Electrochemical enhancement of nitric oxide removal from simulated lean-burn engine exhaust via solid oxide fuel cells.

PubMed

Huang, Ta-Jen; Wu, Chung-Ying; Lin, Yu-Hsien

2011-07-01

A solid oxide fuel cell (SOFC) unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3)-Ce(0.9)Gd(0.1)O(1.95) as the cathode. The SOFC operation is performed at 600 °C with a cathode gas simulating the lean-burn engine exhaust and at various fixed voltage, at open-circuit voltage, and with an inert gas flowing over the anode side, respectively. Electrochemical enhancement of NO decomposition occurs when an operating voltage is generated; higher O(2) concentration leads to higher enhancement. Smaller NO concentration results in larger NO conversion. Higher operating voltage and higher O(2) concentration can lead to both higher NO conversion and lower fuel consumption. The molar rate of the consumption of the anode fuel can be very much smaller than that of NO to N(2) conversion. This makes the anode fuel consumed in the SOFC-DeNO(x) process to be much less than the equivalent amount of ammonia consumed in the urea-based selective catalytic reduction process. Additionally, the NO conversion increases with the addition of propylene and SO(2) into the cathode gas. These are beneficial for the application of the SOFC-DeNO(x) technology on treating diesel and other lean-burn engine exhausts.

Dynamically balanced fuel nozzle and method of operation

DOEpatents

Richards, George A.; Janus, Michael C.; Robey, Edward H.

2000-01-01

An apparatus and method of operation designed to reduce undesirably high pressure oscillations in lean premix combustion systems burning hydrocarbon fuels are provided. Natural combustion and nozzle acoustics are employed to generate multiple fuel pockets which, when burned in the combustor, counteract the oscillations caused by variations in heat release in the combustor. A hybrid of active and passive control techniques, the apparatus and method eliminate combustion oscillations over a wide operating range, without the use of moving parts or electronics.

Performance of a Model Rich Burn-quick Mix-lean Burn Combustor at Elevated Temperature and Pressure

NASA Technical Reports Server (NTRS)

Peterson, Christopher O.; Sowa, William A.; Samuelsen, G. S.

2002-01-01

As interest in pollutant emission from stationary and aero-engine gas turbines increases, combustor engineers must consider various configurations. One configuration of increasing interest is the staged, rich burn - quick mix - lean burn (RQL) combustor. This report summarizes an investigation conducted in a recently developed high pressure gas turbine combustor facility. The model RQL combustor was plenum fed and modular in design. The fuel used for this study is Jet-A which was injected from a simplex atomizer. Emission (CO2, CO, O2, UHC, NOx) measurements were obtained using a stationary exit plane water-cooled probe and a traversing water-cooled probe which sampled from the rich zone exit and the lean zone entrance. The RQL combustor was operated at inlet temperatures ranging from 367 to 700 K, pressures ranging from 200 to 1000 kPa, and combustor reference velocities ranging from 10 to 20 m/s. Variations were also made in the rich zone and lean zone equivalence ratios. Several significant trends were observed. NOx production increased with reaction temperature, lean zone equivalence ratio and residence time and decreased with increased rich zone equivalence ratio. NOx production in the model RQL combustor increased to the 0.4 power with increased pressure. This correlation, compared to those obtained for non-staged combustors (0.5 to 0.7), suggests a reduced dependence on NOx on pressure for staged combustors. Emissions profiles suggest that rich zone mixing is not uniform and that the rich zone contributes on the order of 16 percent to the total NOx produced.

Lean NOx catalysis for gasoline fueled European cars

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

NONE

1997-02-01

There is increasing interest in operating gasoline fueled passenger cars lean of the stoichiometric air/fuel (A/F) ratio to improve fuel economy. These types of engines will operate at lean A/F ratios while cruising at partial load, and return to stoichiometric or even rich conditions when more power is required. The challenge for the engine and catalyst manufacturer is to develop a system which will combine the high activity rates of a state-of-the-art three-way catalyst (TWC) with the ability to reduce nitrogen oxides (NOx) in the presence of excess oxygen. The objective is to achieve the future legislative limits (EURO III/IV)more » in the European Union. Recent developments in automotive pollution control catalysis show that the use of NOx adsorption materials is a suitable way to reduce NOx emissions of gasoline-fueled lean-burn engines. However, the primary task for the implementation of this technology in the European market will be to improve the catalyst`s high-temperature stability and to decrease its susceptibility to sulfur poisoning. Outlined here are results of a recent R and D program to achieve NOx reduction under lean-burn gasoline engine conditions. Model gas test results as well as engine bench data are used for discussion of the parameters which control NOx adsorption efficiency under various conditions.« less

Lean Mixture Engines Testing and Evaluation Program : Volume 3. Appendices.

DOT National Transportation Integrated Search

1975-01-01

This report is aimed at defining analytically and demonstrating experimentally the potential of the 'lean-burn concept.' Fuel consumption and emissions data are obtained on the engine dynamometer for the baseline engine, and two lean-burn configurati...

Lean Mixture Engines Testing and Evaluation Program : Volume 2. Comprehensive Discussion.

DOT National Transportation Integrated Search

1975-11-01

This report is aimed at defining analytically and demonstrating experimentally the potential of the 'lean-burn concept.' Fuel consumption and emissions data are obtained on the engine dynamometer for the baseline engine, and two lean-burn configurati...

Lean Mixture Engines Testing and Evaluation Program : Volume 1. Executive Summary.

DOT National Transportation Integrated Search

1975-01-01

This report is aimed at defining analytically and demonstrating experimentally the potential of the 'lean-burn concept'. Fuel consumption and emissions data are obtained on the engine dynamometer for the baseline engine, and two lean-burn configurati...

Apparatus and method for burning a lean, premixed fuel/air mixture with low NOx emission

DOEpatents

Kostiuk, Larry W.; Cheng, Robert K.

1996-01-01

An apparatus for enabling a burner to stably burn a lean fuel/air mixture. The burner directs the lean fuel/air mixture in a stream. The apparatus comprises an annular flame stabilizer; and a device for mounting the flame stabilizer in the fuel/air mixture stream. The burner may include a body having an internal bore, in which case, the annular flame stabilizer is shaped to conform to the cross-sectional shape of the bore, is spaced from the bore by a distance greater than about 0.5 mm, and the mounting device mounts the flame stabilizer in the bore. An apparatus for burning a gaseous fuel with low NOx emissions comprises a device for premixing air with the fuel to provide a lean fuel/air mixture; a nozzle having an internal bore through which the lean fuel/air mixture passes in a stream; and a flame stabilizer mounted in the stream of the lean fuel/air mixture. The flame stabilizer may be mounted in the internal bore, in which case, it is shaped and is spaced from the bore as just described. In a method of burning a lean fuel/air mixture, a lean fuel/air mixture is provided, and is directed in a stream; an annular eddy is created in the stream of the lean fuel/air mixture; and the lean fuel/air mixture is ignited at the eddy.

Low NOx heavy fuel combustor concept program

NASA Technical Reports Server (NTRS)

White, D. J.; Kubasco, A. J.

1982-01-01

Three simulated coal gas fuels based on hydrogen and carbon monoxide were tested during an experimental evaluation with a rich lean can combustor: these were a simulated Winkler gas, Lurgi gas and Blue Water gas. All three were simulated by mixing together the necessary pure component species, to levels typical of fuel gases produced from coal. The Lurgi gas was also evaluated with ammonia addition. Fuel burning in a rich lean mode was emphasized. Only the Blue Water gas, however, could be operated in such fashion. This showed that the expected NOx signature form could be obtained, although the absolute values of NOx were above the 75 ppm goals for most operating conditions. Lean combustion produced very low NOx well below 75 ppm with the Winkler and Lurgi gases. In addition, these low levels were not significantly impacted by changes in operating conditions.

LeRC in-house experimental research

NASA Technical Reports Server (NTRS)

Lyons, Valerie J.

1992-01-01

The topics covered include the following: LeRC in-house experimental research; combustion concepts; schedule for in-house experiments; lean premixed prevaporized combustion; comparisons of low NO(x) lean premixed/prevaporized data; rich burn/quick quench/lean burn (RQL); RQL combustion; fuel rich catalytic combustion; advanced diagnostics; and ceramic matrix liner test rig.

Chemical and toxicological properties of emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies

NASA Astrophysics Data System (ADS)

Yoon, Seungju; Hu, Shaohua; Kado, Norman Y.; Thiruvengadam, Arvind; Collins, John F.; Gautam, Mridul; Herner, Jorn D.; Ayala, Alberto

2014-02-01

Chemical and toxicological properties of emissions from compressed natural gas (CNG) fueled transit buses with stoichiometric combustion engines and three-way catalyst (TWC) exhaust control systems were measured using a chassis dynamometer testing facility and compared to the data from earlier CNG engine and exhaust control technologies. Gaseous and particulate matter emissions from buses with stoichiometric engines and TWC were significantly lower than the emissions from buses with lean-burn engines. Carbonyls and volatile organic compounds (VOCs) from buses with stoichiometric engines and TWC were lower by more than 99% compared to buses with lean-burn engines. Elemental and organic carbons (EC and OC), polycyclic aromatic hydrocarbons (PAHs), and trace elements from buses with stoichiometric engines and TWC were effectively controlled and significantly lower than the emissions from buses with lean-burn engines. Potential mutagenicity measured using a microsuspension modification of the Salmonella/microsome assay was lower by more than 99% for buses with stoichiometric engines and TWC, compared to buses with lean-burn engines and OxC.

The effect of incomplete fuel-air mixing on the lean blowout limit, lean stability limit and NO(x) emissions in lean premixed gas turbine combustors

NASA Technical Reports Server (NTRS)

Shih, W.-P.; Lee, J. G.; Santavicca, D. A.

1994-01-01

Gas turbine engines for both land-based and aircraft propulsion applications are facing regulations on NOx emissions which cannot be met with current combustor technology. A number of alternative combustor strategies are being investigated which have the potential capability of achieving ultra-low NOx emissions, including lean premixed combustors, direct injection combustors, rich burn-quick quench-lean burn combustors and catalytic combustors. The research reported in this paper addresses the effect of incomplete fuel-air mixing on the lean limit performance and the NOx emissions characteristics of lean premixed combustors.

Innovative Adaptive Control Method Demonstrated for Active Suppression of Instabilities in Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George

2005-01-01

This year, an improved adaptive-feedback control method was demonstrated that suppresses thermoacoustic instabilities in a liquid-fueled combustor of a type used in aircraft engines. Extensive research has been done to develop lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle to reduce the environmental impact of aerospace propulsion systems. However, these lean-burning combustors are susceptible to thermoacoustic instabilities (high-frequency pressure waves), which can fatigue combustor components and even downstream turbine blades. This can significantly decrease the safe operating life of the combustor and turbine. Thus, suppressing the thermoacoustic combustor instabilities is an enabling technology for meeting the low-emission goals of the NASA Ultra-Efficient Engine Technology (UEET) Project.

Criteria pollutant and greenhouse gas emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies.

PubMed

Yoon, Seungju; Collins, John; Thiruvengadam, Arvind; Gautam, Mridul; Herner, Jorn; Ayala, Alberto

2013-08-01

Engine and exhaust control technologies applied to compressed natural gas (CNG) transit buses have advanced from lean-burn, to lean-burn with oxidation catalyst (OxC), to stoichiometric combustion with three-way catalyst (TWC). With this technology advancement, regulated gaseous and particulate matter emissions have been significantly reduced. Two CNG transit buses equipped with stoichiometric combustion engines and TWCs were tested on a chassis dynamometer, and their emissions were measured. Emissions from the stoichiometric engines with TWCs were then compared to the emissions from lean-burn CNG transit buses tested in previous studies. Stoichiometric combustion with TWC was effective in reducing emissions of oxides of nitrogen (NO(x)), particulate matter (PM), and nonmethane hydrocarbon (NMHC) by 87% to 98% depending on pollutants and test cycles, compared to lean combustion. The high removal efficiencies exceeded the emission reduction required from the certification standards, especially for NO(x) and PM. While the certification standards require 95% and 90% reductions for NO(x) and PM, respectively, from the engine model years 1998-2003 to the engine model year 2007, the measured NO(x) and PM emissions show 96% and 95% reductions, respectively, from the lean-burn engines to the stoichiometric engines with TWC over the transient Urban Dynamometer Driving Schedule (UDDS) cycle. One drawback of stoichiometric combustion with TWC is that this technology produces higher carbon monoxide (CO) emissions than lean combustion. In regard to controlling CO emissions, lean combustion with OxC is more effective than stoichiometric combustion. Stoichiometric combustion with TWC produced higher greenhouse gas (GHG) emissions including carbon dioxide (CO2) and methane (CH4) than lean combustion during the UDDS cycle, but lower GHG emissions during the steady-state cruise cycle. Stoichiometric combustion with three-way catalyst is currently the best emission control technology available for compressed natural gas (CNG) transit buses to meet the stringent U.S. Environmental Protection Agency (EPA) 2010 heavy-duty engine NO(x) emissions standard. For existing lean-burn CNG transit buses in the fleet, oxidation catalyst would be the most effective retrofit technology for the control of NMHC and CO emissions.

Effects of spark plug configuration on combustion and emission characteristics of a LPG fuelled lean burn SI engine

NASA Astrophysics Data System (ADS)

Ravi, K.; Khan, Manazir Ahmed; Pradeep Bhasker, J.; Porpatham, E.

2017-11-01

Introduction of technological innovation in automotive engines in reducing pollution and increasing efficiency have been under contemplation. Gaseous fuels have proved to be a promising way to reduce emissions in Spark Ignition (SI) engines. In particular, LPG settled to be a favourable fuel for SI engines because of their higher hydrogen to carbon ratio, octane rating and lower emissions. Wide ignition limits and efficient combustion characteristics make LPG suitable for lean burn operation. But lean combustion technology has certain drawbacks like poor flame propagation, cyclic variations etc. Based on copious research it was found that location, types and number of spark plug significantly influence in reducing cyclic variations. In this work the influence of single and dual spark plugs of conventional and surface discharge electrode type were analysed. Dual surface discharge electrode spark plug enhanced the brake thermal efficiency and greatly reduced the cyclic variations. The experimental results show that rate of heat release and pressure rise was more and combustion duration was shortened in this configuration. On the emissions front, the NOx emission has increased whereas HC and CO emissions were reduced under lean condition.

40 CFR 63.6590 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Existing spark ignition 2 stroke lean burn (2SLB) stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions; (ii) Existing spark ignition 4 stroke lean burn (4SLB... emissions; (4) A new or reconstructed spark ignition 4 stroke rich burn (4SRB) stationary RICE with a site...

40 CFR 63.6590 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Existing spark ignition 2 stroke lean burn (2SLB) stationary RICE with a site rating of more than 500 brake HP located at a major source of HAP emissions; (ii) Existing spark ignition 4 stroke lean burn (4SLB... emissions; (4) A new or reconstructed spark ignition 4 stroke rich burn (4SRB) stationary RICE with a site...

40 CFR 63.6590 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2012 CFR

2012-07-01

... initial notification requirements: (i) Existing spark ignition 2 stroke lean burn (2SLB) stationary RICE... spark ignition 4 stroke lean burn (4SLB) stationary RICE with a site rating of more than 500 brake HP... spark ignition 4 stroke rich burn (4SRB) stationary RICE with a site rating of less than or equal to 500...

Prechamber equipped laser ignition for improved performance in natural gas engines

DOE PAGES

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.; ...

2017-04-25

Lean-burn operation of stationary natural gas engines offers lower NO x emissions and improved efficiency. A proven pathway to extend lean-burn operation has been to use laser ignition instead of standard spark ignition. However, under lean conditions, flame speed reduces thereby offsetting any efficiency gains resulting from the higher ratio of specific heats, γ. The reduced flame speeds, in turn, can be compensated with the use of a prechamber to result in volumetric ignition, and thereby lead to faster combustion. In this study, the optimal geometry of PCLI was identified through several tests in a single-cylinder engine as a compromisemore » between autoignition, NO x and soot formation within the prechamber. Subsequently, tests were conducted in a single-cylinder natural gas engine comparing the performance of three ignition systems: standard electrical spark ignition (SI), single-point laser ignition (LI), and prechamber equipped laser ignition (PCLI). Out of the three, the performance of PCLI was far superior compared to the other two. Efficiency gain of 2.1% points could be achieved while complying with EPA regulation (BSNO x < 1.34 kW-hr) and the industry standard for ignition stability (COV_IMEP < 5%). Finally, test results and data analysis are presented identifying the combustion mechanisms leading to the improved performance.« less

77 FR 25785 - Proposed Information Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

... for Office of Management and Budget (OMB) approval of the relevant information collection. All...: Credit for New Qualified Alternative Motor Vehicles (Advanced Lean Burn Technology Motor Vehicles and...) certification that both a particular make, model and year of vehicle qualifies as an advanced lean burn...

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.

Combustor technology for future small gas turbine aircraft

NASA Technical Reports Server (NTRS)

Lyons, Valerie J.; Niedzwiecki, Richard W.

1993-01-01

Future engine cycles proposed for advanced small gas turbine engines will increase the severity of the operating conditions of the combustor. These cycles call for increased overall engine pressure ratios which increase combustor inlet pressure and temperature. Further, the temperature rise through the combustor and the corresponding exit temperature also increase. Future combustor technology needs for small gas turbine engines is described. New fuel injectors with large turndown ratios which produce uniform circumferential and radial temperature patterns will be required. Uniform burning will be of greater importance because hot gas temperatures will approach turbine material limits. The higher combustion temperatures and increased radiation at high pressures will put a greater heat load on the combustor liners. At the same time, less cooling air will be available as more of the air will be used for combustion. Thus, improved cooling concepts and/or materials requiring little or no direct cooling will be required. Although presently there are no requirements for emissions levels from small gas turbine engines, regulation is expected in the near future. This will require the development of low emission combustors. In particular, nitrogen oxides will increase substantially if new technologies limiting their formation are not evolved and implemented. For example, staged combustion employing lean, premixed/prevaporized, lean direct injection, or rich burn-quick quench-lean burn concepts could replace conventional single stage combustors.

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.

Effect of Maximum Cruise-power Operation at Ultra-lean Mixture and Increased Spark Advance on the Mechanical Condition of Cylinder Components

NASA Technical Reports Server (NTRS)

Harris, Herbert B.; Duffy, Robert T.; Erwin, Robert D., Jr.

1945-01-01

A continuous 50-hour test was conducted to determine the effect of maximum cruise-power operation at ultra-lean fuel-air mixture and increased spark advance on the mechanical conditions of cylinder components. The test was conducted on a nine-cylinder air-cooled radial engine at the following conditions:brake horsepower, 750; engine speed, 1900 rpm; brake mean effective pressure, 172 pounds per square inch; fuel-air ratio, 0.052; spark advance, 30 deg B.T.C.; and maximum rear-spark-plug-bushing temperature, 400 F. In addition to the data on corrosion and wear, data are presented and briefly discussed on the effect of engine operation at the conditions of this test on economy, knock, preignition, and mixture distribution. Cylinder, piston, and piston-ring wear was small and all cylinder component were in good condition at the conclusion of the 50-hour test except that all exhaust-valve guides were bellmouthed beyond the Army's specified limit and one exhaust-valve face was lightly burned. It is improbable that the light burning in one spot of the valve face would have progressed further because the burn was filled with a hard deposit so that the valve face formed an unbroken seal and the mating seat showed no evidence of burning. The bellmouthing of the exhaust-valve guides is believed to have been a result of the heavy carbon and lead-oxide deposits, which were present on the head end of the guided length of the exhaust-valve stem. Engine operational the conditions of this test was shown to result In a fuel saving of 16.8 percent on a cooled-power basis as compared with operation at the conditions recommended for this engine by the Army Air Forces for the same power.

Ammonia Generation and Utilization in a Passive SCR (TWC+SCR) System on Lean Gasoline Engine

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

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

Lean gasoline engines offer greater fuel economy than the common stoichiometric gasoline engine, but the current three way catalyst (TWC) on stoichiometric engines is unable to control nitrogen oxide (NOX) emissions in oxidizing exhaust. For these lean gasoline engines, lean NOX emission control is required to meet existing Tier 2 and upcoming Tier 3 emission regulations set by the U.S. Environmental Protection Agency (EPA). While urea-based selective catalytic reduction (SCR) has proven effective in controlling NOX from diesel engines, the urea storage and delivery components can add significant size and cost. As such, onboard NH 3 production via a passivemore » SCR approach is of interest. In a passive SCR system, NH 3 is generated over a close-coupled TWC during periodic slightly rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean operation, NOX passes through the TWC and is reduced by the stored NH 3 on the SCR catalyst. In this work, a passive SCR system was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine to assess NH 3 generation over a Pd-only TWC and utilization over a Cu-based SCR catalyst. System NOX reduction efficiency and fuel efficiency improvement compared to stoichiometric engine operation were measured. A feedback control strategy based on cumulative NH 3 produced by the TWC during rich operation and NOX emissions during lean operation was implemented on the engine to control lean/rich cycle timing. At an SCR average inlet temperature of 350 °C, an NH 3:NOX ratio of 1.15:1 (achieved through longer rich cycle timing) resulted in 99.7 % NOX conversion. Increasing NH 3 generation further resulted in even higher NOX conversion; however, tailpipe NH 3 emissions resulted. At higher underfloor temperatures, NH 3 oxidation over the SCR limited NH 3 availability for NOX reduction. At the engine conditions studied, greater than 99 % NOX conversion was achieved with passive SCR while delivering fuel efficiency benefits ranging between 6-11 % compared with stoichiometric operation.« less

Ammonia Generation and Utilization in a Passive SCR (TWC+SCR) System on Lean Gasoline Engine

DOE PAGES

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

2016-04-05

Lean gasoline engines offer greater fuel economy than the common stoichiometric gasoline engine, but the current three way catalyst (TWC) on stoichiometric engines is unable to control nitrogen oxide (NOX) emissions in oxidizing exhaust. For these lean gasoline engines, lean NOX emission control is required to meet existing Tier 2 and upcoming Tier 3 emission regulations set by the U.S. Environmental Protection Agency (EPA). While urea-based selective catalytic reduction (SCR) has proven effective in controlling NOX from diesel engines, the urea storage and delivery components can add significant size and cost. As such, onboard NH 3 production via a passivemore » SCR approach is of interest. In a passive SCR system, NH 3 is generated over a close-coupled TWC during periodic slightly rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean operation, NOX passes through the TWC and is reduced by the stored NH 3 on the SCR catalyst. In this work, a passive SCR system was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine to assess NH 3 generation over a Pd-only TWC and utilization over a Cu-based SCR catalyst. System NOX reduction efficiency and fuel efficiency improvement compared to stoichiometric engine operation were measured. A feedback control strategy based on cumulative NH 3 produced by the TWC during rich operation and NOX emissions during lean operation was implemented on the engine to control lean/rich cycle timing. At an SCR average inlet temperature of 350 °C, an NH 3:NOX ratio of 1.15:1 (achieved through longer rich cycle timing) resulted in 99.7 % NOX conversion. Increasing NH 3 generation further resulted in even higher NOX conversion; however, tailpipe NH 3 emissions resulted. At higher underfloor temperatures, NH 3 oxidation over the SCR limited NH 3 availability for NOX reduction. At the engine conditions studied, greater than 99 % NOX conversion was achieved with passive SCR while delivering fuel efficiency benefits ranging between 6-11 % compared with stoichiometric operation.« less

Combustion characteristics of hydrogen. Carbon monoxide based gaseous fuels

NASA Technical Reports Server (NTRS)

Notardonato, J. J.; White, D. J.; Kubasco, A. J.; Lecren, R. T.

1981-01-01

An experimental rig program was conducted with the objective of evaluating the combuston performance of a family of fuel gases based on a mixture of hydrogen and carbon monoxide. These gases, in addition to being members of a family, were also representative of those secondary fuels that could be produced from coal by various gasification schemes. In particular, simulated Winkler, Lurgi, and Blue-water low and medium energy content gases were used as fuels in the experimental combustor rig. The combustor used was originally designed as a low NOx rich-lean system for burning liquid fuels with high bound nitrogen levels. When used with the above gaseous fuels this combustor was operated in a lean-lean mode with ultra long residence times. The Blue-water gas was also operated in a rich-lean mode. The results of these tests indicate the possibility of the existence of an 'optimum' gas turbine hydrogen - carbon monoxide based secondary fuel. Such a fuel would exhibit NOx and high efficiency over the entire engine operating range. It would also have sufficient stability range to allow normal light-off and engine acceleration. Solar Turbines Incorporated would like to emphasize that the results presented here have been obtained with experimental rig combustors. The technologies generated could, however, be utilized in future commercial gas turbines.

Cyclic variations of fuel-droplet distribution during the early intake stroke of a lean-burn stratified-charge spark-ignition engine

NASA Astrophysics Data System (ADS)

Aleiferis, P. G.; Hardalupas, Y.; Taylor, A. M. K. P.; Ishii, K.; Urata, Y.

2005-11-01

Lean-burn spark-ignition engines exhibit higher efficiency and lower specific emissions in comparison with stoichiometrically charged engines. However, as the air-to-fuel (A/F) ratio of the mixture is made leaner than stoichiometric, cycle-by-cycle variations in the early stages of in-cylinder combustion, and subsequent indicated mean effective pressure (IMEP), become more pronounced and limit the range of lean-burn operation. Viable lean-burn engines promote charge stratification, the mixture near the spark plug being richer than the cylinder volume averaged value. Recent work has shown that cycle-by-cycle variations in the early stages of combustion in a stratified-charge engine can be associated with variations in both the local value of A/F ratio near the spark plug around ignition timing, as well as in the volume averaged value of the A/F ratio. The objective of the current work was to identify possible sources of such variability in A/F ratio by studying the in-cylinder field of fuel-droplet distribution during the early intake stroke. This field was visualised in an optical single-cylinder 4-valve pentroof-type spark-ignition engine by means of laser-sheet illumination in planes parallel to the cylinder head gasket 6 and 10 mm below the spark plug. The engine was run with port-injected isooctane at 1500 rpm with 30% volumetric efficiency and air-to-fuel ratio corresponding to both stoichiometric firing (A/F=15, Φ =1.0) and mixture strength close to the lean limit of stable operation (A/F=22, Φ =0.68). Images of Mie intensity scattered by the cloud of fuel droplets were acquired on a cycle-by-cycle basis. These were studied in order to establish possible correlations between the cyclic variations in size, location and scattered-light intensity of the cloud of droplets with the respective variations in IMEP. Because of the low level of Mie intensity scattered by the droplets and because of problems related to elastic scattering on the walls of the combustion chamber, as well as problems related to engine “rocking” at the operating conditions close to the misfire limit, the acquired images were processed for background subtraction by using a PIV-based data correction algorithm. After this processing, the arrival and leaving timings of fuel droplets into the illuminated plane were found not to vary significantly on a cycle-by-cycle basis but the recorded cycle-by-cycle variations in Mie intensity suggested that the amount of fuel in the cylinder could have been 6 26% greater for the “strong” cycles with IMEP 115% higher than the average IMEP, than the ones imaged for “weak” cycles at less than 85% the average IMEP. This would correspond to a maximum cyclic variability in the in-cylinder equivalence ratio Φ of the order of 0.17.

Turbulent Burning Velocities of Two-Component Fuel Mixtures of Methane, Propane and Hydrogen

NASA Astrophysics Data System (ADS)

Kido, Hiroyuki; Nakahara, Masaya; Hashimoto, Jun; Barat, Dilmurat

In order to clarify the turbulent burning velocity of multi-component fuel mixtures, both lean and rich two-component fuel mixtures, in which methane, propane and hydrogen were used as fuels, were prepared while maintaining the laminar burning velocity approximately constant. A distinct difference in the measured turbulent burning velocity at the same turbulence intensity is observed for two-component fuel mixtures having different addition rates of fuel, even the laminar burning velocities are approximately the same. The burning velocities of lean mixtures change almost constantly as the rate of addition changes, whereas the burning velocities of the rich mixtures show no such tendency. This trend can be explained qualitatively based on the mean local burning velocity, which is estimated by taking into account the preferential diffusion effect for each fuel component. In addition, a model of turbulent burning velocity proposed for single-component fuel mixtures may be applied to two-component fuel mixtures by considering the estimated mean local burning velocity of each fuel.

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

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

Nigel N. Clark

Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, amore » percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions, with added EGR to prevent preignition. It was observed that the relative air/fuel ratio, injected NO quantity, added EGR fraction, and engine operating points affected the NO decomposition rates. While operating under these modified conditions, the highest NO decomposition rate of 92% was observed. In-cylinder pressure data gathered during the experiments showed minimum deviation from peak pressure as a result of NO injections into the engine. A NOx adsorption system, from Sorbent Technologies, Inc., was integrated with the Cummins engine, comprised a NOx adsorbent chamber, heat exchanger, demister, and a hot air blower. Data were gathered to show the possibility of NOx adsorption from the engine exhaust, and desorption of NOx from the sorbent material. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a benchtop adsorption system was constructed. The temperature of this apparatus was controlled while data were gathered on the characteristics of the sorbent material for development of a system model. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passed over fresh sorbent material. A mass heat transfer analysis was conducted to analyze the possibility of using hot exhaust gas for the desorption process. It was found in the adsorption studies, and through literature review, that NO adsorption was poor when the carrier gas was nitrogen, but that NO in the presence of oxygen was adsorbed at levels exceeding 1% by mass of the sorbent. From the three experimental campaigns, chemical kinetic modeling analysis, and the scaled benchtop NOx adsorption system, an overall SNR system model was developed. An economic analysis was completed, and showed that the system was impractical in cost for small engines, but that economies of scale favored the technology.« less

Ammonia Generation and Utilization in a Passive SCR (TWC+SCR) System on Lean Gasoline Engine

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

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

Lean gasoline engines offer greater fuel economy than the common stoichiometric gasoline engine, but the current three-way catalyst (TWC) on stoichiometric engines is unable to control nitrogen oxide (NOX) emissions in the oxygen-rich exhaust. Thus, lean NOX emission control is required to meet existing Tier 2 and upcoming Tier 3 emission regulations set by the U.S. Environmental Protection Agency (EPA). While urea-based selective catalytic reduction (SCR) has proven effective in controlling NOX from diesel engines, the urea storage and delivery components can add significant size and cost. As such, onboard NH3 production via a passive SCR approach is of interest.more » In a passive SCR system, NH3 is generated over a close-coupled TWC during periodic slightly rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean operation, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst. In this work, a passive SCR system was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine to assess NH3 generation over a Pd-only TWC and utilization over a Cu-based SCR catalyst. System NOX reduction efficiency and fuel efficiency improvement compared to stoichiometric engine operation were measured. A feedback control strategy based on cumulative NH3 produced by the TWC during rich operation and NOX emissions during lean operation was implemented on the engine to control lean/rich cycle timing. 15% excess NH3 production over a 1:1 NH3:NOX ratio was required (via longer rich cycle timing) to achieve 99.7% NOX conversion at an SCR average inlet temperature of 350 C. Increasing NH3 generation further resulted in even higher NOX conversion; however, tailpipe NH3 emissions resulted. At higher temperatures, NH3 oxidation becomes important and limits NH3 availability for NOX reduction. At the engine conditions studied here, greater than 99% NOX conversion was achieved with passive SCR while delivering fuel efficiency benefits ranging between 6-11% compared with stoichiometric operation.« less

Two-Dimensional Imaging of OH in a Lean Burning High Pressure Combustor

NASA Technical Reports Server (NTRS)

Locke, R. J.; Hicks, Y. R.; Anderson, R. C.; Ockunzzi, K. A.; North, G. L.

1995-01-01

Planar laser-induced fluorescence (PLIF) images of OH have been obtained from an optically accessible, lean burning high pressure combustor burning Jet-A fuel. These images were obtained using various laser excitation lines of the OH A (reverse arrow) X (1,0) band for several fuel injector configurations with pressures ranging from 1013 kPa (10 atm) to 1419 kPa (14 atm). Non-uniformities in the combusting flow, attributed to differences in fuel injector configuration, are revealed by these images. Contributions attributable to fluorescent aromatic hydrocarbons and complex fuel chemistries are also not evident.

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.

Exhaust particle characterization for lean and stoichiometric DI vehicles operating on ethanol-gasoline blends

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

Storey, John Morse; Barone, Teresa L; Thomas, John F

2012-01-01

Gasoline direct injection (GDI) engines can offer better fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet the U.S. fuel economy standards for 2016. Furthermore, lean-burn GDI engines can offer even higher fuel economy than stoichiometric GDI engines and have overcome challenges associated with cost-effective aftertreatment for NOx control. Along with changes in gasoline engine technology, fuel composition may increase in ethanol contentmore » beyond the current 10% due to the recent EPA waiver allowing 15% ethanol. In addition, the Renewable Fuels Standard passed as part of the 2007 Energy Independence and Security Act (EISA) mandates the use of biofuels in upcoming years. GDI engines are of environmental concern due to their high particulate matter (PM) emissions relative to port-fuel injected (PFI) gasoline vehicles; widespread market penetration of GDI vehicles may result in additional PM from mobile sources at a time when the diesel contribution is declining. In this study, we characterized particulate emissions from a European certified lean-burn GDI vehicle operating on ethanol-gasoline blends. Particle mass and particle number concentration emissions were measured for the Federal Test Procedure urban driving cycle (FTP 75) and the more aggressive US06 driving cycle. Particle number-size distributions and organic to elemental carbon ratios (OC/EC) were measured for 30 MPH and 80 MPH steady-state operation. In addition, particle number concentration was measured during wide open throttle accelerations (WOTs) and gradual accelerations representative of the FTP 75. Fuels included certification gasoline and 10% (E10) and 20% (E20) ethanol blends from the same supplier. The particle mass emissions were approximately 3 and 7 mg/mile for the FTP75 and US06, respectively, with lower emissions for the ethanol blends. The data are compared to a previous study on a U.S.-legal stoichiometric GDI vehicle operating on the same ethanol blends. The lean-burn GDI vehicle emitted a higher number of particles, but had an overall smaller average size. Particle number per mile decreased with increasing ethanol content for the transient tests. For the 30 and 80 mph tests, particle number concentration decreased with increasing ethanol content, although the shape of the particle size distribution remained the same. Engine-out OC/EC ratios were highest for the stoichiometric GDI vehicle with E20, but tailpipe OC/EC ratios were similar for all vehicles.« less

Low NO sub x heavy fuel combustor concept program

NASA Technical Reports Server (NTRS)

Russell, P.; Beal, G.; Hinton, B.

1981-01-01

A gas turbine technology program to improve and optimize the staged rich lean low NOx combustor concept is described. Subscale combustor tests to develop the design information for optimization of the fuel preparation, rich burn, quick air quench, and lean burn steps of the combustion process were run. The program provides information for the design of high pressure full scale gas turbine combustors capable of providing environmentally clean combustion of minimally of minimally processed and synthetic fuels. It is concluded that liquid fuel atomization and mixing, rich zone stoichiometry, rich zone liner cooling, rich zone residence time, and quench zone stoichiometry are important considerations in the design and scale up of the rich lean combustor.

Simulation of mixing in the quick quench region of a rich burn-quick quench mix-lean burn combustor

NASA Technical Reports Server (NTRS)

Shih, Tom I.-P.; Nguyen, H. Lee; Howe, Gregory W.; Li, Z.

1991-01-01

A computer program was developed to study the mixing process in the quick quench region of a rich burn-quick quench mix-lean burn combustor. The computer program developed was based on the density-weighted, ensemble-averaged conservation equations of mass, momentum (full compressible Navier-Stokes), total energy, and species, closed by a k-epsilon turbulence model with wall functions. The combustion process was modeled by a two-step global reaction mechanism, and NO(x) formation was modeled by the Zeldovich mechanism. The formulation employed in the computer program and the essence of the numerical method of solution are described. Some results obtained for nonreacting and reacting flows with different main-flow to dilution-jet momentum flux ratios are also presented.

Adaptive Controls Method Demonstrated for the Active Suppression of Instabilities in Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George

2004-01-01

An adaptive feedback control method was demonstrated that suppresses thermoacoustic instabilities in a liquid-fueled combustor of a type used in aircraft engines. Extensive research has been done to develop lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle to reduce the environmental impact of aerospace propulsion systems. However, these lean-burning combustors are susceptible to thermoacoustic instabilities (high-frequency pressure waves), which can fatigue combustor components and even the downstream turbine blades. This can significantly decrease the safe operating lives of the combustor and turbine. Thus, suppressing the thermoacoustic combustor instabilities is an enabling technology for lean, low-emissions combustors under NASA's Propulsion and Power Program. This control methodology has been developed and tested in a partnership of the NASA Glenn Research Center, Pratt & Whitney, United Technologies Research Center, and the Georgia Institute of Technology. Initial combustor rig testing of the controls algorithm was completed during 2002. Subsequently, the test results were analyzed and improvements to the method were incorporated in 2003, which culminated in the final status of this controls algorithm. This control methodology is based on adaptive phase shifting. The combustor pressure oscillations are sensed and phase shifted, and a high-frequency fuel valve is actuated to put pressure oscillations into the combustor to cancel pressure oscillations produced by the instability.

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

Combustor materials requirements and status of ceramic matrix composites

NASA Technical Reports Server (NTRS)

Hecht, Ralph J.; Johnson, Andrew M.

1992-01-01

The HSCT combustor will be required to operate with either extremely rich or lean fuel/air ratios to reduce NO(x) emission. NASA High Speed Research (HSR) sponsored programs at Pratt & Whitney (P&W) and GE Aircraft Engines (GEAE) have been studying rich and lean burn combustor design approaches which are capable of achieving the aggressive HSCT NO(x) emission goals. In both of the combustor design approaches under study, high temperature (2400-3000 F) materials are necessary to meet the HSCT emission goals of 3-8 gm/kg. Currently available materials will not meet the projected requirements for the HSCT combustor. The development of new materials is an enabling technology for the successful introduction to service of the HSCT.

Performance of a Laser Ignited Multicylinder Lean Burn Natural Gas Engine

DOE PAGES

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.; ...

2017-06-06

Market demands for lower fueling costs and higher specific powers in stationary natural gas engines has engine designs trending towards higher in-cylinder pressures and leaner combustion operation. However, Ignition remains as the main limiting factor in achieving further performance improvements in these engines. Addressing this concern, while incorporating various recent advances in optics and laser technologies, laser igniters were designed and developed through numerous iterations. Final designs incorporated water-cooled, passively Q-switched, Nd:YAG micro-lasers that were optimized for stable operation under harsh engine conditions. Subsequently, the micro-lasers were installed in the individual cylinders of a lean-burn, 350 kW, inline 6-cylinder, open-chamber,more » spark ignited engine and tests were conducted. To the best of our knowledge, this is the world’s first demonstration of a laser ignited multi-cylinder natural gas engine. The engine was operated at high-load (298 kW) and rated speed (1800 rpm) conditions. Ignition timing sweeps and excess-air ratio (λ) sweeps were performed while keeping the NOx emissions below the USEPA regulated value (BSNOx < 1.34 g/kW-hr), and while maintaining ignition stability at industry acceptable values (COV_IMEP <5 %). Through such engine tests, the relative merits of (i) standard electrical ignition system, and (ii) laser ignition system were determined. In conclusion, a rigorous combustion data analysis was performed and the main reasons leading to improved performance in the case of laser ignition were identified.« less

Performance of a Laser Ignited Multicylinder Lean Burn Natural Gas Engine

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

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.

Market demands for lower fueling costs and higher specific powers in stationary natural gas engines has engine designs trending towards higher in-cylinder pressures and leaner combustion operation. However, Ignition remains as the main limiting factor in achieving further performance improvements in these engines. Addressing this concern, while incorporating various recent advances in optics and laser technologies, laser igniters were designed and developed through numerous iterations. Final designs incorporated water-cooled, passively Q-switched, Nd:YAG micro-lasers that were optimized for stable operation under harsh engine conditions. Subsequently, the micro-lasers were installed in the individual cylinders of a lean-burn, 350 kW, inline 6-cylinder, open-chamber,more » spark ignited engine and tests were conducted. To the best of our knowledge, this is the world’s first demonstration of a laser ignited multi-cylinder natural gas engine. The engine was operated at high-load (298 kW) and rated speed (1800 rpm) conditions. Ignition timing sweeps and excess-air ratio (λ) sweeps were performed while keeping the NOx emissions below the USEPA regulated value (BSNOx < 1.34 g/kW-hr), and while maintaining ignition stability at industry acceptable values (COV_IMEP <5 %). Through such engine tests, the relative merits of (i) standard electrical ignition system, and (ii) laser ignition system were determined. In conclusion, a rigorous combustion data analysis was performed and the main reasons leading to improved performance in the case of laser ignition were identified.« less

Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

PubMed

Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

2012-02-21

The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

Numerical Study of Low Emission Gas Turbine Combustor Concepts

NASA Technical Reports Server (NTRS)

Yang, Song-Lin

2002-01-01

To further reduce pollutant emissions, such as CO, NO(x), UHCs, etc., in the next few decades, innovative concepts of gas turbine combustors must be developed. Several concepts, such as the LIPP (Lean- Premixed- Prevaporized), RQL (Rich-Burn Quick-Quench Lean-Burn), and LDI (Lean-Direct-Injection), have been under study for many years. To fully realize the potential of these concepts, several improvements, such as inlet geometry, air swirler, aerothermochemistry control, fuel preparation, fuel injection and injector design, etc., must be made, which can be studied through the experimental method and/or the numerical technique. The purpose of this proposal is to use the CFD technique to study, and hence, to guide the design process for low emission gas turbine combustors. A total of 13 technical papers have been (or will be) published.

Two-stage combustion for reducing pollutant emissions from gas turbine combustors

NASA Technical Reports Server (NTRS)

Clayton, R. M.; Lewis, D. H.

1981-01-01

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

Lean, premixed, prevaporized fuel combustor conceptual design study

NASA Technical Reports Server (NTRS)

Fiorentino, A. J.; Greene, W.; Kim, J.

1979-01-01

Four combustor concepts, designed for the energy efficient engine, utilize variable geometry or other flow modulation techniques to control the equivalence ratio of the initial burning zone. Lean conditions are maintained at high power to control oxides of nitrogen while near stoichometric conditions are maintained at low power for low CO and THC emissions. Each concept was analyzed and ranked for its potential in meeting the goals of the program. Although the primary goal of the program is a low level of nitric oxide emissions at stratospheric cruise conditions, both the ground level EPA emission standards and combustor performance and operational requirements typical of advanced subsonic aircraft engines are retained as goals as well. Based on the analytical projections made, two of the concepts offer the potential of achieving the emission goals; however, the projected operational characteristics and reliability of any concept to perform satisfactorily over an entire aircraft flight envelope would require extensive experimental substantiation before engine adaptation can be considered.

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

Sevik, James; Wallner, Thomas; Pamminger, Michael

The efficiency improvement and emissions reduction potential of lean and exhaust gas recirculation (EGR)-dilute operation of spark-ignition gasoline engines is well understood and documented. However, dilute operation is generally limited by deteriorating combustion stability with increasing inert gas levels. The combustion stability decreases due to reduced mixture flame speeds resulting in significantly increased combustion initiation periods and burn durations. A study was designed and executed to evaluate the potential to extend lean and EGR-dilute limits using a low-energy transient plasma ignition system. The low-energy transient plasma was generated by nanosecond pulses and its performance compared to a conventional transistorized coilmore » ignition (TCI) system operated on an automotive, gasoline direct-injection (GDI) single-cylinder research engine. The experimental assessment was focused on steady-state experiments at the part load condition of 1500 rpm 5.6 bar indicated mean effective pressure (IMEP), where dilution tolerance is particularly critical to improving efficiency and emission performance. Experimental results suggest that the energy delivery process of the low-energy transient plasma ignition system significantly improves part load dilution tolerance by reducing the early flame development period. Statistical analysis of relevant combustion metrics was performed in order to further investigate the effects of the advanced ignition system on combustion stability. Results confirm that at select operating conditions EGR tolerance and lean limit could be improved by as much as 20% (from 22.7 to 27.1% EGR) and nearly 10% (from λ = 1.55 to 1.7) with the low-energy transient plasma ignition system.« less

Catalysts, systems and methods to reduce NOX in an exhaust gas stream

DOEpatents

Castellano, Christopher R.; Moini, Ahmad; Koermer, Gerald S.; Furbeck, Howard

2010-07-20

Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having an SCR catalyst comprising silver tungstate on an alumina support. The emissions treatment system may be used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines. An emissions treatment system may further comprise an injection device operative to dispense a hydrocarbon reducing agent upstream of the catalyst.

First-principles-based kinetic Monte Carlo simulation of nitric oxide decomposition over Pt and Rh surfaces under lean-burn conditions

NASA Astrophysics Data System (ADS)

Mei, Donghai; Ge, Qingfeng; Neurock, Matthew; Kieken, Laurent; Lerou, Jan

First-principles-based kinetic Monte Carlo simulation was used to track the elementary surface transformations involved in the catalytic decomposition of NO over Pt(100) and Rh(100) surfaces under lean-burn operating conditions. Density functional theory (DFT) calculations were carried out to establish the structure and energetics for all reactants, intermediates and products over Pt(100) and Rh(100). Lateral interactions which arise from neighbouring adsorbates were calculated by examining changes in the binding energies as a function of coverage and different coadsorbed configurations. These data were fitted to a bond order conservation (BOC) model which is subsequently used to establish the effects of coverage within the simulation. The intrinsic activation barriers for all the elementary reaction steps in the proposed mechanism of NO reduction over Pt(100) were calculated by using DFT. These values are corrected for coverage effects by using the parametrized BOC model internally within the simulation. This enables a site-explicit kinetic Monte Carlo simulation that can follow the kinetics of NO decomposition over Pt(100) and Rh(100) in the presence of excess oxygen. The simulations are used here to model various experimental protocols including temperature programmed desorption as well as batch catalytic kinetics. The simulation results for the temperature programmed desorption and decomposition of NO over Pt(100) and Rh(100) under vacuum condition were found to be in very good agreement with experimental results. NO decomposition is strongly tied to the temporal number of sites that remain vacant. Experimental results show that Pt is active in the catalytic reaction of NO into N2 and NO2 under lean-burn conditions. The simulated reaction orders for NO and O2 were found to be +0.9 and -0.4 at 723 K, respectively. The simulation also indicates that there is no activity over Rh(100) since the surface becomes poisoned by oxygen.

Body Composition Changes in Severely Burned Children During ICU Hospitalization.

PubMed

Cambiaso-Daniel, Janos; Malagaris, Ioannis; Rivas, Eric; Hundeshagen, Gabriel; Voigt, Charles D; Blears, Elizabeth; Mlcak, Ron P; Herndon, David N; Finnerty, Celeste C; Suman, Oscar E

2017-12-01

Prolonged hospitalization due to burn injury results in physical inactivity and muscle weakness. However, how these changes are distributed among body parts is unknown. The aim of this study was to evaluate the degree of body composition changes in different anatomical regions during ICU hospitalization. Retrospective chart review. Children's burn hospital. Twenty-four severely burned children admitted to our institution between 2000 and 2015. All patients underwent a dual-energy x-ray absorptiometry within 2 weeks after injury and 2 weeks before discharge to determine body composition changes. No subject underwent anabolic intervention. We analyzed changes of bone mineral content, bone mineral density, total fat mass, total mass, and total lean mass of the entire body and specifically analyzed the changes between the upper and lower limbs. In the 24 patients, age was 10 ± 5 years, total body surface area burned was 59% ± 17%, time between dual-energy x-ray absorptiometries was 34 ± 21 days, and length of stay was 39 ± 24 days. We found a significant (p < 0.001) average loss of 3% of lean mass in the whole body; this loss was significantly greater (p < 0.001) in the upper extremities (17%) than in the lower extremities (7%). We also observed a remodeling of the fat compartments, with a significant whole-body increase in fat mass (p < 0.001) that was greater in the truncal region (p < 0.0001) and in the lower limbs (p < 0.05). ICU hospitalization is associated with greater lean mass loss in the upper limbs of burned children. Mobilization programs should include early mobilization of upper limbs to restore upper extremity function.

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.

Mixing of Pure Air Jets with a Reacting Fuel-Rich Crossflow

NASA Technical Reports Server (NTRS)

Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

1997-01-01

Jets in a crossflow play an integral role in practical combustion systems such as can and annular gas turbine combustors in conventional systems, and the Rich-burn/Quick-mix/Lean-burn (RQL) combustor utilized in stationary applications and proposed for advanced subsonic and supersonic transports. The success of the RQL combustor rests with the performance of the quick-mixing section that bridges the rich and lean zones. The mixing of jet air with a rich crossflow to bring the reaction to completion in the lean zone must be performed rapidly and thoroughly in order to decrease the extent of near-stoichiometric fluid pocket formation. Fluid pockets at near-stoichiometric equivalence ratios are undesirable because the high temperatures attained accelerate pollutant formation kinetics associated with nitric oxide (NO). The present study develops a model experiment designed to reveal the processes that occur when jet air is introduced into hot effluent emanating from a fuel-rich reaction zone.

Pollutant Emissions and Lean Blowoff Limits of Fuel Flexible Burners Operating on Gaseous Renewable and Fossil Fuels

NASA Astrophysics Data System (ADS)

Colorado, Andres

This study provides an experimental and numerical examination of pollutant emissions and stability of gaseous fueled reactions stabilized with two premixed-fuel-flexible and ultra-low NOx burner technologies. Both burners feature lean combustion technology to control the formation of nitrogen oxides (NOx). The first fuel--flexible burner is the low-swirl burner (LSB), which features aerodynamic stabilization of the reactions with a divergent flow-field; the second burner is the surface stabilized combustion burner (SSCB), which features the stabilization of the reactions on surface patterns. For combustion applications the most commonly studied species are: NOx, carbon monoxide (CO), and unburned hydrocarbons (UHC). However these are not the only pollutants emitted when burning fossil fuels; other species such as nitrous oxide (N2O), ammonia (NH3) and formaldehyde (CH2O) can be directly emitted from the oxidation reactions. Yet the conditions that favor the emission of these pollutants are not completely understood and require further insight. The results of this dissertation close the gap existing regarding the relations between emission of pollutants species and stability when burning variable gaseous fuels. The results of this study are applicable to current issues such as: 1. Current combustion systems operating at low temperatures to control formation of NOx. 2. Increased use of alternative fuels such as hydrogen, synthetic gas and biogas. 3. Increasing recognition of the need/desire to operate combustion systems in a transient manner to follow load and to offset the intermittency of renewable power. 4. The recent advances in measurement methods allow us to quantify other pollutants, such as N 2O, NH3 and CH2O. Hence in this study, these pollutant species are assessed when burning natural gas (NG) and its binary mixtures with other gaseous fuels such as hydrogen (H2), carbon dioxide (CO2), ethane (C 2H6) and propane (C3H8) at variable operation modes including: ignition; lean blowoff; and variable air to fuel ratio. Some remarkable results of this dissertation include: • At a fixed fire rate (117kW) the addition of hydrogen to NG raises the emission of NO x for the reactions stabilized with the LSB. Under the same conditions, the addition of H2 to NG will reduce the emission levels of the reactions stabilized with the SSCB. • It was found experimentally that nitrous oxide (N2O) is emitted during ignition and blowoff events. • Ammonia (NH3) is also emitted during ignition and blowoff events. • It was found experimentally that at high concentrations of hydrogen in NG (H2>70%), reactions aerodynamically stabilized with the LSB will emit significant amounts of N2O.

Ghrelin receptor controls obesity by fat burning

USDA-ARS?s Scientific Manuscript database

Emerging evidence show that brown fat in the body produces heat to burn energy, thus prompting weight loss. Ghrelin is the only known hormone which increases appetite and promotes weight gain. We have reported that mice that lack the receptor which mediates the functions of ghrelin are lean. Our fu...

NASA GRC's High Pressure Burner Rig Facility and Materials Test Capabilities

NASA Technical Reports Server (NTRS)

Robinson, R. Craig

1999-01-01

The High Pressure Burner Rig (HPBR) at NASA Glenn Research Center is a high-velocity. pressurized combustion test rig used for high-temperature environmental durability studies of advanced materials and components. The facility burns jet fuel and air in controlled ratios, simulating combustion gas chemistries and temperatures that are realistic to those in gas turbine engines. In addition, the test section is capable of simulating the pressures and gas velocities representative of today's aircraft. The HPBR provides a relatively inexpensive. yet sophisticated means for researchers to study the high-temperature oxidation of advanced materials. The facility has the unique capability of operating under both fuel-lean and fuel-rich gas mixtures. using a fume incinerator to eliminate any harmful byproduct emissions (CO, H2S) of rich-burn operation. Test samples are easily accessible for ongoing inspection and documentation of weight change, thickness, cracking, and other metrics. Temperature measurement is available in the form of both thermocouples and optical pyrometery. and the facility is equipped with quartz windows for observation and video taping. Operating conditions include: (1) 1.0 kg/sec (2.0 lbm/sec) combustion and secondary cooling airflow capability: (2) Equivalence ratios of 0.5- 1.0 (lean) to 1.5-2.0 (rich), with typically 10% H2O vapor pressure: (3) Gas temperatures ranging 700-1650 C (1300-3000 F): (4) Test pressures ranging 4-12 atmospheres: (5) Gas flow velocities ranging 10-30 m/s (50-100) ft/sec.: and (6) Cyclic and steady-state exposure capabilities. The facility has historically been used to test coupon-size materials. including metals and ceramics. However complex-shaped components have also been tested including cylinders, airfoils, and film-cooled end walls. The facility has also been used to develop thin-film temperature measurement sensors.

EFFECTS OF DIFFERENT DURATION EXERCISE PROGRAMS IN CHILDREN WITH SEVERE BURNS

PubMed Central

Clayton, Robert P.; Wurzer, Paul; Andersen, Clark R.; Mlcak, Ronald P.; Herndon, David N.; Suman, Oscar E.

