Network Analysis of Conversation Data for Engineering Professional Skills Assessment. Research Report. ETS RR-17-59

ERIC Educational Resources Information Center

Zhu, Mengxiao; Zhang, Mo

2017-01-01

In this paper, we examine the student group discussion processes in a scenario-based assessment of engineering professional skills called Engineering Professional Skills Assessment (EPSA). In the assessment, the students were evaluated through a discussion on a scenario related to an engineering problem with no clear-cut solution. We applied…

Enterprise 3.0 in Engineering Education

ERIC Educational Resources Information Center

Ahrens, Andreas; Zascerinska, Jelena

2011-01-01

Enterprise 3.0 offers potential solutions for the quality, maintenance and sustainable development of services. The synergy between Enterprise 3.0 and engineering education advances the development of innovative products, processes and services in the European economy. Aim of the research is to analyze student engineers' use of Enterprise 3.0…

Lessons Learned During Solutions of Multidisciplinary Design Optimization Problems

NASA Technical Reports Server (NTRS)

Patnaik, Suna N.; Coroneos, Rula M.; Hopkins, Dale A.; Lavelle, Thomas M.

2000-01-01

Optimization research at NASA Glenn Research Center has addressed the design of structures, aircraft and airbreathing propulsion engines. During solution of the multidisciplinary problems several issues were encountered. This paper lists four issues and discusses the strategies adapted for their resolution: (1) The optimization process can lead to an inefficient local solution. This deficiency was encountered during design of an engine component. The limitation was overcome through an augmentation of animation into optimization. (2) Optimum solutions obtained were infeasible for aircraft and air-breathing propulsion engine problems. Alleviation of this deficiency required a cascading of multiple algorithms. (3) Profile optimization of a beam produced an irregular shape. Engineering intuition restored the regular shape for the beam. (4) The solution obtained for a cylindrical shell by a subproblem strategy converged to a design that can be difficult to manufacture. Resolution of this issue remains a challenge. The issues and resolutions are illustrated through six problems: (1) design of an engine component, (2) synthesis of a subsonic aircraft, (3) operation optimization of a supersonic engine, (4) design of a wave-rotor-topping device, (5) profile optimization of a cantilever beam, and (6) design of a cvlindrical shell. The combined effort of designers and researchers can bring the optimization method from academia to industry.

Methods of the working processes modelling of an internal combustion engine by an ANSYS IC Engine module

NASA Astrophysics Data System (ADS)

Kurchatkin, I. V.; Gorshkalev, A. A.; Blagin, E. V.

2017-01-01

This article deals with developed methods of the working processes modelling in the combustion chamber of an internal combustion engine (ICE). Methods includes description of the preparation of a combustion chamber 3-d model, setting of the finite-element mesh, boundary condition setting and solution customization. Aircraft radial engine M-14 was selected for modelling. The cycle of cold blowdown in the ANSYS IC Engine software was carried out. The obtained data were compared to results of known calculation methods. A method of engine’s induction port improvement was suggested.

On-line infrared process signature measurements through combustion atmospheres

NASA Astrophysics Data System (ADS)

Zweibaum, F. M.; Kozlowski, A. T.; Surette, W. E., Jr.

1980-01-01

A number of on-line infrared process signature measurements have been made through combustion atmospheres, including those in jet engines, piston engines, and coal gasification reactors. The difficulties involved include operation in the presence of pressure as high as 1800 psi, temperatures as high as 3200 F, and explosive, corrosive and dust-laden atmospheres. Calibration problems have resulted from the use of purge gases to clear the viewing tubes, and the obscuration of the view ports by combustion products. A review of the solutions employed to counteract the problems is presented, and areas in which better solutions are required are suggested.

Engineers and Their Role in Public Policy: An Active Learning Experience for Enhancing the Understanding of the State

ERIC Educational Resources Information Center

Acevedo, Jorge; Barros, Ricardo; Ramirez, Catalina; Realpe, Natalia

2009-01-01

To achieve effective intervention of engineers in the public sector, engineers should develop skills to comprehend their ethical and professional responsibility, and they should gain the necessary education to understand the possible impact of engineering solutions in a global and social context. An active learning process has been conceived,…

Quantitative optical imaging and sensing by joint design of point spread functions and estimation algorithms

NASA Astrophysics Data System (ADS)

Quirin, Sean Albert

The joint application of tailored optical Point Spread Functions (PSF) and estimation methods is an important tool for designing quantitative imaging and sensing solutions. By enhancing the information transfer encoded by the optical waves into an image, matched post-processing algorithms are able to complete tasks with improved performance relative to conventional designs. In this thesis, new engineered PSF solutions with image processing algorithms are introduced and demonstrated for quantitative imaging using information-efficient signal processing tools and/or optical-efficient experimental implementations. The use of a 3D engineered PSF, the Double-Helix (DH-PSF), is applied as one solution for three-dimensional, super-resolution fluorescence microscopy. The DH-PSF is a tailored PSF which was engineered to have enhanced information transfer for the task of localizing point sources in three dimensions. Both an information- and optical-efficient implementation of the DH-PSF microscope are demonstrated here for the first time. This microscope is applied to image single-molecules and micro-tubules located within a biological sample. A joint imaging/axial-ranging modality is demonstrated for application to quantifying sources of extended transverse and axial extent. The proposed implementation has improved optical-efficiency relative to prior designs due to the use of serialized cycling through select engineered PSFs. This system is demonstrated for passive-ranging, extended Depth-of-Field imaging and digital refocusing of random objects under broadband illumination. Although the serialized engineered PSF solution is an improvement over prior designs for the joint imaging/passive-ranging modality, it requires the use of multiple PSFs---a potentially significant constraint. Therefore an alternative design is proposed, the Single-Helix PSF, where only one engineered PSF is necessary and the chromatic behavior of objects under broadband illumination provides the necessary information transfer. The matched estimation algorithms are introduced along with an optically-efficient experimental system to image and passively estimate the distance to a test object. An engineered PSF solution is proposed for improving the sensitivity of optical wave-front sensing using a Shack-Hartmann Wave-front Sensor (SHWFS). The performance limits of the classical SHWFS design are evaluated and the engineered PSF system design is demonstrated to enhance performance. This system is fabricated and the mechanism for additional information transfer is identified.

System catalytic neutralization control of combustion engines waste gases in mining technologies

NASA Astrophysics Data System (ADS)

Korshunov, G. I.; Solnitsev, R. I.

2017-10-01

The paper presents the problems solution of the atmospheric air pollution with the exhaust gases of the internal combustion engines, used in mining technologies. Such engines are used in excavators, bulldozers, dump trucks, diesel locomotives in loading and unloading processes and during transportation of minerals. NOx, CO, CH emissions as the waste gases occur during engine operation, the concentration of which must be reduced to the standard limits. The various methods and means are used for the problem solution, one of which is neutralization based on platinum catalysts. A mathematical model of a controlled catalytic neutralization system is proposed. The simulation results confirm the increase in efficiency at start-up and low engine load and the increase in the catalyst lifetime.

Improving the Simplified Acquisition of Base Engineering Requirements (SABER) Delivery Order Award Process: Results of a Process Improvement Plan

DTIC Science & Technology

1991-09-01

putting all tasks directed towsrds achieving an outcome in aequence. The tasks can be viewed as steps in the process (39:2.3). Using this...improvement opportunity is investigated. A plan is developed, root causes are identified, and solutions are tested and implemented. The process is... solutions , check for actual improvement, and integrate the successful improvements into the process. ?UP 7. Check Improvement Performance. Finally, the

The Future of Pharmaceutical Manufacturing Sciences

PubMed Central

2015-01-01

The entire pharmaceutical sector is in an urgent need of both innovative technological solutions and fundamental scientific work, enabling the production of highly engineered drug products. Commercial‐scale manufacturing of complex drug delivery systems (DDSs) using the existing technologies is challenging. This review covers important elements of manufacturing sciences, beginning with risk management strategies and design of experiments (DoE) techniques. Experimental techniques should, where possible, be supported by computational approaches. With that regard, state‐of‐art mechanistic process modeling techniques are described in detail. Implementation of materials science tools paves the way to molecular‐based processing of future DDSs. A snapshot of some of the existing tools is presented. Additionally, general engineering principles are discussed covering process measurement and process control solutions. Last part of the review addresses future manufacturing solutions, covering continuous processing and, specifically, hot‐melt processing and printing‐based technologies. Finally, challenges related to implementing these technologies as a part of future health care systems are discussed. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3612–3638, 2015 PMID:26280993

The Future of Pharmaceutical Manufacturing Sciences.

PubMed

Rantanen, Jukka; Khinast, Johannes

2015-11-01

The entire pharmaceutical sector is in an urgent need of both innovative technological solutions and fundamental scientific work, enabling the production of highly engineered drug products. Commercial-scale manufacturing of complex drug delivery systems (DDSs) using the existing technologies is challenging. This review covers important elements of manufacturing sciences, beginning with risk management strategies and design of experiments (DoE) techniques. Experimental techniques should, where possible, be supported by computational approaches. With that regard, state-of-art mechanistic process modeling techniques are described in detail. Implementation of materials science tools paves the way to molecular-based processing of future DDSs. A snapshot of some of the existing tools is presented. Additionally, general engineering principles are discussed covering process measurement and process control solutions. Last part of the review addresses future manufacturing solutions, covering continuous processing and, specifically, hot-melt processing and printing-based technologies. Finally, challenges related to implementing these technologies as a part of future health care systems are discussed. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association.

A knowledge-based approach to configuration layout, justification, and documentation

NASA Technical Reports Server (NTRS)

Craig, F. G.; Cutts, D. E.; Fennel, T. R.; Case, C.; Palmer, J. R.

1990-01-01

The design, development, and implementation is described of a prototype expert system which could aid designers and system engineers in the placement of racks aboard modules on Space Station Freedom. This type of problem is relevant to any program with multiple constraints and requirements demanding solutions which minimize usage of limited resources. This process is generally performed by a single, highly experienced engineer who integrates all the diverse mission requirements and limitations, and develops an overall technical solution which meets program and system requirements with minimal cost, weight, volume, power, etc. This system architect performs an intellectual integration process in which the underlying design rationale is often not fully documented. This is a situation which lends itself to an expert system solution for enhanced consistency, thoroughness, documentation, and change assessment capabilities.

A Knowledge-Based Approach to Configuration Layout, Justification, and Documentation

NASA Technical Reports Server (NTRS)

Craig, F. G.; Cutts, D. E.; Fennel, T. R.; Case, C. M.; Palmer, J. R.

1991-01-01

The design, development, and implementation of a prototype expert system which could aid designers and system engineers in the placement of racks aboard modules on the Space Station Freedom are described. This type of problem is relevant to any program with multiple constraints and requirements demanding solutions which minimize usage of limited resources. This process is generally performed by a single, highly experienced engineer who integrates all the diverse mission requirements and limitations, and develops an overall technical solution which meets program and system requirements with minimal cost, weight, volume, power, etc. This system architect performs an intellectual integration process in which the underlying design rationale is often not fully documented. This is a situation which lends itself to an expert system solution for enhanced consistency, thoroughness, documentation, and change assessment capabilities.

Aircraft Flight Modeling During the Optimization of Gas Turbine Engine Working Process

NASA Astrophysics Data System (ADS)

Tkachenko, A. Yu; Kuz'michev, V. S.; Krupenich, I. N.

2018-01-01

The article describes a method for simulating the flight of the aircraft along a predetermined path, establishing a functional connection between the parameters of the working process of gas turbine engine and the efficiency criteria of the aircraft. This connection is necessary for solving the optimization tasks of the conceptual design stage of the engine according to the systems approach. Engine thrust level, in turn, influences the operation of aircraft, thus making accurate simulation of the aircraft behavior during flight necessary for obtaining the correct solution. The described mathematical model of aircraft flight provides the functional connection between the airframe characteristics, working process of gas turbine engines (propulsion system), ambient and flight conditions and flight profile features. This model provides accurate results of flight simulation and the resulting aircraft efficiency criteria, required for optimization of working process and control function of a gas turbine engine.

Engineering Design Thinking and Information Gathering. Final Report. Research in Engineering and Technology Education

ERIC Educational Resources Information Center

Mentzer, Nathan

2011-01-01

The objective of this research was to explore the relationship between information access and design solution quality of high school students presented with an engineering design problem. This objective is encompassed in the research question driving this inquiry: How does information access impact the design process? This question has emerged in…

Computer Design Technology of the Small Thrust Rocket Engines Using CAE / CAD Systems

NASA Astrophysics Data System (ADS)

Ryzhkov, V.; Lapshin, E.

2018-01-01

The paper presents an algorithm for designing liquid small thrust rocket engine, the process of which consists of five aggregated stages with feedback. Three stages of the algorithm provide engineering support for design, and two stages - the actual engine design. A distinctive feature of the proposed approach is a deep study of the main technical solutions at the stage of engineering analysis and interaction with the created knowledge (data) base, which accelerates the process and provides enhanced design quality. The using multifunctional graphic package Siemens NX allows to obtain the final product -rocket engine and a set of design documentation in a fairly short time; the engine design does not require a long experimental development.

Modeling Water Filtration

ERIC Educational Resources Information Center

Parks, Melissa

2014-01-01

Model-eliciting activities (MEAs) are not new to those in engineering or mathematics, but they were new to Melissa Parks. Model-eliciting activities are simulated real-world problems that integrate engineering, mathematical, and scientific thinking as students find solutions for specific scenarios. During this process, students generate solutions…

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions

PubMed Central

DeJong, Jason T.; Soga, Kenichi; Banwart, Steven A.; Whalley, W. Richard; Ginn, Timothy R.; Nelson, Douglas C.; Mortensen, Brina M.; Martinez, Brian C.; Barkouki, Tammer

2011-01-01

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming—these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that ‘soil engineering in vivo’, wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon—effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized. PMID:20829246

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions.

PubMed

DeJong, Jason T; Soga, Kenichi; Banwart, Steven A; Whalley, W Richard; Ginn, Timothy R; Nelson, Douglas C; Mortensen, Brina M; Martinez, Brian C; Barkouki, Tammer

2011-01-06

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming-these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that 'soil engineering in vivo', wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon-effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized.

Computer-Based Mathematics Instructions for Engineering Students

NASA Technical Reports Server (NTRS)

Khan, Mustaq A.; Wall, Curtiss E.

1996-01-01

Almost every engineering course involves mathematics in one form or another. The analytical process of developing mathematical models is very important for engineering students. However, the computational process involved in the solution of some mathematical problems may be very tedious and time consuming. There is a significant amount of mathematical software such as Mathematica, Mathcad, and Maple designed to aid in the solution of these instructional problems. The use of these packages in classroom teaching can greatly enhance understanding, and save time. Integration of computer technology in mathematics classes, without de-emphasizing the traditional analytical aspects of teaching, has proven very successful and is becoming almost essential. Sample computer laboratory modules are developed for presentation in the classroom setting. This is accomplished through the use of overhead projectors linked to graphing calculators and computers. Model problems are carefully selected from different areas.

Excite Kids about Engineering: Design Squad[TM] and Engineer Your Life[TM] Resources Make It Easy

ERIC Educational Resources Information Center

Cheng, Jack

2008-01-01

The author discusses "Design Squad", a television program designed to introduce students to the engineering process. Each episode tells the story of how two teams tackled a particular challenge. A graphic announces each stage (e.g., brainstorm, design, build, test, and redesign) as the teams construct their solutions. These graphics make visual…

An Exploratory Study of Cost Engineering in Axiomatic Design: Creation of the Cost Model Based on an FR-DP Map

NASA Technical Reports Server (NTRS)

Lee, Taesik; Jeziorek, Peter

2004-01-01

Large complex projects cost large sums of money throughout their life cycle for a variety of reasons and causes. For such large programs, the credible estimation of the project cost, a quick assessment of the cost of making changes, and the management of the project budget with effective cost reduction determine the viability of the project. Cost engineering that deals with these issues requires a rigorous method and systematic processes. This paper introduces a logical framework to a&e effective cost engineering. The framework is built upon Axiomatic Design process. The structure in the Axiomatic Design process provides a good foundation to closely tie engineering design and cost information together. The cost framework presented in this paper is a systematic link between the functional domain (FRs), physical domain (DPs), cost domain (CUs), and a task/process-based model. The FR-DP map relates a system s functional requirements to design solutions across all levels and branches of the decomposition hierarchy. DPs are mapped into CUs, which provides a means to estimate the cost of design solutions - DPs - from the cost of the physical entities in the system - CUs. The task/process model describes the iterative process ot-developing each of the CUs, and is used to estimate the cost of CUs. By linking the four domains, this framework provides a superior traceability from requirements to cost information.

Experimental Replication of an Aeroengine Combustion Instability

NASA Technical Reports Server (NTRS)

Cohen, J. M.; Hibshman, J. R.; Proscia, W.; Rosfjord, T. J.; Wake, B. E.; McVey, J. B.; Lovett, J.; Ondas, M.; DeLaat, J.; Breisacher, K.

2000-01-01

Combustion instabilities in gas turbine engines are most frequently encountered during the late phases of engine development, at which point they are difficult and expensive to fix. The ability to replicate an engine-traceable combustion instability in a laboratory-scale experiment offers the opportunity to economically diagnose the problem (to determine the root cause), and to investigate solutions to the problem, such as active control. The development and validation of active combustion instability control requires that the causal dynamic processes be reproduced in experimental test facilities which can be used as a test bed for control system evaluation. This paper discusses the process through which a laboratory-scale experiment was designed to replicate an instability observed in a developmental engine. The scaling process used physically-based analyses to preserve the relevant geometric, acoustic and thermo-fluid features. The process increases the probability that results achieved in the single-nozzle experiment will be scalable to the engine.

Achieving 14.4% Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Thin Film Solar Cell through Interface Engineering.

PubMed

Park, Gi Soon; Chu, Van Ben; Kim, Byoung Woo; Kim, Dong-Wook; Oh, Hyung-Suk; Hwang, Yun Jeong; Min, Byoung Koun

2018-03-28

An optimization of band alignment at the p-n junction interface is realized on alcohol-based solution-processed Cu(In,Ga)(S,Se) 2 (CIGS) thin film solar cells, achieving a power-conversion-efficiency (PCE) of 14.4%. To obtain a CIGS thin film suitable for interface engineering, we designed a novel "3-step chalcogenization process" for Cu 2- x Se-derived grain growth and a double band gap grading structure. Considering S-rich surface of the CIGS thin film, an alternative ternary (Cd,Zn)S buffer layer is adopted to build favorable "spike" type conduction band alignment instead of "cliff" type. Suppression of interface recombination is elucidated by comparing recombination activation energies using a dark J- V- T analysis.

Detox{sup SM} wet oxidation system studies for engineering scale up

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

Robertson, D.T.; Moslander, J.E.; Zigmond, J.A.

1995-12-31

Catalyzed wet oxidation utilizing iron(III) has been shown to have promise for treating many hazardous and mixed wastes. The reaction occurs at the surface of contact between an aqueous iron(III) solution and organic material. Studies with liquid- and vapor-phase organic waste surrogates have established reaction kinetics and the limits of reaction rate based on organic concentration and iron(III) diffusion. Continuing engineering studies have concentrated on reaction vessel agitator and solids feed configurations, an improved bench scale reflux condenser and reflux condenser calculations, sparging of organic compounds from the process condensate water, filtration of solids from the process solution, and flammabilitymore » limits for volatile organic compounds in the headspace of the reaction vessel under the reaction conditions. Detailed engineering design and fabrication of a demonstration unit for treatment of mixed waste is in progress.« less

Examples of finite element mesh generation using SDRC IDEAS

NASA Technical Reports Server (NTRS)

Zapp, John; Volakis, John L.

1990-01-01

IDEAS (Integrated Design Engineering Analysis Software) offers a comprehensive package for mechanical design engineers. Due to its multifaceted capabilities, however, it can be manipulated to serve the needs of electrical engineers, also. IDEAS can be used to perform the following tasks: system modeling, system assembly, kinematics, finite element pre/post processing, finite element solution, system dynamics, drafting, test data analysis, and project relational database.

Assessment of the mechanics of a tissue-engineered rat trachea in an image-processing environment.

PubMed

Silva, Thiago Henrique Gomes da; Pazetti, Rogerio; Aoki, Fabio Gava; Cardoso, Paulo Francisco Guerreiro; Valenga, Marcelo Henrique; Deffune, Elenice; Evaristo, Thaiane; Pêgo-Fernandes, Paulo Manuel; Moriya, Henrique Takachi

2014-07-01

Despite the recent success regarding the transplantation of tissue-engineered airways, the mechanical properties of these grafts are not well understood. Mechanical assessment of a tissue-engineered airway graft before implantation may be used in the future as a predictor of function. The aim of this preliminary work was to develop a noninvasive image-processing environment for the assessment of airway mechanics. Decellularized, recellularized and normal tracheas (groups DECEL, RECEL, and CONTROL, respectively) immersed in Krebs-Henseleit solution were ventilated by a small-animal ventilator connected to a Fleisch pneumotachograph and two pressure transducers (differential and gauge). A camera connected to a stereomicroscope captured images of the pulsation of the trachea before instillation of saline solution and after instillation of Krebs-Henseleit solution, followed by instillation with Krebs-Henseleit with methacholine 0.1 M (protocols A, K and KMCh, respectively). The data were post-processed with computer software and statistical comparisons between groups and protocols were performed. There were statistically significant variations in the image measurements of the medial region of the trachea between the groups (two-way analysis of variance [ANOVA], p<0.01) and of the proximal region between the groups and protocols (two-way ANOVA, p<0.01). The technique developed in this study is an innovative method for performing a mechanical assessment of engineered tracheal grafts that will enable evaluation of the viscoelastic properties of neo-tracheas prior to transplantation.

Professional Ethics of Software Engineers: An Ethical Framework.

PubMed

Lurie, Yotam; Mark, Shlomo

2016-04-01

The purpose of this article is to propose an ethical framework for software engineers that connects software developers' ethical responsibilities directly to their professional standards. The implementation of such an ethical framework can overcome the traditional dichotomy between professional skills and ethical skills, which plagues the engineering professions, by proposing an approach to the fundamental tasks of the practitioner, i.e., software development, in which the professional standards are intrinsically connected to the ethical responsibilities. In so doing, the ethical framework improves the practitioner's professionalism and ethics. We call this approach Ethical-Driven Software Development (EDSD), as an approach to software development. EDSD manifests the advantages of an ethical framework as an alternative to the all too familiar approach in professional ethics that advocates "stand-alone codes of ethics". We believe that one outcome of this synergy between professional and ethical skills is simply better engineers. Moreover, since there are often different software solutions, which the engineer can provide to an issue at stake, the ethical framework provides a guiding principle, within the process of software development, that helps the engineer evaluate the advantages and disadvantages of different software solutions. It does not and cannot affect the end-product in and of-itself. However, it can and should, make the software engineer more conscious and aware of the ethical ramifications of certain engineering decisions within the process.

Engineering scalable biological systems

PubMed Central

2010-01-01

Synthetic biology is focused on engineering biological organisms to study natural systems and to provide new solutions for pressing medical, industrial and environmental problems. At the core of engineered organisms are synthetic biological circuits that execute the tasks of sensing inputs, processing logic and performing output functions. In the last decade, significant progress has been made in developing basic designs for a wide range of biological circuits in bacteria, yeast and mammalian systems. However, significant challenges in the construction, probing, modulation and debugging of synthetic biological systems must be addressed in order to achieve scalable higher-complexity biological circuits. Furthermore, concomitant efforts to evaluate the safety and biocontainment of engineered organisms and address public and regulatory concerns will be necessary to ensure that technological advances are translated into real-world solutions. PMID:21468204

Revisiting software specification and design for large astronomy projects

NASA Astrophysics Data System (ADS)

Wiant, Scott; Berukoff, Steven

2016-07-01

The separation of science and engineering in the delivery of software systems overlooks the true nature of the problem being solved and the organization that will solve it. Use of a systems engineering approach to managing the requirements flow between these two groups as between a customer and contractor has been used with varying degrees of success by well-known entities such as the U.S. Department of Defense. However, treating science as the customer and engineering as the contractor fosters unfavorable consequences that can be avoided and opportunities that are missed. For example, the "problem" being solved is only partially specified through the requirements generation process since it focuses on detailed specification guiding the parties to a technical solution. Equally important is the portion of the problem that will be solved through the definition of processes and staff interacting through them. This interchange between people and processes is often underrepresented and under appreciated. By concentrating on the full problem and collaborating on a strategy for its solution a science-implementing organization can realize the benefits of driving towards common goals (not just requirements) and a cohesive solution to the entire problem. The initial phase of any project when well executed is often the most difficult yet most critical and thus it is essential to employ a methodology that reinforces collaboration and leverages the full suite of capabilities within the team. This paper describes an integrated approach to specifying the needs induced by a problem and the design of its solution.

Introduction to bioengineering: melding of engineering and biological sciences.

PubMed

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.

Optimal Robust Matching of Engine Models to Test Data

DTIC Science & Technology

2009-02-28

Monte Carlo process 19 Figure 7: Flowchart of SVD Calculations 22 Figure 8: Schematic Diagram of NPSS Engine Model Components 24 Figure 9: PW2037...System Simulation ( NPSS ). NPSS is an object-oriented modeling environment widely used throughout industry and the USAF. With NPSS , the engine is...34 modifiers are available for adjusting the component representations. The scripting language in NPSS allowed for easy implementation of each solution

SCOUSE: Semi-automated multi-COmponent Universal Spectral-line fitting Engine

NASA Astrophysics Data System (ADS)

Henshaw, J. D.; Longmore, S. N.; Kruijssen, J. M. D.; Davies, B.; Bally, J.; Barnes, A.; Battersby, C.; Burton, M.; Cunningham, M. R.; Dale, J. E.; Ginsburg, A.; Immer, K.; Jones, P. A.; Kendrew, S.; Mills, E. A. C.; Molinari, S.; Moore, T. J. T.; Ott, J.; Pillai, T.; Rathborne, J.; Schilke, P.; Schmiedeke, A.; Testi, L.; Walker, D.; Walsh, A.; Zhang, Q.

2016-01-01

The Semi-automated multi-COmponent Universal Spectral-line fitting Engine (SCOUSE) is a spectral line fitting algorithm that fits Gaussian files to spectral line emission. It identifies the spatial area over which to fit the data and generates a grid of spectral averaging areas (SAAs). The spatially averaged spectra are fitted according to user-provided tolerance levels, and the best fit is selected using the Akaike Information Criterion, which weights the chisq of a best-fitting solution according to the number of free-parameters. A more detailed inspection of the spectra can be performed to improve the fit through an iterative process, after which SCOUSE integrates the new solutions into the solution file.

Data management for Computer-Aided Engineering (CAE)

NASA Technical Reports Server (NTRS)

Bryant, W. A.; Smith, M. R.

1984-01-01

Analysis of data flow through the design and manufacturing processes has established specific information management requirements and identified unique problems. The application of data management technology to the engineering/manufacturing environment addresses these problems. An overview of the IPAD prototype data base management system, representing a partial solution to these problems, is presented here.

Software Engineering Design Principles Applied to Instructional Design: What Can We Learn from Our Sister Discipline?

ERIC Educational Resources Information Center

Adnan, Nor Hafizah; Ritzhaupt, Albert D.

2018-01-01

The failure of many instructional design initiatives is often attributed to poor instructional design. Current instructional design models do not provide much insight into design processes for creating e-learning instructional solutions. Given the similarities between the fields of instructional design and software engineering, instructional…

Off-Design Analysis of a High Bypass Turbofan Using a Pulsed Detonation Combustor

DTIC Science & Technology

2010-03-01

Engine Off-Design Results.............................................................39 Code Verification and Operating Limit ...38 4.4. Maximum Operating Limit Baseline and Hybrid Engine ......................................... 41 4.5. Throttle...that an isentropic expansion process takes place followed by a heat rejection to close the cycle. The derivation for the solutions for the Chapman

Vers l'elimination des dessins d'ingenierie des processus de modification d'ingenierie en aeronautique

NASA Astrophysics Data System (ADS)

Quintana, Virgilio

For many years, 3D models and 2D drawings have been the main basic elements that together form and carry a product's definition throughout its lifecycle. With the advent of the Digital Product Definition trend, the Aerospace and Automotive industries have been very interested in adopting a Model-based Definition (MBD) approach that promises reduced time-to-market and improved product quality. Its main purpose is to improve and accelerate the design, manufacturing and inspection processes by integrating drawing annotations directly onto a 3D model, thereby minimizing the need to generate engineering drawings. Even though CAD tools and international standards support the MBD concept, its implementation throughout the whole product lifecycle has not yet been fully adopted; traditional engineering drawings still play an essential part in the capture and distribution of non-geometric data (tolerances, notes, etc.), in the long-term storage of product definitions, as well as in the management of engineering changes. This is especially so within the Engineering Change Management (ECM) process, which involves the study, review, annotation, validation, approval and release of engineering drawings. The exploration of alternatives to reengineer the ECM process in the absence of drawings is therefore a necessary step before the MBD approach can be broadly accepted. The objective of this research project was to propose a solution to conduct the ECM process in a drawing-less environment and to quantify its potential gains. Two Canadian aerospace companies participated in this project. First, the main barriers to be overcome in order to fully implement the MBD initiative were identified. Our observations were based on forty-one interviews conducted within the Engineering, Drafting, Configuration Management, Airworthiness, Certification, Manufacturing, Inspection and Knowledge Management departments from the two participating companies. The results indicated that there is a need to define how the Product Definition will be carried in this drawing-less environment while supporting all of the downstream users' specific requirements. Next, a solution to conduct an MBD-driven Engineering Change Management Process (ECM) was developed and evaluated based on the process requirements from both companies. The solution consists of the definition of a dataset composed of the MBD model (generated by the CAD system) and a lightweight distribution file (generated and exploited by the visualization application). The ECM process was then reengineered to support its execution when working with MBD datasets. Finally, the gains from administering the MBD-driven ECM process were determined using empirical and experimental data within a discrete-event simulation approach. Based on a case study conducted in a Canadian aerospace company, our results show that a reduction of about 11% can be achieved in both the average overall processing time and in the average cost.

Delivering Software Process-Specific Project Courses in Tertiary Education Environment: Challenges and Solution

ERIC Educational Resources Information Center

Rong, Guoping; Shao, Dong

2012-01-01

The importance of delivering software process courses to software engineering students has been more and more recognized in China in recent years. However, students usually cannot fully appreciate the value of software process courses by only learning methodology and principle in the classroom. Therefore, a process-specific project course was…

Double patterning from design enablement to verification

NASA Astrophysics Data System (ADS)

Abercrombie, David; Lacour, Pat; El-Sewefy, Omar; Volkov, Alex; Levine, Evgueni; Arb, Kellen; Reid, Chris; Li, Qiao; Ghosh, Pradiptya

2011-11-01

Litho-etch-litho-etch (LELE) is the double patterning (DP) technology of choice for 20 nm contact, via, and lower metal layers. We discuss the unique design and process characteristics of LELE DP, the challenges they present, and various solutions. ∘ We examine DP design methodologies, current DP conflict feedback mechanisms, and how they can help designers identify and resolve conflicts. ∘ In place and route (P&R), the placement engine must now be aware of the assumptions made during IP cell design, and use placement directives provide by the library designer. We examine the new effects DP introduces in detail routing, discuss how multiple choices of LELE and the cut allowances can lead to different solutions, and describe new capabilities required by detail routers and P&R engines. ∘ We discuss why LELE DP cuts and overlaps are critical to optical process correction (OPC), and how a hybrid mechanism of rule and model-based overlap generation can provide a fast and effective solution. ∘ With two litho-etch steps, mask misalignment and image rounding are now verification considerations. We present enhancements to the OPCVerify engine that check for pinching and bridging in the presence of DP overlay errors and acute angles.

Self-Organization and the Self-Assembling Process in Tissue Engineering

PubMed Central

Eswaramoorthy, Rajalakshmanan; Hadidi, Pasha; Hu, Jerry C.

2015-01-01

In recent years, the tissue engineering paradigm has shifted to include a new and growing subfield of scaffoldless techniques which generate self-organizing and self-assembling tissues. This review aims to provide a cogent description of this relatively new research area, with special emphasis on applications toward clinical use and research models. Particular emphasis is placed on providing clear definitions of self-organization and the self-assembling process, as delineated from other scaffoldless techniques in tissue engineering and regenerative medicine. Significantly, during formation, self-organizing and self-assembling tissues display biological processes similar to those that occur in vivo. These help lead to the recapitulation of native tissue morphological structure and organization. Notably, functional properties of these tissues also approach native tissue values; some of these engineered tissues are already in clinical trials. This review aims to provide a cohesive summary of work in this field, and to highlight the potential of self-organization and the self-assembling process to provide cogent solutions to current intractable problems in tissue engineering. PMID:23701238

Improvement of Selected Logistics Processes Using Quality Engineering Tools

NASA Astrophysics Data System (ADS)

Zasadzień, Michał; Žarnovský, Jozef

2018-03-01

Increase in the number of orders, the increasing quality requirements and the speed of order preparation require implementation of new solutions and improvement of logistics processes. Any disruption that occurs during execution of an order often leads to customer dissatisfaction, as well as loss of his/her confidence. The article presents a case study of the use of quality engineering methods and tools to improve the e-commerce logistic process. This made it possible to identify and prioritize key issues, identify their causes, and formulate improvement and prevention measures.

Incorporating geoethics into environmental engineering lectures - three years of experience from international students visiting Iceland

NASA Astrophysics Data System (ADS)

Finger, David C.

2017-04-01

Never before has human kind been facing bigger environmental challenges than today. The challenges are overwhelming: growing human population, increasing ecological footprints, accelerated climate change, severe soil degradation, eutrophication of vital fresh water resources, acidification of oceans, health threatening air pollution and rapid biodiversity loss, to name just a few. It is the task of environmental scientists to transmit established knowledge on these complex and interdisciplinary challenges while demonstrating that management and engineering solutions exist to meet these threats. In this presentation I will outline the concept of my environmental impact (EI) assessment course, where prospective engineering students can select a topic of their choice, assess the environmental impacts, discuss with relevant stakeholders and come up with innovative solutions. The course is structured in three parts: i) lecturing of theoretical methods frequently used within the EI assessment process, ii) interaction with local businesses to acquire first-hand experience and iii) hands on training by writing an EI statement on a selected topic (see link below). Over the course of three years over 70 prospective engineering students from all over the world have not only acquired environmental system understanding, but also enhanced their awareness and developed potential solutions to mitigate, compensate and reverse the persistent environmental challenges. Most importantly, during this process all involved stakeholders (students, teachers, industry partners, governmental bodies and NGO partners) will hopefully develop a mutual understanding of the above mentioned environmental challenges and engage in an open and constructive dialogue necessary to generate acceptable solutions. Link to student projects from previous years: https://fingerd.jimdo.com/teaching/courses/environmental-impact-assessment/

Real-Time Simulation of the X-33 Aerospace Engine

NASA Technical Reports Server (NTRS)

Aguilar, Robert

1999-01-01

This paper discusses the development and performance of the X-33 Aerospike Engine RealTime Model. This model was developed for the purposes of control law development, six degree-of-freedom trajectory analysis, vehicle system integration testing, and hardware-in-the loop controller verification. The Real-Time Model uses time-step marching solution of non-linear differential equations representing the physical processes involved in the operation of a liquid propellant rocket engine, albeit in a simplified form. These processes include heat transfer, fluid dynamics, combustion, and turbomachine performance. Two engine models are typically employed in order to accurately model maneuvering and the powerpack-out condition where the power section of one engine is used to supply propellants to both engines if one engine malfunctions. The X-33 Real-Time Model is compared to actual hot fire test data and is been found to be in good agreement.

Engineering of layered, lipid-encapsulated drug nanoparticles through spray-drying.

PubMed

Sapra, Mahak; Mayya, Y S; Venkataraman, Chandra

2017-06-01

Drug-containing nanoparticles have been synthesized through the spray-drying of submicron droplet aerosols by using matrix materials such as lipids and biopolymers. Understanding layer formation in composite nanoparticles is essential for the appropriate engineering of particle substructures. The present study developed a droplet-shrinkage model for predicting the solid-phase formation of two non-volatile solutes-stearic acid lipid and a set of drugs, by considering molecular volume and solubility. Nanoparticle formation was simulated to define the parameter space of material properties and process conditions for the formation of a layered structure with the preferential accumulation of the lipid in the outer layer. Moreover, lipid-drug demarcation diagrams representing a set of critical values of ratios of solute properties at which the two solutes precipitate simultaneously were developed. The model was validated through the preparation of stearic acid-isoniazid nanoparticles under controlled processing conditions. The developed model can guide the selection of solvents, lipids, and processing conditions such that drug loading and lipid encapsulation in composite nanoparticles are optimized. Copyright © 2017 Elsevier B.V. All rights reserved.

Product Lifecycle Management and the Quest for Sustainable Space Exploration Solutions

NASA Technical Reports Server (NTRS)

Caruso, Pamela W.; Dumbacher, Daniel L.

2010-01-01

Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Engineering Directorate at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center, total lifecycle costs are important variables for critical decisionmaking. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful tool to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This paper will demonstrate how the Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions. It has been 30 years since the United States fielded the Space Shuttle. The next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. The outcome is a better use of scarce resources, along with more focus on stakeholder and customer requirements, as a new portfolio of enabling tools becomes second nature to the workforce. This paper will use the design and manufacturing processes, which have transitioned to digital-based activities, to show how PLM supports the comprehensive systems engineering and integration function. It also will go through a launch countdown scenario where an anomaly is detected to show how the virtual vehicle created from paperless processes will help solve technical challenges and improve the likelihood of launching on schedule, with less hands-on labor needed for processing and troubleshooting. Sustainable space exploration solutions demand that all lifecycle phases be optimized. Adopting PLM, which has been used by the automotive industry for many years, for aerospace applications provides a foundation for strong, disciplined systems engineering and accountable return on investment by making lifecycle considerations variables in an iterative decision-making process. This paper combines the perspectives of the founding father of PLM, along with the experience of Engineering leaders who are implementing these processes and practices real-time. As the nation moves from an industrial-based society to one where information is a valued commodity, future NASA programs and projects will benefit from the experience being gained today for the exploration missions of tomorrow.

Engineered Osmosis for Energy Efficient Separations: Optimizing Waste Heat Utilization FINAL SCIENTIFIC REPORT DOE F 241.3

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

NATHAN HANCOCK

2013-01-13

The purpose of this study is to design (i) a stripper system where heat is used to strip ammonia (NH{sub 3}) and carbon dioxide (CO{sub 2}) from a diluted draw solution; and (ii) a condensation or absorption system where the stripped NH{sub 3} and CO{sub 2} are captured in condensed water to form a re-concentrated draw solution. This study supports the Industrial Technologies Program of the DOE Office of Energy Efficiency and Renewable Energy and their Industrial Energy Efficiency Grand Challenge award solicitation. Results from this study show that stimulated Oasys draw solutions composed of a complex electrolyte solution associatedmore » with the dissolution of NH{sub 3} and CO{sub 2} gas in water can successfully be stripped and fully condensed under standard atmospheric pressure. Stripper bottoms NH{sub 3} concentration can reliably be reduced to < 1 mg/L, even when starting with liquids that have an NH{sub 3} mass fraction exceeding 6% to stimulate diluted draw solution from the forward osmosis membrane component of the process. Concentrated draw solution produced by fully condensing the stripper tops was show to exceed 6 M-C with nitrogen-to-carbon (N:C) molar ratios on the order of two. Reducing the operating pressure of the stripper column serves to reduce the partial vapor pressure of both NH{sub 3} and CO{sub 2} in solution and enables lower temperature operation towards integration of industrial low-grade of waste heat. Effective stripping of solutes was observed with operating pressures as low as 100 mbar (3-inHg). Systems operating at reduced pressure and temperature require additional design considerations to fully condense and absorb these constituents for reuse within the Oasys EO system context. Comparing empirical data with process stimulation models confirmed that several key parameters related to vapor-liquid equilibrium and intrinsic material properties were not accurate. Additional experiments and refinement of material property databases within the chosen process stimulation software was required to improve the reliability of process simulations for engineering design support. Data from experiments was also employed to calculate critical mass transfer and system design parameters (such as the height equivalent to a theoretical plate (HETP)) to aid in process design. When measured in a less than optimal design state for the stripping of NH{sub 3} and CO{sub 2} from a simulated dilute draw solution the HETP for one type of commercial stripper packing material was 1.88 ft/stage. During this study it was observed that the heat duty required to vaporize the draw solution solutes is substantially affected by the amount of water boilup also produced to achieve a low NH{sub 3} stripper bottoms concentration specification. Additionally, fluid loading of the stripper packing media is a critical performance parameter that affects all facets of optimum stripper column performance. Condensation of the draw solution tops vapor requires additional process considerations if being conducted in sub-atmospheric conditions and low temperature. Future work will focus on the commercialization of the Oasys EO technology platform for numerous applications in water and wastewater treatment as well as harvesting low enthalpy energy with our proprietary osmotic heat engine. Engineering design related to thermal integration of Oasys EO technology for both low and hig-grade heat applications is underway. Novel thermal recovery processes are also being investigated in addition to the conventional approaches described in this report. Oasys Water plans to deploy commercial scale systems into the energy and zero liquid discharge markets in 2013. Additional process refinement will lead to integration of low enthalpy renewable heat sources for municipal desalination applications.« less

Engineering workstation: Sensor modeling

NASA Technical Reports Server (NTRS)

Pavel, M; Sweet, B.

1993-01-01

The purpose of the engineering workstation is to provide an environment for rapid prototyping and evaluation of fusion and image processing algorithms. Ideally, the algorithms are designed to optimize the extraction of information that is useful to a pilot for all phases of flight operations. Successful design of effective fusion algorithms depends on the ability to characterize both the information available from the sensors and the information useful to a pilot. The workstation is comprised of subsystems for simulation of sensor-generated images, image processing, image enhancement, and fusion algorithms. As such, the workstation can be used to implement and evaluate both short-term solutions and long-term solutions. The short-term solutions are being developed to enhance a pilot's situational awareness by providing information in addition to his direct vision. The long term solutions are aimed at the development of complete synthetic vision systems. One of the important functions of the engineering workstation is to simulate the images that would be generated by the sensors. The simulation system is designed to use the graphics modeling and rendering capabilities of various workstations manufactured by Silicon Graphics Inc. The workstation simulates various aspects of the sensor-generated images arising from phenomenology of the sensors. In addition, the workstation can be used to simulate a variety of impairments due to mechanical limitations of the sensor placement and due to the motion of the airplane. Although the simulation is currently not performed in real-time, sequences of individual frames can be processed, stored, and recorded in a video format. In that way, it is possible to examine the appearance of different dynamic sensor-generated and fused images.

An improved plating process

NASA Technical Reports Server (NTRS)

Askew, John C.

1994-01-01

An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

Dry Sintering Meets Wet Silver-Ion "Soldering": Charge-Transfer Plasmon Engineering of Solution-Assembled Gold Nanodimers From Visible to Near-Infrared I and II Regions.

PubMed

Fang, Lingling; Wang, Yueliang; Liu, Miao; Gong, Ming; Xu, An; Deng, Zhaoxiang

2016-11-07

Achieving highly tunable and localized surface plasmon resonance up to near infrared (NIR) regions is a key target in nanoplasmonics. In particular, a self-assembly process capable of producing highly uniform and solution-processable nanomaterials with tailor-made plasmonic properties is lacking. We herein address this problem through a conjunctive use of wet Ag + soldering and dry thermal sintering to produce nanodimer-derived structures with precisely engineered charge-transfer plasmon (CTP). The sintered dimers are water soluble, featuring gradually shifted CTP spanning an 800 nm wavelength range (up to NIR II). Upon silica removal, the products are grafted by DNA to offer surface functionality. This process is also adaptable to DNA-linked AuNP dimers toward plasmonic meta-materials via DNA-guided soldering and sintering. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process Inquiry: Analysis of Oral Problem-Solving Skills in Mathematics of Engineering Students

ERIC Educational Resources Information Center

Trance, Naci John C.

2013-01-01

This paper presents another effort in determining the difficulty of engineering students in terms of solving word problems. Students were presented with word problems in algebra. Then, they were asked to solve the word problems orally; that is, before they presented their written solutions, they were required to explain how they understood the…

On one solution of Volterra integral equations of second kind

NASA Astrophysics Data System (ADS)

Myrhorod, V.; Hvozdeva, I.

2016-10-01

A solution of Volterra integral equations of the second kind with separable and difference kernels based on solutions of corresponding equations linking the kernel and resolvent is suggested. On the basis of a discrete functions class, the equations linking the kernel and resolvent are obtained and the methods of their analytical solutions are proposed. A mathematical model of the gas-turbine engine state modification processes in the form of Volterra integral equation of the second kind with separable kernel is offered.

Materials interface engineering for solution-processed photovoltaics.

PubMed

Graetzel, Michael; Janssen, René A J; Mitzi, David B; Sargent, Edward H

2012-08-16

Advances in solar photovoltaics are urgently needed to increase the performance and reduce the cost of harvesting solar power. Solution-processed photovoltaics are cost-effective to manufacture and offer the potential for physical flexibility. Rapid progress in their development has increased their solar-power conversion efficiencies. The nanometre (electron) and micrometre (photon) scale interfaces between the crystalline domains that make up solution-processed solar cells are crucial for efficient charge transport. These interfaces include large surface area junctions between photoelectron donors and acceptors, the intralayer grain boundaries within the absorber, and the interfaces between photoactive layers and the top and bottom contacts. Controlling the collection and minimizing the trapping of charge carriers at these boundaries is crucial to efficiency.

Systems Engineering Awareness

NASA Technical Reports Server (NTRS)

Lucero, John

2016-01-01

The presentation will provide an overview of the fundamentals and principles of Systems Engineering (SE). This includes understanding the processes that are used to assist the engineer in a successful design, build and implementation of solutions. The context of this presentation will be to describe the involvement of SE throughout the life-cycle of a project from cradle to grave. Due to the ever growing number of complex technical problems facing our world, a Systems Engineering approach is desirable for many reasons. The interdisciplinary technical structure of current systems, technical processes representing System Design, Technical Management and Product Realization are instrumental in the development and integration of new technologies into mainstream applications. This tutorial will demonstrate the application of SE tools to these types of problems..

Eco-innovative design approach: Integrating quality and environmental aspects in prioritizing and solving engineering problems

NASA Astrophysics Data System (ADS)

Chakroun, Mahmoud; Gogu, Grigore; Pacaud, Thomas; Thirion, François

2014-09-01

This study proposes an eco-innovative design process taking into consideration quality and environmental aspects in prioritizing and solving technical engineering problems. This approach provides a synergy between the Life Cycle Assessment (LCA), the nonquality matrix, the Theory of Inventive Problem Solving (TRIZ), morphological analysis and the Analytical Hierarchy Process (AHP). In the sequence of these tools, LCA assesses the environmental impacts generated by the system. Then, for a better consideration of environmental aspects, a new tool is developed, the non-quality matrix, which defines the problem to be solved first from an environmental point of view. The TRIZ method allows the generation of new concepts and contradiction resolution. Then, the morphological analysis offers the possibility of extending the search space of solutions in a design problem in a systematic way. Finally, the AHP identifies the promising solution(s) by providing a clear logic for the choice made. Their usefulness has been demonstrated through their application to a case study involving a centrifugal spreader with spinning discs.

Propulsion and Energetics Panel Working Group 13 on Alternative Jet Engine Fuels. Volume 2. Main Report

DTIC Science & Technology

1982-07-01

twenty years the only economically available fuels for aircraft gas turbine engines will be those from the processing of conventional crude petroleum...alternative fuels in new aircraft engines. i.e. problems ir, combustors. turbines . and afterburners. and methods for their solution. - Fuel system...required expertise assigned to each task group. The three areas were. Supply and demand scenarios for aviation turbine fuels in the NATO Nations for the

An Example of Concurrent Engineering

NASA Technical Reports Server (NTRS)

Rowe, Sidney; Whitten, David; Cloyd, Richard; Coppens, Chris; Rodriguez, Pedro

1998-01-01

The Collaborative Engineering Design and Analysis Room (CEDAR) facility allows on-the- spot design review capability for any project during all phases of development. The required disciplines assemble in this facility to work on any problems (analysis, manufacturing, inspection, etc.) associated with a particular design. A small highly focused team of specialists can meet in this room to better expedite the process of developing a solution to an engineering task within the framework of the constraints that are unique to each discipline. This facility provides the engineering tools and translators to develop a concept within the confines of the room or with remote team members that could access the team's data from other locations. The CEDAR area is envisioned as excellent for failure investigation meetings to be conducted where the computer capabilities can be utilized in conjunction with the Smart Board display to develop failure trees, brainstorm failure modes, and evaluate possible solutions.

Multiobjective hyper heuristic scheme for system design and optimization

NASA Astrophysics Data System (ADS)

Rafique, Amer Farhan

2012-11-01

As system design is becoming more and more multifaceted, integrated, and complex, the traditional single objective optimization trends of optimal design are becoming less and less efficient and effective. Single objective optimization methods present a unique optimal solution whereas multiobjective methods present pareto front. The foremost intent is to predict a reasonable distributed pareto-optimal solution set independent of the problem instance through multiobjective scheme. Other objective of application of intended approach is to improve the worthiness of outputs of the complex engineering system design process at the conceptual design phase. The process is automated in order to provide the system designer with the leverage of the possibility of studying and analyzing a large multiple of possible solutions in a short time. This article presents Multiobjective Hyper Heuristic Optimization Scheme based on low level meta-heuristics developed for the application in engineering system design. Herein, we present a stochastic function to manage meta-heuristics (low-level) to augment surety of global optimum solution. Generic Algorithm, Simulated Annealing and Swarm Intelligence are used as low-level meta-heuristics in this study. Performance of the proposed scheme is investigated through a comprehensive empirical analysis yielding acceptable results. One of the primary motives for performing multiobjective optimization is that the current engineering systems require simultaneous optimization of conflicting and multiple. Random decision making makes the implementation of this scheme attractive and easy. Injecting feasible solutions significantly alters the search direction and also adds diversity of population resulting in accomplishment of pre-defined goals set in the proposed scheme.

Training System Device Certification and Qualification Process

DTIC Science & Technology

2013-09-01

Engineering IPT Integrated Product Team ISD Instructional Systems Development ISEO In-Service Engineering Office KSAs Knowledge, Skills, and Attributes...Plan TES Tactical Engagement Simulation TPM Training Pipeline Managers T&R Training and Readiness TRR Test Readiness Review TS Training System...NAWCTSD) is the Navy’s source for a full range of innovative products and services that provide complete training solutions. This includes

ROI on yield data analysis systems through a business process management strategy

NASA Astrophysics Data System (ADS)

Rehani, Manu; Strader, Nathan; Hanson, Jeff

2005-05-01

The overriding motivation for yield engineering is profitability. This is achieved through application of yield management. The first application is to continually reduce waste in the form of yield loss. New products, new technologies and the dynamic state of the process and equipment keep introducing new ways to cause yield loss. In response, the yield management efforts have to continually come up with new solutions to minimize it. The second application of yield engineering is to aid in accurate product pricing. This is achieved through predicting future results of the yield engineering effort. The more accurate the yield prediction, the more accurate the wafer start volume, the more accurate the wafer pricing. Another aspect of yield prediction pertains to gauging the impact of a yield problem and predicting how long that will last. The ability to predict such impacts again feeds into wafer start calculations and wafer pricing. The question then is that if the stakes on yield management are so high why is it that most yield management efforts are run like science and engineering projects and less like manufacturing? In the eighties manufacturing put the theory of constraints1 into practice and put a premium on stability and predictability in manufacturing activities, why can't the same be done for yield management activities? This line of introspection led us to define and implement a business process to manage the yield engineering activities. We analyzed the best known methods (BKM) and deployed a workflow tool to make them the standard operating procedure (SOP) for yield managment. We present a case study in deploying a Business Process Management solution for Semiconductor Yield Engineering in a high-mix ASIC environment. We will present a description of the situation prior to deployment, a window into the development process and a valuation of the benefits.

Additive Manufacturing of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(ε-caprolactone) Blend Scaffolds for Tissue Engineering.

PubMed

Puppi, Dario; Morelli, Andrea; Chiellini, Federica

2017-05-24

Additive manufacturing of scaffolds made of a polyhydroxyalkanoate blended with another biocompatible polymer represents a cost-effective strategy for combining the advantages of the two blend components in order to develop tailored tissue engineering approaches. The aim of this study was the development of novel poly(3-hydroxybutyrate- co -3-hydroxyhexanoate)/ poly(ε-caprolactone) (PHBHHx/PCL) blend scaffolds for tissue engineering by means of computer-aided wet-spinning, a hybrid additive manufacturing technique suitable for processing polyhydroxyalkanoates dissolved in organic solvents. The experimental conditions for processing tetrahydrofuran solutions containing the two polymers at different concentrations (PHBHHx/PCL weight ratio of 3:1, 2:1 or 1:1) were optimized in order to manufacture scaffolds with predefined geometry and internal porous architecture. PHBHHx/PCL scaffolds with a 3D interconnected network of macropores and a local microporosity of the polymeric matrix, as a consequence of the phase inversion process governing material solidification, were successfully fabricated. As shown by scanning electron microscopy, thermogravimetric, differential scanning calorimetric and uniaxial compressive analyses, blend composition significantly influenced the scaffold morphological, thermal and mechanical properties. In vitro biological characterization showed that the developed scaffolds were able to sustain the adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. The additive manufacturing approach developed in this study, based on a polymeric solution processing method avoiding possible material degradation related to thermal treatments, could represent a powerful tool for the development of customized PHBHHx-based blend scaffolds for tissue engineering.

Exact solutions of the population balance equation including particle transport, using group analysis

NASA Astrophysics Data System (ADS)

Lin, Fubiao; Meleshko, Sergey V.; Flood, Adrian E.

2018-06-01

The population balance equation (PBE) has received an unprecedented amount of attention in recent years from both academics and industrial practitioners because of its long history, widespread use in engineering, and applicability to a wide variety of particulate and discrete-phase processes. However it is typically impossible to obtain analytical solutions, although in almost every case a numerical solution of the PBEs can be obtained. In this article, the symmetries of PBEs with homogeneous coagulation kernels involving aggregation, breakage and growth processes and particle transport in one dimension are found by direct solving the determining equations. Using the optimal system of one and two-dimensional subalgebras, all invariant solutions and reduced equations are obtained. In particular, an explicit analytical physical solution is also presented.

Space Transportation System Liftoff Debris Mitigation Process Overview

NASA Technical Reports Server (NTRS)

Mitchell, Michael; Riley, Christopher

2011-01-01

Liftoff debris is a top risk to the Space Shuttle Vehicle. To manage the Liftoff debris risk, the Space Shuttle Program created a team with in the Propulsion Systems Engineering & Integration Office. The Shutt le Liftoff Debris Team harnesses the Systems Engineering process to i dentify, assess, mitigate, and communicate the Liftoff debris risk. T he Liftoff Debris Team leverages off the technical knowledge and expe rtise of engineering groups across multiple NASA centers to integrate total system solutions. These solutions connect the hardware and ana lyses to identify and characterize debris sources and zones contribut ing to the Liftoff debris risk. The solutions incorporate analyses sp anning: the definition and modeling of natural and induced environmen ts; material characterizations; statistical trending analyses, imager y based trajectory analyses; debris transport analyses, and risk asse ssments. The verification and validation of these analyses are bound by conservative assumptions and anchored by testing and flight data. The Liftoff debris risk mitigation is managed through vigilant collab orative work between the Liftoff Debris Team and Launch Pad Operation s personnel and through the management of requirements, interfaces, r isk documentation, configurations, and technical data. Furthermore, o n day of launch, decision analysis is used to apply the wealth of ana lyses to case specific identified risks. This presentation describes how the Liftoff Debris Team applies Systems Engineering in their proce sses to mitigate risk and improve the safety of the Space Shuttle Veh icle.

Sustainable Development and Energy Geotechnology Potential Roles for Geotechnical Engineering

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

FragaszyProgram Dire, Dr. R. J.; Santamarina, Carlos; Espinoza, N.

2011-01-01

The world is facing unprecedented challenges related to energy resources, global climate change, material use, and waste generation. Failure to address these challenges will inhibit the growth of the developing world and will negatively impact the standard of living and security of future generations in all nations. The solutions to these challenges will require multidisciplinary research across the social and physical sciences and engineering. Although perhaps not always recognized, geotechnical engineering expertise is critical to the solution of many energy and sustainability-related problems. Hence, geotechnical engineers and academicians have opportunity and responsibility to contribute to the solution of these worldwidemore » problems. Research will need to be extended to non-standard issues such as thermal properties of soils; sediment and rock response to extreme conditions and at very long time scales; coupled hydro-chemo-thermo-bio-mechanical processes; positive feedback systems; the development of discontinuities; biological modification of soil properties; spatial variability; and emergent phenomena. Clearly, the challenges facing geotechnical engineering in the future will require a much broader knowledge base than our traditional educational programs provide. The geotechnical engineering curricula, from undergraduate education through continuing professional education, must address the changing needs of a profession that will increasingly be engaged in alternative/renewable energy production; energy efficiency; sustainable design, enhanced and more efficient use of natural resources, waste management, and underground utilization.« less

Novel thick-foam ferroelectret with engineered voids for energy harvesting applications

NASA Astrophysics Data System (ADS)

Luo, Z.; Shi, J.; Beeby, S. P.

2016-11-01

This work reports a novel thick-foam ferroelectret which is designed and engineered for energy harvesting applications. We fabricated this ferroelectret foam by mixing a chemical blowing agent with a polymer solution, then used heat treatment to activate the agent and create voids in the polymer foam. The dimensions of the foam, the density and size of voids can be well controlled in the fabrication process. Therefore, this ferroelectret can be engineered into optimized structure for energy harvesting applications.

Pre-Hardware Optimization of Spacecraft Image Processing Algorithms and Hardware Implementation

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Petrick, David J.; Flatley, Thomas P.; Hestnes, Phyllis; Jentoft-Nilsen, Marit; Day, John H. (Technical Monitor)

2002-01-01

Spacecraft telemetry rates and telemetry product complexity have steadily increased over the last decade presenting a problem for real-time processing by ground facilities. This paper proposes a solution to a related problem for the Geostationary Operational Environmental Spacecraft (GOES-8) image data processing and color picture generation application. Although large super-computer facilities are the obvious heritage solution, they are very costly, making it imperative to seek a feasible alternative engineering solution at a fraction of the cost. The proposed solution is based on a Personal Computer (PC) platform and synergy of optimized software algorithms, and reconfigurable computing hardware (RC) technologies, such as Field Programmable Gate Arrays (FPGA) and Digital Signal Processors (DSP). It has been shown that this approach can provide superior inexpensive performance for a chosen application on the ground station or on-board a spacecraft.

A BPMN solution for chaining OGC services to quality assure location-based crowdsourced data

NASA Astrophysics Data System (ADS)

Meek, Sam; Jackson, Mike; Leibovici, Didier G.

2016-02-01

The Open Geospatial Consortium (OGC) Web Processing Service (WPS) standard enables access to a centralized repository of processes and services from compliant clients. A crucial part of the standard includes the provision to chain disparate processes and services to form a reusable workflow. To date this has been realized by methods such as embedding XML requests, using Business Process Execution Language (BPEL) engines and other external orchestration engines. Although these allow the user to define tasks and data artifacts as web services, they are often considered inflexible and complicated, often due to vendor specific solutions and inaccessible documentation. This paper introduces a new method of flexible service chaining using the standard Business Process Markup Notation (BPMN). A prototype system has been developed upon an existing open source BPMN suite to illustrate the advantages of the approach. The motivation for the software design is qualification of crowdsourced data for use in policy-making. The software is tested as part of a project that seeks to qualify, assure, and add value to crowdsourced data in a biological monitoring use case.

A Multidisciplinary Approach to Mixer-Ejector Analysis and Design

NASA Technical Reports Server (NTRS)

Hendricks, Eric, S.; Seidel, Jonathan, A.

2012-01-01

The design of an engine for a civil supersonic aircraft presents a difficult multidisciplinary problem to propulsion system engineers. There are numerous competing requirements for the engine, such as to be efficient during cruise while yet quiet enough at takeoff to meet airport noise regulations. The use of mixer-ejector nozzles presents one possible solution to this challenge. However, designing a mixer-ejector which will successfully address both of these concerns is a difficult proposition. Presented in this paper is an integrated multidisciplinary approach to the analysis and design of these systems. A process that uses several low-fidelity tools to evaluate both the performance and acoustics of mixer-ejectors nozzles is described. This process is further expanded to include system-level modeling of engines and aircraft to determine the effects on mission performance and noise near airports. The overall process is developed in the OpenMDAO framework currently being developed by NASA. From the developed process, sample results are given for a notional mixer-ejector design, thereby demonstrating the capabilities of the method.

Ultrafiltration of Protein Solutions: A Laboratory Experiment

ERIC Educational Resources Information Center

Pansare, Vikram J.; Tien, Daniel; Prud'homme, Robert K.

2015-01-01

Biology is playing an increasingly important role in the chemical engineering curriculum. We describe a set of experiments we have implemented in our Undergraduate Laboratory course giving students practical insights into membrane separation processes for protein processing. The goal of the lab is to optimize the purification and concentration of…

A requirements engineering approach for improving the quality of diabetes education websites.

PubMed

Shabestari, Omid; Roudsari, Abdul

2011-01-01

Diabetes Mellitus is a major chronic disease with multi-organ involvement and high-cost complications. Although it has been proved that structured education can control the risk of developing these complications, there is big room for improvement in the educational services for these patients. e-learning can be a good solution to fill this gap. Most of the current e-learning solutions for diabetes were designed by computer experts and healthcare professionals but the patients, as end-users of these systems, haven't been deeply involved in the design process. Considering the expectations of the patients, this article investigates a requirement engineering process comparing the level of importance given to different attributes of the e-learning by patients and healthcare professionals. The results of this comparison can be used for improving the currently developed online diabetes education systems.

Shared direct memory access on the Explorer 2-LX

NASA Technical Reports Server (NTRS)

Musgrave, Jeffrey L.

