14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...
14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...
14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...
14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...
14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-26
..., engineering or design work and purchasing existing facilities or right-of-way. 3. Livability: Increasing... Feasibility: The technical feasibility of the project should be demonstrated by engineering and design studies and activities; the development of design criteria and/or a basis of design; the basis for the cost...
Case Study: Developing Graduate Engineers at Kentz Engineers & Constructors
ERIC Educational Resources Information Center
O'Donnell, Hugh; Karallis, Takis; Sandelands, Eric; Cassin, James; O'Neill, Donal
2008-01-01
Purpose: The aim of this paper is to outline the approach and process in place within Kentz Engineers & Constructors to develop graduate engineers on an international basis. Design/methodology/approach: The approach adopted is that of a case study which describes activities and processes within the organization and the rationale behind them,…
Makarov, A V; Arutyunyan, I V; Bol'shakova, G B; Volkov, A V; Gol'dshtein, D V
2009-10-01
We studied morphological changes in the paraurethral area of Wistar rats after introduction of tissue engineering constructs on the basis of multipotent mesenchymal stem cells and gelatin sponge. The tissue engineering construct containing autologous culture of the stromal fraction of the adipose tissue was most effective. After introduction of this construct we observed more rapid degradation of the construct matrix and more intensive formation of collagen fibers.
Real-time Simulation of Turboprop Engine Control System
NASA Astrophysics Data System (ADS)
Sheng, Hanlin; Zhang, Tianhong; Zhang, Yi
2017-05-01
On account of the complexity of turboprop engine control system, real-time simulation is the technology, under the prerequisite of maintaining real-time, to effectively reduce development cost, shorten development cycle and avert testing risks. The paper takes RT-LAB as a platform and studies the real-time digital simulation of turboprop engine control system. The architecture, work principles and external interfaces of RT-LAB real-time simulation platform are introduced firstly. Then based on a turboprop engine model, the control laws of propeller control loop and fuel control loop are studied. From that and on the basis of Matlab/Simulink, an integrated controller is designed which can realize the entire process control of the engine from start-up to maximum power till stop. At the end, on the basis of RT-LAB platform, the real-time digital simulation of the designed control system is studied, different regulating plans are tried and more ideal control effects have been obtained.
NASA Astrophysics Data System (ADS)
Kayumov, A. T.; Mustafina, D. N.
2014-12-01
In this research work an attempt is made to reveal the factors and level of engineering and working professions prestige in the minds of studying youth on the basis of empiric data. The results of research allow revealing the mechanism of social-professional selfidentification of school-aged youth, on the basis of which an opportunity to study in a new way traditional system of profession-oriented work appears.
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.
THERMODYNAMICS USED IN ENVIRONMENTAL ENGINEERING
Thermodynamics is a science in which energy transformations are studied as well as their relationships to the changes in the chemical properties of a system. It is the fundamental basis of many engineering fields. The profession of environmental engineering is no exception. In pa...
Engineer's Needs for Scientific and Technical Information.
ERIC Educational Resources Information Center
David, A., Ed.; And Others
This study has as its main object the formulation of an approach, as global and comprehensive as possible, to the multiple aspects of the engineer's needs for scientific and technical information. The basis of the study is an analysis of the engineer's role, its characteristics, different specialties, levels of training, and categories of…
NASA Technical Reports Server (NTRS)
Bair, E. K.
1986-01-01
The System Trades Study and Design Methodology Plan is used to conduct trade studies to define the combination of Space Shuttle Main Engine features that will optimize candidate engine configurations. This is accomplished by using vehicle sensitivities and engine parametric data to establish engine chamber pressure and area ratio design points for candidate engine configurations. Engineering analyses are to be conducted to refine and optimize the candidate configurations at their design points. The optimized engine data and characteristics are then evaluated and compared against other candidates being considered. The Evaluation Criteria Plan is then used to compare and rank the optimized engine configurations on the basis of cost.
49 CFR 195.452 - Pipeline integrity management in high consequence areas.
Code of Federal Regulations, 2011 CFR
2011-10-01
... engineering evaluation and provides an equivalent level of public safety and environmental protection. (c... situations—(i) Engineering basis. An operator may be able to justify an engineering basis for a longer assessment interval on a segment of line pipe. The justification must be supported by a reliable engineering...
ERIC Educational Resources Information Center
Alkandari, Nabila Y.
2014-01-01
The main goal of this research is to gain an understanding of the challenges which have to be confronted by the engineering students at the College of Engineering and Petroleum at Kuwait University. The college has a large number of students, of which three hundred and eighty five were selected on a random basis for study purposes. The results…
Performance of NACA Eight-Stage Axial-Flow Compressor Designed on the Basis of Airfoil Theory
1944-08-01
TEE BASIS OF AIRFOIL THEORY By John T. Slnnette, Jr., Oscar W. Schey, and J. Austin King Aircraft Engine Research Laboratory Cleveland, Ohio FILE...efficiency can he designed by the proper application of airfoil theory. Aircraft Engine Research laboratory, Hational Advisory Committee for Aeronautlos...Basis of Airfoil Theory AUTHORS): Sinnette, John T.; Schey, Oscar W.; and others ORIGINATING AGENCY: Aircraft Engine Research Laboratory, Cleveland
Variable Cycle Engine Technology Program Planning and Definition Study
NASA Technical Reports Server (NTRS)
Westmoreland, J. S.; Stern, A. M.
1978-01-01
The variable stream control engine, VSCE-502B, was selected as the base engine, with the inverted flow engine concept selected as a backup. Critical component technologies were identified, and technology programs were formulated. Several engine configurations were defined on a preliminary basis to serve as demonstration vehicles for the various technologies. The different configurations present compromises in cost, technical risk, and technology return. Plans for possible variably cycle engine technology programs were formulated by synthesizing the technology requirements with the different demonstrator configurations.
Wave rotor demonstrator engine assessment
NASA Technical Reports Server (NTRS)
Snyder, Philip H.
1996-01-01
The objective of the program was to determine a wave rotor demonstrator engine concept using the Allison 250 series engine. The results of the NASA LERC wave rotor effort were used as a basis for the wave rotor design. A wave rotor topped gas turbine engine was identified which incorporates five basic requirements of a successful demonstrator engine. Predicted performance maps of the wave rotor cycle were used along with maps of existing gas turbine hardware in a design point study. The effects of wave rotor topping on the engine cycle and the subsequent need to rematch compressor and turbine sections in the topped engine were addressed. Comparison of performance of the resulting engine is made on the basis of wave rotor topped engine versus an appropriate baseline engine using common shaft compressor hardware. The topped engine design clearly demonstrates an impressive improvement in shaft horsepower (+11.4%) and SFC (-22%). Off design part power engine performance for the wave rotor topped engine was similarly improved including that at engine idle conditions. Operation of the engine at off design was closely examined with wave rotor operation at less than design burner outlet temperatures and rotor speeds. Challenges identified in the development of a demonstrator engine are discussed. A preliminary design was made of the demonstrator engine including wave rotor to engine transition ducts. Program cost and schedule for a wave rotor demonstrator engine fabrication and test program were developed.
DOT/NASA comparative assessment of Brayton engines for guideway vehicle and buses. Volume 1: Summary
NASA Technical Reports Server (NTRS)
1975-01-01
The Department of Transportation requested that the NASA Office of Aeronautics and Space Technology evaluate and assess the potential of several types of gas turbine engines and fuels for the on-board power and propulsion of a future heavy-duty ground transportation system. The purpose of the investigation was threefold: (1) to provide a definition of the potential for turbine engines to minimize pollution, energy consumption, and noise; (2) to provide a useful means of comparison of the types of engine based on consistent assumptions and a common analytical approach; and (3) to provide a compendium of comparative performance data that would serve as the technical basis for future planning. Emphasis was on establishing comparison trends rather than on absolute values and a definitive engine selection. The primary value of this study is intended to be usefulness of the results to provide a quantitative basis for future judgement.
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…
Writing in the Natural Sciences and Engineering: Implications for ESL Composition Courses.
ERIC Educational Resources Information Center
Braine, George
A study investigated the types of writing assignments commonly found in undergraduate natural sciences and engineering courses. The study was used as a basis for the development of composition courses for limited-English-speaking students in these fields, the most popular fields of study among foreign students. Eighty take-home assignments given…
NASA Astrophysics Data System (ADS)
Bespalov, V.; Kotlyarova, E.
2017-10-01
In modern conditions of a stable urban areas development special place is occupied by the problem of ecological security of built-up areas, including residential, recreational, industrial areas and objects of transport and engineering infrastructure. The main results of the study are to establish the basis of formation of the concept of choice of energy-efficient technologies and tools of forming an ecologically efficient “green frame” of urban areas on the basis of a single integrated scientific concept. Analysis allowed us to divide the measures for improvement into the following main groups: organizational and planning, engineering and technical and special engineering and environmental. The significance of these results for the construction industry, including transport infrastructure, is to increase the level of environmental safety in the construction and reconstruction of urban areas due to the organization of their improvement on the basis suggested by the authors scientific approach. Its basis is integrated accounting of the natural and climatic features of the landscaping territory, the types and level of environmental impact of negative anthropogenic factors, the features of architectural and planning solutions of the existing or projected on the studied area, the structure and types of green spaces and their functional ecological properties.
Engineering education for the 1980's: A speculation
NASA Technical Reports Server (NTRS)
Covert, E. E.
1975-01-01
The development of a course of study is briefly examined from two points of view. The first represents the background that would seem to be needed for a fledgling engineer upon his entry into the engineering profession and would allow him to complete successfully his on-the-job training, or engineering internship as it were. The second represents that which must be provided on the basis of the students background from secondary school. It is suggested that a course of study viewed in this way is never fixed, but rather evolves continuously. A particular evolving course of study is briefly discussed.
Advanced stratified charge rotary aircraft engine design study
NASA Technical Reports Server (NTRS)
Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.
1982-01-01
A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.
DOT National Transportation Integrated Search
2014-02-01
This report presents materials that can be used as the basis for a module on signalized intersections in the introductory : course in transportation engineering. The materials were developed based on studies of the work of students who took : this in...
Taiwanese Preservice Teachers' Science, Technology, Engineering, and Mathematics Teaching Intention
ERIC Educational Resources Information Center
Lin, Kuen-Yi; Williams, P. John
2016-01-01
This study applies the theory of planned behavior as a basis for exploring the impact of knowledge, values, subjective norms, perceived behavioral controls, and attitudes on the behavioral intention toward science, technology, engineering, and mathematics (STEM) education among Taiwanese preservice science teachers. Questionnaires (N = 139)…
40 CFR 270.14 - Contents of part B: General requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... the extent required, the Director may make allowance for submission of such information on a case-by-case basis. Information required in part B shall be submitted to the Director and signed in accordance..., and engineering studies shall be certified by a qualified Professional Engineer. For post-closure...
40 CFR 270.14 - Contents of part B: General requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... the extent required, the Director may make allowance for submission of such information on a case-by-case basis. Information required in part B shall be submitted to the Director and signed in accordance..., and engineering studies shall be certified by a qualified Professional Engineer. For post-closure...
40 CFR 270.14 - Contents of part B: General requirements.
Code of Federal Regulations, 2014 CFR
2014-07-01
... the extent required, the Director may make allowance for submission of such information on a case-by-case basis. Information required in part B shall be submitted to the Director and signed in accordance..., and engineering studies shall be certified by a qualified Professional Engineer. For post-closure...
40 CFR 270.14 - Contents of part B: General requirements.
Code of Federal Regulations, 2012 CFR
2012-07-01
... the extent required, the Director may make allowance for submission of such information on a case-by-case basis. Information required in part B shall be submitted to the Director and signed in accordance..., and engineering studies shall be certified by a qualified Professional Engineer. For post-closure...
Fundamental Studies in the Molecular Basis of Laser Induced Retinal Damage
1988-01-01
Cornell University School of Applied & Engineering Physics Ithaca, NY 14853 DOD DISTRIBUTION STATEMENT Approved for public release; distribution unlimited...Code) 7b. ADDRESS (City, State, and ZIP Code) School of Applied & Engineering Physics Ithaca, NY 14853 8a. NAME OF FUNDING/SPONSORING Bb. OFFICE SYMBOL
Fundamental Studies in the Molecular Basis of Laser Induced Retinal Damage
1988-01-01
Cornell University .LECT l School of Applied & Engineering PhysicsIthaca, NY 14853 0 JAN 198D DOD DISTRIBUTION STATEMENT Approved for public release...State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) School of Applied & Engineering Physics Ithaca, NY 14853 Ba. NAME OF FUNDING/ SPONSORING
ERIC Educational Resources Information Center
Wai, Jonathan; Lubinski, David; Benbow, Camilla P.; Steiger, James H.
2010-01-01
Two studies examined the relationship between precollegiate advanced/enriched educational experiences and adult accomplishments in science, technology, engineering, and mathematics (STEM). In Study 1, 1,467 13-year-olds were identified as mathematically talented on the basis of scores [greater than or equal to] 500 (top 0.5%) on the math section…
ERIC Educational Resources Information Center
Kinnari-Korpela, Hanna
2015-01-01
Mathematics' skills and knowledge lay the basis for engineering studies. However, the resources targeted to mathematics' teaching are in many cases very limited. During the past years in our university the reduction of mathematics' contact hours has been significant while at the same time the study groups have grown. However, the mathematical…
NASA Astrophysics Data System (ADS)
Shishkovsky, Igor; Scherbakov, Vladimir; Volchkov, Vladislav; Volova, Larisa
2018-02-01
The conditions of selective laser melting (SLM) of tissue engineering scaffolds affect cell response and must be engineered to support cell adhesion, proliferation, and differentiation. In the present study, the influence of additional heating during SLM process on stem cell viability near biopolymer matrix reinforced by nanoceramics additives was carried out. We used the biocompatible and bioresorbable polymers (polyetheretherketone /PEEK/ and polycaprolactone /PCL/) as a matrix and nano-oxide ceramics - TiO2, Al2O3, ZrO2, FexOy and/or hydroxyapatite as a basis of the additives. The rate of pure PEEK and PCL bio-resorption and in mixtures with nano oxides on the matrix was studied by the method of mass loss on bacteria of hydroxylase and enzyme complex. The stem cellular morphology, proliferative MMSC activity, and adhesion of the 2D and 3D nanocomposite matrices were the subjects of comparison. Medical potential of the SLS/M-fabricated nano-oxide ceramics after additional heating as the basis for tissue engineering scaffolds and cell targeting systems were discussed.
Artistic and Industrial Institutions in Russian Education Structure in First Quarter of XXth Century
NASA Astrophysics Data System (ADS)
Chernyh, D. G.
2017-11-01
The article tells about the formation of Russian design education in the XXth century. It focuses on the peculiar features and causes of its insufficient effectiveness in the historical context. It studies the dynamics of changes in the priorities related to the artistic and industrial education in Russia and the connection of these processes with socio-political transformations. The article identifies the role of constructivist artists in the formation and approbation of advanced design-engineering techniques. It emphasizes the interdisciplinary essence of the profession of a designer as a special kind of design activities, its organizing, consolidating and progressive origin in the sphere of industrial production and carrying out interdisciplinary studies. It discloses the essence of a new “engineer-artist” profession. It briefly describes the influence of the fundamental principle of design - projectivity, on engineering and design disciplines when the interaction of an artist, an engineer and an architect is achieved on the basis of design, arrangement and inventive art as well as production organization where science and technology form the basis for creative work.
Supersonic through-flow fan engine and aircraft mission performance
NASA Technical Reports Server (NTRS)
Franciscus, Leo C.; Maldonado, Jaime J.
1989-01-01
A study was made to evaluate potential improvement to a commercial supersonic transport by powering it with supersonic through-flow fan turbofan engines. A Mach 3.2 mission was considered. The three supersonic fan engines considered were designed to operate at bypass ratios of 0.25, 0.5, and 0.75 at supersonic cruise. For comparison a turbine bypass turbojet was included in the study. The engines were evaluated on the basis of aircraft takeoff gross weight with a payload of 250 passengers for a fixed range of 5000 N.MI. The installed specific fuel consumption of the supersonic fan engines was 7 to 8 percent lower than that of the turbine bypass engine. The aircraft powered by the supersonic fan engines had takeoff gross weights 9 to 13 percent lower than aircraft powered by turbine bypass engines.
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.
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
Study, optimization, and design of a laser heat engine
NASA Technical Reports Server (NTRS)
1978-01-01
Laser heat engine concepts, proposed for satellite applications, were analyzed to determine which engine concepts best meet the requirements of high efficiency (50 percent or better) continuous operation in space. The best laser heat engine for a near-term experimental demonstration, selected on the basis of high overall operating efficiency, high power-to-weight characteristics, and availability of the required technology, is an Otto/Diesel cycle piston engine using a diamond window to admit CO2 laser radiation. The technology with the greatest promise of scaling to megawatt power levels in the long term is the energy exchanger/gas turbine combination.
Liu, Yu-Qing; Keane, Michael; Ensell, Mang; Miller, William; Kashon, Michael; Ong, Tong-man; Mauderly, Joe; Lawson, Doug; Gautam, Mridul; Zielinska, Barbara; Whitney, Kevin; Eberhardt, James; Wallace, William
2005-01-01
Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from a set of 1998-2000 model year normal emitter diesel engine automobile or light trucks and from a set of 1982-1996 normal emitter gasoline engine automobiles or light trucks operated on the California Unified Driving Cycle at 22 [degree]C were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens for Salmonella typhimurium strains YG1024 and YG1029 on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage indicated by micronucleus induction in Chinese hamster lung fibroblasts (V79 cells), diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage in V79 cells indicated by the single cell gel electrophoresis (SCGE) assay, gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.
NASA Astrophysics Data System (ADS)
Sixiang, Chen; Daopin, Chen; Ming, Zhang; Xiao, Huang; Jian, He; Zhijie, He
2017-05-01
Aimed at the actual situation of fish death in fish ponds near the power transmission line towers after the thunderstorm happened in Guangdong Province in China, this paper studied the influence of the ground current on fish in the pond. Firstly, This paper studied the current density of the fish without protection. On this basis, paper studied the horizontal pole with full-shielded, the vertical pole with half-shielded, the horizontal pole with extension three kinds of protective measures and effects. Finally an effective protection scheme was put forward according to the engineering practice. The results can provide some engineering guidance and quantitative basis for the design and modification of grounding devices when the tower is adjacent to the fish ponds in southern China.
Molecular Bases of Enantioselectivity of Haloalkane Dehalogenase DbjA
NASA Astrophysics Data System (ADS)
Sato, Yukari; Natsume, Ryo; Prokop, Zbynek; Brezovsky, Jan; Chaloupkova, Radka; Damborsky, Jiri; Nagata, Yuji; Senda, Toshiya
Enzymes are widely used for the synthesis of pharmaceuticals, agrochemicals, and food additives because they can catalyze high enantioselective transformations. In order to construct selective enzymes by protein engineering, it is important to understand the molecular basis of enzyme-substrate interactions that contribute to enantioselectivity. The haloalkane dehalogenase DbjA showed high enantioselectivity for two racemic mixtures: α-bromoesters and β-bromoalkanes. Thermodynamic analysis, protein crystallography, and computer simulations indicated that DbjA carries two bases for the enantiodiscrimination of each racemic mixture. This study helps us understand the molecular basis of the enantioselectivity and opens up new possibilities for constructing enantiospecific biocatalysts through protein engineering.
Cooper, Rory A; Koontz, Alicia M; Ding, Dan; Kelleher, Annmarie; Rice, Ian; Cooper, Rosemarie
2010-01-01
Medical rehabilitation and assistive technology are immersed in a world transitioning to a basis in evidence-based practice. Fortunately, there is a growing body of knowledge related to manual wheelchair mobility to form a basis for clinical decision making. The results from research studies are useful for designing better wheelchairs, fitting and training people appropriately, contributing to evidence-based-medicine and guiding future research. This review describes some of the work related to manual wheelchairs that has and is being conducted within the University of Pittsburgh and the Human Engineering Research Laboratories of the United States Department of Veterans Affairs, and its application.
Avco Lycoming/NASA contract status. [on reduction of emissions from aircraft piston engines
NASA Technical Reports Server (NTRS)
Duke, L. C.
1976-01-01
The standards promulgated by the Environmental Protection Agency (EPA) for carbon monoxide (CO), unburned hydrocarbon (HC), and oxides-of-nitrogen (NOx) emissions were the basis in a study of ways to reduce emissions from aircraft piston engines. A variable valve timing system, ultrasonic fuel atomization, and ignition system changes were postulated.
Cognitive Mapping Techniques: Implications for Research in Engineering and Technology Education
ERIC Educational Resources Information Center
Dixon, Raymond A.; Lammi, Matthew
2014-01-01
The primary goal of this paper is to present the theoretical basis and application of two types of cognitive maps, concept map and mind map, and explain how they can be used by educational researchers in engineering design research. Cognitive mapping techniques can be useful to researchers as they study students' problem solving strategies…
Engineering Ethics Education on the Basis of Continuous Education to Improve Communication Ability
NASA Astrophysics Data System (ADS)
Takahara, Kenji; Kajiwara, Toshinori
The paper proposes the engineering ethics education method for students on the basis of continuous education to improve communication ability. First, through a debate, the students acquire the fundamental skills required to marshal their arguments, to construct the rebuttals and to summarize the debates. Secondly, the students study the fundamental techniques to make a presentation on technical subjects related to electrical engineering. Following these classes, in the lecture of engineering ethics, the students probe the cause of each accident and consider the better means for avoiding such an accident, each other. In most cases, the students can express right and commonsensical opinions from an ethical standpoint. However, they can hardly make judgments when the situations such as the human relations in the above accidents are set concretely. During the engineering ethics class, the students come to know that human relations behind the case make the ethical matters more complicated. Furthermore, they come to understand that facilitating daily communications with co-workers and/or bosses is very important in order to avoid the accidents. The recognition of the students is just the results of the continuous education through three years. It can be said that the engineering ethics education thus constructed makes the students raise such spontaneous awareness and their ethical qualities as engineers.
Engineering Education as a Complex System
ERIC Educational Resources Information Center
Gattie, David K.; Kellam, Nadia N.; Schramski, John R.; Walther, Joachim
2011-01-01
This paper presents a theoretical basis for cultivating engineering education as a complex system that will prepare students to think critically and make decisions with regard to poorly understood, ill-structured issues. Integral to this theoretical basis is a solution space construct developed and presented as a benchmark for evaluating…
ERIC Educational Resources Information Center
Xinqiang, Wei
2012-01-01
This paper gives a brief analysis on the educational advantages and objects of NCWU. It believes that the educational philosophy and development direction of foreign school in engineering colleges must be set up on the basis of need of China and talents need, moreover, the development of the School of Foreign Studies must be analyzed by…
NASA Astrophysics Data System (ADS)
Makarova, A. N.; Makarov, E. I.; Zakharov, N. S.
2018-03-01
In the article, the issue of correcting engineering servicing regularity on the basis of actual dependability data of cars in operation is considered. The purpose of the conducted research is to increase dependability of transport-technological machines by correcting engineering servicing regularity. The subject of the research is the mechanism of engineering servicing regularity influence on reliability measure. On the basis of the analysis of researches carried out before, a method of nonparametric estimation of car failure measure according to actual time-to-failure data was chosen. A possibility of describing the failure measure dependence on engineering servicing regularity by various mathematical models is considered. It is proven that the exponential model is the most appropriate for that purpose. The obtained results can be used as a separate method of engineering servicing regularity correction with certain operational conditions taken into account, as well as for the technical-economical and economical-stochastic methods improvement. Thus, on the basis of the conducted researches, a method of engineering servicing regularity correction of transport-technological machines in the operational process was developed. The use of that method will allow decreasing the number of failures.
Directed evolution and synthetic biology applications to microbial systems.
Bassalo, Marcelo C; Liu, Rongming; Gill, Ryan T
2016-06-01
Biotechnology applications require engineering complex multi-genic traits. The lack of knowledge on the genetic basis of complex phenotypes restricts our ability to rationally engineer them. However, complex phenotypes can be engineered at the systems level, utilizing directed evolution strategies that drive whole biological systems toward desired phenotypes without requiring prior knowledge of the genetic basis of the targeted trait. Recent developments in the synthetic biology field accelerates the directed evolution cycle, facilitating engineering of increasingly complex traits in biological systems. In this review, we summarize some of the most recent advances in directed evolution and synthetic biology that allows engineering of complex traits in microbial systems. Then, we discuss applications that can be achieved through engineering at the systems level. Copyright © 2016 Elsevier Ltd. All rights reserved.
What Do Engineers Want? Examining Engineering Education through Bloom's Taxonomy
ERIC Educational Resources Information Center
Goel, Sanjay; Sharda, Nalin
2004-01-01
Using Bloom's taxonomy as the basis for an empirical investigation, this paper examines what engineering students and professionals want from engineering education. Fifty engineering students, from Computer Science and Information Technology courses, were asked to rank activity verbs in order of their impression about frequency of their occurrence…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Farrell, John
This presentation reports recent progress on light-duty boosted spark-ignition fuels/engines being developed under the Co-Optimization of Fuels and Engines initiative (Co-Optima). Co-Optima is focused on identifying fuel properties that optimize engine performance, independent of composition, allowing the market to define the best means to blend and provide these fuels. However, in support of this, we are pursuing a systematic study of blendstocks to identify a broad range of feasible options, with the objective of identifying blendstocks that can provide target ranges of key fuel properties, identifying trade-offs on consistent and comprehensive basis, and sharing information with stakeholders.
Engineering education as a complex system
NASA Astrophysics Data System (ADS)
Gattie, David K.; Kellam, Nadia N.; Schramski, John R.; Walther, Joachim
2011-12-01
This paper presents a theoretical basis for cultivating engineering education as a complex system that will prepare students to think critically and make decisions with regard to poorly understood, ill-structured issues. Integral to this theoretical basis is a solution space construct developed and presented as a benchmark for evaluating problem-solving orientations that emerge within students' thinking as they progress through an engineering curriculum. It is proposed that the traditional engineering education model, while analytically rigorous, is characterised by properties that, although necessary, are insufficient for preparing students to address complex issues of the twenty-first century. A Synthesis and Design Studio model for engineering education is proposed, which maintains the necessary rigor of analysis within a uniquely complex yet sufficiently structured learning environment.
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.
Restriction of virus infection by plants. Final report, July 1, 1987--June 30, 1992
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruening, G.
1992-12-31
The basis of genotypic resistance of the Arlington line of cowpea (Vigna unguiculata) against cowpea mosaic virus (CPMV) has been attributed, to an inhibitor of the processing of CPMV polyproteins. We sought to purify the protein that is postulated to be the inhibitor of polyprotein processing and to characterize the inhibitor and its gene. Such information can be the basis for engineering resistance to specific viruses in plants. In studies with cherry leafroll virus (CLRV) we sought understanding of the biochemical basis of the resistance.
Ariyasu, Hiroyuki; Akamizu, Takashi
2015-01-01
Ghrelin, an endogenous ligand for the growth hormone (GH) secretagogue receptor (GHS-R or ghrelin receptor), is a 28-amino acid acylated peptide mainly produced in the stomach. The pharmacological administration of ghrelin is known to exert diverse effects, such as stimulating GH secretion, promoting food intake, and increasing adiposity. In recent years, genetically engineered mouse models have provided important insights into the physiology of various hormones. In this review, we discuss current knowledge regarding the physiological significance of ghrelin on the basis of studies using genetically engineered mouse models with modifications in the ghrelin system.
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.
Diesel Fuel Alternatives for Engines in Civil Works Prime Movers.
1984-09-01
2. h5 -21 _____ 2 1 -2 11114 . MICROCOP RESOLUTION Tl HART * US Army Corpsof Engineers INTERIM REPORT E-200 -September 1981 a-t i r Technology to...on Raw Coal--No. 2 Fuel Oil Slurries 36 14 Comparison on Power Basis of Amount of SOX Compounds in Exhaust of a Single-Cylinder 1360-cc Diesel Engine...Fuel by F0o by o wt t wt. 0. 0 116-F Pitb g Co a Coal Coal Figure 14. Comparison on power basis of amount ot SO compounds in XI exhast f asingle
Small Engine Technology (SET) - Task 4, Regional Turboprop/Turbofan Engine Advanced Combustor Study
NASA Technical Reports Server (NTRS)
Reynolds, Robert; Srinivasan, Ram; Myers, Geoffrey; Cardenas, Manuel; Penko, Paul F. (Technical Monitor)
2003-01-01
Under the SET Program Task 4 - Regional Turboprop/Turbofan Engine Advanced Combustor Study, a total of ten low-emissions combustion system concepts were evaluated analytically for three different gas turbine engine geometries and three different levels of oxides of nitrogen (NOx) reduction technology, using an existing AlliedSignal three-dimensional (3-D) Computational Fluid Dynamics (CFD) code to predict Landing and Takeoff (LTO) engine cycle emission values. A list of potential Barrier Technologies to the successful implementation of these low-NOx combustor designs was created and assessed. A trade study was performed that ranked each of the ten study configurations on the basis of a number of manufacturing and durability factors, in addition to emissions levels. The results of the trade study identified three basic NOx-emissions reduction concepts that could be incorporated in proposed follow-on combustor technology development programs aimed at demonstrating low-NOx combustor hardware. These concepts are: high-flow swirlers and primary orifices, fuel-preparation cans, and double-dome swirlers.
System and method for optical fiber based image acquisition suitable for use in turbine engines
Baleine, Erwan; A V, Varun; Zombo, Paul J.; Varghese, Zubin
2017-05-16
A system and a method for image acquisition suitable for use in a turbine engine are disclosed. Light received from a field of view in an object plane is projected onto an image plane through an optical modulation device and is transferred through an image conduit to a sensor array. The sensor array generates a set of sampled image signals in a sensing basis based on light received from the image conduit. Finally, the sampled image signals are transformed from the sensing basis to a representation basis and a set of estimated image signals are generated therefrom. The estimated image signals are used for reconstructing an image and/or a motion-video of a region of interest within a turbine engine.
Reliability analysis of C-130 turboprop engine components using artificial neural network
NASA Astrophysics Data System (ADS)
Qattan, Nizar A.
In this study, we predict the failure rate of Lockheed C-130 Engine Turbine. More than thirty years of local operational field data were used for failure rate prediction and validation. The Weibull regression model and the Artificial Neural Network model including (feed-forward back-propagation, radial basis neural network, and multilayer perceptron neural network model); will be utilized to perform this study. For this purpose, the thesis will be divided into five major parts. First part deals with Weibull regression model to predict the turbine general failure rate, and the rate of failures that require overhaul maintenance. The second part will cover the Artificial Neural Network (ANN) model utilizing the feed-forward back-propagation algorithm as a learning rule. The MATLAB package will be used in order to build and design a code to simulate the given data, the inputs to the neural network are the independent variables, the output is the general failure rate of the turbine, and the failures which required overhaul maintenance. In the third part we predict the general failure rate of the turbine and the failures which require overhaul maintenance, using radial basis neural network model on MATLAB tool box. In the fourth part we compare the predictions of the feed-forward back-propagation model, with that of Weibull regression model, and radial basis neural network model. The results show that the failure rate predicted by the feed-forward back-propagation artificial neural network model is closer in agreement with radial basis neural network model compared with the actual field-data, than the failure rate predicted by the Weibull model. By the end of the study, we forecast the general failure rate of the Lockheed C-130 Engine Turbine, the failures which required overhaul maintenance and six categorical failures using multilayer perceptron neural network (MLP) model on DTREG commercial software. The results also give an insight into the reliability of the engine turbine under actual operating conditions, which can be used by aircraft operators for assessing system and component failures and customizing the maintenance programs recommended by the manufacturer.
NASA Technical Reports Server (NTRS)
Gupta, U. K.; Ali, M.
1988-01-01
The theoretical basis and operation of LEBEX, a machine-learning system for jet-engine performance monitoring, are described. The behavior of the engine is modeled in terms of four parameters (the rotational speeds of the high- and low-speed sections and the exhaust and combustion temperatures), and parameter variations indicating malfunction are transformed into structural representations involving instances and events. LEBEX extracts descriptors from a set of training data on normal and faulty engines, represents them hierarchically in a knowledge base, and uses them to diagnose and predict faults on a real-time basis. Diagrams of the system architecture and printouts of typical results are shown.
Code of Federal Regulations, 2012 CFR
2012-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2013 CFR
2013-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2010 CFR
2010-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2011 CFR
2011-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2014 CFR
2014-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...
The transformation of heat in an engine
NASA Technical Reports Server (NTRS)
Neumann, Kurt
1929-01-01
This report presents a thermodynamic basis for rating heat engines. The production of work by a heat engine rests on the operation of supplying heat, under favorable conditions, to a working fluid and then taking it away.
Research on Visualization Design Method in the Field of New Media Software Engineering
NASA Astrophysics Data System (ADS)
Deqiang, Hu
2018-03-01
In the new period of increasingly developed science and technology, with the increasingly fierce competition in the market and the increasing demand of the masses, new design and application methods have emerged in the field of new media software engineering, that is, the visualization design method. Applying the visualization design method to the field of new media software engineering can not only improve the actual operation efficiency of new media software engineering but more importantly the quality of software development can be enhanced by means of certain media of communication and transformation; on this basis, the progress and development of new media software engineering in China are also continuously promoted. Therefore, the application of visualization design method in the field of new media software engineering is analysed concretely in this article from the perspective of the overview of visualization design methods and on the basis of systematic analysis of the basic technology.
About, for, in or through Entrepreneurship in Engineering Education
ERIC Educational Resources Information Center
Mäkimurto-Koivumaa, Soili; Belt, Pekka
2016-01-01
Engineering competences form a potential basis for entrepreneurship. There are pressures to find new approaches to entrepreneurship education (EE) in engineering education, as the traditional analytical logic of engineering does not match the modern view of entrepreneurship. Since the previous models do not give tangible enough tools on how to…
Parallel Algorithms for Groebner-Basis Reduction
1987-09-25
22209 ELEMENT NO. NO. NO. ACCESSION NO. 11. TITLE (Include Security Classification) * PARALLEL ALGORITHMS FOR GROEBNER -BASIS REDUCTION 12. PERSONAL...All other editions are obsolete. Productivity Engineering in the UNIXt Environment p Parallel Algorithms for Groebner -Basis Reduction Technical Report
NASA Technical Reports Server (NTRS)
Spears, L. T.; Kramer, R. D.
1990-01-01
The objectives were to examine launch vehicle applications and propulsion requirements for potential future manned space transportation systems and to support planning toward the evolution of Space Shuttle Main Engine (SSME) and Space Transportation Main Engine (STME) engines beyond their current or initial launch vehicle applications. As a basis for examinations of potential future manned launch vehicle applications, we used three classes of manned space transportation concepts currently under study: Space Transportation System Evolution, Personal Launch System (PLS), and Advanced Manned Launch System (AMLS). Tasks included studies of launch vehicle applications and requirements for hydrogen-oxygen rocket engines; the development of suggestions for STME engine evolution beyond the mid-1990's; the development of suggestions for STME evolution beyond the Advanced Launch System (ALS) application; the study of booster propulsion options, including LOX-Hydrocarbon options; the analysis of the prospects and requirements for utilization of a single engine configuration over the full range of vehicle applications, including manned vehicles plus ALS and Shuttle C; and a brief review of on-going and planned LOX-Hydrogen propulsion technology activities.
Wildlife Habitat Impact Assessment, Chief Joseph Dam Project, Washington : Project Report 1992.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuehn, Douglas; Berger, Matthew
1992-01-01
Under the Pacific Northwest Electric Power Planning and Conservation Act of 1980, and the subsequent Northwest Power Planning Council`s Columbia River Basin Fish and Wildlife Program, a wildlife habitat impact assessment and identification of mitigation objectives have been developed for the US Army Corps of Engineer`s Chief Joseph Dam Project in north-central Washington. This study will form the basis for future mitigation planning and implementation.
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.
Software Engineering Education Directory
1990-04-01
and Engineering (CMSC 735) Codes: GPEV2 * Textiooks: IEEE Tutoria on Models and Metrics for Software Management and Engameeing by Basi, Victor R...Software Engineering (Comp 227) Codes: GPRY5 Textbooks: IEEE Tutoria on Software Design Techniques by Freeman, Peter and Wasserman, Anthony 1. Software
Trinh, Cong T.; Wlaschin, Aaron; Srienc, Friedrich
2010-01-01
Elementary Mode Analysis is a useful Metabolic Pathway Analysis tool to identify the structure of a metabolic network that links the cellular phenotype to the corresponding genotype. The analysis can decompose the intricate metabolic network comprised of highly interconnected reactions into uniquely organized pathways. These pathways consisting of a minimal set of enzymes that can support steady state operation of cellular metabolism represent independent cellular physiological states. Such pathway definition provides a rigorous basis to systematically characterize cellular phenotypes, metabolic network regulation, robustness, and fragility that facilitate understanding of cell physiology and implementation of metabolic engineering strategies. This mini-review aims to overview the development and application of elementary mode analysis as a metabolic pathway analysis tool in studying cell physiology and as a basis of metabolic engineering. PMID:19015845
ERIC Educational Resources Information Center
Zhao, Feng-qing; Yu, Yi-feng; Ren, Shao-feng; Liu, Shao-jie; Rong, Xin-yu
2014-01-01
Practical education in chemical engineering has drawn increasing attention in recent years. This paper discusses two approaches to teaching and learning about experiments among upper-level chemical and pharmaceutical engineering majors in China. On the basis of years of experience in teaching chemical and pharmaceutical engineering, we propose the…
76 FR 37158 - Agency Information Collection Activities: Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-24
... Presidential Awards for Excellence in Science, Mathematics and Engineering Mentoring (PAESMEM) program. In 2003... representative scientific or engineering organization.'' On the basis of these recommendations, the Committee was... individual's work on the current state of physical, biological, mathematical, engineering or social and...
Physical-scale models of engineered log jams in rivers
USDA-ARS?s Scientific Manuscript database
Stream restoration and river engineering projects are employing engineered log jams increasingly for stabilization and in-stream improvements. To further advance the design of these structures and their morphodynamic effects on corridors, the basis for physical-scale models of rivers with engineere...
Generalization of the Engineering Method to the UNIVERSAL METHOD.
ERIC Educational Resources Information Center
Koen, Billy Vaughn
1987-01-01
Proposes that there is a universal method for all realms of knowledge. Reviews Descartes's definition of the universal method, the engineering definition, and the philosophical basis for the universal method. Contends that the engineering method best represents the universal method. (ML)
DESIGN CONSIDERATIONS FOR PULP AND PAPER-MILL SLUDGE LANDFILLS
This report presents procedures for the engineering design and control of pulp and paper-mill sludge disposal landfills. Engineering design will allow more efficient use, thereby contributing to economic and environmental benefits. To form the basis for engineering design of slud...
Research on the Investment Costs of IT Project
NASA Astrophysics Data System (ADS)
Zurong, Chen; Feng, Jingchun
2018-02-01
The investment costs of IT project are the basis of IT project management. The meaning and composition of the investment costs of IT project were analyzed in this paper, which involving the engineering cost of IT project, the other costs of IT project, reserve cost and financing interest of the construction period. On this basis, the composition and content of static investment costs and dynamic investment costs of IT project were also studied in the paper.
ERIC Educational Resources Information Center
Breyer, F. Jay; Attali, Yigal; Williamson, David M.; Ridolfi-McCulla, Laura; Ramineni, Chaitanya; Duchnowski, Matthew; Harris, April
2014-01-01
In this research, we investigated the feasibility of implementing the "e-rater"® scoring engine as a check score in place of all-human scoring for the "Graduate Record Examinations"® ("GRE"®) revised General Test (rGRE) Analytical Writing measure. This report provides the scientific basis for the use of e-rater as a…
Reliability-Growth Assessment, Prediction, and Control for Electronic Engine Control (GAPCEEC)
1984-04-01
COMPEtTIN FOR Control (GAPCEEC) 4. PERFORMING ORG. REPORT NUMUR ______________________________ P&W/GPD/FR-17847 7. AUTI4OR(e) Michael E. McGlone...Control for Electronic Engine Control (GAPCEEC) program was performed under contract F33615-81 -C-2015. This 22-month program I. was formulated to study and...and (3) that data should be tracked c-ontinuously on an indiidual and fleet basis. UNCLASSIFIED 86CURITY CLASSIICATION OF THIS PAGErWmm Doe Rateio
Safety of engineered allergen-specific immunotherapy vaccines
Focke-Tejkl, Margarete; Valenta, Rudolf
2015-01-01
Purpose of review The purpose of the review is to summarize and comment on recent developments regarding the safety of engineered immunotherapy vaccines. Recent findings In the last 2 years, several studies were published in which allergy vaccines were developed on the basis of chemical modification of natural allergen extracts, the engineering of allergen molecules by recombinant DNA technology and synthetic peptide chemistry, allergen genes, new application routes and conjugation with immune modulatory molecules. Several studies exemplified the general applicability of hypoallergenic vaccines on the basis of recombinant fusion proteins consisting of nonallergenic allergen-derived peptides fused to allergen-unrelated carrier molecules. These vaccines are engineered to reduce both, immunoglobulin E (IgE) as well as allergen-specific T cell epitopes in the vaccines, and thus should provoke less IgE and T-cell-mediated side-effects. They are made to induce allergen-specific IgG antibodies against the IgE-binding sites of allergens with the T-cell help of the carrier molecule. Summary Several interesting examples of allergy vaccines with potentially increased safety profiles have been published. The concept of fusion proteins consisting of allergen-derived hypoallergenic peptides fused to allergen-unrelated proteins that seems to be broadly applicable for a variety of allergens appears to be of particular interest because it promises not only to reduce side-effects but also to increase efficacy and convenience of allergy vaccines. PMID:22885888
About, for, in or through entrepreneurship in engineering education
NASA Astrophysics Data System (ADS)
Mäkimurto-Koivumaa, Soili; Belt, Pekka
2016-09-01
Engineering competences form a potential basis for entrepreneurship. There are pressures to find new approaches to entrepreneurship education (EE) in engineering education, as the traditional analytical logic of engineering does not match the modern view of entrepreneurship. Since the previous models do not give tangible enough tools on how to organise EE in practice, this article aims to develop a new framework for EE at the university level. We approach this aim by analysing existing scientific literature complemented by long-term practical observations, enabling a fruitful interplay between theory and practice. The developed framework recommends aspects in EE to be emphasised during each year of the study process. Action-based learning methods are highlighted in the beginning of studies to support students' personal growth. Explicit business knowledge is to be gradually increased only when professional, field-specific knowledge has been adequately accumulated.