2016-01-01

Introduction Burns lead to persistent and detrimental muscle breakdown and weakness. Standard treatment at our institution includes a voluntary 12-week rehabilitative exercise program to limit and reverse the effects of increased muscle catabolism. In the present work, we investigated if different durations of exercise, 6 or 12 weeks, produce comparable improvements in muscle strength, body composition, and cardiopulmonary fitness. Methods We prospectively enrolled and randomized patients with ≥30% total body surface area (TBSA) burned to receive 6- or 12-weeks of exercise rehabilitation. Patients were evaluated for muscle strength, oxygen consumption capacity, and lean body mass at discharge (n = 42) and post exercise. After 6 weeks (n = 18) or 12 weeks (n = 24) of exercise training, leg muscle strength was assessed as peak torque per body weight using a Biodex Isokinetic Dynamometer. Oxygen consumption capacity, measured as peak VO2, was studied using a standard treadmill-based test, and lean body mass was determined using dual-energy X-ray absorptiometry. Results Significant improvements in muscle strength, peak VO2, and lean body mass were seen after 6 weeks of exercise training (p<0.001), with only significant improvements in peak VO2 being seen after 6 weeks more of training. Conclusion These data suggest that a 6-week rehabilitative exercise program is sufficient for improving muscle strength, body composition, and cardiopulmonary fitness in pediatric burn patients. However, continuation of at- or near-home cardiopulmonary training following the 6 weeks of at-hospital rehabilitation may be useful. PMID:27908464

Effects of Community-Based Exercise in Children with Severe Burns: A Randomized Trial

PubMed Central

Peña, Raquel; Ramirez, Leybi L.; Crandall, Craig G.; Wolf, Steven; Herndon, David N.; Suman, Oscar E.

2015-01-01

Objective To counteract long-lasting muscle break down, muscle weakness, and poor physical fitness resulting from severe burns, we recommend a 12-week in-hospital exercise training rehabilitation program. Unfortunately, this in-hospital training program requires time away from home, family, school or work). This study was undertaken to evaluate an alternative exercise rehabilitation strategy involving a 12-week community-based exercise training rehabilitation program (COMBEX) carried out at or near the patient and caretaker’s home. Study Design and Participants Pediatric patients (7–18 years) with ≥ 30% of the total body surface area (TBSA) burns were randomized to participate in COMBEX (N=12) or an outpatient exercise program (EX) at the hospital (N=22). Both programs were started after hospital discharge and consisted of 12 weeks of progressive resistive and aerobic exercise. COMBEX was performed in community fitness centers near the patients’ home. Endpoints were assessed at discharge (pre-exercise) and after the 12-week program. Primary endpoints were lean body mass (dual energy x-ray absorptiometry), muscle strength (isokinetic dynamometry), and peak aerobic capacity (indirect calorimetry). Results Demographics, length of hospitalization, and TBSA burned were comparable between groups (p>0.05). Both groups exhibited a significant (p≤0.01 for all) increase (mean ± SEM) in lean muscle mass (EX: 6.9 ± 1.7%; COMBEX: 6.5 ± 1.1%), muscle strength (EX: 67.1 ± 7.0%; COMBEX: 49.9 ± 6.8%), and peak aerobic capacity (EX: 35.5 ± 4.0%; COMBEX: 46.9 ± 7.7%). Furthermore, the magnitude of these increases were not different between groups (P>0.12). Conclusions Both EX and COMBEX are efficacious in improving lean mass, strength, and cardiopulmonary capacity in severely burned children. PMID:26643401

Lean burn combustor technology at GE Aircraft Engines

NASA Technical Reports Server (NTRS)

Dodds, Willard J.

1992-01-01

This presentation summarizes progress to date at GE Aircraft Engines in demonstration of a lean combustion system for the High Speed Civil Transport (HSCT). These efforts were supported primarily by NASA contracts, with the exception of initial size and weight estimates and development of advanced diagnostics which were conducted under GE Independent Research and Development projects. Key accomplishments to date are summarized below.

Advanced materials for automobiles

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

Narula, C.K.; Allison, J.E.; Bauer, D.R.

Quite early on, manufacturers realized that lighter automobiles (with gas and diesel engines) would be more fuel efficient and produce fewer tailpipe emissions. They also realized that burning diesel fuel at elevated temperatures (1,315 C) would result in similar improvements. However, materials limitations prevent the operation of diesel vehicles at high temperatures. The fuel efficiency of gasoline-powered vehicles is currently improved by reducing the weight of the automobile and treated the emissions with a three-way catalyst. Additional improvements can be achieved with the use of advanced materials that reduce the weight of vehicles without compromising safety. The use of ceramics,more » fiber-reinforced plastics, and metal-matrix composites are discussed. The paper also discusses automotive catalysts and their components, electrically heated catalyst devices, a lean-burn NOx catalyst, and the future for materials chemistry.« less

What Is Lean Management in Health Care? Development of an Operational Definition for a Cochrane Systematic Review.

PubMed

Rotter, Thomas; Plishka, Christopher; Lawal, Adegboyega; Harrison, Liz; Sari, Nazmi; Goodridge, Donna; Flynn, Rachel; Chan, James; Fiander, Michelle; Poksinska, Bonnie; Willoughby, Keith; Kinsman, Leigh

2018-01-01

Industrial improvement approaches such as Lean management are increasingly being adopted in health care. Synthesis is necessary to ensure these approaches are evidence based and requires operationalization of concepts to ensure all relevant studies are included. This article outlines the process utilized to develop an operational definition of Lean in health care. The literature search, screening, data extraction, and data synthesis processes followed the recommendations outlined by the Cochrane Collaboration. Development of the operational definition utilized the methods prescribed by Kinsman et al. and Wieland et al. This involved extracting characteristics of Lean, synthesizing similar components to establish an operational definition, applying this definition, and updating the definition to address shortcomings. We identified two defining characteristics of Lean health-care management: (1) Lean philosophy, consisting of Lean principles and continuous improvement, and (2) Lean activities, which include Lean assessment activities and Lean improvement activities. The resulting operational definition requires that an organization or subunit of an organization had integrated Lean philosophy into the organization's mandate, guidelines, or policies and utilized at least one Lean assessment activity or Lean improvement activity. This operational definition of Lean management in health care will act as an objective screening criterion for our systematic review. To our knowledge, this is the first evidence-based operational definition of Lean management in health care.

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.

Experimental study of the effect of cycle pressure on lean combustion emissions

NASA Technical Reports Server (NTRS)

Roffe, G.; Venkataramani, K. S.

1978-01-01

Experiments were conducted in which a stream of premixed propane and air was burned under conditions representative of gas turbine operation. Emissions of NOx, CO, and unburned hydrocarbons (UHC) were measured over a range of combustor inlet temperature, pressure, and residence time at equivalence ratios from 0.7 down to the lean stability limit. At an inlet temperature of 600 K, observed NOx levels dropped markedly with decreasing pressure for pressures below 20 atm. The NOx levels are proportional to combustor residence time and formation rates were principally a function of adiabatic flame temperature. For adiabatic flame temperatures of 2050 K and higher, CO reached chemical equilibrium within 2 msec. Unburned hydrocarbon species dropped to a negligible level within 2 msec regardless of inlet temperature, pressure, or equivalence ratio. For a combustor residence time of 2.5 msec, combustion inefficiency became less than 0.01% at an adiabatic flame temperature of 2050 K. The maximum combustion inefficiency observed was on the order of 1% and corresponded to conditions near the lean stability limit. Using a perforated plate flameholder, this limit is well represented by the condition of 1800 K adiabatic flame temperature.

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Stationary Non-Emergency SI Engines â¥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI Landfill... Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI...-Emergency SI Natural Gas b and Non-Emergency SI Lean Burn LPG b 100≤HP HP 25 HP Table 1 to Subpart JJJJ of...

76 FR 17368 - Approval and Promulgation of Air Quality Implementation Plans; Louisiana; Determination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... failed to attain the 1-hour ozone standard by their attainment date. South Coast Air Quality Management... rationale for this action? \\3\\ As a result of the court decision in South Coast Air Quality Management.../MMBtu. Stationary Internal Combustion Engines: Lean-burn engines > 150 to 320 Hp 4 g/Hp-hr. Rich-burn...

Effects of different duration exercise programs in children with severe burns.

PubMed

Clayton, Robert P; Wurzer, Paul; Andersen, Clark R; Mlcak, Ronald P; Herndon, David N; Suman, Oscar E

2017-06-01

Burns lead to persistent and detrimental muscle breakdown and weakness. Standard treatment at our institution includes a voluntary 12-week rehabilitative exercise program to limit and reverse the effects of increased muscle catabolism. In the present work, we investigated if different durations of exercise, 6 or 12 weeks, produce comparable improvements in muscle strength, body composition, and cardiopulmonary fitness. We prospectively enrolled and randomized patients with ≥30% total body surface area (TBSA) burned to receive 6 or 12 weeks of exercise rehabilitation. Patients were evaluated for muscle strength, oxygen consumption capacity, and lean body mass at discharge (n=42) and after exercise. After 6 weeks (n=18) or 12 weeks (n=24) of exercise training, leg muscle strength was assessed as peak torque per body weight using a Biodex isokinetic dynamometer. Oxygen consumption capacity, measured as peak VO 2 , was studied using a standard treadmill-based test, and lean body mass was determined using dual-energy X-ray absorptiometry. Significant improvements in muscle strength, peak VO 2 , and lean body mass were seen after 6 weeks of exercise training (p<0.001), with only significant improvements in peak VO 2 being seen after 6 weeks more of training. These data suggest that a 6-week rehabilitative exercise program is sufficient for improving muscle strength, body composition, and cardiopulmonary fitness in pediatric burn patients. However, continuation of at- or near-home cardiopulmonary training following the 6 weeks of at-hospital rehabilitation may be useful. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Experimental and Computational Study of Trapped Vortex Combustor Sector Rig With Tri-Pass Diffuser

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Shouse, D. T.; Roquernore, W. M.; Burrus, D. L.; Duncan, B. S.; Ryder, R. C.; Brankovic, A.; Liu, N.-S.; Gallagher, J. R.; Hendricks, J. A.

2004-01-01

The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Stationary Non-Emergency SI Engines â¥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI Landfill... Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI...-Emergency SI Natural Gas b and Non-Emergency SI Lean Burn LPG b 100≤HP<500 7/1/2008 2.0 4.0 1.0 160 540 86 1...

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Stationary Non-Emergency SI Engines â¥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI Landfill... Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI...-Emergency SI Natural Gas b and Non-Emergency SI Lean Burn LPG b 100≤HP<500 7/1/2008 2.0 4.0 1.0 160 540 86 1...

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Stationary Non-Emergency SI Engines â¥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI Landfill... Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI...-Emergency SI Natural Gas b and Non-Emergency SI Lean Burn LPG b 100≤HP<500 7/1/2008 2.0 4.0 1.0 160 540 86 1...

Relationship Between Lean Production and Operational Performance in the Manufacturing Industry

NASA Astrophysics Data System (ADS)

Rasi, Raja Zuraidah R. M.; Syamsyul Rakiman, Umol; Ahmad, Md Fauzi Bin

2015-05-01

Nowadays, more and more manufacturing firms have started to implement lean production system in their operations. Lean production viewed as one of the mechanism to maintain the organisation's position and to compete globally. However, many fail to apply the lean concepts successfully in their operations. Based on previous studies, implementation of lean production in the manufacturing industry is more focused on the relationship between Lean and Operational Performance of one dimension only. Therefore, this study attempted to examine the relationship between Lean Production (LP) and Operational Performance in 4 dimensions which are quality, delivery, cost and flexibility. This study employed quantitative study using questionnaires. Data was collected from 50 manufacturing industries. The data was analysed using Statistical Package for Social Science (SPSS) 22.0. This study is hoped to shed new understanding on the concept of Lean Production (LP) in regards of Operational Performance covering the 4 dimensions.

Mixed-Potential NO x and NH 3 Sensors Fabricated by Commercial Manufacturing Methods [Mixed-Potential Sensors NO x and NH 3 Fabricated by Commercial Manufacturing Methods

DOE PAGES

Kreller, Cortney R.; Spernjak, Dusan; Li, Wenxia; ...

2014-08-12

Meeting EPA Tier 3 emissions reduction requirements while simultaneously increasing fuel economy to meet new CAFE standards will require optimization of advanced combustion strategies and emissions control technologies. There is an immediate need for suitable exhaust gas sensor technologies to monitor internal combustion engine tailpipe emissions and to control and maintain efficient operation of the engine and exhaust after treatment systems. NH 3, NO x, and HC sensors could enable onboard diagnostics and combustion control in lean-burn engines, analogous to the role of O 2 sensors in stoichiometric burn engines. Commercial manufacturing methods have been used to fabricate self-heated mixed-potentialmore » sensors in a planar automotive configuration. By altering materials composition and operating conditions, we are able to obtain sensitivity/selectivity to each NH 3, NO x and HCs. In addition, these devices exhibit stable performance over months of testing as a result of the stable morphology of the electrode/electrolyte/gas three-phase interface.« less

Experimental Investigation of Premixed Turbulent Hydrocarbon/Air Bunsen Flames

NASA Astrophysics Data System (ADS)

Tamadonfar, Parsa

Through the influence of turbulence, the front of a premixed turbulent flame is subjected to the motions of eddies that leads to an increase in the flame surface area, and the term flame wrinkling is commonly used to describe it. If it is assumed that the flame front would continue to burn locally unaffected by the stretch, then the total turbulent burning velocity is expected to increase proportionally to the increase in the flame surface area caused by wrinkling. When the turbulence intensity is high enough such that the stretch due to hydrodynamics and flame curvature would influence the local premixed laminar burning velocity, then the actual laminar burning velocity (that is, flamelet consumption velocity) should reflect the influence of stretch. To address this issue, obtaining the knowledge of instantaneous flame front structures, flame brush characteristics, and burning velocities of premixed turbulent flames is necessary. Two axisymmetric Bunsen-type burners were used to produce premixed turbulent flames, and three optical measurement techniques were utilized: Particle image velocimetry to measure the turbulence statistics; Rayleigh scattering method to measure the temperature fields of premixed turbulent flames, and Mie scattering method to visualize the flame front contours of premixed turbulent flames. Three hydrocarbons (methane, ethane, and propane) were used as the fuel in the experiments. The turbulence was generated using different perforated plates mounted upstream of the burner exit. A series of comprehensive parameters including the thermal flame front thickness, characteristic flame height, mean flame brush thickness, mean volume of the turbulent flame region, two-dimensional flame front curvature, local flame front angle, two-dimensional flame surface density, wrinkled flame surface area, turbulent burning velocity, mean flamelet consumption velocity, mean turbulent flame stretch factor, mean turbulent Markstein length and number, and mean fuel consumption rate were systematically evaluated from the experimental data. The normalized preheat zone and reaction zone thicknesses decreased with increasing non-dimensional turbulence intensity in ultra-lean premixed turbulent flames under a constant equivalence ratio of 0.6, whereas they increased with increasing equivalence ratios from 0.6 to 1.0 under a constant bulk flow velocity. The normalized preheat zone and reaction zone thicknesses showed no overall trend with increasing non-dimensional longitudinal integral length scale. The normalized preheat zone and reaction zone thicknesses decreased by increasing the Karlovitz number, suggesting that increasing the total stretch rate is the controlling mechanism in the reduction of flame front thickness for the experimental conditions studied in this thesis. In general, the leading edge and half-burning surface turbulent burning velocities were enhanced with increasing equivalence ratio from lean to stoichiometric mixtures, whereas they decreased with increasing equivalence ratio for rich mixtures. These velocities were enhanced with increasing total turbulence intensity. The leading edge and half-burning surface turbulent burning velocities for lean/stoichiometric mixtures were observed to be smaller than that for rich mixtures. The mean turbulent flame stretch factor displayed a dependence on the equivalence ratio and turbulence intensity. Results show that the mean turbulent flame stretch factors for lean/stoichiometric and rich mixtures were not equal when the unstrained premixed laminar burning velocity, non-dimensional bulk flow velocity, non-dimensional turbulence intensity, and non-dimensional longitudinal integral length scale were kept constant.

Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2014-01-01

Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 deg is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

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.

Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2015-01-01

Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 degrees is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

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

Prikhodko, Vitaly Y; Pihl, Josh A; Toops, Todd J

Ethanol is a very effective reductant of nitrogen oxides (NOX) over silver/alumina (Ag/Al2O3) catalysts in lean exhaust environment. With the widespread availability of ethanol/gasoline-blended fuel in the USA, lean gasoline engines equipped with an Ag/Al2O3 catalyst have the potential to deliver higher fuel economy than stoichiometric gasoline engines and to increase biofuel utilization while meeting exhaust emissions regulations. In this work a pre-commercial 2 wt% Ag/Al2O3 catalyst was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine for the selective catalytic reduction (SCR) of NOX with ethanol/gasoline blends. The ethanol/gasoline blends were delivered via in-pipe injection upstream ofmore » the Ag/Al2O3 catalyst with the engine operating under lean conditions. A number of engine conditions were chosen to provide a range of temperatures and space velocities for the catalyst performance evaluations. High NOX conversions were achieved with ethanol/gasoline blends containing at least 50% ethanol; however, higher C1/N ratio was needed to achieve greater than 90% NOX conversion, which also resulted in significant HC slip. Temperature and HC dosing were important in controlling selectivity to NH3 and N2O. At high temperatures, NH3 and N2O yields increased with increased HC dosing. At low temperatures, NH3 yield was very low, however, N2O levels became significant. The ability to generate NH3 under lean conditions has potential for application of a dual SCR approach (HC SCR + NH3 SCR) to reduce fuel consumption needed for NOX reduction and/or increased NOX conversion, which is discussed in this work.« less

Emissions of nitrogen oxides from an experimental hydrogen-fueled gas turbine combustor

NASA Technical Reports Server (NTRS)

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

1974-01-01

The effect of operating variables of a hydrogen fueled combustor on exhaust concentrations of total oxides of nitrogen was determined at inlet-air temperature levels up to 810 K, pressure of 414,000N/sa m, and reference velocity of 21.3 m/sec. The combustor, which was originally designed for hydrocarbon fuel produced a NO(x) concentration of 380 ppm with hydrogen at 810 K inlet-air temperature. A reduction in NO(x) of about 30 % was obtained by modification to a lean or rich primary zone. The lowest NO(x) levels obtained with hydrogen were equivalent to those of the reference combustor burning hydrocarbon fuels.

Measurement and Computation of Supersonic Flow in a Lobed Diffuser-Mixer for Trapped Vortex Combustors

NASA Technical Reports Server (NTRS)

Brankovic, Andreja; Ryder, Robert C., Jr.; Hendricks, Robert C.; Liu, Nan-Suey; Gallagher, John R.; Shouse, Dale T.; Roquemore, W. Melvyn; Cooper, Clayton S.; Burrus, David L.; Hendricks, John A.

2002-01-01

The trapped vortex combustor (TVC) pioneered by Air Force Research Laboratories (AFRL) is under consideration as an alternative to conventional gas turbine combustors. The TVC has demonstrated excellent operational characteristics such as high combustion efficiency, low NO(x) emissions, effective flame stabilization, excellent high-altitude relight capability, and operation in the lean-burn or rich burn-quick quench-lean burn (RQL) modes of combustion. It also has excellent potential for lowering the engine combustor weight. This performance at low to moderate combustor mach numbers has stimulated interest in its ability to operate at higher combustion mach number, and for aerospace, this implies potentially higher flight mach numbers. To this end, a lobed diffuser-mixer that enhances the fuel-air mixing in the TVC combustor core was designed and evaluated, with special attention paid to the potential shock system entering the combustor core. For the present investigation, the lobed diffuser-mixer combustor rig is in a full annular configuration featuring sixfold symmetry among the lobes, symmetry within each lobe, and plain parallel, symmetric incident flow. During hardware cold-flow testing, significant discrepancies were found between computed and measured values for the pitot-probe-averaged static pressure profiles at the lobe exit plane. Computational fluid dynamics (CFD) simulations were initiated to determine whether the static pressure probe was causing high local flow-field disturbances in the supersonic flow exiting the diffuser-mixer and whether shock wave impingement on the pitot probe tip, pressure ports, or surface was the cause of the discrepancies. Simulations were performed with and without the pitot probe present in the modeling. A comparison of static pressure profiles without the probe showed that static pressure was off by nearly a factor of 2 over much of the radial profile, even when taking into account potential axial displacement of the probe by up to 0.25 in. (0.64 cm). Including the pitot probe in the CFD modeling and data interpretation lead to good agreement between measurement and prediction. Graphical inspection of the results showed that the shock waves impinging on the probe surface were highly nonuniform, with static pressure varying circumferentially among the pressure ports by over 10 percent in some cases. As part of the measurement methodology, such measurements should be routinely supplemented with CFD analyses that include the pitot probe as part of the flow-path geometry.

Effect of vane twist on the performance of dome swirlers for gas turbine airblast atomizers

NASA Technical Reports Server (NTRS)

Micklow, Gerald J.; Dogra, Anju S.; Nguyen, H. Lee

1990-01-01

For advanced gas turbine engines, two combustor systems, the lean premixed/prevaporized (LPP) and the rich burn/quick quench/lean burn (RQL) offer great potential for reducing NO(x) emissions. An important consideration for either concept is the development of an advanced fuel injection system that will provide a stable, efficient, and very uniform combustion system over a wide operating range. High-shear airblast fuel injectors for gas turbine combustors have exhibited superior atomization and mixing compared with pressure-atomizing fuel injectors. This improved mixing has lowered NO(x) emissions and the pattern factor, and has enabled combustors to alternate fuels while maintaining a stable, efficient combustion system. The performance of high-shear airblast fuel injectors is highly dependent on the design of the dome swirl vanes. The type of swirl vanes most widely used in gas turbine combustors are usually flat for ease of manufacture, but vanes with curvature will, in general, give superior aerodynamic performance. The design and performance of high-turning, low-loss curved dome swirl vanes with twist along the span are investigated. The twist induces a secondary vortex flow pattern which will improve the atomization of the fuel, thereby producing a more uniform fuel-air distribution. This uniform distribution will increase combustion efficiency while lowering NO(x) emissions. A systematic swirl vane design system is presented based on one-, two-, and three-dimensional flowfield calculations, with variations in vane-turning angle, rate of turning, vane solidity, and vane twist as design parameters.

Effect of vane twist on the performance of dome swirlers for gas turbine airblast atomizers

NASA Astrophysics Data System (ADS)

Micklow, Gerald J.; Dogra, Anju S.; Nguyen, H. Lee

1990-07-01

For advanced gas turbine engines, two combustor systems, the lean premixed/prevaporized (LPP) and the rich burn/quick quench/lean burn (RQL) offer great potential for reducing NO(x) emissions. An important consideration for either concept is the development of an advanced fuel injection system that will provide a stable, efficient, and very uniform combustion system over a wide operating range. High-shear airblast fuel injectors for gas turbine combustors have exhibited superior atomization and mixing compared with pressure-atomizing fuel injectors. This improved mixing has lowered NO(x) emissions and the pattern factor, and has enabled combustors to alternate fuels while maintaining a stable, efficient combustion system. The performance of high-shear airblast fuel injectors is highly dependent on the design of the dome swirl vanes. The type of swirl vanes most widely used in gas turbine combustors are usually flat for ease of manufacture, but vanes with curvature will, in general, give superior aerodynamic performance. The design and performance of high-turning, low-loss curved dome swirl vanes with twist along the span are investigated. The twist induces a secondary vortex flow pattern which will improve the atomization of the fuel, thereby producing a more uniform fuel-air distribution. This uniform distribution will increase combustion efficiency while lowering NO(x) emissions. A systematic swirl vane design system is presented based on one-, two-, and three-dimensional flowfield calculations, with variations in vane-turning angle, rate of turning, vane solidity, and vane twist as design parameters.

Effect of vane twist on the performance of dome swirlers for gas turbine airblast atomizers

NASA Astrophysics Data System (ADS)

Micklow, Gerald J.; Dogra, Anju S.; Nguyen, H. Lee

1990-06-01

For advanced gas turbine engines, two combustor systems, the lean premixed/prevaporized (LPP) and the rich burn/quick quench/lean burn (RQL) offer great potential for reducing NO(x) emissions. An important consideration for either concept is the development of an advanced fuel injection system that will provide a stable, efficient, and very uniform combustion system over a wide operating range. High-shear airblast fuel injectors for gas turbine combustors have exhibited superior atomization and mixing compared with pressure-atomizing fuel injectors. This improved mixing has lowered NO(x) emissions and the pattern factor, and has enabled combustors to alternate fuels while maintaining a stable, efficient combustion system. The performance of high-shear airblast fuel injectors is highly dependent on the design of the dome swirl vanes. The type of swirl vanes most widely used in gas turbine combustors are usually flat for ease of manufacture, but vanes with curvature will, in general, give superior aerodynamic performance. The design and performance of high-turning, low-loss curved dome swirl vanes with twist along the span are investigated. The twist induces a secondary vortex flow pattern which will improve the atomization of the fuel, thereby producing a more uniform fuel-air distribution. This uniform distribution will increase combustion efficiency while lowering NO(x) emissions. A systematic swirl vane design system is presented based on one-, two-, and three-dimensional flowfield calculations, with variations in vane-turning angle, rate of turning, vane solidity, and vane twist as design parameters.

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

Performance and operational improvements made to the Waukesha AT27-GL engine

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

Reinbold, E.O.

1996-12-31

This paper presents the results of combustion and engine performance studies performed on the AT27GL lean burn engine. One study was to evaluate the effect of the pre-combustion chamber cup geometry on engine performance under several operating conditions including: Air-Fuel Ratio (AFR), ignition timing, and engine load. The study examined several combustion parameters; including IMEP, coefficient of variation of IMEP, heat release rates, and maximum combustion pressures. The study also examined engine thermal efficiency, and brake specific emissions of Oxides of Nitrogen, Carbon Monoxide, and Total Hydrocarbons (gaseous). Studies were also performed on different spark plug designs, comparing firing voltages,more » and electrode temperatures while operating under conditions of varying AFR, and ignition timing. In addition an Air-Fuel-Ratio controller was recently tested and released on the engine. The controller was tested under conditions of varying fuel quality, along with a detonation control system.« less

Large Engine Technology Program. Task 21: Rich Burn Liner for Near Term Experimental Evaluations

NASA Technical Reports Server (NTRS)

Hautman, D. J.; Padget, F. C.; Kwoka, D.; Siskind, K. S.; Lohmann, R. P.

2005-01-01

The objective of the task reported herein, which was conducted as part of the NASA sponsored Large Engine Technology program, was to define and evaluate a near-term rich-zone liner construction based on currently available materials and fabrication processes for a Rich-Quench-Lean combustor. This liner must be capable of operation at the temperatures and pressures of simulated HSCT flight conditions but only needs sufficient durability for limited duration testing in combustor rigs and demonstrator engines in the near future. This must be achieved at realistic cooling airflow rates since the approach must not compromise the emissions, performance, and operability of the test combustors, relative to the product engine goals. The effort was initiated with an analytical screening of three different liner construction concepts. These included a full cylinder metallic liner and one with multiple segments of monolithic ceramic, both of which incorporated convective cooling on the external surface using combustor airflow that bypassed the rich zone. The third approach was a metallic platelet construction with internal convective cooling. These three metal liner/jacket combinations were tested in a modified version of an existing Rich-Quench-Lean combustor rig to obtain data for heat transfer model refinement and durability verification.

Exhaust gas purification system for lean burn engine

DOEpatents

Haines, Leland Milburn

2002-02-19

An exhaust gas purification system for a lean burn engine includes a thermal mass unit and a NO.sub.x conversion catalyst unit downstream of the thermal mass unit. The NO.sub.x conversion catalyst unit includes at least one catalyst section. Each catalyst section includes a catalytic layer for converting NO.sub.x coupled to a heat exchanger. The heat exchanger portion of the catalyst section acts to maintain the catalytic layer substantially at a desired temperature and cools the exhaust gas flowing from the catalytic layer into the next catalytic section in the series. In a further aspect of the invention, the exhaust gas purification system includes a dual length exhaust pipe upstream of the NO.sub.x conversion catalyst unit. The dual length exhaust pipe includes a second heat exchanger which functions to maintain the temperature of the exhaust gas flowing into the thermal mass downstream near a desired average temperature.

Resistive oxygen sensor using ceria-zirconia sensor material and ceria-yttria temperature compensating material for lean-burn engine.

PubMed

Izu, Noriya; Nishizaki, Sayaka; Shin, Woosuck; Itoh, Toshio; Nishibori, Maiko; Matsubara, Ichiro

2009-01-01

Temperature compensating materials were investigated for a resistive oxygen sensor using Ce(0.9)Zr(0.1)O(2) as a sensor material for lean-burn engines. The temperature dependence of a temperature compensating material should be the same as the sensor material; therefore, the Y concentration in CeO(2)-Y(2)O(3) was optimized. The resistance of Ce(0.5)Y(0.5)O(2-δ) was independent of the air-to-fuel ratio (oxygen partial pressure), so that it was confirmed to function as a temperature compensating material. Sensor elements comprised of Ce(0.9)Zr(0.1)O(2) and Ce(0.5)Y(0.5)O(2-δ) were fabricated and the output was determined to be approximately independent of the temperature in the wide range from 773 to 1,073 K.

Experimental investigation and modeling of an aircraft Otto engine operating with gasoline and heavier fuels

NASA Astrophysics Data System (ADS)

Saldivar Olague, Jose

A Continental "O-200" aircraft Otto-cycle engine has been modified to burn diesel fuel. Algebraic models of the different processes of the cycle were developed from basic principles applied to a real engine, and utilized in an algorithm for the simulation of engine performance. The simulation provides a means to investigate the performance of the modified version of the Continental engine for a wide range of operating parameters. The main goals of this study are to increase the range of a particular aircraft by reducing the specific fuel consumption of the engine, and to show that such an engine can burn heavier fuels (such as diesel, kerosene, and jet fuel) instead of gasoline. Such heavier fuels are much less flammable during handling operations making them safer than aviation gasoline and very attractive for use in flight operations from naval vessels. The cycle uses an electric spark to ignite the heavier fuel at low to moderate compression ratios, The stratified charge combustion process is utilized in a pre-chamber where the spray injection of the fuel occurs at a moderate pressure of 1200 psi (8.3 MPa). One advantage of fuel injection into the combustion chamber instead of into the intake port, is that the air-to-fuel ratio can be widely varied---in contrast to the narrower limits of the premixed combustion case used in gasoline engines---in order to obtain very lean combustion. Another benefit is that higher compression ratios can be attained in the modified cycle with heavier fuels. The combination of injection into the chamber for lean combustion, and higher compression ratios allow to limit the peak pressure in the cylinder, and to avoid engine damage. Such high-compression ratios are characteristic of Diesel engines and lead to increase in thermal efficiency without pre-ignition problems. In this experimental investigation, operations with diesel fuel have shown that considerable improvements in the fuel efficiency are possible. The results of simulations using performance models show that the engine can deliver up to 178% improvement in fuel efficiency and operating range, and reduce the specific fuel consumption to 58% when compared to gasoline. Directions for future research and other modifications to the proposed spark assisted cycle are also described.

Application of lean thinking to health care: issues and observations

PubMed Central

Joosten, Tom; Bongers, Inge; Janssen, Richard

2009-01-01

Background Incidents and quality problems are a prime cause why health care leaders are calling to redesign health care delivery. One of the concepts used is lean thinking. Yet, lean often leads to resistance. Also, there is a lack of high quality evidence supporting lean premises. In this paper, we present an overview of lean thinking and its application to health care. Development, theory and application of lean thinking to health care Lean thinking evolved from a tool designed to improve operational shop-floor performance at an automotive manufacturer to a management approach with both operational and sociotechnical aspects. Sociotechnical dynamics have until recently not received much attention. At the same time a balanced approach might lead to a situation where operational and sociotechnial improvements are mutually reinforcing. Application to health care has been limited and focussed mainly on operational aspects using original lean tools. A more integrative approach would be to pay more attention to sociotechnical dynamics of lean implementation efforts. Also, the need to use the original lean tools may be limited, because health care may have different instruments and tools already in use that are in line with lean thinking principles. Discussion We believe lean thinking has the potential to improve health care delivery. At the same time, there are methodological and practical considerations that need to be taken into account. Otherwise, lean implementation will be superficial and fail, adding to existing resistance and making it more difficult to improve health care in the long term. PMID:19696048

Slag processing system for direct coal-fired gas turbines

DOEpatents

Pillsbury, Paul W.

1990-01-01

Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The gas turbine system includes a primary zone for burning coal in the presence of compressed air to produce hot combustion gases and debris, such as molten slag. The turbine system further includes a secondary combustion zone for the lean combustion of the hot combustion gases. The operation of the system is improved by the addition of a cyclone separator for removing debris from the hot combustion gases. The cyclone separator is disposed between the primary and secondary combustion zones and is in pressurized communication with these zones. In a novel aspect of the invention, the cyclone separator includes an integrally disposed impact separator for at least separating a portion of the molten slag from the hot combustion gases.

Ultralean low swirl burner

DOEpatents

Cheng, R.K.

1998-04-07

A novel burner and burner method has been invented which burns an ultra lean premixed fuel-air mixture with a stable flame. The inventive burning method results in efficient burning and much lower emissions of pollutants such as oxides of nitrogen than previous burners and burning methods. The inventive method imparts weak swirl (swirl numbers of between about 0.01 to 3.0) on a fuel-air flow stream. The swirl, too small to cause recirculation, causes an annulus region immediately inside the perimeter of the fuel-air flow to rotate in a plane normal to the axial flow. The rotation in turn causes the diameter of the fuel-air flow to increase with concomitant decrease in axial flow velocity. The flame stabilizes where the fuel-air mixture velocity equals the rate of burning resulting in a stable, turbulent flame. 11 figs.

Ultralean low swirl burner

DOEpatents

Cheng, Robert K.

1998-01-01

A novel burner and burner method has been invented which burns an ultra lean premixed fuel-air mixture with a stable flame. The inventive burning method results in efficient burning and much lower emissions of pollutants such as oxides of nitrogen than previous burners and burning methods. The inventive method imparts weak swirl (swirl numbers of between about 0.01 to 3.0) on a fuel-air flow stream. The swirl, too small to cause recirculation, causes an annulus region immediately inside the perimeter of the fuel-air flow to rotate in a plane normal to the axial flow. The rotation in turn causes the diameter of the fuel-air flow to increase with concomitant decrease in axial flow velocity. The flame stabilizes where the fuel-air mixture velocity equals the rate of burning resulting in a stable, turbulent flame.

Reacting flow studies in a dump combustor: Enhanced volumetric heat release rates and flame anchorability

NASA Astrophysics Data System (ADS)

Behrens, Alison Anne

Reacting flow studies in a novel dump combustor facility focused on increasing volumetric heat release rates, under stable burning conditions, and understanding the physical mechanisms governing flame anchoring in an effort to extend range and maneuverability of compact, low drag, air-breathing engines. Countercurrent shear flow was enhanced within the combustor as the primary control variable. Experiments were performed burning premixed JP10/air and methane/air in a dump combustor using reacting flow particle image velocimetry (PIV) and chemiluminescence as the primary diagnostics. Stable combustion studies burning lean mixtures of JP10/air aimed to increase volumetric heat release rates through the implementation of countercurrent shear control. Countercurrent shear flow was produced by creating a suction flow from a low pressure cavity connected to the dump combustor via a gap directly below the trailing edge. Chemiluminescence measurements showed that enhancing countercurrent shear within the combustor doubles volumetric heat release rates. PIV measurements indicate that counterflow acts to increase turbulent kinetic energy while maintaining constant strain rates. This acts to increase flame surface area through flame wrinkling without disrupting the integrity of the flame. Flame anchorability is one of the most important fundamental aspects to understand when trying to enhance turbulent combustion in a high-speed engine without increasing drag. Studies burning methane/air mixtures used reacting flow PIV to study flame anchoring. The operating point with the most stable flame anchor exhibited a correspondingly strong enthalpy flux of products into reactants via a single coherent structure positioned downstream of the step. However, the feature producing a strong flame anchor, i.e. a single coherent structure, also is responsible for combustion instabilities, therefore making this operating point undesirable. Counterflow control was found to create the best flow features for stable, robust, compact combustion. Enhancing countercurrent shear flow within a dump combustor enhances burning rates, provides a consistent pump of reaction-initiating combustion products required for sustained combustion, while maintaining flow three dimensionality needed to disrupt combustion instabilities. Future studies will focus on geometric and control scenarios that further reduce drag penalties while creating these same flow features found with countercurrent shear thus producing robust operating points.

Advanced Natural Gas Reciprocating Engine(s)

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

Pike, Edward

The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cyclemore » efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.« less

Optimizing clinical operations as part of a global emergency medicine initiative in Kumasi, Ghana: application of Lean manufacturing principals to low-resource health systems.

PubMed

Carter, Patrick M; Desmond, Jeffery S; Akanbobnaab, Christopher; Oteng, Rockefeller A; Rominski, Sarah D; Barsan, William G; Cunningham, Rebecca M

2012-03-01

Although many global health programs focus on providing clinical care or medical education, improving clinical operations can have a significant effect on patient care delivery, especially in developing health systems without high-level operations management. Lean manufacturing techniques have been effective in decreasing emergency department (ED) length of stay, patient waiting times, numbers of patients leaving without being seen, and door-to-balloon times for ST-elevation myocardial infarction in developed health systems, but use of Lean in low to middle income countries with developing emergency medicine (EM) systems has not been well characterized. To describe the application of Lean manufacturing techniques to improve clinical operations at Komfo Anokye Teaching Hospital (KATH) in Ghana and to identify key lessons learned to aid future global EM initiatives. A 3-week Lean improvement program focused on the hospital admissions process at KATH was completed by a 14-person team in six stages: problem definition, scope of project planning, value stream mapping, root cause analysis, future state planning, and implementation planning. The authors identified eight lessons learned during our use of Lean to optimize the operations of an ED in a global health setting: 1) the Lean process aided in building a partnership with Ghanaian colleagues; 2) obtaining and maintaining senior institutional support is necessary and challenging; 3) addressing power differences among the team to obtain feedback from all team members is critical to successful Lean analysis; 4) choosing a manageable initial project is critical to influence long-term Lean use in a new environment; 5) data intensive Lean tools can be adapted and are effective in a less resourced health system; 6) several Lean tools focused on team problem-solving techniques worked well in a low-resource system without modification; 7) using Lean highlighted that important changes do not require an influx of resources; and 8) despite different levels of resources, root causes of system inefficiencies are often similar across health care systems, but require unique solutions appropriate to the clinical setting. Lean manufacturing techniques can be successfully adapted for use in developing health systems. Lessons learned from this Lean project will aid future introduction of advanced operations management techniques in low- to middle-income countries. © 2012 by the Society for Academic Emergency Medicine.

Optimizing Clinical Operations as part of a Global Emergency Medicine Initiative in Kumasi, Ghana: Application of Lean Manufacturing Principals to Low Resource Health Systems

PubMed Central

Carter, Patrick M.; Desmond, Jeffery S.; Akanbobnaab, Christopher; Oteng, Rockefeller A.; Rominski, Sarah; Barsan, William G.; Cunningham, Rebecca

2012-01-01

Background Although many global health programs focus on providing clinical care or medical education, improving clinical operations can have a significant effect on patient care delivery, especially in developing health systems without high-level operations management. Lean manufacturing techniques have been effective in decreasing emergency department (ED) length of stay, patient waiting times, numbers of patients leaving without being seen, and door-to-balloon times for ST-elevation myocardial infarction in developed health systems; but use of Lean in low to middle income countries with developing emergency medicine systems has not been well characterized. Objectives To describe the application of Lean manufacturing techniques to improve clinical operations at Komfo Anokye Teaching Hospital in Ghana and to identify key lessons learned to aid future global EM initiatives. Methods A three-week Lean improvement program focused on the hospital admissions process at Komfo Anokye Teaching Hospital was completed by a 14-person team in six stages: problem definition, scope of project planning, value stream mapping, root cause analysis, future state planning, and implementation planning. Results The authors identified eight lessons learned during our use of Lean to optimize the operations of an ED in a global health setting: 1) the Lean process aided in building a partnership with Ghanaian colleagues; 2) obtaining and maintaining senior institutional support is necessary and challenging; 3) addressing power differences among the team to obtain feedback from all team members is critical to successful Lean analysis; 4) choosing a manageable initial project is critical to influence long-term Lean use in a new environment; 5) data intensive Lean tools can be adapted and are effective in a less resourced health system; 6) several Lean tools focused on team problem solving techniques worked well in a low resource system without modification; 7) using Lean highlighted that important changes do not require an influx of resources; 8) despite different levels of resources, root causes of system inefficiencies are often similar across health care systems, but require unique solutions appropriate to the clinical setting. Conclusions Lean manufacturing techniques can be successfully adapted for use in developing health systems. Lessons learned from this Lean project will aid future introduction of advanced operations management techniques in low to middle income countries. PMID:22435868

Great (Flame) Balls of Fire! Structure of Flame Balls at Low Lewis-number-2 (SOFBALL-2)

NASA Technical Reports Server (NTRS)

Ronney, Paul; Weiland, Karen J.; Over, Ann (Technical Monitor)

2002-01-01

Everyone knows that an automobile engine wastes fuel and energy when it runs with a fuel-rich mixture. 'Lean' burning, mixing in more air and less fuel, is better for the environment. But lean mixtures also lead to engine misfiring and rough operation. No one knows the ultimate limits for lean operation, for 'weak' combustion that is friendly to the environment while still moving us around. This is where the accidental verification of a decades-old prediction may have strong implications for designing and running low-emissions engines in the 21st century. In 1944, Soviet physicist Yakov Zeldovich predicted that stationary, spherical flames are possible under limited conditions in lean fuel-air mixtures. Dr. Paul Ronney of the University of Southern California accidentally discovered such 'flame balls' in experiments with lean hydrogen-air mixtures in 1984 during drop-tower experiments that provided just 2.2 seconds of near weightlessness. Experiments aboard NASA's low-g aircraft confirmed the results, but a thorough investigation was hampered by the aircraft's bumpy ride. And stable flame balls can only exist in microgravity. The potential for investigating combustion at the limits of flammability, and the implications for spacecraft fire safety, led to the Structure of Flame Balls at Low Lewis-number (SOFBALL) experiment flown twice aboard the Space Shuttle on the Microgravity Sciences Laboratory-1 (MSL-1) in 1997. Success there led to the planned reflight on STS-107. Flame balls are the weakest fires yet produced in space or on Earth. Typically each flame ball produced only 1 watt of thermal power. By comparison, a birthday candle produces 50 watts. The Lewis-number measures the rate of diffusion of fuel into the flame ball relative to the rate of diffusion of heat away from the flame ball. Lewis-number mixtures conduct heat poorly. Hydrogen and methane are the only fuels that provide low enough Lewis-numbers to produce stable flame balls, and even then only for very weak, barely flammable mixtures. Nevertheless, under these conditions flame balls give scientists the opportunity to test models in one of the simplest combustion experiments possible. SOFBALL-2 science objectives include: Improving our understanding of the flame ball phenomenon; Determining the conditions under which flame balls exist; Testing predictions of flame ball lifetimes; Acquiring more precise data for critical model comparison.

Summary of synfuel characterization and combustion studies

NASA Technical Reports Server (NTRS)

Schultz, D. F.

1983-01-01

Combustion component research studies aimed at evolving environmentally acceptable approaches for burning coal derived fuels for ground power applications were performed at the NASA Lewis Research Center under a program titled the ""Critical Research and Support Technology Program'' (CRT). The work was funded by the Department of Energy and was performed in four tasks. This report summarizes these tasks which have all been previously reported. In addition some previously unreported data from Task 4 is also presented. The first, Task 1 consisted of a literature survey aimed at determining the properties of synthetic fuels. This was followed by a computer modeling effort, Task 2, to predict the exhaust emissions resulting from burning coal liquids by various combustion techniques such as lean and rich-lean combustion. The computer predictions were then compared to the results of a flame tube rig, Task 3, in which the fuel properties were varied to simulate coal liquids. Two actual SRC 2 coal liquids were tested in this flame tube task.

Design and development of the Waukesha Custom Engine Control Air/Fuel Module

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

Moss, D.W.

1996-12-31

The Waukesha Custom Engine Control Air/Fuel Module (AFM) is designed to control the air-fuel ratio for all Waukesha carbureted, gaseous fueled, industrial engine. The AFM is programmed with a personal computer to run in one of four control modes: catalyst, best power, best economy, or lean-burn. One system can control naturally aspirated, turbocharged, in-line or vee engines. The basic system consists of an oxygen sensing system, intake manifold pressure transducer, electronic control module, actuator and exhaust thermocouple. The system permits correct operation of Waukesha engines in spite of changes in fuel pressure or temperature, engine load or speed, and fuelmore » composition. The system utilizes closed loop control and is centered about oxygen sensing technology. An innovative approach to applying oxygen sensors to industrial engines provides very good performance, greatly prolongs sensor life, and maintains sensor accuracy. Design considerations and operating results are given for application of the system to stationary, industrial engines operating on fuel gases of greatly varying composition.« less

Negativly streched premixed flames

NASA Astrophysics Data System (ADS)

Krikunova, A. I.; Saveliev, A. S.; Son, E. E.

2018-01-01

An experimental study of gravity effect on the blow-off and flash-back borders of the conical methane-air flame (normal and ring-stabilized) was performed. The influence of the preferential diffusion on the flame behavior in vicinity of flash-back boundaries was observed. Under conditions at Lewis number Le > 1, the radius of curvature of the flame tip increased gradually approaching flash-back boundaries while for the lean methane-air flames (Le < 1) the radius decreased abruptly. It was shown that the burning velocity for lean flames is less than that for reach ones, so the flash-back occurs at higher strains.

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.

Alternative Fuels Data Center

Science.gov Websites

advanced lean burn vehicles. Fleets that use fuel blends containing at least 20% biodiesel (B20) may earn Energy Independence and Security Act of 2007, including fleet management plan requirements (Section 142 infrastructure installation requirements (Section 246). For more information, see the Federal Fleet Management

Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

NASA Technical Reports Server (NTRS)

Sherlock, T. P.

1982-01-01

Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

A Survey of Studies on Ignition and Burn of Inertially Confined Fuels

NASA Astrophysics Data System (ADS)

Atzeni, Stefano

2016-10-01

A survey of studies on ignition and burn of inertial fusion fuels is presented. Potentials and issues of different approaches to ignition (central ignition, fast ignition, volume ignition) are addressed by means of simple models and numerical simulations. Both equimolar DT and T-lean mixtures are considered. Crucial issues concerning hot spot formation (implosion symmetry for central ignition; igniting pulse parameters for fast ignition) are briefly discussed. Recent results concerning the scaling of the ignition energy with the implosion velocity and constrained gain curves are also summarized.

Review of modern low emissions combustion technologies for aero gas turbine engines

NASA Astrophysics Data System (ADS)

Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Nalianda, Devaiah; Li, Yi-Guang; Wang, Lu

2017-10-01

Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of the review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.

Compression Ratio and Catalyst Aging Effects on Aqueous Ethanol Ignition (Year 2): Part 1. Compression Ratio Effects on Aqueous Ethanol Ignition

DOT National Transportation Integrated Search

2009-09-01

The lean burning of water ethanol blends has the potential to reduce NOx, CO, and HC emissions while reducing the ethanol fermentation production cost of distillation and dehydration. The torch style ignition produced by the catalytic igniter allows ...

The productive operating theatre and lean thinking systems.

PubMed

Kasivisvanathan, R; Chekairi, A

2014-11-01

The concept of 'lean thinking' first originated in the manufacturing industry as a means of improving productivity whilst maintaining quality through eliminating wasteful processes. The purpose of this article is to demonstrate how the principles of 'lean thinking' are relevant to healthcare and the operating theatre, with reference to our own institutional experience.

A Web-Based Lean Simulation Game for Office Operations: Training the Other Side of a Lean Enterprise

ERIC Educational Resources Information Center

Kuriger, Glenn W.; Wan, Huang-da; Mirehei, S. Moussa; Tamma, Saumya; Chen, F. Frank

2010-01-01

This research proposes a Web-based version of a lean office simulation game (WeBLOG). The game is designed to be used to train lean concepts to office and administrative personnel. This group belongs to the frequently forgotten side of a lean enterprise. Over four phases, the game presents the following seven lean tools: one-piece flow,…

The Waukesha Turbocharger Control Module: A tool for improved engine efficiency and response

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

Zurlo, J.R.; Reinbold, E.O.; Mueller, J.

1996-12-31

The Waukesha Turbocharger Control Module allows optimum control of turbochargers on lean burn gaseous fueled engines. The Turbocharger Control Module is user programmed to provide either maximum engine efficiency or best engine response to load changes. In addition, the Turbocharger Control Module prevents undesirable turbocharger surge. The Turbocharger Control Module consists of an electronic control box, engine speed, intake manifold pressure, ambient temperature sensors, and electric actuators driving compressor bypass and wastegate valves. The Turbocharger Control Module expands the steady state operational environment of the Waukesha AT27GL natural gas engine from sea level to 1,525 m altitude with one turbochargermore » match and improves the engine speed turn down by 80 RPM. Finally, the Turbocharger Control Module improves engine response to load changes.« less

Implementing Lean Manufacturing in Malaysian Small and Medium Startup Pharmaceutical Company

NASA Astrophysics Data System (ADS)

Ibrahim, Wan Mohd Khairi bin Wan; Rahman, Mohamed Abdul; Abu Bakar, Mohd Rushdi bin

2017-03-01

Domestic pharmaceutical industry has been identified by the Malaysian government as an industry to be developed under its 11th economic development plan. Most homegrown pharmaceutical companies fall under the category of small and medium enterprises (SME) and therefore need to be highly efficient in their operations to compete with the multinationals. Though lean manufacturing is a well-known methodology to achieve an efficient operation, only a small percentage of the local SMEs implement it. The study aims to determine the real success factors in lean implementation through systematic review of relevant literature on lean manufacturing implementation in local companies, onsite observation of a selected SME company, Global Factor Sdn. Bhd. (GFSB), that successfully implemented lean manufacturing followed by actual implementation of lean project at IKOP Sdn. Bhd., a small startup pharmaceutical company. Lean tools like Gemba, value stream map (VSM) and spaghetti diagram were used to analyze and improve a process at IKOP Sdn. Bhd. The literature review showed that the implementation of lean manufacturing at Malaysian SMEs involved in pharmaceutical industry is at its infancy. Study at GFSB indicated that successful implementation of lean manufacturing stems from management support, employee’s commitment, government support and knowledge on lean among employees. Application of lean tools in IKOP Sdn. Bhd. to improve the process cycle efficiency of hand sanitizer, i-Hand 4.0, has shown that the GMP guidelines are not jeopardized. The Kaizen improvement project resulted in 46.3% reduction in lead time. It may be concluded that implementing lean manufacturing in any small local startup pharmaceutical company is beneficial in reducing operational costs and increasing the efficiency and effectiveness and does not conflict with the existing GMP guidelines.

Lean management in academic surgery.

PubMed

Collar, Ryan M; Shuman, Andrew G; Feiner, Sandra; McGonegal, Amy K; Heidel, Natalie; Duck, Mary; McLean, Scott A; Billi, John E; Healy, David W; Bradford, Carol R

2012-06-01

Lean is a management system designed to enhance productivity by eliminating waste. Surgical practice offers many opportunities for improving efficiency. Our objective was to determine whether systematic implementation of lean thinking in an academic otolaryngology operating room improves efficiency and profitability and preserves team morale and educational opportunities. In an 18-month prospective quasi-experimental study, a multidisciplinary task force systematically implemented lean thinking within an otolaryngology operating room of an academic health system. Operating room turnover time and turnaround time were measured during a baseline period; an observer-effect period in which workers were made aware that their efficiency was being measured but before implementing lean changes; and an intervention period after redesign principles had been used. The impact on teamwork, morale, and surgical resident education were measured during the baseline and intervention periods through validated surveys. A profit model was applied to estimate the financial implications of the study. There was no difference between the baseline and observer-effect periods of the study for turnover time (p = 0.98) or turnaround time (p = 0.20). During the intervention period, the mean turnover time and turnaround time were significantly shorter than during the baseline period (29 vs 38 minutes; p < 0.001 and 69 vs 89 minutes; p < 0.001, respectively). The composite morale score suggested improved morale after implementation (p = 0.011). Educational metrics were unchanged before and after implementation. The annual opportunity revenue for the involved operating room is $330,000; when extrapolated throughout the operating rooms, lean thinking could create 6,500 hours of capacity annually. Application of lean management techniques to a single operating room and surgical service improved operating room efficiency and morale, sustained resident education, and can provide considerable financial gains when scaled to an entire academic surgical suite. Copyright © 2012. Published by Elsevier Inc.

The Regional Special Operations Headquarters: Franchising the NATO Model as a Hedge in Lean Times

DTIC Science & Technology

2012-04-01

1 AIR FORCE FELLOWS AIR UNIVERSITY THE REGIONAL SPECIAL OPERATIONS HEADQUARTERS: FRANCHISING THE NATO MODEL AS A HEDGE IN LEAN...Headquarters: Franchising The NATO Model As A Hedge In Lean Times 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...it is not copyrighted, but is the property of the United States government. 3 The Regional Special Operations Headquarters: Franchising the

A Study on the Effect of Stratified Mixture Formation on Combustion Characteristics in a Constant Volume Combustion Chamber

NASA Astrophysics Data System (ADS)

Lee, Kihyung; Lee, Changhee; Jeoung, Haeyoung

It is well known that a lean burn engine caused by stratified mixture formation has many kinds of advantages to combustion characteristics, such as higher thermal efficiency and lower CO, NOx levels than conventional homogeneous mixture combustion. Although this combustion can achieve low fuel consumption, it produces much unburned hydrocarbon and soot because of inhomogeneity of the charge mixture in the combustion chamber. Therefore, it is necessary to investigate the effect of mixture formation on combustion characteristics in order to obtain the stable lean combustion. In this paper, fundamental studies for stratified combustion were carried out using a constant volume combustion chamber. The effect of mixture formation on the combustion characteristics in the chamber was examined experimentally. In addition, the effect of turbulence on stratified charge combustion process was observed by schlieren photography. From this study, as the swirl intensity increases, (Sv)max is rapidly enhanced and the period of combustion is shortened. We also find that the stratification degree can be quantified by using burning velocity and it was controlled by induced air pressure and turbulent intensity.

Kinetics of Hydrogen Oxidation Downstream of Lean Propane and Hydrogen Flames

NASA Technical Reports Server (NTRS)

Fine, Burton

1961-01-01

The decay of hydrogen was measured downstream of lean, flat, premixed hydrogen and propane-air flames seated on cooled porous burners. Experimental variables included temperature, pressure, initial equivalence ratio and diluent. Sampling of burned gas was done through uncooled quartz orifice probes, and the analysis was based on gas chromatography. An approximate treatment of the data in which diffusion was neglected led to the following rate expression for the zone downstream of hydrogen flames d[H (sub 2)] divided by (d times t) equals 1.7 times 10 (sup 10) [H (sub 2)] (sup 3) divided by (sub 2) [O (sub 2)]e (sup (-8100 divided by RT)) moles per liters per second. On the basis of a rate expression of this form, the specific rate constant for the reaction downstream of hydrogen flames was about three times as great as that determined downstream of propane flames. This result was explained on the basis of the existence of a steady state between hydrogen and carbon monoxide in the burned gas downstream of propane flames.

