factor equations for each partic...

353

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

354

A novel optical scattering collection system for particulate monitoring applications  

SciTech Connect

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

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

1996-05-01

355

HIGH GRADIENT MAGNETIC PARTICULATE COLLECTION  

EPA Science Inventory

This paper describes the initial phases of an evaluation of high gradient magnetic separation (HGMS) as a potential method of fine particle collection from industrial stack gases. HGMS is a relatively new separation technique that has been shown to be capable of removing small, w...

356

Process for particulate removal from coal liquids  

DOEpatents

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

Rappe, Gerald C. (Macungie, PA)

1983-01-01

357

MTR STACK, TRA710, CONTEXTUAL VIEW AFTER ETR STACK HAD BEEN ...  

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

MTR STACK, TRA-710, CONTEXTUAL VIEW AFTER ETR STACK HAD BEEN DEMOLISHED. CAMERA FACING NORTHWEST. MTR BUILDING IS AT LEFT EDGE OF VIEW. INL NEGATIVE NO. HD52-1-4. Mike Crane, Photographer, 5/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

358

Smart stackingTM technology: An industrial solution for 3D layer stacking  

Microsoft Academic Search

Smart Stacking™ is a wafer-to-wafer stacking technology of partially or fully processed wafers. This technology enables transferring very thin layers in a high volume manufacturing environment. The core technologies are surface conditioning, low temperature direct bonding and wafer thinning (figure 1). This technology is adapted for advanced semiconductor applications such as Back Side Illumination (BSI) CMOS Image Sensors (CIS) as

C. Lagahe Blanchard; I. Radu; M. Sadaka; K. Landry

2011-01-01

359

Solid particulate aerosol fire suppressants  

Microsoft Academic Search

A variety of private and public sector programs are developing a new class of fire suppressants, known generically as solid particulate aerosols. These have superior volumetric efficiency, low initial and life-cycle costs, low toxicity, no known global atmospheric environmental impacts (ODP\\/GWP), and the potential for a wide variety of applications. Researchers are developing solid compound formulations that, when pyrotechnically initiated,

Charles J. Kibert; Douglas Dierdorf

1994-01-01

360

MODELING PARTICULATE CHARGING IN ESPS  

EPA Science Inventory

In electrostatic precipitators there is a strong interaction between the particulate space charge and the operating voltage and current of an electrical section. Calculating either the space charge or the operating point when the other is fixed is not difficult, but calculating b...

361

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

362

MONITORING OF PARTICULATE MATTER OUTDOORS  

EPA Science Inventory

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 b...

363

Ecological effects of particulate matter  

Microsoft Academic Search

Atmospheric particulate matter (PM) is a heterogeneous material. Though regulated as un-speciated mass, it exerts most effects on vegetation and ecosystems by virtue of the mass loading of its chemical constituents. As this varies temporally and spatially, prediction of regional impacts remains difficult. Deposition of PM to vegetated surfaces depends on the size distribution of the particles and, to a

D. A Grantz; J. H. B Garner; D. W Johnson

2003-01-01

364

Foam and particulate material with steam for permeability alteration in subsurface formations  

SciTech Connect

A method is disclosed for altering the permeability of a gravity override path through a subsurface earth formation resulting from hot fluid (steam) injection into the subsurface formation. The method includes adding sellected sized particulate material to a foam and injecting the foam into the gravity override path to deposit the particulate material thus altering the permeability in the path. The method may include the use of a noncondensible gas in the foam as well as a variety of combinations of the hot fluid injection and foam plus particulate material injection to maximize the sweep efficiency of the hot fluid injection into the subsurface formation.

Hutchison, S.O.

1984-09-11

365

Retrieval of aerosol size distribution moments from multiwavelength particulate extinction measurements  

NASA Technical Reports Server (NTRS)

Two methods for inferring aerosol size distribution moments from multiwavelength particulate extinction measurements are studied. The methods are an eigenvalue technique that approximates an appropriate moment-weighting function by a linear combination of kernel functions and a conversion ratio approach that uses the ratio of the particulate extinction measurements at two wavelengths to choose a model moment-to-extinction conversion ratio. The techniques are applied to infer the third moment, or volume, of the aerosol size distribution from actual particulate extinction measurements taken as part of the Stratospheric Aerosol and Gas Experiment II during a correlative measurement experiment in Brazil in April 1985.

Livingston, John M.; Russell, Philip B.