Advanced Subsonic Airplane Design and Economic Studies
NASA Technical Reports Server (NTRS)
Liebeck, Robert H.; Andrastek, Donald A.; Chau, Johnny; Girvin, Raquel; Lyon, Roger; Rawdon, Blaine K.; Scott, Paul W.; Wright, Robert A.
1995-01-01
A study was made to examine the effect of advanced technology engines on the performance of subsonic airplanes and provide a vision of the potential which these advanced engines offered. The year 2005 was selected as the entry-into-service (EIS) date for engine/airframe combination. A set of four airplane classes (passenger and design range combinations) that were envisioned to span the needs for the 2005 EIS period were defined. The airframes for all classes were designed and sized using 2005 EIS advanced technology. Two airplanes were designed and sized for each class: one using current technology (1995) engines to provide a baseline, and one using advanced technology (2005) engines. The resulting engine/airframe combinations were compared and evaluated on the basis on sensitivity to basic engine performance parameters (e.g. SFC and engine weight) as well as DOC+I. The advanced technology engines provided significant reductions in fuel burn, weight, and wing area. Average values were as follows: reduction in fuel burn = 18%, reduction in wing area = 7%, and reduction in TOGW = 9%. Average DOC+I reduction was 3.5% using the pricing model based on payload-range index and 5% using the pricing model based on airframe weight. Noise and emissions were not considered.
Rocket Based Combined Cycle (RBCC) engine inlet
NASA Technical Reports Server (NTRS)
2004-01-01
Pictured is a component of the Rocket Based Combined Cycle (RBCC) engine. This engine was designed to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsion systems and ultimately a Single Stage to Orbit (SSTO) air breathing propulsion system.
Preliminary results on performance testing of a turbocharged rotary combustion engine
NASA Technical Reports Server (NTRS)
Meng, P. R.; Rice, W. J.; Schock, H. J.; Pringle, D. P.
1982-01-01
The performance of a turbocharged rotary engine at power levels above 75 kW (100 hp) was studied. A twin rotor turbocharged Mazda engine was tested at speeds of 3000 to 6000 rpm and boost pressures to 7 psi. The NASA developed combustion diagnostic instrumentation was used to quantify indicated and pumping mean effect pressures, peak pressure, and face to face variability on a cycle by cycle basis. Results of this testing showed that a 5900 rpm a 36 percent increase in power was obtained by operating the engine in the turbocharged configuration. When operating with lean carburetor jets at 105 hp (78.3 kW) and 4000 rpm, a brake specific fuel consumption of 0.45 lbm/lb-hr was measured.
The impact of emerging technologies on an advanced supersonic transport
NASA Technical Reports Server (NTRS)
Driver, C.; Maglieri, D. J.
1986-01-01
The effects of advances in propulsion systems, structure and materials, aerodynamics, and systems on the design and development of supersonic transport aircraft are analyzed. Efficient propulsion systems with variable-cycle engines provide the basis for improved propulsion systems; the propulsion efficienies of supersonic and subsonic engines are compared. Material advances consist of long-life damage-tolerant structures, advanced material development, aeroelastic tailoring, and low-cost fabrication. Improvements in the areas of aerodynamics and systems are examined. The environmental problems caused by engine emissions, airport noise, and sonic boom are studied. The characteristics of the aircraft designed to include these technical advances are described.
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.
Establishment of Systematical Education Program of Engineering Ethics for a Technical College
NASA Astrophysics Data System (ADS)
Kobayashi, Yukito
Engineering ethics education deals with a wide range of matters. Therefore it should not be treated within a single subject, but in a whole curriculum of a college. In Yatsushiro National College of Technology, we have designed a systematic education program of engineering ethics on the basis of “Yatsushiro National College Synthetic Education Program” , which was established in 2002. This education program, including education for formation of character and morality as well, has two distinctive features : five or seven-year successive course of study and cooperation among the departments and teaching staffs. This interactive scheme has produced highly educational effects.
Engines and propellers for powered gliders and light airplanes
NASA Technical Reports Server (NTRS)
Gropp, H
1938-01-01
The object of the present paper is to consider the interaction of engine, propeller, and airplane for the low-power range. The discussion is presented in a form so as to provide the engine builder with a basis in his selection in the type of engine required, a suitable selection being possible only in connection with considerations on the best possible propeller.
ERIC Educational Resources Information Center
National Science Foundation, Washington, DC. Div. of Science Resources Studies.
Reported are manpower data needed by those engaged in science and engineering policy activities. The information is collected from scientists and engineers themselves. The basis of this report is the first survey, in a biennial series, of the Doctoral Roster of Scientists and Engineers, conducted for the National Science Foundation by the…
Comparison of Science Process Skills with STEM Career Interests of Middle School Students
ERIC Educational Resources Information Center
Zorlu, Fulya; Zorlu, Yusuf
2017-01-01
This study was aimed to examine the relation between the STEM (Science, Technology, Engineering and Mathematics) career interests and science process skills of middle school seventh grade students. Method of this study was the relational survey method. The study was conducted on the basis of voluntariness and participants were 133 seventh grade…
Reduction of gas flow nonuniformity in gas turbine engines by means of gas-dynamic methods
NASA Astrophysics Data System (ADS)
Matveev, V.; Baturin, O.; Kolmakova, D.; Popov, G.
2017-08-01
Gas flow nonuniformity is one of the main sources of rotor blade vibrations in the gas turbine engines. Usually, the flow circumferential nonuniformity occurs near the annular frames, located in the flow channel of the engine. This leads to the increased dynamic stresses in blades and as a consequence to the blade damage. The goal of the research was to find an acceptable method of reducing the level of gas flow nonuniformity as the source of dynamic stresses in the rotor blades. Two different methods were investigated during this research. Thus, this study gives the ideas about methods of improving the flow structure in gas turbine engine. On the basis of existing conditions (under development or existing engine) it allows the selection of the most suitable method for reducing gas flow nonuniformity.
Engineering Education 2001. The Samuel Neaman Institute--Technion Report.
ERIC Educational Resources Information Center
Engineering Education, 1987
1987-01-01
Presents a view of future engineering education as perceived by the Technion faculty group on the basis of their own analysis and the insights gathered from workshop discussions. Contrasts basic and specialized education. Reviews the technologies and skills of the future engineer. Gives an overview of curriculum requirements. (CW)
7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units
Code of Federal Regulations, 2013 CFR
2013-01-01
... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...
7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units
Code of Federal Regulations, 2014 CFR
2014-01-01
... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...
7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units
Code of Federal Regulations, 2012 CFR
2012-01-01
... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...
Pedagogical Basis of DAS Formalism in Engineering Education
ERIC Educational Resources Information Center
Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.
2011-01-01
The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other…
Arizona Research Coordinating Unit, Second Annual Report.
ERIC Educational Resources Information Center
Lee, Arthur M.
The Arizona Research Coordinating Unit has concentrated its efforts during the past 18 months on a study of engineering technology which was published in March of 1968. A second major project is a study of vocational-technical education in the state to be used as a basis for future planning. Other activities included assistance with several…
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.
Choi, Hyung-Wook; Frey, H Christopher
2010-05-01
The purpose of this study is to demonstrate a methodology for characterizing at high resolution the energy use and emissions of a plug-in parallel-hybrid diesel-electric school bus (PHSB) to support assessments of sensitivity to driving cycles and comparisons to a conventional diesel school bus (CDSB). Data were collected using onboard instruments for a first-of-a-kind prototype PHSB and a CDSB of the same chassis and engine, operated on actual school bus routes. The engine load was estimated on the basis of vehicle specific power (VSP) and an empirically derived relationship between VSP and engine manifold absolute pressure (MAP). VSP depends on speed, acceleration, and road grade. For the PHSB, the observed electrical discharge or recharge to the traction motor battery was characterized on the basis of VSP. The energy use and emission rates of the PHSB from tailpipe and electricity use were estimated for five real-world driving cycles and compared to the engine fuel use and emissions of the CDSB. The PHSB had the greatest advantage on arterial routes and less advantage on highway or local routes. The coupled VSP-MAP modeling approach enables assessment of a wide variety of driving conditions and comparisons of vehicles with different propulsion technologies.
Engineering Protein Hydrogels Using SpyCatcher-SpyTag Chemistry.
Gao, Xiaoye; Fang, Jie; Xue, Bin; Fu, Linglan; Li, Hongbin
2016-09-12
Constructing hydrogels from engineered proteins has attracted significant attention within the material sciences, owing to their myriad potential applications in biomedical engineering. Developing efficient methods to cross-link tailored protein building blocks into hydrogels with desirable mechanical, physical, and functional properties is of paramount importance. By making use of the recently developed SpyCatcher-SpyTag chemistry, we successfully engineered protein hydrogels on the basis of engineered tandem modular elastomeric proteins. Our resultant protein hydrogels are soft but stable, and show excellent biocompatibility. As the first step, we tested the use of these hydrogels as a drug carrier, as well as in encapsulating human lung fibroblast cells. Our results demonstrate the robustness of the SpyCatcher-SpyTag chemistry, even when the SpyTag (or SpyCatcher) is flanked by folded globular domains. These results demonstrate that SpyCatcher-SpyTag chemistry can be used to engineer protein hydrogels from tandem modular elastomeric proteins that can find applications in tissue engineering, in fundamental mechano-biological studies, and as a controlled drug release vehicle.
Aerodynamic Limits on Large Civil Tiltrotor Sizing and Efficiency
NASA Technical Reports Server (NTRS)
Acree, C W., Jr.
2014-01-01
The NASA Large Civil Tiltrotor (2nd generation, or LCTR2) has been the reference design for avariety of NASA studies of design optimization, engine and gearbox technology, handling qualities, andother areas, with contributions from NASA Ames, Glenn and Langley Centers, plus academic and industrystudies. Ongoing work includes airfoil design, 3D blade optimization, engine technology studies, andwingrotor aerodynamic interference. The proposed paper will bring the design up to date with the latestresults of such studies, then explore the limits of what aerodynamic improvements might hope toaccomplish. The purpose is two-fold: 1) determine where future technology studies might have the greatestpayoff, and 2) establish a stronger basis of comparison for studies of other vehicle configurations andmissions.
ERIC Educational Resources Information Center
Kersten, Jennifer Anna
2013-01-01
In recent years there has been increasing interest in engineering education at the K-12 level, which has resulted in states adopting engineering standards as a part of their academic science standards. From a national perspective, the basis for research into engineering education at the K-12 level is the belief that it is of benefit to student…
Systems engineering technology for networks
NASA Technical Reports Server (NTRS)
1994-01-01
The report summarizes research pursued within the Systems Engineering Design Laboratory at Virginia Polytechnic Institute and State University between May 16, 1993 and January 31, 1994. The project was proposed in cooperation with the Computational Science and Engineering Research Center at Howard University. Its purpose was to investigate emerging systems engineering tools and their applicability in analyzing the NASA Network Control Center (NCC) on the basis of metrics and measures.
Liu, Lu-Wen; Zeng, Wei-Li; Zhu, Xiang-Fei; Wu, Jin-Quan; Lin, Zhao-Xiang
2014-03-01
In the present paper, the time evolution study on slip soils treated by different proportions of ionic soil stabilizer (ISS) water solution was conducted by the LIBS system and the relationship between the cation exchange and such engineering properties of reinforcing soil as plasticity index, cohesive force and coefficient of compressibility were analyzed. The results showed that the cation exchange velocity of the proportion of 1:200 ISS reinforcing soil is the fastest among the three proportions (1:100, 1:200 and 1:300) and the modification effect of engineering performance index is quite obvious. These studies provide an experimental basis for the ISS applied to curing project, and monitoring geotechnical engineering performance by LIBS technology also provides a new way of thinking for the curing project monitoring.
40 CFR 1068.120 - What requirements must I follow to rebuild engines?
Code of Federal Regulations, 2012 CFR
2012-07-01
... systems for fuel metering or electronic control so that it significantly increases the service life of the... must have a reasonable technical basis for knowing that the rebuilt engine's emission control system... believe that the engine with those parts will control emissions of all pollutants at least to the same...
40 CFR 1068.120 - What requirements must I follow to rebuild engines?
Code of Federal Regulations, 2014 CFR
2014-07-01
... systems for fuel metering or electronic control so that it significantly increases the service life of the... must have a reasonable technical basis for knowing that the rebuilt engine's emission control system... believe that the engine with those parts will control emissions of all pollutants at least to the same...
40 CFR 1068.120 - What requirements must I follow to rebuild engines?
Code of Federal Regulations, 2013 CFR
2013-07-01
... systems for fuel metering or electronic control so that it significantly increases the service life of the... must have a reasonable technical basis for knowing that the rebuilt engine's emission control system... believe that the engine with those parts will control emissions of all pollutants at least to the same...
Hydrostatic Pressure Project: Linked-Class Problem-Based Learning in Engineering
ERIC Educational Resources Information Center
Davis, Freddie J.; Lockwood-Cooke, Pamela; Hunt, Emily M.
2011-01-01
Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project…
NASA Astrophysics Data System (ADS)
Yang, Yong-sheng; Ming, An-bo; Zhang, You-yun; Zhu, Yong-sheng
2017-10-01
Diesel engines, widely used in engineering, are very important for the running of equipments and their fault diagnosis have attracted much attention. In the past several decades, the image based fault diagnosis methods have provided efficient ways for the diesel engine fault diagnosis. By introducing the class information into the traditional non-negative matrix factorization (NMF), an improved NMF algorithm named as discriminative NMF (DNMF) was developed and a novel imaged based fault diagnosis method was proposed by the combination of the DNMF and the KNN classifier. Experiments performed on the fault diagnosis of diesel engine were used to validate the efficacy of the proposed method. It is shown that the fault conditions of diesel engine can be efficiently classified by the proposed method using the coefficient matrix obtained by DNMF. Compared with the original NMF (ONMF) and principle component analysis (PCA), the DNMF can represent the class information more efficiently because the class characters of basis matrices obtained by the DNMF are more visible than those in the basis matrices obtained by the ONMF and PCA.
Utilization of waste heat in trucks for increased fuel economy
NASA Technical Reports Server (NTRS)
Leising, C. J.; Purohit, G. P.; Degrey, S. P.; Finegold, J. G.
1978-01-01
The waste heat utilization concepts include preheating, regeneration, turbocharging, turbocompounding, and Rankine engine compounding. Predictions are based on fuel-air cycle analyses, computer simulation, and engine test data. All options are evaluated in terms of maximum theoretical improvements, but the Diesel and adiabatic Diesel are also compared on the basis of maximum expected improvement and expected improvement over a driving cycle. The study indicates that Diesels should be turbocharged and aftercooled to the maximum possible level. The results reveal that Diesel driving cycle performance can be increased by 20% through increased turbocharging, turbocompounding, and Rankine engine compounding. The Rankine engine compounding provides about three times as much improvement as turbocompounding but also costs about three times as much. Performance for either can be approximately doubled if applied to an adiabatic Diesel.
NASA Astrophysics Data System (ADS)
Shi, Yu-Fang; Ma, Yi-Yi; Song, Ping-Ping
2018-03-01
System Reliability Theory is a research hotspot of management science and system engineering in recent years, and construction reliability is useful for quantitative evaluation of project management level. According to reliability theory and target system of engineering project management, the defination of construction reliability appears. Based on fuzzy mathematics theory and language operator, value space of construction reliability is divided into seven fuzzy subsets and correspondingly, seven membership function and fuzzy evaluation intervals are got with the operation of language operator, which provides the basis of corresponding method and parameter for the evaluation of construction reliability. This method is proved to be scientific and reasonable for construction condition and an useful attempt for theory and method research of engineering project system reliability.
Code of Federal Regulations, 2012 CFR
2012-07-01
... employee on the basis of one or more personal breathing zone air samples reflecting full shift exposure on... achieve compliance, including engineering plans and studies used to determine methods selected for... requirements of paragraph (l)(2)(ii) of this section within the past 12 months. In that case, such records...
Code of Federal Regulations, 2014 CFR
2014-07-01
... employee on the basis of one or more personal breathing zone air samples reflecting full shift exposure on... achieve compliance, including engineering plans and studies used to determine methods selected for... requirements of paragraph (l)(2)(ii) of this section within the past 12 months. In that case, such records...
Code of Federal Regulations, 2013 CFR
2013-07-01
... employee on the basis of one or more personal breathing zone air samples reflecting full shift exposure on... achieve compliance, including engineering plans and studies used to determine methods selected for... requirements of paragraph (l)(2)(ii) of this section within the past 12 months. In that case, such records...
29 CFR 1990.111 - General statement of regulatory policy.
Code of Federal Regulations, 2013 CFR
2013-07-01
... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...
29 CFR 1990.111 - General statement of regulatory policy.
Code of Federal Regulations, 2010 CFR
2010-07-01
... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...
29 CFR 1990.111 - General statement of regulatory policy.
Code of Federal Regulations, 2011 CFR
2011-07-01
... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...
29 CFR 1990.111 - General statement of regulatory policy.
Code of Federal Regulations, 2014 CFR
2014-07-01
... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...
29 CFR 1990.111 - General statement of regulatory policy.
Code of Federal Regulations, 2012 CFR
2012-07-01
... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...
SECONDARY WASTE/ETF (EFFLUENT TREATMENT FACILITY) PRELIMINARY PRE-CONCEPTUAL ENGINEERING STUDY
DOE Office of Scientific and Technical Information (OSTI.GOV)
MAY TH; GEHNER PD; STEGEN GARY
2009-12-28
This pre-conceptual engineering study is intended to assist in supporting the critical decision (CD) 0 milestone by providing a basis for the justification of mission need (JMN) for the handling and disposal of liquid effluents. The ETF baseline strategy, to accommodate (WTP) requirements, calls for a solidification treatment unit (STU) to be added to the ETF to provide the needed additional processing capability. This STU is to process the ETF evaporator concentrate into a cement-based waste form. The cementitious waste will be cast into blocks for curing, storage, and disposal. Tis pre-conceptual engineering study explores this baseline strategy, in additionmore » to other potential alternatives, for meeting the ETF future mission needs. Within each reviewed case study, a technical and facility description is outlined, along with a preliminary cost analysis and the associated risks and benefits.« less
Concept Map Engineering: Methods and Tools Based on the Semantic Relation Approach
ERIC Educational Resources Information Center
Kim, Minkyu
2013-01-01
The purpose of this study is to develop a better understanding of technologies that use natural language as the basis for concept map construction. In particular, this study focuses on the semantic relation (SR) approach to drawing rich and authentic concept maps that reflect students' internal representations of a problem situation. The…
The approach to engineering tasks composition on knowledge portals
NASA Astrophysics Data System (ADS)
Novogrudska, Rina; Globa, Larysa; Schill, Alexsander; Romaniuk, Ryszard; Wójcik, Waldemar; Karnakova, Gaini; Kalizhanova, Aliya
2017-08-01
The paper presents an approach to engineering tasks composition on engineering knowledge portals. The specific features of engineering tasks are highlighted, their analysis makes the basis for partial engineering tasks integration. The formal algebraic system for engineering tasks composition is proposed, allowing to set the context-independent formal structures for engineering tasks elements' description. The method of engineering tasks composition is developed that allows to integrate partial calculation tasks into general calculation tasks on engineering portals, performed on user request demand. The real world scenario «Calculation of the strength for the power components of magnetic systems» is represented, approving the applicability and efficiency of proposed approach.
Exergy as a useful tool for the performance assessment of aircraft gas turbine engines: A key review
NASA Astrophysics Data System (ADS)
Şöhret, Yasin; Ekici, Selcuk; Altuntaş, Önder; Hepbasli, Arif; Karakoç, T. Hikmet
2016-05-01
It is known that aircraft gas turbine engines operate according to thermodynamic principles. Exergy is considered a very useful tool for assessing machines working on the basis of thermodynamics. In the current study, exergy-based assessment methodologies are initially explained in detail. A literature overview is then presented. According to the literature overview, turbofans may be described as the most investigated type of aircraft gas turbine engines. The combustion chamber is found to be the most irreversible component, and the gas turbine component needs less exergetic improvement compared to all other components of an aircraft gas turbine engine. Finally, the need for analyses of exergy, exergo-economic, exergo-environmental and exergo-sustainability for aircraft gas turbine engines is emphasized. A lack of agreement on exergy analysis paradigms and assumptions is noted by the authors. Exergy analyses of aircraft gas turbine engines, fed with conventional fuel as well as alternative fuel using advanced exergy analysis methodology to understand the interaction among components, are suggested to those interested in thermal engineering, aerospace engineering and environmental sciences.
NASA Astrophysics Data System (ADS)
Jayaprabakar, J.; Karthikeyan, A.; Saikiran, K.; Beemkumar, N.; Joy, Nivin
2017-05-01
Biodiesel is an alternative and safe fuel to replace conventional petroleum diesel. With high-lubricity and clean-burning ability the biodiesel can be a better fuel component for use in existing diesel engines without any modifications. The aim of this Research was to study the potential use of Macro algae oil, Micro algae oil, Rice Bran oil methyl ester as a substitute for diesel fuel in diesel engine. B10 and B20 blends of these three types of fuels are prepared by transesterification process. The blends on volume basis were used to test them in a four stroke single cylinder diesel engine to study the performance and emission characteristics of these fuels and compared with neat diesel fuel. Also, the property testing of these biofuels were carried out. The biodiesel blends in this study substantially reduces the emission of unburnt hydro carbons and smoke opacity and increases the emission of NOx emission in exhaust gases. These biodiesel blends were consumed more by the engine during testing than Diesel and the brake thermal efficiency and volumetric efficiency for the blends was identical with the Diesel.
Manufacturing engineering: Principles for optimization
NASA Astrophysics Data System (ADS)
Koenig, Daniel T.
Various subjects in the area of manufacturing engineering are addressed. The topics considered include: manufacturing engineering organization concepts and management techniques, factory capacity and loading techniques, capital equipment programs, machine tool and equipment selection and implementation, producibility engineering, methods, planning and work management, and process control engineering in job shops. Also discussed are: maintenance engineering, numerical control of machine tools, fundamentals of computer-aided design/computer-aided manufacture, computer-aided process planning and data collection, group technology basis for plant layout, environmental control and safety, and the Integrated Productivity Improvement Program.
Expanding STEM Opportunities through Inclusive STEM-Focused High Schools
ERIC Educational Resources Information Center
Means, Barbara; Wang, Haiwen; Wei, Xin; Lynch, Sharon; Peters, Vanessa; Young, Viki; Allen, Carrie
2017-01-01
Inclusive STEM high schools (ISHSs) (where STEM is science, technology, engineering, and mathematics) admit students on the basis of interest rather than competitive examination. This study examines the central assumption behind these schools--that they provide students from subgroups underrepresented in STEM with experiences that equip them…
Engineering Graphene Mechanical Systems
2012-07-05
strength material. On the basis of chemical /defect manipulation and recrystallization this technique allows wide-range engineering of mechanical... Engineering Graphene Mechanical Systems Maxim K. Zalalutdinov,† Jeremy T. Robinson,*,† Chad E. Junkermeier,‡ James C. Culbertson, Thomas L. Reinecke...Information ABSTRACT: We report a method to introduce direct bonding between graphene platelets that enables the transformation of a multilayer chemically
2012-08-01
Software Engineering Institute, a federally funded research and development center. Any opinions, findings and conclusions or recommendations...CARNEGIE MELLON UNIVERSITY AND SOFTWARE ENGINEERING INSTITUTE MATERIAL IS FURNISHED ON AN “AS-IS” BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF...required for any other external and/or commercial use. Requests for permission should be directed to the Software Engineering Institute at permission
The Historical Basis of Engineering Ethics
NASA Astrophysics Data System (ADS)
Furuya, Keiichi
There are different objects and motives between scientists and engineers. Science is to create new knowledge (episteme), while technology (techne) is to create new utility. Both types of social responsibility are required for engineer, because modern technology is tightly connected with science. The relationship between ethics for scientists and engineers is discussed as an evolution of ethical objects. A short history of engineering societies in U.S.A. and Japan are introduced with their ethical perspectives. As a conclusion, respect for fundamental rights for existence of those who stand in, with, and around engineers and their societies is needed for better engineering ethics.
Final Rule for Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments
This common set of test requirements is intended to streamline laboratory efforts for EPA and industry and to form the basis for internationally harmonized test procedures for nearly all categories of engines.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-03-17
This report summarizes all work for the Energy Survey of Army Industrial Facilities, Energy Engineering Analysis Program (EEAP) at the Western Area Demilitarization Facility (WADF) of the Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada, authorized under Contract No. DACA05-92-C-0155 with the U.S. Army Corps of Engineers, Sacramento District, California. The purpose of this energy survey is to develop a set of projects and actions that will reduce energy consumption and operating costs of selected facilities at the WADF. A preliminary inspection of facilities at WADF by Keller Gannon that identified potential retrofit opportunities was submitted as the EEAP Study andmore » Criteria Review in December 1993. This document formed the basis of the Detailed Scope of Work for this study. Facilities included in the survey and study, together with operational status.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
LUECK, K.J.
2004-10-18
This report documents an engineering study conducted to evaluate alternatives for treating secondary waste in the secondary treatment train (STT) of the Hanford Site 200 Area Effluent Treatment Facility (ETF). The study evaluates ETF STT treatment alternatives and recommends preferred alternatives for meeting the projected future missions of the ETF. The preferred alternative(s) will process projected future ETF influents to produce a solid waste acceptable for final disposal on the Hanford Site. The main text of this report summarizes the ETF past and projected operations, lists the assumptions about projected operations that provide the basis for the engineering evaluation, andmore » summarizes the evaluation process. The evaluation process includes identification of available modifications to the current ETF process, screens those modifications for technical viability, evaluates the technically viable alternatives, and provides conclusions and recommendations based on that evaluation.« less
Engineering approximations in welding: Bridging the gap between the speculation and simulation
Robino, Charles V.
2016-01-15
During the course of their careers, welding engineers and welding metallurgists are often confronted with questions regarding welding process and properties that on the surface appear to be simple and direct, but are in fact quite challenging. These questions generally mask an underlying complexity whose underpinnings in scientific and applied research predate even the founding of the American Welding Society, and previous Comfort A. Adams lectures provide ample and fascinating evidence of the breadth and depth of this complexity. Using these studies or their own experiences and investigations as a basis, most welding and materials engineers have developed engineering toolsmore » to provide working approaches to these day-to-day questions and problems. In this article several examples of research into developing working approaches to welding problems are presented.« less
Engineering approximations in welding: Bridging the gap between the speculation and simulation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robino, Charles V.
During the course of their careers, welding engineers and welding metallurgists are often confronted with questions regarding welding process and properties that on the surface appear to be simple and direct, but are in fact quite challenging. These questions generally mask an underlying complexity whose underpinnings in scientific and applied research predate even the founding of the American Welding Society, and previous Comfort A. Adams lectures provide ample and fascinating evidence of the breadth and depth of this complexity. Using these studies or their own experiences and investigations as a basis, most welding and materials engineers have developed engineering toolsmore » to provide working approaches to these day-to-day questions and problems. In this article several examples of research into developing working approaches to welding problems are presented.« less
Optimization in the systems engineering process
NASA Technical Reports Server (NTRS)
Lemmerman, Loren A.
1993-01-01
The essential elements of the design process consist of the mission definition phase that provides the system requirements, the conceptual design, the preliminary design and finally the detailed design. Mission definition is performed largely by operations analysts in conjunction with the customer. The result of their study is handed off to the systems engineers for documentation as the systems requirements. The document that provides these requirements is the basis for the further design work of the design engineers at the Lockheed-Georgia Company. The design phase actually begins with conceptual design, which is generally conducted by a small group of engineers using multidisciplinary design programs. Because of the complexity of the design problem, the analyses are relatively simple and generally dependent on parametric analyses of the configuration. The result of this phase is a baseline configuration from which preliminary design may be initiated.
System studies on space plane powered by scram/LACE propulsion system
NASA Astrophysics Data System (ADS)
Maita, Masataka; Miyajima, Hiroshi; Mori, Takashige
1992-12-01
Japan's NAL has undertaken concept-development studies for hypersonic technologies-integrating SSTO spaceplane configurations. Attention is presently given to the scramjet/liquefied air cycle engine (LACE). While the scramjet powers the vehicle begining at Mach 5, the LACE is used above Mach 12 on the basis of excess hydrogen fuel consumption; the Mach 20 orbital speed is thereby gained.
Code of Federal Regulations, 2014 CFR
2014-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... family which can be described on the basis of gross power, emission control system, governed speed... means the collection of engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2012 CFR
2012-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... family which can be described on the basis of gross power, emission control system, governed speed... means the collection of engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2011 CFR
2011-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... family which can be described on the basis of gross power, emission control system, governed speed... means the collection of engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2010 CFR
2010-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... family which can be described on the basis of gross power, emission control system, governed speed... means the collection of engines selected from the population of an engine family for emission testing. ...
Code of Federal Regulations, 2013 CFR
2013-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... family which can be described on the basis of gross power, emission control system, governed speed... means the collection of engines selected from the population of an engine family for emission testing. ...
2004-04-15
Pictured is a component of the Rocket Based Combined Cycle (RBCC) engine. This engine was designed to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsion systems and ultimately a Single Stage to Orbit (SSTO) air breathing propulsion system.
NASA Astrophysics Data System (ADS)
Zavrel, Erik A.
2011-04-01
High school science teachers, of course, want to motivate their students to consider studying science and engineering (S&E) in college. However, many high school students are not familiar with what science and engineering actually entail. They may know science as little more than "systematic discovery" and engineering as nothing but "math-intensive design." Without appreciation for the rich culture of science and engineering, students will be unlikely to choose such a field of study. The Discovery Channel television show Mythbusters helps remedy the lack of understanding many people, especially young people, have about S&E. Mythbusters presents a highly accurate vignette of the culture of science and engineering. Episodes of the show were analyzed for instances in which the culture of science and engineering was accurately depicted. Many resources, including several publications of the National Research Council, informed the media analysis. To encourage more high school students to pursue S&E in college, they need to be exposed to the culture of S&E. Mythbusters provides a window into the often unseen realm of science and engineering, allowing its viewers, who are disproportionately represented among the young adult age bracket, to see what it means to conduct science and engineering on a routine basis. High school science instructors should look to Mythbusters to provide insight into the culture of S&E that textbooks often have difficulty conveying to students.
ERIC Educational Resources Information Center
Cogger, Steven D.; Miley, Daniel H.
2012-01-01
This paper proposes that project-based active learning is a key part of engineering education at the middle school level. One project from a comprehensive middle school engineering curriculum developed by the authors is described to show how active learning and state frameworks can coexist. The theoretical basis for learning and assessment in a…
Weigand, Annika; Beier, Justus P; Schmid, Rafael; Knorr, Tobias; Kilian, David; Götzl, Rebekka; Gerber, Thomas; Horch, Raymund E; Boos, Anja M
2017-03-01
For decades, researchers have been developing a range of promising strategies in bone tissue engineering with the aim of producing a significant clinical benefit over existing therapies. However, a major problem concerns the traditional use of xenogeneic substances for the expansion of cells, which complicates direct clinical transfer. The study's aim was to establish a totally autologous sheep model as a basis for further preclinical studies and future clinical application. Ovine mesenchymal stromal cells (MSC) were cultivated in different concentrations (0%, 2%, 5%, 10%, and 25%) of either autologous serum (AS) or fetal calf serum (FCS). With an increase of serum concentration, enhanced metabolic activity and proliferation could be observed. There were minor differences between MSC cultivated in AS or FCS, comparing gene and protein expression of osteogenic and stem cell markers, morphology, and osteogenic differentiation. MSC implanted subcutaneously in the sheep model, together with a nanostructured bone substitute, either in stable block or moldable putty form, induced similar vascularization and remodeling of the bone substitute irrespective of cultivation of MSC in AS or FCS and osteogenic differentiation. The bone substitute in block form together with MSC proved particularly advantageous in the induction of ectopic bone formation compared to the cell-free control and putty form. It could be demonstrated that AS is suitable for replacement of FCS for cultivation of ovine MSC for bone tissue engineering purposes. Substantial progress has been made in the development of a strictly xenogeneic-free preclinical animal model to bring future clinical application of bone tissue engineering strategies within reach.
NASA Technical Reports Server (NTRS)
1972-01-01
Propulsion system characteristics for a long range, high subsonic (Mach 0.90 - 0.98), jet commercial transport aircraft are studied to identify the most desirable cycle and engine configuration and to assess the payoff of advanced engine technologies applicable to the time frame of the late 1970s to the mid 1980s. An engine parametric study phase examines major cycle trends on the basis of aircraft economics. This is followed by the preliminary design of two advanced mixed exhaust turbofan engines pointed at two different technology levels (1970 and 1985 commercial certification for engines No. 1 and No. 2, respectively). The economic penalties of environmental constraints - noise and exhaust emissions - are assessed. The highest specific thrust engine (lowest bypass ratio for a given core technology) achievable with a single-stage fan yields the best economics for a Mach 0.95 - 0.98 aircraft and can meet the noise objectives specified, but with significant economic penalties. Advanced technologies which would allow high temperature and cycle pressure ratios to be used effectively are shown to provide significant improvement in mission performance which can partially offset the economic penalties incurred to meet lower noise goals. Advanced technology needs are identified; and, in particular, the initiation of an integrated fan and inlet aero/acoustic program is recommended.
1977-11-01
residual unbaiance. Mass production experience and availability of rotary piston engines -type WANKEL- refer basically to the automobile industry...production air cooled automobile engine in standard form can be ruled out on a specific weight basis. 4. In modified form, as used in many light aircr: Ct...the air cooled automobile engine appears to be a possibility. Availability, lcw initial cost; and good specific fuel consumption could make the unit
Studying the Accuracy of Software Process Elicitation: The User Articulated Model
ERIC Educational Resources Information Center
Crabtree, Carlton A.
2010-01-01
Process models are often the basis for demonstrating improvement and compliance in software engineering organizations. A descriptive model is a type of process model describing the human activities in software development that actually occur. The purpose of a descriptive model is to provide a documented baseline for further process improvement…
From Apprentice to Construction Manager and beyond: Developing a Talent Pipeline
ERIC Educational Resources Information Center
McGettingan, Eamonn; O'Neill, Donal
2009-01-01
Purpose: The purpose of this paper is to outline the approach taken within Kentz Engineers and Constructors to develop electrical technicians and other apprentices on an international basis. Design/methodology/approach: The approach adopted is that of a case study which describes activities and processes within the college and the rationale behind…
Stateless Programming as a Motif for Teaching Computer Science
ERIC Educational Resources Information Center
Cohen, Avi
2004-01-01
With the development of XML Web Services, the Internet could become an integral part of and the basis for teaching computer science and software engineering. The approach has been applied to a university course for students studying introduction to computer science from the point of view of software development in a stateless, Internet…
Evaluation of Final Examination Papers in Engineering: A Case Study Using Bloom's Taxonomy
ERIC Educational Resources Information Center
Swart, A. J.
2010-01-01
Questions are used to obtain information, stimulate thinking, and redirect reasoning. Academics in higher education use questions on a daily basis to stimulate thinking and reasoning in students. Final examination papers are used by academics to assess the retention and application skills of students. The assumption, however, exists that questions…
NASA Astrophysics Data System (ADS)
Solnyshkova, Olga; Makarikhina, Inna
2017-10-01
Prerequisites for students’ professional communication elements forming on the base of civil engineering universities are investigated in the article. Students’ professional communication elements must be used in their future professional activities. The workshop creative experience of interactive electronic educational resources development during the study possesses of geodetic disciplines on the basis of University of Architecture and Civil Engineering (Siberia) is described. The stages of students’ processional communication formation in the process of interactive electronic educational resources creation by students and teachers are proposed. The offers to increase the efficiency of professional communication elements formation for students in the development of interactive electronic educational resources within the student creative workshop were made.
46 CFR 50.01-15 - Scope of regulations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... choice of materials for machinery, boilers, pressure vessels, safety valves, and piping systems upon which safety of life is dependent. (b) Since this subchapter contains the marine engineering details, it... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING GENERAL PROVISIONS Basis and...
46 CFR 50.01-15 - Scope of regulations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... choice of materials for machinery, boilers, pressure vessels, safety valves, and piping systems upon which safety of life is dependent. (b) Since this subchapter contains the marine engineering details, it... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING GENERAL PROVISIONS Basis and...
46 CFR 50.01-15 - Scope of regulations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... choice of materials for machinery, boilers, pressure vessels, safety valves, and piping systems upon which safety of life is dependent. (b) Since this subchapter contains the marine engineering details, it... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING GENERAL PROVISIONS Basis and...
46 CFR 50.01-15 - Scope of regulations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... choice of materials for machinery, boilers, pressure vessels, safety valves, and piping systems upon which safety of life is dependent. (b) Since this subchapter contains the marine engineering details, it... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING GENERAL PROVISIONS Basis and...
46 CFR 50.01-15 - Scope of regulations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... choice of materials for machinery, boilers, pressure vessels, safety valves, and piping systems upon which safety of life is dependent. (b) Since this subchapter contains the marine engineering details, it... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING GENERAL PROVISIONS Basis and...
Uncertainty Management in Urban Water Engineering Adaptation to Climate Change
Current water resource planning and engineering assume a stationary climate, in which the observed historical water flow rate and water quality variations are often used to define the technical basis. When the non-stationarity is considered, however, climate change projection co...
Principles of Sociology in Systems Engineering
NASA Technical Reports Server (NTRS)
Watson, Michael D.; Andrews, James G.; Larsen, Jordan A.
2017-01-01
Systems engineering involves both the integration of the system and the integration of the disciplines which develop and operate the system. Integrating the disciplines is a sociological effort to bring together different groups, often with different terminology, to achieve a common goal, the system. The focus for the systems engineer is information flow through the organization, between the disciplines, to ensure the system is developed and operated with all relevant information informing system decisions. Robert K. Merton studied the sociological principles of the sciences and the sociological principles he developed apply to systems engineering. Concepts such as specification of ignorance, common terminology, opportunity structures, role-sets, and the reclama (reconsideration) process are all important sociological approaches that should be employed by the systems engineer. In bringing the disciplines together, the systems engineer must also be wary of social ambivalence, social anomie, social dysfunction, insider-outsider behavior, unintended consequences, and the self-fulfilling prophecy. These sociological principles provide the systems engineer with key approaches to manage the information flow through the organization as the disciplines are integrated and share their information. This also helps identify key sociological barriers to information flow through the organization. This paper will discuss this theoretical basis for the application of sociological principles to systems engineering.
Photographic characterization of spark-ignition engine fuel injectors
NASA Technical Reports Server (NTRS)
Evanich, P. L.
1978-01-01
Manifold port fuel injectors suitable for use in general aviation spark-ignition engines were evaluated qualitatively on the basis of fuel spray characteristics. Photographs were taken at various fuel flow rates or pressure levels. Mechanically and electronically operated pintle injectors generally produced the most atomization. The plain-orifice injectors used on most fuel-injected general aviation engines did not atomize the fuel when sprayed into quiescent air.
Interoperability in the e-Government Context
2012-01-01
Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center. Any opinions...Hanscom AFB, MA 01731-2125 NO WARRANTY THIS CARNEGIE MELLON UNIVERSITY AND SOFTWARE ENGINEERING INSTITUTE MATERIAL IS FURNISHED ON AN “AS-IS” BASIS... Software Engineering Institute at permission@sei.cmu.edu. * These restrictions do not apply to U.S. government entities. CMU/SEI-2011-TN-014 | i Table
23 CFR 635.411 - Material or product selection.
Code of Federal Regulations, 2010 CFR
2010-04-01
... Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS... is used for research or for a distinctive type of construction on relatively short sections of road... quality and equally acceptable on the basis of engineering analysis and the anticipated prices for the...
23 CFR 635.411 - Material or product selection.
Code of Federal Regulations, 2011 CFR
2011-04-01
... Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS... is used for research or for a distinctive type of construction on relatively short sections of road... quality and equally acceptable on the basis of engineering analysis and the anticipated prices for the...
Uncertainty Management in Urban Water Engineering Adaptation to Climate Change - abstract
Current water resource planning and engineering assume a stationary climate, in which the observed historical water flow rate and water quality variations are often used to define the technical basis. When the non-stationarity is considered, however, climate change projection co...
NASA Astrophysics Data System (ADS)
Yang, Yanchao; Jiang, Hong; Liu, Congbin; Lan, Zhongli
2013-03-01
Cognitive radio (CR) is an intelligent wireless communication system which can dynamically adjust the parameters to improve system performance depending on the environmental change and quality of service. The core technology for CR is the design of cognitive engine, which introduces reasoning and learning methods in the field of artificial intelligence, to achieve the perception, adaptation and learning capability. Considering the dynamical wireless environment and demands, this paper proposes a design of cognitive engine based on the rough sets (RS) and radial basis function neural network (RBF_NN). The method uses experienced knowledge and environment information processed by RS module to train the RBF_NN, and then the learning model is used to reconfigure communication parameters to allocate resources rationally and improve system performance. After training learning model, the performance is evaluated according to two benchmark functions. The simulation results demonstrate the effectiveness of the model and the proposed cognitive engine can effectively achieve the goal of learning and reconfiguration in cognitive radio.
Investigation of lubricants under boundary friction
NASA Technical Reports Server (NTRS)
Heidebroek, E; Pietsch, E
1942-01-01
Numerous observations of such lubrication processes within range of boundary friction on journal bearings and gear tooth profiles have strengthened the supposition that it should be possible to study the attendant phenomena with engineering methods and equipment. These considerations formed the basis of the present studies, which have led to the discovery of relations governing the suitability of bearing surfaces and the concept of "lubricating quality."
