Update of the development on the new Audi NSU rotary engine generation

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

van Basshuysen, R.; Wilmers, G.

At AUDI NSU a new generation of rotary engines has been developed of which the significant layout parameters are outlined. The present status of development is characterized by a lean burn concept with fuel injection and an exhaust emission control system with catalytic converter. Test results indicate that the fuel economy ranges at the same level as comparable reciprocating engines. The future US-exhaust emission standards are kept below but in respect to the Japanese standards further reduction of NO/sub x/ is necessary. Endurance tests proving the durability of the exhaust emission control system have still to be performed.

Spin-controlled ultrafast vertical-cavity surface-emitting lasers

NASA Astrophysics Data System (ADS)

Höpfner, Henning; Lindemann, Markus; Gerhardt, Nils C.; Hofmann, Martin R.

2014-05-01

Spin-controlled semiconductor lasers are highly attractive spintronic devices providing characteristics superior to their conventional purely charge-based counterparts. In particular, spin-controlled vertical-cavity surface emitting lasers (spin-VCSELs) promise to offer lower thresholds, enhanced emission intensity, spin amplification, full polarization control, chirp control and ultrafast dynamics. Most important, the ability to control and modulate the polarization state of the laser emission with extraordinarily high frequencies is very attractive for many applications like broadband optical communication and ultrafast optical switches. We present a novel concept for ultrafast spin-VCSELs which has the potential to overcome the conventional speed limitation for directly modulated lasers by the relaxation oscillation frequency and to reach modulation frequencies significantly above 100 GHz. The concept is based on the coupled spin-photon dynamics in birefringent micro-cavity lasers. By injecting spin-polarized carriers in the VCSEL, oscillations of the coupled spin-photon system can by induced which lead to oscillations of the polarization state of the laser emission. These oscillations are decoupled from conventional relaxation oscillations of the carrier-photon system and can be much faster than these. Utilizing these polarization oscillations is thus a very promising approach to develop ultrafast spin-VCSELs for high speed optical data communication in the near future. Different aspects of the spin and polarization dynamics, its connection to birefringence and bistability in the cavity, controlled switching of the oscillations, and the limitations of this novel approach will be analysed theoretically and experimentally for spin-polarized VCSELs at room temperature.

Ecotechnology: basis of a new immission concept in water pollution control.

PubMed

Benndorf, J

2005-01-01

Beyond the traditional load reduction also an ecosystem-internal mechanism can be used to minimise the effects of water pollution. The control of the internal mechanisms is achieved through the optimisation of the ecosystem structure. This ecotechnology principle is based on the idea to reduce as much as possible the gap between the current (suboptimal) structural status and the optimum structure by intentional manipulations. The spectrum of such manipulations is very broad. A few examples are demonstrated. They comprise physical (e.g. stream morphology), chemical (e.g. enhancing the redox potential at the sediment-water interface) and biological (e.g. enhancing stocks of predatory fishes) control measures. It can be supposed that a new immission concept including the ecotechnology principle could be much more adequate to the demand of modern water pollution control than the traditional emission and imission concepts.

Engine design considerations for 2nd generation supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.

1975-01-01

The environmental and economic goals projected for advanced supersonic transports will require revolutionary improvements in propulsion systems. Variable cycle engine concepts that incorporate unique components and advanced technologies show promise in meeting these goals. Pratt & Whitney Aircraft is conducting conceptual design studies of variable cycle engine concepts under NASA sponsorship. This paper reviews some of the design considerations for these engine concepts. Emphasis is placed on jet noise abatement, reduction of emissions, performance improvements, installation considerations, hot-section characteristics and control system requirements. Two representative variable cycle engine concepts that incorporate these basic design considerations are described.

Broad specification fuels combustion technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Ekstedt, E. E.

1984-01-01

Design and development efforts to evolve promising aircraft gas turbine combustor configurations for burning broadened-properties fuels were discussed. Design and experimental evaluations of three different combustor concepts in sector combustor rig tests was conducted. The combustor concepts were a state of the art single-annular combustor, a staged double-annular combustor, and a short single-annular combustor with variable geometry to control primary zone stoichiometry. A total of 25 different configurations of the three combustor concepts were evaluated. Testing was conducted over the full range of CF6-80A engine combustor inlet conditions, using four fuels containing between 12% and 14% hydrogen by weight. Good progress was made toward meeting specific program emissions and performance goals with each of the three combustor concepts. The effects of reduced fuel hydrogen content, including increased flame radiation, liner metal temperature, smoke, and NOx emissions were documented. The most significant effect on the baseline combustor was a projected 33% life reduction, for a reduction from 14% to 13% fuel hydrogen content, due to increased liner temperatures.

Controlling upconversion nanocrystals for emerging applications

NASA Astrophysics Data System (ADS)

Zhou, Bo; Shi, Bingyang; Jin, Dayong; Liu, Xiaogang

2015-11-01

Lanthanide-doped upconversion nanocrystals enable anti-Stokes emission with pump intensities several orders of magnitude lower than required by conventional nonlinear optical techniques. Their exceptional properties, namely large anti-Stokes shifts, sharp emission spectra and long excited-state lifetimes, have led to a diversity of applications. Here, we review upconversion nanocrystals from the perspective of fundamental concepts and examine the technical challenges in relation to emission colour tuning and luminescence enhancement. In particular, we highlight the advances in functionalization strategies that enable the broad utility of upconversion nanocrystals for multimodal imaging, cancer therapy, volumetric displays and photonics.

Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

2004-01-01

This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

Evaluation of an Aircraft Concept With Over-Wing, Hydrogen-Fueled Engines for Reduced Noise and Emissions

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Olson, Erik D.

2002-01-01

This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A strut-braced wing configuration with overwing, ultra-high bypass ratio, hydrogen fueled turbofan engines is considered. Estimated noise and emission characteristics are compared to a conventional configuration designed for the same mission and significant benefits are identified. The design challenges and technology issues which would have to be addressed to make the concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program seeks to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify enabling advanced technology requirements for the concepts.

Solid state SPS microwave generation and transmission study. Volume 2, phase 2: Appendices

NASA Technical Reports Server (NTRS)

Maynard, O. E.

1980-01-01

The solid state sandwich concept for SPS was further defined. The design effort concentrated on the spacetenna, but did include some system analysis for parametric comparison reasons. Basic solid state microwave devices were defined and modeled. An initial conceptual subsystems and system design was performed as well as sidelobe control and system selection. The selected system concept and parametric solid state microwave power transmission system data were assessed relevant to the SPS concept. Although device efficiency was not a goal, the sensitivities to design of this efficiency were parametrically treated. Sidelobe control consisted of various single step tapers, multistep tapers and Gaussian tapers. A hybrid concept using tubes and solid state was evaluated. Thermal analyses are included with emphasis on sensitivities to waste heat radiator form factor, emissivity, absorptivity, amplifier efficiency, material and junction temperature.

VSCE technology definition study

NASA Technical Reports Server (NTRS)

Howlett, R. A.; Hunt, R. B.

1979-01-01

Refined design definition of the variable stream control engine (VSCE) concept for advanced supersonic transports is presented. Operating and performance features of the VSCE are discussed, including the engine components, thrust specific fuel consumption, weight, noise, and emission system. A preliminary engine design is presented.

MEMS Louvers for Thermal Control

NASA Technical Reports Server (NTRS)

Champion, J. L.; Osiander, R.; Darrin, M. A. Garrison; Swanson, T. D.

1998-01-01

Mechanical louvers have frequently been used for spacecraft and instrument thermal control purposes. These devices typically consist of parallel or radial vanes, which can be opened or closed to vary the effective emissivity of the underlying surface. This project demonstrates the feasibility of using Micro-Electromechanical Systems (MEMS) technology to miniaturize louvers for such purposes. This concept offers the possibility of substituting the smaller, lighter weight, more rugged, and less costly MEMS devices for such mechanical louvers. In effect, a smart skin that self adjusts in response to environmental influences could be developed composed of arrays of thousands of miniaturized louvers. Several orders of magnitude size, weight, and volume decreases are potentially achieved using micro-electromechanical techniques. The use of this technology offers substantial benefits in spacecraft/instrument design, integration and testing, and flight operations. It will be particularly beneficial for the emerging smaller spacecraft and instruments of the future. In addition, this MEMS thermal louver technology can form the basis for related spacecraft instrument applications. The specific goal of this effort was to develop a preliminary MEMS device capable of modulating the effective emissivity of radiators on spacecraft. The concept pursued uses hinged panels, or louvers, in a manner such that heat emitted from the radiators is a function of louver angle. An electrostatic comb drive or other such actuator can control the louver position. The initial design calls for the louvers to be gold coated while the underlying surface is of high emissivity. Since, the base MEMS material, silicon, is transparent in the InfraRed (IR) spectrum, the device has a minimum emissivity when closed and a maximum emissivity when open. An initial set of polysilicon louver devices was designed at the Johns Hopkins Applied Physics Laboratory in conjunction with the Thermal Engineering Branch at NASA's Goddard Space Flight Center.

Screening analysis and selection of emission reduction concepts for intermittent combustion aircraft engines

NASA Technical Reports Server (NTRS)

Rezy, B. J.; Meyers, J. E.; Tucker, J. R.; Stuckas, S. J.

1976-01-01

An analysis was conducted to screen, evaluate, and select three engine exhaust emission reduction concepts from a group of 14 candidate alternatives. A comprehensive literature search was conducted to survey the emission reduction technology state-of-the-art and establish contact with firms working on intermittent combustion engine development and pollution reduction problems. Concept development, advantages, disadvantages, and expected emission reduction responses are stated. A set of cost effectiveness criteria was developed, appraised for relative importance, and traded off against each concept so that its merit could be determined. A decision model was used to aid the evaluators in managing the criteria, making consistent judgements, calculating merit scores, and ranking the concepts. An Improved Fuel Injection System, Improved Cooling Combustion Chamber, and a Variable Timing Ignition System were recommended to NASA for approval and further concept development. An alternate concept, Air Injection, was also recommended.

Pollution reduction technology program for small jet aircraft engines, phase 1

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1977-01-01

A series of combustor pressure rig screening tests was conducted on three combustor concepts applied to the TFE731-2 turbofan engine combustion system for the purpose of evaluating their relative emissions reduction potential consistent with prescribed performance, durability, and envelope contraints. The three concepts and their modifications represented increasing potential for reducing emission levels with the penalty of increased hardware complexity and operational risk. Concept 1 entailed advanced modifications to the present production TFE731-2 combustion system. Concept 2 was based on the incorporation of an axial air-assisted airblast fuel injection system. Concept 3 was a staged premix/prevaporizing combustion system. Significant emissions reductions were achieved in all three concepts, consistent with acceptable combustion system performance. Concepts 2 and 3 were identified as having the greatest achievable emissions reduction potential, and were selected to undergo refinement to prepare for ultimate incorporation within an engine.

Solid state SPS microwave generation and transmission study. Volume 1: Phase 2

NASA Technical Reports Server (NTRS)

Maynard, O. E.

1980-01-01

The solid state sandwich concept for Solar Power Station (SPS) was investigated. The design effort concentrated on the spacetenna, but did include some system analysis for parametric comparison reasons. The study specifically included definition and math modeling of basic solid state microwave devices, an initial conceptual subsystems and system design, sidelobe control and system selection, an assessment of selected system concept and parametric solid state microwave power transmission system data relevant to the SPS concept. Although device efficiency was not a goal, the sensitivities to design of this efficiency were parametrically treated. Sidelobe control consisted of various single step tapers, multistep tapers, and Gaussian tapers. A preliminary assessment of a hybrid concept using tubes and solid state is also included. There is a considerable amount of thermal analysis provided with emphasis on sensitivities to waste heat radiator form factor, emissivity, absorptivity, amplifier efficiency, material and junction temperature.

The NASA broad-specification fuels combustion technology program: An assessment of phase 1 test results

NASA Technical Reports Server (NTRS)

Fear, J. S.

1983-01-01

An assessment is made of the results of Phase 1 screening testing of current and advanced combustion system concepts using several broadened-properties fuels. The severity of each of several fuels-properties effects on combustor performance or liner life is discussed, as well as design techniques with the potential to offset these adverse effects. The selection of concepts to be pursued in Phase 2 refinement testing is described. This selection takes into account the relative costs and complexities of the concepts, the current outlook on pollutant emissions control, and practical operational problems.

Strategies for emission reduction of air pollutants produced from a chemical plant.

PubMed

Lee, Byeong-Kyu; Cho, Sung-Woong

2003-01-01

Various air pollution control (APC) techniques were employed in order to reduce emissions of air pollutants produced from chemical plants, which have many different chemical production facilities. For an emission reduction of acid gases, this study employed a method to improve solubility of pollutants by decreasing the operating temperature of the scrubbers, increasing the surface area for effective contact of gas and liquid, and modifying processes in the acid scrubbers. To reduce emission of both amines and acid gases, pollutant gas components were first separated, then condensation and/or acid scrubbing, depending on the chemical and physical properties of pollutant components, were used. To reduce emission of solvents, condensation and activated carbon adsorption were employed. To reduce emission of a mixture gases containing acid gases and solvents, the mixed gases were passed into the first condenser, the acid scrubber, the second condenser, and the activated carbon adsorption tower in sequence. As a strategy to reduce emission of pollutants at the source, this study also employed the simple pollution prevention concept of modification of the previously operating APC control device. Finally, air emissions of pollutants produced from the chemical plants were much more reduced by applying proper APC methods, depending upon the types (physical or chemical properties) and the specific emission situations of pollutants.

Internal combustion engine report: Spark ignited ICE GenSet optimization and novel concept development

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

Keller, J.; Blarigan, P. Van

1998-08-01

In this manuscript the authors report on two projects each of which the goal is to produce cost effective hydrogen utilization technologies. These projects are: (1) the development of an electrical generation system using a conventional four-stroke spark-ignited internal combustion engine generator combination (SI-GenSet) optimized for maximum efficiency and minimum emissions, and (2) the development of a novel internal combustion engine concept. The SI-GenSet will be optimized to run on either hydrogen or hydrogen-blends. The novel concept seeks to develop an engine that optimizes the Otto cycle in a free piston configuration while minimizing all emissions. To this end themore » authors are developing a rapid combustion homogeneous charge compression ignition (HCCI) engine using a linear alternator for both power take-off and engine control. Targeted applications include stationary electrical power generation, stationary shaft power generation, hybrid vehicles, and nearly any other application now being accomplished with internal combustion engines.« less

Control of odor and VOC emissions at wastewater treatment plants: Boston Harbor case study

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

Getter, R.; Breen, C.; Laquidara, M.

1994-12-31

Siting of the new wastewater treatment plant (WWTP) for the Massachusetts Water Resources Authority (MWRA) in Boston was based on an assumption of mitigation of total reduced sulfur (TRS) and volatile organic compound (VOC) emissions. Collection and treatment of exhaust streams from potential emission sources was recommended. Best Available Control Technology (BACT) for VOC control was conservatively suggested to consist of wet by carbon adsorption based on initial sampling performed in 1988 during facilities planning, which estimated uncontrolled VOC emissions in excess of 1,000 tons per year. This concept was carried forward to the design phase in 1990, concurrent withmore » an extensive air emissions testing and pilot treatment program at the NMRA`s existing primary treatment plant. Results of the pilot program, however, indicated source VOC concentrations well below what was expected as a result of the initial sampling study. Use of the 1990 pilot data in a top-down BACT analysis led to a recommendation to reconsider VOC control with carbon adsorption on the basis of prohibitive cost. This paper summarizes the background and permitting approach for five new odor control facilities on Deer Island for the Boston Harbor Project, with emphasis on the new primary treatment facilities. The paper also presents results from the 1990 emissions characterization and pilot program, providing generally applicable ideas for solving the difficulties of characterizing and estimating emissions for WWTPS. Results from operation of the pilot facilities illustrate the effectiveness of met scrubbing and carbon adsorption in removing TRS and VOCs from wastewater treatment exhaust air streams. In addition, pilot program results indicate the importance of flexibility in design of odor control systems to accommodate variations in concentrations of TRS and VOCS.« less

Reducing Carbon Dioxide Emissions: Using the Mole Concept.

ERIC Educational Resources Information Center

Myers, Alan

2002-01-01

Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)

Particulate Emission Abatement for Krakow Boilerhouses

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

NONE

1998-09-14

Environmental cleanup and pollution control are considered the foremost national priorities in Poland. The target of this cleanup is the Polish coal industry, which supplies the fuel to generate over 78% of Poland`s primary energy production. This project addresses the problem of airborne dust and uncontrolled particulate emissions from boilerhouses, which represent a large fraction of the total in Poland. In Krakow alone, there are numerous uncontrolled boilers accounting for about half the total fuel use. The large number of low-capacity boilers poses both technical and economic challenges, since the cost of control equipment is a significant factor in themore » reduction of emissions. A new concept in dust collection, called a Core Separator, is proposed for this important application. The Core Separator is an advanced technology developed through research sponsored by the Department of Energy.« less

Results and status of the NASA aircraft engine emission reduction technology programs

NASA Technical Reports Server (NTRS)

Jones, R. E.; Diehl, L. A.; Petrash, D. A.; Grobman, J.

1978-01-01

The results of an aircraft engine emission reduction study are reviewed in detail. The capability of combustor concepts to produce significantly lower levels of exhaust emissions than present production combustors was evaluated. The development status of each combustor concept is discussed relative to its potential for implementation in aircraft engines. Also, the ability of these combustor concepts to achieve proposed NME and NCE EPA standards is discussed.

The on-board tailpipe emissions measurement system (TOTEMS) : proof\\0x2010 of\\0x2010concept.

DOT National Transportation Integrated Search

2009-06-03

An on-board tailpipe emissions instrumentation system was designed, assembled and tested as proof-of-concept : for the University of Vermonts Transportation Research Center (TRC) Signature Project #2 real-world vehicle : emissions data colle...

Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

NASA Astrophysics Data System (ADS)

Chen, Xiangyu; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei

2015-09-01

A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm2, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

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

Chen, Xiangyu, E-mail: chenxiangyu@binn.cas.cn, E-mail: ouyangwei@phy.ecnu.edu.cn; Jiang, Tao; Sun, Zhuo

A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current.more » The minimum contact area for the TENG to generate field emission is about 9 cm{sup 2}, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.« less

Diffusion-controlled reference material for VOC emissions testing: proof of concept.

PubMed

Cox, S S; Liu, Z; Little, J C; Howard-Reed, C; Nabinger, S J; Persily, A

2010-10-01

Because of concerns about indoor air quality, there is growing awareness of the need to reduce the rate at which indoor materials and products emit volatile organic compounds (VOCs). To meet consumer demand for low emitting products, manufacturers are increasingly submitting materials to independent laboratories for emissions testing. However, the same product tested by different laboratories can result in very different emissions profiles because of a general lack of test validation procedures. There is a need for a reference material that can be used as a known emissions source and that will have the same emission rate when tested by different laboratories under the same conditions. A reference material was created by loading toluene into a polymethyl pentene film. A fundamental emissions model was used to predict the toluene emissions profile. Measured VOC emissions profiles using small-chamber emissions tests compared reasonably well to the emissions profile predicted using the emissions model, demonstrating the feasibility of the proposed approach to create a diffusion-controlled reference material. To calibrate emissions test chambers and improve the reproducibility of VOC emission measurements among different laboratories, a reference material has been created using a polymer film loaded with a representative VOC. Initial results show that the film's VOC emission profile measured in a conventional test chamber compares well to predictions based on independently determined material/chemical properties and a fundamental emissions model. The use of such reference materials has the potential to build consensus and confidence in emissions testing as well as 'level the playing field' for product testing laboratories and manufacturers.

Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

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

Sekar, R.R.; Marr, W.W.; Cole, R.L.

1990-01-01

The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion airmore » had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.« less

The greenhouse gas and energy balance of different treatment concepts for bio-waste.

PubMed

Ortner, Maria E; Müller, Wolfgang; Bockreis, Anke

2013-10-01

The greenhouse gas (GHG) and energy performance of bio-waste treatment plants been investigated for three characteristic bio-waste treatment concepts: composting; biological drying for the production of biomass fuel fractions; and anaerobic digestion. Compared with other studies about the environmental impacts of bio-waste management, this study focused on the direct comparison of the latest process concepts and state-of-the-art emission control measures. To enable a comparison, the mass balance and products were modelled for all process concepts assuming the same bio-waste amounts and properties. In addition, the value of compost as a soil improver was included in the evaluation, using straw as a reference system. This aspect has rarely been accounted for in other studies. The study is based on data from operational facilities combined with literature data. The results show that all three concepts contribute to a reduction of GHG emissions and show a positive balance for cumulated energy demand. However, in contrast to other studies, the advantage of anaerobic digestion compared with composting is smaller as a result of accounting for the soil improving properties of compost. Still, anaerobic digestion is the environmentally superior solution. The results are intended to inform decision makers about the relevant aspects of bio-waste treatment regarding the environmental impacts of different bio-waste management strategies.

Reactivity-controlled compression ignition drive cycle emissions and fuel economy estimations using vehicle system simulations

DOE PAGES

Curran, Scott J.; Gao, Zhiming; Wagner, Robert M.

2014-12-22

In-cylinder blending of gasoline and diesel to achieve reactivity-controlled compression ignition has been shown to reduce NO X and soot emissions while maintaining or improving brake thermal efficiency as compared with conventional diesel combustion. The reactivity-controlled compression ignition concept has an advantage over many advanced combustion strategies in that the fuel reactivity can be tailored to the engine speed and load, allowing stable low-temperature combustion to be extended over more of the light-duty drive cycle load range. In this paper, a multi-mode reactivity-controlled compression ignition strategy is employed where the engine switches from reactivity-controlled compression ignition to conventional diesel combustionmore » when speed and load demand are outside of the experimentally determined reactivity-controlled compression ignition range. The potential for reactivity-controlled compression ignition to reduce drive cycle fuel economy and emissions is not clearly understood and is explored here by simulating the fuel economy and emissions for a multi-mode reactivity-controlled compression ignition–enabled vehicle operating over a variety of US drive cycles using experimental engine maps for multi-mode reactivity-controlled compression ignition, conventional diesel combustion, and a 2009 port-fuel injected gasoline engine. Drive cycle simulations are completed assuming a conventional mid-size passenger vehicle with an automatic transmission. Multi-mode reactivity-controlled compression ignition fuel economy simulation results are compared with the same vehicle powered by a representative 2009 port-fuel injected gasoline engine over multiple drive cycles. Finally, engine-out drive cycle emissions are compared with conventional diesel combustion, and observations regarding relative gasoline and diesel tank sizes needed for the various drive cycles are also summarized.« less

Reactivity-based industrial volatile organic compounds emission inventory and its implications for ozone control strategies in China

NASA Astrophysics Data System (ADS)

Liang, Xiaoming; Chen, Xiaofang; Zhang, Jiani; Shi, Tianli; Sun, Xibo; Fan, Liya; Wang, Liming; Ye, Daiqi

2017-08-01

Increasingly serious ozone (O3) pollution, along with decreasing NOx emission, is creating a big challenge in the control of volatile organic compounds (VOCs) in China. More efficient and effective measures are assuredly needed for controlling VOCs. In this study, a reactivity-based industrial VOCs emission inventory was established in China based on the concept of ozone formation potential (OFP). Key VOCs species, major VOCs sources, and dominant regions with high reactivity were identified. Our results show that the top 15 OFP-based species, including m/p-xylene, toluene, propene, o-xylene, and ethyl benzene, contribute 69% of the total OFP but only 30% of the total emission. The architectural decoration industry, oil refinery industry, storage and transport, and seven other sources constituted the top 10 OFP subsectors, together contributing a total of 85%. The provincial and spatial characteristics of OFP are generally consistent with those of mass-based inventory. The implications for O3 control strategies in China are discussed. We propose a reactivity-based national definition of VOCs and low-reactive substitution strategies, combined with evaluations of health risks. Priority should be given to the top 15 or more species with high reactivity through their major emission sources. Reactivity-based policies should be flexibly applied for O3 mitigation based on the sensitivity of O3 formation conditions.

Development of the Flame Test Concept Inventory: Measuring Student Thinking about Atomic Emission

ERIC Educational Resources Information Center

Bretz, Stacey Lowery; Murata Mayo, Ana Vasquez

2018-01-01

This study reports the development of a 19-item Flame Test Concept Inventory, an assessment tool to measure students' understanding of atomic emission. Fifty-two students enrolled in secondary and postsecondary chemistry courses were interviewed about atomic emission and explicitly asked to explain flame test demonstrations and energy level…

Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

2012-01-01

Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to a normally unstable high-power condition, thus enabling the high-power condition.

On-chip electrically controlled routing of photons from a single quantum dot

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

Bentham, C.; Coles, R. J.; Royall, B.

2015-06-01

Electrical control of on-chip routing of photons emitted by a single InAs/GaAs self-assembled quantum dot (SAQD) is demonstrated in a photonic crystal cavity-waveguide system. The SAQD is located inside an H1 cavity, which is coupled to two photonic crystal waveguides. The SAQD emission wavelength is electrically tunable by the quantum-confined Stark effect. When the SAQD emission is brought into resonance with one of two H1 cavity modes, it is preferentially routed to the waveguide to which that mode is selectively coupled. This proof of concept provides the basis for scalable, low-power, high-speed operation of single-photon routers for use in integratedmore » quantum photonic circuits.« less

The Ferrofluids Story

NASA Technical Reports Server (NTRS)

1993-01-01

A new Ferrofluidics exclusion seal promises improvement in controlling "fugitive emissions" -vapors that escape into the atmosphere from petroleum refining and chemical processing facilities. These are primarily volatile organic compounds, and their emissions are highly regulated by the EPA. The ferrofluid system consists of a primary mechanical seal working in tandem with a secondary seal. Ferrofluids are magnetic liquids - fluids in which microscopic metal particles have been suspended, allowing the liquid to be controlled by a magnetic force. The concept was developed in the early years of the Space program, but never used. Two Avco scientists, however, saw commercial potential in ferrofluids and formed a company. Among exclusion seal commercial applications are rotary feedthrough seals, hydrodynamic bearings and fluids for home and automotive loudspeakers. Ferrofluidics has subsidiaries throughout the world.

Optical Control of Fluorescence through plasmonic eigenmode extinction

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

Xu, Xiaoying; Lin, Shih-Che; Li, Quanshui

We introduce the concept of optical control of the fluorescence yield of CdSe quantum dots through plasmon-induced structural changes in random semicontinuous nanostructured gold films. We demonstrate that the wavelength- and polarization dependent coupling between quantum dots and the semicontinuous films, and thus the fluorescent emission spectrum, can be controlled and significantly increased through the optical extinction of a selective band of eigenmodes in the films. This optical method of effecting controlled changes in the metal nanostructure allows for versatile functionality in a single sample and opens a pathway to in situ control over the fluorescence spectrum.

Optical Control of Fluorescence through plasmonic eigenmode extinction

DOE PAGES

Xu, Xiaoying; Lin, Shih-Che; Li, Quanshui; ...

2015-04-30

We introduce the concept of optical control of the fluorescence yield of CdSe quantum dots through plasmon-induced structural changes in random semicontinuous nanostructured gold films. We demonstrate that the wavelength- and polarization dependent coupling between quantum dots and the semicontinuous films, and thus the fluorescent emission spectrum, can be controlled and significantly increased through the optical extinction of a selective band of eigenmodes in the films. This optical method of effecting controlled changes in the metal nanostructure allows for versatile functionality in a single sample and opens a pathway to in situ control over the fluorescence spectrum.

Acoustic emission analysis as a non-destructive test procedure for fiber compound structures

NASA Technical Reports Server (NTRS)

Block, J.

1983-01-01

The concept of acoustic emission analysis is explained in scientific terms. The detection of acoustic events, their localization, damage discrimination, and event summation curves are discussed. A block diagram of the concept of damage-free testing of fiber-reinforced synthetic materials is depicted. Prospects for application of the concept are assessed.

Post-Copenhagen: the 'new' math, legal 'additionality' and climate warming

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

Ferrey, Steven

Control of carbon emissions to the atmosphere is the environmental issue of this decade - perhaps of this entire generation. Its importance has been equated to the survival of the planet. It may all come down to the novel legal concept that sounds like second-grade math: ''additionality.'' However, it is the ''new'' math. (author)

The Extended Concept Of Symmetropy And Its Application To Earthquakes And Acoustic Emissions

NASA Astrophysics Data System (ADS)

Nanjo, K.; Yodogawa, E.

2003-12-01

There is the notion of symmetropy that can be considered as a powerful tool to measure quantitatively entropic heterogeneity regarding symmetry of a pattern. It can be regarded as a quantitative measure to extract the feature of asymmetry of a pattern (Yodogawa, 1982; Nanjo et al., 2000, 2001, 2002 in press). In previous studies, symmetropy was estimated for the spatial distributions of acoustic emissions generated before the ultimate whole fracture of a rock specimen in the laboratory experiment and for the spatial distributions of earthquakes in the seismic source model with self-organized criticality (SOC). In each of these estimations, the outline of the region in which symmetropy is estimated for a pattern is determined to be equal to that of the rock specimen in which acoustic emissions are generated or that of the SOC seismic source model from which earthquakes emerge. When local seismicities like aftershocks, foreshocks and earthquake swarms in the Earth's crust are considered, it is difficult to determine objectively the outline of the region characterizing these local seismicities without the need of subjectiveness. So, the original concept of symmetropy is not appropriate to be directly applied to such local seismicities and the proper modification of the original one is needed. Here, we introduce the notion of symmetropy for the nonlinear geosciences and extend it for the purpose of the application to local seismicities such as aftershocks, foreshocks and earthquake swarms. We employ the extended concept to the spatial distributions of acoustic emissions generated in a previous laboratory experiment where the failure process in a brittle granite sample can be stabilized by controlling axial stress to maintain a constant rate of acoustic emissions and, as a result, detailed view of fracture nucleation and growth was observed. Moreover, it is applied to the temporal variations of spatial distributions of aftershocks and foreshocks of the main shocks, using natural observable data of earthquakes in and around Japan. Our results show the successful applicability of the extended concept of symmetropy to earthquakes and acoustic emissions. Furthermore, it is pointed out that the concept of symmetropy or the extended one of it might be adapted to any pattern recognition in many fields of science, particularly in the nonlinear geosciences and the sciences of complexity. References: Yodogawa, 1982, Percept. Psychophys., v. 32, p. 230-240; Nanjo et al., 2000, Forma, v. 15, p. 95-101; Nanjo et al., 2001, Forma, v. 16, p. 213-224; Nanjo et al., 2002 in press, Symmetry: Art and Science, v. 2.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (phi) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui Joe; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions.This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio(theta) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66% reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50% of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

Natural gas anodes for aluminium electrolysis in molten fluorides.

PubMed

Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

2016-08-15

Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process.

40 CFR 93.119 - Criteria and procedures: Interim emissions in areas without motor vehicle emissions budgets.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emissions analysis as listed in § 93.127 need not be explicitly considered): (1) All in-place regionally... must include the project with its original design concept and scope, and the ‘Action’ scenario must include the project with its new design concept and scope. [62 FR 43801, Aug. 15, 1997, as amended at 69...

Programmable thermal emissivity structures based on bioinspired self-shape materials

NASA Astrophysics Data System (ADS)

Athanasopoulos, N.; Siakavellas, N. J.

2015-12-01

Programmable thermal emissivity structures based on the bioinspired self-shape anisotropic materials were developed at macro-scale, and further studied theoretically at smaller scale. We study a novel concept, incorporating materials that are capable of transforming their shape via microstructural rearrangements under temperature stimuli, while avoiding the use of exotic shape memory materials or complex micro-mechanisms. Thus, programmed thermal emissivity behaviour of a surface is achievable. The self-shape structure reacts according to the temperature of the surrounding environment or the radiative heat flux. A surface which incorporates self-shape structures can be designed to quickly absorb radiative heat energy at low temperature levels, but is simultaneously capable of passively controlling its maximum temperature in order to prevent overheating. It resembles a “game” of colours, where two or more materials coexist with different values of thermal emissivity/ absorptivity/ reflectivity. The transformation of the structure conceals or reveals one of the materials, creating a surface with programmable - and therefore, variable- effective thermal emissivity. Variable thermal emissivity surfaces may be developed with a total hemispherical emissivity ratio (ɛEff_H/ɛEff_L) equal to 28.

Programmable thermal emissivity structures based on bioinspired self-shape materials

PubMed Central

Athanasopoulos, N.; Siakavellas, N. J.

2015-01-01

Programmable thermal emissivity structures based on the bioinspired self-shape anisotropic materials were developed at macro-scale, and further studied theoretically at smaller scale. We study a novel concept, incorporating materials that are capable of transforming their shape via microstructural rearrangements under temperature stimuli, while avoiding the use of exotic shape memory materials or complex micro-mechanisms. Thus, programmed thermal emissivity behaviour of a surface is achievable. The self-shape structure reacts according to the temperature of the surrounding environment or the radiative heat flux. A surface which incorporates self-shape structures can be designed to quickly absorb radiative heat energy at low temperature levels, but is simultaneously capable of passively controlling its maximum temperature in order to prevent overheating. It resembles a “game” of colours, where two or more materials coexist with different values of thermal emissivity/ absorptivity/ reflectivity. The transformation of the structure conceals or reveals one of the materials, creating a surface with programmable – and therefore, variable- effective thermal emissivity. Variable thermal emissivity surfaces may be developed with a total hemispherical emissivity ratio (εEff_H/εEff_L) equal to 28. PMID:26635316

Augmentor emissions reduction technology program. [for turbofan engines

NASA Technical Reports Server (NTRS)

Colley, W. C.; Kenworthy, M. J.; Bahr, D. W.

1977-01-01

Technology to reduce pollutant emissions from duct-burner-type augmentors for use on advanced supersonic cruise aircraft was investigated. Test configurations, representing variations of two duct-burner design concepts, were tested in a rectangular sector rig at inlet temperature and pressure conditions corresponding to takeoff, transonic climb, and supersonic cruise flight conditions. Both design concepts used piloted flameholders to stabilize combustion of lean, premixed fuel/air mixtures. The concepts differed in the flameholder type used. High combustion efficiency (97%) and low levels of emissions (1.19 g/kg fuel) were achieved. The detailed measurements suggested the direction that future development efforts should take to obtain further reductions in emission levels and associated improvements in combustion efficiency over an increased range of temperature rise conditions.

Rapid mix concepts for low emission combustors in gas turbine engines

NASA Technical Reports Server (NTRS)

Talpallikar, Milind V.; Smith, Clifford E.; Lai, Ming-Chia

1990-01-01

NASA LeRC has identified the Rich burn/Quick mix/Lean burn (RQL) combustor as a potential gas turbine combustor concept to reduce NOx emissions in High Speed Civil Transport (HSCT) aircraft. To demonstrate reduced NOx levels, NASA LeRC soon will test a flametube version of an RQL combustor. The critical technology needed for the RQL combustor is a method of quickly mixing combustion air with rich burn gases. Two concepts were proposed to enhance jet mixing in a circular cross-section: the Asymmetric Jet Penetration (AJP) concept; and the Lobed Mixer (LM) concept. In Phase 1, two preliminary configurations of the AJP concept were compared with a conventional 12-jet radial-inflow slot design. The configurations were screened using an advanced 3-D Computational Fluid Dynamics (CFD) code named REFLEQS. Both non-reacting and reacting analyses were performed. For an objective comparison, the conventional design was optimized by parametric variation of the jet-to-mainstream momentum flux (J) ratio. The optimum J was then employed in the AJP simulations. Results showed that the three-jet AJP configuration was superior in overall mixedness compared to the conventional design. However, in regards to NOx emissions, the AJP configuration was inferior. The higher emission level for AJP was caused by a single hot spot located in the wake of the central jet as it entered the combustor. Ways of maintaining good mixedness while eliminating the hot spot were identified for Phase 2 study. Overall, Phase 1 showed the viability of using CFD analyses to evaluate quick-mix concepts. A high probability exists that advancing mixing concepts will reduce NOx emissions in RQL combustors, and should be explored in Phase 2, by parallel numerical and experimental work.

Michigan`s air emission trading program

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

Russette, T.M.; VanKolken, A.M.

1997-12-31

Michigan`s Emission Trading Program took effect on March 16, 1996 after two years of rule development by the Michigan Department of Environmental Quality, Air Quality Division and affected stakeholders. This program is based on the open market trading model and has been designed to (1) be consistent with existing federal and state rules and regulations, (2) integrate with existing air programs such as the permit program, and (3) address the needs of Michigan`s regulated community. Michigan`s Air Quality Division, along with other interested parties, initiated this program as part of market-based approaches to improve air quality through the reduction ofmore » criteria pollutants (except ozone) and volatile organic compounds. The Emission Trading rules offer potential benefits for Michigan companies that include increased operational flexibility, lower compliance costs, and/or money generated from the sale of the emission reduction credits. The environment also benefits from this program because the rules require that 10 percent of all registered emission reductions must be permanently retired as an air quality benefit. The emission trading program provides new opportunities for consulting firms to assist companies by identifying acceptable ways to generate and use emission reduction credits. Air pollution control companies may also see new opportunities by designing and installing control equipment in order to reduce air emissions. The role of consultants and equipment companies may expand to that of a broker selling and/or buying emission reduction credits on the Emission Trading Registry. Much has been learned since the conception of the air emission trading program. This paper will discuss how the program works in practice compared to what was envisioned in theory and the potential benefits from Michigan`s Emission Trading Program.« less

Low NO(x) potential of gas turbine engines

NASA Technical Reports Server (NTRS)

Tacina, Robert R.

1990-01-01

The purpose is to correlate emission levels of gas turbine engines. The predictions of NO(x) emissions are based on a review of the literature of previous low NO(x) combustor programs and analytical chemical kinetic calculations. Concepts included in the literature review consisted of lean-premixed-prevaporized (LPP), rich burn/quick quench/lean burn (RQL), and direct injection. The NO(x) emissions were found to be an exponential function of adiabatic combustion temperature over a wide range of inlet temperatures, pressures and (lean) fuel-air ratios. A simple correlation of NO(x) formation with time was not found. The LPP and direct injection (using gaseous fuels) concepts have the lowest NO(x) emissions of the three concepts. The RQL data has higher values of NO(x) than the LPP concept, probably due to the stoichiometric temperatures and NO(x) production that occur during the quench step. Improvements in the quick quench step could reduce the NO(x) emissions to the LPP levels. The low NO(x) potential of LPP is offset by the operational disadvantages of its narrow stability limits and its susceptibility to autoignition/flashback. The Rich-Burn/Quick-Quench/Lean-Burn (RQL) and the direct injection concepts have the advantage of wider stability limits comparable to conventional combustors.

Analytical screening of low emissions, high performance duct burners for supersonic cruise aircraft engines

NASA Technical Reports Server (NTRS)

Lohmann, R. A.; Riecke, G. T.

1977-01-01

An analytical screening study was conducted to identify duct burner concepts capable of providing low emissions and high performance in advanced supersonic engines. Duct burner configurations ranging from current augmenter technology to advanced concepts such as premix-prevaporized burners were defined. Aerothermal and mechanical design studies provided the basis for screening these configurations using the criteria of emissions, performance, engine compatibility, cost, weight and relative risk. Technology levels derived from recently defined experimental low emissions main burners are required to achieve both low emissions and high performance goals. A configuration based on the Vorbix (Vortex burning and mixing) combustor concept was analytically determined to meet the performance goals and is consistent with the fan duct envelope of a variable cycle engine. The duct burner configuration has a moderate risk level compatible with the schedule of anticipated experimental programs.

Aerodynamically-Actuated Radical Shape-Change Concept

NASA Technical Reports Server (NTRS)

Ivanco, Thomas G.; Ivanco, Marie L.; Ancel, Ersin; Grubb, Amanda L.; Prasad, Supranamaaya

2017-01-01

Aerodynamically-actuated radical shape change (AARSC) is a novel concept that enables flight vehicles to conduct a mission profile containing radically different flight regimes while possibly mitigating the typical penalties incurred by radical geometric change. Weight penalties are mitigated by utilizing a primary flight control to generate aerodynamic loads that then drive a shape-change actuation. The flight mission profile used to analyze the AARSC concept is that of a transport aircraft that cruises at a lower altitude than typical transports. Based upon a preliminary analysis, substantial fuel savings are realized for mission ranges below 2000 NM by comparison to a state-of-the-art baseline, with an increasing impact as mission range is reduced. The predicted savings are so significant at short-haul ranges that the shape-change concept rivals the fuel-burn performance of turboprop aircraft while completing missions in less time than typical jet aircraft. Lower-altitude cruise has also been sought after in recent years for environmental benefits, however, the performance penalty to conventional aircraft was prohibitive. AARSC may enable the opportunity to realize the environmental benefits of lower-altitude emissions coupled with mission fuel savings. The findings of this study also reveal that the AARSC concept appears to be controllable, turbulence susceptibility is likely not an issue, and the shape change concept appears to be mechanically and aerodynamically feasible.

RQL Fuel Shifting Sector Rig Test

NASA Technical Reports Server (NTRS)

Holdeman, James D. (Technical Monitor); Haid, Daniel A.; Koopman, Frederick S.; Peschke, William O. T.; Siskind, Kenneth S.

2004-01-01

The low emissions potential of a Rich-Quench-Lean (RQL) combustor for use in the HIgh Speed Civil transport (HSCT) application was evaluated as part of the NASA Critical Propulsion Components (CPC) Program. Fuel shifting as an approach to combustor control was evaluated in a multiple bank RQL combustor, utilizing reduced scale quench technology implemented in a convoluted linear with quench plate concept.

Control of the low-load region in partially premixed combustion

NASA Astrophysics Data System (ADS)

Ingesson, Gabriel; Yin, Lianhao; Johansson, Rolf; Tunestal, Per

2016-09-01

Partially premixed combustion (PPC) is a low temperature, direct-injection combustion concept that has shown to give promising emission levels and efficiencies over a wide operating range. In this concept, high EGR ratios, high octane-number fuels and early injection timings are used to slow down the auto-ignition reactions and to enhance the fuel and are mixing before the start of combustion. A drawback with this concept is the combustion stability in the low-load region where a high octane-number fuel might cause misfire and low combustion efficiency. This paper investigates the problem of low-load PPC controller design for increased engine efficiency. First, low-load PPC data, obtained from a multi-cylinder heavy- duty engine is presented. The data shows that combustion efficiency could be increased by using a pilot injection and that there is a non-linearity in the relation between injection and combustion timing. Furthermore, intake conditions should be set in order to avoid operating points with unfavourable global equivalence ratio and in-cylinder temperature combinations. Model predictive control simulations were used together with a calibrated engine model to find a gas-system controller that fulfilled this task. The findings are then summarized in a suggested engine controller design. Finally, an experimental performance evaluation of the suggested controller is presented.

Test Rig for Active Turbine Blade Tip Clearance Control Concepts: An Update

NASA Technical Reports Server (NTRS)

Taylor, Shawn; Steinetz, Bruce; Oswald, Jay; DeCastro, Jonathan; Melcher, Kevin

2006-01-01

The objective is to develop and demonstrate a fast-acting active clearance control system to improve turbine engine performance, reduce emissions, and increase service life. System studies have shown the benefits of reducing blade tip clearances in modern turbine engines. Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA's Ultra-Efficient Engine Technology (UEET) turbine engine project goals. NASA GRC is examining two candidate approaches including rub-avoidance and regeneration which are explained in subsequent slides.

Experimental clean combustor program: Diesel no. 2 fuel addendum, phase 3

NASA Technical Reports Server (NTRS)

Gleason, C. C.; Bahr, D. W.

1979-01-01

A CF6-50 engine equipped with an advanced, low emission, double annular combustor was operated 4.8 hours with No. 2 diesel fuel. Fourteen steady-state operating conditions ranging from idle to full power were investigated. Engine/combustor performance and exhaust emissions were obtained and compared to JF-5 fueled test results. With one exception, fuel effects were very small and in agreement with previously obtained combustor test rig results. At high power operating condition, the two fuels produced virtually the same peak metal temperatures and exhaust emission levels. At low power operating conditions, where only the pilot stage was fueled, smoke levels tended to be significantly higher with No. 2 diesel fuel. Additional development of this combustor concept is needed in the areas of exit temperature distribution, engine fuel control, and exhaust emission levels before it can be considered for production engine use.

Low NOx heavy fuel combustor concept program

NASA Technical Reports Server (NTRS)

White, D. J.; Lecren, R. T.; Batakis, A. P.

1981-01-01

A total of twelve low NOx combustor configurations, embodying three different combustion concepts, were designed and fabricated as modular units. These configurations were evaluated experimentally for exhaust emission levels and for mechanical integrity. Emissions data were obtained in depth on two of the configurations.

Aircraft gas turbine low-power emissions reduction technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Gleason, C. C.; Bahr, D. W.

1978-01-01

Advanced aircraft turbine engine combustor technology was used to reduce low-power emissions of carbon monoxide and unburned hydrocarbons to levels significantly lower than those which were achieved with current technology. Three combustor design concepts, which were designated as the hot-wall liner concept, the recuperative-cooled liner concept, and the catalyst converter concept, were evaluated in a series of CF6-50 engine size 40 degree-sector combustor rig tests. Twenty-one configurations were tested at operating conditions spanning the design condition which was an inlet temperature and pressure of 422 K and 304 kPa, a reference velocity of 23 m/s and a fuel-air-ration of 10.5 g/kg. At the design condition typical of aircraft turbine engine ground idle operation, the best configurations of all three concepts met the stringent emission goals which were 10, 1, and 4 g/kg for CO, HC, and Nox, respectively.

Gallium Nitride Nanowires and Heterostructures: Toward Color-Tunable and White-Light Sources.

PubMed

Kuykendall, Tevye R; Schwartzberg, Adam M; Aloni, Shaul

2015-10-14

Gallium-nitride-based light-emitting diodes have enabled the commercialization of efficient solid-state lighting devices. Nonplanar nanomaterial architectures, such as nanowires and nanowire-based heterostructures, have the potential to significantly improve the performance of light-emitting devices through defect reduction, strain relaxation, and increased junction area. In addition, relaxation of internal strain caused by indium incorporation will facilitate pushing the emission wavelength into the red. This could eliminate inefficient phosphor conversion and enable color-tunable emission or white-light emission by combining blue, green, and red sources. Utilizing the waveguiding modes of the individual nanowires will further enhance light emission, and the properties of photonic structures formed by nanowire arrays can be implemented to improve light extraction. Recent advances in synthetic methods leading to better control over GaN and InGaN nanowire synthesis are described along with new concept devices leading to efficient white-light emission. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fundamentals of Coherent Synchrotron Radiation in Storage Rings

NASA Astrophysics Data System (ADS)

Sannibale, F.; Byrd, J. M.; Loftsdottir, A.; Martin, M. C.; Venturini, M.

2004-05-01

We present the fundamental concepts for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The analysis includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use these concepts to optimize the performance of a source for CSR emission.

NASA's Aeronautics Vision

NASA Technical Reports Server (NTRS)

Tenney, Darrel R.

