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Sample records for electrochemical engine system

  1. Electrochemical Engineering.

    ERIC Educational Resources Information Center

    Alkire, Richard C.

    1983-01-01

    Discusses engineering ramifications of electrochemistry, focusing on current/potential distribution, evaluation of trade-offs between influences of different phenomena, use of dimensionless numbers to assist in scale-over to new operating conditions, and economics. Also provides examples of electrochemical engineering education content related to…

  2. Engineering electrochemical capacitor applications

    NASA Astrophysics Data System (ADS)

    Miller, John R.

    2016-09-01

    Electrochemical capacitor (EC) applications have broadened tremendously since EC energy storage devices were introduced in 1978. Then typical applications operated below 10 V at power levels below 1 W. Today many EC applications operate at voltages approaching 1000 V at power levels above 100 kW. This paper briefly reviews EC energy storage technology, shows representative applications using EC storage, and describes engineering approaches to design EC storage systems. Comparisons are made among storage systems designed to meet the same application power requirement but using different commercial electrochemical capacitor products.

  3. Electrochemical heat engine

    DOEpatents

    Elliott, Guy R. B.; Holley, Charles E.; Houseman, Barton L.; Sibbitt, Jr., Wilmer L.

    1978-01-01

    Electrochemical heat engines produce electrochemical work, and mechanical motion is limited to valve and switching actions as the heat-to-work cycles are performed. The electrochemical cells of said heat engines use molten or solid electrolytes at high temperatures. One or more reactions in the cycle will generate a gas at high temperature which can be condensed at a lower temperature with later return of the condensate to electrochemical cells. Sodium, potassium, and cesium are used as the working gases for high temperature cells (above 600 K) with halogen gases or volatile halides being used at lower temperature. Carbonates and halides are used as molten electrolytes and the solid electrolyte in these melts can also be used as a cell separator.

  4. Electrochemical energy engineering: a new frontier of chemical engineering innovation.

    PubMed

    Gu, Shuang; Xu, Bingjun; Yan, Yushan

    2014-01-01

    One of the grand challenges facing humanity today is a safe, clean, and sustainable energy system where combustion no longer dominates. This review proposes that electrochemical energy conversion could set the foundation for such an energy system. It further suggests that a simple switch from an acid to a base membrane coupled with innovative cell designs may lead to a new era of affordable electrochemical devices, including fuel cells, electrolyzers, solar hydrogen generators, and redox flow batteries, for which recent progress is discussed using the authors' work as examples. It also notes that electrochemical energy engineering will likely become a vibrant subdiscipline of chemical engineering and a fertile ground for chemical engineering innovation. To realize this vision, it is necessary to incorporate fundamental electrochemistry and electrochemical engineering principles into the chemical engineering curriculum. PMID:24702299

  5. A global thermo-electrochemical model for SOFC systems design and engineering

    NASA Astrophysics Data System (ADS)

    Petruzzi, L.; Cocchi, S.; Fineschi, F.

    At BMW AG in Munich high-temperature solid oxide fuel cells (SOFCs) are being developed as an auxiliary power unit (APU) for high-class car conveniences. Their design requires simulation of their thermo-electrochemical behaviour in all the conditions that may occur during operation (i.e. heat-up to about 600 °C, start-up to operating temperature, energy-delivering and cool-down). A global thermo-electrochemical model was developed for the whole system and a three-dimensional geometry code was performed using MATLAB programming language. The problems in developing SOFCs are now so many and so different that a very flexible code is necessary. Thus, the code was not only designed in order to simulate each of the operating conditions, but also to test different stack configurations, materials, etc. In every event, the code produces a time-dependent profile of temperatures, currents, electrical and thermal power density, gases concentrations for the whole system. The heat-up and start-up simulations allow: (1) to evaluate the time the cell stack needs to reach operating temperature from an initial temperature distribution, (2) to check the steepest temperature gradients occurring in the ceramic layers (which result in material stresses) and (3) to obtain important information about the pre-operating strategy. Simulation of energy-delivering gives a detailed profile of the temperatures, currents, power density, and allows to define the guidelines in system-controlling. Simulation of cooling-down gives important advises about insulation designing. The aim of this work is to build up a tool to clearly individuate the best designing criteria and operating strategy during the development and the engineering of a SOFC system.

  6. Electrochemical thermodynamic measurement system

    DOEpatents

    Reynier, Yvan; Yazami, Rachid; Fultz, Brent T.

    2009-09-29

    The present invention provides systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and electrochemical energy storage and conversion systems. Systems and methods of the present invention are configured for simultaneously collecting a suite of measurements characterizing a plurality of interconnected electrochemical and thermodynamic parameters relating to the electrode reaction state of advancement, voltage and temperature. Enhanced sensitivity provided by the present methods and systems combined with measurement conditions that reflect thermodynamically stabilized electrode conditions allow very accurate measurement of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and electrochemical systems, such as the energy, power density, current rate and the cycle life of an electrochemical cell.

  7. A Course in Electrochemical and Corrosion Engineering.

    ERIC Educational Resources Information Center

    Van Zee, John

    1985-01-01

    Describes a course designed to show similarities between electrochemistry and corrosion engineering and to show graduate students that electrochemical and corrosion engineering can be accomplished by extending their knowledge of chemical engineering models. Includes course outline, textbooks selected, and teaching methods used. (JN)

  8. PEM fuel cell stack performance using dilute hydrogen mixture. Implications on electrochemical engine system performance and design

    SciTech Connect

    Inbody, M.A.; Vanderborgh, N.E.; Hedstrom, J.C.; Tafoya, J.I.

    1996-12-31

    Onboard fuel processing to generate a hydrogen-rich fuel for PEM fuel cells is being considered as an alternative to stored hydrogen fuel for transportation applications. If successful, this approach, contrasted to operating with onboard hydrogen, utilizes the existing fuels infrastructure and provides required vehicle range. One attractive, commercial liquid fuels option is steam reforming of methanol. However, expanding the liquid methanol infrastructure will take both time and capital. Consequently technology is also being developed to utilize existing transportation fuels, such as gasoline or diesel, to power PEM fuel cell systems. Steam reforming of methanol generates a mixture with a dry gas composition of 75% hydrogen and 25% carbon dioxide. Steam reforming, autothermal reforming, and partial oxidation reforming of C{sub 2} and larger hydrocarbons produces a mixture with a more dilute hydrogen concentration (65%-40%) along with carbon dioxide ({approx}20%) and nitrogen ({approx}10%-40%). Performance of PEM fuel cell stacks on these dilute hydrogen mixtures will affect the overall electrochemical engine system design as well as the overall efficiency. The Los Alamos Fuel Cell Stack Test facility was used to access the performance of a PEM Fuel cell stack over the range of gas compositions chosen to replicate anode feeds from various fuel processing options for hydrocarbon and alcohol fuels. The focus of the experiments was on the anode performance with dilute hydrogen mixtures with carbon dioxide and nitrogen diluents. Performance with other anode feed contaminants, such as carbon monoxide, are not reported here.

  9. System level electrochemical principles

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1985-01-01

    The traditional electrochemical storage concepts are difficult to translate into high power, high voltage multikilowatt storage systems. The increased use of electronics, and the use of electrochemical couples that minimize the difficulties associated with the corrective measures to reduce the cell to cell capacity dispersion were adopted by battery technology. Actively cooled bipolar concepts are described which represent some attractive alternative system concepts. They are projected to have higher energy densities lower volumes than current concepts. They should be easier to scale from one capacity to another and have a closer cell to cell capacity balance. These newer storage system concepts are easier to manage since they are designed to be a fully integrated battery. These ideas are referred to as system level electrochemistry. The hydrogen-oxygen regenerative fuel cells (RFC) is probably the best example of the integrated use of these principles.

  10. Electrochemical hydrogen Storage Systems

    SciTech Connect

    Dr. Digby Macdonald

    2010-08-09

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not described in the

  11. Layered Systems Engineering Engines

    NASA Technical Reports Server (NTRS)

    Breidenthal, Julian C.; Overman, Marvin J.

    2009-01-01

    A notation is described for depicting the relationships between multiple, contemporaneous systems engineering efforts undertaken within a multi-layer system-of-systems hierarchy. We combined the concepts of remoteness of activity from the end customer, depiction of activity on a timeline, and data flow to create a new kind of diagram which we call a "Layered Vee Diagram." This notation is an advance over previous notations because it is able to be simultaneously precise about activity, level of granularity, product exchanges, and timing; these advances provide systems engineering managers a significantly improved ability to express and understand the relationships between many systems engineering efforts. Using the new notation, we obtain a key insight into the relationship between project duration and the strategy selected for chaining the systems engineering effort between layers, as well as insights into the costs, opportunities, and risks associated with alternate chaining strategies.

  12. Systems Engineering

    NASA Technical Reports Server (NTRS)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  13. Superstatistics in nanoscale electrochemical systems.

    PubMed

    García-Morales, Vladimir; Krischer, Katharina

    2011-12-01

    Stochastic electrochemical reaction steps on nanosized electrodes are non-Markovian when externally driven by an applied voltage. We show that, compared to the Markovian case (when external driving is absent), nanoscale electrochemical systems obey a superstatistics characterized by a superposition of Tsallis' q indices. The distribution of Tsallis' q indices along stochastic trajectories can be calculated from the electrochemical master equation and normal distributions from Boltzmann-Gibbs thermostatistics are recovered in the thermodynamic limit (the infinite electrode size limit). Although on the nanoscale the external control makes intricate correlations between the microstates, in the superstatistical frame one can still address the microstates as if they were uncorrelated. The resulting superstatistical entropic form is additive in this frame and Tsallis' indices have on the time-average values ≤ 1, which is, indeed, an example of a superstatistical system where no ad hoc distribution has to be assumed for the fluctuations; rather, the distribution is directly calculated from a mesoscopic master equation without freely adjustable parameters. PMID:22106266

  14. Novel electrochemical nickel metallization in silicon impedance engineering for mixed-signal system-on-chip crosstalk isolation

    NASA Astrophysics Data System (ADS)

    Zhang, Xi

    One of the major challenges for single chip radio frequency integrated circuits (RFIC's) built on Si is the RE crosstalk through the Si substrate. Noise from switching transient in digital circuits can be transmitted through Si substrate and degrades the performance of analog circuit elements. A highly conductive moat or Faraday cage type structure of through-the-wafer thickness in the Si substrate was demonstrated to be effective in shielding electromagnetic interference thereby reducing RE cross-talk in high performance mixed signal integrated circuits. Such a structure incorporated into the p- Si substrate was realized by electroless Ni metallization over selected regions with ultra-high-aspect-ratio macropores that was etched electrochemically in p- Si substrates. The metallization process was conducted by immersing the macroporous Si sample in an alkaline aqueous solution containing Ni2+ without a reducing agent. It was found that working at slightly elevated temperature, Ni 2+ was rapidly reduced and deposited in the macropores. During the wet chemical process, conformal metallization on the pore wall was achieved. The entire porous Si skeleton was gradually replaced by Ni along the extended duration of immersion. In a p-/p+ epi Si substrate used for high performance digital CMOS, the suppression of crosstalk by the arrayed metallic Ni via structure fabricated from the front p side was significant that the crosstalk went down to the noise floor of the conventional measurement instruments. The process and mechanism of forming such a Ni structure over the original Si were studied. Theoretical computation relevant to the process was carried out to show a good consistency with the experiments.

  15. Rapid electrochemical screening of engine coolants. Correlation of electrochemical potentiometric measurements with ASTM D 1384 glassware corrosion test

    SciTech Connect

    Doucet, G.P.; Jackson, J.M.; Kriegel, O.A.; Passwater, D.K.; Prieto, N.E.

    1999-08-01

    Engine coolants are typically subjected to comprehensive performance evaluations that involve multiple laboratory and field tests. These tests can take several weeks to conduct and can be expensive. The tests can involve everything from preliminary chemical screening to long term fleet tests. An important test conducted at the beginning of coolant formula development to screen the corrosion performance of engine coolants is described in ASTM D 1384. If the coolant formula passes the test, it is then subjected to more rigorous testing. Conducting the test described in ASTM D 1384 takes two weeks, and determining the coolant corrosion performance under several test parameters can takes resources and time that users seldom have. Therefore, it is very desirable to have tests that can be used for rapid screening and quality assurance of coolants. The purpose of this study was to conduct electrochemical tests that can ultimately be used for quick initial screening of engine coolants. The specific intent of the electrochemical tests is to use ASTM D 1384 as a model and to attempt to duplicate its results. Implementation of the electrochemical tests could accelerate the process of selecting promising coolant formulas and reduce coolant evaluation time and cost. Various electrochemical tests were conducted to determine the corrosion performance of several engine coolant formulas. The test results were compared to those obtained from the ASTM D 1384 test. These tests were conducted on the same metal specimens and under similar conditions as those used in the ASTM D 1384 test. The electrochemical tests included the determination of open circuit potential (OCP) for the various metal specimens, anodic and cathodic polarization curves for the various metal specimens, corrosion rate for metal specimens involved in a galvanic triad, and critical pitting potential (CPP) for aluminum (pitting of aluminum engine components and cooling systems is a cause for concern). The details for

  16. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-10-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

  17. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors.

    PubMed

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W; Chatterjee, Shahana; Erwin, William R; Bardhan, Rizia; Weiss, Sharon M; Pint, Cary L

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  18. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    PubMed Central

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  19. Electrochemical analysis of Shewanella oneidensis engineered to bind gold electrodes.

    PubMed

    Kane, Aunica L; Bond, Daniel R; Gralnick, Jeffrey A

    2013-02-15

    Growth in three-electrode electrochemical cells allows quantitative analysis of mechanisms involved in electron flow from dissimilatory metal reducing bacteria to insoluble electron acceptors. In these systems, gold electrodes are a desirable surface to study the electrophysiology of extracellular respiration, yet previous research has shown that certain Shewanella species are unable to form productive biofilms on gold electrodes. To engineer attachment of Shewanella oneidensis to gold, five repeating units of a synthetic gold-binding peptide (5rGBP) were integrated within an Escherichia coli outer membrane protein, LamB, and displayed on the outer surface of S. oneidensis. Expression of LamB-5rGBP increased cellular attachment of S. oneidensis to unpoised gold surfaces but was also associated with the loss of certain outer membrane proteins required for extracellular respiration. Loss of these outer membrane proteins during expression of LamB-5rGBP decreased the rate at which S. oneidensis was able to reduce insoluble iron, riboflavin, and electrodes. Moreover, poising the gold electrode resulted in repulsion of the engineered cells. This study provides a strategy to specifically immobilize bacteria to electrodes while also outlining challenges involved in merging synthetic biology approaches with native cellular pathways and cell surface charge. PMID:23656372

  20. Engineered peptide-based nanobiomaterials for electrochemical cell chip

    NASA Astrophysics Data System (ADS)

    Kafi, Md. Abdul; Cho, Hyeon-Yeol; Choi, Jeong-Woo

    2016-07-01

    Biomaterials having cell adhesion ability are considered to be integral part of a cell chip. A number of researches have been carried out to search for a suitable material for effective immobilization of cell on substrate. Engineered ECM materials or their components like collagen, Poly- l-Lysine (PLL), Arg-Gly-Asp (RGD) peptide have been extensively used for mammalian cell adhesion and proliferation with the aim of tissue regeneration or cell based sensing application. This review focuses on the various approaches for two- and three-dimensionally patterned nanostructures of a short peptide i.e. RGD peptide on chip surfaces together with their effects on cell behaviors and electrochemical measurements. Most of the study concluded with positive remarks on the well-oriented engineered RGD peptide over their homogenous thin film. The engineered RGD peptide not only influences cell adhesion, spreading and proliferation but also their periodic nano-arrays directly influence electrochemical measurements of the chips. The electrochemical signals found to be enhanced when RGD peptides were used in well-defined two-dimensional nano-arrays. The topographic alteration of three-dimensional structure of engineered RGD peptide was reported to be suitably contacted with the integrin receptors of cellular membrane which results indicated the enhanced cell-electrode adhesion and efficient electron exchange phenomenon. This enhanced electrochemical signal increases the sensitivity of the chip against the target analytes. Therefore, development of engineered cellular recognizable peptides and its 3D topological design for fabrication of cell chip will provide the synergetic effect on bio-affinity, sensitivity and accuracy for the in situ real-time monitoring of analytes.

  1. Engineering the bioelectrochemical interface using functional nanomaterials and microchip technique toward sensitive and portable electrochemical biosensors.

    PubMed

    Jia, Xiaofang; Dong, Shaojun; Wang, Erkang

    2016-02-15

    Electrochemical biosensors have played active roles at the forefront of bioanalysis because they have the potential to achieve sensitive, specific and low-cost detection of biomolecules and many others. Engineering the electrochemical sensing interface with functional nanomaterials leads to novel electrochemical biosensors with improved performances in terms of sensitivity, selectivity, stability and simplicity. Functional nanomaterials possess good conductivity, catalytic activity, biocompatibility and high surface area. Coupled with bio-recognition elements, these features can amplify signal transduction and biorecognition events, resulting in highly sensitive biosensing. Additionally, microfluidic electrochemical biosensors have attracted considerable attention on account of their miniature, portable and low-cost systems as well as high fabrication throughput and ease of scaleup. For example, electrochemical enzymetic biosensors and aptamer biosensors (aptasensors) based on the integrated microchip can be used for portable point-of-care diagnostics and environmental monitoring. This review is a summary of our recent progress in the field of electrochemical biosensors, including aptasensors, cytosensors, enzymatic biosensors and self-powered biosensors based on biofuel cells. We presented the advantages that functional nanomaterials and microfluidic chip technology bring to the electrochemical biosensors, together with future prospects and possible challenges. PMID:26001888

  2. Engineering Review Information System

    NASA Technical Reports Server (NTRS)

    Grems, III, Edward G. (Inventor); Henze, James E. (Inventor); Bixby, Jonathan A. (Inventor); Roberts, Mark (Inventor); Mann, Thomas (Inventor)

    2015-01-01

    A disciplinal engineering review computer information system and method by defining a database of disciplinal engineering review process entities for an enterprise engineering program, opening a computer supported engineering item based upon the defined disciplinal engineering review process entities, managing a review of the opened engineering item according to the defined disciplinal engineering review process entities, and closing the opened engineering item according to the opened engineering item review.

  3. The Impedance Response of Semiconductors: An Electrochemical Engineering Perspective.

    ERIC Educational Resources Information Center

    Orazem, Mark E.

    1990-01-01

    Shows that the principles learned in the study of mass transport, thermodynamics, and kinetics associated with electrochemical systems can be applied to the transport and reaction processes taking place within a semiconductor. Describes impedance techniques and provides several graphs illustrating impedance data for diverse circuit systems. (YP)

  4. System and method for networking electrochemical devices

    DOEpatents

    Williams, Mark C.; Wimer, John G.; Archer, David H.

    1995-01-01

    An improved electrochemically active system and method including a plurality of electrochemical devices, such as fuel cells and fluid separation devices, in which the anode and cathode process-fluid flow chambers are connected in fluid-flow arrangements so that the operating parameters of each of said plurality of electrochemical devices which are dependent upon process-fluid parameters may be individually controlled to provide improved operating efficiency. The improvements in operation include improved power efficiency and improved fuel utilization in fuel cell power generating systems and reduced power consumption in fluid separation devices and the like through interstage process fluid parameter control for series networked electrochemical devices. The improved networking method includes recycling of various process flows to enhance the overall control scheme.

  5. Sheet electrode for electrochemical systems

    DOEpatents

    Tsien, Hsue C.; Newby, Kenneth R.; Grimes, Patrick G.; Bellows, Richard J.

    1983-04-12

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  6. Low temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, Raouf O.; Brown, Alan P.; Yao, Neng-Ping

    1983-01-01

    A thermally regenerative electrochemical system including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the complexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  7. Low-temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, R.O.; Brown, A.P.; Yao, N.P.

    1982-04-21

    A thermally regenerative electrochemical system is described including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the ocmplexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  8. Space engine safety system

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Meyer, Claudia M.

    1991-01-01

    A rocket engine safety system is designed to initiate control procedures which will minimize damage to the engine and vehicle or test stand in the event of an engine failure. This report describes the features and the implementation issues associated with rocket engine safety systems. Specific concerns of safety systems applied to a space-based engine and long duration space missions are discussed. Examples of safety system features and architectures are given from recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, a general design and implementation process for rocket engine safety systems is presented.

  9. Space engine safety system

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Meyer, Claudia M.

    1991-01-01

    A rocket engine safety system was designed to initiate control procedures to minimize damage to the engine or vehicle or test stand in the event of an engine failure. The features and the implementation issues associated with rocket engine safety systems are discussed, as well as the specific concerns of safety systems applied to a space-based engine and long duration space missions. Examples of safety system features and architectures are given, based on recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, the general design and implementation process for rocket engine safety systems is presented.

  10. Surface design and engineering of hierarchical hybrid nanostructures for asymmetric supercapacitors with improved electrochemical performance.

    PubMed

    Achilleos, Demetra S; Hatton, T Alan

    2015-06-01

    With the current rising world demand for energy sufficiency, there is an increased necessity for the development of efficient energy storage devices. To address these needs, the scientific community has focused on the improvement of the electrochemical properties of the most well known energy storage devices; the Li-ion batteries and electrochemical capacitors, also called supercapacitors. Despite the fact that supercapacitors exhibit high power densities, good reversibility and long cycle life, they still exhibit lower energy densities than batteries, which limit their practical application. Various strategies have been employed to circumvent this problem, specifically targetting an increase in the specific capacitance and the broadening of the potential window of operation of these systems. In recent years, sophisticated surface design and engineering of hierarchical hybrid nanostructures has facilitated significant improvements in the specific and volumetric storage capabilities of supercapacitors. These nanostructured electrodes exhibit higher surface areas for ion adsorption and reduced ion diffusion lengths for the electrolyte ions. Significant advances have also been achieved in broadening the electrochemical window of operation of these systems, as realized via the development of asymmetric two-electrode cells consisting of nanocomposite positive and negative electrodes with complementary electrochemical windows, which operate in environmentally benign aqueous media. We provide an overview of the diverse approaches, in terms of chemistry and nanoscale architecture, employed recently for the development of asymmetric supercapacitors of improved electrochemical performance. PMID:25711524

  11. Printed-Compliant Electrochemical Systems

    NASA Astrophysics Data System (ADS)

    Gaikwad, Abhinav Machhindra

    Compliant electronic devices such as health monitoring tags, wearable electronics, fabricated using add-on printing techniques or by patterning traditional silicon based electronics in ultrathin format, enable them to flex, stretch and twist without any noticeable change in performance. These devices require a power source---a primary or secondary battery---to power the electronics. Traditional forms of batteries are bulky and negate the advantages of this new class of devices. Herein, I investigate various printing techniques and architectures that enable compliant batteries and study the performance of such batteries under mechanical deformations. Firstly, this dissertation investigates electrochemical-mechanical performance of a dispenser printed micro-battery using a microfluidic cell. Nanoparticulate silver ink was printed and cured to form silver electrodes, which was charged in-situ to form a silver-zinc battery. The electrochemical performance of the silver-zinc micro-battery was similar to macro-sized batteries. The shear stress generated by flow of electrolyte over the electrode was used to emulate the shear stress generated during flexing and was used as a tool to study the shear strength of the silver electrode at different state of charge. The dissertation then investigates supported architecture as a reinforcement to maintain the performance of the battery under strain. We demonstrate a highly flexible Zn-MnO2 alkalinebattery by embedding the electrochemically active particles in a mesh support. The mesh support absorbs the stresses generated during flexing. A Similar principle was used to make a stretchable battery. The backbone of the stretchable electrode was a stretchable fabric with silver-coated fibers weaved through a rubber network, which served as the current collector. The fabric was coated with Zn and MnO2 to form a stretchable electrode. Due to the weave architecture the electrode could stretch by 100% without any loss is contact between

  12. Electrochemical cell for rebalancing REDOX flow system

    NASA Technical Reports Server (NTRS)

    Thaller, L. H. (Inventor)

    1979-01-01

    An electrically rechargeable REDOX cell or battery system including one of more rebalancing cells is described. Each rebalancing cell is divided into two chambers by an ion permeable membrane. The first chamber is fed with gaseous hydrogen and a cathode fluid which is circulated through the cathode chamber of the REDOX cell is also passed through the second chamber of the rebalancing cell. Electrochemical reactions take place on the surface of insert electrodes in the first and second chambers to rebalance the electrochemical capacity of the anode and cathode fluids of the REDOX system.