1990-01-01

Advances in Expert System technology and Artificial Intelligence have provided a framework for applying automated Intelligence to the solution of problems which were generally perceived as intractable using more classical approaches. As a result, hybrid architectures and parallel processing capability have become more common in computing environments. The Texas Instruments Explorer II-LX is an example of a machine which combines a symbolic processing environment, and a computationally oriented environment in a single chassis for integrated problem solutions. This user's manual is an attempt to make these capabilities more accessible to a wider range of engineers and programmers with problems well suited to solution in such an environment.

Optimization applications in aircraft engine design and test

NASA Technical Reports Server (NTRS)

Pratt, T. K.

1984-01-01

Starting with the NASA-sponsored STAEBL program, optimization methods based primarily upon the versatile program COPES/CONMIN were introduced over the past few years to a broad spectrum of engineering problems in structural optimization, engine design, engine test, and more recently, manufacturing processes. By automating design and testing processes, many repetitive and costly trade-off studies have been replaced by optimization procedures. Rather than taking engineers and designers out of the loop, optimization has, in fact, put them more in control by providing sophisticated search techniques. The ultimate decision whether to accept or reject an optimal feasible design still rests with the analyst. Feedback obtained from this decision process has been invaluable since it can be incorporated into the optimization procedure to make it more intelligent. On several occasions, optimization procedures have produced novel designs, such as the nonsymmetric placement of rotor case stiffener rings, not anticipated by engineering designers. In another case, a particularly difficult resonance contraint could not be satisfied using hand iterations for a compressor blade, when the STAEBL program was applied to the problem, a feasible solution was obtained in just two iterations.

Engineering Geodesy - Definition and Core Competencies

NASA Astrophysics Data System (ADS)

Kuhlmann, Heiner; Schwieger, Volker; Wieser, Andreas; Niemeier, Wolfgang

2014-11-01

This article summarises discussions concerning the definition of "engineering geodesy" within the German Geodetic Commission. It is noted that engineering geodesy by means of its tasks, methods and characteristics is an application-oriented science whose research questions often arise from observed phenomena or from unsolved practical problems. In particular it is characterised by the professional handling of geometry-related problems in a cost-effective manner that includes comprehensive quality assessment at all phases of the problem solution - from planning through measurement to data processing and interpretation. The current methodical developments are primarily characterised by the increasing integration of the measurement and analysis into challenging construction, production and monitoring processes as well as by the transition to spatially continuous methods. A modern definition of engineering geodesy is proposed at the end of this article.

Engineering Lessons Learned and Systems Engineering Applications

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Garcia, Danny; Vaughan, William W.

2005-01-01

Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned and technical standards. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. Systems Engineering has been defined (EINIS-632) as "an interdisciplinary approach encompassing the entire technical effort to evolve and verify an integrated and life-cycle balanced set of system people, product, and process solutions that satisfy customer needs". Designing reliable space-based systems has always been a goal for NASA, and many painful lessons have been learned along the way. One of the continuing functions of a system engineer is to compile development and operations "lessons learned" documents and ensure their integration into future systems development activities. They can produce insights and information for risk identification identification and characterization. on a new project. Lessons learned files from previous projects are especially valuable in risk

The biomaterials conundrum in tissue engineering.

PubMed

Williams, David F

2014-04-01

The development of biomaterials for use in tissue engineering processes has not so far followed a scientifically valid pathway; there have been no properly constituted specifications for these biomaterials, whose choice has often been dictated by the perceived need to comply with prior FDA approval for use of the materials in nontissue engineering applications. This short essay discusses the difficulties that have resulted in this approach and provides both conceptual and practical solutions for the future, based on sound principles of biocompatibility and the need to use tissue engineering templates that replicate the niche of the target cells.

Research in the comprehension of engineering lectures by non-native speakers

NASA Technical Reports Server (NTRS)

Olsen, L. A.; Huckin, T. N.

1981-01-01

Failure by foreign students to perceive the rhetorical structure or overall organization of an engineering lecture, rendering them unable to understand it, is discussed. Equally serious failure by such students to perceive the organizing role of theory in structuring the activities in their field is reported. Failure to identify the role of theory in the problem-solving process that underlies engineering is emphasized. Engineering was not seen as a series of on-going problems where each stage of solution exposed new problems to be solved. Implications for course planners and material designers are discussed.

A Mixed Learning Approach to Integrating Digital Signal Processing Laboratory Exercises into a Non-Lab Junior Year DSP Course

ERIC Educational Resources Information Center

McPheron, Benjamin D.; Thangaraj, Charles V.; Thomas, Charles R.

2017-01-01

Laboratory courses can be difficult to fit into an engineering program at a liberal arts-focused university, which requires students to be exposed to appropriate breadth, as well as sufficient depth in their engineering education. One possible solution to this issue is to integrate laboratory exercises with lecture in a "studio" format,…

Multidimensional Data Modeling for Business Process Analysis

NASA Astrophysics Data System (ADS)

Mansmann, Svetlana; Neumuth, Thomas; Scholl, Marc H.

The emerging area of business process intelligence attempts to enhance the analytical capabilities of business process management systems by employing data warehousing and mining technologies. This paper presents an approach to re-engineering the business process modeling in conformity with the multidimensional data model. Since the business process and the multidimensional model are driven by rather different objectives and assumptions, there is no straightforward solution to converging these models.

Experience in the Education of Engineers from Vietnam in the Faculty of Mining and Geoengineering AGH

NASA Astrophysics Data System (ADS)

Cała, Marek; Borowski, Marek

2018-03-01

The AGH University of Science and Technology collaborates closely with other universities, economic units, governmental and local administrative bodies. International cooperation plays a very important role in the academic research. The AGH University of Science and Technology has signed many collaboration agreements. They aim at multidimensional cooperation in the fields of education and academic research. AGH UST has always focused on collaboration with business and industry. In recent years, the global economy is undergoing massive transformations, what creates new challenges to companies and educational institutions that cater to the needs of industry. The expansion of business enterprises is largely dependent on their employees' expertise, skills and levels of competence. Certified engineers are provided by universities. Therefore, the qualifications of the graduates are determined by the curriculum and teaching methods, as well as the available educational and research facilities. Of equal importance is the qualified academic staff. Human activities in the field of engineering require finding solutions to problems of various nature and magnitude. An engineer's work consists in the design, construction, modification and maintenance of useful devices, processes and systems, using scientific and technical knowledge. In order to design complex engineering solutions, an engineer uses his imagination, experience, analytical skills, logical reasoning and makes conscious use of his knowledge. At the Faculty of Mining and Geoengineering of the AGH University of Science and Technology in Cracow, 15 engineers from Vietnam are studying Mining and Geology at the second-cycle studies (specialization: mine ventilation). The solutions proposed in the field of the engineers' education guarantee that foreign students gain both engineering knowledge and problem-solving skills. Therefore, the study programme was complemented by a series of practical aspects.

A Data-Driven Solution for Performance Improvement

NASA Technical Reports Server (NTRS)

2002-01-01

Marketed as the "Software of the Future," Optimal Engineering Systems P.I. EXPERT(TM) technology offers statistical process control and optimization techniques that are critical to businesses looking to restructure or accelerate operations in order to gain a competitive edge. Kennedy Space Center granted Optimal Engineering Systems the funding and aid necessary to develop a prototype of the process monitoring and improvement software. Completion of this prototype demonstrated that it was possible to integrate traditional statistical quality assurance tools with robust optimization techniques in a user- friendly format that is visually compelling. Using an expert system knowledge base, the software allows the user to determine objectives, capture constraints and out-of-control processes, predict results, and compute optimal process settings.

Including natural systems into the system engineering process: benefits to spaceflight and beyond

NASA Astrophysics Data System (ADS)

Studor, George

2014-03-01

How did we get to the point where we don't have time to be inspired by the wonders of Nature? Our office walls, homes and city streets are so plain that even when we do escape to a retreat with nature all around us, we may be blind to its magnificence. Yet there are many who have applied what can be known of natural systems (NS) to create practical solutions, but often definite applications for them are lacking. Mimicry of natural systems is not only more possible than ever before, but the education and research programs in many major universities are churning out graduates with a real appreciation for Nature's complex integrated systems. What if these skills and perspectives were employed in the teams of systems engineers and the technology developers that support them to help the teams think "outside-the-box" of manmade inventions? If systems engineers (SE) and technology developers regularly asked the question, "what can we learn from Nature that will help us?" as a part of their processes, they would discover another set of potential solutions. Biomimicry and knowledge of natural systems is exploding. What does this mean for systems engineering and technology? Some disciplines such as robotics and medical devices must consider nature constantly. Perhaps it's time for all technology developers and systems engineers to perceive natural systems experts as potential providers of the technologies they need.

A Survey of Statistical Models for Reverse Engineering Gene Regulatory Networks

PubMed Central

Huang, Yufei; Tienda-Luna, Isabel M.; Wang, Yufeng

2009-01-01

Statistical models for reverse engineering gene regulatory networks are surveyed in this article. To provide readers with a system-level view of the modeling issues in this research, a graphical modeling framework is proposed. This framework serves as the scaffolding on which the review of different models can be systematically assembled. Based on the framework, we review many existing models for many aspects of gene regulation; the pros and cons of each model are discussed. In addition, network inference algorithms are also surveyed under the graphical modeling framework by the categories of point solutions and probabilistic solutions and the connections and differences among the algorithms are provided. This survey has the potential to elucidate the development and future of reverse engineering GRNs and bring statistical signal processing closer to the core of this research. PMID:20046885

Value Engineering Synergies with Lean Six Sigma

DTIC Science & Technology

2010-09-01

understanding the problem, developing solutions, and evalu- ating pros and cons of the solutions. The paramount considerations are getting enough facts and...parts or labor operations. Functions are defined for every element of the product or process that con - sumes resources. The functions are typically...shoot bullets, detect movement, and so forth). A work function establishes quantitative statements. Functional definitions con - taining a verb and a

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

Ferrada, J.J.; Osborne-Lee, I.W.; Grizzaffi, P.A.

Expert systems are known to be useful in capturing expertise and applying knowledge to chemical engineering problems such as diagnosis, process control, process simulation, and process advisory. However, expert system applications are traditionally limited to knowledge domains that are heuristic and involve only simple mathematics. Neural networks, on the other hand, represent an emerging technology capable of rapid recognition of patterned behavior without regard to mathematical complexity. Although useful in problem identification, neural networks are not very efficient in providing in-depth solutions and typically do not promote full understanding of the problem or the reasoning behind its solutions. Hence, applicationsmore » of neural networks have certain limitations. This paper explores the potential for expanding the scope of chemical engineering areas where neural networks might be utilized by incorporating expert systems and neural networks into the same application, a process called hybridization. In addition, hybrid applications are compared with those using more traditional approaches, the results of the different applications are analyzed, and the feasibility of converting the preliminary prototypes described herein into useful final products is evaluated. 12 refs., 8 figs.« less

Intelligent Engine Systems Work Element 1.2: Malfunction and Operator Error Reduction

NASA Technical Reports Server (NTRS)

Wiseman, Matthew

2005-01-01

Jet engines, although highly reliable and safe, do experience malfunctions that cause flight delays, passenger stress, and in some cases, in conjunction with inappropriate crew response, contribute to airplane accidents. On rare occasions, the anomalous engine behavior is not recognized until it is too late for the pilots to do anything to prevent or mitigate the resulting engine malfunction causing in-flight shutdowns (IFSDs), aborted takeoffs (ATOs), or loss of thrust control (LOTC). In some cases, the crew response to a myriad of external stimuli and existing training procedures is the source of the problem mentioned above. The problem is the reduction of jet engine malfunctions (IFSDs, ATOs, and LOTC) and inappropriate crew response (PSM+ICR) through the use of evolving and advanced technologies. The solution is to develop the overall system health maintenance architecture, detection and accommodation technologies, processes, and enhanced crew interfaces that would enable a significant reduction in IFSDs, ATOs, and LOTC. This program defines requirements and proposes a preliminary design concept of an architecture that enables the realization of the solution.

A web-based rapid assessment tool for production publishing solutions

NASA Astrophysics Data System (ADS)

Sun, Tong

2010-02-01

Solution assessment is a critical first-step in understanding and measuring the business process efficiency enabled by an integrated solution package. However, assessing the effectiveness of any solution is usually a very expensive and timeconsuming task which involves lots of domain knowledge, collecting and understanding the specific customer operational context, defining validation scenarios and estimating the expected performance and operational cost. This paper presents an intelligent web-based tool that can rapidly assess any given solution package for production publishing workflows via a simulation engine and create a report for various estimated performance metrics (e.g. throughput, turnaround time, resource utilization) and operational cost. By integrating the digital publishing workflow ontology and an activity based costing model with a Petri-net based workflow simulation engine, this web-based tool allows users to quickly evaluate any potential digital publishing solutions side-by-side within their desired operational contexts, and provides a low-cost and rapid assessment for organizations before committing any purchase. This tool also benefits the solution providers to shorten the sales cycles, establishing a trustworthy customer relationship and supplement the professional assessment services with a proven quantitative simulation and estimation technology.

Additive Manufacturing of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(ε-caprolactone) Blend Scaffolds for Tissue Engineering

PubMed Central

Puppi, Dario; Morelli, Andrea; Chiellini, Federica

2017-01-01

Additive manufacturing of scaffolds made of a polyhydroxyalkanoate blended with another biocompatible polymer represents a cost-effective strategy for combining the advantages of the two blend components in order to develop tailored tissue engineering approaches. The aim of this study was the development of novel poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/ poly(ε-caprolactone) (PHBHHx/PCL) blend scaffolds for tissue engineering by means of computer-aided wet-spinning, a hybrid additive manufacturing technique suitable for processing polyhydroxyalkanoates dissolved in organic solvents. The experimental conditions for processing tetrahydrofuran solutions containing the two polymers at different concentrations (PHBHHx/PCL weight ratio of 3:1, 2:1 or 1:1) were optimized in order to manufacture scaffolds with predefined geometry and internal porous architecture. PHBHHx/PCL scaffolds with a 3D interconnected network of macropores and a local microporosity of the polymeric matrix, as a consequence of the phase inversion process governing material solidification, were successfully fabricated. As shown by scanning electron microscopy, thermogravimetric, differential scanning calorimetric and uniaxial compressive analyses, blend composition significantly influenced the scaffold morphological, thermal and mechanical properties. In vitro biological characterization showed that the developed scaffolds were able to sustain the adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. The additive manufacturing approach developed in this study, based on a polymeric solution processing method avoiding possible material degradation related to thermal treatments, could represent a powerful tool for the development of customized PHBHHx-based blend scaffolds for tissue engineering. PMID:28952527

Effect of a new regeneration process by adsorption-coagulation and flocculation on the physicochemical properties and the detergent efficiency of regenerated cleaning solutions.

PubMed

Blel, Walid; Dif, Mehdi; Sire, Olivier

2015-05-15

Reprocessing soiled cleaning-in-place (CIP) solutions has large economic and environmental costs, and it would be cheaper and greener to recycle them. In food industries, recycling of CIP solutions requires a suitable green process engineered to take into account the extreme physicochemical conditions of cleaning while not altering the process efficiency. To this end, an innovative treatment process combining adsorption-coagulation with flocculation was tested on multiple recycling of acid and basic cleaning solutions. In-depth analysis of time-course evolutions was carried out in the physicochemical properties (concentration, surface tension, viscosity, COD, total nitrogen) of these solutions over the course of successive regenerations. Cleaning and disinfection efficiencies were assessed based on both microbiological analyses and organic matter detachment and solubilization from fouled stainless steel surfaces. Microbiological analyses using a resistant bacterial strain (Bacillus subtilis spores) highlighted that solutions regenerated up to 20 times maintained the same bactericidal efficiency as de novo NaOH solutions. The cleanability of stainless steel surfaces showed that regenerated solutions allow better surface wettability, which goes to explain the improved detachment and solubilization found on different types of organic and inorganic fouling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Engineering charge transport by heterostructuring solution-processed semiconductors

NASA Astrophysics Data System (ADS)

Voznyy, Oleksandr; Sutherland, Brandon R.; Ip, Alexander H.; Zhitomirsky, David; Sargent, Edward H.

2017-06-01

Solution-processed semiconductor devices are increasingly exploiting heterostructuring — an approach in which two or more materials with different energy landscapes are integrated into a composite system. Heterostructured materials offer an additional degree of freedom to control charge transport and recombination for more efficient optoelectronic devices. By exploiting energetic asymmetry, rationally engineered heterostructured materials can overcome weaknesses, augment strengths and introduce emergent physical phenomena that are otherwise inaccessible to single-material systems. These systems see benefit and application in two distinct branches of charge-carrier manipulation. First, they influence the balance between excitons and free charges to enhance electron extraction in solar cells and photodetectors. Second, they promote radiative recombination by spatially confining electrons and holes, which increases the quantum efficiency of light-emitting diodes. In this Review, we discuss advances in the design and composition of heterostructured materials, consider their implementation in semiconductor devices and examine unexplored paths for future advancement in the field.

Reducing neural network training time with parallel processing

NASA Technical Reports Server (NTRS)

Rogers, James L., Jr.; Lamarsh, William J., II

1995-01-01

Obtaining optimal solutions for engineering design problems is often expensive because the process typically requires numerous iterations involving analysis and optimization programs. Previous research has shown that a near optimum solution can be obtained in less time by simulating a slow, expensive analysis with a fast, inexpensive neural network. A new approach has been developed to further reduce this time. This approach decomposes a large neural network into many smaller neural networks that can be trained in parallel. Guidelines are developed to avoid some of the pitfalls when training smaller neural networks in parallel. These guidelines allow the engineer: to determine the number of nodes on the hidden layer of the smaller neural networks; to choose the initial training weights; and to select a network configuration that will capture the interactions among the smaller neural networks. This paper presents results describing how these guidelines are developed.

Improving TOGAF ADM 9.1 Migration Planning Phase by ITIL V3 Service Transition

NASA Astrophysics Data System (ADS)

Hanum Harani, Nisa; Akhmad Arman, Arry; Maulana Awangga, Rolly

2018-04-01

Modification planning of business transformation involving technological utilization required a system of transition and migration planning process. Planning of system migration activity is the most important. The migration process is including complex elements such as business re-engineering, transition scheme mapping, data transformation, application development, individual involvement by computer and trial interaction. TOGAF ADM is the framework and method of enterprise architecture implementation. TOGAF ADM provides a manual refer to the architecture and migration planning. The planning includes an implementation solution, in this case, IT solution, but when the solution becomes an IT operational planning, TOGAF could not handle it. This paper presents a new model framework detail transitions process of integration between TOGAF and ITIL. We evaluated our models in field study inside a private university.

Adaptive building skin structures

NASA Astrophysics Data System (ADS)

Del Grosso, A. E.; Basso, P.

2010-12-01

The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method.

The early career researcher's toolkit: translating tissue engineering, regenerative medicine and cell therapy products.

PubMed

Rafiq, Qasim A; Ortega, Ilida; Jenkins, Stuart I; Wilson, Samantha L; Patel, Asha K; Barnes, Amanda L; Adams, Christopher F; Delcassian, Derfogail; Smith, David

2015-11-01

Although the importance of translation for the development of tissue engineering, regenerative medicine and cell-based therapies is widely recognized, the process of translation is less well understood. This is particularly the case among some early career researchers who may not appreciate the intricacies of translational research or make decisions early in development which later hinders effective translation. Based on our own research and experiences as early career researchers involved in tissue engineering and regenerative medicine translation, we discuss common pitfalls associated with translational research, providing practical solutions and important considerations which will aid process and product development. Suggestions range from effective project management, consideration of key manufacturing, clinical and regulatory matters and means of exploiting research for successful commercialization.

Supply Chain Engineering and the Use of a Supporting Knowledge Management Application

NASA Astrophysics Data System (ADS)

Laakmann, Frank

The future competition in markets will happen between logistics networks and no longer between enterprises. A new approach for supporting the engineering of logistics networks is developed by this research as a part of the Collaborative Research Centre (SFB) 559: "Modeling of Large Networks in Logistics" at the University of Dortmund together with the Fraunhofer-Institute of Material Flow and Logistics founded by Deutsche Forschungsgemeinschaft (DFG). Based on a reference model for logistics processes, the process chain model, a guideline for logistics engineers is developed to manage the different types of design tasks of logistics networks. The technical background of this solution is a collaborative knowledge management application. This paper will introduce how new Internet-based technologies support supply chain design projects.

The Maia Spectroscopy Detector System: Engineering for Integrated Pulse Capture, Low-Latency Scanning and Real-Time Processing

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

Kirkham, R.; Siddons, D.; Dunn, P.A.

2010-06-23

The Maia detector system is engineered for energy dispersive x-ray fluorescence spectroscopy and elemental imaging at photon rates exceeding 10{sup 7}/s, integrated scanning of samples for pixel transit times as small as 50 {micro}s and high definition images of 10{sup 8} pixels and real-time processing of detected events for spectral deconvolution and online display of pure elemental images. The system developed by CSIRO and BNL combines a planar silicon 384 detector array, application-specific integrated circuits for pulse shaping and peak detection and sampling and optical data transmission to an FPGA-based pipelined, parallel processor. This paper describes the system and themore » underpinning engineering solutions.« less

High-temperature microelectromechanical pressure sensors based on a SOI heterostructure for an electronic automatic aircraft engine control system

NASA Astrophysics Data System (ADS)

Sokolov, Leonid V.

2010-08-01

There is a need of measuring distributed pressure on the aircraft engine inlet with high precision within a wide operating temperature range in the severe environment to improve the efficiency of aircraft engine control. The basic solutions and principles of designing high-temperature (to 523K) microelectromechanical pressure sensors based on a membrane-type SOI heterostructure with a monolithic integral tensoframe (MEMS-SOIMT) are proposed in accordance with the developed concept, which excludes the use of electric p-n junctions in semiconductor microelectromechanical sensors. The MEMS-SOIMT technology relies on the group processes of microelectronics and micromechanics for high-precision microprofiling of a three-dimension micromechanical structure, which exclude high-temperature silicon doping processes.

Nonlinear Systems.

ERIC Educational Resources Information Center

Seider, Warren D.; Ungar, Lyle H.

1987-01-01

Describes a course in nonlinear mathematics courses offered at the University of Pennsylvania which provides an opportunity for students to examine the complex solution spaces that chemical engineers encounter. Topics include modeling many chemical processes, especially those involving reaction and diffusion, auto catalytic reactions, phase…

Aggregation and Deposition of C60 in Aqueous Systems

EPA Science Inventory

The extremely low water solubility of many fullerenes precludes aqueous solution processing for engineering applications and minimizes the potential for fullerene environmental effects in aqueous environments. However, studies have shown that C60 fullerene can form stable colloi...

Collecting, processing, and integrating GPS data into GIS

DOT National Transportation Integrated Search

2002-01-01

A vast storehouse of information exists on nearly every subject of concern to highway : administrators and engineers. Much of this information has resulted from both research : and the successful application of solutions to the problems faced by prac...

33 CFR 384.10 - How does the Corps of Engineers make efforts to accommodate intergovernmental concerns?

Code of Federal Regulations, 2011 CFR

2011-07-01

... either: (1) Accepts the recommendation; (2) Reaches a mutually agreeable solution with the state process... Corps official, has reviewed the case and determined that, because of unusual circumstances, the waiting...

33 CFR 384.10 - How does the Corps of Engineers make efforts to accommodate intergovernmental concerns?

Code of Federal Regulations, 2010 CFR

2010-07-01

... either: (1) Accepts the recommendation; (2) Reaches a mutually agreeable solution with the state process... Corps official, has reviewed the case and determined that, because of unusual circumstances, the waiting...

Precision manufacturing for clinical-quality regenerative medicines.

PubMed

Williams, David J; Thomas, Robert J; Hourd, Paul C; Chandra, Amit; Ratcliffe, Elizabeth; Liu, Yang; Rayment, Erin A; Archer, J Richard

2012-08-28

Innovations in engineering applied to healthcare make a significant difference to people's lives. Market growth is guaranteed by demographics. Regulation and requirements for good manufacturing practice-extreme levels of repeatability and reliability-demand high-precision process and measurement solutions. Emerging technologies using living biological materials add complexity. This paper presents some results of work demonstrating the precision automated manufacture of living materials, particularly the expansion of populations of human stem cells for therapeutic use as regenerative medicines. The paper also describes quality engineering techniques for precision process design and improvement, and identifies the requirements for manufacturing technology and measurement systems evolution for such therapies.

Translating Vision into Design: A Method for Conceptual Design Development

NASA Technical Reports Server (NTRS)

Carpenter, Joyce E.

2003-01-01

One of the most challenging tasks for engineers is the definition of design solutions that will satisfy high-level strategic visions and objectives. Even more challenging is the need to demonstrate how a particular design solution supports the high-level vision. This paper describes a process and set of system engineering tools that have been used at the Johnson Space Center to analyze and decompose high-level objectives for future human missions into design requirements that can be used to develop alternative concepts for vehicles, habitats, and other systems. Analysis and design studies of alternative concepts and approaches are used to develop recommendations for strategic investments in research and technology that support the NASA Integrated Space Plan. In addition to a description of system engineering tools, this paper includes a discussion of collaborative design practices for human exploration mission architecture studies used at the Johnson Space Center.

Euler solutions for an unbladed jet engine configuration

NASA Technical Reports Server (NTRS)

Stewart, Mark E. M.

1991-01-01

A Euler solution for an axisymmetric jet engine configuration without blade effects is presented. The Euler equations are solved on a multiblock grid which covers a domain including the inlet, bypass duct, core passage, nozzle, and the far field surrounding the engine. The simulation is verified by considering five theoretical properties of the solution. The solution demonstrates both multiblock grid generation techniques and a foundation for a full jet engine throughflow calculation.

DETOX{sup SM} catalyzed wet oxidation as a highly suitable pretreatment for vitrification

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

Rogers, T.W.; Dhooge, P.M.; Goldblatt, S.D.

1995-11-01

A catalyzed wet oxidation process has been developed which uses ferric iron in an acidic water solution to oxidize organic compounds in the presence of platinum ion and/or ruthenium ion catalysts. The process is capable of oxidizing a wide range of organic compounds to carbon dioxide and water with great efficiency. The process has been tested in the bench-scale with many different types of organics. Conceptual engineering for application of the process to treatment of liquid and solid organic waste materials has been followed by engineering design for a demonstration unit. Fabrication of the unit and demonstration on hazardous andmore » mixed wastes at two Department of Energy sites is planned in 1995 through 1997.« less

The Role of Re-Appropriation in Open Design: A Case Study on How Openness in Higher Education for Industrial Design Engineering Can Trigger Global Discussions on the Theme of Urban Gardening

ERIC Educational Resources Information Center

Ostuzzi, Francesca; Conradie, Peter; De Couvreur, Lieven; Detand, Jan; Saldien, Jelle

2016-01-01

This case study explores the opportunities for students of Industrial Design Engineering to engage with direct and indirect stakeholders by making their design process and results into open-ended designed solutions. The reported case study involved 47 students during a two-weeks intensive course on the topic of urban gardening. Observations were…

Application of the Billet Casting Method to Determine the Onset of Incipient Melting of 319 Al Alloy Engine Blocks

NASA Astrophysics Data System (ADS)

Lombardi, A.; Ravindran, C.; MacKay, R.

2015-06-01

The increased use of Al for automotive applications has resulted from the need to improve vehicle fuel efficiency. Aluminum alloy engine blocks fulfil the need of lightweighting. However, there are many challenges associated with thermo-mechanical mismatch between Al and the gray cast iron cylinder liners, which result in large tensile residual stress along the cylinder bores. This requires improced mechanical properties in this region to prevent premature engine failure. In this study, replicating billet castings were used to simulate the engine block solution heat treatment process and determine the onset of incipient melting. Microstructural changes during heat treatment were assessed with SEM and EDX, while thermal analysis was carried out using differential scanning calorimetry. The results suggest that solution heat treatment at 500 °C was effective in dissolving secondary phase particles, while solutionizing at 515 or 530 °C caused incipient melting of Al2Cu and Al5Mg8Cu2Si6. Incipient melting caused the formation ultra-fine eutectic clusters consisting of Al, Al2Cu, and Al5Mg8Cu2Si6 on quenching. In addition, DSC analysis found that incipient melting initiated at 507 °C for all billets, although the quantity of local melting reduced with microstructural refinement as evidenced by smaller endothermic peaks and energy absorption. The results from this study will assist in improving engine block casting integrity and process efficiency.

Interference-free Micro/nanoparticle Cell Engineering by Use of High-Throughput Microfluidic Separation.

PubMed

Yeo, David C; Wiraja, Christian; Zhou, Yingying; Tay, Hui Min; Xu, Chenjie; Hou, Han Wei

2015-09-23

Engineering cells with active-ingredient-loaded micro/nanoparticles is becoming increasingly popular for imaging and therapeutic applications. A critical yet inadequately addressed issue during its implementation concerns the significant number of particles that remain unbound following the engineering process, which inadvertently generate signals and impart transformative effects onto neighboring nontarget cells. Here we demonstrate that those unbound micro/nanoparticles remaining in solution can be efficiently separated from the particle-labeled cells by implementing a fast, continuous, and high-throughput Dean flow fractionation (DFF) microfluidic device. As proof-of-concept, we applied the DFF microfluidic device for buffer exchange to sort labeled suspension cells (THP-1) from unbound fluorescent dye and dye-loaded micro/nanoparticles. Compared to conventional centrifugation, the depletion efficiency of free dyes or particles was improved 20-fold and the mislabeling of nontarget bystander cells by free particles was minimized. The microfluidic device was adapted to further accommodate heterogeneous-sized mesenchymal stem cells (MSCs). Complete removal of unbound nanoparticles using DFF led to the usage of engineered MSCs without exerting off-target transformative effects on the functional properties of neighboring endothelial cells. Apart from its effectiveness in removing free particles, this strategy is also efficient and scalable. It could continuously process cell solutions with concentrations up to 10(7) cells·mL(-1) (cell densities commonly encountered during cell therapy) without observable loss of performance. Successful implementation of this technology is expected to pave the way for interference-free clinical application of micro/nanoparticle engineered cells.

ENGINEERING BULLETIN: IN SITU SOIL FLUSHING

EPA Science Inventory

In situ soil flushing is the extraction of contaminants from the soil with water or other suitable aqueous solutions. Soil flushing is accomplished by passing the extraction fluid through in-place soils using an injection or infiltration process. Extraction fluids must be recover...

Engineering of the institutionalization of the circular economy at the level of casting production

NASA Astrophysics Data System (ADS)

Vescan, M. M.; Soporan, V. F.; Crișan, D. M.; Lehene, T. R.; Pădurețu, S.; Samuila, V.

2017-06-01

This paper is motivated by the necessity of introducing the principles of circular economy at the level of different social - economic activities, and from this point of view one of the fields with a special potential is that of the manufacture of castings. Objective: to connect to the organizing and application of the methodology of the circular economy principles. The proposed method is an innovating one, being connected to the use of institutionalization engineering. Formulating the subject: The subject formulated to be solved aims at the introduction of new approaches, defined through institutionalization engineering, which proposes to set the correlation of actions between the specifics of the circular economy and the specific elements of the manufacture of castings. Research method: An institutional structuring operation was imposed for the optimization of the research method, in which different versions interact at the following levels: the level of public policies, the level of the regulatory framework, the level of technical solutions and the level of financing solutions and financial instruments. The determination of the optimal solution established in a dynamic context, favorable for the requirements of the different actors present within the process, appeals to the elements of critical thinking, specific for the engineer’s actions. Achievement of the research activity: The research activity structures a methodology of quantifying the contributions of each stage of the manufacturing process for castings at the fulfilling of the specific conditions of the circular economy, indicating the critical areas of action for more efficient actions of the circular economy, according to the market economy requirements, where there is a potential of implementing the technical solutions by quantizing the financial solutions and the opportunity of using the financial instruments. The major contribution of the research: The proposed methodology, with examples at the level of castings manufacture, sets the bases of a new field of action of the engineering thinking, namely, that of circular economy institutionalization functioning. Conclusions of the research activity: The proposed methodology represents the bases of establishing a new instrument of action at the level of institutionalized functioning of the circular economy.

Solution-Processed Organic and Halide Perovskite Transistors on Hydrophobic Surfaces.

PubMed

Ward, Jeremy W; Smith, Hannah L; Zeidell, Andrew; Diemer, Peter J; Baker, Stephen R; Lee, Hyunsu; Payne, Marcia M; Anthony, John E; Guthold, Martin; Jurchescu, Oana D

2017-05-31

Solution-processable electronic devices are highly desirable due to their low cost and compatibility with flexible substrates. However, they are often challenging to fabricate due to the hydrophobic nature of the surfaces of the constituent layers. Here, we use a protein solution to modify the surface properties and to improve the wettability of the fluoropolymer dielectric Cytop. The engineered hydrophilic surface is successfully incorporated in bottom-gate solution-deposited organic field-effect transistors (OFETs) and hybrid organic-inorganic trihalide perovskite field-effect transistors (HTP-FETs) fabricated on flexible substrates. Our analysis of the density of trapping states at the semiconductor-dielectric interface suggests that the increase in the trap density as a result of the chemical treatment is minimal. As a result, the devices exhibit good charge carrier mobilities, near-zero threshold voltages, and low electrical hysteresis.

Solution plasma applications for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers

NASA Astrophysics Data System (ADS)

Watthanaphanit, Anyarat; Saito, Nagahiro

2018-01-01

Reducing the use of toxic chemicals, production steps, and time consumption are important concerns for researchers and process engineers to contribute in the quest for an efficient process in any production. If an equipment setup is simple, the process additionally becomes more profitable. Combination of the mentioned requirements has opened up various applications of the solution plasma process (SPP) — a physical means of generating plasma through an electrical discharge in a liquid medium at atmospheric pressure and room temperature. This review shows the progress of scientific research on the applications of the SPP for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers. Development achieved in each application is demonstrated.

Zeolite Coating System for Corrosion Control to Eliminate Hexavalent Chromium from DoD Applications

DTIC Science & Technology

2009-08-01

Beving D.; Munoz R.; Yushan Y. 2005, Hydrothermal Synthesis and Corrosion Resistance of Vanadium ZSM-5 Films, The American Institute of Chemical...Engineers National Meeting, October 30 - November 4, Cincinnati, Ohio. 8) Mao Y.; Beving D.; Munoz R.; Yushan Y. 2005, Hydrothermal Synthesis of...directly at the solid-liquid interface from a synthesis solution during the coating formation process (Figure 2-4)12. The synthesis solution used is a

Efficient Defect Engineering for Solution Combustion Processed In-Zn-O thin films for high performance transistors

NASA Astrophysics Data System (ADS)

Liang, Xiaoci; Wang, Chengcai; Liang, Jun; Liu, Chuan; Pei, Yanli

2017-09-01

The oxygen related defects in the solution combustion-processed InZnO vitally affect the field-effect mobility and on-off characteristics in thin film transistors (TFTs). We use photoelectron spectroscopy to reveal that these defects can be well controlled by adjusting the atmosphere and flow rate during the combustion reaction, but are hardly affected by further post-annealing after the reaction. In device performance, the threshold voltage of the InZnO-TFTs was regulated in a wide range from 3.5 V to 11.0 V. To compromise the high field-effect mobility and good subthreshold properties, we fabricate the TFTs with double active layers of InZnO to achieve vertical gradience in defect distribution. The resulting TFT exhibits much higher field-effect mobility as 17.5 cm2 · V-1 · s-1, a low reversed sub-threshold slope as 0.35 V/decade, and a high on-off ratio as 107. The presented understandings and methods on defect engineering are efficient in improving the device performance of TFTs made from the combustion reaction process.

A systems engineering management approach to resource management applications

NASA Technical Reports Server (NTRS)

Hornstein, Rhoda Shaller

1989-01-01

The author presents a program management response to the following question: How can the traditional practice of systems engineering management, including requirements specification, be adapted, enhanced, or modified to build future planning and scheduling systems for effective operations? The systems engineering management process, as traditionally practiced, is examined. Extensible resource management systems are discussed. It is concluded that extensible systems are a partial solution to problems presented by requirements that are incomplete, partially immeasurable, and often dynamic. There are positive indications that resource management systems have been characterized and modeled sufficiently to allow their implementation as extensible systems.

Machine Learning Techniques in Optimal Design

NASA Technical Reports Server (NTRS)

Cerbone, Giuseppe

1992-01-01

Many important applications can be formalized as constrained optimization tasks. For example, we are studying the engineering domain of two-dimensional (2-D) structural design. In this task, the goal is to design a structure of minimum weight that bears a set of loads. A solution to a design problem in which there is a single load (L) and two stationary support points (S1 and S2) consists of four members, E1, E2, E3, and E4 that connect the load to the support points is discussed. In principle, optimal solutions to problems of this kind can be found by numerical optimization techniques. However, in practice [Vanderplaats, 1984] these methods are slow and they can produce different local solutions whose quality (ratio to the global optimum) varies with the choice of starting points. Hence, their applicability to real-world problems is severely restricted. To overcome these limitations, we propose to augment numerical optimization by first performing a symbolic compilation stage to produce: (a) objective functions that are faster to evaluate and that depend less on the choice of the starting point and (b) selection rules that associate problem instances to a set of recommended solutions. These goals are accomplished by successive specializations of the problem class and of the associated objective functions. In the end, this process reduces the problem to a collection of independent functions that are fast to evaluate, that can be differentiated symbolically, and that represent smaller regions of the overall search space. However, the specialization process can produce a large number of sub-problems. This is overcome by deriving inductively selection rules which associate problems to small sets of specialized independent sub-problems. Each set of candidate solutions is chosen to minimize a cost function which expresses the tradeoff between the quality of the solution that can be obtained from the sub-problem and the time it takes to produce it. The overall solution to the problem, is then obtained by solving in parallel each of the sub-problems in the set and computing the one with the minimum cost. In addition to speeding up the optimization process, our use of learning methods also relieves the expert from the burden of identifying rules that exactly pinpoint optimal candidate sub-problems. In real engineering tasks it is usually too costly to the engineers to derive such rules. Therefore, this paper also contributes to a further step towards the solution of the knowledge acquisition bottleneck [Feigenbaum, 1977] which has somewhat impaired the construction of rulebased expert systems.

A self-assessment of the propensity to obtain future employment: a case of final-year engineering students at the University of Botswana

NASA Astrophysics Data System (ADS)

Ssegawa, Joseph K.; Kasule, Daniel

2017-09-01

The article provides a self-assessment by final-year engineering students at the University of Botswana regarding the propensity to get employment. Students rated which employability attributes are important, the level of attainment and the sources that have facilitated the development of the attributes. Results indicated that students identified the most important attributes as management of time; possessing a high level of technical skills, meeting deadlines and creating viable solutions for solving a problem. They also indicated that they have weaknesses in managing time, meeting deadlines and creating viable solutions (attributes critical to the engineering profession). Students reported that their strengths were in having a positive attitude, orderly physical presentation, adaptation to new environments and willingness to learn new ideas. Students further noted that they developed the attributes from the university academic system followed by their own private activities. The study concludes that students lacked some of the critical attributes of engineering. They therefore, need to be explicitly and holistically sensitised as to how the attributes relate to their profession, employment and career development. As part of the review of the engineering programmes, sensitisation could be included in the induction process at enrolment.

A Nonlinear, Multiinput, Multioutput Process Control Laboratory Experiment

ERIC Educational Resources Information Center

Young, Brent R.; van der Lee, James H.; Svrcek, William Y.

2006-01-01

Experience in using a user-friendly software, Mathcad, in the undergraduate chemical reaction engineering course is discussed. Example problems considered for illustration deal with simultaneous solution of linear algebraic equations (kinetic parameter estimation), nonlinear algebraic equations (equilibrium calculations for multiple reactions and…

Analyst-to-Analyst Variability in Simulation-Based Prediction

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

Glickman, Matthew R.; Romero, Vicente J.

This report describes findings from the culminating experiment of the LDRD project entitled, "Analyst-to-Analyst Variability in Simulation-Based Prediction". For this experiment, volunteer participants solving a given test problem in engineering and statistics were interviewed at different points in their solution process. These interviews are used to trace differing solutions to differing solution processes, and differing processes to differences in reasoning, assumptions, and judgments. The issue that the experiment was designed to illuminate -- our paucity of understanding of the ways in which humans themselves have an impact on predictions derived from complex computational simulations -- is a challenging and openmore » one. Although solution of the test problem by analyst participants in this experiment has taken much more time than originally anticipated, and is continuing past the end of this LDRD, this project has provided a rare opportunity to explore analyst-to-analyst variability in significant depth, from which we derive evidence-based insights to guide further explorations in this important area.« less

Assessment and evaluation of engineering options at a low-level radioactive waste storage site

NASA Astrophysics Data System (ADS)

Kanehiro, B. Y.; Guvanasen, V.

1982-09-01

Solutions to hydrologic and geotechnical problems associated with existing disposal sites were sought and the efficiency of engineering options that were proposed to improve the integrity of such sites were evaluated. The Weldon Spring site is generally like other low-level nuclear waste sites, except that the wastes are primarily in the form of residues and contaminated rubble from the processing of uranium and thorium ores rather than industrial isotopes or mill tailings.

Engineering the Charge Transport of Ag Nanocrystals for Highly Accurate, Wearable Temperature Sensors through All-Solution Processes.

PubMed

Joh, Hyungmok; Lee, Seung-Wook; Seong, Mingi; Lee, Woo Seok; Oh, Soong Ju

2017-06-01

All-nanocrystal (NC)-based and all-solution-processed wearable resistance temperature detectors (RTDs) are introduced. The charge transport mechanisms of Ag NC thin films are engineered through various ligand treatments to design high performance RTDs. Highly conductive Ag NC thin films exhibiting metallic transport behavior with high positive temperature coefficients of resistance (TCRs) are achieved through tetrabutylammonium bromide treatment. Ag NC thin films showing hopping transport with high negative TCRs are created through organic ligand treatment. All-solution-based, one-step photolithography techniques that integrate two distinct opposite-sign TCR Ag NC thin films into an ultrathin single device are developed to decouple the mechanical effects such as human motion. The unconventional materials design and strategy enables highly accurate, sensitive, wearable and motion-free RTDs, demonstrated by experiments on moving or curved objects such as human skin, and simulation results based on charge transport analysis. This strategy provides a low cost and simple method to design wearable multifunctional sensors with high sensitivity which could be utilized in various fields such as biointegrated sensors or electronic skin. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CASIS Fact Sheet: Hardware and Facilities

NASA Technical Reports Server (NTRS)

Solomon, Michael R.; Romero, Vergel

2016-01-01

Vencore is a proven information solutions, engineering, and analytics company that helps our customers solve their most complex challenges. For more than 40 years, we have designed, developed and delivered mission-critical solutions as our customers' trusted partner. The Engineering Services Contract, or ESC, provides engineering and design services to the NASA organizations engaged in development of new technologies at the Kennedy Space Center. Vencore is the ESC prime contractor, with teammates that include Stinger Ghaffarian Technologies, Sierra Lobo, Nelson Engineering, EASi, and Craig Technologies. The Vencore team designs and develops systems and equipment to be used for the processing of space launch vehicles, spacecraft, and payloads. We perform flight systems engineering for spaceflight hardware and software; develop technologies that serve NASA's mission requirements and operations needs for the future. Our Flight Payload Support (FPS) team at Kennedy Space Center (KSC) provides engineering, development, and certification services as well as payload integration and management services to NASA and commercial customers. Our main objective is to assist principal investigators (PIs) integrate their science experiments into payload hardware for research aboard the International Space Station (ISS), commercial spacecraft, suborbital vehicles, parabolic flight aircrafts, and ground-based studies. Vencore's FPS team is AS9100 certified and a recognized implementation partner for the Center for Advancement of Science in Space (CASIS

Desired Precision in Multi-Objective Optimization: Epsilon Archiving or Rounding Objectives?

NASA Astrophysics Data System (ADS)

Asadzadeh, M.; Sahraei, S.

2016-12-01

Multi-objective optimization (MO) aids in supporting the decision making process in water resources engineering and design problems. One of the main goals of solving a MO problem is to archive a set of solutions that is well-distributed across a wide range of all the design objectives. Modern MO algorithms use the epsilon dominance concept to define a mesh with pre-defined grid-cell size (often called epsilon) in the objective space and archive at most one solution at each grid-cell. Epsilon can be set to the desired precision level of each objective function to make sure that the difference between each pair of archived solutions is meaningful. This epsilon archiving process is computationally expensive in problems that have quick-to-evaluate objective functions. This research explores the applicability of a similar but computationally more efficient approach to respect the desired precision level of all objectives in the solution archiving process. In this alternative approach each objective function is rounded to the desired precision level before comparing any new solution to the set of archived solutions that already have rounded objective function values. This alternative solution archiving approach is compared to the epsilon archiving approach in terms of efficiency and quality of archived solutions for solving mathematical test problems and hydrologic model calibration problems.

Automated smoother for the numerical decoupling of dynamics models.

PubMed

Vilela, Marco; Borges, Carlos C H; Vinga, Susana; Vasconcelos, Ana Tereza R; Santos, Helena; Voit, Eberhard O; Almeida, Jonas S

2007-08-21

Structure identification of dynamic models for complex biological systems is the cornerstone of their reverse engineering. Biochemical Systems Theory (BST) offers a particularly convenient solution because its parameters are kinetic-order coefficients which directly identify the topology of the underlying network of processes. We have previously proposed a numerical decoupling procedure that allows the identification of multivariate dynamic models of complex biological processes. While described here within the context of BST, this procedure has a general applicability to signal extraction. Our original implementation relied on artificial neural networks (ANN), which caused slight, undesirable bias during the smoothing of the time courses. As an alternative, we propose here an adaptation of the Whittaker's smoother and demonstrate its role within a robust, fully automated structure identification procedure. In this report we propose a robust, fully automated solution for signal extraction from time series, which is the prerequisite for the efficient reverse engineering of biological systems models. The Whittaker's smoother is reformulated within the context of information theory and extended by the development of adaptive signal segmentation to account for heterogeneous noise structures. The resulting procedure can be used on arbitrary time series with a nonstationary noise process; it is illustrated here with metabolic profiles obtained from in-vivo NMR experiments. The smoothed solution that is free of parametric bias permits differentiation, which is crucial for the numerical decoupling of systems of differential equations. The method is applicable in signal extraction from time series with nonstationary noise structure and can be applied in the numerical decoupling of system of differential equations into algebraic equations, and thus constitutes a rather general tool for the reverse engineering of mechanistic model descriptions from multivariate experimental time series.

Additive manufacturing techniques for the production of tissue engineering constructs.

PubMed

Mota, Carlos; Puppi, Dario; Chiellini, Federica; Chiellini, Emo

2015-03-01

'Additive manufacturing' (AM) refers to a class of manufacturing processes based on the building of a solid object from three-dimensional (3D) model data by joining materials, usually layer upon layer. Among the vast array of techniques developed for the production of tissue-engineering (TE) scaffolds, AM techniques are gaining great interest for their suitability in achieving complex shapes and microstructures with a high degree of automation, good accuracy and reproducibility. In addition, the possibility of rapidly producing tissue-engineered constructs meeting patient's specific requirements, in terms of tissue defect size and geometry as well as autologous biological features, makes them a powerful way of enhancing clinical routine procedures. This paper gives an extensive overview of different AM techniques classes (i.e. stereolithography, selective laser sintering, 3D printing, melt-extrusion-based techniques, solution/slurry extrusion-based techniques, and tissue and organ printing) employed for the development of tissue-engineered constructs made of different materials (i.e. polymeric, ceramic and composite, alone or in combination with bioactive agents), by highlighting their principles and technological solutions. Copyright © 2012 John Wiley & Sons, Ltd.

76 FR 13666 - Pitney Bowes, Inc., Mailing Solutions Management, Global Engineering Group, Including On-Site...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

...., Mailing Solutions Management, Global Engineering Group, Including On-Site Leased Workers From Guidant... workers and former workers of Pitney Bowes, Inc., Mailing Solutions Management Division, Engineering... reviewed the certification to clarify the subject worker group's identity. Additional information revealed...

CMAS-Resistant Plasma Sprayed Thermal Barrier Coatings Based on Y2O3-Stabilized ZrO2 with Al3+ and Ti4+ Solute Additions

NASA Astrophysics Data System (ADS)

Senturk, Bilge S.; Garces, Hector F.; Ortiz, Angel L.; Dwivedi, Gopal; Sampath, Sanjay; Padture, Nitin P.

2014-04-01

The higher operating temperatures in gas-turbine engines made possible by thermal barrier coatings (TBCs) are engendering a new problem: environmentally ingested airborne silicate particles (sand, ash) melt on the hot TBC surfaces and form calcium-magnesium-alumino-silicate (CMAS) glass deposits. The molten CMAS glass degrades the TBCs, leading to their premature failure. Here, we demonstrate the use of a commercially manufactured feedstock powder, in conjunction with air plasma spray process, to deposit CMAS-resistant yttria-stabilized zirconia-based TBCs containing Al3+ and Ti4+ in solid solution. Results from the characterization of these new TBCs and CMAS/TBCs interaction experiments are presented. The CMAS mitigation mechanisms in these new TBCs involve the crystallization of the anorthite phase. Raman microscopy is used to generate large area maps of the anorthite phase in the CMAS-interacted TBCs demonstrating the potential usefulness of this method for studying CMAS/TBCs interactions. The ubiquity of airborne sand/ash particles and the ever-increasing demand for higher operating temperatures in future high efficiency gas-turbine engines will necessitate CMAS resistance in all hot-section components of those engines. In this context, the versatility, ease of processing, and low cost offered by the process demonstrated here could benefit the development of these new CMAS-resistant TBCs.

Inpatient preanalytic process improvements.

PubMed

Wagar, Elizabeth A; Phipps, Ron; Del Guidice, Robert; Middleton, Lavinia P; Bingham, John; Prejean, Cheryl; Johnson-Hamilton, Martha; Philip, Pheba; Le, Ngoc Han; Muses, Waheed

2013-12-01

Phlebotomy services are a common target for preanalytic improvements. Many new, quality engineering tools have recently been applied in clinical laboratories. However, data on relatively few projects have been published. This example describes a complete application of current, quality engineering tools to improve preanalytic phlebotomy services. To decrease the response time in the preanalytic inpatient laboratory by 25%, to reduce the number of incident reports related to preanalytic phlebotomy, and to make systematic process changes that satisfied the stakeholders. The Department of Laboratory Medicine, General Services Section, at the University of Texas MD Anderson Cancer Center (Houston) is responsible for inpatient phlebotomy in a 24-hour operation, which serves 689 inpatient beds. The study director was project director of the Division of Pathology and Laboratory Medicine's Quality Improvement Section and was assisted by 2 quality technologists and an industrial engineer from MD Anderson Office of Performance Improvement. After implementing each solution, using well-recognized, quality tools and metrics, the response time for blood collection decreased by 23%, which was close to meeting the original responsiveness goal of 25%. The response time between collection and arrival in the laboratory decreased by 8%. Applicable laboratory-related incident reports were reduced by 43%. Comprehensive application of quality tools, such as statistical control charts, Pareto diagrams, value-stream maps, process failure modes and effects analyses, fishbone diagrams, solution prioritization matrices, and customer satisfaction surveys can significantly improve preset goals for inpatient phlebotomy.

Integrated System-Level Optimization for Concurrent Engineering With Parametric Subsystem Modeling

NASA Technical Reports Server (NTRS)

Schuman, Todd; DeWeck, Oliver L.; Sobieski, Jaroslaw

2005-01-01

The introduction of concurrent design practices to the aerospace industry has greatly increased the productivity of engineers and teams during design sessions as demonstrated by JPL's Team X. Simultaneously, advances in computing power have given rise to a host of potent numerical optimization methods capable of solving complex multidisciplinary optimization problems containing hundreds of variables, constraints, and governing equations. Unfortunately, such methods are tedious to set up and require significant amounts of time and processor power to execute, thus making them unsuitable for rapid concurrent engineering use. This paper proposes a framework for Integration of System-Level Optimization with Concurrent Engineering (ISLOCE). It uses parametric neural-network approximations of the subsystem models. These approximations are then linked to a system-level optimizer that is capable of reaching a solution quickly due to the reduced complexity of the approximations. The integration structure is described in detail and applied to the multiobjective design of a simplified Space Shuttle external fuel tank model. Further, a comparison is made between the new framework and traditional concurrent engineering (without system optimization) through an experimental trial with two groups of engineers. Each method is evaluated in terms of optimizer accuracy, time to solution, and ease of use. The results suggest that system-level optimization, running as a background process during integrated concurrent engineering sessions, is potentially advantageous as long as it is judiciously implemented.

All-Solution-Processed Metal-Oxide-Free Flexible Organic Solar Cells with Over 10% Efficiency.

PubMed

Song, Wei; Fan, Xi; Xu, Bingang; Yan, Feng; Cui, Huiqin; Wei, Qiang; Peng, Ruixiang; Hong, Ling; Huang, Jiaming; Ge, Ziyi

2018-05-16

All-solution-processing at low temperatures is important and desirable for making printed photovoltaic devices and also offers the possibility of a safe and cost-effective fabrication environment for the devices. Herein, an all-solution-processed flexible organic solar cell (OSC) using poly(3,4-ethylenedioxythiophene):poly-(styrenesulfonate) electrodes is reported. The all-solution-processed flexible devices yield the highest power conversion efficiency of 10.12% with high fill factor of over 70%, which is the highest value for metal-oxide-free flexible OSCs reported so far. The enhanced performance is attributed to the newly developed gentle acid treatment at room temperature that enables a high-performance PEDOT:PSS/plastic underlying substrate with a matched work function (≈4.91 eV), and the interface engineering that endows the devices with better interface contacts and improved hole mobility. Furthermore, the flexible devices exhibit an excellent mechanical flexibility, as indicated by a high retention (≈94%) of the initial efficiency after 1000 bending cycles. This work provides a simple route to fabricate high-performance all-solution-processed flexible OSCs, which is important for the development of printing, blading, and roll-to-roll technologies. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Processing multilevel secure test and evaluation information

NASA Astrophysics Data System (ADS)

Hurlburt, George; Hildreth, Bradley; Acevedo, Teresa

1994-07-01

The Test and Evaluation Community Network (TECNET) is building a Multilevel Secure (MLS) system. This system features simultaneous access to classified and unclassified information and easy access through widely available communications channels. It provides the necessary separation of classification levels, assured through the use of trusted system design techniques, security assessments and evaluations. This system enables cleared T&E users to view and manipulate classified and unclassified information resources either using a single terminal interface or multiple windows in a graphical user interface. TECNET is in direct partnership with the National Security Agency (NSA) to develop and field the MLS TECNET capability in the near term. The centerpiece of this partnership is a state-of-the-art Concurrent Systems Security Engineering (CSSE) process. In developing the MLS TECNET capability, TECNET and NSA are providing members, with various expertise and diverse backgrounds, to participate in the CSSE process. The CSSE process is founded on the concepts of both Systems Engineering and Concurrent Engineering. Systems Engineering is an interdisciplinary approach to evolve and verify an integrated and life cycle balanced set of system product and process solutions that satisfy customer needs (ASD/ENS-MIL STD 499B 1992). Concurrent Engineering is design and development using the simultaneous, applied talents of a diverse group of people with the appropriate skills. Harnessing diverse talents to support CSSE requires active participation by team members in an environment that both respects and encourages diversity.

Phthalocyanine Blends Improve Bulk Heterojunction Solar Cells

PubMed Central

Varotto, Alessandro; Nam, Chang-Yong; Radivojevic, Ivana; Tomé, Joao; Cavaleiro, José A.S.; Black, Charles T.; Drain, Charles Michael

2010-01-01

A core phthalocyanine platform allows engineering the solubility properties the band gap; shifting the maximum absorption toward the red. A simple method to increase the efficiency of heterojunction solar cells uses a self-organized blend of the phthalocyanine chromophores fabricated by solution processing. PMID:20136126

Transformation toughened ceramics for the heavy duty diesel engine technology program

NASA Technical Reports Server (NTRS)

Musikant, S.; Feingold, E.; Rauch, H.; Samanta, S.

1984-01-01

The objective of this program is to develop an advanced high temperature oxide structural ceramic for application to the heavy duty diesel engine. The approach is to employ transformation toughening by additions of ZrO.5HfO.5O2 solid solution to the oxide ceramics, mullite (2Al2O3S2SiO2) and alumina (Al2O3). The study is planned for three phases, each 12 months in duration. This report covers Phase 1. During this period, processing techniques were developed to incorporate the ZrO.5HfO.5O2 solid solution in the matrices while retaining the necessary metastable tetragonal phase. Modulus of rupture and of elasticity, coefficient of thermal expansion, fracture toughness by indent technique and thermal diffusivity of representative specimens were measured. In Phase 2, the process will be improved to provide higher mechanical strength and to define the techniques for scale up to component size. In Phase 3, full scale component prototypes will be fabri-]cated.

A Measurement & Analysis Training Solution Supporting CMMI & Six Sigma Transition

DTIC Science & Technology

2004-10-01

product” • Designing an integrated training solution • Illustration(s) © 2004 by Carnegie Mellon University Version 1.0 page 5 Carnegie Mellon S...12207 Score- card EIA 632 ISO 9000 ITIL COBIT PSM GQIM © 2004 by Carnegie Mellon University Version 1.0 page 7 Carnegie Mellon S oftware Engineer ing...several Capability Maturity Models, reflects Crosby’s 5 maturity levels • Focuses on infrastructure and process maturity • Intended for software and

Nano and microparticle engineering of water insoluble drugs using a novel spray-drying process.

PubMed

Schafroth, Nina; Arpagaus, Cordin; Jadhav, Umesh Y; Makne, Sushil; Douroumis, Dennis

2012-02-01

In the current study nano and microparticle engineering of water insoluble drugs was conducted using a novel piezoelectric spray-drying approach. Cyclosporin A (CyA) and dexamethasone (DEX) were encapsulated in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) grades of different molecular weights. Spray-drying studies carried out with the Nano Spray Dryer B-90 employed with piezoelectric driven actuator. The processing parameters including inlet temperature, spray mesh diameter, sample flow rate, spray rate, applied pressure and sample concentration were examined in order to optimize the particle size and the obtained yield. The process parameters and the solute concentration showed a profound effect on the particle engineering and the obtained product yield. The produced powder presented consistent and reproducible spherical particles with narrow particle size distribution. Cyclosporin was found to be molecularly dispersed while dexamethasone was in crystalline state within the PLGA nanoparticles. Further evaluation revealed excellent drug loading, encapsulation efficiency and production yield. In vitro studies demonstrated sustained release patterns for the active substances. This novel spray-drying process proved to be efficient for nano and microparticle engineering of water insoluble active substances. Copyright © 2011 Elsevier B.V. All rights reserved.

Information System Engineering Supporting Observation, Orientation, Decision, and Compliant Action

NASA Astrophysics Data System (ADS)

Georgakopoulos, Dimitrios

The majority of today's software systems and organizational/business structures have been built on the foundation of solving problems via long-term data collection, analysis, and solution design. This traditional approach of solving problems and building corresponding software systems and business processes, falls short in providing the necessary solutions needed to deal with many problems that require agility as the main ingredient of their solution. For example, such agility is needed in responding to an emergency, in military command control, physical security, price-based competition in business, investing in the stock market, video gaming, network monitoring and self-healing, diagnosis in emergency health care, and many other areas that are too numerous to list here. The concept of Observe, Orient, Decide, and Act (OODA) loops is a guiding principal that captures the fundamental issues and approach for engineering information systems that deal with many of these problem areas. However, there are currently few software systems that are capable of supporting OODA. In this talk, we provide a tour of the research issues and state of the art solutions for supporting OODA. In addition, we provide specific examples of OODA solutions we have developed for the video surveillance and emergency response domains.

Eight-dimensional methodology for innovative thinking about the case and ethics of the Mount Graham, Large Binocular Telescope project.

PubMed

Berne, Rosalyn W; Raviv, Daniel

2004-04-01

This paper introduces the Eight Dimensional Methodology for Innovative Thinking (the Eight Dimensional Methodology), for innovative problem solving, as a unified approach to case analysis that builds on comprehensive problem solving knowledge from industry, business, marketing, math, science, engineering, technology, arts, and daily life. It is designed to stimulate innovation by quickly generating unique "out of the box" unexpected and high quality solutions. It gives new insights and thinking strategies to solve everyday problems faced in the workplace, by helping decision makers to see otherwise obscure alternatives and solutions. Daniel Raviv, the engineer who developed the Eight Dimensional Methodology, and paper co-author, technology ethicist Rosalyn Berne, suggest that this tool can be especially useful in identifying solutions and alternatives for particular problems of engineering, and for the ethical challenges which arise with them. First, the Eight Dimensional Methodology helps to elucidate how what may appear to be a basic engineering problem also has ethical dimensions. In addition, it offers to the engineer a methodology for penetrating and seeing new dimensions of those problems. To demonstrate the effectiveness of the Eight Dimensional Methodology as an analytical tool for thinking about ethical challenges to engineering, the paper presents the case of the construction of the Large Binocular Telescope (LBT) on Mount Graham in Arizona. Analysis of the case offers to decision makers the use of the Eight Dimensional Methodology in considering alternative solutions for how they can proceed in their goals of exploring space. It then follows that same process through the second stage of exploring the ethics of each of those different solutions. The LBT project pools resources from an international partnership of universities and research institutes for the construction and maintenance of a highly sophisticated, powerful new telescope. It will soon mark the erection of the world's largest and most powerful optical telescope, designed to see fine detail otherwise visible only from space. It also represents a controversial engineering project that is being undertaken on land considered to be sacred by the local, native Apache people. As presented, the case features the University of Virginia, and its challenges in consideration of whether and how to join the LBT project consortium.

Energy and technology review: Engineering modeling

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

Cabayan, H.S.; Goudreau, G.L.; Ziolkowski, R.W.

1986-10-01

This report presents information concerning: Modeling Canonical Problems in Electromagnetic Coupling Through Apertures; Finite-Element Codes for Computing Electrostatic Fields; Finite-Element Modeling of Electromagnetic Phenomena; Modeling Microwave-Pulse Compression in a Resonant Cavity; Lagrangian Finite-Element Analysis of Penetration Mechanics; Crashworthiness Engineering; Computer Modeling of Metal-Forming Processes; Thermal-Mechanical Modeling of Tungsten Arc Welding; Modeling Air Breakdown Induced by Electromagnetic Fields; Iterative Techniques for Solving Boltzmann's Equations for p-Type Semiconductors; Semiconductor Modeling; and Improved Numerical-Solution Techniques in Large-Scale Stress Analysis.