2004-01-01

Six long-term technology focus areas are: 1. Environmentally Friendly, Clean Burning Engines. Focus: Develop innovative technologies to enable intelligent turbine engines that significantly reduce harmful emissions while maintaining high performance and increasing reliability. 2. New Aircraft Energy Sources and Management. Focus: Discover new energy sources and intelligent management techniques directed towards zero emissions and enable new vehicle concepts for public mobility and new science missions. 3. Quiet Aircraft for Community Friendly Service. Focus: Develop and integrate noise reduction technology to enable unrestricted air transportation service to all communities. 4. Aerodynamic Performance for Fuel Efficiency. Focus: Improve aerodynamic efficiency,structures and materials technologies, and design tools and methodologies to reduce fuel burn and minimize environmental impact and enable new vehicle concepts and capabilities for public mobility and new science missions. 5. Aircraft Weight Reduction and Community Access. Focus: Develop ultralight smart materials and structures, aerodynamic concepts, and lightweight subsystems to increase vehicle efficiency, leading to high altitude long endurance vehicles, planetary aircraft, advanced vertical and short takeoff and landing vehicles and beyond. 6. Smart Aircraft and Autonomous Control. Focus: Enable aircraft to fly with reduced or no human intervention, to optimize flight over multiple regimes, and to provide maintenance on demand towards the goal of a feeling, seeing, sensing, sentient air vehicle.

Emission Characteristics of A P and W Axially Staged Sector Combustor

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Wey, Changlie; Chang, Clarence T.; Lee, Chi Ming; Surgenor, Angela D.; Kopp-Vaughan, Kristin; Cheung, Albert

2016-01-01

Emission characteristics of a three-cup P and W Axially Controlled Stoichiometry (ACS) sector combustor are reported in this article. Multiple injection points and fuel staging strategies are used in this combustor design. Pilot-stage injectors are located on the front dome plate of the combustor, and main-stage injectors are positioned on the top and bottom of the combustor liners downstream. Low power configuration uses only pilot-stage injectors. Main-stage injectors are added to high power configuration to help distribute fuel more evenly and achieve overall lean burn yielding very low NOx emissions. Combustion efficiencies at four ICAO LTO conditions were all above 99%. Three EINOx emissions correlation equations were developed based on the experimental data to describe the NOx emission trends of this combustor concept. For the 7% and 30% engine power conditions, NOx emissions are obtained with the low power configuration, and the EINOx values are 6.16 and 6.81. The high power configuration was used to assess 85% and 100% engine power NOx emissions, with measured EINOx values of 4.58 and 7.45, respectively. The overall landing-takeoff cycle NOx emissions are about 12% relative to ICAO CAEP/6 level.

Vertical pillar nanoantenna for emission enhancement and redirection

NASA Astrophysics Data System (ADS)

Paparone, J.; Laverdant, J.; Brucoli, G.; Symonds, C.; Crut, A.; Del Fatti, N.; Benoit, J. M.; Bellessa, J.

2018-01-01

Designing efficient metallic nanostructures can help in realizing bright single photon emission in the visible and near-infrared ranges. We propose a novel nanostructure design that combines the benefits of plasmonic hot spot generation in the near-field and the concept of antennas developed in the radio-frequency range. The antenna is formed by a vertical stack of metallic and dielectric nanocylinders. When used for controlling the far-field emission of a localized source, its key features are moderate losses in the metal, relatively large Purcell factors, as well as a low sensibility to the lateral position of the emitter. A redirection process necessary for these vertical structures is proposed, based on the versatility of the vertical geometry, and allows an efficient redirection of the emitted light even for antennas on dielectric substrates.

Development of marijuana and tobacco detectors using potassium-40 gamma-ray emissions

NASA Astrophysics Data System (ADS)

Kirby, John A.; Lindquist, Roy P.

1994-10-01

Measurements were made at the Otay Mesa, CA, border crossing between November 30 and December 4, 1992, to demonstrate proof of concept and the practicality of using potassium 40 (K40) gamma emissions to detect the presence of marijuana in vehicles. Lawrence Livermore National Laboratory personnel, with the assistance of the EPA, set up three large volume gamma ray detectors with lead brick shielding and collimation under a stationary trailer and pickup truck. Measurements were performed for various positions and quantities of marijuana. Also, small quantities of marijuana, cigarettes, and other materials were subjected to gamma counting measurements under controlled geometry conditions to determine their K40 concentration. Larger quantities of heroin and cocaine were subjected to undefined geometry gamma counts for significant K40 gamma emissions.

Factors controlling dimethylsulfide emission from salt marshes

NASA Technical Reports Server (NTRS)

Dacey, John W. H.; Wakeham, S. G.; Howes, B. L.

1985-01-01

The factors that control the emission of methylated gases from salt marshes are being studied. Research focusses on dimethylsulfide (DMS) formation and the mechanism of DMS and CH4 emission to the atmosphere. The approach is to consider the plants as valves regulating the emission of methylated gases to the atmosphere with the goal of developing appropriate methods for emission measurement. In the case of CH4, the sediment is the source and transport to the atmosphere occurs primarily through the internal gas spaces in the plants. The source of DMS appears to be dimethyl sulfoniopropionate (DMSP) which may play a role in osmoregulation in plant tissues. Concentrations of DMSP in leaves are typically several-fold higher than in roots and rhizomes. Even so, the large below ground biomass of this plant means that 2/3 of the DMSP in the ecosystem is below ground on the aerial basis. Upon introduction to sediment water, DMSP rapidly decomposes to DMS and acrylic acid. The solubility of a gas (its equilibrium vapor pressure) is a fundamental aspect of gas exchange kinetics. The first comprehensive study was conducted of DMS solubility in freshwater and seawater. Data suggest that the Setchenow relation holds for H at intermediate salinities collected. These data support the concept that the concentration of DMS in the atmosphere is far from equilibrium with seawater.

Advanced supersonic propulsion study, phase 2. [propulsion system performance, design analysis and technology assessment

NASA Technical Reports Server (NTRS)

Howlett, R. A.

1975-01-01

A continuation of the NASA/P and WA study to evaluate various types of propulsion systems for advanced commercial supersonic transports has resulted in the identification of two very promising engine concepts. They are the Variable Stream Control Engine which provides independent temperature and velocity control for two coannular exhaust streams, and a derivative of this engine, a Variable Cycle Engine that employs a rear flow-inverter valve to vary the bypass ratio of the cycle. Both concepts are based on advanced engine technology and have the potential for significant improvements in jet noise, exhaust emissions and economic characteristics relative to current technology supersonic engines. Extensive research and technology programs are required in several critical areas that are unique to these supersonic Variable Cycle Engines to realize these potential improvements. Parametric cycle and integration studies of conventional and Variable Cycle Engines are reviewed, features of the two most promising engine concepts are described, and critical technology requirements and required programs are summarized.

BELINDA: Broadband Emission Lidar with Narrowband Determination of Absorption. A new concept for measuring water vapor and temperature profiles

NASA Technical Reports Server (NTRS)

Theopold, F. A.; Weitkamp, C.; Michaelis, W.

1992-01-01

We present a new concept for differential absorption lidar measurements of water vapor and temperature profiles. The idea is to use one broadband emission laser and a narrowband filter system for separation of the 'online' and 'offline' return signals. It is shown that BELINDA offers improvements as to laser emission shape and stability requirements, background suppression, and last and most important a significant reduction of the influence of Rayleigh scattering. A suitably designed system based on this concept is presented, capable of measuring water vapor or temperature profiles throughout the planetary boundary layer.

Combustor concepts for aircraft gas turbine low-power emissions reduction

NASA Technical Reports Server (NTRS)

Mularz, E. J.; Gleason, C. C.; Dodds, W. J.

1978-01-01

Several combustor concepts were designed and tested to demonstrate significant reductions in aircraft engine idle pollutant emissions. Each concept used a different approach for pollutant reductions: the hot wall combustor employs a thermal barrier coating and impingement cooled liners; the recuperative cooling combustor preheats the air before entering the combustion chamber; and the catalytic converter combustor is composed of a conventional primary zone followed by a catalytic bed for pollutant cleanup. The designs are discussed in detail and test results are presented for a range of aircraft engine idle conditions. The results indicate that ultralow levels of unburned hydrocarbons and carbon monoxide emissions can be achieved.

Carbon Emission Flow in Networks

PubMed Central

Kang, Chongqing; Zhou, Tianrui; Chen, Qixin; Xu, Qianyao; Xia, Qing; Ji, Zhen

2012-01-01

As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention. The link between energy production and consumption has required the large-scale transport of energy within energy transmission networks. Within this energy flow, there is a virtual circulation of carbon emissions. To understand this circulation and account for the relationship between energy consumption and carbon emissions, this paper introduces the concept of “carbon emission flow in networks” and establishes a method to calculate carbon emission flow in networks. Using an actual analysis of China's energy pattern, the authors discuss the significance of this new concept, not only as a feasible approach but also as an innovative theoretical perspective. PMID:22761988

Pollution reduction technology program for turboprop engines

NASA Technical Reports Server (NTRS)

Tomlinson, J. G.

1977-01-01

The reduction of CO, HC, and smoke emissions while maintaining acceptable NO(x) emissions without affecting fuel consumption, durability, maintainability, and safety was accomplished. Component combustor concept screening directed toward the demonstration of advanced combustor technology required to meet the EPA exhaust emissions standards for class P2 turboprop engines was covered. The combustion system for the Allison 501-D22A engine was used, and three combustor design concepts - reverse flow, prechamber, and staged fuel were evaluated.

Comparing the greenhouse gas emissions from three alternative waste combustion concepts.

PubMed

Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

2012-03-01

Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO(2)-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved. Copyright © 2011 Elsevier Ltd. All rights reserved.

Experimental clean combustor program, phase 2

NASA Technical Reports Server (NTRS)

Roberts, R.; Peduzzi, A.; Vitti, G. E.

1976-01-01

The alternate fuels investigation objective was to experimentally determine the impacts, if any, on exhaust emissions, performance, and durability characteristics of the hybrid and vorbix low pollution combustor concepts when operated on test fuels which simulate composition and property changes which might result from future broadened aviation turbine fuel specifications or use of synthetically derived crude feedstocks. Results of the program indicate a significant increase in CO and small NOX increase in emissions at idle for both combustor concepts, and an increase in THC for the vorbix concept. Minimal impact was observed on gaseous emissions at high power. The vorbix concept exhibited significant increase in exhaust smoke with increasing fuel aromatic content. Altitude stability was not affected for the vorbix combustor, but was substantially reduced for the hybrid concept. Severe carbon deposition was observed in both combustors following limited endurance testing with No. 2 home heat fuel. Liner temperature levels were insensitive to variations in aromatic content over the range of conditions investigated.

Progress in Emission Efficiency of Organic Light-Emitting Diodes: Basic Understanding and Its Technical Application

NASA Astrophysics Data System (ADS)

Tsutsui, Tetsuo; Takada, Noriyuki

2013-11-01

The technical history of when and how the basic understanding of the emission efficiency of organic light-emitting diodes (OLEDs) was established over the last 50 years is described. At first, our understanding of emission efficiency in single-crystal and thin-film electroluminescence (EL) devices in the early stages before the Eastman-Kodak breakthrough, that is, the introduction of the concept of multilayer structures, is examined. Then our contemplation travels from the Eastman-Kodak breakthrough towards the presently widely accepted concept of emission efficiency. The essential issues concerning the emission efficiency of OLEDs are summarized to help readers to obtain a common understanding of OLED efficiency problems, and detailed discussions on the primary factors that determine emission efficiency are given. Finally, some comments on remaining issues are presented.

In-situ acoustic signature monitoring in additive manufacturing processes

NASA Astrophysics Data System (ADS)

Koester, Lucas W.; Taheri, Hossein; Bigelow, Timothy A.; Bond, Leonard J.; Faierson, Eric J.

2018-04-01

Additive manufacturing is a rapidly maturing process for the production of complex metallic, ceramic, polymeric, and composite components. The processes used are numerous, and with the complex geometries involved this can make quality control and standardization of the process and inspection difficult. Acoustic emission measurements have been used previously to monitor a number of processes including machining and welding. The authors have identified acoustic signature measurement as a potential means of monitoring metal additive manufacturing processes using process noise characteristics and those discrete acoustic emission events characteristic of defect growth, including cracks and delamination. Results of acoustic monitoring for a metal additive manufacturing process (directed energy deposition) are reported. The work investigated correlations between acoustic emissions and process noise with variations in machine state and deposition parameters, and provided proof of concept data that such correlations do exist.

NASA Puffin Electric Tailsitter VTOL Concept

NASA Technical Reports Server (NTRS)

Moore, Mark D.

2010-01-01

Electric propulsion offers dramatic new vehicle mission capabilities, not possible with turbine or reciprocating engines; including high reliability and efficiency, low engine weight and maintenance, low cooling drag and volume required, very low noise and vibration, and zero emissions. The only penalizing characteristic of electric propulsion is the current energy storage technology level, which is set to triple over the next 5-10 years through huge new investments in this field. Most importantly, electric propulsion offers incredible new degrees of freedom in aircraft system integration to achieve unprecedented levels of aerodynamic, propulsive, control, and structural synergistic coupling. A unique characteristic of electric propulsion is that the technology is nearly scale-free, permitting small motors to be parallelized for fail-safe redundancy, or distributed across the airframe for tightly coupled interdisciplinary functionality without significant impacts in motor-controller efficiency or specific weight. Maximizing the potential benefit of electric propulsion is dependent on applying this technology to synergistic mission concepts. The vehicle missions with the most benefit include those which constrain environmental impact (or limit noise, exhaust, or emission signatures) are short range, or where large differences exist in the propulsion system sizing between takeoff and cruise conditions. Electric propulsion offers the following unique capabilities that other propulsion systems can t provide for short range Vertical Takeoff and Landing (VTOL) aircraft; elimination of engine noise and emissions, drastic reduction in engine cooling and radiated heat, drastic reduction in vehicle vibration levels, drastic improvement in reliability and operating costs, variable speed output at full power, for improved cruise efficiency at low tip-speed, elimination of high/hot sizing penalty, and reduction of engine-out penalties.

DRIVE CYCLE EFFICIENCY AND EMISSIONS ESTIMATES FOR REACTIVITY CONTROLLED COMPRESSION IGNITION IN A MULTI-CYLINDER LIGHT-DUTY DIESEL ENGINE

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

Curran, Scott; Briggs, Thomas E; Cho, Kukwon

2011-01-01

In-cylinder blending of gasoline and diesel to achieve Reactivity Controlled Compression Ignition (RCCI) has been shown to reduce NOx and PM emissions while maintaining or improving brake thermal efficiency as compared to conventional diesel combustion (CDC). The RCCI concept has an advantage over many advanced combustion strategies in that by varying both the percent of premixed gasoline and EGR rate, stable combustion can be extended over more of the light-duty drive cycle load range. Changing the percent premixed gasoline changes the fuel reactivity stratification in the cylinder providing further control of combustion phasing and pressure rise rate than the usemore » of EGR alone. This paper examines the combustion and emissions performance of light-duty diesel engine using direct injected diesel fuel and port injected gasoline to carry out RCCI for steady-state engine conditions which are consistent with a light-duty drive cycle. A GM 1.9L four-cylinder engine with the stock compression ratio of 17.5:1, common rail diesel injection system, high-pressure EGR system and variable geometry turbocharger was modified to allow for port fuel injection with gasoline. Engine-out emissions, engine performance and combustion behavior for RCCI operation is compared against both CDC and a premixed charge compression ignition (PCCI) strategy which relies on high levels of EGR dilution. The effect of percent of premixed gasoline, EGR rate, boost level, intake mixture temperature, combustion phasing and pressure rise rate is investigated for RCCI combustion for the light-duty modal points. Engine-out emissions of NOx and PM were found to be considerably lower for RCCI operation as compared to CDC and PCCI, while HC and CO emissions were higher. Brake thermal efficiency was similar or higher for many of the modal conditions for RCCI operation. The emissions results are used to estimate hot-start FTP-75 emissions levels with RCCI and are compared against CDC and PCCI modes.« less

A Comparison of Three Second-generation Swirl-Venturi Lean Direct Injection Combustor Concepts

NASA Technical Reports Server (NTRS)

Tacina, Kathleen M.; Podboy, Derek P.; He, Zhuohui Joe; Lee, Phil; Dam, Bidhan; Mongia, Hukam

2016-01-01

Three variations of a low emissions aircraft gas turbine engine combustion concept were developed and tested. The concept is a second generation swirl-venturi lean direct injection (SV-LDI) concept. LDI is a lean-burn combustion concept in which the fuel is injected directly into the flame zone. All three variations were based on the baseline 9- point SV-LDI configuration reported previously. The three second generation SV-LDI variations are called the 5-recess configuration, the flat dome configuration, and the 9- recess configuration. These three configurations were tested in a NASA Glenn Research Center medium pressure flametube. All three second generation variations had better low power operability than the baseline 9-point configuration. All three configurations had low NO(sub x) emissions, with the 5-recess configuration generally having slightly lower NO(x) than the flat dome or 9-recess configurations. Due to the limitations of the flametube that prevented testing at pressures above 20 atm, correlation equations were developed for the at dome and 9-recess configurations so that the landing-takeoff NO(sub x) emissions could be estimated. The flat dome and 9-recess landing-takeoff NO(x) emissions are estimated to be 81-88% below the CAEP/6 standards, exceeding the project goal of 75% reduction.

A Simulation Model of Carbon Cycling and Methane Emissions in Amazon Wetlands

NASA Technical Reports Server (NTRS)

Potter, Christopher; Melack, John; Hess, Laura; Forsberg, Bruce; Novo, Evlyn Moraes; Klooster, Steven

2004-01-01

An integrative carbon study is investigating the hypothesis that measured fluxes of methane from wetlands in the Amazon region can be predicted accurately using a combination of process modeling of ecosystem carbon cycles and remote sensing of regional floodplain dynamics. A new simulation model has been build using the NASA- CASA concept for predicting methane production and emission fluxes in Amazon river and floodplain ecosystems. Numerous innovations area being made to model Amazon wetland ecosystems, including: (1) prediction of wetland net primary production (NPP) as the source for plant litter decomposition and accumulation of sediment organic matter in two major vegetation classes - flooded forests (varzea or igapo) and floating macrophytes, (2) representation of controls on carbon processing and methane evasion at the diffusive boundary layer, through the lake water column, and in wetland sediments as a function of changes in floodplain water level, (3) inclusion of surface emissions controls on wetland methane fluxes, including variations in daily surface temperature and of hydrostatic pressure linked to water level fluctuations. A model design overview and early simulation results are presented.

Acoustic emission linear pulse holography

DOEpatents

Collins, H.D.; Busse, L.J.; Lemon, D.K.

1983-10-25

This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

Development of optical MEMS CO2 sensors

NASA Astrophysics Data System (ADS)

McNeal, Mark P.; Moelders, Nicholas; Pralle, Martin U.; Puscasu, Irina; Last, Lisa; Ho, William; Greenwald, Anton C.; Daly, James T.; Johnson, Edward A.; George, Thomas

2002-09-01

Inexpensive optical MEMS gas and chemical sensors offer chip-level solutions to environmental monitoring, industrial health and safety, indoor air quality, and automobile exhaust emissions monitoring. Previously, Ion Optics, Inc. reported on a new design concept exploiting Si-based suspended micro-bridge structures. The devices are fabricated using conventional CMOS compatible processes. The use of photonic bandgap (PBG) crystals enables narrow band IR emission for high chemical selectivity and sensitivity. Spectral tuning was accomplished by controlling symmetry and lattice spacing of the PBG structures. IR spectroscopic studies were used to characterize transmission, absorption and emission spectra in the 2 to 20 micrometers wavelength range. Prototype designs explored suspension architectures and filament geometries. Device characterization studies measured drive and emission power, temperature uniformity, and black body detectivity. Gas detection was achieved using non-dispersive infrared (NDIR) spectroscopic techniques, whereby target gas species were determined from comparison to referenced spectra. A sensor system employing the emitter/detector sensor-chip with gas cell and reflective optics is demonstrated and CO2 gas sensitivity limits are reported.

Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system

NASA Astrophysics Data System (ADS)

Massina, Christopher James

The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity radiator architecture is considered to be at a technology readiness level of 3/4, indicating that analytical proof-of-concept and component level validation in a laboratory environment have been completed. While this is not a numeric increase from previous investigations, these contributions are a significant iteration within those levels. These results improve the understanding of the capabilities provided by the full suit, variable emissivity architecture.

A unifying conceptual model for the environmental responses of isoprene emissions from plants.

PubMed

Morfopoulos, Catherine; Prentice, Iain C; Keenan, Trevor F; Friedlingstein, Pierre; Medlyn, Belinda E; Peñuelas, Josep; Possell, Malcolm

2013-11-01

Isoprene is the most important volatile organic compound emitted by land plants in terms of abundance and environmental effects. Controls on isoprene emission rates include light, temperature, water supply and CO2 concentration. A need to quantify these controls has long been recognized. There are already models that give realistic results, but they are complex, highly empirical and require separate responses to different drivers. This study sets out to find a simpler, unifying principle. A simple model is presented based on the idea of balancing demands for reducing power (derived from photosynthetic electron transport) in primary metabolism versus the secondary pathway that leads to the synthesis of isoprene. This model's ability to account for key features in a variety of experimental data sets is assessed. The model simultaneously predicts the fundamental responses observed in short-term experiments, namely: (1) the decoupling between carbon assimilation and isoprene emission; (2) a continued increase in isoprene emission with photosynthetically active radiation (PAR) at high PAR, after carbon assimilation has saturated; (3) a maximum of isoprene emission at low internal CO2 concentration (ci) and an asymptotic decline thereafter with increasing ci; (4) maintenance of high isoprene emissions when carbon assimilation is restricted by drought; and (5) a temperature optimum higher than that of photosynthesis, but lower than that of isoprene synthase activity. A simple model was used to test the hypothesis that reducing power available to the synthesis pathway for isoprene varies according to the extent to which the needs of carbon assimilation are satisfied. Despite its simplicity the model explains much in terms of the observed response of isoprene to external drivers as well as the observed decoupling between carbon assimilation and isoprene emission. The concept has the potential to improve global-scale modelling of vegetation isoprene emission.

Dynamic Modeling, Controls, and Testing for Electrified Aircraft

NASA Technical Reports Server (NTRS)

Connolly, Joseph; Stalcup, Erik

2017-01-01

Electrified aircraft have the potential to provide significant benefits for efficiency and emissions reductions. To assess these potential benefits, modeling tools are needed to provide rapid evaluation of diverse concepts and to ensure safe operability and peak performance over the mission. The modeling challenge for these vehicles is the ability to show significant benefits over the current highly refined aircraft systems. The STARC-ABL (single-aisle turbo-electric aircraft with an aft boundary layer propulsor) is a new test proposal that builds upon previous N3-X team hybrid designs. This presentation describes the STARC-ABL concept, the NASA Electric Aircraft Testbed (NEAT) which will allow testing of the STARC-ABL powertrain, and the related modeling and simulation efforts to date. Modeling and simulation includes a turbofan simulation, Numeric Propulsion System Simulation (NPSS), which has been integrated with NEAT; and a power systems and control model for predicting testbed performance and evaluating control schemes. Model predictions provide good comparisons with testbed data for an NPSS-integrated test of the single-string configuration of NEAT.

High-fidelity Simulation of Jet Noise from Rectangular Nozzles . [Large Eddy Simulation (LES) Model for Noise Reduction in Advanced Jet Engines and Automobiles

NASA Technical Reports Server (NTRS)

Sinha, Neeraj

2014-01-01

This Phase II project validated a state-of-the-art LES model, coupled with a Ffowcs Williams-Hawkings (FW-H) far-field acoustic solver, to support the development of advanced engine concepts. These concepts include innovative flow control strategies to attenuate jet noise emissions. The end-to-end LES/ FW-H noise prediction model was demonstrated and validated by applying it to rectangular nozzle designs with a high aspect ratio. The model also was validated against acoustic and flow-field data from a realistic jet-pylon experiment, thereby significantly advancing the state of the art for LES.

CARBON EMISSIONS ECONOMIC INTENSITY INDEX (CEEII)

EPA Science Inventory

The core concept of the CEEII is to understand, at the state level, the carbon emissions from energy consumption in relation to the value of the activity that generates the emissions. The CEEII treats carbon emissions as an input to producing the activity’s value and assesses th...

Photoswitchable non-fluorescent thermochromic dye-nanoparticle hybrid probes.

PubMed

Harrington, Walter N; Haji, Mwafaq R; Galanzha, Ekaterina I; Nedosekin, Dmitry A; Nima, Zeid A; Watanabe, Fumiya; Ghosh, Anindya; Biris, Alexandru S; Zharov, Vladimir P

2016-11-08

Photoswitchable fluorescent proteins with controllable light-dark states and spectral shifts in emission in response to light have led to breakthroughs in the study of cell biology. Nevertheless, conventional photoswitching is not applicable for weakly fluorescent proteins and requires UV light with low depth penetration in bio-tissue. Here we introduce a novel concept of photoswitchable hybrid probes consisting of thermochromic dye and absorbing nanoparticles, in which temperature-sensitive light-dark states and spectral shifts in absorption can be switched through controllable photothermal heating of doped nanoparticles. The proof-of-concept is demonstrated through the use of two different types of temperature-sensitive dyes doped with magnetic nanoparticles and reversibly photoswitched by a near-infrared laser. Photoacoustic imaging revealed the high contrast of these probes, which is sufficient for their visualization in cells and deep tissue. Our results suggest that these new photoswitchable multicolour probes can be used for multimodal cellular diagnostics and potentially for magnetic and photothermal therapy.

Photoswitchable non-fluorescent thermochromic dye-nanoparticle hybrid probes

NASA Astrophysics Data System (ADS)

Harrington, Walter N.; Haji, Mwafaq R.; Galanzha, Ekaterina I.; Nedosekin, Dmitry A.; Nima, Zeid A.; Watanabe, Fumiya; Ghosh, Anindya; Biris, Alexandru S.; Zharov, Vladimir P.

2016-11-01

Photoswitchable fluorescent proteins with controllable light-dark states and spectral shifts in emission in response to light have led to breakthroughs in the study of cell biology. Nevertheless, conventional photoswitching is not applicable for weakly fluorescent proteins and requires UV light with low depth penetration in bio-tissue. Here we introduce a novel concept of photoswitchable hybrid probes consisting of thermochromic dye and absorbing nanoparticles, in which temperature-sensitive light-dark states and spectral shifts in absorption can be switched through controllable photothermal heating of doped nanoparticles. The proof-of-concept is demonstrated through the use of two different types of temperature-sensitive dyes doped with magnetic nanoparticles and reversibly photoswitched by a near-infrared laser. Photoacoustic imaging revealed the high contrast of these probes, which is sufficient for their visualization in cells and deep tissue. Our results suggest that these new photoswitchable multicolour probes can be used for multimodal cellular diagnostics and potentially for magnetic and photothermal therapy.

Flame Tube NOx Emissions Using a Lean-Direct-Wall-Injection Combustor Concept

NASA Technical Reports Server (NTRS)

Tacina, Robert R.; Wey, Changlie; Choi, Kyung J.

2001-01-01

A low-NOx emissions combustor concept has been demonstrated in flame tube tests. A lean-direct injection concept was used where the fuel is injected directly into the flame zone and the overall fuel-air mixture is lean. In this concept the air is swirled upstream of a venturi section and the fuel is injected radially inward into the air stream from the throat section using a plain-orifice injector. Configurations have two-, four-, or six-wall fuel injectors and in some cases fuel is also injected from an axially located simplex pressure atomizer. Various orifice sizes of the plain-orifice injector were evaluated for the effect on NOx. Test conditions were inlet temperatures up to 8 1 OK, inlet pressures up to 2760 kPa, and flame temperatures up to 2100 K. A correlation is developed relating the NOx emissions to inlet temperature, inlet pressure, fuel-air ratio and pressure drop. Assuming that 15 percent of the combustion air would be used for liner cooling and using an advanced engine cycle, for the best configuration, the NOx emissions using the correlation is estimated to be <75 percent of the 1996 ICAO standard.

Results of the pollution reduction technology program for turboprop engines

NASA Technical Reports Server (NTRS)

Mularz, E. J.

1976-01-01

A program was performed to evolve and demonstrate advanced combustor technology aimed at achieving the 1979 EPA standards for turboprop engines (Class P2). The engine selected for this program was the 501-D22A turboprop. Three combustor concepts were designed and tested in a combustor rig at the exact combustor operating conditions of the 50-D22A engine over the EPA landing-takeoff cycle. Each combustor concept exhibited pollutant emissions well below the EPA standards, achieving substantial reductions in unburned hydrocarbons, carbon monoxide, and smoke emissions compared with emissions from the production combustor of this engine. Oxides of nitrogen emissions remained well below the EPA standards, also.

SunRISE Mission Concept Step 2 Study Status

NASA Astrophysics Data System (ADS)

Alibay, F.; Kasper, J. C.; Lazio, J.; Neilsen, T. L.

2017-12-01

We present an update on the Sun Radio Interferometer Space Experiment (SunRISE) mission concept, which was selected for a Step 2 study as part of the Small Explorer (SMEX) Mission of Opportunity (MoO) call. SunRISE is space-based sparse array, composed of six 6U CubeSats, designed to localize the radio emission associated with coronal mass ejections (CMEs) from the Sun. Radio emission from CMEs is a direct tracer of the particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Furthermore, CME radio emission is quite strong such that only a relatively small number of antennas is required, and a small mission would make a fundamental advancement. Indeed, the state-of-the-art for tracking CME radio emission is defined by single antennas (Wind/WAVES, Stereo/SWAVES) in which the tracking is accomplished by assuming a frequency-to-density mapping. This type of Heliophysics mission would be inherently cost prohibitive in a traditional spacecraft paradigm. However, the use of CubeSats, accompanied by the miniaturization of subsystem components, enables the development of this concept at lower cost than ever before. We present the most recent updates on this mission concept, starting from the concept's performance as compared to the required science and driving technical requirements. We then focus on the SunRISE mission concept of operations, which consists of six 6U CubeSats placed in a GEO graveyard orbit for 6 months to achieve the aforementioned science goals. The spacecraft fly in a passive formation, which allows them to form an interferometer while minimizing the impact on operations complexity. We also present details of the engineering design and the key trades being performed as part of the Step 2 concept study.

Small Engine Technology (SET) - Task 4, Regional Turboprop/Turbofan Engine Advanced Combustor Study

NASA Technical Reports Server (NTRS)

Reynolds, Robert; Srinivasan, Ram; Myers, Geoffrey; Cardenas, Manuel; Penko, Paul F. (Technical Monitor)

2003-01-01

Under the SET Program Task 4 - Regional Turboprop/Turbofan Engine Advanced Combustor Study, a total of ten low-emissions combustion system concepts were evaluated analytically for three different gas turbine engine geometries and three different levels of oxides of nitrogen (NOx) reduction technology, using an existing AlliedSignal three-dimensional (3-D) Computational Fluid Dynamics (CFD) code to predict Landing and Takeoff (LTO) engine cycle emission values. A list of potential Barrier Technologies to the successful implementation of these low-NOx combustor designs was created and assessed. A trade study was performed that ranked each of the ten study configurations on the basis of a number of manufacturing and durability factors, in addition to emissions levels. The results of the trade study identified three basic NOx-emissions reduction concepts that could be incorporated in proposed follow-on combustor technology development programs aimed at demonstrating low-NOx combustor hardware. These concepts are: high-flow swirlers and primary orifices, fuel-preparation cans, and double-dome swirlers.

Assessment of the Performance Potential of Advanced Subsonic Transport Concepts for NASA's Environmentally Responsible Aviation Project

NASA Technical Reports Server (NTRS)

Nickol, Craig L.; Haller, William J.

2016-01-01

NASA's Environmentally Responsible Aviation (ERA) project has matured technologies to enable simultaneous reductions in fuel burn, noise, and nitrogen oxide (NOx) emissions for future subsonic commercial transport aircraft. The fuel burn reduction target was a 50% reduction in block fuel burn (relative to a 2005 best-in-class baseline aircraft), utilizing technologies with an estimated Technology Readiness Level (TRL) of 4-6 by 2020. Progress towards this fuel burn reduction target was measured through the conceptual design and analysis of advanced subsonic commercial transport concepts spanning vehicle size classes from regional jet (98 passengers) to very large twin aisle size (400 passengers). Both conventional tube-and-wing (T+W) concepts and unconventional (over-wing-nacelle (OWN), hybrid wing body (HWB), mid-fuselage nacelle (MFN)) concepts were developed. A set of propulsion and airframe technologies were defined and integrated onto these advanced concepts which were then sized to meet the baseline mission requirements. Block fuel burn performance was then estimated, resulting in reductions relative to the 2005 best-in-class baseline performance ranging from 39% to 49%. The advanced single-aisle and large twin aisle T+W concepts had reductions of 43% and 41%, respectively, relative to the 737-800 and 777-200LR aircraft. The single-aisle OWN concept and the large twin aisle class HWB concept had reductions of 45% and 47%, respectively. In addition to their estimated fuel burn reduction performance, these unconventional concepts have the potential to provide significant noise reductions due, in part, to engine shielding provided by the airframe. Finally, all of the advanced concepts also have the potential for significant NOx emissions reductions due to the use of advanced combustor technology. Noise and NOx emissions reduction estimates were also generated for these concepts as part of the ERA project.

Impacts of Lowered Urban Air Temperatures on Precursor Emission and Ozone Air Quality.

PubMed

Taha, Haider; Konopacki, Steven; Akbari, Hashem

1998-09-01

Meteorological, photochemical, building-energy, and power plant simulations were performed to assess the possible precursor emission and ozone air quality impacts of decreased air temperatures that could result from implementing the "cool communities" concept in California's South Coast Air Basin (SoCAB). Two pathways are considered. In the direct pathway, a reduction in cooling energy use translates into reduced demand for generation capacity and, thus, reduced precursor emissions from electric utility power plants. In the indirect pathway, reduced air temperatures can slow the atmospheric production of ozone as well as precursor emission from anthropogenic and biogenic sources. The simulations suggest small impacts on emissions following implementation of cool communities in the SoCAB. In summer, for example, there can be reductions of up to 3% in NO x emissions from in-basin power plants. The photochemical simulations suggest that the air quality impacts of these direct emission reductions are small. However, the indirect atmospheric effects of cool communities can be significant. For example, ozone peak concentrations can decrease by up to 11% in summer and population-weighted exceedance exposure to ozone above the California and National Ambient Air Quality Standards can decrease by up to 11 and 17%, respectively. The modeling suggests that if these strategies are combined with others, such as mobile-source emission control, the improvements in ozone air quality can be substantial.

Thermal Test Verification of Emission Control through Directional Baffles for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Garrison, Matthew; Rashford, Robert; Switzer, Timothy; Shaw, David; White, Bryant; Lynch, Michael; Huber, Frank; Bachtell, Neal

2009-01-01

The thermal performance of NASA s planned James Webb Space Telescope is highly reliant on a collection of directional baffles that are part of the Integrated Science Instrument Module Electronics Compartment. In order to verify the performance of the baffle concept, two test assemblies were recently fabricated and tested at the Goddard Space Flight Center. The centerpiece of the testing was a fixture that used bolometers to measure the emission field through the baffles while the radiator panels and baffles ran a flight-like temperature. Although not all test goals were able to be met due to facility malfunctions, the test was able to prove the design viability enough to gain approval to begin manufacturing the flight article.

Segmented cold cathode display panel

NASA Technical Reports Server (NTRS)

Payne, Leslie (Inventor)

1998-01-01

The present invention is a video display device that utilizes the novel concept of generating an electronically controlled pattern of electron emission at the output of a segmented photocathode. This pattern of electron emission is amplified via a channel plate. The result is that an intense electronic image can be accelerated toward a phosphor thus creating a bright video image. This novel arrangement allows for one to provide a full color flat video display capable of implementation in large formats. In an alternate arrangement, the present invention is provided without the channel plate and a porous conducting surface is provided instead. In this alternate arrangement, the brightness of the image is reduced but the cost of the overall device is significantly lowered because fabrication complexity is significantly decreased.

Reduction of gaseous pollutant emissions from gas turbine combustors using hydrogen-enriched jet fuel

NASA Technical Reports Server (NTRS)

Clayton, R. M.

1976-01-01

Recent progress in an evaluation of the applicability of the hydrogen enrichment concept to achieve ultralow gaseous pollutant emission from gas turbine combustion systems is described. The target emission indexes for the program are 1.0 for oxides of nitrogen and carbon monoxide, and 0.5 for unburned hydrocarbons. The basic concept utilizes premixed molecular hydrogen, conventional jet fuel, and air to depress the lean flammability limit of the mixed fuel. This is shown to permit very lean combustion with its low NOx production while simulataneously providing an increased flame stability margin with which to maintain low CO and HC emission. Experimental emission characteristics and selected analytical results are presented for a cylindrical research combustor designed for operation with inlet-air state conditions typical for a 30:1 compression ratio, high bypass ratio, turbofan commercial engine.

Future development programs. [for emission reduction and production of aircraft engines

NASA Technical Reports Server (NTRS)

Waters, L.

1976-01-01

A company program was planned which has a main drive to develop those emission reduction concepts that have the promise of earliest success. These programs were proposed in an attempt to enhance existing engine systems, exploiting their potential for emission reduction as far as is compatible with retaining the well established features in them that are well understood and in current production. The intended programs identified in the area of new concepts were: (1) upgrading the TCM fuel system, (2) evaluation of accelerator pump, (3) reduced cooling requirement, and (4) variable spark timing.

Spaceborne Microwave Instrument for High Resolution Remote Sensing of the Earth's Surface Using a Large-Aperture Mesh Antenna

NASA Technical Reports Server (NTRS)

Njoku, E.; Wilson, W.; Yueh, S.; Freeland, R.; Helms, R.; Edelstein, W.; Sadowy, G.; Farra, D.; West, R.; Oxnevad, K.

2001-01-01

This report describes a two-year study of a large-aperture, lightweight, deployable mesh antenna system for radiometer and radar remote sensing of the Earth from space. The study focused specifically on an instrument to measure ocean salinity and Soil moisture. Measurements of ocean salinity and soil moisture are of critical . importance in improving knowledge and prediction of key ocean and land surface processes, but are not currently obtainable from space. A mission using this instrument would be the first demonstration of deployable mesh antenna technology for remote sensing and could lead to potential applications in other remote sensing disciplines that require high spatial resolution measurements. The study concept features a rotating 6-m-diameter deployable mesh antenna, with radiometer and radar sensors, to measure microwave emission and backscatter from the Earth's surface. The sensors operate at L and S bands, with multiple polarizations and a constant look angle, scanning across a wide swath. The study included detailed analyses of science requirements, reflector and feedhorn design and performance, microwave emissivity measurements of mesh samples, design and test of lightweight radar electronic., launch vehicle accommodations, rotational dynamics simulations, and an analysis of attitude control issues associated with the antenna and spacecraft, The goal of the study was to advance the technology readiness of the overall concept to a level appropriate for an Earth science emission.

Air toxics evaluation of ABB Combustion Engineering Low-Emission Boiler Systems

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

Wesnor, J.D.

1993-10-26

The specific goals of the program are to identify air toxic compounds that might be emmitted from the new boiler with its various Air Pollution Control device for APCD alternatives in levels of regulatory concern. For the compounds thought to be of concern, potential air toxic control methodologies will be suggested and a Test Protocol will be written to be used in the Proof of Concept and full scale tests. The following task was defined: Define Replations and Standards; Identify Air Toxic Pollutants of Interest to Interest to Utility Boilers; Assesment of Air Toxic By-Products; State of the Art Assessmentmore » of Toxic By-Product Control Technologies; and Test Protocol Definition.« 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

Evaluation of concepts for controlling exhaust emissions from minimally processed petroleum and synthetic fuels

NASA Technical Reports Server (NTRS)

Russell, P. L.; Beal, G. W.; Sederquist, R. A.; Shultz, D.

1981-01-01

Rich-lean combustor concepts designed to enhance rich combustion chemistry and increase combustor flexibility for NO(x) reduction with minimally processed fuels are examined. Processes such as rich product recirculation in the rich chamber, rich-lean annihilation, and graduated air addition or staged rich combustion to release bound nitrogen in steps of reduced equivalence ratio are discussed. Variations to the baseline rapid quench section are considered, and the effect of residence time in the rich zone is investigated. The feasibility of using uncooled non-metallic materials for the rich zone combustion construction is also addressed. The preliminary results indicate that rich primary zone staged combustion provides environmentally acceptable operation with residual and/or synthetic coal-derived liquid fuels

Composite Matrix Cooling Scheme for Small Gas Turbine Combustors

NASA Technical Reports Server (NTRS)

Paskin, Marc D.; Ross, Phillip T.; Mongia, Hukam C.; Acosta, Waldo A.

1990-01-01

The design, manufacture, and testing of a compliant metal/ceramic (CMC) wall cooling concept-implementing combustor for small gas turbine engines has been undertaken by a joint U.S. Army/NASA technology development program. CMC in principle promises greater wall cooling effectiveness than conventional designs and materials, thereby facilitating a substantial reduction in combustor cooling air requirements and furnishing greater airflow for the control of burner outlet temperature patterns as well as improving thermodynamic efficiency and reducing pollutant emissions and smoke levels. Rig test results have confirmed the projected benefits of the CMC concept at combustor outlet temperatures of the order of 2460 F, at which approximately 80 percent less cooling air than conventionally required was being employed by the CMC combustor.

Integrated low emissions cleanup system for direct coal-fueled turbines

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

Lippert, T.E.; Newby, R.A.; Alvin, M.A.

1992-01-01

The Westinghouse Electric Corporation, Science Technology Center (W-STC) is developing an Integrated Low Emissions Cleanup (ILEC) concept for high-temperature gas cleaning to meet environmental standards, as well as to economical gas turbine life. The ILEC concept simultaneously controls sulfur, particulate, and alkali contaminants in high-pressure fuel gases or combustion gases at temperatures up to 1850[degrees]F for advanced power generation systems (PFBC, APFBC, IGCC, DCF7). The objective of this program is to demonstrate, at a bench scale, the conceptual, technical feasibility of the REC concept. The ELEC development program has a 3 phase structure: Phase 1 - laboratory-scale testing; phase 2more » - bench-scale equipment; design and fabrication; and phase 3 - bench-scale testing. Phase 1 laboratory testing has been completed. In Phase 1, entrained sulfur and alkali sorbent kinetics were measured and evaluated, and commercial-scale performance was projected. Related cold flow model testing has shown that gas-particle contacting within the ceramic barrier filter vessel will provide a good reactor environment. The Phase 1 test results and the commercial evaluation conducted in the Phase 1 program support the bench-scale facility testing to be performed in Phase 3. Phase 2 is nearing completion with the design and assembly of a modified, bench-scale test facility to demonstrate the technical feasibility of the ILEC features. This feasibility testing will be conducted in Phase 3.« less

Integrated low emissions cleanup system for direct coal-fueled turbines

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

Lippert, T.E.; Newby, R.A.; Alvin, M.A.

1992-12-31

The Westinghouse Electric Corporation, Science & Technology Center (W-STC) is developing an Integrated Low Emissions Cleanup (ILEC) concept for high-temperature gas cleaning to meet environmental standards, as well as to economical gas turbine life. The ILEC concept simultaneously controls sulfur, particulate, and alkali contaminants in high-pressure fuel gases or combustion gases at temperatures up to 1850{degrees}F for advanced power generation systems (PFBC, APFBC, IGCC, DCF7). The objective of this program is to demonstrate, at a bench scale, the conceptual, technical feasibility of the REC concept. The ELEC development program has a 3 phase structure: Phase 1 - laboratory-scale testing; phasemore » 2 - bench-scale equipment; design and fabrication; and phase 3 - bench-scale testing. Phase 1 laboratory testing has been completed. In Phase 1, entrained sulfur and alkali sorbent kinetics were measured and evaluated, and commercial-scale performance was projected. Related cold flow model testing has shown that gas-particle contacting within the ceramic barrier filter vessel will provide a good reactor environment. The Phase 1 test results and the commercial evaluation conducted in the Phase 1 program support the bench-scale facility testing to be performed in Phase 3. Phase 2 is nearing completion with the design and assembly of a modified, bench-scale test facility to demonstrate the technical feasibility of the ILEC features. This feasibility testing will be conducted in Phase 3.« less

Next Generation Emission Measurements for Fugitive, Area Source, and Fence Line Applications?

EPA Science Inventory

Next generation emissions measurements (NGEM) is an EPA term for the rapidly advancing field of air pollutant sensor technologies, data integration concepts, and associated geospatial modeling strategies for source emissions measurements. Ranging from low coat sensors to satelli...

Operation of the NETL Chemical Looping Reactor with Natural Gas and a Novel Copper-Iron Material

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

Bayham, Sanuel; Straub, Doug; Weber, Justin

2017-02-01

As part of the U.S. Department of Energy’s Advanced Combustion Program, the National Energy Technology Laboratory’s Research and Innovation Center (NETL R&IC) is investigating the feasibility of a novel combustion concept in which the GHG emissions can be significantly reduced. This concept involves burning fuel and air without mixing these two reactants. If this concept is technically feasible, then CO 2 emissions can be significantly reduced at a much lower cost than more conventional approaches. This indirect combustion concept has been called Chemical Looping Combustion (CLC) because an intermediate material (i.e., a metaloxide) is continuously cycled to oxidize the fuel.more » This CLC concept is the focus of this research and will be described in more detail in the following sections.« less

Real Time Energy Management Control Strategies for Hybrid Powertrains

NASA Astrophysics Data System (ADS)

Zaher, Mohamed Hegazi Mohamed

In order to improve fuel efficiency and reduce emissions of mobile vehicles, various hybrid power-train concepts have been developed over the years. This thesis focuses on embedded control of hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy for continuous operations. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, or the motion is driven by gravitational force, or load driven. There are three main concepts for regernerative energy storing devices in hybrid vehicles: electric, hydraulic, and flywheel. The real time control challenge is to balance the system power demand from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle, while making optimal use of the energy saving opportunities in a given operational, often repetitive cycle. In the worst case scenario, only engine is used and hybrid system completely disabled. A rule based control is developed and tuned for different work cycles and linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the machine and its position via GPS, and maps them to the gains.

Non-OEM experience with NOx reduction applications

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

Birchett, K.S.; Chung, L.; Caldwell, R.E.

1996-01-01

Heightened global environmental awareness and mandated deadlines for emission compliance required by the Clean Air Act, demand operators to increase controls on boiler emissions. For decades, the utility boiler industry has been dominated by the large OEM`s. In the past, boiler owners would approach the company that originally designed the boiler or burner system to design a burner system to reduce emissions. It was commonly believed that the boiler manufacturer had the greatest expertise in the area of NO{sub x} reduction. Current experience demonstrates that boiler owners are accepting new approaches to reducing NO{sub x} from non-OEM designers and suppliers.more » This paper outlines new approaches being applied by boiler operators to reduce NO{sub x} emissions. Several steps are imperative for a successful NO{sub x} reduction program and each step of this process will be described with examples presented. Concepts that will be examined are: (1) Practical designing concerns of theoretical Low NO{sub x} combustion, (2) Reviewing scope requirements required to reduce emissions, and (3) Teaming with the Customer to facilitate retrofit design and installation. The emphasis of this paper is not directed at the theory of how the components reduce NO{sub x}, but how to effectively apply proven technology that reduced NO{sub x} emissions.« less

Experimental clean combustor program, phase 2

NASA Technical Reports Server (NTRS)

Gleason, C. C.; Rogers, D. W.; Bahr, D. W.

1976-01-01

The primary objectives of this three-phase program are to develop technology for the design of advanced combustors with significantly lower pollutant emission levels than those of current combustors, and to demonstrate these pollutant emission reductions in CF6-50C engine tests. The purpose of the Phase 2 Program was to further develop the two most promising concepts identified in the Phase 1 Program, the double annular combustor and the radial/axial staged combustor, and to design a combustor and breadboard fuel splitter control for CF6-50 engine demonstration testing in the Phase 3 Program. Noise measurement and alternate fuels addendums to the basic program were conducted to obtain additional experimental data. Twenty-one full annular and fifty-two sector combustor configurations were evaluated. Both combustor types demonstrated the capability for significantly reducing pollutant emission levels. The most promising results were obtained with the double annular combustor. Rig test results corrected to CF-50C engine conditions produced EPA emission parameters for CO, HC, and NOX of 3.4, 0.4, and 4.5 respectively. These levels represent CO, HC, and NOX reductions of 69, 90, and 42 percent respectively from current combustor emission levels. The combustor also met smoke emission level requirements and development engine performance and installation requirements.