  13. An electrochemical rebalance cell for Redox systems

    NASA Technical Reports Server (NTRS)

    Acevedo, J. C.; Stalnaker, D. K.

    1983-01-01

    An electrochemical rebalance cell for maintaining electrochemical balance, at the system level, of the acidified aqueous iron chloride and chromium chloride reactant solutions in the redox energy storage system was constructed and evaluated. The electrochemical reaction for the cathode is Fe(+3) + e(-) yields Fe(+2), and that for the anode is 1/2H2 yields H(+) + e(-). The iron (carbon felt) electrode and the hydrogen (platinized carbon) electrode are separated by an anion exchange membrane. The performance of the rebalance cell is discussed as well as the assembly of a single rebalance cell and multicell stacks. Various cell configurations were tested and the results are presented and discussed. The rebalance cell was also used to demonstrate its ability, as a preparative tool, for making high purity solutions of soluble reduced metal ionic species. Preparations of titanium, copper, vanadium and chromium ions in acidified solutions were evaluated.

  14. Program (systems) engineering

    NASA Technical Reports Server (NTRS)

    Baroff, Lynn E.; Easter, Robert W.; Pomphrey, Richard B.

    2004-01-01

    Program Systems Engineering applies the principles of Systems Engineering at the program level. Space programs are composed of interrelated elements which can include collections of projects, advanced technologies, information systems, etc. Some program elements are outside traditional engineering's physical systems, such as education and public outreach, public relations, resource flow, and interactions within the political environments.

  15. NASA Systems Engineering Handbook

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; Mcduffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

    1995-01-01

    This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive. Superseded by: NASA/SP-2007-6105 Rev 1 (20080008301).

  16. Gas permeable electrode for electrochemical system

    DOEpatents

    Ludwig, Frank A.; Townsend, Carl W.

    1989-01-01

    An electrode apparatus adapted for use in electrochemical systems having an anode compartment and a cathode compartment in which gas and ions are produced and consumed in the compartments during generation of electrical current. The electrode apparatus includes a membrane for separating the anode compartment from the cathode compartment wherein the membrane is permeable to both ions and gas. The cathode and anode for the assembly are provided on opposite sides of the membrane. During use of the membrane-electrode apparatus in electrochemical cells, the gas and ions generated at the cathode or anode migrate through the membrane to provide efficient transfer of gas and ions between the anode and cathode compartments.

  17. Pore size engineering applied to starved electrochemical cells and batteries

    NASA Technical Reports Server (NTRS)

    Abbey, K. M.; Thaller, L. H.

    1982-01-01

    To maximize performance in starved, multiplate cells, the cell design should rely on techniques which widen the volume tolerance characteristics. These involve engineering capillary pressure differences between the components of an electrochemical cell and using these forces to promote redistribution of electrolyte to the desired optimum values. This can be implemented in practice by prescribing pore size distributions for porous back-up plates, reservoirs, and electrodes. In addition, electrolyte volume management can be controlled by incorporating different pore size distributions into the separator. In a nickel/hydrogen cell, the separator must contain pores similar in size to the small pores of both the nickel and hydrogen electrodes in order to maintain an optimum conductive path for the electrolyte. The pore size distributions of all components should overlap in such a way as to prevent drying of the separator and/or flooding of the hydrogen electrode.

  18. 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. 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. As part of the NASA Technical Standards Program activities, engineering lessons learned datasets have been identified from a number of sources. These are being searched and screened for those having a relation to Technical Standards. This paper will address some of these Systems Engineering Lessons Learned and how they are being related to Technical Standards within the NASA Technical Standards Program, including linking to the Agency's Interactive Engineering Discipline Training Courses and the life cycle for a flight vehicle development program.

  19. Electrochemical air revitalization system optimization investigation

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Schubert, F. H.; Hallick, T. M.

    1975-01-01

    A program to characterize a Breadboard of an Electrochemical Air Revitalization System (BEARS) was successfully completed. The BEARS is composed of three components: (1) a water vapor electrolysis module (WVEM) for O2 production and partial humidity control, (2) an electrochemical depolarized carbon dioxide concentrator module (EDCM) for CO2 control, and (3) a power-sharing controller, designed to utilize the power produced by the EDCM to partially offset the WVEM power requirements. It is concluded from the results of this work that the concept of electrochemical air revitalization with power-sharing is a viable solution to the problem of providing a localized topping force for O2 generation, CO2 removal and partial humidity control aboard manned spacecraft. Continued development of the EARS concept is recommended, applying the operational experience and limits identified during the BEARS program to testing of a one-man capacity system and toward the development of advanced system controls to optimize EARS operation for given interfaces and requirements. Successful completion of this development will produce timely technology necessary to plan future advanced environmental control and life support system programs and experiments.

  20. Electrochemical sensor/detector system and method

    DOEpatents

    Glass, Robert S.; Perone, Sam P.; Ciarlo, Dino R.; Kimmons, James F.

    1992-01-01

    An electrochemical detection system is described comprising in combination: (a) a multielement, microelectrode array detector containing means for acquiring a plurality of signals; (b) electronic means for receiving said signals and converting said signals into a readout or display providing information with respect to the nature and concentration of elements present in a solution being tested. Also described is the means of making the above described microelectrode detector.

  1. Electrochemical sensor/detector system and method

    DOEpatents

    Glass, Robert S.; Perone, Sam P.; Ciarlo, Dino R.; Kimmons, James F.

    1994-01-01

    An electrochemical detection system is described comprising in combination: (a) a multielement, microelectrode array detector containing means for acquiring a plurality of signals; (b) electronic means for receiving said signals and converting said signals into a readout or display providing information with respect to the nature and concentration of elements present in a solution being tested. Also described is the means of making the above described microelectrode detector.

  2. Electrochemical sensor/detector system and method

    SciTech Connect

    Glass, R.S.; Perone, S.P.; Ciarlo, D.R.; Kimmons, J.F.

    1992-12-31

    An electrochemical detection system is described comprising in combination: (a) a multielement, microelectrode array detector containing means for acquiring a plurality of signals; (b) electronic means for receiving said signals and converting said signals into a readout or display providing information with respect to the nature and concentration of elements present in a solution being tested. Also described is the means of making the above described microelectrode detector.

  3. Engineering nanomaterials with a combined electrochemical and molecular biomimetic approach

    NASA Astrophysics Data System (ADS)

    Dai, Haixia

    Biocomposite materials, such as bones, teeth, and shells, are created using mild aqueous solution-based processes near room temperature. Proteins add flexibility to these processes by facilitating the nucleation, growth, and ordering of specific inorganic materials into hierarchical structures. We aim to develop a biomimetic strategy for engineering technologically relevant inorganic materials with controlled compositions and structures, as Nature does, using proteins to orchestrate material formation and assembly. This approach involves three basic steps: (i) preparation of inorganic substrates compatible with combinatorial polypeptide screening; (ii) identification of inorganic-binding polypeptides and their engineering into inorganic-binding proteins; and (iii) protein-mediated inorganic nucleation and organization. Cuprous oxide (Cu2O), a p-type semiconductor, has been used to demonstrate all three steps. Zinc oxide (ZnO), an n-type semiconductor, has been used to show the generality of selected steps. Step (i), preparation of high quality inorganic substrates to select inorganic-binding polypeptides, was accomplished using electrochemical microfabrication to grow and pattern Cu2O and ZnO. Raman spectroscopy and x-ray photoelectron spectroscopy were used to verify phase purity and compositional stability of these surfaces during polypeptide screening. Step (ii), accomplished in collaboration with personnel in Prof Baneyx' lab at the University of Washington, involved incubating the inorganic substrates with the FliTrx(TM) random peptide library to identify cysteine-constrained dodecapeptides that bind the targeted inorganic. Insertion of a Cu2O-binding dodecapeptide into the DNA-binding protein TraI endowed the engineered TraI with strong affinity for Cu2O (Kd ≈ 10 -8 M). Finally, step (iii) involved nonequilibrium synthesis and organization of Cu2O nanoparticles, taking advantage of the inorganic and DNA recognition properties of the engineered TraI. The

  4. Gas permeable electrode for electrochemical system

    DOEpatents

    Ludwig, F.A.; Townsend, C.W.

    1989-09-12

    An electrode apparatus is described which is adapted for use in electrochemical systems having an anode compartment and a cathode compartment in which gas and ions are produced and consumed in the compartments during generation of electrical current. The electrode apparatus includes a membrane for separating the anode compartment from the cathode compartment wherein the membrane is permeable to both ions and gas. The cathode and anode for the assembly are provided on opposite sides of the membrane. During use of the membrane-electrode apparatus in electrochemical cells, the gas and ions generated at the cathode or anode migrate through the membrane to provide efficient transfer of gas and ions between the anode and cathode compartments. 3 figs.

  5. Review of thermally regenerative electrochemical systems. Volume I. Synopsis and executive summary

    SciTech Connect

    Chum, H. L.; Osteryoung, R. A.

    1980-08-01

    Thermally regenerative electrochemical systems (TRES) are closed systems that convert heat into electricity in an electrochemical heat engine that is Carnot cycle limited in efficiency. Past and present work on such systems is reviewed. Two broad classes of TRES are based on the types of energy inputs required for regeneration: thermal alone and coupled thermal and electrolytic. The thermal regeneration alone encompasses electrochemical systems (galvanic or fuel cells) in which one or more products are formed. The regeneration can be performed in single or multiple steps. The compounds include metal hydrides, halides, oxides, chalcogenides, and alloys or bimetallic systems. The coupled thermal and electrolytic regeneration encompasses electrochemical systems (galvanic or fuel cells) regenerated by electrolysis at a different temperature or different pressure. Examples include metal halides and water. Thermogalvanic or nonisothermal cells are included in this category. Also included are electrochemical engines in which the working electroactive fluid is isothermally expanded through an electrolyte. TRES cover temperature ranges from about 20/sup 0/C to 1000/sup 0/C. Engines with power outputs of 0.1 mW/cm/sup 2/ to 1 W/cm/sup 2/ have been demonstrated. Recommendations are made of areas of research in science and engineering that would have long-range benefit to a TRES program.

  6. Progress in electrochemical storage for battery systems

    NASA Technical Reports Server (NTRS)

    Ford, F. E.; Hennigan, T. J.; Palandati, C. F.; Cohn, E.

    1972-01-01

    Efforts to improve electrochemical systems for space use relate to: (1) improvement of conventional systems; (2) development of fuel cells to practical power systems; and (3) a search for new systems that provide gains in energy density but offer comparable life and performance as conventional systems. Improvements in sealed conventional systems resulted in the areas of materials, charge control methods, cell operations and battery control, and specific process controls required during cell manufacture. Fuel-cell systems have been developed for spacecraft but the use of these power plants is limited. For present and planned flights, nickel-cadmium, silver-zinc, and silver-cadmium systems will be used. Improvements in nickel-cadmium batteries have been applied in medical and commercial areas.

  7. Electrohydrodynamic Flows in Electrochemical Systems

    NASA Technical Reports Server (NTRS)

    Saville, D. A.

    2005-01-01

    Recent studies have established a new class of assembly processes with colloidal suspensions. Particles are driven together to form large crystalline structures in both dc and ac fields. The current work centers on this new class of flows in ac fields. In the research carried out under the current award, it was established that: (i) Small colloidal particles crystallize near an electrode due to electrohydrodynamic flows induced by an sinusoidally varying applied potential. (ii) These flows originate due to disturbances in the electrode polarization layer arising from the presence of the particles. Inasmuch as the charge and the field strength both scale on the applied field, the flows are proportional to the square of the applied voltage. (iii) Suspensions of two different sorts of particles can be crystallized and will form well-ordered binary crystals. (iv) At high frequencies the EHD flows die out. Thus, with a homogeneous system the particles become widely spaced due to dipolar repulsion. With a binary suspension, however, the particles may become attractive due to dipolar attraction arising from differences in electrokinetic dipoles. Consequently binary crystals form at both high and low frequencies.

  8. Nuclear propulsion systems engineering

    SciTech Connect

    Madsen, W.W.; Neuman, J.E.: Van Haaften, D.H.

    1992-12-31

    The Nuclear Energy for Rocket Vehicle Application (NERVA) program of the 1960`s and early 1970`s was dramatically successful, with no major failures during the entire testing program. This success was due in large part to the successful development of a systems engineering process. Systems engineering, properly implemented, involves all aspects of the system design and operation, and leads to optimization of theentire system: cost, schedule, performance, safety, reliability, function, requirements, etc. The process must be incorporated from the very first and continued to project completion. This paper will discuss major aspects of the NERVA systems engineering effort, and consider the implications for current nuclear propulsion efforts.

  9. Nuclear propulsion systems engineering

    SciTech Connect

    Madsen, W.W.; Neuman, J.E.: Van Haaften, D.H.

    1992-01-01

    The Nuclear Energy for Rocket Vehicle Application (NERVA) program of the 1960's and early 1970's was dramatically successful, with no major failures during the entire testing program. This success was due in large part to the successful development of a systems engineering process. Systems engineering, properly implemented, involves all aspects of the system design and operation, and leads to optimization of theentire system: cost, schedule, performance, safety, reliability, function, requirements, etc. The process must be incorporated from the very first and continued to project completion. This paper will discuss major aspects of the NERVA systems engineering effort, and consider the implications for current nuclear propulsion efforts.

  10. Systems engineering management plans.

    SciTech Connect

    Rodriguez, Tamara S.

    2009-10-01

    The Systems Engineering Management Plan (SEMP) is a comprehensive and effective tool used to assist in the management of systems engineering efforts. It is intended to guide the work of all those involved in the project. The SEMP is comprised of three main sections: technical project planning and control, systems engineering process, and engineering specialty integration. The contents of each section must be tailored to the specific effort. A model outline and example SEMP are provided. The target audience is those who are familiar with the systems engineering approach and who have an interest in employing the SEMP as a tool for systems management. The goal of this document is to provide the reader with an appreciation for the use and importance of the SEMP, as well as provide a framework that can be used to create the management plan.

  11. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    PubMed

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field. PMID:26579616

  12. Developing Data System Engineers

    NASA Astrophysics Data System (ADS)

    Behnke, J.; Byrnes, J. B.; Kobler, B.

    2011-12-01

    In the early days of general computer systems for science data processing, staff members working on NASA's data systems would most often be hired as mathematicians. Computer engineering was very often filled by those with electrical engineering degrees. Today, the Goddard Space Flight Center has special position descriptions for data scientists or as they are more commonly called: data systems engineers. These staff members are required to have very diverse skills, hence the need for a generalized position description. There is always a need for data systems engineers to develop, maintain and operate the complex data systems for Earth and space science missions. Today's data systems engineers however are not just mathematicians, they are computer programmers, GIS experts, software engineers, visualization experts, etc... They represent many different degree fields. To put together distributed systems like the NASA Earth Observing Data and Information System (EOSDIS), staff are required from many different fields. Sometimes, the skilled professional is not available and must be developed in-house. This paper will address the various skills and jobs for data systems engineers at NASA. Further it explores how to develop staff to become data scientists.

  13. What is systems engineering?

    SciTech Connect

    Bahill, A.T.

    1995-08-01

    Systems Engineering is an interdisciplinary process that ensures that the customers` needs are satisfied throughout a system`s entire life cycle. This process includes: understanding customer needs; stating the problem; specifying requirements; defining performance and cost measures, prescribing tests, validating requirements, conducting design reviews, exploring alternative concepts, sensitivity analyses, functional decomposition, system design, designing and managing interfaces, system integration, total system test, configuration management, risk management, reliability analysis; total quality management; project management; and documentation. Material for this paper was gathered from senior Systems Engineers at Sandia National Laboratories.

  14. Rotary engine cooling system

    NASA Technical Reports Server (NTRS)

    Jones, Charles (Inventor); Gigon, Richard M. (Inventor); Blum, Edward J. (Inventor)

    1985-01-01

    A rotary engine has a substantially trochoidal-shaped housing cavity in which a rotor planetates. A cooling system for the engine directs coolant along a single series path consisting of series connected groups of passages. Coolant enters near the intake port, passes downwardly and axially through the cooler regions of the engine, then passes upwardly and axially through the hotter regions. By first flowing through the coolest regions, coolant pressure is reduced, thus reducing the saturation temperature of the coolant and thereby enhancing the nucleate boiling heat transfer mechanism which predominates in the high heat flux region of the engine during high power level operation.

  15. Aircraft Engine Systems

    NASA Technical Reports Server (NTRS)

    Veres, Joseph

    2001-01-01

    This report outlines the detailed simulation of Aircraft Turbofan Engine. The objectives were to develop a detailed flow model of a full turbofan engine that runs on parallel workstation clusters overnight and to develop an integrated system of codes for combustor design and analysis to enable significant reduction in design time and cost. The model will initially simulate the 3-D flow in the primary flow path including the flow and chemistry in the combustor, and ultimately result in a multidisciplinary model of the engine. The overnight 3-D simulation capability of the primary flow path in a complete engine will enable significant reduction in the design and development time of gas turbine engines. In addition, the NPSS (Numerical Propulsion System Simulation) multidisciplinary integration and analysis are discussed.

  16. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  17. 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

  18. Electrochemical Technology for Oxygen Removal and Measurement in the CELSS Test Facility, Engineering Development Unit

    NASA Technical Reports Server (NTRS)

    Drews, Michael E.; Covington, Al (Technical Monitor)

    1994-01-01

    The Life Support Flight Program is evaluating regenerative technologies, including those that utilize higher plants, as a means to reduce resupply over long duration space missions. Constructed to assist in the evaluation process is the CELSS Test Facility Engineering Development Unit (CTF-EDU) an environmentally closed (less than 1% mass and thermal leakage) technology test bed. This ground based fully functional prototype is currently configured to support crop growth, utilizing the power, volume and mass resources allocated for two space station racks. Sub-system technologies were selected considering their impact on available resources, their ability to minimize integration issues, and their degree of modularity. Gas specific mass handling is a key sub-system technology for both biological and physical/chemical life support technologies. The CTF-EDU requires such a system to accommodate non-linear oxygen production from crops, by enabling the control system to change and sustain partial pressure set points in the growth volume. Electrochemical cells are one of the technologies that were examined for oxygen handling in the CTF-EDU. They have been additionally considered to meet other regenerative life support functions, such as oxygen generation, the production of potable water from composite waste streams, and for having the potential to integrate life support functions with those of propulsion and energy storage. An oxygen removal system based on an electrochemical cell was chosen for the EDU due to it's low power, volume and mass requirements (10W, 0.000027 cu m, 4.5 kg) and because of the minimal number of integration considerations. Unlike it's competitors, the system doesn't require post treatments of its byproducts, or heat and power intensive regenerations, that also mandate system redundancy or cycling. The EDUs oxygen removal system only requires two resources, which are already essential to controlled plant growth: electricity and water. Additionally

  19. The use of engineered protein materials in electrochemical devices.

    PubMed

    Renner, Julie N; Minteer, Shelley D

    2016-05-01

    Bioelectrochemical technologies have an important and growing role in healthcare, with applications in sensing and diagnostics, as well as the potential to be used as implantable power sources and be integrated with automated drug delivery systems. Challenges associated with enzyme-based electrodes include low current density and short functional lifetimes. Protein engineering is emerging as a powerful tool to overcome these issues. By taking advantage of the ability to precisely define protein sequences, electrodes can be organized into high performing structures, and enable the next generation of medical devices. PMID:27188516

  20. Systems engineering and analysis

    SciTech Connect

    Blanchard, B.S.; Fabrycky, W.J.

    1981-01-01

    An introduction to systems is provided and tools for systems analysis are considered, taking into account system definitions and concepts, approaches for bringing systems into being, models in systems analysis, economic analysis techniques, mathematical modeling and optimization, probability and statistics, queuing theory and analysis, and control concepts and techniques. The system design process is discussed along with the design for operational feasibility, systems engineering management, and system design case studies. Attention is given to conceptual design, preliminary system design, detail design and development, system test and evaluation, design for reliability, design for maintainability, design for supportability, design for economic feasibility, communication system design, finite population system design, energy storage system design, and procurement-inventory system design.

  1. 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

  2. Electrochemical energy storage using PEM systems

    SciTech Connect

    Vanderborgh, N.E.; Hedstrom, J.C.; Huff, J.R.

    1991-01-01

    This paper gives the results of an engineering assessment for future, long-lived space power systems for extraterrestrial applications. Solar-based, regenerative fuel cell power plants formed from either alkaline or PEM components are the focus. Test results on advanced PEM fuel cell stack components are presented. 7 refs., 4 figs., 1 tab.

  3. Alternative Electrochemical Systems for Ozonation of Water

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C.; Murphy, Oliver J.

    2003-01-01

    Electrochemical systems that are especially well suited for the small-scale generation of ozone and ozonated water for local use have been invented. These systems can operate with very little maintenance, and the only inputs needed during operation are electric power and water. Ozonated water produced by these systems can be used in diverse industrial applications: A few examples include sterilization in the brewing industry, general disinfection, and treatment of sewage and recycled water. The basic principle of operation admits of several alternative system configurations. The heart of the system is a stack of electrolytic cells, each containing a proton-exchange membrane (which serves as a solid electrolyte) sandwiched between a catalytic anode and a catalytic cathode. Preferably, the proton-exchange membrane is made of a perfluorinated sulfonic acid polymer. During electrolysis, a mixture of O2 and O3 gases is generated at the anode and H2 is generated at the cathode. Some of the O3 generated at the anode becomes dissolved in the water. The proportion of O3 in the O2/O3 mixture can be maximized by the selection of suitable electrode materials and the use of a high overpotential. Although the proton-exchange membrane conducts protons, it does not conduct electrons. It is also impermeable by gases; consequently, it maintains separation between the O2/O3 mixture evolved at the anode and the H2 evolved at the cathode.

  4. Readings in Systems Engineering

    NASA Technical Reports Server (NTRS)

    Hoban, Francis T. (Editor); Lawbaugh, William M. (Editor)

    1993-01-01

    This present collection was inspired by seven papers prepared by the NASA Alumni League, illustrating the members' systems engineering experience. These papers make up the heart of this collection. We have supplemented them with papers describing industry processes and other governmental practices to illustrate the diversity of systems engineering as it is formulated and practiced. This is one discipline that clearly benefits from cross-fertilization and infusion of new ideas. There is also a wide variety of tools and techniques described herein, some standard and some unique.

  5. Electrochemical energy storage systems for solar thermal applications

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.; Frank, H.

    1980-01-01

    Existing and advanced electrochemical storage and inversion/conversion systems that may be used with terrestrial solar-thermal power systems are evaluated. The status, cost and performance of existing storage systems are assessed, and the cost, performance, and availability of advanced systems are projected. A prime consideration is the cost of delivered energy from plants utilizing electrochemical storage. Results indicate that the five most attractive electrochemical storage systems are the: iron-chromium redox (NASA LeRC), zinc-bromine (Exxon), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (EDA).