U.S. Department of Energy FreedomCar & Vehicle Technologies Program CARB Executive Order Exemption Process for a Hydrogen-fueled Internal Combustion engine Vehicle -- Status Report

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

Not Available

2008-04-01

The CARB Executive Order Exemption Process for a Hydrogen-fueled Internal Combustion Engine Vehicle was undertaken to define the requirements to achieve a California Air Resource Board Executive Order for a hydrogenfueled vehicle retrofit kit. A 2005 to 2006 General Motors Company Sierra/Chevrolet Silverado 1500HD pickup was assumed to be the build-from vehicle for the retrofit kit. The emissions demonstration was determined not to pose a significant hurdle due to the non-hydrocarbon-based fuel and lean-burn operation. However, significant work was determined to be necessary for Onboard Diagnostics Level II compliance. Therefore, it is recommended that an Experimental Permit be obtained frommore » the California Air Resource Board to license and operate the vehicles for the durability of the demonstration in support of preparing a fully compliant and certifiable package that can be submitted.« less

Atomization and Dispersion of a Liquid Jet Injected Into a Crossflow of Air

NASA Technical Reports Server (NTRS)

Seay, J. E.; Samuelson, G. S.

1996-01-01

In recent years, environmental regulations have become more stringent, requiring lower emissions of mainly nitrogen oxides (NOx), as well as carbon monoxide (CO) and unburned hydrocarbons (UHC). These regulations have forced the gas turbine industry to examine non-conventional combustion strategies, such as the lean burn approach. The reasoning behind operating under lean conditions is to maintain the temperature of combustion near and below temperatures required for the formation of thermal nitric oxide (NO). To be successful, however, the lean processes require careful preparation of the fuel/air mixture to preclude formation of either locally rich reaction zones, which may give rise to NO formation, or locally lean reaction zones, which may give rise to inefficient fuel processing. As a result fuel preparation is crucial to the development and success of new aeroengine combustor technologies. A key element of the fuel preparation process is the fuel nozzle. As nozzle technologies have developed, airblast atomization has been adopted for both industrial and aircraft gas turbine applications. However, the majority of the work to date has focused on prefilming nozzles, which despite their complexity and high cost have become an industry standard for conventional combustion strategies. It is likely that the new strategies required to meet future emissions goals will utilize novel fuel injector approaches, such as radial injection. This thesis proposes and demonstrates an experiment to examine, on a mechanistic level (i.e., the physics of the action), the processes associated with the atomization, evaporation, and dispersion of a liquid jet introduced, from a radial, plain-jet airblast injector, into a crossflow of air. This understanding requires the knowledge not only of what factors influence atomization, but also the underlying mechanism associated with liquid breakup and dispersion. The experimental data acquired identify conditions and geometries for improved performance of radial airblast injectors.

Analysis on using biomass lean syngas in micro gas turbines

NASA Astrophysics Data System (ADS)

Mărculescu, C.; Cenuşă, V. E.; Alexe, F. N.

2016-08-01

The paper presents an analysis on small systems for converting biomass/wastes into power using Micro Gas Turbines (MGT) fed with gaseous bio-fuels produced by air- gasification. The MGT is designed for burning various fossil liquid and gas fuels, having catalogue data related to natural gas use. Fuel switch changes their performances. The present work is focused on adapting the MGT for burning alternative low quality gas fuel produced by biomass air gasification. The heating values of these gas fuels are 3 to 5 times lower than the methane ones, leading to different air demand for the stoichiometric burning. Validated numerical computation procedures were used to model the MGT thermodynamic process. Our purpose was to analyze the influence of fuel change on thermodynamic cycle performances.

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.

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.

Biogas Laminar Burning Velocity and Flammability Characteristics in Spark Ignited Premix Combustion

NASA Astrophysics Data System (ADS)

Anggono, Willyanto; Wardana, I. N. G.; Lawes, M.; Hughes, K. J.; Wahyudi, Slamet; Hamidi, Nurkholis; Hayakawa, Akihiro

2013-04-01

Spherically expanding flames propagating at constant pressure were employed to determine the laminar burning velocity and flammability characteristics of biogas-air mixtures in premixed combustion to uncover the fundamental flame propagation characteristics of a new alternative and renewable fuel. The results are compared with those from a methane-air flame. Biogas is a sustainable and renewable fuel that is produced in digestion facilities. The composition of biogas discussed in this paper consists of 66.4% methane, 30.6% carbon dioxide and 3% nitrogen. Burning velocity was measured at various equivalence ratios (phi) using a photographic technique in a high pressure fan-stirred bomb, the initial condition being at room temperature and atmospheric pressure. The flame for methane-air mixtures propagates from phi=0.6 till phi=1.3. The flame at phi >= 1.4 does not propagate because the combustion reaction is quenched by the larger mass of fuel. At phi<=0.5, it does not propagate as well since the heat of reaction is insufficient to burn the mixtures. The flame for biogas-air mixtures propagates in a narrower range, that is from phi=0.6 to phi=1.2. Different from the methane flame, the biogas flame does not propagate at phi>=1.3 because the heat absorbed by inhibitors strengthens the quenching effect by the larger mass of fuel. As in the methane flame, the biogas flame at phi<=0.5 does not propagate. This shows that the effect of inhibitors in extremely lean mixtures is small. Compared to a methane-air mixture, the flammability characteristic (flammable region) of biogas becomes narrower in the presence of inhibitors (carbon dioxide and nitrogen) and the presence of inhibitors causes a reduction in the laminar burning velocity. The inhibitor gases work more effectively at rich mixtures because the rich biogas-air mixtures have a higher fraction of carbon dioxide and nitrogen components compared to the lean biogas-air mixtures.

Can U.S. Forces Lean from Mistakes Made by British during First and Second Anglo-Afghan Wars in the 19th Century?

DTIC Science & Technology

2011-04-29

INDIVIDUAL STUDENT AUTHOR AND DO NOT NECESSARILY REPRESENT THE VIEWS OF EITHER THE MARINE COPS COMMAND AND STAFF COLLEGE OR · ANY OTHER GOVERNMENTAL...entered Afghanistan in April1842. This army destroyed small towns, slaughtered livestock, burned crops and chased villagers into the countryside as

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

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

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

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

Using Dynamic Value Stream Mapping and Lean Accounting Box Scores to Support Lean Implementation

ERIC Educational Resources Information Center

Woehrle, Stephen L.; Abou-Shady, Louay

2010-01-01

Lean has proven to be an effective management philosophy for improving businesses in a competitive market by eliminating waste and improving operations. An impact of implementing lean projects is the rapid reduction in inventory levels, which gives management the false impression that profits are decreasing while workers on the shop floor observe…

Improving a Dental School's Clinic Operations Using Lean Process Improvement.

PubMed

Robinson, Fonda G; Cunningham, Larry L; Turner, Sharon P; Lindroth, John; Ray, Deborah; Khan, Talib; Yates, Audrey

2016-10-01

The term "lean production," also known as "Lean," describes a process of operations management pioneered at the Toyota Motor Company that contributed significantly to the success of the company. Although developed by Toyota, the Lean process has been implemented at many other organizations, including those in health care, and should be considered by dental schools in evaluating their clinical operations. Lean combines engineering principles with operations management and improvement tools to optimize business and operating processes. One of the core concepts is relentless elimination of waste (non-value-added components of a process). Another key concept is utilization of individuals closest to the actual work to analyze and improve the process. When the medical center of the University of Kentucky adopted the Lean process for improving clinical operations, members of the College of Dentistry trained in the process applied the techniques to improve inefficient operations at the Walk-In Dental Clinic. The purpose of this project was to reduce patients' average in-the-door-to-out-the-door time from over four hours to three hours within 90 days. Achievement of this goal was realized by streamlining patient flow and strategically relocating key phases of the process. This initiative resulted in patient benefits such as shortening average in-the-door-to-out-the-door time by over an hour, improving satisfaction by 21%, and reducing negative comments by 24%, as well as providing opportunity to implement the electronic health record, improving teamwork, and enhancing educational experiences for students. These benefits were achieved while maintaining high-quality patient care with zero adverse outcomes during and two years following the process improvement project.

Installation and testing of a cummins Qsk19 lean burn natural gas engine

NASA Astrophysics Data System (ADS)

Sutley, Franklin H.

The goal for a more efficient engine will never disappear. Over the years many different techniques have been explored within the common goal of higher efficiency. Lean combustion has proven to be effective at increasing efficiencies as well as reducing emissions. The purpose of this thesis is to install a modern Cummins QSK19G and perform certain test that will explore the lean combustion limits and other methods that could possibly increase efficiency even more. The entire installation and instrumentation process is documented within this thesis. The engine was installed in the Engines and Energy Conversion Laboratory at Colorado State University. The engine was installed with the hopes of instilling the desire for endless future tests from Cummins as well as other companies seeking this type of research engine. The lean limit was explored in the most detail. Cummins supplied a test plan that satisfied their desired stopping at a lean limit when the coefficient of variance of indicated mean effective pressure reached 5%. For the curiosity of others involved and this thesis, the lean limit was explored further until the engine could no longer ignite the ultra-lean combustion mixture. Friction accounts for a significant loss in a modern internal combustion engine. One role of the engine oil is to reduce these frictional losses as much as possible without causing increased wear. A test was conducted on the QSK19G to explore the effects of varying the engine oil viscosity. Frictional losses of two different viscosity oils were compared to the stock engine oil losses. The fact that reducing oil viscosity reduces frictional losses was proven in the test.

Environmental Professional’s Guide to Lean and Six Sigma: Executive Summary

EPA Pesticide Factsheets

Introduction to the guide that describes how Lean and Six Sigma relate to the environment and provides guidance on how environmental professionals can connect with Lean and Six Sigma activities to generate better environmental and operational results.

Diesel fuel burner for diesel emissions control system

DOEpatents

Webb, Cynthia C.; Mathis, Jeffrey A.

2006-04-25

A burner for use in the emissions system of a lean burn internal combustion engine. The burner has a special burner head that enhances atomization of the burner fuel. Its combustion chamber is designed to be submersed in the engine exhaust line so that engine exhaust flows over the outer surface of the combustion chamber, thereby providing efficient heat transfer.

The Effect of Air Preheat at Atmospheric Pressure on the Formation of NO(x) in the Quick-Mix Sections of an Axially Staged Combustor

NASA Technical Reports Server (NTRS)

Vardakas, M. A.; Leong, M. Y.; Brouwer, J.; Samuelsen, G. S.; Holdeman, J. D.

1999-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of nitrogen oxides (NO(x)) in gas turbine systems. The success of this combustor strategy is dependent upon the efficiency of the mixing section bridging the fuel-rich and fuel-lean stages. Note that although these results were obtained from an experiment designed to study an RQL mixer, the link between mixing and NOx signatures is considerably broader than this application, in that the need to understand this link exists in most advanced combustors. The experiment reported herein was designed to study the effects of inlet air temperature on NO(x) formation in a mixing section. The results indicate that NO(x) emission is increased for all preheated cases compared to non-preheated cases. When comparing the various mixing modules, the affect of jet penetration is important, as this determines where NO(x) concentrations peak, and affects overall NO(x) production. Although jet air comprises 70 percent of the total airflow, the impact that jet air preheat has on overall NO(x) emissions is small compared to preheating both main and jet air flow.

Imaging of Combustion Species in a Radially-Staged Gas Turbine Combustor

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.; Ockunzzi, Kelly A.; Schock, Harold J.

1996-01-01

Plannar laser-induced fluorescence (PLIF) is used to characterize the complex flowfield of a unique fuel-lean, radially-staged high pressure gas turbine combustor. PLIF images of OH are presented for two fuel injector configurations. PLIF images of NO, the first acquired at these conditions, are presented and compared with gas sample extraction probe measurements. Flow field imaging of nascent C2 chemiluminescence is also investigated. An examination is made of the interaction between adjoining lean premixed prevaporized (LPP) injectors. Fluorescence interferences at conditions approaching 2000 K and 15 atm are observed and attributed to polycyclic aromatic hydrocarbon (PAH) emissions. All images are acquired at a position immediately downstream of the fuel injectors with combustor burning JP-5 fuel.

Imaging of Combustion Species in a Radially-Staged Gas Turbine Combustor

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.; Ockunzzi, Kelly A.; Schock, Harold J.

1996-01-01

Planar laser-induced fluorescence (PLIF) is used to characterize the complex flowfield of a unique fuel-lean, radially-staged, high pressure gas turbine combustor. PLIF images of OH are presented for two fuel injector configurations. PLIF images of NO, the first acquired at these conditions, are presented and compared with gas sample extraction probe measurements. Flow field imaging of nascent C2 chemiluminescence is also investigated. An examination is made of the interaction between adjoining lean premixed prevaporized (LPP) injectors. Fluorescence interferences at conditions approaching 2000 K and 15 atm are observed and attributed to polycyclic aromatic hydrocarbon (PAH) emissions. All images are acquired at a position immediately downstream of the fuel injectors with the combustor burning JP-5 fuel.

Experimental evaluation of combustor concepts for burning broad property fuels

NASA Technical Reports Server (NTRS)

Kasper, J. M.; Ekstedt, E. E.; Dodds, W. J.; Shayeson, M. W.

1980-01-01

A baseline CF6-50 combustor and three advanced combustor designs were evaluated to determine the effects of combustor design on operational characteristics using broad property fuels. Three fuels were used in each test: Jet A, a broad property 13% hydrogen fuel, and a 12% hydrogen fuel blend. Testing was performed in a sector rig at true cruise and simulated takeoff conditions for the CF6-50 engine cycle. The advanced combustors (all double annular, lean dome designs) generally exhibited lower metal temperatures, exhaust emissions, and carbon buildup than the baseline CF6-50 combustor. The sensitivities of emissions and metal temperatures to fuel hydrogen content were also generally lower for the advanced designs. The most promising advanced design used premixing tubes in the main stage. This design was chosen for additional testing in which fuel/air ratio, reference velocity, and fuel flow split were varied.

Active Combustion Control for Aircraft Gas Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Breisacher, Kevin J.; Saus, Joseph R.; Paxson, Daniel E.

2000-01-01

Lean-burning combustors are susceptible to combustion instabilities. Additionally, due to non-uniformities in the fuel-air mixing and in the combustion process, there typically exist hot areas in the combustor exit plane. These hot areas limit the operating temperature at the turbine inlet and thus constrain performance and efficiency. Finally, it is necessary to optimize the fuel-air ratio and flame temperature throughout the combustor to minimize the production of pollutants. In recent years, there has been considerable activity addressing Active Combustion Control. NASA Glenn Research Center's Active Combustion Control Technology effort aims to demonstrate active control in a realistic environment relevant to aircraft engines. Analysis and experiments are tied to aircraft gas turbine combustors. Considerable progress has been shown in demonstrating technologies for Combustion Instability Control, Pattern Factor Control, and Emissions Minimizing Control. Future plans are to advance the maturity of active combustion control technology to eventual demonstration in an engine environment.

Direct fired reciprocating engine and bottoming high temperature fuel cell hybrid

DOEpatents

Geisbrecht, Rodney A [New Alexandria, PA; Holcombe, Norman T [McMurray, PA

2006-02-07

A system of a fuel cell bottoming an internal combustion engine. The engine exhaust gas may be combined in varying degrees with air and fed as input to a fuel cell. Reformer and oxidizers may be combined with heat exchangers to accommodate rich and lean burn conditions in the engine in peaking and base load conditions without producing high concentrations of harmful emissions.

Simultaneous measurement of the surface temperature and the release of atomic sodium from a burning black liquor droplet

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

Saw, Woei L.; Nathan, Graham J.; School of Mechanical Engineering, The University of Adelaide

2010-04-15

Simultaneous measurement of the concentration of released atomic sodium, swelling, surface and internal temperature of a burning black liquor droplet under a fuel lean and rich condition has been demonstrated. Two-dimensional two-colour optical pyrometry was employed to determine the distribution of surface temperature and swelling of a burning black liquor droplet while planar laser-induced fluorescence (PLIF) was used to assess the temporal release of atomic sodium. The key findings of these studies are: (i) the concentration of atomic sodium released during the drying and devolatilisation stages was found to be correlated with the external surface area; and (ii) the insignificantmore » presence of atomic sodium during the char consumption stage shows that sodium release is suppressed by the lower temperature and by the high CO{sub 2} content in and around the particle. (author)« less

Intelligent Engine Systems: Alternate Fuels Evaluation

NASA Technical Reports Server (NTRS)

Ballal, Dilip

2008-01-01

The performance and gaseous emissions were measured for a well-stirred reactor operating under lean conditions for two fuels: JP8 and a synthetic Fisher-Tropsch fuel over a range of equivalence ratios from 0.6 down to the lean blowout. The lean blowout characteristics were determined in LBO experiments at loading parameter values from 0.7 to 1.4. The lean blowout characteristics were then explored under higher loading conditions by simulating higher altitude operation with the use of nitrogen as a dilution gas for the air stream. The experiments showed that: (1) The lean blowout characteristics for the two fuels were close under both low loading and high loading conditions. (2) The combustion temperatures and observed combustion efficiencies were similar for the two fuels. (3) The gaseous emissions were similar for the two fuels and the differences in the H2O and CO2 emissions appear to be directly relatable to the C/H ratio for the fuels.

Effect of reductive treatments on Pt behavior and NOx storage in lean NOx trap catalysts

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

Wang, Xianqin; Kim, Do Heui; Kwak, Ja Hun

2011-10-01

Lean NOx trap (LNT) catalysts represent a promising approach to meet increasingly stringent NOx emission regulations on diesel and other lean-burn engines. Pt material properties, including dispersion and particle size, are known to be important factors in determining NOx uptake performance, since Pt provides active sites for NO oxidation to NO2 necessary for storing NOx as nitrates, and for the reduction of nitrates to N2. In this work, the physicochemical properties of Pt in Pt-BaO/Al2O3 LNT catalysts, such as the Pt accessible surface area and particle size, were investigated by using various tools, such as irreversible volumetric H2 chemisorption, highmore » resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD), following successive reductive treatments at elevated temperatures. NOx uptake activities were also measured to establish a relationship between the properties of Pt and NOx storage following identical high-temperature reductive treatments. We find that the reductive treatments of Pt-BaO/Al2O3 lean NOx trap catalysts at temperatures up to 500 ºC promote a significant increase in NOx uptake explained, in part, by an induced close interaction between Pt and BaO phases in the catalyst, thus enabling facilitation of the NOx storage process.« less

Simulation Modeling of a Facility Layout in Operations Management Classes

ERIC Educational Resources Information Center

Yazici, Hulya Julie

2006-01-01

Teaching quantitative courses can be challenging. Similarly, layout modeling and lean production concepts can be difficult to grasp in an introductory OM (operations management) class. This article describes a simulation model developed in PROMODEL to facilitate the learning of layout modeling and lean manufacturing. Simulation allows for the…

Rapid starting methanol reactor system

DOEpatents

Chludzinski, Paul J.; Dantowitz, Philip; McElroy, James F.

1984-01-01

The invention relates to a methanol-to-hydrogen cracking reactor for use with a fuel cell vehicular power plant. The system is particularly designed for rapid start-up of the catalytic methanol cracking reactor after an extended shut-down period, i.e., after the vehicular fuel cell power plant has been inoperative overnight. Rapid system start-up is accomplished by a combination of direct and indirect heating of the cracking catalyst. Initially, liquid methanol is burned with a stoichiometric or slightly lean air mixture in the combustion chamber of the reactor assembly. The hot combustion gas travels down a flue gas chamber in heat exchange relationship with the catalytic cracking chamber transferring heat across the catalyst chamber wall to heat the catalyst indirectly. The combustion gas is then diverted back through the catalyst bed to heat the catalyst pellets directly. When the cracking reactor temperature reaches operating temperature, methanol combustion is stopped and a hot gas valve is switched to route the flue gas overboard, with methanol being fed directly to the catalytic cracking reactor. Thereafter, the burner operates on excess hydrogen from the fuel cells.

Randomized Controlled Trial to Determine the Efficacy of Long-Term Growth Hormone Treatment in Severely Burned Children

PubMed Central

Branski, Ludwik K.; Herndon, David N.; Barrow, Robert E.; Kulp, Gabriela A.; Klein, Gordon L.; Suman, Oscar E.; Przkora, Rene; Meyer, Walter; Huang, Ted; Lee, Jong O.; Chinkes, David L.; Mlcak, Ronald P.; Jeschke, Marc G.

2014-01-01

Background Recovery from a massive burn is characterized by catabolic and hypermetabolic responses that persist up to 2 years and impair rehabilitation and reintegration. The objective of this study was to determine the effects of long-term treatment with recombinant human growth hormone (rhGH) on growth, hypermetabolism, body composition, bone metabolism, cardiac work, and scarring in a large prospective randomized single-center controlled clinical trial in pediatric patients with massive burns. Patients and Methods A total of 205 pediatric patients with massive burns over 40% total body surface area were prospectively enrolled between 1998 and 2007 (clinicaltrials.gov ID NCT00675714). Patients were randomized to receive either placebo (n = 94) or long-term rhGH at 0.05, 0.1, or 0.2 mg/kg/d (n = 101). Changes in weight, body composition, bone metabolism, cardiac output, resting energy expenditure, hormones, and scar development were measured at patient discharge and at 6, 9, 12, 18, and 24 months postburn. Statistical analysis used Tukey t test or ANOVA followed by Bonferroni correction. Significance was accepted at P < 0.05. Results RhGH administration markedly improved growth and lean body mass, whereas hypermetabolism was significantly attenuated. Serum growth hormone, insulin-like growth factor-I, and IGFBP-3 was significantly increased, whereas percent body fat content significantly decreased when compared with placebo, P < 0.05. A subset analysis revealed most lean body mass gain in the 0.2 mg/kg group, P < 0.05. Bone mineral content showed an unexpected decrease in the 0.2 mg/kg group, along with a decrease in PTH and increase in osteocalcin levels, P < 0.05. Resting energy expenditure improved with rhGH administration, most markedly in the 0.1 mg/kg/d rhGH group, P < 0.05. Cardiac output was decreased at 12 and 18 months postburn in the rhGH group. Long-term administration of 0.1 and 0.2 mg/kg/d rhGH significantly improved scarring at 12 months postburn, P < 0.05. Conclusion This large prospective clinical trial showed that long-term treatment with rhGH effectively enhances recovery of severely burned pediatric patients. PMID:19734776

Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

NASA Astrophysics Data System (ADS)

Zhou, Zhen; Hernández-Pérez, Francisco E.; Shoshin, Yuriy; van Oijen, Jeroen A.; de Goey, Laurentius P. H.

2017-09-01

The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

Scaling Lean in primary care: impacts on system performance.

PubMed

Hung, Dorothy Y; Harrison, Michael I; Martinez, Meghan C; Luft, Harold S

2017-03-01

We examined a wide range of performance outcomes after Lean methodology-a leading strategy to enhance efficiency and patient value-was implemented and scaled across all primary care clinics in a nonprofit, ambulatory care delivery system. Using a stepped wedge approach, we assessed changes associated with the phased introduction of Lean-based redesigns across 46 primary care departments in 17 different clinic locations. Longitudinal analysis of operational metrics included: workflow efficiency, physician productivity, operating expenses, clinical quality, and satisfaction among patients, physicians, and staff. We used interrupted time series analysis with generalized linear mixed models to estimate Lean impacts over time. Projected outcomes in the absence of changes (ie, counterfactuals) were compared with observed outcomes after Lean redesigns were implemented, and mean differences were assessed using 95% bias-corrected bootstrap confidence intervals (CIs). We observed systemwide improvements in workflow efficiencies (eg, 95% CI, 5.8-10.4) and physician productivity (95% CI, 3.9-27.2), with no adverse effects on clinical quality. Patient satisfaction increased with respect to access to care (95% CI, 15.2-20.7), handling of personal issues (95% CI, 2.1-6.9), and overall experience of care (95% CI, 11.0-17.0), but decreased with respect to interactions with care providers (95% CI, -13.4 to -5.7). Departmental operating costs decreased, and annual staff and physician satisfaction scores increased particularly among early adopters, with key improvements in employee engagement, connection to purpose, relationships with staff, and physician time spent working. Lean redesigns can benefit primary care patients, physicians, and staff without negatively impacting the quality of clinical care. Study results may lead other delivery system leaders to innovate using Lean techniques and may further enhance support for Lean learning among public and private payers.

Addressing the medicinal chemistry bottleneck: a lean approach to centralized purification.

PubMed

Weller, Harold N; Nirschl, David S; Paulson, James L; Hoffman, Steven L; Bullock, William H

2012-09-10

The use of standardized lean manufacturing principles to improve drug discovery productivity is often thought to be at odds with fostering innovation. This manuscript describes how selective implementation of a lean optimized process, in this case centralized purification for medicinal chemistry, can improve operational productivity and increase scientist time available for innovation. A description of the centralized purification process is provided along with both operational and impact (productivity) metrics, which indicate lower cost, higher output, and presumably more free time for innovation as a result of the process changes described.

Removal of oxides of nitrogen from gases in multi-stage coal combustion

DOEpatents

Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

1998-01-13

Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

Removal of oxides of nitrogen from gases in multi-stage coal combustion

DOEpatents

Mollot, Darren J.; Bonk, Donald L.; Dowdy, Thomas E.

1998-01-01

Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

The Influence of Lean on K-12 District Management: A Case Study

ERIC Educational Resources Information Center

Brown, Beverly

2011-01-01

For decades, policymakers and educators have focused on public school equity and adequacy, while paying little attention to efficiency. This qualitative single case study was designed to capture explicit information about Lean management, operations, and culture in a K-12 Michigan school district engaged in Lean training and implementation for a…

Hybrid Automotive Engine Using Ethanol-Burning Miller Cycle

NASA Technical Reports Server (NTRS)

Weinstein, Leonard

2004-01-01

A proposed hybrid (internal-combustion/ electric) automotive engine system would include as its internal-combustion subsystem, a modified Miller-cycle engine with regenerative air preheating and with autoignition like that of a Diesel engine. The fuel would be ethanol and would be burned lean to ensure complete combustion. Although the proposed engine would have a relatively low power-to-weight ratio compared to most present engines, this would not be the problem encountered if this engine were used in a non-hybrid system since hybrid systems require significantly lower power and thus smaller engines than purely internal-combustion-engine-driven vehicles. The disadvantage would be offset by the advantages of high fuel efficiency, low emission of nitrogen oxides and particulate pollutants, and the fact that ethanol is a renewable fuel. The original Miller-cycle engine, named after its inventor, was patented in the 1940s and is the basis of engines used in some modern automobiles, but is not widely known. In somewhat oversimplified terms, the main difference between a Miller-cycle engine and a common (Otto-cycle) automobile engine is that the Miller-cycle engine has a longer expansion stroke while retaining the shorter compression stroke. This is accomplished by leaving the intake valve open for part of the compression stroke, whereas in the Otto cycle engine, the intake valve is kept closed during the entire compression stroke. This greater expansion ratio makes it possible to extract more energy from the combustion process without expending more energy for compression. The net result is greater efficiency. In the proposed engine, the regenerative preheating would be effected by running the intake air through a heat exchanger connected to the engine block. The regenerative preheating would offer two advantages: It would ensure reliable autoignition during operation at low ambient temperature and would help to cool the engine, thereby reducing the remainder of the power needed for cooling and thereby further contributing to efficiency. An electrical resistance air preheater might be needed to ensure autoignition at startup and during a short warmup period. Because of the autoignition, the engine could operate without either spark plugs or glow plugs. Ethanol burns relatively cleanly and has been used as a motor fuel since the invention of internal-combustion engines. However, the energy content of ethanol per unit weight of ethanol is less than that of Diesel fuel or gasoline, and ethanol has a higher heat of vaporization. Because the Miller cycle offers an efficiency close to that of the Diesel cycle, burning ethanol in a Miller-cycle engine gives about as much usable output energy per unit volume of fuel as does burning gasoline in a conventional gasoline automotive engine. Because of the combination of preheating, running lean, and the use of ethyl alcohol, the proposed engine would generate less power per unit volume than does a conventional automotive gasoline engine. Consequently, for a given power level, the main body of the proposed engine would be bulkier. However, because little or no exhaust cleanup would be needed, the increase in bulk of the engine could be partially offset by the decrease in bulk of the exhaust system. The regenerative preheating also greatly reduces the external engine cooling requirement, and would translate to reduced engine bulk. It may even be possible to accomplish the remaining cooling of the engine by use of air only, eliminating the bulk and power consumption of a water cooling system. The combination of a Miller-cycle engine with regenerative air preheating, ethyl alcohol fuel, and hybrid operation could result in an automotive engine system that satisfies the need for a low pollution, high efficiency, and simple engine with a totally renewable fuel.

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

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

Nigel Clark; Gregory Thompson; Richard Atkinson

Selective NOx Recirculation (SNR) involves cooling the engine exhaust gas and then adsorbing the oxides of nitrogen (NOx) from the exhaust stream, followed by the periodic desorption of NOx. By returning the desorbed, concentrated NOx into the engine intake and through the combustion chamber, a percentage of the NOx is decomposed during the combustion process. An initial study of NOx decomposition during lean-burn combustion was concluded in 2004 using a 1993 Cummins L10G 240hp natural gas engine. It was observed that the air/fuel ratio, injected NO (nitric oxide) quantity and engine operating points affected NOx decomposition rates of the engine.more » Chemical kinetic modeling results were also used to determine optimum NOx decomposition operating points and were published in the 2004 annual report. A NOx decomposition rate of 27% was measured from this engine under lean-burn conditions while the software model predicted between 35-42% NOx decomposition for similar conditions. A later technology 1998 Cummins L10G 280hp natural gas engine was procured with the assistance of Cummins Inc. to replace the previous engine used for 2005 experimental research. The new engine was equipped with an electronic fuel management system with closed-loop control that provided a more stable air/fuel ratio control and improved the repeatability of the tests. The engine was instrumented with an in-cylinder pressure measurement system and electronic controls, and was adapted to operate over a range of air/fuel ratios. The engine was connected to a newly commissioned 300hp alternating current (AC) motoring dynamometer. The second experimental campaign was performed to acquire both stoichiometric and slightly rich (0.97 lambda ratio) burn NOx decomposition rates. Effects of engine load and speed on decomposition were quantified, but Exhaust Gas Recirculation (EGR) was not varied independently. Decomposition rates of up to 92% were demonstrated. Following recommendations at the 2004 ARES peer review meeting at Argonne National Laboratories, in-cylinder pressure was measured to calculate engine indicated mean effective pressure (IMEP) changes due to NOx injections and EGR variations, and to observe conditions in the cylinder. The third experimental campaign gathered NOx decomposition data at 800, 1200 and 1800 rpm. EGR was added via an external loop, with EGR ranging from zero to the point of misfire. The air/fuel ratio was set at both stoichiometric and slightly rich conditions, and NOx decomposition rates were calculated for each set of runs. Modifications were made to the engine exhaust manifold to record individual exhaust temperatures. The three experimental campaigns have provided the data needed for a comprehensive model of NOx decomposition during the combustion process, and data have confirmed that there was no significant impact of injected NO on in-cylinder pressure. The NOx adsorption system provided by Sorbent Technologies Corp. (Twinsburg, OH), comprised a NOx adsorber, heat exchanger and a demister. These components were connected to the engine, and data were gathered to show both the adsorption of NOx from the engine, and desorption of NOx from the carbon-based sorbent material back into the engine intake, using a heated air stream. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a bench top adsorption system was constructed and instrumented with thermocouples and the system output was fed into a NOx analyzer. The temperature of this apparatus was controlled while gathering data on the characteristics of the sorbent material. These data were required for development of a system model. Preliminary data were gathered in 2005, and will continue in early 2006. To assess the economic benefits of the proposed SNR technology the WVU research team has been joined in the last quarter by Dr Richard Turton (WVU-Chemical Engineering), who is modeling, sizing and costing the major components. The tasks will address modeling and preliminary design of the heat exchanger, demister and NOx sorbent chamber suitable for a given engine. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passes over fresh sorbent material. This aspect of the research will continue into 2006, and the benefits and challenges of SNR will be compared with those of competing systems, such as Selective Catalytic Reduction. Chemical kinetic modeling using the CHEMKIN software package was extended in 2005 to the case of slightly rich burn with EGR. Simulations were performed at 10%, 20%, 30% and 40% of the intake air replaced with EGR. NOx decomposition efficiency was calculated at the point in time where 98% of fuel was consumed, which is believed to be a conservative approach. The modeling data show that reductions of over 70% are possible using the ''98% fuel burned'' assumption.« less

THE EFFECT OF SULFUR ON METHANE PARTIAL OXIDATION AND REFORMING PROCESSES FOR LEAN NOX TRAP CATALYSIS

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

Parks, II, James E; Ponnusamy, Senthil

2006-01-01

Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping after NOx purge. Creating the rich exhaust conditions for regeneration can be accomplished by catalytic partial oxidation of methane in the exhaust system. Furthermore, catalytic reforming of partial oxidation exhaust can enablemore » increased quantities of H2 which is an excellent reductant for lean NOx trap regeneration. It is critical to maintain clean and efficient partial oxidation and reforming processes to keep the lean NOx trap functioning properly and to reduce extra fuel consumption from the regeneration process. Although most exhaust constituents do not impede partial oxidation and reforming, some exhaust constituents may negatively affect the catalysts and result in loss of catalytic efficiency. Of particular concern are common catalyst poisons sulfur, zinc, and phosphorous. These poisons form in the exhaust through combustion of fuel and oil, and although they are present at low concentrations, they can accumulate to significant levels over the life of an engine system. In the work presented here, the effects of sulfur on the partial oxidation and reforming catalytic processes were studied to determine any durability limitations on the production of reductants for lean NOx trap catalyst regeneration.« less

Comparing Textbook Coverage of Lean Management to Academic Research and Industry Practitioner Perceptions

ERIC Educational Resources Information Center

Marley, Kathryn A.; Stodnick, T. Michael; Heyl, Jeff

2013-01-01

Within operations management courses, most instructors choose to devote classroom time to teaching the topic of lean management. However, because the amount of time available for instructors to devote to this topic varies considerably, there is a great deal of latitude on which specific lean tools and techniques should be discussed. The authors…

Active Control of Combustor Instability Shown to Help Lower Emissions

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Chang, Clarence T.

2002-01-01

In a quest to reduce the environmental impact of aerospace propulsion systems, extensive research is being done in the development of lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle. However, these lean-burning combustors have an increased susceptibility to thermoacoustic instabilities, or high-pressure oscillations much like sound waves, that can cause severe high-frequency vibrations in the combustor. These pressure waves can fatigue the combustor components and even the downstream turbine blades. This can significantly decrease the safe operating life of the combustor and turbine. Thus, suppression of the thermoacoustic combustor instabilities is an enabling technology for lean, low-emissions combustors. Under the Aerospace Propulsion and Power Base Research and Technology Program, the NASA Glenn Research Center, in partnership with Pratt & Whitney and United Technologies Research Center, is developing technologies for the active control of combustion instabilities. With active combustion control, the fuel is pulsed to put pressure oscillations into the system. This cancels out the pressure oscillations being produced by the instabilities. Thus, the engine can have lower pollutant emissions and long life.The use of active combustion instability control to reduce thermo-acoustic-driven combustor pressure oscillations was demonstrated on a single-nozzle combustor rig at United Technologies. This rig has many of the complexities of a real engine combustor (i.e., an actual fuel nozzle and swirler, dilution cooling, etc.). Control was demonstrated through modeling, developing, and testing a fuel-delivery system able to the 280-Hz instability frequency. The preceding figure shows the capability of this system to provide high-frequency fuel modulations. Because of the high-shear contrarotating airflow in the fuel injector, there was some concern that the fuel pulses would be attenuated to the point where they would not be effective for control. Testing in the combustor rig showed that open-loop pulsing of the fuel was, in fact, able to effectively modulate the combustor pressure. To suppress the combustor pressure oscillations due to thermoacoustic instabilities, it is desirable to time the injection of the fuel so that it interferes with the instability. A closed-loop control scheme was developed that uses combustion pressure feedback and a phase-shifting controller to time the fuel-injection pulses. Some suppression of the pressure oscillations at the 280-Hz instability frequency was demonstrated (see the next figure). However, the overall peak-to- peak pressure oscillations in the combustor were only mildly reduced. Improvements to control hardware and control methods are being continued to gain improved closed-loop reduction of the pressure oscillations.pulse the fuel at

The Effect of Special Operations Training on Testosterone, Lean Body Mass, and Strength and the Potential for Therapeutic Testosterone Replacement: A Review of the Literature

DTIC Science & Technology

2016-07-01

Effects of Testosterone or Anabolic Androgenic Steroid on Body Mass, Lean Body Mass, and Strength in Patients with Disease or Muscle Wasting...of Ranger training reportedly decreased body mass, fat mass, and lean body mass (LBM), with reductions in field measures of strength and power of...Table 3. Effects of Testosterone or Anabolic Androgenic Steroid with Resistance Training on Lean Body Mass and Strength Source Subjects Treatment

The Role of Lean Process Improvement in Implementation of Evidence-Based Practices in Behavioral Health Care.

PubMed

Steinfeld, Bradley; Scott, Jennifer; Vilander, Gavin; Marx, Larry; Quirk, Michael; Lindberg, Julie; Koerner, Kelly

2015-10-01

To effectively implement evidence-based practices (EBP) in behavioral health care, an organization needs to have operating structures and processes that can address core EBP implementation factors and stages. Lean, a widely used quality improvement process, can potentially address the factors crucial to successful implementation of EBP. This article provides an overview of Lean and the relationship between Lean process improvement steps, and EBP implementation models. Examples of how Lean process improvement methodologies can be used to help plan and carry out implementation of EBP in mental health delivery systems are presented along with limitations and recommendations for future research and clinical application.

Stripping ethanol from ethanol-blended fuels for use in NO.sub.x SCR

DOEpatents

Kass, Michael Delos [Oak Ridge, TN; Graves, Ronald Lee [Knoxville, TN; Storey, John Morse Elliot [Oak Ridge, TN; Lewis, Sr., Samuel Arthur; Sluder, Charles Scott [Knoxville, TN; Thomas, John Foster [Powell, TN

2007-08-21

A method to use diesel fuel alchohol micro emulsions (E-diesel) to provide a source of reductant to lower NO.sub.x emissions using selective catalytic reduction. Ethanol is stripped from the micro emulsion and entered into the exhaust gasses upstream of the reducing catalyst. The method allows diesel (and other lean-burn) engines to meet new, lower emission standards without having to carry separate fuel and reductant tanks.

Emissions performance of abatement technologies over the proposed EEC extra-urban driving cycle

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

VanBeckhoven, L.C.; Rijkeboer, R.C.

1989-01-01

The definition of what is likely to be the new EEC extra-urban cycle has made it possible to determine the emission characteristics of cars fitted with different emissions control equipment. Central to the evaluation program were three versions of experimental lean and dilute burn engines compared with engine modifications and open and closed loop three-way catalyst systems. This paper describes the evaluation program and evaluates its results.

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications

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

Parks, II, James E; Storey, John Morse; Theiss, Timothy J

Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance ismore » straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation, reformer, and lean NOx trap catalysts. The initial work on NOx reduction efficiency demonstrated that NOx emissions <0.1 g/bhp-hr (the ARES goal) can be achieved with the lean NOx trap catalyst technology. Subsequent work focused on cost and size optimization and durability issues which addressed two specific ARES areas of interest to industry ('Cost of Power' and 'Availability, Reliability, and Maintainability', respectively). Thus, the research addressed the approach of the lean NOx trap catalyst technology toward the ARES goals as shown in Table 1-1.« less

Lean manufacturing comes to China: a case study of its impact on workplace health and safety.

PubMed

Brown, Garrett D; O'Rourke, Dara

2007-01-01

Lean manufacturing, which establishes small production "cells," or teams of workers, who complete an entire product from raw material processing through final assembly and shipment, increases health and safety hazards by mixing previously separated exposures to various chemicals (with possible additive and cumulative effects) and noise. The intensification of work leads to greater ergonomic and stress-related adverse health effects, as well as increased safety hazards. The standard industrial hygiene approach of anticipation, recognition, evaluation, and hazard control is applicable to lean operations. A focus on worker participation in identifying and solving problems is critical for reducing negative impacts. A key to worker safety in lean production operations is the development of informed, empowered, and active workers with the knowledge, skills, and opportunity to act in the workplace to eliminate or reduce hazards.

Quality initiatives: lean approach to improving performance and efficiency in a radiology department.

PubMed

Kruskal, Jonathan B; Reedy, Allen; Pascal, Laurie; Rosen, Max P; Boiselle, Phillip M

2012-01-01

Many hospital radiology departments are adopting "lean" methods developed in automobile manufacturing to improve operational efficiency, eliminate waste, and optimize the value of their services. The lean approach, which emphasizes process analysis, has particular relevance to radiology departments, which depend on a smooth flow of patients and uninterrupted equipment function for efficient operation. However, the application of lean methods to isolated problems is not likely to improve overall efficiency or to produce a sustained improvement. Instead, the authors recommend a gradual but continuous and comprehensive "lean transformation" of work philosophy and workplace culture. Fundamental principles that must consistently be put into action to achieve such a transformation include equal involvement of and equal respect for all staff members, elimination of waste, standardization of work processes, improvement of flow in all processes, use of visual cues to communicate and inform, and use of specific tools to perform targeted data collection and analysis and to implement and guide change. Many categories of lean tools are available to facilitate these tasks: value stream mapping for visualizing the current state of a process and identifying activities that add no value; root cause analysis for determining the fundamental cause of a problem; team charters for planning, guiding, and communicating about change in a specific process; management dashboards for monitoring real-time developments; and a balanced scorecard for strategic oversight and planning in the areas of finance, customer service, internal operations, and staff development. © RSNA, 2012.

Adoption of Lean Principles in a High-Volume Molecular Diagnostic Microbiology Laboratory

PubMed Central

Mitchell, P. Shawn; Mandrekar, Jayawant N.

2014-01-01

Clinical laboratories are constantly facing challenges to do more with less, enhance quality, improve test turnaround time, and reduce operational expenses. Experience with adopting and applying lean concepts and tools used extensively in the manufacturing industry is described for a high-volume clinical molecular microbiology laboratory, illustrating how operational success and benefits can be achieved. PMID:24829247

Lean Blow-out Studies in a Swirl Stabilized Annular Gas Turbine Combustor

NASA Astrophysics Data System (ADS)

Mishra, R. K.; Kishore Kumar, S.; Chandel, Sunil

2015-05-01

Lean blow out characteristics in a swirl stabilized aero gas turbine combustor have been studied using computational fluid dynamics. For CFD analysis, a 22.5° sector of an annular combustor is modeled using unstructured tetrahedral meshes comprising 1.2 × 106 elements. The governing equations are solved using the eddy dissipation combustion model in CFX. The primary combustion zone is analyzed by considering it as a well stirred reactor. The analysis has been carried out for different operating conditions of the reactants entering into the control volume. The results are treated as the base-line or reference values. Combustion lean blow-out limits are further characterized studying the behavior of combustion zone during transient engine operation. The validity of the computational study has been established by experimental study on a full-scale annular combustor in an air flow test facility that is capable of simulating different conditions at combustor inlet. The experimental result is in a good agreement with the analytical predictions. Upon increasing the combustor mass flow, the lean blow out limit increases, i.e., the blow out occurs at higher fuel-air ratios. In addition, when the operating pressure decreases, the lean blow out limit increases, i.e., blow out occurs at higher fuel-air ratios.

Quality improvement in basic histotechnology: the lean approach.

PubMed

Clark, David

2016-01-01

Lean is a comprehensive system of management based on the Toyota production system (TPS), encompassing all the activities of an organization. It focuses management activity on creating value for the end-user by continuously improving operational effectiveness and removing waste. Lean management creates a culture of continuous quality improvement with a strong emphasis on developing the problem-solving capability of staff using the scientific method (Deming's Plan, Do, Check, Act cycle). Lean management systems have been adopted by a number of histopathology departments throughout the world to simultaneously improve quality (reducing errors and shortening turnround times) and lower costs (by increasing efficiency). This article describes the key concepts that make up a lean management system, and how these concepts have been adapted from manufacturing industry and applied to histopathology using a case study of lean implementation and evidence from the literature. It discusses the benefits, limitations, and pitfalls encountered when implementing lean management systems.

Applying Lean principles and Kaizen rapid improvement events in public health practice.

PubMed

Smith, Gene; Poteat-Godwin, Annah; Harrison, Lisa Macon; Randolph, Greg D

2012-01-01

This case study describes a local home health and hospice agency's effort to implement Lean principles and Kaizen methodology as a rapid improvement approach to quality improvement. The agency created a cross-functional team, followed Lean Kaizen methodology, and made significant improvements in scheduling time for home health nurses that resulted in reduced operational costs, improved working conditions, and multiple organizational efficiencies.

A parametric numerical study of mixing in a cylindrical duct

NASA Astrophysics Data System (ADS)

Oechsle, V. L.; Mongia, H. C.; Holderman, J. D.

1992-07-01

The interaction is described of some of the important parameters affecting the mixing process in a quick mixing region of a rich burn/quick mix/lean burn (RQL) combustor. The performance of the quick mixing region is significantly affected by the geometric designs of both the mixing domain and the jet inlet orifices. Several of the important geometric parameters and operating conditions affecting the mixing process were analytically studied. Parameters such as jet-to-mainstream momentum flux ratio (J), mass flow ratio (MR), orifice geometry, orifice orientation, and number of orifices/row (equally spaced around the circumferential direction were analyzed. Three different sets of orifice shapes were studied: (1) square, (2) elongated slots, and (3) equilateral triangles. Based on the analytical results, the best mixing configuration depends significantly on the penetration depth of the jet to prevent the hot mainstream flow from being entrained behind the orifice. The structure in a circular mixing section is highly weighted toward the outer wall and any mixing structure affecting this area significantly affects the overall results. The increase in the number of orifices per row increases the mixing at higher J conditions. Higher slot slant angles and aspect ratios are generally the best mixing configurations at higher momentum flux ratio (J) conditions. However, the square and triangular shaped orifices were more effective mixing configurations at lower J conditions.

Startup, Commissioning and Operation of Fenyi 100MW CFB Boiler

NASA Astrophysics Data System (ADS)

Wang, Zhiwei; Yu, Wugao; Bo, Shi

The first 100MW CFB boiler, designed by the Thermal Power Research Institute and manufactured by Harbin Boiler Company Limited, has been successfully running in Jiangxi Fenyi Power Plant since 2003. Local high ash content anthracite and lean coal that are very difficult to burn out are used in the 100 MW CFB boiler. The results of the 100MW CFB boiler shows that the CFB boiler can run in 30% MCR and startup with two under bed burners, and the boiler efficiency higher than 88% can be got after the combustion modification test. The CFB boiler can be operated with full load and reaches design parameters. The emissions of NO, N2O and CO are less than 7Omg/m3, 30mg/m3, and 125mg/m3, respectively, and SO2 less than 400mg/m3 after limestone injection. The bottom ash temperature from bed ash coolers is less than 120°C after its modification. Coal blockage at the coal storage silo is the main problem influencing the CFB boiler continuous operation. The running experiences for 5 years proved that the CFB boiler performance is successful, and the results were applied in 210 MW and 330 MW CFB Boiler design of Fenyi Power Plant.

Lean in service industries: A literature review

NASA Astrophysics Data System (ADS)

V, Vignesh; Suresh, M.; Aramvalarthan, S.

2016-09-01

Lean service is an amalgamation of tools and practices which, if applied appropriately, would definitely improve the existing quality of operations and ensure the generation of a large amount of favourable financial and economic outcomes and improve the behaviour of the workforce. As a result, it assumes of great significance in the fiercely competitive modern world. This article presents a comprehensive bibliographic study about the various lean service practices through a variety of approaches like service improvement, manufacturing, supply chain, market and retailing approaches, etc. Thus it gives a clear view on how the lean services are implemented in various sectors and the contribution of lean service towards improving the quality in the services provided while reducing the costs.

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

Rangaraj, D; Chan, K; Boddu, S

Lean thinking has revolutionized the manufacturing industry. Toyota has pioneered and leveraged this aspect of Lean thinking. Application of Lean thinking and Lean Six Sigma techniques into Healthcare and in particular in Radiation Oncology has its merits and challenges. To improve quality, safety and patient satisfaction with available resources or reducing cost in terms of time, staff and resources is demands of today's healthcare. Radiation oncology treatment involves many processes and steps, identifying and removing the non-value added steps in a process can significantly improve the efficiency. Real projects undertaken in radiation oncology department in cutting down the procedure timemore » for MRI guided brachytherapy to 40% less using lean thinking will be narrated. Simple Lean tools and techniques such as Gemba walk, visual control, daily huddles, standard work, value stream mapping, error-proofing, etc. can be applied with existing resources and how that improved the operation in a Radiation Oncology department's two year experience will be discussed. Lean thinking focuses on identifying and solving the root-cause of a problem by asking “Why” and not “Who” and this requires a culture change of no blame. Role of leadership in building lean culture, employee empowerment and trains and develops lean thinkers will be presented. Why Lean initiatives fail and how to implement lean successfully in your clinic will be discussed. Learning Objectives: Concepts of lean management or lean thinking. Lean tools and techniques applied in Radiation Oncology. Implement no blame culture and focus on system and processes. Leadership role in implementing lean culture. Challenges for Lean thinking in healthcare.« less

Improving first case start times using Lean in an academic medical center.

PubMed

Deldar, Romina; Soleimani, Tahereh; Harmon, Carol; Stevens, Larry H; Sood, Rajiv; Tholpady, Sunil S; Chu, Michael W

2017-06-01

Lean is a process improvement strategy that can improve efficiency of the perioperative process. The purpose of this study was to identify etiologies of late surgery start times, implement Lean interventions, and analyze their effects. A retrospective review of all first-start surgery cases was performed. Lean was implemented in May 2015, and cases 7 months before and after implementation were analyzed. A total of 4,492 first-start cases were included; 2,181 were pre-Lean and 2,311 were post-Lean. The post-Lean group had significantly higher on-time starts than the pre-Lean group (69.0% vs 57.0%, P < .01). The most common delay etiology was surgeon-related for both groups. Delayed post-Lean cases were significantly less likely to be due to preoperative assessment (14.9% vs 9.9%, P < .01) and more likely due to patient-related (16.5% vs 22.3%, P < .01) or chaplain (1.8% vs 4.0%, P < .01) factors. Delayed starts occurred more often on snowy and cold days, and less often on didactic days (P < .01). Modifying preoperative tasks using Lean methods can improve operating room efficiency and increase on-time starts. Copyright © 2016 Elsevier Inc. All rights reserved.

Increasing Operational Stability in Low NOX GT Combustor Using Fuel Rich Concentric Pilot Combustor

NASA Astrophysics Data System (ADS)

Levy, Yeshayahou; Erenburg, Vladimir; Sherbaum, Valery; Ovcharenko, Vitali; Rosentsvit, Leonid; Chudnovsky, Boris; Herszage, Amiel; Talanker, Alexander

2012-03-01

Lean combustion is a method in which combustion takes place under low equivalence ratio and relatively low combustion temperatures. As such, it has the potential to lower the effect of the relatively high activation energy nitrogen-oxygen reactions which are responsible for substantial NOX formation during combustion processes. However, lowering temperature reduces the reaction rate and deteriorates combustion stability. The objective of the present study is to reduce the lower equivalence ratio limit of the stable combustion operational boundary in lean Gas Turbine (GT) combustors while still maintaining combustion stability. A lean premixed gaseous combustor was equipped with a surrounding concentric pilot flame operating under rich conditions, thus generating a hot stream of combustion products with significant amount of reactive radicals. The main combustor's fuel-air composition was varied from stoichiometric to lean mixtures. The pilot's mixture composition was also varied by changing the air flow rate, within a limited rich mixtures range. The pilot fuel flow rate was always lower than five percent of the total fuel supply at the specific stage of the experiments.

Application of mixing-controlled combustion models to gas turbine combustors

NASA Technical Reports Server (NTRS)

Nguyen, Hung Lee

1990-01-01

Gas emissions were studied from a staged Rich Burn/Quick-Quench Mix/Lean Burn combustor were studied under test conditions encountered in High Speed Research engines. The combustor was modeled at conditions corresponding to different engine power settings, and the effect of primary dilution airflow split on emissions, flow field, flame size and shape, and combustion intensity, as well as mixing, was investigated. A mathematical model was developed from a two-equation model of turbulence, a quasi-global kinetics mechanism for the oxidation of propane, and the Zeldovich mechanism for nitric oxide formation. A mixing-controlled combustion model was used to account for turbulent mixing effects on the chemical reaction rate. This model assumes that the chemical reaction rate is much faster than the turbulent mixing rate.

Low NO sub x heavy fuel combustor concept program phase 1A gas tests

NASA Technical Reports Server (NTRS)

Cutrone, M. B.; Beebe, K. W.; Cutrone, M. B.

1982-01-01

The emissions performance of a rich lean combustor (developed for liquid fuels) for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf were assessed. 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. Although meeting NOx goals for the 167 Btu/scf gas, 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 generation from NH3 was significant at ammonia concentrations significantly less tha 0.5%. These levels occur depending on fuel gas cleanup system design, However, 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.