Trade-off results and preliminary designs of Near-Term Hybrid Vehicles
NASA Technical Reports Server (NTRS)
Sandberg, J. J.
1980-01-01
Phase I of the Near-Term Hybrid Vehicle Program involved the development of preliminary designs of electric/heat engine hybrid passenger vehicles. The preliminary designs were developed on the basis of mission analysis, performance specification, and design trade-off studies conducted independently by four contractors. THe resulting designs involve parallel hybrid (heat engine/electric) propulsion systems with significant variation in component selection, power train layout, and control strategy. Each of the four designs is projected by its developer as having the potential to substitute electrical energy for 40% to 70% of the petroleum fuel consumed annually by its conventional counterpart.
NASA Astrophysics Data System (ADS)
Andreev, Vladimir
2018-03-01
The paper deals with the problem of determining the stress state of the pressure vessel (PV) with considering the concrete temperature inhomogeneity. Such structures are widely used in heat power engineering, for example, in nuclear power engineering. The structures of such buildings are quite complex and a comprehensive analysis of the stress state in them can be carried out either by numerical or experimental methods. However, a number of fundamental questions can be solved on the basis of simplified models, in particular, studies of the effect on the stressed state of the inhomogeneity caused by the temperature field.
NASA Technical Reports Server (NTRS)
Hawkins, J. E.
1980-01-01
A 0.15 scale model of a proposed conformal variable-ramp inlet for the Multirole Fighter was tested from Mach 0.8 to 2.2 at a wide range of angles of attack and sideslip. Inlet ramp angle was varied to optimize ramp angle as a function of engine airflow, Mach number, angle of attack, and angle of sideslip. Several inlet configuration options were investigated to study their effects on inlet operation and to establish the final flight configuration. These variations were cowl sidewall cutback, cowl lip bluntness, boundary layer bleed, and first-ramp leading edge shape. Diagnostic and engine face instrumentation were used to evaluate inlet operation at various inlet stations and at the inlet/engine interface. Pressure recovery and stability of the inlet were satisfactory for the proposed application. On the basis of an engine stability audit of the worst-case instantaneous distortion patterns, no inlet/engine compatibility problems are expected for normal operations.
Can Diversity in the Undergraduate Engineering Population BE Enhanced Through Curricular Change?
NASA Astrophysics Data System (ADS)
Busch-Vishniac, Ilene J.; Jarosz, Jeffrey P.
The lack of diversity in the engineering workforce is a persistent problem, with no signs of pending improvement. The situation continues despite a serious technical workforce shortage in the United States. Efforts to promote diversity in the student body in U.S. engineering schools, such as industrial partnerships, academic services, and the establishment of social networks, have produced modest gains. The authors intend to pursue a distinctly different approach to the problem of encouraging a diverse engineering student population, one that focuses on the curriculum. This study reviews curricular innovations attempted to date as a basis for rebuilding the undergraduate engineering curriculum from the ground up. The goal is to produce a curriculum that retains the salient technical material but enhances the link between fundamentals and applications, reduces critical path lengths in the course sequence, introduces team experiences into all courses, and creates an atmosphere of inclusion rather than exclusion. The new curriculum will require trial, assessment, and revision before it is ready for adoption.
NASA Astrophysics Data System (ADS)
González, M. R.; Lambán, M. P.
2012-04-01
This paper presents the result of designing the subject Quality Engineering and Security of the Product, belonging to the Degree of Engineering in Industrial Design and Product Development, on the basis of the case methodology. Practical sessions of this subject are organized using the whole documents of the Quality System Management of the virtual company BeaLuc S.A.
Main drive selection for the Windstorm Simulation Center
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lacy, J.M.; Earl, J.S.
1998-02-01
Operated by the Partnership for Natural Disaster Reduction, the Windstorm Simulation Center (WSC) will be a structural test center dedicated to studying the performance of civil structural systems subjected to hurricanes, tornadoes, and other storm winds. Within the WSC, a bank of high-power fans, the main drive, will produce the high velocity wind necessary to reproduce these storms. Several options are available for the main drive, each with advantages and liabilities. This report documents a study to identify and evaluate all candidates available, and to select the most promising system such that the best possible combination of real-world performance attributesmore » is achieved at the best value. Four broad classes of candidate were identified: electric motors, turbofan aircraft engines, turboshaft aircraft engines, and turboshaft industrial engines. Candidate systems were evaluated on a basis of technical feasibility, availability, power, installed cost, and operating cost.« less
Miralpeix, Bruna; Sabalza, Maite; Twyman, Richard M; Capell, Teresa; Christou, Paul
2014-02-01
The do-it-yourself patent search is a useful alternative to professional patent analysis particularly in the context of publicly funded projects where funds for IP activities may be limited. As a case study, we analysed patents related to the engineering of terpenoid indole alkaloid (TIA) metabolism in plants. We developed a focused search strategy to remove redundancy and reduce the workload without missing important and relevant patents. This resulted in the identification of approximately 50 key patents associated with TIA metabolic engineering in plants, which could form the basis of a more detailed freedom-to-operate analysis. The structural elements of this search strategy could easily be transferred to other contexts, making it a useful generic model for publicly funded research projects. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.
Bioreactor System Using Noninvasive Imaging and Mechanical Stretch for Biomaterial Screening
Kluge, Jonathan A.; Leisk, Gary G.; Cardwell, Robyn S.; Fernandes, Alexander P.; House, Michael; Ward, Andrew; Dorfmann, A. Luis; Kaplan, David L.
2012-01-01
Screening biomaterial and tissue systems in vitro, for guidance of performance in vivo, remains a major requirement in the field of tissue engineering. It is critical to understand how culture stimulation affects both tissue construct maturation and function, with the goal of eliminating resource-intensive trial-and-error screening and better matching specifications for various in vivo needs. We present a multifunctional and robust bioreactor design that addresses this need. The design enables a range of mechanical inputs, durations, and frequencies to be applied in coordination with noninvasive optical assessments. A variety of biomaterial systems, including micro- and nano-fiber and porous sponge biomaterials, as well as cell-laden tissue engineering constructs were used in validation studies in order to demonstrate the versatility and utility of this new bioreactor design. The silk-based biomaterials highlighted in these studies offered several unique optical signatures for use in label-free nondestructive imaging that allowed for sequential profiling. Both short- and long-term culture studies were conducted to evaluate several practical scenarios of usage: on a short-term basis, we demonstrate that construct cellularity can be monitored by usage of nonpermanent dyes; on a more long-term basis, we show that cell ingrowth can be monitored by GFP-labeling and construct integrity probed with concurrent load/displacement data. The ability to nondestructively track cells, biomaterials, and new matrix formation without harvesting designated samples at each time point will lead to less resource-intensive studies and should enhance our understanding and the discovery of biomaterial designs related to functional tissue engineering. PMID:21298345
Code of Federal Regulations, 2014 CFR
2014-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... subclassification of an engine family which can be described on the basis of gross power, emission control system... population of an engine family for emission testing. [59 FR 31335, June 17, 1994. Redesignated at 63 FR 56996...
Code of Federal Regulations, 2013 CFR
2013-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... subclassification of an engine family which can be described on the basis of gross power, emission control system... population of an engine family for emission testing. [59 FR 31335, June 17, 1994. Redesignated at 63 FR 56996...
Code of Federal Regulations, 2012 CFR
2012-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... subclassification of an engine family which can be described on the basis of gross power, emission control system... population of an engine family for emission testing. [59 FR 31335, June 17, 1994. Redesignated at 63 FR 56996...
Code of Federal Regulations, 2011 CFR
2011-07-01
... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... subclassification of an engine family which can be described on the basis of gross power, emission control system... population of an engine family for emission testing. [59 FR 31335, June 17, 1994. Redesignated at 63 FR 56996...
Quality Assurance in Engineering Education: Comparison of Accreditation Schemes and ISO 9001.
ERIC Educational Resources Information Center
Karapetrovic, Stanislav; Rajamani, Divakar; Willborn, Walter
1998-01-01
Outlines quality assurance schemes for distance-education technologies that are based on the ISO 9000 family of international quality-assurance standards. Argues that engineering faculties can establish such systems on the basis of and integrated with accreditation schemes. Contains 34 references. (DDR)
Holding Accountability Models Accountable
ERIC Educational Resources Information Center
Pyatte, Jeff A.
1974-01-01
This article provides an accurate account of the history of the Texarkana Project, the first attempt to demonstrate accountability in education by using the engineering model. Using the average per pupil expenditure as a basis for comparison, the cost of engineering in Texarkana is shown to be very high. (Author)
The same properties of engineered nanomaterials (ENMs) that are the basis for their many novel applications also raise important issues related to their environmental impact. ENMs might not behave similarly in the environment to the dissolved or solid forms of the chemicals from ...
Guide to Special Information in Scientific and Engineering Journals.
ERIC Educational Resources Information Center
Harris, Mary Elizabeth
This annotated bibliography lists 203 special features or special issues of science and technology periodicals with emphasis on compilations of information that appear in periodicals on a regular basis. Subjects covered in the guide include aeronautics, air-conditioning and refrigeration engineering, astronomy, automobiles, biology, botany,…
NASA Astrophysics Data System (ADS)
Kersten, Jennifer Anna
In recent years there has been increasing interest in engineering education at the K-12 level, which has resulted in states adopting engineering standards as a part of their academic science standards. From a national perspective, the basis for research into engineering education at the K-12 level is the belief that it is of benefit to student learning, including to "improve student learning and achievement in science and mathematics; increase awareness of engineering and the work of engineers; boost youth interest in pursuing engineering as a career; and increase the technological literacy of all students" (National Research Council, 2009a, p. 1). The above has led to a need to understand how teachers are currently implementing engineering education in their classrooms. High school physics teachers have a history of implementing engineering design projects in their classrooms, thus providing an appropriate setting to look for evidence of quality engineering education at the high school level. Understanding the characteristics of quality engineering integration can inform curricular and professional development efforts for teachers asked to implement engineering in their classrooms. Thus, the question that guided this study is: How, and to what extent, do physics teachers represent quality engineering in a physics unit focused on engineering? A case study research design was implemented for this project. Three high school physics teachers were participants in this study focused on the integration of engineering education into the physics classroom. The data collected included observations, interviews, and classroom documents that were analyzed using the Framework for Quality K-12 Engineering Education (Moore, Glancy et al., 2013). The results provided information about the areas of the K-12 engineering framework addressed during these engineering design projects, and detailed the quality of these lesson components. The results indicate that all of the design projects contained components of the indicators central to engineering education, although with varied degrees of success. In addition, each design project contained aspects important to the development of students' understanding of engineering and that promote important professional skills used by engineers. The implications of this work are discussed at the teacher, school, professional development, and policy levels.
Enhancing Adaptability of U.S. Military Forces. Part A: Main Report
2011-01-01
virtual ...Research and Engineering, Rapid Capability Fielding Toolbox Study, stated that virtual environment tools can...the “approved” basis for requirements is divorced from reality , and setting system
STEM@1000mph: Developing Open Educational Resources in a Live Engineering Project
ERIC Educational Resources Information Center
Lanham, John; Howard, Yvonne; Drew, Ben; Johns, Dan
2013-01-01
Higher education institutions are recognising the clear benefits of open educational resources, and academics are engaging with the development of these resources. This paper presents a case study of OERs being developed using the live, current BloodhoundSSC world land speed record project as a basis. The paper outlines the rationale for the…
NASA Technical Reports Server (NTRS)
Kuehl, H.
1947-01-01
The basic principles of the control of TL ongincs are developed on .the basis of a quantitative investigation of the behavior of these behavior under various operating conditions with particular consideration of the simplifications pormissible in each case. Various possible means of control of jet engines are suggested and are illustrated by schematic designs.
Introduction to bioengineering: melding of engineering and biological sciences.
Shoureshi, Rahmat A
2005-04-01
Engineering has traditionally focused on the external extensions of organisms, such as transportation systems, high-rise buildings, and entertainment systems. In contrast, bioengineering is concerned with inward processes of biologic organisms. Utilization of engineering principles and techniques in the analysis and solution of problems in medicine and biology is the basis for bioengineering. This article discusses subspecialties in bioengineering and presents examples of projects in this discipline.
Weight propagation and equivalent horsepower for alternate-engined cars
NASA Technical Reports Server (NTRS)
Klose, G. J.; Kurtz, D. W.
1978-01-01
In order to evaluate properly the consequences of replacing conventional Otto-cycle engines with alternate power systems, comparisons must be carried out at the vehicle level with functionally equivalent cars. This paper presents the development and application of a procedure for establishing equivalent vehicles. A systematic weight propagation methodology, based on detailed weight breakdowns and influence factors, yields the vehicle weight impacts due to changes in engine weight and power. Performance-matching criteria, utilizing a vehicle simulation program, are then employed to establish Otto-engine-equivalent vehicles, whose characteristics can form the basis for alternative engine evaluations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Savage, J.W.
1983-03-10
A human factors engineering design review/audit of the Waterford-3 control room was performed at the site on May 10 through May 13, 1982. The report was prepared on the basis of the HFEB's review of the applicant's Preliminary Human Engineering Discrepancy (PHED) report and the human factors engineering design review performed at the site. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. The review team was assisted by consultants from Lawrence Livermore National Laboratory (University of California), Livermore, California.
Genome Engineering for Personalized Arthritis Therapeutics.
Adkar, Shaunak S; Brunger, Jonathan M; Willard, Vincent P; Wu, Chia-Lung; Gersbach, Charles A; Guilak, Farshid
2017-10-01
Arthritis represents a family of complex joint pathologies responsible for the majority of musculoskeletal conditions. Nearly all diseases within this family, including osteoarthritis, rheumatoid arthritis, and juvenile idiopathic arthritis, are chronic conditions with few or no disease-modifying therapeutics available. Advances in genome engineering technology, most recently with CRISPR-Cas9, have revolutionized our ability to interrogate and validate genetic and epigenetic elements associated with chronic diseases such as arthritis. These technologies, together with cell reprogramming methods, including the use of induced pluripotent stem cells, provide a platform for human disease modeling. We summarize new evidence from genome-wide association studies and genomics that substantiates a genetic basis for arthritis pathogenesis. We also review the potential contributions of genome engineering in the development of new arthritis therapeutics. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Evans, Alison B.
1991-01-01
A study was conducted to determine the effects of seventh-stage compressor bleed on the performance of the F100 afterburning turbofan engine. The effects of bleed on thrust, specific fuel consumption, fan turbine inlet temperature, bleed total pressure, and bleed total temperature were obtained from the engine manufacturer's status deck computer simulation. These effects were determined for power settings of intermediate, partial afterburning, and maximum afterburning for Mach numbers between 0.6 and 2.2 and for altitudes of 30,000, 40,000, and 50,000 ft. It was found that thrust loss and specific fuel consumption increase were approximately linear functions of bleed flow and, based on a percent-thrust change basis, were approximately independent of power setting.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-01
... compete for high tech employees, and in particular specialized computer science and engineering talent on the basis of salaries, benefits, and career opportunities. In recent years, talented computer... Venue 4. Each Defendant hires specialized computer engineers and scientists throughout the United States...
Development of a Thinking Programme for Engineering Students
ERIC Educational Resources Information Center
Tan, Oon-Seng
2006-01-01
The challenge of preparing engineering graduates for a fast-changing work environment calls for the development of thinking programmes. A psychological basis was used to develop the tenets of the approach. The Cognitive Modifiability Intervention (CMI) was rationalized and conceived as a corollary of observations of learning scenarios and an…
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Materials. 33.15 Section 33.15 Aeronautics... STANDARDS: AIRCRAFT ENGINES Design and Construction; General § 33.15 Materials. The suitability and durability of materials used in the engine must— (a) Be established on the basis of experience or tests; and...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Materials. 33.15 Section 33.15 Aeronautics... STANDARDS: AIRCRAFT ENGINES Design and Construction; General § 33.15 Materials. The suitability and durability of materials used in the engine must— (a) Be established on the basis of experience or tests; and...
76 FR 50275 - Guidance for the Assessment of Beyond-Design-Basis Aircraft Impacts
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-12
...: Mekonen M. Bayssie, Regulatory Guide Development Branch, Division of Engineering, Office of Nuclear... e-mail to [email protected] . SUPPLEMENTARY INFORMATION: I. Introduction The Nuclear..., Division of Engineering, Office of Nuclear Regulatory Research. [FR Doc. 2011-20513 Filed 8-11-11; 8:45 am...
An Electronic Web-Based Assessment System
ERIC Educational Resources Information Center
Petrova, Raina; Tibrewal, Abhilasha; Sobh, Tarek M.
2006-01-01
In keeping with the outcome-based assessment outlined by ABET's Education Criteria 2000, the School of Engineering at the University of Bridgeport has defined fifteen general student outcomes for its computer engineering program. These outcomes form the basis of its instructional program and assessment activities. In assessing and monitoring the…
Gálvez, Jorge A; Pappas, Janine M; Ahumada, Luis; Martin, John N; Simpao, Allan F; Rehman, Mohamed A; Witmer, Char
2017-10-01
Venous thromboembolism (VTE) is a potentially life-threatening condition that includes both deep vein thrombosis (DVT) and pulmonary embolism. We sought to improve detection and reporting of children with a new diagnosis of VTE by applying natural language processing (NLP) tools to radiologists' reports. We validated an NLP tool, Reveal NLP (Health Fidelity Inc, San Mateo, CA) and inference rules engine's performance in identifying reports with deep venous thrombosis using a curated set of ultrasound reports. We then configured the NLP tool to scan all available radiology reports on a daily basis for studies that met criteria for VTE between July 1, 2015, and March 31, 2016. The NLP tool and inference rules engine correctly identified 140 out of 144 reports with positive DVT findings and 98 out of 106 negative reports in the validation set. The tool's sensitivity was 97.2% (95% CI 93-99.2%), specificity was 92.5% (95% CI 85.7-96.7%). Subsequently, the NLP tool and inference rules engine processed 6373 radiology reports from 3371 hospital encounters. The NLP tool and inference rules engine identified 178 positive reports and 3193 negative reports with a sensitivity of 82.9% (95% CI 74.8-89.2) and specificity of 97.5% (95% CI 96.9-98). The system functions well as a safety net to screen patients for HA-VTE on a daily basis and offers value as an automated, redundant system. To our knowledge, this is the first pediatric study to apply NLP technology in a prospective manner for HA-VTE identification.
Impact of the injection dose of exhaust gases, on work parameters of combustion engine
NASA Astrophysics Data System (ADS)
Marek, W.; Śliwiński, K.
2016-09-01
This article is another one from the series in which were presented research results indicated the possible areas of application of the pneumatic injection using hot combustion gases proposed by Professor Jarnuszkiewicz. This publication present the results of the control system of exhaust gas recirculation. The main aim of this research was to determine the effect of exhaust gas recirculation to the operating parameters of the internal combustion engine on the basis of laboratory measurements. All measurements were performed at a constant engine speed. These conditions correspond to the operation of the motor operating an electrical generator. The study was conducted on the four-stroke two-cylinder engine with spark ignition. The study were specifically tested on the air injection system and therefore the selection of the rotational speed was not bound, as in conventional versions of operating parameters of the electrical machine. During the measurement there were applied criterion which used power control corresponding to the requirements of load power, at minimal values of engine speed. Recirculation value determined by the following recurrent position control valve of the injection doses inflator gas for pneumatic injection system. They were studied and recorded, the impact of dose of gases recirculation to the operating and ecological engine parameters such as power, torque, specific fuel consumption, efficiency, air fuel ratio, exhaust gas temperature and nitrogen oxides and hydrocarbons.
Digital design of scaffold for mandibular defect repair based on tissue engineering*
Liu, Yun-feng; Zhu, Fu-dong; Dong, Xing-tao; Peng, Wei
2011-01-01
Mandibular defect occurs more frequently in recent years, and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic flaws. Tissue engineering, which is a hot research field of biomedical engineering, provides a new direction for mandibular defect repair. As the basis and key part of tissue engineering, scaffolds have been widely and deeply studied in regards to the basic theory, as well as the principle of biomaterial, structure, design, and fabrication method. However, little research is targeted at tissue regeneration for clinic repair operations. Since mandibular bone has a special structure, rather than uniform and regular structure in existing studies, a methodology based on tissue engineering is proposed for mandibular defect repair in this paper. Key steps regarding scaffold digital design, such as external shape design and internal microstructure design directly based on triangular meshes are discussed in detail. By analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping, the feasibility and effectiveness of the proposed methodology are properly verified. More works about mechanical and biological improvements need to be done to promote its clinical application in future. PMID:21887853
Digital design of scaffold for mandibular defect repair based on tissue engineering.
Liu, Yun-feng; Zhu, Fu-dong; Dong, Xing-tao; Peng, Wei
2011-09-01
Mandibular defect occurs more frequently in recent years, and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic flaws. Tissue engineering, which is a hot research field of biomedical engineering, provides a new direction for mandibular defect repair. As the basis and key part of tissue engineering, scaffolds have been widely and deeply studied in regards to the basic theory, as well as the principle of biomaterial, structure, design, and fabrication method. However, little research is targeted at tissue regeneration for clinic repair operations. Since mandibular bone has a special structure, rather than uniform and regular structure in existing studies, a methodology based on tissue engineering is proposed for mandibular defect repair in this paper. Key steps regarding scaffold digital design, such as external shape design and internal microstructure design directly based on triangular meshes are discussed in detail. By analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping, the feasibility and effectiveness of the proposed methodology are properly verified. More works about mechanical and biological improvements need to be done to promote its clinical application in future.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-03-17
This report summarizes all work for the Energy Survey of Army Industrial Facilities, Energy Engineering Analysis Program (EEAP) at the Western Area Demilitarization Facility (WADF) of the Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada, authorized under Contract No. DACA03-92-C-0155 with the U.S. Army Corps of Engineers, Sacramento District, California. The purpose of this energy survey is to develop a set of projects and actions that will reduce energy consumption and operating costs of selected facilities at the WADF. A preliminary inspection of facilities at WADF by Keller Gannon that identified potential retrofit opportunities was submitted as the EEAP Study andmore » Criteria Review in December 1993. This document formed the basis of the Detailed Scope of Work for this study. Facilities included in the survey and study, together with operational status, are listed in Table 1 - 1. The complete scope of work appears in Appendix.« less
Utilization of CAD/CAE for concurrent design of structural aircraft components
NASA Technical Reports Server (NTRS)
Kahn, William C.
1993-01-01
The feasibility of installing the Stratospheric Observatory for Infrared Astronomy telescope (named SOFIA) into an aircraft for NASA astronomy studies is investigated using CAD/CAE equipment to either design or supply data for every facet of design engineering. The aircraft selected for the platform was a Boeing 747, chosen on the basis of its ability to meet the flight profiles required for the given mission and payload. CAD models of the fuselage of two of the aircraft models studied (747-200 and 747 SP) were developed, and models for the component parts of the telescope and subsystems were developed by the various concurrent engineering groups of the SOFIA program, to determine the requirements for the cavity opening and for design configuration. It is noted that, by developing a plan to use CAD/CAE for concurrent engineering at the beginning of the study, it was possible to produce results in about two-thirds of the time required using traditional methods.
Radial basis function neural networks applied to NASA SSME data
NASA Technical Reports Server (NTRS)
Wheeler, Kevin R.; Dhawan, Atam P.
1993-01-01
This paper presents a brief report on the application of Radial Basis Function Neural Networks (RBFNN) to the prediction of sensor values for fault detection and diagnosis of the Space Shuttle's Main Engines (SSME). The location of the Radial Basis Function (RBF) node centers was determined with a K-means clustering algorithm. A neighborhood operation about these center points was used to determine the variances of the individual processing notes.
National Aeronautics Research, Development, Test and Evaluation (RDT&E) Infrastructure Plan
2011-01-01
addressed in the National Aeronautics R&D Plan, identi- fying unnecessary redundancy solely on the basis of infrastructure required to support H H13 ...near, mid, and far terms, and impact not only scramjet propulsion systems, but potential turbine-based combined cycle systems as well. Turbine Engine...Icing Test Facilities A greater understanding of the impact that icing conditions have on turbine engine opera- tions is needed to develop enhanced
NASA Technical Reports Server (NTRS)
Snyder, Christopher A.
2014-01-01
A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nautical miles at 300 knots, with vertical takeoff and landing capability. This paper explores gas turbine component performance and cycle parameters to quantify performance gains possible for additional improvements in component and material performance beyond those identified in previous LCTR2 propulsion studies and to identify additional research areas. The vehicle-level characteristics from this advanced technology generation 2 propulsion architecture will help set performance levels as additional propulsion and power systems are conceived to meet ever-increasing requirements for mobility and comfort, while reducing energy use, cost, noise and emissions. The Large Civil Tiltrotor vehicle and mission will be discussed as a starting point for this effort. A few, relevant engine and component technology studies, including previous LCTR2 engine study results will be summarized to help orient the reader on gas turbine engine architecture, performance and limitations. Study assumptions and methodology used to explore engine design and performance, as well as assess vehicle sizing and mission performance will then be discussed. Individual performance for present and advanced engines, as well as engine performance effects on overall vehicle size and mission fuel usage, will be given. All results will be summarized to facilitate understanding the importance and interaction of various component and system performance on overall vehicle characteristics.
NASA Technical Reports Server (NTRS)
Haering, E. A., Jr.; Burcham, F. W., Jr.
1984-01-01
A simulation study was conducted to optimize minimum time and fuel consumption paths for an F-15 airplane powered by two F100 Engine Model Derivative (EMD) engines. The benefits of using variable stall margin (uptrim) to increase performance were also determined. This study supports the NASA Highly Integrated Digital Electronic Control (HIDEC) program. The basis for this comparison was minimum time and fuel used to reach Mach 2 at 13,716 m (45,000 ft) from the initial conditions of Mach 0.15 at 1524 m (5000 ft). Results were also compared to a pilot's estimated minimum time and fuel trajectory determined from the F-15 flight manual and previous experience. The minimum time trajectory took 15 percent less time than the pilot's estimate for the standard EMD engines, while the minimum fuel trajectory used 1 percent less fuel than the pilot's estimate for the minimum fuel trajectory. The F-15 airplane with EMD engines and uptrim, was 23 percent faster than the pilot's estimate. The minimum fuel used was 5 percent less than the estimate.
Using CASE tools to write engineering specifications
NASA Astrophysics Data System (ADS)
Henry, James E.; Howard, Robert W.; Iveland, Scott T.
1993-08-01
There are always a wide variety of obstacles to writing and maintaining engineering documentation. To combat these problems, documentation generation can be linked to the process of engineering development. The same graphics and communication tools used for structured system analysis and design (SSA/SSD) also form the basis for the documentation. The goal is to build a living document, such that as an engineering design changes, the documentation will `automatically' revise. `Automatic' is qualified by the need to maintain textual descriptions associated with the SSA/SSD graphics, and the need to generate new documents. This paper describes a methodology and a computer aided system engineering toolset that enables a relatively seamless transition into document generation for the development engineering team.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-09-01
The project is a significant part of Hawthorne Army Ammunition Depot`s effort to achieve a 20-percent reduction in energy consumption by FY2000 versus FY1985 baseline levels. The project will also assure that heating services are provided to Industrial Area facilities on a continuing basis, supporting mission requirements.
Fuel/Engine/Airframe Trade-Off Study.
1980-09-01
calculated: Prce CgeQl Using Diese Pices Lw l- JP-8 0.67 1.01 Using Heating Oil Prices JP-4 0.0 0.0 JP-8 -0.81 -1.23 On a percentage basis, these price...36. Graham, S. C., J. B. Homer, Jr., and L. L. ,1. Rosenfeld. "The Formation and Coagulation of Soot Aerosols Generated by the Pyrolysis of Aromatic
ERIC Educational Resources Information Center
Amorim, Gabriela; Balestrassi, Pedro; Paiva, Anderson; Gottzandt, Isabella
2014-01-01
The methodology used in this study was action-research and the considered activity is been applied successfully for at least five years to undergraduate and to master classes for Industrial Engineering students in Brazil. It showed a significant result in both cases, providing the basis for the deepening in the subject in further lessons.…
Uncertainty Analysis for DAM Projects.
1987-09-01
overwhelming majority of articles published on the use of statistical methodology for geotechnical engineering focus on performance predictions and design ...Results of the present study do not support the adoption of more esoteric statistical procedures except on a special case basis or in research ...influence that recommended statistical procedures might have had on the Carters Project, had they been applied during planning and design phases
Experimental study on the connection property of full-scale composite member
NASA Astrophysics Data System (ADS)
Panpan, Cao; Qing, Sun
2018-01-01
The excellent properties of composite result in its increasingly application in electric power construction, however there are less experimental studies on full-scale composite member connection property. Full-scale experiments of the connection property between E-glass fiber/epoxy reinforced polymer member and steel casing in practical engineering have been conducted. Based on the axial compression test of the designed specimens, the failure process and failure characteristics were observed, the load-displacement curves and strain distribution of the specimens were obtained. The finite element analysis was used to get the tensile connection strength of the component. The connection property of the components was analyzed to provide basis of the casing connection of GFRP application in practical engineering.
NASA Astrophysics Data System (ADS)
Vaganova, E. V.; Syryamkin, M. V.
2015-11-01
The purpose of the research is the development of evolutionary algorithms for assessments of promising scientific directions. The main attention of the present study is paid to the evaluation of the foresight possibilities for identification of technological peaks and emerging technologies in professional medical equipment engineering in Russia and worldwide on the basis of intellectual property items and neural network modeling. An automated information system consisting of modules implementing various classification methods for accuracy of the forecast improvement and the algorithm of construction of neuro-fuzzy decision tree have been developed. According to the study result, modern trends in this field will focus on personalized smart devices, telemedicine, bio monitoring, «e-Health» and «m-Health» technologies.
40 CFR 63.9345 - What notifications must I submit and when?
Code of Federal Regulations, 2014 CFR
2014-07-01
... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands... apply to you by the dates specified. (b) If you own or operate a new or reconstructed test cell/stand... engine test cell/stand has no additional requirements and explain the basis of the exclusion (for example...
40 CFR 63.9345 - What notifications must I submit and when?
Code of Federal Regulations, 2011 CFR
2011-07-01
... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands... apply to you by the dates specified. (b) If you own or operate a new or reconstructed test cell/stand... engine test cell/stand has no additional requirements and explain the basis of the exclusion (for example...
40 CFR 63.9345 - What notifications must I submit and when?
Code of Federal Regulations, 2012 CFR
2012-07-01
... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands... apply to you by the dates specified. (b) If you own or operate a new or reconstructed test cell/stand... engine test cell/stand has no additional requirements and explain the basis of the exclusion (for example...
40 CFR 63.9345 - What notifications must I submit and when?
Code of Federal Regulations, 2013 CFR
2013-07-01
... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands... apply to you by the dates specified. (b) If you own or operate a new or reconstructed test cell/stand... engine test cell/stand has no additional requirements and explain the basis of the exclusion (for example...
Assessment of a 40-kilowatt stirling engine for underground mining applications
NASA Technical Reports Server (NTRS)
Cairelli, J. E.; Kelm, G. G.; Slaby, J. G.
1982-01-01
An assessment of alternative power souces for underground mining applications was performed. A 40-kW Stirling research engine was tested to evaluate its performance and emission characteristics when operated with helium working gas and diesel fuel. The engine, the test facility, and the test procedures are described. Performance and emission data for the engine operating with helium working gas and diesel fuel are reported and compared with data obtained with hydrogen working gas and unleaded gasoline fuel. Helium diesel test results are compared with the characteristics of current diesel engines and other Stirling engines. External surface temperature data are also presented. Emission and temperature results are compared with the Federal requirements for diesel underground mine engines. The durability potential of Stirling engines is discussed on the basis of the experience gaind during the engine tests.
Conceptual design study of a V/STOL lift fan commercial short haul transport
NASA Technical Reports Server (NTRS)
Knight, R. G.; Powell, W. V., Jr.; Prizlow, J. A.
1973-01-01
Conceptual designs of V/STOL lift fan commercial short haul transport aircraft for the 1980-85 time period were studied to determine their technical and economic feasibility. The engine concepts included both integral and remote fans. The scope of the study included definition of the hover control concept for each propulsion system, aircraft design, mass properties, cruise performance, noise and ride qualities evaluation. Economic evaluation was also studied on the basis of direct-operating costs and route structure.
Conceptual design of a V/STOL lift fan commercial short haul transport
NASA Technical Reports Server (NTRS)
1973-01-01
Conceptual designs of V/STOL lift-fan commercial short-haul transport aircraft for the 1980-85 time period were studied to determine their technical and economic feasibility. Engine concepts studied included both integral remote fans. The scope of the study included definition of the hover control concept for each propulsion system, aircraft design, aircraft mass properties, cruise performance noise, and ride qualities evaluation. Economic evaluation was also studied on a basis of direct operating cost and route structure.
Mithras Studies of the Boundary Between Open and Closed Field Lines.
1994-01-31
I ¸ . . A- : - Final Report • March 1995 MITHRAS STUDIES OF THE BOUNDARY BETWEEN OPEN AND CLOSED FIELD LINES John D. Kelly, Program Manager Richard A...Kelly, Program Manager Richard A. Doe, Research Physicist Geoscience and Engineering Center SRI Project 3245 Prepared for: Department of the Air...characteristic energy, energy flux, and an estimate for upward field-aligned current. On the basis of coordinated radar/optical experiments, Vallance Jones et al
Odukoya, Jonathan A; Popoola, Segun I; Atayero, Aderemi A; Omole, David O; Badejo, Joke A; John, Temitope M; Olowo, Olalekan O
2018-04-01
In Nigerian universities, enrolment into any engineering undergraduate program requires that the minimum entry criteria established by the National Universities Commission (NUC) must be satisfied. Candidates seeking admission to study engineering discipline must have reached a predetermined entry age and met the cut-off marks set for Senior School Certificate Examination (SSCE), Unified Tertiary Matriculation Examination (UTME), and the post-UTME screening. However, limited effort has been made to show that these entry requirements eventually guarantee successful academic performance in engineering programs because the data required for such validation are not readily available. In this data article, a comprehensive dataset for empirical evaluation of entry requirements into engineering undergraduate programs in a Nigerian university is presented and carefully analyzed. A total sample of 1445 undergraduates that were admitted between 2005 and 2009 to study Chemical Engineering (CHE), Civil Engineering (CVE), Computer Engineering (CEN), Electrical and Electronics Engineering (EEE), Information and Communication Engineering (ICE), Mechanical Engineering (MEE), and Petroleum Engineering (PET) at Covenant University, Nigeria were randomly selected. Entry age, SSCE aggregate, UTME score, Covenant University Scholastic Aptitude Screening (CUSAS) score, and the Cumulative Grade Point Average (CGPA) of the undergraduates were obtained from the Student Records and Academic Affairs unit. In order to facilitate evidence-based evaluation, the robust dataset is made publicly available in a Microsoft Excel spreadsheet file. On yearly basis, first-order descriptive statistics of the dataset are presented in tables. Box plot representations, frequency distribution plots, and scatter plots of the dataset are provided to enrich its value. Furthermore, correlation and linear regression analyses are performed to understand the relationship between the entry requirements and the corresponding academic performance in engineering programs. The data provided in this article will help Nigerian universities, the NUC, engineering regulatory bodies, and relevant stakeholders to objectively evaluate and subsequently improve the quality of engineering education in the country.
Energy and Exergy Analysis of a Diesel Engine Fuelled with Diesel and Simarouba Biodiesel Blends
NASA Astrophysics Data System (ADS)
Panigrahi, Nabnit; Mohanty, Mahendra Kumar; Mishra, Sruti Ranjan; Mohanty, Ramesh Chandra
2018-02-01
This article intends to determine the available work and various losses of a diesel engine fuelled with diesel and SB20 (20 % Simarouba biodiesel by volume blended with 80 % diesel by volume). The energy and exergy analysis were carried out by using first law and second law of thermodynamics respectively. The experiments were carried out on a 3.5 kW compression ignition engine. The analysis was conducted on per mole of fuel basis. The energy analysis indicates that about 37.23 and 37.79 % of input energy is converted into the capacity to do work for diesel and SB20 respectively. The exergetic efficiency was 34.8 and 35 % for diesel and Simarouba respectively. Comparative study indicates that the energetic and exergetic performance of SB20 resembles with that of diesel fuel.
Practice in Master Course of Techno-Business Administration as a Techno-Business School
NASA Astrophysics Data System (ADS)
Nakamura, Takashi; Matsuura, Chikako
In this paper, the educational practice of the master course of techno-business administration (MTA) at Nagoya Institute of Technology (NIT) is introduced to propose the practical engineering education at a postgraduate level. MTA was established in 2003 on the basis of hundred years' engineering education at NIT. An objective of this school is to educate engineers to be leaders, entrepreneurs and managers. The practical tuition covers the fields in Industrial Management of Technologies, Core-Technologies and Laboratories work. Among these, the most focused and effective subject is “Case-Study,” in which students are encouraged to simulate business settings using elemental technologies developed by teaching staff. Discussions are made to apply the technology to match the possible markets. This type of experiences certainly motivates the students work and is clearly reflected in their research paper.
Chen, Zhen; Wu, Yao; Huang, Jinhai; Liu, Dehua
2015-12-01
Butanol isomers are important bulk chemicals and promising fuel substitutes. The inevitable toxicity of n-butanol and isobutanol to microbial cells hinders their final titers. In this study, we attempt to engineer Klebsiella pneumoniae for the de novo production of 2-butanol, another butanol isomer which shows lower toxicity than n-butanol and isobutanol. 2-Butanol synthesis was realized by the extension of the native meso-2,3-butanediol synthesis pathway with the introduction of diol dehydratase and secondary alcohol dehydrogenase. By the screening of different secondary alcohol dehydrogenases and diol dehydratases, 320mg/L of 2-butanol was produced by the best engineered K. pneumoniae. The production was increased to 720mg/L by knocking out the ldhA gene and appropriate addition of coenzyme B12. Further improvement of 2-butanol to 1030mg/L was achieved by protein engineering of diol dehydratase. This work lays the basis for the metabolic engineering of microorganism for the production of 2-butanol as potential biofuel. Copyright © 2015 Elsevier Ltd. All rights reserved.
Chinese modify CZ-2/3 rocket boosters, focus on commercial launch market
NASA Astrophysics Data System (ADS)
Covault, C.
1985-07-01
A program underway in the People's Republic of China to modify the Titan-class CZ-2/3 satellite-launch and ICBM boosters is described on the basis of a recent visit to the manufacturing plant in Shanghai. The present two-stage CZ-2 and three-stage CZ-3 can place 5000 lbs in LEO or 3080 lbs in GEO, respectively, and are produced on a custom basis with a delivery time of about 2 yrs. Modifications introduced include 4 x 6-ft fins and a pogo-suppression system for the four-engine first stage and a steel support band for the combustion chamber of the 80-ton-thrust second-stage main engine.
NASA Astrophysics Data System (ADS)
Rosser, Sue V.; Lane, Eliesh O'neil
At the end of a special meeting held at the Massachusetts Institute of Technology in January 2001, a statement released on behalf of the most prestigious U. S. research universities suggested that institutional harriers have prevented viomen from having a level playing field in science and engineering. In 2001, the National Science Foundation initiated a new awards program, ADVANCE, focusing on institutional rather than individual solutions to empower women to participate fully in science and technology. In this study, the authors evaluate survey responses from almost 400 Professional Opportunities for Women in Research and Education awardees from fiscal years 1997 to 2000 to elucidate problems and opportunities identified by female scientists and engineers. Besides other issues, the respondents identified balancing a career and a family as the most significant challenge facing female scientists and engineers today. Institutions must seek to remove or at least lower these and other harriers to attract and retain female scientists and engineers. Grouping the survey responses into four categories forms the basis for four corresponding policy areas, which could be addressed at the institutional level to mitigate the difficulties and challenges currently experienced by female scientists and engineers.
2014-03-01
for Biotechnology, Gurgaon, India (Sep, 2013) by Joel L. Sussman, title: “Molecular Basis of How Nerve Agents through anti- Alzheimer Drugs Function...Molecular Basis of How Nerve Agents through anti- Alzheimer Drugs Function: 3D Structure of Acetylcholinesterase • Florida International University...FIU), Miami, FL (Dec 2013) - Invited Lecture by Joel L. Sussman, title: “Molecular Basis of anti- Alzheimer Drugs & Nerve Agents: 3D Structure of
A Design Basis for Spacecraft Cabin Trace Contaminant Control
NASA Technical Reports Server (NTRS)
Perry, Jay L.
2009-01-01
Successful trace chemical contamination control is one of the components necessary for achieving good cabin atmospheric quality. While employing seemingly simple process technologies, sizing the active contamination control equipment must employ a reliable design basis for the trace chemical load in the cabin atmosphere. A simplified design basis that draws on experience gained from the International Space Station program is presented. The trace chemical contamination control design load refines generation source magnitudes and includes key chemical functional groups representing both engineering and toxicology challenges.
The effect of humidity on engine power at altitude
NASA Technical Reports Server (NTRS)
Brooks, D G; Garlock, E A
1933-01-01
From tests made in the altitude chamber of the Bureau of Standards, it was found that the effect of humidity on engine power is the same at altitudes up to 25,000 feet as at sea level. Earlier tests on automotive engines, made under sea-level conditions, showed that water vapor acts as an inert diluent, reducing engine power in proportion to the amount of vapor present. By combining the effects of atmospheric pressure, temperature, and humidity, it is shown that the indicated power obtainable from an engine is proportional to its mass rate of consumption of oxygen. This has led the National Advisory Committee for Aeronautics to adopt a standard basis for the correction of engine performance, in which the effect of humidity is included.
Scientific and Engineering Research Facilities at Colleges and Universities, 1998. Topical Report.
ERIC Educational Resources Information Center
National Science Foundation, Arlington, VA. Div. of Science Resources Studies.
