40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2010 CFR

2010-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts.

PubMed

Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

2017-02-18

Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor.

Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts

PubMed Central

Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

2017-01-01

Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor. PMID:28218700

40 CFR 60.4855 - How do I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic...

Code of Federal Regulations, 2011 CFR

2011-07-01

... I do not use a wet scrubber, fabric filter, electrostatic precipitator, or activated carbon... I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic... emission limits? If you use an air pollution control device other than a wet scrubber, fabric filter...

40 CFR 60.4855 - How do I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic...

Code of Federal Regulations, 2012 CFR

2012-07-01

... I do not use a wet scrubber, fabric filter, electrostatic precipitator, or activated carbon... I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic... emission limits? If you use an air pollution control device other than a wet scrubber, fabric filter...

40 CFR 60.4855 - How do I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic...

Code of Federal Regulations, 2014 CFR

2014-07-01

... I do not use a wet scrubber, fabric filter, electrostatic precipitator, or activated carbon... I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic... emission limits? If you use an air pollution control device other than a wet scrubber, fabric filter...

40 CFR 60.4855 - How do I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic...

Code of Federal Regulations, 2013 CFR

2013-07-01

... I do not use a wet scrubber, fabric filter, electrostatic precipitator, or activated carbon... I establish operating limits if I do not use a wet scrubber, fabric filter, electrostatic... emission limits? If you use an air pollution control device other than a wet scrubber, fabric filter...

Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions.

PubMed

Huang, R; Agranovski, I; Pyankov, O; Grinshpun, S

2008-04-01

Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approximately 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +/- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. Recirculated air in HVAC systems used for indoor air quality control in buildings often contains considerable number of viable bioaerosol particles because of limited efficiency of the filters installed in these systems. In the present study, we investigated - using aerosolized bacterial cells, bacterial and fungal spores, and virus-carrying particles - a novel idea of enhancing the performance of a low-efficiency HVAC filter utilizing continuous emission of unipolar ions in the filter vicinity. The findings described in this paper, together with our previously published results for non-biological particles, demonstrate the feasibility of the newly developed approach.

Wiring design for the control of electromagnetic interference (EMI)

NASA Technical Reports Server (NTRS)

Kopasakis, George

1995-01-01

Wiring design is only one important aspect of EMI control. Other important areas for EMI are: circuit design, filtering, grounding, bonding, shielding, lighting, electrostatic discharge (ESD), transient suppression, and electromagnetic pulse (EMP). Topics covered include: wire magnetic field emissions at low frequencies; wire radiated magnetic field emissions at frequencies; wire design guidelines for EMI control; wire design guidelines for EMI control; high frequency emissions from cables; and pulse frequency spectra.

Review of the state-of-the-art of exhaust particulate filter technology in internal combustion engines.

PubMed

Guan, Bin; Zhan, Reggie; Lin, He; Huang, Zhen

2015-05-01

The increasingly stringent emission regulations, such as US 2010, Tier 2 Bin 5 and beyond, off-road Tier 4 final, and Euro V/5 for particulate matter (PM) reduction applications, will mandate the use of the diesel particulate filters (DPFs) technology, which is proven to be the only way that can effectively control the particulate emissions. This paper covers a comprehensive overview of the state-of-the-art DPF technologies, including the advanced filter substrate materials, the novel catalyst formulations, the highly sophisticated regeneration control strategies, the DPF uncontrolled regenerations and their control methodologies, the DPF soot loading prediction, and the soot sensor for the PM on-board diagnostics (OBD) legislations. Furthermore, the progress of the highly optimized hybrid approaches, which involves the integration of diesel oxidation catalyst (DOC) + (DPF, NOx reduction catalyst), the selective catalytic reduction (SCR) catalyst coated on DPF, as well as DPF in the high-pressure exhaust gas recirculation (EGR) loop systems, is well discussed. Besides, the impacts of the quality of fuel and lubricant on the DPF performance and the maintenance and retrofit of DPF are fully elaborated. Meanwhile, the high efficiency gasoline particulate filter (GPF) technology is being required to effectively reduce the PM and particulate number (PN) emissions from the gasoline direct injection (GDI) engines to comply with the future increasingly stricter emissions regulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR Appendix Vi to Part 86 - Vehicle and Engine Components

Code of Federal Regulations, 2010 CFR

2010-07-01

... exhaust valves. (2) Drive belts. (3) Manifold and cylinder head bolts. (4) Engine oil and filter. (5...) Carburetor-idle RPM, mixture ratio. (3) Choke mechanism. (4) Fuel system filter and fuel system lines and... filter breather cap. (4) Manifold inlet (carburetor spacer, etc.). V. External Exhaust Emission Control...

40 CFR Appendix Vi to Part 86 - Vehicle and Engine Components

Code of Federal Regulations, 2012 CFR

2012-07-01

... exhaust valves. (2) Drive belts. (3) Manifold and cylinder head bolts. (4) Engine oil and filter. (5...) Carburetor-idle RPM, mixture ratio. (3) Choke mechanism. (4) Fuel system filter and fuel system lines and... filter breather cap. (4) Manifold inlet (carburetor spacer, etc.). V. External Exhaust Emission Control...

40 CFR Appendix Vi to Part 86 - Vehicle and Engine Components

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (2) Drive belts. (3) Manifold and cylinder head bolts. (4) Engine oil and filter. (5) Engine coolant...) Carburetor-idle RPM, mixture ratio. (3) Choke mechanism. (4) Fuel system filter and fuel system lines and... filter breather cap. (4) Manifold inlet (carburetor spacer, etc.). V. External Exhaust Emission Control...

40 CFR Appendix Vi to Part 86 - Vehicle and Engine Components

Code of Federal Regulations, 2013 CFR

2013-07-01

... exhaust valves. (2) Drive belts. (3) Manifold and cylinder head bolts. (4) Engine oil and filter. (5...) Carburetor-idle RPM, mixture ratio. (3) Choke mechanism. (4) Fuel system filter and fuel system lines and... filter breather cap. (4) Manifold inlet (carburetor spacer, etc.). V. External Exhaust Emission Control...

40 CFR Appendix Vi to Part 86 - Vehicle and Engine Components

Code of Federal Regulations, 2011 CFR

2011-07-01

... exhaust valves. (2) Drive belts. (3) Manifold and cylinder head bolts. (4) Engine oil and filter. (5...) Carburetor-idle RPM, mixture ratio. (3) Choke mechanism. (4) Fuel system filter and fuel system lines and... filter breather cap. (4) Manifold inlet (carburetor spacer, etc.). V. External Exhaust Emission Control...

40 CFR 420.21 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... emission control system that utilizes filters to remove iron-bearing particles (fines) from blast furnace...-tetrachlorodibenzofuran, the minimum level is 10 pg/L per EPA Method 1613B for water and wastewater samples. (d) The term... term wet air pollution control system means an emission control system that utilizes water to clean...

On-road, in-use gaseous emission measurements by remote sensing of school buses equipped with diesel oxidation catalysts and diesel particulate filters.

PubMed

Burgard, Daniel A; Provinsal, Melissa N

2009-12-01

A remote sensing device was used to obtain on-road and in-use gaseous emission measurements from three fleets of schools buses at two locations in Washington State. This paper reports each fleet's carbon monoxide (CO), hydrocarbon (HC), nitric oxide (NO), and nitrogen dioxide (NO2) mean data. The fleets represent current emission retrofit technologies, such as diesel particulate filters and diesel oxidation catalysts, and a control fleet. This study shows that CO and HC emissions decrease with the use of either retrofit technology when compared with control buses of the same initial emission standards. The CO and HC emission reductions are consistent with published U.S. Environmental Protection Agency verified values. The total oxides of nitrogen (NOx), NO, and the NO2/NOx ratio all increase with each retrofit technology when compared with control buses. As was expected, the diesel particulate filters emitted significantly higher levels of NO2 than the control fleet because of the intentional conversion of NO to NO2 by these systems. Most prior research suggests that NOx emissions are unaffected by the retrofits; however, these previous studies have not included measurements from retrofit devices on-road and after nearly 5 yr of use. Two 2006 model-year buses were also measured. These vehicles did not have retrofit devices but were built to more stringent new engine standards. Reductions in HCs and NOx were observed for these 2006 vehicles in comparison to other non-retrofit earlier model-year vehicles.

MUNICIPAL WASTE COMBUSTION MULTIPOLLUTANT STUDY EMISSION TEST REPORT, MAINE ENERGY RECOVERY COMPANY, RE- FUSE DERIVED FUEL FACILITY, BIDDEFORD, MAINE - VOLUME I: SUMMARY OF RESULTS

EPA Science Inventory

The report gives results of an emission test of a new municipal solid waste combustor, in Biddeford, ME, that burns refuse-derived fuel and is equipped with a lime spray dryer fabric filter (SD/FF) emission control system. ontrol efficiency of the SD/FF emission control system wa...

Optical filters for wavelength selection in fluorescence instrumentation.

PubMed

Erdogan, Turan

2011-04-01

Fluorescence imaging and analysis techniques have become ubiquitous in life science research, and they are poised to play an equally vital role in in vitro diagnostics (IVD) in the future. Optical filters are crucial for nearly all fluorescence microscopes and instruments, not only to provide the obvious function of spectral control, but also to ensure the highest possible detection sensitivity and imaging resolution. Filters make it possible for the sample to "see" light within only the absorption band, and the detector to "see" light within only the emission band. Without filters, the detector would not be able to distinguish the desired fluorescence from scattered excitation light and autofluorescence from the sample, substrate, and other optics in the system. Today the vast majority of fluorescence instruments, including the widely popular fluorescence microscope, use thin-film interference filters to control the spectra of the excitation and emission light. Hence, this unit emphasizes thin-film filters. After briefly introducing different types of thin-film filters and how they are made, the unit describes in detail different optical filter configurations in fluorescence instruments, including both single-color and multicolor imaging systems. Several key properties of thin-film filters, which can significantly affect optical system performance, are then described. In the final section, tunable optical filters are also addressed in a relative comparison.

Formaldehyde emissions from ventilation filters under different relative humidity conditions.

PubMed

Sidheswaran, Meera; Chen, Wenhao; Chang, Agatha; Miller, Robert; Cohn, Sebastian; Sullivan, Douglas; Fisk, William J; Kumagai, Kazukiyo; Destaillats, Hugo

2013-05-21

Formaldehyde emissions from fiberglass and polyester filters used in building heating, ventilation, and air conditioning (HVAC) systems were measured in bench-scale tests using 10 and 17 cm(2) coupons over 24 to 720 h periods. Experiments were performed at room temperature and four different relative humidity settings (20, 50, 65, and 80% RH). Two different air flow velocities across the filters were explored: 0.013 and 0.5 m/s. Fiberglass filters emitted between 20 and 1000 times more formaldehyde than polyester filters under similar RH and airflow conditions. Emissions increased markedly with increasing humidity, up to 10 mg/h-m(2) at 80% RH. Formaldehyde emissions from fiberglass filters coated with tackifiers (impaction oils) were lower than those from uncoated fiberglass media, suggesting that hydrolysis of other polymeric constituents of the filter matrix, such as adhesives or binders was likely the main formaldehyde source. These laboratory results were further validated by performing a small field study in an unoccupied office. At 80% RH, indoor formaldehyde concentrations increased by 48-64%, from 9-12 μg/m(3) to 12-20 μg/m(3), when synthetic filters were replaced with fiberglass filtration media in the HVAC units. Better understanding of the reaction mechanisms and assessing their overall contributions to indoor formaldehyde levels will allow for efficient control of this pollution source.

Evaluation of a disposable diesel exhaust filter for permissible mining machines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ambs, J.L.; Cantrell, B.K.; Watts, W.F.

1994-01-01

The US Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mines using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterbath exhaust conditioners. These were evaluated in three underground mines to determine their effectiveness inmore » reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90% at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.« less

Filter-based control of particulate matter from a lean gasoline direct injection engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, II, James E; Lewis Sr, Samuel Arthur; DeBusk, Melanie Moses

New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDImore » PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal. In addition, lean GDI engine exhaust temperatures are generally higher than diesel engines which results in more continuous regeneration of the GPF and less presence of the soot cake layer common to diesel particulate filters. Since the soot layer improves filtration efficiency, this distinction is important to consider. Research on the emission control of PM from a lean GDI engine with a GPF was conducted on an engine dynamometer. PM, after dilution, was characterized with membrane filters, organic vs. elemental carbon characterization, and size distribution techniques at various steady state engine speed and load points. The engine was operated in three primary combustion modes: stoichiometric, lean homogeneous, and lean stratified. In addition, rich combustion was utilized to simulate PM from engine operation during active regeneration of lean NOx control technologies. High (>95%) PM filtration efficiencies were observed over a wide range of conditions; however, some PM was observed to slip through the GPF at high speed and load conditions. The PM characterization at various engine speeds and loads will help enable optimized GPF design and control to achieve more fuel efficient lean GDI vehicles with low PM emissions.« less

Particulate Emissions Control using Advanced Filter Systems: Final Report for Argonne National Laboratory, Corning Inc. and Hyundai Motor Company CRADA Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seong, Hee Je; Choi, Seungmok

2015-10-09

This is a 3-way CRADA project working together with Corning, Inc. and Hyundai Motor Co. (HMC). The project is to understand particulate emissions from gasoline direct-injection engines (GDI) and their physico-chemical properties. In addition, this project focuses on providing fundamental information about filtration and regeneration mechanisms occurring in gasoline particulate filter (GPF) systems. For the work, Corning provides most advanced filter substrates for GPF applications and HMC provides three-way catalyst (TWC) coating services of these filter by way of a catalyst coating company. Then, Argonne National Laboratory characterizes fundamental behaviors of filtration and regeneration processes as well as evaluated TWCmore » functionality for the coated filters. To examine aging impacts on TWC and GPF performance, the research team evaluates gaseous and particulate emissions as well as back-pressure increase with ash loading by using an engine-oil injection system to accelerate ash loading in TWC-coated GPFs.« less

Filter Sensing Technologies

ScienceCinema

Sappok, Alex; Herman, Andrew; Parks, Jim; Prikhodko, Vitaly

2018-06-12

Leaders from Filter Sensing Technologies, CTS Corporation, and Oak Ridge National Laboratory discuss how a small business developed an award-winning diesel emissions control sensor with support from the DOE Vehicle Technologies Office and researchers at ORNL’s National Transportation Research Center.

EMISSION TEST REPORT, OMSS FIELD TEST ON CARBON INJECTION FOR MERCURY CONTROL

EPA Science Inventory

The report discusses results of a parametric evaluation of powdered activated carbon for control of mercury (Hg) emission from a municipal waste cornbustor (MWC) equipped with a lime spray dryer absorber/fabric filter (SD/FF). The primary test objectives were to evaluate the effe...

40 CFR 1051.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2013 CFR

2013-07-01

... necessary. This might include adding engine oil, changing air, fuel, or oil filters, servicing engine... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Emission... the maintenance will be done at the recommended interval on in-use engines. In considering your...

40 CFR 1051.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2012 CFR

2012-07-01

... necessary. This might include adding engine oil, changing air, fuel, or oil filters, servicing engine... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Emission... the maintenance will be done at the recommended interval on in-use engines. In considering your...

40 CFR 1051.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2011 CFR

2011-07-01

... necessary. This might include adding engine oil, changing air, fuel, or oil filters, servicing engine... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Emission... the maintenance will be done at the recommended interval on in-use engines. In considering your...

40 CFR 1051.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2014 CFR

2014-07-01

... necessary. This might include adding engine oil, changing air, fuel, or oil filters, servicing engine... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Emission... the maintenance will be done at the recommended interval on in-use engines. In considering your...

BENCH-SCALE EVALUATION OF CALCIUM SORBENTS FOR ACID GAS EMISSION CONTROL

EPA Science Inventory

Calcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO2/HCl and SO2/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench-scale reactor (fixed-bed) simulating fabric filter conditions in an acid gas remova...

Baumot BA-B Diesel Particulate Filter with Pre-Catalyst (ETV Mobile Source Emissions Control Devices) Verification Report

EPA Science Inventory

The Baumot BA-B Diesel Particulate Filter with Pre-Catalyst is a diesel engine retrofit device for light, medium, and heavy heavy-duty diesel on-highway engines for use with commercial ultra-low-sulfur diesel (ULSD) fuel. The BA-B particulate filter is composed of a pre-catalyst ...

Verification of a level-3 diesel emissions control strategy for transport refrigeration units

NASA Astrophysics Data System (ADS)

Shewalla, Umesh

Transport Refrigeration Units (TRUs) are refrigeration systems used to control the environment of temperature sensitive products while they are being transported from one place to another in trucks, trailers or shipping containers. The TRUs typically use an internal combustion engine to power the compressor of the refrigeration unit. In the United States TRUs are most commonly powered by diesel engines which vary from 9 to 40 horsepower. TRUs are capable of both heating and cooling. The TRU engines are relatively small, inexpensive and do not use emissions reduction techniques such as exhaust gas recirculation (EGR). A significant number of these engines operate in highly populated areas like distribution centers, truck stops, and other facilities which make them one of the potential causes for health risks to the people who live and work nearby. Diesel particulate matter (PM) is known for its adverse effects on both human beings and the environment. Considering these effects, regulatory bodies have imposed limitations on the PM emissions from a TRU engine. The objective of this study was to measure and analyze the regulated emissions from a TRU engine under both engine out and particulate filter system out conditions during pre-durability (when the filter system was new) and post-durability test (after the filter system was subjected to 1000 hours in-field trial). The verification program was performed by the Center for Alternative Fuel, Engines and Emissions (CAFEE) at West Virginia University (WVU). In this program, a catalyzed silicon carbide (SiC) diesel particulate filter (DPF) was evaluated and verified as a Level-3 Verified Diesel Emissions Control Strategy (VDECS) (. 85% PM reduction) under California Air Resources Board (CARB) regulations 2702 [1]. The emissions result showed that the filter system reduced diesel PM by a percentage of 96 +/- 1 over ISO 8178-C1 [2] cycle and 92 +/- 5 over EPA TRU [3] cycle, qualifying as a Level 3 VDECS. The percentage emission reduction in hydrocarbons (HC) and carbon monoxide (CO) was 76.8 +/- 4.8 and 72.2 +/- 5.2, respectively over both ISO 8178-C1 [2] and EPA TRU [3] cycles. It was also observed that there was 3.6 +/- 2.9 and 7.2 +/- 3.1 percentage reduction in oxides of nitrogen (NOx) and nitric oxide (NO), respectively with a slight increase in fuel consumption and carbon dioxide as a consequence of increased exhaust back pressure. It is required by the CARB regulations that the diesel emissions control strategy must not increase emissions of NO2 by more than 20% by mass over the baseline value. In this study, it was observed that the total increase in NO2 level was 5.6 +/- 2.6 percent, well within the limit specified by the CARB.

Further theoretical studies of modified cyclone separator as a diesel soot particulate emission arrester.

PubMed

Mukhopadhyay, N; Bose, P K

2009-10-01

Soot particulate emission reduction from diesel engine is one of the most emerging problems associated with the exhaust pollution. Diesel particulate filters (DPF) hold out the prospects of substantially reducing regulated particulate emissions but the question of the reliable regeneration of filters still remains a difficult hurdle to overcome. Many of the solutions proposed to date suffer from design complexity, cost, regeneration problem and energy demands. This study presents a computer aided theoretical analysis for controlling diesel soot particulate emission by cyclone separator--a non contact type particulate removal system considering outer vortex flow, inner vortex flow and packed ceramic fiber filter at the end of vortex finder tube. Cyclone separator with low initial cost, simple construction produces low back pressure and reasonably high collection efficiencies with reduced regeneration problems. Cyclone separator is modified by placing a continuous ceramic packed fiber filter placed at the end of the vortex finder tube. In this work, the grade efficiency model of diesel soot particulate emission is proposed considering outer vortex, inner vortex and the continuous ceramic packed fiber filter. Pressure drop model is also proposed considering the effect of the ceramic fiber filter. Proposed model gives reasonably good collection efficiency with permissible pressure drop limit of diesel engine operation. Theoretical approach is predicted for calculating the cut size diameter considering the effect of Cunningham molecular slip correction factor. The result shows good agreements with existing cyclone and DPF flow characteristics.

FABRIC FILTER MODEL FORMAT CHANGE; VOLUME II. USER'S GUIDE

EPA Science Inventory

The report describes an improved mathematical model for use by control personnel to determine the adequacy of existing or proposed filter systems designed to minimize coal fly ash emissions. Several time-saving steps have been introduced to facilitate model application by Agency ...

Behavior or Nonmetallic Materials in Shale Oil Derived Jet Fuels and in High Aromatic and High Sulfur Petroleum Fuels

DTIC Science & Technology

1978-07-01

degrades thermal stability and forms undesirable sulfur dioxide emissions . Although the original premises for controlling total sulfur may not still...eliminate corrosive trace contamination, presence of surfactants which deactivate filter/ separators, carry-over of refinery processing materials, and...increase raw vapor emissions from ground fuel handling facilities and during refueling operations. Controlling raw vapor emissions is difficult at 3

Particulate generation and control in the PREPP (Process Experimental Pilot Plant) incinerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stermer, D.L.; Gale, L.G.

1989-03-01

Particulate emissions in radioactive incineration systems using a wet scrubbing system are generally ultimately controlled by flowing the process offgas stream through a high-efficiency filter, such as a High Efficient Particulate Air (HEPA) filter. Because HEPA filters are capable of reducing particulate emissions over an order of magnitude below regulatory limits, they consequently are vulnerable to high loading rates. This becomes a serious handicap in radioactive systems when filter change-out is required at an unacceptably high rate. The Process Experimental Pilot Plant (PREPP) incineration system is designed for processing retrieved low level mixed hazardous waste. It has a wet offgasmore » treatment system consisting of a Quencher, Venturi Scrubber, Entrainment Eliminator, Mist Eliminator, two stages of HEPA filters, and induced draft fans. During previous tests, it was noted that the offgas filters loaded with particulate at a rate requiring replacement as often as every four hours. During 1988, PREPP conducted a series of tests which included an investigation of the causes of heavy particulate accumulation on the offgas filters in relation to various operating parameters. This was done by measuring the particulate concentrations in the offgas system, primarily as a function of scrub solution salt concentration, waste feed rate, and offgas flow rate. 2 figs., 9 tabs.« less

FABRIC FILTER MODEL FORMAT CHANGE; VOLUME 1. DETAILED TECHNICAL REPORT

EPA Science Inventory

The report describes an improved mathematical model for use by control personnel to determine the adequacy of existing or proposed filter systems designed to minimize coal fly ash emissions. Several time-saving steps have been introduced to facilitate model application by Agency ...

Evaluation of a disposable diesel exhaust filter for permissible mining machines. Report of investigations/1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ambs, J.L.; Cantrell, B.K.; Watts, W.F.

1994-01-01

The U.S. Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mining using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterban exhaust conditioners. These were evaluated in three underground mines to determine their effectiveness inmore » reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90 pct at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.« less

Selective catalyst reduction light-off strategy

DOEpatents

Gonze, Eugene V [Pinckney, MI

2011-10-18

An emissions control system includes a temperature determination module and an emissions control module. The temperature determination module determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and determines a second temperature of a catalyst of the DPF assembly. The emissions control module selectively activates the heater element, selectively initiates a predefined combustion process in an engine based upon the first temperature, and selectively starts a reductant injection process based upon the second temperature.

Effects of Retrofitting Emission Control Systems on all In-Use Heavy Diesel Trucks

NASA Astrophysics Data System (ADS)

Millstein, D.; Harley, R. A.

2009-12-01

Diesel exhaust is now the largest source of nitrogen oxide (NOx) emissions nationally in the US, and contributes significantly to emissions of fine particulate black carbon (soot) as well. New national standards call for dramatically lower emissions of exhaust particulate matter (PM) and NOx from new diesel engines starting in 2007 and 2010, respectively. Unfortunately it will take decades for the cleaner new engines to replace those currently in service on existing heavy-duty trucks. The state of California recently adopted a rule to accelerate fleet turnover in the heavy-duty truck sector, requiring that all in-use trucks meet the new exhaust PM standards by 2014. This will entail retrofit of diesel particle filters or replacement for over a million existing diesel engines. Diesel particle filters can replace the muffler on existing trucks, and there is extensive experience with retrofit of this control equipment on public sector fleets such as diesel-powered transit buses. Nitrogen dioxide (NO2) is used as an oxidizing agent to remove carbon particles from the particle filter, to prevent it from becoming plugged. To create the needed NO2, NOx already present in engine exhaust as nitric oxide (NO) is deliberately oxidized to NO2 upstream of the particle filter using a platinum catalyst. The NO2/NOx ratio in exhaust emissions therefore increases to ~35% in comparison to much lower values (~5%) typical of older engines without particle filters. We evaluate the effects on air quality of increased use of diesel particle traps and NOx controls in southern California using the Community Multiscale Air Quality (CMAQ) model. Compared to a reference scenario without the retrofit program, we found black carbon concentrations decreased by ~20%, with small increases (4%) in ambient ozone concentrations. During summer, average NO2 concentrations decrease despite the increase in primary NO2 emissions - because total NOx emissions are reduced as part of a parallel but more gradual program to retrofit NOx control systems on in-use engines. During winter, NO2 concentrations increase by 1-2% at locations with high diesel truck traffic, and larger increases may occur if diesel trucks outfitted with particle traps do not meet the in-use NOx emission reduction requirements. Small changes to fine particulate nitrate are seen as well with increases over the Los Angeles area of 3 and 6% during the summer and fall, respectively. During the summer, but not the fall, downwind nitrate decreased by 2% east of Los Angeles near Riverside. Emissions reductions due to fleet turnover in the reference scenario (without retrofit) may be optimistic, and the air quality benefits of retrofits could therefore be understated, due to slow sales of new engines in recent years. In any case, significant changes in diesel engine emissions of NOx and PM are expected to occur over the next 5 years in California.

IDENTIFICATION AND EMISSION FACTORS OF MOLECULAR TRACERS IN ORGANIC AEROSOLS FROM BIOMASS BURNING PART 1. TEMPERATE CLIMATE CONIFERS. (R823990)

EPA Science Inventory

Smoke particulate matter from conifers subjected to controlled burning, both under smoldering and flaming conditions, was sampled by high volume air filtration on precleaned quartz fiber filters. The filtered particles were extracted with dichloromethane and the crude extracts...

IDENTIFICATION AND EMISSION FACTORS OF MOLECULAR TRACERS IN ORGANIC AEROSOLS FROM BIOMASS BURNING PART 2. DECIDUOUS TREES. (R823990)

EPA Science Inventory

Smoke particulate matter from deciduous trees (angiosperms) subjected to controlled burning, both under smoldering and flaming conditions, was sampled by high volume air filtration on precleaned quartz fiber filters. The filtered particles were extracted with dichloromethane a...

40 CFR 60.275a - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... operator shall demonstrate compliance with § 60.272(a)(3) based on emissions from only the affected... used for negative-pressure fabric filters and other types of control devices and Method 5D shall be used for positive-pressure fabric filters to determine the particulate matter concentration and...

Sulfur oxide adsorbents and emissions control

DOEpatents

Li, Liyu [Richland, WA; King, David L [Richland, WA

2006-12-26

High capacity sulfur oxide absorbents utilizing manganese-based octahedral molecular sieve (Mn--OMS) materials are disclosed. An emissions reduction system for a combustion exhaust includes a scrubber 24 containing these high capacity sulfur oxide absorbents located upstream from a NOX filter 26 or particulate trap.

Controlling soot formation with filtered EGR for diesel and biodiesel fuelled engines.

PubMed

Gill, S S; Turner, D; Tsolakis, A; York, A P E

2012-04-03

Although exhaust gas recirculation (EGR) is an effective strategy for controlling the levels of nitrogen oxides (NO(X)) emitted from a diesel engine, the full potential of EGR in NO(X)/PM trade-off and engine performance (i.e., fuel economy) has not fully been exploited. Significant work into the cause and control of particulate matter (PM) has been made over the past decade with new cleaner fuels and after-treatment devices emerging to comply with the current and forthcoming emission regulations. In earlier work, we demonstrated that engine operation with oxygenated fuels (e.g., biodiesel) reduces the PM emissions and extends the engine tolerance to EGR before it reaches smoke-limited conditions. The same result has also been reported when high cetane number fuels such as gas-to-liquid (GTL) are used. To further our understanding of the relationship between EGR and PM formation, a diesel particulate filter (DPF) was integrated into the EGR loop to filter the recirculated soot particulates. The control of the soot recirculation penalty through filtered EGR (FEGR) resulted in a 50% engine-out soot reduction, thus showing the possibility of extending the maximum EGR limit or being able to run at the same level of EGR with an improved NO(X)/soot trade-off.

Effects of retrofitting emission control systems on in-use heavy diesel vehicles.

PubMed

Millstein, Dev E; Harley, Robert A

2010-07-01

Diesel engines are now the largest source of nitrogen oxides (NO(x)) and fine particulate black carbon (soot) emissions in California. The California Air Resources Board recently adopted a rule requiring that by 2014 all in-use heavy trucks and buses meet current (2007) exhaust particulate matter (PM) emission standards. Also by 2023 all in-use heavy-duty vehicles will have to meet current NO(x) emission standards, with significant progress in achieving the requirements for NO(x) control expected by 2014. This will require retrofit or replacement of older in-use engines. Diesel particle filters (DPF) reduce PM emissions but may increase the NO(2)/NO(x) emission ratio to approximately 35%, compared to approximately 5% typical of diesel engines without particle filters. Additionally, DPF with high oxidative capacity reduce CO and hydrocarbon emissions. We evaluate the effects of retrofitting trucks with DPF on air quality in southern California, using an Eulerian photochemical air quality model. Compared to a 2014 reference scenario without the retrofit program, black carbon concentrations decreased by 12 +/- 2% and 14 +/- 2% during summer and fall, respectively, with corresponding increases in ambient ozone concentrations of 3 +/- 2% and 7 +/- 3%. NO(2) concentrations decreased by 2-4% overall despite the increase in primary NO(2) emissions because total NO(x) emissions were reduced as part of the program to retrofit NO(x) control systems on in-use engines. However, in some cases NO(2) concentrations may increase at locations with high diesel truck traffic.

ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF MOBILE SOURCE EMISSIONS CONTROL DEVICES: CLEAN DIESEL TECHNOLOGIES FUEL-BORNE CATALYST WITH MITSUI/PUREARTH CATALYZED WIRE MESH FILTER

EPA Science Inventory

The Environmental Technology Verification report discusses the technology and performance of the Fuel-Borne Catalyst with Mitsui/PUREarth Catalyzed Wire Mesh Filter manufactured by Clean Diesel Technologies, Inc. The technology is a platinum/cerium fuel-borne catalyst in commerci...

Instrumental and bio-monitoring of heavy metal and nanoparticle emissions from diesel engine exhaust in controlled environment.

PubMed

Giordano, Simonetta; Adamo, Paola; Spagnuolo, Valeria; Vaglieco, Bianca Maria

2010-01-01

In the present article we characterized the emissions at the exhaust of a Common Rail (CR) diesel engine, representative of light-duty class, equipped with a catalyzed diesel particulate filter (CDPF) in controlled environment. The downstream exhausts were directly analyzed (for PM, CO, CO2, 02, HCs, NOx) by infrared and electrochemical sensors, and SEM-EDS microscope; heavy metals were chemically analyzed using mosses and lichens in bags, and glass-fibre filters all exposed at the engine exhausts. The highest particle emission value was in the 7-54 nm size range; the peak concentration rose until one order of magnitude for the highest load and speed. Particle composition was mainly carbonaceous, associated to noticeable amounts of Fe and silica fibres. Moreover, the content of Cu, Fe, Na, Ni and Zn in both moss and lichen, and of Al and Cr in moss, was significantly increased. Glass-fibre filters were significantly enriched in Al, B, Ba, Cu, Fe, Na, and Zn. The role of diesel engines as source of carbonaceous nanoparticles has been confirmed, while further investigations in controlled environment are needed to test the catalytic muffler as a possible source of silica fibres considered very hazardous for human health.

Radiated emissions comparison of seven-stage modal filter constructions for Ethernet 100Base-T network protection

NASA Astrophysics Data System (ADS)

Khazhibekov, R. R.; Zabolotsky, A. M.

2018-05-01

The authors consider Ethernet protection devices based on modal filtering. Radiated emission measurement results for three modal filter constructions are presented. It is shown that the improved construction of a non-resistive filter has lower emission levels than the original one.

Air quality benefits of universal particle filter and NOx controls on diesel trucks

NASA Astrophysics Data System (ADS)

Tao, L.; Mcdonald, B. C.; Harley, R.

2015-12-01

Heavy-duty diesel trucks are a major source of black carbon/particulate matter and nitrogen oxide emissions on urban and regional scales. These emissions are relevant to both air quality and climate change. Since 2010 in the US, new engines are required to be equipped with emission control systems that greatly reduce both PM and NOx emissions, by ~98% relative to 1988 levels. To reduce emissions from the legacy fleet of older trucks that still remain on the road, regulations have been adopted in Califonia to accelerate the replacement of older trucks and thereby reduce associated emissions of PM and NOx. Use of diesel particle filters will be widespread by 2016, and universal use of catalytic converters for NOx control is required by 2023. We assess the air quality consequences of this clean-up effort in Southern California, using the Community Multiscale Air Quality model (CMAQ), and comparing three scenarios: historical (2005), present day (2016), and future year (2023). Emissions from the motor vehicle sector are mapped at high spatial resolution based on traffic count and fuel sales data. NOx emissions from diesel engines in 2023 are expected to decrease by ~80% compared to 2005, while the fraction of NOx emitted as NO2 is expected to increase from 5 to 18%. Air quality model simulations will be analyzed to quantify changes in NO2, black carbon, particulate matter, and ozone, both basin-wide and near hot spots such as ports and major highways.

The multi-spectral line-polarization MSE system on Alcator C-Mod

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumgaard, R. T., E-mail: mumgaard@psfc.mit.edu; Khoury, M.; Scott, S. D.

A multi-spectral line-polarization motional Stark effect (MSE-MSLP) diagnostic has been developed for the Alcator C-Mod tokamak wherein the Stokes vector is measured in multiple wavelength bands simultaneously on the same sightline to enable better polarized background subtraction. A ten-sightline, four wavelength MSE-MSLP detector system was designed, constructed, and qualified. This system consists of a high-throughput polychromator for each sightline designed to provide large étendue and precise spectral filtering in a cost-effective manner. Each polychromator utilizes four narrow bandpass interference filters and four custom large diameter avalanche photodiode detectors. Two filters collect light to the red and blue of the MSEmore » emission spectrum while the remaining two filters collect the beam pi and sigma emission generated at the same viewing volume. The filter wavelengths are temperature tuned using custom ovens in an automated manner. All system functions are remote controllable and the system can be easily retrofitted to existing single-wavelength line-polarization MSE systems.« less

The multi-spectral line-polarization MSE system on Alcator C-Mod

DOE PAGES

Mumgaard, R. T.; Scott, S. D.; Khoury, M.

2016-08-17

A multi-spectral line-polarization motional Stark effect (MSE-MSLP) diagnostic has been developed for the Alcator C-Mod tokamak wherein the Stokes vector is measured in multiple wavelength bands simultaneously on the same sightline to enable better polarized background subtraction. A ten-sightline, four wavelength MSE-MSLP detector system was designed, constructed, and qualified. This system consists of a high-throughput polychromator for each sightline designed to provide large étendue and precise spectral filtering in a cost-effective manner. Each polychromator utilizes four narrow bandpass interference filters and four custom large diameter avalanche photodiode detectors. Two filters collect light to the red and blue of the MSEmore » emission spectrum while the remaining two filters collect the beam pi and sigma emission generated at the same viewing volume. The filter wavelengths are temperature tuned using custom ovens in an automated manner. Furthermore, all system functions are remote controllable and the system can be easily retrofitted to existing single-wavelength line-polarization MSE systems.« less

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

PubMed Central

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-01-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect. PMID:28252034

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

NASA Astrophysics Data System (ADS)

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-03-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect.

CONTINUED ASSESSMENT OF A HIGH-VELOCITY FABRIC FILTRATION SYSTEM USED TO CONTROL FLY ASH EMISSIONS

EPA Science Inventory

The report gives results of a full-scale investigation of the performance of a variety of filter media, to provide technical and economic information under high-velocity conditions (high gas/cloth ratio). The fly ash emission studies demonstrated that woven fiberglass fabrics and...

ETV TEST REPORT OF MOBILE SOURCE EMISSIONS CONTROL DEVICES: LUBRIZOL ENGINE CONTROL SYSTEMS PURIFILTER SC17L

EPA Science Inventory

The Environmental Technology Verification report discusses the technology and performance of the Lubrizol Engine Control Systems Purifilter SC17L manufactured by Lubrizol Engine Control Systems. The technology is a precious and base metal, passively regenerated particulate filter...

Environmental Technology Verification: Test Report of Mobile Source Emission Control Devices--Johnson Matthey PCRT2 1000, Version 2, Filter + Diesel Oxidation Catalyst

EPA Science Inventory

The Johnson Matthey PCRT2 1000, v.2 system is a partial continuously regenerating technology (PCRT) system that consists of a flow-through partial filter combined with a DOC. The system is designed for low temperature exhaust resulting from intermittent loads from medium and heav...

Developing particulate thin filter using coconut fiber for motor vehicle emission

NASA Astrophysics Data System (ADS)

Wardoyo, A. Y. P.; Juswono, U. P.; Riyanto, S.

2016-03-01

Amounts of motor vehicles in Indonesia have been recognized a sharply increase from year to year with the increment reaching to 22 % per annum. Meanwhile motor vehicles produce particulate emissions in different sizes with high concentrations depending on type of vehicles, fuels, and engine capacity. Motor Particle emissions are not only to significantly contribute the atmosphric particles but also adverse to human health. In order to reduce the particle emission, it is needed a filter. This study was aimed to develop a thin filter using coconut fiber to reduce particulate emissions for motor vehicles. The filter was made of coconut fibers that were grinded into power and mixed with glues. The filter was tested by the measurements of particle concentrations coming out from the vehicle exhaust directly and the particle concentrations after passing through the filter. The efficiency of the filter was calculated by ratio of the particle concentrations before comming in the filter to the particle conentrations after passing through the filter. The results showed that the efficiency of the filter obtained more than 30 %. The efficiency increases sharply when a number of the filters are arranged paralelly.

Effects of diesel particle filter retrofits and accelerated fleet turnover on drayage truck emissions at the Port of Oakland.

PubMed

Dallmann, Timothy R; Harley, Robert A; Kirchstetter, Thomas W

2011-12-15

Heavy-duty diesel drayage trucks have a disproportionate impact on the air quality of communities surrounding major freight-handling facilities. In an attempt to mitigate this impact, the state of California has mandated new emission control requirements for drayage trucks accessing ports and rail yards in the state beginning in 2010. This control rule prompted an accelerated diesel particle filter (DPF) retrofit and truck replacement program at the Port of Oakland. The impact of this program was evaluated by measuring emission factor distributions for diesel trucks operating at the Port of Oakland prior to and following the implementation of the emission control rule. Emission factors for black carbon (BC) and oxides of nitrogen (NO(x)) were quantified in terms of grams of pollutant emitted per kilogram of fuel burned using a carbon balance method. Concentrations of these species along with carbon dioxide were measured in the exhaust plumes of individual diesel trucks as they drove by en route to the Port. A comparison of emissions measured before and after the implementation of the truck retrofit/replacement rule shows a 54 ± 11% reduction in the fleet-average BC emission factor, accompanied by a shift to a more highly skewed emission factor distribution. Although only particulate matter mass reductions were required in the first year of the program, a significant reduction in the fleet-average NO(x) emission factor (41 ± 5%) was observed, most likely due to the replacement of older trucks with new ones.

Compliance Assurance Monitoring Technical Guidance Document Appendix A: Fabric Filter Control Devices

EPA Pesticide Factsheets

Compliance assurance monitoring is intended to provide a reasonable assurance of compliance with applicable requirements under the Clean Air Act for large emission units that rely on pollution control device equipment to achieve compliance.

Compliance Assurance Monitoring Technical Guidance Document Appendix A: Electrified Filter Bed Control Device

EPA Pesticide Factsheets

Compliance assurance monitoring is intended to provide a reasonable assurance of compliance with applicable requirements under the Clean Air Act for large emission units that rely on pollution control device equipment to achieve compliance.

DEMONSTRATION OF POTENTIAL FOR SELECTIVE CATALYTIC REDUCTION AND DIESEL PARTICULATE FILTERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGILL,R; KHAIR, M; SHARP, C

2003-08-24

This project addresses the potential for Selective Catalytic Reduction (SCR) devices (using urea as reductant) together with Diesel Particulate Filters (DPF) and low-pressure loop exhaust gas recirculation (EGR) to achieve future stringent emissions standards for heavy-duty engines powering Class 8 vehicles. Two emission control systems consisting of the three technologies (EGR, SCR, and DPF) were calibrated on a Caterpillar C-12 heavy-duty diesel engine. Results of these calibrations showed good promise in meeting the 2010 heavy-duty emission standards as set forth by the Environmental Protection Agency (EPA). These two emission control systems were developed to evaluate a series of fuels thatmore » have similar formulations except for their sulfur content. Additionally, one fuel, code-named BP15, was also evaluated. This fuel was prepared by processing straight-run distillate stocks through a commercial, single stage hydrotreater employing high activity catalyst at maximum severity. An additional goal of this program is to provide data for an on-going EPA technology review that evaluates progress toward meeting 2007/2010 emission standards. These emissions levels were to be achieved not only on the transient test cycles but in other modes of operation such as the steady-state Euro-III style emission test known as the OICA (Organisation Internationale des Compagnies d'Automobiles) or the ESC (European Stationary Cycle). Additionally, hydrocarbon and carbon monoxide emissions standards are to be met.« less

Economic comparison of fabric filters and electrostatic precipitators for particulate control on coal-fired utility boilers

NASA Technical Reports Server (NTRS)

Cukor, P. M.; Chapman, R. A.

1978-01-01

The uncertainties and associated costs involved in selecting and designing a particulate control device to meet California's air emission regulations are considered. The basic operating principles of electrostatic precipitators and fabric filters are discussed, and design parameters are identified. The size and resulting cost of the control device as a function of design parameters is illustrated by a case study for an 800 MW coal-fired fired utility boiler burning a typical southwestern subbituminous coal. The cost of selecting an undersized particulate control device is compared with the cost of selecting an oversized device.

40 CFR 60.2680 - What if I do not use a wet scrubber to comply with the emission limitations?

Code of Federal Regulations, 2011 CFR

2011-07-01

... not use a wet scrubber, fabric filter, activated carbon injection, selective noncatalytic reduction... pollution control device other than a wet scrubber, activated carbon injection, selective noncatalytic..., including mass balances, to comply with the emission limitations under § 60.2670, you must petition the EPA...

40 CFR 60.5170 - What operating limits and requirements must I meet and by when?

Code of Federal Regulations, 2011 CFR

2011-07-01

... wet scrubber, fabric filter, electrostatic precipitator, or activated carbon injection are listed in... pollution control device. (c) If you use a fabric filter to comply with the emission limits, you must install the bag leak detection system specified in §§ 60.5200(b) and 60.5225(b)(3)(i) and operate the bag...

Forced-air warming blowers: An evaluation of filtration adequacy and airborne contamination emissions in the operating room.

PubMed

Albrecht, Mark; Gauthier, Robert L; Belani, Kumar; Litchy, Mark; Leaper, David

2011-05-01

Forced-air warming (FAW) is widely used to prevent hypothermia during surgical procedures. The airflow from these blowers is often vented near the operative site and should be free of contaminants to minimize the risk of surgical site infection. Popular FAW blowers contain a 0.2-μm rated intake filter to reduce these risks. However, there is little evidence that the efficiency of the intake filter is adequate to prevent airborne contamination emissions or protect the internal air path from microbial contamination buildup. Five new intake filters were obtained directly from the manufacturer (Bair Hugger 505, model 200708D; Arizant Healthcare, Eden Prairie, MN), and 5 model 200708C filters currently in hospital use were removed from FAW devices. The retention efficiency of these filters was assessed using a monodisperse sodium chloride aerosol. In the same hospitals, internal air path surface swabs and hose outlet particle counts were performed on 52 forced-air warming devices (all with the model 200708C filter) to assess internal microbial buildup and airborne contamination emissions. Intake filter retention efficiency at 0.2 μm was 93.8% for the 200708C filter and 61.3% at for the 200708D filter. The 200708D filter obtained directly from the manufacturer has a thinner filtration media than the 200708C filter in current hospital use, suggesting that the observed differences in retention efficiency were due to design changes. Fifty-eight percent of the FAW blowers evaluated were internally generating and emitting airborne contaminants, with microorganisms detected on the internal air path surfaces of 92.3% of these blowers. Isolates of Staphylococcus aureus, coagulase-negative Staphylococcus, and methicillin-resistant S aureus were detected in 13.5%, 3.9%, and 1.9% of FAW blowers, respectively. The design of popular FAW devices using the 200708C filter was found to be inadequate for preventing the internal buildup and emission of microbial contaminants into the operating room. Substandard intake filtration allowed airborne contaminants (both viable and nonviable) to penetrate the intake filter and reversibly attach to the internal surfaces within the FAW blowers. The reintroduction of these contaminants into the FAW blower air stream was detected and could contribute to the risk of cross-infection. Given the deficiencies identified with the 200708C intake filter, the introduction of a new filter (model 200708D) with substantially lower retention efficiency is of concern. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

40 CFR 1054.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2011 CFR

2011-07-01

... schedule cleaning or changing air filters or changing spark plugs at the least frequent interval described... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND... aftertreatment devices, pulse-air valves, fuel injectors, oxygen sensors, electronic control units, superchargers...

40 CFR 1054.125 - What maintenance instructions must I give to buyers?

Code of Federal Regulations, 2010 CFR

2010-07-01

... schedule cleaning or changing air filters or changing spark plugs at the least frequent interval described... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND... aftertreatment devices, pulse-air valves, fuel injectors, oxygen sensors, electronic control units, superchargers...

40 CFR 420.21 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... control system that utilizes filters to remove iron-bearing particles (fines) from blast furnace or... level is 10 pg/L per EPA Method 1613B for water and wastewater samples. (d) The term pg/L means... pollution control system means an emission control system that utilizes water to clean process or furnace...

40 CFR 420.21 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... control system that utilizes filters to remove iron-bearing particles (fines) from blast furnace or... level is 10 pg/L per EPA Method 1613B for water and wastewater samples. (d) The term pg/L means... pollution control system means an emission control system that utilizes water to clean process or furnace...

40 CFR 420.21 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... control system that utilizes filters to remove iron-bearing particles (fines) from blast furnace or... level is 10 pg/L per EPA Method 1613B for water and wastewater samples. (d) The term pg/L means... pollution control system means an emission control system that utilizes water to clean process or furnace...

Environmental Technology Verification, Baghouse Filtration Products TTG Inc., TG800 Filtration Media (Tested August 2012)

EPA Science Inventory

Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

Donaldson Company, Inc., Dura-Life #0701607 Filtration Media(Tested October 2011) (ETV Baghouse Filtration Products) Verification Report

EPA Science Inventory

Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

Environmental Technology Verification; Baghouse Filtration Products TTG Inc., TG100 Filtration Media (Tested August 2012)

EPA Science Inventory

Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

Economical Emission-Line Mapping: ISM Properties of Nearby Protogalaxy Analogs

NASA Astrophysics Data System (ADS)

Monkiewicz, Jacqueline A.

2017-01-01

Optical emission line imaging can produce a wealth of information about the conditions of the interstellar medium, but a full set of custom emission-line filters for a professional-grade telescope camera can cost many thousands of dollars. A cheaper alternative is to use commercially-produced 2-inch narrow-band astrophotography filters. In order to use these standardized filters with professional-grade telescope cameras, custom filter mounts must be manufactured for each individual filter wheel. These custom filter adaptors are produced by 3-D printing rather than standard machining, which further lowers the total cost.I demonstrate the feasibility of this technique with H-alpha, H-beta, and [OIII] emission line mapping of the low metallicity star-forming galaxies IC10 and NGC 1569, taken with my astrophotography filter set on three different 2-meter class telescopes in Southern Arizona.

On the Origin of the Flare Emission in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral Lines?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleint, Lucia; Krucker, Säm; Heinzel, Petr

Continuum (“white-light,” WL) emission dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the emission arises from real continuum emission or enhanced spectral lines, possibly turning into emission. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral line emission to IRIS ’ SJI 2832 emission by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral line emissionmore » can contribute up to 100% to the observed slitjaw images (SJI) emission, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the lines on the emission can be significant.« less

40 CFR 63.11507 - What are my standards and management practices?

Code of Federal Regulations, 2011 CFR

2011-07-01

... distilled/de-ionized water, water filtration, pre-cleaning of parts to be plated, and thorough rinsing of... emissions from the thermal spraying process and transports the emissions to a water curtain, fabric filter... and transports the emissions to a water curtain, fabric filter, cartridge, or HEPA filter, according...

Tuning the photon statistics of a strongly coupled nanophotonic system

NASA Astrophysics Data System (ADS)

Dory, Constantin; Fischer, Kevin A.; Müller, Kai; Lagoudakis, Konstantinos G.; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L.; Kelaita, Yousif; Sapra, Neil V.; Vučković, Jelena

2017-02-01

We investigate the dynamics of single- and multiphoton emission from detuned strongly coupled systems based on the quantum-dot-photonic-crystal resonator platform. Transmitting light through such systems can generate a range of nonclassical states of light with tunable photon counting statistics due to the nonlinear ladder of hybridized light-matter states. By controlling the detuning between emitter and resonator, the transmission can be tuned to strongly enhance either single- or two-photon emission processes. Despite the strongly dissipative nature of these systems, we find that by utilizing a self-homodyne interference technique combined with frequency filtering we are able to find a strong two-photon component of the emission in the multiphoton regime. In order to explain our correlation measurements, we propose rate equation models that capture the dominant processes of emission in both the single- and multiphoton regimes. These models are then supported by quantum-optical simulations that fully capture the frequency filtering of emission from our solid-state system.

Development of Radio Frequency Diesel Particulate Filter Sensor and Controls for Advanced Low Pressure Drop Systems to Reduce Engine Fuel Consumption (06B)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sappok, Alexander; Ragaller, Paul; Bromberg, Leslie

This project developed a radio frequencybased sensor for accurate measurement of diesel particulate filter (DPF) loading with advanced low pressuredrop aftertreatment systems. The resulting technology demonstrated engine efficiency improvements through optimization of the combined engineaftertreatment system while reducing emissions, system cost, and complexity to meet the DOE program objectives.

Improvement of LOD in Fluorescence Detection with Spectrally Nonuniform Background by Optimization of Emission Filtering.

PubMed

Galievsky, Victor A; Stasheuski, Alexander S; Krylov, Sergey N

2017-10-17

The limit-of-detection (LOD) in analytical instruments with fluorescence detection can be improved by reducing noise of optical background. Efficiently reducing optical background noise in systems with spectrally nonuniform background requires complex optimization of an emission filter-the main element of spectral filtration. Here, we introduce a filter-optimization method, which utilizes an expression for the signal-to-noise ratio (SNR) as a function of (i) all noise components (dark, shot, and flicker), (ii) emission spectrum of the analyte, (iii) emission spectrum of the optical background, and (iv) transmittance spectrum of the emission filter. In essence, the noise components and the emission spectra are determined experimentally and substituted into the expression. This leaves a single variable-the transmittance spectrum of the filter-which is optimized numerically by maximizing SNR. Maximizing SNR provides an accurate way of filter optimization, while a previously used approach based on maximizing a signal-to-background ratio (SBR) is the approximation that can lead to much poorer LOD specifically in detection of fluorescently labeled biomolecules. The proposed filter-optimization method will be an indispensable tool for developing new and improving existing fluorescence-detection systems aiming at ultimately low LOD.

Mercury emissions during cofiring of sub-bituminous coal and biomass (chicken waste, wood, coffee residue, and tobacco stalk) in a laboratory-scale fluidized bed combustor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan Cao; Hongcang Zhou; Junjie Fan

Four types of biomass (chicken waste, wood pellets, coffee residue, and tobacco stalks) were cofired at 30 wt % with a U.S. sub-bituminous coal (Powder River Basin Coal) in a laboratory-scale fluidized bed combustor. A cyclone, followed by a quartz filter, was used for fly ash removal during tests. The temperatures of the cyclone and filter were controlled at 250 and 150{sup o}C, respectively. Mercury speciation and emissions during cofiring were investigated using a semicontinuous mercury monitor, which was certified using ASTM standard Ontario Hydra Method. Test results indicated mercury emissions were strongly correlative to the gaseous chlorine concentrations, butmore » not necessarily correlative to the chlorine contents in cofiring fuels. Mercury emissions could be reduced by 35% during firing of sub-bituminous coal using only a quartz filter. Cofiring high-chlorine fuel, such as chicken waste (Cl = 22340 wppm), could largely reduce mercury emissions by over 80%. When low-chlorine biomass, such as wood pellets (Cl = 132 wppm) and coffee residue (Cl = 134 wppm), is cofired, mercury emissions could only be reduced by about 50%. Cofiring tobacco stalks with higher chlorine content (Cl = 4237 wppm) did not significantly reduce mercury emissions. Gaseous speciated mercury in flue gas after a quartz filter indicated the occurrence of about 50% of total gaseous mercury to be the elemental mercury for cofiring chicken waste, but occurrence of above 90% of the elemental mercury for all other cases. Both the higher content of alkali metal oxides or alkali earth metal oxides in tested biomass and the occurrence of temperatures lower than 650{sup o}C in the upper part of the fluidized bed combustor seemed to be responsible for the reduction of gaseous chlorine and, consequently, limited mercury emissions reduction during cofiring. 36 refs., 3 figs. 1 tab.« less

30 CFR 72.503 - Determination of emissions; filter maintenance; definition of “introduced”.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Determination of emissions; filter maintenance; definition of âintroducedâ. 72.503 Section 72.503 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-Underground Areas of Underground Coal Mines § 72.503 Determination of emissions; filter maintenance...

30 CFR 72.503 - Determination of emissions; filter maintenance; definition of “introduced”.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Determination of emissions; filter maintenance; definition of âintroducedâ. 72.503 Section 72.503 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-Underground Areas of Underground Coal Mines § 72.503 Determination of emissions; filter maintenance...

30 CFR 72.503 - Determination of emissions; filter maintenance; definition of “introduced”.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Determination of emissions; filter maintenance; definition of âintroducedâ. 72.503 Section 72.503 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-Underground Areas of Underground Coal Mines § 72.503 Determination of emissions; filter maintenance...

30 CFR 72.503 - Determination of emissions; filter maintenance; definition of “introduced”.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Determination of emissions; filter maintenance; definition of âintroducedâ. 72.503 Section 72.503 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-Underground Areas of Underground Coal Mines § 72.503 Determination of emissions; filter maintenance...

30 CFR 72.503 - Determination of emissions; filter maintenance; definition of “introduced”.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Determination of emissions; filter maintenance; definition of âintroducedâ. 72.503 Section 72.503 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...-Underground Areas of Underground Coal Mines § 72.503 Determination of emissions; filter maintenance...

40 CFR 60.5250 - What definitions must I know?

Code of Federal Regulations, 2011 CFR

2011-07-01

... used for discharging combustion gases to avoid severe damage to the air pollution control device or..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by...). (2) A change in the air pollution control devices used to comply with the emission limits for the...

40 CFR 60.5250 - What definitions must I know?

Code of Federal Regulations, 2013 CFR

2013-07-01

... used for discharging combustion gases to avoid severe damage to the air pollution control device or..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by...). (2) A change in the air pollution control devices used to comply with the emission limits for the...

40 CFR 60.5250 - What definitions must I know?

Code of Federal Regulations, 2014 CFR

2014-07-01

... used for discharging combustion gases to avoid severe damage to the air pollution control device or..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by...). (2) A change in the air pollution control devices used to comply with the emission limits for the...

40 CFR 60.5250 - What definitions must I know?

Code of Federal Regulations, 2012 CFR

2012-07-01

... used for discharging combustion gases to avoid severe damage to the air pollution control device or..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by...). (2) A change in the air pollution control devices used to comply with the emission limits for the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, R.M.