Mixing and NOx Emission Calculations of Confined Reacting Jet Flows in Cylindrical and Annular Ducts

NASA Technical Reports Server (NTRS)

Oechsle, Victor L.; Connor, Christopher H.; Holdeman, James D. (Technical Monitor)

2000-01-01

Rapid mixing of cold lateral jets with hot cross-stream flows in confined configurations is of practical interest in gas turbine combustors as it strongly affects combustor exit temperature quality, and gaseous emissions in for example rich-lean combustion. It is therefore important to further improve our fundamental understanding of the important processes of dilution jet mixing especially when the injected jet mass flow rate exceeds that of the cross-stream. The results reported in this report describe some of the main flow characteristics which develop in the mixing process in a cylindrical duct. A three-dimensional computational fluid dynamics (CFD) code has been used to predict the mixing flow field characteristics and NOx emission in a quench section of a rich-burn/quick-mix/lean-burn (RQL) combustor. Sixty configurations have been analyzed in both circular and annular geometries in a fully reacting environment simulating the operating condition of an actual RQL gas turbine combustion liner. The evaluation matrix was constructed by varying the number of orifices per row and orifice shape. Other parameters such as J (momentum-flux ratio), MR (mass flowrate ratio), DR (density ratio), and mixer sector orifice ACd (effective orifice area) were maintained constant throughout the entire study. The results indicate that the mixing flow field can be correlated with the NOx production if they are referenced with the stoichiometric equivalence ratio value and not the equilibrium value. The mixing flowfields in both circular and annular mixers are different. The penetration of equal jets in both annular and circular geometries is vastly different which significantly affects the performance of the mixing section. In the computational results with the circular mixer, most of the NOx formation occurred behind the orifice starting at the orifice wake region. General trends have been observed in the NOx production as the number of orifices is changed and this appears to be common for all hole configurations and mixer types (circular or annular). The performance of any orifice shape (in producing minimum NOx) appears to be acceptable if the number of orifices can be freely varied in order to attain the optimum jet penetration.

Breadboard Facility

NASA Technical Reports Server (NTRS)

1977-01-01

In the sixties, Chrysler was NASA's prime contractor for the Saturn I and IB test launch vehicles. The company installed and operated at Huntsville what was known as the Saturn I/IB Development Breadboard Facility. "Breadboard," means an array of electrical and electronic equipment for performing a variety of development and test functions. This work gave Chrysler a broad capability in computerized testing to assure quality control in development of solid-state electronic systems. Today that division is manufacturing many products not destined for NASA, most of them being associated with the company's automotive line. A major project is production and quality-control testing of the "lean-burn" engine, one that has a built-in Computer to control emission timing, and allow the engine to run on a leaner mixture of fuel and air. Other environment-related products include vehicle emission analyzers. The newest of the line is an accurate, portable solid state instrument for testing auto exhaust gases. The exhaust analyzers, now being produced for company dealers and for service

Gas turbine topping combustor

DOEpatents

Beer, Janos; Dowdy, Thomas E.; Bachovchin, Dennis M.

1997-01-01

A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

E3 Success Story - Whirlpool Trains Staff on Lean and Green Advantage

EPA Pesticide Factsheets

Whirlpool Corporation invited Green Suppliers Network representatives to its Monterrey facility to provide training on the Lean and Green Advantage. The project sought to expand E3 initiatives to every part of the company's operations.

Lean Mission Operations Systems Design - Using Agile and Lean Development Principles for Mission Operations Design and Development

NASA Technical Reports Server (NTRS)

Trimble, Jay Phillip

2014-01-01

The Resource Prospector Mission seeks to rove the lunar surface with an in-situ resource utilization payload in search of volatiles at a polar region. The mission operations system (MOS) will need to perform the short-duration mission while taking advantage of the near real time control that the short one-way light time to the Moon provides. To maximize our use of limited resources for the design and development of the MOS we are utilizing agile and lean methods derived from our previous experience with applying these methods to software. By using methods such as "say it then sim it" we will spend less time in meetings and more time focused on the one outcome that counts - the effective utilization of our assets on the Moon to meet mission objectives.

Whole body protein kinetics measured with a non-invasive method in severely burned children

PubMed Central

Børsheim, Elisabet; Chinkes, David L.; McEntire, Serina J.; Rodriguez, Nancy R.; Herndon, David N.; Suman, Oscar E.

2010-01-01

Persistent and extensive skeletal muscle catabolism is characteristic of severe burns. Whole body protein metabolism, an important component of this process, has not been measured in burned children during the long-term convalescent period. The aim of this study was to measure whole body protein turnover in burned children at discharge (95% healed) and in healthy controls by a non-invasive stable isotope method. Nine burned children (7 boys, 2 girls; 54 ± 14 (SD)% total body area burned; 13 ± 4 yrs; 45 ± 20 kg; 154 ± 14 cm) and 12 healthy children (8 boys, 4 girls; 12 ± 3 yrs; 54 ± 16 kg;150 ± 22 cm) were studied. A single oral dose of 15N-alanine (16 mg/kg) was given, and thereafter urine was collected for 34 hours. Whole body protein flux was calculated from labeling of urinary urea nitrogen. Then, protein synthesis was calculated as protein flux minus excretion, and protein breakdown as flux minus intake. At discharge, total protein turnover was 4.53 ± 0.65 (SE) g kg bodyweight−1 day−1 in the burned children compared to 3.20 ± 0.22 g kg−1 day−1 in controls (P = 0.02). Expressed relative to lean body mass (LBM), the rates were 6.12 ± 0.94 vs. 4.60 ± 0.36 g kg LBM−1 day−1 in burn vs. healthy (P = 0.06). Total protein synthesis was also elevated in burned vs. healthy children, and a tendency for elevated protein breakdown was observed. Conclusion: Total protein turnover is elevated in burned children at discharge compared to age-matched controls, possibly reflecting the continued stress response to severe burn. The oral 15N-alanine bolus method is a convenient, non-invasive, and no-risk method for measurement of total body protein turnover. PMID:20392565

Adoption of lean principles in a high-volume molecular diagnostic microbiology laboratory.

PubMed

Mitchell, P Shawn; Mandrekar, Jayawant N; Yao, Joseph D C

2014-07-01

Clinical laboratories are constantly facing challenges to do more with less, enhance quality, improve test turnaround time, and reduce operational expenses. Experience with adopting and applying lean concepts and tools used extensively in the manufacturing industry is described for a high-volume clinical molecular microbiology laboratory, illustrating how operational success and benefits can be achieved. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Considerations concerning the definition of sarcopenia.

PubMed

Dawson-Hughes, B; Bischoff-Ferrari, H

2016-11-01

In this commentary, we describe the sarcopenia spectrum that results in frailty and consider the impact of several components of the frailty definition on its global prevalence. We review proposed operational definitions of sarcopenia and the extent to which they have been shown to predict hard clinical outcomes, such as hip fracture, falls, and mortality. A head-to-head comparison of nine proposed operational definitions of sarcopenia as predictors of falls revealed that the definition involving appendicular lean mass (ALM)/ht 2 alone was a significant predictor; the prevalence of sarcopenia by this definition was 11 %. We consider the strengths and limitations of definitions that include functional measurements, such as gait speed and grip strength, along with measures of lean tissue mass. The functional assessments are harder to standardize than the more objective ALM measurements. The prevalence of sarcopenia by definitions that include functional and lean mass measurements tends to be lower than the prevalence by definitions that include lean mass alone. A low prevalence limits opportunity for early identification and application of prevention strategies. For these and other reasons, it seems advantageous to base the operational definition of sarcopenia on ALM/ht 2 alone. This commentary addresses the importance of a globally applicable operational definition of sarcopenia and both desirable and undesirable features of such a definition.

Determination of the combustion behavior for pure components and mixtures using a 20-liter sphere

NASA Astrophysics Data System (ADS)

Mashuga, Chad Victor

1999-11-01

The safest method to prevent fires and explosions of flammable vapors is to prevent the existence of flammable mixtures in the first place. This methodology requires detailed knowledge of the flammability region as a function of the fuel, oxygen, and nitrogen concentrations. A triangular flammability diagram is the most useful tool to display the flammability region, and to determine if a flammable mixture is present during plant operations. An automated apparatus for assessing the flammability region and for determining the potential effect of confined fuel-air explosions is described. Data derived from the apparatus included the limits of combustion, maximum combustion pressure, and the deflagration index, or KG. Accurate measurement of these parameters can be influenced by numerous experimental conditions, including igniter energy, humidity and gas composition. Gas humidity had a substantial effect on the deflagration index, but had little effect on the maximum combustion pressure. Small changes in gas compositions had a greater effect on the deflagration index than the maximum combustion pressure. Both the deflagration indices and the maximum combustion pressure proved insensitive to the range of igniter energies examined. Estimation of flammability limits using a calculated adiabatic flame temperature (CAFT) method is demonstrated. The CAFT model is compared with the extensive experimental data from this work for methane, ethylene and a 50/50 mixture of methane and ethylene. The CAFT model compares well to methane and ethylene throughout the flammability zone when using a 1200K threshold temperature. Deviations between the method and the experimental data occurs in the fuel rich region. For the 50/50 fuel mixture the CAFT deviates only in the fuel rich region---the inclusion of carbonaceous soot as one of the equilibrium products improved the fit. Determination of burning velocities from a spherical flame model utilizing the extensive pressure---time data was also completed. The burning velocities determined compare well to other investigators using this method. The data collected for the methane/ethylene mixture was used to evaluate mixing rules for the flammability limits, maximum combustion pressure, deflagration index, and burning velocity. These rules attempt to predict the behavior of fuel mixtures from pure component data. Le Chatelier's law and averaging both work well for predicting the flammability boundary in the fuel lean region and for mixtures of inerted fuel and air. Both methods underestimate the flammability boundary in the fuel rich region. For a mixture of methane and ethylene, we were unable to identify mixing rules for estimating the maximum combustion pressure and the burning velocity from pure component data. Averaging the deflagration indices for fuel air mixtures did provide a adequate estimation of the mixture behavior. Le Chatelier's method overestimated the maximum deflagration index in air but provided a satisfactory estimation in the extreme fuel lean and rich regions.

Attenuation of Posttraumatic Muscle Catabolism and Osteopenia by Long-Term Growth Hormone Therapy

PubMed Central

Hart, David W.; Herndon, David N.; Klein, Gordon; Lee, Steven B.; Celis, Mario; Mohan, Subburaman; Chinkes, David L.; Wolf, Steven E.

2001-01-01

Objective To determine whether the beneficial effects of growth hormone persist throughout the prolonged hypermetabolic and hypercatabolic response to severe burn. Summary Background Data The hypermetabolic response to severe burn is associated with increased energy expenditure, insulin resistance, immunodeficiency, and whole body catabolism that persists for months after injury. Growth hormone is a potent anabolic agent and salutary modulator of posttraumatic metabolic responses. Methods Seventy-two severely burned children were enrolled in a placebo-controlled double-blind trial investigating the effects of growth hormone (0.05 mg/kg per day) on muscle accretion and bone growth. Drug or placebo treatment began on discharge from the intensive care unit and continued for 1 year after burn. Total body weight, height, dual-energy x-ray absorptiometry, indirect calorimetry, and hormone values were measured at discharge, then at 6 months, 9 months, and 12 months after burn. Results were compared between groups. Results Growth hormone subjects gained more weight than placebo subjects at the 9-month study point; this disparity in weight gain continued to expand throughout the remainder of the study. Height also increased in the growth hormone group compared with controls at 12 months. Change in lean body mass was greater in those treated with growth hormone at 6, 9, and 12 months. Bone mineral content was increased at 9 and 12 months; this was associated with higher parathormone levels. Conclusions Low-dose recombinant human growth hormone successfully abates muscle catabolism and osteopenia induced by severe burn. PMID:11371741

Comparison of Estimated Energy Requirements in Severely Burned Patients With Measurements by Using Indirect Calorimetry

PubMed Central

Tancheva, D.; Arabadziev, J.; Gergov, G.; Lachev, N.; Todorova, S.; Hristova, A.

2005-01-01

Summary Severe burn injuries give rise to an extreme state of physiological stress. No other trauma results in such an accelerated rate of tissue catabolism, loss of lean body mass, and depletion of energy and protein reserves. A heightened attention to energy needs is essential, and the significance of adequate nutritional support in the complex management of patients with major burns is very important. The purpose of this study is to compare the results obtained by three of the most popular methods of estimating energy requirements in severely burned adult patients with the measurements of resting energy (REE) expenditure by indirect calorimetry (IC). A prospective study was carried out of 20 patients (male/female ratio, 17/3; mean age, 37.83 ± 10.86 yr), without accompanying morbidities, with burn injuries covering a mean body surface area of 34.27 ± 11.55% and a mean abbreviated burn severity index of 7.44 ± 1.58. During the first 30 days after trauma, the energy requirements were estimated using the Curreri, Long, and Toronto formulas. Twice weekly measurements of REE by IC were obtained. It was found that the Curreri and Long formulas overestimated the energy requirements in severely burned patients, as found by other investigators. However, no significant difference was found between the daily energy requirements calculated by the Toronto formula and the measured REE values by IC. It is concluded that the Toronto formula can be used as an alternative method for estimating the energy requirements of patients with major burns in cases where IC is not available or not applicable. PMID:21990973

Propranolol and Oxandrolone Therapy Accelerated Muscle Recovery in Burned Children.

PubMed

Chao, Tony; Porter, Craig; Herndon, David N; Siopi, Aikaterina; Ideker, Henry; Mlcak, Ronald P; Sidossis, Labros S; Suman, Oscar E

2018-03-01

Severe burns result in prolonged hypermetabolism and skeletal muscle catabolism. Rehabilitative exercise training (RET) programs improved muscle mass and strength in severely burned children. The combination of RET with β-blockade or testosterone analogs showed improved exercise-induced benefits on body composition and muscle function. However, the effect of RET combined with multiple drug therapy on muscle mass, strength, cardiorespiratory fitness, and protein turnover are unknown. In this placebo-controlled randomized trial, we hypothesize that RET combined with oxandrolone and propranolol (Oxprop) will improve muscle mass and function and protein turnover in severely burned children compared with burned children undergoing the same RET with a placebo. We studied 42 severely burned children (7-17 yr) with severe burns over 30% of the total body surface area. Patients were randomized to placebo (22 control) or to Oxprop (20) and began drug administration within 96 h of admission. All patients began RET at hospital discharge as part of their standardized care. Muscle strength (N·m), power (W), V˙O2peak, body composition, and protein fractional synthetic rate and fractional breakdown rate were measured pre-RET (PRE) and post-RET (POST). Muscle strength and power, lean body mass, and V˙O2peak increased with RET in both groups (P < 0.01). The increase in strength and power was significantly greater in Oxprop versus control (P < 0.01), and strength and power was greater in Oxprop over control POST (P < 0.05). Fractional synthetic rate was significantly higher in Oxprop than control POST (P < 0.01), resulting in improved protein net balance POST (P < 0.05). Rehabilitative exercise training improves body composition, muscle function, and cardiorespiratory fitness in children recovering from severe burns. Oxprop therapy augments RET-mediated improvements in muscle strength, power, and protein turnover.

The lean service machine.

PubMed

Swank, Cynthia Karen

2003-10-01

Jefferson Pilot Financial, a life insurance and annuities firm, like many U.S. service companies at the end of the 1990s was looking for new ways to grow. Its top managers recognized that JPF needed to differentiate itself in the eyes of its customers, the independent life-insurance advisers who sell and service policies. To establish itself as these advisers' preferred partner, it set out to reduce the turnaround time on policy applications, simplify the submission process, and reduce errors. JPF's managers looked to the "lean production" practices that U.S. manufacturers adopted in response to competition from Japanese companies. Lean production is built around the concept of continuous-flow processing--a departure from traditional production systems, in which large batches are processed at each step. JPF appointed a "lean team" to reengineer its New Business unit's operations, beginning with the creation of a "model cell"--a fully functioning microcosm of JPF's entire process. This approach allowed managers to experiment and smooth out the kinks while working toward an optimal design. The team applied lean-manufacturing practices, including placing linked processes near one another, balancing employees' workloads, posting performance results, and measuring performance and productivity from the customer's perspective. Customer-focused metrics helped erode the employees' "My work is all that matters" mind-set. The results were so impressive that JPF is rolling out similar systems across many of its operations. To convince employees of the value of lean production, the lean team introduced a simulation in which teams compete to build the best paper airplane based on invented customer specifications. This game drives home lean production's basic principles, establishing a foundation for deep and far-reaching changes in the production system.

A healthcare Lean Six Sigma System for postanesthesia care unit workflow improvement.

PubMed

Kuo, Alex Mu-Hsing; Borycki, Elizabeth; Kushniruk, Andre; Lee, Te-Shu

2011-01-01

The aim of this article is to propose a new model called Healthcare Lean Six Sigma System that integrates Lean and Six Sigma methodologies to improve workflow in a postanesthesia care unit. The methodology of the proposed model is fully described. A postanesthesia care unit case study is also used to demonstrate the benefits of using the Healthcare Lean Six Sigma System model by combining Lean and Six Sigma methodologies together. The new model bridges the service gaps between health care providers and patients, balances the requirements of health care managers, and delivers health care services to patients by taking the benefits of the Lean speed and Six Sigma high-quality principles. The full benefits of the new model will be realized when applied at both strategic and operational levels. For further research, we will examine how the proposed model is used in different real-world case studies.

Lean manufacturing: A better way for enhancement in productivity

NASA Astrophysics Data System (ADS)

Kumar Ahir, Pankaj; Kumar Yadav, Lalit; Singh Chandrawat, Saurabh

2012-03-01

Productivity is the impact of peoples working together. Machines are merely an extended way of collective imagination and energy. Lean Manufacturing is the most used method for continues improvement of business. Organization management philosophy focusing on the reduction of wastage to improve overall customer value. "Lean" operating principles began in manufacturing environments and are known by a variety of synonyms; Lean Manufacturing, Lean Production, Toyota Production System, etc. It is commonly believed that Lean started in Japan "The notable activities in keeping the price of Ford products low is the steady restriction of the production cycle. The longer an article is in the process of manufacture and the more it is moved about, the greater is its ultimate cost." "A systematic approach to identifying and eliminating waste through continuous improvement, flowing the product at the pull of the customer in pursuit of perfection."

Reactive Shear Layer Mixing and Growth Rate Effects on Afterburning Properties for Axisymetric Rocket Engine Plumes

DTIC Science & Technology

2006-09-01

water, carbon monoxide and carbon dioxide . The ratio of specific heats is reduced as the number of atoms in the molecule increases and as the...The flow of the jet is faster than the surrounding air, and since gas turbine engines run fuel lean, the exhaust products have generally fully reacted...previous types by several characteristics. The core of the rocket exhaust flowfield is fuel rich, and unlike gas turbine engines, which burn fuel

NPITxt, a 21st-Century Reporting System: Engaging Residents in a Lean-Inspired Process.

PubMed

Raja, Pushpa V; Davis, Michael C; Bales, Alicia; Afsarmanesh, Nasim

2015-05-01

Operational waste, or workflow processes that do not add value, is a frustrating but nonetheless largely tolerated barrier to efficiency and morale for medical trainees. In this article, the authors tested a novel reporting system using several submission formats (text messaging, e-mail, Web form, mobile application) to allow residents to report various types of operational waste in real time. This system informally promoted "lean" principles of waste identification and continuous improvement. In all, 154 issues were submitted between March 30, 2011, and June 30, 2012, and categorized as closely as possible into lean categories of operational waste; 131 issues were completely addressed with the requested outcome partially or fully implemented or with successful clarification of existing policies. A real-time, voluntary reporting system can effectively capture trainee observations of waste in health care and training processes, give trainees a voice in a hierarchical system, and lead to meaningful operations improvement. © 2014 by the American College of Medical Quality.

46 CFR 109.573 - Riveting, welding, and burning operations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Riveting, welding, and burning operations. 109.573 Section 109.573 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as...

46 CFR 109.573 - Riveting, welding, and burning operations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Riveting, welding, and burning operations. 109.573 Section 109.573 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as...

46 CFR 109.573 - Riveting, welding, and burning operations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Riveting, welding, and burning operations. 109.573 Section 109.573 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as...

46 CFR 109.573 - Riveting, welding, and burning operations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Riveting, welding, and burning operations. 109.573 Section 109.573 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as...

Advanced Light-Duty SI Engine Fuels Research: Multiple Optical Diagnostics of Well-mixed and Stratified Operation.

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

Sjoberg, Carl Magnus Goran; Vuilleumier, David

Ever tighter fuel economy standards and concerns about energy security motivate efforts to improve engine efficiency and to develop alternative fuels. This project contributes to the science base needed by industry to develop highly efficient direct injection spark ignition (DISI) engines that also beneficially exploit the different properties of alternative fuels. Here, the emphasis is on lean operation, which can provide higher efficiencies than traditional non-dilute stoichiometric operation. Since lean operation can lead to issues with ignition stability, slow flame propagation and low combustion efficiency, the focus is on techniques that can overcome these challenges. Specifically, fuel stratification is usedmore » to ensure ignition and completeness of combustion but this technique has soot and NOx emissions challenges. For ultra-lean well-mixed operation, turbulent deflagration can be combined with controlled end-gas autoignition to render mixed-mode combustion for sufficiently fast heat release. However, such mixed-mode combustion requires very stable inflammation, motivating studies on the effects of near-spark flow and turbulence, and the use of small amounts of fuel stratification near the spark plug.« less

The Statistical point of view of Quality: the Lean Six Sigma methodology

PubMed Central

Viti, Andrea; Terzi, Alberto

2015-01-01

Six Sigma and Lean are two quality improvement methodologies. The Lean Six Sigma methodology is applicable to repetitive procedures. Therefore, the use of this methodology in the health-care arena has focused mainly on areas of business operations, throughput, and case management and has focused on efficiency outcomes. After the revision of methodology, the paper presents a brief clinical example of the use of Lean Six Sigma as a quality improvement method in the reduction of the complications during and after lobectomies. Using Lean Six Sigma methodology, the multidisciplinary teams could identify multiple modifiable points across the surgical process. These process improvements could be applied to different surgical specialties and could result in a measurement, from statistical point of view, of the surgical quality. PMID:25973253

The Statistical point of view of Quality: the Lean Six Sigma methodology.

PubMed

Bertolaccini, Luca; Viti, Andrea; Terzi, Alberto

2015-04-01

Six Sigma and Lean are two quality improvement methodologies. The Lean Six Sigma methodology is applicable to repetitive procedures. Therefore, the use of this methodology in the health-care arena has focused mainly on areas of business operations, throughput, and case management and has focused on efficiency outcomes. After the revision of methodology, the paper presents a brief clinical example of the use of Lean Six Sigma as a quality improvement method in the reduction of the complications during and after lobectomies. Using Lean Six Sigma methodology, the multidisciplinary teams could identify multiple modifiable points across the surgical process. These process improvements could be applied to different surgical specialties and could result in a measurement, from statistical point of view, of the surgical quality.

Division of overall duration of stay into operative stay and postoperative stay improves the overall estimate as a measure of quality of outcome in burn care

PubMed Central

Olofsson, Pia; Fredrikson, Mats; Sjoberg, Folke

2017-01-01

Total duration of stay adjusted for percentage of the total body surface area burned (TBSA%) is a commonly used outcome measure in burn care. However, it has been criticised as it is affected by many factors, some of which are not strictly part of burn care. A division into operative stay and postoperative stay may improve this measure. The aim was to evaluate if operative stay can serve as a more standardised measure by: comparing the variation in operative stay/TBSA% with the variation in total stay/TBSA%, and to study different factors associated with operative stay and postoperative stay. Patients and methods Surgically managed burn patients admitted between 2010–14 were included. Operative stay was defined as the time from admission until the last operation, postoperative stay as the time from the last operation until discharge. The difference in variation was analysed with F-test. A retrospective review of medical records was done to explore reasons for extended postoperative stay. Multivariable regression was used to assess factors associated with operative stay and postoperative stay. Results Operative stay/TBSA% showed less variation than total duration/TBSA% (F test = 2.38, p<0.01). The size of the burn, and the number of operations, were the independent factors that influenced operative stay (R2 0.65). Except for the size of the burn other factors were associated with duration of postoperative stay: wound related, psychological and other medical causes, advanced medical support, and accommodation arrangements before discharge, of which the two last were the most important with an increase of (mean) 12 and 17 days (p<0.001, R2 0.51). Conclusion Adjusted operative stay showed less variation than total hospital stay and thus can be considered a more accurate outcome measure for surgically managed burns. The size of burn and number of operations are the factors affecting this outcome measure. PMID:28362844

Evaluation de l'effet des concepts de la production allegee dans une entreprise aeronautique

NASA Astrophysics Data System (ADS)

Moknine, Myriam

This research focuses on a project to implement a Lean approach in Quebec's aerospace business, that of Bombardier Aerospace. Developed for the automobile industry since the 1950s, the Lean has expanded its practices to various industry sectors, including the international aircraft industry, and more specifically the Quebec aircraft industry. Today, numerous companies turn more and more to the Lean Manufacturing approach to improve their competitiveness and their performance levels. The review of the literature on the Lean has allowed us to further understand the topic and more specifically its application in the aerospace sector. The Lean approach allows the improvement of operational performance indicators such as the reduction of production costs, cycle times, travel and inventories, as well as the improvement of the versatility of employees. The Lean has succeeded where many other organisational models have failed. Several success factors such as employee involvement, leadership commitment, proper integration of all tools and many others must be used in the implementation of such production practice. However, this approach is sometimes criticized by some authors who suggest that the improvements made by the Lean result in an increase in the workload of employees and a deterioration of their stress levels. Our research on the Lean has revealed gaps in available and existing research and data on the subject, particularly in the aerospace sector. This research has helped to fill this important gap, by documenting the context and highlighting the impact of the Lean on a production system in the Quebec aerospace components. A machining center having deployed a Lean approach was chosen to conduct a case study in post-implantation. Tools for data collection such as observations on the production floor, semi-structured interviews, as well as the Lean checklist, were used to perform this case study. The case study has confirmed the positive impact of Lean on operational performance indicators of the company. The results of this case study showed a reduction of cycle time of 49%, a reduction of unnecessary employee travels of 50% and a reduction of production costs by about 50%. In addition to these positive discoveries, our study has highlighted an important human benefit in the business such as an improvement in the versatility of employees by 25%. In addition, the study also demonstrated that the integration and assimilation of the Lean concepts is made with a proven success. Indeed, analysis on results from the checklist showed that the level of Lean concepts maturity progressed favorably in the period from pre-project until that in post-project. This research brings an added value to the scientific literature. It thus helps to disseminate data in a Lean implementation in a production area of Quebec aerospace products.

Fires and Burns Occurring in an Electrocautery after Skin Preparation with Alcohol during a Neurosurgery

PubMed Central

Chae, Sang-Bae; Yoo, Chan-Jong; Park, Cheol-Wan

2014-01-01

While there are reports regarding burns occurring to patients during the surgery, there are little reports concerning the incidents of the burns related to neurosurgical operations. Moreover, in Korea, even surveys and statistics on the incidents of burns in operating rooms are not known. This report explores burns occurring to a patient in an electrocautery scenario after disinfecting the surgical site with alcohol during the preparation of a neurosurgical operation in an operating room where there is much exposure to oxygen. The authors show a case of a 33-year-old male patient who undergoing evacuation of hematoma on occipital lesion, suffered second degree burns as a result of surgical fires. PMID:25024831

Integrating Lean Exploration Loops Into Healthcare Facility Design.

PubMed

Mazur, Lukasz M; Johnson, Kendra; Pooya, Pegah; Chadwick, Janet; McCreery, John

2017-04-01

To explore what, when, and how Lean methods and tools can add value during the programming phase of design through providing additional resources and support to project leadership and the architectural design team. This case study-based research took place at one large academic hospital during design efforts of a surgical tower to house 19 operating rooms (ORs) and support spaces including pre- and postop, central processing and distribution, and materials management. Surgical services project leadership asked for support from Lean practitioners during the design process. Lean exploration loops (LELs) were conducted to generate evidence to support stakeholders, as they made important decisions about the new building design. The analyses conducted during LELs were primarily focused on the relative advantages of a large footprint with few floors or a smaller footprint with more floors and support spaces not collocated adjacent to ORs on the same floor. LELs resulted in quantifications of key operational and design features (e.g., design preferences of employees and patients, horizontal distance travel, and elevator utilization studies), which in turn complemented the architectural design process and created an opportunities to gain buy-in and consensus from stakeholders through their active participation in many of the analyses. We found Lean tools and methods to be of most value during programming phase when focused on the high-level operational and design issues to help establish buy-in and consensus among stakeholders, while acknowledging that there is often not enough design detail to perform accurate analysis.

Burn hazards of the deployed environment in wartime: epidemiology of noncombat burns from ongoing United States military operations.

PubMed

Kauvar, David S; Wade, Charles E; Baer, David G

2009-10-01

Service in the deployed military environment carries risks for accidental (noncombat-related) burns. Examining these risks can assist in the development of military burn prevention measures. This study endeavored to examine noncombat burn epidemiology in the context of similar civilian data. We performed a retrospective cohort study of consecutive casualties evacuated from operational military theaters in Iraq and Afghanistan to the sole tertiary military burn center in the US. Military data were compared with database samples of the US population from the American Burn Association and the Centers for Disease Control and Prevention. The main causes of the 180 noncombat burns seen from March 2003 to June 2008 were waste burning, fuel mishaps, and unintentional ordinance detonations. Overall prevalence of noncombat burns was 19.5 burns/100,000 person-years lived. If causes specific to military operations are removed, military prevalence was 13.0/100,000. More than one-third of noncombat burns occurred in the first year of the study; a period of stability followed. A similar US population had an accidental burn prevalence of 7.1/100,000 from 2003 to 2007. Burn size, presence of inhalation injury, and burn center mortality were not different from those in a similar civilian cohort. Deployed service members have a greater risk of unintentional burns than a similar civilian cohort does. This is in part because of the specific dangers of military activities. More attention to deployed military burn prevention is needed, especially early in combat support operations.

Readiness factors for lean implementation in healthcare settings--a literature review.

PubMed

Al-Balushi, S; Sohal, A S; Singh, P J; Al Hajri, A; Al Farsi, Y M; Al Abri, R

2014-01-01

The purpose of this paper is to determine the readiness factors that are critical to the application and success of lean operating principles in healthcare organizations through a review of relevant literature. A comprehensive review of literature focussing on lean and lean healthcare was conducted. Leadership, organizational culture, communication, training, measurement, and reward systems are all commonly attributed readiness factors throughout general change management and lean literature. However, directly related to the successful implementation of lean in healthcare is that a setting is able to authorize a decentralized management style and undertake an end-to-end process view. These can be particularly difficult initiatives for complex organizations such as healthcare settings. The readiness factors identified are based on a review of the published literature. The external validity of the findings could be enhanced if tested using an empirical study. The readiness factors identified will enable healthcare practitioners to be better prepared as they begin their lean journeys. Sustainability of the lean initiative will be at stake if these readiness factors are not addressed. To the best of the knowledge, this is the first paper that provides a consolidated list of key lean readiness factors that can guide practice, as well as future theory and empirical research.

Initial Neutron Burn Truncation Experiments on OMEGA

NASA Astrophysics Data System (ADS)

McKenty, P. W.; Keck, R. L.; Kremens, R. L.; Kearney, K. J.; Verdon, C. P.; Zuegel, J. D.; Cable, M. D.; Ognibene, T. J.; Lerche, R. A.; Griffith, R. L.

1997-11-01

The recent deployment of the neutron temporal diagnostic (NTD) on OMEGA has enabled us to perform a series of experiments that will serve as a base line in understanding the effects of various levels of irradiation nonuniformities on neutron burn rates. These experiments were performed using doped and undoped plastic microballoons imploded with 30 kJ of 351-nm (UV) light. Precise control of laser focusing on OMEGA allowed for on-target laser perturbations to be varied from 0.1 to 1.0 μ*m rms. The targets were designed for moderate convergence ( ~*10) and spanned a range of growth factor from ~*50 to 500 ( ~*4 to 6 total e-foldings). Results will be presented depicting the experimental Y*ield O*ver C*lean (YOC) one-dimensionally predicted yield as a function of the calculated distortion fraction and an appraisal of the experimental fuel areal density. Both of these will be evaluated using information gained from the examination of the NTD neutron burn curves. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

CFD analysis of jet mixing in low NOx flametube combustors

NASA Technical Reports Server (NTRS)

Talpallikar, M. V.; Smith, C. E.; Lai, M. C.; Holdeman, J. D.

1991-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor was identified as a potential gas turbine combustor concept to reduce NO(x) emissions in High Speed Civil Transport (HSCT) aircraft. To demonstrate reduced NO(x) levels, cylindrical flametube versions of RQL combustors are being tested at NASA Lewis Research Center. A critical technology needed for the RQL combustor is a method of quickly mixing by-pass combustion air with rich-burn gases. Jet mixing in a cylindrical quick-mix section was numerically analyzed. The quick-mix configuration was five inches in diameter and employed twelve radial-inflow slots. The numerical analyses were performed with an advanced, validated 3-D Computational Fluid Dynamics (CFD) code named REFLEQS. Parametric variation of jet-to-mainstream momentum flux ratio (J) and slot aspect ratio was investigated. Both non-reacting and reacting analyses were performed. Results showed mixing and NO(x) emissions to be highly sensitive to J and slot aspect ratio. Lowest NO(x) emissions occurred when the dilution jet penetrated to approximately mid-radius. The viability of using 3-D CFD analyses for optimizing jet mixing was demonstrated.

CFD analysis of jet mixing in low NO(x) flametube combustors

NASA Technical Reports Server (NTRS)

Talpallikar, M. V.; Smith, C. E.; Lai, M. C.; Holdeman, J. D.

1991-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor has been identified as a potential gas turbine combustor concept to reduce NO(x) emissions in High Speed Civil Transport (HSCT) aircraft. To demonstrate reduced NO(x) levels, cylindrical flametube versions of RQL combustors are being tested at NASA Lewis Research Center. A critical technology needed for the RQL combustor is a method of quickly mixing by-pass combustion air with rich-burn gases. Jet mixing in a cylindrical quick-mix section was numerically analyzed. The quick-mix configuration was five inches in diameter and employed twelve radial-inflow slots. The numerical analyses were performed with an advanced, validated 3D Computational Fluid Dynamics (CFD) code named REFLEQS. Parametric variation of jet-to-mainstream momentum flux ratio (J) and slot aspect ratio was investigated. Both non-reacting and reacting analyses were performed. Results showed mixing and NO(x) emissions to be highly sensitive to J and slot aspect ratio. Lowest NO(x) emissions occurred when the dilution jet penetrated to approximately mid-radius. The viability of using 3D CFD analyses for optimizing jet mixing was demonstrated.

46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions—TB... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or like...

46 CFR 109.573 - Riveting, welding, and burning operations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines, heating...

46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB... making alterations, repairs, or other such operations involving riveting, welding, burning, or like fire... with safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions—TB... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or like...

Methane Emissions from Leak and Loss Audits of Natural Gas Compressor Stations and Storage Facilities.

PubMed

Johnson, Derek R; Covington, April N; Clark, Nigel N

2015-07-07

As part of the Environmental Defense Fund's Barnett Coordinated Campaign, researchers completed leak and loss audits for methane emissions at three natural gas compressor stations and two natural gas storage facilities. Researchers employed microdilution high-volume sampling systems in conjunction with in situ methane analyzers, bag samples, and Fourier transform infrared analyzers for emissions rate quantification. All sites had a combined total methane emissions rate of 94.2 kg/h, yet only 12% of the emissions total resulted from leaks. Methane slip from exhausts represented 44% of the total emissions. Remaining methane emissions were attributed to losses from pneumatic actuators and controls, engine crankcases, compressor packing vents, wet seal vents, and slop tanks. Measured values were compared with those reported in literature. Exhaust methane emissions were lower than emissions factor estimates for engine exhausts, but when combined with crankcase emissions, measured values were 11.4% lower than predicted by AP-42 as applicable to emissions factors for four-stroke, lean-burn engines. Average measured wet seal emissions were 3.5 times higher than GRI values but 14 times lower than those reported by Allen et al. Reciprocating compressor packing vent emissions were 39 times higher than values reported by GRI, but about half of values reported by Allen et al. Though the data set was small, researchers have suggested a method to estimate site-wide emissions factors for those powered by four-stroke, lean-burn engines based on fuel consumption and site throughput.

Response of flame thickness and propagation speed under intense turbulence in spatially developing lean premixed methane–air jet flames

DOE PAGES

Sankaran, Ramanan; Hawkes, Evatt R.; Yoo, Chun Sang; ...

2015-06-22

Direct numerical simulations of three-dimensional spatially-developing turbulent Bunsen flames were performed at three different turbulence intensities. We performed these simulations using a reduced methane–air chemical mechanism which was specifically tailored for the lean premixed conditions simulated here. A planar-jet turbulent Bunsen flame configuration was used in which turbulent preheated methane–air mixture at 0.7 equivalence ratio issued through a central jet and was surrounded by a hot laminar coflow of burned products. The turbulence characteristics at the jet inflow were selected such that combustion occured in the thin reaction zones (TRZ) regime. At the lowest turbulence intensity, the conditions fall onmore » the boundary between the TRZ regime and the corrugated flamelet regime, and progressively moved further into the TRZ regime by increasing the turbulent intensity. The data from the three simulations was analyzed to understand the effect of turbulent stirring on the flame structure and thickness. Furthermore, statistical analysis of the data showed that the thermal preheat layer of the flame was thickened due to the action of turbulence, but the reaction zone was not significantly affected. A global and local analysis of the burning velocity of the flame was performed to compare the different flames. Detailed statistical averages of the flame speed were also obtained to study the spatial dependence of displacement speed and its correlation to strain rate and curvature.« less

ILIDS measurements of the evaporation of fuel droplets during the intake and compression strokes in a firing lean burn engine

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

Skippon, S.M.; Tagaki, Y.

1996-09-01

The evaporation of fuel droplets is an important factor in determining the quality of mixture preparation in lean-burn engines, particularly when using open-valve injection timing, which results in large in-cylinder droplet populations. Interferometric Laser Imaging for Droplet Sizing (ILIDS) has been used to measure the in-cylinder droplet size distribution and fuel volume in the droplet phase as a function of crank angle for a typical full boiling range gasoline and three single component fuels with different boiling points: iso-pentane, iso-octane, and xylene, representing the volatilities of the light end, mid-range and heavy ends of a typical gasoline. The measurements weremore » made under firing conditions, with both open and closed valve injection timing, and at two different coolant temperatures, representing simulated cold start and fully warmed up conditions. A specially built single cylinder research engine was used, equipped with a transparent sapphire cylinder to provide all-round sidewall optical access to the cylinder interior. The engine had a four-valve leanburn head, swirl control valve and air-assisted injector. The experimental arrangements for ILIDS in a firing engine, and the optical access engine itself, are discussed in detail. The results showed significant differences in the rates of evaporation of the three fuel components: iso-pentane evaporated fully very early in the induction stroke, iso-octane droplets persisted longer, and xylene droplets persisted to the end of the compression stroke.« less

[Influence of three-level collaboration network of pediatric burns treatment in Anhui province on treatment effects of burn children].

PubMed

Xia, Z G; Zhou, X L; Kong, W C; Li, X Z; Song, J H; Fang, L S; Hu, D L; Cai, C; Tang, Y Z; Yu, Y X; Wang, C H; Xu, Q L

2018-03-20

Objective: To explore the influence of three-level collaboration network of pediatric burns in Anhui province on treatment effects of burn children. Methods: The data of medical records of pediatric burn children transferred from Lu'an People's Hospital and Fuyang People's Hospital to the First Affiliated Hospital of Anhui Medical University from January 2014 to December 2015 and January 2016 to September 2017 (before and after establishing three-level collaboration network of pediatric burns treatment) were analyzed: percentage of transferred burn children to hospitalized burn children in corresponding period, gender, age, burn degree, treatment method, treatment result, occurrence and treatment result of shock, and operative and non-operative treatment time and cost. Rehabilitation result of burn children transferred back to local hospitals in 2016 and 2017. Data were processed with t test, chi-square test, Mann-Whitney U test, and Fisher's exact test. Results: (1) Percentage of burn children transferred from January 2014 to December 2015 was 34.3% (291/848) of the total number of hospitalized burn children in the same period of time, which was close to 30.4% (210/691) of burn children transferred from January 2016 to September 2017 ( χ (2)=2.672, P >0.05). (2) Gender, age, burn degree, and treatment method of burn children transferred from the two periods of time were close ( χ (2)=3.382, Z =-1.917, -1.911, χ (2)=3.133, P >0.05). (3) Cure rates of children with mild, moderate, and severe burns transferred from January 2016 to September 2017 were significantly higher than those of burn children transferred from January 2014 to December 2015 ( χ (2)=11.777, 6.948, 4.310, P <0.05). Cure rates of children with extremely severe burns transferred from the two periods of time were close ( χ (2)=1.181, P >0.05). (4) Children with mild and moderate burns transferred from the two periods of time were with no shock. The incidence of shock of children with severe burns transferred from January 2014 to December 2015 was 6.0% (4/67), and 3 children among them were cured. The incidence of shock of children with severe burns transferred from January 2016 to September 2017 was 3.9% (2/51), and both children were cured. The incidences and cures of shock of children with severe burns transferred from the two periods of time were close ( χ (2)=0.006, P >0.05). Incidence of shock of children with extremely severe burns transferred from January 2014 to December 2015 was 57.1% (32/56), significantly higher than that of burn children transferred from January 2016 to September 2017 [34.5% (10/29), χ (2)=3.925, P <0.05]. Shock of 25 children with extremely severe burns transferred from January 2014 to December 2015 were cured, and shock of 9 children with extremely severe burns transferred from January 2016 to September 2017 were cured. The cures of shock of children with extremely severe burns transferred from the two periods of time were close ( χ (2)=0.139, P >0.05). (5) Time of operative treatment of children with moderate, severe, and extremely severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 ( t =2.335, 2.065, 2.310, P <0.05). Time of operative treatment of children with mild burns transferred from the two periods of time was close ( Z =-0.417, P >0.05). Costs of operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were significantly more than those of burn children transferred from January 2016 to September 2017 ( Z =-3.324, t =2.167, P <0.05). Costs of operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close ( t =0.627, 0.808, P >0.05). (6)Time of non-operative treatment of children with mild, moderate, and severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 ( t =2.335, Z =-2.095, t =2.152, P <0.05). Time of non-operative treatment of children with extremely severe burns transferred from the two periods of time was close ( t =0.450, P >0.05). Costs of non-operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were obviously higher than those of burn children transferred from January 2016 to September 2017 ( Z =-2.164, t =2.040, P <0.05). Costs of non-operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close ( t =0.146, 1.235, P >0.05). (7) Sixty-seven burn children transferred from January 2016 to September 2017 were transferred back to local hospitals for rehabilitation under the guidance of experts of the First Affiliated Hospital of Anhui Medical University, with 25 patients in 2016 and 42 patients in 2017. Effective rehabilitation rates of burn children transferred back to local hospitals for rehabilitation in 2016 and 2017 were both 100%. Conclusions: The three-level collaboration network of pediatric burns treatment in Anhui province can effectively increase cure rate of children with mild, moderate, and severe burns, reduce incidence of shock of children with extremely severe burns, shorten time of operative treatment of burn children with moderate, severe, and extremely severe burns, and time of non-operative treatment of children with mild, moderate, and severe burns, reduce treatment costs of children with moderate and severe burns, and improve rehabilitation effectiveness of children transferred from Lu'an People's Hospital and Fuyang People's Hospital to the the First Affiliated Hospital of Anhui Medical University.

Effects of Karlovitz number on turbulent kinetic energy transport in turbulent lean premixed methane/air flames

NASA Astrophysics Data System (ADS)

Wang, Zhiyan; Abraham, John

2017-08-01

Direct numerical simulations of lean methane/air flames are carried out to study the effects of premixed combustion on turbulence. The equivalence ratio of the flame is 0.5 and non-dimensional turbulence intensities (urms/SL) are between 2 and 25. The mixture pressure is 20 bars and temperature is 810 K to simulate approximate conditions in lean-burn natural gas engines. The Karlovitz number (Ka) varies from 1.1 to 49.4, and the Damköhler number (Da) varies from 0.26 to 3.2 corresponding to turbulent premixed combustion in the thin reaction zone (TRZ) regime. It is found that turbulence kinetic energy (TKE) and its dissipation rate decrease monotonically across the flame brush while the integral length scale increases monotonically for flames in the TRZ regime. The transport equation of TKE is then examined, and the scaling of the terms in the equation is discussed. It is found that the sink term which represents molecular diffusion and viscous dissipation is the dominant term in the TKE balance and it scales with the square of Ka. The relative importance of the other terms with respect to the dissipation term is studied. With increasing Ka, the other terms in the TKE balance become less important compared to the dissipation term.

Effects of organizational context on Lean implementation in five hospital systems.

PubMed

Harrison, Michael I; Paez, Kathryn; Carman, Kristin L; Stephens, Jennifer; Smeeding, Lauren; Devers, Kelly J; Garfinkel, Steven

2016-01-01

Despite broad agreement among researchers about the value of examining how context shapes implementation of improvement programs and projects, limited attention has been paid to contextual effects on implementation of Lean. To help reduce gaps in knowledge of effects of intraorganizational context, we researched Lean implementation initiatives in five organizations and examined 12 of their Lean rapid improvement projects. All projects aimed at improving clinical care delivery. On the basis of the literature on Lean, innovation, and quality improvement, we developed a framework of factors likely to affect Lean implementation and outcomes. Drawing on the framework, we conducted semistructured interviews and applied qualitative codes to the transcribed interviews. Available documents, data, and observations supplemented the interviews. We constructed case studies of Lean implementation in each organization, compared implementation across organizations, and compared the 12 projects. Intraorganizational characteristics affecting organization-wide Lean initiatives and often also shaping project outcomes included CEO commitment to Lean and active support for it, prior organizational capacity for quality improvement-based performance improvement, alignment of the Lean initiative with the organizational mission, dedication of resources and experts to Lean, staff training before and during projects, establishment of measurable and relevant project targets, planning of project sequences that enhance staff capabilities and commitment without overburdening them, and ensuring communication between project members and other affected staff. Dependence of projects on inputs of new information technology was a barrier to project success. Incremental implementation of Lean produced reported improvements in operational efficiency and occasionally in care quality. However, even under the relatively favorable circumstances prevailing in our study sites, incremental implementation did not readily change organizational culture. This study should alert researchers, managers, and teachers of management to ways that contexts shape Lean implementation and may affect other types of process redesign and quality improvement.

Application of lean manufacturing techniques in the Emergency Department.

PubMed

Dickson, Eric W; Singh, Sabi; Cheung, Dickson S; Wyatt, Christopher C; Nugent, Andrew S

2009-08-01

"Lean" is a set of principles and techniques that drive organizations to continually add value to the product they deliver by enhancing process steps that are necessary, relevant, and valuable while eliminating those that fail to add value. Lean has been used in manufacturing for decades and has been associated with enhanced product quality and overall corporate success. To evaluate whether the adoption of Lean principles by an Emergency Department (ED) improves the value of emergency care delivered. Beginning in December 2005, we implemented a variety of Lean techniques in an effort to enhance patient and staff satisfaction. The implementation followed a six-step process of Lean education, ED observation, patient flow analysis, process redesign, new process testing, and full implementation. Process redesign focused on generating improvement ideas from frontline workers across all departmental units. Value-based and operational outcome measures, including patient satisfaction, expense per patient, ED length of stay (LOS), and patient volume were compared for calendar year 2005 (pre-Lean) and periodically after 2006 (post-Lean). Patient visits increased by 9.23% in 2006. Despite this increase, LOS decreased slightly and patient satisfaction increased significantly without raising the inflation adjusted cost per patient. Lean improved the value of the care we delivered to our patients. Generating and instituting ideas from our frontline providers have been the key to the success of our Lean program. Although Lean represents a fundamental change in the way we think of delivering care, the specific process changes we employed tended to be simple, small procedure modifications specific to our unique people, process, and place. We, therefore, believe that institutions or departments aspiring to adopt Lean should focus on the core principles of Lean rather than on emulating specific process changes made at other institutions.

Method and apparatus to selectively reduce NO.sub.x in an exhaust gas feedstream

DOEpatents

Schmieg, Steven J [Troy, MI; Blint, Richard J [Shelby Township, MI; Den, Ling [Sterling Heights, MI; Viola, Michael B [Macomb Township, MI; Lee, Jong-Hwan [Rochester Hills, MI

2011-08-30

A method and apparatus are described to selectively reduce NO.sub.x emissions of an internal combustion engine. An exhaust aftertreatment system includes an injection device operative to dispense a hydrocarbon reductant upstream of a silver-alumina catalytic reactor device. A control system determines a NO.sub.x concentration and hydrocarbon/NOx ratio based upon selected parameters of the exhaust gas feedstream and dispenses hydrocarbon reductant during lean engine operation. Included is a method to control elements of the feedstream during lean operation. The hydrocarbon reductant may include engine fuel.

Lean Thinking in Libraries: A Case Study on Improving Shelving Turnaround

ERIC Educational Resources Information Center

Kress, Nancy J.

2007-01-01

The University of Chicago's Joseph Regenstein Library Bookstacks Department has used process mapping and continuous improvement to successfully improve its overall operations. The most recent efforts focus on Lean manufacturing, an initiative centered on eliminating waste in manufacturing processes. The conversion of the Bookstacks Department from…

Flame stabilization and mixing characteristics in a Stagnation Point Reverse Flow combustor

NASA Astrophysics Data System (ADS)

Bobba, Mohan K.

A novel combustor design, referred to as the Stagnation Point Reverse-Flow (SPRF) combustor, was recently developed that is able to operate stably at very lean fuel-air mixtures and with low NOx emissions even when the fuel and air are not premixed before entering the combustor. The primary objective of this work is to elucidate the underlying physics behind the excellent stability and emissions performance of the SPRF combustor. The approach is to experimentally characterize velocities, species mixing, heat release and flame structure in an atmospheric pressure SPRF combustor with the help of various optical diagnostic techniques: OH PLIF, chemiluminescence imaging, PIV and Spontaneous Raman Scattering. Results indicate that the combustor is primarily stabilized in a region downstream of the injector that is characterized by low average velocities and high turbulence levels; this is also the region where most of the heat release occurs. High turbulence levels in the shear layer lead to increased product entrainment levels, elevating the reaction rates and thereby enhancing the combustor stability. The effect of product entrainment on chemical timescales and the flame structure is illustrated with simple reactor models. Although reactants are found to burn in a highly preheated (1300 K) and turbulent environment due to mixing with hot product gases, the residence times are sufficiently long compared to the ignition timescales such that the reactants do not autoignite. Turbulent flame structure analysis indicates that the flame is primarily in the thin reaction zones regime throughout the combustor, and it tends to become more flamelet like with increasing distance from the injector. Fuel-air mixing measurements in case of non-premixed operation indicate that the fuel is shielded from hot products until it is fully mixed with air, providing nearly premixed performance without the safety issues associated with premixing. The reduction in NOx emissions in the SPRF combustor are primarily due to its ability to stably operate under ultra lean (and nearly premixed) condition within the combustor. Further, to extend the usefulness of this combustor configuration to various applications, combustor geometry scaling rules were developed with the help of simplified coaxial and opposed jet models.

Lean oncology: a new model for oncologists.

PubMed

Montesarchio, Vincenzo; Grimaldi, Antonio Maria; Fox, Bernard A; Rea, Antonio; Marincola, Francesco M; Ascierto, Paolo A

2012-04-25

The history of the term Lean is relatively recent and originates from the Toyota Production System (TPS). The term "Lean" means "thin", which refers to a mental process, operational, productive, no-frills, quick but not hasty, consequential to the previous event. The Lean process flows seamlessly into the result, eliminates unnecessary complications to the effect, prevents unnecessary equipment processes. The idea is to 'do more with less', like using the (few) available resources in the most productive way possible, through the elimination of all types of waste that inevitably accompanies every stage of a production process. Lean management is primarily a management philosophy, a system of values and behaviors that goes beyond the mere application of the instrument and that, once internalized, will form the nucleus of the corporate culture. "Lean Oncology" is a term coined to identify a methodology of care and treatment to cancer patients, consisting on process simplification, streamlining of the organizational and routes of drug treatment, detection and elimination of waste. Its main objective is the centrality of the patient.

Lean management-the journey from toyota to healthcare.

PubMed

Teich, Sorin T; Faddoul, Fady F

2013-04-01

The evolution of production systems is tightly linked to the story of Toyota Motor Company (TMC) that has its roots around 1918. The term "lean" was coined in 1990 following the exploration of the Toyota model that led to the "transference" thesis sustaining the concept that manufacturing problems and technologies are universal problems faced by management and that these concepts can be emulated in non-Japanese enterprises. Lean is a multi-faceted concept and requires organizations to exert effort along several dimensions simultaneously; some consider a successful implementation either achieving major strategic components of lean, implementing practices to support operational aspects, or providing evidence that the improvements are sustainable in the long term. The article explores challenges and opportunities faced by organizations that intend incorporating lean management principles and presents the specific context of the healthcare industry. Finally, the concepts of "essential few" and customer value are illustrated through a simple example of process change following lean principles, which was implemented in a dental school in the United States.

Surgical Burn Care by Médecins Sans Frontières-Operations Center Brussels: 2008 to 2014.

PubMed

Stewart, Barclay T; Trelles, Miguel; Dominguez, Lynette; Wong, Evan; Fiozounam, Hervé Tribunal; Hassani, Ghulam Hiadar; Akemani, Clemence; Naseer, Aemer; Ntawukiruwabo, Innocent Bagura; Kushner, Adam L

Humanitarian organizations care for burns during crisis and while supporting healthcare facilities in low-income and middle-income countries. This study aimed to define the epidemiology of burn-related procedures to aid humanitarian response. In addition, operational data collected from humanitarian organizations are useful for describing surgical need otherwise unmet by national health systems. Procedures performed in operating theatres run by Médecins Sans Frontières-Operations Centre Brussels (MSF-OCB) from July 2008 through June 2014 were reviewed. Surgical specialist missions were excluded. Burn procedures were quantified, related to demographics and reason for humanitarian response, and described. A total of 96,239 operations were performed at 27 MSF-OCB projects in 15 countries between 2008 and 2014. Of the 33,947 general surgical operations, 4,280 (11%) were for burns. This proportion steadily increased from 3% in 2008 to 24% in 2014. People receiving surgical care from conflict relief missions had nearly twice the odds of having a burn operation compared with people requiring surgery in communities affected by natural disaster (adjusted odds ratio, 1.94; 95% confidence interval, 1.46-2.58). Nearly 70% of burn procedures were planned serial visits to the theatre. A diverse skill set was required. Unmet humanitarian assistance needs increased US$400 million dollars in 2013 in the face of an increasing number of individuals affected by crisis and a growing surgical burden. Given the high volume of burn procedures performed at MSF-OCB projects and the resource intensive nature of burn management, requisite planning and reliable funding are necessary to ensure quality for burn care in humanitarian settings.

[Work organisation improvement methods applied to activities of Blood Transfusion Establishments (BTE): Lean Manufacturing, VSM, 5S].