On a biennial basis since 1986, the National Science Foundation (NSF) has collected data on issues related to Science and Engineering (S&E) research facilities at U.S. colleges, universities, and biomedical institutions. This report presents the major findings from the 1998 survey and provides a summary of the changes that took place between…
41 CFR 101-26.602-1 - Procurement of lubricating oils, greases, and gear lubricants.
Code of Federal Regulations, 2013 CFR
2013-07-01
... (nonaircraft) equipment and of aircraft engine oils on an annual program basis. Estimates of requirements for... program Due on or before Lubricating oils (nonaircraft) 4.1 November 15. Aircraft engine oils 4.2 June 15... lubricating oils, greases, and gear lubricants. 101-26.602-1 Section 101-26.602-1 Public Contracts and...
41 CFR 101-26.602-1 - Procurement of lubricating oils, greases, and gear lubricants.
Code of Federal Regulations, 2014 CFR
2014-07-01
... (nonaircraft) equipment and of aircraft engine oils on an annual program basis. Estimates of requirements for... program Due on or before Lubricating oils (nonaircraft) 4.1 November 15. Aircraft engine oils 4.2 June 15... lubricating oils, greases, and gear lubricants. 101-26.602-1 Section 101-26.602-1 Public Contracts and...
41 CFR 101-26.602-1 - Procurement of lubricating oils, greases, and gear lubricants.
Code of Federal Regulations, 2011 CFR
2011-07-01
... (nonaircraft) equipment and of aircraft engine oils on an annual program basis. Estimates of requirements for... program Due on or before Lubricating oils (nonaircraft) 4.1 November 15. Aircraft engine oils 4.2 June 15... lubricating oils, greases, and gear lubricants. 101-26.602-1 Section 101-26.602-1 Public Contracts and...
41 CFR 101-26.602-1 - Procurement of lubricating oils, greases, and gear lubricants.
Code of Federal Regulations, 2010 CFR
2010-07-01
... (nonaircraft) equipment and of aircraft engine oils on an annual program basis. Estimates of requirements for... program Due on or before Lubricating oils (nonaircraft) 4.1 November 15. Aircraft engine oils 4.2 June 15... lubricating oils, greases, and gear lubricants. 101-26.602-1 Section 101-26.602-1 Public Contracts and...
41 CFR 101-26.602-1 - Procurement of lubricating oils, greases, and gear lubricants.
Code of Federal Regulations, 2012 CFR
2012-07-01
... (nonaircraft) equipment and of aircraft engine oils on an annual program basis. Estimates of requirements for... program Due on or before Lubricating oils (nonaircraft) 4.1 November 15. Aircraft engine oils 4.2 June 15... lubricating oils, greases, and gear lubricants. 101-26.602-1 Section 101-26.602-1 Public Contracts and...
40 CFR 86.1905 - How does this program work?
Code of Federal Regulations, 2011 CFR
2011-07-01
... least in part on the Phase 1 or Phase 2 testing outcomes described in § 86.1915. (2) The engine family... this section. We may select an engine family from the current model year or any previous model year... months longer to complete Phase 2 testing if there is a reasonable basis for needing more time. In very...
ERIC Educational Resources Information Center
Tchibozo, Guy
2005-01-01
In France, secondary teachers are public sector employees. Becoming a STEM (Science, Technology, Engineering, and Math) teacher in secondary education is subject to passing public competitive entry examinations. Preparation for these examinations is provided in College Departments, which are essentially assessed on the basis of their success…
ERIC Educational Resources Information Center
Weiss, J.; Egea-Cortines, M.
2008-01-01
We have been teaching applied molecular genetics to engineers and adapted the teaching methodology to the European Credit Transfer System. We teach core principles of genetics that are universal and form the conceptual basis of most molecular technologies. The course then teaches widely used techniques and finally shows how different techniques…
ERIC Educational Resources Information Center
Jianwei, Yang; Aihua, Zhu; Yuanyuan, Zhang; Chunqing, Zhao
2016-01-01
According to the idea of CDIO engineering education, this paper, combing with professional certification, makes training plan of Urban Rail Transit Vehicles Engineering direction in our school on the basis of research on universities at home and abroad. It strengthens the teaching of basic subjects and increases the weeks of practice link in the…
ERIC Educational Resources Information Center
Smith, Emma; White, Patrick
2017-01-01
Concerns about a shortage of highly skilled workers in the science, technology, engineering and mathematics (STEM) sector have been expressed frequently since the late 1940s. Although these claims have been challenged as being insufficiently grounded in evidence, they have formed the basis of policies directing considerable resources to STEM…
A candidate architecture for monitoring and control in chemical transfer propulsion systems
NASA Technical Reports Server (NTRS)
Binder, Michael P.; Millis, Marc G.
1990-01-01
To support the exploration of space, a reusable space-based rocket engine must be developed. This engine must sustain superior operability and man-rated levels of reliability over several missions with limited maintenance or inspection between flights. To meet these requirements, an expander cycle engine incorporating a highly capable control and health monitoring system is planned. Alternatives for the functional organization and the implementation architecture of the engine's monitoring and control system are discussed. On the basis of this discussion, a decentralized architecture is favored. The trade-offs between several implementation options are outlined and future work is proposed.
NASA Astrophysics Data System (ADS)
Romero, Jesus Franklin A.; Leite, Patrícia; Mantovani, Gerson L.; Lanfredi, Alexandre J. C.; Martins-Filho, Luiz S.
2011-06-01
This paper describes the experience of an introductory discipline to the engineering curricula at the Brazilian Federal University of ABC (UFABC). The university offers a common basic curriculum that must be accomplished by every student and can be followed by professionalising courses. The discipline 'Introduction to Engineering' presents the basis of the engineering career, methods and thinking together with professional commitments and regulations. The objective is to help students to consciously choose their careers, minimising the precocity problem in deciding a professional future. The discipline methodology includes activities proposed by the TryEngineering website and from Brazilian engineering councils. Lectures with invited professors introduce UFABC engineering specialities: Aerospace, Bioengineering, Energy, Environmental & Urban, Information, Instrumentation & Automation & Robotics, Management, Materials. This paper reports the proposed activities, results obtained by the students, a methodology critical analysis and the impacts on the following steps of students embracing an engineering career.
2011-03-01
Center 1261 Duck Rd. Kitty Hawk, NC 27949 Lisa Stillwell, Margaret Blanchard-Montgomery, Brian Blanton Renaissance Computing Institute 100 Europa...Insurance Studies in the study area, and serve as the basis for new coastal hazard analysis and ultimately updated Flood Insurance Rate Maps (FIRMs). Study... hazard zones in coastal areas of the United States. Under Task Order HSFE03-06-X-0023, the U.S. Army Corps of Engineers (USACE) and project partners are
NASA Technical Reports Server (NTRS)
1979-01-01
Results of a study leading to the preliminary design of a five passenger hybrid vehicle utilizing two energy sources (electricity and gasoline/diesel fuel) to minimize petroleum usage on a fleet basis are presented. The study methodology is described. Vehicle characterizations, the mission description, characterization, and impact on potential sales, and the rationale for the selection of the reference internal combustion engine vehicle are presented. Conclusions and recommendations of the mission analysis and performance specification report are included.
An Air Force Guide to the System Specification.
1981-01-01
basis for sound management plans and decisions to initiate system full-scale development. Related topics include: current problems and questions...such current documents as AFR 800-2 and AFR 57-1. Key elements of coverage include the following: a. Levels of system engineering studies are...equipment and computer program elements of a system are acquired most directly acainst lower-level (configuration item) specifications. b. Current
Code of Federal Regulations, 2011 CFR
2011-07-01
... or combustion engines. One commenter suggested using exhaust level as the determinant. Although there... for the definition of “wheelchair” in section 508(c)(2) of the ADA. One commenter indicated a...-operated wheelchairs of 6 miles per hour. In a study of trail and other non-motorized transportation users...
Code of Federal Regulations, 2013 CFR
2013-07-01
... or combustion engines. One commenter suggested using exhaust level as the determinant. Although there... for the definition of “wheelchair” in section 508(c)(2) of the ADA. One commenter indicated a...-operated wheelchairs of 6 miles per hour. In a study of trail and other non-motorized transportation users...
Code of Federal Regulations, 2014 CFR
2014-07-01
... or combustion engines. One commenter suggested using exhaust level as the determinant. Although there... for the definition of “wheelchair” in section 508(c)(2) of the ADA. One commenter indicated a...-operated wheelchairs of 6 miles per hour. In a study of trail and other non-motorized transportation users...
Code of Federal Regulations, 2012 CFR
2012-07-01
... or combustion engines. One commenter suggested using exhaust level as the determinant. Although there... for the definition of “wheelchair” in section 508(c)(2) of the ADA. One commenter indicated a...-operated wheelchairs of 6 miles per hour. In a study of trail and other non-motorized transportation users...
The Learning Basis of Automated Factories: The Case of FIAT. Training Discussion Paper No. 86.
ERIC Educational Resources Information Center
Araujo e Oliveira, Joao Batista
As part of a study on the impact of automation on training, extensive interviews were conducted at two of Fiat's plants, Termoli and Casino, Italy. Termoli, a plant built in the mid-1980s with automation in mind, production of engines and gear boxes was very much integrated by automation devices. Casino produced some individual components but was…
Borescope Inspection Management for Engine
NASA Astrophysics Data System (ADS)
Zhongda, Yuan
2018-03-01
In this paper, we try to explain the problems need to be improved from the two perspectives of maintenance program management and maintenance human risk control. On the basis of optimization analysis of borescope inspection maintenance scheme, the defect characteristics and expansion rules of engine heat terminal components are summarized, and some optimization measures are introduced. This paper analyses human risk problem of engine hole from the aspects of qualification management, training requirements and perfection of system, and puts forward some suggestions on management.
NASA Technical Reports Server (NTRS)
Sarracino, Marcello
1941-01-01
The present article deals with what is considered to be a simpler and more accurate method of determining, from the results of bench tests under approved rating conditions, the power at altitude of a supercharged aircraft engine, without application of correction formulas. The method of calculating the characteristics at altitude, of supercharged engines, based on the consumption of air, is a more satisfactory and accurate procedure, especially at low boost pressures.
Generali, Melanie; Kehl, Debora; Capulli, Andrew K; Parker, Kevin K; Hoerstrup, Simon P; Weber, Benedikt
2017-10-01
Biodegradable scaffold matrixes form the basis of any in vitro tissue engineering approach by acting as a temporary matrix for cell proliferation and extracellular matrix deposition until the scaffold is replaced by neo-tissue. In this context several synthetic polymers have been investigated, however a concise systematic comparative analyses is missing. Therefore, the present study systematically compares three frequently used polymers for the in vitro engineering of extracellular matrix based on poly-glycolic acid (PGA) under static as well as dynamic conditions. Ultra-structural analysis was used to examine the polymers structure. For tissue engineering (TE) three human fibroblast cell lines were seeded on either PGA-poly-4-hydroxybutyrate (P4HB), PGA-poly-lactic acid (PLA) or PGA-poly-caprolactone (PCL) patches. These patches were analyzed after 21days of culture qualitative by histology and quantitative by determining the amount of DNA, glycosaminoglycan and hydroxyproline. We found that PGA-P4HB and PGA-PLA scaffolds enhance tissue formation significantly higher than PGA-PCL scaffolds (p<0.05). Polymer remnants were visualized by polarization microscopy. In addition, biomechanical properties of the tissue engineered patches were determined in comparison to native tissue. This study may allow future studies to specifically select certain polymer starter matrices aiming at specific tissue properties of the bioengineered constructs in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Oldrieve, R. E.
1971-01-01
Fourteen materials were evaluated in engine screening tests on full-size thermal reactors for automobile engine pollution control systems. Cyclic test-stand engine operation provided 2 hours at 1040 C and a 20-minute air-cool to 70 C each test cycle. Each reactor material was exposed to 83 cycles in 200 hours of engine testing. On the basis of resistance to oxidation and distortion, the best materials included two ferritic iron alloys (Ge 1541 and Armco 18S/R), several commercial oxidation-resistant coatings on AlSl 651 (19-9 DL), and possibly uncoated AISI 310. The best commercial coatings were Cr-Al, Ni-Cr, and a glass ceramic.
Engine Data Interpretation System (EDIS)
NASA Technical Reports Server (NTRS)
Cost, Thomas L.; Hofmann, Martin O.
1990-01-01
A prototype of an expert system was developed which applies qualitative or model-based reasoning to the task of post-test analysis and diagnosis of data resulting from a rocket engine firing. A combined component-based and process theory approach is adopted as the basis for system modeling. Such an approach provides a framework for explaining both normal and deviant system behavior in terms of individual component functionality. The diagnosis function is applied to digitized sensor time-histories generated during engine firings. The generic system is applicable to any liquid rocket engine but was adapted specifically in this work to the Space Shuttle Main Engine (SSME). The system is applied to idealized data resulting from turbomachinery malfunction in the SSME.
Public Involvement in the Corps of Engineers Planning Process
1975-10-01
words, public involvement should be planned for on a stagc-by- » ugc basis rather than looking at it in relation to the study as a whole. Moreover...conferences. * news releases. * mailings to people in the study area on the district’s mailing list, display advertisements in area newspapers...tion do not, as a rule, attract the kind of atten- tion that is needed. Paid advertisements in news sections of newspapers attract much more atten
NASA Technical Reports Server (NTRS)
Eldridge, W. M.; Ferrell, J. A.; Mckee, J. W.; Wayne, J. E., Jr.; Zabinsky, J. M.
1973-01-01
Conceptual designs of V/STOL lift fan commercial short haul transport aircraft for the 1980-85 time period were studied to determine their technical and economic feasibility. The engine concepts included both integral and remote fans. The scope of the study included definition of the hover control concept for each propulsion system, aircraft design, aircraft mass properties, cruise performance, noise and ride qualities evaluation. Economic evaluating was also studied on a basis of direct operating costs and route structure.
Study of inducer load and stress, volume 2
NASA Technical Reports Server (NTRS)
1972-01-01
A program of analysis, design, fabrication and testing has been conducted to develop computer programs for predicting rocket engine turbopump inducer hydrodynamic loading, stress magnitude and distribution, and vibration characteristics. Methods of predicting blade loading, stress, and vibration characteristics were selected from a literature search and used as a basis for the computer programs. An inducer, representative of typical rocket engine inducers, was designed, fabricated, and tested with special instrumentation selected to provide measurements of blade surface pressures and stresses. Data from the tests were compared with predicted values and the computer programs were revised as required to improve correlation. For Volume 1 see N71-20403. For Volume 2 see N71-20404.
Organs-on-a-chip: a focus on compartmentalized microdevices.
Moraes, Christopher; Mehta, Geeta; Lesher-Perez, Sasha Cai; Takayama, Shuichi
2012-06-01
Advances in microengineering technologies have enabled a variety of insights into biomedical sciences that would not have been possible with conventional techniques. Engineering microenvironments that simulate in vivo organ systems may provide critical insight into the cellular basis for pathophysiologies, development, and homeostasis in various organs, while curtailing the high experimental costs and complexities associated with in vivo studies. In this article, we aim to survey recent attempts to extend tissue-engineered platforms toward simulating organ structure and function, and discuss the various approaches and technologies utilized in these systems. We specifically focus on microtechnologies that exploit phenomena associated with compartmentalization to create model culture systems that better represent the in vivo organ microenvironment.
NASA Astrophysics Data System (ADS)
Zamel, Nada; Li, Xianguo
The objective of this study is to put forward a full analysis of the impact of the difference between the Canadian and American energy realities on the life cycle of fuel cell vehicles and internal combustion engine vehicles. Electricity is a major type of energy used in the transportation sector. Electricity is needed in the production of feedstock of fuel, the production of the fuel, the production of the vehicle material and the assembly of the vehicles. Therefore, it is necessary to investigate the impact of the electricity mix difference between Canada and the United States. In the analysis, the life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extract hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that fuel cell vehicle fuelled by hydrogen has lower energy consumption and greenhouse gas emissions than internal combustion engine vehicle fuelled by conventional gasoline except for hydrogen production using coal as the primary energy source in Canada and the United States. Using the Canadian electricity mix will result in lower carbon dioxide emissions and energy consumption than using the American electricity mix. For the present vehicles, using the Canadian electricity mix will save up to 215.18 GJ of energy and 20.87 t of CO 2 on a per capita basis and 26.53 GJ of energy and 6.8 t of CO 2 on a per vehicle basis. Similarly, for the future vehicles, using the Canadian electricity mix will lower the total carbon dioxide emissions by 21.15 t and the energy consumed is reduced by 218.49 GJ on a per capita basis and 26.53 GJ of energy and 7.22 t of CO 2 on a per vehicle basis. The well-to-tank efficiencies are higher with the Canadian electricity mix.
Yan, Liwei; Yao, Zhi; Lin, Tao; Zhu, Qingtang; Qi, Jian; Gu, Liqiang; Fang, Jintao; Zhou, Xiang
2017-01-01
Peripheral nerve injury therapy in the clinic remains less than satisfactory. The gold standard of treatment for long peripheral nerve defects is autologous nerve grafts; however, numerous clinical complications are associated with this treatment. As tissue engineering has developed, tissue-engineered nerve grafts (TENGs) have shown potential applications as alternatives to autologous nerve grafts. To verify the important role of the biomimetic pathway of fascicle design in TENGs, we designed an animal model to study the role of the precise matching of fascicles in the effectiveness of nerve function recovery. 24 Sprague-Dawley rats were divided randomly into three groups (eight/group) that corresponded to 100% fascicle matching (100%FM), 50%FM and 0%FM. We selected Sprague–Dawley rat long-gap (15 mm) sciatic nerve defects. In the 6 weeks after surgery, we found that the 100%FM group showed the most effective functional recovery among the three groups. The 100%FM group showed better functional recovery on the basis of the sciatic functional index than the 50%FM and 0%FM groups. According to histological evaluation, the 100%FM group showed more regenerating nerve fibres. Moreover, in terms of the prevention of muscle atrophy, the 100%FM group showed excellent physiological outcomes. The 100%FM as tissue-engineered scaffolds can enhance nerve regeneration and effective functional recovery after the repair of large nerve defects. The results of this study provide a theoretical basis for future TENG designs including biomimetic fascicle pathways for repairing long nerve defects. PMID:28914740
NASA Astrophysics Data System (ADS)
Merkisz, Jerzy; Fuc, Pawel; Lijewski, Piotr; Ziolkowski, Andrzej; Galant, Marta; Siedlecki, Maciej
2016-08-01
We have analyzed the increase of the overall efficiency of a spark ignition engine through energy recovery following the application of an automotive thermoelectric generator (ATEG) of our own design. The design of the generator was developed following emission investigations during vehicle driving under city traffic conditions. The measurement points were defined by actual operation conditions (engine speed and load), subsequently reproduced on an engine dynamometer. Both the vehicle used in the on-road tests and the engine dynamometer were fit with the same, downsized spark ignition engine (with high effective power-to-displacement ratio). The thermodynamic parameters of the exhaust gases (temperature and exhaust gas mass flow) were measured on the engine testbed, along with the fuel consumption and electric current generated by the thermoelectric modules. On this basis, the power of the ATEG and its impact on overall engine efficiency were determined.
NASA Astrophysics Data System (ADS)
Wang, Juan; Sun, Binbin; Bhutto, Muhammad Aqeel; Zhu, Tonghe; Yu, Kui; Bao, Jiayu; Morsi, Yosry; El-Hamshary, Hany; El-Newehy, Mohamed; Mo, Xiumei
2017-03-01
Electrospun nanofibers have gained widespreading interest for tissue engineering application. In the present study, ApF/P(LLA-CL) nanofibrous scaffolds were fabricated via electrospinning. The feasibility of the material as tissue engineering nerve scaffold was investigated in vitro. The average diameter increased with decreasing the blend ratio of ApF to P(LLA-CL). Characterization of 13C NMR and FTIR clarified that there is no obvious chemical bond reaction between ApF and P(LLA-CL). The tensile strength and elongation at break increased with the content increase of P(LLA-CL). The surface hydrophilic property of nanofibrous scaffolds enhanced with the increased content of ApF. Cell viability studies with Schwann cells demonstrated that ApF/P(LLA-CL) blended nanofibrous scaffolds significantly promoted cell growth as compare to P(LLA-CL), especially when the weight ratio of ApF to P(LLA-CL) was 25:75. The present work provides a basis for further studies of this novel nanofibrous material (ApF/P(LLA-CL)) in peripheral nerve tissue repair or regeneration.
Compression-ignition Engine Performance at Altitudes and at Various Air Pressures and Temperatures
NASA Technical Reports Server (NTRS)
Moore, Charles S; Collins, John H
1937-01-01
Engine test results are presented for simulated altitude conditions. A displaced-piston combustion chamber on a 5- by 7-inch single cylinder compression-ignition engine operating at 2,000 r.p.m. was used. Inlet air temperature equivalent to standard altitudes up to 14,000 feet were obtained. Comparison between performance at altitude of the unsupercharged compression-ignition engine compared favorably with the carburetor engine. Analysis of the results for which the inlet air temperature, inlet air pressure, and inlet and exhaust pressure were varied indicates that engine performance cannot be reliably corrected on the basis of inlet air density or weight of air charge. Engine power increases with inlet air pressure and decreases with inlet air temperatures very nearly as straight line relations over a wide range of air-fuel ratios. Correction factors are given.
High-Altitude Flight Cooling Investigation of a Radial Air-Cooled Engine
NASA Technical Reports Server (NTRS)
Manganiello, Eugene J; Valerino, Michael F; Bell, E Barton
1947-01-01
An investigation of the cooling of an 18-cylinder, twin-row, radial, air-cooled engine in a high-performance pursuit airplane has been conducted for variable engine and flight conditions at altitudes ranging from 5000 to 35,000 feet in order to provide a basis for predicting high-altitude cooling performance from sea-level or low altitude experimental results. The engine cooling data obtained were analyzed by the usual NACA cooling-correlation method wherein cylinder-head and cylinder-barrel temperatures are related to the pertinent engine and cooling-air variables. A theoretical analysis was made of the effect on engine cooling of the change of density of the cooling air across the engine (the compressibility effect), which becomes of increasing importance as altitude is increased. Good agreement was obtained between the results of the theoretical analysis and the experimental data.
Influence of Alternative Engine Concepts on LCTR2 Sizing and Mission Profile
NASA Technical Reports Server (NTRS)
Acree, C. W., Jr.; Snyder, Christopher A.
2012-01-01
The Large Civil Tiltrotor (LCTR) was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing. This paper examines the impact of advanced propulsion system concepts on LCTR2 sizing. Two concepts were studied: an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE), and a variable-speed power turbine engine (VSPT). The ACE is the lighter engine, but requires a multi-speed (shifting) gearbox, whereas the VSPT uses a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle weight empty for variations in mission altitude and range; the effect of different One Engine Inoperative (OEI) criteria are also examined. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. The two propulsion concepts had nearly identical vehicle weights and mission fuel consumption, and their relative advantages varied little with cruise altitude, mission range, or OEI criteria; high cruise altitude and low cruise tip speed were beneficial for both concepts.
NASA Astrophysics Data System (ADS)
Shu, Gequn; Pan, Jiaying; Wei, Haiqiao; Shi, Ning
2013-03-01
Knock in spark-ignition(SI) engines severely limits engine performance and thermal efficiency. The researches on knock of downsized SI engine have mainly focused on structural design, performance optimization and advanced combustion modes, however there is little for simulation study on the effect of cooled exhaust gas recirculation(EGR) combined with downsizing technologies on SI engine performance. On the basis of mean pressure and oscillating pressure during combustion process, the effect of different levels of cooled EGR ratio, supercharging and compression ratio on engine dynamic and knock characteristic is researched with three-dimensional KIVA-3V program coupled with pressure wave equation. The cylinder pressure, combustion temperature, ignition delay timing, combustion duration, maximum mean pressure, and maximum oscillating pressure at different initial conditions are discussed and analyzed to investigate potential approaches to inhibiting engine knock while improving power output. The calculation results of the effect of just cooled EGR on knock characteristic show that appropriate levels of cooled EGR ratio can effectively suppress cylinder high-frequency pressure oscillations without obvious decrease in mean pressure. Analysis of the synergistic effect of cooled EGR, supercharging and compression ratio on knock characteristic indicates that under the condition of high supercharging and compression ratio, several times more cooled EGR ratio than that under the original condition is necessarily utilized to suppress knock occurrence effectively. The proposed method of synergistic effect of cooled EGR and downsizing technologies on knock characteristic, analyzed from the aspects of mean pressure and oscillating pressure, is an effective way to study downsized SI engine knock and provides knock inhibition approaches in practical engineering.
Orbit transfer rocket engine technology program
NASA Technical Reports Server (NTRS)
Gustafson, N. B.; Harmon, T. J.
1993-01-01
An advanced near term (1990's) space-based Orbit Transfer Vehicle Engine (OTVE) system was designed, and the technologies applicable to its construction, maintenance, and operations were developed under Tasks A through F of the Orbit Transfer Rocket Engine Technology Program. Task A was a reporting task. In Task B, promising OTV turbomachinery technologies were explored: two stage partial admission turbines, high velocity ratio diffusing crossovers, soft wear ring seals, advanced bearing concepts, and a rotordynamic analysis. In Task C, a ribbed combustor design was developed. Possible rib and channel geometries were chosen analytically. Rib candidates were hot air tested and laser velocimeter boundary layer analyses were conducted. A channel geometry was also chosen on the basis of laser velocimeter data. To verify the predicted heat enhancement effects, a ribbed calorimeter spool was hot fire tested. Under Task D, the optimum expander cycle engine thrust, performance and envelope were established for a set of OTV missions. Optimal nozzle contours and quick disconnects for modularity were developed. Failure Modes and Effects Analyses, maintenance and reliability studies and component study results were incorporated into the engine system. Parametric trades on engine thrust, mixture ratio, and area ratio were also generated. A control system and the health monitoring and maintenance operations necessary for a space-based engine were outlined in Task E. In addition, combustor wall thickness measuring devices and a fiberoptic shaft monitor were developed. These monitoring devices were incorporated into preflight engine readiness checkout procedures. In Task F, the Integrated Component Evaluator (I.C.E.) was used to demonstrate performance and operational characteristics of an advanced expander cycle engine system and its component technologies. Sub-system checkouts and a system blowdown were performed. Short transitions were then made into main combustor ignition and main stage operation.
Genetic engineering of woody plants: current and future targets in a stressful environment.
Osakabe, Yuriko; Kajita, Shinya; Osakabe, Keishi
2011-06-01
Abiotic stress is a major factor in limiting plant growth and productivity. Environmental degradation, such as drought and salinity stresses, will become more severe and widespread in the world. To overcome severe environmental stress, plant biotechnologies, such as genetic engineering in woody plants, need to be implemented. The adaptation of plants to environmental stress is controlled by cascades of molecular networks including cross-talk with other stress signaling mechanisms. The present review focuses on recent studies concerning genetic engineering in woody plants for the improvement of the abiotic stress responses. Furthermore, it highlights the recent advances in the understanding of molecular responses to stress. The review also summarizes the basis of a molecular mechanism for cell wall biosynthesis and the plant hormone responses to regulate tree growth and biomass in woody plants. This would facilitate better understanding of the control programs of biomass production under stressful conditions. Copyright © Physiologia Plantarum 2011.
Improving of Hybrid Rocket Engine on the Basis of Optimizing Design Fuel Grain
NASA Astrophysics Data System (ADS)
Oriekov, K. M.; Ushkin, M. P.
2015-09-01
This article examines the processes intrachamber in hybrid rocket engine (HRE) and the comparative assessment of the use of solid rocket motors (SRM) and HRE for meteorological rockets with a mass of payload of the 364 kg. Results of the research showed the possibility of a significant increase in the ballistic effectiveness of meteorological rocket.
THE CURRENT EMPLOYMENT MARKET FOR ENGINEERS, SCIENTISTS, AND TECHNICIANS, DECEMBER 1966.
ERIC Educational Resources Information Center
AUSMUS, NORMA F.; AND OTHERS
FIELD REPORTS ON JUNE 1966 CONDITIONS IN 30 MAJOR LABOR AREAS FOR ENGINEERING, SCIENTIFIC, AND TECHNICAL OCCUPATIONS, PROVIDED BY AFFILIATES OF THE BUREAU OF EMPLOYMENT SECURITY, WERE THE BASIS FOR THIS SEMIANNUAL REPORT. THE NUMBER OF APPLICANTS HAD DECLINED 48 PERCENT TO A NEW 8-YEAR LOW, WHILE OPENINGS HAD RISEN TO 9,600, 58 PERCENT OVER THE…
[Comprehensive evaluation and selection of urban eco-engineering virescent trees in Shenyang City].
Lu, Min; Jiang, Fengqi; Li, Yingjie
2004-07-01
Urban virescence eco-engineering is the core of urban eco-environmental construction, which can promote urban sustainable development. In urban virescence eco-engineering, the comprehensive evaluation of ecological adapt-ability and ecological effect of urban plants is the scientific basis of rational application and selection of urban garden plants. The ecological effect and integrative functions of urban virescence eco-engineering depend upon the selection and layout of garden plants. Using the methods of garden expert consultation and evaluation, this paper established systematically integrative evaluation and application indices of virescence plants in Shenyang City, from the aspects of ecological adaptability, ecological effect, beautification effect, resistance to plant diseases and insect pests, anti-pollution and economic results. According to garden experts evaluation and location of Shenyang, 200 sorts of virescence trees were evaluated and classified on the basis of the comprehensive evaluation system of virescence trees, and using cold resistance, drought resistance, barren resistance, plant diseases and insect pests resistance, anti-pollution, ornamental quality and ecological effects as the indexes. The results showed that the number of first rank trees was 58, the second was 93, methods of third was 38, and the fourth was 11, ranked by integrative performance.
A molecular engineering toolbox for the structural biologist
Debelouchina, Galia T.; Muir, Tom W.
2018-01-01
Exciting new technological developments have pushed the boundaries of structural biology, and have enabled studies of biological macromolecules and assemblies that would have been unthinkable not long ago. Yet, the enhanced capabilities of structural biologists to pry into the complex molecular world have also placed new demands on the abilities of protein engineers to reproduce this complexity into the test tube. With this challenge in mind, we review the contents of the modern molecular engineering toolbox that allow the manipulation of proteins in a site-specific and chemically well-defined fashion. Thus, we cover concepts related to the modification of cysteines and other natural amino acids, native chemical ligation, intein and sortase-based approaches, amber suppression, as well as chemical and enzymatic bio-conjugation strategies. We also describe how these tools can be used to aid methodology development in X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy and in the studies of dynamic interactions. It is our hope that this monograph will inspire structural biologists and protein engineers alike to apply these tools to novel systems, and to enhance and broaden their scope to meet the outstanding challenges in understanding the molecular basis of cellular processes and disease. PMID:29233219
A molecular engineering toolbox for the structural biologist.
Debelouchina, Galia T; Muir, Tom W
2017-01-01
Exciting new technological developments have pushed the boundaries of structural biology, and have enabled studies of biological macromolecules and assemblies that would have been unthinkable not long ago. Yet, the enhanced capabilities of structural biologists to pry into the complex molecular world have also placed new demands on the abilities of protein engineers to reproduce this complexity into the test tube. With this challenge in mind, we review the contents of the modern molecular engineering toolbox that allow the manipulation of proteins in a site-specific and chemically well-defined fashion. Thus, we cover concepts related to the modification of cysteines and other natural amino acids, native chemical ligation, intein and sortase-based approaches, amber suppression, as well as chemical and enzymatic bio-conjugation strategies. We also describe how these tools can be used to aid methodology development in X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy and in the studies of dynamic interactions. It is our hope that this monograph will inspire structural biologists and protein engineers alike to apply these tools to novel systems, and to enhance and broaden their scope to meet the outstanding challenges in understanding the molecular basis of cellular processes and disease.
Conceptual design study of an improved automotive gas turbine powertrain
NASA Technical Reports Server (NTRS)
Wagner, C. E. (Editor); Pampreen, R. C. (Editor)
1979-01-01
Automotive gas turbine concepts with significant technological advantages over the spark ignition (SI) engine were assessed. Possible design concepts were rated with respect to fuel economy and near-term application. A program plan which outlines the development of the improved gas turbine (IGT) concept that best met the goals and objectives of the study identifies the research and development work needed to meet the goal of entering a production engineering phase by 1983. The fuel economy goal is to show at least a 20% improvement over a conventional 1976 SI engine/vehicle system. On the basis of achieving the fuel economy goal, of overall suitability to mechanical design, and of automotive mass production cost, the powertrain selected was a single-shaft engine with a radial turbine and a continuously variable transmission (CVT). Design turbine inlet temperature was 1150 C. Reflecting near-term technology, the turbine rotor would be made of an advanced superalloy, and the transmission would be a hydromechanical CVT. With successful progress in long-lead R&D in ceramic technology and the belt-drive CVT, the turbine inlet temperature would be 1350 C to achieve near-maximum fuel economy.
Data-Mining Toolset Developed for Determining Turbine Engine Part Life Consumption
NASA Technical Reports Server (NTRS)
Litt, Jonathan S.
2003-01-01
The current practice in aerospace turbine engine maintenance is to remove components defined as life-limited parts after a fixed time, on the basis of a predetermined number of flight cycles. Under this schedule-based maintenance practice, the worst-case usage scenario is used to determine the usable life of the component. As shown, this practice often requires removing a part before its useful life is fully consumed, thus leading to higher maintenance cost. To address this issue, the NASA Glenn Research Center, in a collaborative effort with Pratt & Whitney, has developed a generic modular toolset that uses data-mining technology to parameterize life usage models for maintenance purposes. The toolset enables a "condition-based" maintenance approach, where parts are removed on the basis of the cumulative history of the severity of operation they have experienced. The toolset uses data-mining technology to tune life-consumption models on the basis of operating and maintenance histories. The flight operating conditions, represented by measured variables within the engine, are correlated with repair records for the engines, generating a relationship between the operating condition of the part and its service life. As shown, with the condition-based maintenance approach, the lifelimited part is in service until its usable life is fully consumed. This approach will lower maintenance costs while maintaining the safety of the propulsion system. The toolset is a modular program that is easily customizable by users. First, appropriate parametric damage accumulation models, which will be functions of engine variables, must be defined. The tool then optimizes the models to match the historical data by computing an effective-cycle metric that reduces the unexplained variability in component life due to each damage mode by accounting for the variability in operational severity. The damage increment due to operating conditions experienced during each flight is used to compute the effective cycles and ultimately the replacement time. Utilities to handle data problems, such as gaps in the flight data records, are included in the toolset. The tool was demonstrated using the first stage, high-pressure turbine blade of the PW4077 engine (Pratt & Whitney, East Hartford, CT). The damage modes considered were thermomechanical fatigue and oxidation/erosion. Each PW4077 engine contains 82 first-stage, high-pressure turbine blades, and data from a fleet of engines were used to tune the life-consumption models. The models took into account not only measured variables within the engine, but also unmeasured variables such as engine health parameters that are affected by degradation of the engine due to aging. The tool proved effective at predicting the average number of blades scrapped over time due to each damage mode, per engine, given the operating history of the engine. The customizable tools are available to interested parties within the aerospace community.
Conventional engine technology. Volume 3: Comparisons and future potential
NASA Technical Reports Server (NTRS)
Dowdy, M. W.
1981-01-01
The status of five conventional automobile engine technologies was assessed and the future potential for increasing fuel economy and reducing exhaust emission was discussed, using the 1980 EPA California emisions standards as a comparative basis. By 1986, the fuel economy of a uniform charge Otto engine with a three-way catalyst is expected to increase 10%, while vehicles with lean burn (fast burn) engines should show a 20% fuel economy increase. Although vehicles with stratified-charge engines and rotary engines are expected to improve, their fuel economy will remain inferior to the other engine types. When adequate NO emissions control methods are implemented to meet the EPA requirements, vehicles with prechamber diesel engines are expected to yield a fuel economy advantage of about 15%. While successful introduction of direct injection diesel engine technology will provide a fuel savings of 30 to 35%, the planned regulation of exhaust particulates could seriously hinder this technology, because it is expected that only the smallest diesel engine vehicles could meet the proposed particulate requirements.
Lynd; Wyman; Gerngross
1999-10-01
The application of biotechnology to the production of commodity products (fuels, chemicals, and materials) offering benefits in terms of sustainable resource supply and environmental quality is an emergent area of intellectual endeavor and industrial practice with great promise. Such "biocommodity engineering" is distinct from biotechnology motivated by health care at multiple levels, including economic driving forces, the importance of feedstocks and cost-motivated process engineering, and the scale of application. Plant biomass represents both the dominant foreseeable source of feedstocks for biotechnological processes as well as the only foreseeable sustainable source of organic fuels, chemicals, and materials. A variety of forms of biomass, notably many cellulosic feedstocks, are potentially available at a large scale and are cost-competitive with low-cost petroleum whether considered on a mass or energy basis, and in terms of price defined on a purchase or net basis for both current and projected mature technology, and on a transfer basis for mature technology. Thus the central, and we believe surmountable, impediment to more widespread application of biocommodity engineering is the general absence of low-cost processing technology. Technological and research challenges associated with converting plant biomass into commodity products are considered relative to overcoming the recalcitrance of cellulosic biomass (converting cellulosic biomass into reactive intermediates) and product diversification (converting reactive intermediates into useful products). Advances are needed in pretreatment technology to make cellulosic materials accessible to enzymatic hydrolysis, with increased attention to the fundamental chemistry operative in pretreatment processes likely to accelerate progress. Important biotechnological challenges related to the utilization of cellulosic biomass include developing cellulase enzymes and microorganisms to produce them, fermentation of xylose and other nonglucose sugars, and "consolidated bioprocessing" in which cellulase production, cellulose hydrolysis, and fermentation of soluble carbohydrates to desired products occur in a single process step. With respect to product diversification, a distinction is made between replacement of a fossil resource-derived chemical with a biomass-derived chemical of identical composition and substitution of a biomass-derived chemical with equivalent functional characteristics but distinct composition. The substitution strategy involves larger transition issues but is seen as more promising in the long term. Metabolic engineering pursuant to the production of biocommodity products requires host organisms with properties such as the ability to use low-cost substrates, high product yield, competitive fitness, and robustness in industrial environments. In many cases, it is likely to be more successful to engineer a desired pathway into an organism having useful industrial properties rather than trying to engineer such often multi-gene properties into host organisms that do not have them naturally. Identification of host organisms with useful industrial properties and development of genetic systems for these organisms is a research challenge distinctive to biocommodity engineering. Chemical catalysis and separations technologies have important roles to play in downstream processing of biocommodity products and involve a distinctive set of challenges relative to petrochemical processing. At its current nascent state of development, the definition and advancement of the biocommodity field can benefit from integration at multiple levels. These include technical issues associated with integrating unit operations with each other, integrating production of individual products into a multi-product biorefinery, and integrating biorefineries into the broader resource, economic, and environmental systems in which they function. We anticipate that coproduction of multiple products, for example, production of fuels, chemicals, power, and/or feed, is likely to be essential for economic viability. Lifecycle analysis is necessary to verify the sustainability and environmental quality benefits of a particular biocommodity product or process. We see biocommodity engineering as a legitimate focus for graduate study, which is responsive to an established personnel demand in an industry that is expected to grow in the future. Graduate study in biocommodity engineering is supported by a distinctive blend of intellectual elements, including biotechnology, process engineering, and resource and environmental systems.
Statistics of indicated pressure in combustion engine.
NASA Astrophysics Data System (ADS)
Sitnik, L. J.; Andrych-Zalewska, M.
2016-09-01
The paper presents the classic form of pressure waveforms in burn chamber of diesel engine but based on strict analytical basis for amending the displacement volume. The pressure measurement results are obtained in the engine running on an engine dynamometer stand. The study was conducted by a 13-phase ESC test (European Stationary Cycle). In each test phase are archived 90 waveforms of pressure. As a result of extensive statistical analysis was found that while the engine is idling distribution of 90 value of pressure at any value of the angle of rotation of the crankshaft can be described uniform distribution. In the each point of characteristic of the engine corresponding to the individual phases of the ESC test, 90 of the pressure for any value of the angle of rotation of the crankshaft can be described as normal distribution. These relationships are verified using tests: Shapiro-Wilk, Jarque-Bera, Lilliefors, Anderson-Darling. In the following part, with each value of the crank angle, are obtain values of descriptive statistics for the pressure data. In its essence, are obtained a new way to approach the issue of pressure waveform analysis in the burn chamber of engine. The new method can be used to further analysis, especially the combustion process in the engine. It was found, e.g. a very large variances of pressure near the transition from compression to expansion stroke. This lack of stationarity of the process can be important both because of the emissions of exhaust gases and fuel consumption of the engine.
Checkout systems: Summary report for the universal control and display console
NASA Technical Reports Server (NTRS)
1971-01-01
The development of a unified test equipment checkout concept based on a universal control and display console system is discussed. The checkout requirements are analyzed for the shuttle and space station. Capability, size, utilization requirements and specifications of the ground checkout system are made on the basis of engineering trade-off studies. Recommendations related to the attainment of overall unified test equipment conceptual goals and objectives are submitted.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Holmes, W.A.
Energy engineering and management combines engineering problem-solving and financial management techniques to reduce utility costs. At present, substantial amounts of time and money are being spent in order to attempt to quantify energy consumption and costs and define opportunities for savings. Unfortunately, accurate verification of results is often overlooked. Advances in technology during the last few years have made the installation of a permanent, PC-based monitoring system possible for any facility, often for no more than the cost of a detailed study. By investing initially in a monitoring system rather than audits or studies, the actual consumption and cost datamore » will be available on a continuing basis and can be used to produce immediate operational savings, more accurately analyze opportunities requiring capital investments, and to verify actual savings resulting from changes. A permanent monitoring system, installed as the first step in a utility cost reduction effort, to identify where and how energy is used in a facility on a dynamic and real-time basis, can provide the most valuable and cost-effective tool available to an energy manager. The resulting data allows energy consumption patterns and utility costs to be understood and managed in the same manner as all other costs within a facility.« less
Applied Mathematics for agronomical engineers in Spain at UPM
NASA Astrophysics Data System (ADS)
Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Fabregat, J.; Sanchez, M. E.