Spray combustion experiments and numerical predictions

NASA Technical Reports Server (NTRS)

Mularz, Edward J.; Bulzan, Daniel L.; Chen, Kuo-Huey

1993-01-01

The next generation of commercial aircraft will include turbofan engines with performance significantly better than those in the current fleet. Control of particulate and gaseous emissions will also be an integral part of the engine design criteria. These performance and emission requirements present a technical challenge for the combustor: control of the fuel and air mixing and control of the local stoichiometry will have to be maintained much more rigorously than with combustors in current production. A better understanding of the flow physics of liquid fuel spray combustion is necessary. This paper describes recent experiments on spray combustion where detailed measurements of the spray characteristics were made, including local drop-size distributions and velocities. Also, an advanced combustor CFD code has been under development and predictions from this code are compared with experimental results. Studies such as these will provide information to the advanced combustor designer on fuel spray quality and mixing effectiveness. Validation of new fast, robust, and efficient CFD codes will also enable the combustor designer to use them as additional design tools for optimization of combustor concepts for the next generation of aircraft engines.

Research Data Acquired in World-Class, 60-atm Subsonic Combustion Rig

NASA Technical Reports Server (NTRS)

Lee, Chi-Ming; Wey, Changlie

1999-01-01

NASA Lewis Research Center's new, world-class, 60-atmosphere (atm) combustor research facility, the Advanced Subsonic Combustion Rig (ASCR), is in operation and producing highly unique research data. Specifically, data were acquired at high pressures and temperatures representative of future subsonic engines from a fundamental flametube configuration with an advanced fuel injector. The data acquired include exhaust emissions as well as pressure and temperature distributions. Results to date represent an improved understanding of nitrous oxide (NOx) formation at high pressures and temperatures and include an NOx emissions reduction greater than 70 percent with an advanced fuel injector at operating pressures to 800 pounds per square inch absolute (psia). ASCR research is an integral part of the Advanced Subsonic Technology (AST) Propulsion Program. This program is developing critical low-emission combustion technology that will result in the next generation of gas turbine engines producing 50 to 70 percent less NOx emissions in comparison to 1996 International Civil Aviation Organization (ICAO) limits. The results to date indicate that the AST low-emission combustor goals of reducing NOx emissions by 50 to 70 percent are feasible. U.S. gas turbine manufacturers have started testing the low-emissions combustors at the ASCR. This collaborative testing will enable the industry to develop low-emission combustors at the high pressure and temperature conditions of future subsonic engines. The first stage of the flametube testing has been implemented. Four GE Aircraft Engines low-emissions fuel injector concepts, three Pratt & Whitney concepts, and two Allison concepts have been tested at Lewis ASCR facility. Subsequently, the flametube was removed from the test stand, and the sector combustor was installed. The testing of low emissions sector has begun. Low-emission combustors developed as a result of ASCR research will enable U.S. engine manufacturers to compete on a worldwide basis by producing environmentally acceptable commercial engines.

Concept for Mars Volcanic Emission Life Scout 3-D Artist Concept

NASA Image and Video Library

2004-12-21

This artist rendition depicts a concept for a Mars orbiter that would scrutinize the martian atmosphere for chemical traces of life or environments supportive of life that might be present anywhere on the planet. 3D glasses are necessary.

Comparing the greenhouse gas emissions from three alternative waste combustion concepts

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

Vainikka, Pasi, E-mail: pasi.vainikka@vtt.fi; Tsupari, Eemeli; Sipilae, Kai

2012-03-15

Highlights: Black-Right-Pointing-Pointer Significant GHG reductions are possible by efficient WtE technologies. Black-Right-Pointing-Pointer CHP and high power-to-heat ratio provide significant GHG savings. Black-Right-Pointing-Pointer N{sub 2}O and coal mine type are important in LCA GHG emissions of FBC co-combustion. Black-Right-Pointing-Pointer Substituting coal and fuel oil by waste is beneficial in electricity and heat production. Black-Right-Pointing-Pointer Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system.more » The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO{sub 2}-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.« less

Investigations of the Controlling Factors for Air Emissions Associated With the Dredging of Indiana Harbor and Canal (IHC) and CDF Operations

DTIC Science & Technology

2008-04-01

concepts of a transient toxic constituent loss and transport model for both solids and chemical incorporating a kinetic approach rather than equilibrium...to air. A transient kinetic mass-transfer model was applied to the data and it was found that the TSS level was the most critical parameter for...measured (Thibodeaux et al. 2004). The transient behavior followed the expected theory of the mass-transfer kinetic, but the conventional LEA model

Globally sustainable manganese metal production and use.

PubMed

Hagelstein, Karen

2009-09-01

The "cradle to grave" concept of managing chemicals and wastes has been a descriptive analogy of proper environmental stewardship since the 1970s. The concept incorporates environmentally sustainable product choices-such as metal alloys utilized steel products which civilization is dependent upon. Manganese consumption is related to the increasing production of raw steel and upgrading ferroalloys. Nonferrous applications of manganese include production of dry-cell batteries, plant fertilizer components, animal feed and colorant for bricks. The manganese ore (high grade 35% manganese) production world wide is about 6 million ton/year and electrolytic manganese metal demand is about 0.7 million ton/year. The total manganese demand is consumed globally by industries including construction (23%), machinery (14%), and transportation (11%). Manganese is recycled within scrap of iron and steel, a small amount is recycled within aluminum used beverage cans. Recycling rate is 37% and efficiency is estimated as 53% [Roskill Metals and Minerals Reports, January 13, 2005. Manganese Report: rapid rise in output caused by Chinese crude steel production. Available from: http://www.roskill.com/reports/manganese.]. Environmentally sustainable management choices include identifying raw material chemistry, utilizing clean production processes, minimizing waste generation, recycling materials, controlling occupational exposures, and collecting representative environmental data. This paper will discuss two electrolytically produced manganese metals, the metal production differences, and environmental impacts cited to date. The two electrolytic manganese processes differ due to the addition of sulfur dioxide or selenium dioxide. Adverse environmental impacts due to use of selenium dioxide methodology include increased water consumption and order of magnitude greater solid waste generation per ton of metal processed. The use of high grade manganese ores in the electrolytic process also reduces the quantity of solid wastes generated during processing. Secondary aluminum facilities have reported hazardous waste generation management issues due to baghouse dusts from rotary furnaces processing selenium contaminated manganese alloys. Environmental impacts resulting from industry are represented by emission inventories of chemical releases to the air, water, and soil. The U.S. metals industry releases reported to EPA Toxic Release Inventory indicate the primary metals industry is the major source of metal air toxic emissions, exceeding electric utility air toxic emissions. The nonferrous metals industry is reported to be the Organization for Economic Co-operation and Development (OECD) most intensive airborne and land pollution source of bioaccumulative metals. However, total waste emissions from industries in the OECD countries have declined due to improving energy consumption. Emission registers and access are improving around the world. However, environmental databases for metal particulates have low confidence ratings since the majority of air toxic emissions are not reported, not monitored, or are estimated based on worst-case emission factors. Environmental assessments including biological monitoring are necessary to validate mandated particulate metal emission reductions and control technologies during metal processing.

Multi-source SO2 emission retrievals and consistency of satellite and surface measurements with reported emissions

NASA Astrophysics Data System (ADS)

Fioletov, Vitali; McLinden, Chris A.; Kharol, Shailesh K.; Krotkov, Nickolay A.; Li, Can; Joiner, Joanna; Moran, Michael D.; Vet, Robert; Visschedijk, Antoon J. H.; Denier van der Gon, Hugo A. C.

2017-10-01

Reported sulfur dioxide (SO2) emissions from US and Canadian sources have declined dramatically since the 1990s as a result of emission control measures. Observations from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and ground-based in situ measurements are examined to verify whether the observed changes from SO2 abundance measurements are quantitatively consistent with the reported changes in emissions. To make this connection, a new method to link SO2 emissions and satellite SO2 measurements was developed. The method is based on fitting satellite SO2 vertical column densities (VCDs) to a set of functions of OMI pixel coordinates and wind speeds, where each function represents a statistical model of a plume from a single point source. The concept is first demonstrated using sources in North America and then applied to Europe. The correlation coefficient between OMI-measured VCDs (with a local bias removed) and SO2 VCDs derived here using reported emissions for 1° by 1° gridded data is 0.91 and the best-fit line has a slope near unity, confirming a very good agreement between observed SO2 VCDs and reported emissions. Having demonstrated their consistency, seasonal and annual mean SO2 VCD distributions are calculated, based on reported point-source emissions for the period 1980-2015, as would have been seen by OMI. This consistency is further substantiated as the emission-derived VCDs also show a high correlation with annual mean SO2 surface concentrations at 50 regional monitoring stations.

A Morphing Radiator for High-Turndown Thermal Control of Crewed Space Exploration Vehicles

NASA Technical Reports Server (NTRS)

Cognata, Thomas J.; Hardtl, Darren; Sheth, Rubik; Dinsmore, Craig

2015-01-01

Spacecraft designed for missions beyond low earth orbit (LEO) face a difficult thermal control challenge, particularly in the case of crewed vehicles where the thermal control system (TCS) must maintain a relatively constant internal environment temperature despite a vastly varying external thermal environment and despite heat rejection needs that are contrary to the potential of the environment. A thermal control system is in other words required to reject a higher heat load to warm environments and a lower heat load to cold environments, necessitating a quite high turndown ratio. A modern thermal control system is capable of a turndown ratio of on the order of 12:1, but for crew safety and environment compatibility these are massive multi-loop fluid systems. This paper discusses the analysis of a unique radiator design which employs the behavior of shape memory alloys (SMA) to vary the turndown of, and thus enable, a single-loop vehicle thermal control system for space exploration vehicles. This design, a morphing radiator, varies its shape in response to facesheet temperature to control view of space and primary surface emissivity. Because temperature dependence is inherent to SMA behavior, the design requires no accommodation for control, instrumentation, nor power supply in order to operate. Thermal and radiation modeling of the morphing radiator predict a turndown ranging from 11.9:1 to 35:1 independent of TCS configuration. Stress and deformation analyses predict the desired morphing behavior of the concept. A system level mass analysis shows that by enabling a single loop architecture this design could reduce the TCS mass by between 139 kg and 225 kg. The concept is demonstrated in proof-of-concept benchtop tests.

A Morphing Radiator for High-Turndown Thermal Control of Crewed Space Exploration Vehicles

NASA Technical Reports Server (NTRS)

Cognata, Thomas J.; Hartl, Darren J.; Sheth, Rubik; Dinsmore, Craig

2014-01-01

Spacecraft designed for missions beyond low earth orbit (LEO) face a difficult thermal control challenge, particularly in the case of crewed vehicles where the thermal control system (TCS) must maintain a relatively constant internal environment temperature despite a vastly varying external thermal environment and despite heat rejection needs that are contrary to the potential of the environment. A thermal control system may be required to reject a higher heat load to warm environments and a lower heat load to cold environments, necessitating a relatively high turndown ratio. A modern thermal control system is capable of a turndown ratio of on the order of 12:1, but crew safety and environment compatibility have constrained these solutions to massive multi-loop fluid systems. This paper discusses the analysis of a unique radiator design that employs the behavior of shape memory alloys (SMAs) to vary the turndown of, and thus enable, a single-loop vehicle thermal control system for space exploration vehicles. This design, a morphing radiator, varies its shape in response to facesheet temperature to control view of space and primary surface emissivity. Because temperature dependence is inherent to SMA behavior, the design requires no accommodation for control, instrumentation, or power supply in order to operate. Thermal and radiation modeling of the morphing radiator predict a turndown ranging from 11.9:1 to 35:1 independent of TCS configuration. Coupled thermal-stress analyses predict that the desired morphing behavior of the concept is attainable. A system level mass analysis shows that by enabling a single loop architecture this design could reduce the TCS mass by between 139 kg and 225 kg. The concept has been demonstrated in proof-of-concept benchtop tests.

Experimental Investigation of a Multiplex Fuel Injector Module With Discrete Jet Swirlers for Low Emission Combustors

NASA Technical Reports Server (NTRS)

Tacina, Robert; Mao, Chien-Pei; Wey, Changlie

2004-01-01

A low-NOx emissions combustor concept has been demonstrated in flame-tube tests. A lean-direct injection (LDI) concept was used where the fuel is injected directly into the flame zone and the overall equivalence ratio of the mixture is lean. The LDI concept described in this report is a multiplex fuel injector module containing multipoint fuel injection tips and multi-burning zones. The injector module comprises 25 equally spaced injection tips within a 76 by 76 mm area that fits into the flame-tube duct. The air swirlers were made from a concave plate on the axis of the fuel injector using drilled holes at an angle to the axis of the fuel injector. The NOx levels were quite low and are greater than 70 percent lower than the 1996 ICAO standard. At an inlet temperature of 810 K, inlet pressure of 2760 kPa, pressure drop of 4 percent and a flame temperature of 1900 K with JP8 fuel, the NOx emission index was 9. The 25-point injector module exhibited the most uniform radial distribution of fuel-air mixture and NOx emissions in the flame tube when compared to other multipoint injection devices. A correlation is developed relating the NOx emissions to inlet temperature, inlet pressure, equivalence ratio and pressure drop.

Magnetic levitation assisted aircraft take-off and landing (feasibility study - GABRIEL concept)

NASA Astrophysics Data System (ADS)

Rohacs, Daniel; Rohacs, Jozsef

2016-08-01

The Technology Roadmap 2013 developed by the International Air Transport Association envisions the option of flying without an undercarriage to be in operation by 2032. Preliminary investigations clearly indicate that magnetic levitation technology (MagLev) might be an appealing solution to assist the aircraft take-off and landing. The EU supported research project, abbreviated as GABRIEL, was dealing with (i) the concept development, (ii) the identification, evaluation and selection of the deployable magnetic levitation technology, (iii) the definition of the core system elements (including the required aircraft modifications, the ground-based system and airport elements, and the rendezvous control system), (iv) the analysis of the safety and security aspects, (v) the concept validation and (vi) the estimation of the proposed concept impact in terms of aircraft weight, noise, emission, cost-benefit). All results introduced here are compared to a medium size hypothetic passenger aircraft (identical with an Airbus A320). This paper gives a systematic overview of (i) the applied methods, (ii) the investigation of the possible use of magnetic levitation technology to assist the commercial aircraft take-off and landing processes and (iii) the demonstrations, validations showing the feasibility of the radically new concept. All major results are outlined.

A unifying conceptual model for the environmental responses of isoprene emissions from plants

PubMed Central

Morfopoulos, Catherine; Prentice, Iain C.; Keenan, Trevor F.; Friedlingstein, Pierre; Medlyn, Belinda E.; Peñuelas, Josep; Possell, Malcolm

2013-01-01

Background and Aims Isoprene is the most important volatile organic compound emitted by land plants in terms of abundance and environmental effects. Controls on isoprene emission rates include light, temperature, water supply and CO2 concentration. A need to quantify these controls has long been recognized. There are already models that give realistic results, but they are complex, highly empirical and require separate responses to different drivers. This study sets out to find a simpler, unifying principle. Methods A simple model is presented based on the idea of balancing demands for reducing power (derived from photosynthetic electron transport) in primary metabolism versus the secondary pathway that leads to the synthesis of isoprene. This model's ability to account for key features in a variety of experimental data sets is assessed. Key results The model simultaneously predicts the fundamental responses observed in short-term experiments, namely: (1) the decoupling between carbon assimilation and isoprene emission; (2) a continued increase in isoprene emission with photosynthetically active radiation (PAR) at high PAR, after carbon assimilation has saturated; (3) a maximum of isoprene emission at low internal CO2 concentration (ci) and an asymptotic decline thereafter with increasing ci; (4) maintenance of high isoprene emissions when carbon assimilation is restricted by drought; and (5) a temperature optimum higher than that of photosynthesis, but lower than that of isoprene synthase activity. Conclusions A simple model was used to test the hypothesis that reducing power available to the synthesis pathway for isoprene varies according to the extent to which the needs of carbon assimilation are satisfied. Despite its simplicity the model explains much in terms of the observed response of isoprene to external drivers as well as the observed decoupling between carbon assimilation and isoprene emission. The concept has the potential to improve global-scale modelling of vegetation isoprene emission. PMID:24052559

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

Karpenko, V.; Salmon, J.

The goal of this project was to work together through the project phases to conceive, demonstrate, and produce concepts for detecting, locating, tracking, imaging, and assessing emissions passively or actively. The initial Sensor Concept Exploration Phase was postulated and assessed concepts at a first-order level to ascertain whether the parties’ concepts (either separately developed or jointly developed) had merit for missile defense and homeland security applications

Stratified Charge Engines

DOT National Transportation Integrated Search

1976-01-01

This report reviews stratified charge concepts and engines, with emphasis on the important issues of exhaust emissions, fuel economy, and performance. Divided and open chamber designs are discussed. Potential improvements in exhaust emissions and fue...

Exhaust emissions reduction for intermittent combustion aircraft engines

NASA Technical Reports Server (NTRS)

Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

1982-01-01

Three concepts which, to an aircraft piston engine, provide reductions in exhaust emissions of hydrocarbons and carbon monoxide while simultaneously improving fuel economy. The three chosen concepts, (1) an improved fuel injection system, (2) an improved cooling cylinder head, and (3) exhaust air injection, when combined, show a synergistic relationship in achieving these goals. In addition, the benefits of variable ignition timing were explored and both dynamometer and flight testing of the final engine configuration were accomplished.

Remote sensing of methane emissions by combining optical similitude absorption spectroscopy (OSAS) and lidar

NASA Astrophysics Data System (ADS)

Galtier, Sandrine; Anselmo, Christophe; Welschinger, Jean-Yves; Cariou, Jean-Pierre; Sivignon, Jean-François; Miffre, Alain; Rairoux, Patrick

2018-04-01

Monitoring the emission of gases is difficult to achieve in industrial sites and in environments presenting poor infrastructures. Hence, robust methodologies should be developed and coupled to Lidar technology to allow remote sensing of gas emission. OSAS is a new methodology to evaluate gas concentration emission from spectrally integrated differential absorption measurements. Proof of concept of OSAS-Lidar for CH4 emission monitoring is here presented.

Photoswitchable non-fluorescent thermochromic dye-nanoparticle hybrid probes

PubMed Central

Harrington, Walter N.; Haji, Mwafaq R.; Galanzha, Ekaterina I.; Nedosekin, Dmitry A.; Nima, Zeid A.; Watanabe, Fumiya; Ghosh, Anindya; Biris, Alexandru S.; Zharov, Vladimir P.

2016-01-01

Photoswitchable fluorescent proteins with controllable light–dark states and spectral shifts in emission in response to light have led to breakthroughs in the study of cell biology. Nevertheless, conventional photoswitching is not applicable for weakly fluorescent proteins and requires UV light with low depth penetration in bio-tissue. Here we introduce a novel concept of photoswitchable hybrid probes consisting of thermochromic dye and absorbing nanoparticles, in which temperature-sensitive light–dark states and spectral shifts in absorption can be switched through controllable photothermal heating of doped nanoparticles. The proof-of-concept is demonstrated through the use of two different types of temperature-sensitive dyes doped with magnetic nanoparticles and reversibly photoswitched by a near-infrared laser. Photoacoustic imaging revealed the high contrast of these probes, which is sufficient for their visualization in cells and deep tissue. Our results suggest that these new photoswitchable multicolour probes can be used for multimodal cellular diagnostics and potentially for magnetic and photothermal therapy. PMID:27824110

Climate Change and Implications for Prevention. California's Efforts to Provide Leadership.

PubMed

Balmes, John R

2018-04-01

The atmospheric concentration of carbon dioxide (CO 2 ) and the temperature of the earth's surface have been rising in parallel for decades, with the former recently reaching 400 parts per million, consistent with a 1.5°C increase in global warming. Climate change models predict that a "business as usual" approach, that is, no effort to control CO 2 emissions from combustion of fossil fuels, will result in a more than 2°C increase in annual average surface temperature by approximately 2034. With atmospheric warming comes increased air pollution. The concept of a "climate gap" in air quality control captures the decreased effectiveness of regulatory policies to reduce pollution with a hotter climate. Sources of greenhouse gases and climate-forcing aerosols ("black carbon") are the same sources of air pollutants that harm health. California has adopted robust climate change mitigation policies that are also designed to achieve public health cobenefits by improving air quality. These policies include advanced clean car standards, renewable energy, a sustainable communities strategy to limit suburban sprawl, a low carbon fuel standard, and energy efficiency. A market-based mechanism to put a price on CO 2 emissions is the cap-and-trade program that allows capped facilities to trade state-issued greenhouse gas emissions allowances. The "cap" limits total greenhouse gas emissions from all covered sources, and declines over time to progressively reduce emissions. An alternative approach is a carbon tax. California's leadership on air quality and climate change mitigation is increasingly important, given the efforts to slow or even reverse implementation of such policies at the U.S. national level.

Aircraft Emission Scenarios Projected in Year 2015 for the NASA Technology Concept Aircraft (TCA) High Speed Civil Transport

NASA Technical Reports Server (NTRS)

Baughcum, Steven L.; Henderson, Stephen C.

1998-01-01

This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCTs) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The HSCT scenarios are calculated using the NASA technology concept airplane (TCA) and update an earlier report. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer pressure altitude grid and delivered to NASA as electronic files.

Self-Assembly Driven Aggregation-Induced Emission of Copper Nanoclusters: A Novel Technology for Lighting.

PubMed

Liu, Yi; Yao, Dong; Zhang, Hao

2018-04-18

Because of the specific properties including HOMO-LUMO electronic transition, size-dependent fluorescent emission, and intense light absorption, metal nanoclusters (NCs) have been considered to be one of the most competitive color conversion materials in light-emitting diodes (LEDs). However, the monotonous emission color and the low emission stability and intensity of individual metal NCs strongly limit their universal application. Inspired by the concept of "aggregation-induced emission" (AIE), the utilization of highly ordered metal NC assemblies opens a door to resolve these problems. After self-assembly, the emission stability and intensity of metal NC assemblies are enhanced. At the same time, the emission color of metal NC assemblies become tunable. We termed this process as self-assembly driven AIE of metal NCs. In this review, we use Cu NCs as the example to convey the concept that the compact and ordered arrangement can efficiently improve the metal NCs' emission stability, tunability, and intensity. We first introduce the synthesis of 2D Cu NC self-assemblies and their emissions. We further summarize some of the factors that can affect the emissions of 2D Cu NC self-assemblies. We then discuss the utilization of 2D Cu NC self-assemblies as color conversion materials for LEDs. At last, we outline current challenges and our perspectives on the development of this area.

Using the Relationship between Vehicle Fuel Consumption and CO[subscript 2] Emissions to Illustrate Chemical Principles

ERIC Educational Resources Information Center

Oliver-Hoyo, Maria T.; Pinto, Gabriel

2008-01-01

This instructional resource utilizes consumer product information by which students compare theoretical stoichiometric calculations to CO[subscript 2] car emissions and fuel consumption data. Representing graphically the emission of CO[subscript 2] versus consumption of fuel provides a tangible way of connecting concepts studied in chemistry…

Hydrogen-enrichment-concept preliminary evaluation

NASA Technical Reports Server (NTRS)

Ecklund, E. E.

1975-01-01

A hydrogen-enriched fuels concept for automobiles is described and evaluated in terms of fuel consumption and engine exhaust emissions through multicylinder (V-8) automotive engine/hydrogen generator tests, single cylinder research engine (CFR) tests, and hydrogen-generator characterization tests. Analytical predictions are made of the fuel consumption and NO/sub x/ emissions which would result from anticipated engine improvements. The hydrogen-gas generator, which was tested to quantify its thermodynamic input-output relationships was used for integrated testing of the V-8 engine and generator.

Compliant Metal Enhanced Convection Cooled Reverse-Flow Annular Combustor

NASA Technical Reports Server (NTRS)

Paskin, Marc D.; Acosta, Waldo A.

1994-01-01

A joint Army/NASA program was conducted to design, fabricate, and test an advanced, reverse-flow, small gas turbine combustor using a compliant metal enhanced (CME) convection wall cooling concept. The objectives of this effort were to develop a design method (basic design data base and analysis) for the CME cooling technique and tben demonstrate its application to an advanced cycle, small, reverse-flow combustor with 3000 F (1922 K) burner outlet temperature (BOT). The CME concept offers significant improvements in wall cooling effectiveness resulting in a large reduction in cooling air requirements. Therefore, more air is available for control of burner outlet temperature pattern in addition to the benefit of improved efficiency, reduced emissions, and smoke levels. Rig test results demonstrated the benefits and viability of the CME concept meeting or exceeding the aerothermal performance and liner wall temperature characteristics of similar lower temperature-rise combustors, achieving 0.15 pattern factor at 3000 F (1922 K) BOT, while utilizing approximately 80 percent less cooling air than conventional, film-cooled combustion systems.

Ecotoxicological criteria for final storage quality: Possibilities and limits

NASA Astrophysics Data System (ADS)

Zeyer, Josef; Meyer, Joseph

Landfills are complex chemical and biological reactors whose internal processes are often beyond the immediate control of process engineers. Therefore, the concept of a "Final Storage Landfill" may be deceptive. Furthermore, traditional approaches to establishing discharge criteria and treatment requirements for industrial effluents may not work well for landfill emissions. Factories can often be treated as steady-state processes whose inputs and outputs are predictable; however, landfills are batch reactors whose contents and emissions may be unknown and will vary temporally and spatially. If the contents of a landfill are known, the sequence of chemical reactions can be predicted qualitatively. Even if that sequence is predictable, though, quantitative ecotoxicological criteria will be difficult to establish, and risk assessments based on chemical "laundry lists" will be questionable. The situation is not hopeless, though. New approaches can be developed to monitor and predict landfill emissions. We believe these will include (1) testing (biological and chemical) of internal components of landfills as well as emissions; (2) development of laboratory and/or field methods in which the chemical and biological evolution of landfills can be studied at accelerated rates, thus allowing better prediction of future emissions; and (3) flexible ecotoxicological criteria that are adaptable to the evolving nature of landfill emissions. These criteria should be based on complementary chemical analyses and biological tests that fit into a hierarchical (decision-tree) hazard assessment strategy.

Meteorological and ecological monitoring of the stratosphere and mesosphere

NASA Technical Reports Server (NTRS)

Newell, R. E.; Gray, C. R.

1972-01-01

A concept for determining the constituent densities of ozone, atomic oxygen, aerosols, and neutral density in the 20 to 1000 km region of the atmosphere from a satellite was developed. The concept includes the daytime measurement of solar scattering at the earth's limb in selected narrow spectral bands of the ultraviolet and visible regions, and the measurement of selected (dayglow) emissions. Nighttime measurements of the atmospheric extinction of stellar energy in selected bands are also considered as are simultaneous measurements of the 5577 airglow and molecular oxygen emission in the Herzberg band. Radiative-transfer models and recursive inversion algorithms are developed for the measurements, and the accuracy of the concept is assessed.

Concept for Mars Volcanic Emission Life Scout

NASA Image and Video Library

2004-12-21

This artist rendition depicts a concept for NASA Mars orbiter that would scrutinize the martian atmosphere for chemical traces of life or environments supportive of life that might be present anywhere on the planet.

NASA/General Electric broad-specification fuels combustion technology program - Phase I results and status

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Ekstedt, E. E.; Bahr, D. W.; Fear, J. S.

1982-01-01

A program is being conducted to develop the technology required to utilize fuels with broadened properties in aircraft gas turbine engines. The first phase of this program consisted of the experimental evaluation of three different combustor concepts to determine their potential for meeting several specific emissions and performance goals, when operated on broadened property fuels. The three concepts were a single annular combustor; a double annular combustor; and a short single annular combustor with variable geometry. All of these concepts were sized for the General Electric CF6-80 engine. A total of 24 different configurations of these concepts were evaluated in a high pressure test facility, using four test fuels having hydrogen contents between 11.8 and 14%. Fuel effects on combustor performance, durability and emissions, and combustor design features to offset these effects were demonstrated.

Hybrid Wing Body Configuration Scaling Study

NASA Technical Reports Server (NTRS)

Nickol, Craig L.

2012-01-01

The Hybrid Wing Body (HWB) configuration is a subsonic transport aircraft concept with the potential to simultaneously reduce fuel burn, noise and emissions compared to conventional concepts. Initial studies focused on very large applications with capacities for up to 800 passengers. More recent studies have focused on the large, twin-aisle class with passenger capacities in the 300-450 range. Efficiently scaling this concept down to the single aisle or smaller size is challenging due to geometric constraints, potentially reducing the desirability of this concept for applications in the 100-200 passenger capacity range or less. In order to quantify this scaling challenge, five advanced conventional (tube-and-wing layout) concepts were developed, along with equivalent (payload/range/technology) HWB concepts, and their fuel burn performance compared. The comparison showed that the HWB concepts have fuel burn advantages over advanced tube-and-wing concepts in the larger payload/range classes (roughly 767-sized and larger). Although noise performance was not quantified in this study, the HWB concept has distinct noise advantages over the conventional tube-and-wing configuration due to the inherent noise shielding features of the HWB. NASA s Environmentally Responsible Aviation (ERA) project will continue to investigate advanced configurations, such as the HWB, due to their potential to simultaneously reduce fuel burn, noise and emissions.

Soil Greenhouse Gas Emissions from a Subtropical Mangrove in Hong Kong

NASA Astrophysics Data System (ADS)

Lai, D. Y. F.; Xu, J.

2014-12-01

The concept of "blue carbon" has received increasing attention recently, which points to the potential role of vegetated coastal wetlands in carbon sequestration. Yet, the magnitude and controls of greenhouse gas emissions from coastal wetland ecosystems, especially mangroves in the subtropical regions, are still largely unknown. In this study, we conducted chamber measurements in the Mai Po Marshes Nature Reserve of Hong Kong at monthly intervals to characterize the spatial and temporal variability of the emission of greenhouse gases, including CO2, CH4 and N2O from mangrove soils, and examine the influence of environmental and biotic variables on greenhouse gas fluxes. We found the highest mean CH4 and N2O emissions in autumn and the highest CO2 flux in summer. Along the tidal gradient, we observed significantly higher CH4 and N2O emissions from the middle zones and landward zones, respectively, while no clear spatial variation of CO2 emissions was observed. There were significantly higher soil greenhouse gas emissions from sites dominated by Avicennia marina than those dominated by Kandelia obovata, which might be due to the presence of pneumatophores which facilitated gas transport. We found a significant, negative correlation between CH4 flux and soil NO3-N concentration, while CO2 flux was positively correlation with total Kjeldahl nitrogen content. Soil temperature was positively correlated with the emissions of all three greenhouse gases, while water table depth was positively and negatively correlated with CH4 and N2O emissions, respectively. Our findings demonstrate the high spatial and temporal variability of greenhouse gas emissions from mangrove soils which could be attributed in part to the differences in environmental conditions and dominant plant species.

Low-Emission combustion of fuel in aeroderivative gas turbines

NASA Astrophysics Data System (ADS)

Bulysova, L. A.; Vasil'ev, V. D.; Berne, A. L.

2017-12-01

The paper is the first of a planned set of papers devoted to the world experience in development of Low Emission combustors (LEC) for industrial Gas Turbines (GT). The purpose of the article is to summarize and analyze the most successful experience of introducing the principles of low-emission combustion of the so-called "poor" (low fuel concentration in air when the excess air ratio is about 1.9-2.1) well mixed fuelair mixtures in the LEC for GTs and ways to reduce the instability of combustion. The consideration examples are the most successful and widely used aero-derivative GT. The GT development meets problems related to the difference in requirements and operation conditions between the aero, industrial, and power production GT. One of the main problems to be solved is the LEC development to mitigate emissions of the harmful products first of all the Nitrogen oxides NOx. The ways to modify or convert the initial combustors to the LEC are shown. This development may follow location of multiburner mixers within the initial axial envelope dimensions or conversion of circular combustor to the can type one. The most interesting are Natural Gas firing GT without water injection into the operating process or Dry Low emission (DLE) combustors. The current GT efficiency requirement may be satisfied at compressor exit pressure above 3 MPa and Turbine Entry temperature (TET) above 1500°C. The paper describes LEC examples based on the concept of preliminary prepared air-fuel mixtures' combustion. Each combustor employs its own fuel supply control concept based on the fuel flow-power output relation. In the case of multiburner combustors, the burners are started subsequently under a specific scheme. The can type combustors have combustion zones gradually ignited following the GT power change. The combustion noise problem experienced in lean mixtures' combustion is also considered, and the problem solutions are described. The GT test results show wide ranges of stable operation at needed levels of NOx and CO emissions. The world experience analysis and generalization and investigation of the further development directions for the high performance GT will assist development of domestic LEC for prospective GTs.

Towards Intelligent Control for Next Generation Aircraft

NASA Technical Reports Server (NTRS)

Acosta, Diana Michelle; KrishnaKumar, Kalmanje Srinvas; Frost, Susan Alane

2008-01-01

NASA Aeronautics Subsonic Fixed Wing Project is focused on mitigating the environmental and operation impacts expected as aviation operations triple by 2025. The approach is to extend technological capabilities and explore novel civil transport configurations that reduce noise, emissions, fuel consumption and field length. Two Next Generation (NextGen) aircraft have been identified to meet the Subsonic Fixed Wing Project goals - these are the Hybrid Wing-Body (HWB) and Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The technologies and concepts developed for these aircraft complicate the vehicle s design and operation. In this paper, flight control challenges for NextGen aircraft are described. The objective of this paper is to examine the potential of state-of-the-art control architectures and algorithms to meet the challenges and needed performance metrics for NextGen flight control. A broad range of conventional and intelligent control approaches are considered, including dynamic inversion control, integrated flight-propulsion control, control allocation, adaptive dynamic inversion control, data-based predictive control and reinforcement learning control.

40 CFR 93.115 - Criteria and procedures: Projects from a transportation plan and TIP.

Code of Federal Regulations, 2010 CFR

2010-07-01

... included in the conforming transportation plan and the project's design concept and scope have not changed... the design concept and scope of the project were adequate at the time of the TIP conformity determination to determine its contribution to the TIP's regional emissions, and the project design concept and...

Advanced technology for reducing aircraft engine pollution

NASA Technical Reports Server (NTRS)

Jones, R. E.

1973-01-01

The proposed EPA regulations covering emissions of gas turbine engines will require extensive combustor development. The NASA is working to develop technology to meet these goals through a wide variety of combustor research programs conducted in-house, by contract, and by university grant. In-house efforts using the swirl-can modular combustor have demonstrated sizable reduction in NO emission levels. Testing to reduce idle pollutants has included the modification of duplex fuel nozzles to air-assisted nozzles and an exploration of the potential improvements possible with combustors using fuel staging and variable geometry. The Experimental Clean Combustor Program, a large contracted effort, is devoted to the testing and development of combustor concepts designed to achieve a large reduction in the levels of all emissions. This effort is planned to be conducted in three phases with the final phase to be an engine demonstration of the best reduced emission concepts.

Broad specification fuels technology program, phase 1

NASA Technical Reports Server (NTRS)

Lohmann, R. P.; Jeroszko, R. A.

1982-01-01

An experimental evaluation was conducted to assess the impact of the use of broadened properties fuels on combustor design concepts. Emphasis was placed on establishing the viability of design modifications to current combustor concepts and the use of advanced technology concepts to facilitate operation on Experimental Referee Broad Specification (ERBS) fuel while meeting exhaust emissions and performance specifications and maintaining acceptable durability. Three different combustor concepts, representative of progressively more aggressive technology levels, were evaluated. When operated on ERBS rather than Jet A fuel, a single stage combustor typical of that in the most recent versions of the JT9D-7 engine was found to produce excess carbon monoxide emissions at idle and elevated liner temperatures at high power levels that were projected to reduced liner life by 13 percent. The introduction of improved component technology, such as refined fuel injectors and advanced liner cooling concepts were shown to have the potential of enhancing the fuel flexibility of the single stage combustor.

Wireless powering of e -swimmers

NASA Astrophysics Data System (ADS)

Roche, Jérome; Carrara, Serena; Sanchez, Julien; Lannelongue, Jérémy; Loget, Gabriel; Bouffier, Laurent; Fischer, Peer; Kuhn, Alexander

2014-10-01

Miniaturized structures that can move in a controlled way in solution and integrate various functionalities are attracting considerable attention due to the potential applications in fields ranging from autonomous micromotors to roving sensors. Here we introduce a concept which allows, depending on their specific design, the controlled directional motion of objects in water, combined with electronic functionalities such as the emission of light, sensing, signal conversion, treatment and transmission. The approach is based on electric field-induced polarization, which triggers different chemical reactions at the surface of the object and thereby its propulsion. This results in a localized electric current that can power in a wireless way electronic devices in water, leading to a new class of electronic swimmers (e-swimmers).

Control Design and Performance Analysis for Autonomous Formation Flight Experimentss

NASA Astrophysics Data System (ADS)

Rice, Caleb Michael

Autonomous Formation Flight is a key approach for reducing greenhouse gas emissions and managing traffic in future high density airspace. Unmanned Aerial Vehicles (UAV's) have made it possible for the physical demonstration and validation of autonomous formation flight concepts inexpensively and eliminates the flight risk to human pilots. This thesis discusses the design, implementation, and flight testing of three different formation flight control methods, Proportional Integral and Derivative (PID); Fuzzy Logic (FL); and NonLinear Dynamic Inversion (NLDI), and their respective performance behavior. Experimental results show achievable autonomous formation flight and performance quality with a pair of low-cost unmanned research fixed wing aircraft and also with a solo vertical takeoff and landing (VTOL) quadrotor.

Large Engine Technology Program. Task 22: Variable Geometry Concepts for Rich-Quench-Lean Combustors

NASA Technical Reports Server (NTRS)

Tacina, Robert R. (Technical Monitor); Cohen, J. M.; Padget, F. C.; Kwoka, D.; Wang, Q.; Lohmann, R. P.

2005-01-01

The objective of the task reported herein was to define, evaluate, and optimize variable geometry concepts suitable for use with a Rich-Quench-Lean (RQL) combustor. The specific intent was to identify approaches that would satisfy High Speed Civil Transport (HSCT) cycle operational requirements with regard to fuel-air ratio turndown capability, ignition, and stability margin without compromising the stringent emissions, performance, and reliability goals that this combustor would have to achieve. Four potential configurations were identified and three of these were refined and tested in a high-pressure modular RQL combustor rig. The tools used in the evolution of these concepts included models built with rapid fabrication techniques that were tested for airflow characteristics to confirm sizing and airflow management capability, spray patternation, and atomization characterization tests of these models and studies that were supported by Computational Fluid Dynamics analyses. Combustion tests were performed with each of the concepts at supersonic cruise conditions and at other critical conditions in the flight envelope, including the transition points of the variable geometry system, to identify performance, emissions, and operability impacts. Based upon the cold flow characterization, emissions results, acoustic behavior observed during the tests and consideration of mechanical, reliability, and implementation issues, the tri-swirler configuration was selected as the best variable geometry concept for incorporation in the RQL combustor evolution efforts for the HSCT.

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.

Phosphene phenomenon: a new concept.

PubMed

Bókkon, István

2008-05-01

This paper proposes a new biopsychophysical concept of phosphene phenomenon. Namely, visual sensation of phosphenes is due to the intrinsic perception of ultraweak bioluminescent photon emission of cells in the visual system. In other words, phosphenes are bioluminescent biophotons in the visual system induced by various stimuli (mechanical, electrical, magnetic, ionizing radiation, etc.) as well as random bioluminescent biophotons firings of cells in the visual pathway. This biophoton emission can become conscious if induced or spontaneous biophoton emission of cells in the visual system exceeds a distinct threshold. Neuronal biophoton communication can occur by means of non-visual neuronal opsins and natural photosensitive biomolecules. Our interpretation is in direct connection with the functional roles of free radicals and excited biomolecules in living cells.

Review of Propulsion Technologies for N+3 Subsonic Vehicle Concepts

NASA Technical Reports Server (NTRS)

Ashcraft, Scott W.; Padron, Andres S.; Pascioni, Kyle A.; Stout, Gary W., Jr.; Huff, Dennis L.

2011-01-01

NASA has set aggressive fuel burn, noise, and emission reduction goals for a new generation (N+3) of aircraft targeting concepts that could be viable in the 2035 timeframe. Several N+3 concepts have been formulated, where the term "N+3" indicate aircraft three generations later than current state-of-the-art aircraft, "N". Dramatic improvements need to be made in the airframe, propulsion systems, mission design, and the air transportation system in order to meet these N+3 goals. The propulsion system is a key element to achieving these goals due to its major role with reducing emissions, fuel burn, and noise. This report provides an in-depth description and assessment of propulsion systems and technologies considered in the N+3 subsonic vehicle concepts. Recommendations for technologies that merit further research and development are presented based upon their impact on the N+3 goals and likelihood of being operational by 2035.

Distributed Propulsion Vehicles

NASA Technical Reports Server (NTRS)

Kim, Hyun Dae

2010-01-01

Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

40 CFR 93.121 - Requirements for adoption or approval of projects by other recipients of funds designated under...

Code of Federal Regulations, 2010 CFR

2010-07-01

... project's design concept and scope have not changed significantly from those that were included in the... selection or endorsement, and the project's design concept and scope have not changed significantly from... concept and scope has not changed significantly; or (2) A new regional emissions analysis including the...

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

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

Victor W. Wong; Tian Tian; Grant Smedley

2003-08-28

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. A detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and concepts have been explored, and engine experiments will validate these concepts. An iterative process of experimentation, simulation and analysis, will be followed with the goal of demonstrating a complete optimized low-friction engine system. As planned, MIT has developed guidelinesmore » for an initial set of low-friction piston-ring-pack designs. Current recommendations focus on subtle top-piston-ring and oil-control-ring characteristics. A full-scale Waukesha F18 engine has been installed at Colorado State University and testing of the baseline configuration is in progress. Components for the first design iteration are being procured. Subsequent work includes examining the friction and engine performance data and extending the analyses to other areas to evaluate opportunities for further friction improvement and the impact on oil consumption/emission and wear, towards demonstrating an optimized reduced-friction engine system.« less

High Pressure Low NOx Emissions Research: Recent Progress at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Chi-Ming, Lee; Tacina, Kathleen M.; Wey, Changlie

2007-01-01

In collaboration with U.S. aircraft engine companies, NASA Glenn Research Center has contributed to the advancement of low emissions combustion systems. For the High Speed Research Program (HSR), a 90% reduction in nitrogen oxides (NOx) emissions (relative to the then-current state of the art) has been demonstrated in sector rig testing at General Electric Aircraft Engines (GEAE). For the Advanced Subsonic Technology Program (AST), a 50% reduction in NOx emissions relative to the 1996 International Civil Aviation Organization (ICAO) standards has been at demonstrated in sector rigs at both GEAE and Pratt & Whitney (P&W). During the Ultra Efficient Engine Technology Program (UEET), a 70% reduction in NOx emissions, relative to the 1996 ICAO standards, was achieved in sector rig testing at Glenn in the world class Advanced Subsonic Combustion Rig (ASCR) and at contractor facilities. Low NOx combustor development continues under the Fundamental Aeronautics Program. To achieve these reductions, experimental and analytical research has been conducted to advance the understanding of emissions formation in combustion processes. Lean direct injection (LDI) concept development uses advanced laser-based non-intrusive diagnostics and analytical work to complement the emissions measurements and to provide guidance for concept improvement. This paper describes emissions results from flametube tests of a 9- injection-point LDI fuel/air mixer tested at inlet pressures up to 5500 kPa. Sample results from CFD and laser diagnostics are also discussed.

NASA Glenn High Pressure Low NOx Emissions Research

NASA Technical Reports Server (NTRS)

Tacina, Kathleen M.; Wey, Changlie

2008-01-01

In collaboration with U.S. aircraft engine companies, NASA Glenn Research Center has contributed to the advancement of low emissions combustion systems. For the High Speed Research Program (HSR), a 90% reduction in nitrogen oxides (NOx) emissions (relative to the then-current state of the art) has been demonstrated in sector rig testing at General Electric Aircraft Engines (GEAE). For the Advanced Subsonic Technology Program (AST), a 50% reduction in NOx emissions relative to the 1996 International Civil Aviation Organization (ICAO) standards has been demonstrated in sector rigs at both GEAE and Pratt & Whitney (P&W). During the Ultra Efficient Engine Technology Program (UEET), a 70% reduction in NOx emissions, relative to the 1996 ICAO standards, was achieved in sector rig testing at Glenn in the world class Advanced Subsonic Combustion Rig (ASCR) and at contractor facilities. Low NOx combustor development continues under the Fundamental Aeronautics Program. To achieve these reductions, experimental and analytical research has been conducted to advance the understanding of emissions formation in combustion processes. Lean direct injection (LDI) concept development uses advanced laser-based non-intrusive diagnostics and analytical work to complement the emissions measurements and to provide guidance for concept improvement. This paper describes emissions results from flametube tests of a 9-injection-point LDI fuel/air mixer tested at inlet pressures up to 5500 kPa. Sample results from CFD and laser diagnostics are also discussed.

Concepts for reducing exhaust emissions and fuel consumption of the aircraft piston engine

NASA Technical Reports Server (NTRS)

Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

1979-01-01

A study was made to reduce exhaust emissions and fuel consumption of a general aviation aircraft piston engine by applying known technology. Fourteen promising concepts such as stratified charge combustion chambers, cooling cylinder head improvements, and ignition system changes were evaluated for emission reduction and cost effectiveness. A combination of three concepts, improved fuel injection system, improved cylinder head with exhaust port liners and exhaust air injection was projected as the most cost effective and safe means of meeting the EPA standards for CO, HC and NO. The fuel economy improvement of 4.6% over a typical single engine aircraft flight profile does not though justify the added cost of the three concepts, and significant reductions in fuel consumption must be applied to the cruise mode where most of the fuel is used. The use of exhaust air injection in combination with exhaust port liners reduces exhaust valve stem temperatures which can result in longer valve guide life. The use of exhaust port liners alone can reduce engine cooling air requirements by 11% which is the equivalent of a 1.5% increase in propulsive power. The EPA standards for CO, HC and NO can be met in the IO-520 engine using air injection alone or the Simmonds improved fuel injection system.

On-board emission measurement of high-loaded light-duty vehicles in Algeria.

PubMed

Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2008-01-01

A sample of eight private gasoline and diesel conventional light-duty vehicles (LDVs) in use with various ages, carrying a load of 460 kg, were tested on a representative trip in the traffic flow of the city of Blida to obtain emission factors representing the actual use conditions of Algerian LDVs. The gas sampling system (mini-constant volume sampling) as well as the analyzers are carried on-board the vehicle. Around 55 tests were conducted during 3 months covering more than 480 km under various real driving conditions. The mean speed downtown is about 16.1 km/hr with a rather low acceleration, an average of 0.60 m/sec2. For each test, kinematics are recorded as well as the analysis of the four emitted pollutants carbon dioxide, carbon monoxide, oxides of nitrogen, and total hydrocarbons. Emission factors were evaluated according to speed for each category of gasoline and diesel engines. The influence of some parameters such as cold/hot start, age of vehicle and its state of maintenance are discussed. Results are compared with the European database ARTEMIS for comparable vehicles. These measurements contribute to the development of unit emission of the vehicles used in Algeria, which are necessary for the calculation of emission inventory of pollutants and greenhouse gases from the road transportation sector. The unit emissions constitute a tool of decisionmaking aid regarding the conception of new regulations of vehicle control and inspection in Algeria and even in similar developing countries.

