First-Year Engineering Students' Views of the Nature of Engineering: Implications for Engineering Programmes

ERIC Educational Resources Information Center

Karatas, F. Ö.; Bodner, G. M.; Unal, Suat

2016-01-01

A study was conducted on the views of the nature of engineering held by 114 first-year engineering majors; the study built on prior work on views of the nature of science held by students, their instructors, and the general public. Open-coding analysis of responses to a 12-item questionnaire suggested that the participants held tacit beliefs that…

Orbit Transfer Vehicle (OTV) engine phase A study

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1978-01-01

Requirements for the orbit transfer vehicle engine were examined. Engine performance/weight sensitivities, the effect of a service life of 300 start/shutdown cycles between overalls on the maximum engine operating pressure, and the sensitivity of the engine design point (i.e., thrust chamber pressure and nozzle area ratio) to the performance requirements specified are among the factors studied. Preliminary engine systems analyses were conducted on the stage combustion, expander, and gas generator engine cycles. Hydrogen and oxygen pump discharge pressure requirements are shown for various engine cycles. Performance of the engine cycles is compared.

Health effects of inhaled gasoline engine emissions.

PubMed

McDonald, Jacob D; Reed, Matthew D; Campen, Matthew J; Barrett, Edward G; Seagrave, JeanClare; Mauderly, Joe L

2007-01-01

Despite their prevalence in the environment, and the myriad studies that have shown associations between morbidity or mortality with proximity to roadways (proxy for motor vehicle exposures), relatively little is known about the toxicity of gasoline engine emissions (GEE). We review the studies conducted on GEE to date, and summarize the findings from each of these studies. While there have been several studies, most of the studies were conducted prior to 1980 and thus were not conducted with contemporary engines, fuels, and driving cycles. In addition, many of the biological assays conducted during those studies did not include many of the assays that are conducted on contemporary inhalation exposures to air pollutants, including cardiovascular responses and others. None of the exposures from these earlier studies were characterized at the level of detail that would be considered adequate today. A recent GEE study was conducted as part of the National Environmental Respiratory Center (www.nercenter.org). In this study several in-use mid-mileage General Motors (Chevrolet S-10) vehicles were purchased and utilized for inhalation exposures. An exposure protocol was developed where engines were operated with a repeating California Unified Driving Cycle with one cold start per day. Two separate engines were used to provide two cold starts over a 6-h inhalation period. The exposure atmospheres were characterized in detail, including detailed chemical and physical analysis of the gas, vapor, and particle phase. Multiple rodent biological models were studied, including general toxicity and inflammation (e.g., serum chemistry, lung lavage cell counts/differentials, cytokine/chemokine analysis, histopathology), asthma (adult and in utero exposures with pulmonary function and biochemical analysis), cardiovascular effects (biochemical and electrocardiograph changes in susceptible rodent models), and susceptibility to infection (Pseudomonas bacteria challenge). GEE resulted in significant biological effects for upregulation of MIP-2, clearance of Pseudomonas bacteria, development of allergic response after in utero exposure, and cardiovascular indicators of vasoconstriction, oxidant stress, and damage.

Dual throat engine design for a SSTO launch vehicle

NASA Technical Reports Server (NTRS)

Obrien, C. J.; Salmon, J. W.

1980-01-01

A propulsion system analysis of a dual fuel, dual throat engine for launch vehicle application was conducted. Basic dual throat engine characterization data are presented to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined. Dual throat engine performance, envelope, and weight parametric data were generated over the parametric range of thrust from 890 to 8896 KN (200K to 2M lb-force), chamber pressure from 6.89 million to 34.5 million N/sq m (1000 to 5000 psia) thrust ratio from 1.2 to 5, and a range of mixture ratios for the two tripropellant combinations: LO2/RP-1 + LH2 and LO2/LCH4 + LH2. The results of the study indicate that the dual fuel dual throat engine is a viable single stage to orbit candidate.

ENGINEERING MANPOWER BULLETIN NUMBER 9.

ERIC Educational Resources Information Center

ALDEN, JOHN D.

DESIGNED TO INFORM LEADERS IN INDUSTRY, GOVERNMENT, AND EDUCATION, WHOSE RESPONSIBILITY INCLUDES AWARENESS OF ENGINEERING MANPOWER DEVELOPMENTS, THIS BULLETIN REPORTS A STUDY CONDUCTED BY THE ENGINEERING MANPOWER COMMISSION OF ENGINEERS IN THE ARMED SERVICES. THE WORK OF THE COMMISSION IS TO ASSURE THE MOST EFFECTIVE UTILIZATION OF ENGINEERING…

Tunable thermal conductivity via domain structure engineering in ferroelectric thin films: A phase-field simulation

DOE PAGES

Wang, Jian -Jun; Wang, Yi; Ihlefeld, Jon F.; ...

2016-04-06

Effective thermal conductivity as a function of domain structure is studied by solving the heat conduction equation using a spectral iterative perturbation algorithm in materials with inhomogeneous thermal conductivity distribution. Using this proposed algorithm, the experimentally measured effective thermal conductivities of domain-engineered {001} p-BiFeO 3 thin films are quantitatively reproduced. In conjunction with two other testing examples, this proposed algorithm is proven to be an efficient tool for interpreting the relationship between the effective thermal conductivity and micro-/domain-structures. By combining this algorithm with the phase-field model of ferroelectric thin films, the effective thermal conductivity for PbZr 1-xTi xO 3 filmsmore » under different composition, thickness, strain, and working conditions is predicted. It is shown that the chemical composition, misfit strain, film thickness, film orientation, and a Piezoresponse Force Microscopy tip can be used to engineer the domain structures and tune the effective thermal conductivity. Furthermore, we expect our findings will stimulate future theoretical, experimental and engineering efforts on developing devices based on the tunable effective thermal conductivity in ferroelectric nanostructures.« less

Tunable thermal conductivity via domain structure engineering in ferroelectric thin films: A phase-field simulation

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

Wang, Jian -Jun; Wang, Yi; Ihlefeld, Jon F.

Effective thermal conductivity as a function of domain structure is studied by solving the heat conduction equation using a spectral iterative perturbation algorithm in materials with inhomogeneous thermal conductivity distribution. Using this proposed algorithm, the experimentally measured effective thermal conductivities of domain-engineered {001} p-BiFeO 3 thin films are quantitatively reproduced. In conjunction with two other testing examples, this proposed algorithm is proven to be an efficient tool for interpreting the relationship between the effective thermal conductivity and micro-/domain-structures. By combining this algorithm with the phase-field model of ferroelectric thin films, the effective thermal conductivity for PbZr 1-xTi xO 3 filmsmore » under different composition, thickness, strain, and working conditions is predicted. It is shown that the chemical composition, misfit strain, film thickness, film orientation, and a Piezoresponse Force Microscopy tip can be used to engineer the domain structures and tune the effective thermal conductivity. Furthermore, we expect our findings will stimulate future theoretical, experimental and engineering efforts on developing devices based on the tunable effective thermal conductivity in ferroelectric nanostructures.« less

Remote lift fan study program, volume 4

NASA Technical Reports Server (NTRS)

1973-01-01

A study program to select and conduct preliminary design of advanced technology lift fan systems to meet low noise goals of future V/STOL transport aircraft is discussed. This volume contains results of additional studies conducted to support the main preliminary design effort done under the Remote Lift Fan Study Program (Contract NAS3-14406) and a companion effort, the Integral Lift Fan Study (NAS3-14404). These results cover engine emission study, a review of existing engines for research aircraft application and support data for aircraft studies.

Alleviation of Facility/Engine Interactions in an Open-Jet Scramjet Test Facility

NASA Technical Reports Server (NTRS)

Albertson, Cindy W.; Emami, Saied

2001-01-01

Results of a series of shakedown tests to eliminate facility/engine interactions in an open-jet scramjet test facility are presented. The tests were conducted with the NASA DFX (Dual-Fuel eXperimental scramjet) engine in the NASA Langley Combustion Heated Scramjet Test Facility (CHSTF) in support of the Hyper-X program, The majority of the tests were conducted at a total enthalpy and pressure corresponding to Mach 5 flight at a dynamic pressure of 734 psf. The DFX is the largest engine ever tested in the CHSTF. Blockage, in terms of the projected engine area relative to the nozzle exit area, is 81% with the engine forebody leading edge aligned with the upper edge of the facility nozzle such that it ingests the nozzle boundary layer. The blockage increases to 95% with the engine forebody leading edge positioned 2 in. down in the core flow. Previous engines successfully tested in the CHSTF have had blockages of no more than 51%. Oil flow studies along with facility and engine pressure measurements were used to define flow behavior. These results guided modifications to existing aeroappliances and the design of new aeroappliances. These changes allowed fueled tests to be conducted without facility interaction effects in the data with the engine forebody leading edge positioned to ingest the facility nozzle boundary layer. Interaction effects were also reduced for tests with the engine forebody leading edge positioned 2 in. into the core flow, however some interaction effects were still evident in the engine data. A new shroud and diffuser have been designed with the goal of allowing fueled tests to be conducted with the engine forebody leading edge positioned in the core without facility interaction effects in the data. Evaluation tests of the new shroud and diffuser will be conducted once ongoing fueled engine tests have been completed.

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.

Supersonic through-flow fan assessment

NASA Technical Reports Server (NTRS)

Kepler, C. E.; Champagne, G. A.

1988-01-01

A study was conducted to assess the performance potential of a supersonic through-flow fan engine for supersonic cruise aircraft. It included a mean-line analysis of fans designed to operate with in-flow velocities ranging from subsonic to high supersonic speeds. The fan performance generated was used to estimate the performance of supersonic fan engines designed for four applications: a Mach 2.3 supersonic transport, a Mach 2.5 fighter, a Mach 3.5 cruise missile, and a Mach 5.0 cruise vehicle. For each application an engine was conceptualized, fan performance and engine performance calculated, weight estimates made, engine installed in a hypothetical vehicle, and mission analysis was conducted.

Orbital Transfer Vehicle (OTV) engine study. Phase A: Extension

NASA Technical Reports Server (NTRS)

Sobin, A. J.

1980-01-01

The current Phase A-Extension of the OTV engine study program aims to provide additional expander and staged combustion cycle data that will lead to design definition of the OTV engine. The proposed program effort seeks to optimize the expander cycle engine concept (consistent with identified OTV engine requirements), investigate the feasibility of kitting the staged combustion cycle engine to provide extended thrust operation, and conduct in-depth analysis of development risk, crew safety, and reliability for both cycles. Additional tasks address the costing of a 10/K thrust expander cycle engine and support of OTV systems study contractors.

Anxiety among Engineering Students in a Graduate EFL Classroom

ERIC Educational Resources Information Center

Samoilova, Valeriia; Thanh, Vo Duy; Wilang, Jeffrey Dawala

2017-01-01

This article reports the descriptive results of foreign language anxiety experiences of engineering students in a top-ranked research university in Thailand. Although numerous studies have been conducted in the past years about English language anxiety, few studies have reported anxiety situations specific to Thai engineering graduate students in…

Engineering Employment Characteristics. Engineering Education and Practice in the United States.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Engineering and Technical Systems.

This panel report was prepared as part of the study of engineering education and practice conducted under the guidance of the National Research Council's Committee on the Education and Utilization of the Engineer. The panel's goal was to provide a data base that describes the engineering work force, its main activities, capabilities, and principal…

Engineering Infrastructure Diagramming and Modeling. Engineering Education and Practice in The United States.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Engineering and Technical Systems.

This report forms an integral part of a study conducted by the Committee on the Education and Utilization of the Engineer, under the auspices of the National Research Council. Five major tasks undertaken by the panel were: (1) defining engineering; (2) determining influences on the engineering community, including external influences and internal…

Design type air engine Di Pietro

NASA Astrophysics Data System (ADS)

Zwierzchowski, Jaroslaw

The article presents a pneumatic engine constructed by Angelo Di Pietro. 3D solid models of pneumatic engine components were presented therein. A directional valve is a key element of the control system. The valve functions as a camshaft distributing air to particular engine chambers. The construction designed by Angelo Di Pietro is modern and innovative. A pneumatic engine requires low pressure to start rotary movement. With the use of CFD software, the fields of velocity vectors' distribution were determined. Moreover, the author determined the distribution of pressure values in engine inlet and outlet channels. CFD model studies on engine operation were conducted for chosen stages of operating cycles. On the basis of simulation tests that were conducted, the values of flow rates for the engine were determined. The distribution of pressure values made it possible to evaluate the torque value on the rotating shaft.

Predicting Engineering Student Attrition Risk Using a Probabilistic Neural Network and Comparing Results with a Backpropagation Neural Network and Logistic Regression

ERIC Educational Resources Information Center

Mason, Cindi; Twomey, Janet; Wright, David; Whitman, Lawrence

2018-01-01

As the need for engineers continues to increase, a growing focus has been placed on recruiting students into the field of engineering and retaining the students who select engineering as their field of study. As a result of this concentration on student retention, numerous studies have been conducted to identify, understand, and confirm…

Ethics in Engineering: Student Perceptions and Their Professional Identity Development

ERIC Educational Resources Information Center

Stappenbelt, Brad

2013-01-01

Professional ethics instruction in engineering is commonly conducted by examining case studies in light of the code of conduct of a suitable professional body. Although graphical presentations of spectacular failures, sobering stories of the repercussions and the solid framework provided by the tenets of a code of ethics may leave a lasting…

Energy efficient engine: Preliminary design and integration studies

NASA Technical Reports Server (NTRS)

Johnston, R. P.; Hirschkron, R.; Koch, C. C.; Neitzel, R. E.; Vinson, P. W.

1978-01-01

Parametric design and mission evaluations of advanced turbofan configurations were conducted for future transport aircraft application. Economics, environmental suitability and fuel efficiency were investigated and compared with goals set by NASA. Of the candidate engines which included mixed- and separate-flow, direct-drive and geared configurations, an advanced mixed-flow direct-drive configuration was selected for further design and evaluation. All goals were judged to have been met except the acoustic goal. Also conducted was a performance risk analysis and a preliminary aerodynamic design of the 10 stage 23:1 pressure ratio compressor used in the study engines.

Self-Perceptions of Interpersonal, Intrapersonal, and Leadership Skills among Recent Engineering Graduates: A Qualitative Study

ERIC Educational Resources Information Center

Watson, Fallon E.

2013-01-01

This study describes the communication-specific soft skills that recent engineering graduates from Accreditation Board for Engineering and Technology (ABET) accredited universities in the state of Kentucky report they use at work. Utilizing a basic interpretive qualitative approach in-depth semi-structured interviews were conducted to obtain the…

A Survey of Computer Use in Associate Degree Programs in Engineering Technology.

ERIC Educational Resources Information Center

Cunningham, Pearley

As part of its annual program review process, the Department of Engineering Technology at the Community College of Allegheny County, in Pennsylvania, conducted a study of computer usage in community college engineering technology programs across the nation. Specifically, the study sought to determine the types of software, Internet access, average…

Understanding the Leaky Engineering Pipeline: Motivation and Job Adaptability of Female Engineers

ERIC Educational Resources Information Center

Saraswathiamma, Manjusha Thekkedathu

2010-01-01

This dissertation is a mixed-method study conducted using qualitative grounded theory and quantitative survey and correlation approaches. This study aims to explore the motivation and adaptability of females in the engineering profession and to develop a theoretical framework for both motivation and adaptability issues. As a result, this study…

Usability engineering for augmented reality: employing user-based studies to inform design.

PubMed

Gabbard, Joseph L; Swan, J Edward

2008-01-01

A major challenge, and thus opportunity, in the field of human-computer interaction and specifically usability engineering is designing effective user interfaces for emerging technologies that have no established design guidelines or interaction metaphors or introduce completely new ways for users to perceive and interact with technology and the world around them. Clearly, augmented reality is one such emerging technology. We propose a usability engineering approach that employs user-based studies to inform design, by iteratively inserting a series of user-based studies into a traditional usability engineering lifecycle to better inform initial user interface designs. We present an exemplar user-based study conducted to gain insight into how users perceive text in outdoor augmented reality settings and to derive implications for design in outdoor augmented reality. We also describe lessons learned from our experiences conducting user-based studies as part of the design process.

A Study to Determine the Basic Science and Mathematics Topics Most Needed by Engineering Technology Graduates of Wake Technical Institute in Performing Job Duties.

ERIC Educational Resources Information Center

Edwards, Timothy I.; Roberson, Clarence E., Jr.

A survey of 470 graduates of the six engineering technology programs at Wake Technical Institute--Architectural, Chemical, Civil Engineering, Computer, Electronic Engineering, and Industrial Engineering Technologies--and 227 of their employers was conducted in October, 1979, to determine the science and mathematics topics most needed by…

The Engineering Design Process: Conceptions along the Learning-To-Teach Continuum

ERIC Educational Resources Information Center

Iveland, Ashley

2017-01-01

In this study, I sought to identify differences in the views and understandings of engineering design among individuals along the learning-to-teach continuum. To do so, I conducted a comprehensive review of literature to determine the various aspects of engineering design described in the fields of professional engineering and engineering…

Advanced blade tip seal system, volume 2

NASA Technical Reports Server (NTRS)

Zelahy, J. W.; Fairbanks, N. P.

1982-01-01

The results of the endurance and performance engine tests conducted on monocrystal/abrasive-tipped CF6-50 Stage 1 HPT blades fabricated in Task VII of MATE Project 3 are presented. Two engine tests are conducted. The endurance engine test is conducted for 1000 C cycles. The performance engine test is conducted on a variable cycle core engine. Posttest evaluation and analyses of the blades and shrouds included visual, dimensional, and destructive evaluations.

The Engineering Design Process: Conceptions Along the Learning-to-Teach Continuum

NASA Astrophysics Data System (ADS)

Iveland, Ashley

In this study, I sought to identify differences in the views and understandings of engineering design among individuals along the learning-to-teach continuum. To do so, I conducted a comprehensive review of literature to determine the various aspects of engineering design described in the fields of professional engineering and engineering education. Additionally, I reviewed literature on the methods used in teaching engineering design at the secondary (grade 7-12) level - to describe the various models used in classrooms, even before the implementation of the Next Generation Science Standards (NGSS Lead States, 2013). Last, I defined four groups along the learning-to-teach continuum: prospective, preservice, and practicing teachers, as well as teacher educators. The context of this study centered around a California public university, including an internship program where undergraduates engaged with practicing mentor teachers in science and engineering teaching at local high schools, and a teacher education program where secondary science preservice teachers and the teacher educators who taught them participated. Interviews were conducted with all participants to gain insights into their views and understandings of engineering design. Prospective and preservice teachers were interviewed multiple times throughout the year and completed concept maps of the engineering design process multiple times as well; practicing teachers and teacher educators were interviewed once. Three levels of analyses were conducted. I identified 30 aspects of engineering discussed by participants. Through phenomenographic methods, I also constructed six conceptual categories for engineering design to organize those aspects most commonly discussed. These categories were combined to demonstrate a participant's view of engineering design (e.g., business focused, human centered, creative, etc.) as well as their complexity of understanding of engineering design overall (the more categories their ideas fit within, the more complex their understanding was thought to be). I found that the most commonly referenced aspects of engineering design were in line with the three main dimensions described in the Next Generation Science Standards (NGSS Lead States, 2013). I also found that the practicing teacher participants overall conveyed the most complex and integrated understandings of engineering design, with the undergraduate, prospective teachers not far behind. One of the most important factors related to a more integrated understanding of engineering design was having formal engineering experience, especially in the form of conducting engineering research or having been a professional engineer. Further, I found that female participants were more likely than their male counterparts to view engineering as having a human element--recognizing the need to collaborate with others throughout the process and the need to think about the potential user of the product the engineer is solving the problem for. These findings suggest that prior experience with engineering, and not experience in the classroom or with engineering education, tends to lead to a deeper, more authentic view of engineering. Finally, I close with a discussion of the overall findings, limitations of the study, potential implications, and future work.

Flexible 2D RF Nanoelectronics based on Layered Semiconductor Transistor (NBIT III)

DTIC Science & Technology

2016-11-11

Experimental and computational studies in multidisciplinary fields of electrical, mechanical engineering , and materials science were conducted to achieve...plan for this project. Experimental and computational studies in multidisciplinary fields of electrical, mechanical engineering , and materials...electrostatic or physisorption gating, defect engineering , and substitutional doping during the growth. These methods result in uniform doping or composition

A Case Study: Teaching Engineering Concepts in Science. Research in Engineering and Technology Education

ERIC Educational Resources Information Center

Stricker, David R.

2010-01-01

This study was conducted to describe a teacher developed high school engineering course, to identify teaching strategies used in the process of delivering math and science literacy through this course, to identify challenges and constraints that occurred during its development and delivery, and to describe the strategies that were used to overcome…

A study of bird ingestions into large high bypass ratio turbine aircraft engines

DOT National Transportation Integrated Search

1984-09-01

From May 1981 to June 1983, the Federal Aviation Administration (FAA) Technical Center : conducted a detailed study of bird ingestions into large high bypass ratio turbine : aircraft engines. The worldwide study covered over 2.7 million operations by...

Engineering studies in support of the development of high-speed track geometry specifications

DOT National Transportation Integrated Search

1997-03-01

The Federal Railroad Administration has been directing engineering studies to support the development of high speed track geometry standards. These standards are intended to cover train operating speeds from 110 mph to 200 mph. The studies conducted ...

Computer Science and Engineering Students Addressing Critical Issues Regarding Gender Differences in Computing: A Case Study

ERIC Educational Resources Information Center

Tsagala, Evrikleia; Kordaki, Maria

2008-01-01

This study focuses on how Computer Science and Engineering Students (CSESs) of both genders address certain critical issues for gender differences in the field of Computer Science and Engineering (CSE). This case study is based on research conducted on a sample of 99 Greek CSESs, 43 of which were women. More specifically, these students were asked…

PLTW and Epics-High: Curriculum Comparisons to Support Problem Solving in the Context of Engineering Design. Research in Engineering and Technology Education

ERIC Educational Resources Information Center

Kelley, Todd; Brenner, Daniel C.; Pieper, Jon T.

2010-01-01

A comparative study was conducted to compare two approaches to engineering design curriculum between different schools (inter-school) and between two curricular approaches, "Project Lead the Way" (PLTW) and "Engineering Projects in Community Service" (EPIC High) (inter-curricular). The researchers collected curriculum…

The Role of Oral Communicative Tasks (OCT) in Developing the Spoken Proficiency of Engineering Students

ERIC Educational Resources Information Center

Shantha, S.; Mekala, S.

2017-01-01

The mastery of speaking skills in English has become a major requisite in engineering industry. Engineers are expected to possess speaking skills for executing their routine activities and career prospects. The article focuses on the experimental study conducted to improve English spoken proficiency of Indian engineering students using task-based…

Conceptual design studies and experiments related to cavity exhaust systems for nuclear light bulb configurations

NASA Technical Reports Server (NTRS)

Kendall, J. S.; Stoeffler, R. C.

1972-01-01

Investigations of various phases of gaseous nuclear rocket technology have been conducted. The principal research efforts have recently been directed toward the closed-cycle, vortex-stabilized nuclear light bulb engine and toward a small-scale fissioning uranium plasma experiment that could be conducted in the Los Alamos Scientific Laboratory's Nuclear Furnace. The engine concept is based on the transfer of energy by thermal radiation from gaseous fissioning uranium, through a transparent wall, to hydrogen propellant. The reference engine configuration is comprised of seven unit cavities, each having its own fuel transparent wall and propellant duct. The basic design of the engine is described. Subsequent studies performed to supplement and investigate the basic design are reported. Summaries of other nuclear light bulb research programs are included.

Piston Temperatures in an Air-Cooled Engine for Various Operating Conditions

NASA Technical Reports Server (NTRS)

Manganiello, Eugene J

1940-01-01

As part of a program for the study of piston cooling, this report presents the results of tests conducted on a single-cylinder, air-cooled, carburetor engine to determine the effect of engine operating conditions on the temperatures at five locations on the piston.

Two Approaches to Engineering Design:Observations in sTEm Education

ERIC Educational Resources Information Center

Kelley, Todd R.; Brenner, Daniel C.; Pieper, Jon T.

2010-01-01

A comparative study was conducted to compare two approaches to engineering design curriculum across different schools (inter-school) and across two curricula "Project Lead the Way and Engineering Projects in Community Service" (inter-curricula). The researchers collected curricula material including handouts, lesson plans, guides,…

Advanced expander test bed engine

NASA Technical Reports Server (NTRS)

Mitchell, J. P.

1992-01-01

The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

Non-Markovian Investigation of an Autonomous Quantum Heat Engine

NASA Astrophysics Data System (ADS)

Goyal, Ketan

A systematic study of a quantum heat engine is presented in this thesis. In particular, we study heat conduction through a two-two level composite system, which is then connected to a photon cavity to extract work, forming an autonomous quantum heat engine. The question as to what extent quantum effects such as quantum coherence and correlations impact thermodynamic properties of such a system is addressed. The investigated heat engine has been previously studied using the popular Born-Markovian quantum master equation under weak internal coupling approximation. However, we show that the used approach is quite limited in addressing such problems as it is incapable of correctly accounting for the quantum effects. By using a non-Markovian approach involving hierarchical equations of motion, we show that quantum coherence and correlations between system and environments play a significant role in energy transfer processes of heat conduction and work.

Experimental Evaluation of Inlet Distortion on an Ejector Powered Hybrid Wing Body at Take-off and Landing Conditions

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Shea, Patrick R.; Flamm, Jeffrey D.; Schuh, Michael; James, Kevin D.; Sexton, Matthew R.; Tompkins, Daniel M.; Beyar, Michael D.

2016-01-01

As part of the NASA Environmentally Responsible Aircraft project, an ultra high bypass ratio engine integration on a hybrid wing body demonstration was planned. The goal was to include engine and airframe integration concepts that reduced fuel consumption by at least 50% while still reducing noise 42 db cumulative on the ground. Since the engines would be mounted on the upper surface of the aft body of the aircraft, the inlets may be susceptible to vortex ingestion from the wing leading edge at high angles of attack and sideslip, and separated wing/body flow. Consequently, experimental and computational studies were conducted to collect flow surveys useful for characterizing engine operability. The wind tunnel tests were conducted at two NASA facilities, the 14- by 22-foot at NASA Langley and the 40- by 80-foot at NASA Ames Research Center. The test results included in this paper show that the distortion and pressure recovery levels were acceptable for engine operability. The CFD studies conducted to compare to experimental data showed excellent agreement for the angle of attacks examined, although failed to match the low speed experimental data at high sideslip angles.

Evaluation of Flowable Fill Surface Performance

DTIC Science & Technology

2016-11-01

Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR...33 viii Preface This study was conducted for the U.S. Air Force’s (USAF) pavement evaluation teams, contingency readiness groups, base civil...engineers, major command pavement engineers, Rapid Engineer Deployable Heavy Operational Repair Squadron Engineer (RED HORSE) squadrons, and Prime Base

Why They Stay: Women Persisting in US Engineering Careers

ERIC Educational Resources Information Center

Buse, Kathleen; Bilimoria, Diana; Perelli, Sheri

2013-01-01

Purpose: Women remain dramatically underrepresented in the engineering profession and far fewer women than men persist in the field. This study aims to identify individual and contextual factors that distinguish women who persist in engineering careers in the US. Design/methodology/approach: Qualitative research was conducted based on…

Energy efficient engine flight propulsion system: Aircraft/engine integration evaluation

NASA Technical Reports Server (NTRS)

Patt, R. F.

1980-01-01

Results of aircraft/engine integration studies conducted on an advanced flight propulsion system are reported. Economic evaluations of the preliminary design are included and indicate that program goals will be met. Installed sfc, DOC, noise, and emissions were evaluated. Aircraft installation considerations and growth were reviewed.

Civil Engineering Technology Needs Assessment.

ERIC Educational Resources Information Center

Oakland Community Coll., Farmington, MI. Office of Institutional Planning and Analysis.

In 1991, a study was conducted by Oakland Community College (OCC) to evaluate the need for a proposed Civil Engineering Technology program. An initial examination of the literature focused on industry needs and the job market for civil engineering technicians. In order to gather information on local area employers' hiring practices and needs, a…

Energy efficient engine flight propulsion system: Aircraft/engine integration evaluation

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

Patt, R.F.

Results of aircraft/engine integration studies conducted on an advanced flight propulsion system are reported. Economic evaluations of the preliminary design are included and indicate that program goals will be met. Installed sfc, DOC, noise, and emissions were evaluated. Aircraft installation considerations and growth were reviewed.

Busy test week

NASA Image and Video Library

2012-11-08

NASA engineer Andy Guymon studies data in the E-3 Test Stand Control Center at John C. Stennis Space Center during testing of NASA's Project Morpheus engine. Nov. 8. The test of the liquid oxygen, liquid methane engine was one of 27 conducted in Stennis' E Test Complex the week of Nov. 5.

COBRA System Engineering Processes to Achieve SLI Strategic Goals

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2003-01-01

The COBRA Prototype Main Engine Development Project was an endeavor conducted as a joint venture between Pratt & Whitney and Aerojet to conduct risk reduction in LOX/LH2 main engine technology for the NASA Space Launch Initiative (SLI). During the seventeen months of the project (April 2001 to September 2002), approximately seventy reviews were conducted, beginning with the Engine Systems Requirements Review (SRR) and ending with the Engine Systems Interim Design Review (IDR). This paper discusses some of the system engineering practices used to support the reviews and the overall engine development effort.

23 CFR 627.9 - Conducting a VE analysis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS VALUE ENGINEERING § 627.9 Conducting a VE analysis. (a) A VE analysis should be conducted as early as practicable in... that consider alternative construction materials; and (2) Be conducted based on: (i) An engineering and...

23 CFR 627.9 - Conducting a VE analysis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS VALUE ENGINEERING § 627.9 Conducting a VE analysis. (a) A VE analysis should be conducted as early as practicable in... that consider alternative construction materials; and (2) Be conducted based on: (i) An engineering and...

CF6-6D engine short-term performance deterioration

NASA Technical Reports Server (NTRS)

Kramer, W. H.; Paas, J. E.; Smith, J. J.; Wulf, R. H.

1980-01-01

Studies conducted as part of the NASA-Lewis CF6 jet engine diagnostics program are summarized. An 82-engine sample of DC-10-10 aircraft engine checkout data that were gathered to define the extent and magnitude of CF6-6D short term performance deterioration were analyzed. These data are substantiated by the performance testing and analytical teardown of CF6-6D short term deterioration engine serial number (ESN) 451507.

Development of Supersonic Vehicle for Demonstration of a Precooled Turbojet Engine

NASA Astrophysics Data System (ADS)

Sawai, Shujiro; Fujita, Kazuhisa; Kobayashi, Hiroaki; Sakai, Shin'ichiro; Bando, Nobutaka; Kadooka, Shouhei; Tsuboi, Nobuyuki; Miyaji, Koji; Uchiyama, Taku; Hashimoto, Tatsuaki

JAXA is developing Mach 5 hypersonic turbojet engine technology that can be applied in a future hypersonic transport. Now, Jet Engine Technology Research Center of JAXA conducts the experimental study using a 1 / 10 scale-model engine. In parallel to engine development activities, a new supersonic flight-testing vehicle for the hypersonic turbojet engine is under development since 2004. In this paper, the system configuration of the flight-testing vehicle is outlined and development status is reported.

Studying the Transient Thermal Contact Conductance Between the Exhaust Valve and Its Seat Using the Inverse Method

NASA Astrophysics Data System (ADS)

Nezhad, Mohsen Motahari; Shojaeefard, Mohammad Hassan; Shahraki, Saeid

2016-02-01

In this study, the experiments aimed at analyzing thermally the exhaust valve in an air-cooled internal combustion engine and estimating the thermal contact conductance in fixed and periodic contacts. Due to the nature of internal combustion engines, the duration of contact between the valve and its seat is too short, and much time is needed to reach the quasi-steady state in the periodic contact between the exhaust valve and its seat. Using the methods of linear extrapolation and the inverse solution, the surface contact temperatures and the fixed and periodic thermal contact conductance were calculated. The results of linear extrapolation and inverse methods have similar trends, and based on the error analysis, they are accurate enough to estimate the thermal contact conductance. Moreover, due to the error analysis, a linear extrapolation method using inverse ratio is preferred. The effects of pressure, contact frequency, heat flux, and cooling air speed on thermal contact conductance have been investigated. The results show that by increasing the contact pressure the thermal contact conductance increases substantially. In addition, by increasing the engine speed the thermal contact conductance decreases. On the other hand, by boosting the air speed the thermal contact conductance increases, and by raising the heat flux the thermal contact conductance reduces. The average calculated error equals to 12.9 %.

Reassessing the English Course Offered to Computer Engineering Students at the National School of Applied Sciences of Al-Hoceima in Morocco: An Action Research Project

ERIC Educational Resources Information Center

Dahbi, M.

2015-01-01

In computer engineering education, specific English language practices are needed to enable computer engineering students to succeed in professional settings. This study was conducted for two purposes. First, it aimed at investigating to what extent the English courses offered to computer engineering students at the National School of Applied…

Fabrication of conductive polymer-based nanofiber scaffolds for tissue engineering applications.

PubMed

Gu, Bon Kang; Kim, Min Sup; Kang, Chang Mo; Kim, Jong-Ll; Park, Sang Jun; Kim, Chun-Ho

2014-10-01

Natural and synthetic polymers, in particular those that are conductive, are of great interest in the field of tissue engineering and the pursuit of biomimetic extracellular matrix (ECM) structures for adhesion, proliferation, and differentiation of cells. In the present study, natural chitin and conductive polyaniline (PANi) blended solutions were electrospun to produce biodegradable and conductive biomimetic nanostructured scaffolds. The chitin/PANi (Chi-PANi) nanofibrous materials were characterized using field emission scanning electron microscopy, Fourier transform-infrared spectroscopy, wettability analysis, mechanical testing, and electrical conductivity measurements using a 4-point probe method. The calculated electrical conductivities of the PANi-containing nanofiber scaffolds significantly increased as the amount of PANi increased, reaching 5.21 ± 0.28 x 10(-3) S/cm for 0.3 wt% content of the conducting polymer. In addition, the viability of human mesenchymal stem cells (hMSCs) cultured on the Chi-PANi nanofiber scaffolds in vitro was found to be excellent. These results suggest that the Chi-PANi nanofiber scaffolds have great potential for use in tissue engineering applications that involve electrical stimulation.

Skills Conversion Project: Chapter 10, Ocean Engineering and Oceanography. Final Report.

ERIC Educational Resources Information Center

National Society of Professional Engineers, Washington, DC.

In order to determine the potential utilization of displaced aerospace and defense technical professionals in oceanography and ocean engineering, a study of ocean-oriented industry in Florida and Southern California was conducted by The National Society of Professional Engineers for the U.S. Department of Labor. After recent consolidation, this…

Enhancing the Undergraduate Industrial Engineering Curriculum: Defining Desired Characteristics and Emerging Topics

ERIC Educational Resources Information Center

Eskandari, Hamidreza; Sala-Diakanda, Serge; Furterer, Sandra; Rabelo, Luis; Crumpton-Young, Lesia; Williams, Kent

2007-01-01

Purpose: This paper aims to present the results of an initial research study conducted to identify the desired professional characteristics of an industrial engineer with an undergraduate degree and the emerging topic areas that should be incorporated into the curriculum to prepare industrial engineering (IE) graduates for the future workforce.…

Practicing Engineers' Perspective on Mathematics and Mathematics Education in College

ERIC Educational Resources Information Center

Tosmur-Bayazit, Nermin; Ubuz, Behiye

2013-01-01

This paper reports on a qualitative study focusing on engineers' point of view in regard to university mathematics and mathematics education. An individual interview was conducted with three electrical and two mechanical engineers between the ages of 25-40, all engaged in successful careers. The subjects were requested to reflect upon themselves…

An Examination of Computer Engineering Students' Perceptions about Asynchronous Discussion Forums

ERIC Educational Resources Information Center

Ozyurt, Ozcan; Ozyurt, Hacer

2013-01-01

This study was conducted in order to reveal the usage profiles and perceptions of Asynchronous Discussion Forums (ADFs) of 126 computer engineering students from the Computer Engineering Department in a university in Turkey. By using a mixed methods research design both quantitative and qualitative data were collected and analyzed. Research…

Becoming an Engineer in Public Universities: Pathways for Women and Minorities. Palgrave Studies in Urban Education

ERIC Educational Resources Information Center

Borman, Kathryn M., Ed.; Tyson, Will, Ed.; Halperin, Rhoda H., Ed.

2010-01-01

Based on research conducted in a three-year, mixed-method, multi-site National Science Foundation, Science, Technology, Engineering and Mathematics Talent Expansion Program (STEP) Project, this book offers a comprehensive look into how engineering department culture and climate impacts the successful retention of female and under-represented…

Measurement uncertainty for the Uniform Engine Testing Program conducted at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Abdelwahab, Mahmood; Biesiadny, Thomas J.; Silver, Dean

1987-01-01

An uncertainty analysis was conducted to determine the bias and precision errors and total uncertainty of measured turbojet engine performance parameters. The engine tests were conducted as part of the Uniform Engine Test Program which was sponsored by the Advisory Group for Aerospace Research and Development (AGARD). With the same engines, support hardware, and instrumentation, performance parameters were measured twice, once during tests conducted in test cell number 3 and again during tests conducted in test cell number 4 of the NASA Lewis Propulsion Systems Laboratory. The analysis covers 15 engine parameters, including engine inlet airflow, engine net thrust, and engine specific fuel consumption measured at high rotor speed of 8875 rpm. Measurements were taken at three flight conditions defined by the following engine inlet pressure, engine inlet total temperature, and engine ram ratio: (1) 82.7 kPa, 288 K, 1.0, (2) 82.7 kPa, 288 K, 1.3, and (3) 20.7 kPa, 288 K, 1.3. In terms of bias, precision, and uncertainty magnitudes, there were no differences between most measurements made in test cells number 3 and 4. The magnitude of the errors increased for both test cells as engine pressure level decreased. Also, the level of the bias error was two to three times larger than that of the precision error.

Highly porous scaffolds of PEDOT:PSS for bone tissue engineering.

PubMed

Guex, Anne Géraldine; Puetzer, Jennifer L; Armgarth, Astrid; Littmann, Elena; Stavrinidou, Eleni; Giannelis, Emmanuel P; Malliaras, George G; Stevens, Molly M

2017-10-15

Conjugated polymers have been increasingly considered for the design of conductive materials in the field of regenerative medicine. However, optimal scaffold properties addressing the complexity of the desired tissue still need to be developed. The focus of this study lies in the development and evaluation of a conductive scaffold for bone tissue engineering. In this study PEDOT:PSS scaffolds were designed and evaluated in vitro using MC3T3-E1 osteogenic precursor cells, and the cells were assessed for distinct differentiation stages and the expression of an osteogenic phenotype. Ice-templated PEDOT:PSS scaffolds presented high pore interconnectivity with a median pore diameter of 53.6±5.9µm and a total pore surface area of 7.72±1.7m 2 ·g -1 . The electrical conductivity, based on I-V curves, was measured to be 140µS·cm -1 with a reduced, but stable conductivity of 6.1µS·cm -1 after 28days in cell culture media. MC3T3-E1 gene expression levels of ALPL, COL1A1 and RUNX2 were significantly enhanced after 4weeks, in line with increased extracellular matrix mineralisation, and osteocalcin deposition. These results demonstrate that a porous material, based purely on PEDOT:PSS, is suitable as a scaffold for bone tissue engineering and thus represents a promising candidate for regenerative medicine. Tissue engineering approaches have been increasingly considered for the repair of non-union fractions, craniofacial reconstruction or large bone defect replacements. The design of complex biomaterials and successful engineering of 3-dimensional tissue constructs is of paramount importance to meet this clinical need. Conductive scaffolds, based on conjugated polymers, present interesting candidates to address the piezoelectric properties of bone tissue and to induce enhanced osteogenesis upon implantation. However, conductive scaffolds have not been investigated in vitro in great measure. To this end, we have developed a highly porous, electrically conductive scaffold based on PEDOT:PSS, and provide evidence that this purely synthetic material is a promising candidate for bone tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Study of unconventional aircraft engines designed for low energy consumption

NASA Technical Reports Server (NTRS)

Neitzel, R. E.; Hirschkron, R.; Johnston, R. P.

1976-01-01

A study of unconventional engine cycle concepts, which may offer significantly lower energy consumption than conventional subsonic transport turbofans, is described herein. A number of unconventional engine concepts were identified and parametrically studied to determine their relative fuel-saving potential. Based on results from these studies, regenerative, geared, and variable-boost turbofans, and combinations thereof, were selected along with advanced turboprop cycles for further evaluation and refinement. Preliminary aerodynamic and mechanical designs of these unconventional engine configurations were conducted and mission performance was compared to a conventional, direct-drive turofan reference engine. Consideration is given to the unconventional concepts, and their state of readiness for application. Areas of needed technology advancement are identified.

Kerosene-base fuels in small gasoline engines. Final report

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

Failla, C.C.; Pouring, A.A.

1991-01-01

This document presents the results of an engineering study to demonstrate the technology for converting small gasoline spark-ignited engines, to burn kerosene type fuels to power small generators (0.5 to 3.0 kw). Commercially available (plus those in the developmental stage), reciprocating, two-stroke, four stroke and rotary engines were evaluated for their conversion potential. Unique combustion systems were identified and trade-off studies conducted on engine type, combustion systems, and modification required to burn kerosene type fuels, with special emphasis given to minimizing life cycle cost. Recommendations for the most feasible system are given.

A sociocultural analysis of Latino high school students' funds of knowledge and implications for culturally responsive engineering education

NASA Astrophysics Data System (ADS)

Mejia, Joel Alejandro

Previous studies have suggested that, when funds of knowledge are incorporated into science and mathematics curricula, students are more engaged and often develop richer understandings of scientific concepts. While there has been a growing body of research addressing how teachers may integrate students' linguistic, social, and cultural practices with science and mathematics instruction, very little research has been conducted on how the same can be accomplished with Latino and Latina students in engineering. The purpose of this study was to address this gap in the literature by investigating how fourteen Latino and Latina high school adolescents used their funds of knowledge to address engineering design challenges. This project was intended to enhance the educational experience of underrepresented minorities whose social and cultural practices have been traditionally undervalued in schools. This ethnographic study investigated the funds of knowledge of fourteen Latino and Latina high school adolescents and how they used these funds of knowledge in engineering design. Participant observation, bi-monthly group discussion, retrospective and concurrent protocols, and monthly one-on-one interviews were conducted during the study. A constant comparative analysis suggested that Latino and Latina adolescents, although profoundly underrepresented in engineering, bring a wealth of knowledge and experiences that are relevant to engineering design thinking and practice.

Modified RS2101 rocket engine study program

NASA Technical Reports Server (NTRS)

1971-01-01

The purpose of the program is to perform design studies and analyses to determine the effects of incorporating a 60:1 expansion area ratio nozzle extension, extended firing time, and modified operating conditions and environments on the MM'71 rocket engine assembly. An injector-to-thrust chamber seal study was conducted to define potential solutions for leakage past this joint. The results and recommendations evolving from the engine thermal analyses, the injector-to-thrust chamber seal studies, and the nozzle extension joint stress analyses are presented.

A Study of Engineering Freshmen Regarding Nanotechnology Understanding

ERIC Educational Resources Information Center

Lu, Kathy

2009-01-01

This study was conducted under the grand scheme of nanotechnology education and was focused on examining the nanotechnology readiness of first-year engineering students. The study found that most students learned the term "nano" from popular science magazines or as a measurement unit; less than 5% of the students learned "nano" through…

SUPERFUND TREATABILITY CLEARINGHOUSE: EVALUATION OF AN ENGINEERED BIODEGRADATION SYSTEM AT THE NASHUA, N.H. SITE

EPA Science Inventory

The treatability study report presents the results of both laboratory and field studies conducted by Koppers on soils from the Nashua, N.H., NPL site. The purpose of these studies was to provide the necessary data to evaluate a ull-scale design for the Engineered Biodeg...

