Implanted component faults and their effects on gas turbine engine performance

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

MacLeod, J.D.; Taylor, V.; Laflamme, J.C.G.

Under the sponsorship of the Canadian Department of National Defence, the Engine Laboratory of the National Research Council of Canada (NRCC) has established a program for the evaluation of component deterioration on gas turbine engine performance. The effect is aimed at investigating the effects of typical in-service faults on the performance characteristics of each individual engine component. The objective of the program is the development of a generalized fault library, which will be used with fault identification techniques in the field, to reduce unscheduled maintenance. To evaluate the effects of implanted faults on the performance of a single spool engine,more » such as an Allison T56 turboprop engine, a series of faulted parts were installed. For this paper the following faults were analyzed: (a) first-stage turbine nozzle erosion damage; (b) first-stage turbine rotor blade untwist; (c) compressor seal wear; (d) first and second-stage compressor blade tip clearance increase. This paper describes the project objectives, the experimental installation, and the results of the fault implantation on engine performance. Discussed are performance variations on both engine and component characteristics. As the performance changes were significant, a rigorous measurement uncertainty analysis is included.« less

Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 deg to 90 deg. 1: Influence of airplane components for model D. [Langley spin tunnel tests

NASA Technical Reports Server (NTRS)

Ralston, J.

1983-01-01

The influence of airplane components, as well as wing location and tail length, on the rotational flow aerodynamics is discussed for a 1/6 scale general aviation airplane model. The airplane was tested in a built-up fashion (i.e., body, body-wing, body-wing-vertical, etc.) in the presence of two wing locations and two body lengths. Data were measured, using a rotary balance, over an angle-of-attack range of 8 deg to 90 deg, and for clockwise and counter-clockwise rotations covering an omega b/2V range of 0 to 0.9.

CF6 Jet Engine Performance Improvement Program: High Pressure Turbine Aerodynamic Performance Improvement

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1980-01-01

The improved single shank high pressure turbine design was evaluated in component tests consisting of performance, heat transfer and mechanical tests, and in core engine tests. The instrumented core engine test verified the thermal, mechanical, and aeromechanical characteristics of the improved turbine design. An endurance test subjected the improved single shank turbine to 1000 simulated flight cycles, the equivalent of approximately 3000 hours of typical airline service. Initial back-to-back engine tests demonstrated an improvement in cruise sfc of 1.3% and a reduction in exhaust gas temperature of 10 C. An additional improvement of 0.3% in cruise sfc and 6 C in EGT is projected for long service engines.

Introducing High School Students and Science Teachers to Chemical Engineering.

ERIC Educational Resources Information Center

Bayles, Taryn Melkus; Aguirre, Fernando J.

1992-01-01

Describes a summer institute for science teachers and their students in which the main goal was to increase enrollment in engineering and to encourage women and minority groups to increase their representation in the engineering workforce. Includes a description of typical chemical engineering jobs and general instruction in material balances,…

Prechamber Compression-Ignition Engine Performance

NASA Technical Reports Server (NTRS)

Moore, Charles S; Collins, John H , Jr

1938-01-01

Single-cylinder compression-ignition engine tests were made to investigate the performance characteristics of prechamber type of cylinder head. Certain fundamental variables influencing engine performance -- clearance distribution, size, shape, and direction of the passage connecting the cylinder and prechamber, shape of prechamber, cylinder clearance, compression ratio, and boosting -- were independently tested. Results of motoring and of power tests, including several typical indicator cards, are presented.

Virginia Space Grant Consortium Management of National General Aviation Design Competition

NASA Technical Reports Server (NTRS)

2002-01-01

This report summarizes the management of the National General Aviation Design Competition on behalf of NASA, the FAA and the Air Force by the Virginia Space Grant Consortium (VSGC) for the time period October 1, 2000 through September 30, 2001. This was the VSGC's seventh and final year of managing the Competition, which the Consortium originally designed, developed and implemented for NASA and the FAA. The competition is now being managed in-house by NASA. Awards to winning university teams were presented at a ceremony held at AirVenture 2001, the Experimental Aircraft Association's Annual Convention and Fly-In at Oshkosh, Wis. by NASA and FAA officials. The competition called for individuals or teams of undergraduate and graduate students from U.S. engineering schools to participate in a major national effort to rebuild the U.S. general aviation sector. Participants were challenged to meet the engineering goals of the Advanced General Aviation Transport Experiment (AGATE) project. For the purpose of the contest, general aviation aircraft are typically defined as single or twin engine (turbine or piston), single-pilot, fixed-wing aircraft for 2 - 6 passengers. The competition seeks to raise student awareness of the importance of general aviation by having students address design challenges for a small aircraft transportation system. NASA, AFRL and the FAA hope to stimulate breakthroughs in technology and their application in the general aviation marketplace. National goals for revitalizing the industry offer excellent, open-ended design challenges with real world applications for the Innovative Design Category. Both individual and team submissions were encouraged. University faculty advisors and students consistently cite the value of this kind of educational experience for their engineering students. Eight proposals were submitted for the 2001 Competition for the Innovative Design Category. Eleven faculty members and 124 students participated. Since inception, more than 785 students and 60 faculty members have participated in the Competition. A review panel comprised of general aviation experts from the FAA, EAA, NASA and industry representatives reviewed the design packages and selected the winners. The VSGC coordinated marketing of the competition to a mailing list which included selected deans and department chairs from ABET-accredited institutions, Space Grant affiliates, faculty who had previously participated in or expressed interest in the Competition, and others.

Cockpit noise intensity : eleven twin-engine light aircraft.

DOT National Transportation Integrated Search

1968-10-01

Eleven of the most popular twin-engine general-aviation light aircraft were tested for the noise intensity present during normal cruising operations at 2000, 6000, and 10000 feet MSL (mean sea level). Although generally quieter than single-engine pla...

Measurement of Work Generation and Improvement in Performance of a Pulse Tube Engine

NASA Astrophysics Data System (ADS)

Hamaguchi, Kazuhiro; Futagi, Hiroaki; Yazaki, Taichi; Hiratsuka, Yoshikatsu

Apart from double acting type engines, Stirling engines have either 2 pistons in 2 cylinders or 2 pistons in a single cylinder. Typically, the heater, regenerator and cooler are installed between the 2 pistons. The pulse tube engine, on the other hand, consists of a single piston in a single cylinder, a pulse tube, a heater, a regenerator, a cooler and a second cooler. For this paper, a simple prototype engine that uses air at normal atmospheric pressure as the working gas was fabricated. The oscillating velocity of the working gas in the pulse tube was measured using LDV, and the work flow emitting out of the pulse tube was observed. In addition, the effect of inserting heat storage material in the pulse tube on shaft power and indicated power was examined experimentally. A dramatic increase in the shaft power was achieved.

Civil Engineering Technology Program Guide.

ERIC Educational Resources Information Center

Georgia Univ., Athens. Dept. of Vocational Education.

This program guide presents civil engineering technology curriculum for technical institutes in Georgia. The general information section contains the following: purpose and objectives; program description, including admissions, typical job titles, and accreditation and certification; and curriculum model, including standard curriculum sequence and…

Performance improvements of single-engine business airplanes by the integration of advanced technologies

NASA Technical Reports Server (NTRS)

Kohlman, D. L.

1982-01-01

An assessment is presented of the performance gains and economic impact of the integration in general aviation aircraft of advanced technologies, relating to such aspects of design as propulsion, natural laminar flow, lift augmentation, unconventional configurations, and advanced aluminum and composite structures. All considerations are with reference to a baseline mission of 1300 nm range and 300-knot cruise speed with a 1300-lb payload, and a baseline aircraft with a 40 lb/sq ft wing loading and an aspect ratio of 8. Extensive analytical results are presented from the NASA-sponsored General Aviation Synthesis Program. Attention is given to the relative performance gains to be expected from the single-engined baseline aircraft's use of a low cost general aviation turbine engine, a spark-ignited reciprocating engine, a diesel engine, and a Wankel rotary engine.

Speed limits set lower than engineering recommendations : project summary report.

DOT National Transportation Integrated Search

2016-08-01

The Montana Department of Transportation (MDT) generally ensures that posted speed limits are set in accordance with engineering recommendations, which means that speed limits are typically set such that they are about equal to the observed 85th-perc...

SECONDARY GENERAL MOTORS DIESEL ENGINE WITH CONNECTION TO REDUCTION GEAR ...

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

SECONDARY GENERAL MOTORS DIESEL ENGINE WITH CONNECTION TO REDUCTION GEAR BELT DRIVE SYSTEM, LOOKING SOUTH. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

Cockpit noise intensity : fifteen single-engine light aircraft.

DOT National Transportation Integrated Search

1968-09-01

Fifteen of the most popular single-engine general-aviation light aircraft were tested for the noise intensity present during normal cruising operations at 2000, and 10,000 feet MSL (mean sea level). In comparison with currently accepted DRC (damage-r...

Engine-induced structural-borne noise in a general aviation aircraft

NASA Technical Reports Server (NTRS)

Unruh, J. F.; Scheidt, D. C.; Pomerening, D. J.

1979-01-01

Structural borne interior noise in a single engine general aviation aircraft was studied to determine the importance of engine induced structural borne noise and to determine the necessary modeling requirements for the prediction of structural borne interior noise. Engine attached/detached ground test data show that engine induced structural borne noise is a primary interior noise source for the single engine test aircraft, cabin noise is highly influenced by responses at the propeller tone, and cabin acoustic resonances can influence overall noise levels. Results from structural and acoustic finite element coupled models of the test aircraft show that wall flexibility has a strong influence on fundamental cabin acoustic resonances, the lightweight fuselage structure has a high modal density, and finite element analysis procedures are appropriate for the prediction of structural borne noise.

Design control for clinical translation of 3D printed modular scaffolds.

PubMed

Hollister, Scott J; Flanagan, Colleen L; Zopf, David A; Morrison, Robert J; Nasser, Hassan; Patel, Janki J; Ebramzadeh, Edward; Sangiorgio, Sophia N; Wheeler, Matthew B; Green, Glenn E

2015-03-01

The primary thrust of tissue engineering is the clinical translation of scaffolds and/or biologics to reconstruct tissue defects. Despite this thrust, clinical translation of tissue engineering therapies from academic research has been minimal in the 27 year history of tissue engineering. Academic research by its nature focuses on, and rewards, initial discovery of new phenomena and technologies in the basic research model, with a view towards generality. Translation, however, by its nature must be directed at specific clinical targets, also denoted as indications, with associated regulatory requirements. These regulatory requirements, especially design control, require that the clinical indication be precisely defined a priori, unlike most academic basic tissue engineering research where the research target is typically open-ended, and furthermore requires that the tissue engineering therapy be constructed according to design inputs that ensure it treats or mitigates the clinical indication. Finally, regulatory approval dictates that the constructed system be verified, i.e., proven that it meets the design inputs, and validated, i.e., that by meeting the design inputs the therapy will address the clinical indication. Satisfying design control requires (1) a system of integrated technologies (scaffolds, materials, biologics), ideally based on a fundamental platform, as compared to focus on a single technology, (2) testing of design hypotheses to validate system performance as opposed to mechanistic hypotheses of natural phenomena, and (3) sequential testing using in vitro, in vivo, large preclinical and eventually clinical tests against competing therapies, as compared to single experiments to test new technologies or test mechanistic hypotheses. Our goal in this paper is to illustrate how design control may be implemented in academic translation of scaffold based tissue engineering therapies. Specifically, we propose to (1) demonstrate a modular platform approach founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion.

Design Control for Clinical Translation of 3D Printed Modular Scaffolds

PubMed Central

Hollister, Scott J.; Flanagan, Colleen L.; Zopf, David A.; Morrison, Robert J.; Nasser, Hassan; Patel, Janki J.; Ebramzadeh, Edward; Sangiorgio, Sophia N.; Wheeler, Matthew B.; Green, Glenn E.

2015-01-01

The primary thrust of tissue engineering is the clinical translation of scaffolds and/or biologics to reconstruct tissue defects. Despite this thrust, clinical translation of tissue engineering therapies from academic research has been minimal in the 27 year history of tissue engineering. Academic research by its nature focuses on, and rewards, initial discovery of new phenomena and technologies in the basic research model, with a view towards generality. Translation, however, by its nature must be directed at specific clinical targets, also denoted as indications, with associated regulatory requirements. These regulatory requirements, especially design control, require that the clinical indication be precisely defined a priori, unlike most academic basic tissue engineering research where the research target is typically open-ended, and furthermore requires that the tissue engineering therapy be constructed according to design inputs that ensure it treats or mitigates the clinical indication. Finally, regulatory approval dictates that the constructed system be verified, i.e., proven that it meets the design inputs, and validated, i.e., that by meeting the design inputs the therapy will address the clinical indication. Satisfying design control requires (1) a system of integrated technologies (scaffolds, materials, biologics), ideally based on a fundamental platform, as compared to focus on a single technology, (2) testing of design hypotheses to validate system performance as opposed to mechanistic hypotheses of natural phenomena, and (3) sequential testing using in vitro, in vivo, large preclinical and eventually clinical tests against competing therapies, as compared to single experiments to test new technologies or test mechanistic hypotheses. Our goal in this paper is to illustrate how design control may be implemented in academic translation of scaffold based tissue engineering therapies. Specifically, we propose to (1) demonstrate a modular platform approach founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion. PMID:25666115

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

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

Life-Cycle Cost Database. Volume II. Appendices E, F, and G. Sample Data Development.

DTIC Science & Technology

1983-01-01

Bendix Field Engineering Corporation Columbia, Maryland 21045 5 CONTENTS Page GENERAL 8 Introduction Objective Engineering Survey SYSTEM DESCRIPTION...in a typical administrative type building over a 25-year period. 1.3 ENGINEERING SURVEY An on-site survey was conducted by Bendix Field Engineering...Damp Mop and Buff Buff Routine Vacuum Strip and Refinish Heavy Duty Vacuum Machine, Scrub and Surface Shampoo Pick Up Extraction Clean Repair Location

General Aviation Interior Noise. Part 3; Noise Control Measure Evaluation

NASA Technical Reports Server (NTRS)

Unruh, James F.; Till, Paul D.; Palumbo, Daniel L. (Technical Monitor)

2002-01-01

The work reported herein is an extension to the work accomplished under NASA Grant NAG1-2091 on the development of noise/source/path identification techniques for single engine propeller driven General Aviation aircraft. The previous work developed a Conditioned Response Analysis (CRA) technique to identify potential noise sources that contributed to the dominating tonal responses within the aircraft cabin. The objective of the present effort was to improve and verify the findings of the CRA and develop and demonstrate noise control measures for single engine propeller driven General Aviation aircraft.

Multi-Wavelength Optical Pyrometry Investigation for Turbine Engine Applications.

NASA Astrophysics Data System (ADS)

Estevadeordal, Jordi; Nirmalan, Nirm; Wang, Guanghua; Thermal Systems Team

2011-11-01

An investigation of optical Pyrometry using multiple wavelengths and its application to turbine engine is presented. Current turbine engine Pyrometers are typically broadband Si-detector line-of-sight (LOS) systems. They identify hot spots and spall areas in blades and bucket passages by detection of bursts of higher voltage signals. However, the single color signal can be misleading for estimating temperature and emissivity variations in these bursts. Results of the radiant temperature, multi-color temperature and apparent emissivity are presented for turbine engine applications. For example, the results indicate that spall regions can be characterized using multi-wavelength techniques by showing that the temperature typically drops and the emissivity increases and that differentiates from the emissivity of the normal regions. Burst signals are analyzed with multicolor algorithms and changes in the LOS hot-gas-path properties and in the suction side, trailing edge, pressure side, fillet and platform surfaces characterized.

DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL ...

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

DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL MOTORS ENGINE (LEFT)AND FERREL REDUCTION GEAR CONNECTION TO ALLIS-CHALMERS DIESEL ENGINE (RIGHT), LOOKING NORTH. NOTE TORQUE CONVERTER (TOP) AND THROTTLE (BELOW) LINES CONNECTING TO PRIMARY ENGINE. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

Proceedings of the Special Course on Missile Aerodynamics, Held in Rhode-Saint-Genese, Belgium on 30 March-3 April 1987, Held in Athens, Greece on 18-19 May 1987 Held in Ankara, Turkey on 21-22 May 1987

DTIC Science & Technology

1988-04-01

organized at VKI: 1974 IVKI LS67). 1970 (VKI LS88) and 1979 (AGARI) LS98). This course was intended for practical engineers and researchers, beginners ...TYPICAL SUBSYSTEM INTERNAL LAYOUTS FIGURE 6. FLOWCHART OF SHAPING LOGIC Ml 1-0 7624 SINGLE ENGINE TWIN ENGINE TOP VIEW TOP VIEW WARHEAD / _ SKEW -- ftG

Study of small turbofan engines applicable to single-engine light airplanes

NASA Technical Reports Server (NTRS)

Merrill, G. L.

1976-01-01

The design, efficiency and cost factors are investigated for application of turbofan propulsion engines to single engine, general aviation light airplanes. A companion study of a hypothetical engine family of a thrust range suitable to such aircraft and having a high degree of commonality of design features and parts is presented. Future turbofan powered light airplanes can have a lower fuel consumption, lower weight, reduced airframe maintenance requirements and improved engine overhaul periods as compared to current piston engined powered airplanes. Achievement of compliance with noise and chemical emission regulations is expected without impairing performance, operating cost or safety.

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

Sakaki, H.; Fukuda, Y.; Nishiuchi, M.

A single-shot-imaging thin scintillator film was developed for an online Thomson parabola (TP) spectrometer and the first analysis of laser accelerated ions, using the online TP spectrometer, was demonstrated at the JAEA-Kansai Advanced Relativistic Engineering Laser System (J-KAREN). An energy spectrum of {approx}4.0 MeV protons is obtained using only this imaging film without the need of a microchannel plate that is typically utilized in online ion analyses. A general-purpose Monte Carlo particle and heavy ion-transport code system, which consists of various quantum dynamics models, was used for the prediction of the luminescent properties of the scintillator. The simulation can reasonablymore » predict not only the ion trajectories detected by the spectrometer, but also luminescence properties.« 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

Advanced Propfan Engine Technology (APET) definition study, single and counter-rotation gearbox/pitch change mechanism design

NASA Technical Reports Server (NTRS)

Anderson, R. D.

1985-01-01

Single-rotation propfan-powered regional transport aircraft were studied to identify key technology development issues and programs. The need for improved thrust specific fuel consumption to reduce fuel burned and aircraft direct operating cost is the dominant factor. Typical cycle trends for minimizing fuel consumption are reviewed, and two 10,000 shp class engine configurations for propfan propulsion systems for the 1990's are presented. Recommended engine configurations are both three-spool design with dual spool compressors and free power turbines. The benefits of these new propulsion system concepts were evaluated using an advanced airframe, and results are compared for single-rotation propfan and turbofan advanced technology propulsion systems. The single-rotation gearbox is compared to a similar design with current technology to establish the benefits of the advanced gearbox technology. The conceptual design of the advanced pitch change mechanism identified a high pressure hydraulic system that is superior to the other contenders and completely external to the gearboxes.

Results of acoustic testing of the JT8D-109 refan engines

NASA Technical Reports Server (NTRS)

Burdsall, E. A.; Brochu, F. P.; Scaramella, V. M.

1975-01-01

A JT8D engine was modified to reduce jet noise levels by 6-8 PNdB at takeoff power without increasing fan generated noise levels. Designated the JT8D-109, the modified engines featured a larger single stage fan, and acoustic treatment in the fan discharge ducts. Noise levels were measured on an outdoor test facility for eight engine/acoustic treatment configurations. Compared to the baseline JT8D, the fully treated JT8D-109 showed reductions of 6 PNdB at takeoff, and 11 PNdB at a typical approach power setting.

Study of small turbofan engines applicable to single-engine light airplanes. Final report

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

Merrill, G.L.

1976-09-01

The design, efficiency and cost factors are investigated for application of turbofan propulsion engines to single engine, general aviation light airplanes. A companion study of a hypothetical engine family of a thrust range suitable to such aircraft and having a high degree of commonality of design features and parts is presented. Future turbofan powered light airplanes can have a lower fuel consumption, lower weight, reduced airframe maintenance requirements and improved engine overhaul periods as compared to current piston engined powered airplanes. Achievement of compliance with noise and chemical emission regulations is expected without impairing performance, operating cost or safety.

A 150 and 300 kW lightweight diesel aircraft engine design study

NASA Technical Reports Server (NTRS)

Brouwers, A. P.

1980-01-01

The diesel engine was reinvestigated as an aircraft powerplant through design study conducted to arrive at engine configurations and applicable advanced technologies. Two engines are discussed, a 300 kW six-cylinder engine for twin engine general aviation aircraft and a 150 kW four-cylinder engine for single engine aircraft. Descriptions of each engine include concept drawings, a performance analysis, stress and weight data, and a cost study. This information was used to develop two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consists of installation drawings, computer generated performance data, aircraft operating costs, and drawings of the resulting airplanes. The performance data show a vast improvement over current gasoline-powered aircraft.

Efficiency bounds for nonequilibrium heat engines

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

Mehta, Pankaj; Polkovnikov, Anatoli, E-mail: asp@bu.edu

2013-05-15

We analyze the efficiency of thermal engines (either quantum or classical) working with a single heat reservoir like an atmosphere. The engine first gets an energy intake, which can be done in an arbitrary nonequilibrium way e.g. combustion of fuel. Then the engine performs the work and returns to the initial state. We distinguish two general classes of engines where the working body first equilibrates within itself and then performs the work (ergodic engine) or when it performs the work before equilibrating (non-ergodic engine). We show that in both cases the second law of thermodynamics limits their efficiency. For ergodicmore » engines we find a rigorous upper bound for the efficiency, which is strictly smaller than the equivalent Carnot efficiency. I.e. the Carnot efficiency can be never achieved in single reservoir heat engines. For non-ergodic engines the efficiency can be higher and can exceed the equilibrium Carnot bound. By extending the fundamental thermodynamic relation to nonequilibrium processes, we find a rigorous thermodynamic bound for the efficiency of both ergodic and non-ergodic engines and show that it is given by the relative entropy of the nonequilibrium and initial equilibrium distributions. These results suggest a new general strategy for designing more efficient engines. We illustrate our ideas by using simple examples. -- Highlights: ► Derived efficiency bounds for heat engines working with a single reservoir. ► Analyzed both ergodic and non-ergodic engines. ► Showed that non-ergodic engines can be more efficient. ► Extended fundamental thermodynamic relation to arbitrary nonequilibrium processes.« less

40 CFR 94.104 - Test procedures for Category 2 marine engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... representative of typical in-use marine engine conditions. (c) Conduct testing at ambient temperatures from 13 °C... section that are necessary to comply with the general provisions of § 94.102. (e) Measure CO2 as described in 40 CFR 92.129 through the 2010 model year. Measure CO2 as specified in 40 CFR 1042.235 starting in...

40 CFR 94.104 - Test procedures for Category 2 marine engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... representative of typical in-use marine engine conditions. (c) Conduct testing at ambient temperatures from 13 °C... section that are necessary to comply with the general provisions of § 94.102. (e) Measure CO2 as described in 40 CFR 92.129 through the 2010 model year. Measure CO2 as specified in 40 CFR 1042.235 starting in...

40 CFR 94.104 - Test procedures for Category 2 marine engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... representative of typical in-use marine engine conditions. (c) Conduct testing at ambient temperatures from 13 °C... section that are necessary to comply with the general provisions of § 94.102. (e) Measure CO2 as described in 40 CFR 92.129 through the 2010 model year. Measure CO2 as specified in 40 CFR 1042.235 starting in...

Single-temperature quantum engine without feedback control.

PubMed

Yi, Juyeon; Talkner, Peter; Kim, Yong Woon

2017-08-01

A cyclically working quantum-mechanical engine that operates at a single temperature is proposed. Its energy input is delivered by a quantum measurement. The functioning of the engine does not require any feedback control. We analyze work, heat, and the efficiency of the engine for the case of a working substance that is governed by the laws of quantum mechanics and that can be adiabatically compressed and expanded. The obtained general expressions are exemplified for a spin in an adiabatically changing magnetic field and a particle moving in a potential with slowly changing shape.

Effect of propeller slipstream on the drag and performance of the engine cooling system for a general aviation twin-engine aircraft

NASA Technical Reports Server (NTRS)

Katz, J.; Corsiglia, V. R.; Barlow, P. R.

1980-01-01

The pressure recovery of incoming cooling air and the drag associated with engine cooling of a typical general aviation twin-engine aircraft was investigated experimentally. The semispan model was mounted vertically in the 40- by 80-Foot Wind Tunnel at Ames Research Center. The propeller was driven by an electric motor to provide thrust with low vibration levels for the cold-flow configuration. It was found that the propeller slipstream reduces the frontal air spillage around the blunt nacelle shape. Consequently, this slipstream effect promotes flow reattachment at the rear section of the engine nacelle and improves inlet pressure recovery. These effects are most pronounced at high angles of attack, that is, climb condition. For the cruise condition those improvements were more moderate.

Multi-fuel rotary engine for general aviation aircraft

NASA Technical Reports Server (NTRS)

Jones, C.; Ellis, D. R.; Meng, P. R.

1983-01-01

Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, on advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

Heterogeneous activation of H2O2 by defect-engineered TiO(2-x) single crystals for refractory pollutants degradation: A Fenton-like mechanism.

PubMed

Zhang, Ai-Yong; Lin, Tan; He, Yuan-Yi; Mou, Yu-Xuan

2016-07-05

The heterogeneous catalyst plays a key role in Fenton-like reaction for advanced oxidation of refractory pollutants in water treatment. Titanium dioxide (TiO2) is a typical semiconductor with high industrial importance due to its earth abundance, low cost and no toxicity. In this work, it is found that TiO2 can heterogeneously activate hydrogen peroxide (H2O2, E°=1.78 eV), a common chemical oxidant, to efficiently generate highly-powerful hydroxyl radical, OH (E(0)=2.80 eV), for advanced water treatment, when its crystal shape, exposed facet and oxygen-stoichiometry are finely tuned. The defect-engineered TiO2 single crystals exposed by high-energy {001} facets exhibited an excellent Fenton-like activity and stability for degrading typical refractory organic pollutants such as methyl orange and p-nitrophenol. Its defect-centered Fenton-like superiority is mainly attributed to the crystal oxygen-vacancy, single-crystalline structure and exposed polar {001} facet. Our findings could provide new chance to utilize TiO2 for Fenton-like technology, and develop novel heterogeneous catalyst for advanced water treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced general aviation comparative engine/airframe integration study

NASA Technical Reports Server (NTRS)

Huggins, G. L.; Ellis, D. R.

1981-01-01

The NASA Advanced Aviation Comparative Engine/Airframe Integration Study was initiated to help determine which of four promising concepts for new general aviation engines for the 1990's should be considered for further research funding. The engine concepts included rotary, diesel, spark ignition, and turboprop powerplants; a conventional state-of-the-art piston engine was used as a baseline for the comparison. Computer simulations of the performance of single and twin engine pressurized aircraft designs were used to determine how the various characteristics of each engine interacted in the design process. Comparisons were made of how each engine performed relative to the others when integrated into an airframe and required to fly a transportation mission.

A Closer Look at 804: A Summary of Considerations for DoD Program Managers

DTIC Science & Technology

2011-12-01

aimed at changing the culture from one that is fo- cused typically on a single delivery to a new model that comprises multiple deliveries to es...under the Agency CIOs, and de - velop flexible budget models that align with modular development. • Launch an interactive platform for pre-RFP agency...permission@sei.cmu.edu. TM Carnegie Mellon Software Engineering Institute (stylized), Carnegie Mellon Software Engineering Institute (and de - sign), Simplex

Numerical Simulations of Evaporating Sprays in High Pressure and Temperature Operating Conditions (Engine Combustion Network [ECN])

DTIC Science & Technology

2014-05-01

temperature effect in nonreacting and reacting diesel sprays using a novel injector , and imaging diagnostics for liquid phase penetration, light-off...ambient conditions. A single hole, modern common rail injector with an injector diameter of 90 µ (Bosch CRIN 2.4) is used at typical diesel injection... diesel engine operating conditions. The objective of this report is to demonstrate the modeling capability of a recently adopted 3D-Computational Fluid

Low-order nonlinear dynamic model of IC engine-variable pitch propeller system for general aviation aircraft

NASA Technical Reports Server (NTRS)

Richard, Jacques C.

1995-01-01

This paper presents a dynamic model of an internal combustion engine coupled to a variable pitch propeller. The low-order, nonlinear time-dependent model is useful for simulating the propulsion system of general aviation single-engine light aircraft. This model is suitable for investigating engine diagnostics and monitoring and for control design and development. Furthermore, the model may be extended to provide a tool for the study of engine emissions, fuel economy, component effects, alternative fuels, alternative engine cycles, flight simulators, sensors, and actuators. Results show that the model provides a reasonable representation of the propulsion system dynamics from zero to 10 Hertz.

Comparison of predicted and measured drag for a single-engine airplane

NASA Technical Reports Server (NTRS)

Ward, D. T.; Taylor, F. C.; Doo, J. T. P.

1985-01-01

Renewed interest in natural laminar flow (NLF) has rekindled designers' concerns that manufacturing deviations, (loss of surface contours or other surface imperfections) may destroy the effectiveness of NLF for an operational airplane. This paper reports on experimental research that compares predicted and measured boundary layer transition, total drag, and two-dimensional drag coefficients for three different wing surface conditions on an airplane typical of general aviation manufacturing technology. The three flight test phases included: (1) assessment of an unpainted airframe, (2) flight tests of the same airplane after painstakingly filling and sanding the wings to design contours, and (3) similar measurements after this airplane was painted. In each flight phase, transition locations were monitored using either sublimating chemicals or pigmented oil. As expected, total drag changes were difficult to measure. Two-dimensional drag coefficients were estimated using the Eppler-Somers code and measured with a wake rake in a method very similar to Jones' pitot traverse method. The net change in two-dimensional drag was approximately 20 counts between the unpainted airplane and the 'hand-smoothed' airplane for typical cruise flight conditions.

Building a Community of Scholars: One University's Comparison of "Typical" vs. Open Ended Ethics Case Studies in First-Year Engineering

ERIC Educational Resources Information Center

Reid, Kenneth J.

2012-01-01

Ethics is among the professional skills embedded in the first year engineering curriculum in many institutions. The general format of the study of ethics is similar to many other institutions: student teams review case studies and develop written and oral presentations on the ethical issues encountered. This report investigates whether the use of…

Effect of Tilt of the Propeller Axis on the Longitudinal-stability Characteristics of Single-Engine Airplanes

NASA Technical Reports Server (NTRS)

Goett, Harry J; Delaney, Noel K

1944-01-01

Report presents the results of tests of a model of a single-engine airplane with two different tilts of the propeller axis. The results indicate that on a typical design a 5 degree downward tilt of the propeller axis will considerably reduce the destabilization effects of power. A comparison of the experimental results with those computed by use of existing theory is included. A comparison of the experimental results with those computed by use of existing theory is included. It is shown that the results can be predicted with an accuracy acceptable for preliminary design purposes, particularly at the higher powers where the effects are of significant magnitude.

Space shuttle orbit maneuvering engine reusable thrust chamber. Task 13: Subscale helium ingestion and two dimensional heating test report

NASA Technical Reports Server (NTRS)

Tobin, R. D.

1974-01-01

Descriptions are given of the test hardware, facility, procedures, and results of electrically heated tube, channel and panel tests conducted to determine effects of helium ingestion, two dimensional conduction, and plugged coolant channels on operating limits of convectively cooled chambers typical of space shuttle orbit maneuvering engine designs. Helium ingestion in froth form, was studied in tubular and rectangular single channel test sections. Plugged channel simulation was investigated in a three channel panel. Burn-out limits (transition of film boiling) were studied in both single channel and panel test sections to determine 2-D conduction effects as compared to tubular test results.

Advanced radioisotope heat source for Stirling Engines

NASA Astrophysics Data System (ADS)

Dobry, T. J.; Walberg, G.

2001-02-01

The heat exchanger on a Stirling Engine requires a thermal energy transfer from a heat source to the engine through a very limited area on the heater head circumference. Designing an effective means to assure maximum transfer efficiency is challenging. A single General Purpose Heat Source (GPHS), which has been qualified for space operations, would satisfy thermal requirements for a single Stirling Engine that would produce 55 electrical watts. However, it is not efficient to transfer its thermal energy to the engine heat exchanger from its rectangular geometry. This paper describes a conceptual design of a heat source to improve energy transfer for Stirling Engines that may be deployed to power instrumentation on space missions. .

Single-beam thermal lens measurement of thermal diffusivity of engine coolants

NASA Astrophysics Data System (ADS)

George, Nibu A.; Thomas, Nibu B.; Chacko, Kavya; T, Neethu V.; Hussain Moidu, Haroon; Piyush, K.; David, Nitheesh M.

2015-04-01

Automobile engine coolant liquids are commonly used for efficient heat transfer from the engine to the surroundings. In this work we have investigated the thermal diffusivity of various commonly available engine coolants in Indian automobile market. We have used single beam laser induced thermal lens technique for the measurements. Engine coolants are generally available in concentrated solution form and are recommended to use at specified dilution. We have investigated the samples in the entire recommended concentration range for the use in radiators. While some of the brands show an enhanced thermal diffusivity compared to pure water, others show slight decrease in thermal diffusivity.

Dispersion of turbojet engine exhaust in flight

NASA Technical Reports Server (NTRS)

Holdeman, J. D.

1973-01-01

The dispersion of the exhaust of turbojet engines into the atmosphere is estimated by using a model developed for the mixing of a round jet with a parallel flow. The analysis is appropriate for determining the spread and dilution of the jet exhaust from the engine exit until it is entrained in the aircraft trailing vortices. Chemical reactions are not expected to be important and are not included in the flow model. Calculations of the dispersion of the exhaust plumes of three aircraft turbojet engines with and without afterburning at typical flight conditions are presented. Calculated average concentrations for the exhaust plume from a single engine jet fighter are shown to be in good agreement with measurements made in the aircraft wake during flight.

Single Common Powertrain Lubricant Development

DTIC Science & Technology

2012-01-01

2 2.2 ENGINE DURABILITY TESTING...Page Figure 1 – General Engine Products 6.5L(T) Test Cell Installation ............................................... 9 Figure 2 ... 2 Run 3 Repeatability Run - 1 Repeatability Run - 2 Repeatability Run - 3 3-Run Average Engine Oil Consumption [lb/hr] 0.061 0.082 0.086 0.076

A fuel-efficient cruise performance model for general aviation piston engine airplanes. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Parkinson, R. C. H.

1983-01-01

A fuel-efficient cruise performance model which facilitates maximizing the specific range of General Aviation airplanes powered by spark-ignition piston engines and propellers is presented. Airplanes of fixed design only are considered. The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its implicity and low volume data storge requirements, appears suitable for airborne microprocessor implementation.

Protein mechanics: from single molecules to functional biomaterials.

PubMed

Li, Hongbin; Cao, Yi

2010-10-19

Elastomeric proteins act as the essential functional units in a wide variety of biomechanical machinery and serve as the basic building blocks for biological materials that exhibit superb mechanical properties. These proteins provide the desired elasticity, mechanical strength, resilience, and toughness within these materials. Understanding the mechanical properties of elastomeric protein-based biomaterials is a multiscale problem spanning from the atomistic/molecular level to the macroscopic level. Uncovering the design principles of individual elastomeric building blocks is critical both for the scientific understanding of multiscale mechanics of biomaterials and for the rational engineering of novel biomaterials with desirable mechanical properties. The development of single-molecule force spectroscopy techniques has provided methods for characterizing mechanical properties of elastomeric proteins one molecule at a time. Single-molecule atomic force microscopy (AFM) is uniquely suited to this purpose. Molecular dynamic simulations, protein engineering techniques, and single-molecule AFM study have collectively revealed tremendous insights into the molecular design of single elastomeric proteins, which can guide the design and engineering of elastomeric proteins with tailored mechanical properties. Researchers are focusing experimental efforts toward engineering artificial elastomeric proteins with mechanical properties that mimic or even surpass those of natural elastomeric proteins. In this Account, we summarize our recent experimental efforts to engineer novel artificial elastomeric proteins and develop general and rational methodologies to tune the nanomechanical properties of elastomeric proteins at the single-molecule level. We focus on general design principles used for enhancing the mechanical stability of proteins. These principles include the development of metal-chelation-based general methodology, strategies to control the unfolding hierarchy of multidomain elastomeric proteins, and the design of novel elastomeric proteins that exhibit stimuli-responsive mechanical properties. Moving forward, we are now exploring the use of these artificial elastomeric proteins as building blocks of protein-based biomaterials. Ultimately, we would like to rationally tailor mechanical properties of elastomeric protein-based materials by programming the molecular sequence, and thus nanomechanical properties, of elastomeric proteins at the single-molecule level. This step would help bridge the gap between single protein mechanics and material biomechanics, revealing how the mechanical properties of individual elastomeric proteins are translated into the properties of macroscopic materials.

Propeller swirl effect on single-engine general-aviation aircraft stall-spin tendencies

NASA Technical Reports Server (NTRS)

Katz, Joseph; Feistel, Terry W.

1987-01-01

An investigation is conducted of the effect of a single engine, untapered low wing general aviation aircraft propeller's swirl on the craft's stall pattern. The asymmetrical character of the propeller's swirl can trigger an early stall of one of the wings, aggravating the spin-entry condition. It is shown that the combination of this propeller-induced effect with adverse sideslip can result in large and abrupt changes in the rolling moment, in such conditions as uncoordinated low speed turning maneuvers where the pilot yaws the aircraft with wings level, rather than rolling it.

Multi-fuel rotary engine for general aviation aircraft

NASA Technical Reports Server (NTRS)

Jones, C.; Ellis, D. R.; Meng, P. R.

1983-01-01

Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, an advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25,000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed. Previously announced in STAR as N83-18910

Fuel-efficient cruise performance model for general aviation piston engine airplanes

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

Parkinson, R.C.H.

1982-01-01

The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its simplicity and low volume data storage requirements, appears suitable for airborne microprocessor implementation.

General aviation avionics equipment maintenance

NASA Technical Reports Server (NTRS)

Parker, C. D.; Tommerdahl, J. B.

1978-01-01

Maintenance of general aviation avionics equipment was investigated with emphasis on single engine and light twin engine general aviation aircraft. Factors considered include the regulatory agencies, avionics manufacturers, avionics repair stations, the statistical character of the general aviation community, and owners and operators. The maintenance, environment, and performance, repair costs, and reliability of avionics were defined. It is concluded that a significant economic stratification is reflected in the maintenance problems encountered, that careful attention to installations and use practices can have a very positive impact on maintenance problems, and that new technologies and a general growth in general aviation will impact maintenance.

A Co-modeling Method Based on Component Features for Mechatronic Devices in Aero-engines

NASA Astrophysics Data System (ADS)

Wang, Bin; Zhao, Haocen; Ye, Zhifeng

2017-08-01

Data-fused and user-friendly design of aero-engine accessories is required because of their structural complexity and stringent reliability. This paper gives an overview of a typical aero-engine control system and the development process of key mechatronic devices used. Several essential aspects of modeling and simulation in the process are investigated. Considering the limitations of a single theoretic model, feature-based co-modeling methodology is suggested to satisfy the design requirements and compensate for diversity of component sub-models for these devices. As an example, a stepper motor controlled Fuel Metering Unit (FMU) is modeled in view of the component physical features using two different software tools. An interface is suggested to integrate the single discipline models into the synthesized one. Performance simulation of this device using the co-model and parameter optimization for its key components are discussed. Comparison between delivery testing and the simulation shows that the co-model for the FMU has a high accuracy and the absolute superiority over a single model. Together with its compatible interface with the engine mathematical model, the feature-based co-modeling methodology is proven to be an effective technical measure in the development process of the device.

Technology Assessment of Avanced propulsion Systems for Some Classes of Combat Vehicles. Volume 3. Appendices G-M.

DTIC Science & Technology

1978-09-01

generally recognized that the best possible configura- tion for engines operating at high speeds and at high-pressure levels is probably the single...engines is invariably accom- plished by the operation of computer simulation models that generate specific numerical data rather than the generalized re...lationships common to other forms of prime mover based on units of mass or volume. Thus, providing such generalized relation- ships for a Stirling

The role of semantic complexity in treatment of naming deficits: training semantic categories in fluent aphasia by controlling exemplar typicality.

PubMed

Kiran, Swathi; Thompson, Cynthia K

2003-06-01

The effect of typicality of category exemplars on naming was investigated using a single subject experimental design across participants and behaviors in 4 patients with fluent aphasia. Participants received a semantic feature treatment to improve naming of either typical or atypical items within semantic categories, while generalization was tested to untrained items of the category. The order of typicality and category trained was counterbalanced across participants. Results indicated that patients trained on naming of atypical exemplars demonstrated generalization to naming of intermediate and typical items. However, patients trained on typical items demonstrated no generalized naming effect to intermediate or atypical examples. Furthermore, analysis of errors indicated an evolution of errors throughout training, from those with no apparent relationship to the target to primarily semantic and phonemic paraphasias. Performance on standardized language tests also showed changes as a function of treatment. Theoretical and clinical implications regarding the impact of considering semantic complexity on rehabilitation of naming deficits in aphasia are discussed.

The role of semantic complexity in treatment of naming deficits: training semantic categories in fluent aphasia by controlling exemplar typicality.

PubMed

Kiran, Swathi; Thompson, Cynthia K

2003-08-01

The effect of typicality of category exemplars on naming was investigated using a single subject experimental design across participants and behaviors in 4 patients with fluent aphasia. Participants received a semantic feature treatment to improve naming of either typical or atypical items within semantic categories, while generalization was tested to untrained items of the category. The order of typicality and category trained was counterbalanced across participants. Results indicated that patients trained on naming of atypical exemplars demonstrated generalization to naming of intermediate and typical items. However, patients trained on typical items demonstrated no generalized naming effect to intermediate or atypical examples. Furthermore, analysis of errors indicated an evolution of errors throughout training, from those with no apparent relationship to the target to primarily semantic and phonemic paraphasias. Performance on standardized language tests also showed changes as a function of treatment. Theoretical and clinical implications regarding the impact of considering semantic complexity on rehabilitation of naming deficits in aphasia are discussed.

Typical Local Measurements in Generalized Probabilistic Theories: Emergence of Quantum Bipartite Correlations

NASA Astrophysics Data System (ADS)

Kleinmann, Matthias; Osborne, Tobias J.; Scholz, Volkher B.; Werner, Albert H.

2013-01-01

What singles out quantum mechanics as the fundamental theory of nature? Here we study local measurements in generalized probabilistic theories (GPTs) and investigate how observational limitations affect the production of correlations. We find that if only a subset of typical local measurements can be made then all the bipartite correlations produced in a GPT can be simulated to a high degree of accuracy by quantum mechanics. Our result makes use of a generalization of Dvoretzky’s theorem for GPTs. The tripartite correlations can go beyond those exhibited by quantum mechanics, however.

Thermal-structural analyses of Space Shuttle Main Engine (SSME) hot section components

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Thompson, Robert L.

1988-01-01

Three dimensional nonlinear finite element heat transfer and structural analyses were performed for the first stage high pressure fuel turbopump (HPFTP) blade of the space shuttle main engine (SSME). Directionally solidified (DS) MAR-M 246 and single crystal (SC) PWA-1480 material properties were used for the analyses. Analytical conditions were based on a typical test stand engine cycle. Blade temperature and stress strain histories were calculated by using the MARC finite element computer code. The structural response of an SSME turbine blade was assessed and a greater understanding of blade damage mechanisms, convective cooling effects, and thermal mechanical effects was gained.

An Interdisciplinary Practical for Multimedia Engineering Students

ERIC Educational Resources Information Center

Marcos-Jorquera, Diego; Pertegal-Felices, María Luisa; Jimeno-Morenilla, Antonio; Gilar-Corbí, Raquel

2017-01-01

Interdisciplinary projects in the industry typically require collaboration between professionals from various fields. However, this relationship is not generally addressed in the training offered by university programs, which often ignore this interdisciplinary approach. This paper offers an example of interdisciplinary interaction through joint…

Investigation of Icing Characteristics of Typical Light Airplane Engine Induction Systems

NASA Technical Reports Server (NTRS)

Coles, W. D.

1949-01-01

The icing characteristics of two typical light-airplane engine induction systems were investigated using the carburetors and manifolds of engines in the horsepower ranges from 65 to 85 and 165 to 185. The smaller system consisted of a float-type carburetor with an unheated manifold and the larger system consisted of a single-barrel pressure-type carburetor with an oil-jacketed manifold. Carburetor-air temperature and humidity limits of visible and serious Icing were determined for various engine power conditions. Several.methods of achieving ice-free induction systems are discussed along with estimates of surface heating requirements of the various induct ion-system components. A study was also made of the icing characteristics of a typical light-airplane air scoop with an exposed filter and a modified system that provided a normal ram inlet with the filter located in a position to Induce inertia separation of the free water from the charge air. The principle of operation of float-type carburetors is proved to make them inherently more susceptible to icing at the throttle plate than pressure-type carburetors.. The results indicated that proper jacketing and heating of all parts exposed to the fuel spray can satisfactorily reduce or eliminate icing in the float-type carburetor and the manifold. Pressure-type carburetors can be protected from serious Icing by proper location of the fuel-discharge nozzle combined with suitable application of heat to critical parts.