A rapid response air quality analysis system for use in projects having stringent quality assurance requirements

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

Bowman, A.W.

1990-04-01

This paper describes an approach to solve air quality problems which frequently occur during iterations of the baseline change process. From a schedule standpoint, it is desirable to perform this evaluation in as short a time as possible while budgetary pressures limit the size of the staff available to do the work. Without a method in place to deal with baseline change proposal requests the environment analysts may not be able to produce the analysis results in the time frame expected. Using a concept called the Rapid Response Air Quality Analysis System (RAAS), the problems of timing and cost becomemore » tractable. The system could be adapted to assess other atmospheric pathway impacts, e.g., acoustics or visibility. The air quality analysis system used to perform the EA analysis (EA) for the Salt Repository Project (part of the Civilian Radioactive Waste Management Program), and later to evaluate the consequences of proposed baseline changes, consists of three components: Emission source data files; Emission rates contained in spreadsheets; Impact assessment model codes. The spreadsheets contain user-written codes (macros) that calculate emission rates from (1) emission source data (e.g., numbers and locations of sources, detailed operating schedules, and source specifications including horsepower, load factor, and duty cycle); (2) emission factors such as those published by the U.S. Environmental Protection Agency, and (3) control efficiencies.« less

The 1989 high-speed civil transport studies

NASA Technical Reports Server (NTRS)

1991-01-01

The results of the Douglas Aircraft Company system studies related to high speed civil transports (HSCT) are discussed. The studies were conducted to assess the environmental compatibility of a high speed civil transport at a design Mach number of 3.2. Sonic boom minimization, external noise, and engine emissions were assessed together with the effect of the laminar flow control (LFC) technology on vehicle gross weight. The general results indicated that a sonic boom loudness level of 90-PLdB at Mach 3.2 may not be achievable for a practical design; the high flow engine cycle concept shows promise of achieving the sideline FAR Part 36 noise limit, but may not achieve the aircraft range design goal of 6,500 nautical miles; the rich burn/quick quench (RB/QQ) combustor concept shows promise for achieving low EINO sub x levels when combined with a premixed pilot stage/advanced technology, high power stage duct burner in the Pratt and Whitney variable steam control engine (VSCE); and full chord wing LFC has significant performance and economic advantages relative to the turbulent wing baseline.

The 1989 high-speed civil transport studies

NASA Technical Reports Server (NTRS)

1991-01-01

The results are presented for the Douglas Aircraft Company system studies related to high speed civil transports (HSCTs). The system studies were conducted to assess the environmental compatibility of a HSCT at a design Mach number of 3.2. Sonic boom minimization, exterior noise, and engine emissions were assessed together with the effect of a laminar flow control (LFC) technology on vehicle gross weight. The general results indicated that (1) achievement of a 90 PLdB sonic boom loudness level goal at Mach 3.2 may not be practical; (2) the high flow engine cycle concept shows promise of achieving the side line FAR Part 36 noise limit but may not achieve the aircraft range design goal of 6,500 nautical miles; (3) the rich burn/quick quench (RB/QQ) combustor concept shows promise for achieving low EINO(sub x) levels when combined with a premixed pilot stage/advanced technology high power stage duct burner in the P and W variable stream control engine (VSCE); and (4) full chord wing LFC has significant performance and economic advantages relative to the turbulent wing baseline.

Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer.

PubMed

Hellesen, C; Skiba, M; Dzysiuk, N; Weiszflog, M; Hjalmarsson, A; Ericsson, G; Conroy, S; Andersson-Sundén, E; Eriksson, J; Binda, F

2014-11-01

The fuel ion ratio nt/nd is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., nt/nd = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine nt/nd with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.

Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer

NASA Astrophysics Data System (ADS)

Hellesen, C.; Skiba, M.; Dzysiuk, N.; Weiszflog, M.; Hjalmarsson, A.; Ericsson, G.; Conroy, S.; Andersson-Sundén, E.; Eriksson, J.; Binda, F.

2014-11-01

The fuel ion ratio nt/nd is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., nt/nd = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine nt/nd with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.

AEG-1 promoter-mediated imaging of prostate cancer

PubMed Central

Bhatnagar, Akrita; Wang, Yuchuan; Mease, Ronnie C.; Gabrielson, Matthew; Sysa, Polina; Minn, Il; Green, Gilbert; Simmons, Brian; Gabrielson, Kathleen; Sarkar, Siddik; Fisher, Paul B.; Pomper, Martin G.

2014-01-01

We describe a new imaging method for detecting prostate cancer, whether localized or disseminated and metastatic to soft tissues and bone. The method relies on the use of imaging reporter genes under the control of the promoter of AEG-1 (MTDH), which is selectively active only in malignant cells. Through systemic, nanoparticle-based delivery of the imaging construct, lesions can be identified through bioluminescence imaging and single photon emission-computed tomography in the PC3-ML murine model of prostate cancer at high sensitivity. This approach is applicable for the detection of prostate cancer metastases, including bone lesions for which there is no current reliable agent for non-invasive clinical imaging. Further, the approach compares favorably to accepted and emerging clinical standards, including positron emission tomography with [18F]fluorodeoxyglucose and [18F]sodium fluoride. Our results offer a preclinical proof of concept that rationalizes clinical evaluation in patients with advanced prostate cancer. PMID:25145668

A Study on Homogeneous Charge Compression Ignition Gasoline Engines

NASA Astrophysics Data System (ADS)

Kaneko, Makoto; Morikawa, Koji; Itoh, Jin; Saishu, Youhei

A new engine concept consisting of HCCI combustion for low and midrange loads and spark ignition combustion for high loads was introduced. The timing of the intake valve closing was adjusted to alter the negative valve overlap and effective compression ratio to provide suitable HCCI conditions. The effect of mixture formation on auto-ignition was also investigated using a direct injection engine. As a result, HCCI combustion was achieved with a relatively low compression ratio when the intake air was heated by internal EGR. The resulting combustion was at a high thermal efficiency, comparable to that of modern diesel engines, and produced almost no NOx emissions or smoke. The mixture stratification increased the local A/F concentration, resulting in higher reactivity. A wide range of combustible A/F ratios was used to control the compression ignition timing. Photographs showed that the flame filled the entire chamber during combustion, reducing both emissions and fuel consumption.

Constraining a complex biogeochemical model for CO2 and N2O emission simulations from various land uses by model-data fusion

NASA Astrophysics Data System (ADS)

Houska, Tobias; Kraus, David; Kiese, Ralf; Breuer, Lutz

2017-07-01

This study presents the results of a combined measurement and modelling strategy to analyse N2O and CO2 emissions from adjacent arable land, forest and grassland sites in Hesse, Germany. The measured emissions reveal seasonal patterns and management effects, including fertilizer application, tillage, harvest and grazing. The measured annual N2O fluxes are 4.5, 0.4 and 0.1 kg N ha-1 a-1, and the CO2 fluxes are 20.0, 12.2 and 3.0 t C ha-1 a-1 for the arable land, grassland and forest sites, respectively. An innovative model-data fusion concept based on a multicriteria evaluation (soil moisture at different depths, yield, CO2 and N2O emissions) is used to rigorously test the LandscapeDNDC biogeochemical model. The model is run in a Latin-hypercube-based uncertainty analysis framework to constrain model parameter uncertainty and derive behavioural model runs. The results indicate that the model is generally capable of predicting trace gas emissions, as evaluated with RMSE as the objective function. The model shows a reasonable performance in simulating the ecosystem C and N balances. The model-data fusion concept helps to detect remaining model errors, such as missing (e.g. freeze-thaw cycling) or incomplete model processes (e.g. respiration rates after harvest). This concept further elucidates the identification of missing model input sources (e.g. the uptake of N through shallow groundwater on grassland during the vegetation period) and uncertainty in the measured validation data (e.g. forest N2O emissions in winter months). Guidance is provided to improve the model structure and field measurements to further advance landscape-scale model predictions.

Discrete tuning concept for fiber-integrated lasers based on tailored FBG arrays and a theta cavity layout.

PubMed

Tiess, Tobias; Becker, Martin; Rothhardt, Manfred; Bartelt, Hartmut; Jäger, Matthias

2017-03-15

We demonstrate a novel tuning concept for pulsed fiber-integrated lasers with a fiber Bragg grating (FBG) array as a discrete and tailored spectral filter, as well as a modified laser design. Based on a theta cavity layout, the structural delay lines originating from the FBG array are balanced, enabling a constant repetition rate and stable pulse properties over the full tuning range. The emission wavelength is electrically tuned with respect to the filter properties based on an adapted temporal gating scheme using an acousto-optic modulator. This concept has been investigated with an Yb-doped fiber laser, demonstrating excellent emission properties with high signal contrast (>35  dB) and narrow linewidth (<150  pm) over a tuning range of 25 nm.

Pollution reduction technology program small jet aircraft engines, phase 3

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1981-01-01

A series of Model TFE731-2 engine tests were conducted with the Concept 2 variable geometry airblast fuel injector combustion system installed. The engine was tested to: (1) establish the emission levels over the selected points which comprise the Environmental Protection Agency Landing-Takeoff Cycle; (2) determine engine performance with the combustion system; and (3) evaulate the engine acceleration/deceleration characteristics. The hydrocarbon (HC), carbon monoxide (CO), and smoke goals were met. Oxides of nitrogen (NOx) were above the goal for the same configuration that met the other pollutant goals. The engine and combustor performance, as well as acceleration/deceleration characteristics, were acceptable. The Concept 3 staged combustor system was refined from earlier phase development and subjected to further rig refinement testing. The concept met all of the emissions goals.

Advanced Low-Emissions Catalytic-Combustor Program, phase 1. [aircraft gas turbine engines

NASA Technical Reports Server (NTRS)

Sturgess, G. J.

1981-01-01

Six catalytic combustor concepts were defined, analyzed, and evaluated. Major design considerations included low emissions, performance, safety, durability, installations, operations and development. On the basis of these considerations the two most promising concepts were selected. Refined analysis and preliminary design work was conducted on these two concepts. The selected concepts were required to fit within the combustor chamber dimensions of the reference engine. This is achieved by using a dump diffuser discharging into a plenum chamber between the compressor discharge and the turbine inlet, with the combustors overlaying the prediffuser and the rear of the compressor. To enhance maintainability, the outer combustor case for each concept is designed to translate forward for accessibility to the catalytic reactor, liners and high pressure turbine area. The catalytic reactor is self-contained with air-cooled canning on a resilient mounting. Both selected concepts employed integrated engine-starting approaches to raise the catalytic reactor up to operating conditions. Advanced liner schemes are used to minimize required cooling air. The two selected concepts respectively employ fuel-rich initial thermal reaction followed by rapid quench and subsequent fuel-lean catalytic reaction of carbon monoxide, and, fuel-lean thermal reaction of some fuel in a continuously operating pilot combustor with fuel-lean catalytic reaction of remaining fuel in a radially-staged main combustor.

A Second Generation Swirl-Venturi Lean Direct Injection Combustion Concept

NASA Technical Reports Server (NTRS)

Tacina, Kathleen M.; Chang, Clarence T.; He, Zhuohui Joe; Lee, Phil; Dam, Bidhan; Mongia, Hukam

2014-01-01

A low-NO (sub x) aircraft gas turbine engine combustion concept was developed and tested. The concept is a second generation swirl-venturi lean direct injection (SV-LDI) concept. LDI is a lean-burn combustion concept in which the fuel is injected directly into the flame zone. Three second generation SV-LDI configurations were developed. All three were based on the baseline 9-point SV-LDI configuration reported previously. These second generation configurations had better low power operability than the baseline 9-point configuration. Two of these second generation configurations were tested in a NASA Glenn Research Center flametube; these two configurations are called the at dome and 5-recess configurations. Results show that the 5-recess configuration generally had lower NO (sub x) emissions than the flat dome configuration. Correlation equations were developed for the flat dome configuration so that the landing-takeoff NO (sub x) emissions could be estimated. The flat dome landing-takeoff NO (sub x) is estimated to be 87-88 percent below the CAEP/6 standards, exceeding the ERA project goal of 75 percent reduction.

Ecodriving and carbon footprinting : understanding how public education can reduce greenhouse gas emissions and fuel use [research brief].

DOT National Transportation Integrated Search

2012-04-01

Ecodriving, the concept of altering driving behavior and vehicle maintenance practices in existing vehicles, has gained recent prominence as a strategy for drivers to reduce gasoline consumption and greenhouse gas (GHG) emissions. Ecodriving is gaini...

Experimental study of the effects of flameholder geometry on emissions and performance of lean premixed combustors

NASA Technical Reports Server (NTRS)

Roffe, G.; Venkataramani, K. S.

1978-01-01

Emissions of NOx, CO, and unburned hydrocarbons (UHC) are reported for a lean premixed propane-air system at inlet conditions of 800K and 1MPa using twelve flameholder designs. The flameholders tested represent six design concepts with two values of blockage for each concept. Data were obtained at reference velocities of 35 m/s, 25 m/s and 20 m/s at combustor stations 10 cm and 30 cm downstream of the flameholders. Flameholder pressure drop was found to be a principal determinant of emissions performance. Designs producing larger pressure drops also produced less NOx, CO, and UHC emissions. The lean stability limit equivalence ratio was found to be approximately 0.35 for all designs. Flashback velocities (axial components in the flameholder passages) varied between 30 m/s and 40 m/s. A perforated plate flameholder was operated with a velocity as low as 23 m/s through the perforations at equivalence ratio 0.7 without producing flashback.

Concept of a charged fusion product diagnostic for NSTX.

PubMed

Boeglin, W U; Valenzuela Perez, R; Darrow, D S

2010-10-01

The concept of a new diagnostic for NSTX to determine the time dependent charged fusion product emission profile using an array of semiconductor detectors is presented. The expected time resolution of 1-2 ms should make it possible to study the effect of magnetohydrodynamics and other plasma activities (toroidal Alfvén eigenmodes (TAE), neoclassical tearing modes (NTM), edge localized modes (ELM), etc.) on the radial transport of neutral beam ions. First simulation results of deuterium-deuterium (DD) fusion proton yields for different detector arrangements and methods for inverting the simulated data to obtain the emission profile are discussed.

Optical Johnson noise thermometry

NASA Technical Reports Server (NTRS)

Shepard, R. L.; Blalock, T. V.; Maxey, L. C.; Roberts, M. J.; Simpson, M. L.

1989-01-01

A concept is being explored that an optical analog of the electrical Johnson noise may be used to measure temperature independently of emissivity. The concept is that a laser beam may be modulated on reflection from a hot surface by interaction of the laser photons with the thermally agitated conduction electrons or the lattice phonons, thereby adding noise to the reflected laser beam. If the reflectance noise can be detected and quantified in a background of other noise in the optical and signal processing systems, the reflectance noise may provide a noncontact measurement of the absolute surface temperature and may be independent of the surface's emissivity.

A dual-mode textile for human body radiative heating and cooling

DOE PAGES

Hsu, Po -Chun; Liu, Chong; Song, Alex Y.; ...

2017-11-10

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textilemore » without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. As a result, numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.« less

Technological, Economic, and Environmental Optimization of Aluminum Recycling

NASA Astrophysics Data System (ADS)

Ioana, Adrian; Semenescu, Augustin

2013-08-01

The four strategic directions (referring to the entire life cycle of aluminum) are as follows: production, primary use, recycling, and reuse. Thus, in this work, the following are analyzed and optimized: reducing greenhouse gas emissions from aluminum production, increasing energy efficiency in aluminum production, maximizing used-product collection, recycling, and reusing. According to the energetic balance at the gaseous environment level, the conductive transfer model is also analyzed through the finished elements method. Several principles of modeling and optimization are presented and analyzed: the principle of analogy, the principle of concepts, and the principle of hierarchization. Based on these principles, an original diagram model is designed together with the corresponding logic diagram. This article also presents and analyzes the main benefits of aluminum recycling and reuse. Recycling and reuse of aluminum have the main advantage that it requires only about 5% of energy consumed to produce it from bauxite. The aluminum recycling and production process causes the emission of pollutants such as dioxides and furans, hydrogen chloride, and particulate matter. To control these emissions, aluminum recyclers are required to comply with the National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production. The results of technological, economic, and ecological optimization of aluminum recycling are based on the criteria function's evaluation in the modeling system.

A dual-mode textile for human body radiative heating and cooling

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

Hsu, Po -Chun; Liu, Chong; Song, Alex Y.

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textilemore » without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. As a result, numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.« less

A dual-mode textile for human body radiative heating and cooling

PubMed Central

Hsu, Po-Chun; Liu, Chong; Song, Alex Y.; Zhang, Ze; Peng, Yucan; Xie, Jin; Liu, Kai; Wu, Chun-Lan; Catrysse, Peter B.; Cai, Lili; Zhai, Shang; Majumdar, Arun; Fan, Shanhui; Cui, Yi

2017-01-01

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textile without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. Numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast. PMID:29296678

Novel Active Combustion Control Valve

NASA Technical Reports Server (NTRS)

Caspermeyer, Matt

2014-01-01

This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

Fiber optic system for deflection and damage detection in morphing wing structures

NASA Astrophysics Data System (ADS)

Scheerer, M.; Djinovic, Z.; Schüller, M.

2013-04-01

Within the EC Clean Sky - Smart Fixed Wing Aircraft initiative concepts for actuating morphing wing structures are under development. In order for developing a complete integrated system including the actuation, the structure to be actuated and the closed loop control unit a hybrid deflection and damage monitoring system is required. The aim of the project "FOS3D" is to develop and validate a fiber optic sensing system based on low-coherence interferometry for simultaneous deflection and damage monitoring. The proposed system uses several distributed and multiplexed fiber optic Michelson interferometers to monitor the strain distribution over the actuated part. In addition the same sensor principle will be used to acquire and locate the acoustic emission signals originated from the onset and growth of defects like impact damages, cracks and delamination's. Within this paper the authors present the concept, analyses and first experimental results of the mentioned system.

Operation of the NETL Chemical Looping Reactor with Natural Gas and a Novel Copper-Iron Material

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

Straub, Douglas; Bayham, Samuel; Weber, Justin

The proposed Clean Power Plan requires CO 2 emission reductions of 30% by 2030 and further reductions are targeted by 2050. The current strategies to achieve the 30% reduction targets do not include options for coal. However, the 2016 Annual Energy Outlook suggests that coal will continue to provide more electricity than renewable sources for many regions of the country in 2035. Therefore, cost effective options to reduce greenhouse gas emissions from fossil fuel power plants are vital in order to achieve greenhouse gas reduction targets beyond 2030. As part of the U.S. Department of Energy’s Advanced Combustion Program, themore » National Energy Technology Laboratory’s Research and Innovation Center (NETL R&IC) is investigating the feasibility of a novel combustion concept in which the GHG emissions can be significantly reduced. This concept involves burning fuel and air without mixing these two reactants. If this concept is technically feasible, then CO 2 emissions can be significantly reduced at a much lower cost than more conventional approaches. This indirect combustion concept has been called Chemical Looping Combustion (CLC) because an intermediate material (i.e., a metal-oxide) is continuously cycled to oxidize the fuel. This CLC concept is the focus of this research and will be described in more detail in the following sections. The solid material that is used to transport oxygen is called an oxygen carrier material. The cost, durability, and performance of this material is a key issue for the CLC technology. Researchers at the NETL R&IC have developed an oxygen carrier material that consists of copper, iron, and alumina. This material has been tested extensively using lab scale instruments such as thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mechanical attrition (ASTM D5757), and small fluidized bed reactor tests. This report will describe the results from a realistic, circulating, proof-of-concept test that was completed using NETL’s 50kW th circulating Chemical Looping Reactor (CLR) test facility.« less

Micropillars with a controlled number of site-controlled quantum dots

NASA Astrophysics Data System (ADS)

Kaganskiy, Arsenty; Gericke, Fabian; Heuser, Tobias; Heindel, Tobias; Porte, Xavier; Reitzenstein, Stephan

2018-02-01

We report on the realization of micropillars with site-controlled quantum dots (SCQDs) in the active layer. The SCQDs are grown via the buried stressor approach which allows for the positioned growth and device integration of a controllable number of QDs with high optical quality. This concept is very powerful as the number and the position of SCQDs in the cavity can be simultaneously controlled by the design of the buried-stressor. The fabricated micropillars exhibit a high degree of position control for the QDs above the buried stressor and Q-factors of up to 12 000 at an emission wavelength of around 930 nm. We experimentally analyze and numerically model the cavity Q-factor, the mode volume, the Purcell factor, and the photon-extraction efficiency as a function of the aperture diameter of the buried stressor. Exploiting these SCQD micropillars, we experimentally observe a Purcell enhancement in the single-QD regime with FP = 4.3 ± 0.3.

Brain and Language.

ERIC Educational Resources Information Center

Damasio, Antonio R., Damasio, Hanna

1992-01-01

Discusses the advances made in understanding the brain structures responsible for language. Presents findings made using magnetic resonance imaging (MRI) and positron emission tomographic (PET) scans to study brain activity. These findings map the structures in the brain that manipulate concepts and those that turn concepts into words. (MCO)

USER'S GUIDE: EMISSION CONTROL TECHNOLOGIES AND EMISSION FACTORS FOR UNPAVED ROAD FUGITIVE EMISSIONS

EPA Science Inventory

This document assists control agency personnel in evaluating unpaved road fugitive emissions control plans and helps industry personnel develop effective control strategies for unpaved roads. he brochure describes control techniques for reducing unpaved road emissions and methods...

40 CFR 86.1803-01 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Auxiliary Emission Control Device (AECD) means any element of design which senses temperature, vehicle speed.... Critical emission-related components are those components which are designed primarily for emission control... control system is a unique group of emission control devices, auxiliary emission control devices, engine...

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

Dowdy, M.; Burke, A.; Schneider, H.

Fuel economy, exhaust emissions, multifuel capability, advanced materials and cost/manufacturability for both conventional and advanced alternative power systems were assessed. To insure valid comparisons of vehicles with alternative power systems, the concept of an Otto-Engine-Equivalent (OEE) vehicle was utilized. Each engine type was sized to provide equivalent vehicle performance. Sensitivity to different performance criteria was evaluated. Fuel economy projections are made for each engine type considering both the legislated emission standards and possible future emissions requirements.

Applied analytical combustion/emissions research at the NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

1992-01-01

Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

Applied Analytical Combustion/emissions Research at the NASA Lewis Research Center - a Progress Report

NASA Technical Reports Server (NTRS)

Deur, J. M.; Kundu, K. P.; Nguyen, H. L.

1992-01-01

Emissions of pollutants from future commercial transports are a significant concern. As a result, the Lewis Research Center (LeRC) is investigating various low emission combustor technologies. As part of this effort, a combustor analysis code development program was pursued to guide the combustor design process, to identify concepts having the greatest promise, and to optimize them at the lowest cost in the minimum time.

Density functional theory for field emission from carbon nano-structures.

PubMed

Li, Zhibing

2015-12-01

Electron field emission is understood as a quantum mechanical many-body problem in which an electronic quasi-particle of the emitter is converted into an electron in vacuum. Fundamental concepts of field emission, such as the field enhancement factor, work-function, edge barrier and emission current density, will be investigated, using carbon nanotubes and graphene as examples. A multi-scale algorithm basing on density functional theory is introduced. We will argue that such a first principle approach is necessary and appropriate for field emission of nano-structures, not only for a more accurate quantitative description, but, more importantly, for deeper insight into field emission. Copyright © 2015 The Author. Published by Elsevier B.V. All rights reserved.

Experimental Assessment of the Emissions Control Potential of a Rich/Quench/Lean Combustor for High Speed Civil Transport Aircraft Engines

NASA Technical Reports Server (NTRS)

Rosfjord, T. J.; Padget, F. C.; Tacina, Robert R. (Technical Monitor)

2001-01-01

In support of Pratt & Whitney efforts to define the Rich burn/Quick mix/Lean burn (RQL) combustor for the High Speed Civil Transport (HSCT) aircraft engine, UTRC conducted a flametube-scale study of the RQL concept. Extensive combustor testing was performed at the Supersonic Cruise (SSC) condition of a HSCT engine cycle, Data obtained from probe traverses near the exit of the mixing section confirmed that the mixing section was the critical component in controlling combustor emissions. Circular-hole configurations, which produced rapidly-, highly-penetrating jets, were most effective in limiting NOx. The spatial profiles of NOx and CO at the mixer exit were not directly interpretable using a simple flow model based on jet penetration, and a greater understanding of the flow and chemical processes in this section are required to optimize it. Neither the rich-combustor equivalence ratio nor its residence time was a direct contributor to the exit NOx. Based on this study, it was also concluded that (1) While NOx formation in both the mixing section and the lean combustor contribute to the overall emission, the NOx formation in the mixing section dominates. The gas composition exiting the rich combustor can be reasonably represented by the equilibrium composition corresponding to the rich combustor operating condition. Negligible NOx exits the rich combustor. (2) At the SSC condition, the oxidation processes occurring in the mixing section consume 99 percent of the CO exiting the rich combustor. Soot formed in the rich combustor is also highly oxidized, with combustor exit SAE Smoke Number <3. (3) Mixing section configurations which demonstrated enhanced emissions control at SSC also performed better at part-power conditions. Data from mixer exit traverses reflected the expected mixing behavior for off-design jet to crossflow momentum-flux ratios. (4) Low power operating conditions require that the RQL combustor operate as a lean-lean combustor to achieve low CO and high efficiency. (5) A RQL combustor can achieve the emissions goal of EINOX = 5 at the Supersonic Cruise operating condition for a HSCT engine.

Experimental Assessment of the Emissions Control Potential of a Rich/Quench/ Lean Combustor for High Speed Civil Transport Aircraft Engines

NASA Technical Reports Server (NTRS)

Tacina, Robert R. (Technical Monitor); Rosfjord, T. J.; Padget, F. C.

2001-01-01

In support of Pratt & Whitney efforts to define the Rich burn/Quick mix/Lean burn (RQL) combustor for the High Speed Civil Transport (HSCT) aircraft engine, UTRC conducted a flametube-scale study of the RQL concept. Extensive combustor testing was performed at the Supersonic Cruise (SSC) condition of an HSCT engine cycle. Data obtained from probe traverses near the exit of the mixing section confirmed that the mixing section was the critical component in controlling combustor emissions. Circular-hole configurations, which produced rapidly-, highly-penetrating jets, were most effective in limiting NO(x). The spatial profiles of NO(x) and CO at the mixer exit were not directly interpretable using a simple flow model based on jet penetration, and a greater understanding of the flow and chemical processes in this section are required to optimize it. Neither the rich-combustor equivalence ratio nor its residence time was a direct contributor to the exit NO(x). Based on this study, it was also concluded that: (1) While NO(x) formation in both the mixing section and the lean combustor contribute to the overall emission, the NOx formation in the mixing section dominates. The gas composition exiting the rich combustor can be reasonably represented by the equilibrium composition corresponding to the rich combustor operating condition. Negligible NO(x) exits the rich combustor. (2) At the SSC condition, the oxidation processes occurring in the mixing section consume 99 percent of the CO exiting the rich combustor. Soot formed in the rich combustor is also highly oxidized, with combustor exit SAE Smoke Number <3. (3) Mixing section configurations which demonstrated enhanced emissions control at SSC also performed better at part-power conditions. Data from mixer exit traverses reflected the expected mixing behavior for off-design jet to crossflow momentum-flux ratios. (4) Low power operating conditions require that the RQL combustor operate as a lean-lean combustor to achieve low CO and high efficiency. (5) An RQL combustor can achieve the emissions goal of EINO(x) = 5 at the Supersonic Cruise operating condition for an HSCT engine.

Analysis of Lean Premixed/Prevaporized Combustion with KIVA-2

NASA Technical Reports Server (NTRS)

Deur, J. M.; Kundu, K. P.; Darling, D. D.; Cline, M. C.; Micklow, G. J.; Harper, M. R.; Simons, T. A.

1994-01-01

Requirements to reduce the emissions of pollutants from gas turbines used in aircraft propulsion and ground based power generation have led to consideration of lean premixed/prevaporized (LPP) combustion concept. This paper describes some of the LPP flame tube analyses performed at the NASA Research Center with KIVA-2, a well-known multi-dimensional CFD code for problems including sprays, turbulence, and combustion. Modifications to KIVA-2's boundary condition and chemistry treatments have been made to meet the needs of the present study. The study itself focuses on two key aspects of the LPP concept, low emissions and flame stability (including flashback and lean blowoff.

The 1990 high-speed civil transport studies. Summary report

NASA Technical Reports Server (NTRS)

1992-01-01

This report contains the results of the Douglas Aircraft Company system studies related to High-Speed Civil Transports (HSCT's). The tasks were performed under an 18-month extension of NASA Langley Research Center Contract NAS1-18378. The system studies were conducted to assess the emission impact of HSCT's at design Mach numbers ranging from 1.6 to 3.2. In particular, engine cycles were assessed regarding community noise and atmospheric emissions impact, and a HSCT route structure was developed. The general results indicated the following: (1) in the Mach number range 1.6 to 2.5, the development of polymer composite and discontinuous reinforced alumnium materials is essential to ensure a minimum operational weight; (2) the HSCT route structure to minimize supersonic overland can be increased by innovative routing to avoid land masses; (3) at least two engine concepts show promise in achieving sideline stage 3 noise limits; (4) two promising low-NO(x) combustor concepts were identified; (5) the atmospheric emission impact on ozone could be significantly lower for Mach 1.6 operations than for Mach 3.2 operations; and (6) sonic boom minimization concepts are maturing at an encouraging rate.

Pollution technology program, can-annular combustor engines

NASA Technical Reports Server (NTRS)

Roberts, R.; Fiorentino, A. J.; Greene, W.

1976-01-01

A Pollution Reduction Technology Program to develop and demonstrate the combustor technology necessary to reduce exhaust emissions for aircraft engines using can-annular combustors is described. The program consisted of design, fabrication, experimental rig testing and assessment of results and was conducted in three program elements. The combustor configurations of each program element represented increasing potential for meeting the 1979 Environmental Protection Agency (EPA) emission standards, while also representing increasing complexity and difficulty of development and adaptation to an operational engine. Experimental test rig results indicate that significant reductions were made to the emission levels of the baseline JT8D-17 combustor by concepts in all three program elements. One of the Element I single-stage combustors reduced carbon monoxide to a level near, and total unburned hydrocarbons (THC) and smoke to levels below the 1979 EPA standards with little or no improvement in oxides of nitrogen. The Element II two-stage advanced Vorbix (vortex burning and mixing) concept met the standard for THC and achieved significant reductions in CO and NOx relative to the baseline. Although the Element III prevaporized-premixed concept reduced high power NOx below the Element II results, there was no improvement to the integrated EPA parameter relative to the Vorbix combustor.

DELTA-DIESEL ENGINE LIGHT TRUCK APPLICATION Contract DE-FC05-97OR22606 Final Report

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

Hakim, Nabil Balnaves, Mike

2003-05-27

DELTA Diesel Engine Light Truck Application End of Contract Report DE-FC05-97-OR22606 EXECUTIVE SUMMARY This report is the final technical report of the Diesel Engine Light Truck Application (DELTA) program under contract DE-FC05-97-OR22606. During the course of this contract, Detroit Diesel Corporation analyzed, designed, tooled, developed and applied the ''Proof of Concept'' (Generation 0) 4.0L V-6 DELTA engine and designed the successor ''Production Technology Demonstration'' (Generation 1) 4.0L V-6 DELTA engine. The objectives of DELTA Program contract DE-FC05-97-OR22606 were to: Demonstrate production-viable diesel engine technologies, specifically intended for the North American LDT and SUV markets; Demonstrate emissions compliance with significant fuelmore » economy advantages. With a clean sheet design, DDC produced the DELTA engine concept promising the following attributes: 30-50% improved fuel economy; Low cost; Good durability and reliability; Acceptable noise, vibration and harshness (NVH); State-of-the-art features; Even firing, 4 valves per cylinder; High pressure common rail fuel system; Electronically controlled; Turbocharged, intercooled, cooled EGR; Extremely low emissions via CLEAN Combustion{copyright} technology. To demonstrate the engine technology in the SUV market, DDC repowered a 1999 Dodge Durango with the DELTA Generation 0 engine. Fuel economy improvements were approximately 50% better than the gasoline engine replaced in the vehicle.« less

Monolayer Transition Metal Dichalcogenides as Light Sources.

PubMed

Pu, Jiang; Takenobu, Taishi

2018-06-13

Reducing the dimensions of materials is one of the key approaches to discovering novel optical phenomena. The recent emergence of 2D transition metal dichalcogenides (TMDCs) has provided a promising platform for exploring new optoelectronic device applications, with their tunable electronic properties, structural controllability, and unique spin valley-coupled systems. This progress report provides an overview of recent advances in TMDC-based light-emitting devices discussed from several aspects in terms of device concepts, material designs, device fabrication, and their diverse functionalities. First, the advantages of TMDCs used in light-emitting devices and their possible functionalities are presented. Second, conventional approaches for fabricating TMDC light-emitting devices are emphasized, followed by introducing a newly established, versatile method for generating light emission in TMDCs. Third, current growing technologies for heterostructure fabrication, in which distinct TMDCs are vertically stacked or laterally stitched, are explained as a possible means for designing high-performance light-emitting devices. Finally, utilizing the topological features of TMDCs, the challenges for controlling circularly polarized light emission and its device applications are discussed from both theoretical and experimental points of view. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical chopper for the HIRDLS instrument

NASA Astrophysics Data System (ADS)

Opyd, Walter G.; Rudolf, Wayne; Loewenthal, Stuart; Heal, Thomas

1998-11-01

Test chipper performance, as well as mechanical design and electronic control concepts, are presented for the optical chopper developed for the High-Resolution Dynamics Limb Sounder (HIRDLS) to be flown on the CHEM-1 satellite of the NASA Earth Observing System (EOS). Optical chopping is essential in order to achieve the required sensitivity and accuracy in measurement of infrared emission from various chemical species in the earth's atmosphere. Chopping of the optical input as far forward in the telescope as practical minimizes calibration errors arising from variations in emission from warm optics and due to electronic drifts in the infrared detecting system. At 500 Hz, the reflective chopper blade switches between the atmospheric limb view and reference radiation from cold space. The HIRDLS chopper is a six- toothed, mirrored wheel driven by a three-phase, permanent- magnet, brushless DC motor with trapezoidal excitation synchronized to motor back-emf. Chopper design was driven by requirements of (1) continuous operation at 5000 RPM for 50,000 hours in space vacuum, (2) chopping amplitude stability of one part in 100,000, (3) lubricant loss control for both bearing reliability and prevention of optics contamination, (4) compact size to fit in the folded telescope, and (5) survival in the launch environment.

Automation for Accommodating Fuel-Efficient Descents in Constrained Airspace

NASA Technical Reports Server (NTRS)

Coopenbarger, Richard A.

2010-01-01

Continuous descents at low engine power are desired to reduce fuel consumption, emissions and noise during arrival operations. The challenge is to allow airplanes to fly these types of efficient descents without interruption during busy traffic conditions. During busy conditions today, airplanes are commonly forced to fly inefficient, step-down descents as airtraffic controllers work to ensure separation and maximize throughput. NASA in collaboration with government and industry partners is developing new automation to help controllers accommodate continuous descents in the presence of complex traffic and airspace constraints. This automation relies on accurate trajectory predictions to compute strategic maneuver advisories. The talk will describe the concept behind this new automation and provide an overview of the simulations and flight testing used to develop and refine its underlying technology.

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

Attig, R.C.; Crawford, L.W.; Lynch, T.P.

Proof-of-Concept (POC) scale demonstration of such technology is currently being carried out at the US Department of Energy's (DOE's) Coal-Fired Flow Facility (CFFF), located at The University of Tennessee Space Institute (UTSI) in Tullahoma, Tennessee and at the Component Development and Integration Facility in Butte, Montana. The CFFF is dedicated to the evaluation of downstream (steam cycle) components and technology that may be considered for a full-scale MHD system. The objectives of the CFFF testing include the demonstration of various pollution control devices and techniques at a scale sufficient for future scale-up. The CFFF offers a unique test environment inmore » which emissions control techniques can be developed and evaluated through emissions and environmental monitoring. Results thus far have demonstrated the ability of sulfur oxide (SO{sub x}), nitrogen oxide (NO{sub x}) and particulate emissions well below the New Source Performance Standards (NSPS). Regeneration of the potassium sulfate to produce sulfur-free compounds also has been demonstrated. The experimental program at the CFFF is now aimed at determining the optimum conditions for future commercial scale designs. Because of increased interests in Air Toxics, measurements of nitrous oxide (N{sub 2}O), a potential greenhouse gas, priority pollutants (inorganic as well as organics), and chlorine-containing species (Cl{sub 2} and HCl) are also included in our ongoing efforts. Environmental monitoring activities are being pursued to develop an environmental impact assessment data base. These include the use of three ambient air sites to determine the impacts of gaseous and particulate emissions, five lake water sites to determine impacts due to process water discharges and seven sites to collect terrestrial data on possible soil contamination and tree growth. In this paper, we will summarize the status of our ongoing environmental program. 16 refs., 15 figs., 3 tabs.« less

Polarization-controlled directional scattering for nanoscopic position sensing

PubMed Central

Neugebauer, Martin; Woźniak, Paweł; Bag, Ankan; Leuchs, Gerd; Banzer, Peter

2016-01-01

Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has been directed towards high-refractive-index materials such as silicon as an integral part of the antenna design. This development is motivated by the rich spectral properties of individual high-refractive-index nanoparticles. Here we take advantage of the interference of their magnetic and electric resonances to achieve strong lateral directionality. For controlled excitation of a spherical silicon nanoantenna, we use tightly focused radially polarized light. The resultant directional emission depends on the antenna's position relative to the focus. This approach finds application as a novel position sensing technique, which might be implemented in modern nanometrology and super-resolution microscopy set-ups. We demonstrate in a proof-of-concept experiment that a lateral resolution in the Ångström regime can be achieved. PMID:27095171

40 CFR 63.652 - Emissions averaging provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

40 CFR 63.652 - Emissions averaging provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

INNOVATIVE CONCEPTS FOR DETECTING AND LOCATING LEAKS IN WASTE IMPOUNDMENT LINER SYSTEMS: ACOUSTIC EMISSION MONITORING AND TIME DOMAIN REFLECTOMETRY

EPA Science Inventory

This project is part of a program to investigate the use of innovative techniques for detecting and locating leaks in waste impoundment liners. Laboratory and small scale field studies were undertaken to evaluate the potential of Acoustic Emission Monitoring (AEM) and Time Domain...

New approaches for automatic threedimensional source localization of acoustic emissions--Applications to concrete specimens.

PubMed

Kurz, Jochen H

2015-12-01

The task of locating a source in space by measuring travel time differences of elastic or electromagnetic waves from the source to several sensors is evident in varying fields. The new concepts of automatic acoustic emission localization presented in this article are based on developments from geodesy and seismology. A detailed description of source location determination in space is given with the focus on acoustic emission data from concrete specimens. Direct and iterative solvers are compared. A concept based on direct solvers from geodesy extended by a statistical approach is described which allows a stable source location determination even for partly erroneous onset times. The developed approach is validated with acoustic emission data from a large specimen leading to travel paths up to 1m and therefore to noisy data with errors in the determined onsets. The adaption of the algorithms from geodesy to the localization procedure of sources of elastic waves offers new possibilities concerning stability, automation and performance of localization results. Fracture processes can be assessed more accurately. Copyright © 2015 Elsevier B.V. All rights reserved.

LAMP: a micro-satellite based soft x-ray polarimeter for astrophysics

NASA Astrophysics Data System (ADS)

She, Rui; Feng, Hua; Muleri, Fabio; Soffitta, Paolo; Xu, Renxin; Li, Hong; Bellazzini, Ronaldo; Wang, Zhanshan; Spiga, Daniele; Minuti, Massimo; Brez, Alessandro; Spandre, Gloria; Pinchera, Michele; Sgrò, Carmelo; Baldini, Luca; Wen, Mingwu; Shen, Zhengxiang; Pareschi, Giovanni; Tagliaferri, Gianpiero; Tayabaly, Kashmira; Salmaso, Bianca; Zhan, Yafeng

2015-08-01

The Lightweight Asymmetry and Magnetism Probe (LAMP) is a micro-satellite mission concept dedicated for astronomical X-ray polarimetry and is currently under early phase study. It consists of segmented paraboloidal multilayer mirrors with a collecting area of about 1300 cm2 to reflect and focus 250 eV X-rays, which will be detected by position sensitive detectors at the focal plane. The primary targets of LAMP include the thermal emission from the surface of pulsars and synchrotron emission produced by relativistic jets in blazars. With the expected sensitivity, it will allow us to detect polarization or place a tight upper limit for about 10 pulsars and 20 blazars. In addition to measuring magnetic structures in these objects, LAMP will also enable us to discover bare quark stars if they exist, whose thermal emission is expected to be zero polarized, while the thermal emission from neutron stars is believed to be highly polarized due to plasma polarization and the quantum electrodynamics (QED) effect. Here we present an overview of the mission concept, its science objectives and simulated observational results.

The experimental clean combustor program: Description and status to November 1975

NASA Technical Reports Server (NTRS)

Niedzwiecki, R. W.

1975-01-01

The generation of technology was studied for the development of advanced commercial CTOL aircraft engines with lower exhaust emissions than current aircraft. The program is in three phases. Phase 1, already completed, consisted of screening tests of low pollution combustor concepts. Phase 2, currently in progress, consists of test rig refinement of the most promising combustor concepts. Phase 2 test results are reported. Phase 3, also currently in progress, consists of incorporating and evaluating the best combustors as part of a complete engine. Engine test plans and pollution sampling techniques are described in this report. Program pollution goals, specified at engine idle and take-off conditions, are idle emission index value of 20 and 4 for carbon monoxide (CO) and total unburned hydrocarbons (THC), respectively, and at take-off are an oxides of nitrogen (NOx) emission index level of 10 and a smoke number of 15. Pollution data were obtained at all engine operating conditions. Results are presented in terms of emission index and also in terms of the Environmental Protection Agency's 1979 Standards Parameter.

Low NOx heavy fuel combustor concept program. Phase 1: Combustion technology generation

NASA Astrophysics Data System (ADS)

Lew, H. G.; Carl, D. R.; Vermes, G.; Dezubay, E. A.; Schwab, J. A.; Prothroe, D.

1981-10-01

The viability of low emission nitrogen oxide (NOx) gas turbine combustors for industrial and utility application. Thirteen different concepts were evolved and most were tested. Acceptable performance was demonstrated for four of the combustors using ERBS fuel and ultralow NOx emissions were obtained for lean catalytic combustion. Residual oil and coal derived liquids containing fuel bound nitrogen (FBN) were also used at test fuels, and it was shown that staged rich/lean combustion was effective in minimizing the conversion of FBN to NOx. The rich/lean concept was tested with both modular and integral combustors. While the ceramic lined modular configuration produced the best results, the advantages of the all metal integral burners make them candidates for future development. An example of scaling the laboratory sized combustor to a 100 MW size engine is included in the report as are recommendations for future work.

Low NOx heavy fuel combustor concept program. Phase 1: Combustion technology generation

NASA Technical Reports Server (NTRS)

Lew, H. G.; Carl, D. R.; Vermes, G.; Dezubay, E. A.; Schwab, J. A.; Prothroe, D.

1981-01-01

The viability of low emission nitrogen oxide (NOx) gas turbine combustors for industrial and utility application. Thirteen different concepts were evolved and most were tested. Acceptable performance was demonstrated for four of the combustors using ERBS fuel and ultralow NOx emissions were obtained for lean catalytic combustion. Residual oil and coal derived liquids containing fuel bound nitrogen (FBN) were also used at test fuels, and it was shown that staged rich/lean combustion was effective in minimizing the conversion of FBN to NOx. The rich/lean concept was tested with both modular and integral combustors. While the ceramic lined modular configuration produced the best results, the advantages of the all metal integral burners make them candidates for future development. An example of scaling the laboratory sized combustor to a 100 MW size engine is included in the report as are recommendations for future work.

Fuel Flexible Gas Turbine Combustor Flametube Facility Upgraded

NASA Technical Reports Server (NTRS)

Little, James E.; Nemets, Steve A.; Tornabene, Robert T.; Smith, Timothy D.; Frankenfeld, Bruce J.

2004-01-01

In fiscal year 2003, test cell 23 of the Research Combustion Laboratory (RCL 23) at the NASA Glenn Research Center was upgraded with the addition of gaseous hydrogen as a working propellant and the addition of a 450-psig air-supply system. Test flexibility was further enhanced by upgrades to the facility control systems. RCL 23 can now test with gaseous hydrogen flow rates up to 0.05 lbm/sec and jet fuel flow rates up to 0.62 lbm/sec. Research airflow rates up to 3 lbm/sec are possible with the 450-psig supply system over a range of inlet temperatures. Nonvitiated, heated air is supplied from a shell and tube heat exchanger. The maximum nonvitiated facility air temperature is 1100 F at 1.5 lbm/sec. Research-section exhaust temperatures are limited to 3200 F because of material and cooling capacity limits. A variety of support systems are available depending on the research hardware configuration. Test section ignition can be provided via either a hydrogen air torch system or an electronic spark system. Emissions measurements are obtained with either pneumatically or electromechanically actuated gas sample probes, and the electromechanical system allows for radial measurements at a user-specified axial location for measurement of emissions profiles. Gas analysis data can be obtained for a variety of species, including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NO and NOx), oxygen (O2), unburnt hydrocarbons, and unburnt hydrogen. Facility control is accomplished with a programmable logic control system. Facility operations have been upgraded to a system based on graphical user interface control screens. A data system is available for real-time acquisition and monitoring of both measurements in engineering units and performance calculations. The upgrades have made RCL 23 a highly flexible facility for research into low emissions gas turbine combustor concepts, and the flame tube configuration inherently allows for a variety of fuel nozzle configurations to be tested in a cost-effective manner. RCL 23 is poised to be a leading facility for developing modern low-emission fuel nozzles for use with jet fuel and alternative fuels.

Environmental impact analysis with the airspace concept evaluation system

NASA Technical Reports Server (NTRS)

Augustine, Stephen; Capozzi, Brian; DiFelici, John; Graham, Michael; Thompson, Terry; Miraflor, Raymond M. C.

2005-01-01

The National Aeronautics and Space Administration (NASA) Ames Research Center has developed the Airspace Concept Evaluation System (ACES), which is a fast-time simulation tool for evaluating Air Traffic Management (ATM) systems. This paper describes linking a capability to ACES which can analyze the environmental impact of proposed future ATM systems. This provides the ability to quickly evaluate metrics associated with environmental impacts of aviation for inclusion in multi-dimensional cost-benefit analysis of concepts for evolution of the National Airspace System (NAS) over the next several decades. The methodology used here may be summarized as follows: 1) Standard Federal Aviation Administration (FAA) noise and emissions-inventory models, the Noise Impact Routing System (NIRS) and the Emissions and Dispersion Modeling System (EDMS), respectively, are linked to ACES simulation outputs; 2) appropriate modifications are made to ACES outputs to incorporate all information needed by the environmental models (e.g., specific airframe and engine data); 3) noise and emissions calculations are performed for all traffic and airports in the study area for each of several scenarios, as simulated by ACES; and 4) impacts of future scenarios are compared to the current NAS baseline scenario. This paper also provides the results of initial end-to-end, proof-of-concept runs of the integrated ACES and environmental-modeling capability. These preliminary results demonstrate that if no growth is likely to be impeded by significant environmental impacts that could negatively affect communities throughout the nation.