PubMed

Bertholey, F; Bourniquel, P; Rivery, E; Coudurier, N; Follea, G

2009-05-01

Continuous improvement of efficiency as well as new expectations from customers (quality and safety of blood products) and employees (working conditions) imply constant efforts in Blood Transfusion Establishments (BTE) to improve work organisations. The Lean method (from "Lean" meaning "thin") aims at identifying wastages in the process (overproduction, waiting, over-processing, inventory, transport, motion) and then reducing them in establishing a mapping of value chain (Value Stream Mapping). It consists in determining the added value of each step of the process from a customer perspective. Lean also consists in standardizing operations while implicating and responsabilizing all collaborators. The name 5S comes from the first letter of five operations of a Japanese management technique: to clear, rank, keep clean, standardize, make durable. The 5S method leads to develop the team working inducing an evolution of the way in the management is performed. The Lean VSM method has been applied to blood processing (component laboratory) in the Pays de la Loire BTE. The Lean 5S method has been applied to blood processing, quality control, purchasing, warehouse, human resources and quality assurance in the Rhône-Alpes BTE. The experience returns from both BTE shows that these methods allowed improving: (1) the processes and working conditions from a quality perspective, (2) the staff satisfaction, (3) the efficiency. These experiences, implemented in two BTE for different processes, confirm the applicability and usefulness of these methods to improve working organisations in BTE.

The use of Lean and Six Sigma methodologies in surgery: a systematic review.

PubMed

Mason, S E; Nicolay, C R; Darzi, A

2015-04-01

Lean and Six Sigma are improvement methodologies developed in the manufacturing industry and have been applied to healthcare settings since the 1990 s. They use a systematic and reproducible approach to provide Quality Improvement (QI), with a flexible process that can be applied to a range of outcomes across different patient groups. This review assesses the literature with regard to the use and utility of Lean and Six Sigma methodologies in surgery. MEDLINE, Embase, PsycINFO, Allied and Complementary Medicine Database, British Nursing Index, Cumulative Index to Nursing and Allied Health Literature, Health Business Elite and the Health Management Information Consortium were searched in January 2014. Experimental studies were included if they assessed the use of Lean or Six Sigma on the ability to improve specified outcomes in surgical patients. Of the 124 studies returned, 23 were suitable for inclusion with 11 assessing Lean, 6 Six Sigma and 6 Lean Six Sigma. The broad range of outcomes can be collated into six common aims: to optimise outpatient efficiency, to improve operating theatre efficiency, to decrease operative complications, to reduce ward-based harms, to reduce mortality and to limit unnecessary cost and length of stay. The majority of studies (88%) demonstrate improvement; however high levels of systematic bias and imprecision were evident. Lean and Six Sigma QI methodologies have the potential to produce clinically significant improvement for surgical patients. However there is a need to conduct high-quality studies with low risk of systematic bias in order to further understand their role. Copyright © 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Does lean muddy the quality improvement waters? A qualitative study of how a hospital management team understands lean in the context of quality improvement.

PubMed

Savage, Carl; Parke, Louise; von Knorring, Mia; Mazzocato, Pamela

2016-10-19

Health care has experimented with many different quality improvement (QI) approaches with greater variation in name than content. This has been dubbed pseudoinnovation. However, it could also be that the subtleties and differences are not clearly understood. To explore this further, the purpose of this study was to explore how hospital managers perceive lean in the context of QI. We used a qualitative study design with semi-structured interviews to explore twelve top managers' perceptions of the relationship between lean and quality improvement (QI) at a university-affiliated hospital. Managers described that QI and lean shared the same overall purpose: focus on patient needs and improve efficiency and effectiveness. Employee involvement was emphasized in both strategies, as well as the support offered by managers of staff initiatives. QI was perceived as a strategy that could support structural changes at the organizational level whereas lean was seen as applicable at the operational level. Moreover, lean carried a negative connotation, lacked the credibility of QI, and was perceived as a management fad. Aspects of QI and lean were misunderstood. In a context where lean remains an abstract term, and staff associate lean with automotive applications and cost reduction, it may be fruitful for managers to invest time and resources to develop a strategy for continual improvement and utilize vocabulary that resonates with health care staff. This could reduce the risk that improvement efforts are rejected out of hand.

Orion Burn Management, Nominal and Response to Failures

NASA Technical Reports Server (NTRS)

Odegard, Ryan; Goodman, John L.; Barrett, Charles P.; Pohlkamp, Kara; Robinson, Shane

2016-01-01

An approach for managing Orion on-orbit burn execution is described for nominal and failure response scenarios. The burn management strategy for Orion takes into account per-burn variations in targeting, timing, and execution; crew and ground operator intervention and overrides; defined burn failure triggers and responses; and corresponding on-board software sequencing functionality. Burn-to- burn variations are managed through the identification of specific parameters that may be updated for each progressive burn. Failure triggers and automatic responses during the burn timeframe are defined to provide safety for the crew in the case of vehicle failures, along with override capabilities to ensure operational control of the vehicle. On-board sequencing software provides the timeline coordination for performing the required activities related to targeting, burn execution, and responding to burn failures.

Gas turbine topping combustor

DOEpatents

Beer, J.; Dowdy, T.E.; Bachovchin, D.M.

1997-06-10

A combustor is described for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone. 14 figs.

Assessment of Reduced-Kinetics Mechanisms for Combustion of Jet Fuel in CFD Applications

NASA Technical Reports Server (NTRS)

Ajmani, Kumud; Kundu, Krihna P.; Yungster, Shaye J.

2014-01-01

A computational effort was undertaken to analyze the details of fluid flow in Lean-Direct Injection (LDI) combustors for next-generation LDI design. The National Combustor Code (NCC) was used to perform reacting flow computations on single-element LDI injector configurations. The feasibility of using a reduced chemical-kinetics approach, which optimizes the reaction rates and species to model the emissions characteristics typical of lean-burning gas-turbine combustors, was assessed. The assessments were performed with Reynolds- Averaged Navier-Stokes (RANS) and Time-Filtered Navier Stokes (TFNS) time-integration, with a Lagrangian spray model with the NCC code. The NCC predictions for EINOx and combustor exit temperature were compared with experimental data for two different single-element LDI injector configurations, with 60deg and 45deg axially swept swirler vanes. The effects of turbulence-chemistry interaction on the predicted flow in a typical LDI combustor were studied with detailed comparisons of NCC TFNS with experimental data.

Identification and Validation of Established and Novel Biomarkers for Infections in Burns

DTIC Science & Technology

2015-10-01

W81XWH-15-1-0143 (PI: Branski, Ludwik ) 07/01/15-06/30/19 5% Dept of Defense $384,660 " Growth Hormone Therapy for Muscle Regeneration...recombinant human growth hormone (rhGH) supplementation on body composition, such as lean body mass loss and bone mineral content, and to assess if...of 34 ***New award on 7/1/2015.*** W81XWH-15-1-0143 (PI: Branski, Ludwik ) 07/01/15-06/30/19 1% Dept of Defense $384,660 " Growth Hormone

Catalysts for lean burn engine exhaust abatement

DOEpatents

Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

2006-08-01

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Catalysts For Lean Burn Engine Exhaust Abatement

DOEpatents

Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

2004-04-06

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Catalysts for lean burn engine exhaust abatement

DOEpatents

Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

2003-01-01

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Piloted rich-catalytic lean-burn hybrid combustor

DOEpatents

Newburry, Donald Maurice

2002-01-01

A catalytic combustor assembly which includes, an air source, a fuel delivery means, a catalytic reactor assembly, a mixing chamber, and a means for igniting a fuel/air mixture. The catalytic reactor assembly is in fluid communication with the air source and fuel delivery means and has a fuel/air plenum which is coated with a catalytic material. The fuel/air plenum has cooling air conduits passing therethrough which have an upstream end. The upstream end of the cooling conduits is in fluid communication with the air source but not the fuel delivery means.

The effect of a Lean quality improvement implementation program on surgical pathology specimen accessioning and gross preparation error frequency.

PubMed

Smith, Maxwell L; Wilkerson, Trent; Grzybicki, Dana M; Raab, Stephen S

2012-09-01

Few reports have documented the effectiveness of Lean quality improvement in changing anatomic pathology patient safety. We used Lean methods of education; hoshin kanri goal setting and culture change; kaizen events; observation of work activities, hand-offs, and pathways; A3-problem solving, metric development, and measurement; and frontline work redesign in the accessioning and gross examination areas of an anatomic pathology laboratory. We compared the pre- and post-Lean implementation proportion of near-miss events and changes made in specific work processes. In the implementation phase, we documented 29 individual A3-root cause analyses. The pre- and postimplementation proportions of process- and operator-dependent near-miss events were 5.5 and 1.8 (P < .002) and 0.6 and 0.6, respectively. We conclude that through culture change and implementation of specific work process changes, Lean implementation may improve pathology patient safety.

Are Agile and Lean Manufacturing Systems Employing Sustainability, Complexity and Organizational Learning?

ERIC Educational Resources Information Center

Flumerfelt, Shannon; Siriban-Manalang, Anna Bella; Kahlen, Franz-Josef

2012-01-01

Purpose: This paper aims to peruse theories and practices of agile and lean manufacturing systems to determine whether they employ sustainability, complexity and organizational learning. Design/methodology/approach: The critical review of the comparative operational similarities and difference of the two systems was conducted while the new views…

The Formal Representation of Administrative and Operational Relationships within Defense Organizational Constructs

DTIC Science & Technology

2006-06-01

of the 10th International Command and Control Research and Technology Symposium; Ritz - Carlton Hotel , McLean, VA; 13-16 June 2005. See: http...International Command and Control Research and Technology Symposium; Ritz - Carlton Hotel , McLean, VA; 13-16 June 2005. http://www.dodccrp.org/events/2005

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

DOE PAGES

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James; ...

2017-03-28

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

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

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

Process Improvement at the Aircraft Intermediate Maintenance Detachment (AIMD) at Naval Air Station Whidbey Island

DTIC Science & Technology

2006-12-01

the goal of achieving zero waste is impractical. Thus, the concept of Lean has to be slightly modified to adjust for the uncertainty and variability...personnel are qualified as Black or Green belts, this may become an issue for them down the road. 2. Criticism Two The goal of Lean is to achieve “ Zero ... Waste ,” therefore, how can the military achieve Lean in such a vast area of uncertainty and variability? Under the environment that DoD operates in

REVIEW ARTICLE: Emission measurement techniques for advanced powertrains

NASA Astrophysics Data System (ADS)

Adachi, Masayuki

2000-10-01

Recent developments in high-efficiency low-emission powertrains require the emission measurement technologies to be able to detect regulated and unregulated compounds with very high sensitivity and a fast response. For example, levels of a variety of nitrogen compounds and sulphur compounds should be analysed in real time in order to develop aftertreatment systems to decrease emission of NOx for the lean burning powertrains. Also, real-time information on the emission of particulate matter for the transient operation of diesel engines and direct injection gasoline engines is invaluable. The present paper reviews newly introduced instrumentation for such emission measurement that is demanded for the developments in advanced powertrain systems. They include Fourier transform infrared spectroscopy, mass spectrometry and fast response flame ionization detection. In addition, demands and applications of the fuel reformer developments for fuel cell electric vehicles are discussed. Besides the detection methodologies, sample handling techniques for the measurement of concentrations emitted from low emission vehicles for which the concentrations of the pollutants are significantly lower than the concentrations present in ambient air, are also described.

Combustion efficiency determined from wall pressure and temperature measurement in a Mach 2 combustor

NASA Technical Reports Server (NTRS)

Segal, Corin; Mcdaniel, James C.; Whitehurst, Robert B.; Krauss, Roland H.

1991-01-01

A study of transverse hydrogen injection behind a rearward facing step in a Mach 2 airflow was conducted to determine the combustion efficiency and the combustor/inlet interactions at the low temperature lean-mixture operational end of a scramjet combustor model. The fuel was injected at sonic conditions into the electrically heated airstream, which was maintained at 850 K or below. The static pressure delivered at the entrance of the combustor ranged between 0.25 to 0.5 atm. Injector configurations included single and staged injectors placed at 3 or 3-and-7 step-heights downstream of the step, respectively, with injector diameters of 1, 1.5, and 2 mm. Ignition was achieved by initially unstarting the test section. The constant area combustor and the low initial temperatures caused thermal choking and upstream interaction to occur at very low equivalence ratios. Typically, most of the fuel was burned in the recirculation region behind the step and around the jets. The effects of initial conditions (temperature and pressure), fuel-to-air dynamic pressure ratio, and boundaries (thermal vs adiabatic) are presented.

The efficacy and safety of oxandrolone treatment for patients with severe burns: A systematic review and meta-analysis.

PubMed

Li, Hui; Guo, Yinan; Yang, Zhenyu; Roy, Mridul; Guo, Qulian

2016-06-01

The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of using oxandrolone in patients with severe burns. PubMed, Medline, Ovid, Cochrane Library, Elsevier Science, ProQuest, and Springer Link databases were searched. Randomized trials were included, and clinically important measures were selected. The outcomes were pooled with Revman 5.2. Other outcomes that could not be pooled were described in detail. Finally, 15 randomized controlled trials (RCTs) were identified for analysis in this review, including 806 participants. 1. Mortality, infection, and hepatic function: Oxandrolone therapy did not affect mortality (relative risk (RR)=0.85, 95% confidence interval (CI)=(0.38, 1.89), P=0.69) or infection (RR=0.87, (0.69, 1.11), P=0.26). The two groups (oxandrolone group vs. control group) showed no significant difference in liver dysfunction (RR=1.15, (0.83, 1.59), P=0.41). All the 15 RCTs reported no incidence of hepatic insufficiency in controls or treatment groups. 2. In the catabolic phase: Treatment with oxandrolone shortened length of stay by 3.02 (2.37, 3.66) days, donor-site healing time by 4.41 (3.41, 5.41) days, the time between surgical procedures by 0.63 (0.11, 1.16) days, as well as reduced weight loss by 5 (3.70, 6.30) kg and nitrogen loss by 8.19 (6.87, 9.52) g/day, with all P<0.00001. 3. In the rehabilitative phase: Treatment with oxandrolone shortened the length of stay to 6.45 (4.20, 8.69) days, as well as decreased weight loss by 0.86 (0.76, 0.96) kg/week and reduction of lean body mass by 5% (3.34, 6.66), with all P<0.00001. 4. Long-term parameters: Oxandrolone treatment led to an additional gain in lean body mass of 3.99% (3.08, 4.89) after 6 months and 10.78% (9.92, 11.64) after 12 months in patients with severe burns, with all P<0.00001. The treatment of severe burns with oxandrolone is significantly effective without obvious side effects. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

The positive impact of simultaneous implementation of the BD FocalPoint GS Imaging System and lean principles on the operation of gynecologic cytology.

PubMed

Wong, Rebecca; Levi, Angelique W; Harigopal, Malini; Schofield, Kevin; Chhieng, David C

2012-02-01

Our cytology laboratory, like many others, is under pressure to improve quality and provide test results faster while decreasing costs. We sought to address these issues by introducing new technology and lean principles. To determine the combined impact of the FocalPoint Guided Screener (GS) Imaging System (BD Diagnostics-TriPath, Burlington, North Carolina) and lean manufacturing principles on the turnaround time (TAT) and productivity of the gynecologic cytology operation. We established a baseline measure of the TAT for Papanicolaou tests. We then compared that to the performance after implementing the FocalPoint GS Imaging System and lean principles. The latter included value-stream mapping, workflow modification, and a first in-first out policy. The mean (SD) TAT for Papanicolaou tests before and after the implementation of FocalPoint GS Imaging System and lean principles was 4.38 (1.28) days and 3.20 (1.32) days, respectively. This represented a 27% improvement in the average TAT, which was statistically significant (P < .001). In addition, the productivity of staff improved 17%, as evidenced by the increase in slides screened from 8.85/h to 10.38/h. The false-negative fraction decreased from 1.4% to 0.9%, representing a 36% improvement. In our laboratory, the implementation of FocalPoint GS Imaging System in conjunction with lean principles resulted in a significant decrease in the average TAT for Papanicolaou tests and a substantial increase in the productivity of cytotechnologists while maintaining the diagnostic quality of gynecologic cytology.

Low NOx heavy fuel combustor concept program, phase 1

NASA Technical Reports Server (NTRS)

Cutrone, M. B.

1981-01-01

Combustion tests were completed with seven concepts, including three rich/lean concepts, three lean/lean concepts, and one catalytic combustor concept. Testing was conducted with ERBS petroleum distillate, petroleum residual, and SRC-II coal-derived liquid fuels over a range of operating conditions for the 12:1 pressure ratio General Electric MS7001E heavy-duty turbine. Blends of ERBS and SRC-II fuels were used to vary fuel properties over a wide range. In addition, pyridine was added to the ERBS and residual fuels to vary nitrogen level while holding other fuel properties constant. Test results indicate that low levels of NOx and fuel-bound nitrogen conversion can be achieved with the rich/lean combustor concepts for fuels with nitrogen contents up to 1.0% by weight. Multinozzle rich/lean Concept 2 demonstrated dry low Nox emissions within 10-15% of the EPA New Source Performance Standards goals for SRC-II fuel, with yields of approximately 15%, while meeting program goals for combustion efficiency, pressure drop, and exhaust gas temperature profile. Similar, if not superior, potential was demonstrated by Concept 3, which is a promising rich/lean combustor design.

Lean in healthcare: the unfilled promise?

PubMed

Radnor, Zoe J; Holweg, Matthias; Waring, Justin

2012-02-01

In an effort to improve operational efficiency, healthcare services around the world have adopted process improvement methodologies from the manufacturing sector, such as Lean Production. In this paper we report on four multi-level case studies of the implementation of Lean in the English NHS. Our results show that this generally involves the application of specific Lean 'tools', such as 'kaizen blitz' and 'rapid improvement events', which tend to produce small-scale and localised productivity gains. Although this suggests that Lean might not currently deliver the efficiency improvements desired in policy, the evolution of Lean in the manufacturing sector also reveals this initial focus on the 'tool level'. In moving to a more system-wide approach, however, we identify significant contextual differences between healthcare and manufacturing that result in two critical breaches of the assumptions behind Lean. First, the customer and commissioner in the private sector are the one and the same, which is essential in determining 'customer value' that drives process improvement activities. Second, healthcare is predominantly designed to be capacity-led, and hence there is limited ability to influence demand or make full use of freed-up resources. What is different about this research is that these breaches can be regarded as not being primarily 'professional' in origin but actually more 'organisational' and 'managerial' and, if not addressed could severely constrain Lean's impact on healthcare productivity at the systems level. Copyright © 2011 Elsevier Ltd. All rights reserved.

Calculation of Glucose Dose for Intraperitoneal Glucose Tolerance Tests in Lean and Obese Mice.

PubMed

Jørgensen, Mikkel S; Tornqvist, Kristina S; Hvid, Henning

2017-01-01

Glucose tolerance tests are used frequently in nonclinical research with laboratory animals, for example during characterization of obese phenotypes. Despite published standard operating procedures for glucose tolerance tests in rodents, how glucose doses should be calculated when obese and lean animals are compared is not well documented. Typically the glucose dose is calculated as 2 g/kg body weight, regardless of body composition. With this approach, obese mice receive larger glucose doses than do lean animals, potentially leading to overestimation of glucose intolerance in obese animals. In this study, we performed intraperitoneal glucose tolerance tests in mice with diet-induced obesity and their lean controls, with glucose doses based on either the total body weight or the lean body mass of the animals. To determine glucose tolerance, we determined the blood glucose AUC during the glucose tolerance test. We found that the blood glucose AUC was increased significantly in obese mice compared with lean mice by 75% on average when glucose was dosed according to the lean body mass and by 87% when the glucose dose was calculated according to total body weight. Therefore, mice with diet-induced obesity were approximately equally glucose intolerant between the 2 dose-calculation protocols. However, we recommend calculating the glucose dose according to the lean body mass of the mice, because doing so eliminates the concern regarding overdosing of obese animals.

Developing a lean culture in the laboratory.

PubMed

Napoles, Leyda; Quintana, Maria

2006-07-25

The Director of Pathology at Jackson Memorial Hospital was interested in improving the operational efficiencies of the department in order to enhance the department's level of service in conjunction with the expansion of the overall health system. The decision was made to implement proven Lean practices in the laboratory under the direction of a major consulting firm. This article details the scope of the initial project as well as the operating principles of Lean manufacturing practices as applied to the clinical laboratory. The goals of the project were to improve turnaround times of laboratory results, reduce inventory and supply costs, improve staff productivity, maximize workflow, and eliminate waste. Extensive data gathering and analysis guided the work process by highlighting the areas of highest opportunity. This systematic approach resulted in recommendations for the workflow and physical layout of the laboratory. It also included the introduction of "standard workflow" and "visual controls" as critical items that streamlined operational efficiencies. The authors provide actual photographs and schematics of the reorganization and improvements to the physical layout of the laboratory. In conclusion, this project resulted in decreased turnaround times and increased productivity, as well as significant savings in the overall laboratory operations.

Emissions from Open Burning of Simulated Military Waste from Forward Operating Bases

EPA Science Inventory

Emissions from open burning of simulated military waste from forward operating bases (FOBs) were extensively characterized as an initial step in assessing potential inhalation exposure of FOB personnel and future disposal alternatives. Emissions from two different burning scenar...

An integrated lean-methods approach to hospital facilities redesign.

PubMed

Nicholas, John

2012-01-01

Lean production methods for eliminating waste and improving processes in manufacturing are now being applied in healthcare. As the author shows, the methods are appropriate for redesigning hospital facilities. When used in an integrated manner and employing teams of mostly clinicians, the methods produce facility designs that are custom-fit to patient needs and caregiver work processes, and reduce operational costs. The author reviews lean methods and an approach for integrating them in the redesign of hospital facilities. A case example of the redesign of an emergency department shows the feasibility and benefits of the approach.

[Research on the Application of Lean Management in Medical Consumables Material Logistics Management].

PubMed

Yang, Chai; Zhang, Wei; Gu, Wei; Shen, Aizong

2016-11-01

Solve the problems of high cost, low utilization rate of resources, low medical care quality problem in medical consumables material logistics management for scientific of medical consumables management. Analysis of the problems existing in the domestic medical consumables material logistics management in hospital, based on lean management method, SPD(Supply, Processing, Distribution) for specific applications, combined HBOS(Hospital Business Operation System), HIS (Hospital Information System) system for medical consumables material management. Achieve the lean management in medical consumables material purchase, warehouse construction, push, clinical use and retrospect. Lean management in medical consumables material can effectively control the cost in logistics management, optimize the alocation of resources, liberate unnecessary time of medical staff, improve the quality of medical care. It is a scientific management method.

30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

Lean healthcare from a change management perspective.

PubMed

van Rossum, Lisa; Aij, Kjeld Harald; Simons, Frederique Elisabeth; van der Eng, Niels; Ten Have, Wouter Dirk

2016-05-16

Purpose - Lean healthcare is used in a growing number of hospitals to increase efficiency and quality of care. However, healthcare organizations encounter problems with the implementation of change initiatives due to an implementation gap: the gap between strategy and execution. From a change management perspective, the purpose of this paper is to increase scientific knowledge regarding factors that diminish the implementation gap and make the transition from the "toolbox lean" toward an actual transformation to lean healthcare. Design/methodology/approach - A cross-sectional study was executed in an operating theatre of a Dutch University Medical Centre. Transformational leadership was expected to ensure the required top-down commitment, whereas team leadership creates the required active, bottom-up behavior of employees. Furthermore, professional and functional silos and a hierarchical structure were expected to impede the workforce flexibility in adapting organizational elements and optimize the entire process flow. Findings - The correlation and regression analyses showed positive relations between the transformational leadership and team leadership styles and lean healthcare implementation. The results also indicated a strong relation between workforce flexibility and the implementation of lean healthcare. Originality/value - With the use of a recently developed change management model, the Change Competence Model, the authors suggest leadership and workforce flexibility to be part of an organization's change capacity as crucial success factor for a sustainable transformation to lean healthcare.

Quick-Mixing Studies Under Reacting Conditions

NASA Technical Reports Server (NTRS)

Leong, May Y.; Samuelsen, G. S.

1996-01-01

The low-NO(x) emitting potential of rich-burn/quick-mix/lean-burn )RQL) combustion makes it an attractive option for engines of future stratospheric aircraft. Because NO(x) formation is exponentially dependent on temperature, the success of the RQL combustor depends on minimizing high temperature stoichiometric pocket formation in the quick-mixing section. An experiment was designed and built, and tests were performed to characterize reaction and mixing properties of jets issuing from round orifices into a hot, fuel-rich crossflow confined in a cylindrical duct. The reactor operates on propane and presents a uniform, non-swirling mixture to the mixing modules. Modules consisting of round orifice configurations of 8, 9, 10, 12, 14, and 18 holes were evaluated at a momentum-flux ratio of 57 and jet-to-mainstream mass-flaw ratio of 2.5. Temperatures and concentrations of O2, CO2, CO, HC, and NO(x) were obtained upstream, down-stream, and within the orifice plane to determine jet penetration as well as reaction processes. Jet penetration was a function of the number of orifices and affected the mixing in the reacting system. Of the six configurations tested, the 14-hole module produced jet penetration close to the module half-radius and yielded the best mixing and most complete combustion at a plane one duct diameter from the orifice leading edge. The results reveal that substantial reaction and heat release occur in the jet mixing zone when the entering effluent is hot and rich, and that the experiment as designed will serve to explore satisfactorily jet mixing behavior under realistic reacting conditions in future studies.

Gaseous Emissions Results from a Three-Cup Flametube Test of a Third-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

NASA Technical Reports Server (NTRS)

Tacina, Kathleen M.; Podboy, Derek P.; Lee, Phil; Dam, Bidhan

2017-01-01

This paper summarizes the development of lean direct injection (LDI) combustor technology at, or in collaboration with, the NASA Glenn Research Center. These configurations differ mainly in fuel-air mixing strategy. The paper reviews the NOx performance and operability characteristics of multiple LDI configurations tested at NASA Glenn.

Lean Management—The Journey from Toyota to Healthcare

PubMed Central

Teich, Sorin T.; Faddoul, Fady F.

2013-01-01

The evolution of production systems is tightly linked to the story of Toyota Motor Company (TMC) that has its roots around 1918. The term “lean” was coined in 1990 following the exploration of the Toyota model that led to the “transference” thesis sustaining the concept that manufacturing problems and technologies are universal problems faced by management and that these concepts can be emulated in non-Japanese enterprises. Lean is a multi-faceted concept and requires organizations to exert effort along several dimensions simultaneously; some consider a successful implementation either achieving major strategic components of lean, implementing practices to support operational aspects, or providing evidence that the improvements are sustainable in the long term. The article explores challenges and opportunities faced by organizations that intend incorporating lean management principles and presents the specific context of the healthcare industry. Finally, the concepts of “essential few” and customer value are illustrated through a simple example of process change following lean principles, which was implemented in a dental school in the United States. PMID:23908857

Lean Production as an Innovative Approach to Construction

NASA Astrophysics Data System (ADS)

Spišáková, Marcela; Kozlovská, Mária

2013-06-01

Lean production presents a new approach to the construction management which has enabled enterprises to attain very high levels of efficiency, competitiveness and flexibility in production systems. Nowadays, a number of industrial processes are managed in accordance with these advanced management principles [1]. The principles of lean production are applied within the integrated design and delivery solutions (IDDS) and prefabricated construction. IDDS uses collaborative work processes and enhanced skills, with integrated data, information, and knowledge management to minimize structural and process inefficiencies and to enhance the value delivered during design, build, and operation, and across projects. Prefabrication presents a one of opportunities for construction methods, which allows the compliance with principles of sustainable design, provides the potential benefits such as faster construction, fewer housing defects, reduction in energy use and waste and elimination of environmental and safety risks. This paper presents the lean production within the IDDS and its potential in the modern prefabrication. There is created a field providing of benefits of lean production in construction industry.

Impact of a Newly Implemented Burn Protocol on Surgically Managed Partial Thickness Burns at a Specialized Burns Center in Singapore.

PubMed

Tay, Khwee-Soon Vincent; Chong, Si-Jack; Tan, Bien-Keem

2016-03-01

This study evaluated the impact of a newly implemented protocol for superficial to mid-dermal partial thickness burns which involves early surgery and rapid coverage with biosynthetic dressing in a specialized national burns center in Singapore. Consecutive patients with 5% or greater total body surface area (TBSA) superficial to mid-dermal partial thickness burns injury admitted to the Burns Centre at the Singapore General Hospital between August and December 2014 for surgery within 48 hours of injury were prospectively recruited into the study to form the protocol group. Comparable historical cases from the year 2013 retrieved from the burns center audit database were used to form the historical control group. Demographics (age, sex), type and depth of burns, %TBSA burnt, number of operative sessions, and length of stay were recorded for each patient of both cohorts. Thirty-nine burns patients managed under the new protocol were compared with historical control (n = 39) comparable in age and extensiveness of burns. A significantly shorter length of stay (P < 0.05) per TBSA burns was observed in the new protocol group (0.74 day/%TBSA) versus historical control (1.55 day/%TBSA). Fewer operative sessions were needed under the new protocol for burns 10% or greater TBSA burns (P < 0.05). The authors report their promising experience with a newly implemented protocol for surgically managed burns patients which involves early surgery and appropriate use of biosynthetic dressing on superficial to mid-dermal partial thickness burns. Clinically, shorter lengths of stay, fewer operative sessions, and decreased need for skin grafting of burns patient were observed.

Lean healthcare in developing countries: evidence from Brazilian hospitals.

PubMed

Costa, Luana Bonome Message; Filho, Moacir Godinho; Rentes, Antonio Freitas; Bertani, Thiago Moreno; Mardegan, Ronaldo

2017-01-01

The present study evaluates how five sectors of two Brazilian hospitals have implemented lean healthcare concepts in their operations. The main characteristics of the implementation process are analyzed in the present study: the motivational factor for implementation, implementation time, form (consultancy or internal), team (hospital and consultants), lean implementation continuity/sustainability, lean healthcare tools and methods implemented, problems/improvement opportunities, lean healthcare barriers faced during the implementation process, and critical factors that affected the implementation and the results obtained in each case. The case studies indicate that reducing patient lead times and costs and making financial improvements were the primary factors that motivated lean healthcare implementation in the hospitals studied. Several tools and methods were used in the cases studied, especially value stream mapping and DMAIC. The barriers found in both hospitals are primarily associated with the human factor. Additionally, the results obtained after implementation were analyzed and improvements in financial aspects, productivity and capacity, and lead time reduction of the analyzed sectors were observed. Further, this study also exhibited four propositions elaborated from the results obtained from the cases that highlighted barriers and challenges to lean healthcare implementation in developing countries. Two of these barriers are hospital organizational structure (and, consequently, how the senior management works with medical staff), and outsourcing hospital activities. This study also concluded that the initialization and maintenance of lean healthcare implementation rely heavily on external support because lean healthcare subject knowledge is not yet available in the healthcare organization, which represents a challenge. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Burn injury care for Special Forces and far-forward deployed troops.

PubMed

Brown, Tim La H; Skinner, Adrian M

2005-11-01

Special Forces are at risk of serious burn injury. We have suggested standard operating procedures for burn injury management in a constrained environment, with novel uses of operational kit components for trauma care. In addition, we propose instruction in basic skills of escharotomy for forward troops.

Epidemiology of pediatric burns in southwest China from 2011 to 2015.

PubMed

Li, Haisheng; Wang, Song; Tan, Jianglin; Zhou, Junyi; Wu, Jun; Luo, Gaoxing

2017-09-01

Burns are a major form of injury in children worldwide. This study aimed to investigate the epidemiology, outcome, cost and risk factors of pediatric burns in southwest China. This retrospective study was performed at the Institute of Burn Research of the Third Military Medical University from 2011 to 2015. Data, including demographic, injury-related, and clinical data and patient outcome, were collected from medical records. A total of 2478 children with burns (58.03% boys), accounting for 39.2% of total burn patients, were included. The average age of the burn patients was 2.86±2.86years, and most patients (85.55%) were under five years old. The incidence of burns peaked in January, February and May. Scald burns were the most frequent (79.06%), followed by flame burns (14.0%) and electrical burns (3.35%). Limbs were the most common burn sites (69.73%), and the average total body surface area (TBSA) was 11.57±11.61%. The percentage of children who underwent operations and the number of operations were significantly increased in cases of electrical burns, the older-age group, a larger TBSA and full-thickness burns. Six deaths were recorded, yielding a mortality of 0.24%. The median length of stay and cost were 14days and 9541 CNY, respectively, and the major risk factors for length of stay and cost were the TBSA, number of operations, full-thickness burns and outcome. In southwest China, among children under five years old, scald and flame burns should become the key prevention target, and future prevention strategies should be based on related risk factors. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

Impact of stress-induced diabetes on outcomes in severely burned children.

PubMed

Finnerty, Celeste C; Ali, Arham; McLean, Josef; Benjamin, Nicole; Clayton, Robert P; Andersen, Clark R; Mlcak, Ronald P; Suman, Oscar E; Meyer, Walter; Herndon, David N

2014-04-01

Post-burn hyperglycemia leads to graft failure, multiple organ failure, and death. A hyperinsulinemic-euglycemic clamp is used to keep serum glucose between 60 and 110 mg/dL. Because of frequent hypoglycemic episodes, a less-stringent sliding scale insulin protocol is used to maintain serum glucose levels between 80 and 160 mg/dL after elevations >180 mg/dL. We randomized pediatric patients with massive burns into 2 groups, patients receiving sliding scale insulin to lower blood glucose levels (n = 145) and those receiving no insulin (n = 98), to determine the differences in morbidity and mortality. Patients 0 to 18 years old with burns covering ≥ 30% of the total body surface area and not randomized to receive anabolic agents were included in this study. End points included glucose levels, infections, resting energy expenditure, lean body mass, bone mineral content, fat mass, muscle strength, and serum inflammatory cytokines, hormones, and liver enzymes. Maximal glucose levels occurred within 6 days of burn injury. Blood glucose levels were age dependent, with older children requiring more insulin (p < 0.05). Daily maximum and daily minimum, but not 6 am, glucose levels were significantly different based on treatment group (p < 0.05). Insulin significantly increased resting energy expenditure and improved bone mineral content (p < 0.05). Each additional wound infection increased incidence of hyperglycemia (p = 0.004). There was no mortality in patients not receiving insulin, only in patients who received insulin (p < 0.004). Muscle strength was increased in patients receiving insulin (p < 0.05). Burn-induced hyperglycemia develops in a subset of severely burned children. Length of stay was reduced in the no insulin group, and there were no deaths in this group. Administration of insulin positively impacted bone mineral content and muscle strength, but increased resting energy expenditure, hypoglycemic episodes, and mortality. New glucose-lowering strategies might be needed. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

40 CFR 60.2974 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2014 CFR

2014-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.2974 Am I required to apply for and obtain a title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber...

40 CFR 60.2974 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2013 CFR

2013-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.2974 Am I required to apply for and obtain a title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber...

40 CFR 49.9869 - Permits to operate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... TRIBAL CLEAN AIR ACT AUTHORITY Implementation Plans for Tribes-Region X Implementation Plan for the Burns Paiute Tribe of the Burns Paiute Indian Colony of Oregon § 49.9869 Permits to operate. Permits to operate...

Lead-time reduction utilizing lean tools applied to healthcare: the inpatient pharmacy at a local hospital.

PubMed

Al-Araidah, Omar; Momani, Amer; Khasawneh, Mohammad; Momani, Mohammed

2010-01-01

The healthcare arena, much like the manufacturing industry, benefits from many aspects of the Toyota lean principles. Lean thinking contributes to reducing or eliminating nonvalue-added time, money, and energy in healthcare. In this paper, we apply selected principles of lean management aiming at reducing the wasted time associated with drug dispensing at an inpatient pharmacy at a local hospital. Thorough investigation of the drug dispensing process revealed unnecessary complexities that contribute to delays in delivering medications to patients. We utilize DMAIC (Define, Measure, Analyze, Improve, Control) and 5S (Sort, Set-in-order, Shine, Standardize, Sustain) principles to identify and reduce wastes that contribute to increasing the lead-time in healthcare operations at the pharmacy understudy. The results obtained from the study revealed potential savings of > 45% in the drug dispensing cycle time.

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.

Emissions from open burning of simulated military waste from forward operating bases.

PubMed

Aurell, Johanna; Gullett, Brian K; Yamamoto, Dirk

2012-10-16

Emissions from open burning of simulated military waste from forward operating bases (FOBs) were extensively characterized as an initial step in assessing potential inhalation exposure of FOB personnel and future disposal alternatives. Emissions from two different burning scenarios, so-called "burn piles/pits" and an air curtain burner/"burn box", were compared using simulated FOB waste from municipal and commercial sources. A comprehensive array of emissions was quantified, including CO(2), PM(2.5), volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins and -furans (PCDDs/PCDFs), polybrominated dibenzodioxins and -furans (PBDDs/PBDFs), and metals. In general, smoldering conditions in the burn box and the burn pile led to similar emissions. However, when the burn box underwent periodic waste charging to maintain sustained combustion, PM(2.5), VOCs, and PAH emissions dropped considerably compared to smoldering conditions and the overall burn pile results. The PCDD/PCDF and PBDD/PBDF emission factors for the burn piles were 50 times higher than those from the burn box likely due to the dominance of smoldering combustion in the burn piles.

Effect of blood transfusion on outcome after major burn injury: a multicenter study.

PubMed

Palmieri, Tina L; Caruso, Daniel M; Foster, Kevin N; Cairns, Bruce A; Peck, Michael D; Gamelli, Richard L; Mozingo, David W; Kagan, Richard J; Wahl, Wendy; Kemalyan, Nathan A; Fish, Joel S; Gomez, Manuel; Sheridan, Robert L; Faucher, Lee D; Latenser, Barbara A; Gibran, Nicole S; Klein, Robert L; Solem, Lynn D; Saffle, Jeffrey R; Morris, Stephen E; Jeng, James C; Voigt, David; Howard, Pamela A; Molitor, Fred; Greenhalgh, David G

2006-06-01

To delineate blood transfusion practices and outcomes in patients with major burn injury. Patients with major burn injury frequently require multiple blood transfusions; however, the effect of blood transfusion after major burn injury has had limited study. Multicenter retrospective cohort analysis. Regional burn centers throughout the United States and Canada. Patients admitted to a participating burn center from January 1 through December 31, 2002, with acute burn injuries of >or=20% total body surface area. Outcome measurements included mortality, number of infections, length of stay, units of blood transfused in and out of the operating room, number of operations, and anticoagulant use. A total of 21 burn centers contributed data on 666 patients; 79% of patients survived and received a mean of 14 units of packed red blood cells during their hospitalization. Mortality was related to patient age, total body surface area burn, inhalation injury, number of units of blood transfused outside the operating room, and total number of transfusions. The number of infections per patient increased with each unit of blood transfused (odds ratio, 1.13; p<.001). Patients on anticoagulation during hospitalization received more blood than patients not on anticoagulation (16.3+/-1.5 vs. 12.3+/-1.5, p<.001). The number of transfusions received was associated with mortality and infectious episodes in patients with major burns even after factoring for indices of burn severity. The utilization of blood products in the treatment of major burn injury should be reserved for patients with a demonstrated physiologic need.

Lean Limit Phenomena

NASA Technical Reports Server (NTRS)

Law, C. K.

1983-01-01

The influence of stretch and preferential diffusion on premixed flame extinction and stability was investigated via two model flame configurations, namely the stagnation flame and the bunsen flame. Using a counterflow burner and a stagnation flow burner with a water-cooled wall, the effect of downstream heat loss on the extinction of a stretched premixed flame investigated for lean and rich propane/air and methane/air mixtures. It was demonstrated that extinction by stretch alone is possible only when the deficient reactant is the less mobile one. When it is the more mobile one, downstream heat loss or incomplete reaction is also needed to achieve extinction. The local extinction of bunsen flame tips and edges of hydrocarbon/air premixtures was investigated using a variety of burners. Results show that, while for both rich propane/air and butane/air mixtures tip opening occurs at a constant fuel equivalence ratio of 1.44 and is therefore independent of the intensity, uniformity, and configuration of the approach flow, for rich methane/air flames burning is intensified at the tip and therefore opening is not possible.

Coal combustion system

DOEpatents

Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

1988-01-01

In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

Planar Imaging of Hydroxyl in a High Temperature, High Pressure Combustion Facility

NASA Technical Reports Server (NTRS)

Hicks, Yolanda R.; Locke, Randy J.; Anderson, Robert C.; Ockunzzi, Kelly A.

1995-01-01

An optically accessible flame tube combustor is described which has high temperature, pressure, and air flow capabilities. The windows in the combustor measure 3.8 cm axially by 5.1 cm radially, providing 67 percent optical access to the square cross section flow chamber. The instrumentation allows one to examine combusting flows and combustor subcomponents, such as fuel injectors and air swirlers. These internal combustor subcomponents have previously been studied only with physical probes, such as temperature and species rakes. Planar laser-induced fluorescence (PLIF) images of OH have been obtained from this lean burning combustor burning Jet-A fuel. These images were obtained using various laser excitation lines of the OH A yields X (1,0) band for two fuel injector configurations with pressures ranging from 1013 kPa (10 atm) to 1419 kPa (14 atm), and equivalence ratios from 0.41 to 0. 59. Non-uniformities in the combusting flow, attributed to differences in fuel injector configuration, are revealed by these images.

Conventional engine technology. Volume 3: Comparisons and future potential

NASA Technical Reports Server (NTRS)

Dowdy, M. W.

1981-01-01

The status of five conventional automobile engine technologies was assessed and the future potential for increasing fuel economy and reducing exhaust emission was discussed, using the 1980 EPA California emisions standards as a comparative basis. By 1986, the fuel economy of a uniform charge Otto engine with a three-way catalyst is expected to increase 10%, while vehicles with lean burn (fast burn) engines should show a 20% fuel economy increase. Although vehicles with stratified-charge engines and rotary engines are expected to improve, their fuel economy will remain inferior to the other engine types. When adequate NO emissions control methods are implemented to meet the EPA requirements, vehicles with prechamber diesel engines are expected to yield a fuel economy advantage of about 15%. While successful introduction of direct injection diesel engine technology will provide a fuel savings of 30 to 35%, the planned regulation of exhaust particulates could seriously hinder this technology, because it is expected that only the smallest diesel engine vehicles could meet the proposed particulate requirements.

A CFD Study of Jet Mixing in Reduced Flow Areas for Lower Combustor Emissions

NASA Technical Reports Server (NTRS)

Smith, C. E.; Talpallikar, M. V.; Holdeman, J. D.

1991-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor has the potential of significantly reducing NO(x) emissions in combustion chambers of High Speed Civil Transport aircraft. Previous work on RQL combustors for industrial applications suggested the benefit of necking down the mixing section. A 3-D numerical investigation was performed to study the effects of neckdown on NO(x) emissions and to develop a correlation for optimum mixing designs in terms of neckdown area ratio. The results of the study showed that jet mixing in reduced flow areas does not enhance mixing, but does decrease residence time at high flame temperatures, thus reducing NO(x) formation. By necking down the mixing flow area by 4, a potential NO(x) reduction of 16:1 is possible for annual combustors. However, there is a penalty that accompanies the mixing neckdown: reduced pressure drop across the combustor swirler. At conventional combustor loading parameters, the pressure drop penalty does not appear to be excessive.

Comparison of Mixing Calculations for Reacting and Non-Reacting Flows in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

1994-01-01

A production 3-D elliptic flow code has been used to calculate non-reacting and reacting flow fields in an experimental mixing section relevant to a rich burn/quick mix/lean burn (RQL) combustion system. A number of test cases have been run to assess the effects of the variation in the number of orifices, mass flow ratio, and rich-zone equivalence ratio on the flow field and mixing rates. The calculated normalized temperature profiles for the non-reacting flow field agree qualitatively well with the normalized conserved variable isopleths for the reacting flow field indicating that non-reacting mixing experiments are appropriate for screening and ranking potential rapid mixing concepts. For a given set of jet momentum-flux ratio, mass flow ratio, and density ratio (J, MR, and DR), the reacting flow calculations show a reduced level of mixing compared to the non-reacting cases. In addition, the rich-zone equivalence ratio has noticeable effect on the mixing flow characteristics for reacting flows.

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.

Assessment of insulin resistance in lean women with polycystic ovary syndrome.

PubMed

Morciano, Andrea; Romani, Federica; Sagnella, Francesca; Scarinci, Elisa; Palla, Carola; Moro, Francesca; Tropea, Anna; Policola, Caterina; Della Casa, Silvia; Guido, Maurizio; Lanzone, Antonio; Apa, Rosanna

2014-07-01

To develop and validate a specific simple measure of insulin sensitivity using oral glucose tolerance test (OGTT) values for lean polycystic ovary syndrome (PCOS) women. Retrospective study. Gynecologic Outpatient Clinic of University Hospital, affiliated with Unit of Gynecologic Endocrinology. Totals of 201 lean and 198 overweight/obese (ov-ob) nondiabetic PCOS patients were retrospectively selected. None. All patients underwent OGTT, euglycemic-hyperinsulinemic clamp, and androgenic and biochemical assays. The predictive performance of each insulin resistance (IR) index was analyzed with the use of receiver operating characteristic (ROC) curves. Higher correlation coefficients with clamp studies were obtained with the Belfiore Area (RS=0.579) and the homeostasis-model assessment (HOMA)-M120 (RS=-0.576) in lean PCOS patients and with the Sib (RS=0.697) in ov-ob PCOS patients. The best predictive index of IR in lean PCOS was a HOMA-M120 value of ≥12.8 or more (area under the ROC curve [AUC] 92.4%). In the ov-ob PCOS population, the best predictive performance was obtained by a Sib of ≤10.2 or less (AUC 85.7%). IR should be assessed in all PCOS women, both lean and ov-ob subjects. The HOMA-M120 resulted as a very simple tool, validated specifically for the lean PCOS woman whose cardiometabolic impairment is more frequently misunderstood. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Illusion or delusion--Lean management in the health sector.

PubMed

McIntosh, Bryan; Sheppy, Bruce; Cohen, Ivan

2014-01-01

There has been considerable interest in the implementation of practices imported from manufacturing into healthcare as a solution to rising healthcare spending and disappointing patient safety indicators. One approach that has attracted particular interest is Lean management and the purpose of this paper is to engage with this topic. Secondary research. Despite widespread enthusiasm about the potential of Lean management processes, evidence about its contribution to higher organisational performance remains inconsistent. This paper engages with the major Lean concepts of operations management and human resource management, including just-in-time, total quality management, total productive maintenance and does not engage in-depth with concepts related to employee empowerment, and training This paper contributes to the organisational management literature in healthcare by showing that although Lean management seems to have the potential to improve organisational performance it is far from a panacea against under performing hospitals. It informs policy making by suggesting that a progressive managerial philosophy has a stronger impact on healthcare performance than the adoption of practices from any particular managerial approach. This paper provides a critical evaluation of the impact of Lean practices in informing healthcare policy. The paper contributes to the organisational management literature in healthcare by showing that even though Lean management in healthcare appears to have the potential to improve organisational performance; there remain problems with its application.

An Experimental Investigation of Self-Excited Combustion Dynamics in a Single Element Lean Direct Injection (LDI) Combustor

NASA Astrophysics Data System (ADS)

Gejji, Rohan M.

The management of combustion dynamics in gas turbine combustors has become more challenging as strict NOx/CO emission standards have led to engine operation in a narrow, lean regime. While premixed or partially premixed combustor configurations such as the Lean Premixed Pre-vaporized (LPP), Rich Quench Lean burn (RQL), and Lean Direct Injection (LDI) have shown a potential for reduced NOx emissions, they promote a coupling between acoustics, hydrodynamics and combustion that can lead to combustion instabilities. These couplings can be quite complex, and their detailed understanding is a pre-requisite to any engine development program and for the development of predictive capability for combustion instabilities through high-fidelity models. The overarching goal of this project is to assess the capability of high-fidelity simulation to predict combustion dynamics in low-emissions gas turbine combustors. A prototypical lean-direct-inject combustor was designed in a modular configuration so that a suitable geometry could be found by test. The combustor comprised a variable length air plenum and combustion chamber, air swirler, and fuel nozzle located inside a subsonic venturi. The venturi cross section and the fuel nozzle were consistent with previous studies. Test pressure was 1 MPa and variables included geometry and acoustic resonance, inlet temperatures, equivalence ratio, and type of liquid fuel. High-frequency pressure measurements in a well-instrumented metal chamber yielded frequencies and mode shapes as a function of inlet air temperature, equivalence ratio, fuel nozzle placement, and combustor acoustic resonances. The parametric survey was a significant effort, with over 105 tests on eight geometric configurations. A good dataset was obtained that could be used for both operating-point-dependent quantitative comparisons, and testing the ability of the simulation to predict more global trends. Results showed a very strong dependence of instability amplitude on the geometric configuration of the combustor, i.e., its acoustic resonance characteristics, with measured pressure fluctuation amplitudes ranged from 5 kPa (0.5% of mean pressure) to 200 kPa ( 20% of mean pressure) depending on combustor geometry. The stability behavior also showed a consistent and pronounced dependence on equivalence ratio and inlet air temperature. Instability amplitude increased with higher equivalence ratio and with lower inlet air temperature. A pronounced effect of fuel nozzle location on the combustion dynamics was also observed. Combustion instabilities with the fuel nozzle at the throat of the venturi throat were stronger than in the configuration with fuel nozzle 2.6 mm upstream of the nozzle. A second set of dynamics data was based on high-response-rate laser-based combustion diagnostics using an optically accessible combustor section. High-frequency measurements of OH*-chemiluminescence and OH-PLIF and velocity fields using PIV were obtained at a relatively stable, low equivalence ratio case and a less stable case at higher equivalence ratio. PIV measurements were performed at 5 kHz for non-reacting flow but glare from the cylindrical quartz chamber limited the field of view to a small region in the combustor. Quantitative and qualitative comparisons were made for five different combinations of geometry and operating condition that yielded discriminating stability behavior in the experiment with simulations that were carried out concurrently. Comparisons were made on the basis of trends and pressure mode data as well as with OH-PLIF measurements for the baseline geometry at equivalence ratios of 0.44 and 0.6. Overall, the ability of the simulation to match experimental data and trends was encouraging. Dynamic Mode Decomposition (DMD) analysis was performed on two sets of computations - a global 2-step chemistry mechanism and an 18-step chemistry mechanism - and the OH-PLIF images to allow comparison of dynamic patterns of heat release and OH distribution in the combustion zone. The DMD analysis was able to identify similar dominant unstable modes in the combustor. Recommendations for future work are based on the continued requirement for quantitative and spatio-temporally resolved data for direct comparison with computational efforts to develop predictive capabilities for combustion instabilities at relevant operating conditions. Discriminating instability behavior for the prototypical combustor demonstrated in this study is critical for any robust validation effort Unit physics based scaling of the current effort to multi-element combustors along with improvement in diagnostic techniques and analysis efforts are recommended for advancement in understanding of the complex physics in the multi-phase, three dimensional and turbulent combustion processes in the LDI combustor.

46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding...

46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding...

46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding...

46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding...

46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding...

Combat-related facial burns: analysis of strategic pitfalls.

PubMed

Johnson, Benjamin W; Madson, Andrew Q; Bong-Thakur, Sarah; Tucker, David; Hale, Robert G; Chan, Rodney K

2015-01-01

Burns constitute approximately 10% of all combat-related injuries to the head and neck region. We postulated that the combat environment presents unique challenges not commonly encountered among civilian injuries. The purpose of the present study was to determine the features commonly seen among combat facial burns that will result in therapeutic challenges and might contribute to undesired outcomes. The present study was a retrospective study performed using a query of the Burn Registry at the US Army Institute of Surgical Research Burn Center for all active duty facial burn admissions from October 2001 to February 2011. The demographic data, total body surface area of the burn, facial region body surface area involvement, and dates of injury, first operation, and first facial operation were tabulated and compared. A subset analysis of severe facial burns, defined by a greater than 7% facial region body surface area, was performed with a thorough medical record review to determine the presence of associated injuries. Of all the military burn injuries, 67.1% (n = 558) involved the face. Of these, 81.3% (n = 454) were combat related. The combat facial burns had a mean total body surface area of 21.4% and a mean facial region body surface area of 3.2%. The interval from the date of the injury to the first operative encounter was 6.6 ± 0.8 days and was 19.8 ± 2.0 days to the first facial operation. A subset analysis of the severe facial burns revealed that the first facial operation and the definitive coverage operation was performed at 13.45 ± 2.6 days and 31.9 ± 4.1 days after the injury, respectively. The mortality rate for this subset of patients was 32% (n = 10), with a high rate of associated inhalational injuries (61%, n = 19), limb amputations (29%, n = 9), and facial allograft usage (48%, n = 15) and a mean facial autograft thickness of 10.5/1,000th in. Combat-related facial burns present multiple challenges, which can contribute to suboptimal long-term outcomes. These challenges include prolonged transport to the burn center, delayed initial intervention and definitive coverage, and a lack of available high-quality color-matched donor skin. These gaps all highlight the need for novel anti-inflammatory and skin replacement strategies to more adequately address these unique combat-related obstacles. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. All rights reserved.

46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of tanks...

46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of tanks...

46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of tanks...

46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of tanks...

46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of tanks...

Epidemiology and outcome analysis of 6325 burn patients: a five-year retrospective study in a major burn center in Southwest China

PubMed Central

Li, Haisheng; Yao, Zhihui; Tan, Jianglin; Zhou, Junyi; Li, Yi; Wu, Jun; Luo, Gaoxing

2017-01-01

Burns are a major cause of injury worldwide. We investigated the epidemiology and outcomes of burn patients in a major burn center in southwest China between 2011 and 2015 to provide guidance for burn prevention. Of the 6,325 included burn patients, 66.8% were male and 34.7% were 0 ~ 6 years old. The incidence of burns peaked in autumn. Scald was the most common cause of burns, which was predominant in patients aged 0 ~ 6 years. The mean total body surface area (TBSA) of burns was 13.4%, and patients with burns ≤10% TBSA comprised 64.1% of all cases. Patients with full-thickness burns accounted for 40.1% of all patients and 81.0% of operated patients; these burns were primarily caused by flame (34.8%), scald (21.0%), and electricity (20.4%). Fifty-six deaths occurred (mortality 0.9%), and risk factors included full-thickness burns, larger TBSA and older age. The median length of stay was 17 days, and major risk factors included more operations, better outcomes and larger TBSA. Our data showed that closer attention should be paid to children under 6 years old, males, incidents in autumn and scald burns to prevent burn injuries. Furthermore, individualized burn prevention and treatment measures based on related risk factors should be adopted. PMID:28383066

Lean six sigma in healthcare.