Innovating Method of Existing Mechanical Product Based on TRIZ Theory

NASA Astrophysics Data System (ADS)

Zhao, Cunyou; Shi, Dongyan; Wu, Han

Main way of product development is adaptive design and variant design based on existing product. In this paper, conceptual design frame and its flow model of innovating products is put forward through combining the methods of conceptual design and TRIZ theory. Process system model of innovating design that includes requirement analysis, total function analysis and decomposing, engineering problem analysis, finding solution of engineering problem and primarily design is constructed and this establishes the base for innovating design of existing product.

Nonstationary envelope process and first excursion probability.

NASA Technical Reports Server (NTRS)

Yang, J.-N.

1972-01-01

The definition of stationary random envelope proposed by Cramer and Leadbetter, is extended to the envelope of nonstationary random process possessing evolutionary power spectral densities. The density function, the joint density function, the moment function, and the crossing rate of a level of the nonstationary envelope process are derived. Based on the envelope statistics, approximate solutions to the first excursion probability of nonstationary random processes are obtained. In particular, applications of the first excursion probability to the earthquake engineering problems are demonstrated in detail.

Liga developer apparatus system

DOEpatents

Boehme, Dale R.; Bankert, Michelle A.; Christenson, Todd R.

2003-01-01

A system to fabricate precise, high aspect ratio polymeric molds by photolithograpic process is described. The molds for producing micro-scale parts from engineering materials by the LIGA process. The invention is a developer system for developing a PMMA photoresist having exposed patterns comprising features having both very small sizes, and very high aspect ratios. The developer system of the present invention comprises a developer tank, an intermediate rinse tank and a final rinse tank, each tank having a source of high frequency sonic agitation, temperature control, and continuous filtration. It has been found that by moving a patterned wafer, through a specific sequence of developer/rinse solutions, where an intermediate rinse solution completes development of those portions of the exposed resist left undeveloped after the development solution, by agitating the solutions with a source of high frequency sonic vibration, and by adjusting and closely controlling the temperatures and continuously filtering and recirculating these solutions, it is possible to maintain the kinetic dissolution of the exposed PMMA polymer as the rate limiting step.

Development of PVA/gelatin nanofibrous scaffolds for Tissue Engineering via electrospinning

NASA Astrophysics Data System (ADS)

Perez-Puyana, V.; Jiménez-Rosado, M.; Romero, A.; Guerrero, A.

2018-03-01

The electrospinning process is an emerging and relatively easy technique to prepare three-dimensional matrices with micro- and nanofibers. To achieve it, aqueous polymer solutions from synthetic or natural polymers are used. PVA was selected as polymer and gelatin because of its biocompatibility and biodegradability. A complete characterization of the polymeric solutions (density, surface tension, etc) was previously performed. Subsequently, a standard electrospinning process (15 kV, 0.4 ml h-1 and 10 cm) was carried out to obtain scaffolds. The influence of the polymer concentration and the protein addition was observed by performing FTIR analyses and studied by analyzing the water contact angle and SEM images.

The role of CFD in the design process

NASA Astrophysics Data System (ADS)

Jennions, Ian K.

1994-05-01

Over the last decade the role played by CFD codes in turbomachinery design has changed remarkably. While convergence/stability or even the existence of unique solutions was discussed fervently ten years ago, CFD codes now form a valuable part of an overall integrated design system and have caused us to re-think much of what we do. The geometric and physical complexities addressed have also evolved, as have the number of software houses competing with in-house developers to provide solutions to daily design problems. This paper reviews how GE Aircraft Engines (GEAE) uses CFD in the turbomachinery design process and examines many of the issues faced in successful code implementation.

USSR and Eastern Europe Scientific Abstracts, Engineering and Equipment, Number 34

DTIC Science & Technology

1977-09-07

indices of refraction and absorption and the optical homogeneity. Values of the indices of refraction and ab- sorption of IR glasses are presented...was found that cold plastic 20 deformation accelerates processes of breakdown of the gamma solid solution. The resistance to microplastic

System Maturity Indices for Decision Support in the Defense Acquisition Process

DTIC Science & Technology

2008-04-23

technologies, but was to be used as ontology for contracting support (Sadin, Povinelli , & Rosen, 1989), thus TRL does not address: A complete...via probabilistic solution discovery. Reliability Engineering & System Safety. In press. Sadin, S.R., Povinelli , F.P., & Rosen, R. (1989). The NASA

Global Situational Awareness with Free Tools

DTIC Science & Technology

2015-01-15

Client Technical Solutions • Software Engineering Measurement and Analysis • Architecture Practices • Product Line Practice • Team Software Process...multiple data sources • Snort (Snorby on Security Onion ) • Nagios • SharePoint RSS • Flow • Others • Leverage standard data formats • Keyhole Markup Language

Simulation of air pollution due to marine engines

NASA Astrophysics Data System (ADS)

Stan, L. C.

2017-08-01

This paperwork tried to simulate the combustion inside the marine engines using the newest computer methods and technologies with the result of a diverse and rich palette of solutions, extremely useful for the study and prediction of complex phenomena of the fuel combustion. The paperwork is contributing to the theoretical systematization of the area of interest bringing into attention a thoroughly inventory of the thermodynamic description of the phenomena which take place in the combustion process into the marine diesel engines; to the in depth multidimensional combustion models description along with the interdisciplinary phenomenology taking place in the combustion models; to the FEA (Finite Elements Method) modelling for the combustion chemistry in the nonpremixed mixtures approach considered too; the CFD (Computational Fluid Dynamics) model was issued for the combustion area and a rich palette of results interesting for any researcher of the process.

Large-scale and highly efficient synthesis of micro- and nano-fibers with controlled fiber morphology by centrifugal jet spinning for tissue regeneration

NASA Astrophysics Data System (ADS)

Ren, Liyun; Pandit, Vaibhav; Elkin, Joshua; Denman, Tyler; Cooper, James A.; Kotha, Shiva P.

2013-02-01

PLLA fibrous tissue scaffolds with controlled fiber nanoscale surface roughness are fabricated with a novel centrifugal jet spinning process. The centrifugal jet spinning technique is a highly efficient synthesis method for micron- to nano-sized fibers with a production rate up to 0.5 g min-1. During the centrifugal jet spinning process, a polymer solution jet is stretched by the centrifugal force of a rotating chamber. By engineering the rheological properties of the polymer solution, solvent evaporation rate and centrifugal force that are applied on the solution jet, polyvinylpyrrolidone (PVP) and poly(l-lactic acid) (PLLA) composite fibers with various diameters are fabricated. Viscosity measurements of polymer solutions allowed us to determine critical polymer chain entanglement limits that allow the generation of continuous fiber as opposed to beads or beaded fibers. Above a critical concentration at which polymer chains are partially or fully entangled, lower polymer concentrations and higher centrifugal forces resulted in thinner fibers. Etching of PVP from the PLLA-PVP composite fibers doped with increasing PVP concentrations yielded PLLA fibers with increasing nano-scale surface roughness and porosity, which increased the fiber hydrophilicity dramatically. Scanning electron micrographs of the etched composite fibers suggest that PVP and PLLA were co-contiguously phase separated within the composite fibers during spinning and nano-scale roughness features were created after the partial etching of PVP. To study the tissue regeneration efficacy of the engineered PLLA fiber matrix, human dermal fibroblasts are used to simulate partial skin graft. Fibers with increased PLLA surface roughness and porosity demonstrated a trend towards higher cell attachment and proliferation.PLLA fibrous tissue scaffolds with controlled fiber nanoscale surface roughness are fabricated with a novel centrifugal jet spinning process. The centrifugal jet spinning technique is a highly efficient synthesis method for micron- to nano-sized fibers with a production rate up to 0.5 g min-1. During the centrifugal jet spinning process, a polymer solution jet is stretched by the centrifugal force of a rotating chamber. By engineering the rheological properties of the polymer solution, solvent evaporation rate and centrifugal force that are applied on the solution jet, polyvinylpyrrolidone (PVP) and poly(l-lactic acid) (PLLA) composite fibers with various diameters are fabricated. Viscosity measurements of polymer solutions allowed us to determine critical polymer chain entanglement limits that allow the generation of continuous fiber as opposed to beads or beaded fibers. Above a critical concentration at which polymer chains are partially or fully entangled, lower polymer concentrations and higher centrifugal forces resulted in thinner fibers. Etching of PVP from the PLLA-PVP composite fibers doped with increasing PVP concentrations yielded PLLA fibers with increasing nano-scale surface roughness and porosity, which increased the fiber hydrophilicity dramatically. Scanning electron micrographs of the etched composite fibers suggest that PVP and PLLA were co-contiguously phase separated within the composite fibers during spinning and nano-scale roughness features were created after the partial etching of PVP. To study the tissue regeneration efficacy of the engineered PLLA fiber matrix, human dermal fibroblasts are used to simulate partial skin graft. Fibers with increased PLLA surface roughness and porosity demonstrated a trend towards higher cell attachment and proliferation. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr33423f

Contributions Regarding the Aircraft Nuclear Propulsion

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

Mitrica, Bogdan; Petre, Marian; Dima, Mihai Octavian

2010-01-21

The possibility to use a nuclear reactor for airplanes propulsion was investigated taking in to account 2 possible solutions: the direct cycle (where the fluid pass through the reactor's core) and the indirect cycle (where the fluid is passing through a heat exchanger). Taking in to account the radioprotection problems, the only realistic solution seems to be the indirect cycle, where the energy transfer should be performed by a heat exchanger that must work at very high speed of the fluid. The heat exchanger will replace the classical burning room. We had performed a more precise theoretical study for themore » nuclear jet engine regarding the performances of the nuclear reactor, of the heat exchanger and of the jet engine. It was taken in to account that in the moment when the burning room is replaced by a heat exchanger, a new model for gasodynamic process from the engine must be performed. Studies regarding the high flow speed heat transfer were performed.« less

Influence of engineered interfaces on residual stresses and mechanical response in metal matrix composites

NASA Technical Reports Server (NTRS)

Arnold, Steven M.; Wilt, Thomas E.

1992-01-01

Because of the inherent coefficient of thermal expansion (CTE) mismatch between fiber and matrix within metal and intermetallic matrix composite systems, high residual stresses can develop under various thermal loading conditions. These conditions include cooling from processing temperature to room temperature as well as subsequent thermal cycling. As a result of these stresses, within certain composite systems, radial, circumferential, and/or longitudinal cracks have been observed to form at the fiber matrix interface region. A number of potential solutions for reducing this thermally induced residual stress field have been proposed recently. Examples of some potential solutions are high CTE fibers, fiber preheating, thermal anneal treatments, and an engineered interface. Here the focus is on designing an interface (by using a compensating/compliant layer concept) to reduce or eliminate the thermal residual stress field and, therefore, the initiation and propagation of cracks developed during thermal loading. Furthermore, the impact of the engineered interface on the composite's mechanical response when subjected to isothermal mechanical load histories is examined.

Activist engineering: changing engineering practice by deploying praxis.

PubMed

Karwat, Darshan M A; Eagle, Walter E; Wooldridge, Margaret S; Princen, Thomas E

2015-02-01

In this paper, we reflect on current notions of engineering practice by examining some of the motives for engineered solutions to the problem of climate change. We draw on fields such as science and technology studies, the philosophy of technology, and environmental ethics to highlight how dominant notions of apoliticism and ahistoricity are ingrained in contemporary engineering practice. We argue that a solely technological response to climate change does not question the social, political, and cultural tenet of infinite material growth, one of the root causes of climate change. In response to the contemporary engineering practice, we define an activist engineer as someone who not only can provide specific engineered solutions, but who also steps back from their work and tackles the question, What is the real problem and does this problem "require" an engineering intervention? Solving complex problems like climate change requires radical cultural change, and a significant obstacle is educating engineers about how to conceive of and create "authentic alternatives," that is, solutions that differ from the paradigm of "technologically improving" our way out of problems. As a means to realize radically new solutions, we investigate how engineers might (re)deploy the concept of praxis, which raises awareness in engineers of the inherent politics of technological design. Praxis empowers engineers with a more comprehensive understanding of problems, and thus transforms technologies, when appropriate, into more socially just and ecologically sensitive interventions. Most importantly, praxis also raises a radical alternative rarely considered-not "engineering a solution." Activist engineering offers a contrasting method to contemporary engineering practice and leads toward social justice and ecological protection through problem solving by asking not, How will we technologize our way out of the problems we face? but instead, What really needs to be done?

Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces.

PubMed

Boys, Alexander J; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J; Estroff, Lara A

2017-09-01

Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors.

Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

PubMed Central

Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

2017-01-01

Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

Computational System For Rapid CFD Analysis In Engineering

NASA Technical Reports Server (NTRS)

Barson, Steven L.; Ascoli, Edward P.; Decroix, Michelle E.; Sindir, Munir M.

1995-01-01

Computational system comprising modular hardware and software sub-systems developed to accelerate and facilitate use of techniques of computational fluid dynamics (CFD) in engineering environment. Addresses integration of all aspects of CFD analysis process, including definition of hardware surfaces, generation of computational grids, CFD flow solution, and postprocessing. Incorporates interfaces for integration of all hardware and software tools needed to perform complete CFD analysis. Includes tools for efficient definition of flow geometry, generation of computational grids, computation of flows on grids, and postprocessing of flow data. System accepts geometric input from any of three basic sources: computer-aided design (CAD), computer-aided engineering (CAE), or definition by user.

Using concepts from biology to improve problem-solving methods

NASA Astrophysics Data System (ADS)

Goodman, Erik D.; Rothwell, Edward J.; Averill, Ronald C.

2011-06-01

Observing nature has been a cornerstone of engineering design. Today, engineers look not only at finished products, but imitate the evolutionary process by which highly optimized artifacts have appeared in nature. Evolutionary computation began by capturing only the simplest ideas of evolution, but today, researchers study natural evolution and incorporate an increasing number of concepts in order to evolve solutions to complex engineering problems. At the new BEACON Center for the Study of Evolution in Action, studies in the lab and field and in silico are laying the groundwork for new tools for evolutionary engineering design. This paper, which accompanies a keynote address, describes various steps in development and application of evolutionary computation, particularly as regards sensor design, and sets the stage for future advances.

Mathematical simulation of the drying of suspensions and colloidal solutions by their depressurization

NASA Astrophysics Data System (ADS)

Lashkov, V. A.; Levashko, E. I.; Safin, R. G.

2006-05-01

The heat and mass transfer in the process of drying of high-humidity materials by their depressurization has been investigated. The results of experimental investigation and mathematical simulation of the indicated process are presented. They allow one to determine the regularities of this process and predict the quality of the finished product. A technological scheme and an engineering procedure for calculating the drying of the liquid base of a soap are presented.

Evaluating a digital ship design tool prototype: Designers' perceptions of novel ergonomics software.

PubMed

Mallam, Steven C; Lundh, Monica; MacKinnon, Scott N

2017-03-01

Computer-aided solutions are essential for naval architects to manage and optimize technical complexities when developing a ship's design. Although there are an array of software solutions aimed to optimize the human element in design, practical ergonomics methodologies and technological solutions have struggled to gain widespread application in ship design processes. This paper explores how a new ergonomics technology is perceived by naval architecture students using a mixed-methods framework. Thirteen Naval Architecture and Ocean Engineering Masters students participated in the study. Overall, results found participants perceived the software and its embedded ergonomics tools to benefit their design work, increasing their empathy and ability to understand the work environment and work demands end-users face. However, participant's questioned if ergonomics could be practically and efficiently implemented under real-world project constraints. This revealed underlying social biases and a fundamental lack of understanding in engineering postgraduate students regarding applied ergonomics in naval architecture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of processing parameters on pore structure of 3D porous chitosan-alginate polyelectrolyte complex scaffolds.

PubMed

Florczyk, Stephen J; Kim, Dae-Joon; Wood, David L; Zhang, Miqin

2011-09-15

Fabrication of porous polymeric scaffolds with controlled structure can be challenging. In this study, we investigated the influence of key experimental parameters on the structures and mechanical properties of resultant porous chitosan-alginate (CA) polyelectrolyte complex (PEC) scaffolds, and on proliferation of MG-63 osteoblast-like cells, targeted at bone tissue engineering. We demonstrated that the porous structure is largely affected by the solution viscosity, which can be regulated by the acetic acid and alginate concentrations. We found that the CA PEC solutions with viscosity below 300 Pa.s yielded scaffolds of uniform pore structure and that more neutral pH promoted more complete complexation of chitosan and alginate, yielding stiffer scaffolds. CA PEC scaffolds produced from solutions with viscosities below 300 Pa.s also showed enhanced cell proliferation compared with other samples. By controlling the key experimental parameters identified in this study, CA PEC scaffolds of different structures can be made to suit various tissue engineering applications. Copyright © 2011 Wiley Periodicals, Inc.

Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine

PubMed Central

Qasim, Saad B.; Khurshid, Zohaib; Shah, Altaf H.; Husain, Shehriar; Rehman, Ihtesham Ur

2018-01-01

Electrospinning has been used for decades to generate nano-fibres via an electrically charged jet of polymer solution. This process is established on a spinning technique, using electrostatic forces to produce fine fibres from polymer solutions. Amongst, the electrospinning of available biopolymers (silk, cellulose, collagen, gelatine and hyaluronic acid), chitosan (CH) has shown a favourable outcome for tissue regeneration applications. The aim of the current review is to assess the current literature about electrospinning chitosan and its composite formulations for creating fibres in combination with other natural polymers to be employed in tissue engineering. In addition, various polymers blended with chitosan for electrospinning have been discussed in terms of their potential biomedical applications. The review shows that evidence exists in support of the favourable properties and biocompatibility of chitosan electrospun composite biomaterials for a range of applications. However, further research and in vivo studies are required to translate these materials from the laboratory to clinical applications. PMID:29385727

Modeling nuclear processes by Simulink

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

Rashid, Nahrul Khair Alang Md, E-mail: nahrul@iium.edu.my

2015-04-29

Modelling and simulation are essential parts in the study of dynamic systems behaviours. In nuclear engineering, modelling and simulation are important to assess the expected results of an experiment before the actual experiment is conducted or in the design of nuclear facilities. In education, modelling can give insight into the dynamic of systems and processes. Most nuclear processes can be described by ordinary or partial differential equations. Efforts expended to solve the equations using analytical or numerical solutions consume time and distract attention from the objectives of modelling itself. This paper presents the use of Simulink, a MATLAB toolbox softwaremore » that is widely used in control engineering, as a modelling platform for the study of nuclear processes including nuclear reactor behaviours. Starting from the describing equations, Simulink models for heat transfer, radionuclide decay process, delayed neutrons effect, reactor point kinetic equations with delayed neutron groups, and the effect of temperature feedback are used as examples.« less

Engineering the evolution of self-organizing behaviors in swarm robotics: a case study.

PubMed

Trianni, Vito; Nolfi, Stefano

2011-01-01

Evolutionary robotics (ER) is a powerful approach for the automatic synthesis of robot controllers, as it requires little a priori knowledge about the problem to be solved in order to obtain good solutions. This is particularly true for collective and swarm robotics, in which the desired behavior of the group is an indirect result of the control and communication rules followed by each individual. However, the experimenter must make several arbitrary choices in setting up the evolutionary process, in order to define the correct selective pressures that can lead to the desired results. In some cases, only a deep understanding of the obtained results can point to the critical aspects that constrain the system, which can be later modified in order to re-engineer the evolutionary process towards better solutions. In this article, we discuss the problem of engineering the evolutionary machinery that can lead to the desired result in the swarm robotics context. We also present a case study about self-organizing synchronization in a swarm of robots, in which some arbitrarily chosen properties of the communication system hinder the scalability of the behavior to large groups. We show that by modifying the communication system, artificial evolution can synthesize behaviors that scale properly with the group size.

An Extended Combustion Model for the Aircraft Turbojet Engine

NASA Astrophysics Data System (ADS)

Rotaru, Constantin; Andres-Mihăilă, Mihai; Matei, Pericle Gabriel

2014-08-01

The paper consists in modelling and simulation of the combustion in a turbojet engine in order to find optimal characteristics of the burning process and the optimal shape of combustion chambers. The main focus of this paper is to find a new configuration of the aircraft engine combustion chambers, namely an engine with two main combustion chambers, one on the same position like in classical configuration, between compressor and turbine and the other, placed behind the turbine but not performing the role of the afterburning. This constructive solution could allow a lower engine rotational speed, a lower temperature in front of the first stage of the turbine and the possibility to increase the turbine pressure ratio by extracting the flow stream after turbine in the inner nozzle. Also, a higher thermodynamic cycle efficiency and thrust in comparison to traditional constant-pressure combustion gas turbine engines could be obtained.

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.

A Template-Based Short Course Concept on Android Application Development

ERIC Educational Resources Information Center

Akopian, David; Melkonyan, Arsen; Golgani, Santosh C.; Yuen, Timothy T.; Saygin, Can

2013-01-01

Smartphones are a common accessory to provide rich user experience due to superior memory, advanced software-hardware support, fast processing, and multimedia capabilities. Responding to this trend, advanced engineering systems tend to integrate mobile devices with their solutions to facilitate usability. With many young students showing interest…

Teaching the Concept of Gibbs Energy Minimization through Its Application to Phase-Equilibrium Calculation

ERIC Educational Resources Information Center

Privat, Romain; Jaubert, Jean-Noe¨l; Berger, Etienne; Coniglio, Lucie; Lemaitre, Ce´cile; Meimaroglou, Dimitrios; Warth, Vale´rie

2016-01-01

Robust and fast methods for chemical or multiphase equilibrium calculation are routinely needed by chemical-process engineers working on sizing or simulation aspects. Yet, while industrial applications essentially require calculation tools capable of discriminating between stable and nonstable states and converging to nontrivial solutions,…

The causes of unstable engine idle speed and their solutions

NASA Astrophysics Data System (ADS)

Yang, Fan

2018-06-01

There are many types of engines. The most commonly used engine for automobiles is the internal combustion engine. Internal combustion engines use a four-stroke combustion cycle to convert gasoline into motion. The four-stroke approach, also known as the "Ototo cycle," commemorates Nicklaus Otto, who invented it in 1867. The working cycle of a four-stroke engine consists of four piston strokes, ie, intake stroke, compression stroke, power stroke, and exhaust stroke. This article focuses on the cause of the instability of the four-stroke engine and its solution. There are many reasons for the instability of the engine, so this article will be divided into four areas: intake system, fuel system, ignition system and mechanical structure. Based on the above reasons, the corresponding solution is proposed.

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

Townsend, D.W.; Linnhoff, B.

In Part I, criteria for heat engine and heat pump placement in chemical process networks were derived, based on the ''temperature interval'' (T.I) analysis of the heat exchanger network problem. Using these criteria, this paper gives a method for identifying the best outline design for any combined system of chemical process, heat engines, and heat pumps. The method eliminates inferior alternatives early, and positively leads on to the most appropriate solution. A graphical procedure based on the T.I. analysis forms the heart of the approach, and the calculations involved are simple enough to be carried out on, say, a programmablemore » calculator. Application to a case study is demonstrated. Optimization methods based on this procedure are currently under research.« less

Software life cycle methodologies and environments

NASA Technical Reports Server (NTRS)

Fridge, Ernest

1991-01-01

Products of this project will significantly improve the quality and productivity of Space Station Freedom Program software processes by: improving software reliability and safety; and broadening the range of problems that can be solved with computational solutions. Projects brings in Computer Aided Software Engineering (CASE) technology for: Environments such as Engineering Script Language/Parts Composition System (ESL/PCS) application generator, Intelligent User Interface for cost avoidance in setting up operational computer runs, Framework programmable platform for defining process and software development work flow control, Process for bringing CASE technology into an organization's culture, and CLIPS/CLIPS Ada language for developing expert systems; and methodologies such as Method for developing fault tolerant, distributed systems and a method for developing systems for common sense reasoning and for solving expert systems problems when only approximate truths are known.

User-centered requirements engineering in health information systems: a study in the hemophilia field.

PubMed

Teixeira, Leonor; Ferreira, Carlos; Santos, Beatriz Sousa

2012-06-01

The use of sophisticated information and communication technologies (ICTs) in the health care domain is a way to improve the quality of services. However, there are also hazards associated with the introduction of ICTs in this domain and a great number of projects have failed due to the lack of systematic consideration of human and other non-technology issues throughout the design or implementation process, particularly in the requirements engineering process. This paper presents the methodological approach followed in the design process of a web-based information system (WbIS) for managing the clinical information in hemophilia care, which integrates the values and practices of user-centered design (UCD) activities into the principles of software engineering, particularly in the phase of requirements engineering (RE). This process followed a paradigm that combines a grounded theory for data collection with an evolutionary design based on constant development and refinement of the generic domain model using three well-known methodological approaches: (a) object-oriented system analysis; (b) task analysis; and, (c) prototyping, in a triangulation work. This approach seems to be a good solution for the requirements engineering process in this particular case of the health care domain, since the inherent weaknesses of individual methods are reduced, and emergent requirements are easier to elicit. Moreover, the requirements triangulation matrix gives the opportunity to look across the results of all used methods and decide what requirements are critical for the system success. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Techniques for Type I Collagen Organization

NASA Astrophysics Data System (ADS)

Anderson-Jackson, LaTecia Diamond

Tissue Engineering is a process in which cells, engineering, and material methods are used in amalgamation to improve biological functions. The purpose of tissue engineering is to develop alternative solutions to treat or cure tissues and organs that have been severely altered or damaged by diseases, congenital defects, trauma, or cancer. One of the most common and most promising biological materials for tissue engineering to develop scaffolds is Type I collagen. A major challenge in biomedical research is aligning Type I collagen to mimic biological structures, such as ligaments, tendons, bones, and other hierarchal aligned structures within the human body. The intent of this research is to examine possible techniques for organizing Type I collagen and to assess which of the techniques is effective for potential biological applications. The techniques used in this research to organize collagen are soft lithography with solution-assisted sonication embossing, directional freezing, and direct poling. The final concentration used for both soft lithography with solution-assisted sonication embossing and direct poling was 1 mg/ml, whereas for directional freezing the final concentration varied between 4mg/ml, 2mg/ml, and 1 mg/ml. These techniques were characterized using the Atomic Force Microscope (AFM) and Helium Ion Microscope (HIM). In this study, we have found that out of the three techniques, the soft lithography and directional freezing techniques have been successful in organizing collagen in a particular pattern, but not alignment. We concluded alignment may be dependent on the pH of collagen and the amount of acetic acid used in collagen solution. However, experiments are still being conducted to optimize all three techniques to align collagen in a unidirectional arrangement.

The Tool for Designing Engineering Systems Using a New Optimization Method Based on a Stochastic Process

NASA Astrophysics Data System (ADS)

Yoshida, Hiroaki; Yamaguchi, Katsuhito; Ishikawa, Yoshio

The conventional optimization methods were based on a deterministic approach, since their purpose is to find out an exact solution. However, these methods have initial condition dependence and risk of falling into local solution. In this paper, we propose a new optimization method based on a concept of path integral method used in quantum mechanics. The method obtains a solutions as an expected value (stochastic average) using a stochastic process. The advantages of this method are not to be affected by initial conditions and not to need techniques based on experiences. We applied the new optimization method to a design of the hang glider. In this problem, not only the hang glider design but also its flight trajectory were optimized. The numerical calculation results showed that the method has a sufficient performance.

Development of an in-process UV-crosslinked, electrospun PCL/aPLA-co-TMC composite polymer for tubular tissue engineering applications.

PubMed

Stefani, I; Cooper-White, J J

2016-05-01

Cardiovascular diseases remain the largest cause of death worldwide, and half of these deaths are the result of failure of the vascular system. Tissue engineering promises to provide new, and potentially more effective therapeutic strategies to replace damaged or degenerated vessels with functional vessels. However, these engineered vessels have substantial performance criteria, including vessel-like tubular shape, structure and mechanical property slate. Further, whether implanted without or with prior in vitro culture, such tubular scaffolds must provide a suitable environment for cell adhesion and growth and be of sufficient porosity to permit cell colonization. This study investigates the fabrication of slowly degradable, composite tubular polymer scaffolds made from polycaprolactone (PCL) and acrylated l-lactide-co-trimethylene carbonate (aPLA-co-TMC). The addition of acrylate groups permits the 'in-process' formation of crosslinks between aPLA-co-TMC chains during electrospinning of the composite system, exemplifying a novel process to produce multicomponent, elastomeric electrospun polymer scaffolds. Although PCL and aPLA-co-TMC were miscible in a co-solvent, a criteria for electrospinning, due to thermodynamic incompatibility of the two polymers as melts, solvent evaporation during electrospinning drove phase separation of these two systems, producing 'core-shell' fibres, with the core being composed of PCL, and the shell of crosslinked elastomeric aPLA-co-TMC. The resulting elastic fibrous scaffolds displayed burst pressures and suture retention strengths comparable with human arteries. Cytocompatibility testing with human mesenchymal stem cells confirmed adhesion to, and proliferation on the three-dimensional fibrous network, as well as alignment with highly-organized fibres. This new processing methodology and resulting mechanically-robust composite scaffolds hold significant promise for tubular tissue engineering applications. Autologous small diameter blood vessel grafts are unsuitable solutions for vessel repair. Engineered solutions such as tubular biomaterial scaffolds however have substantial performance criteria to meet, including vessel-like tubular shape, structure and mechanical property slate. We detail herein an innovative methodology to co-electrospin and 'in-process' crosslink composite mixtures of Poly(caprolactone) and a newly synthesised acrylated-Poly(lactide-co-trimethylene-carbonate) to create elastomeric, core-shell nanofibrous porous scaffolds in a one-step process. This novel composite system can be used to make aligned scaffolds that encourage stem cell adhesion, growth and morphological control, and produce robust tubular scaffolds of tunable internal diameter and wall thickness that possess mechanical properties approaching those of native vessels, ideal for future applications in the field of vessel tissue engineering. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Large-Scale Bi-Level Strain Design Approaches and Mixed-Integer Programming Solution Techniques

PubMed Central

Kim, Joonhoon; Reed, Jennifer L.; Maravelias, Christos T.

2011-01-01

The use of computational models in metabolic engineering has been increasing as more genome-scale metabolic models and computational approaches become available. Various computational approaches have been developed to predict how genetic perturbations affect metabolic behavior at a systems level, and have been successfully used to engineer microbial strains with improved primary or secondary metabolite production. However, identification of metabolic engineering strategies involving a large number of perturbations is currently limited by computational resources due to the size of genome-scale models and the combinatorial nature of the problem. In this study, we present (i) two new bi-level strain design approaches using mixed-integer programming (MIP), and (ii) general solution techniques that improve the performance of MIP-based bi-level approaches. The first approach (SimOptStrain) simultaneously considers gene deletion and non-native reaction addition, while the second approach (BiMOMA) uses minimization of metabolic adjustment to predict knockout behavior in a MIP-based bi-level problem for the first time. Our general MIP solution techniques significantly reduced the CPU times needed to find optimal strategies when applied to an existing strain design approach (OptORF) (e.g., from ∼10 days to ∼5 minutes for metabolic engineering strategies with 4 gene deletions), and identified strategies for producing compounds where previous studies could not (e.g., malate and serine). Additionally, we found novel strategies using SimOptStrain with higher predicted production levels (for succinate and glycerol) than could have been found using an existing approach that considers network additions and deletions in sequential steps rather than simultaneously. Finally, using BiMOMA we found novel strategies involving large numbers of modifications (for pyruvate and glutamate), which sequential search and genetic algorithms were unable to find. The approaches and solution techniques developed here will facilitate the strain design process and extend the scope of its application to metabolic engineering. PMID:21949695

Large-scale bi-level strain design approaches and mixed-integer programming solution techniques.

PubMed

Kim, Joonhoon; Reed, Jennifer L; Maravelias, Christos T

2011-01-01

The use of computational models in metabolic engineering has been increasing as more genome-scale metabolic models and computational approaches become available. Various computational approaches have been developed to predict how genetic perturbations affect metabolic behavior at a systems level, and have been successfully used to engineer microbial strains with improved primary or secondary metabolite production. However, identification of metabolic engineering strategies involving a large number of perturbations is currently limited by computational resources due to the size of genome-scale models and the combinatorial nature of the problem. In this study, we present (i) two new bi-level strain design approaches using mixed-integer programming (MIP), and (ii) general solution techniques that improve the performance of MIP-based bi-level approaches. The first approach (SimOptStrain) simultaneously considers gene deletion and non-native reaction addition, while the second approach (BiMOMA) uses minimization of metabolic adjustment to predict knockout behavior in a MIP-based bi-level problem for the first time. Our general MIP solution techniques significantly reduced the CPU times needed to find optimal strategies when applied to an existing strain design approach (OptORF) (e.g., from ∼10 days to ∼5 minutes for metabolic engineering strategies with 4 gene deletions), and identified strategies for producing compounds where previous studies could not (e.g., malate and serine). Additionally, we found novel strategies using SimOptStrain with higher predicted production levels (for succinate and glycerol) than could have been found using an existing approach that considers network additions and deletions in sequential steps rather than simultaneously. Finally, using BiMOMA we found novel strategies involving large numbers of modifications (for pyruvate and glutamate), which sequential search and genetic algorithms were unable to find. The approaches and solution techniques developed here will facilitate the strain design process and extend the scope of its application to metabolic engineering.

An evaluation of Admedus' tissue engineering process-treated (ADAPT) bovine pericardium patch (CardioCel) for the repair of cardiac and vascular defects.

PubMed

Strange, Geoff; Brizard, Christian; Karl, Tom R; Neethling, Leon

2015-03-01

Tissue engineers have been seeking the 'Holy Grail' solution to calcification and cytotoxicity of implanted tissue for decades. Tissues with all of the desired qualities for surgical repair of congenital heart disease (CHD) are lacking. An anti-calcification tissue engineering process (ADAPT TEP) has been developed and applied to bovine pericardium (BP) tissue (CardioCel, AdmedusRegen Pty Ltd, Perth, WA, Australia) to eliminate cytotoxicity, improve resistance to acute and chronic inflammation, reduce calcification and facilitate controlled tissue remodeling. Clinical data in pediatric patients, and additional pre-market authorized prescriber data demonstrate that CardioCel performs extremely well in the short term and is safe and effective for a range of congenital heart deformations. These data are supported by animal studies which have shown no more than normal physiologic levels of calcification, with good durability, biocompatibility and controlled healing.

Integrated system for automated financial document processing

NASA Astrophysics Data System (ADS)

Hassanein, Khaled S.; Wesolkowski, Slawo; Higgins, Ray; Crabtree, Ralph; Peng, Antai

1997-02-01

A system was developed that integrates intelligent document analysis with multiple character/numeral recognition engines in order to achieve high accuracy automated financial document processing. In this system, images are accepted in both their grayscale and binary formats. A document analysis module starts by extracting essential features from the document to help identify its type (e.g. personal check, business check, etc.). These features are also utilized to conduct a full analysis of the image to determine the location of interesting zones such as the courtesy amount and the legal amount. These fields are then made available to several recognition knowledge sources such as courtesy amount recognition engines and legal amount recognition engines through a blackboard architecture. This architecture allows all the available knowledge sources to contribute incrementally and opportunistically to the solution of the given recognition query. Performance results on a test set of machine printed business checks using the integrated system are also reported.

Bicarbonate of soda paint stripping process validation and material characterization

NASA Technical Reports Server (NTRS)

Haas, Michael N.

1995-01-01

The Aircraft Production Division at San Antonio Air Logistics Center has conducted extensive investigation into the replacement of hazardous chemicals in aircraft component cleaning, degreasing, and depainting. One of the most viable solutions is process substitution utilizing abrasive techniques. SA-ALC has incorporated the use of Bicarbonate of Soda Blasting as one such substitution. Previous utilization of methylene chloride based chemical strippers and carbon removal agents has been replaced by a walk-in blast booth in which we remove carbon from engine nozzles and various gas turbine engine parts, depaint cowlings, and perform various other functions on a variety of parts. Prior to implementation of this new process, validation of the process was performed, and materials and waste stream characterization studies were conducted. These characterization studies examined the effects of the blasting process on the integrity of the thin-skinned aluminum substrates, the effects of the process on both air emissions and effluent disposal, and the effects on the personnel exposed to the process.

Collaborative-Large scale Engineering Assessment Networks for Environmental Research: The Overview

NASA Astrophysics Data System (ADS)

Moo-Young, H.

2004-05-01

A networked infrastructure for engineering solutions and policy alternatives is necessary to assess, manage, and protect complex, anthropogenic ally stressed environmental resources effectively. Reductionist and discrete disciplinary methodologies are no longer adequate to evaluate and model complex environmental systems and anthropogenic stresses. While the reductonist approach provides important information regarding individual mechanisms, it cannot provide complete information about how multiple processes are related. Therefore, it is not possible to make accurate predictions about system responses to engineering interventions and the effectiveness of policy options. For example, experts cannot agree on best management strategies for contaminated sediments in riverine and estuarine systems. This is due, in part to the fact that existing models do not accurately capture integrated system dynamics. In addition, infrastructure is not available for investigators to exchange and archive data, to collaborate on new investigative methods, and to synthesize these results to develop engineering solutions and policy alternatives. Our vision for the future is to create a network comprising field facilities and a collaboration of engineers, scientists, policy makers, and community groups. This will allow integration across disciplines, across different temporal and spatial scales, surface and subsurface geographies, and air sheds and watersheds. Benefits include fast response to changes in system health, real-time decision making, and continuous data collection that can be used to anticipate future problems, and to develop sound engineering solutions and management decisions. CLEANER encompasses four general aspects: 1) A Network of environmental field facilities instrumented for the acquisition and analysis of environmental data; 2) A Virtual Repository of Data and information technology for engineering modeling, analysis and visualization of data, i.e. an environmental cyber-infrastructure; 3) A Mechanism for multidisciplinary research and education activities designed to exploit the output of the instrumented sites and networked information technology, to formulate engineering and policy options directed toward the protection, remediation, and restoration of stressed environments and sustainability of environmental resources; and 4) A Collaboration among engineers, natural and social scientists, educators, policy makers, industry, non-governmental organizations, the public, and other stakeholders.

Ventilation equations for improved exothermic process control.

PubMed

McKernan, John L; Ellenbecker, Michael J

2007-04-01

Exothermic or heated processes create potentially unsafe work environments for an estimated 5-10 million American workers each year. Excessive heat and process contaminants have the potential to cause acute health effects such as heat stroke, and chronic effects such as manganism in welders. Although millions of workers are exposed to exothermic processes, insufficient attention has been given to continuously improving engineering technologies for these processes to provide effective and efficient control. Currently there is no specific occupational standard established by OSHA regarding exposure to heat from exothermic processes, therefore it is important to investigate techniques that can mitigate known and potential adverse occupational health effects. The current understanding of engineering controls for exothermic processes is primarily based on a book chapter written by W. C. L. Hemeon in 1955. Improvements in heat transfer and meteorological theory necessary to design improved process controls have occurred since this time. The research presented involved a review of the physical properties, heat transfer and meteorological theories governing buoyant air flow created by exothermic processes. These properties and theories were used to identify parameters and develop equations required for the determination of buoyant volumetric flow to assist in improving ventilation controls. Goals of this research were to develop and describe a new (i.e. proposed) flow equation, and compare it to currently accepted ones by Hemeon and the American Conference of Governmental Industrial Hygienists (ACGIH). Numerical assessments were conducted to compare solutions from the proposed equations for plume area, mean velocity and flow to those from the ACGIH and Hemeon. Parameters were varied for the dependent variables and solutions from the proposed, ACGIH, and Hemeon equations for plume area, mean velocity and flow were analyzed using a randomized complete block statistical design (ANOVA). Results indicate that the proposed plume mean velocity equation provides significantly greater means than either the ACGIH or Hemeon equations throughout the range of parameters investigated. The proposed equations for plume area and flow also provide significantly greater means than either the ACGIH or Hemeon equations at distances >1 m above exothermic processes. With an accurate solution for the total volumetric flow, ventilation engineers and practicing industrial hygienists are equipped with the necessary information to design and size hoods, as well as place them at an optimal distance from the source to provide adequate control of the rising plume. The equations developed will allow researchers and practitioners to determine the critical control parameters for exothermic processes, such as the exhaust flow necessary to improve efficacy and efficiency, while ensuring adequate worker protection.

How NASA Expanded its Innovation Framework to Find New Solutions to Old Problems

NASA Technical Reports Server (NTRS)

Davis, Jeffrey R.

2010-01-01

A radio frequency engineer from rural New Hampshire contributed the best solution to a public challenge issued by NASA's Space Life Sciences Directorate. This is a clear example of what Aneesh Chopra, the US Federal Chief Technology Officer, describes as the notion that in our society, knowledge is widely dispersed. And if it s widely dispersed, how do we capture the insights from the American people?" Chopra later said, to a live audience at the 2010 Rethinking Government event: "A semi-retired radio frequency engineer was able to share his idea about how to solve this problem, and it so blew away other ideas that NASA said it exceeded their requirements! No complicated RFP, the need for lobbyists, some convoluted processes, etc. Just a smart person who was paid a modest fee for his insight."

Fabrication of Biopolymer Nanofibers of Hyaluronic Acid via Electrospinning

NASA Astrophysics Data System (ADS)

Young, Denice; Queen, Hailey; Krause, Wendy

2006-03-01

Electrospinning is a novel technology that uses an electric field to form fibrous materials from a polymer solution. Unlike traditional spinning techniques, electrospinning can produce fibers on the order of 100 nm that can be utilized in applications where nanoscale fibers are necessary for successful implementation, including tissue engineering. Hyaluronic acid (HA) is a widely used biopolymer found in the extracellular matrix and currently marketed in medical applications for joint lubrications and tissue engineering. The high viscosity and surface tension of HA make it an unlikely candidate for electrospinning processes as viscosity is an important parameter in successful electrospinning. To promote HA fiber formation by electrospinning, the effects of salt (NaCl), which is used to reduce the viscosity of aqueous HA solutions; molecular weight of the HA; and an additional biocompatible polymer (e.g., PEO) are under investigation.

Toward a user-driven approach to radiology software solutions: putting the wag back in the dog.

PubMed

Morgan, Matthew; Mates, Jonathan; Chang, Paul

2006-09-01

The relationship between healthcare providers and the software industry is evolving. In many cases, industry's traditional, market-driven model is failing to meet the increasingly sophisticated and appropriately individualized needs of providers. Advances in both technology infrastructure and development methodologies have set the stage for the transition from a vendor-driven to a more user-driven process of solution engineering. To make this transition, providers must take an active role in the development process and vendors must provide flexible frameworks on which to build. Only then can the provider/vendor relationship mature from a purchaser/supplier to a codesigner/partner model, where true insight and innovation can occur.

Pursuing High-Mobility n-Type Organic Semiconductors by Combination of "Molecule-Framework" and "Side-Chain" Engineering.

PubMed

Zhang, Cheng; Zang, Yaping; Zhang, Fengjiao; Diao, Ying; McNeill, Christopher R; Di, Chong-An; Zhu, Xiaozhang; Zhu, Daoben

2016-10-01

"Molecule-framework" and "side-chain" engineering is powerful for the design of high-performance organic semiconductors. Based on 2DQTTs, the relationship between molecular structure, film microstructure, and charge-transport property in organic thin-film transistors (OTFTs) is studied. 2DQTT-o-B exhibits outstanding electron mobilities of 5.2 cm 2 V -1 s -1 , which is a record for air-stable solution-processable n-channel small-molecule OTFTs to date. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Systems engineering and integration of control centers in support of multiple programs. [ground control for STS payloads and unmanned vehicles

NASA Technical Reports Server (NTRS)

Miller, David N.

1989-01-01

The NASA Johnson Space Center's new Multiprogram Control Center (MPCC) addresses the control requirements of complex STS payloads as well as unmanned vehicles. An account is given of the relationship of the MPCC to the STS Mission Control Center, with a view to significant difficulties that may be encountered and solutions thus far devised for generic problems. Examples of MPCC workstation applications encompass telemetry decommutation, engineering unit conversion, data-base management, trajectory processing, and flight design.

The Design of a Practical Enterprise Safety Management System

NASA Astrophysics Data System (ADS)

Gabbar, Hossam A.; Suzuki, Kazuhiko

This book presents design guidelines and implementation approaches for enterprise safety management system as integrated within enterprise integrated systems. It shows new model-based safety management where process design automation is integrated with enterprise business functions and components. It proposes new system engineering approach addressed to new generation chemical industry. It will help both the undergraduate and professional readers to build basic knowledge about issues and problems of designing practical enterprise safety management system, while presenting in clear way, the system and information engineering practices to design enterprise integrated solution.

The Role of Computers in Research and Development at Langley Research Center

NASA Technical Reports Server (NTRS)

Wieseman, Carol D. (Compiler)

1994-01-01

This document is a compilation of presentations given at a workshop on the role cf computers in research and development at the Langley Research Center. The objectives of the workshop were to inform the Langley Research Center community of the current software systems and software practices in use at Langley. The workshop was organized in 10 sessions: Software Engineering; Software Engineering Standards, methods, and CASE tools; Solutions of Equations; Automatic Differentiation; Mosaic and the World Wide Web; Graphics and Image Processing; System Design Integration; CAE Tools; Languages; and Advanced Topics.

Materials Science Laboratory

NASA Technical Reports Server (NTRS)

Jackson, Dionne

2005-01-01

The NASA Materials Science Laboratory (MSL) provides science and engineering services to NASA and Contractor customers at KSC, including those working for the Space Shuttle. International Space Station. and Launch Services Programs. These services include: (1) Independent/unbiased failure analysis (2) Support to Accident/Mishap Investigation Boards (3) Materials testing and evaluation (4) Materials and Processes (M&P) engineering consultation (5) Metrology (6) Chemical analysis (including ID of unknown materials) (7) Mechanical design and fabrication We provide unique solutions to unusual and urgent problems associated with aerospace flight hardware, ground support equipment and related facilities.

An Image Retrieval and Processing Expert System for the World Wide Web

NASA Technical Reports Server (NTRS)

Rodriguez, Ricardo; Rondon, Angelica; Bruno, Maria I.; Vasquez, Ramon

1998-01-01

This paper presents a system that is being developed in the Laboratory of Applied Remote Sensing and Image Processing at the University of P.R. at Mayaguez. It describes the components that constitute its architecture. The main elements are: a Data Warehouse, an Image Processing Engine, and an Expert System. Together, they provide a complete solution to researchers from different fields that make use of images in their investigations. Also, since it is available to the World Wide Web, it provides remote access and processing of images.

Tool and Fixture Design

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

Graham, Mark W.

2015-07-28

In a manufacturing process, a need is identified and a product is created to fill this need. While design and engineering of the final product is important, the tools and fixtures that aid in the creation of the final product are just as important, if not more so. Power supplies assembled at the TA-55 PF-5 have been designed by an excellent engineering team. The task in PF-5 now is to ensure that all steps of the assembly and manufacturing process can be completed safely, reliably, and in a quality repeatable manner. One of these process steps involves soldering fine wiresmore » to an electrical connector. During the process development phase, the method of soldering included placing the power supply in a vice in order to manipulate it into a position conducive to soldering. This method is unacceptable from a reliability, repeatability, and ergonomic standpoint. To combat these issues, a fixture was designed to replace the current method. To do so, a twelve step engineering design process was used to create the fixture that would provide a solution to a multitude of problems, and increase the safety and efficiency of production.« less

Development of a Thin Gauge Metallic Seal for Gas Turbine Engine Applications to 1700 F

NASA Technical Reports Server (NTRS)

England, Raymond O.

2006-01-01

The goal of doubling thrust-to-weight ratio for gas turbine engines has placed significant demands on engine component materials. Operating temperatures for static seals in the transition duct and turbine sections for instance, may well reach 2000 F within the next ten years. At these temperatures conventional age-hardenable superalloys lose their high strength via overaging and eventual dissolution of the gamma precipitate, and are well above their oxidation stability limit. Conventional solid-solution-strengthened alloys offer metallurgical stability, but suffer from rapid oxidation and little useful load bearing strength. Ceramic materials can theoretically be used at these temperatures, but manufacturing processes are in the developmental stages.

FRIEND Engine Framework: a real time neurofeedback client-server system for neuroimaging studies

PubMed Central

Basilio, Rodrigo; Garrido, Griselda J.; Sato, João R.; Hoefle, Sebastian; Melo, Bruno R. P.; Pamplona, Fabricio A.; Zahn, Roland; Moll, Jorge

2015-01-01

In this methods article, we present a new implementation of a recently reported FSL-integrated neurofeedback tool, the standalone version of “Functional Real-time Interactive Endogenous Neuromodulation and Decoding” (FRIEND). We will refer to this new implementation as the FRIEND Engine Framework. The framework comprises a client-server cross-platform solution for real time fMRI and fMRI/EEG neurofeedback studies, enabling flexible customization or integration of graphical interfaces, devices, and data processing. This implementation allows a fast setup of novel plug-ins and frontends, which can be shared with the user community at large. The FRIEND Engine Framework is freely distributed for non-commercial, research purposes. PMID:25688193

Become a Star: Teaching the Process of Design and Implementation of an Intelligent System

ERIC Educational Resources Information Center

Venables, Anne; Tan, Grace

2005-01-01

Teaching future knowledge engineers, the necessary skills for designing and implementing intelligent software solutions required by business, industry and research today, is a very tall order. These skills are not easily taught in traditional undergraduate computer science lectures; nor are the practical experiences easily reinforced in laboratory…

Wireless Broadband Communications Systems in Rural Wisconsin. Rural Research Report. Volume 19, Issue 1, Spring 2008

ERIC Educational Resources Information Center

Schlager, Kenneth J.

2008-01-01

This report describes a communications system engineering planning process that demonstrates an ability to design and deploy cost-effective broadband networks in low density rural areas. The emphasis in on innovative solutions and systems optimization because of the marginal nature of rural telecommunications infrastructure investments. Otherwise,…

Synthesizing Results from Empirical Research on Computer-Based Scaffolding in STEM Education: A Meta-Analysis

ERIC Educational Resources Information Center

Belland, Brian R.; Walker, Andrew E.; Kim, Nam Ju; Lefler, Mason

2017-01-01

Computer-based scaffolding assists students as they generate solutions to complex problems, goals, or tasks, helping increase and integrate their higher order skills in the process. However, despite decades of research on scaffolding in STEM (science, technology, engineering, and mathematics) education, no existing comprehensive meta-analysis has…

Preface

NASA Astrophysics Data System (ADS)

Faybishenko, Boris; Witherspoon, Paul A.; Gale, John

How to characterize fluid flow, heat, and chemical transport in geologic media remains a central challenge for geoscientists and engineers worldwide. Investigations of fluid flow and transport within rock relate to such fundamental and applied problems as environmental remediation; nonaqueous phase liquid (NAPL) transport; exploitation of oil, gas, and geothermal resources; disposal of spent nuclear fuel; and geotechnical engineering. It is widely acknowledged that fractures in unsaturated-saturated rock can play a major role in solute transport from the land surface to underlying aquifers. It is also evident that general issues concerning flow and transport predictions in subsurface fractured zones can be resolved in a practical manner by integrating investigations into the physical nature of flow in fractures, developing relevant mathematical models and modeling approaches, and collecting site characterization data. Because of the complexity of flow and transport processes in most fractured rock flow problems, it is not yet possible to develop models directly from first principles. One reason for this is the presence of episodic, preferential water seepage and solute transport, which usually proceed more rapidly than expected from volume-averaged and time-averaged models. However, the physics of these processes is still known.

Unleashing Lessons: Sharing Stories About the Fine Art of Systems Engineering

NASA Technical Reports Server (NTRS)

Singer, Christopher E.

2010-01-01

NASA leaders have a responsibility to share their unique oral histories with junior-level employees on whom NASA's future depends. This presentation will give a few examples of how the imaginative, flexible art of systems engineering is as necessary to mission success as is the rigorous, disciplined side of engineering. Engineering space systems involves many disciplines propulsion, loads, dynamics, and so forth that are based on the foundations of scientific principles and methodology and the application of the laws of physics. The term rocket scientist is an apt term, considering that the underlying chemical properties of propellants and the subatomic properties of materials must be understood to harness the powerful energy necessary to escape Earth's gravity in machines that can withstand the stresses and forces to which they are subjected, not to mention the harsh space environments in which they must work. This is a simplistic, yet illustrative, explanation of the scientific side of the engineer s challenge. Bringing together these individual parts into a solid system goes beyond the science of engineering to employ the art of systems engineering. Systems engineers are known for their ability to integrate various solutions to meet or exceed challenging requirements. As the old adage goes, measure twice and cut once. The act of measuring is balancing rigid, inflexible requirements with creative compromises to attain the optimum solution to the challenge of space flight. Then, we cut out those answers that are too risky, expensive, dangerous, and so forth. The process of sharing stories about the little-discussed art of engineering, also known as the art of compromise, will equip the workforce to subjectively judge the best right answer from among the many presented, while objectively integrating the various piece parts into a unified whole.

Improved electron injection in all-solution-processed n-type organic field-effect transistors with an inkjet-printed ZnO electron injection layer

NASA Astrophysics Data System (ADS)

Roh, Jeongkyun; Kim, Hyeok; Park, Myeongjin; Kwak, Jeonghun; Lee, Changhee

2017-10-01

Interface engineering for the improved injection properties of all-solution-processed n-type organic field-effect transistors (OFETs) arising from the use of an inkjet-printed ZnO electron injection layer were demonstrated. The characteristics of ZnO in terms of electron injection and transport were investigated, and then we employed ZnO as the electron injection layer via inkjet-printing during the fabrication of all-solution-processed, n-type OFETs. With the inkjet-printed ZnO electron injection layer, the devices exhibited approximately five-fold increased mobility (0.0058 cm2/V s to 0.030 cm2/V s), more than two-fold increased charge concentration (2.76 × 1011 cm-2 to 6.86 × 1011 cm-2), and two orders of magnitude reduced device resistance (120 MΩ cm to 3 MΩ cm). Moreover, n-type polymer form smoother film with ZnO implying denser packing of polymer, which results in higher mobility.

Design applications for supercomputers

NASA Technical Reports Server (NTRS)

Studerus, C. J.

1987-01-01

The complexity of codes for solutions of real aerodynamic problems has progressed from simple two-dimensional models to three-dimensional inviscid and viscous models. As the algorithms used in the codes increased in accuracy, speed and robustness, the codes were steadily incorporated into standard design processes. The highly sophisticated codes, which provide solutions to the truly complex flows, require computers with large memory and high computational speed. The advent of high-speed supercomputers, such that the solutions of these complex flows become more practical, permits the introduction of the codes into the design system at an earlier stage. The results of several codes which either were already introduced into the design process or are rapidly in the process of becoming so, are presented. The codes fall into the area of turbomachinery aerodynamics and hypersonic propulsion. In the former category, results are presented for three-dimensional inviscid and viscous flows through nozzle and unducted fan bladerows. In the latter category, results are presented for two-dimensional inviscid and viscous flows for hypersonic vehicle forebodies and engine inlets.

From magic to technology: materials integration by wafer bonding

NASA Astrophysics Data System (ADS)

Dragoi, Viorel

2006-02-01

Wafer bonding became in the last decade a very powerful technology for MEMS/MOEMS manufacturing. Being able to offer a solution to overcome some problems of the standard processes used for materials integration (e.g. epitaxy, thin films deposition), wafer bonding is nowadays considered an important item in the MEMS engineer toolbox. Different principles governing the wafer bonding processes will be reviewed in this paper. Various types of applications will be presented as examples.

Photolithography diagnostic expert systems: a systematic approach to problem solving in a wafer fabrication facility

NASA Astrophysics Data System (ADS)

Weatherwax Scott, Caroline; Tsareff, Christopher R.

1990-06-01

One of the main goals of process engineering in the semiconductor industry is to improve wafer fabrication productivity and throughput. Engineers must work continuously toward this goal in addition to performing sustaining and development tasks. To accomplish these objectives, managers must make efficient use of engineering resources. One of the tools being used to improve efficiency is the diagnostic expert system. Expert systems are knowledge based computer programs designed to lead the user through the analysis and solution of a problem. Several photolithography diagnostic expert systems have been implemented at the Hughes Technology Center to provide a systematic approach to process problem solving. This systematic approach was achieved by documenting cause and effect analyses for a wide variety of processing problems. This knowledge was organized in the form of IF-THEN rules, a common structure for knowledge representation in expert system technology. These rules form the knowledge base of the expert system which is stored in the computer. The systems also include the problem solving methodology used by the expert when addressing a problem in his area of expertise. Operators now use the expert systems to solve many process problems without engineering assistance. The systems also facilitate the collection of appropriate data to assist engineering in solving unanticipated problems. Currently, several expert systems have been implemented to cover all aspects of the photolithography process. The systems, which have been in use for over a year, include wafer surface preparation (HMDS), photoresist coat and softbake, align and expose on a wafer stepper, and develop inspection. These systems are part of a plan to implement an expert system diagnostic environment throughout the wafer fabrication facility. In this paper, the systems' construction is described, including knowledge acquisition, rule construction, knowledge refinement, testing, and evaluation. The roles played by the process engineering expert and the knowledge engineer are discussed. The features of the systems are shown, particularly the interactive quality of the consultations and the ease of system use.

Black hole thermodynamics and heat engines in conformal gravity

NASA Astrophysics Data System (ADS)

Xu, Hao; Sun, Yuan; Zhao, Liu

The extended phase-space thermodynamics and heat engines for static spherically symmetric black hole solutions of four-dimensional conformal gravity are studied in detail. It is argued that the equation of states (EOS) for such black holes is always branched, any continuous thermodynamical process cannot drive the system from one branch of the EOS into another branch. Meanwhile, the thermodynamical volume is bounded from above, making the black holes always super-entropic in one branch and may also be super-entropic in another branch in certain range of the temperature. The Carnot and Stirling heat engines associated to such black holes are shown to be distinct from each other. For rectangular heat engines, the efficiency always approaches zero when the rectangle becomes extremely narrow, and given the highest and lowest working temperatures fixed, there is always a maximum for the efficiency of such engines.

Degradation of dyes from aqueous solution by Fenton processes: a review.

PubMed

Nidheesh, Puthiya Veetil; Gandhimathi, Rajan; Ramesh, Srikrishnaperumal Thanga

2013-04-01

Several industries are using dyes as coloring agents. The effluents from these industries are increasingly becoming an environmental problem. The removal of dyes from aqueous solution has a great potential in the field of environmental engineering. This paper reviews the classification, characteristics, and problems of dyes in detail. Advantages and disadvantages of different methods used for dye removal are also analyzed. Among these methods, Fenton process-based advanced oxidation processes are an emerging prospect in the field of dye removal. Fenton processes have been classified and represented as "Fenton circle". This paper analyzes the recent studies on Fenton processes. The studies include analyzing different configurations of reactors used for dye removal, its efficiency, and the effects of various operating parameters such as pH, catalyst concentration, H2O2 concentration, initial dye concentration, and temperature of Fenton processes. From the present study, it can be conclude that Fenton processes are very effective and environmentally friendly methods for dye removal.

Technology Prospecting on Enzymes: Application, Marketing and Engineering

PubMed Central

Li, Shuang; Yang, Xiaofeng; Yang, Shuai; Zhu, Muzi; Wang, Xiaoning

2012-01-01

Enzymes are protein molecules functioning as specialized catalysts for chemical reactions. They have contributed greatly to the traditional and modern chemical industry by improving existing processes. In this article, we first give a survey of representative industrial applications of enzymes, focusing on the technical applications, feed industry, food processing and cosmetic products. The recent important developments and applications of enzymes in industry are reviewed. Then large efforts are dedicated to the worldwide enzyme market from the demand and production perspectives. Special attention is laid on the Chinese enzyme market. Although enzyme applications are being developed in full swing, breakthroughs are needed to overcome their weaknesses in maintaining activities during the catalytic processes. Strategies of metagomic analysis, cell surface display technology and cell-free system might give valuable solutions in novel enzyme exploiting and enzyme engineering. PMID:24688658

Bidirectional optimization of the melting spinning process.

PubMed

Liang, Xiao; Ding, Yongsheng; Wang, Zidong; Hao, Kuangrong; Hone, Kate; Wang, Huaping

2014-02-01

A bidirectional optimizing approach for the melting spinning process based on an immune-enhanced neural network is proposed. The proposed bidirectional model can not only reveal the internal nonlinear relationship between the process configuration and the quality indices of the fibers as final product, but also provide a tool for engineers to develop new fiber products with expected quality specifications. A neural network is taken as the basis for the bidirectional model, and an immune component is introduced to enlarge the searching scope of the solution field so that the neural network has a larger possibility to find the appropriate and reasonable solution, and the error of prediction can therefore be eliminated. The proposed intelligent model can also help to determine what kind of process configuration should be made in order to produce satisfactory fiber products. To make the proposed model practical to the manufacturing, a software platform is developed. Simulation results show that the proposed model can eliminate the approximation error raised by the neural network-based optimizing model, which is due to the extension of focusing scope by the artificial immune mechanism. Meanwhile, the proposed model with the corresponding software can conduct optimization in two directions, namely, the process optimization and category development, and the corresponding results outperform those with an ordinary neural network-based intelligent model. It is also proved that the proposed model has the potential to act as a valuable tool from which the engineers and decision makers of the spinning process could benefit.

Intelligent Weld Manufacturing: Role of Integrated Computational Welding Engineering

DOE PAGES

David, Stan A.; Chen, Jian; Feng, Zhili; ...