Although use of reverse-air filters dominates in operating US utility power stations, pulse-jet designs seem to be getting the lion`s share of attention for new and retrofit plants. This article examines key technical advantages of reverse-air designs that are becoming lost in the current debate. Control of particulate emissions continues to be an area of growing concern for operators of coal-fired powerplants, especially as it relates to air toxics and fine particulates. That concern has led to greater scrutiny of the devices used to control those emissions. Regarding the fabric-filter option, reverse-air (RA) designs have operated reliably at large utilitymore » units, but now face a strong challenge from pulse-jet (PJ) designs--which are more popular with operators of independent-power-producer, waste-to-energy, and other small solid-fuel-fired units. Both RA and PJ designs can adequately meet the particulate emissions requirements for large coal-fired units when properly applied. The wholesale shift by electric utilities from RA to PJ fabric filters--at least in discussion if not actual projects--is apparent but may be short-sighted. The oft-stated reason--that RA fabric filters can only handle a face velocity one-half that of PJ, resulting in higher cost for the RA option--is too simplistic. The many design and operating characteristics that distinguish the two should be thoroughly reviewed before blanket acceptance of PJ technology. Some of the technical areas reviewed here are level of commercial design experience, bag life, pressure drop, bag replacement procedure, cleaning cycles, particle elutriation, submicron-particle floaters, residual-cake preservation, and particle re-entrainment.« less

Excitation-emission fluorimeter based on linear interference filters.

PubMed

Gouzman, Michael; Lifshitz, Nadia; Luryi, Serge; Semyonov, Oleg; Gavrilov, Dmitry; Kuzminskiy, Vyacheslav

2004-05-20

We describe the design, properties, and performance of an excitation-emission (EE) fluorimeter that enables spectral characterization of an object simultaneously with respect to both its excitation and its emission properties. Such devices require two wavelength-selecting elements, one in the optical path of the excitation broadband light to obtain tunable excitation and the other to analyze the resulting fluorescence. Existing EE instruments are usually implemented with two monochromators. The key feature of our EE fluorimeter is that it employs lightweight and compact linear interference filters (LIFs) as the wavelength-selection elements. The spectral tuning of both the excitation and the detection LIFs is achieved by their mechanical shift relative to each other by use of two computer-controlled linear step motors. The performance of the LIF-based EE fluorimeter is demonstrated with the fluorescent spectra of various dyes and their mixtures.

Data quality enhancement and knowledge discovery from relevant signals in acoustic emission

NASA Astrophysics Data System (ADS)

Mejia, Felipe; Shyu, Mei-Ling; Nanni, Antonio

2015-10-01

The increasing popularity of structural health monitoring has brought with it a growing need for automated data management and data analysis tools. Of great importance are filters that can systematically detect unwanted signals in acoustic emission datasets. This study presents a semi-supervised data mining scheme that detects data belonging to unfamiliar distributions. This type of outlier detection scheme is useful detecting the presence of new acoustic emission sources, given a training dataset of unwanted signals. In addition to classifying new observations (herein referred to as "outliers") within a dataset, the scheme generates a decision tree that classifies sub-clusters within the outlier context set. The obtained tree can be interpreted as a series of characterization rules for newly-observed data, and they can potentially describe the basic structure of different modes within the outlier distribution. The data mining scheme is first validated on a synthetic dataset, and an attempt is made to confirm the algorithms' ability to discriminate outlier acoustic emission sources from a controlled pencil-lead-break experiment. Finally, the scheme is applied to data from two fatigue crack-growth steel specimens, where it is shown that extracted rules can adequately describe crack-growth related acoustic emission sources while filtering out background "noise." Results show promising performance in filter generation, thereby allowing analysts to extract, characterize, and focus only on meaningful signals.

Effect of soil texture and chemical properties on laboratory-generated dust emissions from SW North America

NASA Astrophysics Data System (ADS)

Mockford, T.; Zobeck, T. M.; Lee, J. A.; Gill, T. E.; Dominguez, M. A.; Peinado, P.

2012-12-01

Understanding the controls of mineral dust emissions and their particle size distributions during wind-erosion events is critical as dust particles play a significant impact in shaping the earth's climate. It has been suggested that emission rates and particle size distributions are independent of soil chemistry and soil texture. In this study, 45 samples of wind-erodible surface soils from the Southern High Plains and Chihuahuan Desert regions of Texas, New Mexico, Colorado and Chihuahua were analyzed by the Lubbock Dust Generation, Analysis and Sampling System (LDGASS) and a Beckman-Coulter particle multisizer. The LDGASS created dust emissions in a controlled laboratory setting using a rotating arm which allows particle collisions. The emitted dust was transferred to a chamber where particulate matter concentration was recorded using a DataRam and MiniVol filter and dust particle size distribution was recorded using a GRIMM particle analyzer. Particle size analysis was also determined from samples deposited on the Mini-Vol filters using a Beckman-Coulter particle multisizer. Soil textures of source samples ranged from sands and sandy loams to clays and silts. Initial results suggest that total dust emissions increased with increasing soil clay and silt content and decreased with increasing sand content. Particle size distribution analysis showed a similar relationship; soils with high silt content produced the widest range of dust particle sizes and the smallest dust particles. Sand grains seem to produce the largest dust particles. Chemical control of dust emissions by calcium carbonate content will also be discussed.

Environmental Technology Verification Report and Statement for Baghouse Filtration Products, W. L. Gore & Associates, Inc. 5117 High Durability PPS Laminate Filtration Media (Tested March-April 2012)

EPA Science Inventory

Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

Low light CMOS contact imager with an integrated poly-acrylic emission filter for fluorescence detection.

PubMed

Dattner, Yonathan; Yadid-Pecht, Orly

2010-01-01

This study presents the fabrication of a low cost poly-acrylic acid (PAA) based emission filter integrated with a low light CMOS contact imager for fluorescence detection. The process involves the use of PAA as an adhesive for the emission filter. The poly-acrylic solution was chosen due its optical transparent properties, adhesive properties, miscibility with polar protic solvents and most importantly its bio-compatibility with a biological environment. The emission filter, also known as an absorption filter, involves dissolving an absorbing specimen in a polar protic solvent and mixing it with the PAA to uniformly bond the absorbing specimen and harden the filter. The PAA is optically transparent in solid form and therefore does not contribute to the absorbance of light in the visible spectrum. Many combinations of absorbing specimen and polar protic solvents can be derived, yielding different filter characteristics in different parts of the spectrum. We report a specific combination as a first example of implementation of our technology. The filter reported has excitation in the green spectrum and emission in the red spectrum, utilizing the increased quantum efficiency of the photo sensitive sensor array. The thickness of the filter (20 μm) was chosen by calculating the desired SNR using Beer-Lambert's law for liquids, Quantum Yield of the fluorophore and the Quantum Efficiency of the sensor array. The filters promising characteristics make it suitable for low light fluorescence detection. The filter was integrated with a fully functional low noise, low light CMOS contact imager and experimental results using fluorescence polystyrene micro-spheres are presented.

Performance of a pilot-scale biotrickling filter in controlling the volatile organic compound emissions in a furniture manufacturing facility.

PubMed

Martínez-Soria, Vicente; Gabaldón, Carmen; Penya-Roja, Josep M; Palau, Jordi; Alvarez-Hornos, F Javier; Sempere, Feliu; Soriano, Carlos

2009-08-01

A 0.75-m3 pilot-scale biotrickling filter was run for over 1 yr in a Spanish furniture company to evaluate its performance in the removal of volatile organic compounds (VOCs) contained in the emission of two different paint spray booths. The first one was an open front booth used to manually paint furniture, and the second focus was an automatically operated closed booth operated to paint pieces of furniture. In both cases, the VOC emissions were very irregular, with rapid and extreme fluctuations. The pilot plant was operated at an empty bed residence time (EBRT) ranging from 10 to 40 sec, and good removal efficiencies of VOCs were usually obtained. When a buffering activated carbon prefilter was installed, the system performance was improved considerably, so a much better compliance with legal constraints was reached. After different shutdowns in the factory, the period to recover the previous performance of the biotrickling reactor was minimal. A weekend dehydration strategy was developed and implemented to control the pressure drop associated with excessive biomass accumulation.

Laser based analysis using a passively Q-switched laser employing analysis electronics and a means for detecting atomic optical emission of the laser media

DOEpatents

Woodruff, Steven D.; Mcintyre, Dustin L.

2016-03-29

A device for Laser based Analysis using a Passively Q-Switched Laser comprising an optical pumping source optically connected to a laser media. The laser media and a Q-switch are positioned between and optically connected to a high reflectivity mirror (HR) and an output coupler (OC) along an optical axis. The output coupler (OC) is optically connected to the output lens along the optical axis. A means for detecting atomic optical emission comprises a filter and a light detector. The optical filter is optically connected to the laser media and the optical detector. A control system is connected to the optical detector and the analysis electronics. The analysis electronics are optically connected to the output lens. The detection of the large scale laser output production triggers the control system to initiate the precise timing and data collection from the detector and analysis.

Characterization of outdoor air particles as source of impurities in supply air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasanen, P.; Kalliokoski, P.; Tuomainen, A.

1997-12-31

Odor emission of supply air filters has proved to be a major source of stuffy odor of supply air. In this study, the odor emission characteristics of outdoor air particles and odor emissions of coarse prefilters and fine filters were studied. The outdoor air samples were collected by the aid of high volume impactor. Odor emissions of the size fractions, < 2.1 {micro}m , 2.1--10 {micro}m and >10 {micro}m were studied separately in laboratory with a trained olf panel: The odor emissions of the ventilation filters in real use were evaluated five times during the 14 month study period. Aftermore » the field evaluation the emissions of carbonyl compounds and other volatile organic compounds. The odor emissions of outdoor air particles were the highest during the heating season and lowest in the summer. The particles in the coarsest fraction had the most abundant emissions (1,200 olf/g) while the emissions from fine particles were lowest (100 olf/g). The odor emissions evaluated from the coarse and fine ventilation filters supported the finding that particles collected on coarse prefilter had the most abundant odor emission.« less

Aerosol emission monitoring in the production of silicon carbide nanoparticles by induction plasma synthesis

NASA Astrophysics Data System (ADS)

Thompson, Drew; Leparoux, Marc; Jaeggi, Christian; Buha, Jelena; Pui, David Y. H.; Wang, Jing

2013-12-01

In this study, the synthesis of silicon carbide (SiC) nanoparticles in a prototype inductively coupled thermal plasma reactor and other supporting processes, such as the handling of precursor material, the collection of nanoparticles, and the cleaning of equipment, were monitored for particle emissions and potential worker exposure. The purpose of this study was to evaluate the effectiveness of engineering controls and best practice guidelines developed for the production and handling of nanoparticles, identify processes which result in a nanoparticle release, characterize these releases, and suggest possible administrative or engineering controls which may eliminate or control the exposure source. No particle release was detected during the synthesis and collection of SiC nanoparticles and the cleaning of the reactor. This was attributed to most of these processes occurring in closed systems operated at slight underpressure. Other tasks occurring in more open spaces, such as the disconnection of a filter assembly from the reactor system and the use of compressed air for the cleaning of filters where synthesized SiC nanoparticles were collected, resulted in releases of submicrometer particles with a mode size of 170-180 nm. Observation of filter samples under scanning electron microscope confirmed that the particles were agglomerates of SiC nanoparticles.

Liquid crystal cells with built-in CdSe nanotubes for chromogenic smart emission devices.

PubMed

Lin, Tsung Ju; Chen, Chin-Chang; Cheng, Soofin; Chen, Yang Fang

2008-01-21

A simple and general approach for controlling optical anisotropy of nanostructured semiconductors is reported. Our design involves the fabrication of liquid crystal devices with built-in semiconductor nanotubes. Quite interestingly, it is found that semiconductor nanotubes can be well aligned along the orientation of liquid crystals molecules automatically, resulting in a very large emission anisotropy with the degree of polarization up to 72%. This intriguing result manifests a way to obtain well aligned semiconductor nanotubes and the emission anisotropy can be easily manipulated by an external bias. The ability to well control the emission anisotropy should open up new opportunities for nanostructured semiconductors, including optical filters, polarized light emitting diodes, flat panel displays, and many other chromogenic smart devices.

Does the New European Driving Cycle (NEDC) really fail to capture the NOX emissions of diesel cars in Europe?

PubMed

Degraeuwe, Bart; Weiss, Martin

2017-03-01

Tests with Portable Emissions Measurement Systems (PEMS) have demonstrated that diesel cars emit several times more NO X on the road than during certification on the New European Driving Cycle (NEDC). Policy makers and scientists have attributed the discrepancy to the unrealistically low dynamics and the narrow temperature range of NEDC testing. Although widely accepted, this assumption was never been put under scientific scrutiny. Here, we demonstrate that the narrow NEDC test conditions explain only a small part of the elevated on-road NO X emissions of diesel cars. For seven Euro 4-6 diesel cars, we filter from on-road driving those events that match the NEDC conditions in instantaneous speed, acceleration, CO 2 emissions, and ambient temperature. The resulting on-road NO X emissions exceed by 206% (median) those measured on the NEDC, whereas the NO X emissions of all unfiltered on-road measurements exceed the NEDC emissions by 266% (median). Moreover, when applying the same filtering of on-road data to two other driving cycles (WLTP and CADC), the resulting on-road NO X emissions exceed by only 13% (median) those measured over the respective cycles. This result demonstrates that our filtering method is accurate and robust. If neither the low dynamics nor the limited temperature range of NEDC testing can explain the elevated NO X emissions of diesel cars, emissions control strategies used during NEDC testing must be inactive or modulated on the road, even if vehicles are driven under certification-like conditions. This points to defeat strategies that warrant further investigations by type-approval authorities and, in turn, limitations in the enforcement of the European vehicle emissions legislation by EU Member States. We suggest applying our method as a simple yet effective tool to screen and select vehicles for in-depth analysis by the competent certification authorities. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

40 CFR 60.2265 - What definitions must I know?

Code of Federal Regulations, 2012 CFR

2012-07-01

... means an add-on air pollution control device used to capture particulate matter by filtering gas streams... in the air pollution control devices used to comply with the emission limits for the affected CISWI... definitions must I know? Terms used but not defined in this subpart are defined in the Clean Air Act and...

Emissions of Transport Refrigeration Units with CARB Diesel, Gas-to-Liquid Diesel, and Emissions Control Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnitt, R. A.; Chernich, D.; Burnitzki, M.

2010-05-01

A novel in situ method was used to measure emissions and fuel consumption of transport refrigeration units (TRUs). The test matrix included two fuels, two exhaust configurations, and two TRU engine operating speeds. Test fuels were California ultra low sulfur diesel and gas-to-liquid (GTL) diesel. Exhaust configurations were a stock muffler and a Thermo King pDPF diesel particulate filter. The TRU engine operating speeds were high and low, controlled by the TRU user interface. Results indicate that GTL diesel fuel reduces all regulated emissions at high and low engine speeds. Application of a Thermo King pDPF reduced regulated emissions, sometimesmore » almost entirely. The application of both GTL diesel and a Thermo King pDPF reduced regulated emissions at high engine speed, but showed an increase in oxides of nitrogen at low engine speed.« less

Dilution-based emissions sampling from stationary sources: Part 2--Gas-fired combustors compared with other fuel-fired systems.

PubMed

England, Glenn C; Watson, John G; Chow, Judith C; Zielinska, Barbara; Chang, M C Oliver; Loos, Karl R; Hidy, George M

2007-01-01

With the recent focus on fine particle matter (PM2.5), new, self-consistent data are needed to characterize emissions from combustion sources. Such data are necessary for health assessment and air quality modeling. To address this need, emissions data for gas-fired combustors are presented here, using dilution sampling as the reference. The dilution method allows for collection of emitted particles under conditions simulating cooling and dilution during entry from the stack into the air. The sampling and analysis of the collected particles in the presence of precursor gases, SO2 nitrogen oxide, volatile organic compound, and NH3 is discussed; the results include data from eight gas fired units, including a dual-fuel institutional boiler and a diesel engine powered electricity generator. These data are compared with results in the literature for heavy-duty diesel vehicles and stationary sources using coal or wood as fuels. The results show that the gas-fired combustors have very low PM2.5 mass emission rates in the range of approximately 10(-4) lb/million Btu (MMBTU) compared with the diesel backup generator with particle filter, with approximately 5 x 10(-3) lb/MMBTU. Even higher mass emission rates are found in coal-fired systems, with rates of approximately 0.07 lb/MMBTU for a bag-filter-controlled pilot unit burning eastern bituminous coal. The characterization of PM2.5 chemical composition from the gas-fired units indicates that much of the measured primary particle mass in PM2.5 samples is organic or elemental carbon and, to a much less extent, sulfate. Metal emissions are quite low compared with the diesel engines and the coal- or wood-fueled combustors. The metals found in the gas-fired combustor particles are low in concentration, similar in concentration to ambient particles. The interpretation of the particulate carbon emissions is complicated by the fact that an approximately equal amount of particulate carbon (mainly organic carbon) is found on the particle collector and a backup filter. It is likely that measurement artifacts, mostly adsorption of volatile organic compounds on quartz filters, are positively biasing "true" particulate carbon emission results.

Exposure to space radiation of high-performance infrared multilayer filters

NASA Technical Reports Server (NTRS)

Seeley, J. S.; Hawkins, G. J.; Hunneman, R.

1991-01-01

The University of Reading experiment exposed IR interference filters and crystal substrates on identical earth facing and leading-edge sites of the Long Duration Exposure Facility (LDEF). Filters mostly comprised multilayer coatings of lead telluride (PbTe)/II-IV on germanium (Ge) and other substrates: crystals comprised CdTe, MgF2, sapphire, quartz, silicon, and some softer materials. Identical control samples were maintained in the laboratory throughout the experiment. The filters were novel in their design, construction and manufacture, and categorized high-performance because of their ability to resolve emission spectra of the important atmospheric gases for various purposes in remote sensing. No significant changes were found in the spectra of the hard-coated filters or in the harder crystals (the softer materials were degraded to an extent). By virtue of this well-documented and long exposure in LDEF, the qualification of the filter type is significantly improved for its future requirements.

Engineering Filters for Reducing Spontaneous Emission in cQED

NASA Astrophysics Data System (ADS)

Bronn, Nicholas; Masluk, Nicholas; Srinivasan, Srikanth; Chow, Jerry; Abraham, David; Rothwell, Mary; Keefe, George; Gambetta, Jay; Steffen, Matthias; Lirakis, Chris

2014-03-01

Inserting a notch filter between a qubit and the external environment at the qubit frequency can significantly suppress spontaneous emission mediated by the cavity (``Purcell effect''). In order to realize this filtering in multi-qubit architectures, where space comes at a premium, we will present a filter with minimal space requirements. We acknowledge support from IARPA under contract W911NF-10-1-0324.

Application of microwave energy in the control of DPM, oxides of nitrogen and VOC emissions

NASA Astrophysics Data System (ADS)

Pallavkar, Sameer M.

The emissions of DPM (diesel particulate matter), NOx (oxides of nitrogen), and toxic VOCs (volatile organic compounds) from diesel engine exhaust gases and other sources such as chemical process industry and manufacturing industry have been a great environmental and health concern. Most control technologies for these emissions require elevated temperatures. The use of microwave energy as a source of heat energy, however, has not been fully explored. In this study, the microwave energy was used as the energy source in three separate emission control processes, namely, the regeneration of diesel particulate filter (DPF) for DPM control, the NOx reduction using a platinum catalyst, and the VOC destruction involving a ceramic based material. The study has demonstrated that microwave heating is an effective method in providing heat for the studied processes. The control efficiencies associated with the microwave-assisted processes have been observed to be high and acceptable. Further research, however, is required for the commercial use of these technologies.

Trace metal distribution and control in the pilot-scale bubbling fluidized bed combustor equipped with the pulse-jet fabric filter, limestone injection, and the humidification reactor.

PubMed

Kouvo, Petri

2003-04-01

This work focused on trace metal behavior and removal in a fabric filter or in a humidification reactor during the cofiring of sawdust and refuse-derived fuels (RDFs) in a pilot-scale bubbling fluidized bed (BFB) boiler. Trace metal emissions measurements before and after the fabric filter revealed that removal efficiency in the fabric filter was in the range of 80-100%, and that the European Union (EU) Directive on Incineration of Waste restrictions for trace metal emissions are easily achieved even if addition of RDFs substantially increases the concentration of trace metals in fuel blends. Limestone injection enhanced the removal of As and Se but had no noticeable effect on the removal of other trace metals. Extensive formation of HgCl2 and condensation on fly ash particles during sawdust plus 40% RDF cofiring resulted in a 92% Hg removal efficiency in the fabric filter. Limestone injection had no effect on the Hg removal in the fabric filter but decreased the Hg removal in a humidification reactor from 40 to 28%. Results of the bed material and fly ash analysis suggested capture of Cu, Pb, Mn, Ni, and Zn in the bed material but also suggested that these metals may be released from the bed if the fuel characteristics or process conditions are changed.

1.7  μm band narrow-linewidth tunable Raman fiber lasers pumped by spectrum-sliced amplified spontaneous emission.

PubMed

Zhang, Peng; Wu, Di; Du, Quanli; Li, Xiaoyan; Han, Kexuan; Zhang, Lizhong; Wang, Tianshu; Jiang, Huilin

2017-12-10

A 1.7 μm band tunable narrow-linewidth Raman fiber laser based on spectrally sliced amplified spontaneous emission (SS-ASE) and multiple filter structures is proposed and experimentally demonstrated. In this scheme, an SS-ASE source is employed as a pump source in order to avoid stimulated Brillouin scattering. The ring configuration includes a 500 m long high nonlinear optical fiber and a 10 km long dispersion shifted fiber as the gain medium. A segment of un-pumped polarization-maintaining erbium-doped fiber is used to modify the shape of the spectrum. Furthermore, a nonlinear polarization rotation scheme is applied as the wavelength selector to generate lasers. A high-finesse ring filter and a ring filter are used to narrow the linewidth of the laser, respectively. We demonstrate tuning capabilities of a single laser over 28 nm between 1652 nm and 1680 nm by adjusting the polarization controller (PC) and tunable filter. The tunable laser has a 0.023 nm effective linewidth with the high-finesse ring filter. The stable multi-wavelength laser operation of up to four wavelengths can be obtained by adjusting the PC carefully when the pump power increases.

Optical emission line monitor with background observation and cancellation

DOEpatents

Goff, D.R.; Notestein, J.E.

1985-01-04

A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interfering blackbody radiation by greater than 20 dB.

Optical emission line monitor with background observation and cancellation

DOEpatents

Goff, David R.; Notestein, John E.

1986-01-01

A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.

Hyperspectral Infrared Imaging of Flames Using a Spectrally Scanning Fabry-Perot Filter

NASA Technical Reports Server (NTRS)

Rawlins, W. T.; Lawrence, W. G.; Marinelli, W. J.; Allen, M. G.; Piltch, N. (Technical Monitor)

2001-01-01

The temperatures and compositions of gases in and around flames can be diagnosed using infrared emission spectroscopy to observe molecular band shapes and intensities. We have combined this approach with a low-order scanning Fabry-Perot filter and an infrared camera to obtain spectrally scanned infrared emission images of a laboratory flame and exhaust plume from 3.7 to 5.0 micrometers, at a spectral resolution of 0.043 micrometers, and a spatial resolution of 1 mm. The scanning filter or AIRIS (Adaptive Infrared Imaging Spectroradiometer) is a Fabry-Perot etalon operating in low order (mirror spacing = wavelength) such that the central spot, containing a monochromatic image of the scene, is viewed by the detector array. The detection system is a 128 x 128 liquid-nitrogen-cooled InSb focal plane array. The field of view is controlled by a 50 mm focal length multielement lens and an V4.8 aperture, resulting in an image 6.4 x 6.4 cm in extent at the flame and a depth of field of approximately 4 cm. Hyperspectral images above a laboratory CH4/air flame show primarily the strong emission from CO2 at 4.3 micrometers, and weaker emissions from CO and H2O. We discuss techniques to analyze the spectra, and plans to use this instrument in microgravity flame spread experiments.

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control

PubMed Central

Gabriel, David; Deshusses, Marc A.

2003-01-01

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8–20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control. PMID:12740445

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control.

PubMed

Gabriel, David; Deshusses, Marc A

2003-05-27

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8-20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control.

Field Testing Pulsed Power Inverters in Welding Operations to Control Heavy Metal Emissions

DTIC Science & Technology

2009-12-01

diameter glass fiber media material. After gases passed through the CI, they entered four glass impingers, in series, that were chilled in an ice...Vanadium 0.05 0.05 0.01 (as V2O5 ) 0.00038 - Zinc 2 (as ZnO) 5 (as ZnO) 5 (as ZnO) 0.058 0.166 1...the impactor’s requirement for a specific optimum volumetric flow range. Filter media for each stage of the cascade impactor ( glass fiber filter

76 FR 74708 - National Emission Standards for Hazardous Air Pollutants for Source Categories

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

... as follows: Bag leak detection system means a monitoring device for a fabric filter that identifies an increase in particulate matter emissions resulting from a broken filter bag or other malfunction... thermoset a binder on the mineral wool fiber used to make bonded products. Fabric filter means an air...

47 CFR 90.210 - Emission masks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... sweeps must be measured to insure that the emission profile is developed. If video filtering is used, its... profile is developed. If video filtering is used, its bandwidth must not be less than the instrument... with 1 MHz of the edge of the authorized subband. The video filter bandwidth shall not be less than the...

47 CFR 90.210 - Emission masks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... sweeps must be measured to insure that the emission profile is developed. If video filtering is used, its... profile is developed. If video filtering is used, its bandwidth must not be less than the instrument... with 1 MHz of the edge of the authorized subband. The video filter bandwidth shall not be less than the...

Waste separation: Does it influence municipal waste combustor emissions?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandler, A.J.; Rigo, H.G.

1996-09-01

It has been suggested that MSW incinerator emissions show significant variations because of the heterogeneous nature of the waste fed to the furnace. This argument has even been used to propose banning certain materials from incinerators. However, data previously reported by the authors suggests that a large portion of the trace metals come from natural sources. Furthermore, full scale incinerator spiking experiments suggest that certain forms of trace metals have minimal effects on stack emissions. Similar studies with chlorinated plastics have failed to identify a significant effect on incinerator dioxin emissions. The implication of segregating the lawn and garden wastemore » and other fines from the furnace feed is explored using data from a 400 tpd mass burn facility equipped with a conditioning tower, dry reactor and fabric filter air pollution control system (APCS) preceded by an NRT separation system. The stack emissions have been tested periodically since commissioning to characterize emissions for various seasons using both processed fuel and raw MSW. Front end processing to remove selected portions of the waste stream based upon size or physical properties, i.e. fines, grass, or ferrous materials, did not result in a statistically significant difference in stack emissions. System operating regime, and in particular those that effect the effective air to cloth ratio in the fabric filter, appear to be the principal influence on emission levels.« less

Demonstration of a Single-Crystal Reflector-Filter for Enhancing Slow Neutron Beams

DOE PAGES

Muhrer, Guenter; Schönfeldt, Troels; Iverson, Erik B.; ...

2016-06-14

The cold polycrystalline beryllium reflector-filter concept has been used to enhance the cold neutron emission of cryogenic hydrogen moderators, while suppressing the intermediate wavelength and fast neutron emission at the same time. While suppressing the fast neutron emission is often desired, the suppression of intermediate wavelength neutrons is often unwelcome. It has been hypothesized that replacing the polycrystalline reflector-filter concept with a single-crystal reflector-filter concept would overcome the suppression of intermediate wavelength neutrons and thereby extend the usability of the reflector-filter concept to shorter but still important wavelengths. In this paper we present the first experimental data on a single-crystalmore » reflector-filter and compare experimental results with hypothesized performance. We find that a single-crystal reflector-filter retains the long-wavelength benefit of the polycrystalline reflector-filter, without suffering the same loss of important intermediate wavelength neutrons. Ultimately, this finding extends the applicability of the reflector-filter concept to intermediate wavelengths, and furthermore indicates that the reflector-filter benefits arise from its interaction with fast (background) neutrons, not with intermediate wavelength neutrons of potential interest in many types of neutron scattering.« less

Qualitative Analysis of E-Liquid Emissions as a Function of Flavor Additives Using Two Aerosol Capture Methods.

PubMed

Eddingsaas, Nathan; Pagano, Todd; Cummings, Cody; Rahman, Irfan; Robinson, Risa; Hensel, Edward

2018-02-13

This work investigates emissions sampling methods employed for qualitative identification of compounds in e-liquids and their resultant aerosols to assess what capture methods may be sufficient to identify harmful and potentially harmful constituents present. Three popular e-liquid flavors (cinnamon, mango, vanilla) were analyzed using qualitative gas chromatography-mass spectrometry (GC-MS) in the un-puffed state. Each liquid was also machine-puffed under realistic-use flow rate conditions and emissions were captured using two techniques: filter pads and methanol impingers. GC-MS analysis was conducted on the emissions captured using both techniques from all three e-liquids. The e-liquid GC-MS analysis resulted in positive identification of 13 compounds from the cinnamon flavor e-liquid, 31 from mango, and 19 from vanilla, including a number of compounds observed in all e-liquid experiments. Nineteen compounds were observed in emissions which were not present in the un-puffed e-liquid. Qualitative GC-MS analysis of the emissions samples identify compounds observed in all three samples: e-liquid, impinge, and filter pads, and each subset thereof. A limited number of compounds were observed in emissions captured with impingers, but were not observed in emissions captured using filter pads; a larger number of compounds were observed on emissions collected from the filter pads, but not those captured with impingers. It is demonstrated that sampling methods have different sampling efficiencies and some compounds might be missed using only one method. It is recommended to investigate filter pads, impingers, thermal desorption tubes, and solvent extraction resins to establish robust sampling methods for emissions testing of e-cigarette emissions.

Qualitative Analysis of E-Liquid Emissions as a Function of Flavor Additives Using Two Aerosol Capture Methods

PubMed Central

Eddingsaas, Nathan; Pagano, Todd; Cummings, Cody; Rahman, Irfan; Robinson, Risa

2018-01-01

This work investigates emissions sampling methods employed for qualitative identification of compounds in e-liquids and their resultant aerosols to assess what capture methods may be sufficient to identify harmful and potentially harmful constituents present. Three popular e-liquid flavors (cinnamon, mango, vanilla) were analyzed using qualitative gas chromatography-mass spectrometry (GC-MS) in the un-puffed state. Each liquid was also machine-puffed under realistic-use flow rate conditions and emissions were captured using two techniques: filter pads and methanol impingers. GC-MS analysis was conducted on the emissions captured using both techniques from all three e-liquids. The e-liquid GC-MS analysis resulted in positive identification of 13 compounds from the cinnamon flavor e-liquid, 31 from mango, and 19 from vanilla, including a number of compounds observed in all e-liquid experiments. Nineteen compounds were observed in emissions which were not present in the un-puffed e-liquid. Qualitative GC-MS analysis of the emissions samples identify compounds observed in all three samples: e-liquid, impinge, and filter pads, and each subset thereof. A limited number of compounds were observed in emissions captured with impingers, but were not observed in emissions captured using filter pads; a larger number of compounds were observed on emissions collected from the filter pads, but not those captured with impingers. It is demonstrated that sampling methods have different sampling efficiencies and some compounds might be missed using only one method. It is recommended to investigate filter pads, impingers, thermal desorption tubes, and solvent extraction resins to establish robust sampling methods for emissions testing of e-cigarette emissions. PMID:29438289

Radio Frequency Sensing of Particulate Matter Accumulation on a Gasoline Particulate Filter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, James; Prikhodko, Vitaly Y.; Sappok, Alex

Filter Sensing Technology’s radio frequency (RF) sensor for particulate filter on-board diagnostics (OBD) was studied on a lean gasoline engine at the National Transportation Research Center (NTRC) at Oak Ridge National Laboratory (ORNL). The response of the RF sensor to particulate matter (PM) or “soot” accumulation on the gasoline particulate filter (GPF) installed in the engine exhaust was evaluated. In addition, end plugs of the GPF were purposely removed, and subsequent changes to the RF sensor measured soot loading on the GPF were characterized. Results from the study showed that the RF sensor can accurately measure soot accumulation on amore » GPF; furthermore, the predicted decreased soot accumulation due to plug removal was detected by the RF sensor. Overall, the studies were short and preliminary in nature; however, clearly, the RF sensor demonstrated the capability of measuring GPF soot loading at a level suitable for use in lean gasoline engine emission control OBD and control.« less

Aerial sampling of emissions from biomass pile burns in ...

EPA Pesticide Factsheets

Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determined the emissions from open burning of forest slash wood, with and without plastic sheeting. The foresters advocate the use of plastic to keep the slash wood dry and aid in the controlled combustion of the slash to reduce fuel loading. Concerns about the emissions from the burning plastic prompted this work which conducted an extensive characterization of dry, wet, and dry with plastic slash pile emissions.

A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system.

PubMed

Sun, Kangfeng; Ji, Fenzhu; Yan, Xiaoyu; Jiang, Kai; Yang, Shichun

2018-01-01

As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small.

A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system

PubMed Central

Ji, Fenzhu; Yan, Xiaoyu; Jiang, Kai

2018-01-01

As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small. PMID:29408924

Cigarette Design Features: Effects on Emission Levels, User Perception, and Behavior.

PubMed

Talhout, Reinskje; Richter, Patricia A; Stepanov, Irina; Watson, Christina V; Watson, Clifford H

2018-01-01

This paper describes the effects of non-tobacco, physical cigarette design features on smoke emissions, product appeal, and smoking behaviors - 3 factors that determine smoker's exposure and related health risks. We reviewed available evidence for the impact of filter ventilation, new filter types, and cigarettes dimensions on toxic emissions, smoker's perceptions, and behavior. For evidence sources we used scientific literature and websites providing product characteristics and marketing information. Whereas filter ventilation results in lower machine-generated emissions, it also leads to perceptions of lighter taste and relative safety in smokers who can unwittingly employ more intense smoking behavior to obtain the desired amount of nicotine and sensory appeal. Filter additives that modify smoke emissions can also modify sensory cues, resulting in changes in smoking behavior. Flavor capsules increase the cigarette's appeal and novelty, and lead to misperceptions of reduced harm. Slim cigarettes have lower yields of some smoke emissions, but smoking behavior can be more intense than with standard cigarettes. Physical design features significantly impact machine-measured emission yields in cigarette smoke, product appeal, smoking behaviors, and exposures in smokers. The influence of current and emerging design features is important in understanding the effectiveness of regulatory actions to reduce smoking-related harm.

Capturing PM2.5 Emissions from 3D Printing via Nanofiber-based Air Filter.

PubMed

Rao, Chengchen; Gu, Fu; Zhao, Peng; Sharmin, Nusrat; Gu, Haibing; Fu, Jianzhong

2017-09-04

This study investigated the feasibility of using polycaprolactone (PCL) nanofiber-based air filters to capture PM2.5 particles emitted from fused deposition modeling (FDM) 3D printing. Generation and aggregation of emitted particles were investigated under different testing environments. The results show that: (1) the PCL nanofiber membranes are capable of capturing particle emissions from 3D printing, (2) relative humidity plays a signification role in aggregation of the captured particles, (3) generation and aggregation of particles from 3D printing can be divided into four stages: the PM2.5 concentration and particles size increase slowly (first stage), small particles are continuously generated and their concentration increases rapidly (second stage), small particles aggregate into more large particles and the growth of concentration slows down (third stage), the PM2.5 concentration and particle aggregation sizes increase rapidly (fourth stage), and (4) the ultrafine particles denoted as "building unit" act as the fundamentals of the aggregated particles. This work has tremendous implications in providing measures for controlling the particle emissions from 3D printing, which would facilitate the extensive application of 3D printing. In addition, this study provides a potential application scenario for nanofiber-based air filters other than laboratory theoretical investigation.

Particle emissions from diesel passenger cars equipped with a particle trap in comparison to other technologies.

PubMed

Mohr, Martin; Forss, Anna-Maria; Lehmann, Urs

2006-04-01

Tail pipe particle emissions of passenger cars, with different engine and aftertreatment technologies, were determined with special focus on diesel engines equipped with a particle filter. The particle number measurements were performed, during transient tests, using a condensation particle counter. The measurement procedure complied with the draft Swiss ordinance, which is based on the findings of the UN/ECE particulate measurement program. In addition, particle mass emissions were measured by the legislated and a modified filter method. The results demonstrate the high efficiency of diesel particle filters (DPFs) in curtailing nonvolatile particle emissions over the entire size range. Higher emissions were observed during short periods of DPF regeneration and immediately afterward, when a soot cake has not yet formed on the filter surface. The gasoline vehicles exhibited higher emissions than the DPF equipped diesel vehicles but with a large variation depending on the technology and driving conditions. Although particle measurements were carried out during DPF regeneration, it was impossible to quantify their contribution to the overall emissions, due to the wide variation in intensity and frequency of regeneration. The numbers counting method demonstrated its clear superiority in sensitivity to the mass measurement. The results strongly suggest the application of the particle number counting to quantify future low tailpipe emissions.

Extracting spatial information from large aperture exposures of diffuse sources

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Moos, H. W.

1981-01-01

The spatial properties of large aperture exposures of diffuse emission can be used both to investigate spatial variations in the emission and to filter out camera noise in exposures of weak emission sources. Spatial imaging can be accomplished both parallel and perpendicular to dispersion with a resolution of 5-6 arc sec, and a narrow median filter running perpendicular to dispersion across a diffuse image selectively filters out point source features, such as reseaux marks and fast particle hits. Spatial information derived from observations of solar system objects is presented.

Probing the End of the IMF in NGC 2024 with NIRCam on JWST: Assessing the Impact of Nebular Emission in Galactic Star Forming Regions

NASA Astrophysics Data System (ADS)

Suri, Veenu; Meyer, Michael; Greenbaum, Alexandra Z.; Bell, Cameron; Beichman, Charles; Gordon, Karl D.; Greene, Thomas P.; Hodapp, K.; Horner, Scott; Johnstone, Doug; Leisenring, Jarron; Manara, Carlos; Mann, Rita; Misselt, K.; Raileanu, Roberta; Rieke, Marcia; Roellig, Thomas

2018-01-01

We describe observations of the embedded young cluster associated with the HII region NGC 2024 planned as part of the guaranteed time observing program for the James Webb Space Telescope with the NIRCam (Near Infrared Camera) instrument. Our goal is to obtain a census of the cluster down to 2 Jupiter masses, viewed through 10-20 magnitudes of extinction, using multi-band filter photometry, both broadband filters and intermediate band filters that are expected to be sensitive to temperature and surface gravity. The cluster contains several bright point sources as well as extended emission due to reflected light, thermal emission from warm dust, as well as nebular line emission. We first developed techniques to better understand which point sources would saturate in our target fields when viewed through several JWST NIRCam filters. Using images of the field with the WISE satellite in filters W1 and W2, as well as 2MASS (J and H) bands, we devised an algorithm that takes the K-band magnitudes of point sources in the field, and the known saturation limits of several NIRCam filters to estimate the impact of the extended emission on survey sensitivity. We provide an overview of our anticipated results, detecting the low mass end of the IMF as well as planetary mass objects likely liberated through dynamical interactions.

Effectiveness of in-room air filtration and dilution ventilation for tuberculosis infection control.

PubMed

Miller-Leiden, S; Lobascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

Effectiveness of In-Room Air Filtration and Dilution Ventilation for Tuberculosis Infection Control.

PubMed

Miller-Leiden, S; Lohascio, C; Nazaroff, W W; Macher, J M

1996-09-01

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.

Effects of Particle Filters and Selective Catalytic Reduction on In-Use Heavy-Duty Diesel Truck Emissions

NASA Astrophysics Data System (ADS)

Preble, C.; Cados, T.; Harley, R.; Kirchstetter, T.

2016-12-01

Heavy-duty diesel trucks (HDDT) are a major source of nitrogen oxides (NOx) and black carbon (BC) in urban environments, contributing to persistent ozone and particulate matter air quality problems. Diesel particle filters (DPFs) and selective catalytic reduction (SCR) systems that target PM and NOx emissions, respectively, have recently become standard equipment on new HDDT. DPFs can also be installed on older engines as a retrofit device. Previous work has shown that DPF and SCR systems can reduce NOx and BC emissions by up to 70% and 90%, respectively, compared to modern trucks without these after-treatment controls (Preble et al., ES&T 2015). DPFs can have the undesirable side-effect of increasing ultrafine particle (UFP) and nitrogen dioxide (NO2) emissions. While SCR systems can partially mitigate DPF-related NO2 increases, these systems can emit nitrous oxide (N2O), a potent greenhouse gas. We report new results from a study of HDDT emissions conducted in fall 2015 at the Port of Oakland and Caldecott Tunnel in California's San Francisco Bay Area. We report pollutant emission factors (g kg-1) for emitted NOx, NO2, BC, PM2.5, UFP, and N2O on a truck-by-truck basis. Using a roadside license plate recognition system, we categorize each truck by its engine model year and installed after-treatment controls. From this, we develop emissions profiles for trucks with and without DPF and SCR. We evaluate the effectiveness of these devices as a function of their age to determine whether degradation is an issue. We also compare the emission profiles of trucks traveling at low speeds along a level, arterial road en route to the port and at high speeds up a 4% grade highway approaching the tunnel. Given the climate impacts of BC and N2O, we also examine the global warming potential of emissions from trucks with and without DPF and SCR.

Assessment of potential concerns associated with the use of cement kiln baghouse dust in FDOT concrete mixes.

DOT National Transportation Integrated Search

2013-08-01

As a means of controlling mercury (Hg) stack emissions at cement kiln operations, some facilities have proposed or have instituted a practice known as dust shuttling, where baghouse filter dust (BFD) is routed to be blended with the final cement prod...

A LOW COST CATALYTIC FILTER FOR SIMULTANEOUS VOC AND PARTICULATE REMOVAL - PHASE II

EPA Science Inventory

Emissions of VOC's are subject to control by the EPA both because VOC's are regarded as ozone precursors and because many specific VOC's are hazardous air pollutants (HAP's) under the Clean Air Act Amendments. A number of industries generate offgases with both fine particul...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, TEST REPORT OF MOBILE SOURCE EMISSION CONTROL DEVICES: MITSUI ENGINEERING & SHIPBUILDING DIESEL PARTICULATE FILTER

EPA Science Inventory

EPA‘s Environmental Technology Verification program is designed to further environmental protection by accelerating the acceptance and use of improved and cost effective technologies. This is done by providing high-quality, peer reviewed data on technology performance to those in...

Laboratory validation of four black carbon measurement methods for the determination of non-volatile particulate matter (PM) mass emissions . . .

EPA Science Inventory

A laboratory-scale experimental program was designed to standardize each of four black carbon measurement methods, provide appropriate quality assurance/control procedures for these techniques, and compare measurements made by these methods to a NIST traceable standard (filter gr...

Real-time alkali monitoring system

DOEpatents

Goff, David R.; Romanosky, Robert R.; Hensel, Peter

1990-01-01

A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium emission line, may be detected in the presence of interfering background radiation. A combustion flame is fed by a diverted portion of a process stream and the common end of a bifurcated or quadfurcated fiber optic light guide is adapted to collect light from the flame. The light is guided through the branches of the fiber optic cable to bandpass filters, one of which is adapted to each of the branches of the fiber optic light guide. The bandpass filters are centered at wavelengths corresponding to the emission lines to be detected and two separate filters are required for each species being detected. The first filter has a bandwidth of about 3 nms and the second filter has a bandwidth of about 10 nms. Light detectors are located to view the light passing through the bandpass filters and amplifiers are connected to receive signals from the light detectors. The amplifier corresponding to the bandpass filter having the narrower bandwidth is preset to scale the signal by a factor equal to the ratio of the wide and narrow bandwidths of the bandpass filters. This scaling produces a scaled signal from which the difference between the scaled signal on the other signal can be calculated to produce a signal having an amplitude directly proportional to the concentration of the species of interest and independent of background radiation.

Coronal Loop Temperatures Obtained with Hinode XRT: A Toothpaste-Tube Analogy

NASA Astrophysics Data System (ADS)

Schmelz, J. T.; Saar, S. H.; Weber, M. A.; Deluca, E. E.; Golub, L.

2009-12-01

Multi-filter data observed by the Hinode X-Ray Telescope on 10 and 2007 July 13 were used to investigate the thermal properties of coronal loops. At several positions along the loops, differential emission measure analysis revealed a strong peak at log T = 6.1 (which would predict the presence of a TRACE loop) and a much weaker hot component (which we speculated might be a nanoflare signature). TRACE observations, however, did not reveal the predicted loop, so we were forced to re-examine our assumptions. Good differential emission measure results require high- and low-temperature constraints, but our data sets did not contain images from the thinnest and thickest filters, which would be most likely to provide these constraints. Since differential emission measure programs aim to match observed intensities and get low values of χ2, they may place emission measure in high- and low-temperature bins where it does not belong. We draw an analogy to squeezing the toothpaste tube in the middle. Our analysis was repeated for a loop observed on 2007 May 13 when the instrument acquired data in 11 filters and filter combinations, including both the thinnest and thickest filters. These results show that the loop is multi-thermal, with significant emission measure in the range 6.0 < log T < 6.5.

Improving optical performance of GaN nanowires grown by selective area growth homoepitaxy: Influence of substrate and nanowire dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aseev, P., E-mail: pavel.aseev@isom.upm.es, E-mail: gacevic@isom.upm.es; Gačević, Ž., E-mail: pavel.aseev@isom.upm.es, E-mail: gacevic@isom.upm.es; Calleja, E.

2016-06-20

Series of GaN nanowires (NW) with controlled diameters (160–500 nm) and heights (420–1100 nm) were homoepitaxially grown on three different templates: GaN/Si(111), GaN/AlN/Si(111), and GaN/sapphire(0001). Transmission electron microscopy reveals a strong influence of the NW diameter on dislocation filtering effect, whereas photoluminescence measurements further relate this effect to the GaN NWs near-bandgap emission efficiency. Although the templates' quality has some effects on the GaN NWs optical and structural properties, the NW diameter reduction drives the dislocation filtering effect to the point where a poor GaN template quality becomes negligible. Thus, by a proper optimization of the homoepitaxial GaN NWs growth, the propagationmore » of dislocations into the NWs can be greatly prevented, leading to an exceptional crystal quality and a total dominance of the near-bandgap emission over sub-bandgap, defect-related lines, such as basal stacking faults and so called unknown exciton (UX) emission. In addition, a correlation between the presence of polarity inversion domain boundaries and the UX emission lines around 3.45 eV is established.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Deanna Lynn; Coleman, Matthew A; Lane, Stephen M

A hand-held portable microarray reader for biodetection includes a microarray reader engineered to be small enough for portable applications. The invention includes a high-powered light-emitting diode that emits excitation light, an excitation filter positioned to receive the excitation light, a slide, a slide holder assembly for positioning the slide to receive the excitation light from the excitation filter, an emission filter positioned to receive the excitation light from the slide, a lens positioned to receive the excitation light from the emission filter, and a CCD camera positioned to receive the excitation light from the lens.

On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sappok, Alex; Ragaller, Paul; Herman, Andrew

The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directlymore » monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.« less

Particulate emissions calculations from fall tillage operations using point and remote sensors.

PubMed

Moore, Kori D; Wojcik, Michael D; Martin, Randal S; Marchant, Christian C; Bingham, Gail E; Pfeiffer, Richard L; Prueger, John H; Hatfield, Jerry L

2013-07-01

Soil preparation for agricultural crops produces aerosols that may significantly contribute to seasonal atmospheric particulate matter (PM). Efforts to reduce PM emissions from tillage through a variety of conservation management practices (CMPs) have been made, but the reductions from many of these practices have not been measured in the field. A study was conducted in California's San Joaquin Valley to quantify emissions reductions from fall tillage CMP. Emissions were measured from conventional tillage methods and from a "combined operations" CMP, which combines several implements to reduce tractor passes. Measurements were made of soil moisture, bulk density, meteorological profiles, filter-based total suspended PM (TSP), concentrations of PM with an equivalent aerodynamic diameter ≤10 μm (PM) and PM with an equivalent aerodynamic diameter ≤2.5 μm (PM), and aerosol size distribution. A mass-calibrated, scanning, three-wavelength light detection and ranging (LIDAR) procedure estimated PM through a series of algorithms. Emissions were calculated via inverse modeling with mass concentration measurements and applying a mass balance to LIDAR data. Inverse modeling emission estimates were higher, often with statistically significant differences. Derived PM emissions for conventional operations generally agree with literature values. Sampling irregularities with a few filter-based samples prevented calculation of a complete set of emissions through inverse modeling; however, the LIDAR-based emissions dataset was complete. The CMP control effectiveness was calculated based on LIDAR-derived emissions to be 29 ± 2%, 60 ± 1%, and 25 ± 1% for PM, PM, and TSP size fractions, respectively. Implementation of this CMP provides an effective method for the reduction of PM emissions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

[Restoration filtering based on projection power spectrum for single-photon emission computed tomography].

PubMed

Kubo, N

1995-04-01

To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images.

Io's Sodium Cloud (Clear Filter)

NASA Technical Reports Server (NTRS)

1997-01-01

This image of Jupiter's moon Io and its surrounding sky is shown in false color. It was taken at 5 hours 30 minutes Universal Time on Nov. 9, 1996 by the solid state imaging (CCD) system aboard NASA's Galileo spacecraft, using a clear filter whose wavelength range was approximately 400 to 1100 nanometers. This picture differs in two main ways from the green-yellow filter image of the same scene which was released yesterday.

First, the sky around Io is brighter, partly because the wider wavelength range of the clear filter lets in more scattered light from Io's illuminated crescent and from Prometheus' sunlit plume. Nonetheless, the overall sky brightness in this frame is comparable to that seen through the green-yellow filter, indicating that even here much of the diffuse sky emission is coming from the wavelength range of the green-yellow filter (i.e., from Io's Sodium Cloud).

The second major difference is that a quite large roundish spot has appeared in Io's southern hemisphere. This spot -- which has been colored red -- corresponds to thermal emission from the volcano Pele. The green-yellow filter image bears a much smaller trace of this emission because the clear filter is far more sensitive to those relatively long wavelengths where thermal emission is strongest.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

ENVIRONMENTAL TECHNOLOGY VERIFICATION: TEST REPORT OF MOBILE SOURCE EMISSION CONTROL DEVICES--PUREM NORTH AMERICA LLC, PMF GREENTEC 1004205.00.0 DIESEL PARTICULATE FILTER

EPA Science Inventory

The U.S. EPA has created the Environmental Technology Verification (ETV) program to provide high quality, peer reviewed data on technology performance to those involved in the design, distribution, financing, permitting, purchase, and use of environmental technologies. The Air Po...

40 CFR 63.1459 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... device that collects particulate matter by filtering the gas stream through bags. A baghouse is also... converter bath. Capture system means the collection of components used to capture gases and fumes released from one or more emission points, and to convey the captured gases and fumes to a control device. A...

40 CFR 63.11567 - Who implements and enforces this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

...). 2. A high-efficiency air filter or fiber bed filter a. Inlet gas temperature b, andb. Pressure drop...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt...

Method and apparatus for reducing cold-phase emissions by utilizing oxygen-enriched intake air

DOEpatents

Poola, Ramesh B.; Sekar, Ramanujam R.; Stork, Kevin C.

1997-01-01

An oxygen-enriched air intake control system for an internal combustion engine includes air directing apparatus to control the air flow into the intake of the engine. During normal operation of the engine, ambient air flowing from an air filter of the engine flows through the air directing apparatus into the intake of the engine. In order to decrease the amount of carbon monoxide (CO) and hydrocarbon (HC) emissions that tend to be produced by the engine during a short period of time after the engine is started, the air directing apparatus diverts for a short period of time following the start up of the engine at least a portion of the ambient air from the air filter through a secondary path. The secondary path includes a selectively permeable membrane through which the diverted portion of the ambient air flows. The selectively permeable membrane separates nitrogen and oxygen from the diverted air so that oxygen enriched air containing from about 23% to 25% oxygen by volume is supplied to the intake of the engine.

Tilting-filter measurements in dayglow rocket photometry.

PubMed

Schaeffer, R C; Fastie, W G

1972-10-01

A rocket-borne photometer containing two tilting-filter channels for the measurement of the [OI] lambdalambda6300-A and 5577A emission lines in the day airglow is described. The results of one flight substantiate the employment of tilting filters to determine accurate corrections for background continuum and provide reliable height profiles of emission intensity down to approximately 90 km. Discussions on the calibration of the instrument and its baffling against sunlight are also presented.

Optimal optical filters of fluorescence excitation and emission for poultry fecal detection

USDA-ARS?s Scientific Manuscript database

Purpose: An analytic method to design excitation and emission filters of a multispectral fluorescence imaging system is proposed and was demonstrated in an application to poultry fecal inspection. Methods: A mathematical model of a multispectral imaging system is proposed and its system parameters, ...

The spatial extent of polycyclic aromatic hydrocarbons emission in the Herbig star HD 179218

NASA Astrophysics Data System (ADS)

Taha, A. S.; Labadie, L.; Pantin, E.; Matter, A.; Alvarez, C.; Esquej, P.; Grellmann, R.; Rebolo, R.; Telesco, C.; Wolf, S.

2018-04-01

Aim. We investigate, in the mid-infrared, the spatial properties of the polycyclic aromatic hydrocarbons (PAHs) emission in the disk of HD 179218, an intermediate-mass Herbig star at 300 pc. Methods: We obtained mid-infrared images in the PAH-1, PAH-2 and Si-6 filters centered at 8.6, 11.3, and 12.5 μm, and N-band low-resolution spectra using CanariCam on the 10-m Gran Telescopio Canarias (GTC). We compared the point spread function (PSF) profiles measured in the PAH filters to the profile derived in the Si-6 filter, where the thermal continuum emission dominates. We performed radiative transfer modeling of the spectral energy distribution (SED) and produced synthetic images in the three filters to investigate different spatial scenarios. Results: Our data show that the disk emission is spatially resolved in the PAH-1 and PAH-2 filters, while unresolved in the Si-6 filter. Thanks to very good observing conditions, an average full width at half maximum (FWHM) of 0.232'', 0.280'' and 0.293'' is measured in the three filters, respectively. Gaussian disk fitting and quadratic subtraction of the science and calibrator PSFs suggests a lower-limit characteristic angular diameter of the emission of 100 mas, or 30 au. The photometric and spectroscopic results are compatible with previous findings. Our radiative transfer (RT) modeling of the continuum suggests that the resolved emission should result from PAH molecules on the disk atmosphere being UV-excited by the central star. Simple geometrical models of the PAH component compared to the underlying continuum point to a PAH emission uniformly extended out to the physical limits of the disk model. Furthermore, our RT best model of the continuum requires a negative exponent of the surface density power-law, in contrast with earlier modeling pointing to a positive exponent. Conclusions: We have spatially resolved - for the first time to our knowledge - the PAHs emission in the disk of HD 179218 and set constraints on its spatial extent. Based on spatial and spectroscopic considerations as well as on qualitative comparison with IRS 48 and HD 97048, we favor a scenario in which PAHs extend out to large radii across the flared disk surface and are at the same time predominantly in an ionized charge state due to the strong UV radiation field of the 180 L⊙ central star.

High Speed Link Radiated Emission Reduction

NASA Astrophysics Data System (ADS)

Bisognin, P.; Pelissou, P.; Cissou, R.; Giniaux, M.; Vargas, O.

2016-05-01

To control the radiated emission of high-speed link and associated unit, the current approach is to implement overall harness shielding on cables bundles. This method is very efficient in the HF/ VHF (high frequency/ very high frequency) and UHF (ultra-high frequency) ranges when the overall harness shielding is properly bonded on EMC back-shell. Unfortunately, with the increasing frequency, the associated half wavelength matches with the size of Sub-D connector that is the case for the L band. Therefore, the unit connectors become the main source of interference emission. For the L-band and S-band, the current technology of EMC back-shell leaves thin aperture matched with the L band half wavelength and therefore, the shielding effectiveness is drastically reduced. In addition, overall harness shielding means significant increases of the harness mass.Airbus D&S Toulouse and Elancourt investigated a new solution to avoid the need of overall harness shielding. The objective is to procure EM (Electro-Magnetic) clean unit connected to cables bundles free of any overall harness shielding. The proposed solution is to implement EMC common mode filtering on signal interfaces directly on unit PCB as close as possible the unit connector.Airbus D&S Elancourt designed and manufactured eight mock-ups of LVDS (Low Voltage Differential Signaling) interface PCBs' with different solutions of filtering. After verification of the signal integrity, three mock-ups were retained (RC filter and two common mode choke coil) in addition to the reference one (without EMC filter).Airbus D&S Toulouse manufactured associated LVDS cable bundles and integrated the RX (Receiver) and TX (Transmitter) LVDS boards in shielded boxes.Then Airbus D&S performed radiated emission measurement of the LVDS links subassemblies (e.g. RX and TX boxes linked by LVDS cables) according to the standard test method. This paper presents the different tested solutions and main conclusions on the feasibility of such approach.

Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Destaillats, Hugo; Chen, Wenhao; Apte, Michael

Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specimens from each filter media were exposed to {approx}150 ppbv ozone in a flow tube under a constant flow of dry or humidified air (50percent RH).more » Ozone breakthrough was recorded for each sample over periods of {approx}1000 min; the ozone uptake rate was calculated for an initial transient period and for steady-state conditions. While ozone uptake was observed in all cases, we did not observe significant differences in the uptake rate and capacity for the various types of filter media tested. Most experiments were performed at an airflow rate of 1.3 L/min (face velocity = 0.013 m/s), and a few tests were also run at higher rates (8 to 10 L/min). Formaldehyde and acetaldehyde, two oxidation byproducts, were quantified downstream of each sample. Those aldehydes (m/z 31 and 45) and other volatile byproducts (m/z 57, 59, 61 and 101) were also detected in real-time using Proton-Transfer Reaction - Mass Spectrometry (PTR-MS). Low-ppbv byproduct emissions were consistently higher under humidified air than under dry conditions, and were higher when the filters were loaded with particles, as compared with unused filters. No significant differences were observed when ozone reacted over various types of filter media. Fiberglass filters heavily coated with impaction oil (tackifier) showed higher formaldehyde emissions than other samples. Those emissions were particularly high in the case of used filters, and were observed even in the absence of ozone, suggesting that hydrolysis of additives, rather than ozonolysis, is the main formaldehyde source in those filters. Emission rates of formaldehyde and acetaldehyde were not found to be large enough to substantially increase indoor concentrations in typical building scenarios. Nevertheless, ozone reactions on HVAC filters cannot be ignored as a source of low levels of indoor irritants.« less

Io's Sodium Cloud On-Chip Format (Clear and Green-Yellow Filters Superimposed)

NASA Technical Reports Server (NTRS)

1997-01-01

This image of Jupiter's moon Io and its surrounding sky is shown in false color. The solid state imaging (CCD) system on NASA's Galileo spacecraft originally took two images of this scene, one through a clear filter and one through a green-yellow filter. [Versions of these images have been released over the past 3 days.] This picture was created by: (i) adding green color to the image taken through the green-yellow filter, and red color to the image taken through the clear filter; (ii) superimposing the two resulting images. Thus features in this picture which are purely green (or purely red) originally appeared only in the green-yellow (or clear) filter image of this scene. Features which are yellowish appeared in both filters. North is at the top, and east is to the right.

This image reveals several new things about this scene. For example:

(1) The reddish emission south of Io came dominantly through the clear filter. It therefore probably represents scattered light from Io's lit crescent and Prometheus' plume, rather than emission from Io's Sodium Cloud (which came through both filters).

(2) The roundish red spot in Io's southern hemisphere contains a small yellow spot. This means that some thermal emission from the volcano Pele was detected by the green-yellow filter (as well as by the clear filter).

(3) The sky contains several concentrated yellowish spots which were thus seen at the same location on the sky through both filters (one such spot appears in the picture's northeast corner). These spots are almost certainly stars. By contrast, the eastern half of this image contains a number of green spots whose emission was thus detected by the green-yellow filter only. Since any star visible through the green-yellow filter would also be visible through the clear filter, these green spots are probably artifacts (e.g., cosmic ray hits on the CCD sensor).

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

Motor vehicle technology:Mobility for prosperity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-01-01

This book presents the papers given at a conference on internal combustion engines for vehicles. Topics considered at the conference included combustion chambers, the lubrication of turbocharged engines, oil filters, fuel consumption, traffic control, crashworthiness, brakes, acceleration, unleaded gasoline, methanol fuels, pressure drop, safety regulations, tire vibration, detergents, fuel economy, ceramics in engines, steels, catalytic converters, fuel additives, heat exchangers, pump systems, emissions control, fuel injection systems, noise pollution control, natural gas fuels, assembly plant productivity, aerodynamics, torsion, electronics, and automatic transmissions.

Black carbon cookstove emissions: A field assessment of 19 stove/fuel combinations

NASA Astrophysics Data System (ADS)

Garland, Charity; Delapena, Samantha; Prasad, Rajendra; L'Orange, Christian; Alexander, Donee; Johnson, Michael

2017-11-01

Black carbon (BC) emissions from household cookstoves consuming solid fuel produce approximately 25 percent of total anthropogenic BC emissions. The short atmospheric lifetime of BC means that reducing BC emissions would result in a faster climate response than mitigating CO2 and other long-lived greenhouse gases. This study presents the results of optical BC measurements of two new cookstove emissions field assessments and 17 archived cookstove datasets. BC was determined from attenuation of 880 nm light, which is strongly absorbed by BC, and linearly related between 1 and 125 attenuation units. A relationship was experimentally determined correlating BC mass deposition on quartz filters determined via thermal optical analysis (TOA) and on PTFE and quartz filters using transmissometry, yielding an attenuation cross-section (σATN) for both filter media types. σATN relates TOA measurements to optical measurements on PTFE and quartz (σATN(PTFE) = 13.7 cm-2 μg, R2 = 0.87, σATN(Quartz) = 15.6 cm-2 μg, R2 = 0.87). These filter-specific σATN, optical measurements of archived filters were used to determine BC emission factors and the fraction of particulate matter (PM) in the form of black carbon (BC/PM). The 19 stoves measured fell into five stove classes; simple wood, rocket, advanced biomass, simple charcoal, and advanced charcoal. Advanced biomass stoves include forced- and natural-draft gasifiers which use wood or biomass pellets as fuel. Of these classes, the simple wood and rocket stoves demonstrated the highest median BC emission factors, ranging from 0.051 to 0.14 g MJ-1. The lowest BC emission factors were seen in charcoal stoves, which corresponds to the generally low PM emission factors observed during charcoal combustion, ranging from 0.0084 to 0.014 g MJ-1. The advanced biomass stoves generally showed an improvement in BC emissions factors compared to simple wood and rocket stoves, ranging from 0.0031 to 0.071 g MJ-1. BC/PM ratios were highest for the advanced and rocket stoves. Potential relative climate impacts were estimated by converting aerosol emissions to CO2-equivalent, and suggest that some advanced stove/fuel combinations could provide substantial climate benefits.

CONSISTENT USE OF THE KALMAN FILTER IN CHEMICAL TRANSPORT MODELS (CTMS) FOR DEDUCING EMISSIONS

EPA Science Inventory

Past research has shown that emissions can be deduced using observed concentrations of a chemical, a Chemical Transport Model (CTM), and the Kalman filter in an inverse modeling application. An expression was derived for the relationship between the "observable" (i.e., the con...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2011 CFR

2011-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2013 CFR

2013-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2012 CFR

2012-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

40 CFR 63.1187 - What do I need to know about operations, maintenance, and monitoring plans?

Code of Federal Regulations, 2014 CFR

2014-07-01

... include: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

Automatic cytometric device using multiple wavelength excitations

NASA Astrophysics Data System (ADS)

Rongeat, Nelly; Ledroit, Sylvain; Chauvet, Laurence; Cremien, Didier; Urankar, Alexandra; Couderc, Vincent; Nérin, Philippe

2011-05-01

Precise identification of eosinophils, basophils, and specific subpopulations of blood cells (B lymphocytes) in an unconventional automatic hematology analyzer is demonstrated. Our specific apparatus mixes two excitation radiations by means of an acousto-optics tunable filter to properly control fluorescence emission of phycoerythrin cyanin 5 (PC5) conjugated to antibodies (anti-CD20 or anti-CRTH2) and Thiazole Orange. This way our analyzer combining techniques of hematology analysis and flow cytometry based on multiple fluorescence detection, drastically improves the signal to noise ratio and decreases the spectral overlaps impact coming from multiple fluorescence emissions.

Will Aerosol Hygroscopicity Change with Biodiesel, Renewable Diesel Fuels and Emission Control Technologies?

PubMed

Vu, Diep; Short, Daniel; Karavalakis, Georgios; Durbin, Thomas D; Asa-Awuku, Akua

2017-02-07

The use of biodiesel and renewable diesel fuels in compression ignition engines and aftertreatment technologies may affect vehicle exhaust emissions. In this study two 2012 light-duty vehicles equipped with direct injection diesel engines, diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) were tested on a chassis dynamometer. One vehicle was tested over the Federal Test Procedure (FTP) cycle on seven biodiesel and renewable diesel fuel blends. Both vehicles were exercised over double Environmental Protection Agency (EPA) Highway fuel economy test (HWFET) cycles on ultralow sulfur diesel (ULSD) and a soy-based biodiesel blend to investigate the aerosol hygroscopicity during the regeneration of the DPF. Overall, the apparent hygroscopicity of emissions during nonregeneration events is consistently low (κ < 0.1) for all fuels over the FTP cycle. Aerosol emitted during filter regeneration is significantly more CCN active and hygroscopic; average κ values range from 0.242 to 0.439 and are as high as 0.843. Regardless of fuel, the current classification of "fresh" tailpipe emissions as nonhygroscopic remains true during nonregeneration operation. However, aftertreatment technologies such as DPF, will produce significantly more hygroscopic particles during regeneration. To our knowledge, this is the first study to show a significant enhancement of hygroscopic materials emitted during DPF regeneration of on-road diesel vehicles. As such, the contribution of regeneration emissions from a growing fleet of diesel vehicles will be important.

Tunable filters for multispectral imaging of aeronomical features

NASA Astrophysics Data System (ADS)

Goenka, C.; Semeter, J. L.; Noto, J.; Dahlgren, H.; Marshall, R.; Baumgardner, J.; Riccobono, J.; Migliozzi, M.

2013-10-01

Multispectral imaging of optical emissions in the Earth's upper atmosphere unravels vital information about dynamic phenomena in the Earth-space environment. Wavelength tunable filters allow us to accomplish this without using filter wheels or multiple imaging setups, but with identifiable caveats and trade-offs. We evaluate one such filter, a liquid crystal Fabry-Perot etalon, as a potential candidate for the next generation of imagers for aeronomy. The tunability of such a filter can be exploited in imaging features such as the 6300-6364 Å oxygen emission doublet, or studying the rotational temperature of N2+ in the 4200-4300 Å range, observations which typically require multiple instruments. We further discuss the use of this filter in an optical instrument, called the Liquid Crystal Hyperspectral Imager (LiCHI), which will be developed to make simultaneous measurements in various wavelength ranges.

Building and Testing a Portable VLF Receiver

NASA Technical Reports Server (NTRS)

McLaughlin, Robert; Krause, L.

2014-01-01

Unwanted emissions or signal noise is a major problem for VLF radio receivers. These can occur from man made sources such as power line hum, which can be prevalent for many harmonics after the fundamental 50 or 60 Hz AC source or from VLF radio transmissions such as LORAN, used for navigation and communications. Natural emissions can also be detrimental to the quality of recordings as some of the more interesting natural emissions such as whistlers or auroral chorus may be drowned out by the more common sferic emissions. VLF receivers must selectively filter out unwanted emissions and amplify the filtered signal to a record-able level without degrading the quality.

47 CFR 90.210 - Emission masks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... profile is developed. If video filtering is used, its bandwidth must not be less than the instrument... sufficient number of sweeps must be measured to insure that the emission profile is developed. If video... with 1 MHz of the edge of the authorized subband. The video filter bandwidth shall not be less than the...

47 CFR 90.210 - Emission masks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... profile is developed. If video filtering is used, its bandwidth must not be less than the instrument... sufficient number of sweeps must be measured to insure that the emission profile is developed. If video... with 1 MHz of the edge of the authorized subband. The video filter bandwidth shall not be less than the...

47 CFR 90.210 - Emission masks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... profile is developed. If video filtering is used, its bandwidth must not be less than the instrument... sufficient number of sweeps must be measured to insure that the emission profile is developed. If video... with 1 MHz of the edge of the authorized subband. The video filter bandwidth shall not be less than the...

New transparent flexible nanopaper as ultraviolet filter based on red emissive Eu(III) nanofibrillated cellulose

NASA Astrophysics Data System (ADS)

Zhang, Zhao; Chang, Hui; Xue, Bailiang; Han, Qing; Lü, Xingqiang; Zhang, Sufeng; Li, Xinping; Zhu, Xunjin; Wong, Wai-kwok; Li, Kecheng

2017-11-01

A new kind of highly red emissive and transparent nanopapers as ultraviolet filter are produced from lanthanide complex Eu(TTA)3(H2O)2 grafted nanofibrillated cellulose (NFC) by a filtration process using a Buchner funnel. The nanopapers Eu-NFC 1-4 with different thickness (0.023 mm, 1; 0.04 mm, 2; 0.081 mm, 3 and 0.1 mm, 4) possess a fibres with dimensions of approximately 50 nm in diameter and several micrometres in length. Those nanopapers exhibit excellent ultraviolet A (UVA; 320-400 nm) filter property and high optical transmittance (>73% at wavelength of 600 nm). The presence of Eu(TTA)3(H2O)2 in Eu-NFC nanopapers can block 97% UVA (at 348 nm) light and convert it into pure red emission (CIE: x = 0.663, y = 0.333) through the efficient triplet-triplet energy transfer process. The efficient red emission can significantly improve the photo-stability of β-diketones type UVA filter. It can sustain for 10 h without decomposition under UV irradiation at 365 nm, which makes it possible to be applied in UVA filters. Moreover, its low coefficient of thermal expansion (CTE: 6.39 ppm K-1 of nanocellulose), is superior to petroleum-based materials for red organic light-emitting devices.

Aerial Sampling of Emissions from Biomass Pile Burns in ...

EPA Pesticide Factsheets

Abstract (already cleared). Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determines the first known in-field emission factors for burning of timber slash piles. The results also document the effect on emissions of covering the piles with polyethylene covers to reduce the moisture content of the biomass.

Heavy-Duty Stoichiometric Compression Ignition Engine with Improved Fuel Economy over Alternative Technologies for Meeting 2010 On-Highway Emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirby J. Baumgard; Richard E. Winsor

2009-12-31

The objectives of the reported work were: to apply the stoichiometric compression ignition (SCI) concept to a 9.0 liter diesel engine; to obtain engine-out NO{sub x} and PM exhaust emissions so that the engine can meet 2010 on-highway emission standards by applying a three-way catalyst for NO{sub x} control and a particulate filter for PM control; and to simulate an optimize the engine and air system to approach 50% thermal efficiency using variable valve actuation and electric turbo compounding. The work demonstrated that an advanced diesel engine can be operated at stoichiometric conditions with reasonable particulate and NOx emissions atmore » full power and peak torque conditions; calculated that the SCI engine will operate at 42% brake thermal efficiency without advanced hardware, turbocompounding, or waste heat recovery; and determined that EGR is not necessary for this advanced concept engine, and this greatly simplifies the concept.« less

Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF.

PubMed

Ma, T; Izumi, N; Tommasini, R; Bradley, D K; Bell, P; Cerjan, C J; Dixit, S; Döppner, T; Jones, O; Kline, J L; Kyrala, G; Landen, O L; LePape, S; Mackinnon, A J; Park, H-S; Patel, P K; Prasad, R R; Ralph, J; Regan, S P; Smalyuk, V A; Springer, P T; Suter, L; Town, R P J; Weber, S V; Glenzer, S H

2012-10-01

Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

Emission rates of sulfur dioxide, trace gases and metals from Mount Erebus, Antartica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyle, P.R.; Meeker, K.; Finnegan, D.

1990-11-01

SO{sub 2} emission rates have been measured annually since 1983 at Mount Erebus, Antarctica by correlation spectrometer (COSPEC V). Following a 4 month period of sustained strombolian activity in late 1984, SO{sub 2} emissions declined from 230 Mg/day in 1983 to 25 Mg/day and then slowly increased from 16 Mg/day in 1985 to 51 Mg/day in 1987. Nine sets of filter packs containing partcle and {sup 7}LiOH treated filters were collected in the plume in 1986 and analyzed by neutron activation. Using the COSPEC data and measured element/S ratios on the filters, emission rates have been determined for trace gasesmore » and metals. The authors infer HCl and HF emissions in 1983 to be about 1200 and 500 Mg/day, respectively. Mt Erebus has therefore been an important source of halogens to the Anarctic atmosphere and could be responsible for excess Cl found in Central Antarctica snow.« less

Variability of particle number emissions from diesel and hybrid diesel-electric buses in real driving conditions.

PubMed

Sonntag, Darrell B; Gao, H Oliver; Holmén, Britt A

2008-08-01

A linear mixed model was developed to quantify the variability of particle number emissions from transit buses tested in real-world driving conditions. Two conventional diesel buses and two hybrid diesel-electric buses were tested throughout 2004 under different aftertreatments, fuels, drivers, and bus routes. The mixed model controlled the confounding influence of factors inherent to on-board testing. Statistical tests showed that particle number emissions varied significantly according to the after treatment, bus route, driver, bus type, and daily temperature, with only minor variability attributable to differences between fuel types. The daily setup and operation of the sampling equipment (electrical low pressure impactor) and mini-dilution system contributed to 30-84% of the total random variability of particle measurements among tests with diesel oxidation catalysts. By controlling for the sampling day variability, the model better defined the differences in particle emissions among bus routes. In contrast, the low particle number emissions measured with diesel particle filters (decreased by over 99%) did not vary according to operating conditions or bus type but did vary substantially with ambient temperature.

40 CFR 60.2680 - What if I do not use a wet scrubber, fabric filter, activated carbon injection, selective...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., fabric filter, activated carbon injection, selective noncatalytic reduction, an electrostatic... use a wet scrubber, fabric filter, activated carbon injection, selective noncatalytic reduction, an... reduction, fabric filter, an electrostatic precipitator, or a dry scrubber or limit emissions in some other...

40 CFR 60.2680 - What if I do not use a wet scrubber, fabric filter, activated carbon injection, selective...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., fabric filter, activated carbon injection, selective noncatalytic reduction, an electrostatic... use a wet scrubber, fabric filter, activated carbon injection, selective noncatalytic reduction, an... reduction, fabric filter, an electrostatic precipitator, or a dry scrubber or limit emissions in some other...

40 CFR 1065.1107 - Sample media and sample system preparation; sample system assembly.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) For capturing PM, we recommend using pure quartz filters with no binder. Select the filter diameter to minimize filter change intervals, accounting for the expected PM emission rate, sample flow rate, and... filter without replacing the sorbent or otherwise disassembling the batch sampler. In those cases...

High brightness diode lasers controlled by volume Bragg gratings

NASA Astrophysics Data System (ADS)

Glebov, Leonid

2017-02-01

Volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass are holographic optical elements that are effective spectral and angular filters withstanding high power laser radiation. Reflecting VBGs are narrow-band spectral filters while transmitting VBGs are narrow-band angular filters. The use of these optical elements in external resonators of semiconductor lasers enables extremely resonant feedback that provides dramatic spectral and angular narrowing of laser diodes radiation without significant power and efficiency penalty. Spectral narrowing of laser diodes by reflecting VBGs demonstrated in wide spectral region from near UV to 3 μm. Commercially available VBGs have spectral width ranged from few nanometers to few tens of picometers. Efficient spectral locking was demonstrated for edge emitters (single diodes, bars, modules, and stacks), vertical cavity surface emitting lasers (VCSELs), grating coupled surface emitting lasers (GCSELs), and interband cascade lasers (ICLs). The use of multiplexed VBGs provides multiwavelength emission from a single emitter. Spectrally locked semiconductor lasers demonstrated CW power from milliwatts to a kilowatt. Angular narrowing by transmitting VBGs enables single transverse mode emission from wide aperture diode lasers having resonators with great Fresnel numbers. This feature provides close to diffraction limit divergence along a slow axis of wide stripe edge emitters. Radiation exchange between lasers by means of spatially profiled or multiplexed VBGs enables coherent combining of diode lasers. Sequence of VBGs or multiplexed VBGs enable spectral combining of spectrally narrowed diode lasers or laser modules. Thus the use of VBGs for diode lasers beam control provides dramatic increase of brightness.

PCDD/F emissions during startup and shutdown of a hazardous waste incinerator.

PubMed

Li, Min; Wang, Chao; Cen, Kefa; Ni, Mingjiang; Li, Xiaodong

2017-08-01

Compared with municipal solid waste incineration, studies on the PCDD/F emissions of hazardous waste incineration (HWI) under transient conditions are rather few. This study investigates the PCDD/F emission level, congener profile and removal efficiency recorded during startup and shutdown by collecting flue gas samples at the bag filter inlet and outlet and at the stack. The PCDD/F concentration measured in the stack gas during startup and shutdown were 0.56-4.16 ng I-TEQ Nm -3 and 1.09-3.36 ng I-TEQ Nm -3 , respectively, far exceeding the present codes in China. The total amount of PCDD/F emissions, resulting from three shutdown-startup cycles of this HWI-unit is almost equal to that generated during one year under normal operating conditions. Upstream the filter, the PCDD/F in the flue gas is mainly in the particle phase; however, after being filtered PCDD/F prevails in the gas phase. The PCDD/F fraction in the gas phase even exceeds 98% after passing through the alkaline scrubber. Especially higher chlorinated PCDD/F accumulate on inner walls of filters and ducts during these startup periods and could be released again during normal operation, significantly increasing PCDD/F emissions. Copyright © 2017. Published by Elsevier Ltd.

[Risk management of soybean-related asthma: monitoring and surveillance].

PubMed

Villalbí, Joan R; Carrascal, Dolors; Caylà, Joan A; Rodríguez, Pau; Cruz, M A Jesús; Pintó, Josep M

2011-01-01

Allergen emissions during soybean unloading operations in the Barcelona harbor have caused asthma epidemics. The present article aimed to describe the surveillance and control measures carried out by the public health services. Data were extracted from control systems from 1999 to 2009, with description of the surveillance schemes for allergen emissions, environmental concentrations (with defined reference levels) and for health. Of 95 studies of plant emission, four were above the reference levels, and filters were found to be the most likely cause. Mean environmental concentrations were low but were above the reference levels on 13 days; these levels were related to adverse meteorological conditions and incidents in the plants. No health effects were detected in the panel of patients nor epidemic asthma days. The system detects incidents and has shown its usefulness in protecting public health. Copyright © 2011 SESPAS. Published by Elsevier Espana. All rights reserved.

Real-world emissions of in-use off-road vehicles in Mexico.

PubMed

Zavala, Miguel; Huertas, Jose Ignacio; Prato, Daniel; Jazcilevich, Aron; Aguilar, Andrés; Balam, Marco; Misra, Chandan; Molina, Luisa T

2017-09-01

Off-road vehicles used in construction and agricultural activities can contribute substantially to emissions of gaseous pollutants and can be a major source of submicrometer carbonaceous particles in many parts of the world. However, there have been relatively few efforts in quantifying the emission factors (EFs) and for estimating the potential emission reduction benefits using emission control technologies for these vehicles. This study characterized the black carbon (BC) component of particulate matter and NOx, CO, and CO 2 EFs of selected diesel-powered off-road mobile sources in Mexico under real-world operating conditions using on-board portable emissions measurements systems (PEMS). The vehicles sampled included two backhoes, one tractor, a crane, an excavator, two front loaders, two bulldozers, an air compressor, and a power generator used in the construction and agricultural activities. For a selected number of these vehicles the emissions were further characterized with wall-flow diesel particle filters (DPFs) and partial-flow DPFs (p-DPFs) installed. Fuel-based EFs presented less variability than time-based emission rates, particularly for the BC. Average baseline EFs in working conditions for BC, NOx, and CO ranged from 0.04 to 5.7, from 12.6 to 81.8, and from 7.9 to 285.7 g/kg-fuel, respectively, and a high dependency by operation mode and by vehicle type was observed. Measurement-base frequency distributions of EFs by operation mode are proposed as an alternative method for characterizing the variability of off-road vehicles emissions under real-world conditions. Mass-based reductions for black carbon EFs were substantially large (above 99%) when DPFs were installed and the vehicles were idling, and the reductions were moderate (in the 20-60% range) for p-DPFs in working operating conditions. The observed high variability in measured EFs also indicates the need for detailed vehicle operation data for accurately estimating emissions from off-road vehicles in emissions inventories. Measurements of off-road vehicles used in construction and agricultural activities in Mexico using on-board portable emissions measurements systems (PEMS) showed that these vehicles can be major sources of black carbon and NO X . Emission factors varied significantly under real-world operating conditions, suggesting the need for detailed vehicle operation data for accurately estimating emissions inventories. Tests conducted in a selected number of sampled vehicles indicated that diesel particle filters (DPFs) are an effective technology for control of diesel particulate emissions and can provide potentially large emissions reduction in Mexico if widely implemented.

UV filters for lighting of plants

NASA Astrophysics Data System (ADS)

Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H. K.; Payer, H. D.

1994-03-01

The wavelength dependent interaction of biological systems with radiation is commonly described by appropriate action spectra. Particularly effective plant responses are obtained for ultraviolet (UV) radiation. Excess shortwave UV-B radiation will induce genetic defects and plant damage. Besides the ecological discussion of the deleterious effects of the excess UV radiation there is increasing interest in horticultural applications of this spectral region. Several metabolic pathways leading to valuable secondary plant products like colors, odors, taste, or resulting in mechanical strength and vitality are triggered by UV radiation. Thus, in ecologically as well as in economically oriented experiments the exact generation and knowledge of the spectral irradiance, particularly near the UV absorption edge, is essential. The ideal filter 'material' to control the UV absorption edge would be ozone itself. However, due to problems in controlling the toxic and chemically aggressive, instable gas, only rather 'small ozone filters' have been realized so far. In artificial plant lighting conventional solid filter materials such as glass sheets and plastic foils (celluloseacetate or cellulosetriacetate) which can be easily handled have been used to absorb the UV-C and the excess shortwave UV-B radiation of the lamp emissions. Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The aging of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In any case chamber experiments require a careful selection of the filter material used and must be accompanied by a continuous UV-B monitoring.

UV filters for lighting of plants

NASA Technical Reports Server (NTRS)

Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H. K.; Payer, H. D.

1994-01-01

The wavelength dependent interaction of biological systems with radiation is commonly described by appropriate action spectra. Particularly effective plant responses are obtained for ultraviolet (UV) radiation. Excess shortwave UV-B radiation will induce genetic defects and plant damage. Besides the ecological discussion of the deleterious effects of the excess UV radiation there is increasing interest in horticultural applications of this spectral region. Several metabolic pathways leading to valuable secondary plant products like colors, odors, taste, or resulting in mechanical strength and vitality are triggered by UV radiation. Thus, in ecologically as well as in economically oriented experiments the exact generation and knowledge of the spectral irradiance, particularly near the UV absorption edge, is essential. The ideal filter 'material' to control the UV absorption edge would be ozone itself. However, due to problems in controlling the toxic and chemically aggressive, instable gas, only rather 'small ozone filters' have been realized so far. In artificial plant lighting conventional solid filter materials such as glass sheets and plastic foils (celluloseacetate or cellulosetriacetate) which can be easily handled have been used to absorb the UV-C and the excess shortwave UV-B radiation of the lamp emissions. Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The aging of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In any case chamber experiments require a careful selection of the filter material used and must be accompanied by a continuous UV-B monitoring.

Io's Sodium Cloud (Clear and Green-Yellow Filters)

NASA Technical Reports Server (NTRS)

1997-01-01

The green-yellow filter and clear filter images of Io which were released over the past two days were originally exposed on the same frame. The camera pointed in slightly different directions for the two exposures, placing a clear filter image of Io on the top half of the frame, and a green-yellow filter image of Io on the bottom half of the frame. This picture shows that entire original frame in false color, the most intense emission appearing white.

East is to the right. Most of Io's visible surface is in shadow, though one can see part of an illuminated crescent on its western side. The burst of white light near Io's eastern equatorial edge (most distinctive in the green filter image) is sunlight scattered by the plume of the volcano Prometheus.

There is much more bright light near Io in the clear filter image, since that filter's wider wavelength range admits more scattered light from Prometheus' sunlit plume and Io's illuminated crescent. Thus in the clear filter image especially, Prometheus's plume was bright enough to produce several white spikes which extend radially outward from the center of the plume emission. These spikes are artifacts produced by the optics of the camera. Two of the spikes in the clear filter image appear against Io's shadowed surface, and the lower of these is pointing towards a bright round spot. That spot corresponds to thermal emission from the volcano Pele.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

In-filter PCDF and PCDD formation at low temperature during MSWI combustion.

PubMed

Weidemann, Eva; Marklund, Stellan; Bristav, Henrik; Lundin, Lisa

2014-05-01

This case study investigated PCDF and PCDD emissions from a 65 MW waste-to-energy plant to identify why an air pollution control system remodeling to accommodate increased production resulted in increased TEQ concentrations. Pre- and post-filter gases were collected simultaneously in four sample sets with varying filter temperatures and with/without activated carbon injection. Samples were analyzed to determine total PCDF and PCDD concentrations, as well as homologue profiles, and concentrations of individual congeners (some remained co-eluted). The total post filter PCDD concentrations where found to increase while the concentrations of PCDF and 2,3,7,8-substituted congeners declined. An investigation of the individual congener concentrations revealed that the increase of PCDD concentrations were due to a few congeners, suggesting a single formation route. The study also concludes that vital information about the formation could be obtained by not restricting the analysis to just the 2,3,7,8-substituted congeners. Copyright © 2013 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, A. H.; Yee, L. D.; Issacman-VanWertz, G.

In areas where biogenic emissions are oxidized in the presence of anthropogenic pollutants such as SO2, NOx, and black carbon, it has become increasingly apparent that secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (VOCs) is substantially enhanced. Research is urgently needed to elucidate fundamental processes of natural and anthropogenically influenced VOC oxidation and the contribution of these processes to SOA formation. GoAmazon 2014/15 afforded study of the chemical transformations in the region downwind of Manaus, Brazil, where local biogenic VOC emissions are high, and their chemical oxidation can be studied both inside and outside of the urbanmore » plume to differentiate the role of anthropogenic influence on secondary aerosol formation during oxidation of these natural VOC emissions. To understand the connection between primary biogenic VOC emissions and their secondary products that form aerosols, we made time-resolved molecular level measurements by deploying a Semi-Volatile Thermal Desorption Aerosol Gas Chromatograph (SV-TAG) and a sequential filter sampler during two intensive operational periods (IOPs) of the GoAmazon 2014/15 field campaign. The SV-TAG measured semi-volatile organic compounds in both the gas and particle phases and the sequential filter sampler collected aerosols on quartz fiber filters in four-hour increments used for offline analysis. SV-TAG employed novel online derivatization that provided chemical speciation of highly oxygenated or functionalized compounds that comprise a substantial fraction of secondary organic aerosols, yet are poorly characterized. It also provided partitioning of these compounds between the vapor and particle phases at sufficient time resolution to define the importance of competing atmospheric processes. These measurements were supported by offline analysis of the filters using two-dimensional gas chromatography (GC x GC) with high-resolution time-of-flight mass spectrometry (HR-TOF-MS) using both electron impact (EI) and soft vacuum ultraviolet (VUV) ionization with derivatization. Speciated chemical data from SV-TAG and filter measurements were used to elucidate the relative importance of potential oxidation pathways by providing detailed information on the product distribution from atmospheric reactions and the quantification of known tracers for various oxidation pathways. Together, these techniques provided unequivocal molecular identification of a wide range of atmospheric organic compounds spanning the volatile, semi-volatile, and non-volatile phases. This level of chemical characterization provided insight into the chemical and physical processes that control the atmospheric oxidation of biogenic VOC and subsequent formation of SOA.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kowalski, Adam F.; Mathioudakis, Mihalis; Hawley, Suzanne L.

We present a large data set of high-cadence dMe flare light curves obtained with custom continuum filters on the triple-beam, high-speed camera system ULTRACAM. The measurements provide constraints for models of the near-ultraviolet (NUV) and optical continuum spectral evolution on timescales of ≈1 s. We provide a robust interpretation of the flare emission in the ULTRACAM filters using simultaneously obtained low-resolution spectra during two moderate-sized flares in the dM4.5e star YZ CMi. By avoiding the spectral complexity within the broadband Johnson filters, the ULTRACAM filters are shown to characterize bona fide continuum emission in the NUV, blue, and red wavelength regimes. Themore » NUV/blue flux ratio in flares is equivalent to a Balmer jump ratio, and the blue/red flux ratio provides an estimate for the color temperature of the optical continuum emission. We present a new “color–color” relationship for these continuum flux ratios at the peaks of the flares. Using the RADYN and RH codes, we interpret the ULTRACAM filter emission using the dominant emission processes from a radiative-hydrodynamic flare model with a high nonthermal electron beam flux, which explains a hot, T ≈ 10{sup 4} K, color temperature at blue-to-red optical wavelengths and a small Balmer jump ratio as observed in moderate-sized and large flares alike. We also discuss the high time resolution, high signal-to-noise continuum color variations observed in YZ CMi during a giant flare, which increased the NUV flux from this star by over a factor of 100.« less

Polycyclic aromatic hydrocarbon (PAH) emissions from a coal-fired pilot FBC system.

PubMed

Liu, K; Han, W; Pan, W P; Riley, J T

2001-06-29

Due to the extensive amount of data suggesting the hazards of these compounds, 16 polycyclic aromatic hydrocarbons (PAHs) are on the Environmental Protection Agency (EPA) Priority Pollutant List. Emissions of these PAHs in the flue gas from the combustion of four coals were measured during four 1000h combustion runs using the 0.1MW heat-input (MWth) bench-scale fluidized bed combustor (FBC). An on-line sampling system was designed for the 16 PAHs, which consisted of a glass wool filter, condenser, glass fiber filter, Teflon filter, and a Tenax trap. The filters and Tenax were extracted by methylene chloride and hexane, respectively, followed by GC/MS analysis using the selective ion monitoring (SIM) mode. In this project, the effects of operating parameters, limestone addition, chlorine content in the coal, and Ca/S molar ratio on the emissions of PAHs were studied. The results indicated that the emissions of PAHs in an FBC system are primarily dependent on the combustion temperature and excess air ratio. The injection of secondary air with high velocity in the freeboard effectively reduces PAH emissions. The addition of extra limestone can promote the formation of PAHs in the FBC system. Chlorine in the coal can possibly lead to large benzene ring PAH formation during combustion. The total PAH emission increases with an increase in the sulfur content of coal. Incomplete combustion results in PAHs with four or more benzene rings. High efficiency combustion results in PAHs with two or three benzene rings.

Study of acoustic emission during mechanical tests of large flight weight tank structure

NASA Technical Reports Server (NTRS)

Mccauley, B. O.; Nakamura, Y.; Veach, C. L.

1973-01-01

A PPO-insulated, flight-weight, subscale, aluminum tank was monitored for acoustic emissions during a proof test and during 100 cycles of environmental test simulating space flights. The use of a combination of frequency filtering and appropriate spatial filtering to reduce background noise was found to be sufficient to detect acoustic emission signals of relatively small intensity expected from subcritical crack growth in the structure. Several emission source locations were identified, including the one where a flaw was detected by post-test x-ray inspections. For most source locations, however, post-test inspections did not detect flaws; this was partially attributed to the higher sensitivity of the acoustic emission technique than any other currently available NDT method for detecting flaws. For these non-verifiable emission sources, a problem still remains in correctly interpreting observed emission signals.

Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009

USGS Publications Warehouse

Pfeffer, Melissa; Doukas, Michael P.; Werner, Cynthia A.; Evans, William C.

2013-01-01

Filter pack data from six airborne campaigns at Redoubt Volcano, Alaska are reported here. These measurements provide a rare constraint on Cl output from an andesitic eruption at high emission rate (> 104 t d− 1 SO2). Four S/Cl ratios measured during a period of lava dome growth indicate a depth of last magma equilibration of 2–5 km. The S/Cl ratios in combination with COSPEC SO2 emission rate measurements indicate HCl emission rates of 1500–3600 t d− 1 during dome growth. SO2 and HCl emission rates at Redoubt Volcano correlate with each other and were low prior to the eruption, high during the eruption, and low after the eruption. S/Cl ratios measured by filter pack at andesitic volcanoes have a small range of variance, with no clear trends seen for eruptive versus passive activity. The very few S/Cl ratio measurements by filter pack at andesitic volcanoes are not as predictive of future volcanic activity as has been demonstrated for basaltic volcanoes. This may be because there are so few of these measurements. We have demonstrated it is possible to collect these samples by air between explosions during lava dome-building eruptions. We recommend more filter pack sampling be performed at andesitic volcanoes to determine the technique's utility for volcano monitoring. Filter pack data has been demonstrated to be useful for calculating the depth of magma equilibration at volcanoes including Redoubt Volcano.

Effect of open channel filter on particle emissions of modern diesel engine.

PubMed

Heikkilä, Juha; Rönkkö, Topi; Lähde, Tero; Lemmetty, Mikko; Arffman, Anssi; Virtanen, Annele; Keskinen, Jorma; Pirjola, Liisa; Rothe, Dieter

2009-10-01

Particle emissions of modern diesel engines are of a particular interest because of their negative health effects. The special interest is in nanosized solid particles. The effect of an open channel filter on particle emissions of a modern heavy-duty diesel engine (MAN D2066 LF31, model year 2006) was studied. Here, the authors show that the open channel filter made from metal screen efficiently reduced the number of the smallest particles and, notably, the number and mass concentration of soot particles. The filter used in this study reached 78% particle mass reduction over the European Steady Cycle. Considering the size-segregated number concentration reduction, the collection efficiency was over 95% for particles smaller than 10 nm. The diffusion is the dominant collection mechanism in small particle sizes, thus the collection efficiency decreased as particle size increased, attaining 50% at 100 nm. The overall particle number reduction was 66-99%, and for accumulation-mode particles the number concentration reduction was 62-69%, both depending on the engine load.

Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

PubMed

Clack, Herek L

2012-07-03

The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions.

No significant interactions between nitrogen stimulation and ozone inhibition of isoprene emission in Cathay poplar.

PubMed

Yuan, Xiangyang; Shang, Bo; Xu, Yansen; Xin, Yue; Tian, Yuan; Feng, Zhaozhong; Paoletti, Elena

2017-12-01

Isoprene emission from plants subject to a combination of ozone (O 3 ) and nitrogen (N) has never been investigated. Cathay poplar (Populus cathayana) saplings were exposed to O 3 (CF, charcoal-filtered air, NF, non-filtered ambient air and E-O 3 , non-filtered air +40ppb) and N treatments (N0, 0kgNha -1 year -1 , N50, 50kgNha -1 year -1 and N100, 100kgNha -1 year -1 ) for 96days. Increasing O 3 exposure decreased isoprene emission (11.5% in NF and 57.9% in E-O 3 ), as well as light-saturated photosynthetic rate (A sat ) and chlorophyll content, while N load increased isoprene emission (19.6% in N50 and 33.4% in N100) as well as A sat and chlorophyll content. Although O 3 and N interacted significantly in A sat , N did not mitigate the negative effects of O 3 on isoprene emission, i.e. the combined effects were additive and did not interact. These results warrant more research on the combined effects of co-existing global change factors on future isoprene emission and atmospheric chemical processes. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false PM sampling media (e.g., filters... Specified Duty Cycles § 1065.590 PM sampling media (e.g., filters) preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM sampling media (e.g., filters) and equipment...

40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false PM sampling media (e.g., filters... Specified Duty Cycles § 1065.590 PM sampling media (e.g., filters) preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM sampling media (e.g., filters) and equipment...

40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false PM sampling media (e.g., filters... Specified Duty Cycles § 1065.590 PM sampling media (e.g., filters) preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM sampling media (e.g., filters) and equipment...

40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false PM sampling media (e.g., filters... Specified Duty Cycles § 1065.590 PM sampling media (e.g., filters) preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM sampling media (e.g., filters) and equipment...

40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false PM sampling media (e.g., filters... Specified Duty Cycles § 1065.590 PM sampling media (e.g., filters) preconditioning and tare weighing. Before an emission test, take the following steps to prepare PM sampling media (e.g., filters) and equipment...

Study of acoustic emission during mechanical tests of large flight weight tank structure

NASA Technical Reports Server (NTRS)

Nakamura, Y.; Mccauley, B. O.; Veach, C. L.

1972-01-01

A polyphenylane oxide insulated, flight weight, subscale, aluminum tank was monitored for acoustic emissions during a proof test and during 100 cycles of environmental test simulating space flights. The use of a combination of frequency filtering and appropriate spatial filtering to reduce background noise was found to be sufficient to detect acoustic emission signals of relatively small intensity expected from subcritical crack growth in the structure. Several emission source locations were identified, including the one where a flaw was detected by post-test X-ray inspections. For most source locations, however, post-test inspections did not detect flaws; this was partially attributed to the higher sensitivity of the acoustic emission technique than any other currently available NDT method for detecting flaws.

Novel diesel exhaust filters for underground mining vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bickel, K.L.; Taubert, T.R.

1995-12-31

The U.S. Bureau of Mines (USBM) pioneered the development of disposable filters for reducing diesel particulate emissions from permissible mining machines. The USBM is now evaluating filter media that can withstand the high exhaust temperatures on nonpermissible machines. The goal of the evaluation is to find an inexpensive medium that can be cleaned or disposed of after use, and will reduce particulate emissions by 50 % or more. This report summarizes the results from screening tests of a lava rock and woven fiberglass filter media. The lava rock media exhibited low collection efficiencies, but with very low increases in exhaustmore » back pressure. Preliminary results indicate a collection efficiency exceeding 80 % for the woven fiber media. Testing of both media is continuing.« less

Oxidative Stress and Aromatic Hydrocarbon Response of Human Bronchial Epithelial Cells Exposed to Petro- or Biodiesel Exhaust Treated with a Diesel Particulate Filter

PubMed Central

Hawley, Brie; L'Orange, Christian; Olsen, Dan B.; Marchese, Anthony J.; Volckens, John

2014-01-01

The composition of diesel exhaust has changed over the past decade due to the increased use of alternative fuels, like biodiesel, and to new regulations on diesel engine emissions. Given the changing nature of diesel fuels and diesel exhaust emissions, a need exists to understand the human health implications of switching to “cleaner” diesel engines run with particulate filters and engines run on alternative fuels like biodiesel. We exposed well-differentiated normal human bronchial epithelial cells to fresh, complete exhaust from a diesel engine run (1) with and without a diesel particulate filter and (2) using either traditional petro- or alternative biodiesel. Despite the lowered emissions in filter-treated exhaust (a 91–96% reduction in mass), significant increases in transcripts associated with oxidative stress and polycyclic aromatic hydrocarbon response were observed in all exposure groups and were not significantly different between exposure groups. Our results suggest that biodiesel and filter-treated diesel exhaust elicits as great, or greater a cellular response as unfiltered, traditional petrodiesel exhaust in a representative model of the bronchial epithelium. PMID:25061111

Deterministic filtering of breakdown flashing at telecom wavelengths

NASA Astrophysics Data System (ADS)

Marini, Loris; Camphausen, Robin; Eggleton, Benjamin J.; Palomba, Stefano

2017-11-01

Breakdown flashes are undesired photo-emissions from the active area of single-photon avalanche photo-diodes. They arise from radiative recombinations of hot carriers generated during an avalanche and can induce crosstalk, compromise the measurement of optical quantum states, and hinder the security of quantum communications. Although the spectrum of this emission extends over hundreds of nanometers, active quenching may lead to a smaller uncertainty in the time of emission, thus enabling deterministic filtering. Our results pave the way to broadband interference mitigation in time-correlated single-photon applications.

Test/QA plan for the verification testing of diesel exhaust catalysts, particulate filters and engine modification control technologies for highway and nonroad use diesel engines

EPA Science Inventory

This ETV test/QA plan for heavy-duty diesel engine testing at the Southwest Research Institute’s Department of Emissions Research (DER) describes how the Federal Test Procedure (FTP), as listed in 40 CFR Part 86 for highway engines and 40 CFR Part 89 for nonroad engines, will be ...

Effects of Aftermarket Control Technologies on Gas and Particle Phase Oxidative Potential from Diesel Engine Emissions.

PubMed

Pavlovic, Jelica; Holder, Amara L; Yelverton, Tiffany L B

2015-09-01

Particulate matter (PM) originating from diesel combustion is a public health concern due to its association with adverse effects on respiratory and cardiovascular diseases and lung cancer. This study investigated emissions from three stationary diesel engines (gensets) and varying power output (230 kW, 400 kW, and 600 kW) at 50% and 90% load to determine concentrations of gaseous (GROS) and PM reactive oxygen species (PMROS). In addition, the influence of three modern emission control technologies on ROS emissions was evaluated: active and passive diesel particulate filters (A-DPF and P-DPF) and a diesel oxidation catalyst (DOC). PMROS made up 30-50% of the total ROS measured without aftermarket controls. All applied controls removed PMROS by more than 75% on average. However, the oxidative potential of PM downstream of these devices was not diminished at the same rate and particles surviving the A-PDF had an even higher oxidative potential on a per PM mass basis compared to the particles emitted by uncontrolled gensets. Further, the GROS as compared to PMROS emissions were not reduced with the same efficiency (<36%). GROS concentrations were highest with the DOC in use, indicating continued formation of GROS with this control. Correlation analyses showed that PMROS and to a lesser extent GROS have a good correlation with semivolatile organic carbon (OC1) subfraction. In addition, results suggest that chemical composition, rather than PM size, is responsible for differences in the PM oxidative potential.

Emissions from prescribed burning of timber slash piles in Oregon

NASA Astrophysics Data System (ADS)

Aurell, Johanna; Gullett, Brian K.; Tabor, Dennis; Yonker, Nick

2017-02-01

Emissions from burning piles of post-harvest timber slash (Douglas-fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5), black carbon, ultraviolet absorbing PM, elemental/organic carbon, filter-based metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins/dibenzofurans (PCDD/PCDF), and volatile organic compounds (VOCs) were sampled to determine emission factors, the amount of pollutant formed per amount of biomass burned. The effect on emissions from covering the piles with polyethylene (PE) sheets to prevent fuel wetting versus uncovered piles was also determined. Results showed that the uncovered ("wet") piles burned with lower combustion efficiency and higher emission factors for VOCs, PM2.5, PCDD/PCDF, and PAHs. Removal of the PE prior to ignition, variation of PE size, and changing PE thickness resulted in no statistical distinction between emissions. Results suggest that dry piles, whether covered with PE or not, exhibited statistically significant lower emissions than wet piles due to better combustion efficiency.

Signal identification in acoustic emission monitoring of fatigue cracking in steel bridges

NASA Astrophysics Data System (ADS)

Yu, Jianguo P.; Ziehl, Paul; Pollock, Adrian

2012-04-01

Signal identification including noise filtering and reduction of acquired signals is needed to achieve efficient and accurate data interpretation for remote acoustic emission (AE) monitoring of in-service steel bridges. Noise filtering may ensure that genuine hits from crack growth are involved in the estimation of fatigue damage and remaining fatigue life. Reduction of the data quantity is desirable for the sensing system to conserve energy in the data transmission and processing procedures. Identification and categorization of acquired signals is a promising approach to effectively filter and reduce AE data in the application of bridge monitoring. In this study an investigation on waveform features (time domain and frequency domain) and relevant filters is carried out using the results from AE monitored fatigue tests. It is verified that duration-amplitude (D-A) filters are effective to discriminate against noise for results of steel fatigue tests. The study is helpful to find an appropriate AE data filtering protocol for field implementations.

CHARACTERIZATION OF EMISSIONS FROM BURNING INCENSE

EPA Science Inventory

The primary objective of this study was to improve the characterization of particulate matter emissions from burning incense. Emissions of particulate matter were measured for 23 different types of incense using a cyclone/filter method. Emission rates for PM2.5 (particulate matte...

Differences between emissions measured in urban driving and certification testing of heavy-duty diesel engines

NASA Astrophysics Data System (ADS)

Dixit, Poornima; Miller, J. Wayne; Cocker, David R.; Oshinuga, Adewale; Jiang, Yu; Durbin, Thomas D.; Johnson, Kent C.

2017-10-01

Emissions from eight heavy-duty diesel trucks (HDDTs) equipped with three different exhaust aftertreatment systems (ATS) for controlling nitrogen oxide (NOx) emissions were quantified on a chassis dynamometer using driving schedules representative of stop-and-go and free-flow driving in metropolitan areas. The three control technologies were: 1) cooled exhaust gas recirculation (CEGR) plus a diesel particulate filter (DPF); 2) CEGR and DPF plus advanced engine controls; and 3) CEGR and DPF plus selective catalytic reduction with ammonia (SCR). Results for all control technologies and driving conditions showed PM emission factors were less than the standard, while selected non-regulated emissions (ammonia, carbonyls, and C4-C12 hydrocarbons) and a greenhouse gas (nitrous oxide) were at measurement detection limits. However, NOx emission factors depended on the control technology, engine calibration, and driving mode. For example, emissions from engines with cooled-exhaust gas recirculation (CEGR) were 239% higher for stop-and-go driving as compared with free-flow. For CEGR plus selective catalytic reduction (SCR), the ratio was 450%. A deeper analysis was carried out with the assumption that emissions measured for a drive cycle on either the chassis or in-use driving would be similar. Applying the same NTE rules to the chassis data showed emissions during stop-and-go driving often exceeded the certification standard and >90% of the driving did not fall within the Not-To-Exceed (NTE) control area suggesting the NTE requirements do not provide sufficient emissions control under in-use conditions. On-road measurement of emissions using the same mobile lab while the vehicle followed a free-flow driving schedule verified the chassis results. These results have implications for scientists who build inventories using certification values instead of real world emission values and for metropolitan populations, who are exposed to elevated emissions. The differences in values between real world emissions and certification cycles should be narrowed. For example, one might use a different mix of cold and hot start testing to greater emphasize low temperature/load operation, a separate cycle to specifically characterize low-load operation, or broaden the in-use compliance testing requirements and associated conformity factors to incorporate a wider envelope of vehicle operation, especially at low load conditions. .

Light trapping for emission from a photovoltaic cell under normally incident monochromatic illumination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeda, Yasuhiko, E-mail: takeda@mosk.tytlabs.co.jp; Iizuka, Hideo; Mizuno, Shintaro

2014-09-28

We have theoretically demonstrated a new light-trapping mechanism to reduce emission from a photovoltaic (PV) cell used for a monochromatic light source, which improves limiting conversion efficiency determined by the detailed balance. A multilayered bandpass filter formed on the surface of a PV cell has been found to prevent the light generated inside by radiative recombination from escaping the cell, resulting in a remarkable decrease of the effective solid angle for the emission. We have clarified a guide to design a suitable configuration of the bandpass filter and achieved significant reduction of the emission. The resultant gain in monochromatic conversionmore » efficiency in the radiative limit due to the optimally designed 18-layerd bandpass filters is as high as 6% under normally incident 1064 nm illumination of 10 mW/cm²~ 1 kW/cm², compared with the efficiency for the perfect anti-reflection treatment to the surface of a conventional solar cell.« less

High performance incandescent lighting using a selective emitter and nanophotonic filters

NASA Astrophysics Data System (ADS)

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle; Ilic, Ognjen; Soljačić, Marin; Wang, Evelyn N.

2017-09-01

Previous approaches for improving the efficiency of incandescent light bulbs (ILBs) have relied on tailoring the emitted spectrum using cold-side interference filters that reflect the infrared energy back to the emitter while transmitting the visible light. While this approach has, in theory, potential to surpass light-emitting diodes (LEDs) in terms of luminous efficiency while conserving the excellent color rendering index (CRI) inherent to ILBs, challenges such as low view factor between the emitter and filter, high emitter (>2800 K) and filter temperatures and emitter evaporation have significantly limited the maximum efficiency. In this work, we first analyze the effect of non-idealities in the cold-side filter, the emitter and the view factor on the luminous efficiency. Second, we theoretically and experimentally demonstrate that the loss in efficiency associated with low view factors can be minimized by using a selective emitter (e.g., high emissivity in the visible and low emissivity in the infrared) with a filter. Finally, we discuss the challenges in achieving a high performance and long-lasting incandescent light source including the emitter and filter thermal stability as well as emitter evaporation.

Io's Sodium Cloud (Clear Filter and Green-Yellow Filter with Intensity Contours)

NASA Technical Reports Server (NTRS)

1997-01-01

This picture contains two images of Jupiter's moon Io and its surrounding sky. The original frame was exposed twice, once through a clear filter and once through a green-yellow filter. The camera pointed in slightly different directions for the two exposures, placing a clear filter image of Io in the top half of the frame, and a green-yellow filter image of Io in the bottom half of the frame. This picture shows the entire original frame with the addition of intensity contours and false color. East is to the right.

Most of Io's visible surface is in shadow, though part of a white crescent can be seen on its western side. This crescent is being illuminated mostly by 'Jupitershine' (i.e., sunlight reflected off Jupiter). Near Io's eastern equatorial edge is a burst of white light which shows up best in the lower image. This sunlight being scattered by the plume of the volcano Prometheus. Prometheus lies just beyond the visible edge of the moon on Io's far side. Its plume extends about 100 kilometers above the surface, and is being hit by sunlight just a little east of Io's eastern edge.

The sky is full of diffuse light, some of which is scattered light from Prometheus' plume and Io's lit crescent (particularly in the half of the frame dominated by the clear filter). However, much of the diffuse emission comes from Io's Sodium Cloud: sodium atoms within Io's extensive material halo are scattering sunlight into both the clear and green-yellow filters at a wavelength of about 589 nanometers.

The intensity contours help to illustrate that: (i) significant diffuse emission is present all the way to the eastern edge of the frame (indeed, the Sodium Cloud is known to extend far beyond that edge); (ii) the diffuse emission exhibits a directional feature at about four o'clock relative to Io's center (similar features have been seen in the Sodium Cloud at greater distances from Io).

The upper image of Io exhibits a roundish white spot in the bottom half of Io's shadowed side. This corresponds to thermal emission from the volcano Pele. The lower image bears a much smaller trace of this emission because the clear filter is far more sensitive than the green-yellow filter to those relatively long wavelengths where thermal emission is strongest.

This image was taken at 5 hours 30 minutes Universal Time on Nov. 9, 1996 by the solid state imaging (CCD) system aboard NASA's Galileo spacecraft. Galileo was then in Jupiter's shadow, and located about 2.3 million kilometers (about 32 Jovian radii) from both Jupiter and Io.

The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at: http://galileo.jpl.nasa.gov.

Results from Evaluation of Proposed ASME AG-1 Section FI Metal Media Filters - 13063

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, John A.; Giffin, Paxton K.; Parsons, Michael S.

High efficiency particulate air (HEPA) filtration technology is commonly used in Department of Energy (DOE) facilities that require control of radioactive particulate matter (PM) emissions due to treatment or management of radioactive materials. Although HEPA technology typically makes use of glass fiber media, metal and ceramic media filters are also capable of filtering efficiencies beyond the required 99.97%. Sintered metal fiber filters are good candidates for use in DOE facilities due to their resistance to corrosive environments and resilience at high temperature and elevated levels of relative humidity. Their strength can protect them from high differential pressure or pressure spikesmore » and allow for back pulse cleaning, extending filter lifetime. Use of these filters has the potential to reduce the cost of filtration in DOE facilities due to life cycle cost savings. ASME AG-1 section FI has not been approved due to a lack of protocols and performance criteria for qualifying section FI filters. The Institute for Clean Energy Technology (ICET) with the aid of the FI project team has developed a Section FI test stand and test plan capable of assisting in the qualification ASME AG-1 section FI filters. Testing done at ICET using the FI test stand evaluates resistance to rated air flow, test aerosol penetration and resistance to heated air of the section FI filters. Data collected during this testing consists of temperature, relative humidity, differential pressure, flow rate, upstream particle concentration, and downstream particle concentration. (authors)« less

The effects of emission control strategies on light-absorbing carbon emissions from a modern heavy-duty diesel engine.