2009-04-01
Mathematics, created or discovered, are a global human conceptual endowment, containing large systems of knowledge, and varied skills to use definite parts of them, in creation or discovery, or for applications, e.g. in Physics, or notably in engineering behaviour. When getting upper intellectual levels in the 19th century, the agronomical science and praxis was noticeably or mainly organised in Spain in agronomical engineering schools and also in institutes, together with technician schools, also with different lower lever centres, and they have evolved with progress and they are much changing at present to a EEES schema (Bolonia process). They work in different lines that need some basis or skills from mathematics. The vocation to start such careers, that have varied curriculums, contains only some mathematics, and the number of credits for mathematics is restrained because time is necessary for other initial sciences such as applied chemistry, biology, ecology and soil sciences, but some basis and skill of maths are needed, also with Physics, at least for electricity, machines, construction, economics at initial ground levels, and also for Statistics that are here considered part of Applied Mathematics. The ways of teaching mathematical basis and skills are especial, and are different from the practical ways needed e. g. for Soil Sciences, and they involve especial efforts from students, and especial controls or exams that guide much learning. The mathematics have a very large accepted content that uses mostly a standard logic, and that is remarkably stable and international, rather similar notation and expressions being used with different main languages. For engineering the logical basis is really often not taught, but the use of it is transferred, especially for calculus that requires both adapted somehow simplified schemas and the learning of a specific skill to use it, and also for linear algebra. The basic forms of differential calculus in several variables are an example, maybe since Leibnitz, of the difficulty of balance rigor and usefulness in limited hours of teaching. In part engineers use of mathematics with manuals and now with computers that use packages, general (MAPLE, MATLAB, may be MATHCAD, et. C. ) or specific, such as for Statistics, Topography, Structural design, Hydraulics, specific Machines,…, and mostly the details of the algorithms are hidden, but the engineer must have in mind the basic mathematical schemas justifying what he is constructing with these tools, the PC being also used for organisation and drawing. The engineers must adapt to the evolution of these packages and computers that get much changed and improved in five or ten years, quicker than the specific engineering environment, and a clear idea of the much more stable mathematical structures behind gives a solid mental ground for that. An initiation to using computers also with a mathematical structure behind is necessary, to be followed in professional life. A specific actualisation of mathematical knowledge is often necessary for some new applications.
Small hydroelectric power plant for Aztec, New Mexico
DOE Office of Scientific and Technical Information (OSTI.GOV)
Frey, E.W.
1982-05-01
Preliminary engineering results and the outcome of other specific studies associated with the establishment of a hydroelectric power plant at Aztec, New Mexico, are presented, with particular emphasis on estimated costs of construction and long-term operation. Four alternative levels of effort were evaluated. Recommendations, based primarily on cost effectiveness, are presented along with material useful as a basis for a possible follow-on Phase II study. At least three levels of effort appear economically attractive alternatives for the city to pursue.
1982-07-01
of Opaque Specimens by, Broad-Band Filter Reflectometry , ASTM E 97 (1977). could be produced on a specialty basis by interested 3 TEST SPECIMEN...Aeronautics and Space Adminis- tration ( NASA ) study deals with the long-term hy- drolytic stability of urethane elastomers used with CONCLUSIONS AND...necessary for high hydrolytic stability-are not better than the polyether- solids coatings. The NASA study may be correct in based X series. The highest
NASA Technical Reports Server (NTRS)
Kobayashi, Takahisa; Simon, Donald L.
2005-01-01
In-flight sensor fault detection and isolation (FDI) is critical to maintaining reliable engine operation during flight. The aircraft engine control system, which computes control commands on the basis of sensor measurements, operates the propulsion systems at the demanded conditions. Any undetected sensor faults, therefore, may cause the control system to drive the engine into an undesirable operating condition. It is critical to detect and isolate failed sensors as soon as possible so that such scenarios can be avoided. A challenging issue in developing reliable sensor FDI systems is to make them robust to changes in engine operating characteristics due to degradation with usage and other faults that can occur during flight. A sensor FDI system that cannot appropriately account for such scenarios may result in false alarms, missed detections, or misclassifications when such faults do occur. To address this issue, an enhanced bank of Kalman filters was developed, and its performance and robustness were demonstrated in a simulation environment. The bank of filters is composed of m + 1 Kalman filters, where m is the number of sensors being used by the control system and, thus, in need of monitoring. Each Kalman filter is designed on the basis of a unique fault hypothesis so that it will be able to maintain its performance if a particular fault scenario, hypothesized by that particular filter, takes place.
2013-01-01
Background n-Butanol and isobutanol produced from biomass-derived sugars are promising renewable transport fuels and solvents. Saccharomyces cerevisiae has been engineered for butanol production, but its high butanol sensitivity poses an upper limit to product titers that can be reached by further pathway engineering. A better understanding of the molecular basis of butanol stress and tolerance of S. cerevisiae is important for achieving improved tolerance. Results By combining a screening of the haploid S. cerevisiae knock-out library, gene overexpression, and genome analysis of evolutionary engineered n-butanol-tolerant strains, we established that protein degradation plays an essential role in tolerance. Strains deleted in genes involved in the ubiquitin-proteasome system and in vacuolar degradation of damaged proteins showed hypersensitivity to n-butanol. Overexpression of YLR224W, encoding the subunit responsible for the recognition of damaged proteins of an ubiquitin ligase complex, resulted in a strain with a higher n-butanol tolerance. Two independently evolved n-butanol-tolerant strains carried different mutations in both RPN4 and RTG1, which encode transcription factors involved in the expression of proteasome and peroxisomal genes, respectively. Introduction of these mutated alleles in the reference strain increased butanol tolerance, confirming their relevance in the higher tolerance phenotype. The evolved strains, in addition to n-butanol, were also more tolerant to 2-butanol, isobutanol and 1-propanol, indicating a common molecular basis for sensitivity and tolerance to C3 and C4 alcohols. Conclusions This study shows that maintenance of protein integrity plays an essential role in butanol tolerance and demonstrates new promising targets to engineer S. cerevisiae for improved tolerance. PMID:23552365
Seismic risk management of non-engineered buildings
NASA Astrophysics Data System (ADS)
Winar, Setya
Earthquakes have long been feared as one of nature's most terrifying and devastating events. Although seismic codes clearly exist in countries with a high seismic risk to save lives and human suffering, earthquakes still continue to cause tragic events with high death tolls, particularly due to the collapse of widespread non-engineered buildings with non-seismic resistance in developing countries such as Indonesia. The implementation of seismic codes in non-engineered construction is the key to ensuring earthquake safety. In fact, such implementation is not simple, because it comprises all forms of cross disciplinary and cross sectoral linkages at different levels of understanding, commitment, and skill. This fact suggests that a widely agreed framework can help to harmonise the various perspectives. Hence, this research is aimed at developing an integrated framework for guiding and monitoring seismic risk reduction of non-engineered buildings in Indonesia via a risk management method.Primarily, the proposed framework for the study has drawn heavily on wider literature, the three existing frameworks around the world, and on the contribution of various stakeholders who participated in the study. A postal questionnaire survey, selected interviews, and workshop event constituted the primary data collection methods. As a robust framework needed to be achieved, the following two workshop events, which were conducted in Yogyakarta City and Bengkulu City in Indonesia, were carried out for practicality, validity, and moderation or any identifiable improvement requirements. The data collected was analysed with the assistance of SPSS and NVivo software programmes.This research found that the content of the proposed framework comprises 63 pairs of characteristic-indicators complemented by (a) three important factors of effective seismic risk management of non-engineered buildings, (b) three guiding principles for sustainable dissemination to the grass root communities and (c) a map of agents of change. Among the 63 pairs, there are 19 technical interventions and 44 non-technical interventions. These findings contribute to the wider knowledge in the domain of the seismic risk management of non-engineered buildings, in order to: (a) provide a basis for effective political advocacy, (b) reflect the multidimensional and inter-disciplinary nature of seismic risk reduction, (c) assist a wide range of users in determining roles, responsibilities, and accountabilities, and (d) provide the basis for setting goals and targets.
Experimental clean combustor program, phase 2
NASA Technical Reports Server (NTRS)
Roberts, R.; Peduzzi, A.; Vitti, G. E.
1976-01-01
Combustor pollution reduction technology for commercial CTOL engines was generated and this technology was demonstrated in a full-scale JT9D engine in 1976. Component rig refinement of the two best combustor concepts were tested. These concepts are the vorbix combustor, and a hybrid combustor which combines the pilot zone of the staged premix combustor and the main zone of the swirl-can combustor. Both concepts significantly reduced all pollutant emissions relative to the JT9D-7 engine combustor. However, neither concept met all program goals. The hybrid combustor met pollution goals for unburned hydrocarbons and carbon monoxide but did not achieve the oxides of nitrogen goal. This combustor had significant performance deficiencies. The Vorbix combustor met goals for unburned hydrocarbons and oxides of nitrogen but did not achieve the carbon monoxide goal. Performance of the vorbix combustor approached the engine requirements. On the basis of these results, the vorbix combustor was selected for the engine demonstration program. A control study was conducted to establish fuel control requirements imposed by the low-emission combustor concepts and to identify conceptual control system designs. Concurrent efforts were also completed on two addendums: an alternate fuels addendum and a combustion noise addendum.
Fundamentals of fluid lubrication
NASA Technical Reports Server (NTRS)
Hamrock, Bernard J.
1991-01-01
The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.
My contribution to broadening the base of chemical engineering.
Sargent, Roger W H
2011-01-01
This paper is a short account, from a personal viewpoint, of the various contributions I have made to expand the academic basis of chemical engineering from its origin in the unifying concept of unit operations, focussed on process design, to encompassing all the professional activities of industrial chemical engineers. This includes all aspects of planning and scheduling the operations as well as designing and controlling the process plant. The span of my career also happens to include the birth of the age of computing, with all the consequential implications.
Genetically engineered mouse models of melanoma.
Pérez-Guijarro, Eva; Day, Chi-Ping; Merlino, Glenn; Zaidi, M Raza
2017-06-01
Melanoma is a complex disease that exhibits highly heterogeneous etiological, histopathological, and genetic features, as well as therapeutic responses. Genetically engineered mouse (GEM) models provide powerful tools to unravel the molecular mechanisms critical for melanoma development and drug resistance. Here, we expound briefly the basis of the mouse modeling design, the available technology for genetic engineering, and the aspects influencing the use of GEMs to model melanoma. Furthermore, we describe in detail the currently available GEM models of melanoma. Cancer 2017;123:2089-103. © 2017 American Cancer Society. © 2017 American Cancer Society.
Application of reverse engineering in the medical industry.
NASA Astrophysics Data System (ADS)
Kaleev, A. A.; Kashapov, L. N.; Kashapov, N. F.; Kashapov, R. N.
2017-09-01
The purpose of this research is to develop on the basis of existing analogs new design of ophthalmologic microsurgical tweezers by using reverse engineering techniques. Virtual model was obtained by using a three-dimensional scanning system Solutionix Rexcan 450 MP. Geomagic Studio program was used to remove defects and inaccuracies of the obtained parametric model. A prototype of the finished model was made on the installation of laser stereolithography Projet 6000. Total time of the creation was 16 hours from the reverse engineering procedure to 3D-printing of the prototype.
The design of propeller blade roots
NASA Technical Reports Server (NTRS)
Cordes, G
1942-01-01
Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of propeller. The solution affords an insight into the possible introduction of different size classes of propeller.
Evaluation of advanced regenerator systems
NASA Technical Reports Server (NTRS)
Cook, J. A.; Fucinari, C. A.; Lingscheit, J. N.; Rahnke, C. J.
1978-01-01
The major considerations are discussed which will affect the selection of a ceramic regenerative heat exchanger for an improved 100 HP automotive gas turbine engine. The regenerator considered for this application is about 36cm in diameter. Regenerator comparisons are made on the basis of material, method of fabrication, cost, and performance. A regenerator inlet temperature of 1000 C is assumed for performance comparisons, and laboratory test results are discussed for material comparisons at 1100 and 1200 C. Engine test results using the Ford 707 industrial gas turbine engine are also discussed.
A Case for the Nationwide Inclusion of Engineering in the K-12 Curriculum via Technology Education
ERIC Educational Resources Information Center
Pinelli, Thomas E.; Haynie, W. James, III
2010-01-01
This paper resulted from discussions between a technology teacher educator and a colleague who has served in various education outreach roles with NASA. The basis of the paper was developed by the NASA director and two engineers, one serving with NASA and the other with the National Institute of Aerospace. The technology teacher educator read the…
Review of FY 2001 Development Work for Vitrification of Sodium Bearing Waste
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, Dean Dalton; Barnes, Charles Marshall
2002-09-01
Treatment of sodium-bearing waste (SBW) at the Idaho Nuclear Technology and Engineering Center (INTEC) within the Idaho National Engineering and Environmental Laboratory is mandated by the Settlement Agreement between the Department of Energy and the State of Idaho. This report discusses significant findings from vitrification technology development during 2001 and their impacts on the design basis for SBW vitrification.
Biological Approach to System Information Security (BASIS)
2003-12-01
Expertise J. Giordano Dr. Popyack AFRL 7 - Computer Engineering, provided by Douglas Summerville, Ph.D., Assistant Professor of the Department of...Skormin, Ph.D., Principal Investigator, Professor, Electrical and Computer Engineering, Binghamton University In addition, Joseph Giordano and Dr...worm was written by Robert Morris in 1988. But the greatest epidemics took place recently: " Melissa " in spring of 1999 and "Love Letter" in spring
Currently available medical engineering degrees in the UK. Part 1: Undergraduate degrees.
Joyce, T
2009-05-01
This paper reviews mechanical-engineering-based medical engineering degrees which are currently provided at undergraduate level in the UK. At present there are 14 undergraduate degree programmes in medical engineering, offered by the University of Bath, University of Birmingham, University of Bradford, Cardiff University, University of Hull, Imperial College London, University of Leeds, University of Nottingham, University of Oxford, Queen Mary University of London, University of Sheffield, University of Southampton, University of Surrey, and Swansea University. All these undergraduate courses are delivered on a full-time basis, both 3 year BEng and 4 year MEng degrees. Half of the 14 degree courses share a core first 2 years with a mechanical engineering stream. The other seven programmes include medical engineering modules earlier in their degrees. Within the courses, a very wide range of medical-engineering-related modules are offered, although more common modules include biomaterials, biomechanics, and anatomy and physiology.
Cogeneration Technology Alternatives Study (CTAS). Volume 2: Comparison and evaluation of results
NASA Technical Reports Server (NTRS)
1984-01-01
CTAS compared and evaluated various advanced energy conversion systems that can use coal or coal-derived fuels for industrial cogeneration applications. The principal aim of the study was to provide information needed by DOE to establish research and development (R&D) funding priorities for advanced-technology systems that could significantly advance the use of coal or coal-derived fuels in industrial cogeneration. Steam turbines, diesel engines, open-cycle gas turbines, combined cycles, closed-cycle gas turbines, Stirling engines, phosphoric acid fuel cells, molten carbonate fuel cells, and thermionics were studied with technology advancements appropriate for the 1985-2000 time period. The various advanced systems were compared and evaluated for a wide diversity of representative industrial plants on the basis of fuel energy savings, annual energy cost savings, emissions savings, and rate of return on investment (ROI) as compared with purchasing electricity from a utility and providing process heat with an on-site boiler.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tomisawa, N.
1989-07-04
This patent describes a spark ignition timing control system for an internal combustion engine, it comprises: sensor means monitoring preselected parameters for producing a sensor signal; first means for deriving a spark ignition timing on the basis of data contained in the sensor signal; second means for detecting an engine acceleration demand for producing an accelerating condition indicative signal; and third means, responsive to the accelerating condition indicative signal, for modifying the spark ignition timing derived by the first means after expiration of a first predetermined period of time of occurence of the accelerating condition indicative signal, in such amore » manner that the spark ignition timing is advanced and retarded for suppressing cycle-to-cycle fluctuation of engine speed and for smoothly increasing engine speed.« less
Tank waste remediation system systems engineering management plan
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peck, L.G.
1998-01-08
This Systems Engineering Management Plan (SEMP) describes the Tank Waste Remediation System (TWRS) implementation of the US Department of Energy (DOE) systems engineering policy provided in 97-IMSD-193. The SEMP defines the products, process, organization, and procedures used by the TWRS Project to implement the policy. The SEMP will be used as the basis for tailoring the systems engineering applications to the development of the physical systems and processes necessary to achieve the desired end states of the program. It is a living document that will be revised as necessary to reflect changes in systems engineering guidance as the program evolves.more » The US Department of Energy-Headquarters has issued program management guidance, DOE Order 430. 1, Life Cycle Asset Management, and associated Good Practice Guides that include substantial systems engineering guidance.« less
Perspective of Micro Process Engineering for Thermal Food Treatment
Mathys, Alexander
2018-01-01
Micro process engineering as a process synthesis and intensification tool enables an ultra-short thermal treatment of foods within milliseconds (ms) using very high surface-area-to-volume ratios. The innovative application of ultra-short pasteurization and sterilization at high temperatures, but with holding times within the range of ms would allow the preservation of liquid foods with higher qualities, thereby avoiding many unwanted reactions with different temperature–time characteristics. Process challenges, such as fouling, clogging, and potential temperature gradients during such conditions need to be assessed on a case by case basis and optimized accordingly. Owing to the modularity, flexibility, and continuous operation of micro process engineering, thermal processes from the lab to the pilot and industrial scales can be more effectively upscaled. A case study on thermal inactivation demonstrated the feasibility of transferring lab results to the pilot scale. It was shown that micro process engineering applications in thermal food treatment may be relevant to both research and industrial operations. Scaling of micro structured devices is made possible through the use of numbering-up approaches; however, reduced investment costs and a hygienic design must be assured. PMID:29686990
Achleitner, Stefan; De Toffol, Sara; Engelhard, Carolina; Rauch, Wolfgang
2005-04-01
The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission-water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach--at least on a temporary basis.
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.
1991-01-01
either the metallic or plastic composite pressure envelope. The ASME Boiler and Pressure Vessel Code Section 8 provides such design criteria, and the...fabricated of metallic or piastic composite materials. To preclude potential catastrophic failures of windows designed on the basis of inadequate data, in...pressure-resistant acrylic windows (reference 12). Acrylic windows are usually machined from Plexiglas G plate, which is limited in thickness to 4 inches
Experiments assigned to determine the acceleration of 8000kN shear laboratory model elements
NASA Astrophysics Data System (ADS)
Budiul Berghian, A.; Vasiu, T.; Abrudean, C.
2017-01-01
In this paper presents an experimental kinetics study by measuring accelerations using a bi-axial accelerometer constructed in the basis of a miniature integrated circuit, included in the class of micro-electrical and mechanical systems - MMA6261Q on the experimental installation reduced to the 1:5 dividing rule by comparison with the shear existent in exploitation, conceived and projected at the Faculty of Engineering in Hunedoara.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, Paul Allen
2017-02-01
The purpose of this report is to identify other disinfection methods to replace the current ozone system and propose a small pilot-scale test. Based on a review of the literature and disinfectants used by other wastewater plants in Tennessee, peracetic acid (PAA) was identified as a leading candidate. This report provides the basis for requesting approval for a pilot-scale study using PAA.
Dynamics of Space Vehicles and Space Research
1989-09-08
dynamics is used for study of longitudinal vibrations of RN, in which participates housing, power - supply system and engine installation. In American...scientific research of G. S. Narimanov. Research of the dynamics of solid bodies with the liquid filling, simulating RN and KA with ZhRD in the powered ...solid body. Page 9. Specifically, then he posed the problem about the review of the conceptual basis of research of rocket dynamics in the powered
Science and Engineering Indicators
1993-12-08
documents as well as policy documents. The Indicators report. Consistent with its congressional man- reports now serve the needs of a very wide audience date...information on science and technology Nation’s science policy ; as a basis for policymaking and as a tool for research and assessment on a worldwide basis. * to...encourage quantification of the common dimen- The success of providing valid and comparable data sions of science policy , leading to improvements in
Literature Review. Aquatic Resources Investigation, Rocky Mountain Arsenal. Phase I
1987-08-26
COMPOSITION , AND PAST MANAGEMENT RESOURCES 2. ASSESS THE CONTAMINATION HISTORY OF THOSE RESOURCES 3. PROVIDE A BASIS FOR DESIGNING MORE DETAILED PHASE II...terms of habitat, species composition , and past management practices, (2) assess the contamination history of those resources, and (3) provide a basis for...governmental documents from the Rocky Mountain Arsenal, U.S. Fish and Wildlife Service, and Army Corps of Engineers; Shell Oil Company documents; and
NASA Technical Reports Server (NTRS)
Cairelli, J.; Horvath, D.
1981-01-01
The application of alternative fuels in advanced automotive gas turbine and Stirling engines is discussed on the basis of a literature survey. These alternative engines are briefly described, and the aspects that will influence fuel selection are identified. Fuel properties and combustion properties are discussed, with consideration given to advanced materials and components. Alternative fuels from petroleum, coal, oil shale, alcohol, and hydrogen are discussed, and some background is given about the origin and production of these fuels. Fuel requirements for automotive gas turbine and Stirling engines are developed, and the need for certain reseach efforts is discussed. Future research efforts planned at Lewis are described.
An N+3 Technology Level Reference Propulsion System
NASA Technical Reports Server (NTRS)
Jones, Scott M.; Haller, William J.; Tong, Michael To-Hing
2017-01-01
An N+3 technology level engine, suitable as a propulsion system for an advanced single-aisle transport, was developed as a reference cycle for use in technology assessment and decision-making efforts. This reference engine serves three main purposes: it provides thermodynamic quantities at each major engine station, it provides overall propulsion system performance data for vehicle designers to use in their analyses, and it can be used for comparison against other proposed N+3 technology-level propulsion systems on an equal basis. This reference cycle is meant to represent the expected capability of gas turbine engines in the N+3 timeframe given reasonable extrapolations of technology improvements and the ability to take full advantage of those improvements.
de Graaf, Petra; van der Linde, E Martine; Rosier, Peter F W M; Izeta, Ander; Sievert, Karl-Dietrich; Bosch, J L H Ruud; de Kort, Laetitia M O
2017-06-01
Tissue-engineered (TE) urethra is desirable in men with urethral disease (stricture or hypospadias) and shortage of local tissue. Although ideally a TE graft would contain urethral epithelium cells, currently, bladder epithelium (urothelium) is widely used, but morphologically different. Understanding the differences and similarities of urothelium and urethral epithelium could help design a protocol for in vitro generation of urethral epithelium to be used in TE grafts for the urethra. To understand the development toward urethral epithelium or urothelium to improve TE of the urethra. A literature search was done following PRISMA guidelines. Articles describing urethral epithelium and bladder urothelium development in laboratory animals and humans were selected. Twenty-nine studies on development of urethral epithelium and 29 studies on development of urothelium were included. Both tissue linings derive from endoderm and although adult urothelium and urethral epithelium are characterized by different gene expression profiles, the signaling pathways underlying their development are similar, including Shh, BMP, Wnt, and FGF. The progenitor of the urothelium and the urethral epithelium is the early fetal urogenital sinus (UGS). The urethral plate and the urothelium are both formed from the p63+ cells of the UGS. Keratin 20 and uroplakins are exclusively expressed in urothelium, not in the urethral epithelium. Further research has to be done on unique markers for the urethral epithelium. This review has summarized the current knowledge about embryonic development of urothelium versus urethral epithelium and especially focuses on the influencing factors that are potentially specific for the eventual morphological differences of both cell linings, to be a basis for developmental or tissue engineering of urethral tissue.
NASA Astrophysics Data System (ADS)
García, Isaías; Benavides, Carmen; Alaiz, Héctor; Alonso, Angel
2013-08-01
This paper describes research on the use of knowledge models (ontologies) for building computer-aided educational software in the field of control engineering. Ontologies are able to represent in the computer a very rich conceptual model of a given domain. This model can be used later for a number of purposes in different software applications. In this study, domain ontology about the field of lead-lag compensator design has been built and used for automatic exercise generation, graphical user interface population and interaction with the user at any level of detail, including explanations about why things occur. An application called Onto-CELE (ontology-based control engineering learning environment) uses the ontology for implementing a learning environment that can be used for self and lifelong learning purposes. The experience has shown that the use of knowledge models as the basis for educational software applications is capable of showing students the whole complexity of the analysis and design processes at any level of detail. A practical experience with postgraduate students has shown the mentioned benefits and possibilities of the approach.
Fuel Cell Propulsion Systems for an All-electric Personal Air Vehicle
NASA Technical Reports Server (NTRS)
Kohout, Lisa L.; Schmitz, Paul C.
2003-01-01
There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.
Fuel Cell Propulsion Systems for an All-Electric Personal Air Vehicle
NASA Technical Reports Server (NTRS)
Kohout, Lisa L.
2003-01-01
There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.
Adaptive individual-cylinder thermal state control using intake air heating for a GDCI engine
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roth, Gregory T.; Sellnau, Mark C.
A system for a multi-cylinder compression ignition engine includes a plurality of heaters, at least one heater per cylinder, with each heater configured to heat air introduced into a cylinder. Independent control of the heaters is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the heater for that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder compression ignition engine, including determining a combustion parameter for combustion taking place in a cylinder ofmore » the engine and controlling a heater configured to heat air introduced into that cylinder, is also provided.« less
Generalized dynamic engine simulation techniques for the digital computer
NASA Technical Reports Server (NTRS)
Sellers, J.; Teren, F.
1974-01-01
Recently advanced simulation techniques have been developed for the digital computer and used as the basis for development of a generalized dynamic engine simulation computer program, called DYNGEN. This computer program can analyze the steady state and dynamic performance of many kinds of aircraft gas turbine engines. Without changes to the basic program, DYNGEN can analyze one- or two-spool turbofan engines. The user must supply appropriate component performance maps and design-point information. Examples are presented to illustrate the capabilities of DYNGEN in the steady state and dynamic modes of operation. The analytical techniques used in DYNGEN are briefly discussed, and its accuracy is compared with a comparable simulation using the hybrid computer. The impact of DYNGEN and similar all-digital programs on future engine simulation philosophy is also discussed.
Generalized dynamic engine simulation techniques for the digital computer
NASA Technical Reports Server (NTRS)
Sellers, J.; Teren, F.
1974-01-01
Recently advanced simulation techniques have been developed for the digital computer and used as the basis for development of a generalized dynamic engine simulation computer program, called DYNGEN. This computer program can analyze the steady state and dynamic performance of many kinds of aircraft gas turbine engines. Without changes to the basic program DYNGEN can analyze one- or two-spool turbofan engines. The user must supply appropriate component performance maps and design-point information. Examples are presented to illustrate the capabilities of DYNGEN in the steady state and dynamic modes of operation. The analytical techniques used in DYNGEN are briefly discussed, and its accuracy is compared with a comparable simulation using the hybrid computer. The impact of DYNGEN and similar all-digital programs on future engine simulation philosophy is also discussed.
Generalized dynamic engine simulation techniques for the digital computers
NASA Technical Reports Server (NTRS)
Sellers, J.; Teren, F.
1975-01-01
Recently advanced simulation techniques have been developed for the digital computer and used as the basis for development of a generalized dynamic engine simulation computer program, called DYNGEN. This computer program can analyze the steady state and dynamic performance of many kinds of aircraft gas turbine engines. Without changes to the basic program, DYNGEN can analyze one- or two-spool turbofan engines. The user must supply appropriate component performance maps and design point information. Examples are presented to illustrate the capabilities of DYNGEN in the steady state and dynamic modes of operation. The analytical techniques used in DYNGEN are briefly discussed, and its accuracy is compared with a comparable simulation using the hybrid computer. The impact of DYNGEN and similar digital programs on future engine simulation philosophy is also discussed.
Durability testing of the AJ10-221 490 N high performance (321 sec Isp) engine
NASA Technical Reports Server (NTRS)
Jassowski, D. M.; Rosenberg, S. D.; Schoenman, L.
1993-01-01
The durability of the 490 N AJ10-221 engine is characterized on the basis of data from 93 tests and a total firing life of 6.3 hr. For the three Ir/Re chambers tested, no limiting conditions were encountered in the 43,379 sec and 229 test thermal cycles. A wide range of off nominal operating conditions was successfully demonstrated.
Evolutionary Systems Design: Recognizing Changes in Security and Survivability Risks
2006-09-01
Unlimited distribution subject to the copyright. Technical Note CMU/SEI-2006-TN-027 The Software Engineering Institute is a federally...CARNEGIE MELLON UNIVERSITY AND SOFTWARE ENGINEERING INSTITUTE MATERIAL IS FURNISHED ON AN “AS-IS” BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF...created in the performance of Federal Government Contract Number FA8721-05-C-0003 with Carnegie Mellon University for the operation of the Software
NASA Technical Reports Server (NTRS)
Liebert, C. H.; Jacobs, R. E.; Stecura, S.; Morse, C. R.
1976-01-01
Thermal barrier ceramic coatings of stabilized zirconia over a bond coat of Ni Cr Al Y were tested for durability on air cooled turbine rotor blades in a research turbojet engine. Zirconia stabilized with either yttria, magnesia, or calcia was investigated. On the basis of durability and processing cost, the yttria stabilized zirconia was considered the best of the three coatings investigated.
Psychological tools for knowledge acquisition
NASA Technical Reports Server (NTRS)
Rueter, Henry H.; Olson, Judith Reitman
1988-01-01
Knowledge acquisition is said to be the biggest bottleneck in the development of expert systems. The problem is getting the knowledge out of the expert's head and into a computer. In cognitive psychology, characterizing metal structures and why experts are good at what they do is an important research area. Is there some way that the tools that psychologists have developed to uncover mental structure can be used to benefit knowledge engineers? We think that the way to find out is to browse through the psychologist's toolbox to see what there is in it that might be of use to knowledge engineers. Expert system developers have relied on two standard methods for extracting knowledge from the expert: (1) the knowledge engineer engages in an intense bout of interviews with the expert or experts, or (2) the knowledge engineer becomes an expert himself, relying on introspection to uncover the basis of his own expertise. Unfortunately, these techniques have the difficulty that often the expert himself isn't consciously aware of the basis of his expertise. If the expert himself isn't conscious of how he solves problems, introspection is useless. Cognitive psychology has faced similar problems for many years and has developed exploratory methods that can be used to discover cognitive structure from simple data.
Reilly, Matthew T.; Harris, R. Adron; Noronha, Antonio
2012-01-01
Over the last 50 years, researchers have made substantial progress in identifying genetic variations that underlie the complex phenotype of alcoholism. Not much is known, however, about how this genetic variation translates into altered biological function. Genetic animal models recapitulating specific characteristics of the human condition have helped elucidate gene function and the genetic basis of disease. In particular, major advances have come from the ability to manipulate genes through a variety of genetic technologies that provide an unprecedented capacity to determine gene function in the living organism and in alcohol-related behaviors. Even newer genetic-engineering technologies have given researchers the ability to control when and where a specific gene or mutation is activated or deleted, allowing investigators to narrow the role of the gene’s function to circumscribed neural pathways and across development. These technologies are important for all areas of neuroscience, and several public and private initiatives are making a new generation of genetic-engineering tools available to the scientific community at large. Finally, high-throughput “next-generation sequencing” technologies are set to rapidly increase knowledge of the genome, epigenome, and transcriptome, which, combined with genetically engineered mouse mutants, will enhance insight into biological function. All of these resources will provide deeper insight into the genetic basis of alcoholism. PMID:23134044
Reilly, Matthew T; Harris, R Adron; Noronha, Antonio
2012-01-01
Over the last 50 years, researchers have made substantial progress in identifying genetic variations that underlie the complex phenotype of alcoholism. Not much is known, however, about how this genetic variation translates into altered biological function. Genetic animal models recapitulating specific characteristics of the human condition have helped elucidate gene function and the genetic basis of disease. In particular, major advances have come from the ability to manipulate genes through a variety of genetic technologies that provide an unprecedented capacity to determine gene function in the living organism and in alcohol-related behaviors. Even newer genetic-engineering technologies have given researchers the ability to control when and where a specific gene or mutation is activated or deleted, allowing investigators to narrow the role of the gene's function to circumscribed neural pathways and across development. These technologies are important for all areas of neuroscience, and several public and private initiatives are making a new generation of genetic-engineering tools available to the scientific community at large. Finally, high-throughput "next-generation sequencing" technologies are set to rapidly increase knowledge of the genome, epigenome, and transcriptome, which, combined with genetically engineered mouse mutants, will enhance insight into biological function. All of these resources will provide deeper insight into the genetic basis of alcoholism.
A function approximation approach to anomaly detection in propulsion system test data
NASA Technical Reports Server (NTRS)
Whitehead, Bruce A.; Hoyt, W. A.
1993-01-01
Ground test data from propulsion systems such as the Space Shuttle Main Engine (SSME) can be automatically screened for anomalies by a neural network. The neural network screens data after being trained with nominal data only. Given the values of 14 measurements reflecting external influences on the SSME at a given time, the neural network predicts the expected nominal value of a desired engine parameter at that time. We compared the ability of three different function-approximation techniques to perform this nominal value prediction: a novel neural network architecture based on Gaussian bar basis functions, a conventional back propagation neural network, and linear regression. These three techniques were tested with real data from six SSME ground tests containing two anomalies. The basis function network trained more rapidly than back propagation. It yielded nominal predictions with, a tight enough confidence interval to distinguish anomalous deviations from the nominal fluctuations in an engine parameter. Since the function-approximation approach requires nominal training data only, it is capable of detecting unknown classes of anomalies for which training data is not available.
The difference engine: a model of diversity in speeded cognition.
Myerson, Joel; Hale, Sandra; Zheng, Yingye; Jenkins, Lisa; Widaman, Keith F
2003-06-01
A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.
Elements of Engineering Excellence
NASA Technical Reports Server (NTRS)
Blair, J. C.; Ryan, R. S.; Schutzenhofer
2012-01-01
The inspiration for this Contract Report (CR) originated in discussions with the director of Marshall Space Flight Center (MSFC) Engineering who asked that we investigate the question: "How do you achieve excellence in aerospace engineering?" Engineering a space system is a complex activity. Avoiding its inherent potential pitfalls and achieving a successful product is a challenge. This CR presents one approach to answering the question of how to achieve Engineering Excellence. We first investigated the root causes of NASA major failures as a basis for developing a proposed answer to the question of Excellence. The following discussions integrate a triad of Technical Understanding and Execution, Partnership with the Project, and Individual and Organizational Culture. The thesis is that you must focus on the whole process and its underlying culture, not just on the technical aspects. In addition to the engineering process, emphasis is given to the need and characteristics of a Learning Organization as a mechanism for changing the culture.
Facet‐Engineered Surface and Interface Design of Photocatalytic Materials
Wang, Lili; Li, Zhengquan
2016-01-01
The facet‐engineered surface and interface design for photocatalytic materials has been proven as a versatile approach to enhance their photocatalytic performance. This review article encompasses some recent advances in the facet engineering that has been performed to control the surface of mono‐component semiconductor systems and to design the surface and interface structures of multi‐component heterostructures toward photocatalytic applications. The review begins with some key points which should receive attention in the facet engineering on photocatalytic materials. We then discuss the synthetic approaches to achieve the facet control associated with the surface and interface design. In the following section, the facet‐engineered surface design on mono‐component photocatalytic materials is introduced, which forms a basis for the discussion on more complex systems. Subsequently, we elucidate the facet‐engineered surface and interface design of multi‐component photocatalytic materials. Finally, the existing challenges and future prospects are discussed. PMID:28105398
The development and application of CFD technology in mechanical engineering
NASA Astrophysics Data System (ADS)
Wei, Yufeng
2017-12-01
Computational Fluid Dynamics (CFD) is an analysis of the physical phenomena involved in fluid flow and heat conduction by computer numerical calculation and graphical display. The numerical method simulates the complexity of the physical problem and the precision of the numerical solution, which is directly related to the hardware speed of the computer and the hardware such as memory. With the continuous improvement of computer performance and CFD technology, it has been widely applied to the field of water conservancy engineering, environmental engineering and industrial engineering. This paper summarizes the development process of CFD, the theoretical basis, the governing equations of fluid mechanics, and introduces the various methods of numerical calculation and the related development of CFD technology. Finally, CFD technology in the mechanical engineering related applications are summarized. It is hoped that this review will help researchers in the field of mechanical engineering.
Adaptive individual-cylinder thermal state control using piston cooling for a GDCI engine
Roth, Gregory T; Husted, Harry L; Sellnau, Mark C
2015-04-07
A system for a multi-cylinder compression ignition engine includes a plurality of nozzles, at least one nozzle per cylinder, with each nozzle configured to spray oil onto the bottom side of a piston of the engine to cool that piston. Independent control of the oil spray from the nozzles is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the oil spray onto the piston in that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder engine, including determining a combustion parameter for combustion taking place in in a cylinder of the engine and controlling an oil spray targeted onto the bottom of a piston disposed in that cylinder is also presented.
Engineering and Fabrication Considerations for Cost-Effective Space Reactor Shield Development
NASA Astrophysics Data System (ADS)
Berg, Thomas A.; Disney, Richard K.
2004-02-01
Investment in developing nuclear power for space missions cannot be made on the basis of a single mission. Current efforts in the design and fabrication of the reactor module, including the reactor shield, must be cost-effective and take into account scalability and fabricability for planned and future missions. Engineering considerations for the shield need to accommodate passive thermal management, varying radiation levels and effects, and structural/mechanical issues. Considering these challenges, design principles and cost drivers specific to the engineering and fabrication of the reactor shield are presented that contribute to lower recurring mission costs.
Engineering and Fabrication Considerations for Cost-Effective Space Reactor Shield Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berg, Thomas A.; Disney, Richard K.
Investment in developing nuclear power for space missions cannot be made on the basis of a single mission. Current efforts in the design and fabrication of the reactor module, including the reactor shield, must be cost-effective and take into account scalability and fabricability for planned and future missions. Engineering considerations for the shield need to accommodate passive thermal management, varying radiation levels and effects, and structural/mechanical issues. Considering these challenges, design principles and cost drivers specific to the engineering and fabrication of the reactor shield are presented that contribute to lower recurring mission costs.
Requirements Development for the NASA Advanced Engineering Environment (AEE)
NASA Technical Reports Server (NTRS)
Rogers, Eric; Hale, Joseph P.; Zook, Keith; Gowda, Sanjay; Salas, Andrea O.
2003-01-01
The requirements development process for the Advanced Engineering Environment (AEE) is presented. This environment has been developed to allow NASA to perform independent analysis and design of space transportation architectures and technologies. Given the highly collaborative and distributed nature of AEE, a variety of organizations are involved in the development, operations and management of the system. Furthermore, there are additional organizations involved representing external customers and stakeholders. Thorough coordination and effective communication is essential to translate desired expectations of the system into requirements. Functional, verifiable requirements for this (and indeed any) system are necessary to fulfill several roles. Requirements serve as a contractual tool, configuration management tool, and as an engineering tool, sometimes simultaneously. The role of requirements as an engineering tool is particularly important because a stable set of requirements for a system provides a common framework of system scope and characterization among team members. Furthermore, the requirements provide the basis for checking completion of system elements and form the basis for system verification. Requirements are at the core of systems engineering. The AEE Project has undertaken a thorough process to translate the desires and expectations of external customers and stakeholders into functional system-level requirements that are captured with sufficient rigor to allow development planning, resource allocation and system-level design, development, implementation and verification. These requirements are maintained in an integrated, relational database that provides traceability to governing Program requirements and also to verification methods and subsystem-level requirements.
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
Surawski, N C; Miljevic, B; Ayoko, G A; Roberts, B A; Elbagir, S; Fairfull-Smith, K E; Bottle, S E; Ristovski, Z D
2011-07-01
Alternative fuels and injection technologies are a necessary component of particulate emission reduction strategies for compression ignition engines. Consequently, this study undertakes a physicochemical characterization of diesel particulate matter (DPM) for engines equipped with alternative injection technologies (direct injection and common rail) and alternative fuels (ultra low sulfur diesel, a 20% biodiesel blend, and a synthetic diesel). Particle physical properties were addressed by measuring particle number size distributions, and particle chemical properties were addressed by measuring polycyclic aromatic hydrocarbons (PAHs) and reactive oxygen species (ROS). Particle volatility was determined by passing the polydisperse size distribution through a thermodenuder set to 300 °C. The results from this study, conducted over a four point test cycle, showed that both fuel type and injection technology have an impact on particle emissions, but injection technology was the more important factor. Significant particle number emission (54%-84%) reductions were achieved at half load operation (1% increase-43% decrease at full load) with the common rail injection system; however, the particles had a significantly higher PAH fraction (by a factor of 2 to 4) and ROS concentrations (by a factor of 6 to 16) both expressed on a test-cycle averaged basis. The results of this study have significant implications for the health effects of DPM emissions from both direct injection and common rail engines utilizing various alternative fuels.
Achete, Fernanda; Van der Wegen, Mick; Roelvink, Jan Adriaan; Jaffe, Bruce E.
2017-01-01
Suspended sediment concentration is an important estuarine health indicator. Estuarine ecosystems rely on the maintenance of habitat conditions, which are changing due to direct human impact and climate change. This study aims to evaluate the impact of climate change relative to engineering measures on estuarine fine sediment dynamics and sediment budgets. We use the highly engineered San Francisco Bay-Delta system as a case study. We apply a process-based modeling approach (Delft3D-FM) to assess the changes in hydrodynamics and sediment dynamics resulting from climate change and engineering scenarios. The scenarios consider a direct human impact (shift in water pumping location), climate change (sea level rise and suspended sediment concentration decrease), and abrupt disasters (island flooding, possibly as the results of an earthquake). Levee failure has the largest impact on the hydrodynamics of the system. Reduction in sediment input from the watershed has the greatest impact on turbidity levels, which are key to primary production and define habitat conditions for endemic species. Sea level rise leads to more sediment suspension and a net sediment export if little room for accommodation is left in the system due to continuous engineering works. Mitigation measures like levee reinforcement are effective for addressing direct human impacts, but less effective for a persistent, widespread, and increasing threat like sea level rise. Progressive adaptive mitigation measures to the changes in sediment and flow dynamics resulting from sea level rise may be a more effective strategy. Our approach shows that a validated process-based model is a useful tool to address long-term (decades to centuries) changes in sediment dynamics in highly engineered estuarine systems. In addition, our modeling approach provides a useful basis for long-term, process-based studies addressing ecosystem dynamics and health.