The Influence of Aspirations on Higher Education Choice: A Telecommunication Engineering Perspective

ERIC Educational Resources Information Center

Cubillo-Pinilla, Jose Maria; Sanchez-Herrera, Joaquin; Perez-Aguir, Waldo S.

2006-01-01

This paper analyses the influence of external factors that affect the decision-making process in the selection of telecommunications engineering studies. Particularly, we have studied the influence of factors related to the generation of expectations about the studies. A survey was conducted on a sample of 701 male and female telecommunications…

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.

The Effectiveness of Concept Maps in Teaching Physics Concepts Applied to Engineering Education: Experimental Comparison of the Amount of Learning Achieved with and without Concept Maps

ERIC Educational Resources Information Center

Martinez, Guadalupe; Perez, Angel Luis; Suero, Maria Isabel; Pardo, Pedro J.

2013-01-01

A study was conducted to quantify the effectiveness of concept maps in learning physics in engineering degrees. The following research question was posed: What was the difference in learning results from the use of concept maps to study a particular topic in an engineering course? The study design was quasi-experimental and used a post-test as a…

Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

NASA Technical Reports Server (NTRS)

Bansal, Indar

1993-01-01

The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

Thermal Conductivity Enhancement by Optical Phonon Sub-Band Engineering of Nanostructures Based on C and BN

DTIC Science & Technology

2005-09-01

Thermal Conductivity Enhancement by Optical Phonon Sub-Band Engineering of Nanostructures Based on C and BN DARPA CONTRACT MDA972-02-C-0044...AND SUBTITLE Thermal Conductivity Enhancement by Optical Phonon Sub-Band Engineering of Nanostructures Based on C and BN 5a. CONTRACT NUMBER 5b...Conductivity. Enhancement by Optical Phonon Sub-Bands Engineering in 3-D Nanostructures Based on C and BN Nanotubes" 1.3.1a. Phonon dynamics

Polypyrrole/Alginate Hybrid Hydrogels: Electrically Conductive and Soft Biomaterials for Human Mesenchymal Stem Cell Culture and Potential Neural Tissue Engineering Applications.

PubMed

Yang, Sumi; Jang, LindyK; Kim, Semin; Yang, Jongcheol; Yang, Kisuk; Cho, Seung-Woo; Lee, Jae Young

2016-11-01

Electrically conductive biomaterials that can efficiently deliver electrical signals to cells or improve electrical communication among cells have received considerable attention for potential tissue engineering applications. Conductive hydrogels are desirable particularly for neural applications, as they can provide electrical signals and soft microenvironments that can mimic native nerve tissues. In this study, conductive and soft polypyrrole/alginate (PPy/Alg) hydrogels are developed by chemically polymerizing PPy within ionically cross-linked alginate hydrogel networks. The synthesized hydrogels exhibit a Young's modulus of 20-200 kPa. Electrical conductance of the PPy/Alg hydrogels could be enhanced by more than one order of magnitude compared to that of pristine alginate hydrogels. In vitro studies with human bone marrow-derived mesenchymal stem cells (hMSCs) reveal that cell adhesion and growth are promoted on the PPy/Alg hydrogels. Additionally, the PPy/Alg hydrogels support and greatly enhance the expression of neural differentiation markers (i.e., Tuj1 and MAP2) of hMSCs compared to tissue culture plate controls. Subcutaneous implantation of the hydrogels for eight weeks induces mild inflammatory reactions. These soft and conductive hydrogels will serve as a useful platform to study the effects of electrical and mechanical signals on stem cells and/or neural cells and to develop multifunctional neural tissue engineering scaffolds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facile Synthesis of Conductive Polypyrrole Wrinkle Topographies on Polydimethylsiloxane via a Swelling-Deswelling Process and Their Potential Uses in Tissue Engineering.

PubMed

Aufan, M Rifqi; Sumi, Yang; Kim, Semin; Lee, Jae Young

2015-10-28

Electrically conducting biomaterials have gained great attention in various biomedical studies especially to influence cell and tissue responses. In addition, wrinkling can present a unique topography that can modulate cell-material interactions. In this study, we developed a simple method to create wrinkle topographies of conductive polypyrrole (wPPy) on soft polydimethylsiloxane surfaces via a swelling-deswelling process during and after PPy polymerization and by varying the thickness of the PPy top layers. As a result, various features of wPPy in the range of the nano- and microscales were successfully obtained. In vitro cell culture studies with NIH 3T3 fibroblasts and PC12 neuronal cells indicated that the conductive wrinkle topographies promote cell adhesion and neurite outgrowth of PC12 cells. Our studies help to elucidate the design of the surface coating and patterning of conducting polymers, which will enable us to simultaneously provide topographical and electrical signals to improve cell-surface interactions for potential tissue-engineering applications.

Advanced engine study program

NASA Technical Reports Server (NTRS)

Masters, A. I.; Galler, D. E.; Denman, T. F.; Shied, R. A.; Black, J. R.; Fierstein, A. R.; Clark, G. L.; Branstrom, B. R.

1993-01-01

A design and analysis study was conducted to provide advanced engine descriptions and parametric data for space transfer vehicles. The study was based on an advanced oxygen/hydrogen engine in the 7,500 to 50,000 lbf thrust range. Emphasis was placed on defining requirements for high-performance engines capable of achieving reliable and versatile operation in a space environment. Four variations on the expander cycle were compared, and the advantages and disadvantages of each were assessed. Parametric weight, envelope, and performance data were generated over a range of 7,500 to 50,000 lb thrust and a wide range of chamber pressure and nozzle expansion ratio.

Space shuttle hypergolic bipropellant RCS engine design study, Bell model 8701

NASA Technical Reports Server (NTRS)

1974-01-01

A research program was conducted to define the level of the current technology base for reaction control system rocket engines suitable for space shuttle applications. The project consisted of engine analyses, design, fabrication, and tests. The specific objectives are: (1) extrapolating current engine design experience to design of an RCS engine with required safety, reliability, performance, and operational capability, (2) demonstration of multiple reuse capability, and (3) identification of current design and technology deficiencies and critical areas for future effort.

Physiology and the Biomedical Engineering Curriculum: Utilizing Emerging Instructional Technologies to Promote Development of Adaptive Expertise in Undergraduate Students

ERIC Educational Resources Information Center

Nelson, Regina K.

2013-01-01

A mixed-methods research study was designed to test whether undergraduate engineering students were better prepared to learn advanced topics in biomedical engineering if they learned physiology via a quantitative, concept-based approach rather than a qualitative, system-based approach. Experiments were conducted with undergraduate engineering…

An Evaluation of Streaming Digital Video Resources in On- and Off-Campus Engineering Management Education

ERIC Educational Resources Information Center

Palmer, Stuart

2007-01-01

A recent television documentary on the Columbia space shuttle disaster was converted to streaming digital video format for educational use by on- and off-campus students in an engineering management study unit examining issues in professional engineering ethics. An evaluation was conducted to assess the effectiveness of this new resource. Use of…

Feasibility study of a pressure-fed engine for a water recoverable space shuttle booster. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

An overview is presented of the results of the analyses conducted in support of the selected engine system for the pressure-fed booster stage. During initial phases of the project, a gimbaled, regeneratively cooled, fixed thrust engine having a coaxial pintle injector was selected as optimum for this configuration.

Spacecraft systems engineering: An introduction to the process at GSFC

NASA Technical Reports Server (NTRS)

Fragomeni, Tony; Ryschkewitsch, Michael G.

1993-01-01

The main objective in systems engineering is to devise a coherent total system design capable of achieving the stated requirements. Requirements should be rigid. However, they should be continuously challenged, rechallenged and/or validated. The systems engineer must specify every requirement in order to design, document, implement and conduct the mission. Each and every requirement must be logically considered, traceable and evaluated through various analysis and trade studies in a total systems design. Margins must be determined to be realistic as well as adequate. The systems engineer must also continuously close the loop and verify system performance against the requirements. The fundamental role of the systems engineer, however, is to engineer, not manage. Yet, in large, complex missions, where more than one systems engineer is required, someone needs to manage the systems engineers, and we call them 'systems managers.' Systems engineering management is an overview function which plans, guides, monitors and controls the technical execution of a project as implemented by the systems engineers. As the project moves on through Phases A and B into Phase C/D, the systems engineering tasks become a small portion of the total effort. The systems management role increases since discipline subsystem engineers are conducting analyses and reviewing test data for final review and acceptance by the systems managers.

NASA Researcher Adjusts a Travelling Magnetic Wave Plasma Engine

NASA Image and Video Library

1964-02-21

Raymond Palmer, of the Electromagnetic Propulsion Division’s Plasma Flow Section, adjusts the traveling magnetic wave plasma engine being operated in the Electric Power Conversion at the National Aeronautics and Space Administration (NASA) Lewis Research Center. During the 1960s Lewis researchers were exploring several different methods of creating electric propulsion systems, including the traveling magnetic wave plasma engine. The device operated similarly to alternating-current motors, except that a gas, not a solid, was used to conduct the electricity. A magnetic wave induced a current as it passed through the plasma. The current and magnetic field pushed the plasma in one direction. Palmer and colleague Robert Jones explored a variety of engine configurations in the Electric Propulsion Research Building. The engine is seen here mounted externally on the facility’s 5-foot diameter and 16-foot long vacuum tank. The four magnetic coils are seen on the left end of the engine. The researchers conducted two-minute test runs with varying configurations and used of both argon and xenon as the propellant. The Electric Propulsion Research Building was built in 1942 as the Engine Propeller Research Building, often called the Prop House. It contained four test cells to study large reciprocating engines with their propellers. After World War II, the facility was modified to study turbojet engines. By the 1960s, the facility was modified again for electric propulsion research and given its current name.

Soft Skills in Pedagogical Practices with Different Curriculum for Engineering Education

NASA Astrophysics Data System (ADS)

Mohamad, M. M.; Yee, M. H.; Tee, T. K.; Mukhtar, M. Ibrahim; Ahmad, A.

2017-08-01

The rapid growth of the economy in Malaysia is a benchmark for the country’s progress. The demand for skilled worker has started to increase from year to year resulted in the implementation of reforms and necessary skills will be applied to each of the graduates who will step into the nature of work. Therefore, a study was conducted to identify the level of soft skills among students in higher education institutions. The study was conducted at the Universiti Tun Hussein Onn Malaysia (UTHM) and involved 302 samples of final year students from Faculty of Civil Engineering, Faculty of Mechanical Engineering and the Faculty of Electrical Engineering. There are several types of soft skills have been viewed on the students such as creative thinking skills, teamwork skills, communication skills, decision-making skills, interpersonal skills and leadership skills. The analysis results show that all of the soft skills are on the high level. Furthermore, the results of ANOVA showed a significant difference in soft skills mastery among Civil Engineering students and Mechanical Engineering students. As a conclusion, the overall level of soft skills mastery among Faculty of Civil Engineering, Faculty of Mechanical Engineering and the Faculty of Electrical Engineering students is on the high level. The soft skills elements are very important in order to produce skills workers that suitable with the industry.

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.

Investigation into the impact of privatizing civil engineering operations in Louisiana DOTD.

DOT National Transportation Integrated Search

2013-06-01

The purpose of this study is to investigate the impact of privatizing all civil engineering operations in : the Louisiana Department of Transportation and Development (DOTD). It was investigated by : conducting a national and international literature...

Inlet Flow Valve Engine Analyses

NASA Technical Reports Server (NTRS)

Champagne, G. A.

2004-01-01

Pratt&Whitney, under Task Order 13 of the NASA Large Engine Technology (LET) Contract, conducted a study to determine the operating characteristics, performance and weights of Inlet Flow Valve (IFV) propulsion concepts for a Mach 2.4 High Speed Civil Transport (HSCT).

External fuel vaporization study, phase 1

NASA Technical Reports Server (NTRS)

Szetela, E. J.; Chiappetta, L.

1980-01-01

A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

A Survey of Aircraft Ground Support Equipment Utilization and Oil Condition at the Mandatory Six Month Inspection

DTIC Science & Technology

2016-09-30

In parallel with the oil change interval study an engineering evaluation of a handheld oil condition analyzer was conducted. Within the limitations...of the study of diesel engine powered AGE assets at two U.S. Air Force locations, assets monitored were not impacted by eliminating the 6-month oil...limitations of the study , conclusions can be made from the cumulative knowledge of analyzing crankcase lubricants of diesel engine powered AGE assets

Propulsion technology for an advanced subsonic transport

NASA Technical Reports Server (NTRS)

Beheim, M. A.; Antl, R. J.; Povolny, J. H.

1972-01-01

Engine design studies for future subsonic commercial transport aircraft were conducted in parallel with airframe studies. These studies surveyed a broad distribution of design variables, including aircraft configuration, payload, range, and speed, with particular emphasis on reducing noise and exhaust emissions without severe economic and performance penalties. The results indicated that an engine for an advanced transport would be similar to the currently emerging turbofan engines. Application of current technology in the areas of noise suppression and combustors imposed severe performance and economic penalties.

Do Our Engineering Students Spend Enough Time Studying?

ERIC Educational Resources Information Center

Kolari, S.; Savander-Ranne, C.; Viskari, E.-L.

2006-01-01

In higher education one of the most important learning goals is deep understanding. Achieving this goal needs time and effort. The authors discuss their observations of student time use on the basis of several case studies which they have conducted in the field of engineering education in Finland. The time that the students spend studying is…

Ultra-efficient Engine Diameter Study

NASA Technical Reports Server (NTRS)

Daggett, David L.; Brown, Stephen T.; Kawai, Ron T.

2003-01-01

Engine fan diameter and Bypass Ratio (BPR) optimization studies have been conducted since the beginning of the turbofan age with the recognition that reducing the engine core jet velocity and increasing fan mass flow rate generally increases propulsive efficiency. However, performance tradeoffs limit the amount of fan flow achievable without reducing airplane efficiency. This study identifies the optimum engine fan diameter and BPR, given the advanced Ultra-Efficient Engine Technology (UEET) powerplant efficiencies, for use on an advanced subsonic airframe. Engine diameter studies have historically focused on specific engine size options, and were limited by existing technology and transportation infrastructure (e.g., ability to fit bare engines through aircraft doors and into cargo holds). This study is unique in defining the optimum fan diameter and drivers for future 2015 (UEET) powerplants while not limiting engine fan diameter by external constraints. This report follows on to a study identifying the system integration issues of UEET engines. This Engine Diameter study was managed by Boeing Phantom Works, Seattle, Washington through the NASA Glenn Revolutionary Aero Space Engine Research (RASER) contract under task order 10. Boeing Phantom Works, Huntington Beach, completed the engine/airplane sizing optimization, while the Boeing Commercial Airplane group (BCA) provided design oversight. A separate subcontract to support the overall project was issued to Tuskegee University.

Variable speed gas engine-driven air compressor system

NASA Astrophysics Data System (ADS)

Morgan, J. R.; Ruggles, A. E.; Chen, T. N.; Gehret, J.

1992-11-01

Tecogen Inc. and Ingersoll-Rand Co. as a subcontractor have designed a nominal 150-hp gas engine-driven air compressor utilizing the TECODRIVE 8000 engine and the Ingersoll-Rand 178.5-mm twin screw compressor. Phase 1 included the system engineering and design, economic and applications studies, and a draft commercialization plan. Phase 2 included controls development, laboratory prototype construction, and performance testing. The testing conducted verified that the compressor meets all design specifications.

Flow Matching Results of an MHD Energy Bypass System on a Supersonic Turbojet Engine Using the Numerical Propulsion System Simulation (NPSS) Environment

NASA Technical Reports Server (NTRS)

Benyo, Theresa L.

2011-01-01

Flow matching has been successfully achieved for an MHD energy bypass system on a supersonic turbojet engine. The Numerical Propulsion System Simulation (NPSS) environment helped perform a thermodynamic cycle analysis to properly match the flows from an inlet employing a MHD energy bypass system (consisting of an MHD generator and MHD accelerator) on a supersonic turbojet engine. Working with various operating conditions (such as the applied magnetic field, MHD generator length and flow conductivity), interfacing studies were conducted between the MHD generator, the turbojet engine, and the MHD accelerator. This paper briefly describes the NPSS environment used in this analysis. This paper further describes the analysis of a supersonic turbojet engine with an MHD generator/accelerator energy bypass system. Results from this study have shown that using MHD energy bypass in the flow path of a supersonic turbojet engine increases the useful Mach number operating range from 0 to 3.0 Mach (not using MHD) to a range of 0 to 7.0 Mach with specific net thrust range of 740 N-s/kg (at ambient Mach = 3.25) to 70 N-s/kg (at ambient Mach = 7). These results were achieved with an applied magnetic field of 2.5 Tesla and conductivity levels in a range from 2 mhos/m (ambient Mach = 7) to 5.5 mhos/m (ambient Mach = 3.5) for an MHD generator length of 3 m.

Advanced controls for airbreathing engines, volume 3: Allison gas turbine

NASA Technical Reports Server (NTRS)

Bough, R. M.

1993-01-01

The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for airbreathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two-phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 3 of these reports describes the studies performed by the Allison Gas Turbine Division.

Advanced control for airbreathing engines, volume 1: Pratt and Whitney

NASA Technical Reports Server (NTRS)

Ralph, J. A.

1993-01-01

The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 1 of these reports describes the studies performed by Pratt & Whitney.

Geotechnical engineering in US elementary schools

NASA Astrophysics Data System (ADS)

Suescun-Florez, Eduardo; Iskander, Magued; Kapila, Vikram; Cain, Ryan

2013-06-01

This paper reports on the results of several geotechnical engineering-related science activities conducted with elementary-school students. Activities presented include soil permeability, contact stress, soil stratigraphy, shallow and deep foundations, and erosion in rivers. The permeability activity employed the LEGO NXT platform for data acquisition, the soil profile and foundations activity employed natural and transparent soils as well as LEGO-based foundation models, and the erosion activity utilised a 3D printer to assist with construction of building models. The activities seek to enhance students' academic achievement, excite them about geotechnical engineering, and motivate them to study science and math. Pre- and post-activity evaluations were conducted to assess both the suitability of the activities and the students' learning. Initial results show that students gain a reasonable understanding of engineering principles. Moreover, the geotechnical engineering activities provided students an opportunity to apply their math skills and science knowledge.

Lean Stability augmentation study

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

Proceedings of the Thirteenth Annual Software Engineering Workshop

NASA Technical Reports Server (NTRS)

1988-01-01

Topics covered in the workshop included studies and experiments conducted in the Software Engineering Laboratory (SEL), a cooperative effort of NASA Goddard Space Flight Center, the University of Maryland, and Computer Sciences Corporation; software models; software products; and software tools.

Follow-On Technology Requirement Study for Advanced Subsonic Transport

NASA Technical Reports Server (NTRS)

Wendus, Bruce E.; Stark, Donald F.; Holler, Richard P.; Funkhouser, Merle E.

2003-01-01

A study was conducted to define and assess the critical or enabling technologies required for a year 2005 entry into service (EIS) engine for subsonic commercial aircraft, with NASA Advanced Subsonic Transport goals used as benchmarks. The year 2005 EIS advanced technology engine is an Advanced Ducted Propulsor (ADP) engine. Performance analysis showed that the ADP design offered many advantages compared to a baseline turbofan engine. An airplane/ engine simulation study using a long range quad aircraft quantified the effects of the ADP engine on the economics of typical airline operation. Results of the economic analysis show the ADP propulsion system provides a 6% reduction in direct operating cost plus interest, with half the reduction resulting from reduced fuel consumption. Critical and enabling technologies for the year 2005 EIS ADP were identified and prioritized.

Pathways to an Engineering Career

ERIC Educational Resources Information Center

Pearson, Willie, Jr.; Miller, Jon D.

2012-01-01

Utilizing data from the 20-year record of the Longitudinal Study of American Youth (LSAY), this analysis uses a set of variables to predict employment in engineering for a national sample of adults aged 34 to 37. The LSAY is one of the longest longitudinal studies of the impact of secondary education and postsecondary education conducted in the…

Perceptions and Practices of Data Sharing in Engineering Education

ERIC Educational Resources Information Center

Johri, Aditya; Yang, Seungwon; Vorvoreanu, Mihaela; Madhavan, Krishna

2016-01-01

As part of our NSF funded collaborative project on Data Sharing within Engineering Education Community, we conducted an empirical study to better understand the current climate of data sharing and participants' future expectations of the field. We present findings of this mixed method study and discuss implications. Overall, we found strong…

Skills Conversion Project: Chapter 16, Public Services. Final Report.

ERIC Educational Resources Information Center

National Society of Professional Engineers, Washington, DC.

From November 1971 to February 1972 the National Society of Professional Engineers conducted a study for the U.S. Department of Labor of public services of Orange County, California, to identify employment potential for scientific personnel in aerospace and defense engineering. The study findings were that fewer than 50 new jobs will become…

Engineering Education and Practice in the United States: Foundations of Our Techno-Economic Future.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC.

The National Research Council's Committee on the Education and Utilization of the Engineer conducted a study aimed at achieving a comprehensive understanding of engineering in the United States and an assessment of its capacity to meet present and future needs. This document reports on the findings of the committee's work over a 2-year period. The…

Labor Markets for New Science and Engineering Graduates in Private Industry. Science Resources Studies Highlights.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC. Div. of Science Resources Studies.

Data are presented on labor market conditions for science and engineering graduates based on responses of 255 firms to mail and telephone surveys conducted in late fall of 1981. Highlights presented in table, chart, and text indicate: (1) definite and likely shortages were concentrated in the computer and engineering fields; (2) chemical,…

CFD analysis of turboprop engine oil cooler duct for best rate of climb condition

NASA Astrophysics Data System (ADS)

Kalia, Saurabh; CA, Vinay; Hegde, Suresh M.

2016-09-01

Turboprop engines are widely used in commuter category airplanes. Aircraft Design bureaus routinely conduct the flight tests to confirm the performance of the system. The lubrication system of the engine is designed to provide a constant supply of clean lubrication oil to the engine bearings, the reduction gears, the torque-meter, the propeller and the accessory gearbox. The oil lubricates, cools and also conducts foreign material to the oil filter where it is removed from further circulation. Thus a means of cooling the engine oil must be provided and a suitable oil cooler (OC) and ducting system was selected and designed for this purpose. In this context, it is relevant to study and analyse behaviour of the engine oil cooler system before commencing actual flight tests. In this paper, the performance of the oil cooler duct with twin flush NACA inlet housed inside the nacelle has been studied for aircraft best rate of climb (ROC) condition using RANS based SST K-omega model by commercial software ANSYS Fluent 13.0. From the CFD analysis results, it is found that the mass flow rate captured and pressure drop across the oil cooler for the best ROC condition is meeting the oil cooler manufacturer requirements thus, the engine oil temperature is maintained within prescribed limits.

Energy Efficient Engine combustor test hardware detailed design report

NASA Technical Reports Server (NTRS)

Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

1984-01-01

The Energy Efficient Engine (E3) Combustor Development effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent was to evolve a design which meets the stringent emissions and life goals of the E3 as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this development effort will be incorporated into the engine combustion system hardware design. This advanced engine combustion system will then be evaluated in component testing to verify the design intent. What is evolving from this development effort is an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3. Fuel nozzle, diffuser, starting, and emissions design studies are discussed.

Screening studies of advanced control concepts for airbreathing engines

NASA Technical Reports Server (NTRS)

Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

1993-01-01

The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target aircraft/engine combinations were considered: a military high performance fighter mission, a high speed civil transport mission, and a civil tiltrotor mission. Each of the advanced control concepts considered in the study were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

First-year engineering students' views of the nature of engineering: implications for engineering programmes

NASA Astrophysics Data System (ADS)

Karataş, F. Ö.; Bodner, G. M.; Unal, Suat

2016-01-01

A study was conducted on the views of the nature of engineering held by 114 first-year engineering majors; the study built on prior work on views of the nature of science held by students, their instructors, and the general public. Open-coding analysis of responses to a 12-item questionnaire suggested that the participants held tacit beliefs that engineering (1) involves problem solving; (2) is a form of applied science; (3) involves the design of artefacts or systems; (4) is subject to various constraints; and (5) requires teamwork. These beliefs, however, were often unsophisticated, and significant aspects of the field of engineering as described in the literature on engineering practices were missing from the student responses. The results of this study are important because students' beliefs have a strong influence on what they value in a classroom situation, what they attend to in class, and how they choose to study for a course.

Advanced Technology Spark-Ignition Aircraft Piston Engine Design Study

NASA Technical Reports Server (NTRS)

Stuckas, K. J.

1980-01-01

The advanced technology, spark ignition, aircraft piston engine design study was conducted to determine the improvements that could be made by taking advantage of technology that could reasonably be expected to be made available for an engine intended for production by January 1, 1990. Two engines were proposed to account for levels of technology considered to be moderate risk and high risk. The moderate risk technology engine is a homogeneous charge engine operating on avgas and offers a 40% improvement in transportation efficiency over present designs. The high risk technology engine, with a stratified charge combustion system using kerosene-based jet fuel, projects a 65% improvement in transportation efficiency. Technology enablement program plans are proposed herein to set a timetable for the successful integration of each item of required advanced technology into the engine design.

Possibility of reducing CO2 emissions from internal combustion engines

NASA Astrophysics Data System (ADS)

Drabik, Dawid; Mamala, Jarosław; Śmieja, Michał; Prażnowski, Krzysztof

2017-10-01

Article defines on the possibility of reduction CO2 of the internal combustion engine and presents the analysis based on originally conducted studies. The increase in overall engine efficiency is sought after by all engineers dealing with engine construction, one of the major ways to reduce CO2 emissions is to increase the compression ratio. The application of the compression ratio that has been increased constructional in the engine will, on one hand, bring about the increase in the theoretical efficiency, but, on the other hand, require a system for pressure control at a higher engine load in order to prevent engine knocking. For the purposes of the article there was carried out a number of studies and compiled results, and on their basis determined what have a major impact on the reducing CO2.

Status of an inlet configuration trade study for the Douglas HSCT

NASA Technical Reports Server (NTRS)

Jones, Jay R.; Welge, H. Robert

1992-01-01

An inlet concept integration trade study for an HSCT is being conducted under contract to NASA LeRC. The HSCT mission has a supersonic cruise Mach number of 2.4 and a subsonic cruise Mach number of 0.95. The engine selected for this study is the GE VCE (variable cycle engine) with FLADE (fan on blade). Six inlet configurations will be defined. Inlet configurations will be axisymmetric and rectangular mixed-compression inlets in single-engine nacelles. Airplane performance for each inlet configuration will be estimated and then compared. The most appropriate inlet configuration for this airplane/engine combination will be determined by Sep. 1991.

40 CFR 94.905 - Testing exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.905... prohibitions of this part new engines that are being used solely for the purpose of conducting a test program... purpose would be research, investigations, studies, demonstrations, technology development, or training...

40 CFR 94.905 - Testing exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.905... prohibitions of this part new engines that are being used solely for the purpose of conducting a test program... purpose would be research, investigations, studies, demonstrations, technology development, or training...

40 CFR 94.905 - Testing exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.905... prohibitions of this part new engines that are being used solely for the purpose of conducting a test program... purpose would be research, investigations, studies, demonstrations, technology development, or training...

40 CFR 94.905 - Testing exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.905... prohibitions of this part new engines that are being used solely for the purpose of conducting a test program... purpose would be research, investigations, studies, demonstrations, technology development, or training...

40 CFR 94.905 - Testing exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Exclusion and Exemption Provisions § 94.905... prohibitions of this part new engines that are being used solely for the purpose of conducting a test program... purpose would be research, investigations, studies, demonstrations, technology development, or training...

Investigation into the impact of privatizing civil engineering operations in Louisiana DOTD : [technical summary].

DOT National Transportation Integrated Search

2013-06-01

This report documents an investigation into the possibility of privatizing the civil engineering operations in the Louisiana Department : of Transportation and Development (DOTD). The study was conducted in response to House Resolution 105 of the Lou...

Use of traffic displays for general aviation approach spacing : a human factors study

DOT National Transportation Integrated Search

2007-12-01

A flight experiment was conducted to assess human factors issues associated with pilot use of traffic displays for approach : spacing. Sixteen multi-engine rated pilots participated. Eight flew approaches in a twin-engine Piper Aztec originating in :...

A systematic literature review of engineering identity: definitions, factors, and interventions affecting development, and means of measurement

NASA Astrophysics Data System (ADS)

Morelock, John R.

2017-11-01

Studies exploring what it means to be an engineer professionally have been conducted for decades, but have boomed in recent years. This systematic literature review aims to organise extant studies on engineering identity by coding around four key variables: (a) definitions of engineering identity, (b) factors affecting engineering identity development, (c) interventions affecting engineering identity development, and (d) means of measuring identity. In doing so, this review provides strategies for future research and educational interventions to advance work related to engineering identity. Publications were selected for inclusion by screening and appraising results obtained from databases and keywords refined through a scoping study. Derived from key findings, suggestions for future research include bridging disparate strands of engineering identity literature and incorporating more varied methodological approaches. Also from key findings, suggestions for future practice involve better connecting existing definitions of engineering identity and factors known to affect identity development with identity-related interventions.

Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Advanced expander cycle engine optimization

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1979-01-01

The performance optimization of expander cycle engines at vacuum thrust levels of 10K, 15K, and 20K lb is discussed. The optimization is conducted for a maximum engine length with an extendible nozzle in the retracted position of 60 inches and an engine mixture ratio of 6.0:1. The thrust chamber geometry and cycle analyses are documented. In addition, the sensitivity of a recommended baseline expander cycle to component performance variations is determined and chilldown/start propellant consumptions are estimated.

Altitude Investigation of Performance of Turbine-propeller Engine and Its Components

NASA Technical Reports Server (NTRS)

Wallner, Lewis E; Saari, Martin J

1950-01-01

An investigation was conducted on a turbine-propeller engine in the NACA Lewis altitude wind tunnel at altitudes from 5000 to 35,000 feet. The applicability of generalized parameters to turbine-propeller engine data, analyses of the compressor, the combustion chambers, and the turbine, and a study of the over-all engine performance are reported. Engine performance data obtained at sea-level static conditions could be used to predict static performance at altitudes up to 35,000 feet by use of the standard generalized parameters.

A study to estimate and compare the total particulate matter emission indices (EIN) between traditional jet fuel and two blends of Jet A/Camelina biofuel used in a high by-pass turbofan engine: A case study of Honeywell TFE-109 engine

NASA Astrophysics Data System (ADS)

Shila, Jacob Joshua Howard

The aviation industry is expected to grow at an annual rate of 5% until the year 2031 according to Boeing Outlook Report of 2012. Although the aerospace manufacturers have introduced new aircraft and engines technologies to reduce the emissions generated by aircraft engines, about 15% of all aircraft in 2032 will be using the older technologies. Therefore, agencies such as the National Aeronautics and Astronautics Administration (NASA), Federal Aviation Administration (FAA), the Environmental Protection Agency (EPA) among others together with some academic institutions have been working to characterize both physical and chemical characteristics of the aircraft particulate matter emissions to further understand their effects to the environment. The International Civil Aviation Organization (ICAO) is also working to establish an inventory with Particulate Matter emissions for all the aircraft turbine engines for certification purposes. This steps comes as a result of smoke measurements not being sufficient to provide detailed information on the effects of Particulate Matter (PM) emissions as far as the health and environmental concerns. The use of alternative fuels is essential to reduce the impacts of emissions released by Jet engines since alternative aviation fuels have been studied to lower particulate matter emissions in some types of engines families. The purpose of this study was to determine whether the emission indices of the biofuel blended fuels were lower than the emission indices of the traditional jet fuel at selected engine thrust settings. The biofuel blends observed were 75% Jet A-25% Camelina blend biofuel, and 50% Jet A-50% Jet A blend biofuel. The traditional jet fuel in this study was the Jet A fuel. The results of this study may be useful in establishing a baseline for aircraft engines' PM inventory. Currently the International Civil Aviation Organization (ICAO) engines emissions database contains only gaseous emissions data for only the TFE 731 and JT15D engines' families as representatives of other engines with rated thrust of 6000 pounds or below. The results of this study may be used to add to the knowledge of PM emission data that has been collected in other research studies. This study was quantitative in nature. Three factors were designated which were the types of fuels studied. The TFE-109 turbofan engine was the experimental subject. The independent variable was the engine thrust setting while the response variable was the emission index. Four engine runs were conducted for each fuel. In each engine run, four engine thrust settings were observed. The four engine thrust levels were 10%, 30%, 85%, and 100% rated thrusts levels. Therefore, for each engine thrust settings, there four replicates. The experiments were conducted using a TFE-109 engine test cell located in the Niswonger Aviation Technology building at the Purdue University Airport. The testing facility has the capability to conduct the aircraft PM emissions tests. Due to the equipment limitations, the study was limited to observe total PM emissions instead of specifically measuring the non-volatile PM emissions. The results indicate that the emissions indices of the blended biofuels were not statistically significantly lower compared to the emissions of the traditional jet fuel at rated thrust levels of 100% and 85% of TFE-109 turbofan engine. However, the emission indices for the 50%Jet A - 50%Camelina biofuel blend were statistically significantly lower compared to the emission indices of the 100% Jet A fuel at 10% and 30% engine rated thrusts levels of TFE-109 engine. The emission indices of the 50%-50% biofuel blend were lower by reductions of 15% and 17% at engine rated thrusts of 10% and 30% respectively compared to the emissions indices of the traditional jet fuel at the same engine thrust levels. Experimental modifications in future studies may provide estimates of the emissions indices range for this particular engine these estimates may be used to estimate the levels of PM emissions for other similar engines. Additional measurements steps such as heating of the sampling line, sampling dilution application, sampling line loss estimates, and calculations of the sampling line PM residence times will also be useful future results.

Concepts and Contexts in Engineering and Technology Education: An International and Interdisciplinary Delphi Study

ERIC Educational Resources Information Center

Rossouw, Ammeret; Hacker, Michael; de Vries, Marc J.

2011-01-01

Inspired by a similar study by Osborne et al. we have conducted a Delphi study among experts to identify key concepts to be taught in engineering and technology education and relevant and meaningful contexts through which these concepts can be taught and learnt. By submitting the outcomes of the Delphi study to a panel of experts in a two-day…

Effect of compression ratio, nozzle opening pressure, engine load, and butanol addition on nanoparticle emissions from a non-road diesel engine.

PubMed

Maurya, Rakesh Kumar; Saxena, Mohit Raj; Rai, Piyush; Bhardwaj, Aashish

2018-05-01

Currently, diesel engines are more preferred over gasoline engines due to their higher torque output and fuel economy. However, diesel engines confront major challenge of meeting the future stringent emission norms (especially soot particle emissions) while maintaining the same fuel economy. In this study, nanosize range soot particle emission characteristics of a stationary (non-road) diesel engine have been experimentally investigated. Experiments are conducted at a constant speed of 1500 rpm for three compression ratios and nozzle opening pressures at different engine loads. In-cylinder pressure history for 2000 consecutive engine cycles is recorded and averaged data is used for analysis of combustion characteristics. An electrical mobility-based fast particle sizer is used for analyzing particle size and mass distributions of engine exhaust particles at different test conditions. Soot particle distribution from 5 to 1000 nm was recorded. Results show that total particle concentration decreases with an increase in engine operating loads. Moreover, the addition of butanol in the diesel fuel leads to the reduction in soot particle concentration. Regression analysis was also conducted to derive a correlation between combustion parameters and particle number emissions for different compression ratios. Regression analysis shows a strong correlation between cylinder pressure-based combustion parameters and particle number emission.

Influence of internship toward entrepreneurship interest for mechanical engineering students

NASA Astrophysics Data System (ADS)

Sunyoto, Nugroho, Agus; Ulum, Miftakhul

2017-03-01

This study was aimed to determine the influence of internship toward students' entrepreneurship interest. Mechanical Engineering Education students from 2013 Batch who had the internship from Engineering Faculty at Semarang State University are the subject of this study. Data was collected through questionnaire and analyzed by simple regression analysis method. The internship subject score and entrepreneurship are categorized in very good level in which the average is 87.08% and 85.61%. However, the influence of internship toward students' interest is categorized in low level in which the average score is 7.9%. Internship section shall encourage students to study entrepreneurship aspects during the internship for entrepreneurship interest improvement and the students' preparation once they graduated. Description scoring standard is needed for scoring the students although they conduct their internship at different locations and companies. The students are highly recommended to conduct an an internship at entrepreneurship-based companies.

Fundamental Study of Antimonide Nanostructures by Molecular Beam Epitaxy

DTIC Science & Technology

2016-02-04

Faculty of Engineering, Chulalongkorn University, Phayathai Road, Bangkok 10330, Thailand Tel. (+66) 2218-6524, Fax. (+66) 2218-6523 E-mail...Engineering Department Faculty of Engineering Chulalongkorn University, Phayathai Road, Bangkok 10330, Thailand Tel. 662-218-6524, Fax. 662-218-6523...September 2014 to July 2015 being conducted at Chulalongkorn University in Thailand . Following the research work on InAs quantum dots (QDs) and quantum

Language Needs Analysis of Iranian Undergraduate Students of Computer Engineering: A Study of Reading Skill

ERIC Educational Resources Information Center

Fard-Kashani, Alireza; Jahromi, Abdol Hossein Zahedi; Javadi, Ali; Fallahi, Ali Mohammad

2015-01-01

The current study aimed at diagnosing the language needs of Iranian undergraduate students of computer engineering in order to find out whether there is any significant difference in perceptions between the students and their ESAP (English for Specific Academic Purpose) teachers, concerning their Reading skill needs. To conduct the intended…

Elementary Students' Learning of Materials Science Practices through Instruction Based on Engineering Design Tasks

ERIC Educational Resources Information Center

Wendell, Kristen Bethke; Lee, Hee-Sun

2010-01-01

Materials science, which entails the practices of selecting, testing, and characterizing materials, is an important discipline within the study of matter. This paper examines how third grade students' materials science performance changes over the course of instruction based on an engineering design challenge. We conducted a case study of nine…

What Value Does Service Learning Have on Introductory Engineering Students' Motivation and ABET Program Outcomes?

ERIC Educational Resources Information Center

Sevier, Carol; Chyung, Seung Youn; Callahan, Janet; Schrader, Cheryl B.

2012-01-01

A quasi-experimental study was conducted to investigate the effectiveness of using a service learning (SL) method on influencing introductory engineering students' motivation and ABET program outcomes, compared to the effectiveness of using a conventional, non-service-learning (NSL) method. The sample used in the study was 214 students enrolled in…

Graduate Research in Technology and Engineering Education: 2000-2009

ERIC Educational Resources Information Center

Foster, W. Tad

2010-01-01

The purpose of this study was to amass as comprehensive a collection of dissertations and theses in technology and engineering education as possible, and to conduct a modified meta-analysis of this body of research. The current study was limited to dissertations and theses completed between 2000 and 2009 that were identified using the ProQuest…

Action Learning in Undergraduate Engineering Thesis Supervision

ERIC Educational Resources Information Center

Stappenbelt, Brad

2017-01-01

In the present action learning implementation, twelve action learning sets were conducted over eight years. The action learning sets consisted of students involved in undergraduate engineering research thesis work. The concurrent study accompanying this initiative investigated the influence of the action learning environment on student approaches…

Tripropellant engine study

NASA Technical Reports Server (NTRS)

Wheeler, D. B.

1977-01-01

Work conducted was devoted to three main tasks. Thermochemical equilibrium performance data were assembled to establish the expected performance calculations of the mode 1 engine propellant combinations and thermodynamic and transport data for the products of combustion. Turbine drive gas characteristics were also established. Thrust chamber and nozzle cooling studies were devoted to the evaluation of H2, C3H8, CH4, and RP-1 as coolants in the existing SSME cooling circuit geometry. It was found that all these candidate coolants are feasible without limiting the desired operating conditions with the exception of RP-1, which would limit the maximum P(c) to 2000 psia. RP-1 could be used, however, to cool the nozzle only without imposing the chamber pressure limit. A total of 15 candidate engine system cycles were selected and a preliminary engine system balance was conducted for 12 of these systems to establish component operating flowrates, pressures and temperatures. It was found that the staged combustion cycles employing fuel rich LOX/hydrocarbon turbine drive gases are power limited.

Thermal Conductivity Enhancement by Optical Phonon Sub-Band Engineering of Nanostructures Based on C and BN

DTIC Science & Technology

2002-01-01

Thermal Conductivity Enhancement by Optical Phono n Sub-Band Engineering of Nanostructures Based on C and BN DARPA CONTRACT MDA972-02-C-0044... Engineering in 3-D Nanostructures Based on C an d BN Nanotubes " 1.3.1a. Phonon dynamics and thermal properties of zigzag carbon nanotubes Content I...Conductivity. Enhancement by Optical Phonon Sub-Bands Engineering in 3-D Nanostructure s Based on C and BN Nanotubes " . Here, the dynamics of the heat

Far Noise Field of Air Jets and Jet Engines

NASA Technical Reports Server (NTRS)

Callaghan, Edmund E; Coles, Willard D

1957-01-01

An experimental investigation was conducted to study and compare the acoustic radiation of air jets and jet engines. A number of different nozzle-exit shapes were studied with air jets to determine the effect of exit shape on noise generation. Circular, square, rectangular, and elliptical convergent nozzles and convergent-divergent and plug nozzles were investigated. The spectral distributions of the sound power for the engine and the air jet were in good agreement for the case where the engine data were not greatly affected by reflection or jet interference effects. Such power spectra for a subsonic or slightly choked engine or air jet show that the peaks of the spectra occur at a Strouhal number of 0.3.

Space shuttle orbit maneuvering engine reusable thrust chamber: Adverse operating conditions test report

NASA Technical Reports Server (NTRS)

Tobin, R. D.

1974-01-01

Test hardware, facilities, and procedures are described along with results of electrically heated tube and channel tests conducted to determine adverse operating condition limits for convectively cooled chambers typical of Space Shuttle Orbit Manuevering Engine designs. Hot-start tests were conducted with corrosion resistant steel and nickel tubes with both monomethylhydrazine and 50-50 coolants. Helium ingestion, in both bubble and froth form, was studied in tubular test sections. Helium bubble ingestion and burn-out limits in rectangular channels were also investigated.

Stereotype Threat: A Qualitative Study of the Challenges Facing Female Undergraduate Engineering Students

NASA Astrophysics Data System (ADS)

Entsminger, J. R., II

From a sociocultural point of view, this qualitative case study explored how upper-level, female undergraduate engineering students perceived the possibility of or experience with stereotype threat as shaping their experiences. The study also investigated how these students explained their reasons for choosing their engineering major, the challenges they encountered in the major, and their reasons for persevering in spite of those challenges. Using Steele and Aronson's (1995) stereotype threat theory as a framework, and considering the documented underrepresentation of females in engineering, the study sought to examine how stereotype threat shaped the experiences of these students and if stereotype threat could be considered a valid reason for the underrepresentation. The study was conducted at a large, four-year public university. First, students in the College of Engineering and Engineering Technology completed the Participant Screening Survey. Based on responses from the survey, six female engineering students from the college were identified and invited to participate in the study. The participants came from the following majors: Electrical Engineering, Industrial and Systems Engineering, and Mechanical Engineering. After receiving the study consent letter and agreeing to participate, the students were involved in a 90-minute focus group meeting, a 45-minute one-on-one interview, and a 30-minute follow-up interview. After conducting the data collection methods, the data were then transcribed, analyzed, and coded for theme development. The themes that emerged coincided with each research question. The themes highlighted the complex interactions and experiences shared by the female engineering majors. The female students were enveloped in an environment where there existed an increased risk for activating stereotype threat. In addition, the female students described feeling pushed to prove to themselves and to others that the negative stereotype that 'females are bad at engineering' was untrue. The findings illustrated the need for systematic changes at the university level. Intervention recommendations were provided. In regards to female underrepresentation in science fields, including engineering, stereotype threat certainly had the potential to cause the female students to question themselves, their abilities, their choice of an academic major, and subsequently remove themselves from a hostile learning or working environment. Thus, educational institutions and workplace organizations are responsible for not only educating themselves regarding stereotype threat, but also for taking steps to alleviate the pernicious effects of stereotype threat.