PubMed

Robinson, Michael A; Olson, Michael R; Liu, Z Gerald; Schauer, James J

2015-06-01

Control of atmospheric black carbon (BC) and brown carbon (BrC) has been proposed as an important pathway to climate change mitigation, but sources of BC and BrC are still not well understood. In order to better identify the role of modern heavy-duty diesel engines on the production of BC and BrC, emissions from a heavy-duty diesel engine operating with different emission control strategies were examined using a source dilution sampling system. The effect of a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) on light-absorbing carbon (LAC) was evaluated at three steady-state engine operation modes: idle, 50% speed and load, and 100% speed and load. LAC was measured with four different engine configurations: engine out, DOC out, DPF out, and engine out with an altered combustion calibration. BC and BrC emission rates were measured with the Aethalometer (AE-31). EC and BC emission rates normalized to the mass of CO₂emitted increased with increasing engine speed and load. Emission rates normalized to brake-specific work did not exhibit similar trends with speed and load, but rather the highest emission rate was measured at idle. EC and OC emissions were reduced by 99% when the DOC and DPF architecture was applied. The application of a DPF was equally effective at removing 99% of the BC fraction of PM, proving to be an important control strategy for both LAC and PM. BC emissions were unexpectedly increased across the DOC, seemingly due to a change aerosol optical properties. Removal of exhaust gas recirculation (EGR) flow due to simulated EGR cooler failure caused a large increase in OC and BrC emission rates at idle, but had limited influence during high load operation. LAC emissions proved to be sensitive to the same control strategies effective at controlling the total mass of diesel PM. In the context of black carbon emissions, very small emission rates of brown carbon were measured over a range of control technologies and engine operating conditions. During specific idle engine operation without EGR and adjusted fueling conditions, brown carbon can be formed in significant amounts, requiring careful management tactics. Control technologies for particulate matter are very effective for light-absorbing carbon, reducing black carbon emissions to near zero for modern engines equipped with a DPF. Efforts to control atmospheric brown carbon need to focus on other sources other than modern diesel engines, such as biomass burning.

Early Observations with the ACS Ramp Filters

NASA Astrophysics Data System (ADS)

Tsvetanov, Z.; Hartig, G.; Bohlin, R.; Tran, H. D.; Martel, A.; Sirianni, M.; Clampin, M.

2002-05-01

The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with a set of ramp filters which provide imaging capability at 2% and 9% bandwidth in the range 3700-10700 Å. Each ramp filter consist of three segments where the middle segment can be used with both the Wide Field Channel (WFC) and High Resolution Channel (HRC), while the inner and outer segments can be used only with WFC. The monochromatic field of view is approximately 40'' by 80''. We will present observations of the planetary nebula (PN) NGC6543 (the Cat's Eye) taken with the ACS ramp filetrs in several key emission lines - [O II] 3727, [O III] 5007, H-alpha+[N II], and [S II] 6725. These four emission lines fall onto three separate middle ramp segments - FR388N, FR505N, and FR656N - and will allow inter-comparison between the ACS ramp filters and fixed bandpass narrow-band filters F502N and F658N for both the WFC and HRC detectors. These observations were taken as part of the HST Servicing Mission Orbital Verification program and were designed to test ramp filters performance. We will demostrate our ability to obtain monochromatic (i.e., emission line) images at arbitrary wavelength and recover the surface brightness distribution. This work was supported by a NASA contract and a NASA grant.

Evaluation of Eye Protection Filters Used with Broad-Spectrum and Conventional LED Curing Lights.

PubMed

Soares, Carlos José; Rodrigues, Monise de Paula; Vilela, Andomar Bruno Fernandes; Rizo, Erick René Cerda; Ferreira, Lorraine Braga; Giannini, Marcelo; Price, Richard Bengt

2017-01-01

The high irradiance and the different emission spectra from contemporary light curing units (LCU) may cause ocular damage. This study evaluated the ability of 15 eye protection filters: 2 glasses, 1 paddle design, and 12 dedicated filters to block out harmful light from a monowave (HP-3M ESPE) and a broad-spectrum (Valo, Ultradent) LED LCU. Using the anterior sensor in the MARC-Patient Simulator (BlueLight Analytics) the irradiance that was delivered through different eye protection filters was measured three times. The LCUs delivered a similar irradiance to the top of the filter. The mean values of the light that passed through the filters as percent of the original irradiance were analyzed using two-way ANOVA followed by Tukey test (a= 0.05). The emission spectra from the LCUs and through the filters were also obtained. Two-way ANOVA showed that the interaction between protective filters and LCUs significantly influenced the amount of light transmitted (p< 0.001). Tukey test showed that the amount of light transmitted through the protective filters when using the HP-3M-ESPE was significantly greater compared to when using the Valo, irrespective of the protective filter tested. When using the HP-3M-ESPE, the Glasses filter allowed significantly more light through, followed by XL 3000, ORTUS, Google Professional, Gnatus filters. The Valo filter was the most effective at blocking out the harmful light. Some protective filters were less effective at blocking the lower wavelengths of light (<420 nm). However, even in the worst scenario, the filters were able to block at least 97% of the irradiance.

Effects of Aftermarket Control Technologies on Gas and ...

EPA Pesticide Factsheets

Particulate matter (PM) originating from diesel combustion is a public health concern due to its association with adverse effects on respiratory and cardiovascular diseases and lung cancer. This study investigated emissions from three stationary diesel engines (gensets) with varying power output (230 kW, 400 kW, and 600 kW) at 50% and 90% load to determine concentrations of gaseous (GROS) and PM reactive oxygen species (PMROS). In addition, the influence of three modern emission control technologies on ROS emissions was evaluated: active and passive diesel particulate filters (A-DPF and P-DPF) and a diesel oxidation catalyst (DOC). PMROS made up 30-50% of the total ROS measured without aftermarket controls. All applied controls removed PMROS by more than 75% on average. However, the oxidative potential of PM downstream of these devices was not diminished at the same rate and particles surviving the A-PDF had an even higher oxidative potential on a per PM mass basis compared to the particles emitted by uncontrolled gensets. Further, the GROS as compared to PMROS emissions were not reduced with the same efficiency (<36%). GROS concentrations were highest with the DOC in use, indicating continued formation of GROS with this control. Correlation analyses showed that PMROS and to a lesser extent GROS have a good correlation with semi-volatile organic carbon (OC1) sub-fraction. In addition, results suggest that chemical composition, rather than PM size, is re

Biodiesel Performance with Modern Engines. Cooperative Research and Development Final Report, CRADA Number CRD-05-153

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, Robert

NREL and the National Biodiesel Board (NBB) will work cooperatively to assess the effects of biodiesel blends on the performance of modern diesel engines and emissions control systems meeting increasingly strict emissions standards. This work will include research to understand the impact of biodiesel blends on the operation and durability of particle filters and NOx control sorbents/catalysts, to quantify the effect on emission control systems performance, and to understand effects on engine component durability. Work to assess the impact of biodiesel blends on real world fleet operations will be performed. Also, research to develop appropriate ASTM standards for biodiesel qualitymore » and stability will be conducted. The cooperative project will involve engine testing and fleet evaluation studies at NREL using biodiesel from a variety of sources. In addition, NREL will work with NBB to set up an Industrial Steering Committee to design the scope for the various projects and to provide technical oversight to these projects. NREL and NBB will cooperatively communicate the study results to as broad an audience as possible.« less

Remote monitoring and prognosis of fatigue cracking in steel bridges with acoustic emission

NASA Astrophysics Data System (ADS)

Yu, Jianguo Peter; Ziehl, Paul; Pollock, Adrian

2011-04-01

Acoustic emission (AE) monitoring is desirable to nondestructively detect fatigue damage in steel bridges. Investigations of the relationship between AE signals and crack growth behavior are of paramount importance prior to the widespread application of passive piezoelectric sensing for monitoring of fatigue crack propagation in steel bridges. Tests have been performed to detect AE from fatigue cracks in A572G50 steel. Noise induced AE signals were filtered based on friction emission tests, loading pattern, and a combined approach involving Swansong II filters and investigation of waveforms. The filtering methods based on friction emission tests and load pattern are of interest to the field evaluation using sparse datasets. The combined approach is suitable for data filtering and interpretation of actual field tests. The pattern recognition program NOESIS (Envirocoustics) was utilized for the evaluation of AE data quality. AE parameters are associated with crack length, crack growth rate, maximum stress intensity and stress intensity range. It is shown that AE hits, counts, absolute energy, and signal strength are able to provide warnings at the critical cracking level where cracking progresses from stage II (stable propagation) to stage III (unstable propagation which may result in failure). Absolute energy rate and signal strength rate may be better than count rate to assess the remaining fatigue life of inservice steel bridges.

Treatment of suspended solids and heavy metals from urban stormwater runoff by a tree box filter.

PubMed

Geronimo, F K F; Maniquiz-Redillas, M C; Tobio, J A S; Kim, L H

2014-01-01

Particulates, inorganic and toxic constituents are the most common pollutants associated with urban stormwater runoff. Heavy metals such as chromium, nickel, copper, zinc, cadmium and lead are found to be in high concentration on paved roads or parking lots due to vehicle emissions. In order to control the rapid increase of pollutant loads in stormwater runoff, the Korean Ministry of Environment proposed the utilization of low impact developments. One of these was the application of tree box filters that act as a bioretention treatment system which executes filtration and sorption processes. In this study, a tree box filter located adjacent to an impervious parking lot was developed to treat suspended solids and heavy metal concentrations from urban stormwater runoff. In total, 11 storm events were monitored from July 2010 to August 2012. The results showed that the tree box filter was highly effective in removing particulates (up to 95%) and heavy metals (at least 70%) from the urban stormwater runoff. Furthermore, the tree box filter was capable of reducing the volume runoff by 40% at a hydraulic loading rate of 1 m/day and below.

Narrow-band filters for the lightning imager

NASA Astrophysics Data System (ADS)

Piegari, Angela; Di Sarcina, Ilaria; Grilli, Maria Luisa; Menchini, Francesca; Scaglione, Salvatore; Sytchkova, Anna; Zola, Danilo; Cuevas, Leticia P.

2017-11-01

The study of lightning phenomena will be carried out by a dedicated instrument, the lightning imager, that will make use of narrow-band transmission filters for separating the Oxygen emission lines in the clouds, from the background signal. The design, manufacturing and testing of these optical filters will be described here.

Raman Laser Spectrometer internal Optical Head current status: opto-mechanical redesign to minimize the excitation laser trace

NASA Astrophysics Data System (ADS)

Sanz, Miguel; Ramos, Gonzalo; Moral, Andoni; Pérez, Carlos; Belenguer, Tomás; del Rosario Canchal, María; Zuluaga, Pablo; Rodriguez, Jose Antonio; Santiago, Amaia; Rull, Fernando; Instituto Nacional de Técnica Aeroespacial (INTA); Ingeniería de Sistemas para la Defesa de España S.A. (ISDEFE)

2016-10-01

Raman Laser Spectrometer (RLS) is the Pasteur Payload instruments of the ExoMars mission, within the ESA's Aurora Exploration Programme, that will perform for the first time in an out planetary mission Raman spectroscopy. RLS is composed by SPU (Spectrometer Unit), iOH (Internal Optical Head), and ICEU (Instrument Control and Excitation Unit). iOH focuses the excitation laser on the samples (excitation path), and collects the Raman emission from the sample (collection path, composed on collimation system and filtering system). The original design presented a high laser trace reaching to the detector, and although a certain level of laser trace was required for calibration purposes, the high level degrades the Signal to Noise Ratio confounding some Raman peaks.The investigation revealing that the laser trace was not properly filtered as well as the iOH opto-mechanical redesign are reported on. After the study of the Long Pass Filters Optical Density (OD) as a function of the filtering stage to the detector distance, a new set of filters (Notch filters) was decided to be evaluated. Finally, and in order to minimize the laser trace, a new collection path design (mainly consisting on that the collimation and filtering stages are now separated in two barrels, and on the kind of filters to be used) was required. Distance between filters and collimation stage first lens was increased, increasing the OD. With this new design and using two Notch filters, the laser trace was reduced to assumable values, as can be observed in the functional test comparison also reported on this paper.

Compact characterization of liquid absorption and emission spectra using linear variable filters integrated with a CMOS imaging camera.

PubMed

Wan, Yuhang; Carlson, John A; Kesler, Benjamin A; Peng, Wang; Su, Patrick; Al-Mulla, Saoud A; Lim, Sung Jun; Smith, Andrew M; Dallesasse, John M; Cunningham, Brian T

2016-07-08

A compact analysis platform for detecting liquid absorption and emission spectra using a set of optical linear variable filters atop a CMOS image sensor is presented. The working spectral range of the analysis platform can be extended without a reduction in spectral resolution by utilizing multiple linear variable filters with different wavelength ranges on the same CMOS sensor. With optical setup reconfiguration, its capability to measure both absorption and fluorescence emission is demonstrated. Quantitative detection of fluorescence emission down to 0.28 nM for quantum dot dispersions and 32 ng/mL for near-infrared dyes has been demonstrated on a single platform over a wide spectral range, as well as an absorption-based water quality test, showing the versatility of the system across liquid solutions for different emission and absorption bands. Comparison with a commercially available portable spectrometer and an optical spectrum analyzer shows our system has an improved signal-to-noise ratio and acceptable spectral resolution for discrimination of emission spectra, and characterization of colored liquid's absorption characteristics generated by common biomolecular assays. This simple, compact, and versatile analysis platform demonstrates a path towards an integrated optical device that can be utilized for a wide variety of applications in point-of-use testing and point-of-care diagnostics.

Excitation-scanning hyperspectral imaging microscope

PubMed Central

Favreau, Peter F.; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F.; Rich, Thomas C.; Prabhat, Prashant; Leavesley, Silas J.

2014-01-01

Abstract. Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications. PMID:24727909

Excitation-scanning hyperspectral imaging microscope.

PubMed

Favreau, Peter F; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F; Rich, Thomas C; Prabhat, Prashant; Leavesley, Silas J

2014-04-01

Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications.

Emissions of polycyclic aromatic hydrocarbons from batch hot mix asphalt plants.

PubMed

Lee, Wen-Jhy; Chao, Wen-Hui; Shih, Minliang; Tsai, Cheng-Hsien; Chen, Thomas Jeng-Ho; Tsai, Perng-Jy

2004-10-15

This study was set out to assess the characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from batch hot mix asphalt (HMA) plants and PAH removal efficiencies associated with their installed air pollution control devices. Field samplings were conducted on six randomly selected batch HMA plants. For each selected plant, stack flue gas samples were collected from both stacks of the batch mixer (n = 5) and the preheating boiler (n = 5), respectively. PAH samples were also collected from the field to assess PAHs that were directly emitted from the discharging chute (n = 3). To assess PAH removal efficiencies of the installed air pollution control devices, PAH contents in both cyclone fly ash (n=3) and bag filter fly ash (n = 3) were analyzed. Results show that the total PAH concentration (mean; RSD) in the stack flue gas of the batch mixer (354 microg/Nm3; 78.5%) was higher than that emitted from the discharging chute (107 microg/Nm3; 70.1%) and that in the stack flue gas of the preheating boiler (83.7 microg/Nm3; 77.6%). But the total BaPeq concentration of that emitted from the discharging chute (0.950 microg/Nm3; 84.4%) was higher than contained in the stack flue gas of the batch mixer (0.629 microg/Nm3; 86.8%) and the stack flue gas of the preheating boiler (= 0.112 microg/Nm3; 80.3%). The mean total PAH emission factor for all selected batch mix plants (= 139 mg/ton x product) was much higher than that reported by U.S. EPA for the drum mix asphalt plant (range = 11.8-79.0 mg/ton x product). We found the overall removal efficiency of the installed air pollution control devices (i.e., cyclone + bag filter) on total PAHs and total BaPeq were 22.1% and 93.7%, respectively. This implies that the installed air pollution control devices, although they have a very limited effect on the removal of total PAHs, do significantly reduce the carcinogenic potencies associated with PAH emissions from batch HMA plants.

Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rathore, Kavita, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Munshi, Prabhat, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Bhattacharjee, Sudeep, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in

A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actualmore » processes. This paper presents development of a compact, modular, and versatile Optical Emission Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal–oxide–semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission H{sub α} (656 nm) and H{sub β} (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.« less

Effects of After-Treatment Control Technologies on Heavy-Duty Diesel Truck Emissions

NASA Astrophysics Data System (ADS)

Preble, C.; Dallmann, T. R.; Kreisberg, N. M.; Hering, S. V.; Harley, R.; Kirchstetter, T.

2015-12-01

Diesel engines are major emitters of nitrogen oxides (NOx) and the black carbon (BC) fraction of particulate matter (PM). Diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems that target exhaust PM and NOx have recently become standard on new heavy-duty diesel trucks (HDDT). There is concern that DPFs may increase ultrafine particle (UFP) and total particle number (PN) emissions while reducing PM mass emissions. Also, the deliberate catalytic oxidation of engine-out NO to NO2 in continuously regenerating DPFs may lead to increased tailpipe emission of NO2 and near-roadway concentrations that exceed the 1-hr national ambient air quality standard. Increased NO2 emissions can also promote formation of ozone and secondary PM. We report results from ongoing on-road studies of HDDT emissions at the Port of Oakland and the Caldecott Tunnel in California's San Francisco Bay Area. Emission factors (g pollutant per kg diesel) were linked via recorded license plates to each truck's engine model year and installed emission controls. At both sites, DPF use significantly increased the NO2/NOx emission ratio. DPFs also significantly increased NO2 emissions when installed as retrofits on older trucks with higher baseline NOx emissions. While SCR systems on new trucks effectively reduce total NOx emissions and mitigate these undesirable DPF-related NO2 emissions, they also lead to significant emission of N2O, a potent greenhouse gas. When expressed on a CO2-equivalent basis, the N2O emissions increase offsets the fuel economy gain (i.e., the CO2 emission reduction) associated with SCR use. At the Port, average NOx, BC and PN emission factors from new trucks equipped with DPF and SCR were 69 ± 15%, 92 ± 32% and 66 ± 35% lower, respectively, than modern trucks without these emission controls. In contrast, at the Tunnel, PN emissions from older trucks retrofit with DPFs were ~2 times greater than modern trucks without DPFs. The difference could be related to engine temperature, with highway operation producing greater exhaust temperatures that promote UFP nucleation. These studies indicate that DPF and SCR use can mitigate air quality and climate impacts of diesel truck emissions through reductions in BC and NOx. However, increased emissions of N2O, NO2 and PN may offset some of the benefits.

Time Domain Filtering of Resolved Images of Sgr A{sup ∗}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiokawa, Hotaka; Doeleman, Sheperd S.; Gammie, Charles F.

The goal of the Event Horizon Telescope (EHT) is to provide spatially resolved images of Sgr A*, the source associated with the Galactic Center black hole. Because Sgr A* varies on timescales that are short compared to an EHT observing campaign, it is interesting to ask whether variability contains information about the structure and dynamics of the accretion flow. In this paper, we introduce “time-domain filtering,” a technique to filter time fluctuating images with specific temporal frequency ranges and to demonstrate the power and usage of the technique by applying it to mock millimeter wavelength images of Sgr A*. Themore » mock image data is generated from the General Relativistic Magnetohydrodynamic (GRMHD) simulation and the general relativistic ray-tracing method. We show that the variability on each line of sight is tightly correlated with a typical radius of emission. This is because disk emissivity fluctuates on a timescale of the order of the local orbital period. Time-domain filtered images therefore reflect the model dependent emission radius distribution, which is not accessible in time-averaged images. We show that, in principle, filtered data have the power to distinguish between models with different black-hole spins, different disk viewing angles, and different disk orientations in the sky.« less

Time Domain Filtering of Resolved Images of Sgr A∗

NASA Astrophysics Data System (ADS)

Shiokawa, Hotaka; Gammie, Charles F.; Doeleman, Sheperd S.

2017-09-01

The goal of the Event Horizon Telescope (EHT) is to provide spatially resolved images of Sgr A*, the source associated with the Galactic Center black hole. Because Sgr A* varies on timescales that are short compared to an EHT observing campaign, it is interesting to ask whether variability contains information about the structure and dynamics of the accretion flow. In this paper, we introduce “time-domain filtering,” a technique to filter time fluctuating images with specific temporal frequency ranges and to demonstrate the power and usage of the technique by applying it to mock millimeter wavelength images of Sgr A*. The mock image data is generated from the General Relativistic Magnetohydrodynamic (GRMHD) simulation and the general relativistic ray-tracing method. We show that the variability on each line of sight is tightly correlated with a typical radius of emission. This is because disk emissivity fluctuates on a timescale of the order of the local orbital period. Time-domain filtered images therefore reflect the model dependent emission radius distribution, which is not accessible in time-averaged images. We show that, in principle, filtered data have the power to distinguish between models with different black-hole spins, different disk viewing angles, and different disk orientations in the sky.

Economic analysis of atmospheric mercury emission control for coal-fired power plants in China.

PubMed

Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy; Hao, Jiming

2015-07-01

Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. Copyright © 2015. Published by Elsevier B.V.

Determining the Differential Emission Measure from EIS, XRT, and AIA

NASA Technical Reports Server (NTRS)

Winebarger, Amy R.; Warren, H.P.; Schmelz, J.

2010-01-01

This viewgraph presentation determines the Differential Emission Measure (DEM) from the EUV Imaging Spectrometer (EIS), X Ray Telescope (XRT), and Atmospheric Imaging Array (AIA). Common observations with Fe, Si, and Ca EIS lines are shown along with observations with Al-mesh, Ti-poly Al-thick and Be-thick XRT filters. Results from these observations are shown to determine what lines and filters are important to better constrain the hot component.

Tier 2 Intermediate Useful Life (50,000 Miles) and 4000 Mile Supplemental Federal Test Procedure (SFTP) Exhaust Emission Results for a NOx Adsorber and Diesel Particle Filter Equipped Light-Duty Diesel Vehicle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatur, M.; Tyrer, H.; Tomazic, D.

2005-01-01

Due to its high efficiency and superior durability the diesel engine is again becoming a prime candidate for future light-duty vehicle applications within the United States. While in Europe the overall diesel share exceeds 40%, the current diesel share in the U.S. is 1%. Despite the current situation and the very stringent Tier 2 emission standards, efforts are being made to introduce the diesel engine back into the U.S. market. In order to succeed, these vehicles have to comply with emissions standards over a 120,000 miles distance while maintaining their excellent fuel economy. The availability of technologies such as high-pressure,more » common-rail fuel systems, low-sulfur diesel fuel, NO{sub x} adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with the light-duty Tier 2 emission requirements. In support of this, the U.S. Department of Energy (DOE) has engaged in several test projects under the Advanced Petroleum Based Fuels - Diesel Emission Controls (APBF-DEC) activity. The primary technology being addressed by these projects are the sulfur tolerance and durability of the NAC/DPF system. The project investigated the performance of the emission control system and system desulphurization effects on regulated and unregulated emissions. Emissions measurements were conducted over the Federal Test Procedure (FTP), Supplemental Federal Test Procedure (SFTP), and the Highway Fuel Economy Test (HFET). Testing was conducted after the accumulation of 150 hours of engine operation calculated to be the equivalent of approximately 8,200 miles. For these evaluations three out of six of the FTP test cycles were within the 50,000-mile Tier 2 bin 5 emission standards (0.05 g/mi NO{sub x} and 0.01 g/mi PM). Emissions over the SC03 portion of the SFTP were within the 4,000-mile SFTP standards. The emission of NO{sub x}+NMHC exceeded the 4,000-mile standard over the US06 portion of the SFTP. Testing was also conducted after the accumulation of 1,000 hours of engine operation calculated to be the equivalent of approximately 50,000 miles. Recalibrated driveability maps resulted in more repeatable NOs{sub x} emissions from cycle to cycle. The NO{sub x} level was below the Tier 2 emission limits for 50,000 and 120,000 miles. NMHC emissions were found at a level outside the limit for 120,000 miles.« less

Diesel passenger car PM emissions: From Euro 1 to Euro 4 with particle filter

NASA Astrophysics Data System (ADS)

Tzamkiozis, Theodoros; Ntziachristos, Leonidas; Samaras, Zissis

2010-03-01

This paper examines the impact of the emission control and fuel technology development on the emissions of gaseous and, in particular, PM pollutants from diesel passenger cars. Three cars in five configurations in total were measured, and covered the range from Euro 1 to Euro 4 standards. The emission control ranged from no aftertreatment in the Euro 1 case, an oxidation catalyst in Euro 2, two oxidation catalysts and exhaust gas recirculation in Euro 3 and Euro 4, while a catalyzed diesel particle filter (DPF) fitted in the Euro 4 car led to a Euro 4 + DPF configuration. Both certification test and real-world driving cycles were employed. The results showed that CO and HC emissions were much lower than the emission standard over the hot-start real-world cycles. However, vehicle technologies from Euro 2 to Euro 4 exceeded the NOx and PM emission levels over at least one real-world cycle. The NOx emission level reached up to 3.6 times the certification level in case of the Euro 4 car. PM were up to 40% and 60% higher than certification level for the Euro 2 and Euro 3 cars, while the Euro 4 car emitted close or slightly below the certification level over the real-world driving cycles. PM mass reductions from Euro 1 to Euro 4 were associated with a relevant decrease in the total particle number, in particular over the certification test. This was not followed by a respective reduction in the solid particle number which remained rather constant between the four technologies at 0.86 × 10 14 km -1 (coefficient of variation 9%). As a result, the ratio of solid vs. total particle number ranged from ˜50% in Euro 1-100% in Euro 4. A significant reduction of more than three orders of magnitude in solid particle number is achieved with the introduction of the DPF. However, the potential for nucleation mode formation at high speed from the DPF car is an issue that needs to be considered in the over all assessment of its environmental benefit. Finally, comparison of the mobility and aerodynamic diameters of airborne particles led to fractal dimensions dropping from 2.60 (Euro 1) to 2.51 (Euro 4), denoting a more loose structure with improving technology.

Lessons learned in preparing method 29 filters for compliance testing audits.

PubMed

Martz, R F; McCartney, J E; Bursey, J T; Riley, C E

2000-01-01

Companies conducting compliance testing are required to analyze audit samples at the time they collect and analyze the stack samples if audit samples are available. Eastern Research Group (ERG) provides technical support to the EPA's Emission Measurements Center's Stationary Source Audit Program (SSAP) for developing, preparing, and distributing performance evaluation samples and audit materials. These audit samples are requested via the regulatory Agency and include spiked audit materials for EPA Method 29-Metals Emissions from Stationary Sources, as well as other methods. To provide appropriate audit materials to federal, state, tribal, and local governments, as well as agencies performing environmental activities and conducting emission compliance tests, ERG has recently performed testing of blank filter materials and preparation of spiked filters for EPA Method 29. For sampling stationary sources using an EPA Method 29 sampling train, the use of filters without organic binders containing less than 1.3 microg/in.2 of each of the metals to be measured is required. Risk Assessment testing imposes even stricter requirements for clean filter background levels. Three vendor sources of quartz fiber filters were evaluated for background contamination to ensure that audit samples would be prepared using filters with the lowest metal background levels. A procedure was developed to test new filters, and a cleaning procedure was evaluated to see if a greater level of cleanliness could be achieved using an acid rinse with new filters. Background levels for filters supplied by different vendors and within lots of filters from the same vendor showed a wide variation, confirmed through contact with several analytical laboratories that frequently perform EPA Method 29 analyses. It has been necessary to repeat more than one compliance test because of suspect metals background contamination levels. An acid cleaning step produced improvement in contamination level, but the difference was not significant for most of the Method 29 target metals. As a result of our studies, we conclude: Filters for Method 29 testing should be purchased in lots as large as possible. Testing firms should pre-screen new boxes and/or new lots of filters used for Method 29 testing. Random analysis of three filters (top, middle, bottom of the box) from a new box of vendor filters before allowing them to be used in field tests is a prudent approach. A box of filters from a given vendor should be screened, and filters from this screened box should be used both for testing and as field blanks in each test scenario to provide the level of quality assurance required for stationary source testing.

Development of reduction scenarios for criteria air pollutants emission in Tehran Traffic Sector, Iran.

PubMed

Mohammadiha, Amir; Malakooti, Hossein; Esfahanian, Vahid

2018-05-01

Transport-related pollution as the main source of air pollution must be reduced in Tehran mega-city. The performance of various developed scenarios including BAU (Business As Usual) as baseline scenario, ECV (Elimination of carburetor equipped Vehicle), NEM (New Energy Motorcycles), HES (Higher Emission Standard), VCR (Vehicle Catalyst Replacement), FQE (Fuel Quality Enhancement), DPF (Diesel Particulate Filter) and TSA (Total Scenarios Aggregation) are evaluated by International Vehicle Model up to 2028. In the short term, the ECV, VCR, and FQE scenarios provided high performance in CO, VOCs and NOx emissions control. Also FQE has an excellent effect on SOx emission reduction (86%) and DPF on PM emissions (20%). In the mid-term, the VCR, ECV, and FQE scenarios were presented desirable mean emission reduction on CO, VOCs, and NOx. Moreover, NOx emission reduction of DPF scenario is the most common (14%). Again FQE scenario proves to have great effect on SOx emission reduction in mid-term (86%), DPF and HES scenarios on PM (DPF: 49% and HES: 17%). Finally for the long term, VCR, ECV, FQE, and NEM scenarios were shown good performance in emission control on CO, VOCs and NOx. For SOx only FQE has a good effect in all time periods (FQE: 86%) and DPF and HES scenarios have the best effect on PM emission reduction respectively (DPF: 51% and HES: 27%) compared with BAU scenario. However, DPF scenario increases 12% SOx emission in long-term (2028). It can be generally concluded that VCR and ECV scenarios would achieve a significant reduction on gaseous pollutants emission except for SOx in general and FQE scenarios have desirable performance for all gaseous pollutants in the short term and also for SOx and VOCs in long term. In addition, the DPF and HES would be desirable scenario for emission control on PM in Tehran Traffic Sector. Copyright © 2017 Elsevier B.V. All rights reserved.

A simple energy filter for low energy electron microscopy/photoelectron emission microscopy instruments.

PubMed

Tromp, R M; Fujikawa, Y; Hannon, J B; Ellis, A W; Berghaus, A; Schaff, O

2009-08-05

Addition of an electron energy filter to low energy electron microscopy (LEEM) and photoelectron emission microscopy (PEEM) instruments greatly improves their analytical capabilities. However, such filters tend to be quite complex, both electron optically and mechanically. Here we describe a simple energy filter for the existing IBM LEEM/PEEM instrument, which is realized by adding a single scanning aperture slit to the objective transfer optics, without any further modifications to the microscope. This energy filter displays a very high energy resolution ΔE/E = 2 × 10(-5), and a non-isochromaticity of ∼0.5 eV/10 µm. The setup is capable of recording selected area electron energy spectra and angular distributions at 0.15 eV energy resolution, as well as energy filtered images with a 1.5 eV energy pass band at an estimated spatial resolution of ∼10 nm. We demonstrate the use of this energy filter in imaging and spectroscopy of surfaces using a laboratory-based He I (21.2 eV) light source, as well as imaging of Ag nanowires on Si(001) using the 4 eV energy loss Ag plasmon.

40 CFR 86.145-82 - Calculations; particulate emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., inside the dilution air filter box at EPA is very low. Pb will be assumed = 0, and background particulate.... 86.145-82 Section 86.145-82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... further defined in § 86.144. (3) P e = mass of particulate per test on the exhaust filter(s), grams. (4...

40 CFR 86.145-82 - Calculations; particulate emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., inside the dilution air filter box at EPA is very low. Pb will be assumed = 0, and background particulate.... 86.145-82 Section 86.145-82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... further defined in § 86.144. (3) P e = mass of particulate per test on the exhaust filter(s), grams. (4...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2011 CFR

2011-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2013 CFR

2013-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2012 CFR

2012-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

40 CFR 63.11468 - What are the monitoring requirements for new and existing sources?

Code of Federal Regulations, 2014 CFR

2014-07-01

... baghouse, including but not limited to air leaks, torn or broken bags or filter media, or any other...) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR...

Reducing emissions by using special air filters for internal combustion engines

NASA Astrophysics Data System (ADS)

Birtok-Băneasă, C.; Raţiu, S. A.; Alexa, V.; Crăciun, A. L.; Josan, A.; Budiul-Berghian, A.

2017-05-01

This paper presents the experimental methodology to carry out functional performance tests for an air filter with a particular design of its housing, generically named Super absorbing YXV „Air by Corneliu”, patented and homologated by the Romanian Automotive Registry, to which numerous prizes and medals were awarded at national and international innovations salons. The tests were carried out in the Internal Combustion Engines Laboratory, within the specialization “Road vehicles” belonging to the Faculty of Engineering Hunedoara, component of Politehnica University of Timisoara. The scope of the study is to optimise the air intake into the engine cylinders by reducing the gas-dynamic resistances caused by the air filter and, therefore, to achieve higher energy efficiency, i.e. fuel consumption reduction and engine performance increase. We present some comparative values of various operating parameters of the engine fitted, in the first measuring session, with the original filter, and then with the studied filter. The data collected shows a reduction in fuel consumption by using this type of filter, which leads to lower emissions.

Application of pattern recognition techniques to acousto-ultrasonic testing of Kevlar composite panels

NASA Astrophysics Data System (ADS)

Hinton, Yolanda L.

An acousto-ultrasonic evaluation of panels fabricated from woven Kevlar and PVB/phenolic resin is being conducted. The panels were fabricated with various simulated defects. They were examined by pulsing with one acoustic emission sensor, and detecting the signal with another sensor, on the same side of the panel at a fixed distance. The acoustic emission signals were filtered through high (400-600 KHz), low (100-300 KHz) and wide (100-1200 KHz) bandpass filters. Acoustic emission signal parameters, including amplitude, counts, rise time, duration, 'energy', rms, and counts to peak, were recorded. These were statistically analyzed to determine which of the AE parameters best characterize the simulated defects. The wideband filtered acoustic emission signal was also digitized and recorded for further processing. Seventy-one features of the signals in both the time and frequency domains were calculated and compared to determine which subset of these features uniquely characterize the defects in the panels. The objective of the program is to develop a database of AE signal parameters and features to be used in pattern recognition as an inspection tool for material fabricated from these materials.

Composition and Integrity of PAHs, Nitro-PAHs, Hopanes and Steranes In Diesel Exhaust Particulate Matter.

PubMed

Huang, Lei; Bohac, Stanislav V; Chernyak, Sergei M; Batterman, Stuart A

2013-08-01

Diesel exhaust particulate matter contains many semivolatile organic compounds (SVOCs) of environmental and health significance. This study investigates the composition, emission rates, and integrity of 25 SVOCs, including polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and diesel biomarkers hopanes and steranes. Diesel engine particulate matter (PM), generated using an engine test bench, three engine conditions, and ultra-low sulfur diesel (ULSD), was collected on borosilicate glass fiber filters. Under high engine load, the PM emission rate was 0.102 g/kWh, and emission rate of ΣPAHs (10 compounds), ΣNPAHs (6 compounds), Σhopanes (2 compounds), and Σsteranes (2 compounds) were 2.52, 0.351, 0.02 ~ 2 and 1μg/kWh, respectively. Storage losses were evaluated for three cases: conditioning filters in clean air at 25 °C and 33% relative humidity (RH) for 24 h; storing filter samples (without extraction) wrapped in aluminum foil at 4 °C for up to one month; and storing filter extracts in glass vials capped with Teflon crimp seals at 4 °C for up to six months. After conditioning filters for 24 h, 30% of the more volatile PAHs were lost, but lower volatility NPAHs, hopanes and steranes showed negligible changes. Storing wrapped filters and extracts at 4 °C for up to one month did not lead to significant losses, but storing extracts for five months led to significant losses of PAHs and NPAHs; hopanes and steranes demonstrated greater integrity. These results suggest that even relatively brief filter conditioning periods, needed for gravimetric measurements of PM mass, and extended storage of filter extracts can lead to underestimates of SVOC concentrations. Thus, SVOC sampling and analysis protocols should utilize stringent criteria and performance checks to identify and limit possible biases occurring during filter and extract processing.

Composition and Integrity of PAHs, Nitro-PAHs, Hopanes and Steranes In Diesel Exhaust Particulate Matter

PubMed Central

Huang, Lei; Bohac, Stanislav V.; Chernyak, Sergei M.; Batterman, Stuart A.

2013-01-01

Diesel exhaust particulate matter contains many semivolatile organic compounds (SVOCs) of environmental and health significance. This study investigates the composition, emission rates, and integrity of 25 SVOCs, including polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and diesel biomarkers hopanes and steranes. Diesel engine particulate matter (PM), generated using an engine test bench, three engine conditions, and ultra-low sulfur diesel (ULSD), was collected on borosilicate glass fiber filters. Under high engine load, the PM emission rate was 0.102 g/kWh, and emission rate of ΣPAHs (10 compounds), ΣNPAHs (6 compounds), Σhopanes (2 compounds), and Σsteranes (2 compounds) were 2.52, 0.351, 0.02 ~ 2 and 1μg/kWh, respectively. Storage losses were evaluated for three cases: conditioning filters in clean air at 25 °C and 33% relative humidity (RH) for 24 h; storing filter samples (without extraction) wrapped in aluminum foil at 4 °C for up to one month; and storing filter extracts in glass vials capped with Teflon crimp seals at 4 °C for up to six months. After conditioning filters for 24 h, 30% of the more volatile PAHs were lost, but lower volatility NPAHs, hopanes and steranes showed negligible changes. Storing wrapped filters and extracts at 4 °C for up to one month did not lead to significant losses, but storing extracts for five months led to significant losses of PAHs and NPAHs; hopanes and steranes demonstrated greater integrity. These results suggest that even relatively brief filter conditioning periods, needed for gravimetric measurements of PM mass, and extended storage of filter extracts can lead to underestimates of SVOC concentrations. Thus, SVOC sampling and analysis protocols should utilize stringent criteria and performance checks to identify and limit possible biases occurring during filter and extract processing. PMID:24363468

Transverse mode control in proton-implanted and oxide-confined VCSELs via patterned dielectric anti-phase filters

NASA Astrophysics Data System (ADS)

Kesler, Benjamin; O'Brien, Thomas; Dallesasse, John M.

2017-02-01

A novel method for controlling the transverse lasing modes in both proton implanted and oxide-confined vertical- cavity surface-emitting lasers (VCSELs) with a multi-layer, patterned, dielectric anti-phase (DAP) filter is pre- sented. Using a simple photolithographic liftoff process, dielectric layers are deposited and patterned on individual VCSELs to modify (increase or decrease) the mirror reflectivity across the emission aperture via anti-phase reflections, creating spatially-dependent threshold material gain. The shape of the dielectric pattern can be tailored to overlap with specific transverse VCSEL modes or subsets of transverse modes to either facilitate or inhibit lasing by decreasing or increasing, respectively, the threshold modal gain. A silicon dioxide (SiO2) and titanium dioxide (TiO2) anti-phase filter is used to achieve a single-fundamental-mode, continuous-wave output power greater than 4.0 mW in an oxide-confined VCSEL at a lasing wavelength of 850 nm. A filter consisting of SiO2 and TiO2 is used to facilitate injection-current-insensitive fundamental mode and lower order mode lasing in proton implanted VCSELs at a lasing wavelength of 850 nm. Higher refractive index dielectric materials such as amorphous silicon (a-Si) can be used to increase the effectiveness of the anti-phase filter on proton implanted devices by reducing the threshold modal gain of any spatially overlapping modes. This additive, non-destructive method allows for mode selection at any lasing wavelength and for any VCSEL layer structure without the need for semiconductor etching or epitaxial regrowth. It also offers the capability of designing a filter based upon available optical coating materials.

Evaluating the effects of China's pollution control on inter-annual trends and uncertainties of atmospheric mercury emissions

NASA Astrophysics Data System (ADS)

Zhao, Y.; Zhong, H.; Zhang, J.; Nielsen, C. P.

2014-10-01

China's atmospheric mercury (Hg) emissions of anthropogenic origin have been effectively restrained through the national policy of air pollution control. Improved methods based on available field measurements are developed to quantify the benefits of Hg abatement through various emission control measures. Those measures include increased use of flue gas desulfurization (FGD) and selective catalyst reduction (SCR) systems for power sector, precalciners with fabric filter (FF) for cement production, machinery coking with electrostatic precipitator (ESP) for iron and steel production, and advanced manufacturing technologies for nonferrous metal smelting. Declining trends in emissions factors for those sources are revealed, leading to a much slower growth of national total Hg emissions than that of energy and economy, from 679 in 2005 to 750 metric tons (t) in 2012. In particular, nearly half of emissions from the above-mentioned four types of sources are expected to be reduced in 2012, attributed to expansion of technologies with high energy efficiencies and air pollutant removal rates after 2005. The speciation of Hg emissions keeps stable for recent years, with the mass fractions of around 55, 39 and 6% for Hg0, Hg2+ and Hgp, respectively. The lower estimate of Hg emissions than previous inventories is supported by limited chemistry simulation work, but middle-to-long term observation on ambient Hg levels is further needed to justify the inter-annual trends of estimated Hg emissions. With improved implementation of emission controls and energy saving, 23% reduction in annual Hg emissions for the most optimistic case in 2030 is expected compared to 2012, with total emissions below 600 t. While Hg emissions are evaluated to be gradually constrained, increased uncertainties are quantified with Monte-Carlo simulation for recent years, particularly for power and certain industrial sources. The uncertainty of Hg emissions from coal-fired power plants, as an example, increased from -48~ +73% in 2005 to -50~ +89% in 2012 (expressed as 95% confidence interval). This is attributed mainly to swiftly increased penetration of advanced manufacturing and pollutant control technologies. The unclear operation status or relatively small sample size of field measurements on those technologies results in lower but highly varied emission factors. To further confirm the benefits of pollution control polices with reduced uncertainty, therefore, systematic investigations are recommended specific for Hg pollution sources, and the variability of temporal trends and spatial distributions of Hg emissions need to be better tracked for the country under dramatic changes in economy, energy and air pollution status.

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

40 CFR 90.407 - Engine inlet and exhaust systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine must...

Boiler Briquette Coal versus Raw Coal: Part I-Stack Gas Emissions.

PubMed

Ge, Su; Bai, Zhipeng; Liu, Weili; Zhu, Tan; Wang, Tongjian; Qing, Sheng; Zhang, Junfeng

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM 10 and PM 2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM 10 , 0.38 for PM 25 , 20.7 for SO 2 , and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM 10 , 0.30 for PM 2 5 , 7.5 for SO 2 , and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM 10 , 0.87 for PM 25 , 46.7 for SO 2 , and 15 for CO, while those of the BB-coal were 2.51 for PM 10 , 0.79 for PM 2.5 , 19.9 for SO 2 , and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/ steam conversion factors, were 0.23 for PM 10 , 0.12 for PM 2.5 , 6.4 for SO 2 , and 2.0 for CO, while those of the BB-coal were 0.30 for PM 10 , 0.094 for PM 2.5 , 2.4 for SO 2 , and 1.7 for CO. PM 10 and PM 2.5 elemental compositions are also presented for both types of coal tested in the study.

Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

PubMed

Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.

Development of Diesel Exhaust Aftertreatment System for Tier II Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, R. C.; Cole, A. S., Stroia, B. J.; Huang, S. C.

2002-06-01

Due to their excellent fuel efficiency, reliability, and durability, compression ignition direct injection (CIDI) engines have been used extensively to power almost all highway trucks, urban buses, off-road vehicles, marine carriers, and industrial equipment. CIDI engines burn 35 to 50% less fuel than gasoline engines of comparable size, and they emit far less greenhouse gases (Carbon Dioxides), which have been implicated in global warming. Although the emissions of CIDI engines have been reduced significantly over the last decade, there remains concern with the Nitrogen Oxides (NOX) and Particulate Matter (PM) emission levels. In 2000, the US EPA proposed very stringentmore » emissions standards to be introduced in 2007 along with low sulfur (< 15ppm) diesel fuel. The California Air Resource Board (CARB) has also established the principle that future diesel fueled vehicles should meet the same emissions standards as gasoline fueled vehicles and the EPA followed suit with its Tier II emissions regulations. Meeting the Tier II standards requires NOX and PM emissions to be reduced dramatically. Achieving such low emissions while minimizing fuel economy penalty cannot be done through engine development and fuel reformulation alone, and requires application of NOX and PM aftertreatment control devices. A joint effort was made between Cummins Inc. and the Department of Energy to develop the generic aftertreatment subsystem technologies applicable for Light-Duty Vehicle (LDV) and Light-Duty Truck (LDT) engines. This paper provides an update on the progress of this joint development program. Three NOX reduction technologies including plasmaassisted catalytic NOX reduction (PACR), active lean NOX catalyst (LNC), and adsorber catalyst (AC) technology using intermittent rich conditions for NOX reduction were investigated in parallel in an attempt to select the best NOX control approach for light-duty aftertreatment subsystem integration and development. Investigations included system design and analysis, critical lab/engine experiments, and ranking then selection of NOX control technologies against reliability, up-front cost, fuel economy, service interval/serviceability, and size/weight. The results of the investigations indicate that the best NOX control approach for LDV and LDT applications is a NOX adsorber system. A greater than 83% NOX reduction efficiency is required to achieve 0.07g/mile NOX Tier II vehicle-out emissions. Both active lean NOX and PACR technology are currently not capable of achieving the high conversion efficiency required for Tier II, Bin 5 emissions standards. In this paper, the NOX technology assessment and selection is first reviewed and discussed. Development of the selected NOX technology (NOX adsorber) and PM control are then discussed in more detail. Discussion includes exhaust sulfur management, further adsorber formulation development, reductant screening, diesel particulate filter development & active regeneration, and preliminary test results on the selected integrated SOX trap, NOX adsorber, and diesel particulate filter system over an FTP-75 emissions cycle, and its impact on fuel economy. Finally, the direction of future work for continued advanced aftertreatment technology development is discussed. (SAE Paper SAE-2002-01-1867 © 2002 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)« less

Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations

NASA Astrophysics Data System (ADS)

Llusià, J.; Peñuelas, J.; Gimeno, B. S.

Although certain factors controlling plant emission rates of volatile organic compounds (VOCs) are reasonably well understood, the influence of elevated ozone concentrations as abiotic stress is mostly unknown. Therefore, we studied the effects of ozone concentrations on seasonal biogenic volatile organic compound (BVOC) emissions by different Mediterranean plant species in open top chambers (OTC). Three ozone treatments were established: filtered air (F), non-filtered air (NF), and fumigated air (NF+) adding 40 nl l -1 of ozone over NF. We studied the response of VOC emission in saplings of four Mediterranean woody plant species and subspecies: Ceratonia siliqua L., Olea europaea L., Quercus ilex spp. ilex L., and Quercus ilex spp. rotundifolia L. as representative of natural Mediterranean vegetation. No visible symptoms were detected on the leaves. No significant effect was found on net photosynthetic rates or stomatal conductance except for an increase in net photosynthetic rates in Quercus ilex ilex in spring and summer and an overall slight increase in Quercus ilex rotundifolia. Emissions of the total VOCs from Ceratonia siliqua in summer, and from Olea europaea and Quercus ilex rotundifolia in spring increased in ozone fumigated OTC in comparison with F or NF OTC. Decreased emissions were found in Quercus ilex rotundifolia in summer. There were no significant differences between ozone fumigation treatments for the other plant species and seasons. When considering particular VOCs, the results were also variable among species and time of the year. While α-pinene emissions decreased with ozone fumigation in Olea europaea, α-pinene and limonene emissions increased in Quercus ilex ilex. The responses of these particular VOCs did not always match the responses of total VOCs. In spite of this strong variability, when considering overall annual data for all species and seasons, there were increased net photosynthetic rates (37%) and limonene (95%) and total VOC (45%) emission rates in ozone-fumigated plants, whereas stomatal conductance did not change. Since VOCs are precursors of ozone, the increase in BVOC emission as a consequence of elevated tropospheric ozone concentrations may lead to positive feedback mechanisms in ozone formation.

Compact characterization of liquid absorption and emission spectra using linear variable filters integrated with a CMOS imaging camera

PubMed Central

Wan, Yuhang; Carlson, John A.; Kesler, Benjamin A.; Peng, Wang; Su, Patrick; Al-Mulla, Saoud A.; Lim, Sung Jun; Smith, Andrew M.; Dallesasse, John M.; Cunningham, Brian T.

2016-01-01

A compact analysis platform for detecting liquid absorption and emission spectra using a set of optical linear variable filters atop a CMOS image sensor is presented. The working spectral range of the analysis platform can be extended without a reduction in spectral resolution by utilizing multiple linear variable filters with different wavelength ranges on the same CMOS sensor. With optical setup reconfiguration, its capability to measure both absorption and fluorescence emission is demonstrated. Quantitative detection of fluorescence emission down to 0.28 nM for quantum dot dispersions and 32 ng/mL for near-infrared dyes has been demonstrated on a single platform over a wide spectral range, as well as an absorption-based water quality test, showing the versatility of the system across liquid solutions for different emission and absorption bands. Comparison with a commercially available portable spectrometer and an optical spectrum analyzer shows our system has an improved signal-to-noise ratio and acceptable spectral resolution for discrimination of emission spectra, and characterization of colored liquid’s absorption characteristics generated by common biomolecular assays. This simple, compact, and versatile analysis platform demonstrates a path towards an integrated optical device that can be utilized for a wide variety of applications in point-of-use testing and point-of-care diagnostics. PMID:27389070

Compact characterization of liquid absorption and emission spectra using linear variable filters integrated with a CMOS imaging camera

NASA Astrophysics Data System (ADS)

Wan, Yuhang; Carlson, John A.; Kesler, Benjamin A.; Peng, Wang; Su, Patrick; Al-Mulla, Saoud A.; Lim, Sung Jun; Smith, Andrew M.; Dallesasse, John M.; Cunningham, Brian T.

2016-07-01

A compact analysis platform for detecting liquid absorption and emission spectra using a set of optical linear variable filters atop a CMOS image sensor is presented. The working spectral range of the analysis platform can be extended without a reduction in spectral resolution by utilizing multiple linear variable filters with different wavelength ranges on the same CMOS sensor. With optical setup reconfiguration, its capability to measure both absorption and fluorescence emission is demonstrated. Quantitative detection of fluorescence emission down to 0.28 nM for quantum dot dispersions and 32 ng/mL for near-infrared dyes has been demonstrated on a single platform over a wide spectral range, as well as an absorption-based water quality test, showing the versatility of the system across liquid solutions for different emission and absorption bands. Comparison with a commercially available portable spectrometer and an optical spectrum analyzer shows our system has an improved signal-to-noise ratio and acceptable spectral resolution for discrimination of emission spectra, and characterization of colored liquid’s absorption characteristics generated by common biomolecular assays. This simple, compact, and versatile analysis platform demonstrates a path towards an integrated optical device that can be utilized for a wide variety of applications in point-of-use testing and point-of-care diagnostics.

Particulate emissions from a mid-latitude prescribed chaparral fire

Treesearch

Wesley R. Cofer; Joel S. Levine; Daniel I. Sebacher; Edward L. Winstead; Philip J. Riggan; James A. Brass; Vincent G. Ambrosia

1988-01-01

Smoke aerosol was collected on filters from a helicopter during a 400-acre (1.62 km2) prescribed chaparral burn in the San Dimas Experimental Forest on December 12, 1986. Hi-Vol samplers were used to collect particles on both Teflon and glass fiber filters. Scanning electron microscopy of the filters revealed particles that ranged in size from...

Sources of particulate matter components in the Athabasca oil sands region: investigation through a comparison of trace element measurement methodologies

NASA Astrophysics Data System (ADS)

Phillips-Smith, Catherine; Jeong, Cheol-Heon; Healy, Robert M.; Dabek-Zlotorzynska, Ewa; Celo, Valbona; Brook, Jeffrey R.; Evans, Greg

2017-08-01

The province of Alberta, Canada, is home to three oil sands regions which, combined, contain the third largest deposit of oil in the world. Of these, the Athabasca oil sands region is the largest. As part of Environment and Climate Change Canada's program in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring program, concentrations of trace elements in PM2. 5 (particulate matter smaller than 2.5 µm in diameter) were measured through two campaigns that involved different methodologies: a long-term filter campaign and a short-term intensive campaign. In the long-term campaign, 24 h filter samples were collected once every 6 days over a 2-year period (December 2010-November 2012) at three air monitoring stations in the regional municipality of Wood Buffalo. For the intensive campaign (August 2013), hourly measurements were made with an online instrument at one air monitoring station; daily filter samples were also collected. The hourly and 24 h filter data were analyzed individually using positive matrix factorization. Seven emission sources of PM2. 5 trace elements were thereby identified: two types of upgrader emissions, soil, haul road dust, biomass burning, and two sources of mixed origin. The upgrader emissions, soil, and haul road dust sources were identified through both the methodologies and both methodologies identified a mixed source, but these exhibited more differences than similarities. The second upgrader emissions and biomass burning sources were only resolved by the hourly and filter methodologies, respectively. The similarity of the receptor modeling results from the two methodologies provided reassurance as to the identity of the sources. Overall, much of the PM2. 5-related trace elements were found to be anthropogenic, or at least to be aerosolized through anthropogenic activities. These emissions may in part explain the previously reported higher levels of trace elements in snow, water, and biota samples collected near the oil sands operations.

Use of a priori spectral information in the measurement of x-ray flux with filtered diode arrays

DOE PAGES

Marrs, R. E.; Widmann, K.; Brown, G. V.; ...

2015-10-29

Filtered x-ray diode (XRD) arrays are often used to measure x-ray spectra vs. time from spectrally continuous x-ray sources such as hohlraums. A priori models of the incident x-ray spectrum enable a more accurate unfolding of the x-ray flux as compared to the standard technique of modifying a thermal Planckian with spectral peaks or dips at the response energy of each filtered XRD channel. A model x-ray spectrum consisting of a thermal Planckian, a Gaussian at higher energy, and (in some cases) a high energy background provides an excellent fit to XRD-array measurements of x-ray emission from laser heated hohlraums.more » If high-resolution measurements of part of the x-ray emission spectrum are available, that information can be included in the a priori model. In cases where the x-ray emission spectrum is not Planckian, candidate x-ray spectra can be allowed or excluded by fitting them to measured XRD voltages. Here, examples are presented from the filtered XRD arrays, named Dante, at the National Ignition Facility and the Laboratory for Laser Energetics.« less

Nitrous oxide emission by aquatic macrofauna

PubMed Central

Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter; Brix, Hans; Schramm, Andreas

2009-01-01

A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested delayed induction of the last step of denitrification. Filter- and deposit-feeding animal species showed the highest rates of nitrous oxide emission and predators the lowest, probably reflecting the different amounts of denitrifying bacteria in the diet. We estimate that nitrous oxide emission by aquatic animals is quantitatively important in nitrate-rich aquatic environments like freshwater, coastal marine, and deep-sea ecosystems. The contribution of this source to overall nitrous oxide emission from aquatic environments might further increase because of the projected increase of nitrate availability in tropical regions and the numeric dominance of filter- and deposit-feeders in eutrophic ecosystems. PMID:19255427

Emissions During and Real-world Frequency of Heavy-duty Diesel Particulate Filter Regeneration.

PubMed

Ruehl, Chris; Smith, Jeremy D; Ma, Yilin; Shields, Jennifer Erin; Burnitzki, Mark; Sobieralski, Wayne; Ianni, Robert; Chernich, Donald J; Chang, M-C Oliver; Collins, John Francis; Yoon, Seungju; Quiros, David; Hu, Shaohua; Dwyer, Harry

2018-05-15

Recent tightening of particulate matter (PM) emission standards for heavy-duty engines has spurred the widespread adoption of diesel particulate filters (DPFs), which need to be regenerated periodically to remove trapped PM. The total impact of DPFs therefore depends not only on their filtering efficiency during normal operation, but also on the emissions during and the frequency of regeneration events. We performed active (parked and driving) and passive regenerations on two heavy-duty diesel vehicles (HDDVs), and report the chemical composition of emissions during these events, as well as the efficiency with which trapped PM is converted to gas-phase products. We also collected activity data from 85 HDDVs to determine how often regeneration occurs during real-world operation. PM emitted during regeneration ranged from 0.2 to 16.3 g, and the average time and distance between real-world active regenerations was 28.0 h and 599 miles. These results indicate that regeneration of real-world DPFs does not substantially offset the reduction of PM by DPFs during normal operation. The broad ranges of regeneration frequency per truck (3-100 h and 23-4078 miles) underscore the challenges in designing engines and associated aftertreatments that reduce emissions for all real-world duty cycles.