1989-01-01

366

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

PubMed Central

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

2014-01-01

367

Technical description of Stack 296-B-5  

SciTech Connect

Of particular concern to facilities on the Hanford site is Title 40, Code of Federal Regulations, Chapter 40, Part 61, Subpart H, ``National emission Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities.`` Assessments of facility stacks and potential radionuclide emissions determined whether these stacks would be subject to the sampling and monitoring requirements of 40 CFR 61, Subpart H. Stack 296-B-5 exhausts 221-BB building which houses tanks containing B Plant steam condensate and B Plant process condensate from the operation of the low-level waste concentrator. The assessment of potential radionuclide emissions from the 296-B-5 stack resulted in an effective dose equivalent to the maximally exposed individual of less than 0.1 millirem per year. Therefore, the stack is not subject to the sampling and monitoring requirements of 40 CFR 61, Subpart H. However, the sampling and monitoring system must be in compliance with the Environmental Compliance Manual, WHC-CM-7-5. Currently, 296-B-5 is sampled continuously with a record sampler and continuous air monitor (CAM).

Ridge, T.M.

1994-11-15

368

Structure of Steady Particulate Seeded Plasma Flows Heated by a High Power Laser  

NASA Astrophysics Data System (ADS)

There is interest in efficient conversion of high power laser radiation into kinetic energy of a gas flow for some applications. Inverse Bremsstrahlung (IB) offers the advantage of spectral continuum absorption along with the rapid conversion of the absorbed energy into translational modes. However, IB is effective only when sufficient ionization is present. Hence, some mechanism must be operative at low temperatures to create and multiply an initial electron concentration. Seeding a gas flow with particulates is one such approach. Particulates absorb laser radiation and then thermally conduct heat to the surrounding gas. The effect of particulate seeding on the steady structure of ionized gas flows driven by a high power laser is investigated.

Mota, S.; Resendes, D. P.; Mendonça, J. T.

2005-10-01

369

Inflatable containment diaphragm for sealing and removing stacks  

DOEpatents

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

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

1993-01-01

370

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

371

Characteristics of particulates emitted from a biomass fluidized-bed gasifier  

SciTech Connect

This paper presents the particulate emission data for feeding cotton-gin trash and cattle feedlot manure into a 0.3048 m fluidized-bed gasifier. This data can then be used to design the necessary cleaning apparatus depending on the type of end use for the low-energy gas. The particulate emissions vary from 172 g/m/sup 3/ for cotton-gin trash fly ash to 456 g/m/sup 3/ for cattle feedlot manure.

Datin, D.L.; Lepori, W.A.; Parnell, C.B.

1983-12-01

372

Removal of SOx, NOx, and particulate from combusted carbonaceous fuels  

SciTech Connect

The invention is a method for removing sulfur oxides, nitrogen oxides and particulate from the products of combusted carbonaceous fuels. Sulfur oxides, nitrogen oxides and particulate are currently discharged to the atmosphere as flue gas in quantities highly detrimental to the environment. Potassium compounds, as are found in agricultural grade potash, are dispersed throughout the combustion products at the exit of the combustion zone of boilers. The potassium compounds decompose as a result of combustion temperatures in excess of their melting points. The potassium, as an ionic vapor, reacts with the sulfur and nitrogen oxide gases present, to form potassium sulfates, potassium nitrites and potassium nitrates. When the combined products stream, traversing the boiler equipment train, cool sufficiently, the potassium, present in excess, condenses as potassium oxide on the surfaces of the particles present. The larger particles are removed from the non-condensed vapor and gas by the centrifugal and gravitational forces exerted within cyclones. The smaller particles are removed from the non-chargable vapor and gases by the electrostatic charge and attraction created within the precipitator. The dry particles discharged from the cyclones and precipitator are ready for ultimate end use as potash fertilizer without further treatment. The flue gas atmospheric emissions contain only trace quantities of sulfur oxides, nitrogen oxides and particulate.

Dayen, W.R.

1985-09-10

373

Charge-to-mass ratio and dendrite structure of diesel particulate matter charged by corona discharge  

Microsoft Academic Search

The electric charge of diesel particulate matter (DPM) from a corona discharge device is measured for understanding the electrical characteristics of the DPM; an electrostatic precipitator (ESP) is employed for trapping DPM. Exhaust gas from a diesel engine is sampled by isokinetic sampling, and DPM contained in the gas is charged by negative corona discharge. The charged DPM is collected

Tomoyuki Kuroki; Motoki Ishidate; Masaaki Okubo; Toshiaki Yamamoto

2010-01-01

374

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

375

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

NASA Astrophysics Data System (ADS)

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

Kooten, R. Van

2014-01-01

376

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

377

76 FR 28646 - Implementation of the New Source Review (NSR) Program for Particulate Matter Less Than 2.5...  

Federal Register 2010, 2011, 2012, 2013

...administered by EPA in states that lack a PSD...their approved state implementation...controlling particulate matter less than 10 micrometers (PM 10 ) and analyzing impacts...EPA-approved state PSD programs...32551. Natural gas...