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

Shao, Huifang; Lam, William; Remias, Joseph

Mobile source emissions standards are becoming more stringent and particulate emissions from gasoline direct injection (GDI) engines represent a particular challenge. Gasoline particulate filter (GPF) is deemed as one possible technical solution for particulate emissions reduction. In this work, a study was conducted on eight formulations of lubricants to determine their effect on GDI engine particulate emissions and GPF performance. Accelerated ash loading tests were conducted on a 2.4L GDI engine with engine oil injection in gasoline fuel by 2%. The matrix of eight formulations was designed with changing levels of sulfated ash (SASH) level, Zinc dialkyldithiophosphates (ZDDP) level andmore » detergent type. Comprehensive evaluations of particulates included mass, number, size distribution, composition, morphology and soot oxidation properties. GPF performance was assessed through filtration efficiency, back pressure and morphology. It was determined that oil formulation affects the particulate emission characteristics and subsequent GPF performance.« less

Research approach to teaching groundwater biodegradation in karst aquifers

USGS Publications Warehouse

King, L.; Byl, T.; Painter, R.

2006-01-01

TSU in partnership with the USGS has conducted extensive research regarding biode??gradation of contaminants in karst aquifers. This research resulted in the development of a numerical approach to modeling biodegradation of contaminants in karst aquifers that is taught to environmental engineering students in several steps. First, environmental engineering students are taught chemical-reaction engineering principles relating to a wide variety of environmental fate and transport issues. Second, as part of TSU's engineering course curriculum, students use a non-ideal flow laboratory reactor system and run a tracer study to establish residence time distribution (RTD). Next, the students couple that formula to a first-order biodegradation rate and predict the removal of a biodegradable contaminant as a function of residence time. Following this, students are shown data collected from karst bedrock wells that suggest that karst aquifers are analogous to non-ideal flow reactors. The students are challenged to develop rates of biodegradation through lab studies and use their results to predict biodegradaton at an actual contaminated karst site. Field studies are also conducted to determine the accuracy of the students' predictions. This academic approach teaches biodegradation processes, rate-kinetic processes, hydraulic processes and numerical principles. The students are able to experience how chemical engineering principles can be applied to other situations, such as, modeling biodegradation of contaminants in karst aquifers. This paper provides background on the chemical engineering principles and karst issues used in the research-enhanced curriculum. ?? American Society for Engineering Education, 2006.

US nuclear engineering education: Status and prospects

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

Not Available

1990-01-01

This study, conducted under the auspices of the Energy Engineering Board of the National Research Council, examines the status of and outlook for nuclear engineering education in the United States. The study resulted from a widely felt concern about the downward trends in student enrollments in nuclear engineering, in both graduate and undergraduate programs. Concerns have also been expressed about the declining number of US university nuclear engineering departments and programs, the aging of their faculties, the appropriateness of their curricula and research funding for industry and government needs, the availability of scholarships and research funding, and the increasing ratiomore » of foreign to US graduate students. A fundamental issue is whether the supply of nuclear engineering graduates will be adequate for the future. Although such issues are more general, pertaining to all areas of US science and engineering education, they are especially acute for nuclear engineering education. 30 refs., 12 figs., 20 tabs.« less

Alternate space shuttle concepts study. Part 2: Technical summary. Volume 2: Orbiter definition

NASA Technical Reports Server (NTRS)

1971-01-01

A study was conducted of a three-engined external hydrogen tank orbiter/heat sink booster utilizing 415 K sea level thrust engines. The results of the study, pertaining to the orbiter portion of the configuration, are presented. A complete summary of characteristics is given for the external tank configuration along with some comparative data for a conventional internal tank configuration.

Genetic engineering of somatic cells to study and improve cardiac function.

PubMed

Kirkton, Robert D; Bursac, Nenad

2012-11-01

To demonstrate the utility of genetically engineered excitable cells for studies of basic electrophysiology and cardiac cell therapy. 'Zig-zag' networks of neonatal rat ventricular myocytes (NRVMs) were micropatterned onto thin elastomeric films to mimic the slow action potential (AP) conduction found in fibrotic myocardium. Addition of genetically engineered excitable human embryonic kidney cells (HEK-293 cells) ('Ex-293' cells stably expressing Kir2.1, Na(v)1.5, and Cx43 channels) increased both cardiac conduction velocity by 370% and twitch force amplitude by 64%. Furthermore, we stably expressed mutant Na(v)1.5 [A1924T (fast sodium channel mutant (substitution of alanine by threonine at amino acid 1924)] channels with hyperpolarized steady-state activation and showed that, despite a 71.6% reduction in peak I(Na), these cells propagated APs at the same velocity as the wild-type Na(v)1.5-expressing Ex-293 cells. Stable expression of Ca(v)3.3 (T-type voltage-gated calcium) channels in Ex-293 cells (to generate an 'ExCa-293' line) significantly increased their AP duration and reduced repolarization gradients in cocultures of these cells and NRVMs. Additional expression of an optogenetic construct [ChIEF (light-gated Channelrhodopsin mutant)]enabled light-based control of AP firing in ExCa-293 cells. We show that, despite being non-contractile, genetically engineered excitable cells can significantly improve both electrical and mechanical function of engineered cardiac tissues in vitro. We further demonstrate the utility of engineered cells for tissue-level studies of basic electrophysiology and cardiac channelopathies. In the future, this novel platform could be utilized in the high-throughput design of new genetically encoded indicators of cell electrical function, validation, and improvement of computer models of AP conduction, and development of novel engineered somatic cell therapies for the treatment of cardiac infarction and arrhythmias.

3D conductive nanocomposite scaffold for bone tissue engineering

PubMed Central

Shahini, Aref; Yazdimamaghani, Mostafa; Walker, Kenneth J; Eastman, Margaret A; Hatami-Marbini, Hamed; Smith, Brenda J; Ricci, John L; Madihally, Sundar V; Vashaee, Daryoosh; Tayebi, Lobat

2014-01-01

Bone healing can be significantly expedited by applying electrical stimuli in the injured region. Therefore, a three-dimensional (3D) ceramic conductive tissue engineering scaffold for large bone defects that can locally deliver the electrical stimuli is highly desired. In the present study, 3D conductive scaffolds were prepared by employing a biocompatible conductive polymer, ie, poly(3,4-ethylenedioxythiophene) poly(4-styrene sulfonate) (PEDOT:PSS), in the optimized nanocomposite of gelatin and bioactive glass. For in vitro analysis, adult human mesenchymal stem cells were seeded in the scaffolds. Material characterizations using hydrogen-1 nuclear magnetic resonance, in vitro degradation, as well as thermal and mechanical analysis showed that incorporation of PEDOT:PSS increased the physiochemical stability of the composite, resulting in improved mechanical properties and biodegradation resistance. The outcomes indicate that PEDOT:PSS and polypeptide chains have close interaction, most likely by forming salt bridges between arginine side chains and sulfonate groups. The morphology of the scaffolds and cultured human mesenchymal stem cells were observed and analyzed via scanning electron microscope, micro-computed tomography, and confocal fluorescent microscope. Increasing the concentration of the conductive polymer in the scaffold enhanced the cell viability, indicating the improved microstructure of the scaffolds or boosted electrical signaling among cells. These results show that these conductive scaffolds are not only structurally more favorable for bone tissue engineering, but also can be a step forward in combining the tissue engineering techniques with the method of enhancing the bone healing by electrical stimuli. PMID:24399874

3D conductive nanocomposite scaffold for bone tissue engineering.

PubMed

Shahini, Aref; Yazdimamaghani, Mostafa; Walker, Kenneth J; Eastman, Margaret A; Hatami-Marbini, Hamed; Smith, Brenda J; Ricci, John L; Madihally, Sundar V; Vashaee, Daryoosh; Tayebi, Lobat

2014-01-01

Bone healing can be significantly expedited by applying electrical stimuli in the injured region. Therefore, a three-dimensional (3D) ceramic conductive tissue engineering scaffold for large bone defects that can locally deliver the electrical stimuli is highly desired. In the present study, 3D conductive scaffolds were prepared by employing a biocompatible conductive polymer, ie, poly(3,4-ethylenedioxythiophene) poly(4-styrene sulfonate) (PEDOT:PSS), in the optimized nanocomposite of gelatin and bioactive glass. For in vitro analysis, adult human mesenchymal stem cells were seeded in the scaffolds. Material characterizations using hydrogen-1 nuclear magnetic resonance, in vitro degradation, as well as thermal and mechanical analysis showed that incorporation of PEDOT:PSS increased the physiochemical stability of the composite, resulting in improved mechanical properties and biodegradation resistance. The outcomes indicate that PEDOT:PSS and polypeptide chains have close interaction, most likely by forming salt bridges between arginine side chains and sulfonate groups. The morphology of the scaffolds and cultured human mesenchymal stem cells were observed and analyzed via scanning electron microscope, micro-computed tomography, and confocal fluorescent microscope. Increasing the concentration of the conductive polymer in the scaffold enhanced the cell viability, indicating the improved microstructure of the scaffolds or boosted electrical signaling among cells. These results show that these conductive scaffolds are not only structurally more favorable for bone tissue engineering, but also can be a step forward in combining the tissue engineering techniques with the method of enhancing the bone healing by electrical stimuli.

Supporting clinical engineering in Italy: results of a survey conducted by the AIIC.

PubMed

Faggiano, Francesco; Ritrovato, Matteo; Freda, Paola; Vivo, Liliana; D'Alessandro, Luigi; Derrico, Pietro

2012-01-01

This article presents the outcomes of a survey developed and conducted by the Italian Association of Clinical Engineers (AIIC) in 2010 [1]. The AIIC, affiliated with the International Federation for Medical and Biological Engineering (IFMBE) since 2003, conducted this in-depth survey to investigate the educational profile of clinical engineers (CEs) as well as the activities and organization of clinical engineering departments (CEDs) in Italy. The survey consisted of a six-section questionnaire designed by the AIIC Board, which was based on other previous international surveys of CEDs. The questionnaire was sent to the AIIC members and to the most important Italian health-care organizations.

Forecasting Climate-Induced Ecosystem Changes on Army Installations

DTIC Science & Technology

2011-10-01

W. Hargrove Construction Engineering Research Laboratory (CERL) US Army Engineer Research and Development Center 2902 Newmark Dr. Champaign, IL...unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/CERL TR-11-36...35 ERDC/CERL TR-11-36 v Preface This study was conducted for Dr. Jeffrey Holland, Director of the Engineer Research and Development

Establishment of first engineering specifications for environmental modification to eliminate schistosomiasis epidemic foci in urban areas.

PubMed

Kong, Shibo; Tan, Xiaodong; Deng, Zhiqing; Xie, Yaofei; Yang, Fen; Zheng, Zengwang

2017-08-01

Snail control is a key link in schistosomiasis control, but no unified methods for eliminating snails have been produced to date. This study was conducted to explore an engineering method for eliminating Oncomelania hupensis applicable to urban areas. The engineering specifications were established using the Delphi method. An engineering project based on these specifications was conducted in Hankou marshland to eliminate snails, including the transformation of the beach surface and ditches. Molluscicide was used as a supplement. The snail control effect was evaluated by field investigation. The engineering results fulfilled the requirements of the design. The snail density decreased to 0/0.11m 2 , and the snail area dropped to 0m 2 after the project. There was a statistically significant difference in the number of frames with snails before and after the project (P<0.05). Snails were completely eliminated through one year of continuous monitoring, and no new snails were found after a flood disaster. This study demonstrates that engineering specifications for environmental modification were successfully established. Environmental modification, mainly through beach and ditch remediation, can completely change the environment of Oncomelania breeding. This method of environmental modification combined with mollusciciding was highly effective at eliminating snails. Copyright © 2017 Elsevier B.V. All rights reserved.

Revolutionary opportunities for materials and structures study, addendum

NASA Technical Reports Server (NTRS)

Feig, P. D.

1987-01-01

This report is an addendum to the Revolutionary Opportunities for Materials and Structures Study (ROMS), modifying the original by the addition of two tasks. The primary purpose of these tasks was to conduct additional aircraft/engine sizing and mission analysis to obtain contributory aircraft performance data such as fuel burns and direct operating costs for both the subsonic and supersonic engines.

Engine design considerations for 2nd generation supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.

1975-01-01

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

Energy Efficient Engine (E3) combustion system component technology performance report

NASA Technical Reports Server (NTRS)

Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

1984-01-01

The Energy Efficient Engine (E3) combustor effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent of this effort was to evolve a design that meets the stringent emissions and life goals of the E3, as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this effort was incorporated into the engine combustion hardware design. The advanced engine combustion system was then evaluated in component testing to verify the design intent. What evolved from this effort was an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3.

Preliminary scramjet design for hypersonic airbreathing missile application

NASA Technical Reports Server (NTRS)

Carlson, C. H.

1983-01-01

A conceptual design study of a scramjet engine was conducted for a hypersonic surface to air missile (HYSAM). The definition of the engine was based upon the requirements of accelerating the HYSAM from Mach 4 at 20,000 feet to Mach 6 at 100,000 feet and the cruise conditions at Mach 6. The resulting external and internal environmental conditions were used by various engineering disciplines performing design, stress and heat transfer analysis. A detailed structural analysis was conducted along with an indepth thermal analysis. Structurally all the components within the system exhibit positive margins of safety. A feasible concept was defined which uses state-of-the-art materials and existing TMC technology. The engine basically consists of a three dimensional carbon/carbon combustor/nozzle secured to an FS-85 columbium inlet. The carbon/carbon liner is sheathed with carbon felt insulation to thermally protect the FS-85 structure and skin. The thermal analysis of the engine indicates that a thermally viable configuration exists.

Study of solid rocket motors for a space shuttle booster. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

An analysis of the solid propellant rocket engines for use with the space shuttle booster was conducted. A definition of the specific solid propellant rocket engine stage designs, development program requirements, production requirements, launch requirements, and cost data for each program phase were developed.

Teresa Barnes, Ph.D. | NREL

Science.gov Websites

Engineering, Colorado School of Mines B.S. Chemical Engineering, University of Maryland Featured Publications studied plasma-assisted chemical vapor deposition chemistry and transparent conducting oxide growth as a exploring the fundamental limits of CdTe performance using molecular beam epitaxy. Education Ph.D. Chemical

Pedagogical Evaluation of Remote Laboratories in eMerge Project

ERIC Educational Resources Information Center

Lang, Daniela; Mengelkamp, Christoph; Jaeger, Reinhold S.; Geoffroy, Didier; Billaud, Michel; Zimmer, Thomas

2007-01-01

This study investigates opportunities for conducting electrical engineering experiments via the Internet rather than in an actual laboratory. Eighty-four French students of electrical engineering (semester 1, 2004) at Bordeaux University 1 participated in practical courses. Half of the students performed experiments in a laboratory while the other…

Experimental Study on an Unsteady Pressure Gain Combustion Hypergolic Rocket Engine Concept

NASA Astrophysics Data System (ADS)

Kan, Brandon K.

An experimental study is conducted to investigate pulsed combustion in a lab-scale bipropellant rocket engine using hypergolic propellants. The propellant combination is high concentration hydrogen peroxide and a catalyst-laced triglyme fuel. A total of 50 short duration firings have been conducted; the vast majority in an open-chamber configuration. High amplitude pulsations were evident in nearly all cases and have been assessed with high frequency pressure measurements. Both pintle and unlike impinging quadlet injector types have been evaluated although the bulk of the testing was with the latter configuration. Several firings were conducted with a transparent chamber in an attempt to gain understanding using a high-speed camera in the visible spectrum. Peak chamber pressures in excess of 5000 psi have been recorded with surface mounted high frequency gages with pulsation frequencies exceeding 600 Hz. A characterization of time-averaged performance is made for the unsteady system, where time-resolved thrust and pressure measurements were attempted. While prior literature describes this system as a pulse detonation rocket engine, the combustion appears to be more "constant volume" in nature.

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.

Some engineering aspects of homoionized mixed clay minerals.

PubMed

Oren, Ali Hakan; Kaya, Abidin

2003-05-01

Many studies have been conducted to investigate the physicochemical behavior of pure clay minerals and predict their engineering performance in the field. In this study, the physicochemical properties of an artificial mixture of different clay minerals namely, 40-50% montmorillonite, 20-30% illite and 10-15% kaolin were investigated. The mixture was homoionized with sodium, Na+; calcium, Ca2+; and aluminum, Al3+. The engineering properties studied were consistency limits, sediment volume, compressibility behavior, and hydraulic conductivity. The results revealed that the liquid, plastic and shrinkage limits of soil increased with increasing cation valence. The hydraulic conductivity of the soil also increased with an increase in the valence of the cation at any given void ratio. Aluminum and sodium treated clays had the highest and the lowest modified compression index values, respectively. Furthermore, trivalent cation saturated clayey soil consolidates three times faster than that of monovalent and two times faster than that of divalent. These properties of the soils determined were, in general, similar to those of kaolinite rather than those of montmorillonite. The comparison of the results obtained with the published data in the literature revealed that the physicochemical behavior of the tested clay soil was, in general, similar to that of kaolinite.

The hard start phenomena in hypergolic engines. Volume 5: RCS engine deformation and destruct tests

NASA Technical Reports Server (NTRS)

Miron, Y.; Perlee, H. E.

1974-01-01

Tests were conducted to determine the causes of Apollo Reaction Control (RCS) engine failures. Stainless steel engines constructed for use in the destructive tests are described. The tests conducted during the three phase investigation are discussed. It was determined that the explosive reaction that destroys the RCS engines occurs at the time of engine ignition and is apparently due to either the detonation of the heterogeneous constituents of the rocket engine, consisting primarily of unreacted propellant droplets and vapors, and/or the detonation of explosive materials accumulated on the engine walls from previous pulses. Photographs of the effects of explosions on the simulated RCS engines are provided.

Near-field three-terminal thermoelectric heat engine

NASA Astrophysics Data System (ADS)

Jiang, Jian-Hua; Imry, Yoseph

2018-03-01

We propose a near-field inelastic thermoelectric heat engine where quantum dots are used to effectively rectify the charge flow of photocarriers. The device converts near-field heat radiation into useful electrical power. Heat absorption and inelastic transport can be enhanced by introducing two continuous spectra separated by an energy gap. The thermoelectric transport properties of the heat engine are studied in the linear-response regime. Using a small band-gap semiconductor as the absorption material, we show that the device achieves very large thermopower and thermoelectric figure of merit, as well as considerable power factor. By analyzing thermal-photocarrier generation and conduction, we reveal that the Seebeck coefficient and the figure of merit have oscillatory dependence on the thickness of the vacuum gap. Meanwhile, the power factor, the charge, and thermal conductivity are significantly improved by near-field radiation. Conditions and guiding principles for powerful and efficient thermoelectric heat engines are discussed in details.

Combustion Stability Verification for the Thrust Chamber Assembly of J-2X Developmental Engines 10001, 10002, and 10003

NASA Technical Reports Server (NTRS)

Morgan, C. J.; Hulka, J. R.; Casiano, M. J.; Kenny, R. J.; Hinerman, T. D.; Scholten, N.

2015-01-01

The J-2X engine, a liquid oxygen/liquid hydrogen propellant rocket engine available for future use on the upper stage of the Space Launch System vehicle, has completed testing of three developmental engines at NASA Stennis Space Center. Twenty-one tests of engine E10001 were conducted from June 2011 through September 2012, thirteen tests of the engine E10002 were conducted from February 2013 through September 2013, and twelve tests of engine E10003 were conducted from November 2013 to April 2014. Verification of combustion stability of the thrust chamber assembly was conducted by perturbing each of the three developmental engines. The primary mechanism for combustion stability verification was examining the response caused by an artificial perturbation (bomb) in the main combustion chamber, i.e., dynamic combustion stability rating. No dynamic instabilities were observed in the TCA, although a few conditions were not bombed. Additional requirements, included to guard against spontaneous instability or rough combustion, were also investigated. Under certain conditions, discrete responses were observed in the dynamic pressure data. The discrete responses were of low amplitude and posed minimal risk to safe engine operability. Rough combustion analyses showed that all three engines met requirements for broad-banded frequency oscillations. Start and shutdown transient chug oscillations were also examined to assess the overall stability characteristics, with no major issues observed.

TOPSIS-based parametric optimization of compression ignition engine performance and emission behavior with bael oil blends for different EGR and charge inlet temperature.

PubMed

Muniappan, Krishnamoorthi; Rajalingam, Malayalamurthi

2018-05-02

The demand for higher fuel energy and lesser exhaust emissions of diesel engines can be achieved by fuel being used and engine operating parameters. In the present work, effects of engine speed (RPM), injection timing (IT), injection pressure (IP), and compression ratio (CR) on performance and emission characteristics of a compression ignition (CI) engine were investigated. The ternary test fuel of 65% diesel + 25% bael oil + 10% diethyl ether (DEE) was used in this work and test was conducted at different charge inlet temperature (CIT) and exhaust gas recirculation (EGR). All the experiments are conducted at the tradeoff engine load that is 75% engine load. When operating the diesel engine with 320 K CIT, brake thermal efficiency (BTE) is improved to 28.6%, and carbon monoxide (CO) and hydrocarbon (HC) emissions have been reduced to 0.025% and 12.5 ppm at 18 CR. The oxide of nitrogen (NOx) has been reduced to 240 ppm at 1500 rpm for 30% EGR mode. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is frequently used in multi-factor selection and gray correlation analysis method is used to study uncertain of the systems.

Evaluation of Game Engines for Cross-Platform Development of Mobile Serious Games for Health.

PubMed

Kleinschmidt, Carina; Haag, Martin

2016-01-01

Studies have shown that serious games for health can improve patient compliance and help to increase the quality of medical education. Due to a growing availability of mobile devices, especially the development of cross-platform mobile apps is helpful for improving healthcare. As the development can be highly time-consuming and expensive, an alternative development process is needed. Game engines are expected to simplify this process. Therefore, this article examines the question whether using game engines for cross-platform serious games for health can simplify the development compared to the development of a plain HTML5 app. At first, a systematic review of the literature was conducted in different databases (MEDLINE, ACM and IEEE). Afterwards three different game engines were chosen, evaluated in different categories and compared to the development of a HTML5 app. This was realized by implementing a prototypical application in the different engines and conducting a utility analysis. The evaluation shows that the Marmalade engine is the best choice for development in this scenario. Furthermore, it is obvious that the game engines have great benefits against plain HTML5 development as they provide components for graphics, physics, sounds, etc. The authors recommend to use the Marmalade Engine for a cross-platform mobile Serious Game for Health.

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

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

Energy efficient engine preliminary design and integration study

NASA Technical Reports Server (NTRS)

Gray, D. E.

1978-01-01

The technology and configurational requirements of an all new 1990's energy efficient turbofan engine having a twin spool arrangement with a directly coupled fan and low-pressure turbine, a mixed exhaust nacelle, and a high 38.6:1 overall pressure ratio were studied. Major advanced technology design features required to provide the overall benefits were a high pressure ratio compression system, a thermally actuated advanced clearance control system, lightweight shroudless fan blades, a low maintenance cost one-stage high pressure turbine, a short efficient mixer and structurally integrated engine and nacelle. A conceptual design analysis was followed by integration and performance analyses of geared and direct-drive fan engines with separate or mixed exhaust nacelles to refine previously designed engine cycles. Preliminary design and more detailed engine-aircraft integration analysis were then conducted on the more promising configurations. Engine and aircraft sizing, fuel burned, and airframe noise studies on projected 1990's domestic and international aircraft produced sufficient definition of configurational and advanced technology requirements to allow immediate initiation of component technology development.

Characterizing adoption of precautionary risk management guidance for nanomaterials, an emerging occupational hazard.

PubMed

Schubauer-Berigan, Mary K; Dahm, Matthew M; Schulte, Paul A; Hodson, Laura; Geraci, Charles L

2015-01-01

Exposure to engineered nanomaterials (substances with at least one dimension of 1-100 nm) has been of increased interest, with the recent growth in production and use of nanomaterials worldwide. Various organizations have recommended methods to minimize exposure to engineered nanomaterials. The purpose of this study was to evaluate available data to examine the extent to which studied U.S. companies (which represent a small fraction of all companies using certain forms of engineered nanomaterials) follow the guidelines for reducing occupational exposures to engineered nanomaterials that have been issued by the National Institute for Occupational Safety and Health (NIOSH) and other organizations. Survey data, field reports, and field notes for all NIOSH nanomaterial exposure assessments conducted between 2006 and 2011 were collected and reviewed to: (1) determine the level of adoption of precautionary guidance on engineering controls and personal protective equipment (PPE), and (2) evaluate the reliability of companies' self-reported use of engineering controls and PPE. Use of PPE was observed among 89% [95% confidence interval (CI): 76%-96%] of 46 visited companies, and use of containment-based engineering controls for at least some processes was observed among 83% (95% CI: 76%-96%). In on-site evaluations, more than 90% of the 16 engineered carbonaceous nanomaterial companies that responded to an industrywide survey were observed to be using engineering controls and PPE as reported or more stringently than reported. Since PPE use was slightly more prevalent than engineering controls, better communication may be necessary to reinforce the importance of the hierarchy of controls. These findings may also be useful in conducting exposure assessment and epidemiologic research among U.S. workers handling nanomaterials.

Thermal Expansion Behavior of Hot-Pressed Engineered Matrices

NASA Technical Reports Server (NTRS)

Raj, S. V.

2016-01-01

Advanced engineered matrix composites (EMCs) require that the coefficient of thermal expansion (CTE) of the engineered matrix (EM) matches those of the fiber reinforcements as closely as possible in order to reduce thermal compatibility strains during heating and cooling of the composites. The present paper proposes a general concept for designing suitable matrices for long fiber reinforced composites using a rule of mixtures (ROM) approach to minimize the global differences in the thermal expansion mismatches between the fibers and the engineered matrix. Proof-of-concept studies were conducted to demonstrate the validity of the concept.

Remediation of water and wastewater by using engineered nanomaterials: A review.

PubMed

Bishoge, Obadia K; Zhang, Lingling; Suntu, Shaldon L; Jin, Hui; Zewde, Abraham A; Qi, Zhongwei

2018-05-12

Nanotechnology is currently a fast-rising socioeconomic and political knowledge-based technology owing to the unique characteristics of its engineered nanomaterials. This branch of technology is useful for water and wastewater remediation. Many scientists and researchers have been conducting different studies and experiments on the applications of engineered nanomaterials at the local to international level. This review mainly aims to provide a current overview of existing knowledge on engineered nanomaterials and their applications in water and wastewater remediation. Furthermore, the present risks and challenges of nanotechnology are examined.

Subsonic longitudinal aerodynamic characteristics and engine pressure distributions for an aircraft with an integrated scramjet designed for Mach 6 cruise. [conducted in Langley 7 by 10 foot high speed tunnel

NASA Technical Reports Server (NTRS)

Huffman, J. K.; Fox, C. H., Jr.; Johnston, P. J.

1977-01-01

A 1/10-scale model of a proposed hypersonic aircraft with an integrated scramjet was tested. The investigation took place over a Mach number range from 0.2 to 0.7 and an angle of attack range from 2 deg to approximately 17 deg at a sideslip angle of 0 deg. The primary configuration variables studied were engine location, internal engine geometry, and external engine geometry. The results are presented without analysis.

Atomic Force Microscope

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

Day, R.D.; Russell, P.E.

The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

Engineering students' experiences and perceptions of workplace problem solving

NASA Astrophysics Data System (ADS)

Pan, Rui

In this study, I interviewed 22 engineering Co-Op students about their workplace problem solving experiences and reflections and explored: 1) Of Co-Op students who experienced workplace problem solving, what are the different ways in which students experience workplace problem solving? 2) How do students perceive a) the differences between workplace problem solving and classroom problem solving and b) in what areas are they prepared by their college education to solve workplace problems? To answer my first research question, I analyzed data through the lens of phenomenography and I conducted thematic analysis to answer my second research question. The results of this study have implications for engineering education and engineering practice. Specifically, the results reveal the different ways students experience workplace problem solving, which provide engineering educators and practicing engineers a better understanding of the nature of workplace engineering. In addition, the results indicate that there is still a gap between classroom engineering and workplace engineering. For engineering educators who aspire to prepare students to be future engineers, it is imperative to design problem solving experiences that can better prepare students with workplace competency.

Understanding the Role of Academic Language on Conceptual Understanding in an Introductory Materials Science and Engineering Course

NASA Astrophysics Data System (ADS)

Kelly, Jacquelyn

Students may use the technical engineering terms without knowing what these words mean. This creates a language barrier in engineering that influences student learning. Previous research has been conducted to characterize the difference between colloquial and scientific language. Since this research had not yet been applied explicitly to engineering, conclusions from the area of science education were used instead. Various researchers outlined strategies for helping students acquire scientific language. However, few examined and quantified the relationship it had on student learning. A systemic functional linguistics framework was adopted for this dissertation which is a framework that has not previously been used in engineering education research. This study investigated how engineering language proficiency influenced conceptual understanding of introductory materials science and engineering concepts. To answer the research questions about engineering language proficiency, a convenience sample of forty-one undergraduate students in an introductory materials science and engineering course was used. All data collected was integrated with the course. Measures included the Materials Concept Inventory, a written engineering design task, and group observations. Both systemic functional linguistics and mental models frameworks were utilized to interpret data and guide analysis. A series of regression analyses were conducted to determine if engineering language proficiency predicts group engineering term use, if conceptual understanding predicts group engineering term use, and if conceptual understanding predicts engineering language proficiency. Engineering academic language proficiency was found to be strongly linked to conceptual understanding in the context of introductory materials engineering courses. As the semester progressed, this relationship became even stronger. The more engineering concepts students are expected to learn, the more important it is that they are proficient in engineering language. However, exposure to engineering terms did not influence engineering language proficiency. These results stress the importance of engineering language proficiency for learning, but warn that simply exposing students to engineering terms does not promote engineering language proficiency.

Design study of an air pump and integral lift engine ALF-504 using the Lycoming 502 core

NASA Technical Reports Server (NTRS)

Rauch, D.

1972-01-01

Design studies were conducted for an integral lift fan engine utilizing the Lycoming 502 fan core with the final MQT power turbine. The fan is designed for a 12.5 bypass ratio and 1.25:1 pressure ratio, and provides supercharging for the core. Maximum sea level static thrust is 8370 pounds with a specific fuel consumption of 0.302 lb/hr-lb. The dry engine weight without starter is 1419 pounds including full-length duct and sound-attenuating rings. The engine envelope including duct treatment but not localized accessory protrusion is 53.25 inches in diameter and 59.2 inches long from exhaust nozzle exit to fan inlet flange. Detailed analyses include fan aerodynamics, fan and reduction gear mechanical design, fan dynamic analysis, engine noise analysis, engine performance, and weight analysis.

Design and analysis of linear oscillatory single-phase permanent magnet generator for free-piston stirling engine systems

NASA Astrophysics Data System (ADS)

Kim, Jeong-Man; Choi, Jang-Young; Lee, Kyu-Seok; Lee, Sung-Ho

2017-05-01

This study focuses on the design and analysis of a linear oscillatory single-phase permanent magnet generator for free-piston stirling engine (FPSE) systems. In order to implement the design of linear oscillatory generator (LOG) for suitable FPSEs, we conducted electromagnetic analysis of LOGs with varying design parameters. Then, detent force analysis was conducted using assisted PM. Using the assisted PM gave us the advantage of using mechanical strength by detent force. To improve the efficiency, we conducted characteristic analysis of eddy-current loss with respect to the PM segment. Finally, the experimental result was analyzed to confirm the prediction of the FEA.

Ice Crystal Icing Engine Testing in the NASA Glenn Research Center's Propulsion Systems Laboratory: Altitude Investigation

NASA Technical Reports Server (NTRS)

Oliver, Michael J.

2014-01-01

The National Aeronautics and Space Administration (NASA) conducted a full scale ice crystal icing turbofan engine test using an obsolete Allied Signal ALF502-R5 engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The test article used was the exact engine that experienced a loss of power event after the ingestion of ice crystals while operating at high altitude during a 1997 Honeywell flight test campaign investigating the turbofan engine ice crystal icing phenomena. The test plan included test points conducted at the known flight test campaign field event pressure altitude and at various pressure altitudes ranging from low to high throughout the engine operating envelope. The test article experienced a loss of power event at each of the altitudes tested. For each pressure altitude test point conducted the ambient static temperature was predicted using a NASA engine icing risk computer model for the given ambient static pressure while maintaining the engine speed.

An Examination of the Selection Criteria Used in the Architect-Engineer Selection Process of Air Force Base Civil Engineers.

DTIC Science & Technology

1987-09-01

overall goal of hiring highly qualified firms on a fair basis. In conducting this research and writing its report of findings, I have benefited greatly... it . Introduction................... . . ... .. .. ..... Overview.................. . . ... .. .. ... Background........ ...... .. .. ...... Focus of...the focus of the study, its purpose and justification, its specific objective, and the scope of the study’s application. Background In recent years

Computer-Assisted Learning in UK Engineering Degree Programmes: Lessons Learned from an Extensive Case Study Programme

ERIC Educational Resources Information Center

Rothberg, S. J.; Lamb, F. M.; Willis, L.

2006-01-01

This paper gives a synopsis of an extensive programme of case studies on real uses of computer-assisted learning (CAL) materials within UK engineering degree programmes. The programme was conducted between 2000 and 2003 and followed a questionnaire-based survey looking at CAL use in the UK and in Australia. The synopsis reveals a number of key…

Development of Alternative Continuing Educational Systems for Preventing the Technological Obsolescence of Air Force Scientists and Engineers. Volume 1. Basic Study.

ERIC Educational Resources Information Center

Slebodnick, Edward B.; And Others

Volume 1 of the study reports a work effort to define and give guidelines for the acquisition of cost-effective alternative continuing education (CE) systems to prevent the technological obsolescence of Air Force military scientific and engineering officer personnel. A detailed background survey of the problem was conducted using questionnaires,…

Identifying the challenging factors in the transition from colleges of engineering to employment

NASA Astrophysics Data System (ADS)

Baytiyeh, Hoda; Naja, Mohamad

2012-03-01

The transition from university to a career in engineering is a challenging process. This study examined the perceptions of engineering graduates regarding the difficulties they encountered in their transition from the university to the workplace. Lebanese practising engineers (n=217), living around the world, were surveyed to identify their current employment situations and their attitudes toward their academic preparation. Factor analysis revealed three main challenges facing engineering graduates: communication; responsibility; self-confidence. Seventeen interviews were conducted to gather information on ways to facilitate this transition. Comments reflected the need for better collaboration between engineering schools and engineering firms. The results will provide insight for engineering colleges, faculty members and administrators into the challenges faced by graduates and their aspirations for a smoother transition into employment.

Correlation between Sustainability Education and Engineering Students' Attitudes towards Sustainability

ERIC Educational Resources Information Center

Tang, Kuok Ho Daniel

2018-01-01

Purpose: The purpose of this study is to investigate the impacts of a sustainable development course on the beliefs, attitudes and intentions of a cohort of engineering students in a university in Miri, Malaysia, towards sustainability. Design/methodology/approach: Questionnaire survey was conducted among the cohort of students encompassing the…

Taking Engineering Design out for a Spin

ERIC Educational Resources Information Center

Crismond, David; Soobyiah, Mark; Cain, Ryan

2013-01-01

This article highlights what inquiry and design have in common, and what makes engineering design uniquely different from inquiry. A case study is presented that gives students practice in conducting fair-test experiments, in troubleshooting to learn how to make designs better, and in building science-based explanations for how things work. The…

Evaluation of the Science, Technology, and Engineering Leadership Program, Year Three

ERIC Educational Resources Information Center

Wolanin, Natalie; Wade, Julie

2014-01-01

The Office of Shared Accountability conducted an evaluation of the implementation of the third and final year (2012-2013) of the "Science, Technology, and Engineering Leadership Program" (STELP) in Montgomery County (Maryland) Public Schools (MCPS). Funding for STELP, including the evaluation study, is provided by a grant from the Howard…

A Comparative Study on Real Lab and Simulation Lab in Communication Engineering from Students' Perspectives

ERIC Educational Resources Information Center

Balakrishnan, B.; Woods, P. C.

2013-01-01

Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised…

Exploring Simulator Use in the Preparation of Chemical Engineers

ERIC Educational Resources Information Center

Yerrick, Randy; Lund, Carl; Lee, Yonghee

2013-01-01

In this manuscript, we report the impact of students' usage of a simulator in the preparation of chemical engineers. This case study was conducted using content pretest and posttests, survey questionnaires, interviews, classroom observations, and an analysis of students' written response to design problems. Results showed the use of simulator was…

"Star Power" for Teaching Professional Skills to Engineering Students

ERIC Educational Resources Information Center

Goh, Suk Meng

2012-01-01

The objective of this study is to evaluate the potential of a game called "Star Power" to teach professional skills to mechanical engineering undergraduates. The game was conducted as an activity in a final year Professional Practice unit. A survey in the form of a questionnaire was administered to participating students in the following…

Evaluation of the Science, Technology, and Engineering Leadership Program, Year Two

ERIC Educational Resources Information Center

Wolanin, Natalie L.; Wade, Julie H.

2013-01-01

The Office of Shared Accountability (OSA) conducted an evaluation of the implementation of the second year (2011-2012) of the Science, Technology, and Engineering Leadership Program (STELP) in Montgomery County (Maryland) Public Schools (MCPS). Funding for STELP, including the evaluation study, is provided by a grant from the Howard Hughes Medical…

Women Ph.D. Students in Engineering and a Nuanced Terrain: Avoiding and Revealing Gender

ERIC Educational Resources Information Center

Erickson, Shelley K.

2012-01-01

Tensions regarding gender emerged from interviews conducted with 20 women Ph.D. students. This article does not focus explicitly on the reasons for women's continued underrepresentation in engineering. Rather the students' explanations for underrepresentation serve as a case study with which to analyze their gendered experiences. They avoid freely…

Implementing a Recursive Retention Assessment System for Engineering Programs. AIR 2002 Forum Paper.

ERIC Educational Resources Information Center

Acker, Jon Charles; Hughes, William; Fendley, William R., Jr.

This study was conducted to ascertain the factors associated with attrition in engineering programs on all fronts. Academic underpreparedness, psychosocial variables, and their interconnectivity were examined. Subjects included all enrolled University of Alabama students, as of the spring term 2001, who at one time or another were classified as…

Computational studies of an intake manifold for restricted engine application

NASA Astrophysics Data System (ADS)

Prasetyo, Bagus Dwi; Ubaidillah, Maharani, Elliza Tri; Setyohandoko, Gabriel; Idris, Muhammad Idzdihar

2018-02-01

The Formula Society of Automotive Engineer (FSAE) student competition is an international contest for a vehicle that entirely designed and built by students from various universities. The engine design in the Formula SAE competition has to comply a tight regulation. Concerning the engine intake line, an air restrictor of circular cross-section less than 20 mm must be fitted between the throttle valve and the engine inlet. The throat is aimed to limit the engine air flow rate as it strongly influences the volumetric efficiency and then the maximum power. This article focuses on the design of the engine intake system of the Bengawan FSAE team vehicle to optimize the engine power output and its stability. The performance of engine intake system is studied through computational fluid dynamics (CFD). The objective of CFD is to know the pressure, velocity, and airflow of the air intake manifold for the best performance of the engine. The three-dimensional drawing of the intake manifold was made, and CFD simulation was conducted using ANSYS FLUENT. Two models were studied. The result shows that the different design produces a different value of the velocity of airflow and the kind of flow type.

Thermophysical Properties of Polymer Materials with High Thermal Conductivity

NASA Astrophysics Data System (ADS)

Lebedev, S. M.; Gefle, O. S.; Dneprovskii, S. N.; Amitov, E. T.

2015-06-01

Results of studies on the main thermophysical properties of new thermally conductive polymer materials are presented. It is shown that modification of polymer dielectrics by micron-sized fillers allows thermally conductive materials with thermal conductivity not less than 2 W/(m K) to be produced, which makes it possible to use such materials as cooling elements of various electrical engineering and semiconductor equipment and devices.

14 CFR 33.57 - General conduct of block tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of... that, if a separate engine is used for the endurance test it must be subjected to a calibration check...

14 CFR 33.57 - General conduct of block tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of... that, if a separate engine is used for the endurance test it must be subjected to a calibration check...

14 CFR 33.57 - General conduct of block tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of... that, if a separate engine is used for the endurance test it must be subjected to a calibration check...

14 CFR 33.57 - General conduct of block tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of... that, if a separate engine is used for the endurance test it must be subjected to a calibration check...

14 CFR 33.57 - General conduct of block tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of... that, if a separate engine is used for the endurance test it must be subjected to a calibration check...

A comparative study on real lab and simulation lab in communication engineering from students' perspectives

NASA Astrophysics Data System (ADS)

Balakrishnan, B.; Woods, P. C.

2013-05-01

Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised concerns among educators on the merits and shortcomings of both physical and simulation labs; at the same time, many arguments have been raised on the differences of both labs. Investigating the effectiveness of both labs is complicated, as there are multiple factors that should be considered. In view of this challenge, a study on students' perspectives on their experience related to key aspects on engineering laboratory exercise was conducted. In this study, the Visual Auditory Read and Kinetic model was utilised to measure the students' cognitive styles. The investigation was done through a survey among participants from Multimedia University, Malaysia. The findings revealed that there are significant differences for most of the aspects in physical and simulation labs.

Rocket-Based Combined Cycle Flowpath Testing for Modes 1 and 4

NASA Technical Reports Server (NTRS)

Rice, Tharen

2002-01-01

Under sponsorship of the NASA Glenn Research Center (NASA GRC), the Johns Hopkins University Applied Physics Laboratory (JHU/APL) designed and built a five-inch diameter, Rocket-Based Combined Cycle (RBCC) engine to investigate mode 1 and mode 4 engine performance as well as Mach 4 inlet performance. This engine was designed so that engine area and length ratios were similar to the NASA GRC GTX engine is shown. Unlike the GTX semi-circular engine design, the APL engine is completely axisymmetric. For this design, a traditional rocket thruster was installed inside of the scramjet flowpath, along the engine centerline. A three part test series was conducted to determine Mode I and Mode 4 engine performance. In part one, testing of the rocket thruster alone was accomplished and its performance determined (average Isp efficiency = 90%). In part two, Mode 1 (air-augmented rocket) testing was conducted at a nominal chamber pressure-to-ambient pressure ratio of 100 with the engine inlet fully open. Results showed that there was neither a thrust increment nor decrement over rocket-only thrust during Mode 1 operation. In part three, Mode 4 testing was conducted with chamber pressure-to-ambient pressure ratios lower than desired (80 instead of 600) with the inlet fully closed. Results for this testing showed a performance decrease of 20% as compared to the rocket-only testing. It is felt that these results are directly related to the low pressure ratio tested and not the engine design. During this program, Mach 4 inlet testing was also conducted. For these tests, a moveable centerbody was tested to determine the maximum contraction ratio for the engine design. The experimental results agreed with CFD results conducted by NASA GRC, showing a maximum geometric contraction ratio of approximately 10.5. This report details the hardware design, test setup, experimental results and data analysis associated with the aforementioned tests.