Absolute brightness modeling for improved measurement of electron temperature from soft x-rays on MST

NASA Astrophysics Data System (ADS)

Reusch, L. M.; Franz, P.; Goetz, J. A.; den Hartog, D. J.; Nornberg, M. D.; van Meter, P.

2017-10-01

The two-color soft x-ray tomography (SXT) diagnostic on MST is now capable of Te measurement down to 500 eV. The previous lower limit was 1 keV, due to the presence of SXR emission lines from Al sputtered from the MST wall. The two-color technique uses two filters of different thickness to form a coarse spectrometer to estimate the slope of the continuum x-ray spectrum, which depends on Te. The 1.6 - 2.0 keV Al emission lines were previously filtered out by using thick Be filters (400 µm and 800 µm), thus restricting the range of the SXT diagnostic to Te >= 1 keV. Absolute brightness modeling explicitly includes several sources of radiation in the analysis model, enabling the use of thinner filters and measurement of much lower Te. Models based on the atomic database and analysis structure (ADAS) agree very well with our experimental SXR measurements. We used ADAS to assess the effect of bremsstrahlung, recombination, dielectronic recombination, and line emission on the inferred Te. This assessment informed the choice of the optimum filter pair to extend the Te range of the SXT diagnostic. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences program under Award Numbers DE-FC02-05ER54814 and DE-SC0015474.

Simulating the Impact of Premixed Charge Compression Ignition on Light-Duty Diesel Fuel Economy and Emissions of Particulates and NOx

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhiming; Daw, C Stuart; Wagner, Robert M

2013-01-01

We utilize the Powertrain Systems Analysis Toolkit (PSAT) combined with transient engine and aftertreatment component models implemented in Matlab/Simulink to simulate the effect of premixed charge compression ignition (PCCI) on the fuel economy and emissions of light-duty diesel-powered conventional and hybrid electric vehicles (HEVs). Our simulated engine is capable of both conventional diesel combustion (CDC) and premixed charge compression ignition (PCCI) over real transient driving cycles. Our simulated aftertreatment train consists of a diesel oxidation catalyst (DOC), lean NOx trap (LNT), and catalyzed diesel particulate filter (DPF). The results demonstrate that, in the simulated conventional vehicle, PCCI can significantly reducemore » fuel consumption and emissions by reducing the need for LNT and DPF regeneration. However, the opportunity for PCCI operation in the simulated HEV is limited because the engine typically experiences higher loads and multiple stop-start transients that are outside the allowable PCCI operating range. Thus developing ways of extending the PCCI operating range combined with improved control strategies for engine and emissions control management will be especially important for realizing the potential benefits of PCCI in HEVs.« less

Visibility of Prominences Using the He i D3 Line Filter on the PROBA-3/ASPIICS Coronagraph

NASA Astrophysics Data System (ADS)

Jejčič, S.; Heinzel, P.; Labrosse, N.; Zhukov, A. N.; Bemporad, A.; Fineschi, S.; Gunár, S.

2018-02-01

We determine the optimal width and shape of the narrow-band filter centered on the He i D3 line for prominence and coronal mass ejection (CME) observations with the ASPIICS ( Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun) coronagraph onboard the PROBA-3 ( Project for On-board Autonomy) satellite, to be launched in 2020. We analyze He i D3 line intensities for three representative non-local thermal equilibrium prominence models at temperatures 8, 30, and 100 kK computed with a radiative transfer code and the prominence visible-light (VL) emission due to Thomson scattering on the prominence electrons. We compute various useful relations at prominence line-of-sight velocities of 0, 100, and 300 km s-1 for 20 Å wide flat filter and three Gaussian filters with a full-width at half-maximum (FWHM) equal to 5, 10, and 20 Å to show the relative brightness contribution of the He i D3 line and the prominence VL to the visibility in a given narrow-band filter. We also discuss possible signal contamination by Na i D1 and D2 lines, which otherwise may be useful to detect comets. Our results mainly show that i) an optimal narrow-band filter should be flat or somewhere between flat and Gaussian with an FWHM of 20 Å in order to detect fast-moving prominence structures, ii) the maximum emission in the He i D3 line is at 30 kK and the minimal at 100 kK, and iii) the ratio of emission in the He i D3 line to the VL emission can provide a useful diagnostic for the temperature of prominence structures. This ratio is up to 10 for hot prominence structures, up to 100 for cool structures, and up to 1000 for warm structures.

Optimization of flow cytometric detection and cell sorting of transgenic Plasmodium parasites using interchangeable optical filters

PubMed Central

2012-01-01

Background Malaria remains a major cause of morbidity and mortality worldwide. Flow cytometry-based assays that take advantage of fluorescent protein (FP)-expressing malaria parasites have proven to be valuable tools for quantification and sorting of specific subpopulations of parasite-infected red blood cells. However, identification of rare subpopulations of parasites using green fluorescent protein (GFP) labelling is complicated by autofluorescence (AF) of red blood cells and low signal from transgenic parasites. It has been suggested that cell sorting yield could be improved by using filters that precisely match the emission spectrum of GFP. Methods Detection of transgenic Plasmodium falciparum parasites expressing either tdTomato or GFP was performed using a flow cytometer with interchangeable optical filters. Parasitaemia was evaluated using different optical filters and, after optimization of optics, the GFP-expressing parasites were sorted and analysed by microscopy after cytospin preparation and by imaging cytometry. Results A new approach to evaluate filter performance in flow cytometry using two-dimensional dot blot was developed. By selecting optical filters with narrow bandpass (BP) and maximum position of filter emission close to GFP maximum emission in the FL1 channel (510/20, 512/20 and 517/20; dichroics 502LP and 466LP), AF was markedly decreased and signal-background improve dramatically. Sorting of GFP-expressing parasite populations in infected red blood cells at 90 or 95% purity with these filters resulted in 50-150% increased yield when compared to the standard filter set-up. The purity of the sorted population was confirmed using imaging cytometry and microscopy of cytospin preparations of sorted red blood cells infected with transgenic malaria parasites. Discussion Filter optimization is particularly important for applications where the FP signal and percentage of positive events are relatively low, such as analysis of parasite-infected samples with in the intention of gene-expression profiling and analysis. The approach outlined here results in substantially improved yield of GFP-expressing parasites, and requires decreased sorting time in comparison to standard methods. It is anticipated that this protocol will be useful for a wide range of applications involving rare events. PMID:22950515

Toluene diisocyanate emission to air and migration to a surface from a flexible polyurethane foam.

PubMed

Vangronsveld, Erik; Berckmans, Steven; Spence, Mark

2013-06-01

Flexible polyurethane foam (FPF) is produced from the reaction of toluene diisocyanate (TDI) and polyols. Because of the potential for respiratory sensitization following exposure to TDI, concerns have been raised about potential consumer exposure to TDI from residual 'free TDI' in FPF products. Limited and conflicting results exist in the literature concerning the presence of unreacted TDI remaining in FPF as determined by various solvent extraction and analysis techniques. Because residual TDI results are most often intended for application in assessment of potential human exposure to TDI from FPF products, testing techniques that more accurately simulated human contact with foam were designed. To represent inhalation exposure to TDI from polyurethane foam, a test that measured the emission of TDI to air was conducted. For simulation of human dermal exposure to TDI from polyurethane foam, a migration test technique was designed. Emission of TDI to air was determined for a representative FPF using three different emission test cells. Two were commercially available cells that employ air flow over the surface of the foam [the Field and Laboratory Emission Cell (FLEC®) and the Micro-Chamber/Thermal Extraction™ cell]. The third emission test cell was of a custom design and features air flow through the foam sample rather than over the foam surface. Emitted TDI in the air of the test cells was trapped using glass fiber filters coated with 1-(2-methoxyphenyl)-piperazine (MP), a commonly used derivatizing agent for diisocyanates. The filters were subsequently desorbed and analyzed by liquid chromatography/mass spectrometry. Measurement of TDI migration from representative foam was accomplished by placing glass fiber filters coated with MP on the outer surfaces of a foam disk and then compressing the filters against the disk using a clamping apparatus for periods of 8 and 24 h. The sample filters were subsequently desorbed and analyzed in the same manner as for the emission tests. Although the foam tested had detectable levels of solvent-extractable TDI (56ng TDI g(-1) foam for the foam used in emissions tests; 240-2800ng TDI g(-1) foam for the foam used in migration tests), no TDI was detected in any of the emission or migration tests. Method detection limits (MDLs) for the emissions tests ranged from 0.03 to 0.5ng TDI g(-1) foam (0.002-0.04ng TDI cm(-2) of foam surface), whereas those for the migration tests were 0.73ng TDI g(-1) foam (0.16ng TDI cm(-2) of foam surface). Of the three emission test methods used, the FLEC® had the lowest relative MDLs (by a factor of 3-10) by virtue of its high chamber loading factor. In addition, the FLEC® cell offers well-established conformity with emission testing standard methods.

The Oxidized Low-Density Lipoprotein Receptor Mediates Vascular Effects of Inhaled Vehicle Emissions

PubMed Central

Lucero, JoAnn; Harman, Melissa; Madden, Michael C.; McDonald, Jacob D.; Seagrave, Jean Clare; Campen, Matthew J.

2011-01-01

Rationale: To determine vascular signaling pathways involved in inhaled air pollution (vehicular engine emission) exposure–induced exacerbation of atherosclerosis that are associated with onset of clinical cardiovascular events. Objectives: To elucidate the role of oxidized low-density lipoprotein (oxLDL) and its primary receptor on endothelial cells, the lectin-like oxLDL receptor (LOX-1), in regulation of endothelin-1 expression and matrix metalloproteinase activity associated with inhalational exposure to vehicular engine emissions. Methods: Atherosclerotic apolipoprotein E knockout mice were exposed by inhalation to filtered air or mixed whole engine emissions (250 μg particulate matter [PM]/m3 diesel + 50 μg PM/m3 gasoline exhausts) 6 h/d for 7 days. Concurrently, mice were treated with either mouse IgG or neutralizing antibodies to LOX-1 every other day. Vascular and plasma markers of oxidative stress and expression proatherogenic factors were assessed. In a parallel study, healthy human subjects were exposed to either 100 μg PM/m3 diesel whole exhaust or high-efficiency particulate air and charcoal-filtered “clean” air (control subjects) for 2 hours, on separate occasions. Measurements and Main Results: Mixed emissions exposure increased oxLDL and vascular reactive oxygen species, as well as LOX-1, matrix metalloproteinase-9, and endothelin-1 mRNA expression and also monocyte/macrophage infiltration, each of which was attenuated with LOX-1 antibody treatment. In a parallel study, diesel exhaust exposure in volunteer human subjects induced significant increases in plasma-soluble LOX-1. Conclusions: These findings demonstrate that acute exposure to vehicular source pollutants results in up-regulation of vascular factors associated with progression of atherosclerosis, endothelin-1, and matrix metalloproteinase-9, mediated through oxLDL–LOX-1 receptor signaling, which may serve as a novel target for future therapy. PMID:21493736

Construction, Testing, and Analysis of Radon Mitigation System

NASA Astrophysics Data System (ADS)

Jardin, Dan; Schnee, Richard; CDMS Collaboration

2011-10-01

The search for dark matter or other rare events such as neutrinoless double-beta decay is difficult in the presence of background radiation such as the alpha and beta emissions from the 222Rn decay chain. In order to reduce the radioactive background from Rn-daughters, an ultra-low radon clean room is being built at Syracuse University. A vacuum-swing adsorption system is used to mitigate the radon. Air flows through one of two tanks filled with charcoal that the radon adsorbs to, allowing the filtered air to pass into the clean room. Computer-controlled valves direct the airflow so that one tank filters the air while the other tank is purged of radon by circulating a small fraction of the cleaned airflow back through the tank at low pressure. The durations, pressures, and flow rates of each stage of building pressure, filtering, releasing pressure, and purging in the tanks are optimized in order to maximize the reduction of radon from the air. Professor.

An All-Digital Fast Tracking Switching Converter with a Programmable Order Loop Controller for Envelope Tracking RF Power Amplifiers

PubMed Central

Anabtawi, Nijad; Ferzli, Rony; Harmanani, Haidar M.

2017-01-01

This paper presents a step down, switched mode power converter for use in multi-standard envelope tracking radio frequency power amplifiers (RFPA). The converter is based on a programmable order sigma delta modulator that can be configured to operate with either 1st, 2nd, 3rd or 4th order loop filters, eliminating the need for a bulky passive output filter. Output ripple, sideband noise and spectral emission requirements of different wireless standards can be met by configuring the modulator’s filter order and converter’s sampling frequency. The proposed converter is entirely digital and is implemented in 14nm bulk CMOS process for post layout verification. For an input voltage of 3.3V, the converter’s output can be regulated to any voltage level from 0.5V to 2.5V, at a nominal switching frequency of 150MHz. It achieves a maximum efficiency of 94% at 1.5 W output power. PMID:28919657

Boundary displacement measurements using multi-energy soft x-rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tritz, K., E-mail: ktritz@pppl.gov; Stutman, D.; Diallo, A.

The Multi-Energy Soft X-ray (ME-SXR) system on NSTX provides radial profiles of soft X-ray emission, measured through a set of filters with varying thickness, which have been used to reconstruct the electron temperature on fast time scales (∼10 kHz). In addition to this functionality, here we show that the ME-SXR system can be used to measure the boundary displacement of the NSTX plasma with a few mm spatial resolution during magnetohydrodyamic (MHD) activity. Boundary displacement measurements can serve to inform theoretical predictions of neoclassical toroidal viscosity, and will be used to investigate other edge phenomena on NSTX-U. For example, boundary measurementsmore » using filtered SXR measurements can provide information on pedestal steepness and dynamic evolution leading up to and during edge localized modes (ELMs). Future applications include an assessment of a simplified, filtered SXR edge detection system as well as its suitability for real-time non-magnetic boundary feedback for ELMs, MHD, and equilibrium position control.« less

Photoprotection and photoreception of intraocular lenses under xenon and white LED illumination.

PubMed

Artigas, J M; Navea, A; García-Domene, M C; Artigas, C; Lanzagorta, A

2016-05-01

To analyze the photoprotection and phototransmission that various intraocular lenses (IOLs) provide under the illumination of a xenon (Xe) lamp and white LEDs (light emitting diode). The spectral transmission curves of six representative IOLs were measured using a Perkin-Elmer Lambda 35 UV/VIS spectrometer. Various filtering simulations were performed using a Xe lamp and white LEDs. The spectral emissions of these lamps were measured with an ILT-950 spectroradiometer. The IOLs analyzed primarily show transmission of nearly 100% in the visible spectrum. In the ultraviolet (UV) region, the filters incorporated in the various IOLs did not filter equally, and some of them let an appreciable amount of UV through. The Xe lamp presented a strong emission of ultraviolet A (UVA), and its emission under 300nm was not negligible. The white LED did not present an appreciable emission under 380nm. The cut-off wavelength of most filters is between 380 and 400nm (Physiol Hydriol60C(®), IOLTECH E4T(®), Alcon SA60AT(®), Alcon IQ SN60WF(®)), so that their UV protection is very effective. Nonetheless, the IOL OPHTEC Oculaid(®) contains a filter that, when a Xe lamp is used, lets through up to 20% for 350nm and up to 15% for 300nm, which at this point is ultraviolet B (UVB). The OPHTEC(®) Artisan IOL has a transmission peak below 300nm, which must be taken into account under Xe illumination. White LEDs do not emit energy below 380nm, so no special protection is required in the UV region. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.

Code of Federal Regulations, 2014 CFR

2014-07-01

... collecting and storing PM on a filter. You may use batch sampling to store emissions that have been diluted.... As another example, do not use PM filters that irreversibly absorb or adsorb gases to the extent that... must follow the requirements in § 1065.140(e)(2) related to PM dilution ratios. For each filter, if you...

40 CFR 1066.815 - Exhaust emission test procedures for FTP testing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... must meet the requirements related to filter face velocity as described in 40 CFR 1065.170(c)(1)(vi..., set the filter face velocity to a weighting target of 1.0 to meet the requirements of 40 CFR 1065.170(c)(1)(vi). Allow filter face velocity to decrease as a percentage of the weighting factor if the...

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.

Code of Federal Regulations, 2013 CFR

2013-07-01

... collecting and storing PM on a filter. You may use batch sampling to store emissions that have been diluted... another example, do not use PM filters that irreversibly absorb or adsorb gases to the extent that it... follow the requirements in § 1065.140(e)(2) related to PM dilution ratios. For each filter, if you expect...

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.

Code of Federal Regulations, 2012 CFR

2012-07-01

... collecting and storing PM on a filter. You may use batch sampling to store emissions that have been diluted... another example, do not use PM filters that irreversibly absorb or adsorb gases to the extent that it... follow the requirements in § 1065.140(e)(2) related to PM dilution ratios. For each filter, if you expect...

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.

Code of Federal Regulations, 2010 CFR

2010-07-01

... collecting and storing PM on a filter. You may use batch sampling to store emissions that have been diluted... another example, do not use PM filters that irreversibly absorb or adsorb gases to the extent that it... follow the requirements in § 1065.140(e)(2) related to PM dilution ratios. For each filter, if you expect...

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.

Code of Federal Regulations, 2011 CFR

2011-07-01

... collecting and storing PM on a filter. You may use batch sampling to store emissions that have been diluted... another example, do not use PM filters that irreversibly absorb or adsorb gases to the extent that it... follow the requirements in § 1065.140(e)(2) related to PM dilution ratios. For each filter, if you expect...

75 FR 42132 - Notice of Lodging of Consent Decree Pursuant to the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

... particulate filters. The hydraulic launch assist refuse collection vehicle is designed to be more efficient by... economy. The diesel particulate filters are aimed to reduce particulate matter emissions as well as carbon...

75 FR 42131 - Notice of Lodging of Consent Decree Pursuant to the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

... particulate filters. The hydraulic launch assist refuse collection vehicle is designed to be more efficient by... economy. The diesel particulate filters are aimed to reduce particulate matter emissions as well as carbon...

An audit of manufacturers' implementation of reconstruction filters in single-photon emission computed tomography.

PubMed

Lawson, Richard S; White, Duncan; Cade, Sarah C; Hall, David O; Kenny, Bob; Knight, Andy; Livieratos, Lefteris; Nijran, Kuldip

2013-08-01

The Nuclear Medicine Software Quality Group of the Institute of Physics and Engineering in Medicine has conducted an audit to compare the ways in which different manufacturers implement the filters used in single-photon emission computed tomography. The aim of the audit was to identify differences between manufacturers' implementations of the same filter and to find means for converting parameters between systems. Computer-generated data representing projection images of an ideal test object were processed using seven different commercial nuclear medicine systems. Images were reconstructed using filtered back projection and a Butter worth filter with three different cutoff frequencies and three different orders. The audit found large variations between the frequency-response curves of what were ostensibly the same filters on different systems. The differences were greater than could be explained simply by different Butter worth formulae. Measured cutoff frequencies varied between 40 and 180% of that expected. There was also occasional confusion with respect to frequency units. The audit concluded that the practical implementation of filtering, such as the size of the kernel, has a profound effect on the results, producing large differences between systems. Nevertheless, this work shows how users can quantify the frequency response of their own systems so that it will be possible to compare two systems in order to find filter parameters on each that produce equivalent results. These findings will also make it easier for users to replicate filters similar to other published results, even if they are using a different computer system.

Method for modeling driving cycles, fuel use, and emissions for over snow vehicles.

PubMed

Hu, Jiangchuan; Frey, H Christopher; Sandhu, Gurdas S; Graver, Brandon M; Bishop, Gary A; Schuchmann, Brent G; Ray, John D

2014-07-15

As input to a winter use plan, activity, fuel use, and tailpipe exhaust emissions of over snow vehicles (OSV), including five snow coaches and one snowmobile, were measured on a designated route in Yellowstone National Park (YNP). Engine load was quantified in terms of vehicle specific power (VSP), which is a function of speed, acceleration, and road grade. Compared to highway vehicles, VSP for OSVs is more sensitive to rolling resistance and less sensitive to aerodynamic drag. Fuel use rates increased linearly (R2>0.96) with VSP. For gasoline-fueled OSVs, fuel-based emission rates of carbon monoxide (CO) and nitrogen oxides (NOx) typically increased with increasing fuel use rate, with some cases of very high CO emissions. For the diesel OSVs, which had selective catalytic reduction and diesel particulate filters, fuel-based NOx and particulate matter (PM) emission rates were not sensitive to fuel flow rate, and the emission controls were effective. Inter vehicle variability in cycle average fuel use and emissions rates for CO and NOx was substantial. However, there was relatively little inter-cycle variation in cycle average fuel use and emission rates when comparing driving cycles. Recommendations are made regarding how real-world OSV activity, fuel use, and emissions data can be improved.

Measuring Solar Coronal Magnetism during the Total Solar Eclipse of 2017

NASA Astrophysics Data System (ADS)

Gibson, K. L.; Tomczyk, S.

2017-12-01

The total solar eclipse on August 21, 2017 provided a notable opportunity to measure the solar corona at specific emission wavelengths to gain information about coronal magnetic fields. Solar magnetic fields are intimately related to the generation of space weather and its effects on the earth, and the infrared imaging and polarization information collected on coronal emission lines here will enhance the scientific value of several other ongoing experiments, as well as benefit the astrophysics and upper atmosphere communities. Coronal measurements were collected during the 2 minute and 24 second totality period from Casper Mountain, WY. Computer-controlled telescopes automatically inserted four different narrow band pass filters to capture images in the visible range on a 4D PolCam, and in the infrared range on the FLIR 8501c camera. Each band pass filter selects a specific wavelength range that corresponds to a known coronal emission line possessing magnetic sensitivity. The 4D PolCam incorporated a novel grid of linear polarizers precisely aligned with the micron scale pixels. This allowed for direct measurement of the degree of linear polarization in a very small instrument with no external moving parts as is typically required. The FLIR offers short exposure times to freeze motion and output accurate thermal measurements. This allowed a new observation of the sun's corona using thermo infrared technology.

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan

PubMed Central

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-01-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child’s bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO2), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m−3, number concentrations averaged 70,777 and 1,471 L−1 in 0.3–1.0 and 1–5 µm size ranges, respectively, and the median CO2 concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m−3. Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters. PMID:21874085

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan.

PubMed

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-10-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child's bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO(2)), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m(-3), number concentrations averaged 70,777 and 1,471 L(-1) in 0.3-1.0 and 1-5 µm size ranges, respectively, and the median CO(2) concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m(-3). Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters.

40 CFR 79.57 - Emission generation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... recirculation, and feedback type. (4) Within the applicable subclass, the five highest selling vehicle/engine... emission generation vehicle/engine of the identical model, to ensure the availability of back-up emission... the filter in a sealed container, or the soluble organic fraction may be extracted and stored in a...

Quantitative comparison between full-spectrum and filter-based imaging in hyperspectral fluorescence microscopy

PubMed Central

GAO, L.; HAGEN, N.; TKACZYK, T.S.

2012-01-01

Summary We implement a filterless illumination scheme on a hyperspectral fluorescence microscope to achieve full-range spectral imaging. The microscope employs polarisation filtering, spatial filtering and spectral unmixing filtering to replace the role of traditional filters. Quantitative comparisons between full-spectrum and filter-based microscopy are provided in the context of signal dynamic range and accuracy of measured fluorophores’ emission spectra. To show potential applications, a five-colour cell immunofluorescence imaging experiment is theoretically simulated. Simulation results indicate that the use of proposed full-spectrum imaging technique may result in three times improvement in signal dynamic range compared to that can be achieved in the filter-based imaging. PMID:22356127

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

PubMed

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

2011-04-15

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

Are glass fiber particles released during the use of electronic cigarettes? Development of a semi-quantitative approach to detect glass particle emission due to vaping.

PubMed

Shin, Jae-Won; Jo, Sang-Hee; Kim, Ki-Hyun; Song, Hee-Nam; Kang, Chang-Hee; Bolan, Nanthi; Hong, Jongki

2018-05-04

This study investigated the emission characteristics of glass particles resulting from smoking electronic cigarettes (ECs). First, the most suitable filter for the collection of glass particles was explored by examining the performance (reliability) of various types of filters. A polycarbonate filter was determined as the optimum choice to collect glass particles in EC aerosol. A cartomizer was filled with EC refill solution composed of an equal volume of propylene glycol (PG) and vegetable glycol (VG). To simulate the potential conditions for glass particle emission, EC vaped aerosols were collected at three distinctive puffing intervals: (1) 0-10 puffs, (2) 101-110 puffs, and (3) 201-210 puffs (flow rate of 1 L min -1 , 2 s per puff, and 10 puffs per sample). Glass particles were observed as early as after 100 times puffing from certain products, while after 200 from others. Thus, glass particles were generated by increasing the number of puffs and usage of the EC cartomizer. The analysis of glass particles collected onto polycarbonate filters by scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) confirmed the presence of glass particles in samples collected after puffing 100-200 times. The study demonstrated that the possibility of glass particle emissions from the EC device increased considerably with the increasing number of total puffs. Copyright © 2018 Elsevier Inc. All rights reserved.

Monitoring the Near-infrared Volcanic Flux from Io's Jupiter-facing Hemisphere from Fan Mountain Observatory

NASA Astrophysics Data System (ADS)

Skrutskie, Michael F.; Nelson, Matthew J.; Schmidt, Carl

2016-10-01

Fan Mountain Observatory, near Charlottesville, Virginia, is a dark-sky site that supports a number of telescopes including a 31-inch reflecting telescope equipped with a 1024x1024 HgCdTe 1-2.5 um (YJHK) imager. Reflected sunlight ordinarily overwhelms Io's comparatively weak K-band (2.0-2.4 um) volcanic emission in unresolved observations, however when Io is eclipsed in Jupiter's shadow even a small infrared-equipped telescope can detect Io's volcanic emission. The Fan Mountain Infrared Camera observed Io in eclipse at regular intervals, typically weekly, during the few months before and after Jupiter's March 2016 opposition. When in eclipse Io's Jupiter-facing hemisphere is oriented toward Earth with sub-Earth longitudes at the time of observation ranging from 345 - 360 degrees (pre-opposition) to 0 - 15 degrees (post-opposition). A K-band filter (2.04-2.42 um) provided a bulk measurement of Io's volcanic flux weighted largely toward the 2.4 um end of this filter given the typical 500K color temperature of the volcanic emission. Most epochs also included observation in a narrowband filter centered at 2.12 um that, when combined with the broadband "long" wavelength measurement, provided a proxy for color temperature. The K-band flux of Io varied by more than 2 magnitudes during the 7 month observation interval. The [2.12 um - K-band] color of the emission strongly correlated with the K-band flux in the expected sense that the color temperature of the emission increased when Io's broadband volcanic flux was the greatest. One epoch of TripleSpec near-IR Io eclipse spectroscopy (0.90 - 2.45 um; R~3000) from the Apache Point Observatory 3.5-meter telescope provided ground truth for transforming the filter photometry into quantitative temperatures.

Audible acoustics in high-shear wet granulation: application of frequency filtering.

PubMed

Hansuld, Erin M; Briens, Lauren; McCann, Joe A B; Sayani, Amyn

2009-08-13

Previous work has shown analysis of audible acoustic emissions from high-shear wet granulation has potential as a technique for end-point detection. In this research, audible acoustic emissions (AEs) from three different formulations were studied to further develop this technique as a process analytical technology. Condenser microphones were attached to three different locations on a PMA-10 high-shear granulator (air exhaust, bowl and motor) to target different sound sources. Size, flowability and tablet break load data was collected to support formulator end-point ranges and interpretation of AE analysis. Each formulation had a unique total power spectral density (PSD) profile that was sensitive to granule formation and end-point. Analyzing total PSD in 10 Hz segments identified profiles with reduced run variability and distinct maxima and minima suitable for routine granulation monitoring and end-point control. A partial least squares discriminant analysis method was developed to automate selection of key 10 Hz frequency groups using variable importance to projection. The results support use of frequency refinement as a way forward in the development of acoustic emission analysis for granulation monitoring and end-point control.

No adverse lung effects of 7- and 28-day inhalation exposure of rats to emissions from petrodiesel fuel containing 20% rapeseed methyl esters (B20) with and without particulate filter - the FuelHealth project.

PubMed

Magnusson, Pål; Oczkowski, Michał; Øvrevik, Johan; Gajewska, Malgorzata; Wilczak, Jacek; Biedrzycki, Jacek; Dziendzikowska, Katarzyna; Kamola, Dariusz; Królikowski, Tomasz; Kruszewski, Marcin; Lankoff, Anna; Mruk, Remigiusz; Brunborg, Gunnar; Instanes, Christine; Gromadzka-Ostrowska, Joanna; Myhre, Oddvar

2017-04-01

Increased use of biofuels raises concerns about health effects of new emissions. We analyzed relative lung health effects, on Fisher 344 rats, of diesel engine exhausts emissions (DEE) from a Euro 5-classified diesel engine running on petrodiesel fuel containing 20% rapeseed methyl esters (B20) with and without diesel particulate filter (DPF). One group of animals was exposed to DEE for 7 days (6 h/day), and another group for 28 days (6 h/day, 5 days/week), both with and without DPF. The animals (n = 7/treatment) were exposed in whole body exposure chambers. Animals breathing clean air were used as controls. Genotoxic effects of the lungs by the Comet assay, histological examination of lung tissue, bronchoalveolar lavage fluid (BALF) markers of pulmonary injury, and mRNA markers of inflammation and oxidative stress were analyzed. Our results showed that a minor number of genes related to inflammation were slightly differently expressed in the exposed animals compared to control. Histological analysis also revealed only minor effects on inflammatory tissue markers in the lungs, and this was supported by flow cytometry and ELISA analysis of cytokines in BALF. No exposure-related indications of genotoxicity were observed. Overall, exposure to DEE with or without DPF technology produced no adverse effects in the endpoints analyzed in the rat lung tissue or the BALF. Overall, exposure to DEE from a modern Euro 5 light vehicle engine run on B20 fuel with or without DPF technology produced no adverse effects in the endpoints analyzed in the rat lung tissue or the BALF.

METHANOL MEASUREMENT IN AUTO EXHAUST USING A GAS-FILTER CORRELATION SPECTROMETER

EPA Science Inventory

Spectroscopic methods offer an alternative to wet chemical methods for analysis of methanol emissions from automobiles. The gas filter correlation infrared optical analysis approach appears very promising. The report describes the gas correlation optical system constructed to ana...

N2O and NO2 Emissions from Heavy-Duty Diesel Trucks with Advanced Emission Controls

NASA Astrophysics Data System (ADS)

Preble, C.; Harley, R.; Kirchstetter, T.

2014-12-01

Diesel engines are the largest source of nitrogen oxides (NOx) emissions nationally, and also a major contributor to the black carbon (BC) fraction of fine particulate matter (PM). Recently, diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems that target exhaust PM and NOx have become standard equipment on new heavy-duty diesel trucks. However, the deliberate catalytic oxidation of engine-out nitric oxide (NO) to nitrogen dioxide (NO2) in continuously regenerating DPFs leads to increased tailpipe emission of NO2. This is of potential concern due to the toxicity of NO2 and the resulting increases in atmospheric formation of other air pollutants such as ozone, nitric acid, and fine PM. While use of SCR reduces emissions of both NO and NO2, it may lead to increased emissions of nitrous oxide (N2O), a potent greenhouse gas. Here we report results from on-road measurements of heavy-duty diesel truck emissions conducted at the Port of Oakland and the Caldecott Tunnel in the San Francisco Bay Area. Emission factors (g pollutant per kg of diesel) were linked via recorded license plates to individual truck attributes, including engine model year and installed emission control equipment. Between 2009 and 2013, the fraction of DPF-equipped trucks at the Port of Oakland increased from 2 to 99%, and median engine age decreased from 11 to 6 years. Over the same period, fleet-average emission factors for black carbon and NOx decreased by 76 ± 22% and 53 ± 8%, respectively. However, direct emissions of NO2 increased, and consequently the NO2/NOx emission ratio increased from 0.03 ± 0.02 to 0.18 ± 0.03. Older trucks retrofitted with DPFs emitted approximately 3.5 times more NO2 than newer trucks equipped with both DPF and SCR. Preliminary data from summer 2014 measurements at the Caldecott Tunnel suggest that some older trucks have negative emission factors for N2O, and that for newer trucks, N2O emission factors have changed sign and are significantly increased. More comprehensive analysis of the effects of SCR on diesel NOx and N2O emissions will be reported in the presentation. These on-road emission studies indicate that advanced emission control systems such as DPF and SCR dramatically reduce PM and NOx emissions, but can cause undesirable side effects like increased NO2 and N2O emissions.

Ozone data assimilation with GEOS-Chem: a comparison between 3-D-Var, 4-D-Var, and suboptimal Kalman filter approaches

NASA Astrophysics Data System (ADS)

Singh, K.; Sandu, A.; Bowman, K. W.; Parrington, M.; Jones, D. B. A.; Lee, M.

2011-08-01

Chemistry transport models determine the evolving chemical state of the atmosphere by solving the fundamental equations that govern physical and chemical transformations subject to initial conditions of the atmospheric state and surface boundary conditions, e.g., surface emissions. The development of data assimilation techniques synthesize model predictions with measurements in a rigorous mathematical framework that provides observational constraints on these conditions. Two families of data assimilation methods are currently widely used: variational and Kalman filter (KF). The variational approach is based on control theory and formulates data assimilation as a minimization problem of a cost functional that measures the model-observations mismatch. The Kalman filter approach is rooted in statistical estimation theory and provides the analysis covariance together with the best state estimate. Suboptimal Kalman filters employ different approximations of the covariances in order to make the computations feasible with large models. Each family of methods has both merits and drawbacks. This paper compares several data assimilation methods used for global chemical data assimilation. Specifically, we evaluate data assimilation approaches for improving estimates of the summertime global tropospheric ozone distribution in August 2006 based on ozone observations from the NASA Tropospheric Emission Spectrometer and the GEOS-Chem chemistry transport model. The resulting analyses are compared against independent ozonesonde measurements to assess the effectiveness of each assimilation method. All assimilation methods provide notable improvements over the free model simulations, which differ from the ozonesonde measurements by about 20 % (below 200 hPa). Four dimensional variational data assimilation with window lengths between five days and two weeks is the most accurate method, with mean differences between analysis profiles and ozonesonde measurements of 1-5 %. Two sequential assimilation approaches (three dimensional variational and suboptimal KF), although derived from different theoretical considerations, provide similar ozone estimates, with relative differences of 5-10 % between the analyses and ozonesonde measurements. Adjoint sensitivity analysis techniques are used to explore the role of of uncertainties in ozone precursors and their emissions on the distribution of tropospheric ozone. A novel technique is introduced that projects 3-D-Variational increments back to an equivalent initial condition, which facilitates comparison with 4-D variational techniques.

40 CFR 60.2115 - What if I do not use a wet scrubber to comply with the emission limitations?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., activated carbon injection, selective noncatalytic reduction, or an electrostatic precipitator to comply..., activated carbon injection, selective noncatalytic reduction, fabric filter, or an electrostatic precipitator or limit emissions in some other manner, including material balances, to comply with the emission...

40 CFR 60.2115 - What if I do not use a wet scrubber to comply with the emission limitations?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., activated carbon injection, selective noncatalytic reduction, or an electrostatic precipitator to comply..., activated carbon injection, selective noncatalytic reduction, fabric filter, or an electrostatic precipitator or limit emissions in some other manner, including material balances, to comply with the emission...

40 CFR 60.2680 - What if I do not use a wet scrubber to comply with the emission limitations?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., activated carbon injection, selective noncatalytic reduction, or an electrostatic precipitator to comply..., activated carbon injection, selective noncatalytic reduction, fabric filter, or an electrostatic precipitator or limit emissions in some other manner, including mass balances, to comply with the emission...

Anomalous CO2 Emissions in Different Ecosystems Around the World

NASA Astrophysics Data System (ADS)

Sanchez-Canete, E. P.; Moya Jiménez, M. R.; Kowalski, A. S.; Serrano-Ortiz, P.; López-Ballesteros, A.; Oyonarte, C.; Domingo, F.

2016-12-01

As an important tool for understanding and monitoring ecosystem dynamics at ecosystem level, the eddy covariance (EC) technique allows the assessment of the diurnal and seasonal variation of the net ecosystem exchange (NEE). Despite the high temporal resolution data available, there are still many processes (in addition to photosynthesis and respiration) that, although they are being monitored, have been neglected. Only a few authors have studied anomalous CO2 emissions (non biological), and have related them to soil ventilation, photodegradation or geochemical processes. The aim of this study is: 1) to identify anomalous short term CO2 emissions in different ecosystems distributed around the world, 2) to determine the meteorological variables that are influencing these emissions, and 3) to explore the potential processes that can be involved. We have studied EC data together with other meteorological ancillary variables obtained from the FLUXNET database (version 2015) and have found more than 50 sites with anomalous CO2 emissions in different ecosystem types such as grasslands, croplands or savannas. Data were filtered according to the FLUXNET quality control flags (only data with quality control flag equal to 0 was used) and correlation analysis were performed with NEE and ancillary data. Preliminary results showed strong and highly significant correlations between meteorological variables and anomalous CO2 emissions. Correlation results showed clear differing behaviors between ecosystems types, which could be related to the different processes involved in the anomalous CO2 emissions. We suggest that anomalous CO2 emissions are happening globally and therefore, their contribution to the global net ecosystem carbon balance requires further investigation in order to better understand its drivers.

Development of a tunable Fabry-Perot interferometer UV camera for monitoring sulfur dioxide emissions

NASA Astrophysics Data System (ADS)

Tamminen, J.; Kujanpää, J.; Ojanen, H.; Saari, H.; Näkki, I.; Tukiainen, S.; Kyrölä, E.

2017-12-01

We present a novel UV camera for sulfur dioxide emission monitoring.The camera is equipped with a piezo-actuated Fabry-Perot interferometer allowing thefilter transmission to be tuned to match the differential absorption features ofsulfur dioxide in the wavelength region 305-320 nm. The differential absorption structuresare exploited to reduce the interfering effects of weakly wavelength dependent absorbers, suchas aerosols and black carbon, present in the exhaust gas. A data processing algorithm basedon two air gaps of the filter is presented allowing collection of a sufficient signal-to-noise ratio fordetecting sulfur dioxide in the ship plumes even in the designated emission control areas, such as the Baltic Seawhere the sulfur content limit of fuel oil is 0.1 %. First field tests performed inLänsisatama harbour, Helsinki Finland, indicate that sulfur dioxide can be detectedin ship plumes. The camera is light-weight and can be mounted to a drone.

Simulated Fuel Economy and Emissions Performance during City and Interstate Driving for a Heavy-Duty Hybrid Truck

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daw, C. Stuart; Gao, Zhiming; Smith, David E.

2013-04-08

We compare simulated fuel economy and emissions for both conventional and hybrid class 8 heavy-duty diesel trucks operating over multiple urban and highway driving cycles. Both light and heavy freight loads were considered, and all simulations included full aftertreatment for NOx and particulate emissions controls. The aftertreatment components included a diesel oxidation catalyst (DOC), urea-selective catalytic NOx reduction (SCR), and a catalyzed diesel particulate filter (DPF). Our simulated hybrid powertrain was configured with a pre-transmission parallel drive, with a single electric motor between the clutch and gearbox. A conventional HD truck with equivalent diesel engine and aftertreatment was also simulatedmore » for comparison. Our results indicate that hybridization can significantly increase HD fuel economy and improve emissions control in city driving. However, there is less potential hybridization benefit for HD highway driving. A major factor behind the reduced hybridization benefit for highway driving is that there are fewer opportunities to utilize regenerative breaking. Our aftertreatment simulations indicate that opportunities for passive DPF regeneration are much greater for both hybrid and conventional trucks during highway driving due to higher sustained exhaust temperatures. When passive DPF regeneration is extensively utilized, the fuel penalty for particulate control is virtually eliminated, except for the 0.4%-0.9% fuel penalty associated with the slightly higher exhaust backpressure.« less

Evaluation of alternative filter media for particulate matter emission testing of residential wood heating devices

DOE PAGES

Allen, George; Rector, Lisa; Butcher, Thomas; ...

2017-07-31

The performance of Teflon-coated glass fiber filter media (Pallflex Emfab TX40) is evaluated for particulate matter (PM) sampling of residential wood heating devices in a dilution tunnel. Thirty samples of varying duration and PM loading and concentration were collected from an U.S. Environmental Protection Agency (EPA) Method 28 dilution tunnel using dual Method 5G sample trains with untreated glass fiber and Emfab filters. Filters were weighed soon after the end of sampling and again the next day after equilibration at 35% relative humidity (RH). PM concentrations from both types of filters agreed very well with 1-day equilibration, demonstrating that Emfabmore » filters are appropriate for use in measuring PM from residential wood burning appliances in a dilution tunnel and have performance equal to or better than the glass fiber filter media. Agreement between filter media without equilibration was erratic, with PM from glass fiber filter samples varying from slightly less than the Emfab samples to as much as 2.8 times higher. Some of the glass fiber filters lost substantial mass with equilibration, with the highest percent loss at lower filter mass loadings. Mass loss for Emfab samples was a small percentage of the mass and very consistent across the range of mass loadings. Taken together, these results may indicate water uptake on the glass fiber media that is readily removed with 1-day equilibration at moderate RH conditions. Implications: EPA regulations now allow the use of either glass fiber or Teflon filter media for wood appliance PM emission testing. Teflon filter media minimizes the potential for acid-gas PM artifacts on glass fiber filters; this is important as EPA moves toward the use of locally sourced cordwood for testing that may have higher sulfur content. This work demonstrates that the use of Teflon-coated glass fiber filters can give similar PM measurement results to glass fiber filters after 1 day of equilibration. With no equilibration, measured PM from glass fiber filters was usually higher than from Teflon-coated glass fiber filters.« less

Evaluation of alternative filter media for particulate matter emission testing of residential wood heating devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, George; Rector, Lisa; Butcher, Thomas

The performance of Teflon-coated glass fiber filter media (Pallflex Emfab TX40) is evaluated for particulate matter (PM) sampling of residential wood heating devices in a dilution tunnel. Thirty samples of varying duration and PM loading and concentration were collected from an U.S. Environmental Protection Agency (EPA) Method 28 dilution tunnel using dual Method 5G sample trains with untreated glass fiber and Emfab filters. Filters were weighed soon after the end of sampling and again the next day after equilibration at 35% relative humidity (RH). PM concentrations from both types of filters agreed very well with 1-day equilibration, demonstrating that Emfabmore » filters are appropriate for use in measuring PM from residential wood burning appliances in a dilution tunnel and have performance equal to or better than the glass fiber filter media. Agreement between filter media without equilibration was erratic, with PM from glass fiber filter samples varying from slightly less than the Emfab samples to as much as 2.8 times higher. Some of the glass fiber filters lost substantial mass with equilibration, with the highest percent loss at lower filter mass loadings. Mass loss for Emfab samples was a small percentage of the mass and very consistent across the range of mass loadings. Taken together, these results may indicate water uptake on the glass fiber media that is readily removed with 1-day equilibration at moderate RH conditions. Implications: EPA regulations now allow the use of either glass fiber or Teflon filter media for wood appliance PM emission testing. Teflon filter media minimizes the potential for acid-gas PM artifacts on glass fiber filters; this is important as EPA moves toward the use of locally sourced cordwood for testing that may have higher sulfur content. This work demonstrates that the use of Teflon-coated glass fiber filters can give similar PM measurement results to glass fiber filters after 1 day of equilibration. With no equilibration, measured PM from glass fiber filters was usually higher than from Teflon-coated glass fiber filters.« less

The Imager for Sprites and Upper Atmospheric Lightning (ISUAL)

NASA Astrophysics Data System (ADS)

Frey, H. U.; Mende, S. B.; Harris, S. E.; Heetderks, H.; Takahashi, Y.; Su, H.-T.; Hsu, R.-R.; Chen, A. B.; Fukunishi, H.; Chang, Y.-S.; Lee, L.-C.

2016-08-01

The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) was the first specifically dedicated instrument to observe lightning-induced transient luminous events (TLE): sprites, elves, halos, and gigantic jets from space. The Imager is an intensified CCD system operating in the visible wavelength region with a filter wheel to select from six positions with filters. The Imager has a 5° × 20° (vertical times horizontal) field of view. The spectrophotometer (SP) is populated with six photometers with individual filters for emissions from the far ultraviolet to the near infrared. An array photometer with two channels operating in the blue and red provides altitude profiles of the emission over 16 altitude bins each. The Associated Electronics Package (AEP) controls instrument functions and interfaces with the spacecraft. ISUAL was launched 21 May 2004 into a Sun-synchronous 890 km orbit on the Formosat-2 satellite and has successfully been collecting data ever since. ISUAL is running on the nightside of the orbit and is pointed to the east of the orbit down toward the limb. The instrument runs continuously and writes data to a circular buffer. Whenever the SP detects a sudden signal increase above a preset threshold, a trigger signal is generated that commands the system to keep the data for about 400 ms starting from ~50 ms before the trigger. Over its lifetime of ~11 years the system recorded thousands of TLE and also successfully observed aurora and airglow.

Design and Development of an Electrostatic Screen Battery for Emission Control (ESBEC)

PubMed Central

Han, Taewon; Mainelis, Gediminas

2017-01-01

Current diesel particulate filters (DPFs) can effectively capture the exhaust particles, but they add to engine backpressure and accumulate particles during their operation, which results in the need to regenerate the DPFs by burning off the collected particles periodically. This regeneration results in aerosol emissions, especially in the 10–30 nanometer size range and contributes to ultrafine particle pollution. In this research, we designed and developed a prototype of a novel diesel exhaust control device: the Electrostatic Screen Battery for Emissions Control (ESBEC). The device features high particle collection efficiency without adding to the exhaust backpressure and without the need for thermal regeneration of the collected particles. The ESBEC consists of a series of metal mesh screens coated with a superhydrophobic substance and an integrated carbon fiber ionizer to charge the incoming particles. Multiple pairs of screens (e.g., 5 pairs) are arranged in a battery, in which one screen of each pair is supplied with high voltage, and the other is grounded, producing electrostatic field produced across the screens. The application of a superhydrophobic coating onto the screens allows easy removal of the collected particles using liquid without the need for thermal regeneration. The current prototypes of the device were tested with fluorescent polystyrene latex (PSL) particles of 0.2 and 1.2 μm in size and at 25 and 105 L/min sampling flow rates. The average collection efficiency was ~87% for 0.2 μm and ~95% for 1.2 μm PSL particles. In addition, the ESBEC was tested with actual diesel exhaust particles; here its performance was verified by visually inspecting deposition of particles on an after-filter with the device ON and OFF. In the next stages of this work, the ESBEC will be challenged with diesel exhaust at different mass concentrations and for different collection time periods. PMID:28983124

Design and Development of an Electrostatic Screen Battery for Emission Control (ESBEC).

PubMed

Han, Taewon; Mainelis, Gediminas

2017-05-01

Current diesel particulate filters (DPFs) can effectively capture the exhaust particles, but they add to engine backpressure and accumulate particles during their operation, which results in the need to regenerate the DPFs by burning off the collected particles periodically. This regeneration results in aerosol emissions, especially in the 10-30 nanometer size range and contributes to ultrafine particle pollution. In this research, we designed and developed a prototype of a novel diesel exhaust control device: the Electrostatic Screen Battery for Emissions Control (ESBEC). The device features high particle collection efficiency without adding to the exhaust backpressure and without the need for thermal regeneration of the collected particles. The ESBEC consists of a series of metal mesh screens coated with a superhydrophobic substance and an integrated carbon fiber ionizer to charge the incoming particles. Multiple pairs of screens (e.g., 5 pairs) are arranged in a battery, in which one screen of each pair is supplied with high voltage, and the other is grounded, producing electrostatic field produced across the screens. The application of a superhydrophobic coating onto the screens allows easy removal of the collected particles using liquid without the need for thermal regeneration. The current prototypes of the device were tested with fluorescent polystyrene latex (PSL) particles of 0.2 and 1.2 μm in size and at 25 and 105 L/min sampling flow rates. The average collection efficiency was ~87% for 0.2 μm and ~95% for 1.2 μm PSL particles. In addition, the ESBEC was tested with actual diesel exhaust particles; here its performance was verified by visually inspecting deposition of particles on an after-filter with the device ON and OFF. In the next stages of this work, the ESBEC will be challenged with diesel exhaust at different mass concentrations and for different collection time periods.

Industrial hazardous waste treatment featuring a rotary kiln and grate furnace incinerator: a case study in China.

PubMed

Ma, Pan; Ma, Zengyi; Yan, Jianhua; Chi, Yong; Ni, Mingjiang; Cen, Kefa

2011-10-01

As one of the fastest developing countries, China is facing severe problems concerning hazardous waste treatment and disposal. This paper presents a new incineration technology and demonstration project in eastern China. The incineration system includes a rotary kiln, a grate furnace for burning out the kiln residue and a flue gas post-combustion chamber. Flue gas treatment and emission control is based on: a quench tower, followed by dry hydrated lime and activated carbon injection, a dual bag filter system, and a wet scrubber. It demonstrated that this incineration technology can effectively dispose of industrial hazardous waste with variable and complex characteristics. Gas emissions meet the demands of the Chinese Environmental Protection Association standard.

Efficient carrier-envelope offset frequency stabilization through gain modulation via stimulated emission.

PubMed

Karlen, Lauriane; Buchs, Gilles; Portuondo-Campa, Erwin; Lecomte, Steve

2016-01-15

A novel scheme for intracavity control of the carrier-envelope offset (CEO) frequency of a 100 MHz mode-locked Er:Yb:glass diode-pumped solid-state laser (DPSSL) based on the modulation of the laser gain via stimulated emission of the excited Er(3+) ions is demonstrated. This method allows us to bypass the ytterbium system few-kHz low-pass filter in the f(CEO) stabilization loop and thus to push the phase lock bandwidth up to a limit close to the relaxation oscillations frequency of the erbium system. A phase lock bandwidth above 70 kHz has been achieved with the fully stabilized laser, leading to an integrated phase noise [1 Hz-1 MHz] of 120 mrad.

Performance of particulate containment at nanotechnology workplaces

NASA Astrophysics Data System (ADS)

Lo, Li-Ming; Tsai, Candace S.-J.; Dunn, Kevin H.; Hammond, Duane; Marlow, David; Topmiller, Jennifer; Ellenbecker, Michael

2015-11-01

The evaluation of engineering controls for the production or use of carbon nanotubes (CNTs) was investigated at two facilities. These control assessments are necessary to evaluate the current status of control performance and to develop proper control strategies for these workplaces. The control systems evaluated in these studies included ventilated enclosures, exterior hoods, and exhaust filtration systems. Activity-based monitoring with direct-reading instruments and filter sampling for microscopy analysis were used to evaluate the effectiveness of control measures at study sites. Our study results showed that weighing CNTs inside the biological safety cabinet can have a 37 % reduction on the particle concentration in the worker's breathing zone, and produce a 42 % lower area concentration outside the enclosure. The ventilated enclosures used to reduce fugitive emissions from the production furnaces exhibited good containment characteristics when closed, but they failed to contain emissions effectively when opened during product removal/harvesting. The exhaust filtration systems employed for exhausting these ventilated enclosures did not provide promised collection efficiencies for removing engineered nanomaterials from furnace exhaust. The exterior hoods were found to be a challenge for controlling emissions from machining nanocomposites: the downdraft hood effectively contained and removed particles released from the manual cutting process, but using the canopy hood for powered cutting of nanocomposites created 15-20 % higher ultrafine (<500 nm) particle concentrations at the source and at the worker's breathing zone. The microscopy analysis showed that CNTs can only be found at production sources but not at the worker breathing zones during the tasks monitored.

Comparison of Parallel and Series Hybrid Power Trains for Transit Bus Applications

DOE PAGES

Gao, Zhiming; Daw, C. Stuart; Smith, David E.; ...

2016-08-01

The fuel economy and emissions of conventional and hybrid buses equipped with emissions after treatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicated that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar carbon monoxide and hydrocarbon tailpipe emissions but were also predicted to have reduced tailpipe emissions of nitrogen oxides compared with the conventional bus in higher speed cycles. For the New York bus cycle, which hasmore » the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus; the parallel hybrid bus had significantly lower tailpipe emissions. All three bus power trains were found to require periodic active diesel particulate filter regeneration to maintain control of particulate matter. Finally, plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed because of the relatively large battery capacity that is typical of the series hybrid configuration.« less

Comparison of Parallel and Series Hybrid Power Trains for Transit Bus Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhiming; Daw, C. Stuart; Smith, David E.

The fuel economy and emissions of conventional and hybrid buses equipped with emissions after treatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicated that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar carbon monoxide and hydrocarbon tailpipe emissions but were also predicted to have reduced tailpipe emissions of nitrogen oxides compared with the conventional bus in higher speed cycles. For the New York bus cycle, which hasmore » the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus; the parallel hybrid bus had significantly lower tailpipe emissions. All three bus power trains were found to require periodic active diesel particulate filter regeneration to maintain control of particulate matter. Finally, plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed because of the relatively large battery capacity that is typical of the series hybrid configuration.« less

Fiber-optic apparatus and method for measurement of luminescence and raman scattering

DOEpatents

Myrick, Michael L.; Angel, Stanley M.

1993-01-01

A dual fiber forward scattering optrode for Raman spectroscopy with the remote ends of the fibers in opposed, spaced relationship to each other to form a analyte sampling space therebetween and the method of measuring Raman spectra utilizing same. One optical fiber is for sending an exciting signal to the remote sampling space and, at its remote end, has a collimating microlens and an optical filter for filtering out background emissions generated in the fiber. The other optical fiber is for collecting the Raman scattering signal at the remote sampling space and, at its remote end, has a collimating microlens and an optical filter to prevent the exciting signal from the exciting fiber from entering the collection fiber and to thereby prevent the generation of background emissions in the collecting fiber.

A benefit-cost analysis of retrofitting diesel vehicles with particulate filters in the Mexico City metropolitan area.

PubMed

Stevens, Gretchen; Wilson, Andrew; Hammitt, James K

2005-08-01

In the Mexico City metropolitan area, poor air quality is a public health concern. Diesel vehicles contribute significantly to the emissions that are most harmful to health. Harmful diesel emissions can be reduced by retrofitting vehicles with one of several technologies, including diesel particulate filters. We quantified the social costs and benefits, including health benefits, of retrofitting diesel vehicles in Mexico City with catalyzed diesel particulate filters, actively regenerating diesel particulate filters, or diesel oxidation catalysts, either immediately or in 2010, when capital costs are expected to be lower. Retrofit with either type of diesel particulate filter or an oxidation catalyst is expected to provide net benefits to society beginning immediately and in 2010. At current prices, retrofit with an oxidation catalyst provides greatest net benefits. However, as capital costs decrease, retrofit with diesel particulate filters is expected to provide greater net benefits. In both scenarios, retrofit of older, dirtier vehicles that circulate only within the city provides greatest benefits, and retrofit with oxidation catalysts provides greater health benefits per dollar spent than retrofit with particulate filters. Uncertainty about the magnitude of net benefits of a retrofit program is significant. Results are most sensitive to values used to calculate benefits, such as the concentration-response coefficient, intake fraction (a measure of exposure), and the monetary value of health benefits.

Pulmonary function in workers exposed to diesel exhausts: the effect of control measures.

PubMed

Ulfvarson, U; Alexandersson, R; Dahlqvist, M; Ekholm, U; Bergström, B

1991-01-01

To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

The combination of two novel tobacco blends and filter technologies to reduce the in vitro genotoxicity and cytotoxicity of prototype cigarettes.