PubMed

de Koning, Henk; Verver, John P S; van den Heuvel, Jaap; Bisgaard, Soren; Does, Ronald J M M

2006-01-01

Healthcare, as with any other service operation, requires systematic innovation efforts to remain competitive, cost efficient, and up-to-date. This article outlines a methodology and presents examples to illustrate how principles of Lean Thinking and Six Sigma can be combined to provide an effective framework for producing systematic innovation efforts in healthcare. Controlling healthcare cost increases, improving quality, and providing better healthcare are some of the benefits of this approach.

New operation strategy for driving the selectivity of NO x reduction to N 2, NH 3 or N 2O during lean/rich cycling of a lean NO x trap catalyst

DOE PAGES

Mráček, David; Koci, Petr; Choi, Jae -Soon; ...

2015-09-08

Periodical regeneration of NO x storage catalyst (also known as lean NO x trap) by short rich pulses of CO, H 2 and hydrocarbons is necessary for the reduction of nitrogen oxides adsorbed on the catalyst surface. Ideally, the stored NO x is converted into N 2, but N 2O and NH 3 by-products can be formed as well, particularly at low-intermediate temperatures. The N 2 and N 2O products are formed concurrently in two peaks. The primary peaks appear immediately after the rich-phase inception, and tail off with the breakthrough of the reductant front accompanied by NH 3 product.more » In addition, the secondary N 2 and N 2O peaks then appear at the rich-to-lean transition as a result of reactions between surface-deposited reductants/intermediates (CO, HC, NH 3, — NCO) and residual stored NO x under increasingly lean conditions.« less

Non-operative advances: what has happened in the last 50 years in paediatric surgery?

PubMed

Holland, Andrew J A; McBride, Craig A

2015-01-01

Paediatric surgeons remain paediatric clinicians who have the unique skill set to treat children with surgical problems that may require operative intervention. Many of the advances in paediatric surgical care have occurred outside the operating theatre and have involved significant input from medical, nursing and allied health colleagues. The establishment of neonatal intensive care units, especially those focusing on the care of surgical infants, has greatly enhanced the survival rates and long-term outcomes of those infants with major congenital anomalies requiring surgical repair. Educational initiatives such as the advanced trauma life support and emergency management of severe burns courses have facilitated improved understanding and clinical care. Paediatric surgeons have led with the non-operative management of solid organ injury following blunt abdominal trauma. Nano-crystalline burn wound dressings have enabled a reduced frequency of painful dressing changes in addition to effective antimicrobial efficacy and enhanced burn wound healing. Burns care has evolved so that many children may now be treated almost exclusively in an ambulatory care setting or as day case-only patients, with novel technologies allowing accurate prediction of burn would outcome and planning of elective operative intervention to achieve burn wound closure. © 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Acute pavement burns: a unique subset of burn injuries: a five-year review of resource use and cost impact.

PubMed

Silver, Andrew G; Dunford, Gerrit M; Zamboni, William A; Baynosa, Richard C

2015-01-01

This study focuses on the hospital care of a rare subset of burn injuries caused by contact with environmentally heated pavement, to further understand the required use of resources. This article aims to show that pavement burns are typically more severe than their flame/scald counterparts. A retrospective review of patients admitted to the burn center with injuries suffered from contact with hot pavement was performed. Patients were stratified on the presence or absence of altered mental status (AMS) and additional inciting factors. A representative sample of similarly sized flame and scald wounds treated in the same time period was compiled for comparison. Those with pavement burns had a significantly greater requirement for operative intervention, repetitive debridements, overall cost/percent burned, and lengthier hospital stays than those with flame/scald burns. Pavement burn victims with AMS were significantly more likely to require an operation, a greater cost/percent burned, and longer hospital stays than those without AMS. Pavement burns are significantly worse than similarly sized scald/flame burns with regards to length of stay and total hospital costs, and the necessity of initial and repetitive operative intervention. These discrepancies are even greater in patients with AMS as a concomitant inciting factor. It is apparent that these wounds often continue to deepen during a patient's stay, likely because of continued pressure on the wounds while recumbent. As such, this article highly recommends pressure off-loading beds and more aggressive debridement in the treatment of these unique injuries.

Reduced length of stay in hospital for burn patients following a change in practice guidelines: financial implications.

PubMed

Jansen, Leigh A; Hynes, Sally L; Macadam, Sheina A; Papp, Anthony

2012-01-01

The objective of this study was to analyze the financial implications of the implementation of new institutional practice guidelines including greater outpatient care and earlier operative intervention in a provincial burn center. A retrospective review was performed including all patients admitted to the Burn Unit with burns up to 20% TBSA between August 2005 and July 2009, including 2 years before and after the new guidelines were introduced. Daily costs for the burn unit were used to calculate this portion of cost. Length of stay (LOS) was based on actual data and representative clinical scenarios. Two hundred sixty-four patients were included. Mean LOS decreased from 10.3 to 3.9 (P < .01) and 21.0 to 13.3 (P > .05) for nonoperative burns 0 to 10% and 10 to 20% TBSA, respectively. Mean LOS for operative burns decreased from 16.6 to 12.9 and 32.3 to 29.8 days for 0 to 10% and 10 to 20% TBSA, respectively (P > .05). Burn patient management requires significant financial resources, and LOS has a large impact on cost. Given per diem rates of Can$1,663, scenario analysis shows potential cost savings of Can$19,956 per patient for operative and nonoperative burns <20% TBSA. With an average of 66 such patients treated each year, potential annual cost savings are Can$1.3 million. If outcomes are not compromised, earlier operative management and greater outpatient care can translate into significant cost savings. A prospective analysis capturing all costs and patient quality of life is required for further assessment.

Impact of lean six sigma process improvement methodology on cardiac catheterization laboratory efficiency.

PubMed

Agarwal, Shikhar; Gallo, Justin J; Parashar, Akhil; Agarwal, Kanika K; Ellis, Stephen G; Khot, Umesh N; Spooner, Robin; Murat Tuzcu, Emin; Kapadia, Samir R

2016-03-01

Operational inefficiencies are ubiquitous in several healthcare processes. To improve the operational efficiency of our catheterization laboratory (Cath Lab), we implemented a lean six sigma process improvement initiative, starting in June 2010. We aimed to study the impact of lean six sigma implementation on improving the efficiency and the patient throughput in our Cath Lab. All elective and urgent cardiac catheterization procedures including diagnostic coronary angiography, percutaneous coronary interventions, structural interventions and peripheral interventions performed between June 2009 and December 2012 were included in the study. Performance metrics utilized for analysis included turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start and manual sheath-pulls inside the Cath Lab. After implementation of lean six sigma in the Cath Lab, we observed a significant improvement in turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. The percentage of cases with optimal turn-time increased from 43.6% in 2009 to 56.6% in 2012 (p-trend<0.001). Similarly, the percentage of cases with an aggregate on-time start increased from 41.7% in 2009 to 62.8% in 2012 (p-trend<0.001). In addition, the percentage of manual sheath-pulls performed in the Cath Lab decreased from 60.7% in 2009 to 22.7% in 2012 (p-trend<0.001). The current longitudinal study illustrates the impact of successful implementation of a well-known process improvement initiative, lean six sigma, on improving and sustaining efficiency of our Cath Lab operation. After the successful implementation of this continuous quality improvement initiative, there was a significant improvement in the selected performance metrics namely turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. Copyright © 2016 Elsevier Inc. All rights reserved.

Acceptance of lean redesigns in primary care: A contextual analysis.

PubMed

Hung, Dorothy; Gray, Caroline; Martinez, Meghan; Schmittdiel, Julie; Harrison, Michael I

Lean is a leading change strategy used in health care to achieve short-term efficiency and quality improvement while promising longer-term system transformation. Most research examines Lean intervention to address isolated problems, rather than to achieve broader systemic changes to care delivery. Moreover, no studies examine contextual influences on system-wide Lean implementation efforts in primary care. The aim of this study was to identify contextual factors most critical to implementing and scaling Lean redesigns across all primary care clinics in a large, ambulatory care delivery system. Over 100 interviews and focus groups were conducted with frontline physicians, clinical staff, and operational leaders. Data analysis was guided by a modified Consolidated Framework for Implementation Research (CFIR), a popular implementation science framework. On the basis of expert recommendations, the modified framework targets factors influencing the implementation of process redesigns. This modified framework, the CFIR-PR, informed our identification of contextual factors that most impacted Lean acceptance among frontline physicians and staff. Several domains identified by the CFIR-PR were critical to acceptance of Lean redesigns. Regarding the implementation process acceptance was influenced by time and intensity of exposure to changes, "top-down" versus "bottom-up" implementation styles, and degrees of employee engagement in developing new workflows. Important factors in the inner setting were the clinic's culture and style of leadership, along with availability of information about Lean's effectiveness. Last, implementation efforts were impacted by individual and team characteristics regarding changed work roles and related issues of professional identity, authority, and autonomy. This study underscores the need for change leaders to consider the contextual factors that surround efforts to implement Lean in primary care. As Lean redesigns are scaled across a system, special attention is warranted with respect to the implementation approach, internal clinic setting, and implications for professional roles and identities of physicians and staff.

Study on lean thinking among MSMEs in the Machine tool sector in India

NASA Astrophysics Data System (ADS)

Priyaadarshini, R. G.; Sathish Kumar, V. R.; Aishwarya Rajlakshmi, S.

2018-02-01

In the era of stiff competition and customer expectations, manufacturing organizations across the world are struggling hard to minimize their costs and maximise their performance. Micro, Small and Medium enterprises (MSMEs), who are dependent on large corporate for business and support have a tall task of keeping pace quality in processes and output. They are in the constant vigil to adopt new systems and practices so that they can minimise their cost and maximize the productivity. This study has been conducted in the machine tool sector of Coimbatore, India; which houses more than 9000 companies and offers employment to over one lakh employees. They have a tremendous pressure to use scientific processes to increase their product quality and productivity. While Lean manufacturing has been the thrust to improve the competitiveness among MSMEs in India, this study has attempted to understand their attitude towards lean management and understand the extent to which companies practice lean tools and practices. It has been found that most of the organizations in the study possess a culture of lean thinking and possess the support of top management and employees also towards the initiative. It is also seen that the organizations that incorporated lean in their daily operations have been able to scale up their productivity.

[Epidemiological investigation on 2 133 hospitalized patients with electrical burns].

PubMed

Jiang, M J; Li, Z; Xie, W G

2017-12-20

Objective: To analyze the epidemiological characteristics of the hospitalized patients with electrical burns in Institute of Burns of Tongren Hospital of Wuhan University & Wuhan Third Hospital (hereinafter referred to as Institute of Burns of Wuhan Third Hospital), so as to provide reference for the prevention and treatment of electrical burns. Methods: Medical records of all hospitalized burn patients in Institute of Burns of Wuhan Third Hospital from January 2004 to December 2016 were collected. Genders, ages, social categories, seasons of injury, total burn areas, depths of wounds, electrical voltages of injury, sites of wound, treatment methods, amputation rates, lengths of hospital stay, operation costs, hospitalization costs, and treatment outcomes of the electrical burn patients were collected. Treatment methods, lengths of hospital stay, operation costs, and hospitalization costs of the thermal burn patients were collected and compared with those of the electrical burn patients. Electrical voltages of injury, amputation rates, operation costs, hospitalization costs, and treatment outcomes were compared and analyzed between the electrical contact burn patients and the electrical arc burn patients. Data were processed with Chi-square test and Wilcoxon rank-sum test. Results: During the 13 years, 23 534 burn patients were admitted to Institute of Burns of Wuhan Third Hospital, among whom 2 133 (9.1%) were with electrical burns, without obvious variation in admission number of electrical burn patients every year. There were 1 418 patients (66.5%) with electrical contact burns and 715 patients (33.5%) with electrical arc burns. The ratio of male to female was 11.2∶1.0 among the electrical burn patients with known genders. The proportions of three age groups of more than 20 years old and less than or equal to 30 years old, more than 30 years old and less than or equal to 40 years old, and more than 40 years old and less than or equal to 50 years old were relatively higher, which were 18.3% (391/2 133), 22.1% (471/2 133), and 24.6% (525/2 133), respectively. The first three social category groups in proportions were workers, peasants, and preschool children, which were 57.9% (1 235/2 133), 14.6% (311/2 133), and 6.0% (128/2 133), respectively. Among the electrical burn patients with known seasons of injury, most cases were injured in summer (659 cases, accounting for 34.1%), obviously more than the proportions in autumn (537 cases, accounting for 27.8%), spring (455 cases, accounting for 23.5%), and winter (283 cases, accounting for 14.6%), with χ (2) values from 8.414 to 149.573, P values below 0.01. The group of patients with total burn areas less than 10% total body surface area (TBSA) occupied the highest proportion (1 603 cases, accounting for 75.15%), among whom 229 (10.74%) were with scattered small wounds which were less than 1% TBSA. The percentage of electrical contact burn patients with deep wounds was 79.1% (1 122/1 418), which was obviously higher than 2.5% (18/715) of the electrical arc burn patients ( χ (2)=381.741, P <0.001). Among the patients with known electrical voltages of injury, patients injured by high voltage among the electrical contact burn patients accounted for 78.4% (469/598), which was obviously higher than 8.7% (11/127) of the electrical arc burn patients ( χ (2)=227.893, P <0.001). The most common wound site of the electrical burn patients was upper limbs (1 650 cases, accounting for 63.2%), followed by lower limbs (382 cases, accounting for 14.6%), head and neck (292 cases, accounting for 11.2%), trunk (247 cases, accounting for 9.5%), and hip and perineum (40 cases, accounting for 1.5%). The operation rate of electrical burn patients was 32.4% (691/2 133), obviously higher than 19.1% (3 860/20 209)of the thermal burn patients during the same period ( χ (2)=210.255, P <0.001). Wounds of 116 electrical contact burn patients were repaired with free flap by vascular anastomosis, of which 9 (7.8%) failed. The length of hospital stay, the operation cost, and the hospitalization cost of electrical burn patients were (28±29) d, (9 534±16 935) and (44 258±93 012) Yuan, respectively, obviously longer or higher than those of the thermal burn patients during the same period [(17±19) d, (2 990±8 916) and (23 291±88 340) Yuan, respectively, with Z values from -21.323 to -10.996, P values below 0.001]. The amputation rate and the death rate of electrical burn patients were 3.8% (82/2 133) and 0.8% (16/2 133) respectively. Compared with those of electrical arc burn patients, the amputation rate and the operation cost of electrical contact burn patients were obviously higher ( χ (2)=36.970, Z =-11.351, P values below 0.001), and the length of hospital stay of electrical contact burn patients was obviously longer ( Z =-5.181, P <0.001). There were no significant differences in hospitalization cost and treatment outcome between the electrical contact burn patients and the electrical arc burn patients ( Z =-1.461, χ (2)=1.673, P values above 0.05). Conclusions: The number and the proportion of hospitalized electrical burn patients in Institute of Burns of Wuhan Third Hospital were relatively high, indicating a hard task of prevention for electrical burns in Wuhan area. Working-age workers and farmers, and preschool children were the key groups in prevention from electrical burns. The length of hospital stay, the operation cost, and the hospitalization cost of electrical burn patients were obviously higher than those of thermal burn patients. The amputation rate and the operation cost of electrical contact burn patients were obviously higher than those of electrical arc burn patients, but there were no obvious differences in hospitalization cost or treatment outcome between them. Actively using tissue flaps including free flap to repair of wounds may be helpful to reduce the amputation rate, improve the results, and shorten the time of treatment.

HSCT Sector Combustor Evaluations for Demonstration Engine

NASA Technical Reports Server (NTRS)

Greenfield, Stuart; Heberling, Paul; Kastl, John; Matulaitis, John; Huff, Cynthia

2004-01-01

In LET Task 10, critical development issues of the HSCT lean-burn low emissions combustor were addressed with a range of engineering tools. Laser diagnostics and CFD analysis were applied to develop a clearer understanding of the fuel-air premixing process and premixed combustion. Subcomponent tests evaluated the emissions and operability performance of the fuel-air premixers. Sector combustor tests evaluated the performance of the integrated combustor system. A 3-cup sector was designed and procured for laser diagnostics studies at NASA Glenn. The results of these efforts supported the earlier selection of the Cyclone Swirler as the pilot stage premixer and the IMFH (Integrated Mixer Flame Holder) tube as the main stage premixer of the LPP combustor. In the combustor system preliminary design subtask, initial efforts to transform the sector combustor design into a practical subscale engine combustor met with significant challenges. Concerns about the durability of a stepped combustor dome and the need for a removable fuel injection system resulted in the invention and refinement of the MRA (Multistage Radial Axial) combustor system in 1994. The MRA combustor was selected for the HSR Phase II LPP subscale combustor testing in the CPC Program.

46 CFR 45.181 - Load line exemption requirements for the Burns Harbor and Milwaukee routes.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Load line exemption requirements for the Burns Harbor... line exemption requirements for the Burns Harbor and Milwaukee routes. Barges operating on the Burns... addresses and telephone numbers); (3) Service route (Milwaukee and/or Burns Harbor); (4) Design type...

46 CFR 45.181 - Load line exemption requirements for the Burns Harbor and Milwaukee routes.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Load line exemption requirements for the Burns Harbor... line exemption requirements for the Burns Harbor and Milwaukee routes. Barges operating on the Burns... addresses and telephone numbers); (3) Service route (Milwaukee and/or Burns Harbor); (4) Design type...

46 CFR 45.181 - Load line exemption requirements for the Burns Harbor and Milwaukee routes.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Load line exemption requirements for the Burns Harbor... line exemption requirements for the Burns Harbor and Milwaukee routes. Barges operating on the Burns... addresses and telephone numbers); (3) Service route (Milwaukee and/or Burns Harbor); (4) Design type...

46 CFR 45.181 - Load line exemption requirements for the Burns Harbor and Milwaukee routes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Load line exemption requirements for the Burns Harbor... line exemption requirements for the Burns Harbor and Milwaukee routes. Barges operating on the Burns... addresses and telephone numbers); (3) Service route (Milwaukee and/or Burns Harbor); (4) Design type...

46 CFR 45.181 - Load line exemption requirements for the Burns Harbor and Milwaukee routes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Load line exemption requirements for the Burns Harbor... line exemption requirements for the Burns Harbor and Milwaukee routes. Barges operating on the Burns... (Milwaukee and/or Burns Harbor); (4) Design type (covered/uncovered hopper, deck, etc.); (5) External...

Lean waste classification model to support the sustainable operational practice

NASA Astrophysics Data System (ADS)

Sutrisno, A.; Vanany, I.; Gunawan, I.; Asjad, M.

2018-04-01

Driven by growing pressure for a more sustainable operational practice, improvement on the classification of non-value added (waste) is one of the prerequisites to realize sustainability of a firm. While the use of the 7 (seven) types of the Ohno model now becoming a versatile tool to reveal the lean waste occurrence. In many recent investigations, the use of the Seven Waste model of Ohno is insufficient to cope with the types of waste occurred in industrial practices at various application levels. Intended to a narrowing down this limitation, this paper presented an improved waste classification model based on survey to recent studies discussing on waste at various operational stages. Implications on the waste classification model to the body of knowledge and industrial practices are provided.

Inability to determine tissue health is main indication of allograft use in intermediate extent burns.

PubMed

Fletcher, John L; Cancio, Leopoldo C; Sinha, Indranil; Leung, Kai P; Renz, Evan M; Chan, Rodney K

2015-12-01

Cutaneous allograft is commonly used in the early coverage of excised burns when autograft is unavailable. However, allograft is also applied in intermediate-extent burns (25-50%), during cases in which it is possible to autograft. In this population, there is a paucity of data on the indications for allograft use. This study explores the indications for allograft usage in moderate size burns. Under an IRB-approved protocol, patients admitted to our burn unit between March 2003 and December 2010 were identified through a review of the burn registry. Data on allograft use, total burn surface area, operation performed, operative intent, number of operations, intensive care unit length of stay, and overall length of stay were collected and analyzed. Data are presented as means±standard deviations, except where noted. In the study period, 146 patients received allograft during their acute hospitalization. Twenty-five percent of allograft recipients sustained intermediate-extent burns. Patients with intermediate-extent burns received allograft later in their hospitalization than those with large-extent (50-75% TBSA) burns (6.8 days vs. 3.4 days, p=0.01). Allografted patients with intermediate-extent burns underwent more operations (10.8 vs. 6.1, p=0.002) and had longer hospitalizations (78.3 days vs. 40.9 days, p<0.001) than non-allografted patients, when controlled for TBSA. Clinical rationale for placement of allograft in this population included autograft failure, uncertain depth of excision, lack of autograft donor site, and wound complexity. When uncertain depth of excision was the indication, allograft was universally applied onto the face. In half of allografted intermediate-extent burn patients the inability to identify a viable recipient bed was the ultimate reason for allograft use. Unlike large body surface area burns, allograft skin use in intermediate-extent injury occurs later in the hospitalization and is driven by the inability to determine wound bed suitability for autograft application. Allograft application can be utilized to test recipient site viability in cases of autograft failure or uncertain depth of excision. Published by Elsevier Ltd.

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.

Contractors are cautiously optimistic

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

Stremel, K.

1984-10-01

Anticipating stable crew counts and marginal increases in operator exploration budgets, geophysical contractors are cautiously optimistic about continued industry growth. Most companies are operating on lean profits, and more business consolidations are expected as the market gradually rebounds. Prospects for an upturn in geophysical operations by oil companies are discussed.

An unsuspected cause of meal-time morbidity: instant noodle scald burns.

PubMed

Koltz, Peter F; Wasicek, Philip; Mays, Chester; Bell, Derek E

2013-01-01

Observational analysis revealed a concerning frequency of scald burns secondary to instant noodles. A literature review reveals studies with small sample sizes of pediatric populations and analysis of container engineering. The adult cohort, treatments, and short-term outcomes have been neglected. Considering these deficiencies, we reviewed our institution's experience with burns secondary to instant noodles. Patient encounters due to instant noodle burns from January 1, 2007, through May 15, 2011, were reviewed. Demographics, burn characteristics, treatment, length of stay, number of operative interventions, and complications were analyzed. Eight hundred fifty-two patients were seen (460 were admitted) for scald burns of all pathogenesis. Of these, 121 (14%) were seen for burns secondary to noodles (63 men and 58 women). Of these, 48 were older than age 4 (group 1), and 73 were younger than age 4 (group 2). TBSA was 2.34 in group 1 and 1.64 in group 2 (P = .04). The most commonly burned areas in group 1 were extremities (n = 43) and in group 2 were chest (n = 32) and extremities (n = 31). Seven patients in group 1 and two patients in group 2 required operative intervention. Length of stay in groups 1 and 2 were 3.5 and 6 days, respectively. Noodle scald burns cause morbidity at all ages. Pediatric burns due to noodles are frequently managed conservatively but more often necessitate inpatient treatment. The nonpediatric population has larger TBSA and requires more frequent operative intervention. The morbidity of noodle burns is significant. Increased public education and container re-engineering is warranted.

46 CFR 167.30-10 - Special operating requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SCHOOL SHIPS Repairs or Alterations § 167.30-10 Special operating requirements. Inspection and testing required when making alterations, repairs, or other such operations involving riveting, welding, burning..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

Effects of whole-body vibration exercise on bone mineral content and density in thermally injured children.

PubMed

Edionwe, Joel; Hess, Cameron; Fernandez-Rio, Javier; Herndon, David N; Andersen, Clark R; Klein, Gordon L; Suman, Oscar E; Amonette, William E

2016-05-01

Loss of bone mass, muscle mass, and strength leads to significant disability in severely burned children. We assessed the effects of exercise combined with whole-body vibration (WBV) on bone mass, lean mass (LM), and muscle strength in children recovering from burns. Nineteen burned children (≥30% total body surface area [TBSA] burns) were randomly assigned to a 6-week exercise regimen either alone (EX; n=10) or in combination with a 6-week WBV training regimen (EX+WBV; n=9). WBV was performed concurrent to the exercise regimen for 5days/week on a vibrating platform. Dual-energy X-ray absorptiometry quantified bone mineral content (BMC), bone mineral density (BMD), and LM; knee extension strength was assessed using isokinetic dynamometry before and after training. Alpha was set at p<0.05. Both groups were similar in age, height, weight, TBSA burned, and length of hospitalization. Whole-body LM increased in the EX group (p=0.041) and trended toward an increase in the EX+WBV group (p=0.055). On the other hand, there were decreases in leg BMC for both groups (EX, p=0.011; EX+WBV, p=0.047), and in leg BMD for only the EX group (EX, p<0.001; EX+WBV, p=0.26). Truncal BMC decreased in only the EX group (EX, p=0.009; EX+WBV, p=0.61), while BMD decreased in both groups (EX, p<0.001; EX+WBV group, p<0.001). Leg strength increased over time in the EX group (p<0.001) and the EX+WBV group (p<0.001; between-group p=0.31). Exercise in combination with WBV may help attenuate regional bone loss in children recovering from burns. Studies are needed to determine the optimal magnitude, frequency, and duration of the vibration protocol, with attention to minimizing any potential interference with wound healing and graft closure. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Nitric oxide activates intradomain disulfide bond formation in the kinase loop of Akt1/PKBα after burn injury

PubMed Central

LU, X.-M.; TOMPKINS, R.G.; FISCHMAN, A.J.

2013-01-01

Severe burn injury is an acute inflammatory state with massive alterations in gene expression and levels of growth factors, cytokines and free radicals. During the catabolic processes, changes in insulin sensitivity and skeletal muscle wasting (unintended loss of 5–15% of lean body mass) are observed clinically. Here, we reveal a novel molecular mechanism of Akt1/protein kinase Bα (Akt1/PKBα) regulated via cross-talking between dephosphorylation of Thr308 and S-nitrosylation of Cys296 post severe burn injury, which were characterized using nano-LC interfaced with tandem quadrupole time-of-fight mass spectrometry (Q-TOF)micro tandem mass spectrometry in both in vitro and in vivo studies. For the in vitro studies, Akt1/PKBα was S-nitrosylated with S-nitrosoglutathione and derivatized by three methods. The derivatives were isolated by SDS-PAGE, trypsinized and analyzed by the tandem MS. For the in vivo studies, Akt1/PKBα in muscle lysates from burned rats was immuno-precipitated, derivatized with HPDP-Biotin and analyzed as above. The studies demonstrated that the NO free radical reacts with the free thiol of Cys296 to produce a Cys296-SNO intermediate which accelerates interaction with Cys310 to form Cys296-Cys310 in the kinase loop. MS/MS sequence analysis indicated that the dipeptide, linked via Cys296-Cys310, underwent dephosphorylation at Thr308. These effects were not observed in lysates from sham animals. As a result of this dual effect of burn injury, the loose conformation that is slightly stabilized by the Lys297-Thr308 salt bridge may be replaced by a more rigid structure which may block substrate access. Together with the findings of our previous report concerning mild IRS-1 integrity changes post burn, it is reasonable to conclude that the impaired Akt1/PKBα has a major impact on FOXO3 subcellular distribution and activities. PMID:23314241

Effects of Whole-Body Vibration Exercise on Bone Mineral Content and Density in Thermally Injured Children

PubMed Central

Edionwe, Joel; Hess, Cameron; Fernandez-Rio, Javier; Herndon, David N.; Andersen, Clark R.; Klein, Gordon L.; Suman, Oscar E.; Amonette, William E.

2015-01-01

Background Loss of bone mass, muscle mass, and strength leads to significant disability in severely burned children. We assessed the effects of exercise combined with whole-body vibration (WBV) on bone mass, lean mass (LM), and muscle strength in children recovering from burns. Methods Nineteen burned children (≥30% total body surface area [TBSA] burns) were randomly assigned to a 6-week exercise regimen either alone (EX; n = 10) or in combination with a 6-week WBV training regimen (EX+WBV; n = 9). WBV was performed concurrent to the exercise regimen for 5 days/week on a vibrating platform. Dual-energy X-ray absorptiometry quantified bone mineral content (BMC), bone mineral density (BMD) and LM; knee extension strength was assessed using isokinetic dynamometry before and after training. Alpha was set at p < 0.05. Results Both groups were similar in age, height, weight, TBSA burned, and length of hospitalization. Whole-body LM increased in the EX group (p = 0.041) and trended toward an increase in the EX+WBV group (p = 0.055). On the other hand, there were decreases in leg BMC for both groups (EX, p = 0.011; EX+WBV, p = 0.047), and in leg BMD for only the EX group (EX, p < 0.001; EX+WBV, p = 0.26). Truncal BMC decreased in only the EX group (EX, p = 0.009; EX+WBV, p = 0.61), while BMD decreased in both groups (EX, p < 0.001; EX+WBV group, p < 0.001). Leg strength increased over time in the EX group (p < 0.001) and the EX+WBV group (p < 0.001; between-group P = 0.31). Conclusions Exercise in combination with WBV may help attenuate regional bone loss in children recovering from burns. Studies are needed to determine the optimal magnitude, frequency, and duration of the vibration protocol, with attention to minimizing any potential interference with wound healing and graft closure. PMID:26796240

Comparison Between Civilian Burns and Combat burns From Operation Iraqi Freedom and Operation Enduring Freedom

DTIC Science & Technology

2006-06-01

to the average burn size reported from the ABA Burn Registry in 1995 (14% TBSA).20 We also found that the time to death in those who died, time on...after a prolonged stay in theater (up to 30 days, COL (retired) Basil A. Pruitt, personal commu- nication). They found a mortality rate of 7.9% in...from the green books that you know about. When we have that, we may be able to make that same comparison from the Vietnam era. DR. BASIL A. PRUITT, JR

Investigation of key parameters for the development of reliable ITER baseline operation scenarios using CORSICA

NASA Astrophysics Data System (ADS)

Kim, S. H.; Casper, T. A.; Snipes, J. A.

2018-05-01

ITER will demonstrate the feasibility of burning plasma operation by operating DT plasmas in the ELMy H-mode regime with a high ratio of fusion power gain Q ~ 10. 15 MA ITER baseline operation scenario has been studied using CORSICA, focusing on the entry to burn, flat-top burning plasma operation and exit from burn. The burning plasma operation for about 400 s of the current flat-top was achieved in H-mode within the various engineering constraints imposed by the poloidal field coil and power supply systems. The target fusion gain (Q ~ 10) was achievable in the 15 MA ITER baseline operation with a moderate amount of the total auxiliary heating power (~50 MW). It has been observed that the tungsten (W) concentration needs to be maintained low level (n w/n e up to the order of 1.0  ×  10-5) to avoid the radiative collapse and uncontrolled early termination of the discharge. The dynamic evolution of the density can modify the H-mode access unless the applied auxiliary heating power is significantly higher than the H-mode threshold power. Several qualitative sensitivity studies have been performed to provide guidance for further optimizing the plasma operation and performance. Increasing the density profile peaking factor was quite effective in increasing the alpha particle self-heating power and fusion power multiplication factor. Varying the combination of auxiliary heating power has shown that the fusion power multiplication factor can be reduced along with the increase in the total auxiliary heating power. As the 15 MA ITER baseline operation scenario requires full capacity of the coil and power supply systems, the operation window for H-mode access and shape modification was narrow. The updated ITER baseline operation scenarios developed in this work will become a basis for further optimization studies necessary along with the improvement in understanding the burning plasma physics.

40 CFR 279.23 - On-site burning in space heaters.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 27 2014-07-01 2014-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

40 CFR 279.23 - On-site burning in space heaters.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 28 2013-07-01 2013-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

40 CFR 279.23 - On-site burning in space heaters.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

40 CFR 279.23 - On-site burning in space heaters.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 28 2012-07-01 2012-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

40 CFR 279.23 - On-site burning in space heaters.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 27 2011-07-01 2011-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

40 CFR 60.2974 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2012 CFR

2012-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... and Qualification Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2013 CFR

2013-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2014 CFR

2014-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2012 CFR

2012-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2010 CFR

2010-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.2974 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2011 CFR

2011-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... and Qualification Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2011 CFR

2011-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.2974 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2010 CFR

2010-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... and Qualification Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

Wound management and outcome of 595 electrical burns in a major burn center.

PubMed

Li, Haisheng; Tan, Jianglin; Zhou, Junyi; Yuan, Zhiqiang; Zhang, Jiaping; Peng, Yizhi; Wu, Jun; Luo, Gaoxing

2017-06-15

Electrical burns are important causes of trauma worldwide. This study aims to analyze the clinical characteristics, wound management, and outcome of electric burns. This retrospective study was performed at the Institute of Burn Research of the Third Military Medical University during 2013-2015. Data including the demographics, injury patterns, wound treatment, and outcomes were collected and analyzed. A total of 595 electrical burn patients (93.8% males) were included. The average age was 37.3 ± 14.6 y, and most patients (73.5%) were aged 19∼50 years. Most patients (67.2%) were injured in work-related circumstances. The mean total body surface area was 8.8 ± 11.8% and most wounds (63.5%) were full-thickness burns. Operation times of high-voltage burns and current burns were higher than those of low-voltage burns and arc burns, respectively. Of the 375 operated patients, 83.2% (n = 312) underwent skin autografting and 49.3% (n = 185) required skin flap coverage. Common types of skin flaps were adjacent (50.3%), random (42.2%), and pedicle (35.7%). Amputation was performed in 107 cases (18.0%) and concentrated on the hands (43.9%) and upper limbs (39.3%). The mean length of stay was 42.9 ± 46.3 d and only one death occurred (0.2%). Current burns and higher numbers of operations were major risk factors for amputation and length of stay, respectively. Electrical burns mainly affected adult males with occupational exposures in China. Skin autografts and various skin flaps were commonly used for electric burn wound management. More standardized and effective strategies of treatment and prevention are still needed to decrease amputation rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Hypersensitivity of prediabetic JCR:LA-cp rats to fine airborne combustion particle-induced direct and noradrenergic-mediated vascular contraction.

PubMed

Proctor, Spencer D; Dreher, Kevin L; Kelly, Sandra E; Russell, James C

2006-04-01

Particulate matter with mean aerodynamic diameter < or =2.5 microm (PM(2.5)), from diesel exhaust, coal or residual oil burning, and from industrial plants, is a significant component of airborne pollution. Type 2 diabetes is associated with enhanced risk of adverse cardiovascular events following exposure to PM(2.5). Particle properties, sources, and pathophysiological mechanisms responsible are unknown. We studied effects of residual oil fly ash (ROFA) from a large U.S. powerplant on vascular function in a prediabetic, hyperinsulinemic model, the JCR:LA-cp rat. Residual oil fly ash leachate (ROFA-L) was studied using aortic rings from young-adult, obese, insulin-resistant rats and lean normal rats in vitro. Contractile response to phenylephrine and relaxant response to acetylcholine were determined in the presence and absence of L-NAME (N(G)-nitro-L-arginine methyl ester). In a separate series of studies, the direct contractile effects of ROFA-L on repeated exposure were determined. ROFA-L (12.5 microg ml(-1)) increased phenylephrine-mediated contraction in obese (p < 0.05), but not in lean rat aortae, with the effect being exacerbated by L-NAME, and it reduced acetylcholine-mediated relaxation of both obese and lean aortae (p < 0.0001). Initial exposure of aortae to ROFA-L caused a small contractile response (<0.05 g), which was markedly greater on second exposure in the obese (approximately 0.6 g, p < 0.0001) aortae but marginal in lean (approximately 0.1 g) aortae. Our data demonstrate that bioavailable constituents of oil combustion particles enhance noradrenergic-mediated vascular contraction, impair endothelium-mediated relaxation, and induce direct vasocontraction in prediabetic rats. These observations provide the first direct evidence of the causal properties of PM(2.5) and identify the pathophysiological role of the early prediabetic state in susceptibility to environmentally induced cardiovascular disease. These are important implications for public health and public policy.

Redesigning assembly stations using ergonomic methods as a lean tool.

PubMed

Eswaramoorthi, M; John, Mervyn; Rajagopal, C Arjun; Prasad, P S S; Mohanram, P V

2010-01-01

With the current state of the global economy, demand for various products plummeting. To sustain in the market, companies have to reduce cost and improve quality. Today, companies have started implementing new philosophies like TQM, TPM, six sigma and lean manufacturing techniques to remain competitive in the market. Lean manufacturing is an emerging philosophy which continuously strives to reduce waste. The main objective of analyzing the assembly line with a lean perspective is to identify the areas related to human interface with other systems that could lead to the generation of waste. Improper workplace design leads to unreasonable mental or physical burden and results in waste generation like slow work (delay and inventory), and defects, which is named as muri waste. An attempt has been made in this paper to locate muri waste and create a "Lean assembly line". The proposed method, based on the use of Rapid Upper Limb Assessment (RULA) with CATIA V5 platform, has allowed the measurement of a large set of operator posture parameters and assessment of ergonomic stresses. Based on the results, the process stations in the assembly line were redesigned to prevent the generation of waste.

The Burns Registry of Australia and New Zealand: progressing the evidence base for burn care.

PubMed

Cleland, Heather; Greenwood, John E; Wood, Fiona M; Read, David J; Wong She, Richard; Maitz, Peter; Castley, Andrew; Vandervord, John G; Simcock, Jeremy; Adams, Christopher D; Gabbe, Belinda J

2016-03-21

Analysis of data from the Burns Registry of Australia and New Zealand (BRANZ) to determine the extent of variation between participating units in treatment and in specific outcomes during the first 4 years of its operation. BRANZ, an initiative of the Australian and New Zealand Burn Association, is a clinical quality registry developed in accordance with the Australian Commission on Safety and Quality in Healthcare national operating principles. Patients with burn injury who fulfil pre-defined criteria are transferred to and managed in designated burn units. There are 17 adult and paediatric units in Australia and New Zealand that manage almost all patients with significant burn injury. Twelve of these units treat adult patients. Data on 7184 adult cases were contributed by ten acute adult burn units to the registry between July 2010 and June 2014.Major outcomes: In-hospital mortality, hospital length of stay, skin grafting rates, and rates of admission to intensive care units. Considerable variations in unit profiles (including numbers of patients treated), in treatment and in outcomes were identified. Despite the highly centralised delivery of care to patients with severe or complex burn injury, and the relatively small number of specialist burn units, we found significant variation between units in clinical management and in outcomes. BRANZ data from its first 4 years of operation support its feasibility and the value of further development of the registry. Based on these results, the focus of ongoing research is to improve understanding of the reasons for variations in practice and of their effect on outcomes for patients, and to develop evidence-informed clinical guidelines for burn management in Australia and New Zealand.

The effect of incomplete fuel-air mixing on the lean limit and emissions characteristics of a Lean Prevaporized Premixed (LPP) combustor

NASA Technical Reports Server (NTRS)

Santavicca, D. A.; Steinberger, R. L.; Gibbons, K. A.; Citeno, J. V.; Mills, S.

1993-01-01

Results are presented from an experimental study of the effect of incomplete fuel-air mixing on the lean limit and emissions characteristics of a lean, prevaporized, premixed (LPP), coaxial mixing tube combustor. Two-dimensional exciplex fluorescence was used to characterize the degree of fuel vaporization and mixing at the combustor inlet under non-combusting conditions. These tests were conducted at a pressure of 4 atm., a temperature of 400 C, a mixer tube velocity of 100 m/sec and an equivalence ratio of .8, using a mixture of tetradecane, 1 methyl naphthalene and TMPD as a fuel simulant. Fuel-air mixtures with two distinct spatial distributions were studied. The exciplex measurements showed that there was a significant amount of unvaporized fuel at the combustor entrance in both cases. One case, however, exhibited a very non-uniform distribution of fuel liquid and vapor at the combustor entrance, i.e., with most of the fuel in the upper half of the combustor tube, while in the other case, both the fuel liquid and vapor were much more uniformly distributed across the width of the combustor entrance. The lean limit and emissions measurements were all made at a pressure of 4 atm. and a mixer tube velocity of 100 m/sec, using Jet A fuel and both fuel-air mixture distributions. Contrary to what was expected, the better mixed case was found to have a substantially leaner operating limit. The two mixture distributions also unexpectedly resulted in comparable NO(x) emissions, for a given equivalence ratio and inlet temperature, however, lower NO(x) emissions were possible in the better mixed case due to its leaner operating limit.

Lean principles to optimize instrument utilization for spine surgery in an academic medical center: an opportunity to standardize, cut costs, and build a culture of improvement.

PubMed

Lunardini, David; Arington, Richard; Canacari, Elena G; Gamboa, Kelly; Wagner, Katiri; McGuire, Kevin J

2014-09-15

Case study OBJECTIVE.: To optimize the utilization of operating room instruments for orthopedic and neurosurgical spine cases in an urban level 1 academic medical center through application of Lean principles. Process improvement systems such as Lean have been adapted to health care and offer an opportunity for frank assessment of surgical routines to increase efficiency and enhance value. The goal has been to safely reduce the financial burden to the health care system without compromising care and if possible reallocate these resources or gains in efficiency to further improve the value to the patient. The investigators identified instruments as a source of waste in the operating room and proposed a Lean process assessment. The instruments and the instrument processing workflow were described. An audit documented the utilization of each instrument by orthopedic surgeons and neurosurgeons through observation of spine cases. The data were then presented to the stakeholders, including surgeons, the perioperative director, and representatives from nursing, central processing, and the surgical technicians. Of the 38 cases audited, only 89 (58%) of the instruments were used at least once. On the basis of the data and stakeholder consensus, 63 (41%) of the instruments were removed, resulting in a weight reduction of 17.5 lb and consolidation of 2 instrument sets into 1. Projected cost savings were approximately $41,000 annually. Although new instruments were purchased to standardize sets, the return on investment was estimated to be 2 years. Inefficient surgical routines may comprise significant resource waste in an institution. Process assessment is an important tool in decreasing health care costs, with objectivity provided by Lean or similar principles, and essential impetus to change provided by stakeholders. 4.

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DRE trial burn. (5) Low risk waste. Owners and operators of boilers or industrial furnaces that burn... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction...

40 CFR 266.104 - Standards to control organic emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... DRE trial burn. (5) Low risk waste. Owners and operators of boilers or industrial furnaces that burn... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.104...) of this section, a boiler or industrial furnace burning hazardous waste must achieve a destruction...

Outcomes After Cardiac Arrest in an Adult Burn Center

DTIC Science & Technology

2013-12-07

defibrillation at our institution, either in the burn operating room (BOR) or burn intensive care unit (BICU). We included patients who experi- enced CA in...of this study design. In other studies, the time between CA and defibrillation and, in children, the time between burn and fluid resuscitation have

Mechanism study on pressure fluctuation of pump-turbine runner with large blade lean angle

NASA Astrophysics Data System (ADS)

Yulin, Fan; Xuhe, Wang; Baoshan, Zhu; Dongyue, Zhou; Xijun, Zhou

2016-11-01

Excessive pressure fluctuations in the vaneless space can cause mechanical vibration and even mechanical failures in pump-turbine operation. Mechanism studies on the pressure fluctuations and optimization design of blade geometry to reduce the pressure fluctuations have important significance in industrial production. In the present paper, two pump-turbine runners with big positive and negative blade lean angle were designed by using a multiobjective design strategy. Model test showed that the runner with negative blade lean angle not only had better power performance, but also had lower pressure fluctuation than the runner with positive blade lean angle. In order to figure out the mechanism of pressure fluctuation reduction in the vaneless;jik8space, full passage model for both runners were built and transient CFD computations were conducted to simulate the flow states inside the channel. Detailed flow field analyses indicated that the difference of low-pressure area in the trailing edge of blade pressure side were the main causes of pressure fluctuation reduction in the vaneless space.

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.

Lean blowout limits of a gas turbine combustor operated with aviation fuel and methane

NASA Astrophysics Data System (ADS)

Xiao, Wei; Huang, Yong

2016-05-01

Lean blowout (LBO) limits is critical to the operational performance of combustion systems in propulsion and power generation. The swirl cup plays an important role in flame stability and has been widely used in aviation engines. Therefore, the effects of swirl cup geometry and flow dynamics on LBO limits are significant. An experiment was conducted for studying the lean blowout limits of a single dome rectangular model combustor with swirl cups. Three types of swirl cup (dual-axial swirl cup, axial-radial swirl cup, dual-radial swirl cup) were employed in the experiment which was operated with aviation fuel (Jet A-1) and methane under the idle condition. Experimental results showed that, with using both Jet A-1 and methane, the LBO limits increase with the air flow of primary swirler for dual-radial swirl cup, while LBO limits decrease with the air flow of primary swirler for dual-axial swirl cup. In addition, LBO limits increase with the swirl intensity for three swirl cups. The experimental results also showed that the flow dynamics instead of atomization poses a significant influence on LBO limits. An improved semi-empirical correlation of experimental data was derived to predict the LBO limits for gas turbine combustors.

46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of cargo...

Use of lean and six sigma methodology to improve operating room efficiency in a high-volume tertiary-care academic medical center.

PubMed

Cima, Robert R; Brown, Michael J; Hebl, James R; Moore, Robin; Rogers, James C; Kollengode, Anantha; Amstutz, Gwendolyn J; Weisbrod, Cheryl A; Narr, Bradly J; Deschamps, Claude

2011-07-01

Operating rooms (ORs) are resource-intense and costly hospital units. Maximizing OR efficiency is essential to maintaining an economically viable institution. OR efficiency projects often focus on a limited number of ORs or cases. Efforts across an entire OR suite have not been reported. Lean and Six Sigma methodologies were developed in the manufacturing industry to increase efficiency by eliminating non-value-added steps. We applied Lean and Six Sigma methodologies across an entire surgical suite to improve efficiency. A multidisciplinary surgical process improvement team constructed a value stream map of the entire surgical process from the decision for surgery to discharge. Each process step was analyzed in 3 domains, ie, personnel, information processed, and time. Multidisciplinary teams addressed 5 work streams to increase value at each step: minimizing volume variation; streamlining the preoperative process; reducing nonoperative time; eliminating redundant information; and promoting employee engagement. Process improvements were implemented sequentially in surgical specialties. Key performance metrics were collected before and after implementation. Across 3 surgical specialties, process redesign resulted in substantial improvements in on-time starts and reduction in number of cases past 5 pm. Substantial gains were achieved in nonoperative time, staff overtime, and ORs saved. These changes resulted in substantial increases in margin/OR/day. Use of Lean and Six Sigma methodologies increased OR efficiency and financial performance across an entire operating suite. Process mapping, leadership support, staff engagement, and sharing performance metrics are keys to enhancing OR efficiency. The performance gains were substantial, sustainable, positive financially, and transferrable to other specialties. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Multifuel evaluation of rich/quench/lean combustor

NASA Technical Reports Server (NTRS)

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

1982-01-01

The fuel flexible combustor technology was developed for application to the Model 570-K industrial gas turbine engine. The technology, to achieve emission goals, emphasizes dry NOx reduction methods. Due to the high levels of fuel-bound nitrogen (FBN), control of NOx can be effected through a staged combustor with a rich initial combustion zone. A rich/quench/lean variable geometry combustor utilizes the technology presented to achieve low NOx from alternate fuels containing FBN. The results focus on emissions and durability for multifuel operation.

On the effects of fuel leakage on CO production from household burners as revealed by LIF and CARS

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

Van der Meij, C.E.; Mokhov, A.V.; Jacobs, R.A.A.M.

Measurements of the distributions of CO, OH, and temperature in flames from two commonly used, commercially available household burners are presented. The local mole fractions of CO and relative distribution of OH have been obtained using laser-induced fluorescence, while the local temperatures have, been determined by coherent anti-Stokes Raman scattering (CARS). For both burners, burning in the open air, CO formation outside the main flames has been observed and attributed to the leakage of fuel-air mixture at the edges of the flame, where the fuel is subsequently converted to CO in the boundary layer between the flame and the surroundings.more » For a rich-premixed, multiblade burner, which gives Bunsen-like flames, the CO produced by the leaking fuel appears to be oxidized by OH arising from the outer cones of adjacent flames, and burns out to low concentrations. In the case of a lean-premixed burner, the CO produced by fuel leakage remains in the cool boundary layer without adequate burnout. Possible consequences for appliance behavior are discussed.« less

Influence of gas compressibility on a burning accident in a mining passage

NASA Astrophysics Data System (ADS)

Demir, Sinan; Calavay, Anish Raman; Akkerman, V'yacheslav

2018-03-01

A recent predictive scenario of a methane/air/coal dust fire in a mining passage is extended by incorporating the effect of gas compressibility into the analysis. The compressible and incompressible formulations are compared, qualitatively and quantitatively, in both the two-dimensional planar and cylindrical-axisymmetric geometries, and a detailed parametric study accounting for coal-dust combustion is performed. It is shown that gas compression moderates flame acceleration, and its impact depends on the type of the fuel, its various thermal-chemical parameters as well as on the geometry of the problem. While the effect of gas compression is relatively minor for the lean and rich flames, providing 5-25% reduction in the burning velocity and thereby justifying the incompressible formulation in that case, such a reduction appears significant, up to 70% for near-stoichiometric methane-air combustion, and therefore it should be incorporated into a rigorous formulation. It is demonstrated that the flame tip velocity remains noticeably subsonic in all the cases considered, which is opposite to the prediction of the incompressible formulation, but qualitatively agrees with the experimental predictions from the literature.

Flow Structure Comparison for Two 7-Point LDI Configurations

NASA Technical Reports Server (NTRS)

Hicks, Yolanda R.; Tacina, Kathleen M.

2017-01-01

This paper presents a comparison primarily of the 2-D velocity profiles in the non-burning system; and for the luminescent flame structure for a 7-point Lean Direct Injector (LDI). This circular LDI array consists of a center element surrounded by six outer elements spaced 60 degrees apart; the spacing between all adjacent elements is the same. Each element consists of simplex atomizer that injects at the throat of a converging-diverging venturi, and an axial swirler upstream of the venturi throat to generate swirl. The two configurations were: 1) one which consists of all 60 co-swirling axial air swirlers, and; 2) one configuration which uses a 60 swirler in the center, surrounded by counter-swirling 45 swirlers. Testing was done at 5 atm and an inlet temperature of 800F. Two air reference velocities were considered in the cold flow measurements and one common air flow condition for the burning case.The 2D velocity profiles were determined using particle image velocimetry and the flame structure was determined using high speed photography.

77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

... Integrated Routing System-- NIRS].'' The FAA developed the AEDT 2a to model aircraft noise, fuel burn, and... operations schedule. These data are used to compute aircraft noise, fuel burn and emissions simultaneously... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Noise, Fuel Burn, and...

Spatially-varied erosion modeling using WEPP for timber harvested and burned hillslopes

Treesearch

Peter R. Robichaud; T. M. Monroe

1997-01-01

Spatially-varied hydrologic surface conditions exist on steep hillslopes after timber harvest operation and site preparation burning treatments. Site preparation burning creates low- and high-severity burn surface conditions or disturbances. In this study, a hillslope was divided into multiple combinations of surface conditions to determine how their spatial...

40 CFR 265.383 - Interim status thermal treatment devices burning particular hazardous waste.

Code of Federal Regulations, 2010 CFR

2010-07-01

... devices burning particular hazardous waste. 265.383 Section 265.383 Protection of Environment... status thermal treatment devices burning particular hazardous waste. (a) Owners or operators of thermal treatment devices subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or...

40 CFR 265.383 - Interim status thermal treatment devices burning particular hazardous waste.

Code of Federal Regulations, 2013 CFR

2013-07-01

... devices burning particular hazardous waste. 265.383 Section 265.383 Protection of Environment... status thermal treatment devices burning particular hazardous waste. (a) Owners or operators of thermal treatment devices subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or...

40 CFR 265.383 - Interim status thermal treatment devices burning particular hazardous waste.

Code of Federal Regulations, 2014 CFR

2014-07-01

... devices burning particular hazardous waste. 265.383 Section 265.383 Protection of Environment... status thermal treatment devices burning particular hazardous waste. (a) Owners or operators of thermal treatment devices subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or...

40 CFR 265.383 - Interim status thermal treatment devices burning particular hazardous waste.

Code of Federal Regulations, 2012 CFR

2012-07-01

... devices burning particular hazardous waste. 265.383 Section 265.383 Protection of Environment... status thermal treatment devices burning particular hazardous waste. (a) Owners or operators of thermal treatment devices subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or...

40 CFR 265.383 - Interim status thermal treatment devices burning particular hazardous waste.

Code of Federal Regulations, 2011 CFR

2011-07-01

... devices burning particular hazardous waste. 265.383 Section 265.383 Protection of Environment... status thermal treatment devices burning particular hazardous waste. (a) Owners or operators of thermal treatment devices subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or...

The risk of eye splash in burn surgery.

PubMed

Tehrani, H; Juma, A; Lambe, G; James, M I

2009-06-01

Although the incidence of eye splash injury has been assessed for a number of surgical specialities, such risks posed to the burn surgeon have not been previously quantified. During 100 consecutive procedures the operating burns team wore a clean set of goggles, counting the number of blood splashes on the goggles after each procedure. During this study there were 47 cases of potential eye splash injury, although the individual was only aware of 2 of these intra-operatively. Seven of the splashes involved more than 6 blood droplets on the goggles. The consultant burn surgeon was the most likely to be splashed, sustaining a potential injury in over half cases operated upon. Procedures greater than 45 min in length were more likely to result in a splash than those shorter than 45 min. We recommend that eye protection should be used either in the form of goggles or a visor and should encompass all burn theatre cases as a matter of policy.

Pattern and profile of electric burn injury cases at a Burn centre.

PubMed

Cheema, Saeed Ashraf

2016-01-01

Electrical burns are quite different from thermal and chemical burns. This study is from a centre which deals with job related electric burn injuries alone and thus can give a pure account of the electric burns and discuss the related peculiarities. Study aims to highlight the differences in the mechanism of electric burn injury, its mode of presentation, morbidity, complications and thus the treatment strategies as compared to rest of the burn injuries. This is a descriptive case series study of first consecutive 61 electric burn victims treated at a Burn Unit and Plastic Surgery centre. Cases were admitted and resuscitated at the emergency, and further treated at burn unit. Thorough history, examination findings and operative procedures were recorded. Patients were photographed for record as well. Emergency operative procedures, wound management, soft tissue coverage procedures and complications during the hospital stay were recorded and studied. Twenty cases (33%) were in the fifth decade of life. High voltage electric burn injury was seen in 42 (69%) of the cases. Whereas only 9 cases were treated conservatively, other 52 cases had 24 fasciotomies and 71 debridements. Series witnessed 10 expiries, and 22 amputations and all these were result of high voltage electric burns. Twenty eight soft tissue coverage procedures were carried out. Electric burn injuries are altogether different from rest of the burn injuries and must be treated accordingly. These injuries are peculiar for ongoing damage, extensive trauma, complications and prolonged morbidity. Treatment requires a high degree of suspicion, more aggressive management to unfold and minimize the deep seated insult.