  6. NASA Systems Engineering Handbook

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This handbook is intended to provide general guidance and information on systems engineering that will be useful to the NASA community. It provides a generic description of Systems Engineering (SE) as it should be applied throughout NASA. A goal of the handbook is to increase awareness and consistency across the Agency and advance the practice of SE. This handbook provides perspectives relevant to NASA and data particular to NASA. The coverage in this handbook is limited to general concepts and generic descriptions of processes, tools, and techniques. It provides information on systems engineering best practices and pitfalls to avoid. There are many Center-specific handbooks and directives as well as textbooks that can be consulted for in-depth tutorials. This handbook describes systems engineering as it should be applied to the development and implementation of large and small NASA programs and projects. NASA has defined different life cycles that specifically address the major project categories, or product lines, which are: Flight Systems and Ground Support (FS&GS), Research and Technology (R&T), Construction of Facilities (CoF), and Environmental Compliance and Restoration (ECR). The technical content of the handbook provides systems engineering best practices that should be incorporated into all NASA product lines. (Check the NASA On-Line Directives Information System (NODIS) electronic document library for applicable NASA directives on topics such as product lines.) For simplicity this handbook uses the FS&GS product line as an example. The specifics of FS&GS can be seen in the description of the life cycle and the details of the milestone reviews. Each product line will vary in these two areas; therefore, the reader should refer to the applicable NASA procedural requirements for the specific requirements for their life cycle and reviews. The engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and

  7. Electrochemical engineering of hollow nanoarchitectures: pulse/step anodization (Si, Al, Ti) and their applications.

    PubMed

    Wang, Kaiying; Liu, Guohua; Hoivik, Nils; Johannessen, Erik; Jakobsen, Henrik

    2014-03-01

    Hollow nanoarchitectured materials with straight channels play a crucial role in the fields of renewable energy, environment and biotechnology due to their one-dimensional morphology and extraordinary properties. The current challenge is the difficulty on tailoring hollow nanoarchitectures with well-controlled morphology at a relatively low cost. As a conventional technique, electrochemistry exhibits its unique advantage on machining nanostructures. In this review, we present the progress of electrochemistry as a valuable tool in construction of novel hollow nanoarchitectures through pulse/step anodization, such as surface pre-texturing, modulated, branched and multilayered pore architectures, and free-standing membranes. Basic principles for electrochemical engineering of mono- or multi-ordered nanostructures as well as free-standing membranes are extracted from specific examples (i.e. porous silicon, aluminum and titanium oxide). The potential of such nanoarchitectures are further demonstrated for the applications of photovoltaics, water splitting, organic degradation, nanostructure templates, biosensors and drug release. The electrochemical techniques provide a powerful approach to produce nanostructures with morphological complexity, which could have far-reaching implications in the design of future nanoscale systems. PMID:24292021

  8. Rocket engine condition monitoring system

    SciTech Connect

    Hagar, S.K.; Alcock, J.F.

    1989-01-01

    It is expected that the Rocket Engine Condition Monitoring System (RECMS) program will define engine monitoring technologies and an integration approach which can be applied to engine development in support of advanced launch system objectives. The RECMS program approaches engine monitoring as a system which is fully integrated with the engine controller, vehicle monitoring system, and ground processing systems to ensure mission success in addition to engine reliability. The system components are monitored through health and performance sensors; they are analyzed with the diagnostic and prognostic algorithms and demonstrated by system testing with hardware from other advanced development programs.

  9. Parallel electrochemical treatment system and application for identifying acid-stable oxygen evolution electrocatalysts.

    PubMed

    Jones, Ryan J R; Shinde, Aniketa; Guevarra, Dan; Xiang, Chengxiang; Haber, Joel A; Jin, Jian; Gregoire, John M

    2015-02-01

    Many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. Imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts in the parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operation of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed-metal oxides to oxygen evolution conditions in 1 M sulfuric acid for 2 h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements. PMID:25561243

  10. Engineering new aptamer geometries for electrochemical aptamer-based sensors

    NASA Astrophysics Data System (ADS)

    White, Ryan J.; Plaxco, Kevin W.

    2009-05-01

    Electrochemical aptamer-based sensors (E-AB sensors) represent a promising new approach to the detection of small molecules. E-AB sensors comprise an aptamer that is attached at one end to an electrode surface. The distal end of the aptamer probed is modified with an electroactive redox marker for signal transduction. Herein we report on the optimization of a cocaine-detecting E-AB sensor via optimization of the geometry of the aptamer. We explore two new aptamer architectures, one in which we concatenate three cocaine aptamers into a poly-aptamer and a second in which we divide the cocaine aptamer into pieces connected via an unstructured, 60-thymine linker. Both of these structures are designed such that the reporting redox tag will be located farther from the electrode in the unfolded, target-free conformation. Consistent with this, we find that signal gains of these two constructs are two to three times higher than that of the original E-AB architecture. Likewise all three architectures are selective enough to deploy directly in complex sample matrices, such as undiluted whole blood, with all three sensors successfully detecting the presence of cocaine. The findings in this ongoing study should be of value in future efforts to optimize the signaling of electrochemical aptamer-based sensors.

  11. Separator-spacer for electrochemical systems

    DOEpatents

    Grimes, Patrick G.; Einstein, Harry; Newby, Kenneth R.; Bellows, Richard J.

    1983-08-02

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  12. Looking ahead in systems engineering

    NASA Technical Reports Server (NTRS)

    Feigenbaum, Donald S.

    1966-01-01

    Five areas that are discussed in this paper are: (1) the technological characteristics of systems engineering; (2) the analytical techniques that are giving modern systems work its capability and power; (3) the management, economics, and effectiveness dimensions that now frame the modern systems field; (4) systems engineering's future impact upon automation, computerization and managerial decision-making in industry - and upon aerospace and weapons systems in government and the military; and (5) modern systems engineering's partnership with modern quality control and reliability.

  13. Engineering PQQ-glucose dehydrogenase into an allosteric electrochemical Ca(2+) sensor.

    PubMed

    Guo, Zhong; Johnston, Wayne A; Stein, Viktor; Kalimuthu, Palraj; Perez-Alcala, Siro; Bernhardt, Paul V; Alexandrov, Kirill

    2016-01-11

    Electrochemical biosensors convert biological events to an electrical current. To date most electrochemical biosensors exploit activities of naturally occurring enzymes. Here we demonstrated that insertion of a calmodulin domain into the redox enzyme PQQ-glucose dehydrogenase resulted in a selective Ca(2+) biosensor that could be used to rapidly measure Ca(2+) concentrations in human biological fluids. We were able to convert a point-of-care glucometer into Ca(2+) monitor by refurbishing it with the developed biosensor. We propose that similar engineering strategies may be used to create highly specific electrochemical biosensors to other analytes. Compatibility with cheap and ubiquitous amperometric detectors is expected to accelerate progression of these biosensors into clinical applications. PMID:26528736

  14. Multielectrode Teflon electrochemical nanocatalyst investigation system

    PubMed Central

    Hodnik, Nejc

    2015-01-01

    The most common approach in the search for the optimal low temperature fuel cell catalyst remains “trial and error”. Therefore, large numbers of different potential catalytic materials need to be screened. The well-established and most commonly used method for testing catalytic electrochemical activity under well-defined hydrodynamics is still thin film rotating disc electrode (TF-RDE). Typically this method is very time consuming and is subjected to impurity problems. In order to avoid these issues a new multielectrode electrochemical cell design is presented, where 8 different electrocatalysts can be measured simultaneously at identical conditions. The major advantages over TF-RDE method are: • Faster catalyst screening times. • Greater impurity tolerance. • The option of internal standard. PMID:26150990

  15. Deterministic analysis of processes at corroding metal surfaces and the study of electrochemical noise in these systems

    SciTech Connect

    Latanision, R.M.

    1990-12-01

    Electrochemical corrosion is pervasive in virtually all engineering systems and in virtually all industrial circumstances. Although engineers now understand how to design systems to minimize corrosion in many instances, many fundamental questions remain poorly understood and, therefore, the development of corrosion control strategies is based more on empiricism than on a deep understanding of the processes by which metals corrode in electrolytes. Fluctuations in potential, or current, in electrochemical systems have been observed for many years. To date, all investigations of this phenomenon have utilized non-deterministic analyses. In this work it is proposed to study electrochemical noise from a deterministic viewpoint by comparison of experimental parameters, such as first and second order moments (non-deterministic), with computer simulation of corrosion at metal surfaces. In this way it is proposed to analyze the origins of these fluctuations and to elucidate the relationship between these fluctuations and kinetic parameters associated with metal dissolution and cathodic reduction reactions. This research program addresses in essence two areas of interest: (a) computer modeling of corrosion processes in order to study the electrochemical processes on an atomistic scale, and (b) experimental investigations of fluctuations in electrochemical systems and correlation of experimental results with computer modeling. In effect, the noise generated by mathematical modeling will be analyzed and compared to experimental noise in electrochemical systems. 1 fig.

  16. Engineering the LISA Project: Systems Engineering Challenges

    NASA Technical Reports Server (NTRS)

    Evans, Jordan P.

    2006-01-01

    The Laser Interferometer Space Antenna (LISA) is a joint NASA/ESA mission to detect and measure gravitational waves with periods from 1 s to 10000 s. The systems engineering challenges of developing a giant interferometer, 5 million kilometers on a side, an: numerous. Some of the key challenges are presented in this paper. The organizational challenges imposed by sharing the engineering function between three centers (ESA ESTEC, NASA GSFC, and JPL) across nine time zones are addressed. The issues and approaches to allocation of the acceleration noise and measurement sensitivity budget terms across a traditionally decomposed system are discussed. Additionally, using LISA to detect gravitational waves for the first time presents significant data analysis challenges, many of which drive the project system design. The approach to understanding the implications of science data analysis on the system is also addressed.

  17. Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

    NASA Technical Reports Server (NTRS)

    Hall, Phil; Whitfield, Susan

    2011-01-01

    This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

  18. Proceedings of the 31. intersociety energy conversion engineering conference. Volume 2: Conversion technologies, electro-chemical technologies, Stirling engines, thermal management

    SciTech Connect

    Chetty, P.R.K.; Jackson, W.D.; Dicks, E.B.

    1996-12-31

    The 148 papers contained in Volume 2 are arranged topically as follows -- (A) Conversion Technologies: Superconductivity applications; Advanced cycles; Heat engines; Heat pumps; Combustion and cogeneration; Advanced nuclear reactors; Fusion Power reactors; Magnetohydrodynamics; Alkali metal thermal to electric conversion; Thermoelectrics; Thermionic conversion; Thermophotovoltaics; Advances in electric machinery; and Sorption technologies; (B) Electrochemical Technologies: Terrestrial fuel cell technology; and Batteries for terrestrial power; (C) Stirling Engines: Stirling machine analysis; Stirling machine development and testing; and Stirling component analysis and testing; (D) Thermal Management: Cryogenic heat transfer; Electronic components and power systems; Environmental control systems; Heat pipes; Numeric analysis and code verification; and Two phase heat and mass transfer. Papers within the scope of the data base have been processed separately.

  19. Chemical imaging of biological systems with the scanning electrochemical microscope.

    PubMed

    Gyurcsányi, Róbert E; Jágerszki, Gyula; Kiss, Gergely; Tóth, Klára

    2004-06-01

    A brief overview on recent advances in the application of scanning electrochemical microscopy (SECM) to the investigation of biological systems is presented. Special emphasis is given to the mapping of local enzyme activity by SECM, which is exemplified by relevant original systems. PMID:15110274

  20. NASA System Engineering Design Process

    NASA Technical Reports Server (NTRS)

    Roman, Jose

    2011-01-01

    This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.

  1. Stirling engine heating system

    SciTech Connect

    Johansson, L.N.; Houtman, W.H.; Percival, W.H.

    1988-06-28

    A hot gas engine is described wherein a working gas flows back and forth in a closed path between a relatively cooler compression cylinder side of the engine and a relatively hotter expansion cylinder side of the engine and the path contains means including a heat source and a heat sink acting upon the gas in cooperation with the compression and expansion cylinders to cause the gas to execute a thermodynamic cycle wherein useful mechanical output power is developed by the engine, the improvement in the heat source which comprises a plurality of individual tubes each forming a portion of the closed path for the working gas.

  2. Automatic engine control system

    SciTech Connect

    Geary, W.C.; Mirsaiidi, M.V.; Redfern, T.; Wolfe, D.W.

    1986-01-14

    This patent describes an automatic control circuit for an internal combustion engine and clutch assembly. One component of this circuit is a timer for determining the time the engine is allowed to run and the clutch is engaged and a second period of time when the clutch is automatically disengaged. Associated with the timer is a starter means to start the engine during the first time period and a clutch actuating mechanism for engaging the clutch near the first time period initiation after the starter starts the engine. An engine shut down and clutch disengagement mechanism is also responsive to the first timer. The patent then goes on to describe a supplemental timer mechanism for determining a third and fourth period of time within the second time period such that the third period being when the engine is shut off and the fourth period being when the engine runs with clutch disengaged. The starter mechanism is responsive to the supplemental timer to start the engine at the beginning of the fourth period. A shut down means stops the engine at the beginning of the third period in response to the timer.

  3. Intelligent Engine Systems: Bearing System

    NASA Technical Reports Server (NTRS)

    Singh, Arnant P.

    2008-01-01

    The overall requirements necessary for sensing bearing distress and the related criteria to select a particular rotating sensor were established during the phase I. The current phase II efforts performed studies to evaluate the Robustness and Durability Enhancement of the rotating sensors, and to design, and develop the Built-in Telemetry System concepts for an aircraft engine differential sump. A generic test vehicle that can test the proposed bearing diagnostic system was designed, developed, and built. The Timken Company, who also assisted with testing the GE concept of using rotating sensors for the differential bearing diagnostics during previous phase, was selected as a subcontractor to assist General Electric (GE) for the design, and procurement of the test vehicle. A purchase order was prepared to define the different sub-tasks, and deliverables for this task. The University of Akron was selected to provide the necessary support for installing, and integrating the test vehicle with their newly designed test facility capable of simulating the operating environment for the planned testing. The planned testing with good and damaged bearings will be on hold pending further continuation of this effort during next phase.

  4. Microfluidic systems for electrochemical and biological studies

    SciTech Connect

    Ackler, H., LLNL

    1998-05-01

    Microfluidic devices with microelectrodes have the potential to enable studies of phenomena at size scales where behavior may be dominated by different mechanisms than at macroscales. Through our work developing microfluidic devices for dielectrophoretic separation and sensing of cells and particles, we have fabricated devices from which general or more specialized research devices may be derived. Fluid channels from 80 {micro}m wide X 20 {micro}m deep to 1 mm wide to 200 {micro}m deep have been fabricated in glass, with lithographically patterned electrodes from 10 to 80 {micro}m wide on one or both sides on the channels and over topographies tens of microns in heights. the devices are designed to easily interface to electronic and fluidic interconnect packages that permit reuse of devices, rather than one-time use, crude glue-based methods. Such devices may be useful for many applications of interest to the electrochemical and biological community.

  5. System identification of jet engines

    SciTech Connect

    Sugiyama, N.

    2000-01-01

    System identification plays an important role in advanced control systems for jet engines, in which controls are performed adaptively using data from the actual engine and the identified engine. An identification technique for jet engine using the Constant Gain Extended Kalman Filter (CGEKF) is described. The filter is constructed for a two-spool turbofan engine. The CGEKF filter developed here can recognize parameter change in engine components and estimate unmeasurable variables over whole flight conditions. These capabilities are useful for an advanced Full Authority Digital Electric Control (FADEC). Effects of measurement noise and bias, effects of operating point and unpredicted performance change are discussed. Some experimental results using the actual engine are shown to evaluate the effectiveness of CGEKF filter.

  6. Systems engineering technology for networks

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The report summarizes research pursued within the Systems Engineering Design Laboratory at Virginia Polytechnic Institute and State University between May 16, 1993 and January 31, 1994. The project was proposed in cooperation with the Computational Science and Engineering Research Center at Howard University. Its purpose was to investigate emerging systems engineering tools and their applicability in analyzing the NASA Network Control Center (NCC) on the basis of metrics and measures.

  7. NASA systems engineering handbook. Draft

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Chamberlain, Robert G.; Aster, Robert; Bilardo, Vincent; Forsberg, Kevin; Hammond, Walter E.; Mooz, Harold; Polaski, Lou; Wade, Ron; Cassingham, Randy (Editor)

    1992-01-01

    This handbook is intended to provide information on systems engineering that will be useful to NASA system engineers, especially new ones. Its primary objective is to provide a generic description of systems engineering as it should be applied throughout NASA. Field Center Handbooks are encouraged to provide center-specific details of implementation. For NASA system engineers to choose to keep a copy of this handbook at their elbows, it must provide answers that cannot be easily found elsewhere. Consequently, it provides NASA-relevant perspectives and NASA-particular data. NASA management instructions (NMI's) are referenced when applicable. This handbook's secondary objective is to serve as a useful companion to all of the various courses in systems engineering that are being offered under NASA's auspices. The coverage of systems engineering is general to techniques, concepts, and generic descriptions of processes, tools, and techniques. It provides good systems engineering practices, and pitfalls to avoid. This handbook describes systems engineering as it should be applied to the development of major NASA product and producing systems.

  8. One-man electrochemical air revitalization system evaluation

    NASA Technical Reports Server (NTRS)

    Schbert, F. H.; Marshall, R. D.; Hallick, T. M.; Woods, R. R.

    1976-01-01

    A program to evaluate the performance of a one man capacity, self contained electrochemical air revitalization system was successfully completed. The technology readiness of this concept was demonstrated by characterizing the performance of this one man system over wide ranges in cabin atmospheric conditions. The electrochemical air revitalization system consists of a water vapor electrolysis module to generate oxygen from water vapor in the cabin air, and an electrochemical depolarized carbon dioxide concentrator module to remove carbon dioxide from the cabin air. A control/monitor instrumentation package that uses the electrochemical depolarized concentrator module power generated to partially offset the water vapor electrolysis module power requirements and various structural fluid routing components are also part of the system. The system was designed to meet the one man metabolic oxygen generation and carbon dioxide removal requirements, thereby controlling cabin partial pressure of oxygen at 22 kN/sq m and cabin pressure of carbon dioxide at 400 N/sq m over a wide range in cabin air relative humidity conditions.

  9. System safety engineering analysis handbook

    NASA Technical Reports Server (NTRS)

    Ijams, T. E.

    1972-01-01

    The basic requirements and guidelines for the preparation of System Safety Engineering Analysis are presented. The philosophy of System Safety and the various analytic methods available to the engineering profession are discussed. A text-book description of each of the methods is included.

  10. Automotive Stirling engine systems development

    NASA Technical Reports Server (NTRS)

    Richey, A. E.

    1984-01-01

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

  11. Possibilities for extremophilic microorganisms in microbial electrochemical systems

    PubMed Central

    Dopson, Mark; Ni, Gaofeng; Sleutels, Tom HJA

    2015-01-01

    Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems. PMID:26474966

  12. Possibilities for extremophilic microorganisms in microbial electrochemical systems.

    PubMed

    Dopson, Mark; Ni, Gaofeng; Sleutels, Tom H J A

    2016-03-01

    Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems. PMID:26474966

  13. Combined heat and power (cogeneration) plant based on renewable energy sources and electrochemical hydrogen systems

    NASA Astrophysics Data System (ADS)

    Grigor'ev, S. A.; Grigor'ev, A. S.; Kuleshov, N. V.; Fateev, V. N.; Kuleshov, V. N.

    2015-02-01

    The layout of a combined heat and power (cogeneration) plant based on renewable energy sources (RESs) and hydrogen electrochemical systems for the accumulation of energy via the direct and inverse conversion of the electrical energy from RESs into the chemical energy of hydrogen with the storage of the latter is described. Some efficient technical solutions on the use of electrochemical hydrogen systems in power engineering for the storage of energy with a cyclic energy conversion efficiency of more than 40% are proposed. It is shown that the storage of energy in the form of hydrogen is environmentally safe and considerably surpasses traditional accumulator batteries by its capacitance characteristics, being especially topical in the prolonged absence of energy supply from RESs, e.g., under the conditions of polar night and breathless weather. To provide the required heat consumption of an object during the peak period, it is proposed to burn some hydrogen in a boiler house.

  14. Engine systems and methods of operating an engine

    DOEpatents

    Scotto, Mark Vincent

    2015-08-25

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  15. Intelligent Engine Systems

    NASA Technical Reports Server (NTRS)

    Xie, Ming

    2008-01-01

    A high bypass jet engine fan case represents one of the largest, heaviest single components in an engine. In addition to supporting the inlet and providing the fan flowpath, the most critical function is the containment of a failed fan blade. In this development program, a lightweight, low-cost composite containment case with diagnostic capabilities was developed, fabricated, and tested. The fan case design, containment methods, and diagnostic concepts evaluated in the initial Propulsion 21 program were improved and scaled up to a full case design.

  16. Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems.

    PubMed

    Park, Min-Sik; Kim, Jeonghun; Kim, Ki Jae; Lee, Jong-Won; Kim, Jung Ho; Yamauchi, Yusuke

    2015-12-14

    Transition metal oxides possessing two kinds of metals (denoted as AxB3-xO4, which is generally defined as a spinel structure; A, B = Co, Ni, Zn, Mn, Fe, etc.), with stoichiometric or even non-stoichiometric compositions, have recently attracted great interest in electrochemical energy storage systems (ESSs). The spinel-type transition metal oxides exhibit outstanding electrochemical activity and stability, and thus, they can play a key role in realising cost-effective and environmentally friendly ESSs. Moreover, porous nanoarchitectures can offer a large number of electrochemically active sites and, at the same time, facilitate transport of charge carriers (electrons and ions) during energy storage reactions. In the design of spinel-type transition metal oxides for energy storage applications, therefore, nanostructural engineering is one of the most essential approaches to achieving high electrochemical performance in ESSs. In this perspective, we introduce spinel-type transition metal oxides with various transition metals and present recent research advances in material design of spinel-type transition metal oxides with tunable architectures (shape, porosity, and size) and compositions on the micro- and nano-scale. Furthermore, their technological applications as electrode materials for next-generation ESSs, including metal-air batteries, lithium-ion batteries, and supercapacitors, are discussed. PMID:26549729

  17. Engine Data Interpretation System (EDIS)

    NASA Technical Reports Server (NTRS)

    Cost, Thomas L.; Hofmann, Martin O.

    1990-01-01

    A prototype of an expert system was developed which applies qualitative or model-based reasoning to the task of post-test analysis and diagnosis of data resulting from a rocket engine firing. A combined component-based and process theory approach is adopted as the basis for system modeling. Such an approach provides a framework for explaining both normal and deviant system behavior in terms of individual component functionality. The diagnosis function is applied to digitized sensor time-histories generated during engine firings. The generic system is applicable to any liquid rocket engine but was adapted specifically in this work to the Space Shuttle Main Engine (SSME). The system is applied to idealized data resulting from turbomachinery malfunction in the SSME.

  18. Systems engineering for very large systems

    NASA Technical Reports Server (NTRS)

    Lewkowicz, Paul E.

    1993-01-01

    Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

  19. Dynamic modeling of electrochemical systems using linear graph theory

    NASA Astrophysics Data System (ADS)

    Dao, Thanh-Son; McPhee, John

    An electrochemical cell is a multidisciplinary system which involves complex chemical, electrical, and thermodynamical processes. The primary objective of this paper is to develop a linear graph-theoretical modeling for the dynamic description of electrochemical systems through the representation of the system topologies. After a brief introduction to the topic and a review of linear graphs, an approach to develop linear graphs for electrochemical systems using a circuitry representation is discussed, followed in turn by the use of the branch and chord transformation techniques to generate final dynamic equations governing the system. As an example, the application of linear graph theory to modeling a nickel metal hydride (NiMH) battery will be presented. Results show that not only the number of equations are reduced significantly, but also the linear graph model simulates faster compared to the original lumped parameter model. The approach presented in this paper can be extended to modeling complex systems such as an electric or hybrid electric vehicle where a battery pack is interconnected with other components in many different domains.