PubMed

Crooks, Ian; Scott, Ken; Dalrymple, Annette; Dillon, Debbie; Meredith, Clive

2015-04-01

Tobacco smoke from a combustible cigarette contains more than 6000 constituents; approximately 150 of these are identified as toxicants. Technologies that modify the tobacco blend to reduce toxicant emissions have been developed. These include tobacco sheet substitute to dilute toxicants in smoke and blend treated tobacco to reduce the levels of nitrogenous precursors and some polyphenols. Filter additives to reduce gas (vapour) phase constituents have also been developed. In this study, both tobacco blend and filter technologies were combined into an experimental cigarette and smoked to International Organisation on Standardisation and Health Canada puffing parameters. The resulting particulate matter was subjected to a battery of in vitro genotoxicity and cytotoxicity assays - the Ames test, mouse lymphoma assay, the in vitro micronucleus test and the Neutral Red Uptake assay. The results indicate that cigarettes containing toxicant reducing technologies may be developed without observing new additional genotoxic hazards as assessed by the assays specified. In addition, reductions in bacterial mutagenicity and mammalian genotoxicity of the experimental cigarette were observed relative to the control cigarettes. There were no significant differences in cytotoxicity relative to the control cigarettes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Ultrafine particle emissions by in-use diesel buses of various generations at low-load regimes

NASA Astrophysics Data System (ADS)

Tartakovsky, L.; Baibikov, V.; Comte, P.; Czerwinski, J.; Mayer, A.; Veinblat, M.; Zimmerli, Y.

2015-04-01

Ultrafine particles (UFP) are major contributors to air pollution due to their easy gas-like penetration into the human organism, causing adverse health effects. This study analyzes UFP emissions by buses of different technologies (from Euro II till Euro V EEV - Enhanced Environmentally-friendly Vehicle) at low-load regimes. Additionally, the emission-reduction potential of retrofitting with a diesel particle filter (DPF) is demonstrated. A comparison of the measured, engine-out, particle number concentrations (PNC) for buses of different technological generations shows that no substantial reduction of engine-out emissions at low-load operating modes is observed for newer bus generations. Retrofitting the in-use urban and interurban buses of Euro II till Euro IV technologies by the VERT-certified DPF confirmed its high efficiency in reduction of UFP emissions. Particle-count filtration efficiency values of the retrofit DPF were found to be extremely high - greater than 99.8%, similar to that of the OEM filter in the Euro V bus.

Highly efficient phosphor-converted white organic light-emitting diodes with moderate microcavity and light-recycling filters.

PubMed

Cho, Sang-Hwan; Oh, Jeong Rok; Park, Hoo Keun; Kim, Hyoung Kun; Lee, Yong-Hee; Lee, Jae-Gab; Do, Young Rag

2010-01-18

We demonstrate the combined effects of a microcavity structure and light-recycling filters (LRFs) on the forward electrical efficiency of phosphor-converted white organic light-emitting diodes (pc-WOLEDs). The introduction of a single pair of low- and high-index layers (SiO(2)/TiO(2)) improves the blue emission from blue OLED and the insertion of blue-passing and yellow-reflecting LRFs enhances the forward yellow emission from the YAG:Ce(3+) phosphors layers. The enhancement of the luminous efficacy of the forward white emission is 1.92 times that of a conventional pc-WOLED with color coordinates of (0.34, 0.34) and a correlated color temperature of about 4800 K.

High-Resolution Large Field-of-View FUV Compact Camera

NASA Technical Reports Server (NTRS)

Spann, James F.

2006-01-01

The need for a high resolution camera with a large field of view and capable to image dim emissions in the far-ultraviolet is driven by the widely varying intensities of FUV emissions and spatial/temporal scales of phenomena of interest in the Earth% ionosphere. In this paper, the concept of a camera is presented that is designed to achieve these goals in a lightweight package with sufficient visible light rejection to be useful for dayside and nightside emissions. The camera employs the concept of self-filtering to achieve good spectral resolution tuned to specific wavelengths. The large field of view is sufficient to image the Earth's disk at Geosynchronous altitudes and capable of a spatial resolution of >20 km. The optics and filters are emphasized.

Wavelength dependence of l/f noise in the light output of laser diodes; An experimental study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fronen, R.J.

1990-10-01

The optical power emitted by a monomode GaAlAs laser is filtered with a monochromator. The 1/f noise in the filtered emission is found to be directly dependent on the noncoherent emission, such as S{sub p} {proportional to} P{sup m {sub nc}}. Here S{sub p} is the spectral density of the 1/f fluctuations, P{sub nc} is the average noncoherent power, m = 3/2 under spontaneous emission, and m=4 in the superradiation and laser regions. This paper reports that study of the 1/f noise in the optical power in a band centered at the laser wavelength and with variable bandwidth shows threemore » operating regions.« less

Evaluating the effects of China's pollution controls on inter-annual trends and uncertainties of atmospheric mercury emissions

NASA Astrophysics Data System (ADS)

Zhao, Y.; Zhong, H.; Zhang, J.; Nielsen, C. P.

2015-04-01

China's anthropogenic emissions of atmospheric mercury (Hg) are effectively constrained by national air pollution control and energy efficiency policies. In this study, improved methods, based on available data from domestic field measurements, are developed to quantify the benefits of Hg abatement by various emission control measures. Those measures include increased use of (1) flue gas desulfurization (FGD) and selective catalyst reduction (SCR) systems in power generation; (2) precalciner kilns with fabric filters (FF) in cement production; (3) mechanized coking ovens with electrostatic precipitators (ESP) in iron and steel production; and (4) advanced production technologies in nonferrous metal smelting. Investigation reveals declining trends in emission factors for each of these sources, which together drive a much slower growth of total Hg emissions than the growth of China's energy consumption and economy, from 679 metric tons (t) in 2005 to 750 t in 2012. In particular, estimated emissions from the above-mentioned four source types declined 3% from 2005 to 2012, which can be attributed to expanded deployment of technologies with higher energy efficiencies and air pollutant removal rates. Emissions from other anthropogenic sources are estimated to increase by 22% during the period. The species shares of total Hg emissions have been stable in recent years, with mass fractions of around 55, 39, and 6% for gaseous elemental Hg (Hg0), reactive gaseous mercury (Hg2+), and particle-bound mercury (Hgp), respectively. The higher estimate of total Hg emissions than previous inventories is supported by limited simulation of atmospheric chemistry and transport. With improved implementation of emission controls and energy saving, a 23% reduction in annual Hg emissions from 2012 to 2030, to below 600 t, is expected at the most. While growth in Hg emissions has been gradually constrained, uncertainties quantified by Monte Carlo simulation for recent years have increased, particularly for the power sector and particular industrial sources. The uncertainty (expressed as 95% confidence intervals) of Hg emissions from coal-fired power plants, for example, increased from -48-+73% in 2005 to -50-+89% in 2012. This is attributed mainly to increased penetration of advanced manufacturing and pollutant control technologies; the unclear operational status and relatively small sample sizes of field measurements of those processes have resulted in lower but highly varied emission factors. To reduce uncertainty and further confirm the benefits of pollution control and energy polices, therefore, systematic investigation of specific Hg pollution sources is recommended. The variability of temporal trends and spatial distributions of Hg emissions needs to be better tracked during the ongoing dramatic changes in China's economy, energy use, and air pollution status.

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.11552 - What are my monitoring requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an...? 63.11552 Section 63.11552 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

Relating the variability of tone-burst otoacoustic emission and auditory brainstem response latencies to the underlying cochlear mechanics

NASA Astrophysics Data System (ADS)

Verhulst, Sarah; Shera, Christopher A.

2015-12-01

Forward and reverse cochlear latency and its relation to the frequency tuning of the auditory filters can be assessed using tone bursts (TBs). Otoacoustic emissions (TBOAEs) estimate the cochlear roundtrip time, while auditory brainstem responses (ABRs) to the same stimuli aim at measuring the auditory filter buildup time. Latency ratios are generally close to two and controversy exists about the relationship of this ratio to cochlear mechanics. We explored why the two methods provide different estimates of filter buildup time, and ratios with large inter-subject variability, using a time-domain model for OAEs and ABRs. We compared latencies for twenty models, in which all parameters but the cochlear irregularities responsible for reflection-source OAEs were identical, and found that TBOAE latencies were much more variable than ABR latencies. Multiple reflection-sources generated within the evoking stimulus bandwidth were found to shape the TBOAE envelope and complicate the interpretation of TBOAE latency and TBOAE/ABR ratios in terms of auditory filter tuning.

Particulate filtration from emissions of a plasma pyrolysis assembly reactor using regenerable porous metal filters

NASA Technical Reports Server (NTRS)

Berger, Gordon M.; Agui, Juan H.; Vijayakumar, R.; Abney, Morgan B.; Greenwood, Zachary W.; West, Philip J.; Mitchell, Karen O.

2017-01-01

Microwave-based plasma pyrolysis technology is being studied as a means of supporting oxygen recovery in future spacecraft life support systems. The process involves the conversion of methane produced from a Sabatier reactor to acetylene and hydrogen, with a small amount of solid carbon particulates generated as a side product. The particles must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on porous metal media filters for removing the carbon particulate emissions from the PPA exit gas stream and to provide in situ media regeneration capability. Because of the high temperatures involved in oxidizing the deposited carbon during regeneration, there was particular focus in this development on the materials that could be used, the housing design, and heating methods. This paper describes the design and operation of the filter and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC.

Particulate Filtration from Emissions of a Plasma Pyrolysis Assembly Reactor Using Regenerable Porous Metal Filters

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Abney, Morgan; Greenwood, Zachary; West, Philip; Mitchell, Karen; Vijayakumar, R.; Berger, Gordon M.

2017-01-01

Microwave-based plasma pyrolysis technology is being studied as a means of supporting oxygen recovery in future spacecraft life support systems. The process involves the conversion of methane produced from a Sabatier reactor to acetylene and hydrogen, with a small amount of solid carbon particulates generated as a side product. The particles must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on porous metal media filters for removing the carbon particulate emissions from the PPA exit gas stream and to provide in situ media regeneration capability. Because of the high temperatures involved in oxidizing the deposited carbon during regeneration, there was particular focus in this development on the materials that could be used, the housing design, and heating methods. This paper describes the design and operation of the filter and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC.

Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Green, Robert; Vijayakumar, R.; Berger, Gordon; Greenwood, Zach; Abney, Morgan; Peterson, Elspeth

2016-01-01

NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

Controlling satellite communication system unwanted emissions in congested RF spectrum

NASA Astrophysics Data System (ADS)

Olsen, Donald; Heymann, Roger

2007-09-01

The International Telecommunication Union (ITU), a United Nations (UN) agency, is the agency that, under an international treaty, sets radio spectrum usage regulations among member nations. Within the United States of America (USA), the organization that sets regulations, coordinates an application for use, and provides authorization for federal government/agency use of the radio frequency (RF) spectrum is the National Telecommunications and Information Administration (NTIA). In this regard, the NTIA defines which RF spectrum is available for federal government use in the USA, and how it is to be used. The NTIA is a component of the United States (U.S.) Department of Commerce of the federal government. The significance of ITU regulations is that ITU approval is required for U.S. federal government/agency permission to use the RF spectrum outside of U.S. boundaries. All member nations have signed a treaty to do so. U.S. federal regulations for federal use of the RF spectrum are found in the Manual of Regulations and Procedures for Federal Radio Frequency Management, and extracts of the manual are found in what is known as the Table of Frequency Allocations. Nonfederal government and private sector use of the RF spectrum within the U.S. is regulated by the Federal Communications Commission (FCC). There is a need to control "unwanted emissions" (defined to include out-of-band emissions, which are those immediately adjacent to the necessary and allocated bandwidth, plus spurious emissions) to preclude interference to all other authorized users. This paper discusses the causes, effects, and mitigation of unwanted RF emissions to systems in adjacent spectra. Digital modulations are widely used in today's satellite communications. Commercial communications sector standards are covered for the most part worldwide by Digital Video Broadcast - Satellite (DVB-S) and digital satellite news gathering (DSNG) evolutions and the second generation of DVB-S (DVB-S2) standard, developed by the European Telecommunications Standards Institute (ETSI). In the USA, the Advanced Television Systems Committee (ATSC) has adopted Europe's DVB-S and DVB-S2 standards for satellite digital transmission. With today's digital modulations, RF spectral side lobes can extend out many times the modulating frequency on either side of the carrier at excessive power levels unless filtered. Higher-order digital modulations include quadrature phase shift keying (QPSK), 8 PSK (8-ary phase shift keying), 16 APSK (also called 12-4 APSK (amplitude phase shift keying)), and 16 QAM (quadrature amplitude modulation); they are key for higher spectrum efficiency to enable higher data rate transmissions in limited available bandwidths. Nonlinear high-power amplifiers (HPAs) can regenerate frequency spectral side lobes on input-filtered digital modulations. The paper discusses technologies and techniques for controlling these spectral side lobes, such as the use of square root raised cosine (SRRC) filtering before or during the modulation process, HPA output power back-off (OPBO), and RF filters after the HPA. Spectral mask specifications are a common method of the NTIA and ITU to define spectral occupancy power limits. They are intended to reduce interference among RF spectrum users by limiting excessive radiation at frequencies beyond the regulatory allocated bandwidth.The focus here is on the communication systems of U.S. government satellites used for space research, space operations, Earth exploration satellite services (EESS), meteorological satellite services (METSATS), and other government services. The 8025 to 8400 megahertz (MHz) X band can be used to illustrate the "unwanted emissions" issue. 8025 to 8400 MHz abuts the 8400 to 8450 MHz band allocated by the NTIA and ITU to space research for space-to-Earth transmissions such as receiving very weak Deep Space Network signals. The views and ideas expressed in this paper are those of the authors and do not necessarily reflect those of The Aerospace Corporation or The National Oceanic and Atmospheric Administration (NOAA) and its National Environmental Satellite Service (NESDIS).

Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

NASA Astrophysics Data System (ADS)

Berry, Mark Simpson

The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule for existing boilers. The use of calcium bromide injection as an alternative to activated carbon approaches could save millions of dollars. The technology application described herein has the potential to reduce compliance cost by $200M for a 700 MW facility burning PRB coal.

The Least Mean Squares Adaptive FIR Filter for Narrow-Band RFI Suppression in Radio Detection of Cosmic Rays

NASA Astrophysics Data System (ADS)

Szadkowski, Zbigniew; Głas, Dariusz

2017-06-01

Radio emission from the extensive air showers (EASs), initiated by ultrahigh-energy cosmic rays, was theoretically suggested over 50 years ago. However, due to technical limitations, successful collection of sufficient statistics can take several years. Nowadays, this detection technique is used in many experiments consisting in studying EAS. One of them is the Auger Engineering Radio Array (AERA), located within the Pierre Auger Observatory. AERA focuses on the radio emission, generated by the electromagnetic part of the shower, mainly in geomagnetic and charge excess processes. The frequency band observed by AERA radio stations is 30-80 MHz. Thus, the frequency range is contaminated by human-made and narrow-band radio frequency interferences (RFIs). Suppression of contaminations is very important to lower the rate of spurious triggers. There are two kinds of digital filters used in AERA radio stations to suppress these contaminations: the fast Fourier transform median filter and four narrow-band IIR-notch filters. Both filters have worked successfully in the field for many years. An adaptive filter based on a least mean squares (LMS) algorithm is a relatively simple finite impulse response (FIR) filter, which can be an alternative for currently used filters. Simulations in MATLAB are very promising and show that the LMS filter can be very efficient in suppressing RFI and only slightly distorts radio signals. The LMS algorithm was implemented into a Cyclone V field programmable gate array for testing the stability, RFI suppression efficiency, and adaptation time to new conditions. First results show that the FIR filter based on the LMS algorithm can be successfully implemented and used in real AERA radio stations.

Rapid Pinhole Growth in the F160BW Filter

NASA Astrophysics Data System (ADS)

Biretta, J.; Verner, E.

2009-03-01

The WFPC2 Filter F160BW, also known as WOOD's filter, was designed to transmit UV emission around 150nm and strongly block all other wavelengths. The filter has a unique construction where a thin film of sodium metal serves as the spectral element. However, sodium is a highly unstable and reactive metal, which makes the filter susceptible to changes over time. Herein we report a rapidly growing pinhole in the filter located in the field of view of the WF2 CCD. Observers requiring a high rejection of out-of-band light (i.e. red leak) should take note of this feature, and avoid the affected region in the field-of-view.

High NO2/NOx emissions downstream of the catalytic diesel particulate filter: An influencing factor study.

PubMed

He, Chao; Li, Jiaqiang; Ma, Zhilei; Tan, Jianwei; Zhao, Longqing

2015-09-01

Diesel vehicles are responsible for most of the traffic-related nitrogen oxide (NOx) emissions, including nitric oxide (NO) and nitrogen dioxide (NO2). The use of after-treatment devices increases the risk of high NO2/NOx emissions from diesel engines. In order to investigate the factors influencing NO2/NOx emissions, an emission experiment was carried out on a high pressure common-rail, turbocharged diesel engine with a catalytic diesel particulate filter (CDPF). NO2 was measured by a non-dispersive ultraviolet analyzer with raw exhaust sampling. The experimental results show that the NO2/NOx ratios downstream of the CDPF range around 20%-83%, which are significantly higher than those upstream of the CDPF. The exhaust temperature is a decisive factor influencing the NO2/NOx emissions. The maximum NO2/NOx emission appears at the exhaust temperature of 350°C. The space velocity, engine-out PM/NOx ratio (mass based) and CO conversion ratio are secondary factors. At a constant exhaust temperature, the NO2/NOx emissions decreased with increasing space velocity and engine-out PM/NOx ratio. When the CO conversion ratios range from 80% to 90%, the NO2/NOx emissions remain at a high level. Copyright © 2015. Published by Elsevier B.V.

Use of a Chamber to Comprehensively Characterise Emissions and Subsequent Processes from a Light-Duty Diesel Engine

NASA Astrophysics Data System (ADS)

Allan, J. D.; Alfarra, M. R. R.; Whitehead, J.; McFiggans, G.; Kong, S.; Harrison, R. M.; Alam, M. S.; Hamilton, J. F.; Pereira, K. L.; Holmes, R. E.

2014-12-01

Around 1 in 3 light duty vehicles in the UK use diesel engines, meaning that on-road emissions of particulates, NOx and VOCs and subsequent chemical processes are substantially different to countries where gasoline engines dominate. As part of the Natural Environment Research Council (NERC) Com-Part project, emissions from a diesel engine dynamometer rig representative of the EURO 4 standard were studied. The exhaust was passed to the Manchester aerosol chamber, which consists of an 18 m3 teflon bag and by injecting a sample of exhaust fumes into filtered and chemically scrubbed air, a controllable dilution can be performed and the sample held in situ for analysis by a suite of instruments. The system also allows the injection of other chemicals (e.g. ozone, additional VOCs) and the initiation of photochemistry using a bank of halogen bulbs and a filtered Xe arc lamp to simulate solar light. Because a large volume of dilute emissions can be held for a period of hours, this permits a wide range of instrumentation to be used and relatively slow processes studied. Furthermore, because the bag is collapsible, the entire particulate contents can be collected on a filter for offline analysis. Aerosol microphysical properties are studied using a Scanning Mobility Particle Sizer (SMPS) and Centrifugal Particle Mass Analyser (CPMA); aerosol composition using a Soot Particle Aerosol Mass Spectrometer (SP-AMS), Single Particle Soot Photometer (SP2), Sunset Laboratories OC EC analyser and offline gas- and high performance liquid chromatography (employing advanced mass spectrometry such as ion trap and fourier transform ion cyclotron resonance); VOCs using comprehensive 2D gas chromatography; aerosol optical properties using a Cavity Attenuated Phase Shift Single Scattering Albedo monitor (CAPS-PMSSA), 3 wavelength Photoacoustic Soot Spectrometer (PASS-3) and Multi Angle Absorption Photometer (MAAP); particle hygroscopcity using a Hygroscopicity Tandem Differential Mobility Analyser (HTDMA) and monodisperse Cloud Condensation Nuclei counter (CCN); and measurements of ozone, NOx and CO2. Here we present the first results, where we explored the trends as a function of engine speed, load, exhaust treatment (an oxidizing catalytic converter), dilution factor and exposure to light.

M Dwarf Flare Continuum Variations on One-second Timescales: Calibrating and Modeling of ULTRACAM Flare Color Indices

NASA Astrophysics Data System (ADS)

Kowalski, Adam F.; Mathioudakis, Mihalis; Hawley, Suzanne L.; Wisniewski, John P.; Dhillon, Vik S.; Marsh, Tom R.; Hilton, Eric J.; Brown, Benjamin P.

2016-04-01

We present a large data set of high-cadence dMe flare light curves obtained with custom continuum filters on the triple-beam, high-speed camera system ULTRACAM. The measurements provide constraints for models of the near-ultraviolet (NUV) and optical continuum spectral evolution on timescales of ≈1 s. We provide a robust interpretation of the flare emission in the ULTRACAM filters using simultaneously obtained low-resolution spectra during two moderate-sized flares in the dM4.5e star YZ CMi. By avoiding the spectral complexity within the broadband Johnson filters, the ULTRACAM filters are shown to characterize bona fide continuum emission in the NUV, blue, and red wavelength regimes. The NUV/blue flux ratio in flares is equivalent to a Balmer jump ratio, and the blue/red flux ratio provides an estimate for the color temperature of the optical continuum emission. We present a new “color-color” relationship for these continuum flux ratios at the peaks of the flares. Using the RADYN and RH codes, we interpret the ULTRACAM filter emission using the dominant emission processes from a radiative-hydrodynamic flare model with a high nonthermal electron beam flux, which explains a hot, T ≈ 104 K, color temperature at blue-to-red optical wavelengths and a small Balmer jump ratio as observed in moderate-sized and large flares alike. We also discuss the high time resolution, high signal-to-noise continuum color variations observed in YZ CMi during a giant flare, which increased the NUV flux from this star by over a factor of 100. Based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium, based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofsica de Canarias, and observations, and based on observations made with the ESO Telescopes at the La Silla Paranal Observatory under programme ID 085.D-0501(A).

Experimental evaluation of main emissions during coal processing waste combustion.

PubMed

Dmitrienko, Margarita A; Legros, Jean C; Strizhak, Pavel A

2018-02-01

The total volume of the coal processing wastes (filter cakes) produced by Russia, China, and India is as high as dozens of millions of tons per year. The concentrations of CO and CO 2 in the emissions from the combustion of filter cakes have been measured directly for the first time. They are the biggest volume of coal processing wastes. There have been many discussions about using these wastes as primary or secondary components of coal-water slurries (CWS) and coal-water slurries containing petrochemicals (CWSP). Boilers have already been operationally tested in Russia for the combustion of CWSP based on filter cakes. In this work, the concentrations of hazardous emissions have been measured at temperatures ranging from 500 to 1000°С. The produced CO and CO 2 concentrations are shown to be practically constant at high temperatures (over 900°С) for all the coal processing wastes under study. Experiments have shown the feasibility to lowering the combustion temperatures of coal processing wastes down to 750-850°С. This provides sustainable combustion and reduces the CO and CO 2 emissions 1.2-1.7 times. These relatively low temperatures ensure satisfactory environmental and energy performance of combustion. Using CWS and CWSP instead of conventional solid fuels significantly reduces NO x and SO x emissions but leaves CO and CO 2 emissions practically at the same level as coal powder combustion. Therefore, the environmentally friendly future (in terms of all the main atmospheric emissions: CO, CO 2 , NO x , and SO x ) of both CWS and CWSP technologies relies on low-temperature combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.

An analysis of field-aged diesel particulate filter performance: particle emissions before, during, and after regeneration.

PubMed

Barone, Teresa L; Storey, John M E; Domingo, Norberto

2010-08-01

A field-aged, passive diesel particulate filter (DPF) used in a school bus retrofit program was evaluated for emissions of particle mass and number concentration before, during, and after regeneration. For the particle mass measurements, filter samples were collected for gravimetric analysis with a partial flow sampling system, which sampled proportionally to the exhaust flow. A condensation particle counter and scanning mobility particle sizer measured total number concentration and number-size distributions, respectively. The results of the evaluation show that the number concentration emissions decreased as the DPF became loaded with soot. However, after soot removal by regeneration, the number concentration emissions were approximately 20 times greater, which suggests the importance of the soot layer in helping to trap particles. Contrary to the number concentration results, particle mass emissions decreased from 6 +/- 1 mg/hp-hr before regeneration to 3 +/- 2 mg/hp-hr after regeneration. This indicates that nanoparticles with diameters less than 50 nm may have been emitted after regeneration because these particles contribute little to the total mass. Overall, average particle emission reductions of 95% by mass and 10,000-fold by number concentration after 4 yr of use provided evidence of the durability of a field-aged DPF. In contrast to previous reports for new DPFs in which elevated number concentrations occurred during the first 200 sec of a transient cycle, the number concentration emissions were elevated during the second half of the heavy-duty Federal Test Procedure (FTP) when high speed was sustained. This information is relevant for the analysis of mechanisms by which particles are emitted from field-aged DPFs.

A Proposed Imaging System to Spatially and Temporally Monitor Unburned Hydrocarbons in Jet Engine Exhaust

NASA Astrophysics Data System (ADS)

Berkson, Emily E.

The local air quality surrounding airports is significantly impacted by ground-based airplane operations, such as landing, taxiing, idling, and takeoff. In recent years, studies performed across the country revealed that people living near major airports suffer from increased cancer risks and higher likelihoods of developing respiratory issues. Jet engine emissions have been monitored extensively by direct probing of the exhaust, but there are currently no inexpensive, portable, and unobtrusive methods with which to study exhaust plume dynamics. This study assesses the feasibility of designing a multispectral imaging system to track the spatial-temporal nature of a jet engine plume. Ideally, the imaging system will be both inexpensive and portable enough to be deployed at any airport. We begin by characterizing the phenomenology of jet engine emissions during ground operations and select unburned hydrocarbons (UHCs) as the basis for our plume tracking. A proposed LWIR imaging system layout and radiometric governing equation is developed to predict the camera's sensor-reaching radiance. We use two methods, the Ideal Gas Law and the Gaussian Plume Equation, to three-dimensionally model the UHC concentration within the plume, which, in turn, is used to predict the plume transmission as a function of downwind distance. Radiometric models are used to predict the sensor-reaching radiance of the camera, and two filter combinations are selected to maximize the plume detectability. Each filter combination uses one filter to monitor the background radiance and one filter to trace the plume radiance. They are located at 9.001/9.333 [mum] and 9.12/12.212 [mum]. The plume tracing filters are used to assess plume detectability, and we find that that a camera with an NEDeltaT of 0.05 [K] will be able to detect the plume up to 120 seconds after the engine has passed. We conclude by predicting what filter difference the camera will observe temporally, as plumes are continuously generated and dissipated. The effect of individual UHCs on total plume transmission was also examined, and a selection of narrowband filters for monitoring specific UHCs is proposed for future work. Results will help to prototype a system for deployment at the Greater Rochester International Airport. This work will make airport emissions inventories more accessible and allow for improved governing of emission caps and pollution bylaws.

Temperature effects on particulate emissions from DPF-equipped diesel trucks operating on conventional and biodiesel fuels.

PubMed

Book, Emily K; Snow, Richard; Long, Thomas; Fang, Tiegang; Baldauf, Richard

2015-06-01

Emissions tests were conducted on two medium heavy-duty diesel trucks equipped with a particulate filter (DPF), with one vehicle using a NOx absorber and the other a selective catalytic reduction (SCR) system for control of nitrogen oxides (NOx). Both vehicles were tested with two different fuels (ultra-low-sulfur diesel [ULSD] and biodiesel [B20]) and ambient temperatures (70ºF and 20ºF), while the truck with the NOx absorber was also operated at two loads (a heavy weight and a light weight). The test procedure included three driving cycles, a cold start with low transients (CSLT), the federal heavy-duty urban dynamometer driving schedule (UDDS), and a warm start with low transients (WSLT). Particulate matter (PM) emissions were measured second-by-second using an Aethalometer for black carbon (BC) concentrations and an engine exhaust particle sizer (EEPS) for particle count measurements between 5.6 and 560 nm. The DPF/NOx absorber vehicle experienced increased BC and particle number concentrations during cold starts under cold ambient conditions, with concentrations two to three times higher than under warm starts at higher ambient temperatures. The average particle count for the UDDS showed an opposite trend, with an approximately 27% decrease when ambient temperatures decreased from 70ºF to 20ºF. This vehicle experienced decreased emissions when going from ULSD to B20. The DPF/SCR vehicle tested had much lower emissions, with many of the BC and particle number measurements below detectable limits. However, both vehicles did experience elevated emissions caused by DPF regeneration. All regeneration events occurred during the UDDS cycle. Slight increases in emissions were measured during the WSLT cycles after the regeneration. However, the day after a regeneration occurred, both vehicles showed significant increases in particle number and BC for the CSLT drive cycle, with increases from 93 to 1380% for PM number emissions compared with tests following a day with no regeneration. The use of diesel particulate filters (DPFs) on trucks is becoming more common throughout the world. Understanding how DPFs affect air pollution emissions under varying operating conditions will be critical in implementing effective air quality standards. This study evaluated particulate matter (PM) and black carbon (BC) emissions with two DPF-equipped heavy-duty diesel trucks operating on conventional fuel and a biodiesel fuel blend at varying ambient temperatures, loads, and drive cycles.

Quantum Optics with Atom-like Systems in Diamond

DTIC Science & Technology

2013-11-19

emission from the NV is separated by dichroic filters from the 532 nm excitation path ( Semrock LPD01-532RS-25) and ZPL path ( Semrock Di01- R635-25x35...before being filtered to remove any leakage or dominant raman lines (2x Semrock NF01-633U-25, Semrock LP01-633RS-25). It is then coupled into a...filtered by two narrow frequency filters (custom Andover 1 nm bandpass around 638 nm, Semrock FF01-640/14-25) and detected by a low-dark count APD (Micro

CHANGES IN THE PHYSICAL ENVIRONMENT OF THE INNER COMA OF 67P/CHURYUMOV–GERASIMENKO WITH DECREASING HELIOCENTRIC DISTANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bodewits, D.; A’Hearn, M. F.; Lara, L. M.

2016-11-01

The Wide Angle Camera of the OSIRIS instrument on board the Rosetta spacecraft is equipped with several narrow-band filters that are centered on the emission lines and bands of various fragment species. These are used to determine the evolution of the production and spatial distribution of the gas in the inner coma of comet 67P with time and heliocentric distance, here between 2.6 and 1.3 au pre-perihelion. Our observations indicate that the emission observed in the OH, O i, CN, NH, and NH{sub 2} filters is mostly produced by dissociative electron impact excitation of different parent species. We conclude thatmore » CO{sub 2} rather than H{sub 2}O is a significant source of the [O i] 630 nm emission. A strong plume-like feature observed in the CN and O i filters is present throughout our observations. This plume is not present in OH emission and indicates a local enhancement of the CO{sub 2}/H{sub 2}O ratio by as much as a factor of 3. We observed a sudden decrease in intensity levels after 2015 March, which we attribute to decreased electron temperatures in the first few kilometers above the surface of the nucleus.« less

Changes in the Physical Environment of the Inner Coma of 67P/Churyumov-Gerasimenko with Decreasing Heliocentric Distance

NASA Astrophysics Data System (ADS)

Bodewits, D.; Lara, L. M.; A'Hearn, M. F.; La Forgia, F.; Gicquel, A.; Kovacs, G.; Knollenberg, J.; Lazzarin, M.; Lin, Z.-Y.; Shi, X.; Snodgrass, C.; Tubiana, C.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Barucci, M. A.; Bertaux, J.-L.; Bertini, I.; Boudreault, S.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutiérrez, P. J.; Güttler, C.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Kramm, J.-R.; Kührt, E.; Küppers, M.; López-Moreno, J. J.; Marzari, F.; Naletto, G.; Oklay, N.; Thomas, N.; Toth, I.; Vincent, J.-B.

2016-11-01

The Wide Angle Camera of the OSIRIS instrument on board the Rosetta spacecraft is equipped with several narrow-band filters that are centered on the emission lines and bands of various fragment species. These are used to determine the evolution of the production and spatial distribution of the gas in the inner coma of comet 67P with time and heliocentric distance, here between 2.6 and 1.3 au pre-perihelion. Our observations indicate that the emission observed in the OH, O I, CN, NH, and NH2 filters is mostly produced by dissociative electron impact excitation of different parent species. We conclude that CO2 rather than H2O is a significant source of the [O I] 630 nm emission. A strong plume-like feature observed in the CN and O I filters is present throughout our observations. This plume is not present in OH emission and indicates a local enhancement of the CO2/H2O ratio by as much as a factor of 3. We observed a sudden decrease in intensity levels after 2015 March, which we attribute to decreased electron temperatures in the first few kilometers above the surface of the nucleus.

The distribution of gas and ions in the inner coma of 67P/Churyumov-Gerasimenko between 3 AU before and after its perihelion

NASA Astrophysics Data System (ADS)

Bodewits, Dennis; Lara, Luisa; La Forgia, Fiorangela; A'Hearn, Michael F.; Knollenberg, Jörg; Lazzarin, Monica; Li, Zhong-Yi; Osiris Team

2016-10-01

Rosetta explored a regime not accessible before: the inner coma of a low-activity comet at a large range of heliocentric distances. The Wide Angle Camera (WAC) of the OSIRIS instrument on board the Rosetta spacecraft is equipped with several narrowband filters that are centered on the emission lines and bands of various molecules and ions. These filters center on fragment species that are relatively bright and that have been used for numerous comet studies from the ground (e.g. A'Hearn et al. 1995). Surprisingly, we found that outside 2 AU pre-perihelion, the emission in the filters was dominated by emission from dissociative electron impact excitation (Bodewits et al. 2016). Closer to perihelion, higher gas densities reduced electron temperatures in the inner coma and photo-processes drove much if not most of the emission from the comet. Our observations allowed us to study changes in the physical environment of the inner coma, and Rosetta's excursions as far as 1000 km from the surface allowed us to study different regions of the coma.In this contribution, we will summarize the results of our OSIRIS observations from approximately 3 AU before to 3 AU after perihelion.

Climate-relevant properties of diesel particulate emissions: results from a piggyback study in Bangkok, Thailand.

PubMed

Subramanian, R; Winijkul, Ekbordin; Bond, Tami C; Thiansathit, Worrarat; Oanh, Nguyen Thi Kim; Paw-armart, Ittipol; Duleep, K G

2009-06-01

A "piggyback" approach is used to characterize aerosol emissions to obtain input for large-scale models of atmospheric transport. Particulate and gaseous emissions from diesel trucks, light-duty vehicles, and buses were measured by the Bangkok Pollution Control Department as part of the Developing Integrated Emissions Strategies for Existing Land Transport (DIESEL) project. We added filter-based measurements of carbonaceous composition, particulate light absorption, and water uptake. For 88 "normal" diesel vehicles (PM emission rate < 4.7 g/kg), our best estimate of the average PM2.5 emission rate is 2.2 +/- 0.5 g/kg, whereas for 15 high emitters, it is 8.4 +/- 1.9 g/kg. The effect of Euro standards on PM emission rates was apparent for heavy-duty vehicles, but not for light-duty vehicles. Carbonaceous composition appears relatively consistent, with particulate (artifact-corrected) OC at 17 +/- 1% and EC at 40 +/- 8% of PM for 103 pickups, vans, heavy-duty trucks and buses. The median absorption cross-section for EC is 10.5 m2/g at 532 nm. The history of average emission rate and chemical composition during the project suggests that about 25 vehicles can provide a regional PM emission rate for normal vehicles. Other studies such as remote sensing measurements will be required to estimate the important contribution of high-emitting vehicles.

Impacts of continuously regenerating trap and particle oxidation catalyst on the NO2 and particulate matter emissions emitted from diesel engine.

PubMed

Liu, Zhihua; Ge, Yunshan; Tan, Jianwei; He, Chao; Shah, Asad Naeem; Ding, Yan; Yu, Linxiao; Zhao, Wei

2012-01-01

Two continuously regenerating diesel particulate filter (CRDPF) with different configurations and one particles oxidation catalyst (POC) were employed to perform experiments in a controlled laboratory setting to evaluate their effects on NO2, smoke and particle number emissions. The results showed that the application of the after-treatments increased the emission ratios of NO2/NOx significantly. The results of smoke emissions and particle number (PN) emissions indicated that both CRDPFs had sufficient capacity to remove more than 90% of total particulate matter (PM) and more than 97% of solid particles. However, the POC was able to remove the organic components of total PM, and only partially to remove the carbonaceous particles with size less than 30 nm. The negligible effects of POC on larger particles were observed due to its honeycomb structure leads to an inadequate residence time to oxidize the solid particles or trap them. The particles removal efficiencies of CRDPFs had high degree of correlations with the emission ratio of NO2/NOx. The PN emission results from two CRDPFs indicated that more NO2 generating in diesel oxidation catalyst section could obtain the higher removal efficiency of solid particles. However this also increased the risk of NO2 exposure in atmosphere.

Ultra-directional source of longitudinal acoustic waves based on a two-dimensional solid/solid phononic crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morvan, B.; Tinel, A.; Sainidou, R.

2014-12-07

Phononic crystals (PC) can be used to control the dispersion properties of acoustic waves, which are essential to direct their propagation. We use a PC-based two-dimensional solid/solid composite to demonstrate experimentally and theoretically the spatial filtering of a monochromatic non-directional wave source and its emission in a surrounding water medium as an ultra-directional beam with narrow angular distribution. The phenomenon relies on square-shaped equifrequency contours (EFC) enabling self-collimation of acoustic waves within the phononic crystal. Additionally, the angular width of collimated beams is controlled via the EFC size-shrinking when increasing frequency.

Adsorbents for capturing mercury in coal-fired boiler flue gas.

PubMed

Yang, Hongqun; Xu, Zhenghe; Fan, Maohong; Bland, Alan E; Judkins, Roddie R

2007-07-19

This paper reviews recent advances in the research and development of sorbents used to capture mercury from coal-fired utility boiler flue gas. Mercury emissions are the source of serious health concerns. Worldwide mercury emissions from human activities are estimated to be 1000 to 6000 t/annum. Mercury emissions from coal-fired power plants are believed to be the largest source of anthropogenic mercury emissions. Mercury emissions from coal-fired utility boilers vary in total amount and speciation, depending on coal types, boiler operating conditions, and configurations of air pollution control devices (APCDs). The APCDs, such as fabric filter (FF) bag house, electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD), can remove some particulate-bound and oxidized forms of mercury. Elemental mercury often escapes from these devices. Activated carbon injection upstream of a particulate control device has been shown to have the best potential to remove both elemental and oxidized mercury from the flue gas. For this paper, NORIT FGD activated carbon was extensively studied for its mercury adsorption behavior. Results from bench-, pilot- and field-scale studies, mercury adsorption by coal chars, and a case of lignite-burned mercury control were reviewed. Studies of brominated carbon, sulfur-impregnated carbon and chloride-impregnated carbon were also reviewed. Carbon substitutes, such as calcium sorbents, petroleum coke, zeolites and fly ash were analyzed for their mercury-adsorption performance. At this time, brominated activated carbon appears to be the best-performing mercury sorbent. A non-injection regenerable sorbent technology is briefly introduced herein, and the issue of mercury leachability is briefly covered. Future research directions are suggested.

40 CFR 63.1350 - Monitoring requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... For a negative-pressure or induced-air fabric filter, the bag leak detector must be installed... Section 63.1350 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission...

Filtered epithermal quasi-monoenergetic neutron beams at research reactor facilities.

PubMed

Mansy, M S; Bashter, I I; El-Mesiry, M S; Habib, N; Adib, M

2015-03-01

Filtered neutron techniques were applied to produce quasi-monoenergetic neutron beams in the energy range of 1.5-133keV at research reactors. A simulation study was performed to characterize the filter components and transmitted beam lines. The filtered beams were characterized in terms of the optimal thickness of the main and additive components. The filtered neutron beams had high purity and intensity, with low contamination from the accompanying thermal emission, fast neutrons and γ-rays. A computer code named "QMNB" was developed in the "MATLAB" programming language to perform the required calculations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Second generation OH suppression filters using multicore fibers

NASA Astrophysics Data System (ADS)

Haynes, R.; Birks, T. A.; Bland-Hawthorn, J.; Cruz, J. L.; Diez, A.; Ellis, S. C.; Haynes, D.; Krämer, R. G.; Mangan, B. J.; Min, S.; Murphy, D. F.; Nolte, S.; Olaya, J. C.; Thomas, J. U.; Trinh, C. Q.; Tünnermann, A.; Voigtländer, Christian

2012-09-01

Ground based near-infrared observations have long been plagued by poor sensitivity when compared to visible observations as a result of the bright narrow line emission from atmospheric OH molecules. The GNOSIS instrument recently commissioned at the Australian Astronomical Observatory uses Photonic Lanterns in combination with individually printed single mode fibre Bragg gratings to filter out the brightest OH-emission lines between 1.47 and 1.70μm. GNOSIS, reported in a separate paper in this conference, demonstrates excellent OH-suppression, providing very “clean” filtering of the lines. It represents a major step forward in the goal to improve the sensitivity of ground based near-infrared observation to that possible at visible wavelengths, however, the filter units are relatively bulky and costly to produce. The 2nd generation fibre OH-Suppression filters based on multicore fibres are currently under development. The development aims to produce high quality, cost effective, compact and robust OH-Suppression units in a single optical fibre with numerous isolated single mode cores that replicate the function and performance of the current generation of “conventional” photonic lantern based devices. In this paper we present the early results from the multicore fibre development and multicore fibre Bragg grating imprinting process.

Models for nearly every occasion: Part III - One box decreasing emission models.

PubMed

Hewett, Paul; Ganser, Gary H

2017-11-01

New one box "well-mixed room" decreasing emission (DE) models are introduced that allow for local exhaust or local exhaust with filtered return, as well the recirculation of a filtered (or cleaned) portion of the general room ventilation. For each control device scenario, a steady state and transient model is presented. The transient equations predict the concentration at any time t after the application of a known mass of a volatile substance to a surface, and can be used to predict the task exposure profile, the average task exposure, as well as peak and short-term exposures. The steady state equations can be used to predict the "average concentration per application" that is reached whenever the substance is repeatedly applied. Whenever the beginning and end concentrations are expected to be zero (or near zero) the steady state equations can also be used to predict the average concentration for a single task with multiple applications during the task, or even a series of such tasks. The transient equations should be used whenever these criteria cannot be met. A structured calibration procedure is proposed that utilizes a mass balance approach. Depending upon the DE model selected, one or more calibration measurements are collected. Using rearranged versions of the steady state equations, estimates of the model variables-e.g., the mass of the substance applied during each application, local exhaust capture efficiency, and the various cleaning or filtration efficiencies-can be calculated. A new procedure is proposed for estimating the emission rate constant.

40 CFR 1066.835 - Exhaust emission test procedure for SC03 emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emission measurements. (3) Solar heat load. Simulate solar heating as follows: (i) You may use a metal... measurement procedures specified in §§ 1066.410 through 1066.425, subject to the following exceptions and... you may need to filter the UV region between 280 and 320 nm. (iii) Determine radiant energy intensity...

Fiber-optic apparatus and method for measurement of luminescence and Raman scattering

DOEpatents

Myrick, M.L.; Angel, S.M.

1993-03-16

A dual fiber forward scattering optrode for Raman spectroscopy with the remote ends of the fibers in opposed, spaced relationship to each other to form a analyte sampling space therebetween and the method of measuring Raman spectra utilizing same are described. One optical fiber is for sending an exciting signal to the remote sampling space and, at its remote end, has a collimating microlens and an optical filter for filtering out background emissions generated in the fiber. The other optical fiber is for collecting the Raman scattering signal at the remote sampling space and, at its remote end, has a collimating microlens and an optical filter to prevent the exciting signal from the exciting fiber from entering the collection fiber and to thereby prevent the generation of background emissions in the collecting fiber.

Emission factors for PM2.5, CO, CO2, NOx, SO2 and particle size distributions from the combustion of wood species using a new controlled combustion chamber 3CE.

PubMed

Cereceda-Balic, Francisco; Toledo, Mario; Vidal, Victor; Guerrero, Fabian; Diaz-Robles, Luis A; Petit-Breuilh, Ximena; Lapuerta, Magin

2017-04-15

The objective of this research was to determine emission factors (EF) for particulate matter (PM 2.5 ), combustion gases and particle size distribution generated by the combustion of Eucalyptus globulus (EG), Nothofagus obliqua (NO), both hardwoods, and Pinus radiata (PR), softwood, using a controlled combustion chamber (3CE). Additionally, the contribution of the different emissions stages associated with the combustion of these wood samples was also determined. Combustion experiments were performed using shaving size dried wood (0% humidity). The emission samples were collected with a tedlar bag and sampling cartridges containing quartz fiber filters. High reproducibility was achieved between experiment repetitions (CV<10%, n=3). The EF for PM 2.5 was 1.06gkg -1 for EG, 1.33gkg -1 for NO, and 0.84gkg -1 for PR. Using a laser aerosol spectrometer (0.25-34μm), the contribution of particle emissions (PM 2.5 ) in each stage of emission process (SEP) was sampled in real time. Particle size of 0.265μm were predominant during all stages, and the percentages emitted were PR (33%), EG (29%), and NO (21%). The distributions of EF for PM 2.5 in pre-ignition, flame and smoldering stage varied from predominance of the flame stage for PR (77%) to predominance of the smoldering stage for NO (60%). These results prove that flame phase is not the only stage contributing to emissions and on the contrary, pre-ignition and in especial post-combustion smoldering have also very significant contributions. This demonstrates that particle concentrations measured only in stationary state during flame stage may cause underestimation of emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

Biofiltration for control of volatile organic compounds (VOCS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishop, D.F.; Govind, R.

1995-10-01

Air biofiltration is a promising technology for control of air emissions of biodegradable volatile organic compounds (VOCs). In conjunction with vacuum extraction of soils or air stripping of ground water, it can be used to mineralize VOCs removed from contaminated soil or groundwater. The literature describes three major biological systems for treating contaminated air bioscrubbers, biotrickling filters and biofilters. Filter media can be classified as: bioactive fine or irregular particulates, such as soil, peat, compost or mixtures of these materials; pelletized, which are randomly packed in a bed; and structured, such as monoliths with defined or variable passage size andmore » geometry. The media can be made of sorbing and non-absorbing materials. Non-bioactive pelletized and structured media require recycled solutions of nutrients and buffer for efficient microbial activity and are thus called biotrickling filters. Extensive work has been conducted to improve biofiltration by EPA`s Risk Reduction Engineering Laboratory and the University of Cincinnati in biofilters using pelletized and structured media and improved operational approaches. Representative VOCs in these studies included compounds with a range of aqueous solubilities and octanol-water partition coefficients. The compounds include iso-pentane, toluene, methylene chloride, trichloroethylene (TCE), ethyl benzene, chlorobenzene and perchloroethylene (PCE) and alpha ({alpha}-) pinene. Comparative studies were conducted with peat/compost biofilters using isopentane and {alpha}-pinene. Control studies were also conducted to investigate adsorption/desorption of contaminants on various media using mercuric chloride solution to insure the absence of bioactivity.« less

Estimating air chemical emissions from research activities using stack measurement data.

PubMed

Ballinger, Marcel Y; Duchsherer, Cheryl J; Woodruff, Rodger K; Larson, Timothy V

2013-03-01

Current methods of estimating air emissions from research and development (R&D) activities use a wide range of release fractions or emission factors with bases ranging from empirical to semi-empirical. Although considered conservative, the uncertainties and confidence levels of the existing methods have not been reported. Chemical emissions were estimated from sampling data taken from four research facilities over 10 years. The approach was to use a Monte Carlo technique to create distributions of annual emission estimates for target compounds detected in source test samples. Distributions were created for each year and building sampled for compounds with sufficient detection frequency to qualify for the analysis. The results using the Monte Carlo technique without applying a filter to remove negative emission values showed almost all distributions spanning zero, and 40% of the distributions having a negative mean. This indicates that emissions are so low as to be indistinguishable from building background. Application of a filter to allow only positive values in the distribution provided a more realistic value for emissions and increased the distribution mean by an average of 16%. Release fractions were calculated by dividing the emission estimates by a building chemical inventory quantity. Two variations were used for this quantity: chemical usage, and chemical usage plus one-half standing inventory. Filters were applied so that only release fraction values from zero to one were included in the resulting distributions. Release fractions had a wide range among chemicals and among data sets for different buildings and/or years for a given chemical. Regressions of release fractions to molecular weight and vapor pressure showed weak correlations. Similarly, regressions of mean emissions to chemical usage, chemical inventory, molecular weight, and vapor pressure also gave weak correlations. These results highlight the difficulties in estimating emissions from R&D facilities using chemical inventory data. Air emissions from research operations are difficult to estimate because of the changing nature of research processes and the small quantity and wide variety of chemicals used. Analysis of stack measurements taken over multiple facilities and a 10-year period using a Monte Carlo technique provided a method to quantify the low emissions and to estimate release fractions based on chemical inventories. The variation in release fractions did not correlate well with factors investigated, confirming the complexities in estimating R&D emissions.

Semivolatile Particulate Organic Material Southern Africa during SAFARI 2000

NASA Technical Reports Server (NTRS)

Eatough, D. J.; Eatough, N. L.; Pang, Y.; Sizemore, S.; Kirchstetter, T. W.; Novakov, T.

2005-01-01

During August and September 2000, the University of Washington's Cloud and Aerosol Research Group (CARG) with its Convair-580 research aircraft participated in the Southern African Fire-Atmosphere Research Initiative (SAFARI) 2000 field study in southern Africa. Aboard this aircraft was a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS), which was used to determine semivolatile particulate material with a diffusion denuder sampler. Denuded quartz filters and sorbent beds in series were used to measure nonvolatile and semivolatile materials, respectively. Results obtained with the PC-BOSS are compared to those obtained with conventional quartz-quartz and Teflon-quartz filter pack samplers. Various 10-120 min integrated samples were collected during flights through the h e troposphere, in the atmospheric boundary layer, and in plumes from savanna fires. Significant fine particulate semivolatile organic compounds (SVOC) were found in all samples. The SVOC was not collected by conventional filter pack samplers and therefore would not have been determined in previous studies that used only filter pack samplers. The SVOC averaged 24% of the fine particulate mass in emissions from the fires and 36% of the fine particulate mass in boundary layer samples heavily impacted by aged emissions from savanna fires. Concentrations of fine particulate material in the atmospheric mixed layer heavily impacted by aged savanna frre emissions averaged 130 micrograms per cubic meter. This aerosol was 85% carbonaceous mated.

Environmentally and economically efficient utilization of coal processing waste.

PubMed

Dmitrienko, Margarita A; Strizhak, Pavel A

2017-11-15

High concentrations of hazardous anthropogenic emissions (sulfur, nitrogen and carbon oxides) from solid fuel combustion in coal burning plants cause environmental problems that have been especially pressing over the last 20-30 years. A promising solution to these problems is a switch from conventional pulverized coal combustion to coal-water slurry fuel. In this paper, we pay special attention to the environmental indicators characterizing the combustion of different coal ranks (gas, flame, coking, low-caking, and nonbaking coals) and coal-water slurry fuels based on the coal processing waste - filter cakes. There have been no consistent data so far on the acceptable intervals for the anthropogenic emissions of sulfur (SO x ), nitrogen (NO x ) and carbon (CO, CO 2 ) oxides. Using a specialized combustion chamber and gas analyzing system, we have measured the concentrations of typical coal and filter-cake-based CWS combustion products. We have also calculated the typical combustion heat of the fuels under study and measured the ratio between environmental and energy attributes. The research findings show that the use of filter cakes in the form of CWS is even better than coals in terms of environment and economy. Wide utilization of filter cakes solves many environmental problems: the areas of contaminated sites shrink, anthropogenic emissions decrease, and there is no need to develop new coal mines anymore. Copyright © 2017 Elsevier B.V. All rights reserved.

The contribution of lubricant to the formation of particulate matter with reactivity controlled compression ignition in light-duty diesel engines

DOE PAGES

Storey, John Morse; Curran, Scott; Dempsey, Adam B.; ...

2014-12-25

Reactivity controlled compression ignition (RCCI) has been shown in single- and multi-cylinder engine research to achieve high thermal efficiencies with ultra-low NO X and soot emissions. The nature of the particulate matter (PM) produced by RCCI operation has been shown in recent research to be different than that of conventional diesel combustion and even diesel low-temperature combustion. Previous research has shown that the PM from RCCI operation contains a large amount of organic material that is volatile and semi-volatile. However, it is unclear if the organic compounds are stemming from fuel or lubricant oil. The PM emissions from dual-fuel RCCImore » were investigated in this study using two engine platforms, with an emphasis on the potential contribution of lubricant. Both engine platforms used the same base General Motors (GM) 1.9-L diesel engine geometry. The first study was conducted on a single-cylinder research engine with primary reference fuels (PRFs), n-heptane, and iso-octane. The second study was conducted on a four-cylinder GM 1.9-L ZDTH engine which was modified with a port fuel injection (PFI) system while maintaining the stock direct injection fuel system. Multi-cylinder RCCI experiments were run with PFI gasoline and direct injection of 2-ethylhexyl nitrate (EHN) mixed with gasoline at 5 % EHN by volume. In addition, comparison cases of conventional diesel combustion (CDC) were performed. Particulate size distributions were measured, and PM filter samples were collected for analysis of lube oil components. Triplicate PM filter samples (i.e., three individual filter samples) for both gas chromatography-mass spectroscopy (GC-MS; organic) analysis and X-ray fluorescence (XRF; metals) were obtained at each operating point and queued for analysis of both organic species and lubricant metals. Here, the results give a clear indication that lubricants do not contribute significantly to the formation of RCCI PM.« less

Emission of poly and perfluoroalkyl substances, UV-filters and siloxanes to air from wastewater treatment plants.

PubMed

Shoeib, Mahiba; Schuster, Jasmin; Rauert, Cassandra; Su, Ky; Smyth, Shirley-Anne; Harner, Tom

2016-11-01

The potential of wastewater treatment plants (WWTPs) to act as sources of poly and perfluoroalkyl substances (PFASs), volatile methyl siloxanes (VMSs) and organic UV-filters to the atmosphere was investigated. Target compounds included: PFASs (fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamides/sulfonamidoethanols (FOSAs/FOSEs), perfluroalkyl sulfonic acids (PFSAs) and perfluroalkyl carboxylic acids (PFCAs)), cyclic VMSs (D3 to D6), linear VMSs (L3 to L5) and eight UV-filters. Emissions to air were assessed at eight WWTPs using paired sorbent-impregnated polyurethane foam passive air samplers, deployed during summer 2013 and winter 2014. Samplers were deployed on-site above the active tank and off-site as a reference. Several types of WWTPs were investigated: secondary activated sludge in urban areas (UR-AS), secondary extended aeration in towns (TW-EA) and facultative lagoons in rural areas (RU-LG). The concentrations of target compounds in air were ∼1.7-35 times higher on-site compared to the corresponding off-site location. Highest concentrations in air were observed at UR-AS sites while the lowest were at RU-LG. Higher air concentrations (∼2-9 times) were observed on-site during summer compared to winter, possibly reflecting enhanced volatilization due to higher wastewater temperatures or differences in influent wastewater concentrations. A significant positive correlation was obtained between concentrations in air and WWTP characteristics (influent flow rate and population in the catchment of the WWTP); whereas a weak negative correlation was obtained with hydraulic retention time. Emissions to air were estimated using a simplified dispersion model. Highest emissions to air were seen at the UR-AS locations. Emissions to air (g/year/tank) were highest for VMSs (5000-112,000) followed by UV-filters (16-2000) then ΣPFASs (10-110). Copyright © 2016. Published by Elsevier Ltd.

APBF-DEC NOx Adsorber/DPF Project: Light-Duty Passenger Car Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomazic, D; Tatur, M; Thornton, M

A 1.9L turbo direct injection (TDI) diesel engine was modified to achieve the upcoming Tier 2 Bin 5 emission standard in combination with a NOx adsorber catalyst (NAC) and a diesel particulate filter (DPF). The primary objective for developing this test bed is to investigating the effects of different fuel sulfur contents on the performance of an advanced emission control system (ECS) in a light-duty application. During the development process, the engine-out emissions were minimized by applying a state-of-the-art combustion system in combination with cooled exhaust gas recirculation (EGR). The subsequent calibration effort resulted in emission levels requiring 80-90 percentmore » nitrogen-oxide (NOx) and particulate matter (PM) conversion rates by the corresponding ECS. The strategy development included ean/rich modulation for NAC regeneration, as well as, the desulfurization of the NAC and the regeneration of the DPF. Two slightly different ECS were investigated and calibrated. The initial vehicle results in an Audi A4 station wagon over the federal test procedure (FTP), US 06, and the highway fuel economy test (HFET) cycle indicate the potential of these configuration to meet the future Tier 2 emission standard.« less

Particulate emission abatement for Krakow boiler houses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wysk, R.