Linear air-fuel sensor development

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

Garzon, F.; Miller, C.

1996-12-14

The electrochemical zirconia solid electrolyte oxygen sensor, is extensively used for monitoring oxygen concentrations in various fields. They are currently utilized in automobiles to monitor the exhaust gas composition and control the air-to-fuel ratio, thus reducing harmful emission components and improving fuel economy. Zirconia oxygen sensors, are divided into two classes of devices: (1) potentiometric or logarithmic air/fuel sensors; and (2) amperometric or linear air/fuel sensors. The potentiometric sensors are ideally suited to monitor the air-to-fuel ratio close to the complete combustion stoichiometry; a value of about 14.8 to 1 parts by volume. This occurs because the oxygen concentration changesmore » by many orders of magnitude as the air/fuel ratio is varied through the stoichiometric value. However, the potentiometric sensor is not very sensitive to changes in oxygen partial pressure away from the stoichiometric point due to the logarithmic dependence of the output voltage signal on the oxygen partial pressure. It is often advantageous to operate gasoline power piston engines with excess combustion air; this improves fuel economy and reduces hydrocarbon emissions. To maintain stable combustion away from stoichiometry, and enable engines to operate in the excess oxygen (lean burn) region several limiting-current amperometric sensors have been reported. These sensors are based on the electrochemical oxygen ion pumping of a zirconia electrolyte. They typically show reproducible limiting current plateaus with an applied voltage caused by the gas diffusion overpotential at the cathode.« less

Operation of Oil Burning Equipment and Incinerators. An Air Pollution Control Workbook, Preliminary Edition.

ERIC Educational Resources Information Center

New Jersey State Dept. of Environmental Protection, Trenton. Bureau of Air Pollution Control.

This workbook has been prepared for use by persons charged with the burning of fuels and waste products in the State of New Jersey. It is written for building superintendents, custodians, porters, handymen and operating engineers of public, apartment, commercial and office buildings. The manual emphasizes operating procedures that will help meet…

Low Emissions RQL Flametube Combustor Test Results

NASA Technical Reports Server (NTRS)

Chang, Clarence T.; Holdeman, James D.

2001-01-01

The overall objective of this test program was to demonstrate and evaluate the capability of the Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept for HSR applications. This test program was in support of the Pratt & Whitney and GE Aircraft Engines HSR low-NOx Combustor Program. Collaborative programs with Parker Hannifin Corporation and Textron Fuel Systems resulted in the development and testing of the high-flow low-NOx rich-burn zone fuel-to-air ratio research fuel nozzles used in this test program. Based on the results obtained in this test program, several conclusions can be made: (1) The RQL tests gave low NOx and CO emissions results at conditions corresponding to HSR cruise. (2) The Textron fuel nozzle design with optimal multiple partitioning of fuel and air circuits shows potential of providing an acceptable uniform local fuel-rich region in the rich burner. (3) For the parameters studied in this test series, the tests have shown T3 is the dominant factor in the NOx formation for RQL combustors. As T3 increases from 600 to 1100 F, EI(NOx) increases approximately three fold. (4) Factors which appear to have secondary influence on NOx formation are P4, T4, infinity(sub rb), V(sub ref,ov). (5) Low smoke numbers were measured for infinity(sub rb) of 2.0 at P4 of 120 psia.

40 CFR 258.24 - Air criteria.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.24 Air criteria. (a) Owners or operators of all MSWLFs... Act, as amended. (b) Open burning of solid waste, except for the infrequent burning of agricultural...

40 CFR 258.24 - Air criteria.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.24 Air criteria. (a) Owners or operators of all MSWLFs... Act, as amended. (b) Open burning of solid waste, except for the infrequent burning of agricultural...

Simplified jet fuel reaction mechanism for lean burn combustion application

NASA Technical Reports Server (NTRS)

Lee, Chi-Ming; Kundu, Krishna; Ghorashi, Bahman

1993-01-01

Successful modeling of combustion and emissions in gas turbine engine combustors requires an adequate description of the reaction mechanism. Detailed mechanisms contain a large number of chemical species participating simultaneously in many elementary kinetic steps. Current computational fluid dynamic models must include fuel vaporization, fuel-air mixing, chemical reactions, and complicated boundary geometries. A five-step Jet-A fuel mechanism which involves pyrolysis and subsequent oxidation of paraffin and aromatic compounds is presented. This mechanism is verified by comparing with Jet-A fuel ignition delay time experimental data, and species concentrations obtained from flametube experiments. This five-step mechanism appears to be better than the current one- and two-step mechanisms.

Method of controlling cyclic variation in engine combustion

DOEpatents

Davis, L.I. Jr.; Daw, C.S.; Feldkamp, L.A.; Hoard, J.W.; Yuan, F.; Connolly, F.T.

1999-07-13

Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling. 27 figs.

Method of controlling cyclic variation in engine combustion

DOEpatents

Davis, Jr., Leighton Ira; Daw, Charles Stuart; Feldkamp, Lee Albert; Hoard, John William; Yuan, Fumin; Connolly, Francis Thomas

1999-01-01

Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling.

A chemical reactor network for oxides of nitrogen emission prediction in gas turbine combustor

NASA Astrophysics Data System (ADS)

Hao, Nguyen Thanh

2014-06-01

This study presents the use of a new chemical reactor network (CRN) model and non-uniform injectors to predict the NOx emission pollutant in gas turbine combustor. The CRN uses information from Computational Fluid Dynamics (CFD) combustion analysis with two injectors of CH4-air mixture. The injectors of CH4-air mixture have different lean equivalence ratio, and they control fuel flow to stabilize combustion and adjust combustor's equivalence ratio. Non-uniform injector is applied to improve the burning process of the turbine combustor. The results of the new CRN for NOx prediction in the gas turbine combustor show very good agreement with the experimental data from Korea Electric Power Research Institute.

Blood transfusions in severe burn patients: Epidemiology and predictive factors.

PubMed

Wu, Guosheng; Zhuang, Mingzhu; Fan, Xiaoming; Hong, Xudong; Wang, Kangan; Wang, He; Chen, Zhengli; Sun, Yu; Xia, Zhaofan

2016-12-01

Blood is a vital resource commonly used in burn patients; however, description of blood transfusions in severe burns is limited. The purpose of this study was to describe the epidemiology of blood transfusions and determine factors associated with increased transfusion quantity. This is a retrospective study of total 133 patients with >40% total body surface area (TBSA) burns admitted to the burn center of Changhai hospital from January 2008 to December 2013. The study characterized blood transfusions in severe burn patients. Univariate and Multivariate regression analyses were used to evaluate the association of clinical variables with blood transfusions. The overall transfusion rate was 97.7% (130 of 133). The median amount of total blood (RBC and plasma), RBC and plasma transfusions was 54 units (Interquartile range (IQR), 20-84), 19 units (IQR, 4-37.8) and 28.5 units (IQR, 14.8-51.8), respectively. The number of RBC transfusion in and outside operation room was 7 (0, 14) and 11 (2, 20) units, and the number of plasma was 6 (0.5, 12) and 21 (11.5, 39.3) units. A median of one unit of blood was transfused per TBSA and an average of 4 units per operation was given in the series. The consumption of plasma is higher than that of RBC. On multivariate regression analysis, age, full-thickness TBSA and number of operations were significant independent predictors associated with the number of RBC transfusion, and coagulopathy and ICU length showed a trend toward RBC consumption. Predictors for increased plasma transfusion were female, high full-thickness TBSA burn and more operations. Severe burn patients received an ample volume of blood transfusions. Fully understanding of predictors of blood transfusions will allow physicians to better optimize burn patients during hospitalization in an effort to use blood appropriately. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

The correlation between ketamine and posttraumatic stress disorder in burned service members.

PubMed

McGhee, Laura L; Maani, Christopher V; Garza, Thomas H; Gaylord, Kathryn M; Black, Ian H

2008-02-01

Predisposing factors for posttraumatic stress disorder (PTSD) include experiencing a traumatic event, threat of injury or death, and untreated pain. Ketamine, an anesthetic, is used at low doses as part of a multimodal anesthetic regimen. However, since ketamine is associated with psychosomatic effects, there is a concern that ketamine may increase the risk of developing PTSD. This study investigated the prevalence of PTSD in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) service members who were treated for burns in a military treatment center. The PTSD Checklist-Military (PCL-M) is a 17-question screening tool for PTSD used by the military. A score of 44 or higher is a positive screen for PTSD. The charts of all OIF/OEF soldiers with burns who completed the PCL-M screening tool (2002-2007) were reviewed to determine the number of surgeries received, the anesthetic regime used, including amounts given, the total body surface area burned, and injury severity score. Morphine equivalent units were calculated using standard dosage conversion factors. The prevalence of PTSD in patients receiving ketamine during their operation(s) was compared with patients not receiving ketamine. Of the 25,000 soldiers injured in OIF/OEF, United States Army Institute of Surgical Research received 603 burned casualties, of which 241 completed the PCL-M. Of those, 147 soldiers underwent at least one operation. Among 119 patients who received ketamine during surgery and 28 who did not; the prevalence of PTSD was 27% (32 of 119) versus 46% (13 of 28), respectively (p = 0.044). Contrary to expectations, patients receiving perioperative ketamine had a lower prevalence of PTSD than soldiers receiving no ketamine during their surgeries despite having larger burns, higher injury severity score, undergoing more operations, and spending more time in the ICU.

Auricular burns associated with operating microscope use during otologic surgery.

PubMed

Latuska, Richard F; Carlson, Matthew L; Neff, Brian A; Driscoll, Colin L; Wanna, George B; Haynes, David S

2014-02-01

To raise awareness of the potential hazard of auricular burns associated with operating microscope use during otologic surgery. Retrospective case series and summary of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database of voluntary adverse event reports pertaining to microscope related auricular thermal injuries. All patients who sustained auricular burns while using the operating microscope during otologic surgery at 2 tertiary academic referral centers. Surgical procedure, microscope model, intensity of illumination, length of procedure, focal length, location and severity of burn, and patient outcome. A total of 4 microscope-related auricular thermal injuries were identified from the authors' institutions. Additionally, 82 unique cases of soft tissue burns associated with the use of an operative microscope have been voluntarily reported to the FDA since 2004. A disproportionately large percent (∼ 30%) of these occurred within the field of otology, the majority of which were during tympanoplasty or tympanomastoidectomy procedures at focal length distances of 300 mm or less with xenon light source microscopes. Simultaneous advancements in light delivery technologies and lens optics have continued to improve the efficiency of the operating microscope; however, these improvements also increase the potential for thermal injuries. Although rare, a review of the FDA MAUDE database suggests that microscope-related soft tissue burns occur more frequently in otology than any other surgical specialty. A variety of factors may help explain this finding, including the unique anatomy of the external ear with thin skin and limited underlying adipose tissue. Preventative measures should be taken to decrease the risk of thermal injuries including use of the lowest comfortable light intensity, adjusting the aperture width to match the operative field, frequent wound irrigation, and covering exposed portions of the pinna with a moist surgical sponge.

40 CFR 265.352 - Interim status incinerators burning particular hazardous wastes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Interim status incinerators burning... incinerators burning particular hazardous wastes. (a) Owners or operators of incinerators subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or FO27 if they receive a...

40 CFR 265.352 - Interim status incinerators burning particular hazardous wastes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Interim status incinerators burning... incinerators burning particular hazardous wastes. (a) Owners or operators of incinerators subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or FO27 if they receive a...

40 CFR 265.352 - Interim status incinerators burning particular hazardous wastes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Interim status incinerators burning... incinerators burning particular hazardous wastes. (a) Owners or operators of incinerators subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or FO27 if they receive a...

40 CFR 265.352 - Interim status incinerators burning particular hazardous wastes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Interim status incinerators burning... incinerators burning particular hazardous wastes. (a) Owners or operators of incinerators subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or FO27 if they receive a...

40 CFR 265.352 - Interim status incinerators burning particular hazardous wastes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Interim status incinerators burning... incinerators burning particular hazardous wastes. (a) Owners or operators of incinerators subject to this subpart may burn EPA Hazardous Wastes FO20, FO21, FO22, FO23, FO26, or FO27 if they receive a...

The Application of Lean Thinking to the Care of Patients With Bone and Brain Metastasis With Radiation Therapy

PubMed Central

Kim, Christopher S.; Hayman, James A.; Billi, John E.; Lash, Kathy; Lawrence, Theodore S.

2007-01-01

Purpose Patients with bone and brain metastases are among the most symptomatic nonemergency patients treated by radiation oncologists. Treatment should begin as soon as possible after the request is generated. We tested the hypothesis that the operational improvement method based on lean thinking could help streamline the treatment of our patients referred for bone and brain metastases. Methods University of Michigan Health System has adopted lean thinking as a consistent approach to quality and process improvement. We applied the principles and tools of lean thinking, especially value as defined by the customer, value stream mapping processes, and one piece flow, to improve the process of delivering care to patients referred for bone or brain metastases. Results and Conclusion The initial evaluation of the process revealed that it was rather chaotic and highly variable. Implementation of the lean thinking principles permitted us to improve the process by cutting the number of individual steps to begin treatment from 27 to 16 and minimize variability by applying standardization. After an initial learning period, the percentage of new patients with brain or bone metastases receiving consultation, simulation, and treatment within the same day rose from 43% to nearly 95%. By implementing the ideas of lean thinking, we improved the delivery of clinical care for our patients with bone or brain metastases. We believe these principles can be applied to much of the care administered throughout our and other health care delivery areas. PMID:20859409

Alterations of local cerebral glucose utilization in lean and obese fa/fa rats after acute adrenalectomy.

PubMed

Doyle, P; Rohner-Jeanrenaud, F; Jeanrenaud, B

1994-08-29

An animal model often used to investigate the aetiology of obesity is the genetically obese fa/fa rat. It has many abnormalities, including hyperphagia, hyper-insulinemia, insulin resistance, low cerebral glucose utilization and an overactive hypothalamo-pituitary adrenal (HPA) axis with resulting hypercorticism. Due to the latter consideration, the aim of this work was to study the impact of acute adrenalectomy (ADX) on the local cerebral glucose utilization (LCGU) of lean and obese fa/fa rats. ADX resulted in discrete increases in LCGU of regions common to both lean and obese rats. These common regions were found to belong to be related to the limbic system. Within this system, the LCGU of the brain of obese rats was either normalized to lean sham operated values or increased by ADX to a similar degree in both groups on a percentage basis. It was concluded that the LCGU of both lean and obese animals appears to be negatively regulated, albeit to different extents, by glucocorticoids. Such negative regulation is particularly salient within the limbic system of the lean rat and even more so in the fa/fa rat. It is suggested that the long-term hypercorticism of obese fa/fa rats due to abnormal regulation of the HPA axis may result in a decreased LCGU in limbic and related regions of the brain of fa/fa rats and contribute to the expression of the obese phenotype.

The application of lean thinking to the care of patients with bone and brain metastasis with radiation therapy.

PubMed

Kim, Christopher S; Hayman, James A; Billi, John E; Lash, Kathy; Lawrence, Theodore S

2007-07-01

Patients with bone and brain metastases are among the most symptomatic nonemergency patients treated by radiation oncologists. Treatment should begin as soon as possible after the request is generated. We tested the hypothesis that the operational improvement method based on lean thinking could help streamline the treatment of our patients referred for bone and brain metastases. University of Michigan Health System has adopted lean thinking as a consistent approach to quality and process improvement. We applied the principles and tools of lean thinking, especially value as defined by the customer, value stream mapping processes, and one piece flow, to improve the process of delivering care to patients referred for bone or brain metastases. The initial evaluation of the process revealed that it was rather chaotic and highly variable. Implementation of the lean thinking principles permitted us to improve the process by cutting the number of individual steps to begin treatment from 27 to 16 and minimize variability by applying standardization. After an initial learning period, the percentage of new patients with brain or bone metastases receiving consultation, simulation, and treatment within the same day rose from 43% to nearly 95%. By implementing the ideas of lean thinking, we improved the delivery of clinical care for our patients with bone or brain metastases. We believe these principles can be applied to much of the care administered throughout our and other health care delivery areas.

78 FR 7428 - Clean Air Act Operating Permit Program; Petition for Objection to State Operating Permit for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-01

... the March 28, 2011 petition, submitted by the Louisiana Environmental Action Network (LEAN), Sierra..., 2011 to Noranda Alumina, LLC, for the operation of the alumina production plant located in Gramercy, St... production plant in Gramercy, St. James Parish, Louisiana for the following reasons: (1) The Title V Permit...

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., the design and operating information required by § 270.66 must be provided for both the similar device and the device to which the data is to be applied, and a comparison of the design and operating... provided to support the contention that a trial burn is not needed; (B) The design and operating conditions...

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., the design and operating information required by § 270.66 must be provided for both the similar device and the device to which the data is to be applied, and a comparison of the design and operating... provided to support the contention that a trial burn is not needed; (B) The design and operating conditions...

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., the design and operating information required by § 270.66 must be provided for both the similar device and the device to which the data is to be applied, and a comparison of the design and operating... provided to support the contention that a trial burn is not needed; (B) The design and operating conditions...

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., the design and operating information required by § 270.66 must be provided for both the similar device and the device to which the data is to be applied, and a comparison of the design and operating... provided to support the contention that a trial burn is not needed; (B) The design and operating conditions...

40 CFR 270.22 - Specific part B information requirements for boilers and industrial furnaces burning hazardous...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., the design and operating information required by § 270.66 must be provided for both the similar device and the device to which the data is to be applied, and a comparison of the design and operating... provided to support the contention that a trial burn is not needed; (B) The design and operating conditions...

Effects of differential rates of alternative reinforcement on resurgence of human behavior.

PubMed

Smith, Brooke M; Smith, Gregory S; Shahan, Timothy A; Madden, Gregory J; Twohig, Michael P

2017-01-01

Despite the success of exposure-based psychotherapies in anxiety treatment, relapse remains problematic. Resurgence, the return of previously eliminated behavior following the elimination of an alternative source of reinforcement, is a promising model of operant relapse. Nonhuman resurgence research has shown that higher rates of alternative reinforcement result in faster, more comprehensive suppression of target behavior, but also in greater resurgence when alternative reinforcement is eliminated. This study investigated rich and lean rates of alternative reinforcement on response suppression and resurgence in typically developing humans. In Phase 1, three groups (Rich, n = 18; Lean, n = 18; Control, n = 10) acquired the target response. In Phase 2, target responding was extinguished and alternative reinforcement delivered on RI 1 s, RI 3 s, and extinction schedules, respectively. Resurgence was assessed during Phase 3 under extinction conditions for all groups. Target responding was suppressed most thoroughly in Rich and partially in Lean. Target responding resurged in the Rich and Lean groups, but not in the Control group. Between groups, resurgence was more pronounced in the Rich group than the Lean and Control groups. Clinical implications of these findings, including care on the part of clinicians when identifying alternative sources of reinforcement, are discussed. © 2017 Society for the Experimental Analysis of Behavior.

Estrogen has opposing effects on vascular reactivity in obese, insulin-resistant male Zucker rats

NASA Technical Reports Server (NTRS)

Brooks-Asplund, Esther M.; Shoukas, Artin A.; Kim, Soon-Yul; Burke, Sean A.; Berkowitz, Dan E.

2002-01-01

We hypothesized that estradiol treatment would improve vascular dysfunction commonly associated with obesity, hyperlipidemia, and insulin resistance. A sham operation or 17beta-estradiol pellet implantation was performed in male lean and obese Zucker rats. Maximal vasoconstriction (VC) to phenylephrine (PE) and potassium chloride was exaggerated in control obese rats compared with lean rats, but estradiol significantly attenuated VC in the obese rats. Estradiol reduced the PE EC50 in all groups. This effect was cyclooxygenase independent, because preincubation with indomethacin reduced VC response to PE similarly in a subset of control and estrogen-treated lean rats. Endothelium-independent vasodilation (VD) to sodium nitroprusside was similar among groups, but endothelium-dependent VD to ACh was significantly impaired in obese compared with lean rats. Estradiol improved VD in lean and obese rats by decreasing EC50 but impaired function by decreasing maximal VD. The shift in EC50 corresponded to an upregulation in nitric oxide synthase III protein expression in the aorta of the estrogen-treated obese rats. In summary, estrogen treatment improves vascular function in male insulin-resistant, obese rats, partially via an upregulation of nitric oxide synthase III protein expression. These effects are counteracted by adverse factors, such as hyperlipidemia and, potentially, a release of an endothelium-derived contractile agent.

Lean Six Sigma: a new approach to the management of patients undergoing prosthetic hip replacement surgery.

PubMed

Improta, Giovanni; Balato, Giovanni; Romano, Maria; Carpentieri, Francesco; Bifulco, Paolo; Alessandro Russo, Mario; Rosa, Donato; Triassi, Maria; Cesarelli, Mario

2015-08-01

In 2012, health care spending in Italy reached €114.5 billion, accounting for 7.2% of the Gross Domestic Product (GDP) and 14.2% of total public spending. Therefore, reducing waste in health facilities could generate substantial cost savings. The objective of this study is to show that Lean Six Sigma represents an appropriate methodology for the development of a clinical pathway which allows to improve quality and to reduce costs in prosthetic hip replacement surgery. The methodology used for the development of a new clinical pathway was Lean Six Sigma. Problem solving in Lean Six Sigma is the DMAIC (Define, Measure, Analyse, Improve, Control) roadmap, characterized by five operational phases which make possible to reach fixed goals through a rigorous process of defining, measuring, analysing, improving and controlling business problems. The following project indicated several variables influencing the inappropriate prolongation of the length of stay for inpatient treatment and corrective actions were performed to improve the effectiveness and efficiency of the process of care. The average length of stay was reduced from 18.9 to 10.6 days (-44%). This article shows there is no trade-off between quality and costs: Lean Six Sigma improves quality and, at the same time, reduces costs. © 2015 John Wiley & Sons, Ltd.

Kennedy Space Center Orion Processing Team Planning for Ground Operations

NASA Technical Reports Server (NTRS)

Letchworth, Gary; Schlierf, Roland

2011-01-01

Topics in this presentation are: Constellation Ares I/Orion/Ground Ops Elements Orion Ground Operations Flow Orion Operations Planning Process and Toolset Overview, including: 1 Orion Concept of Operations by Phase 2 Ops Analysis Capabilities Overview 3 Operations Planning Evolution 4 Functional Flow Block Diagrams 5 Operations Timeline Development 6 Discrete Event Simulation (DES) Modeling 7 Ground Operations Planning Document Database (GOPDb) Using Operations Planning Tools for Operability Improvements includes: 1 Kaizen/Lean Events 2 Mockups 3 Human Factors Analysis

MIT January Operational Internship Experience 2011

NASA Technical Reports Server (NTRS)

DeLatte, Danielle; Furhmann, Adam; Habib, Manal; Joujon-Roche, Cecily; Opara, Nnaemeka; Pasterski, Sabrina Gonzalez; Powell, Christina; Wimmer, Andrew

2011-01-01

This slide presentation reviews the 2011 January Operational Internship experience (JOIE) program which allows students to study operational aspects of spaceflight, how design affects operations and systems engineering in practice for 3 weeks. Topics include: (1) Systems Engineering (2) NASA Organization (3) Workforce Core Values (4) Human Factors (5) Safety (6) Lean Engineering (7) NASA Now (8) Press, Media, and Outreach and (9) Future of Spaceflight.

Results of a protocol of transfusion threshold and surgical technique on transfusion requirements in burn patients.

PubMed

O'Mara, Michael S; Hayetian, Fernando; Slater, Harvey; Goldfarb, I William; Tolchin, Eric; Caushaj, Philip F

2005-08-01

Blood loss and high rates of transfusion in burn centers remains an area of ongoing concern. Blood use brings the risk of infection, adverse reaction, and immunosuppression. A protocol to reduce blood loss and blood use was implemented. Analysis included 3-year periods before and after institution of the protocol. All patients were transfused for a hemoglobin below 8.0 gm/dL. Operations per admission did not change during the two time periods (0.78 in each). Overall units transfused per operation decreased from 1.56+/-0.06 to 1.25+/-0.14 units after instituting the protocol (p<0.05). Also, units transfused per admission decreased from 1.21+/-0.15 to 0.96+/-0.06 units of blood (p<0.05). This was noticed particularly in burns of less than 20% surface area, declining from 386 to 46 units after protocol institution, from 0.37 to 0.04 units per admission, and from 0.79 to 0.08 units per operation in this group of smallest burns. There was no change noted in the larger burns. This study suggests that a defined protocol of hemostasis, technique, and transfusion trigger should be implemented in the process of burn excision and grafting. This will help especially those patients with the smallest burns, essentially eliminating transfusion need in that group.

BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

Treesearch

Patricia L. Andrews

1986-01-01

Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

40 CFR 60.2972 - How must I monitor opacity for air curtain incinerators that burn only wood waste, clean lumber...

Code of Federal Regulations, 2012 CFR

2012-07-01

... curtain incinerators that burn only wood waste, clean lumber, and yard waste? 60.2972 Section 60.2972... PERFORMANCE FOR NEW STATIONARY SOURCES Operator Training and Qualification Air Curtain Incinerators That Burn... incinerators that burn only wood waste, clean lumber, and yard waste? (a) Use Method 9 of appendix A of this...

Potential impact of air quality restrictions on logging residue burning

Treesearch

Owen P. Cramer; James N. Westwood

1970-01-01

The number of potential burning days and the potential burn acreage under smoke control restrictions were estimated for hypothetical forest areas on both sides of a pollution prone area, the Willamette Valley in western Oregon. On the basis of a sample of 2 dry years, the greatest impact on burning operations applied to low elevation forests west of the Valley. The...

Measurement of Body Composition: is there a Gold Standard?

PubMed Central

Branski, Ludwik K; Norbury, William B; Herndon, David N; Chinkes, David L; Cochran, Amalia; Suman, Oscar; Benjamin, Deb; Jeschke, Marc G

2015-01-01

Background Maintaining lean body mass (LBM) after a severe burn is an essential goal of modern burn treatment. An accurate determination of LBM is necessary for short- and longterm therapeutic decisions. The aim of this study was to compare 2 measurement methods for body composition, wholebody potassium counting (K count) and dual x-ray absorptiometry (DEXA), in a large prospective clinical trial in severely burned pediatric patients. Methods Two-hundred seventy-nine patients admitted with burns covering 40% of total body surface area (TBSA) were enrolled in the study. Patients enrolled were controls or received long-term treatment with recombinant human growth hormone (rhGH). Near-simultaneous measurements of LBM with DEXA and fat-free mass (FFM) with K count were performed at hospital discharge and at 6, 9, 12, 18, and 24 months post injury. Results were correlated using Pearson’s regression analysis. Agreement between the 2 methods was analyzed with the Bland-Altman method. Results Age, gender distribution, weight, burn size, and admission time from injury were not significantly different between control and treatment groups. rhGH and control patients at all time points postburn showed a good correlation between LBM and FFM measurements (R2 between 0.9 and 0.95). Bland-Altman revealed that the mean bias and 95% limits of agreement depended only on patient weight and not on treatment or time postburn. The 95% limits ranged from 0.1 ± 2.9 kg for LBM or FFM in 7- to 18-kg patients to 16.3 ± 17.8 kg for LBM or FFM in patients >60 kg. Conclusions DEXA can provide a sufficiently accurate determination of LBM and changes in body composition, but a correction factor must be included for older children and adolescents with more LBM. DEXA scans are easier, cheaper, and less stressful for the patient, and this method should be used rather than the K count. PMID:19884353

Characterization of Swirl-Venturi Lean Direct Injection Designs for Aviation Gas-Turbine Combustion

NASA Technical Reports Server (NTRS)

Heath, Christopher M.

2013-01-01

Injector geometry, physical mixing, chemical processes, and engine cycle conditions together govern performance, operability and emission characteristics of aviation gas-turbine combustion systems. The present investigation explores swirl-venturi lean direct injection combustor fundamentals, characterizing the influence of key geometric injector parameters on reacting flow physics and emission production trends. In this computational study, a design space exploration was performed using a parameterized swirl-venturi lean direct injector model. From the parametric geometry, 20 three-element lean direct injection combustor sectors were produced and simulated using steady-state, Reynolds-averaged Navier-Stokes reacting computations. Species concentrations were solved directly using a reduced 18-step reaction mechanism for Jet-A. Turbulence closure was obtained using a nonlinear ?-e model. Results demonstrate sensitivities of the geometric perturbations on axially averaged flow field responses. Output variables include axial velocity, turbulent kinetic energy, static temperature, fuel patternation and minor species mass fractions. Significant trends have been reduced to surrogate model approximations, intended to guide future injector design trade studies and advance aviation gas-turbine combustion research.

Using Lean principles to manage throughput on an inpatient rehabilitation unit.

PubMed

Chiodo, Anthony; Wilke, Ruste; Bakshi, Rishi; Craig, Anita; Duwe, Doug; Hurvitz, Edward

2012-11-01

Performance improvement is a mainstay of operations management and maintenance of certification. In this study at a University Hospital inpatient rehabilitation unit, Lean management techniques were used to manage throughput of patients into and out of the inpatient rehabilitation unit. At the start of this process, the average admission time to the rehabilitation unit was 5:00 p.m., with a median time of 3:30 p.m., and no patients received therapy on the day of admission. Within 8 mos, the mean admission time was 1:22 p.m., 50% of the patients were on the rehabilitation unit by 1:00 p.m., and more than 70% of all patients received therapy on the day of admission. Negative variance from this performance was evaluated, the identification of inefficient discharges holding up admissions as a problem was identified, and a Lean workshop was initiated. Once this problem was tackled, the prime objective of 70% of patients receiving therapy on the date of admission was consistently met. Lean management tools are effective in improving throughput on an inpatient rehabilitation unit.

Epidemiology of operative burns at Kijabe Hospital from 2006 to 2010: Pilot study of a web-based tool for creation of the Kenya Burn Repository

PubMed Central

Dale, Elizabeth L.; Mueller, Melissa A.; Wang, Li; Fogerty, Mary D.; Guy, Jeffrey S.; Nthumba, Peter M.

2013-01-01

Introduction In order to implement effective burn prevention strategies, the WHO has called for improved data collection to better characterize burn injuries in low and middle income countries (LMIC). This study was designed to gather information on burn injury in Kenya and to test a model for such data collection. Methods The study was designed as a retrospective case series study utilizing an electronic data collection tool to assess the scope of burn injuries requiring operation at Kijabe Hospital from January 2006 to May 2010. Data were entered into a web-based tool to test its utility as the potential Kenya Burn Repository (KBR). Results 174 patients were included. The median age was 10 years. There was a male predominance (59% vs. 41%). Findings included that timing of presentation was associated with burn etiology (p = 0.009). Length of stay (LOS) was associated with burn etiology (p < 0.001). Etiology differed depending on the age group, with scald being most prominent in children (p = 0.002). Conclusions Burn injuries in Kenya show similarities with other LMIC in etiology and pediatric predominance. Late presentation for care and prolonged LOS are areas for further investigation. The web-based database is an effective tool for data collection and international collaboration. PMID:23040425

Epidemiology of operative burns at Kijabe Hospital from 2006 to 2010: pilot study of a web-based tool for creation of the Kenya Burn Repository.

PubMed

Dale, Elizabeth L; Mueller, Melissa A; Wang, Li; Fogerty, Mary D; Guy, Jeffrey S; Nthumba, Peter M

2013-06-01

In order to implement effective burn prevention strategies, the WHO has called for improved data collection to better characterize burn injuries in low and middle income countries (LMIC). This study was designed to gather information on burn injury in Kenya and to test a model for such data collection. The study was designed as a retrospective case series study utilizing an electronic data collection tool to assess the scope of burn injuries requiring operation at Kijabe Hospital from January 2006 to May 2010. Data were entered into a web-based tool to test its utility as the potential Kenya Burn Repository (KBR). 174 patients were included. The median age was 10 years. There was a male predominance (59% vs. 41%). Findings included that timing of presentation was associated with burn etiology (p=0.009). Length of stay (LOS) was associated with burn etiology (p<0.001). Etiology differed depending on the age group, with scald being most prominent in children (p=0.002). Burn injuries in Kenya show similarities with other LMIC in etiology and pediatric predominance. Late presentation for care and prolonged LOS are areas for further investigation. The web-based database is an effective tool for data collection and international collaboration. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

A patient who was burned in the operative field: a case report.

PubMed

Chung, Soo Ho; Lee, Hae Hyeog; Kim, Tae Hee; Kim, Jeong Sig

2012-05-01

Operating room fires occur very rarely. Nevertheless, a disaster can complicate almost any kind of surgery. The majority of operating room fires result from the use of alcohol- based surgical preparation solutions, electro-surgical equipment, or flammable drapes in an oxygen-rich environment. We report a patient with an ovarian cyst and uterine myomas who suffered a flame burn while undergoing gynecological surgery.

CHARACTERIZATION OF AIR EMISSIONS AND RESIDUAL ASH FROM OPEN BURNING OF ELECTRONIC WASTES DURING SIMULATED RUDIMENTALRY RECYCLING OPERATIONS

EPA Science Inventory

Air emissions and residual ash measurements were made from open, uncontrolled combustion of electronic waste (e-waste) during simulations of practices associated with rudimentary e-waste recycling operations. Circuit boards and insulated wires were separately burned to simulate p...

Effect of Air Swirler Configuration on Lean Direct Injector Flow Structure and Combustion Performance with a 7-Point Lean Direct Injector Array

NASA Technical Reports Server (NTRS)

Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2017-01-01

Studies of various injector configurations in a 7-point Lean Direct Injector (LDI) array are reported for both non-reacting (cold) flow and for Jet-A/air reacting flows. For cold flow, central recirculation zone (CRZ) formation is investigated and for reacting flows, combustor operability and dynamics are of interest. 2D Particle Image Velocimetry (PIV) measurements are described for the cold flow experiments and flame chemiluminescence imaging and dynamic pressure results are discussed for the reacting flow cases. PIV results indicate that for this configuration the close spacing between swirler elements leads to strong interaction that affects whether a CRZ forms, and pilot recess and counter-swirl helps to isolate swirlers from one another. Dynamics results focus on features identified near 500-Hz.

Stratospheric cruise emission reduction program

NASA Technical Reports Server (NTRS)

Diehl, L. A.; Reck, G. M.; Marek, C. J.; Szaniszlo, A. J.

1977-01-01

A recently implemented NASA effort specifically aimed at reducing cruise oxides of nitrogen from high-altitude aircraft is discussed. The desired emission levels and the combustor technology required to achieve them are discussed. A brief overview of the SCERP operating plan is given. Lean premixed-prevaporized combustion and some of the potential difficulties that are associated with applying this technique to gas turbine combustors are examined. Base technology was developed in several key areas. These fundamental studies are viewed as a requirement for successful implementation of the lean premixed combustion technique.

The Hand Burn Severity (HABS) score: A simple tool for stratifying severity of hand burns.

PubMed

Bache, Sarah E; Fitzgerald O'Connor, Edmund; Theodorakopoulou, Evgenia; Frew, Quentin; Philp, Bruce; Dziewulski, Peter

2017-02-01

Hand burns represent a unique challenge to the burns team due to the intricate structure and unrivalled functional importance of the hand. The initial assessment and prognosis relies on consideration of the specific site involved as well as depth of the burn. We created a simple severity score that could be used by referring non-specialists and researchers alike. The Hand Burn Severity (HABS) score stratifies hand burns according to severity with a numerical value of between 0 (no burn) and 18 (most severe) per hand. Three independent assessors scored the photographs of 121 burned hands of 106 adult and paediatric patients, demonstrating excellent inter-rater reliability (r=0.91, p<0.0001 on testing with Lin's correlation coefficient). A significant relationship was shown between the HABS score and a reliable binary outcome of the requirement for surgical excision on Mann-Whitney U testing (U=152; Z=9.8; p=0.0001). A receiver operator characteristic (ROC) curve analysis found a cut off score of 5.5, indicating that those with a HABS score below 6 did not require an operation, whereas those with a score above 6 did. The HABS score was shown to be more sensitive and specific that assessment of burn depth alone. The HABS score is a simple to use tool to stratify severity at initial presentation of hand burns which will be useful when referring, and when reporting outcomes. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Report From the California Burn Registry—The Causes of Major Burns

PubMed Central

Bongard, Frederic S.; Ostrow, Louis B.; Sacks, Susan T.; McGuire, Andrew; Trunkey, Donald D.

1985-01-01

In its first four years of operation, the California Burn Registry recorded 3,332 cases of burns, of which 73.1% were in male and 26.9% were in female patients of all ages. The average total body surface area burned was 15.4±0.3%. Flame burns were the most common (31.4%). Other common sources included scalds (24.5%) and flammable liquids (12.9%). Several other causes were cited with less frequency. Burns taking place at home occurred more commonly than at all other locations combined. In all, 221 deaths (6.6%) were reported, most (66.1%) of which were due to flame burns. PMID:4013280

Computational investigations of low-emission burner facilities for char gas burning in a power boiler

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

2016-04-01

Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

Lean Six Sigma in Healthcare: Combating the Military’s Escalating Pharmacy Costs

DTIC Science & Technology

2009-04-30

Management journal . Prior to his career in academia, Dr. Apte worked for over ten years in managing operations and information systems in the financial... journals including Management Science, Interfaces, Production and Operations Management , Journal of Operations Management , Decision Sciences, IIE...Telecommunication Management , Naval Logistics Quarterly, and other technical journals and conference proceedings. He has been involved in

A review of the peri-operative management of paediatric burns: Identifying adverse events.

PubMed

Rode, H; Brink, C; Bester, K; Coleman, M P; Baisey, T; Martinez, R

2016-11-02

Burn injuries are common in poverty-stricken countries. The majority of patients with large and complex burns are referred to burn centres. Of the children who qualify for admission, according to burn admission criteria, about half require some kind of surgical procedure to obtain skin cover. These range from massive full-thickness fire burns to skin grafts for small, residual unhealed wounds. Burn anaesthetic procedures are of the most difficult to perform and are known for high complication rates. Reasons include peri-operative sepsis, bleeding, issues around thermoregulation, the hypermetabolic state, nutritional and electrolyte issues, inhalation injuries and the amount of movement during procedures to wash patients, change drapes and access different anatomical sites. The appropriate execution of surgery is therefore of the utmost importance for both minor and major procedures. To review the peri-operative management and standard of surgical care of burnt children. This was a retrospective review and analysis of standard peri-operative care of burnt children at Red Cross War Memorial Children's Hospital, Cape Town, South Africa. A total of 558 children were operated on and supervised by the first author. Factors that could adversely affect surgical and anaesthetic outcomes were identified. There were 257 males and 301 females in this study, with an average age of 50.1 months and average weight of 19.5 kg. The total body surface area involved was 1 - 80%, with an average of 23.5%. Inhalational injury was present in 11.3%, pneumonia in 13.1%, wound sepsis in 20.8%, and septicaemia in 9.7%, and organ dysfunction in more than one organ was seen in 6.1%. The average theatre temperature during surgery was 30.0°C. Core temperatures recorded at the start, halfway through and at completion of surgery were 36.9°C, 36.8°C and 36.5°C, respectively. The average preoperative and postoperative haemoglobin levels were 11.28 g/dL and 9.64 g/dL, respectively. Blood loss was reduced by the use of clysis from 1.5 mL/kg/% burn to 1.4 mL/kg/% burn. Adverse intraoperative events were seen in 17.6% of children. Burn surgery is a high-risk procedure and comorbidities are common. Anaesthesia and surgery must be well planned and executed with special reference to temperature control, rapid blood loss, preceding respiratory illnesses and measures to reduce blood loss.

Operationally optimal maneuver strategy for spacecraft injected into sub-geosynchronous transfer orbit

NASA Astrophysics Data System (ADS)

Kiran, B. S.; Singh, Satyendra; Negi, Kuldeep

The GSAT-12 spacecraft is providing Communication services from the INSAT/GSAT system in the Indian region. The spacecraft carries 12 extended C-band transponders. GSAT-12 was launched by ISRO’s PSLV from Sriharikota, into a sub-geosynchronous Transfer Orbit (sub-GTO) of 284 x 21000 km with inclination 18 deg. This Mission successfully accomplished combined optimization of launch vehicle and satellite capabilities to maximize operational life of the s/c. This paper describes mission analysis carried out for GSAT-12 comprising launch window, orbital events study and orbit raising maneuver strategies considering various Mission operational constraints. GSAT-12 is equipped with two earth sensors (ES), three gyroscopes and digital sun sensor. The launch window was generated considering mission requirement of minimum 45 minutes of ES data for calibration of gyros with Roll-sun-pointing orientation in T.O. Since the T.O. period was a rather short 6.1 hr, required pitch biases were worked out to meet the gyro-calibration requirement. A 440 N Liquid Apogee Motor (LAM) is used for orbit raising. The objective of the maneuver strategy is to achieve desired drift orbit satisfying mission constraints and minimizing propellant expenditure. In case of sub-GTO, the optimal strategy is to first perform an in-plane maneuver at perigee to raise the apogee to synchronous level and then perform combined maneuvers at the synchronous apogee to achieve desired drift orbit. The perigee burn opportunities were examined considering ground station visibility requirement for monitoring the burn. Two maneuver strategies were proposed: an optimal five-burn strategy with two perigee burns centered around perigee#5 and perigee#8 with partial ground station visibility and three apogee burns with dual station visibility, a near-optimal five-burn strategy with two off-perigee burns at perigee#5 and perigee#8 with single ground station visibility and three apogee burns with dual station visibility. The range vector profiles were studied in the s/c frame during LAM burn phases and accurate polarization predictions were provided to supporting ground stations. The near optimal strategy was selected for implementation in order to ensure full visibility during each LAM burn. Contingency maneuver plans were generated in preparation for specified Propulsion system related contingencies. Maneuver plans were generated considering 3-sigma dispersions in T.O. GSAT-12 is positioned at 83 deg East longitude. The estimated operational life is about 11 years which was realized through operationally optimal maneuver strategy selected from the detailed mission analysis.

Lean Premixed Combustion Stabilized by Low Swirl a Promising Concept for Practical Applications

NASA Technical Reports Server (NTRS)

Cheng, R. K.

1999-01-01

Since its inception, the low-swirl burner (LSB) has shown to be a useful laboratory apparatus for fundamental studies of premixed turbulent flames. The LSB operates under wide ranges of equivalence ratios, flow rates, and turbulence intensities. Its flame is lifted and detached from the burner and allows easy access for laser diagnostics. The flame brush is axisymmetric and propagates normal to the incident reactants. Therefore, the LSB is well suited for investigating detailed flame structures and empirical coefficients such as flame speed, turbulence transport, and flame generated turbulence. Due to its capability to stabilize ultra-lean premixed turbulent flames (phi approx. = 0.55), the LSB has generated interest from the gas appliance industry for use as an economical low-NO(x) burner. Lean premixed combustion emits low levels of NO(x), due primarily to the low flame temperature. Therefore, it is a very effective NO(x) prevention method without involving selective catalytic reduction (SCR), fuel-air staging, or flue gas recirculation (FGR). En the gas turbine industry, substantial research efforts have already been undertaken and engines with lean premixed combustors are already in use. For commercial and residential applications, premixed pulsed combustors and premixed ceramic matrix burners are commercially available. These lean premixed combustion technologies, however, tend to be elaborate but have relatively limited operational flexibility, and higher capital, operating and maintenance costs. Consequently, these industries are continuing the development of lean premixed combustion technologies as well as exploring new concepts. This paper summarizes the research effects we have undertaken in the past few years to demonstrate the feasibility of applying the low-swirl flame stabilization method for a wide range of heating and power generation systems. The principle of flame stabilization by low-swirl is counter to the conventional high-swirl methods that rely on a recirculation zone to anchor the flame. In LSBS, flow recirculation is not promoted to allow the premixed turbulent flames to propagate freely. A LSB with an air-jet swirler is essentially an open tube with the swirler at its mid section. The small air-jets generate swirling motion only in the annular region and leaving the central core of the flow undisturbed, When this flow exits the burner tube, the angular momentum generates radial mean pressure gradient to diverge the non-swirling reactants stream. Consequently, the mean flow velocity decreases linearly. Propagating against this decelerating flow, the flame self-sustains at the position where the local flow velocity equals the flame speed, S(sub f). The LSB operates with a swirl number, S, between 0.02 to 0.1. This is much lower than the minimum S of 0.6 required for the high-swirl burners. We found that the swirl number needed for flame stabilization varies only slightly with fuel type, flow velocity, turbulent conditions and burner dimensions (i.e. throat diameter and swirl injection angle).

An epidemiological analysis of paediatric burns in urban and rural areas in south central China.

PubMed

Zhou, Bo; Zhou, Xiao; Ouyang, Li-zhi; Huang, Xiao-yuan; Zhang, Pi-hong; Zhang, Ming-hua; Ren, Li-cheng; Liang, Peng-fei

2014-02-01

This study aims to analyse the epidemiology of paediatric burns in south central China, illustrate the differences between rural and urban areas, and discern prevention measures to reduce paediatric burns. Data were obtained from all paediatric patients admitted to Department of Burns unit of Xiangya Hospital during 2009-2012. A retrospective review was performed, including cause of burn, pre-hospital treatment, place of burn occurrence, anatomical areas involved, extent of burn, date of injury, number of operations, complications, length of hospital stay, hospitalisation cost and cure rate. A total of 278 hospitalised paediatric patients were admitted in this study. The majority (56.47%) were 1-3 years old. Rural patients accounted for 67.99% in total; the ratio of boys to girls was 2.05. Scalding with hot fluids was the most common cause of burns in children (62.59%), followed by flame (17.63), fireworks (9.71%), electricity (5.76%) and other factors such as contact and chemical (4.32%). The living room was the location with the highest frequency of burns in children (53.24%). Burns were more likely to happen in winter and the upper extremities were the most involved anatomic site (53.24%). Total burn surface area (TBSA) ranging from 0% to 9% accounted for 55.4% in total. Rural patients underwent more operations and had longer and costlier hospital stays than urban patients. Compared with treatment in urban areas, rural burn patients received less first-aid treatment, underwent more surgery, had more complications and longer and more costly hospital stays. This finding strongly suggests that it is necessary to make more efforts to prevent burns, especially in rural areas. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Diet-induced obesity, energy metabolism and gut microbiota in C57BL/6J mice fed Western diets based on lean seafood or lean meat mixtures.

PubMed

Holm, Jacob Bak; Rønnevik, Alexander; Tastesen, Hanne Sørup; Fjære, Even; Fauske, Kristin Røen; Liisberg, Ulrike; Madsen, Lise; Kristiansen, Karsten; Liaset, Bjørn

2016-05-01

High protein diets may protect against diet-induced obesity, but little is known regarding the effects of different protein sources consumed at standard levels. We investigated how a mixture of lean seafood or lean meat in a Western background diet modulated diet-induced obesity, energy metabolism and gut microbiota. Male C57BL/6J mice fed a Western diet (WD) containing a mixture of lean seafood (seafood WD) for 12weeks accumulated less fat mass than mice fed a WD containing a mixture of lean meat (meat WD). Meat WD-fed mice exhibited increased fasting blood glucose, impaired glucose clearance, elevated fasting plasma insulin and increased plasma and liver lipid levels. We observed no first choice preference for either of the WDs, but over time, mice fed the seafood WD consumed less energy than mice fed the meat WD. Mice fed the seafood WD exhibited higher spontaneous locomotor activity and a lower respiratory exchange ratio (RER) than mice fed the meat WD. Thus, higher activity together with the decreased energy intake contributed to the different phenotypes observed in mice fed the seafood WD compared to mice fed the meat WD. Comparison of the gut microbiomes of mice fed the two WDs revealed significant differences in the relative abundance of operational taxonomic units (OTUs) belonging to the orders Bacteroidales and Clostridiales, with genes involved in metabolism of aromatic amino acids exhibiting higher relative abundance in the microbiomes of mice fed the seafood WD. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimizing the CSP Tower Air Brayton Cycle System to Meet the SunShot Objectives - Final Technical Report

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

Bryner, Elliott; Brun, Klaus; Coogan, Shane

The objective of this project is to increase Concentrated Solar Power (CSP) tower air receiver and gas turbine temperature capabilities to 1,000ºC by the development of a novel gas turbine combustor, which can be integrated on a megawatt-scale gas turbine, such as the Solar Turbines Mercury 50™. No combustor technology currently available is compatible with the CSP application target inlet air temperature of 1,000°C. Autoignition and flashback at this temperature prevent the use of conventional lean pre-mix injectors that are currently employed to manage NOx emissions. Additional challenges are introduced by the variability of the high-temperature heat source provided bymore » the field of solar collectors, the heliostat in CSP plants. For optimum energy generation from the power turbine, the turbine rotor inlet temperature (TRIT) should remain constant. As a result of changing heat load provided to the solar collector from the heliostat, the amount of energy input required from the combustion system must be adjusted to compensate. A novel multi-bank lean micro-mix injector has been designed and built to address the challenges of high-temperature combustion found in CSP applications. The multi-bank arrangement of the micro-mix injector selectively injects fuel to meet the heat addition requirements to maintain constant TRIT with changing solar load. To validate the design, operation, and performance of the multi-bank lean micro-mix injector, a novel combustion test facility has been designed and built at Southwest Research Institute® (SwRI®) in San Antonio, TX. This facility, located in the Turbomachinery Research Facility, provides in excess of two kilograms per second of compressed air at nearly eight bar pressure. A two-megawatt electric heater raises the inlet temperature to 800°C while a secondary gas-fired heater extends the operational temperature range of the facility to 1,000°C. A combustor test rig connected to the heater has been designed and built to test the multi-bank lean micro-mix injector over the range of CSP operating conditions. The fuel is controlled and selectively delivered to the banks of the injector based on combustor inlet conditions that correspond to turbine operating points. The combustor rig is equipped with a data acquisition system and a suite of instrumentation for measuring temperature, pressure, and species concentration. This unique test facility has been built and commissioned and a prototype of the multi-bank lean micro-mix injector design has been tested. Operation of the combustor and injector has been demonstrated over the full range of CSP inlet conditions and for the range of turbine load conditions specified. The multi-bank operation of the injector has been proven to be an effective design for managing the variable flow rates of air and fuel due to changing inlet conditions from the solar field and turbine loads.« less

Prospective assessment of chronic multisymptom illness reporting possibly associated with open-air burn pit smoke exposure in Iraq.

PubMed

Powell, Teresa M; Smith, Tyler C; Jacobson, Isabel G; Boyko, Edward J; Hooper, Tomoko I; Gackstetter, Gary D; Phillips, Christopher J; Smith, Besa

2012-06-01

To investigate the relationship between chronic multisymptom illness (CMI) and possible exposure to an open-air burn pit at three selected bases among those deployed to operations in Iraq and Afghanistan. Chronic multisymptom illness (reporting at least one symptom in at least two of the following symptom constructs: general fatigue; mood and cognition problems; and musculoskeletal discomfort) was assessed, differentiating by potential burn pit exposure, among deployers who completed 2004 and 2007 Millennium Cohort questionnaires. More than 21,000 Cohort participants were deployed in support of the current operations, including more than 3000 participants with at least one deployment within a 3-mile radius of a documented burn pit. After adjusting for covariates, no elevated risk of CMI was observed among those exposed. There was no increase in CMI symptom reporting in those deployed to three selected bases with documented burn pits compared with other deployers.

10 CFR Appendix D to Part 52 - Design Certification Rule for the AP1000 Design

Code of Federal Regulations, 2014 CFR

2014-01-01

... under 10 CFR 50.90. (1) Maximum fuel rod average burn-up. (2) Fuel principal design requirements. (3... Cases. (3) Design Summary of Critical Sections. (4) American Concrete Institute (ACI) 318, ACI 349... control system, except burn-up limit. (8) Motor-operated and power-operated valves. (9) Instrumentation...

10 CFR Appendix D to Part 52 - Design Certification Rule for the AP1000 Design

Code of Federal Regulations, 2012 CFR

2012-01-01

... under 10 CFR 50.90. (1) Maximum fuel rod average burn-up. (2) Fuel principal design requirements. (3... Cases. (3) Design Summary of Critical Sections. (4) American Concrete Institute (ACI) 318, ACI 349... control system, except burn-up limit. (8) Motor-operated and power-operated valves. (9) Instrumentation...

10 CFR Appendix D to Part 52 - Design Certification Rule for the AP1000 Design

Code of Federal Regulations, 2013 CFR

2013-01-01

... under 10 CFR 50.90. (1) Maximum fuel rod average burn-up. (2) Fuel principal design requirements. (3... Cases. (3) Design Summary of Critical Sections. (4) American Concrete Institute (ACI) 318, ACI 349... control system, except burn-up limit. (8) Motor-operated and power-operated valves. (9) Instrumentation...

Investigating the role of capacitive coupling between the operating table and the return electrode of an electrosurgery unit in the modification of the current density distribution within the patients' body.

PubMed

Bifulco, Paolo; Massa, Rita; Cesarelli, Mario; Romano, Maria; Fratini, Antonio; Gargiulo, Gaetano D; McEwan, Alistair L

2013-08-12

Electrosurgery units are widely employed in modern surgery. Advances in technology have enhanced the safety of these devices, nevertheless, accidental burns are still regularly reported. This study focuses on possible causes of sacral burns as complication of the use of electrosurgery. Burns are caused by local densifications of the current, but the actual pathway of current within patient's body is unknown. Numerical electromagnetic analysis can help in understanding the issue. To this aim, an accurate heterogeneous model of human body (including seventy-seven different tissues), electrosurgery electrodes, operating table and mattress was build to resemble a typical surgery condition. The patient lays supine on the mattress with the active electrode placed onto the thorax and the return electrode on his back. Common operating frequencies of electrosurgery units were considered. Finite Difference Time Domain electromagnetic analysis was carried out to compute the spatial distribution of current density within the patient's body. A differential analysis by changing the electrical properties of the operating table from a conductor to an insulator was also performed. Results revealed that distributed capacitive coupling between patient body and the conductive operating table offers an alternative path to the electrosurgery current. The patient's anatomy, the positioning and the different electromagnetic properties of tissues promote a densification of the current at the head and sacral region. In particular, high values of current density were located behind the sacral bone and beneath the skin. This did not occur in the case of non-conductive operating table. Results of the simulation highlight the role played from capacitive couplings between the return electrode and the conductive operating table. The concentration of current density may result in an undesired rise in temperature, originating burns in body region far from the electrodes. This outcome is concordant with the type of surgery-related sacral burns reported in literature. Such burns cannot be immediately detected after surgery, but appear later and can be confused with bedsores. In addition, the dosimetric analysis suggests that reducing the capacity coupling between the return electrode and the operating table can decrease or avoid this problem.