2017-12-02

A master welder uses his sensory perceptions to evaluate the process and connect them with his/her knowledge base to take the necessary corrective measures with his/her acquired skills to make a good weld. All these actions must take place in real time. Success depends on intuition and skills, and the procedure is labor-intensive and frequently unreliable. The solution is intelligent weld manufacturing. The ultimate goal of intelligent weld manufacturing would involve sensing and control of heat source position, weld temperature, weld penetration, defect formation and ultimately control of microstructure and properties. This involves a solution to a problem (welding) withmore » many highly coupled and nonlinear variables. The trend is to use an emerging tool known as intelligent control. This approach enables the user to choose a desirable end factor such as properties, defect control, or productivity to derive the selection of process parameters such as current, voltage, or speed to provide for appropriate control of the process. Important elements of intelligent manufacturing are sensing and control theory and design, process modeling, and artificial intelligence. Significant progress has been made in all these areas. Integrated computational welding engineering (ICWE) is an emerging field that will aid in the realization of intelligent weld manufacturing. The paper will discuss the progress in process modeling, microstructure, properties, and process control and automation and the importance of ICWE. Also, control and automation strategies for friction stir welding will be discussed.« less

Intelligent Weld Manufacturing: Role of Integrated Computational Welding Engineering

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

David, Stan A.; Chen, Jian; Feng, Zhili

A master welder uses his sensory perceptions to evaluate the process and connect them with his/her knowledge base to take the necessary corrective measures with his/her acquired skills to make a good weld. All these actions must take place in real time. Success depends on intuition and skills, and the procedure is labor-intensive and frequently unreliable. The solution is intelligent weld manufacturing. The ultimate goal of intelligent weld manufacturing would involve sensing and control of heat source position, weld temperature, weld penetration, defect formation and ultimately control of microstructure and properties. This involves a solution to a problem (welding) withmore » many highly coupled and nonlinear variables. The trend is to use an emerging tool known as intelligent control. This approach enables the user to choose a desirable end factor such as properties, defect control, or productivity to derive the selection of process parameters such as current, voltage, or speed to provide for appropriate control of the process. Important elements of intelligent manufacturing are sensing and control theory and design, process modeling, and artificial intelligence. Significant progress has been made in all these areas. Integrated computational welding engineering (ICWE) is an emerging field that will aid in the realization of intelligent weld manufacturing. The paper will discuss the progress in process modeling, microstructure, properties, and process control and automation and the importance of ICWE. Also, control and automation strategies for friction stir welding will be discussed.« less

Logistics engineering education from the point of view environment

NASA Astrophysics Data System (ADS)

Bányai, Ágota

2010-05-01

A new field of MSc programme offered by the Faculty of Mechanical Engineering and Informatics of the University of Miskolc is represented by the programme in logistics engineering. The Faculty has always laid great emphasis on assigning processes connected with environment protection and globalisation issues the appropriate weight in its programmes. This is based on the fact that the Faculty has initiated and been involved in a great number of research and development projects with a substantial emphasis on the fundamental principles of sustainable development. The objective of the programme of logistics engineering is to train engineers who, in possession of the science, engineering, economic, informatics and industrial, transportation technological knowledge related to the professional field of logistics, are able to analyse, design, organise, and control logistics processes and systems (freight transportation, materials handling, storage, commissioning, loading, purchasing, distribution and waste management) as well as to design and develop machinery and equipment as the elements of logistic systems and also to be involved in their manufacture and quality control and are able to control their operation. The programme prepares its students for performing the logistics management tasks in a company, for creative participation in solving research and development problems in logistics and for pursuing logistics studies in doctoral programmes. There are several laboratories available for practice-oriented training. The 'Integrated Logistics Laboratory' consists of various fixed and mobile, real industrial, i.e. not model-level equipment, the integration of which in one system facilitates not only the presentation, examination and development of the individual self-standing facilities, but the study of their interaction as well in terms of mechatronics, engineering, control engineering, informatics, identification technology and logistics. The state-of-the-art, reliable, automated mechatronics-material flow system with its single control engineering system provides the academic staff with up-to-date research facilities, and enables the students to study sophisticated equipment and systems that could also operate under industrial conditions, thus offering knowledge that can be efficiently utilised in the industry after graduation. The laboratory measurements of the programme in logistics engineering are performed in this laboratory, and they are supplemented by the theoretical and practical measurements in the ‘Robotic Technology Assembly Laboratory', the ‘Power Electronics Laboratory', the ‘Mechatronics Laboratory', the ‘CAD/CAM Laboratory' and the ‘Acoustics and Product Laboratory'. The bodies of knowledge connected with environment protection and sustainable development can be grouped around three large topic areas. In environmental economics the objective is to present the corporate-organisational aspects of environmental management. Putting environmental management in the focal point, the objective of the programme is to impart knowledge that can be utilised in practice which can be used to shift the relation between the organisation and its environment in the direction of sustainability. The tools include environmental controlling, environmental marketing and various solutions of environmental performance evaluation. The second large topic area is globalization and its logistic aspects. In the field of global logistics the following knowledge carries special weight: logistic challenges in a globalised world; the concept of global logistics, its conditions and effects; delayed manufacture, assembly, packaging; the economic investigation of delayed assembly; globalised purchase and distribution in logistics; the logistic features of the globalised production supply/distribution chain; meta-logistics systems; logistics-related EU harmonisation issues; the effect of e-commerce on the global logistic system; logistic centres, connecting virtual logistic companies in a network; the environmental harmonisation of international transportation. The third large area is recycling logistics. Here the bodies of knowledge are as follows: the concept of developing a ‘closed-loop economy'; stages in the progress of products after discarding, connections between the uses of waste collection, processing, selection, deposition or reuse processes; features of European recommendations (e.g. EMAS), harmonisation of national practices and global solutions; presenting the logistics part-processes of recycling; presenting process organisation procedures for the foundation of designing one-route, multi-route, replacement container waste collecting and distributing part systems; recycling strategies with consideration of logistically serving the separation and storage of waste to be deposited, the technological processing systems of recyclable materials; presenting dismantling and product and material identification technologies, presenting logistics part-tasks, analysis of technical solutions; IT solutions for identifying products and their elements to be distributed and withdrawn from distribution after use (e.g. RFID systems) and monitoring their material flow; methodology of using efficiency analyses and incentive systems in the decision making processes of recycling processes, risk analysis for evaluating typical part processes; the methodology of recycling-oriented product design for specific product groups. Graduates of the Master programmes are able to use and utilise the knowledge obtained in practice, use problem-solving techniques; process the information, new problems and new phenomena arising in the border areas of the professional experience gained the discipline; formulate substantial criticism and opinions as far as possible, make decisions and draw conclusions; comprehending and solving the problems arising, suggesting original ideas; plan and perform tasks independently at a high professional standard; improve themselves, develop their knowledge to higher levels; view the management of technical/engineering - economic - human resources in a complex way; design complex systems in a global way based on a system-oriented and process-oriented way of thinking; use integrated knowledge from the professional fields of transport, mobile machinery, process theory, industrial production processes, electronics and informatics; combine the part processes of logistics systems and the part units performing their physical realisation (materials handling equipment, sensors, actuators, control systems, and database systems, etc.); perform state evaluations depending on their specialisation, use them to elaborate evaluations and recommendations, develop complex logistic systems, design, organise and control them at the highest level. This work was implemented with support by the European Union and co-funding of the European Social Fund.

The potential application of the blackboard model of problem solving to multidisciplinary design

NASA Technical Reports Server (NTRS)

Rogers, J. L.

1989-01-01

Problems associated with the sequential approach to multidisciplinary design are discussed. A blackboard model is suggested as a potential tool for implementing the multilevel decomposition approach to overcome these problems. The blackboard model serves as a global database for the solution with each discipline acting as a knowledge source for updating the solution. With this approach, it is possible for engineers to improve the coordination, communication, and cooperation in the conceptual design process, allowing them to achieve a more optimal design from an interdisciplinary standpoint.

BioMOL: a computer-assisted biological modeling tool for complex chemical mixtures and biological processes at the molecular level.

PubMed Central

Klein, Michael T; Hou, Gang; Quann, Richard J; Wei, Wei; Liao, Kai H; Yang, Raymond S H; Campain, Julie A; Mazurek, Monica A; Broadbelt, Linda J

2002-01-01

A chemical engineering approach for the rigorous construction, solution, and optimization of detailed kinetic models for biological processes is described. This modeling capability addresses the required technical components of detailed kinetic modeling, namely, the modeling of reactant structure and composition, the building of the reaction network, the organization of model parameters, the solution of the kinetic model, and the optimization of the model. Even though this modeling approach has enjoyed successful application in the petroleum industry, its application to biomedical research has just begun. We propose to expand the horizons on classic pharmacokinetics and physiologically based pharmacokinetics (PBPK), where human or animal bodies were often described by a few compartments, by integrating PBPK with reaction network modeling described in this article. If one draws a parallel between an oil refinery, where the application of this modeling approach has been very successful, and a human body, the individual processing units in the oil refinery may be considered equivalent to the vital organs of the human body. Even though the cell or organ may be much more complicated, the complex biochemical reaction networks in each organ may be similarly modeled and linked in much the same way as the modeling of the entire oil refinery through linkage of the individual processing units. The integrated chemical engineering software package described in this article, BioMOL, denotes the biological application of molecular-oriented lumping. BioMOL can build a detailed model in 1-1,000 CPU sec using standard desktop hardware. The models solve and optimize using standard and widely available hardware and software and can be presented in the context of a user-friendly interface. We believe this is an engineering tool with great promise in its application to complex biological reaction networks. PMID:12634134

Assessment Processes to Increase the Burden of Existing Buildings Using BIM

NASA Astrophysics Data System (ADS)

Szeląg, Romuald

2017-10-01

The process of implementation of the reconstruction of buildings is often associated with the need to adapt them to increased loads. In the restricted access to the archive project documentation it is necessary to use technical solutions to obtain a fairly short period of time necessary to implement the technical parameters of such processes. Dissemination of BIM in the design process can also be used effectively in the processes of identification of existing facilities for the implementation of the work of strengthening or adapting objects to the increased load requirements. Obtained in the process of research and macroscopic data is then used in the processes of numerical processing aimed at developing a numerical model reflects the actual parameters of the structure of the existing structure and, therefore, allows a better look at the object and the execution of the process to strengthen future. This article will identify possibilities for the use of BIM in processes of identification technology buildings and structures and indicated the necessary data to be obtained during the preliminary work. Introduced in model solutions enable the use of multi-criteria analysis of the choice of the most optimal solutions in terms of costs or expenditures of time during the process of construction. Taking the above work by building a numerical model of the object allows every step of verification by authorized person inventoried solutions and enables tracking and changes in the situation of those found derogations in relation to the parameters established at the primary stage. In the event of significant deviations, there is the possibility of rapid changes to the completed process of calculation and presentation of alternative solutions. Availability software using BIM technology is increasingly common here knowledge of the implementation of such solutions will become in a short time, the standard for most objects or engineering structures. The use of modern solutions using the described processes will be discussed on the example of an industrial facility where there was a need for installation of new equipment and adapt it to the technical parameters.

Engineered Barrier System: Physical and Chemical Environment

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

P. Dixon

2004-04-26

The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming bymore » deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.« less

Systems engineering in practice: can rigour and creativity co-exist?

NASA Astrophysics Data System (ADS)

Schnetler, Hermine; Rees, Philip; Egan, Ian

2006-06-01

Systems engineering as a discipline has been established for many years, being utilised to good effect most notably, in the defence industry. Its introduction in a formalised way to the UK ATC is relatively recent. Although a good start has been made in embedding the process within the lifecycle model, much work is still required to refine the systems engineering elements to cope with the complex (internationally collaborative) business model, the need to nurture creativity in the design process and the translation into a highly challenging cost-driven technology domain. This paper explores the current status of systems engineering at the UK ATC, shows where further work is needed, and how improvements can be made to meet the challenges of next generation telescopes and instrumentation. It is shown why the discipline is necessary, especially given that projects often comprise diverse global teams (both small and large), and it indicates the pitfalls of a tendency in the early stages of a project to focus on solutions rather than robust requirements capture. Finally, despite the obvious value and yet often ill-understood rigours of system engineering, it is shown how innovation and creativity can be promoted rather than stifled.

Realizing Full Coverage of Stable Perovskite Film by Modified Anti-Solvent Process

NASA Astrophysics Data System (ADS)

Ji, Long; Zhang, Ting; Wang, Yafei; Zhang, Peng; Liu, Detao; Chen, Zhi; Li, Shibin

2017-05-01

Lead-free solution-processed solid-state photovoltaic devices based on formamidinium tin triiodide (FASnI3) and cesium tin triiodide (CsSnI3) perovskite semiconductor as the light harvester are reported. In this letter, we used solvent engineering and anti-solvent dripping method to fabricate perovskite films. SnCl2 was used as an inhibitor of Sn4+ in FASnI3 precursor solution. We obtained the best films under the function of toluene or chlorobenzene in anti-solvent dripping method and monitored the oxidation of FASnI3 films in air. We chose SnF2 as an additive of CsSnI3 precursor solution to prevent the oxidation of the Sn2+, improving the stability of CsSnI3. The experimental results we obtained can pave the way for lead-free tin-based perovskite solar cells (PSCs).

Molecular-dynamics simulations of urea nucleation from aqueous solution

PubMed Central

Salvalaglio, Matteo; Perego, Claudio; Giberti, Federico; Mazzotti, Marco; Parrinello, Michele

2015-01-01

Despite its ubiquitous character and relevance in many branches of science and engineering, nucleation from solution remains elusive. In this framework, molecular simulations represent a powerful tool to provide insight into nucleation at the molecular scale. In this work, we combine theory and molecular simulations to describe urea nucleation from aqueous solution. Taking advantage of well-tempered metadynamics, we compute the free-energy change associated to the phase transition. We find that such a free-energy profile is characterized by significant finite-size effects that can, however, be accounted for. The description of the nucleation process emerging from our analysis differs from classical nucleation theory. Nucleation of crystal-like clusters is in fact preceded by large concentration fluctuations, indicating a predominant two-step process, whereby embryonic crystal nuclei emerge from dense, disordered urea clusters. Furthermore, in the early stages of nucleation, two different polymorphs are seen to compete. PMID:25492932

Molecular-dynamics simulations of urea nucleation from aqueous solution.

PubMed

Salvalaglio, Matteo; Perego, Claudio; Giberti, Federico; Mazzotti, Marco; Parrinello, Michele

2015-01-06

Despite its ubiquitous character and relevance in many branches of science and engineering, nucleation from solution remains elusive. In this framework, molecular simulations represent a powerful tool to provide insight into nucleation at the molecular scale. In this work, we combine theory and molecular simulations to describe urea nucleation from aqueous solution. Taking advantage of well-tempered metadynamics, we compute the free-energy change associated to the phase transition. We find that such a free-energy profile is characterized by significant finite-size effects that can, however, be accounted for. The description of the nucleation process emerging from our analysis differs from classical nucleation theory. Nucleation of crystal-like clusters is in fact preceded by large concentration fluctuations, indicating a predominant two-step process, whereby embryonic crystal nuclei emerge from dense, disordered urea clusters. Furthermore, in the early stages of nucleation, two different polymorphs are seen to compete.

Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

NASA Astrophysics Data System (ADS)

Ryan, R.; Gross, L. A.

1995-05-01

The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

NASA Technical Reports Server (NTRS)

Ryan, R.; Gross, L. A.

1995-01-01

The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

THRSTER: A THRee-STream Ejector Ramjet Analysis and Design Tool

NASA Technical Reports Server (NTRS)

Chue, R. S.; Sabean, J.; Tyll, J.; Bakos, R. J.

2000-01-01

An engineering tool for analyzing ejectors in rocket based combined cycle (RBCC) engines has been developed. A key technology for multi-cycle RBCC propulsion systems is the ejector which functions as the compression stage of the ejector ramjet cycle. The THRee STream Ejector Ramjet analysis tool was developed to analyze the complex aerothermodynamic and combustion processes that occur in this device. The formulated model consists of three quasi-one-dimensional streams, one each for the ejector primary flow, the secondary flow, and the mixed region. The model space marches through the mixer, combustor, and nozzle to evaluate the solution along the engine. In its present form, the model is intended for an analysis mode in which the diffusion rates of the primary and secondary into the mixed stream are stipulated. The model offers the ability to analyze the highly two-dimensional ejector flowfield while still benefits from the simplicity and speed of an engineering tool. To validate the developed code, wall static pressure measurements from the Penn-State and NASA-ART RBCC experiments were used to compare with the results generated by the code. The calculated solutions were generally found to have satisfactory agreement with the pressure measurements along the engines, although further modeling effort may be required when a strong shock train is formed at the rocket exhaust. The range of parameters in which the code would generate valid results are presented and discussed.

THRSTER: A Three-Stream Ejector Ramjet Analysis and Design Tool

NASA Technical Reports Server (NTRS)

Chue, R. S.; Sabean, J.; Tyll, J.; Bakos, R. J.; Komar, D. R. (Technical Monitor)

2000-01-01

An engineering tool for analyzing ejectors in rocket based combined cycle (RBCC) engines has been developed. A key technology for multi-cycle RBCC propulsion systems is the ejector which functions as the compression stage of the ejector ramjet cycle. The THRee STream Ejector Ramjet analysis tool was developed to analyze the complex aerothermodynamic and combustion processes that occur in this device. The formulated model consists of three quasi-one-dimensional streams, one each for the ejector primary flow, the secondary flow, and the mixed region. The model space marches through the mixer, combustor, and nozzle to evaluate the solution along the engine. In its present form, the model is intended for an analysis mode in which the diffusion rates of the primary and secondary into the mixed stream are stipulated. The model offers the ability to analyze the highly two-dimensional ejector flowfield while still benefits from the simplicity and speed of an engineering tool. To validate the developed code, wall static pressure measurements from the Penn-State and NASA-ART RBCC experiments were used to compare with the results generated by the code. The calculated solutions were generally found to have satisfactory agreement with the pressure measurements along the engines, although further modeling effort may be required when a strong shock train is formed at the rocket exhaust. The range of parameters in which the code would generate valid results are presented and discussed.

Using Life-Cycle Human Factors Engineering to Avoid $2.4 Million in Costs: Lessons Learned from NASA's Requirements Verification Process for Space Payloads

NASA Technical Reports Server (NTRS)

Carr, Daniel; Ellenberger, Rich

2008-01-01

The Human Factors Implementation Team (HFIT) process has been used to verify human factors requirements for NASA International Space Station (ISS) payloads since 2003, resulting in $2.4 million in avoided costs. This cost benefit has been realized by greatly reducing the need to process time-consuming formal waivers (exceptions) for individual requirements violations. The HFIT team, which includes astronauts and their technical staff, acts as the single source for human factors requirements integration of payloads. HFIT has the authority to provide inputs during early design phases, thus eliminating many potential requirements violations in a cost-effective manner. In those instances where it is not economically or technically feasible to meet the precise metric of a given requirement, HFIT can work with the payload engineers to develop common sense solutions and formally document that the resulting payload design does not materially affect the astronaut s ability to operate and interact with the payload. The HFIT process is fully ISO 9000 compliant and works concurrently with NASA s formal systems engineering work flow. Due to its success with payloads, the HFIT process is being adapted and extended to ISS systems hardware. Key aspects of this process are also being considered for NASA's Space Shuttle replacement, the Crew Exploration Vehicle.

UCS-PROMOVE: The engineer of the future

NASA Astrophysics Data System (ADS)

Villas-Boas, V.

2010-06-01

The Universidade de Caxias do Sul (UCS) elaborated the cooperative project called 'The engineer of the future', with the objective of promoting science and engineering among high school teachers and students. This project aims to improve the quality of the teaching and to increase the interest of students in technological areas, leading to a future career in engineering. The activities of this project were planned to give meaning and foundation to the teaching-learning process of science and for the application of theory in the solution of real problems, while articulating scientific, economic, environmental, social and political aspects and also to reinforce the important role of engineering in society. Amongst the activities to be offered to high school teachers and students are a specialisation course for teachers based upon new educational methodologies, workshops in different areas of science and technology, a programme entitled 'Encouraging girls in technology, science and engineering', science fairs and visits to the industries of the region. Activities with the engineering instructors of UCS are also being developed in order to help them to incorporate in their classes more effective pedagogical strategies for educating the engineer-to-be.

Implementation of a Goal-Based Systems Engineering Process Using the Systems Modeling Language (SysML)

NASA Technical Reports Server (NTRS)

Patterson, Jonathan D.; Breckenridge, Jonathan T.; Johnson, Stephen B.

2013-01-01

Building upon the purpose, theoretical approach, and use of a Goal-Function Tree (GFT) being presented by Dr. Stephen B. Johnson, described in a related Infotech 2013 ISHM abstract titled "Goal-Function Tree Modeling for Systems Engineering and Fault Management", this paper will describe the core framework used to implement the GFTbased systems engineering process using the Systems Modeling Language (SysML). These two papers are ideally accepted and presented together in the same Infotech session. Statement of problem: SysML, as a tool, is currently not capable of implementing the theoretical approach described within the "Goal-Function Tree Modeling for Systems Engineering and Fault Management" paper cited above. More generally, SysML's current capabilities to model functional decompositions in the rigorous manner required in the GFT approach are limited. The GFT is a new Model-Based Systems Engineering (MBSE) approach to the development of goals and requirements, functions, and its linkage to design. As a growing standard for systems engineering, it is important to develop methods to implement GFT in SysML. Proposed Method of Solution: Many of the central concepts of the SysML language are needed to implement a GFT for large complex systems. In the implementation of those central concepts, the following will be described in detail: changes to the nominal SysML process, model view definitions and examples, diagram definitions and examples, and detailed SysML construct and stereotype definitions.

Systems Engineering and Management Applications of ISO 9001:2015 for Government

NASA Technical Reports Server (NTRS)

Shepherd, Christena C.

2016-01-01

The manufacturing segment of the business world is busy assessing the impact of ISO 9001:2015, and updating their management systems to meet the required compliance date. What does the new revision mean for government agencies that deliver large engineering projects rather than mass production? In fact, the standard, especially the new revision, can be used quite readily for government agencies, or applied to specific projects, once it is understood in terms of the similarities with systems engineering and project management. From there it can be extrapolated to "mission realization" systems, and a Quality Management System (QMS) is a logical result that can bring order to processes and systems that likely already exist in some fashion. ISO 9001:2015 is less product-oriented than previous versions. It can be more broadly applied to public organizations as well as private; and to services (missions) as well as products. The emphasis on risk management in the revised standard provides the needed balance for weighing decisions with respect to cost, schedule, technical, safety, and regulatory compliance; so if this is not part of agency governance already, this is a good place to start, especially for large engineering projects. The Systems Engineering standard used for this analysis is from NASA's NPR 7123.1 NASA Systems Engineering Processes and Requirements; however, those who are more familiar with ISO/IEC 26702 Systems Engineering-application and management of the systems engineering process, or SAE/EIA 632 Processes for Engineering a System will also recognize the similarities. In reality, the QMS outlined by ISO 9001 reinforces the systems engineering processes, and serves to ensure that they are adequately implemented, although most of the ISO 9001 literature emphasizes the production and process aspects of the standard. Rather than beginning with ISO 9001and getting lost in the vocabulary, it is useful to begin with the systems engineering lifecycle. Identification of stakeholder expectations, identifying solutions, creating specific product or service designs, production of the product or service, delivery to the public, and the associated management, planning, and control processes, are a familiar place to begin thinking of the overall system of identifying, designing, and competing a project or mission. Lining up this lifecycle with the ISO requirements (see Figure 1) illustrates how a quality management system is concerned with the same processes, and provides a governance and assurance function. If implemented properly, there are cost savings resulting from less rework, repair, reprocessing, failures, misplaced documents, and similar types of deficiencies1. Starting with an organization's systems engineering processes allows the organization to use their own terminology for a QMS plan, and tailor the plan to their own project or organization, so that it is more easily developed, understood, and implemented.

The fusion of biology, computer science, and engineering: towards efficient and successful synthetic biology.

PubMed

Linshiz, Gregory; Goldberg, Alex; Konry, Tania; Hillson, Nathan J

2012-01-01

Synthetic biology is a nascent field that emerged in earnest only around the turn of the millennium. It aims to engineer new biological systems and impart new biological functionality, often through genetic modifications. The design and construction of new biological systems is a complex, multistep process, requiring multidisciplinary collaborative efforts from "fusion" scientists who have formal training in computer science or engineering, as well as hands-on biological expertise. The public has high expectations for synthetic biology and eagerly anticipates the development of solutions to the major challenges facing humanity. This article discusses laboratory practices and the conduct of research in synthetic biology. It argues that the fusion science approach, which integrates biology with computer science and engineering best practices, including standardization, process optimization, computer-aided design and laboratory automation, miniaturization, and systematic management, will increase the predictability and reproducibility of experiments and lead to breakthroughs in the construction of new biological systems. The article also discusses several successful fusion projects, including the development of software tools for DNA construction design automation, recursive DNA construction, and the development of integrated microfluidics systems.

Analysis of the flow field generated near an aircraft engine operating in reverse thrust. M.S. Thesis

NASA Technical Reports Server (NTRS)

Ledwith, W. A., Jr.

1972-01-01

A computer solution is developed to the exhaust gas reingestion problem for aircraft operating in the reverse thrust mode on a crosswind-free runway. The computer program determines the location of the inlet flow pattern, whether the exhaust efflux lies within the inlet flow pattern or not, and if so, the approximate time before the reversed flow reaches the engine inlet. The program is written so that the user is free to select discrete runway speeds or to study the entire aircraft deceleration process for both the far field and cross-ingestion problems. While developed with STOL applications in mind, the solution is equally applicable to conventional designs. The inlet and reversed jet flow fields involved in the problem are assumed to be noninteracting. The nacelle model used in determining the inlet flow field is generated using an iterative solution to the Neuman problem from potential flow theory while the reversed jet flow field is adapted using an empirical correlation from the literature. Sample results obtained using the program are included.

Reducing commercial fishing deck hazards with engineering solutions for winch design.

PubMed

Lincoln, Jennifer M; Lucas, Devin L; McKibbin, Robert W; Woodward, Chelsea C; Bevan, John E

2008-01-01

The majority (67%) of hospitalized injuries among Alaska commercial fishermen are associated with deck machinery. This paper describes the "Prevention Through Design" process to mitigate one serious machinery entanglement hazard posed by a capstan deck winch. After observing that the capstan winch provides no entanglement protection and the hydraulic controls are usually out of reach of the entangled person, NIOSH personnel met with fishermen and winch manufacturers to discuss various design solutions to mitigate these hazards. An emergency-stop ("e-stop") system was developed that incorporated a momentary contact button that when pushed, switches a safety-relay that de-energizes the solenoid of an electro-hydraulic valve stopping the rotating winch. The vessel owners that had the e-stop installed enthusiastically recommend it to other fishermen. NIOSH entered into a Proprietary Technology Licensing Agreement with a company to develop the system for commercial use. This is an example of a practical engineering control that effectively protects workers from a hazardous piece of equipment by preventing injuries due to entanglement. This solution could reduce these types of debilitating injuries and fatalities in this industry.

Teaching Problem-Solving Skills to Nuclear Engineering Students

ERIC Educational Resources Information Center

Waller, E.; Kaye, M. H.

2012-01-01

Problem solving is an essential skill for nuclear engineering graduates entering the workforce. Training in qualitative and quantitative aspects of problem solving allows students to conceptualise and execute solutions to complex problems. Solutions to problems in high consequence fields of study such as nuclear engineering require rapid and…

Simplified combustion noise theory yielding a prediction of fluctuating pressure level

NASA Technical Reports Server (NTRS)

Huff, R. G.

1984-01-01

The first order equations for the conservation of mass and momentum in differential form are combined for an ideal gas to yield a single second order partial differential equation in one dimension and time. Small perturbation analysis is applied. A Fourier transformation is performed that results in a second order, constant coefficient, nonhomogeneous equation. The driving function is taken to be the source of combustion noise. A simplified model describing the energy addition via the combustion process gives the required source information for substitution in the driving function. This enables the particular integral solution of the nonhomogeneous equation to be found. This solution multiplied by the acoustic pressure efficiency predicts the acoustic pressure spectrum measured in turbine engine combustors. The prediction was compared with the overall sound pressure levels measured in a CF6-50 turbofan engine combustor and found to be in excellent agreement.

Robot-aided electrospinning toward intelligent biomedical engineering.

PubMed

Tan, Rong; Yang, Xiong; Shen, Yajing

2017-01-01

The rapid development of robotics offers new opportunities for the traditional biofabrication in higher accuracy and controllability, which provides great potentials for the intelligent biomedical engineering. This paper reviews the state of the art of robotics in a widely used biomaterial fabrication process, i.e., electrospinning, including its working principle, main applications, challenges, and prospects. First, the principle and technique of electrospinning are introduced by categorizing it to melt electrospinning, solution electrospinning, and near-field electrospinning. Then, the applications of electrospinning in biomedical engineering are introduced briefly from the aspects of drug delivery, tissue engineering, and wound dressing. After that, we conclude the existing problems in traditional electrospinning such as low production, rough nanofibers, and uncontrolled morphology, and then discuss how those problems are addressed by robotics via four case studies. Lastly, the challenges and outlooks of robotics in electrospinning are discussed and prospected.

The social nature of engineering and its implications for risk taking.

PubMed

Ross, Allison; Athanassoulis, Nafsika

2010-03-01

Making decisions with an, often significant, element of risk seems to be an integral part of many of the projects of the diverse profession of engineering. Whether it be decisions about the design of products, manufacturing processes, public works, or developing technological solutions to environmental, social and global problems, risk taking seems inherent to the profession. Despite this, little attention has been paid to the topic and specifically to how our understanding of engineering as a distinctive profession might affect how we should make decisions under risk. This paper seeks to remedy this, firstly by offering a nuanced account of risk and then by considering how specific claims about our understanding of engineering as a social profession, with corresponding social values and obligations, should inform how we make decisions about risk in this context.

High-Fidelity Three-Dimensional Simulation of the GE90

NASA Technical Reports Server (NTRS)

Turner, Mark G.; Norris, Andrew; Veres, Josphe P.

2004-01-01

A full-engine simulation of the three-dimensional flow in the GE90 94B high-bypass ratio turbofan engine has been achieved. It would take less than 11 hr of wall clock time if starting from scratch through the exploitation of parallel processing. The simulation of the compressor components, the cooled high-pressure turbine, and the low-pressure turbine was performed using the APNASA turbomachinery flow code. The combustor flow and chemistry were simulated using the National Combustor Code (NCC). The engine simulation matches the engine thermodynamic cycle for a sea-level takeoff condition. The simulation is started at the inlet of the fan and progresses downstream. Comparisons with the cycle point are presented. A detailed look at the blockage in the turbomachinery is presented as one measure to assess and view the solution and the multistage interaction effects.

Perspectives on the design of safer nanomaterials and manufacturing processes

NASA Astrophysics Data System (ADS)

Geraci, Charles; Heidel, Donna; Sayes, Christie; Hodson, Laura; Schulte, Paul; Eastlake, Adrienne; Brenner, Sara

2015-09-01

A concerted effort is being made to insert Prevention through Design principles into discussions of sustainability, occupational safety and health, and green chemistry related to nanotechnology. Prevention through Design is a set of principles, which includes solutions to design out potential hazards in nanomanufacturing including the design of nanomaterials, and strategies to eliminate exposures and minimize risks that may be related to the manufacturing processes and equipment at various stages of the lifecycle of an engineered nanomaterial.

Organized DFM

NASA Astrophysics Data System (ADS)

Sato, Takashi; Honma, Michio; Itoh, Hiroyuki; Iriki, Nobuyuki; Kobayashi, Sachiko; Miyazaki, Norihiko; Onodera, Toshio; Suzuki, Hiroyuki; Yoshioka, Nobuyuki; Arima, Sumika; Kadota, Kazuya

2009-04-01

The category and objective of DFM production management are shown. DFM is not limited to an activity within a particular unit process in design and process. A new framework for DFM is required. DFM should be a total solution for the common problems of all processes. Each of them must be linked to one another organically. After passing through the whole of each process on the manufacturing platform, quality of final products is guaranteed and products are shipped to the market. The information platform is layered with DFM, APC, and AEC. Advanced DFM is not DFM for partial optimization of the lithography process and the design, etc. and it should be Organized DFM. They are managed with high-level organizational IQ. The interim quality between each step of the flow should be visualized. DFM will be quality engineering if it is Organized DFM and common metrics of the quality are provided. DFM becomes quality engineering through effective implementation of common industrial metrics and standardized technology. DFM is differential technology, but can leverage standards for efficient development.

Joint Command and Control: Integration Not Interoperability

DTIC Science & Technology

2013-03-01

separate computer and communication equipment. Besides having to engineer interoperability, the Services also must determine the level of...effects.  Determines force responsiveness and allocates resources.5 This thesis argues Joint military operations will never be fully integrated as...processes and systems. Secondly, the limited depth of discussion risks implying (or the reader inferring) the solution is more straightforward than

Incorporating Prototyping and Iteration into Intervention Development: A Case Study of a Dining Hall-Based Intervention

ERIC Educational Resources Information Center

McClain, Arianna D.; Hekler, Eric B.; Gardner, Christopher D.

2013-01-01

Background: Previous research from the fields of computer science and engineering highlight the importance of an iterative design process (IDP) to create more creative and effective solutions. Objective: This study describes IDP as a new method for developing health behavior interventions and evaluates the effectiveness of a dining hall--based…

Problem Definition as a Stimulus to the Creative Process: Analysis of a Classroom Exercise

ERIC Educational Resources Information Center

Vizioli, Renato; Kaminski, Paulo Carlos

2017-01-01

Dealing with problem-solving has been a growing challenge in teaching engineering and over the career of these professionals. To increase the ability to understand a problem and consequently improve the quality of the solutions, an exercise was proposed to students of an MBA program, and they have experienced some challenges on interpreting…

Electrokinetic decontamination of concrete. Final report, August 3, 1993--September 15, 1996

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

NONE

1998-12-31

The ELECTROSORB{reg_sign} {open_quotes}C{close_quotes} process is an electrokinetic process for decontaminating concrete. ELECTROSORB{reg_sign} {open_quotes}C{close_quotes} uses a carpet-like extraction pad which is placed on the contaminated concrete surface. An electrolyte solution is circulated from a supporting module. This module keeps the electrolyte solution clean. The work is advancing through the engineering development stage with steady progress toward a full scale demonstration unit which will be ready for incorporation in the DOE Large Scale Demonstration Program by Summer 1997. A demonstration was carried out at the Mound Facility in Miamisburg, Ohio, in June 1996. Third party verification by EG&G verified the effectiveness ofmore » the process. Results of this work and the development work that proceeded are described herein.« less

Laser ignition - Spark plug development and application in reciprocating engines

NASA Astrophysics Data System (ADS)

Pavel, Nicolaie; Bärwinkel, Mark; Heinz, Peter; Brüggemann, Dieter; Dearden, Geoff; Croitoru, Gabriela; Grigore, Oana Valeria

2018-03-01

Combustion is one of the most dominant energy conversion processes used in all areas of human life, but global concerns over exhaust gas pollution and greenhouse gas emission have stimulated further development of the process. Lean combustion and exhaust gas recirculation are approaches to improve the efficiency and to reduce pollutant emissions; however, such measures impede reliable ignition when applied to conventional ignition systems. Therefore, alternative ignition systems are a focus of scientific research. Amongst others, laser induced ignition seems an attractive method to improve the combustion process. In comparison with conventional ignition by electric spark plugs, laser ignition offers a number of potential benefits. Those most often discussed are: no quenching of the combustion flame kernel; the ability to deliver (laser) energy to any location of interest in the combustion chamber; the possibility of delivering the beam simultaneously to different positions, and the temporal control of ignition. If these advantages can be exploited in practice, the engine efficiency may be improved and reliable operation at lean air-fuel mixtures can be achieved, making feasible savings in fuel consumption and reduction in emission of exhaust gasses. Therefore, laser ignition can enable important new approaches to address global concerns about the environmental impact of continued use of reciprocating engines in vehicles and power plants, with the aim of diminishing pollutant levels in the atmosphere. The technology can also support increased use of electrification in powered transport, through its application to ignition of hybrid (electric-gas) engines, and the efficient combustion of advanced fuels. In this work, we review the progress made over the last years in laser ignition research, in particular that aimed towards realizing laser sources (or laser spark plugs) with dimensions and properties suitable for operating directly on an engine. The main envisaged solutions for positioning of the laser spark plug, i.e. placing it apart from or directly on the engine, are introduced. The path taken from the first solution proposed, to build a compact laser suitable for ignition, to the practical realization of a laser spark plug is described. Results obtained by ignition of automobile test engines, with laser devices that resemble classical spark plugs, are specifically discussed. It is emphasized that technological advances have brought this method of laser ignition close to the application and installation in automobiles powered by gasoline engines. Achievements made in the laser ignition of natural gas engines are outlined, as well as the utilization of laser ignition in other applications. Scientific and technical advances have allowed realization of laser devices with multiple (up to four) beam outputs, but many other important aspects (such as integration, thermal endurance or vibration strength) are still to be solved. Recent results of multi-beam ignition of a single-cylinder engine in a test bench set-up are encouraging and have led to increased research interest in this direction. A fundamental understanding of the processes involved in laser ignition is crucial in order to exploit the technology's full potential. Therefore, several measurement techniques, primarily optical types, used to characterize the laser ignition process are reviewed in this work.

Human Factors Operability Timeline Analysis to Improve the Processing Flow of the Orion Spacecraft

NASA Technical Reports Server (NTRS)

Stambolian, Damon B.; Schlierf, Roland; Miller, Darcy; Posada, Juan; Haddock, Mike; Haddad, Mike; Tran, Donald; Henderon, Gena; Barth, Tim

2011-01-01

This slide presentation reviews the use of Human factors and timeline analysis to have a more efficient and effective processing flow. The solution involved developing a written timeline of events that included each activity within each functional flow block. Each activity had computer animation videos and pictures of the people involved and the hardware. The Human Factors Engineering Analysis Tool (HFEAT) was improved by modifying it to include the timeline of events. The HFEAT was used to define the human factors requirements and design solutions were developed for these requirements. An example of a functional flow block diagram is shown, and a view from one of the animations (i.e., short stack pallet) is shown and explained.

Compute as Fast as the Engineers Can Think! ULTRAFAST COMPUTING TEAM FINAL REPORT

NASA Technical Reports Server (NTRS)

Biedron, R. T.; Mehrotra, P.; Nelson, M. L.; Preston, M. L.; Rehder, J. J.; Rogersm J. L.; Rudy, D. H.; Sobieski, J.; Storaasli, O. O.

1999-01-01

This report documents findings and recommendations by the Ultrafast Computing Team (UCT). In the period 10-12/98, UCT reviewed design case scenarios for a supersonic transport and a reusable launch vehicle to derive computing requirements necessary for support of a design process with efficiency so radically improved that human thought rather than the computer paces the process. Assessment of the present computing capability against the above requirements indicated a need for further improvement in computing speed by several orders of magnitude to reduce time to solution from tens of hours to seconds in major applications. Evaluation of the trends in computer technology revealed a potential to attain the postulated improvement by further increases of single processor performance combined with massively parallel processing in a heterogeneous environment. However, utilization of massively parallel processing to its full capability will require redevelopment of the engineering analysis and optimization methods, including invention of new paradigms. To that end UCT recommends initiation of a new activity at LaRC called Computational Engineering for development of new methods and tools geared to the new computer architectures in disciplines, their coordination, and validation and benefit demonstration through applications.

Simulation of textile manufacturing processes for planning, scheduling, and quality control purposes

NASA Astrophysics Data System (ADS)

Cropper, A. E.; Wang, Z.

1995-08-01

Simulation, as a management information tool, has been applied to engineering manufacture and assembly operations. The application of the principles to textile manufacturing (fiber to fabric) is discussed. The particular problems and solutions in applying the simulation software package to the yarn production processes are discussed with an indication of how the software achieves the production schedule. The system appears to have application in planning, scheduling, and quality assurance. The latter being a result of the traceability possibilities through a process involving mixing and splitting of material.

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

Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.

This planning reference book is a document reflecting a Western Electricity Coordination Council (WECC) effort to put together multiple sources of information and provide a clear, systemic, comprehensive outline of the problems, both existing and anticipated; their impacts on the system; currently used and proposed solutions by the industry and research community; planning practices; new technologies, equipment, and standards; and expected future trends. This living (periodically updated) document could help WECC and other practicing engineers, especially the younger generation of engineers joining the workforce, to get familiar with a large variety of information related to the integration of variable resourcesmore » into the WECC system, bypassing in part the need for time-consuming information gathering and learning processes from more experienced engineers or from the literature.« less

Requirements model for an e-Health awareness portal

NASA Astrophysics Data System (ADS)

Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Nawi, Mohd Nasrun M.

2016-08-01

Requirements engineering is at the heart and foundation of software engineering process. Poor quality requirements inevitably lead to poor quality software solutions. Also, poor requirement modeling is tantamount to designing a poor quality product. So, quality assured requirements development collaborates fine with usable products in giving the software product the needed quality it demands. In the light of the foregoing, the requirements for an e-Ebola Awareness Portal were modeled with a good attention given to these software engineering concerns. The requirements for the e-Health Awareness Portal are modeled as a contribution to the fight against Ebola and helps in the fulfillment of the United Nation's Millennium Development Goal No. 6. In this study requirements were modeled using UML 2.0 modeling technique.

Practical Application of Model-based Programming and State-based Architecture to Space Missions

NASA Technical Reports Server (NTRS)

Horvath, Gregory A.; Ingham, Michel D.; Chung, Seung; Martin, Oliver; Williams, Brian

2006-01-01

Innovative systems and software engineering solutions are required to meet the increasingly challenging demands of deep-space robotic missions. While recent advances in the development of an integrated systems and software engineering approach have begun to address some of these issues, they are still at the core highly manual and, therefore, error-prone. This paper describes a task aimed at infusing MIT's model-based executive, Titan, into JPL's Mission Data System (MDS), a unified state-based architecture, systems engineering process, and supporting software framework. Results of the task are presented, including a discussion of the benefits and challenges associated with integrating mature model-based programming techniques and technologies into a rigorously-defined domain specific architecture.

Exploration on teaching reform of theory curriculum for engineering specialties

NASA Astrophysics Data System (ADS)

Zhang, Yan; Shen, Wei-min; Shen, Chang-yu; Li, Chen-xia; Jing, Xu-feng; Lou, Jun; Shi, Yan; Jin, Shang-zhong

2017-08-01

The orientation of talents cultivation for local colleges is to train engineering application-oriented talents, so the exploration and practice on teaching reform of theory curriculum was carried out. We restructured the knowledge units basing on numerical solution problems, and chose the software to build algorithm models for improving the analytical and designed ability. Relying on micro video lessons platform, the teacher-student interaction was expanded from class to outside. Also, we programmed new experimental homework, which was suited for process evaluation. The new teaching mode has achieved good effect, and the students' application ability was significantly improved.

Time evolution of pore system in lime - Pozzolana composites

NASA Astrophysics Data System (ADS)

Doleželová, Magdaléna; Čáchová, Monika; Scheinherrová, Lenka; Keppert, Martin

2017-11-01

The lime - pozzolana mortars and plasters are used in restoration works on building cultural heritage but these materials are also following the trend of energy - efficient solutions in civil engineering. Porosity and pore size distribution is one of crucial parameters influencing engineering properties of porous materials. The pore size distribution of lime based system is changing in time due to chemical processes occurring in the material. The present paper describes time evolution of pore system in lime - pozzolana composites; the obtained results are useful in prediction of performance of lime - pozzolana systems in building structures.

In vitro corrosion and cytocompatibility properties of nano-whisker hydroxyapatite coating on magnesium alloy for bone tissue engineering applications.

PubMed

Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

2015-03-17

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

User-friendly design approach for analog layout design

NASA Astrophysics Data System (ADS)

Li, Yongfu; Lee, Zhao Chuan; Tripathi, Vikas; Perez, Valerio; Ong, Yoong Seang; Hui, Chiu Wing

2017-03-01

Analog circuits are sensitives to the changes in the layout environment conditions, manufacturing processes, and variations. This paper presents analog verification flow with five types of analogfocused layout constraint checks to assist engineers in identifying any potential device mismatch and layout drawing mistakes. Compared to several solutions, our approach only requires layout design, which is sufficient to recognize all the matched devices. Our approach simplifies the data preparation and allows seamless integration into the layout environment with minimum disruption to the custom layout flow. Our user-friendly analog verification flow provides the engineer with more confident with their layouts quality.

In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

PubMed Central

Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

2015-01-01

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries. PMID:25789500

Electro fluido dynamic techniques to design instructive biomaterials for tissue engineering and drug delivery

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

Guarino, Vincenzo, E-mail: vguarino@unina.it; Altobelli, Rosaria; Cirillo, Valentina

A large variety of processes and tools is continuously investigated to discover new solutions to design instructive materials with controlled chemical, physical and biological properties for tissue engineering and drug delivery. Among them, electro fluido dynamic techniques (EFDTs) are emerging as an interesting strategy, based on highly flexible and low-cost processes, to revisit old biomaterial’s manufacturing approach by utilizing electrostatic forces as the driving force for the fabrication of 3D architectures with controlled physical and chemical functionalities to guide in vitro and in vivo cell activities. By a rational selection of polymer solution properties and process conditions, EFDTs allow tomore » produce fibres and/or particles at micro and/or nanometric size scale which may be variously assembled by tailored experimental setups, thus giving the chance to generate a plethora of different 3D devices able to incorporate biopolymers (i.e., proteins, polysaccharides) or active molecules (e.g., drugs) for different applications. Here, we focus on the optimization of basic EFDTs - namely electrospinning, electrospraying and electrodynamic atomization - to develop active platforms (i.e., monocomponent, protein and drug loaded scaffolds and µ-scaffolds) made of synthetic (PCL, PLGA) or natural (chitosan, alginate) polymers. In particular, we investigate how to set materials and process parameters to impart specific morphological, biochemical or physical cues to trigger all the fundamental cell–biomaterial and cell– cell cross-talking elicited during regenerative processes, in order to reproduce the complex microenvironment of native or pathological tissues.« less

Electro fluido dynamic techniques to design instructive biomaterials for tissue engineering and drug delivery

NASA Astrophysics Data System (ADS)

Guarino, Vincenzo; Altobelli, Rosaria; Cirillo, Valentina; Ambrosio, Luigi

2015-12-01

A large variety of processes and tools is continuously investigated to discover new solutions to design instructive materials with controlled chemical, physical and biological properties for tissue engineering and drug delivery. Among them, electro fluido dynamic techniques (EFDTs) are emerging as an interesting strategy, based on highly flexible and low-cost processes, to revisit old biomaterial's manufacturing approach by utilizing electrostatic forces as the driving force for the fabrication of 3D architectures with controlled physical and chemical functionalities to guide in vitro and in vivo cell activities. By a rational selection of polymer solution properties and process conditions, EFDTs allow to produce fibres and/or particles at micro and/or nanometric size scale which may be variously assembled by tailored experimental setups, thus giving the chance to generate a plethora of different 3D devices able to incorporate biopolymers (i.e., proteins, polysaccharides) or active molecules (e.g., drugs) for different applications. Here, we focus on the optimization of basic EFDTs - namely electrospinning, electrospraying and electrodynamic atomization - to develop active platforms (i.e., monocomponent, protein and drug loaded scaffolds and µ-scaffolds) made of synthetic (PCL, PLGA) or natural (chitosan, alginate) polymers. In particular, we investigate how to set materials and process parameters to impart specific morphological, biochemical or physical cues to trigger all the fundamental cell-biomaterial and cell- cell cross-talking elicited during regenerative processes, in order to reproduce the complex microenvironment of native or pathological tissues.

LDRD Final Report: Global Optimization for Engineering Science Problems

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

HART,WILLIAM E.

1999-12-01

For a wide variety of scientific and engineering problems the desired solution corresponds to an optimal set of objective function parameters, where the objective function measures a solution's quality. The main goal of the LDRD ''Global Optimization for Engineering Science Problems'' was the development of new robust and efficient optimization algorithms that can be used to find globally optimal solutions to complex optimization problems. This SAND report summarizes the technical accomplishments of this LDRD, discusses lessons learned and describes open research issues.

The Virtual Employment Test Bed: An Immersive Synthetic Environment Allows Engineers to Test and Evaluate Material Solutions

DTIC Science & Technology

2014-04-03

synthetic environment allows engineers to test and evaluate material solutions Robert DeMarco, MSBME; Gordon Cooke, MEME ; John Riedener, MSSE...ROBERT DEMARCO, MSBME, is a Project Lead Engineer and Certified LabVIEW Associate Developer. GORDON COOKE, MEME , is a Principal Investigator at the

Advanced Biofuels and Beyond: Chemistry Solutions for Propulsion and Production.

PubMed

Leitner, Walter; Klankermayer, Jürgen; Pischinger, Stefan; Pitsch, Heinz; Kohse-Höinghaus, Katharina

2017-05-08

Sustainably produced biofuels, especially when they are derived from lignocellulosic biomass, are being discussed intensively for future ground transportation. Traditionally, research activities focus on the synthesis process, while leaving their combustion properties to be evaluated by a different community. This Review adopts an integrative view of engine combustion and fuel synthesis, focusing on chemical aspects as the common denominator. It will be demonstrated that a fundamental understanding of the combustion process can be instrumental to derive design criteria for the molecular structure of fuel candidates, which can then be targets for the analysis of synthetic pathways and the development of catalytic production routes. With such an integrative approach to fuel design, it will be possible to improve systematically the entire system, spanning biomass feedstock, conversion process, fuel, engine, and pollutants with a view to improve the carbon footprint, increase efficiency, and reduce emissions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical modeling of consolidation processes in hydraulically deposited soils

NASA Astrophysics Data System (ADS)

Brink, Nicholas Robert

Hydraulically deposited soils are encountered in many common engineering applications including mine tailing and geotextile tube fills, though the consolidation process for such soils is highly nonlinear and requires the use of advanced numerical techniques to provide accurate predictions. Several commercially available finite element codes poses the ability to model soil consolidation, and it was the goal of this research to assess the ability of two of these codes, ABAQUS and PLAXIS, to model the large-strain, two-dimensional consolidation processes which occur in hydraulically deposited soils. A series of one- and two-dimensionally drained rectangular models were first created to assess the limitations of ABAQUS and PLAXIS when modeling consolidation of highly compressible soils. Then, geotextile tube and TSF models were created to represent actual scenarios which might be encountered in engineering practice. Several limitations were discovered, including the existence of a minimum preconsolidation stress below which numerical solutions become unstable.

Requirements Flowdown for Prognostics and Health Management

NASA Technical Reports Server (NTRS)

Goebel, Kai; Saxena, Abhinav; Roychoudhury, Indranil; Celaya, Jose R.; Saha, Bhaskar; Saha, Sankalita

2012-01-01

Prognostics and Health Management (PHM) principles have considerable promise to change the game of lifecycle cost of engineering systems at high safety levels by providing a reliable estimate of future system states. This estimate is a key for planning and decision making in an operational setting. While technology solutions have made considerable advances, the tie-in into the systems engineering process is lagging behind, which delays fielding of PHM-enabled systems. The derivation of specifications from high level requirements for algorithm performance to ensure quality predictions is not well developed. From an engineering perspective some key parameters driving the requirements for prognostics performance include: (1) maximum allowable Probability of Failure (PoF) of the prognostic system to bound the risk of losing an asset, (2) tolerable limits on proactive maintenance to minimize missed opportunity of asset usage, (3) lead time to specify the amount of advanced warning needed for actionable decisions, and (4) required confidence to specify when prognosis is sufficiently good to be used. This paper takes a systems engineering view towards the requirements specification process and presents a method for the flowdown process. A case study based on an electric Unmanned Aerial Vehicle (e-UAV) scenario demonstrates how top level requirements for performance, cost, and safety flow down to the health management level and specify quantitative requirements for prognostic algorithm performance.

Recent advances and state-of-the-art strategies in strain and process engineering for biobutanol production by Clostridium acetobutylicum.

PubMed

Xue, Chuang; Zhao, Jingbo; Chen, Lijie; Yang, Shang-Tian; Bai, Fengwu

Butanol as an advanced biofuel has gained great attention due to its environmental benefits and superior properties compared to ethanol. However, the cost of biobutanol production via conventional acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum is not economically competitive, which has hampered its industrial application. The strain performance and downstream process greatly impact the economics of biobutanol production. Although various engineered strains with carefully orchestrated metabolic and sporulation-specific pathways have been developed, none of them is ideal for industrial biobutanol production. For further strain improvement, it is necessary to develop advanced genome editing tools and a deep understanding of cellular functioning of genes in metabolic and regulatory pathways. Processes with integrated product recovery can increase fermentation productivity by continuously removing inhibitory products while generating butanol (ABE) in a concentrated solution. In this review, we provide an overview of recent advances in C. acetobutylicum strain engineering and process development focusing on in situ product recovery. With deep understanding of systematic cellular bioinformatics, the exploration of state-of-the-art genome editing tools such as CRISPR-Cas for targeted gene knock-out and knock-in would play a vital role in Clostridium cell engineering for biobutanol production. Developing advanced hybrid separation processes for in situ butanol recovery, which will be discussed with a detailed comparison of advantages and disadvantages of various recovery techniques, is also imperative to the economical development of biobutanol. Copyright © 2017 Elsevier Inc. All rights reserved.

Engineering and Scientific Applications: Using MatLab(Registered Trademark) for Data Processing and Visualization

NASA Technical Reports Server (NTRS)

Sen, Syamal K.; Shaykhian, Gholam Ali

2011-01-01

MatLab(TradeMark)(MATrix LABoratory) is a numerical computation and simulation tool that is used by thousands Scientists and Engineers in many countries. MatLab does purely numerical calculations, which can be used as a glorified calculator or interpreter programming language; its real strength is in matrix manipulations. Computer algebra functionalities are achieved within the MatLab environment using "symbolic" toolbox. This feature is similar to computer algebra programs, provided by Maple or Mathematica to calculate with mathematical equations using symbolic operations. MatLab in its interpreter programming language form (command interface) is similar with well known programming languages such as C/C++, support data structures and cell arrays to define classes in object oriented programming. As such, MatLab is equipped with most of the essential constructs of a higher programming language. MatLab is packaged with an editor and debugging functionality useful to perform analysis of large MatLab programs and find errors. We believe there are many ways to approach real-world problems; prescribed methods to ensure foregoing solutions are incorporated in design and analysis of data processing and visualization can benefit engineers and scientist in gaining wider insight in actual implementation of their perspective experiments. This presentation will focus on data processing and visualizations aspects of engineering and scientific applications. Specifically, it will discuss methods and techniques to perform intermediate-level data processing covering engineering and scientific problems. MatLab programming techniques including reading various data files formats to produce customized publication-quality graphics, importing engineering and/or scientific data, organizing data in tabular format, exporting data to be used by other software programs such as Microsoft Excel, data presentation and visualization will be discussed.

Stable colloids in molten inorganic salts

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

Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B.

2017-02-15

A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes1, 2, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other2. Electrostatic stabilization3, 4 of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solventsmore » with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains2, 5. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute–solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute–solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.« less

AST/R–BASED WATER REUSE AS A PART OF THE TOTAL WATER SOLUTION FOR WATER-STRESSED REGIONS: AN OVERVIEW OF ENGINEERING PRACTICE AND REGULATORY PROSPECTIVE

EPA Science Inventory

Water supply and demand are increasingly unbalanced in many parts of the world. To address the imbalance, the total water solution methodology simultaneously considers regulatory, engineering, environmental and economic factors to optimize risk management solutions for an entire...

AST/R BASED WATER REUSE AS A PART OF THE TOTAL WATER SOLUTION FOR WATER-STRESSED REGIONS: AN OVERVIEW OF ENGINEERING PRACTICE AND REGULATORY PROSPECTIVE

EPA Science Inventory

Water supply and demand are increasingly unbalanced in many parts of the world. To address the imbalance, the total water solution methodology simultaneously considers regulatory, engineering, environmental and economic factors to optimize risk management solutions for an entire ...

HSR combustion analytical research

NASA Technical Reports Server (NTRS)

Nguyen, H. Lee

1992-01-01

Increasing the pressure and temperature of the engines of a new generation of supersonic airliners increases the emissions of nitrogen oxides (NO(x)) to a level that would have an adverse impact on the Earth's protective ozone layer. In the process of evolving and implementing low emissions combustor technologies, NASA LeRC has pursued a combustion analysis code program to guide combustor design processes, to identify potential concepts of the greatest promise, and to optimize them at low cost, with short turnaround time. The computational analyses are evaluated at actual engine operating conditions. The approach is to upgrade and apply advanced computer programs for gas turbine applications. Efforts were made in further improving the code capabilities for modeling the physics and the numerical methods of solution. Then test cases and measurements from experiments are used for code validation.

Superstructure-based Design and Optimization of Batch Biodiesel Production Using Heterogeneous Catalysts

NASA Astrophysics Data System (ADS)

Nuh, M. Z.; Nasir, N. F.

2017-08-01

Biodiesel as a fuel comprised of mono alkyl esters of long chain fatty acids derived from renewable lipid feedstock, such as vegetable oil and animal fat. Biodiesel production is complex process which need systematic design and optimization. However, no case study using the process system engineering (PSE) elements which are superstructure optimization of batch process, it involves complex problems and uses mixed-integer nonlinear programming (MINLP). The PSE offers a solution to complex engineering system by enabling the use of viable tools and techniques to better manage and comprehend the complexity of the system. This study is aimed to apply the PSE tools for the simulation of biodiesel process and optimization and to develop mathematical models for component of the plant for case A, B, C by using published kinetic data. Secondly, to determine economic analysis for biodiesel production, focusing on heterogeneous catalyst. Finally, the objective of this study is to develop the superstructure for biodiesel production by using heterogeneous catalyst. The mathematical models are developed by the superstructure and solving the resulting mixed integer non-linear model and estimation economic analysis by using MATLAB software. The results of the optimization process with the objective function of minimizing the annual production cost by batch process from case C is 23.2587 million USD. Overall, the implementation a study of process system engineering (PSE) has optimized the process of modelling, design and cost estimation. By optimizing the process, it results in solving the complex production and processing of biodiesel by batch.

Gel spinning of silk tubes for tissue engineering

PubMed Central

Lovett, Michael; Cannizzaro, Christopher; Vunjak-Novakovic, Gordana; Kaplan, David L.

2011-01-01

Tubular vessels for tissue engineering are typically fabricated using a molding, dipping, or electrospinning technique. While these techniques provide some control over inner and outer diameters of the tube, they lack the ability to align the polymers or fibers of interest throughout the tube. This is an important aspect of biomaterial composite structure and function for mechanical and biological impact of tissue outcomes. We present a novel aqueous process system to spin tubes from biopolymers and proteins such as silk fibroin. Using silk as an example, this method of winding an aqueous solution around a reciprocating rotating mandrel offers substantial improvement in the control of the tube properties, specifically with regard to winding pattern, tube porosity, and composite features. Silk tube properties are further controlled via different post-spinning processing mechanisms such as methanol-treatment, air-drying, and lyophilization. This approach to tubular scaffold manufacture offers numerous tissue engineering applications such as complex composite biomaterial matrices, blood vessel grafts and nerve guides, among others. PMID:18801570

DEM GPU studies of industrial scale particle simulations for granular flow civil engineering applications

NASA Astrophysics Data System (ADS)

Pizette, Patrick; Govender, Nicolin; Wilke, Daniel N.; Abriak, Nor-Edine

2017-06-01

The use of the Discrete Element Method (DEM) for industrial civil engineering industrial applications is currently limited due to the computational demands when large numbers of particles are considered. The graphics processing unit (GPU) with its highly parallelized hardware architecture shows potential to enable solution of civil engineering problems using discrete granular approaches. We demonstrate in this study the pratical utility of a validated GPU-enabled DEM modeling environment to simulate industrial scale granular problems. As illustration, the flow discharge of storage silos using 8 and 17 million particles is considered. DEM simulations have been performed to investigate the influence of particle size (equivalent size for the 20/40-mesh gravel) and induced shear stress for two hopper shapes. The preliminary results indicate that the shape of the hopper significantly influences the discharge rates for the same material. Specifically, this work shows that GPU-enabled DEM modeling environments can model industrial scale problems on a single portable computer within a day for 30 seconds of process time.

Introduction to the Navigation Team: Johnson Space Center EG6 Internship

NASA Technical Reports Server (NTRS)

Gualdoni, Matthew

2017-01-01

The EG6 navigation team at NASA Johnson Space Center, like any team of engineers, interacts with the engineering process from beginning to end; from exploring solutions to a problem, to prototyping and studying the implementations, all the way to polishing and verifying a final flight-ready design. This summer, I was privileged enough to gain exposure to each of these processes, while also getting to truly experience working within a team of engineers. My summer can be broken up into three projects: i) Initial study and prototyping: investigating a manual navigation method that can be utilized onboard Orion in the event of catastrophic failure of navigation systems; ii) Finalizing and verifying code: altering a software routine to improve its robustness and reliability, as well as designing unit tests to verify its performance; and iii) Development of testing equipment: assisting in developing and integrating of a high-fidelity testbed to verify the performance of software and hardware.

Bioengineering Solutions for Manufacturing Challenges in CAR T Cells

PubMed Central

Piscopo, Nicole J.; Mueller, Katherine P.; Das, Amritava; Hematti, Peiman; Murphy, William L.; Palecek, Sean P.; Capitini, Christian M.