2011-05-18

378

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

SciTech Connect

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

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

1991-08-01

379

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

SciTech Connect

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

Not Available

1990-05-01

380

Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature  

DOEpatents

A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

Eckels, David E. (Ankeny, IA); Hass, William J. (Ames, IA)

1989-05-30

381

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

382

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

383

Primary lithium-chlorine cells - Investigations toward a pelletized stack design  

NASA Astrophysics Data System (ADS)

The course of development presently chosen for primary lithium-chlorine cells has been aimed toward a flat pellet/stack-type configuration typical of conventional reserve-type thermal batteries. The chlorine feed is to dead-ended, porous graphite supporting electrodes, effected by flooding chlorine gas to the exterior of the battery stack. Pure LiCl would be the ideal electrolyte for conductivity maximization, but due to its over-600 C melting point and increased problems with corrosion, lower melting point salts were selected for these investigations. Li alloy anodes were chosen in order to avoid the containment problems associated with liquid Li.

Lamb, C. M.; Hurst, J. T.

384

Cation-induced pi-stacking.  

PubMed

The design and synthesis of a new dipyridyl ligand with appended phenanthryl moieties is described. On addition of increments of silver(I) trifluoromethanesulfonate to a solution of the ligand, the phenanthryl protons shift upfield in the (1)H NMR spectrum, suggesting that the phenanthrenes pi-stack on coordination of silver(I). In accord with this, the oxidation potential decreased from 1.74 to 1.55 V on complexation of silver(I). The pi-stacking was confirmed with the single-crystal X-ray structure of a palladium(II) coordination complex. PMID:18407690

Bosch, Eric; Barnes, Charles L; Brennan, Nathan L; Eakins, Galen L; Breyfogle, Bryan E

2008-05-16

385

Coherent emission of light using stacked gratings  

NASA Astrophysics Data System (ADS)

The possibility of temporally and spatially coherent thermal emission has been demonstrated utilizing stacked gratings. We demonstrate that the metallic grating with narrow air slit behaves like a homogeneous slab with large permittivity and small permeability and find that the interaction between the metallic grating and the Bragg grating gives rise to impendence matching at wavelengths located in the photonic band gap of the Bragg grating, which enables the stacked gratings to perform high emission with ultranarrow spectrum and antenna-like spatial response. This paves the way towards the design of a novel infrared source platform for applications such as thermal analysis, imaging, security, biosensing, and medical diagnoses.

Gong, Yongkang; Liu, Xianliang; Li, Kang; Huang, Jungang; Martinez, J. J.; Rees-Whippey, Daniel; Carver, Sara; Wang, Leiran; Zhang, Wenfu; Duan, Tao; Copner, Nigel

2013-05-01

386

Low exhaust temperature electrically heated particulate matter filter system  

DOEpatents

A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.

Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI); Bhatia, Garima (Bangalore, IN)

2012-02-14

387

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

NASA Astrophysics Data System (ADS)

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

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

1981-03-01

388

Polarization signatures of airborne particulates  

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

389

Flue gas desulfurization  

Microsoft Academic Search

The invention involves a combustion process in which combustion gas containing sulfur oxide is directed past a series of heat exchangers to a stack and in which a sodium compound is added to the combustion gas in a temparature zone of above about 1400 K to form NaâSOâ. Preferably, the temperature is above about 1800 K and the sodium compound

K. H. Im; R. K. Ahluwalia

1984-01-01

390

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

391

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

392

SRS reactor stack plume marking tests  

SciTech Connect

Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart.

Petry, S.F.

1992-03-01

393

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

394

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

395

Fiber Tracking: A Recursive Stack Algorithmic Approach  

Microsoft Academic Search

In diffusion tensor magnetic resonance imaging (DT-MRI), each voxel is assigned a tensor that describes local water diffusion. In this study, the eigenvectors and eigenvalues of the diffusion tensor D are analyzed based on stack linked list algorithm. The aim of the study is to develop a reliable and rapid tractography algorithm. In our sample, 60 diffusion weighted human brain

Dilek Göksel Duru; Mehmed Özkan

2007-01-01

396

49 CFR 178.815 - Stacking test.  

Code of Federal Regulations, 2013 CFR

...capacity and to its maximum net mass, with the load being evenly...their maximum permissible gross mass and stacked on the test IBC...combined maximum permissible gross mass of the number of similar IBCs...container in pounds. s = specific gravity (liquids) or density...

2013-10-01

397

49 CFR 178.980 - Stacking test.  

Code of Federal Regulations, 2013 CFR

...capacity and to their maximum net mass, with the load being evenly...their maximum permissible gross mass and stacked on the test Large...combined maximum permissible gross mass of the number of similar Large...container in pounds. s = specific gravity (liquids) or density...