Overview of a stirling engine test project

NASA Technical Reports Server (NTRS)

Slaby, J. G.

1980-01-01

Tests were conducted on three Stirling engines ranging in size from 1.33 to 53 horsepower (1 to 40 kW). The tests were directed toward developing alternative, backup component concepts to improve engine efficiency and performance or to reduce costs. Some of the activities included investigating attractive concepts and materials for cooler-regenerator units, installing a jet impingement device on a Stirling engine to determine its potential for improved engine performance, and presenting performance maps for initial characterization of Stirling engines. The experiment results of the tests are presented along with predictions of results of future tests to be conducted on the Stirling engines.

US Nuclear Engineering Education: Status and prospects

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

Not Available

1990-01-01

This study, conducted under the auspices of the Energy Engineering Board of the National Research Council, examines the status of and outlook for nuclear engineering education in the United States. The study, as described in this report resulted from a widely felt concern about the downward trends in student enrollments in nuclear engineering, in both graduate and undergraduate programs. Concerns have also been expressed about the declining number of US university nuclear engineering departments and programs, the ageing of their faculties, the appropriateness of their curricula and research funding for industry and government needs, the availability of scholarships and researchmore » funding, and the increasing ratio of foreign to US graduate students. A fundamental issue is whether the supply of nuclear engineering graduates will be adequate for the future. Although such issues are more general, pertaining to all areas of US science and engineering education, they are especially acute for nuclear engineering education. 30 refs., 24 figs., 49 tabs.« less

NASA Systems Engineering Research Consortium: Defining the Path to Elegance in Systems

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Farrington, Phillip A.

2016-01-01

The NASA Systems Engineering Research Consortium was formed at the end of 2010 to study the approaches to producing elegant systems on a consistent basis. This has been a transformative study looking at the engineering and organizational basis of systems engineering. The consortium has engaged in a variety of research topics to determine the path to elegant systems. In the second year of the consortium, a systems engineering framework emerged which structured the approach to systems engineering and guided our research. This led in the third year to set of systems engineering postulates that the consortium is continuing to refine. The consortium has conducted several research projects that have contributed significantly to the understanding of systems engineering. The consortium has surveyed the application of the NASA 17 systems engineering processes, explored the physics and statistics of systems integration, and considered organizational aspects of systems engineering discipline integration. The systems integration methods have included system exergy analysis, Akaike Information Criteria (AIC), State Variable Analysis, Multidisciplinary Coupling Analysis (MCA), Multidisciplinary Design Optimization (MDO), System Cost Modelling, System Robustness, and Value Modelling. Organizational studies have included the variability of processes in change evaluations, margin management within the organization, information theory of board structures, social categorization of unintended consequences, and initial looks at applying cognitive science to systems engineering. Consortium members have also studied the bidirectional influence of policy and law with systems engineering.

NASA Systems Engineering Research Consortium: Defining the Path to Elegance in Systems

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Farrington, Phillip A.

2016-01-01

The NASA Systems Engineering Research Consortium was formed at the end of 2010 to study the approaches to producing elegant systems on a consistent basis. This has been a transformative study looking at the engineering and organizational basis of systems engineering. The consortium has engaged in a variety of research topics to determine the path to elegant systems. In the second year of the consortium, a systems engineering framework emerged which structured the approach to systems engineering and guided our research. This led in the third year to set of systems engineering postulates that the consortium is continuing to refine. The consortium has conducted several research projects that have contributed significantly to the understanding of systems engineering. The consortium has surveyed the application of the NASA 17 systems engineering processes, explored the physics and statistics of systems integration, and considered organizational aspects of systems engineering discipline integration. The systems integration methods have included system energy analysis, Akaike Information Criteria (AIC), State Variable Analysis, Multidisciplinary Coupling Analysis (MCA), Multidisciplinary Design Optimization (MDO), System Cost Modeling, System Robustness, and Value Modeling. Organizational studies have included the variability of processes in change evaluations, margin management within the organization, information theory of board structures, social categorization of unintended consequences, and initial looks at applying cognitive science to systems engineering. Consortium members have also studied the bidirectional influence of policy and law with systems engineering.

Jet aircraft engine exhaust emissions database development: Year 1990 and 2015 scenarios

NASA Technical Reports Server (NTRS)

Landau, Z. Harry; Metwally, Munir; Vanalstyne, Richard; Ward, Clay A.

1994-01-01

Studies relating to environmental emissions associated with the High Speed Civil Transport (HSCT) military jet and charter jet aircraft were conducted by McDonnell Douglas Aerospace Transport Aircraft. The report includes engine emission results for baseline 1990 charter and military scenario and the projected jet engine emissions results for a 2015 scenario for a Mach 1.6 HSCT charter and military fleet. Discussions of the methodology used in formulating these databases are provided.

Aerothermo-Structural Analysis of Low Cost Composite Nozzle/Inlet Components

NASA Technical Reports Server (NTRS)

Shivakumar, Kuwigai; Challa, Preeli; Sree, Dave; Reddy, D.

1999-01-01

This research is a cooperative effort among the Turbomachinery and Propulsion Division of NASA Glenn, CCMR of NC A&T State University, and the Tuskegee University. The NC A&T is the lead center and Tuskegee University is the participating institution. Objectives of the research were to develop an integrated aerodynamic, thermal and structural analysis code for design of aircraft engine components, such as, nozzles and inlets made of textile composites; conduct design studies on typical inlets for hypersonic transportation vehicles and setup standards test examples and finally manufacture a scaled down composite inlet. These objectives are accomplished through the following seven tasks: (1) identify the relevant public domain codes for all three types of analysis; (2) evaluate the codes for the accuracy of results and computational efficiency; (3) develop aero-thermal and thermal structural mapping algorithms; (4) integrate all the codes into one single code; (5) write a graphical user interface to improve the user friendliness of the code; (6) conduct test studies for rocket based combined-cycle engine inlet; and finally (7) fabricate a demonstration inlet model using textile preform composites. Tasks one, two and six are being pursued. Selected and evaluated NPARC for flow field analysis, CSTEM for in-depth thermal analysis of inlets and nozzles and FRAC3D for stress analysis. These codes have been independently verified for accuracy and performance. In addition, graphical user interface based on micromechanics analysis for laminated as well as textile composites was developed. Demonstration of this code will be made at the conference. A rocket based combined cycle engine was selected for test studies. Flow field analysis of various inlet geometries were studied. Integration of codes is being continued. The codes developed are being applied to a candidate example of trailblazer engine proposed for space transportation. A successful development of the code will provide a simpler, faster and user-friendly tool for conducting design studies of aircraft and spacecraft engines, applicable in high speed civil transport and space missions.

Damage Accumulation and Failure of Plasma-Sprayed Thermal Barrier Coatings under Thermal Gradient Cyclic Conditions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Ghosn, Louis J.; Miller, rober A.

2005-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. A fundamental understanding of the sintering and thermal cycling induced delamination of thermal barrier coating systems under engine-like heat flux conditions will potentially help to improve the coating temperature capability. In this study, a test approach is established to emphasize the real-time monitoring and assessment of the coating thermal conductivity, which can initially increase under the steady-state high temperature thermal gradient test due to coating sintering, and later decrease under the thermal gradient cyclic test due to coating cracking and delamination. Thermal conductivity prediction models have been established for a ZrO2-(7- 8wt%)Y2O3 model coating system in terms of heat flux, time, and testing temperatures. The coating delamination accumulation is then assessed based on the observed thermal conductivity response under the combined steady-state and cyclic thermal gradient tests. The coating thermal gradient cycling associated delaminations and failure mechanisms under simulated engine heat-flux conditions will be discussed in conjunction with the coating sintering and fracture testing results.

Oligoaniline-based conductive biomaterials for tissue engineering.

PubMed

Zarrintaj, Payam; Bakhshandeh, Behnaz; Saeb, Mohammad Reza; Sefat, Farshid; Rezaeian, Iraj; Ganjali, Mohammad Reza; Ramakrishna, Seeram; Mozafari, Masoud

2018-05-01

The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells' niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of injectable hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conductive biomaterials for tissue engineering and regenerative medicine applications. The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have systematically reviewed the critical role of oligoaniline-based conductive biomaterials in tissue engineering. Research on aniline oligomers is growing today opening new scenarios that expand the potential of these biomaterials from "traditional" treatments to a new era of tissue engineering. The conductivity of this class of biomaterials can be tailored similar to that of tissues/organs. To the best of our knowledge, this is the first review article in which such issue is systematically reviewed and critically discussed in the light of the existing literature. Undoubtedly, investigations on the use of oligoaniline-based conductive biomaterials in tissue engineering need further advancement and a lot of critical questions are yet to be answered. In this review, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints for further development. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Small Engine Component Technology (SECT)

NASA Technical Reports Server (NTRS)

Early, M.; Dawson, R.; Zeiner, P.; Turk, M.; Benn, K.

1986-01-01

A study of small gas turbine engines was conducted to identify high payoff technologies for year-2000 engines and to define companion technology plans. The study addressed engines in the 186 to 746 KW (250 to 1000 shp) or equivalent thrust range for rotorcraft, commuter (turboprop), cruise missile (turbojet), and APU applications. The results show that aggressive advancement of high payoff technologies can produce significant benefits, including reduced SFC, weight, and cost for year-2000 engines. Mission studies for these engines show potential fuel burn reductions of 22 to 71 percent. These engine benefits translate into reductions in rotorcraft and commuter aircraft direct operating costs (DOC) of 7 to 11 percent, and in APU-related DOCs of 37 to 47 percent. The study further shows that cruise missile range can be increased by as much as 200 percent (320 percent with slurry fuels) for a year-2000 missile-turbojet system compared to a current rocket-powered system. The high payoff technologies were identified and the benefits quantified. Based on this, technology plans were defined for each of the four engine applications as recommended guidelines for further NASA research and technology efforts to establish technological readiness for the year 2000.

Comparison ofdvanced turboprop interior noise control ground and flight test data

NASA Technical Reports Server (NTRS)

Simpson, Myles A.; Tran, Boi N.

1992-01-01

Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight sts with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

Comparison ofdvanced turboprop interior noise control ground and flight test data

NASA Astrophysics Data System (ADS)

Simpson, Myles A.; Tran, Boi N.

Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight sts with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2016-01-01

High energy propellants for human lunar missions are analyzed, focusing on very advanced ozone and atomic hydrogen. One of the most advanced launch vehicle propulsion systems, such as the Space Shuttle Main Engine (SSME), used hydrogen and oxygen and had a delivered specific impulse of 453 seconds. In the early days of the space program, other propellants (or so called metapropellants) were suggested, including atomic hydrogen and liquid ozone. Theoretical and experimental studies of atomic hydrogen and ozone were conducted beginning in the late 1940s. This propellant research may have provided screenwriters with the idea of an atomic hydrogen-ozone rocket engine in the 1950 movie, Rocketship X-M. This paper presents analyses showing that an atomic hydrogen-ozone rocket engine could produce a specific impulse over a wide range of specific impulse values reaching as high as 1,600 seconds. A series of single stage and multistage rocket vehicle analyses were conducted to find the minimum specific impulse needed to conduct high energy round trip lunar missions.

Propulsion Estimates for High Energy Lunar Missions Using Future Propellants

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan A.; Bennett, Gary L.

2016-01-01

High energy propellants for human lunar missions are analyzed, focusing on very advanced ozone and atomic hydrogen. One of the most advanced launch vehicle propulsion systems, such as the Space Shuttle Main Engine (SSME), used hydrogen and oxygen and had a delivered specific impulse of 453 seconds. In the early days of the space program, other propellants (or so called metapropellants) were suggested, including atomic hydrogen and liquid ozone. Theoretical and experimental studies of atomic hydrogen and ozone were conducted beginning in the late 1940s. This propellant research may have provided screenwriters with the idea of an atomic hydrogen-ozone rocket engine in the 1950 movie, Rocketship X-M. This paper presents analyses showing that an atomic hydrogen-ozone rocket engine could produce a specific impulse over a wide range of specific impulse values reaching as high as 1,600 s. A series of single stage and multistage rocket vehicle analyses were conducted to find the minimum specific impulse needed to conduct high energy round trip lunar missions.

Corruption: Engineers are Victims, Perpetrators or Both?

PubMed

Pecujlija, M; Cosic, I; Nesic-Grubic, L; Drobnjak, S

2015-08-01

This study was conducted in Serbian companies on licensed engineers and in its first part included a total of 336 licensed engineers who voluntarily completed the questionnaires about their ethical orientation and attitudes toward corruption and in the second part 214 engineers who participated in the first survey, who voluntarily evaluated their company's business operations characteristics. This study has clearly shown that there is a direct significant influence of the engineer's ethical orientations and attitudes toward corruption on their evaluation of the characteristics of their respective companies regarding business operations. This research also clearly shows that only engineers with a strong deontological orientation, low ethical subjectivity, and strong readiness to fight corruption, low corruption acceptance and high awareness of corruption can successfully fight corruption, improve the business operations of their companies and make beneficial changes to society. Otherwise, they should be considered as corruption perpetrators, not just as its victims.

Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

2016-01-01

The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06602f

14 CFR 93.123 - High density traffic airports.

Code of Federal Regulations, 2014 CFR

2014-01-01

... operations conducted by air carriers with turboprop and reciprocating engine aircraft having a certificated... of operations conducted by air carriers with turboprop and reciprocating engine aircraft having a...

14 CFR 93.123 - High density traffic airports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... operations conducted by air carriers with turboprop and reciprocating engine aircraft having a certificated... of operations conducted by air carriers with turboprop and reciprocating engine aircraft having a...

14 CFR 93.123 - High density traffic airports.

Code of Federal Regulations, 2012 CFR

2012-01-01

... operations conducted by air carriers with turboprop and reciprocating engine aircraft having a certificated... of operations conducted by air carriers with turboprop and reciprocating engine aircraft having a...

Progress on Variable Cycle Engines

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.; Howlett, R. A.; Lohmann, R. P.

1979-01-01

Progress in the development and future requirements of the Variable Stream Control Engine (VSCE) are presented. The two most critical components of this advanced system for future supersonic transports, the high performance duct burner for thrust augmentation, and the low jet coannular nozzle were studied. Nozzle model tests substantiated the jet noise benefit associated with the unique velocity profile possible with a coannular nozzle system on a VSCE. Additional nozzle model performance tests have established high thrust efficiency levels only at takeoff and supersonic cruise for this nozzle system. An experimental program involving both isolated component and complete engine tests has been conducted for the high performance, low emissions duct burner with good results and large scale testing of these two components is being conducted using a F100 engine as the testbed for simulating the VSCE. Future work includes application of computer programs for supersonic flow fields to coannular nozzle geometries, further experimental testing with the duct burner segment rig, and the use of the Variable Cycle Engine (VCE) Testbed Program for evaluating the VSCE duct burner and coannular nozzle technologies.

Evaluation of the flame propagation within an SI engine using flame imaging and LES

NASA Astrophysics Data System (ADS)

He, Chao; Kuenne, Guido; Yildar, Esra; van Oijen, Jeroen; di Mare, Francesca; Sadiki, Amsini; Ding, Carl-Philipp; Baum, Elias; Peterson, Brian; Böhm, Benjamin; Janicka, Johannes

2017-11-01

This work shows experiments and simulations of the fired operation of a spark ignition engine with port-fuelled injection. The test rig considered is an optically accessible single cylinder engine specifically designed at TU Darmstadt for the detailed investigation of in-cylinder processes and model validation. The engine was operated under lean conditions using iso-octane as a substitute for gasoline. Experiments have been conducted to provide a sound database of the combustion process. A planar flame imaging technique has been applied within the swirl- and tumble-planes to provide statistical information on the combustion process to complement a pressure-based comparison between simulation and experiments. This data is then analysed and used to assess the large eddy simulation performed within this work. For the simulation, the engine code KIVA has been extended by the dynamically thickened flame model combined with chemistry reduction by means of pressure dependent tabulation. Sixty cycles have been simulated to perform a statistical evaluation. Based on a detailed comparison with the experimental data, a systematic study has been conducted to obtain insight into the most crucial modelling uncertainties.

An investigation of the performance of an electronic in-line pump system for diesel engines

NASA Astrophysics Data System (ADS)

Fan, Li-Yun; Zhu, Yuan-Xian; Long, Wu-Qiang; Ma, Xiu-Zhen; Xue, Ying-Ying

2008-12-01

WIT Electronic Fuel System Co., Ltd. has developed a new fuel injector, the Electronic In-line Pump (EIP) system, designed to meet China’s diesel engine emission and fuel economy regulations. It can be used on marine diesel engines and commercial vehicle engines through different EIP systems. A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization. The model was used to predict key injection characteristics under different operating conditions, such as injection pressure, injection rate, and injection duration. To validate these predictions, experimental tests were conducted under the conditions that were modeled. The results were quite encouraging and in agreement with model predictions. Additional experiments were conducted to study the injection characteristics of the EIP system. These results show that injection pressure and injection quantity are insensitive to injection timing variations, this is due to the design of the constant velocity cam profile. Finally, injection quantity and pressure vs. pulse width at different cam speeds are presented, an important injection characteristic for EIP system calibration.

T55-L-712 turbine engine compressor housing refurbishment-plasma spray project

NASA Technical Reports Server (NTRS)

Leissler, George W.; Yuhas, John S.

1988-01-01

A study was conducted to assess the feasibility of reclaiming T55-L-712 turbine engine compressor housings with an 88 wt percent aluminum to 12 wt percent silicon alloy applied by a plasma spray process. Tensile strength testing was conducted on as-sprayed and thermally cycled test specimens which were plasma sprayed with 0.020 to 0.100 in. coating thicknesses. Satisfactory tensile strength values were observed in the as-sprayed tensile specimens. There was essentially no decrease in tensile strength after thermally cycling the tensile specimens. Furthermore, compressor housings were plasma sprayed and thermally cycled in a 150-hr engine test and a 200-hr actual flight test during which the turbine engine was operated at a variety of loads, speeds and torques. The plasma sprayed coating system showed no evidence of degradation or delamination from the compressor housings. As a result of these tests, a procedure was designed and developed for the application of an aluminum-silicon alloy in order to reclaim T55-L-712 turbine engine compressor housings.

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

Design and experimental investigations on six-stroke SI engine using acetylene with water injection.

PubMed

Gupta, Keshav; Suthar, Kishanlal; Jain, Sheetal Kumar; Agarwal, Ghanshyam Das; Nayyar, Ashish

2018-06-02

In the present study, a four-stroke cycle gasoline engine is redesigned and converted into a six-stroke cycle engine and experimental study has been conducted using gasoline and acetylene as fuel with water injection at the end of the recompression stroke. Acetylene has been used as an alternative fuel along with gasoline and performance of the six-stroke spark ignition (SI) engine with these two fuels has been studied separately and compared. Brake power and thermal efficiency are found to be 5.18 and 1.55% higher with acetylene as compared to gasoline in the six-stroke engine. However, thermal efficiency is found to be 45% higher with acetylene in the six-stroke engine as compared to four-stroke SI engine. The CO and HC emissions were found to be reduced by 13.33 and 0.67% respectively with acetylene as compared to gasoline due to better combustion of acetylene. The NO x emission was reduced by 5.65% with acetylene due to lower peak temperature by water injection. The experimental results showed better engine performance and emissions with acetylene as fuel in the six-stroke engine.

The energy efficient engine project

NASA Technical Reports Server (NTRS)

Macioce, L. E.; Schaefer, J. W.; Saunders, N. T.

1980-01-01

The Energy Efficient Engine Project is directed at providing, by 1984, the advanced technologies which could be used for a generation of fuel conservative turbofan engines. The project is conducted through contracts with the General Electric Company and Pratt and Whitney Aircraft. The scope of the entire project and the current status of these efforts are summarized. A description of the preliminary designs of the fully developed engines is included and the potential benefits of these advanced engines, as well as highlights of some of the component technology efforts conducted to date, are discussed.

Invisible Engineers

NASA Astrophysics Data System (ADS)

Ohashi, Hideo

Questionnaire to ask “mention three names of scientists you know” and “three names of engineers you know” was conducted and the answers from 140 adults were analyzed. The results indicated that the image of scientists is represented by Nobel laureates and that of engineers by great inventors like Thomas Edison and industry founders like Soichiro Honda. In order to reveal the image of engineers among young generation, questionnaire was conducted for pupils in middle and high schools. Answers from 1,230 pupils were analyzed and 226 names mentioned as engineers were classified. White votes reached 60%. Engineers who are neither big inventors nor company founders collected less than 1% of named votes. Engineers are astonishingly invisible from young generation. Countermeasures are proposed.

Automotive Stirling engine systems development

NASA Technical Reports Server (NTRS)

Richey, A. E.

1984-01-01

The objective of the Automotive Stirling Engine (ASE) program is to develop a Stirling engine for automotive use that provides a 30 percent improvement in fuel economy relative to a comparable internal-combustion engine while meeting emissions goals. This paper traces the engine systems' development efforts focusing on: (1) a summary of engine system performance for all Mod I engines; (2) the development, program conducted for the upgraded Mod I; and (3) vehicle systems work conducted to enhance vehicle fuel economy. Problems encountered during the upgraded Mod I test program are discussed. The importance of the EPA driving cycle cold-start penalty and the measures taken to minimize that penalty with the Mod II are also addressed.

Alternate Propulsion Subsystem Concepts Tripropellant Comparison Study

NASA Technical Reports Server (NTRS)

Levack, Daniel

1995-01-01

A study was conducted under MSFC contract NAS8-39210 to compare tripropellant and bipropellant engine configurations for the SSTO mission. The objective was to produce an 'apples-to-apples' comparison to isolate the effects of design implementation, designing company, year of design, or technologies included from the basic tripropellant/bipropellant comparison. Consequently, identical technologies were included (e.g., jet pumps) and the same design groundrules and practices were used. Engine power cycles were examined as were turbomachinery/preburner arrangements for each cycle. The bipropellant approach and two tripropellant approaches were separately optimized in terms of operating parameters: exit pressures, mixture ratios, thrust splits, etc. This briefing presents the results of the study including engine weights for both tripropellant and bipropellant engines; dry vehicle weight performance for a range of engine chamber pressures; discusses the basis for the results; examines vehicle performance due to engine cycles and the margin characteristics of various cycles; and identifies technologies with significant payoffs for this application.

Human Resource Development and New Technology in the Automobile Industry: A Case Study of Ford Motor Company's Dearborn Engine Plant. The Development and Utilization of Human Resources in the Context of Technological Change and Industrial Restructuring.

ERIC Educational Resources Information Center

Chen, Kan; And Others

This report centers around a plant-level study of the development and utilization of human resources in the context of technological change and industrial restructuring in the crankshaft production area of Ford Motor Company's Dearborn Engine Plant (DEP). The introductory chapter describes how the study was conducted, provides an introduction to…

Controlling the Didactic Relation: A Case in Process Engineering Education

ERIC Educational Resources Information Center

Jaako, Juha

2014-01-01

A case study was conducted during 1994-2013 on several groups of process engineering students to see what was needed to transform a single course from a teacher-centred to a student-centred learning environment (SCLE). Development work was done incrementally, using Herbart's didactic triangle as a theoretical framework. The effects of the…

Developing a Pre-Engineering Curriculum for 3D Printing Skills for High School Technology Education

ERIC Educational Resources Information Center

Chien, Yu-Hung

2017-01-01

This study developed an integrated-STEM CO[subscript 2] dragster design course using 3D printing technology. After developing a pre-engineering curriculum, we conducted a teaching experiment to assess students' differences in creativity, race forecast accuracy, and learning performance. We compared student performance in both 3D printing and…

Extensive Graded Reading with Engineering Students: Effects and Outcomes

ERIC Educational Resources Information Center

Hagley, Eric

2017-01-01

Extensive graded reading (EGR) was carried out with a cohort of 600 engineering students in a university in northern Japan. Pre-and post-surveys were conducted to discover changes in the general reading habits of students, their attitudes toward the assessment method and how goals changed over the course of study. The first survey was carried out…

Adopting a Strategy for Enhancing Generic Skills in Engineering Education

ERIC Educational Resources Information Center

Krassadaki, Evangelia; Lakiotaki, Kleanthi; Matsatsinis, Nilolaos F.

2014-01-01

It is remarkable how often academic staff discover students' weaknesses in expressing their thoughts in written and oral contexts, and in team working. To examine these weaknesses, a study was conducted in 2009-2010 and 2010-2011 of students taking an engineering course. Students self-reported an initial high level of weakness in both…

Examining the Impact of the Engineering Successful/Unsuccessful Grading (SUG) Program on Student Retention

ERIC Educational Resources Information Center

Novak, Heather; Paguyo, Christina; Siller, Thomas

2016-01-01

In this study, we analyzed the Successful/Unsuccessful Grading (SUG) program, an intervention that was founded at a large public university to support students during their transition into the first year of undergraduate engineering (EG) coursework. To understand how the SUG program impacts student retention of EG majors, we conducted an analysis…

Using Citation Analysis Methods to Assess the Influence of Science, Technology, Engineering, and Mathematics Education Evaluations

ERIC Educational Resources Information Center

Greenseid, Lija O.; Lawrenz, Frances

2011-01-01

This study explores the use of citation analysis methods to assess the influence of program evaluations conducted within the area of science, technology, engineering, and mathematics (STEM) education. Citation analysis is widely used within scientific research communities to measure the relative influence of scientific research enterprises and/or…

Involvement of African-American Girls in Science, Technology, Engineering, and Mathematics (STEM) Education

ERIC Educational Resources Information Center

Nkere, Nsidi

2016-01-01

A qualitative case study was conducted by examining the perceptions of fifth-grade African American girls about their experiences with science, technology, engineering and mathematics (STEM) education and potential for STEM as a future career. As the United States suffers from waning participation across all demographics in STEM and a high level…

Investigation into the cost-effectiveness of using consultants versus in-house staff in providing professional engineering services for Louisiana's Department of Transportation and Development : technical assistance report.

DOT National Transportation Integrated Search

1995-06-01

The objective of the work reported in this document is to: (i) review past studies of the cost-effectiveness of using consultants versus in-house staff in conducting professional engineering services for state Departments of Transportation, (ii) repo...

Radiation effect on rocket engine performance

NASA Technical Reports Server (NTRS)

Chiu, Huei-Huang; Kross, K. W.; Krebsbach, A. N.

1990-01-01

Critical problem areas involving the effect of radiation on the combustion of bipropellants are addressed by formulating a universal scaling law in combination with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and data pertaining to the Variable Thrust Engine (VTE) and the Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low-enthalpy engines, such as the VTE, are vulnerable to a substantial performance setback due to radiative loss, whereas the performance of high-enthalpy engines such as the SSME are hardly affected over a broad range of engine operation. Combustion enhancement by radiative heating of the propellant has a significant impact on propellants with high absorptivity.

Experimental study on distributed optical fiber-based approach monitoring saturation line in levee engineering

NASA Astrophysics Data System (ADS)

Su, Huaizhi; Li, Hao; Kang, Yeyuan; Wen, Zhiping

2018-02-01

Seepage is one of key factors which affect the levee engineering safety. The seepage danger without timely detection and rapid response may likely lead to severe accidents such as seepage failure, slope instability, and even levee break. More than 90 percent of levee break events are caused by the seepage. It is very important for seepage behavior identification to determine accurately saturation line in levee engineering. Furthermore, the location of saturation line has a major impact on slope stability in levee engineering. Considering the structure characteristics and service condition of levee engineering, the distributed optical fiber sensing technology is introduced to implement the real-time observation of saturation line in levee engineering. The distributed optical fiber temperature sensor system (DTS)-based monitoring principle of saturation line in levee engineering is investigated. An experimental platform, which consists of DTS, heating system, water-supply system, auxiliary analysis system and levee model, is designed and constructed. The monitoring experiment of saturation line in levee model is implemented on this platform. According to the experimental results, the numerical relationship between moisture content and thermal conductivity in porous medium is identified. A line heat source-based distributed optical fiber method obtaining the thermal conductivity in porous medium is developed. A DTS-based approach is proposed to monitor the saturation line in levee engineering. The embedment pattern of optical fiber for monitoring saturation line is presented.

An Atomistic-Scale Study for Thermal Conductivity and Thermochemical Compatibility in (DyY)Zr2O7 Combining an Experimental Approach with Theoretical Calculation.

PubMed

Qu, Liu; Choy, Kwang-Leong; Wheatley, Richard

2016-02-18

Ceramic oxides that have high-temperature capabilities can be deposited on the superalloy components in aero engines and diesel engines to advance engine efficiency and reduce fuel consumption. This paper aims to study doping effects of Dy(3+) and Y(3+)on the thermodynamic properties of ZrO2 synthesized via a sol-gel route for a better control of the stoichiometry, combined with molecular dynamics (MD) simulation for the calculation of theoretical properties. The thermal conductivity is investigated by the MD simulation and Clarke's model. This can improve the understanding of the microstructure and thermodynamic properties of (DyY)Zr2O7 (DYZ) at the atomistic level. The phonon-defect scattering and phonon-phonon scattering processes are investigated via the theoretical calculation, which provides an effective way to study thermal transport properties of ionic oxides. The measured and predicted thermal conductivity of DYZ is lower than that of 4 mol % Y2O3 stabilized ZrO2 (4YSZ). It is discovered that DYZ is thermochemically compatible with Al2O3 at 1300 °C, whereas at 1350 °C DYZ reacts with Al2O3 forming a small amount of new phases.

An Atomistic-Scale Study for Thermal Conductivity and Thermochemical Compatibility in (DyY)Zr2O7 Combining an Experimental Approach with Theoretical Calculation

PubMed Central

Qu, Liu; Choy, Kwang-Leong; Wheatley, Richard

2016-01-01

Ceramic oxides that have high-temperature capabilities can be deposited on the superalloy components in aero engines and diesel engines to advance engine efficiency and reduce fuel consumption. This paper aims to study doping effects of Dy3+ and Y3+on the thermodynamic properties of ZrO2 synthesized via a sol-gel route for a better control of the stoichiometry, combined with molecular dynamics (MD) simulation for the calculation of theoretical properties. The thermal conductivity is investigated by the MD simulation and Clarke’s model. This can improve the understanding of the microstructure and thermodynamic properties of (DyY)Zr2O7 (DYZ) at the atomistic level. The phonon-defect scattering and phonon-phonon scattering processes are investigated via the theoretical calculation, which provides an effective way to study thermal transport properties of ionic oxides. The measured and predicted thermal conductivity of DYZ is lower than that of 4 mol % Y2O3 stabilized ZrO2 (4YSZ). It is discovered that DYZ is thermochemically compatible with Al2O3 at 1300 °C, whereas at 1350 °C DYZ reacts with Al2O3 forming a small amount of new phases. PMID:26888438

Molecular engineering and measurements to test hypothesized mechanisms in single molecule conductance switching.

PubMed

Moore, Amanda M; Dameron, Arrelaine A; Mantooth, Brent A; Smith, Rachel K; Fuchs, Daniel J; Ciszek, Jacob W; Maya, Francisco; Yao, Yuxing; Tour, James M; Weiss, Paul S

2006-02-15

Six customized phenylene-ethynylene-based oligomers have been studied for their electronic properties using scanning tunneling microscopy to test hypothesized mechanisms of stochastic conductance switching. Previously suggested mechanisms include functional group reduction, functional group rotation, backbone ring rotation, neighboring molecule interactions, bond fluctuations, and hybridization changes. Here, we test these hypotheses experimentally by varying the molecular designs of the switches; the ability of the molecules to switch via each hypothetical mechanism is selectively engineered into or out of each molecule. We conclude that hybridization changes at the molecule-surface interface are responsible for the switching we observe.

Emissions from in-use lawn-mowers in Australia

NASA Astrophysics Data System (ADS)

Priest, M. W.; Williams, D. J.; Bridgman, H. A.

Concern over the levels of pollutants emitted from small engines has led to recent legislation in the United States that regulates exhaust emissions from lawn and garden equipment. Particular attention has focused on the high levels of hydrocarbons emitted by these engines. The present study establishes emission factors for lawn-mowers in use in Australia. The estimates were calculated on the basis of a series of controlled emission tests conducted on commonly used lawn-mowers. Ten two-stroke and six four-stroke lawn-mower engines were operated under simulated power requirements while fuel usage and gas emissions were monitored. Fuel consumption rates from the tests were compared to those ascertained under actual mowing conditions in field tests conducted on 19 two-stroke and ten four-stroke lawn-mowers. Basic emission factors were established for CO, CO 2, CH 4, NMHC and NO x, and combined with data on machine population and annual usage collected in a survey of lawn care practices and lawn-mower usage conducted in the Newcastle area. When compared to transport sources in the Newcastle study region, lawn-mowers contribute 5.2 and 11.6% of CO and NMHC emissions, respectively.

Advancement of proprotor technology. Task 1: Design study summary. [aerodynamic concept of minimum size tilt proprotor research aircraft

NASA Technical Reports Server (NTRS)

1969-01-01

A tilt-proprotor proof-of-concept aircraft design study has been conducted. The results are presented. The ojective of the contract is to advance the state of proprotor technology through design studies and full-scale wind-tunnel tests. The specific objective is to conduct preliminary design studies to define a minimum-size tilt-proprotor research aircraft that can perform proof-of-concept flight research. The aircraft that results from these studies is a twin-engine, high-wing aircraft with 25-foot, three-bladed tilt proprotors mounted on pylons at the wingtips. Each pylon houses a Pratt and Whitney PT6C-40 engine with a takeoff rating of 1150 horsepower. Empty weight is estimated at 6876 pounds. The normal gross weight is 9500 pounds, and the maximum gross weight is 12,400 pounds.

Thermal Response Turbine Shroud.

DTIC Science & Technology

1979-11-01

AD-AO82 754. GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP F/G 21/5 THERMAL RESPONSE TURBINE SHROUO.(UI NOV 79 C N GAY F33615-7B-C-2071...SUPPLEMENTARY NOTES IS. IEV WORDS (C..tIam. ON guinea 80410 Itf08M 8". 1~0 &VU~ b lma n-M-) Clearance Shroud Clearance Control Turbine Shroud engine / aircrafte ...compressor Active Clearance Control Systems (ACC) de-signed for aircraft gas turbine engine applications. The study vas conducted by personnel of the

Thermal conductivity model for powdered materials under vacuum based on experimental studies

NASA Astrophysics Data System (ADS)

Sakatani, N.; Ogawa, K.; Iijima, Y.; Arakawa, M.; Honda, R.; Tanaka, S.

2017-01-01

The thermal conductivity of powdered media is characteristically very low in vacuum, and is effectively dependent on many parameters of their constituent particles and packing structure. Understanding of the heat transfer mechanism within powder layers in vacuum and theoretical modeling of their thermal conductivity are of great importance for several scientific and engineering problems. In this paper, we report the results of systematic thermal conductivity measurements of powdered media of varied particle size, porosity, and temperature under vacuum using glass beads as a model material. Based on the obtained experimental data, we investigated the heat transfer mechanism in powdered media in detail, and constructed a new theoretical thermal conductivity model for the vacuum condition. This model enables an absolute thermal conductivity to be calculated for a powder with the input of a set of powder parameters including particle size, porosity, temperature, and compressional stress or gravity, and vice versa. Our model is expected to be a competent tool for several scientific and engineering fields of study related to powders, such as the thermal infrared observation of air-less planetary bodies, thermal evolution of planetesimals, and performance of thermal insulators and heat storage powders.

Development Status of the NASA MC-1 (Fastrac) Engine

NASA Technical Reports Server (NTRS)

Ballard, Richard O.; Olive, Tim; Turner, James E. (Technical Monitor)

2000-01-01

The MC-1 (formerly known as the Fastrac 60K) Engine is being developed for the X-34 technology demonstrator vehicle. It is a pump-fed liquid rocket engine with fixed thrust operating at one rated power level of 60,000 lbf vacuum thrust using a 15:1 area ratio nozzle (slightly higher for the 30:1 flight nozzle). Engine system development testing of the MC-1 has been ongoing since 24 Oct 1998. To date, 48 tests have been conducted on three engines using three separate test stands. This paper will provide some details of the engine, the tests conducted, and the lessons learned to date.

Electrospun conductive nanofibrous scaffolds for engineering cardiac tissue and 3D bioactuators.

PubMed

Wang, Ling; Wu, Yaobin; Hu, Tianli; Guo, Baolin; Ma, Peter X

2017-09-01

Mimicking the nanofibrous structure similar to extracellular matrix and conductivity for electrical propagation of native myocardium would be highly beneficial for cardiac tissue engineering and cardiomyocytes-based bioactuators. Herein, we developed conductive nanofibrous sheets with electrical conductivity and nanofibrous structure composed of poly(l-lactic acid) (PLA) blending with polyaniline (PANI) for cardiac tissue engineering and cardiomyocytes-based 3D bioactuators. Incorporating of varying contents of PANI from 0wt% to 3wt% into the PLA polymer, the electrospun nanofibrous sheets showed enhanced conductivity while maintaining the same fiber diameter. These PLA/PANI conductive nanofibrous sheets exhibited good cell viability and promoting effect on differentiation of H9c2 cardiomyoblasts in terms of maturation index and fusion index. Moreover, PLA/PANI nanofibrous sheets enhanced the cell-cell interaction, maturation and spontaneous beating of primary cardiomyocytes. Furthermore, the cardiomyocytes-laden PLA/PANI conductive nanofibrous sheets can form 3D bioactuators with tubular and folding shapes, and spontaneously beat with much higher frequency and displacement than that on cardiomyocytes-laden PLA nanofibrous sheets. Therefore, these PLA/PANI conductive nanofibrous sheets with conductivity and extracellular matrix like nanostructure demonstrated promising potential in cardiac tissue engineering and cardiomyocytes-based 3D bioactuators. Cardiomyocytes-based bioactuators have been paid more attention due to their spontaneous motion by integrating cardiomyocytes into polymer structures, but developing suitable scaffolds for bioactuators remains challenging. Electrospun nanofibrous scaffolds have been widely used in cardiac tissue engineering because they can mimic the extracellular matrix of myocardium. Developing conductive nanofibrous scaffolds by electrospinning would be beneficial for cardiomyocytes-based bioactuators, but such scaffolds have been rarely reported. This work presented a conductive nanofibrous sheet based on polylactide and polyaniline via electrospinning with tunable conductivity. These conductive nanofibrous sheets performed the ability to enhance cardiomyocytes maturation and spontaneous beating, and further formed cardiomyocytes-based 3D bioactuators with tubular and folding shapes, which indicated their great potential in cardiac tissue engineering and bioactuators applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Conducting Rock Mass Rating for tunnel construction on Mars

NASA Astrophysics Data System (ADS)

Beemer, Heidi D.; Worrells, D. Scott

2017-10-01

Mars analogue missions provide researchers, scientists, and engineers the opportunity to establish protocols prior to sending human explorers to another planet. This paper investigated the complexity of a team of simulation astronauts conducting a Rock Mass Rating task during Analogue Mars missions. This study was conducted at the Mars Desert Research Station in Hanksville, UT, during field season 2015/2016 and with crews 167,168, and 169. During the experiment, three-person teams completed a Rock Mass Rating task during a three hour Extra Vehicular Activity on day six of their two-week simulation mission. This geological test is used during design and construction of excavations in rock on Earth. On Mars, this test could be conducted by astronauts to determine suitable rock layers for tunnel construction which would provide explorers a permanent habitat and radiation shielding while living for long periods of time on the surface. The Rock Mass Rating system derives quantitative data for engineering designs that can easily be communicated between engineers and geologists. Conclusions from this research demonstrated that it is feasible for astronauts to conduct the Rock Mass Rating task in a Mars simulated environment. However, it was also concluded that Rock Mass Rating task orientation and training will be required to ensure that accurate results are obtained.

`Human nature': Chemical engineering students' ideas about human relationships with the natural world

NASA Astrophysics Data System (ADS)

Goldman, Daphne; Ben-Zvi Assaraf, Orit; Shemesh, Julia

2014-05-01

While importance of environmental ethics, as a component of sustainable development, in preparing engineers is widely acknowledged, little research has addressed chemical engineers' environmental concerns. This study aimed to address this void by exploring chemical engineering students' values regarding human-nature relationships. The study was conducted with 247 3rd-4th year chemical engineering students in Israeli Universities. It employed the New Ecological Paradigm (NEP)-questionnaire to which students added written explanations. Quantitative analysis of NEP-scale results shows that the students demonstrated moderately ecocentric orientation. Explanations to the NEP-items reveal diverse, ambivalent ideas regarding the notions embodied in the NEP, strong scientific orientation and reliance on technology for addressing environmental challenges. Endorsing sustainability implies that today's engineers be equipped with an ecological perspective. The capacity of Higher Education to enable engineers to develop dispositions about human-nature interrelationships requires adaptation of curricula towards multidisciplinary, integrative learning addressing social-political-economic-ethical perspectives, and implementing critical-thinking within the socio-scientific issues pedagogical approach.

Partnering with Engineers to Identify and Empirically Evaluate Delays in Magnetic Resonance Imaging Laying the Foundations for Quality Improvement and System-based Practice in Radiology.

PubMed

Brandon, Catherine J; Holody, Michael; Inch, Geoffrey; Kabcenell, Michael; Schowalter, Diane; Mullan, Patricia B

2012-01-01

The aim of this study was to evaluate the feasibility of partnering with engineering students and critically examining the merit of the problem identification and analyses students generated in identifying sources impeding effective turnaround in a large university department of diagnostic radiology. Turnaround involves the time and activities beginning when a patient enters the magnetic resonance scanner room until the patient leaves, minus the time the scanner is conducting the protocol. A prospective observational study was conducted, in which four senior undergraduate industrial and operations engineering students interviewed magnetic resonance staff members and observed all shifts. On the basis of 150 hours of observation, the engineering students identified 11 process steps (eg, changing coils). They charted machine use for all shifts, providing a breakdown of turnaround time between appropriate process and non-value-added time. To evaluate the processes occurring in the scanning room, the students used a work-sampling schedule in which a beeper sounded 2.5 times per hour, signaling the technologist to identify which of 11 process steps was occurring. This generated 2147 random observations over a 3-week period. The breakdown of machine use over 105 individual studies showed that non-value-added time accounted for 62% of turnaround time. Analysis of 2147 random samples of work showed that scanners were empty and waiting for patients 15% of the total time. Analyses showed that poor communication delayed the arrival of patients and that no one had responsibility for communicating when scanning was done. Engineering students used rigorous study design and sampling methods to conduct interviews and observations. This led to data-driven definition of problems and potential solutions to guide systems-based improvement. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Charge It! Translating Electric Vehicle Research Results to Engage 7th and 8th Grade Girls

NASA Astrophysics Data System (ADS)

Egbue, Ona; Long, Suzanna; Ng, Ean-Harn

2015-10-01

Despite attempts to generate interest in science and technology careers, US students continue to show reduced interest in science, technology, engineering and mathematics (STEM) majors at the collegiate level. If girls are not engaged in STEM learning by the middle school level, studies show that they are even less likely to choose a science- or engineering-related major. This article presents results from a workshop for 7th and 8th grade girls designed to promote knowledge building in the area of sustainability and alternative energy use in transportation and to stimulate greater interest in STEM subjects. The workshop based on research conducted at University X focused on basic concepts of electric vehicles and electric vehicles' batteries. Tests were conducted to evaluate the students' knowledge and perceptions of electric vehicles and to determine the impact of the workshop. Early exposure to meaningful engineering experiences for these young girls may boost interest and the eventual pursuit of engineering and technology education paths.