2017-01-01

The next generation of therapeutic products to be approved for the clinic is anticipated to be cell therapies, termed “living drugs” for their capacity to dynamically and temporally respond to changes during their production ex vivo and after their administration in vivo. Genetically engineered chimeric antigen receptor (CAR) T cells have rapidly developed into powerful tools to harness the power of immune system manipulation against cancer. Regulatory agencies are beginning to approve CAR T cell therapies due to their striking efficacy in treating some hematological malignancies. However, the engineering and manufacturing of such cells remains a challenge for widespread adoption of this technology. Bioengineering approaches including biomaterials, synthetic biology, metabolic engineering, process control and automation, and in vitro disease modeling could offer promising methods to overcome some of these challenges. Here, we describe the manufacturing process of CAR T cells, highlighting potential roles for bioengineers to partner with biologists and clinicians to advance the manufacture of these complex cellular products under rigorous regulatory and quality control. PMID:28840981

Issues and Strategies in Solving Multidisciplinary Optimization Problems

NASA Technical Reports Server (NTRS)

Patnaik, Surya

2013-01-01

Optimization research at NASA Glenn Research Center has addressed the design of structures, aircraft and airbreathing propulsion engines. The accumulated multidisciplinary design activity is collected under a testbed entitled COMETBOARDS. Several issues were encountered during the solution of the problems. Four issues and the strategies adapted for their resolution are discussed. This is followed by a discussion on analytical methods that is limited to structural design application. An optimization process can lead to an inefficient local solution. This deficiency was encountered during design of an engine component. The limitation was overcome through an augmentation of animation into optimization. Optimum solutions obtained were infeasible for aircraft and airbreathing propulsion engine problems. Alleviation of this deficiency required a cascading of multiple algorithms. Profile optimization of a beam produced an irregular shape. Engineering intuition restored the regular shape for the beam. The solution obtained for a cylindrical shell by a subproblem strategy converged to a design that can be difficult to manufacture. Resolution of this issue remains a challenge. The issues and resolutions are illustrated through a set of problems: Design of an engine component, Synthesis of a subsonic aircraft, Operation optimization of a supersonic engine, Design of a wave-rotor-topping device, Profile optimization of a cantilever beam, and Design of a cylindrical shell. This chapter provides a cursory account of the issues. Cited references provide detailed discussion on the topics. Design of a structure can also be generated by traditional method and the stochastic design concept. Merits and limitations of the three methods (traditional method, optimization method and stochastic concept) are illustrated. In the traditional method, the constraints are manipulated to obtain the design and weight is back calculated. In design optimization, the weight of a structure becomes the merit function with constraints imposed on failure modes and an optimization algorithm is used to generate the solution. Stochastic design concept accounts for uncertainties in loads, material properties, and other parameters and solution is obtained by solving a design optimization problem for a specified reliability. Acceptable solutions can be produced by all the three methods. The variation in the weight calculated by the methods was found to be modest. Some variation was noticed in designs calculated by the methods. The variation may be attributed to structural indeterminacy. It is prudent to develop design by all three methods prior to its fabrication. The traditional design method can be improved when the simplified sensitivities of the behavior constraint is used. Such sensitivity can reduce design calculations and may have a potential to unify the traditional and optimization methods. Weight versus reliability traced out an inverted-S-shaped graph. The center of the graph corresponded to mean valued design. A heavy design with weight approaching infinity could be produced for a near-zero rate of failure. Weight can be reduced to a small value for a most failure-prone design. Probabilistic modeling of load and material properties remained a challenge.

Planning, Implementation and Optimization of Future space Missions using an Immersive Visualization Environement (IVE) Machine

NASA Astrophysics Data System (ADS)

Harris, E.

Planning, Implementation and Optimization of Future Space Missions using an Immersive Visualization Environment (IVE) Machine E. N. Harris, Lockheed Martin Space Systems, Denver, CO and George.W. Morgenthaler, U. of Colorado at Boulder History: A team of 3-D engineering visualization experts at the Lockheed Martin Space Systems Company have developed innovative virtual prototyping simulation solutions for ground processing and real-time visualization of design and planning of aerospace missions over the past 6 years. At the University of Colorado, a team of 3-D visualization experts are developing the science of 3-D visualization and immersive visualization at the newly founded BP Center for Visualization, which began operations in October, 2001. (See IAF/IAA-01-13.2.09, "The Use of 3-D Immersive Visualization Environments (IVEs) to Plan Space Missions," G. A. Dorn and G. W. Morgenthaler.) Progressing from Today's 3-D Engineering Simulations to Tomorrow's 3-D IVE Mission Planning, Simulation and Optimization Techniques: 3-D (IVEs) and visualization simulation tools can be combined for efficient planning and design engineering of future aerospace exploration and commercial missions. This technology is currently being developed and will be demonstrated by Lockheed Martin in the (IVE) at the BP Center using virtual simulation for clearance checks, collision detection, ergonomics and reach-ability analyses to develop fabrication and processing flows for spacecraft and launch vehicle ground support operations and to optimize mission architecture and vehicle design subject to realistic constraints. Demonstrations: Immediate aerospace applications to be demonstrated include developing streamlined processing flows for Reusable Space Transportation Systems and Atlas Launch Vehicle operations and Mars Polar Lander visual work instructions. Long-range goals include future international human and robotic space exploration missions such as the development of a Mars Reconnaissance Orbiter and Lunar Base construction scenarios. Innovative solutions utilizing Immersive Visualization provide the key to streamlining the mission planning and optimizing engineering design phases of future aerospace missions.

A Return to Innovative Engineering Design, Critical Thinking and Systems Engineering

NASA Technical Reports Server (NTRS)

Camarda, Charles J.

2007-01-01

I believe we are facing a critical time where innovative engineering design is of paramount importance to the success of our aerospace industry. However, the very qualities and attributes necessary for enhancing, educating, and mentoring a creative spirit are in decline in important areas. The importance of creativity and innovation in this country was emphasized by a special edition of the Harvard Business Review OnPoint entitled: "The Creative Company" which compiled a series of past and present articles on the subject of creativity and innovation and stressed its importance to our national economy. There is also a recognition of a lack of engineering, critical thinking and problem-solving skills in our education systems and a trend toward trying to enhance those skills by developing K-12 educational programs such as Project Lead the Way, "Science for All Americans", Benchmarks 2061 , etc. In addition, with respect to spacecraft development, we have a growing need for young to mid-level engineers with appropriate experience and skills in spacecraft design, development, analysis, testing, and systems engineering. As the Director of Engineering at NASA's Johnson Space Center, I realized that sustaining engineering support of an operational human spacecraft such as the Space Shuttle is decidedly different than engineering design and development skills necessary for designing a new spacecraft such as the Crew Exploration Vehicle of the Constellation Program. We learned a very important lesson post Columbia in that the Space Shuttle is truly an experimental and not an operational vehicle and the strict adherence to developed rules and processes and chains of command of an inherently bureaucratic organizational structure will not protect us from a host of known unknowns let alone unknown unknowns. There are no strict rules, processes, or procedures for understanding anomalous results of an experiment, anomalies with an experimental spacecraft like Shuttle, or in the conceptual design of a spacecraft. Engineering design is as much an art as it is a science. The critical thinking skills necessary to uncover lurking problems in an experimental design and creatively develop solutions are some of the same skills necessary to design a new spacecraft. Thus, I believe engineers unfamiliar with or removed from design and development need time to transition and develop the required skill set to be effective spacecraft designers. I believe the creative process necessary in design can be enhanced and even taught as early as grades K-12 and should continue to be nurtured and developed at the university level and beyond. I am going to present a strategy for developing learning teams to address complex multidisciplinary problems and to creatively develop solutions to those problems rapidly at minimal cost. I will frame a real problem, the development of on-orbit thermal protection system repair of the Space Shuttle, and step through the series of skills necessary to enhance the creative process. The case study I will illustrate is based on a real project, the R&D Reinforced Carbon-Carbon (RCC) Repair Team's development of on-orbit repair concepts for damaged Space Shuttle RCC nose cap and/or leading edges.

Programmable lithography engine (ProLE) grid-type supercomputer and its applications

NASA Astrophysics Data System (ADS)

Petersen, John S.; Maslow, Mark J.; Gerold, David J.; Greenway, Robert T.

2003-06-01

There are many variables that can affect lithographic dependent device yield. Because of this, it is not enough to make optical proximity corrections (OPC) based on the mask type, wavelength, lens, illumination-type and coherence. Resist chemistry and physics along with substrate, exposure, and all post-exposure processing must be considered too. Only a holistic approach to finding imaging solutions will accelerate yield and maximize performance. Since experiments are too costly in both time and money, accomplishing this takes massive amounts of accurate simulation capability. Our solution is to create a workbench that has a set of advanced user applications that utilize best-in-class simulator engines for solving litho-related DFM problems using distributive computing. Our product, ProLE (Programmable Lithography Engine), is an integrated system that combines Petersen Advanced Lithography Inc."s (PAL"s) proprietary applications and cluster management software wrapped around commercial software engines, along with optional commercial hardware and software. It uses the most rigorous lithography simulation engines to solve deep sub-wavelength imaging problems accurately and at speeds that are several orders of magnitude faster than current methods. Specifically, ProLE uses full vector thin-mask aerial image models or when needed, full across source 3D electromagnetic field simulation to make accurate aerial image predictions along with calibrated resist models;. The ProLE workstation from Petersen Advanced Lithography, Inc., is the first commercial product that makes it possible to do these intensive calculations at a fraction of a time previously available thus significantly reducing time to market for advance technology devices. In this work, ProLE is introduced, through model comparison to show why vector imaging and rigorous resist models work better than other less rigorous models, then some applications of that use our distributive computing solution are shown. Topics covered describe why ProLE solutions are needed from an economic and technical aspect, a high level discussion of how the distributive system works, speed benchmarking, and finally, a brief survey of applications including advanced aberrations for lens sensitivity and flare studies, optical-proximity-correction for a bitcell and an application that will allow evaluation of the potential of a design to have systematic failures during fabrication.

Application of the Undifferenced GNSS Precise Positioning in Determining Coordinates in National Reference Frames

NASA Astrophysics Data System (ADS)

Krzan, Grzegorz; Stępniak, Katarzyna

2017-09-01

In high-accuracy positioning using GNSS, the most common solution is still relative positioning using double-difference observations of dual-frequency measurements. An increasingly popular alternative to relative positioning are undifferenced approaches, which are designed to make full use of modern satellite systems and signals. Positions referenced to global International Terrestrial Reference Frame (ITRF2008) obtained from Precise Point Positioning (PPP) or Undifferenced (UD) network solutions have to be transformed to national (regional) reference frame, which introduces additional bases related to the transformation process. In this paper, satellite observations from two test networks using different observation time series were processed. The first test concerns the positioning accuracy from processing one year of dual-frequency GPS observations from 14 EUREF Permanent Network (EPN) stations using NAPEOS 3.3.1 software. The results were transformed into a national reference frame (PL-ETRF2000) and compared to positions from an EPN cumulative solution, which was adopted as the true coordinates. Daily observations were processed using PPP and UD multi-station solutions to determine the final accuracy resulting from satellite positioning, the transformation to national coordinate systems and Eurasian intraplate plate velocities. The second numerical test involved similar processing strategies of post-processing carried out using different observation time series (30 min., 1 hour, 2 hours, daily) and different classes of GNSS receivers. The centimeter accuracy of results presented in the national coordinate system satisfies the requirements of many surveying and engineering applications.

The New Global Responsibilities of Engineers Create Challenges for Engineering Education

ERIC Educational Resources Information Center

Fuchs, Willi

2012-01-01

Modern societies aim to solve the global challenges of the 21st century with sustainable solutions such as resource efficiency, use of renewable energy sources and recycling. Engineers are called upon to create the cutting edge technological solutions that can help to address these challenges. In developed as well as in developing countries,…

Providing Formative Assessment to Students Solving Multipath Engineering Problems with Complex Arrangements of Interacting Parts: An Intelligent Tutor Approach

ERIC Educational Resources Information Center

Steif, Paul S.; Fu, Luoting; Kara, Levent Burak

2016-01-01

Problems faced by engineering students involve multiple pathways to solution. Students rarely receive effective formative feedback on handwritten homework. This paper examines the potential for computer-based formative assessment of student solutions to multipath engineering problems. In particular, an intelligent tutor approach is adopted and…

Digitalizing the Circular Economy

NASA Astrophysics Data System (ADS)

Reuter, Markus A.

2016-12-01

Metallurgy is a key enabler of a circular economy (CE), its digitalization is the metallurgical Internet of Things (m-IoT). In short: Metallurgy is at the heart of a CE, as metals all have strong intrinsic recycling potentials. Process metallurgy, as a key enabler for a CE, will help much to deliver its goals. The first-principles models of process engineering help quantify the resource efficiency (RE) of the CE system, connecting all stakeholders via digitalization. This provides well-argued and first-principles environmental information to empower a tax paying consumer society, policy, legislators, and environmentalists. It provides the details of capital expenditure and operational expenditure estimates. Through this path, the opportunities and limits of a CE, recycling, and its technology can be estimated. The true boundaries of sustainability can be determined in addition to the techno-economic evaluation of RE. The integration of metallurgical reactor technology and systems digitally, not only on one site but linking different sites globally via hardware, is the basis for describing CE systems as dynamic feedback control loops, i.e., the m-IoT. It is the linkage of the global carrier metallurgical processing system infrastructure that maximizes the recovery of all minor and technology elements in its associated refining metallurgical infrastructure. This will be illustrated through the following: (1) System optimization models for multimetal metallurgical processing. These map large-scale m-IoT systems linked to computer-aided design tools of the original equipment manufacturers and then establish a recycling index through the quantification of RE. (2) Reactor optimization and industrial system solutions to realize the "CE (within a) Corporation—CEC," realizing the CE of society. (3) Real-time measurement of ore and scrap properties in intelligent plant structures, linked to the modeling, simulation, and optimization of industrial extractive process metallurgical reactors and plants for both primary and secondary materials processing. (4) Big-data analysis and process control of industrial metallurgical systems, processes, and reactors by the application of, among others, artificial intelligence techniques and computer-aided engineering. (5) Minerals processing and process metallurgical theory, technology, simulation, and analytical tools, which are all key enablers of the CE. (6) Visualizing the results of all the tools used for estimating the RE of the CE system in a form that the consumer and general public can understand. (7) The smart integration of tools and methods that quantify RE and deliver sustainable solutions, named in this article as circular economy engineering. In view of space limitations, this message will be colored in by various publications also with students and colleagues, referring to (often commercial) software that acts as a conduit to capture and formalize the research of the large body of work in the literature by distinguished metallurgical engineers and researchers and realized in innovative industrial solutions. The author stands humbly on the shoulders of these developments and their distinguished developers. This award lecture article implicitly also refers to work done while working for Ausmelt (Australia), Outotec (Finland and Australia), Mintek (South Africa), and Anglo American Corporation (South Africa), honoring the many colleagues the author has worked with over the years.

Fostering Innovation in the Manufacturing Sector through R&D Consortia

NASA Astrophysics Data System (ADS)

McKittrick, M.

2017-12-01

In the U.S. Department of Energy, the Advanced Manufacturing Office (AMO) has the mission to catalyze research, development and adoption of energy-related advanced manufacturing technologies and practices to drive U.S. economic competitiveness and energy productivity. Within strategic areas of manufacturing, AMO brings together manufacturers, suppliers, institutes of higher education, national laboratories, and state and local governments in public-private R&D consortia to accelerate technology innovation. One such R&D Consortia is the Critical Materials Institute (CMI), established in 2013 and led by Ames Laboratory. CMI is a sustained, multidisciplinary effort to develop solutions across the materials lifecycle of materials essential to clean energy technologies and manufacturing, as well as reduce the impact of supply chain disruptions associated with these valuable resources. By bringing together scientists and engineers from diverse disciplines, CMI is addressing challenges in critical materials, including mineral processing, manufacture, substitution, efficient use, and end-of-life recycling; integrating scientific research, engineering innovation, manufacturing and process improvements; and developing a holistic solution to the materials challenges facing the nation. It includes expertise from four national laboratories, seven universities, and ten industry partners to minimize materials criticality as an impediment to the commercialization of clean energy technologies.

Dynamics of Fluids and Transport in Fractured Rock

NASA Astrophysics Data System (ADS)

Faybishenko, Boris; Witherspoon, Paul A.; Gale, John

How to characterize fluid flow, heat, and chemical transport in geologic media remains a central challenge for geo-scientists and engineers worldwide. Investigations of fluid flow and transport within rock relate to such fundamental and applied problems as environmental remediation; nonaqueous phase liquid (NAPL) transport; exploitation of oil, gas, and geothermal resources; disposal of spent nuclear fuel; and geotechnical engineering. It is widely acknowledged that fractures in unsaturated-saturated rock can play a major role in solute transport from the land surface to underlying aquifers. It is also evident that general issues concerning flow and transport predictions in subsurface fractured zones can be resolved in a practical manner by integrating investigations into the physical nature of flow in fractures, developing relevant mathematical models and modeling approaches, and collecting site characterization data. Because of the complexity of flow and transport processes in most fractured rock flow problems, it is not yet possible to develop models directly from first principles. One reason for this is the presence of episodic, preferential water seepage and solute transport, which usually proceed more rapidly than expected from volume-averaged and time-averaged models. However, the physics of these processes is still known.

Design the Cost Approach in Trade-Off's for Structural Components, Illustrated on the Baseline Selection of the Engine Thrust Frame of Ariane 5 ESC-B

NASA Astrophysics Data System (ADS)

Appolloni, L.; Juhls, A.; Rieck, U.

2002-01-01

Designing for value is one of the very actual upcoming methods for design optimization, which broke into the domain of aerospace engineering in the late 90's. In the frame of designing for value two main design philosophies exist: Design For Cost and Design To Cost. Design To Cost is the iterative redesign of a project until the content of the project meets a given budget. Designing For Cost is the conscious use of engineering process technology to reduce life cycle cost while satisfying, and hopefully exceeding, customer demands. The key to understanding cost, and hence to reducing cost, is the ability to measure cost accurately and to allocate it appropriately to products. Only then can intelligent decisions be made. Therefore the necessity of new methods as "Design For Value" or "Design For Competitiveness", set up with a generally multidisciplinary approach to find an optimized technical solution driven by many parameters, depending on the mission scenario and the customer/market needs. Very often three, but not more than five parametric drivers are sufficient. The more variable exist, the higher is in fact the risk to find just a sub-optimized local and not the global optimum, and the less robust is the found solution against change of input parameters. When the main parameters for optimization have been identified, the system engineer has to communicate them to all design engineers, who shall take care of these assessment variables during the entire design and decision process. The design process which has taken to the definition of the feasible structural concepts for the Engine Thrust Frame of the Ariane 5 Upper Cryogenic Stage ESC-B follows these most actual design philosophy methodologies, and combines a design for cost approach, to a design to cost optimization loop. Ariane 5 is the first member of a family of heavy-lift launchers. It aims to evolve into a family of launchers that responds to the space transportation challenges of the 21st century. New upper stages, along with modifications to the main cryogenic stage and solid boosters, will increase performance and meet demands of a changing market. A two-steps approach was decided for future developments of the launcher upper stage, in order to increase the payload lift capability of Ariane 5. The first step ESC-A is scheduled for first launch in 2002. As later step ESC-B shall grow up to 12 tons in GTO orbit, with multiple restart capability, i.e. re-ignitable engine. Ariane 5 ESC-B first flight is targeted for 2006. It will be loaded with 28 metric tons of liquid oxygen and liquid hydrogen and powered by a new expander cycle engine "Vinci". The Vinci engine will be connected to the tanks of the ESC-B stage via the structure named from the designers ETF, or Engine Thrust Frame. In order to develop a design concept for the ETF component a trade off was performed, based on the most modern system engineering methodologies. This paper will describe the basis of the system engineering approach in the design to cost process, and illustrate such approach as it has been applied during the trade off for the baseline selection of the Engine Thrust Frame of Ariane 5 ESC-B.

Solid state light engines for bioanalytical instruments and biomedical devices

NASA Astrophysics Data System (ADS)

Jaffe, Claudia B.; Jaffe, Steven M.

2010-02-01

Lighting subsystems to drive 21st century bioanalysis and biomedical diagnostics face stringent requirements. Industrywide demands for speed, accuracy and portability mean illumination must be intense as well as spectrally pure, switchable, stable, durable and inexpensive. Ideally a common lighting solution could service these needs for numerous research and clinical applications. While this is a noble objective, the current technology of arc lamps, lasers, LEDs and most recently light pipes have intrinsic spectral and angular traits that make a common solution untenable. Clearly a hybrid solution is required to service the varied needs of the life sciences. Any solution begins with a critical understanding of the instrument architecture and specifications for illumination regarding power, illumination area, illumination and emission wavelengths and numerical aperture. Optimizing signal to noise requires careful optimization of these parameters within the additional constraints of instrument footprint and cost. Often the illumination design process is confined to maximizing signal to noise without the ability to adjust any of the above parameters. A hybrid solution leverages the best of the existing lighting technologies. This paper will review the design process for this highly constrained, but typical optical optimization scenario for numerous bioanalytical instruments and biomedical devices.

Clinical Immersion: An Approach for Fostering Cross-disciplinary Communication and Innovation in Nursing and Engineering Students.

PubMed

Geist, Melissa J; Sanders, Robby; Harris, Kevin; Arce-Trigatti, Andrea; Hitchcock-Cass, Cary

2018-05-24

A faculty team from nursing and chemical engineering developed a course that brought together students from each discipline for cross-disciplinary, team-based clinical immersion and collaboration. Health care processes and devices are rapidly changing, and nurses are uniquely positioned to be bedside innovators to improve patient care delivery. During each clinical immersion, the student teams rotated through various hospital units where they identified problems and worked together in the university's makerspace (iMaker Space) to design and build prototypes to improve health outcomes. Data from the Critical thinking Assessment Test provided evidence of gains in critical-thinking and problem-solving skills, while the problems identified in the clinical setting and prototypes developed demonstrated the impact of bringing nursing and engineering students together to design innovations. When challenged to identify authentic problems during their clinical immersion, the teams of nursing and engineering students proposed creative solutions and developed commercially viable prototypes.

Composite Properties of Polyimide Resins Made From "Salt-Like" Solution Precursors

NASA Technical Reports Server (NTRS)

Cano, Roberto J.; Weiser, Erik S.; SaintClair, Terry L.; Echigo, Yoshiaki; Kaneshiro, Hisayasu

1997-01-01

Recent work in high temperature materials at NASA Langley Research Center (LaRC (trademark)) have led to the development of new polyimide resin systems with very attractive properties. The majority of the work done with these resin systems has concentrated on determining engineering mechanical properties of composites prepared from a poly(amide acid) precursor. Three NASA Langley-developed polyimide matrix resins, LaRC (trademark) -IA, LaRC (trademark) -IAX, and LaRC (trademark) -8515, were produced via a salt-like process developed by Unitika Ltd. The 'salt-like' solutions (sixty-five percent solids in NMP) were prepregged onto Hexcel IM7 carbon fiber using the NASA LaRC Multipurpose Tape Machine. Process parameters were determined and composite panels fabricated. Mechanical properties are presented for these three intermediate modulus carbon fiber/polyimide matrix composites and compared to existing data on the same polyimide resin systems and IM7 carbon fiber manufactured via poly(amide acid) solutions (thirty-five percent solids in NMP). This work studies the effects of varying the synthetic route on the processing and mechanical properties of polyimide composites.

Scientific discovery as a combinatorial optimisation problem: How best to navigate the landscape of possible experiments?

PubMed Central

Kell, Douglas B

2012-01-01

A considerable number of areas of bioscience, including gene and drug discovery, metabolic engineering for the biotechnological improvement of organisms, and the processes of natural and directed evolution, are best viewed in terms of a ‘landscape’ representing a large search space of possible solutions or experiments populated by a considerably smaller number of actual solutions that then emerge. This is what makes these problems ‘hard’, but as such these are to be seen as combinatorial optimisation problems that are best attacked by heuristic methods known from that field. Such landscapes, which may also represent or include multiple objectives, are effectively modelled in silico, with modern active learning algorithms such as those based on Darwinian evolution providing guidance, using existing knowledge, as to what is the ‘best’ experiment to do next. An awareness, and the application, of these methods can thereby enhance the scientific discovery process considerably. This analysis fits comfortably with an emerging epistemology that sees scientific reasoning, the search for solutions, and scientific discovery as Bayesian processes. PMID:22252984

Scientific discovery as a combinatorial optimisation problem: how best to navigate the landscape of possible experiments?

PubMed

Kell, Douglas B

2012-03-01

A considerable number of areas of bioscience, including gene and drug discovery, metabolic engineering for the biotechnological improvement of organisms, and the processes of natural and directed evolution, are best viewed in terms of a 'landscape' representing a large search space of possible solutions or experiments populated by a considerably smaller number of actual solutions that then emerge. This is what makes these problems 'hard', but as such these are to be seen as combinatorial optimisation problems that are best attacked by heuristic methods known from that field. Such landscapes, which may also represent or include multiple objectives, are effectively modelled in silico, with modern active learning algorithms such as those based on Darwinian evolution providing guidance, using existing knowledge, as to what is the 'best' experiment to do next. An awareness, and the application, of these methods can thereby enhance the scientific discovery process considerably. This analysis fits comfortably with an emerging epistemology that sees scientific reasoning, the search for solutions, and scientific discovery as Bayesian processes. Copyright © 2012 WILEY Periodicals, Inc.

Challenges Facing Design and Analysis Tools

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Broduer, Steve (Technical Monitor)

2001-01-01

The design and analysis of future aerospace systems will strongly rely on advanced engineering analysis tools used in combination with risk mitigation procedures. The implications of such a trend place increased demands on these tools to assess off-nominal conditions, residual strength, damage propagation, and extreme loading conditions in order to understand and quantify these effects as they affect mission success. Advances in computer hardware such as CPU processing speed, memory, secondary storage, and visualization provide significant resources for the engineer to exploit in engineering design. The challenges facing design and analysis tools fall into three primary areas. The first area involves mechanics needs such as constitutive modeling, contact and penetration simulation, crack growth prediction, damage initiation and progression prediction, transient dynamics and deployment simulations, and solution algorithms. The second area involves computational needs such as fast, robust solvers, adaptivity for model and solution strategies, control processes for concurrent, distributed computing for uncertainty assessments, and immersive technology. Traditional finite element codes still require fast direct solvers which when coupled to current CPU power enables new insight as a result of high-fidelity modeling. The third area involves decision making by the analyst. This area involves the integration and interrogation of vast amounts of information - some global in character while local details are critical and often drive the design. The proposed presentation will describe and illustrate these areas using composite structures, energy-absorbing structures, and inflatable space structures. While certain engineering approximations within the finite element model may be adequate for global response prediction, they generally are inadequate in a design setting or when local response prediction is critical. Pitfalls to be avoided and trends for emerging analysis tools will be described.

Virtual Solar Energy Center: A Case Study of the Use of Advanced Visualization Techniques for the Comprehension of Complex Engineering Products and Processes

NASA Astrophysics Data System (ADS)

Ritter, Kenneth August, III

Industry has a continuing need to train its workforce on recent engineering developments, but many engineering products and processes are hard to explain because of limitations of size, visibility, time scale, cost, and safety. The product or process might be difficult to see because it is either very large or very small, because it is enclosed within an opaque container, or because it happens very fast or very slowly. Some engineering products and processes are also costly or unsafe to use for training purposes, and sometimes the domain expert is not physically available at the training location. All these limitations can potentially be addressed using advanced visualization techniques such as virtual reality. This dissertation describes the development of an immersive virtual reality application using the Six Sigma DMADV process to explain the main equipment and processes used in a concentrating solar power plant. The virtual solar energy center (VEC) application was initially developed and tested in a Cave Automatic Virtual Environment (CAVE) during 2013 and 2014. The software programs used for development were SolidWorks, 3ds Max Design, and Unity 3D. Current hardware and software technologies that could complement this research were analyzed. The NVIDA GRID Visual Computing Appliance (VCA) was chosen as the rendering solution for animating complex CAD models in this application. The MiddleVR software toolkit was selected as the toolkit for VR interactions and CAVE display. A non-immersive 3D version of the VEC application was tested and shown to be an effective training tool in late 2015. An immersive networked version of the VEC allows the user to receive live instruction from a trainer being projected via depth camera imagery from a remote location. Four comparative analysis studies were performed. These studies used the average normalized gain from pre-test scores to determine the effectiveness of the various training methods. With the DMADV approach, solutions were identified and verified during each iteration of the development, which saved valuable time and resulted in better results being achieved in each revision of the application, with the final version having 88% positive responses and same effectiveness as other methods assessed.

Strong Keratin-like Nanofibers Made of Globular Protein

NASA Astrophysics Data System (ADS)

Dror, Yael; Makarov, Vadim; Admon, Arie; Zussman, Eyal

2008-03-01

Protein fibers as elementary structural and functional elements in nature inspire the engineering of protein-based products for versatile bio-medical applications. We have recently used the electrospinning process to fabricate strong sub-micron fibers made solely of serum albumin (SA). This raises the challenges of turning a globular non-viscous protein solution into a polymer--like spinnable solution and producing keratin-like fibers enriched in inter S-S bridges. A stable spinning process was achieved by using SA solution in a rich trifluoroethanol-water mixture with β-mercaptoethanol. The breakage of the intra disulfide bridges, as identified by mass spectrometry, together with the denaturing alcohol, enabled a pronounced expansion of the protein. This in turn, affects the rheological properties of the solution. X-ray diffraction pattern of the fibers revealed equatorial orientation, indicating the alignment of structures along the fiber axis. The mechanical properties reached remarkable average values (Young's modulus of 1.6GPa, and max stress of 36MPa) as compared to other fibrous protein nanofibers. These significant results are attributed to both the alignment and inter disulfide bonds (cross linking) that were formed by spontaneous post-spinning oxidation.

Interactive training model of TRIZ for mechanical engineers in China

NASA Astrophysics Data System (ADS)

Tan, Runhua; Zhang, Huangao

2014-03-01

Innovation is a process of taking an original idea and converting it into a business value, in which the engineers face some inventive problems which can be solved hardly by experience. TRIZ, as a new theory for companies in China, provides both conceptual and procedural knowledge for finding and solving inventive problems. Because the government plays a leading role in the diffusion of TRIZ, too many companies from different industries are waiting to be trained, but the quantity of the trainers mastering TRIZ is incompatible with that requirement. In this context, to improve the training effect, an interactive training model of TRIZ for the mechanical engineers in China is developed and the implementation in the form of training classes is carried out. The training process is divided into 6 phases as follows: selecting engineers, training stage-1, finding problems, training stage-2, finding solutions and summing up. The government, TRIZ institutions and companies to join the programs interact during the process. The government initiates and monitors a project in form of a training class of TRIZ and selects companies to join the programs. Each selected companies choose a few engineers to join the class and supervises the training result. The TRIZ institutions design the training courses and carry out training curriculum. With the beginning of the class, an effective communication channel is established by means of interview, discussion face to face, E-mail, QQ and so on. After two years training practices, the results show that innovative abilities of the engineers to join and pass the final examinations increased distinctly, and most of companies joined the training class have taken congnizance of the power of TRIZ for product innovation. This research proposes an interactive training model of TRIZ for mechanical engineers in China to expedite the knowledge diffusion of TRIZ.

Evaluation of Graphite Fiber/Polyimide PMCs from Hot Melt vs Solution Prepreg

NASA Technical Reports Server (NTRS)

Shin, E. Eugene; Sutter, James K.; Eakin, Howard; Inghram, Linda; McCorkle, Linda; Scheiman, Dan; Papadopoulos, Demetrios; Thesken, John; Fink, Jeffrey E.

2002-01-01

Carbon fiber reinforced high temperature polymer matrix composites (PMC) have been extensively investigated as potential weight reduction replacements of various metallic components in next generation high performance propulsion rocket engines. The initial phase involves development of comprehensive composite material-process-structure-design-property-in-service performance correlations and database, especially for a high stiffness facesheet of various sandwich structures. Overview of the program plan, technical approaches and current multi-team efforts will be presented. During composite fabrication, it was found that the two large volume commercial prepregging methods (hot-melt vs. solution) resulted in considerably different composite cure behavior. Details of the process-induced physical and chemical modifications in the prepregs, their effects on composite processing, and systematic cure cycle optimization studies will be discussed. The combined effects of prepregging method and cure cycle modification on composite properties and isothermal aging performance were also evaluated.

Western Pyrenees geodetic deformation study using the Guipuzcoa GNSS network

NASA Astrophysics Data System (ADS)

Martín, Adriana; Sevilla, Miguel; Zurutuza, Joaquín

2018-07-01

The Basque Country in the north of Spain is located inside the Basque-Cantabrian basin of the western Pyrenees which remarkable seismic-tectonic implications justify the need of geodetic control in the area. In order to perform a crustal deformation study we have analysed all daily observations from the GNSS permanent network of Guipuzcoa and external IGS stations, from January 2007 to November 2011. We have carried out the data processing applying double differences methodology in the automatic processing module BPE (Bernese Processing Engine) from Bernese GNSS software version 5.0. Solution was aligned to geodetic reference framework ITRF2008, by using the IGS08 solution and updated satellite and terrestrial antennas calibration. This five years network study results: Coordinate time series, velocities and baseline lengths variations show internal stability among inner stations and from them with respect to outer IGS stations, concluding that no deformations have been observed.

Engineering topochemical polymerizations using block copolymer templates.

PubMed

Zhu, Liangliang; Tran, Helen; Beyer, Frederick L; Walck, Scott D; Li, Xin; Agren, Hans; Killops, Kato L; Campos, Luis M

2014-09-24

With the aim to achieve rapid and efficient topochemical polymerizations in the solid state, via solution-based processing of thin films, we report the integration of a diphenyldiacetylene monomer and a poly(styrene-b-acrylic acid) block copolymer template for the generation of supramolecular architectural photopolymerizable materials. This strategy takes advantage of non-covalent interactions to template a topochemical photopolymerization that yields a polydiphenyldiacetylene (PDPDA) derivative. In thin films, it was found that hierarchical self-assembly of the diacetylene monomers by microphase segregation of the block copolymer template enhances the topochemical photopolymerization, which is complete within a 20 s exposure to UV light. Moreover, UV-active cross-linkable groups were incorporated within the block copolymer template to create micropatterns of PDPDA by photolithography, in the same step as the polymerization reaction. The materials design and processing may find potential uses in the microfabrication of sensors and other important areas that benefit from solution-based processing of flexible conjugated materials.

Design and fabrication of a chitosan hydrogel with gradient structures via a step-by-step cross-linking process.

PubMed

Xu, Yongxiang; Yuan, Shenpo; Han, Jianmin; Lin, Hong; Zhang, Xuehui

2017-11-15

The development of scaffolds to mimic the gradient structure of natural tissue is an important consideration for effective tissue engineering. In the present study, a physical cross-linking chitosan hydrogel with gradient structures was fabricated via a step-by-step cross-linking process using sodium tripolyphosphate and sodium hydroxide as sequential cross-linkers. Chitosan hydrogels with different structures (single, double, and triple layers) were prepared by modifying the gelling process. The properties of the hydrogels were further adjusted by varying the gelling conditions, such as gelling time, pH, and composition of the crosslinking solution. Slight cytotoxicity was showed in MTT assay for hydrogels with uncross-linking chitosan solution and non-cytotoxicity was showed for other hydrogels. The results suggest that step-by-step cross-linking represents a practicable method to fabricate scaffolds with gradient structures. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of Graphite Fiber/Polyimide PMCs from Hot Melt versus Solution Prepreg

NASA Technical Reports Server (NTRS)

Shin, Eugene E.; Sutter, James K.; Eakin, Howard; Inghram, Linda; McCorkle, Linda; Scheiman, Dan; Papadopoulos, Demetrios; Thesken, John; Fink, Jeffrey E.; Gray, Hugh R. (Technical Monitor)

2002-01-01

Carbon fiber reinforced high temperature polymer matrix composites (PMC) have been extensively investigated as potential weight reduction replacements of various metallic components in next generation high performance propulsion rocket engines. The initial phase involves development of comprehensive composite material-process-structure-design-property in-service performance correlations and database, especially for a high stiffness facesheet of various sandwich structures. Overview of the program plan, technical approaches and current multi-team efforts will be presented. During composite fabrication, it was found that the two large volume commercial prepregging methods (hot-melt vs. solution) resulted in considerably different composite cure behavior. Details of the process-induced physical and chemical modifications in the prepregs, their effects on composite processing, and systematic cure cycle optimization studies will be discussed. The combined effects of prepregging method and cure cycle modification on composite properties and isothermal aging performance were also evaluated.

A new sol-gel processing routine without chelating agents for preparing highly transparent solutions and nanothin films: engineering the role of chemistry to design the process

NASA Astrophysics Data System (ADS)

Ashiri, Rouholah

2015-01-01

The great sensitivity of titanium alkoxides to hydrolysis makes their sol-gel transformation very fast and thus difficult to control. A method was proposed to alleviate this drawback. Preparation of highly transparent solutions and nanothin films is another objective of the present research. Employing nanoemulsion method and optimizing the processing conditions, a clear solution of well-dispersed nanosized particles was obtained. With the proposed process BaTiO3 precursor sols and nanothin films with enhanced optical transparency towards the visible were prepared. The optimal formulation of the sol consists of acetic acid, barium acetate, 2-propanol, TTIP and deionized water with 6:1:1:1:150 M ratios, respectively. It was found that the reduction of the temperature in the initial stage of mixing of precursors controls the size of the forming species and accordingly improves the stability and transparency of the sol. The results also showed that the applied modifications and optimizations significantly downsize the particles within the sol to the nanometric scale and accordingly result in a significant improvement in the optical response of the products.

Cost effective simulation-based multiobjective optimization in the performance of an internal combustion engine

NASA Astrophysics Data System (ADS)

Aittokoski, Timo; Miettinen, Kaisa

2008-07-01

Solving real-life engineering problems can be difficult because they often have multiple conflicting objectives, the objective functions involved are highly nonlinear and they contain multiple local minima. Furthermore, function values are often produced via a time-consuming simulation process. These facts suggest the need for an automated optimization tool that is efficient (in terms of number of objective function evaluations) and capable of solving global and multiobjective optimization problems. In this article, the requirements on a general simulation-based optimization system are discussed and such a system is applied to optimize the performance of a two-stroke combustion engine. In the example of a simulation-based optimization problem, the dimensions and shape of the exhaust pipe of a two-stroke engine are altered, and values of three conflicting objective functions are optimized. These values are derived from power output characteristics of the engine. The optimization approach involves interactive multiobjective optimization and provides a convenient tool to balance between conflicting objectives and to find good solutions.

Shuttle avionics software trials, tribulations and success

NASA Technical Reports Server (NTRS)

Henderson, O. L.

1985-01-01

The early problems and the solutions developed to provide the required quality software needed to support the space shuttle engine development program are described. The decision to use a programmable digital control system on the space shuttle engine was primarily based upon the need for a flexible control system capable of supporting the total engine mission on a large complex pump fed engine. The mission definition included all control phases from ground checkout through post shutdown propellant dumping. The flexibility of the controller through reprogrammable software allowed the system to respond to the technical challenges and innovation required to develop both the engine and controller hardware. This same flexibility, however, placed a severe strain on the capability of the software development and verification organization. The overall development program required that the software facility accommodate significant growth in both the software requirements and the number of software packages delivered. This challenge was met by reorganization and evolution in the process of developing and verifying software.

Automatic mathematical modeling for real time simulation system

NASA Technical Reports Server (NTRS)

Wang, Caroline; Purinton, Steve

1988-01-01

A methodology for automatic mathematical modeling and generating simulation models is described. The models will be verified by running in a test environment using standard profiles with the results compared against known results. The major objective is to create a user friendly environment for engineers to design, maintain, and verify their model and also automatically convert the mathematical model into conventional code for conventional computation. A demonstration program was designed for modeling the Space Shuttle Main Engine Simulation. It is written in LISP and MACSYMA and runs on a Symbolic 3670 Lisp Machine. The program provides a very friendly and well organized environment for engineers to build a knowledge base for base equations and general information. It contains an initial set of component process elements for the Space Shuttle Main Engine Simulation and a questionnaire that allows the engineer to answer a set of questions to specify a particular model. The system is then able to automatically generate the model and FORTRAN code. The future goal which is under construction is to download the FORTRAN code to VAX/VMS system for conventional computation. The SSME mathematical model will be verified in a test environment and the solution compared with the real data profile. The use of artificial intelligence techniques has shown that the process of the simulation modeling can be simplified.

Engine With Regression and Neural Network Approximators Designed

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Hopkins, Dale A.

2001-01-01

At the NASA Glenn Research Center, the NASA engine performance program (NEPP, ref. 1) and the design optimization testbed COMETBOARDS (ref. 2) with regression and neural network analysis-approximators have been coupled to obtain a preliminary engine design methodology. The solution to a high-bypass-ratio subsonic waverotor-topped turbofan engine, which is shown in the preceding figure, was obtained by the simulation depicted in the following figure. This engine is made of 16 components mounted on two shafts with 21 flow stations. The engine is designed for a flight envelope with 47 operating points. The design optimization utilized both neural network and regression approximations, along with the cascade strategy (ref. 3). The cascade used three algorithms in sequence: the method of feasible directions, the sequence of unconstrained minimizations technique, and sequential quadratic programming. The normalized optimum thrusts obtained by the three methods are shown in the following figure: the cascade algorithm with regression approximation is represented by a triangle, a circle is shown for the neural network solution, and a solid line indicates original NEPP results. The solutions obtained from both approximate methods lie within one standard deviation of the benchmark solution for each operating point. The simulation improved the maximum thrust by 5 percent. The performance of the linear regression and neural network methods as alternate engine analyzers was found to be satisfactory for the analysis and operation optimization of air-breathing propulsion engines (ref. 4).

Engineering polyelectrolyte multilayer structure at the nanometer length scale by tuning polymer solution conformation.

NASA Astrophysics Data System (ADS)

Boddohi, Soheil; Killingsworth, Christopher; Kipper, Matt

2008-03-01

Chitosan (a weak polycation) and heparin (a strong polyanion) are used to make polyelectrolyte multilayers (PEM). PEM thickness and composition are determined as a function of solution pH (4.6 to 5.8) and ionic strength (0.1 to 0.5 M). Over this range, increasing pH increases the PEM thickness; however, the sensitivity to changes in pH is a strong function of ionic strength. The PEM thickness data are correlated to the polymer conformation in solution. Polyelectrolyte conformation in solution is characterized by gel permeation chromatography (GPC). The highest sensitivity of PEM structure to pH is obtained at intermediate ionic strength. Different interactions govern the conformation and adsorption phenomena at low and high ionic strength, leading to reduced sensitivity to solution pH at extreme ionic strengths. The correspondence between PEM thickness and polymer solution conformation offers opportunities to tune polymer thin film structure at the nanometer length scale by controlling simple, reproducible processing conditions.

77 FR 14571 - Waste Regulation

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-12

.... FOR FURTHER INFORMATION CONTACT: Polly A. Penhale, Environmental Officer, at the above address or (703... identified as: Lockheed Martin Corporation, Information Systems & Global Solutions (I&GS) Engineering... holder's address to: Lockheed Corporation, Information Systems & Global Solutions (I&GS) Engineering...

USM3D Simulations of Saturn V Plume Induced Flow Separation

NASA Technical Reports Server (NTRS)

Deere, Karen; Elmlilgui, Alaa; Abdol-Hamid, K. S.

2011-01-01

The NASA Constellation Program included the Ares V heavy lift cargo vehicle. During the design stage, engineers questioned if the Plume Induced Flow Separation (PIFS) that occurred along Saturn V rocket during moon missions at some flight conditions, would also plague the newly proposed rocket. Computational fluid dynamics (CFD) was offered as a tool for initiating the investigation of PIFS along the Ares V rocket. However, CFD best practice guidelines were not available for such an investigation. In an effort to establish a CFD process and define guidelines for Ares V powered simulations, the Saturn V vehicle was used because PIFS flight data existed. The ideal gas, computational flow solver USM3D was evaluated for its viability in computing PIFS along the Saturn V vehicle with F-1 engines firing. Solutions were computed at supersonic freestream conditions, zero degree angle of attack, zero degree sideslip, and at flight Reynolds numbers. The effects of solution sensitivity to grid refinement, turbulence models, and the engine boundary conditions on the predicted PIFS distance along the Saturn V were discussed and compared to flight data from the Apollo 11 mission AS-506.

Low-Activity Waste Pretreatment System Additional Engineering-Scale Integrated Test Report

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

Landon, Matt R.; Wilson, Robert A.

Washington River Protections Solutions, LLC’s (WRPS) Low Activity Waste Pretreatment System (LAWPS) Project provides for the early production of immobilized low-activity waste (ILAW) by feeding LAW directly from Tank Farms to the Waste Treatment and Immobilization Plant (WTP) LAW Facility, bypassing the WTP Pretreatment Facility. Prior to the transfer of feed to the WTP LAW Vitrification Facility, tank supernatant waste will be pretreated in the LAWPS to meet the WTP LAW waste acceptance criteria (WAC). Full-scale and engineering-scale testing of critical technology elements, as part of the technology maturation process, are components of the overall LAWPS Project. WRPS awarded themore » engineering-scale integrated testing scope to AECOM via WRPS Subcontract 58349. This report is deliverable MSR-008 of the subcontract.« less

Tailoring entanglement through domain engineering in a lithium niobate waveguide

PubMed Central

Ming, Yang; Tan, Ai-Hong; Wu, Zi-Jian; Chen, Zhao-Xian; Xu, Fei; Lu, Yan-Qing

2014-01-01

We propose to integrate the electro-optic (EO) tuning function into on-chip domain engineered lithium niobate (LN) waveguide. Due to the versatility of LN, both the spontaneously parametric down conversion (SPDC) and EO interaction could be realized simultaneously. Photon pairs are generated through SPDC, and the formation of entangled state is modulated by EO processes. An EO tunable polarization-entangled photon state is proposed. Orthogonally-polarized and parallel-polarized entanglements of photon pairs are instantly switchable by tuning the applied field. The characteristics of the source are theoretically investigated showing adjustable bandwidths and high entanglement degrees. Moreover, other kinds of reconfigurable entanglement are also achievable based on suitable domain-design. We believe tailoring entanglement based on domain engineering is a very promising solution for next generation function-integrated quantum circuits. PMID:24770555

Strategies for enhancing microbial tolerance to inhibitors for biofuel production: A review.

PubMed

Wang, Shizeng; Sun, Xinxiao; Yuan, Qipeng

2018-06-01

Using lignocellulosic biomass for the production of renewable biofuel provides a sustainable and promising solution to the crisis of energy and environment. However, the processes of biomass pretreatment and biofuel fermentation bring a variety of inhibitors to microbial strains. These inhibitors repress microbial growth, decrease biofuel yields and increase fermentation costs. The production of biofuels from renewable lignocellulosic biomass relies on the development of tolerant and robust microbial strains. In recent years, the advancement of tolerance engineering and evolutionary engineering provides powerful platform for obtaining host strains with desired tolerance for further metabolic engineering of biofuel pathways. In this review, we summarized the inhibitors derived from biomass pretreatment and biofuel fermentation, the mechanisms of inhibitor toxicity, and the strategies for enhancing microbial tolerance. Copyright © 2018 Elsevier Ltd. All rights reserved.

A simple performance calculation method for LH2/LOX engines with different power cycles

NASA Technical Reports Server (NTRS)

Schmucker, R. H.

1973-01-01

A simple method for the calculation of the specific impulse of an engine with a gas generator cycle is presented. The solution is obtained by a power balance between turbine and pump. Approximate equations for the performance of the combustion products of LH2/LOX are derived. Performance results are compared with solutions of different engine types.

Liquid Nitrogen Removal of Critical Aerospace Materials

NASA Technical Reports Server (NTRS)

Noah, Donald E.; Merrick, Jason; Hayes, Paul W.

2005-01-01

Identification of innovative solutions to unique materials problems is an every-day quest for members of the aerospace community. Finding a technique that will minimize costs, maximize throughput, and generate quality results is always the target. United Space Alliance Materials Engineers recently conducted such a search in their drive to return the Space Shuttle fleet to operational status. The removal of high performance thermal coatings from solid rocket motors represents a formidable task during post flight disassembly on reusable expended hardware. The removal of these coatings from unfired motors increases the complexity and safety requirements while reducing the available facilities and approved processes. A temporary solution to this problem was identified, tested and approved during the Solid Rocket Booster (SRB) return to flight activities. Utilization of ultra high-pressure liquid nitrogen (LN2) to strip the protective coating from assembled space shuttle hardware marked the first such use of the technology in the aerospace industry. This process provides a configurable stream of liquid nitrogen (LN2) at pressures of up to 55,000 psig. The performance of a one-time certification for the removal of thermal ablatives from SRB hardware involved extensive testing to ensure adequate material removal without causing undesirable damage to the residual materials or aluminum substrates. Testing to establish appropriate process parameters such as flow, temperature and pressures of the liquid nitrogen stream provided an initial benchmark for process testing. Equipped with these initial parameters engineers were then able to establish more detailed test criteria that set the process limits. Quantifying the potential for aluminum hardware damage represented the greatest hurdle for satisfying engineers as to the safety of this process. Extensive testing for aluminum erosion, surface profiling, and substrate weight loss was performed. This successful project clearly demonstrated that the liquid nitrogen jet possesses unique strengths that align remarkably well with the unusual challenges that space hardware and missile manufacturers face on a regular basis. Performance of this task within the confines of a critical manufacturing facility marks a milestone in advanced processing.

Development of manufacturing systems for nanocrystalline and ultra-fine grain materials employing indexing equal channel angular pressing

NASA Astrophysics Data System (ADS)

Hester, Michael Wayne

Nanotechnology offers significant opportunities in providing solutions to existing engineering problems as well as breakthroughs in new fields of science and technology. In order to fully realize benefits from such initiatives, nanomanufacturing methods must be developed to integrate enabling constructs into commercial mainstream. Even though significant advances have been made, widespread industrialization in many areas remains limited. Manufacturing methods, therefore, must continually be developed to bridge gaps between nanoscience discovery and commercialization. A promising technology for integration of top-down nanomanufacturing yet to receive full industrialization is equal channel angular pressing, a process transforming metallic materials into nanostructured or ultra-fine grained materials with significantly improved performance characteristics. To bridge the gap between process potential and actual manufacturing output, a prototype top-down nanomanufacturing system identified as indexing equal channel angular pressing (IX-ECAP) was developed. The unit was designed to capitalize on opportunities of transforming spent or scrap engineering elements into key engineering commodities. A manufacturing system was constructed to impose severe plastic deformation via simple shear in an equal channel angular pressing die on 1100 and 4043 aluminum welding rods. 1/4 fraction factorial split-plot experiments assessed significance of five predictors on the response, microhardness, for the 4043 alloy. Predictor variables included temperature, number of passes, pressing speed, back pressure, and vibration. Main effects were studied employing a resolution III design. Multiple linear regression was used for model development. Initial studies were performed using continuous processing followed by contingency designs involving discrete variable length work pieces. IX-ECAP offered a viable solution in severe plastic deformation processing. Discrete variable length work piece pressing proved very successful. With three passes through the system, 4043 processed material experienced an 88.88% increase in microhardness, 203.4% increase in converted yield strength, and a 98.5% reduction in theoretical final grain size to 103 nanometers using the Hall-Petch relation. The process factor, number of passes, was statistically significant at the 95% confidence level; whereas, temperature was significant at the 90% confidence level. Limitations of system components precluded completion of studies involving continuous pressing. Proposed system redesigns, however, will ensure mainstream commercialization of continuous length work piece processing.

Programmed Evolution for Optimization of Orthogonal Metabolic Output in Bacteria

PubMed Central

Eckdahl, Todd T.; Campbell, A. Malcolm; Heyer, Laurie J.; Poet, Jeffrey L.; Blauch, David N.; Snyder, Nicole L.; Atchley, Dustin T.; Baker, Erich J.; Brown, Micah; Brunner, Elizabeth C.; Callen, Sean A.; Campbell, Jesse S.; Carr, Caleb J.; Carr, David R.; Chadinha, Spencer A.; Chester, Grace I.; Chester, Josh; Clarkson, Ben R.; Cochran, Kelly E.; Doherty, Shannon E.; Doyle, Catherine; Dwyer, Sarah; Edlin, Linnea M.; Evans, Rebecca A.; Fluharty, Taylor; Frederick, Janna; Galeota-Sprung, Jonah; Gammon, Betsy L.; Grieshaber, Brandon; Gronniger, Jessica; Gutteridge, Katelyn; Henningsen, Joel; Isom, Bradley; Itell, Hannah L.; Keffeler, Erica C.; Lantz, Andrew J.; Lim, Jonathan N.; McGuire, Erin P.; Moore, Alexander K.; Morton, Jerrad; Nakano, Meredith; Pearson, Sara A.; Perkins, Virginia; Parrish, Phoebe; Pierson, Claire E.; Polpityaarachchige, Sachith; Quaney, Michael J.; Slattery, Abagael; Smith, Kathryn E.; Spell, Jackson; Spencer, Morgan; Taye, Telavive; Trueblood, Kamay; Vrana, Caroline J.; Whitesides, E. Tucker

2015-01-01

Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields – evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed with DNA code to enable it to compute solutions to a chosen optimization problem. As analog computers, bacteria process known and unknown inputs and direct the output of their biochemical hardware. Second, the system employs the evolution of bacteria toward an optimal metabolic solution by imposing fitness defined by metabolic output. The current study is a proof-of-concept for Programmed Evolution applied to the optimization of a metabolic pathway for the conversion of caffeine to theophylline in E. coli. Introduced genotype variations included strength of the promoter and ribosome binding site, plasmid copy number, and chaperone proteins. We constructed 24 strains using all combinations of the genetic variables. We used a theophylline riboswitch and a tetracycline resistance gene to link theophylline production to fitness. After subjecting the mixed population to selection, we measured a change in the distribution of genotypes in the population and an increased conversion of caffeine to theophylline among the most fit strains, demonstrating Programmed Evolution. Programmed Evolution inverts the standard paradigm in metabolic engineering by harnessing evolution instead of fighting it. Our modular system enables researchers to program bacteria and use evolution to determine the combination of genetic control elements that optimizes catabolic or anabolic output and to maintain it in a population of cells. Programmed Evolution could be used for applications in energy, pharmaceuticals, chemical commodities, biomining, and bioremediation. PMID:25714374

Programmed evolution for optimization of orthogonal metabolic output in bacteria.

PubMed

Eckdahl, Todd T; Campbell, A Malcolm; Heyer, Laurie J; Poet, Jeffrey L; Blauch, David N; Snyder, Nicole L; Atchley, Dustin T; Baker, Erich J; Brown, Micah; Brunner, Elizabeth C; Callen, Sean A; Campbell, Jesse S; Carr, Caleb J; Carr, David R; Chadinha, Spencer A; Chester, Grace I; Chester, Josh; Clarkson, Ben R; Cochran, Kelly E; Doherty, Shannon E; Doyle, Catherine; Dwyer, Sarah; Edlin, Linnea M; Evans, Rebecca A; Fluharty, Taylor; Frederick, Janna; Galeota-Sprung, Jonah; Gammon, Betsy L; Grieshaber, Brandon; Gronniger, Jessica; Gutteridge, Katelyn; Henningsen, Joel; Isom, Bradley; Itell, Hannah L; Keffeler, Erica C; Lantz, Andrew J; Lim, Jonathan N; McGuire, Erin P; Moore, Alexander K; Morton, Jerrad; Nakano, Meredith; Pearson, Sara A; Perkins, Virginia; Parrish, Phoebe; Pierson, Claire E; Polpityaarachchige, Sachith; Quaney, Michael J; Slattery, Abagael; Smith, Kathryn E; Spell, Jackson; Spencer, Morgan; Taye, Telavive; Trueblood, Kamay; Vrana, Caroline J; Whitesides, E Tucker

2015-01-01

Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields - evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed with DNA code to enable it to compute solutions to a chosen optimization problem. As analog computers, bacteria process known and unknown inputs and direct the output of their biochemical hardware. Second, the system employs the evolution of bacteria toward an optimal metabolic solution by imposing fitness defined by metabolic output. The current study is a proof-of-concept for Programmed Evolution applied to the optimization of a metabolic pathway for the conversion of caffeine to theophylline in E. coli. Introduced genotype variations included strength of the promoter and ribosome binding site, plasmid copy number, and chaperone proteins. We constructed 24 strains using all combinations of the genetic variables. We used a theophylline riboswitch and a tetracycline resistance gene to link theophylline production to fitness. After subjecting the mixed population to selection, we measured a change in the distribution of genotypes in the population and an increased conversion of caffeine to theophylline among the most fit strains, demonstrating Programmed Evolution. Programmed Evolution inverts the standard paradigm in metabolic engineering by harnessing evolution instead of fighting it. Our modular system enables researchers to program bacteria and use evolution to determine the combination of genetic control elements that optimizes catabolic or anabolic output and to maintain it in a population of cells. Programmed Evolution could be used for applications in energy, pharmaceuticals, chemical commodities, biomining, and bioremediation.

LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

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

King, W

2007-11-30

This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials havemore » been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA. Application of RF for cesium removal in the Hanford WTP does not involve in-riser columns but does utilize the resin in large scale column configurations in a waste treatment facility. The basic conceptual design for SCIX involves the dissolution of saltcake in SRS Tanks 1-3 to give approximately 6 M sodium solutions and the treatment of these solutions for cesium removal using one or two columns supported within a high level waste tank. Prior to ion exchange treatment, the solutions will be filtered for removal of entrained solids. In addition to Tanks 1-3, solutions in two other tanks (37 and 41) will require treatment for cesium removal in the SCIX unit. The previous SCIX design (McCabe, 2005) utilized CST for cesium removal with downflow supernate processing and included a CST grinder following cesium loading. Grinding of CST was necessary to make the cesium-loaded material suitable for vitrification in the SRS Defense Waste Processing Facility (DWPF). Because RF resin is elutable (and reusable) and processing requires conversion between sodium and hydrogen forms using caustic and acidic solutions more liquid processing steps are involved. The WTP baseline process involves a series of caustic and acidic solutions (downflow processing) with water washes between pH transitions across neutral. In addition, due to resin swelling during conversion from hydrogen to sodium form an upflow caustic regeneration step is required. Presumably, one of these basic processes (or some variation) will be utilized for MSP for the appropriate ion exchange technology selected. CST processing involves two primary waste products: loaded CST and decontaminated salt solution (DSS). RF processing involves three primary waste products: spent RF resin, DSS, and acidic cesium eluate, although the resin is reusable and typically does not require replacement until completion of multiple treatment cycles. CST processing requires grinding of the ion exchange media, handling of solids with high cesium loading, and handling of liquid wash and conditioning solutions. RF processing requires handling and evaporation of cesium eluates, disposal of spent organic resin, and handling of the various liquid wash and regenerate solutions used. In both cases, the DSS will be immobilized in a low activity waste form. It appears that both technologies are mature, well studied, and generally suitable for this application. Technology selection will likely be based on downstream impacts or preferences between the various processing options for the two materials rather than on some unacceptable performance property identified for one material. As a result, the following detailed technical review and summary of the two technologies should be useful to assist in technology selection for SCIX.« less

Hybrid neuro-heuristic methodology for simulation and control of dynamic systems over time interval.

PubMed

Woźniak, Marcin; Połap, Dawid

2017-09-01

Simulation and positioning are very important aspects of computer aided engineering. To process these two, we can apply traditional methods or intelligent techniques. The difference between them is in the way they process information. In the first case, to simulate an object in a particular state of action, we need to perform an entire process to read values of parameters. It is not very convenient for objects for which simulation takes a long time, i.e. when mathematical calculations are complicated. In the second case, an intelligent solution can efficiently help on devoted way of simulation, which enables us to simulate the object only in a situation that is necessary for a development process. We would like to present research results on developed intelligent simulation and control model of electric drive engine vehicle. For a dedicated simulation method based on intelligent computation, where evolutionary strategy is simulating the states of the dynamic model, an intelligent system based on devoted neural network is introduced to control co-working modules while motion is in time interval. Presented experimental results show implemented solution in situation when a vehicle transports things over area with many obstacles, what provokes sudden changes in stability that may lead to destruction of load. Therefore, applied neural network controller prevents the load from destruction by positioning characteristics like pressure, acceleration, and stiffness voltage to absorb the adverse changes of the ground. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthetic Materials for Osteochondral Tissue Engineering.

PubMed

Iulian, Antoniac; Dan, Laptoiu; Camelia, Tecu; Claudia, Milea; Sebastian, Gradinaru

2018-01-01

The objective of an articular cartilage repair treatment is to repair the affected surface of an articular joint's hyaline cartilage. Currently, both biological and tissue engineering research is concerned with discovering the clues needed to stimulate cells to regenerate tissues and organs totally or partially. The latest findings on nanotechnology advances along with the processability of synthetic biomaterials have succeeded in creating a new range of materials to develop into the desired biological responses to the cellular level. 3D printing has a great ability to establish functional tissues or organs to cure or replace abnormal and necrotic tissue, providing a promising solution for serious tissue/organ failure. The 4D print process has the potential to continually revolutionize the current tissue and organ manufacturing platforms. A new active research area is the development of intelligent materials with high biocompatibility to suit 4D printing technology. As various researchers and tissue engineers have demonstrated, the role of growth factors in tissue engineering for repairing osteochondral and cartilage defects is a very important one. Following animal testing, cell-assisted and growth-factor scaffolds produced much better results, while growth-free scaffolds showed a much lower rate of healing.

Towards Requirements in Systems Engineering for Aerospace IVHM Design

NASA Technical Reports Server (NTRS)

Saxena, Abhinav; Roychoudhury, Indranil; Lin, Wei; Goebel, Kai

2013-01-01

Health management (HM) technologies have been employed for safety critical system for decades, but a coherent systematic process to integrate HM into the system design is not yet clear. Consequently, in most cases, health management resorts to be an after-thought or 'band-aid' solution. Moreover, limited guidance exists for carrying out systems engineering (SE) on the subject of writing requirements for designs with integrated vehicle health management (IVHM). It is well accepted that requirements are key to developing a successful IVHM system right from the concept stage to development, verification, utilization, and support. However, writing requirements for systems with IVHM capability have unique challenges that require the designers to look beyond their own domains and consider the constraints and specifications of other interlinked systems. In this paper we look at various stages in the SE process and identify activities specific to IVHM design and development. More importantly, several relevant questions are posed that system engineers must address at various design and development stages. Addressing these questions should provide some guidance to systems engineers towards writing IVHM related requirements to ensure that appropriate IVHM functions are built into the system design.

Evolution of the teachings of chemistry in the new degrees of School of Agricultural Engineering and its importance in the acquisition of competencies

NASA Astrophysics Data System (ADS)

Arce, Augusto; Tarquis, Ana M.; Castellanos, Maria Teresa; Requejo, Maria Isabel; Cartagena, Maria Carmen

2014-05-01

The academic year 2012-13 is the third year of implementation of the Bologna process in ETSI Agricultural for the subjects Chemistry I and Chemistry II in the new four Degrees: Graduate in Engineering and Agricultural Science, Food Engineering Graduate, Graduate in Engineering Environmental and Biotechnology graduate. We have implemented new interactive methodologies in the teaching-learning process based on the use of the virtual platform of the UPM, and teaching support materials and new laboratory practice developing has. It has also launched new continuous assessment systems that promote active student participation. A comparative study of academic achievements by students of the new grades in the subjects of chemistry during the last three academic years was performed to correlating the results obtained, the success rate and the drop out, and compare with the level of prior knowledge to those entering students. Possible solutions to try and fix these results in future courses are proposed Finally, the general competencies that contribute this course, how they are acquired and how they should be evaluated correctly are indicated. Acknowledgments: Innovation educative projects Nº IE02054-11/12 UPM. 2012

Cell culture media impact on drug product solution stability.