Assessment of advanced technologies for high performance single-engine business airplanes

NASA Technical Reports Server (NTRS)

Kohlman, D. L.; Holmes, B. J.

1982-01-01

The prospects for significantly increasing the fuel efficiency and mission capability of single engine business aircraft through the incorporation of advanced propulsion, aerodynamics and materials technologies are explored. It is found that turbine engines cannot match the fuel economy of the heavier rotary, diesel and advanced spark reciprocating engines. The rotary engine yields the lightest and smallest aircraft for a given mission requirement, and also offers greater simplicity and a multifuel capability. Great promise is also seen in the use of composite material primary structures in conjunction with laminar flow wing surfaces, a pusher propeller and conventional wing-tail configuration. This study was conducted with the General Aviation Synthesis Program, which can furnish the most accurate mission performance calculations yet obtained.

Conceptual design of single turbofan engine powered light aircraft

NASA Technical Reports Server (NTRS)

Snyder, F. S.; Voorhees, C. G.; Heinrich, A. M.; Baisden, D. N.

1977-01-01

The conceptual design of a four place single turbofan engine powered light aircraft was accomplished utilizing contemporary light aircraft conventional design techniques as a means of evaluating the NASA-Ames General Aviation Synthesis Program (GASP) as a preliminary design tool. In certain areas, disagreement or exclusion were found to exist between the results of the conventional design and GASP processes. Detail discussion of these points along with the associated contemporary design methodology are presented.

On the transition between two-phase and single-phase interface dynamics in multicomponent fluids at supercritical pressures

NASA Astrophysics Data System (ADS)

Dahms, Rainer N.; Oefelein, Joseph C.

2013-09-01

A theory that explains the operating pressures where liquid injection processes transition from exhibiting classical two-phase spray atomization phenomena to single-phase diffusion-dominated mixing is presented. Imaging from a variety of experiments have long shown that under certain conditions, typically when the pressure of the working fluid exceeds the thermodynamic critical pressure of the liquid phase, the presence of discrete two-phase flow processes become diminished. Instead, the classical gas-liquid interface is replaced by diffusion-dominated mixing. When and how this transition occurs, however, is not well understood. Modern theory still lacks a physically based model to quantify this transition and the precise mechanisms that lead to it. In this paper, we derive a new model that explains how the transition occurs in multicomponent fluids and present a detailed analysis to quantify it. The model applies a detailed property evaluation scheme based on a modified 32-term Benedict-Webb-Rubin equation of state that accounts for the relevant real-fluid thermodynamic and transport properties of the multicomponent system. This framework is combined with Linear Gradient Theory, which describes the detailed molecular structure of the vapor-liquid interface region. Our analysis reveals that the two-phase interface breaks down not necessarily due to vanishing surface tension forces, but due to thickened interfaces at high subcritical temperatures coupled with an inherent reduction of the mean free molecular path. At a certain point, the combination of reduced surface tension, the thicker interface, and reduced mean free molecular path enter the continuum length scale regime. When this occurs, inter-molecular forces approach that of the multicomponent continuum where transport processes dominate across the interfacial region. This leads to a continuous phase transition from compressed liquid to supercritical mixture states. Based on this theory, a regime diagram for liquid injection is developed that quantifies the conditions under which classical sprays transition to dense-fluid jets. It is shown that the chamber pressure required to support diffusion-dominated mixing dynamics depends on the composition and temperature of the injected liquid and ambient gas. To illustrate the method and analysis, we use conditions typical of diesel engine injection. We also present a companion set of high-speed images to provide experimental validation of the presented theory. The basic theory is quite general and applies to a wide range of modern propulsion and power systems such as liquid rockets, gas turbines, and reciprocating engines. Interestingly, the regime diagram associated with diesel engine injection suggests that classical spray phenomena at typical injection conditions do not occur.

33 CFR 238.6 - General policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... system of pipes traditionally recognized as a storm drainage system. Flood damage reduction works... ditches with carrying capacities typical of storm sewer pipes. Location of political boundaries will not... the Corps of Engineers. (2) Construction of storm sewer systems and components thereof will be a non...

33 CFR 238.6 - General policy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... system of pipes traditionally recognized as a storm drainage system. Flood damage reduction works... ditches with carrying capacities typical of storm sewer pipes. Location of political boundaries will not... the Corps of Engineers. (2) Construction of storm sewer systems and components thereof will be a non...

33 CFR 238.6 - General policy.

Code of Federal Regulations, 2014 CFR

2014-07-01

... system of pipes traditionally recognized as a storm drainage system. Flood damage reduction works... ditches with carrying capacities typical of storm sewer pipes. Location of political boundaries will not... the Corps of Engineers. (2) Construction of storm sewer systems and components thereof will be a non...

33 CFR 238.6 - General policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... system of pipes traditionally recognized as a storm drainage system. Flood damage reduction works... ditches with carrying capacities typical of storm sewer pipes. Location of political boundaries will not... the Corps of Engineers. (2) Construction of storm sewer systems and components thereof will be a non...

33 CFR 238.6 - General policy.

Code of Federal Regulations, 2013 CFR

2013-07-01

... system of pipes traditionally recognized as a storm drainage system. Flood damage reduction works... ditches with carrying capacities typical of storm sewer pipes. Location of political boundaries will not... the Corps of Engineers. (2) Construction of storm sewer systems and components thereof will be a non...

An inventory of aeronautical ground research facilities. Volume 4: Engineering flight simulation facilities

NASA Technical Reports Server (NTRS)

Pirrello, C. J.; Hardin, R. D.; Capelluro, L. P.; Harrison, W. D.

1971-01-01

The general purpose capabilities of government and industry in the area of real time engineering flight simulation are discussed. The information covers computer equipment, visual systems, crew stations, and motion systems, along with brief statements of facility capabilities. Facility construction and typical operational costs are included where available. The facilities provide for economical and safe solutions to vehicle design, performance, control, and flying qualities problems of manned and unmanned flight systems.

End-to-end imaging information rate advantages of various alternative communication systems

NASA Technical Reports Server (NTRS)

Rice, R. F.

1982-01-01

The efficiency of various deep space communication systems which are required to transmit both imaging and a typically error sensitive class of data called general science and engineering (gse) are compared. The approach jointly treats the imaging and gse transmission problems, allowing comparisons of systems which include various channel coding and data compression alternatives. Actual system comparisons include an advanced imaging communication system (AICS) which exhibits the rather significant advantages of sophisticated data compression coupled with powerful yet practical channel coding. For example, under certain conditions the improved AICS efficiency could provide as much as two orders of magnitude increase in imaging information rate compared to a single channel uncoded, uncompressed system while maintaining the same gse data rate in both systems. Additional details describing AICS compression and coding concepts as well as efforts to apply them are provided in support of the system analysis.

The Use of Steady and Unsteady Detonation Waves for Propulsion Systems

NASA Technical Reports Server (NTRS)

Adelman, Henry G.; Menees, Gene P.; Cambier, Jean-Luc; Bowles, Jeffrey V.; Cavolowsky, John A. (Technical Monitor)

1995-01-01

Detonation wave enhanced supersonic combustors such as the Oblique Detonation Wave Engine (ODWE) are attractive propulsion concepts for hypersonic flight. These engines utilize detonation waves to enhance fuel-air mixing and combustion. The benefits of wave combustion systems include shorter and lighter engines which require less cooling and generate lower internal drag. These features allow air-breathing operation at higher Mach numbers than the diffusive burning scramjet delaying the need for rocket engine augmentation. A comprehensive vehicle synthesis code has predicted the aerodynamic characteristics and structural size and weight of a typical single-stage-to-orbit vehicle using an ODWE. Other studies have focused on the use of unsteady or pulsed detonation waves. For low speed applications, pulsed detonation engines (PDE) have advantages in low weight and higher efficiency than turbojets. At hypersonic speeds, the pulsed detonations can be used in conjunction with a scramjet type engine to enhance mixing and provide thrust augmentation.

Economical launching and accelerating control strategy for a single-shaft parallel hybrid electric bus

NASA Astrophysics Data System (ADS)

Yang, Chao; Song, Jian; Li, Liang; Li, Shengbo; Cao, Dongpu

2016-08-01

This paper presents an economical launching and accelerating mode, including four ordered phases: pure electrical driving, clutch engagement and engine start-up, engine active charging, and engine driving, which can be fit for the alternating conditions and improve the fuel economy of hybrid electric bus (HEB) during typical city-bus driving scenarios. By utilizing the fast response feature of electric motor (EM), an adaptive controller for EM is designed to realize the power demand during the pure electrical driving mode, the engine starting mode and the engine active charging mode. Concurrently, the smoothness issue induced by the sequential mode transitions is solved with a coordinated control logic for engine, EM and clutch. Simulation and experimental results show that the proposed launching and accelerating mode and its control methods are effective in improving the fuel economy and ensure the drivability during the fast transition between the operation modes of HEB.

Rapid directed evolution of stabilized proteins with cellular high-throughput encapsulation solubilization and screening (CHESS).

PubMed

Yong, K J; Scott, D J

2015-03-01

Directed evolution is a powerful method for engineering proteins towards user-defined goals and has been used to generate novel proteins for industrial processes, biological research and drug discovery. Typical directed evolution techniques include cellular display, phage display, ribosome display and water-in-oil compartmentalization, all of which physically link individual members of diverse gene libraries to their translated proteins. This allows the screening or selection for a desired protein function and subsequent isolation of the encoding gene from diverse populations. For biotechnological and industrial applications there is a need to engineer proteins that are functional under conditions that are not compatible with these techniques, such as high temperatures and harsh detergents. Cellular High-throughput Encapsulation Solubilization and Screening (CHESS), is a directed evolution method originally developed to engineer detergent-stable G proteins-coupled receptors (GPCRs) for structural biology. With CHESS, library-transformed bacterial cells are encapsulated in detergent-resistant polymers to form capsules, which serve to contain mutant genes and their encoded proteins upon detergent mediated solubilization of cell membranes. Populations of capsules can be screened like single cells to enable rapid isolation of genes encoding detergent-stable protein mutants. To demonstrate the general applicability of CHESS to other proteins, we have characterized the stability and permeability of CHESS microcapsules and employed CHESS to generate thermostable, sodium dodecyl sulfate (SDS) resistant green fluorescent protein (GFP) mutants, the first soluble proteins to be engineered using CHESS. © 2014 Wiley Periodicals, Inc.

Response Sensitivity of Typical Aircraft Jet Engine Fan Blade-Like Structures to Bird Impacts.

DTIC Science & Technology

1982-05-01

AIRCRAFT ENGINE BU--ETC F/G 21/5 RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -L...SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -LIKE STRUCTURES TO BIRD IMPACTS David P. Bauer Robert S. Bertke University of Dayton Research...COVERED RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT FINAL REPORT JET ENGINE FAN BLADE -LIKE STRUCTURES Oct. 1977 to Jan. 1979 TO BIRD IMPACTS s.

Multi-Fuel Rotary Engine for General Aviation Aircraft

NASA Technical Reports Server (NTRS)

Jones, C.; Ellis, D. R.; Meng, P. R.

1983-01-01

Design studies, conducted for NASA, of Advanced Multi-fuel General Aviation and Commuter Aircraft Rotary Stratified Charge Engines are summarized. Conceptual design studies of an advanced engine sized to provide 186/250 shaft KW/HP under cruise conditions at 7620/25,000 m/ft. altitude were performed. Relevant engine development background covering both prior and recent engine test results of the direct injected unthrottled rotary engine technology, including the capability to interchangeably operate on gasoline, diesel fuel, kerosene, or aviation jet fuel, are presented and related to growth predictions. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 30 to 35% fuel economy improvement for the Rotary-engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

NASA Technical Reports Server (NTRS)

Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

1972-01-01

The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

NASA and general aviation

NASA Technical Reports Server (NTRS)

Ethell, J. L.

1986-01-01

General aviation remains the single most misunderstood sector of aeronautics in the United States. A detailed look at how general aviation functions and how NASA helps keep it on the cutting edge of technology in airfoils, airframes, commuter travel, environmental concerns, engines, propellers, air traffic control, agricultural development, electronics, and safety is given.

40 CFR 461.2 - General definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY General Provisions § 461.2 General definitions. In...) “Battery” means a modular electric power source where part or all of the fuel is contained within the unit... heat cycle engine. In this regulation there is no differentiation between a single cell and a battery...

40 CFR 461.2 - General definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY General Provisions § 461.2 General definitions. In...) “Battery” means a modular electric power source where part or all of the fuel is contained within the unit... heat cycle engine. In this regulation there is no differentiation between a single cell and a battery...

Quantum thermodynamic cycles and quantum heat engines. II.

PubMed

Quan, H T

2009-04-01

We study the quantum-mechanical generalization of force or pressure, and then we extend the classical thermodynamic isobaric process to quantum-mechanical systems. Based on these efforts, we are able to study the quantum version of thermodynamic cycles that consist of quantum isobaric processes, such as the quantum Brayton cycle and quantum Diesel cycle. We also consider the implementation of the quantum Brayton cycle and quantum Diesel cycle with some model systems, such as single particle in a one-dimensional box and single-mode radiation field in a cavity. These studies lay the microscopic (quantum-mechanical) foundation for Szilard-Zurek single-molecule engine.

The effects of engineering fabric in street pavement on low bearing capacity soil in New Orleans : executive summary.

DOT National Transportation Integrated Search

1985-07-01

Subsurface soil in the New Orleans area is generally composed of peat and clay. The low bearing capacity of the soft natural soil has caused early deterioration of asphaltic concrete pavements which typically fail prior to carrying their designed loa...

157. ARAIII Reactor building (ARA608) Main gas loop mechanical flow ...

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

157. ARA-III Reactor building (ARA-608) Main gas loop mechanical flow sheet. This drawing was selected as a typical example of mechanical arrangements within reactor building. Aerojet-general 880-area/GCRE-0608-50-013-102634. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Fuel conservation through active control of rotor clearances

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Saunders, A. A.; Wanger, R. P.

1980-01-01

Under the NASA-sponsored Energy Efficient Engine (EEE) Project, technology is being developed which will significantly reduce the fuel consumption of turbofan engines for subsonic transport aircraft. One technology concept being pursued is active control of rotor tip clearances. Attention is given to rotor tip clearance considerations and an overview of preliminary study results as well as the General Electric EEE clearance control approach is presented. Finally, potential fuel savings with active control of rotor clearances for a typical EEE mission are predicted.

Quantum state engineering using one-dimensional discrete-time quantum walks

NASA Astrophysics Data System (ADS)

Innocenti, Luca; Majury, Helena; Giordani, Taira; Spagnolo, Nicolò; Sciarrino, Fabio; Paternostro, Mauro; Ferraro, Alessandro

2017-12-01

Quantum state preparation in high-dimensional systems is an essential requirement for many quantum-technology applications. The engineering of an arbitrary quantum state is, however, typically strongly dependent on the experimental platform chosen for implementation, and a general framework is still missing. Here we show that coined quantum walks on a line, which represent a framework general enough to encompass a variety of different platforms, can be used for quantum state engineering of arbitrary superpositions of the walker's sites. We achieve this goal by identifying a set of conditions that fully characterize the reachable states in the space comprising walker and coin and providing a method to efficiently compute the corresponding set of coin parameters. We assess the feasibility of our proposal by identifying a linear optics experiment based on photonic orbital angular momentum technology.

Full-Authority Fault-Tolerant Electronic Engine Control System for Variable Cycle Engines.

DTIC Science & Technology

1982-04-01

single internally self-checked VLSI micro - processor . The selected configuration is an externally checked pair of com- mercially available...Electronic Engine Control FPMH Failures per Million Hours FTMP Fault Tolerant Multi- Processor FTSC Fault Tolerant Spaceborn Computer GRAMP Generalized...Removal * MTBR Mean Time Between Repair MTTF Mean Time to Failure xiii List of Abbreviations (continued) - NH High Pressure Rotor Speed O&S Operating

A combinatorial histidine scanning library approach to engineer highly pH-dependent protein switches

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

Murtaugh, Megan L.; Fanning, Sean W.; Sharma, Tressa M.

2012-09-05

There is growing interest in the development of protein switches, which are proteins whose function, such as binding a target molecule, can be modulated through environmental triggers. Efforts to engineer highly pH sensitive protein-protein interactions typically rely on the rational introduction of ionizable groups in the protein interface. Such experiments are typically time intensive and often sacrifice the protein's affinity at the permissive pH. The underlying thermodynamics of proton-linkage dictate that the presence of multiple ionizable groups, which undergo a pK{sub a} change on protein binding, are necessary to result in highly pH-dependent binding. To test this hypothesis, a novelmore » combinatorial histidine library was developed where every possible combination of histidine and wild-type residue is sampled throughout the interface of a model anti-RNase A single domain VHH antibody. Antibodies were coselected for high-affinity binding and pH-sensitivity using an in vitro, dual-function selection strategy. The resulting antibodies retained near wild-type affinity yet became highly sensitive to small decreases in pH, drastically decreasing their binding affinity, due to the incorporation of multiple histidine groups. Several trends were observed, such as histidine 'hot-spots,' which will help enhance the development of pH switch proteins as well as increase our understanding of the role of ionizable residues in protein interfaces. Overall, the combinatorial approach is rapid, general, and robust and should be capable of producing highly pH-sensitive protein affinity reagents for a number of different applications.« less

Mixing of multiple jets with a confined subsonic crossflow - Summary of NASA-supported experiments and modeling

NASA Technical Reports Server (NTRS)

Holdeman, James D.

1991-01-01

Experimental and computational results on the mixing of single, double, and opposed rows of jets with an isothermal or variable temperature mainstream in a confined subsonic crossflow are summarized. The studies were performed to investigate flow and geometric variations typical of the complex 3D flowfield in the dilution zone of combustion chambers in gas turbine engines. The principal observations from the experiments were that the momentum-flux ratio was the most significant flow variable, and that temperature distributions were similar (independent of orifice diameter) when the orifice spacing and the square-root of the momentum-flux ratio were inversely proportional. The experiments and empirical model for the mixing of a single row of jets from round holes were extended to include several variations typical of gas turbine combustors.

Mechanic watches a General Electric I-40 Engine Fire

NASA Image and Video Library

1948-01-21

A mechanic watches the firing of a General Electric I-40 turbojet at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The military selected General Electric’s West Lynn facility in 1941 to secretly replicate the centrifugal turbojet engine designed by British engineer Frank Whittle. General Electric’s first attempt, the I-A, was fraught with problems. The design was improved somewhat with the subsequent I-16 engine. It was not until the engine's next reincarnation as the I-40 in 1943 that General Electric’s efforts paid off. The 4000-pound thrust I-40 was incorporated into the Lockheed Shooting Star airframe and successfully flown in June 1944. The Shooting Star became the US’s first successful jet aircraft and the first US aircraft to reach 500 miles per hour. NACA Lewis studied all of General Electric’s centrifugal turbojet models during the 1940s. In 1945 the entire Shooting Star aircraft was investigated in the Altitude Wind Tunnel. Engine compressor performance and augmentation by water injection; comparison of different fuel blends in a single combustor; and air-cooled rotors were studied. The mechanic in this photograph watches the firing of a full-scale I-40 in the Jet Propulsion Static Laboratory. The facility was quickly built in 1943 specifically in order to test the early General Electric turbojets. The I-A was secretly analyzed in the facility during the fall of 1943.

Dynamic characteristics of single crystal SSME blades

NASA Technical Reports Server (NTRS)

Moss, L. A.; Smith, T. E.

1987-01-01

The Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) blades are currently manufactured using a directionally solidified (DS) material, MAR-M-246+Hf. However, a necessity to reduce the occurrence of fatigue cracking within the DS blades has lead to an interest in the use of a single crystal (SC) material, PWA-1480. A study was initiated to determine the dynamic characteristics of the HPFTP blades made of SC material and find possible critical engine order excitations. This study examined both the first and second stage drive turbine blades of the HPFTP. The dynamic characterization was done analytically as well as experimentally. The analytical study examined the SC first stage HPFTP blade dynamic characteristics under typical operating conditions. The blades were analyzed using MSC/NASTRAN and a finite element model. Two operating conditions, 27500 RPM and 35000 RPM, were investigated.

Things fall apart: biological species form unconnected parsimony networks.

PubMed

Hart, Michael W; Sunday, Jennifer

2007-10-22

The generality of operational species definitions is limited by problematic definitions of between-species divergence. A recent phylogenetic species concept based on a simple objective measure of statistically significant genetic differentiation uses between-species application of statistical parsimony networks that are typically used for population genetic analysis within species. Here we review recent phylogeographic studies and reanalyse several mtDNA barcoding studies using this method. We found that (i) alignments of DNA sequences typically fall apart into a separate subnetwork for each Linnean species (but with a higher rate of true positives for mtDNA data) and (ii) DNA sequences from single species typically stick together in a single haplotype network. Departures from these patterns are usually consistent with hybridization or cryptic species diversity.

Submarine Construction (Unterseebootsbau)

DTIC Science & Technology

1972-08-01

PIPE FOR THE SNORKEL EXHAUST MAST 11 AIR EXIT (GENERALLY TO MAIN AIR INDUCTION LINE) 12 EXHAUST GAS INLET FROM EXHAUST GAS LINE SIDE VIEW (MAST...Electric Engine 76 Diesel Engines 79 Air Intake and Gas Exhaust Systems for the Diesel Engines 79 Diesel Fuel and Pressurized Water System 82...Lines of a Submarine ■. 31 Figure 6 - Lines of a Submersible 31 Figure 7 - Twin- Screw Stern Configurations 34 Figure 8 - Single- Screw Stern

EGADS: A microcomputer program for estimating the aerodynamic performance of general aviation aircraft

NASA Technical Reports Server (NTRS)

Melton, John E.

1994-01-01

EGADS is a comprehensive preliminary design tool for estimating the performance of light, single-engine general aviation aircraft. The software runs on the Apple Macintosh series of personal computers and assists amateur designers and aeronautical engineering students in performing the many repetitive calculations required in the aircraft design process. The program makes full use of the mouse and standard Macintosh interface techniques to simplify the input of various design parameters. Extensive graphics, plotting, and text output capabilities are also included.

Multilayer Network Modeling of Change Propagation for Engineering Change Management

DTIC Science & Technology

2010-06-01

generalization, rather than statistical generalization. As such, a single case can be used to advance a theory, similarly to how scientific experiments are...ation 411 PNC C ac 2 C PC Not Predicted & Propagated wI Comunication ENot Predicted & Not Propagated w ConPnCcation 04 PPC 5CPredicted & Propagated w...Engineering Management 48(3): 292-306. 5. Clark, J. and Holton, D.A. (2005). A First Look at Graph Theory. World Scientific . 6. Clarkson P.J., Simons, C

Pilot heart rate during in-flight simulated instrument approaches in a general aviation aircraft.

DOT National Transportation Integrated Search

1970-04-01

Eight instrument rated pilots with flying experience ranging from 600 to 12,271 hours each flew 10 simulated ILS instrument approaches in a single engine, general aviation aircraft equipped with a primary flight display arranged in conventional 'T' c...

Compound cycle engine for helicopter application

NASA Technical Reports Server (NTRS)

Castor, Jere; Martin, John; Bradley, Curtiss

1987-01-01

The compound cycle engine (CCE) is a highly turbocharged, power-compounded, ultra-high-power-density, lightweight diesel engine. The turbomachinery is similar to a moderate-pressure-ratio, free-power-turbine gas turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military helicopter applications. Cycle thermodynamic specific fuel consumption (SFC) and engine weight analyses performed to establish general engine operating parameters and configurations are presented. An extensive performance and weight analysis based on a typical 2-hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a contemporary gas turbine engine. The CCE had a 31 percent lower-fuel consumption and resulted in a 16 percent reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb/hp-hr and installed wet weight is 0.43 lb/hp. The major technology development areas required for the CCE are identified and briefly discussed.

Compound cycle engine for helicopter application

NASA Technical Reports Server (NTRS)

Castor, Jere G.

1986-01-01

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded, ultra-high power density, light-weight diesel engine. The turbomachinery is similar to a moderate pressure ratio, free power turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military light helicopter applications. This executive summary presents cycle thermodynamic (SFC) and engine weight analyses performed to establish general engine operating parameters and configuration. An extensive performance and weight analysis based on a typical two hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a T-800 class gas turbine engine. The CCE had a 31% lower-fuel consumption and resulted in a 16% reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb-HP-HR and installed wet weight is 0.43 lbs/HP. The major technology development areas required for the CCE are identified and briefly discussed.

Design of a high-performance rotary stratified-charge research aircraft engine

NASA Technical Reports Server (NTRS)

Jones, C.; Mount, R. E.

1984-01-01

The power section for an advanced rotary stratified-charge general aviation engine has been designed under contract to NASA. The single-rotor research engine of 40 cubic-inches displacement (RCI-40), now being procured for test initiation this summer, is targeted for 320 T.O. horse-power in a two-rotor production engine. The research engine is designed for operating on jet-fuel, gasoline or diesel fuel and will be used to explore applicable advanced technologies and to optimize high output performance variables. Design of major components of the engine is described in this paper.

New Single Piece Blast Hardware design

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

Ulrich, Andri; Steinzig, Michael Louis; Aragon, Daniel Adrian

W, Q and PF engineers and machinists designed and fabricated, on the new Mazak i300, the first Single Piece Blast Hardware (unclassified design shown) reducing fabrication and inspection time by over 50%. The first DU Single Piece is completed and will be used for Hydro Test 3680. Past hydro tests used a twopiece assembly due to a lack of equipment capable of machining the complex saddle shape in a single piece. The i300 provides turning and milling 5-axis machining on one machine. The milling head on the i300 can machine past 90 relative to the spindle axis. This makes itmore » possible to machine the complex saddle surface on a single piece. Going to a single piece eliminates tolerance problems, such as tilting and eccentricity, that typically occurred when assembling the two pieces together« less

Effect of Propeller on Engine Cooling System Drag and Performance

NASA Technical Reports Server (NTRS)

Katz, Joseph; Corsiglia, Victor R.; Barlow, Philip R.

1982-01-01

The pressure recovery of incoming cooling air and the drag associated with engine cooling of a typical general aviation twin-engine aircraft was Investigated experimentally. The semispan model was mounted vertically in the 40 x 80-Foot Wind Tunnel at Ames Research Center. The propeller was driven by an electric motor to provide thrust with low vibration levels for the cold-now configuration. It was found that the propeller slip-stream reduces the frontal air spillage around the blunt nacelle shape. Consequently, this slip-stream effect promotes flow reattachment at the rear section of the engine nacelle and improves inlet pressure recovery. These effects are most pronounced at high angles of attack; that is, climb condition. For the cruise condition those improvements were more moderate.

Programs for skyline planning.

Treesearch

Ward W. Carson

1975-01-01

This paper describes four computer programs for the logging engineer's use in planning log harvesting by skyline systems. One program prepares terrain profile plots from maps mounted on a digitizer; the other programs prepare load-carrying capability and other information for single and multispan standing skylines and single span running skylines. In general, the...

Maximum thrust mode evaluation

NASA Technical Reports Server (NTRS)

Orme, John S.; Nobbs, Steven G.

1995-01-01

Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

Heavy-Duty Low-Temperature and Diesel Combustion & Heavy-Duty Combustion Modeling

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

Musculus, Mark P.

Regulatory drivers and market demands for lower pollutant emissions, lower carbon dioxide emissions, and lower fuel consumption motivate the development of clean and fuel-efficient engine operating strategies. Most current production engines use a combination of both in-cylinder and exhaust emissions-control strategies to achieve these goals. The emissions and efficiency performance of in-cylinder strategies depend strongly on flow and mixing processes associated with fuel injection. Various diesel engine manufacturers have adopted close-coupled post-injection combustion strategies to both reduce pollutant emissions and to increase engine efficiency for heavy-duty applications, as well as for light- and medium-duty applications. Close-coupled post-injections are typically shortmore » injections that follow a larger main injection in the same cycle after a short dwell, such that the energy conversion efficiency of the post-injection is typical of diesel combustion. Of the various post-injection schedules that have been reported in the literature, effects on exhaust soot vary by roughly an order of magnitude in either direction of increasing or decreasing emissions relative to single injections (O’Connor et al., 2015). While several hypotheses have been offered in the literature to help explain these observations, no clear consensus has been established. For new engines to take full advantage of the benefits that post-injections can offer, the in-cylinder mechanisms that affect emissions and efficiency must be identified and described to provide guidance for engine design.« less

Antiparticle cloud temperatures for antihydrogen experiments

NASA Astrophysics Data System (ADS)

Bianconi, A.; Charlton, M.; Lodi Rizzini, E.; Mascagna, V.; Venturelli, L.

2017-07-01

A simple rate-equation description of the heating and cooling of antiparticle clouds under conditions typical of those found in antihydrogen formation experiments is developed and analyzed. We include single-particle collisional, radiative, and cloud expansion effects and, from the modeling calculations, identify typical cooling phenomena and trends and relate these to the underlying physics. Some general rules of thumb of use to experimenters are derived.

Tear Down and Inspection of the Cummins VTA-903 Evaluated Using the Single Common Powertrain Lubricant SCPL

DTIC Science & Technology

2013-12-13

Materials AT Anti-Thrust AVG Average BFV Bradley Fighting Vehicle CAT Caterpillar EOT End Of Test GEP General Engine Products HMMWV High...Vehicle ( BFV ), is a 14.8 liter, V8, turbocharged after-cooled diesel engine, producing approximately 600 hp, and 1225 lb-ft of torque at their respective

Continuum-Kinetic Models and Numerical Methods for Multiphase Applications

NASA Astrophysics Data System (ADS)

Nault, Isaac Michael

This thesis presents a continuum-kinetic approach for modeling general problems in multiphase solid mechanics. In this context, a continuum model refers to any model, typically on the macro-scale, in which continuous state variables are used to capture the most important physics: conservation of mass, momentum, and energy. A kinetic model refers to any model, typically on the meso-scale, which captures the statistical motion and evolution of microscopic entitites. Multiphase phenomena usually involve non-negligible micro or meso-scopic effects at the interfaces between phases. The approach developed in the thesis attempts to combine the computational performance benefits of a continuum model with the physical accuracy of a kinetic model when applied to a multiphase problem. The approach is applied to modeling a single particle impact in Cold Spray, an engineering process that intimately involves the interaction of crystal grains with high-magnitude elastic waves. Such a situation could be classified a multiphase application due to the discrete nature of grains on the spatial scale of the problem. For this application, a hyper elasto-plastic model is solved by a finite volume method with approximate Riemann solver. The results of this model are compared for two types of plastic closure: a phenomenological macro-scale constitutive law, and a physics-based meso-scale Crystal Plasticity model.

Zombie algorithms: a timesaving remote sensing systems engineering tool

NASA Astrophysics Data System (ADS)

Ardanuy, Philip E.; Powell, Dylan C.; Marley, Stephen

2008-08-01

In modern horror fiction, zombies are generally undead corpses brought back from the dead by supernatural or scientific means, and are rarely under anyone's direct control. They typically have very limited intelligence, and hunger for the flesh of the living [1]. Typical spectroradiometric or hyperspectral instruments providess calibrated radiances for a number of remote sensing algorithms. The algorithms typically must meet specified latency and availability requirements while yielding products at the required quality. These systems, whether research, operational, or a hybrid, are typically cost constrained. Complexity of the algorithms can be high, and may evolve and mature over time as sensor characterization changes, product validation occurs, and areas of scientific basis improvement are identified and completed. This suggests the need for a systems engineering process for algorithm maintenance that is agile, cost efficient, repeatable, and predictable. Experience on remote sensing science data systems suggests the benefits of "plug-n-play" concepts of operation. The concept, while intuitively simple, can be challenging to implement in practice. The use of zombie algorithms-empty shells that outwardly resemble the form, fit, and function of a "complete" algorithm without the implemented theoretical basis-provides the ground systems advantages equivalent to those obtained by integrating sensor engineering models onto the spacecraft bus. Combined with a mature, repeatable process for incorporating the theoretical basis, or scientific core, into the "head" of the zombie algorithm, along with associated scripting and registration, provides an easy "on ramp" for the rapid and low-risk integration of scientific applications into operational systems.

All-optical differential equation solver with constant-coefficient tunable based on a single microring resonator.

PubMed

Yang, Ting; Dong, Jianji; Lu, Liangjun; Zhou, Linjie; Zheng, Aoling; Zhang, Xinliang; Chen, Jianping

2014-07-04

Photonic integrated circuits for photonic computing open up the possibility for the realization of ultrahigh-speed and ultra wide-band signal processing with compact size and low power consumption. Differential equations model and govern fundamental physical phenomena and engineering systems in virtually any field of science and engineering, such as temperature diffusion processes, physical problems of motion subject to acceleration inputs and frictional forces, and the response of different resistor-capacitor circuits, etc. In this study, we experimentally demonstrate a feasible integrated scheme to solve first-order linear ordinary differential equation with constant-coefficient tunable based on a single silicon microring resonator. Besides, we analyze the impact of the chirp and pulse-width of input signals on the computing deviation. This device can be compatible with the electronic technology (typically complementary metal-oxide semiconductor technology), which may motivate the development of integrated photonic circuits for optical computing.

All-optical differential equation solver with constant-coefficient tunable based on a single microring resonator

PubMed Central

Yang, Ting; Dong, Jianji; Lu, Liangjun; Zhou, Linjie; Zheng, Aoling; Zhang, Xinliang; Chen, Jianping

2014-01-01

Photonic integrated circuits for photonic computing open up the possibility for the realization of ultrahigh-speed and ultra wide-band signal processing with compact size and low power consumption. Differential equations model and govern fundamental physical phenomena and engineering systems in virtually any field of science and engineering, such as temperature diffusion processes, physical problems of motion subject to acceleration inputs and frictional forces, and the response of different resistor-capacitor circuits, etc. In this study, we experimentally demonstrate a feasible integrated scheme to solve first-order linear ordinary differential equation with constant-coefficient tunable based on a single silicon microring resonator. Besides, we analyze the impact of the chirp and pulse-width of input signals on the computing deviation. This device can be compatible with the electronic technology (typically complementary metal-oxide semiconductor technology), which may motivate the development of integrated photonic circuits for optical computing. PMID:24993440

Single Phase Passive Rectification Versus Active Rectification Applied to High Power Stirling Engines

NASA Technical Reports Server (NTRS)

Santiago, Walter; Birchenough, Arthur G.

2006-01-01

Stirling engine converters are being considered as potential candidates for high power energy conversion systems required by future NASA explorations missions. These types of engines typically contain two major moving parts, the displacer and the piston, in which a linear alternator is attached to the piston to produce a single phase sinusoidal waveform at a specific electric frequency. Since all Stirling engines perform at low electrical frequencies (less or equal to 100 Hz), space explorations missions that will employ these engines will be required to use DC power management and distribution (PMAD) system instead of an AC PMAD system to save on space and weight. Therefore, to supply such DC power an AC to DC converter is connected to the Stirling engine. There are two types of AC to DC converters that can be employed, a passive full bridge diode rectifier and an active switching full bridge rectifier. Due to the inherent line inductance of the Stirling Engine-Linear Alternator (SE-LA), their sinusoidal voltage and current will be phase shifted producing a power factor below 1. In order to keep power the factor close to unity, both AC to DC converters topologies will implement power factor correction. This paper discusses these power factor correction methods as well as their impact on overall mass for exploration applications. Simulation results on both AC to DC converters topologies with power factor correction as a function of output power and SE-LA line inductance impedance are presented and compared.

Heat transfer in rocket engine combustion chambers and regeneratively cooled nozzles

NASA Technical Reports Server (NTRS)

1993-01-01

A conjugate heat transfer computational fluid dynamics (CFD) model to describe regenerative cooling in the main combustion chamber and nozzle and in the injector faceplate region for a launch vehicle class liquid rocket engine was developed. An injector model for sprays which treats the fluid as a variable density, single-phase media was formulated, incorporated into a version of the FDNS code, and used to simulate the injector flow typical of that in the Space Shuttle Main Engine (SSME). Various chamber related heat transfer analyses were made to verify the predictive capability of the conjugate heat transfer analysis provided by the FDNS code. The density based version of the FDNS code with the real fluid property models developed was successful in predicting the streamtube combustion of individual injector elements.

Best management practices for soft engineering of shoreline

USGS Publications Warehouse

Caulk, Andrew D.; Gannon, John E.; Shaw, John R.; Hartig, John H.

2000-01-01

Historically, many river shorelines were stabilized and hardened with concrete and steel to protect developments from flooding and erosion, or to accommodate commercial navigation or industry. Typically shorelines were developed for a single purpose. Today, there is growing interest in developing shorelines for multiple purposes so that additional benefits can be accrued. Soft engineering is the use of ecological principles and practices to reduce erosion and achieve the stabilization and safety of shorelines, while enhancing habitat, improving aesthetics, and saving money. The purpose of this best management practices manual is to provide insights and technical advice to local governments, developers, planners, consultants, and industries on when, where, why, and how to incorporate soft engineering of shorelines into shoreline redevelopment projects and reap subsequent benefits. More specific technical advice and contact information can be found in the soft engineering case studies presented in this manual.

Baseline performance of the GPU 3 Stirling engine

NASA Technical Reports Server (NTRS)

Thieme, L. G.; Tew, R. C., Jr.

1978-01-01

A 10 horsepower single-cylinder rhombic-drive Stirling engine was converted to a research configuration to obtain data for validation of Stirling computer simulations. The engine was originally built by General Motors Research Laboratories for the U.S. Army in 1965 as part of a 3 kW engine-generator set, designated the GHU 3 (Ground Power Unit). This report presents test results for a range of heater gas temperatures, mean compression-space pressures, and engine speeds with both helium and hydrogen as the working fluids. Also shown are initial data comparisons with computer simulation predictions.

Dissecting single-molecule signal transduction in carbon nanotube circuits with protein engineering

PubMed Central

Choi, Yongki; Olsen, Tivoli J.; Sims, Patrick C.; Moody, Issa S.; Corso, Brad L.; Dang, Mytrang N.; Weiss, Gregory A.; Collins, Philip G.

2013-01-01

Single molecule experimental methods have provided new insights into biomolecular function, dynamic disorder, and transient states that are all invisible to conventional measurements. A novel, non-fluorescent single molecule technique involves attaching single molecules to single-walled carbon nanotube field-effective transistors (SWNT FETs). These ultrasensitive electronic devices provide long-duration, label-free monitoring of biomolecules and their dynamic motions. However, generalization of the SWNT FET technique first requires design rules that can predict the success and applicability of these devices. Here, we report on the transduction mechanism linking enzymatic processivity to electrical signal generation by a SWNT FET. The interaction between SWNT FETs and the enzyme lysozyme was systematically dissected using eight different lysozyme variants synthesized by protein engineering. The data prove that effective signal generation can be accomplished using a single charged amino acid, when appropriately located, providing a foundation to widely apply SWNT FET sensitivity to other biomolecular systems. PMID:23323846

General algebraic method applied to control analysis of complex engine types

NASA Technical Reports Server (NTRS)

Boksenbom, Aaron S; Hood, Richard

1950-01-01

A general algebraic method of attack on the problem of controlling gas-turbine engines having any number of independent variables was utilized employing operational functions to describe the assumed linear characteristics for the engine, the control, and the other units in the system. Matrices were used to describe the various units of the system, to form a combined system showing all effects, and to form a single condensed matrix showing the principal effects. This method directly led to the conditions on the control system for noninteraction so that any setting disturbance would affect only its corresponding controlled variable. The response-action characteristics were expressed in terms of the control system and the engine characteristics. The ideal control-system characteristics were explicitly determined in terms of any desired response action.

Cooling Air Inlet and Exit Geometries on Aircraft Engine Installations

NASA Technical Reports Server (NTRS)

Katz, Joseph; Corsiglia, Victor R.; Barlow, Philip R.

1982-01-01

A semispan wing and nacelle of a typical general aviation twin-engine aircraft was tested to evaluate the cooling capability and drag or several nacelle shapes; the nacelle shapes included cooling air inlet and exit variations. The tests were conducted in the Ames Research Center 40 x 80-ft Wind Tunnel. It was found that the cooling air inlet geometry of opposed piston engine installations has a major effect on inlet pressure recovery, but only a minor effect on drag. Exit location showed large effect on drag, especially for those locations on the sides of the nacelle where the suction characteristics were based on interaction with the wing surface pressures.

Experiments with a Supersonic Multi-Channel Radial Diffuser.

DTIC Science & Technology

1980-09-01

unlimited. 17 . DISTRIBUTION STATEMENT (o the *bsta~c entered nRItok 20, it dffttt Iton, Report) IS. SUPPLEMENTARY NOTES 19. KEY WORDS (Continue o...Improvements 17 VI SIGNIFICANT TEST RESULTS 20 1. General Considerations 20 2. Typical Radial Diffuser Performance 20 3. Flow Stability Experiments 22 VIII...Adjustments Indicated 39 16 Comparison of the Single Channel Performances for Two Extreme Channel Geometries 40 17 Typical Radial Diffuser Performance

The Landscape of Somatic Chromosomal Copy Number Aberrations in GEM Models of Prostate Carcinoma

PubMed Central

Bianchi-Frias, Daniella; Hernandez, Susana A.; Coleman, Roger; Wu, Hong; Nelson, Peter S.

2015-01-01

Human prostate cancer (PCa) is known to harbor recurrent genomic aberrations consisting of chromosomal losses, gains, rearrangements and mutations that involve oncogenes and tumor suppressors. Genetically engineered mouse (GEM) models have been constructed to assess the causal role of these putative oncogenic events and provide molecular insight into disease pathogenesis. While GEM models generally initiate neoplasia by manipulating a single gene, expression profiles of GEM tumors typically comprise hundreds of transcript alterations. It is unclear whether these transcriptional changes represent the pleiotropic effects of single oncogenes, and/or cooperating genomic or epigenomic events. Therefore, it was determined if structural chromosomal alterations occur in GEM models of PCa and whether the changes are concordant with human carcinomas. Whole genome array-based comparative genomic hybridization (CGH) was used to identify somatic chromosomal copy number aberrations (SCNAs) in the widely used TRAMP, Hi-Myc, Pten-null and LADY GEM models. Interestingly, very few SCNAs were identified and the genomic architecture of Hi-Myc, Pten-null and LADY tumors were essentially identical to the germline. TRAMP neuroendocrine carcinomas contained SCNAs, which comprised three recurrent aberrations including a single copy loss of chromosome 19 (encoding Pten). In contrast, cell lines derived from the TRAMP, Hi-Myc, and Pten-null tumors were notable for numerous SCNAs that included copy gains of chromosome 15 (encoding Myc) and losses of chromosome 11 (encoding p53). PMID:25298407

Homogenized modeling methodology for 18650 lithium-ion battery module under large deformation

PubMed Central

Tang, Liang; Cheng, Pengle

2017-01-01

Effective lithium-ion battery module modeling has become a bottleneck for full-size electric vehicle crash safety numerical simulation. Modeling every single cell in detail would be costly. However, computational accuracy could be lost if the module is modeled by using a simple bulk material or rigid body. To solve this critical engineering problem, a general method to establish a computational homogenized model for the cylindrical battery module is proposed. A single battery cell model is developed and validated through radial compression and bending experiments. To analyze the homogenized mechanical properties of the module, a representative unit cell (RUC) is extracted with the periodic boundary condition applied on it. An elastic–plastic constitutive model is established to describe the computational homogenized model for the module. Two typical packing modes, i.e., cubic dense packing and hexagonal packing for the homogenized equivalent battery module (EBM) model, are targeted for validation compression tests, as well as the models with detailed single cell description. Further, the homogenized EBM model is confirmed to agree reasonably well with the detailed battery module (DBM) model for different packing modes with a length scale of up to 15 × 15 cells and 12% deformation where the short circuit takes place. The suggested homogenized model for battery module makes way for battery module and pack safety evaluation for full-size electric vehicle crashworthiness analysis. PMID:28746390

Homogenized modeling methodology for 18650 lithium-ion battery module under large deformation.

PubMed

Tang, Liang; Zhang, Jinjie; Cheng, Pengle

2017-01-01

Effective lithium-ion battery module modeling has become a bottleneck for full-size electric vehicle crash safety numerical simulation. Modeling every single cell in detail would be costly. However, computational accuracy could be lost if the module is modeled by using a simple bulk material or rigid body. To solve this critical engineering problem, a general method to establish a computational homogenized model for the cylindrical battery module is proposed. A single battery cell model is developed and validated through radial compression and bending experiments. To analyze the homogenized mechanical properties of the module, a representative unit cell (RUC) is extracted with the periodic boundary condition applied on it. An elastic-plastic constitutive model is established to describe the computational homogenized model for the module. Two typical packing modes, i.e., cubic dense packing and hexagonal packing for the homogenized equivalent battery module (EBM) model, are targeted for validation compression tests, as well as the models with detailed single cell description. Further, the homogenized EBM model is confirmed to agree reasonably well with the detailed battery module (DBM) model for different packing modes with a length scale of up to 15 × 15 cells and 12% deformation where the short circuit takes place. The suggested homogenized model for battery module makes way for battery module and pack safety evaluation for full-size electric vehicle crashworthiness analysis.