Predicting on-site environmental impacts of municipal engineering works
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gangolells, Marta, E-mail: marta.gangolells@upc.edu; Casals, Miquel, E-mail: miquel.casals@upc.edu; Forcada, Núria, E-mail: nuria.forcada@upc.edu
2014-01-15
The research findings fill a gap in the body of knowledge by presenting an effective way to evaluate the significance of on-site environmental impacts of municipal engineering works prior to the construction stage. First, 42 on-site environmental impacts of municipal engineering works were identified by means of a process-oriented approach. Then, 46 indicators and their corresponding significance limits were determined on the basis of a statistical analysis of 25 new-build and remodelling municipal engineering projects. In order to ensure the objectivity of the assessment process, direct and indirect indicators were always based on quantitative data from the municipal engineering projectmore » documents. Finally, two case studies were analysed and found to illustrate the practical use of the proposed model. The model highlights the significant environmental impacts of a particular municipal engineering project prior to the construction stage. Consequently, preventive actions can be planned and implemented during on-site activities. The results of the model also allow a comparison of proposed municipal engineering projects and alternatives with respect to the overall on-site environmental impact and the absolute importance of a particular environmental aspect. These findings are useful within the framework of the environmental impact assessment process, as they help to improve the identification and evaluation of on-site environmental aspects of municipal engineering works. The findings may also be of use to construction companies that are willing to implement an environmental management system or simply wish to improve on-site environmental performance in municipal engineering projects. -- Highlights: • We present a model to predict the environmental impacts of municipal engineering works. • It highlights significant on-site environmental impacts prior to the construction stage. • Findings are useful within the environmental impact assessment process. • They also help contractors to implement environmental management systems.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
1982-01-01
Report XI, Technical Audit, is a compendium of research material used during the Initial Effort in making engineering comparisons and decisions. Volumes 4 and 5 of Report XI present those studies which provide a Critical Review of the Design Basis. The Critical Review Report, prepared by Intercontinental Econergy Associates, Inc., summarizes findings from an extensive review of the data base for the H-Coal process design. Volume 4 presents this review and assessment, and includes supporting material; specifically, Design Data Tabulation (Appendix A), Process Flow Sheets (Appendix B), and References (Appendix C). Volume 5 is a continuation of the references ofmore » Appendix C. Studies of a proprietary nature are noted and referenced, but are not included in these volumes. They are included in the Limited Access versions of these reports and may be reviewed by properly cleared personnel in the offices of Ashland Synthetic Fuels, Inc.« less
Evaluation and selection of open-source EMR software packages based on integrated AHP and TOPSIS.
Zaidan, A A; Zaidan, B B; Al-Haiqi, Ahmed; Kiah, M L M; Hussain, Muzammil; Abdulnabi, Mohamed
2015-02-01
Evaluating and selecting software packages that meet the requirements of an organization are difficult aspects of software engineering process. Selecting the wrong open-source EMR software package can be costly and may adversely affect business processes and functioning of the organization. This study aims to evaluate and select open-source EMR software packages based on multi-criteria decision-making. A hands-on study was performed and a set of open-source EMR software packages were implemented locally on separate virtual machines to examine the systems more closely. Several measures as evaluation basis were specified, and the systems were selected based a set of metric outcomes using Integrated Analytic Hierarchy Process (AHP) and TOPSIS. The experimental results showed that GNUmed and OpenEMR software can provide better basis on ranking score records than other open-source EMR software packages. Copyright © 2014 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Stier, Bernd; Falco, R. E.
1994-01-01
Optical measurements on an axisymmetrical quartz component engine research model were made to evaluate the flow field encountered during induction. The measurement technique is LIPA (Laser Induced Photochemical Anemometry), a non-intrusive velocimetry concept that provides an investigator of fluid flow with a tool to attain planar information about three-dimensional velocity and vorticity vectors in a single measurement step. The goal of this investigation is to further develop this measurement technique and apply it to study the induction stroke of a water analog model of a four-stroke internal combustion engine. The research conducted in the water analog model is a fundamental scientific inquiry into the flow fields that develop in the induction stroke of an engine at idling engine speeds. As this is the first investigation of its kind using LIPA technique, our goal has been to quantify, in a preliminary manner, the flow field features that develop during the intake stroke. In the process a more comprehensive understanding of the flow field features was developed, and tied to the quantification. The study evaluated the flow field of the intake stroke by estimating fields of velocity and vorticity. On the basis of these data, information about fluid dynamics during induction at engine speeds of 10, 20, and 30 RPM (corresponding to 170, 340, and 510 RPM respectively, when air is the flowing medium) for three different valve lifts was obtained. The overall development of the flow field, its energy content (kinetic, fluctuation) for the different settings of the engine parameters, vorticity information, and cyclic variations have been quantified. These have been discussed in terms of mixing performance.
Efficient High-Fidelity, Geometrically Exact, Multiphysics Structural Models
2011-10-14
fuctionally graded core. International Journal for Numerical Methods in Engineering, 68:940– 966, 2006. 7F. Shang, Z. Wang, and Z. Li. Analysis of...normal deformable plate theory and MLPG method with radial basis fuctions . Composite Structures, 80:539– 552, 2007. 17W. Zhen and W. Chen. A higher-order...functionally graded plates by using higher-order shear and normal deformable plate theory and MLPG method with radial basis fuctions . Composite Structures, 80
Experimental and Theoretical Basis for a Closed-Form Spectral BRDF Model
2015-09-17
EXPERIMENTAL AND THEORETICAL BASIS FOR A CLOSED-FORM SPECTRAL BRDF MODEL DISSERTATION Samuel D. Butler, Major, USAF AFIT-ENP-DS-15-S-021 DEPARTMENT...SPECTRAL BRDF MODEL DISSERTATION Presented to the Faculty Graduate School of Engineering and Management Air Force Institute of Technology Air University Air...FOR A CLOSED-FORM SPECTRAL BRDF MODEL DISSERTATION Samuel D. Butler, BS, MS Major, USAF Committee Membership: Michael A. Marciniak, PhD Chairman Kevin
Basic failure mechanisms in advanced composites
NASA Technical Reports Server (NTRS)
Mullin, J. V.; Mazzio, V. F.; Mehan, R. L.
1972-01-01
Failure mechanisms in carbon-epoxy composites are identified as a basis for more reliable prediction of the performance of these materials. The approach involves both the study of local fracture events in model specimens containing small groups of filaments and fractographic examination of high fiber content engineering composites. Emphasis is placed on the correlation of model specimen observations with gross fracture modes. The effects of fiber surface treatment, resin modification and fiber content are studied and acoustic emission methods are applied. Some effort is devoted to analysis of the failure process in composite/metal specimens.
Engineering solutions of environmental problems in organic waste handling
NASA Astrophysics Data System (ADS)
Briukhanov, A. Y.; Vasilev, E. V.; Shalavina, E. V.; Kucheruk, O. N.
2017-10-01
This study shows the urgent need to consider modernization of agricultural production in terms of sustainable development, which takes into account environmental implications of intensive technologies in livestock farming. Some science-based approaches are offered to address related environmental challenges. High-end technologies of organic livestock waste processing were substantiated by the feasibility study and nutrient balance calculation. The technologies were assessed on the basis of best available techniques criteria, including measures such as specific capital and operational costs associated with nutrient conservation and their delivery to the plants.
An engineering approach to automatic programming
NASA Technical Reports Server (NTRS)
Rubin, Stuart H.
1990-01-01
An exploratory study of the automatic generation and optimization of symbolic programs using DECOM - a prototypical requirement specification model implemented in pure LISP was undertaken. It was concluded, on the basis of this study, that symbolic processing languages such as LISP can support a style of programming based upon formal transformation and dependent upon the expression of constraints in an object-oriented environment. Such languages can represent all aspects of the software generation process (including heuristic algorithms for effecting parallel search) as dynamic processes since data and program are represented in a uniform format.
The Long Island Sound Dredged Material Containment Feasibility Study.
1983-02-01
ancilliary businesses, such as sporting goods stores, dockside gasoline dealers, bait and tackle shops, and fast food services would also be negatively...to there is almost always some ex- tached or unable to move fast enough maintain the area’s importance as a change of nutrients and organisms to avoid...basis, authorized depth of 14 feet or less will no longer be maintained by the Corps of (4) Fast -tracking of navigation Engineers. Presently, only 7
Changes in the Albedo of the Pegasus and Phoenix Runways, 2000-2017
2017-07-18
further reducing pavement strength and promoting more melting. To prevent or delay reaching the melt tipping point, it is critical to maintain the...2013. McMurdo Consolidated Airfields Study: Phase I, Basis of Design . ERDC/CRREL TR-13-5. Hanover, NH: U.S. Army Engineer Research and Development...Center. Haehnel, R., M. A. Knuth, T. Melendy, C. Hiemstra, and R. Davis. 2014. Design and Implementation of a Consolidated Airfield at McMurdo
Know-how and know-why in biochemical engineering.
von Stockar, U; Valentinotti, S; Marison, I; Cannizzaro, C; Herwig, C
2003-08-01
This contribution analyzes the position of biochemical engineering in general and bioprocess engineering particularly in the force fields between fundamental science and applications, and between academia and industry. By using culture technology as an example, it can be shown that bioprocess engineering has moved slowly but steadily from an empirical art concerned with mainly know-how to a science elucidating the know-why of culture behavior. Highly powerful monitoring tools enable biochemical engineers to understand and explain quantitatively the activity of cellular culture on a metabolic basis. Among these monitoring tools are not just semi-online analyses of culture broth by HPLC, GC and FIA, but, increasingly, also noninvasive methods such as midrange IR, Raman and capacitance spectroscopy, as well as online calorimetry. The detailed and quantitative insight into the metabolome and the fluxome that bioprocess engineers are establishing offers an unprecedented opportunity for building bridges between molecular biology and engineering biosciences. Thus, one of the major tasks of biochemical engineering sciences is not developing new know-how for industrial applications, but elucidating the know-why in biochemical engineering by conducting research on the underlying scientific fundamentals.
Simulant Basis for the Standard High Solids Vessel Design
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peterson, Reid A.; Fiskum, Sandra K.; Suffield, Sarah R.
The Waste Treatment and Immobilization Plant (WTP) is working to develop a Standard High Solids Vessel Design (SHSVD) process vessel. To support testing of this new design, WTP engineering staff requested that a Newtonian simulant and a non-Newtonian simulant be developed that would represent the Most Adverse Design Conditions (in development) with respect to mixing performance as specified by WTP. The majority of the simulant requirements are specified in 24590-PTF-RPT-PE-16-001, Rev. 0. The first step in this process is to develop the basis for these simulants. This document describes the basis for the properties of these two simulant types. Themore » simulant recipes that meet this basis will be provided in a subsequent document.« less
14 CFR 1215.115 - Payment and billing.
Code of Federal Regulations, 2012 CFR
2012-01-01
..., computer, human resources, etc., with the exception of TDRSS operational services, will be paid to the... NASA the user on a case-by-case basis, dependent upon level of engineering effort, long-lead items...
14 CFR 1215.115 - Payment and billing.
Code of Federal Regulations, 2011 CFR
2011-01-01
..., computer, human resources, etc., with the exception of TDRSS operational services, will be paid to the... NASA the user on a case-by-case basis, dependent upon level of engineering effort, long-lead items...
NCER is one of 7 research organizations that comprise EPAs ORD. NCERs mission is to support high-quality research by the nations leading scientists and engineers that will improve the scientific basis for national environmental decisions.
7 CFR 1942.112 - Eligible loan purposes.
Code of Federal Regulations, 2010 CFR
2010-01-01
...) of this section: (i) Reasonable fees and costs such as legal, engineering, architectural, fiscal... payment of the debts will remove any basis for any mechanic, material or other liens that may attach to...
Strategic planning toolset for reproduction of machinebuilding engines and equipment
NASA Astrophysics Data System (ADS)
Boyko, A. A.; Kukartsev, V. V.; Lobkov, K. Y.; Stupina, A. A.
2018-05-01
This article illustrates a replica of a dynamic model of machine-building equipment. The model was designed on the basis of a ‘system dynamics method’ including the Powersim Studio toolset. The given model provides the basis and delineates the reproduction process of equipment in its natural as well as appraisal forms. The presented model was employed as a tool to explore reproduction of a wide range of engines and equipment in machine-building industry. As a result of these experiments, a variety of reproducible options were revealed which include productive capacity and distribution of equipment among technology groups. The authors’ research concludes that the replica of the dynamic model designed by us has proved to be universal. This also opens the way for further research exploring a wide range of industrial equipment reproduction.
Economic communication model set
NASA Astrophysics Data System (ADS)
Zvereva, Olga M.; Berg, Dmitry B.
2017-06-01
This paper details findings from the research work targeted at economic communications investigation with agent-based models usage. The agent-based model set was engineered to simulate economic communications. Money in the form of internal and external currencies was introduced into the models to support exchanges in communications. Every model, being based on the general concept, has its own peculiarities in algorithm and input data set since it was engineered to solve the specific problem. Several and different origin data sets were used in experiments: theoretic sets were estimated on the basis of static Leontief's equilibrium equation and the real set was constructed on the basis of statistical data. While simulation experiments, communication process was observed in dynamics, and system macroparameters were estimated. This research approved that combination of an agent-based and mathematical model can cause a synergetic effect.
Zombie algorithms: a timesaving remote sensing systems engineering tool
NASA Astrophysics Data System (ADS)
Ardanuy, Philip E.; Powell, Dylan C.; Marley, Stephen
2008-08-01
In modern horror fiction, zombies are generally undead corpses brought back from the dead by supernatural or scientific means, and are rarely under anyone's direct control. They typically have very limited intelligence, and hunger for the flesh of the living [1]. Typical spectroradiometric or hyperspectral instruments providess calibrated radiances for a number of remote sensing algorithms. The algorithms typically must meet specified latency and availability requirements while yielding products at the required quality. These systems, whether research, operational, or a hybrid, are typically cost constrained. Complexity of the algorithms can be high, and may evolve and mature over time as sensor characterization changes, product validation occurs, and areas of scientific basis improvement are identified and completed. This suggests the need for a systems engineering process for algorithm maintenance that is agile, cost efficient, repeatable, and predictable. Experience on remote sensing science data systems suggests the benefits of "plug-n-play" concepts of operation. The concept, while intuitively simple, can be challenging to implement in practice. The use of zombie algorithms-empty shells that outwardly resemble the form, fit, and function of a "complete" algorithm without the implemented theoretical basis-provides the ground systems advantages equivalent to those obtained by integrating sensor engineering models onto the spacecraft bus. Combined with a mature, repeatable process for incorporating the theoretical basis, or scientific core, into the "head" of the zombie algorithm, along with associated scripting and registration, provides an easy "on ramp" for the rapid and low-risk integration of scientific applications into operational systems.
Amozegar, M; Khorasani, K
2016-04-01
In this paper, a new approach for Fault Detection and Isolation (FDI) of gas turbine engines is proposed by developing an ensemble of dynamic neural network identifiers. For health monitoring of the gas turbine engine, its dynamics is first identified by constructing three separate or individual dynamic neural network architectures. Specifically, a dynamic multi-layer perceptron (MLP), a dynamic radial-basis function (RBF) neural network, and a dynamic support vector machine (SVM) are trained to individually identify and represent the gas turbine engine dynamics. Next, three ensemble-based techniques are developed to represent the gas turbine engine dynamics, namely, two heterogeneous ensemble models and one homogeneous ensemble model. It is first shown that all ensemble approaches do significantly improve the overall performance and accuracy of the developed system identification scheme when compared to each of the stand-alone solutions. The best selected stand-alone model (i.e., the dynamic RBF network) and the best selected ensemble architecture (i.e., the heterogeneous ensemble) in terms of their performances in achieving an accurate system identification are then selected for solving the FDI task. The required residual signals are generated by using both a single model-based solution and an ensemble-based solution under various gas turbine engine health conditions. Our extensive simulation studies demonstrate that the fault detection and isolation task achieved by using the residuals that are obtained from the dynamic ensemble scheme results in a significantly more accurate and reliable performance as illustrated through detailed quantitative confusion matrix analysis and comparative studies. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
May, Gary S.
1996-07-01
The Georgia Tech SUmmer Undergraduate Packaging Research and Engineering Experience for Minorities (GT-SUPREEM) is an eight-week summer program designed to attract qualified minority students to pursue graduate degrees in packaging- related disciplines. The program is conducted under the auspices of the Georgia Tech Engineering Research Center in Low-Cost Electronic Packaging, which is sponsored by the National Science Foundation. In this program, nine junior and senior level undergraduate students are selected on a nationwide basis and paired with a faculty advisor to undertake research projects in the Packaging Research CEnter. The students are housed on campus and provided with a $DLR3,000 stipend and a travel allowance. At the conclusion of the program, the students present both oral and written project summaries. It is anticipated that this experience will motivate these students to become applicants for graduate study in ensuring years. This paper will provide an overview of the GT-SUPREEM program, including student research activities, success stories, lessons learned, and overall program outlook.
Are math readiness and personality predictive of first-year retention in engineering?
Moses, Laurie; Hall, Cathy; Wuensch, Karl; De Urquidi, Karen; Kauffmann, Paul; Swart, William; Duncan, Steve; Dixon, Gene
2011-01-01
On the basis of J. G. Borkowski, L. K. Chan, and N. Muthukrishna's model of academic success (2000), the present authors hypothesized that freshman retention in an engineering program would be related to not only basic aptitude but also affective factors. Participants were 129 college freshmen with engineering as their stated major. Aptitude was measured by SAT verbal and math scores, high school grade-point average (GPA), and an assessment of calculus readiness. Affective factors were assessed by the NEO-Five Factor Inventory (FFI; P. I. Costa & R. R. McCrae, 2007), and the Nowicki-Duke Locus of Control (LOC) scale (S. Nowicki & M. Duke, 1974). A binary logistic regression analysis found that calculus readiness and high school GPA were predictive of retention. Scores on the Neuroticism and Openness subscales from the NEO-FFI and LOC were correlated with retention status, but Openness was the only affective factor with a significant unique effect in the binary logistic regression. Results of the study lend modest support to Borkowski's model.
Preparing aircraft propulsion for a new era in energy and the environment
NASA Technical Reports Server (NTRS)
Stewart, W. L.; Nored, D. L.; Grobman, J. S.; Feiler, C. E.; Petrash, D. A.
1980-01-01
Improving fuel efficiency, new sources of jet fuel, and noise and emission control are subjects of NASA's aeronautics program. Projects aimed at attaining a 5% fuel savings for existing engines and a 13-22% savings for the next generation of turbofan engines using advanced components, and establishing a basis for turboprop-powered commercial air transports with 30-40% savings over conventional turbofan aircraft at comparable speeds and altitudes, are discussed. Fuel sources are considered in terms of reduced hydrogen and higher aromatic contents and resultant higher liner temperatures, and attention is given to lean burning, improved fuel atomization, higher freezing-point fuel, and deriving jet fuel from shale oil or coal. Noise sources including the fan, turbine, combustion process, and flow over internal struts, and attenuation using acoustic treatment, are discussed, while near-term reduction of polluting gaseous emissions at both low and high power, and far-term defining of the minimum gaseous-pollutant levels possible from turbine engines are also under study.
Continuous improvement of the quality reporting system of a medium-size company
NASA Astrophysics Data System (ADS)
Hawkins, Anthony; Onuh, Spencer
2001-10-01
Many companies are faced with quality improvement issues on a daily basis but their response to this problem varies. This paper discusses the improvement in the defect reporting system at a medium sized manufacturing company following the appointment of an experienced, motivated, design engineer to be dedicated to that task. It sets out the situation that the engineer inherited and details the changes that were incorporated; it assesses which were successful and which failed. Following a survey of current literature, it was seen that there is little written specifically on the subject of audited defect reporting. It is felt that this study goes some way to filling that void. A successful survey of engineering companies in Southern Hampshire reinforces the principle findings, that the emphasising of the Check part of Demming's Plan-Do-Check-Act cycle is a novel approach to the Quality Improvement Process, and that it has reduced the cost of rework by an audited 80% in a period of two years.
[Research-oriented experimental course of plant cell and gene engineering for undergraduates].
Xiaofei, Lin; Rong, Zheng; Morigen, Morigen
2015-04-01
Research-oriented comprehensive experimental course for undergraduates is an important part for their training of innovation. We established an optional course of plant cell and gene engineering for undergraduates using our research platform. The course is designed to study the cellular and molecular basis and experimental techniques for plant tissue culture, isolation and culture of protoplast, genetic transformation, and screening and identification of transgenic plants. To develop undergraduates' ability in experimental design and operation, and inspire their interest in scientific research and innovation consciousness, we integrated experimental teaching and practice in plant genetic engineering on the tissue, cellular, and molecular levels. Students in the course practiced an experimental teaching model featured by two-week teaching of principles, independent experimental design and bench work, and ready-to-access laboratory. In this paper, we describe the contents, methods, evaluation system and a few issues to be solved in this course, as well as the general application and significance of the research-oriented experimental course in reforming undergraduates' teaching and training innovative talents.
Development of Diesel Engine Operated Forklift Truck for Explosive Gas Atmospheres
NASA Astrophysics Data System (ADS)
Vishwakarma, Rajendra Kumar; Singh, Arvind Kumar; Ahirwal, Bhagirath; Sinha, Amalendu
2018-02-01
For the present study, a prototype diesel engine operated Forklift truck of 2 t capacity is developed for explosive gas atmosphere. The parts of the Forklift truck are assessed against risk of ignition of the explosive gases, vapors or mist grouped in Gr. IIA and having ignition temperature more than 200°C. Identification of possible sources of ignition and their control or prevention is the main objective of this work. The design transformation of a standard Forklift truck into a special Forklift truck is made on prototype basis. The safety parameters of the improved Forklift truck are discussed in this paper. The specially designed Forklift truck is useful in industries where explosive atmospheres may present during normal working conditions and risk of explosion is a concern during handling or transportation of materials. This indigenous diesel engine based Forklift truck for explosive gas atmosphere classified as Zone 1 and Zone 2 area and gas group IIA is developed first time in India in association with the Industry.
Research and application of borehole structure optimization based on pre-drill risk assessment
NASA Astrophysics Data System (ADS)
Zhang, Guohui; Liu, Xinyun; Chenrong; Hugui; Yu, Wenhua; Sheng, Yanan; Guan, Zhichuan
2017-11-01
Borehole structure design based on pre-drill risk assessment and considering risks related to drilling operation is the pre-condition for safe and smooth drilling operation. Major risks of drilling operation include lost circulation, blowout, sidewall collapsing, sticking and failure of drilling tools etc. In the study, studying data from neighboring wells was used to calculate the profile of formation pressure with credibility in the target well, then the borehole structure design for the target well assessment by using the drilling risk assessment to predict engineering risks before drilling. Finally, the prediction results were used to optimize borehole structure design to prevent such drilling risks. The newly-developed technique provides a scientific basis for lowering probability and frequency of drilling engineering risks, and shortening time required to drill a well, which is of great significance for safe and high-efficient drilling.
Cogeneration Technology Alternatives Study (CTAS). Volume 1: Summary
NASA Technical Reports Server (NTRS)
Barna, G. J.; Burns, R. K.; Sagerman, G. D.
1980-01-01
Various advanced energy conversion systems that can use coal or coal-derived fuels for industrial cogeneration applications were compared to provide information needed by DOE to establish research and development funding priorities for advanced-technology systems that could significantly advance the use of coal or coal-derived fuels in industrial cogeneration. Steam turbines, diesel engines, open-cycle gas turbines, combined cycles, closed-cycle gas turbines, Stirling engines, phosphoric acid fuel cells, molten carbonate fuel cells, and thermionics were studied with technology advancements appropriate for the 1985-2000 time period. The various advanced systems were compared and evaluated for wide diversity of representative industrial plants on the basis of fuel energy savings, annual energy cost savings, emissions savings, and rate of return on investment as compared with purchasing electricity from a utility and providing process heat with an on-site boiler. Also included in the comparisons and evaluations are results extrapolated to the national level.
Rocket Based Combined Cycle (RBCC) Engine
NASA Technical Reports Server (NTRS)
2004-01-01
Pictured is an artist's concept of the Rocket Based Combined Cycle (RBCC) launch. The RBCC's overall objective is to provide a technology test bed to investigate critical technologies associated with opperational usage of these engines. The program will focus on near term technologies that can be leveraged to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsions systems and ultimately a Single Stage To Orbit (SSTO) air breathing propulsion system.
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small fairs such as a local fair, move to a city fair, then to a regional fair, and may be chosen to represent…
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small, local fairs, move to a city fair, then to a regional fair, and may be chosen to represent that fair in…
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small, local fairs, move to a city fair, then to a regional fair, and may be chosen to represent that fair in…
1979-09-01
of skilled workers . Recently, one yard was denied a contract by MarAd on the basis that a facility did not actually have a skilled...provide two medium -size diese l engines ins tead of the s ingle engine in the or ig inal des ign, Levingston contracted with IHI for on -site design... available information, which would reside on the computer ready for use
NASA Space Engineering Research Center Symposium on VLSI Design
NASA Technical Reports Server (NTRS)
Maki, Gary K.
1990-01-01
The NASA Space Engineering Research Center (SERC) is proud to offer, at its second symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories and the electronics industry. These featured speakers share insights into next generation advances that will serve as a basis for future VLSI design. Questions of reliability in the space environment along with new directions in CAD and design are addressed by the featured speakers.
JPRS Report, Proliferation Issues
1993-05-10
its In December 1992 a group of specialists from the V.P. double standard is. Should the double standard continue Makeyev engineering design office in...They say that the "Koreans", as they are The V.P. Makeyev engineering design office is making now called in the city, suffered from big time politics...Ukrainian People’s Deputy elections to parliament on a multiparty basis. The new Mikhail Goryn stated, commenting on the results of Ukrainian Constitution, in
Engine Power Turbine and Propulsion Pod Arrangement Study
NASA Technical Reports Server (NTRS)
Robuck, Mark; Zhang, Yiyi
2014-01-01
A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing spreadsheets that generate gear tooth geometry in Catia 3D environment. Another initial goal was to link information from RomaxDESIGNER (such as hp, rpm, gear ratio) to populate Boeing's parametric weight spreadsheet and create an automated method to estimate drive system weight. This was only partially achieved due to the variety of weight models, number of manual inputs, and qualitative assessments required. A simplified weight spreadsheet was used with data inputs from RomaxDESIGNER along with manual inputs to perform rough weight calculations.
Performance of Maybach 300-horsepower airplane engine
NASA Technical Reports Server (NTRS)
Sparrow, S W
1923-01-01
This report contains the results of a test made upon a Maybach Engine in the altitude chamber of the Bureau of Standards, where controlled conditions of temperature and pressure can be made the same as those of the desired altitude. The results of this test lead to the following conclusions: from the standpoint of thermal efficiency the full-load performance of the engine is excellent at densities corresponding to altitudes up to and including 15,000 feet. The brake mean effective pressure is rather low even at wide-open throttle. This tends to give a high weight per horsepower, in as much as the weight of many engine parts is governed by the size rather than the power of the engine. At part load the thermal efficiency of the engine is low. Judged on a basis of performance the engine's chief claim to interest would appear to lie in the carburetor design, which is largely responsible excellent full-load efficiency and for its poor part-load efficiency.
Engineering cells for cell culture bioprocessing--physiological fundamentals.
Seth, Gargi; Hossler, Patrick; Yee, Joon Chong; Hu, Wei-Shou
2006-01-01
In the past decade, we have witnessed a tremendous increase in the number of mammalian cell-derived therapeutic proteins with clinical applications. The success of making these life-saving biologics available to the public is partly due to engineering efforts to enhance process efficiency. To further improve productivity, much effort has been devoted to developing metabolically engineered producing cells, which possess characteristics favorable for large-scale bioprocessing. In this article we discuss the fundamental physiological basis for cell engineering. Different facets of cellular mechanisms, including metabolism, protein processing, and the balancing pathways of cell growth and apoptosis, contribute to the complex traits of favorable growth and production characteristics. We present our assessment of the current state of the art by surveying efforts that have already been undertaken in engineering cells for a more robust process. The concept of physiological homeostasis as a key determinant and its implications on cell engineering is emphasized. Integrating the physiological perspective with cell culture engineering will facilitate attainment of dream cells with superlative characteristics.
Big geo data surface approximation using radial basis functions: A comparative study
NASA Astrophysics Data System (ADS)
Majdisova, Zuzana; Skala, Vaclav
2017-12-01
Approximation of scattered data is often a task in many engineering problems. The Radial Basis Function (RBF) approximation is appropriate for big scattered datasets in n-dimensional space. It is a non-separable approximation, as it is based on the distance between two points. This method leads to the solution of an overdetermined linear system of equations. In this paper the RBF approximation methods are briefly described, a new approach to the RBF approximation of big datasets is presented, and a comparison for different Compactly Supported RBFs (CS-RBFs) is made with respect to the accuracy of the computation. The proposed approach uses symmetry of a matrix, partitioning the matrix into blocks and data structures for storage of the sparse matrix. The experiments are performed for synthetic and real datasets.
Experimental analysis of IMEP in a rotary combustion engine
NASA Technical Reports Server (NTRS)
Schock, H. J.; Rice, W. J.; Meng, P. R.
1981-01-01
A real time indicated mean effective pressure measurement system is described which is used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate volume function in real time. Measurements at two engine speeds (2000 and 3000 rpm) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 rpm.
Mind Games: Game Engines as an Architecture for Intuitive Physics.
Ullman, Tomer D; Spelke, Elizabeth; Battaglia, Peter; Tenenbaum, Joshua B
2017-09-01
We explore the hypothesis that many intuitive physical inferences are based on a mental physics engine that is analogous in many ways to the machine physics engines used in building interactive video games. We describe the key features of game physics engines and their parallels in human mental representation, focusing especially on the intuitive physics of young infants where the hypothesis helps to unify many classic and otherwise puzzling phenomena, and may provide the basis for a computational account of how the physical knowledge of infants develops. This hypothesis also explains several 'physics illusions', and helps to inform the development of artificial intelligence (AI) systems with more human-like common sense. Copyright © 2017 Elsevier Ltd. All rights reserved.
3D printing of PLGA scaffolds for tissue engineering.
Mironov, Anton V; Grigoryev, Aleksey M; Krotova, Larisa I; Skaletsky, Nikolaj N; Popov, Vladimir K; Sevastianov, Viktor I
2017-01-01
We proposed a novel method of generation of bioresorbable polymeric scaffolds with specified architectonics for tissue engineering using extrusion three-dimensional (3D) printing with solutions of polylactoglycolide in tetraglycol with their subsequent solidifying in aqueous medium. On the basis of 3D computer models, we obtained the matrix structures with interconnected system of pores ranging in size from 0.5 to 500 µm. The results of in vitro studies using cultures of line NIH 3Т3 mouse fibroblasts, floating islet cultures of newborn rabbit pancreas, and mesenchymal stem cells of human adipose tissue demonstrated the absence of cytotoxicity and good adhesive properties of scaffolds in regard to the cell cultures chosen. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 104-109, 2017. © 2016 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Tang, Xiaolin; Yang, Wei; Hu, Xiaosong; Zhang, Dejiu
2017-02-01
In this study, based on our previous work, a novel simplified torsional vibration dynamic model is established to study the torsional vibration characteristics of a compound planetary hybrid propulsion system. The main frequencies of the hybrid driveline are determined. In contrast to vibration characteristics of the previous 16-degree of freedom model, the simplified model can be used to accurately describe the low-frequency vibration property of this hybrid powertrain. This study provides a basis for further vibration control of the hybrid powertrain during the process of engine start/stop.
Wang, Chen; Guo, Fangfang; Zhou, Heng; Zhang, Yun; Xiao, Zhigang
2013-01-01
Adipose-derived stem cells (ASCs) can differentiate into smooth muscle cells and have been engineered into elastic small diameter blood vessel walls in vitro. However, the mechanisms involved in the development of three-dimensional (3D) vascular tissue remain poorly understood. The present study analyzed protein expression profiles of engineered blood vessel walls constructed by human ASCs using methods of two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). These results were compared to normal arterial walls. A total of 1701±15 and 1265±26 protein spots from normal and engineered blood vessel wall extractions were detected by 2DE, respectively. A total of 20 spots with at least 2.0-fold changes in expression were identified, and 38 differently expressed proteins were identified by 2D electrophoresis and ion trap MS. These proteins were classified into seven functional categories: cellular organization, energy, signaling pathway, enzyme, anchored protein, cell apoptosis/defense, and others. These results demonstrated that 2DE, followed by ion trap MS, could be successfully utilized to characterize the proteome of vascular tissue, including tissue-engineered vessels. The method could also be employed to achieve a better understanding of differentiated smooth muscle protein expression in vitro. These results provide a basis for comparative studies of protein expression in vascular smooth muscles of different origin and could provide a better understanding of the mechanisms of action needed for constructing blood vessels that exhibit properties consistent with normal blood vessels. PMID:22963350
Wang, Chen; Guo, Fangfang; Zhou, Heng; Zhang, Yun; Xiao, Zhigang; Cui, Lei
2013-02-01
Adipose-derived stem cells (ASCs) can differentiate into smooth muscle cells and have been engineered into elastic small diameter blood vessel walls in vitro. However, the mechanisms involved in the development of three-dimensional (3D) vascular tissue remain poorly understood. The present study analyzed protein expression profiles of engineered blood vessel walls constructed by human ASCs using methods of two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). These results were compared to normal arterial walls. A total of 1701±15 and 1265±26 protein spots from normal and engineered blood vessel wall extractions were detected by 2DE, respectively. A total of 20 spots with at least 2.0-fold changes in expression were identified, and 38 differently expressed proteins were identified by 2D electrophoresis and ion trap MS. These proteins were classified into seven functional categories: cellular organization, energy, signaling pathway, enzyme, anchored protein, cell apoptosis/defense, and others. These results demonstrated that 2DE, followed by ion trap MS, could be successfully utilized to characterize the proteome of vascular tissue, including tissue-engineered vessels. The method could also be employed to achieve a better understanding of differentiated smooth muscle protein expression in vitro. These results provide a basis for comparative studies of protein expression in vascular smooth muscles of different origin and could provide a better understanding of the mechanisms of action needed for constructing blood vessels that exhibit properties consistent with normal blood vessels.
Traffic flow theory and chaotic behavior
DOT National Transportation Integrated Search
1989-03-01
Many commonly occurring natural systems are modeled with mathematical experessions and exhibit a certain stability. The inherent stability of these equations allows them to serve as the basis for engineering predictions. More complex models, such as ...
1993-02-01
currents can be reached by optimizing the electrode geometry and the charging circuit voltage and that the equivalent circuit modelling provides a realistic basis for analyzing plasma focus pinch dynamics.
From engineering to editing the rat genome.
Meek, Stephen; Mashimo, Tomoji; Burdon, Tom
2017-08-01
Since its domestication over 100 years ago, the laboratory rat has been the preferred experimental animal in many areas of biomedical research (Lindsey and Baker The laboratory rat. Academic, New York, pp 1-52, 2006). Its physiology, size, genetics, reproductive cycle, cognitive and behavioural characteristics have made it a particularly useful animal model for studying many human disorders and diseases. Indeed, through selective breeding programmes numerous strains have been derived that are now the mainstay of research on hypertension, obesity and neurobiology (Okamoto and Aoki Jpn Circ J 27:282-293, 1963; Zucker and Zucker J Hered 52(6):275-278, 1961). Despite this wealth of genetic and phenotypic diversity, the ability to manipulate and interrogate the genetic basis of existing phenotypes in rat strains and the methodology to generate new rat models has lagged significantly behind the advances made with its close cousin, the laboratory mouse. However, recent technical developments in stem cell biology and genetic engineering have again brought the rat to the forefront of biomedical studies and enabled researchers to exploit the increasingly accessible wealth of genome sequence information. In this review, we will describe how a breakthrough in understanding the molecular basis of self-renewal of the pluripotent founder cells of the mammalian embryo, embryonic stem (ES) cells, enabled the derivation of rat ES cells and their application in transgenesis. We will also describe the remarkable progress that has been made in the development of gene editing enzymes that enable the generation of transgenic rats directly through targeted genetic modifications in the genomes of zygotes. The simplicity, efficiency and cost-effectiveness of the CRISPR/Cas gene editing system, in particular, mean that the ability to engineer the rat genome is no longer a limiting factor. The selection of suitable targets and gene modifications will now become a priority: a challenge where ES culture and gene editing technologies can play complementary roles in generating accurate bespoke rat models for studying biological processes and modelling human disease.
Systems Engineering Provides Successful High Temperature Steam Electrolysis Project
DOE Office of Scientific and Technical Information (OSTI.GOV)
Charles V. Park; Emmanuel Ohene Opare, Jr.
2011-06-01
This paper describes two Systems Engineering Studies completed at the Idaho National Laboratory (INL) to support development of the High Temperature Stream Electrolysis (HTSE) process. HTSE produces hydrogen from water using nuclear power and was selected by the Department of Energy (DOE) for integration with the Next Generation Nuclear Plant (NGNP). The first study was a reliability, availability and maintainability (RAM) analysis to identify critical areas for technology development based on available information regarding expected component performance. An HTSE process baseline flowsheet at commercial scale was used as a basis. The NGNP project also established a process and capability tomore » perform future RAM analyses. The analysis identified which components had the greatest impact on HTSE process availability and indicated that the HTSE process could achieve over 90% availability. The second study developed a series of life-cycle cost estimates for the various scale-ups required to demonstrate the HTSE process. Both studies were useful in identifying near- and long-term efforts necessary for successful HTSE process deployment. The size of demonstrations to support scale-up was refined, which is essential to estimate near- and long-term cost and schedule. The life-cycle funding profile, with high-level allocations, was identified as the program transitions from experiment scale R&D to engineering scale demonstration.« less
Engineering Change Management Method Framework in Mechanical Engineering
NASA Astrophysics Data System (ADS)
Stekolschik, Alexander
2016-11-01
Engineering changes make an impact on different process chains in and outside the company, and lead to most error costs and time shifts. In fact, 30 to 50 per cent of development costs result from technical changes. Controlling engineering change processes can help us to avoid errors and risks, and contribute to cost optimization and a shorter time to market. This paper presents a method framework for controlling engineering changes at mechanical engineering companies. The developed classification of engineering changes and accordingly process requirements build the basis for the method framework. The developed method framework comprises two main areas: special data objects managed in different engineering IT tools and process framework. Objects from both areas are building blocks that can be selected to the overall business process based on the engineering process type and change classification. The process framework contains steps for the creation of change objects (both for overall change and for parts), change implementation, and release. Companies can select singleprocess building blocks from the framework, depending on the product development process and change impact. The developed change framework has been implemented at a division (10,000 employees) of a big German mechanical engineering company.
NASA Technical Reports Server (NTRS)
Snyder, Christopher A.; Acree, Cecil W., Jr.
2012-01-01
A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing capability. This paper performs a preliminary assessment of variable-speed power turbine technology on LCTR2 sizing, while maintaining the same, advanced technology engine core. Six concepts were studied; an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE) using a multi-speed (shifting) gearbox. There were five variable-speed power turbine (VSPT) engine concepts, comprising a matrix of either three or four turbine stages, and fixed or variable guide vanes; plus a minimum weight, twostage, fixed-geometry VSPT. The ACE is the lightest engine, but requires a multi-speed (shifting) gearbox to maximize its fuel efficiency, whereas the VSPT concepts use a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle gross and empty weight, propulsion system weight and mission fuel burn for the civil mission. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. Major study assumptions are presented and discussed. Impressive engine power-to-weight and fuel efficiency reduced vehicle sensitivity to propulsion system choice. The 10% weight penalty for multi-speed gearbox was more significant than most engine technology weight penalties to the vehicle design because drive system weight is more than two times engine weight. Based on study assumptions, fixed-geometry VSPT concept options performed better than their variable-geometry counterparts. Optimum design gross weights varied 1% or less and empty weights less than 2% among the concepts studied, while optimum fuel burns varied up to 5%. The outcome for some optimum configurations was so unexpected as to recommend a deeper look at the underlying technology assumptions.
Grouting applications in civil engineering. Volume I and II. [800 references
DOE Office of Scientific and Technical Information (OSTI.GOV)
Einstein, H.H.; Barvenik, M.J.
1975-01-01
A comprehensive description of grouting applications in civil engineering is presented that can serve as a basis for the selection of grouting methods in the borehole sealing problem. The breadth and depth of the study was assured by conducting the main part of the review, the collection and evaluation of information, without specifically considering the borehole sealing problem (but naturally incorporating any aspect of civil engineering applications that could be of potential use). Grouting is very much an art and not a science. In most cases, it is a trial and error procedure where an inexpensive method is initially triedmore » and then a more expensive one is used until the desired results are obtained. Once a desired effect is obtained, it is difficult to credit any one procedure with the success because the results are due to the summation of all the methods used. In many cases, the method that proves successful reflects a small abnormality in the ground or structure rather than its overall characteristics. Hence, successful grouting relies heavily on good engineering judgement and experience, and not on a basic set of standard correlations or equations. 800 references. (JRD)« less
Engineering Strategies to Decode and Enhance the Genomes of Coral Symbionts.