PubMed

Purdie, Jennifer L; Kowle, Ronald L; Langland, Amie L; Patel, Chetan N; Ouyang, Anli; Olson, Donald J

2016-07-08

To enable subcutaneous administration of monoclonal antibodies, drug product solutions are often needed at high concentrations. A significant risk associated with high drug product concentrations is an increase in aggregate level over the shelf-life dating period. While much work has been done to understand the impact of drug product formulation on aggregation, there is limited understanding of the link between cell culture process conditions and soluble aggregate growth in drug product. During cell culture process development, soluble aggregates are often measured at harvest using cell-free material purified by Protein A chromatography. In the work reported here, cell culture media components were evaluated with respect to their impact on aggregate levels in high concentration solution drug product during accelerated stability studies. Two components, cysteine and ferric ammonium citrate, were found to impact aggregate growth rates in our current media (version 1) leading to the development of new chemically defined media and concentrated feed formulations. The new version of media and associated concentrated feeds (version 2) were evaluated across four cell lines producing recombinant IgG4 monoclonal antibodies and a bispecific antibody. In all four cell lines, the version 2 media reduced aggregate growth over the course of a 12 week accelerated stability study compared with the version 1 media, although the degree to which aggregate growth decreased was cell line dependent. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:998-1008, 2016. © 2016 American Institute of Chemical Engineers.

Multicriteria Analysis of Assembling Buildings from Steel Frame Structures

NASA Astrophysics Data System (ADS)

Miniotaite, Ruta

2017-10-01

Steel frame structures are often used in the construction of public and industrial buildings. They are used for: all types of slope roofs; walls of newly-built public and industrial buildings; load bearing structures; roofs of renovated buildings. The process of assembling buildings from steel frame structures should be analysed as an integrated process influenced by such factors as construction materials and machinery used, the qualification level of construction workers, complexity of work, available finance. It is necessary to find a rational technological design solution for assembling buildings from steel frame structures by conducting a multiple criteria analysis. The analysis provides a possibility to evaluate the engineering considerations and find unequivocal solutions. The rational alternative of a complex process of assembling buildings from steel frame structures was found through multiple criteria analysis and multiple criteria evaluation. In multiple criteria evaluation of technological solutions for assembling buildings from steel frame structures by pairwise comparison method the criteria by significance are distributed as follows: durability is the most important criterion in the evaluation of alternatives; the price (EUR/unit of measurement) of a part of assembly process; construction workers’ qualification level (category); mechanization level of a part of assembling process (%), and complexity of assembling work (in points) are less important criteria.

Multidisciplinary Analysis of a Hypersonic Engine

NASA Technical Reports Server (NTRS)

Stewart, M. E. M.; Suresh, A.; Liou, M. S.; Owen, A. K.; Messitt, D. G.

2002-01-01

This paper describes implementation of a technique used to obtain a high fidelity fluid-thermal-structural solution of a combined cycle engine at its scram design point. Single-discipline simulations are insufficient here since interactions from other disciplines are significant. Using off-the-shelf, validated solvers for the fluid, chemistry, thermal, and structural solutions, this approach couples together their results to obtain consistent solutions.

Silicon Carbide Technologies for Lightweighted Aerospace Mirrors

NASA Astrophysics Data System (ADS)

Matson, L.; Chen, M.; Deblonk, B.; Palusinski, I.

The use of monolithic glass and beryllium to produce lightweighted aerospace mirror systems has reached its limits due to the long lead times, high processing costs, environmental effects and launch load/weight requirements. New material solutions and manufacturing processes are required to meet DoD's directed energy weapons, reconnaissance/surveillance, and secured communications needs. Over the past several years the Air Force, MDA, and NASA has focused their efforts on the fabrication, lightweighting, and scale-up of numerous silicon carbide (SiC) based materials. It is anticipated that SiC can be utilized for most applications from cryogenic to high temperatures. This talk will focus on describing the SOA for these (near term) SiC technology solutions for making mirror structural substrates, figuring and finishing technologies being investigated to reduce cost time and cost, and non-destructive evaluation methods being investigated to help eliminate risk. Mirror structural substrates made out of advanced engineered materials (far term solutions) such as composites, foams, and microsphere arrays for ultra lightweighting will also be briefly discussed.

Solution-processable ambipolar diketopyrrolopyrrole-selenophene polymer with unprecedentedly high hole and electron mobilities.

PubMed

Lee, Junghoon; Han, A-Reum; Kim, Jonggi; Kim, Yiho; Oh, Joon Hak; Yang, Changduk

2012-12-26

There is a fast-growing demand for polymer-based ambipolar thin-film transistors (TFTs), in which both n-type and p-type transistor operations are realized in a single layer, while maintaining simplicity in processing. Research progress toward this end is essentially fueled by molecular engineering of the conjugated backbones of the polymers and the development of process architectures for device fabrication, which has recently led to hole and electron mobilities of more than 1.0 cm(2) V(-1) s(-1). However, ambipolar polymers with even higher performance are still required. By taking into account both the conjugated backbone and side chains of the polymer component, we have developed a dithienyl-diketopyrrolopyrrole (TDPP) and selenophene containing polymer with hybrid siloxane-solubilizing groups (PTDPPSe-Si). A synergistic combination of rational polymer backbone design, side-chain dynamics, and solution processing affords an enormous boost in ambipolar TFT performance, resulting in unprecedentedly high hole and electron mobilities of 3.97 and 2.20 cm(2) V(-1) s(-1), respectively.

Comparison of Cross Flow Filtration Performance for Manganese Oxide/Sludge Mixtures and Monosodium Titanate/Sludge Mixtures

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

Poirier, M.R.

2002-06-07

Personnel performed engineering-scale tests at the Filtration Research Engineering Demonstration (FRED) to determine crossflow filter performance with a 5.6 M sodium solution containing varying concentrations of sludge and sodium permanganate. The work represents another in a series of collaborative efforts between the University of South Carolina and the Savannah River Technology Center in support of the process development efforts for the Savannah River Site. The current tests investigated filter performance with slurry containing simulated Tank 40H Sludge and sodium permanganate at concentrations between 0.070 weight percent and 3.04 weight percent insoluble solids.

Improvement of ecological characteristics of the hydrogen diesel engine

NASA Astrophysics Data System (ADS)

Natriashvili, T.; Kavtaradze, R.; Glonti, M.

2018-02-01

In the article are considered the questions of influence of a swirl intensity of the shot and injector design on the ecological indices of the hydrogen diesel, little-investigated till now. The necessity of solution of these problems arises at conversion of the serial diesel engine into the hydrogen diesel. The mathematical model consists of the three-dimensional non-stationary equations of transfer and also models of turbulence and combustion. The numerical experiments have been carried out with the use of program code FIRE. The optimal values of parameters of the working process, ensuring improvement of the effective and ecological indices of the hydrogen diesel are determined.

Productivity improvement using industrial engineering tools

NASA Astrophysics Data System (ADS)

Salaam, H. A.; How, S. B.; Faisae, M. F.

2012-09-01

Minimizing the number of defects is important to any company since it influence their outputs and profits. The aim of this paper is to study the implementation of industrial engineering tools in a manufacturing recycle paper box company. This study starts with reading the standard operation procedures and analyzing the process flow to get the whole idea on how to manufacture paper box. At the same time, observations at the production line were made to identify problem occurs in the production line. By using check sheet, the defect data from each station were collected and have been analyzed using Pareto Chart. From the chart, it is found that glue workstation shows the highest number of defects. Based on observation at the glue workstation, the existing method used to glue the box was inappropriate because the operator used a lot of glue. Then, by using cause and effect diagram, the root cause of the problem was identified and solutions to overcome the problem were proposed. There are three suggestions proposed to overcome this problem. Cost reduction for each solution was calculated and the best solution is using three hair drier to dry the sticky glue which produce only 6.4 defects in an hour with cost of RM 0.0224.

A Management Model for International Participation in Space Exploration Missions

NASA Technical Reports Server (NTRS)

George, Patrick J.; Pease, Gary M.; Tyburski, Timothy E.

2005-01-01

This paper proposes an engineering management model for NASA's future space exploration missions based on past experiences working with the International Partners of the International Space Station. The authors have over 25 years of combined experience working with the European Space Agency, Japan Aerospace Exploration Agency, Canadian Space Agency, Italian Space Agency, Russian Space Agency, and their respective contractors in the design, manufacturing, verification, and integration of their elements electric power system into the United States on-orbit segment. The perspective presented is one from a specific sub-system integration role and is offered so that the lessons learned from solving issues of technical and cultural nature may be taken into account during the formulation of international partnerships. Descriptions of the types of unique problems encountered relative to interactions between international partnerships are reviewed. Solutions to the problems are offered, taking into consideration the technical implications. Through the process of investigating each solution, the important and significant issues associated with working with international engineers and managers are outlined. Potential solutions are then characterized by proposing a set of specific methodologies to jointly develop spacecraft configurations that benefits all international participants, maximizes mission success and vehicle interoperability while minimizing cost.

A Benchmarking Initiative for Reactive Transport Modeling Applied to Subsurface Environmental Applications

NASA Astrophysics Data System (ADS)

Steefel, C. I.

2015-12-01

Over the last 20 years, we have seen the evolution of multicomponent reactive transport modeling and the expanding range and increasing complexity of subsurface environmental applications it is being used to address. Reactive transport modeling is being asked to provide accurate assessments of engineering performance and risk for important issues with far-reaching consequences. As a result, the complexity and detail of subsurface processes, properties, and conditions that can be simulated have significantly expanded. Closed form solutions are necessary and useful, but limited to situations that are far simpler than typical applications that combine many physical and chemical processes, in many cases in coupled form. In the absence of closed form and yet realistic solutions for complex applications, numerical benchmark problems with an accepted set of results will be indispensable to qualifying codes for various environmental applications. The intent of this benchmarking exercise, now underway for more than five years, is to develop and publish a set of well-described benchmark problems that can be used to demonstrate simulator conformance with norms established by the subsurface science and engineering community. The objective is not to verify this or that specific code--the reactive transport codes play a supporting role in this regard—but rather to use the codes to verify that a common solution of the problem can be achieved. Thus, the objective of each of the manuscripts is to present an environmentally-relevant benchmark problem that tests the conceptual model capabilities, numerical implementation, process coupling, and accuracy. The benchmark problems developed to date include 1) microbially-mediated reactions, 2) isotopes, 3) multi-component diffusion, 4) uranium fate and transport, 5) metal mobility in mining affected systems, and 6) waste repositories and related aspects.

Marshall Space Flight Center Materials and Processes Laboratory

NASA Technical Reports Server (NTRS)

Tramel, Terri L.

2012-01-01

Marshall?s Materials and Processes Laboratory has been a core capability for NASA for over fifty years. MSFC has a proven heritage and recognized expertise in materials and manufacturing that are essential to enable and sustain space exploration. Marshall provides a "systems-wise" capability for applied research, flight hardware development, and sustaining engineering. Our history of leadership and achievements in materials, manufacturing, and flight experiments includes Apollo, Skylab, Mir, Spacelab, Shuttle (Space Shuttle Main Engine, External Tank, Reusable Solid Rocket Motor, and Solid Rocket Booster), Hubble, Chandra, and the International Space Station. MSFC?s National Center for Advanced Manufacturing, NCAM, facilitates major M&P advanced manufacturing partnership activities with academia, industry and other local, state and federal government agencies. The Materials and Processes Laborato ry has principal competencies in metals, composites, ceramics, additive manufacturing, materials and process modeling and simulation, space environmental effects, non-destructive evaluation, and fracture and failure analysis provide products ranging from materials research in space to fully integrated solutions for large complex systems challenges. Marshall?s materials research, development and manufacturing capabilities assure that NASA and National missions have access to cutting-edge, cost-effective engineering design and production options that are frugal in using design margins and are verified as safe and reliable. These are all critical factors in both future mission success and affordability.

Topology reconstruction for B-Rep modeling from 3D mesh in reverse engineering applications

NASA Astrophysics Data System (ADS)

Bénière, Roseline; Subsol, Gérard; Gesquière, Gilles; Le Breton, François; Puech, William

2012-03-01

Nowadays, most of the manufactured objects are designed using CAD (Computer-Aided Design) software. Nevertheless, for visualization, data exchange or manufacturing applications, the geometric model has to be discretized into a 3D mesh composed of a finite number of vertices and edges. But, in some cases, the initial model may be lost or unavailable. In other cases, the 3D discrete representation may be modified, for example after a numerical simulation, and does not correspond anymore to the initial model. A reverse engineering method is then required to reconstruct a 3D continuous representation from the discrete one. In previous work, we have presented a new approach for 3D geometric primitive extraction. In this paper, to complete our automatic and comprehensive reverse engineering process, we propose a method to construct the topology of the retrieved object. To reconstruct a B-Rep model, a new formalism is now introduced to define the adjacency relations. Then a new process is used to construct the boundaries of the object. The whole process is tested on 3D industrial meshes and bring a solution to recover B-Rep models.

Exact solutions for unsteady free convection flow over an oscillating plate due to non-coaxial rotation.

PubMed

Mohamad, Ahmad Qushairi; Khan, Ilyas; Ismail, Zulkhibri; Shafie, Sharidan

2016-01-01

Non-coaxial rotation has wide applications in engineering devices, e.g. in food processing such as mixer machines and stirrers with a two-axis kneader, in cooling turbine blades, jet engines, pumps and vacuum cleaners, in designing thermal syphon tubes, and in geophysical flows. Therefore, this study aims to investigate unsteady free convection flow of viscous fluid due to non-coaxial rotation and fluid at infinity over an oscillating vertical plate with constant wall temperature. The governing equations are modelled by a sudden coincidence of the axes of a disk and the fluid at infinity rotating with uniform angular velocity, together with initial and boundary conditions. Some suitable non-dimensional variables are introduced. The Laplace transform method is used to obtain the exact solutions of the corresponding non-dimensional momentum and energy equations with conditions. Solutions of the velocity for cosine and sine oscillations as well as for temperature fields are obtained and displayed graphically for different values of time ( t ), the Grashof number ( Gr ), the Prandtl number ([Formula: see text]), and the phase angle ([Formula: see text]). Skin friction and the Nusselt number are also evaluated. The exact solutions are obtained and in limiting cases, the present solutions are found to be identical to the published results. Further, the obtained exact solutions also validated by comparing with results obtained by using Gaver-Stehfest algorithm. The interested physical property such as velocity, temperature, skin friction and Nusselt number are affected by the embedded parameters time ( t ), the Grashof number ( Gr ), the Prandtl number ([Formula: see text]), and the phase angle ([Formula: see text]).

Hand-in-hand advances in biomedical engineering and sensorimotor restoration.

PubMed

Pisotta, Iolanda; Perruchoud, David; Ionta, Silvio

2015-05-15

Living in a multisensory world entails the continuous sensory processing of environmental information in order to enact appropriate motor routines. The interaction between our body and our brain is the crucial factor for achieving such sensorimotor integration ability. Several clinical conditions dramatically affect the constant body-brain exchange, but the latest developments in biomedical engineering provide promising solutions for overcoming this communication breakdown. The ultimate technological developments succeeded in transforming neuronal electrical activity into computational input for robotic devices, giving birth to the era of the so-called brain-machine interfaces. Combining rehabilitation robotics and experimental neuroscience the rise of brain-machine interfaces into clinical protocols provided the technological solution for bypassing the neural disconnection and restore sensorimotor function. Based on these advances, the recovery of sensorimotor functionality is progressively becoming a concrete reality. However, despite the success of several recent techniques, some open issues still need to be addressed. Typical interventions for sensorimotor deficits include pharmaceutical treatments and manual/robotic assistance in passive movements. These procedures achieve symptoms relief but their applicability to more severe disconnection pathologies is limited (e.g. spinal cord injury or amputation). Here we review how state-of-the-art solutions in biomedical engineering are continuously increasing expectances in sensorimotor rehabilitation, as well as the current challenges especially with regards to the translation of the signals from brain-machine interfaces into sensory feedback and the incorporation of brain-machine interfaces into daily activities. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Adding a Regenerator to Kornhauser's MIT "Two-Space" (Gas-Spring+Heat Exchanger) Test Rig

NASA Technical Reports Server (NTRS)

Ebiana, Asuquo B.; Gidugu, Praveen

2008-01-01

This study employed entropy-based second law post-processing analysis to characterize the various thermodynamic losses inside a 3-space solution domain (gas spring+heat exchanger+regenerator) operating under conditions of oscillating pressure and oscillating flow. The 3- space solution domain is adapted from the 2-space solution domain (gas spring+heat exchanger) in Kornhauser's MIT test rig by modifying the heat exchanger space to include a porous regenerator system. A thermal nonequilibrium model which assumes that the regenerator porous matrix and gas average temperatures can differ by several degrees at a given axial location and time during the cycle is employed. An important and primary objective of this study is the development and application of a thermodynamic loss post-processor to characterize the major thermodynamic losses inside the 3-space model. It is anticipated that the experience gained from thermodynamic loss analysis of the simple 3-space model can be extrapolated to more complex systems like the Stirling engine. It is hoped that successful development of loss post-processors will facilitate the improvement of the optimization capability of Stirling engine analysis codes through better understanding of the heat transfer and power losses. It is also anticipated that the incorporation of a successful thermal nonequilibrium model of the regenerator in Stirling engine CFD analysis codes, will improve our ability to accurately model Stirling regenerators relative to current multidimensional thermal-equilibrium porous media models.

Selecting the Parameters of the Orientation Engine for a Technological Spacecraft

NASA Astrophysics Data System (ADS)

Belousov, A. I.; Sedelnikov, A. V.

2018-01-01

This work provides a solution to the issues of providing favorable conditions for carrying out gravitationally sensitive technological processes on board a spacecraft. It is noted that an important role is played by the optimal choice of the orientation system of the spacecraft and the main parameters of the propulsion system as the most important executive organ of the system of orientation and control of the orbital motion of the spacecraft. Advantages and disadvantages of two different orientation systems are considered. One of them assumes the periodic impulsive inclusion of a low thrust liquid rocket engines, the other is based on the continuous operation of the executing elements. A conclusion is drawn on the need to take into account the composition of gravitationally sensitive processes when choosing the orientation system of the spacecraft.

Human Factors and Information Operation for a Nuclear Power Space Vehicle

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.; Brown-VanHoozer, S. Alenka

2002-01-01

This paper describes human-interactive systems needed for a crewed nuclear-enabled space mission. A synthesis of aircraft engine and nuclear power plant displays, biofeedback of sensory input, virtual control, brain mapping for control process and manipulation, and so forth are becoming viable solutions. These aspects must maintain the crew's situation awareness and performance, which entails a delicate function allocation between crew and automation.

Problem Solution Processes of Musicians and Engineers: What Do Their Approaches Look Like?

ERIC Educational Resources Information Center

Nissilä, Säde-Pirkko; Virkkula, Esa

2015-01-01

PBL is learning through becoming conscious of practical and abstract problems and finding ways how to solve them. It can be a pattern which doesn't follow traditional divisions of disciplines. In this article the material was collected from two, in the first sight, very different groups. One was music students (N = 62) who had to learn to solve…

How to Motivate Students to Work in the Laboratory: A New Approach for an Electrical Machines Laboratory

ERIC Educational Resources Information Center

Saavedra Montes, A. J.; Botero Castro, H. A.; Hernandez Riveros, J. A.

2010-01-01

Many laboratory courses have become iterative processes in which students only seek to meet the requirements and pass the course. Some students believe these courses are boring and do not give them training as engineers. To provide a solution to the poor motivation of students in laboratories with few resources, this work proposes the method…

Advances in Integrated Computational Materials Engineering "ICME"

NASA Astrophysics Data System (ADS)

Hirsch, Jürgen

The methods of Integrated Computational Materials Engineering that were developed and successfully applied for Aluminium have been constantly improved. The main aspects and recent advances of integrated material and process modeling are simulations of material properties like strength and forming properties and for the specific microstructure evolution during processing (rolling, extrusion, annealing) under the influence of material constitution and process variations through the production process down to the final application. Examples are discussed for the through-process simulation of microstructures and related properties of Aluminium sheet, including DC ingot casting, pre-heating and homogenization, hot and cold rolling, final annealing. New results are included of simulation solution annealing and age hardening of 6xxx alloys for automotive applications. Physically based quantitative descriptions and computer assisted evaluation methods are new ICME methods of integrating new simulation tools also for customer applications, like heat affected zones in welding of age hardening alloys. The aspects of estimating the effect of specific elements due to growing recycling volumes requested also for high end Aluminium products are also discussed, being of special interest in the Aluminium producing industries.

A novel particle engineering technology to enhance dissolution of poorly water soluble drugs: spray-freezing into liquid.

PubMed

Rogers, True L; Nelsen, Andrew C; Hu, Jiahui; Brown, Judith N; Sarkari, Marazban; Young, Timothy J; Johnston, Keith P; Williams, Robert O

2002-11-01

A novel cryogenic spray-freezing into liquid (SFL) process was developed to produce microparticulate powders consisting of an active pharmaceutical ingredient (API) molecularly embedded within a pharmaceutical excipient matrix. In the SFL process, a feed solution containing the API was atomized beneath the surface of a cryogenic liquid such that the liquid-liquid impingement between the feed and cryogenic liquids resulted in intense atomization into microdroplets, which were frozen instantaneously into microparticles. The SFL micronized powder was obtained following lyophilization of the frozen microparticles. The objective of this study was to develop a particle engineering technology to produce micronized powders of the hydrophobic drug, danazol, complexed with hydroxypropyl-beta-cyclodextrin (HPbetaCD) and to compare these SFL micronized powders to inclusion complex powders produced from other techniques, such as co-grinding of dry powder mixtures and lyophilization of bulk solutions. Danazol and HPbetaCD were dissolved in a water/tetrahydrofuran cosolvent mixture prior to SFL processing or slow freezing. Identical quantities of the API and HPbetaCD used in the solutions were co-ground in a mortar and pestle and blended to produce a co-ground physical mixture for comparison. The powder samples were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), scanning electron microscopy, surface area analysis, and dissolution testing. The results provided by DSC, XRD, and FTIR suggested the formation of inclusion complexes by both slow-freezing and SFL. However, the specific surface area was significantly higher for the latter. Dissolution results suggested that equilibration of the danazol/HPbetaCD solution prior to SFL processing was required to produce the most soluble conformation of the resulting inclusion complex following SFL. SFL micronized powders exhibited better dissolution profiles than the slowly frozen aggregate powder. Results indicated that micronized SFL inclusion complex powders dissolved faster in aqueous dissolution media than inclusion complexes formed by conventional techniques due to higher surface areas and stabilized inclusion complexes obtained by ultra-rapid freezing.

Engineering and public health at CDC.

PubMed

Earnest, G Scott; Reed, Laurence D; Conover, D; Estill, C; Gjessing, C; Gressel, M; Hall, R; Hudock, S; Hudson, H; Kardous, C; Sheehy, J; Topmiller, J; Trout, D; Woebkenberg, M; Amendola, A; Hsiao, H; Keane, P; Weissman, D; Finfinger, G; Tadolini, S; Thimons, E; Cullen, E; Jenkins, M; McKibbin, R; Conway, G; Husberg, B; Lincoln, J; Rodenbeck, S; Lantagne, D; Cardarelli, J

2006-12-22

Engineering is the application of scientific and technical knowledge to solve human problems. Using imagination, judgment, and reasoning to apply science, technology, mathematics, and practical experience, engineers develop the design, production, and operation of useful objects or processes. During the 1940s, engineers dominated the ranks of CDC scientists. In fact, the first CDC director, Assistant Surgeon General Mark Hollis, was an engineer. CDC engineers were involved in malaria control through the elimination of standing water. Eventually the CDC mission expanded to include prevention and control of dengue, typhus, and other communicable diseases. The development of chlorination, water filtration, and sewage treatment were crucial to preventing waterborne illness. Beginning in the 1950s, CDC engineers began their work to improve public health while developing the fields of environmental health, industrial hygiene, and control of air pollution. Engineering disciplines represented at CDC today include biomedical, civil, chemical, electrical, industrial, mechanical, mining, and safety engineering. Most CDC engineers are located in the National Institute for Occupational Safety and Health (NIOSH) and the Agency for Toxic Substances and Disease Registry (ATSDR). Engineering research at CDC has a broad stakeholder base. With the cooperation of industry, labor, trade associations, and other stakeholders and partners, current work includes studies of air contaminants, mining, safety, physical agents, ergonomics, and environmental hazards. Engineering solutions remain a cornerstone of the traditional "hierarchy of controls" approach to reducing public health hazards.

A Phenomenographic Investigation of the Ways Engineering Students Experience Innovation

NASA Astrophysics Data System (ADS)

Fila, Nicholas David

Innovation has become an important phenomenon in engineering and engineering education. By developing novel, feasible, viable, and valued solutions to complex technical and human problems, engineers support the economic competitiveness of organizations, make a difference in the lives of users and other stakeholders, drive societal and scientific progress, and obtain key personal benefits. Innovation is also a complex phenomenon. It occurs across a variety of contexts and domains, encompasses numerous phases and activities, and requires unique competency profiles. Despite this complexity, many studies in engineering education focus on specific aspects (e.g., engineering students' abilities to generate original concepts during idea generation), and we still know little about the variety of ways engineering students approach and understand innovation. This study addresses that gap by asking: 1. What are the qualitatively different ways engineering students experience innovation during their engineering projects? 2. What are the structural relationships between the ways engineering students experience innovation? This study utilized phenomenography, a qualitative research method, to explore the above research questions. Thirty-three engineering students were recruited to ensure thorough coverage along four factors suggested by the literature to support differences related to innovation: engineering project experience, academic major, year in school, and gender. Each participant completed a 1-2 hour, semi-structured interview that focused on experiences with and conceptions of innovation. Whole transcripts were analyzed using an eight-stage, iterative, and comparative approach meant to identify a limited number of categories of description (composite ways of experiencing innovation comprised of the experiences of several participants), and the structural relationships between these categories. Phenomenographic analysis revealed eight categories of description that were structured in a semi-hierarchical, two-dimensional outcome space. The first four categories demonstrated a progression toward greater comprehensiveness in both process and focus dimensions. In the process dimension, subsequent categories added increasingly preliminary innovation phases: idea realization, idea generation, problem scoping, and problem finding. In the focus dimension, subsequent categories added key areas engineers considered during innovation: technical, human, and enterprise. The final four categories each incorporated all previous process phases and focus areas, but prioritized different focus areas in sophisticated ways and acknowledged a macro-iterative cycle, i.e., an understanding of how the processes within a single innovation project built upon and contributed to past and future innovation projects. These results demonstrate important differences between engineering students and suggest how they may come to experience innovation in increasingly comprehensive ways. A framework based on the results can be used by educators and researchers to support more robust educational offerings and nuanced research designs that reflect these differences.

Composition and Process for Retarding the Premature Aging of PMR Monomer Solutions and PMR Prepegs

NASA Technical Reports Server (NTRS)

Alston, William B. (Inventor); Gahn, Gloria S. (Inventor)

2000-01-01

Polyimides are derived from solutions of at least one low-boiling organic solvent, e.g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80 C, and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the esteracids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

Electrochemical Polishing Applications and EIS of a Novel Choline Chloride-Based Ionic Liquid

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

Wixtrom, Alex I.; Buhler, Jessica E.; Reece, Charles E.

2013-06-01

Minimal surface roughness is a critical feature for high-field superconducting radio frequency (SRF) cavities used to engineer particle accelerators. Current methods for polishing Niobium cavities typically utilize solutions containing a mixture of concentrated sulfuric and hydrofluoric acid. Polishing processes such as these are effective, yet there are many hazards and costs associated with the use (and safe disposal) of the concentrated acid solutions. An alternative method for electrochemical polishing of the cavities was explored using a novel ionic liquid solution containing choline chloride. Potentiostatic electrochemical impedance spectroscopy (EIS) was used to analyze the ionic polishing solution. Final surface roughness ofmore » the Nb was found to be comparable to that of the acid-polishing method, as assessed by atomic force microscopy (AFM). This indicates that ionic liquid-based electrochemical polishing of Nb is a viable replacement for acid-based methods for preparation of SRF cavities.« less

Rewilding as nature based solution in land management

NASA Astrophysics Data System (ADS)

Novara, Agata; Gristina, Luciano; Keesstra, Saskia; Pereira, Paulo; Cerda, Artemio

2017-04-01

Rewilding is an effective tool of ecological restoration and a nature based solution for hydro-meteorological risk control. Rewilding contributes to reduce flood risk, resist droughts, helps to restore soil organic matter content, increases soil and plant biodiversity, improves the overall ecosystem and human health. The key element of rewilding is not the nature control, but following the natural processes to restore the key soil ecological factors and their connectivity. Rewilding can be applicable at different ecosystem stages, from natural reserve to more anthropogenic system such as agricultural land through the restoration of wild soil function trough permaculture or forest farming. The proposed nature based solution not only avoid the investment in traditional engineering but it also an opportunities for creating new economics model based on wild nature (ecoturism, education, wild edible plants). This work is a review of applied rewilding actions and considerations on future nature based solutions applications will be discussed .

A History of Aerospace Problems, Their Solutions, Their Lessons

NASA Technical Reports Server (NTRS)

Ryan, R. S.

1996-01-01

The positive aspect of problem occurrences is the opportunity for learning and a challenge for innovation. The learning aspect is not restricted to the solution period of the problem occurrence, but can become the beacon for problem prevention on future programs. Problems/failures serve as a point of departure for scaling to new designs. To ensure that problems/failures and their solutions guide the future programs, a concerted effort has been expended to study these problems, their solutions, their derived lessons learned, and projections for future programs. This includes identification of technology thrusts, process changes, codes development, etc. However, they must not become an excuse for adding layers upon layers of standards, criteria, and requirements, but must serve as guidelines that assist instead of stifling engineers. This report is an extension of prior efforts to accomplish this task. Although these efforts only scratch the surface, it is a beginning that others must complete.

Increase in the efficiency of a high-speed ramjet on hydrocarbon fuel at the flying vehicle acceleration up to M = 6+

NASA Astrophysics Data System (ADS)

Abashev, V. M.; Korabelnikov, A. V.; Kuranov, A. L.; Tretyakov, P. K.

2017-10-01

At the analysis of the work process in a ramjet, a complex consideration of the ensemble of problems the solution of which determines the engine efficiency appears reasonable. The main problems are ensuring a high completeness of fuel combustion and minimal hydraulic losses, the reliability of cooling of high-heat areas with the use of the fuel cooling resource, and ensuring the strength of the engine duct elements under non-uniform heat loads due to fuel combustion in complex gas-dynamic flow structures. The fundamental techniques and approaches to the solution of above-noted problems are considered in the present report, their novelty and advantages in comparison with conventional techniques are substantiated. In particular, a technique of the arrangement of an intense (pre-detonation) combustion regime for ensuring a high completeness of fuel combustion and minimal hydraulic losses at a smooth deceleration of a supersonic flow down to the sound velocity using the pulsed-periodic gas-dynamic flow control has been proposed. A technique has been proposed for cooling the high-heat areas, which employs the cooling resource of the hydrocarbon fuel, including the process of the kerosene chemical transformation (conversion) using the nano-catalysts. An analysis has shown that the highly heated structure will operate in the elastic-plastic domain of the behavior of constructional materials, which is directly connected to the engine operation resource. There arise the problems of reducing the ramjet shells depending on deformations. The deformations also lead to a significant influence on the work process in the combustor and, naturally, on the heat transfer process and the performance of catalysts (the action of plastic and elastic deformations of restrained shells). The work presents some results illustrating the presence of identified problems. A conclusion is drawn about the necessity of formulating a complex investigation both with the realization in model experiments and execution of computational and theoretical investigations.

How smart is your BEOL? productivity improvement through intelligent automation

NASA Astrophysics Data System (ADS)

Schulz, Kristian; Egodage, Kokila; Tabbone, Gilles; Garetto, Anthony

2017-07-01

The back end of line (BEOL) workflow in the mask shop still has crucial issues throughout all standard steps which are inspection, disposition, photomask repair and verification of repair success. All involved tools are typically run by highly trained operators or engineers who setup jobs and recipes, execute tasks, analyze data and make decisions based on the results. No matter how experienced operators are and how good the systems perform, there is one aspect that always limits the productivity and effectiveness of the operation: the human aspect. Human errors can range from seemingly rather harmless slip-ups to mistakes with serious and direct economic impact including mask rejects, customer returns and line stops in the wafer fab. Even with the introduction of quality control mechanisms that help to reduce these critical but unavoidable faults, they can never be completely eliminated. Therefore the mask shop BEOL cannot run in the most efficient manner as unnecessary time and money are spent on processes that still remain labor intensive. The best way to address this issue is to automate critical segments of the workflow that are prone to human errors. In fact, manufacturing errors can occur for each BEOL step where operators intervene. These processes comprise of image evaluation, setting up tool recipes, data handling and all other tedious but required steps. With the help of smart solutions, operators can work more efficiently and dedicate their time to less mundane tasks. Smart solutions connect tools, taking over the data handling and analysis typically performed by operators and engineers. These solutions not only eliminate the human error factor in the manufacturing process but can provide benefits in terms of shorter cycle times, reduced bottlenecks and prediction of an optimized workflow. In addition such software solutions consist of building blocks that seamlessly integrate applications and allow the customers to use tailored solutions. To accommodate for the variability and complexity in mask shops today, individual workflows can be supported according to the needs of any particular manufacturing line with respect to necessary measurement and production steps. At the same time the efficiency of assets is increased by avoiding unneeded cycle time and waste of resources due to the presence of process steps that are very crucial for a given technology. In this paper we present details of which areas of the BEOL can benefit most from intelligent automation, what solutions exist and the quantification of benefits to a mask shop with full automation by the use of a back end of line model.

Product Lifecycle Management and the Quest for Sustainable Space Explorations

NASA Technical Reports Server (NTRS)

Caruso, Pamela W.; Dumbacher, Daniel L.

2010-01-01

Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Engineering Directorate at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center, total lifecycle costs are important variables for critical decision-making. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful concept to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This paper will demonstrate how the Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions. It has been 30 years since the United States fielded the Space Shuttle. The next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. The outcome is a better use of scarce resources, along with more focus on stakeholder and customer requirements, as a new portfolio of enabling tools becomes second nature to the workforce. This paper will use the design and manufacturing processes, which have transitioned to digital-based activities, to show how PLM supports the comprehensive systems engineering and integration function. It also will go through a launch countdown scenario where an anomaly is detected to show how the virtual vehicle created from paperless processes will help solve technical challenges and improve the likelihood of launching on schedule, with less hands-on labor needed for processing and troubleshooting.

Analysis of biomass and waste gasification lean syngases combustion for power generation using spark ignition engines.

PubMed

Marculescu, Cosmin; Cenuşă, Victor; Alexe, Florin

2016-01-01

The paper presents a study for food processing industry waste to energy conversion using gasification and internal combustion engine for power generation. The biomass we used consisted in bones and meat residues sampled directly from the industrial line, characterised by high water content, about 42% in mass, and potential health risks. Using the feedstock properties, experimentally determined, two air-gasification process configurations were assessed and numerically modelled to quantify the effects on produced syngas properties. The study also focused on drying stage integration within the conversion chain: either external or integrated into the gasifier. To comply with environmental regulations on feedstock to syngas conversion both solutions were developed in a closed system using a modified down-draft gasifier that integrates the pyrolysis, gasification and partial oxidation stages. Good quality syngas with up to 19.1% - CO; 17% - H2; and 1.6% - CH4 can be produced. The syngas lower heating value may vary from 4.0 MJ/Nm(3) to 6.7 MJ/Nm(3) depending on process configuration. The influence of syngas fuel properties on spark ignition engines performances was studied in comparison to the natural gas (methane) and digestion biogas. In order to keep H2 molar quota below the detonation value of ⩽4% for the engines using syngas, characterised by higher hydrogen fraction, the air excess ratio in the combustion process must be increased to [2.2-2.8]. The results in this paper represent valuable data required by the design of waste to energy conversion chains with intermediate gas fuel production. The data is suitable for Otto engines characterised by power output below 1 MW, designed for natural gas consumption and fuelled with low calorific value gas fuels. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prediction of ice content in biological model solutions when frozen under high pressure.

PubMed

Guignon, B; Aparicio, C; Otero, L; Sanz, P D

2009-01-01

High pressure is, at least, as effective as cryoprotective agents (CPAs) and are used for decreasing both homogenous nucleation and freezing temperatures. This fact gives rise to a great variety of possible cryopreservation processes under high pressure. They have not been optimized yet, since they are relatively recent and are mainly based on the pressure-temperature phase diagram of pure water. Very few phase diagrams of biological material are available under pressure. This is owing to the lack of suitable equipment and to the difficulties encountered in carrying out the measurements. Different aqueous solutions of salt and CPAs as biological models are studied in the range of 0 degrees C down to -35 degrees C, 0.1 up to 250 MPa, and 0-20% w/w total solute concentration. The phase transition curves of glycerol and of sodium chloride with either glycerol or sucrose in aqueous solutions are determined in a high hydrostatic pressure vessel. The experimental phase diagrams of binary solutions were well described by a third-degree polynomial equation. It was also shown that Robinson and Stokes' equation at high pressure succeeds in predicting the phase diagrams of both binary and ternary solutions. The solute cryoconcentration and the ice content were calculated as a function of temperature and pressure conditions during the freezing of a binary solution. This information should provide a basis upon which high-pressure cryopreservation processes may be performed and the damages derived from ice formation evaluated. (c) 2009 American Institute of Chemical Engineers Biotechnol.

Materials, device, and interface engineering to improve polymer-based solar cells

NASA Astrophysics Data System (ADS)

Hau, Steven Kin

The continued depletion of fossil fuel resources has lead to the rise in energy production costs which has lead to the search for an economically viable alternative energy source. One alternative of particular interest is solar energy. A promising alternative to inorganic materials is organic semiconductor polymer solar cells due to their advantages of being cheaper, light weight, flexible and made into large areas by roll-to-roll processing. In this dissertation, an integrated approach is taken to improve the overall performance of polymer-based solar cells by the development of new polymer materials, device architectures, and interface engineering of the contacts between layers. First, a new class of metallated conjugated polymers is explored as potential solar cell materials. Systematic modifications to the molecular units on the main chain of amorphous metallated Pt-polymers show a correlation that improving charge carrier mobility also improves solar cell performance leading to mobilities as high as 1 x 10-2 cm2/V·s and efficiencies as high as 4.1%. Second, an inverted device architecture using a more air stable electrode (Ag) is demonstrated to improve the ambient stability of unencapsulated P3HT:PCBM devices showing over 80% efficiency retention after 40 days of exposure. To further demonstrate the potential for roll-to-roll processing of polymer solar cells, solution processed Ag-nanoparticles were used to replace the vacuum deposited Ag anode electrode for inverted solar cells showing efficiencies as high as 3%. In addition, solution processed polymer based electrodes were demonstrated as a replacement to the expensive and brittle indium tin oxide showing efficiencies of 3% on flexible substrate solar cells. Third, interface engineering of the n-type (high temperature sol-gel processed TiO2 or ZnO, low temperature processed ZnO nanoparticles) electron selective metal oxide contacts in inverted solar cells with self-assembled monolayers (SAM) show improved device performance. Modifying the n-type layer in inverted cells with C60-SAMs containing different anchoring groups leads to an improvement in photocurrent density and fill factor leading to efficiencies as high as 4.9%.

The Use of Lotus 1-2-3 Macros in Engineering Calculations.

ERIC Educational Resources Information Center

Rosen, Edward M.

1990-01-01

Described are the use of spreadsheet programs in chemical engineering calculations using Lotus 1-2-3 macros. Discusses the macro commands, subroutine operations, and solution of partial differential equation. Provides examples of the subroutine programs and spreadsheet solution. (YP)

TEMPEST: A computer code for three-dimensional analysis of transient fluid dynamics

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

Fort, J.A.

TEMPEST (Transient Energy Momentum and Pressure Equations Solutions in Three dimensions) is a powerful tool for solving engineering problems in nuclear energy, waste processing, chemical processing, and environmental restoration because it analyzes and illustrates 3-D time-dependent computational fluid dynamics and heat transfer analysis. It is a family of codes with two primary versions, a N- Version (available to public) and a T-Version (not currently available to public). This handout discusses its capabilities, applications, numerical algorithms, development status, and availability and assistance.

Fully Integral, Flexible Composite Driveshaft

NASA Technical Reports Server (NTRS)

Lawrie, Duncan

2014-01-01

An all-composite driveshaft incorporating integral flexible diaphragms was developed for prime contractor testing. This new approach makes obsolete the split lines required to attach metallic flex elements and either metallic or composite spacing tubes in current solutions. Subcritical driveshaft weights can be achieved that are half that of incumbent technology for typical rotary wing shaft lengths. Spacing tubes compose an integral part of the initial tooling but remain part of the finished shaft and control natural frequencies and torsional stability. A concurrently engineered manufacturing process and design for performance competes with incumbent solutions at significantly lower weight and with the probability of improved damage tolerance and fatigue life.

Aerodynamics of Engine-Airframe Interaction

NASA Technical Reports Server (NTRS)

Caughey, D. A.

1986-01-01

The report describes progress in research directed towards the efficient solution of the inviscid Euler and Reynolds-averaged Navier-Stokes equations for transonic flows through engine inlets, and past complete aircraft configurations, with emphasis on the flowfields in the vicinity of engine inlets. The research focusses upon the development of solution-adaptive grid procedures for these problems, and the development of multi-grid algorithms in conjunction with both, implicit and explicit time-stepping schemes for the solution of three-dimensional problems. The work includes further development of mesh systems suitable for inlet and wing-fuselage-inlet geometries using a variational approach. Work during this reporting period concentrated upon two-dimensional problems, and has been in two general areas: (1) the development of solution-adaptive procedures to cluster the grid cells in regions of high (truncation) error;and (2) the development of a multigrid scheme for solution of the two-dimensional Euler equations using a diagonalized alternating direction implicit (ADI) smoothing algorithm.

University of Colorado CubeSat Student Projects as Successful Model for Teaching Students about Engineering Practices

NASA Astrophysics Data System (ADS)

Palo, S. E.; Li, X.; Woods, T. N.; Kohnert, R.

2014-12-01

There is a long history of cooperation between students at the University of Colorado, Boulder and professional engineers and scientists at LASP, which has led to many successful space missions with direct student involvement. The recent student-led missions include the Student Nitric Oxide Explorer (SNOE, 1998 - 2002), the Student Dust Counter (SDC) on New Horizons (2006 - present), the Colorado Student Space Weather Experiment (CSSWE), being a very successful NSF CubeSat that launched in September 2012, and the NASA Miniature X-ray Solar Spectrometer (MinXSS) CubeSat (launch will be in early 2015). Students are involved in all aspects of the design, and they experience the full scope of the mission process from concept, to fabrication and test, and mission operations. A significant part of the student involvement in the CubeSat projects is gained by using the CubeSat development as a focal point for an existing two-semester course sequence in CU's Aerospace Engineering Sciences (AES) Department: the Space Hardware Design section of Graduate Projects I & II (ASEN 5018 & ASEN 6028). The goal of these courses is to teach graduate students how to design and build systems using a requirement-based approach and fundamental systems engineering practices. The two-semester sequence takes teams of about 15 students from requirements definition and preliminary design through manufacturing, integration, and testing. In addition to the design process, students learn key professional skills such as working effectively in groups, finding solutions to open-ended problems, and actually building a system to their own set of specifications. The partnership between AES and LASP allows us to include engineering professionals in the mix, thus more effectively training science and engineering students for future roles in the civilian or commercial space industry. The mentoring process with LASP engineers helps to mitigate risk of the inexperience of the students and ensures consistent system engineer oversight for the multi-year CubeSat programs.

Parallel processing for scientific computations

NASA Technical Reports Server (NTRS)

Alkhatib, Hasan S.

1991-01-01

The main contribution of the effort in the last two years is the introduction of the MOPPS system. After doing extensive literature search, we introduced the system which is described next. MOPPS employs a new solution to the problem of managing programs which solve scientific and engineering applications on a distributed processing environment. Autonomous computers cooperate efficiently in solving large scientific problems with this solution. MOPPS has the advantage of not assuming the presence of any particular network topology or configuration, computer architecture, or operating system. It imposes little overhead on network and processor resources while efficiently managing programs concurrently. The core of MOPPS is an intelligent program manager that builds a knowledge base of the execution performance of the parallel programs it is managing under various conditions. The manager applies this knowledge to improve the performance of future runs. The program manager learns from experience.

Continuous adjustment of threshold voltage in carbon nanotube field-effect transistors through gate engineering

NASA Astrophysics Data System (ADS)

Zhong, Donglai; Zhao, Chenyi; Liu, Lijun; Zhang, Zhiyong; Peng, Lian-Mao

2018-04-01

In this letter, we report a gate engineering method to adjust threshold voltage of carbon nanotube (CNT) based field-effect transistors (FETs) continuously in a wide range, which makes the application of CNT FETs especially in digital integrated circuits (ICs) easier. Top-gated FETs are fabricated using solution-processed CNT network films with stacking Pd and Sc films as gate electrodes. By decreasing the thickness of the lower layer metal (Pd) from 20 nm to zero, the effective work function of the gate decreases, thus tuning the threshold voltage (Vt) of CNT FETs from -1.0 V to 0.2 V. The continuous adjustment of threshold voltage through gate engineering lays a solid foundation for multi-threshold technology in CNT based ICs, which then can simultaneously provide high performance and low power circuit modules on one chip.

[Time-evolution study on the cation exchange in the process of reinforcing slip soil by laser-induced breakdown spectroscopy].

PubMed

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.

Preparing synthetic biology for the world

PubMed Central

Moe-Behrens, Gerd H. G.; Davis, Rene; Haynes, Karmella A.

2013-01-01

Synthetic Biology promises low-cost, exponentially scalable products and global health solutions in the form of self-replicating organisms, or “living devices.” As these promises are realized, proof-of-concept systems will gradually migrate from tightly regulated laboratory or industrial environments into private spaces as, for instance, probiotic health products, food, and even do-it-yourself bioengineered systems. What additional steps, if any, should be taken before releasing engineered self-replicating organisms into a broader user space? In this review, we explain how studies of genetically modified organisms lay groundwork for the future landscape of biosafety. Early in the design process, biological engineers are anticipating potential hazards and developing innovative tools to mitigate risk. Here, we survey lessons learned, ongoing efforts to engineer intrinsic biocontainment, and how different stakeholders in synthetic biology can act to accomplish best practices for biosafety. PMID:23355834

Neural network potential for Al-Mg-Si alloys

NASA Astrophysics Data System (ADS)

Kobayashi, Ryo; Giofré, Daniele; Junge, Till; Ceriotti, Michele; Curtin, William A.

2017-10-01

The 6000 series Al alloys, which include a few percent of Mg and Si, are important in automotive and aviation industries because of their low weight, as compared to steels, and the fact their strength can be greatly improved through engineered precipitation. To enable atomistic-level simulations of both the processing and performance of this important alloy system, a neural network (NN) potential for the ternary Al-Mg-Si has been created. Training of the NN uses an extensive database of properties computed using first-principles density functional theory, including complex precipitate phases in this alloy. The NN potential accurately reproduces most of the pure Al properties relevant to the mechanical behavior as well as heat of solution, solute-solute, and solute-vacancy interaction energies, and formation energies of small solute clusters and precipitates that are required for modeling the early stage of precipitation and mechanical strengthening. This success not only enables future detailed studies of Al-Mg-Si but also highlights the ability of NN methods to generate useful potentials in complex alloy systems.

Optimization in optical systems revisited: Beyond genetic algorithms

NASA Astrophysics Data System (ADS)

Gagnon, Denis; Dumont, Joey; Dubé, Louis

2013-05-01

Designing integrated photonic devices such as waveguides, beam-splitters and beam-shapers often requires optimization of a cost function over a large solution space. Metaheuristics - algorithms based on empirical rules for exploring the solution space - are specifically tailored to those problems. One of the most widely used metaheuristics is the standard genetic algorithm (SGA), based on the evolution of a population of candidate solutions. However, the stochastic nature of the SGA sometimes prevents access to the optimal solution. Our goal is to show that a parallel tabu search (PTS) algorithm is more suited to optimization problems in general, and to photonics in particular. PTS is based on several search processes using a pool of diversified initial solutions. To assess the performance of both algorithms (SGA and PTS), we consider an integrated photonics design problem, the generation of arbitrary beam profiles using a two-dimensional waveguide-based dielectric structure. The authors acknowledge financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC).

Methodology of problem-based learning engineering and technology and of its implementation with modern computer resources

NASA Astrophysics Data System (ADS)

Lebedev, A. A.; Ivanova, E. G.; Komleva, V. A.; Klokov, N. M.; Komlev, A. A.

2017-01-01

The considered method of learning the basics of microelectronic circuits and systems amplifier enables one to understand electrical processes deeper, to understand the relationship between static and dynamic characteristics and, finally, bring the learning process to the cognitive process. The scheme of problem-based learning can be represented by the following sequence of procedures: the contradiction is perceived and revealed; the cognitive motivation is provided by creating a problematic situation (the mental state of the student), moving the desire to solve the problem, to raise the question "why?", the hypothesis is made; searches for solutions are implemented; the answer is looked for. Due to the complexity of architectural schemes in the work the modern methods of computer analysis and synthesis are considered in the work. Examples of engineering by students in the framework of students' scientific and research work of analog circuits with improved performance based on standard software and software developed at the Department of Microelectronics MEPhI.

The design, fabrication and characterization of fluidic membranes for micro-engines with the aim of frequency lowering

NASA Astrophysics Data System (ADS)

Chutani, R.; Formosa, F.; de Labachelerie, M.; Badel, A.; Lanzetta, F.

2016-12-01

This paper describes the design, microfabrication and linear dynamic characterization of low frequency thick membranes as a potential technological solution for resonant micro-engines, for which classical pistons cannot be used. The proposed structure is called a hybrid fluid-membrane and consists of two thin flexible membranes that encapsulate an incompressible fluid. Lower frequency structures, compared to geometrically equivalent single layer membranes, are thus obtained. Each flexible membrane is based on a composite structure which comprises a silicon planar logarithmic spiral spring embedded in a room temperature vulcanization silicone polymer. Thus, the stiffness and sealing features are dissociated for a better design control. The developed realization and assembly process is demonstrated at the wafer level. The process involves the anodic bonding of multiple stacks of silicon/glass structures, fluid filling and sealing. Various dimensions of hybrid fluid-membranes are successfully fabricated. Their dynamic characterization underlines the agreement between experimental and theoretical results. The results provide the opportunity for the design and fabrication of low frequency membranes to match the dynamics requirements of micro-engines.

On the Development of an Efficient Parallel Hybrid Solver with Application to Acoustically Treated Aero-Engine Nacelles

NASA Technical Reports Server (NTRS)

Watson, Willie R.; Nark, Douglas M.; Nguyen, Duc T.; Tungkahotara, Siroj

2006-01-01

A finite element solution to the convected Helmholtz equation in a nonuniform flow is used to model the noise field within 3-D acoustically treated aero-engine nacelles. Options to select linear or cubic Hermite polynomial basis functions and isoparametric elements are included. However, the key feature of the method is a domain decomposition procedure that is based upon the inter-mixing of an iterative and a direct solve strategy for solving the discrete finite element equations. This procedure is optimized to take full advantage of sparsity and exploit the increased memory and parallel processing capability of modern computer architectures. Example computations are presented for the Langley Flow Impedance Test facility and a rectangular mapping of a full scale, generic aero-engine nacelle. The accuracy and parallel performance of this new solver are tested on both model problems using a supercomputer that contains hundreds of central processing units. Results show that the method gives extremely accurate attenuation predictions, achieves super-linear speedup over hundreds of CPUs, and solves upward of 25 million complex equations in a quarter of an hour.

Rapid localized deactivation of self-assembled monolayers by propagation-controlled laser-induced plasma and its application to self-patterning of electronics and biosensors

NASA Astrophysics Data System (ADS)

Kim, Jongsu; Kwon, Seung-Gab; Back, Seunghyun; Kang, Bongchul

2018-03-01

We present a novel laser-induced surface treatment process to rapidly control the spatial wettabilities of various functional solutions with submicron to micron resolutions. Ultrathin hydrophobic self-assembled monolayers (SAMs) that little absorb typical laser lights due to short penetration depth were selectively deactivated by instantaneous interaction with laser-induced metallic plasmas. The spatial region of the deactivated SAM, which corresponds to process resolution, is adjustable by controlling the spatial propagation of the plasma. This method leads to the parallel formation of hydrophilic functional solutions on glass substrates with a minimum resolution on the submicron scale. To show its feasibility in device engineering fields, this method was applied to the cost-effective fabrication of electronics and biosensors. Rapid self-patterning of electronic and biological functional solutions (silver nanoparticle solution and streptavidin protein solution) was successfully realized by selective deactivation of two different SAMs (tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) for electronics and the hetero-hybrid SAM (octadecyltrichlorosilane (OTS)/2-[methoxy(polyethyleneoxy)propyl] trichlorosilane (PEG)) for biosensors). As a result, this method can be exploited for the rapid and low-cost fabrication of various thin film devices such as electronics, biosensors, energy, displays, and photonics.

Numerical Analysis of Intra-Cavity and Power-Stream Flow Interaction in Multiple Gas-Turbine Disk-Cavities

NASA Technical Reports Server (NTRS)

Athavale, M. M.; Przekwas, A. J.; Hendricks, R. C.; Steinetz, B. M.

1995-01-01

A numerical analysis methodology and solutions of the interaction between the power stream and multiply-connected multi-cavity sealed secondary flow fields are presented. Flow solutions for a multi-cavity experimental rig were computed and compared with experimental data of Daniels and Johnson. The flow solutions illustrate the complex coupling between the main-path and the cavity flows as well as outline the flow thread that exists throughout the subplatform multiple cavities and seals. The analysis also shows that the de-coupled solutions on single cavities is inadequate. The present results show trends similar to the T-700 engine data that suggests the changes in the CDP seal altered the flow fields throughout the engine and affected the engine performance.

Engineering a Healthier Watershed: Middle School Students Use Engineering Design to Lessen the Impact of Their Campus' Impervious Surfaces on Their Local Watershed

NASA Astrophysics Data System (ADS)

Gardner, Elizabeth Claire

It is important that students understand not only how their local watershed functions, but also how it is being impacted by impervious surfaces. Additionally, students need experience exploring the scientific and engineering practices that are necessary for a strong STEM background. With this knowledge students can be empowered to tackle this real and local problem using engineering design, a powerful practice gaining momentum and clarity through its prominence in the recent Framework for K-12 Science Education. Twenty classes of suburban sixth-graders participated in a new five-week Watershed Engineering Design Unit taught by their regular science teachers. Students engaged in scientific inquiry to learn about the structure, function, and health of their local watersheds, focusing on the effects of impervious surfaces. In small groups, students used the engineering design process to propose solutions to lessen the impact of runoff from their school campuses. The goal of this evaluation was to determine the effectiveness of the curriculum in terms of student gains in understanding of (1) watershed function, (2) the impact of impervious surfaces, and (3) the engineering design process. To determine the impact of this curriculum on their learning, students took multiple-choice pre- and post-assessments made up of items covering the three categories above. This data was analyzed for statistical significance using a lower-tailed paired sample t-test. All three objectives showed statistically significant learning gains and the results were used to recommend improvements to the curriculum and the assessment instrument for future iterations.

Algorithms for the Fractional Calculus: A Selection of Numerical Methods

NASA Technical Reports Server (NTRS)

Diethelm, K.; Ford, N. J.; Freed, A. D.; Luchko, Yu.

2003-01-01

Many recently developed models in areas like viscoelasticity, electrochemistry, diffusion processes, etc. are formulated in terms of derivatives (and integrals) of fractional (non-integer) order. In this paper we present a collection of numerical algorithms for the solution of the various problems arising in this context. We believe that this will give the engineer the necessary tools required to work with fractional models in an efficient way.

Reuse-Driven Software Processes Guidebook. Version 02.00.03

DTIC Science & Technology

1993-11-01

a required sys - tem without unduly constraining the details of the solution. The Naval Research Laboratory Software Cost Reduction project developed...conventional manner. The emphasis is still on the development of "one-of-a-kind" sys - tems and the phased completion and review of corresponding...Application Engineering to improve the life-cycle productivity of Sy - 21 OVM ftrdauntals of Syatbes the total software development enterprise. The

Modeling MultiCoil ICPs

NASA Astrophysics Data System (ADS)

Kolobov, V. I.; Vaidya, N.; Krishnan, A.

1998-10-01

Plasma processing of 300 mm wafers and flat panels places stringent demands on plasma uniformity across large surfaces. A natural solution towards an uniform plasma in a minimum discharge volume is to maintain the plasma by an array of individual sources. Although the design of the individual sources can differ considerably, there is a common feature for all such devices which have been recently suggested by several groups: their essentially 3D geometry. Engineering design of these devices is a challenging task and computational modeling could be a very useful tool. CFD Research Corp. has developed a comprehensive software for virtual prototyping of ICP sources designed for complex 3D geometries with unstructured solution-adaptive mesh. In this paper we shall present the results of our simulation of the multipole high density source [1] which is an example of MultiCoil ICP. We shall describe the procedure of solving the electromagnetic part of the problem using magnetic vector potential and analyse design issues such as the size of dielectric windows. We shall present results of parametric studies of the source for different geometries, gas pressures and plasma densities for simple argon chemistry. [1] J.Ogle. Proc. VI Int. Workshop on Advanced Plasma Tools and Process Engineering, pp. 85-90, May 1998, Millbrae, USA.

Higher Temperature Thermal Barrier Coatings with the Combined Use of Yttrium Aluminum Garnet and the Solution Precursor Plasma Spray Process

NASA Astrophysics Data System (ADS)

Gell, Maurice; Wang, Jiwen; Kumar, Rishi; Roth, Jeffery; Jiang, Chen; Jordan, Eric H.

2018-04-01

Gas-turbine engines are widely used in transportation, energy and defense industries. The increasing demand for more efficient gas turbines requires higher turbine operating temperatures. For more than 40 years, yttria-stabilized zirconia (YSZ) has been the dominant thermal barrier coating (TBC) due to its outstanding material properties. However, the practical use of YSZ-based TBCs is limited to approximately 1200 °C. Developing new, higher temperature TBCs has proven challenging to satisfy the multiple property requirements of a durable TBC. In this study, an advanced TBC has been developed by using the solution precursor plasma spray (SPPS) process that generates unique engineered microstructures with the higher temperature yttrium aluminum garnet (YAG) to produce a TBC that can meet and exceed the major performance standards of state-of-the-art air plasma sprayed YSZ, including: phase stability, sintering resistance, CMAS resistance, thermal cycle durability, thermal conductivity and erosion resistance. The temperature improvement for hot section gas turbine materials (superalloys & TBCs) has been at the rate of about 50 °C per decade over the last 50 years. In contrast, SPPS YAG TBCs offer the near-term potential of a > 200 °C improvement in temperature capability.

SWEET sugar transporters for phloem transport and pathogen nutrition.

PubMed

Chen, Li-Qing

2014-03-01

Many intercellular solute transport processes require an apoplasmic step, that is, efflux from one cell and subsequent uptake by an adjacent cell. Cellular uptake transporters have been identified for many solutes, including sucrose; however, efflux transporters have remained elusive for a long time. Cellular efflux of sugars plays essential roles in many processes, such as sugar efflux as the first step in phloem loading, sugar efflux for nectar secretion, and sugar efflux for supplying symbionts such as mycorrhiza, and maternal efflux for filial tissue development. Furthermore, sugar efflux systems can be hijacked by pathogens for access to nutrition from hosts. Mutations that block recruitment of the efflux mechanism by the pathogen thus cause pathogen resistance. Until recently, little was known regarding the underlying mechanism of sugar efflux. The identification of sugar efflux carriers, SWEETs (Sugars Will Eventually be Exported Transporters), has shed light on cellular sugar efflux. SWEETs appear to function as uniporters, facilitating diffusion of sugars across cell membranes. Indeed, SWEETs probably mediate sucrose efflux from putative phloem parenchyma into the phloem apoplasm, a key step proceeding phloem loading. Engineering of SWEET mutants using transcriptional activator-like effector nuclease (TALEN)-based genomic editing allowed the engineering of pathogen resistance. The widespread expression of the SWEET family promises to provide insights into many other cellular efflux mechanisms.

Development of a novel wet oxidation process for hazardous and mixed wastes

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

Dhooge, P.M.

1994-12-31

Many DOE waste streams and remediates contain complex and variable mixtures of organic compounds, toxic metals, and radionuclides. These materials are often dispersed in organic or inorganic matrices, such as personal protective equipment, various sludges, soils, and water. The over all objective of the effort described here is to develop a novel catalytic wet oxidation process for the treatment of these multi-component wastes, with the aim of providing a versatile, non-thermal method which will destroy hazardous organic compounds while simultaneously containing and concentrating toxic and radioactive metals for recovery or disposal in a readily stabilized matrix. The DETOX process usesmore » a unique combination of metal catalysts to increase the rate of oxidation of organic materials. The metal catalysts are in the form of salts dissolved in a dilute acid solution. A typical catalyst composition is 60% ferric chloride, 3--4% hydrochloric acid, 0.13% platinum ions, and 0.13% ruthenium ions in a water solution. The catalyst solution is maintained at 423--473 K. Wastes are introduced into contact with the solution, where their organic portion is oxidized to carbon dioxide and water. If the organic portion is chlorinated, hydrogen chloride will be produced as a product. The process is a viable alternative to incineration for the treatment of organic mixed wastes. Estimated costs for waste treatment using the process are from $2.50/kg to $25.00/kg, depending on the size of the unit and the amount of waste processed. Process units can be mobile for on-site treatment of wastes. Results from phase 1 and 2, design and engineering studies, are described.« less

A Comprehensive Review of Sensors and Instrumentation Methods in Devices for Musical Expression

PubMed Central

Medeiros, Carolina Brum; Wanderley, Marcelo M.