2013-10-01

398

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.

399

Parachute Having Improved Vent Line Stacking.  

National Technical Information Service (NTIS)

A parachute having an improved vent line stacking wherein the parachute is provided with a canopy having a central vent opening and a vent band secured to the canopy around the periphery of the vent opening, with a plurality of vent lines each lying on a ...

J. E. Hengel

1993-01-01

400

Trace interpolation by slant-stack migration  

SciTech Connect

The slant-stack migration formula based on the radon transform is studied with respect to the depth steep {Delta}z of wavefield extrapolation. It can be viewed as a generalized trace-interpolation procedure including wave extrapolation with an arbitrary step {Delta}z. For {Delta}z {gt} 0 the formula yields the familiar plane-wave decomposition, while for {Delta}z {gt} 0 it provides a robust tool for migration transformation of spatially under sampled wavefields. Using the stationary phase method, it is shown that the slant-stack migration formula degenerates into the Rayleigh-Sommerfeld integral in the far-field approximation. Consequently, even a narrow slant-stack gather applied before the diffraction stack can significantly improve the representation of noisy data in the wavefield extrapolation process. The theory is applied to synthetic and field data to perform trace interpolation and dip reject filtration. The data examples presented prove that the radon interpolator works well in the dip range, including waves with mutual stepouts smaller than half the dominant period.

Novotny, M. (Geofyzika, n.p., Brno (Czechoslovakia))

1990-11-01

401

A survey of dynamically adaptable protocol stacks  

Microsoft Academic Search

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

Vangelis Gazis; Eleni Patouni; Nancy Alonistioti; Lazaros Merakos

2010-01-01

402

Wind induced vibration of a stack.  

National Technical Information Service (NTIS)

A stack supported by guy wires at four levels is subjected to large-amplitude oscillations when the wind speed is over 15 m/s. The excitation mechanisms are identified based on scoping calculations, analytical prediction using a finite element code, and o...

S. S. Chen Y. Cai

1992-01-01

403

Explosive demolition of K East Reactor Stack  

SciTech Connect

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

2010-07-26

404

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

405

Wind-tunnel study of atmospheric dispersion of exhausts from the stack of building 222  

SciTech Connect

The dispersion of trace amounts of gases and particles from the stack of Building 222 at Lawrence Livermore National Laboratory was investigated by conducting scaled experiments in an atmospheric wind tunnel. The stack is 28m tall and is located in a suburban-type setting surrounded by two- and three-story buildings and medium- height trees. The wind-tunnel boundary layer was representative of a slightly unstable atmosphere with velocity and turbulence intensity profiles comparable to those in full scale at the Laboratory. Wind-tunnel tests consisted of releasing an ethane tracer gas from the stack in the tunnel and measuring horizontal and vertical concentration profiles as well as ground-level concentration profiles to distances of 600m from the stack. Tests were conducted for conditions representative of wind speeds of 6 mph and 11 mph at the stack height and for nine different wind directions. Smoke tracer tests were conducted to show air-flow streamlines, and wake effects and recirculation zones caused by nearby tree and building obstructions. Results of the smoke tests show that recirculation zones do not envelope the top of the stack. However, they also show that the wake of nearby trees or a wake caused by the upwind edge of the building does extend to heights above the stack. Results of the ground-level concentration measurements show values that agree favorably with those predicted by Gaussian dispersion models. The wind-tunnel results also were favorably compared to a full-scale case for which ground-level concentration data were available. 9 refs., 50 figs., 2 tabs.

Stein, W.; White, B.R.; Kavanagh, J.; Brucker, D.; Castro, E.; Bagheri, N.; Strataridakis, C.J.

1989-01-01

406

SOUTHERN FINE PARTICULATE MONITORING PROJECT  

SciTech Connect

This is the second quarterly progress report of the ''Southern Fine Particulate Monitoring Project'', funded by the U.S. Department of Energy's National Energy Technology Laboratory under DOE Cooperative Agreement No. DE-FC26-00NT40770 to Southern Research Institute (SRI). In this two year project SRI will conduct detailed studies of ambient fine particulate matter in the Birmingham, AL metropolitan area. Project objectives include: Augment existing measurements of primary and secondary aerosols at an established urban southeastern monitoring site; Make a detailed database of near-continuous measurements of the time variation of fine particulate mass, composition, and key properties (including particle size distribution); Apply the measurements to source attribution, time/transport properties of fine PM, and implications for management strategies for PM{sub 2.5}; and Validate and compare key measurement methods used in this study for applicability within other PM{sub 2.5} research by DOE-FE, EPA, NARSTO, and others.