  20. An electrochemical surface plasmon resonance imaging system targeting cell analysis

    NASA Astrophysics Data System (ADS)

    Zhang, L. L.; Chen, X.; Wei, H. T.; Li, H.; Sun, J. H.; Cai, H. Y.; Chen, J. L.; Cui, D. F.

    2013-08-01

    This paper presents an electrochemical-surface plasmon resonance imaging (EC-SPRI) system, enabling the characterization of optical and electrical properties of cells, simultaneously. The developed surface plasmon resonance (SPR) imaging system was capable of imaging micro cavities with a dimension of 10 μm × 10 μm and differentiated glycerol solutions with a group of refractive indices (RIs). Furthermore, the EC-SPRI system was used to image A549 cells, suggesting corresponding RI and morphology changes during the cell death process. In the end, electrochemical and SPR methods were used in combination, recording oxidation peaks of A549 cells in the cyclic voltage curves and SPR response unit increase, simultaneously.

  1. Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

    SciTech Connect

    Gering, Kevin L

    2013-08-27

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

  2. Systems Engineering, Quality and Testing

    NASA Technical Reports Server (NTRS)

    Shepherd, Christena C.

    2015-01-01

    AS9100 has little to say about how to apply a Quality Management System (QMS) to aerospace test programs. There is little in the quality engineering Body of Knowledge that applies to testing, unless it is nondestructive examination or some type of lab or bench testing. If one examines how the systems engineering processes are implemented throughout a test program; and how these processes can be mapped to AS9100, a number of areas for involvement of the quality professional are revealed.

  3. System Engineering Paper

    NASA Technical Reports Server (NTRS)

    Heise, James; Hull, Bethanne J.; Bauer, Jonathan; Beougher, Nathan G.; Boe, Caleb; Canahui, Ricardo; Charles, John P.; Cooper, Zachary Davis Job; DeShaw, Mark A.; Fontanella, Luan Gasparetto; Friel, Mark; Goebel, Katie; Grant, Alex Martinsdacosta; Graves, Matt; Harms, Ryan Andrew; Hill, Aren; Lsely, Kevin Lee; Jose, Sonia; Klein, Andrew; Kolstad, Lauren Wickham; Lamp, Daniel A.; Lindquist, Mariangela Martin; Lopes, Daniel da Paula; Lourens, Rob; Matthews, Christopher

    2012-01-01

    The Iowa State University team, Team LunaCY, is composed of the following sub-teams: the main student organization, the Lunabotics Club; a senior mechanical engineering design course, ME 415; a senior multidisciplinary design course, ENGR 466; and a senior design course from Wartburg College in Waverly, Iowa. Team LunaCY designed and fabricated ART-E III, Astra Robotic Tractor- Excavator the Third, for the team's third appearance in the NASA Lunabotic Mining competition. While designing ART-E III, the team had four main goals for this year's competition:to reduce the total weight of the robot, to increase the amount of regolith simulant mined, to reduce dust, and to make ART-E III autonomous. After many designs and research, a final robot design was chosen that obtained all four goals of Team LunaCY. A few changes Team LunaCY made this year was to go to the electrical, computer, and software engineering club fest at Iowa State University to recruit engineering students to accomplish the task of making ART-E III autonomous. Team LunaCY chose to use LabView to program the robot and various sensors were installed to measure the distance between the robot and the surroundings to allow ART-E III to maneuver autonomously. Team LunaCY also built a testing arena to test prototypes and ART-E III in. To best replicate the competition arena at the Kennedy Space Center, a regolith simulant was made from sand, QuickCrete, and fly ash to cover the floor of the arena. Team LunaCY also installed fans to allow ventilation in the arena and used proper safety attire when working in the arena . With the additional practice in the testing arena and innovative robot design, Team LunaCY expects to make a strong appearance at the 2012 NASA Lunabotic Mining Competition. .

  4. A whole-cell electrochemical biosensing system based on bacterial inward electron flow for fumarate quantification.

    PubMed

    Si, Rong-Wei; Zhai, Dan-Dan; Liao, Zhi-Hong; Gao, Lu; Yong, Yang-Chun

    2015-06-15

    Fumarate is of great importance as it is an oncometabolite as well as food spoilage indicator. However, cost-effective and fast quantification method for fumarate is lacking although it is urgently required. This work developed an electrochemical whole-cell biosensing system for fumarate quantification. A sensitive inwards electric output (electron flow from electrode into bacteria) responded to fumarate in Shewanella oneidensis MR-1 was characterized, and an electrochemical fumarate biosensing system was developed without genetic engineering. The biosensing system delivered symmetric current peak immediately upon fumarate addition, where the peak area increased in proportion to the increasing fumarate concentration with a wide range of 2 μM-10 mM (R(2)=0.9997). The limit of detection (LOD) and the limit of quantification (LOQ) are 0.83 μM and 1.2 μM, respectively. This biosensing system displayed remarkable specificity to fumarate against other possible interferences. It was also successfully applied to samples of apple juice and kidney tissue. This study added new dimension to electrochemical biosensor design, and provide a simple, cost-effective, fast and robust tool for fumarate quantification. PMID:25558872

  5. Efficient Electrochemical Reduction of Nitrobenzene by Defect-Engineered TiO2-x Single Crystals.

    PubMed

    Liu, Chang; Zhang, Ai-Yong; Pei, Dan-Ni; Yu, Han-Qing

    2016-05-17

    TiO2 is a typical semiconductor and has been extensively used as an effective photocatalyst for environmental pollution control. But it could not be used as an electrochemical reductive catalyst because of its low electric conductivity and electrocatalytic activity. In this work, however, we demonstrate that TiO2 can act as an excellent cathodic electrocatalyst when its crystal shape, exposed facet and oxygen-stoichiometry are finely tailored by the local geometric and electronic structures. The defect-engineered TiO2-x single crystals dominantly exposed by high-energy {001} facets exhibits a high cathodic activity and great stability for electrochemical reduction of nitrobenzene, a typical refractory pollutant with high toxicity in environment. The single crystalline structure, the high-energy {001} facet and the defective oxygen vacancy of the defect-engineered TiO2-x single crystals are found to be mainly responsible for their cathodic superiority. With the findings in this work, a more practical non-Pd cathodic electrocatalyst could be prepared and applied for electrocatalytic reduction of refractory pollutants in water and wastewater, and extend the promising applications of TiO2 in the fields of environmental science. PMID:27128346

  6. Adaptive Systems Engineering: A Medical Paradigm for Practicing Systems Engineering

    SciTech Connect

    R. Douglas Hamelin; Ron D. Klingler; Christopher Dieckmann

    2011-06-01

    From its inception in the defense and aerospace industries, SE has applied holistic, interdisciplinary tools and work-process to improve the design and management of 'large, complex engineering projects.' The traditional scope of engineering in general embraces the design, development, production, and operation of physical systems, and SE, as originally conceived, falls within that scope. While this 'traditional' view has expanded over the years to embrace wider, more holistic applications, much of the literature and training currently available is still directed almost entirely at addressing the large, complex, NASA and defense-sized systems wherein the 'ideal' practice of SE provides the cradle-to-grave foundation for system development and deployment. Under such scenarios, systems engineers are viewed as an integral part of the system and project life-cycle from conception to decommissioning. In far less 'ideal' applications, SE principles are equally applicable to a growing number of complex systems and projects that need to be 'rescued' from overwhelming challenges that threaten imminent failure. The medical profession provides a unique analogy for this latter concept and offers a useful paradigm for tailoring our 'practice' of SE to address the unexpected dynamics of applying SE in the real world. In short, we can be much more effective as systems engineers as we change some of the paradigms under which we teach and 'practice' SE.

  7. Electrochemical system including lamella settler crystallizer

    DOEpatents

    Maimoni, Arturo

    1988-01-01

    A crystallizer which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as will as in other elecrochemical systems requiring separation for phases of different densities.

  8. One man electrochemical air revitalization system

    NASA Technical Reports Server (NTRS)

    Huddleston, J. C.; Aylward, J. R.

    1975-01-01

    An integrated water vapor electrolysis (WVE) hydrogen depolarized CO2 concentrator (HDC) system sized for one man support over a wide range of inlet air conditions was designed, fabricated, and tested. Data obtained during 110 days of testing verified that this system can provide the necessary oxygen, CO2 removal, and partial humidity control to support one man (without exceeding a cabin partial pressure of 3.0 mmHg for CO2 and while maintaining a 20% oxygen level), when operated at a WVE current of 50 amperes and an HDC current of 18 amperes. An evaluation to determine the physical properties of tetramethylammonium bicarbonate (TMAC) and hydroxide was made. This provides the necessary electrolyte information for designing an HDC cell using TMAC.

  9. Exploratory studies on some electrochemical cell systems

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Srikumar; Guha, D.

    Exploratory studies were conducted on cell systems with different metal anodes, and iodine and sulphur mixed with graphite powder in a polymer matrix as cathodes, using different electrolytes in non-aqueous and aqueous media as ionic charge carriers. The electrical conductance of the electrolyte solutions in aqueous and non-aqueous solvents, the open circuit voltage (OCV) and short circuit current (SCC) for the different cell systems were measured. To date, the non-aqueous solvents used in our studies were dimethylformamide, formamide, dioxan, and nitrobenzene, and the electrolytes used were potassium iodide, caustic potash, cetyltrimethylammonium bromide (CTAB), sodium lauryl sulphate (SLS) and calcium chloride. These electrolytes were used in both non-aqueous and aqueous media. In general, aqueous electrolyte solutions gave a better performance than non-aqueous electrolyte solutions. Of the aqueous electrolytes, the highest conductance was shown by potassium chloride solution in water (conductance=0.0334 mho). However, the best OCV and SCC were shown by aluminium as anode and iodine as cathode with a saturated solution of caustic potash in water. The OCV was 1.85 V and the SCC was 290 mA cm -2. The highest conductance among the non-aqueous systems was shown by caustic potash in formamide. (Conductance=0.013 mho.) The best OCV and SCC, however, were shown by a zinc anode and iodine cathode with saturated potassium chloride in formamide, having an OCV of 1.55 V and an SCC of 150 mA cm -2. Further studies are in progress to obtain detailed performance data and recharging characteristics of some of the more promising systems reported here.

  10. Nonlinear phase field model for electrodeposition in electrochemical systems

    SciTech Connect

    Liang, Linyun; Chen, Long-Qing

    2014-12-29

    A nonlinear phase-field model has been developed for describing the electrodeposition process in electrochemical systems that are highly out of equilibrium. Main thermodynamic driving forces for the electrode-electrolyte interface (EEI) evolution are limited to local variations of overpotential and ion concentration. Application of the model to Li-ion batteries describes the electrode interface motion and morphology change caused by charge mass transfer in the electrolyte, an electrochemical reaction at the EEI and cation deposition on the electrode surface during the charging operation. The Li electrodeposition rate follows the classical Butler-Volmer kinetics with exponentially and linearly depending on local overpotential and cation concentration at the electrode surface, respectively. Simulation results show that the Li deposit forms a fiber-like shape and grows parallel to the electric field direction. The longer and thicker deposits are observed both for higher current density and larger rate constant where the surface reaction rate is expected to be high. The proposed diffuse interface model well captures the metal electrodeposition phenomena in plenty of non-equilibrium electrochemical systems.

  11. Engine NOx reduction system

    SciTech Connect

    Berriman, L.P.; Zabsky, J.M.; Davis, J.W.; Hylton, W.H.

    1993-07-06

    Apparatus for use with an engine having a power-generating portion that burns a hydrocarbon fuel and air and produces hot exhaust gases is described, having a catalytic converter device that includes a catalyst for enhancing reactions of components of said exhaust gases, and having a conduit that couples said power-generating portion to said catalytic converter device, for reducing pollution in the exhaust, wherein said power-generating portion comprises a plurality of cylinders in which said fuel and air are burned, a mechanism for applying fuel and air to said cylinders, and a plurality of exhaust valves through which burned fuel and air is exhausted and which are connected to said upstream end of said conduit, said conduit including a manifold which is connected to a plurality of said exhaust valves and a downstream conduit portion which connects said manifold to said catalytic converter device, comprising: a device coupled to said conduit, which stores ammonia and injects it into said conduit at a location where the exhaust gases have a substantially maximum temperature, but which is devoid of open flames, to mix with said hot exhaust gases and pass with them along said conduit and then through said catalyst, said location being closer to said power-generating portion than to said catalytic converter and lying in said manifold.

  12. Intelligent Engine Systems: Acoustics

    NASA Technical Reports Server (NTRS)

    Wojno, John; Martens, Steve; Simpson, Benjamin

    2008-01-01

    An extensive study of new fan exhaust nozzle technologies was performed. Three new uniform chevron nozzles were designed, based on extensive CFD analysis. Two new azimuthally varying variants were defined. All five were tested, along with two existing nozzles, on a representative model-scale, medium BPR exhaust nozzle. Substantial acoustic benefits were obtained from the uniform chevron nozzle designs, the best benefit being provided by an existing design. However, one of the azimuthally varying nozzle designs exhibited even better performance than any of the uniform chevron nozzles. In addition to the fan chevron nozzles, a new technology was demonstrated, using devices that enhance mixing when applied to an exhaust nozzle. The acoustic benefits from these devices applied to medium BPR nozzles were similar, and in some cases superior to, those obtained from conventional uniform chevron nozzles. However, none of the low noise technologies provided equivalent acoustic benefits on a model-scale high BPR exhaust nozzle, similar to current large commercial applications. New technologies must be identified to improve the acoustics of state-of-the-art high BPR jet engines.

  13. Diffuse-charge dynamics in electrochemical systems

    NASA Astrophysics Data System (ADS)

    Bazant, Martin Z.; Thornton, Katsuyo; Ajdari, Armand

    2004-08-01

    The response of a model microelectrochemical system to a time-dependent applied voltage is analyzed. The article begins with a fresh historical review including electrochemistry, colloidal science, and microfluidics. The model problem consists of a symmetric binary electrolyte between parallel-plate blocking electrodes, which suddenly apply a voltage. Compact Stern layers on the electrodes are also taken into account. The Nernst-Planck-Poisson equations are first linearized and solved by Laplace transforms for small voltages, and numerical solutions are obtained for large voltages. The “weakly nonlinear” limit of thin double layers is then analyzed by matched asymptotic expansions in the small parameter ɛ=λD/L , where λD is the screening length and L the electrode separation. At leading order, the system initially behaves like an RC circuit with a response time of λDL/D (not λD2/D ), where D is the ionic diffusivity, but nonlinearity violates this common picture and introduces multiple time scales. The charging process slows down, and neutral-salt adsorption by the diffuse part of the double layer couples to bulk diffusion at the time scale, L2/D . In the “strongly nonlinear” regime (controlled by a dimensionless parameter resembling the Dukhin number), this effect produces bulk concentration gradients, and, at very large voltages, transient space charge. The article concludes with an overview of more general situations involving surface conduction, multicomponent electrolytes, and Faradaic processes.

  14. Industrial and Systems Engineering Applications in NASA

    NASA Technical Reports Server (NTRS)

    Shivers, Charles H.

    2006-01-01

    A viewgraph presentation on the many applications of Industrial and Systems Engineering used for safe NASA missions is shown. The topics include: 1) NASA Information; 2) Industrial Engineering; 3) Systems Engineering; and 4) Major NASA Programs.

  15. Current-potential characteristics of electrochemical systems

    SciTech Connect

    Battaglia, V.S.

    1993-07-01

    This dissertation contains investigations in three distinct areas. Chapters 1 and 2 provide an analysis of the effects of electromagnetic phenomena during the initial stages of cell discharge. Chapter 1 includes the solution to Maxwell`s equations for the penetration of the axial component of an electric field into an infinitely long cylindrical conductor. Chapter 2 contains the analysis of the conductor included in a radial circuit. Chapter 3 provides a complete description of the equations that describe the growth of an oxide film. A finite difference program was written to solve the equations. The system investigated is the iron/iron oxide in a basic, aqueous solution. Chapters 4 and 5 include the experimental attempts for replacing formaldehyde with an innocuous reducing agent for electroless deposition. In chapter 4, current-versus-voltage curves are provided for a sodium thiosulfate bath in the presence of a copper disk electrode. Also provided are the cathodic polarization curves of a copper/EDTA bath in the presence of a copper electrode. Chapter 5 contains the experimental results of work done with sodium hypophosphite as a reducing agent. Mixed-potential-versus-time curves for solutions containing various combinations of copper sulfate, nickel chloride, and hypophosphite in the presence of a palladium disk electrode provide an indication of the reducing power of the solutions.

  16. Electrochemical decontamination system for actinide processing gloveboxes

    SciTech Connect

    Wedman, D.E.; Lugo, J.L.; Ford, D.K.; Nelson, T.O.; Trujillo, V.L.; Martinez, H.E.

    1998-03-01

    An electrolytic decontamination technology has been developed and successfully demonstrated at Los Alamos National Laboratory (LANL) for the decontamination of actinide processing gloveboxes. The technique decontaminates the interior surfaces of stainless steel gloveboxes utilizing a process similar to electropolishing. The decontamination device is compact and transportable allowing it to be placed entirely within the glovebox line. In this way, decontamination does not require the operator to wear any additional personal protective equipment and there is no need for additional air handling or containment systems. Decontamination prior to glovebox decommissioning reduces the potential for worker exposure and environmental releases during the decommissioning, transport, and size reduction procedures which follow. The goal of this effort is to reduce contamination levels of alpha emitting nuclides for a resultant reduction in waste level category from High Level Transuranic (TRU) to low Specific Activity (LSA, less than or equal 100 nCi/g). This reduction in category results in a 95% reduction in disposal and disposition costs for the decontaminated gloveboxes. The resulting contamination levels following decontamination by this method are generally five orders of magnitude below the LSA specification. Additionally, the sodium sulfate based electrolyte utilized in the process is fully recyclable which results in the minimum of secondary waste. The process bas been implemented on seven gloveboxes within LANL`s Plutonium Facility at Technical Area 55. Of these gloveboxes, two have been discarded as low level waste items and the remaining five have been reused.

  17. Computer systems and software engineering

    NASA Technical Reports Server (NTRS)

    Mckay, Charles W.

    1988-01-01

    The High Technologies Laboratory (HTL) was established in the fall of 1982 at the University of Houston Clear Lake. Research conducted at the High Tech Lab is focused upon computer systems and software engineering. There is a strong emphasis on the interrelationship of these areas of technology and the United States' space program. In Jan. of 1987, NASA Headquarters announced the formation of its first research center dedicated to software engineering. Operated by the High Tech Lab, the Software Engineering Research Center (SERC) was formed at the University of Houston Clear Lake. The High Tech Lab/Software Engineering Research Center promotes cooperative research among government, industry, and academia to advance the edge-of-knowledge and the state-of-the-practice in key topics of computer systems and software engineering which are critical to NASA. The center also recommends appropriate actions, guidelines, standards, and policies to NASA in matters pertinent to the center's research. Results of the research conducted at the High Tech Lab/Software Engineering Research Center have given direction to many decisions made by NASA concerning the Space Station Program.

  18. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    1992-02-01

    ASPEN (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes. ASPEN can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations. It is supported by a comprehensive physical property system for computationmore » of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The ASPEN Input Language is oriented towards process engineers.« less

  19. Diesel engine fuel systems

    SciTech Connect

    Not Available

    1994-01-01

    The film shows the basic structure of diesel systems, including the parts and operation of injectors and fuel pumps. It discusses Bosch, General Motors, and Excello Equipment. This title has been declared obsolete for use within the sponsoring agency, but may have content value for educational use.

  20. Diesel engine fuel systems

    SciTech Connect

    1994-12-31

    The film shows the basic structure of diesel systems, including the parts and operation of injectors and fuel pumps. It discusses Bosch, General Motors, and Excello Equipment. This title has been declared obsolete for use within the sponsoring agency, but may have content value for educational use.

  1. Diesel engine catalytic combustor system. [aircraft engines

    NASA Technical Reports Server (NTRS)

    Ream, L. W. (Inventor)

    1984-01-01

    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

  2. Security systems engineering overview

    SciTech Connect

    Steele, B.J.

    1996-12-31

    Crime prevention is on the minds of most people today. The concern for public safety and the theft of valuable assets are being discussed at all levels of government and throughout the public sector. There is a growing demand for security systems that can adequately safeguard people and valuable assets against the sophistication of those criminals or adversaries who pose a threat. The crime in this country has been estimated at $70 billion in direct costs and up to $300 billion in indirect costs. Health insurance fraud alone is estimated to cost American businesses $100 billion. Theft, warranty fraud, and counterfeiting of computer hardware totaled $3 billion in 1994. A threat analysis is a prerequisite to any security system design to assess the vulnerabilities with respect to the anticipated threat. Having established a comprehensive definition of the threat, crime prevention, detection, and threat assessment technologies can be used to address these criminal activities. This talk will outline the process used to design a security system regardless of the level of security. This methodology has been applied to many applications including: government high security facilities; residential and commercial intrusion detection and assessment; anti-counterfeiting/fraud detection technologies (counterfeit currency, cellular phone billing, credit card fraud, health care fraud, passport, green cards, and questionable documents); industrial espionage detection and prevention (intellectual property, computer chips, etc.); and security barrier technology (creation of delay such as gates, vaults, etc.).

  3. Security systems engineering overview

    NASA Astrophysics Data System (ADS)

    Steele, Basil J.

    1997-01-01

    Crime prevention is on the minds of most people today. The concern for public safety and the theft of valuable assets are being discussed at all levels of government and throughout the public sector. There is a growing demand for security systems that can adequately safeguard people and valuable assets against the sophistication of those criminals or adversaries who pose a threat. The crime in this country has been estimated at 70 billion dollars in direct costs and up to 300 billion dollars in indirect costs. Health insurance fraud alone is estimated to cost American businesses 100 billion dollars. Theft, warranty fraud, and counterfeiting of computer hardware totaled 3 billion dollars in 1994. A threat analysis is a prerequisite to any security system design to assess the vulnerabilities with respect to the anticipated threat. Having established a comprehensive definition of the threat, crime prevention, detection, and threat assessment technologies can be used to address these criminal activities. This talk will outline the process used to design a security system regardless of the level of security. This methodology has been applied to many applications including: government high security facilities; residential and commercial intrusion detection and assessment; anti-counterfeiting/fraud detection technologies; industrial espionage detection and prevention; security barrier technology.

  4. Hubble Space Telescope systems engineering

    NASA Technical Reports Server (NTRS)

    Wojtalik, F. S.

    1988-01-01

    The role of systems engineering in the Hubble Space Telescope (HST) development program at NASA Marshall is reviewed. The scientific objectives and overall characteristics of the HST are recalled, and particular attention is given to the early identification and correction of problems in the optical system, the pointing-control system (maneuvering and fine guidance), the rate-gyro assembly, reaction-wheel isolation, the battery reconditioning circuit, and optical cleanliness.

  5. Engineering intelligent tutoring systems

    NASA Technical Reports Server (NTRS)

    Warren, Kimberly C.; Goodman, Bradley A.