V/STOL propulsion control analysis: Phase 2, task 5-9

NASA Technical Reports Server (NTRS)

1981-01-01

Typical V/STOL propulsion control requirements were derived for transition between vertical and horizontal flight using the General Electric RALS (Remote Augmented Lift System) concept. Steady-state operating requirements were defined for a typical Vertical-to-Horizontal transition and for a typical Horizontal-to-Vertical transition. Control mode requirements were established and multi-variable regulators developed for individual operating conditions. Proportional/Integral gain schedules were developed and were incorporated into a transition controller with capabilities for mode switching and manipulated variable reassignment. A non-linear component-level transient model of the engine was developed and utilized to provide a preliminary check-out of the controller logic. An inlet and nozzle effects model was developed for subsequent incorporation into the engine model and an aircraft model was developed for preliminary flight transition simulations. A condition monitoring development plan was developed and preliminary design requirements established. The Phase 1 long-range technology plan was refined and restructured toward the development of a real-time high fidelity transient model of a supersonic V/STOL propulsion system and controller for use in a piloted simulation program at NASA-Ames.

A method for determining optimum phasing of a multiphase propulsion system for a single-stage vehicle with linearized inert weight

NASA Technical Reports Server (NTRS)

Martin, J. A.

1974-01-01

A general analytical treatment is presented of a single-stage vehicle with multiple propulsion phases. A closed-form solution for the cost and for the performance and a derivation of the optimal phasing of the propulsion are included. Linearized variations in the inert weight elements are included, and the function to be minimized can be selected. The derivation of optimal phasing results in a set of nonlinear algebraic equations for optimal fuel volumes, for which a solution method is outlined. Three specific example cases are analyzed: minimum gross lift-off weight, minimum inert weight, and a minimized general function for a two-phase vehicle. The results for the two-phase vehicle are applied to the dual-fuel rocket. Comparisons with single-fuel vehicles indicate that dual-fuel vehicles can have lower inert weight either by development of a dual-fuel engine or by parallel burning of separate engines from lift-off.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer

NASA Astrophysics Data System (ADS)

Marciniak, L.; Prorok, K.; Francés-Soriano, L.; Pérez-Prieto, J.; Bednarkiewicz, A.

2016-02-01

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale. Electronic supplementary information (ESI) available: Characterization, structural and morphological characterization of nanocrystals, the measurement setup. See DOI: 10.1039/c5nr08223d

Automotive Stirling engine: Mod 2 design report

NASA Technical Reports Server (NTRS)

Nightingale, Noel P.

1986-01-01

The design of an automotive Stirling engine that achieves the superior fuel economy potential of the Stirling cycle is described. As the culmination of a 9-yr development program, this engine, designated the Mod 2, also nullifies arguments that Stirling engines are heavy, expensive, unreliable, demonstrating poor performance. Installed in a General Motors Chevrolet Celebrity car, this engine has a predicted combined fuel economy on unleaded gasoline of 17.5 km/l (41 mpg)- a value 50% above the current vehicle fleet average. The Mod 2 Stirling engine is a four-cylinder V-drive design with a single crankshaft. The engine is also equipped with all the controls and auxiliaries necessary for automotive operation.

General Electric I-40 Engine at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1946-08-21

A mechanic works on a General Electric I-40 turbojet at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The military selected General Electric’s West Lynn facility in 1941 to secretly replicate the centrifugal turbojet engine designed by British engineer Frank Whittle. General Electric’s first attempt, the I-A, was fraught with problems. The design was improved somewhat with the subsequent I-16 engine. It was not until the engine's next reincarnation as the I-40 in 1943 that General Electric’s efforts paid off. The 4000-pound thrust I-40 was incorporated into the Lockheed Shooting Star airframe and successfully flown in June 1944. The Shooting Star became the US’s first successful jet aircraft and the first US aircraft to reach 500 miles per hour. The NACA’s Lewis Flight Propulsion Laboratory studied all of General Electric’s centrifugal turbojets both during World War II and afterwards. The entire Shooting Star aircraft was investigated in the Altitude Wind Tunnel during 1945. The researchers studied the engine compressor performance, thrust augmentation using a water injection, and compared different fuel blends in a single combustor. The mechanic in this photograph is inserting a combustion liner into one of the 14 combustor cans. The compressor, which is not yet installed in this photograph, pushed high pressure air into these combustors. There the air mixed with the fuel and was heated. The hot air was then forced through a rotating turbine that powered the engine before being expelled out the nozzle to produce thrust.

Causes and risk factors for fatal accidents in non-commercial twin engine piston general aviation aircraft.

PubMed

Boyd, Douglas D

2015-04-01

Accidents in twin-engine aircraft carry a higher risk of fatality compared with single engine aircraft and constitute 9% of all general aviation accidents. The different flight profile (higher airspeed, service ceiling, increased fuel load, and aircraft yaw in engine failure) may make comparable studies on single-engine aircraft accident causes less relevant. The objective of this study was to identify the accident causes for non-commercial operations in twin engine aircraft. A NTSB accident database query for accidents in twin piston engine airplanes of 4-8 seat capacity with a maximum certified weight of 3000-8000lbs. operating under 14CFR Part 91 for the period spanning 2002 and 2012 returned 376 accidents. Accident causes and contributing factors were as per the NTSB final report categories. Total annual flight hour data for the twin engine piston aircraft fleet were obtained from the FAA. Statistical analyses employed Chi Square, Fisher's Exact and logistic regression analysis. Neither the combined fatal/non-fatal accident nor the fatal accident rate declined over the period spanning 2002-2012. Under visual weather conditions, the largest number, n=27, (27%) of fatal accidents was attributed to malfunction with a failure to follow single engine procedures representing the most common contributing factor. In degraded visibility, poor instrument approach procedures resulted in the greatest proportion of fatal crashes. Encountering thunderstorms was the most lethal of all accident causes with all occupants sustaining fatal injuries. At night, a failure to maintain obstacle/terrain clearance was the most common accident cause leading to 36% of fatal crashes. The results of logistic regression showed that operations at night (OR 3.7), off airport landings (OR 14.8) and post-impact fire (OR 7.2) all carried an excess risk of a fatal flight. This study indicates training areas that should receive increased emphasis for twin-engine training/recency. First, increased training should be provided on single engine procedures in the event of an engine failure. Second, more focus should be placed on instrument approaches and recovery from unusual aircraft attitude where visibility is degraded. Third, pilots should be made aware of appropriate speed selection for inadvertent flights in convective weather. Finally, emphasizing the importance of conducting night operations under instrument flight rules with its altitude restrictions should lead to a diminished proportion of accidents attributed to failure to maintain obstacle/terrain clearance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ecosystem engineering varies spatially: a test of the vegetation modification paradigm for prairie dogs

USGS Publications Warehouse

Baker, Bruce W.; Augustine, David J.; Sedgwick, James A.; Lubow, Bruce C.

2013-01-01

Colonial, burrowing herbivores can be engineers of grassland and shrubland ecosystems worldwide. Spatial variation in landscapes suggests caution when extrapolating single-place studies of single species, but lack of data and the need to generalize often leads to ‘model system’ thinking and application of results beyond appropriate statistical inference. Generalizations about the engineering effects of prairie dogs (Cynomys sp.) developed largely from intensive study at a single complex of black-tailed prairie dogs C. ludovicianus in northern mixed prairie, but have been extrapolated to other ecoregions and prairie dog species in North America, and other colonial, burrowing herbivores. We tested the paradigm that prairie dogs decrease vegetation volume and the cover of grasses and tall shrubs, and increase bare ground and forb cover. We sampled vegetation on and off 279 colonies at 13 complexes of 3 prairie dog species widely distributed across 5 ecoregions in North America. The paradigm was generally supported at 7 black-tailed prairie dog complexes in northern mixed prairie, where vegetation volume, grass cover, and tall shrub cover were lower, and bare ground and forb cover were higher, on colonies than at paired off-colony sites. Outside the northern mixed prairie, all 3 prairie dog species consistently reduced vegetation volume, but their effects on cover of plant functional groups varied with prairie dog species and the grazing tolerance of dominant perennial grasses. White-tailed prairie dogs C. leucurus in sagebrush steppe did not reduce shrub cover, whereas black-tailed prairie dogs suppressed shrub cover at all complexes with tall shrubs in the surrounding habitat matrix. Black-tailed prairie dogs in shortgrass steppe and Gunnison's prairie dogs C. gunnisoni in Colorado Plateau grassland both had relatively minor effects on grass cover, which may reflect the dominance of grazing-tolerant shortgrasses at both complexes. Variation in modification of vegetation structure may be understood in terms of the responses of different dominant perennial grasses to intense defoliation and differences in foraging behavior among prairie dog species. Spatial variation in the engineering role of prairie dogs suggests spatial variation in their keystone role, and spatial variation in the roles of other ecosystem engineers. Thus, ecosystem engineering can have a spatial component not evident from single-place studies.

The Statistics of wood assays for preservative retention

Treesearch

Patricia K. Lebow; Scott W. Conklin

2011-01-01

This paper covers general statistical concepts that apply to interpreting wood assay retention values. In particular, since wood assays are typically obtained from a single composited sample, the statistical aspects, including advantages and disadvantages, of simple compositing are covered.

Low-cost single-crystal turbine blades, volume 2

NASA Technical Reports Server (NTRS)

Strangman, T. E.; Dennis, R. E.; Heath, B. R.

1984-01-01

The overall objectives of Project 3 were to develop the exothermic casting process to produce uncooled single-crystal (SC) HP turbine blades in MAR-M 247 and higher strength derivative alloys and to validate the materials process and components through extensive mechanical property testing, rig testing, and 200 hours of endurance engine testing. These Program objectives were achieved. The exothermic casting process was successfully developed into a low-cost nonproperietary method for producing single-crystal castings. Single-crystal MAR-M 247 and two derivatives DS alloys developed during this project, NASAIR 100 and SC Alloy 3, were fully characterized through mechanical property testing. SC MAR-M 247 shows no significant improvement in strength over directionally solidified (DS) MAR-M 247, but the derivative alloys, NASAIR 100 and Alloy 3, show significant tensile and fatigue improvements. Firtree testing, holography, and strain-gauge rig testing were used to determine the effects of the anisotropic characteristics of single-crystal materials. No undesirable characteristics were found. In general, the single-crystal material behaved similarly to DS MAR-M 247. Two complete engine sets of SC HP turbine blades were cast using the exothermic casting process and fully machined. These blades were successfully engine-tested.

Non-Hermitian engineering of single mode two dimensional laser arrays

PubMed Central

Teimourpour, Mohammad H.; Ge, Li; Christodoulides, Demetrios N.; El-Ganainy, Ramy

2016-01-01

A new scheme for building two dimensional laser arrays that operate in the single supermode regime is proposed. This is done by introducing an optical coupling between the laser array and lossy pseudo-isospectral chains of photonic resonators. The spectrum of this discrete reservoir is tailored to suppress all the supermodes of the main array except the fundamental one. This spectral engineering is facilitated by employing the Householder transformation in conjunction with discrete supersymmetry. The proposed scheme is general and can in principle be used in different platforms such as VCSEL arrays and photonic crystal laser arrays. PMID:27698355

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

NASA Technical Reports Server (NTRS)

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

1982-01-01

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

158. ARAIII Reactor building (ARA608) Secondary cooling loop and piping ...

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

158. ARA-III Reactor building (ARA-608) Secondary cooling loop and piping plan. This drawing was selected as a typical example of piping arrangements within reactor building. Aerojet/general 880-area/GCRE-608-P-16. Date: February 1958. INeel index code no. 063-0608-50-013-102641. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Characteristics, Similarities, and Differences among Four-Year Cooperative Engineering Programs in the United States

ERIC Educational Resources Information Center

Egbert, Robert I.; Stone, Lorene H.; Adams, David L.

2011-01-01

Four-year cooperative engineering programs are becoming more common in the United States. Cooperative engineering programs typically involve a "parent" institution with an established engineering program and one or more "satellite" institutions which typically have few or no engineering programs and are located in an area where…

Color mixing from monolithically integrated InGaN-based light-emitting diodes by local strain engineering

NASA Astrophysics Data System (ADS)

Chung, Kunook; Sui, Jingyang; Demory, Brandon; Ku, Pei-Cheng

2017-07-01

Additive color mixing across the visible spectrum was demonstrated from an InGaN based light-emitting diode (LED) pixel comprising red, green, and blue subpixels monolithically integrated and enabled by local strain engineering. The device was fabricated using a top-down approach on a metal-organic chemical vapor deposition-grown sample consisting of a typical LED epitaxial stack. The three color subpixels were defined in a single lithographic step. The device was characterized for its electrical properties and emission spectra under an uncooled condition, which is desirable in practical applications. The color mixing was controlled by pulse-width modulation, and the degree of color control was also characterized.

The spatial dynamics of ecosystem engineers.

PubMed

Franco, Caroline; Fontanari, José F

2017-10-01

The changes on abiotic features of ecosystems have rarely been taken into account by population dynamics models, which typically focus on trophic and competitive interactions between species. However, understanding the population dynamics of organisms that must modify their habitats in order to survive, the so-called ecosystem engineers, requires the explicit incorporation of abiotic interactions in the models. Here we study a model of ecosystem engineers that is discrete both in space and time, and where the engineers and their habitats are arranged in patches fixed to the sites of regular lattices. The growth of the engineer population is modeled by Ricker equation with a density-dependent carrying capacity that is given by the number of modified habitats. A diffusive dispersal stage ensures that a fraction of the engineers move from their birth patches to neighboring patches. We find that dispersal influences the metapopulation dynamics only in the case that the local or single-patch dynamics exhibit chaotic behavior. In that case, it can suppress the chaotic behavior and avoid extinctions in the regime of large intrinsic growth rate of the population. Copyright © 2017 Elsevier Inc. All rights reserved.

A Comparison of Propulsion Concepts for SSTO Reusable Launchers

NASA Astrophysics Data System (ADS)

Varvill, R.; Bond, A.

This paper discusses the relevant selection criteria for a single stage to orbit (SSTO) propulsion system and then reviews the characteristics of the typical engine types proposed for this role against these criteria. The engine types considered include Hydrogen/Oxygen (H2/O2) rockets, Scramjets, Turbojets, Turborockets and Liquid Air Cycle Engines. In the authors opinion none of the above engines are able to meet all the necessary criteria for an SSTO propulsion system simultaneously. However by selecting appropriate features from each it is possible to synthesise a new class of engines which are specifically optimised for the SSTO role. The resulting engines employ precooling of the airstream and a high internal pressure ratio to enable a relatively conventional high pressure rocket combustion chamber to be utilised in both airbreathing and rocket modes. This results in a significant mass saving with installation advantages which by careful design of the cycle thermodynamics enables the full potential of airbreathing to be realised. The SABRE engine which powers the SKYLON launch vehicle is an example of one of these so called `Precooled hybrid airbreathing rocket engines' and the concep- tual reasoning which leads to its main design parameters are described in the paper.

A Robust Damage Reporting Strategy for Polymeric Materials Enabled by Aggregation Induced Emission

DTIC Science & Technology

2016-08-17

and Technology, ‡Department of Chemistry, ∥Department of Materials Science and Engineering, ⊥Department of Mechanical Science and Engineering, and...enabled by aggregation-induced emission (AIE). This simple, yet powerful system relies on a single active component, and the general mechanism ...delivers outstanding performance in a wide variety of materials with diverse chemical and mechanical properties. Small (micrometer) scale damage in

Deicing System Protects General Aviation Aircraft

NASA Technical Reports Server (NTRS)

2007-01-01

Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts

A Collaborative Analysis Tool for Integrating Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

NASA Technical Reports Server (NTRS)

Stanley, Thomas Troy; Alexander, Reginald

1999-01-01

Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. The deficiencies in the scramjet powered concept led to a revival of interest in Rocket-Based Combined-Cycle (RBCC) propulsion systems. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. At this point the transitions to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scram4jet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance.

Light-based science and technologies and human civilization: an optical course for general education

NASA Astrophysics Data System (ADS)

Li, Xiaotong; Wang, Kaiwei; Yang, Qing; Si, Ke

2017-08-01

Starting from 2015, a general education course named "Light-based science and technologies and human civilization" has been offered in Zhejiang University. We try to give a humanism view angle to observe optics and optical engineering, and combine them with the relationship of human and the nature, the development of human society and human health. In this course we introduce different historical periods of light-based science and technologies, the great optical researchers, the typical research methods, advantages, academic discussions and the relationship with human civilization. The relevant cross-fields of learning and Nobel Prize winners are also included. This course provides the students with the typical examples about how academic revolution influences the world development, and also with humanism sight which exceeds the range of science and technologies themselves.

Engine Lathe Operator. Instructor's Guide. Part of Single-Tool Skills Program Series. Machine Industries Occupations.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

Expected to help meet the need for trained operators in metalworking and suitable for use in the adult education programs of school districts, in manpower development and training programs, and in secondary schools, this guide consists of four sections: Introduction, General Job Content, Shop Projects, and Drawings for the Projects. General Job…

Gendered Perceptions of Typical Engineers across Specialties for Engineering Majors

ERIC Educational Resources Information Center

Kelley, Margaret S.; Bryan, Kimberley K.

2018-01-01

Young women do not choose to be engineers nearly as often as young men, and they tend to cluster in particular specialties when they do. We examine these patterns and the role of gender schemas as applied to perceptions of typical engineers in understanding the choices that women make in terms of engineering specialties. We use Part 1 of two waves…

SAM Theory Manual

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

Hu, Rui

The System Analysis Module (SAM) is an advanced and modern system analysis tool being developed at Argonne National Laboratory under the U.S. DOE Office of Nuclear Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM development aims for advances in physical modeling, numerical methods, and software engineering to enhance its user experience and usability for reactor transient analyses. To facilitate the code development, SAM utilizes an object-oriented application framework (MOOSE), and its underlying meshing and finite-element library (libMesh) and linear and non-linear solvers (PETSc), to leverage modern advanced software environments and numerical methods. SAM focuses on modeling advanced reactormore » concepts such as SFRs (sodium fast reactors), LFRs (lead-cooled fast reactors), and FHRs (fluoride-salt-cooled high temperature reactors) or MSRs (molten salt reactors). These advanced concepts are distinguished from light-water reactors in their use of single-phase, low-pressure, high-temperature, and low Prandtl number (sodium and lead) coolants. As a new code development, the initial effort has been focused on modeling and simulation capabilities of heat transfer and single-phase fluid dynamics responses in Sodium-cooled Fast Reactor (SFR) systems. The system-level simulation capabilities of fluid flow and heat transfer in general engineering systems and typical SFRs have been verified and validated. This document provides the theoretical and technical basis of the code to help users understand the underlying physical models (such as governing equations, closure models, and component models), system modeling approaches, numerical discretization and solution methods, and the overall capabilities in SAM. As the code is still under ongoing development, this SAM Theory Manual will be updated periodically to keep it consistent with the state of the development.« less

Prediction of the effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes with flaps retracted

NASA Technical Reports Server (NTRS)

Weil, Joseph; Sleeman, William C , Jr

1949-01-01

The effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes are analyzed, and a simple method is presented for computing power-on pitching-moment curves for flap-retracted flight conditions. The methods evolved are based on the results of powered-model wind-tunnel investigations of 28 model configurations. Correlation curves are presented from which the effects of power on the downwash over the tail and the stabilizer effectiveness can be rapidly predicted. The procedures developed enable prediction of power-on longitudinal stability characteristics that are generally in very good agreement with experiment.

Design study of technology requirements for high performance single-propeller-driven business airplanes

NASA Technical Reports Server (NTRS)

Kohlman, D. L.; Hammer, J.

1985-01-01

Developments in aerodyamic, structural and propulsion technologies which influence the potential for significant improvements in performance and fuel efficiency of general aviation business airplanes are discussed. The advancements include such technolgies as natural laminar flow, composite materials, and advanced intermittent combustion engines. The design goal for this parameter design study is a range of 1300 nm at 300 knots true airspeed with a payload of 1200lbs at 35,000 ft cruise altitude. The individual and synergistic effects of various advanced technologies on the optimization of this class of high performance, single engine, propeller driven business airplanes are identified.

The Engineering Technician.

ERIC Educational Resources Information Center

American Society for Engineering Education, Washington, DC.

Occupational and educational information concerning 12 categories of engineering technicians and engineering technology is presented. This information covers the role of the technicians, student qualifications, typical job titles, and typical educational programs. The categories presented are (1) air conditioning, heating, and refrigeration, (2)…

Federal Aviation Regulations - National Aviation Regulations of Russia

NASA Astrophysics Data System (ADS)

Chernykh, O.; Bakiiev, M.

2018-03-01

Chinese Aerospace Engineering is currently developing cooperation with Russia on a wide-body airplane project that has directed the work towards better understanding of Russian airworthiness management system. The paper introduces national Aviation regulations of Russia, presents a comparison of them with worldwide recognized regulations, and highlights typical differences. They have been found to be: two general types of regulations used in Russia (Aviation Regulations and Federal Aviation Regulations), non-unified structure of regulations on Aircraft Operation management, various separate agencies responsible for regulation issuance instead of one national aviation authority, typical confusions in references. The paper also gives a list of effective Russian Regulations of both types.

Effect of timed secondary-air injection on automotive emissions

NASA Technical Reports Server (NTRS)

Coffin, K. P.

1973-01-01

A single cylinder of an automotive V-8 engine was fitted with an electronically timed system for the pulsed injection of secondary air. A straight-tube exhaust minimized any mixing other than that produced by secondary-air pulsing. The device was operated over a range of engine loads and speeds. Effects attributable to secondary-air pulsing were found, but emission levels were generally no better than using the engine's own injection system. Under nontypical fast-idle, no-load conditions, emission levels were reduced by roughly a factor of 2.

Taxonomy-aware feature engineering for microbiome classification.

PubMed

Oudah, Mai; Henschel, Andreas

2018-06-15

What is a healthy microbiome? The pursuit of this and many related questions, especially in light of the recently recognized microbial component in a wide range of diseases has sparked a surge in metagenomic studies. They are often not simply attributable to a single pathogen but rather are the result of complex ecological processes. Relatedly, the increasing DNA sequencing depth and number of samples in metagenomic case-control studies enabled the applicability of powerful statistical methods, e.g. Machine Learning approaches. For the latter, the feature space is typically shaped by the relative abundances of operational taxonomic units, as determined by cost-effective phylogenetic marker gene profiles. While a substantial body of microbiome/microbiota research involves unsupervised and supervised Machine Learning, very little attention has been put on feature selection and engineering. We here propose the first algorithm to exploit phylogenetic hierarchy (i.e. an all-encompassing taxonomy) in feature engineering for microbiota classification. The rationale is to exploit the often mono- or oligophyletic distribution of relevant (but hidden) traits by virtue of taxonomic abstraction. The algorithm is embedded in a comprehensive microbiota classification pipeline, which we applied to a diverse range of datasets, distinguishing healthy from diseased microbiota samples. We demonstrate substantial improvements over the state-of-the-art microbiota classification tools in terms of classification accuracy, regardless of the actual Machine Learning technique while using drastically reduced feature spaces. Moreover, generalized features bear great explanatory value: they provide a concise description of conditions and thus help to provide pathophysiological insights. Indeed, the automatically and reproducibly derived features are consistent with previously published domain expert analyses.

Design and analysis of a fuel-efficient single-engine, turboprop-powered, business airplane

NASA Technical Reports Server (NTRS)

Martin, G. L.; Everest, D. E., Jr.; Lovell, W. A.; Price, J. E.; Walkley, K. B.; Washburn, G. F.

1981-01-01

The speed, range, payload, and fuel efficiency of a general aviation airplane powered by one turboprop engine was determined and compared to a twin engine turboprop aircraft. An airplane configuration was developed which can carry six people for a noreserve range of 2,408 km at a cruise speed above 154 m/s, and a cruise altitude of about 9,144 m. The cruise speed is comparable to that of the fastest of the current twin turboprop powered airplanes. It is found that the airplane has a cruise specific range greater than all twin turboprop engine airplanes flying in its speed range and most twin piston engine airplanes flying at considerably slower cruise airspeeds.

Investigation of frequency-response characteristics of engine speed for a typical turbine-propeller engine

NASA Technical Reports Server (NTRS)

Taylor, Burt L , III; Oppenheimer, Frank L

1951-01-01

Experimental frequency-response characteristics of engine speed for a typical turbine-propeller engine are presented. These data were obtained by subjecting the engine to sinusoidal variations of fuel flow and propeller-blade-angle inputs. Correlation is made between these experimental data and analytical frequency-response characteristics obtained from a linear differential equation derived from steady-state torque-speed relations.

High-Throughput and Label-Free Single Nanoparticle Sizing Based on Time-Resolved On-Chip Microscopy

DTIC Science & Technology

2015-02-17

12,13 soot ,6,14 ice crystals in clouds,15 and engineered nano- materials,16 among others. While there exist various nanoparticle detection and sizing...the sample of interest is placed on an optoelectronic sensor -array with typically less than 0.5 mm gap (z2) between the sample and sensor planes such...that, under unit mag- nification, the entire sensor active area serves as the imaging FOV, easily reaching >2030 mm2 with state-of-the-art CMOS

How long does a burst burst?

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

Zhang, Bin-Bin; Connaughton, Valerie; Briggs, Michael S.

2014-05-20

Several gamma-ray bursts (GRBs) last much longer (∼hours) in γ-rays than typical long GRBs (∼minutes), and it has recently been proposed that these 'ultra-long GRBs' may form a distinct population, probably with a different (e.g., blue supergiant) progenitor than typical GRBs. However, Swift observations suggest that many GRBs have extended central engine activities manifested as flares and internal plateaus in X-rays. We perform a comprehensive study on a large sample of Swift GRBs with X-Ray Telescope observations to investigate GRB central engine activity duration and to determine whether ultra-long GRBs are unusual events. We define burst duration t {sub burst}more » based on both γ-ray and X-ray light curves rather than using γ-ray observations alone. We find that t {sub burst} can be reliably measured in 343 GRBs. Within this 'good' sample, 21.9% GRBs have t {sub burst} ≳ 10{sup 3} s and 11.5% GRBs have t {sub burst} ≳ 10{sup 4} s. There is an apparent bimodal distribution of t {sub burst} in this sample. However, when we consider an 'undetermined' sample (304 GRBs) with t {sub burst} possibly falling in the gap between GRB duration T {sub 90} and the first X-ray observational time, as well as a selection effect against t {sub burst} falling into the first Swift orbital 'dead zone' due to observation constraints, the intrinsic underlying t {sub burst} distribution is consistent with being a single component distribution. We found that the existing evidence for a separate ultra-long GRB population is inconclusive, and further multi-wavelength observations are needed to draw a firmer conclusion. We also discuss the theoretical implications of our results. In particular, the central engine activity duration of GRBs is generally much longer than the γ-ray T {sub 90} duration and it does not even correlate with T {sub 90}. It would be premature to make a direct connection between T {sub 90} and the size of the progenitor star.« less

SSME single-crystal turbine blade dynamics

NASA Technical Reports Server (NTRS)

Moss, Larry A.

1988-01-01

A study was performrd to determine the dynamic characteristics of the Space Shuttle Main Engine high pressure fuel turbopump (HPFTP) blades made of single crystal (SC) material. The first and second stage drive turbine blades of HPFTP were examined. The nonrotating natural frequencies were determined experimentally and analytically. The experimental results of the SC second stage blade were used to verify the analytical procedures. The study examined the SC first stage blade natural frequencies with respect to crystal orientation at typical operating conditions. The SC blade dynamic response was predicted to be less than the directionally solidified base. Crystal axis orientation optimization indicated that the third mode interference will exist in any SC orientation.

SSME single crystal turbine blade dynamics

NASA Technical Reports Server (NTRS)

Moss, Larry A.; Smith, Todd E.

1987-01-01

A study was performed to determine the dynamic characteristics of the Space Shuttle main engine high pressure fuel turbopump (HPFTP) blades made of single crystal (SC) material. The first and second stage drive turbine blades of HPFTP were examined. The nonrotating natural frequencies were determined experimentally and analytically. The experimental results of the SC second stage blade were used to verify the analytical procedures. The analytical study examined the SC first stage blade natural frequencies with respect to crystal orientation at typical operating conditions. The SC blade dynamic response was predicted to be less than the directionally solidified blade. Crystal axis orientation optimization indicated the third mode interference will exist in any SC orientation.

Expanding the calculation of activation volumes: Self-diffusion in liquid water

NASA Astrophysics Data System (ADS)

Piskulich, Zeke A.; Mesele, Oluwaseun O.; Thompson, Ward H.

2018-04-01

A general method for calculating the dependence of dynamical time scales on macroscopic thermodynamic variables from a single set of simulations is presented. The approach is applied to the pressure dependence of the self-diffusion coefficient of liquid water as a particularly useful illustration. It is shown how the activation volume associated with diffusion can be obtained directly from simulations at a single pressure, avoiding approximations that are typically invoked.

Circulation control propellers for general aviation, including a BASIC computer program

NASA Technical Reports Server (NTRS)

Taback, I.; Braslow, A. L.; Butterfield, A. J.

1983-01-01

The feasibility of replacing variable pitch propeller mechanisms with circulation control (Coanada effect) propellers on general aviation airplanes was examined. The study used a specially developed computer program written in BASIC which could compare the aerodynamic performance of circulation control propellers with conventional propellers. The comparison of aerodynamic performance for circulation control, fixed pitch and variable pitch propellers is based upon the requirements for a 1600 kg (3600 lb) single engine general aviation aircraft. A circulation control propeller using a supercritical airfoil was shown feasible over a representative range of design conditions. At a design condition for high speed cruise, all three types of propellers showed approximately the same performance. At low speed, the performance of the circulation control propeller exceeded the performance for a fixed pitch propeller, but did not match the performance available from a variable pitch propeller. It appears feasible to consider circulation control propellers for single engine aircraft or multiengine aircraft which have their propellers on a common axis (tractor pusher). The economics of the replacement requires a study for each specific airplane application.

Lightweight diesel aircraft engines for general aviation

NASA Technical Reports Server (NTRS)

Berenyi, S. G.; Brouwers, A. P.

1980-01-01

A methodical design study was conducted to arrive at new diesel engine configurations and applicable advanced technologies. Two engines are discussed and the description of each engine includes concept drawings. A performance analysis, stress and weight prediction, and a cost study were also conducted. This information was then applied to two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consisted of installation drawings, computer generated performance data, aircraft operating costs and drawings of the resulting airplanes. The performance data shows a vast improvement over current gasoline-powered aircraft. At the completion of this basic study, the program was expanded to evaluate a third engine configuration. This third engine incorporates the best features of the original two, and its design is currently in progress. Preliminary information on this engine is presented.

What Good Are Statistics that Don't Generalize?

ERIC Educational Resources Information Center

Shaffer, David Williamson; Serlin, Ronald C.

2004-01-01

Quantitative and qualitative inquiry are sometimes portrayed as distinct and incompatible paradigms for research in education. Approaches to combining qualitative and quantitative research typically "integrate" the two methods by letting them co-exist independently within a single research study. Here we describe intra-sample statistical analysis…

Genomics Analogy Model for Educators (GAME): VELCRO® Analogy Model to Enable the Learning of DNA Arrays for Visually Impaired and Blind Students

ERIC Educational Resources Information Center

Bello, Julia; Butler, Charles; Radavich, Rosanne; York, Alan; Oseto, Christian; Orvis, Kathryn; Pittendrigh, Barry R.

2007-01-01

Although members of the general public have often heard of the terms "genetic engineering" and, more recently, genomics, they typically have little to no knowledge about these topics, and in some cases are confused about basic concepts in these areas. There is currently a need for teaching models to explain concepts behind genomics.…

Pilot tracking performance during successive in-flight simulated instrument approaches.

DOT National Transportation Integrated Search

1972-02-01

Eight instrument rated pilots with flying experience ranging from 600 to 12,271 hours each flew 10 simulated ILS instrument approaches in a single engine, general aviation aircraft equipped with a primary flight display arranged in a conventional 'T'...

Precision Metabolic Engineering: the Design of Responsive, Selective, and Controllable Metabolic Systems

PubMed Central

McNerney, Monica P.; Watstein, Daniel M.; Styczynski, Mark P.

2015-01-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed “precision metabolic engineering,” involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. PMID:26189665

PIA: An Intuitive Protein Inference Engine with a Web-Based User Interface.

PubMed

Uszkoreit, Julian; Maerkens, Alexandra; Perez-Riverol, Yasset; Meyer, Helmut E; Marcus, Katrin; Stephan, Christian; Kohlbacher, Oliver; Eisenacher, Martin

2015-07-02

Protein inference connects the peptide spectrum matches (PSMs) obtained from database search engines back to proteins, which are typically at the heart of most proteomics studies. Different search engines yield different PSMs and thus different protein lists. Analysis of results from one or multiple search engines is often hampered by different data exchange formats and lack of convenient and intuitive user interfaces. We present PIA, a flexible software suite for combining PSMs from different search engine runs and turning these into consistent results. PIA can be integrated into proteomics data analysis workflows in several ways. A user-friendly graphical user interface can be run either locally or (e.g., for larger core facilities) from a central server. For automated data processing, stand-alone tools are available. PIA implements several established protein inference algorithms and can combine results from different search engines seamlessly. On several benchmark data sets, we show that PIA can identify a larger number of proteins at the same protein FDR when compared to that using inference based on a single search engine. PIA supports the majority of established search engines and data in the mzIdentML standard format. It is implemented in Java and freely available at https://github.com/mpc-bioinformatics/pia.

High variable mixture ratio oxygen/hydrogen engine

NASA Technical Reports Server (NTRS)

Erickson, C. M.; Tu, W. H.; Weiss, A. H.

1988-01-01

The ability of an O2/H2 engine to operate over a range of high-propellant mixture ratios was previously shown to be advantageous in single stage to orbit (SSTO) vehicles. The results are presented for the analysis of high-performance engine power cycles operating over propellant mixture ratio ranges of 12 to 6 and 9 to 6. A requirement to throttle up to 60 percent of nominal thrust was superimposed as a typical throttle range to limit vehicle acceleration as propellant is expended. The object of the analysis was to determine areas of concern relative to component and engine operability or potential hazards resulting from the operating requirements and ranges of conditions that derive from the overall engine requirements. The SSTO mission necessitates a high-performance, lightweight engine. Therefore, staged combustion power cycles employing either dual fuel-rich preburners or dual mixed (fuel-rich and oxygen-rich) preburners were examined. Engine mass flow and power balances were made and major component operating ranges were defined. Component size and arrangement were determined through engine layouts for one of the configurations evaluated. Each component is being examined to determine if there are areas of concern with respect to component efficiency, operability, reliability, or hazard. The effects of reducing the maximum chamber pressure were investigated for one of the cycles.

The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

NASA Technical Reports Server (NTRS)

Reynolds, Blake; Schecter, Harry; Taylor, E S

1939-01-01

Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.

Fan Noise Test Facility

NASA Image and Video Library

1969-01-21

The Fan Noise Test Facility built at the Lewis Research Center to obtain far-field noise data for the National Aeronautics and Space Administration (NASA) and General Electric Quiet Engine Program. The engine incorporated existing noise reduction methods into an engine of similar power to those that propelled the Boeing 707 or McDonnell-Douglas DC-8 airliner. The new the low-bypass ratio turbofan engines of the 1960s were inherently quieter than their turbojet counterparts, researchers had a better grasp of the noise generation problem, and new acoustic technologies had emerged. Lewis contracted General Electric in 1969 to build and aerodynamically test three experimental engines with 72-inch diameter fans. The engines were then brought to Lewis and tested with an acoustically treated nacelle. This Fan Noise Test Facility was built off of the 10- by 10-Foot Supersonic Wind Tunnel’s Main Compressor and Drive Building. Lewis researchers were able to isolate the fan’s noise during these initial tests by removing the core of the engine. The Lewis test rig drove engines to takeoff tip speeds of 1160 feet per second. The facility was later used to test a series of full-scale model fans and fan noise suppressors to be used with the quiet engine. NASA researchers predicted low-speed single-stage fans without inlet guide vanes and with large spacing between rotors and stators would be quieter. General Electric modified a TF39 turbofan engine by removing the the outer protion of the fan and spacing the blade rows of the inner portion. The tests revealed that the untreated version of the engine generated less noise than was anticipated, and the acoustically treated nacelle substantially reduced engine noise.

General linear methods and friends: Toward efficient solutions of multiphysics problems

NASA Astrophysics Data System (ADS)

Sandu, Adrian

2017-07-01

Time dependent multiphysics partial differential equations are of great practical importance as they model diverse phenomena that appear in mechanical and chemical engineering, aeronautics, astrophysics, meteorology and oceanography, financial modeling, environmental sciences, etc. There is no single best time discretization for the complex multiphysics systems of practical interest. We discuss "multimethod" approaches that combine different time steps and discretizations using the rigourous frameworks provided by Partitioned General Linear Methods and Generalize-structure Additive Runge Kutta Methods..

National General Aviation Design Competition Project Report

NASA Technical Reports Server (NTRS)

2001-01-01

This report summarizes the management of the National General Aviation Design Competition on behalf of NASA, the FAA and the Air Force by the Virginia Space Grant Consortium (VSGC) for the time period October 1, 1999 through September 30, 2000. This was the VSGC's sixth year of managing the Competition, which the Consortium originally designed, developed and implemented for NASA and the FAA. The seventh year of the Competition was announced in July 2000. Awards to winning university teams were presented at a ceremony held at AirVenture 2000, the Experimental Aircraft Association's Annual Convention and Fly-In at Oshkosh, WIS. NASA, FAA and AOPA administrators presented the awards. The competition calls for individuals or teams of undergraduate and graduate students from U.S. engineering schools to participate in a major national effort to rebuild the U.S. general aviation sector. For the purpose of the contest, General aviation aircraft are defined as fixed wing, single or dual engine (turbine or piston), single-pilot aircraft for 2-6 passengers. In addressing design challenges for a small aircraft transportation system, the competition seeks to raise student awareness of the importance of general aviation and to stimulate breakthroughs in technology and their application in the general aviation market. The Competition has two categories: Innovative Design, and Design It, Build It, Fly It. Awards were given in both categories for this reporting year.

Emotion Words Affect Eye Fixations during Reading

ERIC Educational Resources Information Center

Scott, Graham G.; O'Donnell, Patrick J.; Sereno, Sara C.

2012-01-01

Emotion words are generally characterized as possessing high arousal and extreme valence and have typically been investigated in paradigms in which they are presented and measured as single words. This study examined whether a word's emotional qualities influenced the time spent viewing that word in the context of normal reading. Eye movements…

Optical absorption in disordered monolayer molybdenum disulfide

NASA Astrophysics Data System (ADS)

Ekuma, C. E.; Gunlycke, D.

2018-05-01

We explore the combined impact of sulfur vacancies and electronic interactions on the optical properties of monolayer MoS2. First, we present a generalized Anderson-Hubbard Hamiltonian that accounts for both randomly distributed sulfur vacancies and the presence of dielectric screening within the material. Second, we parametrize this energy-dependent Hamiltonian from first-principles calculations based on density functional theory and the Green's function and screened Coulomb (GW) method. Third, we apply a first-principles-based many-body typical medium method to determine the single-particle electronic structure. Fourth, we solve the Bethe-Salpeter equation to obtain the charge susceptibility χ with its imaginary part being related to the absorbance A . Our results show that an increased vacancy concentration leads to decreased absorption both in the band continuum and from exciton states within the band gap. We also observe increased absorption below the band-gap threshold and present an expression, which describes Lifshitz tails, in excellent qualitative agreement with our numerical calculations. This latter increased absorption in the 1.0 -2.5 eV range makes defect engineering of potential interest for solar cell applications.

Investigation of HCCI Combustion of Diethyl Ether and Ethanol Mixtures Using Carbon 14 Tracing and Numerical Simulations

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

Mack, J H; Dibble, R W; Buchholz, B A

2004-01-16

Despite the rapid combustion typically experienced in Homogeneous Charge Compression Ignition (HCCI), components in fuel mixtures do not ignite in unison or burn equally. In our experiments and modeling of blends of diethyl ether (DEE) and ethanol (EtOH), the DEE led combustion and proceeded further toward completion, as indicated by {sup 14}C isotope tracing. A numerical model of HCCI combustion of DEE and EtOH mixtures supports the isotopic findings. Although both approaches lacked information on incompletely combusted intermediates plentiful in HCCI emissions, the numerical model and {sup 14}C tracing data agreed within the limitations of the single zone model. Despitemore » the fact that DEE is more reactive than EtOH in HCCI engines, they are sufficiently similar that we did not observe a large elongation of energy release or significant reduction in inlet temperature required for light-off, both desired effects for the combustion event. This finding suggests that, in general, HCCI combustion of fuel blends may have preferential combustion of some of the blend components.« less

Large discharge-volume, silent discharge spark plug

DOEpatents

Kang, Michael

1995-01-01

A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

Single-cone finite-difference schemes for the (2+1)-dimensional Dirac equation in general electromagnetic textures

NASA Astrophysics Data System (ADS)

Pötz, Walter

2017-11-01

A single-cone finite-difference lattice scheme is developed for the (2+1)-dimensional Dirac equation in presence of general electromagnetic textures. The latter is represented on a (2+1)-dimensional staggered grid using a second-order-accurate finite difference scheme. A Peierls-Schwinger substitution to the wave function is used to introduce the electromagnetic (vector) potential into the Dirac equation. Thereby, the single-cone energy dispersion and gauge invariance are carried over from the continuum to the lattice formulation. Conservation laws and stability properties of the formal scheme are identified by comparison with the scheme for zero vector potential. The placement of magnetization terms is inferred from consistency with the one for the vector potential. Based on this formal scheme, several numerical schemes are proposed and tested. Elementary examples for single-fermion transport in the presence of in-plane magnetization are given, using material parameters typical for topological insulator surfaces.

Optimal Tuner Selection for Kalman-Filter-Based Aircraft Engine Performance Estimation

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Garg, Sanjay

2011-01-01

An emerging approach in the field of aircraft engine controls and system health management is the inclusion of real-time, onboard models for the inflight estimation of engine performance variations. This technology, typically based on Kalman-filter concepts, enables the estimation of unmeasured engine performance parameters that can be directly utilized by controls, prognostics, and health-management applications. A challenge that complicates this practice is the fact that an aircraft engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters such as efficiencies and flow capacities related to each major engine module. Through Kalman-filter-based estimation techniques, the level of engine performance degradation can be estimated, given that there are at least as many sensors as health parameters to be estimated. However, in an aircraft engine, the number of sensors available is typically less than the number of health parameters, presenting an under-determined estimation problem. A common approach to address this shortcoming is to estimate a subset of the health parameters, referred to as model tuning parameters. The problem/objective is to optimally select the model tuning parameters to minimize Kalman-filterbased estimation error. A tuner selection technique has been developed that specifically addresses the under-determined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine that seeks to minimize the theoretical mean-squared estimation error of the Kalman filter. This approach can significantly reduce the error in onboard aircraft engine parameter estimation applications such as model-based diagnostic, controls, and life usage calculations. The advantage of the innovation is the significant reduction in estimation errors that it can provide relative to the conventional approach of selecting a subset of health parameters to serve as the model tuning parameter vector. Because this technique needs only to be performed during the system design process, it places no additional computation burden on the onboard Kalman filter implementation. The technique has been developed for aircraft engine onboard estimation applications, as this application typically presents an under-determined estimation problem. However, this generic technique could be applied to other industries using gas turbine engine technology.

46 CFR 113.35-3 - General requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM...-propelled vessel, except as provided in paragraph (d) of this section, must have an electric or mechanical... must be electrically separate and independent, except that a single mechanical operator control device...

46 CFR 113.35-3 - General requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM...-propelled vessel, except as provided in paragraph (d) of this section, must have an electric or mechanical... must be electrically separate and independent, except that a single mechanical operator control device...

46 CFR 113.35-3 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM...-propelled vessel, except as provided in paragraph (d) of this section, must have an electric or mechanical... must be electrically separate and independent, except that a single mechanical operator control device...

46 CFR 113.35-3 - General requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM...-propelled vessel, except as provided in paragraph (d) of this section, must have an electric or mechanical... must be electrically separate and independent, except that a single mechanical operator control device...

46 CFR 113.35-3 - General requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM...-propelled vessel, except as provided in paragraph (d) of this section, must have an electric or mechanical... must be electrically separate and independent, except that a single mechanical operator control device...

NASA Lewis Helps Company With New Single-Engine Business Turbojet

NASA Technical Reports Server (NTRS)

1998-01-01

Century Aerospace Corporation, a small company in Albuquerque, New Mexico, is developing a six-seat aircraft powered by a single turbofan engine for general aviation. The company had completed a preliminary design of the jet but needed analyses and testing to proceed with detailed design and subsequent fabrication of a prototype aircraft. NASA Lewis Research Center used computational fluid dynamics (CFD) analyses to ferret out areas of excessive curvature in the inlet where separation might occur. A preliminary look at the results indicated very good inlet performance; and additional calculations, performed with vortex generators installed in the inlet, led to even better results. When it was initially determined that the airflow distortion pattern at the compressor face fell outside of the limits set by the engine manufacturer, the Lewis team studied possible solutions, selected the best, and provided recommendations. CFD results for the inlet system were so good that wind tunnel tests were unnecessary.