2014-01-01

Digital Musical Instruments (DMIs) are musical instruments typically composed of a control surface where user interaction is measured by sensors whose values are mapped to sound synthesis algorithms. These instruments have gained interest among skilled musicians and performers in the last decades leading to artistic practices including musical performance, interactive installations and dance. The creation of DMIs typically involves several areas, among them: arts, design and engineering. The balance between these areas is an essential task in DMI design so that the resulting instruments are aesthetically appealing, robust, and allow responsive, accurate and repeatable sensing. In this paper, we review the use of sensors in the DMI community as manifested in the proceedings of the International Conference on New Interfaces for Musical Expression (NIME 2009–2013). Focusing on the sensor technologies and signal conditioning techniques used by the NIME community. Although it has been claimed that specifications for artistic tools are harder than those for military applications, this study raises a paradox showing that in most of the cases, DMIs are based on a few basic sensors types and unsophisticated engineering solutions, not taking advantage of more advanced sensing, instrumentation and signal processing techniques that could dramatically improve their response. We aim to raise awareness of limitations of any engineering solution and to assert the benefits of advanced electronics instrumentation design in DMIs. For this, we propose the use of specialized sensors such as strain gages, advanced conditioning circuits and signal processing tools such as sensor fusion. We believe that careful electronic instrumentation design may lead to more responsive instruments. PMID:25068865

A comprehensive review of sensors and instrumentation methods in devices for musical expression.

PubMed

Medeiros, Carolina Brum; Wanderley, Marcelo M

2014-07-25

Digital Musical Instruments (DMIs) are musical instruments typically composed of a control surface where user interaction is measured by sensors whose values are mapped to sound synthesis algorithms. These instruments have gained interest among skilled musicians and performers in the last decades leading to artistic practices including musical performance, interactive installations and dance. The creation of DMIs typically involves several areas, among them: arts, design and engineering. The balance between these areas is an essential task in DMI design so that the resulting instruments are aesthetically appealing, robust, and allow responsive, accurate and repeatable sensing. In this paper, we review the use of sensors in the DMI community as manifested in the proceedings of the International Conference on New Interfaces for Musical Expression (NIME 2009-2013). Focusing on the sensor technologies and signal conditioning techniques used by the NIME community. Although it has been claimed that specifications for artistic tools are harder than those for military applications, this study raises a paradox showing that in most of the cases, DMIs are based on a few basic sensors types and unsophisticated engineering solutions, not taking advantage of more advanced sensing, instrumentation and signal processing techniques that could dramatically improve their response. We aim to raise awareness of limitations of any engineering solution and to assert the benefits of advanced electronics instrumentation design in DMIs. For this, we propose the use of specialized sensors such as strain gages, advanced conditioning circuits and signal processing tools such as sensor fusion. We believe that careful electronic instrumentation design may lead to more responsive instruments.

Quantifying resistances across nanoscale low- and high-angle interspherulite boundaries in solution-processed organic semiconductor thin films.

PubMed

Lee, Stephanie S; Mativetsky, Jeffrey M; Loth, Marsha A; Anthony, John E; Loo, Yueh-Lin

2012-11-27

The nanoscale boundaries formed when neighboring spherulites impinge in polycrystalline, solution-processed organic semiconductor thin films act as bottlenecks to charge transport, significantly reducing organic thin-film transistor mobility in devices comprising spherulitic thin films as the active layers. These interspherulite boundaries (ISBs) are structurally complex, with varying angles of molecular orientation mismatch along their lengths. We have successfully engineered exclusively low- and exclusively high-angle ISBs to elucidate how the angle of molecular orientation mismatch at ISBs affects their resistivities in triethylsilylethynyl anthradithiophene thin films. Conductive AFM and four-probe measurements reveal that current flow is unaffected by the presence of low-angle ISBs, whereas current flow is significantly disrupted across high-angle ISBs. In the latter case, we estimate the resistivity to be 22 MΩμm(2)/width of the ISB, only less than a quarter of the resistivity measured across low-angle grain boundaries in thermally evaporated sexithiophene thin films. This discrepancy in resistivities across ISBs in solution-processed organic semiconductor thin films and grain boundaries in thermally evaporated organic semiconductor thin films likely arises from inherent differences in the nature of film formation in the respective systems.

Double-Layer Gadolinium Zirconate/Yttria-Stabilized Zirconia Thermal Barrier Coatings Deposited by the Solution Precursor Plasma Spray Process

NASA Astrophysics Data System (ADS)

Jiang, Chen; Jordan, Eric H.; Harris, Alan B.; Gell, Maurice; Roth, Jeffrey

2015-08-01

Advanced thermal barrier coatings (TBCs) with lower thermal conductivity, increased resistance to calcium-magnesium-aluminosilicate (CMAS), and improved high-temperature capability, compared to traditional yttria-stabilized zirconia (YSZ) TBCs, are essential to higher efficiency in next generation gas turbine engines. Double-layer rare-earth zirconate/YSZ TBCs are a promising solution. From a processing perspective, solution precursor plasma spray (SPPS) process with its unique and beneficial microstructural features can be an effective approach to obtaining the double-layer microstructure. Previously durable low-thermal-conductivity YSZ TBCs with optimized layered porosity, called the inter-pass boundaries (IPBs) were produced using the SPPS process. In this study, an SPPS gadolinium zirconate (GZO) protective surface layer was successfully added. These SPPS double-layer TBCs not only retained good cyclic durability and low thermal conductivity, but also demonstrated favorable phase stability and increased surface temperature capabilities. The CMAS resistance was evaluated with both accumulative and single applications of simulated CMAS in isothermal furnaces. The double-layer YSZ/GZO exhibited dramatic improvement in the single application, but not in the continuous one. In addition, to explore their potential application in integrated gasification combined cycle environments, double-layer TBCs were tested under high-temperature humidity and encouraging performance was recorded.

Transfer of control system interface solutions from other domains to the thermal power industry.

PubMed

Bligård, L-O; Andersson, J; Osvalder, A-L

2012-01-01

In a thermal power plant the operators' roles are to control and monitor the process to achieve efficient and safe production. To achieve this, the human-machine interfaces have a central part. The interfaces need to be updated and upgraded together with the technical functionality to maintain optimal operation. One way of achieving relevant updates is to study other domains and see how they have solved similar issues in their design solutions. The purpose of this paper is to present how interface design solution ideas can be transferred from domains with operator control to thermal power plants. In the study 15 domains were compared using a model for categorisation of human-machine systems. The result from the domain comparison showed that nuclear power, refinery and ship engine control were most similar to thermal power control. From the findings a basic interface structure and three specific display solutions were proposed for thermal power control: process parameter overview, plant overview, and feed water view. The systematic comparison of the properties of a human-machine system allowed interface designers to find suitable objects, structures and navigation logics in a range of domains that could be transferred to the thermal power domain.

Review of Thawing Time Prediction Models Depending
on Process Conditions and Product Characteristics

PubMed Central

Kluza, Franciszek; Spiess, Walter E. L.; Kozłowicz, Katarzyna

2016-01-01

Summary Determining thawing times of frozen foods is a challenging problem as the thermophysical properties of the product change during thawing. A number of calculation models and solutions have been developed. The proposed solutions range from relatively simple analytical equations based on a number of assumptions to a group of empirical approaches that sometimes require complex calculations. In this paper analytical, empirical and graphical models are presented and critically reviewed. The conditions of solution, limitations and possible applications of the models are discussed. The graphical and semi--graphical models are derived from numerical methods. Using the numerical methods is not always possible as running calculations takes time, whereas the specialized software and equipment are not always cheap. For these reasons, the application of analytical-empirical models is more useful for engineering. It is demonstrated that there is no simple, accurate and feasible analytical method for thawing time prediction. Consequently, simplified methods are needed for thawing time estimation of agricultural and food products. The review reveals the need for further improvement of the existing solutions or development of new ones that will enable accurate determination of thawing time within a wide range of practical conditions of heat transfer during processing. PMID:27904387

An analytical solution for two-dimensional vacuum preloading combined with electro-osmosis consolidation using EKG electrodes

PubMed Central

Qiu, Chenchen; Li, Yande

2017-01-01

China is a country with vast territory, but economic development and population growth have reduced the usable land resources in recent years. Therefore, reclamation by pumping and filling is carried out in eastern coastal regions of China in order to meet the needs of urbanization. However, large areas of reclaimed land need rapid drainage consolidation treatment. Based on past researches on how to improve the treatment efficiency of soft clay using vacuum preloading combined with electro-osmosis, a two-dimensional drainage plane model was proposed according to the Terzaghi and Esrig consolidation theory. However, the analytical solution using two-dimensional plane model was never involved. Current analytical solutions can’t have a thorough theoretical analysis of practical engineering and give relevant guidance. Considering the smearing effect and the rectangle arrangement pattern, an analytical solution is derived to describe the behavior of pore-water and the consolidation process by using EKG (electro-kinetic geo synthetics) materials. The functions of EKG materials include drainage, electric conduction and corrosion resistance. Comparison with test results is carried out to verify the analytical solution. It is found that the measured value is larger than the applied vacuum degree because of the stacking effect of the vacuum preloading and electro-osmosis. The trends of the mean measured value and the mean analytical value processes are comparable. Therefore, the consolidation model can accurately assess the change in pore-water pressure and the consolidation process during vacuum preloading combined with electro-osmosis. PMID:28771496

Applying design principles to fusion reactor configurations for propulsion in space

NASA Technical Reports Server (NTRS)

Carpenter, Scott A.; Deveny, Marc E.; Schulze, Norman R.

1993-01-01

The application of fusion power to space propulsion requires rethinking the engineering-design solution to controlled-fusion energy. Whereas the unit cost of electricity (COE) drives the engineering-design solution for utility-based fusion reactor configurations; initial mass to low earth orbit (IMLEO), specific jet power (kW(thrust)/kg(engine)), and reusability drive the engineering-design solution for successful application of fusion power to space propulsion. We applied three design principles (DP's) to adapt and optimize three candidate-terrestrial-fusion-reactor configurations for propulsion in space. The three design principles are: provide maximum direct access to space for waste radiation, operate components as passive radiators to minimize cooling-system mass, and optimize the plasma fuel, fuel mix, and temperature for best specific jet power. The three candidate terrestrial fusion reactor configurations are: the thermal barrier tandem mirror (TBTM), field reversed mirror (FRM), and levitated dipole field (LDF). The resulting three candidate space fusion propulsion systems have their IMLEO minimized and their specific jet power and reusability maximized. We performed a preliminary rating of these configurations and concluded that the leading engineering-design solution to space fusion propulsion is a modified TBTM that we call the Mirror Fusion Propulsion System (MFPS).

Development of teaching modules for geology and engineering coursework using terrestrial LiDAR scanning systems

NASA Astrophysics Data System (ADS)

Yarbrough, L. D.; Katzenstein, K.

2012-12-01

Exposing students to active and local examples of physical geologic processes is beneficial to the learning process. Students typically respond with interest to examples that use state-of-the-art technologies to investigate local or regional phenomena. For lower cognitive level of learning (e.g. knowledge, comprehension, and application), the use of "close-to-home" examples ensures that students better understand concepts. By providing these examples, the students may already have a familiarity or can easily visit the location. Furthermore, these local and regional examples help students to offer quickly other examples of similar phenomena. Investigation of these examples using normal photographic techniques, as well as a more sophisticated 3-D Light Detection And Ranging (LiDAR) (AKA Terrestrial Laser Scanning or TLS) system, allows students to gain a better understanding of the scale and the mechanics of the geologic processes and hazards. The systems are used for research, teaching and outreach efforts and depending on departmental policies can be accessible to students are various learning levels. TLS systems can yield scans at sub-centimeter resolution and contain surface reflectance of targets. These systems can serve a number of learning goals that are essential for training geoscientists and engineers. While querying the data to answer geotechnical or geomorphologic related questions, students will develop skills using large, spatial databases. The upper cognitive level of learning (e.g. analysis, synthesis, and evaluation) is also promoted by using a subset of the data and correlating the physical geologic process of stream bank erosion and rock slope failures with mathematical and computer models using the scanned data. Students use the examples and laboratory exercises to help build their engineering judgment skills with Earth materials. The students learn not only applications of math and engineering science but also the economic and social implication of designed engineering solutions. These course learning modules were developed for traditional geological engineering courses delivered on campus, for more intensive field work courses and online-based asynchronous course delivery.

Smart assembly of polymer fibers: lessons from major ampullate spider silk

NASA Astrophysics Data System (ADS)

Viney, Christopher

1996-02-01

Studies of major ampullate silk (MAS), especially the secretions and fibers produced by the spider Nephila clavipes (golden orb weaver), have yielded several results of potential value to the materials scientist/engineer. There are lessons to be learned about synthesis, processing and microstructural design of high-tensile polymer fibers. The 'smart' aspect of silk production in nature concerns the ability of the spider to rapidly process a concentrated, viscous aqueous solution of silk protein (stored in the gland) into water-insoluble fiber on demand. This process centers on the assembly of a shear-sensitive supramolecular liquid crystalline phase by aggregation of the solubilized globular protein molecules.

Processing Of Neem And Jatropha Methyl Esters -Alternative Fuels From Vegetable Oil

NASA Astrophysics Data System (ADS)

Ramasubramanian, S.; Manavalan, S.; Gnanavel, C.; Balakrishnan, G.

2017-03-01

Biodiesel is an alternative fuel for diesel engine. The methyl esters of vegetable oils, known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engine. This paper deals with the manufacturing process of Biodiesel from jatropha and neem oil. Biodiesel was prepared from neem oil and jatropha oil, the transestrified having kinematic viscosity of 3 & 2.6 centistokes, methanol ratio is 6:1 & 5.1respectively. The secondary solution is preheated at 65 C & 60 C and reaction temperature is maintained at 60C & 55 C and reaction time is 60 minutes approximately with NaOH catalyst and low viscosity oil is allowed to settle 24 hours. The average yield of neem and jatropha methyl esters was about 85%. These methyl esters shows excellent alternative under optimum condition for fossil fuels.

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

NASA Technical Reports Server (NTRS)

Hickox, C. E.

1975-01-01

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

Engineering microbes for isoprene production.

PubMed

Ye, Lidan; Lv, Xiaomei; Yu, Hongwei

2016-11-01

Isoprene is facing a growing global market due to its wide industrial applications. Current industrial production of isoprene is almost entirely petroleum-based, which is influenced by the shrinking C5 supply, while the natural emission of isoprene is predominantly contributed by plants. To bridge the need gap, a highly efficient fermentation-based process for isoprene production might be a suitable and sustainable solution, and extensive research works have been performed to achieve this goal. Here we review the accomplishments in this field by summarizing the history and prospects of microbial isoprene production. The natural producers and biosynthesis pathways of isoprene, the key enzyme isoprene synthase and the metabolic engineering strategies adopted for developing isoprene-producing microorganisms are introduced. In particular, strategies employed for achieving engineered strains with improved performance indices are discussed based on the published papers and patents. The perspectives on further performance improvements and potential future strategies are presented as well. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Accuracy Quantification of the Loci-CHEM Code for Chamber Wall Heat Transfer in a GO2/GH2 Single Element Injector Model Problem

NASA Technical Reports Server (NTRS)

West, Jeff; Westra, Doug; Lin, Jeff; Tucker, Kevin

2006-01-01

A robust rocket engine combustor design and development process must include tools which can accurately predict the multi-dimensional thermal environments imposed on solid surfaces by the hot combustion products. Currently, empirical methods used in the design process are typically one dimensional and do not adequately account for the heat flux rise rate in the near-injector region of the chamber. Computational Fluid Dynamics holds promise to meet the design tool requirement, but requires accuracy quantification, or validation, before it can be confidently applied in the design process. This effort presents the beginning of such a validation process for the Loci-CHEM CFD code. The model problem examined here is a gaseous oxygen (GO2)/gaseous hydrogen (GH2) shear coaxial single element injector operating at a chamber pressure of 5.42 MPa. The GO2/GH2 propellant combination in this geometry represents one the simplest rocket model problems and is thus foundational to subsequent validation efforts for more complex injectors. Multiple steady state solutions have been produced with Loci-CHEM employing different hybrid grids and two-equation turbulence models. Iterative convergence for each solution is demonstrated via mass conservation, flow variable monitoring at discrete flow field locations as a function of solution iteration and overall residual performance. A baseline hybrid was used and then locally refined to demonstrate grid convergence. Solutions were obtained with three variations of the k-omega turbulence model.

Accuracy Quantification of the Loci-CHEM Code for Chamber Wall Heat Fluxes in a G02/GH2 Single Element Injector Model Problem

NASA Technical Reports Server (NTRS)

West, Jeff; Westra, Doug; Lin, Jeff; Tucker, Kevin

2006-01-01

A robust rocket engine combustor design and development process must include tools which can accurately predict the multi-dimensional thermal environments imposed on solid surfaces by the hot combustion products. Currently, empirical methods used in the design process are typically one dimensional and do not adequately account for the heat flux rise rate in the near-injector region of the chamber. Computational Fluid Dynamics holds promise to meet the design tool requirement, but requires accuracy quantification, or validation, before it can be confidently applied in the design process. This effort presents the beginning of such a validation process for the Loci- CHEM CPD code. The model problem examined here is a gaseous oxygen (GO2)/gaseous hydrogen (GH2) shear coaxial single element injector operating at a chamber pressure of 5.42 MPa. The GO2/GH2 propellant combination in this geometry represents one the simplest rocket model problems and is thus foundational to subsequent validation efforts for more complex injectors. Multiple steady state solutions have been produced with Loci-CHEM employing different hybrid grids and two-equation turbulence models. Iterative convergence for each solution is demonstrated via mass conservation, flow variable monitoring at discrete flow field locations as a function of solution iteration and overall residual performance. A baseline hybrid grid was used and then locally refined to demonstrate grid convergence. Solutions were also obtained with three variations of the k-omega turbulence model.

A Comprehensive Solution of the Problems of Ensuring the Strength of Gas Turbine Engine Compressor at the Design Stage

NASA Astrophysics Data System (ADS)

Vedeneev, V. V.; Kolotnikov, M. E.; Mossakovskii, P. A.; Kostyreva, L. A.; Abdukhakimov, F. A.; Makarov, P. V.; Pyhalov, A. A.; Dudaev, M. A.

2018-01-01

In this paper we present a complex numerical workflow for analysis of blade flutter and high-amplitude resonant oscillations, impenetrability of casing if the blade is broken off, and the rotor reaction to the blade detachment and following misbalance, with the assessment of a safe flight possibility at the auto-rotation regime. All the methods used are carefully verified by numerical convergence study and correlations with experiments. The use of the workflow developed significantly improves the efficiency of the design process of modern jet engine compressors. It ensures a significant reduction of time and cost of the compressor design with the required level of strength and durability.

A nonchromatographic process for purification of secretory immunoglobulins from caprine whey.

PubMed

Matlschweiger, Alexander; Himmler, Gottfried; Linhart, Clemens; Harasek, Michael; Hahn, Rainer

2017-05-01

Secretory immunoglobulins are an important antibody class being primarily responsible for immunoprotection of mucosal surfaces. A simple, non-chromatographic purification process for secretory immunoglobulins from caprine whey was developed. In the first process step whey was concentrated 30-40-fold on a 500 kDa membrane, thereby increasing the purity from 3% to 15%. The second step consisted of a fractionated PEG precipitation, in which high molecular weight impurities were removed first and in the second stage the secretory immunoglobulins were precipitated, leaving a majority of the low molecular weight proteins in solution. The re-dissolved secretory immunoglobulin fraction had a purity of 43% which could then be increased to 72% by diafiltration at a volume exchange factor of 10. Further increase of purity was only possible at the expense of very high buffer consumption. If diafiltration was performed directly after ultrafiltration, followed by precipitation, the yield was higher but purity was only 54%. Overall, filtration performance was characterized by high concentration polarization, therefore process conditions were set to low trans-membrane pressure and moderate protein concentration. As such purity and to a lesser extent throughput were the major objectives rather than yield, since whey, as a by-product of the dairy industry, is a cheap raw material of almost unlimited supply. Ultra-/diafiltration performance was described well by correlations using dimensionless numbers. Compared with a theoretical model (Graetz/Leveque solution) the flux was slightly overestimated. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:642-653, 2017. © 2017 American Institute of Chemical Engineers.

Explicit analytical tuning rules for digital PID controllers via the magnitude optimum criterion.

PubMed

Papadopoulos, Konstantinos G; Yadav, Praveen K; Margaris, Nikolaos I

2017-09-01

Analytical tuning rules for digital PID type-I controllers are presented regardless of the process complexity. This explicit solution allows control engineers 1) to make an accurate examination of the effect of the controller's sampling time to the control loop's performance both in the time and frequency domain 2) to decide when the control has to be I, PI and when the derivative, D, term has to be added or omitted 3) apply this control action to a series of stable benchmark processes regardless of their complexity. The former advantages are considered critical in industry applications, since 1) most of the times the choice of the digital controller's sampling time is based on heuristics and past criteria, 2) there is little a-priori knowledge of the controlled process making the choice of the type of the controller a trial and error exercise 3) model parameters change often depending on the control loop's operating point making in this way, the problem of retuning the controller's parameter a much challenging issue. Basis of the proposed control law is the principle of the PID tuning via the Magnitude Optimum criterion. The final control law involves the controller's sampling time T s within the explicit solution of the controller's parameters. Finally, the potential of the proposed method is justified by comparing its performance with the conventional PID tuning when controlling the same process. Further investigation regarding the choice of the controller's sampling time T s is also presented and useful conclusions for control engineers are derived. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Closed-form solution of the Ogden-Hill's compressible hyperelastic model for ramp loading

NASA Astrophysics Data System (ADS)

Berezvai, Szabolcs; Kossa, Attila

2017-05-01

This article deals with the visco-hyperelastic modelling approach for compressible polymer foam materials. Polymer foams can exhibit large elastic strains and displacements in case of volumetric compression. In addition, they often show significant rate-dependent properties. This material behaviour can be accurately modelled using the visco-hyperelastic approach, in which the large strain viscoelastic description is combined with the rate-independent hyperelastic material model. In case of polymer foams, the most widely used compressible hyperelastic material model, the so-called Ogden-Hill's model, was applied, which is implemented in the commercial finite element (FE) software Abaqus. The visco-hyperelastic model is defined in hereditary integral form, therefore, obtaining a closed-form solution for the stress is not a trivial task. However, the parameter-fitting procedure could be much faster and accurate if closed-form solution exists. In this contribution, exact stress solutions are derived in case of uniaxial, biaxial and volumetric compression loading cases using ramp-loading history. The analytical stress solutions are compared with the stress results in Abaqus using FE analysis. In order to highlight the benefits of the analytical closed-form solution during the parameter-fitting process experimental work has been carried out on a particular open-cell memory foam material. The results of the material identification process shows significant accuracy improvement in the fitting procedure by applying the derived analytical solutions compared to the so-called separated approach applied in the engineering practice.

Rurality as an Asset for Inclusive Teaching in Chemical Engineering

ERIC Educational Resources Information Center

Gomez, Jamie; Svihla, Vanessa

2018-01-01

We developed and tested a pedagogical strategy--asset-based design challenges--to enhance diversity in early chemical engineering coursework. Using qualitative methods, we found first-year students justified high-cost solutions with ethical arguments; teams that included rural expertise argued instead for economically-viable solutions. In the…

Transient Seepage Analyses in Levee Engineering Practice

DTIC Science & Technology

2016-07-01

and contractors in conventional engineering practice has outpaced the development of guidance documents and design recommendations. The major...ERDC TR-16-8 99 B.5 Final solution The final solution is obtained by first solving for ht from Equation B.5 as follows: t t tssˆh h h  (B

Systemic solutions for multi-benefit water and environmental management.

PubMed

Everard, Mark; McInnes, Robert

2013-09-01

The environmental and financial costs of inputs to, and unintended consequences arising from narrow consideration of outputs from, water and environmental management technologies highlight the need for low-input solutions that optimise outcomes across multiple ecosystem services. Case studies examining the inputs and outputs associated with several ecosystem-based water and environmental management technologies reveal a range from those that differ little from conventional electro-mechanical engineering techniques through methods, such as integrated constructed wetlands (ICWs), designed explicitly as low-input systems optimising ecosystem service outcomes. All techniques present opportunities for further optimisation of outputs, and hence for greater cumulative public value. We define 'systemic solutions' as "…low-input technologies using natural processes to optimise benefits across the spectrum of ecosystem services and their beneficiaries". They contribute to sustainable development by averting unintended negative impacts and optimising benefits to all ecosystem service beneficiaries, increasing net economic value. Legacy legislation addressing issues in a fragmented way, associated 'ring-fenced' budgets and established management assumptions represent obstacles to implementing 'systemic solutions'. However, flexible implementation of legacy regulations recognising their primary purpose, rather than slavish adherence to detailed sub-clauses, may achieve greater overall public benefit through optimisation of outcomes across ecosystem services. Systemic solutions are not a panacea if applied merely as 'downstream' fixes, but are part of, and a means to accelerate, broader culture change towards more sustainable practice. This necessarily entails connecting a wider network of interests in the formulation and design of mutually-beneficial systemic solutions, including for example spatial planners, engineers, regulators, managers, farming and other businesses, and researchers working on ways to quantify and optimise delivery of ecosystem services. Copyright © 2013 Elsevier B.V. All rights reserved.

Environmental Testing of the NEXT PM1R Ion Engine

NASA Technical Reports Server (NTRS)

Snyder, John S.; Anderson, John R.; VanNoord, Jonathan L.; Soulas, George C.

2007-01-01

The NEXT propulsion system is an advanced ion propulsion system presently under development that is oriented towards robotic exploration of the solar system using solar electric power. The subsystem includes an ion engine, power processing unit, feed system components, and thruster gimbal. The Prototype Model engine PM1 was subjected to qualification-level environmental testing in 2006 to demonstrate compatibility with environments representative of anticipated mission requirements. Although the testing was largely successful, several issues were identified including the fragmentation of potting cement on the discharge and neutralizer cathode heater terminations during vibration which led to abbreviated thermal testing, and generation of particulate contamination from manufacturing processes and engine materials. The engine was reworked to address most of these findings, renamed PM1R, and the environmental test sequence was repeated. Thruster functional testing was performed before and after the vibration and thermal-vacuum tests. Random vibration testing, conducted with the thruster mated to the breadboard gimbal, was executed at 10.0 Grms for 2 min in each of three axes. Thermal-vacuum testing included three thermal cycles from 120 to 215 C with hot engine re-starts. Thruster performance was nominal throughout the test program, with minor variations in a few engine operating parameters likely caused by facility effects. There were no significant changes in engine performance as characterized by engine operating parameters, ion optics performance measurements, and beam current density measurements, indicating no significant changes to the hardware as a result of the environmental testing. The NEXT PM1R engine and the breadboard gimbal were found to be well-designed against environmental requirements based on the results reported herein. The redesigned cathode heater terminations successfully survived the vibration environments. Based on the results of this test program and confidence in the engineering solutions available for the remaining findings of the first test program, specifically the particulate contamination, the hardware environmental qualification program can proceed with confidence

Python Winding Itself Around Datacubes: How to Access Massive Multi-Dimensional Arrays in a Pythonic Way

NASA Astrophysics Data System (ADS)

Merticariu, Vlad; Misev, Dimitar; Baumann, Peter

2017-04-01

While python has developed into the lingua franca in Data Science there is often a paradigm break when accessing specialized tools. In particular for one of the core data categories in science and engineering, massive multi-dimensional arrays, out-of-memory solutions typically employ their own, different models. We discuss this situation on the example of the scalable open-source array engine, rasdaman ("raster data manager") which offers access to and processing of Petascale multi-dimensional arrays through an SQL-style array query language, rasql. Such queries are executed in the server on a storage engine utilizing adaptive array partitioning and based on a processing engine implementing a "tile streaming" paradigm to allow processing of arrays massively larger than server RAM. The rasdaman QL has acted as blueprint for forthcoming ISO Array SQL and the Open Geospatial Consortium (OGC) geo analytics language, Web Coverage Processing Service, adopted in 2008. Not surprisingly, rasdaman is OGC and INSPIRE Reference Implementation for their "Big Earth Data" standards suite. Recently, rasdaman has been augmented with a python interface which allows to transparently interact with the database (credits go to Siddharth Shukla's Master Thesis at Jacobs University). Programmers do not need to know the rasdaman query language, as the operators are silently transformed, through lazy evaluation, into queries. Arrays delivered are likewise automatically transformed into their python representation. In the talk, the rasdaman concept will be illustrated with the help of large-scale real-life examples of operational satellite image and weather data services, and sample python code.

Human umbilical cord derived matrix: A scaffold suitable for tissue engineering application.

PubMed

Dan, Pan; Velot, Émilie; Mesure, Benjamin; Groshenry, Guillaume; Bacharouche, Jalal; Decot, Véronique; Menu, Patrick

2017-01-01

Human tissue derived natural extracellular matrix (ECM) has great potential in tissue engineering. We sought to isolate extracellular matrix derived from human umbilical cord and test its potential in tissue engineering. An enzymatic method was applied to isolate and solubilized complete human umbilical cord derived matrix (hUCM). The obtained solution was analyzed for growth factors, collagen and residual DNA contents, then used to coat 2D and 3D surfaces for cell culture application. The hUCM was successfully isolated with trypsin digestion to acquire a solution containing various growth factors and collagen but no residual DNA. This hUCM solution can form a coating on 2D and 3D substrates suitable cell culture. We developed a new matrix derived from human source that can be further used in tissue engineering.

Using pattern based layout comparison for a quick analysis of design changes

NASA Astrophysics Data System (ADS)

Huang, Lucas; Yang, Legender; Kan, Huan; Zou, Elain; Wan, Qijian; Du, Chunshan; Hu, Xinyi; Liu, Zhengfang

2018-03-01

A design usually goes through several versions until achieving a most successful one. These changes between versions are not a complete substitution but a continual improvement, either fixing the known issues of its prior versions (engineering change order) or a more optimized design substitution of a portion of the design. On the manufacturing side, process engineers care more about the design pattern changes because any new pattern occurrence may be a killer of the yield. An effective and efficient way to narrow down the diagnosis scope appeals to the engineers. What is the best approach of comparing two layouts? A direct overlay of two layouts may not always work as even though most of the design instances will be kept in the layout from version to version, the actual placements may be different. An alternative way, pattern based layout comparison, comes to play. By expanding this application, it makes it possible to transfer the learning in one cycle to another and accelerate the process of failure analysis. This paper presents a solution to compare two layouts by using Calibre DRC and Pattern Matching. The key step in this flow is layout decomposition. In theory, with a fixed pattern size, a layout can always be decomposed into limited number of patterns by moving the pattern center around the layout, the number is limited but may be huge if the layout is not processed smartly! A mathematical answer is not what we are looking for but an engineering solution is more desired. Layouts must be decomposed into patterns with physical meaning in a smart way. When a layout is decomposed and patterns are classified, a pattern library with unique patterns inside is created for that layout. After individual pattern libraries for each layout are created, run pattern comparison utility provided by Calibre Pattern Matching to compare the pattern libraries, unique patterns will come out for each layout. This paper illustrates this flow in details and demonstrates the advantage of combining Calibre DRC and Calibre Pattern Matching.

Facilitating the learning process in design-based learning practices: an investigation of teachers' actions in supervising students

NASA Astrophysics Data System (ADS)

Gómez Puente, S. M.; van Eijck, M.; Jochems, W.

2013-11-01

Background: In research on design-based learning (DBL), inadequate attention is paid to the role the teacher plays in supervising students in gathering and applying knowledge to design artifacts, systems, and innovative solutions in higher education. Purpose: In this study, we examine whether teacher actions we previously identified in the DBL literature as important in facilitating learning processes and student supervision are present in current DBL engineering practices. Sample: The sample (N=16) consisted of teachers and supervisors in two engineering study programs at a university of technology: mechanical and electrical engineering. We selected randomly teachers from freshman and second-year bachelor DBL projects responsible for student supervision and assessment. Design and method: Interviews with teachers, and interviews and observations of supervisors were used to examine how supervision and facilitation actions are applied according to the DBL framework. Results: Major findings indicate that formulating questions is the most common practice seen in facilitating learning in open-ended engineering design environments. Furthermore, other DBL actions we expected to see based upon the literature were seldom observed in the coaching practices within these two programs. Conclusions: Professionalization of teachers in supervising students need to include methods to scaffold learning by supporting students in reflecting and in providing formative feedback.

Model-based engineering for laser weapons systems

NASA Astrophysics Data System (ADS)

Panthaki, Malcolm; Coy, Steve

2011-10-01

The Comet Performance Engineering Workspace is an environment that enables integrated, multidisciplinary modeling and design/simulation process automation. One of the many multi-disciplinary applications of the Comet Workspace is for the integrated Structural, Thermal, Optical Performance (STOP) analysis of complex, multi-disciplinary space systems containing Electro-Optical (EO) sensors such as those which are designed and developed by and for NASA and the Department of Defense. The CometTM software is currently able to integrate performance simulation data and processes from a wide range of 3-D CAD and analysis software programs including CODE VTM from Optical Research Associates and SigFitTM from Sigmadyne Inc. which are used to simulate the optics performance of EO sensor systems in space-borne applications. Over the past year, Comet Solutions has been working with MZA Associates of Albuquerque, NM, under a contract with the Air Force Research Laboratories. This funded effort is a "risk reduction effort", to help determine whether the combination of Comet and WaveTrainTM, a wave optics systems engineering analysis environment developed and maintained by MZA Associates and used by the Air Force Research Laboratory, will result in an effective Model-Based Engineering (MBE) environment for the analysis and design of laser weapons systems. This paper will review the results of this effort and future steps.

Probabilistic Finite Element Analysis & Design Optimization for Structural Designs

NASA Astrophysics Data System (ADS)

Deivanayagam, Arumugam

This study focuses on implementing probabilistic nature of material properties (Kevlar® 49) to the existing deterministic finite element analysis (FEA) of fabric based engine containment system through Monte Carlo simulations (MCS) and implementation of probabilistic analysis in engineering designs through Reliability Based Design Optimization (RBDO). First, the emphasis is on experimental data analysis focusing on probabilistic distribution models which characterize the randomness associated with the experimental data. The material properties of Kevlar® 49 are modeled using experimental data analysis and implemented along with an existing spiral modeling scheme (SMS) and user defined constitutive model (UMAT) for fabric based engine containment simulations in LS-DYNA. MCS of the model are performed to observe the failure pattern and exit velocities of the models. Then the solutions are compared with NASA experimental tests and deterministic results. MCS with probabilistic material data give a good prospective on results rather than a single deterministic simulation results. The next part of research is to implement the probabilistic material properties in engineering designs. The main aim of structural design is to obtain optimal solutions. In any case, in a deterministic optimization problem even though the structures are cost effective, it becomes highly unreliable if the uncertainty that may be associated with the system (material properties, loading etc.) is not represented or considered in the solution process. Reliable and optimal solution can be obtained by performing reliability optimization along with the deterministic optimization, which is RBDO. In RBDO problem formulation, in addition to structural performance constraints, reliability constraints are also considered. This part of research starts with introduction to reliability analysis such as first order reliability analysis, second order reliability analysis followed by simulation technique that are performed to obtain probability of failure and reliability of structures. Next, decoupled RBDO procedure is proposed with a new reliability analysis formulation with sensitivity analysis, which is performed to remove the highly reliable constraints in the RBDO, thereby reducing the computational time and function evaluations. Followed by implementation of the reliability analysis concepts and RBDO in finite element 2D truss problems and a planar beam problem are presented and discussed.

Investigating the Impact of Using a CAD Simulation Tool on Students' Learning of Design Thinking

NASA Astrophysics Data System (ADS)

Taleyarkhan, Manaz; Dasgupta, Chandan; Garcia, John Mendoza; Magana, Alejandra J.

2018-02-01

Engineering design thinking is hard to teach and still harder to learn by novices primarily due to the undetermined nature of engineering problems that often results in multiple solutions. In this paper, we investigate the effect of teaching engineering design thinking to freshmen students by using a computer-aided Design (CAD) simulation software. We present a framework for characterizing different levels of engineering design thinking displayed by students who interacted with the CAD simulation software in the context of a collaborative assignment. This framework describes the presence of four levels of engineering design thinking—beginning designer, adept beginning designer, informed designer, adept informed designer. We present the characteristics associated with each of these four levels as they pertain to four engineering design strategies that students pursued in this study—understanding the design challenge, building knowledge, weighing options and making tradeoffs, and reflecting on the process. Students demonstrated significant improvements in two strategies—understanding the design challenge and building knowledge. We discuss the affordances of the CAD simulation tool along with the learning environment that potentially helped students move towards Adept informed designers while pursuing these design strategies.

Multifunctional Collaborative Modeling and Analysis Methods in Engineering Science

NASA Technical Reports Server (NTRS)

Ransom, Jonathan B.; Broduer, Steve (Technical Monitor)

2001-01-01

Engineers are challenged to produce better designs in less time and for less cost. Hence, to investigate novel and revolutionary design concepts, accurate, high-fidelity results must be assimilated rapidly into the design, analysis, and simulation process. This assimilation should consider diverse mathematical modeling and multi-discipline interactions necessitated by concepts exploiting advanced materials and structures. Integrated high-fidelity methods with diverse engineering applications provide the enabling technologies to assimilate these high-fidelity, multi-disciplinary results rapidly at an early stage in the design. These integrated methods must be multifunctional, collaborative, and applicable to the general field of engineering science and mechanics. Multifunctional methodologies and analysis procedures are formulated for interfacing diverse subdomain idealizations including multi-fidelity modeling methods and multi-discipline analysis methods. These methods, based on the method of weighted residuals, ensure accurate compatibility of primary and secondary variables across the subdomain interfaces. Methods are developed using diverse mathematical modeling (i.e., finite difference and finite element methods) and multi-fidelity modeling among the subdomains. Several benchmark scalar-field and vector-field problems in engineering science are presented with extensions to multidisciplinary problems. Results for all problems presented are in overall good agreement with the exact analytical solution or the reference numerical solution. Based on the results, the integrated modeling approach using the finite element method for multi-fidelity discretization among the subdomains is identified as most robust. The multiple-method approach is advantageous when interfacing diverse disciplines in which each of the method's strengths are utilized. The multifunctional methodology presented provides an effective mechanism by which domains with diverse idealizations are interfaced. This capability rapidly provides the high-fidelity results needed in the early design phase. Moreover, the capability is applicable to the general field of engineering science and mechanics. Hence, it provides a collaborative capability that accounts for interactions among engineering analysis methods.

Advanced control concepts. [trim solution for space shuttle

NASA Technical Reports Server (NTRS)

Hutton, M. F.; Friedland, B.

1973-01-01

The selection of a trim solution that provides the space shuttle with the highest level of performance and dynamic control in the presense of wind disturbances and bias torques due to misalignment of rocket engines is described. It was determined that engine gimballing is insufficient to provide control to trim the vehicle for headwind and sidewind disturbances, and that it is necessary to use aerodynamic surfaces in conjunction with engine gimballing to achieve trim. The algebraic equations for computing the trim solution were derived from the differential equations describing the motion of the vehicle by substituting the desired trim conditions. The general problem of showing how the trim equations are derived from the equations of motion and the mathematical forms of the performance criterion is discussed in detail, along with the general equations for studying the dynamic response of the trim solution.

Achieving High Performance Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Yang, Yang

2015-03-01

Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

Enterprise resource planning (ERP) implementation using the value engineering methodology and Six Sigma tools

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.

Engineering design skills coverage in K-12 engineering program curriculum materials in the USA

NASA Astrophysics Data System (ADS)

Chabalengula, Vivien M.; Mumba, Frackson

2017-11-01

The current K-12 Science Education framework and Next Generation Science Standards (NGSS) in the United States emphasise the integration of engineering design in science instruction to promote scientific literacy and engineering design skills among students. As such, many engineering education programmes have developed curriculum materials that are being used in K-12 settings. However, little is known about the nature and extent to which engineering design skills outlined in NGSS are addressed in these K-12 engineering education programme curriculum materials. We analysed nine K-12 engineering education programmes for the nature and extent of engineering design skills coverage. Results show that developing possible solutions and actual designing of prototypes were the highly covered engineering design skills; specification of clear goals, criteria, and constraints received medium coverage; defining and identifying an engineering problem; optimising the design solution; and demonstrating how a prototype works, and making iterations to improve designs were lowly covered. These trends were similar across grade levels and across discipline-specific curriculum materials. These results have implications on engineering design-integrated science teaching and learning in K-12 settings.

Stable Beginnings in Engineering Design

ERIC Educational Resources Information Center

McCormick, Mary E.; Hammer, David

2016-01-01

Novel Engineering activities are premised on the integration of engineering and literacy: students identify and engineer solutions to problems that arise for fictional characters in stories they read for class. There are advantages to this integration, for both engineering and literacy goals of instruction: the stories provide ''clients'' to…

Building Efficiency Technologies by Tomorrow’s Engineers and Researchers (BETTER) Capstone. Final Technical Report

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

Yee, Shannon

BETTER Capstone supported 29 student project teams consisting of 155 students over two years in developing transformative building energy efficiency technologies through a capstone design experience. Capstone is the culmination of an undergraduate student’s engineering education. Interdisciplinary teams of students spent a semester designing and prototyping a technological solution for a variety building energy efficiency problems. During this experience students utilized the full design process, including the manufacturing and testing of a prototype solution, as well as publically demonstrating the solution at the Capstone Design Expo. As part of this project, students explored modern manufacturing techniques and gained hands-on experiencemore » with these techniques to produce their prototype technologies. This research added to the understanding of the challenges within building technology education and engagement with industry. One goal of the project was to help break the chicken-and-egg problem with getting students to engage more deeply with the building technology industry. It was learned however that this industry is less interested in trying innovative new concept but rather interested in hiring graduates for existing conventional building efforts. While none of the projects yielded commercial success, much individual student growth and learning was accomplished, which is a long-term benefit to the public at large.« less

An analysis code for the Rapid Engineering Estimation of Momentum and Energy Losses (REMEL)

NASA Technical Reports Server (NTRS)

Dechant, Lawrence J.

1994-01-01

Nonideal behavior has traditionally been modeled by defining efficiency (a comparison between actual and isentropic processes), and subsequent specification by empirical or heuristic methods. With the increasing complexity of aeropropulsion system designs, the reliability of these more traditional methods is uncertain. Computational fluid dynamics (CFD) and experimental methods can provide this information but are expensive in terms of human resources, cost, and time. This report discusses an alternative to empirical and CFD methods by applying classical analytical techniques and a simplified flow model to provide rapid engineering estimates of these losses based on steady, quasi-one-dimensional governing equations including viscous and heat transfer terms (estimated by Reynold's analogy). A preliminary verification of REMEL has been compared with full Navier-Stokes (FNS) and CFD boundary layer computations for several high-speed inlet and forebody designs. Current methods compare quite well with more complex method results and solutions compare very well with simple degenerate and asymptotic results such as Fanno flow, isentropic variable area flow, and a newly developed, combined variable area duct with friction flow solution. These solution comparisons may offer an alternative to transitional and CFD-intense methods for the rapid estimation of viscous and heat transfer losses in aeropropulsion systems.

Implementation of object-oriented programming in study of electrical race car

NASA Astrophysics Data System (ADS)

Nowak, M.; Baier, M.

2016-08-01

The paper covers issue of conducting advanced research of electrical race car participating in international competition called Sileverline Corporate Challenge. Process of designing race cars in Silesian Greenpower team is aided by a professional engine test stand built particularly in purpose of this research. Phase of testing and simulation is an important part of the implementation of new technologies. Properly developed solutions and test procedures are able to significantly shorten development time and reduce design costs. Testing process must be controlled by a modular and flexible application, easy to modify and ensuring safety. This paper describes the concept of object-oriented programming in LabVIEW and exemplary architecture of object-oriented control application designed to control engine test stand of the electrical race car. Eventually, the task of application will be to steer the electromagnetic brake and the engine load torque to perform according to data from the actual race track. During the designing process of the car, minimizing energy losses and maximizing powertrain efficiency are the main aspects taken into consideration. One of the crucial issues to accomplish these goals is to maintain optimal performance of the motor by applying effective cooling. The paper covers the research verifying the effectiveness of the cooling system.

Enhancement of Micropollutant Degradation at the Outlet of Small Wastewater Treatment Plants

PubMed Central

Rossi, Luca; Queloz, Pierre; Brovelli, Alessandro; Margot, Jonas; Barry, D. A.

2013-01-01

The aim of this work was to evaluate low-cost and easy-to-operate engineering solutions that can be added as a polishing step to small wastewater treatment plants to reduce the micropollutant load to water bodies. The proposed design combines a sand filter/constructed wetland with additional and more advanced treatment technologies (UV degradation, enhanced adsorption to the solid phase, e.g., an engineered substrate) to increase the elimination of recalcitrant compounds. The removal of five micropollutants with different physico-chemical characteristics (three pharmaceuticals: diclofenac, carbamazepine, sulfamethoxazole, one pesticide: mecoprop, and one corrosion inhibitor: benzotriazole) was studied to evaluate the feasibility of the proposed system. Separate batch experiments were conducted to assess the removal efficiency of UV degradation and adsorption. The efficiency of each individual process was substance-specific. No process was effective on all the compounds tested, although elimination rates over 80% using light expanded clay aggregate (an engineered material) were observed. A laboratory-scale flow-through setup was used to evaluate interactions when removal processes were combined. Four of the studied compounds were partially eliminated, with poor removal of the fifth (benzotriazole). The energy requirements for a field-scale installation were estimated to be the same order of magnitude as those of ozonation and powdered activated carbon treatments. PMID:23484055

Electrospun Nanocomposite Materials, A Novel Synergy of Polyurethane and Bovine Derived Hydroxyapatite

NASA Astrophysics Data System (ADS)

Bozkurt, Y.; Sahin, A.; Sunulu, A.; Aydogdu, M. O.; Altun, E.; Oktar, F. N.; Ekren, N.; Gunduz, O.

2017-04-01

Polyurethane (PU) is a synthetic polymer that is used for construction of scaffold in tissue engineering applications in order to obtain desirable mechanical, physical and chemical properties like elasticity and durability. Bovine derived hydroxyapatite (BHAp) is a ceramic based natural polymer that is used as the most preferred implant material in orthopedics and dentistry due to their chemically and biologically similarity to the mineral phase found in the human bone structure. PU and bovine derived hydroxyapatite (BHAp) solutions with different concentrations were prepared with dissolving polyurethane and BHAp in Dimethylformamide (DMF) and Tetrahydrofuran (THF) solutions. Blended PU-BHAp solutions in different concentrations were used for electrospinning technique to create nanofiber scaffolds and new biocomposite material together. SEM, FTIR and physical analysis such as viscosity, electrical conductivity, density measurement and tensile strength measurement tests were carried out after production process.

An investigation of spectral characteristics of water-glucose solutions

NASA Astrophysics Data System (ADS)

Lastovskaia, Elena A.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Korotaev, Valery V.

2016-04-01

One of the problems of modern medical device engineering is the development of an instrument for non-invasive monitoring of glucose levels in the blood. The urgency of this task is ensured by the following facts: the increase in the incidence of diabetes, the need for regular monitoring of blood sugar, and pain of modern methods of glycemia measurement. The problem can be solved with the help of a spectrophotometric method. This report is devoted to the investigation of spectral characteristics of glucose solution with various molar concentrations. The authors proposed the methodology of experimental research and data processing algorithm. The results of the experimental studies confirmed potential opportunity of blood sugar control by spectrophotometric method. Further research is expected to continue by the way of complication of the composition of the object from an aqueous solution of glucose to biological object.

High Performance of Perovskite Solar Cells via Catalytic Treatment in Two-Step Process: The Case of Solvent Engineering.

PubMed

Li, Wenzhe; Fan, Jiandong; Li, Jiangwei; Niu, Guangda; Mai, Yaohua; Wang, Liduo

2016-11-09

Currently, the potential mechanism of the solvent-assisted crystallization for mixed cations perovskite thin film (FA x MA 1-x PbI 3 ) prepared via two-step solution-process still remains obscure. Here, we clarified the molecular-competing-reacted process of NH 2 CH═NH 2 I (FAI) and CH 3 NH 3 I (MAI) with PbI 2 (DMSO) x complex in dimethyl sulfoxide (DMSO) and diethyl ether (DE) catalytic solvent system in the sequential two-step solution-process. The microscopic dynamics was characterized via the characterizations of in situ photoluminescence spectra. In addition, we found that the thermal stability of the perovskite films suffered from the residual solvent with high boiling point, for example, DMSO. The further DE treatment could promote the volatility process of DMSO and accelerate the crystallization process of perovskite films. The highest PCE over 19% with slight hysteresis effect was eventually obtained with a reproducible FA 0.88 MA 0.12 PbI 3 solar cell, which displayed a constant power output within 100 s upon light soaking and stable PCE output within 30 d in the thermal stability test.

Molecular Strategies for Morphology Control in Semiconducting Polymers for Optoelectronics.

PubMed

Rahmanudin, Aiman; Sivula, Kevin

2017-06-28

Solution-processable semiconducting polymers have been explored over the last decades for their potential applications in inexpensively fabricated transistors, diodes and photovoltaic cells. However, a remaining challenge in the field is to control the solid-state self-assembly of polymer chains in thin films devices, as the aspects of (semi)crystallinity, grain boundaries, and chain entanglement can drastically affect intra-and inter-molecular charge transport/transfer and thus device performance. In this short review we examine how the aspects of molecular weight and chain rigidity affect solid-state self-assembly and highlight molecular engineering strategies to tune thin film morphology. Side chain engineering, flexibly linking conjugation segments, and block co-polymer strategies are specifically discussed with respect to their effect on field effect charge carrier mobility in transistors and power conversion efficiency in solar cells. Example systems are taken from recent literature including work from our laboratories to illustrate the potential of molecular engineering semiconducting polymers.

Performance testing of 3D point cloud software

NASA Astrophysics Data System (ADS)

Varela-González, M.; González-Jorge, H.; Riveiro, B.; Arias, P.

2013-10-01

LiDAR systems are being used widely in recent years for many applications in the engineering field: civil engineering, cultural heritage, mining, industry and environmental engineering. One of the most important limitations of this technology is the large computational requirements involved in data processing, especially for large mobile LiDAR datasets. Several software solutions for data managing are available in the market, including open source suites, however, users often unknown methodologies to verify their performance properly. In this work a methodology for LiDAR software performance testing is presented and four different suites are studied: QT Modeler, VR Mesh, AutoCAD 3D Civil and the Point Cloud Library running in software developed at the University of Vigo (SITEGI). The software based on the Point Cloud Library shows better results in the loading time of the point clouds and CPU usage. However, it is not as strong as commercial suites in working set and commit size tests.

From Zero to Integration in Eight Months, the Dawn Ground Data System Engineering Challenge

NASA Technical Reports Server (NTRS)

Dubon, Lydia P.

2006-01-01

The Dawn GDS Team met the SC Sim integration challenge in eight months. The GDS System Engineering approach in response to the SC Simintegration challenge, focused on a set of key practices: decomposition of project request into manageable requirements; integration of multiple ground disciplines and experts into a focused team effort; risk management thru management of expectations; and aggregation of intermediate products into a final product. By maintaining a a system-level focus, the overall systems engineering process unified team GDS Team members with a common goal: the success of the ground system as a whole and not just the success of their individual expert contributions. Incorporation of Agile-type development efforts were aligned with a risk strategy based on team-oriented principles and expectations management, thus achieving a more stable baseline solution without compromising the integrity of the GDS design.

Engineering Globular Protein Vesicles through Tunable Self-Assembly of Recombinant Fusion Proteins

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

Jang, Yeongseon; Choi, Won Tae; Heller, William T.

Vesicles assembled from folded, globular proteins have potential for functions different from traditional lipid or polymeric vesicles. However, they also present challenges in understanding the assembly process and controlling vesicle properties. From detailed investigation of the assembly behavior of recombinant fusion proteins, this work reports a simple strategy to engineer protein vesicles containing functional, globular domains. This is achieved through tunable self-assembly of recombinant globular fusion proteins containing leucine zippers and elastin-like polypeptides. The fusion proteins form complexes in solution via high affinity binding of the zippers, and transition through dynamic coacervates to stable hollow vesicles upon warming. The thermalmore » driving force, which can be tuned by protein concentration or temperature, controls both vesicle size and whether vesicles are single or bi-layered. Lastly, these results provide critical information to engineer globular protein vesicles via self-assembly with desired size and membrane structure.« less

Engineering Globular Protein Vesicles through Tunable Self-Assembly of Recombinant Fusion Proteins

DOE PAGES

Jang, Yeongseon; Choi, Won Tae; Heller, William T.; ...

2017-07-27

Vesicles assembled from folded, globular proteins have potential for functions different from traditional lipid or polymeric vesicles. However, they also present challenges in understanding the assembly process and controlling vesicle properties. From detailed investigation of the assembly behavior of recombinant fusion proteins, this work reports a simple strategy to engineer protein vesicles containing functional, globular domains. This is achieved through tunable self-assembly of recombinant globular fusion proteins containing leucine zippers and elastin-like polypeptides. The fusion proteins form complexes in solution via high affinity binding of the zippers, and transition through dynamic coacervates to stable hollow vesicles upon warming. The thermalmore » driving force, which can be tuned by protein concentration or temperature, controls both vesicle size and whether vesicles are single or bi-layered. Lastly, these results provide critical information to engineer globular protein vesicles via self-assembly with desired size and membrane structure.« less

Hands on Education Through Student-Industry Partnerships

NASA Astrophysics Data System (ADS)

Brown, J.; Wolfson, M.; Morris, K.

2013-09-01

Lockheed Martin Space Systems Company has invested in the future generation of engineers by partially funding and mentoring CubeSat projects around the country. One CubeSat in particular, ALL-STAR, has shown how this industry/university partnership benefits both the students and their mentors. Students gain valuable insight into aspects of spacecraft design that aren't taught in classes. They also start learning about industry processes for designing, building, and testing satellites before ever working in that environment. Because of this experience, industry is getting more qualified engineers starting fresh out of college. In addition Lockheed Martin's partnership with the university will allow them to use the students to help build affordable CubeSats for internal and customer's research and development projects. The mentoring also challenges the engineers to think differently about similar problems they face every day with their larger programs in order to make the solution simple and affordable.

Electrospraying and Electrospinning of Polymers for Biomedical Applications. Poly(Lactic-Co-Glycolic Acid) and Poly(Ethylene-Co-Vinylacetate). Appendix 2

NASA Technical Reports Server (NTRS)

Stitzel, Joel D.; Bowlin, Gary L.; Mansfield, Kevin; Wnek, Gary E.; Simpson, David G.

2000-01-01

Significant opportunities exist for the processing of polymers (homopolymers and blends) using electric fields. Specific attention is given here to electrospinning, but we note that electroaerosol formation and field-modulated film casting represent additional processing options. Of particular interest is the ability to generate polymer fibers of sub-micron dimensions using electrospinning, down to about 0.05 microns (50 nm), a size range that has been traditionally difficult to access. In our work, poly(lactic-co-glycolic acid), PLA/PGA, poly(lactic acid) PLA, and poly(ethylene-co-vinylacetate) (PEVA) have been deposited from solutions in methylene chloride or chloroform by electrospraying or electrospinning to afford morphologically tailored materials for tissue engineering and related applications. Low solution concentrations tend to favor electrostatic spraying ('electro-aerosolization') while higher concentrations lead to spinning on fibrous mats. Preliminary observations of muscle cell growth on PLA electrospun mats are reported.

10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation.

PubMed

Lan, Xinzheng; Voznyy, Oleksandr; García de Arquer, F Pelayo; Liu, Mengxia; Xu, Jixian; Proppe, Andrew H; Walters, Grant; Fan, Fengjia; Tan, Hairen; Liu, Min; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H

2016-07-13

Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics.

An Expert System Solution for the Quantitative Condition Assessment of Electrical Distribution Systems in the United States Air Force

DTIC Science & Technology

1991-09-01

Distribution system ... ......... 4 2. Architechture of an Expert system .. .............. 66 vi List of Tables Table Page 1. Prototype Component Model...expert system to properly process work requests Ln civil engineering (8:23). Electric Power Research Institute (EPRI). EPRI is a private organization ...used (51) Training Level. The level of training shop technicians receive, and the resulting proficiency, are important in all organizations . Experts 1

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

SAMS TL; GUILLOT S

Scoping laboratory scale tests were performed at the Chemical Engineering Department of the Georgia Institute of Technology (Georgia Tech), and the Hanford 222-S Laboratory, involving double-shell tank (DST) and single-shell tank (SST) Hanford waste simulants. These tests established the viability of the Lithium Hydrotalcite precipitation process as a solution to remove aluminum and recycle sodium hydroxide from the Hanford tank waste, and set the basis of a validation test campaign to demonstrate a Technology Readiness Level of 3.

Manufacturing Methods and Technology Program Plan, CY 1980.

DTIC Science & Technology

1980-09-01

AD-A092 2Ii3 &RMY INDUSTRIAL BASE ENGINEERING ACTIVITY ROCK ISLAND IL FIG 1346 ..ANIJPACTRItd METH4OS AND TECNOLOGY PROGRAM PLAN. CY 1960. (U) %EP 60... innovative solutions. For example, material handling, process tools and inspection systems must be computerized to achieve the desired operating economics and...to decrease expensive direct labor; however, the new systems must also be capable of economic layaway for periods of ten years or more, a situation

Polymer-based composites for aerospace: An overview of IMAST results

NASA Astrophysics Data System (ADS)

Milella, Eva; Cammarano, Aniello

2016-05-01

This paper gives an overview of technological results, achieved by IMAST, the Technological Cluster on Engineering of Polymeric Composite Materials and Structures, in the completed Research Projects in the aerospace field. In this sector, the Cluster developed different solutions: lightweight multifunctional fiber-reinforced polymer composites for aeronautic structures, advanced manufacturing processes (for the optimization of energy consumption and waste reduction) and multifunctional components (e.g., thermal, electrical, acoustic and fire resistance).

IEEE Computer Society/Software Engineering Institute Software Process Achievement (SPA) Award 2009

DTIC Science & Technology

2011-03-01

capabilities to our GDM. We also introduced software as a service ( SaaS ) as part our technology solutions and have further enhanced our ability to...model PROSPER Infosys production support methodology Q&P quality and productivity R&D research and development SaaS software as a service ... Software Development Life Cycle (SDLC) 23 Table 10: Scientific Estimation Coverage by Service Line 27 CMU/SEI-2011-TR-008 | vi CMU/SEI-2011

High performance alloy electroforming

NASA Technical Reports Server (NTRS)

Malone, G. A.; Winkelman, D. M.

1989-01-01

Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718.

Thrust Area Report, Engineering Research, Development and Technology

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

Langland, R. T.

1997-02-01

The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through our collaboration with U.S. industry in pursuit of the most cost- effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Programmore » has two important goals: (1) identify key technologies relevant to LLNL programs where we can establish unique competencies, and (2) conduct high-quality research and development to enhance our capabilities and establish ourselves as the world leaders in these technologies. To focus Engineering`s efforts technology {ital thrust areas} are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1996. The report provides timely summaries of objectives, methods, and key results from eight thrust areas: Computational Electronics and Electromagnetics; Computational Mechanics; Microtechnology; Manufacturing Technology; Materials Science and Engineering; Power Conversion Technologies; Nondestructive Evaluation; and Information Engineering. Readers desiring more information are encouraged to contact the individual thrust area leaders or authors. 198 refs., 206 figs., 16 tabs.« less

The placement of equipment in the Space Station Freedom using constraint based reasoning

NASA Technical Reports Server (NTRS)

Tanner, Steve; Fennel, Randy

1991-01-01

This paper describes the Rack Equipment Placement and Optimization System. The primary objective of this system is to assist engineers with the placement of equipment into the racks of the modules of Space Station Freedom. It accomplishes this by showing a user where equipment placement is possible and by generating potential layouts. The system uses an explicit representation of integration constraints to search for potential solutions for individual rack equipment items. A simulated annealing process is being evaluated for total solution generation as well. Versions of this system are in use now and are assisting with the development of the Space Station Freedom at the Marshall Space Flight Center in Huntsville, Alabama.

A heat transfer model for a hot helium airship

NASA Astrophysics Data System (ADS)

Rapert, R. M.

1987-06-01

Basic heat transfer empirical and analytic equations are applied to a double envelope airship concept which uses heated Helium in the inner envelope to augment and control gross lift. The convective and conductive terms lead to a linear system of five equations for the concept airship, with the nonlinear radiation terms included by an iterative solution process. The graphed results from FORTRAN program solutions are presented for the variables of interest. These indicate that a simple use of airship engine exhaust heat gives more than a 30 percent increase in gross airship lift. Possibly more than 100 percent increase can be achieved if a 'stream injection' heating system, with associated design problems, is used.

Effective Design of Educational Virtual Reality Applications for Medicine Using Knowledge-Engineering Techniques

ERIC Educational Resources Information Center

Górski, Filip; Bun, Pawel; Wichniarek, Radoslaw; Zawadzki, Przemyslaw; Hamrol, Adam

2017-01-01

Effective medical and biomedical engineering education is an important problem. Traditional methods are difficult and costly. That is why Virtual Reality is often used for that purpose. Educational medical VR is a well-developed IT field, with many available hardware and software solutions. Current solutions are prepared without methodological…

Small Engine Technology (SET) - Task 14 Axisymmetric Engine Simulation Environment

NASA Technical Reports Server (NTRS)

Miller, Max J.

1999-01-01

As part of the NPSS (Numerical Propulsion Simulation System) project, NASA Lewis has a goal of developing an U.S. industry standard for an axisymmetric engine simulation environment. In this program, AlliedSignal Engines (AE) contributed to this goal by evaluating the ENG20 software and developing support tools. ENG20 is a NASA developed axisymmetric engine simulation tool. The project was divided into six subtasks which are summarized below: Evaluate the capabilities of the ENG20 code using an existing test case to see how this procedure can capture the component interactions for a full engine. Link AE's compressor and turbine axisymmetric streamline curvature codes (UD0300M and TAPS) with ENG20, which will provide the necessary boundary conditions for an ENG20 engine simulation. Evaluate GE's Global Data System (GDS), attempt to use GDS to do the linking of codes described in Subtask 2 above. Use a turbofan engine test case to evaluate various aspects of the system, including the linkage of UD0300M and TAPS with ENG20 and the GE data storage system. Also, compare the solution results with cycle deck results, axisymmetric solutions (UD0300M and TAPS), and test data to determine the accuracy of the solution. Evaluate the order of accuracy and the convergence time for the solution. Provide a monthly status report and a final formal report documenting AE's evaluation of ENG20. Provide the developed interfaces that link UD0300M and TAPS with ENG20, to NASA. The interface that links UD0300M with ENG20 will be compatible with the industr,, version of UD0300M.