Levin, Rachel A; Voolstra, Christian R; Agrawal, Shobhit; Steinberg, Peter D; Suggett, David J; van Oppen, Madeleine J H
2017-01-01
Elevated sea surface temperatures from a severe and prolonged El Niño event (2014-2016) fueled by climate change have resulted in mass coral bleaching (loss of dinoflagellate photosymbionts, Symbiodinium spp., from coral tissues) and subsequent coral mortality, devastating reefs worldwide. Genetic variation within and between Symbiodinium species strongly influences the bleaching tolerance of corals, thus recent papers have called for genetic engineering of Symbiodinium to elucidate the genetic basis of bleaching-relevant Symbiodinium traits. However, while Symbiodinium has been intensively studied for over 50 years, genetic transformation of Symbiodinium has seen little success likely due to the large evolutionary divergence between Symbiodinium and other model eukaryotes rendering standard transformation systems incompatible. Here, we integrate the growing wealth of Symbiodinium next-generation sequencing data to design tailored genetic engineering strategies. Specifically, we develop a testable expression construct model that incorporates endogenous Symbiodinium promoters, terminators, and genes of interest, as well as an internal ribosomal entry site from a Symbiodinium virus. Furthermore, we assess the potential for CRISPR/Cas9 genome editing through new analyses of the three currently available Symbiodinium genomes. Finally, we discuss how genetic engineering could be applied to enhance the stress tolerance of Symbiodinium , and in turn, coral reefs.
The Department of the Navy Systems Engineering Career Competency Model
2015-04-30
competencies (Delgado, 2014). The SECCM has enhanced the current ENG model through the addition of extensive sets of KSAs mapped to each of the...SECCM then added KSA details from several other existing systems engineering competency models , many provided to the original NDIA SE WG, from a...to generate as complete a scope of SE KSA as possible. The ENG (formerly SPRDE) Career Field Competency Model was used as a basis for the set of
Cultivating engineering innovation ability based on optoelectronic experimental platform
NASA Astrophysics Data System (ADS)
Li, Dangjuan; Wu, Shenjiang
2017-08-01
As the supporting experimental platform of the Xi'an Technological University education reform experimental class, "optical technological innovation experimental platform" integrated the design and comprehensive experiments of the optical multi-class courses. On the basis of summing up the past two years teaching experience, platform pilot projects were improve. It has played a good role by making the use of an open teaching model in the cultivating engineering innovation spirit and scientific thinking of the students.
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small fairs such as a local fair, move to a city fair, then to a regional fair, and may be chosen to represent…
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small, local fairs, move to a city fair, then to a regional fair, and may be chosen to represent that fair in…
ERIC Educational Resources Information Center
Science Service, Inc., Washington, DC.
A science and engineering fair is a competition based on the quality of projects done by students, the results of which are reported through exhibits and oral presentations at the fair. Fairs operate on a step basis. Students who win in small fairs such as a local fair, move to a city fair, then to a regional fair, and may be chosen to represent…
Mobile Source Emissions Regulatory Compliance Data
The Engine and Vehicle Compliance Certification and Fuel Economy Inventory contains measured emissions and fuel economy compliance information for all types of vehicles (mobile sources of air pollution) excluding snowmobile, marine (diesel), and heavy duty engines whichsummary data is updated on an annual basis. Data is collected by EPA to certify compliance with the applicable fuel economy provisions of the Clean Air Act, Energy Policy and Conservation Act (EPCA) and the Energy Independent Security Act (EISA) of 2007.
Research Technology (ASTP) Rocket Based Combined Cycle (RBCC) Engine
NASA Technical Reports Server (NTRS)
2004-01-01
Pictured is an artist's concept of the Rocket Based Combined Cycle (RBCC) launch. The RBCC's overall objective is to provide a technology test bed to investigate critical technologies associated with opperational usage of these engines. The program will focus on near term technologies that can be leveraged to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsions systems and ultimately a Single Stage To Orbit (SSTO) air breathing propulsion system.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McGeer, P.; Durbin, E.
1982-01-01
The 20 invited papers presented at the world conference on alternative fuel entitled 'Methane - fuel for the future' form the basis of this book. Papers discuss: the availability of alternative fuels (natural gas, biomass conversion to methane, methane from coal conversion); technological adaptions for alternative fuels (e.g. natural gas fueled engines, methane and diesel engines); commercial experience with alternative fuel programs. (e.g. retailing of methane); and some national programs for alternative fuels. One paper has been abstracted separately.
2014-01-22
Methylene Chloride and Phenol Based Paint Removers January 22, 2014 Approved for public release; distribution is unlimited. James H. Wynne Grant C...DOCUMENTATION PAGE Form ApprovedOMB No. 0704-0188 3. DATES COVERED (From - To) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 Public ... public release; distribution is unlimited. *Stony Brook University, Department of Materials Science and Engineering, 2275 SUNY Engineering Bldg 314, Stony
Quaternary Geologic Map of the Regina 4 Degrees x 6 Degrees Quadrangle, United States and Canada
Fullerton, David S.; Christiansen, Earl A.; Schreiner, Bryan T.; Colton, Roger B.; Clayton, Lee; Bush, Charles A.; Fullerton, David S.
2007-01-01
For scientific purposes, the map differentiates Quaternary surficial deposits and materials on the basis of clast lithology or composition, matrix texture or particle size, structure, genesis, stratigraphic relations, engineering geologic properties, and relative age, as shown on the correlation diagram and indicated in the 'Description of Map Units'. Deposits of some constructional landforms, such as end moraines, are distinguished as map units. Deposits of erosional landforms, such as outwash terraces, are not distinguished, although glaciofluvial, ice-contact, fluvial, and lacustrine deposits that are mapped may be terraced. Differentiation of sequences of fluvial and glaciofluvial deposits at this scale is not possible. For practical purposes, the map is a surficial materials map. Materials are distinguished on the basis of lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized and classified in pedology or agronomy. Rather, it is a generalized map of soils as recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. As a materials map, it serves as a base from which a variety of maps for use in planning engineering, land-use planning, or land-management projects can be derived and from which a variety of maps relating to earth surface processes and Quaternary geologic history can be derived.
Exhaust emissions of low level blend alcohol fuels from two-stroke and four-stroke marine engines
NASA Astrophysics Data System (ADS)
Sevik, James M., Jr.
The U.S. Renewable Fuel Standard mandates that by 2022, 36 billion gallons of renewable fuels must be produced on a yearly basis. Ethanol production is capped at 15 billion gallons, meaning 21 billion gallons must come from different alternative fuel sources. A viable alternative to reach the remainder of this mandate is iso-butanol. Unlike ethanol, iso-butanol does not phase separate when mixed with water, meaning it can be transported using traditional pipeline methods. Iso-butanol also has a lower oxygen content by mass, meaning it can displace more petroleum while maintaining the same oxygen concentration in the fuel blend. This research focused on studying the effects of low level alcohol fuels on marine engine emissions to assess the possibility of using iso-butanol as a replacement for ethanol. Three marine engines were used in this study, representing a wide range of what is currently in service in the United States. Two four-stroke engine and one two-stroke engine powered boats were tested in the tributaries of the Chesapeake Bay, near Annapolis, Maryland over the course of two rounds of weeklong testing in May and September. The engines were tested using a standard test cycle and emissions were sampled using constant volume sampling techniques. Specific emissions for two-stroke and four-stroke engines were compared to the baseline indolene tests. Because of the nature of the field testing, limited engine parameters were recorded. Therefore, the engine parameters analyzed aside from emissions were the operating relative air-to-fuel ratio and engine speed. Emissions trends from the baseline test to each alcohol fuel for the four-stroke engines were consistent, when analyzing a single round of testing. The same trends were not consistent when comparing separate rounds because of uncontrolled weather conditions and because the four-stroke engines operate without fuel control feedback during full load conditions. Emissions trends from the baseline test to each alcohol fuel for the two-stroke engine were consistent for all rounds of testing. This is due to the fact the engine operates open-loop, and does not provide fueling compensation when fuel composition changes. Changes in emissions with respect to the baseline for iso-butanol were consistent with changes for ethanol. It was determined iso-butanol would make a viable replacement for ethanol.
Improving the quality of learning discipline “Technical thermodynamics and heat exchange” at ONMU
NASA Astrophysics Data System (ADS)
Vasserman, A. A.; Malchevsky, V. P.
2017-11-01
Discipline «Technical thermodynamics and heat exchange» creates a theoretical basis for students of ship-engineering faculty of Odessa National Maritime University to learn special subjects such as: Internal Combustion Engines, Steam and Gas Turbines, Steam Boilers, Refrigerating Plants. This course forms future specialist and provides the deep understanding of essence of thermodynamic processes which run in machines and apparatus of ship. Also different kinds of heat exchange in solid, liquid and gaseous bodies which take place almost in all technological processes are considered. The quality of training ship engineers depends on the knowledge of mentioned discipline.
Stereoscopic construction and practice of optoelectronic technology textbook
NASA Astrophysics Data System (ADS)
Zhou, Zigang; Zhang, Jinlong; Wang, Huili; Yang, Yongjia; Han, Yanling
2017-08-01
It is a professional degree course textbook for the Nation-class Specialty—Optoelectronic Information Science and Engineering, and it is also an engineering practice textbook for the cultivation of photoelectric excellent engineers. The book seeks to comprehensively introduce the theoretical and applied basis of optoelectronic technology, and it's closely linked to the current development of optoelectronic industry frontier and made up of following core contents, including the laser source, the light's transmission, modulation, detection, imaging and display. At the same time, it also embodies the features of the source of laser, the transmission of the waveguide, the electronic means and the optical processing methods.
A vibroacoustic diagnostic system as an element improving road transport safety.
Komorska, Iwona
2013-01-01
Mechanical defects of a vehicle driving system can be dangerous on the road. Diagnostic systems, which monitor operations of electric and electronic elements and devices of vehicles, are continuously developed and improved, while defects of mechanical systems are still not managed properly. This article proposes supplementing existing on-board diagnostics with a system of diagnosing selected defects to minimize their impact. It presents a method of diagnosing mechanical defects of the engine, gearbox and other elements of the driving system on the basis of a model of the vibration signal obtained adaptively. This method is suitable for engine valves, engine head gasket, main gearbox, joints, etc.
An improved method for predicting the effects of flight on jet mixing noise
NASA Technical Reports Server (NTRS)
Stone, J. R.
1979-01-01
A method for predicting the effects of flight on jet mixing noise has been developed on the basis of the jet noise theory of Ffowcs-Williams (1963) and data derived from model-jet/free-jet simulated flight tests. Predicted and experimental values are compared for the J85 turbojet engine on the Bertin Aerotrain, the low-bypass refanned JT8D engine on a DC-9, and the high-bypass JT9D engine on a DC-10. Over the jet velocity range from 280 to 680 m/sec, the predictions show a standard deviation of 1.5 dB.
Innovative Techniques Simplify Vibration Analysis
NASA Technical Reports Server (NTRS)
2010-01-01
In the early years of development, Marshall Space Flight Center engineers encountered challenges related to components in the space shuttle main engine. To assess the problems, they evaluated the effects of vibration and oscillation. To enhance the method of vibration signal analysis, Marshall awarded Small Business Innovation Research (SBIR) contracts to AI Signal Research, Inc. (ASRI), in Huntsville, Alabama. ASRI developed a software package called PC-SIGNAL that NASA now employs on a daily basis, and in 2009, the PKP-Module won Marshall s Software of the Year award. The technology is also used in many industries: aircraft and helicopter, rocket engine manufacturing, transportation, and nuclear power."
Clinical application of a light-pen computer system for quantitative angiography
NASA Technical Reports Server (NTRS)
Alderman, E. L.
1975-01-01
The important features in a clinical system for quantitative angiography were examined. The human interface for data input, whether an electrostatic pen, sonic pen, or light-pen must be engineered to optimize the quality of margin definition. The computer programs which the technician uses for data entry and computation of ventriculographic measurements must be convenient to use on a routine basis in a laboratory performing multiple studies per day. The method used for magnification correction must be continuously monitored.
A study of geothermal prospects in the western United States
NASA Technical Reports Server (NTRS)
1975-01-01
The commercial development potential of 13 underdeveloped geothermal prospects in the Western United States was examined, and the prospects were ranked in order of relative potential for development on the basis of investment considerations. The following were considered in the ranking: geotechnical and engineering data, energy market accessibility, administrative constraints, and environmental and socio-economic factors. The primary ranking criterion is the unit cost of energy production expected from each prospect. Secondary criteria are administrative constraints, environmental factors and the quality of the geotechnical data.
NASA Technical Reports Server (NTRS)
1976-01-01
Each system was chosen on the basis of its importance with respect to crew safety and mission success. An overview of the systems management is presented. The space shuttle main engine, orbiter thermal protection system, avionics, external tanks and solid rocket boosters were examined. The ground test and ground support equipment programs were studied. Program management was found to have an adequate understanding of the significant ground and flight risks involved.
Numerical investigation of bubble nonlinear dynamics characteristics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shi, Jie, E-mail: shijie@hrbeu.edu.cn; Yang, Desen; Shi, Shengguo
2015-10-28
The complicated dynamical behaviors of bubble oscillation driven by acoustic wave can provide favorable conditions for many engineering applications. On the basis of Keller-Miksis model, the influences of control parameters, including acoustic frequency, acoustic pressure and radius of gas bubble, are discussed by utilizing various numerical analysis methods, Furthermore, the law of power spectral variation is studied. It is shown that the complicated dynamic behaviors of bubble oscillation driven by acoustic wave, such as bifurcation and chaos, further the stimulated scattering processes are revealed.
Seagrave, JeanClare; Gigliotti, Andrew; McDonald, Jacob D; Seilkop, Steven K; Whitney, Kevin A; Zielinska, Barbara; Mauderly, Joe L
2005-09-01
Particulate matter (PM) and vapor-phase semivolatile organic compounds (SVOC) were collected from three buses fueled by compressed natural gas. The bus engines included a well-functioning, conventional engine; a "high emitter" engine; and a new technology engine with an oxidation catalyst. Chemical analysis of the emissions showed differences among these samples, with the high emitter sample containing markers of engine oil constituents. PM + SVOC samples were also collected for mutagenicity and toxicity testing. Extraction efficiencies from the collection media were lower than for similarly collected samples from gasoline or diesel vehicles. Responses to the recovered samples were compared on the basis of exhaust volume, to incorporate the emission rates into the potency factors. Mutagenicity was assessed by Salmonella reverse mutation assay. Mutagenicity was greatest for the high emitter sample and lowest for the new technology sample. Metabolic activation reduced mutagenicity in strain TA100, but not TA98. Toxicity, including inflammation, cytotoxicity, and parenchymal changes, was assessed 24 h after intratracheal instillation into rat lungs. Lung responses were generally mild, with little difference between the responses to equivalent volumes of emissions from the normal emitter and the new technology, but greater responses for the high emitter. These emission sample potencies are further compared on the basis of recovered mass with previously reported samples from normal and high-emitter gasoline and diesel vehicles. While mutagenic potencies for the CNG emission samples were similar to the range observed in the gasoline and diesel emission samples, lung toxicity potency factors were generally lower than those for the gasoline and diesel samples.
Precipitation Nonstationarity Effects on Water Infrastructure and Risk Management
The non-stationary precipitation regime, as increasingly recognized, affects the engineering basis and service functions of drinking water, wastewater, and stormwater infrastructures in urban centers. Small, yet significant rates of temporal precipitation change and diverse spat...
NASA Technical Reports Server (NTRS)
Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempe, E. E., Jr.
1978-01-01
A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions include carburetor lean out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity.
Universal Quantum Computing with Arbitrary Continuous-Variable Encoding.
Lau, Hoi-Kwan; Plenio, Martin B
2016-09-02
Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal quantum computation with a fixed set of operations but arbitrary encoding. By storing a qubit in the parity of two or four qumodes, all computing processes can be implemented by basis state preparations, continuous-variable exponential-swap operations, and swap tests. Our formalism inherits the advantages that the quantum information is decoupled from collective noise, and logical qubits with different encodings can be brought to interact without decoding. We also propose a possible implementation of the required operations by using interactions that are available in a variety of continuous-variable systems. Our work separates the "hardware" problem of engineering quantum-computing-universal interactions, from the "software" problem of designing encodings for specific purposes. The development of quantum computer architecture could hence be simplified.
Universal Quantum Computing with Arbitrary Continuous-Variable Encoding
NASA Astrophysics Data System (ADS)
Lau, Hoi-Kwan; Plenio, Martin B.
2016-09-01
Implementing a qubit quantum computer in continuous-variable systems conventionally requires the engineering of specific interactions according to the encoding basis states. In this work, we present a unified formalism to conduct universal quantum computation with a fixed set of operations but arbitrary encoding. By storing a qubit in the parity of two or four qumodes, all computing processes can be implemented by basis state preparations, continuous-variable exponential-swap operations, and swap tests. Our formalism inherits the advantages that the quantum information is decoupled from collective noise, and logical qubits with different encodings can be brought to interact without decoding. We also propose a possible implementation of the required operations by using interactions that are available in a variety of continuous-variable systems. Our work separates the "hardware" problem of engineering quantum-computing-universal interactions, from the "software" problem of designing encodings for specific purposes. The development of quantum computer architecture could hence be simplified.
Research on response spectrum of dam based on scenario earthquake
NASA Astrophysics Data System (ADS)
Zhang, Xiaoliang; Zhang, Yushan
2017-10-01
Taking a large hydropower station as an example, the response spectrum based on scenario earthquake is determined. Firstly, the potential source of greatest contribution to the site is determined on the basis of the results of probabilistic seismic hazard analysis (PSHA). Secondly, the magnitude and epicentral distance of the scenario earthquake are calculated according to the main faults and historical earthquake of the potential seismic source zone. Finally, the response spectrum of scenario earthquake is calculated using the Next Generation Attenuation (NGA) relations. The response spectrum based on scenario earthquake method is less than the probability-consistent response spectrum obtained by PSHA method. The empirical analysis shows that the response spectrum of scenario earthquake considers the probability level and the structural factors, and combines the advantages of the deterministic and probabilistic seismic hazard analysis methods. It is easy for people to accept and provide basis for seismic engineering of hydraulic engineering.
NASA Technical Reports Server (NTRS)
Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempke, E. R.
1976-01-01
A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions included carburetor lean-out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel-air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity. Volume II contains the data taken at each of the individual test points.
Raising of Operating a Motor Vehicle Effects on Environment in Winter
NASA Astrophysics Data System (ADS)
Ertman, S. A.; Ertman, J. A.; Zakharov, D. A.
2016-08-01
Severe low-temperature conditions, in which considerable part of Russian Motor Park is operated, affect vehicles negatively. Cold weather causes higher fuel consumption and C02 emissions always. It is because of temperature profile changing of automobile motors, other systems and materials. For enhancement of car operation efficiency in severe winter environment the dependency of engine warm-up and cooling time on ambient air temperature and wind speed described by multifactorial mathematical models is established. -On the basis of experimental research it was proved that the coolant temperature constitutes the engine representative temperature and may be used as representative temperature of engine at large. The model of generation of integrated index for vehicle adaptability to winter operating conditions by temperature profile of engines was developed. the method for evaluation of vehicle adaptability to winter operating conditions by temperature profile of engines allows to decrease higher fuel consumption in cold climate.
Bhatt, Indu; Tripathi, Bhumi Nath
2011-01-01
Nanoparticles are the materials with at least two dimensions between 1 and 100 nm. Mostly these nanoparticles are natural products but their tremendous commercial use has boosted the artificial synthesis of these particles (engineered nanoparticles). Accelerated production and use of these engineered nanoparticles may cause their release in the environment and facilitate the frequent interactions with biotic and abiotic components of the ecosystems. Despite remarkable commercial benefits, their presence in the nature may cause hazardous biological effects. Therefore, detail understanding of their sources, release interaction with environment, and possible risk assessment would provide a basis for safer use of engineered nanoparticles with minimal or no hazardous impact on environment. Keeping all these points in mind the present review provides updated information on various aspects, e.g. sources, different types, synthesis, interaction with environment, possible strategies for risk management of engineered nanoparticles. Copyright © 2010 Elsevier Ltd. All rights reserved.
Radiation shielding estimates for manned Mars space flight.
Dudkin, V E; Kovalev, E E; Kolomensky, A V; Sakovich, V A; Semenov, V F; Demin, V P; Benton, E V
1992-01-01
In the analysis of the required radiation shielding protection of spacecraft during a Mars flight, specific effects of solar activity (SA) on the intensity of galactic and solar cosmic rays were taken into consideration. Three spaceflight periods were considered: (1) maximum SA; (2) minimum SA; and (3) intermediate SA, when intensities of both galactic and solar cosmic rays are moderately high. Scenarios of spaceflights utilizing liquid-propellant rocket engines, low- and intermediate-thrust nuclear electrojet engines, and nuclear rocket engines, all of which have been designed in the Soviet Union, are reviewed. Calculations were performed on the basis of a set of standards for radiation protection approved by the U.S.S.R. State Committee for Standards. It was found that the lowest estimated mass of a Mars spacecraft, including the radiation shielding mass, obtained using a combination of a liquid propellant engine with low and intermediate thrust nuclear electrojet engines, would be 500-550 metric tons.
NASA Lewis Wind Tunnel Model Systems Criteria
NASA Technical Reports Server (NTRS)
Soeder, Ronald H.; Haller, Henry C.
1994-01-01
This report describes criteria for the design, analysis, quality assurance, and documentation of models or test articles that are to be tested in the aeropropulsion facilities at the NASA Lewis Research Center. The report presents three methods for computing model allowable stresses on the basis of the yield stress or ultimate stress, and it gives quality assurance criteria for models tested in Lewis' aeropropulsion facilities. Both customer-furnished model systems and in-house model systems are discussed. The functions of the facility manager, project engineer, operations engineer, research engineer, and facility electrical engineer are defined. The format for pretest meetings, prerun safety meetings, and the model criteria review are outlined Then, the format for the model systems report (a requirement for each model that is to be tested at NASA Lewis) is described, the engineers that are responsible for developing the model systems report are listed, and the time table for its delivery to the facility manager is given.
Application Of Holography In The Distribution Measurement Of Fuel Spraying Field In Diesel Engines
NASA Astrophysics Data System (ADS)
Xiang, He Wan; Xiong, Li Zhi
1988-01-01
The distribution of fuel spraying field in the combustion chamber is an important factor which influences the performance of diesel engines. Precise data for those major parameters of the spraying field distribution are difficult to obtain using conventional ways of measurement, so its effects on the combustion process cannot be controlled. The laser holographic measurement is used and many researches have been made on the injecting nozzles used in diesel engines Series 95, 100 and 130. These researches show that clear spraying field hologram can be taken with an "IC Engine Laser Holography System". By rendition and data processing, droplet size, amount and their space distribution in the spraying; the spraying range, cone angle and other dependable data can be obtained. Therefore, the spraying quality of an injecting nozzle can be precisely determined, which provides reliable basis for the improvement of diesel engines' functions.
Structural Basis for the Altered PAM Recognition by Engineered CRISPR-Cpf1.
Nishimasu, Hiroshi; Yamano, Takashi; Gao, Linyi; Zhang, Feng; Ishitani, Ryuichiro; Nureki, Osamu
2017-07-06
The RNA-guided Cpf1 nuclease cleaves double-stranded DNA targets complementary to the CRISPR RNA (crRNA), and it has been harnessed for genome editing technologies. Recently, Acidaminococcus sp. BV3L6 (AsCpf1) was engineered to recognize altered DNA sequences as the protospacer adjacent motif (PAM), thereby expanding the target range of Cpf1-mediated genome editing. Whereas wild-type AsCpf1 recognizes the TTTV PAM, the RVR (S542R/K548V/N552R) and RR (S542R/K607R) variants can efficiently recognize the TATV and TYCV PAMs, respectively. However, their PAM recognition mechanisms remained unknown. Here we present the 2.0 Å resolution crystal structures of the RVR and RR variants bound to a crRNA and its target DNA. The structures revealed that the RVR and RR variants primarily recognize the PAM-complementary nucleotides via the substituted residues. Our high-resolution structures delineated the altered PAM recognition mechanisms of the AsCpf1 variants, providing a basis for the further engineering of CRISPR-Cpf1. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Aleiferis, P. G.; Hardalupas, Y.; Taylor, A. M. K. P.; Ishii, K.; Urata, Y.
2005-11-01
Lean-burn spark-ignition engines exhibit higher efficiency and lower specific emissions in comparison with stoichiometrically charged engines. However, as the air-to-fuel (A/F) ratio of the mixture is made leaner than stoichiometric, cycle-by-cycle variations in the early stages of in-cylinder combustion, and subsequent indicated mean effective pressure (IMEP), become more pronounced and limit the range of lean-burn operation. Viable lean-burn engines promote charge stratification, the mixture near the spark plug being richer than the cylinder volume averaged value. Recent work has shown that cycle-by-cycle variations in the early stages of combustion in a stratified-charge engine can be associated with variations in both the local value of A/F ratio near the spark plug around ignition timing, as well as in the volume averaged value of the A/F ratio. The objective of the current work was to identify possible sources of such variability in A/F ratio by studying the in-cylinder field of fuel-droplet distribution during the early intake stroke. This field was visualised in an optical single-cylinder 4-valve pentroof-type spark-ignition engine by means of laser-sheet illumination in planes parallel to the cylinder head gasket 6 and 10 mm below the spark plug. The engine was run with port-injected isooctane at 1500 rpm with 30% volumetric efficiency and air-to-fuel ratio corresponding to both stoichiometric firing (A/F=15, Φ =1.0) and mixture strength close to the lean limit of stable operation (A/F=22, Φ =0.68). Images of Mie intensity scattered by the cloud of fuel droplets were acquired on a cycle-by-cycle basis. These were studied in order to establish possible correlations between the cyclic variations in size, location and scattered-light intensity of the cloud of droplets with the respective variations in IMEP. Because of the low level of Mie intensity scattered by the droplets and because of problems related to elastic scattering on the walls of the combustion chamber, as well as problems related to engine “rocking” at the operating conditions close to the misfire limit, the acquired images were processed for background subtraction by using a PIV-based data correction algorithm. After this processing, the arrival and leaving timings of fuel droplets into the illuminated plane were found not to vary significantly on a cycle-by-cycle basis but the recorded cycle-by-cycle variations in Mie intensity suggested that the amount of fuel in the cylinder could have been 6 26% greater for the “strong” cycles with IMEP 115% higher than the average IMEP, than the ones imaged for “weak” cycles at less than 85% the average IMEP. This would correspond to a maximum cyclic variability in the in-cylinder equivalence ratio Φ of the order of 0.17.
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.
Kaimal, Viswanath K; Vijayabalan, P
2016-05-01
The demand for plastic is ever increasing and has produced a huge amount of plastic waste. The management and disposal of plastic waste have become a major concern, especially in developing cities. The idea of waste to energy recovery is one of the promising techniques used for managing the waste plastic. This paper assesses the potential of using Waste Plastic Oil (WPO), synthesized using pyrolysis of waste plastic, as an alternative for diesel fuel. In this research work, the performance and emission characteristics of a single cylinder diesel engine fuelled with WPO and its blends with diesel are studied. In addition to neat plastic oil, three blends (PO25, PO50 and PO75) were prepared on a volumetric basis and the engine was able to run on neat plastic oil. Brake thermal efficiency of blends was lower compared to diesel, but PO25 showed similar performance to that of diesel. The emissions were reduced considerably while using blends when compared to neat plastic oil. The smoke and NOX were reduced by 22% and 17.8% respectively for PO25 than that of plastic oil. Copyright © 2016 Elsevier Ltd. All rights reserved.
Metabolic regulation in solventogenic clostridia: regulators, mechanisms and engineering.
Yang, Yunpeng; Nie, Xiaoqun; Jiang, Yuqian; Yang, Chen; Gu, Yang; Jiang, Weihong
2018-02-22
Solventogenic clostridia, a group of important industrial microorganisms, have exceptional substrate and product diversity, capable of producing a series of two-carbon and even long-chain chemicals and fuels by using various substrates, including sugars, cellulose and hemicellulose, and C1 gases. For the sake of in-depth understanding and engineering these anaerobic microorganisms for broader applications, studies on metabolic regulation of solventogenic clostridia had been extensively carried out during the past ten years, based on the rapid development of various genetic tools. To date, a number of regulators that are essential for cell physiological and metabolic processes have been identified in clostridia, and the relevant mechanisms have also been dissected, providing a wealth of valuable information for metabolic engineering. Here, we reviewed the latest research progresses on the metabolic regulation for chemical production and substrate utilization in solventogenic clostridia, by focusing on three typical Clostridium species, the saccharolytic C. acetobutylicum and C. beijerinckii, as well as the gas-fermenting C. ljungdahlii. On this basis, future directions in the study and remodeling of clostridial regulation systems, were proposed for effective modification of these industrially important anaerobes. Copyright © 2018 Elsevier Inc. All rights reserved.
Fu, Qiang; Deng, Chen-Liang; Zhao, Ren-Yan; Wang, Ying; Cao, Yilin
2014-01-01
Urethral defects are common and frequent disorders and are difficult to treat. Simple natural or synthetic materials do not provide a satisfactory curative solution for long urethral defects, and urethroplasty with large areas of autologous tissues is limited and might interfere with wound healing. In this study, adipose-derived stem cells were used. These cells can be derived from a wide range of sources, have extensive expansion capability, and were combined with oral mucosal epithelial cells to solve the problem of finding seeding cell sources for producing the tissue-engineered urethras. We also used the synthetic biodegradable polymer poly-glycolic acid (PGA) as a scaffold material to overcome issues such as potential pathogen infections derived from natural materials (such as de-vascular stents or animal-derived collagen) and differing diameters. Furthermore, we used a bioreactor to construct a tissue-engineered epithelial-muscular lumen with a double-layer structure (the epithelial lining and the muscle layer). Through these steps, we used an epithelial-muscular lumen built in vitro to repair defects in a canine urethral defect model (1 cm). Canine urethral reconstruction was successfully achieved based on image analysis and histological techniques at different time points. This study provides a basis for the clinical application of tissue engineering of an epithelial-muscular lumen. Copyright © 2013 Elsevier Ltd. All rights reserved.
The Sensitivity of Precooled Air-Breathing Engine Performance to Heat Exchanger Design Parameters
NASA Astrophysics Data System (ADS)
Webber, H.; Bond, A.; Hempsell, M.
The issues relevant to propulsion design for Single Stage To Orbit (SSTO) vehicles are considered. In particular two air- breathing engine concepts involving precooling are compared; SABRE (Synergetic Air-Breathing and Rocket Engine) as designed for the Skylon SSTO launch vehicle, and a LACE (Liquid Air Cycle Engine) considered in the 1960's by the Americans for an early generation spaceplane. It is shown that through entropy minimisation the SABRE has made substantial gains in performance over the traditional LACE precooled engine concept, and has shown itself as the basis of a viable means of realising a SSTO vehicle. Further, it is demonstrated that the precooler is a major source of thermodynamic irreversibility within the engine cycle and that further reduction in entropy can be realised by increasing the heat transfer coefficient on the air side of the precooler. If this were to be achieved, it would improve the payload mass delivered to orbit by the Skylon launch vehicle by between 5 and 10%.
Technology of interdisciplinary open-ended designing in engineering education
NASA Astrophysics Data System (ADS)
Isaev, A. P.; Plotnikov, L. V.; Fomin, N. I.
2017-11-01
Author’s technology of interdisciplinary open-ended engineering is presented in this article. This technology is an integrated teaching method that significantly increases the practical component in the educational program. Author’s technology creates the conditions to overcome the shortcomings in the engineering education. The basic ideas of the technology of open-ended engineering, experience of their implementation in higher education and the author’s vision of the teaching technology are examined in the article. The main stages of development process of the author’s technology of open-ended engineering to prepare students (bachelor) of technical profile are presented in the article. Complex of the methodological tools and procedures is shown in the article. This complex is the basis of the developed training technology that is used in educational process in higher school of engineering (UrFU). The organizational model of the technology of open-ended engineering is presented. Organizational model integrates the functions in the creation and implementation of all educational program. Analysis of the characteristics of educational activity of students working on author’s technology of interdisciplinary open-ended engineering is presented. Intermediate results of the application of author’s technology in the educational process of the engineering undergraduate are shown.
Safety analysis report for the Waste Storage Facility. Revision 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bengston, S.J.
1994-05-01
This safety analysis report outlines the safety concerns associated with the Waste Storage Facility located in the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The three main objectives of the report are: define and document a safety basis for the Waste Storage Facility activities; demonstrate how the activities will be carried out to adequately protect the workers, public, and environment; and provide a basis for review and acceptance of the identified risk that the managers, operators, and owners will assume.
Modeling of Autovariator Operation as Power Components Adjuster in Adaptive Machine Drives
NASA Astrophysics Data System (ADS)
Balakin, P. D.; Belkov, V. N.; Shtripling, L. O.
2018-01-01
Full application of the available power and stationary mode preservation for the power station (engine) operation of the transport machine under the conditions of variable external loading, are topical issues. The issues solution is possible by means of mechanical drives with the autovaried rate transfer function and nonholonomic constraint of the main driving mediums. Additional to the main motion, controlled motion of the driving mediums is formed by a variable part of the transformed power flow and is implemented by the integrated control loop, functioning only on the basis of the laws of motion. The mathematical model of the mechanical autovariator operation is developed using Gibbs function, acceleration energy; the study results are presented; on their basis, the design calculations of the autovariator driving mediums and constraints, including its automatic control loop, are possible.
Fusion of Tracks with Road Constraints
2008-06-12
of orthogonality, the projec- tion error vector »¡ »D is orthogonal to D, i.e., each and every basis of it: h»¡ »D, dii = h»¡DTc, dii = dTi (»¡DTc) = 0, i... Electrical Engineers, 2004. [13] M. Ulmke and W. Koch Multi hypothesis track extraction and maintenance of GMTI sensor data. In Proceedings of the 8th...in Annapolis, MD (2000) and in Philadelphia, PA (2005), respectively. Dr. Yang is also an Adjunct Professor of Electrical and Computer Engineering at
2017-06-09
28. 16 Ibid., 37. 17 Ibid., 136. 12 unsuccessful due to wind and tide issues which enabled two British ships to elude the slow vessel.18...question of air supply was at one time one of the most difficult problems to solve on paper with which early experimenters with submarines had to contend...recently introduced the constant pressure engine. This engine was the basis for the gas turbine , and his design of constant pressure is now referred to
Periodontics--tissue engineering and the future.
Douglass, Gordon L
2005-03-01
Periodontics has a long history of utilizing advances in science to expand and improve periodontal therapies. Recently the American Academy of Periodontology published the findings of the Contemporary Science Workshop, which conducted state-of-the-art evidence-based reviews of current and emerging areas in periodontics. The findings of this workshop provide the basis for an evidence-based approach to periodontal therapy. While the workshop evaluated all areas of periodontics, it is in the area of tissue engineering that the most exciting advances are becoming a reality.
The Algorithm Theoretical Basis Document for Level 1A Processing
NASA Technical Reports Server (NTRS)
Jester, Peggy L.; Hancock, David W., III
2012-01-01
The first process of the Geoscience Laser Altimeter System (GLAS) Science Algorithm Software converts the Level 0 data into the Level 1A Data Products. The Level 1A Data Products are the time ordered instrument data converted from counts to engineering units. This document defines the equations that convert the raw instrument data into engineering units. Required scale factors, bias values, and coefficients are defined in this document. Additionally, required quality assurance and browse products are defined in this document.
Harrier Information Management System (HIMS): The system and the approach
NASA Astrophysics Data System (ADS)
Reynolds, D. J.
1990-01-01
The Harrier GR5 is to be fleet-fitted with an engine monitoring system. The ground station known as HIMS was developed to enable engineers to analyze parameter exceedance and component life count data collected from it. The HIMS and its development program are reviewed. Counts can vary from aircraft to aircraft for a given number of flying hours and lifting on this basis is expected to yield considerable savings. Aspects relevant to future aircraft health monitoring programs are considered.
NASA Astrophysics Data System (ADS)
Qi, Bin; Guo, Linli; Zhang, Zhixian
2016-07-01
Space life science and life support engineering are prominent problems in manned deep space exploration mission. Some typical problems are discussed in this paper, including long-term life support problem, physiological effect and defense of varying extraterrestrial environment. The causes of these problems are developed for these problems. To solve these problems, research on space life science and space medical-engineering should be conducted. In the aspect of space life science, the study of space gravity biology should focus on character of physiological effect in long term zero gravity, co-regulation of physiological systems, impact on stem cells in space, etc. The study of space radiation biology should focus on target effect and non-target effect of radiation, carcinogenicity of radiation, spread of radiation damage in life system, etc. The study of basic biology of space life support system should focus on theoretical basis and simulating mode of constructing the life support system, filtration and combination of species, regulation and optimization method of life support system, etc. In the aspect of space medical-engineering, the study of bio-regenerative life support technology should focus on plants cultivation technology, animal-protein production technology, waste treatment technology, etc. The study of varying gravity defense technology should focus on biological and medical measures to defend varying gravity effect, generation and evaluation of artificial gravity, etc. The study of extraterrestrial environment defense technology should focus on risk evaluation of radiation, monitoring and defending of radiation, compound prevention and removal technology of dust, etc. At last, a case of manned lunar base is analyzed, in which the effective schemes of life support system, defense of varying gravity, defense of extraterrestrial environment are advanced respectively. The points in this paper can be used as references for intensive study on key technologies.
Prediction of in-use emissions of heavy-duty diesel vehicles from engine testing.
Yanowitz, Janet; Graboski, Michael S; McCormick, Robert L
2002-01-15
A model of a heavy-duty vehicle driveline with automatic transmission has been developed for estimating engine speed and load from vehicle speed. The model has been validated using emissions tests conducted on three diesel vehicles on a chassis dynamometer and then on the engines removed from the vehicles tested on an engine dynamometer. Nitrogen oxide (NOx) emissions were proportional to work done by the engine. For two of the engines, the NOx/horsepower(HP) ratio was the same on the engine and on the chassis dynamometer tests. For the third engine NOx/HP was significantly higher from the chassis test, possibly due to the use of dual engine maps. The engine certification test generated consistently less particulate matter emissions on a gram per brake horsepower-hour basis than the Heavy Duty Transient and Central Business District chassis cycles. A good linear correlation (r2 = 0.97 and 0.91) was found between rates of HP increase integrated over the test cycle and PM emissions for both the chassis and the engine tests for two of the vehicles. The model also shows how small changes in vehicle speeds can lead to a doubling of load on the engine. Additionally, the model showed that it is impossible to drive a vehicle cycle equivalent to the heavy-duty engine federal test procedure on these vehicles.
Artificial gravity studies and design considerations for Space Station centrifuges
NASA Technical Reports Server (NTRS)
Halstead, T. W.; Brown, A. H.; Fuller, C. A.; Oyama, J.
1984-01-01
The requirements to and capabilities of a Space Station biological facility centrifuge are discussed on the basis of an assessment of the objectives and subjects of future microgravity biological experiments. It is argued that the facility should be capable of both acute and extended chronic exposure of test subjects and biological materials to altered-g loading. In addition, the experimental approaches and equipment for microgravity studies on a Space Station are outlined. Finally, the engineering requirements of such a centrifuge are examined, with consideration of radial gravity gradients, size, and physical access to animals.
Alander, Timo J A; Leskinen, Ari P; Raunemaa, Taisto M; Rantanen, Leena
2004-05-01
Diesel exhaust particles are the major constituent of urban carbonaceous aerosol being linked to a large range of adverse environmental and health effects. In this work, the effects of fuel reformulation, oxidation catalyst, engine type, and engine operation parameters on diesel particle emission characteristics were investigated. Particle emissions from an indirect injection (IDI) and a direct injection (DI) engine car operating under steady-state conditions with a reformulated low-sulfur, low-aromatic fuel and a standard-grade fuel were analyzed. Organic (OC) and elemental (EC) carbon fractions of the particles were quantified by a thermal-optical transmission analysis method and particle size distributions measured with a scanning mobility particle sizer (SMPS). The particle volatility characteristics were studied with a configuration that consisted of a thermal desorption unit and an SMPS. In addition, the volatility of size-selected particles was determined with a tandem differential mobility analyzer technique. The reformulated fuel was found to produce 10-40% less particulate carbon mass compared to the standard fuel. On the basis of the carbon analysis, the organic carbon contributed 27-61% to the carbon mass of the IDI engine particle emissions, depending on the fuel and engine operation parameters. The fuel reformulation reduced the particulate organic carbon emissions by 10-55%. In the particles of the DI engine, the organic carbon contributed 14-26% to the total carbon emissions, the advanced engine technology, and the oxidation catalyst, thus reducing the OC/EC ratio of particles considerably. A relatively good consistency between the particulate organic fraction quantified with the thermal optical method and the volatile fraction measured with the thermal desorption unit and SMPS was found.
Cellular nanotechnology: making biological interfaces smarter.
Mendes, Paula M
2013-12-21
Recently, there has been an outburst of research on engineered cell-material interfaces driven by nanotechnology and its tools and techniques. This tutorial review begins by providing a brief introduction to nanostructured materials, followed by an overview of the wealth of nanoscale fabrication and analysis tools available for their development. This background serves as the basis for a discussion of early breakthroughs and recent key developments in the endeavour to develop nanostructured materials as smart interfaces for fundamental cellular studies, tissue engineering and regenerative medicine. The review covers three major aspects of nanostructured interfaces - nanotopographical control, dynamic behaviour and intracellular manipulation and sensing - where efforts are continuously being made to further understand cell function and provide new ways to control cell behaviour. A critical reflection of the current status and future challenges are discussed as a conclusion to the review.
Experimental comparisons of hypothesis test and moving average based combustion phase controllers.
Gao, Jinwu; Wu, Yuhu; Shen, Tielong
2016-11-01
For engine control, combustion phase is the most effective and direct parameter to improve fuel efficiency. In this paper, the statistical control strategy based on hypothesis test criterion is discussed. Taking location of peak pressure (LPP) as combustion phase indicator, the statistical model of LPP is first proposed, and then the controller design method is discussed on the basis of both Z and T tests. For comparison, moving average based control strategy is also presented and implemented in this study. The experiments on a spark ignition gasoline engine at various operating conditions show that the hypothesis test based controller is able to regulate LPP close to set point while maintaining the rapid transient response, and the variance of LPP is also well constrained. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.
Two-tiered design analysis of a radiator for a solar dynamic powered Stirling engine
NASA Technical Reports Server (NTRS)
Hainley, Donald C.