Capturing Cyclic Variability in EGR Dilute SI Combustion using Multi-Cycle RANS

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

Scarcelli, Riccardo; Sevik, James; Wallner, Thomas

Dilute combustion is an effective approach to increase the thermal efficiency of spark-ignition (SI) internal combustion engines (ICEs). However, high dilution levels typically result in large cycle-to-cycle variations (CCV) and poor combustion stability, therefore limiting the efficiency improvement. In order to extend the dilution tolerance of SI engines, advanced ignition systems are the subject of extensive research. When simulating the effect of the ignition characteristics on CCV, providing a numerical result matching the measured average in-cylinder pressure trace does not deliver useful information regarding combustion stability. Typically Large Eddy Simulations (LES) are performed to simulate cyclic engine variations, since Reynold-Averagedmore » Navier-Stokes (RANS) modeling is expected to deliver an ensemble-averaged result. In this paper it is shown that, when using RANS, the cyclic perturbations coming from different initial conditions at each cycle are not damped out even after many simulated cycles. As a result, multi-cycle RANS results feature cyclic variability. This allows evaluating the effect of advanced ignition sources on combustion stability but requires validation against the entire cycle-resolved experimental dataset. A single-cylinder GDI research engine is simulated using RANS and the numerical results for 20 consecutive engine cycles are evaluated for several operating conditions, including stoichiometric as well as EGR dilute operation. The effect of the ignition characteristics on CCV is also evaluated. Results show not only that multi-cycle RANS simulations can capture cyclic variability and deliver similar trends as the experimental data, but more importantly that RANS might be an effective, lower-cost alternative to LES for the evaluation of ignition strategies for combustion systems that operate close to the stability limit.« less

Overview of the 1986 free-piston Stirling activities at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Alger, Donald L.

1986-01-01

An overview of the NASA Lewis Research Center's free-piston Stirling engine research is presented, including efforts to improve and advance its design for use in specific space power applications. These efforts are a part of the SP-100 program being conducted to support the Department of Defense (DOD), Department of Energy (DOE) and NASA. Such efforts include: (1) the testing and improvement of 25 kWe Stirling Space Power Demonstrator Engine (SPDE); (2) the preliminary design of 25 kWe single-cylinder Experimental stirling Space Engine (ESSE); and, (3) a study to determine the feasibility of scaling a single-cylinder free-piston Stirling engine/linear alternator to 150 kWe. Other NASA Lewis free-piston Stirling engine activities will be described, directed toward the advancement of general free-piston Stirling engine technology and its application in specific terrestrial applications. One such effort, supported by DOE/Oak Ridge National Laboratory (DRNL), is the development of a free-piston Stirling engine which produces hydraulic power. Finally, a terrestrial solar application involving a conceptual design of a 25 kWe Solar Advanced Stirling Conversion System (ASCS) capable of delivering power to an electric utility grid will be discussed. The latter work is supported by DOE/Sandia National Laboratory (SNLA).

Engineered Surfaces to Control Secondary Electron Yield for Multipactor Suppression

DTIC Science & Technology

2017-09-14

Radio Engineers ( IRE ) Transactions on Electron Devices. The first paper , published by Preist and Talcott, examined damage to RF windows in klystrons...Secondary electron emission data for aluminum referenced by Hatch in his 1961 paper showing a typical SEY (δ) curve (top) and typical energy...83 IRE : Institute of Radio Engineers

Small gas turbine engine technology

NASA Technical Reports Server (NTRS)

Niedzwiecki, Richard W.; Meitner, Peter L.

1988-01-01

Performance of small gas turbine engines in the 250 to 1,000 horsepower size range is significantly lower than that of large engines. Engines of this size are typically used in rotorcraft, commutercraft, general aviation, and cruise missile applications. Principal reasons for the lower efficiencies of a smaller engine are well known: component efficients are lower by as much as 8 to 10 percentage points because of size effects. Small engines are designed for lower cycle pressures and temperatures because of smaller blading and cooling limitations. The highly developed analytical and manufacturing techniques evolved for large engines are not directly transferrable to small engines. Thus, it was recognized that a focused effort addressing technologies for small engies was needed and could significantly impact their performance. Recently, in-house and contract studies were undertaken at the NASA Lewis Research Center to identify advanced engine cycle and component requirements for substantial performance improvement of small gas turbines for projected year 2000 applications. The results of both in-house research and contract studies are presented. In summary, projected fuel savings of 22 to 42 percent could be obtained. Accompanying direct operating cost reductions of 11 to 17 percent, depending on fuel cost, were also estimated. High payoff technologies are identified for all engine applications, and recent results of experimental research to evolve the high payoff technologies are described.

Precision metabolic engineering: The design of responsive, selective, and controllable metabolic systems.

PubMed

McNerney, Monica P; Watstein, Daniel M; Styczynski, Mark P

2015-09-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed "precision metabolic engineering," involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Advancing cognitive engineering methods to support user interface design for electronic health records.

PubMed

Thyvalikakath, Thankam P; Dziabiak, Michael P; Johnson, Raymond; Torres-Urquidy, Miguel Humberto; Acharya, Amit; Yabes, Jonathan; Schleyer, Titus K

2014-04-01

Despite many decades of research on the effective development of clinical systems in medicine, the adoption of health information technology to improve patient care continues to be slow, especially in ambulatory settings. This applies to dentistry as well, a primary care discipline with approximately 137,000 practitioners in the United States. A critical reason for slow adoption is the poor usability of clinical systems, which makes it difficult for providers to navigate through the information and obtain an integrated view of patient data. In this study, we documented the cognitive processes and information management strategies used by dentists during a typical patient examination. The results will inform the design of a novel electronic dental record interface. We conducted a cognitive task analysis (CTA) study to observe ten general dentists (five general dentists and five general dental faculty members, each with more than two years of clinical experience) examining three simulated patient cases using a think-aloud protocol. Dentists first reviewed the patient's demographics, chief complaint, medical history and dental history to determine the general status of the patient. Subsequently, they proceeded to examine the patient's intraoral status using radiographs, intraoral images, hard tissue and periodontal tissue information. The results also identified dentists' patterns of navigation through patient's information and additional information needs during a typical clinician-patient encounter. This study reinforced the significance of applying cognitive engineering methods to inform the design of a clinical system. Second, applying CTA to a scenario closely simulating an actual patient encounter helped with capturing participants' knowledge states and decision-making when diagnosing and treating a patient. The resultant knowledge of dentists' patterns of information retrieval and review will significantly contribute to designing flexible and task-appropriate information presentation in electronic dental records. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Mass driver reaction engine characteristics and performance in earth orbital transfer missions

NASA Technical Reports Server (NTRS)

Snow, W. R.; Dunbar, R. S.

1982-01-01

Configurations of a typical mass driver reaction engine (MDRE) are presented and its use for delivery of payloads to geosynchronous orbit (GEO) from low earth orbit (LEO) is discussed. Basic rocket equations are developed for LEO to GEO round-trip missions using a single exhaust velocity. It is shown that exhaust velocities in the 5-10 km/sec range (specific impulse of 500-1000 sec) are well suited for mass drivers, minimizing the overall cost of missions. Payload delivery rate fractions show that there is little to be gained by stretching out LEO to GEO transfer times from 90 to 180 days. It therefore pays to use the shorter trip time, approximately doubling the amount of delivered payload during any fixed time of use of the MDRE.

Laser-boosted lightcraft technology demonstrator

NASA Technical Reports Server (NTRS)

Richard, J. C.; Morales, C.; Smith, W. L.; Myrabo, L. N.

1990-01-01

The detailed description and performance analysis of a 1.4 meter diameter Lightcraft Technology Demonstator (LTD) is presented. The launch system employs a 100 MW-class ground-based laser to transmit power directly to an advanced combined-cycle engine that propels the 120 kg LTD to orbit - with a mass ratio of two. The single-stage-to-orbit (SSTO) LTD machine then becomes an autonomous sensor satellite that can deliver precise, high quality information typical of today's large orbital platforms. The dominant motivation behind this study is to provide an example of how laser propulsion and its low launch costs can induce a comparable order-of-magnitude reduction in sensor satellite packaging costs. The issue is simply one of production technology for future, survivable SSTO aerospace vehicles that intimately share both laser propulsion engine and satellite functional hardware.

Highly retrievable spin-wave-photon entanglement source.

PubMed

Yang, Sheng-Jun; Wang, Xu-Jie; Li, Jun; Rui, Jun; Bao, Xiao-Hui; Pan, Jian-Wei

2015-05-29

Entanglement between a single photon and a quantum memory forms the building blocks for a quantum repeater and quantum network. Previous entanglement sources are typically with low retrieval efficiency, which limits future larger-scale applications. Here, we report a source of highly retrievable spin-wave-photon entanglement. Polarization entanglement is created through interaction of a single photon with an ensemble of atoms inside a low-finesse ring cavity. The cavity is engineered to be resonant for dual spin-wave modes, which thus enables efficient retrieval of the spin-wave qubit. An intrinsic retrieval efficiency up to 76(4)% has been observed. Such a highly retrievable atom-photon entanglement source will be very useful in future larger-scale quantum repeater and quantum network applications.

On the stability and dynamics of stochastic spiking neuron models: Nonlinear Hawkes process and point process GLMs

PubMed Central

Truccolo, Wilson

2017-01-01

Point process generalized linear models (PP-GLMs) provide an important statistical framework for modeling spiking activity in single-neurons and neuronal networks. Stochastic stability is essential when sampling from these models, as done in computational neuroscience to analyze statistical properties of neuronal dynamics and in neuro-engineering to implement closed-loop applications. Here we show, however, that despite passing common goodness-of-fit tests, PP-GLMs estimated from data are often unstable, leading to divergent firing rates. The inclusion of absolute refractory periods is not a satisfactory solution since the activity then typically settles into unphysiological rates. To address these issues, we derive a framework for determining the existence and stability of fixed points of the expected conditional intensity function (CIF) for general PP-GLMs. Specifically, in nonlinear Hawkes PP-GLMs, the CIF is expressed as a function of the previous spike history and exogenous inputs. We use a mean-field quasi-renewal (QR) approximation that decomposes spike history effects into the contribution of the last spike and an average of the CIF over all spike histories prior to the last spike. Fixed points for stationary rates are derived as self-consistent solutions of integral equations. Bifurcation analysis and the number of fixed points predict that the original models can show stable, divergent, and metastable (fragile) dynamics. For fragile models, fluctuations of the single-neuron dynamics predict expected divergence times after which rates approach unphysiologically high values. This metric can be used to estimate the probability of rates to remain physiological for given time periods, e.g., for simulation purposes. We demonstrate the use of the stability framework using simulated single-neuron examples and neurophysiological recordings. Finally, we show how to adapt PP-GLM estimation procedures to guarantee model stability. Overall, our results provide a stability framework for data-driven PP-GLMs and shed new light on the stochastic dynamics of state-of-the-art statistical models of neuronal spiking activity. PMID:28234899

On the stability and dynamics of stochastic spiking neuron models: Nonlinear Hawkes process and point process GLMs.

PubMed

Gerhard, Felipe; Deger, Moritz; Truccolo, Wilson

2017-02-01

Point process generalized linear models (PP-GLMs) provide an important statistical framework for modeling spiking activity in single-neurons and neuronal networks. Stochastic stability is essential when sampling from these models, as done in computational neuroscience to analyze statistical properties of neuronal dynamics and in neuro-engineering to implement closed-loop applications. Here we show, however, that despite passing common goodness-of-fit tests, PP-GLMs estimated from data are often unstable, leading to divergent firing rates. The inclusion of absolute refractory periods is not a satisfactory solution since the activity then typically settles into unphysiological rates. To address these issues, we derive a framework for determining the existence and stability of fixed points of the expected conditional intensity function (CIF) for general PP-GLMs. Specifically, in nonlinear Hawkes PP-GLMs, the CIF is expressed as a function of the previous spike history and exogenous inputs. We use a mean-field quasi-renewal (QR) approximation that decomposes spike history effects into the contribution of the last spike and an average of the CIF over all spike histories prior to the last spike. Fixed points for stationary rates are derived as self-consistent solutions of integral equations. Bifurcation analysis and the number of fixed points predict that the original models can show stable, divergent, and metastable (fragile) dynamics. For fragile models, fluctuations of the single-neuron dynamics predict expected divergence times after which rates approach unphysiologically high values. This metric can be used to estimate the probability of rates to remain physiological for given time periods, e.g., for simulation purposes. We demonstrate the use of the stability framework using simulated single-neuron examples and neurophysiological recordings. Finally, we show how to adapt PP-GLM estimation procedures to guarantee model stability. Overall, our results provide a stability framework for data-driven PP-GLMs and shed new light on the stochastic dynamics of state-of-the-art statistical models of neuronal spiking activity.

Engineering education research in European Journal of Engineering Education and Journal of Engineering Education: citation and reference discipline analysis

NASA Astrophysics Data System (ADS)

Wankat, Phillip C.; Williams, Bill; Neto, Pedro

2014-01-01

The authors, citations and content of European Journal of Engineering Education (EJEE) and Journal of Engineering Education (JEE) in 1973 (JEE, 1975 EJEE), 1983, 1993, 2003, and available 2013 issues were analysed. Both journals transitioned from house organs to become engineering education research (EER) journals, although JEE transitioned first. In this process the number of citations rose, particularly of education and psychology sources; the percentage of research articles increased markedly as did the number of reference disciplines. The number of papers per issue, the number of single author papers, and the citations of science and engineering sources decreased. EJEE has a very broad geographic spread of authors while JEE authors are mainly US based. A 'silo' mentality where general engineering education researchers do not communicate with EER researchers in different engineering disciplines is evident. There is some danger that EER may develop into a silo that does not communicate with technically oriented engineering professors.

Performance and Operational Characteristics of a Python Turbine-propeller Engine at Simulated Altitude Conditions / Carl L. Meyer and Lavern A. Johnson

NASA Technical Reports Server (NTRS)

Meyer, Carl L; Johnson, Lavern A

1952-01-01

The performance and operational characteristics of a Python turbine-propeller engine were investigated at simulated altitude conditions in the NACA Lewis altitude wind tunnel. In the performance phase, data were obtained over a range of engine speeds and exhaust nozzle areas at altitudes from 10,000 to 40,000 feet at a single cowl-inlet ram pressure ratio; independent control of engine speed and fuel flow was used to obtain a range of powers at each engine speed. Engine performance data obtained at a given altitude could not be used to predict performance accurately at other altitudes by use of the standard air pressure and temperature generalizing factors. At a given engine speed and turbine-inlet total temperature, a greater portion of the total available energy was converted to propulsive power as the altitude increased.

DC-9 flight demonstration program with refanned JT8D engines. Volume 4: Flyover noise

NASA Technical Reports Server (NTRS)

1975-01-01

Flyover noise tests were conducted to determine the noise reductions achievable by modifying the engines and nacelles of DC-9-30 airplanes. The two stage fan of the JT8D-9 engine was replaced with a larger diameter, single stage fan and sound absorbing materials were incorporated in the engines and nacelles. The noise levels were determined to be 95.3 EPNdB at the sideline, 96.2 EPNdB for a full thrust takeoff, 87.5 EPNdB for takeoff with thrust cutback, and 97.4 EPNdB for landing approach. The noise reductions relative to the hardwall JT8D-9 were 8.2 EPNdB for takeoff with cutback and 8.7 EPNdB for landing. The 90 EPNdB noise contour areas were reduced by 40% for missions requiring maximum design takeoff and landing weights. For typical mission weights, the reductions were 19% for full thrust takeoff and 34% for takeoff with cutback. The 95 EPNdB contour areas were reduced by 50% for takeoff and 30% for takeoff with cutback for both missions.

Bacterial computing with engineered populations.

PubMed

Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

2015-07-28

We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

An Assessment of Air Force Civil Engineering Officer Perceptions of Assignments to Career Broadening Positions.

DTIC Science & Technology

1986-09-01

opportunities will determine career success (7:9). Air Force Regulation (AFR) 36-23 states that the goals of the officer assignment system are to "fulfill present...goals" (4:3). In his AFIT thesis, Cady identifies some career profiles of successful civil engineering officers. He defines career success as an...single type of experience or prescribed plan that will guarantee career success . He found’that general officers have adaptive and innovative careers with

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

NASA Technical Reports Server (NTRS)

1981-01-01

Preliminary layouts were made for the exhaust system, air induction system, and battery installation. Points of interference were identified and resolved by altering either the vehicle or engine designs. An engine general arrangement evolved to meet the vehicle engine compartment constraints while minimizing the duct pressure losses and the heat rejection. A power transfer system (between gasifier and power turbines) was developed to maintain nearly constant temperatures throughout the entire range of engine operation. An advanced four speed automatic transmission was selected to be used with the engine. Performance calculations show improvements in component efficiencies and an increase in fuel economy. A single stage centrifugal compressor design was completed and released for procurement. Gasifier turbine, power turbine, combustor, generator, secondary systems, materials, controls, and transmission development are reported.

Efficient implementation of arbitrary quantum state engineering in four-state system by counterdiabatic driving

NASA Astrophysics Data System (ADS)

Wang, Song-Bai; Chen, Ye-Hong; Wu, Qi-Cheng; Shi, Zhi-Cheng; Huang, Bi-Hua; Song, Jie; Xia, Yan

2018-07-01

A scheme is proposed to implement quantum state engineering (QSE) in a four-state system via counterdiabatic driving. In the scheme, single- and multi-mode driving methods are used respectively to drive the system to a target state at a predefined time. It is found that a fast QSE can be realized by utilizing simply designed pulses. In addition, a beneficial discussion on the energy consumption between the single- and multi-mode driving protocols shows that the multi-mode driving method seems to have a wider range of applications than the single-mode driving method with respect to different parameters. Finally, the scheme is also helpful for implementing the generalization QSE in high-dimensional systems via the concept of a dressed state. Therefore, the scheme can be implemented with the present experimental technology, which is useful in quantum information processing.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics I : effect of air bleed at compressor outlet

NASA Technical Reports Server (NTRS)

Rebeske, John J , Jr; Rohlik, Harold E

1953-01-01

An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area. A relatively simple two-step area bleed gives only a small increase in acceleration time over a corresponding variable-area bleed. For the modes of operation considered, over 84 percent of the total acceleration time was required to accelerate through the low-speed range ; therefore, better low-speed compressor performance (higher pressure ratios and efficiencies) would give a significant reduction in acceleration time.

Analysis of in-flight acoustic data for a twin-engined turboprop airplane

NASA Technical Reports Server (NTRS)

Wilby, J. F.; Wilby, E. G.

1988-01-01

Acoustic measurements were made on the exterior and interior of a general aviation turboprop airplane during four flight tests. The test conditions were carefully controlled and repeated for each flight in order to determine data variability. For the first three flights the cabin was untreated and for the fourth flight the fuselage was treated with glass fiber batts. On the exterior, measured propeller harmonic sound pressure levels showed typical standard deviations of +1.4 dB, -2.3 dB, and turbulent boundary layer pressure levels, +1.2 dB, -1.6. Propeller harmonic levels in the cabin showed greater variability, with typical standard deviations of +2.0 dB, -4.2 dB. When interior sound pressure levels from different flights with different cabin treatments were used to evaluate insertion loss, the standard deviations were typically plus or minus 6.5 dB. This is due in part to the variability of the sound pressure level measurements, but probably is also influenced by changes in the model characteristics of the cabin. Recommendations are made for the planning and performance of future flight tests to measure interior noise of propeller-driven aircraft, either high-speed advanced turboprop or general aviation propellers.

An investigation of late-combustion soot burnout in a DI diesel engine using simultaneous planar imaging of soot and OH radical

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

John E. Dec; Peter L. Kelly-Zion

Diesel engine design continues to be driven by the need to improve performance while at the same time achieving further reductions in emissions. The development of new designs to accomplish these goals requires an understanding of how the emissions are produced in the engine. Laser-imaging diagnostics are uniquely capable of providing this information, and the understanding of diesel combustion and emissions formation has been advanced considerably in recent years by their application. However, previous studies have generally focused on the early and middle stages of diesel combustion. These previous laser-imaging studies do provide important insight into the soot formation andmore » oxidation processes during the main combustion event. They indicate that prior to the end of injection, soot formation is initiated by fuel-rich premixed combustion (equivalence ratio > 4) near the upstream limit of the luminous portion of the reacting fuel jet. The soot is then oxidized at the diffusion flame around the periphery of the luminous plume. Under typical diesel engine conditions, the diffusion flame does not burn the remaining fuel and soot as rapidly as it is supplied, resulting in an expanding region of rich combustion products and soot. This is evident in natural emission images by the increasing size of the luminous soot cloud prior to the end of injection. Hence, the amount of soot in the combustion chamber typically increases until shortly after the end of fuel injection, at which time the main soot formation period ends and the burnout phase begins. Sampling valve and two-color pyrometry data indicate that the vast majority (more than 90%) of the soot formed is oxidized before combustion ends; however, it is generally thought that a small fraction of this soot from the main combustion zones is not consumed and is the source of tail pipe soot emissions.« less

Real-Time Rocket/Vehicle System Integrated Health Management Laboratory For Development and Testing of Health Monitoring/Management Systems

NASA Technical Reports Server (NTRS)

Aguilar, R.

2006-01-01

Pratt & Whitney Rocketdyne has developed a real-time engine/vehicle system integrated health management laboratory, or testbed, for developing and testing health management system concepts. This laboratory simulates components of an integrated system such as the rocket engine, rocket engine controller, vehicle or test controller, as well as a health management computer on separate general purpose computers. These general purpose computers can be replaced with more realistic components such as actual electronic controllers and valve actuators for hardware-in-the-loop simulation. Various engine configurations and propellant combinations are available. Fault or failure insertion capability on-the-fly using direct memory insertion from a user console is used to test system detection and response. The laboratory is currently capable of simulating the flow-path of a single rocket engine but work is underway to include structural and multiengine simulation capability as well as a dedicated data acquisition system. The ultimate goal is to simulate as accurately and realistically as possible the environment in which the health management system will operate including noise, dynamic response of the engine/engine controller, sensor time delays, and asynchronous operation of the various components. The rationale for the laboratory is also discussed including limited alternatives for demonstrating the effectiveness and safety of a flight system.

System controls challenges of hypersonic combined-cycle engine powered vehicles

NASA Technical Reports Server (NTRS)

Morrison, Russell H.; Ianculescu, George D.

1992-01-01

Hypersonic aircraft with air-breathing engines have been described as the most complex and challenging air/space vehicle designs ever attempted. This is particularly true for aircraft designed to accelerate to orbital velocities. The propulsion system for the National Aerospace Plane will be an active factor in maintaining the aircraft on course. Typically addressed are the difficulties with the aerodynamic vehicle design and development, materials limitations and propulsion performance. The propulsion control system requires equal materials limitations and propulsion performance. The propulsion control system requires equal concern. Far more important than merely a subset of propulsion performance, the propulsion control system resides at the crossroads of trajectory optimization, engine static performance, and vehicle-engine configuration optimization. To date, solutions at these crossroads are multidisciplinary and generally lag behind the broader performance issues. Just how daunting these demands will be is suggested. A somewhat simplified treatment of the behavioral characteristics of hypersonic aircraft and the issues associated with their air-breathing propulsion control system design are presented.

General Aviation Interior Noise. Part 1; Source/Path Identification

NASA Technical Reports Server (NTRS)

Unruh, James F.; Till, Paul D.; Palumbo, Daniel L. (Technical Monitor)

2002-01-01

There were two primary objectives of the research effort reported herein. The first objective was to identify and evaluate noise source/path identification technology applicable to single engine propeller driven aircraft that can be used to identify interior noise sources originating from structure-borne engine/propeller vibration, airborne propeller transmission, airborne engine exhaust noise, and engine case radiation. The approach taken to identify the contributions of each of these possible sources was first to conduct a Principal Component Analysis (PCA) of an in-flight noise and vibration database acquired on a Cessna Model 182E aircraft. The second objective was to develop and evaluate advanced technology for noise source ranking of interior panel groups such as the aircraft windshield, instrument panel, firewall, and door/window panels within the cabin of a single engine propeller driven aircraft. The technology employed was that of Acoustic Holography (AH). AH was applied to the test aircraft by acquiring a series of in-flight microphone array measurements within the aircraft cabin and correlating the measurements via PCA. The source contributions of the various panel groups leading to the array measurements were then synthesized by solving the inverse problem using the boundary element model.

Depot Maintenance: Air Force is Assessing Engine Maintenance Options for Work Currently Performed at Kelly Aviation Center

DTIC Science & Technology

2011-02-11

on TF39 engines, which are typically used for C-5 Galaxy aircraft; T56 engines, which are typically used for C-130 aircraft; and fuel accessories on...conducting separate cost-benefit analyses for the TF39 and T56 engine maintenance work. Under Air Force guidance for depot-level source-of-repair selection...Force has not developed specific risk mitigation plans for the TF39 or T56 engines because it is still assessing how the work will be performed

CFD modelling wall heat transfer inside a combustion chamber using ANSYS forte

NASA Astrophysics Data System (ADS)

Plengsa-ard, C.; Kaewbumrung, M.

2018-01-01

A computational model has been performed to analyze a wall heat transfer in a single cylinder, direct injection and four-stroke diesel engine. A direct integration using detailed chemistry CHEMKIN is employed in a combustion model and the Reynolds Averaged Navier Stokes (RANS) turbulence model is used to simulate the flow in the cylinder. To obtain heat flux results, a modified classical variable-density wall heat transfer model is also performed. The model is validated using experimental data from a CUMMINs engine operated with a conventional diesel combustion. One operating engine condition is simulated. Comparisons of simulated in-cylinder pressure and heat release rates with experimental data shows that the model predicts the cylinder pressure and heat release rates reasonably well. The contour plot of instantaneous temperature are presented. Also, the contours of predicted heat flux results are shown. The magnitude of peak heat fluxes as predicted by the wall heat transfer model is in the range of the typical measure values in diesel combustion.

Aural glide slope cues : their effect on pilot performance during in-flight simulated ILS instrument approaches.

DOT National Transportation Integrated Search

1971-05-01

Forty instrument rated commercial and ATR pilots with 250 to 12,271 flight hours each flew ten simulated ILS approaches in a single engine, general aviation aircraft. Divided into five groups, each group used a different glide slope cue display in co...

Steady-state simulation program for attitude control propulsion systems

NASA Technical Reports Server (NTRS)

Heinmiller, P. J.

1973-01-01

The formulation and the engineering equations employed in the steady state attitude control propulsion system simulation program are presented. The objective of this program is to aid in the preliminary design and development of propulsion systems used for spacecraft attitude control. The program simulates the integrated operation of the many interdependent components typically comprising an attitude control propulsion system. Flexibility, generality, ease of operation, and speed consistent with adequate accuracy were overriding considerations during the development of this program. Simulation modules were developed representing the various types of fluid components typically encountered in an attitude control propulsion system. These modules are basically self-contained and may be arranged by the program user into desired configuration through the program input data.

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

Buechler, Elizabeth D.; Pallin, Simon B.; Boudreaux, Philip R.

The indoor air temperature and relative humidity in residential buildings significantly affect material moisture durability, HVAC system performance, and occupant comfort. Therefore, indoor climate data is generally required to define boundary conditions in numerical models that evaluate envelope durability and equipment performance. However, indoor climate data obtained from field studies is influenced by weather, occupant behavior and internal loads, and is generally unrepresentative of the residential building stock. Likewise, whole-building simulation models typically neglect stochastic variables and yield deterministic results that are applicable to only a single home in a specific climate. The

Structural Evaluation of a Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump Turbine Blade

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali

1996-01-01

Thermal and structural finite-element analyses were performed on the first high pressure fuel turbopump turbine blade of the space shuttle main engine (SSME). A two-dimensional (2-D) finite-element model of the blade and firtree disk attachment was analyzed using the general purpose MARC (finite-element) code. The loading history applied is a typical test stand engine cycle mission, which consists of a startup condition with two thermal spikes, a steady state and a shutdown transient. The blade material is a directionally solidified (DS) Mar-M 246 alloy, the blade rotor is forged with waspalloy material. Thermal responses under steady-state and transient conditions were calculated. The stresses and strains under the influence of mechanical and thermal loadings were also determined. The critical regions that exhibited high stresses and severe localized plastic deformation were the blade-rotor gaps.

Cost/benefit analysis of advanced materials technology candidates for the 1980's, part 2

NASA Technical Reports Server (NTRS)

Dennis, R. E.; Maertins, H. F.

1980-01-01

Cost/benefit analyses to evaluate advanced material technologies projects considered for general aviation and turboprop commuter aircraft through estimated life-cycle costs, direct operating costs, and development costs are discussed. Specifically addressed is the selection of technologies to be evaluated; development of property goals; assessment of candidate technologies on typical engines and aircraft; sensitivity analysis of the changes in property goals on performance and economics, cost, and risk analysis for each technology; and ranking of each technology by relative value. The cost/benefit analysis was applied to a domestic, nonrevenue producing, business-type jet aircraft configured with two TFE731-3 turbofan engines, and to a domestic, nonrevenue producing, business type turboprop aircraft configured with two TPE331-10 turboprop engines. In addition, a cost/benefit analysis was applied to a commercial turboprop aircraft configured with a growth version of the TPE331-10.

Text Categorization for Multi-Page Documents: A Hybrid Naive Bayes HMM Approach.

ERIC Educational Resources Information Center

Frasconi, Paolo; Soda, Giovanni; Vullo, Alessandro

Text categorization is typically formulated as a concept learning problem where each instance is a single isolated document. This paper is interested in a more general formulation where documents are organized as page sequences, as naturally occurring in digital libraries of scanned books and magazines. The paper describes a method for classifying…

Syntactic, Semantic and Pragmatic Correlates of the Acquisition of Exhaustivity in "Wh"-Questions: A Study of Polish Monolingual Children

ERIC Educational Resources Information Center

Forys-Nogala, Malgorzata; Haman, Ewa; Katsos, Napoleon; Krajewski, Grzegorz; Schulz, Petra

2017-01-01

This study investigates relationships between acquisition of exhaustivity in single and multiple "wh"-questions, mastery of semantic and pragmatic aspects of quantifier comprehension, and general skills in receptive grammar. The participants of the study were 25 Polish monolingual typically developing children aged 4;02-6;02, who were…

Flexible Animation Computer Program

NASA Technical Reports Server (NTRS)

Stallcup, Scott S.

1990-01-01

FLEXAN (Flexible Animation), computer program animating structural dynamics on Evans and Sutherland PS300-series graphics workstation with VAX/VMS host computer. Typical application is animation of spacecraft undergoing structural stresses caused by thermal and vibrational effects. Displays distortions in shape of spacecraft. Program displays single natural mode of vibration, mode history, or any general deformation of flexible structure. Written in FORTRAN 77.

State variable modeling of the integrated engine and aircraft dynamics

NASA Astrophysics Data System (ADS)

Rotaru, Constantin; Sprinţu, Iuliana

2014-12-01

This study explores the dynamic characteristics of the combined aircraft-engine system, based on the general theory of the state variables for linear and nonlinear systems, with details leading first to the separate formulation of the longitudinal and the lateral directional state variable models, followed by the merging of the aircraft and engine models into a single state variable model. The linearized equations were expressed in a matrix form and the engine dynamics was included in terms of variation of thrust following a deflection of the throttle. The linear model of the shaft dynamics for a two-spool jet engine was derived by extending the one-spool model. The results include the discussion of the thrust effect upon the aircraft response when the thrust force associated with the engine has a sizable moment arm with respect to the aircraft center of gravity for creating a compensating moment.

High Reliability Engine Control Demonstrated for Aircraft Engines

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei

1999-01-01

For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

Low emissions diesel fuel

DOEpatents

Compere, Alicia L.; Griffith, William L.; Dorsey, George F.; West, Brian H.

1998-01-01

A method and matter of composition for controlling NO.sub.x emissions from existing diesel engines. The method is achieved by adding a small amount of material to the diesel fuel to decrease the amount of NO.sub.x produced during combustion. Specifically, small amounts, less than about 1%, of urea or a triazine compound (methylol melamines) are added to diesel fuel. Because urea and triazine compounds are generally insoluble in diesel fuel, microemulsion technology is used to suspend or dissolve the urea or triazine compound in the diesel fuel. A typical fuel formulation includes 5% t-butyl alcohol, 4.5% water, 0.5% urea or triazine compound, 9% oleic acid, and 1% ethanolamine. The subject invention provides improved emissions in heavy diesel engines without the need for major modifications.

Low emissions diesel fuel

DOEpatents

Compere, A.L.; Griffith, W.L.; Dorsey, G.F.; West, B.H.

1998-05-05

A method and matter of composition for controlling NO{sub x} emissions from existing diesel engines. The method is achieved by adding a small amount of material to the diesel fuel to decrease the amount of NO{sub x} produced during combustion. Specifically, small amounts, less than about 1%, of urea or a triazine compound (methylol melamines) are added to diesel fuel. Because urea and triazine compounds are generally insoluble in diesel fuel, microemulsion technology is used to suspend or dissolve the urea or triazine compound in the diesel fuel. A typical fuel formulation includes 5% t-butyl alcohol, 4.5% water, 0.5% urea or triazine compound, 9% oleic acid, and 1% ethanolamine. The subject invention provides improved emissions in heavy diesel engines without the need for major modifications.

Criticality in Bulk Metallic Glass Constituent Elements

NASA Astrophysics Data System (ADS)

Mota, Rodrigo Miguel Ojeda; Graedel, T. E.; Pekarskaya, Evgenia; Schroers, Jan

2017-11-01

Bulk metallic glasses (BMGs), which readily form amorphous phases during solidification, are increasingly being used in first applications of watch components, electronic casings, and sporting goods. The compositions of BMGs typically include four to six elements. Various political and geological factors have recently led to supply disruptions for several metals, including some present in BMG compositions. In this work, we assess the "criticality" of 22 technologically interesting BMG compositions, compare the results with those for three common engineering alloy groups, and derive recommendations for BMG composition choices from a criticality perspective. The criticality of BMGs is found to be generally much higher compared with those for the established engineering alloys. Therefore, criticality concerns should also be considered in the choice between existing and developing novel BMGs.

Texturing Silicon Nanowires for Highly Localized Optical Modulation of Cellular Dynamics.

PubMed

Fang, Yin; Jiang, Yuanwen; Acaron Ledesma, Hector; Yi, Jaeseok; Gao, Xiang; Weiss, Dara E; Shi, Fengyuan; Tian, Bozhi

2018-06-18

Engineered silicon-based materials can display photoelectric and photothermal responses under light illumination, which may lead to further innovations at the silicon-biology interfaces. Silicon nanowires have small radial dimensions, promising as highly localized cellular modulators, however the single crystalline form typically has limited photothermal efficacy due to the poor light absorption and fast heat dissipation. In this work, we report strategies to improve the photothermal response from silicon nanowires by introducing nanoscale textures on the surface and in the bulk. We next demonstrate high-resolution extracellular modulation of calcium dynamics in a number of mammalian cells including glial cells, neurons, and cancer cells. The new materials may be broadly used in probing and modulating electrical and chemical signals at the subcellular length scale, which is currently a challenge in the field of electrophysiology or cellular engineering.

Use of an air-assisted fuel nozzle to reduce idle emissions of a jt8d engine combustor

NASA Technical Reports Server (NTRS)

Papathakos, L. C.; Jones, R. E.

1973-01-01

Tests were performed at typical engine idle conditions on a single-can JT8D combustor installed in a 24 centimeter (9.45 in.) housing to evaluate the effect of an air-assist nozzle on reducing exhaust emissions. By injecting high-pressure air through the secondary-flow passage of a standard duplex fuel nozzle, it was possible to reduce hydrocarbon emissions from 840 parts per million to 95 parts per million and carbon monoxide emissions from 873 parts per million to 258 parts per million. NOX emissions increased slightly from 18 parts per million to 22 parts per million. An air-assist differential pressure of only 20.1 newtons per square centimeter (29.1 psi) and an airflow rate of only 0.22 percent of the total combustor airflow was required.

A model for predicting propagation-related DSCS (Defense Communications Engineering Center) margin requirements

NASA Astrophysics Data System (ADS)

Shultheis, C. F.

1985-02-01

This technical report describes an analysis of the performance allocations for a satellite link, focusing specifically on a single-hop 7 to 8 GHz link of the Defense Satellite Communications System (DSCS). The analysis is performed for three primary reasons: (1) to reevaluate link power margin requirements for DSCS links based on digital signalling; (2) to analyze the implications of satellite availability and error rate allocations contained in proposed MIL-STD-188-323, system design and engineering standards for long haul digital transmission system performance; and (3) to standardize a methodology for determination of rain-related propagation constraints. The aforementioned methodology is then used to calculate the link margin requirements of typical DSCS binary/quaternary phase shift keying (BPSK/QPSK) links at 7 to 8 GHz for several different Earth terminal locations.

Design and test of aircraft engine isolators for reduced interior noise

NASA Technical Reports Server (NTRS)

Unruh, J. F.; Scheidt, D. C.

1982-01-01

Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft. A study was carried out the objectives: (1) to develop an engine isolator design specification for reduced interior noise transmission, (2) select/design candidate isolators to meet a 15 dB noise reduction design goal, and (3) carry out a proof of concept evaluation test. Analytical model of the engine, vibration isolators and engine mount structure were coupled to an empirical model of the fuselage for noise transmission evaluation. The model was used to develop engine isolator dynamic properties design specification for reduced noise transmission. Candidate isolators ere chosen from available product literature and retrofit to a test aircraft. A laboratory based test procedure was then developed to simulate engine induced noise transmission in the aircraft for a proof of concept evaluation test. Three candidate isolator configurations were evaluated for reduced structure-borne noise transmission relative to the original equipment isolators.

The crystallization and structural analysis of cellulases (and other glycoside hydrolases): strategies and tactics.

PubMed

Roberts, Shirley M; Davies, Gideon J

2012-01-01

The three-dimensional (3-D) structures of cellulases, and other glycoside hydrolases, are a central feature of research in carbohydrate chemistry and biochemistry. 3-D structure is used to inform protein engineering campaigns, both academic and industrial, which are typically used to improve the stability or activity of an enzyme. Examples of classical protein engineering goals include higher thermal stability, reduced metal-ion dependency, detergent and protease resistance, decreased product inhibition, and altered specificity. 3-D structure may also be used to interpret the behavior of enzyme variants that are derived from screening or random mutagenesis approaches, with a view to establishing an iterative design process. In other areas, 3-D structure is used as one of the many tools to probe enzymatic catalysis, typically dovetailing with physical organic chemistry approaches to provide complete reaction mechanisms for enzymes by visualizing catalytic site interactions at different stages of the reaction. Such mechanistic insight is not only fundamentally important, impacting on inhibitor and drug design approaches with ramifications way beyond cellulose hydrolysis, but also provides the framework for the design of enzyme variants to use as biocatalysts for the synthesis of bespoke oligosaccharides. Here we review some of the strategies and tactics that may be applied to the X-ray structure solution of cellulases (and other carbohydrate-active enzymes). The general approach is first to decide why you are doing the work, then to establish correct domain boundaries for truncated constructs (typically the catalytic domain only), and finally to pursue crystallization of pure, homogeneous, and monodisperse protein with appropriate ligand and additive combinations. Cellulase-specific strategies are important for the delineation of domain boundaries, while glycoside hydrolases generally also present challenges and opportunities for the selection and optimization of ligands to both aid crystallization, and also provide structural and mechanistic insight. As the many roles for plant cell wall degrading enzymes increase, so does the need for rapid high-quality structure determination to provide a sound structural foundation for understanding mechanism and specificity, and for future protein engineering strategies. Copyright © 2012 Elsevier Inc. All rights reserved.

Joint US/Russia TU-144 Engine Ground Tests

NASA Technical Reports Server (NTRS)

Acosta, Waldo A.; Balser, Jeffrey S.; McCartney, Timothy P.; Richter, Charles A.; Woike, Mark R.

1997-01-01

Two engine research experiments were recently completed in Moscow, Russia using an engine from the Tu-144 supersonic transport airplane. This was a joint project between the United States and Russia. Personnel from the NASA Lewis Research Center, General Electric Aircraft Engines, Pratt & Whitney, the Tupolev Design Bureau, and EBP Aircraft LTD worked together as a team to overcome the many technical and cultural challenges. The objective was to obtain large scale inlet data that could be used in the development of a supersonic inlet system for a future High Speed Civil Transport (HSCT). The-first experiment studied the impact of typical inlet structures that have trailing edges in close proximity to the inlet/engine interface plane on the flow characteristics at that plane. The inlet structure simulated the subsonic diffuser of a supersonic inlet using a bifurcated splitter design. The centerbody maximum diameter was designed to permit choking and slightly supercritical operation. The second experiment measured the reflective characteristics of the engine face to incoming perturbations of pressure amplitude. The basic test rig from the first experiment was used with a longer spacer equipped with fast actuated doors. All the objectives set forth at the beginning of the project were met.

Weighted reciprocal of temperature, weighted thermal flux, and their applications in finite-time thermodynamics.

PubMed

Sheng, Shiqi; Tu, Z C

2014-01-01

The concepts of weighted reciprocal of temperature and weighted thermal flux are proposed for a heat engine operating between two heat baths and outputting mechanical work. With the aid of these two concepts, the generalized thermodynamic fluxes and forces can be expressed in a consistent way within the framework of irreversible thermodynamics. Then the efficiency at maximum power output for a heat engine, one of key topics in finite-time thermodynamics, is investigated on the basis of a generic model under the tight-coupling condition. The corresponding results have the same forms as those of low-dissipation heat engines [ M. Esposito, R. Kawai, K. Lindenberg and C. Van den Broeck Phys. Rev. Lett. 105 150603 (2010)]. The mappings from two kinds of typical heat engines, such as the low-dissipation heat engine and the Feynman ratchet, into the present generic model are constructed. The universal efficiency at maximum power output up to the quadratic order is found to be valid for a heat engine coupled symmetrically and tightly with two baths. The concepts of weighted reciprocal of temperature and weighted thermal flux are also transplanted to the optimization of refrigerators.

Potential end-to-end imaging information rate advantages of various alternative communication systems

NASA Technical Reports Server (NTRS)

Rice, R. F.

1978-01-01

Various communication systems were considered which are required to transmit both imaging and a typically error sensitive, class of data called general science/engineering (gse) over a Gaussian channel. The approach jointly treats the imaging and gse transmission problems, allowing comparisons of systems which include various channel coding and data compression alternatives. Actual system comparisons include an Advanced Imaging Communication System (AICS) which exhibits the rather significant potential advantages of sophisticated data compression coupled with powerful yet practical channel coding.

Optimal dual-fuel propulsion for minimum inert weight or minimum fuel cost

NASA Technical Reports Server (NTRS)

Martin, J. A.

1973-01-01

An analytical investigation of single-stage vehicles with multiple propulsion phases has been conducted with the phasing optimized to minimize a general cost function. Some results are presented for linearized sizing relationships which indicate that single-stage-to-orbit, dual-fuel rocket vehicles can have lower inert weight than similar single-fuel rocket vehicles and that the advantage of dual-fuel vehicles can be increased if a dual-fuel engine is developed. The results also indicate that the optimum split can vary considerably with the choice of cost function to be minimized.

Dynamics of the inlet system of a four-stroke engine

NASA Technical Reports Server (NTRS)

Boden, R H; Schecter, Harry

1944-01-01

Tests were run on a single-cylinder and a multicylinder four-stroke engine in order to determine the effect of the dynamics of the inlet system upon indicated mean effective pressure. Tests on the single-cylinder engine were made at various speeds, inlet valve timings, and inlet pipe lengths. These tests indicated that the indicated mean effective pressure could be raised considerably at any one speed by the use of a suitably long inlet pipe. Tests at other speeds with this length of pipe showed higher indicated mean effective pressure than with a very short pipe, although not so high as could be obtained with the pipe length adjusted for each speed. A general relation was discovered between optimum time of inlet valve closing and pipe length; namely, that longer pipes require later inlet valve closing in order to be fully effective. Tests were also made on three cylinders connected to a single pipe. With this arrangement, increased volumetric efficiency at low speed was obtainable by using a long pipe, but only with a sacrifice of volumetric efficiency at high speed. Volumetric efficiency at high speed was progressively lower as the pipe length was increased.

Attributes and characteristics of the Mathematics, Engineering, Science, Achievement (MESA) high school program for first-generation Latino students

NASA Astrophysics Data System (ADS)

Flores, Ramon

This study used a web-based survey collected data from 28 first-generation Latino engineers who participated in the Mathematics, Engineering, Science, Achievement (MESA) program during their high school years. From the set of 28 respondents, 5 volunteered to participate in an optional telephone interview. The purpose of this study was to describe the critical attributes and characteristics of the MESA program that lead to success at both the high school and college levels for first-generation Latino students. Success at the high school level was operationally defined as successfully graduating with a high school diploma. Success at the college level was operationally defined here as college graduation with an engineering degree. Using a mixed-methods technique, the researcher attempted to secure consensus of opinion from a sample population of 28 first-generation Latino engineers. The mixed-methods technique was chosen since it allowed the researcher to draw on the strengths of quantitative and qualitative approaches. According to the findings, the typical respondent felt that mentoring was the attribute of the MESA program that most prepared him to graduate from high school. The respondents felt that the following MESA attributes most helped them transition into an undergraduate engineering program: Academic and University Advising; Enrichment Activities; Career Advising; Field Trips; Mentoring; Scholarship Incentive Awards; and Speakers. The respondents viewed study groups as the MESA attribute that best prepared them to graduate college with an engineering degree. This study was purposefully designed as a descriptive study. Future research is required to extend this work into an evaluative study. This would allow for the generalization of the critical attributes to the general student population serviced by the MESA program.