    1993-01-01

    We have defined an object-oriented software architecture for Intelligent Tutoring Systems (ITS's) to facilitate the rapid development, testing, and fielding of ITS's. This software architecture partitions the functionality of the ITS into a collection of software components with well-defined interfaces and execution concept. The architecture was designed to isolate advanced technology components, partition domain dependencies, take advantage of the increased availability of commercial software packages, and reduce the risks involved in acquiring ITS's. A key component of the architecture, the Executive, is a publish and subscribe message handling component that coordinates all communication between ITS components.

  6. Jet engine air intake system

    NASA Technical Reports Server (NTRS)

    Sorensen, N. E.; Latham, E. A. (Inventor)

    1977-01-01

    An axisymmetric air intake system for a jet aircraft engine comprising a fixed cowl extending outwardly from the face of the engine, a centerbody coaxially disposed within the cowl, and an actuator for axially displacing the centerbody within the cowl was developed. The cowl and centerbody define a main airflow passageway therebetween, the configuration of which is changed by displacement of the centerbody. The centerbody includes a forwardly-located closeable air inlet which communicates with a centerbody auxiliary airflow passageway to provide auxiliary airflow to the engine. In one embodiment, a system for opening and closing the centerbody air inlet is provided by a dual-member centerbody, the forward member of which may be displaced axially with respect to the aft member.

  7. Bioelectrochemical interface engineering: toward the fabrication of electrochemical biosensors, biofuel cells, and self-powered logic biosensors.

    PubMed

    Zhou, Ming; Dong, Shaojun

    2011-11-15

    Over the past decade, researchers have devoted considerable attention to the integration of living organisms with electronic elements to yield bioelectronic devices. Not only is the integration of DNA, enzymes, or whole cells with electronics of scientific interest, but it has many versatile potential applications. Researchers are using these ideas to fabricate biosensors for analytical applications and to assemble biofuel cells (BFCs) and biomolecule-based devices. Other research efforts include the development of biocomputing systems for information processing. In this Account, we focus on our recent progress in engineering at the bioelectrochemical interface (BECI) for the rational design and construction of important bioelectronic devices, ranging from electrochemical (EC-) biosensors to BFCs, and self-powered logic biosensors. Hydrogels and sol-gels provide attractive materials for the immobilization of enzymes because they make EC-enzyme biosensors stable and even functional in extreme environments. We use a layer-by-layer (LBL) self-assembly technique to fabricate multicomponent thin films on the BECI at the nanometer scale. Additionally, we demonstrate how carbon nanomaterials have paved the way for new and improved EC-enzyme biosensors. In addition to the widely reported BECI-based electrochemical impedance spectroscopy (EIS)-type aptasensors, we integrate the LBL technique with our previously developed "solid-state probe" technique for redox probes immobilization on electrode surfaces to design and fabricate BECI-based differential pulse voltammetry (DPV)-type aptasensors. BFCs can directly harvest energy from ambient biofuels as green energy sources, which could lead to their application as simple, flexible, and portable power sources. Porous materials provide favorable microenvironments for enzyme immobilization, which can enhance BFC power output. Furthermore, by introducing aptamer-based logic systems to BFCs, such systems could be applied as self

  8. Computer Jet-Engine-Monitoring System

    NASA Technical Reports Server (NTRS)

    Disbrow, James D.; Duke, Eugene L.; Ray, Ronald J.

    1992-01-01

    "Intelligent Computer Assistant for Engine Monitoring" (ICAEM), computer-based monitoring system intended to distill and display data on conditions of operation of two turbofan engines of F-18, is in preliminary state of development. System reduces burden on propulsion engineer by providing single display of summary information on statuses of engines and alerting engineer to anomalous conditions. Effective use of prior engine-monitoring system requires continuous attention to multiple displays.

  9. Morphological Engineering of CVD-Grown Transition Metal Dichalcogenides for Efficient Electrochemical Hydrogen Evolution.

    PubMed

    Ji, Qingqing; Zhang, Yu; Shi, Jianping; Sun, Jingyu; Zhang, Yanfeng; Liu, Zhongfan

    2016-08-01

    2D layered transition metal dichalcogenides (TMDCs) have emerged as new possibilites beyond conventional particulate catalysts in facilitating efficient electrochemical hydrogen evolution. This is mainly mediated by the ultrahigh surface-to-volume ratio and the effective coupling of all active sites with supporting electrodes. Especially, the facile chemical vapor deposition (CVD) method has enabled morphological engineering of monolayer TMDC catalysts toward development of abundant active edge sites within the 2D plane. Here, two pathways to achieve such purpose are highlighted, either by non-equilibrium growth of MoS2 dendrites or throughout high-density nucleation of MoS2 nanoflakes directly on the electrode materials. Furthermore, future research directions have also been proposed and discussed to further enhance the efficiency of such unique catalysts. PMID:26848711

  10. Biodegradability engineering of biodegradable Mg alloys: Tailoring the electrochemical properties and microstructure of constituent phases

    NASA Astrophysics Data System (ADS)

    Cha, Pil-Ryung; Han, Hyung-Seop; Yang, Gui-Fu; Kim, Yu-Chan; Hong, Ki-Ha; Lee, Seung-Cheol; Jung, Jae-Young; Ahn, Jae-Pyeong; Kim, Young-Yul; Cho, Sung-Youn; Byun, Ji Young; Lee, Kang-Sik; Yang, Seok-Jo; Seok, Hyun-Kwang

    2013-08-01

    Crystalline Mg-based alloys with a distinct reduction in hydrogen evolution were prepared through both electrochemical and microstructural engineering of the constituent phases. The addition of Zn to Mg-Ca alloy modified the corrosion potentials of two constituent phases (Mg + Mg2Ca), which prevented the formation of a galvanic circuit and achieved a comparable corrosion rate to high purity Mg. Furthermore, effective grain refinement induced by the extrusion allowed the achievement of much lower corrosion rate than high purity Mg. Animal studies confirmed the large reduction in hydrogen evolution and revealed good tissue compatibility with increased bone deposition around the newly developed Mg alloy implants. Thus, high strength Mg-Ca-Zn alloys with medically acceptable corrosion rate were developed and showed great potential for use in a new generation of biodegradable implants.

  11. Re-engineering aptamers to support reagentless, self-reporting electrochemical sensors†

    PubMed Central

    White, Ryan J.; Rowe, Aaron A.

    2010-01-01

    Electrochemical aptamer-based (E-AB) sensors have emerged as a promising and versatile new biosensor platform. Combining the generality and specificity of aptamer–ligand interactions with the selectivity and convenience of electrochemical readouts, this approach affords the detection of a wide variety of targets directly in complex, contaminant-ridden samples, such as whole blood, foodstuffs and crude soil extracts, without the need for exogenous reagents or washing steps. Signaling in this class of sensors is predicated on target-induced changes in the conformation of an electrode-bound probe aptamer that, in turn, changes the efficiency with which a covalently attached redox tag exchanges electrons with the interrogating electrode. Aptamer selection strategies, however, typically do not select for the conformation-switching architectures, and as such several approaches have been reported to date by which aptamers can be re-engineered such that they undergo the binding-induced switching required to support efficient E-AB signaling. Here, we systematically compare the merits of these re-engineering approaches using representative aptamers specific to the small molecule adenosine triphosphate and the protein human immunoglobulin E. We find that, while many aptamer architectures support E-AB signaling, the observed signal gain (relative change in signal upon target binding) varies by more than two orders of magnitude across the various constructs we have investigated (e.g., ranging from −10% to 200% for our ATP sensors). Optimization of the switching architecture is thus an important element in achieving maximum E-AB signal gain and we find that this optimal geometry is specific to the aptamer sequence upon which the sensor is built. PMID:20174715

  12. 2.0 AEDL Systems Engineering

    NASA Technical Reports Server (NTRS)

    Graves, Claude

    2005-01-01

    Some engineering topics: Some Initial Thoughts. Capability Description. Capability State-of-the-Art. Capability Requirements. Systems Engineering. Capability Roadmap. Capability Maturity. Candidate Technologies. Metrics.

  13. Building America Systems Engineering Approach

    SciTech Connect

    2011-12-15

    The Building America Research Teams use a systems engineering approach to achieve higher quality and energy savings in homes. Using these techniques, the energy consumption of new houses can be reduced by 40% or more with little or no impact on the cost of ownership.

  14. Sandia National Laboratories Electrochemical Storage System Abuse Test Procedure Manual

    SciTech Connect

    Unkelhaeuser, Terry; Smallwood David

    1999-07-01

    The series of tests described in this report are intended to simulate actual use and abuse conditions and internally initiated failures that may be experienced in electrochemical storage systems (ECSS). These tests were derived from Failure Mode and Effect Analysis, user input, and historical abuse testing. The tests are to provide a common framework for various ECSS technologies. The primary purpose of testing is to gather response information to external/internal inputs. Some tests and/or measurements may not be required for some ECSS technologies and designs if it is demonstrated that a test is not applicable, and the measurements yield no useful information.

  15. Management issues in systems engineering

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Chamberlain, Robert G.; Aster, Robert; Bilardo, Vincent; Forsberg, Kevin; Mooz, Hal; Polaski, Lou; Wade, Ron

    1993-01-01

    When applied to a system, the doctrine of successive refinement is a divide-and-conquer strategy. Complex systems are sucessively divided into pieces that are less complex, until they are simple enough to be conquered. This decomposition results in several structures for describing the product system and the producing system. These structures play important roles in systems engineering and project management. Many of the remaining sections in this chapter are devoted to describing some of these key structures. Structures that describe the product system include, but are not limited to, the requirements tree, system architecture and certain symbolic information such as system drawings, schematics, and data bases. The structures that describe the producing system include the project's work breakdown, schedules, cost accounts and organization.

  16. Management System for Engineering Ethics

    NASA Astrophysics Data System (ADS)

    Yashiro, Tomonari

    In the context of independent profession based societies, ethics charter/codes of professional bodies have significant influence on the conduct of engineers. Contrarily in Japan, most of active engineers are in-house and feel immediate identity as the member of firm or institution, rather than professional bodies. Therefore, establishment and operation of engineering ethics management system (E2ms) is essential for incentive to make innovative and ethical decision with confidence. The paper introduces the outline of the educational kit for E2ms developed by the author. The kit aims to enhance ability of management relevant to E2ms. The kit also involves ten cases for case method teaching. The test use of the kit indicates the potential to create satisfactory educational achievement.

  17. Electrochemical and optical studies of model photosynthetic systems

    SciTech Connect

    Not Available

    1992-01-15

    The objective of this research is to obtain a better understanding of the relationship between the structural organization of photosynthetic pigments and their spectroscopic and electrochemical properties. Defined model systems were studied first. These included the least ordered (solutions) through the most highly ordered (Langmuir-Blodgett (LB) monolayers and self-assembled monolayers) systems containing BChl, BPheo, and UQ. Molecules other than the photosynthetic pigments and quinones were also examined, including chromophores (i.e. surface active cyanine dyes and phtahlocyanines) an redox active compounds (methyl viologen (MV) and surfactant ferrocenes), in order to develop the techniques needed to study the photosynthetic components. Because the chlorophylls are photosensitive and labile, it was easier first to develop procedures using stable species. Three different techniques were used to characterize these model systems. These included electrochemical techniques for determining the standard oxidation and reduction potentials of the photosynthetic components as well as methods for determining the heterogeneous electron transfer rate constants for BChl and BPheo at metal electrodes (Pt and Au). Resonance Raman (RR) and surface enhanced resonance Raman (SERR) spectroscopy were used to determine the spectra of the photosynthetic pigments and model compounds. SERRS was also used to study several types of photosynthetic preparations.

  18. Gas turbine engine control system

    NASA Technical Reports Server (NTRS)

    Idelchik, Michael S. (Inventor)

    1991-01-01

    A control system and method of controlling a gas turbine engine. The control system receives an error signal and processes the error signal to form a primary fuel control signal. The control system also receives at least one anticipatory demand signal and processes the signal to form an anticipatory fuel control signal. The control system adjusts the value of the anticipatory fuel control signal based on the value of the error signal to form an adjusted anticipatory signal and then the adjusted anticipatory fuel control signal and the primary fuel control signal are combined to form a fuel command signal.

  19. Aerothermodynamic systems engineering and design

    NASA Astrophysics Data System (ADS)

    A reference source for various aspects of aerothermodynamic systems engineering and design is presented. Air conditioning load analysis is addressed, including physiological requirements, heat and cooling load equations, skin temperature computational methods, cooling loads due to radiation through transparent areas, heating and cooling loads due to internal sources, and practical considerations in the determination of overall heating and cooling loads. Refrigeration system design is considered, including air cycle systems, vapor cycle systems, combined vapor cycle and air cycle systems, and thermoelectric cooling. Heating methods is heating system design and low pressure and high pressure systems in air distribution system design are addressed. Procedures and equations commonly used for aerospace applications of these technologies are included.

  20. The engineering of cybernetic systems

    NASA Astrophysics Data System (ADS)

    Fry, Robert L.

    2002-05-01

    This tutorial develops a logical basis for the engineering of systems that operate cybernetically. The term cybernetic system has a clear quantitative definition. It is a system that dynamically matches acquired information to selected actions relative to a computational issue that defines the essential purpose of the system or machine. This notion requires that information and control be further quantified. The logic of questions and assertions as developed by Cox provides one means of doing this. The design and operation of cybernetic systems can be understood by contrasting these kinds of systems with communication systems and information theory as developed by Shannon. The joint logic of questions and assertions can be seen to underlie and be common to both information theory as applied to the design of discrete communication systems and to a theory of discrete general systems. The joint logic captures a natural complementarity between systems that transmit and receive information and those that acquire and act on it. Specific comparisons and contrasts are made between the source rate and channel capacity of a communication system and the acquisition rate and control capacity of a general system. An overview is provided of the joint logic of questions and assertions and the ties that this logic has to both conventional information theory and to a general theory of systems. I-diagrams, the interrogative complement of Venn diagrams, are described as providing valuable reasoning tools. An initial framework is suggested for the design of cybernetic systems. Two examples are given to illustrate this framework as applied to discrete cybernetic systems. These examples include a predator-prey problem as illustrated through "The Dog Chrysippus Pursuing its Prey," and the derivation of a single-neuron system that operates cybernetically and is biologically plausible. Future areas of research are highlighted which require development for a mature engineering framework.

  1. Systems, methods and computer readable media for estimating capacity loss in rechargeable electrochemical cells

    DOEpatents

    Gering, Kevin L.

    2013-06-18

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples charge characteristics of the electrochemical cell. The computing system periodically determines cell information from the charge characteristics of the electrochemical cell. The computing system also periodically adds a first degradation characteristic from the cell information to a first sigmoid expression, periodically adds a second degradation characteristic from the cell information to a second sigmoid expression and combines the first sigmoid expression and the second sigmoid expression to develop or augment a multiple sigmoid model (MSM) of the electrochemical cell. The MSM may be used to estimate a capacity loss of the electrochemical cell at a desired point in time and analyze other characteristics of the electrochemical cell. The first and second degradation characteristics may be loss of active host sites and loss of free lithium for Li-ion cells.

  2. Information technology security system engineering methodology

    NASA Technical Reports Server (NTRS)

    Childs, D.

    2003-01-01

    A methodology is described for system engineering security into large information technology systems under development. The methodology is an integration of a risk management process and a generic system development life cycle process. The methodology is to be used by Security System Engineers to effectively engineer and integrate information technology security into a target system as it progresses through the development life cycle. The methodology can also be used to re-engineer security into a legacy system.

  3. Heat engine generator control system

    DOEpatents

    Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

    1998-05-12

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

  4. Heat engine generator control system

    DOEpatents

    Rajashekara, Kaushik; Gorti, Bhanuprasad Venkata; McMullen, Steven Robert; Raibert, Robert Joseph

    1998-01-01

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

  5. Solar dish/engine systems

    SciTech Connect

    Not Available

    1998-04-01

    Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun`s rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

  6. Aptamer based electrochemical sensor system for protein using the generation/collection mode of scanning electrochemical microscope (SECM).

    PubMed

    Park, Kyungsoon; Kwon, Dohyoung; Kwak, Juhyoun

    2011-05-01

    To detect the target molecules, aptamers are currently focused on and the use of aptamers for biosensing is particularly interesting, as aptamers could substitute antibodies in bioanalytical sensing. So this paper describes the novel electrochemical system for protein in sandwich manner by using the aptamers and the scanning electrochemical microscope (SECM). For protein detection, sandwich system is ideal since labeling of the target protein is not necessary. To develop the electrochemical protein sensor system, thrombin was chosen as a target protein since many aptamers for it were already reported and two different aptamers, which recognize different positions of thrombin, were chosen to construct sandwich type sensing system. In order to obtain the electrochemical signal, the glucose oxidase (GOD) used for labeling the detection aptamers since it has large amount of stability in aqueous solution. One aptamer was immobilized onto the gold electrode and the other aptamer for detection was labeled with GOD for generation of the electric signal. Thrombin was detected in sandwich manner with aptamer immobilized onto the gold electrode and the GOD labeled aptamer. The enzymatic signal, generated from glucose addition after the formation of the complex of thrombin, was measured. The generation-collection mode of SECM was used for amperometric H2O2 detection. PMID:21780447

  7. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    1998-09-14

    PRO ASPEN/PC1.0 (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes and has been ported to run on a PC. PRO ASPEN/PC1.0 can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations.more » It is supported by a comprehensive physical property system for computation of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The PRO ASPEN/PC1.0 Input Language is oriented towards process engineers.« less

  8. SMAP Instrument Mechanical System Engineering

    NASA Technical Reports Server (NTRS)

    Slimko, Eric; French, Richard; Riggs, Benjamin

    2013-01-01

    The Soil Moisture Active Passive (SMAP) mission, scheduled for launch by the end of 2014, is being developed to measure the soil moisture and soil freeze/thaw state on a global scale over a three-year period. The accuracy, resolution, and global coverage of SMAP measurements are invaluable across many science and applications disciplines including hydrology, climate, carbon cycle, and the meteorological, environment, and ecology applications communities. The SMAP observatory is composed of a despun bus and a spinning instrument platform that includes both a deployable 6 meter aperture low structural frequency Astromesh reflector and a spin control system. The instrument section has engendered challenging mechanical system issues associated with the antenna deployment, flexible antenna pointing in the context of a multitude of disturbances, spun section mass properties, spin control system development, and overall integration with the flight system on both mechanical and control system levels. Moreover, the multitude of organizations involved, including two major vendors providing the spin subsystem and reflector boom assembly plus the flight system mechanical and guidance, navigation, and control teams, has led to several unique system engineering challenges. Capturing the key physics associated with the function of the flight system has been challenging due to the many different domains that are applicable. Key interfaces and operational concepts have led to complex negotiations because of the large number of organizations that integrate with the instrument mechanical system. Additionally, the verification and validation concerns associated with the mechanical system have had required far-reaching involvement from both the flight system and other subsystems. The SMAP instrument mechanical systems engineering issues and their solutions are described in this paper.

  9. Solar-Electrochemical Power System for a Mars Mission

    NASA Technical Reports Server (NTRS)

    Withrow, Colleen A.; Morales, Nelson

    1994-01-01

    This report documents a sizing study of a variety of solar electrochemical power systems for the intercenter NASA study known as 'Mars Exploration Reference Mission'. Power systems are characterized for a variety of rovers, habitation modules, and space transport vehicles based on requirements derived from the reference mission. The mission features a six-person crew living on Mars for 500 days. Mission power requirements range from 4 kWe to 120 kWe. Primary hydrogen and oxygen fuel cells, regenerative hydrogen and oxygen fuel cells, sodium sulfur batteries advanced photovoltaic solar arrays of gallium arsenide on germanium with tracking and nontracking mechanisms, and tent solar arrays of gallium arsenide on germanium are evaluated and compared.

  10. Systems engineering: A problem of perception

    SciTech Connect

    Senglaub, M.

    1995-08-01

    The characterization of systems engineering as a discipline, process, procedure or a set of heuristics will have an impact on the implementation strategy, the training methodology, and operational environment. The systems engineering upgrade activities in the New Mexico Weapons Development Center and a search of systems engineering related information provides evidence of a degree of ambiguity in this characterization of systems engineering. A case is made in this article for systems engineering being the engineering discipline applied to the science of complexity. Implications of this characterization and some generic issues are delineated with the goal of providing an enterprise with a starting point for developing its business environment.

  11. Stirling Engine Dynamic System Modeling

    NASA Technical Reports Server (NTRS)

    Nakis, Christopher G.

    2004-01-01

    The Thermo-Mechanical systems branch at the Glenn Research Center focuses a large amount time on Stirling engines. These engines will be used on missions where solar power is inefficient, especially in deep space. I work with Tim Regan and Ed Lewandowski who are currently developing and validating a mathematical model for the Stirling engines. This model incorporates all aspects of the system including, mechanical, electrical and thermodynamic components. Modeling is done through Simplorer, a program capable of running simulations of the model. Once created and then proven to be accurate, a model is used for developing new ideas for engine design. My largest specific project involves varying key parameters in the model and quantifying the results. This can all be done relatively trouble-free with the help of Simplorer. Once the model is complete, Simplorer will do all the necessary calculations. The more complicated part of this project is determining which parameters to vary. Finding key parameters depends on the potential for a value to be independently altered in the design. For example, a change in one dimension may lead to a proportional change to the rest of the model, and no real progress is made. Also, the ability for a changed value to have a substantial impact on the outputs of the system is important. Results will be condensed into graphs and tables with the purpose of better communication and understanding of the data. With the changing of these parameters, a more optimal design can be created without having to purchase or build any models. Also, hours and hours of results can be simulated in minutes. In the long run, using mathematical models can save time and money. Along with this project, I have many other smaller assignments throughout the summer. My main goal is to assist in the processes of model development, validation and testing.

  12. Electrochemical, H2O2-Boosted Catalytic Oxidation System

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Thompson, John O.; Schussel, Leonard J.

    2004-01-01

    An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which it increases oxidation capabilities, supplies H2O2 when needed, reduces the total organic carbon (TOC) content of treated water to a low level, consumes less energy than prior systems do, reduces the risk of contamination, and costs less to operate. This system was developed as a variant of part of an improved waste-management subsystem of the life-support system of a spacecraft. Going beyond its original intended purpose, it offers the advantage of being able to produce H2O2 on demand for surface sterilization and/or decontamination: this is a major advantage inasmuch as the benign byproducts of this H2O2 system, unlike those of systems that utilize other chemical sterilants, place no additional burden of containment control on other spacecraft air- or water-reclamation systems.

  13. Characterization of electrochemical systems and batteries: Materials and systems

    SciTech Connect

    McBreen, J.

    1992-12-01

    Materials are a pacing problem in battery development. The battery environment, particularly in rechargeable batteries, places great demands on materials. Characterization of battery materials is difficult because of their complex nature. In many cases meaningful characterization requires iii situ methods. Fortunately, several new electrochemical and spectroscopic techniques for in situ characterization studies have recently become available, and reports of new techniques have become more frequent. The opportunity now exists to utilize advanced instrumentation to define detailed features, participating chemical species and interfacial structure of battery materials with a precision heretofore not possible. This overview gives key references to these techniques and discusses the application of x-ray absorption spectroscopy to the study of battery materials.

  14. Characterization of electrochemical systems and batteries: Materials and systems

    SciTech Connect

    McBreen, J.

    1992-01-01

    Materials are a pacing problem in battery development. The battery environment, particularly in rechargeable batteries, places great demands on materials. Characterization of battery materials is difficult because of their complex nature. In many cases meaningful characterization requires iii situ methods. Fortunately, several new electrochemical and spectroscopic techniques for in situ characterization studies have recently become available, and reports of new techniques have become more frequent. The opportunity now exists to utilize advanced instrumentation to define detailed features, participating chemical species and interfacial structure of battery materials with a precision heretofore not possible. This overview gives key references to these techniques and discusses the application of x-ray absorption spectroscopy to the study of battery materials.