Cognitive diversity in undergraduate engineering: Dyslexia

NASA Astrophysics Data System (ADS)

Fitzpatrick, Velvet R.

In the United States, institutions have established multiple programs and initiatives aimed at increasing the diversity of both faculty and students in engineering as means to produce a workforce that will better serve society. However, there are two major problems in addressing engineering student diversity. First, the engineering education research community has paid little attention to date as to how engineering education research characterizes diversity in its broadest sense. Second, research on persons with disabilities in undergraduates engineering, a population of interests within diversity, is minimal. Available disability studies tend to be skewed toward physical disabilities, leading to a neglect of cognitive differences such as learning disabilities (LD). In addition, disability research questions and study designs are inherently steeped in ability bias. The purpose of this dissertation is to explore the meaning of ability for students with dyslexia while in undergraduate engineering and establish the significance of cognitive diversity, focusing on LD and more specifically dyslexia, in undergraduate engineering education and answer the following research question: How do undergraduate engineering students with dyslexia experience ability while pursuing and persisting in engineering? The motivation was to lay the groundwork for future engineering education studies on undergraduate students with LD in general but dyslexia in specific. The first goal was to conduct a critical literature review pertaining to the academic strengths of undergraduate students with LD, specifically, dyslexia and the second goal was to describe how undergraduate engineering students with dyslexia experience ability. The intent was not to redefine dyslexia or disability. The intent is to provide an inclusive account of dyslexia, weakness and strengths, within the field of engineering education. This study was conducted from a qualitative inquiry approach, within the social constructivism paradigm, and utilized purposive sampling to identify appropriate participants. The thematic analysis methodological framework was used to portray a rich, complex description of experiences in which undergraduate engineering students with dyslexia constructed meaning around ability while pursuing and persisting in engineering. Eight students participated and semi-structured interviews were the data source. The findings are presented in three parts. First, significant findings that were also salient amongst the general undergraduate engineering student populations are presented. This is done to make a clear demarcation from those significant findings found to be unique to undergraduate engineering students with dyslexia presented in the themes: relationships, early exposure to engineering, and securing an internship or co-op position. Second, the four themes that developed from the analysis will were discussed: alignment, dissociation, ideal education environments, and time. Third, additional findings for further investigation were proposed: the role of remediation practices, the representation of dyslexia in media, gender differences in extracurricular activities that constructed different meanings of ability, the prevalence of co-occurring LD amongst the participants, and the visualization of science, engineering, mathematics concepts. The study is closed with a discussion; findings are discussed with respect to relevant research in the conclusion.

Enhancing Systems Engineering Education Through Case Study Writing

NASA Technical Reports Server (NTRS)

Stevens, Jennifer Stenger

2016-01-01

Developing and refining methods for teaching systems engineering is part of Systems Engineering grand challenges and agenda for research in the SE research community. Retention of systems engineering knowledge is a growing concern in the United States as the baby boom generation continues to retire and the faster pace of technology development does not allow for younger generations to gain experiential knowledge through years of practice. Government agencies, including the National Aeronautics and Space Administration (NASA), develop their own curricula and SE leadership development programs to "grow their own" systems engineers. Marshall Space Flight Center (MSFC) conducts its own Center-focused Marshall Systems Engineering Leadership Development Program (MSELDP), a competitive program consisting of coursework, a guest lecture series, and a rotational assignment into an unfamiliar organization engaged in systems engineering. Independently, MSFC developed two courses to address knowledge retention and sharing concerns: Real World Marshall Mission Success course and its Case Study Writers Workshop and Writers Experience. Teaching case study writing and leading students through a hands-on experience at writing a case study on an SE topic can enhance SE training and has the potential to accelerate the transfer of experiential knowledge. This paper is an overview of the pilot experiences with teaching case study writing, its application in case study-based learning, and identifies potential areas of research and application for case study writing in systems engineering education.

Determination of the availability of appropriate aged flight rocket motors. [captive tests to determine case bond separation and grain bore cracking

NASA Technical Reports Server (NTRS)

Martin, P. J.

1974-01-01

A program to identify surplus solid rocket propellant engines which would be available for a program of functional integrity testing was conducted. The engines are classified as: (1) upper stage and apogee engines, (2) sounding rocket and launch vehicle engines, and (3) jato, sled, and tactical engines. Nearly all the engines were available because their age exceeds the warranted shelf life. The preference for testing included tests at nominal flight conditions, at design limits, and to establish margin limits. The principal failure modes of interest were case bond separation and grain bore cracking. Data concerning the identification and characteristics of each engine are tabulated. Methods for conducting the tests are described.

Advanced Risk Reduction Tool (ARRT) Special Case Study Report: Science and Engineering Technical Assessments (SETA) Program

NASA Technical Reports Server (NTRS)

Kirsch, Paul J.; Hayes, Jane; Zelinski, Lillian

2000-01-01

This special case study report presents the Science and Engineering Technical Assessments (SETA) team's findings for exploring the correlation between the underlying models of Advanced Risk Reduction Tool (ARRT) relative to how it identifies, estimates, and integrates Independent Verification & Validation (IV&V) activities. The special case study was conducted under the provisions of SETA Contract Task Order (CTO) 15 and the approved technical approach documented in the CTO-15 Modification #1 Task Project Plan.

Ice Particle Impacts on a Flat Plate

NASA Technical Reports Server (NTRS)

Vargas, Mario; Ruggeri, Charles; Struk, Peter M.; Pereira, Mike; Revilock, Duane; Kreeger, Richard E.

2015-01-01

An experimental study was conducted at the Ballistic Laboratory of NASA Glenn Research Center to study the impact of ice particles on a stationary flat surface target set at 45 degrees with respect to the direction of motion of the impinging particle (Figure 1). The experiment is part of NASA efforts to study the physics involved in engine power-loss events due to ice-crystal ingestion and ice accretion formation inside engines. These events can occur when aircraft encounter high-altitude convective weather.

Dye Study in Greenwich Conn. Harbor April 3-7, 2017

EPA Pesticide Factsheets

Scientists and engineers from CTDABA, USEPA's New England Regional Laboratory, together with staff from the USFDA Shellfish Sanitation Program will begin conducting a hydrographic dye dilution study beginning April 3rd.

Stirling Laboratory Research Engine: Preprototype configuration report

NASA Technical Reports Server (NTRS)

Hoehn, F. W.

1982-01-01

The concept of a simple Stirling research engine that could be used by industrial, university, and government laboratories was studied. The conceptual and final designs, hardware fabrication and the experimental validation of a preprototype stirling laboratory research engine (SLRE) were completed. Also completed was a task to identify the potential markets for research engines of this type. An analytical effort was conducted to provide a stirling cycle computer model. The versatile engine is a horizontally opposed, two piston, single acting stirling engine with a split crankshaft drive mechanism; special instrumentation is installed at all component interfaces. Results of a thermodynamic energy balance for the system are reported. Also included are the engine performance results obtained over a range of speeds, working pressures, phase angles and gas temperatures. The potential for a stirling research engine to support the laboratory requirements of educators and researchers was demonstrated.

Newport Pell Bridge traffic and revenue study

DOT National Transportation Integrated Search

2010-01-12

Jacobs Engineering conducted a traffic and toll revenue study for the Claiborne Pell Newport Bridge : (Newport Pell Bridge or Pell Bridge) upon the request of the Rhode Island Turnpike and Bridge : Authority (RITBA). This study is being c...

A study of accidents involving highway bridges.

DOT National Transportation Integrated Search

1971-01-01

Accident reports, field evaluations, state police and highway engineer questionnaire replies, and other data sources were used to conduct a general study of accidents involving highway bridges in Virginia. The bridges included in the study were divid...

NASA’s Stennis Space Center Conducts RS-25 Engine Test

NASA Image and Video Library

2017-03-24

On March 23, NASA conducted a test of an RS-25 engine at the agency’s Stennis Space Center in Bay St. Louis, Mississippi. Four RS-25’s will help power NASA’s Space Launch System (SLS) rocket to space. During this test, engineers evaluated the engine’s new controller or “brain”, which communicates with the SLS vehicle. Once test data is certified, the engine controller will be removed and installed on one of the four flight engines that will help power the first integrated flight of SLS and the Orion spacecraft.

Developments in REDES: The rocket engine design expert system

NASA Technical Reports Server (NTRS)

Davidian, Kenneth O.

1990-01-01

The Rocket Engine Design Expert System (REDES) is being developed at the NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP, a nozzle design program named RAO, a regenerative cooling channel performance evaluation code named RTE, and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES is built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

Developments in REDES: The Rocket Engine Design Expert System

NASA Technical Reports Server (NTRS)

Davidian, Kenneth O.

1990-01-01

The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

Recent Advances in LOX / LH2 Propulsion System for Reusable Vehicle Testing

NASA Astrophysics Data System (ADS)

Tokudome, Shinichiro; Naruo, Yoshihiro; Yagishita, Tsuyoshi; Nonaka, Satoshi; Shida, Maki; Mori, Hatsuo; Nakamura, Takeshi

The third-generation vehicle RVT#3 equipped with a pressure-fed engine, which had upgraded in terms of durability enhancement and a LH2 tank of composite material, successfully performed in repeated flight operation tests; and the vehicle reached its maximum flying altitude of 42m in October 2003. The next step for demonstrating entire sequence of full-scale operation is to put a turbopump-fed system into propulsion system. From a result of primary system analysis, we decided to build an expander-cycle engine by diverting a pair of turbopumps, which had built for another research program, to the present study. A combustion chamber with long cylindrical portion adapted to the engine cycle was also newly made. Two captive firing tests have been conducted with two different thrust control methods, following the component tests of combustor and turbopumps separately conducted. A considerable technical issues recognized in the tests were the robustness enhancement of shaft seal design, the adjustment of shaft stiffness, and start-up operation adapted to the specific engine system. Experimental study of GOX/GH2 RCS thrusters have also been started as a part of a conceptual study of the integration of the propulsion system associated with simplification and reliability improvement of the vehicle system.

Designing Worked Examples in Statics to Promote an Expert Stance: Working THRU vs. Working OUT

ERIC Educational Resources Information Center

Calfee, Robert; Stahovich, Thomas

2011-01-01

The purpose of this study was to examine the performance patterns of freshman engineering students as they completed a tutorial on freebody problems that employed a computer-based pen (CBP) to provide feedback and direct learning. A secondary analysis was conducted on detailed performance data for 16 participants from a freshman Engineering course…

Insights from Industry: A Quantitative Analysis of Engineers' Perceptions of Empathy and Care within Their Practice

ERIC Educational Resources Information Center

Hess, Justin L.; Strobel, Johannes; Pan, Rui; Wachter Morris, Carrie A.

2017-01-01

This study focuses on two seldom-investigated skills or dispositions aligned with engineering habits of mind--empathy and care. In order to conduct quantitative research, we designed, explored the underlying structure of, validated, and tested the reliability of the Empathy and Care Questionnaire (ECQ), a new psychometric instrument. In the second…

A Case Study of an Experiment Using Streaming of Lectures in Teaching Engineering Mathematics

ERIC Educational Resources Information Center

Fredriksen, Helge

2015-01-01

To support the possibility of taking an online engineering degree programme, Narvik University College has chosen to facilitate a streaming service of all lectures conducted by the college. At the Bodø college campus, in the academic year of 2012/2013, these online lectures were used as a central component in a didactic innovation project. The aim…

A Curricular Analysis of Undergraduate Technology & Engineering Teacher Preparation Programs in the United States

ERIC Educational Resources Information Center

Litowitz, Len S.

2014-01-01

Technology & engineering teacher preparation programs at colleges and universities in the United States have been in a state of decline since the 1970's. In the fall of 2013 a study was conducted to compare the required curricula of the 24 undergraduate programs that maintain enrollment of 20 students or more in order to determine what a…

Evaluating the Competency Mismatch between Master of Engineering Graduates and Industry Needs in China

ERIC Educational Resources Information Center

Peng, Lijun; Zhang, Shulin; Gu, Jibao

2016-01-01

This study investigates the mismatch between the educational attainment of a graduate with a Master of Engineering (MEng) degree and the industry needs in China. A competency list for MEng graduates from the perspective of industry needs was constructed. And a survey was conducted among MEng graduate students, alumni, and employers to assess the…

Engineering Your Job Search: A Job-Finding Resource for Engineering Professionals.

ERIC Educational Resources Information Center

1995

This guide, which is intended for engineering professionals, explains how to use up-to-date job search techniques to design and conduct an effective job hunt. The first 11 chapters discuss the following steps in searching for a job: handling a job loss; managing time and financial resources while conducting a full-time job search; using objective…

Elementary Students' Learning of Materials Science Practices Through Instruction Based on Engineering Design Tasks

NASA Astrophysics Data System (ADS)

Wendell, Kristen Bethke; Lee, Hee-Sun

2010-12-01

Materials science, which entails the practices of selecting, testing, and characterizing materials, is an important discipline within the study of matter. This paper examines how third grade students' materials science performance changes over the course of instruction based on an engineering design challenge. We conducted a case study of nine students who participated in engineering design-based science instruction with the goal of constructing a stable, quiet, thermally comfortable model house. The learning outcome of materials science practices was assessed by clinical interviews conducted before and after the instruction, and the learning process was assessed by students' workbooks completed during the instruction. The interviews included two materials selection tasks for designing a sturdy stepstool and an insulated pet habitat. Results indicate that: (1) students significantly improved on both materials selection tasks, (2) their gains were significantly positively associated with the degree of completion of their workbooks, and (3) students who were highly engaged with the workbook's reflective record-keeping tasks showed the greatest improvement on the interviews. These findings suggest the important role workbooks can play in facilitating elementary students' learning of science through authentic activity such as engineering design.

Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

PubMed

Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

2011-04-01

Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed. Copyright © 2011 John Wiley & Sons, Ltd.

Analysis of interior noise ground and flight test data for advanced turboprop aircraft applications

NASA Technical Reports Server (NTRS)

Simpson, M. A.; Tran, B. N.

1991-01-01

Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight tests with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

Analysis of interior noise ground and flight test data for advanced turboprop aircraft applications

NASA Astrophysics Data System (ADS)

Simpson, M. A.; Tran, B. N.

1991-08-01

Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight tests with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

A case study of the knowledge transfer practices from the perspectives of highly experienced engineers in the aerospace industry

NASA Astrophysics Data System (ADS)

Martin, Deloris

Purpose. The purpose of this study was to describe the existing knowledge transfer practices in selected aerospace companies as perceived by highly experienced engineers retiring from the company. Specifically it was designed to investigate and describe (a) the processes and procedures used to transfer knowledge, (b) the systems that encourage knowledge transfer, (c) the impact of management actions on knowledge transfer, and (d) constraining factors that might impede knowledge transfer. Methodology. A descriptive case study was the methodology applied in this study. Qualitative data were gathered from highly experienced engineers from 3 large aerospace companies in Southern California. A semistructured interview was conducted face-to-face with each participant in a private or semiprivate, non-workplace setting to obtain each engineer's perspectives on his or her company's current knowledge transfer practices. Findings. The participants in this study preferred to transfer knowledge using face-to-face methods, one-on-one, through actual troubleshooting and problem-solving scenarios. Managers in these aerospace companies were observed as having knowledge transfer as a low priority; they tend not to promote knowledge transfer among their employees. While mentoring is the most common knowledge transfer system these companies offer, it is not the preferred method of knowledge transfer among the highly experienced engineers. Job security and schedule pressures are the top constraints that impede knowledge transfer between the highly experienced engineers and their coworkers. Conclusions. The study data support the conclusion that the highly experienced engineers in the study's aerospace companies would more likely transfer their knowledge to those remaining in the industry if the transfer could occur face-to-face with management support and acknowledgement of their expertise and if their job security is not threatened. The study also supports the conclusion that managers should be responsible for the leadership in developing a knowledge-sharing culture and rewarding those who do share. Recommendations. It is recommended that a quantitative study of highly experienced engineers in aerospace be conducted to determine the degree to which knowledge-sharing methods, processes, and procedures may be effective in capturing their knowledge. It is also recommended that a replication of this study be undertaken to include the perspectives of first-line managers on developing a knowledge-sharing culture for the aerospace industry.

Improving System Engineering Excellence at NASA's Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Takada, Pamela Wallace; Newton, Steve; Gholston, Sampson; Thomas, Dale (Technical Monitor)

2001-01-01

NASA's Marshall Space Flight Center (MSFC) management feels that sound system engineering practices are essential for successful project management, NASA studies have concluded that recent project failures could be attributed in part to inadequate systems engineering. A recent survey of MSFC project managers and system engineers' resulted in the recognition of a need for training in Systems Engineering Practices, particularly as they relate to MSFC projects. In response to this survey, an internal pilot short-course was developed to reinforce accepted practices for system engineering at MSFC. The desire of the MSFC management is to begin with in-house training and offer additional educational opportunities to reinforce sound system engineering principles to the more than 800 professionals who are involved with system engineering and project management. A Systems Engineering Development Plan (SEDP) has been developed to address the longer-term systems engineering development needs of MSFC. This paper describes the survey conducted and the training course that was developed in response to that survey.

History and Benefits of Engine Level Testing Throughout the Space Shuttle Main Engine Program

NASA Technical Reports Server (NTRS)

VanHooser, Katherine; Kan, Kenneth; Maddux, Lewis; Runkle, Everett

2010-01-01

Rocket engine testing is important throughout a program s life and is essential to the overall success of the program. Space Shuttle Main Engine (SSME) testing can be divided into three phases: development, certification, and operational. Development tests are conducted on the basic design and are used to develop safe start and shutdown transients and to demonstrate mainstage operation. This phase helps form the foundation of the program, demands navigation of a very steep learning curve, and yields results that shape the final engine design. Certification testing involves multiple engine samples and more aggressive test profiles that explore the boundaries of the engine to vehicle interface requirements. The hardware being tested may have evolved slightly from that in the development phase. Operational testing is conducted with mature hardware and includes acceptance testing of flight assets, resolving anomalies that occur in flight, continuing to expand the performance envelope, and implementing design upgrades. This paper will examine these phases of testing and their importance to the SSME program. Examples of tests conducted in each phase will also be presented.

Becoming an engineer: Doctoral women's perspectives on identity and learning in the culture of engineering

NASA Astrophysics Data System (ADS)

Wood, Shaunda L.

Women face many obstacles in their academic careers but there is a gap in the research with regards to their perceptions of science and engineering education and how non/participation in the culture of engineering affects their identities. Moreover, little research has been conducted with female Ph.D. students especially with regard to the reasons they have continued their studies, and their level of satisfaction with their career and lives. This study was guided by the sociocultural approach and theories of learning and identity. Methodologically, the design adopted is a naturalistic qualitative inquiry using two open-ended interviews with participant verification after the first interview. The life history narratives (Mishler, 1999) obtained from the seven doctoral electrical and mechanical women engineers, at various stages in their programs, were the primary source of data. By examining the path of becoming a doctoral woman engineer, this study makes the educational experiences of women intelligible to the general public as well as policy makers. It gives voice to the women engineers whose perspectives are rarely heard in academic settings or mainstream society. The findings of the study lend insight to the importance and necessity of more inclusive engineering education, incorporating not only women's studies courses into the curriculum but anti-racism education as well as including the perspective of 'Other' people of difference. Moreover, multi-perspective approaches to increasing enrolment and retention of women in engineering were more effective and in keeping with addressing notions of 'difference' in engineering populations.

Thick thermal barrier coatings for diesel components

NASA Technical Reports Server (NTRS)

Yonushonis, T. M.

1991-01-01

An engineered thick thermal barrier coating consisting of multiple layers of zirconia and CoCrAlY with a zirconia top layer and having a system thermal conductance less than 410 w/m(exp 2)K exceeded the 100 hour engine durability goals set forth in this program. The thermal barrier coatings were intact at the test conclusion. Back to back single cylinder research engine tests were conducted with watercooled, metal hardware and oil-cooled, thermal barrier coating insulated hardware to determine apparent heat release and fuel economy. Apparent heat release data revealed that the insulated engine had a shorter ignition delay and a longer combustion duration than the metal engine. The insulated engine fuel economy was approximately two percent worse on average for this series of tests. There was no attempt to optimize engine efficiency of the insulated engine by modifying the engine timing, coating, or other techniques.

Systems engineering real estate development projects

NASA Astrophysics Data System (ADS)

Gusakova, Elena; Titarenko, Boris; Stepanov, Vitaliy

2017-10-01

In recent years, real estate development has accumulated a wealth of experience in implementing major projects, which requires comprehension and systematization. The scientific instrument of system engineering is studied in the article and is substantively interpreted with reference to real estate development projects. The most perspective approaches and models are substantiated, allowing strategically to plan the life cycle of the project as a whole, and also to solve the engineering butt problems of the project. The relevance of further scientific studies of regularities and specifics of the life cycle of real estate development projects conducted at the Moscow State University of Economics and Management at the ISTA department is shown.

Preliminary Flight Results of a Fly-by-throttle Emergency Flight Control System on an F-15 Airplane

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. Gordon; Wells, Edward A.

1993-01-01

A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies were followed by flight tests. The principles of throttles only control, the F-15 airplane, the augmented system, and the flight results including actual landings with throttles-only control are discussed.

[Research Conducted at the Institute for Computer Applications in Science and Engineering

NASA Technical Reports Server (NTRS)

1997-01-01

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, fluid mechanics, and computer science during the period 1 Oct. 1996 - 31 Mar. 1997.

Ecological Feasibility Studies in Restoration Decision Making

NASA Astrophysics Data System (ADS)

Hopfensperger, Kristine N.; Engelhardt, Katharina A. M.; Seagle, Steven W.

2007-06-01

The restoration of degraded systems is essential for maintaining the provision of valuable ecosystem services, including the maintenance of aesthetic values. However, restoration projects often fail to reach desired goals for a variety of ecologic, financial, and social reasons. Feasibility studies that evaluate whether a restoration effort should even be attempted can enhance restoration success by highlighting potential pitfalls and gaps in knowledge before the design phase of a restoration. Feasibility studies also can bring stakeholders together before a restoration project is designed to discuss potential disagreements. For these reasons, a feasibility study was conducted to evaluate the efficacy of restoring a tidal freshwater marsh in the Potomac River near Alexandria, Virginia. The study focused on science rather than engineering questions, and thus differed in approach from other feasibility studies that are mostly engineering driven. The authors report the framework they used to conduct a feasibility study to inform other potential restoration projects with similar goals. The seven steps of the framework encompass (1) initiation of a feasibility study, (2) compilation of existing data, (3) collection of current site information, (4) examination of case studies, (5) synthesis of information in a handbook, (6) meeting with selected stakeholders, and (7) evaluation of meeting outcomes. By conducting a feasibility study using the seven-step framework, the authors set the stage for conducting future compliance studies and enhancing the chance of a successful restoration.

Ecosystem engineering effects on species diversity across ecosystems: a meta-analysis.

PubMed

Romero, Gustavo Q; Gonçalves-Souza, Thiago; Vieira, Camila; Koricheva, Julia

2015-08-01

Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community. The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to a 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in the tropics than at higher latitudes, likely because new or modified habitats provided by engineers in the tropics may help minimize competition and predation pressures on resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rocky shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Ecosystem engineers that create new habitats or microhabitats had stronger effects than those that modify habitats or cause bioturbation. Invertebrate engineers and those with lower engineering persistence (<1 year) affected species richness more than vertebrate engineers which persisted for >1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

Manual of Transit and Traffic Studies

DOT National Transportation Integrated Search

1947-01-01

This first edition of the "Manual of Transit and Traffic Studies" has been designed to assist transit companies and traffic engineers in the conduct and application of studies deemed essential to a solution of present and future problems of urban tra...

Station Platform-Railcar Threshold Gap Study

DOT National Transportation Integrated Search

1982-03-01

This study was conducted for the Transportation Systems Center by the Veterans Administration Rehabilitation Engineering Center (VAREC). It is part of a program to improve railcar accessibility for the handicapped riders. The purpose of this investig...

Engineering Encounters: Engineering Adaptations

ERIC Educational Resources Information Center

Gatling, Anne; Vaughn, Meredith Houle

2015-01-01

Engineering is not a subject that has historically been taught in elementary schools, but with the emphasis on engineering in the "Next Generation Science Standards," curricula are being developed to explicitly teach engineering content and design. However, many of the scientific investigations already conducted with students have…

Researches on Preliminary Chemical Reactions in Spark-Ignition Engines

NASA Technical Reports Server (NTRS)

Muehlner, E.

1943-01-01

Chemical reactions can demonstrably occur in a fuel-air mixture compressed in the working cylinder of an Otto-cycle (spark ignition) internal-combustion engine even before the charge is ignited by the flame proceeding from the sparking plug. These are the so-called "prelinminary reactions" ("pre-flame" combustion or oxidation), and an exact knowledge of their characteristic development is of great importance for a correct appreciation of the phenomena of engine-knock (detonation), and consequently for its avoidance. Such reactions can be studied either in a working engine cylinder or in a combustion bomb. The first method necessitates a complicated experimental technique, while the second has the disadvantage of enabling only a single reaction to be studied at one time. Consequently, a new series of experiments was inaugurated, conducted in a motored (externally-driven) experimental engine of mixture-compression type, without ignition, the resulting preliminary reactions being detectable and measurable thermometrically.

Investigation of Deposit Formation Mechanisms for Engine In-cylinder Combustion and Exhaust Systems Using Quantitative Analysis and Sustainability Study

NASA Astrophysics Data System (ADS)

Ye, Z.; Meng, Q.; Mohamadian, H. P.; Wang, J. T.; Chen, L.; Zhu, L.

2007-06-01

The formation of SI engine combustion deposits is a complex phenomenon which depends on various factors of fuel, oil, additives, and engine. The goal of this study is to examine the effects of operating conditions, gasoline, lubricating oil, and additives on deposit formation. Both an experimental investigation and theoretical analysis are conducted on a single cylinder engine. As a result, the impact of deposits on engine performance and exhaust emissions (HC, NO x ) has been indicated. Using samples from a cylinder head and exhaust pipe as well as switching gases via the dual-gas method (N2, O2), the deposit formation mechanism is thoroughly investigated via the thermogravity analysis approach, where the roles of organic, inorganic, and volatile components of fuel, additives, and oil on deposit formation are identified from thermogravity curves. Sustainable feedback control design is then proposed for potential emission control and performance optimization

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination.

PubMed

Shepard, Michele; Brenner, Sara

2014-01-01

Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace.

49 CFR Appendix E to Part 240 - Recommended Procedures for Conducting Skill Performance Tests

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Recommended Procedures for Conducting Skill... LOCOMOTIVE ENGINEERS Pt. 240, App. E Appendix E to Part 240—Recommended Procedures for Conducting Skill Performance Tests FRA requires (see § 240.127 and § 240.211) that locomotive engineers be given a skill...

Asbestos exposure from gaskets during disassembly of a medium duty diesel engine.

PubMed

Liukonen, Larry R; Weir, Francis W

2005-03-01

Diesel engines have historically used asbestos-containing gaskets leading to concerns of fiber release and mechanic exposure. Other published studies regarding asbestos fiber release during gasket removal have reported on short-duration events; were conducted under simulated work conditions; or had other limitations. There are no comprehensive studies relating to diesel engine gaskets under conditions similar to those reported herein, evaluating asbestos fiber release from gaskets during all facets of a complete disassembly and cleaning of a medium duty diesel engine in a busy repair and service shop by a journeyman mechanic. Asbestos content of all gaskets was identified; all disassembly tasks were described and timed; and personal and area air monitoring was conducted for each task. Twenty seven of thirty three gaskets contained chrysotile asbestos in concentrations that ranged from 5 to 70%. All but one air monitoring sample reported results below the limit of reliable detection even though plumes of visible dust were evident during various removal, cleaning, and buffing procedures. The detection limit for airborne asbestos fibers in this investigation was influenced by the presence of other shop dust in the air. Our investigation demonstrates that using shop-standard procedures in an established repair facility, a journeyman mechanic has very little potential for exposure to airborne asbestos fibers during disassembly of an engine, approximately 10% or less than that currently considered to be acceptable by OSHA.

Compressibility Effects in Aeronautical Engineering

NASA Technical Reports Server (NTRS)

Stack, John

1941-01-01

Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur. In the early phases of the development of the airplane, speeds were so low that the effects of compressibility could be justifiably ignored. During the last war and immediately after, however, propellers exhibited losses in efficiency as the tip speeds approached the speed of sound, and the first experiments of an aeronautical nature were therefore conducted with propellers. Results of these experiments indicated serious losses of efficiency, but aeronautical engineers were not seriously concerned at the time became it was generally possible. to design propellers with quite low tip. speeds. With the development of new engines having increased power and rotational speeds, however, the problems became of increasing importance.

Engine system assessment study using Martian propellants

NASA Technical Reports Server (NTRS)

Pelaccio, Dennis; Jacobs, Mark; Scheil, Christine; Collins, John

1992-01-01

A top-level feasibility study was conducted that identified and characterized promising chemical propulsion system designs which use two or more of the following propellant combinations: LOX/H2, LOX/CH4, and LOX/CO. The engine systems examined emphasized the usage of common subsystem/component hardware where possible. In support of this study, numerous mission scenarios were characterized that used various combinations of Earth, lunar, and Mars propellants to establish engine system requirements to assess the promising engine system design concept examined, and to determine overall exploration leverage of such systems compared to state-of-the-art cryogenic (LOX/H2) propulsion systems. Initially in the study, critical propulsion system technologies were assessed. Candidate expander and gas generator cycle LOX/H2/CO, LOX/H2/CH4, and LOX/CO/CH4 engine system designs were parametrically evaluated. From this evaluation baseline, tripropellant Mars Transfer Vehicle (MTV) LOX cooled and bipropellant Lunar Excursion Vehicle (LEV) and Mars Excursion Vehicle (MEV) engine systems were identified. Representative tankage designs for a MTV were also investigated. Re-evaluation of the missions using the baseline engine design showed that in general the slightly lower performance, smaller, lower weight gas generator cycle-based engines required less overall mission Mars and in situ propellant production (ISPP) infrastructure support compared to the larger, heavier, higher performing expander cycle engine systems.

Features of the gas dynamics and local heat transfer in intake system of piston engine with supercharging

NASA Astrophysics Data System (ADS)

Plotnikov, L. V.

2017-09-01

Comparison of experimental research results of gas dynamics and instantaneous local heat transfer in the intake pipes for piston internal combustion engines (ICE) without and with supercharging are presented in the article. Studies were conducted on full-scale experimental setups in terms of gas dynamic nonstationarity, which is characteristic of piston engines. It has been established that the turbocharger installation in a gas-air system of piston internal combustion engine leads to significant differences in the patterns of change in gas-dynamic and heat transfer characteristics of flows. These data can be used in a modernization of piston engines due to installation of a turbocharger or in a development of gas-air systems for piston ICE with supercharging.

Preliminary Study on Acoustic Detection of Faults Experienced by a High-Bypass Turbofan Engine

NASA Technical Reports Server (NTRS)

Boyle, Devin K.

2014-01-01

The vehicle integrated propulsion research (VIPR) effort conducted by NASA and several partners provided an unparalleled opportunity to test a relatively low TRL concept regarding the use of far field acoustics to identify faults occurring in a high bypass turbofan engine. Though VIPR Phase II ground based aircraft installed engine testing wherein a multitude of research sensors and methods were evaluated, an array of acoustic microphones was used to determine the viability of such an array to detect failures occurring in a commercially representative high bypass turbofan engine. The failures introduced during VIPR testing included commanding the engine's low pressure compressor (LPC) exit and high pressure compressor (HPC) 14th stage bleed values abruptly to their failsafe positions during steady state

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.

Studies and analyses of the space shuttle main engine

NASA Technical Reports Server (NTRS)

Tischer, Alan E.; Glover, R. C.

1987-01-01

The primary objectives were to: evaluate ways to maximize the information yield from the current Space Shuttle Main Engine (SSME) condition monitoring sensors, identify additional sensors or monitoring capabilities which would significantly improve SSME data, and provide continuing support of the Main Engine Cost/Operations (MECO) model. In the area of SSME condition monitoring, the principal tasks were a review of selected SSME failure data, a general survey of condition monitoring, and an evaluation of the current engine monitoring system. A computerized data base was developed to assist in modeling engine failure information propagations. Each of the above items is discussed in detail. Also included is a brief discussion of the activities conducted in support of the MECO model.

An analysis of the booster plume impingement environment during the space shuttle nominal staging maneuver

NASA Technical Reports Server (NTRS)

Wojciechowski, C. J.; Penny, M. M.; Greenwood, T. F.; Fossler, I. H.

1972-01-01

An experimental study of the plume impingement heating on the space shuttle booster afterbody resulting from the space shuttle orbiter engine plumes was conducted. The 1/100-scale model tests consisted of one and two orbiter engine firings on a flat plate, a flat plate with a fin, and a cylinder model. The plume impingement heating rates on these surfaces were measured using thin film heat transfer gages. Results indicate the engine simulation is a reasonable approximation to the two engine configuration, but more tests are needed to verify the plume model of the main engine configuration. For impingment, results show models experienced laminar boundary layer convective heating. Therefore, tests at higher Reynolds numbers are needed to determine impingment heating.

An exploratory survey on the views of European tissue engineers concerning the ethical issues of tissue engineering research.

PubMed

Trommelmans, Leen; Selling, Joseph; Dierickx, Kris

2009-09-01

We present the first exploratory survey about the views of tissue engineers on the ethical issues of tissue engineering (TE), conducted among participants of a large European TE consortium. We analyzed the topics for which ethical guidance is necessary and the preferred dissemination channels, which are relevant issues and goals of clinical trials with human tissue-engineered products, and which information is to be given to trial participants. The need for comprehensive, specific ethical guidance of TE is a first key finding of this survey. Second, it becomes clear that little clarity exists on some crucial issues in the setup and conduct of clinical trials in TE. Identifying the unique features of TE and their repercussions for the ethical conduct of TE research and therapy is necessary. Third, prospective trial participants are to be informed about a wide variety of issues before taking part in the trial.

First-year engineering students' views of the nature of engineering

NASA Astrophysics Data System (ADS)

Karatas, Faik O.

The changing nature of engineering problems and new challenges that result from globalization and new ways of doing business have triggered calls for a revolutionary shift in engineering education. To respond to these challenges, the engineering education paradigm has been revised by adding more design and humanities/social sciences components to it. Philosophy, sociology, and history of engineering are more often cited as a major part of engineering education in this movement. Research on the nature of engineering (NOE), which is derived from philosophy, sociology, and the history of engineering, could have as much potential impact on engineering education as research on the nature of science (NOS) has had on science education. Thus, it is surprising that there has been no noteworthy research on this topic. The purpose of this study is to describe and determine first-year engineering students' views of the NOE and how these students differentiate engineering from science. In this research, an open-ended Views of the Nature of Engineering questionnaire (VNOE) was employed to collect baseline data. Semi-structured interviews based on the VNOE questionnaire were conducted with the second cohort of the participants. Data analysis was guided by a traditional phenomenographic approach, which is a branch of the hermeneutic tradition, coupled to constant comparison technique. The results of this study indicated that the participants' overall views of the nature of engineering were not ill-developed, but rather unarticulated. Moreover, the relationship between engineering and science was considered unidirectional rather than bidirectional. The results of this study could be used to inform engineering educators, first-year engineering coordinators, and policy makers as well as serving as the base for further research and potential implications for future first-year and K-12 engineering education.

Methods for heat transfer and temperature field analysis of the insulated diesel phase 2 progress report

NASA Technical Reports Server (NTRS)

Morel, T.; Kerlbar, R.; Fort, E. F.; Blumberg, P. N.

1985-01-01

This report describes work done during Phase 2 of a 3 year program aimed at developing a comprehensive heat transfer and thermal analysis methodology for design analysis of insulated diesel engines. The overall program addresses all the key heat transfer issues: (1) spatially and time-resolved convective and radiative in-cylinder heat transfer, (2) steady-state conduction in the overall structure, and (3) cyclical and load/speed temperature transients in the engine structure. During Phase 2, radiation heat transfer model was developed, which accounts for soot formation and burn up. A methodology was developed for carrying out the multi-dimensional finite-element heat conduction calculations within the framework of thermodynamic cycle codes. Studies were carried out using the integrated methodology to address key issues in low heat rejection engines. A wide ranging design analysis matrix was covered, including a variety of insulation strategies, recovery devices and base engine configurations. A single cylinder Cummins engine was installed at Purdue University, and it was brought to a full operational status. The development of instrumentation was continued, concentrating on radiation heat flux detector, total heat flux probe, and accurate pressure-crank angle data acquisition.

Transatmospheric vehicle research

NASA Technical Reports Server (NTRS)

Adelman, Henry G.; Cambier, Jean-Luc

1990-01-01

Research was conducted into the alternatives to the supersonic combustion ramjet (scramjet) engine for hypersonic flight. A new engine concept, the Oblique Detonation Wave Engine (ODWE) was proposed and explored analytically and experimentally. Codes were developed which can couple the fluid dynamics of supersonic flow with strong shock waves, with the finite rate chemistry necessary to model the detonation process. An additional study was conducted which compared the performance of a hypersonic vehicle powered by a scramjet or an ODWE. Engineering models of the overall performances of the two engines are included. This information was fed into a trajectory program which optimized the flight path to orbit. A third code calculated the vehicle size, weight, and aerodynamic characteristics. The experimental work was carried out in the Ames 20MW arc-jet wind tunnel, focusing on mixing and combustion of fuel injected into a supersonic airstream. Several injector designs were evaluated by sampling the stream behind the injectors and analyzing the mixture with an on-line mass spectrometer. In addition, an attempt was made to create a standing oblique detonation wave in the wind tunnel using hydrogen fuel. It appeared that the conditions in the test chamber were marginal for the generation of oblique detonation waves.

Engineering Students' Views of Corporate Social Responsibility: A Case Study from Petroleum Engineering.

PubMed

Smith, Jessica M; McClelland, Carrie J; Smith, Nicole M

2017-12-01

The mining and energy industries present unique challenges to engineers, who must navigate sometimes competing responsibilities and codes of conduct, such as personal senses of right and wrong, professional ethics codes, and their employers' corporate social responsibility (CSR) policies. Corporate social responsibility (CSR) is the current dominant framework used by industry to conceptualize firms' responsibilities to their stakeholders, yet has it plays a relatively minor role in engineering ethics education. In this article, we report on an interdisciplinary pedagogical intervention in a petroleum engineering seminar that sought to better prepare engineering undergraduate students to critically appraise the strengths and limitations of CSR as an approach to reconciling the interests of industry and communities. We find that as a result of the curricular interventions, engineering students were able to expand their knowledge of the social, rather than simply environmental and economic dimensions of CSR. They remained hesitant, however, in identifying the links between those social aspects of CSR and their actual engineering work. The study suggests that CSR may be a fruitful arena from which to illustrate the profoundly sociotechnical dimensions of the engineering challenges relevant to students' future careers.

Furnace Cyclic Oxidation Behavior of Multicomponent Low Conductivity Thermal Barrier Coatings

NASA Astrophysics Data System (ADS)

Zhu, Dongming; Nesbitt, James A.; Barrett, Charles A.; McCue, Terry R.; Miller, Robert A.

2004-03-01

Ceramic thermal barrier coatings (TBCs) will play an increasingly important role in advanced gas turbine engines due to their ability to further increase engine operating temperatures and reduce cooling, thus helping achieve future engine low emission, high efficiency, and improved reliability goals. Advanced multicomponent zirconia (ZrO2)-based TBCs are being developed using an oxide defect clustering design approach to achieve the required coating low thermal conductivity and high-temperature stability. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of the candidate coating materials was conducted using conventional furnace cyclic oxidation tests. In this paper, furnace cyclic oxidation behavior of plasma-sprayed ZrO2-based defect cluster TBCs was investigated at 1163°C using 45 min hot-time cycles. The ceramic coating failure mechanisms were studied using scanning electron microscopy (SEM) combined with x-ray diffraction (XRD) phase analysis after the furnace tests. The coating cyclic lifetime is also discussed in relation to coating processing, phase structures, dopant concentration, and other thermo-physical properties.

Furnace Cyclic Oxidation Behavior of Multi-Component Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Nesbitt, James A.; Barrett, Charles A.; McCue, Terry R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in advanced gas turbine engines because of their ability to further increase engine operating temperatures and reduce cooling, thus helping achieve future engine low emission, high efficiency and improved reliability goals. Advanced multi-component zirconia-based thermal barrier coatings are being developed using an oxide defect clustering design approach to achieve the required coating low thermal conductivity and high temperature stability. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of the candidate coating materials was conducted using conventional furnace cyclic oxidation tests. In this paper, furnace cyclic oxidation behavior of plasma-sprayed zirconia-based defect cluster thermal barrier coatings was investigated at 1163 C using 45 min hot cycles. The ceramic coating failure mechanisms were studied using scanning electron microscopy (SEM) combined with X-ray diffraction (XRD) phase analysis after the furnace tests. The coating cyclic lifetime is also discussed in relation to coating processing, phase structures, dopant concentration, and other thermo-physical properties.

Development and Testing of Ceramic Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. Durability of the coating systems remains a critical issue with the ever-increasing temperature requirements. Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to coating performance. There is a need to characterize the coating behavior and temperature limits, in order to potentially take full advantage of the current coating capability, and also accurately assess the benefit gained from advanced coating development. In this study, thermal conductivity behavior and cyclic durability of plasma-sprayed ZrO2-8wt%Y2O3 thermal barrier coatings were evaluated under laser heat-flux simulated high temperature, large thermal gradient and thermal cycling conditions. The coating degradation and failure processes were assessed by real-time monitoring of the coating thermal conductivity under the test conditions. The ceramic coating crack propagation driving forces and resulting failure modes will be discussed in light of high temperature mechanical fatigue and fracture testing results.

Development and Fatigue Testing of Ceramic Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Choi, Sung R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. Durability of the coating systems remains a critical issue with the ever-increasing temperature requirements. Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to coating performance. There is a need to characterize the coating thermal fatigue behavior and temperature limit, in order to potentially take full advantage of the current coating capability. In this study, thermal conductivity and cyclic fatigue behaviors of plasma-sprayed ZrO2-8wt%Y2O3 thermal barrier coatings were evaluated under high temperature, large thermal gradient and thermal cycling conditions. The coating degradation and failure processes were assessed by real-time monitoring of the coating thermal conductivity under the test conditions. The ceramic coating crack initiation and propagation driving forces and failure modes under the cyclic thermal loads will be discussed in light of the high temperature mechanical fatigue and fracture testing results.

Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines

NASA Technical Reports Server (NTRS)

Joachim, William F; Rothrock, A M

1930-01-01

This investigation on the vapor pressure of fuels was conducted in connection with the general research on combustion in fuel injection engines. The purpose of the investigation was to study the effects of high temperatures such as exist during the first stages of injection on the vapor pressures of several fuels and certain fuel mixtures, and the relation of these vapor pressures to the preparation of the fuel for combustion in high-speed fuel injection engines.

Improving aircraft energy efficiency

NASA Technical Reports Server (NTRS)

Povinelli, F. P.; Klineberg, J. M.; Kramer, J. J.

1976-01-01

Investigations conducted by a NASA task force concerning the development of aeronautical fuel-conservation technology are considered. The task force estimated the fuel savings potential, prospects for implementation in the civil air-transport fleet, and the impact of the technology on air-transport fuel use. Propulsion advances are related to existing engines in the fleet, to new production of current engine types, and to new engine designs. Studies aimed at the evolutionary improvement of aerodynamic design and a laminar flow control program are discussed and possibilities concerning the use of composite structural materials are examined.

[Projects to accelerate the practical use of innovative medical devices to collaborate with TWIns, Center for Advanced Biomedical Sciences, Waseda University and School of Engineering, The University of Tokyo].