Cell delivery in regenerative medicine: the cell sheet engineering approach.

PubMed

Yang, Joseph; Yamato, Masayuki; Nishida, Kohji; Ohki, Takeshi; Kanzaki, Masato; Sekine, Hidekazu; Shimizu, Tatsuya; Okano, Teruo

2006-11-28

Recently, cell-based therapies have developed as a foundation for regenerative medicine. General approaches for cell delivery have thus far involved the use of direct injection of single cell suspensions into the target tissues. Additionally, tissue engineering with the general paradigm of seeding cells into biodegradable scaffolds has also evolved as a method for the reconstruction of various tissues and organs. With success in clinical trials, regenerative therapies using these approaches have therefore garnered significant interest and attention. As a novel alternative, we have developed cell sheet engineering using temperature-responsive culture dishes, which allows for the non-invasive harvest of cultured cells as intact sheets along with their deposited extracellular matrix. Using this approach, cell sheets can be directly transplanted to host tissues without the use of scaffolding or carrier materials, or used to create in vitro tissue constructs via the layering of individual cell sheets. In addition to simple transplantation, cell sheet engineered constructs have also been applied for alternative therapies such as endoscopic transplantation, combinatorial tissue reconstruction, and polysurgery to overcome limitations of regenerative therapies and cell delivery using conventional approaches.

Control Performance of General Electric Fuel and Torque Regulator Operating on T31-3 Turbine-Propeller Engine in Sea-Level Test Stand

NASA Technical Reports Server (NTRS)

Oppenheimer, Frank L.; Lazar, James

1951-01-01

A .General Electric fuel and torque regulator was tested in conjunction with a T31-3 turbine-propeller engine in the sea-level static test stand at the NACA Lewis laboratory. The engine and control were operated over the entire speed range: 11,000 rpm, nominal flight idle, to 13,000 rpm, full power. Steady-state and transient data were recorded and are presented with a description of the four control loops being used in the system. Results of this investigation indicated that single-lever control operation was satisfactory under conditions of test. Transient data presented showed that turbine-outlet temperature did overshoot maximum operating value on acceleration but that the time duration of overshoot did not exceed approximately 1 second. This temperature limiting resulted from a control on fuel flow as a function of engine speed. Speed and torque first reached their desired values 0.4 second from the time of change in power-setting lever position. Maximum speed overshoot was 3 percent.

An ROI Comparison of Initiatives Designed to Attract Diverse Students to Technology Careers

ERIC Educational Resources Information Center

Dillon, Thomas W.; Reif, Harry L.; Thomas, Daphyne S.

2016-01-01

This study examines two alternative interventions designed to attract diverse students to pursue information technology or, more generally, STEM (science, technology, engineering, and math) careers from a Return on Investment (ROI) perspective. More specifically, this study examines the effectiveness and efficiency of single-day and multi-day…

Tempest gas turbine extends EGT product line

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

Chellini, R.

With the introduction of the 7.8 MW (mechanical output) Tempest gas turbine, ECT has extended the company`s line of its small industrial turbines. The new Tempest machine, featuring a 7.5 MW electric output and a 33% thermal efficiency, ranks above the company`s single-shaft Typhoon gas turbine, rated 3.2 and 4.9 MW, and the 6.3 MW Tornado gas turbine. All three machines are well-suited for use in combined heat and power (CHP) plants, as demonstrated by the fact that close to 50% of the 150 Typhoon units sold are for CHP applications. This experience has induced EGT, of Lincoln, England, tomore » announce the introduction of the new gas turbine prior to completion of the testing program. The present single-shaft machine is expected to be used mainly for industrial trial cogeneration. This market segment, covering the needs of paper mills, hospitals, chemical plants, ceramic industry, etc., is a typical local market. Cogeneration plants are engineered according to local needs and have to be assisted by local organizations. For this reason, to efficiently cover the world market, EGT has selected a number of associates that will receive from Lincoln completely engineered machine packages and will engineer the cogeneration system according to custom requirements. These partners will also assist the customer and dispose locally of the spares required for maintenance operations.« less

Endoreversible quantum heat engines in the linear response regime.

PubMed

Wang, Honghui; He, Jizhou; Wang, Jianhui

2017-07-01

We analyze general models of quantum heat engines operating a cycle of two adiabatic and two isothermal processes. We use the quantum master equation for a system to describe heat transfer current during a thermodynamic process in contact with a heat reservoir, with no use of phenomenological thermal conduction. We apply the endoreversibility description to such engine models working in the linear response regime and derive expressions of the efficiency and the power. By analyzing the entropy production rate along a single cycle, we identify the thermodynamic flux and force that a linear relation connects. From maximizing the power output, we find that such heat engines satisfy the tight-coupling condition and the efficiency at maximum power agrees with the Curzon-Ahlborn efficiency known as the upper bound in the linear response regime.

X-33 XRS-2200 Linear Aerospike Engine Sea Level Plume Radiation

NASA Technical Reports Server (NTRS)

DAgostino, Mark G.; Lee, Young C.; Wang, Ten-See; Turner, Jim (Technical Monitor)

2001-01-01

Wide band plume radiation data were collected during ten sea level tests of a single XRS-2200 engine at the NASA Stennis Space Center in 1999 and 2000. The XRS-2200 is a liquid hydrogen/liquid oxygen fueled, gas generator cycle linear aerospike engine which develops 204,420 lbf thrust at sea level. Instrumentation consisted of six hemispherical radiometers and one narrow view radiometer. Test conditions varied from 100% to 57% power level (PL) and 6.0 to 4.5 oxidizer to fuel (O/F) ratio. Measured radiation rates generally increased with engine chamber pressure and mixture ratio. One hundred percent power level radiation data were compared to predictions made with the FDNS and GASRAD codes. Predicted levels ranged from 42% over to 7% under average test values.

Graded metascreens to enable a new degree of nanoscale light management

PubMed Central

Mohammadi Estakhri, Nasim; Argyropoulos, Christos; Alù, Andrea

2015-01-01

Optical metasurfaces, typically referred to as two-dimensional metamaterials, are arrays of engineered subwavelength inclusions suitably designed to tailor the light properties, including amplitude, phase and polarization state, over deeply subwavelength scales. By exploiting anomalous localized interactions of surface elements with optical waves, metasurfaces can go beyond the functionalities offered by conventional diffractive optical gratings. The innate simplicity of implementation and the distinct underlying physics of their wave–matter interaction distinguish metasurfaces from three-dimensional metamaterials and provide a valuable means of moulding optical waves in the desired manner. Here, we introduce a general approach based on the electromagnetic equivalence principle to develop and synthesize graded, non-periodic metasurfaces to generate arbitrarily prescribed distributions of electromagnetic waves. Graded metasurfaces are realized with a single layer of spatially modulated, electrically polarizable nanoparticles, tailoring the scattering response of the surface with nanoscale resolutions. We discuss promising applications based on the proposed local wave management technique, including the design of ultrathin optical carpet cloaks, alignment-free polarization beam splitters and a novel approach to enable broadband light absorption enhancement in thin-film solar cells. This concept opens up a practical route towards efficient planarized optical structures with potential impact on the integrated nanophotonic technology. PMID:26217059

Quantum measurement-induced dynamics of many-body ultracold bosonic and fermionic systems in optical lattices

NASA Astrophysics Data System (ADS)

Mazzucchi, Gabriel; Kozlowski, Wojciech; Caballero-Benitez, Santiago F.; Elliott, Thomas J.; Mekhov, Igor B.

2016-02-01

Trapping ultracold atoms in optical lattices enabled numerous breakthroughs uniting several disciplines. Coupling these systems to quantized light leads to a plethora of new phenomena and has opened up a new field of study. Here we introduce an unusual additional source of competition in a many-body strongly correlated system: We prove that quantum backaction of global measurement is able to efficiently compete with intrinsic short-range dynamics of an atomic system. The competition becomes possible due to the ability to change the spatial profile of a global measurement at a microscopic scale comparable to the lattice period without the need of single site addressing. In coherence with a general physical concept, where new competitions typically lead to new phenomena, we demonstrate nontrivial dynamical effects such as large-scale multimode oscillations, long-range entanglement, and correlated tunneling, as well as selective suppression and enhancement of dynamical processes beyond the projective limit of the quantum Zeno effect. We demonstrate both the breakup and protection of strongly interacting fermion pairs by measurement. Such a quantum optical approach introduces into many-body physics novel processes, objects, and methods of quantum engineering, including the design of many-body entangled environments for open systems.

Engineered cell-cell communication via DNA messaging

PubMed Central

2012-01-01

Background Evolution has selected for organisms that benefit from genetically encoded cell-cell communication. Engineers have begun to repurpose elements of natural communication systems to realize programmed pattern formation and coordinate other population-level behaviors. However, existing engineered systems rely on system-specific small molecules to send molecular messages among cells. Thus, the information transmission capacity of current engineered biological communication systems is physically limited by specific biomolecules that are capable of sending only a single message, typically “regulate transcription.” Results We have engineered a cell-cell communication platform using bacteriophage M13 gene products to autonomously package and deliver heterologous DNA messages of varying lengths and encoded functions. We demonstrate the decoupling of messages from a common communication channel via the autonomous transmission of various arbitrary genetic messages. Further, we increase the range of engineered DNA messaging across semisolid media by linking message transmission or receipt to active cellular chemotaxis. Conclusions We demonstrate decoupling of a communication channel from message transmission within engineered biological systems via the autonomous targeted transduction of user-specified heterologous DNA messages. We also demonstrate that bacteriophage M13 particle production and message transduction occurs among chemotactic bacteria. We use chemotaxis to improve the range of DNA messaging, increasing both transmission distance and communication bit rates relative to existing small molecule-based communication systems. We postulate that integration of different engineered cell-cell communication platforms will allow for more complex spatial programming of dynamic cellular consortia. PMID:22958599

Supporting multiple domains in a single reuse repository

NASA Technical Reports Server (NTRS)

Eichmann, David A.

1992-01-01

Domain analysis typically results in the construction of a domain-specific repository. Such a repository imposes artificial boundaries on the sharing of similar assets between related domains. A lattice-based approach to repository modeling can preserve a reuser's domain specific view of the repository, while avoiding replication of commonly used assets and supporting a more general perspective on domain interrelationships.

General solutions for the oxidation kinetics of polymers

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

Gillen, K.T.; Clough, R.L.; Wise, J.

1996-08-01

The simplest general kinetic schemes applicable to the oxidation of polymers are presented, discussed and analyzed in terms of the underlying kinetic assumptions. For the classic basic autoxidation scheme (BAS), which involves three bimolecular termination steps and is applicable mainly to unstabilized polymers, typical assumptions used singly or in groups include (1) long kinetic chain length, (2) a specific ratio of the termination rate constants and (3) insensitivity to the oxygen concentration (e.g., domination by a single termination step). Steady-state solutions for the rate of oxidation are given in terms of one, two, three, or four parameters, corresponding respectively tomore » three, two, one, or zero kinetic assumptions. The recently derived four-parameter solution predicts conditions yielding unusual dependencies of the oxidation rate on oxygen concentration and on initiation rate, as well as conditions leading to some unusual diffusion-limited oxidation profile shapes. For stabilized polymers, unimolecular termination schemes are typically more appropriate than bimolecular. Kinetics incorporating unimolecular termination reactions are shown to result in very simple oxidation expressions which have been experimentally verified for both radiation-initiated oxidation of an EPDM and thermoxidative degradation of nitrile and chloroprene elastomers.« less

Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

2012-01-01

The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

Models and methods in delay discounting.

PubMed

Tesch, Aaron D; Sanfey, Alan G

2008-04-01

Delay discounting (DD) is a term typically used to describe the devaluation of rewards over time, and much research across a wide variety of domains has illustrated that people in general prefer a smaller reward delivered soon as opposed to a larger reward delivered at a later stage. Despite numerous attempts, a single unified model of DD that accounts for the varied pattern of results typically observed has been elusive. One of the difficulties in deriving a unified model is the presence of many framing and context effects, situations in which changing, apparently irrelevant, aspects of the choice scenarios lead to different selections. Additionally, different paradigms of DD research use quite different methodology, which poses challenges for a unified model. This chapter describes some of the difficulties in creating a single DD model and suggests some experiments that would help integrate different paradigms to create a clearer picture of DD.

Full-Scale Investigation of Aerodynamic Characteristics of a Typical Single-Sotor Helicopter in Forward Flight

NASA Technical Reports Server (NTRS)

Dingeldein, Richard C; Schaefer, Raymond F

1948-01-01

As part of the general helicopter research program being undertaken by the National Advisory Committee for Aeronautics to provide designers with fundamental rotor information, the forward-flight performance characteristics of a typical single-rotor helicopter, which is equipped with main and tail rotors, have been investigated in the Langley full-scale tunnel. The test conditions included operation of tip-speed ratios from 0.10 to 0.27 and at thrust coefficients from 0.0030 to 0.0060. Results obtained with production rotor were compared with those for an alternate set of blades having closer rib spacing and a smoother and more accurately contoured surface in order to evaluate the performance gains that are available by the use of rotor blades having an improved surface condition. The wind tunnel results are shown to be in fair agreement with the results of both flight tests and theoretical predictions.

Simulated Single Tooth Bending of High Temperature Alloys

NASA Technical Reports Server (NTRS)

Handschuh, Robert, F.; Burke, Christopher

2012-01-01

Future unmanned space missions will require mechanisms to operate at extreme conditions in order to be successful. In some of these mechanisms, very high gear reductions will be needed to permit very small motors to drive other components at low rotational speed with high output torque. Therefore gearing components are required that can meet the mission requirements. In mechanisms such as this, bending fatigue strength capacity of the gears is very important. The bending fatigue capacity of a high temperature, nickel-based alloy, typically used for turbine disks in gas turbine engines and two tool steel materials with high vanadium content, were compared to that of a typical aerospace alloy-AISI 9310. Test specimens were fabricated by electro-discharge machining without post machining processing. Tests were run at 24 and at 490 C. As test temperature increased from 24 to 490 C the bending fatigue strength was reduced by a factor of five.

Efficient estimation of the maximum metabolic productivity of batch systems

DOE PAGES

St. John, Peter C.; Crowley, Michael F.; Bomble, Yannick J.

2017-01-31

Production of chemicals from engineered organisms in a batch culture involves an inherent trade-off between productivity, yield, and titer. Existing strategies for strain design typically focus on designing mutations that achieve the highest yield possible while maintaining growth viability. While these methods are computationally tractable, an optimum productivity could be achieved by a dynamic strategy in which the intracellular division of resources is permitted to change with time. New methods for the design and implementation of dynamic microbial processes, both computational and experimental, have therefore been explored to maximize productivity. However, solving for the optimal metabolic behavior under the assumptionmore » that all fluxes in the cell are free to vary is a challenging numerical task. Here, previous studies have therefore typically focused on simpler strategies that are more feasible to implement in practice, such as the time-dependent control of a single flux or control variable.« less

Mini-Satellites for Affordable Space Science

NASA Astrophysics Data System (ADS)

Phipps, Andy; da Silva Curiel, Alex; Gibbon, Dave; Richardson, Guy; Cropp, Alex; Sweeting, Martin, , Sir

Magnetospheric science missions are a key component of solar terrestrial physics programmes - charged with the unravelling of these fundamental processes. These missions require distributed science gathering in a wide variety of alternative orbits. Missions typically require constellations of high delta-v formation flying spacecraft - single launch vehicles are usually mandated. Typical missions baseline space standard technology and standard communication and operations architectures - all driving up programme cost. By trading on the requirements, applying prudent analysis of performance as well as selection of subsystems outside the traditional space range most of the mission objectives can be met for a reduced overall mission cost. This paper describes Surrey's platform solution which has been studied for a future NASA opportunity. It will emphasise SSTL's proven spacecraft engineering philosophies and the use of terrestrial commercial off-the-shelf technology in this demanding environment. This will lead to a cost-capped science mission, and extend the philosophy of affordable access to space beyond Low Earth Orbit.

Engineers have more sons, nurses have more daughters: an evolutionary psychological extension of Baron-Cohen's extreme male brain theory of autism.

PubMed

Kanazawa, Satoshi; Vandermassen, Griet

2005-04-21

In his extreme male brain theory of autism, Baron-Cohen postulates that having a typically male brain was adaptive for ancestral men and having a typically female brain was adaptive for ancestral women. He also suggests that brain types are substantially heritable. These postulates, combined with the insight from the Trivers-Willard hypothesis regarding parental ability to vary offspring sex ratio, lead to the prediction that people who have strong male brains should have more sons than daughters, and people who have strong female brains should have more daughters than sons. The analysis of the 1994 US General Social Survey data provides support for this prediction. Our results suggest potentially fruitful extensions of both Baron-Cohen's theory and the Trivers-Willard hypothesis.

Two coupled, driven Ising spin systems working as an engine.

PubMed

Basu, Debarshi; Nandi, Joydip; Jayannavar, A M; Marathe, Rahul

2017-05-01

Miniaturized heat engines constitute a fascinating field of current research. Many theoretical and experimental studies are being conducted that involve colloidal particles in harmonic traps as well as bacterial baths acting like thermal baths. These systems are micron-sized and are subjected to large thermal fluctuations. Hence, for these systems average thermodynamic quantities, such as work done, heat exchanged, and efficiency, lose meaning unless otherwise supported by their full probability distributions. Earlier studies on microengines are concerned with applying Carnot or Stirling engine protocols to miniaturized systems, where system undergoes typical two isothermal and two adiabatic changes. Unlike these models we study a prototype system of two classical Ising spins driven by time-dependent, phase-different, external magnetic fields. These spins are simultaneously in contact with two heat reservoirs at different temperatures for the full duration of the driving protocol. Performance of the model as an engine or a refrigerator depends only on a single parameter, namely the phase between two external drivings. We study this system in terms of fluctuations in efficiency and coefficient of performance (COP). We find full distributions of these quantities numerically and study the tails of these distributions. We also study reliability of the engine. We find the fluctuations dominate mean values of efficiency and COP, and their probability distributions are broad with power law tails.

Two coupled, driven Ising spin systems working as an engine

NASA Astrophysics Data System (ADS)

Basu, Debarshi; Nandi, Joydip; Jayannavar, A. M.; Marathe, Rahul

2017-05-01

Miniaturized heat engines constitute a fascinating field of current research. Many theoretical and experimental studies are being conducted that involve colloidal particles in harmonic traps as well as bacterial baths acting like thermal baths. These systems are micron-sized and are subjected to large thermal fluctuations. Hence, for these systems average thermodynamic quantities, such as work done, heat exchanged, and efficiency, lose meaning unless otherwise supported by their full probability distributions. Earlier studies on microengines are concerned with applying Carnot or Stirling engine protocols to miniaturized systems, where system undergoes typical two isothermal and two adiabatic changes. Unlike these models we study a prototype system of two classical Ising spins driven by time-dependent, phase-different, external magnetic fields. These spins are simultaneously in contact with two heat reservoirs at different temperatures for the full duration of the driving protocol. Performance of the model as an engine or a refrigerator depends only on a single parameter, namely the phase between two external drivings. We study this system in terms of fluctuations in efficiency and coefficient of performance (COP). We find full distributions of these quantities numerically and study the tails of these distributions. We also study reliability of the engine. We find the fluctuations dominate mean values of efficiency and COP, and their probability distributions are broad with power law tails.

Reviewed approach to defining the Active Interlock Envelope for Front End ray tracing

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

Seletskiy, S.; Shaftan, T.

To protect the NSLS-II Storage Ring (SR) components from damage from synchrotron radiation produced by insertion devices (IDs) the Active Interlock (AI) keeps electron beam within some safe envelope (a.k.a Active Interlock Envelope or AIE) in the transverse phase space. The beamline Front Ends (FEs) are designed under assumption that above certain beam current (typically 2 mA) the ID synchrotron radiation (IDSR) fan is produced by the interlocked e-beam. These assumptions also define how the ray tracing for FE is done. To simplify the FE ray tracing for typical uncanted ID it was decided to provide the Mechanical Engineering groupmore » with a single set of numbers (x,x’,y,y’) for the AIE at the center of the long (or short) ID straight section. Such unified approach to the design of the beamline Front Ends will accelerate the design process and save valuable human resources. In this paper we describe our new approach to defining the AI envelope and provide the resulting numbers required for design of the typical Front End.« less

Data driven propulsion system weight prediction model

NASA Astrophysics Data System (ADS)

Gerth, Richard J.

1994-10-01

The objective of the research was to develop a method to predict the weight of paper engines, i.e., engines that are in the early stages of development. The impetus for the project was the Single Stage To Orbit (SSTO) project, where engineers need to evaluate alternative engine designs. Since the SSTO is a performance driven project the performance models for alternative designs were well understood. The next tradeoff is weight. Since it is known that engine weight varies with thrust levels, a model is required that would allow discrimination between engines that produce the same thrust. Above all, the model had to be rooted in data with assumptions that could be justified based on the data. The general approach was to collect data on as many existing engines as possible and build a statistical model of the engines weight as a function of various component performance parameters. This was considered a reasonable level to begin the project because the data would be readily available, and it would be at the level of most paper engines, prior to detailed component design.

Modeling Heat Loss through Piston and Effects of Thermal Boundary Coatings in Diesel Engine Simulations using Conjugate Heat Transfer models

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

Kundu, Prithwish; Scarcelli, Riccardo; Som, Sibendu

Heat loss through wall boundaries play a dominant role in the overall performance and efficiency of internal combustion engines. Typical engine simulations use constant temperature wall boundary conditions. These boundary conditions cannot be estimated accurately from experiments due to the complexities involved with engine combustion. As a result they introduce a large uncertainty in engine simulations and serve as a tuning parameter. Modeling the process of heat transfer through the solid walls in an unsteady engine computational fluid dynamics (CFD) simulation can lead to the development of higher fidelity engine calculations. These models can be used to study the impactmore » of heat loss on engine efficiency and explore new design methodologies that can reduce heat losses. In this work, a single cylinder diesel engine is modeled along with the solid piston coupled to the fluid domain. Conjugate heat transfer (CHT) modeling techniques were implemented to model heat losses for a full cycle of a Navistar diesel engine. This CFD model is then validated against experimental data available from thermocouples embedded inside the piston surface. The overall predictions from the model match closely with the experimental observations. The validated model is further used to explore the benefits of thermal barrier coatings (TBC) on piston bowls. The effect of TBC coatings were modeled as a thermal resistance in the heat transfer models. Full cycle 3D engine simulations provide quantitative insights into heat loss and thus calculate the efficiency gain by the use of TBC coatings. The work establishes a validated modeling framework for CHT modeling in reciprocating engine simulations.« less

Direct Single-Enzyme Biomineralization of Catalytically Active Ceria and Ceria–Zirconia Nanocrystals

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

Curran, Christopher D.; Lu, Li; Jia, Yue

Biomineralization is an intriguing approach to the synthesis of functional inorganic materials for energy applications whereby biological systems are engineered to mineralize inorganic materials and control their structure over multiple length scales under mild reaction conditions. Herein we demonstrate a single-enzyme-mediated biomineralization route to synthesize crystalline, catalytically active, quantum-confined ceria (CeO2–x) and ceria–zirconia (Ce1–yZryO2–x) nanocrystals for application as environmental catalysts. In contrast to typical anthropogenic synthesis routes, the crystalline oxide nanoparticles are formed at room temperature from an otherwise inert aqueous solution without the addition of a precipitant or additional reactant. An engineered form of silicatein, rCeSi, as a singlemore » enzyme not only catalyzes the direct biomineralization of the nanocrystalline oxides but also serves as a templating agent to control their morphological structure. The biomineralized nanocrystals of less than 3 nm in diameter are catalytically active toward carbon monoxide oxidation following an oxidative annealing step to remove carbonaceous residue. The introduction of zirconia into the nanocrystals leads to an increase in Ce(III) concentration, associated catalytic activity, and the thermal stability of the nanocrystals.« less

Periodic and rational solutions of the reduced Maxwell-Bloch equations

NASA Astrophysics Data System (ADS)

Wei, Jiao; Wang, Xin; Geng, Xianguo

2018-06-01

We investigate the reduced Maxwell-Bloch (RMB) equations which describe the propagation of short optical pulses in dielectric materials with resonant non-degenerate transitions. The general Nth-order periodic solutions are provided by means of the Darboux transformation. The Nth-order degenerate periodic and Nth-order rational solutions containing several free parameters with compact determinant representations are derived from two different limiting cases of the obtained general periodic solutions, respectively. Explicit expressions of these solutions from first to second order are presented. Typical nonlinear wave patterns for the four components of the RMB equations such as single-peak, double-peak-double-dip, double-peak and single-dip structures in the second-order rational solutions are shown. This kind of the rational solutions correspond to rogue waves in the reduced Maxwell-Bloch equations.

Recognition of voice commands using adaptation of foreign language speech recognizer via selection of phonetic transcriptions

NASA Astrophysics Data System (ADS)

Maskeliunas, Rytis; Rudzionis, Vytautas

2011-06-01

In recent years various commercial speech recognizers have become available. These recognizers provide the possibility to develop applications incorporating various speech recognition techniques easily and quickly. All of these commercial recognizers are typically targeted to widely spoken languages having large market potential; however, it may be possible to adapt available commercial recognizers for use in environments where less widely spoken languages are used. Since most commercial recognition engines are closed systems the single avenue for the adaptation is to try set ways for the selection of proper phonetic transcription methods between the two languages. This paper deals with the methods to find the phonetic transcriptions for Lithuanian voice commands to be recognized using English speech engines. The experimental evaluation showed that it is possible to find phonetic transcriptions that will enable the recognition of Lithuanian voice commands with recognition accuracy of over 90%.

Performance and safety aspects of the XV-15 tilt rotor research aircraft

NASA Technical Reports Server (NTRS)

Wernicke, K. G.

1977-01-01

Aircraft performance is presented illustrating the flexibility and capability of the XV-15 to conduct its planned proof-of-concept flight research in the areas of dynamics, stability and control, and aerodynamics. Additionally, the aircraft will demonstrate mission-type performance typical of future operational aircraft. The aircraft design is described and discussed with emphasis on the safety and fail-operate features of the aircraft and its systems. Two or more levels of redundancy are provided in the dc and ac electrical systems, hydraulics, conversion, flaps, landing gear extension, SCAS, and force-feel. RPM is maintained by a hydro-electrical blade pitch governor that consists of a primary and standby governor with a cockpit wheel control for manual backup. The two engines are interconnected for operation on a single engine. In the event of total loss of power, the aircraft can enter autorotation starting from the airplane as well as the helicopter mode of flight.

Characterization of typical platelet injector flow configurations. [liquid propellant rocket engines

NASA Technical Reports Server (NTRS)

Hickox, C. E.

1975-01-01

A study to investigate the hydraulic atomization characteristics of several novel injector designs for use in liquid propellant rocket engines is presented. The injectors were manufactured from a series of thin stainless steel platelets through which orifices were very accurately formed by a photoetching process. These individual platelets were stacked together and the orifices aligned so as to produce flow passages of prescribed geometry. After alignment, the platelets were bonded into a single, 'platelet injector', unit by a diffusion bonding process. Because of the complex nature of the flow associated with platelet injectors, it was necessary to use experimental techniques, exclusively, throughout the study. Large scale models of the injectors were constructed from aluminum plates and the appropriate fluids were modeled using a glycerol-water solution. Stop-action photographs of test configurations, using spark-shadowgraph or stroboscopic back-lighting, are shown.

Ceramic Bearings For Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.

1989-01-01

Report reviews data from three decades of research on bearings containing rolling elements and possibly other components made of ceramics. Ceramic bearings attractive for use in gas-turbine engines because ceramics generally retain strengths and resistances to corrosion over range of temperatures greater than typical steels used in rolling-element bearings. Text begins with brief description of historical developments in field. Followed by discussion of effects of contact stress on fatigue life of rolling element. Supplemented by figures and tables giving data on fatigue lives of rolling elements made of various materials. Analyzes data on effects of temperature and speed on fatigue lives for several materials and operating conditions. Followed by discussion of related topic of generation of heat in bearings, with consideration of effects of bearing materials, lubrication, speeds, and loads.

Micro- and nanodevices integrated with biomolecular probes

PubMed Central

Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A.

2016-01-01

Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. PMID:26363089

Single-cylinder diesel engine study of four vegetable oils

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

Jacobus, M.J.; Geyer, S.M.; Lestz, S.S.

A single-cylinder, 0.36l, D.I. Diesel engine was operated on Diesel fuel, sunflowerseed oil, cottonseed oil, soybean oil, and peanut oil. The purpose of this study was to provide a detailed comparison of performance and emissions data and to characterize the biological activity of the particulate soluble organic fraction for each fuel using the Ames Salmonella typhimurium test. In addition, exhaust gas aldehyde samples were collected using the DNPH method. These samples were analyzed gravimetrically and separated into components from formaldehyde to heptaldehyde with a gas chromatograph. Results comparing the vegetable oils to Diesel fuel generally show slight improvements in thermalmore » efficiency and indicated specific energy consumption; equal or higher gas-phase emissions; lower indicated specific revertant emissions; and significantly higher aldehyde emissions, including an increased percentage of formaldehyde.« less

Computer-Aided Thermohydraulic Design of TEMA Type E Shell and Tube Heat Exchangers for Use in Low Pressure, Liquid-to-Liquid, Single Phase Applications.

DTIC Science & Technology

1985-04-01

and Standards .. ... ....... ....... 9 A. General . ... .. .. ... ..... .. .. ... 9 B. ASME Boiler and Pressure Vessel Code .. .. ......9 C. Foreign...several different sources. B. American Society of Mechanial Engineers (ASME) Boiler and Pressure Vessel Code A shell and tube heat exchanger is indeed a

Applied group theory applications in the engineering (physical, chemical, and medical), biological, social, and behavioral sciences and in the fine arts

NASA Technical Reports Server (NTRS)

Borg, S. F.

1976-01-01

A generalized applied group theory is developed, and it is shown that phenomena from a number of diverse disciplines may be included under the umbrella of a single theoretical formulation based upon the concept of a group consistent with the usual definition of this term.

New Tools Being Developed for Engine- Airframe Blade-Out Structural Simulations

NASA Technical Reports Server (NTRS)

Lawrence, Charles

2003-01-01

One of the primary concerns of aircraft structure designers is the accurate simulation of the blade-out event. This is required for the aircraft to pass Federal Aviation Administration (FAA) certification and to ensure that the aircraft is safe for operation. Typically, the most severe blade-out occurs when a first-stage fan blade in a high-bypass gas turbine engine is released. Structural loading results from both the impact of the blade onto the containment ring and the subsequent instantaneous unbalance of the rotating components. Reliable simulations of blade-out are required to ensure structural integrity during flight as well as to guarantee successful blade-out certification testing. The loads generated by these analyses are critical to the design teams for several components of the airplane structures including the engine, nacelle, strut, and wing, as well as the aircraft fuselage. Currently, a collection of simulation tools is used for aircraft structural design. Detailed high-fidelity simulation tools are used to capture the structural loads resulting from blade loss, and then these loads are used as input into an overall system model that includes complete structural models of both the engines and the airframe. The detailed simulation (shown in the figure) includes the time-dependent trajectory of the lost blade and its interactions with the containment structure, and the system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes are typically used, and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine s turbomachinery. To develop and validate these new tools with test data, the NASA Glenn Research Center has teamed with GE Aircraft Engines, Pratt & Whitney, Boeing Commercial Aircraft, Rolls-Royce, and MSC.Software.

Characterizing SI Engine Transient Fuel Consumption in ALPHA

EPA Science Inventory

Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation.

Advancing cognitive engineering methods to support user interface design for electronic health records

PubMed Central

Thyvalikakath, Thankam P.; Dziabiak, Michael P.; Johnson, Raymond; Torres-Urquidy, Miguel Humberto; Acharya, Amit; Yabes, Jonathan; Schleyer, Titus K.

2014-01-01

Background Despite many decades of research on the effective development of clinical systems in medicine, the adoption of health information technology to improve patient care continues to be slow, especially in ambulatory settings. This applies to dentistry as well, a primary care discipline with approximately 137,000 practitioners in the United States. A critical reason for slow adoption is the poor usability of clinical systems, which makes it difficult for providers to navigate through the information and obtain an integrated view of patient data. Objective In this study, we documented the cognitive processes and information management strategies used by dentists during a typical patient examination. The results will inform the design of a novel electronic dental record interface. Methods We conducted a cognitive task analysis (CTA) study to observe ten general dentists (five general dentists and five general dental faculty members, each with more than two years of clinical experience) examining three simulated patient cases using a think-aloud protocol. Results Dentists first reviewed the patient’s demographics, chief complaint, medical history and dental history to determine the general status of the patient. Subsequently, they proceeded to examine the patient’s intraoral status using radiographs, intraoral images, hard tissue and periodontal tissue information. The results also identified dentists’ patterns of navigation through patient’s information and additional information needs during a typical clinician-patient encounter. Conclusion This study reinforced the significance of applying cognitive engineering methods to inform the design of a clinical system. Second, applying CTA to a scenario closely simulating an actual patient encounter helped with capturing participants’ knowledge states and decision-making when diagnosing and treating a patient. The resultant knowledge of dentists’ patterns of information retrieval and review will significantly contribute to designing flexible and task-appropriate information presentation in electronic dental records. PMID:24503391

21. Engine identified as a 'single cylinder vacuum assist engine ...

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

21. Engine identified as a 'single cylinder vacuum assist engine for Tod tandem compound engine' showing compressor. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are given on the mixing of a single row of jets with an isothermal mainstream in a straight duct, to include flow and geometric variations typical of combustion chambers in gas turbine engines. The principal conclusions reached from these experiments were: at constant momentum ratio, variations in density ratio have only a second-order effect on the profiles; a first-order approximation to the mixing of jets with a variable temperature mainstream can be obtained by superimposing the jets-in-an isothermal-crossflow and mainstream profiles; flow area convergence, especially injection-wall convergence, significantly improves the mixing; for opposed rows of jets, with the orifice centerlines in-line, the optimum ratio of orifice spacing to duct height is one half of the optimum value for single side injection at the same momentum ratio; and for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single side injection at the same momentum ratio.

The Measurement of Fuel-Air Ratio by Analysis for the Oxidized Exhaust Gas

NASA Technical Reports Server (NTRS)

Gerrish, Harold C.; Meem, J. Lawrence, Jr.

1943-01-01

An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy fuel Specification No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs for the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124.

The Measurement of Fuel-air Ratio by Analysis of the Oxidized Exhaust Gas

NASA Technical Reports Server (NTRS)

Memm, J. Lawrence, Jr.

1943-01-01

An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy Fuel Specification, No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs or the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124

Breeding of a xylose-fermenting hybrid strain by mating genetically engineered haploid strains derived from industrial Saccharomyces cerevisiae.

PubMed

Inoue, Hiroyuki; Hashimoto, Seitaro; Matsushika, Akinori; Watanabe, Seiya; Sawayama, Shigeki

2014-12-01

The industrial Saccharomyces cerevisiae IR-2 is a promising host strain to genetically engineer xylose-utilizing yeasts for ethanol fermentation from lignocellulosic hydrolysates. Two IR-2-based haploid strains were selected based upon the rate of xylulose fermentation, and hybrids were obtained by mating recombinant haploid strains harboring heterogeneous xylose dehydrogenase (XDH) (wild-type NAD(+)-dependent XDH or engineered NADP(+)-dependent XDH, ARSdR), xylose reductase (XR) and xylulose kinase (XK) genes. ARSdR in the hybrids selected for growth rates on yeast extract-peptone-dextrose (YPD) agar and YP-xylose agar plates typically had a higher activity than NAD(+)-dependent XDH. Furthermore, the xylose-fermenting performance of the hybrid strain SE12 with the same level of heterogeneous XDH activity was similar to that of a recombinant strain of IR-2 harboring a single set of genes, XR/ARSdR/XK. These results suggest not only that the recombinant haploid strains retain the appropriate genetic background of IR-2 for ethanol production from xylose but also that ARSdR is preferable for xylose fermentation.

Piloted Simulation Study of a Dual Thrust-Cutback Procedure for Reducing High-Speed Civil Transport Takeoff Noise Levels

NASA Technical Reports Server (NTRS)

Riley, Donald R.; Glaab, Louis J.; Brandon, Jay M.; Person, Lee H., Jr.; Glaab, Patricia C.

1999-01-01

A piloted simulation study was performed for the purpose of indicating the noise reduction benefits and piloting performance that could occur for a typical 4-engine high-Speed Civil Transport (HSCT) configuration during takeoff when a dual thrust-cutback procedure was employed with throttle operation under direct computer control. Two thrust cutbacks were employed with the first cutback performed while the vehicle was accelerating on the run-way and the second cutback performed at a distance farther downrange. Added vehicle performance improvements included the incorporation of high-lift increments into the aerodynamic database of the vehicle and the use of limited engine oversizing. Four single-stream turbine bypass engines that had no noise suppression of any kind were used with this configuration. This approach permitted establishing the additional noise suppression level that was needed to meet Federal Air Regulation Part 36 Stage 3 noise levels for subsonic commercial jet aircraft. Noise level results were calculated with the jet mixing and shock noise modules of the Aircraft Noise Prediction Program (ANOPP).

On using ethical theories to teach engineering ethics.

PubMed

Bouville, Mathieu

2008-03-01

Many engineering ethics classes and textbooks introduce theories such as utilitarianism and Kantianism (and most others draw from these theories without mentioning them explicitly). Yet using ethical theories to teach engineering ethics is not devoid of difficulty. First, their status is unclear (should one pick a single theory or use them all? does it make a difference?) Also, textbooks generally assume or fallaciously 'prove' that egoism (or even simply accounting for one's interests) is wrong. Further, the drawbacks of ethical theories are underestimated and the theories are also otherwise misrepresented to make them more suitable for engineering ethics as the authors construe it, viz. the 'moral reasoning' process. Stating in what various theories disagree would allow the students to frame the problem more productively in terms of motive-consequence or society-individual dichotomies rather than in terms of Kant-utilitarian.

An overview of the Small Engine Component Technology (SECT) studies

NASA Technical Reports Server (NTRS)

Vanco, M. R.; Wintucky, W. T.; Niedzwiecki, R. W.

1986-01-01

The objectives of the joint NASA/Army SECT Studies were to identify high payoff technologies for year 2000 small gas turbine engine applications and to provide a technology plan for guiding future research and technology efforts applicable to rotorcraft, commuter and general aviation aircraft and cruise missiles. Competitive contracts were awarded to Allison, AVCO Lycoming, Garrett, Teledyne CAE and Williams International. This paper presents an overview of the contractors' study efforts for the commuter, rotorcraft, cruise missile, and auxiliary power (APU) applications with engines in the 250 to 1,000 horsepower size range. Reference aircraft, missions and engines were selected. Advanced engine configurations and cycles with projected year 2000 component technologies were evaluated and compared with a reference engine selected by the contractor. For typical commuter and rotorcraft applications, fuel savings of 22 percent to 42 percent can be attained. For $1/gallon and $2/gallon fuel, reductions in direct operating cost range from 6 percent to 16 percent and from 11 percent to 17 percent respectively. For subsonic strategic cruise missile applications, fuel savings of 38 percent to 54 percent can be achieved which allows 35 percent to 60 percent increase in mission range and life cycle cost reductions of 40 percent to 56 percent. High payoff technologies have been identified for all applications.

20. Engine identified as a 'single cylinder vacuum assist engine ...

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

20. Engine identified as a 'single cylinder vacuum assist engine for the Tod tandem compound engine' showing crank end. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

Segmented ion thruster

NASA Technical Reports Server (NTRS)

Brophy, John R. (Inventor)

1993-01-01

Apparatus and methods for large-area, high-power ion engines comprise dividing a single engine into a combination of smaller discharge chambers (or segments) configured to operate as a single large-area engine. This segmented ion thruster (SIT) approach enables the development of 100-kW class argon ion engines for operation at a specific impulse of 10,000 s. A combination of six 30-cm diameter ion chambers operating as a single engine can process over 100 kW. Such a segmented ion engine can be operated from a single power processor unit.

Final Environmental Impact Statement for the Designation of a Disposal Site for Dredged Material in Western Long Island Sound WLIS III.

DTIC Science & Technology

1982-02-01

sediment environ- ment remains anaerobic . Most metals are bound to the organics, sulfides, and particulates of the sediments and would remain...mentioned in the bathymetric description of the general site area. The currents at the site area are below the threshold velocities that typical silt...8217It4.’it i I Page 2 Army Corps of Engineers Jan. 10, 1982 honestly say that the benefits of marathon swimming are based not only on a feeling of

A tensor approach to modeling of nonhomogeneous nonlinear systems

NASA Technical Reports Server (NTRS)

Yurkovich, S.; Sain, M.

1980-01-01

Model following control methodology plays a key role in numerous application areas. Cases in point include flight control systems and gas turbine engine control systems. Typical uses of such a design strategy involve the determination of nonlinear models which generate requested control and response trajectories for various commands. Linear multivariable techniques provide trim about these motions; and protection logic is added to secure the hardware from excursions beyond the specification range. This paper reports upon experience in developing a general class of such nonlinear models based upon the idea of the algebraic tensor product.

Comparing historical and modern methods of Sea Surface Temperature measurement - Part 1: Review of methods, field comparisons and dataset adjustments

NASA Astrophysics Data System (ADS)

Matthews, J. B. R.

2012-09-01

Sea Surface Temperature (SST) measurements have been obtained from a variety of different platforms, instruments and depths over the post-industrial period. Today most measurements come from ships, moored and drifting buoys and satellites. Shipboard methods include temperature measurement of seawater sampled by bucket and in engine cooling water intakes. Engine intake temperatures are generally thought to average a few tenths of a °C warmer than simultaneous bucket temperatures. Here I review SST measurement methods, studies comparing shipboard methods by field experiment and adjustments applied to SST datasets to account for variable methods. In opposition to contemporary thinking, I find average bucket-intake temperature differences reported from field studies inconclusive. Non-zero average differences often have associated standard deviations that are several times larger than the averages themselves. Further, average differences have been found to vary widely between ships and between cruises on the same ship. The cause of non-zero average differences is typically unclear given the general absence of additional temperature observations to those from buckets and engine intakes. Shipboard measurements appear of variable quality, highly dependent upon the accuracy and precision of the thermometer used and the care of the observer where manually read. Methods are generally poorly documented, with written instructions not necessarily reflecting actual practices of merchant mariners. Measurements cannot be expected to be of high quality where obtained by untrained sailors using thermometers of low accuracy and precision.

Rotary engine performance limits predicted by a zero-dimensional model

NASA Technical Reports Server (NTRS)

Bartrand, Timothy A.; Willis, Edward A.

1992-01-01

A parametric study was performed to determine the performance limits of a rotary combustion engine. This study shows how well increasing the combustion rate, insulating, and turbocharging increase brake power and decrease fuel consumption. Several generalizations can be made from the findings. First, it was shown that the fastest combustion rate is not necessarily the best combustion rate. Second, several engine insulation schemes were employed for a turbocharged engine. Performance improved only for a highly insulated engine. Finally, the variability of turbocompounding and the influence of exhaust port shape were calculated. Rotary engines performance was predicted by an improved zero-dimensional computer model based on a model developed at the Massachusetts Institute of Technology in the 1980's. Independent variables in the study include turbocharging, manifold pressures, wall thermal properties, leakage area, and exhaust port geometry. Additions to the computer programs since its results were last published include turbocharging, manifold modeling, and improved friction power loss calculation. The baseline engine for this study is a single rotor 650 cc direct-injection stratified-charge engine with aluminum housings and a stainless steel rotor. Engine maps are provided for the baseline and turbocharged versions of the engine.

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Technical Reports Server (NTRS)

Monell, Donald W.; Piland, William M.

2000-01-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operation). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographical distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across Agency.

Influence of Science, Technology, and Engineering Curriculum on Rural Midwestern High School Student Career Decisions

NASA Astrophysics Data System (ADS)

Killingsworth, John

Low degree completion in technical and engineering degrees is a growing concern for policymakers and educators in the United States. This study was an examination of the behaviors of adolescents specific to career decisions related to technology and engineering. The central research question for this study was: do rural, Midwestern high school technical and engineering curricula serve to engage students sufficiently to encourage them to persist through high school while sustaining their interests in technology and engineering careers? Engaging students in technology and engineering fields is the challenge for educators throughout the country and the Midwest. Rural schools have the additional challenge of meeting those issues because of resource limitations. Students in three Midwestern schools were surveyed to determine the level of interest in technology and engineering. The generalized likelihood ratio test was used to overcome concerns for small sample sizes. Accounting for dependent variables, multiple independent variables are examined using descriptive statistics to determine which have greater influence on career decisions, specifically those related to technology and engineering. A typical science curriculum is defined for rural Midwestern high schools. This study concludes that such curriculum achieves the goal of maintaining or increasing student interest and engagement in STEM careers. Furthermore, those schools that incorporate contextual and experiential learning activities into the curriculum demonstrate increased results in influencing student career choices toward technology and engineering careers. Implications for parents, educators, and industry professionals are discussed.