Passive SCR for lean gasoline NO X control: Engine-based strategies to minimize fuel penalty associated with catalytic NH 3 generation

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

Prikhodko, Vitaly Y.; Parks, James E.; Pihl, Josh A.

Lean gasoline engines offer greater fuel economy than common stoichiometric gasoline engines. However, excess oxygen prevents the use of the current three-way catalyst (TWC) to control nitrogen oxide (NO X) emissions in lean exhaust. A passive SCR concept, introduced by General Motors Global R&D, makes use of a TWC that is already onboard to generate NH 3 under slightly rich conditions, which is stored on the downstream SCR. The stored NH 3 is then used to reduce NO X emissions when the engine switches to lean operation. In this work, the effect of engine parameters, such as air-fuel equivalence ratiomore » and spark timing, on NH 3 generation over a commercial Pd-only TWC with no dedicated oxygen storage component was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine. NO X reduction, NH 3 formation, and reductant utilization processes were evaluated, and fuel efficiency was assessed and compared to the stoichiometric engine operation case. We found air-fuel equivalence ratio to be one of the most important parameters in controlling the NH 3 production; however, the rich operation necessary for NH 3 production results in a fuel consumption penalty. The fuel penalty can be minimized by adjusting spark timing to increase rich-phase engine out NO X emissions and, thereby, NH 3 levels. Additionally, higher engine out NO X during engine load increase to simulate acceleration resulted in additional fuel savings. Ultimately, a 10% fuel consumption benefit was achieved with the passive SCR approach by optimizing rich air-fuel equivalence ratio and spark timing while also utilizing acceleration load conditions.« less

Passive SCR for lean gasoline NO X control: Engine-based strategies to minimize fuel penalty associated with catalytic NH 3 generation

DOE PAGES

Prikhodko, Vitaly Y.; Parks, James E.; Pihl, Josh A.; ...

2016-02-18

Lean gasoline engines offer greater fuel economy than common stoichiometric gasoline engines. However, excess oxygen prevents the use of the current three-way catalyst (TWC) to control nitrogen oxide (NO X) emissions in lean exhaust. A passive SCR concept, introduced by General Motors Global R&D, makes use of a TWC that is already onboard to generate NH 3 under slightly rich conditions, which is stored on the downstream SCR. The stored NH 3 is then used to reduce NO X emissions when the engine switches to lean operation. In this work, the effect of engine parameters, such as air-fuel equivalence ratiomore » and spark timing, on NH 3 generation over a commercial Pd-only TWC with no dedicated oxygen storage component was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine. NO X reduction, NH 3 formation, and reductant utilization processes were evaluated, and fuel efficiency was assessed and compared to the stoichiometric engine operation case. We found air-fuel equivalence ratio to be one of the most important parameters in controlling the NH 3 production; however, the rich operation necessary for NH 3 production results in a fuel consumption penalty. The fuel penalty can be minimized by adjusting spark timing to increase rich-phase engine out NO X emissions and, thereby, NH 3 levels. Additionally, higher engine out NO X during engine load increase to simulate acceleration resulted in additional fuel savings. Ultimately, a 10% fuel consumption benefit was achieved with the passive SCR approach by optimizing rich air-fuel equivalence ratio and spark timing while also utilizing acceleration load conditions.« less

Investigation of continuous changes in the electric-field-induced electronic state in Bi(1-x)Ca(x)FeO(3-δ).

PubMed

Ikeda-Ohno, Atsushi; Lim, Ji Soo; Ohkochi, Takuo; Yang, Chan-Ho; Seidel, Jan

2014-09-07

Amongst the most interesting phenomena in correlated oxide systems are the doping-driven competitions between energetically similar ground states found in, e.g., high-Tc superconductors and colossal magnetoresistance manganites. It has recently been reported that doped multiferroics also exhibit this generic concept of phase competition. Here, we employ photoelectron emission microscopy (PEEM) to demonstrate evidence of systematic changes in the electronic structure of Bi(1-x)Ca(x)FeO(3-δ) treated by electrically controlled hole carrier doping, the outcome of which clearly correlates with the local modulation of electronic conductivity observed in the same material.

Emission characteristics of a premix combustor fueled with a simulated partial-oxidation product gas

NASA Technical Reports Server (NTRS)

Clayton, R. M.

1979-01-01

A two-stage gas turbine combustor concept employing a very fuel-rich partial oxidation stage is being explored for broadening the combustion margin between ultralow emissions and the lean stability limit. Combustion and emission results are presented for a series of experiments where a simulated partial oxidation product gas was used in a premix combustor operated with inlet air state conditions typical of cruise power for high-performance aviation engines (12 atm and 850 F). Ultralow NOx, CO, and HC emissions and an extended lean burning limit were achieved simultaneously.

Assessing GHG emissions, ecological footprint, and water linkage for different fuels.

PubMed

Chavez-Rodriguez, Mauro F; Nebra, Silvia A

2010-12-15

Currently, transport is highly dependent on fossil fuels and responsible for about 23% of world energy-related GHG (greenhouse gas) emissions. Ethanol from sugar cane and corn emerges as an alternative for gasoline in order to mitigate GHG emissions. Additionally, deeper offshore drilling projects such as in the Brazilian Pre-Salt reservoirs and mining projects of nonconventional sources like Tar Sands in Canada could be a solution for supplying demand of fossil fuels in the short and midterm. Based on updated literature, this paper presents an assessment of GHG emissions for four different fuels: ethanol from sugar cane and from corn and gasoline from conventional crude oil and from tar sands. An Ecological Footprint analysis is also presented, which shows that ethanol from sugar cane has the lowest GHG emissions and requires the lowest biocapacity per unit of energy produced among these fuels. Finally, an analysis using the Embodied Water concept is made with the introduction of a new concept, the "CO(2)-Water", to illustrate the impacts of releasing carbon from underground to atmosphere and of the water needed to sequestrate it over the life cycle of the assessed fuels. Using this method resulted that gasoline from fossil fuels would indirectly "require" on average as much water as ethanol from sugar cane per unit of fuel energy produced.

Lean Stability augmentation study

NASA Technical Reports Server (NTRS)

Mcvey, J. B.; Kennedy, J. B.

1979-01-01

An analytical and experimental program was conducted to investigate techniques and develop technology for improving the lean combustion limits of premixing, prevaporizing combustors applicable to gas turbine engine main burners. Three concepts for improving lean stability limits were selected for experimental evaluation among twelve approaches considered. Concepts were selected on the basis of the potential for improving stability limits and achieving emission goals, the technological risks associated with development of practical burners employing the concepts, and the penalties to airline direct operating costs resulting from decreased combustor performance, increased engine cost, increased maintenance cost and increased engine weight associated with implementation of the concepts. Tests of flameholders embodying the selected concepts were conducted.

2003 NASA Seal/Secondary Air System Workshop. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

2004-01-01

The following reports were included in the 2003 NASA Seal/Secondary Air System Workshop:Low Emissions Alternative Power (LEAP); Overview of NASA Glenn Seal Developments; NASA Ultra Efficient Engine Technology Project Overview; Development of Higher Temperature Abradable Seals for Industrial Gas Turbines; High Misalignment Carbon Seals for the Fan Drive Gear System Technologies; Compliant Foil Seal Investigations; Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts; Controls Considerations for Turbine Active Clearance Control; Non-Contacting Finger Seal Developments and Design Considerations; Effect of Flow-Induced Radial Load on Brush Seal/Rotor Contact Mechanics; Seal Developments at Flowserve Corporation; Investigations of High Pressure Acoustic Waves in Resonators With Seal-Like Features; Numerical Investigations of High Pressure Acoustic Waves in Resonators; Feltmetal Seal Material Through-Flow; "Bimodal" Nuclear Thermal Rocket (BNTR) Propulsion for Future Human Mars Exploration Missions; High Temperature Propulsion System Structural Seals for Future Space Launch Vehicles; Advanced Control Surface Seal Development for Future Space Vehicles; High Temperature Metallic Seal Development for Aero Propulsion and Gas Turbine Applications; and BrazeFoil Honeycomb.

Air Breathing Propulsion Controls and Diagnostics Research at NASA Glenn Under NASA Aeronautics Research Mission Programs

NASA Technical Reports Server (NTRS)

Garg, Sanjay

2015-01-01

The Intelligent Control and Autonomy Branch (ICA) at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC) in Cleveland, Ohio, is leading and participating in various projects in partnership with other organizations within GRC and across NASA, the U.S. aerospace industry, and academia to develop advanced controls and health management technologies that will help meet the goals of the NASA Aeronautics Research Mission Directorate (ARMD) Programs. These efforts are primarily under the various projects under the Advanced Air Vehicles Program (AAVP), Airspace Operations and Safety Program (AOSP) and Transformative Aeronautics Concepts Program (TAC). The ICA Branch is focused on advancing the state-of-the-art of aero-engine control and diagnostics technologies to help improve aviation safety, increase efficiency, and enable operation with reduced emissions. This paper describes the various ICA research efforts under the NASA Aeronautics Research Mission Programs with a summary of motivation, background, technical approach, and recent accomplishments for each of the research tasks.

Automotive technology status and projections. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Dowdy, M.; Burke, A.; Schneider, H.; Edmiston, W.; Klose, G. J.; Heft, R.

1978-01-01

Fuel economy, exhaust emissions, multifuel capability, advanced materials and cost/manufacturability for both conventional and advanced alternative power systems were assessed. To insure valid comparisons of vehicles with alternative power systems, the concept of an Otto-Engine-Equivalent (OEE) vehicle was utilized. Each engine type was sized to provide equivalent vehicle performance. Sensitivity to different performance criteria was evaluated. Fuel economy projections are made for each engine type considering both the legislated emission standards and possible future emissions requirements.

Supersonic variable-cycle engines

NASA Technical Reports Server (NTRS)

Willis, E. A.; Welliver, A. D.

1976-01-01

The evolution and current status of selected recent variable cycle engine (VCE) studies are reviewed, and how the results were influenced by airplane requirements is described. Promising VCE concepts are described, their designs are simplified and the potential benefits in terms of aircraft performance are identified. This includes range, noise, emissions, and the time and effort it may require to ensure technical readiness of sufficient depth to satisfy reasonable economic, performance, and environmental constraints. A brief overview of closely related, ongoing technology programs in acoustics and exhaust emissions is also presented. Realistic technology advancements in critical areas combined with well matched aircraft and selected VCE concepts can lead to significantly improved economic and environmental performance relative to first generation SST predictions.

40 CFR 63.325 - Determination of equivalent emission control technology.

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology. 63.325 Section 63.325 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Determination of equivalent emission control technology. (a) Any person requesting that the use of certain... equivalent emission reductions: (1) Diagrams, as appropriate, illustrating the emission control technology...

Testing the Hole-in-the-Pipe Model of nitric and nitrous oxide emissions from soils using the TRAGNET Database

NASA Astrophysics Data System (ADS)

Davidson, Eric A.; Verchot, Louis V.

2000-12-01

Because several soil properties and processes affect emissions of nitric oxide (NO) and nitrous oxide (N2O) from soils, it has been difficult to develop effective and robust algorithms to predict emissions of these gases in biogeochemical models. The conceptual "hole-in-the-pipe" (HIP) model has been used effectively to interpret results of numerous studies, but the ranges of climatic conditions and soil properties are often relatively narrow for each individual study. The Trace Gas Network (TRAGNET) database offers a unique opportunity to test the validity of one manifestation of the HIP model across a broad range of sites, including temperate and tropical climates, grasslands and forests, and native vegetation and agricultural crops. The logarithm of the sum of NO + N2O emissions was positively and significantly correlated with the logarithm of the sum of extractable soil NH4+ + NO3-. The logarithm of the ratio of NO:N2O emissions was negatively and significantly correlated with water-filled pore space (WFPS). These analyses confirm the applicability of the HIP model concept, that indices of soil N availability correlate with the sum of NO+N2O emissions, while soil water content is a strong and robust controller of the ratio of NO:N2O emissions. However, these parameterizations have only broad-brush accuracy because of unaccounted variation among studies in the soil depths where gas production occurs, where soil N and water are measured, and other factors. Although accurate predictions at individual sites may still require site-specific parameterization of these empirical functions, the parameterizations presented here, particularly the one for WFPS, may be appropriate for global biogeochemical modeling. Moreover, this integration of data sets demonstrates the broad ranging applicability of the HIP conceptual approach for understanding soil emissions of NO and N2O.

40 CFR 1045.801 - What definitions apply to this part?

Code of Federal Regulations, 2011 CFR

2011-07-01

... emission control device means any element of design that senses temperature, motive speed, engine RPM... of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.801 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... emission control device means any element of design that senses temperature, motive speed, engine RPM... of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.801 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... emission control device means any element of design that senses temperature, motive speed, engine RPM... of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.801 - What definitions apply to this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission control device means any element of design that senses temperature, motive speed, engine RPM... of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

Implications of Limiting CO2 Concentrations for Land Use and Energy

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

Wise, Marshall A.; Calvin, Katherine V.; Thomson, Allison M.

2009-05-29

This paper is the first to simultaneously examine the implications of extending the concept of placing a value on carbon beyond fossil fuel and industrial emissions to all sources, including those associated with land use and land use change. The paper reports a variety of results that have bearing on recent discussions in the literature regarding the role of bioenergy and the indirect emission of carbon through land-use change as well as the burgeoning literature on interactions between bioenergy and crop prices. This paper goes beyond results currently in the literature by using an integrated assessment model to assess energymore » use and supply, atmospheric composition, land use, and terrestrial carbon in the context of limiting the concentration of atmospheric CO2. We find that when the concept of valuing carbon emissions is extended to all carbon emissions, regardless of origin, that in contrast to a mitigation scenario where only fossil fuel and industrial carbon emissions are valued, deforestation is replaced by afforestation and expanded unmanaged ecosystems; the cost of limiting CO2 concentrations falls; crop prices rise; and human diets are transformed as people shift away from consumption of beef and other carbon-intensive protein sources. The increase in crop prices flows directly from the consideration of land-use change emissions in a comprehensive emissions mitigation program and occurs even in the absence of the use of purpose-grown bioenergy. Finally, we find that the assumed rate of improvement in food and fiber crop productivity (e.g. wheat, rice, corn) has a strong influence on land-use change emissions, making the technology for growing crops potentially as important for limiting atmospheric CO2 concentrations as energy technologies such as CO2 capture and storage.« less

40 CFR 1060.230 - How do I select emission families?

Code of Federal Regulations, 2011 CFR

2011-07-01

... family if they are the same in all the following aspects: (1) Emission control strategy and design. (2... POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT... emission characteristics throughout their useful life. (b) Group fuel lines into the same emission family...

40 CFR 76.10 - Alternative emission limitations.

Code of Federal Regulations, 2013 CFR

2013-07-01

...; and (ii) The installed NOX emission control system has been designed to meet the applicable emission... that the unit and NOX emission control system were operated in accordance with the bid and design specifications on which the design of the NOX emission control system was based; and (C) Unit operating data as...

40 CFR 1060.230 - How do I select emission families?

Code of Federal Regulations, 2013 CFR

2013-07-01

... family if they are the same in all the following aspects: (1) Emission control strategy and design. (2... POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT... emission characteristics throughout their useful life. (b) Group fuel lines into the same emission family...

40 CFR 1060.230 - How do I select emission families?

Code of Federal Regulations, 2012 CFR

2012-07-01

... family if they are the same in all the following aspects: (1) Emission control strategy and design. (2... POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT... emission characteristics throughout their useful life. (b) Group fuel lines into the same emission family...

40 CFR 76.10 - Alternative emission limitations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...; and (ii) The installed NOX emission control system has been designed to meet the applicable emission... that the unit and NOX emission control system were operated in accordance with the bid and design specifications on which the design of the NOX emission control system was based; and (C) Unit operating data as...

40 CFR 1060.230 - How do I select emission families?

Code of Federal Regulations, 2010 CFR

2010-07-01

... family if they are the same in all the following aspects: (1) Emission control strategy and design. (2... POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT... emission characteristics throughout their useful life. (b) Group fuel lines into the same emission family...

40 CFR 1060.230 - How do I select emission families?

Code of Federal Regulations, 2014 CFR

2014-07-01

... family if they are the same in all the following aspects: (1) Emission control strategy and design. (2... POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT... emission characteristics throughout their useful life. (b) Group fuel lines into the same emission family...

Low NOx Heavy Fuel Combustor Concept Program

NASA Technical Reports Server (NTRS)

Novick, A. S.; Troth, D. L.

1981-01-01

The development of the technology required to operate an industrial gas turbine combustion system on minimally processed, heavy petroleum or residual fuels having high levels of fuel-bound nitrogen (FBN) while producing acceptable levels of exhaust emissions is discussed. Three combustor concepts were designed and fabricated. Three fuels were supplied for the combustor test demonstrations: a typical middle distillate fuel, a heavy residual fuel, and a synthetic coal-derived fuel. The primary concept was an air staged, variable-geometry combustor designed to produce low emissions from fuels having high levels of FBN. This combustor used a long residence time, fuel-rich primary combustion zone followed by a quick-quench air mixer to rapidly dilute the fuel rich products for the fuel-lean final burnout of the fuel. This combustor, called the rich quench lean (RQL) combustor, was extensively tested using each fuel over the entire power range of the model 570 K engine. Also, a series of parameteric tests was conducted to determine the combustor's sensitivity to rich-zone equivalence ratio, lean-zone equivalence ratio, rich-zone residence time, and overall system pressure drop. Minimum nitrogen oxide emissions were measured at 50 to 55 ppmv at maximum continuous power for all three fuels. Smoke was less than a 10 SAE smoke number.

Crafting biochars to reduce N2O and CO2 emissions while also improving soil quality

NASA Astrophysics Data System (ADS)

Novak, Jeff; Ippolito, Jim; Spokas, Kurt; Sigua, Gilbert; Kammann, Claudia; Wrage-Monnig, Nicole; Borchard, Nils; Schirrmann, Michael; Estavillo, Jose Maria; Fuertes-Mendizabal, Teresa; Menendez, Sergio; Cayuela, Maria Luz

2017-04-01

Biochar used as an amendment has been linked to nitrous oxide (N2O) emission reductions, a decrease in nitrogen (N) leaching, and soil quality improvements (e.g., soil carbon sequestration, pH, etc.). While numerous articles will support these three facts, conversely, there are reports of no to marginal influences. One reason for the mixed biochar performance could be related to applying biochar with incorrect chemical and physical characteristics. As a means to increase biochar efficiency, we introduced the concept of crafting biochars with properties attuned to specific soil deficiencies. Implementing this concept requires a literature review to identify salient biochar characteristics that reduces N2O emissions, impacts N availability, while also improving soil quality. Thus, scientists from the USDA-ARS and through a coalition of European scientists under the FACCE-JPI umbrella have conceived the DesignChar4food (d4f) project. In this project, scientists are working collaboratively to further this concept to match the appropriate biochar for selective soil quality improvement, retain N for crops, and promote greenhouse gas reductions. This presentation will highlight results from the d4f team compromising a meta-analysis of articles on biochar:N2O dynamics, N availability, and how designer biochars can target specific soil quality improvements.

40 CFR 1060.101 - What evaporative emission requirements apply under this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (c) Section 1060.104 describes running loss emission control requirements for fuel systems. (d... AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD... related requirements as follows: (a) Section 1060.102 describes permeation emission control requirements...

High-speed civil transport - Advanced flight deck challenges

NASA Technical Reports Server (NTRS)

Swink, Jay R.; Goins, Richard T.

1992-01-01

This paper presents the results of a nine month study of the HSCT flight deck challenges and assessment of its benefits. Operational requirements are discussed and the most significant findings for specified advanced concepts are highlighted. These concepts are a no nose-droop configuration, a far forward cockpit location and advanced crew monitoring and control of complex systems. Results indicate that the no nose-droop configuration is critically dependent on the design and development of a safe, reliable and certifiable synthetic vision system (SVS). This configuration would cause significant weight, performance and cost penalties. A far forward cockpit configuration with a tandem seating arrangement allows either an increase in additional payload or potential downsizing of the vehicle leading to increased performance efficiency and reductions in emissions. The technologies enabling such capabilities, which provide for Category III all-weather opreations on every flight represent a benefit multiplier in a 20005 ATM network in terms of enhanced economic viability and environmental acceptability.

Active two-phase cooling of an IR window for a hypersonic interceptor

NASA Astrophysics Data System (ADS)

Burzlaff, B. H.; Chivian, Jay S.; Cotten, W. D.; Hemphill, R. B.; Huhlein, Michael A.

1993-06-01

A novel actively cooled window for an IR sensor on a hypersonic interceptor is envisioned which achieves an IR window with high transmittance, low emittance, and low image distortion under high aerodynamic heat flux. The cooling concept employs two-phase convective boiling of liquid ammonia. Coolant is confined to narrow, parallel channels within the window to minimize obscuration of the aperture. The high latent heat of vaporization of ammonia minimizes coolant mass-flow requirements. Low boiling temperatures at projected operating pressures promote high thermal conductivity and low emissivity in the window. The concept was tested with thermal measurements on sub-mm width coolant channels in Si. High values for heat transfer coefficient and critical heat flux were obtained. Thermal gradients within the window can be controlled by the coolant channel configuration. Design options are investigated by predicting the effect of aerodynamic heat flux on the image produced by an IR sensor with a cooled window. Ammonia-cooled IR windows will function in the anticipated aerothermal environment.

Information needs related to extension service and community outreach.

PubMed

Bottcher, Robert W

2003-06-01

Air quality affects everyone. Some people are affected by air quality impacts, regulations, and technological developments in several ways. Stakeholders include the medical community, ecologists, government regulators, industries, technology providers, academic professionals, concerned citizens, the news media, and elected officials. Each of these groups may perceive problems and opportunities differently, but all need access to information as it is developed. The diversity and complexity of air quality problems contribute to the challenges faced by extension and outreach professionals who must communicate with stakeholders having diverse backgrounds. Gases, particulates, biological aerosols, pathogens, and odors all require expensive and relatively complex technology to measure and control. Economic constraints affect the ability of regulators and others to measure air quality, and industry and others to control it. To address these challenges, while communicating air quality research results and concepts to stakeholders, three areas of information needs are evident. (1) A basic understanding of the fundamental concepts regarding air pollutants and their measurement and control is needed by all stakeholders; the Extension Specialist, to be effective, must help people move some distance up the learning curve. (2) Each problem or set of problems must be reasonably well defined since comprehensive solution of all problems simultaneously may not be feasible; for instance, the solution of an odor problem associated with animal production may not address atmospheric effects due to ammonia emissions. (3) The integrity of the communication process must be preserved by avoiding prejudice and protectionism; although stakeholders may seek to modify information to enhance their interests, extension and outreach professionals must be willing to present unwelcome information or admit to a lack of information. A solid grounding in fundamental concepts, careful and fair problem definition, and a resolute commitment to integrity and credibility will enable effective communication of air quality information to and among diverse stakeholders.

Constitutive acoustic-emission elastic-stress behavior of magnesium alloy

NASA Technical Reports Server (NTRS)

Williams, J. H., Jr.; Emerson, G. P.

1977-01-01

Repeated laoding and unloading of a magnesium alloy below the macroscopic yield stress result in continuous acoustic emissions which are generally repeatable for a given specimen and which are reproducible between different specimens having the same load history. An acoustic emission Bauschinger strain model is proposed to describe the unloading emission behavior. For the limited range of stress examined, loading and unloading stress delays of the order of 50 MN/sq m are observed, and they appear to be dependent upon the direction of loading, the stress rate, and the stress history. The stress delay is hypothesized to be the manifestation of an effective friction stress. The existence of acoustic emission elastic stress constitutive relations is concluded, which provides support for a previously proposed concept for the monitoring of elastic stresses by acoustic emission.

Pollution Reduction Technology Program for Small Jet Aircraft Engines, Phase 2

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1978-01-01

A series of iterative combustor pressure rig tests were conducted on two combustor concepts applied to the AiResearch TFE731-2 turbofan engine combustion system for the purpose of optimizing combustor performance and operating characteristics consistant with low emissions. The two concepts were an axial air-assisted airblast fuel injection configuration with variable-geometry air swirlers and a staged premix/prevaporization configuration. The iterative rig testing and modification sequence on both concepts was intended to provide operational compatibility with the engine and determine one concept for further evaluation in a TFE731-2 engine.

Adaptive Development

NASA Technical Reports Server (NTRS)

2005-01-01

The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

ASTER, a multinational Earth observing concept

NASA Technical Reports Server (NTRS)

Bothwell, Graham W.; Geller, Gary N.; Larson, Steven A.; Morrison, Andrew D.; Nichols, David A.

1993-01-01

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a facility instrument selected for launch in 1998 on the first in a series of spacecraft for NASA's Earth Observing System (EOS). The ASTER instrument is being sponsored and built in Japan. It is a three telescope, high spatial resolution imaging instrument with 15 spectral bands covering the visible through to the thermal infrared. It will play a significant role within EOS providing geological, biological, land hydrological information necessary for intense study of the Earth. The operational capabilities for ASTER, including the necessary interfaces and operational collaborations between the US and Japanese participants, are under development. EOS operations are the responsibility of the EOS Project at NASA's Goddard Space Flight Center (GSFC). Although the primary EOS control center is at GSFC, the ASTER control facility will be in Japan. Other aspects of ASTER are discussed.

Controlled Speed Accessory Drive demonstration program

NASA Technical Reports Server (NTRS)

Hoehn, F. W.

1981-01-01

A Controlled Speed Accessory Drive System was examined in an effort to improve the fuel economy of passenger cars. Concept feasibility and the performance of a typical system during actual road driving conditions were demonstrated. The CSAD system is described as a mechanical device which limits engine accessory speeds, thereby reducing parasitic horsepower losses and improving overall vehicle fuel economy. Fuel consumption data were compiled for fleets of GSA vehicles. Various motor pool locations were selected, each representing different climatic conditions. On the basis of a total accumulated fleet usage of nearly three million miles, an overall fuel economy improvement of 6 percent to 7 percent was demonstrated. Coincident chassis dynamometer tests were accomplished on selected vehicles to establish the effect of different accessory drive systems on exhaust emissions, and to evaluate the magnitude of the mileage benefits which could be derived.

40 CFR 1039.801 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... operation in water. Auxiliary emission-control device means any element of design that senses temperature... element of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Definitions...

40 CFR 1039.801 - What definitions apply to this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... operation in water. Auxiliary emission-control device means any element of design that senses temperature... element of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Definitions...

40 CFR 1039.801 - What definitions apply to this part?

Code of Federal Regulations, 2011 CFR

2011-07-01

... operation in water. Auxiliary emission-control device means any element of design that senses temperature... element of design that controls or reduces the emissions of regulated pollutants from an engine. Emission... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Definitions...

40 CFR 1060.103 - What permeation emission control requirements apply for fuel tanks?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control... AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Emission Standards and Related Requirements § 1060.103 What permeation...

Complexity Science Applications to Dynamic Trajectory Management: Research Strategies

NASA Technical Reports Server (NTRS)

Sawhill, Bruce; Herriot, James; Holmes, Bruce J.; Alexandrov, Natalia

2009-01-01

The promise of the Next Generation Air Transportation System (NextGen) is strongly tied to the concept of trajectory-based operations in the national airspace system. Existing efforts to develop trajectory management concepts are largely focused on individual trajectories, optimized independently, then de-conflicted among each other, and individually re-optimized, as possible. The benefits in capacity, fuel, and time are valuable, though perhaps could be greater through alternative strategies. The concept of agent-based trajectories offers a strategy for automation of simultaneous multiple trajectory management. The anticipated result of the strategy would be dynamic management of multiple trajectories with interacting and interdependent outcomes that satisfy multiple, conflicting constraints. These constraints would include the business case for operators, the capacity case for the Air Navigation Service Provider (ANSP), and the environmental case for noise and emissions. The benefits in capacity, fuel, and time might be improved over those possible under individual trajectory management approaches. The proposed approach relies on computational agent-based modeling (ABM), combinatorial mathematics, as well as application of "traffic physics" concepts to the challenge, and modeling and simulation capabilities. The proposed strategy could support transforming air traffic control from managing individual aircraft behaviors to managing systemic behavior of air traffic in the NAS. A system built on the approach could provide the ability to know when regions of airspace approach being "full," that is, having non-viable local solution space for optimizing trajectories in advance.

Exploring dust emission responses to land cover change using an ecological land classification

NASA Astrophysics Data System (ADS)

Galloza, Magda S.; Webb, Nicholas P.; Bleiweiss, Max P.; Winters, Craig; Herrick, Jeffrey E.; Ayers, Eldon

2018-06-01

Despite efforts to quantify the impacts of land cover change on wind erosion, assessment uncertainty remains large. We address this uncertainty by evaluating the application of ecological site concepts and state-and-transition models (STMs) for detecting and quantitatively describing the impacts of land cover change on wind erosion. We apply a dust emission model over a rangeland study area in the northern Chihuahuan Desert, New Mexico, USA, and evaluate spatiotemporal patterns of modelled horizontal sediment mass flux and dust emission in the context of ecological sites and their vegetation states; representing a diversity of land cover types. Our results demonstrate how the impacts of land cover change on dust emission can be quantified, compared across land cover classes, and interpreted in the context of an ecological model that encapsulates land management intensity and change. Results also reveal the importance of established weaknesses in the dust model soil characterisation and drag partition scheme, which appeared generally insensitive to the impacts of land cover change. New models that address these weaknesses, coupled with ecological site concepts and field measurements across land cover types, could significantly reduce assessment uncertainties and provide opportunities for identifying land management options.

A Low NO(x) Lean-Direct Injection, Multipoint Integrated Module Combuster Concept for Advanced Aircraft Gas Turbines

NASA Technical Reports Server (NTRS)

Tacina, Robert; Wey, Changlie; Laing, Peter; Mansour, Adel

2002-01-01

A low NO(x) emissions combustor has been demonstrated in flame-tube tests. A multipoint, lean-direct injection concept was used. Configurations were tested that had 25- and 36- fuel injectors in the size of a conventional single fuel injector. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers and fuel manifold into a single element. Test conditions were inlet temperatures up to 810 K, inlet pressures up to 2760 kPa, and flame temperatures up to 2100 K. A correlation was developed relating the NO(x) emissions with the inlet temperature, inlet pressure, fuel-air ratio and pressure drop. Assuming that 10 percent of the combustion air would be used for liner cooling and using a hypothetical engine cycle, the NO(x) emissions using the correlation from flame-tube tests were estimated to be less than 20 percent of the 1996 ICAO standard.

Science and policy applicability of the transient climate response to cumulative emissions of carbon

NASA Astrophysics Data System (ADS)

Rogelj, J.

2014-12-01

The Transient Climate Response to cumulative Carbon Emissions (TCRE) provides a quantification of the near-linear relationship between cumulative emissions of carbon and global-mean temperature increase. For its most recent report, the Intergovernmental Panel on Climate Change bases its assessment on a large body of literature which encompasses multiple lines of evidence. In this session I will look at the literature basis that was available for TCRE at the time of the IPCC Fifth Assessment Report, providing an easy-to-access introduction into the TCRE concept. Building on this basis and summarizing my own recent work on this, I will discuss the strengths and weaknesses of the use of TCRE for climate policy. While the TCRE concept provides a clear long-term view of what is required to stabilize global-mean temperature increase, I will explore how TCRE uncertainties might pose problems for using TCRE as the only policy guidance in near-term policy decisions.

B-MINE: The Balloon-Borne Microcalorimeter Nuclear Line Explorer

NASA Technical Reports Server (NTRS)

Silver, E.; Schnopper, H.; Jones, C.; Forman, W.; Bandler, S.; Murray, S.; Romaine, S.; Slane, P.; Grindlay, J.; Madden, N.

2001-01-01

B-MINE is a concept for a balloon mission designed to probe the deepest regions of a supernova explosion by detecting 44Ti emission at 68 keV with spatial and spectral resolutions that are sufficient to determine the extent and velocity distribution of the 44Ti emitting region. The payload introduces the concept of focusing optics and microcalorimeter spectroscopy to nuclear line emission astrophysics. B-MINE has a thin, plastic foil telescope multilayered to maximize the reflectivity in a 20 keV band centered at 68 keV and a microcalorimeter array optimized for the same energy band. This combination provides a reduced background, an energy resolution of 50 eV and a 3 sigma sensitivity in 10 (exp 6) s of 3.3 x 10(exp -7) ph cm(exp -2) s(exp -1) at 68 keV. During the course of a long duration balloon flight, B-MINE could carry out a detailed study of the 44Ti emission line centroid and width in CAS A.

Characterization of in-use light-duty gasoline vehicle emissions by remote sensing in Beijing: impact of recent control measures.

PubMed

Zhou, Yu; Fu, Lixin; Cheng, Linglin

2007-09-01

China's national government and Beijing city authorities have adopted additional control measures to reduce the negative impact of vehicle emissions on Beijing's air quality. An evaluation of the effectiveness of these measures may provide guidance for future vehicle emission control strategy development. In-use emissions from light-duty gasoline vehicles (LDGVs) were investigated at five sites in Beijing with remote sensing instrumentation. Distance-based mass emission factors were derived with fuel consumption modeled on real world data. The results show that the recently implemented aggressive control strategies are significantly reducing the emissions of on-road vehicles. Older vehicles are contributing substantially to the total fleet emissions. An earlier program to retrofit pre-Euro cars with three-way catalysts produced little emission reduction. The impact of model year and driving conditions on the average mass emission factors indicates that the durability of vehicles emission controls may be inadequate in Beijing.

P and W propulsion systems studies results/status

NASA Technical Reports Server (NTRS)

Smith, Martin G., Jr.; Champagne, George A.

1992-01-01

The topics covered include the following: Pratt and Whitney (P&W) propulsion systems studies - NASA funded efforts to date; P&W engine concepts; P&W combustor focus - rich burn quick quench (RBQQ) concept; mixer ejector nozzle concept - large flow entrainment reduces jet noise; technology impact on NO(x) emissions - mature RBQQ combustor reduces NO(x) up to 85 percent; technology impact on sideline noise characteristics of Mach 2.4 turbine bypass engines (TBE's) - 600 lb/sec airflow size; technology impact on takeoff gross weight (TOGW) - provides up to 12 percent TOGW reduction; HSCT quiet engine concepts; TBE inlet valve/ejector nozzle concept schematic; mixed flow turbofan study; and exhaust nozzle conceptual design.

NASA Glenn Research Center UEET (Ultra-Efficient Engine Technology) Program: Agenda and Abstracts

NASA Technical Reports Server (NTRS)

Manthey, Lri

2001-01-01

Topics discussed include: UEET Overview; Technology Benefits; Emissions Overview; P&W Low Emissions Combustor Development; GE Low Emissions Combustor Development; Rolls-Royce Low Emissions Combustor Development; Honeywell Low Emissions Combustor Development; NASA Multipoint LDI Development; Stanford Activities In Concepts for Advanced Gas Turbine Combustors; Large Eddy Simulation (LES) of Gas Turbine Combustion; NASA National Combustion Code Simulations; Materials Overview; Thermal Barrier Coatings for Airfoil Applications; Disk Alloy Development; Turbine Blade Alloy; Ceramic Matrix Composite (CMC) Materials Development; Ceramic Matrix Composite (CMC) Materials Characterization; Environmental Barrier Coatings (EBC) for Ceramic Matrix Composite (CMC) Materials; Ceramic Matrix Composite Vane Rig Testing and Design; Ultra-High Temperature Ceramic (UHTC) Development; Lightweight Structures; NPARC Alliance; Technology Transfer and Commercialization; and Turbomachinery Overview; etc.

The blue skies in Beijing during APEC 2014: A quantitative assessment of emission control efficiency and meteorological influence

NASA Astrophysics Data System (ADS)

Liu, Hongli; He, Jing; Guo, Jianping; Miao, Yucong; Yin, Jinfang; Wang, Yuan; Xu, Hui; Liu, Huan; Yan, Yan; Li, Yuan; Zhai, Panmao

2017-10-01

Most previous studies attributed the alleviation of aerosol pollution to either emission control measures or favorable meteorological conditions. However, our understanding of their quantitative contribution is far from complete. In this study, based on model simulation using the CMA (China Meteorological Administration) Unified Atmospheric Chemistry Environment for aerosols (CUACE/Aero), in combination with simultaneous ground-based hourly PM2.5 observations, we aim to quantify the relative contributions of the emission control measures and meteorology to the blue-skies seen in Beijing during the Asia-Pacific Economic Cooperation (APEC) summit held in November of 2014. A series of model simulations have been performed over Beijing-Tianjin-Hebei (BTH) region by implementing nine different emission control schemes. To investigate the relative contributions of the emission control measures and meteorology, the study period has been divided into five episodes. Overall, the CUACE/Aero model can reasonably well reproduce the temporal and spatial evolution of PM2.5 during APEC 2014, although the model performance varies by different time periods and regions of interest. Model results show the emission control measures on average reduced the PM2.5 concentration by 41.3% in urban areas of Beijing and 39.7% in Huairou district, respectively, indicating emission control plays a significant role for the blue skies observed. Among all the emission control measures under investigation, local emission control in Beijing contributed the largest to the reduction of PM2.5 concentrations with a reduction of 35.5% in urban area of Beijing and 34.8% in Huairou, in contrast with the vehicle emission control in Hebei that contributed the least with a reduction of less than 1%. The emission control efficiency in five episodes has been assessed quantitatively, which falls in the range of 36.2%-41.2% in urban area of Beijing and 34.9%-40.7% in Huairou, indicative of no significant episode and geographic dependence in the emission control efficiency. The emission control measures and meteorology, however, alternated to dominate the absolute reduction of PM2.5 concentrations. When the weather conditions are unfavorable, emission control measures outperformed meteorology with a reduction of 55.3-59.4 μg/m3 in urban area of Beijing and 32.5-33 μg/m3 in Huairou. Conversely, when the northwesterly winds prevailed, meteorology tends to outweigh the role of emission control in accounting for the drop of PM2.5. The atmospheric dilution conditions are determined through the model calculation of the mass inflow of PM2.5 per unit volume near the surface. Our findings have significant implications for effective planning and implementation of emission control measures.

Analytical fuel property effects--small combustors

NASA Technical Reports Server (NTRS)

Sutton, R. D.; Troth, D. L.; Miles, G. A.

1984-01-01

The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

Analytical evaluation of the impact of broad specification fuels on high bypass turbofan engine combustors

NASA Technical Reports Server (NTRS)

Taylor, J. R.

1979-01-01

Six conceptual combustor designs for the CF6-50 high bypass turbofan engine and six conceptual combustor designs for the NASA/GE E3 high bypass turbofan engine were analyzed to provide an assessment of the major problems anticipated in using broad specification fuels in these aircraft engine combustion systems. Each of the conceptual combustor designs, which are representative of both state-of-the-art and advanced state-of-the-art combustion systems, was analyzed to estimate combustor performance, durability, and pollutant emissions when using commercial Jet A aviation fuel and when using experimental referee board specification fuel. Results indicate that lean burning, low emissions double annular combustor concepts can accommodate a wide range of fuel properties without a serious deterioration of performance or durability. However, rich burning, single annular concepts would be less tolerant to a relaxation of fuel properties. As the fuel specifications are relaxed, autoignition delay time becomes much smaller which presents a serious design and development problem for premixing-prevaporizing combustion system concepts.

Global projections and climate stabilisation targets

NASA Astrophysics Data System (ADS)

Friedlingstein, Pierre

2014-05-01

The Summary for policy makers of the 5th Assessment Report of the Working Group 1 of IPCC has a figure that has no equivalent in previous IPCC assessment reports. This new figure shows the change in global average surface temperature as a function of cumulative anthropogenic emissions of CO2. In this talk I will describe how the concept of transient climate response to cumulative emissions (TCRE) that supports that figure emerged from the literature over the recent years and what are the fundamental physical and biogeochemical processes that explain this relationship and its linearity. I will also explore the implication of TCRE for long-term climate change and mitigation strategies as well as the limitations of the concept of TCRE.

Component testing of a ground based gas turbine steam cooled rich-burn primary zone combustor for emissions control of nitrogeneous fuels

NASA Technical Reports Server (NTRS)

Schultz, D. F.

1986-01-01

This effort summarizes the work performed on a steam cooled, rich-burn primary zone, variable geometry combustor designed for combustion of nitrogeneous fuels such as heavy oils or synthetic crude oils. The steam cooling was employed to determine its feasibility and assess its usefulness as part of a ground based gas turbine bottoming cycle. Variable combustor geometry was employed to demonstrate its ability to control primary and secondary zone equivalence ratios and overall pressure drop. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This low temperature offers the potential of both long life and reduced use of strategic materials for liner fabrication. These degrees of variable geometry were successfully employed to control air flow distribution within the combustor. A variable blade angle axial flow air swirler was used to control primary zone air flow, while the secondary and tertiary zone air flows were controlled by rotating bands which regulated air flow to the secondary zone quench holes and the dilutions holes respectively.

Global climate targets and future consumption level: an evaluation of the required GHG intensity

NASA Astrophysics Data System (ADS)

Girod, Bastien; van Vuuren, Detlef Peter; Hertwich, Edgar G.

2013-03-01

Discussion and analysis on international climate policy often focuses on the rather abstract level of total national and regional greenhouse gas (GHG) emissions. At some point, however, emission reductions need to be translated to consumption level. In this article, we evaluate the implications of the strictest IPCC representative concentration pathway for key consumption categories (food, travel, shelter, goods, services). We use IPAT style identities to account for possible growth in global consumption levels and indicate the required change in GHG emission intensity for each category (i.e. GHG emission per calorie, person kilometer, square meter, kilogram, US dollar). The proposed concept provides guidance for product developers, consumers and policymakers. To reach the 2 °C climate target (2.1 tCO2-eq. per capita in 2050), the GHG emission intensity of consumption has to be reduced by a factor of 5 in 2050. The climate targets on consumption level allow discussion of the feasibility of this climate target at product and consumption level. In most consumption categories products in line with this climate target are available. For animal food and air travel, reaching the GHG intensity targets with product modifications alone will be challenging and therefore structural changes in consumption patterns might be needed. The concept opens up possibilities for further research on potential solutions on the consumption and product level to global climate mitigation.

Rubbertown NGEM Demonstration Project Planning meetings ...

EPA Pesticide Factsheets

From the shared perspective of industrial facilities, workers, regulators, and communities, cost-effective detection and assessment of significant onset fugitive leaks or process issues, is a mutually beneficial concept. If emissions that require mitigation can be detected and fixed quickly, benefits such as safer working environments, cost saving through reduced product loss, lower air shed pollutant impacts, and improved transparency and community relations can be realized. Under its next generation emission measurement program (NGEM), EPA’s Office of Research and Development (ORD), National Risk Management Research Laboratory (NRMRL) is working collaboratively with industry, instrument /information companies, state and local agencies, communities, and academic groups to explore new technical approaches for non-point source detection and migration. Techniques such as mobile and fixed point sensors and passive samplers employed on various spatial scales are being explored. With collaboration of the project team including EPA R4, the Louisville Metro Air Pollution Control District (LMAPCD), industrial facilities, and contractors to the EPA, a select subset of these NGEM approaches will be demonstrated in this project as per the quality assurance project plan. From April 17-20, 2017, E. Thoma will travel to Louisville KY to work with the Louisville Metro Air Pollution Control District (LMAPCD) and other parties for planning activities related to the

40 CFR 270.27 - Specific Part B information requirements for air emission controls for tanks, surface...

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements for air emission controls for tanks, surface impoundments, and containers. 270.27 Section 270.27... information requirements for air emission controls for tanks, surface impoundments, and containers. (a) Except... containers that use air emission controls in accordance with the requirements of 40 CFR part 264, subpart CC...

40 CFR 270.27 - Specific Part B information requirements for air emission controls for tanks, surface...

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements for air emission controls for tanks, surface impoundments, and containers. 270.27 Section 270.27... information requirements for air emission controls for tanks, surface impoundments, and containers. (a) Except... containers that use air emission controls in accordance with the requirements of 40 CFR part 264, subpart CC...

40 CFR 270.27 - Specific Part B information requirements for air emission controls for tanks, surface...

Code of Federal Regulations, 2011 CFR

2011-07-01

... requirements for air emission controls for tanks, surface impoundments, and containers. 270.27 Section 270.27... information requirements for air emission controls for tanks, surface impoundments, and containers. (a) Except... containers that use air emission controls in accordance with the requirements of 40 CFR part 264, subpart CC...

40 CFR 270.27 - Specific Part B information requirements for air emission controls for tanks, surface...

Code of Federal Regulations, 2012 CFR

2012-07-01

... requirements for air emission controls for tanks, surface impoundments, and containers. 270.27 Section 270.27... information requirements for air emission controls for tanks, surface impoundments, and containers. (a) Except... containers that use air emission controls in accordance with the requirements of 40 CFR part 264, subpart CC...

40 CFR 270.27 - Specific Part B information requirements for air emission controls for tanks, surface...

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements for air emission controls for tanks, surface impoundments, and containers. 270.27 Section 270.27... information requirements for air emission controls for tanks, surface impoundments, and containers. (a) Except... containers that use air emission controls in accordance with the requirements of 40 CFR part 264, subpart CC...

Energy-Efficient and Low-GHG-Emission "Thiometallurgy"

NASA Astrophysics Data System (ADS)

Neelameggham, Neale R.; Brown, Robert E.; Davis, Brian R.

2014-09-01

Extractive metallurgy has used free or combined sulfur as both the raw material and the energy material in carrying out economical manufacture of several metals in millions of tons per year quantities over the past century. This has controlled carbon emissions in an unintentional fashion and out of necessity as the ores in many cases have been sulfides to start with. And the benefits of heat generation by the sulfides reacting with oxygen in the process steps have avoided the use of carbon as a fuel in providing the reaction temperatures. In this article, we will show the inherent benefits of "thiometallurgy," which uses sulfur in the extraction of metals in alleviating CO2 and water vapor-greenhouse gas (GHG) emissions, as well as its ability to provide a cost-effective energy material solution. Such solutions are not only applicable to existing base metal production but, as the authors will show, also are applicable to newer processes in the production of other metals and chemicals, such as alkaline earth metals, titanium, and to an extent aluminum in an indirect fashion. Iron ores can also be treated with thiometallurgy to meet the ULCOS criterion of ultra-low carbon dioxide steel being studied in Europe. The concept of generating "thiopower" as an alternative energy approach is also introduced by the authors.

Hydrogen/Air Fuel Nozzle Emissions Experiments

NASA Technical Reports Server (NTRS)

Smith, Timothy D.