Ashley D. Williamson

2001-04-01

407

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

PubMed

Broken symmetry of vortices due to induced-charge electro-osmosis (ICEO) around stacking structures is important for the generation of a large net flow in a microchannel. Following theoretical predictions in our previous study, we herein report experimental observations of asymmetrical reverse vortex flows around stacking structures of carbon posts with a large height (~110 ?m) in water, prepared by the pyrolysis of a photoresist film in a reducing gas. Further, by the use of a coupled calculation method that considers boundary effects precisely, the experimental results, except for the problem of anomalous flow reversal, are successfully explained. That is, unlike previous predictions, the precise calculations here show that stacking structures accelerate a reverse flow rather than suppressing it for a microfluidic channel because of the deformation of electric fields near the stacking portions; these structures can also generate a large net flow theoretically in the direction opposite that of a previous prediction for a standard vortex flow. Furthermore, by solving the one-dimensional Poisson-Nernst-Plank (PNP) equations in the presence of ac electric fields, we find that the anomalous flow reversal occurs by the phase retardation between the induced diffuse charge and the tangential electric field. In addition, we successfully explain the nonlinearity of the flow velocity on the applied voltage by the PNP analysis. In the future, we expect to improve the pumping performance significantly by using stacking structures of conductive posts along with a low-cost process. PMID:21728661

Sugioka, Hideyuki

2011-05-01

408

Antiproton stacking and un-stacking in the Fermilab Recycler Ring  

SciTech Connect

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

Chandra Bhat

2003-06-12

409

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

410

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

411

Gaseous and particulate emissions from a DC arc melter.  

PubMed

Tests treating soils contaminated with metal compounds and radionuclide surrogates were conducted in a DC arc melter. The soil melted, and glassy or ceramic waste forms with a separate metal phase were produced. Tests were run in the melter plenum with either air or N2 purge gases. In addition to nitrogen, the primary emissions of gases were CO2, CO, oxygen, methane, and oxides of nitrogen (NO(x)). Although the gas flow through the melter was low, the particulate concentrations ranged from 32 to 145 g/m3. Cerium, a nonradioactive surrogate for plutonium and uranium, was not enriched in the particulate matter (PM). The PM was enriched in cesium and highly enriched in lead. PMID:12568249

Overcamp, Thomas J; Speer, Matthew P; Griner, Stewart J; Cash, Douglas M

2003-01-01

412

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

413

29 CFR 1917.14 - Stacking of cargo and pallets.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Stacking of cargo and pallets. 1917.14 Section 1917.14 Labor Regulations...Operations § 1917.14 Stacking of cargo and pallets. Cargo, pallets and other material stored in tiers shall be...

2009-07-01

414

29 CFR 1917.14 - Stacking of cargo and pallets.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Stacking of cargo and pallets. 1917.14 Section 1917.14 Labor Regulations...Operations § 1917.14 Stacking of cargo and pallets. Cargo, pallets and other material stored in tiers shall be...

2010-07-01

415

IET. Exhaust stack foundation under construction. Reinforced concrete footings for ...  

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

IET. Exhaust stack foundation under construction. Reinforced concrete footings for duct at right of stack. Foundation is in octagonal shape. Date: October 29, 1954. INEEL negative no. 12711 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

416

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

417

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

SciTech Connect

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

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

2009-05-01

418

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

419

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

SciTech Connect

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

James E. O'Brien; Joseph J. Hartvigsen

2007-06-01

420

Induct flue gas conditioning system  

Microsoft Academic Search

In a system for conditioning flue gas generated by a boiler furnace prior to its emission to the atmosphere, including conduit means for conducting a flow of flue gas from said boiler furnace to the atmosphere and an electrostatic precipitator located in said conduit means for electrostatically removing particulate matter entrained in the flue gas, the improvement is described comprising:

1993-01-01

421

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.

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

422

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

423

Enlèvement de particules par laser impulsionnel  

NASA Astrophysics Data System (ADS)

L'enlèvement de particules par laser impulsionnel (ns) est étudié expérimentalement. Des efficacités supérieures à 90% sont obtenues pour l'enlèvement de particules de polystyrene (PS) de diamètre 385 nm sur des surfaces de Si et Cu. Les fluences seuils d'enlèvement sont déterminées et comparées à une modélisation de l'expansion thermique du substrat. L'interprétation est discutée en terme de mécanismes fondamentaux envisageables responsables de l'éjection des particules.

Grojo, D.; Delaporte, P.; Cros, A.

2005-06-01

424

Zone heated diesel particulate filter electrical connection  

DOEpatents

An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI)

2010-03-30

425

Diesel particulate filter with zoned resistive heater  

DOEpatents

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

426

DEVELOPMENT OF COMPUTER MODULES OF PARTICULATE PROCESSES FOR REGIONAL PARTICULATE MODEL  

EPA Science Inventory

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

427

Particulate Air Pollution and Morbidity in the California Central Valley: A High Particulate Pollution Region.  