Single-ion conducting diblock terpolymers for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Morris, Melody; Epps, Thomas H., III

Block polymer (BP) electrolytes provide an attractive route to overcome the competing constraints of high conductivity and mechanical/thermal stability in lithium-ion batteries through nanoscale self-assembly. For example, macromolecules can be engineered such that one domain conducts lithium ions and the other prevents lithium dendrite formation. Herein, we report on the behavior of a single-ion conducting BP electrolyte that was designed to facilitate the transport of lithium ions. These polymers differ from traditional salt-doped BP electrolytes, which require the addition of a lithium salt to bestow conductivity and typically suffer from substantial counterion motion that reduces efficiency. New single-ion BPs were synthesized, and the nanoscale morphologies were determined using small angle X-ray scattering and transmission electron microscopy. Electrolyte performance was measured using AC impedance spectroscopy and DC polarization, and the results were correlated to nanoscale morphology and ion content. Enhanced physical understanding of single-ion BPs was gained by connecting the ion mobility to the chemistry, chain structure, and ion content of the single-ion BP. These studies can be applied to other charged-neutral block polymers to elucidate the effects of ion content on self-assembly and macroscopic properties.

Quiet engine program flight engine design study

NASA Technical Reports Server (NTRS)

Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

1974-01-01

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

Enhancing non-technical skills by a multidisciplinary engineering summer school

NASA Astrophysics Data System (ADS)

Larsen, Peter Gorm; Kristiansen, Erik Lasse; Bennedsen, Jens; Bjerge, Kim

2017-11-01

In general engineering studies focus on the technical skills in their own discipline. However, in their subsequent industrial careers, a significant portion of their time needs to be devoted to non-technical skills. In addition, in an increasingly globalised world collaboration in teams across cultures and disciplines is paramount to the creation of new and innovative products. In order to enhance the non-technical skills for groups of engineering students a series of innovation courses has been arranged and delivered in close collaboration with an industrial company (Bang & Olufsen). These courses have been organised as summer schools called 'Conceptual Design and Development of Innovative Products' (CD-DIP) and delivered outside the usual educational environment. In order to explore the impact of this single course, we have conducted a study among the students participating from 2007 to 2013. This has been carried out both qualitatively using interviews with selected students as well as quantitatively using a survey. The results are outstanding in demonstrating that the non-technical skills obtained in this single course have been of high value for a large portion of the students' subsequent professional life.

A design strategy for the use of vortex generators to manage inlet-engine distortion using computational fluid dynamics

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Levy, Ralph

1991-01-01

A reduced Navier-Stokes solution technique was successfully used to design vortex generator installations for the purpose of minimizing engine face distortion by restructuring the development of secondary flow that is induced in typical 3-D curved inlet ducts. The results indicate that there exists an optimum axial location for this installation of corotating vortex generators, and within this configuration, there exists a maximum spacing between generator blades above which the engine face distortion increases rapidly. Installed vortex generator performance, as measured by engine face circumferential distortion descriptors, is sensitive to Reynolds number and thereby the generator scale, i.e., the ratio of generator blade height to local boundary layer thickness. Installations of corotating vortex generators work well in terms of minimizing engine face distortion within a limited range of generator scales. Hence, the design of vortex generator installations is a point design, and all other conditions are off design. In general, the loss levels associated with a properly designed vortex generator installation are very small; thus, they represent a very good method to manage engine face distortion. This study also showed that the vortex strength, generator scale, and secondary flow field structure have a complicated and interrelated influence over engine face distortion, over and above the influence of the initial arrangement of generators.

Study of blade aspect ratio on a compressor front stage aerodynamic and mechanical design report

NASA Technical Reports Server (NTRS)

Burger, G. D.; Lee, D.; Snow, D. W.

1979-01-01

A single stage compressor was designed with the intent of demonstrating that, for a tip speed and hub-tip ratio typical of an advanced core compressor front stage, the use of low aspect ratio can permit high levels of blade loading to be achieved at an acceptable level of efficiency. The design pressure ratio is 1.8 at an adiabatic efficiency of 88.5 percent. Both rotor and stator have multiple-circular-arc airfoil sections. Variable IGV and stator vanes permit low speed matching adjustments. The design incorporates an inlet duct representative of an engine transition duct between fan and high pressure compressor.

Study of blade aspect ratio on a compressor front stage

NASA Technical Reports Server (NTRS)

Behlke, R. F.; Brooky, J. D.; Canal, E., Jr.

1980-01-01

A single stage, low aspect ratio, compressor with a 442.0 m/sec (1450 ft/sec) tip speed and a 0.597 hub/tip ratio typical of an advanced core compressor front stage was tested. The test stage incorporated an inlet duct which was representative of an engine transition duct between fan and high pressure compressors. At design speed, the rotor stator stage achieved a peak adiabatic efficiency of 86.6 percent at a flow of 44.35 kg/sec (97.8 lbm/sec) and a pressure ratio of 1.8. Surge margin was 12.5 percent from the peak stage efficiency point.

CFCS and electric chillers: Selection of large-capacity water chillers in the 1990s. Final report

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

Niess, R.C.

1992-03-01

This handbook offers a single source of useful information for understanding CFC and HCFC phaseout issues and selecting large-capacity water chillers for cooling commercial buildings. It evaluates the performance of electric, absorption, and natural-gas-engine driven water chillers. An economic evaluation checklist and example are included, using the EPRI COMTECH screening tool. Peak shaving with gas chillers and load shifting with chilled water storage are examined. The handbook, written for a diverse audience, covers chiller hardware, function, performance, and typical installed costs. It provides guidelines and checklists for chiller selection, economic comparison, and operation and maintenance.

CFCS and electric chillers: Selection of large-capacity water chillers in the 1990s

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

Niess, R.C.

1992-03-01

This handbook offers a single source of useful information for understanding CFC and HCFC phaseout issues and selecting large-capacity water chillers for cooling commercial buildings. It evaluates the performance of electric, absorption, and natural-gas-engine driven water chillers. An economic evaluation checklist and example are included, using the EPRI COMTECH screening tool. Peak shaving with gas chillers and load shifting with chilled water storage are examined. The handbook, written for a diverse audience, covers chiller hardware, function, performance, and typical installed costs. It provides guidelines and checklists for chiller selection, economic comparison, and operation and maintenance.

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines

NASA Technical Reports Server (NTRS)

Halliwell, Ian

2001-01-01

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accomodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part I-Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2-Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25.800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3-Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine, two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5,000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC material in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines

NASA Technical Reports Server (NTRS)

Halliwell, Ian

2001-01-01

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accommodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part 1: Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2: Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25,800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3: Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine. two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5.000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC materials in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Correlation of the Characteristics of Single-Cylinder and Flight Engines in Tests of High-Performance Fuels in an Air-Cooled Engine I : Cooling Characteristics

NASA Technical Reports Server (NTRS)

Wilson, Robert W.; Richard, Paul H.; Brown, Kenneth D.

1945-01-01

Variable charge-air flow, cooling-air pressure drop, and fuel-air ration investigations were conducted to determine the cooling characteristics of a full-scale air-cooled single cylinder on a CUE setup. The data are compared with similar data that were available for the same model multicylinder engine tested in flight in a four-engine airplane. The cylinder-head cooling correlations were the same for both the single-cylinder and the flight engine. The cooling correlations for the barrels differed slightly in that the barrel of the single-cylinder engine runs cooler than the barrel of te flight engine for the same head temperatures and engine conditions.

Factors in the Design of Centrifugal Type Injection Valves for Oil Engines

NASA Technical Reports Server (NTRS)

Joachim, W F; Beardsley, E G

1928-01-01

This research was undertaken in connection with a general study of the application of the fuel injection engine to aircraft. The purpose of the investigation was to determine the effect of four important factors in the design of a centrifugal type automatic injection valve on the penetration, general shape, and distribution of oil sprays. The general method employed was to record the development of single sprays by means of special high-speed photographic apparatus capable of taking 25 consecutive pictures of the moving spray at a rate of 4,000 per second. Investigations were made concerning the effects on spray characteristics, of the helix angle of helical grooves, the ratio of the cross-sectional area of the orifice to that of the grooves, the ratio of orifice length to diameter, and the position of the seat. Maximum spray penetration was obtained with a ratio of orifice length to diameter of about 1.5. Slightly greater penetration was obtained with the seat directly before the orifice.

Acoustic emission characteristics of a single cylinder diesel generator at various loads and with a failing injector

NASA Astrophysics Data System (ADS)

Dykas, Brian; Harris, James

2017-09-01

Acoustic emission sensing techniques have been applied in recent years to dynamic machinery with varying degrees of success in diagnosing various component faults and distinguishing between operating conditions. This work explores basic properties of acoustic emission signals measured on a small single cylinder diesel engine in a laboratory setting. As reported in other works in the open literature, the measured acoustic emission on the engine is mostly continuous mode and individual burst events are generally not readily identifiable. Therefore, the AE are processed into the local (instantaneous) root mean square (rms) value of the signal which is averaged over many cycles to obtain a mean rms AE in the crank angle domain. Crank-resolved spectral representation of the AE is also given but rigorous investigation of the AE spectral qualities is left to future study. Cycle-to-cycle statistical dispersion of the AE signal is considered to highlight highly variable engine processes. Engine speed was held constant but load conditions are varied to investigate AE signal sensitivity to operating condition. Furthermore, during the course of testing the fuel injector developed a fault and acoustic emission signals were captured and several signal attributes were successful in distinguishing this altered condition. The sampling and use of instantaneous rms acoustic emission signal demonstrated promise for non-intrusive and economical change detection of engine injection, combustion and valve events.

19. Engine identified as a single cylinder vacuum assist engine ...

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

19. Engine identified as a single cylinder vacuum assist engine for the Filer and Stowell 15-inch continuous mill. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

Flight investigation of the effects of an outboard wing-leading-edge modification on stall/spin characteristics of a low-wing, single-engine, T-tail light airplane

NASA Technical Reports Server (NTRS)

Stough, H. Paul, III; Dicarlo, Daniel J.; Patton, James M., Jr.

1987-01-01

Flight tests were performed to investigate the change in stall/spin characteristics due to the addition of an outboard wing-leading-edge modification to a four-place, low-wing, single-engine, T-tail, general aviation research airplane. Stalls and attempted spins were performed for various weights, center of gravity positions, power settings, flap deflections, and landing-gear positions. Both stall behavior and wind resistance were improved compared with the baseline airplane. The latter would readily spin for all combinations of power settings, flap deflections, and aileron inputs, but the modified airplane did not spin at idle power or with flaps extended. With maximum power and flaps retracted, the modified airplane did enter spins with abused loadings or for certain combinations of maneuver and control input. The modified airplane tended to spin at a higher angle of attack than the baseline airplane.

40 CFR 1065.125 - Engine intake air.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Engine intake air. 1065.125 Section... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.125 Engine intake air. (a) Use the intake-air system installed on the engine or one that represents a typical in-use configuration. This includes the...

40 CFR 1065.125 - Engine intake air.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Engine intake air. 1065.125 Section... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.125 Engine intake air. (a) Use the intake-air system installed on the engine or one that represents a typical in-use configuration. This includes the...

40 CFR 1065.125 - Engine intake air.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Engine intake air. 1065.125 Section... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.125 Engine intake air. (a) Use the intake-air system installed on the engine or one that represents a typical in-use configuration. This includes the...

An experimental study of gaseous exhaust emissions of diesel engine using blend of natural fatty acid methyl ester

NASA Astrophysics Data System (ADS)

Sudrajad, Agung; Ali, Ismail; Samo, Khalid; Faturachman, Danny

2012-09-01

Vegetable oil form in Natural Fatty Acid Methyl Ester (FAME) has their own advantages: first of all they are available everywhere in the world. Secondly, they are renewable as the vegetables which produce oil seeds can be planted year after year. Thirdly, they are friendly with our environment, as they seldom contain sulphur element in them. This makes vegetable fuel studies become current among the various popular investigations. This study is attempt to optimization of using blend FAME on diesel engine by experimental laboratory. The investigation experimental project is comparison between using blend FAME and base diesel fuel. The engine experiment is conducted with YANMAR TF120M single cylinder four stroke diesel engine set-up at variable engine speed with constant load. The data have been taken at each point of engine speed during the stabilized engine-operating regime. Measurement of emissions parameters at difference engine speed conditions have generally indicated lower in emission NOx, but slightly higher on CO2 emission. The result also shown that the blends FAME are good in fuel consumption and potentially good substitute fuels for diesel engine

PIRIA: a general tool for indexing, search, and retrieval of multimedia content

NASA Astrophysics Data System (ADS)

Joint, Magali; Moellic, Pierre-Alain; Hede, P.; Adam, P.

2004-05-01

The Internet is a continuously expanding source of multimedia content and information. There are many products in development to search, retrieve, and understand multimedia content. But most of the current image search/retrieval engines, rely on a image database manually pre-indexed with keywords. Computers are still powerless to understand the semantic meaning of still or animated image content. Piria (Program for the Indexing and Research of Images by Affinity), the search engine we have developed brings this possibility closer to reality. Piria is a novel search engine that uses the query by example method. A user query is submitted to the system, which then returns a list of images ranked by similarity, obtained by a metric distance that operates on every indexed image signature. These indexed images are compared according to several different classifiers, not only Keywords, but also Form, Color and Texture, taking into account geometric transformations and variance like rotation, symmetry, mirroring, etc. Form - Edges extracted by an efficient segmentation algorithm. Color - Histogram, semantic color segmentation and spatial color relationship. Texture - Texture wavelets and local edge patterns. If required, Piria is also able to fuse results from multiple classifiers with a new classification of index categories: Single Indexer Single Call (SISC), Single Indexer Multiple Call (SIMC), Multiple Indexers Single Call (MISC) or Multiple Indexers Multiple Call (MIMC). Commercial and industrial applications will be explored and discussed as well as current and future development.

Biophysical Stimulation for Engineering Functional Skeletal Muscle.

PubMed

Somers, Sarah M; Spector, Alexander A; DiGirolamo, Douglas J; Grayson, Warren L

2017-08-01

Tissue engineering is a promising therapeutic strategy to regenerate skeletal muscle. However, ex vivo cultivation methods typically result in a low differentiation efficiency of stem cells as well as grafts that resemble the native tissues morphologically, but lack contractile function. The application of biomimetic tensile strain provides a potent stimulus for enhancing myogenic differentiation and engineering functional skeletal muscle grafts. We reviewed integrin-dependent mechanisms that potentially link mechanotransduction pathways to the upregulation of myogenic genes. Yet, gaps in our understanding make it challenging to use these pathways to theoretically determine optimal ex vivo strain regimens. A multitude of strain protocols have been applied to in vitro cultures for the cultivation of myogenic progenitors (adipose- and bone marrow-derived stem cells and satellite cells) and transformed murine myoblasts, C2C12s. Strain regimens are characterized by orientation, amplitude, and time-dependent factors (effective frequency, duration, and the rest period between successive strain cycles). Analysis of published data has identified possible minimum/maximum values for these parameters and suggests that uniaxial strains may be more potent than biaxial strains, possibly because they more closely mimic physiologic strain profiles. The application of these biophysical stimuli for engineering 3D skeletal muscle grafts is nontrivial and typically requires custom-designed bioreactors used in combination with biomaterial scaffolds. Consideration of the physical properties of these scaffolds is critical for effective transmission of the applied strains to encapsulated cells. Taken together, these studies demonstrate that biomimetic tensile strain generally results in improved myogenic outcomes in myogenic progenitors and differentiated myoblasts. However, for 3D systems, the optimization of the strain regimen may require the entire system including cells, biomaterials, and bioreactor, to be considered in tandem.

New photon-counting detectors for single-molecule fluorescence spectroscopy and imaging

PubMed Central

Michalet, X.; Colyer, R. A.; Scalia, G.; Weiss, S.; Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Villa, F.; Guerrieri, F.; Rech, I.; Gulinatti, A.; Tisa, S.; Zappa, F.; Ghioni, M.; Cova, S.

2013-01-01

Solution-based single-molecule fluorescence spectroscopy is a powerful new experimental approach with applications in all fields of natural sciences. Two typical geometries can be used for these experiments: point-like and widefield excitation and detection. In point-like geometries, the basic concept is to excite and collect light from a very small volume (typically femtoliter) and work in a concentration regime resulting in rare burst-like events corresponding to the transit of a single-molecule. Those events are accumulated over time to achieve proper statistical accuracy. Therefore the advantage of extreme sensitivity is somewhat counterbalanced by a very long acquisition time. One way to speed up data acquisition is parallelization. Here we will discuss a general approach to address this issue, using a multispot excitation and detection geometry that can accommodate different types of novel highly-parallel detector arrays. We will illustrate the potential of this approach with fluorescence correlation spectroscopy (FCS) and single-molecule fluorescence measurements. In widefield geometries, the same issues of background reduction and single-molecule concentration apply, but the duration of the experiment is fixed by the time scale of the process studied and the survival time of the fluorescent probe. Temporal resolution on the other hand, is limited by signal-to-noise and/or detector resolution, which calls for new detector concepts. We will briefly present our recent results in this domain. PMID:24729836

New photon-counting detectors for single-molecule fluorescence spectroscopy and imaging.

PubMed

Michalet, X; Colyer, R A; Scalia, G; Weiss, S; Siegmund, Oswald H W; Tremsin, Anton S; Vallerga, John V; Villa, F; Guerrieri, F; Rech, I; Gulinatti, A; Tisa, S; Zappa, F; Ghioni, M; Cova, S

2011-05-13

Solution-based single-molecule fluorescence spectroscopy is a powerful new experimental approach with applications in all fields of natural sciences. Two typical geometries can be used for these experiments: point-like and widefield excitation and detection. In point-like geometries, the basic concept is to excite and collect light from a very small volume (typically femtoliter) and work in a concentration regime resulting in rare burst-like events corresponding to the transit of a single-molecule. Those events are accumulated over time to achieve proper statistical accuracy. Therefore the advantage of extreme sensitivity is somewhat counterbalanced by a very long acquisition time. One way to speed up data acquisition is parallelization. Here we will discuss a general approach to address this issue, using a multispot excitation and detection geometry that can accommodate different types of novel highly-parallel detector arrays. We will illustrate the potential of this approach with fluorescence correlation spectroscopy (FCS) and single-molecule fluorescence measurements. In widefield geometries, the same issues of background reduction and single-molecule concentration apply, but the duration of the experiment is fixed by the time scale of the process studied and the survival time of the fluorescent probe. Temporal resolution on the other hand, is limited by signal-to-noise and/or detector resolution, which calls for new detector concepts. We will briefly present our recent results in this domain.

Modeling thermal stress propagation during hydraulic stimulation of geothermal wells

NASA Astrophysics Data System (ADS)

Jansen, Gunnar; Miller, Stephen A.

2017-04-01

A large fraction of the world's water and energy resources are located in naturally fractured reservoirs within the earth's crust. Depending on the lithology and tectonic history of a formation, fracture networks can range from dense and homogeneous highly fractured networks to single large scale fractures dominating the flow behavior. Understanding the dynamics of such reservoirs in terms of flow and transport is crucial to successful application of engineered geothermal systems (also known as enhanced geothermal systems or EGS) for geothermal energy production in the future. Fractured reservoirs are considered to consist of two distinct separate media, namely the fracture and matrix space respectively. Fractures are generally thin, highly conductive containing only small amounts of fluid, whereas the matrix rock provides high fluid storage but typically has much smaller permeability. Simulation of flow and transport through fractured porous media is challenging due to the high permeability contrast between the fractures and the surrounding rock matrix. However, accurate and efficient simulation of flow through a fracture network is crucial in order to understand, optimize and engineer reservoirs. It has been a research topic for several decades and is still under active research. Accurate fluid flow simulations through field-scale fractured reservoirs are still limited by the power of current computer processing units (CPU). We present an efficient implementation of the embedded discrete fracture model, which is a promising new technique in modeling the behavior of enhanced geothermal systems. An efficient coupling strategy is determined for numerical performance of the model. We provide new insight into the coupled modeling of fluid flow, heat transport of engineered geothermal reservoirs with focus on the thermal stress changes during the stimulation process. We further investigate the interplay of thermal and poro-elastic stress changes in the reservoir. Combined with a analytical formulation for the injection temperatures in the open hole section of a geothermal well, the stress changes induced during the injection period of reservoir development can be studied.

Micro- and nanodevices integrated with biomolecular probes.

PubMed

Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A

2015-12-01

Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. Copyright © 2015 Elsevier Inc. All rights reserved.

Homogeneous freezing of single sulfuric and nitric acid solution drops levitated in an acoustic trap

NASA Astrophysics Data System (ADS)

Diehl, Karoline; Ettner-Mahl, Matthias; Hannemann, Anke; Mitra, Subir K.

2009-10-01

The freezing temperatures of single supercooled drops of binary and ternary sulfuric and nitric acid solutions were measured while varying the acid concentration. An acoustic levitator was used which allows to freely suspend single solution drops in air without electrical charges thereby avoiding any electrical influences which may affect the freezing process. The drops of typically 500 µm in radius were monitored by a video camera during cooling cycles down to - 85 °C to simulate the upper tropospheric and stratospheric temperature range. The present data confirm that liquid solution droplets can be supercooled far below the equilibrium melting point by approximately 35 °C. They follow the general trend of the expected freezing temperatures for homogeneous ice nucleation.

Environmental Engineering Curricula assessment in the global world

NASA Astrophysics Data System (ADS)

Caporali, Enrica; Catelani, Marcantonio; Manfrida, Giampaolo; Valdiserri, Juna

2014-05-01

Environmental engineers are technicians with specific expertise on the sustainability of human presence in the environment. Among other global dilemmas, to the environmental engineers it is often demanded to be able in developing systematic, innovative solutions in order to simultaneously meet water and energy needs, to build resilience to natural and technological disasters, to more accurately gauge and manage countries' greenhouse gas emissions. The general objectives of the Environmental Engineers are to establish actions of environmental sustainability as well as to verify progress toward global goals or international commitments. The globalization of challenges and problems to be faced, leads, in general, to the globalization of the engineering profession. In particular, since the environmental issues are without boundaries, and many and different are the involved professions and the competences, the environmental engineer must have a multidisciplinary and interdisciplinary approach to adequately answer to the demand of technical innovative knowledge at global scale. The environmental engineers, more and more, are involved in international projects were the effective collaboration requires not only the capacity to communicate in a common technical language, but also the assurance of an adequate and common level of technical competences, knowledge and understanding. The Europe-based EUR ACE system, currently operated by ENAEE - European Network for Accreditation of Engineering Education, can represent the proper framework and accreditation system in order to provide a set of measures to assess the quality of engineering degree programmes in Europe and abroad. In the global frame of the knowledge triangle: education-innovation-research, the accreditation and quality assurance of engineering curricula in Europe is discussed with reference to the Environmental engineering curricula, of the 1st and 2nd cycle, based on the European Credit Transfer System and in accordance with the Bologna Process, offered at School of Engineering, University of Firenze. The application of the accreditation model EUR-ACE to the multidisciplinary first cycle degree in Civil, Building and Environmental Engineering and the more specific second cycle degree in Environmental Engineering is discussed. Particularly, the critical issues to guarantee the quality and the status of environmental engineering graduates, in terms of applying knowledge capacities and technical innovative competences are examined. The expected learning outcomes of the quality assessment according the Dublin descriptors or the more engineering focused EUR-ACE skill descriptors, and at local and global scale are analysed. The system for educating engineers in communicating knowledge and understanding, making informed judgments and choices, capacities to lifelong learning is also assessed. The involvement of the professional working world in the definition of goals in skills, of typical expectations of achievements and abilities, and in general in comparing the teaching profile with the actual needs of the technical workforce, is described. With the aim to promote the innovative aspects related with the environmental engineering education, the important role that science and technology could play is also taken into consideration.

Probabilistic modeling of the indoor climates of residential buildings using EnergyPlus

DOE PAGES

Buechler, Elizabeth D.; Pallin, Simon B.; Boudreaux, Philip R.; ...

2017-04-25

The indoor air temperature and relative humidity in residential buildings significantly affect material moisture durability, HVAC system performance, and occupant comfort. Therefore, indoor climate data is generally required to define boundary conditions in numerical models that evaluate envelope durability and equipment performance. However, indoor climate data obtained from field studies is influenced by weather, occupant behavior and internal loads, and is generally unrepresentative of the residential building stock. Likewise, whole-building simulation models typically neglect stochastic variables and yield deterministic results that are applicable to only a single home in a specific climate. The

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Technical Reports Server (NTRS)

Monell, Donald W.; Piland, William M.

1999-01-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g. manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across the Agency.

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Astrophysics Data System (ADS)

Monell, Donald W.; Piland, William M.

2000-07-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often led to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across the Agency.

Systems Simulation of NASA Shooting Star Experiment Using Matlab/Simulink

NASA Technical Reports Server (NTRS)

Reagan, Shawn

1997-01-01

The Shooting Star Experiment (SSE) is an experiment that incorporates advance propulsion technology. This project is being managed by the Marshall Space Flight Center, Huntsville, Alabama. Whenever spacecraft are launched from Low Earth Orbit (LEO), (typically 150 nautical miles) they are powered by a upper propulsive stage utilizing either a solid or liquid propellant engine. A typically mission for a spacecraft utilizing an upper stage would be a transfer from LEO to a Geostationary Orbit (GEO) or an interplanetary mission. These upper stages are heavy and bulky because they must carry propellants to provide sufficient energy to perform the mission. The SSE utilizes the energy of the Sun by focusing this energy by means of a Frensel lens into an engine where hydrogen (or nitrogen) gas is injected. The focusing of the solar energy heats the engine to very high temperatures. When the gas is injected into the hot engine, the gas is expelled at very high velocities. This process is extremely efficient. Because of the efficiency of the SSE type engine, more payload can be carried for a typical mission since the propulsive element is much smaller.

Composite engines for application to a single-stage-to-orbit vehicle

NASA Technical Reports Server (NTRS)

Bendot, J. G.; Brown, P. N.; Piercy, T. G.

1975-01-01

Seven composite engines were designed for application to a reusable single-stage-to-orbit vehicle. The engine designs were variations of the supercharged ejector ramjet engine. The resulting performance, weight, and drawings of each engine form a data base for establishing a potential of this class of composite engine to various missions, including the single-stage-to-orbit application. The impact of advanced technology in the design of the critical fan turbine was established.

A Multidisciplinary Engineering Summer School in an Industrial Setting

ERIC Educational Resources Information Center

Larsen, Peter Gorm; Fernandes, Joao M.; Habel, Jacek; Lehrskov, Hanne; Vos, Richard J. C.; Wallington, Oliver; Zidek, Jan

2009-01-01

Most university-level engineering studies produce technically skilled engineers. However, typically students face several difficulties when working in multidisciplinary teams when they initiate their industrial careers. In a globalised world, it becomes increasingly important that engineers are capable of collaborating across disciplinary…

Feasibility of CO/sub 2/ monitoring to assess air quality in mines using diesel equipment

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

Daniel, J.H. Jr.

1987-01-01

The methodology includes: (1) establishing pollutant to CO/sub 2/ ratios for in-service equipment, (2) estimating pollutant concentrations from the ratios and in-mine CO/sub 2/ measurements, and (3) using an air quality index to combine the pollutants into a single number, which indicates the health hazard associated with the pollutants. For the methodology to be valid, the pollutant to CO/sub 2/ ratios must remain constant if engine operating conditions do not significantly change. However, due to the complex dynamics of the fuel injection system, the fuel-air combustion process, and the engine speed-load governing system, the pollutant to CO/sub 2/ ratios maymore » vary during repetitive, but transient engine speed-and-load operation. These transient effects were investigated. In addition, the influence of changing engine conditions due to engine maladjustment, and a practical means to evaluate engine condition were investigated to advance the methodology. The laboratory investigation determined that CO/sub 2/ is an effective indicator of engine exhaust pollutants. It was shown that the exhaust concentrations of carbon monoxide, carbon dioxide, oxides of nitrogen, hydrocarbons, and particulate matter do not significantly vary among repetitive, but transient engine speed-and-load duty cycles typical of in-service equipment. Based on an air quality index and threshold limit values, particulate matter exhibited the greatest adverse effect on air quality. Particulate mass was separated into volatile (organic soluble fraction) and nonvolatile (insoluble carbon fraction) components. Due to particulate concentrations, the engine operating conditions of overfueling and advanced injector timing had greater adverse effects on air quality than the conditions of retarded injector timing, intake air restriction, and Federal certification specifications.« less

Technology developments for a compound cycle engine

NASA Technical Reports Server (NTRS)

Bobula, George A.; Wintucky, William T.; Castor, J. G.

1988-01-01

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the light weight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hour (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. Results of recent activities in a program to establish the technology base for a CCE are presented. The objective of this program is to research and develop those critical technologies which are necessary for the demonstration of a multicylinder diesel core in the early 1990s. A major accomplishment was the initial screening and identification of a lubricant which has potential for meeting the material wear rate limits of the application. An in-situ wear measurement system also was developed to provide accurate, readily obtainable, real time measurements of ring and liner wear. Wear data, from early single cylinder engine tests, are presented to show correlation of the in-situ measurements and the system's utility in determining parametric wear trends. A plan to demonstrate a compound cycle engine by the mid 1990s is included.

Pet Food Palatability Evaluation: A Review of Standard Assay Techniques and Interpretation of Results with a Primary Focus on Limitations

PubMed Central

Aldrich, Gregory C.; Koppel, Kadri

2015-01-01

Simple Summary Palatability of pet foods is typically measured using a single-bowl or a two-bowl test. While these tests give a general understanding of the liking or preference of one food over another, opportunities exist for further method development. Abstract The pet food industry continues to grow steadily as a result of new innovative products. Quality control and product development tests for pet foods are typically conducted through palatability testing with dogs and cats. Palatability is the measure of intake of a food that indicates acceptance or the measure of preference of one food over another. Pet food palatability is most commonly measured using a single-bowl or a two-bowl assay. While these tests answer some questions about the animals’ perception of the food, there are many limitations as well. This review addresses some of these limitations and indicates opportunities for future research. PMID:26479136

Applying the Theory of Constraints to a Base Civil Engineering Operations Branch

DTIC Science & Technology

1991-09-01

Figure Page 1. Typical Work Order Processing . .......... 7 2. Typical Job Order Processing . .......... 8 3. Typical Simplified In-Service Work Plan for...Customers’ Customer Request Service Planning Unit Production] Control Center Material Control Scheduling CE Shops Figure 1.. Typical Work Order Processing 7

Comparison of High-Speed Operating Characteristics of Size 215 Cylindrical-Roller Bearings as Determined in Turbojet Engine and in Laboratory Test Rig

NASA Technical Reports Server (NTRS)

Macks, E Fred; Nemeth, Zolton N

1952-01-01

A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made by means of a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and the outer-race bearing operating temperatures are computed for the laboratory test rig and the turbojet engine. A method is given that enables the designer to predict the inner- and outer-race turbine roller-bearing temperatures from single curves, regardless of variations in speed, load, oil flow, oil inlet temperature, oil inlet viscosity, oil-jet diameter, or any combination of these parameters.

Does Curriculum Practical Training Affect Engineers' Workplace Outcomes? Evidence from an Engineer Survey in China

ERIC Educational Resources Information Center

Li, Jing; Zhang, Yu; Tsang, Mun; Li, Manli

2015-01-01

With the increasing attention to STEM (Science, Technology, Engineering, and Math), hands-on Curriculum Practical Training (CPT) has been expanding rapidly worldwide as a requirement of the undergraduate engineering education. In China, a typical CPT for undergraduate engineering students requires several weeks of hands-on training in the…

Characterizing SI Engine Transient Fuel Consumption in ...

EPA Pesticide Factsheets

Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation. To present an approach to capture dynamic fuel consumption during engine transients and then implement these identified characteristics in ALPHA.

Noise Certification Predictions for FJX-2-Powered Aircraft Using Analytic Methods

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.

1999-01-01

Williams International Co. is currently developing the 700-pound thrust class FJX-2 turbofan engine for the general Aviation Propulsion Program's Turbine Engine Element. As part of the 1996 NASA-Williams cooperative working agreement, NASA agreed to analytically calculate the noise certification levels of the FJX-2-powered V-Jet II test bed aircraft. Although the V-Jet II is a demonstration aircraft that is unlikely to be produced and certified, the noise results presented here may be considered to be representative of the noise levels of small, general aviation jet aircraft that the FJX-2 would power. A single engine variant of the V-Jet II, the V-Jet I concept airplane, is also considered. Reported in this paper are the analytically predicted FJX-2/V-Jet noise levels appropriate for Federal Aviation Regulation certification. Also reported are FJX-2/V-Jet noise levels using noise metrics appropriate for the propeller-driven aircraft that will be its major market competition, as well as a sensitivity analysis of the certification noise levels to major system uncertainties.

Expanding Metabolic Engineering Algorithms Using Feasible Space and Shadow Price Constraint Modules

PubMed Central

Tervo, Christopher J.; Reed, Jennifer L.

2014-01-01

While numerous computational methods have been developed that use genome-scale models to propose mutants for the purpose of metabolic engineering, they generally compare mutants based on a single criteria (e.g., production rate at a mutant’s maximum growth rate). As such, these approaches remain limited in their ability to include multiple complex engineering constraints. To address this shortcoming, we have developed feasible space and shadow price constraint (FaceCon and ShadowCon) modules that can be added to existing mixed integer linear adaptive evolution metabolic engineering algorithms, such as OptKnock and OptORF. These modules allow strain designs to be identified amongst a set of multiple metabolic engineering algorithm solutions that are capable of high chemical production while also satisfying additional design criteria. We describe the various module implementations and their potential applications to the field of metabolic engineering. We then incorporated these modules into the OptORF metabolic engineering algorithm. Using an Escherichia coli genome-scale model (iJO1366), we generated different strain designs for the anaerobic production of ethanol from glucose, thus demonstrating the tractability and potential utility of these modules in metabolic engineering algorithms. PMID:25478320

Experimental Validation and Combustion Modeling of a JP-8 Surrogate in a Single Cylinder Diesel Engine

DTIC Science & Technology

2014-04-15

SINGLE CYLINDER DIESEL ENGINE Amit Shrestha, Umashankar Joshi, Ziliang Zheng, Tamer Badawy, Naeim A. Henein, Wayne State University, Detroit, MI, USA...13-03-2014 4. TITLE AND SUBTITLE EXPERIMENTAL VALIDATION AND COMBUSTION MODELING OF A JP-8 SURROGATE IN A SINGLE CYLINDER DIESEL ENGINE 5a...INTERNATIONAL UNCLASSIFIED • Validate a two-component JP-8 surrogate in a single cylinder diesel engine. Validation parameters include – Ignition delay

Evolved hexose transporter enhances xylose uptake and glucose/xylose co-utilization in Saccharomyces cerevisiae

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

Reider Apel, Amanda; Ouellet, Mario; Szmidt-Middleton, Heather

Enhancing xylose utilization has been a major focus in Saccharomyces cerevisiae strain-engineering efforts. The incentive for these studies arises from the need to use all sugars in the typical carbon mixtures that comprise standard renewable plant-biomass-based carbon sources. While major advances have been made in developing utilization pathways, the efficient import of five carbon sugars into the cell remains an important bottleneck in this endeavor. Here we use an engineered S. cerevisiae BY4742 strain, containing an established heterologous xylose utilization pathway, and imposed a laboratory evolution regime with xylose as the sole carbon source. We obtained several evolved strains withmore » improved growth phenotypes and evaluated the best candidate using genome resequencing. We observed remarkably few single nucleotide polymorphisms in the evolved strain, among which we confirmed a single amino acid change in the hexose transporter HXT7 coding sequence to be responsible for the evolved phenotype. Lastly, the mutant HXT7(F79S) shows improved xylose uptake rates (Vmax = 186.4 ± 20.1 nmol•min -1•mg -1) that allows the S. cerevisiae strain to show significant growth with xylose as the sole carbon source, as well as partial co-utilization of glucose and xylose in a mixed sugar cultivation.« less

Evolved hexose transporter enhances xylose uptake and glucose/xylose co-utilization in Saccharomyces cerevisiae

DOE PAGES

Reider Apel, Amanda; Ouellet, Mario; Szmidt-Middleton, Heather; ...

2016-01-19

Enhancing xylose utilization has been a major focus in Saccharomyces cerevisiae strain-engineering efforts. The incentive for these studies arises from the need to use all sugars in the typical carbon mixtures that comprise standard renewable plant-biomass-based carbon sources. While major advances have been made in developing utilization pathways, the efficient import of five carbon sugars into the cell remains an important bottleneck in this endeavor. Here we use an engineered S. cerevisiae BY4742 strain, containing an established heterologous xylose utilization pathway, and imposed a laboratory evolution regime with xylose as the sole carbon source. We obtained several evolved strains withmore » improved growth phenotypes and evaluated the best candidate using genome resequencing. We observed remarkably few single nucleotide polymorphisms in the evolved strain, among which we confirmed a single amino acid change in the hexose transporter HXT7 coding sequence to be responsible for the evolved phenotype. Lastly, the mutant HXT7(F79S) shows improved xylose uptake rates (Vmax = 186.4 ± 20.1 nmol•min -1•mg -1) that allows the S. cerevisiae strain to show significant growth with xylose as the sole carbon source, as well as partial co-utilization of glucose and xylose in a mixed sugar cultivation.« less

A Delphi Study of Additive Manufacturing Applicability for United States Air Force Civil Engineer Contingency Operations

DTIC Science & Technology

2015-03-26

10 Table 2. Additive Manufacturing Categories (ASTM International , 2012) ..................... 14 Table 3. Delphi... flexibility in the design and structure of manufactured parts. It also allows for the creation of thousands of possible parts or tools from a single...machine. These benefits of 3 precision and flexibility in design and manufacturing show promising possibilities for addressing the general nature of

Preliminary candidate advanced avionics system for general aviation

NASA Technical Reports Server (NTRS)

Mccalla, T. M.; Grismore, F. L.; Greatline, S. E.; Birkhead, L. M.

1977-01-01

An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered.

Rotary balance data for a single engine general aviation design having a high aspect-ratio canard for an angle-of-attack range of 30 deg to 90 deg

NASA Technical Reports Server (NTRS)

Mulcay, W. J.; Rose, R.

1980-01-01

Aerodynamic characteristics obtained in a helical flow environment utilizing a rotary balance located in the Langley spin tunnel are presented in plotted form. The configurations tested included the basic airplane, various control deflections, two canard locations, and wing leading edge modifications, as well as airplane components.

Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Sowers, T Shane; Liu, Yuan; Owen, A. Karl; Guo, Ten-Huei

2015-01-01

The National Aeronautics and Space Administration (NASA) has developed independent airframe and engine models that have been integrated into a single real-time aircraft simulation for piloted evaluation of propulsion control algorithms. In order to have confidence in the results of these evaluations, the integrated simulation must be validated to demonstrate that its behavior is realistic and that it meets the appropriate Federal Aviation Administration (FAA) certification requirements for aircraft. The paper describes the test procedures and results, demonstrating that the integrated simulation generally meets the FAA requirements and is thus a valid testbed for evaluation of propulsion control modes.

Design Life Level: Quantifying risk in a changing climate

NASA Astrophysics Data System (ADS)

Rootzén, Holger; Katz, Richard W.

2013-09-01

In the past, the concepts of return levels and return periods have been standard and important tools for engineering design. However, these concepts are based on the assumption of a stationary climate and do not apply to a changing climate, whether local or global. In this paper, we propose a refined concept, Design Life Level, which quantifies risk in a nonstationary climate and can serve as the basis for communication. In current practice, typical hydrologic risk management focuses on a standard (e.g., in terms of a high quantile corresponding to the specified probability of failure for a single year). Nevertheless, the basic information needed for engineering design should consist of (i) the design life period (e.g., the next 50 years, say 2015-2064); and (ii) the probability (e.g., 5% chance) of a hazardous event (typically, in the form of the hydrologic variable exceeding a high level) occurring during the design life period. Capturing both of these design characteristics, the Design Life Level is defined as an upper quantile (e.g., 5%) of the distribution of the maximum value of the hydrologic variable (e.g., water level) over the design life period. We relate this concept and variants of it to existing literature and illustrate how they, and some useful complementary plots, may be computed and used. One practically important consideration concerns quantifying the statistical uncertainty in estimating a high quantile under nonstationarity.

ER-2 #809 landing in Kiruna, Sweden after second flight of the SAGE III Ozone Loss and Validation Experiment (SOLVE)

NASA Image and Video Library

2000-01-26

ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, an ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

ER-2 #809 outside Arena Arctica hangar in Kiruna, Sweden prior to the SAGE III Ozone Loss and Validation Experiment (SOLVE)

NASA Image and Video Library

2000-01-24

ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, an ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

ER-2 #809 receives preflight fueling outside Arena Arctica hangar in Kiruna, Sweden prior to the SAGE III Ozone Loss and Validation Experiment (SOLVE)

NASA Image and Video Library

2000-01-24

ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, an ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

ER-2 #809 during fueling for first flight in Kiruna, Sweden prior to the SAGE III Ozone Loss and Validation Experiment (SOLVE)

NASA Image and Video Library

2000-01-24

ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, an ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Lockheed ER-2 #806 high altitude research aircraft in flight

NASA Image and Video Library

1998-11-17

ER-2 tail number 806, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Lockheed ER-2 #809 high altitude research aircraft in flight

NASA Image and Video Library

2001-08-01

ER-2 tail number 809, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Lockheed ER-2C #809 high altitude research aircraft in flight

NASA Image and Video Library

1998-04-29

ER-2C tail number 809, was one of two Airborne Science ER-2Cs used as science platforms by Dryden. The aircraft were platforms for a variety of high-altitude science missions flown over various parts of the world. They were also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2Cs were capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2C missions lasted about six hours with ranges of about 2,200 nautical miles. The aircraft typically flew at altitudes above 65,000 feet. On November 19, 1998, the ER-2C set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft was 63 feet long, with a wingspan of 104 feet. The top of the vertical tail was 16 feet above ground when the aircraft was on the bicycle-type landing gear. Cruising speeds were 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2C.

Lockheed ER-2 #806 high altitude research aircraft during landing

NASA Image and Video Library

1998-12-18

ER-2 tail number 806, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

X-Ray Spectroscopy of Ultra-Thin Oxide/Oxide Heteroepitaxial Films: A Case Study of Single-Nanometer VO2/TiO2.

PubMed

Quackenbush, Nicholas F; Paik, Hanjong; Woicik, Joseph C; Arena, Dario A; Schlom, Darrell G; Piper, Louis F J

2015-08-21

Epitaxial ultra-thin oxide films can support large percent level strains well beyond their bulk counterparts, thereby enabling strain-engineering in oxides that can tailor various phenomena. At these reduced dimensions (typically < 10 nm), contributions from the substrate can dwarf the signal from the epilayer, making it difficult to distinguish the properties of the epilayer from the bulk. This is especially true for oxide on oxide systems. Here, we have employed a combination of hard X-ray photoelectron spectroscopy (HAXPES) and angular soft X-ray absorption spectroscopy (XAS) to study epitaxial VO2/TiO2 (100) films ranging from 7.5 to 1 nm. We observe a low-temperature (300 K) insulating phase with evidence of vanadium-vanadium (V-V) dimers and a high-temperature (400 K) metallic phase absent of V-V dimers irrespective of film thickness. Our results confirm that the metal insulator transition can exist at atomic dimensions and that biaxial strain can still be used to control the temperature of its transition when the interfaces are atomically sharp. More generally, our case study highlights the benefits of using non-destructive XAS and HAXPES to extract out information regarding the interfacial quality of the epilayers and spectroscopic signatures associated with exotic phenomena at these dimensions.

ER-2 #809 in Kiruna, Sweden for the SAGE III Ozone Loss and Validation Experiment (SOLVE) with pilot Dee Porter entry for first flight

NASA Image and Video Library

2000-01-24

ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, an ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Teaching Teachers to Teach Green Engineering

ERIC Educational Resources Information Center

Flynn, Ann Marie; Naraghi, Mohammad H.; Austin, Nicole; Helak, Sean; Manzer, Jarrod

2006-01-01

The work provides guidelines for instructors who wish to incorporate green engineering concepts into a typical non-green engineering course without diluting course content or modifying the course syllabus by identifying 5 critical elements necessary to the successful integration of green engineering concepts into any traditional, design-oriented,…

An overview of the small engine component technology (SECT) studies. [commuter, rotorcraft, cruise missile and auxiliary power applications in year 2000

NASA Technical Reports Server (NTRS)

Vanco, M. R.; Wintucky, W. T.; Niedwiecki, R. W.

1986-01-01

The objectives of the joint NASA/Army SECT studies were to identify high payoff technologies for year 2000 small gas turbine engine applications and to provide a technology plan for guiding future research and technology efforts applicable to rotorcraft, commuter and general aviation aircraft and cruise missiles. Competitive contracts were awarded to Allison, AVCO Lycoming, Garrett, Teledyne CAE and Williams International. This paper presents an overview of the contractors' study efforts for the commuter, rotorcraft, cruise missile, and auxiliary power (APU) applications with engines in the 250 to 1,000 horsepower size range. Reference aircraft, missions and engines were selected. Advanced engine configurations and cycles with projected year 2000 component technologies were evaluated and compared with a reference engine selected by the contractor. For typical commuter and rotorcraft applications, fuel savings of 22 percent to 42 percent can be attained. For $1/gallon and $2/gallon fuel, reductions in direct operating cost range from 6 percent to 16 percent and from 11 percent to 17 percent respectively. For subsonic strategic cruise missile applications, fuel savings of 38 percent to 54 percent can be achieved which allows 35 percent to 60 percent increase in mission range and life cycle cost reductions of 40 percent to 56 percent. High payoff technologies have been identified for all applications.