1995-12-31

Among the many strategies for improving air quality in Krakow, one possible method is to adapt new and improved emission control technology. This project focuses on such a strategy. In order to reduce dust emissions from coal-fueled boilers, a new device called a Core Separator has been introduced in several boiler house applications. This advanced technology has been successfully demonstrated in Poland and several commercial units are now in operation. Particulate emissions from the Core Separator are typically 3 to 5 times lower than those from the best cyclone collectors. It can easily meet the new standard for dust emissionsmore » which will be in effect in Poland after 1997. The Core Separator is a completely inertial collector and is based on a unique recirculation method. It can effectively remove dust particles below 10 microns in diameter, the so-called PM-10 emissions. Its performance approaches that of fabric filters, but without the attendant cost and maintenance. It is well-suited to the industrial size boilers located in Krakow. Core Separators are now being marketed and sold by EcoInstal, one of the leading environmental firms in Poland, through a cooperative agreement with LSR Technologies.« less

Examples for the importance of radiophysical measurements in clinical phototherapy.

PubMed

Schneider, Lars Alexander; Wlaschek, Meinhard; Dissemond, Joachim; Scharffetter-Kochanek, Karin

2007-05-01

Optimal UV therapy requires regular surveillance of the variables that influence therapeutic success. In daily practice, phototherapy equipment is often operated with an attitude of "autocontrol." This implies that thorough control measurements of the emission spectra and calibration of UV fluences are not routinely performed. For both quality control and patient safety, it is essential to regularly check whether a UV source is providing the right target spectrum with the correct dose to the skin. We have exemplarily taken three UV sources currently used in clinical practice and performed radiophysical measurements, i. e. determined emission spectra, radiation output and correctness of dose calculation. All three sources revealed either a largely inhomogeneous distribution pattern of radiation intensity, variation of radiation intensity over time or insufficient filtering of the UV lamp emission spectrum. Furthermore the dose calculation procedures had to be revised because of significant differences between the estimated and the administered UV doses. Radiophysical measurement of all UV-equipment in clinical use is a simple and effective way to improve the safety and reliability of phototherapy. Such measurements help to uncover technical flaws in radiation sources and prevent unnecessary side effects and UV exposure risks for the patient.

Numerical simulation of DPF filter for selected regimes with deposited soot particles

NASA Astrophysics Data System (ADS)

Lávička, David; Kovařík, Petr

2012-04-01

For the purpose of accumulation of particulate matter from Diesel engine exhaust gas, particle filters are used (referred to as DPF or FAP filters in the automotive industry). However, the cost of these filters is quite high. As the emission limits become stricter, the requirements for PM collection are rising accordingly. Particulate matters are very dangerous for human health and these are not invisible for human eye. They can often cause various diseases of the respiratory tract, even what can cause lung cancer. Performed numerical simulations were used to analyze particle filter behavior under various operating modes. The simulations were especially focused on selected critical states of particle filter, when engine is switched to emergency regime. The aim was to prevent and avoid critical situations due the filter behavior understanding. The numerical simulations were based on experimental analysis of used diesel particle filters.

Fully reconfigurable photonic microwave transversal filter based on digital micromirror device and continuous-wave, incoherent supercontinuum source.

PubMed

Lee, Ju Han; Chang, You Min; Han, Young-Geun; Lee, Sang Bae; Chung, Hae Yang

2007-08-01

The combined use of a programmable, digital micromirror device (DMD) and an ultrabroadband, cw, incoherent supercontinuum (SC) source is experimentally demonstrated to fully explore various aspects on the reconfiguration of a microwave filter transfer function by creating a range of multiwavelength optical filter shapes. Owing to both the unique characteristic of the DMD that an arbitrary optical filter shape can be readily produced and the ultrabroad bandwidth of the cw SC source that is 3 times larger than that of Er-amplified spontaneous emission, a multiwavelength optical beam pattern can be generated with a large number of wavelength filter taps apodized by an arbitrary amplitude window. Therefore various types of high-quality microwave filter can be readily achieved through the spectrum slicing-based photonic microwave transversal filter scheme. The experimental demonstration is performed in three aspects: the tuning of a filter resonance bandwidth at a fixed resonance frequency, filter resonance frequency tuning at a fixed resonance frequency, and flexible microwave filter shape reconstruction.

Analysis of Polarimetric, Photometric, and Spectroscopic Observations of Comet C/1996 Q1 (Tabur)

NASA Astrophysics Data System (ADS)

Kiselev, N. N.; Jockers, K.; Rosenbush, V. K.; Korsun, P. P.

2001-11-01

We present the imaging polarimetry and photometry of Comet C/1996 Q1 (Tabur) obtained on October 10, 1996, with a two-channel focal reducer attached to the 2-m Pik Terskol Observatory telescope through blue (λ4430/44 Å) and red (λ6420/26 Å) continuum filters and through a λ6620/59 Å filter that isolated the NH_2(0.7.0) band. We analyze the λ3600-9300 Å long-slit spectrograms of the comet taken on October 5-6, 1996, with the 2.6-m Crimean Astrophysical Observatory telescope. The NH_2(0.8.0) λ6408 Å emission and an unidentified λ6428 Å emission were found to fall within the pass band of the red filter. The blue filter transmits weak unidentified emissions at λ4424-4444 Å and partially C_2(λ4360 Å). Correction for the depolarizing effect of molecular emissions resulted in an increase of the dust polarization by 2-4% in the near-nucleus region and by almost a factor of 2 in the outer coma regions. However, the polarization and color differences between different coma regions remained even after correction for the contribution of emissions. We found no dust polarization difference between the gas comet Tabur and the dust comet C/1988 A1 (Liller), which are believed to be fragments of a common parent comet. The NH_2coma was found to be elongated perpendicular to the comet radius vector. The causes of the spatial asymmetry in the NH_2molecular distribution are yet to be established. We study the evolution of activity and the spatial distribution of dust brightness, polarization, and color in the comet. We consider a taxonomic classification of gas and dust comets according to dust polarization properties. The polarization differences between dust and gas comets at large phase angles are most likely related both to the actual differences in dust and to the effect of molecular emissions, nuclear gas- and dust-production rates and to the evolution of grain properties with distance from the nucleus.

Performance of Particulate Containment at Nanotechnology Workplaces

PubMed Central

Lo, Li-Ming; Tsai, Candace S.-J.; Dunn, Kevin H.; Hammond, Duane; Marlow, David; Topmiller, Jennifer; Ellenbecker, Michael

2015-01-01

The evaluation of engineering controls for the production or use of carbon nanotubes (CNTs) was investigated at two facilities. These controls assessments are necessary to evaluate the current status of control performance and to develop proper control strategies for these workplaces. The control systems evaluated in these studies included ventilated enclosures, exterior hoods, and exhaust filtration systems. Activity-based monitoring with direct-reading instruments and filter sampling for microscopy analysis were used to evaluate the effectiveness of control measures at study sites. Our study results showed that weighing CNTs inside the biological safety cabinet can have a 37% reduction on the particle concentration in the worker’s breathing zone, and produce a 42% lower area concentration outside the enclosure. The ventilated enclosures used to reduce fugitive emissions from the production furnaces exhibited good containment characteristics when closed, but they failed to contain emissions effectively when opened during product removal/harvesting. The exhaust filtration systems employed for exhausting these ventilated enclosures did not provide promised collection efficiencies for removing engineered nanomaterials from furnace exhaust. The exterior hoods were found to be a challenge for controlling emissions from machining nanocomposites: the downdraft hood effectively contained and removed particles released from the manual cutting process, but using the canopy hood for powered cutting of nanocomposites created 15%–20% higher ultrafine (<500 nm) particle concentrations at the source and at the worker’s breathing zone. The microscopy analysis showed that CNTs can only be found at production sources but not at the worker breathing zones during the tasks monitored. PMID:26705393

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

PubMed Central

2014-01-01

Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions. PMID:24621126

Detection of microstructural defects in chalcopyrite Cu(In,Ga)Se2 solar cells by spectrally-filtered electroluminescence

NASA Astrophysics Data System (ADS)

Skvarenina, L.; Gajdos, A.; Macku, R.; Skarvada, P.

2017-12-01

The aim of this research is to detect and localize microstructural defects by using an electrically excited light emission from a forward/reverse-bias stressed pn-junction in thin-film Cu(In; Ga)Se2 solar cells with metal wrap through architecture. A different origin of the local light emission from intrinsic/extrinsic imperfections in these chalcopyrite-based solar cells can be distinguished by a spectrally-filtered electroluminescence mapping. After a light emission mapping and localization of the defects in a macro scale is performed a micro scale exploration of the solar cell surface by a scanning electron microscope which follows the particular defects obtained by an electroluminescence. In particular, these macroscopic/microscopic examinations are performed independently, then the searching of the corresponding defects in the micro scale is rather difficult due to a diffused light emission obtained from the macro scale localization. Some of the defects accompanied by a highly intense light emission very often lead to a strong local overheating. Therefore, the lock-in infrared thermography is also performed along with an electroluminescence mapping.

Astronomy with the Color Blind

ERIC Educational Resources Information Center

Smith, Donald A.; Melrose, Justyn

2014-01-01

The standard method to create dramatic color images in astrophotography is to record multiple black and white images, each with a different color filter in the optical path, and then tint each frame with a color appropriate to the corresponding filter. When combined, the resulting image conveys information about the sources of emission in the…

Using water raman intensity to determine the effective excitation and emission path lengths of fluorophotometers for correcting fluorescence inner filter effect

USDA-ARS?s Scientific Manuscript database

Fluorescence and Raman inner filter effects (IFE) cause spectral distortion and nonlinearity between spectral signal intensity with increasing analyte concentration. Convenient and effective correction of fluorescence IFE has been an active research goal for decades. Presented herein is the finding ...

AMERICAN AIR FILTER KINPACTOR 10 X 56 VENTURI SCRUBBER EVALUATION

EPA Science Inventory

The report gives results of an evaluation of an American Air Filter Kinpactor 10 x 56 venturi scrubber, operating on emissions from a large borax fusing furnace. Average total efficiency was 97.5% during the test period. The venturi was operated at a pressure drop of 110 cm W. C....

Spectral and angular-selective thermal emission from gallium-doped zinc oxide thin film structures

NASA Astrophysics Data System (ADS)

Sakr, Enas; Bermel, Peter

2017-02-01

Simultaneously controlling both the spectral and angular emission of thermal photons can qualitatively change the nature of thermal radiation, and offers a great potential to improve a broad range of applications, including infrared light sources and thermophotovoltaic (TPV) conversion of waste heat to electricity. For TPV in particular, frequency-selective emission is necessary for spectral matching with a photovoltaic converter, while directional emission is needed to maximize the fraction of emission reaching the receiver at large separation distances. This can allow the photovoltaics to be moved outside vacuum encapsulation. In this work, we demonstrate both directionally and spectrally-selective thermal emission for p-polarization, using a combination of an epsilon-near-zero (ENZ) thin film backed by a metal reflector, a high contrast grating, and an omnidirectional mirror. Gallium-doped zinc oxide is selected as an ENZ material, with cross-over frequency in the near-infrared. The proposed structure relies on coupling guided modes (instead of plasmonic modes) to the ENZ thin film using the high contrast grating. The angular width is thus controlled by the choice of grating period. Other off-directional modes are then filtered out using the omnidirectional mirror, thus enhancing frequency selectivity. Our emitter design maintains both a high view factor and high frequency selectivity, leading to a factor of 8.85 enhancement over a typical blackbody emitter, through a combination of a 22.26% increase in view factor and a 6.88x enhancement in frequency selectivity. This calculation assumes a PV converter five widths away from the same width emitter in 2D at 1573 K.

Emissions of PCDD/Fs, PCBs, and PAHs from a modern diesel engine equipped with catalyzed emission control systems.

PubMed

Laroo, Christopher A; Schenk, Charles R; Sanchez, L James; McDonald, Joseph

2011-08-01

Exhaust emissions of 17 2,3,7,8-substituted chlorinated dibenzo-p-dioxin/furan (CDD/F) congeners, tetra-octa CDD/F homologues, 12 2005 WHO chlorinated biphenyls (CB) congeners, mono-nona CB homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from a model year 2008 Cummins ISB engine were investigated. Testing included configurations composed of different combinations of aftertreatment including a diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), copper zeolite urea selective catalytic reduction (SCR), iron zeolite SCR, and ammonia slip catalyst. Results were compared to a baseline engine out configuration. Testing included the use of fuel that contained the maximum expected chlorine (Cl) concentration of U.S. highway diesel fuel and a Cl level 1.5 orders of magnitude above. Results indicate there is no risk for an increase in polychlorinated dibenzo-p-dioxin/furan and polychlorinated biphenyl emissions from modern diesel engines with catalyzed aftertreatment when compared to engine out emissions for configurations tested in this program. These results, along with PAH results, compare well with similar results from modern diesel engines in the literature. The results further indicate that polychlorinated dibenzo-p-dioxin/furan emissions from modern diesel engines both with and without aftertreatment are below historical values reported in the literature as well as the current inventory value.

Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

NASA Astrophysics Data System (ADS)

Bongers, W. A.; Kasparek, W.; Doelman, N.; van den Braber, R.; van den Brand, H.; Meo, F.; de Baar, M. R.; Amerongen, F. J.; Donné, A. J. H.; Elzendoorn, B. S. Q.; Erckmann, V.; Goede, A. P. H.; Giannone, L.; Grünwald, G.; Hollman, F.; Kaas, G.; Krijger, B.; Michel, G.; Lubyako, L.; Monaco, F.; Noke, F.; Petelin, M.; Plaum, B.; Purps, F.; ten Pierik, J. G. W.; Schüller, C.; Slob, J. W.; Stober, J. K.; Schütz, H.; Wagner, D.; Westerhof, E.; Ronden, D. M. S.

2012-09-01

A CW capable inline electron cyclotron emission (ECE) separation system for feedback control, featuring oversized corrugated waveguides, is commissioned on ASDEX upgrade (AUG). The system is based on a combination of a polarization independent, non-resonant, Mach-Zehnder diplexer equipped with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG.

Kinetic filtering of [18F]Fluorothymidine in positron emission tomography studies

NASA Astrophysics Data System (ADS)

Gray, Katherine R.; Contractor, Kaiyumars B.; Kenny, Laura M.; Al-Nahhas, Adil; Shousha, Sami; Stebbing, Justin; Wasan, Harpreet S.; Coombes, R. Charles; Aboagye, Eric O.; Turkheimer, Federico E.; Rosso, Lula

2010-02-01

[18F]Fluorothymidine (FLT) is a cell proliferation marker that undergoes predominantly hepatic metabolism and therefore shows a high level of accumulation in the liver, as well as in rapidly proliferating tumours. Furthermore, the tracer's uptake is substantial in other organs including the heart. We present a nonlinear kinetic filtering technique which enhances the visualization of tumours imaged with FLT positron emission tomography (FLT-PET). A classification algorithm to isolate cancerous tissue from healthy organs was developed and validated using 29 scan data from patients with locally advanced or metastatic breast cancer. A large reduction in signal from the liver and heart of 80% was observed following application of the kinetic filter, whilst the majority of signal from both primary tumours and metastases was retained. A scan acquisition time of 60 min has been shown to be sufficient to obtain the necessary kinetic data. The algorithm extends utility of FLT-PET imaging in oncology research.

High-Speed Imaging Optical Pyrometry for Study of Boron Nitride Nanotube Generation

NASA Technical Reports Server (NTRS)

Inman, Jennifer A.; Danehy, Paul M.; Jones, Stephen B.; Lee, Joseph W.

2014-01-01

A high-speed imaging optical pyrometry system is designed for making in-situ measurements of boron temperature during the boron nitride nanotube synthesis process. Spectrometer measurements show molten boron emission to be essentially graybody in nature, lacking spectral emission fine structure over the visible range of the electromagnetic spectrum. Camera calibration experiments are performed and compared with theoretical calculations to quantitatively establish the relationship between observed signal intensity and temperature. The one-color pyrometry technique described herein involves measuring temperature based upon the absolute signal intensity observed through a narrowband spectral filter, while the two-color technique uses the ratio of the signals through two spectrally separated filters. The present study calibrated both the one- and two-color techniques at temperatures between 1,173 K and 1,591 K using a pco.dimax HD CMOS-based camera along with three such filters having transmission peaks near 550 nm, 632.8 nm, and 800 nm.

From prompt gamma distribution to dose: a novel approach combining an evolutionary algorithm and filtering based on Gaussian-powerlaw convolutions.

PubMed

Schumann, A; Priegnitz, M; Schoene, S; Enghardt, W; Rohling, H; Fiedler, F

2016-10-07

Range verification and dose monitoring in proton therapy is considered as highly desirable. Different methods have been developed worldwide, like particle therapy positron emission tomography (PT-PET) and prompt gamma imaging (PGI). In general, these methods allow for a verification of the proton range. However, quantification of the dose from these measurements remains challenging. For the first time, we present an approach for estimating the dose from prompt γ-ray emission profiles. It combines a filtering procedure based on Gaussian-powerlaw convolution with an evolutionary algorithm. By means of convolving depth dose profiles with an appropriate filter kernel, prompt γ-ray depth profiles are obtained. In order to reverse this step, the evolutionary algorithm is applied. The feasibility of this approach is demonstrated for a spread-out Bragg-peak in a water target.

Analysis of a long-term measurement of air pollutants (2007-2011) in North China Plain (NCP); Impact of emission reduction during the Beijing Olympic Games.

PubMed

Xu, Ruiguang; Tang, Guiqian; Wang, Yuesi; Tie, Xuexi

2016-09-01

Five years measurements were used to evaluate the effect of emission controls on the changes of air pollutants in Beijing and its surroundings in the NCP during 2008 Olympic Games (2008OG). The major challenge of this study was to filter out the effect of variability of meteorological conditions, when compared the air pollutants during the game to non-game period. We used four-year (2007, 2009-2011) average as the Non-2008OG to smooth the temporal variability caused by meteorological parameters. To study the spatial variability and regional transport, 6 sites (urban, rural, a mega city, a heavy industrial city, and a remote site) were selected. The result showed that the annually meteorological variability was significantly reduced. Such as, in BJ the differences between 2008OG and 5-years averaged values were 2.7% for relative humidity and 0.6% for wind speed. As a result, the anomaly of air pollutants between 2008OG and Non-2008OG can largely attribute to the emission control. The comparison showed that the major pollutants (PM10, PM2.5, NO, NOx) at the 6 sites in 2008OG were consistently lowered. For example, PM2.5 in BJ decreased from 75 to 45 μg/m(3) (40% reduction). However, the emission controls had minor effect on O3 concentrations (1% reduction). In contrast, the O3 precursor (NOx) reduced from 19.7 to 13.2 ppb (33% reduction). The in-sensitivity between NOx and O3 suggested that the O3 formation was under VOCs control condition in NCP, showing that strong VOC emission control is needed in order to significantly reduce O3 concentration in the region. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative Surface Emissivity and Temperature Measurements of a Burning Solid Fuel Accompanied by Soot Formation

NASA Technical Reports Server (NTRS)

Piltch, Nancy D.; Pettegrew, Richard D.; Ferkul, Paul; Sacksteder, K. (Technical Monitor)

2001-01-01

Surface radiometry is an established technique for noncontact temperature measurement of solids. We adapt this technique to the study of solid surface combustion where the solid fuel undergoes physical and chemical changes as pyrolysis proceeds, and additionally may produce soot. The physical and chemical changes alter the fuel surface emissivity, and soot contributes to the infrared signature in the same spectral band as the signal of interest. We have developed a measurement that isolates the fuel's surface emissions in the presence of soot, and determine the surface emissivity as a function of temperature. A commercially available infrared camera images the two-dimensional surface of ashless filter paper burning in concurrent flow. The camera is sensitive in the 2 to 5 gm band, but spectrally filtered to reduce the interference from hot gas phase combustion products. Results show a strong functional dependence of emissivity on temperature, attributed to the combined effects of thermal and oxidative processes. Using the measured emissivity, radiance measurements from several burning samples were corrected for the presence of soot and for changes in emissivity, to yield quantitative surface temperature measurements. Ultimately the results will be used to develop a full-field, non-contact temperature measurement that will be used in spacebased combustion investigations.

Application of filter method for detection of secondary electron emission in the auto-oscillating mode of beam plasma discharge

NASA Astrophysics Data System (ADS)

Balovnev, A. V.; Vizgalov, I. V.; Salahutdinov, G. H.

2016-01-01

In this paper we studied the non-self mode of the auto-oscillation secondary- emission discharge (ASED) in a longitudinal magnetic field with autonomous electron gun to ignite the primary beam-plasma discharge (PPD).

40 CFR 60.273a - Emission monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... following: (1) Inspecting the baghouse for air leaks, torn or broken bags or filter media, or any other....273a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... by a certified visible emission observer and the owner installs and continuously operates a bag leak...

40 CFR 60.273a - Emission monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... following: (1) Inspecting the baghouse for air leaks, torn or broken bags or filter media, or any other....273a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... by a certified visible emission observer and the owner installs and continuously operates a bag leak...

40 CFR 60.273a - Emission monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... following: (1) Inspecting the baghouse for air leaks, torn or broken bags or filter media, or any other....273a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... by a certified visible emission observer and the owner installs and continuously operates a bag leak...

Function and limits of biofilters for the removal of methane in exhaust gases from the pig industry.

PubMed

Veillette, Marc; Girard, Matthieu; Viens, Pascal; Brzezinski, Ryszard; Heitz, Michèle

2012-05-01

The agricultural sector is responsible for an important part of Canadian greenhouse gas (GHG) emissions, 8 % of the 747 Mt eq. CO(2) emitted each year. The pork industry, a key sector of the agrifood industry, has had a rapid growth in Canada since the middle 1980s. For this industry, slurry storage accounts for the major part of methane (CH(4)) emissions, a GHG 25 times higher than carbon dioxide (CO(2)) on a 100-year time horizon. Intending to reduce these emissions, biofiltration, a process effective to treat CH(4) from landfills and coal mines, could be effective to treat CH(4) from the pig industry. Biofiltration is a complex process that requires the understanding of the biological process of CH(4) oxidation and a control of the engineering parameters (filter bed, temperature, etc.). Some biofiltration studies show that this technology could be used to treat CH(4) at a relatively low cost and with a relatively high purification performance.

Assessment of emissions and removal of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) at start-up periods in a hazardous waste incinerator.

PubMed

Karademir, Aykan; Korucu, M Kemal

2013-07-01

A study was conducted to observe the changes in polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) levels and congener profiles in the flue gas of a hazardous waste incinerator during two start-up periods. Flue gas samplings were performed simultaneously through Air Pollution Control Devices (APCDs) (including boiler outlet, electrostatic precipitator (ESP) outlet, wet scrubbers (WS) outlet, and activated carbon (AC) filter outlet) in different combustion temperatures during a planned cold (long) start-up and an unplanned warm (short) start-up. The results showed that PCDD/F concentrations could be elevated during the start-up periods up to levels 3-4 times higher than those observed in the normal operation. Especially lower combustion temperatures in the short start-ups may cause high PCDD/F concentrations in the raw flue gas. Assessment of combustion temperatures and Furans/Dioxins values indicated that surface-catalyzed de novo synthesis was the dominant pathway in the formation of PCDD/Fs in the combustion units. PCDD/F removal efficiencies of Air Pollution Control Devices suggested that formation by de novo synthesis existed in ESP also when in operation, leading to increase of gaseous phase PCDD/Fs in ESP Particle-bound PCDD/Fs were removed mainly by ESP and WS, while gaseous phase PCDD/Fs were removed by WS, and more efficiently by AC filter. This paper evaluates PCDD/F emissions and removal performances of APCDs (ESP, wet scrubbers, and activated carbon) during two start-up periods in an incinerator. The main implications are the following: (1) start-up periods increase PCDD/F emissions up to 2-3 times in the incinerator; (2) low combustion temperatures in start-ups cause high PCDD/F emissions in raw gas; (3) formation of PCDD/Fs by de novo synthesis occurs in ESP; (4) AC is efficient in removing gaseous PCDD/Fs, but may increase particle-bound ones; and (5) scrubbers remove both gaseous and particle-bound PCDD/Fs efficiently.

Particle loading rates for HVAC filters, heat exchangers, and ducts.

PubMed

Waring, M S; Siegel, J A

2008-06-01

The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma.

PubMed

Marshall, F J; Radha, P B

2014-11-01

A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.

On-sky characterisation of the VISTA NB118 narrow-band filters at 1.19 μm

NASA Astrophysics Data System (ADS)

Milvang-Jensen, Bo; Freudling, Wolfram; Zabl, Johannes; Fynbo, Johan P. U.; Møller, Palle; Nilsson, Kim K.; McCracken, Henry Joy; Hjorth, Jens; Le Fèvre, Olivier; Tasca, Lidia; Dunlop, James S.; Sobral, David

2013-12-01

Observations of the high redshift Universe through narrow-band filters have proven very successful in the last decade. The 4-m VISTA telescope, equipped with the wide-field camera VIRCAM, offers a major step forward in wide-field near-infrared imaging, and in order to utilise VISTA's large field-of-view and sensitivity, the Dark Cosmology Centre provided a set of 16 narrow-band filters for VIRCAM. These NB118 filters are centered at a wavelength near 1.19 μm in a region with few airglow emission lines. The filters allow the detection of Hα emitters at z = 0.8, Hβ and [O iii] emitters at z ≈ 1.4, [O ii] emitters at z = 2.2, and Lyα emitters at z = 8.8. Based on guaranteed time observations of the COSMOS field we here present a detailed description and characterization of the filters and their performance. In particular we provide sky-brightness levels and depths for each of the 16 detector/filter sets and find that some of the filters show signs of some red-leak. We identify a sample of 2 × 103 candidate emission-line objects in the data. Cross-correlating this sample with a large set of galaxies with known spectroscopic redshifts we determine the "in situ" passbands of the filters and find that they are shifted by about 3.5 - 4 nm (corresponding to 30% of the filter width) to the red compared to the expectation based on the laboratory measurements. Finally, we present an algorithm to mask out persistence in VIRCAM data. Scientific results extracted from the data will be presented separately. Based on observations collected at the European Southern Observatory, Chile, as part of programme 284.A-5026 (VISTA NB118 GTO, PI Fynbo) and 179.A-2005 (UltraVISTA, PIs Dunlop, Franx, Fynbo, & Le Fèvre).

Reflective Filters Design for Self-Filtering Narrowband Ultraviolet Imaging Experiment Wide-Field Surveys (NUVIEWS) Project

NASA Technical Reports Server (NTRS)

Park, Jung- Ho; Kim, Jongmin; Zukic, Muamer; Torr, Douglas G.

1994-01-01

We report the design of multilayer reflective filters for the self-filtering cameras of the NUVIEWS project. Wide angle self-filtering cameras were designed to image the C IV (154.9 nm) line emission, and H2 Lyman band fluorescence (centered at 161 nm) over a 20 deg x 30 deg field of view. A key element of the filter design includes the development of pi-multilayers optimized to provide maximum reflectance at 154.9 nm and 161 nm for the respective cameras without significant spectral sensitivity to the large cone angle of the incident radiation. We applied self-filtering concepts to design NUVIEWS telescope filters that are composed of three reflective mirrors and one folding mirror. The filters with narrowband widths of 6 and 8 rim at 154.9 and 161 nm, respectively, have net throughputs of more than 50 % with average blocking of out-of-band wavelengths better than 3 x 10(exp -4)%.

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

PubMed

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

Scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and aerosol time-of-flight mass spectrometry (ATOFMS) single particle analysis of metallurgy plant emissions.

PubMed

Arndt, J; Deboudt, K; Anderson, A; Blondel, A; Eliet, S; Flament, P; Fourmentin, M; Healy, R M; Savary, V; Setyan, A; Wenger, J C

2016-03-01

The chemical composition of single particles deposited on industrial filters located in three different chimneys of an iron-manganese (Fe-Mn) alloy manufacturing plant have been compared using aerosol time-of-flight mass spectrometry (ATOFMS) and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). Very similar types of particles were observed using both analytical techniques. Calcium-containing particles dominated in the firing area of the sintering unit, Mn and/or Al-bearing particles were observed at the cooling area of the sintering unit, while Mn-containing particles were dominant at the smelting unit. SEM-EDX analysis of particles collected downstream of the industrial filters showed that the composition of the particles emitted from the chimneys is very similar to those collected on the filters. ATOFMS analysis of ore samples was also performed to identify particulate emissions that could be generated by wind erosion and manual activities. Specific particle types have been identified for each emission source (chimneys and ore piles) and can be used as tracers for source apportionment of ambient PM measured in the vicinity of the industrial site. Copyright © 2015 Elsevier Ltd. All rights reserved.

A rapid excitation-emission matrix fluorometer utilizing supercontinuum white light and acousto-optic tunable filters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wenbo; Department of Dermatology and Skin Science, University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8; Department of Biomedical Engineering, University of British Columbia, KAIS 5500, 2332 Main Mall, Vancouver, British Columbia V6T 1Z4

Scanning speed and coupling efficiency of excitation light to optic fibres are two major technical challenges that limit the potential of fluorescence excitation-emission matrix (EEM) spectrometer for on-line applications and in vivo studies. In this paper, a novel EEM system, utilizing a supercontinuum white light source and acousto-optic tunable filters (AOTFs), was introduced and evaluated. The supercontinuum white light, generated by pumping a nonlinear photonic crystal fiber with an 800 nm femtosecond laser, was efficiently coupled into a bifurcated optic fiber bundle. High speed EEM spectral scanning was achieved using AOTFs both for selecting excitation wavelength and scanning emission spectra.more » Using calibration lamps (neon and mercury argon), wavelength deviations were determined to vary from 0.18 nm to −0.70 nm within the spectral range of 500–850 nm. Spectral bandwidth for filtered excitation light broadened by twofold compared to that measured with monochromatic light between 650 nm and 750 nm. The EEM spectra for methanol solutions of laser dyes were successfully acquired with this rapid fluorometer using an integration time of 5 s.« less

Absolute Soft X-ray Emission Measurements at the Nike Laser

NASA Astrophysics Data System (ADS)

Weaver, J.; Atkin, R.; Boyer, C.; Colombant, D.; Feldman, U.; Fielding, D.; Gardner, J.; Holland, G.; Klapisch, M.; Mostovych, A. N.; Obenscain, S.; Seely, J. F.

2002-11-01

Recent experiments at the Nike laser facility have demonstrated that, when a low intensity prepulse ( 2main laser intensity) is used to heat a thin Au or Pd coating on a planar CH target, the growth of non-uniformities due to laser imprint can be reduced from the growth observed for an uncoated CH target. The absolute radiation intensity in the soft x-ray region (0.1-1 keV) has a important role in the energy balance for layered targets. There is an ongoing effort to characterize the soft x-ray emission using an absolutely calibrated transmission grating spectrometer and filtered diode modules. Measurements of the angular distribution of the emission from unlayered solid targets (Au, Pd, CH) have recently been made using an array of moveable filtered diode modules. The data from the angular distribution studies will be presented. A new absolutely calibrated, time-resolving transmission grating spectrometer has been installed at the Nike. The new version has improved spectral resolution, selectable transmission filters, and the potential for simultaneous temporal, spatial, and spectral resolution. Preliminary data from the new spectrometer will be presented and future experiments will be briefly discussed. *Work was supported by DoE

Removal of residual particulate matter from filter media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almlie, Jay C.; Miller, Stanley J.

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Removal of residual particulate matter from filter media

DOEpatents

Almlie, Jay C; Miller, Stanley J

2014-11-11

A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

PubMed

Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

2016-10-01

The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality. © 2016 John Wiley & Sons Ltd.

Fine particle and organic vapor emissions from staged tests of an in-use aircraft engine

NASA Astrophysics Data System (ADS)

Presto, Albert A.; Nguyen, Ngoc T.; Ranjan, Manish; Reeder, Aaron J.; Lipsky, Eric M.; Hennigan, Christopher J.; Miracolo, Marissa A.; Riemer, Daniel D.; Robinson, Allen L.

2011-07-01

Staged tests were conducted to measure the particle and vapor emissions from a CFM56-2B1 gas-turbine engine mounted on a KC-135T Stratotanker airframe at different engine loads. Exhaust was sampled using a rake inlet installed 1-m downstream of the engine exit plane of a parked and chocked aircraft and a dilution sampler and portable smog chamber were used to investigate the particulate matter (PM) emissions. Total fine PM mass emissions were highest at low (4%) and high (85%) load and lower at intermediate loads (7% and 30%). PM mass emissions at 4% load are dominated by organics, while at 85% load elemental carbon is dominant. Quantifying the primary organic aerosol (POA) emissions is complicated by substantial filter sampling artifacts. Partitioning experiments reveal that the majority of the POA is semivolatile; for example, the POA emission factor changed by a factor of two when the background organic aerosol concentration was increased from 0.7 to 4 μg m -3. Therefore, one cannot define a single non-volatile PM emission factor for aircraft exhaust. The gas- and particle-phase organic emissions were comprehensively characterized by analyzing canister, sorbent and filter samples with gas-chromatography/mass-spectrometry. Vapor-phase organic emissions are highest at 4% load and decrease with increasing load. Low-volatility organics (less volatile than a C 12n-alkane) contributed 10-20% of the total organic emissions. The low-volatility organic emissions contain signatures of unburned fuel and aircraft lubricating oil but are dominated by an unresolved complex mixture (UCM) of presumably branched and cyclic alkanes. Emissions at all loads contain more low-volatility organic vapors than POA; thus secondary organic aerosol formation in the aging plume will likely exceed POA emissions.

40 CFR 63.9804 - What are my monitoring system installation, operation, and maintenance requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... pressure or induced air fabric filters, the bag leak detector must be installed downstream of the fabric... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air...

High spatial resolution upgrade of the electron cyclotron emission radiometer for the DIII-D tokamak.

PubMed

Truong, D D; Austin, M E

2014-11-01

The 40-channel DIII-D electron cyclotron emission (ECE) radiometer provides measurements of Te(r,t) at the tokamak midplane from optically thick, second harmonic X-mode emission over a frequency range of 83-130 GHz. The frequency spacing of the radiometer's channels results in a spatial resolution of ∼1-3 cm, depending on local magnetic field and electron temperature. A new high resolution subsystem has been added to the DIII-D ECE radiometer to make sub-centimeter (0.6-0.8 cm) resolution Te measurements. The high resolution subsystem branches off from the regular channels' IF bands and consists of a microwave switch to toggle between IF bands, a switched filter bank for frequency selectivity, an adjustable local oscillator and mixer for further frequency down-conversion, and a set of eight microwave filters in the 2-4 GHz range. Higher spatial resolution is achieved through the use of a narrower (200 MHz) filter bandwidth and closer spacing between the filters' center frequencies (250 MHz). This configuration allows for full coverage of the 83-130 GHz frequency range in 2 GHz bands. Depending on the local magnetic field, this translates into a "zoomed-in" analysis of a ∼2-4 cm radial region. Expected uses of these channels include mapping the spatial dependence of Alfven eigenmodes, geodesic acoustic modes, and externally applied magnetic perturbations. Initial Te measurements, which demonstrate that the desired resolution is achieved, are presented.

Effects of the updated national emission regulation in China on circulating fluidized bed boilers and the solutions to meet them.

PubMed

Li, Jingji; Yang, Hairui; Wu, Yuxin; Lv, Junfu; Yue, Guangxi

2013-06-18

The advantage of circulating fluidized bed (CFB) boilers in China is their ability to utilize low rank coal with low cost emission control. However, the new National Emission Regulation (NER) issued in early 2012 brings much more stringent challenges on the CFB industries, which also causes much attention from other countries. Based on the principle of a CFB boiler and previous operating experience, it is possible for the CFB boilers to meet the new NER and maintain the advantage of low cost emission control, while, more influences should be considered in their design and operation. To meet the requirement of the new NER, the fly ash collector should adopt a bag house or combination of electrostatic precipitator and bag filter to ensure dust emissions of less than 30 mg · Nm(-3). For SO2 emission control, the bed temperature should be strictly lower than 900 °C to maintain high reactivity and pores. The limestone particle size distribution should be ranged within a special scope to optimize the residence time and gas-solid reaction. At the same time, the injecting point should be optimized to ensure fast contact of lime with oxygen. In such conditions, the desulfurization efficiency could be increased more than 90%. For lower sulfur content fuels (<1.5%, referred value based on the heating value of standard coal of China), increasing Ca/S enough could decrease SO2 emissions lower than that of the new NER, 100 mg · Nm(-3). For fuels with sulfur content higher than 1.5%, some simplified systems for flue gas desulfurization, such as flash dryer absorber (FDA), are needed. And the NOx emissions of a CFB can be controlled to less than 100 mg · Nm(-3) without any equipment at a bed temperature lower than 900 °C for fuels with low volatiles content (<12%), while for fuels with high volatiles, selective non-catalytic reduction (SNCR) should be considered. Due to the unique temperature in CFB as well as the circulating ash, the efficiency of SNCR could reach as high as 70%. The Hg emission of CFB is very low for the new NER due to its innate property.

Dynamic properties of micro-magnetic noise in soft ferromagnetic materials

NASA Astrophysics Data System (ADS)

Stupakov, A.; Perevertov, A.

2018-06-01

Dynamic response of magnetic hysteresis, magnetic Barkhausen noise and magneto-acoustic emission in a soft ribbon and electrical steels was studied comprehensively. The measurements were performed under controllable magnetization conditions: sinusoidal/triangular waveforms of the magnetic induction and a triangular waveform of the magnetic field. Magnetizing frequency was varied in a wide range: fmag = 0.5 - 500 and 0.5-100 Hz for the ribbon and the electrical steels, respectively. Magnetization amplitude was fixed on a near-saturation level Hmax ≃ 100 A/m. Barkhausen noise signal was detected by a sample-wrapping/surface-mounted coil and differently filtered. It was found that intensity of the Barkhausen noise rises approximately as a square root function of the magnetizing frequency. Whereas, level of the magneto-acoustic emission follows the hysteresis loss trend with an additional linear term (classical loss component).

On the development of a methodology for extensive in-situ and continuous atmospheric CO2 monitoring

NASA Astrophysics Data System (ADS)

Wang, K.; Chang, S.; Jhang, T.

2010-12-01

Carbon dioxide is recognized as the dominating greenhouse gas contributing to anthropogenic global warming. Stringent controls on carbon dioxide emissions are viewed as necessary steps in controlling atmospheric carbon dioxide concentrations. From the view point of policy making, regulation of carbon dioxide emissions and its monitoring are keys to the success of stringent controls on carbon dioxide emissions. Especially, extensive atmospheric CO2 monitoring is a crucial step to ensure that CO2 emission control strategies are closely followed. In this work we develop a methodology that enables reliable and accurate in-situ and continuous atmospheric CO2 monitoring for policy making. The methodology comprises the use of gas filter correlation (GFC) instrument for in-situ CO2 monitoring, the use of CO2 working standards accompanying the continuous measurements, and the use of NOAA WMO CO2 standard gases for calibrating the working standards. The use of GFC instruments enables 1-second data sampling frequency with the interference of water vapor removed from added dryer. The CO2 measurements are conducted in the following timed and cycled manner: zero CO2 measurement, two standard CO2 gases measurements, and ambient air measurements. The standard CO2 gases are calibrated again NOAA WMO CO2 standards. The methodology is used in indoor CO2 measurements in a commercial office (about 120 people working inside), ambient CO2 measurements, and installed in a fleet of in-service commercial cargo ships for monitoring CO2 over global marine boundary layer. These measurements demonstrate our method is reliable, accurate, and traceable to NOAA WMO CO2 standards. The portability of the instrument and the working standards make the method readily applied for large-scale and extensive CO2 measurements.

Investigation of the Effects of Biodiesel-based Na on Emissions Control Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brookshear, D. William; Nguyen, Ke; Toops, Todd J

2012-01-01

A single-cylinder diesel engine was used to investigate the impact of biodiesel-based Na on emissions control components using specially blended 20% biodiesel fuel (B20). The emissions control components investigated were a diesel oxidation catalyst (DOC), a Cu-zeolite-based NH{sub 3}-SCR (selective catalytic reduction) catalyst, and a diesel particulate filter (DPF). Both light-duty vehicle, DOC-SCR-DPF, and heavy-duty vehicle, DOC-DPF-SCR, emissions control configurations were employed. The accelerated Na aging is achieved by introducing elevated Na levels in the fuel, to represent full useful life exposure, and periodically increasing the exhaust temperature to replicate DPF regeneration. To assess the validity of the implemented acceleratedmore » Na aging protocol, engine-aged lean NO{sub x} traps (LNTs), DOCs and DPFs are also evaluated. To fully characterize the impact on the catalytic activity the LNT, DOC and SCR catalysts were evaluated using a bench flow reactor. The evaluation of the aged DOC samples and LNT show little to no deactivation as a result of Na contamination. However, the SCR in the light-duty configuration (DOC-SCR-DPF) was severely affected by Na contamination, especially when NO was the only fed NO{sub x} source. In the heavy-duty configuration (DOC-DPF-SCR), no impact is observed in the SCR NO{sub x} reduction activity. Electron probe micro-analysis (EPMA) reveals that Na contamination on the LNT, DOC, and SCR samples is present throughout the length of the catalysts with a higher concentration on the washcoat surface. In both the long-term engine-aged DPF and the accelerated Na-aged DPFs, there is significant Na ash present in the upstream channels; however, in the engine-aged sample lube oil-based ash is the predominant constituent.« less

CO2 emissions driven by wind are produced at global scale

NASA Astrophysics Data System (ADS)

Rosario Moya, M.; Sánchez-Cañete, Enrique P.; Kowalski, Andrew S.; Serrano-Ortiz, Penélope; López-Ballesteros, Ana; Oyonarte, Cecilio; Domingo, Francisco

2017-04-01

As an important tool for understanding and monitoring ecosystem dynamics at ecosystem level, the eddy covariance (EC) technique allows the assessment of the diurnal and seasonal variation of the net ecosystem exchange (NEE). Despite the high temporal resolution data, there are still many processes (in addition to photosynthesis and respiration) that, although they are being monitored, have been neglected. Only a few authors have studied anomalous CO2 emissions (non biological), and have related them to soil ventilation, photodegradation or geochemical processes. The aims of this study are: 1) to identify anomalous daytime CO2 emissions in different ecosystems distributed around the world, 2) to determine the meteorological variables that influence these emissions, and 3) to explore the potential processes which can be involved. We have studied EC data together with other meteorological ancillary variables obtained from the FLUXNET database and have found more than 50 sites with anomalous CO2 emissions in different ecosystem types such as grasslands, croplands or savannas. Data were filtered according to the FLUXNET quality control flags (only data with maximum quality were used, i.e. control flag equal to 0) and daytime (shortwave radiation incoming > 50 W m-2). Partial Spearman correlation analyses were performed between NEE and ancillary data: air temperature, vapour pressure deficit, soil temperature, precipitation, atmospheric pressure, soil water content, incoming photosynthetic photon flux density, friction velocity and net radiation. When necessary, ancillary variables were gap-filled using the MDS method (Reichstein et al. 2005). Preliminary results showed strong and highly significant correlations between friction velocity and anomalous CO2 emissions, suggesting that these emissions were mainly produced by ventilation events. Anomalous CO2 emissions were found mainly in arid ecosystems and sites with hot and dry summers. We suggest that anomalous CO2 emissions occur globally and therefore, their contribution to the global NEE requires further investigation in order to better understand its drivers.

TEST METHODS TO CHARACTERIZE PARTICULATE MATTER EMISSIONS AND DEPOSITION RATES IN A RESEARCH HOUSE

EPA Science Inventory

The paper discusses test methods to characterize particulate matter (PM) emissions and deposition rates in a research house. In a room in the research house, specially configured for PM source testing, a high-efficiency particulate air (HEPA)-filtered air supply system, used for...

40 CFR 63.8600 - What are my monitoring installation, operation, and maintenance requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... compartment or cell. (7) For negative pressure or induced air fabric filters, the bag leak detector must be... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for...

Developing a Method for Resolving NOx Emission Inventory Biases Using Discrete Kalman Filter Inversion, Direct Sensitivities, and Satellite-Based Columns

EPA Science Inventory

An inverse method was developed to integrate satellite observations of atmospheric pollutant column concentrations and direct sensitivities predicted by a regional air quality model in order to discern biases in the emissions of the pollutant precursors.

40 CFR 63.8600 - What are my monitoring installation, operation, and maintenance requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... compartment or cell. (7) For negative pressure or induced air fabric filters, the bag leak detector must be... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for...

40 CFR 63.8600 - What are my monitoring installation, operation, and maintenance requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... compartment or cell. (7) For negative pressure or induced air fabric filters, the bag leak detector must be... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for...

40 CFR 63.8600 - What are my monitoring installation, operation, and maintenance requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... compartment or cell. (7) For negative pressure or induced air fabric filters, the bag leak detector must be... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for...

Device for separating CO2 from fossil-fueled power plant emissions

DOEpatents

Burchell, Timothy D [Oak Ridge, TN; Judkins, Roddie R [Knoxville, TN; Wilson, Kirk A [Knoxville, TN

2002-04-23

A gas separation device includes an inner conduit, and a concentric outer conduit. An electrically conductive filter media, preferably a carbon fiber composite molecular sieve, is provided in the annular space between the inner conduit and the outer conduit. Gas flows through the inner conduit and the annular space between the inner conduit and the outer conduit, so as to contact the filter media. The filter media preferentially adsorbs at least one constituent of the gas stream. The filter media is regenerated by causing an electric current to flow through the filter media. The inner conduit and outer conduit are preferably electrically conductive whereby the regeneration of the filter media can be electrically stimulated. The invention is particularly useful for the removal of CO.sub.2 from the exhaust gases of fossil-fueled power plants.

Electrically heated particulate filter preparation methods and systems

DOEpatents

Gonze, Eugene V [Pinckney, MI

2012-01-31

A control system that controls regeneration of a particulate filter is provided. The system generally includes a fuel control module that controls injection of fuel into exhaust that passes through the particulate filter. A regeneration module controls current to the particulate filter to initiate regeneration after the fuel has been injected into the exhaust.

Air filters from HVAC systems as possible source of volatile organic compounds (VOC) - laboratory and field assays

NASA Astrophysics Data System (ADS)

Schleibinger, Hans; Rüden, Henning

The emission of volatile organic compounds (VOC) from air filters of HVAC systems was to be evaluated. In a first study carbonyl compounds (14 aldehydes and two ketones) were measured by reacting them with 2,4-dinitrophenylhydrazine (DNPH). Analysis was done by HPLC and UV detection. In laboratory experiments pieces of used and unused HVAC filters were incubated in test chambers. Filters to be investigated were taken from a filter bank of a large HVAC system in the centre of Berlin. First results show that - among those compounds - formaldehyde and acetone were found in higher concentrations in the test chambers filled with used filters in comparison to those with unused filters. Parallel field measurements were carried out at the prefilter and main filter banks of the two HVAC systems. Here measurements were carried out simultaneously before and after the filters to investigate whether those aldehydes or ketones arise from the filter material on site. Formaldehyde and acetone significantly increased in concentration after the filters of one HVAC system. In parallel experiments microorganisms were proved to be able to survive on air filters. Therefore, a possible source of formaldehyde and acetone might be microbes.

Evaluation of Fuel-Borne Sodium Effects on a DOC-DPF-SCR Heavy-Duty Engine Emission Control System: Simulation of Full-Useful Life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lance, Michael; Wereszczak, Andrew; Toops, Todd J.

2016-04-05

For renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1,001 hr using B20 doped with 14 ppm Na. During the study, oxides of nitrogen (NOx) emissions exceeded the engine certification limit of 0.33 g/bhp-hr beforemore » the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals contamination that increased ammonia oxidation, and lowered NOx reduction. Therefore, it was determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Electrically heated particulate filter regeneration methods and systems for hybrid vehicles

DOEpatents

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

2010-10-12

A control system for controlling regeneration of a particulate filter for a hybrid vehicle is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate regeneration. An engine control module controls operation of an engine of the hybrid vehicle based on the control of the current to the particulate filter.

A morphological filter for removing 'Cirrus-like' emission from far-infrared extragalactic IRAS fields

NASA Technical Reports Server (NTRS)

Appleton, P. N.; Siqueira, P. R.; Basart, J. P.

1993-01-01

The presence of diffuse extended IR emission from the Galaxy in the form of the so called 'Galactic Cirrus' emission has hampered the exploration of the extragalactic sky at long IR wavelengths. We describe the development of a filter based on mathematical morphology which appears to be a promising approach to the problem of cirrus removal. The method of Greyscale Morphology was applied to a 100 micron IRAS image of the M81 group of galaxies. This is an extragalactic field which suffers from serious contamination from foreground Galactic 'cirrus'. Using a technique called 'sieving', it was found that the cirrus emission has a characteristic behavior which can be quantified in terms of an average spatial structure spectrum or growth function. This function was then used to attempt to remove 'cirrus' from the entire image. The result was a significant reduction of cirrus emission by an intensity factor of 15 compared with the original input image. The method appears to preserve extended emission in the spatially extended IR disks of M81 and M82 as well as distinguishing fainter galaxies within bright regions of galactic cirrus. The techniques may also be applicable to IR databases obtained with the Cosmic Background Explorer.

Biofiltration of solvent vapors from air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Young-sook.

1993-01-01

For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps andmore » flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.« less

How to Collect National Institute of Standards and Technology (NIST) Traceable Fluorescence Excitation and Emission Spectra.

PubMed

Gilmore, Adam Matthew

2014-01-01

Contemporary spectrofluorimeters comprise exciting light sources, excitation and emission monochromators, and detectors that without correction yield data not conforming to an ideal spectral response. The correction of the spectral properties of the exciting and emission light paths first requires calibration of the wavelength and spectral accuracy. The exciting beam path can be corrected up to the sample position using a spectrally corrected reference detection system. The corrected reference response accounts for both the spectral intensity and drift of the exciting light source relative to emission and/or transmission detector responses. The emission detection path must also be corrected for the combined spectral bias of the sample compartment optics, emission monochromator, and detector. There are several crucial issues associated with both excitation and emission correction including the requirement to account for spectral band-pass and resolution, optical band-pass or neutral density filters, and the position and direction of polarizing elements in the light paths. In addition, secondary correction factors are described including (1) subtraction of the solvent's fluorescence background, (2) removal of Rayleigh and Raman scattering lines, as well as (3) correcting for sample concentration-dependent inner-filter effects. The importance of the National Institute of Standards and Technology (NIST) traceable calibration and correction protocols is explained in light of valid intra- and interlaboratory studies and effective spectral qualitative and quantitative analyses including multivariate spectral modeling.

Spatial-Temporal Mapping of the T Cell Receptor NF-kappaB Signaling Pathway

DTIC Science & Technology

2006-05-30

Lasos), a 700/488-nm excitation filter and a 500– 550-nm emission filter. Multiphoton PA-GFP activation was performed using the Aim software bleach ...Bcl10 was fused to a PA-GFP [65], and MALT1 was fused to the reef coral fluorescent protein, monomeric Kusabira-Orange (mKO) [70]. D10 T-cells

40 CFR 60.4850 - What operating limits and requirements must I meet and by when?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) If you use a fabric filter to comply with the emission limits, you must install the bag leak detection system specified in §§ 60.4880(b) and 60.4905(b)(3)(i) and operate the bag leak detection system... filter, electrostatic precipitator, or activated carbon injection are listed in Table 3 to this subpart...

40 CFR 1065.308 - Continuous gas analyzer system-response and updating-recording verification-for gas analyzers not...

Code of Federal Regulations, 2011 CFR

2011-07-01

... meets a minimum response time. You may use the results of this test to determine transformation time, t... you use any analog or real-time digital filters during emission testing, you must operate those... the rise time and fall time as needed. You may also configure analog or digital filters before...

Multiple visible emissions by means of up-conversion process in a microstructured tellurite glass optical fiber.

PubMed

Boetti, Nadia G; Lousteau, Joris; Negro, Davide; Mura, Emanuele; Scarpignato, Gerardo; Abrate, Silvio; Milanese, Daniel

2012-02-27

We present a microstructured fiber whose 9 µm diameter core consists in three concentric rings made of three active glasses having different rare earth oxide dopants, Yb3+/Er3+, Yb3+/Tm3+ and Yb3+/Pr3+, respectively. Morphological and optical characterization of the optical fiber are presented. The photoluminescence spectrum is investigated for different pumping conditions using a commercial 980 nm laser diode. Tuning of the RGB (or white light) emission is demonstrated not only by adjusting the pump power but also by using an optical iris as spatial filter which, thanks to the microstructured core, also acts as a spectral filter.

A physical parameter method for the design of broad-band X-ray imaging systems to do coronal plasma diagnostics

NASA Technical Reports Server (NTRS)

Kahler, S.; Krieger, A. S.

1978-01-01

The technique commonly used for the analysis of data from broad-band X-ray imaging systems for plasma diagnostics is the filter ratio method. This requires the use of two or more broad-band filters to derive temperatures and line-of-sight emission integrals or emission measure distributions as a function of temperature. Here an alternative analytical approach is proposed in which the temperature response of the imaging system is matched to the physical parameter being investigated. The temperature response of a system designed to measure the total radiated power along the line of sight of any coronal structure is calculated. Other examples are discussed.

Signal-to-solar clutter calculations of AK-47 muzzle flash at various spectral bandpasses near the potassium D1/D2 doublet

NASA Astrophysics Data System (ADS)

Klett, Karl K., Jr.

2010-04-01

An analysis was performed, using MODTRAN, to determine the best filters to use for detecting the muzzle flash of an AK-47 in daylight conditions in the desert. Filters with bandwidths of 0.05, 0.1, 0.5, 1.0, 3.0, and 5.0 nanometers (nm) were analyzed to understand how the optical bandwidth affects the signal-to-solar clutter ratio. These filters were evaluated near the potassium D1 and D2 doublet emission lines that occur at 769.89 and 766.49 nm respectively that are observed where projectile propellants are used. The maximum spectral radiance, from the AK-47 muzzle flash, is 1.88 x 10-2 W/cm2 str micron, and is approximately equal to the daytime atmospheric spectral radiance. The increased emission, due to the potassium doublet lines, and decreased atmospheric transmission, due to oxygen absorption, combine to create a condition where the signal-to-solar clutter ratio is greater than 1. The 3 nm filter, has a signal-to-solar clutter ratio of 2.09 when centered at 765.37 nm and provides the best combination of both cost and signal sensitivity.

Effects of particulate oxidation catalyst on unregulated pollutant emission and toxicity characteristics from heavy-duty diesel engine.

PubMed

Feng, Xiangyu; Ge, Yunshan; Ma, Chaochen; Tan, Jianwei

2015-01-01

To evaluate the effects of particulate oxidation catalyst (POC) on unregulated pollutant emission and toxicity characteristics, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), soot, soluble organic fractions (SOF) and sulphate emissions emitted from a heavy-duty diesel engine retrofitted with a POC were investigated on a diesel bench. The particulate matter (PM) in the exhaust was collected by Teflon membrane, and the PAHs and VOCs were analysed by a gas chromatography/mass spectrometer (GC/MS). The results indicate that the POC exhibits good performance on the emission control of VOCs, PAHs and PM. The POC and the diesel particulate filters (DPF) both show a good performance on reducing the VOCs emission. Though the brake-specific emission (BSE) reductions of the total PAHs by the POC were lower than those by the DPF, the POC still removed almost more than 50% of the total PAHs emission. After the engine was retrofitted with the POC, the reductions of the PM mass, SOF and soot emissions were 45.2-89.0%, 7.8-97.7% and 41.7-93.3%, respectively. The sulphate emissions decreased at low and medium loads, whereas at high load, the results were contrary. The PAHs emissions were decreased by 32.4-69.1%, and the contributions of the PAH compounds were affected by the POC, as well as by load level. The benzo[a]pyrene equivalent (BaPeq) of PAHs emissions were reduced by 35.9-97.6% with the POC. The VOCs emissions were reduced by 21.8-94.1% with the POC, and the reduction was more evident under high load.