2001-01-01

The use of hydrogen combustion for aircraft gas turbine engines provides significant opportunities to reduce harmful exhaust emissions. Hydrogen has many advantages (no CO2 production, high reaction rates, high heating value, and future availability), along with some disadvantages (high current cost of production and storage, high volume per BTU, and an unknown safety profile when in wide use). One of the primary reasons for switching to hydrogen is the elimination of CO2 emissions. Also, with hydrogen, design challenges such as fuel coking in the fuel nozzle and particulate emissions are no longer an issue. However, because it takes place at high temperatures, hydrogen-air combustion can still produce significant levels of NOx emissions. Much of the current research into conventional hydrocarbon-fueled aircraft gas turbine combustors is focused on NOx reduction methods. The Zero CO2 Emission Technology (ZCET) hydrogen combustion project will focus on meeting the Office of Aerospace Technology goal 2 within pillar one for Global Civil Aviation reducing the emissions of future aircraft by a factor of 3 within 10 years and by a factor of 5 within 25 years. Recent advances in hydrocarbon-based gas turbine combustion components have expanded the horizons for fuel nozzle development. Both new fluid designs and manufacturing technologies have led to the development of fuel nozzles that significantly reduce aircraft emissions. The goal of the ZCET program is to mesh the current technology of Lean Direct Injection and rocket injectors to provide quick mixing, low emissions, and high-performance fuel nozzle designs. An experimental program is planned to investigate the fuel nozzle concepts in a flametube test rig. Currently, a hydrogen system is being installed in cell 23 at NASA Glenn Research Center's Research Combustion Laboratory. Testing will be conducted on a variety of fuel nozzle concepts up to combustion pressures of 350 psia and inlet air temperatures of 1200 F. Computational fluid dynamics calculations, with the Glenn developed National Combustor Code, are being performed to optimize the fuel nozzle designs.

Symbolic dynamics for arrhythmia identification from heart variability of rats with cardiac failures

NASA Astrophysics Data System (ADS)

Letellier, C.; Roulin, E.; Loriot, S.; Morin, J.-P.; Dionnet, F.

2004-12-01

Heart rate variability of rats is investigated using concepts from the nonlinear dynamical system theory. Among the important techniques offered, symbolic dynamics is very appealing by its power to investigate patterns which can be repeated in a time series. The present analysis was performed in six control rats and six chronic cardiac insufficient rats (myocardial infarction due to left descendent coronary artery ligation). Rats are left in clean atmosphere or exposed to atmosphere containing diluted engine emission pollutants. The evolution of the heart rate variability is then investigated with a three element symbolic dynamics which allows to distinguish extrasystoles from tachycardia or bradycardia using the symbol sequences.

Greenhouse Effect, Radiative Forcing and Climate Sensitivity

NASA Astrophysics Data System (ADS)

Ponater, Michael; Dietmüller, Simone; Sausen, Robert

Temperature conditions and climate on Earth are controlled by the balance between absorbed solar radiation and outgoing terrestrial radiation. The greenhouse effect is a synonym for the trapping of infrared radiation by radiatively active atmospheric constituents. It generally causes a warming of the planet's surface, compared to the case without atmosphere. Perturbing the radiation balance of the planet, e.g., by anthropogenic greenhouse gas emissions, induces climate change. Individual contributions to a total climate impact are usually quantified and ranked in terms of their respective radiative forcing. This method involves some limitations, because the effect of the external forcing is modified by radiative feedbacks. Here the current concept of radiative forcing and potential improvements are explained.

Passive Coherent Detection and Target Location with Multiple Non-Cooperative Transmitters

DTIC Science & Technology

2015-06-01

to detect, separate, classify, locate, and track sources of emissions in multi-target environments—triggered the development of passive radar...radar capitalizes on transmitters of opportunity to detect and locate sources of transmission or targets without deliberate emissions . The...equipment as all necessary hardware is currently available on most naval ships. 3 Bistatic radar geometry. Figure 1. B. HISTORY The concept of

Students' Understanding of the Greenhouse Effect, the Societal Consequences of Reducing CO2 Emissions and the Problem of Ozone Layer Depletion.

ERIC Educational Resources Information Center

Andersson, Bjorn; Wallin, Anita

2000-01-01

Contributes to the growing body of knowledge about students' conceptions and views of environmental and natural resource issues. Questions 9th and 12th grade Swedish students' understandings of the greenhouse effect, reduction of CO2 emissions, and the depletion of the ozone layer. Observes five models of the greenhouse effect that appear among…

Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

ERIC Educational Resources Information Center

Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

2016-01-01

Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

The acidity problem -- an outline of concepts

Treesearch

Svante Od& #233; n; Svante n

1976-01-01

The changing acidity of air and precipitation over most of Europe and part of U. S. is only part of a larger problem--changes of the chemical climate caused by a variety of emissions into the atmosphere (13, 36). These emissions may create a local, a regional or a global situation depending only on the life-time of the pollutants in the atmosphere. The atmospheric...

Fuel Consumption and Emissions from Airport Taxi Operations

NASA Technical Reports Server (NTRS)

Jung, Yoon

2010-01-01

Developed a method to calculate fuel consumption and emissions of phases of taxi operations. Results at DFW showed that up to 18% of fuel can be saved by eliminating stop-and-go situations. Developed an energy efficient and environmentally friendly surface concept: Spot and Runway Departure Advisory (SARDA) tool. The SARDA tool has been identified as a potential candidate for a technology transfer to the FAA.

Thermally enhanced photoluminescence for energy harvesting: from fundamentals to engineering optimization

NASA Astrophysics Data System (ADS)

Kruger, N.; Kurtulik, M.; Revivo, N.; Manor, A.; Sabapathy, T.; Rotschild, C.

2018-05-01

The radiance of thermal emission, as described by Planck’s law, depends only on the emissivity and temperature of a body, and increases monotonically with the temperature rise at any emitted wavelength. Non-thermal radiation, such as photoluminescence (PL), is a fundamental light–matter interaction that conventionally involves the absorption of an energetic photon, thermalization, and the emission of a redshifted photon. Such a quantum process is governed by rate conservation, which is contingent on the quantum efficiency. In the past, the role of rate conservation for significant thermal excitation had not been studied. Recently, we presented the theory and an experimental demonstration that showed, in contrast to thermal emission, that the PL rate is conserved when the temperature increases while each photon is blueshifted. A further rise in temperature leads to an abrupt transition to thermal emission where the photon rate increases sharply. We also demonstrated how such thermally enhanced PL (TEPL) generates orders of magnitude more energetic photons than thermal emission at similar temperatures. These findings show that TEPL is an ideal optical heat pump that can harvest thermal losses in photovoltaics with a maximal theoretical efficiency of 70%, and practical concepts potentially reaching 45% efficiency. Here we move the TEPL concept onto the engineering level and present Cr:Nd:YAG as device grade PL material, absorbing solar radiation up to 1 μm wavelength and heated by thermalization of energetic photons. Its blueshifted emission, which can match GaAs cells, is 20% of the absorbed power. Based on a detailed balance simulation, such a material coupled with proper photonic management can reach 34% power conversion efficiency. These results raise confidence in the potential of TEPL becoming a disruptive technology in photovoltaics.

Low Emissions RQL Flametube Combustor Component Test Results

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Chang, Clarence T.

2001-01-01

This report describes and summarizes elements of the High Speed Research (HSR) Low Emissions Rich burn/Quick mix/Lean burn (RQL) flame tube combustor test program. This test program was performed at NASA Glenn Research Center circa 1992. The overall objective of this test program was to demonstrate and evaluate the capability of the RQL combustor concept for High Speed Civil Transport (HSCT) applications with the goal of achieving NOx emission index levels of 5 g/kg-fuel at representative HSCT supersonic cruise conditions. The specific objectives of the tests reported herein were to investigate component performance of the RQL combustor concept for use in the evolution of ultra-low NOx combustor design tools. Test results indicated that the RQL combustor emissions and performance at simulated supersonic cruise conditions were predominantly sensitive to the quick mixer subcomponent performance and not sensitive to fuel injector performance. Test results also indicated the mixing section configuration employing a single row of circular holes was the lowest NOx mixer tested probably due to the initial fast mixing characteristics of this mixing section. However, other quick mix orifice configurations such as the slanted slot mixer produced substantially lower levels of carbon monoxide emissions most likely due to the enhanced circumferential dispersion of the air addition. Test results also suggested that an optimum momentum-flux ratio exists for a given quick mix configuration. This would cause undesirable jet under- or over-penetration for test conditions with momentum-flux ratios below or above the optimum value. Tests conducted to assess the effect of quick mix flow area indicated that reduction in the quick mix flow area produced lower NOx emissions at reduced residence time, but this had no effect on NOx emissions measured at similar residence time for the configurations tested.

40 CFR 86.1803-01 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... which are designed primarily for emission control, or whose failure may result in a significant increase... waiver of emission data submission requirements under § 86.1829-01. Element of design means any control... a motor vehicle or motor vehicle engine. Emission control system is a unique group of emission...

40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES..., replacement, or repair of the emission control devices and systems may be performed by any engine repair... and necessary to ensure the proper functioning of the engine's emission control systems. If the...

40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES..., replacement, or repair of the emission control devices and systems may be performed by any engine repair... and necessary to ensure the proper functioning of the engine's emission control systems. If the...

40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES..., replacement, or repair of the emission control devices and systems may be performed by any engine repair... and necessary to ensure the proper functioning of the engine's emission control systems. If the...

Cumulative carbon emissions, emissions floors and short-term rates of warming: implications for policy.

PubMed

Bowerman, Niel H A; Frame, David J; Huntingford, Chris; Lowe, Jason A; Allen, Myles R

2011-01-13

A number of recent studies have found a strong link between peak human-induced global warming and cumulative carbon emissions from the start of the industrial revolution, while the link to emissions over shorter periods or in the years 2020 or 2050 is generally weaker. However, cumulative targets appear to conflict with the concept of a 'floor' in emissions caused by sectors such as food production. Here, we show that the introduction of emissions floors does not reduce the importance of cumulative emissions, but may make some warming targets unachievable. For pathways that give a most likely warming up to about 4°C, cumulative emissions from pre-industrial times to year 2200 correlate strongly with most likely resultant peak warming regardless of the shape of emissions floors used, providing a more natural long-term policy horizon than 2050 or 2100. The maximum rate of CO(2)-induced warming, which will affect the feasibility and cost of adapting to climate change, is not determined by cumulative emissions but is tightly aligned with peak rates of emissions. Hence, cumulative carbon emissions to 2200 and peak emission rates could provide a clear and simple framework for CO(2) mitigation policy.

Reports related to Emissions Control Areas for Marine Vessels

EPA Pesticide Factsheets

Reports related to Marine Emissions Control Areas including Global Trade and Fuels Assessment, Modeling Sulfur Oxides Emissions Transport From Ships at Sea, Commercial Marine Emission Inventory Development

40 CFR 63.3555 - How do I determine the outlet THC emissions and add-on control device emission destruction or...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true How do I determine the outlet THC.../outlet Concentration Option § 63.3555 How do I determine the outlet THC emissions and add-on control... section to determine either the outlet THC emissions or add-on control device emission destruction or...

40 CFR 63.3555 - How do I determine the outlet THC emissions and add-on control device emission destruction or...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true How do I determine the outlet THC... Control Efficiency/outlet Concentration Option § 63.3555 How do I determine the outlet THC emissions and... methods in this section to determine either the outlet THC emissions or add-on control device emission...

40 CFR 63.3555 - How do I determine the outlet THC emissions and add-on control device emission destruction or...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false How do I determine the outlet THC... Control Efficiency/outlet Concentration Option § 63.3555 How do I determine the outlet THC emissions and... methods in this section to determine either the outlet THC emissions or add-on control device emission...

40 CFR 63.3555 - How do I determine the outlet THC emissions and add-on control device emission destruction or...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true How do I determine the outlet THC.../outlet Concentration Option § 63.3555 How do I determine the outlet THC emissions and add-on control... section to determine either the outlet THC emissions or add-on control device emission destruction or...

40 CFR 63.3555 - How do I determine the outlet THC emissions and add-on control device emission destruction or...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false How do I determine the outlet THC... Control Efficiency/outlet Concentration Option § 63.3555 How do I determine the outlet THC emissions and... methods in this section to determine either the outlet THC emissions or add-on control device emission...

40 CFR 75.19 - Optional SO2, NOX, and CO2 emissions calculation for low mass emissions (LME) units.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (or group of identical units) equipped with SCR (or SNCR) and uses dry low-NOX technology to control... with add-on NOX emission controls, and for units that use dry low-NOX technology, the owner or operator... mass emissions unit that uses dry low-NOX premix technology to control NOX emissions, proper operation...

77 FR 45337 - U.S. Environmental Solutions Toolkit

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

... services relevant to (a) groundwater remediation; (b) mercury emissions control from power plants; (c...) Groundwater remediation (b) Mercury emissions control from power plants (c) Emissions control from large...

40 CFR 1054.205 - What must I include in my application?

Code of Federal Regulations, 2012 CFR

2012-07-01

... emission family's specifications and other basic parameters of the engine's design and emission controls. List the fuel type on which your engines are designed to operate (for example, all-season gasoline... emission control systems operate. Describe the evaporative emission controls and show how your design will...

40 CFR 1054.205 - What must I include in my application?

Code of Federal Regulations, 2011 CFR

2011-07-01

... emission family's specifications and other basic parameters of the engine's design and emission controls. List the fuel type on which your engines are designed to operate (for example, all-season gasoline... emission control systems operate. Describe the evaporative emission controls and show how your design will...

40 CFR 1054.205 - What must I include in my application?

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission family's specifications and other basic parameters of the engine's design and emission controls. List the fuel type on which your engines are designed to operate (for example, all-season gasoline... emission control systems operate. Describe the evaporative emission controls and show how your design will...

40 CFR 1054.205 - What must I include in my application?

Code of Federal Regulations, 2013 CFR

2013-07-01

... emission family's specifications and other basic parameters of the engine's design and emission controls. List the fuel type on which your engines are designed to operate (for example, all-season gasoline... emission control systems operate. Describe the evaporative emission controls and show how your design will...

40 CFR 1054.205 - What must I include in my application?

Code of Federal Regulations, 2014 CFR

2014-07-01

... emission family's specifications and other basic parameters of the engine's design and emission controls. List the fuel type on which your engines are designed to operate (for example, all-season gasoline... emission control systems operate. Describe the evaporative emission controls and show how your design will...

40 CFR 63.1332 - Emissions averaging provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... other controls for a Group 1 storage vessel, batch process vent, aggregate batch vent stream, continuous... in control after November 15, 1990. (2) Group 1 emission points, identified in paragraph (c)(3) of... applicable reference control technology or standard and the emissions allowed for the Group 1 emission point...

40 CFR 63.1332 - Emissions averaging provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... other controls for a Group 1 storage vessel, batch process vent, aggregate batch vent stream, continuous... in control after November 15, 1990. (2) Group 1 emission points, identified in paragraph (c)(3) of... reference control technology or standard and the emissions allowed for the Group 1 emission point. Said...

40 CFR 1060.104 - What running loss emission control requirements apply?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What running loss emission control... STATIONARY EQUIPMENT Emission Standards and Related Requirements § 1060.104 What running loss emission control requirements apply? (a) Engines and equipment must meet running loss requirements as follows: (1...

40 CFR 1060.525 - How do I test fuel systems for diurnal emissions?

Code of Federal Regulations, 2010 CFR

2010-07-01

... fuel tanks, and volume-compensating air bags. (b) You may subtract your fuel tank's permeation...) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY... diurnal emission standard. (8) For emission control technologies that rely on a sealed fuel system, you...

40 CFR 1060.525 - How do I test fuel systems for diurnal emissions?

Code of Federal Regulations, 2011 CFR

2011-07-01

... fuel tanks, and volume-compensating air bags. (b) You may subtract your fuel tank's permeation...) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY... diurnal emission standard. (8) For emission control technologies that rely on a sealed fuel system, you...

40 CFR 1039.801 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... operation in water. Auxiliary emission-control device means any element of design that senses temperature... suppression operations. Emission-control system means any device, system, or element of design that controls... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Definitions...

Design and field demonstration of a low-NOx burner for TEOR (thermally enhanced oil recovery) steamers

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

England, G.C.; Kwan, Y.; Payne, R.

1984-10-01

The paper discusses a program that addresses the need for advanced NOx control technology for thermally enhanced oil recovery (TEOR) steam generators. A full-scale (60 million Btu/hr) burner system has been developed and tested, the concept for which was based on fundamental studies. Test results are included for full-scale burner performance in an experimental test furnace, and in a field-operating steam generator which was subsequently retrofitted in a Kern County, California, oilfield. (NOTE: NOx control techniques including low-NOx burners, postflame NH/sub 3/ injection, or other postflame treatment methods--e.g., selective catalytic reduction--have been considered in order to comply with regulations. Themore » level of NOx control required to meet both growth and air quality goals has typically been difficult to achieve with available technology while maintaining acceptable CO and particulate emissions as well as practical flame conditions within the steamer.)« less

Experiments in charge control at geosynchronous orbit - ATS-5 and ATS-6

NASA Technical Reports Server (NTRS)

Olsen, R. C.

1985-01-01

In connection with existing theoretical concepts, it was difficult to explain the negative potentials found in sunlight, first on Applied Technology Satellite-5 (ATS-5) and then on ATS-6. The problem became important when an association between spacecraft charging and anomalies in spacecraft behavior was observed. A study of daylight charging phenomena on ATS-6 was conducted, and an investigation was performed with the objective to determine effective methods of charge control, taking into account the feasibility to utilize the ATS-5 and ATS-6 ion engines as current sources. In the present paper, data and analysis for the ion engine experiments on ATS-5 and ATS-6 are presented. It is shown that electron emission from a satellite with insulating surfaces is not an effective method of charge control because the increase in differential charging which results limits the effectiveness of electron emitters and increases the possibility of electrostatic discharges between surfaces at different potentials.

Guest Editorial Introduction to the Special Issue on 'Advanced Signal Processing Techniques and Telecommunications Network Infrastructures for Smart Grid Analysis, Monitoring, and Management'

DOE PAGES

Bracale, Antonio; Barros, Julio; Cacciapuoti, Angela Sara; ...

2015-06-10

Electrical power systems are undergoing a radical change in structure, components, and operational paradigms, and are progressively approaching the new concept of smart grids (SGs). Future power distribution systems will be characterized by the simultaneous presence of various distributed resources, such as renewable energy systems (i.e., photovoltaic power plant and wind farms), storage systems, and controllable/non-controllable loads. Control and optimization architectures will enable network-wide coordination of these grid components in order to improve system efficiency and reliability and to limit greenhouse gas emissions. In this context, the energy flows will be bidirectional from large power plants to end users andmore » vice versa; producers and consumers will continuously interact at different voltage levels to determine in advance the requests of loads and to adapt the production and demand for electricity flexibly and efficiently also taking into account the presence of storage systems.« less

Harvesting Electricity From Wasted Heat

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

Schwede, Jared

Scientists as SLAC National Laboratory explain the concept, Photon Enhanced Thermionic Emission (PETE), and how this process can capture more energy from photovoltaic panels by harnessing heat energy from sunlight.

Harvesting Electricity From Wasted Heat

ScienceCinema

Schwede, Jared

2018-01-16

Scientists as SLAC National Laboratory explain the concept, Photon Enhanced Thermionic Emission (PETE), and how this process can capture more energy from photovoltaic panels by harnessing heat energy from sunlight.

Cosmic Star–Forming Gas as seen from the Milky Way

NASA Astrophysics Data System (ADS)

Kauffmann, Jens

2018-01-01

We still struggle to understand the star formation properties of galaxies throughout the cosmos. Is star formation driven by the structure of galaxies? Or is it plainly controlled by the mass of dense gas that can be found in a galaxy?This poster presents results from several recent projects that deliver important insights on the global star formation activity of galaxies, based on detailed studies of star-forming regions in the Milky Way. First, the proberties of dense clouds in the Galactic Center are discussed, using data from interferometers likw ALMA. Second, the kinematics of Milky Way molecular clouds are discussed based on a variety of data sets. Third, the LEGO survey (Line Emission in Galaxy Observations) is discussed. This latter study challenges concepts of how dense gas in galaxies can be traced. In combination these studies deliver a fresh look at the various factors controlling how galaxies form stars.

40 CFR 1045.120 - What emission-related warranty requirements apply to me?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND... purchaser that the new engine, including all parts of its emission control system, meets two conditions: (1... generous than we require. The emission-related warranty for an engine may not be shorter than any published...

40 CFR 86.1803-01 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... operator prior to procurement. Auxiliary Emission Control Device (AECD) means any element of design which... components are those components which are designed primarily for emission control, or whose failure may... of design means any control system (i.e., computer software, electronic control system, emission...

40 CFR 86.1803-01 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... prior to procurement. Auxiliary Emission Control Device (AECD) means any element of design which senses... components are those components which are designed primarily for emission control, or whose failure may... of design means any control system (i.e., computer software, electronic control system, emission...

Control strategies for nitrous oxide emissions reduction on wastewater treatment plants operation.

PubMed

Santín, I; Barbu, M; Pedret, C; Vilanova, R

2017-11-15

The present paper focused on reducing greenhouse gases emissions in wastewater treatment plants operation by application of suitable control strategies. Specifically, the objective is to reduce nitrous oxide emissions during the nitrification process. Incomplete nitrification in the aerobic tanks can lead to an accumulation of nitrite that triggers the nitrous oxide emissions. In order to avoid the peaks of nitrous oxide emissions, this paper proposes a cascade control configuration by manipulating the dissolved oxygen set-points in the aerobic tanks. This control strategy is combined with ammonia cascade control already applied in the literature. This is performed with the objective to take also into account effluent pollutants and operational costs. In addition, other greenhouse gases emissions sources are also evaluated. Results have been obtained by simulation, using a modified version of Benchmark Simulation Model no. 2, which takes into account greenhouse gases emissions. This is called Benchmark Simulation Model no. 2 Gas. The results show that the proposed control strategies are able to reduce by 29.86% of nitrous oxide emissions compared to the default control strategy, while maintaining a satisfactory trade-off between water quality and costs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variable-cycle engines for supersonic cruising aircraft

NASA Technical Reports Server (NTRS)

Willis, E. A.; Welliver, A. D.

1976-01-01

The paper reviews the evolution and current status of selected recent variable-cycle engine (VCE) studies and describes how the results are influenced by airplane requirements. The engine/airplane studies are intended to identify promising VCE concepts, simplify their designs and identify the potential benefits in terms of aircraft performance. This includes range, noise, emissions, and the time and effort it may require to ensure technical readiness of sufficient depth to satisfy reasonable economic, performance, and environmental constraints. A brief overview of closely-related, on-going technology programs in acoustics and exhaust emissions is presented. It is shown that realistic technology advancements in critical areas combined with well matched aircraft and selected VCE concepts can lead to significantly improved economic and environmental performance relative to first-generation SST predictions.

US Steel Gary Works land based pushing emissions control

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

Randolph, R.A.; Price, C.A.

1983-01-01

To meet air quality standards at its Gary Works Coke Plant in Gary, Indiana, US Steel Corporation has installed pushing emission control systems for its five (77) oven, three meter coke batteries. The pushing emission control system consists of a hooded coke guide, single spot catch car, stationary emission capture ducts and remote gas cleaning baghouse with precoat capabilities. The system is providing effective emission control. In addition, there are corollary benefits. The operation of the single spot catch cars is easier and safer and coke moisture variables have been reduced.

40 CFR 1033.720 - Trading emission credits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Trading emission credits. 1033.720... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Averaging, Banking, and Trading for Certification § 1033.720 Trading emission credits. (a) Trading is the exchange of emission credits between certificate holders. You...

40 CFR 63.1332 - Emissions averaging provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... if pollution prevention measures are used to control five or more of the emission points included in... additional emission points if pollution prevention measures are used to control five or more of the emission... which emissions are reduced by pollution prevention measures shall be determined using the procedures...

40 CFR 63.1332 - Emissions averaging provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... if pollution prevention measures are used to control five or more of the emission points included in... additional emission points if pollution prevention measures are used to control five or more of the emission... which emissions are reduced by pollution prevention measures shall be determined using the procedures...

40 CFR 63.1332 - Emissions averaging provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... if pollution prevention measures are used to control five or more of the emission points included in... additional emission points if pollution prevention measures are used to control five or more of the emission... which emissions are reduced by pollution prevention measures shall be determined using the procedures...

40 CFR 1033.720 - Trading emission credits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Trading emission credits. 1033.720... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Averaging, Banking, and Trading for Certification § 1033.720 Trading emission credits. (a) Trading is the exchange of emission credits between certificate holders. You...

40 CFR 1033.720 - Trading emission credits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Trading emission credits. 1033.720... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Averaging, Banking, and Trading for Certification § 1033.720 Trading emission credits. (a) Trading is the exchange of emission credits between certificate holders. You...

40 CFR 1033.720 - Trading emission credits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Trading emission credits. 1033.720... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Averaging, Banking, and Trading for Certification § 1033.720 Trading emission credits. (a) Trading is the exchange of emission credits between certificate holders. You...

40 CFR 1033.720 - Trading emission credits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Trading emission credits. 1033.720... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Averaging, Banking, and Trading for Certification § 1033.720 Trading emission credits. (a) Trading is the exchange of emission credits between certificate holders. You...

On-road vehicle emission control in Beijing: past, present, and future.

PubMed

Wu, Ye; Wang, Renjie; Zhou, Yu; Lin, Bohong; Fu, Lixin; He, Kebin; Hao, Jiming

2011-01-01

Beijing, the capital of China, has experienced rapid motorization since 1990; a trend that is likely to continue. The growth in vehicles and the corresponding emissions create challenges to improving the urban air quality. In an effort to reduce the impact of vehicle emissions on urban air quality, Beijing has adopted a number of vehicle emission control strategies and policies since the mid 1990 s. These are classified into seven categories: (1) emission control on new vehicles; (2) emission control on in-use vehicles; (3) fuel quality improvements; (4) alternative-fuel and advanced vehicles; (5) economic policies; (6) public transport; and (7) temporal traffic control measures. Many have proven to be successful, such as the Euro emission standards, unleaded gasoline and low sulfur fuel, temporal traffic control measures during the Beijing Olympic Games, etc. Some, however, have been failures, such as the gasoline-to-LPG taxi retrofit program. Thanks to the emission standards for new vehicles as well as other controls, the fleet-average emission rates of CO, HC, NO(X), and PM(10) by each major vehicle category are decreasing over time. For example, gasoline cars decreased fleet-average emission factors by 12.5% for CO, 10.0% for HC, 5.8% for NO(X), and 13.0% for PM(10) annually since 1995, and such a trend is likely to continue. Total emissions for Beijing's vehicle fleet increased from 1995 to 1998. However, they show a clear and steady decrease between 1999 and 2009. In 2009, total emissions of CO, HC, NO(X), and PM(10) were 845,000 t, 121,000 t, 84,000 t, and 3700 t, respectively; with reductions of 47%, 49%, 47%, and 42%, relative to 1998. Beijing has been considered a pioneer in controlling vehicle emissions within China, similar to the role of California to the U.S. The continued rapid growth of vehicles, however, is challenging Beijing's policy-makers.

40 CFR 1054.105 - What exhaust emission standards must my nonhandheld engines meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission family are designed to operate. You must meet the numerical emission standards for hydrocarbons in... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK...

40 CFR 1054.103 - What exhaust emission standards must my handheld engines meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission family are designed to operate. You must meet the numerical emission standards for hydrocarbons in... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK...

A PEMFC hybrid electric vehicle real time control system

NASA Astrophysics Data System (ADS)

Sun, Hongqiao

In recent years, environmental friendly technologies and alternative energy solutions have drawn a lot of public attentions due to global energy crisis and pollution issues. Fuel cell (FC), a technology invented almost at the same time as the internal combustion (IC) engine, is now the focus of the automotive industry again. The fuel cell vehicle (FCV) has zero emission and its efficiency is significantly higher than the conventional IC engine power vehicles. Among a variety of FCV technologies, proton exchange membrane (PEM) FC vehicle appears to be far more attractive and mature. The prototype PEMFC vehicle has been developed and demonstrated to the public by nearly all the major automotive manufacturers in recent years. However, to the interest of the public research, publications and documentations on the PEMFC vehicle technology are rarely available due to its proprietary nature, which essentially makes it a secured technology. This dissertation demonstrates a real world application of a PEMFC hybrid electric vehicle. Through presenting the vehicle design concept, developing the real time control system and generating generic operation principles, this dissertation targets at establishing the public knowledge base on this new technology. A complete PEMFC hybrid electric vehicle design, including vehicle components layout, process flow diagram, real time control system architecture, subsystem structures and control algorithms, is presented in order to help understand the whole vehicle system. The design concept is validated through the vehicle demonstration. Generic operating principles are established along with the validation process, which helps populate this emerging technology. Thereafter, further improvements and future research directions are discussed.

The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

NASA Astrophysics Data System (ADS)

Firmansyah; Aziz, A. R. A.; Heikal, M. R.

2015-12-01

The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer

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

Hellesen, C.; Skiba, M., E-mail: mateusz.skiba@physics.uu.se; Dzysiuk, N.

2014-11-15

The fuel ion ratio n{sub t}/n{sub d} is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., n{sub t}/n{sub d} = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands thatmore » a DT spectrometer has to fulfill to be able to determine n{sub t}/n{sub d} with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.« less

Confining metal-halide perovskites in nanoporous thin films

PubMed Central

Demchyshyn, Stepan; Roemer, Janina Melanie; Groiß, Heiko; Heilbrunner, Herwig; Ulbricht, Christoph; Apaydin, Dogukan; Böhm, Anton; Rütt, Uta; Bertram, Florian; Hesser, Günter; Scharber, Markus Clark; Sariciftci, Niyazi Serdar; Nickel, Bert; Bauer, Siegfried; Głowacki, Eric Daniel; Kaltenbrunner, Martin

2017-01-01

Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantum-confined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites directly within device-relevant architectures without the use of colloidal stabilization. We find significantly blue-shifted photoluminescence emission by reducing the pore size; normally infrared-emitting materials become visibly red, and green-emitting materials become cyan and blue. Confining perovskite nanocrystals within porous oxide thin films drastically increases photoluminescence stability because the templates auspiciously serve as encapsulation. We quantify the template-induced size of the perovskite crystals in nanoporous silicon with microfocus high-energy x-ray depth profiling in transmission geometry, verifying the growth of perovskite nanocrystals throughout the entire thickness of the nanoporous films. Low-voltage electroluminescent diodes with narrow, blue-shifted emission fabricated from nanocrystalline perovskites grown in embedded nanoporous alumina thin films substantiate our general concept for next-generation photonic devices. PMID:28798959

How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen

PubMed Central

Niinemets, Ülo; Sun, Zhihong

2015-01-01

Plant isoprene emissions have been modelled assuming independent controls by light, temperature and atmospheric [CO2]. However, the isoprene emission rate is ultimately controlled by the pool size of its immediate substrate, dimethylallyl diphosphate (DMADP), and isoprene synthase activity, implying that the environmental controls might interact. In addition, acclimation to growth [CO2] can shift the share of the control by DMADP pool size and isoprene synthase activity, and thereby alter the environmental sensitivity. Environmental controls of isoprene emission were studied in hybrid aspen (Populus tremula × Populus tremuloides) saplings acclimated either to ambient [CO2] of 380 μmol mol–1 or elevated [CO2] of 780 μmol mol–1. The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions. Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply. The optimum temperature for isoprene emission was higher at lower light, suggesting activation of alternative DMADP sinks at higher light. In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants. Nevertheless, DMADP pool size was still predicted to more strongly control isoprene emission at higher temperatures in elevated-[CO2]-grown plants. We argue that interactive environmental controls and acclimation to growth [CO2] should be incorporated in future isoprene emission models at the level of DMADP pool size. PMID:25399006

78 FR 5303 - Approval and Promulgation of Implementation Plans; State of Missouri; Control of Sulfur Emissions...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-25

... Promulgation of Implementation Plans; State of Missouri; Control of Sulfur Emissions From Stationary Boilers.... Louis nonattainment area by limiting sulfur dioxide (SO 2 ) emissions (a precursor pollutant to PM 2.5... stringency of the SIP. Missouri's revision adds 10 CSR 10- 5.570 Control of Sulfur Emissions from Stationary...

40 CFR 1054.801 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... of this part. Auxiliary emission control device means any element of design that senses temperature... continuous mixture of those fuels. Emission control system means any device, system, or element of design... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT...

40 CFR 1054.801 - What definitions apply to this part?

Code of Federal Regulations, 2011 CFR

2011-07-01

... of this part. Auxiliary emission control device means any element of design that senses temperature... continuous mixture of those fuels. Emission control system means any device, system, or element of design... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT...

40 CFR 1054.801 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... of this part. Auxiliary emission control device means any element of design that senses temperature... continuous mixture of those fuels. Emission control system means any device, system, or element of design... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT...

40 CFR 1054.801 - What definitions apply to this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... of this part. Auxiliary emission control device means any element of design that senses temperature... continuous mixture of those fuels. Emission control system means any device, system, or element of design... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT...

40 CFR 1054.801 - What definitions apply to this part?

Code of Federal Regulations, 2013 CFR

2013-07-01

... of this part. Auxiliary emission control device means any element of design that senses temperature... continuous mixture of those fuels. Emission control system means any device, system, or element of design... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT...

40 CFR 1048.205 - What must I include in my application?

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Certifying Engine...'s specifications and other basic parameters of the engine's design and emission controls. List the... each distinguishable engine configuration in the engine family. (b) Explain how the emission control...

40 CFR 1048.205 - What must I include in my application?

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Certifying Engine...'s specifications and other basic parameters of the engine's design and emission controls. List the... each distinguishable engine configuration in the engine family. (b) Explain how the emission control...

Evaluation of advanced combustion concepts for dry NO sub x suppression with coal-derived, gaseous fuels

NASA Technical Reports Server (NTRS)

Beebe, K. W.; Symonds, R. A.; Notardonato, J. J.

1982-01-01

The emissions performance of a rich lean combustor (developed for liquid fuels) was determined for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf (7.0 to 10.3 MJ/NCM). The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher. NOx generation from NH3 is significant at ammonia concentrations significantly less than 0.5%. These levels may occur depending on fuel gas cleanup system design. CO emissions, combustion efficiency, smoke and other operational performance parameters were satisfactory. A test was completed with a catalytic combustor concept with petroleum distillate fuel. Reactor stage NOx emissions were low (1.4g NOx/kg fuel). CO emissions and combustion efficiency were satisfactory. Airflow split instabilities occurred which eventually led to test termination.

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

PubMed

Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

2017-01-01

The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

PM, NOx and butane emissions from on-road vehicle fleets in Hong Kong and their implications on emission control policy

NASA Astrophysics Data System (ADS)

Ning, Zhi; Wubulihairen, Maimaitireyimu; Yang, Fenhuan

2012-12-01

Vehicular emissions are the major sources of air pollution in urban areas. For metropolitan cities with large population working and living in environments with direct traffic impact, emission control is of great significance to protect public health. Implementation of more stringent emission standards, retrofitting fleet with emission control devices and switching to clearer fuel has been commonly practiced in different cities including Hong Kong. The present study employed a new plume chasing method for effective and quick evaluation of on-road fleet emission factors of particulate matter (PM), nitrogen oxides (NOx), and butane from heavy duty diesel trucks, diesel buses and liquefied petroleum gas (LPG) vehicles. The results showed distinct profiles of the emissions from different fleets with excessive butane emissions from LPG fleet and contrasting PM and NOx emissions from diesel trucks and buses fleets. A cross comparison was also made with emission data from other cities and from historic local studies. The implications of the observed difference on the effectiveness of emission control measures and policy are discussed with recommendations of direction for future research and policy making.

Ducted fuel injection: A new approach for lowering soot emissions from direct-injection engines

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

Mueller, Charles J.; Nilsen, Christopher W.; Ruth, Daniel J.

Designers of direct-injection compression-ignition engines use a variety of strategies to improve the fuel/charge-gas mixture within the combustion chamber for increased efficiency and reduced pollutant emissions. Strategies include the use of high fuel-injection pressures, multiple injections, small injector orifices, flow swirl, long-ignition-delay conditions, and oxygenated fuels. This is the first journal publication paper on a new mixing-enhancement strategy for emissions reduction: ducted fuel injection. The concept involves injecting fuel along the axis of a small cylindrical duct within the combustion chamber, to enhance the mixture in the autoignition zone relative to a conventional free-spray configuration (i.e., a fuel spray thatmore » is not surrounded by a duct). Finally, the results described herein, from initial proof-of-concept experiments conducted in a constant-volume combustion vessel, show dramatically lower soot incandescence from ducted fuel injection than from free sprays over a range of charge-gas conditions that are representative of those in modern direct-injection compression-ignition engines.« less

Ducted fuel injection: A new approach for lowering soot emissions from direct-injection engines

DOE PAGES

Mueller, Charles J.; Nilsen, Christopher W.; Ruth, Daniel J.; ...

2017-07-18

Designers of direct-injection compression-ignition engines use a variety of strategies to improve the fuel/charge-gas mixture within the combustion chamber for increased efficiency and reduced pollutant emissions. Strategies include the use of high fuel-injection pressures, multiple injections, small injector orifices, flow swirl, long-ignition-delay conditions, and oxygenated fuels. This is the first journal publication paper on a new mixing-enhancement strategy for emissions reduction: ducted fuel injection. The concept involves injecting fuel along the axis of a small cylindrical duct within the combustion chamber, to enhance the mixture in the autoignition zone relative to a conventional free-spray configuration (i.e., a fuel spray thatmore » is not surrounded by a duct). Finally, the results described herein, from initial proof-of-concept experiments conducted in a constant-volume combustion vessel, show dramatically lower soot incandescence from ducted fuel injection than from free sprays over a range of charge-gas conditions that are representative of those in modern direct-injection compression-ignition engines.« less

Evaluation of diesel fleet emissions and control policies from plume chasing measurements of on-road vehicles

NASA Astrophysics Data System (ADS)

Lau, Chui Fong; Rakowska, Agata; Townsend, Thomas; Brimblecombe, Peter; Chan, Tat Leung; Yam, Yat Shing; Močnik, Griša; Ning, Zhi

2015-12-01

Vehicle emissions are an important source of urban air pollution. Diesel fuelled vehicles, although constituting a relatively small fraction of fleet population in many cities, are significant contributors to the emission inventory due to their often long mileage for goods and public transport. Recent classification of diesel exhaust as carcinogenic by the World Health Organization also raises attention to more stringent control of diesel emissions to protect public health. Although various mandatory and voluntary based emission control measures have been implemented in Hong Kong, there have been few investigations to evaluate if the fleet emission characteristics have met desired emission reduction objectives and if adoption of an Inspection/Maintenance (I/M) programme has been effective in achieving these objectives. The limitations are partially due to the lack of cost-effective approaches for the large scale characterisation of fleet based emissions to assess the effectiveness of control measures and policy. This study has used a plume chasing method to collect a large amount of on-road vehicle emission data of Hong Kong highways and a detailed analysis was carried out to provide a quantitative evaluation of the emission characteristics in terms of the role of high and super-emitters in total emission reduction, impact of after-treatment on the multi-pollutants reduction strategy and the trend of NO2 emissions with newer emission standards. The study revealed that not all the high-emitters are from those vehicles of older Euro emission standards. Meanwhile, there is clear evidence that high-emitters for one pollutant may not be a high-emitter for another pollutant. Multi-pollutant control strategy needs to be considered in the enactment of the emission control policy which requires more comprehensive retrofitting technological solutions and matching I/M programme to ensure the proper maintenance of fleets. The plume chasing approach used in this study also shows to be a useful approach for assessing city wide vehicle emission characteristics.

Sector Tests of a Low-NO(sub x), Lean, Direct- Injection, Multipoint Integrated Module Combustor Concept Conducted

NASA Technical Reports Server (NTRS)

Tacina, Robert R.; Wey, Chang-Lie; Laing, Peter; Mansour, Adel

2002-01-01

The low-emissions combustor development described is directed toward advanced high pressure aircraft gas-turbine applications. The emphasis of this research is to reduce nitrogen oxides (NOx) at high-power conditions and to maintain carbon monoxide and unburned hydrocarbons at their current low levels at low power conditions. Low-NOx combustors can be classified into rich-burn and lean-burn concepts. Lean-burn combustors can be further classified into lean-premixed-prevaporized (LPP) and lean direct injection (LDI) concepts. In both concepts, all the combustor air, except for liner cooling flow, enters through the combustor dome so that the combustion occurs at the lowest possible flame temperature. The LPP concept has been shown to have the lowest NOx emissions, but for advanced high-pressure-ratio engines, the possibility of autoignition or flashback precludes its use. LDI differs from LPP in that the fuel is injected directly into the flame zone, and thus, it does not have the potential for autoignition or flashback and should have greater stability. However, since it is not premixed and prevaporized, good atomization is necessary and the fuel must be mixed quickly and uniformly so that flame temperatures are low and NOx formation levels are comparable to those of LPP. The LDI concept described is a multipoint fuel injection/multiburning zone concept. Each of the multiple fuel injectors has an air swirler associated with it to provide quick mixing and a small recirculation zone for burning. The multipoint fuel injection provides quick, uniform mixing and the small multiburning zones provide for reduced burning residence time, resulting in low NOx formation. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers, and fuel manifold into a single element. The multipoint concept combustor was demonstrated in a 15 sector test. The configuration tested had 36 fuel injectors and fuel-air mixers that replaced two fuel injectors in a conventional dual-annular combustor. During tests, inlet temperatures were up to 870 K and inlet pressures were up to 5400 kPa. A correlation was developed that related the NOx emissions with the inlet temperature, inlet pressure, fuel-air ratio, and pressure drop. At low-power conditions, fuel staging was used so that high combustion efficiency was obtained with only one-fourth of the fuel injectors flowing. The test facility had optical access, and visual images showed the flame to be very short, approximately 25 mm long.

Low NOx, Lean Direct Wall Injection Combustor Concept Developed

NASA Technical Reports Server (NTRS)

Tacina, Robert R.; Wey, Changlie; Choi, Kyung J.

2003-01-01

The low-emissions combustor development at the NASA Glenn Research Center is directed toward advanced high-pressure aircraft gas turbine applications. The emphasis of this research is to reduce nitrogen oxides (NOx) at high-power conditions and to maintain carbon monoxide and unburned hydrocarbons at their current low levels at low-power conditions. Low-NOx combustors can be classified into rich burn and lean burn concepts. Lean burn combustors can be further classified into lean-premixed-prevaporized (LPP) and lean direct injection (LDI) combustors. In both concepts, all the combustor air, except for liner cooling flow, enters through the combustor dome so that the combustion occurs at the lowest possible flame temperature. The LPP concept has been shown to have the lowest NOx emissions, but for advanced high-pressure-ratio engines, the possibly of autoignition or flashback precludes its use. LDI differs from LPP in that the fuel is injected directly into the flame zone and, thus, does not have the potential for autoignition or flashback and should have greater stability. However, since it is not premixed and prevaporized, the key is good atomization and mixing of the fuel quickly and uniformly so that flame temperatures are low and NOx formation levels are comparable to those of LPP.

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 63.503 - Emissions averaging provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... used in conjunction with other controls for a Group 1 storage vessel, batch front-end process vent... will be allowed only for the increase in control after November 15, 1990. (2) Group 1 emission points... Group 1 emission points that are controlled to a level less stringent than the reference control...

40 CFR 89.106 - Prohibited controls.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Prohibited controls. 89.106 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Standards and Certification Provisions § 89.106 Prohibited controls. (a) An engine may not be equipped with an emission...

40 CFR 89.106 - Prohibited controls.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Prohibited controls. 89.106 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Standards and Certification Provisions § 89.106 Prohibited controls. (a) An engine may not be equipped with an emission...

40 CFR 89.106 - Prohibited controls.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Prohibited controls. 89.106 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Standards and Certification Provisions § 89.106 Prohibited controls. (a) An engine may not be equipped with an emission...

40 CFR 89.106 - Prohibited controls.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Prohibited controls. 89.106 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Standards and Certification Provisions § 89.106 Prohibited controls. (a) An engine may not be equipped with an emission...

40 CFR 89.106 - Prohibited controls.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Prohibited controls. 89.106 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Standards and Certification Provisions § 89.106 Prohibited controls. (a) An engine may not be equipped with an emission...

Multiple effects and uncertainties of emission control policies in China: Implications for public health, soil acidification, and global temperature.

PubMed

Zhao, Yu; McElroy, Michael B; Xing, Jia; Duan, Lei; Nielsen, Chris P; Lei, Yu; Hao, Jiming

2011-11-15

Policies to control emissions of criteria pollutants in China may have conflicting impacts on public health, soil acidification, and climate. Two scenarios for 2020, a base case without anticipated control measures and a more realistic case including such controls, are evaluated to quantify the effects of the policies on emissions and resulting environmental outcomes. Large benefits to public health can be expected from the controls, attributed mainly to reduced emissions of primary PM and gaseous PM precursors, and thus lower ambient concentrations of PM2.5. Approximately 4% of all-cause mortality in the country can be avoided (95% confidence interval: 1-7%), particularly in eastern and north-central China, regions with large population densities and high levels of PM2.5. Surface ozone levels, however, are estimated to increase in parts of those regions, despite NOX reductions. This implies VOC-limited conditions. Even with significant reduction of SO2 and NOX emissions, the controls will not significantly mitigate risks of soil acidification, judged by the exceedance levels of critical load (CL). This is due to the decrease in primary PM emissions, with the consequent reduction in deposition of alkaline base cations. Compared to 2005, even larger CL exceedances are found for both scenarios in 2020, implying that PM control may negate any recovery from soil acidification due to SO2 reductions. Noting large uncertainties, current polices to control emissions of criteria pollutants in China will not reduce climate warming, since controlling SO2 emissions also reduces reflective secondary aerosols. Black carbon emission is an important source of uncertainty concerning the effects of Chinese control policies on global temperature change. Given these conflicts, greater consideration should be paid to reconciling varied environmental objectives, and emission control strategies should target not only criteria pollutants but also species such as VOCs and CO2. Copyright © 2011 Elsevier B.V. All rights reserved.

CONTROLLING MULTIPLE EMISSIONS FROM COAL-FIRED POWER PLANTS

EPA Science Inventory

The paper presents and analyzes nine existing and novel control technologies designed to achieve multipollutant emissions reductions. It provides an evaluation of multipollutant emission control technologies that are potentially available for coal-fired power plants of 25 MW capa...

Concept for Mars Volcanic Emission Life Scout

NASA Technical Reports Server (NTRS)

2004-01-01

This artist's rendition depicts a concept for a Mars orbiter that would scrutinize the martian atmosphere for chemical traces of life or environments supportive of life that might be present anywhere on the planet.

The concept is named the Mars Volcanic Emission and Life Scout, or Marvel. It would equip a Mars orbiter with two types of instruments proven useful in studying Earth's atmosphere from Earth orbit. One, a solar occultation infrared spectrometer, would look sideways through Mars' atmosphere toward the setting or rising Sun for an extremely sensitive reading of what chemicals are in the air that sunlight passes through before hitting the instrument. The other, a submillimeter spectrometer would survey the atmosphere continuously, including during dust storms and polar night, to seek localized surface sources of the chemicals of interest. The infrared spectrometer has very high sensitivity for one chemical of great interest: methane, which is produced by many types of microbes, as well as by some volcanic sources. The submillimeter spectrometer has very high sensitivity for water vapor. Localized concentrations of water vapor in the atmosphere could identify places where subsurface water sources may be venting.

40 CFR 88.311-93 - Emissions standards for Inherently Low-Emission Vehicles.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.311-93 Emissions... fuel vapor emissions which are five or less total grams per test as measured by the current Federal... control devices (canister, purge system, etc.) related to control of evaporative emissions, the fuel vapor...

A UAV-based gas sensing system for detecting fugitive methane emissions

NASA Astrophysics Data System (ADS)

Hugenholtz, C.; Barchyn, T.; Myshak, S.; Bauer, J.