1989-01-01
Two separate design approaches for a pumped loop radiator used to transfer heat from the cold end of a solar dynamic powered Stirling engine are described. The first approach uses a standard method to determine radiator requirements to meet specified end of mission conditions. Trade-off studies conducted for the analysis are included. Justification of this concept within the specified parameters of the analysis is provided. The second design approach determines the life performance of the radiator/Stirling system. In this approach, the system performance was altered by reducing the radiator heat transfer area. Performance effects and equilibrium points were determined as radiator segments were removed. This simulates the effect of loss of radiator sections due to micro-meteoroid and space debris penetration. The two designs were compared on the basis of overall system requirements and goals.
Two-tiered design analysis of a radiator for a solar dynamic powered Stirling engine
NASA Technical Reports Server (NTRS)
Hainley, Donald C.
1989-01-01
Two separate design approaches for a pumped loop radiator used to transfer heat from the cold end of a solar dynamic powered Stirling engine are described. The first approach uses a standard method to determine radiator requirements to meet specified end of mission conditions. Trade-off studies conducted for the analysis are included. Justification of this concept within the specified parameters of the analysis is provided. The second design approach determines the life performance of the radiator/Stirling system. In this approach, the system performance was altered by reducing the radiator heat transfer area. Performance effects and equilibrium points were determined as radiator segments were removed. This simulates the effect of loss of radiator sections due to micro-meteoroid and space debris penetration. The two designs are compared on the basis of overall system requirements and goals.
Fault Diagnosis of Demountable Disk-Drum Aero-Engine Rotor Using Customized Multiwavelet Method.
Chen, Jinglong; Wang, Yu; He, Zhengjia; Wang, Xiaodong
2015-10-23
The demountable disk-drum aero-engine rotor is an important piece of equipment that greatly impacts the safe operation of aircraft. However, assembly looseness or crack fault has led to several unscheduled breakdowns and serious accidents. Thus, condition monitoring and fault diagnosis technique are required for identifying abnormal conditions. Customized ensemble multiwavelet method for aero-engine rotor condition identification, using measured vibration data, is developed in this paper. First, customized multiwavelet basis function with strong adaptivity is constructed via symmetric multiwavelet lifting scheme. Then vibration signal is processed by customized ensemble multiwavelet transform. Next, normalized information entropy of multiwavelet decomposition coefficients is computed to directly reflect and evaluate the condition. The proposed approach is first applied to fault detection of an experimental aero-engine rotor. Finally, the proposed approach is used in an engineering application, where it successfully identified the crack fault of a demountable disk-drum aero-engine rotor. The results show that the proposed method possesses excellent performance in fault detection of aero-engine rotor. Moreover, the robustness of the multiwavelet method against noise is also tested and verified by simulation and field experiments.
A data management system for weight control and design-to-cost
NASA Technical Reports Server (NTRS)
Bryant, J. C.
1978-01-01
The definition of the mass properties data of aircraft changed on a daily basis as do design details of the aircraft. This dynamic nature of the definition has generally encouraged those responsible for the data to update the data on a weekly or monthly basis. The by-product of these infrequent updates was the requirement of manual records to maintain daily activity. The development of WAVES changed the approach to management of mass properties data. WAVES has given the ability to update the data on a daily basis thereby eliminating the need for manual records. WAVES has demonstrated that a software product can support a data management system for engineering data.
Extending Clause Learning of SAT Solvers with Boolean Gröbner Bases
NASA Astrophysics Data System (ADS)
Zengler, Christoph; Küchlin, Wolfgang
We extend clause learning as performed by most modern SAT Solvers by integrating the computation of Boolean Gröbner bases into the conflict learning process. Instead of learning only one clause per conflict, we compute and learn additional binary clauses from a Gröbner basis of the current conflict. We used the Gröbner basis engine of the logic package Redlog contained in the computer algebra system Reduce to extend the SAT solver MiniSAT with Gröbner basis learning. Our approach shows a significant reduction of conflicts and a reduction of restarts and computation time on many hard problems from the SAT 2009 competition.
Henkel, Marius; Zwick, Michaela; Beuker, Janina; Willenbacher, Judit; Baumann, Sandra; Oswald, Florian; Neumann, Anke; Siemann-Herzberg, Martin; Syldatk, Christoph; Hausmann, Rudolf
2015-01-01
Bioprocess engineering is a highly interdisciplinary field of study which is strongly benefited by practical courses where students can actively experience the interconnection between biology, engineering, and physical sciences. This work describes a lab course developed for 2nd year undergraduate students of bioprocess engineering and related disciplines, where students are challenged with a real-life bioprocess-engineering application, the production of recombinant protein in a fed-batch process. The lab course was designed to introduce students to the subject of operating and supervising an experiment in a bioreactor, along with the analysis of collected data and a final critical evaluation of the experiment. To provide visual feedback of the experimental outcome, the organism used during class was Escherichia coli which carried a plasmid to recombinantly produce enhanced green fluorescent protein (eGFP) upon induction. This can easily be visualized in both the bioreactor and samples by using ultraviolet light. The lab course is performed with bioreactors of the simplest design, and is therefore highly flexible, robust and easy to reproduce. As part of this work the implementation and framework, the results, the evaluation and assessment of student learning combined with opinion surveys are presented, which provides a basis for instructors intending to implement a similar lab course at their respective institution. © 2015 by the International Union of Biochemistry and Molecular Biology.
Biopharmaceutics and Therapeutic Potential of Engineered Nanomaterials
Liang, Xing-Jie; Chen, Chunying; Zhao, Yuliang; Jia, Lee; Wang, Paul C.
2009-01-01
Engineered nanomaterials are at the leading edge of the rapidly developing nanosciences and are founding an important class of new materials with specific physicochemical properties different from bulk materials with the same compositions. The potential for nanomaterials is rapidly expanding with novel applications constantly being explored in different areas. The unique size-dependent properties of nanomaterials make them very attractive for pharmaceutical applications. Investigations of physical, chemical and biological properties of engineered nanomaterials have yielded valuable information. Cytotoxic effects of certain engineered nanomaterials towards malignant cells form the basis for one aspect of nanomedicine. It is inferred that size, three dimensional shape, hydrophobicity and electronic configurations make them an appealing subject in medicinal chemistry. Their unique structure coupled with immense scope for derivatization forms a base for exciting developments in therapeutics. This review article addresses the fate of absorption, distribution, metabolism and excretion (ADME) of engineered nanoparticles in vitro and in vivo. It updates the distinctive methodology used for studying the biopharmaceutics of nanoparticles. This review addresses the future potential and safety concerns and genotoxicity of nanoparticle formulations in general. It particularly emphasizes the effects of nanoparticles on metabolic enzymes as well as the parenteral or inhalation administration routes of nanoparticle formulations. This paper illustrates the potential of nanomedicine by discussing biopharmaceutics of fullerene derivatives and their suitability for diagnostic and therapeutic purposes. Future direction is discussed as well. PMID:18855608
Ozone Response to Aircraft Emissions: Sensitivity Studies with Two-dimensional Models
NASA Technical Reports Server (NTRS)
Ko, Malcolm K. W.; Weisenstein, Debra; Jackman, Charles H.; Douglass, Anne R.; Bureske, K.; Weubbles, Donald J.; Kinnison, Douglas E.; Brasseur, G.; Pyle, J.; Jones, Anna
1992-01-01
Our first intercomparison/assessment of the effects of a proposed high-speed civil transport (HSCT) fleet on the stratosphere is presented. These model calculations should be considered more as sensitivity studies, primarily designed to serve the following purposes: (1) to allow for intercomparison of model predictions; (2) to focus on the range of fleet operations and engine specifications giving minimal environmental impact; and (3) to provide the basis for future assessment studies. The basic scenarios were chosen to be as realistic as possible, using the information available on anticipated developments in technology. They are not to be interpreted as a commitment or goal for environmental acceptability.
Managing geometric information with a data base management system
NASA Technical Reports Server (NTRS)
Dube, R. P.
1984-01-01
The strategies for managing computer based geometry are described. The computer model of geometry is the basis for communication, manipulation, and analysis of shape information. The research on integrated programs for aerospace-vehicle design (IPAD) focuses on the use of data base management system (DBMS) technology to manage engineering/manufacturing data. The objectives of IPAD is to develop a computer based engineering complex which automates the storage, management, protection, and retrieval of engineering data. In particular, this facility must manage geometry information as well as associated data. The approach taken on the IPAD project to achieve this objective is discussed. Geometry management in current systems and the approach taken in the early IPAD prototypes are examined.
Engine-propeller power plant aircraft community noise reduction key methods
NASA Astrophysics Data System (ADS)
Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.
2018-04-01
Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.
Funke, Todd; Yang, Yan; Han, Huijong; Healy-Fried, Martha; Olesen, Sanne; Becker, Andreas; Schönbrunn, Ernst
2009-01-01
The shikimate pathway enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) is the target of the broad spectrum herbicide glyphosate. The genetic engineering of EPSPS led to the introduction of glyphosate-resistant crops worldwide. The genetically engineered corn lines NK603 and GA21 carry distinct EPSPS enzymes. CP4 EPSPS, expressed in NK603 corn and transgenic soybean, cotton, and canola, belongs to class II EPSPS, glyphosate-insensitive variants of this enzyme isolated from certain Gram-positive bacteria. GA21 corn, on the other hand, was created by point mutations of class I EPSPS, such as the enzymes from Zea mays or Escherichia coli, which are sensitive to low glyphosate concentrations. The structural basis of the glyphosate resistance resulting from these point mutations has remained obscure. We studied the kinetic and structural effects of the T97I/P101S double mutation, the molecular basis for GA21 corn, using EPSPS from E. coli. The T97I/P101S enzyme is essentially insensitive to glyphosate (Ki = 2.4 mm) but maintains high affinity for the substrate phosphoenolpyruvate (PEP) (Km = 0.1 mm). The crystal structure at 1.7-Å resolution revealed that the dual mutation causes a shift of residue Gly96 toward the glyphosate binding site, impairing efficient binding of glyphosate, while the side chain of Ile97 points away from the substrate binding site, facilitating PEP utilization. The single site T97I mutation renders the enzyme sensitive to glyphosate and causes a substantial decrease in the affinity for PEP. Thus, only the concomitant mutations of Thr97 and Pro101 induce the conformational changes necessary to produce catalytically efficient, glyphosate-resistant class I EPSPS. PMID:19211556
Funke, Todd; Yang, Yan; Han, Huijong; Healy-Fried, Martha; Olesen, Sanne; Becker, Andreas; Schönbrunn, Ernst
2009-04-10
The shikimate pathway enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) is the target of the broad spectrum herbicide glyphosate. The genetic engineering of EPSPS led to the introduction of glyphosate-resistant crops worldwide. The genetically engineered corn lines NK603 and GA21 carry distinct EPSPS enzymes. CP4 EPSPS, expressed in NK603 corn and transgenic soybean, cotton, and canola, belongs to class II EPSPS, glyphosate-insensitive variants of this enzyme isolated from certain Gram-positive bacteria. GA21 corn, on the other hand, was created by point mutations of class I EPSPS, such as the enzymes from Zea mays or Escherichia coli, which are sensitive to low glyphosate concentrations. The structural basis of the glyphosate resistance resulting from these point mutations has remained obscure. We studied the kinetic and structural effects of the T97I/P101S double mutation, the molecular basis for GA21 corn, using EPSPS from E. coli. The T97I/P101S enzyme is essentially insensitive to glyphosate (K(i) = 2.4 mm) but maintains high affinity for the substrate phosphoenolpyruvate (PEP) (K(m) = 0.1 mm). The crystal structure at 1.7-A resolution revealed that the dual mutation causes a shift of residue Gly(96) toward the glyphosate binding site, impairing efficient binding of glyphosate, while the side chain of Ile(97) points away from the substrate binding site, facilitating PEP utilization. The single site T97I mutation renders the enzyme sensitive to glyphosate and causes a substantial decrease in the affinity for PEP. Thus, only the concomitant mutations of Thr(97) and Pro(101) induce the conformational changes necessary to produce catalytically efficient, glyphosate-resistant class I EPSPS.
Spectral/ hp element methods: Recent developments, applications, and perspectives
NASA Astrophysics Data System (ADS)
Xu, Hui; Cantwell, Chris D.; Monteserin, Carlos; Eskilsson, Claes; Engsig-Karup, Allan P.; Sherwin, Spencer J.
2018-02-01
The spectral/ hp element method combines the geometric flexibility of the classical h-type finite element technique with the desirable numerical properties of spectral methods, employing high-degree piecewise polynomial basis functions on coarse finite element-type meshes. The spatial approximation is based upon orthogonal polynomials, such as Legendre or Chebychev polynomials, modified to accommodate a C 0 - continuous expansion. Computationally and theoretically, by increasing the polynomial order p, high-precision solutions and fast convergence can be obtained and, in particular, under certain regularity assumptions an exponential reduction in approximation error between numerical and exact solutions can be achieved. This method has now been applied in many simulation studies of both fundamental and practical engineering flows. This paper briefly describes the formulation of the spectral/ hp element method and provides an overview of its application to computational fluid dynamics. In particular, it focuses on the use of the spectral/ hp element method in transitional flows and ocean engineering. Finally, some of the major challenges to be overcome in order to use the spectral/ hp element method in more complex science and engineering applications are discussed.
Defining the Ecological Coefficient of Performance for an Aircraft Propulsion System
NASA Astrophysics Data System (ADS)
Şöhret, Yasin
2018-05-01
The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.
A study of ingestion and dispersion of engine exhaust products in trailing vortex systems
NASA Technical Reports Server (NTRS)
Nielsen, J. N.; Stahara, S. S.; Woolley, J. P.
1973-01-01
Analysis has been made of the ingestion and dispersion of engine exhaust products into the trailing vortex system of supersonic aircraft flying in the stratosphere. The rate of mixing between the supersonic jet and the co-flowing supersonic stream was found to be an order of magnitude less than would be expected on the basis of subsonic eddy-viscosity results. The length of the potential core was 66 nozzle exit radii so that the exhaust gases remain at elevated temperatures and concentrations over much longer distances than previsously estimated. Ingestion started at the end of the potential core and all hot gas from the engine was ingested into the trailing vortex within two core lengths. Comparison between the buoyancy calculations for the supersonic case with nondimensionalized subsonic aircraft contrail data on wake spreading showed good agreement. Velocity and temperature profiles have been specified at various stages of the wake, and the analysis in this report can be used to predict variations of concentrations of species such as nitrogen oxides under conditions of chemical reaction.
Optical limiting in suspension of detonation nanodiamonds in engine oil
NASA Astrophysics Data System (ADS)
Mikheev, Konstantin G.; Krivenkov, Roman Yu.; Mogileva, Tatyana N.; Puzyr, Alexey P.; Bondar, Vladimir S.; Bulatov, Denis L.; Mikheev, Gennady M.
2017-07-01
The optical limiting (OL) of detonation nanodiamond (DND) suspensions in engine oil was studied at a temperature range of 20°C to 100°C. Oil suspensions were prepared on the basis of the DNDs with an average nanoparticle cluster size in hydrosols (Daver) of 50 and 110 nm. Raman spectroscopy was used to characterize the samples. The OL investigation was carried out by the z-scan technique. The fundamental (1064 nm) and second (532 nm) harmonic radiations of YAG:Nd3+ laser with passive Q-switching as an excitation source were used. The OL thresholds for both suspensions at 532 and 1064 nm were determined. It is shown that a decrease in the average nanoparticle cluster size as well as an increase of the wavelength of the incident radiation leads to the OL threshold increase. It is established that the OL performance is not influenced by increasing the temperature from 20°C to 100°C. The results obtained show the possibility of using the DNDs suspensions in engine oil as an optical limiter in a wide temperature range.
Zymomonas mobilis: a novel platform for future biorefineries.
He, Ming Xiong; Wu, Bo; Qin, Han; Ruan, Zhi Yong; Tan, Fu Rong; Wang, Jing Li; Shui, Zong Xia; Dai, Li Chun; Zhu, Qi Li; Pan, Ke; Tang, Xiao Yu; Wang, Wen Guo; Hu, Qi Chun
2014-01-01
Biosynthesis of liquid fuels and biomass-based building block chemicals from microorganisms have been regarded as a competitive alternative route to traditional. Zymomonas mobilis possesses a number of desirable characteristics for its special Entner-Doudoroff pathway, which makes it an ideal platform for both metabolic engineering and commercial-scale production of desirable bio-products as the same as Escherichia coli and Saccharomyces cerevisiae based on consideration of future biomass biorefinery. Z. mobilis has been studied extensively on both fundamental and applied level, which will provide a basis for industrial biotechnology in the future. Furthermore, metabolic engineering of Z. mobilis for enhancing bio-ethanol production from biomass resources has been significantly promoted by different methods (i.e. mutagenesis, adaptive laboratory evolution, specific gene knock-out, and metabolic engineering). In addition, the feasibility of representative metabolites, i.e. sorbitol, bionic acid, levan, succinic acid, isobutanol, and isobutanol produced by Z. mobilis and the strategies for strain improvements are also discussed or highlighted in this paper. Moreover, this review will present some guidelines for future developments in the bio-based chemical production using Z. mobilis as a novel industrial platform for future biofineries.
Ultrafine particle air pollution inside diesel-propelled passenger trains.
Abramesko, Victoria; Tartakovsky, Leonid
2017-07-01
Locomotives with diesel engines are used worldwide and are an important source of air pollution. Pollutant emissions by locomotive engines affect the air quality inside passenger trains. This study is aimed at investigating ultrafine particle (UFP) air pollution inside passenger trains and providing a basis for assessing passenger exposure to this pollutant. The concentrations of UFPs inside the carriages of push-pull trains are dramatically higher when the train operates in pull mode. This clearly shows that locomotive engine emissions are a dominant factor in train passengers' exposure to UFPs. The highest levels of UFP air pollution are observed inside the carriages of pull trains close to the locomotive. In push mode, the UFP number concentrations were lower by factors of 2.6-43 (depending on the carriage type) compared to pull mode. The UFP concentrations are substantially lower in diesel multiple-unit trains than in trains operating in pull mode. A significant influence of the train movement regime on the UFP NC inside a carriage is observed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Design and characterization of a biodegradable composite scaffold for ligament tissue engineering.
Hayami, James W S; Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G
2010-03-15
Herein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan-water matrix of the ligament. The composite scaffold was constructed from cell-adherent, base-etched, electrospun poly(epsilon-caprolactone-co-D,L-lactide) (PCLDLLA) fibers embedded in a noncell-adherent photocrosslinked N-methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 +/- 4%) during the 4-week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. (c) 2009 Wiley Periodicals, Inc.
NASA Technical Reports Server (NTRS)
Gleason, C. C.; Bahr, D. W.
1979-01-01
A double annular advanced technology combustor with low pollutant emission levels was evaluated in a series of CF6-50 engine tests. Engine lightoff was readily obtained and no difficulties were encountered with combustor staging. Engine acceleration and deceleration were smooth, responsive and essentially the same as those obtainable with the CF6-50 combustor. The emission reductions obtained in carbon monoxide, hydrocarbons, and nitrogen oxide levels were 55, 95, and 30 percent, respectively, at an idle power setting of 3.3 percent of takeoff power on an EPA parameter basis. Acceptable smoke levels were also obtained. The exit temperature distribution of the combustor was found to be its major performance deficiency. In all other important combustion system performance aspects, the combustor was found to be generally satisfactory.
Therapeutic genome engineering via CRISPR-Cas systems.
Moreno, Ana M; Mali, Prashant
2017-07-01
Differences in genomes underlie most organismal diversity, and aberrations in genomes underlie many disease states. With the growing knowledge of the genetic and pathogenic basis of human disease, development of safe and efficient platforms for genome and epigenome engineering will transform our ability to therapeutically target human diseases and also potentially engineer disease resistance. In this regard, the recent advent of clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) RNA-guided nuclease systems have transformed our ability to target nucleic acids. Here we review therapeutic genome engineering applications with a specific focus on the CRISPR-Cas toolsets. We summarize past and current work, and also outline key challenges and future directions. WIREs Syst Biol Med 2017, 9:e1380. doi: 10.1002/wsbm.1380 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.
In-flight thrust determination on a real-time basis
NASA Technical Reports Server (NTRS)
Ray, R. J.; Carpenter, T.; Sandlin, T.
1984-01-01
A real time computer program was implemented on a F-15 jet fighter to monitor in-flight engine performance of a Digital Electronic Engine Controlled (DEES) F-100 engine. The application of two gas generator methods to calculate in-flight thrust real time is described. A comparison was made between the actual results and those predicted by an engine model simulation. The percent difference between the two methods was compared to the predicted uncertainty based on instrumentation and model uncertainty and agreed closely with the results found during altitude facility testing. Data was obtained from acceleration runs of various altitudes at maximum power settings with and without afterburner. Real time in-flight thrust measurement was a major advancement to flight test productivity and was accomplished with no loss in accuracy over previous post flight methods.
X-33 Combustion-Wave Ignition System Tested
NASA Technical Reports Server (NTRS)
Liou, Larry C.
1999-01-01
The NASA Lewis Research Center, in cooperation with Rocketdyne, the Boeing Company, tested a novel rocket engine ignition system, called the combustion-wave ignition system, in its Research Combustion Laboratory. This ignition system greatly simplifies ignition in rocket engines that have a large number of combustors. The particular system tested was designed and fabricated by Rocketdyne for the national experimental spacecraft, X-33, which uses Rocketdyne s aerospike rocket engines. The goal of the tests was to verify the system design and define its operational characteristics. Results will contribute to the eventual successful flight of X-33. Furthermore, the combustion-wave ignition system, after it is better understood and refined on the basis of the test results and, later, flight-proven onboard X-33, could become an important candidate engine ignition system for our Nation s next-generation reusable launch vehicle.
Experimental analysis of IMEP in a rotary combustion engine. [Indicated Mean Effective Pressure
NASA Technical Reports Server (NTRS)
Schock, H. J.; Rice, W. J.; Meng, P. R.
1981-01-01
This experimental work demonstrates the use of a NASA designed, real time Indicated Mean Effective Pressure (IMEP) measurement system which will be used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate the volume function in real time. Measurements at two engine speeds (2000 and 3000 RPM) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 RPM.
Structure, function, and engineering of enzymes in isoflavonoid biosynthesis.
Wang, Xiaoqiang
2011-03-01
Isoflavonoids are a large group of plant natural products and play important roles in plant defense. They also possess valuable health-promoting activities with significant health benefits for animals and humans. The isoflavonoids are identified primarily in leguminous plants and are synthesized through the central phenylpropanoid pathway and the specific isoflavonoid branch pathways in legumes. Structural studies of some key enzymes in the central phenylpropanoid pathway shed light on the early stages of the (iso)flavonoid biosynthetic process. Significant impact has also been made on structural studies of enzymes in the isoflavonoid branch pathways. Structures of isoflavonoid-specific NADPH-dependent reductases revealed how the (iso)flavonoid backbones are modified by reduction reactions and how enzymes specifically recognize isoflavonoids and catalyze stereo-specific reductions. Structural studies of isoflavonoid methyltransferases and glycosyltransferases revealed how isoflavonoids are further decorated with methyl group and sugars in different methylation and glycosylation patterns that determine their bioactivities and functions. In combination with mutagenesis and biochemical studies, the detailed structural information of these enzymes provides a basis for understanding the complex biosynthetic process, enzyme catalytic mechanisms, and substrate specificities. Structure-based homology modeling facilitates the functional characterization of these large groups of biosynthetic enzymes and their homologs. Structure-based enzyme engineering is becoming a new strategy for synthesis of bioactive isoflavonoids and also facilitates plant metabolic engineering towards improvement of quality and production of crop plants.
NASA Astrophysics Data System (ADS)
Leu, Jun-Der; Lee, Larry Jung-Hsing
2017-09-01
Enterprise resource planning (ERP) is a software solution that integrates the operational processes of the business functions of an enterprise. However, implementing ERP systems is a complex process. In addition to the technical issues, companies must address problems associated with business process re-engineering, time and budget control, and organisational change. Numerous industrial studies have shown that the failure rate of ERP implementation is high, even for well-designed systems. Thus, ERP projects typically require a clear methodology to support the project execution and effectiveness. In this study, we propose a theoretical model for ERP implementation. The value engineering (VE) method forms the basis of the proposed framework, which integrates Six Sigma tools. The proposed framework encompasses five phases: knowledge generation, analysis, creation, development and execution. In the VE method, potential ERP problems related to software, hardware, consultation and organisation are analysed in a group-decision manner and in relation to value, and Six Sigma tools are applied to avoid any project defects. We validate the feasibility of the proposed model by applying it to an international manufacturing enterprise in Taiwan. The results show improvements in customer response time and operational efficiency in terms of work-in-process and turnover of materials. Based on the evidence from the case study, the theoretical framework is discussed together with the study's limitations and suggestions for future research.
Models for predicting the mass of lime fruits by some engineering properties.
Miraei Ashtiani, Seyed-Hassan; Baradaran Motie, Jalal; Emadi, Bagher; Aghkhani, Mohammad-Hosein
2014-11-01
Grading fruits based on mass is important in packaging and reduces the waste, also increases the marketing value of agricultural produce. The aim of this study was mass modeling of two major cultivars of Iranian limes based on engineering attributes. Models were classified into three: 1-Single and multiple variable regressions of lime mass and dimensional characteristics. 2-Single and multiple variable regressions of lime mass and projected areas. 3-Single regression of lime mass based on its actual volume and calculated volume assumed as ellipsoid and prolate spheroid shapes. All properties considered in the current study were found to be statistically significant (ρ < 0.01). The results indicated that mass modeling of lime based on minor diameter and first projected area are the most appropriate models in the first and the second classifications, respectively. In third classification, the best model was obtained on the basis of the prolate spheroid volume. It was finally concluded that the suitable grading system of lime mass is based on prolate spheroid volume.
Engine-Operating Load Influences Diesel Exhaust Composition and Cardiopulmonary and Immune Responses
Campen, Matthew J.; Harrod, Kevin S.; Seagrave, JeanClare; Seilkop, Steven K.; Mauderly, Joe L.
2011-01-01
Background: The composition of diesel engine exhaust (DEE) varies by engine type and condition, fuel, engine operation, and exhaust after treatment such as particle traps. DEE has been shown to increase inflammation, susceptibility to infection, and cardiovascular responses in experimentally exposed rodents and humans. Engines used in these studies have been operated at idle, at different steady-state loads, or on variable-load cycles, but exposures are often reported only as the mass concentration of particulate matter (PM), and the effects of different engine loads and the resulting differences in DEE composition are unknown. Objectives: We assessed the impacts of load-related differences in DEE composition on models of inflammation, susceptibility to infection, and cardiovascular toxicity. Methods: We assessed inflammation and susceptibility to viral infection in C57BL/6 mice and cardiovascular toxicity in APOE–/– mice after being exposed to DEE generated from a single-cylinder diesel generator operated at partial or full load. Results: At the same PM mass concentration, partial load resulted in higher proportions of particle organic carbon content and a smaller particle size than did high load. Vapor-phase hydrocarbon content was greater at partial load. Compared with high-load DEE, partial-load DEE caused greater responses in heart rate and T-wave morphology, in terms of both magnitude and rapidity of onset of effects, consistent with previous findings that systemic effects may be driven largely by the gas phase of the exposure atmospheres. However, high-load DEE caused more lung inflammation and greater susceptibility to viral infection than did partial load. Conclusions: Differences in engine load, as well as other operating variables, are important determinants of the type and magnitude of responses to inhaled DEE. PM mass concentration alone is not a sufficient basis for comparing or combining results from studies using DEE generated under different conditions. PMID:21524982
A Student's Candid Reactions to Recruiters
ERIC Educational Resources Information Center
Velcamp, John T.
1970-01-01
Actual records of a chemical engineering major present a number of interviews held with assorted companies. His comments suggest that while initially he sought status, location and challenge, he became more interested in the personal touch," and selected his employer on that basis. (CJ)
A Generic Structural Integrity Assurance Technology Program for the Army
1989-11-01
and Pressure Vessel Code , American Society of Mechanical Engineers, 1986. DEFINITIONS AND ACRONYMS Definitions A-Basis: At least 99 percent of the...Aluminum Bridge and Other Highway Structures, 1976. Aluminum Association Specifications for Aluminum Structures, Third Edition, 1976. ASME ASME Boiler
Reasoning with Geometric Shapes
ERIC Educational Resources Information Center
Seah, Rebecca
2015-01-01
Geometry belongs to branches of mathematics that develop students' visualisation, intuition, critical thinking, problem solving, deductive reasoning, logical argument and proof (Jones, 2002). It provides the basis for the development of spatial sense and plays an important role in acquiring advanced knowledge in science, technology, engineering,…
Vehicle fires and fire safety in tunnels
DOT National Transportation Integrated Search
2002-09-20
Tunnels present what is arguably the most hazardous environment, from the point of view of fire safety, that members of the public ever experience. The fire safety design of tunnels is carried out by tunnel engineers on the basis of a potential fire ...
Weibull-Based Design Methodology for Rotating Aircraft Engine Structures
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry
2002-01-01
The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-06-01
This Technical Memorandum, was developed under Work Breakdown Structure 1.4.12.6.1.01.41.12.02. 11 (Activity Data Sheet 3301, ``WAG 1``). This document provides the Environmental Restoration Program with analytical results from liquid and sludge samples from the Gunite and Associated Tanks (GAAT). Information provided in this report forms part of the technical basis for criticality safety, systems safety, engineering design, and waste management as they apply to the GAAT treatability study and remediation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
FINNEY, Charles E A; Edwards, Kevin Dean; Stoyanov, Miroslav K
2015-01-01
Combustion instabilities in dilute internal combustion engines are manifest in cyclic variability (CV) in engine performance measures such as integrated heat release or shaft work. Understanding the factors leading to CV is important in model-based control, especially with high dilution where experimental studies have demonstrated that deterministic effects can become more prominent. Observation of enough consecutive engine cycles for significant statistical analysis is standard in experimental studies but is largely wanting in numerical simulations because of the computational time required to compute hundreds or thousands of consecutive cycles. We have proposed and begun implementation of an alternative approach to allowmore » rapid simulation of long series of engine dynamics based on a low-dimensional mapping of ensembles of single-cycle simulations which map input parameters to output engine performance. This paper details the use Titan at the Oak Ridge Leadership Computing Facility to investigate CV in a gasoline direct-injected spark-ignited engine with a moderately high rate of dilution achieved through external exhaust gas recirculation. The CONVERGE CFD software was used to perform single-cycle simulations with imposed variations of operating parameters and boundary conditions selected according to a sparse grid sampling of the parameter space. Using an uncertainty quantification technique, the sampling scheme is chosen similar to a design of experiments grid but uses functions designed to minimize the number of samples required to achieve a desired degree of accuracy. The simulations map input parameters to output metrics of engine performance for a single cycle, and by mapping over a large parameter space, results can be interpolated from within that space. This interpolation scheme forms the basis for a low-dimensional metamodel which can be used to mimic the dynamical behavior of corresponding high-dimensional simulations. Simulations of high-EGR spark-ignition combustion cycles within a parametric sampling grid were performed and analyzed statistically, and sensitivities of the physical factors leading to high CV are presented. With these results, the prospect of producing low-dimensional metamodels to describe engine dynamics at any point in the parameter space will be discussed. Additionally, modifications to the methodology to account for nondeterministic effects in the numerical solution environment are proposed« less
Mathematical interpretation of Brownian motor model: Limit cycles and directed transport phenomena
NASA Astrophysics Data System (ADS)
Yang, Jianqiang; Ma, Hong; Zhong, Suchuang
2018-03-01
In this article, we first suggest that the attractor of Brownian motor model is one of the reasons for the directed transport phenomenon of Brownian particle. We take the classical Smoluchowski-Feynman (SF) ratchet model as an example to investigate the relationship between limit cycles and directed transport phenomenon of the Brownian particle. We study the existence and variation rule of limit cycles of SF ratchet model at changing parameters through mathematical methods. The influences of these parameters on the directed transport phenomenon of a Brownian particle are then analyzed through numerical simulations. Reasonable mathematical explanations for the directed transport phenomenon of Brownian particle in SF ratchet model are also formulated on the basis of the existence and variation rule of the limit cycles and numerical simulations. These mathematical explanations provide a theoretical basis for applying these theories in physics, biology, chemistry, and engineering.
Disorder enabled band structure engineering of a topological insulator surface
Xu, Yishuai; Chiu, Janet; Miao, Lin; ...
2017-02-03
Three-dimensional topological insulators are bulk insulators with Z 2 topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by non-magnetic disorder, and have been adopted as the basis for a wide range of proposals to achieve new quasiparticle species and device functionality. Recent studies have yielded a surprise by showing that in spite of resisting localization, topological insulator surface electrons can be reshaped by defects into distinctive resonance states. Here we use numerical simulations and scanning tunnelling microscopy data to show that these resonance states have significance well beyond themore » localized regime usually associated with impurity bands. Lastly, at native densities in the model Bi 2X 3 (X=Bi, Te) compounds, defect resonance states are predicted to generate a new quantum basis for an emergent electron gas that supports diffusive electrical transport.« less
Treatability studies performed in support of an engineering evaluation/cost analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Myers, J.M.; Mueller, J.P.; Sundquist, J.A.
1995-12-31
The Southern Shipbuilding Corporation (SSC) site is located on 54 acres of wooded land adjacent to Bayou Bonfouca, approximately 1.8 miles downstream of the Bayou Bonfouca National Priorities List (NPL) Superfund site in Slidell, St. Tammany Parish, Louisiana. Two one-acre, impoundments on the SSC site were used to store wastes generated from vessel cleaning. Wastes stored in the impoundments are migrating into Bayou Bonfouca, which empties into Lake Pontchartrain. In addition, the impoundments are frequently invaded by flood waters. The US EPA Emergency Response Branch (EPA-ERB) performed a site investigation which indicated that the majority of the contamination is petroleum-relatedmore » and that the compounds of concern are polycyclic aromatic hydrocarbons (PARs). The wastes are generally contained with the two impoundments and surrounding soils. As part of an Engineering Evaluation/Cost Basis (EE/CA) of potential response action alternatives, four treatability studies were performed. A thermal treatment (incineration) study was performed at the EPA`s Incineration Research Facility (IRF). Biodegradation remedy selection feasibility assessment was conducted on-site. A remedy screening soil washing study was also performed by TAT. A solidification/stabilization (S/S) study was conducted through EPA`s Risk Reduction Engineering Laboratory (RREL) to ascertain if the PAHs could be immobilized within a solid matrix. Experimental objectives, dead methodology and conclusions for these studies are presented as they relate to potential response actions being evaluated at the SSC site.« less
NASA Technical Reports Server (NTRS)
Santi, Louis M.; Butas, John P.; Aguilar, Robert B.; Sowers, Thomas S.
2008-01-01
The J-2X is an expendable liquid hydrogen (LH2)/liquid oxygen (LOX) gas generator cycle rocket engine that is currently being designed as the primary upper stage propulsion element for the new NASA Ares vehicle family. The J-2X engine will contain abort logic that functions as an integral component of the Ares vehicle abort system. This system is responsible for detecting and responding to conditions indicative of impending Loss of Mission (LOM), Loss of Vehicle (LOV), and/or catastrophic Loss of Crew (LOC) failure events. As an earth orbit ascent phase engine, the J-2X is a high power density propulsion element with non-negligible risk of fast propagation rate failures that can quickly lead to LOM, LOV, and/or LOC events. Aggressive reliability requirements for manned Ares missions and the risk of fast propagating J-2X failures dictate the need for on-engine abort condition monitoring and autonomous response capability as well as traditional abort agents such as the vehicle computer, flight crew, and ground control not located on the engine. This paper describes the baseline J-2X abort subsystem concept of operations, as well as the development process for this subsystem. A strategy that leverages heritage system experience and responds to an evolving engine design as well as J-2X specific test data to support abort system development is described. The utilization of performance and failure simulation models to support abort system sensor selection, failure detectability and discrimination studies, decision threshold definition, and abort system performance verification and validation is outlined. The basis for abort false positive and false negative performance constraints is described. Development challenges associated with information shortfalls in the design cycle, abort condition coverage and response assessment, engine-vehicle interface definition, and abort system performance verification and validation are also discussed.
NASA Astrophysics Data System (ADS)
Futko, S. I.; Koznacheev, I. A.; Ermolaeva, E. M.
2014-11-01
On the basis of thermodynamic calculations, the features of the combustion of a solid-fuel mixture based on the glycidyl azide polymer were investigated, the thermal cycle of the combustion chamber of a model engine system was analyzed, and the efficiency of this chamber was determined for a wide range of pressures in it and different ratios between the components of the combustible mixture. It was established that, when the pressure in the combustion chamber of an engine system increases, two maxima arise successively on the dependence of the thermal efficiency of the chamber on the weight fractions of the components of the combustible mixture and that the first maximum shifts to the side of smaller concentrations of the glycidyl azide polymer with increase in the pressure in the chamber; the position of the second maximum is independent of this pressure, coincides with the minimum on the dependence of the rate of combustion of the mixture, and corresponds to the point of its structural phase transition at which the mole fractions of the carbon and oxygen atoms in the mixture are equal. The results obtained were interpreted on the basis of the Le-Chatelier principle.
The role of continuity in residual-based variational multiscale modeling of turbulence
NASA Astrophysics Data System (ADS)
Akkerman, I.; Bazilevs, Y.; Calo, V. M.; Hughes, T. J. R.; Hulshoff, S.
2008-02-01
This paper examines the role of continuity of the basis in the computation of turbulent flows. We compare standard finite elements and non-uniform rational B-splines (NURBS) discretizations that are employed in Isogeometric Analysis (Hughes et al. in Comput Methods Appl Mech Eng, 194:4135 4195, 2005). We make use of quadratic discretizations that are C 0-continuous across element boundaries in standard finite elements, and C 1-continuous in the case of NURBS. The variational multiscale residual-based method (Bazilevs in Isogeometric analysis of turbulence and fluid-structure interaction, PhD thesis, ICES, UT Austin, 2006; Bazilevs et al. in Comput Methods Appl Mech Eng, submitted, 2007; Calo in Residual-based multiscale turbulence modeling: finite volume simulation of bypass transition. PhD thesis, Department of Civil and Environmental Engineering, Stanford University, 2004; Hughes et al. in proceedings of the XXI international congress of theoretical and applied mechanics (IUTAM), Kluwer, 2004; Scovazzi in Multiscale methods in science and engineering, PhD thesis, Department of Mechanical Engineering, Stanford Universty, 2004) is employed as a turbulence modeling technique. We find that C 1-continuous discretizations outperform their C 0-continuous counterparts on a per-degree-of-freedom basis. We also find that the effect of continuity is greater for higher Reynolds number flows.
Compression-ignition engine tests of several fuels
NASA Technical Reports Server (NTRS)
Spanogle, J A
1932-01-01
The tests reported in this paper were made to devise simple engine tests which would rate fuels as to their comparative value and their suitability for the operating conditions of the individual engine on which the tests are made. Three commercial fuels were used in two test engines having combustion chambers with and without effective air flow. Strictly comparative performance tests gave almost identical results for the three fuels. Analysis of indicator cards allowed a differentiation between fuels on a basis of rates of combustion. The same comparative ratings were obtained by determining the consistent operating range of injection advance angle for the three fuels. The difference in fuels is more pronounced in a quiescent combustion chamber than in one with high-velocity air flow. A fuel is considered suitable for the operating conditions of an engine with a quiescent combustion chamber if it permits the injection of the fuel to be advanced beyond the optimum without exceeding allowable knock or allowable maximum cylinder pressures.
Currently available medical engineering degrees in the UK. Part 2: Postgraduate degrees.
Joyce, T
2009-05-01
This paper considers taught medical engineering MSc degrees, based on mechanical engineering, which are provided in the UK. Currently there are 19 institutions which provide such postgraduate degree programmes. These are the University of Aberdeen, University of Bath, University of Bradford, Brunel University, University of Dundee, University of Hull, Imperial College London, Keele University, King's College London, University of Leeds, University of Liverpool, University of Nottingham, University of Oxford, Queen Mary University of London, University of Southampton, University of Strathclyde, University of Surrey, University of Ulster, and University of Warwick. While most courses are delivered on a 1 year full-time basis, other delivery modes are also available. Relatively few modules are offered as distance learning or short courses. A wide range of modules are offered by the various universities for the different taught MSc degrees. Common modules include biomaterials and biomechanics. The medical-engineering-related modules offered by a number of universities are also made available to students on allied MSc programmes and undergraduate degrees in medical engineering.
Means of storage and automated monitoring of versions of text technical documentation
NASA Astrophysics Data System (ADS)
Leonovets, S. A.; Shukalov, A. V.; Zharinov, I. O.
2018-03-01
The paper presents automation of the process of preparation, storage and monitoring of version control of a text designer, and program documentation by means of the specialized software is considered. Automation of preparation of documentation is based on processing of the engineering data which are contained in the specifications and technical documentation or in the specification. Data handling assumes existence of strictly structured electronic documents prepared in widespread formats according to templates on the basis of industry standards and generation by an automated method of the program or designer text document. Further life cycle of the document and engineering data entering it are controlled. At each stage of life cycle, archive data storage is carried out. Studies of high-speed performance of use of different widespread document formats in case of automated monitoring and storage are given. The new developed software and the work benches available to the developer of the instrumental equipment are described.
An engineering analysis of a closed cycle plant growth module
NASA Technical Reports Server (NTRS)
Stickford, G. H., Jr.; Jakob, F. E.; Landstrom, D. K.
1986-01-01
The SOLGEM model is a numerical engineering model which solves the flow and energy balance equations for the air flowing through a growing environment, assuming quasi-steady state conditions within the system. SOLGEM provides a dynamic simulation of the controlled environment system in that the temperature and flow conditions of the growing environment are estimated on an hourly basis in response to the weather data and the plant growth parameters. The flow energy balance considers the incident solar flux; incoming air temperature, humidity, and flow rate; heat exchange with the roof and floor; and heat and moisture exchange with the plants. A plant transpiration subroutine was developed based plant growth research facility, intended for the study of bioregenerative life support theories. The results of a performance analysis of the plant growth module are given. The estimated energy requirements of the module components and the total energy are given.