  15. Multimedia Feedback Systems for Engineering

    SciTech Connect

    Gladwell, S.; Gottlieb, E.J.; McDonald, M.J.; Slutter, C.L.

    1998-12-15

    The World Wide Web has become a key tool for information sharing. Engineers and scientists are finding that the web is especially suited to publishing the graphical, multi-layered information that is typical of their work. Web pages are easier to distribute than hardcopy. Web movies have become more accessible, in many offices, than videos. Good VRML viewing software, bundled with most new PCs, has sufficient power to support many engineering needs. In addition to publishing information science and engineering has an important tradition of peer and customer review. Reports, drawings and graphs are typically printed, distributed, reviewed, marked up, and returned to the author. Adding review comments to paper is easy. When, however, the information is in electronic form, this ease of review goes away. It's hard to write on videos. It's even harder to write comments on animated 3D models. These feedback limitations reduce the value of the information overall. Fortunately, the web can also be a useful tool for collecting peer and customer review information. When properly formed, web reports, movies, and 3D animations can be readily linked to review notes. This paper describes three multimedia feed-back systems that Sandia National Laboratories has developed to tap that potential. Each system allows people to make context-sensitive comments about specific web content and electronically ties the comments back to the web content being referenced. The fuel system ties comments to specific web pages, the second system ties the comments to specific frames of digital movies, and the third ties the comments to specific times and viewpoints within 3D animations. In addition to the technologies, this paper describes how they are being used to support intelligent machine systems design at Sandia.

  16. Upper Limits for Power Yield in Thermal, Chemical, and Electrochemical Systems

    NASA Astrophysics Data System (ADS)

    Sieniutycz, Stanislaw

    2010-03-01

    We consider modeling and power optimization of energy converters, such as thermal, solar and chemical engines and fuel cells. Thermodynamic principles lead to expressions for converter's efficiency and generated power. Efficiency equations serve to solve the problems of upgrading or downgrading a resource. Power yield is a cumulative effect in a system consisting of a resource, engines, and an infinite bath. While optimization of steady state systems requires using the differential calculus and Lagrange multipliers, dynamic optimization involves variational calculus and dynamic programming. The primary result of static optimization is the upper limit of power, whereas that of dynamic optimization is a finite-rate counterpart of classical reversible work (exergy). The latter quantity depends on the end state coordinates and a dissipation index, h, which is the Hamiltonian of the problem of minimum entropy production. In reacting systems, an active part of chemical affinity constitutes a major component of the overall efficiency. The theory is also applied to fuel cells regarded as electrochemical flow engines. Enhanced bounds on power yield follow, which are stronger than those predicted by the reversible work potential.

  17. Professional Issues in System Safety Engineering

    NASA Astrophysics Data System (ADS)

    McDermid, John; Thomas, Martyn; Redmill, Felix

    For many years the profession of system safety engineering has been emerging. This paper argues that the time has now come when it requires recognition, a voice, proper governance and leadership. System safety engineering is an amalgam of many disciplines, in particular, software engineering, safety engineering and management, and systems engineering, and this paper shows that system safety engineering must address the most difficult aspects of all of these. But professional matters extend beyond merely technical considerations, and the paper concludes by showing why there is the need for a new professional body.

  18. Airbreathing combined cycle engine systems

    NASA Technical Reports Server (NTRS)

    Rohde, John

    1992-01-01

    The Air Force and NASA share a common interest in developing advanced propulsion systems for commercial and military aerospace vehicles which require efficient acceleration and cruise operation in the Mach 4 to 6 flight regime. The principle engine of interest is the turboramjet; however, other combined cycles such as the turboscramjet, air turborocket, supercharged ejector ramjet, ejector ramjet, and air liquefaction based propulsion are also of interest. Over the past months careful planning and program implementation have resulted in a number of development efforts that will lead to a broad technology base for those combined cycle propulsion systems. Individual development programs are underway in thermal management, controls materials, endothermic hydrocarbon fuels, air intake systems, nozzle exhaust systems, gas turbines and ramjet ramburners.

  19. Electrochemical and mechanical polishing and shaping method and system

    NASA Technical Reports Server (NTRS)

    Engelhaupt, Darell E. (Inventor); Gubarev, Mikhail V. (Inventor); Jones, William David (Inventor); Ramsey, Brian D. (Inventor); Benson, Carl M. (Inventor)

    2011-01-01

    A method and system are provided for the shaping and polishing of the surface of a material selected from the group consisting of electrically semi-conductive materials and conductive materials. An electrically non-conductive polishing lap incorporates a conductive electrode such that, when the polishing lap is placed on the material's surface, the electrode is placed in spaced-apart juxtaposition with respect to the material's surface. A liquid electrolyte is disposed between the material's surface and the electrode. The electrolyte has an electrochemical stability constant such that cathodic material deposition on the electrode is not supported when a current flows through the electrode, the electrolyte and the material. As the polishing lap and the material surface experience relative movement, current flows through the electrode based on (i) adherence to Faraday's Law, and (ii) a pre-processing profile of the surface and a desired post-processing profile of the surface.

  20. Detection of Greenhouse Gas Precursors from Diesel Engines Using Electrochemical and Photoacoustic Sensors

    PubMed Central

    Mothé, Geórgia; Castro, Maria; Sthel, Marcelo; Lima, Guilherme; Brasil, Laisa; Campos, Layse; Rocha, Aline; Vargas, Helion

    2010-01-01

    Atmospheric pollution is one of the worst threats to modern society. The consequences derived from different forms of atmospheric pollution vary from the local to the global scale, with deep impacts on climate, environment and human health. Several gaseous pollutants, even when present in trace concentrations, play a fundamental role in important processes that occur in atmosphere. Phenomena such as global warming, photochemical smog formation, acid rain and the depletion of the stratospheric ozone layer are strongly related to the increased concentration of certain gaseous species in the atmosphere. The transport sector significantly produces atmospheric pollution, mainly when diesel oil is used as fuel. Therefore, new methodologies based on selective and sensitive gas detection schemes must be developed in order to detect and monitor pollutant gases from this source. In this work, CO2 Laser Photoacoustic Spectroscopy was used to evaluate ethylene emissions and electrochemical analyzers were used to evaluate the emissions of CO, NOx and SO2 from the exhaust of diesel powered vehicles (rural diesel with 5% of biodiesel, in this paper called only diesel) at different engine rotation speeds. Concentrations in the range 6 to 45 ppmV for ethylene, 109 to 1,231 ppmV for carbon monoxide, 75 to 868 ppmV for nitrogen oxides and 3 to 354 ppmV for sulfur dioxide were obtained. The results indicate that the detection techniques used were sufficiently selective and sensitive to detect the gaseous species mentioned above in the ppmV range. PMID:22163437

  1. Detection of greenhouse gas precursors from diesel engines using electrochemical and photoacoustic sensors.

    PubMed

    Mothé, Geórgia; Castro, Maria; Sthel, Marcelo; Lima, Guilherme; Brasil, Laisa; Campos, Layse; Rocha, Aline; Vargas, Helion

    2010-01-01

    Atmospheric pollution is one of the worst threats to modern society. The consequences derived from different forms of atmospheric pollution vary from the local to the global scale, with deep impacts on climate, environment and human health. Several gaseous pollutants, even when present in trace concentrations, play a fundamental role in important processes that occur in atmosphere. Phenomena such as global warming, photochemical smog formation, acid rain and the depletion of the stratospheric ozone layer are strongly related to the increased concentration of certain gaseous species in the atmosphere. The transport sector significantly produces atmospheric pollution, mainly when diesel oil is used as fuel. Therefore, new methodologies based on selective and sensitive gas detection schemes must be developed in order to detect and monitor pollutant gases from this source. In this work, CO(2) Laser Photoacoustic Spectroscopy was used to evaluate ethylene emissions and electrochemical analyzers were used to evaluate the emissions of CO, NO(x) and SO(2) from the exhaust of diesel powered vehicles (rural diesel with 5% of biodiesel, in this paper called only diesel) at different engine rotation speeds. Concentrations in the range 6 to 45 ppmV for ethylene, 109 to 1,231 ppmV for carbon monoxide, 75 to 868 ppmV for nitrogen oxides and 3 to 354 ppmV for sulfur dioxide were obtained. The results indicate that the detection techniques used were sufficiently selective and sensitive to detect the gaseous species mentioned above in the ppmV range. PMID:22163437

  2. Systems Engineering and Reusable Avionics

    NASA Technical Reports Server (NTRS)

    Conrad, James M.; Murphy, Gloria

    2010-01-01

    One concept for future space flights is to construct building blocks for a wide variety of avionics systems. Once a unit has served its original purpose, it can be removed from the original vehicle and reused in a similar or dissimilar function, depending on the function blocks the unit contains. For example: Once a lunar lander has reached the moon's surface, an engine controller for the Lunar Decent Module would be removed and used for a lunar rover motor control unit or for a Environmental Control Unit for a Lunar Habitat. This senior design project included the investigation of a wide range of functions of space vehicles and possible uses. Specifically, this includes: (1) Determining and specifying the basic functioning blocks of space vehicles. (2) Building and demonstrating a concept model. (3) Showing high reliability is maintained. The specific implementation of this senior design project included a large project team made up of Systems, Electrical, Computer, and Mechanical Engineers/Technologists. The efforts were made up of several sub-groups that each worked on a part of the entire project. The large size and complexity made this project one of the more difficult to manage and advise. Typical projects only have 3-4 students, but this project had 10 students from five different disciplines. This paper describes the difference of this large project compared to typical projects, and the challenges encountered. It also describes how the systems engineering approach was successfully implemented so that the students were able to meet nearly all of the project requirements.

  3. Systems, methods and computer-readable media to model kinetic performance of rechargeable electrochemical devices

    DOEpatents

    Gering, Kevin L.

    2013-01-01

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics. The computing system also analyzes the cell information of the electrochemical cell with a Butler-Volmer (BV) expression modified to determine exchange current density of the electrochemical cell by including kinetic performance information related to pulse-time dependence, electrode surface availability, or a combination thereof. A set of sigmoid-based expressions may be included with the modified-BV expression to determine kinetic performance as a function of pulse time. The determined exchange current density may be used with the modified-BV expression, with or without the sigmoid expressions, to analyze other characteristics of the electrochemical cell. Model parameters can be defined in terms of cell aging, making the overall kinetics model amenable to predictive estimates of cell kinetic performance along the aging timeline.

  4. Estimation of Parameters Obtained by Electrochemical Impedance Spectroscopy on Systems Containing High Capacities

    PubMed Central

    Stević, Zoran; Vujasinović, Mirjana Rajčić; Radunović, Milan

    2009-01-01

    Electrochemical systems with high capacities demand devices for electrochemical impedance spectroscopy (EIS) with ultra-low frequencies (in order of mHz), that are almost impossible to accomplish with analogue techniques, but this becomes possible by using a computer technique and accompanying digital equipment. Recently, an original software and hardware for electrochemical measurements, intended for electrochemical systems exhibiting high capacities, such as supercapacitors, has been developed. One of the included methods is EIS. In this paper, the method of calculation of circuit parameters from an EIS curve is described. The results of testing on a physical model of an electrochemical system, constructed of known elements (including a 1.6 F capacitor) in a defined arrangement, proved the validity of the system and the method. PMID:22400000

  5. Estimation of parameters obtained by electrochemical impedance spectroscopy on systems containing high capacities.

    PubMed

    Stević, Zoran; Vujasinović, Mirjana Rajčić; Radunović, Milan

    2009-01-01

    Electrochemical systems with high capacities demand devices for electrochemical impedance spectroscopy (EIS) with ultra-low frequencies (in order of mHz), that are almost impossible to accomplish with analogue techniques, but this becomes possible by using a computer technique and accompanying digital equipment. Recently, an original software and hardware for electrochemical measurements, intended for electrochemical systems exhibiting high capacities, such as supercapacitors, has been developed. One of the included methods is EIS. In this paper, the method of calculation of circuit parameters from an EIS curve is described. The results of testing on a physical model of an electrochemical system, constructed of known elements (including a 1.6 F capacitor) in a defined arrangement, proved the validity of the system and the method. PMID:22400000

  6. Engine systems analysis results of the Space Shuttle Main Engine redesigned powerhead initial engine level testing

    NASA Astrophysics Data System (ADS)

    Sander, Erik J.; Gosdin, Dennis R.

    1992-07-01

    Engineers regularly analyze SSME ground test and flight data with respect to engine systems performance. Recently, a redesigned SSME powerhead was introduced to engine-level testing in part to increase engine operational margins through optimization of the engine internal environment. This paper presents an overview of the MSFC personnel engine systems analysis results and conclusions reached from initial engine level testing of the redesigned powerhead, and further redesigns incorporated to eliminate accelerated main injector baffle and main combustion chamber hot gas wall degradation. The conclusions are drawn from instrumented engine ground test data and hardware integrity analysis reports and address initial engine test results with respect to the apparent design change effects on engine system and component operation.

  7. Separation system with a sheath-flow supported electrochemical detector

    DOEpatents

    Mathies, Richard A.; Emrich, Charles A.; Singhal, Pankaj; Ertl, Peter

    2008-10-21

    An electrochemical detector including side channels associated with a separation channel of a sample component separation apparatus is provided. The side channels of the detector, in one configuration, provide a sheath-flow for an analyte exiting the separation channel which directs the analyte to the electrically developed electrochemical detector.

  8. Solid electrolyte-electrode system for an electrochemical cell

    DOEpatents

    Tuller, H.L.; Kramer, S.A.; Spears, M.A.

    1995-04-04

    An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided. 17 figures.

  9. Solid electrolyte-electrode system for an electrochemical cell

    DOEpatents

    Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.

    1995-01-01

    An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided.

  10. Cold starting system for alcohol fueled engine

    SciTech Connect

    Powell, T.M.

    1983-04-26

    To restart an alcohol fueled engine at low temperatures, a quantity of liquid ethanol is supplied to a vaporizing chamber before the engine is stopped. When restarting the engine, some of the alcohol in the vaporizing chamber is delivered to an igniter, and the hot gases resulting from the burning alcohol are conducted past the vaporizing chamber to evaporate the liquid alcohol remaining in the vaporizing chamber. The alcohol vapor thus generated is conducted to the engine induction system to start the engine.

  11. Engineering Task Plan for Fourth Generation Hanford Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-06-20

    This Engineering Task Plan (ETP) describes the activities associated with the installation of cabinets containing corrosion monitoring equipment on tanks 241-AN-102 and 241-AN-107. The new cabinets (one per tank) will be installed adjacent to existing corrosion probes already installed in riser WST-RISER-016 on both tanks. The corrosion monitoring equipment to be installed utilizes the technique of electrochemical noise (EN) for monitoring waste tank corrosion. Typically, EN consists of low frequency (4 Hz) and small amplitude signals that are spontaneously generated by electrochemical reactions occurring at corroding or other surfaces. EN analysis is well suited for monitoring and identifying the onset of localized corrosion, and for measuring uniform corrosion rates. A typical EN based corrosion-monitoring system measures instantaneous fluctuations in corrosion current and potential between three nominally identical electrodes of the material of interest immersed in the environment of interest. Time-dependent fluctuations in corrosion current are described by electrochemical current noise, and time-dependent fluctuations of corrosion potential are described by electrochemical noise. The corrosion monitoring systems are designed to detect the onset of localized corrosion phenomena if tank conditions should change to allow these phenomena to occur. In addition to the EN technique, the systems also facilitate the use of the Linear Polarization Resistance (LPR) technique to collect uniform corrosion rate information. LPR measures the linearity at the origin of the polarization curve for overvoltages up to a few millivolts away from the rest potential or natural corrosion potential. The slope of the current vs. voltage plot gives information on uniform corrosion rates.

  12. Systems Metabolic Engineering of Escherichia coli.

    PubMed

    Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

    2016-05-01

    Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass. PMID:27223822

  13. Biodehalogenation: Natural and engineered systems

    SciTech Connect

    Wackett, L.P.; Lange, C.C.; Ornstein, R.L.

    1995-12-31

    Many halogenated organic compounds are environmentally persistent pollutants. Environmental persistence results from the failure of most microorganisms to metabolize organohalides. The authors are studying some of the microbial successes, natural isolates that catalyze carbon-halogen bond cleavage reactions, and subsequent recycling of the compounds into the carbon cycle. Knowledge derived from studies of naturally evolved genes and enzymes provides a basis for directed laboratory evolution of new biological systems that are active with the most environmentally persistent polyhalogenated compounds. The complete metabolism of polyhalogenated compounds typically requires sequential reductive and oxidative dehalogenation reactions. The authors genetically constructed a Pseudomonas putida strain containing seven genes encoding two multicomponent enzyme systems, i.e., cytochrome P450{sub CAM} and toluene dioxygenase. This laboratory-designed metabolic pathway catalyzed sequential reductive and oxidative dehalogenation reactions with fluorinated, chlorinated, and brominated compounds. Current efforts are focused on directed evolution experiments to improve the efficacy of the engineered pathway.

  14. Current developments in electrochemical storage systems for satellites

    NASA Technical Reports Server (NTRS)

    Gutmann, G.

    1986-01-01

    The need for batteries with greater power capacity and service life for power satellites is examined. The Ni/Cd and Ni/H batteries now being used must be upgraded to meet advanced space requirements. Improvements in power capacity, service life, and cycle count for various satellites in LEO and GEO orbits are discussed. The Ni/Cd and Ni/H cell reactions are explained, and the solubility and volume changes for various charged and uncharged masses are described. A chart of the energy content and cycle count for various cell systems is presented, and the factors which cause aging and failure in the Ni/Cd and Ni/H cell systems are discussed. The advantages of the Ni/H battery are given and the need for more developed electrochemical storage systems because of an increase in the mass of satellites is explained. The requirements for space batteries and the work currently done by NASA and West Germany on advanced batteries are discussed.

  15. Engine valve operating system for an internal combustion engine

    SciTech Connect

    Hara, S.; Matsumoto, Y.; Matayoshi, Y.

    1986-02-04

    This patent describes an engine valve operating system for an internal combustion engine. The system consists of: a driving cam rotatable in timed relation to engine revolution; a rocker arm having a first end section drivingly connected to an engine valve and a second end section drivably connected to the driving cam; an elongated lever pivoted at a first end section and disposed in fulcrum contact with the rocker arm; an apparatus for biasing the rocker arm and the lever away from each other; and a hydraulic actuator having a movable end section which is in contact with a second end section of the lever and movable to control the pivotal location of the lever in accordance with an engine operating condition.

  16. Systems engineering in the global environment : a wicked future.

    SciTech Connect

    Griego, Regina M.

    2010-12-01

    This presentation discusses the following questions: (1) What are the Global Problems that require Systems Engineering; (2) Where is Systems Engineering going; (3) What are the boundaries of Systems Engineering; (4) What is the distinction between Systems Thinking and Systems Engineering; (5) Can we use Systems Engineering on Complex Systems; and (6) Can we use Systems Engineering on Wicked Problems?

  17. Electrochemical Double Layered Capacitor Development and Implementation System

    NASA Astrophysics Data System (ADS)

    Strunk, Gavin P.

    Electrochemical Double Layered Capacitors (EDLC's) are becoming a more popular topic of research for hybrid power systems, especially vehicles. They are known for their high power density, high cycle life, low internal resistance, and wider operating temperature compared to batteries. They are rarely used as a standalone power source; however, because of their lack of energy density compared to batteries and fuel cells. Researchers are now discovering the benefits of using them in hybrid systems. The increased complexity of a hybrid power source presents many challenges. A major drawback of this complexity is the lack of design tools to assist a designer in translating a simulation all the way to a full scale implementation. A full spectrum of tools was designed to assist designers at all stages of implementation including: single cell testing, a multi-cell management system, and a full scale vehicle data acquisition system to monitor performance. First, the full scale vehicle data acquisition is described. The system is isolated from the electric shuttle bus it was tested on to allow the system to be ported to other vehicles and applications. This was done to modularize the system to characterize a wide variety of full scale applications. Next, a single cell test system was designed that allows the designer to characterize cell specifications, as well as, test control and safety systems in a controlled environment. The goal is to ensure safety systems can be thoroughly tested to ensure robustness as the bank is scaled up. This system also includes simulation models that provide examples of using the simulation to predict the behavior of a cell and the test system to validate the results of the simulation. This information is then used by the designer to more effectively design sensor ranges for the bank. Finally, a multi-cell EDLC management system was designed to implement a bank. It incorporates 12 series EDLC cells per control module, and the modular design

  18. Integrating system safety into the basic systems engineering process

    NASA Technical Reports Server (NTRS)

    Griswold, J. W.

    1971-01-01

    The basic elements of a systems engineering process are given along with a detailed description of what the safety system requires from the systems engineering process. Also discussed is the safety that the system provides to other subfunctions of systems engineering.

  19. RDD-100 and the systems engineering process

    NASA Technical Reports Server (NTRS)

    Averill, Robert D.

    1994-01-01

    An effective systems engineering approach applied through the project life cycle can help Langley produce a better product. This paper demonstrates how an enhanced systems engineering process for in-house flight projects assures that each system will achieve its goals with quality performance and within planned budgets and schedules. This paper also describes how the systems engineering process can be used in combination with available software tools.

  20. Engine sealing and lubrication systems

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1975-01-01

    Engine sealing programs are discussed which are directed toward the two major classes of engine seals: engine shaft seals and primary gas path seals. In addition, some concepts and results from fundamental lubrication research, as it pertains to the lubrication of bearings, are presented.

  1. Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes

    NASA Astrophysics Data System (ADS)

    Oleshko, Vladimir P.; Lam, Thomas; Ruzmetov, Dmitry; Haney, Paul; Lezec, Henri J.; Davydov, Albert V.; Krylyuk, Sergiy; Cumings, John; Talin, A. Alec

    2014-09-01

    Complex interfacial phenomena and phase transformations that govern the operation of Li-ion batteries require detailed nanoscale 3D structural and compositional characterization that can be directly related to their capacity and electrical transport properties. For this purpose, we have designed model miniature all solid-state radial heterostructure Li-ion batteries composed of LiCoO2 cathode, LiPON electrolyte and amorphous Si anode shells, which were deposited around metallized high-aspect-ratio Si nanowires as a scaffolding core. Such diagnostic batteries, the smallest, complete secondary Li-ion batteries realized to date, were specifically designed for in situ electrical testing in a field-emission scanning electron microscope and/or transmission electron microscope. The results of electrochemical testing were described in detail in a previous publication (Nano Lett., 2012, 12, 505-511). The model Li-ion batteries allow analysis of the correlations between electrochemical properties and their structural evolution during cycling in various imaging, diffraction and spectroscopic modes down to the atomic level. Employing multimode analytical scanning/transmission electron microscopy imaging coupled with correlative multivariate statistical analysis and tomography, we have analyzed and quantified the 3D morphological and structural arrangement of the batteries, including textured platelet-like LiCoO2 nanocrystallites, buried electrode-electrolyte interfaces and hidden internal defects to clarify effects of scaling on a battery's electrochemical performance. Characterization of the nanoscale interfacial processes using model heterostructure nanowire-based Li-ion batteries provides useful guidelines for engineering of prospective nano-sized building blocks in future electrochemical energy storage systems.Complex interfacial phenomena and phase transformations that govern the operation of Li-ion batteries require detailed nanoscale 3D structural and compositional

  2. Reproducibility of electrochemical noise data from coated metal systems

    SciTech Connect

    Bierwagen, G.P.; Mills, D.J.; Tallman, D.E.; Skerry, B.S.