Exhaust-stack nozzle area and shape for individual cylinder exhaust-gas jet-propulsion system

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Turner, Richard; Voss, Fred; Humble, Leroy V

1943-01-01

This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.

NASA-JPL overview, space technology and relevance to medicine (Conference Presentation)

NASA Astrophysics Data System (ADS)

van Zyl, Jakob

2017-05-01

There is special synergy between NASA space instruments and medical devices, especially those that may be implanted in the human body. For example, in both cases instruments have to be small, typically have to consume little power and often have to operate in harsh environments. JPL has a long history in using this synergy to leverage from the technology developed for space missions for application in medical fields. In this talk, we discuss the general overlap of technological requirements in the medical field and space science. We will highlight some examples where JPL instrumentation and engineering has been transferred successfully.

Use of optimization to predict the effect of selected parameters on commuter aircraft performance

NASA Technical Reports Server (NTRS)

Wells, V. L.; Shevell, R. S.

1982-01-01

An optimizing computer program determined the turboprop aircraft with lowest direct operating cost for various sets of cruise speed and field length constraints. External variables included wing area, wing aspect ratio and engine sea level static horsepower; tail sizes, climb speed and cruise altitude were varied within the function evaluation program. Direct operating cost was minimized for a 150 n.mi typical mission. Generally, DOC increased with increasing speed and decreasing field length but not by a large amount. Ride roughness, however, increased considerably as speed became higher and field length became shorter.

Decentralised fixed modes of networked MIMO systems

NASA Astrophysics Data System (ADS)

Hao, Yuqing; Duan, Zhisheng; Chen, Guanrong

2018-04-01

In this paper, decentralised fixed modes (DFMs) of a networked system are studied. The network topology is directed and weighted and the nodes are higher-dimensional linear time-invariant (LTI) dynamical systems. The effects of the network topology, the node-system dynamics, the external control inputs, and the inner interactions on the existence of DFMs for the whole networked system are investigated. A necessary and sufficient condition for networked multi-input/multi-output (MIMO) systems in a general topology to possess no DFMs is derived. For networked single-input/single-output (SISO) LTI systems in general as well as some typical topologies, some specific conditions for having no DFMs are established. It is shown that the existence of DFMs is an integrated result of the aforementioned relevant factors which cannot be decoupled into individual DFMs of the node-systems and the properties solely determined by the network topology.

Development of Integrated Programs for Aerospace-vehicle design (IPAD): Integrated information processing requirements

NASA Technical Reports Server (NTRS)

Southall, J. W.

1979-01-01

The engineering-specified requirements for integrated information processing by means of the Integrated Programs for Aerospace-Vehicle Design (IPAD) system are presented. A data model is described and is based on the design process of a typical aerospace vehicle. General data management requirements are specified for data storage, retrieval, generation, communication, and maintenance. Information management requirements are specified for a two-component data model. In the general portion, data sets are managed as entities, and in the specific portion, data elements and the relationships between elements are managed by the system, allowing user access to individual elements for the purpose of query. Computer program management requirements are specified for support of a computer program library, control of computer programs, and installation of computer programs into IPAD.

Implementation of Finite Volume based Navier Stokes Algorithm Within General Purpose Flow Network Code

NASA Technical Reports Server (NTRS)

Schallhorn, Paul; Majumdar, Alok

2012-01-01

This paper describes a finite volume based numerical algorithm that allows multi-dimensional computation of fluid flow within a system level network flow analysis. There are several thermo-fluid engineering problems where higher fidelity solutions are needed that are not within the capacity of system level codes. The proposed algorithm will allow NASA's Generalized Fluid System Simulation Program (GFSSP) to perform multi-dimensional flow calculation within the framework of GFSSP s typical system level flow network consisting of fluid nodes and branches. The paper presents several classical two-dimensional fluid dynamics problems that have been solved by GFSSP's multi-dimensional flow solver. The numerical solutions are compared with the analytical and benchmark solution of Poiseulle, Couette and flow in a driven cavity.

Report of the Polymer Core Course Committee: Polymer Principles for the Chemical Engineering Curriculum.

ERIC Educational Resources Information Center

Journal of Chemical Education, 1985

1985-01-01

Offers suggestions for introducing polymer topics into: (1) introductory chemical engineering; (2) transport phenomena and unit operations; (3) chemical engineering thermodynamics; and (4) reaction engineering. Also included for each area are examples of textbooks in current use and a few typical problems. (JN)

Experiential Engineering through iGEM--An Undergraduate Summer Competition in Synthetic Biology

ERIC Educational Resources Information Center

Mitchell, Rudolph; Dori, Yehudit Judy; Kuldell, Natalie H.

2011-01-01

Unlike students in other engineering disciplines, undergraduates in biological engineering typically have limited opportunity to develop design competencies, and even fewer chances to implement their designed projects. The international Genetically Engineered Machines (iGEM) competition is a student Synthetic Biology competition that, in 2009,…

Real-time analysis of organic compounds in ship engine aerosol emissions using resonance-enhanced multiphoton ionisation and proton transfer mass spectrometry.

PubMed

Radischat, Christian; Sippula, Olli; Stengel, Benjamin; Klingbeil, Sophie; Sklorz, Martin; Rabe, Rom; Streibel, Thorsten; Harndorf, Horst; Zimmermann, Ralf

2015-08-01

Organic combustion aerosols from a marine medium-speed diesel engine, capable to run on distillate (diesel fuel) and residual fuels (heavy fuel oil), were investigated under various operating conditions and engine parameters. The online chemical characterisation of the organic components was conducted using a resonance-enhanced multiphoton ionisation time-of-flight mass spectrometer (REMPI TOF MS) and a proton transfer reaction-quadrupole mass spectrometer (PTR-QMS). Oxygenated species, alkenes and aromatic hydrocarbons were characterised. Especially the aromatic hydrocarbons and their alkylated derivatives were very prominent in the exhaust of both fuels. Emission factors of known health-hazardous compounds (e.g. mono- and poly-aromatic hydrocarbons) were calculated and found in higher amounts for heavy fuel oil (HFO) at typical engine loadings. Lower engine loads lead in general to increasing emissions for both fuels for almost every compound, e.g. naphthalene emissions varied for diesel fuel exhaust between 0.7 mg/kWh (75 % engine load, late start of injection (SOI)) and 11.8 mg/kWh (10 % engine load, late SOI) and for HFO exhaust between 3.3 and 60.5 mg/kWh, respectively. Both used mass spectrometric techniques showed that they are particularly suitable methods for online monitoring of combustion compounds and very helpful for the characterisation of health-relevant substances. Graphical abstract Three-dimensional REMPI data of organic species in diesel fuel and heavy fuel oil exhaust.

High Altitude Launch for a Practical SSTO

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Denis, Vincent; Lyons, Valerie (Technical Monitor)

2003-01-01

Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31% increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

High Altitude Launch for a Practical SSTO

NASA Astrophysics Data System (ADS)

Landis, Geoffrey A.; Denis, Vincent

2003-01-01

Existing engineering materials allow the constuction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31% increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

Emittance and absorptance of the National Aeronautics and Space Administration ceramic thermal barrier coating. [for gas turbine engine components

NASA Technical Reports Server (NTRS)

Liebert, C. H.

1978-01-01

The spectral emittance of a NASA developed zirconia ceramic thermal barrier coating system, consisting of a metal substrate, a layer of Ni-Cr-Al-Y bond material and a layer of yttria-stabilized zirconia ceramic material, is analyzed. The emittance, needed for evaluation of radiant heat loads on cooled coated gas turbine components, was measured over a range of temperatures that would be typical of its use on such components. Emittance data were obtained with a spectrometer, a reflectometer and a radiation pyrometer at a single bond coating thickness of 0.010 cm and at a ceramic coating thickness of 0-0.076 cm. The data were transformed into the hemispherical total emittance and were correlated to the ceramic coating thickness and temperature using multiple-regression curve-fitting techniques. The system was found to be highly reflective, and, consequently, capable of significantly reducing radiation heat loads on cooled gas turbine engine components.

Communication skills to develop trusting relationships on global virtual engineering capstone teams

NASA Astrophysics Data System (ADS)

Zaugg, Holt; Davies, Randall S.

2013-05-01

As universities seek to provide cost-effective, cross-cultural experiences using global virtual (GV) teams, the 'soft' communication skills typical of all teams, increases in importance for GV teams. Students need to be taught how to navigate through cultural issues and virtual tool issues to build strong trusting relationships with distant team members. Weekly team meetings provide an excellent opportunity to observe key team interactions that facilitate relationship and trust-building among team members. This study observed the weekly team meetings of engineering students attending two US universities and one Asian university as they collaborated as a single GV capstone GV team. In addition local team members were interviewed individually and collectively throughout the project to determine strategies that facilitated team relations and trust. Findings indicate the importance of student choice of virtual communication tools, the refining of communication practices, and specific actions to build trusting relationships. As student developed these attributes, collaboration and success was experienced on this GV team.

Structure-Guided Combinatorial Engineering Facilitates Affinity and Specificity Optimization of Anti-CD81 Antibodies.

PubMed

Nelson, Bryce; Adams, Jarrett; Kuglstatter, Andreas; Li, Zhijian; Harris, Seth F; Liu, Yang; Bohini, Sandya; Ma, Han; Klumpp, Klaus; Gao, Junjun; Sidhu, Sachdev S

2018-07-06

Hepatitis C viral infection is the major cause of chronic hepatitis that affects as many as 71 million people worldwide. Rather than target the rapidly shifting viruses and their numerous serotypes, four independent antibodies were made to target the host antigen CD81 and were shown to block hepatitis C viral entry. The single-chain variable fragment of each antibody was crystallized in complex with the CD81 large extracellular loop in order to guide affinity maturation of two distinct antibodies by phage display. Affinity maturation of antibodies using phage display has proven to be critical to therapeutic antibody development and typically involves modification of the paratope for increased affinity, improved specificity, enhanced stability or a combination of these traits. One antibody was engineered for increased affinity for human CD81 large extracellular loop that equated to increased efficacy, while the second antibody was engineered for cross-reactivity with cynomolgus CD81 to facilitate animal model testing. The use of structures to guide affinity maturation library design demonstrates the utility of combining structural analysis with phage display technologies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prediction of Petermann I and II Spot Sizes for Single-mode Dispersion-shifted and Dispersion-flattened Fibers by a Simple Technique

NASA Astrophysics Data System (ADS)

Kamila, Kiranmay; Panda, Anup Kumar; Gangopadhyay, Sankar

2013-09-01

Employing the series expression for the fundamental modal field of dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers, we present simple but accurate analytical expressions for Petermann I and II spot sizes of such kind of fibers. Choosing some typical dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers as examples, we show that our estimations match excellently with the exact numerical results. The evaluation of the concerned propagation parameters by our formalism needs very little computations. This accurate but simple formalism will benefit the system engineers working in the field of all optical technology.

Aerospace Threaded Fastener Strength in Combined Shear and Tension Loading

NASA Technical Reports Server (NTRS)

Steeve, B. E.; Wingate, R. J.

2012-01-01

A test program was initiated by Marshall Space Flight Center and sponsored by the NASA Engineering and Safety Center to characterize the failure behavior of a typical high-strength aerospace threaded fastener under a range of shear to tension loading ratios for both a nut and an insert configuration where the shear plane passes through the body and threads, respectively. The testing was performed with a customized test fixture designed to test a bolt with a single shear plane at a discrete range of loading angles. The results provide data to compare against existing combined loading failure criteria and to quantify the bolt strength when the shear plane passes through the threads.

Engineering of the function of diamond-like carbon binding peptides through structural design.

PubMed

Gabryelczyk, Bartosz; Szilvay, Géza R; Singh, Vivek K; Mikkilä, Joona; Kostiainen, Mauri A; Koskinen, Jari; Linder, Markus B

2015-02-09

The use of phage display to select material-specific peptides provides a general route towards modification and functionalization of surfaces and interfaces. However, a rational structural engineering of the peptides for optimal affinity is typically not feasible because of insufficient structure-function understanding. Here, we investigate the influence of multivalency of diamond-like carbon (DLC) binding peptides on binding characteristics. We show that facile linking of peptides together using different lengths of spacers and multivalency leads to a tuning of affinity and kinetics. Notably, increased length of spacers in divalent systems led to significantly increased affinities. Making multimers influenced also kinetic aspects of surface competition. Additionally, the multivalent peptides were applied as surface functionalization components for a colloidal form of DLC. The work suggests the use of a set of linking systems to screen parameters for functional optimization of selected material-specific peptides.

Classification of Valleytronics in Thermoelectricity

PubMed Central

Norouzzadeh, Payam; Vashaee, Daryoosh

2016-01-01

The theory of valleytronics as a material design tool for engineering both thermal and electrical transport properties is presented. It is shown that the interplay among the valleytronics parameters such as the degeneracy of the band, intervalley transitions, effective mass, scattering exponent, and the Fermi energy may deteriorate or ameliorate any or all of the main thermoelectric properties. A flowchart classifying the different paths through which the valleytronics can influence the thermoelectric figure-of-merit ZT is derived and discussed in detail. To exemplify the application of the flowchart, valleytronics in four different semiconductors, Mg2Si, Si0.8Ge0.2, AlxGa1−xAs and clathrate Si46-VIII were studied, which showed different trends. Therefore, a degenerate multivalley bandstructure, which is typically anticipated for a good thermoelectric material, cannot be a general design rule for ZT enhancement and a detailed transport study is required to engineer the optimum bandstructure. PMID:26972331

Liquid Propulsion: Propellant Feed System Design. Chapter 2.3.11

NASA Technical Reports Server (NTRS)

Cannon, James L.

2010-01-01

The propellant feed system of a liquid rocket engine determines how the propellants are delivered from the tanks to the thrust chamber. They are generally classified as either pressure fed or pump fed. The pressure-fed system is simple and relies on tank pressures to feed the propellants into the thrust chamber. This type of system is typically used for space propulsion applications and auxiliary propulsion applications requiring low system pressures and small quantities of propellants. In contrast, the pump-fed system is used for high pressure, high performance applications. The selection of one propellant feed system over another is determined based on design trade studies at both the engine and vehicle levels. This chapter first provides a brief overview of the basic configurations of pressure-fed systems. Pump-fed systems are then discussed with greater detail given to the turbomachinery design. Selected design requirements and configurations are provided.

Probing Enzyme-Surface Interactions via Protein Engineering and Single-Molecule Techniques

DTIC Science & Technology

2017-06-26

SECURITY CLASSIFICATION OF: The overall objective of this research was to exploit protein engineering and fluorescence single-molecule methods to... Engineering and Single-Molecule Techniques The views, opinions and/or findings contained in this report are those of the author(s) and should not...Status: Technology Transfer: Report Date: 1 FINAL REPORT Project Title: Probing Enzyme-Surface Interactions via Protein Engineering and

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are presented on the mixing of a single row of jets with an isothermal mainstream in a straight duct, with flow and geometric variations typical of combustion chambers in gas turbine engines included. It is found that at a constant momentum ratio, variations in the density ratio have only a second-order effect on the profiles. A first-order approximation to the mixing of jets with a variable temperature mainstream can, it is found, be obtained by superimposing the jets-in-an-isothermal-crossflow and mainstream profiles. Another finding is that the flow area convergence, especially injection-wall convergence, significantly improves the mixing. For opposed rows of jets with the orifice cone centerlines in-line, the optimum ratio of orifice spacing to duct height is determined to be 1/2 of the optimum value for single injection at the same momentum ratio. For opposed rows of jets with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is found to be twice the optimum value for single side injection at the same momentum ratio.

14 CFR 23.71 - Glide: Single-engine airplanes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Glide: Single-engine airplanes. 23.71... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

14 CFR 121.159 - Single-engine airplanes prohibited.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part. [Doc. No...

14 CFR 23.71 - Glide: Single-engine airplanes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Glide: Single-engine airplanes. 23.71... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

14 CFR 23.71 - Glide: Single-engine airplanes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Glide: Single-engine airplanes. 23.71... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

14 CFR 121.159 - Single-engine airplanes prohibited.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part. [Doc. No...

14 CFR 121.159 - Single-engine airplanes prohibited.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part. [Doc. No...

14 CFR 121.159 - Single-engine airplanes prohibited.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part. [Doc. No...

14 CFR 121.159 - Single-engine airplanes prohibited.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part. [Doc. No...

14 CFR 23.71 - Glide: Single-engine airplanes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Glide: Single-engine airplanes. 23.71 Section 23.71 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

14 CFR 23.71 - Glide: Single-engine airplanes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Glide: Single-engine airplanes. 23.71 Section 23.71 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles...

Sonic IR crack detection of aircraft turbine engine blades with multi-frequency ultrasound excitations

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

Zhang, Ding; Han, Xiaoyan; Newaz, Golam

Effectively and accurately detecting cracks or defects in critical engine components, such as turbine engine blades, is very important for aircraft safety. Sonic Infrared (IR) Imaging is such a technology with great potential for these applications. This technology combines ultrasound excitation and IR imaging to identify cracks and flaws in targets. In general, failure of engine components, such as blades, begins with tiny cracks. Since the attenuation of the ultrasound wave propagation in turbine engine blades is small, the efficiency of crack detection in turbine engine blades can be quite high. The authors at Wayne State University have been developingmore » the technology as a reliable tool for the future field use in aircraft engines and engine parts. One part of the development is to use finite element modeling to assist our understanding of effects of different parameters on crack heating while experimentally hard to achieve. The development has been focused with single frequency ultrasound excitation and some results have been presented in a previous conference. We are currently working on multi-frequency excitation models. The study will provide results and insights of the efficiency of different frequency excitation sources to foster the development of the technology for crack detection in aircraft engine components.« less

Three-Dimensional Printing of Hollow-Struts-Packed Bioceramic Scaffolds for Bone Regeneration.

PubMed

Luo, Yongxiang; Zhai, Dong; Huan, Zhiguang; Zhu, Haibo; Xia, Lunguo; Chang, Jiang; Wu, Chengtie

2015-11-04

Three-dimensional printing technologies have shown distinct advantages to create porous scaffolds with designed macropores for application in bone tissue engineering. However, until now, 3D-printed bioceramic scaffolds only possessing a single type of macropore have been reported. Generally, those scaffolds with a single type of macropore have relatively low porosity and pore surfaces, limited delivery of oxygen and nutrition to surviving cells, and new bone tissue formation in the center of the scaffolds. Therefore, in this work, we present a useful and facile method for preparing hollow-struts-packed (HSP) bioceramic scaffolds with designed macropores and multioriented hollow channels via a modified coaxial 3D printing strategy. The prepared HSP scaffolds combined high porosity and surface area with impressive mechanical strength. The unique hollow-struts structures of bioceramic scaffolds significantly improved cell attachment and proliferation and further promoted formation of new bone tissue in the center of the scaffolds, indicating that HSP ceramic scaffolds can be used for regeneration of large bone defects. In addition, the strategy can be used to prepare other HSP ceramic scaffolds, indicating a universal application for tissue engineering, mechanical engineering, catalysis, and environmental materials.

A Physics-Based Engineering Methodology for Calculating Soft Error Rates of Bulk CMOS and SiGe Heterojunction Bipolar Transistor Integrated Circuits

NASA Astrophysics Data System (ADS)

Fulkerson, David E.

2010-02-01

This paper describes a new methodology for characterizing the electrical behavior and soft error rate (SER) of CMOS and SiGe HBT integrated circuits that are struck by ions. A typical engineering design problem is to calculate the SER of a critical path that commonly includes several circuits such as an input buffer, several logic gates, logic storage, clock tree circuitry, and an output buffer. Using multiple 3D TCAD simulations to solve this problem is too costly and time-consuming for general engineering use. The new and simple methodology handles the problem with ease by simple SPICE simulations. The methodology accurately predicts the measured threshold linear energy transfer (LET) of a bulk CMOS SRAM. It solves for circuit currents and voltage spikes that are close to those predicted by expensive 3D TCAD simulations. It accurately predicts the measured event cross-section vs. LET curve of an experimental SiGe HBT flip-flop. The experimental cross section vs. frequency behavior and other subtle effects are also accurately predicted.

Simulation of Aircraft Engine Blade-Out Structural Dynamics

NASA Technical Reports Server (NTRS)

Lawrence, Charles; Carney, Kelly; Gallardo, Vicente

2001-01-01

A primary concern of aircraft structure designers is the accurate simulation of the blade-out event and the subsequent windmilling of the engine. Reliable simulations of the blade-out event are required to insure structural integrity during flight as well as to guarantee successful blade-out certification testing. The system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes such as MSC NASTRAN are typically used and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine's turbomachinery. The present study provides the equations of motion for rotordynamic response including the effect of spooldown speed and rotor unbalance and examines the effects of these terms on a cantilevered rotor. The effect of spooldown speed is found to be greater with increasing spooldown rate. The parametric term resulting from the mass unbalance has a more significant effect on the rotordynamic response than does the spooldown term. The parametric term affects both the peak amplitudes as well as the resonant frequencies of the rotor.

Simulation of Aircraft Engine Blade-Out Structural Dynamics. Revised

NASA Technical Reports Server (NTRS)

Lawrence, Charles; Carney, Kelly; Gallardo, Vicente

2001-01-01

A primary concern of aircraft structure designers is the accurate simulation of the blade-out event and the subsequent windmilling of the engine. Reliable simulations of the blade-out event are required to insure structural integrity during flight as well as to guarantee successful blade-out certification testing. The system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes such as MSC NASTRAN are typically used and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine's turbomachinery. The present study provides the equations of motion for rotordynamic response including the effect of spooldown speed and rotor unbalance and examines the effects of these terms on a cantilevered rotor. The effect of spooldown speed is found to be greater with increasing spooldown rate. The parametric term resulting from the mass unbalance has a more significant effect on the rotordynamic response than does the spooldown term. The parametric term affects both the peak amplitudes as well as the resonant frequencies of the rotor.

Simulator study of the stall departure characteristics of a light general aviation airplane with and without a wing-leading-edge modification

NASA Technical Reports Server (NTRS)

Riley, D. R.

1985-01-01

A six-degree-of-freedom nonlinear simulation was developed for a two-place, single-engine, low-wing general aviation airplane for the stall and initial departure regions of flight. Two configurations, one with and one without an outboard wing-leading-edge modification, were modeled. The math models developed are presented simulation predictions and flight-test data for validation purposes and simulation results for the two configurations for various maneuvers and power settings are compared to show the beneficial influence of adding the wing-leading-edge modification.

Regulated and non-regulated emissions from in-use diesel-electric switching locomotives.

PubMed

Sawant, Aniket A; Nigam, Abhilash; Miller, J Wayne; Johnson, Kent C; Cocker, David R

2007-09-01

Diesel-electric locomotives are vital to the operation of freight railroads in the United States, and emissions from this source category have generated interest in recent years. They are also gaining attention as an important emission source under the larger set of nonroad sources, both from a regulated emissions and health effects standpoint. The present work analyzes regulated (NOx, PM, THC, CO) and non-regulated emissions from three in-use diesel-electric switching locomotives using standardized sampling and analytical techniques. The engines tested in this work were from 1950, 1960, and 1970 and showed a range of NOx and PM emissions. In general, non-regulated gaseous emissions showed a sharp increase as engines shifted from non-idle to idle operating modes. This is interesting from an emissions perspective since activity data shows that these locomotives spend around 60% of their time idling. In terms of polycyclicaromatic hydrocarbon (PAH) contributions, the dominance of naphthalene and its derivatives over the total PAH emissions was apparent, similar to observations for on-road diesel tractors. Among nonnaphthalenic species, itwas observed that lower molecular weight PAHs and n-alkanes dominated their respective compound classes. Regulated emissions from a newer technology engine used in a back-up generator (BUG) application were also compared againstthe present engines; it was determined that use of the newer engine may lower NOx and PM emissions by up to 30%. Another area of interest to regulators is better estimation of the marine engine inventory for port operations. Toward that end, a comparison of emissions from these engines with engine manufacturer data and the newer technology BUG engine was also performed for a marine duty cycle, another application where these engines are used typically with little modifications.

Experimental Evaluation of a Method for Turbocharging Four-Stroke, Single Cylinder, Internal Combustion Engines

NASA Astrophysics Data System (ADS)

Buchman, Michael; Winter, Amos

2015-11-01

Turbocharging an engine increases specific power, improves fuel economy, reduces emissions, and lowers cost compared to a naturally aspirated engine of the same power output. These advantages make turbocharging commonplace for multi-cylinder engines. Single cylinder engineers are not commonly turbocharged due to the phase lag between the exhaust stroke, which powers the turbocharger, and the intake stroke, when air is pumped into the engine. Our proposed method of turbocharging single cylinder engines is to add an ``air capacitor'' to the intake manifold, an additional volume that acts as a buffer to store compressed air between the exhaust and intake strokes, and smooth out the pressure pulses from the turbocharger. This talk presents experimental results from a single cylinder, turbocharged diesel engine fit with various sized air capacitors. Power output from the engine was measured using a dynamometer made from a generator, with the electrical power dissipated with resistive heating elements. We found that intake air density increases with capacitor size as theoretically predicted, ranging from 40 to 60 percent depending on heat transfer. Our experiment was able to produce 29 percent more power compared to using natural aspiration. These results validated that an air capacitor and turbocharger may be a simple, cost effective means of increasing the power density of single cylinder engines.

Development and modification of a single overhead camshaft 4-valve 4-stroke 135 cc formula varsity race car engine

NASA Astrophysics Data System (ADS)

Abdullah, M. A.; Tamaldin, N.; Rusnandi, H.; Manoharan, T.; Samsir, M. A.

2013-12-01

The engine that was chosen to be developed and modified is Yamaha LC 135 Single Overhead Camshaft (SOHC) 4-valve 4-stroke 135cc liquid-cooled engine. The engine selection is based on the specification, rule and regulation in UTeM Formula Varsity 2012 (FV 2012). The engine performance is determined by engine operating characteristics. The engine air flow affects the filtration, intake and exhaust systems. The heat from the engine rejected to the surrounding through the active cooling system which has radiator and fan. The selection of the engine is based on weighted decision matrix which consists of reliability, operating and maintenance cost, fuel consumption and weight. The score of the matrix is formulated based on relative weighted factor among the selections. It been compared between Yamaha LC 135 Single Overhead Camshaft (SOHC) 4-valve 4-stroke 135cc liquid-cooled engine, Honda Wave 125 X Air Cooled, 4 Cycle Engine Overhead Camshaft (OHC) and Suzuki Shogun RR 4 stroke air cooled Single Overhead Camshaft (SOHC). The modification is applied to the engine through the simulation and tuning of Capacitor Discharge Ignition (CDI).

Engineering Students at Typically Invisible Transition Points: A Focus on Admissions and the Sophomore Year

ERIC Educational Resources Information Center

Holloway, Elizabeth M.

2013-01-01

As of 2012, women are approximately 19% of all engineering undergraduate students nationally (American Society for Engineering Education, 2012). Women's representation in engineering has not changed significantly over the last 20 years, despite increased attention, increased funding, and increased programmatic activities intended to encourage more…

Development of a One-Stop Data Search and Discovery Engine using Ontologies for Semantic Mappings (HydroSeek)

NASA Astrophysics Data System (ADS)

Piasecki, M.; Beran, B.

2007-12-01

Search engines have changed the way we see the Internet. The ability to find the information by just typing in keywords was a big contribution to the overall web experience. While the conventional search engine methodology worked well for textual documents, locating scientific data remains a problem since they are stored in databases not readily accessible by search engine bots. Considering different temporal, spatial and thematic coverage of different databases, especially for interdisciplinary research it is typically necessary to work with multiple data sources. These sources can be federal agencies which generally offer national coverage or regional sources which cover a smaller area with higher detail. However for a given geographic area of interest there often exists more than one database with relevant data. Thus being able to query multiple databases simultaneously is a desirable feature that would be tremendously useful for scientists. Development of such a search engine requires dealing with various heterogeneity issues. In scientific databases, systems often impose controlled vocabularies which ensure that they are generally homogeneous within themselves but are semantically heterogeneous when moving between different databases. This defines the boundaries of possible semantic related problems making it easier to solve than with the conventional search engines that deal with free text. We have developed a search engine that enables querying multiple data sources simultaneously and returns data in a standardized output despite the aforementioned heterogeneity issues between the underlying systems. This application relies mainly on metadata catalogs or indexing databases, ontologies and webservices with virtual globe and AJAX technologies for the graphical user interface. Users can trigger a search of dozens of different parameters over hundreds of thousands of stations from multiple agencies by providing a keyword, a spatial extent, i.e. a bounding box, and a temporal bracket. As part of this development we have also added an environment that allows users to do some of the semantic tagging, i.e. the linkage of a variable name (which can be anything they desire) to defined concepts in the ontology structure which in turn provides the backbone of the search engine.

A stirling engine computer model for performance calculations

NASA Technical Reports Server (NTRS)

Tew, R.; Jefferies, K.; Miao, D.

1978-01-01

To support the development of the Stirling engine as a possible alternative to the automobile spark-ignition engine, the thermodynamic characteristics of the Stirling engine were analyzed and modeled on a computer. The modeling techniques used are presented. The performance of an existing rhombic-drive Stirling engine was simulated by use of this computer program, and some typical results are presented. Engine tests are planned in order to evaluate this model.

Aerosol specification in single-column Community Atmosphere Model version 5

DOE PAGES

Lebassi-Habtezion, B.; Caldwell, P. M.

2015-03-27

Single-column model (SCM) capability is an important tool for general circulation model development. In this study, the SCM mode of version 5 of the Community Atmosphere Model (CAM5) is shown to handle aerosol initialization and advection improperly, resulting in aerosol, cloud-droplet, and ice crystal concentrations which are typically much lower than observed or simulated by CAM5 in global mode. This deficiency has a major impact on stratiform cloud simulations but has little impact on convective case studies because aerosol is currently not used by CAM5 convective schemes and convective cases are typically longer in duration (so initialization is less important).more » By imposing fixed aerosol or cloud-droplet and crystal number concentrations, the aerosol issues described above can be avoided. Sensitivity studies using these idealizations suggest that the Meyers et al. (1992) ice nucleation scheme prevents mixed-phase cloud from existing by producing too many ice crystals. Microphysics is shown to strongly deplete cloud water in stratiform cases, indicating problems with sequential splitting in CAM5 and the need for careful interpretation of output from sequentially split climate models. Droplet concentration in the general circulation model (GCM) version of CAM5 is also shown to be far too low (~ 25 cm −3) at the southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site.« less

Handbook of International alloy Compositions and Designations. Volume II. Superalloys

DTIC Science & Technology

1978-12-01

Offered in Italy 169 Table 12 . Typical Superalloys Offered in Japan 170 Table 13. Typical Superalloys Specified by Sweden 171 Table 14... 12 . Typical Superalloys Offered in Japan Table 13. Typical Superalloys Specified by Sweden Table 14. Typical Superalloys Offered in the Union of...Engineering Properties, INCO Europe Limited, London, England (1976), 12 pp. 8. IN-657 Cast-Nickel-Chromium-Niobium Alloy for Service Against Fuel + Ash

Engineering a General Education Program: Designing Mechanical Engineering General Education Courses

ERIC Educational Resources Information Center

Fagette, Paul; Chen, Shih-Jiun; Baran, George R.; Samuel, Solomon P.; Kiani, Mohammad F.

2013-01-01

The Department of Mechanical Engineering at our institution created two engineering courses for the General Education Program that count towards second level general science credit (traditional science courses are first level). The courses were designed for the general student population based upon the requirements of our General Education Program…

FAA Rotorcraft Research, Engineering, and Development Bibliography, 1962-1988. Supplement

DTIC Science & Technology

1989-03-01

fires, the aircraft engine was the major fire origin for twin- and single- engine air - craft. Only in single- engine aircraft was the instrument panel a...Certification Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the...Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the operator

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

Collaboration with Williams International to Demonstrate the Characteristics of a Foam-Metal-Liner Installed Over-the-Rotor of a Turbofan Engine

NASA Technical Reports Server (NTRS)

Sutliff, Daniel; Elliott, Dave; Jones, Mike; Hartley, Tom

2008-01-01

A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for foam-metal liner installed in close proximity to the fan. Two foam metal liner designs were tested and compared to the hardwall. Traditional Single-Degree-of-Freedom liner designs were also evaluated to provide a comparison. Normalized information on farfield acoustics is presented in this paper. The results show that up to 5 dB PWL overall attenuation was achieved in the forward quadrant. In general, the foam-metal liners performed better when the fan tip speed was below sonic.

The theoretical ultimate magnetoelectric coefficients of magnetoelectric composites by optimization design

NASA Astrophysics Data System (ADS)

Wang, H.-L.; Liu, B.

2014-03-01

This paper investigates what is the largest magnetoelectric (ME) coefficient of ME composites, and how to realize it. From the standpoint of energy conservation, a theoretical analysis is carried out on an imaginary lever structure consisting of a magnetostrictive phase, a piezoelectric phase, and a rigid lever. This structure is a generalization of various composite layouts for optimization on ME effect. The predicted theoretical ultimate ME coefficient plays a similar role as the efficiency of ideal heat engine in thermodynamics, and is used to evaluate the existing typical ME layouts, such as the parallel sandwiched layout and the serial layout. These two typical layouts exhibit ME coefficient much lower than the theoretical largest values, because in the general analysis the stress amplification ratio and the volume ratio can be optimized independently and freely, but in typical layouts they are dependent or fixed. To overcome this shortcoming and achieve the theoretical largest ME coefficient, a new design is presented. In addition, it is found that the most commonly used electric field ME coefficient can be designed to be infinitely large. We doubt the validity of this coefficient as a reasonable ME effect index and consider three more ME coefficients, namely the electric charge ME coefficient, the voltage ME coefficient, and the static electric energy ME coefficient. We note that the theoretical ultimate value of the static electric energy ME coefficient is finite and might be a more proper measure of ME effect.

The theoretical ultimate magnetoelectric coefficients of magnetoelectric composites by optimization design

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

Wang, H.-L.; Liu, B., E-mail: liubin@tsinghua.edu.cn

2014-03-21

This paper investigates what is the largest magnetoelectric (ME) coefficient of ME composites, and how to realize it. From the standpoint of energy conservation, a theoretical analysis is carried out on an imaginary lever structure consisting of a magnetostrictive phase, a piezoelectric phase, and a rigid lever. This structure is a generalization of various composite layouts for optimization on ME effect. The predicted theoretical ultimate ME coefficient plays a similar role as the efficiency of ideal heat engine in thermodynamics, and is used to evaluate the existing typical ME layouts, such as the parallel sandwiched layout and the serial layout.more » These two typical layouts exhibit ME coefficient much lower than the theoretical largest values, because in the general analysis the stress amplification ratio and the volume ratio can be optimized independently and freely, but in typical layouts they are dependent or fixed. To overcome this shortcoming and achieve the theoretical largest ME coefficient, a new design is presented. In addition, it is found that the most commonly used electric field ME coefficient can be designed to be infinitely large. We doubt the validity of this coefficient as a reasonable ME effect index and consider three more ME coefficients, namely the electric charge ME coefficient, the voltage ME coefficient, and the static electric energy ME coefficient. We note that the theoretical ultimate value of the static electric energy ME coefficient is finite and might be a more proper measure of ME effect.« less

The effect of single engine fixed wing air transport on rate-responsive pacemakers.

PubMed

De Rotte, A A; Van Der Kemp, P

1999-09-01

Insufficient information exists about the safety of patients with accelerometer-based rate-responsive pacemakers in air transport by general aviation aircraft. The response in pacing rate of two types of accelerometer-based rate-responsive pacemakers with data logging capabilities was studied during test flights with single engine fixed wing aircraft. Results were compared with the rate-response of these pacemakers during transportation by car and were also interpreted in respect to physiological heart rate response of aircrew during flights in single engine fixed wing aircraft. In addition, a continuous accelerometer readout was recorded during a turbulent phase of flight. This recording was used for a pacemaker-simulator experiment with maximal sensitive motion-sensor settings. Only a minor increase in pacing rate due to aircraft motion could be demonstrated during all phases of flight at all altitudes with the pacemakers programmed in the normal mode. This increase was of the same magnitude as induced during transport by car and would be of negligible influence on the performance of the individual pacemaker patient equipped with such a pacemaker. Moreover, simultaneous Holter monitoring of the pilots during these flights showed a similar rate-response in natural heart rate compared with the increase in pacing rate induced by aircraft motion in accelerometer-based rate-responsive pacemakers. No sensor-mediated pacemaker tachycardia was seen during any of these recordings. However, a 15% increase in pacing rate was induced by severe air turbulence. Programming the maximal sensitivity of the motion sensor into the pacemaker could, on the other hand, induce a significant increase in pacing rate as was demonstrated by the simulation experiments. These results seem to rule out potentially dangerous or adverse effects from motional or vibrational influences during transport in single engine fixed wing aircraft on accelerometer-based rate-responsive pacemakers with normal activity sensor settings.

Design of aircraft turbine fan drive gear transmission system

NASA Technical Reports Server (NTRS)

Dent, E.; Hirsch, R. A.; Peterson, V. W.

1970-01-01

The following basic types of gear reduction concepts were studied as being feasible power train systems for a low-bypass-ratio, single-spool, geared turbofan engine for general aircraft use: (1) single-stage external-internal reduction, (2) gears (offset shafting), (3) multiple compound idler gear system (concentric shafting), and (4) star gear planetary system with internal ring gear final output member (concentric shafting-counterrotation). In addition, studies were made of taking the accessories drive power off both the high-speed and low-speed shafting, using either face gears or spiral bevel gears. Both antifriction and sleeve-type bearings were considered for the external-internal and star-planet reduction concepts.

76 FR 9515 - Airworthiness Directives; Turbomeca S.A. ARRIEL 2B and 2B1 Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

.... ARRIEL 2B and 2B1 Turboshaft Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... (GG) Turbine Blade rupture occurred in service on ARRIEL 2 twin engine applications and recently one on a single engine helicopter. For the case occurring in flight on a single engine helicopter (ARRIEL...

10. View south of Arctic Observation Room (typical). Natick ...

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

10. View south of Arctic Observation Room (typical). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

Critical engine system design characteristics for SSTO vehicles

NASA Astrophysics Data System (ADS)

Fanciullo, Thomas J.; Judd, D. C.; Obrien, C. J.

1992-02-01

Engine system design characteristics are summarized for typical vertical take-off and landing (VTOL) and vertical take-off and horizontal landing (VTHL) Strategic Defense Initiative Organization (SDIO) single stage to orbit (SSTO) vehicles utilizing plug nozzle configurations. Power cycle selection trades involved the unique modular platelet engine (MPE) with the use of (1) LO2 and LH2 at fixed and variable mixture ratios, (2) LO2 and propane or RP-1, and (3) dual fuels (LO2 with LH2 and C3H8). The number of thrust cells and modules were optimized. Dual chamber bell and a cluster of conventional bell nozzle configurations were examined for comparison with the plug configuration. Thrust modulation (throttling) was selected for thrust vector control. Installed thrust ratings were established to provide an additional 20 percent overthrust capability for engine out operation. Turbopumps were designed to operate at subcritical speeds to facilitate a wide range of throttling and long life. A unique dual spool arrangement with hydrostatic bearings was selected for the LH2 turbopump. Controls and health monitoring with expert systems for diagnostics are critical subsystems to ensure minimum maintenance and supportability for a less than seven day turnaround. The use of an idle mode start, in conjunction with automated health condition monitoring, allows the rocket propulsion system to operate reliably in the manner of present day aircraft propulsion.

Real-time measurements of jet aircraft engine exhaust.

PubMed

Rogers, Fred; Arnott, Pat; Zielinska, Barbara; Sagebiel, John; Kelly, Kerry E; Wagner, David; Lighty, JoAnn S; Sarofim, Adel F

2005-05-01

Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.

HYDES: A generalized hybrid computer program for studying turbojet or turbofan engine dynamics

NASA Technical Reports Server (NTRS)

Szuch, J. R.

1974-01-01

This report describes HYDES, a hybrid computer program capable of simulating one-spool turbojet, two-spool turbojet, or two-spool turbofan engine dynamics. HYDES is also capable of simulating two- or three-stream turbofans with or without mixing of the exhaust streams. The program is intended to reduce the time required for implementing dynamic engine simulations. HYDES was developed for running on the Lewis Research Center's Electronic Associates (EAI) 690 Hybrid Computing System and satisfies the 16384-word core-size and hybrid-interface limits of that machine. The program could be modified for running on other computing systems. The use of HYDES to simulate a single-spool turbojet and a two-spool, two-stream turbofan engine is demonstrated. The form of the required input data is shown and samples of output listings (teletype) and transient plots (x-y plotter) are provided. HYDES is shown to be capable of performing both steady-state design and off-design analyses and transient analyses.

Ideal engine durations for gamma-ray-burst-jet launch

NASA Astrophysics Data System (ADS)

Hamidani, Hamid; Takahashi, Koh; Umeda, Hideyuki; Okita, Shinpei

2017-08-01

Aiming to study gamma-ray-burst (GRB) engine duration, we present numerical simulations to investigate collapsar jets. We consider typical explosion energy (1052 erg) but different engine durations, in the widest domain to date from 0.1 to 100 s. We employ an adaptive mesh refinement 2D hydrodynamical code. Our results show that engine duration strongly influences jet nature. We show that the efficiency of launching and collimating relativistic outflow increases with engine duration, until the intermediate engine range where it is the highest, past this point to long engine range, the trend is slightly reversed; we call this point where acceleration and collimation are the highest 'sweet spot' (˜10-30 s). Moreover, jet energy flux shows that variability is also high in this duration domain. We argue that not all engine durations can produce the collimated, relativistic and variable long GRB jets. Considering a typical progenitor and engine energy, we conclude that the ideal engine duration to reproduce a long GRB is ˜10-30 s, where the launch of relativistic, collimated and variable jets is favoured. We note that this duration domain makes a good link with a previous study suggesting that the bulk of Burst and Transient Source Experiment's long GRBs is powered by ˜10-20 s collapsar engines.

Compression-ignition engine performance with undoped and doped fuel oils and alcohol mixtures

NASA Technical Reports Server (NTRS)

Moore, Charles S; Foster, Hampton H

1939-01-01

Several fuel oils, doped fuel oils, and mixtures of alcohol and fuel oil were tested in a high-speed, single-cylinder, compression-ignition engine to determine power output, fuel consumption, and ignition and combustion characteristics. Fuel oils or doped fuel oils of high octane number had shorter ignition lags, lower rates of pressure rise, and gave smoother engine operation than fuel oils or doped fuel oils of low octane number. Higher engine rotative speeds and boost pressures resulted in smoother engine operation and permitted the use of fuel oils of relatively low octane number. Although the addition of a dope to a fuel oil decreased the ignition lag and the rate of pressure rise, the ensuing rate of combustion was somewhat slower than for the undoped fuel oil so that the effectiveness of combustion was practically unchanged. Alcohol used as an auxiliary fuel, either as a mixture or by separate injection, increased the rates of pressure rise and induced roughness. In general, the power output decreased as the proportion of alcohol increased and, below maximum power, varied with the heating value of the total fuel charge.

24 CFR 3285.4 - Incorporation by reference (IBR).

Code of Federal Regulations, 2012 CFR

2012-04-01

...-6600, fax number (253) 565-7265. (1) PS1-95, Construction and Industrial Plywood (with typical APA... for Engineering Purposes (Unified Soil Classification System), 2000, IBR approved for the table at... purchase from the Structural Engineering Institute/American Society of Civil Engineers (SEI/ASCE), 1801...

24 CFR 3285.4 - Incorporation by reference (IBR).

Code of Federal Regulations, 2011 CFR

2011-04-01

...-6600, fax number (253) 565-7265. (1) PS1-95, Construction and Industrial Plywood (with typical APA... for Engineering Purposes (Unified Soil Classification System), 2000, IBR approved for the table at... purchase from the Structural Engineering Institute/American Society of Civil Engineers (SEI/ASCE), 1801...

Bulk Metallic Glasses and Composites for Optical and Compliant Mechanisms

NASA Technical Reports Server (NTRS)

Hofmann, Douglas C.; Agnes, Gregory S.

2013-01-01

Mechanisms are used widely in engineering applications due to their ability to translate force and movement. They are found in kinematic pairs, gears, cams, linkages, and in flexure mechanisms (also known as compliant mechanisms). Mechanisms and flexures are used widely in spacecraft design, especially in the area of optics, where precise positioning of telescope mirrors requires elastic flexing of elements. A compliant mechanism is generally defined as a flexible mechanism that uses an elastic body deformation to cause a displacement (such as positing a mirror). The mechanisms are usually constructed as a single monolithic piece of material, and contain thin struts to allow for large elastic bending with low input force. This creates the largest problem with developing precise mechanisms; they must be fabricated from a single piece of metal, but are required to have strict accuracy on their dimensions. They are generally required to have high strength, elasticity, and low coefficient of thermal expansion.