Effect of measurement protocol on organic aerosol measurements of exhaust emissions from gasoline and diesel vehicles

NASA Astrophysics Data System (ADS)

Kim, Youngseob; Sartelet, Karine; Seigneur, Christian; Charron, Aurélie; Besombes, Jean-Luc; Jaffrezo, Jean-Luc; Marchand, Nicolas; Polo, Lucie

2016-09-01

Exhaust emissions of semi-volatile organic compounds (SVOC) from passenger vehicles are usually estimated only for the particle phase via the total particulate matter measurements. However, they also need to be estimated for the gas phase, as they are semi-volatile. To better estimate SVOC emission factors of passenger vehicles, a measurement campaign using a chassis dynamometer was conducted with different instruments: (1) a constant volume sampling (CVS) system in which emissions were diluted with filtered air and sampling was performed on filters and polyurethane foams (PUF) and (2) a Dekati Fine Particle Sampler (FPS) in which emissions were diluted with purified air and sampled with on-line instruments (PTR-ToF-MS, HR-ToF-AMS, MAAP, CPC). Significant differences in the concentrations of organic carbon (OC) measured by the instruments are observed. The differences can be explained by sampling artefacts, differences between (1) the time elapsed during sampling (in the case of filter and PUF sampling) and (2) the time elapsed from emission to measurement (in the case of on-line instruments), which vary from a few seconds to 15 min, and by the different dilution factors. To relate elapsed times and measured concentrations of OC, the condensation of SVOC between the gas and particle phases is simulated with a dynamic aerosol model. The simulation results allow us to understand the relation between elapsed times and concentrations in the gas and particle phases. They indicate that the characteristic times to reach thermodynamic equilibrium between gas and particle phases may be as long as 8 min. Therefore, if the elapsed time is less than this characteristic time to reach equilibrium, gas-phase SVOC are not at equilibrium with the particle phase and a larger fraction of emitted SVOC will be in the gas phase than estimated by equilibrium theory, leading to an underestimation of emitted OC if only the particle phase is considered or if the gas-phase SVOC are estimated by equilibrium theory. Current European emission inventories for passenger cars do not yet estimate gas-phase SVOC emissions, although they may represent 60% of total emitted SVOC (gas + particle phases).

Chip-scale fluorescence microscope based on a silo-filter complementary metal-oxide semiconductor image sensor.

PubMed

Ah Lee, Seung; Ou, Xiaoze; Lee, J Eugene; Yang, Changhuei

2013-06-01

We demonstrate a silo-filter (SF) complementary metal-oxide semiconductor (CMOS) image sensor for a chip-scale fluorescence microscope. The extruded pixel design with metal walls between neighboring pixels guides fluorescence emission through the thick absorptive filter to the photodiode of a pixel. Our prototype device achieves 13 μm resolution over a wide field of view (4.8 mm × 4.4 mm). We demonstrate bright-field and fluorescence longitudinal imaging of living cells in a compact, low-cost configuration.

Tuning of the emission color of organic light emitting diodes via smartly designed aluminum plasmonics

NASA Astrophysics Data System (ADS)

Auer-Berger, Manuel; Tretnak, Veronika; Wenzl, Franz-Peter; Krenn, Joachim; List-Kratochvil, Emil J. W.

2017-02-01

With the invention of phosphorescent emitter material, organic light emitting diodes with internal quantum yields of up to 100% can be realized. Still, the extraction of the light from the OLED stack is a bottleneck, which hampers the availability of OLEDs with large external quantum efficiencies. In this contribution, we highlight the advantages of integrating aluminum nanodisc arrays into the OLED stack. By this, not only the out-coupling of light can be enhanced, but also the emission color can be tailored and controlled. By means of extinction- and fluorescence spectroscopy measurements we are able to show how the sharp features observed in the extinction measurements correlate with a very selective fluorescence enhancement of the organic emitter materials used in these studies. At the same time, localized surface plasmon resonances of the individual nanodiscs further modify the emission spectrum, e.g., by filtering the green emission tail. A combination of these factors leads to a modification of the emission color in between CIE1931 (x,y) chromaticity coordinates of (0.149, 0.225) and (0.152, 0.352). After accounting for the sensitivity of the human eye, we are able to demonstrate that this adjustment of the chromaticity coordinates goes is accompanied by an increase in device efficiency.

Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions.

PubMed

Gentner, Drew R; Jathar, Shantanu H; Gordon, Timothy D; Bahreini, Roya; Day, Douglas A; El Haddad, Imad; Hayes, Patrick L; Pieber, Simone M; Platt, Stephen M; de Gouw, Joost; Goldstein, Allen H; Harley, Robert A; Jimenez, Jose L; Prévôt, André S H; Robinson, Allen L

2017-02-07

Secondary organic aerosol (SOA) is formed from the atmospheric oxidation of gas-phase organic compounds leading to the formation of particle mass. Gasoline- and diesel-powered motor vehicles, both on/off-road, are important sources of SOA precursors. They emit complex mixtures of gas-phase organic compounds that vary in volatility and molecular structure-factors that influence their contributions to urban SOA. However, the relative importance of each vehicle type with respect to SOA formation remains unclear due to conflicting evidence from recent laboratory, field, and modeling studies. Both are likely important, with evolving contributions that vary with location and over short time scales. This review summarizes evidence, research needs, and discrepancies between top-down and bottom-up approaches used to estimate SOA from motor vehicles, focusing on inconsistencies between molecular-level understanding and regional observations. The effect of emission controls (e.g., exhaust aftertreatment technologies, fuel formulation) on SOA precursor emissions needs comprehensive evaluation, especially with international perspective given heterogeneity in regulations and technology penetration. Novel studies are needed to identify and quantify "missing" emissions that appear to contribute substantially to SOA production, especially in gasoline vehicles with the most advanced aftertreatment. Initial evidence suggests catalyzed diesel particulate filters greatly reduce emissions of SOA precursors along with primary aerosol.

Refining the Workflow of UV Camera Measurements: Data Collection from Low Emission Rate Volcanoes under Variable Conditions

NASA Astrophysics Data System (ADS)

Brewer, I. D.; Werner, C. A.; Nadeau, P. A.

2010-12-01

UV camera systems are gaining popularity worldwide for quantifying SO2 column abundances and emission rates from volcanoes, which serve as primary measures of volcanic hazard and aid in eruption forecasting. To date many of the investigations have focused on fairly active and routinely monitored volcanoes under optimal conditions. Some recent studies have begun to recommend protocols and procedures for data collection, but additional questions still need to be addressed. In this study we attempt to answer these questions, and also present results from volcanoes that are rarely monitored. Conditions at these volcanoes are typically sub-optimal for UV camera measurements. Discussion of such data is essential in the assessment of the wider applicability of UV camera measurements for SO2 monitoring purposes. Data discussed herein consists of plume images from volcanoes with relatively low emission rates, with varying weather conditions and from various distances (2-12 km). These include Karangatang Volcano (Indonesia), Mount St. Helens (Washington, USA), and Augustine and Redoubt Volcanoes (Alaska, USA). High emission rate data were also collected at Kilauea Volcano (Hawaii, USA), and blue sky test images with no plume were collected at Mammoth Mountain (California, USA). All data were collected between 2008 and 2010 using both single-filter (307 nm) and dual-filter (307 nm/326 nm) systems and were accompanied by FLYSPEC measurements. With the dual-filter systems, both a filter wheel setup and a synchronous-imaging dual-camera setup were employed. Data collection and processing questions included (1) what is the detection limit of the camera, (2) how large is the variability in raw camera output, (3) how do camera optics affect the measurements and how can this be corrected, (4) how much variability is observed in calibration under various conditions, (5) what is the optimal workflow for image collection and processing, and (6) what is the range of camera operating conditions? Besides emission rates from these infrequently monitored volcanoes, the results of this study include a recommended workflow and procedure for image collection and calibration, and a MATLAB-based algorithm for batch processing, thereby enabling accurate emission rates at 1 Hz when a synchronous-imaging dual-camera setup is used.

Reduction in (pro-)inflammatory responses of lung cells exposed in vitro to diesel exhaust treated with a non-catalyzed diesel particle filter

NASA Astrophysics Data System (ADS)

Steiner, Sandro; Czerwinski, Jan; Comte, Pierre; Müller, Loretta L.; Heeb, Norbert V.; Mayer, Andreas; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2013-12-01

Increasingly stringent regulation of particulate matter emissions from diesel vehicles has led to the widespread use of diesel particle filters (DPFs), the effect of which on exhaust toxicity is so far poorly understood. We exposed a cellular model of the human respiratory epithelium at the air-liquid interface to non-catalyzed wall-flow DPF-filtered diesel exhaust and compared the resulting biological responses to the ones observed upon exposure to unfiltered exhaust. Filtered diesel exhaust acted highly oxidative, even though to a lesser extent than unfiltered exhaust (quantification of total reduced glutathione), and both exhaust types triggered comparable responses to oxidative stress (measurement of heme-oxygenase 1 (HMOX1) and superoxide-dismutase (SOD1) gene expression). Further, diesel exhaust filtration significantly reduced pro-inflammatory responses (measurement of tumor necrosis factor (TNF) and interleukin-8 (IL-8) gene expression and quantification of the secretion of their gene products TNF-α and IL-8). Because inflammatory processes are central to the onset of adverse respiratory health effects caused by diesel exhaust inhalation, our results imply that DPFs may make a valuable contribution to the detoxification of diesel vehicle emissions. The induction of significant oxidative stress by filtered diesel exhaust however, also implies that the non-particulate exhaust components also need to be considered for lung cell risk assessment.

Stability and performance of notch filter control for unbalance response

NASA Technical Reports Server (NTRS)

Knospe, C. R.

1992-01-01

Many current applications of magnetic bearings for rotating machinery employ notch filters in the feedback control loop to reduce the synchronous forces transmitted through the bearings. The capabilities and limitations of notch filter control are investigated. First, a rigid rotor is examined with some classical root locus techniques. Notch filter control is shown to result in conditional stability whenever complete synchronous attenuation is required. Next, a nondimensional parametric symmetric flexible three mass rotor model is constructed. An examination of this model for several test cases illustrates the limited attenuation possible with notch filters at and near the system critical speeds when the bearing damping is low. The notch filter's alteration of the feedback loop is shown to cause stability problems which limits performance. Poor transient response may also result. A high speed compressor is then examined as a candidate for notch filter control. A collocated 22 mass station model with lead-lag control is used. The analysis confirms the reduction in stability robustness that can occur with notch filter control. It is concluded that other methods of synchronous vibration control yield greater performance without compromising stability.

Combination of biodiesel-ethanol-diesel fuel blend and SCR catalyst assembly to reduce emissions from a heavy-duty diesel engine.

PubMed

Shi, Xiaoyan; Yu, Yunbo; He, Hong; Shuai, Shijin; Dong, Hongyi; Li, Rulong

2008-01-01

In this study, the efforts to reduce NOx and particulate matter (PM) emissions from a diesel engine using both ethanol-selective catalytic reduction (SCR) of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-diesel fuel blend (BE-diesel) on an engine bench test are discussed. Compared with diesel fuel, use of BE-diesel increased PM emissions by 14% due to the increase in the soluble organic fraction (SOF) of PM, but it greatly reduced the Bosch smoke number by 60%-80% according to the results from 13-mode test of European Stationary Cycle (ESC) test. The SCR catalyst was effective in NOx reduction by ethanol, and the NOx conversion was approximately 73%. Total hydrocarbons (THC) and CO emissions increased significantly during the SCR of NOx process. Two diesel oxidation catalyst (DOC) assemblies were used after Ag/Al2O3 converter to remove CO and HC. Different oxidation catalyst showed opposite effect on PM emission. The PM composition analysis revealed that the net effect of oxidation catalyst on total PM was an integrative effect on SOF reduction and sulfate formation of PM. The engine bench test results indicated that the combination of BE-diesel and a SCR catalyst assembly could provide benefits for NOx and PM emissions control even without using diesel particle filters (DPFs).

40 CFR 60.2165 - What monitoring equipment must I install and what parameters must I monitor?

Code of Federal Regulations, 2013 CFR

2013-07-01

... installed in each baghouse compartment or cell. For negative pressure or induced air fabric filters, the bag... test. (g) For waste-burning kilns not equipped with a wet scrubber, in place of hydrogen chloride..., maintain, and operate a continuous emission monitoring system for monitoring hydrogen chloride emissions...

Emissions calculated from particulate matter and gaseous ammonia measurements from a commercial dairy in California, USA

USDA-ARS?s Scientific Manuscript database

Emission rates and factors for particulate matter (PM) and gaseous ammonia (NH3) were estimated from measurements taken at a dairy in California, USA in June 2008. Concentration measurements were made using both point and remote sensors. Filter-based PM samplers and OPCs characterized aerodynamic an...

75 FR 24945 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

... Emission Standards for Hazardous Air Pollutants (NESHAP) for Mineral Wool Production (40 CFR part 63... wool production plants are required to install fabric filter bag leak detection systems and then... Air Act. The required information consists of emissions data and other information that have been...

Bayesian modelling of the emission spectrum of the Joint European Torus Lithium Beam Emission Spectroscopy system.

PubMed

Kwak, Sehyun; Svensson, J; Brix, M; Ghim, Y-C

2016-02-01

A Bayesian model of the emission spectrum of the JET lithium beam has been developed to infer the intensity of the Li I (2p-2s) line radiation and associated uncertainties. The detected spectrum for each channel of the lithium beam emission spectroscopy system is here modelled by a single Li line modified by an instrumental function, Bremsstrahlung background, instrumental offset, and interference filter curve. Both the instrumental function and the interference filter curve are modelled with non-parametric Gaussian processes. All free parameters of the model, the intensities of the Li line, Bremsstrahlung background, and instrumental offset, are inferred using Bayesian probability theory with a Gaussian likelihood for photon statistics and electronic background noise. The prior distributions of the free parameters are chosen as Gaussians. Given these assumptions, the intensity of the Li line and corresponding uncertainties are analytically available using a Bayesian linear inversion technique. The proposed approach makes it possible to extract the intensity of Li line without doing a separate background subtraction through modulation of the Li beam.

Physico-Chemical Characterization of Fine and Ultrafine Particles Emitted during Diesel Particulate Filter Active Regeneration of Euro5 Diesel Vehicles.

PubMed

R'Mili, Badr; Boréave, Antoinette; Meme, Aurelie; Vernoux, Philippe; Leblanc, Mickael; Noël, Ludovic; Raux, Stephane; D'Anna, Barbara

2018-03-06

Diesel particulate filters (DPFs) are commonly employed in modern passenger cars to comply with current particulate matter (PM) emission standards. DPFs requires periodic regeneration to remove the accumulated matter. During the process, high-concentration particles, in both nucleation and accumulation modes, are emitted. Here, we report new information on particle morphology and chemical composition of fine (FPs) and ultrafine particles (UFPs) measured downstream of the DPF during active regeneration of two Euro 5 passenger cars. The first vehicle was equipped with a close-coupled diesel oxidation catalyst (DOC) and noncatalyzed DPF combined with fuel borne catalyst and the second one with DOC and a catalyzed-diesel particle filter (CDPF). Differences in PM emission profiles of the two vehicles were related to different after treatment design, regeneration strategies, and vehicle characteristics and mileage. Particles in the nucleation mode consisted of ammonium bisulfate, sulfate and sulfuric acid, suggesting that the catalyst desulfation is the key process in the formation of UFPs. Larger particles and agglomerates, ranging from 90 to 600 nm, consisted of carbonaceous material (soot and soot aggregates) coated by condensable material including organics, ammonium bisulfate and sulfuric acid. Particle emission in the accumulation mode was due to the reduced filtration efficiency (soot cake oxidation) throughout the regeneration process.

Matched-filtering line search methods applied to Suzaku data

NASA Astrophysics Data System (ADS)

Miyazaki, Naoto; Yamada, Shin'ya; Enoto, Teruaki; Axelsson, Magnus; Ohashi, Takaya

2016-12-01

A detailed search for emission and absorption lines and an assessment of their upper limits are performed for Suzaku data. The method utilizes a matched-filtering approach to maximize the signal-to-noise ratio for a given energy resolution, which could be applicable to many types of line search. We first applied it to well-known active galactic nuclei spectra that have been reported to have ultra-fast outflows, and find that our results are consistent with previous findings at the ˜3σ level. We proceeded to search for emission and absorption features in two bright magnetars 4U 0142+61 and 1RXS J1708-4009, applying the filtering method to Suzaku data. We found that neither source showed any significant indication of line features, even using long-term Suzaku observations or dividing their spectra into spin phases. The upper limits on the equivalent width of emission/absorption lines are constrained to be a few eV at ˜1 keV and a few hundreds of eV at ˜10 keV. This strengthens previous reports that persistently bright magnetars do not show proton cyclotron absorption features in soft X-rays and, even if they exist, they would be broadened or much weaker than below the detection limit of X-ray CCD.

Biophotonic markers of malignancy: Discriminating cancers using wavelength-specific biophotons.

PubMed

Murugan, Nirosha J; Rouleau, Nicolas; Karbowski, Lukasz M; Persinger, Michael A

2018-03-01

Early detection is a critically important factor when successfully diagnosing and treating cancer. Whereas contemporary molecular techniques are capable of identifying biomarkers associated with cancer, surgical interventions are required to biopsy tissue. The common imaging alternative, positron-emission tomography (PET), involves the use of nuclear material which poses some risks. Novel, non-invasive techniques to assess the degree to which tissues express malignant properties are now needed. Recent developments in biophoton research have made it possible to discriminate cancerous cells from normal cells both in vitro and in vivo. The current study expands upon a growing body of literature where we classified and characterized malignant and non-malignant cell types according to their biophotonic activity. Using wavelength-exclusion filters, we demonstrate that ratios between infrared and ultraviolet photon emissions differentiate cancer and non-cancer cell types. Further, we identified photon sources associated with three filters (420-nm, 620-nm., and 950-nm) which classified cancer and non-cancer cell types. The temporal increases in biophoton emission within these wavelength bandwidths is shown to be coupled with intrisitic biomolecular events using Cosic's resonant recognition model. Together, the findings suggest that the use of wavelength-exclusion filters in biophotonic measurement can be employed to detect cancer in vitro.

Technology could deliver 90% Hg reduction from coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maize, K.

2009-07-15

Reducing mercury emissions at coal-fired power plants by 90% has been considered the holy grail of mercury control. A new technology promises to get used there, but at a price. This is a mixture of chemical approaches, including activated carbon injection into the gases coming off the combustor along with injection of trona or calcium carbonate to reduce sulfur trioxide in the exhaust gases. The trick according to Babcock and Wilcox's manager Sam Kumar, to 'capture the mercury as a particulate on the carbon and then capture the particulate' in an electrostatic precipitator or a fabric filter baghouse. 2 figs.

Resolution improvement in positron emission tomography using anatomical Magnetic Resonance Imaging.

PubMed

Chu, Yong; Su, Min-Ying; Mandelkern, Mark; Nalcioglu, Orhan

2006-08-01

An ideal imaging system should provide information with high-sensitivity, high spatial, and temporal resolution. Unfortunately, it is not possible to satisfy all of these desired features in a single modality. In this paper, we discuss methods to improve the spatial resolution in positron emission imaging (PET) using a priori information from Magnetic Resonance Imaging (MRI). Our approach uses an image restoration algorithm based on the maximization of mutual information (MMI), which has found significant success for optimizing multimodal image registration. The MMI criterion is used to estimate the parameters in the Sharpness-Constrained Wiener filter. The generated filter is then applied to restore PET images of a realistic digital brain phantom. The resulting restored images show improved resolution and better signal-to-noise ratio compared to the interpolated PET images. We conclude that a Sharpness-Constrained Wiener filter having parameters optimized from a MMI criterion may be useful for restoring spatial resolution in PET based on a priori information from correlated MRI.

Planetary nebulae with UVIT: Far ultra-violet halo around the Bow Tie nebula (NGC 40)

NASA Astrophysics Data System (ADS)

Kameswara Rao, N.; Sutaria, F.; Murthy, J.; Krishna, S.; Mohan, R.; Ray, A.

2018-01-01

Context. NGC 40 is a planetary nebula with diffuse X-ray emission, suggesting an interaction of the high-speed wind from WC8 central star (CS) with the nebula. It shows strong C IV 1550 Å emission that cannot be explained by thermal processes alone. We present here the first map of this nebula in C IV emission using broad band filters on the Ultra-Violet Imaging Telescope (UVIT). Aim. We aim to map the hot C IV-emitting gas and its correspondence with soft X-ray (0.3-8 keV) emitting regions in order to study the shock interaction between the nebula and the ISM. We also aim to illustrate the potential of UVIT for nebular studies. Methods: We carry out a morphological study of images of the nebula obtained at an angular resolution of about 1.3″ in four UVIT filter bands that include C IV 1550 Å and [C II] 2326 Å lines as well as UV continuum. We also make comparisons with X-ray, optical, and IR images from the literature. Results: The [C II] 2326 Å images show the core of the nebula with two lobes on either side of CS similar to [N II]. The C IV emission in the core shows similar morphology and extent to that of diffuse X-ray emission concentrated in nebular condensations. A surprising UVIT discovery is the presence of a large faint far UV (FUV) halo in an FUV filter with λeff of 1608 Å. The UV halo is not present in any other UV filter. The FUV halo is most likely due to UV fluorescence emission from the Lyman bands of H2 molecules. Unlike the optical and IR halo, the FUV halo trails predominantly towards the south-east side of the nebular core, opposite to the CS's proper motion direction. Conclusions: Morphological similarity of C IV 1550 Å and X-ray emission in the core suggests that it results mostly from the interaction of strong CS wind with the nebula. The FUV halo in NGC 40 highlights the extensive existence of H2 molecules in the regions even beyond the optical and IR halos. Thus UV studies are important to estimate the amount of H2, which is probably the most dominant molecule and significant for mass-loss studies. Based on data obtained with the Ultra-Violet Imaging Telescope (UVIT) on the ASTROSAT satellite.

An electron impact emission spectroscopy flux sensor for monitoring deposition rate at high background gas pressure with improved accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, C.; Blissett, C. D.; Diehl, G.

2008-07-15

Electron impact emission spectroscopy (EIES) has been proven to be a critical tool for film composition control during codeposition processes for the fabrication of multicomponent thin film materials including the high-efficiency copper-indium-gallium-diselenide photovoltaic cells. This technique is highly specific to atomic species because the emission spectrum of each element is unique, and the typical width of atomic emission lines is very narrow. Noninterfering emission lines can generally be allocated to different atomic species. However, the electron impact emission spectra of many molecular species are often broadband in nature. When the optical emission from an EIES sensor is measured by usingmore » a wavelength selection device with a modest resolution, such as an optical filter or monochromator, the emissions from common residual gases may interfere with that from the vapor flux and cause erroneous flux measurement. The interference is most pronounced when measuring low flux density with the presence of gases such as in reactive deposition processes. This problem is solved by using a novel EIES sensor that has two electron impact excitation sources in separate compartments but with one common port for optical output. The vapor flux is allowed to pass through one compartment only. Using a tristate excitation scheme and appropriate signal processing technique, the interfering signals from residual gases can be completely eliminated from the output signal of the EIES monitor for process control. Data obtained from Cu and Ga evaporations with the presence of common residual gases such as CO{sub 2} and H{sub 2}O are shown to demonstrate the improvement in sensor performance. The new EIES sensor is capable of eliminating the effect of interfering residual gases with pressure as high as in the upper 10{sup -5} Torr range.« less

Mapping Boron Dioxide (BO2) Light Emission During Ballistic Initiation of Boron

DTIC Science & Technology

2016-03-03

Dreizin; unreferenced). Essentially, 2 light sensors (cameras), each filtered over a narrow wavelength region, observe an event over the same line of...background incandescence (subtraction gave a qualitatively similar result). For imaging BO2 emission, the light sensors were 2 Phantom V7.3 monochrome...A check of the temperature measurement technique using emission from an acetylene/air diffusion flame gave reasonable results (1,800 K outer soot

Electrically heated particulate filter propagation support methods and systems

DOEpatents

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

2011-06-07

A control system that controls regeneration of a particulate filter is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate combustion of particulate matter in the particulate filter. A propagation module estimates a propagation status of the combustion of the particulate matter based on a combustion temperature. A temperature adjustment module controls the combustion temperature by selectively increasing a temperature of exhaust that passes through the particulate filter.

Optically trapped atomic resonant devices for narrow linewidth spectral imaging

NASA Astrophysics Data System (ADS)

Qian, Lipeng

This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the absorption and fluorescence. The optimum resolution of the fluorescent image is predicted by simulation. Radiation trapping is also shown to be useful for the generation of ultra-narrow linewidth light from an atomic vapor flash lamp. A 2 nanosecond, high voltage pulse is used to excite low pressure mercury vapor mixed with noble gases, producing high intensity emission at the mercury resonant line at 253.7 nm. With a nanosecond pumping time and high electrical current, the radiation intensity of the mercury discharge is increased significantly compared to a normal glow discharge lamp, while simultaneously suppressing the formation of an arc discharge. By avoiding the arc discharge, discrete spectral lines of mercury were kept at narrow bandwidth. Due to radiation trapping, the emission linewidth from the nanosecond mercury lamp decreases with time and produces ultra-narrow linewidth emission 100 ns after of the excitation, this linewidth is verified by absorption measurements through low pressure mercury absorption filter. The lamp is used along with mercury absorption filters for spectroscopic applications, including Filtered Rayleigh Scattering with different CO2 pressures and Raman scattering from methanol.

Particulate matter emissions, and metals and toxic elements in airborne particulates emitted from biomass combustion: The importance of biomass type and combustion conditions.

PubMed

Zosima, Angela T; Tsakanika, Lamprini-Areti V; Ochsenkühn-Petropoulou, Maria Th

2017-05-12

The aim of this study was to investigate the impact of biomass combustion with respect to burning conditions and fuel types on particulate matter emissions (PM 10 ) and their metals as well as toxic elements content. For this purpose, different lab scale burning conditions were tested (20 and 13% O 2 in the exhaust gas which simulate an incomplete and complete combustion respectively). Furthermore, two pellet stoves (8.5 and 10 kW) and one open fireplace were also tested. In all cases, 8 fuel types of biomass produced in Greece were used. Average PM 10 emissions ranged at laboratory-scale combustions from about 65 to 170 mg/m 3 with flow oxygen at 13% in the exhaust gas and from 85 to 220 mg/m 3 at 20% O 2 . At pellet stoves the emissions were found lower (35 -85 mg/m 3 ) than the open fireplace (105-195 mg/m 3 ). The maximum permitted particle emission limit is 150 mg/m 3 . Metals on the PM 10 filters were determined by several spectrometric techniques after appropriate digestion or acid leaching of the filters, and the results obtained by these two methods were compared. The concentration of PM 10 as well as the total concentration of the metals on the filters after the digestion procedure appeared higher at laboratory-scale combustions with flow oxygen at 20% in the exhaust gas and even higher at fireplace in comparison to laboratory-scale combustions with 13% O 2 and pellet stoves. Modern combustion appliances and appropriate types of biomass emit lower PM 10 emissions and lower concentration of metals than the traditional devices where incomplete combustion conditions are observed. Finally, a comparison with other studies was conducted resulting in similar results.

Effects of a combined Diesel particle filter-DeNOx system (DPN) on reactive nitrogen compounds emissions: a parameter study.

PubMed

Heeb, Norbert V; Haag, Regula; Seiler, Cornelia; Schmid, Peter; Zennegg, Markus; Wichser, Adrian; Ulrich, Andrea; Honegger, Peter; Zeyer, Kerstin; Emmenegger, Lukas; Zimmerli, Yan; Czerwinski, Jan; Kasper, Markus; Mayer, Andreas

2012-12-18

The impact of a combined diesel particle filter-deNO(x) system (DPN) on emissions of reactive nitrogen compounds (RNCs) was studied varying the urea feed factor (α), temperature, and residence time, which are key parameters of the deNO(x) process. The DPN consisted of a platinum-coated cordierite filter and a vanadia-based deNO(x) catalyst supporting selective catalytic reduction (SCR) chemistry. Ammonia (NH₃) is produced in situ from thermolysis of urea and hydrolysis of isocyanic acid (HNCO). HNCO and NH₃ are both toxic and highly reactive intermediates. The deNO(x) system was only part-time active in the ISO8178/4 C1cycle. Urea injection was stopped and restarted twice. Mean NO and NO₂ conversion efficiencies were 80%, 95%, 97% and 43%, 87%, 99%, respectively, for α = 0.8, 1.0, and 1.2. HNCO emissions increased from 0.028 g/h engine-out to 0.18, 0.25, and 0.26 g/h at α = 0.8, 1.0, and 1.2, whereas NH₃ emissions increased from <0.045 to 0.12, 1.82, and 12.8 g/h with maxima at highest temperatures and shortest residence times. Most HNCO is released at intermediate residence times (0.2-0.3 s) and temperatures (300-400 °C). Total RNC efficiencies are highest at α = 1.0, when comparable amounts of reduced and oxidized compounds are released. The DPN represents the most advanced system studied so far under the VERT protocol achieving high conversion efficiencies for particles, NO, NO₂, CO, and hydrocarbons. However, we observed a trade-off between deNO(x) efficiency and secondary emissions. Therefore, it is important to adopt such DPN technology to specific application conditions to take advantage of reduced NO(x) and particle emissions while avoiding NH₃ and HNCO slip.

Advancements to the planogram frequency–distance rebinning algorithm

PubMed Central

Champley, Kyle M; Raylman, Raymond R; Kinahan, Paul E

2010-01-01

In this paper we consider the task of image reconstruction in positron emission tomography (PET) with the planogram frequency–distance rebinning (PFDR) algorithm. The PFDR algorithm is a rebinning algorithm for PET systems with panel detectors. The algorithm is derived in the planogram coordinate system which is a native data format for PET systems with panel detectors. A rebinning algorithm averages over the redundant four-dimensional set of PET data to produce a three-dimensional set of data. Images can be reconstructed from this rebinned three-dimensional set of data. This process enables one to reconstruct PET images more quickly than reconstructing directly from the four-dimensional PET data. The PFDR algorithm is an approximate rebinning algorithm. We show that implementing the PFDR algorithm followed by the (ramp) filtered backprojection (FBP) algorithm in linogram coordinates from multiple views reconstructs a filtered version of our image. We develop an explicit formula for this filter which can be used to achieve exact reconstruction by means of a modified FBP algorithm applied to the stack of rebinned linograms and can also be used to quantify the errors introduced by the PFDR algorithm. This filter is similar to the filter in the planogram filtered backprojection algorithm derived by Brasse et al. The planogram filtered backprojection and exact reconstruction with the PFDR algorithm require complete projections which can be completed with a reprojection algorithm. The PFDR algorithm is similar to the rebinning algorithm developed by Kao et al. By expressing the PFDR algorithm in detector coordinates, we provide a comparative analysis between the two algorithms. Numerical experiments using both simulated data and measured data from a positron emission mammography/tomography (PEM/PET) system are performed. Images are reconstructed by PFDR+FBP (PFDR followed by 2D FBP reconstruction), PFDRX (PFDR followed by the modified FBP algorithm for exact reconstruction) and planogram filtered backprojection image reconstruction algorithms. We show that the PFDRX algorithm produces images that are nearly as accurate as images reconstructed with the planogram filtered backprojection algorithm and more accurate than images reconstructed with the PFDR+FBP algorithm. Both the PFDR+FBP and PFDRX algorithms provide a dramatic improvement in computation time over the planogram filtered backprojection algorithm. PMID:20436790

Comparison Between Elemental Carbon Measured Using Thermal-Optical Analysis and Black Carbon Measurements Using A Novel Cellphone-Based System

NASA Astrophysics Data System (ADS)

Ramanathan, N.; Khan, B.; Leong, I.; Lukac, M.

2011-12-01

Black carbon (BC) is produced through the incomplete combustion of fossil and solid fuels. Current BC emissions inventories have large uncertainties of factors of 2 or more due to sparse measurements and because BC is often emitted by local sources that vary over time and space (Bond et al, 2004). Those uncertainties are major sources of error in air pollution models. Emissions from a variety of improved cookstove/fuel/combustion conditions were collected on pre-conditioned 47 mm quartz-fiber filters and analyzed for organic carbon (OC) and elemental carbon (EC) using thermal-optical analysis (TOA). The samples were then analyzed for BC concentration by using cellphone-based instrumentation developed by Ramanathan et al., 2011. The cellphone-based monitoring system (CBMS) is a wireless, low-cost, low-power system that monitors BC emissions. The CBMS is comprised of an aerosol filter sampler containing a battery-powered air pump and a 25mm filter holder that draws air in through a quartz-fiber filter. As black carbon deposits increase, the filter darkens--the darkest color representing the highest loading. A cellphone photograph of the filter with the black carbon deposit is taken and relayed to an analytics unit for comparison to a reference scale to estimate airborne BC concentration. The BC concentration can then be compared to the thermally derived EC concentration. TOA was conducted on a Sunset Laboratory Dual Optics Carbon Analyzer using a modified version of the Birch and Cary (1996) NIOSH 5040 protocol. The dual-optical instrument permitted simultaneous monitoring of the transmission (TOT) and reflectance (TOR). 619 samples were collected; EC was obtained using NIOSH TOT and NIOSH TOR methods, and BC was obtained using the CBMS analytics unit. The mean BC value reported by the CBMS agrees within 20% of the reference values for EC, confirming the findings in Ramanathan et al. (2011) based on samples from India. Given this accuracy, we conclude that the CBMS provides an affordable real-time method for gathering BC data on a mass scale. The CBMS' scalability should enable dense deployments near emissions sources and reduce uncertainty in emissions inventories due to undersampling. Bond, T. C., E. Bhardwaj, R. Dong, R. Jogani, S. Jung, C. Roden, D. G. Streets, and N. M. Trautmann (2007), Historical emissions of black and organic carbon aerosol from energy-related combustion, 1850-2000, Global Biogeochem. Cycles, 21, GB2018, doi:10.1029/2006GB002840. Birch, M. E. and R.A. Cary (1996), Elemental Carbon-Based Method for Monitoring Occupational Exposures to Particulate Diesel Exhaust. Aerosol Sci. Technol., 25, 221-241. NIOSH (1996). Elemental carbon (diesel particulate) method 5040. NIOSH Manual of Analytical Methods, 4th ed. National Institute for Occupational Safety and Health, Cincinnati, Ohio (1st Suppl.). Ramanathan, N., M. Lukac, T. Ahmed, A. Kar, P.S. Praveen, T. Honles, I. Leong, I.H. Rehman, J.J. Schauer, V. Ramanathan (2011), A cellphone based system for large-scale monitoring of black carbon, Atmos. Environ., 45 (26), 4481-4487.

40 CFR Table 2 to Subpart Rrr of... - Summary of Operating Requirements for New and Existing Affected Sources and Emission Units

Code of Federal Regulations, 2011 CFR

2011-07-01

... with fabric filter Bag leak detector or Initiate corrective action within 1-hr of alarm and complete in... operation Operate in accordance with OM&M plan. b Bag leak detector or Initiate corrective action within 1... accordance with OM&M plan. b Dross-only furnace with fabric filter Bag leak detector or Initiate corrective...

Biological effects of emissions from resistance spot welding of zinc-coated material after controlled exposure of healthy human subjects.

PubMed

Gube, Monika; Kraus, Thomas; Lenz, Klaus; Reisgen, Uwe; Brand, Peter

2014-06-01

Do emissions from a resistance spot welding process of zinc-coated materials induce systemic inflammation in healthy subjects after exposure for 6 hours? Twelve healthy male subjects were exposed once for 6 hours either to filtered ambient air or to welding fume from resistance spot welding of zinc-coated material (mass concentration approximately 100 μg m). Biological effects were measured before, after, and 24 hours after exposure. At the concentrations used in this study, however, the suspected properties of ultrafine particles did not lead to systemic inflammation as reflected by high-sensitivity C-reactive protein or other endpoint parameters under consideration. Ultrafine particles from a resistance spot welding process of zinc-covered materials with a number concentration of about 10 cm and a mass concentration of about 100 μg m did not induce systemic inflammation.

High efficiency radioisotope thermophotovoltaic prototype generator

NASA Technical Reports Server (NTRS)

Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

1995-01-01

A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With 250 Watts of heat input, we expect this prototype to produce over 300 Watts of electrical energy output for a system energy conversion efficiency of over 12%. This low risk, near term design provides advances relative to present radioisotope thermophotovoltaic generators and has the additional advantage of allowing component and system development and testing to begin immediately. Improved cells and filters can easily be incorporated in this baseline system if they should become available in the future.

High efficiency radioisotope thermophotovoltaic prototype generator

NASA Astrophysics Data System (ADS)

Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

1995-10-01

A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With 250 Watts of heat input, we expect this prototype to produce over 300 Watts of electrical energy output for a system energy conversion efficiency of over 12%. This low risk, near term design provides advances relative to present radioisotope thermophotovoltaic generators and has the additional advantage of allowing component and system development and testing to begin immediately. Improved cells and filters can easily be incorporated in this baseline system if they should become available in the future.

Design and operation of a medium speed 12-cylinder coal-fueled diesel engine. Phase 2: Improvements

NASA Astrophysics Data System (ADS)

Confer, G. L.; Hsu, B. D.; McDowell, R. E.; Gal, E.; Vankleunen, W.; Kaldor, S.; Mengel, M.

Under the sponsorship of the US Department of Energy, General Electric has been pioneering the development of a coal fired diesel engine to power a locomotive. The feasibility of using a coal water slurry (CWS) mixture as a fuel in a medium speed diesel engine has been demonstrated with the first successful locomotive systems test in 1991 on the GE Transportation Systems test track in Erie, PA. Phase 2 of the development process incorporates the results of the programs research in durable engine parts, improved combustion efficiency, and emissions reduction. A GE 7FDL12 engine has been built using diamond insert injector nozzles, tungsten carbide coated piston rings, and tungsten carbide coated liners to overcome power assembly wear. Electronic controlled fuel injection for both diesel pilot and main CWS injector were incorporated to control injection timing. An envelop filter and copper oxide sorbent system were used to cleanup engine emissions. The system is capable of removing over 99% of the particulates, 90% of the SO2, and 85% of NO(x).

Stochastic Adaptive Particle Beam Tracker Using Meer Filter Feedback.

DTIC Science & Technology

1986-12-01

breakthrough required in controlling the beam location. In 1983, Zicker (27] conducted a feasibility study of a simple proportional gain controller... Zicker synthesized his stochastic controller designs from a deterministic optimal LQ controller assuming full state feedback. An LQ controller is a...34Merge" Method 2.5 Simlifying the eer Filter a Zicker ran a performance analysis on the Meer filter and found the Meer filter virtually insensitive to

Iterative Inverse Modeling for Reconciliation of Emission Inventories during the 2006 TexAQS Intensive Field Campaign

NASA Astrophysics Data System (ADS)

Xiao, X.; Cohan, D. S.

2009-12-01

Substantial uncertainties in current emission inventories have been detected by the Texas Air Quality Study 2006 (TexAQS 2006) intensive field program. These emission uncertainties have caused large inaccuracies in model simulations of air quality and its responses to management strategies. To improve the quantitative understanding of the temporal, spatial, and categorized distributions of primary pollutant emissions by utilizing the corresponding measurements collected during TexAQS 2006, we implemented both the recursive Kalman filter and a batch matrix inversion 4-D data assimilation (FDDA) method in an iterative inverse modeling framework of the CMAQ-DDM model. Equipped with the decoupled direct method, CMAQ-DDM enables simultaneous calculation of the sensitivity coefficients of pollutant concentrations to emissions to be used in the inversions. Primary pollutant concentrations measured by the multiple platforms (TCEQ ground-based, NOAA WP-3D aircraft and Ronald H. Brown vessel, and UH Moody Tower) during TexAQS 2006 have been integrated for the use in the inverse modeling. Firstly pseudo-data analyses have been conducted to assess the two methods, taking a coarse spatial resolution emission inventory as a case. Model base case concentrations of isoprene and ozone at arbitrarily selected ground grid cells were perturbed to generate pseudo measurements with different assumed Gaussian uncertainties expressed by 1-sigma standard deviations. Single-species inversions have been conducted with both methods for isoprene and NOx surface emissions from eight states in the Southeastern United States by using the pseudo measurements of isoprene and ozone, respectively. Utilization of ozone pseudo data to invert for NOx emissions serves only for the purpose of method assessment. Both the Kalman filter and FDDA methods show good performance in tuning arbitrarily shifted a priori emissions to the base case “true” values within 3-4 iterations even for the nonlinear responses of ozone to NOx emissions. While the Kalman filter has better performance under the situation of very large observational uncertainties, the batch matrix FDDA method is better suited for incorporating temporally and spatially irregular data such as those measured by NOAA aircraft and ship. After validating the methods with the pseudo data, the inverse technique is applied to improve emission estimates of NOx from different source sectors and regions in the Houston metropolitan area by using NOx measurements during TexAQS 2006. EPA NEI2005-based and Texas-specified Emission Inventories for 2006 are used as the a priori emission estimates before optimization. The inversion results will be presented and discussed. Future work will conduct inverse modeling for additional species, and then perform a multi-species inversion for emissions consistency and reconciliation with secondary pollutants such as ozone.

Electrically heated particulate filter restart strategy

DOEpatents

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

2011-07-12

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.

Integrating retention soil filters into urban hydrologic models - Relevant processes and important parameters

NASA Astrophysics Data System (ADS)

Bachmann-Machnik, Anna; Meyer, Daniel; Waldhoff, Axel; Fuchs, Stephan; Dittmer, Ulrich

2018-04-01

Retention Soil Filters (RSFs), a form of vertical flow constructed wetlands specifically designed for combined sewer overflow (CSO) treatment, have proven to be an effective tool to mitigate negative impacts of CSOs on receiving water bodies. Long-term hydrologic simulations are used to predict the emissions from urban drainage systems during planning of stormwater management measures. So far no universally accepted model for RSF simulation exists. When simulating hydraulics and water quality in RSFs, an appropriate level of detail must be chosen for reasonable balancing between model complexity and model handling, considering the model input's level of uncertainty. The most crucial parameters determining the resultant uncertainties of the integrated sewer system and filter bed model were identified by evaluating a virtual drainage system with a Retention Soil Filter for CSO treatment. To determine reasonable parameter ranges for RSF simulations, data of 207 events from six full-scale RSF plants in Germany were analyzed. Data evaluation shows that even though different plants with varying loading and operation modes were examined, a simple model is sufficient to assess relevant suspended solids (SS), chemical oxygen demand (COD) and NH4 emissions from RSFs. Two conceptual RSF models with different degrees of complexity were assessed. These models were developed based on evaluation of data from full scale RSF plants and column experiments. Incorporated model processes are ammonium adsorption in the filter layer and degradation during subsequent dry weather period, filtration of SS and particulate COD (XCOD) to a constant background concentration and removal of solute COD (SCOD) by a constant removal rate during filter passage as well as sedimentation of SS and XCOD in the filter overflow. XCOD, SS and ammonium loads as well as ammonium concentration peaks are discharged primarily via RSF overflow not passing through the filter bed. Uncertainties of the integrated simulation of the sewer system and RSF model mainly originate from the model parameters of the hydrologic sewer system model.

Measuring SO2 ship emissions with an ultraviolet imaging camera

NASA Astrophysics Data System (ADS)

Prata, A. J.

2014-05-01

Over the last few years fast-sampling ultraviolet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical emission rates ~ 1-10 kg s-1) and natural sources (e.g. volcanoes; typical emission rates ~ 10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and emission rates. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and emission rates of SO2 (typical emission rates ~ 0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the emission rates and path concentrations can be retrieved in real time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where SO2 emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and emission rates determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (> 10 Hz) from a single camera. Despite the ease of use and ability to determine SO2 emission rates from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes. A dual-camera system or a single, dual-filter camera is required in order to properly correct for the effects of particulates in ship plumes.

Experiments and analysis of tunable monolithic 1- μm single-frequency fiber lasers with loop mirror filters

NASA Astrophysics Data System (ADS)

Wang, Qi; Song, Huaqing; Wang, Xingpeng; Wang, Dongdong; Li, Li

2018-03-01

In this paper, we demonstrated thermally tunable 1- μm single-frequency fiber lasers utilizing loop mirror filters (LMFs) with unpumped Yb-doped fibers. The frequency selection and tracking was achieved by combining a fiber Bragg grating (FBG) and a dynamic grating established inside the LMF. The central emission wavelength was at 1064.07 nm with a tuning range of 1.4 nm, and the measured emission linewidth was less than 10 kHz. We also systematically studied the wavelength-tracking thermal stability of the LMF with separate thermal treatment upon the FBG and LMF, respectively. Finally, we presented a selection criterion for the minimum unpumped doped fiber length inside the LMF with experimental verification.

[Appropriate dust control measures for jade carving operations].

PubMed

Liu, Jiang; Wang, Qiushui; Liu, Guangquan

2002-12-01

To provide the appropriate dust control measures for jade carving operations. Dust concentrations in the workplace were measured according to GB/T 5748-85. Ventilation system of dust control were measured according to GB/T 16157-1996. Dust particle size distributions for different sources and particle size fraction collecting efficiencies of the dust collectors were measured with WY-1 in-stack 7 stage cascade impactors. On the basis of adopting wet process in the carving operations, local exhaust ventilation system for dust control was installed, which included: the special designed slot exhaust hoods with hood face velocity of 2.5 m/s and exhaust volume of 600 m3/h. The pipe sizes were determined according to the air volume passing through the pipe and the reasonable air velocities. Impinging scrubber or bag filter dust collector were selected to treat the dust laden air from the local exhaust ventilation system, which gave a total collecting efficiency of 97% for impinging scrubber and 98% for bag filter; The type of fan and its size were selected according to the total air volume of the ventilation system and maximum total pressure needed for the longest pipe line plus the pressure drop of the dust collector. Practical application showed that, after installation and use of the appropriate dust control measures, the dust concentrations in the workplaces could meet or nearly meet the national hygienic standard and the dust laden air at the local exhaust ventilation system could meet the national emission standard.

Characterization of Horizontally-Issuing Reacting Buoyant Jets

DTIC Science & Technology

2011-03-01

125 Appendix B : Unfiltered High Speed Imaging Results ....................................................139 Appendix C: CH* Filtered High...and ( b ) Negative Buoyancy (16) ... 15 Figure 4. (a) Flame and ( b ) Nonflame Combustion in a Spark-Ignition Engine (26) ...... 27 Figure 5. Laminar...a) Fluorescent absorption and emission b ) Emission spectra (30) .................... 41 Figure 9. The X and A Energy States (29

Demonstration of Diesel Engine Air Emissions Reduction Technologies

DTIC Science & Technology

2008-12-01

16 Figure 5. Plots of Cheyenne Mountain Operating Cycle and Reference CBD Driving...Air Act CARB California Air Resources Board CBD Central Business District CCR California Code of Regulations CES Cummins Emissions Solutions CFR...matter ppb parts per billion ppm parts per million PuriNOx Proprietary Water / Diesel Emulsified Fuel RPF robust particulate filter THC total

Simulation of Na D emission near Europa during eclipse

USGS Publications Warehouse

Cassidy, T.A.; Johnson, R.E.; Geissler, P.E.; Leblanc, F.

2008-01-01

The Cassini imaging science subsystem observed Europa in eclipse during Cassini's Jupiter flyby. The disk-resolved observations revealed a spatially nonuniform emission in the wavelength range of 200-1050 nm (clear filters). By building on observations and simulations of Europa's Na atmosphere and torus we find that electron-excited Na in Europa's tenuous atmosphere can account for the observed emission if the Na is ejected preferentially from Europa's dark terrain. Copyright 2008 by the American Geophysical Union.

The Air Pollution Exposure Laboratory (APEL) for controlled human exposure to diesel exhaust and other inhalants: characterization and comparison to existing facilities.

PubMed

Birger, Nicholas; Gould, Timothy; Stewart, James; Miller, Mark R; Larson, Timothy; Carlsten, Chris

2011-03-01

The Air Pollution Exposure Laboratory (APEL) was designed for the controlled inhalation of human subjects to aged and diluted diesel exhaust (DE) to mimic "real-world" occupational and environmental conditions. An EPA Tier 3-compliant, 6.0 kW diesel generator is operated under discrete cyclic loads to simulate diesel on-road emissions. The engine accepts standard ultra-low sulfur diesel or a variety of alternative fuels (such as biodiesel) via a partitioned tank. A portion of raw exhaust is drawn into the primary dilution system and is diluted 9:1 with compressed air at standard temperature (20°C) and humidity (40%) levels. The exhaust is further diluted approximately 25:1 by high efficiency particulate air (HEPA)-filtered air (FA) and then aged for 4 min before entering the 4 × 6 × 7-foot exposure booth. An optional HEPA filter path immediately proximal to the booth can generate a particle-reduced (gas-enriched) exposure. In-booth particulate is read by a nephelometer to provide an instantaneous light scattering coefficient for closed-loop system control. A Scanning Mobility Particle Sizer and multi-stage impactor measures particle size distribution. Filter sampling allows determination of sessional average concentrations of size-fractionated and unfractionated particulate oxidative potential, elemental carbon, organic carbon and trace elements. Approximately 300 μg/m(3) PM(2.5) is routinely achievable at APEL and is well characterized in terms of oxidative potential and elemental components. APEL efficiently creates fresh DE, appropriately aged and diluted for human experimentation at safe yet realistic concentrations. Description of exposure characteristics allows comparison to other international efforts to deepen the current evidence base regarding the health effects of DE.

Searching for Dwarf H Alpha Emission-line Galaxies within Voids III: First Spectra

NASA Astrophysics Data System (ADS)

Moody, J. Ward; Draper, Christian; McNeil, Stephen; Joner, Michael D.

2017-02-01

The presence or absence of dwarf galaxies with {M}r\\prime > -14 in low-density voids is determined by the nature of dark matter halos. To better understand what this nature is, we are conducting an imaging survey through redshifted Hα filters to look for emission-line dwarf galaxies in the centers of two nearby galaxy voids called FN2 and FN8. Either finding such dwarfs or establishing that they are not present is a significant result. As an important step in establishing the robustness of the search technique, we have observed six candidates from the survey of FN8 with the Gillett Gemini telescope and GMOS spectrometer. All of these candidates had emission, although none was Hα. The emission in two objects was the [O III]λ4959, 5007 doublet plus Hβ, and the emission in the remaining four was the [O II]λ3727 doublet, all from objects beyond the void. While no objects were within the void, these spectra show that the survey is capable of finding emission-line dwarfs in the void centers that are as faint as {M}r\\prime ˜ -12.4, should they be present. These spectra also show that redshifts estimated from our filtered images are accurate to several hundred km s-1 if the line is identified correctly, encouraging further work in finding ways to conduct redshift surveys through imaging alone.

Wave-filter-based approach for generation of a quiet space in a rectangular cavity

NASA Astrophysics Data System (ADS)

Iwamoto, Hiroyuki; Tanaka, Nobuo; Sanada, Akira

2018-02-01

This paper is concerned with the generation of a quiet space in a rectangular cavity using active wave control methodology. It is the purpose of this paper to present the wave filtering method for a rectangular cavity using multiple microphones and its application to an adaptive feedforward control system. Firstly, the transfer matrix method is introduced for describing the wave dynamics of the sound field, and then feedforward control laws for eliminating transmitted waves is derived. Furthermore, some numerical simulations are conducted that show the best possible result of active wave control. This is followed by the derivation of the wave filtering equations that indicates the structure of the wave filter. It is clarified that the wave filter consists of three portions; modal group filter, rearrangement filter and wave decomposition filter. Next, from a numerical point of view, the accuracy of the wave decomposition filter which is expressed as a function of frequency is investigated using condition numbers. Finally, an experiment on the adaptive feedforward control system using the wave filter is carried out, demonstrating that a quiet space is generated in the target space by the proposed method.

Design and implementation of a dual-wavelength intrinsic fluorescence camera system

NASA Astrophysics Data System (ADS)

Ortega-Martinez, Antonio; Musacchia, Joseph J.; Gutierrez-Herrera, Enoch; Wang, Ying; Franco, Walfre

2017-03-01

Intrinsic UV fluorescence imaging is a technique that permits the observation of spatial differences in emitted fluorescence. It relies on the fluorescence produced by the innate fluorophores in the sample, and thus can be used for marker-less in-vivo assessment of tissue. It has been studied as a tool for the study of the skin, specifically for the classification of lesions, the delimitation of lesion borders and the study of wound healing, among others. In its most basic setup, a sample is excited with a narrow-band UV light source and the resulting fluorescence is imaged with a UV sensitive camera filtered to the emission wavelength of interest. By carefully selecting the excitation/emission pair, we can observe changes in fluorescence associated with physiological processes. One of the main drawbacks of this simple setup is the inability to observe more than a single excitation/emission pair at the same time, as some phenomena are better studied when two or more different pairs are studied simultaneously. In this work, we describe the design and the hardware and software implementation of a dual wavelength portable UV fluorescence imaging system. Its main components are an UV camera, a dual wavelength UV LED illuminator (295 and 345 nm) and two different emission filters (345 and 390 nm) that can be swapped by a mechanical filter wheel. The system is operated using a laptop computer and custom software that performs basic pre-processing to improve the image. The system was designed to allow us to image fluorescent peaks of tryptophan and collagen cross links in order to study wound healing progression.

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

DOE PAGES

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.; ...

2016-10-17

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Nano-metal oxides: Exposure and engineering control assessment.

PubMed

Garcia, Alberto; Eastlake, Adrienne; Topmiller, Jennifer L; Sparks, Christopher; Martinez, Kenneth; Geraci, Charles L

2017-09-01

In January 2007, the National Institute for Occupational Safety and Health (NIOSH) conducted a field study to evaluate process specific emissions during the production of ENMs. This study was performed using the nanoparticle emission assessment technique (NEAT). During this study, it was determined that ENMs were released during production and cleaning of the process reactor. Airborne concentrations of silver, nickel, and iron were found both in the employee's personal breathing zone and area samples during reactor cleaning. At the completion of this initial survey, it was suggested that a flanged attachment be added to the local exhaust ventilation system.  NIOSH re-evaluated the facility in December 2011 to assess worker exposures following an increase in production rates. This study included a fully comprehensive emissions, exposure, and engineering control evaluation of the entire process. This study made use of the nanoparticle exposure assessment technique (NEAT 2.0). Data obtained from filter-based samples and direct reading instruments indicate that reactor cleanout increased the overall particle concentration in the immediate area. However, it does not appear that these concentrations affect areas outside of the production floor. As the distance between the reactor and the sample location increased, the observed particle number concentration decreased, creating a concentration gradient with respect to the reactor. The results of this study confirm that the flanged attachment on the local exhaust ventilation system served to decrease exposure potential.  Given the available toxicological data of the metals evaluated, caution is warranted. One should always keep in mind that occupational exposure levels were not developed specifically for nanoscale particles. With data suggesting that certain nanoparticles may be more toxic than the larger counterparts of the same material; employers should attempt to control emissions of these particles at the source, to limit the potential for exposure.

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

An approach towards risk assessment for the use of a synergistic metallic diesel particulate filter (DPF) regeneration additive

NASA Astrophysics Data System (ADS)

Cook, S. L.; Richards, P. J.

The motivations for legislation to set diesel emissions limits requiring the use of diesel particulate filters (DPF) are summarised. If the DPF is to be used, demonstration of regeneration (combustion of collected carbonaceous material) without additional emission problems is important. Potential metal emissions resulting from use of a synergistic Fe/Sr fuel-borne DPF regeneration catalyst are evaluated. Measurements over legislated drive cycle estimate the metals to comprise 1-2% of the solid material emitted, and the DPF to collect >99% of such material. Diesel particulate matter is used as a marker, and from existing air quality and emission inventory measurements, maximum conceivable increases of <1 ng m -3 and <250 pg m -3 for iron and strontium, respectively, are calculated. From environmental assessment levels, derived from occupational exposure limits, these are not significant. For humans, daily ingress of airborne Sr is estimated at 3.5 ng. This is small compared to the known Sr contents of lungs, blood and the daily diet. In the context of reductions of other metals, particulate matter and pollutant emissions, the overall assessment is that the use of these metals to enable use of a DPF allows significant net environmental benefit to be obtained.