    1996-12-31

    The use of electrochemical noise (ECN) as a method to characterize the corrosion-protection properties of organic coatings on metal substrates was pioneered by Skerry and Eden, and since then has been used by others as a probe for coating metal corrosion studies. However, no statistical examination of the reproducibility of the data from such measurements has been published. In the data the authors present, they have done a systematic analysis of important experimental variables in such systems. They have examined the method for accuracy and reproducibility with respect to sample preparation, sample immersion, and metal substrate preparation. They have taken several marine coatings systems typical of US Navy use, prepared duplicate samples of coating metal systems, and examined them under the same immersion exposure. The variables they considered for reproducibility are paint application (in three-coat systems), metal panel preparation (grit-blasted steel), and immersion conditions. The authors present ECN data with respect to immersion time on the values of noise voltage standard deviation {sigma}{sub V}, noise current standard deviation {sigma}{sub I}, and the noise resistance R{sub n} as given by {sigma}{sub V}/{sigma}{sub I}. The variation among supposedly identical sample pairs in identical immersion monitored under identical conditions is presented. The statistics of the time records of the data are considered, and the variations with respect to specific coatings classes are also considered within the limits of the data. Based on these data, comments concerning ECN on coated metal systems as a predictive test method are presented along with special considerations that must be made to properly use the method for coating ranking and lifetime prediction.

  3. Automotive Stirling engine system component review

    NASA Technical Reports Server (NTRS)

    Hindes, Chip; Stotts, Robert

    1987-01-01

    The design and testing of the power and combustion control system for the basic Stirling engine, Mod II, are examined. The power control system is concerned with transparent operation, and the Mod II uses engine working gas pressure variation to control the power output of the engine. The main components of the power control system, the power control valve, the pump-down system, and the hydrogen stable system, are described. The combustion control system consists of a combustion air supply system and an air/fuel ratio control system, and the system is to maintain constant heater head temperature, and to maximize combustion efficiency and to minimize exhaust emissions.

  4. Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes.

    PubMed

    Oleshko, Vladimir P; Lam, Thomas; Ruzmetov, Dmitry; Haney, Paul; Lezec, Henri J; Davydov, Albert V; Krylyuk, Sergiy; Cumings, John; Talin, A Alec

    2014-10-21

    Complex interfacial phenomena and phase transformations that govern the operation of Li-ion batteries require detailed nanoscale 3D structural and compositional characterization that can be directly related to their capacity and electrical transport properties. For this purpose, we have designed model miniature all solid-state radial heterostructure Li-ion batteries composed of LiCoO2 cathode, LiPON electrolyte and amorphous Si anode shells, which were deposited around metallized high-aspect-ratio Si nanowires as a scaffolding core. Such diagnostic batteries, the smallest, complete secondary Li-ion batteries realized to date, were specifically designed for in situ electrical testing in a field-emission scanning electron microscope and/or transmission electron microscope. The results of electrochemical testing were described in detail in a previous publication (Nano Lett., 2012, 12, 505-511). The model Li-ion batteries allow analysis of the correlations between electrochemical properties and their structural evolution during cycling in various imaging, diffraction and spectroscopic modes down to the atomic level. Employing multimode analytical scanning/transmission electron microscopy imaging coupled with correlative multivariate statistical analysis and tomography, we have analyzed and quantified the 3D morphological and structural arrangement of the batteries, including textured platelet-like LiCoO2 nanocrystallites, buried electrode-electrolyte interfaces and hidden internal defects to clarify effects of scaling on a battery's electrochemical performance. Characterization of the nanoscale interfacial processes using model heterostructure nanowire-based Li-ion batteries provides useful guidelines for engineering of prospective nano-sized building blocks in future electrochemical energy storage systems. PMID:25157420

  5. Relations between information system engineering and software engineering

    NASA Technical Reports Server (NTRS)

    Callender, E. D.; Hartsough, C.; Morris, R. V.

    1981-01-01

    This paper examines some of the relations between information system engineering and software engineering. A model for the development process of an information system is presented that focuses on problems common to both disciplines. The concepts of complexity, multiplicity of view, distortion in communication, and concurrency and iteration in implementation are treated. A set of design constructs for the description of an information system is presented. The role of project management is treated. The issue of how to characterize requirements analysis is answered by making it a design activity from the point of view of a user of the product system.

  6. Earth Systems Science and Engineering

    SciTech Connect

    Rotman, D A

    2006-02-21

    Providing the essential energy and water systems to support human needs while understanding and addressing their environmental consequences is a watershed problem for the 21st century. The LLNL Earth System Science and Engineering Program seeks to provide the scientific understanding and technological expertise to help provide solutions at both global and regional scales. Our work is highly collaborative with universities, laboratories and industrial partners across the world and involves observational data, laboratory experiments, and numerical simulations. The energy systems we have enjoyed for the last 100 years have resulted in the advanced standard of living in the developed world and a major emerging problem with climate change. Now we face a simultaneous realization that our reliance on fossil fuels is a source of conflict and economic disruption as well as causing potentially abrupt, even catastrophic global climate change. The climate and energy problem is perhaps the greatest challenge ever faced by mankind. Fossil fuel remains the least expensive and most available source of energy and the basis of our economy. The use of fossil fuels, especially over the last 100 years has led to a 30% increase in CO{sub 2} in the atmosphere. The problem is growing. The population of the Earth will increase by several billion people in the next 50 years. If economic growth is to continue, the demand for energy is estimated to approximately double in the next 50 years so that we will need approximately 10 TW more energy than the 15 TW we use now. Much of this demand will come from the developing world where most of the population growth will occur and where advanced energy technology is not generally used. The problem affects and is affected by a complex system of systems. The climate and energy problem will affect resources, social structure and the probability of increased conflict. No one person, no one nation, no one technology can solve the problem. There is no

  7. An Electrochemical Impedance Spectroscopy System for Monitoring Pineapple Waste Saccharification

    PubMed Central

    Conesa, Claudia; Ibáñez Civera, Javier; Seguí, Lucía; Fito, Pedro; Laguarda-Miró, Nicolás

    2016-01-01

    Electrochemical impedance spectroscopy (EIS) has been used for monitoring the enzymatic pineapple waste hydrolysis process. The system employed consists of a device called Advanced Voltammetry, Impedance Spectroscopy & Potentiometry Analyzer (AVISPA) equipped with a specific software application and a stainless steel double needle electrode. EIS measurements were conducted at different saccharification time intervals: 0, 0.75, 1.5, 6, 12 and 24 h. Partial least squares (PLS) were used to model the relationship between the EIS measurements and the sugar determination by HPAEC-PAD. On the other hand, artificial neural networks: (multilayer feed forward architecture with quick propagation training algorithm and logistic-type transfer functions) gave the best results as predictive models for glucose, fructose, sucrose and total sugars. Coefficients of determination (R2) and root mean square errors of prediction (RMSEP) were determined as R2 > 0.944 and RMSEP < 1.782 for PLS and R2 > 0.973 and RMSEP < 0.486 for artificial neural networks (ANNs), respectively. Therefore, a combination of both an EIS-based technique and ANN models is suggested as a promising alternative to the traditional laboratory techniques for monitoring the pineapple waste saccharification step. PMID:26861317

  8. An Electrochemical Impedance Spectroscopy System for Monitoring Pineapple Waste Saccharification.

    PubMed

    Conesa, Claudia; Ibáñez Civera, Javier; Seguí, Lucía; Fito, Pedro; Laguarda-Miró, Nicolás

    2016-01-01

    Electrochemical impedance spectroscopy (EIS) has been used for monitoring the enzymatic pineapple waste hydrolysis process. The system employed consists of a device called Advanced Voltammetry, Impedance Spectroscopy & Potentiometry Analyzer (AVISPA) equipped with a specific software application and a stainless steel double needle electrode. EIS measurements were conducted at different saccharification time intervals: 0, 0.75, 1.5, 6, 12 and 24 h. Partial least squares (PLS) were used to model the relationship between the EIS measurements and the sugar determination by HPAEC-PAD. On the other hand, artificial neural networks: (multilayer feed forward architecture with quick propagation training algorithm and logistic-type transfer functions) gave the best results as predictive models for glucose, fructose, sucrose and total sugars. Coefficients of determination (R²) and root mean square errors of prediction (RMSEP) were determined as R² > 0.944 and RMSEP < 1.782 for PLS and R² > 0.973 and RMSEP < 0.486 for artificial neural networks (ANNs), respectively. Therefore, a combination of both an EIS-based technique and ANN models is suggested as a promising alternative to the traditional laboratory techniques for monitoring the pineapple waste saccharification step. PMID:26861317

  9. A road map for implementing systems engineering

    SciTech Connect

    Dean, F.F.; Bentz, B.; Bahill, A.T.

    1997-02-01

    Studies by academia, industry, and government indicate that applying a sound systems engineering process to development programs is an important tool for preventing cost and schedule overruns and performance deficiencies. There is an enormous body of systems engineering knowledge. Where does one start? How can the principles of systems engineering be applied in the Sandia environment? This road map is intended to be an aid to answering these questions.

  10. Engine Structures Modeling Software System (ESMOSS)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Engine Structures Modeling Software System (ESMOSS) is the development of a specialized software system for the construction of geometric descriptive and discrete analytical models of engine parts, components, and substructures which can be transferred to finite element analysis programs such as NASTRAN. The NASA Lewis Engine Structures Program is concerned with the development of technology for the rational structural design and analysis of advanced gas turbine engines with emphasis on advanced structural analysis, structural dynamics, structural aspects of aeroelasticity, and life prediction. Fundamental and common to all of these developments is the need for geometric and analytical model descriptions at various engine assembly levels which are generated using ESMOSS.

  11. ATK Launch Systems Engineering NASA Programs Engineering Examples

    NASA Technical Reports Server (NTRS)

    Richardson, David

    2007-01-01

    This presentation provides an overview of the work done at ATK Launch Systems with and indication of how engineering knowledge can be applied to several real world problems. All material in the presentation has been screened to meet ITAR restrictions. The information provided is a compilation of general engineering knowledge and material available in the public domain. The presentation provides an overview of ATK Launch Systems and NASA programs. Some discussion is provided about the types of engineering conducted at the Promontory plant with added detail about RSRM nozzle engineering. Some brief examples of examples of nozzle technical issues with regard to adhesives and phenolics are shared. These technical issue discussions are based on material available in the public domain.

  12. CAESY - COMPUTER AIDED ENGINEERING SYSTEM

    NASA Technical Reports Server (NTRS)

    Wette, M. R.

    1994-01-01

    Many developers of software and algorithms for control system design have recognized that current tools have limits in both flexibility and efficiency. Many forces drive the development of new tools including the desire to make complex system modeling design and analysis easier and the need for quicker turnaround time in analysis and design. Other considerations include the desire to make use of advanced computer architectures to help in control system design, adopt new methodologies in control, and integrate design processes (e.g., structure, control, optics). CAESY was developed to provide a means to evaluate methods for dealing with user needs in computer-aided control system design. It is an interpreter for performing engineering calculations and incorporates features of both Ada and MATLAB. It is designed to be reasonably flexible and powerful. CAESY includes internally defined functions and procedures, as well as user defined ones. Support for matrix calculations is provided in the same manner as MATLAB. However, the development of CAESY is a research project, and while it provides some features which are not found in commercially sold tools, it does not exhibit the robustness that many commercially developed tools provide. CAESY is written in C-language for use on Sun4 series computers running SunOS 4.1.1 and later. The program is designed to optionally use the LAPACK math library. The LAPACK math routines are available through anonymous ftp from research.att.com. CAESY requires 4Mb of RAM for execution. The standard distribution medium is a .25 inch streaming magnetic tape cartridge (QIC-24) in UNIX tar format. CAESY was developed in 1993 and is a copyrighted work with all copyright vested in NASA.

  13. Model-Based Systems Engineering in Concurrent Engineering Centers

    NASA Technical Reports Server (NTRS)

    Iwata, Curtis; Infeld, Samantha; Bracken, Jennifer Medlin; McGuire; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a focused design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  14. Model-Based Systems Engineering in Concurrent Engineering Centers

    NASA Technical Reports Server (NTRS)

    Iwata, Curtis; Infeld, Samatha; Bracken, Jennifer Medlin; McGuire, Melissa; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  15. Tank waste remediation system engineering plan

    SciTech Connect

    Rifaey, S.H.

    1998-01-09

    This Engineering Plan describes the engineering process and controls that will be in place to support the Technical Baseline definition and manage its evolution and implementation to the field operations. This plan provides the vision for the engineering required to support the retrieval and disposal mission through Phase 1 and 2, which includes integrated data management of the Technical Baseline. Further, this plan describes the approach for moving from the ``as is`` condition of engineering practice, systems, and facilities to the desired ``to be`` configuration. To make this transition, Tank Waste Remediation System (TWRS) Engineering will become a center of excellence for TWRS which,will perform engineering in the most effective manner to meet the mission. TWRS engineering will process deviations from sitewide systems if necessary to meet the mission most effectively.

  16. Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold

    DOEpatents

    Farmer, Joseph C; Stadermann, Michael

    2013-11-12

    A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.

  17. Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold

    DOEpatents

    Farmer, Joseph Collin; Stadermann, Michael

    2014-07-15

    A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.

  18. System Engineering of Autonomous Space Vehicles

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Johnson, Stephen B.; Trevino, Luis

    2014-01-01

    Human exploration of the solar system requires fully autonomous systems when travelling more than 5 light minutes from Earth. This autonomy is necessary to manage a large, complex spacecraft with limited crew members and skills available. The communication latency requires the vehicle to deal with events with only limited crew interaction in most cases. The engineering of these systems requires an extensive knowledge of the spacecraft systems, information theory, and autonomous algorithm characteristics. The characteristics of the spacecraft systems must be matched with the autonomous algorithm characteristics to reliably monitor and control the system. This presents a large system engineering problem. Recent work on product-focused, elegant system engineering will be applied to this application, looking at the full autonomy stack, the matching of autonomous systems to spacecraft systems, and the integration of different types of algorithms. Each of these areas will be outlined and a general approach defined for system engineering to provide the optimal solution to the given application context.

  19. Computer simulation of engine systems

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1980-01-01

    The use of computerized simulations of the steady state and transient performance of jet engines throughout the flight regime is discussed. In addition, installation effects on thrust and specific fuel consumption is accounted for as well as engine weight, dimensions and cost. The availability throughout the government and industry of analytical methods for calculating these quantities are pointed out.

  20. Engine system assessment study using Martian propellants

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  1. Advancing Systems Engineering Excellence: The Marshall Systems Engineering Leadership Development Program

    NASA Technical Reports Server (NTRS)

    Hall, Philip; Whitfield, Susan

    2011-01-01

    As NASA undertakes increasingly complex projects, the need for expert systems engineers and leaders in systems engineering is becoming more pronounced. As a result of this issue, the Agency has undertaken an initiative to develop more systems engineering leaders through its Systems Engineering Leadership Development Program; however, the NASA Office of the Chief Engineer has also called on the field Centers to develop mechanisms to strengthen their expertise in systems engineering locally. In response to this call, Marshall Space Flight Center (MSFC) has developed a comprehensive development program for aspiring systems engineers and systems engineering leaders. This presentation will summarize the two-level program, which consists of a combination of training courses and on-the-job, developmental training assignments at the Center to help develop stronger expertise in systems engineering and technical leadership. In addition, it will focus on the success the program has had in its pilot year. The program hosted a formal kickoff event for Level I on October 13, 2009. The first class includes 42 participants from across MSFC and Michoud Assembly Facility (MAF). A formal call for Level II is forthcoming. With the new Agency focus on research and development of new technologies, having a strong pool of well-trained systems engineers is becoming increasingly more critical. Programs such as the Marshall Systems Engineering Leadership Development Program, as well as those developed at other Centers, help ensure that there is an upcoming generation of trained systems engineers and systems engineering leaders to meet future design challenges.

  2. System Study for Axial Vane Engine Technology

    NASA Technical Reports Server (NTRS)

    Badley, Patrick R.; Smith, Michael R.; Gould, Cedric O.

    2008-01-01

    The purpose of this engine feasibility study was to determine the benefits that can be achieved by incorporating positive displacement axial vane compression and expansion stages into high bypass turbofan engines. These positive-displacement stages would replace some or all of the conventional compressor and turbine stages in the turbine engine, but not the fan. The study considered combustion occurring internal to an axial vane component (i.e., Diesel engine replacing the standard turbine engine combustor, burner, and turbine); and external continuous flow combustion with an axial vane compressor and an axial vane turbine replacing conventional compressor and turbine systems.

  3. Dynamic systems-engineering process - The application of concurrent engineering

    NASA Technical Reports Server (NTRS)

    Wiskerchen, Michael J.; Pittman, R. Bruce

    1989-01-01

    A system engineering methodology is described which enables users, particulary NASA and DOD, to accommodate changing needs; incorporate emerging technologies; identify, quantify, and manage system risks; manage evolving functional requirements; track the changing environment; and reduce system life-cycle costs. The approach is a concurrent, dynamic one which starts by constructing a performance model defining the required system functions and the interrelationships. A detailed probabilistic risk assessment of the system elements and their interrelationships is performed, and quantitative analysis of the reliability and maintainability of an engineering system allows its different technical and process failure modes to be identified and their probabilities to be computed. Decision makers can choose technical solutions that maximize an objective function and minimize the probability of failure under resource constraints.

  4. Engine health monitoring: An advanced system

    NASA Technical Reports Server (NTRS)

    Dyson, R. J. E.

    1981-01-01

    The advanced propulsion monitoring system is described. The system was developed in order to fulfill a growing need for effective engine health monitoring. This need is generated by military requirements for increased performance and efficiency in more complex propulsion systems, while maintaining or improving the cost to operate. This program represents a vital technological step in the advancement of the state of the art for monitoring systems in terms of reliability, flexibility, accuracy, and provision of user oriented results. It draws heavily on the technology and control theory developed for modern, complex, electronically controlled engines and utilizes engine information which is a by-product of such a system.

  5. Modern Medical Engineering and Health Information Systems

    ERIC Educational Resources Information Center

    Davis, John F.

    1975-01-01

    Describes the impact of medical engineering and system design on hospital design and construction, health care in the home and hospital, equipment design, information systems, and health resources utilization. (GS)

  6. Systems Engineering of Electric and Hybrid Vehicles

    NASA Technical Reports Server (NTRS)

    Kurtz, D. W.; Levin, R. R.

    1986-01-01

    Technical paper notes systems engineering principles applied to development of electric and hybrid vehicles such that system performance requirements support overall program goal of reduced petroleum consumption. Paper discusses iterative design approach dictated by systems analyses. In addition to obvious peformance parameters of range, acceleration rate, and energy consumption, systems engineering also considers such major factors as cost, safety, reliability, comfort, necessary supporting infrastructure, and availability of materials.

  7. Engine Data Interpretation System (EDIS), phase 2

    NASA Technical Reports Server (NTRS)

    Cost, Thomas L.; Hofmann, Martin O.

    1991-01-01

    A prototype of an expert system was developed which applies qualitative constraint-based reasoning to the task of post-test analysis of data resulting from a rocket engine firing. Data anomalies are detected and corresponding faults are diagnosed. Engine behavior is reconstructed using measured data and knowledge about engine behavior. Knowledge about common faults guides but does not restrict the search for the best explanation in terms of hypothesized faults. The system contains domain knowledge about the behavior of common rocket engine components and was configured for use with the Space Shuttle Main Engine (SSME). A graphical user interface allows an expert user to intimately interact with the system during diagnosis. The system was applied to data taken during actual SSME tests where data anomalies were observed.

  8. Visualizing systems engineering data with Java

    SciTech Connect

    Barter, Robert H.; Vinzant, Aleta

    1998-11-10

    Systems Engineers are required to deal with complex sets of data. To be useful, the data must be managed effectively, and presented in meaningful terms to a wide variety of information consumers. Two software patterns are presented as the basis for exploring the visualization of systems engineering data. The Model, View, Controller pattern defines an information management system architecture. The Entity, Relation, Attribute pattern defines the information model. MVC "Views" then form the basis for the user interface between the information consumer and the MVC "Controller"/"Model" combination. A Java tool set is described for exploring alternative views into the underlying complex data structures encountered in systems engineering.

  9. Systems Engineering and Integration for Technology Programs

    NASA Technical Reports Server (NTRS)

    Kennedy, Kruss J.

    2006-01-01

    The Architecture, Habitability & Integration group (AH&I) is a system engineering and integration test team within the NASA Crew and Thermal Systems Division (CTSD) at Johnson Space Center. AH&I identifies and resolves system-level integration issues within the research and technology development community. The timely resolution of these integration issues is fundamental to the development of human system requirements and exploration capability. The integration of the many individual components necessary to construct an artificial environment is difficult. The necessary interactions between individual components and systems must be approached in a piece-wise fashion to achieve repeatable results. A formal systems engineering (SE) approach to define, develop, and integrate quality systems within the life support community has been developed. This approach will allow a Research & Technology Program to systematically approach the development, management, and quality of technology deliverables to the various exploration missions. A tiered system engineering structure has been proposed to implement best systems engineering practices across all development levels from basic research to working assemblies. These practices will be implemented through a management plan across all applicable programs, projects, elements and teams. While many of the engineering practices are common to other industries, the implementation is specific to technology development. An accounting of the systems engineering management philosophy will be discussed and the associated programmatic processes will be presented.

  10. Congeneration system with a Stirling engine

    SciTech Connect

    Meijer, R.J.; Meijer, E.J.; Godett, T.M.

    1991-12-24

    This patent describes a cogeneration system for producing process heat for useful purposes and electric energy. It comprises an electric generator; a Stirling cycle engine having an output shaft operatively coupled to the generator for driving the generator, the engine including at least one internal fuel combustor; means for circulating a cooling liquid about the generator and engine to extract heat therefrom; an exhaust system coupled with the engine for exhausting combustion gases from the engine, the exhaust system including a condensing heat exchanger for cooling the combustion gases below the condensing, temperature of the water vapor in the exhaust gases; means for directing the cooling liquid around the condensing heat exchanger to extract heat therefrom and heat the liquid; and means for directing the cooling liquid for useful purposes.

  11. Systems engineering: A formal approach. Part 1: System concepts

    NASA Astrophysics Data System (ADS)

    Vanhee, K. M.

    1993-03-01

    Engineering is the scientific discipline focused on the creation of new artifacts that are supposed to be of some use to our society. Different types of artifacts require different engineering approaches. However, in all these disciplines the development of a new artifact is divided into stages. Three stages can always be recognized: Analysis, Design, and Realization. The book considers only the first two stages of the development process. It focuses on a specific type of artifacts, called discrete dynamic systems. These systems consist of active components of actors that consume and produce passive components or tokens. Three subtypes are studied in more detail: business systems (like a factory or restaurant), information systems (whether automated or not), and automated systems (systems that are controlled by an automated information system). The first subtype is studied by industrial engineers, the last by software engineers and electrical engineers, whereas the second is a battlefield for all three disciplines. The union of these disciplines is called systems engineering.

  12. Process Systems Engineering Education: Learning by Research

    ERIC Educational Resources Information Center

    Abbas, A.; Alhammadi, H. Y.; Romagnoli, J. A.

    2009-01-01

    In this paper, we discuss our approach in teaching the final-year course Process Systems Engineering. Students are given ownership of the course by transferring to them the responsibility of learning. A project-based group environment stimulates learning while solving a real engineering problem. We discuss postgraduate student involvement and how…

  13. Performance Engineering as an Expert System.

    ERIC Educational Resources Information Center

    Harmon, Paul

    1984-01-01

    Considers three powerful techniques--heuristics, context trees, and search via backward chaining--that a knowledge engineer might employ to develop an expert system to automate performance engineering, i.e., the branch of instructional technology that focuses on the problems of business and industry. (MBR)

  14. System safety in Stirling engine development

    NASA Technical Reports Server (NTRS)

    Bankaitis, H.