PubMed

Niimi, Shingo; Umezu, Mitsuo; Iseki, Hiroshi; Harada, Hiroshi Kasanuki Noboru; Mitsuishi, Mamoru; Kitamori, Takehiko; Tei, Yuichi; Nakaoka, Ryusuke; Haishima, Yuji

2014-01-01

Division of Medical Devices has been conducting the projects to accelerate the practical use of innovative medical devices to collaborate with TWIns, Center for Advanced Biomedical Sciences, Waseda University and School of Engineering, The University of Tokyo. The TWIns has been studying to aim at establishment of preclinical evaluation methods by "Engineering Based Medicine", and established Regulatory Science Institute for Medical Devices. School of Engineering, The University of Tokyo has been studying to aim at establishment of assessment methodology for innovative minimally invasive therapeutic devices, materials, and nanobio diagnostic devices. This report reviews the exchanges of personnel, the implement systems and the research progress of these projects.

Study of stator-vane fluctuating pressures in a turbofan engine for static and flight tests

NASA Technical Reports Server (NTRS)

Mueller, A. W.

1984-01-01

As part of a program to study the fan noise generated from turbofan engines, fluctuating surface pressures induced by fan-rotor wakes were measured on core- and bypass-stator outlet guide vanes of a modified JT15D-1 engine. Tests were conducted with the engine operating on an outdoor test stand and in flight. The amplitudes of pressures measured at fan-rotor blade-passage fundamental frequencies were generally higher and appeared less stable for the static tests than for the flight tests. Fluctuating pressures measured at the blade-passage frequency of the high-speed core compressor were interpreted to be acoustic; however, disturbance trace velocities for either the convected rotor wakes or acoustic pressures were difficult to interpret because of the complex environment.

Investigation of ecological parameters of four-stroke SI engine, with pneumatic fuel injection system

NASA Astrophysics Data System (ADS)

Marek, W.; Śliwiński, K.

2016-09-01

The publication presents the results of tests to determine the impact of using waste fuels, alcohol, to power the engine, on the ecological parameters of the combustion engine. Alternatively fuelled with a mixture of iso- and n-butanol, indicated with "X" and "END, and gasoline and a mixture of fuel and alcohol. The object of the study was a four-stroke engine with spark ignition designed to work with a generator. Motor power was held by the modified system of pneumatic injection using hot exhaust gases developed by Prof. Stanislaw Jarnuszkiewicz, controlled by modern mechatronic systems. Tests were conducted at a constant speed for the intended use of the engine. The subject of the research was to determine the control parameters such as ignition timing, mixture composition and the degree of exhaust gas recirculation on the ecological parameters of the engine. Tests were carried out using partially quality power control. In summary we present the findings of this phase of the study.

Piloted simulation study of the effects of an automated trim system on flight characteristics of a light twin-engine airplane with one engine inoperative

NASA Technical Reports Server (NTRS)

Stewart, E. C.; Brown, P. W.; Yenni, K. R.

1986-01-01

A simulation study was conducted to investigate the piloting problems associated with failure of an engine on a generic light twin-engine airplane. A primary piloting problem for a light twin-engine airplane after an engine failure is maintaining precise control of the airplane in the presence of large steady control forces. To address this problem, a simulated automatic trim system which drives the trim tabs as an open-loop function of propeller slipstream measurements was developed. The simulated automatic trim system was found to greatly increase the controllability in asymmetric powered flight without having to resort to complex control laws or an irreversible control system. However, the trim-tab control rates needed to produce the dramatic increase in controllability may require special design consideration for automatic trim system failures. Limited measurements obtained in full-scale flight tests confirmed the fundamental validity of the proposed control law.

Manipulating dispersion and distribution of graphene in PLA through Novel Interface Engineering for improved conductive properties

USDA-ARS?s Scientific Manuscript database

This study aimed to enhance the conductive properties of PLA nanocomposite by controlling the dispersion and distribution of graphene within the minor phase of the polymer blend. Functionalized graphene (f-GO) was achieved by reacting graphene oxide (GO) with various silanes under the aid of an ioni...

Manipulating dispersion and distribution of graphene in PLA through novel interface engineering for improved conductive properties

USDA-ARS?s Scientific Manuscript database

This study aimed to enhance the conductive properties of PLA nanocomposite by controlling the dispersion and distribution of graphene within the minor phase of the polymer blend. Functionalized graphene (f-GO) was achieved by reacting graphene oxide (GO) with various silanes under the aid of an ioni...

a Study of Women Engineering Students and Time to Completion of First-Year Required Courses at Texas A&M University

NASA Astrophysics Data System (ADS)

Kimball, Jorja; Cole, Bryan; Hobson, Margaret; Watson, Karan; Stanley, Christine

This paper reports findings on gender that were part of a larger study reviewing time to completion of course work that includes the first two semesters of calculus, chemistry, and physics, which are often considered the stumbling points or "barrier courses" to an engineering baccalaureate degree. Texas A&M University terms these courses core body of knowledge (CBK), and statistical analysis was conducted on two cohorts of first-year enrolling engineering students at the institution. Findings indicate that gender is statistically significantly related to completion of CBK with female engineering students completing required courses faster than males at the .01 level (p = 0.008). Statistical significance for gender and ethnicity was found between white male and white female students at the .01 level (p = 0.008). Descriptive analysis indicated that of the five majors studied (chemical, civil, computer, electrical, and mechanical engineering), women completed CBK faster than men, and African American and Hispanic women completed CBK faster than males of the same ethnicity.

Antimisting kerosene JT3 engine fuel system integration study

NASA Technical Reports Server (NTRS)

Fiorentino, A.

1987-01-01

An analytical study and laboratory tests were conducted to assist NASA in determining the safety and mission suitability of the modified fuel system and flight tests for the Full-Scale Transport Controlled Impact Demonstration (CID) program. This twelve-month study reviewed and analyzed both the use of antimisting kerosene (AMK) fuel and the incorporation of a fuel degrader on the operational and performance characteristics of the engines tested. Potential deficiencies and/or failures were identified and approaches to accommodate these deficiencies were recommended to NASA Ames -Dryden Flight Research Facility. The result of flow characterization tests on degraded AMK fuel samples indicated levels of degradation satisfactory for the planned missions of the B-720 aircraft. The operability and performance with the AMK in a ground test engine and in the aircraft engines during the test flights were comparable to those with unmodified Jet A. For the final CID test, the JT-3C-7 engines performed satisfactorily while operating on AMK right up to impact.

Large-Scale Wind-Tunnel Tests of Exhaust Ingestion Due to Thrust Reversal on a Four-Engine Jet Transport during Ground Roll

NASA Technical Reports Server (NTRS)

Tolhurst, William H., Jr.; Hickey, David H.; Aoyagi, Kiyoshi

1961-01-01

Wind-tunnel tests have been conducted on a large-scale model of a swept-wing jet transport type airplane to study the factors affecting exhaust gas ingestion into the engine inlets when thrust reversal is used during ground roll. The model was equipped with four small jet engines mounted in nacelles beneath the wing. The tests included studies of both cascade and target type reversers. The data obtained included the free-stream velocity at the occurrence of exhaust gas ingestion in the outboard engine and the increment of drag due to thrust reversal for various modifications of thrust reverser configuration. Motion picture films of smoke flow studies were also obtained to supplement the data. The results show that the free-stream velocity at which ingestion occurred in the outboard engines could be reduced considerably, by simple modifications to the reversers, without reducing the effective drag due to reversed thrust.

Impact of Cognitive-Based Instructional Intervention on Learning Motivation: The Implementation of Student-Made Glossary in a Programming-Oriented Engineering Problem-Solving Course and Its Impact on Learning Motivation

ERIC Educational Resources Information Center

Huang, David Wenhao; Aagard, Hans; Diefes-Dux, Heidi

2004-01-01

This article describes the purpose, development, and implementation of a cognitive-based instructional intervention and its impact on learning motivation. The study was conducted in a programming-based problemsolving course for first-year engineering students. The results suggest that the instructional intervention developed based on the…

Manufacturing Industries with High Concentrations of Scientists and Engineers Lead in 1965-77 Employment Growth. Science Resources Studies Highlights, April 20, 1979.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC. Div. of Science Resources Studies.

Presented are the results of a survey of over 100,000 manufacturing establishments, conducted for the National Science Foundation by the Bureau of Labor Statistics, covering average annual employment for calendar year 1977. Industries whose relative concentration of scientists and engineers was high in 1977, such as petroleum refining, chemicals,…

Starter/generator testing

NASA Astrophysics Data System (ADS)

Anon

1994-10-01

Sundstrand Aerospace and GE Aircraft Engines have studied the switched reluctance machine for use as an integral starter/generator for future aircraft engines. They have conducted an initial, low-power testing of the starter/generator, which is based on power inverters using IGBT-technology semiconductors, to verify its feasibility in the externally mounted version of the integral starter/generator. This preliminary testing of the 250-kW starter/generator reveals favorable results.

Recruitment and Workplace Integration of Men and Women Engineers in France: The Case of EPF Ecole D'ingénieurs Graduates

ERIC Educational Resources Information Center

Stevanovic, Biljana

2014-01-01

Based on "First Job" surveys conducted six months after graduation among graduates from 2000 to 2007 and semi-structured interviews, this paper examines the recruitment and workplace integration of women and men graduates from EPF Ecole d'Ingenieurs. The study's findings show that women engineering graduates from EPF generally have more…

A Study of Current Trends and Issues for Graphics Education: Results from a Five-Year Follow-Up Survey

ERIC Educational Resources Information Center

Clark, Aaron C.; Scales, Alice Y.

2006-01-01

During the 1998-1999 academic year, a survey was conducted to look at current trends and issues in the profession of graphics education (Clark & Scales, 1999). The survey solicited information from the membership of the Engineering Design Graphics Division of the American Society for Engineering Education related to their view of future areas of…

Dropouts and Budgets: A Test of a Dropout Reduction Model among Students in Israeli Higher Education

ERIC Educational Resources Information Center

Bar-Am, Ran; Arar, Osama

2017-01-01

This article deals with the problem of student dropout during the first year in a higher education institution. To date, no model on a budget has been developed and tested to prevent dropout among Engineering Students. This case study was conducted among first-year students taking evening classes in two practical engineering colleges in Israel.…

Preliminary Results From a Heavily Instrumented Engine Ice Crystal Icing Test in a Ground Based Altitude Test Facility

NASA Technical Reports Server (NTRS)

Flegel, Ashlie B.; Oliver, Michael J.

2016-01-01

Preliminary results from the Heavily Instrumented ALF503R-5 Engine test conducted in the NASA Glenn Research Center Propulsion Systems Laboratory will be discussed. The effects of ice crystal icing on a full scale engine is examined and documented. This model engine, serial number LF01, was used during the inaugural icing test in the PSL facility. The reduction of thrust (rollback) events experienced by this engine in flight were replicated in the facility. Limited instrumentation was used to detect icing. Metal temperature on the exit guide vanes and outer shroud and the load measurement were the only indicators of ice formation. The current study features a similar engine, serial number LF11, which is instrumented to characterize the cloud entering the engine, detect characterize ice accretion, and visualize the ice accretion in the region of interest.

Teen smoking cessation help via the Internet: a survey of search engines.

PubMed

Edwards, Christine C; Elliott, Sean P; Conway, Terry L; Woodruff, Susan I

2003-07-01

The objective of this study was to assess Web sites related to teen smoking cessation on the Internet. Seven Internet search engines were searched using the keywords teen quit smoking. The top 20 hits from each search engine were reviewed and categorized. The keywords teen quit smoking produced between 35 and 400,000 hits depending on the search engine. Of 140 potential hits, 62% were active, unique sites; 85% were listed by only one search engine; and 40% focused on cessation. Findings suggest that legitimate on-line smoking cessation help for teens is constrained by search engine choice and the amount of time teens spend looking through potential sites. Resource listings should be updated regularly. Smoking cessation Web sites need to be picked up on multiple search engine searches. Further evaluation of smoking cessation Web sites need to be conducted to identify the most effective help for teens.

Modeling and Control Systems Design for Air Intake System of Diesel Engines for Improvement of Transient Characteristic

NASA Astrophysics Data System (ADS)

Ejiri, Arata; Sasaki, Jun; Kinoshita, Yusuke; Fujimoto, Junya; Maruyama, Tsugito; Shimotani, Keiji

For the purpose of contributing to global environment protection, several research studies have been conducted involving clean-burning diesel engines. In recent diesel engines with Exhaust Gas Recirculation (EGR) systems and a Variable Nozzle Turbocharger (VNT), mutual interference between EGR and VNT has been noted. Hence, designing and adjusting control of the conventional PID controller is particularly difficult at the transient state in which the engine speed and fuel injection rate change. In this paper, we formulate 1st principal model of air intake system of diesel engines and transform it to control oriented model including an engine steady state model and a transient model. And we propose a model-based control system with the LQR Controller, Saturation Compensator, the Dynamic Feed-forward and Disturbance Observer using a transient model. Using this method, we achieved precise reference tracking and emission reduction in transient mode test with the real engine evaluations.

Occupational exposures to leaded and unleaded gasoline engine emissions and lung cancer risk.

PubMed

Xu, Mengting; Siemiatycki, Jack; Lavoué, Jérôme; Pasquet, Romain; Pintos, Javier; Rousseau, Marie-Claude; Richardson, Lesley; Ho, Vikki

2018-04-01

To determine whether occupational exposure to gasoline engine emissions (GEE) increased the risk of lung cancer and more specifically whether leaded or unleaded GEE increased the risk. Two population-based case-control studies were conducted in Montreal, Canada. The first was conducted in the early 1980s and included many types of cancer including lung cancer. The second was conducted in the late 1990s and focused on lung cancer. Population controls were used in both studies. Altogether, there were 1595 cases and 1432 population controls. A comprehensive expert-based exposure assessment procedure was implemented and exposure was assessed for 294 agents, including unleaded GEE, leaded GEE and diesel engine emissions (DEE). Logistic regression analyses were conducted to estimate ORs between various metrics of GEE exposure and lung cancer, adjusting for smoking, DEE and other potential confounders. About half of all controls were occupationally exposed to GEE. Irrespective of the metrics of exposure (any exposure, duration of exposure and cumulative exposure) and the type of lung cancer, and the covariates included in models, none of the point estimates of the ORs between occupational exposure to leaded or unleaded GEE and lung cancer were above 1.0. Pooling two studies, the OR for any exposure to leaded GEE was 0.82 (0.68-1.00). Our results do not support the hypothesis that occupational exposure to GEE increases the risk of lung cancer. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

From Usability Testing to Clinical Simulations: Bringing Context into the Design and Evaluation of Usable and Safe Health Information Technologies. Contribution of the IMIA Human Factors Engineering for Healthcare Informatics Working Group.

PubMed

Kushniruk, A; Nohr, C; Jensen, S; Borycki, E M

2013-01-01

The objective of this paper is to explore human factors approaches to understanding the use of health information technology (HIT) by extending usability engineering approaches to include analysis of the impact of clinical context through use of clinical simulations. Methods discussed are considered on a continuum from traditional laboratory-based usability testing to clinical simulations. Clinical simulations can be conducted in a simulation laboratory and they can also be conducted in real-world settings. The clinical simulation approach attempts to bring the dimension of clinical context into stronger focus. This involves testing of systems with representative users doing representative tasks, in representative settings/environments. Application of methods where realistic clinical scenarios are used to drive the study of users interacting with systems under realistic conditions and settings can lead to identification of problems and issues with systems that may not be detected using traditional usability engineering methods. In conducting such studies, careful consideration is needed in creating ecologically valid test scenarios. The evidence obtained from such evaluation can be used to improve both the usability and safety of HIT. In addition, recent work has shown that clinical simulations, in particular those conducted in-situ, can lead to considerable benefits when compared to the costs of running such studies. In order to bring context of use into the testing of HIT, clinical simulation, involving observing representative users carrying out tasks in representative settings, holds considerable promise.

An Update of the Nation's Long-Term Strategic Needs for NASA's Aeronautics Test Facilities

NASA Technical Reports Server (NTRS)

Anton, Philip S.; Raman, Raj; Osburg, Jan; Kallimani, James G.

2009-01-01

The National Aeronautics and Space Administration's (NASA's) major wind tunnel (WT), propulsion test (PT), and simulation facilities exist to serve NASA's and the nation's aeronautics needs. RAND Corporation researchers conducted a prior study of these facilities from 2002 to 2003, identifying (1) NASA's continuing ability to serve national needs, (2) which facilities appear strategically important from an engineering perspective given the vehicle classes the nation investigates and produces, and (3) management challenges and issues. This documented briefing (DB) is the final report from a new, one-year study (conducted from September 2006 through January 2008), partially updating the prior assessment. The study focuses on updating the list of facilities in the prior study that were deemed to be strategically important (again, from an engineering perspective) in serving those needs. This update also adds a new assessment of national needs for six major aeronautics simulators at NASA and lists those deemed strategically important.

Effects of Gasoline Direct Injection Engine Operating Parameters on Particle Number Emissions

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

He, X.; Ratcliff, M. A.; Zigler, B. T.

2012-04-19

A single-cylinder, wall-guided, spark ignition direct injection engine was used to study the impact of engine operating parameters on engine-out particle number (PN) emissions. Experiments were conducted with certification gasoline and a splash blend of 20% fuel grade ethanol in gasoline (E20), at four steady-state engine operating conditions. Independent engine control parameter sweeps were conducted including start of injection, injection pressure, spark timing, exhaust cam phasing, intake cam phasing, and air-fuel ratio. The results show that fuel injection timing is the dominant factor impacting PN emissions from this wall-guided gasoline direct injection engine. The major factor causing high PN emissionsmore » is fuel liquid impingement on the piston bowl. By avoiding fuel impingement, more than an order of magnitude reduction in PN emission was observed. Increasing fuel injection pressure reduces PN emissions because of smaller fuel droplet size and faster fuel-air mixing. PN emissions are insensitive to cam phasing and spark timing, especially at high engine load. Cold engine conditions produce higher PN emissions than hot engine conditions due to slower fuel vaporization and thus less fuel-air homogeneity during the combustion process. E20 produces lower PN emissions at low and medium loads if fuel liquid impingement on piston bowl is avoided. At high load or if there is fuel liquid impingement on piston bowl and/or cylinder wall, E20 tends to produce higher PN emissions. This is probably a function of the higher heat of vaporization of ethanol, which slows the vaporization of other fuel components from surfaces and may create local fuel-rich combustion or even pool-fires.« less

Reliability and Probabilistic Risk Assessment - How They Play Together

NASA Technical Reports Server (NTRS)

Safie, Fayssal M.; Stutts, Richard G.; Zhaofeng, Huang

2015-01-01

PRA methodology is one of the probabilistic analysis methods that NASA brought from the nuclear industry to assess the risk of LOM, LOV and LOC for launch vehicles. PRA is a system scenario based risk assessment that uses a combination of fault trees, event trees, event sequence diagrams, and probability and statistical data to analyze the risk of a system, a process, or an activity. It is a process designed to answer three basic questions: What can go wrong? How likely is it? What is the severity of the degradation? Since 1986, NASA, along with industry partners, has conducted a number of PRA studies to predict the overall launch vehicles risks. Planning Research Corporation conducted the first of these studies in 1988. In 1995, Science Applications International Corporation (SAIC) conducted a comprehensive PRA study. In July 1996, NASA conducted a two-year study (October 1996 - September 1998) to develop a model that provided the overall Space Shuttle risk and estimates of risk changes due to proposed Space Shuttle upgrades. After the Columbia accident, NASA conducted a PRA on the Shuttle External Tank (ET) foam. This study was the most focused and extensive risk assessment that NASA has conducted in recent years. It used a dynamic, physics-based, integrated system analysis approach to understand the integrated system risk due to ET foam loss in flight. Most recently, a PRA for Ares I launch vehicle has been performed in support of the Constellation program. Reliability, on the other hand, addresses the loss of functions. In a broader sense, reliability engineering is a discipline that involves the application of engineering principles to the design and processing of products, both hardware and software, for meeting product reliability requirements or goals. It is a very broad design-support discipline. It has important interfaces with many other engineering disciplines. Reliability as a figure of merit (i.e. the metric) is the probability that an item will perform its intended function(s) for a specified mission profile. In general, the reliability metric can be calculated through the analyses using reliability demonstration and reliability prediction methodologies. Reliability analysis is very critical for understanding component failure mechanisms and in identifying reliability critical design and process drivers. The following sections discuss the PRA process and reliability engineering in detail and provide an application where reliability analysis and PRA were jointly used in a complementary manner to support a Space Shuttle flight risk assessment.

Examining the Personal Nature of the K-14 Engineering Pipeline for Young Women

NASA Astrophysics Data System (ADS)

Gurski, Jennifer Sue

This mixed-methods study examined young women's perceptions of their K-14 STEM pipeline experiences and their resulting choice to enter and persist in an engineering major. Despite the increase of women in the STEM workforce, women remain underrepresented among engineering majors (Beasley & Fischer, 2012; Heilbronner, 2012; Neihart & Teo, 2013). Few studies exist that utilize a retrospective approach to understand how the culmination of young women's K-14 experiences have influenced their formation of individually held perceptions that lead to engineering persistence. It is this study's aim to utilize a mixed-methods approach to answer the following research question: How do young women's perceptions of their K-14 STEM experiences influence their decision to enroll and persist in an engineering major? These perceptions are explored through an ethnographic approach focusing on young women enrolled in engineering programs during their junior and senior years of study at a small private liberal arts university with eight engineering majors. The mixed-methods approach follows a sequential design method (Creswell, 2013) and utilizes questions in a quantitative Likert-type survey from the Academic Pathways for People Learning Engineering (APPLES) survey (Eris, Chachra, Chen, Sheppard, & Ludlow, 2010) and the Motivated Strategy Learning Questionnaire (MSLQ) (Pintrich, Smith, Garcia, & McKeachie, 1991). The quantitative study results will lead to the development of open-ended, structured questions for conducting a qualitative focus group. Anonymity of all participants is maintained. Keywords: STEM, young women, perceptions, pipeline, intervention, underrepresentation, engineering, persistence, retrospective, self-efficacy.

Concurrent and Collaborative Engineering Implementation in an R and D Organization

NASA Technical Reports Server (NTRS)

DelRosario, Ruben; Davis, Jose M.; Keys, L. Ken

2003-01-01

Concurrent Engineering (CE), and Collaborative Engineering (or Collaborative Product Development - CPD) have emerged as new paradigms with significant impact in the development of new products and processes. With documented and substantiated success in the automotive and technology industries CE and, most recently, CPD are being touted as innovative management philosophies for many other business sectors including Research and De- velopment. This paper introduces two independent research initiatives conducted at the NASA Glenn Research Center (GRC) in Cleveland, Ohio investigating the application of CE and CPD in an RdiD environment. Since little research has been conducted in the use of CE and CPD in sectors other than the high mass production manufacturing, the objective of these independent studies is to provide a systematic evaluation of the applicability of these paradigms (concur- rent and collaborative) in a low/no production, service environment, in particular R&D.

Performance Cycle Analysis of a Two-Spool, Separate-Exhaust Turbofan With Interstage Turbine Burner

NASA Technical Reports Server (NTRS)

Liew, K. H.; Urip, E.; Yang, S. L.; Mattingly, J. D.; Marek, C. J.

2005-01-01

This paper presents the performance cycle analysis of a dual-spool, separate-exhaust turbofan engine, with an Interstage Turbine Burner serving as a secondary combustor. The ITB, which is located at the transition duct between the high- and the low-pressure turbines, is a relatively new concept for increasing specific thrust and lowering pollutant emissions in modern jet engine propulsion. A detailed performance analysis of this engine has been conducted for steady-state engine performance prediction. A code is written and is capable of predicting engine performances (i.e., thrust and thrust specific fuel consumption) at varying flight conditions and throttle settings. Two design-point engines were studied to reveal trends in performance at both full and partial throttle operations. A mission analysis is also presented to assure the advantage of saving fuel by adding ITB.

Sustainability Metrics of a Small Scale Turbojet Engine

NASA Astrophysics Data System (ADS)

Ekici, Selcuk; Sohret, Yasin; Coban, Kahraman; Altuntas, Onder; Karakoc, T. Hikmet

2018-05-01

Over the last decade, sustainable energy consumption has attracted the attention of scientists and researchers. The current paper presents sustainability indicators of a small scale turbojet engine, operated on micro-aerial vehicles, for discussion of the sustainable development of the aviation industry from a different perspective. Experimental data was obtained from an engine at full power load and utilized to conduct an exergy-based sustainability analysis. Exergy efficiency, waste exergy ratio, recoverable exergy ratio, environmental effect factor, exergy destruction factor and exergetic sustainability index are evaluated as exergetic sustainability indicators of the turbojet engine under investigation in the current study. The exergy efficiency of the small scale turbojet engine is calculated as 27.25 % whereas the waste exergy ratio, the exergy destruction factor and the sustainability index of the engine are found to be 0.9756, 0.5466 and 0.2793, respectively.

Numerical and flight measured interior noise characteristics of a twin-engine turboprop general aviation aircraft

NASA Astrophysics Data System (ADS)

Marulo, F.; Lecce, L.; de Rosa, S.; D'Amato, C. A.; Verde, G.

The paper presents the flight test results of an interior noise measurement campaign on a twin-engine turboprop general aviation aircraft conducted for assessing the real values inside such aircraft and for approaching the problem of its noise reduction. Simultaneously a numerical study has been performed in order to correlate the experimental and the theoretical values, trying to come out with some guidelines for possible improvements without increasing excessively the costs of such study.

Factors that facilitate or inhibit interest of domestic students in the engineering PhD: A mixed methods study

NASA Astrophysics Data System (ADS)

Howell Smith, Michelle C.

Given the increasing complexity of technology in our society, the United States has a growing demand for a more highly educated technical workforce. Unfortunately, the proportion of United States citizens earning a PhD in engineering has been declining and there is concern about meeting the economic, national security and quality of life needs of our country. This mixed methods sequential exploratory instrument design study identified factors that facilitate or inhibit interest in engineering PhD programs among domestic engineering undergraduate students in the United States. This study developed a testable theory for how domestic students become interested in engineering PhD programs and a measure of that process, the Exploring Engineering Interest Inventory (EEII). The study was conducted in four phases. The first phase of the study was a qualitative grounded theory exploration of interest in the engineering PhD. Qualitative data were collected from domestic engineering students, engineering faculty and industry professional who had earned a PhD in engineering. The second phase, instrument development, developed the Exploring Engineering Interest Inventory (EEII), a measurement instrument designed with good psychometric properties to test a series of preliminary hypotheses related to the theory generated in the qualitative phase. In the third phase of the study, the EEII was used to collect data from a larger sample of junior and senior engineering majors. The fourth phase integrated the findings from the qualitative and quantitative phases. Four factors were identified as being significant influences of interest in the engineering PhD: Personal characteristics, educational environment, misperceptions of the economic and personal costs, and misperceptions of engineering work. Recommendations include increasing faculty encouragement of students to pursue an engineering PhD and programming to correct the misperceptions of the costs of the engineering PhD and the nature of the work that PhD engineers do. The tested model provides engineering educators with information to help them prioritize their efforts to increase interest in the engineering PhD among domestic students.

Imaging Strategies for Tissue Engineering Applications

PubMed Central

Nam, Seung Yun; Ricles, Laura M.; Suggs, Laura J.

2015-01-01

Tissue engineering has evolved with multifaceted research being conducted using advanced technologies, and it is progressing toward clinical applications. As tissue engineering technology significantly advances, it proceeds toward increasing sophistication, including nanoscale strategies for material construction and synergetic methods for combining with cells, growth factors, or other macromolecules. Therefore, to assess advanced tissue-engineered constructs, tissue engineers need versatile imaging methods capable of monitoring not only morphological but also functional and molecular information. However, there is no single imaging modality that is suitable for all tissue-engineered constructs. Each imaging method has its own range of applications and provides information based on the specific properties of the imaging technique. Therefore, according to the requirements of the tissue engineering studies, the most appropriate tool should be selected among a variety of imaging modalities. The goal of this review article is to describe available biomedical imaging methods to assess tissue engineering applications and to provide tissue engineers with criteria and insights for determining the best imaging strategies. Commonly used biomedical imaging modalities, including X-ray and computed tomography, positron emission tomography and single photon emission computed tomography, magnetic resonance imaging, ultrasound imaging, optical imaging, and emerging techniques and multimodal imaging, will be discussed, focusing on the latest trends of their applications in recent tissue engineering studies. PMID:25012069

Keeping Disability in Mind: A Case Study in Implantable Brain-Computer Interface Research.

PubMed

Sullivan, Laura Specker; Klein, Eran; Brown, Tim; Sample, Matthew; Pham, Michelle; Tubig, Paul; Folland, Raney; Truitt, Anjali; Goering, Sara

2018-04-01

Brain-Computer Interface (BCI) research is an interdisciplinary area of study within Neural Engineering. Recent interest in end-user perspectives has led to an intersection with user-centered design (UCD). The goal of user-centered design is to reduce the translational gap between researchers and potential end users. However, while qualitative studies have been conducted with end users of BCI technology, little is known about individual BCI researchers' experience with and attitudes towards UCD. Given the scientific, financial, and ethical imperatives of UCD, we sought to gain a better understanding of practical and principled considerations for researchers who engage with end users. We conducted a qualitative interview case study with neural engineering researchers at a center dedicated to the creation of BCIs. Our analysis generated five themes common across interviews. The thematic analysis shows that participants identify multiple beneficiaries of their work, including other researchers, clinicians working with devices, device end users, and families and caregivers of device users. Participants value experience with device end users, and personal experience is the most meaningful type of interaction. They welcome (or even encourage) end-user input, but are skeptical of limited focus groups and case studies. They also recognize a tension between creating sophisticated devices and developing technology that will meet user needs. Finally, interviewees espouse functional, assistive goals for their technology, but describe uncertainty in what degree of function is "good enough" for individual end users. Based on these results, we offer preliminary recommendations for conducting future UCD studies in BCI and neural engineering.

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis and computer science

NASA Technical Reports Server (NTRS)

1987-01-01

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis, and computer science during the period April, 1986 through September 30, 1986 is summarized.

34 CFR 350.34 - Which Rehabilitation Engineering Research Centers must have an advisory committee?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 2 2013-07-01 2013-07-01 false Which Rehabilitation Engineering Research Centers must... Engineering Research Centers Does the Secretary Assist? § 350.34 Which Rehabilitation Engineering Research Centers must have an advisory committee? A Rehabilitation Engineering Research Center conducting research...

34 CFR 350.34 - Which Rehabilitation Engineering Research Centers must have an advisory committee?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Which Rehabilitation Engineering Research Centers must... Engineering Research Centers Does the Secretary Assist? § 350.34 Which Rehabilitation Engineering Research Centers must have an advisory committee? A Rehabilitation Engineering Research Center conducting research...

34 CFR 350.34 - Which Rehabilitation Engineering Research Centers must have an advisory committee?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 2 2014-07-01 2013-07-01 true Which Rehabilitation Engineering Research Centers must... Engineering Research Centers Does the Secretary Assist? § 350.34 Which Rehabilitation Engineering Research Centers must have an advisory committee? A Rehabilitation Engineering Research Center conducting research...

34 CFR 350.34 - Which Rehabilitation Engineering Research Centers must have an advisory committee?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true Which Rehabilitation Engineering Research Centers must... Engineering Research Centers Does the Secretary Assist? § 350.34 Which Rehabilitation Engineering Research Centers must have an advisory committee? A Rehabilitation Engineering Research Center conducting research...

34 CFR 350.34 - Which Rehabilitation Engineering Research Centers must have an advisory committee?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 2 2012-07-01 2012-07-01 false Which Rehabilitation Engineering Research Centers must... Engineering Research Centers Does the Secretary Assist? § 350.34 Which Rehabilitation Engineering Research Centers must have an advisory committee? A Rehabilitation Engineering Research Center conducting research...

Research on advanced transportation systems

NASA Astrophysics Data System (ADS)

Nagai, Hirokazu; Hashimoto, Ryouhei; Nosaka, Masataka; Koyari, Yukio; Yamada, Yoshio; Noda, Keiichirou; Shinohara, Suetsugu; Itou, Tetsuichi; Etou, Takao; Kaneko, Yutaka

1992-08-01

An overview of the researches on advanced space transportation systems is presented. Conceptual study is conducted on fly back boosters with expendable upper stage rocket systems assuming a launch capacity of 30 tons and returning to the launch site by the boosters, and prospect of their feasibility is obtained. Reviews are conducted on subjects as follows: (1) trial production of 10 tons sub scale engines for the purpose of acquiring hardware data and picking up technical problems for full scale 100 tons thrust engines using hydrocarbon fuels; (2) development techniques for advanced liquid propulsion systems from the aspects of development schedule, cost; (3) review of conventional technologies, and common use of component; (4) oxidant switching propulsion systems focusing on feasibility of Liquefied Air Cycle Engine (LACE) and Compressed Air Cycle Engine (CACE); (5) present status of slosh hydrogen manufacturing, storage, and handling; (6) construction of small high speed dynamometer for promoting research on mini pump development; (7) hybrid solid boosters under research all over the world as low-cost and clean propulsion systems; and (8) high performance solid propellant for upper stage and lower stage propulsion systems.

NOAA Atmospheric Sciences Modeling Division support to the US Environmental Protection Agency

NASA Astrophysics Data System (ADS)

Poole-Kober, Evelyn M.; Viebrock, Herbert J.

1991-07-01

During FY-1990, the Atmospheric Sciences Modeling Division provided meteorological research and operational support to the U.S. Environmental Protection Agency. Basic meteorological operational support consisted of applying dispersion models and conducting dispersion studies and model evaluations. The primary research effort was the development and evaluation of air quality simulation models using numerical and physical techniques supported by field studies. Modeling emphasis was on the dispersion of photochemical oxidants and particulate matter on urban and regional scales, dispersion in complex terrain, and the transport, transformation, and deposition of acidic materials. Highlights included expansion of the Regional Acid Deposition Model/Engineering Model family to consist of the Tagged Species Engineering Model, the Non-Depleting Model, and the Sulfate Tracking Model; completion of the Acid-MODES field study; completion of the RADM2.1 evaluation; completion of the atmospheric processes section of the National Acid Precipitation Assessment Program 1990 Integrated Assessment; conduct of the first field study to examine the transport and entrainment processes of convective clouds; development of a Regional Oxidant Model-Urban Airshed Model interface program; conduct of an international sodar intercomparison experiment; incorporation of building wake dispersion in numerical models; conduct of wind-tunnel simulations of stack-tip downwash; and initiation of the publication of SCRAM NEWS.

Small Engine Component Technology (SECT) study. Program report

NASA Technical Reports Server (NTRS)

Almodovar, E.; Exley, T.; Kaehler, H.; Schneider, W.

1986-01-01

The study was conducted to identify high payoff technologies for year 2000 small gas turbine applications and to provide a technology plan for guiding future research and technology efforts. A regenerative cycle turboprop engine was selected for a 19 passenger commuter aircraft application. A series of engines incorporating eight levels of advanced technologies were studied and their impact on aircraft performance was evaluated. The study indicated a potential reduction in fuel burn of 38.3 percent. At $1.00 per gallon fuel price, a potential DOC benefit of 12.5 percent would be achieved. At $2.00 per gallon, the potential DOC benefit would increase to 17.0 percent. Four advanced technologies are recommended and appropriate research and technology programs were established to reach the year 2000 goals.

Advanced Collaborative Emissions Study (ACES)

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

Greenbaum, Daniel; Costantini, Maria; Van Erp, Annemoon

2013-12-31

The objective of the Advanced Collaborative Emissions Study (ACES) was to determine before widespread commercial deployment whether or not the new, energy-efficient, heavy duty diesel engines (2007 and 2010 EPA Emissions Standards Compliant) may generate anticipated toxic emissions that could adversely affect the environment and human health. ACES was planned to take place in three phases. In Phase 1, extensive emissions characterization of four production-intent prototype engine and control systems designed to meet 2007 standards for nitrogen oxides (NOx) and particulate matter (PM) was conducted at an existing emissions characterization facility: Southwest Research Institute (SwRI). One of the tested enginesmore » was selected (at random, after careful comparison of results) for health testing in Phase 3. In Phase 2, extensive emission characterization of three production-intent prototype engine and control systems meeting the 2010 standards (including more advanced NOx controls to meet the more stringent 2010 NOx standards) was conducted at the same test facility. In Phase 3, one engine/aftertreatment system selected from Phase 1 was further characterized during health effects studies (at an existing inhalation toxicology laboratory: Lovelace Respiratory Research Institute, [LRRI]) to form the basis of the ACES safety assessment. The Department of Energy (DOE) award provided funding for emissions characterization in Phases 1 and 2 as well as exposure characterization in Phase 3. The main health analyses in Phase 3 were funded separately and are not reported here.« less

Study of Technological Improvements in Automobile Fuel Consumption : Volume 2. Comprehensive Discussion.

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Study of Technological Improvements in Automobile Fuel Consumption : Volume 1. Executive Summary.

DOT National Transportation Integrated Search

1974-02-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Advanced space engine preliminary design. [liquid hydrogen/liquid oxygen upper stage engine for space tug application

NASA Technical Reports Server (NTRS)

Zachary, A. T.

1973-01-01

Analysis and design of an optimum LO2/LH2, combustion topping cycle, 88,964 Newtons (20,000-pound) thrust, liquid rocket engine was conducted. The design selected is well suited to high-energy, upper-stage engine applications such as the Space Tug and embodies features directed toward optimization of vehicle performance. A configuration selection was conducted based on prior Air Force Contracts, and additional criteria for optimum stage performance. Following configuration selection, analyses and design of the major components and engine systems were conducted to sufficient depth to provide layout drawings suitable for subsequent detailing. In addition, engine packaging to a common interface and a retractable nozzle concept were defined. Alternative development plans and related costs were also established. The design embodies high-performance, low-weight, low NPSH requirements (saturated propellant inlet conditions at start), idle-mode operation, and autogenous pressurization. The design is the result of the significant past and current LO2/LH2 technology efforts of the NASA centers and the Air Force, as well as company-funded programs.

Critical needs for piston engine overhaul centre in Malaysia

NASA Astrophysics Data System (ADS)

Khairuddin, M. H.; Yahya, M. Y.; Johari, M. K.

2017-12-01

Piston engine overhaul centre (PEOC) is the branch of aviation Maintenance, Repair and Overhaul (MRO) providers, which plays a pivotal role in maintaining the fleet of business and commercial aircraft in the world. The centre typically offers three main MRO capabilities: airframe, engine and component services. Companies holding a PEOC(s) are all subjected to stringent procedures and conditions regulated and audited by the International Civil Aviation Organization. Currently, piston engine maintenance and repair for Asian countries is conducted only in Singapore. The focus of this study is to establish the needs for a PEOC in Malaysia, which will cater almost all small local aircraft companies such as transport and flying school companies.

SSME Key Operations Demonstration

NASA Technical Reports Server (NTRS)

Anderson, Brian; Bradley, Michael; Ives, Janet

1997-01-01

A Space Shuttle Main Engine (SSME) test program was conducted between August 1995 and May 1996 using the Technology Test Bed (TTB) Engine. SSTO vehicle studies have indicated that increases in the propulsion system operating range can save significant weight and cost at the vehicle level. This test program demonstrated the ability of the SSME to accommodate a wide variation in safe operating ranges and therefore its applicability to the SSTO mission. A total of eight tests were completed with four at Marshall Space Flight Center's Advanced Engine Test Facility and four at the Stennis Space Center (SSC) A-2 attitude test stand. Key demonstration objectives were: 1) Mainstage operation at 5.4 to 6.9 mixture ratio; 2) Nominal engine start with significantly reduced engine inlet pressures of 50 psia LOX and 38 psia fuel; and 3) Low power level operation at 17%, 22%, 27%, 40%, 45%, and 50% of Rated Power Level. Use of the highly instrumented TTB engine for this test series has afforded the opportunity to study in great detail engine system operation not possible with a standard SSME and has significantly contributed to a greater understanding of the capabilities of the SSME and liquid rocket engines in general.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 14: An analysis of the technical communications practices reported by Israeli and US aerospace engineers and scientists

NASA Technical Reports Server (NTRS)

Barclay, Rebecca O.; Pinelli, Thomas E.; Elazar, David; Kennedy, John M.

1991-01-01

As part of Phase 4 of the NASA/DoD Aerospace Knowledge Diffusion Research Project, two pilot studies were conducted that investigated the technical communications practices of Israeli and U.S. aerospace engineers and scientists. Both studies had the same five objectives: first, to solicit the opinions of aerospace engineers and scientists regarding the importance of technical communications to their profession; second, to determine the use and production of technical communications by aerospace engineers and scientists; third, to seek their view about the appropriate content of an undergraduate course in technical communications; fourth, to determine aerospace engineers' and scientists' use of libraries, technical information centers, and on-line databases; and fifth, to determine the use and importance of computer and information technology to them. A self-administered questionnaire was mailed to randomly selected U.S. aerospace engineers and scientists who are working in cryogenics, adaptive walls, and magnetic suspension. A slightly modified version was sent to Israeli aerospace engineers and scientists working at Israel Aircraft Industries, LTD. Responses of the Israeli and U.S. aerospace engineers and scientists to selected questions are presented in this paper.

Choosing engineering: Can I succeed and do I want to? A qualitative analysis framed in expectancy-value theory

NASA Astrophysics Data System (ADS)

Matusovich, Holly Marie

Recently published reports call for an increase in the number of engineering graduates and suggest appropriate characteristics that these graduates should embody. Accomplishing either objective requires first understanding why students choose to pursue engineering degrees. This research started addressing this knowledge gap using Eccles' expectancy-value model to qualitatively and longitudinally examine undergraduate student's choices to enroll and persist in engineering majors. Specifically, this study focused on identity within Eccles' model to answer the question: How do students' beliefs about being engineers in the future shape their choices to pursue engineering? Framed in Eccles' model, students' choices to pursue engineering majors are based on beliefs about their engineering-related competence and how much they value succeeding in an engineering major. Eccles posits that identity shapes both competence and value beliefs. This study defined identity as students' self-perceptions as future engineers then examined the roles these self-perceptions in shaping their choices to pursue engineering degrees. Gee's conception of four-interrelated aspects of identity (nature identity, institutional identity, affinity identity, and discourse identity) provided a lens to examine students' self-perceptions as future engineers. Multiple case study methods guided this research with each of ten students (five men and five women) representing a case. Results derive from the inductive analysis of longitudinal interviews triangulated with survey results---all data spanned the students' first through fourth undergraduate years. This study is part of a larger body of work, the Academic Pathways Study (APS), conducted by the Center for Advancement of Engineering Education (CAEE). Results demonstrated that students' self-perceptions as future engineers are connected to both competence and value beliefs and to the choice to persist in engineering. Specifically, the results showed: (1) even in their fourth undergraduate year, three out of ten participants were uncertain about themselves as future engineers; (2) students choosing to pursue an engineering degree because they identify with the types of activities in which engineers engage experience the persistence choice process differently than students who choose engineering for other reasons; and (3) all students ultimately had positive competence beliefs, although two women participants continually renegotiated definitions of competence in engineering.

Preliminary flight test results of a fly-by-throttle emergency flight control system on an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. G.; Wells, Edward A.

1993-01-01

A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies have been followed by flight tests. This paper discusses the principles of throttles-only control, the F-15 airplane, the augmented system, and the flight results including landing approaches with throttles-only control to within 10 ft of the ground.

Performance potential of air turbo-ramjet employing supersonic through-flow fan

NASA Technical Reports Server (NTRS)

Kepler, C. E.; Champagne, G. A.