National Technical Information Service (NTIS)

The purpose of this study was to evaluate the relationship between particulate air pollution and morbidity among the Kaiser Permanente (KP) membership who reside in the Central Valley (CV) of California. Daily augmented particulate matter (PM) monitoring ...

S. K. Van Den Eeden C. P. Quesenberry J. Shan F. Lurmann

2002-01-01

428

Characterization of airborne particulates in Bangkok urban area by neutron activation analysis.  

PubMed

Samples of airborne particulates were collected in a residential area and in an area near a busy highway in Bangkok during the period from January 1997 to May 1998. A stacked filter system was used for the former site and a Partisol 2000 was used for the latter site. Both 2.5 microns and 10-micron particulates were collected every week. The total suspended particulate matters were also collected at the latter site. The samples were analyzed by neutron activation analysis utilizing neutron flux from a 2-MW TRIGA MARK III research reactor. The elements most frequently detected in the airborne particulates were Al, As, Br, Ca, Ce, Cl, Co, Cr, Cs, Fe, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Th, Ti, V, and Zn. The enrichment factor and factor analysis were used to investigate trends, sources, and origin of the atmospheric aerosols. Anthropogenic elements in road dust, construction dust, motor vehicles emission, and other combustion components were identified. A comparative study of data between both sites was performed and it was found that the mass concentration in the area close to the highway was about three times higher than in the residential area. PMID:10676491

Nouchpramool, S; Sumitra, T; Leenanuphunt, V

1999-01-01

429

40 CFR 52.1169 - Stack height review.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height review. 52.1169 Section 52.1169... Massachusetts § 52.1169 Stack height review. The Commonwealth of Massachusetts...limitations have been affected by stack height credits greater than good...

2013-07-01

430

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

431

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

432

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

433

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

434

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

435

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

436

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

437

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

438

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

439

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

440

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

441

40 CFR 51.118 - Stack height provisions.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stack height provisions. 51.118 Section 51... Control Strategy § 51.118 Stack height provisions. (a) The plan must...affected by so much of any source's stack height that exceeds good engineering...

2013-07-01

442

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

443

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

444

Overhead-Free Heterogeneous Thread-Stack Checkpointing  

Microsoft Academic Search

Checkpointing is the process of taking a snapshot of a thread's stack and possibly the objects that it uses such that a thread can be either restarted (for error recovery) or moved to another machine ( to im- prove load balancing). Current approaches to thread stack checkpointing are eithe r not heterogeneous as they do not allow a call stack

Ronald Veldema; Michael Philippsen

445

Take It From The Top: How Does This Stack Up?  

NSDL National Science Digital Library

In this activity, learners explore center of gravity, or balance point, of stacked blocks. Simple wooden blocks can be stacked so that the top block extends completely past the end of the bottom block, seemingly in a dramatic defiance of gravity. A mathematical pattern can be noted in the stacking.

Exploratorium, The

2012-06-26

446

A unified approach to implementation of stack filters  

Microsoft Academic Search

New stack filter architectures are proposed. Known architectures are considered from new positions and combined to obtain new structures with suitable complexities and throughputs. It is shown that all stack filters can be used without changes when the input data is represented in one of the binary lexicographic codes. Stack filters are also proposed for the cases where the data

J. Astola; D. Akopian; S. Agaian; O. Vainio

1994-01-01

447

Adjustable cutting guide aligns and positions stacks of material  

NASA Technical Reports Server (NTRS)

Adjustable guide tool aligns and positions stacks of material for cutting at various angles. The device adapts its shape to stacks of any corner angle, adjusts to any cutting angle, and quickly aligns the stacks for repeated cutting. With this device, an operator need not place his hands under the knife during alignment.

Thiel, A. M.

1966-01-01

448

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

449

Annular feed air breathing fuel cell stack  

DOEpatents

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

Wilson, Mahlon S. (Los Alamos, NM)

1996-01-01

450

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

451

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

452

Stacking interactions between adenines in oxidized oligonucleotides.  