    1981-01-01

    The DOE/NASA Stirling Engine Project Office has required that contractors make safety considerations an integral part of all phases of the Stirling engine development program. As an integral part of each engine design subtask, analyses are evolved to determine possible modes of failure. The accepted system safety analysis techniques (Fault Tree, FMEA, Hazards Analysis, etc.) are applied in various degrees of extent at the system, subsystem and component levels. The primary objectives are to identify critical failure areas, to enable removal of susceptibility to such failures or their effects from the system and to minimize risk.

  15. Aircraft engine mathematical model - linear system approach

    NASA Astrophysics Data System (ADS)

    Rotaru, Constantin; Roateşi, Simona; Cîrciu, Ionicǎ

    2016-06-01

    This paper examines a simplified mathematical model of the aircraft engine, based on the theory of linear and nonlinear systems. The dynamics of the engine was represented by a linear, time variant model, near a nominal operating point within a finite time interval. The linearized equations were expressed in a matrix form, suitable for the incorporation in the MAPLE program solver. The behavior of the engine was included in terms of variation of the rotational speed following a deflection of the throttle. The engine inlet parameters can cover a wide range of altitude and Mach numbers.

  16. System engineering toolbox for design-oriented engineers

    NASA Technical Reports Server (NTRS)

    Goldberg, B. E.; Everhart, K.; Stevens, R.; Babbitt, N., III; Clemens, P.; Stout, L.

    1994-01-01

    This system engineering toolbox is designed to provide tools and methodologies to the design-oriented systems engineer. A tool is defined as a set of procedures to accomplish a specific function. A methodology is defined as a collection of tools, rules, and postulates to accomplish a purpose. For each concept addressed in the toolbox, the following information is provided: (1) description, (2) application, (3) procedures, (4) examples, if practical, (5) advantages, (6) limitations, and (7) bibliography and/or references. The scope of the document includes concept development tools, system safety and reliability tools, design-related analytical tools, graphical data interpretation tools, a brief description of common statistical tools and methodologies, so-called total quality management tools, and trend analysis tools. Both relationship to project phase and primary functional usage of the tools are also delineated. The toolbox also includes a case study for illustrative purposes. Fifty-five tools are delineated in the text.

  17. Application of electrochemical energy storage in solar thermal electric generation systems

    NASA Technical Reports Server (NTRS)

    Das, R.; Krauthamer, S.; Frank, H.

    1982-01-01

    This paper assesses the status, cost, and performance of existing electrochemical energy storage systems, and projects the cost, performance, and availability of advanced storage systems for application in terrestrial solar thermal electric generation. A 10 MWe solar plant with five hours of storage is considered and the cost of delivered energy is computed for sixteen different storage systems. The results indicate that the five most attractive electrochemical storage systems use the following battery types: zinc-bromine (Exxon), iron-chromium redox (NASA/Lewis Research Center, LeRC), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (Energy Development Associates, EDA).

  18. A mechanistic model for electrochemical nutrient recovery systems.

    PubMed

    Thompson Brewster, Emma; Mehta, Chirag M; Radjenovic, Jelena; Batstone, Damien J

    2016-05-01

    Electrochemical membrane technologies such as electrodialysis have been identified as key technologies to enable nutrient recovery from wastewater. However, current electrochemical models are focused on simpler solutions than wastewater and omit key outputs such as pH, or total cell potential. A combined physico-chemical and electrochemical model was developed which includes the mechanisms of competitive transport of ions, implicit inclusion of H(+) and OH(-), pH (including ionic activity and ion pairing), different factors contributing to total cell potential and a novel method for ion exchange membrane transport. The model outputs compare well with measurements from experiments and simulate secondary effects such as electrode reactions and current leakage. Results found that membrane, rather than boundary layer or bulk resistance was the major contributor to potential drop, and that apparent boundary layers were relatively thick (3 ± 1 mm). Non-ideal solution effects such as ion-pairing and ionic activity had a major impact, particularly on multi-valent Ca(2+) ions, which enhances the capability of electrodialysis to recover monovalent nutrient ions such as K(+) and NH4(+). Decreased resistivity of ion exchange membranes to specific ions (for example, in this case nitrate) could also be detected. The methods here are validated using a comparatively simple synthetic solution of five ionic components, but are able to be easily scaled for a more complex solution, and are also compatible with additional mechanisms such as precipitation, fouling, and scaling. PMID:26945961

  19. A systems engineering primer for every engineer and scientist

    SciTech Connect

    Edwards, William R.

    2001-12-10

    The Systems Engineering (SE) staff at LBNL has generated the following artifacts to assist projects with implementing a systems approach: (1) The present document that focuses on the what, why, and when of SE. It also provides a simple case-study to illustrate several SE tasks. (2) A web site with primary emphasis on the project life-cycle and workflow, (http://www-eng.LBNL.gov/Systems/index.html). It includes: SE guidelines and principles; A list of in-house tools; Templates; Case studies with ''how to'' examples; and Links to useful SE material. These sources are living documents to be updated as necessary. The viewpoint adopted in this document is that what LBNL engineers and scientists need is a set of principles and guiding practices for developing R and D systems rather than a ''cookbook''. There are many excellent ''how to'' resources such as the ''INCOSE Systems Engineering Handbook'' to guide those in search of more details. The SE staff is another resource available to consult and support projects. This document specifies SE principles and activities that are applicable to all LBNL projects independent of their specific differences. Each project should tailor the SE implementation to meet its individual needs and culture including project-specific resources, procedures, products, and tools.

  20. Intelligent Engine Systems: Adaptive Control

    NASA Technical Reports Server (NTRS)

    Gibson, Nathan

    2008-01-01

    We have studied the application of the baseline Model Predictive Control (MPC) algorithm to the control of main fuel flow rate (WF36), variable bleed valve (AE24) and variable stator vane (STP25) control of a simulated high-bypass turbofan engine. Using reference trajectories for thrust and turbine inlet temperature (T41) generated by a simulated new engine, we have examined MPC for tracking these two reference outputs while controlling a deteriorated engine. We have examined the results of MPC control for six different transients: two idle-to-takeoff transients at sea level static (SLS) conditions, one takeoff-to-idle transient at SLS, a Bode power command and reverse Bode power command at 20,000 ft/Mach 0.5, and a reverse Bode transient at 35,000 ft/Mach 0.84. For all cases, our primary focus was on the computational effort required by MPC for varying MPC update rates, control horizons, and prediction horizons. We have also considered the effects of these MPC parameters on the performance of the control, with special emphasis on the thrust tracking error, the peak T41, and the sizes of violations of the constraints on the problem, primarily the booster stall margin limit, which for most cases is the lone constraint that is violated with any frequency.

  1. AAHM 2012: Systems Engineer Leading the Way

    NASA Video Gallery

    Marco Midon, who is visually impaired, is highlighted for NASA's Black History Month. He is the Lead Systems Engineer who oversees the design and implementation of NASA ground stations in the area ...

  2. Engines-only flight control system

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W. (Inventor); Gilyard, Glenn B (Inventor); Conley, Joseph L. (Inventor); Stewart, James F. (Inventor); Fullerton, Charles G. (Inventor)

    1994-01-01

    A backup flight control system for controlling the flightpath of a multi-engine airplane using the main drive engines is introduced. The backup flight control system comprises an input device for generating a control command indicative of a desired flightpath, a feedback sensor for generating a feedback signal indicative of at least one of pitch rate, pitch attitude, roll rate and roll attitude, and a control device for changing the output power of at least one of the main drive engines on each side of the airplane in response to the control command and the feedback signal.

  3. Implementing Systems Engineering on a CERCLA Project

    SciTech Connect

    Beitel, George Alois

    1999-06-01

    The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), enacted in 1980, provides a regulatory and legal mechanism to reduce risks from prior disposal of hazardous and toxic chemicals. Regulations, Standards, and Guidelines have been published to further define the CERCLA Process. The OU 7-10 Staged Interim Action Project at the Idaho National Engineering and Environmental Laboratory (INEEL) is a CERCLA project working to remediate the pre-1970 disposal pit in which transuranic materials have been disposed. This paper analyzes the CERCLA process from a systems engineering perspective and describes how systems engineering is implemented on this project.

  4. Stirling cycle engine and refrigeration systems

    NASA Technical Reports Server (NTRS)

    Higa, W. H. (Inventor)

    1976-01-01

    A Stirling cycle heat engine is disclosed in which displacer motion is controlled as a function of the working fluid pressure P sub 1 and a substantially constant pressure P sub 0. The heat engine includes an auxiliary chamber at the constant pressure P sub 0. An end surface of a displacer piston is disposed in the auxiliary chamber. During the compression portion of the engine cycle when P sub 1 rises above P sub 0 the displacer forces the working fluid to pass from the cold chamber to the hot chamber of the engine. During the expansion portion of the engine cycle the heated working fluid in the hot chamber does work by pushing down on the engine's drive piston. As the working fluid pressure P sub 1 drops below P sub 0 the displacer forces most of the working fluid in the hot chamber to pass through the regenerator to the cold chamber. The engine is easily combinable with a refrigeration section to provide a refrigeration system in which the engine's single drive piston serves both the engine and the refrigeration section.

  5. Complex Adaptive Systems of Systems (CASOS) engineering environment.

    SciTech Connect

    Detry, Richard Joseph; Linebarger, John Michael; Finley, Patrick D.; Maffitt, S. Louise; Glass, Robert John, Jr.; Beyeler, Walter Eugene; Ames, Arlo Leroy

    2012-02-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex physical-socio-technical systems which we must understand to design a secure future for the nation. The Phoenix initiative implements CASoS Engineering principles combining the bottom up Complex Systems and Complex Adaptive Systems view with the top down Systems Engineering and System-of-Systems view. CASoS Engineering theory and practice must be conducted together to develop a discipline that is grounded in reality, extends our understanding of how CASoS behave and allows us to better control the outcomes. The pull of applications (real world problems) is critical to this effort, as is the articulation of a CASoS Engineering Framework that grounds an engineering approach in the theory of complex adaptive systems of systems. Successful application of the CASoS Engineering Framework requires modeling, simulation and analysis (MS and A) capabilities and the cultivation of a CASoS Engineering Community of Practice through knowledge sharing and facilitation. The CASoS Engineering Environment, itself a complex adaptive system of systems, constitutes the two platforms that provide these capabilities.

  6. A Systems-Level Perspective on Engine Ice Accretion

    NASA Technical Reports Server (NTRS)

    May, Ryan David; Guo, Ten-Huei; Simon, Donald L.

    2012-01-01

    Talk covers: (1) Problem of Engine Power Loss;(2) Modeling Engine Icing Effects; (3) Simulation of Engine Rollback; (4) Icing/Engine Control System Interaction; (5) Detection of Ice Accretion; (6) Potential Mitigation Strategies.

  7. Engineering management of large scale systems

    NASA Technical Reports Server (NTRS)

    Sanders, Serita; Gill, Tepper L.; Paul, Arthur S.

    1989-01-01

    The organization of high technology and engineering problem solving, has given rise to an emerging concept. Reasoning principles for integrating traditional engineering problem solving with system theory, management sciences, behavioral decision theory, and planning and design approaches can be incorporated into a methodological approach to solving problems with a long range perspective. Long range planning has a great potential to improve productivity by using a systematic and organized approach. Thus, efficiency and cost effectiveness are the driving forces in promoting the organization of engineering problems. Aspects of systems engineering that provide an understanding of management of large scale systems are broadly covered here. Due to the focus and application of research, other significant factors (e.g., human behavior, decision making, etc.) are not emphasized but are considered.

  8. DNA Nanostructure-based Interfacial engineering for PCR-free ultrasensitive electrochemical analysis of microRNA

    NASA Astrophysics Data System (ADS)

    Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai

    2012-11-01

    MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.

  9. DNA Nanostructure-based Interfacial engineering for PCR-free ultrasensitive electrochemical analysis of microRNA

    PubMed Central

    Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai

    2012-01-01

    MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients. PMID:23162691

  10. Engineering monitoring expert system's developer

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1991-01-01

    This research project is designed to apply artificial intelligence technology including expert systems, dynamic interface of neural networks, and hypertext to construct an expert system developer. The developer environment is specifically suited to building expert systems which monitor the performance of ground support equipment for propulsion systems and testing facilities. The expert system developer, through the use of a graphics interface and a rule network, will be transparent to the user during rule constructing and data scanning of the knowledge base. The project will result in a software system that allows its user to build specific monitoring type expert systems which monitor various equipments used for propulsion systems or ground testing facilities and accrues system performance information in a dynamic knowledge base.

  11. Big system: Interactive graphics for the engineer

    NASA Technical Reports Server (NTRS)

    Quenneville, C. E.

    1975-01-01

    The BCS Interactive Graphics System (BIG System) approach to graphics was presented, along with several significant engineering applications. The BIG System precompiler, the graphics support library, and the function requirements of graphics applications are discussed. It was concluded that graphics standardization and a device independent code can be developed to assure maximum graphic terminal transferability.

  12. Turbopump systems for liquid rocket engines

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The turbopump system, from preliminary design through rocket engine testing is examined. Selection of proper system type for each application and integration of the components into a working system are dealt with. Details are also given on the design of various components including inducers, pumps, turbines, gears, and bearings.

  13. New engineering systems for mobility

    NASA Technical Reports Server (NTRS)

    Keller, T. L.; Kelvin, A.

    1974-01-01

    Aerospace technology transfer and a systems integration approach are considered in the development of a transportation system for the handicapped. The basic vehicle design includes a slide-out boarding ramp and wheelchair accommodations.

  14. Deep Space Telecommunications Systems Engineering

    NASA Technical Reports Server (NTRS)

    Yuen, J. H. (Editor)

    1982-01-01

    Descriptive and analytical information useful for the optimal design, specification, and performance evaluation of deep space telecommunications systems is presented. Telemetry, tracking, and command systems, receiver design, spacecraft antennas, frequency selection, interference, and modulation techniques are addressed.

  15. Model for Calculating Electrolytic Shunt Path Losses in Large Electrochemical Energy Conversion Systems

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.

    1976-01-01

    Generalized analysis and solution techniques were developed to evaluate the shunt power losses in electrochemical systems designed with a common or circulating electrolyte supply. Sample data are presented for a hypothetical bulk energy storage redox system, and the general applicability of the analysis technique is discussed.

  16. Tank waste remediation system systems engineering management plan

    SciTech Connect

    Peck, L.G.

    1998-01-08

    This Systems Engineering Management Plan (SEMP) describes the Tank Waste Remediation System (TWRS) implementation of the US Department of Energy (DOE) systems engineering policy provided in 97-IMSD-193. The SEMP defines the products, process, organization, and procedures used by the TWRS Project to implement the policy. The SEMP will be used as the basis for tailoring the systems engineering applications to the development of the physical systems and processes necessary to achieve the desired end states of the program. It is a living document that will be revised as necessary to reflect changes in systems engineering guidance as the program evolves. The US Department of Energy-Headquarters has issued program management guidance, DOE Order 430. 1, Life Cycle Asset Management, and associated Good Practice Guides that include substantial systems engineering guidance.

  17. Thermoelectric system for an engine

    DOEpatents

    Mcgilvray, Andrew N.; Vachon, John T.; Moser, William E.

    2010-06-22

    An internal combustion engine that includes a block, a cylinder head having an intake valve port and exhaust valve port formed therein, a piston, and a combustion chamber defined by the block, the piston, and the head. At least one thermoelectric device is positioned within either or both the intake valve port and the exhaust valve port. Each of the valves is configured to move within a respective intake and exhaust valve port thereby causing said valves to engage the thermoelectric devices resulting in heat transfer from the valves to the thermoelectric devices. The intake valve port and exhaust valve port are configured to fluidly direct intake air and exhaust gas, respectively, into the combustion chamber and the thermoelectric device is positioned within the intake valve port, and exhaust valve port, such that the thermoelectric device is in contact with the intake air and exhaust gas.

  18. Olivine electrode engineering impact on the electrochemical performance of lithium-ion batteries.

    SciTech Connect

    Lu, W.; Jansen, A.; Dees, D.; Henriksen, G.; Chemical Sciences and Engineering Division

    2010-08-01

    High energy and power density lithium iron phosphate was studied for hybrid electric vehicle applications. This work addresses the effects of porosity in a composite electrode using a four-point probe resistivity analyzer, galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The four-point probe result indicates that the porosity of composite electrode affects the electronic conductivity significantly. This effect is also observed from the cell's pulse current discharge performance. Compared to the direct current (dc) methods used, the EIS data are more sensitive to electrode porosity, especially for electrodes with low porosity values.

  19. Results of Investigative Tests of Gas Turbine Engine Compressor Blades Obtained by Electrochemical Machining

    NASA Astrophysics Data System (ADS)

    Kozhina, T. D.; Kurochkin, A. V.

    2016-04-01

    The paper highlights results of the investigative tests of GTE compressor Ti-alloy blades obtained by the method of electrochemical machining with oscillating tool-electrodes, carried out in order to define the optimal parameters of the ECM process providing attainment of specified blade quality parameters given in the design documentation, while providing maximal performance. The new technological methods suggested based on the results of the tests; in particular application of vibrating tool-electrodes and employment of locating elements made of high-strength materials, significantly extend the capabilities of this method.

  20. Reusable rocket engine turbopump health management system

    NASA Astrophysics Data System (ADS)

    Surko, Pamela

    1994-10-01

    A health monitoring expert system software architecture has been developed to support condition-based health monitoring of rocket engines. Its first application is in the diagnosis decisions relating to the health of the high pressure oxidizer turbopump (HPOTP) of Space Shuttle Main Engine (SSME). The post test diagnostic system runs off-line, using as input the data recorded from hundreds of sensors, each running typically at rates of 25, 50, or .1 Hz. The system is invoked after a test has been completed, and produces an analysis and an organized graphical presentation of the data with important effects highlighted. The overall expert system architecture has been developed and documented so that expert modules analyzing other line replaceable units may easily be added. The architecture emphasizes modularity, reusability, and open system interfaces so that it may be used to analyze other engines as well.

  1. Reusable Rocket Engine Turbopump Health Management System

    NASA Technical Reports Server (NTRS)

    Surko, Pamela

    1994-01-01

    A health monitoring expert system software architecture has been developed to support condition-based health monitoring of rocket engines. Its first application is in the diagnosis decisions relating to the health of the high pressure oxidizer turbopump (HPOTP) of Space Shuttle Main Engine (SSME). The post test diagnostic system runs off-line, using as input the data recorded from hundreds of sensors, each running typically at rates of 25, 50, or .1 Hz. The system is invoked after a test has been completed, and produces an analysis and an organized graphical presentation of the data with important effects highlighted. The overall expert system architecture has been developed and documented so that expert modules analyzing other line replaceable units may easily be added. The architecture emphasizes modularity, reusability, and open system interfaces so that it may be used to analyze other engines as well.

  2. Generative engineering databases - Toward expert systems

    NASA Technical Reports Server (NTRS)

    Rasdorf, W. J.; Salley, G. C.

    1985-01-01

    Engineering data management, incorporating concepts of optimization with data representation, is receiving increasing attention as the amount and complexity of information necessary for performing engineering operations increases and the need to coordinate its representation and use increases. Research in this area promises advantages for a wide variety of engineering applications, particularly those which seek to use data in innovative ways in the engineering process. This paper presents a framework for a comprehensive, relational database management system that combines a knowledge base of design constraints with a database of engineering data items in order to achieve a 'generative database' - one which automatically generates new engineering design data according to the design constraints stored in the knowledge base. The representation requires a database that is able to store all of the data normally associated with engineering design and to accurately represent the interactions between constraints and the stored data while guaranteeing its integrity. The representation also requires a knowledge base that is able to store all the constraints imposed upon the engineering design process.

  3. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  4. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  5. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  6. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  7. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  8. Electrochemical investigation of interaction between mitomycin C and DNA in a novel drug-delivery system.

    PubMed

    Karadeniz, Hakan; Alparslan, Levent; Erdem, Arzum; Karasulu, Ercument

    2007-10-18

    A novel drug-delivery system was developed by loading the anticancer drug, mitomycin C (MC) into an oil/water system with the aim of investigation by electrochemical sensing the interaction between the drug and DNA in microemulsion phase. The physical and physicochemical properties (droplet size, pH, viscosity, conductivity and refractive index) of this microemulsion were examined. The electrochemical detection of the interaction between MC and double-stranded DNA (dsDNA) in microemulsion phase was performed by using differential pulse voltammetry (DPV) in combination with a disposable sensor, pencil graphite electrode (PGE). The magnitude of guanine oxidation signal was monitored before and after interaction between MC and dsDNA. The effect of different experimental parameters, such as MC concentration, MC interaction time with dsDNA, and dsDNA concentration were also studied to find the optimum analytical performance based on electrochemical detection of this interaction in microemulsion phase. PMID:17590560

  9. Predicted emissions from a methanol-fueled ``electrochemical automobile engine`` based on a PEM fuel cell

    SciTech Connect

    Amphlett, J.C.; Mann, R.F.; Peppley, B.A.

    1995-12-31

    A simulation of a fuel cell engine (FCE) based on a proton exchange membrane (PEM) fuel-cell stack was developed using a process simulation software package. Rates of emissions of unburned methanol, formaldehyde, CO and NO{sub x}, were calculated based on chemical equilibria. The predicted rates of emissions for unburned methanol, formaldehyde and CO were found to all be less than 1 {micro}g/km. This is considerably less than has been reported in the literature but represents a theoretical limit which should be achievable as effective catalytic-combustion systems are developed for hydrogen/methanol fueled burners. The worst-case rate of NO{sub x}, emissions was shown to be less than 0.03 g/km (0.05 g/mi.). It was found that increasing the rate of heat transfer in the steam reformer, which converts the methanol to a hydrogen-rich gas, significantly reduced the rate of NO{sub x}, emission due to the lower burner temperatures which could be used. The results indicate that, in terms of emissions reduction, a methanol fueled FCE is an excellent long-term alternative to the ICE.

  10. Paraquat-Melanin Redox-Cycling: Evidence from Electrochemical Reverse Engineering.

    PubMed

    Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; Panzella, Lucia; Alfieri, Maria Laura; Napolitano, Alessandra; Bentley, William E; Payne, Gregory F

    2016-08-17

    Parkinson's disease is a neurodegenerative disorder associated with oxidative stress and the death of melanin-containing neurons of the substantia nigra. Epidemiological evidence links exposure to the pesticide paraquat (PQ) to Parkinson's disease, and this link has been explained by a redox cycling mechanism that induces oxidative stress. Here, we used a novel electrochemistry-based reverse engineering methodology to test the hypothesis that PQ can undergo reductive redox cycling with melanin. In this method, (i) an insoluble natural melanin (from Sepia melanin) and a synthetic model melanin (having a cysteinyldopamine-melanin core and dopamine-melanin shell) were entrapped in a nonconducting hydrogel film adjacent to an electrode, (ii) the film-coated electrode was immersed in solutions containing PQ (putative redox cycling reductant) and a redox cycling oxidant (ferrocene dimethanol), (iii) sequences of input potentials (i.e., voltages) were imposed to the underlying electrode to systematically engage reductive and oxidative redox cycling, and (iv) output response currents were analyzed for signatures of redox cycling. The response characteristics of the PQ-melanin systems to various input potential sequences support the hypothesis that PQ can directly donate electrons to melanin. This observation of PQ-melanin redox interactions demonstrates an association between two components that have been individually linked to oxidative stress and Parkinson's disease. Potentially, melanin's redox activity could be an important component in understanding the etiology of neurological disorders such as Parkinson's disease. PMID:27246915