2016-12-01

Methane is one of the most prevalent greenhouse gases emitted by human activities and is a major component of government-led initiatives to reduce GHG emissions in Canada, the USA, and elsewhere. In light of growing demand for measurements and verification of atmospheric methane concentration across the oil and gas supply chain, an autonomous airborne gas sensing system was developed that combines a small UAV and a lightweight gas monitor. This paper outlines the technology, analytics, and presents data from a case study to demonstrate the proof of concept. The UAV is a fixed-wing (2.2 m wingspan), battery-operated platform, with a flight endurance of 80-120 minutes. The gas sensor onboard the UAV is a tunable diode laser absorption spectrometer that uses an integrated transmitter/receiver unit and a remote, passive retro-reflector. The transmitter is attached to one of the winglets, while the other is coated with reflective material. The total weight of the UAV and gas sensor is 4.3 kg. During flight, the system operates autonomously, acquiring averages of raw measurements at 1 Hz, with a recorded resolution of 0.0455 ppm. The onboard measurement and control unit (MCU) for the gas sensor is integrated with the UAV autopilot in order to provide time-stamped and geotagged concentration measurements, and to provide real-time flight adjustments when concentration exceeds a pre-determined threshold. The data are retrieved from the MCU when the mission is complete. In order to demonstrate the proof of concept, we present results from a case study and outline opportunities for translating the measurements into decision making.

MUNICIPAL WASTE COMBUSTION MULTIPOLLUTANT STUDY EMISSION TEST REPORT, MAINE ENERGY RECOVERY COMPANY, REFUSE DERIVED FUEL FACILITY, BIDDEFORD, MAINE - VOLUME III: APPENDICES G-N

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. Control efficiency of the SD/FF emission control system ...

MUNICIPAL WASTE COMBUSTION MULTIPOLLUTANT STUDY EMISSION TEST REPORT, MAINE ENERGY RECOVERY COMPANY, REFUSE DERIVED FUEL FACILITY, BIDDEFORD, MAINE - VOLUME II: APPENDICES A-F

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. Control efficiency of the SD/FF emission control system ...

Digital Semaphore: Tactical Implications of QR Code Optical Signaling for Fleet Communications

DTIC Science & Technology

2013-06-01

Emissions Control (EMCON) and Hazards of Electromagnetic Radiation to Ordnance (HERO) restrict the ability for Naval Vessels to communicate using...importance of visual communications methods is brought to light by discussing emissions control, hazards of electromagnetic radiation to ordnance , and...overview of emissions restrictions including Emissions Control (EMCON) and Hazards of Electromagnetic Radiation to Ordnance (HERO). Chapter VII is

Experimental Evaluation of a Low Emissions High Performance Duct Burner for Variable Cycle Engines (VCE)

NASA Technical Reports Server (NTRS)

Lohmann, R. P.; Mador, R. J.

1979-01-01

An evaluation was conducted with a three stage Vorbix duct burner to determine the performance and emissions characteristics of the concept and to refine the configuration to provide acceptable durability and operational characteristics for its use in the variable cycle engine (VCE) testbed program. The tests were conducted at representative takeoff, transonic climb, and supersonic cruise inlet conditions for the VSCE-502B study engine. The test stand, the emissions sampling and analysis equipment, and the supporting flow visualization rigs are described. The performance parameters including the fuel-air ratio, the combustion efficiency/exit temperature, thrust efficiency, and gaseous emissions calculations are defined. The test procedures are reviewed and the results are discussed.

Advanced electric propulsion research

NASA Technical Reports Server (NTRS)

Wilbur, Paul J.

1988-01-01

Results are presented which show that hollow cathodes can be operated on ammonia but that sustained operation in the high pressures where arcjet thrusters operate (of the order of 1000 Torr) is difficult to achieve. The concept of using contoured, fine wire meshes attached across the screen grid apertures in an ion thruster to effect control of the ion beam divergence is introduced. The concept is compared to conventional (free sheath) ion extraction and is shown to be potentially attractive. The performance related effects of changing the anode and cathode locations and of interchanging hollow cathode and refractory filament electron sources within an 8-cm diameter, argon, ring cusp ion thruster discharge chamber are examined. The effects induced in discharge chamber performance by changes in magnetic field strength and configuration and in propellant flow distribution are also measured. Results are presented in terms of changes in the parameters that describe the effectiveness of primary electron utilization and ion extraction into the beam. The apparatus and instrumentation used to study hollow cathode operation at high electron emission levels (of the order of 100 A) is described.

Boreal Forest Fire Cools Climate

NASA Astrophysics Data System (ADS)

Randerson, J. T.; Liu, H.; Flanner, M.; Chambers, S. D.; Harden, J. W.; Hess, P. G.; Jin, Y.; Mack, M. C.; Pfister, G.; Schuur, E. A.; Treseder, K. K.; Welp, L. R.; Zender, C. S.

2005-12-01

We report measurements, modeling, and analysis of carbon and energy fluxes from a boreal forest fire that occurred in interior Alaska during 1999. In the first year after the fire, ozone production, atmospheric aerosol loading, greenhouse gas emissions, soot deposition, and decreases in summer albedo contributed to a positive annual radiative forcing (RF). These effects were partly offset by an increase in fall, winter, and spring albedo from reduced canopy cover and increased exposure of snow-covered surfaces. The atmospheric lifetime of aerosols and ozone and are relatively short (days to months). The radiative effects of soot on snow are also attenuated rapidly from the deposition of fresh snow. As a result, a year after the fire, only two classes of RF mechanisms remained: greenhouse gas emissions and post-fire changes in surface albedo. Summer albedo increased rapidly in subsequent years and was substantially higher than unburned control areas (by more than 0.03) after 4 years as a result of grass and shrub establishment. Satellite measurements from MODIS of other interior Alaska burn scars provided evidence that elevated levels of spring and summer albedo (relative to unburned control areas) persisted for at least 4 decades after fire. In parallel, our chamber, eddy covariance, and biomass measurements indicated that the post-fire ecosystems switch from a source to a sink within the first decade. Taken together, the extended period of increased spring and summer albedo and carbon uptake of intermediate-aged stands appears to more than offset the initial warming pulse caused by fire emissions, when compared using the RF concept. This result suggests that management of forests in northern countries to suppress fire and preserve carbon sinks may have the opposite effect on climate as that intended.

76 FR 36917 - Clean Air Act Operating Permit Program; Petition for Objection to State Operating Permit for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-23

... business; (II) The Title V permit failed to provide for the control of mercury emissions, an air... Reasonably Available Control Technology for the control of carbon dioxide emissions or for mercury emissions...

Evaluation of particulate matter emissions from manganese alloy production using life-cycle assessment.

PubMed

Davourie, Julia; Westfall, Luke; Ali, Mohammed; McGough, Doreen

2017-01-01

Life-cycle assessments (LCAs) provide a wealth of industry data to assist in evaluating the environmental impacts of industrial processes and product supply chains. In this investigation, data from a recent LCA covering global manganese alloy production was used to evaluate sources of particulate matter (PM) emissions associated with the manganese alloy supply chain. The analysis is aimed at providing an empirical, industry-averaged breakdown of the contribution that processes and emissions controls have on total emissions, manganese releases and occupational exposure. The assessment shows that 66% of PM emissions associated with manganese production occur beyond manganese facilities. Direct or on-site emissions represent 34% of total PM and occur predominantly as disperse sources during mineral extraction and hauling, and as primary furnace emissions. The largest contribution of manganese-bearing PM at ground-level is associated with fugitive emissions from metal and slag tapping, casting, crushing and screening. The evaluation provides a high-level ranking of emissions by process area, to assist in identifying priority areas for industry-wide initiatives to reduce emissions and occupational exposure of manganese. The range of PM emission levels in industry indicate that further enhancements in PM emissions can be achieved by sharing of best practices in emissions controls, limiting furnace conditions which lead to by-passing of emissions controls and application of secondary emission controls to capture fugitive emissions during tapping and casting. The LCA approach to evaluating PM emissions underscores the important role that process optimization and resource efficiency have on reducing PM emissions throughout the manganese supply chain. Copyright © 2016. Published by Elsevier B.V.

How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

PubMed

Niinemets, Ülo; Sun, Zhihong

2015-02-01

Plant isoprene emissions have been modelled assuming independent controls by light, temperature and atmospheric [CO2]. However, the isoprene emission rate is ultimately controlled by the pool size of its immediate substrate, dimethylallyl diphosphate (DMADP), and isoprene synthase activity, implying that the environmental controls might interact. In addition, acclimation to growth [CO2] can shift the share of the control by DMADP pool size and isoprene synthase activity, and thereby alter the environmental sensitivity. Environmental controls of isoprene emission were studied in hybrid aspen (Populus tremula × Populus tremuloides) saplings acclimated either to ambient [CO2] of 380 μmol mol(-1) or elevated [CO2] of 780 μmol mol(-1). The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions. Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply. The optimum temperature for isoprene emission was higher at lower light, suggesting activation of alternative DMADP sinks at higher light. In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants. Nevertheless, DMADP pool size was still predicted to more strongly control isoprene emission at higher temperatures in elevated-[CO2]-grown plants. We argue that interactive environmental controls and acclimation to growth [CO2] should be incorporated in future isoprene emission models at the level of DMADP pool size. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

CarbonSat -Quantification of natural and man-made greenhouse gas surface fluxes from satellite observations of atmospheric CO2 and CH4 column amounts

NASA Astrophysics Data System (ADS)

Bovensmann, Heinrich; Buchwitz, M.; Burrows, J. P.; Notholt, J.; Bovensmann, H.; Reuter, M.; Trautmann, T.; Ehret, G.; Heimann, M.; Monks, P.; B&Ü, H.; Sch; Harding, R.; Quegan, S.; Rayner, P.; Breon, F. M.; Bergam-O Aschi, P.; Dittus, H. J.; Erzinger, J.; Crisp, D.

Surprisingly and in spite of their exceptional driving role in climate change, our knowledge about the variable sources and sinks of the greenhouse gases CO2 and CH4 is currently inadequate. For example, the ability of the Earth-atmosphere system to buffer increasing anthropogenic emissions into the atmosphere has large uncertainties and emissions from many sources (geo-logic, anthropogenic, biogenic) are to a large degree uncertain. An adequate knowledge of the sources and sinks of CO2 and CH4 and their response to a changing climate is a pre-requisite for the accurate prediction of the regional variation of the climate of our planet. CarbonSat is a new mission concept to quantify and monitor CO2 and CH4 sources and sinks at the regional to local scale. The data will allow a better understanding of the processes that control the Carbon Cycle dynamics and an independent estimate of local greenhouse gas emissions (fossil fuel, geological CO2 and CH4, etc.). This will be achieved by a unique combination of high spatial resolution passive and active compact remote sensing with inverse modeling techniques. CarbonSat will accurately measure column-averaged mixing ratios of CO2 and CH4, i.e., XCO2 and XCH4, at a spatial resolution of 2 x 2 km2 (500 km continuous swath) with 0.5 percent goal (1 percent threshold) single measurement precision and global coverage within 3-6 days. Beside the quantification of sources and sinks on the regional scale, one key and innovative aim of the CarbonSat mission is to go a step forward towards quantifying local emission hot spots (fossil fuel emissions by power plants, gas/oil production, geological sources etc.). The core sensor will be a compact Imaging NIR/SWIR spectrometer (SCIAMACHY, OCO her-itage) whose measurements yield global data sets of XCO2 and XCH4 with at least one order of magnitude higher number of cloud free measurements than GOSAT and OCO and one order of magnitude better spatial coverage than OCO, due to CarbonSat's 500 km swath continuous across track coverage with 2 x 2 km2 spatial resolution. Ideally, the imaging spectrometer will be accompanied by a compact CH4 Lidar, to derive complementary accurate XCH4 -especially in high northern latitudes -as well as information on clouds and vegetation height. The overall mission concept will be presented.

CarbonSat - Quantification of natural and man-made greenhouse gas surface fluxes from satellite observations of atmospheric CO2 and CH4 column amounts

NASA Astrophysics Data System (ADS)

Bovensmann, Heinrich; Buchwitz, Michael

2010-05-01

Surprisingly and in spite of their exceptional driving role in climate change, our knowledge about the variable sources and sinks of the greenhouse gases CO2 and CH4 is currently inadequate. For example, the ability of the Earth-atmosphere system to buffer increasing anthropogenic emissions into the atmosphere has large uncertainties and emissions from many sources (geologic, anthropogenic, biogenic) are to a large degree uncertain. An adequate knowledge of the sources and sinks of CO2 and CH4 and their response to a changing climate is a pre-requisite for the accurate prediction of the regional variation of the climate of our planet. CarbonSat is a new mission concept to quantify and monitor CO2 and CH4 sources and sinks at the regional to local scale. The data will allow a better understanding of the processes that control the Carbon Cycle dynamics and an independent estimate of local greenhouse gas emissions (fossil fuel, geological CO2 and CH4, etc.). This will be achieved by a unique combination of high spatial resolution passive and active compact remote sensing with inverse modeling techniques. CarbonSat will accurately measure column-averaged mixing ratios of CO2 and CH4, i.e., XCO2 and XCH4, at a spatial resolution of 2 x 2 km2 (500 km continuous swath) with 0.5% goal (1%, threshold) single measurement precision and global coverage within 3-6 days. Beside the quantification of sources and sinks on the regional scale, one key and innovative aim of the CarbonSat mission is to go a step forward towards quantifying local emission hot spots (fossil fuel emissions by power plants, gas/oil production, geological sources etc.). The core sensor will be a compact Imaging NIR/SWIR spectrometer (SCIAMACHY, OCO heritage) whose measurements yield global data sets of XCO2 and XCH4 with at least one order of magnitude higher number of cloud free measurements than GOSAT and OCO and one order of magnitude better spatial coverage than OCO, due to CarbonSat's 500 km swath continuous across track coverage with 2 x 2 km2 spatial resolution. Ideally, the imaging spectrometer will be accompanied by a compact CH4 Lidar, to derive complementary accurate XCH4 - especially in high northern latitudes - as well as information on clouds and vegetation height. The overall mission concept, the expected data quality and selected application areas will be presented.

In-vacuum sensors for the beamline components of the ITER neutral beam test facility.

PubMed

Dalla Palma, M; Pasqualotto, R; Sartori, E; Spagnolo, S; Spolaore, M; Veltri, P

2016-11-01

Embedded sensors have been designed for installation on the components of the MITICA beamline, the prototype ITER neutral beam injector (Megavolt ITER Injector and Concept Advancement), to derive characteristics of the particle beam and to monitor the component conditions during operation for protection and thermal control. Along the beamline, the components interacting with the particle beam are the neutralizer, the residual ion dump, and the calorimeter. The design and the positioning of sensors on each component have been developed considering the expected beam-surface interaction including non-ideal and off-normal conditions. The arrangement of the following instrumentation is presented: thermal sensors, strain gages, electrostatic probes including secondary emission detectors, grounding shunt for electrical currents, and accelerometers.

Transient Micromotors That Disappear When No Longer Needed.

PubMed

Chen, Chuanrui; Karshalev, Emil; Li, Jinxing; Soto, Fernando; Castillo, Roxanne; Campos, Isaac; Mou, Fangzhi; Guan, Jianguo; Wang, Joseph

2016-11-22

Transient self-destroyed micromotors that autonomously disappear in biological media at controlled rates upon completing their task, without leaving a toxic residue, are presented. The propulsion and degradation characteristics of the self-destroyed Mg/ZnO, Mg/Si, and Zn/Fe Janus micromotors and single-component Zn micromotors are described. The degradation of the Janus micromotors relies on the different corrosion rates of their core-shell components. Inductively coupled plasma optical emission spectrometry measurements are used to probe the time-dependent degradation of the different constituents of the micromotors. The toxicity of the transient micromotors is discussed toward their potential use in biomedical applications. This concept of transient micromotors offers considerable potential for diverse practical applications in the near future.

40 CFR 61.349 - Standards: Closed-vent systems and control devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emission Standard for Benzene Waste Operations § 61.349 Standards: Closed-vent systems and control devices... efficiency of 95 weight percent or greater, or shall recover or control the benzene emissions vented to it..., or shall recover or control the benzene emissions vented to it with an efficiency of 98 weight...

40 CFR 61.349 - Standards: Closed-vent systems and control devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emission Standard for Benzene Waste Operations § 61.349 Standards: Closed-vent systems and control devices... efficiency of 95 weight percent or greater, or shall recover or control the benzene emissions vented to it..., or shall recover or control the benzene emissions vented to it with an efficiency of 98 weight...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND... maintaining and using the engine, including the emission control system as described in this section. The... degradation in emission control for engines that do not have their fuel injectors replaced. (iii) You provide...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND... maintaining and using the engine, including the emission control system as described in this section. The... degradation in emission control for engines that do not have their fuel injectors replaced. (iii) You provide...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND... maintaining and using the engine, including the emission control system as described in this section. The... degradation in emission control for engines that do not have their fuel injectors replaced. (iii) You provide...

Automotive fuel economy and emissions program

NASA Technical Reports Server (NTRS)

Dowdy, M. W.; Baisley, R. L.

1978-01-01

Experimental data were generated to support an assessment of the relationship between automobile fuel economy and emissions control systems. Tests were made at both the engine and vehicle levels. Detailed investigations were made on cold-start emissions devices, exhaust gas recirculation systems, and air injection reactor systems. Based on the results of engine tests, an alternative emission control system and modified control strategy were implemented and tested in the vehicle. With the same fuel economy and NOx emissions as the stock vehicle, the modified vehicle reduced HC and CO emissions by about 20 percent. By removing the NOx emissions constraint, the modified vehicle demonstrated about 12 percent better fuel economy than the stock vehicle.

Environmentally Friendly Replacement of Mature 200 MW Coal-Fired Power Blocks with 2 Boilers Working on One 500 MW Class Steam Turbine Generator (2on1 Unit Concept)

NASA Astrophysics Data System (ADS)

Grzeszczak, Jan; Grela, Łukasz; Achter, Thomas

2017-12-01

The paper covers problems of the owners of a fleet of long-operated conventional power plants that are going to be decommissioned soon in result of failing to achieve new admissible emissions levels or exceeding pressure elements design lifetime. Energoprojekt-Katowice SA, Siemens AG and Rafako SA presents their joint concept of the solution which is a 2on1 concept - replacing two unit by two ultra-supercritical boilers feeding one turbine. Polish market has been taken as an example.

Evaluation of heat engine for hybrid vehicle application

NASA Technical Reports Server (NTRS)

Schneider, H. W.

1984-01-01

The status of ongoing heat-engine developments, including spark-ignition, compression-ignition, internal-combustion, and external-combustion engines is presented. The potential of engine concepts under consideration for hybrid vehicle use is evaluated, using self-imposed criteria for selection. The deficiencies of the engines currently being evaluated in hybrid vehicles are discussed. Focus is on recent research with two-stroke, rotary, and free-piston engines. It is concluded that these engine concepts have the most promising potential for future application in hybrid vehicles. Recommendations are made for analysis and experimentation to evaluate stop-start and transient emission behavior of recommended engine concepts.

What is the purpose of emission computed tomography in nuclear medicine

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

Phelps, M.E.

1977-01-01

ECT is a mathematical and physical concept, an instrument, a radionuclide tracer technique, a research procedure and it is certainly both an old (Kuhl began his work in the late fifties) and a new concept. It also has great and unique potential as a diagnostic technique. It is interesting that the basic principles of medical CT were exemplified and developed in Nuclear Medicine by Kuhl and coworkers and the concept of ''physiologic or function tomography'' provides a technique to advance the original charter of Nuclear Medicine in the use of radionuclides for the measure of metabolism and physiologic function.

40 CFR 86.206-94 - Equipment required; overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... tests. Exhaust from gasoline-fueled vehicles is tested for gaseous emissions using the Constant Volume Sampler (CVS) concept (§ 86.209). Equipment necessary and specifications appear in §§ 86.208 through 86...

40 CFR 63.4966 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2013 CFR

2013-07-01

... system and add-on control device operating limits during the performance test? 63.4966 Section 63.4966... outlet gas temperature is the maximum operating limit for your condenser. (e) Emission capture system... Emission Rate with Add-on Controls Option § 63.4966 How do I establish the emission capture system and add...

Development of rotorcraft interior noise control concepts. Phase 3: Development of noise control concepts

NASA Technical Reports Server (NTRS)

Yoerkie, Charles A.; Gintoli, P. J.; Ingraham, S. T.; Moore, J. A.

1986-01-01

The goal of this research is the understanding of helicopter internal noise mechanisms and the development, design, and testing of noise control concepts which will produce significant reductions in the acoustic environment to which passengers are exposed. The Phase 3 effort involved the identification and evaluation of current and advanced treatment concepts, including isolation of structure-borne paths. In addition, a plan was devised for the full-scale evaluation of an isolation concept. Specific objectives were as follows: (1) identification and characterization of various noise control concepts; (2) implementation of noise control concepts within the S-76 SEA (statistical energy analysis) model; (3) definition and evaluation of a preliminary acoustic isolation design to reduce structure-borne transmission of acoustic frequency main gearbox gear clash vibrations into the airframe; (4) formulation of a plan for the full-scale validation of the isolation concept; and (5) prediction of the cabin noise environment with various noise control concepts installed.

Novel chip coating approaches to improve white LED technology

NASA Astrophysics Data System (ADS)

Hartmann, Paul; Schweighart, Marko; Sommer, Christian; Wenzl, Franz-P.; Zinterl, Ernst; Hoschopf, Hans; Pachler, Peter; Tasch, Stefan

2008-02-01

Key market requirements for white LEDs, especially in the general lighting and automotive headlamp segments call for improved concepts and performance of white LEDs based on phosphor conversion. Major challenges are small emission areas, highest possible intensities, long-term color stability, and spatial homogeneity of color coordinates. On the other hand, the increasingly high radiation power of the blue LEDs poses problems for all involved materials. Various thick film coating technologies are widely used for applying the color conversion layer to the semiconductor chip. We present novel concepts based on Silicate phosphors with high performance in terms of spatial homogeneity of the emission and variability of the color temperature. Numerical calculation of the optical properties with the help of state-of-the-art simulation tools was used as a basis for the practical optimization of the layer geometries.

Light bulb heat exchanger for magnetohydrodynamic generator applications - Preliminary evaluation

NASA Technical Reports Server (NTRS)

Smith, J. M.; Hwang, C. C.; Seikel, G. R.

1974-01-01

The light-bulb heat-exchanger concept is investigated as a possible means of using a combustion heat source to supply energy to an inert gas MHD power generator system. In this concept, combustion gases flow through a central passage which consists of a duct with transparent walls through which heat is transferred by radiation to a radiation receiver which in turn heats the inert gas by convection. The effects of combustion-gas emissivity, transparent-wall-transmissivity, radiation-receiver emissivity, and the use of fins in the inert gas coolant passage are studied. The results indicate that inert gas outlet temperatures of 2500 K are possible for combustion temperatures of 3200 K and that sufficient energy can be transferred from the combustion gas to reduce its temperature to approximately 2000 K. At this temperature more conventional heat exchangers can be used.

DEGRADATION OF EMISSIONS CONTROL PERFORMANCE OF WOODSTOVES IN CRESTED BUTTE, CO

EPA Science Inventory

The report discusses the degradation of emissions control performance of woodstoves in Crested Butte, Colorado. Four seasons of field monitoring of EPA-certified woodstoves in and around Crested Butte has demonstrated some significant failures in emissions control performance. In...

40 CFR 1042.235 - Emission testing related to certification.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... The engine you provide must include appropriate manifolds, aftertreatment devices, electronic control...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Certifying Engine Families § 1042.235 Emission testing related to certification. This...

40 CFR 1042.235 - Emission testing related to certification.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... The engine you provide must include appropriate manifolds, aftertreatment devices, electronic control...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Certifying Engine Families § 1042.235 Emission testing related to certification. This...

40 CFR 1042.235 - Emission testing related to certification.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... The engine you provide must include appropriate manifolds, aftertreatment devices, electronic control...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Certifying Engine Families § 1042.235 Emission testing related to certification. This...

40 CFR 1042.235 - Emission testing related to certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... The engine you provide must include appropriate manifolds, aftertreatment devices, electronic control...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Certifying Engine Families § 1042.235 Emission testing related to certification. This...

40 CFR 1042.235 - Emission testing related to certification.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... The engine you provide must include appropriate manifolds, aftertreatment devices, electronic control...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Certifying Engine Families § 1042.235 Emission testing related to certification. This...

Development of emissions inventory and identification of sources for priority control in the middle reaches of Yangtze River Urban Agglomerations.

PubMed

Sun, Xiaowei; Cheng, Shuiyuan; Lang, Jianlei; Ren, Zhenhai; Sun, Chao

2018-06-01

This paper presents the first attempt to investigate the emission source control of the Middle Reaches of Yangtze River Urban Agglomerations (MRYRUA), one of the national urban agglomerations in China. An emission inventory of the MRYRUA was developed as inputs to the CAMx model based on county-level activity data obtained by full-coverage investigation and source-based spatial surrogates. A classification technology method for priority control of atmospheric emission sources was introduced and applied in the MRYRUA for the evaluation of the emission sources control on the region-scale and city-scale, respectively. The results demonstrated that the emission sources in the Hefei-centered urban agglomerations contributed the biggest on the mean PM 2.5 concentrations of the MRYRUA and should be taken the priority to control. The emission sources in the Ma'anshan city, Xiangtan city, Hefei city and Wuhan city were the bigger contributors on the mean PM 2.5 concentrations of the MRYRUA among the cities and should be taken the priority to control. In generally, emission sources in cities along the Yangtze River and the tributary should be given the special attention for the regional air quality target attainments. This study can give an understanding of Chinese emissions and provide a valuable preference to policy makers for finding effective mitigation measures and control strategies for reducing national and regional air pollution in China. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Thurmond, Kyle; Loparo, Zachary; Partridge, Jr., William P.

Here, a sensor was developed for simultaneous measurements of carbon monoxide (CO) and carbon dioxide (CO 2) fluctuations in internal combustion engine exhaust gases. This sensor utilizes low-cost and compact light-emitting diodes (LEDs) that emit in the 3–5 µm wavelength range. An affordable, fast response sensor that can measure these gases has a broad application that can lead to more efficient, fuel-flexible engines and regulation of harmful emissions. Light emission from LEDs is spectrally broader and more spatially divergent when compared to that of lasers, which presented many design challenges. Optical design studies addressed some of the non-ideal characteristics ofmore » the LED emissions. Measurements of CO and CO 2 were conducted using their fundamental absorption bands centered at 4.7 µm and 4.3 µm, respectively, while a 3.6 µm reference LED was used to account for scattering losses (due to soot, window deposits, etc.) common to the three measurement LEDs. Instrument validation and calibration was performed using a laboratory flow cell and bottled-gas mixtures. The sensor was able to detect CO 2 and CO concentration changes as small as 30 ppm and 400 ppm, respectively. Because of the many control and monitor species with infra-red absorption features, which can be measured using the strategy described, this work demonstrates proof of concept for a wider range of fast (250 Hz) and low-cost sensors for gas measurement and process monitoring.« less

Effectiveness of SO2 emission control policy on power plants in the Yangtze River Delta, China-post-assessment of the 11th Five-Year Plan.

PubMed

Tan, Jiani; Fu, Joshua S; Huang, Kan; Yang, Cheng-En; Zhuang, Guoshun; Sun, Jian

2017-03-01

Facing the air pollution problems in China, emission control strategies have been implemented within the framework of national Five-Year Plan (FYP). According to the lack of post-assessment studies in the literature, this study assessed the effectiveness of the SO 2 emission control policies on power plants after the 11th FYP (2006-2010) by modeling emission control scenarios. The idealized emission control policy (the PS90 scenario with assumption of 90% SO 2 emission reduction from power plants) could reduce the SO 2 and SO 4 2- concentrations by about 51 and 14%, respectively, over the Yangtze River Delta region. While the actual emission control condition (the P2010 scenario based on the actual emissions from power plants in 2010) demonstrated that the actual reduction benefits were 30% of SO 2 and 9% of SO 4 2- . On the city scale, the P2010 scenario imposed positive benefits on Shanghai, Nanjing, Nantong, and Hangzhou with SO 2 reductions of about 55, 12, 30, and 21%, respectively, while an 11% increase of SO 2 concentration was found in Ningbo. The number of days exceeding China's National Ambient Air Quality Standard of Class I daily SO 2 concentration was estimated to be 75, 52, 7, 77, and 40 days for Shanghai, Nanjing, Nantong, Ningbo, and Hangzhou under the real SO 2 control condition (P2010). The numbers could be decreased by 16, 11, 2, 21, and 11% if the control effect reaches the level of the PS90 scenario. This study serves as a scientific basis to design capable enforcement of emission control strategies in China in the future national plans.

Impact of emission control on regional air quality in the Pearl Delta River region, southern China

NASA Astrophysics Data System (ADS)

Wang, N.; Xuejiao, D.

2017-12-01

The Pearl River Delta (PRD) in China has been suffering from air quality issues and the government has implemented a series of strategies in controlling emissions. In an attempt to provide scientific support for improving air quality, the paper investigates the concerning past-to-present air quality data and assesses air quality resulting from emission control. Statistical data revealed that energy consumption doubled from 2004 to 20014 and vehicle usage increased significantly from 2006 to 2014. Due to the effect of control efforts, primary emission of SO2, NOx and PM2.5 decreased resulting in ambient concentrations of SO2, NO2 and PM10 decreased by 66%, 20% and 24%, respectively. However, O3 increased 19% because of the increase of VOC emission. A chemical transport model, the Community Multi-scale Air Quality, was employed to evaluate the responses of nitrate, ammonium, SOA, PM2.5 and O3 to changes in NOx, VOC and NH3 emissions. Three scenarios, a baseline scenario, a CAP scenario (control strength followed as past tendency), and a REF scenario (strict control referred to latest policy and plans), were conducted to investigate the responses and mechanisms. NOx controlling scenarios showed that NOx, nitrate and PM2.5 reduced by 1.8%, 0.7% and 0.2% under CAP and reduced by 7.2%, 1.8% and 0.3% under REF, respectively. The results indicated that reducing NOx emission caused the increase of atmospheric oxidizability, which might result in a compensation of PM2.5 due to the increase of nitrate or sulfate. NH3 controlling scenarios showed that nitrate was sensitive to NH3 emission in PRD, with nitrate decreased by 0 - 10.6% and 0 - 48% under CAP and REF, respectively. Since controlling NH3 emissions not only reduced ammonium but also significantly reduced nitrate, the implement of NH3 controlling strategy was highly suggested. The VOC scenarios revealed that though SOA was not the major component of PM2.5, controlling VOC emission might take effect in southwestern PRD where photochemical pollution usually occurred. Last but not least, the responses of O3 indicated that the PRD was generally VOC-sensitive, while the regime turned to NOx-sensitive in the afternoon, therefore controlling VOC emission could reduce the overall O3 and controlling NOx emission in the afternoon could reduce peak O3.

DOE Light Truck Clean Diesel (LTCD) Program Final Caterpillar Public Report Light Truck Clean Diesel Program

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

Eric Fluga

The US Department of Energy and Caterpillar entered a Cooperative Agreement to develop compression ignition engine technology suitable for the light truck/SUV market. Caterpillar, in collaboration with a suitable commercialization partner, developed a new Compression Ignition Direct Injection (CIDI) engine technology to dramatically improve the emissions and performance of light truck engines. The overall program objective was to demonstrate engine prototypes by 2004, with an order of magnitude emission reduction while meeting challenging fuel consumption goals. Program emphasis was placed on developing and incorporating cutting edge technologies that could remove the current impediments to commercialization of CIDI power sources inmore » light truck applications. The major obstacle to commercialization is emissions regulations with secondary concerns of driveability and NVH (noise, vibration and harshness). The target emissions levels were 0.05 g/mile NOx and 0.01 g/mile PM to be compliant with the EPA Tier 2 fleet average requirements of 0.07 g/mile and the CARB LEV 2 of 0.05 g/mile for NOx, both have a PM requirement of 0.01 g/mile. The program team developed a combustion process that fundamentally shifted the classic NOx vs. PM behavior of CIDI engines. The NOx vs. PM shift was accomplished with a form of Homogeneous Charge Compression Ignition (HCCI). The HCCI concept centers on appropriate mixing of air and fuel in the compression process and controlling the inception and rate of combustion through various means such as variable valve timing, inlet charge temperature and pressure control. Caterpillar has adapted an existing Caterpillar design of a single injector that: (1) creates the appropriate fuel and air mixture for HCCI, (2) is capable of a more conventional injection to overcome the low power density problems of current HCCI implementations, (3) provides a mixed mode where both the HCCI and conventional combustion are functioning in the same combustion cycle. Figure 1 illustrates the mixed mode injection system. Under the LTCD program Caterpillar developed a mixed mode injector for a multi-cylinder engine system. The mixed mode injection system represents a critical enabling technology for the implementation of HCCI. In addition, Caterpillar implemented variable valve system technology and air system technology on the multi-cylinder engine platform. The valve and air system technology were critical to system control. Caterpillar developed the combustion system to achieve a 93% reduction in NOx emissions. The resulting NOx emissions were 0.12 gm/mile NOx. The demonstrated emissions level meets the stringent Tier 2 Bin 8 requirement without NOx aftertreatment! However, combustion development alone was not adequate to meet the program goal of 0.05gm/mile NOx. To meet the program goals, an additional 60% NOx reduction technology will be required. Caterpillar evaluated a number of NOx reduction technologies to quantify and understand the NOx reduction potential and system performance implications. The NOx adsorber was the most attractive NOx aftertreatment option based on fuel consumption and NOx reduction potential. In spite of the breakthrough technology development conducted under the LTCD program there remains many significant challenges associated with the technology configuration. For HCCI, additional effort is needed to develop a robust control strategy, reduce the hydrocarbon emissions at light load condition, and develop a more production viable fuel system. Furthermore, the NOx adsorber suffers from cost, packaging, and durability challenges that must be addressed.« less

TEST REPORT OF MOBILE SOURCE EMISSIONS CONTROL DEVICES DONALDSON COMPANY INC.SERIES 6100 DIESEL OXIDATION CATALYST MUFFLER AND SPIRACLE CLOSED CRANKCASE FILTRATION SYSTEM

EPA Science Inventory

This report is on an environmental verification of the emissions characteristics of a Donaldson Corp. catalytic muffler and catalyic crankcase emissions control. It was found the systems reduced emissions.

40 CFR 1033.245 - Deterioration factors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Certifying Engine Families § 1033.245 Deterioration factors... deterioration factors that predict emission increases over the useful life of a locomotive or locomotive engine... the difference between exhaust emissions at the end of the useful life and exhaust emissions at the...

40 CFR 1033.245 - Deterioration factors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Certifying Engine Families § 1033.245 Deterioration factors... deterioration factors that predict emission increases over the useful life of a locomotive or locomotive engine... the difference between exhaust emissions at the end of the useful life and exhaust emissions at the...

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.

40 CFR 265.1090 - Recordkeeping requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... applicable to the facility. Except for air emission control equipment design documentation and information... the operating record for a minimum of 3 years. Air emission control equipment design documentation... explain: How use of the required air emission controls on the tanks would affect the tank design features...

40 CFR 265.1090 - Recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... applicable to the facility. Except for air emission control equipment design documentation and information... the operating record for a minimum of 3 years. Air emission control equipment design documentation... explain: How use of the required air emission controls on the tanks would affect the tank design features...

40 CFR 265.1090 - Recordkeeping requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... applicable to the facility. Except for air emission control equipment design documentation and information... the operating record for a minimum of 3 years. Air emission control equipment design documentation... explain: How use of the required air emission controls on the tanks would affect the tank design features...

Setting up the criteria and credit-awarding scheme for building interior material selection to achieve better indoor air quality.

PubMed

Niu, J L; Burnett, J

2001-06-01

Methods, standards, and regulations that are aimed to reduce indoor air pollution from building materials are critically reviewed. These are classified as content control and emission control. Methods and standards can be found in both of these two classes. In the regulation domain, only content control is enforced in some countries and some regions, and asbestos is the only building material that is banned for building use. The controlled pollutants include heavy metals, radon, formaldehyde, and volatile organic compounds (VOCs). Emission rate control based upon environment chamber testing is very much in the nature of voluntary product labeling and ranking, and this mainly targets formaldehyde and VOC emissions. It is suggested that radon emission from building materials should be subject to similar emission rate control. A comprehensive set criteria and credit-awarding scheme that encourages the use of low-emission building material is synthesized, and how this scheme can be practiced in building design is proposed and discussed.

Delay-feedback control strategy for reducing CO2 emission of traffic flow system

NASA Astrophysics Data System (ADS)

Zhang, Li-Dong; Zhu, Wen-Xing

2015-06-01

To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

Alternative control techniques document: NOx emissions from industrial/commercial/institutional (ICI) boilers

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

Not Available

1994-03-01

Industrial, commercial, and institutional (ICI) boilers have been identified as a category that emits more than 25 tons of oxides of nitrogen (NOx) per year. This alternative control techniques (ACT) document provides technical information for use by State and local agencies to develop and implement regulatory programs to control NOx emissions from ICI boilers. Additional ACT documents are being developed for other stationary source categories. Chapter 2 summarizes the findings of this study. Chapter 3 presents information on the ICI boiler types, fuels, operation, and industry applications. Chapter 4 discusses NOx formation and uncontrolled NOx emission factors. Chapter 5 coversmore » alternative control techniques and achievable controlled emission levels. Chapter 6 presents the cost and cost effectiveness of each control technique. Chapter 7 describes environmental and energy impacts associated with implementing the NOx control techniques. Finally, Appendices A through G provide the detailed data used in this study to evaluate uncontrolled and controlled emissions and the costs of controls for several retrofit scenarios.« less

40 CFR 63.3511 - What reports must I submit?

Code of Federal Regulations, 2013 CFR

2013-07-01

... report the beginning and ending dates you used each option. (v) If you used the emission rate without add-on controls or the emission rate with add-on controls compliance option (§ 63.3491(b) or (c)), the... the reporting period. If you used the emission rate with add-on controls option or the control...

40 CFR 63.3511 - What reports must I submit?

Code of Federal Regulations, 2011 CFR

2011-07-01

... report the beginning and ending dates you used each option. (v) If you used the emission rate without add-on controls or the emission rate with add-on controls compliance option (§ 63.3491(b) or (c)), the... the reporting period. If you used the emission rate with add-on controls option or the control...

VOCs emission characteristics and priority control analysis based on VOCs emission inventories and ozone formation potentials in Zhoushan

NASA Astrophysics Data System (ADS)

Wang, Qiaoli; Li, Sujing; Dong, Minli; Li, Wei; Gao, Xiang; Ye, Rongmin; Zhang, Dongxiao

2018-06-01

Zhoushan is an island city with booming tourism and service industry, but also has many developed VOCs and/or NOX emission industries. It is necessary to carry out regional VOCs and O3 pollution control in Zhoushan as the only new area owns the provincial economic and social administration rights. Anthropogenic VOCs emission inventories were built based on emission factor method and main emission sources were identified according to the emission inventories. Then, localized VOCs source profiles were built based on in-site sampling and referring to other studies. Furthermore, ozone formation potentials (OFPs) profiles were built through VOCs source profiles and maximum incremental reactivity (MIR) theory. At last, the priority control analysis results showed that industrial processes, especially surface coating, are the key of VOCs and O3 control. Alkanes were the most emitted group, accounting for 58.67%, while aromatics contributed the most to ozone production accounting for 69.97% in total OFPs. n-butane, m/p-xylene, i-pentane, n-decane, toluene, propane, n-undecane, o-xylene, methyl cyclohexane and ethyl benzene were the top 10 VOC species that should be preferentially controlled for VOCs emission control. However, m/p-xylene, o-xylene, ethylene, n-butane, toluene, propene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, ethyl benzene and 1,2,3-trimethyl benzene were the top 10 VOC species that required preferential control for O3 pollution control.

Inventory of U.S. 2012 dioxin emissions to atmosphere.

PubMed

Dwyer, Henri; Themelis, Nickolas J

2015-12-01

In 2006, the U.S. EPA published an inventory of dioxin emissions for the U.S. covering the period from 1987-2000. This paper is an updated inventory of all U.S. dioxin emissions to the atmosphere in the year 2012. The sources of emissions of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), collectively referred to in this paper as "dioxins", were separated into two classes: controlled industrial and open burning sources. Controlled source emissions decreased 95.5% from 14.0 kg TEQ in 1987 to 0.6 kg in 2012. Open burning source emissions increased from 2.3 kg TEQ in 1987 to 2.9 kg in 2012. The 2012 dioxin emissions from 53 U.S. waste-to-energy (WTE) power plants were compiled on the basis of detailed data obtained from the two major U.S. WTE companies, representing 84% of the total MSW combusted (27.4 million metric tons). The dioxin emissions of all U.S. WTE plants in 2012 were 3.4 g TEQ and represented 0.54% of the controlled industrial dioxin emissions, and 0.09% of all dioxin emissions from controlled and open burning sources. Copyright © 2015. Published by Elsevier Ltd.

Exhaust emission reduction for intermittent combustion aircraft engines

NASA Technical Reports Server (NTRS)

Moffett, R. N.

1979-01-01

Three concepts for optimizing the performance, increasing the fuel economy, and reducing exhaust emission of the piston aircraft engine were investigated. High energy-multiple spark discharge and spark plug tip penetration, ultrasonic fuel vaporization, and variable valve timing were evaluated individually. Ultrasonic fuel vaporization did not demonstrate sufficient improvement in distribution to offset the performance loss caused by the additional manifold restriction. High energy ignition and revised spark plug tip location provided no change in performance or emissions. Variable valve timing provided some performance benefit; however, even greater performance improvement was obtained through induction system tuning which could be accomplished with far less complexity.

An original traffic additional emission model and numerical simulation on a signalized road

NASA Astrophysics Data System (ADS)

Zhu, Wen-Xing; Zhang, Jing-Yu

2017-02-01

Based on VSP (Vehicle Specific Power) model traffic real emissions were theoretically classified into two parts: basic emission and additional emission. An original additional emission model was presented to calculate the vehicle's emission due to the signal control effects. Car-following model was developed and used to describe the traffic behavior including cruising, accelerating, decelerating and idling at a signalized intersection. Simulations were conducted under two situations: single intersection and two adjacent intersections with their respective control policy. Results are in good agreement with the theoretical analysis. It is also proved that additional emission model may be used to design the signal control policy in our modern traffic system to solve the serious environmental problems.

Intelligent emissions controller for substance injection in the post-primary combustion zone of fossil-fired boilers

DOEpatents

Reifman, Jaques; Feldman, Earl E.; Wei, Thomas Y. C.; Glickert, Roger W.

2003-01-01

The control of emissions from fossil-fired boilers wherein an injection of substances above the primary combustion zone employs multi-layer feedforward artificial neural networks for modeling static nonlinear relationships between the distribution of injected substances into the upper region of the furnace and the emissions exiting the furnace. Multivariable nonlinear constrained optimization algorithms use the mathematical expressions from the artificial neural networks to provide the optimal substance distribution that minimizes emission levels for a given total substance injection rate. Based upon the optimal operating conditions from the optimization algorithms, the incremental substance cost per unit of emissions reduction, and the open-market price per unit of emissions reduction, the intelligent emissions controller allows for the determination of whether it is more cost-effective to achieve additional increments in emission reduction through the injection of additional substance or through the purchase of emission credits on the open market. This is of particular interest to fossil-fired electrical power plant operators. The intelligent emission controller is particularly adapted for determining the economical control of such pollutants as oxides of nitrogen (NO.sub.x) and carbon monoxide (CO) emitted by fossil-fired boilers by the selective introduction of multiple inputs of substances (such as natural gas, ammonia, oil, water-oil emulsion, coal-water slurry and/or urea, and combinations of these substances) above the primary combustion zone of fossil-fired boilers.

40 CFR 1054.230 - How do I select emission families?

Code of Federal Regulations, 2012 CFR

2012-07-01

... control for engine operation, other than governing (mechanical or electronic). (9) The numerical level of... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT..., divide your product line into families of engines that are expected to have similar emission...

40 CFR 1054.230 - How do I select emission families?

Code of Federal Regulations, 2011 CFR

2011-07-01

... control for engine operation, other than governing (mechanical or electronic). (9) The numerical level of... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT..., divide your product line into families of engines that are expected to have similar emission...

40 CFR 1054.230 - How do I select emission families?

Code of Federal Regulations, 2013 CFR

2013-07-01

... control for engine operation, other than governing (mechanical or electronic). (9) The numerical level of... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT..., divide your product line into families of engines that are expected to have similar emission...

40 CFR 1054.230 - How do I select emission families?

Code of Federal Regulations, 2014 CFR

2014-07-01

... control for engine operation, other than governing (mechanical or electronic). (9) The numerical level of... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT..., divide your product line into families of engines that are expected to have similar emission...

40 CFR 86.092-2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...), general type of fuel system (i.e., carburetor or fuel injection), catalyst system (e.g., none, oxidization... control systems are emission control components or systems (and fuel metering systems) that have completed... emission control components or systems (and fuel metering systems) that do not qualify as proven emission...

40 CFR 86.092-2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...), general type of fuel system (i.e., carburetor or fuel injection), catalyst system (e.g., none, oxidization... control systems are emission control components or systems (and fuel metering systems) that have completed... emission control components or systems (and fuel metering systems) that do not qualify as proven emission...

40 CFR 86.092-2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...), general type of fuel system (i.e., carburetor or fuel injection), catalyst system (e.g., none, oxidization... control systems are emission control components or systems (and fuel metering systems) that have completed... emission control components or systems (and fuel metering systems) that do not qualify as proven emission...

Arrays of Bundles of Carbon Nanotubes as Field Emitters

NASA Technical Reports Server (NTRS)

Manohara, Harish; Bronkowski, Michael

2007-01-01

Experiments have shown that with suitable choices of critical dimensions, planar arrays of bundles of carbon nanotubes (see figure) can serve as high-current-density field emitter (cold-cathode) electron sources. Whereas some hot-cathode electron sources must be operated at supply potentials of thousands of volts, these cold-cathode sources generate comparable current densities when operated at tens of volts. Consequently, arrays of bundles of carbon nanotubes might prove useful as cold-cathode sources in miniature, lightweight electron-beam devices (e.g., nanoklystrons) soon to be developed. Prior to the experiments, all reported efforts to develop carbon-nanotube-based field-emission sources had yielded low current densities from a few hundred microamperes to a few hundred milliamperes per square centimeter. An electrostatic screening effect, in which taller nanotubes screen the shorter ones from participating in field emission, was conjectured to be what restricts the emission of electrons to such low levels. It was further conjectured that the screening effect could be reduced and thus emission levels increased by increasing the spacing between nanotubes to at least by a factor of one to two times the height of the nanotubes. While this change might increase the emission from individual nanotubes, it would decrease the number of nanotubes per unit area and thereby reduce the total possible emission current. Therefore, to maximize the area-averaged current density, it would be necessary to find an optimum combination of nanotube spacing and nanotube height. The present concept of using an array of bundles of nanotubes arises partly from the concept of optimizing the spacing and height of field emitters. It also arises partly from the idea that single nanotubes may have short lifetimes as field emitters, whereas bundles of nanotubes could afford redundancy so that the loss of a single nanotube would not significantly reduce the overall field emission.

Professional Training for TRADOC Environmental and Natural Resource Professionals. Volume 1. A Feasibility Study and Concept Plan for a University Without Walls

DTIC Science & Technology

1991-05-01

Overview of Environmental Laws and Regulations 24 NEPA Process and Environmental Audit and Assessment 27 Air Emissions 27 Hazardous Materials...25 5 Overview of Environmental Laws and Regulations Training-U.S. Army Context Training 26 6 NEPA Review Process and Environmental Audit and...and environmental audit /assessment 4. Air emissions 5. Hazardous materials and waste management a. Polychlorinated biphenyls (PCBs) b. Petroleum, oil

Experimental clean combustor program, phase 1

NASA Technical Reports Server (NTRS)

Bahr, D. W.; Gleason, C. C.