Reliability enhancement through optimal burn-in

NASA Astrophysics Data System (ADS)

Kuo, W.

1984-06-01

A numerical reliability and cost model is defined for production line burn-in tests of electronic components. The necessity of burn-in is governed by upper and lower bounds: burn-in is mandatory for operation-critical or nonreparable component; no burn-in is needed when failure effects are insignificant or easily repairable. The model considers electronic systems in terms of a series of components connected by a single black box. The infant mortality rate is described with a Weibull distribution. Performance reaches a steady state after burn-in, and the cost of burn-in is a linear function for each component. A minimum cost is calculated among the costs and total time of burn-in, shop repair, and field repair, with attention given to possible losses in future sales from inadequate burn-in testing.

46 CFR 114.600 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... supplement—Safety Glazing Materials For Glazing Motor Vehicles Operating on Land Highways 116.1030 American... Test Method for Rate of Burning and/or Extent and Time of Burning of Plastics in a Horizontal Position... Burning Characteristics of Building Materials 116.405; 116.422; 116.423 ASTM E 648-97, Standard Test...

Effects of fuel cetane number on the structure of diesel spray combustion: An accelerated Eulerian stochastic fields method

NASA Astrophysics Data System (ADS)

Jangi, Mehdi; Lucchini, Tommaso; Gong, Cheng; Bai, Xue-Song

2015-09-01

An Eulerian stochastic fields (ESF) method accelerated with the chemistry coordinate mapping (CCM) approach for modelling spray combustion is formulated, and applied to model diesel combustion in a constant volume vessel. In ESF-CCM, the thermodynamic states of the discretised stochastic fields are mapped into a low-dimensional phase space. Integration of the chemical stiff ODEs is performed in the phase space and the results are mapped back to the physical domain. After validating the ESF-CCM, the method is used to investigate the effects of fuel cetane number on the structure of diesel spray combustion. It is shown that, depending of the fuel cetane number, liftoff length is varied, which can lead to a change in combustion mode from classical diesel spray combustion to fuel-lean premixed burned combustion. Spray combustion with a shorter liftoff length exhibits the characteristics of the classical conceptual diesel combustion model proposed by Dec in 1997 (http://dx.doi.org/10.4271/970873), whereas in a case with a lower cetane number the liftoff length is much larger and the spray combustion probably occurs in a fuel-lean-premixed mode of combustion. Nevertheless, the transport budget at the liftoff location shows that stabilisation at all cetane numbers is governed primarily by the auto-ignition process.

A Comparative Study of Cycle Variability of Laser Plug Ignition vs Classical Spark Plug Ignition in Combustion Engines

NASA Astrophysics Data System (ADS)

Done, Bogdan

2017-10-01

Over the past 30 years numerous studies and laboratory experiments have researched the use of laser energy to ignite gas and fuel-air mixtures. The actual implementation of this laser application has still to be fully achieved in a commercial automotive application. Laser Plug Ignition as a replacement for Spark Plug Ignition in the internal combustion engines of automotive vehicles, offers several potential benefits such as extending lean burn capability, reducing the cyclic variability between combustion cycles and decreasing the total amount of ignition costs, and implicitly weight and energy requirements. The paper presents preliminary results of cycle variability study carried on a SI Engine equipped with laser Plug Ignition system. Versus classic ignition system, the use of the laser Plug Ignition system assures the reduction of the combustion process variability, reflected in the lower values of the coefficient of variability evaluated for indicated mean effective pressure, maximum pressure, maximum pressure angle and maximum pressure rise rate. The laser plug ignition system was mounted on an experimental spark ignition engine and tested at the regime of 90% load and 2800 rev/min, at dosage of λ=1.1. Compared to conventional spark plug, laser ignition assures the efficiency at lean dosage.

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.

A Unique, Optically Accessible Flame Tube Facility for Lean Combustor Studies

NASA Technical Reports Server (NTRS)

Hicks, Yolanda R.; Locke, Randy J.; Wey, Chowen C.; Bianco, Jean

1995-01-01

A facility that allows interrogation of combusting flows by advanced diagnostic methods and instrumentation has been developed at the NASA Lewis Research Center. An optically accessible flame tube combustor is described which has high temperature, pressure, and air flow capabilities. The windows in the combustor measure 3.8 cm axially by 5.1 cm radially, providing 67% optical access to the 7.6 cm x 7.6 cm cross section flow chamber. Advanced gas analysis instrumentation is available through a gas chromatography/mass spectrometer system (GC/MS), which has on-line capability for heavy hydrocarbon measurement with resolution to the parts per billion level. The instrumentation allows one to study combusting flows and combustor subcomponents, such as fuel injectors and air swirlers. Planar Laser Induced Fluorescence (PLIF) can measure unstable combustion species, which cannot be obtained with traditional gas sampling. This type of data is especially useful to combustion modellers. The optical access allows measurements to have high spatial and temporal resolution. GC/MS data and PLIF images of OH- are presented from experiments using a lean direct injection (LDI) combustor burning Jet-A fuel at inlet temperatures ranging from 810 K to 866 K, combustor pressures up to 1380 kPa, and equivalence ratios from 0.41 to 0.59.

Three-dimensional direct numerical simulation of turbulent lean premixed methane combustion with detailed kinetics

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

Aspden, A. J.; Day, M. S.; Bell, J. B.

The interaction of maintained homogeneous isotropic turbulence with lean premixed methane flames is investigated using direct numerical simulation with detailed chemistry. The conditions are chosen to be close to those found in atmospheric laboratory experiments. As the Karlovitz number is increased from 1 to 36, the preheat zone becomes thickened, while the reaction zone remains largely unaffected. A negative correlation of fuel consumption with mean flame surface curvature is observed. With increasing turbulence intensity, the chemical composition in the preheat zone tends towards that of an idealised unity Lewis number flame, which we argue is the onset of the transitionmore » to distributed burning, and the response of the various chemical species is shown to fall into broad classes. Smaller-scale simulations are used to isolate the specific role of species diffusion at high turbulent intensities. Diffusion of atomic hydrogen is shown to be related to the observed curvature correlations, but does not have significant consequential impact on the thickening of the preheat zone. It is also shown that susceptibility of the preheat zone to thickening by turbulence is related to the 'global' Lewis number (the Lewis number of the deficient reactant); higher global Lewis number flames tend to be more prone to thickening.« less

Three-dimensional direct numerical simulation of turbulent lean premixed methane combustion with detailed kinetics

DOE PAGES

Aspden, A. J.; Day, M. S.; Bell, J. B.

2016-02-18

The interaction of maintained homogeneous isotropic turbulence with lean premixed methane flames is investigated using direct numerical simulation with detailed chemistry. The conditions are chosen to be close to those found in atmospheric laboratory experiments. As the Karlovitz number is increased from 1 to 36, the preheat zone becomes thickened, while the reaction zone remains largely unaffected. A negative correlation of fuel consumption with mean flame surface curvature is observed. With increasing turbulence intensity, the chemical composition in the preheat zone tends towards that of an idealised unity Lewis number flame, which we argue is the onset of the transitionmore » to distributed burning, and the response of the various chemical species is shown to fall into broad classes. Smaller-scale simulations are used to isolate the specific role of species diffusion at high turbulent intensities. Diffusion of atomic hydrogen is shown to be related to the observed curvature correlations, but does not have significant consequential impact on the thickening of the preheat zone. It is also shown that susceptibility of the preheat zone to thickening by turbulence is related to the 'global' Lewis number (the Lewis number of the deficient reactant); higher global Lewis number flames tend to be more prone to thickening.« less

[Improving a hospital's supply chain through lean management].

PubMed

Aguilar-Escobar, V G; Garrido-Vega, P; Godino-Gallego, N

2013-01-01

Supply management is an area where hospitals have significant opportunities for improvement. The main objective of this paper has been to analyze how the application of Lean principles can improve logistics costs and user satisfaction. In connection with satisfaction, it also aimed to examine which aspects of the service define it and check for differences between different groups of users. The results of an experience to reorganize the hospital logistic system based on some Lean principles have been studied. This is therefore a case study, which combine different methods of data collection. The logistics cost calculation was carried out using the full costing method. To measure satisfaction of healthcare personnel, the internal logistics service users, an anonymous survey was conducted. Processing of the data obtained from the survey have included exploratory analysis, factor analysis and ANOVAs. The data have showed an improvement in logistics management after the implementation of Lean principles. Logistics costs were reduced and the satisfaction level of the internal users with the new logistics system was increased. Some differences in the degree of satisfaction by different groups of users were also detected, although they did not seem to distinguish between different aspects of logistic service. The analyzed experience shows the applicability and suitability of Lean principles to improve logistics operational costs and increase user satisfaction. Copyright © 2012 SECA. Published by Elsevier Espana. All rights reserved.

FY2015 Annual Report for Alternative Fuels DISI Engine Research.

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

Sjöberg, Carl-Magnus G.

2016-01-01

Climate change and the need to secure energy supplies are two reasons for a growing interest in engine efficiency and alternative fuels. This project contributes to the science-base needed by industry to develop highly efficient DISI engines that also beneficially exploit the different properties of alternative fuels. Our emphasis is on lean operation, which can provide higher efficiencies than traditional non-dilute stoichiometric operation. Since lean operation can lead to issues with ignition stability, slow flame propagation and low combustion efficiency, we focus on techniques that can overcome these challenges. Specifically, fuel stratification is used to ensure ignition and completeness ofmore » combustion but has soot- and NOx- emissions challenges. For ultralean well-mixed operation, turbulent deflagration can be combined with controlled end-gas auto-ignition to render mixed-mode combustion that facilitates high combustion efficiency. However, the response of both combustion and exhaust emissions to these techniques depends on the fuel properties. Therefore, to achieve optimal fuel-economy gains, the engine combustion-control strategies must be adapted to the fuel being utilized.« less

Wide range operation of advanced low NOx combustors for supersonic high-altitude aircraft gas turbines

NASA Technical Reports Server (NTRS)

Roberts, P. B.; Fiorito, R. J.

1977-01-01

An initial rig program tested the Jet Induced Circulation (JIC) and Vortex Air Blast (VAB) systems in small can combustor configurations for NOx emissions at a simulated high altitude, supersonic cruise condition. The VAB combustor demonstrated the capability of meeting the NOx goal of 1.0 g NO2/kg fuel at the cruise condition. In addition, the program served to demonstrate the limited low-emissions range available from the lean, premixed combustor. A follow-on effort was concerned with the problem of operating these lean, premixed combustors with acceptable emissions at simulated engine idle conditions. Various techniques have been demonstrated that allow satisfactory operation on both the JIC and VAB combustors at idle with CO emissions below 20 g/kg fuel. The VAB combustor was limited by flashback/autoignition phenomena at the cruise conditions to a pressure of 8 atmospheres. The JIC combustor was operated up to the full design cruise pressure of 14 atmospheres without encountering an autoignition limitation although the NOx levels, in the 2-3 g NO2/kg fuel range, exceeded the program goal.

Application of controllable pulverized-coal rich/lean combustion technology at the Hebi Wanhe Power Generation Co. Ltd.

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

Jianzhong, L.; Xiang, Z.; Junhu, Z.

1999-07-01

The No.2 unit (670/H, 200MW) at Hebi Wanhe Power Generation C o. Ltd., was put into use in 1992. This is a coal-fired boiler with tangential fired method. The design coal is Hebi lean coal. To stabilize the combustion without oil at low load, eight original designed burners placed to No. 2 and 3 level on the No.2 boiler were replaced with the controllable pulverized rich/lean ones developed by the Institute for Thermal Power Engineering (ITPE) of Zhejiang University. The practice of successive operation shows that stable combustion can be achieved at 50% load without support oil, even at 45%more » load. The combustible matter in fly ash decreased to 1.12% and 1.17% from 1.83% and 1.32%, respectively at full load (200MW) and half load (100MW). The application has obvious economic benefits.« less

Modern Management Principles Come to the Dental School.

PubMed

Wataha, John C; Mouradian, Wendy E; Slayton, Rebecca L; Sorensen, John A; Berg, Joel H

2016-04-01

The University of Washington School of Dentistry may be the first dental school in the nation to apply lean process management principles as a primary tool to re-engineer its operations and curriculum to produce the dentist of the future. The efficiencies realized through re-engineering will better enable the school to remain competitive and viable as a national leader of dental education. Several task forces conducted rigorous value stream analyses in a highly collaborative environment led by the dean of the school. The four areas undergoing evaluation and re-engineering were organizational infrastructure, organizational processes, curriculum, and clinic operations. The new educational model was derived by thoroughly analyzing the current state of dental education in order to design and achieve the closest possible ideal state. As well, the school's goal was to create a lean, sustainable operational model. This model aims to ensure continued excellence in restorative dental instruction and to serve as a blueprint for other public dental schools seeking financial stability in this era of shrinking state support and rising costs.

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

Fuel-rich catalytic combustion of Jet-A fuel-equivalence ratios 5.0 to 8.0

NASA Technical Reports Server (NTRS)

Brabbs, Theodore A.; Gracia-Salcedo, Carmen M.

1989-01-01

Fuel-rich catalytic combustion (E.R. greater than 5.0) is a unique technique for preheating a hydrocarbon fuel to temperatures much higher than those obtained by conventional heat exchangers. In addition to producing very reactive molecules, the process upgrades the structure of the fuel by the formation of hydrogen and smaller hydrocarbons and produces a cleaner burning fuel by removing some of the fuel carbon from the soot formation chain. With fuel-rich catalytic combustion as the first stage of a two stage combustion system, enhanced fuel properties can be utilized by both high speed engines, where time for ignition and complete combustion is limited, and engines where emission of thermal NO sub x is critical. Two-stage combustion (rich-lean) has been shown to be effective for NO sub x reduction in stationary burners where residence times are long enough to burn-up the soot formed in the first stage. Such residence times are not available in aircraft engines. Thus, the soot-free nature of the present process is critical for high speed engines. The successful application of fuel-rich catalytic combustion to Jet-A, a multicomponent fuel used in gas turbine combustors, is discusssed.

Modeling and Simulation of Swirl Stabilized Turbulent Non-Premixed Flames

NASA Astrophysics Data System (ADS)

Badillo-Rios, Salvador; Karagozian, Ann

2017-11-01

Flame stabilization is an important design criterion for many combustion chambers, especially at lean conditions and/or high power output, where insufficient stabilization can result in dangerous oscillations and noisy or damaged combustors. At high flow rates, swirling flow can offer a suitable stabilization mechanism, although understanding the dynamics of swirl-stabilized turbulent flames remains a significant challenge. Utilizing the General Equation and Mesh Solver (GEMS) code, which solves the Navier-Stokes equations along with the energy equation and five species equations, 2D axisymmetric and full 3D parametric studies and simulations are performed to guide the design and development of an experimental swirl combustor configuration and to study the effects of swirl on statistically stationary combustion. Results show that as the momentum of air is directed into the inner air inlet rather than the outer inlet of the swirl combustor, the central recirculating region becomes stronger and more unsteady, improving mixing and burning efficiency in that region. A high temperature region is found to occur as a result of burning of the trapped fuel from the central toroidal vortex. The effects of other parameters on flowfield and flame-stabilization dynamics are explored. Supported by ERC, Inc. (PS150006) and AFOSR (Dr. Chiping Li).

Assessing Jet-Induced Spatial Mixing in a Rich, Reacting Crossflow

NASA Technical Reports Server (NTRS)

Demayo, T. N.; Leong, M. Y.; Samuelsen, G. S.

2004-01-01

In many advanced low NOx gas turbine combustion techniques, such as rich-burn/quick-mix/lean-burn (RQL), jet mixing in a reacting, hot, fuel-rich crossflow plays an important role in minimizing all pollutant emissions and maximizing combustion efficiency. Assessing the degree of mixing and predicting jet penetration is critical to the optimization of the jet injection design strategy. Different passive scalar quantities, including carbon, oxygen, and helium are compared to quantify mixing in an atmospheric RQL combustion rig under reacting conditions. The results show that the O2-based jet mixture fraction underpredicts the C-based mixture fraction due to jet dilution and combustion, whereas the He tracer overpredicts it possibly due to differences in density and diffusivity. The He-method also exhibits significant scatter in the mixture fraction data that can most likely be attributed to differences in gas density and turbulent diffusivity. The jet mixture fraction data were used to evaluate planar spatial unmixedness, which showed good agreement for all three scalars. This investigation suggests that, with further technique refinement, O2 or a He tracer could be used instead of C to determine the extent of reaction and mixing in an RQL combustor.

Load compensation in a lean burn natural gas vehicle

NASA Astrophysics Data System (ADS)

Gangopadhyay, Anupam

A new multivariable PI tuning technique is developed in this research that is primarily developed for regulation purposes. Design guidelines are developed based on closed-loop stability. The new multivariable design is applied in a natural gas vehicle to combine idle and A/F ratio control loops. This results in better recovery during low idle operation of a vehicle under external step torques. A powertrain model of a natural gas engine is developed and validated for steady-state and transient operation. The nonlinear model has three states: engine speed, intake manifold pressure and fuel fraction in the intake manifold. The model includes the effect of fuel partial pressure in the intake manifold filling and emptying dynamics. Due to the inclusion of fuel fraction as a state, fuel flow rate into the cylinders is also accurately modeled. A linear system identification is performed on the nonlinear model. The linear model structure is predicted analytically from the nonlinear model and the coefficients of the predicted transfer function are shown to be functions of key physical parameters in the plant. Simulations of linear system and model parameter identification is shown to converge to the predicted values of the model coefficients. The multivariable controller developed in this research could be designed in an algebraic fashion once the plant model is known. It is thus possible to implement the multivariable PI design in an adaptive fashion combining the controller with identified plant model on-line. This will result in a self-tuning regulator (STR) type controller where the underlying design criteria is the multivariable tuning technique designed in this research.

10 CFR Appendix D to Part 52 - Design Certification Rule for the AP1000 Design

Code of Federal Regulations, 2011 CFR

2011-01-01

... amendment under 10 CFR 50.90. (1) Maximum fuel rod average burn-up. (2) Fuel principal design requirements... Case-284. (3) Design Summary of Critical Sections. (4) American Concrete Institute (ACI) 318, ACI 349... control system, except burn-up limit. (8) Motor-operated and power-operated valves. (9) Instrumentation...

10 CFR Appendix D to Part 52 - Design Certification Rule for the AP1000 Design

Code of Federal Regulations, 2010 CFR

2010-01-01

... amendment under 10 CFR 50.90. (1) Maximum fuel rod average burn-up. (2) Fuel principal design requirements... Case-284. (3) Design Summary of Critical Sections. (4) American Concrete Institute (ACI) 318, ACI 349... control system, except burn-up limit. (8) Motor-operated and power-operated valves. (9) Instrumentation...

Applications for General Purpose Command Buffers: The Emergency Conjunction Avoidance Maneuver

USGS Publications Warehouse

Scheid, Robert J; England, Martin

2016-01-01

A case study is presented for the use of Relative Operation Sequence (ROS) command buffers to quickly execute a propulsive maneuver to avoid a collision with space debris. In this process, a ROS is custom-built with a burn time and magnitude, uplinked to the spacecraft, and executed in 15 percent of the time of the previous method. This new process provides three primary benefits. First, the planning cycle can be delayed until it is certain a burn must be performed, reducing team workload. Second, changes can be made to the burn parameters almost up to the point of execution while still allowing the normal uplink product review process, reducing the risk of leaving the operational orbit because of outdated burn parameters, and minimizing the chance of accidents from human error, such as missed commands, in a high-stress situation. Third, the science impacts can be customized and minimized around the burn, and in the event of an abort can be eliminated entirely in some circumstances. The result is a compact burn process that can be executed in as few as four hours and can be aborted seconds before execution. Operational, engineering, planning, and flight dynamics perspectives are presented, as well as a functional overview of the code and workflow required to implement the process. Future expansions and capabilities are also discussed.

49 CFR 176.54 - Repairs involving welding, burning, and power-actuated tools and appliances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Repairs involving welding, burning, and power... MATERIALS REGULATIONS CARRIAGE BY VESSEL General Operating Requirements § 176.54 Repairs involving welding..., repairs or work involving welding or burning, or the use of power-actuated tools or appliances which may...

Boiled, tumbled, burned, and heated: Seed scarification techniques for Munro's globemallow appropriate for large-scale application

Treesearch

Olga A. Kildisheva; R. Kasten Dumroese; Anthony S. Davis

2013-01-01

Physically dormant seeds of Munro's globemallow (Sphaeralcea munroana (Douglas) Spach [Malvaceae]) were scarified by boiling, tumbling, burning, dry-heating, and burning + heating treatments in an attempt to find an effective, operational, largescale treatment for nurseries and restoration activities. Results indicate that out of the tested treatments, seed...

49 CFR 176.54 - Repairs involving welding, burning, and power-actuated tools and appliances.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Repairs involving welding, burning, and power... MATERIALS REGULATIONS CARRIAGE BY VESSEL General Operating Requirements § 176.54 Repairs involving welding..., repairs or work involving welding or burning, or the use of power-actuated tools or appliances which may...

49 CFR 176.54 - Repairs involving welding, burning, and power-actuated tools and appliances.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Repairs involving welding, burning, and power... MATERIALS REGULATIONS CARRIAGE BY VESSEL General Operating Requirements § 176.54 Repairs involving welding..., repairs or work involving welding or burning, or the use of power-actuated tools or appliances which may...

49 CFR 176.54 - Repairs involving welding, burning, and power-actuated tools and appliances.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Repairs involving welding, burning, and power... MATERIALS REGULATIONS CARRIAGE BY VESSEL General Operating Requirements § 176.54 Repairs involving welding..., repairs or work involving welding or burning, or the use of power-actuated tools or appliances which may...

49 CFR 176.54 - Repairs involving welding, burning, and power-actuated tools and appliances.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Repairs involving welding, burning, and power... MATERIALS REGULATIONS CARRIAGE BY VESSEL General Operating Requirements § 176.54 Repairs involving welding..., repairs or work involving welding or burning, or the use of power-actuated tools or appliances which may...

Jaggery: an avoidable cause of severe, deadly pediatric burns.

PubMed

Light, T D; Latenser, B A; Heinle, J A; Stolpen, M S; Quinn, K A; Ravindran, V; Chacko, J

2009-05-01

Jaggery is the non-industrial refinement of sugar cane into a sugar product. Sugar cane cultivation, harvest and refinement are central aspects of rural Indian life. We present a retrospective review of pediatric burns at a single institution in Southern India, drawing special attention to scald burns incurred when young children fall into the cauldron of boiling jaggery. Descriptive statistics comparing children burned by jaggery and children burned by other mechanisms were performed. Multivariable logistic regression including burn size and mechanism of burn (jaggery and non-jaggery) was performed to determine the increased risk of death when burned by jaggery. Children burned by jaggery immersions are older, more likely male, and have larger burns. They have longer hospital stays, more operations, and are more likely to die. When controlling for age, gender, size of burn, and mechanism, jaggery exposure was associated with a higher mortality. Jaggery burns are deadly, devastating burns which could be prevented. While jaggery and sugar cane production can lead to economic independence for rural Indian villages, the cost it exacts from burns and death to the youngest and most vulnerable children must be addressed and prevented.

Optical probe for determining the fat/lean interface in cuts of meat

DOEpatents

Weber, Thomas M.; Callow, Diane S.; Jones, James F.; Kuehl, Michael A.; Spletzer, Barry L.

2005-02-22

An apparatus and method for locating the boundary surface between a layer of fatty tissue and lean tissue in a cut of meat, such as beef, such as slabs of meat undergoing trimming and cutting in commercial meet processing facilitates. The invention exploits the fact that fatty tissue and lean tissue have significantly different responses to incident light energy. By gauging the degree to which a generated beam of light is scattered and reflected by the tissues under evaluation, the invention permits the character of the tissue to be ascertained. An incident beam of light, such as green light, is generated and transmitted to a probe tip, which tip is inserted into the cut of meat under investigation. The light beam is emitted into the meat tissues from the probe tip, and then is scattered and reflected by the tissues, whereupon some fraction of the emitted light returns to the probe tip. The returning light energy is transmitted to a detector; relative changes in the returning light transmitted to the detector permit the operator to determine when the probe tip is approaching or penetrating the fat/lean tissue interface.

Trans-10,cis-12 conjugated linoleic acid (t10-c12 CLA) treatment and caloric restriction differentially affect adipocyte cell turnover in obese and lean mice.

PubMed

Yeganeh, Azadeh; Zahradka, Peter; Taylor, Carla G

2017-11-01

Caloric restriction (CR) is one of the most promising strategies for weight loss but is associated with loss of lean mass, whereas compounds such as trans-10,cis-12 conjugated linoleic acid (t10-c12 CLA) have been promoted as antiobesity agents. To compare the mechanisms of weight reduction by CR and t10-c12 CLA, body composition, glucose control, and characteristics of adipose tissue with respect to cell turnover (stem cells and preadipocytes, apoptosis and autophagy) and Tbx-1 localization were examined in obese db/db mice and lean C57BL/6J mice undergoing CR or fed CLA isomers (0.4% w/w c9-t11 or t10-c12) for 4 weeks. Our findings show that the t10-c12 CLA reduced whole-body fat mass by decreasing all fat depots (visceral, inguinal, brown/interscapular), while CR lowered both whole-body fat and lean mass in obese mice. t10-c12 CLA elevated blood glucose in both obese and lean mice, while glycemia was not altered by CR. The adipocyte stem cell population remained unchanged; however, t10-c12 CLA reduced and CR elevated the proportion of immature adipocytes in obese mice, suggesting differential effects on adipocyte maturation. t10-c12 CLA reduced apoptosis (activated caspase-3) in both obese and lean mice but did not alter autophagy (LC3II/LC3I). Nuclear Tbx-1, a marker of metabolically active beige adipocytes, was greater in the adipose of t10-c12 CLA-fed animals. Thus, weight loss achieved via t10-c12 CLA primarily involves fat loss and more cells with Tbx-1 localized to the nucleus, while CR operates through a mechanism that reduces both lean and fat mass and blocks adipocyte differentiation. Copyright © 2017 Elsevier Inc. All rights reserved.

An analysis of surgical and anaesthetic factors affecting skin graft viability in patients admitted to a Burns Intensive Care Unit.

PubMed

Isitt, Catherine E; McCloskey, Kayleigh A; Caballo, Alvaro; Sharma, Pranev; Williams, Andrew; Leon-Villapalos, Jorge; Vizcaychipi, Marcela P

2016-01-01

Skin graft failure is a recognised complication in the treatment of major burns. Little research to date has analysed the impact of the complex physiological management of burns patients on the success of skin grafting. We analysed surgical and anaesthetic variables to identify factors contributing to graft failure. Inclusion criteria were admission to our Burns Intensive Care Unit (BICU) between January 2009 and October 2013 with a major burn. After exclusion for death before hospital discharge or prior skin graft at a different hospital, 35 patients remained and were divided into those with successful autografts (n=16) and those with a failed autograft (n=19). For the purposes of this study, we defined poor autograft viability as requiring at least one additional skin graft to the same site. Logistic regression of variables was performed using SPSS (Version 22.0 IBMTM). Age, Sex, %Total Burn Surface Area or Belgian Outcome Burns Injury score did not significantly differ between groups. No differences were found in any surgical factor at logistic regression (graft site, harvest site, infection etc.). When all operations were analysed, the use of colloids was found to be significantly associated with graft failure (p=0.035, CI 95%) and this remained significant when only split thickness skin grafts (STSGs) and debridement operations were included (p=0.034, CI 95%). No differences were found in crystalloid use, intraoperative temperature, pre-operative haemoglobin and blood products or vasopressor use. This analysis highlights an independent association between colloids and graft failure which has not been previously documented.

Surgical Fires and Operative Burns: Lessons Learned From a 33-Year Review of Medical Litigation.

PubMed

Choudhry, Asad J; Haddad, Nadeem N; Khasawneh, Mohammad A; Cullinane, Daniel C; Zielinski, Martin D

2017-03-01

We aimed to understand the setting and litigation outcomes of surgical fires and operative burns. Westlaw, an online legal research data-set, was utilized. Data were collected on patient, procedure, and case characteristics. One hundred thirty-nine cases were identified; 114 (82%) operative burns and 25 (18%) surgical fires. Median plaintiff (patient) age was 46 (IQR:28-59). Most common site of operative burn was the face (26% [n = 36]). Most common source of injury was a high energy device (43% [n = 52]). Death was reported in 2 (1.4%) cases. Plaintiff age <18 vs age 18-50 and mention of a non-surgical physician as a defendant both were shown to be independently associated with an award payout (OR = 4.90 [95% CI, 1.23-25.45]; p = .02) and (OR = 4.50 [95% CI, 1.63-13.63]; p = .003) respectively. Plaintiff award payment (settlement or plaintiff verdict) was reported in 83 (60%) cases; median award payout was $215,000 (IQR: $82,000-$518,000). High energy devices remain as the most common cause of injury. Understanding and addressing pitfalls in operative care may mitigate errors and potentially lessen future liability. III. Copyright © 2016 Elsevier Inc. All rights reserved.

Operating Room Time Savings with the Use of Splint Packs: A Randomized Controlled Trial

PubMed Central

Gonzalez, Tyler A.; Bluman, Eric M.; Palms, David; Smith, Jeremy T.; Chiodo, Christopher P.

2016-01-01

Background: The most expensive variable in the operating room (OR) is time. Lean Process Management is being used in the medical field to improve efficiency in the OR. Streamlining individual processes within the OR is crucial to a comprehensive time saving and cost-cutting health care strategy. At our institution, one hour of OR time costs approximately $500, exclusive of supply and personnel costs. Commercially prepared splint packs (SP) contain all components necessary for plaster-of-Paris short-leg splint application and have the potential to decrease splint application time and overall costs by making it a more lean process. We conducted a randomized controlled trial comparing OR time savings between SP use and bulk supply (BS) splint application. Methods: Fifty consecutive adult operative patients on whom post-operative short-leg splint immobilization was indicated were randomized to either a control group using BS or an experimental group using SP. One orthopaedic surgeon (EMB) prepared and applied all of the splints in a standardized fashion. Retrieval time, preparation time, splint application time, and total splinting time for both groups were measured and statistically analyzed. Results: The retrieval time, preparation time and total splinting time were significantly less (p<0.001) in the SP group compared with the BS group. There was no significant difference in application time between the SP group and BS group. Conclusion: The use of SP made the process of splinting more lean. This has resulted in an average of 2 minutes 52 seconds saved in total splinting time compared to BS, making it an effective cost-cutting and time saving technique. For high volume ORs, use of splint packs may contribute to substantial time and cost savings without impacting patient safety. PMID:26894212

Lean management in health care: definition, concepts, methodology and effects reported (systematic review protocol).

PubMed

Lawal, Adegboyega K; Rotter, Thomas; Kinsman, Leigh; Sari, Nazmi; Harrison, Liz; Jeffery, Cathy; Kutz, Mareike; Khan, Mohammad F; Flynn, Rachel

2014-09-19

Lean is a set of operating philosophies and methods that help create a maximum value for patients by reducing waste and waits. It emphasizes the consideration of the customer's needs, employee involvement and continuous improvement. Research on the application and implementation of lean principles in health care has been limited. This is a protocol for a systematic review, following the Cochrane Effective Practice and Organisation of Care (EPOC) methodology. The review aims to document, catalogue and synthesize the existing literature on the effects of lean implementation in health care settings especially the potential effects on professional practice and health care outcomes. We have developed a Medline keyword search strategy, and this focused strategy will be translated into other databases. All search strategies will be provided in the review. The method proposed by the Cochrane EPOC group regarding randomized study designs, non-randomised controlled trials controlled before and after studies and interrupted time series will be followed. In addition, we will also include cohort, case-control studies, and relevant non-comparative publications such as case reports. We will categorize and analyse the review findings according to the study design employed, the study quality (low- versus high-quality studies) and the reported types of implementation in the primary studies. We will present the results of studies in a tabular form. Overall, the systematic review aims to identify, assess and synthesize the evidence to underpin the implementation of lean activities in health care settings as defined in this protocol. As a result, the review will provide an evidence base for the effectiveness of lean and implementation methodologies reported in health care. PROSPERO CRD42014008853.

Lean management in health care: definition, concepts, methodology and effects reported (systematic review protocol)

PubMed Central

2014-01-01

Background Lean is a set of operating philosophies and methods that help create a maximum value for patients by reducing waste and waits. It emphasizes the consideration of the customer’s needs, employee involvement and continuous improvement. Research on the application and implementation of lean principles in health care has been limited. Methods This is a protocol for a systematic review, following the Cochrane Effective Practice and Organisation of Care (EPOC) methodology. The review aims to document, catalogue and synthesize the existing literature on the effects of lean implementation in health care settings especially the potential effects on professional practice and health care outcomes. We have developed a Medline keyword search strategy, and this focused strategy will be translated into other databases. All search strategies will be provided in the review. The method proposed by the Cochrane EPOC group regarding randomized study designs, non-randomised controlled trials controlled before and after studies and interrupted time series will be followed. In addition, we will also include cohort, case–control studies, and relevant non-comparative publications such as case reports. We will categorize and analyse the review findings according to the study design employed, the study quality (low- versus high-quality studies) and the reported types of implementation in the primary studies. We will present the results of studies in a tabular form. Discussion Overall, the systematic review aims to identify, assess and synthesize the evidence to underpin the implementation of lean activities in health care settings as defined in this protocol. As a result, the review will provide an evidence base for the effectiveness of lean and implementation methodologies reported in health care. Systematic review registration PROSPERO CRD42014008853 PMID:25238974

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as defined by...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as defined by...

Risk factors for the development of heterotopic ossification in seriously burned adults: A National Institute on Disability, Independent Living and Rehabilitation Research burn model system database analysis.

PubMed

Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B; Ring, David C; Kowalske, Karen; Gibran, Nicole S; Herndon, David; Schneider, Jeffrey C; Ryan, Colleen M

2015-11-01

Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study, we use a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Data from six high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. When controlling for age and sex in a multivariate model, patients with greater than 30% total body surface area burn had 11.5 times higher odds of developing HO (p < 0.001), and those with arm burns that required skin grafting had 96.4 times higher odds of developing HO (p = 0.04). For each additional time a patient went to the operating room, odds of HO increased by 30% (odds ratio, 1.32; p < 0.001), and each additional ventilator day increased odds by 3.5% (odds ratio, 1.035; p < 0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Risk factors for HO development include greater than 30% total body surface area burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. Prognostic study, level III.

Risk Factors for the Development of Heterotopic Ossification in Seriously Burned Adults: A NIDRR Burn Model System Database Analysis

PubMed Central

Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B.; Ring, David C.; Kowalske, Karen; Gibran, Nicole S.; Herndon, David; Schneider, Jeffrey C.; Ryan, Colleen M.

2015-01-01

Purpose Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study we utilize a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Methods Data from 6 high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Results Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. Controlling for age and sex in a multivariate model, patients with >30% total body surface area (TBSA) burn had 11.5x higher odds of developing HO (p<0.001), and those with arm burns that required skin grafting had 96.4x higher odds of developing HO (p=0.04). For each additional time a patient went to the operating room, odds of HO increased 30% (OR 1.32, p<0.001), and each additional ventilator day increase odds 3.5% (OR 1.035, p<0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Conclusion Risk factors for HO development include >30% TBSA burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. PMID:26496115

76 FR 5610 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Network Centric...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

... Production Act of 1993--Network Centric Operations Industry Consortium, Inc. Notice is hereby given that, on..., 15 U.S.C. 4301 et seq. (``the Act''), Network Centric Operations Industry Consortium, Inc. (``NCOIC...&D Institute, Gdynia, POLAND; Solera Networks, Lindon, UT; and Dataline, LLC, McLean, VA, have...

A Laser Spark Plug Ignition System for a Stationary Lean-Burn Natural Gas Reciprocating Engine

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

McIntyre, D. L.

To meet the ignition system needs of large bore, high pressure, lean burn, natural gas engines a side pumped, passively Q-switched, Nd:YAG laser was developed and tested. The laser was designed to produce the optical intensities needed to initiate ignition in a lean burn, high compression engine. The laser and associated optics were designed with a passive Q-switch to eliminate the need for high voltage signaling and associated equipment. The laser was diode pumped to eliminate the need for high voltage flash lamps which have poor pumping efficiency. The independent and dependent parameters of the laser were identified and exploredmore » in specific combinations that produced consistent robust sparks in laboratory air. Prior research has shown that increasing gas pressure lowers the breakdown threshold for laser initiated ignition. The laser has an overall geometry of 57x57x152 mm with an output beam diameter of approximately 3 mm. The experimentation used a wide range of optical and electrical input parameters that when combined produced ignition in laboratory air. The results show a strong dependence of the output parameters on the output coupler reflectivity, Q-switch initial transmission, and gain media dopant concentration. As these three parameters were lowered the output performance of the laser increased leading to larger more brilliant sparks. The results show peak power levels of up to 3MW and peak focal intensities of up to 560 GW/cm 2. Engine testing was performed on a Ricardo Proteus single cylinder research engine. The goal of the engine testing was to show that the test laser performs identically to the commercially available flashlamp pumped actively Q-switched laser used in previous laser ignition testing. The engine testing consisted of a comparison of the in-cylinder, and emissions behavior of the engine using each of the lasers as an ignition system. All engine parameters were kept as constant as possilbe while the equivalence ratio (fueling), and hence the engine load, was varied between 0.8, 0.9, and 1.0. The test laser was constructed with a 30% output coupler, 32% Q-switch initial transmission, and a 0.5% Nd concentration rod all pumped by approximately 1000 Watts of optical power. The test laser single mode output pulse had an energy of approximately 23 mJ, with a pulsewidth of approximately 10 ns, and an M2 value of 6.55. This output produced focal intensity of approximately 270 GW/cm 2 with the modified on-engine optical arrangement. The commercial laser had similar output parameters and both laser systems operated the engine with similar results. Due to the shortening of the focal length of the on-engine optical setup both laser systems produced a spark well within the optical transfer cavity of the laser optics to spark plug adaptor. This shrouded spark led to a very long ignition delay and retarded combustion timing for all three values of equivalence ratio. This was evidenced by the in-cylinder pressure traces and the HRR waveforms. The emissions data indicate that both lasers produced very similar combustion. The ignition delay caused by the shrouded spark cause most of the combustion to happen after TDC which lead to poor combustion that produced high levels of CO and THC. The novelty of this work lies in the combination of the laser parameters to create a single high peak power laser output pulse for use as a spark ignition source. Similar configurations have been investigated in the literature but for different applications such as multiple output pulse trains for various industrial and communications applications. Another point of novelty is the investigation of the laser medium concentration on the output characteristics of a passively Q-switched laser system. This work has shown that lowering the Neodymium concentration in the active media within a passively Q-switched laser produces higher output energy values. This is significant because an actively Q-switched laser shows the opposite affect when the active ion concentration is varied.« less

Nursing research on a first aid model of double personnel for major burn patients.

PubMed

Wu, Weiwei; Shi, Kai; Jin, Zhenghua; Liu, Shuang; Cai, Duo; Zhao, Jingchun; Chi, Cheng; Yu, Jiaao

2015-03-01

This study explored the effect of a first aid model employing two nurses on the efficient rescue operation time and the efficient resuscitation time for major burn patients. A two-nurse model of first aid was designed for major burn patients. The model includes a division of labor between the first aid nurses and the re-organization of emergency carts. The clinical effectiveness of the process was examined in a retrospective chart review of 156 cases of major burn patients, experiencing shock and low blood volume, who were admitted to the intensive care unit of the department of burn surgery between November 2009 and June 2013. Of the 156 major burn cases, 87 patients who received first aid using the double personnel model were assigned to the test group and the 69 patients who received first aid using the standard first aid model were assigned to the control group. The efficient rescue operation time and the efficient resuscitation time for the patients were compared between the two groups. Student's t tests were used to the compare the mean difference between the groups. Statistically significant differences between the two groups were found on both measures (P's < 0.05), with the test group having lower times than the control group. The efficient rescue operation time was 14.90 ± 3.31 min in the test group and 30.42 ± 5.65 min in the control group. The efficient resuscitation time was 7.4 ± 3.2 h in the test group and 9.5 ± 2.7 h in the control group. A two-nurse first aid model based on scientifically validated procedures and a reasonable division of labor can shorten the efficient rescue operation time and the efficient resuscitation time for major burn patients. Given these findings, the model appears to be worthy of clinical application.

Acute and Perioperative Care of the Burn-Injured Patient

PubMed Central

Bittner, Edward A.; Shank, Erik; Woodson, Lee; Martyn, J.A. Jeevendra

2016-01-01

Care of burn-injured patients requires knowledge of the pathophysiologic changes affecting virtually all organs from the onset of injury until wounds are healed. Massive airway and/or lung edema can occur rapidly and unpredictably after burn and/or inhalation injury. Hemodynamics in the early phase of severe burn injury are characterized by a reduction in cardiac output, increased systemic and pulmonary vascular resistance. Approximately 2–5 days after major burn injury, a hyperdynamic and hypermetabolic state develops. Electrical burns result in morbidity much higher than expected based on burn size alone. Formulae for fluid resuscitation should serve only as guideline; fluids should be titrated to physiologic end points. Burn injury is associated basal and procedural pain requiring higher than normal opioid and sedative doses. Operating room concerns for the burn-injured patient include airway abnormalities, impaired lung function, vascular access, deceptively large and rapid blood loss, hypothermia and altered pharmacology. PMID:25485468

Under-burning and dwarf mistletoe: Scorch 'n' toe

Treesearch

David A. Conklin; Brian W. Geils

2008-01-01

Relatively little quantitative information has been available on the effects of low-intensity fire (under-burning) on dwarf mistletoe. Here we summarize results from six operational prescribed under-burns in second-growth ponderosa pine in New Mexico (Conklin and Geils, in press). For 1585 trees on 14 plots, crown scorch, bole char, and DMR were significant predictors...

Comparison Between Civilian Burns and Combat Burns From Operation Iraqi Freedom and Operation Enduring Freedom

PubMed Central

Wolf, Steven E.; Kauvar, David S.; Wade, Charles E.; Cancio, Leopoldo C.; Renz, Evan P.; Horvath, Edward E.; White, Christopher E.; Park, Myung S.; Wanek, Sandra; Albrecht, Michael A.; Blackbourne, Lorne H.; Barillo, David J.; Holcomb, John B.

2006-01-01

Objective: To assess outcome differences between locally burned civilians and military personnel burned in a distant combat zone treated in the same facility. Summary Background Data: The United States Army Institute of Surgical Research (USAISR) Burn Center serves as a referral center for civilians and is the sole center for significant burns in military personnel. We made the hypothesis that outcomes for military personnel burned in the current conflict in Iraq and Afghanistan would be poorer because of delays to definitive treatment, other associated injury, and distance of evacuation. Methods: We reviewed the civilian and military records of patients treated at the USAISR from the outset of hostilities in Iraq in April 2003 to May 2005. Demographics, injury data, mortality, and clinical outcomes were compared. Results: We cared for 751 patients during this time period, 273 of whom were military (36%). Military injuries occurred in a younger population (41 ± 19 vs. 26 ± 7 years for civilian and military respectively, P < 0.0001) with a longer time from injury to burn center arrival (1 ± 5 days vs. 6 ± 5, P < 0.0001), a higher Injury Severity Score (ISS 5 ± 8 vs. 9 ± 11, P < 0.0001), and a higher incidence of inhalation injury (8% vs. 13%, P = 0.024). Total burn size did not differ. Mortality was 7.1% in the civilian and 3.8% in the military group (P = 0.076). When civilians outside the age range of the military cohort were excluded, civilian mortality was 5.0%, which did not differ from the military group (P = 0.57). Total body surface area (TBSA) burned, age ≥40 years, presence of inhalation injury, and ventilator days were found to be important predictors of mortality by stepwise regression, and were used in a final predictive model with the area under receiver operator characteristic curve of 0.97 for both populations considered together. No significant effect of either group was identified during development. Conclusions: Mortality does not differ between civilians evacuated locally and military personnel injured in distant austere environments treated at the same center. PMID:16772782

Comparison between civilian burns and combat burns from Operation Iraqi Freedom and Operation Enduring Freedom.

PubMed

Wolf, Steven E; Kauvar, David S; Wade, Charles E; Cancio, Leopoldo C; Renz, Evan P; Horvath, Edward E; White, Christopher E; Park, Myung S; Wanek, Sandra; Albrecht, Michael A; Blackbourne, Lorne H; Barillo, David J; Holcomb, John B

2006-06-01

To assess outcome differences between locally burned civilians and military personnel burned in a distant combat zone treated in the same facility. The United States Army Institute of Surgical Research (USAISR) Burn Center serves as a referral center for civilians and is the sole center for significant burns in military personnel. We made the hypothesis that outcomes for military personnel burned in the current conflict in Iraq and Afghanistan would be poorer because of delays to definitive treatment, other associated injury, and distance of evacuation. We reviewed the civilian and military records of patients treated at the USAISR from the outset of hostilities in Iraq in April 2003 to May 2005. Demographics, injury data, mortality, and clinical outcomes were compared. : We cared for 751 patients during this time period, 273 of whom were military (36%). Military injuries occurred in a younger population (41 +/- 19 vs. 26 +/- 7 years for civilian and military respectively, P < 0.0001) with a longer time from injury to burn center arrival (1 +/- 5 days vs. 6 +/- 5, P < 0.0001), a higher Injury Severity Score (ISS 5 +/- 8 vs. 9 +/- 11, P < 0.0001), and a higher incidence of inhalation injury (8% vs. 13%, P = 0.024). Total burn size did not differ. Mortality was 7.1% in the civilian and 3.8% in the military group (P = 0.076). When civilians outside the age range of the military cohort were excluded, civilian mortality was 5.0%, which did not differ from the military group (P = 0.57). Total body surface area (TBSA) burned, age > or =40 years, presence of inhalation injury, and ventilator days were found to be important predictors of mortality by stepwise regression, and were used in a final predictive model with the area under receiver operator characteristic curve of 0.97 for both populations considered together. No significant effect of either group was identified during development. Mortality does not differ between civilians evacuated locally and military personnel injured in distant austere environments treated at the same center.

Lean and Green Hand Surgery.

PubMed

Van Demark, Robert E; Smith, Vanessa J S; Fiegen, Anthony

2018-02-01

Health care in the United States is both expensive and wasteful. The cost of health care in the United States continues to increase every year. Health care spending for 2016 is estimated at $3.35 trillion. Per capita spending ($10,345 per person) is more than twice the average of other developed countries. The United States also leads the world in solid waste production (624,700 metric tons of waste in 2011). The health care industry is second only to the food industry in annual waste production. Each year, health care facilities in the United States produce 4 billion pounds of waste (660 tons per day), with as much as 70%, or around 2.8 billion pounds, produced directly by operating rooms. Waste disposal also accounts for up to 20% of a hospital's annual environmental services budget. Since 1992, waste production by hospitals has increased annually by a rate of at least 15%, due in part to the increased usage of disposables. Reduction in operating room waste would decrease both health care costs and potential environmental hazards. In 2015, the American Association for Hand Surgery along with the American Society for Surgery of the Hand, American Society for Peripheral Nerve Surgery, and the American Society of Reconstructive Microsurgery began the "Lean and Green" surgery project to reduce the amount of waste generated by hand surgery. We recently began our own "Lean and Green" project in our institution. Using "minor field sterility" surgical principles and Wide Awake Local Anesthesia No Tourniquet (WALANT), both surgical costs and surgical waste were decreased while maintaining patient safety and satisfaction. As the current reimbursement model changes from quantity to quality, "Lean and Green" surgery will play a role in the future health care system. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Lean principles optimize on-time vascular surgery operating room starts and decrease resident work hours.

PubMed

Warner, Courtney J; Walsh, Daniel B; Horvath, Alexander J; Walsh, Teri R; Herrick, Daniel P; Prentiss, Steven J; Powell, Richard J

2013-11-01

Lean process improvement techniques are used in industry to improve efficiency and quality while controlling costs. These techniques are less commonly applied in health care. This study assessed the effectiveness of Lean principles on first case on-time operating room starts and quantified effects on resident work hours. Standard process improvement techniques (DMAIC methodology: define, measure, analyze, improve, control) were used to identify causes of delayed vascular surgery first case starts. Value stream maps and process flow diagrams were created. Process data were analyzed with Pareto and control charts. High-yield changes were identified and simulated in computer and live settings prior to implementation. The primary outcome measure was the proportion of on-time first case starts; secondary outcomes included hospital costs, resident rounding time, and work hours. Data were compared with existing benchmarks. Prior to implementation, 39% of first cases started on time. Process mapping identified late resident arrival in preoperative holding as a cause of delayed first case starts. Resident rounding process inefficiencies were identified and changed through the use of checklists, standardization, and elimination of nonvalue-added activity. Following implementation of process improvements, first case on-time starts improved to 71% at 6 weeks (P = .002). Improvement was sustained with an 86% on-time rate at 1 year (P < .001). Resident rounding time was reduced by 33% (from 70 to 47 minutes). At 9 weeks following implementation, these changes generated an opportunity cost potential of $12,582. Use of Lean principles allowed rapid identification and implementation of perioperative process changes that improved efficiency and resulted in significant cost savings. This improvement was sustained at 1 year. Downstream effects included improved resident efficiency with decreased work hours. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Decreasing the Preincision Time for Pulmonary Lobectomy: The Process of Lean and Value Stream Mapping.

PubMed

Cerfolio, Robert James; Steenwyk, Brad L; Watson, Caroline; Sparrow, James; Belopolsky, Victoria; Townsley, Matthew; Lyerly, Ralph; Downing, Michelle; Bryant, Ayesha; Gurley, William Quinton; Henling, Colleen; Crawford, Jack; Gayeski, Thomas E

2016-03-01

Our objective was to evaluate our results after the implementation of lean (the elimination of wasteful parts of a process). After meetings with our anesthesiologists, we standardized our "in the operating room-to-skin incision protocols" before pulmonary lobectomy. Patients were divided into consecutive cohorts of 300 lobectomy patients. Several protocols were slowly adopted and outcomes were evaluated. One surgeon performed 2,206 pulmonary lobectomies, of which 84% were for cancer. Protocols for lateral decubitus positioning changed over time. We eliminated axillary rolls, arm boards, and beanbags. Monitoring devices were slowly eliminated. Central catheters decreased from 75% to 0% of patients, epidurals from 84% to 3%, arterial catheters from 93% to 4%, and finally, Foley catheters were reduced from 99% to 11% (p ≤ 0.001 for all). A protocol for the insertion of double-lumen endotracheal tubes was established and times decreased (mean, 14 minutes to 1 minute; p = 0.001). After all changes were made, the time between operating room entry and incision decreased from a mean of 64 minutes to 37 minutes (p < 0.001). Outcomes improved, mortality decreased from 3.2% to 0.26% (p = 0.015), and major morbidity decreased from 15.2% to 5.3% (p = 0.042). Lean and value stream mapping can be safely applied to the clinical algorithms of high-risk patient care. We demonstrate that elimination of non-value-added steps can safely decrease preincision time without increasing patient risk in patients who undergo pulmonary lobectomy. Selected centers may be able to adopt some of these lean-driven protocols. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Integrating Lean Exploration Loops Into Healthcare Facility Design.

PubMed

Johnson, Kendra; M Mazur, Lukasz; Chadwick, Janet; Pooya, Pegah; Amos, Alison; McCreery, John

2017-04-01

To explore how Lean can add value during the schematic phase of design through providing additional resources and support to project leadership and the architectural design team. This case study-based research took place at one large academic hospital during design efforts of surgical tower to house 19 operating rooms (ORs) and support spaces including pre- and post-op, central processing and distribution, and materials management. Surgical services project leadership asked for Lean practitioners' support during the design process. Lean Exploration Loops (LELs) were conducted to generate evidence to support stakeholders, as they made important decisions about the new building design. The analyses conducted during LELs during the schematic phase were primarily conducted using express workouts (EWOs) and were focused on the flow of patients, staff, and family throughout the pavilion. LELs resulted in recommendations for key design features (e.g., number of pre- and post-op bays per OR floor, location of doors, scrub sinks, stretcher alcoves, equipment storage, and sterile core areas). Two-sided pre- and post-op bays with an inner clinical workspace and an outer patient transport corridor were recommended. Communicating elevator and a centrally located stairwell for staff to alleviate stress on the main bank of elevators at peak usage times were also suggested. We found Lean tools and methods to be of most value during schematic phase when focused on detailed process and layout analysis, while acknowledging the usefulness of focused EWOs to generate the evidence needed for the decision-making.

[Etiological analysis of subambient temperature burn in 351 cases of Hefei area].

PubMed

Shi, Jie; Qi, Weiwei; Xu, Qinglian; Zhou, Shunying; Wang, Guobao

2010-06-01

To study the preventive measure of the subambient temperature burn by analysing the pathogenesis feature. The clinical data were analysed from 351 cases of subambient temperature burn between February 2004 and February 2009, including age, sex, burn season, burn factors, burn position, burn area, burn degree, treatment way, and wound healing. Subambient temperature burn occurred in every age stage. The susceptible age stages included infant, children, and the elderly. Female patients were more than male patients. The common burn reasons were hot-water bottle burn, honey warm keeper burn, and heating device burn. The peak season was winter. Lower limb was the most common site of the subambient temperature burn. The deep II degree to III degree were the most common level, and the burn area was always small, often < or = 1% of total body surface area. Most of patients were treated with changing dressings at clinic and few patients needed hospitalization. Though the surface of wound could heal finally, and the wound healed well with no obvious scar in patients who received operation. Subambient temperature burn is the frequently encountered disease in winter. Use of the warming articles should be cautious, at the same time safety awareness should be strengthened so as to decrease the incidence rate of subambient temperature burn and the injury degree.