PubMed

The effects of stacking interactions on the oxidation potentials of single strand oligonucleotides containing up to four consecutive adenines, alternated with thymines and cytosines in different sequences and ratios, have been determined by means of differential pulse voltammetry. Voltammetric measurements point toward the establishment in solution of structured oligonucleotide conformations, in which the nucleobases are well stacked altogether. Molecular dynamics simulations confirm that finding, indicating that single strands assume geometrical parameters characteristic of the B-DNA form. The analysis of the voltammetric signals in terms of a simple effective tight binding quantum model leads one to infer a robust set of parameters for treating hole transfer in one-electron-oxidized DNA containing adenines and thymines. PMID:23837863

Capobianco, Amedeo; Caruso, Tonino; Celentano, Maurizio; D'Ursi, Anna Maria; Scrima, Mario; Peluso, Andrea

2013-08-01

453

System for inspection of stacked cargo containers  

DOEpatents

The present invention relates to a system for inspection of stacked cargo containers. One embodiment of the invention generally comprises a plurality of stacked cargo containers arranged in rows or tiers, each container having a top, a bottom a first side, a second side, a front end, and a back end; a plurality of spacers arranged in rows or tiers; one or more mobile inspection devices for inspecting the cargo containers, wherein the one or more inspection devices are removeably disposed within the spacers, the inspection means configured to move through the spacers to detect radiation within the containers. The invented system can also be configured to inspect the cargo containers for a variety of other potentially hazardous materials including but not limited to explosive and chemical threats.

Derenzo, Stephen (Pinole, CA)

2011-08-16

454

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

455

Enhanced flue gas conditioning study. Final report for Task 7.20  

SciTech Connect

Many electrostatic precipitators (ESPS) do not achieve acceptable particulate removal efficiencies because of high-resistivity ash. One method to improve ESP performance is to employ chemical conditioning agents to reduce fly ash resistivity. Widely used agents include sulfur trioxide (SO{sub 3}) and ammonia, which are sometimes used simultaneously. For some fly ashes, that have a low affinity for SO{sub 3}, conditioning with SO{sub 3} alone is not adequate to reduce resistivity without excessive amounts of SO{sub 3} exiting the stack. In such cases, the use of ammonia in addition to SO{sub 3} may reduce the amount of required SO{sub 3} and prevent the emission of excess SO{sub 3} out of the stack. The general objective of the work was to test enhanced flue gas conditioning methods to improve the performance of ESPS. Specific objectives were to (1) verify the relationship between the required SO{sub 3} injection rates to maintain the desired fly ash resistivity and temperature for four coals, (2) verify that dual conditioning with both ammonia and SO{sub 3} promotes SO{sub 3} utilization and allows for resistivity modification with moderate SO{sub 3} injection rates, and (3) verify the effectiveness and practicality of an enhanced flue gas conditioning (EFGC) method. The EFGC method is a proprietary development of Wahlco, Inc.

Miller, S.J.; Laudal, D.L.

1991-11-01

456

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

457

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

458

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

459

Design of experiment approach for the optimization of polybrominated diphenyl ethers determination in fine airborne particulate matter by microwave-assisted extraction and gas chromatography coupled to tandem mass spectrometry.  

PubMed

A sensitive and selective procedure for the determination of 12 polybrominated diphenyl ethers (BDE-28, BDE-49, BDE-47, BDE-66, BDE-100, BDE-119, BDE-99, BDE-155, BDE-154, BDE-153, BDE-139 and BDE-183) in airbone particulate matter (PM2.5) at trace level has been developed. The proposed method includes extraction PM2.5-bound PBDEs by microwave-assisted extraction (MAE) followed by gel permeation chromatography (GPC) clean-up and determination by GC-MS/MS using a programmed temperature vaporizer (PTV) in large volume injection (LVI) mode to introduce the sample to the chromatographic system. A design of experiment (DoE) approach was used for the optimization of large volume injection and microwave-assisted extraction parameters to improve these techniques efficiency. Other conditions of the method were studied: GC-MS/MS parameters, extraction solvent and matrix effect. The limit of quantification ranged from 0.063pgm(-3) to 0.210pgm(-3) when air volumes of 723m(3) were collected. Recoveries ranged from 80% to 106%. The method was successfully applied to eight real samples collected from a residential area of the monitoring network of the Region of Valencia Government (Spain) during April-August 2012. BDE-47 and BDE-99 were quantified in six and five samples respectively. The concentrations were ranged from 0.063 to 0.112pgm(-3) for BDE-47, and from 0.107 to 0.212pgm(-3) for BDE-99. PMID:24290225

Beser, Maria Isabel; Beltrán, Joaquim; Yusà, Vicent

2014-01-01

460

Subsea BOP stack built for Caspian drilling  

SciTech Connect

This paper reports that Shaffer Inc. completed construction of a multi-million dollar subsea drilling system for Caspmorneftegas, an operating company in the Republic of Azerbaijan. The subsea stack will be installed on the semisubmersible drilling rig Shelf 7 currently under construction in Astrakan in the Soviet Union. Shelf 7 will drill wells in the Caspian Sea, one of the most prolific production areas in the Soviet Union.