1989-01-01

A study was conducted to assess the performance potential of a supersonic through-flow fan in an advanced engine designed to power a Mach-5 cruise vehicle. It included a preliminary evaluation of fan performance requirements and the desirability of supersonic versus subsonic combustion, the design and performance of supersonic fans, and the conceptual design of a single-pass air-turbo-rocket/ramjet engine for a Mach 5 cruise vehicle. The study results showed that such an engine could provide high thrust over the entire speed range from sea-level takeoff to Mach 5 cruise, especially over the transonic speed range, and high fuel specific impulse at the Mach 5 cruise condition, with the fan windmilling.

Multiple case studies of STEM teachers' orientations to science teaching through engineering design

NASA Astrophysics Data System (ADS)

Rupp, Madeline

The following master's thesis is composed of two manuscripts describing STEM teachers' orientations to science teaching through engineering within the context of the Science Learning through Engineering Design (SLED) partnership. The framework guiding both studies was science teaching orientations, a component of pedagogical content knowledge. Data were collected via semi-structured interviews, multi-day classroom observations, pre- and post-observation interviews, implementation plans, and written reflections. Data sources were analyzed to generate two orientations to science teaching through engineering design for each participant. The first manuscript illustrates a single case study conducted with a sixth grade STEM teacher. Results of this study revealed a detailed picture of the teacher's goals, practices, assessments, and general views when teaching science through engineering design. Common themes across the teacher's instruction were used to characterize her orientations to science teaching through engineering design. Overall, the teacher's orientations showed a shift in her practice from didactic to student-centered methods of teaching as a result of integrating engineering design-based curriculum. The second manuscript describes a comparative case study of two sixth grade SLED participants. Results of this study revealed more complex and diverse relationships between the teachers' orientations to teaching science through engineering design and their instruction. Participants' orientations served as filters for instruction, guided by their divergent purposes for science teaching. Furthermore, their orientations and resulting implementation were developed from knowledge gained in teacher education, implying that teacher educators and researchers can use this framework to learn more about how teachers' knowledge is used to integrate engineering and science practices in the K-12 classroom.

Caribbean Engineer and Environmental Conference (CSL Issue Paper, Volume 14-08, November 2008)

DTIC Science & Technology

2008-11-01

Leadership, conducted a successful four day Engineer and Environment Conference between 2 and 5 September 2008 in San Jose , Puerto Rico. The purpose of...ANSI Std Z39-18 CONFERENCE SCHEDULE The Caribbean Engineer and Environmental Conference was conducted at the El San Juan Hotel in San Juan, Puerto...i.e. tsunamis, earthquakes, and volcanoes • Officials must develop ways to overcome communication problems between civil and military assets• Overall

An Exploratory Study of the United States Naval Academy Engineering Curriculum

DTIC Science & Technology

2007-06-01

research was conducted in an entirely quantitative fashion. There is a large amount of qualitative data that was not analyzed. These data are from the... qualitative assessment of the Naval Academy’s engineering program, and would be an excellent opportunity for future research . Overall, the results of...California: Sage Publications. Patton, M. Q. (1987). How to Use Qualitative Methods in Evaluation. California: Sage Publications. 89

Environmental Analysis

NASA Technical Reports Server (NTRS)

1980-01-01

Burns & McDonnell Engineering's environmental control study is assisted by NASA's Computer Software Management and Information Center's programs in environmental analyses. Company is engaged primarily in design of such facilities as electrical utilities, industrial plants, wastewater treatment systems, dams and reservoirs and aviation installations. Company also conducts environmental engineering analyses and advises clients as to the environmental considerations of a particular construction project. Company makes use of many COSMIC computer programs which have allowed substantial savings.

Development of CFD model for augmented core tripropellant rocket engine

NASA Astrophysics Data System (ADS)

Jones, Kenneth M.

1994-10-01

The Space Shuttle era has made major advances in technology and vehicle design to the point that the concept of a single-stage-to-orbit (SSTO) vehicle appears more feasible. NASA presently is conducting studies into the feasibility of certain advanced concept rocket engines that could be utilized in a SSTO vehicle. One such concept is a tripropellant system which burns kerosene and hydrogen initially and at altitude switches to hydrogen. This system will attain a larger mass fraction because LOX-kerosene engines have a greater average propellant density and greater thrust-to-weight ratio. This report describes the investigation to model the tripropellant augmented core engine. The physical aspects of the engine, the CFD code employed, and results of the numerical model for a single modular thruster are discussed.

Overview of the 1985 NASA Lewis Research Center SP-100 free-piston Stirling engine activities

NASA Technical Reports Server (NTRS)

Slaby, J.

1985-01-01

This effort is keyed on the design, fabrication, assembly, and testing of a 25 kWe Stirling space-power technology-feasibility demonstrator engine. Another facet of the SP-100 project covers the status of a 9000-hr endurance test conducted on a 2 kWe free-piston Stirling/linear alternator system employing hydrostatic gas bearings. Dynamic balancing of the RE-1000 engine (a 1 kWe free-piston Stirling engine) using a passive dynamic absorber will be discussed along with the results of a parametric study showing the relationships of Stirling power converter specific weight and efficiency as functions of Stirling engine heater to cooler temperature ratio. Planned tests will be described covering a hydrodynamic gas bearing concept for potential SP-100 application.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 39: The role of computer networks in aerospace engineering

NASA Technical Reports Server (NTRS)

Bishop, Ann P.; Pinelli, Thomas E.

1994-01-01

This paper presents selected results from an empirical investigation into the use of computer networks in aerospace engineering. Such networks allow aerospace engineers to communicate with people and access remote resources through electronic mail, file transfer, and remote log-in. The study drew its subjects from private sector, government and academic organizations in the U.S. aerospace industry. Data presented here were gathered in a mail survey, conducted in Spring 1993, that was distributed to aerospace engineers performing a wide variety of jobs. Results from the mail survey provide a snapshot of the current use of computer networks in the aerospace industry, suggest factors associated with the use of networks, and identify perceived impacts of networks on aerospace engineering work and communication.

The contribution of lubricant to the formation of particulate matter with reactivity controlled compression ignition in light-duty diesel engines

DOE PAGES

Storey, John Morse; Curran, Scott; Dempsey, Adam B.; ...

2014-12-25

Reactivity controlled compression ignition (RCCI) has been shown in single- and multi-cylinder engine research to achieve high thermal efficiencies with ultra-low NO X and soot emissions. The nature of the particulate matter (PM) produced by RCCI operation has been shown in recent research to be different than that of conventional diesel combustion and even diesel low-temperature combustion. Previous research has shown that the PM from RCCI operation contains a large amount of organic material that is volatile and semi-volatile. However, it is unclear if the organic compounds are stemming from fuel or lubricant oil. The PM emissions from dual-fuel RCCImore » were investigated in this study using two engine platforms, with an emphasis on the potential contribution of lubricant. Both engine platforms used the same base General Motors (GM) 1.9-L diesel engine geometry. The first study was conducted on a single-cylinder research engine with primary reference fuels (PRFs), n-heptane, and iso-octane. The second study was conducted on a four-cylinder GM 1.9-L ZDTH engine which was modified with a port fuel injection (PFI) system while maintaining the stock direct injection fuel system. Multi-cylinder RCCI experiments were run with PFI gasoline and direct injection of 2-ethylhexyl nitrate (EHN) mixed with gasoline at 5 % EHN by volume. In addition, comparison cases of conventional diesel combustion (CDC) were performed. Particulate size distributions were measured, and PM filter samples were collected for analysis of lube oil components. Triplicate PM filter samples (i.e., three individual filter samples) for both gas chromatography-mass spectroscopy (GC-MS; organic) analysis and X-ray fluorescence (XRF; metals) were obtained at each operating point and queued for analysis of both organic species and lubricant metals. Here, the results give a clear indication that lubricants do not contribute significantly to the formation of RCCI PM.« less

NEXT Ion Engine 2000 Hour Wear Test Results

NASA Technical Reports Server (NTRS)

Soulas, George C.; Kamhawi, Hani; Patterson, Michael J.; Britton, Melissa A.; Frandina, Michael M.

2004-01-01

The results of the NEXT 2000 h wear test are presented. This test was conducted with a 40 cm engineering model ion engine, designated EM1, at a 3.52 A beam current and 1800 V beam power supply voltage. Performance tests, which were conducted over a throttling range of 1.1 to 6.9 kW throughout the wear test, demonstrated that EM1 satisfied all thruster performance requirements. The ion engine accumulated 2038 h of operation at a thruster input power of 6.9 kW, processing 43 kg of xenon. Overall ion engine performance, which includes thrust, thruster input power, specific impulse, and thrust efficiency, was steady with no indications of performance degradation. The ion engine was also inspected following the test. This paper presents these findings.

Positioning of Engineer Ethics from the Standpoint of a Company. And the Ethics Education Towards Practice

NASA Astrophysics Data System (ADS)

Sato, Masaki

The purpose of a company is contribution to society by operating activities. Therefore, it has a company principle and “Business ethics” conduct codes in each. On the other hand, many engineers with specialties are performing business toward the same purpose at the same company. And it will produce new inconsistency by introducing “Engineer ethics” and “the ethics of each professional” all at once in the situation of that company. Then, the engineer ethics education in company needs to carry out by arranging company conduct codes and Engineer ethics. This paper proposes what the company ethics education should be from exemplifying results by make activities and engineer ethics education of the corporate ethics observance in the Tokyo Electric Power Co., Inc.

Study on the combustion process in a modern diesel engine controlled by pre-injection strategy

NASA Astrophysics Data System (ADS)

Punov, P.; Milkov, N.; Perilhon, C.; Podevin, P.; Evtimov, T.

2017-10-01

The paper aims to study the combustion process in a modern diesel engine over the engine operating map. In order to study the rate of heat release (ROHR), an automotive diesel engine was experimentally tested using the injection parameters factory defined. The experimental test was conducted over the engine operating map as the engine speed was limited to 2400 rpm. Then, an engine simulation model was developed in AVL Boost. By means of that model the ROHR was estimated and approximated by means of double Vibe function. In all engine operating points we found two peaks at the ROHR. The first is a result of the pilot injection as the second corresponds to the main injection. There was not found an overlap between both peaks. It was found that the first peak of ROHR occurs closely before top dead center (BTDC) at partial load than full load. The ROHR peak as a result of main injection begins from 4°BTDC to 18°ATDC. It starts earlier with increasing engine speed and load. The combustion duration varies from 30 ºCA to 70 °CA. In order to verify the results pressure curve was estimated by means of defined Vibe function parameters and combustion duration. As a result, we observed small deviation between measured and simulated pressure curves.

Busy test week

NASA Image and Video Library

2012-11-08

A test of NASA's liquid oxygen, liquid methane Project Morpheus engine is conducted Nov. 8 on the E-3 Test Stand at John C. Stennis Space Center. The test was one of 27 conducted in Stennis' E Test Complex the week of Nov. 5. Twenty-seven tests were conducted in a three-day period during the week, on three different rocket engines/components and on three E Complex test stands.

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis and computer science

NASA Technical Reports Server (NTRS)

1988-01-01

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis, and computer science during the period April l, 1988 through September 30, 1988.

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis and computer science

NASA Technical Reports Server (NTRS)

1987-01-01

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis, and computer science during the period October 1, 1986 through March 31, 1987 is summarized.

A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

NASA Technical Reports Server (NTRS)

Harris, Charles E.; Piascik, Robert S.; Newman, James C., Jr.

1999-01-01

An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

NASA Technical Reports Server (NTRS)

Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

2000-01-01

An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

A Rainbow View of NASA's RS-25 Engine Test

NASA Image and Video Library

2017-02-22

NASA engineers conducted their first RS-25 test of 2017 on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi, on Feb. 22, continuing to collect data on the performance of the rocket engine that will help power the new Space Launch System (SLS) rocket. Shown from the viewpoint of an overhead drone, the test of development engine No. 0528 ran the scheduled 380 seconds (six minutes and 20 seconds), allowing engineers to monitor various engine operating conditions. The test represents another step forward in development of the rocket that will launch humans aboard Orion deeper into space than ever before. Four RS-25 engines, together with a pair of solid rocket boosters, will power the SLS at launch on its deep-space missions. The engines for the first four SLS flights are former space shuttle main engines, which were tested extensively at Stennis and are some of the most proven engines in the world. Engineers are conducting an ongoing series of tests this year for SLS on both development and flight engines for future flights to ensure the engine, outfitted with a new controller, can perform at the higher level under a variety of conditions and situations. Stennis is also preparing its B-2 Test Stand to test the core stage for the first SLS flight with Orion, known as Exploration Mission-1. That testing will involve installing the flight stage on the stand and firing its four RS-25 engines simultaneously, just as during an actual launch. The Feb. 22 test was conducted by Aerojet Rocketdyne and Syncom Space Services engineers and operators. Aerojet Rocketdyne is the prime contractor for the RS-25 engines. Syncom Space Services is the prime contractor for Stennis facilities and operations. PAO Name:Kim Henry Phone Number:256-544-1899 Email Address: kimberly.m.henry@nasa.gov

Mach 5 to 7 RBCC Propulsion System Testing at NASA-LeRC HTF

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Thomas, Scott R.; Pack, William D.

1996-01-01

A series of Mach 5 to 7 freejet tests of a Rocket Based Combined Cycle (RBCC) engine were cnducted at the NASA Lewis Research Center (LERC) Hypersonic Tunnel Facility (HTF). This paper describes the configuration and operation of the HTF and the RBCC engine during these tests. A number of facility support systems are described which were added or modified to enhance the HTF test capability for conducting this experiment. The unfueled aerodynamic perfor- mance of the RBCC engine flowpath is also presented and compared to sub-scale test results previously obtained in the NASA LERC I x I Supersonic Wind Tunnel (SWT) and to Computational Fluid Dynamic (CFD) analysis results. This test program demonstrated a successful configuration of the HTF for facility starting and operation with a generic RBCC type engine and an increased range of facility operating conditions. The ability of sub-scale testing and CFD analysis to predict flowpath performance was also shown. The HTF is a freejet, blowdown propulsion test facility that can simulate up to Mach 7 flight conditions with true air composition. Mach 5, 6, and 7 facility nozzles are available, each with an exit diameter of 42 in. This combination of clean air, large scale, and Mach 7 capabilities is unique to the HTF. This RBCC engine study is the first engine test program conducted at the HTF since 1974.

Space shuttle orbit maneuvering engine, reusable thrust chamber program. Task 6: Data dump hot fuel element investigation

NASA Technical Reports Server (NTRS)

Nurick, W. H.

1974-01-01

An evaluation of reusable thrust chambers for the space shuttle orbit maneuvering engine was conducted. Tests were conducted using subscale injector hot-fire procedures for the injector configurations designed for a regenerative cooled engine. The effect of operating conditions and fuel temperature on combustion chamber performance was determined. Specific objectives of the evaluation were to examine the optimum like-doublet element geometry for operation at conditions consistent with a fuel regeneratively cooled engine (hot fuel, 200 to 250 F) and the sensitivity of the triplet injector element to hot fuels.

Video File - NASA Conducts 2nd RS-25 Engine Hot Fire of 2018 - 2018-02-01

NASA Image and Video Library

2018-02-01

NASA Conducts 2nd RS-25 Engine Hot Fire of 2018. A 365-second hot fire test on Feb. 1, 2018, at NASA’s Stennis Space Center in Mississippi marks the completion of “green run” testing, or flight certification, for all new RS-25 engine flight controllers slated for Exploration Mission-2, the first Space Launch System mission with astronauts on board. In addition to the flight controller, the Feb. 1 hot fire also marked the third test of a 3D printed pogo accumulator assembly for the RS-25 engine.

Experimental uncertainty and drag measurements in the national transonic facility

NASA Technical Reports Server (NTRS)

Batill, Stephen M.

1994-01-01

This report documents the results of a study which was conducted in order to establish a framework for the quantitative description of the uncertainty in measurements conducted in the National Transonic Facility (NTF). The importance of uncertainty analysis in both experiment planning and reporting results has grown significantly in the past few years. Various methodologies have been proposed and the engineering community appears to be 'converging' on certain accepted practices. The practical application of these methods to the complex wind tunnel testing environment at the NASA Langley Research Center was based upon terminology and methods established in the American National Standards Institute (ANSI) and the American Society of Mechanical Engineers (ASME) standards. The report overviews this methodology.

Chemical disorder as an engineering tool for spin polarization in Mn3Ga -based Heusler systems

NASA Astrophysics Data System (ADS)

Chadov, S.; D'Souza, S. W.; Wollmann, L.; Kiss, J.; Fecher, G. H.; Felser, C.

2015-03-01

Our study highlights spin-polarization mechanisms in metals by focusing on the mobilities of conducting electrons with different spins instead of their quantities. Here, we engineer electron mobility by applying chemical disorder induced by nonstoichiometric variations. As a practical example, we discuss the scheme that establishes such variations in tetragonal Mn3Ga Heusler material. We justify this approach using first-principles calculations of the spin-projected conductivity components based on the Kubo-Greenwood formalism. It follows that, in the majority of cases, even a small substitution of some other transition element instead of Mn may lead to a substantial increase in spin polarization along the tetragonal axis.

Preliminary summary of the ETF conceptual studies

NASA Technical Reports Server (NTRS)

Seikel, G. R.; Bercaw, R. W.; Pearson, C. V.; Owens, W. R.

1978-01-01

Power plant studies have shown the attractiveness of MHD topped steam power plants for baseload utility applications. To realize these advantages, a three-phase development program was initiated. In the first phase, the engineering data and experience were developed for the design and construction of a pilot plant, the Engineering Test Facility (ETF). Results of the ETF studies are reviewed. These three parallel independent studies were conducted by industrial teams led by the AVCO Everett Research Laboratory, the General Electric Corporation, and the Westinghouse Corporation. A preliminary analysis and the status of the critical evaluation of these results are presented.

Simulator study of vortex encounters by a twin-engine, commercial, jet transport airplane

NASA Technical Reports Server (NTRS)

Hastings, E. C., Jr.; Keyser, G. L., Jr.

1982-01-01

A simulator study of vortex encounters was conducted for a twin-engine, commercial, jet transport airplane encountering the vortex flow field of a heavy, four-engine, commercial, jet transport airplane in the final-approach configuration. The encounters were conducted with fixed controls and with a pilot using a state-of-the-art, manual-control system. Piloted encounters with the base-line vortex flow field out of ground effect (unattenuated) resulted in initial bank-angle excursions greater than 40 deg, coupled with initial sideslip-angle excursions greater than 10 deg. The severity of these initial upsets was significantly reduced when the vortex center was moved laterally or vertically away from the flight path of the encountering airplane. Smaller reductions occurred when the flow field was attenuated by the flight spoilers on the generating airplane. The largest reduction in the severity of the initial upsets, however, was from aging in ground effect. The severity of the initial upsets of the following airplane was relatively unaffected by the approach speed. Increasing the lift coefficient of the generating airplane resulted in an increase in the severity of the initial upsets.

Analysis of internal flows relative to the space shuttle main engine

NASA Technical Reports Server (NTRS)

1987-01-01

Cooperative efforts between the Lockheed-Huntsville Computational Mechanics Group and the NASA-MSFC Computational Fluid Dynamics staff has resulted in improved capabilities for numerically simulating incompressible flows generic to the Space Shuttle Main Engine (SSME). A well established and documented CFD code was obtained, modified, and applied to laminar and turbulent flows of the type occurring in the SSME Hot Gas Manifold. The INS3D code was installed on the NASA-MSFC CRAY-XMP computer system and is currently being used by NASA engineers. Studies to perform a transient analysis of the FPB were conducted. The COBRA/TRAC code is recommended for simulating the transient flow of oxygen into the LOX manifold. Property data for modifying the code to represent LOX/GOX flow was collected. The ALFA code was developed and recommended for representing the transient combustion in the preburner. These two codes will couple through the transient boundary conditions to simulate the startup and/or shutdown of the fuel preburner. A study, NAS8-37461, is currently being conducted to implement this modeling effort.

Static Performance of a Wing-Mounted Thrust Reverser Concept

NASA Technical Reports Server (NTRS)

Asbury, Scott C.; Yetter, Jeffrey A.

1998-01-01

An experimental investigation was conducted in the Jet-Exit Test Facility at NASA Langley Research Center to study the static aerodynamic performance of a wing-mounted thrust reverser concept applicable to subsonic transport aircraft. This innovative engine powered thrust reverser system is designed to utilize wing-mounted flow deflectors to produce aircraft deceleration forces. Testing was conducted using a 7.9%-scale exhaust system model with a fan-to-core bypass ratio of approximately 9.0, a supercritical left-hand wing section attached via a pylon, and wing-mounted flow deflectors attached to the wing section. Geometric variations of key design parameters investigated for the wing-mounted thrust reverser concept included flow deflector angle and chord length, deflector edge fences, and the yaw mount angle of the deflector system (normal to the engine centerline or parallel to the wing trailing edge). All tests were conducted with no external flow and high pressure air was used to simulate core and fan engine exhaust flows. Test results indicate that the wing-mounted thrust reverser concept can achieve overall thrust reverser effectiveness levels competitive with (parallel mount), or better than (normal mount) a conventional cascade thrust reverser system. By removing the thrust reverser system from the nacelle, the wing-mounted concept offers the nacelle designer more options for improving nacelle aero dynamics and propulsion-airframe integration, simplifying nacelle structural designs, reducing nacelle weight, and improving engine maintenance access.

Modification of hydraulic conductivity in granular soils using waste materials.

PubMed

Akbulut, S; Saglamer, A

2004-01-01

This paper evaluates the use of waste products such as silica fume and fly ash in modification of the granular soils in order to remove some environmental problems and create new useful findings in the field of engineering. It is known that silica fume and fly ash, as well as clay material, are used in geotechnical engineering because of their pozzolanic reactivity and fineness to improve the soil properties needed with respect to engineering purposes. The main objective of this research project was to investigate the use of these materials in geotechnical engineering and to improve the hydraulic properties of soils by means of grouting. For this reason, firstly, suitable grouts in suspension forms were prepared by using silica fume, fly ash, clay and cement in different percentages. The properties of these cement-based grouts were then determined to obtain the desired optimum values for grouting. After that, these grouts were penetrated into the soil samples under pressure. The experimental work indicates that these waste materials and clay improved the physical properties and the fluidity of the cement-based grouts and they also decreased the hydraulic conductivity of the grouted soil samples by sealing the voids of the soil. The results of this study have important findings concerning the use of these materials in soil treatment and the improvement of hydraulic conductivity of the soils.

New shipyard layout design for the preliminary phase & case study for the green field project

NASA Astrophysics Data System (ADS)

Song, Young Joo; Woo, Jong Hun

2013-03-01

For several decades, Asian nations such as Korea, Japan and China have been leading the shipbuilding industry since the decline in Europe and America. However, several developing countries such as India, Brazil, etc. are going to make an entrance into the shipbuilding industry. These developing countries are finding technical partners or information providers because they are in situation of little experiences and technologies. Now, the shipbuilding engineering companies of shipbuilding advanced countries are getting a chance of engineering business against those developing countries. The starting point of this business model is green field project for the construction of new shipyard. This business model is started with a design of the shipyard layout. For the conducting of the shipyard layout design, four kinds of engineering parts are required. Those are civil engineering, building engineering, utility engineering and production layout engineering. Among these parts, production layout engineering is most important because its result is the foundation of the other engineering parts and it determines the shipyard capacity during the shipyard operation lifecycle. Previous researches about the shipyard layout design are out of the range from the business requirements because most research cases are in the tower of ivory, which means that there are little consideration of real ship and shipbuilding operation. In this paper, a shipyard layout design for preliminary phase is conducted for the target of newly planned shipyard at Venezuela of South America with an integrated method that is capable of dealing with actual master data from the shipyard. The layout design method of this paper is differentiated from the previous researches in that the actual product data from the target ship and the actual shipbuilding operation data are used for the required area estimation.

Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

2012-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

40 CFR 86.096-24 - Test vehicles and engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... each engine listed in paragraphs (a)(3)(i) (A) through (G) of this section. (A) The bore and stroke. (B... conducted first. Within each combination, the engine that features the highest fuel feed per stroke... combinations, then one military engine is also selected. The engine with the highest fuel feed per stroke is...

Engineering Faculty Attitudes to General Chemistry Courses in Engineering Curricula

ERIC Educational Resources Information Center

Garip, Mehmet; Erdil, Erzat; Bilsel, Ayhan

2006-01-01

A survey on the attitudes of engineering faculty to chemistry, physics, and mathematics was conducted with the aim of clarifying the attitudes of engineering faculty to chemistry courses in relation to engineering education or curricula and assessing their expectations. The results confirm that on the whole chemistry is perceived as having a…

An Overview of the Literature: Research in P-12 Engineering Education

ERIC Educational Resources Information Center

Mendoza Díaz, Noemi V.; Cox, Monica F.

2012-01-01

This paper presents an extensive overview of preschool to 12th grade (P-12) engineering education literature published between 2001 and 2011. Searches were conducted through education and engineering library engines and databases as well as queries in established publications in engineering education. More than 50 publications were found,…

Engine classification using vibrations measured by Laser Doppler Vibrometer on different surfaces

NASA Astrophysics Data System (ADS)

Wei, J.; Liu, Chi-Him; Zhu, Zhigang; Vongsy, Karmon; Mendoza-Schrock, Olga

2015-05-01

In our previous studies, vehicle surfaces' vibrations caused by operating engines measured by Laser Doppler Vibrometer (LDV) have been effectively exploited in order to classify vehicles of different types, e.g., vans, 2-door sedans, 4-door sedans, trucks, and buses, as well as different types of engines, such as Inline-four engines, V-6 engines, 1-axle diesel engines, and 2-axle diesel engines. The results are achieved by employing methods based on an array of machine learning classifiers such as AdaBoost, random forests, neural network, and support vector machines. To achieve effective classification performance, we seek to find a more reliable approach to pick authentic vibrations of vehicle engines from a trustworthy surface. Compared with vibrations directly taken from the uncooperative vehicle surfaces that are rigidly connected to the engines, these vibrations are much weaker in magnitudes. In this work we conducted a systematic study on different types of objects. We tested different types of engines ranging from electric shavers, electric fans, and coffee machines among different surfaces such as a white board, cement wall, and steel case to investigate the characteristics of the LDV signals of these surfaces, in both the time and spectral domains. Preliminary results in engine classification using several machine learning algorithms point to the right direction on the choice of type of object surfaces to be planted for LDV measurements.

Rethinking the Systems Engineering Process in Light of Design Thinking

DTIC Science & Technology

2016-04-30

systems engineering process models (Blanchard & Fabrycky, 1990) and the majority of engineering design education (Dym et al., 2005). The waterfall model ...Engineering Career Competency Model Clifford Whitcomb, Systems Engineering Professor, NPS Corina White, Systems Engineering Research Associate, NPS...Postgraduate School (NPS) in Monterey, CA. He teaches and conducts research in the design of enterprise systems, systems modeling , and system

MEMS Micropropulsion Activities at JPL

NASA Technical Reports Server (NTRS)

Mueller, Juergen; Chakraborty, Indrani; Vargo, Stephen; Bame, David; Marrese, Colleen; Tang, William C.

1999-01-01

A status of MEMS-based micropropulsion activities conducted at JPL will be given. These activities include work conducted on the so called Vaporizing Liquid Micro-Thruster (VLM) which recently underwent proof-of-concept testing, demonstrating the ability to vaporize water propellant at 2 W and 2 V. Micro-ion engine technologies, such m field emitter arrays and micro-grids are being studied. Focus in the field emitter area is on arrays able to survive in thruster plumes and micro-ion engine plasmas to serve as neutralizers aW engine cathodes. Integrated, batch-fabricated Ion repeller grid structures are being studied as well as different emitter tip materials are being investigated to meet these goals. A micro-isolation valve is being studied to isolate microspacecraft feed system during long interplanetary cruises, avoiding leakage and prolonging lifetime and reliability of such systems. This concept relies on the melting of a thin silicon barrier. Burst pressure values as high as 2,900 psig were obtained for these valves and power requirements to melt barriers ranging between 10 - 50 microns in thickness, as determined through thermal finite element calculations, varied between 10 - 30 W to be applied over a duration of merely 0.5 ms.

Processing study of injection molding of silicon nitride for engine applications

NASA Technical Reports Server (NTRS)

Rorabaugh, M. E.; Yeh, H. C.

1985-01-01

The high hardness of silicon nitride, which is currently under consideration as a structural material for such hot engine components as turbine blades, renders machining of the material prohibitively costly; the near net shape forming technique of injection molding is accordingly favored as a means for component fabrication. Attention is presently given to the relationships between injection molding processing parameters and the resulting microstructural and mechanical properties of the resulting engine parts. An experimental program has been conducted under NASA sponsorship which tests the quality of injection molded bars of silicon nitride at various stages of processing.

ITE Trip Generation Modification Factors for Louisiana : Research Project Capsule

DOT National Transportation Integrated Search

2017-12-01

Using data from studies conducted in the United States over the last 50-60 years, the Institute of Transportation Engineers (ITE) has published trip generation rates for different land uses. Over time, observations from new studies have been incorpor...

PCC Airfield Pavement Response During Thaw-Weakening Periods: A Field Study

DOT National Transportation Integrated Search

1996-05-01

This investigation is part of the Cold Regions Research and Engineering Laboratory's (CRREL) on-going characterization of pavement performance in seasonal frost areas. As part of the research, CRREL conducted several field studies for the Federal Avi...

Effect of Surface Impulsive Thermal Loads on Fatigue Behavior of Constant Volume Propulsion Engine Combustor Materials

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Miller, Robert A.; Ghosn, Louis J.; Kalluri, Sreeramesh

2004-01-01

The development of advanced high performance constant-volume-combustion-cycle engines (CVCCE) requires robust design of the engine components that are capable of enduring harsh combustion environments under high frequency thermal and mechanical fatigue conditions. In this study, a simulated engine test rig has been established to evaluate thermal fatigue behavior of a candidate engine combustor material, Haynes 188, under superimposed CO2 laser surface impulsive thermal loads (30 to 100 Hz) in conjunction with the mechanical fatigue loads (10 Hz). The mechanical high cycle fatigue (HCF) testing of some laser pre-exposed specimens has also been conducted under a frequency of 100 Hz to determine the laser surface damage effect. The test results have indicated that material surface oxidation and creep-enhanced fatigue is an important mechanism for the surface crack initiation and propagation under the simulated CVCCE engine conditions.

Insights from industry: a quantitative analysis of engineers' perceptions of empathy and care within their practice

NASA Astrophysics Data System (ADS)

Hess, Justin L.; Strobel, Johannes; Pan, Rui Celia; Wachter Morris, Carrie A.

2017-11-01

This study focuses on two seldom-investigated skills or dispositions aligned with engineering habits of mind - empathy and care. In order to conduct quantitative research, we designed, explored the underlying structure of, validated, and tested the reliability of the Empathy and Care Questionnaire (ECQ), a new psychometric instrument. In the second part, we used the ECQ to explore the perceptions of empathy and care of alumni/ae of an internationally ranked US institution, along with how perceptions differed by work experience and gender. Results show that participants perceived empathy and care to be important in multiple respects, most notably in relational aspects of engineering practice. Engineers with more engineering experience were more likely to perceive empathy and care as existing in engineering practice and as important to their work. While these phenomena are sometimes depicted as feminine qualities, we found no gender differences among our respondents.

The two-stroke poppet valve engine. Part 2: Numerical investigations of intake and exhaust flow behaviour

NASA Astrophysics Data System (ADS)

Kamili Zahidi, M.; Razali Hanipah, M.

2017-10-01

A two-stroke poppet valve engine is developed to overcome the common problems in conventional two-stroke engine designs. However, replacing piston control port with poppet valve will resulted different flow behaviour. This paper presents the model and simulation result of three-dimensional (3D) port flow investigation of a two-stroke poppet valve engine. The objective of the investigation is to conduct a numerical investigation on port flow performance of two-stroke poppet valve engine and compare the results obtained from the experimental investigation. The model is to be used for the future numerical study of the engine. The volume flow rate results have been compared with the results obtained experimentally as presented in first part of this paper. The model has shown good agreement in terms of the flow rate at initial and final valve lifts but reduced by about 50% during half-lift region.

14 CFR 33.99 - General conduct of block tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block... is used for the endurance test it must be subjected to a calibration check before starting the...

14 CFR 33.99 - General conduct of block tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block... is used for the endurance test it must be subjected to a calibration check before starting the...

14 CFR 33.99 - General conduct of block tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block... is used for the endurance test it must be subjected to a calibration check before starting the...

14 CFR 33.99 - General conduct of block tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block... is used for the endurance test it must be subjected to a calibration check before starting the...

14 CFR 33.99 - General conduct of block tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block... is used for the endurance test it must be subjected to a calibration check before starting the...

Summary of research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis and computer science

NASA Technical Reports Server (NTRS)

1989-01-01

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis, and computer science during the period October 1, 1988 through March 31, 1989 is summarized.

Engineering the thermal conductivity along an individual silicon nanowire by selective helium ion irradiation.

PubMed

Zhao, Yunshan; Liu, Dan; Chen, Jie; Zhu, Liyan; Belianinov, Alex; Ovchinnikova, Olga S; Unocic, Raymond R; Burch, Matthew J; Kim, Songkil; Hao, Hanfang; Pickard, Daniel S; Li, Baowen; Thong, John T L

2017-06-27

The ability to engineer the thermal conductivity of materials allows us to control the flow of heat and derive novel functionalities such as thermal rectification, thermal switching and thermal cloaking. While this could be achieved by making use of composites and metamaterials at bulk length-scales, engineering the thermal conductivity at micro- and nano-scale dimensions is considerably more challenging. In this work, we show that the local thermal conductivity along a single Si nanowire can be tuned to a desired value (between crystalline and amorphous limits) with high spatial resolution through selective helium ion irradiation with a well-controlled dose. The underlying mechanism is understood through molecular dynamics simulations and quantitative phonon-defect scattering rate analysis, where the behaviour of thermal conductivity with dose is attributed to the accumulation and agglomeration of scattering centres at lower doses. Beyond a threshold dose, a crystalline-amorphous transition was observed.

Engineering the thermal conductivity along an individual silicon nanowire by selective helium ion irradiation

PubMed Central

Zhao, Yunshan; Liu, Dan; Chen, Jie; Zhu, Liyan; Belianinov, Alex; Ovchinnikova, Olga S.; Unocic, Raymond R.; Burch, Matthew J.; Kim, Songkil; Hao, Hanfang; Pickard, Daniel S.; Li, Baowen; Thong, John T. L.

2017-01-01

The ability to engineer the thermal conductivity of materials allows us to control the flow of heat and derive novel functionalities such as thermal rectification, thermal switching and thermal cloaking. While this could be achieved by making use of composites and metamaterials at bulk length-scales, engineering the thermal conductivity at micro- and nano-scale dimensions is considerably more challenging. In this work, we show that the local thermal conductivity along a single Si nanowire can be tuned to a desired value (between crystalline and amorphous limits) with high spatial resolution through selective helium ion irradiation with a well-controlled dose. The underlying mechanism is understood through molecular dynamics simulations and quantitative phonon-defect scattering rate analysis, where the behaviour of thermal conductivity with dose is attributed to the accumulation and agglomeration of scattering centres at lower doses. Beyond a threshold dose, a crystalline-amorphous transition was observed. PMID:28653663

Engineering the thermal conductivity along an individual silicon nanowire by selective helium ion irradiation

DOE PAGES

Zhao, Yunshan; Liu, Dan; Chen, Jie; ...

2017-06-27

The ability to engineer the thermal conductivity of materials allows us to control the flow of heat and derive novel functionalities such as thermal rectification, thermal switching and thermal cloaking. While this could be achieved by making use of composites and metamaterials at bulk length-scales, engineering the thermal conductivity at micro- and nano-scale dimensions is considerably more challenging. Here, we show that the local thermal conductivity along a single Si nanowire can be tuned to a desired value (between crystalline and amorphous limits) with high spatial resolution through selective helium ion irradiation with a well-controlled dose. The underlying mechanism ismore » understood through molecular dynamics simulations and quantitative phonon-defect scattering rate analysis, where the behaviour of thermal conductivity with dose is attributed to the accumulation and agglomeration of scattering centres at lower doses. Finally, we observed threshold dose beyond a crystalline-amorphous transition.« less

Engineering the thermal conductivity along an individual silicon nanowire by selective helium ion irradiation

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

Zhao, Yunshan; Liu, Dan; Chen, Jie

The ability to engineer the thermal conductivity of materials allows us to control the flow of heat and derive novel functionalities such as thermal rectification, thermal switching and thermal cloaking. While this could be achieved by making use of composites and metamaterials at bulk length-scales, engineering the thermal conductivity at micro- and nano-scale dimensions is considerably more challenging. Here, we show that the local thermal conductivity along a single Si nanowire can be tuned to a desired value (between crystalline and amorphous limits) with high spatial resolution through selective helium ion irradiation with a well-controlled dose. The underlying mechanism ismore » understood through molecular dynamics simulations and quantitative phonon-defect scattering rate analysis, where the behaviour of thermal conductivity with dose is attributed to the accumulation and agglomeration of scattering centres at lower doses. Finally, we observed threshold dose beyond a crystalline-amorphous transition.« less

Pretreatment Engineering Platform Phase 1 Final Test Report

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

Kurath, Dean E.; Hanson, Brady D.; Minette, Michael J.

2009-12-23

Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project, Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to conduct testing to demonstrate the performance of the WTP Pretreatment Facility (PTF) leaching and ultrafiltration processes at an engineering-scale. In addition to the demonstration, the testing was to address specific technical issues identified in Issue Response Plan for Implementation of External Flowsheet Review Team (EFRT) Recommendations - M12, Undemonstrated Leaching Processes.( ) Testing was conducted in a 1/4.5-scale mock-up of the PTF ultrafiltration system, the Pretreatment Engineering Platform (PEP). Parallel laboratory testing wasmore » conducted in various PNNL laboratories to allow direct comparison of process performance at an engineering-scale and a laboratory-scale. This report presents and discusses the results of those tests.« less

Exploring the relationship between time management skills and the academic achievement of African engineering students - a case study

NASA Astrophysics Data System (ADS)

Swart, Arthur James; Lombard, Kobus; de Jager, Henk

2010-03-01

Poor academic success by African engineering students is currently experienced in many higher educational institutions, contributing to lower financial subsidies by local governments. One of the contributing factors to this low academic success may be the poor time management skills of these students. This article endeavours to explore this relationship by means of a theoretical literature review and an empirical study. Numerous studies have been conducted in this regard, but with mixed results. The case study of this article involves a design module termed Design Projects III, where the empirical study incorporated an ex post facto study involving a pre-experimental/exploratory design using descriptive statistics. The results of this study were applied to various tests, which indicated no statistically significant relationship between time management skills and the academic achievement of African engineering students.

Understanding the leaky engineering pipeline: Motivation and job adaptability of female engineers

NASA Astrophysics Data System (ADS)

Saraswathiamma, Manjusha Thekkedathu

This dissertation is a mixed-method study conducted using qualitative grounded theory and quantitative survey and correlation approaches. This study aims to explore the motivation and adaptability of females in the engineering profession and to develop a theoretical framework for both motivation and adaptability issues. As a result, this study endeavors to design solutions for the low enrollment and attenuation of female engineers in the engineering profession, often referred to as the "leaky female engineering pipeline." Profiles of 123 female engineers were studied for the qualitative approach, and 98 completed survey responses were analyzed for the quantitative approach. The qualitative, grounded-theory approach applied the constant comparison method; open, axial, and selective coding was used to classify the information in categories, sub-categories, and themes for both motivation and adaptability. The emergent themes for decisions motivating female enrollment include cognitive, emotional, and environmental factors. The themes identified for adaptability include the seven job adaptability factors: job satisfaction, risk- taking attitude, career/skill development, family, gender stereotyping, interpersonal skills, and personal benefit, as well as the self-perceived job adaptability factor. Illeris' Three-dimensional Learning Theory was modified as a model for decisions motivating female enrollment. This study suggests a firsthand conceptual parallelism of McClusky's Theory of Margin for the adaptability of female engineers in the profession. Also, this study attempted to design a survey instrument to measure job adaptability of female engineers. The study identifies two factors that are significantly related to job adaptability: interpersonal skills (< p = 0.01) and family (< p = 0.05); gender stereotyping and personal benefit are other factors that are also significantly (< p = 0.1) related.

Advanced Low-Cost O2/H2 Engines for the SSTO Application

NASA Technical Reports Server (NTRS)

Goracke, B. David; Levack, Daniel J. H.; Nixon, Robert F.

1994-01-01

The recent NASA Access to Space study examined future Earth to orbit (ETO) transportation needs and fleets out to 2030. The baseline in the option 3 assessment was a single stage to orbit (SSTO) vehicle. A study was conducted to assess the use of new advanced low cost O2/H2 engines for this SSTO application. The study defined baseline configurations and ground rules and defined six engine cycles to explore engine performance. The cycles included an open cycle, and a series of closed cycles with varying abilities to extract energy from the propellants to power he turbomachinery. The cycles thus varied in the maximum chamber pressure they could reach and in their weights at any given chamber pressure. The weight of each cycle was calculated for two technology levels versus chamber pressure up to the power limit of the cycle. The performance in the SSTO mission was then modeled using the resulting engine weights and specific impulse performance using the Access to Space option 3 vehicle. The results showed that new O2/H2 engines are viable and competitive candidates for the SSTO application using chamber pressures of 4,000 psi.

Design, analysis, and control of a large transport aircraft utilizing selective engine thrust as a backup system for the primary flight control. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Gerren, Donna S.

1995-01-01

A study has been conducted to determine the capability to control a very large transport airplane with engine thrust. This study consisted of the design of an 800-passenger airplane with a range of 5000 nautical miles design and evaluation of a flight control system, and design and piloted simulation evaluation of a thrust-only backup flight control system. Location of the four wing-mounted engines was varied to optimize the propulsive control capability, and the time constant of the engine response was studied. The goal was to provide level 1 flying qualities. The engine location and engine time constant did not have a large effect on the control capability. The airplane design did meet level 1 flying qualities based on frequencies, damping ratios, and time constants in the longitudinal and lateral-directional modes. Project pilots consistently rated the flying qualities as either level 1 or level 2 based on Cooper-Harper ratings. However, because of the limited control forces and moments, the airplane design fell short of meeting the time required to achieve a 30 deg bank and the time required to respond a control input.

Experimental Investigations on Diesel engine using Methyl esters of Jatropha oil and fish oil

NASA Astrophysics Data System (ADS)

Karthikeyan, A.; Jayaprabakar, J.; Dude Williams, Richard

2017-05-01

The aim of the study is to use fish oil methyl ester (FME) and Jatropha oil methyl ester (JME) as a substitute for diesel in compression ignition engine. Experiments were conducted when the engine was fuelled with Diesel, Fish oil methyl ester and Jatropha oil methyl ester. The experiment covered a range of loads. An AVL smoke meter was used to measure the smoke density in HSU (Hatridge Smoke Unit). The exhaust emissions were measured using exhaust gas analyzer. High volume sampler was employed to measure the particulate matter in exhaust. The performance of the engine was evaluated in terms of brake specific fuel consumption, brake thermal efficiency. The combustion characteristics of the engine were studied in terms of cylinder pressure with respect to crank angle. The emissions of the engine were studied in terms of concentration of CO, NOx, particulate matter and smoke density. The results obtained for Fish oil methyl ester, Jatropha oil methyl ester, were compared with the results of diesel. Bio-diesel, which can be used as an alternate diesel fuel, is made from vegetable oil and animal fats. It is renewable, non-toxic and possesses low emission profiles.