Quantum fuel with multilevel atomic coherence for ultrahigh specific work in a photonic Carnot engine

NASA Astrophysics Data System (ADS)

Türkpençe, Deniz; Müstecaplıoǧlu, Özgür E.

2016-01-01

We investigate scaling of work and efficiency of a photonic Carnot engine with a number of quantum coherent resources. Specifically, we consider a generalization of the "phaseonium fuel" for the photonic Carnot engine, which was first introduced as a three-level atom with two lower states in a quantum coherent superposition by M. O. Scully, M. Suhail Zubairy, G. S. Agarwal, and H. Walther [Science 299, 862 (2003), 10.1126/science.1078955], to the case of N +1 level atoms with N coherent lower levels. We take into account atomic relaxation and dephasing as well as the cavity loss and derive a coarse-grained master equation to evaluate the work and efficiency analytically. Analytical results are verified by microscopic numerical examination of the thermalization dynamics. We find that efficiency and work scale quadratically with the number of quantum coherent levels. Quantum coherence boost to the specific energy (work output per unit mass of the resource) is a profound fundamental difference of quantum fuel from classical resources. We consider typical modern resonator set ups and conclude that multilevel phaseonium fuel can be utilized to overcome the decoherence in available systems. Preparation of the atomic coherences and the associated cost of coherence are analyzed and the engine operation within the bounds of the second law is verified. Our results bring the photonic Carnot engines much closer to the capabilities of current resonator technologies.

9. View to west of Tropic Dressing Room (typical). ...

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

9. View to west of Tropic Dressing Room (typical). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

Study of small turbofan engines applicable to general-aviation aircraft

NASA Technical Reports Server (NTRS)

Merrill, G. L.; Burnett, G. A.; Alsworth, C. C.

1973-01-01

The applicability of small turbofan engines to general aviation aircraft is discussed. The engine and engine/airplane performance, weight, size, and cost interrelationships are examined. The effects of specific engine noise constraints are evaluated. The factors inhibiting the use of turbofan engines in general aviation aircraft are identified.

Aerodynamic design optimization of a fuel efficient high-performance, single-engine, business airplane

NASA Technical Reports Server (NTRS)

Holmes, B. J.

1980-01-01

A design study has been conducted to optimize a single-engine airplane for a high-performance cruise mission. The mission analyzed included a cruise speed of about 300 knots, a cruise range of about 1300 nautical miles, and a six-passenger payload (5340 N (1200 lb)). The purpose of the study is to investigate the combinations of wing design, engine, and operating altitude required for the mission. The results show that these mission performance characteristics can be achieved with fuel efficiencies competitive with present-day high-performance, single- and twin-engine, business airplanes. It is noted that relaxation of the present Federal Aviation Regulation, Part 23, stall-speed requirement for single-engine airplanes facilitates the optimization of the airplane for fuel efficiency.

Single-molecule sequencing of the desiccation-tolerant grass Oropetium thomaeum.

PubMed

VanBuren, Robert; Bryant, Doug; Edger, Patrick P; Tang, Haibao; Burgess, Diane; Challabathula, Dinakar; Spittle, Kristi; Hall, Richard; Gu, Jenny; Lyons, Eric; Freeling, Michael; Bartels, Dorothea; Ten Hallers, Boudewijn; Hastie, Alex; Michael, Todd P; Mockler, Todd C

2015-11-26

Plant genomes, and eukaryotic genomes in general, are typically repetitive, polyploid and heterozygous, which complicates genome assembly. The short read lengths of early Sanger and current next-generation sequencing platforms hinder assembly through complex repeat regions, and many draft and reference genomes are fragmented, lacking skewed GC and repetitive intergenic sequences, which are gaining importance due to projects like the Encyclopedia of DNA Elements (ENCODE). Here we report the whole-genome sequencing and assembly of the desiccation-tolerant grass Oropetium thomaeum. Using only single-molecule real-time sequencing, which generates long (>16 kilobases) reads with random errors, we assembled 99% (244 megabases) of the Oropetium genome into 625 contigs with an N50 length of 2.4 megabases. Oropetium is an example of a 'near-complete' draft genome which includes gapless coverage over gene space as well as intergenic sequences such as centromeres, telomeres, transposable elements and rRNA clusters that are typically unassembled in draft genomes. Oropetium has 28,466 protein-coding genes and 43% repeat sequences, yet with 30% more compact euchromatic regions it is the smallest known grass genome. The Oropetium genome demonstrates the utility of single-molecule real-time sequencing for assembling high-quality plant and other eukaryotic genomes, and serves as a valuable resource for the plant comparative genomics community.

Statistical Teleodynamics: Toward a Theory of Emergence.

PubMed

Venkatasubramanian, Venkat

2017-10-24

The central scientific challenge of the 21st century is developing a mathematical theory of emergence that can explain and predict phenomena such as consciousness and self-awareness. The most successful research program of the 20th century, reductionism, which goes from the whole to parts, seems unable to address this challenge. This is because addressing this challenge inherently requires an opposite approach, going from parts to the whole. In addition, reductionism, by the very nature of its inquiry, typically does not concern itself with teleology or purposeful behavior. Modeling emergence, in contrast, requires the addressing of teleology. Together, these two requirements present a formidable challenge in developing a successful mathematical theory of emergence. In this article, I describe a new theory of emergence, called statistical teleodynamics, that addresses certain aspects of the general problem. Statistical teleodynamics is a mathematical framework that unifies three seemingly disparate domains-purpose-free entities in statistical mechanics, human engineered teleological systems in systems engineering, and nature-evolved teleological systems in biology and sociology-within the same conceptual formalism. This theory rests on several key conceptual insights, the most important one being the recognition that entropy mathematically models the concept of fairness in economics and philosophy and, equivalently, the concept of robustness in systems engineering. These insights help prove that the fairest inequality of income is a log-normal distribution, which will emerge naturally at equilibrium in an ideal free market society. Similarly, the theory predicts the emergence of the three classes of network organization-exponential, scale-free, and Poisson-seen widely in a variety of domains. Statistical teleodynamics is the natural generalization of statistical thermodynamics, the most successful parts-to-whole systems theory to date, but this generalization is only a modest step toward a more comprehensive mathematical theory of emergence.

Ionic Liquid Fuels for Chemical Propulsion

DTIC Science & Technology

2012-03-01

particular: “ Molten salts are nothing new, but these were the only ones I ever heard of that were liquid at 25°C. I’ve never found a use for the...Ethylammonium nitrate is generally regarded as the first reported room temperature ionic liquid (RTIL). Since it is a nitrate salt , it certainly...carry the advantages of engineering simplicity associated with the fuel and oxidizer residing in a single tank . However, by itself, ethylammonium

Thermodynamics on Soluble Carbon Nanotubes: How Do DNA Molecules Replace Surfactants on Carbon Nanotubes?

PubMed Central

Kato, Yuichi; Inoue, Ayaka; Niidome, Yasuro; Nakashima, Naotoshi

2012-01-01

Here we represent thermodynamics on soluble carbon nanotubes that enables deep understanding the interactions between single-walled carbon nanotubes (SWNTs) and molecules. We selected sodium cholate and single-stranded cytosine oligo-DNAs (dCn (n = 4, 5, 6, 7, 8, 10, 15, and 20)), both of which are typical SWNT solubilizers, and successfully determined thermodynamic properties (ΔG, ΔH and ΔS values) for the exchange reactions of sodium cholate on four different chiralities of SWNTs ((n,m) = (6,5), (7,5), (10,2), and (8,6)) for the DNAs. Typical results contain i) the dC5 exhibited an exothermic exchange, whereas the dC6, 8, 10, 15, and 20 materials exhibited endothermic exchanges, and ii) the energetics of the dC4 and dC7 exchanges depended on the associated chiral indices and could be endothermic or exothermic. The presented method is general and is applicable to any molecule that interacts with nanotubes. The study opens a way for science of carbon nanotube thermodynamics. PMID:23066502

Local Heat Flux Measurements with Single and Small Multi-element Coaxial Element-Injectors

NASA Technical Reports Server (NTRS)

Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James

2006-01-01

To support NASA's Vision for Space Exploration mission, the NASA Marshall Space Flight Center conducted a program in 2005 to improve the capability to predict local thermal compatibility and heat transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak heat flux due to injector design, resulting in a significant improvement in overall engine reliability and durability. Such analyses are applicable to combustion devices in booster, upper stage, and in-space engines with regeneratively cooled chamber walls, as well as in small thrust chambers with few elements in the injector. In this program, single and three-element injectors were hot-fire tested with liquid oxygen and gaseous hydrogen propellants at The Pennsylvania State University Cryogenic Combustor Laboratory from May to August 2005. Local heat fluxes were measured in a 1-inch internal diameter heat sink combustion chamber using Medtherm coaxial thermocouples and Gardon heat flux gauges, Injector configurations were tested with both shear coaxial elements and swirl coaxial elements. Both a straight and a scarfed single element swirl injector were tested. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three coaxial shear and swirl elements. Detailed geometry and test results the for shear coax elements has already been published. Detailed test result for the remaining 6 swirl coax element for the will be published in a future JANNAF presentation to provide well-defined data sets for development and model validation.

Local Heat Flux Measurements with Single Element Coaxial Injectors

NASA Technical Reports Server (NTRS)

Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James

2006-01-01

To support the mission for the NASA Vision for Space Exploration, the NASA Marshall Space Flight Center conducted a program in 2005 to improve the capability to predict local thermal compatibility and heat transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak heat flux due to injector design, resulting in a significant improvement in overall engine reliability and durability. Such analyses are applicable to combustion devices in booster, upper stage, and in-space engines, as well as for small thrusters with few elements in the injector. In this program, single element and three-element injectors were hot-fire tested with liquid oxygen and ambient temperature gaseous hydrogen propellants at The Pennsylvania State University Cryogenic Combustor Laboratory from May to August 2005. Local heat fluxes were measured in a 1-inch internal diameter heat sink combustion chamber using Medtherm coaxial thermocouples and Gardon heat flux gauges. Injectors were tested with shear coaxial and swirl coaxial elements, including recessed, flush and scarfed oxidizer post configurations, and concentric and non-concentric fuel annuli. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three of the single element injectors - recessed-post shear coaxial with concentric fuel, flush-post swirl coaxial with concentric fuel, and scarfed-post swirl coaxial with concentric fuel. Detailed geometry and test results will be published elsewhere to provide well-defined data sets for injector development and model validatation.

Why Engineers Should Consider Formal Methods

NASA Technical Reports Server (NTRS)

Holloway, C. Michael

1997-01-01

This paper presents a logical analysis of a typical argument favoring the use of formal methods for software development, and suggests an alternative argument that is simpler and stronger than the typical one.

19. CONSTRUCTION PROGRESS PHOTO SHOWING (TYPICALLY COMPLEX) WASTE HOLDING CELL ...

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

19. CONSTRUCTION PROGRESS PHOTO SHOWING (TYPICALLY COMPLEX) WASTE HOLDING CELL PIPING. INEEL PHOTO NUMBER NRTS-59-3212. - Idaho National Engineering Laboratory, Old Waste Calcining Facility, Scoville, Butte County, ID

Vertical motion simulator familiarization guide

NASA Technical Reports Server (NTRS)

Danek, George L.

1993-01-01

The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

Primary battery design and safety guidelines handbook

NASA Technical Reports Server (NTRS)

Bragg, Bobby J.; Casey, John E.; Trout, J. Barry

1994-01-01

This handbook provides engineers and safety personnel with guidelines for the safe design or selection and use of primary batteries in spaceflight programs. Types of primary batteries described are silver oxide zinc alkaline, carbon-zinc, zinc-air alkaline, manganese dioxide-zionc alkaline, mercuric oxide-zinc alkaline, and lithium anode cells. Along with typical applications, the discussions of the individual battery types include electrochemistry, construction, capacities and configurations, and appropriate safety measures. A chapter on general battery safety covers hazard sources and controls applicable to all battery types. Guidelines are given for qualification and acceptance testing that should precede space applications. Permissible failure levels for NASA applications are discussed.

Engineering the on-axis intensity of Bessel beam by a feedback tuning loop

NASA Astrophysics Data System (ADS)

Li, Runze; Yu, Xianghua; Yang, Yanlong; Peng, Tong; Yao, Baoli; Zhang, Chunmin; Ye, Tong

2018-02-01

The Bessel beam belongs to a typical class of non-diffractive optical fields that are characterized by their invariant focal profiles along the propagation direction. However, ideal Bessel beams only rigorously exist in theory; Bessel beams generated in the lab are quasi-Bessel beams with finite focal extensions and varying intensity profiles along the propagation axis. The ability to engineer the on-axis intensity profile to the desired shape is essential for many applications. Here we demonstrate an iterative optimization-based approach to engineering the on-axis intensity of Bessel beams. The genetic algorithm is used to demonstrate this approach. Starting with a traditional axicon phase mask, in the design process, the computed on-axis beam profile is fed into a feedback tuning loop of an iterative optimization process, which searches for an optimal radial phase distribution that can generate a generalized Bessel beam with the desired onaxis intensity profile. The experimental implementation involves a fine-tuning process that adjusts the originally targeted profile so that the optimization process can optimize the phase mask to yield an improved on-axis profile. Our proposed method has been demonstrated in engineering several zeroth-order Bessel beams with customized on-axis profiles. High accuracy and high energy throughput merit its use in many applications.

Solitary Septated Simple Liver Cyst in a Newborn Infant

PubMed Central

Alviedo, Neil; Kent, Amanda; Cohen, Inbal

2015-01-01

Simple liver cysts (SLC) are generally rare and are typically symptomatic when detected in infancy. We present a case of a newborn infant in whom fetal ultrasound and MRI revealed a cystic structure. Postnatal imaging revealed a septated, single cystic structure causing mass effect on the common bile duct and partially obstructing the inferior vena cava. Treatment of a solitary septated SLC was successful by laparoscopic total excision. The infant had an uncomplicated postsurgical course and has done well. PMID:26203457

Telescoping Mechanics: A New Paradigm for Composite Behavior Simulation

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Murthy, P. L. N.; Gotsis, P. K.; Mital. S. K.

2004-01-01

This report reviews the application of telescoping mechanics to composites using recursive laminate theory. The elemental scale is the fiber-matrix slice, the behavior of which propagates to laminate. The results from using applications for typical, hybrid, and smart composites and composite-enhanced reinforced concrete structures illustrate the versatility and generality of telescoping scale mechanics. Comparisons with approximate, single-cell, and two- and three-dimensional finite-element methods demonstrate the accuracy and computational effectiveness of telescoping scale mechanics for predicting complex composite behavior.

Compendium of Experimental Cetane Numbers

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

Yanowitz, J.; Ratcliff, M. A.; McCormick, R. L.

This report is an updated version of the 2004 Compendium of Experimental Cetane Number Data and presents a compilation of measured cetane numbers for pure chemical compounds. It includes all available single compound cetane number data found in the scientific literature up until March 2014 as well as a number of unpublished values, most measured over the past decade at the National Renewable Energy Laboratory. This Compendium contains cetane values for 389 pure compounds, including 189 hydrocarbons and 201 oxygenates. More than 250 individual measurements are new to this version of the Compendium. For many compounds, numerous measurements are included,more » often collected by different researchers using different methods. Cetane number is a relative ranking of a fuel's autoignition characteristics for use in compression ignition engines; it is based on the amount of time between fuel injection and ignition, also known as ignition delay. The cetane number is typically measured either in a single-cylinder engine or a constant volume combustion chamber. Values in the previous Compendium derived from octane numbers have been removed, and replaced with a brief analysis of the correlation between cetane numbers and octane numbers. The discussion on the accuracy and precision of the most commonly used methods for measuring cetane has been expanded and the data has been annotated extensively to provide additional information that will help the reader judge the relative reliability of individual results.« less

Broad specification fuels technology program, phase 1

NASA Technical Reports Server (NTRS)

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

1982-01-01

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

Tracing medical information over the Internet.

PubMed

Mutairi, S M

2000-05-01

The Internet became with do doubt a huge and valuable source of information for researchers. The wealth of information on the Internet is second to none and medical information is no exception. Yet with the vast expansion of the Internet and the World Wide Web in specie, to find the kind of information one is looking for, he/she needs to browse thousands of web sites and the experience would be like digging into a stack of hay looking for a needle. That's why search engines and subject indexes, as means to overcome this problem, were introduced and grew so rapidly. In general, there are three approaches to retrieve data from the World Wide Web; the subject directories, search engines and detailed subject indexes. However, there is no single comprehensive search engine or directory and it is recommended to use more than one with different keywords and synonymous.

Anisotropic-Strain-Induced Band Gap Engineering in Nanowire-Based Quantum Dots.

PubMed

Francaviglia, Luca; Giunto, Andrea; Kim, Wonjong; Romero-Gomez, Pablo; Vukajlovic-Plestina, Jelena; Friedl, Martin; Potts, Heidi; Güniat, Lucas; Tütüncüoglu, Gözde; Fontcuberta I Morral, Anna

2018-04-11

Tuning light emission in bulk and quantum structures by strain constitutes a complementary method to engineer functional properties of semiconductors. Here, we demonstrate the tuning of light emission of GaAs nanowires and their quantum dots up to 115 meV by applying strain through an oxide envelope. We prove that the strain is highly anisotropic and clearly results in a component along the NW longitudinal axis, showing good agreement with the equations of uniaxial stress. We further demonstrate that the strain strongly depends on the oxide thickness, the oxide intrinsic strain, and the oxide microstructure. We also show that ensemble measurements are fully consistent with characterizations at the single-NW level, further elucidating the general character of the findings. This work provides the basic elements for strain-induced band gap engineering and opens new avenues in applications where a band-edge shift is necessary.

Rationally designed synthetic protein hydrogels with predictable mechanical properties.

PubMed

Wu, Junhua; Li, Pengfei; Dong, Chenling; Jiang, Heting; Bin Xue; Gao, Xiang; Qin, Meng; Wang, Wei; Bin Chen; Cao, Yi

2018-02-12

Designing synthetic protein hydrogels with tailored mechanical properties similar to naturally occurring tissues is an eternal pursuit in tissue engineering and stem cell and cancer research. However, it remains challenging to correlate the mechanical properties of protein hydrogels with the nanomechanics of individual building blocks. Here we use single-molecule force spectroscopy, protein engineering and theoretical modeling to prove that the mechanical properties of protein hydrogels are predictable based on the mechanical hierarchy of the cross-linkers and the load-bearing modules at the molecular level. These findings provide a framework for rationally designing protein hydrogels with independently tunable elasticity, extensibility, toughness and self-healing. Using this principle, we demonstrate the engineering of self-healable muscle-mimicking hydrogels that can significantly dissipate energy through protein unfolding. We expect that this principle can be generalized for the construction of protein hydrogels with customized mechanical properties for biomedical applications.

A Segmented Ion-Propulsion Engine

NASA Technical Reports Server (NTRS)

Brophy, John R.

1992-01-01

New design approach for high-power (100-kW class or greater) ion engines conceptually divides single engine into combination of smaller discharge chambers integrated to operate as single large engine. Analogous to multicylinder automobile engine, benefits include reduction in required accelerator system span-to-gap ratio for large-area engines, reduction in required hollow-cathode emission current, mitigation of plasma-uniformity problem, increased tolerance to accelerator system faults, and reduction in vacuum-system pumping speed.

Systems concept for speech technology application in general aviation

NASA Technical Reports Server (NTRS)

North, R. A.; Bergeron, H.

1984-01-01

The application potential of voice recognition and synthesis circuits for general aviation, single-pilot IFR (SPIFR) situations is examined. The viewpoint of the pilot was central to workload analyses and assessment of the effectiveness of the voice systems. A twin-engine, high performance general aviation aircraft on a cross-country fixed route was employed as the study model. No actual control movements were considered and other possible functions were scored by three IFR-rated instructors. The SPIFR was concluded helpful in alleviating visual and manual workloads during take-off, approach and landing, particularly for data retrieval and entry tasks. Voice synthesis was an aid in alerting a pilot to in-flight problems. It is expected that usable systems will be available within 5 yr.

Samarium Cobalt (SmCo) Generator/Engine Integration Study

DTIC Science & Technology

1980-04-01

110o1110 (Cole Ms -W~ Daiwa. to* J11 tuo.in Wfi wee -004"ni Aircraft Generator/starter Samarium Cobalt Turbine Engine , Feasibility Secondary Power...integration into the main rotor system of typical aircraft gas turbine engines . A major objective is the definition of the engine interface for such... Engine The F404 is a low bypass, augmented turbofan Pngine developed for application in advanced fighter aircraft (F-18). This type of engine benefits most

Linear aerospike engine. [for reusable single-stage-to-orbit vehicle

NASA Technical Reports Server (NTRS)

Kirby, F. M.; Martinez, A.

1977-01-01

A description is presented of a dual-fuel modular split-combustor linear aerospike engine concept. The considered engine represents an approach to an integrated engine for a reusable single-stage-to-orbit (SSTO) vehicle. The engine burns two fuels (hydrogen and a hydrocarbon) with oxygen in separate combustors. Combustion gases expand on a linear aerospike nozzle. An engine preliminary design is discussed. Attention is given to the evaluation process for selecting the optimum number of modules or divisions of the engine, aspects of cooling and power cycle balance, and details of engine operation.

Rotating Liner Engine: Improving Efficiency of Heavy Duty Diesels by Significant Friction Reduction, and Extending the Life of Heavy Duty Engines.

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

Dardalis, Dimitrios

2013-12-31

This report describes the work on converting a 4 cylinder Cummins ISB engine into a single cylinder Rotating Liner Engine functioning prototype that can be used to measure the friction benefits of rotating the cylinder liner in a high pressure compression ignition engine. A similar baseline engine was also prepared, and preliminary testing was done. Even though the fabrication of the single cylinder prototype was behind schedule due to machine shop delays, the fundamental soundness of the design elements are proven, and the engine has successfully functioned. However, the testing approach of the two engines, as envisioned by the originalmore » proposal, proved impossible due to torsional vibration resonance caused by the single active piston. A new approach for proper testing has been proposed,« less

Multi-blocking strategies for the INS3D incompressible Navier-Stokes code

NASA Technical Reports Server (NTRS)

Gatlin, Boyd

1990-01-01

With the continuing development of bigger and faster supercomputers, computational fluid dynamics (CFD) has become a useful tool for real-world engineering design and analysis. However, the number of grid points necessary to resolve realistic flow fields numerically can easily exceed the memory capacity of available computers. In addition, geometric shapes of flow fields, such as those in the Space Shuttle Main Engine (SSME) power head, may be impossible to fill with continuous grids upon which to obtain numerical solutions to the equations of fluid motion. The solution to this dilemma is simply to decompose the computational domain into subblocks of manageable size. Computer codes that are single-block by construction can be modified to handle multiple blocks, but ad-hoc changes in the FORTRAN have to be made for each geometry treated. For engineering design and analysis, what is needed is generalization so that the blocking arrangement can be specified by the user. INS3D is a computer program for the solution of steady, incompressible flow problems. It is used frequently to solve engineering problems in the CFD Branch at Marshall Space Flight Center. INS3D uses an implicit solution algorithm and the concept of artificial compressibility to provide the necessary coupling between the pressure field and the velocity field. The development of generalized multi-block capability in INS3D is described.

The design of two-stage-to-orbit vehicles

NASA Technical Reports Server (NTRS)

1991-01-01

Two separate student design groups developed conceptual designs for a two-stage-to-orbit vehicle, with each design group consisting of a carrier team and an orbiter team. A two-stage-to-orbit system is considered in the event that single-stage-to-orbit is deemed not feasible in the foreseeable future; the two-stage system would also be used as a complement to an already existing heavy lift vehicle. The design specifications given are to lift a 10,000-lb payload 27 ft long by 10 ft diameter, to low Earth orbit (300 n.m.) using an air breathing carrier configuration that will take off horizontally within 15,000 ft. The staging Mach number and altitude were to be determined by the design groups. One group designed a delta wing/body carrier with the orbiter nested within the fuselage of the carrier, and the other group produced a blended cranked-delta wing/body carrier with the orbiter in the more conventional piggyback configuration. Each carrier used liquid hydrogen-fueled turbofanramjet engines, with data provided by General Electric Aircraft Engine Group. While one orbiter used a full-scale Space Shuttle Main Engine (SSME), the other orbiter employed a half-scale SSME coupled with scramjet engines, with data again provided by General Electric. The two groups conceptual designs, along with the technical trade-offs, difficulties, and details that surfaced during the design process are presented.

Gender Contentedness in Aspirations to Become Engineers or Medical Doctors

ERIC Educational Resources Information Center

Koul, Ravinder; Lerdpornkulrat, Thanita; Poondej, Chanut

2017-01-01

Medical doctor and engineer are highly esteemed STEM professions. This study investigates academic and motivational characteristics of a sample of high school students in Thailand who aspire to become medical doctors or engineers. We used logistic regression to compare maths performance, gender typicality, gender contentedness, and maths and…

40 CFR 86.1327-96 - Engine dynamometer test procedures; overview.

Code of Federal Regulations, 2012 CFR

2012-07-01

... either in bags or continuously for hydrocarbons (HC), methane (CH4) carbon monoxide (CO), carbon dioxide..., methane and/or methanol and/or formaldehyde. In addition, for diesel-cycle engines, particulates are... if typical of the in-use application. (5) The engine may be equipped with a production-type starter...

40 CFR 86.1327-96 - Engine dynamometer test procedures; overview.

Code of Federal Regulations, 2013 CFR

2013-07-01

... either in bags or continuously for hydrocarbons (HC), methane (CH4) carbon monoxide (CO), carbon dioxide..., methane and/or methanol and/or formaldehyde. In addition, for diesel-cycle engines, particulates are... if typical of the in-use application. (5) The engine may be equipped with a production-type starter...

40 CFR 92.104 - Locomotive and engine testing; overview.

Code of Federal Regulations, 2011 CFR

2011-07-01

... restriction within 1 inch of water of the upper limit of a typical engine as installed with clean air filters...; overview. 92.104 Section 92.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92...

40 CFR 92.104 - Locomotive and engine testing; overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... restriction within 1 inch of water of the upper limit of a typical engine as installed with clean air filters...; overview. 92.104 Section 92.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92...

Teaching Engineering Ethics with Sustainability as Context

ERIC Educational Resources Information Center

Byrne, Edmond P.

2012-01-01

Purpose: The purpose of this paper is to ascertain the engagement and response of students to the teaching of engineering ethics incorporating a macro ethical framework whereby sustainability is viewed as context to professional practice. This involves incorporating a broader conception of engineering than is typically applied in conventional…

Incorporating the site variability and laboratory/in-situ testing variability of soil properties in geotechnical engineering design : research project capsule : technology transfer program.

DOT National Transportation Integrated Search

2016-04-01

While structural engineering deals with mostly homogeneous manmade materials : (e.g., concrete and steel), geotechnical engineering typically involves highly varied : natural materials (e.g., soil and rock). As a result, high variance of the resistan...

Technological Literacy Learning with Cumulative and Stepwise Integration of Equations into Electrical Circuit Diagrams

ERIC Educational Resources Information Center

Ozogul, G.; Johnson, A. M.; Moreno, R.; Reisslein, M.

2012-01-01

Technological literacy education involves the teaching of basic engineering principles and problem solving, including elementary electrical circuit analysis, to non-engineering students. Learning materials on circuit analysis typically rely on equations and schematic diagrams, which are often unfamiliar to non-engineering students. The goal of…

Measurement-Based Entanglement of Noninteracting Bosonic Atoms

NASA Astrophysics Data System (ADS)

Lester, Brian J.; Lin, Yiheng; Brown, Mark O.; Kaufman, Adam M.; Ball, Randall J.; Knill, Emanuel; Rey, Ana M.; Regal, Cindy A.

2018-05-01

We demonstrate the ability to extract a spin-entangled state of two neutral atoms via postselection based on a measurement of their spatial configuration. Typically, entangled states of neutral atoms are engineered via atom-atom interactions. In contrast, in our Letter, we use Hong-Ou-Mandel interference to postselect a spin-singlet state after overlapping two atoms in distinct spin states on an effective beam splitter. We verify the presence of entanglement and determine a bound on the postselected fidelity of a spin-singlet state of (0.62 ±0.03 ). The experiment has direct analogy to creating polarization entanglement with single photons and hence demonstrates the potential to use protocols developed for photons to create complex quantum states with noninteracting atoms.

Measurement-Based Entanglement of Noninteracting Bosonic Atoms.

PubMed

Lester, Brian J; Lin, Yiheng; Brown, Mark O; Kaufman, Adam M; Ball, Randall J; Knill, Emanuel; Rey, Ana M; Regal, Cindy A

2018-05-11

We demonstrate the ability to extract a spin-entangled state of two neutral atoms via postselection based on a measurement of their spatial configuration. Typically, entangled states of neutral atoms are engineered via atom-atom interactions. In contrast, in our Letter, we use Hong-Ou-Mandel interference to postselect a spin-singlet state after overlapping two atoms in distinct spin states on an effective beam splitter. We verify the presence of entanglement and determine a bound on the postselected fidelity of a spin-singlet state of (0.62±0.03). The experiment has direct analogy to creating polarization entanglement with single photons and hence demonstrates the potential to use protocols developed for photons to create complex quantum states with noninteracting atoms.

Trajectory Simulation of Meteors Assuming Mass Loss and Fragmentation

NASA Technical Reports Server (NTRS)

Allen, Gary A., Jr.; Prabhu, Dinesh K.; Saunders, David A

2015-01-01

Program used to simulate atmospheric flight trajectories of entry capsules [1] Includes models of atmospheres of different planetary destinations - Earth, Mars, Venus, Jupiter, Saturn, Uranus, Titan, ... Solves 3-­-degrees of freedom (3DoF) equations for a single body treated as a point mass. Also supports 6-DoF trajectory simula4on and Monte Carlo analyses. Uses Fehlberg-­-Runge-­-Kuna (4th-5th order) time integraion with automaic step size control. Includes rotating spheroidal planet with gravitational field having a J2 harmonic. Includes a variety of engineering aerodynamic and heat flux models. Capable of specifying events - heatshield jettison, parachute deployment, etc. - at predefined altitudes or Mach number. Has material thermal response models of typical aerospace materials integrated.

Successfully use agglomeration for size enlargement

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

Pietsch, W.

1996-04-01

The processing of fine and ultrafine particles by size enlargement finds an ever increasing application. At the same time, undesirable agglomeration such as buildup, caking, bridging, and uncontrolled aggregation of fine particles can occur during processing and handling of these particulate solids. This article will provide a survey of the phenomena of agglomeration and discuss the unit operation of size enlargement by agglomeration. This article is also an invitation, particularly to young engineers, to become interested in agglomeration. Considering that mechanical process technologies are requiring more energy every year than any other group of consumers and efficiencies are typically inmore » the single digits or teens at best, considerable rewards can be expected from the development of scientifically modified, more energy-efficient methods and equipment.« less

Transient Simulation of Pressure Oscillations in the Fuel Feedline of the Fastrac Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Bullard, Brad

1998-01-01

During mainstage testing of the 60,000 lbf thrust Fastrac thrust chamber at MSFC's Test Stand 116 (TS 116), sustained, large amplitude oscillations near 530 Hz were observed in the pressure data. These oscillations were detected both in the RP-1 feedline, downstream of the cavitating venturi, and in the combustion chamber. The driver of the instability is believed to be feedline excitation driven by either periodic cavity collapse at the exit of the cavitating venturi or combustion instability. In covitating venturi, static pressure drops as the flow passes through a constriction resembling a converging-diverging nozzle until the vapor pressure is reached. At the venturi throat, the flow is essentially choked, which is why these devices are typically used for mass flow rate control and disturbance isolation. Typically, a total pressure drop of 15% or more across the venturi is required for cavitation. For much larger pressure differentials, unstable cavities can form and subsequently collapse downstream of the throat. Although the disturbances generated by cavitating venturis is generally considered to be broad-band, this type of phenomena could generate periodic behavior capable of exciting the feedline. An excitation brought about by combustion instability would result from the coupling of a combustion chamber acoustic mode and a feedline resonance frequency. This type of coupling is referred to as "buzz" and is not uncommon for engines in this thrust range.

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

Hooker, J.N.

This report describes an investigation of energy consumption and efficiency of oil pipelines in the US in 1978. It is based on a simulation of the actual movement of oil on a very detailed representation of the pipeline network, and it uses engineering equations to calculate the energy that pipeline pumps must have exerted on the oil to move it in this manner. The efficiencies of pumps and drivers are estimated so as to arrive at the amount of energy consumed at pumping stations. The throughput in each pipeline segment is estimated by distributing each pipeline company's reported oil movementsmore » over its segments in proportions predicted by regression equations that show typical throughput and throughput capacity as functions of pipe diameter. The form of the equations is justified by a generalized cost-engineering study of pipelining, and their parameters are estimated using new techniques developed for the purpose. A simplified model of flow scheduling is chosen on the basis of actual energy use data obtained from a few companies. The study yields energy consumption and intensiveness estimates for crude oil trunk lines, crude oil gathering lines and oil products lines, for the nation as well as by state and by pipe diameter. It characterizes the efficiency of typical pipelines of various diameters operating at capacity. Ancillary results include estimates of oil movements by state and by diameter and approximate pipeline capacity utilization nationwide.« less

Next Generation NASA GA Advanced Concept

NASA Technical Reports Server (NTRS)

Hahn, Andrew S.

2006-01-01

Not only is the common dream of frequent personal flight travel going unfulfilled, the current generation of General Aviation (GA) is facing tremendous challenges that threaten to relegate the Single Engine Piston (SEP) aircraft market to a footnote in the history of U.S. aviation. A case is made that this crisis stems from a generally low utility coupled to a high cost that makes the SEP aircraft of relatively low transportation value and beyond the means of many. The roots of this low value are examined in a broad sense, and a Next Generation NASA Advanced GA Concept is presented that attacks those elements addressable by synergistic aircraft design.

Improved NASA-ANOPP Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems

NASA Technical Reports Server (NTRS)

Kontos, K. B.; Janardan, B. A.; Gliebe, P. R.

1996-01-01

Recent experience using ANOPP to predict turbofan engine flyover noise suggests that it over-predicts overall EPNL by a significant amount. An improvement in this prediction method is desired for system optimization and assessment studies of advanced UHB engines. An assessment of the ANOPP fan inlet, fan exhaust, jet, combustor, and turbine noise prediction methods is made using static engine component noise data from the CF6-8OC2, E(3), and QCSEE turbofan engines. It is shown that the ANOPP prediction results are generally higher than the measured GE data, and that the inlet noise prediction method (Heidmann method) is the most significant source of this overprediction. Fan noise spectral comparisons show that improvements to the fan tone, broadband, and combination tone noise models are required to yield results that more closely simulate the GE data. Suggested changes that yield improved fan noise predictions but preserve the Heidmann model structure are identified and described. These changes are based on the sets of engine data mentioned, as well as some CFM56 engine data that was used to expand the combination tone noise database. It should be noted that the recommended changes are based on an analysis of engines that are limited to single stage fans with design tip relative Mach numbers greater than one.

Effect of anhydrous ethanol/gasoline blends on performance and exhaust emissions of spark-ignited non-road engines.

PubMed

Ribeiro, Camilo Bastos; Martins, Kelly Geronazzo; Gueri, Matheus Vitor Diniz; Pavanello, Guilherme Pozzobom; Schirmer, Waldir Nagel

2018-06-12

Ethanol is a renewable fuel and it is considered an alternative to gasoline in Otto-cycle engines. The present study evaluated the behavior of exhaustion gas carbon monoxide (CO) and total hydrocarbons (THC) according to the levels of anhydrous ethyl alcohol (AEA) added to gasoline in different proportions (E0, E10, E20, E27, that is, pure gasoline and its blends with AEA at 10, 20, and 27% v/v) in the use of non-road single cylinder engines of different powers (13 and 6.5 hp), to the loads applied to engine-generators and the air-fuel ratio (A/F) admitted to the engine cylinders. Also, the performance of engine-generators was verified in terms of mass, specific and energetic consumption and efficiency of the evaluated systems for the same blends and loads. The results showed that an increase in the AEA content in the blend resulted in significant drops in CO and THC concentrations for both engine-generators, while fuel consumption showed a slight upward trend; the increases in applied loads resulted in an increase in CO and THC concentrations and fuel consumption. In general, a higher AEA content (oxygenated) in the blends had a greater effect on gaseous emissions compared to the effect on consumption and system efficiency.

Color postprocessing for 3-dimensional finite element mesh quality evaluation and evolving graphical workstation

NASA Technical Reports Server (NTRS)

Panthaki, Malcolm J.

1987-01-01

Three general tasks on general-purpose, interactive color graphics postprocessing for three-dimensional computational mechanics were accomplished. First, the existing program (POSTPRO3D) is ported to a high-resolution device. In the course of this transfer, numerous enhancements are implemented in the program. The performance of the hardware was evaluated from the point of view of engineering postprocessing, and the characteristics of future hardware were discussed. Second, interactive graphical tools implemented to facilitate qualitative mesh evaluation from a single analysis. The literature was surveyed and a bibliography compiled. Qualitative mesh sensors were examined, and the use of two-dimensional plots of unaveraged responses on the surface of three-dimensional continua was emphasized in an interactive color raster graphics environment. Finally, a postprocessing environment was designed for state-of-the-art workstation technology. Modularity, personalization of the environment, integration of the engineering design processes, and the development and use of high-level graphics tools are some of the features of the intended environment.

Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology

NASA Technical Reports Server (NTRS)

Hebert, Leonard J.

2006-01-01

This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.

Nonlinear dynamic simulation of single- and multi-spool core engines

NASA Technical Reports Server (NTRS)

Schobeiri, T.; Lippke, C.; Abouelkheir, M.

1993-01-01

In this paper a new computational method for accurate simulation of the nonlinear dynamic behavior of single- and multi-spool core engines, turbofan engines, and power generation gas turbine engines is presented. In order to perform the simulation, a modularly structured computer code has been developed which includes individual mathematical modules representing various engine components. The generic structure of the code enables the dynamic simulation of arbitrary engine configurations ranging from single-spool thrust generation to multi-spool thrust/power generation engines under adverse dynamic operating conditions. For precise simulation of turbine and compressor components, row-by-row calculation procedures were implemented that account for the specific turbine and compressor cascade and blade geometry and characteristics. The dynamic behavior of the subject engine is calculated by solving a number of systems of partial differential equations, which describe the unsteady behavior of the individual components. In order to ensure the capability, accuracy, robustness, and reliability of the code, comprehensive critical performance assessment and validation tests were performed. As representatives, three different transient cases with single- and multi-spool thrust and power generation engines were simulated. The transient cases range from operating with a prescribed fuel schedule, to extreme load changes, to generator and turbine shut down.

Congestion Management Systems: Review of Current Practices.

DOT National Transportation Integrated Search

2004-10-31

National parks roads and parkways integrate highway engineering and landscape architecture in their designs to provide access to recreational areas, and to provide scenic recreational travel opportunities. Typically the engineering challenge is to bu...

The Personal Computer in Mechanical Engineering Thermodynamics Courses.

ERIC Educational Resources Information Center

Romer, I. C., Jr.; Balmer, R. T.

1986-01-01

Describes experiences over several semesters with microcomputers in a mechanical engineering applied thermodynamics course. Includes course objectives, computer assignment structure, typical assignments, prewritten versus student-written software, and other topic areas. (JN)

UAF Space Systems Engineering Program: Engaging Students through an Apprenticeship Model

NASA Astrophysics Data System (ADS)

Thorsen, D.

2017-12-01

Learning by doing has been the mantra of engineering education for decades, however, the constraints of semester length courses limits the types and size of experiences that can be offered to students. The Space Systems Engineering Program (SSEP) at the University of Alaska Fairbanks provides interdisciplinary engineering and science students with hands-on experience in all aspects of space systems engineering through a design, build, launch paradigm applied to balloon and rocket payloads and small satellites. The program is structured using an apprenticeship model such that students, freshmen through graduate, can participate in multi-year projects thereby gaining experiences appropriate to their level in college. Students enter the lab in a trainee position and receive training on lab processes and design software. Depending on the student's interests they learn how to use specific lab equipment and software design tools. Trainees provide support engineering under guidance of an upper classman. As the students' progress in their degree program and gain more expertise, they typically become part of a specific subsystem team, where they receive additional training in developing design documents and in writing requirements and test documents, and direct their efforts to meeting specific objectives. By the time the student reaches their senior year, they have acquired the leadership role for a specific subsystem and/or a general leadership role in the lab. If students stay to pursue graduate degrees, they assume the responsibility of training and mentoring other undergraduates in their areas of expertise. Throughout the program upper class students mentor the newer students. The Space Systems Engineering Program strives to reinforce a student's degree program through these large scale projects that place engineering in context.

42. ARAIII Prototype assembly and evaluation building ARA630 interior. Typical ...

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

42. ARA-III Prototype assembly and evaluation building ARA-630 interior. Typical view room partitions. Ineel photo no. 3-28. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

19. View northwest of Tropic Chamber reciprocal compressors (typical), in ...

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

19. View northwest of Tropic Chamber reciprocal compressors (typical), in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

Trends and Issues in Fuzzy Control and Neuro-Fuzzy Modeling

NASA Technical Reports Server (NTRS)

Chiu, Stephen

1996-01-01

Everyday experience in building and repairing things around the home have taught us the importance of using the right tool for the right job. Although we tend to think of a 'job' in broad terms, such as 'build a bookcase,' we understand well that the 'right job' associated with each 'right tool' is typically a narrowly bounded subtask, such as 'tighten the screws.' Unfortunately, we often lose sight of this principle when solving engineering problems; we treat a broadly defined problem, such as controlling or modeling a system, as a narrow one that has a single 'right tool' (e.g., linear analysis, fuzzy logic, neural network). We need to recognize that a typical real-world problem contains a number of different sub-problems, and that a truly optimal solution (the best combination of cost, performance and feature) is obtained by applying the right tool to the right sub-problem. Here I share some of my perspectives on what constitutes the 'right job' for fuzzy control and describe recent advances in neuro-fuzzy modeling to illustrate and to motivate the synergistic use of different tools.

Recent Developments Of Optical Fiber Sensors For Automotive Use

NASA Astrophysics Data System (ADS)

Sasayama, Takao; Oho, Shigeru; Kuroiwa, Hiroshi; Suzuki, Seikoo

1987-12-01

Optical fiber sensing technologies are expected to apply for many future electronic control systems in automobiles, because of their original outstanding features, such as high noise immunity, high heat resistance, and flexible light propagation paths which can be applicable to measure the movements and directions of the mobiles. In this paper, two typical applications of fiber sensing technologies in automobiles have been described in detail. The combustion flame detector is one of the typical applications of a fiber spectroscopic technology which utilizes the feature of high noise and heat resistibility and remote sensibility. Measurements of engine combustion conditions, such as the detonation, the combustion initiation, and the air-fuel ratio, have been demonstrated in an experimental fiber sensing method. Fiber interferometers, such as a fiber gyroscope, have a lot of possibilities in future mobile applications because they are expandable to many kinds of measurements for movements and physical variables. An optical fiber gyroscope utilizing the single polarized optical fiber and optical devices has been developed. Quite an accurate measurement of vehicle position was displayed on a prototype navigation system which installed the fiber gyroscope as a rotational speed sensor.

14 CFR 29.1011 - Engines: general.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engines: general. 29.1011 Section 29.1011... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1011 Engines: general. (a) Each engine... the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin...

14 CFR 27.1011 - Engines: General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engines: General. 27.1011 Section 27.1011... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1011 Engines: General. (a) Each engine must... maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate...

14 CFR 27.1011 - Engines: General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engines: General. 27.1011 Section 27.1011... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1011 Engines: General. (a) Each engine must... maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate...

14 CFR 27.1011 - Engines: General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engines: General. 27.1011 Section 27.1011... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1011 Engines: General. (a) Each engine must... maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate...

14 CFR 27.1011 - Engines: General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engines: General. 27.1011 Section 27.1011... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1011 Engines: General. (a) Each engine must... maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate...

14 CFR 29.1011 - Engines: general.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engines: general. 29.1011 Section 29.1011... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1011 Engines: general. (a) Each engine... the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin...

14 CFR 29.1011 - Engines: general.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engines: general. 29.1011 Section 29.1011... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1011 Engines: general. (a) Each engine... the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin...

14 CFR 27.1011 - Engines: General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engines: General. 27.1011 Section 27.1011... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1011 Engines: General. (a) Each engine must... maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate...

14 CFR 29.1011 - Engines: general.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engines: general. 29.1011 Section 29.1011... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1011 Engines: general. (a) Each engine... the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin...

14 CFR 29.1011 - Engines: general.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engines: general. 29.1011 Section 29.1011... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1011 Engines: general. (a) Each engine... the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin...

Biomedical engineering education through global engineering teams.

PubMed

Scheffer, C; Blanckenberg, M; Garth-Davis, B; Eisenberg, M

2012-01-01

Most industrial projects require a team of engineers from a variety of disciplines. The team members are often culturally diverse and geographically dispersed. Many students do not acquire sufficient skills from typical university courses to function efficiently in such an environment. The Global Engineering Teams (GET) programme was designed to prepare students such a scenario in industry. This paper discusses five biomedical engineering themed projects completed by GET students. The benefits and success of the programme in educating students in the field of biomedical engineering are discussed.