ICFA Beam Dynamics Newsletter

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

Pikin, A.

2017-11-21

Electron beam ion sources technology made significant progress since 1968 when this method of producing highly charged ions in a potential trap within electron beam was proposed by E. Donets. Better understanding of physical processes in EBIS, technological advances and better simulation tools determined significant progress in key EBIS parameters: electron beam current and current density, ion trap capacity, attainable charge states. Greatly increased the scope of EBIS and EBIT applications. An attempt is made to compile some of EBIS engineering problems and solutions and to demonstrate a present stage of understanding the processes and approaches to build a bettermore » EBIS.« less

On the nature of bias and defects in the software specification process

NASA Technical Reports Server (NTRS)

Straub, Pablo A.; Zelkowitz, Marvin V.

1992-01-01

Implementation bias in a specification is an arbitrary constraint in the solution space. This paper describes the problem of bias. Additionally, this paper presents a model of the specification and design processes describing individual subprocesses in terms of precision/detail diagrams and a model of bias in multi-attribute software specifications. While studying how bias is introduced into a specification we realized that software defects and bias are dual problems of a single phenomenon. This was used to explain the large proportion of faults found during the coding phase at the Software Engineering Laboratory at NASA/GSFC.

Manufacturing process applications team (MATeam)

NASA Technical Reports Server (NTRS)

Bangs, E. R.; Meyer, J. D.

1978-01-01

Activities of the manufacturing applications team (MATeam) in effecting widespread transfer of NASA technology to aid in the solution of manufacturing problems in the industrial sector are described. During the program's first year of operation, 450 companies, industry associations, and government agencies were contacted, 150 manufacturing problems were documented, and 20 potential technology transfers were identified. Although none of the technology transfers has been commercialized and put in use, several are in the applications engineering phase, and others are in the early stages of implementation. The technology transfer process is described and guidelines used for the preparation of problems statements are included.

A study on the indirect urea dosing method in the Selective Catalytic Reduction system

NASA Astrophysics Data System (ADS)

Brzeżański, M.; Sala, R.

2016-09-01

This article presents the results of studies on concept solution of dosing urea in a gas phase in a selective catalytic reduction system. The idea of the concept was to heat-up and evaporate the water urea solution before introducing it into the exhaust gas stream. The aim was to enhance the processes of urea converting into ammonia, what is the target reductant for nitrogen oxides treatment. The study was conducted on a medium-duty Euro 5 diesel engine with exhaust line consisting of DOC catalyst, DPF filter and an SCR system with a changeable setup allowing to dose the urea in liquid phase (regular solution) and to dose it in a gas phase (concept solution). The main criteria was to assess the effect of physical state of urea dosed on the NOx conversion ratio in the SCR catalyst. In order to compare both urea dosing methods a special test procedure was developed which consisted of six test steps covering a wide temperature range of exhaust gas generated at steady state engine operation condition. Tests were conducted for different urea dosing quantities defined by the a equivalence ratio. Based on the obtained results, a remarkable improvement in NOx reduction was found for gas urea application in comparison to the standard liquid urea dosing. Measured results indicate a high potential to increase an efficiency of the SCR catalyst by using a gas phase urea and provide the basis for further scientific research on this type of concept.

NASA Engineering and Technology Advancement Office: A proposal to the administrator

NASA Technical Reports Server (NTRS)

Schulze, Norman R.

1993-01-01

NASA has continually had problems with cost, schedule, performance, reliability, quality, and safety aspects in programs. Past solutions have not provided the answers needed, and a major change is needed in the way of doing business. A new approach is presented for consideration. These problems are all engineering matters, and therefore, require engineering solutions. Proper engineering tools are needed to fix engineering problems. Headquarters is responsible for providing the management structure to support programs with appropriate engineering tools. A guide to define those tools and an approach for putting them into place is provided. Recommendations include establishing a new Engineering and Technology Advancement Office, requesting a review of this proposal by the Administrator since this subject requires a top level decision. There has been a wide peer review conducted by technical staff at Headquarters, the Field Installations, and others in industry as discussed.

DEM Solutions Develops Answers to Modeling Lunar Dust and Regolith

NASA Technical Reports Server (NTRS)

Dunn, Carol Anne; Calle, Carlos; LaRoche, Richard D.

2010-01-01

With the proposed return to the Moon, scientists like NASA-KSC's Dr. Calle are concerned for a number of reasons. We will be staying longer on the planet's surface, future missions may include dust-raising activities, such as excavation and handling of lunar soil and rock, and we will be sending robotic instruments to do much of the work for us. Understanding more about the chemical and physical properties of lunar dust, how dust particles interact with each other and with equipment surfaces and the role of static electricity build-up on dust particles in the low-humidity lunar environment is imperative to the development of technologies for removing and preventing dust accumulation, and successfully handling lunar regolith. Dr. Calle is currently working on the problems of the electrostatic phenomena of granular and bulk materials as they apply to planetary surfaces, particularly to those of Mars and the Moon, and is heavily involved in developing instrumentation for future planetary missions. With this end in view, the NASA Kennedy Space Center's Innovative Partnerships Program Office partnered with OEM Solutions, Inc. OEM Solutions is a global leader in particle dynamics simulation software, providing custom solutions for use in tackling tough design and process problems related to bulk solids handling. Customers in industries such as pharmaceutical, chemical, mineral, and materials processing as well as oil and gas production, agricultural and construction, and geo-technical engineering use OEM Solutions' EDEM(TradeMark) software to improve the design and operation of their equipment while reducing development costs, time-to-market and operational risk. EDEM is the world's first general-purpose computer-aided engineering (CAE) tool to use state-of-the-art discrete element modeling technology for the simulation and analysis of particle handling and manufacturing operations. With EDEM you'can quickly and easily create a parameterized model of your granular solids system. Computer-aided design (CAD) models of real particles can be imported to obtain an accurate representation of their shape. EDEM(TradeMark) uses particle-scale behavior models to simulate bulk solids behavior. In addition to particle size and shape, the models can account for physical properties of particles along with interaction between particles and with equipment surfaces and surrounding media, as needed to define the physics of a particular process.

Solving bi-level optimization problems in engineering design using kriging models

NASA Astrophysics Data System (ADS)

Xia, Yi; Liu, Xiaojie; Du, Gang

2018-05-01

Stackelberg game-theoretic approaches are applied extensively in engineering design to handle distributed collaboration decisions. Bi-level genetic algorithms (BLGAs) and response surfaces have been used to solve the corresponding bi-level programming models. However, the computational costs for BLGAs often increase rapidly with the complexity of lower-level programs, and optimal solution functions sometimes cannot be approximated by response surfaces. This article proposes a new method, namely the optimal solution function approximation by kriging model (OSFAKM), in which kriging models are used to approximate the optimal solution functions. A detailed example demonstrates that OSFAKM can obtain better solutions than BLGAs and response surface-based methods, and at the same time reduce the workload of computation remarkably. Five benchmark problems and a case study of the optimal design of a thin-walled pressure vessel are also presented to illustrate the feasibility and potential of the proposed method for bi-level optimization in engineering design.

Big data analytics as a service infrastructure: challenges, desired properties and solutions

NASA Astrophysics Data System (ADS)

Martín-Márquez, Manuel

2015-12-01

CERN's accelerator complex generates a very large amount of data. A large volumen of heterogeneous data is constantly generated from control equipment and monitoring agents. These data must be stored and analysed. Over the decades, CERN's researching and engineering teams have applied different approaches, techniques and technologies for this purpose. This situation has minimised the necessary collaboration and, more relevantly, the cross data analytics over different domains. These two factors are essential to unlock hidden insights and correlations between the underlying processes, which enable better and more efficient daily-based accelerator operations and more informed decisions. The proposed Big Data Analytics as a Service Infrastructure aims to: (1) integrate the existing developments; (2) centralise and standardise the complex data analytics needs for CERN's research and engineering community; (3) deliver real-time, batch data analytics and information discovery capabilities; and (4) provide transparent access and Extract, Transform and Load (ETL), mechanisms to the various and mission-critical existing data repositories. This paper presents the desired objectives and properties resulting from the analysis of CERN's data analytics requirements; the main challenges: technological, collaborative and educational and; potential solutions.

3D printing facilitated scaffold-free tissue unit fabrication.

PubMed

Tan, Yu; Richards, Dylan J; Trusk, Thomas C; Visconti, Richard P; Yost, Michael J; Kindy, Mark S; Drake, Christopher J; Argraves, William Scott; Markwald, Roger R; Mei, Ying

2014-06-01

Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing microdroplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit microdroplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation.

Evaluation of Saltzman and phenoldisulfonic acid methods for determining NO/sub x/ in engine exhaust gases

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

Groth, R.H.; Calabro, D.S.

1969-11-01

The two methods normally used for the analysis of NO/sub x/ are the Saltzman and the phenoldisulfonic acid technique. This paper describes an evaluation of these wet chemical methods to determine their practical application to engine exhaust gas analysis. Parameters considered for the Saltzman method included bubbler collection efficiency, NO to NO/sub 2/ conversion efficiency, masking effect of other contaminants usually present in exhaust gases and the time-temperature effect of these contaminants on store developed solutions. Collection efficiency and the effects of contaminants were also considered for the phenoldisulfonic acid method. Test results indicated satisfactory collection and conversion efficiencies formore » the Saltzman method, but contaminants seriously affected the measurement accuracy particularly if the developed solution was stored for a number of hours at room temperature before analysis. Storage at 32/sup 0/F minimized effect. The standard procedure for the phenoldisulfonic acid method gave good results, but the process was found to be too time consuming for routine analysis and measured only total NO/sub x/. 3 references, 9 tables.« less

Cascade Optimization Strategy for Aircraft and Air-Breathing Propulsion System Concepts

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Lavelle, Thomas M.; Hopkins, Dale A.; Coroneos, Rula M.

1996-01-01

Design optimization for subsonic and supersonic aircraft and for air-breathing propulsion engine concepts has been accomplished by soft-coupling the Flight Optimization System (FLOPS) and the NASA Engine Performance Program analyzer (NEPP), to the NASA Lewis multidisciplinary optimization tool COMETBOARDS. Aircraft and engine design problems, with their associated constraints and design variables, were cast as nonlinear optimization problems with aircraft weight and engine thrust as the respective merit functions. Because of the diversity of constraint types and the overall distortion of the design space, the most reliable single optimization algorithm available in COMETBOARDS could not produce a satisfactory feasible optimum solution. Some of COMETBOARDS' unique features, which include a cascade strategy, variable and constraint formulations, and scaling devised especially for difficult multidisciplinary applications, successfully optimized the performance of both aircraft and engines. The cascade method has two principal steps: In the first, the solution initiates from a user-specified design and optimizer, in the second, the optimum design obtained in the first step with some random perturbation is used to begin the next specified optimizer. The second step is repeated for a specified sequence of optimizers or until a successful solution of the problem is achieved. A successful solution should satisfy the specified convergence criteria and have several active constraints but no violated constraints. The cascade strategy available in the combined COMETBOARDS, FLOPS, and NEPP design tool converges to the same global optimum solution even when it starts from different design points. This reliable and robust design tool eliminates manual intervention in the design of aircraft and of air-breathing propulsion engines where it eases the cycle analysis procedures. The combined code is also much easier to use, which is an added benefit. This paper describes COMETBOARDS and its cascade strategy and illustrates the capability of the combined design tool through the optimization of a subsonic aircraft and a high-bypass-turbofan wave-rotor-topped engine.

Microrheological Characterization of Collagen Systems: From Molecular Solutions to Fibrillar Gels

PubMed Central

Shayegan, Marjan; Forde, Nancy R.

2013-01-01

Collagen is the most abundant protein in the extracellular matrix (ECM), where its structural organization conveys mechanical information to cells. Using optical-tweezers-based microrheology, we investigated mechanical properties both of collagen molecules at a range of concentrations in acidic solution where fibrils cannot form and of gels of collagen fibrils formed at neutral pH, as well as the development of microscale mechanical heterogeneity during the self-assembly process. The frequency scaling of the complex shear modulus even at frequencies of ∼10 kHz was not able to resolve the flexibility of collagen molecules in acidic solution. In these solutions, molecular interactions cause significant transient elasticity, as we observed for 5 mg/ml solutions at frequencies above ∼200 Hz. We found the viscoelasticity of solutions of collagen molecules to be spatially homogeneous, in sharp contrast to the heterogeneity of self-assembled fibrillar collagen systems, whose elasticity varied by more than an order of magnitude and in power-law behavior at different locations within the sample. By probing changes in the complex shear modulus over 100-minute timescales as collagen self-assembled into fibrils, we conclude that microscale heterogeneity appears during early phases of fibrillar growth and continues to develop further during this growth phase. Experiments in which growing fibrils dislodge microspheres from an optical trap suggest that fibril growth is a force-generating process. These data contribute to understanding how heterogeneities develop during self-assembly, which in turn can help synthesis of new materials for cellular engineering. PMID:23936454

Molecular Approach to Conjugated Polymers with Biomimetic Properties.

PubMed

Baek, Paul; Voorhaar, Lenny; Barker, David; Travas-Sejdic, Jadranka

2018-06-13

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. Applications such as tissue engineering, biosensing, drug delivery, and wearable electronics require biomimetic materials that can translate the physiological and chemical processes of biological systems, such as organs, tissues. and cells, into electrical signals and vice versa. However, the difference in the physical nature of soft biological elements and rigid electronic materials calls for new conductive or electroactive materials with added biomimetic properties that can bridge the gap. Soft electronics that utilize organic materials, such as conjugated polymers, can bring many important features to bioelectronics. Among the many advantages of conjugated polymers, the ability to modulate the biocompatibility, solubility, functionality, and mechanical properties through side chain engineering can alleviate the issues of mechanical mismatch and provide better interface between the electronics and biological elements. Additionally, conjugated polymers, being both ionically and electrically conductive through reversible doping processes provide means for direct sensing and stimulation of biological processes in cells, tissues, and organs. In this Account, we focus on our recent progress in molecular engineering of conjugated polymers with tunable biomimetic properties, such as biocompatibility, responsiveness, stretchability, self-healing, and adhesion. Our approach is general and versatile, which is based on functionalization of conjugated polymers with long side chains, commonly polymeric or biomolecules. Applications for such materials are wide-ranging, where we have demonstrated conductive, stimuli-responsive antifouling, and cell adhesive biointerfaces that can respond to external stimuli such as temperature, salt concentration, and redox reactions, the processes that in turn modify and reversibly switch the surface properties. Furthermore, utilizing the advantageous chemical, physical, mechanical and functional properties of the grafts, we progressed into grafting of the long side chains onto conjugated polymers in solution, with the vision of synthesizing solution-processable conjugated graft copolymers with biomimetic functionalities. Examples of the developed materials to date include rubbery and adhesive photoluminescent plastics, biomolecule-functionalized electrospun biosensors, thermally and dually responsive photoluminescent conjugated polymers, and tunable self-healing, adhesive, and stretchable strain sensors, advanced functional biocidal polymers, and filtration membranes. As outlined in these examples, the applications of these biomimetic, conjugated polymers are still in the development stage toward truly printable, organic bioelectronic devices. However, in this Account, we advocate that molecular engineering of conjugated polymers is an attractive approach to a versatile class of organic electronics with both ionic and electrical conductivity as well as mechanical properties required for next-generation bioelectronics.

Minimal algorithm for running an internal combustion engine

NASA Astrophysics Data System (ADS)

Stoica, V.; Borborean, A.; Ciocan, A.; Manciu, C.

2018-01-01

The internal combustion engine control is a well-known topic within automotive industry and is widely used. However, in research laboratories and universities the use of a control system trading is not the best solution because of predetermined operating algorithms, and calibrations (accessible only by the manufacturer) without allowing massive intervention from outside. Laboratory solutions on the market are very expensive. Consequently, in the paper we present a minimal algorithm required to start-up and run an internal combustion engine. The presented solution can be adapted to function on performance microcontrollers available on the market at the present time and at an affordable price. The presented algorithm was implemented in LabView and runs on a CompactRIO hardware platform.

A novel route in bone tissue engineering: magnetic biomimetic scaffolds.

PubMed

Bock, N; Riminucci, A; Dionigi, C; Russo, A; Tampieri, A; Landi, E; Goranov, V A; Marcacci, M; Dediu, V

2010-03-01

In recent years, interest in tissue engineering and its solutions has increased considerably. In particular, scaffolds have become fundamental tools in bone graft substitution and are used in combination with a variety of bio-agents. However, a long-standing problem in the use of these conventional scaffolds lies in the impossibility of re-loading the scaffold with the bio-agents after implantation. This work introduces the magnetic scaffold as a conceptually new solution. The magnetic scaffold is able, via magnetic driving, to attract and take up in vivo growth factors, stem cells or other bio-agents bound to magnetic particles. The authors succeeded in developing a simple and inexpensive technique able to transform standard commercial scaffolds made of hydroxyapatite and collagen in magnetic scaffolds. This innovative process involves dip-coating of the scaffolds in aqueous ferrofluids containing iron oxide nanoparticles coated with various biopolymers. After dip-coating, the nanoparticles are integrated into the structure of the scaffolds, providing the latter with magnetization values as high as 15 emu g(-)(1) at 10 kOe. These values are suitable for generating magnetic gradients, enabling magnetic guiding in the vicinity and inside the scaffold. The magnetic scaffolds do not suffer from any structural damage during the process, maintaining their specific porosity and shape. Moreover, they do not release magnetic particles under a constant flow of simulated body fluids over a period of 8 days. Finally, preliminary studies indicate the ability of the magnetic scaffolds to support adhesion and proliferation of human bone marrow stem cells in vitro. Hence, this new type of scaffold is a valuable candidate for tissue engineering applications, featuring a novel magnetic guiding option. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

%22Trojan Horse%22 strategy for deconstruction of biomass for biofuels production.

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

Simmons, Blake Alexander; Sinclair, Michael B.; Yu, Eizadora

2011-02-01

Production of renewable biofuels to displace fossil fuels currently consumed in the transportation sector is a pressing multiagency national priority (DOE/USDA/EERE). Currently, nearly all fuel ethanol is produced from corn-derived starch. Dedicated 'energy crops' and agricultural waste are preferred long-term solutions for renewable, cheap, and globally available biofuels as they avoid some of the market pressures and secondary greenhouse gas emission challenges currently facing corn ethanol. These sources of lignocellulosic biomass are converted to fermentable sugars using a variety of chemical and thermochemical pretreatments, which disrupt cellulose and lignin cross-links, allowing exogenously added recombinant microbial enzymes to more efficiently hydrolyzemore » the cellulose for 'deconstruction' into glucose. This process is plagued with inefficiencies, primarily due to the recalcitrance of cellulosic biomass, mass transfer issues during deconstruction, and low activity of recombinant deconstruction enzymes. Costs are also high due to the requirement for enzymes and reagents, and energy-intensive cumbersome pretreatment steps. One potential solution to these problems is found in synthetic biology-engineered plants that self-produce a suite of cellulase enzymes. Deconstruction can then be integrated into a one-step process, thereby increasing efficiency (cellulose-cellulase mass-transfer rates) and reducing costs. The unique aspects of our approach are the rationally engineered enzymes which become Trojan horses during pretreatment conditions. During this study we rationally engineered Cazy enzymes and then integrated them into plant cells by multiple transformation techniques. The regenerated plants were assayed for first expression of these messages and then for the resulting proteins. The plants were then subjected to consolidated bioprocessing and characterized in detail. Our results and possible implications of this work on developing dedicated energy crops and their advantage in a consolidated bioprocessing system.« less

Development of a Twin-spool Turbofan Engine Simulation Using the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

NASA Technical Reports Server (NTRS)

Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Johathan S.

2014-01-01

The Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3 of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.

Team-Based Development of Medical Devices: An Engineering-Business Collaborative.

PubMed

Eberhardt, Alan W; Johnson, Ophelia L; Kirkland, William B; Dobbs, Joel H; Moradi, Lee G

2016-07-01

There is a global shift in the teaching methodology of science and engineering toward multidisciplinary, team-based processes. To meet the demands of an evolving technical industry and lead the way in engineering education, innovative curricula are essential. This paper describes the development of multidisciplinary, team-based learning environments in undergraduate and graduate engineering curricula focused on medical device design. In these programs, students actively collaborate with clinicians, professional engineers, business professionals, and their peers to develop innovative solutions to real-world problems. In the undergraduate senior capstone courses, teams of biomedical engineering (BME) and business students have produced and delivered numerous functional prototypes to satisfied clients. Pursuit of commercialization of devices has led to intellectual property (IP) disclosures and patents. Assessments have indicated high levels of success in attainment of student learning outcomes and student satisfaction with their undergraduate design experience. To advance these projects toward commercialization and further promote innovative team-based learning, a Master of Engineering (MEng) in Design and Commercialization was recently launched. The MEng facilitates teams of graduate students in engineering, life sciences, and business who engage in innovation-commercialization (IC) projects and coursework that take innovative ideas through research and development (R&D) to create marketable devices. The activities are structured with students working together as a "virtual company," with targeted outcomes of commercialization (license agreements and new start-ups), competitive job placement, and/or career advancement.

Mechanical Design of Spacecraft

NASA Technical Reports Server (NTRS)

1962-01-01

In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

Analysis of rotary engine combustion processes based on unsteady, three-dimensional computations

NASA Technical Reports Server (NTRS)

Raju, M. S.; Willis, E. A.

1990-01-01

A new computer code was developed for predicting the turbulent and chemically reacting flows with sprays occurring inside of a stratified charge rotary engine. The solution procedure is based on an Eulerian Lagrangian approach where the unsteady, three-dimensional Navier-Stokes equations for a perfect gas mixture with variable properties are solved in generalized, Eulerian coordinates on a moving grid by making use of an implicit finite volume, Steger-Warming flux vector splitting scheme, and the liquid phase equations are solved in Lagrangian coordinates. Both the details of the numerical algorithm and the finite difference predictions of the combustor flow field during the opening of exhaust and/or intake, and also during fuel vaporization and combustion, are presented.

Analysis of rotary engine combustion processes based on unsteady, three-dimensional computations

NASA Technical Reports Server (NTRS)

Raju, M. S.; Willis, E. A.

1989-01-01

A new computer code was developed for predicting the turbulent, and chemically reacting flows with sprays occurring inside of a stratified charge rotary engine. The solution procedure is based on an Eulerian Lagrangian approach where the unsteady, 3-D Navier-Stokes equations for a perfect gas mixture with variable properties are solved in generalized, Eulerian coordinates on a moving grid by making use of an implicit finite volume, Steger-Warming flux vector splitting scheme, and the liquid phase equations are solved in Lagrangian coordinates. Both the details of the numerical algorithm and the finite difference predictions of the combustor flow field during the opening of exhaust and/or intake, and also during fuel vaporization and combustion, are presented.

Designing a combined casting mold for manufacture of a gasoline centrifugal pump body using CAD/CAM-systems

NASA Astrophysics Data System (ADS)

Galin, N. E.; Ogol, I. I.; Chervach, Yu B.; Dammer, V. Kh; Ru, Jia Hong

2017-02-01

The present paper examines designing of a combined casting mold for manufacture of a gasoline centrifugal pump body. The paper offers technological solutions for obtaining high quality castings at the testing stage of the finished mold. The paper is intended for practical use and prepared by order of JSC ‘Tomsk Electrical Engineering Plant’ using software and equipment of the department ‘Technologies of Computer-Aided Machinery Manufacturing’ of the Tomsk Polytechnic University (TPU) under the economic contract within state import substitution program. In preparing the paper, CAD/CAM-systems KOMPAS-3D and PowerMILL were used. In 2015, the designed casting mold was introduced into the production process at JSC ‘Tomsk Electrical Engineering Plant’.

The Role of Content Knowledge in Ill-Structured Problem Solving for High School Physics Students

NASA Astrophysics Data System (ADS)

Milbourne, Jeff; Wiebe, Eric

2018-02-01

While Physics Education Research has a rich tradition of problem-solving scholarship, most of the work has focused on more traditional, well-defined problems. Less work has been done with ill-structured problems, problems that are better aligned with the engineering and design-based scenarios promoted by the Next Generation Science Standards. This study explored the relationship between physics content knowledge and ill-structured problem solving for two groups of high school students with different levels of content knowledge. Both groups of students completed an ill-structured problem set, using a talk-aloud procedure to narrate their thought process as they worked. Analysis of the data focused on identifying students' solution pathways, as well as the obstacles that prevented them from reaching "reasonable" solutions. Students with more content knowledge were more successful reaching reasonable solutions for each of the problems, experiencing fewer obstacles. These students also employed a greater variety of solution pathways than those with less content knowledge. Results suggest that a student's solution pathway choice may depend on how she perceives the problem.

Using MD simulations to calculate how solvents modulate solubility

PubMed Central

Liu, Shuai; Cao, Shannon; Hoang, Kevin; Young, Kayla L.; Paluch, Andrew S.; Mobley, David L.

2016-01-01

Here, our interest is in predicting solubility in general, and we focus particularly on predicting how the solubility of particular solutes is modulated by the solvent environment. Solubility in general is extremely important, both for theoretical reasons – it provides an important probe of the balance between solute-solute and solute-solvent interactions – and for more practical reasons, such as how to control the solubility of a given solute via modulation of its environment, as in process chemistry and separations. Here, we study how the change of solvent affects the solubility of a given compound. That is, we calculate relative solubilities. We use MD simulations to calculate relative solubility and compare our calculated values with experiment as well as with results from several other methods, SMD and UNIFAC, the latter of which is commonly used in chemical engineering design. We find that straightforward solubility calculations based on molecular simulations using a general small-molecule force field outperform SMD and UNIFAC both in terms of accuracy and coverage of the relevant chemical space. PMID:26878198

Melittin Aggregation in Aqueous Solutions: Insight from Molecular Dynamics Simulations.

PubMed

Liao, Chenyi; Esai Selvan, Myvizhi; Zhao, Jun; Slimovitch, Jonathan L; Schneebeli, Severin T; Shelley, Mee; Shelley, John C; Li, Jianing

2015-08-20

Melittin is a natural peptide that aggregates in aqueous solutions with paradigmatic monomer-to-tetramer and coil-to-helix transitions. Since little is known about the molecular mechanisms of melittin aggregation in solution, we simulated its self-aggregation process under various conditions. After confirming the stability of a melittin tetramer in solution, we observed—for the first time in atomistic detail—that four separated melittin monomers aggregate into a tetramer. Our simulated dependence of melittin aggregation on peptide concentration, temperature, and ionic strength is in good agreement with prior experiments. We propose that melittin mainly self-aggregates via a mechanism involving the sequential addition of monomers, which is supported by both qualitative and quantitative evidence obtained from unbiased and metadynamics simulations. Moreover, by combining computer simulations and a theory of the electrical double layer, we provide evidence to suggest why melittin aggregation in solution likely stops at the tetramer, rather than forming higher-order oligomers. Overall, our study not only explains prior experimental results at the molecular level but also provides quantitative mechanistic information that may guide the engineering of melittin for higher efficacy and safety.

Picturing the Earth: Geoscience in Public Art Abstract for AGU 2013: Geoscience through the Lens of Art. Author: Stacy Levy, Sere Ltd., Spring Mills, PA (Invited)

NASA Astrophysics Data System (ADS)

Levy, S.

2013-12-01

Public places such as parks, urban plazas, transportation centers and educational institutions offer the opportunity to reach many people in the course of daily life. Yet these public spaces are often devoid of any substantive information about the local environment and natural processes that have shaped it. Art is a particularly effective means to visualize environmental phenomena. Art has the ability to translate the processes of nature into visual information that communicates with clarity and beauty. People often have no connection to the world through which they walk: no sense of their place in the local watershed or where the rainwater goes once it hits the ground. Creating an awareness of place is critical first step for people to understand the changes in their world. Art can be a gateway for understanding geo-scientific concepts that are not frequently made accessible in a visual manner And art requires scientific knowledge to inform an accurate visualization of nature. Artists must collaborate with scientists in order to create art that informs the public about environmental processes. There is a new current in the design world that combines art and technology to create artful solutions to site issues such as storm water runoff, periodic flooding and habitat destruction. Instead of being considered functionless, art is now given a chance to do some real work on the site. This new combination of function and aesthetic concerns will have a major impact on how site issues are perceived. Site concerns that were once considered obstacles can become opportunities to visualize and celebrate how problems can be solved. This sort of artful solutions requires teamwork across many disciplines. In my presentation I will speak about various ways of I have visualized the invisible processes of the natural world in my projects. I will share eight of my permanent and temporary art commissions that are collaborations with scientists and engineers. These works reveal wetland habitats, tides, prevailing winds, rain and microorganisms, and water pollution. In examining each project I will detail the essential collaborations with scientists and engineers that brought the projects to fruition. I will discuss how the cross-discipline approach of scientists, engineers and designers made effective and artful solutions to site issues, and created visually stimulating and educational places. I will also look at the role of truth and metaphor in art and compare how accuracy and data collection have differing thresholds in art and in science.

Design Steps for Physic STEM Education Learning in Secondary School

NASA Astrophysics Data System (ADS)

Teevasuthonsakul, C.; Yuvanatheeme, V.; Sriput, V.; Suwandecha, S.

2017-09-01

This study aimed to develop the process of STEM Education activity design used in Physics subjects in the Thai secondary schools. The researchers have conducted the study by reviewing the literature and related works, interviewing Physics experts, designing and revising the process accordingly, and experimenting the designed process in actual classrooms. This brought about the five-step process of STEM Education activity design which Physics teachers applied to their actual teaching context. The results from the after-class evaluation revealed that the students’ satisfaction level toward Physics subject and critical thinking skill was found higher statistically significant at p < .05. Moreover, teachers were advised to integrate the principles of science, mathematics, technology, and engineering design process as the foundation when creating case study of problems and solutions.

Biological plywood film formation from para-nematic liquid crystalline organization.

PubMed

Aguilar Gutierrez, Oscar F; Rey, Alejandro D

2017-11-15

In vitro non-equilibrium chiral phase ordering processes of biomacromolecular solutions offer a systematic and reproducible way of generating material architectures found in Nature, such as biological plywoods. Accelerated progress in biomimetic engineering of mesoscopic plywoods and other fibrous structures requires a fundamental understanding of processing and transport principles. In this work we focus on collagen I based materials and structures to find processing conditions that lead to defect-free collagen films displaying the helicoidal plywood architecture. Here we report experimentally-guided theory and simulations of the chiral phase ordering of collagen molecules through water solvent evaporation of pre-aligned dilute collagen solutions. We develop, implement and a posteriori validate an integrated liquid crystal chiral phase ordering-water transport model that captures the essential features of spatio-temporal chiral structure formation in shrinking film domains due to directed water loss. Three microstructural (texture) modes are identified depending on the particular value of the time-scale ratio defined by collagen rotational diffusion to water translational diffusion. The magnitude of the time scale ratio provides the conditions for the synchronization of the helical axis morphogenesis with the increase in the mesogen concentration due to water loss. Slower than critical water removal rates leads to internal multiaxial cellular patterns, reminiscent of the classical columnar-equiaxed metallurgical casting structures. Excessive water removal rates lead to destabilization of the chiral axis and multidomain defected films. The predictions of the integrated model are in qualitative agreement with experimental results and can potentially guide solution processing of other bio-related mesogenic solutions that seek to mimic the architecture of biological fibrous composites.

Developing teaching process for enhancing students' mathematical problem solving in the 21st century through STEM education

NASA Astrophysics Data System (ADS)

Prawvichien, Sutthaporn; Siripun, Kulpatsorn; Yuenyong, Chokchai

2018-01-01

The STEM education could provide the context for students' learning in the 21st century. The Mathematical problem solving requires a context which simulates real life in order to give students experience of the power of mathematics in the world around them. This study aimed to develop the teaching process for enhancing students' mathematical problem solving in the 21st century through STEM education. The paper will clarify the STEM learning activities about graph theories regarding on the 6 steps of engineering design process. These include identify a challenge, exploring ideas, designing and planning, doing and developing, test and evaluate, and present the solution. The learning activities will start from the Identify a challenge stage which provides the northern part of Thailand flooding situation in order to set the students' tasks of develop the solutions of providing the routes of fastest moving people away from the flooding areas. The explore ideas stage will provide activities for enhance students to learn some knowledge based for designing the possible solutions. This knowledge based could focus on measuring, geometry, graph theory, and mathematical process. The design and plan stage will ask students to model the city based on the map and then provide the possible routes. The doing and development stage will ask students to develop the routes based on their possible model. The test and evaluating will ask students to clarify how to test and evaluate the possible routes, and then test it. The present solution stage will ask students to present the whole process of designing routes. Then, the paper will discuss how these learning activities could enhance students' mathematical problem solving. The paper may have implication for STEM education in school setting.

Ninth Thermal and Fluids Analysis Workshop Proceedings

NASA Technical Reports Server (NTRS)

Sakowski, Barbara (Compiler)

1999-01-01

The Ninth Thermal and Fluids Analysis Workshop (TFAWS 98) was held at the Ohio Aerospace Institute in Cleveland, Ohio from August 31 to September 4, 1998. The theme for the hands-on training workshop and conference was "Integrating Computational Fluid Dynamics and Heat Transfer into the Design Process." Highlights of the workshop (in addition to the papers published herein) included an address by the NASA Chief Engineer, Dr. Daniel Mulville; a CFD short course by Dr. John D. Anderson of the University of Maryland; and a short course by Dr. Robert Cochran of Sandia National Laboratories. In addition, lectures and hands-on training were offered in the use of several cutting-edge engineering design and analysis-oriented CFD and Heat Transfer tools. The workshop resulted in international participation of over 125 persons representing aerospace and automotive industries, academia, software providers, government agencies, and private corporations. The papers published herein address issues and solutions related to the integration of computational fluid dynamics and heat transfer into the engineering design process. Although the primary focus is aerospace, the topics and ideas presented are applicable to many other areas where these and other disciplines are interdependent.

Industrial Processes to Reduce Generation of Hazardous Waste at DoD facilities. Phase 3 Report. Summary of Projects of Excellence Workshops

DTIC Science & Technology

1985-12-01

cation impurities from the plating solution and anodes to oxidize trivalent chromium to hexavalent chromium . Hexa- . valent chromium ions remain on the...corrosion, or to improve its engineering properties (harlness, durability, solderability, or frictional characteristics). Chromium ic used principally...facturing consists of machining the worn part or stripping a portion of the old plate, overplating it with a thick layer of chromium (hard chrome plating

SimBRS: A University/Industry Consortium Focused on Simulation Based Solutions for Ground Vehicles

DTIC Science & Technology

2009-07-29

plan is to use the SimBRS contract mechanism to streamline a process that applies research funds into a managed program, that is cognizant to the... designs . Therefore, the challenge for the SimBRS team is to establish an approach based on the capacity of measured data and simulations to support ...by systematically relating appropriate results from measurements and applied research in engineering and science. In turn, basic research and

Flow-Directed Crystallization for Printed Electronics.

PubMed

Qu, Ge; Kwok, Justin J; Diao, Ying

2016-12-20

The solution printability of organic semiconductors (OSCs) represents a distinct advantage for materials processing, enabling low-cost, high-throughput, and energy-efficient manufacturing with new form factors that are flexible, stretchable, and transparent. While the electronic performance of OSCs is not comparable to that of crystalline silicon, the solution processability of OSCs allows them to complement silicon by tackling challenging aspects for conventional photolithography, such as large-area electronics manufacturing. Despite this, controlling the highly nonequilibrium morphology evolution during OSC printing remains a challenge, hindering the achievement of high electronic device performance and the elucidation of structure-property relationships. Many elegant morphological control methodologies have been developed in recent years including molecular design and novel processing approaches, but few have utilized fluid flow to control morphology in OSC thin films. In this Account, we discuss flow-directed crystallization as an effective strategy for controlling the crystallization kinetics during printing of small molecule and polymer semiconductors. Introducing the concept of flow-directed crystallization to the field of printed electronics is inspired by recent advances in pharmaceutical manufacturing and flow processing of flexible-chain polymers. Although flow-induced crystallization is well studied in these areas, previous findings may not apply directly to the field of printed electronics where the molecular structures (i.e., rigid π-conjugated backbone decorated with flexible side chains) and the intermolecular interactions (i.e., π-π interactions, quadrupole interactions) of OSCs differ substantially from those of pharmaceuticals or flexible-chain polymers. Another critical difference is the important role of solvent evaporation in open systems, which defines the flow characteristics and determines the crystallization kinetics and pathways. In other words, flow-induced crystallization is intimately coupled with the mass transport processes driven by solvent evaporation during printing. In this Account, we will highlight these distinctions of flow-directed crystallization for printed electronics. In the context of solution printing of OSCs, the key issue that flow-directed crystallization addresses is the kinetics mismatch between crystallization and various transport processes during printing. We show that engineering fluid flows can tune the kinetics of OSC crystallization by expediting the nucleation and crystal growth processes, significantly enhancing thin film morphology and device performance. For small molecule semiconductors, nucleation can be enhanced and patterned by directing the evaporative flux via contact line engineering, and defective crystal growth can be alleviated by enhancing mass transport to yield significantly improved coherence length and reduced grain boundaries. For conjugated polymers, extensional and shear flow can expedite nucleation through flow-induced conformation change, facilitating the control of microphase separation, degree of crystallinity, domain alignment, and percolation. Although the nascent concept of flow-directed solution printing has not yet been widely adopted in the field of printed electronics, we anticipate that it can serve as a platform technology in the near future for improving device performance and for systematically tuning thin film morphology to construct structure-property relationships. From a fundamental perspective, it is imperative to develop a better understanding of the effects of fluid flow and mass transport on OSC crystallization as these processes are ubiquitous across all solution processing techniques and can critically impact charge transport properties.

Zinc Removal from the Aqueous Solutions by the Chemically Modified Biosorbents.

PubMed

Rajczykowski, Krzysztof; Sałasińska, Oktawia; Loska, Krzysztof

2018-01-01

Biosorbents are the natural origin adsorbents, which popularity in environmental engineering is steadily increasing due to their low price, ease of acquisition, and lack of the toxic properties. Presented research aimed to analyze the possibility of chemical modification of the straw, which is a characteristic waste in the Polish agriculture, to improve its biosorption properties with respect to removal of selected metals from aquatic solutions. Biosorbents used during the tests was a barley straw that was shredded to a size in the range of 0.2-1.0 mm. The biosorption process was performed for aqueous solutions of zinc at a pH 5. Two different modifications of straw were analyzed: esterification with methanol and modification using the citric acid at elevated temperature. The results, obtained during the research, show a clear improvement in sorption capacity of the straw modified by the citric acid. In the case of straw modified with methanol, it has been shown that the effectiveness of zinc biosorption process was even a twice lower with respect to the unmodified straw. Moreover, it was concluded that the removal of analyzed metals was based mainly on the ion-exchange adsorption mechanism by releasing a calcium and magnesium ions from the straw surface to the solution. Graphical Abstractᅟ.

Adsorptive separation in bioprocess engineering

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

Huang, E.W.Y.

1987-01-01

The invention and development of an energy-efficient separation technique for recovery of desired chemicals from biomass conversion would greatly enhance the economic viability of this bioprocess. Adsorptive separation of several chemicals from aqueous solution was studied in this thesis. The desired species were recovered from the dilute aqueous solution by using crosslinked polyvinylpyridine resin to effect selective sorption. The sorbed chemicals were then removed from the resin by either thermal regeneration or elution with some appropriate desorbents. The effects of temperature, pH value, and solute concentration on resin swelling were investigated. The adsorption equilibrium isotherms, resin capacities and resin selectivitiesmore » of methanol, ethanol, 1-propanol, isopropanol, glycerol, acetone, 1-butanol, tert-butanol, and 2,3-butanediol were determined to study the homologies. Furthermore, acetic acid, butyric acid, hydrochloric acid, lactic acid, and sulfuric acid were recovered from very dilute aqueous solutions. The concentration of the sorbed chemical in the stationary phase can be many times higher than in the mobile phase for some acids. Finally, different types of equilibrium isotherms were used to fit the experimental data. A mathematical model was developed by using the theory of interference to predict the breakthrough curves and the process efficiency to provide information for large-scale process design and development.« less

Evaporation of NaCl solution from porous media with mixed wettability

NASA Astrophysics Data System (ADS)

Bergstad, Mina; Shokri, Nima

2016-05-01

Evaporation of saline water from porous media is ubiquitous in many processes including soil salinization, crop production, and CO2 sequestration in deep saline acquirer. It is controlled by the transport properties of porous media, atmospheric conditions, and properties of the evaporating saline solution. In the present study, the effects of mixed wettability conditions on the general dynamics of water evaporation from porous media saturated with NaCl solution were investigated. To do so, we conducted a comprehensive series of evaporation experiments using sand mixtures containing different fractions of hydrophobic grains saturated with NaCl solutions. Our results showed that increasing fraction of hydrophobic grains in the mixed wettability sand pack had minor impact on the evaporative mass losses due to the presence of salt whose precipitation patterns were significantly influenced by the mixed wettability condition. Through macroscale and microscale investigations, we found formation of patchy efflorescence in the case of mixed wettability sand pack as opposed to crusty efflorescence in the case of completely hydrophilic porous media. Furthermore, the presence of salty water and hydrophobic grains in the sand pack significantly influenced the general dynamics and morphology of the receding drying front. Our results extend the understanding of the saline water evaporation from porous media with direct applications to various hydrological and engineering processes.

Dual-Band Modulation of Visible and Near-Infrared Light Transmittance in an All-Solution-Processed Hybrid Micro-Nano Composite Film.

PubMed

Liang, Xiao; Chen, Mei; Guo, Shumeng; Zhang, Lanying; Li, Fasheng; Yang, Huai

2017-11-22

Smart windows with controllable visible and near-infrared light transmittance can significantly improve the building's energy efficiency and inhabitant comfort. However, most of the current smart window technology cannot achieve the target of ideal solar control. Herein, we present a novel all-solution-processed hybrid micronano composite smart material that have four optical states to separately modulate the visible and NIR light transmittance through voltage and temperature, respectively. This dual-band optical modulation was achieved by constructing a phase-separated polymer framework, which contains the microsized liquid crystals domains with a negative dielectric constant and tungsten-doped vanadium dioxide (W-VO 2 ) nanocrystals (NCs). The film with 2.5 wt % W-VO 2 NCs exhibits transparency at normal condition, and the passage of visible light can be reversibly and actively regulated between 60.8% and 1.3% by external applied voltage. Also, the transmittance of NIR light can be reversibly and passively modulated between 59.4% and 41.2% by temperature. Besides, the film also features easy all-solution processability, fast electro-optical (E-O) response time, high mechanical strength, and long-term stability. The as-prepared film provides new opportunities for next-generation smart window technology, and the proposed strategy is conductive to engineering novel hybrid inorganic-organic functional matters.

Promises and Limitations of RFI Canceling Solutions

NASA Astrophysics Data System (ADS)

Fisher, J. R.

2004-05-01

Recent years have seen a kindling of interest in signal processing solutions to radio frequency interference (RFI) to astronomical observations. Over a dozen refereed papers and several dozen conference presentations on the subject are now in the astronomical and engineering literature. This work builds on several decades of signal processing development in the fields of acoustics and communications for which there are a number of standard texts. Radio astronomy has the unique requirement that interference must be suppressed below very low detection thresholds before the scientific results of observations can be considered reliable. These detection thresholds are several orders of magnitude lower than is typical of communications signal levels. Initial trials of coherent cancellation of TV and satellite signals and blanking of pulsed interference, such as radar and aircraft signals, are encouraging, but the signal processing power required for useful bandwidths is sobering. Simultaneous cancellation of many signals and compensation for multi-path propagation effects of distant transmitters add to the processing load and are challenges that remain to be tackled. Spectrum management is becoming increasingly complex with greater emphasis on spectrum sharing in the time and spacial domains. This requires a better understanding of long-distance propagation effects and the techniques and economics of signal separation to guide the protection of the scientific use of the radio spectrum. The traditional concept of frequency allocations will be only one aspect of spectrum management in the coming years. Active users of the spectrum will expect us to devote some of our engineering and managerial resources to spectrum sharing agreements, Hence, we need to continually build a firm technical footing upon which to base our negotiating positions. The NRAO is operated for the National Science Foundation (NSF) by Associated Universities, Inc. (AUI), under a cooperative agreement.

About Distributed Simulation-based Optimization of Forming Processes using a Grid Architecture

NASA Astrophysics Data System (ADS)

Grauer, Manfred; Barth, Thomas

2004-06-01

Permanently increasing complexity of products and their manufacturing processes combined with a shorter "time-to-market" leads to more and more use of simulation and optimization software systems for product design. Finding a "good" design of a product implies the solution of computationally expensive optimization problems based on the results of simulation. Due to the computational load caused by the solution of these problems, the requirements on the Information&Telecommunication (IT) infrastructure of an enterprise or research facility are shifting from stand-alone resources towards the integration of software and hardware resources in a distributed environment for high-performance computing. Resources can either comprise software systems, hardware systems, or communication networks. An appropriate IT-infrastructure must provide the means to integrate all these resources and enable their use even across a network to cope with requirements from geographically distributed scenarios, e.g. in computational engineering and/or collaborative engineering. Integrating expert's knowledge into the optimization process is inevitable in order to reduce the complexity caused by the number of design variables and the high dimensionality of the design space. Hence, utilization of knowledge-based systems must be supported by providing data management facilities as a basis for knowledge extraction from product data. In this paper, the focus is put on a distributed problem solving environment (PSE) capable of providing access to a variety of necessary resources and services. A distributed approach integrating simulation and optimization on a network of workstations and cluster systems is presented. For geometry generation the CAD-system CATIA is used which is coupled with the FEM-simulation system INDEED for simulation of sheet-metal forming processes and the problem solving environment OpTiX for distributed optimization.

Effect of microstructure on high-temperature mechanical behavior of nickel-base superalloys for turbine disc applications

NASA Astrophysics Data System (ADS)

Sharpe, Heather Joan

2007-05-01

Engineers constantly seek advancements in the performance of aircraft and power generation engines, including, lower costs and emissions, and improved fuel efficiency. Nickel-base superalloys are the material of choice for turbine discs, which experience some of the highest temperatures and stresses in the engine. Engine performance is proportional to operating temperatures. Consequently, the high-temperature capabilities of disc materials limit the performance of gas-turbine engines. Therefore, any improvements to engine performance necessitate improved alloy performance. In order to take advantage of improvements in high-temperature capabilities through tailoring of alloy microstructure, the overall objectives of this work were to establish relationships between alloy processing and microstructure, and between microstructure and mechanical properties. In addition, the projected aimed to demonstrate the applicability of neural network modeling to the field of Ni-base disc alloy development and behavior. The first phase of this work addressed the issue of how microstructure varies with heat treatment and by what mechanisms these structures are formed. Further it considered how superalloy composition could account for microstructural variations from the same heat treatment. To study this, four next-generation Ni-base disc alloys were subjected to various controlled heat-treatments and the resulting microstructures were then quantified. These quantitative results were correlated to chemistry and processing, including solution temperature, cooling rate, and intermediate hold temperature. A complex interaction of processing steps and chemistry was found to contribute to all features measured; grain size, precipitate distribution, grain boundary serrations. Solution temperature, above a certain threshold, and cooling rate controlled grain size, while cooling rate and intermediate hold temperature controlled precipitate formation and grain boundary serrations. Diffusion, both intergranular and grain boundary, was identified as the most pertinent mechanism. Variations in chemistry between alloys created different amounts of gamma/gamma' misfit strain, which affected precipitate size and morphology. Next the question of how a disc alloy with differing microstructures would respond to constant or cyclic stresses as a function of time was addressed. To this end, mechanical testing at elevated temperatures was conducted, including tensile, hardness, creep deformation, creep crack growth and fatigue crack growth. Overall, mechanical properties were primarily related to the cooling rate during processing with hold temperatures being secondary. Whether the impact was positive or negative depended on the behavior under consideration. Fast cooling rates improved yield strength and creep resistance, but were detrimental to creep crack growth rates. The ability of precipitate particles to impede dislocation motion was the most frequently cited mechanism behind structure-property interaction. Neural network models were successfully generated for processing-structure predictions, as well as for structure-property predictions. Training data was limited, none-the-less models were able to predict outputs with minimal relative errors. This was achieved through careful balance between the number of inputs and amount of training data. Despite the demonstrated correlation between microstructure and yield strength, microstructural quantities did not need to be directly inputted. Neural networks were sufficiently sensitive as to infer these effects from processing and chemistry inputs. This result improves the efficiency of this technique, while also demonstrating the capability of neural network techniques. A full program of heat-treatment, microstructure quantification, mechanical testing, and neural network modeling was successfully applied to next generation Ni-base disc alloys. From this work the mechanisms of processing-structure and structure-property relationships were studied. Further, testing results were used to demonstrate the applicability of machine-learning techniques to the development and optimization of this family of superalloys.

Avoid problems during distillation column startups

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

Sloley, A.W.

1996-07-01

The startup of a distillation column is the end product of the design process. Indeed, startup is the culmination of the theory and practice of designing the column to meet the process objectives. The author will direct most of this discussion towards column revamps due to their inherent complexity; however, the points apply equally to new columns, as well. The most important question that must be answered prior to a startup is how will the distillation system changes affect initial startup, process control of the system, and normal day-to-day operations? How will the operators run the system? Steady-state distillation-column simulationsmore » alone cannot provide an authoritative answer and, indeed, engineers` over-reliance on software too often has led them to ignore many practical aspects. Computer modeling, while an important engineering tool, is not reality. Distillation columns are real functioning pieces of equipment that require practical skills to successfully modify. They are not steady-state solutions that result from converged computer simulations. Early planning, coupled with thorough inspections and comprehensive reviews of instrumentation and procedures, can play a key role in assuring smooth startups.« less

Development of a decision support system for analysis and solutions of prolonged standing in the workplace.

PubMed

Halim, Isa; Arep, Hambali; Kamat, Seri Rahayu; Abdullah, Rohana; Omar, Abdul Rahman; Ismail, Ahmad Rasdan

2014-06-01

Prolonged standing has been hypothesized as a vital contributor to discomfort and muscle fatigue in the workplace. The objective of this study was to develop a decision support system that could provide systematic analysis and solutions to minimize the discomfort and muscle fatigue associated with prolonged standing. The integration of object-oriented programming and a Model Oriented Simultaneous Engineering System were used to design the architecture of the decision support system. Validation of the decision support system was carried out in two manufacturing companies. The validation process showed that the decision support system produced reliable results. The decision support system is a reliable advisory tool for providing analysis and solutions to problems related to the discomfort and muscle fatigue associated with prolonged standing. Further testing of the decision support system is suggested before it is used commercially.

Development of a Decision Support System for Analysis and Solutions of Prolonged Standing in the Workplace

PubMed Central

Halim, Isa; Arep, Hambali; Kamat, Seri Rahayu; Abdullah, Rohana; Omar, Abdul Rahman; Ismail, Ahmad Rasdan

2014-01-01

Background Prolonged standing has been hypothesized as a vital contributor to discomfort and muscle fatigue in the workplace. The objective of this study was to develop a decision support system that could provide systematic analysis and solutions to minimize the discomfort and muscle fatigue associated with prolonged standing. Methods The integration of object-oriented programming and a Model Oriented Simultaneous Engineering System were used to design the architecture of the decision support system. Results Validation of the decision support system was carried out in two manufacturing companies. The validation process showed that the decision support system produced reliable results. Conclusion The decision support system is a reliable advisory tool for providing analysis and solutions to problems related to the discomfort and muscle fatigue associated with prolonged standing. Further testing of the decision support system is suggested before it is used commercially. PMID:25180141

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

PubMed

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

2012-01-01

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

Engineering Play: Exploring Associations with Executive Function, Mathematical Ability, and Spatial Ability in Preschool

NASA Astrophysics Data System (ADS)

Gold, Zachary Samuel

Engineering play is a new perspective on preschool education that views constructive play as an engineering design process that parallels the way engineers think and work when they develop engineered solutions to human problems (Bairaktarova, Evangelou, Bagiati, & Brophy, 2011). Early research from this perspective supports its use in framing play as a key learning context. However, no research to date has examined associations between engineering play and other factors linked with early school success, such as executive function, mathematical ability, and spatial ability. Additionally, more research is needed to further validate a new engineering play observational measure. This study had two main goals: (1) to gather early validity data on the engineering play measure as a potentially useful instrument for documenting the occurrence of children's engineering play behaviors in educational contexts, such as block play. This was done by testing the factor structure of the engineering play behaviors in this sample and their association with preschoolers' planning, a key aspect of the engineering design process; (2) to explore associations between preschoolers' engineering play and executive function, mathematical ability, and spatial ability. Participants included 110 preschoolers (62 girls; 48 boys; M = 58.47 months) from 10 classrooms in the Midwest United States coded for their frequency of engagement in each of the nine engineering play behaviors. A confirmatory factor analysis resulted in one engineering play factor including six of the engineering play behaviors. A series of marginal regression models revealed that the engineering play factor was significantly and positively associated with the spatial horizontal rotation transformation. However, engineering play was not significantly related to planning ability, executive function, informal mathematical abilities, or other spatial transformation skills. Follow-up analyses revealed significant positive associations between engineering play and planning, executive function, and geometry for only a subgroup of children (n = 27) who had individualized education program (IEP) status. This was the first of a series of studies planned to evaluate the potential of the engineering play perspective as a tool for understanding young children's development and learning across multiple developmental domains. Although most hypotheses regarding engineering play and cognitive skills were not supported, the study provided partial evidence for the reliability and validity of the engineering play observation measure. Future research should include larger sample sizes with more statistical power, continued refinement of the engineering play observation measure, examination of potential associations with specific early learning domains, including spatial ability and language, and more comparisons of engineering play between typically developing children and children with disabilities.

Hybrid Electric Energy Storages: Their Specific Features and Application (Review)

NASA Astrophysics Data System (ADS)

Popel', O. S.; Tarasenko, A. B.

2018-05-01

The article presents a review of various aspects related to development and practical use of hybrid electric energy storages (i.e., those uniting different energy storage technologies and devices in an integrated system) in transport and conventional and renewable power engineering applications. Such devices, which were initially developed for transport power installations, are increasingly being used by other consumers characterized by pronounced nonuniformities of their load schedule. A range of tasks solved using such energy storages is considered. It is shown that, owing to the advent of new types of energy storages and the extended spectrum of their performance characteristics, new possibilities for combining different types of energy storages and for developing hybrid systems have become available. This, in turn, opens up the possibility of making energy storages with better mass and dimension characteristics and achieving essentially lower operational costs. The possibility to secure more comfortable (base) operating modes of primary sources of energy (heat engines and renewable energy source based power installations) and to achieve a higher capacity utilization factor are unquestionable merits of hybrid energy storages. Development of optimal process circuit solutions, as well as energy conversion and control devices facilitating the fullest utilization of the properties of each individual energy storage included in the hybrid system, is among the important lines of research carried out in this field in Russia and abroad. Our review of existing developments has shown that there are no universal technical solutions in this field (the specific features of a consumer have an essential effect on the process circuit solutions and on the composition of a hybrid energy storage), a circumstance that dictates the need to extend the scope of investigations in this promising field.

Paraffin-based hybrid rocket engines applications: A review and a market perspective

NASA Astrophysics Data System (ADS)

Mazzetti, Alessandro; Merotto, Laura; Pinarello, Giordano

2016-09-01

Hybrid propulsion technology for aerospace applications has received growing attention in recent years due to its important advantages over competitive solutions. Hybrid rocket engines have a great potential for several aeronautics and aerospace applications because of their safety, reliability, low cost and high performance. As a consequence, this propulsion technology is feasible for a number of innovative missions, including space tourism. On the other hand, hybrid rocket propulsion's main drawback, i.e. the difficulty in reaching high regression rate values using standard fuels, has so far limited the maturity level of this technology. The complex physico-chemical processes involved in hybrid rocket engines combustion are of major importance for engine performance prediction and control. Therefore, further investigation is ongoing in order to achieve a more complete understanding of such phenomena. It is well known that one of the most promising solutions for overcoming hybrid rocket engines performance limits is the use of liquefying fuels. Such fuels can lead to notably increased solid fuel regression rate due to the so-called "entrainment phenomenon". Among liquefying fuels, paraffin-based formulations have great potentials as solid fuels due to their low cost, availability (as they can be derived from industrial waste), low environmental impact and high performance. Despite the vast amount of literature available on this subject, a precise focus on market potential of paraffins for hybrid propulsion aerospace applications is lacking. In this work a review of hybrid rocket engines state of the art was performed, together with a detailed analysis of the possible applications of such a technology. A market study was carried out in order to define the near-future foreseeable development needs for hybrid technology application to the aforementioned missions. Paraffin-based fuels are taken into account as the most promising segment for market development.The present study is useful for driving future investigation and testing of paraffin-based fuels as solid fuels for hybrid propulsion technology, taking into account the needs of industrial applications of this technology.

"Trojan Horse" strategy for deconstruction of biomass for biofuels production.

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

Sinclair, Michael B.; Hadi, Masood Z.; Timlin, Jerilyn Ann

2008-08-01

Production of renewable biofuels to displace fossil fuels currently consumed in the transportation sector is a pressing multi-agency national priority. Currently, nearly all fuel ethanol is produced from corn-derived starch. Dedicated 'energy crops' and agricultural waste are preferred long-term solutions for renewable, cheap, and globally available biofuels as they avoid some of the market pressures and secondary greenhouse gas emission challenges currently facing corn ethanol. These sources of lignocellulosic biomass are converted to fermentable sugars using a variety of chemical and thermochemical pretreatments, which disrupt cellulose and lignin cross-links, allowing exogenously added recombinant microbial enzymes to more efficiently hydrolyze themore » cellulose for 'deconstruction' into glucose. This process is plagued with inefficiencies, primarily due to the recalcitrance of cellulosic biomass, mass transfer issues during deconstruction, and low activity of recombinant deconstruction enzymes. Costs are also high due to the requirement for enzymes and reagents, and energy-intensive and cumbersome pretreatment steps. One potential solution to these problems is found in synthetic biology; they propose to engineer plants that self-produce a suite of cellulase enzymes targeted to the apoplast for cleaving the linkages between lignin and cellulosic fibers; the genes encoding the degradation enzymes, also known as cellulases, are obtained from extremophilic organisms that grow at high temperatures (60-100 C) and acidic pH levels (<5). These enzymes will remain inactive during the life cycle of the plant but become active during hydrothermal pretreatment i.e., elevated temperatures. Deconstruction can be integrated into a one-step process, thereby increasing efficiency (cellulose-cellulase mass-transfer rates) and reducing costs. The proposed disruptive technologies address biomass deconstruction processes by developing transgenic plants encoding a suite of enzymes used in cellulosic deconstruction. The unique aspects of this technology are the rationally engineered, highly productive extremophilic enzymes, targeted to specific cellular locations (apoplast) and their dormancy during normal plant proliferation, which become Trojan horses during pretreatment conditions. They have been leveraging established Sandia's enzyme-engineering and imaging capabilities. Their technical approach not only targets the recalcitrance and mass-transfer problem during biomass degradation but also eliminates the costs associated with industrial-scale production of microbial enzymes added during processing.« less

The Evolution of Technology in the Deep Space Network: A History of the Advanced Systems Program

NASA Technical Reports Server (NTRS)

Layland, J. W.; Rauch, L. L.

1994-01-01

The Deep Space Network (DSN) of 1995 might be described as the evolutionary result of 45 years of deep space communication and navigation, together with the synergistic activities of radio science and radar and radio astronomy. But the evolution of the DSN did not just happen - it was carefully planned and created. The evolution of the DSN has been an ongoing engineering activity, and engineering is a process of problem solving under constraints, one of which is technology. In turn, technology is the knowledge base providing the capability and experience for practical application of various areas of science, when needed. The best engineering solutions result from optimization under the fewest constraints, and if technology needs are well anticipated (ready when needed), then the most effective engineering solution is possible. Throughout the history of the DSN it has been the goal and function of DSN advanced technology development (designated the DSN Advanced Systems Program from 1963 through 1994) to supply the technology needs of the DSN when needed, and thus to minimize this constraint on DSN engineering. Technology often takes considerable time to develop, and when that happens, it is important to have anticipated engineering needs; at times, this anticipation has been by as much as 15 years. Also, on a number of occasions, mission malfunctions or emergencies have resulted in unplanned needs for technology that has, in fact, been available from the reservoir of advanced technology provided by the DSN Advanced Systems Program. Sometimes, even DSN engineering personnel fail to realize that the organization of JPL permits an overlap of DSN advanced technology activities with subsequent engineering activities. This can result in the flow of advanced technology into DSN engineering in a natural and sometimes almost unnoticed way. In the following pages, we will explore some of the many contributions of the DSN Advanced Systems Program that were provided to DSN Engineering and Implementation. These contributions are, for the most part, unique capabilities that have met the requirements of flight projects for 45 years. These unique capabilities include not only the world's best deep-space communications system, but also outstanding competency in the fields of radio metric measurement, radar and radio astronomy, and radio science.

Services supporting collaborative alignment of engineering networks

NASA Astrophysics Data System (ADS)

Jansson, Kim; Uoti, Mikko; Karvonen, Iris

2015-08-01

Large-scale facilities such as power plants, process factories, ships and communication infrastructures are often engineered and delivered through geographically distributed operations. The competencies required are usually distributed across several contributing organisations. In these complicated projects, it is of key importance that all partners work coherently towards a common goal. VTT and a number of industrial organisations in the marine sector have participated in a national collaborative research programme addressing these needs. The main output of this programme was development of the Innovation and Engineering Maturity Model for Marine-Industry Networks. The recently completed European Union Framework Programme 7 project COIN developed innovative solutions and software services for enterprise collaboration and enterprise interoperability. One area of focus in that work was services for collaborative project management. This article first addresses a number of central underlying research themes and previous research results that have influenced the development work mentioned above. This article presents two approaches for the development of services that support distributed engineering work. Experience from use of the services is analysed, and potential for development is identified. This article concludes with a proposal for consolidation of the two above-mentioned methodologies. This article outlines the characteristics and requirements of future services supporting collaborative alignment of engineering networks.