1975-01-01

Full annular versions of advanced combustor designs, sized to fit within the CF6-50 engine, were defined, manufactured, and tested at high pressure conditions. Configurations were screened, and significant reductions in CO, HC, and NOx emissions levels were achieved with two of these advanced combustor design concepts. Emissions and performance data at a typical AST cruise condition were also obtained along with combustor noise data as a part of an addendum to the basic program. The two promising combustor design approaches evolved in these efforts were the Double Annular Combustor and the Radial/Axial Combustor. With versions of these two basic combustor designs, CO and HC emissions levels at or near the target levels were obtained. Although the low target NOx emissions level was not obtained with these two advanced combustor designs, significant reductions were relative to the NOx levels of current technology combustors. Smoke emission levels below the target value were obtained.

Mercury emission trend influenced by stringent air pollutants regulation for coal-fired power plants in Korea

NASA Astrophysics Data System (ADS)

Pudasainee, Deepak; Kim, Jeong-Hun; Seo, Yong-Chil

2009-12-01

Regulatory control of mercury emission from anthropogenic sources has become a global concern in the recent past. Coal-fired power plants are one of the largest sources of anthropogenic mercury emission into the atmosphere. This paper summarizes the current reducing trend of mercury emission as co-beneficial effect by more stringent regulation changes to control primary air pollutants with introducing test results from the commercial coal-fired facilities and suggesting a guideline for future regulatory development in Korea. On average, mercury emission concentrations ranged 16.3-2.7 μg Sm -3, 2.4-1.1 μg Sm -3, 3.1-0.7 μg Sm -3 from anthracite coal-fired power plants equipped with electrostatic precipitator (ESP), bituminous coal-fired power plants with ESP + flue gas desulphurization (FGD) and bituminous coal-fired power plants with selective catalytic reactor (SCR) + cold side (CS) - ESP + wet FGD, respectively. Among the existing air pollution control devices, the best configuration for mercury removal in coal-fired power plants was SCR + CS - ESP + wet FGD, which were installed due to the stringent regulation changes to control primary air pollutants emission such as SO 2, NOx and dust. It was estimated that uncontrolled and controlled mercury emission from coal-fired power plants as 10.3 ton yr -1 and 3.2 ton yr -1 respectively. After the installation of ESP, FGD and SCR system, following the enforcement of the stringent regulation, 7.1 ton yr -1 of mercury emission has been reduced (nearly 69%) from coal-fired power plants as a co-benefit control. Based on the overall study, a sample guideline including emission limits were suggested which will be applied to develop a countermeasure for controlling mercury emission from coal-fired power plants.

Inequalities in Global Trade: A Cross-Country Comparison of Trade Network Position, Economic Wealth, Pollution and Mortality.

PubMed

Prell, Christina; Sun, Laixiang; Feng, Kuishuang; Myroniuk, Tyler W

2015-01-01

In this paper we investigate how structural patterns of international trade give rise to emissions inequalities across countries, and how such inequality in turn impact countries' mortality rates. We employ Multi-regional Input-Output analysis to distinguish between sulfur-dioxide (SO2) emissions produced within a country's boarders (production-based emissions) and emissions triggered by consumption in other countries (consumption-based emissions). We use social network analysis to capture countries' level of integration within the global trade network. We then apply the Prais-Winsten panel estimation technique to a panel data set across 172 countries over 20 years (1990-2010) to estimate the relationships between countries' level of integration and SO2 emissions, and the impact of trade integration and SO2 emission on mortality rates. Our findings suggest a positive, (log-) linear relationship between a country's level of integration and both kinds of emissions. In addition, although more integrated countries are mainly responsible for both forms of emissions, our findings indicate that they also tend to experience lower mortality rates. Our approach offers a unique combination of social network analysis with multiregional input-output analysis, which better operationalizes intuitive concepts about global trade and trade structure.

Premature deaths attributed to source-specific BC emissions in six urban US regions

NASA Astrophysics Data System (ADS)

Turner, Matthew D.; Henze, Daven K.; Capps, Shannon L.; Hakami, Amir; Zhao, Shunliu; Resler, Jaroslav; Carmichael, Gregory R.; Stanier, Charles O.; Baek, Jaemeen; Sandu, Adrian; Russell, Armistead G.; Nenes, Athanasios; Pinder, Rob W.; Napelenok, Sergey L.; Bash, Jesse O.; Percell, Peter B.; Chai, Tianfeng

2015-11-01

Recent studies have shown that exposure to particulate black carbon (BC) has significant adverse health effects and may be more detrimental to human health than exposure to PM2.5 as a whole. Mobile source BC emission controls, mostly on diesel-burning vehicles, have successfully decreased mobile source BC emissions to less than half of what they were 30 years ago. Quantification of the benefits of previous emissions controls conveys the value of these regulatory actions and provides a method by which future control alternatives could be evaluated. In this study we use the adjoint of the Community Multiscale Air Quality (CMAQ) model to estimate highly-resolved spatial distributions of benefits related to emission reductions for six urban regions within the continental US. Emissions from outside each of the six chosen regions account for between 7% and 27% of the premature deaths attributed to exposure to BC within the region. While we estimate that nonroad mobile and onroad diesel emissions account for the largest number of premature deaths attributable to exposure to BC, onroad gasoline is shown to have more than double the benefit per unit emission relative to that of nonroad mobile and onroad diesel. Within the region encompassing New York City and Philadelphia, reductions in emissions from large industrial combustion sources that are not classified as EGUs (i.e., non-EGU) are estimated to have up to triple the benefits per unit emission relative to reductions to onroad diesel sectors, and provide similar benefits per unit emission to that of onroad gasoline emissions in the region. While onroad mobile emissions have been decreasing in the past 30 years and a majority of vehicle emission controls that regulate PM focus on diesel emissions, our analysis shows the most efficient target for stricter controls is actually onroad gasoline emissions.

High-Efficiency Nitride-Base Photonic Crystal Light Sources

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

James Speck; Evelyn Hu; Claude Weisbuch

2010-01-31

The research activities performed in the framework of this project represent a major breakthrough in the demonstration of Photonic Crystals (PhC) as a competitive technology for LEDs with high light extraction efficiency. The goals of the project were to explore the viable approaches to manufacturability of PhC LEDS through proven standard industrial processes, establish the limits of light extraction by various concepts of PhC LEDs, and determine the possible advantages of PhC LEDs over current and forthcoming LED extraction concepts. We have developed three very different geometries for PhC light extraction in LEDs. In addition, we have demonstrated reliable methodsmore » for their in-depth analysis allowing the extraction of important parameters such as light extraction efficiency, modal extraction length, directionality, internal and external quantum efficiency. The information gained allows better understanding of the physical processes and the effect of the design parameters on the light directionality and extraction efficiency. As a result, we produced LEDs with controllable emission directionality and a state of the art extraction efficiency that goes up to 94%. Those devices are based on embedded air-gap PhC - a novel technology concept developed in the framework of this project. They rely on a simple and planar fabrication process that is very interesting for industrial implementation due to its robustness and scalability. In fact, besides the additional patterning and regrowth steps, the process is identical as that for standard industrially used p-side-up LEDs. The final devices exhibit the same good electrical characteristics and high process yield as a series of test standard LEDs obtained in comparable conditions. Finally, the technology of embedded air-gap patterns (PhC) has significant potential in other related fields such as: increasing the optical mode interaction with the active region in semiconductor lasers; increasing the coupling of the incident light into the active region of solar cells; increasing the efficiency of the phosphorous light conversion in white light LEDs etc. In addition to the technology of embedded PhC LEDs, we demonstrate a technique for improvement of the light extraction and emission directionality for existing flip-chip microcavity (thin) LEDs by introducing PhC grating into the top n-contact. Although, the performances of these devices in terms of increase of the extraction efficiency are not significantly superior compared to those obtained by other techniques like surface roughening, the use of PhC offers some significant advantages such as improved and controllable emission directionality and a process that is directly applicable to any material system. The PhC microcavity LEDs have also potential for industrial implementation as the fabrication process has only minor differences to that already used for flip-chip thin LEDs. Finally, we have demonstrated that achieving good electrical properties and high fabrication yield for these devices is straightforward.« less

26 CFR 1.1563-1 - Definition of controlled group of corporations and component members and related concepts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... and component members and related concepts. 1.1563-1 Section 1.1563-1 Internal Revenue INTERNAL... related concepts. (a) Controlled group of corporations—(1) In general—(i) Types of controlled groups. For...) Additional concepts used in applying the controlled group rules. (A) The term testing date means the date...

Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China.

PubMed

Wang, N; Lyu, X P; Deng, X J; Guo, H; Deng, T; Li, Y; Yin, C Q; Li, F; Wang, S Q

2016-12-15

To evaluate the impact of emission control measures on the air quality in the Pearl River Delta (PRD) region of South China, statistic data including atmospheric observations, emissions and energy consumptions during 2006-2014 were analyzed, and a Weather Research and Forecasting - Community Multi-scale Air Quality (WRF-CMAQ) model was used for various scenario simulations. Although energy consumption doubled from 2004 to 2014 and vehicle number significantly increased from 2006 to 2014, ambient SO 2 , NO 2 and PM 10 were reduced by 66%, 20% and 24%, respectively, mainly due to emissions control efforts. In contrast, O 3 increased by 19%. Model simulations of three emission control scenarios, including a baseline (a case in 2010), a CAP (a case in 2020 assuming control strength followed past control tendency) and a REF (a case in 2020 referring to the strict control measures based on recent policy/plans) were conducted to investigate the variations of air pollutants to the changes in NO x , VOCs and NH 3 emissions. Although the area mean concentrations of NO x , nitrate and PM 2.5 decreased under both NO x CAP (reduced by 1.8%, 0.7% and 0.2%, respectively) and NO x REF (reduced by 7.2%, 1.8% and 0.3%, respectively), a rising of PM 2.5 was found in certain areas as reducing NO x emissions elevated the atmospheric oxidizability. Furthermore, scenarios with NH 3 emission reductions showed that nitrate was sensitive to NH 3 emissions, with decreasing percentages of 0-10.6% and 0-48% under CAP and REF, respectively. Controlling emissions of VOCs reduced PM 2.5 in the southwestern PRD where severe photochemical pollution frequently occurred. It was also found that O 3 formation in PRD was generally VOCs-limited while turned to be NO x -limited in the afternoon (13:00-17:00), suggesting that cutting VOCs emissions would reduce the overall O 3 concentrations while mitigating NO x emissions in the afternoon could reduce the peak O 3 levels. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 59.625 - How do I select emission families?

Code of Federal Regulations, 2012 CFR

2012-07-01

... control strategy. (c) You may subdivide a group of containers that is identical under paragraph (b) of... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Certifying Emission Families... containers that are expected to have similar emission characteristics throughout the useful life. (b) Group...

40 CFR 59.625 - How do I select emission families?

Code of Federal Regulations, 2013 CFR

2013-07-01

... control strategy. (c) You may subdivide a group of containers that is identical under paragraph (b) of... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Certifying Emission Families... containers that are expected to have similar emission characteristics throughout the useful life. (b) Group...

40 CFR 59.625 - How do I select emission families?

Code of Federal Regulations, 2011 CFR

2011-07-01

... control strategy. (c) You may subdivide a group of containers that is identical under paragraph (b) of... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Certifying Emission Families... containers that are expected to have similar emission characteristics throughout the useful life. (b) Group...

40 CFR 59.625 - How do I select emission families?

Code of Federal Regulations, 2014 CFR

2014-07-01

... control strategy. (c) You may subdivide a group of containers that is identical under paragraph (b) of... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Certifying Emission Families... containers that are expected to have similar emission characteristics throughout the useful life. (b) Group...

40 CFR 59.625 - How do I select emission families?

Code of Federal Regulations, 2010 CFR

2010-07-01

... control strategy. (c) You may subdivide a group of containers that is identical under paragraph (b) of... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Certifying Emission Families... containers that are expected to have similar emission characteristics throughout the useful life. (b) Group...

40 CFR 1048.101 - What exhaust emission standards must my engines meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... my engines meet? 1048.101 Section 1048.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Emission Standards and Related Requirements § 1048.101 What exhaust emission standards must my engines meet...

40 CFR 63.4120 - What reports must I submit?

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission limitation (including any periods when emissions bypassed the add-on control device and were... emission reduction during the compliance period by emission capture systems and add-on control devices... of the CPMS. (5) The date of the latest CPMS certification or audit. (6) The date and time that each...

NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

NASA Technical Reports Server (NTRS)

Nguyen, Nhan

2010-01-01

This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

Future trends of global atmospheric antimony emissions from anthropogenic activities until 2050

NASA Astrophysics Data System (ADS)

Zhou, Junrui; Tian, Hezhong; Zhu, Chuanyong; Hao, Jiming; Gao, Jiajia; Wang, Yong; Xue, Yifeng; Hua, Shenbin; Wang, Kun

2015-11-01

This paper presents the scenario forecast of global atmospheric antimony (Sb) emissions from anthropogenic activities till 2050. The projection scenarios are built based on the comprehensive global antimony emission inventory for the period 1995-2010 which is reported in our previous study. Three scenarios are set up to investigate the future changes of global antimony emissions as well as their source and region contribution characteristics. Trends of activity levels specified as 5 primary source categories are projected by combining the historical trend extrapolation with EIA International energy outlook 2013, while the source-specific dynamic emission factors are determined by applying transformed normal distribution functions. If no major changes in the efficiency of emission control are introduced and keep current air quality legislations (Current Legislation scenario), global antimony emissions will increase by a factor of 2 between 2010 and 2050. The largest increase in Sb emissions is projected from Asia due to large volume of nonferrous metals production and waste incineration. In case of enforcing the pollutant emission standards (Strengthened Control scenario), global antimony emissions in 2050 will stabilize with that of 2010. Moreover, we can anticipate further declines in Sb emissions for all continents with the best emission control performances (Maximum Feasible Technological Reduction scenario). Future antimony emissions from the top 10 largest emitting countries have also been calculated and source category contributions of increasing emissions of these countries present significant diversity. Furthermore, global emission projections in 2050 are distributed within a 1° × 1°latitude/longitude grid. East Asia, Western Europe and North America present remarkable differences in emission intensity under the three scenarios, which implies that source-and-country specific control measures are necessary to be implemented for abating Sb emissions from varied continents and countries in the future.

Residual Effects of Fertilization History Increase Nitrous Oxide Emissions from Zero-N Controls: Implications for Estimating Fertilizer-Induced Emission Factors.

PubMed

LaHue, Gabriel T; van Kessel, Chris; Linquist, Bruce A; Adviento-Borbe, Maria Arlene; Fonte, Steven J

2016-09-01

Agricultural N fertilization is the dominant driver of increasing atmospheric nitrous oxide (NO) concentrations over the past half-century, yet there is considerable uncertainty in estimates of NO emissions from agriculture. Such estimates are typically based on the amount of N applied and a fertilizer-induced emission factor (EF), which is calculated as the difference in emissions between a fertilized plot and a zero-N control plot divided by the amount of N applied. A fertilizer-induced EF of 1% is currently recognized by the Intergovernmental Panel on Climate Change (IPCC) based on several studies analyzing published field measurements of NO emissions. Although many zero-N control plots used in these measurements received historical N applications, the potential for a residual impact of these inputs on NO emissions has been largely ignored and remains poorly understood. To address this issue, we compared NO emissions under laboratory conditions from soils sampled within zero-N control plots that had historically received N inputs versus soils from plots that had no N inputs for 20 yr. Historical N fertilization of zero-N control plots increased initial NO emissions by roughly one order of magnitude on average relative to historically unfertilized control plots. Higher NO emissions were positively correlated with extractable N and potentially mineralizable N. This finding suggests that accounting for fertilization history may help reduce the uncertainty associated with the IPCC fertilizer-induced EF and more accurately estimate the contribution of fertilizer N to agricultural NO emissions, although further research to demonstrate this relationship in the field is needed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Economic implications of incorporating emission controls to mitigate air pollutants emitted from a modeled hydrocarbon-fuel biorefinery in the United States

DOE PAGES

Bhatt, Arpit; Zhang, Yimin; Davis, Ryan; ...

2016-07-15

The implementation of the US Renewable Fuel Standard is expected to increase the construction and operation of new biofuel facilities. Allowing this industry to grow without adversely affecting air quality is an important sustainability goal sought by multiple stakeholders. However, little is known about how the emission controls potentially required to comply with air quality regulations might impact biorefinery cost and deployment strategies such as siting and sizing. In this study, we use a baseline design for a lignocellulosic hydrocarbon biofuel production process to assess how the integration of emission controls impacts the minimum fuel selling price (MFSP) of themore » biofuel produced. We evaluate the change in MFSP for two cases as compared to the baseline design by incorporating (i) emission controls that ensure compliance with applicable federal air regulations and (ii) advanced control options that could be used to achieve potential best available control technology (BACT) emission limits. Our results indicate that compliance with federal air regulations can be achieved with minimal impact on biofuel cost (~$0.02 per gasoline gallon equivalent (GGE) higher than the baseline price of $5.10 GGE -1). However, if air emissions must be further reduced to meet potential BACT emission limits, the cost could increase nontrivially. For example, the MFSP could increase to $5.50 GGE -1 by adopting advanced emission controls to meet potential boiler BACT limits. Finally, given tradeoffs among emission control costs, permitting requirements, and economies of scale, these results could help inform decisions about biorefinery siting and sizing and mitigate risks associated with air permitting.« less

24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Formaldehyde emission controls for certain wood products. 3280.308 Section 3280.308 Housing and Urban Development Regulations Relating to... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood...

24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Formaldehyde emission controls for certain wood products. 3280.308 Section 3280.308 Housing and Urban Development Regulations Relating to... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood...

24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Formaldehyde emission controls for certain wood products. 3280.308 Section 3280.308 Housing and Urban Development Regulations Relating to... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood...

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Turbocharger. (iii) Electronic engine control unit and its associated sensors and actuators. (iv) Particulate... emission control and whose function is not integral to the design and performance of the engine). (d... once before the low-hour emission test point. Any other engine, emission control system, or fuel system...

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Turbocharger. (iii) Electronic engine control unit and its associated sensors and actuators. (iv) Particulate... emission control and whose function is not integral to the design and performance of the engine). (d... once before the low-hour emission test point. Any other engine, emission control system, or fuel system...

40 CFR 89.109 - Maintenance instructions and minimum allowable maintenance intervals.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Turbocharger. (iii) Electronic engine control unit and its associated sensors and actuators. (iv) Particulate... emission control and whose function is not integral to the design and performance of the engine). (d... once before the low-hour emission test point. Any other engine, emission control system, or fuel system...

40 CFR 52.987 - Control of hydrocarbon emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control of hydrocarbon emissions. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Louisiana § 52.987 Control of hydrocarbon... compliance date of January 1, 1980. This shall result in an estimated hydrocarbon emission reduction of at...

40 CFR 52.987 - Control of hydrocarbon emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of hydrocarbon emissions. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Louisiana § 52.987 Control of hydrocarbon... compliance date of January 1, 1980. This shall result in an estimated hydrocarbon emission reduction of at...

24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Formaldehyde emission controls for certain wood products. 3280.308 Section 3280.308 Housing and Urban Development Regulations Relating to... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood...

24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Formaldehyde emission controls for certain wood products. 3280.308 Section 3280.308 Housing and Urban Development Regulations Relating to... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood...

40 CFR 63.4167 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2013 CFR

2013-07-01

... system and add-on control device operating limits during the performance test? 63.4167 Section 63.4167... Emission Rate with Add-on Controls Option § 63.4167 How do I establish the emission capture system and add-on control device operating limits during the performance test? During the performance test required...

Self-organized global control of carbon emissions

NASA Astrophysics Data System (ADS)

Zhao, Zhenyuan; Fenn, Daniel J.; Hui, Pak Ming; Johnson, Neil F.

2010-09-01

There is much disagreement concerning how best to control global carbon emissions. We explore quantitatively how different control schemes affect the collective emission dynamics of a population of emitting entities. We uncover a complex trade-off which arises between average emissions (affecting the global climate), peak pollution levels (affecting citizens’ everyday health), industrial efficiency (affecting the nation’s economy), frequency of institutional intervention (affecting governmental costs), common information (affecting trading behavior) and market volatility (affecting financial stability). Our findings predict that a self-organized free-market approach at the level of a sector, state, country or continent can provide better control than a top-down regulated scheme in terms of market volatility and monthly pollution peaks. The control of volatility also has important implications for any future derivative carbon emissions market.

Emission current control system for multiple hollow cathode devices

NASA Technical Reports Server (NTRS)

Beattie, John R. (Inventor); Hancock, Donald J. (Inventor)

1988-01-01

An emission current control system for balancing the individual emission currents from an array of hollow cathodes has current sensors for determining the current drawn by each cathode from a power supply. Each current sensor has an output signal which has a magnitude proportional to the current. The current sensor output signals are averaged, the average value so obtained being applied to a respective controller for controlling the flow of an ion source material through each cathode. Also applied to each controller are the respective sensor output signals for each cathode and a common reference signal. The flow of source material through each hollow cathode is thereby made proportional to the current drawn by that cathode, the average current drawn by all of the cathodes, and the reference signal. Thus, the emission current of each cathode is controlled such that each is made substantially equal to the emission current of each of the other cathodes. When utilized as a component of a multiple hollow cathode ion propulsion motor, the emission current control system of the invention provides for balancing the thrust of the motor about the thrust axis and also for preventing premature failure of a hollow cathode source due to operation above a maximum rated emission current.

A Noise and Emissions Assessment of the N3-X Transport

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.; Haller, William J.

2014-01-01

Analytical predictions of certification noise and exhaust emissions for NASA's N3-X - a notional, hybrid wingbody airplane - are presented in this paper. The N3-X is a 300-passenger concept transport propelled by an array of fans distributed spanwise near the trailing edge of the wingbody. These fans are driven by electric motors deriving power from twin generators driven by turboshaft engines. Turboelectric distributed hybrid propulsion has the potential to dramatically increase the propulsive efficiency of aircraft. The noise and exhaust emission estimates presented here are generated using NASA's conceptual design systems analysis tools with several key modifications to accommodate this unconventional architecture. These tools predict certification noise and the emissions of oxides of nitrogen by leveraging data generated from a recent analysis of the N3-X propulsion system.

Acoustic emission feedback control for control of boiling in a microwave oven

DOEpatents

White, Terry L.

1991-01-01

An acoustic emission based feedback system for controlling the boiling level of a liquid medium in a microwave oven is provided. The acoustic emissions from the medium correlated with surface boiling is used to generate a feedback control signal proportional to the level of boiling of the medium. This signal is applied to a power controller to automatically and continuoulsly vary the power applied to the oven to control the boiling at a selected level.

Infrared thermography as a diagnostic tool to indicate sick-house-syndrome: a case-study

NASA Astrophysics Data System (ADS)

Ljungberg, Sven-Ake

1996-03-01

Every third child and many adults in Sweden have allergic reactions caused by indoor environmental problems. A lot of buildings constructed during the building-boom period of 1950 - 1990 expose the sick-house-syndrome, due to built-in moisture problems and poor ventilation performance of the building. Leaky building construction, transport of humid air condensing on thermal bridges within the construction gives rise to a humid environment, and forms a base for a microbial deterioration process of organic materials, with emissions hazardous for human health. So far there are no universal and cost efficient techniques or methods developed which could be used to reveal the sick-house-syndrome. In this paper we present the results of a case-study of the sick-house-syndrome, and an investigation concept with a combination of different techniques and methods to detect and to map underlying factors that form the base for microbial activities. The concept includes mobile and indoor thermography, functional control of ventilation systems, tracer gas techniques for measurement of air flow exchange rate in different rooms, microbial investigation of emissions, field inspections within the building construction and the building envelope, and medical investigation of the health status of the people working in the building. Mobile thermography of the exterior facades has been performed with a longwave AGEMA THV 900, respectively THV 1000 infrared system, during the period December 1994 - June 1995, at different and similar weather and radiation conditions, and with the building pressurized at one accession. Indoor thermography has been performed with a shortwave AGEMA THV 470 system, for a selection of objects/surfaces with thermal deviations, indicated in thermograms from the different mobile thermographic surveys. Functional control was performed for the ventilation systems, and air flow rates were measured using tracer gas technique for a selection of rooms with different function, manload and demand of air flow. Field control inspections were performed partly from the inside and partly from the outside of the building. Microbial activities were investigated by traditional measurements of the emissions and contamination of indoor air, and by ocular inspections and laboratory tests of building materials. Despite the fact that the building studied has a complicated composition of surface materials, including glass, wood, steel and concrete panels, it was possible to indirectly indicate surface anomalies, related to microbial deterioration of organic materials, through mold and rot activities, due to in-exfiltration of humid air, causing moisture problems within the construction. The result from this case-study shows that thermography can become an important diagnostic tool in order to detect and map sick-house-syndromes. The project is to be continued.

Historical evaluation of vehicle emission control in Guangzhou based on a multi-year emission inventory

NASA Astrophysics Data System (ADS)

Zhang, Shaojun; Wu, Ye; Liu, Huan; Wu, Xiaomeng; Zhou, Yu; Yao, Zhiliang; Fu, Lixin; He, Kebin; Hao, Jiming

2013-09-01

The Guangzhou government adopted many vehicle emission control policies and strategies during the five-year preparation (2005-2009) to host the 2010 Asian Games. This study established a multi-year emission inventory for vehicles in Guangzhou during 2005-2009 and estimated the uncertainty in total vehicle emissions by taking the assumed uncertainties in fleet-average emission factors and annual mileage into account. In 2009, the estimated total vehicle emissions in Guangzhou were 313 000 (242 000-387 000) tons of CO, 60 900 (54 000-70 200) tons of THC, 65 600 (56 800-74 100) tons of NOx and 2740 (2100-3400) tons of PM10. Vehicle emissions within the urban area of Guangzhou were estimated to be responsible for ˜40% of total gaseous pollutants and ˜25% of total PM10 in the entire city. Although vehicle use intensity increased rapidly in Guangzhou during 2005-2009, vehicle emissions were estimated to have been reduced by 12% for CO, 21% for THC and 20% for PM10 relative to those in 2005. NOx emissions were estimated to have remained almost constant during this period. Compared to the "without control" scenario, 19% (15%-23%) of CO, 20% (18%-23%) of THC, 9% (8%-10%) of NOx and 16% (12%-20%) of PM10 were estimated to have been mitigated from a combination of the implementation of Euro III standards for light-duty vehicles (LDVs) and heavy-duty diesel vehicles and improvement of fuel quality. This study also evaluated several enhanced vehicle emission control actions taken recently. For example, the enhanced I/M program for LDVs was estimated to reduce 11% (9%-14%) of CO, 9% (8%-10%) of THC and 2% (2%-3%) of NOx relative to total vehicle emissions in 2009. Total emission reductions by temporary traffic controls for the Asian Games were estimated equivalent to 9% (7%-11%) of CO, 9% (8%-10%) of THC, 5% (5%-6%) of NOx and 10% (8%-13%) of PM10 estimated total vehicle emissions in 2009. Those controls are essential to further vehicle emission mitigation in Guangzhou required by the new National Ambient Air Quality Standards.

Distinguishing the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks in ;APEC Blue;

NASA Astrophysics Data System (ADS)

Gao, Meng; Liu, Zirui; Wang, Yuesi; Lu, Xiao; Ji, Dongsheng; Wang, Lili; Li, Meng; Wang, Zifa; Zhang, Qiang; Carmichael, Gregory R.

2017-10-01

Air quality are strongly influenced by both emissions and meteorological conditions. During the Asia Pacific Economic Cooperation (APEC) week (November 5-11, 2014), the Chinese government implemented unprecedented strict emission control measures in Beijing and surrounding provinces, and then a phenomenon referred to as ;APEC Blue; (rare blue sky) occurred. It is challenging to quantify the effectiveness of the implemented strict control measures solely based on observations. In this study, we use the WRF-Chem model to distinguish the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks during APEC week. In general, meteorological variables, PM2.5 concentrations and PM2.5 chemical compositions are well reproduced in Beijing. Positive weather conditions (lower temperature, lower relative humidity, higher wind speeds and enhanced boundary layer heights) play important roles in ;APEC Blue;. Applying strict emission control measures in Beijing and five surrounding provinces can only explain an average decrease of 17.7 μg/m3 (-21.8%) decreases in PM2.5 concentrations, roughly more than half of which is caused by emission controls that implemented in the five surrounding provinces (12.5 μg/m3). During the APEC week, non-local emissions contributed to 41.3% to PM2.5 concentrations in Beijing, and the effectiveness of implementing emission control measures hinges on dominant pathways and transport speeds. Besides, we also quantified the contribution of reduced aerosol feedbacks due to strict emission control measures in this study. During daytime, co-benefits of reduced aerosol feedbacks account for about 10.9% of the total decreases in PM2.5 concentrations in urban Beijing. The separation of contributions from aerosol absorption and scattering restates the importance of controlling BC to accelerate the effectiveness of aerosol pollution control.

Spatial patterns of mobile source particulate matter emissions-to-exposure relationships across the United States

NASA Astrophysics Data System (ADS)

Greco, Susan L.; Wilson, Andrew M.; Spengler, John D.; Levy, Jonathan I.

Assessing the public health benefits from air pollution control measures is assisted by understanding the relationship between mobile source emissions and subsequent fine particulate matter (PM 2.5) exposure. Since this relationship varies by location, we characterized its magnitude and geographic distribution using the intake fraction (iF) concept. We considered emissions of primary PM 2.5 as well as particle precursors SO 2 and NO x from each of 3080 counties in the US. We modeled the relationship between these emissions and total US population exposure to PM 2.5, making use of a source-receptor matrix developed for health risk assessment. For primary PM 2.5, we found a median iF of 1.2 per million, with a range of 0.12-25. Half of the total exposure was reached by a median distance of 150 km from the county where mobile source emissions originated, though this spatial extent varied across counties from within the county borders to 1800 km away. For secondary ammonium sulfate from SO 2 emissions, the median iF was 0.41 per million (range: 0.050-10), versus 0.068 per million for secondary ammonium nitrate from NO x emissions (range: 0.00092-1.3). The median distance to half of the total exposure was greater for secondary PM 2.5 (450 km for sulfate, 390 km for nitrate). Regression analyses using exhaustive population predictors explained much of the variation in primary PM 2.5 iF ( R2=0.83) as well as secondary sulfate and nitrate iF ( R2=0.74 and 0.60), with greater near-source contribution for primary than for secondary PM 2.5. We conclude that long-range dispersion models with coarse geographic resolution are appropriate for risk assessments of secondary PM 2.5 or primary PM 2.5 emitted from mobile sources in rural areas, but that more resolved dispersion models are warranted for primary PM 2.5 in urban areas due to the substantial contribution of near-source populations.

Diesel Locomotive Exhaust Emission Control and Abatement

DOT National Transportation Integrated Search

1972-06-01

Exhaust emissions from diesel locomotives are a product of engine design and combustion characteristics. These pollutants, control methods, and emissions reduction through engine maintenance and retrofittable equipment changes are discussed in this r...

Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

NASA Technical Reports Server (NTRS)

Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy; Dyson, Rodger; Felder, James L.

2017-01-01

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL (Technology Readiness Level) level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT - NASA’s Electric Aircraft Testbed) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST - Hybrid-Electric Integrated Systems Testbed) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

NASA Technical Reports Server (NTRS)

Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy; Dyson, Rodger; Felder, James L.

2017-01-01

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

Policy design and performance of emissions trading markets: an adaptive agent-based analysis.

PubMed

Bing, Zhang; Qinqin, Yu; Jun, Bi

2010-08-01

Emissions trading is considered to be a cost-effective environmental economic instrument for pollution control. However, the pilot emissions trading programs in China have failed to bring remarkable success in the campaign for pollution control. The policy design of an emissions trading program is found to have a decisive impact on its performance. In this study, an artificial market for sulfur dioxide (SO2) emissions trading applying the agent-based model was constructed. The performance of the Jiangsu SO2 emissions trading market under different policy design scenario was also examined. Results show that the market efficiency of emissions trading is significantly affected by policy design and existing policies. China's coal-electricity price system is the principal factor influencing the performance of the SO2 emissions trading market. Transaction costs would also reduce market efficiency. In addition, current-level emissions discharge fee/tax and banking mechanisms do not distinctly affect policy performance. Thus, applying emissions trading in emission control in China should consider policy design and interaction with other existing policies.

Experimental investigation of gasoline compression ignition combustion in a light-duty diesel engine

NASA Astrophysics Data System (ADS)

Loeper, C. Paul

Due to increased ignition delay and volatility, low temperature combustion (LTC) research utilizing gasoline fuel has experienced recent interest [1-3]. These characteristics improve air-fuel mixing prior to ignition allowing for reduced emissions of nitrogen oxides (NOx) and soot (or particulate matter, PM). Computational fluid dynamics (CFD) results at the University of Wisconsin-Madison's Engine Research Center (Ra et al. [4, 5]) have validated these attributes and established baseline operating parameters for a gasoline compression ignition (GCI) concept in a light-duty diesel engine over a large load range (3-16 bar net IMEP). In addition to validating these computational results, subsequent experiments at the Engine Research Center utilizing a single cylinder research engine based on a GM 1.9-liter diesel engine have progressed fundamental understanding of gasoline autoignition processes, and established the capability of critical controlling input parameters to better control GCI operation. The focus of this thesis can be divided into three segments: 1) establishment of operating requirements in the low-load operating limit, including operation sensitivities with respect to inlet temperature, and the capabilities of injection strategy to minimize NOx emissions while maintaining good cycle-to-cycle combustion stability; 2) development of novel three-injection strategies to extend the high load limit; and 3) having developed fundamental understanding of gasoline autoignition kinetics, and how changes in physical processes (e.g. engine speed effects, inlet pressure variation, and air-fuel mixture processes) affects operation, develop operating strategies to maintain robust engine operation. Collectively, experimental results have demonstrated the ability of GCI strategies to operate over a large load-speed range (3 bar to 17.8 bar net IMEP and 1300-2500 RPM, respectively) with low emissions (NOx and PM less than 1 g/kg-FI and 0.2 g/kg-FI, respectively), and low fuel consumption (gross indicated fuel consumption <200 g/kWh). [1] Dec, J. E., Yang, Y., and Dronniou, N., 2011, "Boosted HCCI - Controlling Pressure- Rise Rates for Performance Improvements using Partial Fuel Stratification with Conventional Gasoline," SAE Int. J. Engines, 4(1), pp. 1169-1189. [2] Kalghatgi, G., Hildingsson, L., and Johansson, B., 2010, "Low NO(x) and Low Smoke Operation of a Diesel Engine Using Gasolinelike Fuels," Journal of Engineering for Gas Turbines and Power-Transactions of the Asme, 132(9), p. 9. [3] Manente, V., Zander, C.-G., Johansson, B., Tunestal, P., and Cannella, W., 2010, "An Advanced Internal Combustion Engine Concept for Low Emissions and High Efficiency from Idle to Max Load Using Gasoline Partially Premixed Combustion," SAE International, 2010-01-2198. [4] Ra, Y., Loeper, P., Reitz, R., Andrie, M., Krieger, R., Foster, D., Durrett, R., Gopalakrishnan, V., Plazas, A., Peterson, R., and Szymkowicz, P., 2011, "Study of High Speed Gasoline Direct Injection Compression Ignition (GDICI) Engine Operation in the LTC Regime," SAE Int. J. Engines, 4(1), pp. 1412-1430. [5] Ra, Y., Loeper, P., Andrie, M., Krieger, R., Foster, D., Reitz, R., and Durrett, R., 2012, "Gasoline DICI Engine Operation in the LTC Regime Using Triple- Pulse Injection," SAE Int. J. Engines, 5(3), pp. 1109-1132.

Active 3D camera design for target capture on Mars orbit

NASA Astrophysics Data System (ADS)

Cottin, Pierre; Babin, François; Cantin, Daniel; Deslauriers, Adam; Sylvestre, Bruno

2010-04-01

During the ESA Mars Sample Return (MSR) mission, a sample canister launched from Mars will be autonomously captured by an orbiting satellite. We present the concept and the design of an active 3D camera supporting the orbiter navigation system during the rendezvous and capture phase. This camera aims at providing the range and bearing of a 20 cm diameter canister from 2 m to 5 km within a 20° field-of-view without moving parts (scannerless). The concept exploits the sensitivity and the gating capability of a gated intensified camera. It is supported by a pulsed source based on an array of laser diodes with adjustable amplitude and pulse duration (from nanoseconds to microseconds). The ranging capability is obtained by adequately controlling the timing between the acquisition of 2D images and the emission of the light pulses. Three modes of acquisition are identified to accommodate the different levels of ranging and bearing accuracy and the 3D data refresh rate. To come up with a single 3D image, each mode requires a different number of images to be processed. These modes can be applied to the different approach phases. The entire concept of operation of this camera is detailed with an emphasis on the extreme lighting conditions. Its uses for other space missions and terrestrial applications are also highlighted. This design is implemented in a prototype with shorter ranging capabilities for concept validation. Preliminary results obtained with this prototype are also presented. This work is financed by the Canadian Space Agency.

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

Bhatt, Arpit; Zhang, Yimin; Davis, Ryan

The implementation of the US Renewable Fuel Standard is expected to increase the construction and operation of new biofuel facilities. Allowing this industry to grow without adversely affecting air quality is an important sustainability goal sought by multiple stakeholders. However, little is known about how the emission controls potentially required to comply with air quality regulations might impact biorefinery cost and deployment strategies such as siting and sizing. In this study, we use a baseline design for a lignocellulosic hydrocarbon biofuel production process to assess how the integration of emission controls impacts the minimum fuel selling price (MFSP) of themore » biofuel produced. We evaluate the change in MFSP for two cases as compared to the baseline design by incorporating (i) emission controls that ensure compliance with applicable federal air regulations and (ii) advanced control options that could be used to achieve potential best available control technology (BACT) emission limits. Our results indicate that compliance with federal air regulations can be achieved with minimal impact on biofuel cost (~$0.02 per gasoline gallon equivalent (GGE) higher than the baseline price of $5.10 GGE -1). However, if air emissions must be further reduced to meet potential BACT emission limits, the cost could increase nontrivially. For example, the MFSP could increase to $5.50 GGE -1 by adopting advanced emission controls to meet potential boiler BACT limits. Finally, given tradeoffs among emission control costs, permitting requirements, and economies of scale, these results could help inform decisions about biorefinery siting and sizing and mitigate risks associated with air permitting.« less

A Robust High Current Density Electron Gun

NASA Astrophysics Data System (ADS)

Mako, F.; Peter, W.; Shiloh, J.; Len, L. K.

1996-11-01

Proof-of-principle experiments are proposed to validate a new concept for a robust, high-current density Pierce electron gun (RPG) for use in klystrons and high brightness electron sources for accelerators. This rugged, long-life electron gun avoids the difficulties associated with plasma cathodes, thermionic emitters, and field emission cathodes. The RPG concept employs the emission of secondary electrons in a transmission mode as opposed to the conventional mode of reflection, i.e., electrons exit from the back face of a thin negative electron affinity (NEA) material, and in the same direction as the incident beam. Current amplification through one stage of a NEA material could be over 50 times. The amplification is accomplished in one or more stages consisting of one primary emitter and one or more secondary emitters. The primary emitter is a low current density robust emitter (e.g., thoriated tungsten). The secondary emitters are thin NEA electrodes which emit secondary electrons in the same direction as the incident beam. Specific application is targeted for a klystron gun to be used by SLAC with a cold cathode at 30-40 amps/cm^2 output from the secondary emission stage, a ~2 μs pulse length, and ~200 pulses/second.

Experimental and Modeling Investigation of the Effect of Air Preheat on the Formation of NOx in an RQL Combustor

NASA Technical Reports Server (NTRS)

Samuelsen, G. S.; Brouwer, J.; Vardakas, M. A.; Holderman, J. D.

2012-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of oxides of nitrogen (NOx) in gas turbine systems. The success of this low-NOx combustor strategy is dependent upon the links between the formation of NOx, inlet air preheat temperature, and the mixing of the jet air and fuel-rich streams. Chemical equilibrium and kinetics modeling calculations and experiments were performed to further understand NOx emissions in an RQL combustor. The results indicate that as the temperature at the inlet to the mixing zone increases (due to preheating and/or operating conditions) the fuel-rich zone equivalence ratio must be increased to achieve minimum NOx formation in the primary zone of the combustor. The chemical kinetics model illustrates that there is sufficient residence time to produce NOx at concentrations that agree well with the NOx measurements. Air preheat was found to have very little effect on mixing, but preheating the air did increase NOx emissions significantly. By understanding the mechanisms governing NOx formation and the temperature dependence of key reactions in the RQL combustor, a strategy can be devised to further reduce NOx emissions using the RQL concept.

75 FR 64951 - Approval and Promulgation of Implementation Plans; Illinois; Voluntary Nitrogen Oxides Controls

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

... for regulations governing Nitrogen Oxides (NO X ) emission allowances granted for implementation of voluntary control of NO X emissions from sources other than those covered by other Illinois NO X emission..., which would have incorporated a rule governing NO X emission allowances (estimation and crediting of NO...

40 CFR 60.562-1 - Standards: Process emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Compound (VOC) Emissions from the Polymer Manufacturing Industry § 60.562-1 Standards: Process emissions... vent stream from a control device shall have car-sealed opened all valves in the vent system from the emission source to the control device and car-sealed closed all valves in vent system that would lead the...

Magnetorheological valve based actuator for improvement of passively controlled turbocharger system

NASA Astrophysics Data System (ADS)

Bahiuddin, I.; Mazlan, S. A.; Imaduddin, F.; Ubaidillah, Ichwan, B.

2016-03-01

Variable geometry turbochargers have been widely researched to fulfil the current engine stringent regulations. The passively controlled turbocharger (PCT) concept has been proposed to reduce energy consumption by utilizing the emission energy to move the actuator. However, it only covered a small range operating condition. Therefore, a magnetorheological(MR) Valve device, as typical smart material devices to enhance a passive device, is proposed to improve the PCT. Even though the benefits have been considered for the compactness and easiness to connect to an electrical system, the number of publications regarding the MR application within engine system is hard to be found. Therefore, this paper introduces a design of an MR Valve in a turbocharger. The main challenge is to make sure its capability to produce a sufficient total pressure drop. To overcome the challenge, its material properties, shape and pressure drop calculation has been analyzed to fulfil the requirement. Finally, to get a more understanding of actuator performance, the actuator response was simulated by treating the exhaust gas pressure as an input. It shows that the new MR actuator has a potential dynamic to improve the PCT controllability.

Streamers and their applications

NASA Astrophysics Data System (ADS)

Pemen, A. J. M.

2011-10-01

In this invited lecture we give an overview of our 15 years of experience on streamer plasma research. Efforts are directed to integrating the competence areas of plasma physics, pulsed power technology and chemical processing. The current status is the development of a large scale pulsed corona system for gas treatment. Applications on biogas conditioning, VOC removal, odor abatement and control of traffic emissions have been demonstrated. Detailed research on electrical and chemical processes resulted in a boost of efficiencies. Energy transfer efficiency to the plasma was raised to above 90%. Simultaneous improvement of the plasma chemistry resulted in a highly efficient radical generation: O-radical production up to 50% of the theoretical maximum has been achieved. A major challenge in pulsed power driven streamers is to unravel, understand and ultimately control the complex interactions between the transient plasma, electrical circuits, and process. Even more a challenge is to yield electron energies that fit activation energies of the process. We will discuss our ideas on adjusting pulsed power waveforms and plasma reactor settings to obtain more controlled catalytic processing: the ``Chemical Transistor'' concept.

Environmental assessment of NH3 injection for an industrial package boiler. Volume 2. Data supplement. Final report, January 1983-January 1984

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

Castaldini, C.; DeRosier, R.; Waterland, L.R.

1986-02-01

The report discusses emission results from comprehensive flue-gas sampling of a gas- and oil-fired industrial boiler equipped with Exxon's Thermal DeNOx Ammonia Injection Process for NOx reduction. Comprehensive emission measurements included continuous monitoring of flue gas emissions; source assessment sampling system (SASS) tests; EPA Method 5/17 for solid and condensible particulate emissions and ammonia emissions; controlled condensation system for SO2 and SO3; and N2O emission sampling. Ammonia injection at a NH3/NO molar ratio of 2.52 gave a NOx reduction of 41% from an uncontrolled level of 234 ppm to a controlled level of 137 ppm. NH3 emissions increased from 11more » ppm for the baseline to an average of 430 ppm for ammonia injection. Nitrous oxide, N2O, was reduced 68% from a 50 ppm baseline level to a 17 ppm controlled level. Total particulate emissions increased by an order of magnitude from a baseline of 17.7 ng/J to a controlled level of 182 ng/J.« less

Role of sectoral and multi-pollutant emission control strategies in improving atmospheric visibility in the Yangtze River Delta, China.

PubMed

Huang, Kan; Fu, Joshua S; Gao, Yang; Dong, Xinyi; Zhuang, Guoshun; Lin, Yanfen

2014-01-01

The Community Multi-scale Air Quality modeling system is used to investigate the response of atmospheric visibility to the emission reduction from different sectors (i.e. industries, traffic and power plants) in the Yangtze River Delta, China. Visibility improvement from exclusive reduction of NOx or VOC emission was most inefficient. Sulfate and organic aerosol would rebound if NOx emission was exclusively reduced from any emission sector. The most efficient way to improve the atmospheric visibility was proven to be the multi-pollutant control strategies. Simultaneous emission reductions (20-50%) on NOx, VOC and PM from the industrial and mobile sectors could result in 0.3-1.0 km visibility improvement. And the emission controls on both NOx (85%) and SO2 (90%) from power plants gained the largest visibility improvement of up to 4.0 km among all the scenarios. The seasonal visibility improvement subject to emission controls was higher in summer while lower in the other seasons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Policy interactions and underperforming emission trading markets in China.

PubMed

Zhang, Bing; Zhang, Hui; Liu, Beibei; Bi, Jun

2013-07-02

Emission trading is considered to be cost-effective environmental economic instrument for pollution control. However, the ex post analysis of emission trading program found that cost savings have been smaller and the trades fewer than might have been expected at the outset of the program. Besides policy design issues, pre-existing environmental regulations were considered to have a significant impact on the performance of the emission trading market in China. Taking the Jiangsu sulfur dioxide (SO2) market as a case study, this research examined the impact of policy interactions on the performance of the emission trading market. The results showed that cost savings associated with the Jiangsu SO2 emission trading market in the absence of any policy interactions were CNY 549 million or 12.5% of total pollution control costs. However, policy interactions generally had significant impacts on the emission trading system; the lone exception was current pollution levy system. When the model accounted for all four kinds of policy interactions, the total pollution control cost savings from the emission trading market fell to CNY 39.7 million or 1.36% of total pollution control costs. The impact of policy interactions would reduce 92.8% of cost savings brought by emission trading program.

40 CFR 63.4966 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2011 CFR

2011-07-01

... system and add-on control device operating limits during the performance test? 63.4966 Section 63.4966... outlet gas temperature is the maximum operating limit for your condenser. (e) Emission capture system... with Add-on Controls Option § 63.4966 How do I establish the emission capture system and add-on control...

40 CFR 63.4966 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2010 CFR

2010-07-01

... system and add-on control device operating limits during the performance test? 63.4966 Section 63.4966... outlet gas temperature is the maximum operating limit for your condenser. (e) Emission capture system... with Add-on Controls Option § 63.4966 How do I establish the emission capture system and add-on control...