Race, class and gender in engineering education: A quantitative investigation of first year enrollment

NASA Astrophysics Data System (ADS)

Phillips, Canek Moises Luna

Research explanations for the disparity across both race and gender in engineering education has typically relied on a deficit model, whereby women and people of color lack the requisite knowledge or psychological characteristics that Whites and men have to become engineers in sufficient numbers. Instead of using a deficit model approach to explain gender and race disparity, in the three studies conducted for this dissertation, I approach gender and race disparity as the result of processes of segregation linked to the historic and on-going perpetuation of systemic sources of oppression in the United States. In the first study, I investigate the relationship between the odds ratios of women and men enrolled in first year US engineering programs and institutional characteristics. To do this, I employ linear regression to study data from the American Society of Engineering Education (ASEE) and the National Center for Education Statistics (NCES) to quantify relationships between odds ratios and institutional characteristics. Results of the linear regression models showed significant relationships between the cost of universities and university selectivity and the odds ratios of women choosing engineering. I theorize how the results could be related to the operation of occupational segregation in engineering, particularly how class-based markers have been historically used by women to overcome gender-based segregation in engineering. In the second study, I examine longitudinal patterns of race, gender, and intersectional combinations of race and gender in enrollments of students in first year engineering programs across the United States (US). Using enrollment data from the American Society of Engineering Education and California Post-Secondary Education Commission, I construct measures of segregation to study how trends in the disparity of students by race could be related to increases in public school segregation nationally over the past 25 years. I found that as public school segregation levels increased nationally, underrepresentation of Black and Hispanics and overrepresentation of White and Asian students has moved further toward the extremes in first year engineering programs compared to these groups’ shares of high school enrollment. I conclude that the study of public school segregation and its effect on racial disparity needs greater attention, as well as that the investigation I conducted serves as a beginning towards pushing back on deficit model explanations of race and gender disparity in engineering. In the third study, I return to the investigation of odds ratios and institutional characteristics, constructing odds ratios using ASEE and NCES data based on the odds of enrollment in first year engineering programs between Asian, Black, and Hispanic students compared to White students. I again quantify the relationships between odds ratios and institutional characteristics using linear regression models and discuss results using theory based in the perspective of occupational segregation. In this case, results were inconclusive leading me to conclude that other variables that I did not consider, such as the segregation levels of schools that students come from before enrollment, should be considered as I develop my own future study into the topic.

Boundary Engineering for the Thermoelectric Performance of Bulk Alloys Based on Bismuth Telluride.

PubMed

Mun, Hyeona; Choi, Soon-Mok; Lee, Kyu Hyoung; Kim, Sung Wng

2015-07-20

Thermoelectrics, which transports heat for refrigeration or converts heat into electricity directly, is a key technology for renewable energy harvesting and solid-state refrigeration. Despite its importance, the widespread use of thermoelectric devices is constrained because of the low efficiency of thermoelectric bulk alloys. However, boundary engineering has been demonstrated as one of the most effective ways to enhance the thermoelectric performance of conventional thermoelectric materials such as Bi2 Te3 , PbTe, and SiGe alloys because their thermal and electronic transport properties can be manipulated separately by this approach. We review our recent progress on the enhancement of the thermoelectric figure of merit through boundary engineering together with the processing technologies for boundary engineering developed most recently using Bi2 Te3 -based bulk alloys. A brief discussion of the principles and current status of boundary-engineered bulk alloys for the enhancement of the thermoelectric figure of merit is presented. We focus mainly on (1) the reduction of the thermal conductivity by grain boundary engineering and (2) the reduction of thermal conductivity without deterioration of the electrical conductivity by phase boundary engineering. We also discuss the next potential approach using two boundary engineering strategies for a breakthrough in the area of bulk thermoelectric alloys. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

How Middle Schoolers Draw Engineers and Scientists

NASA Astrophysics Data System (ADS)

Fralick, Bethany; Kearn, Jennifer; Thompson, Stephen; Lyons, Jed

2009-02-01

The perceptions young students have of engineers and scientists are often populated with misconceptions and stereotypes. Although the perceptions that young people have of engineers and of scientists have been investigated separately, they have not been systematically compared. The research reported in this paper explores the question "How are student perceptions of engineers and scientists similar and how are they different?" Approximately 1,600 middle school students from urban and suburban schools in the southeastern United States were asked to draw either an engineer or a scientist at work. Drawings included space for the students to explain what their person was doing in the picture. A checklist to code the drawings was developed and used by two raters. This paper discusses similarities and differences in middle school perceptions of scientists and engineers. Results reveal that the students involved in this study frequently perceive scientists as working indoors conducting experiments. A large fraction of the students have no perception of engineering. Others frequently perceive engineers as working outdoors in manual labor. The findings have implications for the development and implementation of engineering outreach efforts.

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination

PubMed Central

Shepard, Michele; Brenner, Sara

2014-01-01

Background: Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. Objectives: The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Methods: Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Results: Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Conclusions: Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace. PMID:25000112

Research in progress in applied mathematics, numerical analysis, and computer science

NASA Technical Reports Server (NTRS)

1990-01-01

Research conducted at the Institute in Science and Engineering in applied mathematics, numerical analysis, and computer science is summarized. The Institute conducts unclassified basic research in applied mathematics in order to extend and improve problem solving capabilities in science and engineering, particularly in aeronautics and space.

[Research Conducted at the Institute for Computer Applications in Science and Engineering for the Period October 1, 1999 through March 31, 2000

NASA Technical Reports Server (NTRS)

Bushnell, Dennis M. (Technical Monitor)

2000-01-01

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, computer science, fluid mechanics, and structures and materials during the period October 1, 1999 through March 31, 2000.

Progress with variable cycle engines

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.

1980-01-01

The evaluation of components of an advanced propulsion system for a future supersonic cruise vehicle is discussed. These components, a high performance duct burner for thrust augmentation and a low jet noise coannular exhaust nozzle, are part of the variable stream control engine. An experimental test program involving both isolated component and complete engine tests was conducted for the high performance, low emissions duct burner with excellent results. Nozzle model tests were completed which substantiate the inherent jet noise benefit associated with the unique velocity profile possible of a coannular exhaust nozzle system on a variable stream control engine. Additional nozzle model performance tests have established high thrust efficiency levels at takeoff and supersonic cruise for this nozzle system. Large scale testing of these two critical components is conducted using an F100 engine as the testbed for simulating the variable stream control engine.

Methods for comparative evaluation of propulsion system designs for supersonic aircraft

NASA Technical Reports Server (NTRS)

Tyson, R. M.; Mairs, R. Y.; Halferty, F. D., Jr.; Moore, B. E.; Chaloff, D.; Knudsen, A. W.

1976-01-01

The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses.

77 FR 21311 - Locomotive Safety Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-09

... brake maintenance are based on this extensive history of study and testing. Over the last several... Working Group discussions, FRA conducted a study to determine the average temperature in each type of locomotive cab commonly used at the time. The study concluded that at the location where the engineer...

An evaluation of the 10:30 centerline marking pattern.

DOT National Transportation Integrated Search

1977-01-01

In response to Value Engineering Proposal #M-26, a study of the feasibility of adopting a 10 ft. mark 30 ft. gap centerline pattern for use on 2- and 4-lane rural roads was conducted. The study included a literature review, field studies of traffic s...

Oxidation Behavior of Copper Alloy Candidates for Rocket Engine Applications (Technical Poster)

NASA Technical Reports Server (NTRS)

Ogbuji, Linus U. J.; Humphrey, Donald H.; Barrett, Charles A.; Greenbauer-Seng, Leslie (Technical Monitor); Gray, Hugh R. (Technical Monitor)

2002-01-01

A rocket engine's combustion chamber is lined with material that is highly conductive to heat in order to dissipate the huge thermal load (evident in a white-hot exhaust plume). Because of its thermal conductivity copper is the best choice of liner material. However, the mechanical properties of pure copper are inadequate to withstand the high stresses, hence, copper alloys are needed in this application. But copper and its alloys are prone to oxidation and related damage, especially "blanching" (an oxidation-reduction mode of degradation). The space shuttle main engine combustion chamber is lined with a Cu-Ag-Zr alloy, "NARloy-Z", which exhibits blanching. A superior liner is being sought for the next generation of RLVs (Reusable Launch Vehicles) It should have improved mechanical properties and higher resistance to oxidation and blanching, but without substantial penalty in thermal conductivity. GRCop84, a Cu-8Cr-4Nb alloy (Cr2Nb in Cu matrix), developed by NASA Glenn Research Center (GRC) and Case Western Reserve University, is a prime contender for RLV liner material. In this study, the oxidation resistance of GRCop-84 and other related/candidate copper alloys are investigated and compared

NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 15: Technical uncertainty and project complexity as correlates of information use by US industry-affiliated aerospace engineers and scientists: Results of an exploratory investigation

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Glassman, Nanci A.; Affelder, Linda O.; Hecht, Laura M.; Kennedy, John M.; Barclay, Rebecca O.

1993-01-01

An exploratory study was conducted that investigated the influence of technical uncertainty and project complexity on information use by U.S. industry-affiliated aerospace engineers and scientists. The study utilized survey research in the form of a self-administered mail questionnaire. U.S. aerospace engineers and scientists on the Society of Automotive Engineers (SAE) mailing list served as the study population. The adjusted response rate was 67 percent. The survey instrument is appendix C to this report. Statistically significant relationships were found to exist between technical uncertainty, project complexity, and information use. Statistically significant relationships were found to exist between technical uncertainty, project complexity, and the use of federally funded aerospace R&D. The results of this investigation are relevant to researchers investigating information-seeking behavior of aerospace engineers. They are also relevant to R&D managers and policy planners concerned with transferring the results of federally funded aerospace R&D to the U.S. aerospace industry.

A preliminary design and analysis of an advanced heat-rejection system for an extreme altitude advanced variable cycle diesel engine installed in a high-altitude advanced research platform

NASA Technical Reports Server (NTRS)

Johnston, Richard P.

1992-01-01

Satellite surveillance in such areas as the Antarctic indicates that from time to time concentration of ozone grows and shrinks. An effort to obtain useful atmospheric data for determining the causes of ozone depletion would require a flight capable of reaching altitudes of at least 100,000 ft and flying subsonically during the sampling portion of the mission. A study of a heat rejection system for an advanced variable cycle diesel (AVCD) engine was conducted. The engine was installed in an extreme altitude, high altitude advanced research platform. Results indicate that the waste heat from an AVCD engine propulsion system can be rejected at the maximum cruise altitude of 120,000 ft. Fifteen performance points, reflecting the behavior of the engine as the vehicle proceeded through the mission, were used to characterize the heat exchanger operation. That portion of the study is described in a appendix titled, 'A Detailed Study of the Heat Rejection System for an Extreme Altitude Atmospheric Sampling Aircraft,' by a consultant, Mr. James Bourne, Lytron, Incorporated.

EVALUATION OF CARBON DIOXIDE CAPTURE FROM EXISTING COAL FIRED PLANTS BY HYBRID SORPTION USING SOLID SORBENTS

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

Benson, Steven; Palo, Daniel; Srinivasachar, Srivats

2014-12-01

Under contract DE-FE0007603, the University of North Dakota conducted the project Evaluation of Carbon Dioxide Capture from Existing Coal Fired Plants by Hybrid Sorption Using Solid Sorbents. As an important element of this effort, an Environmental Health and Safety (EH&S) Assessment was conducted by Barr Engineering Co. (Barr) in association with the University of North Dakota. The assessment addressed air and particulate emissions as well as solid and liquid waste streams. The magnitude of the emissions and waste streams was estimated for evaluation purposes. EH&S characteristics of materials used in the system are also described. This document contains data basedmore » on the mass balances from both the 40 kJ/mol CO2 and 80 kJ/mol CO2 desorption energy cases evaluated in the Final Technical and Economic Feasibility study also conducted by Barr Engineering.« less

Powder-Derived High-Conductivity Coatings for Copper Alloys

NASA Technical Reports Server (NTRS)

Thomas-Ogbuji, Linus U.

2003-01-01

Makers of high-thermal-flux engines prefer copper alloys as combustion chamber liners, owing to a need to maximize heat dissipation. Since engine environments are strongly oxidizing in nature and copper alloys generally have inadequate resistance to oxidation, the liners need coatings for thermal and environmental protection; however, coatings must be chosen with great care in order to avoid significant impairment of thermal conductivity. Powder-derived chromia- and alumina- forming alloys are being studied under NASA's programs for advanced reusable launch vehicles to succeed the space shuttle fleet. NiCrAlY and Cu-Cr compositions optimized for high thermal conductivity have been tested for static and cyclic oxidation, and for susceptibility to blanching - a mode of degradation arising from oxidation-reduction cycling. The results indicate that the decision to coat the liners or not, and which coating/composition to use, depends strongly on the specific oxidative degradation mode that prevails under service conditions.

Study of Technological Improvements in Automobile Fuel Consumption : Volume 3B. Appendixes 4 though 7.

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

PARTICLE SPECIATION AND EMISSION PROFILES OF SMALL 2-STROKE ENGINES

EPA Science Inventory

The Human Exposure and Atmospheric Sciences Division (HEASD) conducts studies designed to acquire information from emission sources for use in source apportionment studies. The objective of this work is to characterize a complete, speciated emission profile (PM and air toxics) ...

Study of Technological Improvements in Automobile Fuel Consumption : Volume 3A. Appendixes 1 through 3

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

A preliminary investigation on the effects of characteristics and contractual behaviour on civil engineering project performance

NASA Astrophysics Data System (ADS)

Ismail, W. N. W.; Adnan, H.; Yusuwan, N.; Maisham, M.; Hassan, A. A.

2018-02-01

The significant role of civil engineering project is not only to make the lives of people easier and secure but also to trigger the economic growth by providing infrastructure facilities as well as job opportunities. As it is dominantly initiated by government sectors, performance of the civil engineering projects is always observed. This study aims to investigate the characteristics of civil engineering project and the contractual behavior of the key participants and how do these two factors affect civil engineering projects performance. Literature reviews, content analysis and questionnaires survey were conducted to undertake the research. A total of 50 questionnaires were distributed and 10 questionnaires were returned, resulting in a 20% response rate. The research unveiled that performance of civil engineering projects are influenced greatly by the ability to handle the unpredictable character of the civil engineering projects and adequate behavioral management. Apart from that, balancing the factors with high quality of workmanship, avoidance or well managed conflicts and high satisfaction level will ensure performance in projects.

Clinician search behaviors may be influenced by search engine design.

PubMed

Lau, Annie Y S; Coiera, Enrico; Zrimec, Tatjana; Compton, Paul

2010-06-30

Searching the Web for documents using information retrieval systems plays an important part in clinicians' practice of evidence-based medicine. While much research focuses on the design of methods to retrieve documents, there has been little examination of the way different search engine capabilities influence clinician search behaviors. Previous studies have shown that use of task-based search engines allows for faster searches with no loss of decision accuracy compared with resource-based engines. We hypothesized that changes in search behaviors may explain these differences. In all, 75 clinicians (44 doctors and 31 clinical nurse consultants) were randomized to use either a resource-based or a task-based version of a clinical information retrieval system to answer questions about 8 clinical scenarios in a controlled setting in a university computer laboratory. Clinicians using the resource-based system could select 1 of 6 resources, such as PubMed; clinicians using the task-based system could select 1 of 6 clinical tasks, such as diagnosis. Clinicians in both systems could reformulate search queries. System logs unobtrusively capturing clinicians' interactions with the systems were coded and analyzed for clinicians' search actions and query reformulation strategies. The most frequent search action of clinicians using the resource-based system was to explore a new resource with the same query, that is, these clinicians exhibited a "breadth-first" search behaviour. Of 1398 search actions, clinicians using the resource-based system conducted 401 (28.7%, 95% confidence interval [CI] 26.37-31.11) in this way. In contrast, the majority of clinicians using the task-based system exhibited a "depth-first" search behavior in which they reformulated query keywords while keeping to the same task profiles. Of 585 search actions conducted by clinicians using the task-based system, 379 (64.8%, 95% CI 60.83-68.55) were conducted in this way. This study provides evidence that different search engine designs are associated with different user search behaviors.

Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

2004-01-01

The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30,60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized information from psychological and medical testing, data on the knowledge, experience and skills of the applicants, and team building exercises. The design, development, buildup and operation of test hardware and documentation followed the established NASA processes and requirements for test buildup and operation.

Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

2006-01-01

The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30, 60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized information from psychological and medical testing, data on the knowledge, experience and skills of the applicants, and team building exercises. The design, development, buildup and operation of test hardware and documentation followed the established NASA processes and requirements for test buildup and operation.

The Effect of Valve Timing Upon the Performance of a Supercharged Engine at Altitude and an Unsupercharged Engine at Sea Level

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Biermann, Arnold E

1932-01-01

This investigation was conducted to determine the comparative effects of valve timing on the performance of an unsupercharged engine at sea level and a supercharged engine at altitude. The tests were conducted on the NACA universal test engine. The timing of the four valve events was varied over a wide range; the engine speeds were varied between 1,050 and 1,500 r.p.m.; the compression ratios were varied between 4.35:1 and 7.35:1. The conditions of exhaust pressure and carburetor pressure of a supercharged engine were simulated for altitudes between 0 and 18,000 feet. The results show that optimum valve timing for a supercharged engine at an altitude of 18,000 feet differs slightly from that for an unsupercharged engine at sea level. A small increase in power is obtained by using the optimum timing for 18,000 feet for altitudes above 5,000 feet. The timing of the intake opening and exhaust closing becomes more critical as the compression ratio is increased.

Application of a Sensemaking Approach to Ethics Training in the Physical Sciences and Engineering

NASA Astrophysics Data System (ADS)

Kligyte, Vykinta; Marcy, Richard T.; Waples, Ethan P.; Sevier, Sydney T.; Godfrey, Elaine S.; Mumford, Michael D.; Hougen, Dean F.

2008-06-01

Integrity is a critical determinant of the effectiveness of research organizations in terms of producing high quality research and educating the new generation of scientists. A number of responsible conduct of research (RCR) training programs have been developed to address this growing organizational concern. However, in spite of a significant body of research in ethics training, it is still unknown which approach has the highest potential to enhance researchers' integrity. One of the approaches showing some promise in improving researchers' integrity has focused on the development of ethical decision-making skills. The current effort proposes a novel curriculum that focuses on broad metacognitive reasoning strategies researchers use when making sense of day-to-day social and professional practices that have ethical implications for the physical sciences and engineering. This sensemaking training has been implemented in a professional sample of scientists conducting research in electrical engineering, atmospheric and computer sciences at a large multi-cultural, multi-disciplinary, and multi-university research center. A pre-post design was used to assess training effectiveness using scenario-based ethical decision-making measures. The training resulted in enhanced ethical decision-making of researchers in relation to four ethical conduct areas, namely data management, study conduct, professional practices, and business practices. In addition, sensemaking training led to researchers' preference for decisions involving the application of the broad metacognitive reasoning strategies. Individual trainee and training characteristics were used to explain the study findings. Broad implications of the findings for ethics training development, implementation, and evaluation in the sciences are discussed.

Application of a sensemaking approach to ethics training in the physical sciences and engineering.

PubMed

Kligyte, Vykinta; Marcy, Richard T; Waples, Ethan P; Sevier, Sydney T; Godfrey, Elaine S; Mumford, Michael D; Hougen, Dean F

2008-06-01

Integrity is a critical determinant of the effectiveness of research organizations in terms of producing high quality research and educating the new generation of scientists. A number of responsible conduct of research (RCR) training programs have been developed to address this growing organizational concern. However, in spite of a significant body of research in ethics training, it is still unknown which approach has the highest potential to enhance researchers' integrity. One of the approaches showing some promise in improving researchers' integrity has focused on the development of ethical decision-making skills. The current effort proposes a novel curriculum that focuses on broad metacognitive reasoning strategies researchers use when making sense of day-to-day social and professional practices that have ethical implications for the physical sciences and engineering. This sensemaking training has been implemented in a professional sample of scientists conducting research in electrical engineering, atmospheric and computer sciences at a large multi-cultural, multi-disciplinary, and multi-university research center. A pre-post design was used to assess training effectiveness using scenario-based ethical decision-making measures. The training resulted in enhanced ethical decision-making of researchers in relation to four ethical conduct areas, namely data management, study conduct, professional practices, and business practices. In addition, sensemaking training led to researchers' preference for decisions involving the application of the broad metacognitive reasoning strategies. Individual trainee and training characteristics were used to explain the study findings. Broad implications of the findings for ethics training development, implementation, and evaluation in the sciences are discussed.

Advanced space engine powerhead breadboard assembly system study

NASA Technical Reports Server (NTRS)

Campbell, R. G.

1978-01-01

The objective of this study was to establish a preliminary design of a Powerhead Breadboard Assembly (PBA) for an 88 964-Newton (20,000-pound) thrust oxygen/hydrogen staged combustion cycle engine for use in orbital transfer vehicle propulsion. Existing turbopump, preburner, and thrust chamber components were integrated with interconnecting ducting, a heat exchanger, and a control system to complete the PBA design. Cycle studies were conducted to define starting transients and steady-state balances for the completed design. Specifications were developed for all valve applications and the conditions required for the control system integration with the facility for system test were defined.

Pneumatic injection system using a hot exhaust gases, developed in Institute of Automobiles and Internal Combustion Engines of Cracow University of Technology

NASA Astrophysics Data System (ADS)

Marek, W.; Śliwiński, K.

2016-09-01

The article concerns research carried out by the Krakow University of Technology on the concept of a pneumatic fuel injection spark ignition engines. In this artkule an example of an application of this type of power to the Wankel's engine, together with a description of its design and operating principles and the benefits of its use. The work was carried out over many years by Prof. Stanislaw Jarnuszkiewicz despite the development of many patents but not widely used in engines. Authors who were involved in the team-work of the team of Prof. Jarnuszkiewicz, after conducting exploratory studies, believed that this solution has development potential and this will be presented in future articles.

Deep sequencing methods for protein engineering and design.

PubMed

Wrenbeck, Emily E; Faber, Matthew S; Whitehead, Timothy A

2017-08-01

The advent of next-generation sequencing (NGS) has revolutionized protein science, and the development of complementary methods enabling NGS-driven protein engineering have followed. In general, these experiments address the functional consequences of thousands of protein variants in a massively parallel manner using genotype-phenotype linked high-throughput functional screens followed by DNA counting via deep sequencing. We highlight the use of information rich datasets to engineer protein molecular recognition. Examples include the creation of multiple dual-affinity Fabs targeting structurally dissimilar epitopes and engineering of a broad germline-targeted anti-HIV-1 immunogen. Additionally, we highlight the generation of enzyme fitness landscapes for conducting fundamental studies of protein behavior and evolution. We conclude with discussion of technological advances. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Joyce, R.J.; Natusch, D.F.S.; Richardson, D.W.

Blends of 15% methanol with petrol containing 1% isobutanol have been utilised by 45 vehicles operated for a period of two years. An additional 907 vehicles have been operated for approximately one year to obtain information about the distribution of M15 blends, about necessary co-solvent concentrations, and about general vehicle driveability. Initial studies have also been conducted using 15-20% emulsions of methanol with diesel in diesel-cycle engines. High methanol fuels ranging from M85 to M100 have been tested in six purpose-built vehicles and 45 retrofitted vehicles involving four different types of retrofit systems. In addition, high methanol fuels have alsomore » been tested in dieselcycle engines involving two different types of purpose-built engines, together with unmodified engines.« less

AJ26 engine test

NASA Image and Video Library

2010-12-17

John C. Stennis Space Center engineers conduct a 55-second test fire of Aerojet's liquid-fuel AJ26 rocket engine that will power the first stage of Orbital Sciences Corporation's Taurus II space launch vehicle. The Dec. 17, 2010 test was conducted on the E-1 Test Stand at Stennis in support of NASA's Commercial Transportation Services partnerships to enable commercial cargo flights to the International Space Station. Orbital is under contract with NASA to provide eight cargo missions to the space station through 2015.

Development and Evaluation of a Prototype Wheeled Ultra-High Pressure Extinguisher System with Novec 1230

DTIC Science & Technology

2016-01-01

Fire Tests Pool fire tests were conducted as outlined below, and consisted of a pretest phase, in which the F-100 engine nacelle was first...the nacelle during the test phase. Pretest Phase  Determine and record extinguisher full weight.  Initiate flow of jet fuel through the...extinguisher after test. 3.4.2. Rear Engine Fire Tests Rear engine fire tests were conducted as outlined below, and consisted of a pretest phase

Building an experience factory for maintenance

NASA Technical Reports Server (NTRS)

Valett, Jon D.; Condon, Steven E.; Briand, Lionel; Kim, Yong-Mi; Basili, Victor R.

1994-01-01

This paper reports the preliminary results of a study of the software maintenance process in the Flight Dynamics Division (FDD) of the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC). This study is being conducted by the Software Engineering Laboratory (SEL), a research organization sponsored by the Software Engineering Branch of the FDD, which investigates the effectiveness of software engineering technologies when applied to the development of applications software. This software maintenance study began in October 1993 and is being conducted using the Quality Improvement Paradigm (QIP), a process improvement strategy based on three iterative steps: understanding, assessing, and packaging. The preliminary results represent the outcome of the understanding phase, during which SEL researchers characterized the maintenance environment, product, and process. Findings indicate that a combination of quantitative and qualitative analysis is effective for studying the software maintenance process, that additional measures should be collected for maintenance (as opposed to new development), and that characteristics such as effort, error rate, and productivity are best considered on a 'release' basis rather than on a project basis. The research thus far has documented some basic differences between new development and software maintenance. It lays the foundation for further application of the QIP to investigate means of improving the maintenance process and product in the FDD.

Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

PubMed Central

Grau, Francisco; Choo, Hyunwook; Hu, Jong Wan; Jung, Jongwon

2015-01-01

Biomasses are organic materials that are derived from any living or recently-living structure. Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes. Thus, recycling or treatment of biomass ashes leads to utilizing the natural materials as an economical and environmental alternative. This study is intended to provide an environmental solution for uncontrolled disposal of biomass ashes by way of recycling the biomass ash and replacing the soils in geotechnical engineering projects. Therefore, in this study, characteristic tests of wood and sugarcane bagasse ashes that are considered the most common biomass ashes are conducted. The test of chemical compositions of biomass ashes is conducted using energy dispersive X-ray spectroscopy (EDS), and Scanning Electron Microscope (SEM), and heavy metal analysis is also conducted. Engineering behaviors including hydraulic conductivity, constrained modulus and shear modulus are examined. Also, coal fly ash Class C is used in this study for comparison with biomass ashes, and Ottawa 20/30 sands containing biomass ashes are examined to identify the soil replacement effect of biomass ashes. The results show that the particle sizes of biomass ashes are halfway between coal fly ash Class C and Ottawa 20/30 sand, and biomass ashes consist of a heterogeneous mixture of different particle sizes and shapes. Also, all heavy metal concentrations were found to be below the US Environmental Protection Agency (EPA) maximum limit. Hydraulic conductivity values of Ottawa 20/30 sand decrease significantly when replacing them with only 1%–2% of biomass ashes. While both the constrained modulus and shear modulus of biomass ashes are lower than Ottawa 20/30 sand, those of mixtures containing up to 10% biomass ashes are little affected by replacing the soils with biomass ashes. PMID:28793611

Installation for the catalytic afterburning of exhaust gases of a multi-cylinder internal combustion engine

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

Lange, K.

1974-04-24

An installation for the catalytic afterburning of exhaust gases of a multi-cylinder internal combustion engine has two cylinder rows with two exhaust gas lines, each of which includes at least one catalyst. A temperature-responsive control is operable during engine start-up to conduct substantially the entire exhaust gas flow from the internal combustion engine during warmup for a predetermined time by way of only one of the two catalyst and then, after a short period of time, to conduct the exhaust gas flow from each row of cylinders by way of its associated gas line and catalyst.

J-2X engine

NASA Image and Video Library

2012-05-16

On May 16, 2012, engineers at Stennis Space Center conducted a test of the next-generation J-2X engine that will help power NASA's new Space Launch System, moving NASA even closer to a return to deep space.

A Review of Evidence-Based Traffic Engineering Measures Designed to Reduce Pedestrian–Motor Vehicle Crashes

PubMed Central

Retting, Richard A.; Ferguson, Susan A.; McCartt, Anne T.

2003-01-01

We provide a brief critical review and assessment of engineering modifications to the built environment that can reduce the risk of pedestrian injuries. In our review, we used the Transportation Research Information Services database to conduct a search for studies on engineering countermeasures documented in the scientific literature. We classified countermeasures into 3 categories—speed control, separation of pedestrians from vehicles, and measures that increase the visibility and conspicuity of pedestrians. We determined the measures and settings with the greatest potential for crash prevention. Our review, which emphasized inclusion of studies with adequate methodological designs, showed that modification of the built environment can substantially reduce the risk of pedestrian–vehicle crashes. PMID:12948963

Studies on combined model based on functional objectives of large scale complex engineering

NASA Astrophysics Data System (ADS)

Yuting, Wang; Jingchun, Feng; Jiabao, Sun

2018-03-01

As various functions were included in large scale complex engineering, and each function would be conducted with completion of one or more projects, combined projects affecting their functions should be located. Based on the types of project portfolio, the relationship of projects and their functional objectives were analyzed. On that premise, portfolio projects-technics based on their functional objectives were introduced, then we studied and raised the principles of portfolio projects-technics based on the functional objectives of projects. In addition, The processes of combined projects were also constructed. With the help of portfolio projects-technics based on the functional objectives of projects, our research findings laid a good foundation for management of large scale complex engineering portfolio management.

Pulse Detonation Rocket Engine Research at NASA Marshall

NASA Technical Reports Server (NTRS)

Morris, Christopher I.

2003-01-01

This viewgraph representation provides an overview of research being conducted on Pulse Detonation Rocket Engines (PDRE) by the Propulsion Research Center (PRC) at the Marshall Space Flight Center. PDREs have a theoretical thermodynamic advantage over Steady-State Rocket Engines (SSREs) although unsteady blowdown processes complicate effective use of this advantage in practice; PRE is engaged in a fundamental study of PDRE gas dynamics to improve understanding of performance issues. Topics covered include: simplified PDRE cycle, comparison of PDRE and SSRE performance, numerical modeling of quasi 1-D rocket flows, time-accurate thrust calculations, finite-rate chemistry effects in nozzles, effect of F-R chemistry on specific impulse, effect of F-R chemistry on exit species mole fractions and PDRE performance optimization studies.

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

NASA Technical Reports Server (NTRS)

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

1977-01-01

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

Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment.

PubMed

Lee, Ben H; Santoni, Gregory W; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Zahniser, Mark S; Wofsy, Steven C; Munger, J William

2011-09-15

The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

Strain gage system evaluation program

NASA Technical Reports Server (NTRS)

Dolleris, G. W.; Mazur, H. J.; Kokoszka, E., Jr.

1978-01-01

A program was conducted to determine the reliability of various strain gage systems when applied to rotating compressor blades in an aircraft gas turbine engine. A survey of current technology strain gage systems was conducted to provide a basis for selecting candidate systems for evaluation. Testing and evaluation was conducted in an F 100 engine. Sixty strain gage systems of seven different designs were installed on the first and third stages of an F 100 engine fan. Nineteen strain gage failures occurred during 62 hours of engine operation, for a survival rate of 68 percent. Of the failures, 16 occurred at blade-to-disk leadwire jumps (84 percent), two at a leadwire splice (11 percent), and one at a gage splice (5 percent). Effects of erosion, temperature, G-loading, and stress levels are discussed. Results of a post-test analysis of the individual components of each strain gage system are presented.

40 CFR 35.2114 - Value engineering.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

40 CFR 35.2114 - Value engineering.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

40 CFR 35.2114 - Value engineering.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering Research...

40 CFR 35.2114 - Value engineering.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

AJ26 engine test

NASA Image and Video Library

2011-11-17

A team of engineers at Stennis Space Center conducted a test firing of an Aerojet AJ26 flight engine Nov. 17, providing continued support to Orbital Sciences Corporation as it prepares to launch commercial cargo missions to the International Space Station. AJ26 engines will power Orbital's Taurus II rocket on the missions.

34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 2 2012-07-01 2012-07-01 false What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering Research...

34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 2 2013-07-01 2013-07-01 false What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering Research...

34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering Research...

40 CFR 35.2114 - Value engineering.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 2 2014-07-01 2013-07-01 true What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering Research...

Examining Elementary School Students' Transfer of Learning through Engineering Design Using Think-Aloud Protocol Analysis

ERIC Educational Resources Information Center

Kelley, Todd; Sung, Euisuk

2017-01-01

The introduction of engineering practices within the "Next Generation Science Standards" provides technology educators with opportunities to help STEM educators infuse engineering design within a core curriculum. The introduction of teaching engineering design in early elementary grades also provides opportunities to conduct research…

Best Manufacturing Practices: Report of Survey Conducted at Texas Instruments Defense Systems and Electronics Group, Dallas, Texas

DTIC Science & Technology

1988-06-01

Washington, DC Richard Celin Naval Air Engineering Center (201) 323-2173 Lakehurst, NJ Alice Giampapa TRIAD Engineering Co., Inc. Administrative (609) 939...7 3.1 DESIGN DESIGN PROCESS Producibility Engineering ........................................................ 7 Producibility Advisor... Engineers in Manufacturing Processes ........................... 21 Method Improvement Report Program

Small Engine Component Technology (SECT) studies

NASA Technical Reports Server (NTRS)

Meyer, P. K.; Harbour, L.

1986-01-01

A study was conducted to identify component technology requirements for small, expendable gas turbine engines that would result in substantial improvements in performance and cost by the year 2000. A subsonic, 2600 nautical mile (4815 km) strategic cruise missile mission was selected for study. A baseline (state-of-the-art) engine and missile configuration were defined to evaluate the advanced technology engines. Two advanced technology engines were configured and evaluated using advanced component efficiencies and ceramic composite materials; a 22:1 overall pressure ratio, 3.85 bypass ratio twin-spool turbofan; and an 8:1 overall pressure, 3.66 bypass ratio, single-spool recuperated turbofan with 0.85 recuperator effectiveness. Results of mission analysis indicated a reduction in fuel burn of 38 and 47 percent compared to the baseline engine when using the advanced turbofan and recuperated turbofan, respectively. While use of either advanced engine resulted in approximately a 25 percent reduction in missile size, the unit life cycle (LCC) cost reduction of 56 percent for the advanced turbofan relative to the baseline engine gave it a decisive advantage over the recuperated turbofan with 47 percent LCC reduction. An additional range improvement of 10 percent results when using a 56 percent loaded carbon slurry fuel with either engine. These results can be realized only if significant progress is attained in the fields of solid lubricated bearings, small aerodynamic component performance, composite ceramic materials and integration of slurry fuels. A technology plan outlining prospective programs in these fields is presented.

Air traffic control system baseline methodology guide.

DOT National Transportation Integrated Search

1999-06-01

The Air Traffic Control System Baseline Methodology Guide serves as a reference in the design and conduct of baseline studies. : Engineering research psychologists are the intended audience for the Methodology Guide, which focuses primarily on techni...

HAARP diesel engine-generator(s) noise study

DOT National Transportation Integrated Search

2005-01-07

This document presents the results and corresponding analysis of an outdoor noise measurement program conducted by the John A. Volpe National Transportation Systems Centers Acoustic Facility (Volpe Center) at the United States Air Forces High F...

CDI Sensitivity and Crosstrack Error on Nonprecision Approaches

DOT National Transportation Integrated Search

1991-01-01

This study was conducted to determine the influence of course deviation : indicator (CDI) sensitivity on pilot tracking error during nonprecision approaches. : Twelve pilots flew an instrumented single-engine airplane on 144 approaches at six : diffe...

Evaluation of LED vehicular and pedestrian modules.

DOT National Transportation Integrated Search

2009-04-01

This study was conducted to verify the compliance of vehicular and pedestrian LED traffic signal modules with the Institute : of Transportation Engineers specifications; and to assess drivers preferences of the LED modules. Four vehicular modules ...

Determining Studies Conducted upon Individuals with Autism Spectrum Disorder Using High-Tech Devices

ERIC Educational Resources Information Center

Eliçin, Özge; Kaya, Ali

2017-01-01

This study explores 67 experimental research articles written about children with Autism Spectrum Disorder using high-tech devices. The studies in this research were accessed through EBSCO, Academic Search Complete, ERIC, and Uludag University online search engines using keywords such as "autism and technology", "autism and…

Active Control of Fan Noise-Feasibility Study. Volume 1; Flyover System Noise Studies

NASA Technical Reports Server (NTRS)

Kraft, Robert E.; Janardan, B. A.; Kontos, G. C.; Gliebe, P. R.

1994-01-01

A study has been completed to examine the potential reduction of aircraft flyover noise by the method of active noise control (ANC). It is assumed that the ANC system will be designed such that it cancels discrete tones radiating from the engine fan inlet or fan exhaust duct. Thus, without considering the engineering details of the ANC system design, tone levels are arbitrarily removed from the engine component noise spectrum and the flyover noise EPNL levels are compared with and without the presence of tones. The study was conducted for a range of engine cycles, corresponding to fan pressure ratios from 1.3 to 1.75. The major conclusions that can be drawn are that, for a fan pressure ratio of 1.75, ANC of tones gives about the same suppression as acoustic treatment without ANC, and for a fan pressure ratio of 1.45, ANC appears to offer less effectiveness than passive treatment. Additionally, ANC appears to be more effective at sideline and cutback conditions than at approach. Overall EPNL suppressions due to tone removal range from about 1 to 3 dB at takeoff engine speeds and from 1 to 5 db at approach speeds. Studies of economic impact of the installation of an ANC system for the four engine cases indicate increases of DOC ranging from 1 to 2 percent, favoring the lower fan pressure ratio engines. Further study is needed to confirm the results by examining additional engine data, particularly at low fan pressure ratios, and studying the details of the current results to obtain a more complete understanding. Further studies should also include determining the effects of combining passive and active treatment.

Undergraduate Research in Physics as a course for Engineering and Computer Science Majors

NASA Astrophysics Data System (ADS)

O'Brien, James; Rueckert, Franz; Sirokman, Greg

2017-01-01

Undergraduate research has become more and more integral to the functioning of higher educational institutions. At many institutions undergraduate research is conducted as capstone projects in the pure sciences, however, science faculty at some schools (including that of the authors) face the challenge of not having science majors. Even at these institutions, a select population of high achieving engineering students will often express a keen interest in conducting pure science research. Since a foray into science research provides the student the full exposure to the scientific method and scientific collaboration, the experience can be quite rewarding and beneficial to the development of the student as a professional. To this end, the authors have been working to find new contexts in which to offer research experiences to non- science majors, including a new undergraduate research class conducted by physics and chemistry faculty. An added benefit is that these courses are inherently interdisciplinary. Students in the engineering and computer science fields step into physics and chemistry labs to solve science problems, often invoking their own relevant expertise. In this paper we start by discussing the common themes and outcomes of the course. We then discuss three particular projects that were conducted with engineering students and focus on how the undergraduate research experience enhanced their already rigorous engineering curriculum.

Using Engine Thrust for Emergency Flight Control: MD-11 and B-747 Results

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Maine, Trindel A.; Burken, John J.; Bull, John

1998-01-01

With modern digital control systems, using engine thrust for emergency flight control to supplement or replace failed aircraft normal flight controls has become a practical consideration. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control. An F-15 and an MD-11 airplane have been landed without using any flight control surfaces. Preliminary studies have also been conducted that show that engines on only one wing can provide some flight control capability if the lateral center of gravity can be shifted toward the side of the airplane that has the operating engine(s). Simulator tests of several airplanes with no flight control surfaces operating and all engines out on the left wing have all shown positive control capability within the available range of lateral center-of-gravity offset. Propulsion-controlled aircraft systems that can operate without modifications to engine control systems, thus allowing PCA technology to be installed on less capable airplanes or at low cost, are also desirable. Further studies have examined simplified 'PCA Lite' and 'PCA Ultralite' concepts in which thrust control is provided by existing systems such as auto-throttles or a combination of existing systems and manual pilot control.

[Tissue engineering of urinary bladder using acellular matrix].

PubMed

Glybochko, P V; Olefir, Yu V; Alyaev, Yu G; Butnaru, D V; Bezrukov, E A; Chaplenko, A A; Zharikova, T M

2017-04-01

Tissue engineering has become a new promising strategy for repairing damaged organs of the urinary system, including the bladder. The basic idea of tissue engineering is to integrate cellular technology and advanced bio-compatible materials to replace or repair tissues and organs. of the study is the objective reflection of the current trends and advances in tissue engineering of the bladder using acellular matrix through a systematic search of preclinical and clinical studies of interest. Relevant studies, including those on methods of tissue engineering of urinary bladder, was retrieved from multiple databases, including Scopus, Web of Science, PubMed, Embase. The reference lists of the retrieved review articles were analyzed for the presence of the missing relevant publications. In addition, a manual search for registered clinical trials was conducted in clinicaltrials.gov. Following the above search strategy, a total of 77 eligible studies were selected for further analysis. Studies differed in the types of animal models, supporting structures, cells and growth factors. Among those, studies using cell-free matrix were selected for a more detailed analysis. Partial restoration of urothelium layer was observed in most studies where acellular grafts were used for cystoplasty, but no the growth of the muscle layer was observed. This is the main reason why cellular structures are more commonly used in clinical practice.

76 FR 72004 - Request for Comments on the Intent To Conduct an Evaluation of the Scientists and Engineers...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

... NATIONAL SCIENCE FOUNDATION Request for Comments on the Intent To Conduct an Evaluation of the Scientists and Engineers Statistical Data System (SESTAT) AGENCY: National Science Foundation. ACTION: Notice of availability. SUMMARY: This notice announces the intent of the National Center for Science and...

Ecosystem Consequences of Contrasting Flow Regimes in an Urban Effects Stream Mesocosm Study

EPA Science Inventory

A stream mesocosm experiment was conducted to study the ecosystem-wide effects of two replicated flow hydrograph treatments programmed in an attempt to compare a simulated predevelopment condition to the theoretical changes that new development brings, while accounting for engine...

Turbojet engine blade damping

NASA Technical Reports Server (NTRS)

Srinivasan, A. V.; Cutts, D. G.; Sridhar, S.

1981-01-01

The potentials of various sources of nonaerodynamic damping in engine blading are evaluated through a combination of advanced analysis and testing. The sources studied include material hysteresis, dry friction at shroud and root disk interfaces as well as at platform type external dampers. A limited seris of tests was conducted to evaluate damping capacities of composite materials (B/AL, B/AL/Ti) and thermal barrier coatings. Further, basic experiments were performed on titanium specimens to establish the characteristics of sliding friction and to determine material damping constants J and n. All the tests were conducted on single blades. Mathematical models were develthe several mechanisms of damping. Procedures to apply this data to predict damping levels in an assembly of blades are developed and discussed.

Airflow and thrust calibration of an F100 engine, S/N P680059, at selected flight conditions

NASA Technical Reports Server (NTRS)

Biesiadny, T. J.; Lee, D.; Rodriguez, J. R.

1978-01-01

An airflow and thrust calibration of an F100 engine, S/N P680059, was conducted to study airframe propulsion system integration losses in turbofan-powered high-performance aircraft. The tests were conducted with and without thrust augmentation for a variety of simulated flight conditions with emphasis on the transonic regime. The resulting corrected airflow data generalized into one curve with corrected fan speed while corrected gross thrust increased as simulated flight conditions increased. Overall agreement between measured data and computed results was 1 percent for corrected airflow and -1 1/2 percent for gross thrust. The results of an uncertainty analysis are presented for both parameters at each simulated flight condition.