Not Available

1991-12-16

461

IAS Stacking Library in IDL (Bethermin+, 2010)  

NASA Astrophysics Data System (ADS)

Number counts reach 35uJy, 3.5mJy and 40mJy at 24um, 70um, and 160um, respectively. We reach deeper flux densities of 0.38mJy at 70, and 3.1 at 160um with a stacking analysis. Products (point spread function, counts, CIB, contributions, software) are publicly available for download at http://www.ias.u-psud.fr/irgalaxies/ (2 data files).

Bethermin, M.; Dole, H.; Beelen, A.; Aussel, H.

2010-04-01

462

CPW-fed stacked microstrip antennas  

Microsoft Academic Search

This paper presents a systematic parameter study of aperture-coupled stacked patch antennas fed by coplanar waveguide. These antennas are to be used at millimeter-wave frequencies in the 30-GHz range. The influence of the most important design parameters, such as patch dimensions, aperture dimensions, and substrate thicknesses, was studied extensively. It has been found that these antennas can easily be impedance-matched

Steven Mestdagh; Walter De Raedt; Guy A. E. Vandenbosch

2004-01-01

463

Fast beam stacking using rf barriers  

SciTech Connect

Two barrier RF systems were fabricated, tested and installed in the Fermilab Main Injector. Each can provide 8 kV rectangular pulses (the RF barriers) at 90 kHz. When a stationary barrier is combined with a moving barrier, injected beams from the Booster can be continuously deflected, folded and stacked in the Main Injector, which leads to doubling of the beam intensity. This paper gives a report on the beam experiment using this novel technology.

Chou, W.; Capista, D.; Griffin, J.; Ng, K.-Y.; Wildman, D.; /Fermilab

2007-06-01

464

Enabling technologies for 3D chip stacking  

Microsoft Academic Search

This paper presents several key technologies developed for high density 3D integration by circuit stacking, i.e. with an inter-strata connection pitch lower than 10 mum. Direct bonding technology, die-to-wafer self-assembly, wafer thinning process and copper TSV process are discussed. 2 mum to 5 mum large copper TSV chains are presented with a TSV resistance <200 mOmega. Substrate noise due to

Patrick Leduc; L. Di Cioccio; B. Charlet; M. Rousseau; M. Assous; D. Bouchu; A. Roule; M. Zussy; P. Gueguen; A. Roman; O. Rozeau; M. Heitzmann; J.-P. Nieto; L. Vandroux; P.-H. Haumesser; R. Quenouillere; A. Toffoli; P. Sixt; S. Maitrejean; L. Clavelier; N. Sillon

2008-01-01

465

CAM and stack air sampler design guide  

SciTech Connect

About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from `H` and `F` area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system.

Phillips, T.D.

1994-05-13

466

Measuring Particulate Emissions from Autos  

NSDL National Science Digital Library

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

Willey, Babe

2011-03-10

467

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

468

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

469

Transparent organic photodiodes stacked with electroluminescence devices  

NASA Astrophysics Data System (ADS)

Stacked devices that consisted of transparent organic photodiodes (TOPDs) and organic electroluminescence devices (OELs) were demonstrated. TOPDs were prepared by poly-(2-methoxy-5- (2'-ethylhexyloxy)-1,4-phenylene vinylene (MEH-PPV) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend films as an active layer and transparent Au cathode (10 nm thick). These TOPDs showed about 45 % transmittance on average in visible light region (380-780 nm) and good correlation between incident light intensity and output photocurrent. Based on these results, the stacked devices were prepared by introducing OELs on TOPDs through a SiO insulating layer. The structure of OELs was ITO/Carbon/TPD/Alq3/LiF/Al. These stacked devices work as light emitting devices and also photo diodes. Since TOPDs have transparency, OELs can illuminate a paper put on the glass substrate through TOPDs and TOPDs can receive reflective light from the paper. Although the TOPDs also absorb light from OELs directly, the output signals from TOPDs changed according to the black and white pattern of the paper. These results show that the devices act as an image sensor having light emitting layer and light receiving layer in a same area.

Komatsu, Takahiro; Sakanoue, Kei; Fujita, Katsuhiko; Tsutsui, Tetsuo

2005-10-01

470

Electrostatic Nonintrusive Method for Measuring the Electric Charge, Mass Flow Rate, and Velocity of Particulates in the Two-Phase Gas–Solid Pipe Flows—Its Only or as Many as 50 Years of Historical Evolution  

Microsoft Academic Search

There are a lot of different noncontact methods for measuring the electric charges carried on solid particles, the mass flow rate, concentration, volume loading, mean flow velocity, and other flow electrical and mechanical parameters in the two- and multiphase gas-solid flows as those in pneumatic conveyance, in the air, etc. One of the methods is that based on the phenomenon

Juliusz B. Gajewski

2008-01-01

471

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